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1

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

Microsoft Academic Search

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

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

2010-01-01

2

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

3

Structure and evolution of the Magnitogorsk forearc basin: Identifying upper crustal processes during arc-continent collision in the southern Urals  

Microsoft Academic Search

The southern Urals of Russia contain a well-preserved example of a Paleozoic arc-continent collision in which the intraoceanic Magnitogorsk volcanic arc and its forearc basin sediments accreted to the East European Craton during the Devonian. The Magnitogorsk arc records the evolution from incipient intraoceanic subduction to a mature arc, and by comparing its surface geological features with those in active

D. Brown; J. Alvarez-Marrón; A. Pérez-Estaún; V. Puchkov; Y. Gorozhanina; P. Ayarza

2001-01-01

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

Structure and evolution of the Magnitogorsk forearc basin: Identifying upper crustal processes during arc-continent collision in the southern Urals  

NASA Astrophysics Data System (ADS)

The southern Urals of Russia contain a well-preserved example of a Paleozoic arc-continent collision in which the intraoceanic Magnitogorsk volcanic arc and its forearc basin sediments accreted to the East European Craton during the Devonian. The Magnitogorsk arc records the evolution from incipient intraoceanic subduction to a mature arc, and by comparing its surface geological features with those in active arc-continent collision settings it is possible to identify upper crustal processes that were active in the southern Urals. The arc edifice can be divided into western and eastern volcanic fronts that were active during different stages of arc evolution and for which two distinct phases of forearc basin development can be recognized. The late Lower to Middle Devonian Aktau Formation represents a remnant of the intraoceanic to collisional forearc basin to the Irendyk volcanic front, whereas the Middle Devonian to Lower Carboniferous Ulutau, Koltubanian, and Zilair Formations were deposited in a suture forearc basin to the east Magnitogorsk volcanic front. It was not until the Late Devonian that these two basins were joined. Structural mapping, combined with reflection seismic profiling, shows these basins to be affected by open, nonlinear, volcanic basement-cored synsedimentary folds. The Karamalytash anticline appears to have the geometry of a growth fold that formed during deposition of sediments in the suture forearc basin. The forearc region is affected by minor thrusting that involves the volcanic basement, although it is not clear if these thrusts reactivate preexisting trench-parallel faults. Synsedimentary deformation, slumping, and olistostrome development were common throughout the suture forearc basin history but were especially widespread during the Late Devonian, when the full thickness of the continental crust is interpreted as having arrived at the subduction zone.

Brown, D.; Alvarez-Marrón, J.; PéRez-Estaún, A.; Puchkov, V.; Gorozhanina, Y.; Ayarza, P.

2001-06-01

6

A novel streptococcal integrative conjugative element involved in iron acquisition.  

PubMed

In this study, we determined the function of a novel non-ribosomal peptide synthetase (NRPS) system carried by a streptococcal integrative conjugative element (ICE), ICESe2. The NRPS shares similarity with the yersiniabactin system found in the high-pathogenicity island of Yersinia sp. and is the first of its kind to be identified in streptococci. We named the NRPS product 'equibactin' and genes of this locus eqbA-N. ICESe2, although absolutely conserved in Streptococcus equi, the causative agent of equine strangles, was absent from all strains of the closely related opportunistic pathogen Streptococcus zooepidemicus. Binding of EqbA, a DtxR-like regulator, to the eqbB promoter was increased in the presence of cations. Deletion of eqbA resulted in a small-colony phenotype. Further deletion of the irp2 homologue eqbE, or the genes eqbH, eqbI and eqbJ encoding a putative ABC transporter, or addition of the iron chelator nitrilotriacetate, reversed this phenotype, implicating iron toxicity. Quantification of (55)Fe accumulation and sensitivity to streptonigrin suggested that equibactin is secreted by S. equi and that the eqbH, eqbI and eqbJ genes are required for its associated iron import. In agreement with a structure-based model of equibactin synthesis, supplementation of chemically defined media with salicylate was required for equibactin production. PMID:18990191

Heather, Zoe; Holden, Matthew T G; Steward, Karen F; Parkhill, Julian; Song, Lijiang; Challis, Gregory L; Robinson, Carl; Davis-Poynter, Nicholas; Waller, Andrew S

2008-12-01

7

A novel streptococcal integrative conjugative element involved in iron acquisition  

PubMed Central

In this study, we determined the function of a novel non-ribosomal peptide synthetase (NRPS) system carried by a streptococcal integrative conjugative element (ICE), ICESe2. The NRPS shares similarity with the yersiniabactin system found in the high-pathogenicity island of Yersinia sp. and is the first of its kind to be identified in streptococci. We named the NRPS product ‘equibactin’ and genes of this locus eqbA–N. ICESe2, although absolutely conserved in Streptococcus equi, the causative agent of equine strangles, was absent from all strains of the closely related opportunistic pathogen Streptococcus zooepidemicus. Binding of EqbA, a DtxR-like regulator, to the eqbB promoter was increased in the presence of cations. Deletion of eqbA resulted in a small-colony phenotype. Further deletion of the irp2 homologue eqbE, or the genes eqbH, eqbI and eqbJ encoding a putative ABC transporter, or addition of the iron chelator nitrilotriacetate, reversed this phenotype, implicating iron toxicity. Quantification of 55Fe accumulation and sensitivity to streptonigrin suggested that equibactin is secreted by S. equi and that the eqbH, eqbI and eqbJ genes are required for its associated iron import. In agreement with a structure-based model of equibactin synthesis, supplementation of chemically defined media with salicylate was required for equibactin production. PMID:18990191

Heather, Zoe; Holden, Matthew T G; Steward, Karen F; Parkhill, Julian; Song, Lijiang; Challis, Gregory L; Robinson, Carl; Davis-Poynter, Nicholas; Waller, Andrew S

2008-01-01

8

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 ...

9

Mitochondrial iron trafficking and the integration of iron metabolism between the mitochondrion and cytosol  

PubMed Central

The mitochondrion is well known for its key role in energy transduction. However, it is less well appreciated that it is also a focal point of iron metabolism. Iron is needed not only for heme and iron sulfur cluster (ISC)-containing proteins involved in electron transport and oxidative phosphorylation, but also for a wide variety of cytoplasmic and nuclear functions, including DNA synthesis. The mitochondrial pathways involved in the generation of both heme and ISCs have been characterized to some extent. However, little is known concerning the regulation of iron uptake by the mitochondrion and how this is coordinated with iron metabolism in the cytosol and other organelles (e.g., lysosomes). In this article, we discuss the burgeoning field of mitochondrial iron metabolism and trafficking that has recently been stimulated by the discovery of proteins involved in mitochondrial iron storage (mitochondrial ferritin) and transport (mitoferrin-1 and -2). In addition, recent work examining mitochondrial diseases (e.g., Friedreich's ataxia) has established that communication exists between iron metabolism in the mitochondrion and the cytosol. This finding has revealed the ability of the mitochondrion to modulate whole-cell iron-processing to satisfy its own requirements for the crucial processes of heme and ISC synthesis. Knowledge of mitochondrial iron-processing pathways and the interaction between organelles and the cytosol could revolutionize the investigation of iron metabolism. PMID:20495089

Richardson, Des R.; Lane, Darius J. R.; Becker, Erika M.; Huang, Michael L.-H.; Whitnall, Megan; Rahmanto, Yohan Suryo; Sheftel, Alex D.; Ponka, Prem

2010-01-01

10

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...

11

Integrated process for thermal cracking of heavy oil and reduction of iron ores  

SciTech Connect

Vacuum distillation residue oil having a conradson carbon value of 5 to 40% and a specific gravity of 0.9 to 1.10 is thermally cracked in the presence of iron ore particles in fluidized state in a thermal cracking reactor thereby to produce light oils and cracked gases and to form by-product carbon, which is caused to deposit on the iron ore particles, which are then transferred to and heated at 800 to 1200/sup 0/ C in a reducing furnace to be reduced in a solid state reaction, into sponge iron. Thus, heavy oil is thermally cracked and sponge iron is produced by an economical, integrated process.

Koizumi, K.; Miura, E.; Mori, K.; Nishida, R.

1982-06-15

12

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

E-print Network

FRACTURE TOUGHNESS STUDIES OF GRAY AND DUCTILE CAST IRONS USING A J-INTEGRAL APPROACH A Thesis by DONNA LYNNE WOODALL FLOYD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1981 Major Subject: Mechanical Engineering FRACTURE TOUGHNESS STUDIES OF GRAY AND DUCTILE CAST IRONS USING A J-INTEGRAL APPROACH A Thesis by DONNA LYNNE WOODALL FLOYD Approved as to style and content by: (Member) (Chairman...

Floyd, Donna Lynne Woodall

1981-01-01

13

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...

14

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...

15

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

PubMed

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 the 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

2012-07-13

16

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

17

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

18

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

19

Volatile organic compound constituents from an integrated iron and steel facility.  

PubMed

This study measured the volatile organic compound (VOC) constituents of four processes in an integrated iron and steel industry; cokemaking, sintering, hot forming, and cold forming. Toluene, 1,2,4-trimethylbenzene, isopentane, m,p-xylene, 1-butene, ethylbenzene, and benzene were the predominant VOC species in these processes. However, some of the chlorinated compounds were high (hundreds ppbv), i.e., trichloroethylene in all four processes, carbon tetrachloride in the hot forming process, chlorobenzene in the cold forming process, and bromomethane in the sintering process. In the sintering process, the emission factors of toluene, benzene, xylene, isopentane, 1,2,4-trimethylbenzene, and ethylbenzene were over 9 g/tonne-product. In the vicinity of the manufacturing plant, toluene, isopentane, 1,2,4-trimethylbenzene, xylene and ethylbenzene were high. Toluene, 1,2,4-trimethylbenzene, xylene, 1-butene and isopentane were the major ozone formation species. Aromatic compounds were the predominant VOC groups, constituting 45-70% of the VOC concentration and contributing >70% to the high ozone formation potential in the stack exhaust and workplace air. The sequence of VOC concentration and ozone formation potential was as follows: cold forming>sintering>hot forming>cokemaking. For the workplace air, cokemaking was the highest producer, which was attributed to the fugitive emissions of the coke oven and working process release. PMID:18289777

Tsai, Jiun-Horng; Lin, Kuo-Hsiung; Chen, Chih-Yu; Lai, Nina; Ma, Sen-Yi; Chiang, Hung-Lung

2008-09-15

20

Integrating Microarray Analysis and the Soybean Genome to Understand the Soybean's Iron Deficiency Response  

Technology Transfer Automated Retrieval System (TEKTRAN)

Transcriptional profiles of soybean (Glycine max, L. Merr) near isogenic lines Clark (PI548553, iron efficient) and IsoClark (PI547430, iron inefficient) were analyzed and compared using the Affymetrix® GeneChip® Soybean Genome Array. A comparison of plants grown under Fe-sufficient and Fe-limited ...

21

Fracture toughness studies of nodular iron using a J-integral approach  

E-print Network

in silicon content and nodule count except at low temperatures. An unsuccessful attempt was made to correlate the Kl lc values of nodular iron to the results of notched tensile tests. ACKNOWLEDGEMENT S The financial support of this work by the Iron... Electron Microscope Fractography RESULTS AND DISCUSSION Fracture Toughness Fractography Silicon Content Pearlite Content Xl. 16 18 20 21 21 21 30 33 35 35 42 71 Nodule Count Notched Tensile Tests Comparative Results CONCLUSIONS RE FE...

Mead, Hearl Edward

1979-01-01

22

The Iron Transport Protein NRAMP2 Is an Integral Membrane Glycoprotein That Colocalizes with Transferrin in Recycling Endosomes  

PubMed Central

The natural resistance associated macrophage protein (Nramp) gene family is composed of two members in mammals, Nramp1 and Nramp2. Nramp1 is expressed primarily in macrophages and mutations at this locus cause susceptibility to infectious diseases. Nramp2 has a much broader range of tissue expression and mutations at Nramp2 result in iron deficiency, indicating a role for Nramp2 in iron metabolism. To get further insight into the function and mechanism of action of Nramp proteins, we have generated isoform specific anti-Nramp1 and anti-Nramp2 antisera. Immunoblotting experiments indicate that Nramp2 is present in a number of cell types, including hemopoietic precursors, and is coexpressed with Nramp1 in primary macrophages and macrophage cell lines. Nramp2 is expressed as a 90–100-kD integral membrane protein extensively modified by glycosylation (>40% of molecular mass). Subcellular localization studies by immunofluorescence and confocal microscopy indicate distinct and nonoverlapping localization for Nramp1 and Nramp2. Nramp1 is expressed in the lysosomal compartment, whereas Nramp2 is not detectable in the lysosomes but is expressed primarily in recycling endosomes and also, to a lower extent, at the plasma membrane, colocalizing with transferrin. These findings suggest that Nramp2 plays a key role in the metabolism of transferrin-bound iron by transporting free Fe2+ across the endosomal membrane and into the cytoplasm. PMID:10049947

Gruenheid, Samantha; Canonne-Hergaux, François; Gauthier, Susan; Hackam, David J.; Grinstein, Sergio; Gros, Philippe

1999-01-01

23

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

24

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

NASA Astrophysics Data System (ADS)

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° C for 90 min and then austempered in fluidized bed at 380° 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.

2011-01-01

25

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...

26

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...

27

Lithium iron phosphate battery electrode integrity following high speed pulsed laser cutting  

NASA Astrophysics Data System (ADS)

Laser exposures are performed on lithium iron phosphate battery electrodes at 1 hbox {m}/hbox {s} with process parameters based on those leading to the smallest heat affected zone for low power laser exposure at 100 hbox {mm}/hbox {s} . Scanning electron microscopy and Raman analysis are performed along the resulting cut edges to characterize macroscopic, chemical and microstructural changes resulting from laser exposure. The increase in velocity with respect to previous studies is found to limit macroscopic changes to areas directly exposed to the laser beam and greatly suppress or completely eliminate microstructural and chemical changes resulting from thermal conduction effects in the metallic conductor layers. These results confirm laser technology as a viable, more flexible solution to mechanical blanking devices for the cutting of lithium iron phosphate battery electrode films.

Lutey, Adrian H. A.; Fiorini, Maurizio; Fortunato, Alessandro; Carmignato, Simone

2015-03-01

28

Integral testing of the evaluated data files for silicon, zirconium, niobium and iron  

SciTech Connect

The evaluated data testing for Si, Zr, Nb and Fe materials has been performed through the analyses of the neutron leakage spectrum from spherical assemblies measured in integral benchmark experiments with (d,t) and Cf fission neutron sources. Intercomparisons of the calculated from BROND-2, ENDF/B-6 and JENDL-3 data files with experimental results are presented.

Blokhin, A.I.; Ignatyuk, A.V.; Sinitsa, V.V. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1994-12-31

29

Health risk assessment of exposure to selected volatile organic compounds emitted from an integrated iron and steel plant.  

PubMed

Workplace air samples from sintering, cokemaking, and hot and cold forming processes in the integrated iron and steel industry were analyzed to determine their volatile organic compound (VOC) concentration. Sixteen VOC species including three paraffins (cyclohexane, n-hexane, methylcyclohexane), five chlorinated VOC species (trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, chlorobenzene, 1,4-dichlorobenzene), and eight aromatics (benzene, ethylbenzene, styrene, toluene, m,p-xylene, o-xylene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene) were selected to measure their noncancer risk for workers. Concentrations of toluene, xylene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, dichlorobenzene, and trichloroethylene were high in all four processes. Carbon tetrachloride and tetrachloroethylene concentrations were high in the hot and cold forming processes. The noncancer risk followed the increasing order: cokemaking > sintering > hot forming > cold forming. 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene contributed 44% to 65% and 13% to 20% of noncancer risk, respectively, for the four processes. Benzene accounted for a high portion of the noncancer risk in cokemaking. The hazard index (HI: 17-108) of the average VOC concentrations suggests that health risks can be reduced by improving workplace air quality and protecting workers. PMID:20828338

Chang, E-E; Wei-Chi, Wang; Li-Xuan, Zeng; Hung-Lung, Chiang

2010-12-01

30

Iron deficiency anemia.  

PubMed

Iron is essential to virtually all living organisms and is integral to multiple metabolic functions. The most important function is oxygen transport in hemoglobin. Iron deficiency anemia in dogs and cats is usually caused by chronic blood loss and can be discovered incidentally as animals may have adapted to the anemia. Severe iron deficiency is characterized by a microcytic, hypochromic, potentially severe anemia with a variable regenerative response. Iron metabolism and homeostasis will be reviewed, followed by a discussion of diagnostic testing and therapeutic recommendations for dogs and cats with iron deficiency anemia. PMID:22942439

Naigamwalla, Dinaz Z; Webb, Jinelle A; Giger, Urs

2012-03-01

31

Iron-Air Rechargeable Battery  

NASA Technical Reports Server (NTRS)

Embodiments include an iron-air rechargeable battery having a composite electrode including an iron electrode and a hydrogen electrode integrated therewith. An air electrode is spaced from the iron electrode and an electrolyte is provided in contact with the air electrode and the iron electrodes. Various additives and catalysts are disclosed with respect to the iron electrode, air electrode, and electrolyte for increasing battery efficiency and cycle life.

Narayan, Sri R. (Inventor); Prakash, G.K. Surya (Inventor); Kindler, Andrew (Inventor)

2014-01-01

32

Iron and Iron Deficiency  

MedlinePLUS

... from these substances is usually not of concern. Vegetarian diets are low in heme iron, but careful meal ... heme iron sources in the diet (e.g., vegetarian diets) Low absorption Taking antacids beyond the recommended dose ...

33

Iron contamination in silicon technology  

Microsoft Academic Search

.   This article continues the review of fundamental physical properties of iron and its complexes in silicon (Appl. Phys. A 69, 13 (1999)), and is focused on ongoing applied research of iron in silicon technology. The first section of this article\\u000a presents an analysis of the effect of iron on devices, including integrated circuits, power devices, and solar cells. Then,

A. A. Istratov; H. Hieslmair; E. R. Weber

2000-01-01

34

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

35

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

36

The DUF59 family gene AE7 acts in the cytosolic iron-sulfur cluster assembly pathway to maintain nuclear genome integrity in Arabidopsis.  

PubMed

Eukaryotic organisms have evolved a set of strategies to safeguard genome integrity, but the underlying mechanisms remain poorly understood. Here, we report that asymmetric leaves1/2 enhancer7 (AE7), an Arabidopsis thaliana gene encoding a protein in the evolutionarily conserved Domain of Unknown Function 59 family, participates in the cytosolic iron-sulfur (Fe-S) cluster assembly (CIA) pathway to maintain genome integrity. The severe ae7-2 allele is embryo lethal, whereas plants with the weak ae7 (ae7-1) allele are viable but exhibit highly accumulated DNA damage that activates the DNA damage response to arrest the cell cycle. AE7 is part of a protein complex with CIA1, NAR1, and MET18, which are highly conserved in eukaryotes and are involved in the biogenesis of cytosolic and nuclear Fe-S proteins. ae7-1 plants have lower activities of the cytosolic [4Fe-4S] enzyme aconitase and the nuclear [4Fe-4S] enzyme DNA glycosylase ROS1. Additionally, mutations in the gene encoding the mitochondrial ATP binding cassette transporter ATM3/ABCB25, which is required for the activity of cytosolic Fe-S enzymes in Arabidopsis, also result in defective genome integrity similar to that of ae7-1. These results indicate that AE7 is a central member of the CIA pathway, linking plant mitochondria to nuclear genome integrity through assembly of Fe-S proteins. PMID:23104832

Luo, Dexian; Bernard, Delphine G; Balk, Janneke; Hai, Huang; Cui, Xiaofeng

2012-10-01

37

The DUF59 Family Gene AE7 Acts in the Cytosolic Iron-Sulfur Cluster Assembly Pathway to Maintain Nuclear Genome Integrity in Arabidopsis[C][W][OA  

PubMed Central

Eukaryotic organisms have evolved a set of strategies to safeguard genome integrity, but the underlying mechanisms remain poorly understood. Here, we report that ASYMMETRIC LEAVES1/2 ENHANCER7 (AE7), an Arabidopsis thaliana gene encoding a protein in the evolutionarily conserved Domain of Unknown Function 59 family, participates in the cytosolic iron-sulfur (Fe-S) cluster assembly (CIA) pathway to maintain genome integrity. The severe ae7-2 allele is embryo lethal, whereas plants with the weak ae7 (ae7-1) allele are viable but exhibit highly accumulated DNA damage that activates the DNA damage response to arrest the cell cycle. AE7 is part of a protein complex with CIA1, NAR1, and MET18, which are highly conserved in eukaryotes and are involved in the biogenesis of cytosolic and nuclear Fe-S proteins. ae7-1 plants have lower activities of the cytosolic [4Fe-4S] enzyme aconitase and the nuclear [4Fe-4S] enzyme DNA glycosylase ROS1. Additionally, mutations in the gene encoding the mitochondrial ATP binding cassette transporter ATM3/ABCB25, which is required for the activity of cytosolic Fe-S enzymes in Arabidopsis, also result in defective genome integrity similar to that of ae7-1. These results indicate that AE7 is a central member of the CIA pathway, linking plant mitochondria to nuclear genome integrity through assembly of Fe-S proteins. PMID:23104832

Luo, Dexian; Bernard, Delphine G.; Balk, Janneke; Hai, Huang; Cui, Xiaofeng

2012-01-01

38

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

NASA Astrophysics Data System (ADS)

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; Eto, Yu; Kobayashi, Keiichi; Haga, Yoji; Inoue, Mitsuteru; Ross, C. A.

2013-05-01

39

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

40

Development of Bottom-up Representation of Industrial Energy Efficiency Technologies in Integrated Assessment Models for the Iron and Steel Sector  

SciTech Connect

Adoption of efficient end-use technologies is one of the key measures for reducing greenhouse gas (GHG) emissions. With the working of energy programs and policies on carbon regulation, how to effectively analyze and manage the costs associated with GHG reductions become extremely important for the industry and policy makers around the world. Energy-climate (EC) models are often used for analyzing the costs of reducing GHG emissions (e.g., carbon emission) for various emission-reduction measures, because an accurate estimation of these costs is critical for identifying and choosing optimal emission reduction measures, and for developing related policy options to accelerate market adoption and technology implementation. However, accuracies of assessing of GHG-emission reduction costs by taking into account the adoption of energy efficiency technologies will depend on how well these end-use technologies are represented in integrated assessment models (IAM) and other energy-climate models. In this report, we first conduct brief overview on different representations of end-use technologies (mitigation measures) in various energy-climate models, followed by problem statements, and a description of the basic concepts of quantifying the cost of conserved energy including integrating non-regrets options. A non-regrets option is defined as a GHG reduction option that is cost effective, without considering their additional benefits related to reducing GHG emissions. Based upon these, we develop information on costs of mitigation measures and technological change. These serve as the basis for collating the data on energy savings and costs for their future use in integrated assessment models. In addition to descriptions of the iron and steel making processes, and the mitigation measures identified in this study, the report includes tabulated databases on costs of measure implementation, energy savings, carbon-emission reduction, and lifetimes. The cost curve data on mitigation measures are available over time, which allows an estimation of technological change over a decade-long historical period. In particular, the report will describe new treatment of technological change in energy-climate modeling for this industry sector, i.e., assessing the changes in costs and energy-savings potentials via comparing 1994 and 2002 conservation supply curves. In this study, we compared the same set of mitigation measures for both 1994 and 2002 -- no additional mitigation measure for year 2002 was included due to unavailability of such data. Therefore, the estimated potentials in total energy savings and carbon reduction would most likely be more conservative for year 2002 in this study. Based upon the cost curves, the rate of change in the savings potential at a given cost can be evaluated and be used to estimate future rates of change that can be the input for energy-climate models. Through characterizing energy-efficiency technology costs and improvement potentials, we have developed and presented energy cost curves for energy efficiency measures applicable to the U.S. iron and steel industry for the years 1994 and 2002. The cost curves can change significantly under various scenarios: the baseline year, discount rate, energy intensity, production, industry structure (e.g., integrated versus secondary steel making and number of plants), efficiency (or mitigation) measures, share of iron and steel production to which the individual measures can be applied, and inclusion of other non-energy benefits. Inclusion of other non-energy benefits from implementing mitigation measures can reduce the costs of conserved energy significantly. In addition, costs of conserved energy (CCE) for individual mitigation measures increase with the increases in discount rates, resulting in a general increase in total cost of mitigation measures for implementation and operation with a higher discount rate. In 1994, integrated steel mills in the U.S. produced 55.

Xu, T.T.; Sathaye, J.; Galitsky, C.

2010-09-30

41

Iron overdose  

MedlinePLUS

Iron is an ingredient in many mineral and vitamin supplements. Iron supplements are also sold by themselves. Types include: Ferrous sulfate (Feosol, Slow Fe) Ferrous gluconate (Fergon) Ferrous fumarate (Femiron, Feostat) Note: This list may not be all-inclusive.

42

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,

43

Complete debromination of decabromodiphenyl ether using the integration of Dehalococcoides sp. strain CBDB1 and zero-valent iron.  

PubMed

This study investigated the effects of nano- and micro-scale zero-valent iron (nZVI and mZVI) particles on Dehalococcoides sp. strain CBDB1 participating in anaerobic reduction of polybrominated diphenyl ethers. nZVI (>0.25 g L(-)(1)) had an inhibitory effect upon this strain, whereas 1.0 g L(-1) mZVI showed no negative impact on bacterial growth. Strain CBDB1 could only utilize lower brominated congeners (<7 bromines) as electron acceptor. In the bio-ZVI system, decabromodiphenyl ether (BDE-209) was first reduced by ZVI to lower brominated congeners, which were then dehalogenated to diphenyl ether by CBDB1. Within 30 d, a BDE-209 debromination efficiency of 16% and 24% was obtained in the bio-nZVI (0.25 g L(-1)) and bio-mZVI (1.0 g L(-1)) systems with a corresponding diphenyl ether yield efficiency of 14% and 19%, respectively. The debromination efficiency increased significantly from 8% to 24% with an increase of mZVI dosage from 0.25 to 1.0 g L(-1) in the bio-mZVI system. PMID:25217713

Xu, Guiying; Wang, Jiangbo; Lu, Mang

2014-12-01

44

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

45

Iron refractory iron deficiency anemia  

PubMed Central

Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in adulthood. The disease is refractory to oral iron treatment but shows a slow response to intravenous iron injections and partial correction of the anemia. To date, 40 different Matriptase-2 mutations have been reported, affecting all the functional domains of the large ectodomain of the protein. In vitro experiments on transfected cells suggest that Matriptase-2 cleaves Hemojuvelin, a major regulator of hepcidin expression and that this function is altered in this genetic form of anemia. In contrast to the low/undetectable hepcidin levels observed in acquired iron deficiency, in patients with Matriptase-2 deficiency, serum hepcidin is inappropriately high for the low iron status and accounts for the absent/delayed response to oral iron treatment. A challenge for the clinicians and pediatricians is the recognition of the disorder among iron deficiency and other microcytic anemias commonly found in pediatric patients. The current treatment of iron refractory iron deficiency anemia is based on parenteral iron administration; in the future, manipulation of the hepcidin pathway with the aim of suppressing it might become an alternative therapeutic approach. PMID:23729726

De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U.; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole

2013-01-01

46

Microbial Iron Cycling in Acidic Geothermal Springs of Yellowstone National Park: Integrating Molecular Surveys, Geochemical Processes, and Isolation of Novel Fe-Active Microorganisms  

PubMed Central

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

47

Iron Test  

MedlinePLUS

... and Kowdley, K. (2012). Review Article: The Iron Overload Syndromes. Medscape Reference from Aliment Pharmacol Ther . V35 (8):876-893. [On-line information]. Available online at http://www.medscape.com/viewarticle/ ...

48

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

49

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

50

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

51

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

52

Infection structure-specific reductive iron assimilation is required for cell wall integrity and full virulence of the maize pathogen Colletotrichum graminicola.  

PubMed

Ferroxidases are essential components of the high-affinity reductive iron assimilation pathway in fungi. Two ferroxidase genes, FET3-1 and FET3-2, have been identified in the genome of the maize anthracnose fungus Colletotrichum graminicola. Complementation of growth defects of the ferroxidase-deficient Saccharomyces cerevisiae strain ?fet3fet4 showed that both Fet3-1 and Fet3-2 of C. graminicola represent functional ferroxidases. Expression of enhanced green fluorescent protein fusions in yeast and C. graminicola indicated that both ferroxidase proteins localize to the plasma membrane. Transcript abundance of FET3-1 increased dramatically under iron-limiting conditions but those of FET3-2 were hardly detectable. ?fet3-1 and ?fet3-2 single as well as ?fet3-1/2 double-deletion strains were generated. Under iron-sufficient or deficient conditions, vegetative growth rates of these strains did not significantly differ from that of the wild type but ?fet3-1 and ?fet3-1/2 strains showed increased sensitivity to reactive oxygen species. Furthermore, under iron-limiting conditions, appressoria of ?fet3-1 and ?fet3-1/2 strains showed significantly reduced transcript abundance of a class V chitin synthase and exhibited severe cell wall defects. Infection assays on intact and wounded maize leaves, quantitative data of infection structure differentiation, and infection stage-specific expression of FET3-1 showed that reductive iron assimilation is required for appressorial penetration, biotrophic development, and full virulence. PMID:23639025

Albarouki, Emad; Deising, Holger B

2013-06-01

53

Iron and iron derived radicals  

SciTech Connect

We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

Borg, D.C.; Schaich, K.M.

1987-04-01

54

Formation and occurrence of biogenic iron-rich minerals  

Microsoft Academic Search

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

Danielle Fortin; Sean Langley

2005-01-01

55

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

56

The Integrated Field-Scale Subsurface Research Challenge Site (IFC) at Rifle, Colorado: Preliminary Results on Microbiological, Geochemical and Hydrologic Processes Controlling Iron Reduction and Uranium Mobility  

Microsoft Academic Search

The IFC at Rifle, Colorado was recently funded by the U.S. Department of Energy to address knowledge gaps in 1) geochemical and microbial controls on stimulated U(VI) bioreduction by iron-reducers, 2) U(VI) sorption under Fe-reducing conditions, 3) post-biostimulation U(VI) stability and removal, and 4) rates of natural bioreduction of U(VI). The over-arching goal of the project is to develop a

P. E. Long; J. Banfield; R. Bush; K. Campbell; D. P. Chandler; J. A. Davis; R. Dayvault; J. Druhan; H. Elifantz; A. Englert; R. L. Hettich; D. Holmes; S. Hubbard; J. Icenhower; P. R. Jaffe; L. J. Kerkhof; R. K. Kukkadapu; E. Lesher; M. Lipton; D. Lovley; S. Morris; S. Morrison; P. Mouser; D. Newcomer; L. N'guessan; A. Peacock; N. Qafoku; C. T. Resch; F. Spane; B. Spaulding; C. Steefel; N. Verberkmoes; M. Wilkins; K. H. Williams; S. B. Yabusaki

2007-01-01

57

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

58

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

59

Research on computational model of iron losses in SPWM fed induction motors  

Microsoft Academic Search

The iron losses increase when induction motors were supplied by inverter. Based on separated iron losses model, an iron losses computational model considering harmonic component concerning induction motor fed by SPWM inverter was presented through harmonic analysis method. The parameters of the inverter were integrated in the model. A test bench for measuring the iron losses of induction motors was

Yunkai Huang; Kunpeng Li; Qiansheng Hu

2005-01-01

60

Iron and Prochlorococcus/  

E-print Network

Iron availability and primary productivity in the oceans are intricately linked through photosynthesis. At the global scale we understand how iron addition induces phytoplankton blooms through meso-scale iron-addition ...

Thompson, Anne Williford

2009-01-01

61

Iron in diet  

MedlinePLUS

... leafy greens at a meal, you can improve absorption of vegetable sources of iron up to three ... Foods rich in vitamin C also increase iron absorption. Some foods reduce iron absorption. For example, commercial ...

62

Iron and Your Child  

MedlinePLUS

... the Flu Pregnancy Precautions Checkups: What to Expect Iron and Your Child KidsHealth > Parents > Growth & Development > Feeding & ... enough iron in their daily diets. How Much Iron Do Kids Need? Kids require different amounts of ...

63

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. ...

64

Iron Sucrose Injection  

MedlinePLUS

Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due to too little iron) in people with chronic kidney disease (damage to the kidneys which may worsen over ...

65

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

66

Iron Dextran Injection  

MedlinePLUS

... dextran injection; any other iron injections such as ferric carboxymaltose (Injectafer), ferumoxytol (Feraheme), iron sucrose (Venofer), or sodium ferric gluconate (Ferrlecit);any other medications; or any of ...

67

The liver: conductor of systemic iron balance.  

PubMed

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 (Fe(2+)) and the trivalent ferric (Fe(3+)) 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; Lin, Herbert Y

2014-01-01

68

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

69

Iron metabolism in transplantation.  

PubMed

Recipient's iron status is an important determinant of clinical outcome in transplantation medicine. This review addresses iron metabolism in solid organ transplantation, where the role of iron as a mediator of ischemia-reperfusion injury, as an immune-modulatory element, and as a determinant of organ and graft function is discussed. Although iron chelators reduce ischemia-reperfusion injury in cell and animal models, these benefits have not yet been implemented into clinical practice. Iron deficiency and iron overload are associated with reduced immune activation, whose molecular mechanisms are reviewed in detail. Furthermore, iron overload and hyperferritinemia are associated with poor prognosis in end-stage organ failure in patients awaiting kidney, or liver transplantation. This negative prognostic impact of iron overload appears to persist after transplantation, which highlights the need for optimizing iron management before and after solid organ transplantation. In contrast, iron deficiency and anemia are also associated with poor prognosis in patients with end-stage heart failure. Intravenous iron supplementation should be managed carefully because parenterally induced iron overload could persist after successful transplantation. In conclusion, current evidence shows that iron overload and iron deficiency are important risk factors before and after solid organ transplantation. Iron status should therefore be actively managed in patients on the waiting list and after transplantation. PMID:24964028

Schaefer, Benedikt; Effenberger, Maria; Zoller, Heinz

2014-11-01

70

Iron requirements in infancy.  

PubMed

Iron deficiency anemia is the most common micronutrient deficiency worldwide and infants constitute a risk group due to their high iron requirements. Iron is critical for brain development, and case control studies have shown a consistent association between iron deficiency anemia in infancy and poor neurodevelopment, suggesting that it is important to prevent iron deficiency anemia in infants. However, it is also important to avoid excessive iron intakes which may have adverse effects on growth. Due to redistribution of iron from hemoglobin to iron stores, healthy, term, normal birth weight infants are virtually self-sufficient with regard to iron during the first 6 months of life. After that age, iron becomes a critical nutrient. The estimated daily iron requirements at the age of 6-12 months (0.9-1.3 mg/kg body weight) are higher than during any other period of life. Exclusively breast-fed infants normally do not need additional iron until 6 months of life. Formula-fed infants should receive iron-fortified formula. Low birth weight infants should receive additional iron supplements from an early age. From 6 months of age, all infants should receive a sufficient intake of iron-rich (complementary) foods, which may be meat products or iron-fortified foods. The estimations of iron requirements in infants have a weak evidence base and current European and American recommendations for infants differ significantly. To further clarify iron requirements in infants, there is clearly a need for randomized, controlled trials assessing the effects of different iron intake on anemia, neurodevelopment, and other health outcomes. PMID:22123641

Domellöf, Magnus

2011-01-01

71

Iron and Diabetes Risk  

PubMed Central

Iron overload is a risk factor for diabetes. The link between iron and diabetes was first recognized in pathologic conditions—hereditary hemochromatosis and thalassemia—but high levels of dietary iron also impart diabetes risk. Iron plays a direct and causal role in diabetes pathogenesis mediated both by ?-cell failure and insulin resistance. Iron is also a factor in the regulation of metabolism in most tissues involved in fuel homeostasis, with the adipocyte in particular serving an iron-sensing role. The underlying molecular mechanisms mediating these effects are numerous and incompletely understood, but include oxidant stress and modulation of adipokines and intracellular signal transduction pathways. PMID:23473030

Simcox, Judith A.; McClain, Donald A.

2013-01-01

72

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 ...

73

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

74

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.

75

Iron nutrition in adolescence  

Microsoft Academic Search

Adolescence is an important period of nutritional vulnerability due to increased dietary requirements for growth and development. Iron needs are elevated as a result of intensive growth and muscular development, which implies an increase in blood volume; thus, it is extremely important for the adolescent's iron requirements to be met. Diet, therefore, must provide enough iron and, moreover, nutrients producing

MARTA MESÍAS; ISABEL SEIQUER; M. PILAR NAVARRO

2012-01-01

76

Iron-oxide catalyzed silicon photoanode for water splitting  

E-print Network

This thesis presents an integrated study of high efficiency photoanodes for water splitting using silicon and iron-oxide. The fundamental limitations of silicon to water splitting applications were overcome by an ultrathin ...

Jun, Kimin

2011-01-01

77

Molecular Structure of Iron  

NSDL National Science Digital Library

Since antiquity, Iron has been known for its malleability and abundance. Iron is a soft grey metal that is very ductile and easy to work; it can be rolled, hammered, bent, and tempered. Iron makes up 5% of the earth's crust in the form of ores such as hematite, limonite, magnetite, and taconite. This makes it the second most abundant metal, following aluminum. Most iron is used to manufacture carbon steel: iron with about 1.5% carbon and traces of other elements, but it is also used for many other alloys and steels of various types. Iron melts at 1808 degrees Kelvin and boils at 3023 degrees Kelvin. Insufficient iron in the bloodstream causes anemia, a medical condition causing unusual tiredness and other symptoms resulting from underdeveloped or few red blood cells.

2003-04-16

78

Iron and iron-based alloys for temporary cardiovascular applications.  

PubMed

In the last decade, biodegradable metals have emerged as a topic of interest for particular biomedical applications which require high strength to bulk ratio, including for cardiovascular stents. The advantages of biodegradable materials are related to the reduction of long term risks associated with the presence of permanent metal implants, e.g. chronic inflammation and in-stent restenosis. From a structural point of view, the analysis of the literature reveals that iron-based alloys used as temporary biodegradable stents have several advantages over Mg-based alloys in terms of ductility and strength. Efforts on the modification and tunability of iron-based alloys design and compositions have been mainly focused on controlling the degradation rate while retaining the mechanical integrity within a reasonable period. The early pre-clinical results of many iron-based alloys seem promising for future implants developments. This review discusses the available literature focusing mainly on: (i) Fe and Fe-based alloys design and fabrication techniques; (ii) in vitro and in vivo performance; (iii) cytotoxicity and cell viability tests. PMID:25716025

Francis, A; Yang, Y; Virtanen, S; Boccaccini, A R

2015-03-01

79

Case studies: iron1234  

PubMed Central

Iron biomarkers were developed to define the size of iron stores and the adequacy of the iron supply required to meet functional needs. Approximately 80% of the iron delivered to tissues through the circulating plasma pool will be incorporated into hemoglobin. Consequently, with the exception of serum ferritin, iron biomarkers are measures of iron sufficiency for erythrocyte production. They have proven to be very valuable in the determination of the cause of anemia in the clinical setting in which additional information about factors that affect the patient's health is available. However, all current biomarkers are affected by factors other than iron status, which limit their utility for the determination of the prevalence of iron deficiency in some populations, particularly in populations who live in developing countries. Furthermore, relations between iron status and functional outcomes such as neonatal and infant mortality; motor, cognitive, and emotional development in infants; and severe morbidity from malaria in young children are inadequately characterized. There is a need to identify and standardize biomarkers that have the highest predictive value for specific functional outcomes in each setting. The most appropriate biomarkers may vary with the setting and be influenced by age, sex, gestational stage of pregnancy, and environmental factors such as repeated or chronic infections. There is also an urgent need for improved technology to permit the use of specific biomarkers in field studies in resource-poor regions. Finally, more research is required to define the potential role of hepcidin and non–transferrin-bound iron assays. PMID:21733878

Lynch, Sean

2011-01-01

80

The ubiquity of iron.  

PubMed

The importance of iron in living systems can be traced to the many complexes within which it is found, to its chemical mobility in undergoing oxidation-reduction reactions, and to the abundance of iron in Earth's crust. Iron is the most abundant element, by mass, in the Earth, constituting about 80% of the inner and outer cores of Earth. The molten outer core is about 8000 km in diameter, and the solid inner core is about 2400 km in diameter. Iron is the fourth most abundant element in Earth's crust. It is the chemically functional component of mononuclear iron complexes, dinuclear iron complexes, [2Fe-2S] and [4Fe-4S] clusters, [Fe-Ni-S] clusters, iron protophorphyrin IX, and many other complexes in protein biochemistry. Metals such as nickel, cobalt, copper, and manganese are present in the crust and could in principle function chemically in place of iron, but they are scarce in Earth's crust. Iron is plentiful because of its nuclear stability in stellar nuclear fusion reactions. It seems likely that other solid planets, formed by the same processes as Earth, would also foster the evolution of life and that iron would be similarly important to life on those planets as it is on Earth. PMID:22845493

Frey, Perry A; Reed, George H

2012-09-21

81

Iron-Air Rechargeable Battery: A Robust and Inexpensive Iron-Air Rechargeable Battery for Grid-Scale Energy Storage  

SciTech Connect

GRIDS Project: USC is developing an iron-air rechargeable battery for large-scale energy storage that could help integrate renewable energy sources into the electric grid. Iron-air batteries have the potential to store large amounts of energy at low cost—iron is inexpensive and abundant, while oxygen is freely obtained from the air we breathe. However, current iron-air battery technologies have suffered from low efficiency and short life spans. USC is working to dramatically increase the efficiency of the battery by placing chemical additives on the battery’s iron-based electrode and restructuring the catalysts at the molecular level on the battery’s air-based electrode. This can help the battery resist degradation and increase life span. The goal of the project is to develop a prototype iron-air battery at significantly cost lower than today’s best commercial batteries.

None

2010-10-01

82

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

83

Iron and transfusion medicine.  

PubMed

Blood bankers have focused their energy to secure blood transfusion, and only recently have studies been published on the effect of blood donation on iron metabolism. In many facilities, hemoglobin measurement is only performed just before or even during blood donation, but the determination of iron stores is largely ignored. The 2013 paradox of transfusion medicine is due to the fact that blood donation may be harmful and leads to iron deficiency with or without anemia, but for other individuals, it may be a healthy measure preventing type 2 diabetes. The purpose of this review is to discuss iron metabolism in the perspective of blood donation, notably regarding their possible genetic profiles that eventually will discriminate "good" iron absorbers from "bad" iron responders. PMID:24148756

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

2013-11-01

84

Iron regulation by hepcidin  

PubMed Central

Hepcidin is a key hormone that is involved in the control of iron homeostasis in the body. Physiologically, hepcidin is controlled by iron stores, inflammation, hypoxia, and erythropoiesis. The regulation of hepcidin expression by iron is a complex process that requires the coordination of multiple proteins, including hemojuvelin, bone morphogenetic protein 6 (BMP6), hereditary hemochromatosis protein, transferrin receptor 2, matriptase-2, neogenin, BMP receptors, and transferrin. Misregulation of hepcidin is found in many disease states, such as the anemia of chronic disease, iron refractory iron deficiency anemia, cancer, hereditary hemochromatosis, and ineffective erythropoiesis, such as ?-thalassemia. Thus, the regulation of hepcidin is the subject of interest for the amelioration of the detrimental effects of either iron deficiency or overload. PMID:23722909

Zhao, Ningning; Zhang, An-Sheng; Enns, Caroline A.

2013-01-01

85

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

86

Iron (III) isomaltoside 1000.  

PubMed

Intravenous (iv.) iron is now the recommended treatment for iron deficiency anemia if oral preparations have failed or in those undergoing hemodialysis. Iron isomaltoside is a new iv. iron preparation, licensed since 2009 in the UK and Europe. The iron is tightly bound within a nonionic isomaltoside carbohydrate matrix, as opposed to most other iv. iron preparations that use branched polymers to form a carbohydrate shell. This conformation produces a low immunogenic potential, which allows high single-dose infusions to adequately replenish stores. Two Phase III, open-label, noncomparative, multicenter clinical trials have investigated the safety profile of iron isomaltoside in chronic kidney disease and chronic heart failure. Two serious adverse events were observed (Staphylococcus aureus sepsis and angina pectoris), although their relationship to the drug was questioned. Significant hemoglobin and serum ferritin rises were seen in the chronic kidney disease group. The chronic heart failure group showed a significant serum ferritin rise and improved 'overall quality of life' but a nonsignificant hemoglobin rise. Preparations of iv. iron can cause renal injury, possibly through oxidative stress. Modern preparations, such as iron isomaltoside and ferumoxytol, have demonstrated less free iron release and hence may theoretically cause less renal damage. The cost of iron isomaltoside is greater than some of the current standard preparations used in most hospitals in the UK and Europe. However, when overheads and patient throughput are calculated, it may be a more cost-effective therapy than current therapies in the UK, owing to its faster infusion rate. Currently, there remains limited data on efficacy, safety and cost-effectiveness. Although initial data are encouraging, they come from only three published small trials, thus restricting the conclusions that can be made. Future research needs to concentrate on comparative analyses with other iv. iron therapies. PMID:23782077

Mace, Thomas A R; Syed, Ahsan; Bhandari, Sunil

2013-06-01

87

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.

88

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

89

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

90

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

91

Physiology of iron metabolism.  

PubMed

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

2014-06-01

92

Erythropoietin, iron, and erythropoiesis.  

PubMed

Recent knowledge gained regarding the relationship between erythropoietin, iron, and erythropoiesis in patients with blood loss anemia, with or without recombinant human erythropoietin therapy, has implications for patient management. Under conditions of significant blood loss, erythropoietin therapy, or both, iron-restricted erythropoiesis is evident, even in the presence of storage iron and iron oral supplementation. Intravenous iron therapy in renal dialysis patients undergoing erythropoietin therapy can produce hematologic responses with serum ferritin levels up to 400 microg/L, indicating that traditional biochemical markers of storage iron in patients with anemia caused by chronic disease are unhelpful in the assessment of iron status. Newer measurements of erythrocyte and reticulocyte indices using automated counters show promise in the evaluation of iron-restricted erythropoiesis. Assays for serum erythropoietin and the transferrin receptor are valuable tools for clinical research, but their roles in routine clinical practice remain undefined. The availability of safer intravenous iron preparations allows for carefully controlled studies of their value in patients undergoing erythropoietin therapy or experiencing blood loss, or both. PMID:10910892

Goodnough, L T; Skikne, B; Brugnara, C

2000-08-01

93

Iron amino acid chelates.  

PubMed

Iron amino acid chelates, such as iron glycinate chelates, have been developed to be used as food fortificants and therapeutic agents in the prevention and treatment of iron deficiency anemia. Ferrous bis-glycine chelate (FeBC), ferric tris-glycine chelate, ferric glycinate, and ferrous bis-glycinate hydrochloride are available commercially. FeBC is the most studied and used form. Iron absorption from FeBC is affected by enhancers and inhibitors of iron absorption, but to a lesser extent than ferrous sulfate. Its absorption is regulated by iron stores. FeBC is better absorbed from milk, wheat, whole maize flour, and precooked corn flour than is ferrous sulfate. Supplementation trials have demonstrated that FeBC is efficacious in treating iron deficiency anemia. Consumption of FeBC-fortified liquid milk, dairy products, wheat rolls, and multi-nutrient beverages is associated with an improvement of iron status. The main limitations to the widespread use of FeBC in national fortification programs are the cost and the potential for promoting organoleptic changes in some food matrices. Additional research is required to establish the bioavailability of FeBC in different food matrices. Other amino acid chelates should also be evaluated. Finally there is an urgent need for more rigorous efficacy trials designed to define the relative merits of amino acid chelates when compared with bioavailable iron salts such as ferrous sulfate and ferrous fumarate and to determine appropriate fortification levels PMID:15743019

Hertrampf, Eva; Olivares, Manuel

2004-11-01

94

Iron and blood donation.  

PubMed

Regular blood donors undergo a progressive decline in iron reserves, while some develop frank iron-deficient erythropoiesis. The prevalence of iron depletion is significantly higher in menstruating women and increases progressively as the rate of donation increases. While conventional screening programmes based on the haemoglobin are adequate to prevent the development of progressive iron deficiency anaemia, they provide no indication of the development of tissue iron depletion. Recent studies indicate an impairment in a number of physiological processes associated with iron depletion but the liabilities of mild iron deficiency have not been fully defined. While it would be desirable to avoid iron depletion in regular blood donors only a minority of the eligible population have been willing to provide the blood resources of the USA in the past, and many individuals who can maintain high rates of donation without developing iron deficiency anaemia would be eliminated. However, there is little doubt that continued efforts should be made to encourage a broader base of volunteer donors. Improved public awareness of the need for blood has made it possible to obtain 88 per cent of the total supply from donors who gave blood three or less times during the year, and only 13.4 per cent of men and 11 per cent of women made three of more donations (Table 6). Further, women under 46 years of age constitute only 1 per cent of all donors who give four or more times during the year. Until clear-cut evidence is obtained of the deleterious effects of a lack of iron, the low prevalence of depleted iron reserves in men and non-menstruating women donors seems acceptable. However, current blood banking practices place a disproportionate iron demand on menstruating women. Because of the additional burden of pregnancy in this donor group, efforts to reduce the prevalence of a lack of iron in the child-bearing female should be encouraged. The simplest approach would be to limit the rate of blood donation to a maximum of three per year. This also is a subgroup among whom the application of more specific screening procedures for iron deficiency can clearly be justified. Iron supplementation programmes are also an attractive approach in these people who are likely to be highly motivated. Neither of these approaches have been adequately evaluated at the present time. PMID:6373083

Skikne, B; Lynch, S; Borek, D; Cook, J

1984-02-01

95

Safety of Iron Fortification and Supplementation in Malaria-Endemic Areas  

PubMed Central

This review considers the safety of iron supplementation and fortification for the prevention and correction of iron deficiency in malaria-endemic areas, with a focus on potential means whereby provision of additional iron might heighten the risks of malaria and other infections. Iron deficiency itself may increase the risk of morbidity and mortality from malaria and other infections. The available evidence indicates that iron interventions are safe in settings without endemic malaria, and, with adequate health care, in regions with high transmission of malaria and other infections. Without regular surveillance and treatment of malaria and other infections, iron supplementation of individuals who are iron deficient seems safe, but individuals who are iron replete may have an increased risk of adverse outcomes. The mechanisms responsible for harmful effects with iron supplementation have not been established. These are likely to include the effects of (a) increased amounts of absorbed iron, with the production of plasma non-transferrin-bound iron, (b) increased amounts of iron in the gastrointestinal tract, with effects on gastrointestinal structural integrity and on gut microflora, and (c) the complex immune effects of iron interventions. Iron fortification appears to be generally safe, although more data from malaria-endemic areas are needed.

Brittenham, Gary M.

2014-01-01

96

Intravenous Iron Sucrose for Children with Iron Deficiency Failing to Respond to Oral Iron Therapy  

PubMed Central

Background For decades parenteral iron has been used in patients with iron deficiency unresponsive to oral iron therapy and in hemodialysis-dependent patients receiving erythropoietin. Newer intravenous (IV) iron formulations such as iron sucrose have replaced high molecular weight iron dextran in dialysis patients; however, the use of parenteral iron in children without renal disease has not been well defined. Procedure Pharmacy records were reviewed on children (? 18 yrs of age) who received IV iron sucrose at Children's Medical Center Dallas between January 1, 2004 and June 30, 2009. Patients who received iron sucrose for chronic renal disease were excluded from analysis. Results Thirty-eight children received iron sucrose for non-renal indications, 13 with iron deficiency refractory to oral iron therapy, 13 with iron malabsorption or dependence on parenteral nutrition, 7 for chronic gastrointestinal blood loss, and 5 for miscellaneous indications. Among these 38 children, who received a total of 510 doses of IV iron sucrose, there were only 6 adverse reactions. Patients in all categories had a good response to the iron sucrose, with a median hemoglobin rise of 1.9 – 3.1 g/dl depending on the indication. Conclusions Parenteral iron is a safe and effective means to treat iron deficiency in children who cannot receive or do not respond to oral iron due to intolerance, poor adherence or iron malabsorption. PMID:21298748

Crary, Shelley E.; Hall, Katherine; Buchanan, George R.

2010-01-01

97

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

98

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

99

Thin Wall Iron Castings  

SciTech Connect

Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

2001-10-31

100

Iron complexed afterchrome dyes  

Microsoft Academic Search

The possibility of elimination of chromium in dye effluents during application of afterchrome dyes has been investigated. Eight commercially available azo mordant dyes were used in dyeing of wood fabric and aftertreated with iron (II) and iron (III) salts. Colour and lightfastness of received dyeings was compared with those obtained with the use of traditional chromium-aftertreated method. The structure of

Wojciech Czajkowski; Ma?gorzata Szymczyk

1998-01-01

101

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

Code of Federal Regulations, 2012 CFR

...measures: Cast iron and ductile iron pipelines. 192.489...STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. ...iron or ductile iron pipe on which general...

2012-10-01

102

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

Code of Federal Regulations, 2011 CFR

...measures: Cast iron and ductile iron pipelines. 192.489...STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. ...iron or ductile iron pipe on which general...

2011-10-01

103

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

Code of Federal Regulations, 2013 CFR

...measures: Cast iron and ductile iron pipelines. 192.489...STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. ...iron or ductile iron pipe on which general...

2013-10-01

104

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

Code of Federal Regulations, 2010 CFR

...measures: Cast iron and ductile iron pipelines. 192.489...STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. ...iron or ductile iron pipe on which general...

2010-10-01

105

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

Code of Federal Regulations, 2014 CFR

...measures: Cast iron and ductile iron pipelines. 192.489...STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. ...iron or ductile iron pipe on which general...

2014-10-01

106

Iron replacement therapy: assessing today's options to prepare for bundling.  

PubMed

New Medicare rules that set forth a revised reimbursement scheme for dialysis services will introduce significant changes for providers. The new rules will abandon the current system of separate reimbursement for drugs associated with the hemodialysis services, including erythropoiesis-stimulating agents (ESAs) and intravenous (i.v.) iron. These rules will "bundle" these agents and related laboratory tests into a single, case-mix adjusted composite rate. These bundling rules will be gradually phased-in, beginning in 2011. One of the primary effects of the new reimbursement policy will be to discourage over-utilization of ESAs that comprise nearly one-quarter of hemodialysis-related Medicare expenditures. As a result, hemodialysis providers will be challenged to make hemodialysis services more cost-effective, while ensuring that Medicare clinical performance measures are met and patient care is not compromised. i.v. iron has an integral role in making anemia care more cost-effective in the hemodialysis setting by improving measures of iron-deficiency anemia, maintaining necessary iron balance, and reducing the utilization of ESAs. This review discusses the potential benefits of i.v. iron in the management of hemodialysis patients with iron-deficiency anemia. It also focuses on the available i.v. iron options, particularly the established efficacy and safety profile of i.v. iron dextran compared with other i.v. iron formulations as well as cost considerations. PMID:20333988

Yee, Jerry

2010-02-01

107

Microbes: mini iron factories.  

PubMed

Microbes have flourished in extreme habitats since beginning of the Earth and have played an important role in geological processes like weathering, mineralization, diagenesis, mineral formation and destruction. Biotic mineralization is one of the most fascinating examples of how microbes have been influencing geological processes. Iron oxidizing and reducing bacteria are capable of precipitating wide varieties of iron oxides (magnetite), carbonates (siderite) and sulphides (greigite) via controlled or induced mineralization processes. Microbes have also been considered to play an important role in the history of evolution of sedimentary rocks on Earth from the formation of banded iron formations during the Archean to modern biotic bog iron and ochre deposits. Here, we discuss the role that microbes have been playing in precipitation of iron and the role and importance of interdisciplinary studies in the field of geology and biology in solving some of the major geological mysteries. PMID:25320452

Joshi, Kumar Batuk

2014-12-01

108

Iron studies in hemophilia  

SciTech Connect

Although iron deficiency is not recognized as a usual complication of hemophilia, we questioned whether intermittent occult loss of blood in urine or stool might predispose hemophiliacs to chronic iron deficiency. Seven men with factor VII and one with factor IX deficiency were studied. Blood studied, bone marrow aspirates, urine and stool samples, and ferrokinetics with total-body counting up to five months were examined. These data showed no excessive loss of blood during the study period; however, marrow iron stores were decidedly decreased, being absent in four subjects. We suggest that in some hemophiliacs, iron deposits in tissues such as synovial membranes may form a high proportion of the body's total iron stores.

Lottenberg, R.; Kitchens, C.S.; Roessler, G.S.; Noyes, W.D.

1981-12-01

109

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 ...

110

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

111

Serum iron analysis of adults receiving three different iron compounds  

Microsoft Academic Search

Iron deficiency is one of the most prevalent nutritional problems in the world. Iron compounds are used for the prevention and treatment of this deficiency. A double-blind randomized crossover study with 12 volunteers was carried out to compare the effect of three iron compounds, ferrous glycine chelate (GLY), ferric EDTA (EDTA), and ferrous sulfate (FS) on serum iron, and to

Luciana Ferreira da Silva; José E. Dutra-de-Oliveira; Júlio Sérgio Marchini

2004-01-01

112

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

113

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...

114

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)

2004-01-01

115

Iron therapy for renal anemia: how much needed, how much harmful?  

PubMed Central

Iron deficiency is the most common cause of hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) in end-stage renal disease (ESRD) patients. Iron deficiency can easily be corrected by intravenous iron administration, which is more effective than oral iron supplementation, at least in adult patients with chronic kidney disease (CKD). Iron status can be monitored by different parameters such as ferritin, transferrin saturation, percentage of hypochromic red blood cells, and/or the reticulocyte hemoglobin content, but an increased erythropoietic response to iron supplementation is the most widely accepted reference standard of iron-deficient erythropoiesis. Parenteral iron therapy is not without acute and chronic adverse events. While provocative animal and in vitro studies suggest induction of inflammation, oxidative stress, and kidney damage by available parenteral iron preparations, several recent clinical studies showed the opposite effects as long as intravenous iron was adequately dosed. Thus, within the recommended international guidelines, parenteral iron administration is safe. Intravenous iron therapy should be withheld during acute infection but not during inflammation. The integration of ESA and intravenous iron therapy into anemia management allowed attainment of target hemoglobin values in the majority of pediatric and adult CKD and ESRD patients. PMID:17206511

2007-01-01

116

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

117

Fluorescent bacteria detecting iron loading  

Microsoft Academic Search

Since iron pollution represents a real threat in the modern industrial era, while, in the meantime, the environment control using microorganisms has been developed, the present investigation was dedicated to iron sensing by means of bacterial cultures. Pseudomonas aeruginosa was chosen due to its ability to up-take the environmental iron in the form of complex iron compositions called siderophores, characterized

Antoniea Poiata; Alexandru Vlahovici; Dorina-Emilia Creanga; Petronela Tupu

2005-01-01

118

Coal desulfurization. [using iron pentacarbonyl  

NASA Technical Reports Server (NTRS)

Organic sulfur is removed from coal by treatment with an organic solution of iron pentacarbonyl. Organic sulfur compounds can be removed by reaction of the iron pentacarbonyl with coal to generate CO and COS off-gases. The CO gas separated from COS can be passed over hot iron fillings to generate iron pentacarbonyl.

Hsu, G. C. (inventor)

1979-01-01

119

Fracture behavior and microstructure of steel fiber reinforced cast iron  

Microsoft Academic Search

In this study, improvement of fracture toughness and strength of gray cast iron by reinforcing steel fiber was investigated.\\u000a Three point bend specimens were used to calculate the flexural strength and fracture toughness. Fracture toughness of the\\u000a reinforced cast iron with two distinct volume fraction (Vf = 0.05 and 0.08) were calculated by compliance method and J-integral method using single specimen technique.

Mehmet ?im?ir

2007-01-01

120

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

121

Iron deficiency and iron deficiency anemia in women.  

PubMed

Iron deficiency is one of the most common nutritional problems in the world and disproportionately affects women and children. Stages of iron deficiency can be characterized as mild deficiency where iron stores become depleted, marginal deficiency where the production of many iron-dependent proteins is compromised but hemoglobin levels are normal and iron deficiency anemia where synthesis of hemoglobin is decreased and oxygen transport to the tissues is reduced. Iron deficiency anemia is usually assessed by measuring hemoglobin levels but this approach lacks both specificity and sensitivity. Failure to identify and treat earlier stages of iron deficiency is concerning given the neurocognitive implications of iron deficiency without anemia. Most of the daily iron requirement is derived from recycling of senescent erythrocytes by macrophages; only 5-10 % comes from the diet. Iron absorption is affected by inhibitors and enhancers of iron absorption and by the physiological state. Inflammatory conditions, including obesity, can result in iron being retained in the enterocytes and macrophages causing hypoferremia as a strategic defense mechanism to restrict iron availability to pathogens. Premenopausal women usually have low iron status because of iron loss in menstrual blood. Conditions which further increase iron loss, compromise absorption or increase demand, such as frequent blood donation, gastrointestinal lesions, athletic activity and pregnancy, can exceed the capacity of the gastrointestinal tract to upregulate iron absorption. Women of reproductive age are at particularly high risk of iron deficiency and its consequences however there is a controversial argument that evolutionary pressures have resulted in an iron deficient phenotype which protects against infection. PMID:25083899

Coad, Jane; Pedley, Kevin

2014-01-01

122

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

123

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.

Anne Helmenstine --http://chemistry.about.com/cs/howtos/ht/ironfromcereal.htm Cristy Macias

124

Iron chelation, quo vadis?  

PubMed

Orally bioavailable chelators for transfusional iron overload have been sought since the introduction of deferoxamine (Desferal) in 1962. Despite tremendous efforts, to date, only deferiprone (Ferriprox) and deferasirox (Exjade) have successfully reached the market, reflecting the difficulty to combine oral activity and safety. Owing to the risk of failure, few new oral chelators can be expected in the future for the treatment of transfusional iron overload. As iron is involved in many disease processes, deferiprone and deferasirox have been proposed to be potentially useful in a variety of indications not characterized by general iron overload. Although it may be possible to obtain clinical benefit from current compounds, more selective chelators tailored to the particular target are needed for successful intervention in these indications. PMID:17644021

Nick, Hanspeter

2007-08-01

125

An update on iron physiology  

PubMed Central

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 loss may lead to iron deficiency (ID) and iron-deficiency anemia. Hepcidin, which is made primarily in hepatocytes in response to liver iron levels, inflammation, hypoxia and anemia, is the main iron regulatory hormone. Once secreted into the circulation, hepcidin binds ferroportin on enterocytes and macrophages, which triggers its internalization and lysosomal degradation. Thus, in chronic inflammation, the excess of hepcidin decreases iron absorption and prevents iron recycling, which results in hypoferremia and iron-restricted erythropoiesis, despite normal iron stores (functional ID), and anemia of chronic disease (ACD), which can evolve to ACD plus true ID (ACD + ID). In contrast, low hepcidin expression may lead to iron overload, and vice versa. Laboratory tests provide evidence of iron depletion in the body, or reflect iron-deficient red cell production. The appropriate combination of these laboratory tests help to establish a correct diagnosis of ID status and anemia. PMID:19787824

Muñoz, Manuel; Villar, Isabel; García-Erce, José Antonio

2009-01-01

126

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

127

Isocitrate ameliorates anemia by suppressing the erythroid iron restriction response  

PubMed Central

The unique sensitivity of early red cell progenitors to iron deprivation, known as the erythroid iron restriction response, serves as a basis for human anemias globally. This response impairs erythropoietin-driven erythropoiesis and underlies erythropoietic repression in iron deficiency anemia. Mechanistically, the erythroid iron restriction response results from inactivation of aconitase enzymes and can be suppressed by providing the aconitase product isocitrate. Recent studies have implicated the erythroid iron restriction response in anemia of chronic disease and inflammation (ACDI), offering new therapeutic avenues for a major clinical problem; however, inflammatory signals may also directly repress erythropoiesis in ACDI. Here, we show that suppression of the erythroid iron restriction response by isocitrate administration corrected anemia and erythropoietic defects in rats with ACDI. In vitro studies demonstrated that erythroid repression by inflammatory signaling is potently modulated by the erythroid iron restriction response in a kinase-dependent pathway involving induction of the erythroid-inhibitory transcription factor PU.1. These results reveal the integration of iron and inflammatory inputs in a therapeutically tractable erythropoietic regulatory circuit. PMID:23863711

Richardson, Chanté L.; Delehanty, Lorrie L.; Bullock, Grant C.; Rival, Claudia M.; Tung, Kenneth S.; Kimpel, Donald L.; Gardenghi, Sara; Rivella, Stefano; Goldfarb, Adam N.

2013-01-01

128

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

129

Cardioprotective activity of iron oxide nanoparticles  

PubMed Central

Iron oxide nanoparticles (IONPs) are chemically inert materials and have been mainly used for imaging applications and drug deliveries. However, the possibility whether they can be used as therapeutic drugs themselves has not yet been explored. We reported here that Fe2O3 nanoparticles (NPs) can protect hearts from ischemic damage at the animal, tissue and cell level. The cardioprotective activity of Fe2O3 NPs requires the integrity of nanoparticles and is not dependent upon their surface charges and molecules that were integrated into nanoparticles. Also, Fe2O3 NPs showed no significant toxicity towards normal cardiomyocytes, indicative of their potential to treat cardiovascular diseases. PMID:25716309

Xiong, Fei; Wang, Hao; Feng, Yidong; Li, Yunman; Hua, Xiaoqing; Pang, Xingyun; Zhang, Song; Song, Lina; Zhang, Yu; Gu, Ning

2015-01-01

130

Protein Degradation and Iron Homeostasis  

PubMed Central

Regulation of both systemic and cellular iron homeostasis requires the capacity to sense iron levels and appropriately modify the expression of iron metabolism genes. These responses are coordinated through the efforts of several key regulatory factors including F-box and Leucine-rich Repeat Protein 5 (FBXL5), Iron Regulatory Proteins (IRPs), Hypoxia Inducible Factor (HIF), and ferroportin. Notably, the stability of each of these proteins is regulated in response to iron. Recent discoveries have greatly advanced our understanding of the molecular mechanisms governing iron-sensing and protein degradation within these pathways. It has become clear that iron’s privileged roles in both enzyme catalysis and protein structure contribute to its regulation of protein stability. Moreover, these multiple pathways intersect with one another in larger regulatory networks to maintain iron homeostasis. PMID:22349011

Thompson, Joel W.; Bruick, Richard K.

2013-01-01

131

Iron loading and disease surveillance.  

PubMed Central

Iron is an oxidant as well as a nutrient for invading microbial and neoplastic cells. Excessive iron in specific tissues and cells (iron loading) promotes development of infection, neoplasia, cardiomyopathy, arthropathy, and various endocrine and possibly neurodegenerative disorders. To contain and detoxify the metal, hosts have evolved an iron withholding defense system, but the system can be compromised by numerous factors. An array of behavioral, medical, and immunologic methods are in place or in development to strengthen iron withholding. Routine screening for iron loading could provide valuable information in epidemiologic, diagnostic, prophylactic, and therapeutic studies of emerging infectious diseases. PMID:10341171

Weinberg, E. D.

1999-01-01

132

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

133

Mammalian iron metabolism and its control by iron regulatory proteins?  

PubMed Central

Cellular iron homeostasis is maintained by iron regulatory proteins 1 and 2 (IRP1 and IRP2). IRPs bind to iron-responsive elements (IREs) located in the untranslated regions of mRNAs encoding protein involved in iron uptake, storage, utilization and export. Over the past decade, significant progress has been made in understanding how IRPs are regulated by iron-dependent and iron-independent mechanisms and the pathological consequences of IRP2 deficiency in mice. The identification of novel IREs involved in diverse cellular pathways has revealed that the IRP–IRE network extends to processes other than iron homeostasis. A mechanistic understanding of IRP regulation will likely yield important insights into the basis of disorders of iron metabolism. This article is part of a Special Issue entitled: Cell Biology of Metals. PMID:22610083

Anderson, Cole P.; Shen, Lacy; Eisenstein, Richard S.; Leibold, Elizabeth A.

2013-01-01

134

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

135

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

136

Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria  

Microsoft Academic Search

Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent iron-oxidizing bacterium Acidovorax sp. strain BoFeN1 in the presence of dissolved Fe(II) using electron microscopy and Scanning Transmission X-ray Microscopy (STXM).

Jennyfer Miot; Karim Benzerara; Guillaume Morin; Andreas Kappler; Sylvain Bernard; Martin Obst; Céline Férard; Fériel Skouri-Panet; Jean-Michel Guigner; Nicole Posth; Matthieu Galvez; Gordon E. Brown; François Guyot

2009-01-01

137

Iron-Deficiency Anemia (For Parents)  

MedlinePLUS

... high in iron. Kids or teens on a vegetarian diet also might not get enough iron, because iron ... Multivitamins with iron and changes to a child's diet can help, but usually are not enough on ... Anemia Word! Anemia About Anemia ...

138

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 .

139

Iron Science Teacher!  

NSDL National Science Digital Library

Every weekend during the summer, crowds gather at San Francisco's Exploratorium to watch the "Iron Science Teacher" game. Based on the wildly popular Japanese TV show, Iron Chef, in which chefs compete to see who can whip up the most creative and delicious meal with the day's "secret ingredient," Iron Science Teacher asks primary and secondary science educators to whip up a science lesson based on a "secret ingredient" -- be it PVC pipe, pantyhose, toothpicks or even marshmallow peeps! The goal of the project is to celebrate science education and to demonstrate that teachers can teach the $10 million state science standards on a $10 budget. Web surfers who can't make it to the Exploratorium can view this wacky yet totally educational program online. An archive of 25 broadcasts from June 1999 to the present is available (RealPlayer).

140

INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS ...  

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

INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS FROM CUPOLA TO IRON TREATMENT AREAS BEFORE BEING TRANSFERRED TO PIPE CASTING MACHINES. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

141

Iron absorption of ferric glycinate is controlled by iron stores  

Microsoft Academic Search

Ferric glycinate bioavailability and its absorption control by iron stores was assessed by radioisotopic studies in 30 subjects (17 women and 13 men), in apparent good health, of normal iron status and of high socioeconomic level. Absorption studies used ferric glycinate labeled intrinsically during the synthesis process of this compound as a tracer. In two groups of 15 subjects, iron

Fernando Pizarro; Raúl Uicich; Manuel Olivares; Carlos Almeida; Mará L. Díaz; Esteban Carmuega; Alejandro O'Donnell; Mirta E Valencia

1998-01-01

142

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

143

Iron and Steel Phosphate Rock  

E-print Network

Phosphate Rock Platinum Potash Pumice Quartz Crystal Rare Earths Rhenium Rubidium Salt Sand and Gravel Cadmium Iodine Pumice Thorium Cement Iron Ore Quartz Crystal Tin Cesium Iron and Steel Rare Earths

Torgersen, Christian

144

Iron deficiency: definition and diagnosis.  

PubMed

There has been a continuous refinement over the past several decades of methods to detect iron deficiency and assess its magnitude. The optimal combination of measurements differs for clinical and epidemiological assessment. Clinically, the major problem is to distinguish true iron deficiency from other causes of iron-deficient erythropoiesis, such as the anaemia of chronic disease. Epidemiologically, techniques that provide quantified estimates of body iron are preferable. For both purposes, the serum ferritin is the focal point of the laboratory detection of iron deficiency. Serum ferritin measurements provide a reliable index of body iron stores in healthy individuals, a cost-effective method of screening for iron deficiency, and a useful alternative to bone marrow examinations in the evaluation of anaemic patients. Preliminary studies indicate that measurement of the serum transferrin receptor may be the most reliable way to assess deficits in tissue iron supply. PMID:2681511

Cook, J D; Skikne, B S

1989-11-01

145

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

146

Iron diffusion in iron-aluminate spinels  

SciTech Connect

The diffusion coefficient of /sup 59/Fe in iron-aluminate spinels (Fe/sub 3/O/sub 4/-FeAl/sub 2/O/sub 4/) was measured by serial sectioning. The results were analyzed with a defect model, assuming that the predominant defects were cation vacancies and interstitials. At 1380/sup 0/C, diffusion occurs in Fe/sub 3/O/sub 4/ and Fe(Fe/sub 1/ /sub 51/Al/sub 0/ /sub 49/)O/sub 4/ by an interstitial mechanism at low P/sub O/sub 2// and a vacancy mechanism at high P/sub O/sub 2//. Diffusion of iron is by the vacancy mechanism for higher hercynite concentrations, except that the results for the end-member, FeAl/sub 2/O/sub 4/, suggest an interstitial mechanism. At 10/sup -6/ atm O/sub 2/, and Arrhenius plot of D/sub Fe/ exhibits a minimum for Fe/sub 3/O/sub 4/ and Fe(Fe/sub 1/ /sub 51/Al/sub 0/ /sub 49/)O/sub 4/. This effect is explained in terms of a mechanism change. The D/sub Fe/ is essentially independent of temperature in Fe(Fe/sub 1/ /sub 03/Al/sub 0/ /sub 97/)O/sub 4/ and Fe(Fe/sub 0/ /sub 54/Al/sub 1/ /sub 46/)O/sub 4/.

Halloran, J.W.; Bowen, H.K.

1980-01-01

147

Mitochondrial iron accumulation with age and functional consequences  

PubMed Central

Summary During the aging process, an accumulation of non-heme iron disrupts cellular homeostasis and contributes to the mitochondrial dysfunction typical of various neuromuscular degenerative diseases. Few studies have investigated the effects of iron accumulation on mitochondrial integrity and function in skeletal muscle and liver tissue. Thus, we isolated liver mitochondria (LM), as well as quadriceps-derived subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM), from male Fischer 344× Brown Norway rats at 8, 18, 29 and 37 months of age. Non-heme iron content in SSM, IFM and LM was significantly higher with age, reaching a maximum at 37 months of age. The mitochondrial permeability transition pore (mPTP) was more susceptible to the opening in aged mitochondria containing high levels of iron (i.e. SSM and LM) compared to IFM. Furthermore, mitochondrial RNA oxidation increased significantly with age in SSM and LM, but not in IFM. Levels of mitochondrial RNA oxidation in SSM and LM correlated positively with levels of mitochondrial iron, whereas a significant negative correlation was observed between the maximum Ca2+ amounts needed to induce mPTP opening and iron contents in SSM, IFM and LM. Overall, our data suggest that age-dependent accumulation of mitochondrial iron may increase mitochondrial dysfunction and oxidative damage, thereby enhancing the susceptibility to apoptosis. PMID:18843794

Seo, Arnold Y.; Xu, Jinze; Servais, Stephane; Hofer, Tim; Marzetti, Emanuele; Wohlgemuth, Stephanie E.; Knutson, Mitchell D.; Chung, Hae Young; Leeuwenburgh, Christiaan

2013-01-01

148

Iron excretion in iron dextran-overloaded mice  

PubMed Central

Background Iron homeostasis in humans is tightly regulated by mechanisms aimed to conserve iron for reutilisation, with a negligible role played by excretory mechanisms. In a previous study we found that mice have an astonishing ability to tolerate very high doses of parenterally administered iron dextran. Whether this ability is linked to the existence of an excretory pathway remains to be ascertained. Materials and methods Iron overload was generated by intraperitoneal injections of iron dextran (1 g/kg) administered once a week for 8 weeks in two different mouse strains (C57bl/6 and B6D2F1). Urinary and faecal iron excretion was assessed by inductively coupling plasma-mass spectrometry, whereas cardiac and liver architecture was evaluated by echocardiography and histological methods. For both strains, 24-hour faeces and urine samples were collected and iron concentration was determined on days 0, 1 and 2 after iron administration. Results In iron-overloaded C57bl/6 mice, the faecal iron concentration increased by 218% and 157% on days 1 and 2, respectively (p<0.01). The iron excreted represented a loss of 14% of total iron administered. Similar but smaller changes was also found in B6D2F1 mice. Conversely, we found no significant changes in the concentration of iron in the urine in either of the strains of mice. In both strains, histological examination showed accumulation of iron in the liver and heart which tended to decrease over time. Conclusions This study indicates that mice have a mechanism for removal of excess body iron and provides insights into the possible mechanisms of excretion. PMID:24960657

Musumeci, Marco; Maccari, Sonia; Massimi, Alessia; Stati, Tonino; Sestili, Paola; Corritore, Elisa; Pastorelli, Augusto; Stacchini, Paolo; Marano, Giuseppe; Catalano, Liviana

2014-01-01

149

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, iron pills are not often needed. If you choose to take a daily multivitamin-mineral, be sure, or pregnant women may need a daily multivitamin-mineral with 18 mg iron (more is needed for pregnant women

Wisconsin at Madison, University of

150

Replacing London's cast iron mains  

Microsoft Academic Search

This paper discusses the cast iron gas distribution systems that exist in many cities and contains considerable amounts of pipe that vary in age from 20 to 150 years. In many ways, cast iron is an excellent material. It is inherently corrosion resistant, easy to install and cheap. However, it is also brittle and smaller diameter cast iron pipe has

A. Thorne; P. Mathews

1992-01-01

151

Iron deficiency and cognitive functions  

PubMed Central

Micronutrient deficiencies, especially those related to iodine and iron, are linked to different cognitive impairments, as well as to potential long-term behavioral changes. Among the cognitive impairments caused by iron deficiency, those referring to attention span, intelligence, and sensory perception functions are mainly cited, as well as those associated with emotions and behavior, often directly related to the presence of iron deficiency anemia. In addition, iron deficiency without anemia may cause cognitive disturbances. At present, the prevalence of iron deficiency and iron deficiency anemia is 2%–6% among European children. Given the importance of iron deficiency relative to proper cognitive development and the alterations that can persist through adulthood as a result of this deficiency, the objective of this study was to review the current state of knowledge about this health problem. The relevance of iron deficiency and iron deficiency anemia, the distinction between the cognitive consequences of iron deficiency and those affecting specifically cognitive development, and the debate about the utility of iron supplements are the most relevant and controversial topics. Despite there being methodological differences among studies, there is some evidence that iron supplementation improves cognitive functions. Nevertheless, this must be confirmed by means of adequate follow-up studies among different groups. PMID:25419131

Jáuregui-Lobera, Ignacio

2014-01-01

152

The Iron Stimulon and Fur Regulon of Geobacter sulfurreducens and Their Role in Energy Metabolism  

PubMed Central

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

2014-01-01

153

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

154

Acquisition of iron by Legionella pneumophila: role of iron reductase.  

PubMed Central

Legionella pneumophila has been shown to survive and multiply in a variety of intracellular environments, including protozoa and human mononuclear phagocytes. However, the mechanism by which this organism acquires iron in the intracellular environment has not been studied. Since L. pneumophila does not produce siderophores, alternative methods of iron acquisition were investigated. Virulent strains of L. pneumophila were able to grow in media containing as little as 3 microM iron, whereas avirulent cells required a minimum of 13 microM iron for growth. Neither virulent nor avirulent cells were able to utilize 55Fe bound to transferrin. When incubated in the presence of 55Fe in the form of ferric chloride, both virulent and avirulent cells accumulated equal amounts of iron. The uptake of iron was energy dependent as indicated by inhibition of 55Fe uptake at 4 degrees C and preincubation of the cells with KCN. Treatment of virulent cells with pronase or trypsin had no effect on iron uptake. In contrast, pronase or trypsin treatment of avirulent cells resulted in increased uptake of iron. Iron reductase activity in both virulent and avirulent cells was demonstrated, with the highest specific activity associated with the periplasmic fraction. Maximum reductase activity of virulent cells occurred with NADH as the reductant. In contrast, avirulent cells showed a twofold increase in enzyme activity when NADPH was used as the reductant. These results suggest that an iron reductase is important in iron acquisition by L. pneumophila. PMID:1904841

Johnson, W; Varner, L; Poch, M

1991-01-01

155

Extracting Iron from Cereal.  

ERIC Educational Resources Information Center

Describes an activity in which students can investigate and evaluate the amount of iron found in most fortified breakfast cereals or cream of wheat. Includes a list of necessary materials, safety precautions, experimental procedure, disposal protocol, and nutritional explanation, utilization, and variations. (JJK)

Katz, David A.

1992-01-01

156

Iron, transferrin and myelinogenesis  

NASA Astrophysics Data System (ADS)

Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5 ' and 3 ' untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport.

Sergeant, C.; Vesvres, M. H.; Devès, G.; Baron, B.; Guillou, F.

2003-09-01

157

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

158

Iron Chelation Therapy  

MedlinePLUS

... in a moderate dose, such as 100 mg daily. One additional iron chelator is currently being used in Europe, Asia, and Canada, but is not yet approved by the FDA for use in the United States: Deferiprone or L1 (FerriproxTM) comes in a pill form and is taken 3 times a day. ...

159

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

160

Britain, South Africa and the Entente Internationale de L'Acier: The development of the South African iron and steel industry 1934–1945  

Microsoft Academic Search

The development of the iron and steel industry in South Africa, late by comparison with the other Dominions and India, began in earnest with the formation of the South African Iron and Steel Corporation (Iscor) in 1928. Iscor, under the direction of Dr H.J. van der Bijl, built an integrated iron and steel plant at Pretoria West which was opened

Tim Cross

1994-01-01

161

Ferrioxamine excretion in iron-loaded man  

SciTech Connect

Factors affecting iron excretion after subcutaneous desferrioxamine infusion were evaluated in individuals with iron overload. Urinary iron varied directly, whereas stool iron varied inversely with the level of erythropoiesis. Ascorbic acid greatly enhanced urinary iron excretion but had a less constant effect on stool iron. Stool iron losses contributed a greater proportion of total iron excretion at higher chelator dosage. These studies indicate the importance of biliary iron excretion in monitoring the effectiveness of desferrioxamine. They also suggest that large chelator doses may remove established iron overload much more rapidly than has previously been realized.

Pippard, M.J. (Univ. of Washington, Seattle); Callender, S.T.; Finch, C.A.

1982-08-01

162

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

163

[Iron and invasive fungal infection].  

PubMed

Iron is an essential factor for both the growth and virulence of most of microorganisms. As a part of the innate (or nutritional) immune system, mammals have developed different mechanisms to store and transport this element in order to limit free iron bioavailability. To survive in this hostile environment, pathogenic fungi have specific uptake systems for host iron sources, one of the most important of which is based on the synthesis of siderophores-soluble, low-molecular-mass, high-affinity iron chelators. The increase in free iron that results from iron-overload conditions is a well-established risk factor for invasive fungal infection (IFI) such as mucormycosis or aspergillosis. Therefore, iron chelation may be an appealing therapeutic option for these infections. Nevertheless, deferoxamine -the first approved iron chelator- paradoxically increases the incidence of IFI, as it serves as a xeno-siderophore to Mucorales. On the contrary, the new oral iron chelators (deferiprone and deferasirox) have shown to exert a deleterious effect on fungal growth both in vitro and in animal models. The present review focuses on the role of iron metabolism in the pathogenesis of IFI and summarises the preclinical data, as well as the limited clinical experience so far, in the use of new iron chelators as treatment for mucormycosis and invasive aspergillosis. PMID:23684655

Álvarez, Florencio; Fernández-Ruiz, Mario; Aguado, José María

2013-01-01

164

Nanophase iron phosphate, iron arsenate, iron vanadate, and iron molybdate minerals synthesized within the protein cage of ferritin.  

PubMed

Nanoparticles of iron phosphate, iron arsenate, iron molybdate, and iron vanadate were synthesized within the 8 nm interior of ferritin. The synthesis involved reacting Fe(II) with ferritin in a buffered solution at pH 7.4 in the presence of phosphate, arsenate, vanadate, or molybdate. O2 was used as the oxidant to deposit the Fe(III) mineral inside ferritin. The rate of iron incorporation into ferritin was stimulated when oxo-anions were present. The simultaneous deposition of both iron and the oxo-anion was confirmed by elemental analysis and energy-dispersive X-ray analysis. The ferritin samples containing iron and one of the oxo-anions possessed different UV/vis spectra depending on the anion used during mineral formation. TEM analysis showed mineral cores with approximately 8 nm mineral particles consistent with the formation of mineral phases inside ferritin. PMID:15847428

Polanams, Jup; Ray, Alisha D; Watt, Richard K

2005-05-01

165

Intestinal regulation of body iron.  

PubMed

A significant proportion of the world's population suffers from iron deficiency or iron overload. These disorders arise primarily from defects in the gastrointestinal absorption of iron. The intestinal mucosal cell plays a key role in this process because it lies at the interface between the gastrointestinal lumen which supplies its iron and body compartments which control its behaviour. The concentration of mucosal ferritin is closely linked to absorption, but it is still not clear whether it plays an active or a passive role. Transferrin also has been detected in the mucosal cell, but firm evidence that it participates in the absorptive process is lacking. Deficiencies in the luminal phase are responsible for the high global prevalence of iron deficiency which is predominantly dietary in origin. Much information has accumulated in recent years on dietary factors that enhance or impair iron absorption but their quantitative importance as determinants of iron status remains to be determined. PMID:3332111

Cook, J D; Skikne, B S

1987-12-01

166

ASSESSMENT OF SURFACE RUNOFF FROM IRON AND STEEL MILLS  

EPA Science Inventory

The report gives results of a program to determine if surface runoff from iron and steel mills is an environmental problem. It includes a compilation of data available before this program, information gathered from plant tours, and results of a field survey at two fully integrate...

167

Blood withdrawal affects iron store dynamics in primates with consequences on monoaminergic system function.  

PubMed

Iron homeostasis is essential for the integrity of brain monoaminergic functions and its deregulation might be involved in neurological movement disorders such as the restless legs syndrome (RLS). Although iron metabolism breakdown concomitantly appears with monoaminergic system dysfunction in iron-deficient rodents and in RLS patients, the direct consequences of peripheral iron deficiency in the central nervous system (CNS) of non-human primates have received little attention. Here, we evaluated the peripheral iron-depletion impact on brain monoamine levels in macaque monkeys. After documenting circadian variations of iron and iron-related proteins (hemoglobin, ferritin and transferrin) in both serum and cerebrospinal fluid (CSF) of normal macaques, repeated blood withdrawals (RBW) were used to reduce peripheral iron-related parameter levels. Decreased serum iron levels were paradoxically associated with increased CSF iron concentrations. Despite limited consequences on tissue monoamine contents (dopamine - DA, 3, 4-dihydroxyphenylacetic acid - DOPAC, homovanillic acid, L-3, 4-dihydroxyphenylalanine - L-DOPA, 5-8 hydroxytryptamine - 5-HT, 5-hydroxyindoleacetic acid - 5-HIAA and noradrenaline) measured with post-mortem chromatography, we found distinct and region-dependent relationships of these tissue concentrations with CSF iron and/or serum iron and/or blood hemoglobin. Additionally, striatal extracellular DA, DOPAC and 5-HIAA levels evaluated by in vivo microdialysis showed a substantial increase, suggesting an overall increase in both DA and 5-HT tones. Finally, a trending increase in general locomotor activity, measured by actimetry, was observed in the most serum iron-depleted macaques. Taken together, our data are compatible with an increase in nigrostriatal DAergic function in the event of iron deficiency and point to a specific alteration of the 5-HT/DA interaction in the CNS that is possibly involved in the etiology of RLS. PMID:25662508

Hyacinthe, C; De Deurwaerdere, P; Thiollier, T; Li, Q; Bezard, E; Ghorayeb, I

2015-04-01

168

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

169

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

170

Measurement of iron absorption from meals contaminated with iron  

SciTech Connect

A method is described to measure in vitro the extent of isotopic exchange between the native nonheme food iron and added inorganic reduction to radioiron tracer. The food is digested with pepsin and trypsin in the presence of radioiron. The exchangeability of food iron is calculated from the specific activity in the food and in an extract of bathophenantroline in isoamyl alcohol obtained after digesting this food. The precision and accuracy of the method is illustrated by two kinds of studies, those in which different amounts of contamination iron are added to a meal and those evaluating contamination iron in natural meals. The present method will make it possible to measure validly iron absorption from meals contaminated with unknown amounts of iron of unknown exchangeability with the extrinsic radioiron tracer.

Hallberg, L.; Bjoern-Rasmussen, E.

1981-12-01

171

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

172

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

173

Spin state of iron--the control parameter of iron-containing HTSC: Dependence of ground state energy, phonon energies and atom positions on the spin state of iron ion in FeTe  

NASA Astrophysics Data System (ADS)

The density functional theory was applied to calculate the electronic structure, ground state energy, phonon frequencies at the center and at the boundary of the Brillouin zone, as well as the distribution of magnetic moment over d-orbitals of iron in the magnetically ordered phase of FeTe as functions of the magnetic moment—spin state of iron. It was shown that the ground state energy minimum is achieved at a certain distribution of the magnetic moment over d-orbitals and at a certain spin state of the iron ion. The impact of the new type of interaction ("the spin state-lattice" interaction) on the phonon subsystem was studied numerically. It was found that the high-frequency part of the phonon spectra undergoes the most significant changes upon changing the spin state. To describe the properties of iron-containing HTSC compounds, an integral parameter (spin state of iron ion) was suggested.

Pashkevich, Yu. G.; Shevtsova, T. N.; Gusev, A. A.; Gnezdilov, V. P.; Lemmens, P.

2012-09-01

174

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

175

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

176

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

177

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

Code of Federal Regulations, 2014 CFR

...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

178

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation... § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line...

2010-10-01

179

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

180

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

181

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

182

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

183

Mitoferrin is essential for erythroid iron assimilation  

Microsoft Academic Search

Iron has a fundamental role in many metabolic processes, including electron transport, deoxyribonucleotide synthesis, oxygen transport and many essential redox reactions involving haemoproteins and Fe-S cluster proteins. Defective iron homeostasis results in either iron deficiency or iron overload. Precise regulation of iron transport in mitochondria is essential for haem biosynthesis, haemoglobin production and Fe-S cluster protein assembly during red cell

George C. Shaw; John J. Cope; Liangtao Li; Kenneth Corson; Candace Hersey; Gabriele E. Ackermann; Babette Gwynn; Amy J. Lambert; Rebecca A. Wingert; David Traver; Nikolaus S. Trede; Bruce A. Barut; Yi Zhou; Emmanuel Minet; Adriana Donovan; Alison Brownlie; Rena Balzan; Mitchell J. Weiss; Luanne L. Peters; Jerry Kaplan; Leonard I. Zon; Barry H. Paw

2006-01-01

184

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

185

Sphingolipid Signaling Mediates Iron Toxicity  

PubMed Central

Summary Iron constitutes a major source of toxicity due to its ability to generate reactive oxygen species that can damage cellular macromolecules. However the precise mechanism by which exposure to high iron concentrations results in cellular toxicity remains unknown. Here we identify sphingolipid synthesis and signaling as a major mediator of iron toxicity in S. cerevisiae. Inhibition of sphingolipid synthesis by myriocin treatment or after overexpression of the negative regulator Orm2p confers resistance to high iron. High iron conditions upregulate sphingolipid synthesis, and increasing sphingolipid levels by inactivating Orm2p exacerbates sensitivity to iron. Toxicity is mediated by sphingolipid signaling, as inactivation of the sphingolipid-activated protein kinases Pkh1p and Ypk1p and of the transcription factor Smp1p also enhances resistance to high iron conditions. These results demonstrate an unexpected connection between sphingolipid flux and iron toxicity, and show that activation of a signal transduction cascade contributes to iron-mediated cellular toxicity. PMID:22768841

Lee, Yueh-Jung; Huang, Xinhe; Kropat, Janette; Henras, Anthony; Merchant, Sabeeha S; Dickson, Robert C; Chanfreau, Guillaume F.

2012-01-01

186

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

187

Advances in hybrid organic\\/inorganic optoelectronic integration  

Microsoft Academic Search

We report on advances in the hybrid organic\\/inorganic integration of passive and active optical functions. The integration approaches include chip-to-chip attach, flip-chip mounting, and insertion of films in slots formed in planar lightwave circuits. The materials integrated include polymer, silica, silicon, silicon oxynitride, lithium niobate, indium phosphide, gallium arsenide, yttrium iron garnet, and neodymium iron boron. The functions enabled by

Louay A. Eldada; Antonije M. Radojevic; Junichiro Fujita; Tomoyuki Izuhara; Reinald Gerhardt

2004-01-01

188

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

189

The Iron Project: Atomic Data for the Iron Peak Elements  

Microsoft Academic Search

Emission and absorption lines from Iron ions are of great importance as diagnostics for a large variety of objects and in most wavelength ranges, from the X-ray and extreme UV up to the far IR. We report large-scale computations of photoionization cross sections, transition probabilities and collision strengths, under the auspices of an international collaboration known as the Iron Project

Anil K. Pradhan; Hong Lin Zhang; Jianfang Peng; Sultana N. Nahar; Manuel A. Bautista

1995-01-01

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. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

191

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

192

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...

193

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2014 CFR

...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

194

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

195

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

196

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

197

49 CFR 230.91 - Chafing irons.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 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...

2014-10-01

198

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

199

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

200

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

201

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

202

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

203

FastStats: Anemia or Iron Deficiency  

MedlinePLUS

... What's this? Submit Button NCHS Home Anemia or Iron Deficiency Recommend on Facebook Tweet Share Compartir Data ... for the U.S. Morbidity Percent of persons with iron deficiency (based on the body iron model): Children ...

204

Iron in spleen tissues  

NASA Astrophysics Data System (ADS)

This contribution aims in characterization of structural positions of iron in human and horse spleen. 57Fe Mössbauer spectroscopy was employed as a principal method of investigation in addition to X-ray diffraction and transmission electron microscopy (TEM). At room temperature, ferritin nanoparticles exhibit superparamagnetic behavior due to their small dimensions. Corresponding Mössbauer spectra show doublet-like patterns. Experiments performed at low temperatures unveiled presence of magnetically split components and enabled to determine the blocking temperature. Dimensions of Fe-containing species were established from detailed analyses of TEM images.

Miglierini, M.; Dekan, J.; Kopani, M.; Lancok, A.; Kohout, J.; Cieslar, M.

2012-10-01

205

The Iron Within  

NSDL National Science Digital Library

Forty-fifth monthly installment of our "What A Year!" website project, introducing life science breakthroughs to middle and high school students and their teachers. In order to cause infection, pathogenic bacteria must be able to obtain all the nutrients they need from the human body, including metals such as zinc, iron, and manganese. As a result, many vertebrate species (including humans) have evolved ways to store these metals in forms that are not readily accessible to bacteria. This mechanism is known as nutritional immunity. Staphylococcus aureus has developed such a mechanism, making it a very successful invader.

2011-02-01

206

Corrosion of Iron Experiment  

NSDL National Science Digital Library

The Materials Science and Technology Teacher's Workshop (MAST) provides this demonstration on corrosion. The laboratory exercise will allow students the opportunity to "observe the electrochemical nature of the changes in an iron nail when it corrodes and to investigate methods to protect it." Ways of preventing corrosion include protecting the metal with a more active metal and excluding oxygen and moisture from the material's surface with a protective coating. The lesson includes a step by step explanation of the laboratory procedure, discussion questions and teacher notes.

207

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

208

Iron overload in paediatrics undergoing cardiopulmonary bypass.  

PubMed

Pathological changes in iron status are known to occur during bypass and will be superimposed upon physiological abnormalities in iron distribution, characteristic of the neonatal period. We have sought to define the severity of iron overload in these patients. Plasma samples from 65 paediatric patients undergoing cardiopulmonary bypass (CPB) were analysed for non-haem iron, total iron binding capacity, transferrin and bleomycin-detectable iron. Patients were divided into four age groups for analysis. Within each age group, patients who were in iron overload at any time point were statistically compared to those who were not. The most significant changes in iron chemistry were seen in the plasma of neonates, with 25% in a state of plasma iron overload. 18.5% of infants and 14.3% of children at 1-5 years were also in iron overload at some time point during CPB. No children over 5 years, however, went into iron overload. Increased iron saturation of transferrin eliminates its ability to bind reactive forms of iron and to act as an antioxidant. When transferrin is fully saturated with iron, reactive forms of iron are present in the plasma which can stimulate iron-driven oxidative reactions. Our data suggest that paediatric patients are at greater risk of iron overload during CPB, and that some form of iron chelation therapy may be advantageous to decrease oxidative stress. PMID:10699376

Mumby, S; Chaturvedi, R R; Brierley, J; Lincoln, C; Petros, A; Redington, A N; Gutteridge, J M

2000-03-17

209

The Pharmacokinetics and Pharmacodynamics of Iron Preparations  

PubMed Central

Standard approaches are not appropriate when assessing pharmacokinetics of iron supplements due to the ubiquity of endogenous iron, its compartmentalized sites of action, and the complexity of the iron metabolism. The primary site of action of iron is the erythrocyte, and, in contrast to conventional drugs, no drug-receptor interaction takes place. Notably, the process of erythropoiesis, i.e., formation of new erythrocytes, takes 3–4 weeks. Accordingly, serum iron concentration and area under the curve (AUC) are clinically irrelevant for assessing iron utilization. Iron can be administered intravenously in the form of polynuclear iron(III)-hydroxide complexes with carbohydrate ligands or orally as iron(II) (ferrous) salts or iron(III) (ferric) complexes. Several approaches have been employed to study the pharmacodynamics of iron after oral administration. Quantification of iron uptake from radiolabeled preparations by the whole body or the erythrocytes is optimal, but alternatively total iron transfer can be calculated based on known elimination rates and the intrinsic reactivity of individual preparations. Degradation kinetics, and thus the safety, of parenteral iron preparations are directly related to the molecular weight and the stability of the complex. High oral iron doses or rapid release of iron from intravenous iron preparations can saturate the iron transport system, resulting in oxidative stress with adverse clinical and subclinical consequences. Appropriate pharmacokinetics and pharmacodynamics analyses will greatly assist our understanding of the likely contribution of novel preparations to the management of anemia. PMID:24310424

Geisser, Peter; Burckhardt, Susanna

2011-01-01

210

IRON HOMEOSTATIS IN THE LUNG  

EPA Science Inventory

Iron is essential for many aspects of cellular function. However, it can also generate oxygen-based free radicals that result in injury to biological molecules. For this reason, iron acquisition and distribution are tightly regulated. Constant exposure to the atmosphere result...

211

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...

212

Clostridial Iron-Sulphur Proteins  

Microsoft Academic Search

Iron-sulfur proteins are ubiquitous catalysts of a wide range of biological reactions, and are particularly abundant in clostridia which lack the ability to synthesize hemes. The development of research on these metalloproteins has therefore been strongly associated with biochemical investigations of clostridial metabolism. Major breakthroughs in the field, from the first isolation of an iron-sulfur protein in 1962, to the

Jacques Meyer

213

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

214

Iron deficiency: the global perspective.  

PubMed

The prevelance of IDA in industrialized countries has declined in recent decades, but there has been little change in the worldwide prevalence. IDA is currently estimated to affect more than 500 million people. Recent studies have indicated that anemia per se, the most common manifestation of iron deficiency, is less important from a public health standpoint than liabilities associated with tissue iron deficiency. The most important of the latter are an impairment in psychomotor development and cognitive function in infants and preschoolers, a deficit in work performance in adults, and an increase in the frequency of low birth weight, prematurity, and perinatal mortality in pregnancy. There have been several recent advances in combatting nutritional iron deficiency. One of the major problems has been in distinguishing iron deficiency from other causes of anemia seen epidemiologically such as malaria, HIV infection, chronic inflammation, hemoglobinopathies, and protein energy malnutrition. When combined with serum ferritin and hemoglobin determinations, the serum transferrin receptor assay is a valuable addition in epidemiologic surveys because it provides a quantitative measure of functional iron deficiency and it distinguishes true IDA from the anemia of chronic disease. The most difficult challenge is to develop effective methods of supplying iron to large segments of a population. Supplementation with iron tablets is suitable for only brief periods of need such as during pregnancy. The poor compliance with existing supplementation programs is believed to be due mainly to the gastrointestinal side effects of oral iron which can be eliminated by the use of a gastric delivery system. The most effective long-term strategy is to increase the intake of bioavailable iron in the diet. The customary approach has been to fortify a food staple such as wheat, rice, sugar, or salt, and thereby increase the iron intake of the entire population. However, because of concerns about the risk of cancer and heart disease in individuals with high iron stores, there is an increasing reluctance to supply iron to individuals who do not require it. A more effective strategy is to fortify food vehicles that are targeted to segments of the population at greatest risk of iron deficiency such as infants and school children. Because of the strong inhibitory properties of diets in regions of the world where iron deficiency is most prevalent, the use of NaFeEDTA has important advantages for food fortification. PMID:7887226

Cook, J D; Skikne, B S; Baynes, R D

1994-01-01

215

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

216

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

217

Screening test for iron overload.  

PubMed

It is presently estimated that 2-3/10(3) people living in the United States are homozygous for the iron-loading gene and are thereby susceptible to severe iron overload. The complications of this disorder can be prevented if recognized in the asymptomatic precirrhotic stage. We have developed a simple, inexpensive screening method for its early laboratory detection based on the fact that one of the earliest laboratory manifestations of hemochromatosis is a reduction in unsaturated iron-binding capacity. The sequential addition of a small measured quantity of saturating iron and bathophenanthroline disulfonate will result in color with highly saturated but not with normal sera. This screening test almost completely differentiated between 40 normal individuals and 40 patients with iron overload (as defined by a transferrin saturation greater than 55%). The test provides a cost-effective method for screening large segments of the population to detect this genetic disorder. PMID:3673932

Skikne, B S; Cook, J D

1987-11-01

218

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

219

Iron: the new advances in therapy.  

PubMed

Conditions known as iron-deficiency syndromes are very common in various patient populations, and they can adversely affect the outcomes of the patients, in addition to increasing their risk of getting transfused. Iron-deficiency syndromes include absolute iron deficiency (absence of storage iron), functional iron deficiency (when demand for iron exceeds the supply in face of intense stimulation erythropoiesis) and iron sequestration (in which existing storage iron becomes unavailable); these conditions often co-exist in hospitalised patients, making the diagnosis and management more difficult. Nonetheless, iron is emerging as a safe and effective therapy in patients suffering from these conditions. Notably, several intravenous iron formulations are available and they can be used safely and effectively to restore the body iron levels (possibly even in a single treatment episode). Data from ongoing clinical trials are expected to further establish the role of these products in treatment of patients with anaemia. PMID:23590922

Auerbach, Michael; Goodnough, Lawrence Tim; Shander, Aryeh

2013-03-01

220

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

221

Pituitary iron and volume predict hypogonadism in transfusional iron overload.  

PubMed

Hypogonadism is the most common morbidity in patients with transfusion-dependent anemias such as thalassemia major. We used magnetic resonance imaging (MRI) to measure pituitary R2 (iron) and volume to determine at what age these patients develop pituitary iron overload and volume loss. We recruited 56 patients (47 with thalassemia major, five with chronically transfused thalassemia intermedia and four with Blackfan-Diamond syndrome) to have pituitary MRIs to measure pituitary R2 and volume. Hypogonadism was defined clinically based on the timing of secondary sexual characteristics or the need for sex hormone replacement therapy. Patients with transfusional iron overload begin to develop pituitary iron overload in the first decade of life; however, clinically significant volume loss was not observed until the second decade of life. Severe pituitary iron deposition (Z > 5) and volume loss (Z < -2.5) were independently predictive of hypogonadism. Pituitary R2 correlated significantly with serum ferritin as well as liver, pancreatic, and cardiac iron deposition by MRI. Log pancreas R2* was the best single predictor for pituitary iron, with an area under the receiving operator characteristic curve of 0.88, but log cardiac R2* and ferritin were retained on multivariate regression with a combined r(2) of 0.71. Pituitary iron overload and volume loss were independently predictive of hypogonadism. Many patients with moderate-to-severe pituitary iron overload retained normal gland volume and function, representing a potential therapeutic window. The subset of hypogonadal patients having preserved gland volumes may also explain improvements in pituitary function observed following intensive chelation therapy. PMID:22213195

Noetzli, Leila J; Panigrahy, Ashok; Mittelman, Steven D; Hyderi, Aleya; Dongelyan, Ani; Coates, Thomas D; Wood, John C

2012-02-01

222

SNAPing Coronal Iron  

NASA Astrophysics Data System (ADS)

This is a Snapshot Survey to explore two forbidden lines of highly ionized iron in late-type coronal sources. Fe XII 1349 {T 2 MK} and Fe XXI 1354 {T 10 MK} - well known to Solar Physics - have been detected in about a dozen cool stars, mainly with HST/STIS. The UV coronal forbidden lines are important because they can be observed with velocity resolution of better than 15 km/s, whereas even the state-of-the-art X-ray spectrometers on Chandra can manage only 300 km/s in the kilovolt band where lines of highly ionized iron more commonly are found. The kinematic properties of hot coronal plasmas, which are of great interest to theorists and modelers, thus only are accessible in the UV at present. The bad news is that the UV coronal forbidden lines are faint, and were captured only in very deep observations with STIS. The good news is that 3rd-generation Cosmic Origins Spectrograph, slated for installation in HST by SM4, in a mere 25 minute exposure with its G130M mode can duplicate the sensitivity of a landmark 25-orbit STIS E140M observation of AD Leo, easily the deepest such exposure of a late-type star so far. Our goal is to build up understanding of the properties of Fe XII and Fe XXI in additional objects beyond the current limited sample: how the lineshapes depend on activity, whether large scale velocity shifts can be detected, and whether the dynamical content of the lines can be inverted to map the spatial morphology of the stellar corona {as in "Doppler Imaging''}. In other words, we want to bring to bear in the coronal venue all the powerful tricks of spectroscopic remote sensing, well in advance of the time that this will be possible exploiting the corona's native X-ray radiation. The 1290-1430 band captured by side A of G130M also contains a wide range of key plasma diagnostics that form at temperatures from below 10,000 K {neutral lines of CNO}, to above 200,000 K {semi-permitted O V 1371}, including the important bright multiplets of C II at 1335 and Si IV at 1400; yielding a diagnostic gold mine for the subcoronal atmosphere. Because of the broad value of the SNAP spectra, beyond the coronal iron project, we waive the normal proprietary rights.

Ayres, Thomas

2009-07-01

223

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

224

Iron-induced thrombocytopenia in severe iron-deficiency anemia.  

PubMed

Iron deficiency anemia (IDA) is commonly associated with reactive thrombocytosis, but thrombocytopenia is relatively uncommon and generally associated with more severe IDA. Even more rarely described has been thrombocytopenia following iron replacement therapy to treat IDA, and the underlying mechanism remains unclear. The authors present the case of a patient with severe IDA, who developed thrombocytopenia after the initiation of iron therapy. An analysis is made of all the previous reports of similar cases, to compare and start on the path of understanding this rare entity. PMID:25673365

Cunha, Vitória; Ferreira, Melanie; Barosa, Rita; Fonseca, Ana Glória; Delerue, Francisca; Carvalho, Carla

2015-04-01

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

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

227

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

228

Metallurgy Beyond Iron  

NASA Astrophysics Data System (ADS)

Metallurgy is one of the oldest sciences. Its history can be traced back to 6000 BCE with the discovery of Gold, and each new discovery - Copper, Silver, Lead, Tin, Iron and Mercury - marked the beginning of a new era of civilization. Currently there are 86 known metals, but until the end of the 17th century, only 12 of these were known. Steel (Fe-C alloy) was discovered in the 11th century BCE; however, it took until 1709 CE before we mastered the smelting of pig-iron by using coke instead of charcoal and started the industrial revolution. The metallurgy of nowadays is mainly about discovering better materials with superior properties to fulfil the increasing demand of the global market. Promising are the Glassy Metals or Bulk Metallic Glasses (BMGs) - discovered at first in the late 50s at the California Institute of Technology - which are several times stronger than the best industrial steels and 10-times springier. The unusual structure that lacks crystalline grains makes BMGs so promising. They have a liquid-like structure that means they melt at lower temperatures, can be moulded nearly as easily as plastics, and can be shaped into features just 10 nm across. The best BMG formers are based on Zr, Pd, Pt, Ca, Au and, recently discovered, also Fe. They have typically three to five components with large atomic size mismatch and a composition close to a deep eutectic. Packing in such liquids is very dense, with a low content of free volume, resulting in viscosities that are several orders of magnitude higher than in pure metal melts.

Gallino, Isabella; Busch, Ralf

2009-08-01

229

Iron homeostasis in breast cancer.  

PubMed

Iron is an essential element and a critical component of molecules involved in energy production, cell cycle and intermediate metabolism. However, the same characteristic chemistry that makes it so biologically versatile may lead to iron-associated toxicity as a consequence of increased oxidative stress. The fact that free iron accumulates with age and generates ROS led to the hypothesis that it could be involved in the etiogenesis of several chronic diseases. Iron has been consistently linked to carcinogenesis, either through persistent failure in the redox balance or due to its critical role in cellular proliferation. Several reports have given evidence that alterations in the import, export and storage of cellular iron may contribute to breast cancer development, behavior and recurrence. In this review, we summarize the basic mechanisms of systemic and cellular iron regulation and highlight the findings that link their deregulation with breast cancer. To conclude, progresses in iron chelation therapy in breast cancer, as a tool to fight chemotherapy resistance, are also reviewed. PMID:24486738

Marques, Oriana; da Silva, Berta Martins; Porto, Graça; Lopes, Carlos

2014-05-28

230

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

231

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

232

Recovery of scrap iron metal value using biogenerated ferric iron.  

PubMed

The utility of employing biogenerated ferric iron as an oxidant for the recycling of scrap metal has been demonstrated using continuously growing cells of the extremophilic organism Acidithiobacillus ferrooxidans. A ferric iron rich (70 mol%) lixiviant resulting from bioreactor based growth of A. ferrooxidans readily solubilized target scrap metal with the resultant generation of a leachate containing elevated ferrous iron levels and solubilized copper previously resident in the scrap metal. Recovery of the copper value was easily accomplished via a cementation reaction and the clarified leachate containing a replenished level of ferrous iron as growth substrate was shown to support the growth of A. ferrooxidans and be fully recyclable. The described process for scrap metal recycling and copper recovery was shown to be efficient and economically attractive. Additionally, the utility of employing the E(h) of the growth medium as a means for monitoring fluctuations in cell density in cultures of A. ferrooxidans is demonstrated. PMID:16440341

Ballor, Nicholas R; Nesbitt, Carl C; Lueking, Donald R

2006-04-20

233

Magnetic study of iron sorbitol  

NASA Astrophysics Data System (ADS)

A magnetic study of iron sorbitol, an iron-containing drug to treat the iron deficiency anemia is presented. Transmission electron microscopy reveals that the system contains nanometric particles with an average diameter of 3 nm whose composition is close to two-line ferrihydrite. The characterisation by magnetisation and AC susceptibility measurements indicates superparamagnetic behaviour with progressive magnetic blocking starting at 8 K. The quantitative analysis of the magnetic results indicates that the system consists of an assembly of very small magnetic moments, presumably originated by spin uncompensation of the antiferromagnetic nanoparticles, with Arrhenius type magnetic dynamics.

Lázaro, F. J.; Larrea, A.; Abadía, A. R.; Romero, M. S.

2002-09-01

234

ELECTRICAL IMAGING OF PERMEABLE REACTIVE BARRIER (PRB) INTEGRITY  

Microsoft Academic Search

The permeable reactive barrier (PRB) is a promising in-situ technology for treatment of hydrocarbon contaminated groundwater. A PRB is typically composed of granular iron, which degrades chlorinated organics into potentially nontoxic dehalogenated organic compounds and inorganic chloride. Geophysical methods may assist assessment of in-situ barrier integrity and evaluate long term barrier performance. The highly conductive granular iron makes the PRB

Lee Slater; Joe Baker; Andrew Binley; England Danney Glaser

235

Gaseous reduction of iron oxides: Part III. Reduction-oxidation of porous and dense iron oxides and iron  

Microsoft Academic Search

The internal reduction of high-grade granular hematite ore in hydrogen and carbon monoxide, and also the internal oxidation\\u000a of porous iron granules in CO2-CO mixtures have been investigated. To assist the interpretation of the rate data for porous iron and iron oxides, rate measurements\\u000a have been made also with dense wustite, previously grown on iron by oxidation. The iron formed

E. T. Turkdogan; J. V. Vinters

1972-01-01

236

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...

237

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

238

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

239

Soldering iron temperature is automatically reduced  

NASA Technical Reports Server (NTRS)

Hinged cradle-microswitch arrangement maintains a soldering iron at less than peak temperature when not in use. The microswitch introduces a voltage reducing element into the soldering iron power circuit when the iron is placed on the cradle. The iron, when removed from the cradle, returns to operating temperature in 15 to 30 seconds.

Lum, J. Y.

1966-01-01

240

Compressed iron powder core for electric motors  

Microsoft Academic Search

The magnetic properties of compressed powder cores made of iron powder with high compressibility were investigated with the goal of making them practical in electric motors. An electrolytic iron powder and an atomized iron powder with a finely powdered resin were compacted under a pressure of 6 tons\\/cm2. The influence of iron particle size on magnetic properties was more marked

K. Fukui; I. Watanabe; M. Morita

1972-01-01

241

Food iron absorption in idiopathic hemochromatosis.  

PubMed

The relationship between iron status and food iron absorption was evaluated in 75 normal volunteers, 15 patients with idiopathic hemochromatosis, and 22 heterozygotes by using double extrinsic radioiron tags to label independently the nonheme and heme iron components of a hamburger meal. In normal subjects, absorption from each of these pools was inversely correlated with storage iron, as measured by the serum ferritin concentration. In patients with hemochromatosis, absorption of both forms of iron was far greater than would be predicted from the relationship between absorption and serum ferritin observed in normal volunteers. Nevertheless, there was still a modest but statistically significant reduction in absorption of nonheme iron with increasing serum ferritin. This relationship could not be demonstrated in the case of heme iron absorption. In heterozygotes, nonheme iron absorption from a hamburger meal containing no supplementary iron did not differ significantly from that observed in normal volunteers. However, when this meal was both modified to promote bioavailability and supplemented with iron, absorption of nonheme iron was significantly elevated. These studies confirm the presence of excessive nonheme iron absorption even from unfortified meals in patients with idiopathic hemochromatosis and suggest in addition that they are particularly susceptible to iron loading from diets containing a high proportion of heme iron. Impaired regulation of nonheme iron absorption was also observed in heterozygous individuals, but a statistically significant abnormality was demonstrable only when the test meal contained a large highly bioavailable iron supplement. PMID:2804357

Lynch, S R; Skikne, B S; Cook, J D

1989-11-01

242

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...

243

Iron acquisition by Neisseria meningitidis in vitro.  

PubMed Central

Assays employing iron-limited solid and liquid, defined and complex media were devised to test the iron requirements of Neisseria meningitidis. A variety of tests yielded no evidence for the secretion of a soluble iron-binding substance (siderophore) by the meningococci. The meningococci were unable to use iron bound to some common hydroxamate- and catechol-type siderophores or even compete with them for iron in the growth medium. A total of 20 strains of meningococci, differing widely in their virulence for mice, were similar in ability to acquire iron from a variety of iron-containing substances; the iron in such compounds as hog gastric mucin, citrate, hemoglobin, and myoglobin was easily acquired, whereas the iron in compounds such as ferrioxamine B, ferrichrome,ferritin, Imferon, cytochrome c, FePO4, and [Fe(OH)3]n was not readily available. No correlation was noted between the ability of particular strains to obtain iron from compounds and virulence in mice. Iron complexed or chelated with a number of metabolic organic acids, polyphosphates, and several synthetic polycarboxylic acids was readily available to all strains, even though some of the compounds used had high effective binding constants for iron and all were in 3- or 10-fold molar excess over the iron present. The addition of some of these iron-complexing substances (e.g., citrate and pyrophosphate) in iron-free form made many biologically important iron compounds that are normally inaccessible to the meningococci readily available. Images Fig. 1 PMID:6445876

Archibald, F S; DeVoe, I W

1980-01-01

244

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

245

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192.373 Transportation...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron...

2010-10-01

246

Iron deficiency anemia in heart failure.  

PubMed

Anemia and iron deficiency are quite prevalent in patients with heart failure (HF) and may overlap. Both anemia and iron deficiency are associated with worse symptoms and adverse clinical outcomes. In the past few years, there has been an enormous interest in the subject of iron deficiency and its management in patients with HF. In this review, the etiology and relevance of iron deficiency, iron metabolism in the setting of HF, studies on iron supplementation in patients with HF and potential cardiovascular effects of subclinical iron overload are discussed. PMID:22948485

Arora, Natasha P; Ghali, Jalal K

2013-07-01

247

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

248

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

249

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

250

Myelin Breakdown and Iron Changes in Huntington’s Disease: Pathogenesis and Treatment Implications  

Microsoft Academic Search

Background  \\u000a Postmortem and in vivo imaging data support the hypothesis that premature myelin breakdown and subsequent homeostatic remyelination\\u000a attempts with increased oligodendrocyte and iron levels may contribute to Huntington’s Disease (HD) pathogenesis and the symmetrical\\u000a progress of neuronal loss from earlier-myelinating striatum to later-myelinating regions. A unique combination of in vivo\\u000a tissue integrity and iron level assessments was used to

George Bartzokis; Po H. Lu; Todd A. Tishler; Sophia M. Fong; Bolanle Oluwadara; J. Paul Finn; Danny Huang; Yvette Bordelon; Jim Mintz; Susan Perlman

2007-01-01

251

Iron and Women’s Health  

Microsoft Academic Search

\\u000a • Iron is an essential mineral required for transport of oxygen throughout the body and for the optimal development of the\\u000a fetal brain.\\u000a \\u000a \\u000a • Iron-intake requirements are regulated by the size of body iron stores. Lifestyle factors that often influence iron status\\u000a in women include amount of iron consumed, use of oral contraceptives, use of hormone replacement therapy, vegetarianism, intestinal

Adrianne Bendich; Ronit Zilberboim

252

ANEMIA OF DISORDERED IRON METABOLISM AND HEME  

E-print Network

Total Iron Concentration 40-50 mg Hemoglobin = 0.5 mg iron/ml blood Transferrin = Transport Protein of Individual TRANSPORT Transferrin ­ Plasma Transport Protein each gm will bind 1.4 mg of Iron TIBC = 250-450 g iron/dL plasma Serum Iron = 65-180 g/dL male and 50-180 g/dL female Transferrin Receptor = 2

253

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

254

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.

Not Available

1982-03-06

255

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. 2 figs.

Welbon, W.W.

1983-11-08

256

Iron and Steel Phosphate Rock  

E-print Network

Phosphate Rock Platinum Potash Pumice Quartz Crystal Rare Earths Rhenium Rubidium Salt Sand and Gravel Platinum Tellurium Bromine Indium Potash Thallium Cadmium Iodine Pumice Thorium Cement Iron Ore Quartz

Torgersen, Christian

257

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 ...

258

Luminescent iron clusters in solution.  

PubMed

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 [Fe??(TOPO)?(H?O)?](+), [Fe??(TOPO)?(H?O)](+) and [Fe?(TOPO)(H?O)?](+) by mass spectrometry. This study lays the groundwork for exploiting unique properties of soluble iron clusters. PMID:24356936

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

2014-01-01

259

Iron for restless legs syndrome  

PubMed Central

Background Restless legs syndrome (RLS) is a common neurologic syndrome and is associated with iron deficiency in many patients. It is unclear whether iron therapy is effective treatment for RLS. Objectives The objective of this review was to assess the effects of iron supplementation (oral or intravenous) for patients with RLS. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Jan 1995 to April 2011); EMBASE (Jan 1995 to April 2011); PsycINFO (Jan 1995 to April 2011); and CINAHL (Jan 1995 to April 2011). Corresponding authors of included trials and additional members of the International Restless Legs Syndrome Study Group were contacted to locate additional published or unpublished trials. Selection criteria Controlled trials comparing any formulation of iron with placebo, other medications, or no treatment in adults diagnosed with RLS according to expert clinical interview or explicit diagnostic criteria. Data collection and analysis Two review authors extracted data and at least two authors assessed trial quality. We contacted trial authors for missing data. Main results Six studies (192 total subjects) were identified and included in this analysis. The quality of trials was variable. Our primary outcome was restlessness or uncomfortable leg sensations, which was quantified using the IRLS severity scale in four trials and another RLS symptom scale in a fifth trial. Combining data from the four trials using the IRLS severity scale, there was no clear benefit from iron therapy (mean difference in IRLS severity scores of -3.79, 95% CI: -7.68 to 0.10, p = 0.06). However, the fifth trial did find iron therapy to be beneficial (median decrease of 3 points in the iron group and no change in the placebo group on a 10 point scale of RLS symptoms, p = 0.01). Quality of life was improved in the iron group relative to placebo in some studies but not others. Changes in periodic limb movements were not different between groups (measured in two studies). Objective sleep quality, subjective sleep quality and daytime functioning were not different between treatment groups in the studies that assessed them. The single study of subjects with end stage renal disease did show a benefit of therapy. Most trials did not require subjects to have co-morbid iron deficiency and several excluded patients with severe anemia. The single study that was limited to iron deficient subjects did not show clear benefit of iron supplementation on RLS symptoms. There was no clear superiority of oral or intravenous delivery of iron. Iron therapy did not result in significantly more side effects than placebo (RR 1.39, 95% CI 0.85 to 2.27). Authors' conclusions There is insufficient evidence to determine whether iron therapy is beneficial for the treatment of RLS. Further research to determine whether some or all types of RLS patients may benefit from iron therapy, as well as the best route of iron administration, is needed. PMID:22592724

Trotti, Lynn M; Bhadriraju, Srinivas; Becker, Lorne A

2014-01-01

260

An iron K-edge XANES study of iron and iron oxides for the cathodic disbonding of fusion bonded epoxy in alkaline aqueous solution  

SciTech Connect

Iron K-edge X-ray absorption near-edge structure (XANES) of laboratory-scale model oxide systems was studied to provide insights about the mechanism of cathodic disbonding of fusion bonded epoxy (FBE) from underground steel pipelines. Two model systems were studied: (1) thin film iron (500 {angstrom} thick) thermally oxidized at 240 C; and (2) thin film iron coated with FBE and cathodically disbonded. The thin film iron exhibited a trend of decreasing metallic character with increasing thermal oxidation times. After 122 h of oxidation, the oxidic character became predominant. The oxide appeared to abe a mixture of Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}. The XANES data for the region under the cathodically disbonded FBE coating exhibited more metallic character than the region that maintained the bond integrity. Under the cathodic disbonding conditions of the present study ({minus}1.5 V-SCE in 1M KOH aqueous solution), the XANES results, although preliminary, support the oxide reduction and/or oxide dissolution mechanisms of disbonding.

Song, I.; Payer, J.H. [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering; Antonio, M.R. [Argonne National Lab., IL (United States). Chemistry Division

1995-07-01

261

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

262

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

263

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

264

The quantitative assessment of body iron.  

PubMed

Current initiatives to reduce the high prevalence of nutritional iron deficiency have highlighted the need for reliable epidemiologic methods to assess iron status. The present report describes a method for estimating body iron based on the ratio of the serum transferrin receptor to serum ferritin. Analysis showed a single normal distribution of body iron stores in US men aged 20 to 65 years (mean +/- 1 SD, 9.82 +/- 2.82 mg/kg). A single normal distribution was also observed in pregnant Jamaican women (mean +/- 1 SD, 0.09 +/- 4.48 mg/kg). Distribution analysis in US women aged 20 to 45 years indicated 2 populations; 93% of women had body iron stores averaging 5.5 +/- 3.35 mg/kg (mean +/- 1 SD), whereas the remaining 7% of women had a mean tissue iron deficit of 3.87 +/- 3.23 mg/kg. Calculations of body iron in trials of iron supplementation in Jamaica and iron fortification in Vietnam demonstrated that the method can be used to calculate absorption of the added iron. Quantitative estimates of body iron greatly enhance the evaluation of iron status and the sensitivity of iron intervention trials in populations in which inflammation is uncommon or has been excluded by laboratory screening. The method is useful clinically for monitoring iron status in those who are highly susceptible to iron deficiency. PMID:12521995

Cook, James D; Flowers, Carol H; Skikne, Barry S

2003-05-01

265

Ferritin excretion and iron balance in humans.  

PubMed

Under normal circumstances, most of the lumenal iron taken into the intestinal mucosal cell is stored within the cell as ferritin and subsequently is lost in the faeces when the cell exfoliates at the end of its lifespan. To evaluate whether faecal iron proteins reflect mucosal cell iron as well as whole body iron and to examine further the kinetics of gastrointestinal iron transport, faecal H-rich and L-rich ferritin were measured in normal subjects and patients with iron deficiency and genetic haemochromatosis. In normal and iron-deficient subjects, the concentration of L-rich but not H-rich faecal ferritin correlated closely with body iron status. In genetic haemochromatosis, the faecal L-rich and H-rich ferritin concentrations were lower than expected for their body iron status. The administration of oral iron to normal subjects led to a rise in L-rich ferritin. Administration of oral or parenteral iron to patients with iron deficiency led to a prompt rise in both forms of faecal ferritin, although the relative increase of L-rich ferritin was greater than that of H-rich ferritin with oral iron administration. Faecal ferritin correlated closely with iron stores in normals and patients with iron deficiency but faecal ferritin levels were lower than expected in genetic haemochromatosis, similar to that previously noted in the duodenal mucosal cells of these patients. PMID:7647009

Skikne, B S; Whittaker, P; Cooke, A; Cook, J D

1995-07-01

266

Two transcription factors are necessary for iron homeostasis in a salt-dwelling archaeon  

PubMed Central

Because iron toxicity and deficiency are equally life threatening, maintaining intracellular iron levels within a narrow optimal range is critical for nearly all known organisms. However, regulatory mechanisms that establish homeostasis are not well understood in organisms that dwell in environments at the extremes of pH, temperature, and salinity. Under conditions of limited iron, the extremophile Halobacterium salinarum, a salt-loving archaeon, mounts a specific response to scavenge iron for growth. We have identified and characterized the role of two transcription factors (TFs), Idr1 and Idr2, in regulating this important response. An integrated systems analysis of TF knockout gene expression profiles and genome-wide binding locations in the presence and absence of iron has revealed that these TFs operate collaboratively to maintain iron homeostasis. In the presence of iron, Idr1 and Idr2 bind near each other at 24 loci in the genome, where they are both required to repress some genes. By contrast, Idr1 and Idr2 are both necessary to activate other genes in a putative a feed forward loop. Even at loci bound independently, the two TFs target different genes with similar functions in iron homeostasis. We discuss conserved and unique features of the Idr1–Idr2 system in the context of similar systems in organisms from other domains of life. PMID:21109526

Schmid, Amy K.; Pan, Min; Sharma, Kriti; Baliga, Nitin S.

2011-01-01

267

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

268

Thermal Infrared Emission Measurements of Iron Sulfate and Phosphate Samples for Application to Mars  

NASA Astrophysics Data System (ADS)

Iron sulfate and phosphate minerals have been identified on Mars through the integration of data from multiple instruments on the Mars Exploration Rovers (MERs). In order to more thoroughly study the MER Mini-Thermal Emission Spectrometer (Mini-TES) and Mars Global Surveyor TES data sets, suites of iron sulfate minerals and phosphate minerals have been collected; the chemistry of each sample has been verified by X-ray diffraction analysis and thermal emission spectra have been obtained. Obtaining pure, well-characterized samples has been arduous, but the spectra to be presented were acquired of chemically verified samples. Iron sulfate and phosphate minerals consist of XO4 tetrahedra (where X is S and P, respectively) polymerized with MO6 polyhedra (where M is a metal cation) in various configurations. These mid-infrared iron sulfate and phosphate spectra are dominated by features associated with the X-O vibrations of the SO4 and PO4 tetrahedra, similar to non-iron-bearing sulfates. Many of the iron sulfate chemistries studied include bound water (OH and/or H2O), hence their iron sulfate spectra exhibit a water bending feature that lies between approximately 1700 and 1630 cm^-1. Typically, the phosphate spectra are less hydrous. Within their mineral classes, iron sulfate and phosphate spectra exhibit similarities, which generally align by Strunz groups. These well-characterized spectra will enable further analysis of spectral data sets from Mars.

Lane, M. D.; Bishop, J. L.; Dyar, M. D.

2012-12-01

269

Fur controls iron homeostasis and oxidative stress defense in the oligotrophic alpha-proteobacterium Caulobacter crescentus  

PubMed Central

In most bacteria, the ferric uptake regulator (Fur) is a global regulator that controls iron homeostasis and other cellular processes, such as oxidative stress defense. In this work, we apply a combination of bioinformatics, in vitro and in vivo assays to identify the Caulobacter crescentus Fur regulon. A C. crescentus fur deletion mutant showed a slow growth phenotype, and was hypersensitive to H2O2 and organic peroxide. Using a position weight matrix approach, several predicted Fur-binding sites were detected in the genome of C. crescentus, located in regulatory regions of genes not only involved in iron uptake and usage but also in other functions. Selected Fur-binding sites were validated using electrophoretic mobility shift assay and DNAse I footprinting analysis. Gene expression assays revealed that genes involved in iron uptake were repressed by iron-Fur and induced under conditions of iron limitation, whereas genes encoding iron-using proteins were activated by Fur under conditions of iron sufficiency. Furthermore, several genes that are regulated via small RNAs in other bacteria were found to be directly regulated by Fur in C. crescentus. In conclusion, Fur functions as an activator and as a repressor, integrating iron metabolism and oxidative stress response in C. crescentus. PMID:19520766

da Silva Neto, José F.; Braz, Vânia S.; Italiani, Valéria C. S.; Marques, Marilis V.

2009-01-01

270

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

271

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

272

Host iron status and iron supplementation mediate susceptibility to erythrocytic stage Plasmodium falciparum.  

PubMed

Iron deficiency and malaria have similar global distributions, and frequently co-exist in pregnant women and young children. Where both conditions are prevalent, iron supplementation is complicated by observations that iron deficiency anaemia protects against falciparum malaria, and that iron supplements increase susceptibility to clinically significant malaria, but the mechanisms remain obscure. Here, using an in vitro parasite culture system with erythrocytes from iron-deficient and replete human donors, we demonstrate that Plasmodium falciparum infects iron-deficient erythrocytes less efficiently. In addition, owing to merozoite preference for young erythrocytes, iron supplementation of iron-deficient individuals reverses the protective effects of iron deficiency. Our results provide experimental validation of field observations reporting protective effects of iron deficiency and harmful effects of iron administration on human malaria susceptibility. Because recovery from anaemia requires transient reticulocytosis, our findings imply that in malarious regions iron supplementation should be accompanied by effective measures to prevent falciparum malaria. PMID:25059846

Clark, Martha A; Goheen, Morgan M; Fulford, Anthony; Prentice, Andrew M; Elnagheeb, Marwa A; Patel, Jaymin; Fisher, Nancy; Taylor, Steve M; Kasthuri, Raj S; Cerami, Carla

2014-01-01

273

Explorations of iron-iron hydrogenase active site models by experiment and theory  

E-print Network

This dissertation describes computational and experimental studies of synthetic complexes that model the active site of the iron-iron hydrogenase [FeFe]H 2ase enzyme. Simple dinuclear iron dithiolate complexes act as functional models of the ironiron...

Tye, Jesse Wayne

2009-05-15

274

Host iron status and iron supplementation mediate susceptibility to erythrocytic stage Plasmodium falciparum  

PubMed Central

Iron deficiency and malaria have similar global distributions, and frequently co-exist in pregnant women and young children. Where both conditions are prevalent, iron supplementation is complicated by observations that iron deficiency anaemia protects against falciparum malaria, and that iron supplements increase susceptibility to clinically significant malaria, but the mechanisms remain obscure. Here, using an in vitro parasite culture system with erythrocytes from iron-deficient and replete human donors, we demonstrate that Plasmodium falciparum infects iron-deficient erythrocytes less efficiently. In addition, owing to merozoite preference for young erythrocytes, iron supplementation of iron-deficient individuals reverses the protective effects of iron deficiency. Our results provide experimental validation of field observations reporting protective effects of iron deficiency and harmful effects of iron administration on human malaria susceptibility. Because recovery from anaemia requires transient reticulocytosis, our findings imply that in malarious regions iron supplementation should be accompanied by effective measures to prevent falciparum malaria. PMID:25059846

Clark, Martha A.; Goheen, Morgan M.; Fulford, Anthony; Prentice, Andrew M.; Elnagheeb, Marwa A.; Patel, Jaymin; Fisher, Nancy; Taylor, Steve M.; Kasthuri, Raj S.; Cerami, Carla

2014-01-01

275

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

276

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

277

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

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

Retinal iron homeostasis in health and disease  

PubMed Central

Iron is essential for life, but excess iron can be toxic. As a potent free radical creator, iron generates hydroxyl radicals leading to significant oxidative stress. Since iron is not excreted from the body, it accumulates with age in tissues, including the retina, predisposing to age-related oxidative insult. Both hereditary and acquired retinal diseases are associated with increased iron levels. For example, retinal degenerations have been found in hereditary iron overload disorders, like aceruloplasminemia, Friedreich's ataxia, and pantothenate kinase-associated neurodegeneration. Similarly, mice with targeted mutation of the iron exporter ceruloplasmin and its homolog hephaestin showed age-related retinal iron accumulation and retinal degeneration with features resembling human age-related macular degeneration (AMD). Post mortem AMD eyes have increased levels of iron in retina compared to age-matched healthy donors. Iron accumulation in AMD is likely to result, in part, from inflammation, hypoxia, and oxidative stress, all of which can cause iron dysregulation. Fortunately, it has been demonstrated by in vitro and in vivo studies that iron in the retinal pigment epithelium (RPE) and retina is chelatable. Iron chelation protects photoreceptors and retinal pigment epithelial cells (RPE) in a variety of mouse models. This has therapeutic potential for diminishing iron-induced oxidative damage to prevent or treat AMD. PMID:23825457

Song, Delu; Dunaief, Joshua L.

2013-01-01

280

Regulation of Iron Metabolism by Pyrococcus furiosus  

PubMed Central

Iron is an essential element for the hyperthermophilic archaeon Pyrococcus furiosus, and many of its iron-containing enzymes have been characterized. How iron assimilation is regulated, however, is unknown. The genome sequence contains genes encoding two putative iron-responsive transcription factors, DtxR and Fur. Global transcriptional profiles of the dtxR deletion mutant (?DTXR) and the parent strain under iron-sufficient and iron-limited conditions indicated that DtxR represses the expression of the genes encoding two putative iron transporters, Ftr1 and FeoAB, under iron-sufficient conditions. Under iron limitation, DtxR represses expression of the gene encoding the iron-containing enzyme aldehyde ferredoxin oxidoreductase and a putative ABC-type transporter. Analysis of the dtxR gene sequence indicated an incorrectly predicted translation start site, and the corrected full-length DtxR protein, in contrast to the truncated version, specifically bound to the promoters of ftr1 and feoAB, confirming its role as a transcription regulator. Expression of the gene encoding Ftr1 was dramatically upregulated by iron limitation, but no phenotype was observed for the ?FTR1 deletion mutant under iron-limited conditions. The intracellular iron concentrations of ?FTR1 and the parent strain were similar, suggesting that under the conditions tested, Ftr1 is not an essential iron transporter despite its response to iron. In contrast to DtxR, the Fur protein appears not to be a functional regulator in P. furiosus, since it did not bind to the promoters of any of the iron-regulated genes and the deletion mutant (?FUR) revealed no transcriptional responses to iron availability. DtxR is therefore the key iron-responsive transcriptional regulator in P. furiosus. PMID:23504018

Zhu, Yixuan; Kumar, Sunil; Menon, Angeli L.; Scott, Robert A.

2013-01-01

281

A Cascade of Iron-Containing Proteins Governs the Genetic Iron Starvation Response to Promote Iron Uptake and Inhibit Iron Storage in Fission Yeast  

PubMed Central

Iron is an essential cofactor, but it is also toxic at high levels. In Schizosaccharomyces pombe, the sensor glutaredoxin Grx4 guides the activity of the repressors Php4 and Fep1 to mediate a complex transcriptional response to iron deprivation: activation of Php4 and inactivation of Fep1 leads to inhibition of iron usage/storage, and to promotion of iron import, respectively. However, the molecular events ruling the activity of this double-branched pathway remained elusive. We show here that Grx4 incorporates a glutathione-containing iron-sulfur cluster, alone or forming a heterodimer with the BolA-like protein Fra2. Our genetic study demonstrates that Grx4-Fra2, but not Fep1 nor Php4, participates not only in iron starvation signaling but also in iron-related aerobic metabolism. Iron-containing Grx4 binds and inactivates the Php4 repressor; upon iron deprivation, the cluster in Grx4 is probably disassembled, the proteins dissociate, and Php4 accumulates at the nucleus and represses iron consumption genes. Fep1 is also an iron-containing protein, and the tightly bound iron is required for transcriptional repression. Our data suggest that the cluster-containing Grx4-Fra2 heterodimer constitutively binds to Fep1, and upon iron deprivation the disassembly of the iron cluster between Grx4 and Fra2 promotes reverse metal transfer from Fep1 to Grx4-Fra2, and de-repression of iron-import genes. Our genetic and biochemical study demonstrates that the glutaredoxin Grx4 independently governs the Php4 and Fep1 repressors through metal transfer. Whereas iron loss from Grx4 seems to be sufficient to release Php4 and allow its nuclear accumulation, total or partial disassembly of the Grx4-Fra2 cluster actively participates in iron-containing Fep1 activation by sequestering its iron and decreasing its interaction with promoters. PMID:25806539

Carmona, Mercè; Ayté, José; Hidalgo, Elena

2015-01-01

282

Fluorescent bacteria for colloidal iron biosensors  

NASA Astrophysics Data System (ADS)

This research was focused on the possibility of iron sensing by means of bacterial cultures. The effect of ferric and ferrous ions on Pseudomonas aeruginosa, which has the ability to uptake the environmental iron in the form of complex iron compositions named siderophores, characterized by luminescent features, was studied. The different sensitivity to the iron from oxide compounds in comparison to the iron from chlorides and sulfate was emphasized by means of fluorescence measurements. It could be stated that Pseudomonas aeruginosa, from human body specimens could be the biological component of an iron biosensor for ferrofluid traces reminiscent after the administration for medical purposes.

Poiata, A.; Vlahovici, Al.; Creanga, D. E.; Mocanasu, R. C.

2006-01-01

283

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

284

Iron in Parkinson's Disease Revisited  

NASA Astrophysics Data System (ADS)

Mössbauer studies of fresh frozen samples taken at autopsy from different parts of the human brain (globus pallidus (GP), substantia nigra (NS), and hippocamp (Hip)) showed a relatively high concentration of iron in these structures. Mössbauer data, biochemical results and transmission electron micrographs lead to the conclusion that in all above-mentioned structures iron is located mainly within ferritin. However, the Mössbauer doublets obtained from most brain samples at 90 K are slightly asymmetric. This asymmetry could be caused by the presence of a small amount of non-ferritin-like iron. Measurements at 4.1 K showed besides the six-line spectra characteristic for ferritin-like iron, an additional doublet with Mössbauer parameters different from ferritin. We found a slightly higher asymmetry and intensity of the 4.1 K doublet in Mössbauer spectra of Parkinsonian SN than in control SN. As Parkinson's disease is a progressive degeneration of nervous cells in SN and iron may be involved in this degeneration process, this may suggest that the factors evoking these phenomena are related to the pathogenesis of Parkinson's disease.

Galazka-Friedman, J.; Bauminger, E. R.; Friedman, A.

2002-06-01

285

?-Nitro Derivatives of Iron Corrolates  

PubMed Central

Two different methods for the regioselective nitration of different meso-triarylcorroles leading to the corresponding ?-substituted nitrocorrole iron complexes have been developed. A two-step procedure affords three Fe(III) nitrosyl products - the unsubstituted corrole, the 3-nitrocorrole and the 3,17-dinitrocorrole. In contrast, a one-pot synthetic approach drives the reaction almost exclusively to formation of the iron nitrosyl 3,17-dinitrocorrole. Electron-releasing substituents on the meso-aryl groups of the triarylcorroles induce higher yields and longer reaction times than what is observed for the synthesis of similar triarylcorroles with electron-withdrawing functionalities, and these results can be confidently attributed to the facile formation and stabilization of an intermediate iron corrole ?-cation radical. Electron-withdrawing substituents on the meso-aryl groups of triarylcorrole also seem to labilize the axial nitrosyl group which, in the case of the pentafluorophenylcorrole derivative, results in the direct formation of a disubstituted iron ?-oxo dimer complex. The influence of meso-aryl substituents on the progress and products of the nitration reaction was investigated. In addition, to elucidate the most important factors which influence the redox reactivity of these different iron nitrosyl complexes, selected compounds were examined by cyclic voltammetry and thin-layer UV-visible or FTIR spectroelectrochemistry in CH2Cl2. PMID:22394192

Nardis, Sara; Stefanelli, Manuela; Mohite, Pruthviraj; Pomarico, Giuseppe; Tortora, Luca; Manowong, Machima; Chen, Ping; Fronczek, Frank R.; McCandless, Gregory T.

2012-01-01

286

Graphite Formation in Cast Iron  

NASA Technical Reports Server (NTRS)

In the first phase of the project it was proven that by changing the ratio between the thermal gradient and the growth rate for commercial cast iron samples solidifying in a Bridgman type furnace, it is possible to produce all types of graphite structures, from flake to spheroidal, and all types of matrices, from ferritic to white at a certain given level of cerium. KC-135 flight experiments have shown that in a low-gravity environment, no flotation occurs even in spheroidal graphite cast irons with carbon equivalent as high as 5%, while extensive graphite flotation occurred in both flake and spheroidal graphite cast irons, in high carbon samples solidified in a high gravity environment. This opens the way for production of iron-carbon composite materials, with high carbon content (e.g., 10%) in a low gravity environment. By using KC-135 flights, the influence of some basic elements on the solidification of cast iron will be studied. The mechanism of flake to spheroidal graphite transition will be studied, by using quenching experiments at both low and one gravity for different G/R ratios.

Stefanescu, D. M.

1985-01-01

287

Influence of calcium depletion on iron-binding properties of milk.  

PubMed

We investigated the effects of calcium depletion on the binding of iron in milk. A weakly acidic cation-exchange resin was used to remove 3 different levels (18-22, 50-55, and 68-72%) of calcium from milk. Five levels of iron (5, 10, 15, 20, and 25 mM) were added to each of these calcium-depleted milks (CDM) and the resultant milks were analyzed for particle size, microstructure, and the distribution of protein and minerals between the colloidal and soluble phases. The depletion of calcium affected the distribution of protein and minerals in normal milk. Iron added to normal milk and low-CDM (~20% calcium depletion) bound mainly to the colloidal phase (material sedimented at 100,000×g for 1 h at 20°C), with little effect on the integrity of the casein micelles. Depletion of ~70% of the calcium from milk resulted in almost complete disintegration of the casein micelles, as indicated by all the protein remaining in the soluble phase upon ultracentrifugation. Addition of up to ~20 mM iron to high CDM resulted in the formation of small fibrous structures that remained in the soluble phase of milk. It appeared that the iron bound to soluble (nonsedimentable) caseins in high-CDM. We observed a decrease in the aqueous phosphorus content of all milks upon iron addition, irrespective of their calcium content. We considered the interaction between aqueous phosphorus and added iron to be responsible for the high iron-binding capacity of the proteins in milk. The soluble protein-iron complexes formed in high-CDM (~70% calcium depletion) could be used as an effective iron fortificant for a range of food products because of their good solubility characteristics. PMID:25648803

Mittal, V A; Ellis, A; Ye, A; Das, S; Singh, H

2015-04-01

288

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

289

Iron acquisition and allocation in stramenopile algae.  

PubMed

The essential element iron has a low biological availability in the surface ocean where photosynthetic organisms live. Recent advances in our understanding of iron acquisition mechanisms in brown algae and diatoms (stramenopile algae) show the importance of the reduction of ferric to ferrous iron prior to, or during, transport in the uptake process. The uses of iron in photosynthetic stramenopiles resembles that in other oxygenic organisms, although (with the exception of the diatom Thalassiosira oceanica from an iron-deficient part of the ocean) they lack plastocyanin, instead using cytochrome c 6, This same diatom further economizes genotypically on the use of iron in photosynthesis by decreasing the expression of photosystem I, cytochrome c 6, and the cytochrome b 6 f complex per cell and per photosystem II relative to the coastal Thalassiosira pseudonana; similar changes occur phenotypically in response to iron deficiency in other diatoms such as Phaeodactylum tricornutum. In some diatoms grown under iron-limiting conditions, essentially all of the iron in the cells can be accounted for by the iron occurring in catalytic proteins. However, stramenopiles can store iron. Genomic studies show that pennate, but not centric, diatoms have the iron storage protein ferritin. While Mössbauer and X-ray analysis of (57)Fe-labelled Ectocarpus siliculosus shows iron in an amorphous mineral phase resembling the core of ferritin, the genome shows no protein with significant sequence similarity to ferritin. PMID:23658428

Raven, John A

2013-05-01

290

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

291

Intravenous iron therapy: well-tolerated, yet not harmless.  

PubMed

In the majority of patients with chronic renal failure, it is essential to substitute erythropoietic agents and iron to maintain a haemoglobin level above 11 g dL-1. Intravenous iron is more effective than oral iron. Substitution of intravenous iron is mainly performed using iron(III)-hydroxide-sucrose complex (iron sucrose) and iron(III)-sodium-gluconate in sucrose (iron gluconate), and is, in general, well-tolerated. Nonetheless, intravenous iron therapy has effects on endothelial cells, polymorphonuclear leucocytes and cytokines which are most likely related to non-transferrin bound labile iron. These effects suggest a role of iron in infection or atherosclerosis. Yet, not all available data support the association of iron with infection and atherosclerosis. A recent trial showed that iron sucrose is safe when given as treatment for iron deficiency or for maintenance of iron stores. Nevertheless, iron therapy should be handled with caution but its use should not be feared whenever indicated. PMID:16281958

Sengölge, G; Hörl, W H; Sunder-Plassmann, G

2005-12-01

292

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

293

Magnetism in dense hexagonal iron  

PubMed Central

The magnetic state of hexagonal close-packed iron has been the subject of debate for more than three decades. Although Mössbauer measurements find no evidence of the hyperfine splitting that can signal the presence of magnetic moments, density functional theory predicts an antiferromagnetic (afm) ground state. This discrepancy between theory and experiment is now particularly important because of recent experimental findings of anomalous splitting in the Raman spectra and the presence of superconductivity in hexagonal close-packed iron, which may be caused by magnetic correlations. Here, we report results from first principles calculations on the previously predicted theoretical collinear afm ground state that strongly support the presence of afm correlations in hexagonal close-packed iron. We show that anomalous splitting of the Raman mode can be explained by spin–phonon interactions. Moreover, we find that the calculated hyperfine field is very weak and would lead to hyperfine splitting below the resolution of Mössbauer experiments. PMID:14694193

Steinle-Neumann, Gerd; Stixrude, Lars; Cohen, Ronald E.

2004-01-01

294

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

295

Iron chelation and multiple sclerosis  

PubMed Central

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

296

Disassembling Iron Availability to Phytoplankton  

PubMed Central

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 CO2 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

297

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2011 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity... Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2011-04-01

298

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2010 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity... Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2010-04-01

299

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2012 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity... Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2012-04-01

300

Human Frataxin: Iron And Ferrochelatase Binding Surface  

SciTech Connect

The coordinated iron structure and ferrochelatase binding surface of human frataxin have been characterized to provide insight into the protein's ability to serve as the iron chaperone during heme biosynthesis.

Bencze, K.Z.; Yoon, T.; Millan-Pacheco, C.; Bradley, P.B.; Pastor, N.; Cowan, J.A.; Stemmler, T.L.

2009-06-02

301

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

302

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

303

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

304

Ferride geochemistry of Swedish precambrian iron ores  

NASA Astrophysics Data System (ADS)

Chemical analysis for major and trace elements have been performed on 30 Swedish Precambrian iron ores and on some from Iran and Chile. The Swedish ores consist of apatite iron ores, quartz-banded iron ores, skarn and limestone iron ores from the two main ore districts of Sweden, the Bergslagen and the Norrbotten province. Some Swedish titaniferous iron ores were also included in the investigation. The trace element data show that the Swedish ores can be subdivided into two major groups: 1. orthomagmatic and exhalative, 2. sedimentary. Within group 1 the titaniferous iron ores are distinguished by their high Ti-contents. From the ferride contents of the Kiruna apatite iron ores, the ores are considered to be mobilization products of skarn iron ores from the Norbotten province.

Loberg, B. E. H.; Horndahl, A.-K.

1983-10-01

305

Integrated Neighborhood and Integrated Education  

ERIC Educational Resources Information Center

The author is executive director of National Neighbors, a nationwide federation of interracial neighborhoods working to strengthen and encourage successful integrated communities, and to keep integrated schools integrated so that integrated neighborhoods can stay that way. (Author/JM)

Milgram, Jean Gregg

1974-01-01

306

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

307

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

308

Can an increase in leaf iron reductase activity enhance seed iron accumulation in soybean?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron is an important micronutrient for human nutrition, with plant foods providing a significant amount of dietary iron in certain population groups, and in some cases, providing the sole source of dietary iron. Because iron deficiency is unfortunately common in many human populations, we have been...

309

ABSORPTION OF NONHEME, BUT NOT HEME IRON, IS SUBSTANTIALLY REDUCED WITH HIGH IRON STORES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Humans absorb heme iron from meat, poultry and fish more efficiently than nonheme iron, and high consumption may increase body iron stores, and possibly oxidative stress. Results from previous studies of heme and nonheme iron bioavailability, measured separately for men and for women, were combined ...

310

Intestinal over-expression of iron transporters induces iron overload in birds in captivity  

Microsoft Academic Search

Hereditary hemochromatosis (HH) is a frequent genetic disease of older subjects of northern European descent. It is characterized by increased iron absorption and severe iron overloading in parenchymal organs. A similar disturbance of iron metabolism occurs in specific animal species in captivity. To address the key features leading to high absorption and thus to iron overload in these animals, we

Asl? Mete; Ruud Jalving; Bernard A. van Oost; Jaap E. van Dijk; Joannes J. M. Marx

2005-01-01

311

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

312

Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer  

E-print Network

occur on shoulder slopes above playa lakes. At high pH, soil Fe is very insoluble and the bicarbonate crop following failed cotton in the Texas High Plains. However, the widespread occurrence of high pH soils in our region is conducive to "lime-induced chlorosis" or iron (Fe) deficiency in soybean. High pH

Mukhtar, Saqib

313

Antioxidant capacity of parsley cells (Petroselinum crispum L.) in relation to iron-induced ferritin levels and static magnetic field.  

PubMed

This study was aimed to evaluate antioxidant response of parsley cells to 21 ppm iron and static magnetic field (SMF; 30 mT). The activity of catalase (CAT) and ascorbate peroxidase (APX) and the contents of malonyldialdehyde, iron and ferritin were measured at 6 and 12 h after treatments. Exposure to SMF increased the activity of CAT in treated cells, while combination of iron and SMF treatments as well as iron supply alone decreased CAT activity, compared to that of control cells. Combination of SMF with iron treatment reduced iron content of the cells and ameliorated mal effect of iron on CAT activity. All treatments reduced APX activity; however, the content of total ascorbate increased in response to iron and SMF+iron. The results showed that among the components of antioxidant system of parsley cells, enhanced activity of CAT in SMF-treated cells and increase of ascorbate in SMF+Fe-treated ones were responsible for the maintenance of membranes integrity. Ferritin contents of SMF- and SMF+Fe-treated cells also decreased significantly 12 h after treatments, compared to those of the control cells. These results cast doubt on the proposed functions of ferritin as a putative reactive oxygen species detoxifying molecule. PMID:23323716

Rajabbeigi, Elham; Ghanati, Faezeh; Abdolmaleki, Parviz; Payez, Atefeh

2013-12-01

314

Aggregates of iron in ytterbium films  

Microsoft Academic Search

Films of ytterbium doped with iron (0.3–1.6 at.% Fe) have been prepared by co-deposition of atomic beams of the elements onto\\u000a Kapton substrates under high vacuum. Iron is immiscible in ytterbium and various iron species are expected to occur. XRD reveals\\u000a a mixture of fcc and hcp ytterbium. The Mössbauer spectra are interpreted with contributions from monomeric iron on interstitial\\u000a sites,

W. T. Herrera; C. Rojas-Ayala; I. S. Dinóla; E. C. Passamani; M. Kraken; J. Engelke; E. Baggio-Saitovitch; F. J. Litterst

315

Iron supplementation and the female soldier.  

PubMed

Twenty-two percent of women in the United States are iron deficient. Iron deficiency adversely affects immune function as well as physical and cognitive performance. Although the risk of developing iron deficiency is high for female soldiers, this risk can be minimized with proper nutritional guidance. Recommended dietary modifications include (1) heme iron consumption, (2) ingestion of vitamin C and protein with meals, and (3) discontinued tea and coffee consumption with meals. PMID:16673742

Johnson, Anthony E

2006-04-01

316

The impact of maternal iron deficiency and iron deficiency anemia on child’s health  

PubMed Central

Iron deficiency anemia is extremely common, particularly in the developing world, reaching a state of global epidemic. Iron deficiency during pregnancy is one of the leading causes of anemia in infants and young children. Many women go through the entire pregnancy without attaining the minimum required intake of iron. This review aims to determine the impact of maternal iron deficiency and iron deficiency anemia on infants and young children. Extensive literature review revealed that iron deficiency is a global nutritional problem affecting up to 52% of pregnant women. Many of these women are symptomatic. Lack of proper weight gain during pregnancy is an important predictor of iron deficiency. PMID:25719576

Abu-Ouf, Noran M.; Jan, Mohammed M.

2015-01-01

317

The impact of maternal iron deficiency and iron deficiency anemia on child's health.  

PubMed

Iron deficiency anemia is extremely common, particularly in the developing world, reaching a state of global epidemic. Iron deficiency during pregnancy is one of the leading causes of anemia in infants and young children. Many women go through the entire pregnancy without attaining the minimum required intake of iron. This review aims to determine the impact of maternal iron deficiency and iron deficiency anemia on infants and young children. Extensive literature review revealed that iron deficiency is a global nutritional problem affecting up to 52% of pregnant women. Many of these women are symptomatic. Lack of proper weight gain during pregnancy is an important predictor of iron deficiency. PMID:25719576

Abu-Ouf, Noran M; Jan, Mohammed M

2015-02-01

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

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

321

Physical properties of iron-sulfur Fe6S6 superclusters important for biological systems.  

PubMed

The theoretical analysis of the thermal and magnetic properties of iron-sulfur superclusters has been studied by taking into account Heisenberg interactions and resonance delocalizations (double exchange interactions). The numerical calculations are based on the determination of the lowest energy states for different values of spins (from S = 0.5 to S = 12.5) and Heisenberg exchange integrals. It is shown that the spin magnetic susceptibility of the iron-sulfur superclusters decreases with increasing temperature and increases with increasing the double exchange parameter. In contrast to the susceptibility, the heat capacity decreases with the increasing values of the double exchange parameter. It was theoretically found that spin of ground state for the iron-sulfur supercluster is equal to 0.5. Based on our results, we can state that the Heisenberg model of spin interactions describes the thermodynamic properties of the iron-sulfur superclusters which are the important constituents of proteins and enzymes. PMID:21446408

Ozga, Julita; Matusiewicz, Marek; Kasperczyk, Jacek; Kozlowski, Gregory; Kityk, Ivan

2011-01-01

322

Iron: the hard player in diabetes pathophysiology.  

PubMed

The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the ?-cell is complex. Excess free iron is toxic, but at the same time, iron is required for normal ?-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to present and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced ?-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1? facilitates divalent metal transporter 1 (DMT1)-induced ?-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides the relay between inflammation and oxidative ?-cell damage. Iron chelation may be a potential therapeutic approach to reduce disease severity and mortality among diabetes patients. However, the therapeutic effect and safety of iron reduction need to be tested in clinical trials before dietary interventions or the use of iron chelation therapy titrated to avoid anaemia. PMID:24521359

Hansen, J B; Moen, I W; Mandrup-Poulsen, T

2014-04-01

323

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

324

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

325

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

326

RED CELLS, IRON, AND ERYTHROPOIESIS Brief report  

E-print Network

RED CELLS, IRON, AND ERYTHROPOIESIS Brief report Agenome-wide association analysis of serum iron that promotes iron absorption and recycling by inhibiting hepcidin antimicrobial pep- tide transcription, smaller red cells, and more variability in red cell size (high red blood cell distribu- tion width). Our

Abecasis, Goncalo

327

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

328

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

329

High-Temperature Oxidation of Iron Whiskers  

Microsoft Academic Search

Single crystal ?-iron whiskers have been used to study early stages in the oxidation of iron at high temperatures. Well defined oxide patterns are observed on clean iron surfaces and there are characteristic differences between the patterns on {100} and {110} faces. These differences tend to be eliminated if a natural oxide film is present before the high temperature oxidation

J. V. Laukonis; R. V. Coleman

1959-01-01

330

Enantioselective iron-catalyzed intramolecular cyclopropanation reactions.  

PubMed

An iron-catalyzed asymmetric intramolecular cyclopropanation was realized in high yields and excellent enantioselectivity (up to 97%?ee) by using the iron complexes of chiral spiro-bisoxazoline ligands as catalysts. The superiority of iron catalysts exhibited in this reaction demonstrated the potential abilities of this sustainable metal in asymmetric carbenoid transformation reactions. PMID:25283384

Shen, Jun-Jie; Zhu, Shou-Fei; Cai, Yan; Xu, Huan; Xie, Xiu-Lan; Zhou, Qi-Lin

2014-11-24

331

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2014 CFR

...i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...follows: (i) For the prevention of anemia due to iron deficiency,...

2014-04-01

332

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2011 CFR

...i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...follows: (i) For the prevention of anemia due to iron deficiency,...

2011-04-01

333

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2013 CFR

...i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...follows: (i) For the prevention of anemia due to iron deficiency,...

2013-04-01

334

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2012 CFR

...i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular...follows: (i) For the prevention of anemia due to iron deficiency,...

2012-04-01

335

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

336

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, ChildrenÂ?s Hospital Boston, Dana-Farber Cancer Institute)

2006-04-01

337

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

338

Magnetic properties of iron and iron platinum alloys synthesized via microemulsion techniques  

Microsoft Academic Search

In this article, metallic iron, and iron\\/platinum alloys nanoparticles have been synthesized via chemical assembly and magnetically characterized. Fabrication of iron and iron\\/platinum particles was achieved by reducing 0.1 M aqueous metal salts confined in the polar portions of inverse micelles of cetyltrimethylammonium bromide with borohydride. The dc susceptibility of a sample of 8 nm iron nanoparticles exhibits a blocking

E. E. Carpenter; J. A. Sims; J. A. Wienmann; W. L. Zhou; C. J. O’Connor

2000-01-01

339

Iron supplementation improves progressive fatigue resistance during dynamic knee extensor exercise in iron-depleted  

Microsoft Academic Search

Background: Tissue iron depletion may negatively affect endurance performance and muscle fatigability. Objective: We investigated tissue-level iron depletion and pro- gressive fatigue of the quadriceps during dynamic knee-extension exercise in young women. Design: Twenty iron-depleted (serum ferritin < 20 ? g\\/L), nonane- mic (hemoglobin > 110 g\\/L) women (x - ± SEM age: 29.1 ± 1.2 y) received iron (iron

Tom D Brutsaert; Sonia Hernandez-Cordero; Juan Rivera; Tracey Viola; Gail Hughes; Jere D Haas

340

Sensory characteristics and iron dialyzability of gluten-free bread fortified with iron  

Microsoft Academic Search

The objectives of the present study were (a) to produce gluten-free bread, fortified with iron (GFB-Fe), using selected iron compounds (ferric pyrophosphate, ferric pyrophosphate with emulsifiers, NaFeEDTA, electrolytic iron, ferrous gluconate, ferrous lactate and ferrous sulphate) (b) to test sensory characteristics of the GFB-Fe (feel-mouth texture, crumb colour, aroma and taste) (c) to compare iron dialyzability of various iron compounds

Alexandra Kiskini; Konstantina Argiri; Michael Kalogeropoulos; Michael Komaitis; Athanasios Kostaropoulos; Ioanna Mandala; Maria Kapsokefalou

2007-01-01

341

Infant iron status affects iron absorption in Peruvian breastfed infants at 2 and 5 mo of age  

Technology Transfer Automated Retrieval System (TEKTRAN)

Effects of prenatal iron supplementation on maternal postpartum iron status and early infant iron homeostasis remain largely unknown. We examined iron absorption and growth in exclusively breastfed infants in relation to fetal iron exposure and iron status during early infancy. Longitudinal, paired ...

342

Formation of iron-rich shelled structures by microbial communities  

NASA Astrophysics Data System (ADS)

this paper, we describe the discovery and characterization of shelled structures that occur inside galleries of Pyrenees mines. The structures are formed by the mineralization of iron and zinc oxides, dominantly franklinite (ZnFe2O4) and poorly ordered goethite (?-FeO(OH)). Subsurface oxidation and hydration of polymetallic sulfide orebodies produce solutions rich in dissolved metal cations including Fe2+/3+ and Zn2+. The microbially precipitated shell-like structure grows by lateral or vertical stacking of thin laminae of iron oxide particles which are accreted mostly by fungal filaments. The resulting structures are composed of randomly oriented aggregates of needle-like, uniform-sized crystals, suggesting some biological control in the structure formation. Such structures are formed by the integration of two separated shells, following a complex process driven likely by different strategies of fungal microorganisms that produced the complex macrostructure.

Fernández-Remolar, David C.; Santamaría, Joan; Amils, Ricardo; Parro, Victor; Gómez-Ortíz, D.; Izawa, Matthew R. M.; Banerjee, Neil R.; Pérez Rodríguez, Raúl; Rodríguez, Nuria; López-Martínez, Nieves

2015-01-01

343

Dynamic transition in supercritical iron.  

PubMed

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

344

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

345

THE ANGLE IRON BAT GATE  

Microsoft Academic Search

This paper discusses the evolution of the American Cave Conservation Association (ACCA) angle iron gate types. Topics discussed include: air flow testing, materials, security, and advantages of these designs. Brief History of Gate Installation Many early gates installed in caves and mines caused more problems and damage to resources than they protected. Airflow disturbances changed temperature and humidity. Paints added

Roy D. Powers Jr

346

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

347

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

348

Corrosion of ductile iron piping  

Microsoft Academic Search

A compilation of 20 classic NACE papers on the subject, dating from 1957 to 1994. Papers include: Corrosion of Municipal Iron Watermains, Protecting Water Pipelines with Pipeline Coatings Conforming to American Water Works Association Coating Standards, Analysis of Aged Water Distribution Systems, and many more.

Szeliga

1995-01-01

349

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,...

350

Coal desulfurization with iron pentacarbonyl  

NASA Technical Reports Server (NTRS)

Coal desulfurization with iron pentacarbonyl treatment under mild conditions removes up to eighty percent of organic sulfur. Preliminary tests on treatment process suggest it may be economical enough to encourage investigation of use for coal desulfurization. With mild operating conditions, process produces environmentally-acceptable clean coal at reasonable cost.

Hsu, G. C.

1979-01-01

351

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...

352

SYNTHESIS OF IRON-GERMANIUM  

E-print Network

SYNTHESIS OF IRON-GERMANIUM Summer Research 2010 Rohan Isaac Advisor: Dr. Amer Lahamer #12;What the escape of a percentage of germanium by starting initially with more germanium than necessary, and anticipating that the same percent of germanium will escape under the same conditions. Cook for 6 hours at 850

Baltisberger, Jay H.

353

Iron toxicity: relevance for dialysis patients.  

PubMed

Iron deficiency is common among patients with advanced kidney disease, particularly those requiring hemodialysis. Intravenous iron is a convenient treatment to supplement iron and is widely used among hemodialysis patients. Its efficacy is well established that, with treatment, hemoglobin levels rise and erythropoiesis-stimulating agent dose requirements are reduced. However, the safety of intravenous iron with respect to patient-centered outcomes has not been adequately studied. A variety of studies have indicated potential safety concerns, but most have been of small numbers of patients and with end points studied that have unclear clinical relevance. In this study, issues related to iron toxicity are reviewed. PMID:24166458

Fishbane, Steven; Mathew, Anna; Vaziri, Nosratola D

2014-02-01

354

[Treatment of disorders of iron metabolism].  

PubMed

When prescribing oral iron preparations, consideration must be given in particular to the question of bioavailability. In this connection, ferrous sulfate preparations are to be preferred. The simultaneous ingestion of tea, coffee or dairy products reduces the absorption of iron, while ascorbic acid increases it. Gastrointestinal side effects of oral iron substitution are usually dose-dependent. If absorption or mobilization disorders, gastrointestinal diseases or signs of intolerance to oral administration are present, iron must be administered via the parenteral route. To avoid toxicity, accurate calculation of the dose is necessary before injection. Since intolerance reactions extending to anaphylactic shock can occur, the indication for iron preparations must be rigorously applied. PMID:15625935

Pinggera, Wulf

2004-11-25

355

Genetic and biochemical markers in patients with Alzheimer's disease support a concerted systemic iron homeostasis dysregulation.  

PubMed

Alzheimer's disease (AD) is the most common form of dementia in the elderly individuals, resulting from a complex interaction between environmental and genetic factors. Impaired brain iron homeostasis has been recognized as an important mechanism underlying the pathogenesis of this disease. Nevertheless, the knowledge gathered so far at the systemic level is clearly insufficient. Herein, we used an integrative approach to study iron metabolism in the periphery, at both genotypic and phenotypic levels, in a sample of 116 patients with AD and 89 healthy control subjects. To assess the potential impact of iron metabolism on the risk of developing AD, genetic analyses were performed along with the evaluation of the iron status profile in peripheral blood by biochemical and gene expression studies. The results obtained showed a significant decrease of serum iron, ferritin, and transferrin concentrations in patients compared with the control subjects. Also, a significant decrease of ferroportin (SLC40A1) and both transferrin receptors TFRC and TFR2 transcripts was found in peripheral blood mononuclear cells from patients. At the genetic level, significant associations with AD were found for single nucleotide polymorphisms in TF, TFR2, ACO1, and SLC40A1 genes. Apolipoprotein E gene, a well-known risk factor for AD, was also found significantly associated with the disease in this study. Taken together, we hypothesize that the alterations on systemic iron status observed in patients could reflect an iron homeostasis dysregulation, particularly in cellular iron efflux. The intracellular iron accumulation would lead to a rise in oxidative damage, contributing to AD pathophysiology. PMID:24199959

Crespo, Ângela C; Silva, Bruno; Marques, Liliana; Marcelino, Erica; Maruta, Carolina; Costa, Sónia; Timóteo, Angela; Vilares, Arminda; Couto, Frederico Simões; Faustino, Paula; Correia, Ana Paula; Verdelho, Ana; Porto, Graça; Guerreiro, Manuela; Herrero, Ana; Costa, Cristina; de Mendonça, Alexandre; Costa, Luciana; Martins, Madalena

2014-04-01

356

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

NASA Astrophysics Data System (ADS)

Previous 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

357

Association of catalytic iron with cardiovascular disease.  

PubMed

The ability of iron to cycle reversibly between its ferrous and ferric oxidation states is essential for the biological functions of iron but may contribute to vascular injury through the generation of powerful oxidant species. We examined the association between chemical forms of iron that can participate in redox cycling, often referred to as "catalytic" or "labile" iron, and cardiovascular disease (CVD). In our cross-sectional study of 496 participants, 85 had CVD. Serum catalytic iron was measured using the bleomycin-detectable iron assay that detects biologically active iron. The odds of existing CVD for subjects in the upper third of catalytic iron were 10 times that of subjects with lower catalytic iron in unadjusted analyses. The association was decreased by 1/2 by age adjustment, but little additional attenuation occurred after adjusting for age, Framingham Risk Score, estimated glomerular filtration rate, hypertension status, high-density lipoprotein cholesterol, and systolic blood pressure, with the association remaining strong and significant (odds ratio 3.8, 95% confidence interval 1.4 to 10.1). In conclusion, we provide preliminary evidence for a strong detrimental association between high serum catalytic iron and CVD even after adjusting for several co-morbid conditions; however, broader prospective studies are needed to confirm these findings, which would support therapeutic trials to assess the beneficial effects of iron chelators on CVD. PMID:22071209

Rajapurkar, Mohan M; Shah, Sudhir V; Lele, Suhas S; Hegde, Umapati N; Lensing, Shelly Y; Gohel, Kalpesh; Mukhopadhyay, Banibrata; Gang, Sishir; Eigenbrodt, Marsha L

2012-02-01

358

Duodenal iron proteins in idiopathic hemochromatosis.  

PubMed Central

This study was undertaken to assess the relationship between iron absorption and the concentration of duodenal iron proteins in normal subjects and patients with idiopathic hemochromatosis (IH). Biopsies were obtained endoscopically from the duodenum in 17 normal subjects, 3 of whom were mildly iron deficient, and 7 patients with untreated IH. The absorption of both heme and nonheme iron was increased in IH despite a 20-fold elevation in serum ferritin. Immunoassays using MAb were used to measure transferrin, H-rich ferritin, and L-rich ferritin in mucosal samples. Mucosal transferrin concentrations in normal subjects did not correlate with either iron status or iron absorption, indicating that mucosal transferrin plays no physiological role in iron absorption. Mucosal transferrin was significantly lower in IH, presumably because of a decrease in mucosal transferrin receptors. Mucosal H and L ferritin concentrations were directly related to body iron stores and inversely related to iron absorption in normal subjects. In IH, mucosal H and L ferritin failed to increase in parallel with the serum ferritin, but were appropriate for the level of iron absorption. The relationship of mucosal H/L ferritin in IH did not differ from that observed in normal subjects. Our findings indicate that the major abnormality in duodenal iron proteins in IH is a parallel decrease in the concentration of H- and L-rich ferritin. It is not evident whether this is the result or the cause of the absorptive abnormality. PMID:2910911

Whittaker, P; Skikne, B S; Covell, A M; Flowers, C; Cooke, A; Lynch, S R; Cook, J D

1989-01-01

359

Kinetics of iron oxidation upon polyphenol binding.  

PubMed

Polyphenol prevention of iron-mediated DNA damage occurs primarily through iron binding. Once bound, iron in the Fe(2+)-polyphenol complex autooxidizes to Fe(3+) in the presence of O(2). To determine the correlation between the rate of Fe(2+)-polyphenol autooxidation and polyphenol antioxidant ability, kinetic studies at pH = 6.0 in the presence of oxygen were performed using UV-vis spectrophotometry. Initial rates of iron-polyphenol complex oxidation for epigallocatechin gallate (EGCG), methyl-3,4,5-trihydroxybenzoate (MEGA), gallic acid (GA), epicatechin (EC), and methyl-3,4-dihydroxybenzoate (MEPCA) were in the range of 0.14-6.7 min(-1). Polyphenols with gallol groups have faster rates of iron oxidation than their catechol analogs, suggesting that stronger iron binding results in faster iron oxidation. Concentrations of polyphenol, Fe(2+), and O(2) were varied to investigate the dependence of the Fe(2+)-polyphenol autooxidation on these reactants for MEGA and MEPCA. For these analogous gallate and catecholate complexes of Fe(2+), iron oxidation reactions were first order in Fe(2+), polyphenol, and O(2), but gallate complexes show saturation behavior at much lower Fe(2+) concentrations. Thus, gallol-containing polyphenols promote iron oxidation at a significantly faster rate than analogous catechol-containing compounds, and iron oxidation rate also correlates strongly with polyphenol inhibition of DNA damage for polyphenol compounds with a single iron-binding moiety. PMID:20871896

Perron, Nathan R; Wang, Hsiao C; Deguire, Sean N; Jenkins, Michael; Lawson, Mereze; Brumaghim, Julia L

2010-11-01

360

Cellular Iron Distribution in Bacillus anthracis  

PubMed Central

Although successful iron acquisition by pathogens within a host is a prerequisite for the establishment of infection, surprisingly little is known about the intracellular distribution of iron within bacterial pathogens. We have used a combination of anaerobic native liquid chromatography, inductively coupled plasma mass spectrometry, principal-component analysis, and peptide mass fingerprinting to investigate the cytosolic iron distribution in the pathogen Bacillus anthracis. Our studies identified three of the major iron pools as being associated with the electron transfer protein ferredoxin, the miniferritin Dps2, and the superoxide dismutase (SOD) enzymes SodA1 and SodA2. Although both SOD isozymes were predicted to utilize manganese cofactors, quantification of the metal ions associated with SodA1 and SodA2 in cell extracts established that SodA1 is associated with both manganese and iron, whereas SodA2 is bound exclusively to iron in vivo. These data were confirmed by in vitro assays using recombinant protein preparations, showing that SodA2 is active with an iron cofactor, while SodA1 is cambialistic, i.e., active with manganese or iron. Furthermore, we observe that B. anthracis cells exposed to superoxide stress increase their total iron content more than 2-fold over 60 min, while the manganese and zinc contents are unaffected. Notably, the acquired iron is not localized to the three identified cytosolic iron pools. PMID:22178968

Tu, Wang Yung; Pohl, Susanne; Gray, Joe; Robinson, Nigel J.; Harwood, Colin R.

2012-01-01

361

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

362

Carbon in iron phases under high pressure  

NASA Astrophysics Data System (ADS)

The influence of carbon impurities on the properties of iron phases (bcc, hcp, dhcp, fcc) has been studied using the first-principles projector augmented-wave (PAW) method for a wide pressure range. It is shown that the presence of ~6 at. % of interstitial carbon has a little effect on the calculated structural sequence of the iron phases under high pressure. The bcc -> hcp transition both for pure iron and iron containing carbon takes place around 9 GPa. According to the enthalpies comparison, the solubility of carbon into the iron solid is decreased by high pressure. The coexistence of iron carbide (Fe3C) + pure hcp Fe is most stable phase at high pressure compared with other phases. Based on the analysis of the pressure-density dependences for Fe3C and hcp Fe, we suggest that there might be some fraction of iron carbide present in the core.

Huang, L.; Skorodumova, N. V.; Belonoshko, A. B.; Johansson, B.; Ahuja, R.

2005-11-01

363

Effects of iron-reducing bacteria on carbon steel corrosion induced by thermophilic sulfate-reducing consortia.  

PubMed

Four thermophilic bacterial species, including the iron-reducing bacterium Geobacillus sp. G2 and the sulfate-reducing bacterium Desulfotomaculum sp. SRB-M, were employed to integrate a bacterial consortium. A second consortium was integrated with the same bacteria, except for Geobacillus sp. G2. Carbon steel coupons were subjected to batch cultures of both consortia. The corrosion induced by the complete consortium was 10 times higher than that induced by the second consortium, and the ferrous ion concentration was consistently higher in iron-reducing consortia. Scanning electronic microscopy analysis of the carbon steel surface showed mineral films colonized by bacteria. The complete consortium caused profuse fracturing of the mineral film, whereas the non-iron-reducing consortium did not generate fractures. These data show that the iron-reducing activity of Geobacillus sp. G2 promotes fracturing of mineral films, thereby increasing steel corrosion. PMID:24225375

Valencia-Cantero, Eduardo; Peña-Cabriales, Juan José

2014-02-28

364

Transient iron-overload with bleomycin-detectable iron present during cardiopulmonary bypass surgery.  

PubMed

Extracorporeal circulation of blood during cardiopulmonary bypass surgery exposes cells to non-physiological surfaces and shear stress which can activate several regulatory cascades, and neutrophils to release superoxide and hydrogen peroxide. Shear stresses generated by pumps and suction systems cause lysis of red blood cells and the release of haemoglobin. Together the release of reactive forms of oxygen and haemoglobin can lead to the appearance of low molecular mass chelatable iron (bleomycin-detectable iron). All patients undergoing open heart surgery appear to release iron to plasma transferrin, increasing its iron saturation. In 13% of patients, however, the transferrin became fully iron-saturated, and by the end of open-heart surgery we could detect bleomycin-chelatable iron in the plasma. Saturation of transferrin with iron eliminates its iron-binding antioxidant properties, which can result in a stimulation of iron-dependent radical damage to selected detector molecules. PMID:7522839

Pepper, J R; Mumby, S; Gutteridge, J M

1994-08-01

365

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

366

Unique Host Iron Utilization Mechanisms of Helicobacter pylori Revealed with Iron-Deficient Chemically Defined Media?  

PubMed Central

Helicobacter pylori chronically infects the gastric mucosa, where it can be found free in mucus, attached to cells, and intracellularly. H. pylori requires iron for growth, but the sources of iron used in vivo are unclear. In previous studies, the inability to culture H. pylori without serum made it difficult to determine which host iron sources might be used by H. pylori. Using iron-deficient, chemically defined medium, we determined that H. pylori can bind and extract iron from hemoglobin, transferrin, and lactoferrin. H. pylori can use both bovine and human versions of both lactoferrin and transferrin, contrary to previous reports. Unlike other pathogens, H. pylori preferentially binds the iron-free forms of transferrin and lactoferrin, which limits its ability to extract iron from normal serum, which is not iron saturated. This novel strategy may have evolved to permit limited growth in host tissue during persistent colonization while excessive injury or iron depletion is prevented. PMID:20176792

Senkovich, Olga; Ceaser, Shantelle; McGee, David J.; Testerman, Traci L.

2010-01-01

367

Influence of inflammatory disorders and infection on iron absorption and efficacy of iron- fortified foods.  

PubMed

The provision of iron- fortified foods is a common strategy to prevent iron deficiency; however, ensuring adequate iron absorption is a challenge. Iron bioavailability depends on the choice of iron compound, the presence enhancers and inhibitors of absorption in the food matrix, and the physiological state of the consumer, including iron status, other nutritional deficiencies and inflammatory disorders. Inflammation associated with infections and inflammatory disorders would be expected to decrease iron absorption and reduce the efficacy of iron- fortified foods. The decreased absorption is due to an increase in circulating hepcidin in response to inflammatory cytokines. Hepcidin degrades ferroportin and blocks the passage of iron from the intestinal cell to the plasma. This is the innate immune response to infections and aims to restrict pathogen growth by restricting iron supply. Stable isotope studies have reported women and children with chronic malaria parasitemia or febrile malaria to have increased inflammatory cytokines, increased hepcidin and much decreased iron absorption. No studies have specifically investigated the efficacy of iron- fortified foods in the absence and presence of infections. In contrast, inflammation and increased hepcidin associated with adiposity in overweight have been linked to both lower iron absorption and the decreased efficacy of iron- fortified foods. PMID:25762975

Hurrell, Richard F

2012-01-01

368

Olfactory ferric and ferrous iron absorption in iron-deficient rats  

PubMed Central

The absorption of metals from the nasal cavity to the blood and the brain initiates an important route of occupational exposures leading to health risks. Divalent metal transporter-1 (DMT1) plays a significant role in the absorption of intranasally instilled manganese, but whether iron uptake would be mediated by the same pathway is unknown. In iron-deficient rats, blood 59Fe levels after intranasal administration of the radioisotope in the ferrous form were significantly higher than those observed for iron-sufficient control rats. Similar results were obtained when ferric iron was instilled intranasally, and blood levels of 59Fe were even greater in the iron-deficient rats compared with the amount of ferrous iron absorbed. Experiments with Belgrade (b/b) rats showed that DMT1 deficiency limited ferric iron uptake from the nasal cavity to the blood compared with +/b controls matched for iron deficiency. These results indicate that olfactory uptake of ferric iron by iron-deficient rats involves DMT1. Western blot experiments confirmed that DMT1 levels are significantly higher in iron-deficient rats compared with iron-sufficient controls in olfactory tissue. Thus the molecular mechanism of olfactory iron absorption is regulated by body iron status and involves DMT1. PMID:22492739

Ruvin Kumara, V. M.

2012-01-01

369

Influence of Inflammatory Disorders and Infection on Iron Absorption and Efficacy of Iron- Fortified Foods  

PubMed Central

The provision of iron- fortified foods is a common strategy to prevent iron deficiency; however, ensuring adequate iron absorption is a challenge. Iron bioavailability depends on the choice of iron compound, the presence enhancers and inhibitors of absorption in the food matrix, and the physiological state of the consumer, including iron status, other nutritional deficiencies and inflammatory disorders. Inflammation associated with infections and inflammatory disorders would be expected to decrease iron absorption and reduce the efficacy of iron- fortified foods. The decreased absorption is due to an increase in circulating hepcidin in response to inflammatory cytokines. Hepcidin degrades ferroportin and blocks the passage of iron from the intestinal cell to the plasma. This is the innate immune response to infections and aims to restrict pathogen growth by restricting iron supply. Stable isotope studies have reported women and children with chronic malaria parasitemia or febrile malaria to have increased inflammatory cytokines, increased hepcidin and much decreased iron absorption. No studies have specifically investigated the efficacy of iron- fortified foods in the absence and presence of infections. In contrast, inflammation and increased hepcidin associated with adiposity in overweight have been linked to both lower iron absorption and the decreased efficacy of iron- fortified foods.

Hurrell, Richard F.

2014-01-01

370

Iron metabolism in the pathogenesis of iron-induced kidney injury.  

PubMed

In the past 8 years, there has been renewed interest in the role of iron in both acute kidney injury (AKI) and chronic kidney disease (CKD). In patients with kidney diseases, renal tubules are exposed to a high concentration of iron owing to increased glomerular filtration of iron and iron-containing proteins, including haemoglobin, transferrin and neutrophil gelatinase-associated lipocalin (NGAL). Levels of intracellular catalytic iron may increase when glomerular and renal tubular cells are injured. Reducing the excessive luminal or intracellular levels of iron in the kidney could be a promising approach to treat AKI and CKD. Understanding the role of iron in kidney injury and as a therapeutic target requires insight into the mechanisms of iron metabolism in the kidney, the role of endogenous proteins involved in iron chelation and transport, including hepcidin, NGAL, the NGAL receptor and divalent metal transporter 1, and iron-induced toxic effects. This Review summarizes emerging knowledge, which suggests that complex mechanisms of iron metabolism exist in the kidney, modulated directly or indirectly by cellular iron content, inflammation, ischaemia and oxidative stress. The potential exists for prevention and treatment of iron-induced kidney injury by customized iron removal or relocation, aided by detailed insight into the underlying pathological mechanisms. PMID:23670084

Martines, A M F; Masereeuw, R; Tjalsma, H; Hoenderop, J G; Wetzels, J F M; Swinkels, D W

2013-07-01

371

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

372

Saugus Iron Works: Life and Work at an Early American Industrial Site. Teaching with Historic Places.  

ERIC Educational Resources Information Center

In 1948 archeologists verified that a now overgrown and urbanized landscape along the Saugus River (Massachusetts) was the site of the Saugus Iron Works from 1646 until 1648. That discovery led to a careful, though partly conjectural, reconstruction of the first successful integrated ironmaking plant in the colonial America. The early Puritan…

Whitman, Maryann

373

SURVEY OF FOULING, FOAM, CORROSION, AND SCALING CONTROL IN IRON AND STEEL INDUSTRY RECYCLE SYSTEMS  

EPA Science Inventory

The report gives results of a review of the state-of-the-art for fouling, foaming, corrosion, and scaling control in the treatment and recycle of process waters of integrated iron and steel mills. Areas examined were: (1) the character of the wastewaters generated in the differen...

374

EMISSION FACTORS FOR IRON AND STEEL SOURCES -- CRITERIA AND TOXIC POLLUTANTS  

EPA Science Inventory

The report provides a comprehensive set of emission factors for sources of both criteria and toxic air pollutants in integrated iron and steel plants and specialty electric arc shops (minimills). Emission factors are identified for process sources, and process and open source fug...

375

EMISSION FACTORS FOR IRON AND STEEL SOURCES: CRITERIA AND TOXIC POLLUTANTS  

EPA Science Inventory

The report provides a comprehensive set of emission factors for sources of both criteria and toxic air pollutants in integrated iron and steel plants and specialty electric arc shops (minimills). Emission factors are identified for process sources, and process and open source fug...

376

POLLUTION EFFECTS OF ABNORMAL OPERATIONS IN IRON AND STEEL MAKING. VOLUME II. SINTERING, MANUAL OF PRACTICE  

EPA Science Inventory

The report is one 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, generall...

377

Vintage structure dynamics and climate change policies: the case of US iron and steel  

Microsoft Academic Search

The US iron and steel industry consists of two main sectors—integrated firms producing outputs predominantly from virgin materials and fossil fuels, and electric arc furnaces operating mainly on scrap and electricity. Capacity and market shares of the former have declined for more than three decades, leading to reductions in energy use and emissions as the existing capital stock is retired.

Matthias Ruth; Anthony Amato

2002-01-01

378

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...

379

Status on testing of JENDL-3.2 iron data with shielding benchmarks  

SciTech Connect

Integral test of neutron and secondary gamma-ray production data for the latest version of Japanese Evaluated Nuclear Data Library (JENDL-3.2) has been performed with shielding benchmarks. An evaluation scheme for the benchmark analyses established in Japanese Nuclear Data Committee has been applied to the integral test for iron, and the applicability of JENDL-3.2 has been confirmed for shielding calculations.

Yamano, Naoki [Sumitomo Atomic Energy Ind., Ltd., Tokyo (Japan); Hasegawa, Akira [Japan Atomic Energy Research Institute, Tokai-mura (Japan); Ueki, Kohtaro [Ship Research Institute, Tokyo (Japan); Kawai, Masayoshi [Toshiba Corp., Kawasaki (Japan)

1994-12-31

380

[Growth characteristics and control of iron bacteria on cast iron in drinking water distribution systems].  

PubMed

This study investigated the growth characteristics of iron bacteria on cast iron and relationship between suspended and attached iron bacteria. The steady-state growth of iron bacteria would need 12 d and iron bacteria level in effluents increased 1 lg. Hydraulics influence on iron bacteria level and detachment rate of steady-state attached iron bacteria was not significant. But it could affect the time of attached iron bacteria on cast-iron coupons reaching to steady state. When the chlorine residual was 0.3 mg/L, the iron bacteria growth could be controlled effectively and suspended and attached iron bacteria levels both decreased 1 lg. When the chlorine residual was more than 1.0 mg/L, it could not inactivate the iron bacteria of internal corrosion scale yet. There was little effect on inhibiting the iron bacteria growth that the chlorine residual was 0.05 mg/L in drinking water quality standard of China. The iron bacteria on coupons reached to steady state without disinfectant and then increased the chlorine residual to 1.25 mg/L, the attached iron bacteria level could decrease 2 lg to 3 lg. Under steady-state, the suspended iron bacteria levels were linearly dependent on the attached iron bacteria. The control of iron bacteria in drinking water distribution systems was advanced: maintaining the chlorine residual (0.3 mg/L), flushing the pipeline with high dosage disinfectant, adopting corrosion-resistant pipe materials and renovating the old pipe loop. PMID:20063743

Wang, Yang; Zhang, Xiao-Jian; Chen, Yu-Qiao; Lu, Pin-Pin; Chen, Chao

2009-11-01

381

Fabrication of Iron-Containing Carbon Materials From Graphite Fluoride  

Microsoft Academic Search

Carbon materials containing iron alloy, iron metal, iron oxide or iron halide were fabricated. Typical samples of these metals were estimated to contain 1 iron atom per 3.5 to 5 carbon atoms. Those carbon materials containing iron alloy, iron metal, and\\/or Fe3O4 were magnetic. The kinetics of the fabrication process were studied by exposing graphite fluoride (CF(0.68)) to FeCl3 over

Ching-cheh Hung; Ching-Chen

1996-01-01

382

Iron-tolerant Cyanobacteria as a Tool to Study Terrestrial and Extraterrestrial Iron Deposition  

NASA Technical Reports Server (NTRS)

We are investigating biological mechanisms of terrestrial iron deposition as analogs for Martian hematite recently confirmed by. Possible terrestrial analogs include iron oxide hydrothermal deposits, rock varnish, iron-rich laterites, ferricrete soils, moki balls, and banded iron formations (BIFs). With the discovery of recent volcanic activity in the summit craters of five Martian volcanoes, renewed interest in the iron dynamics of terrestrial hydrothermal environments and associated microorganisms is warranted. In this study we describe a new genus and species of CB exhibiting elevated dissolved iron tolerance and the ability to precipitate hematite on the surface of their exopolymeric sheathes.

Brown, I. I.; Mummey, D.; Cooksey, K. E.; McKay, D. S.

2005-01-01

383

Iron deficiency and obesity: the contribution of inflammation and diminished iron absorption.  

PubMed

Poor iron status affects billions of people worldwide. The prevalence of obesity continues to rise in both developed and developing nations. An association between iron status and obesity has been described in children and adults. The mechanism explaining this relationship remains unknown; however, findings from recent reports suggest that body mass index and inflammation predict iron absorption and affect the response to iron fortification. The relationship between inflammation and iron absorption may be mediated by hepcidin, although further studies will be required to confirm this potential physiological explanation for the increased prevalence of iron deficiency in the obese. PMID:19178651

McClung, James P; Karl, J Philip

2009-02-01

384

Serum iron, total iron binding capacity, plasma copper and hemoglobin types in anemic and poikilocytic calves.  

PubMed Central

Ninety-eight calves were studied to determine if anemia and poikilocytosis were related to iron or copper status or hemoglobin type. No significant differences were found in serum iron, total iron binding capacity, marrow iron, plasma copper or hemoglobin type between affected and normal calves. Poikilocytes were strongly inversely correlated (-0.9177) with age. Calves less than six weeks of age had more poikilocytes, lower serum iron, higher total iron binding capacity, less adult hemoglobin and more neonatal and fetal hemoglobin than calves greater than six weeks of age. Images Fig. 1. PMID:2412677

McGillivray, S R; Searcy, G P; Hirsch, V M

1985-01-01

385

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

386

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

387

Albumin holograms with iron ions  

NASA Astrophysics Data System (ADS)

The preparation of photosensitive films of quail albumen (protein), applying as oxidizing agent, green iron ammonium citrate. Exposed to a He-Cd laser, ? = 442nm, transmission holograms were recorded. We obtained the diffraction patterns reconstructed with He-Ne laser, ?=632.8nm and measuring diffraction efficiencies for first order as a function of exposure energy. Holographic gratings made with these materials exhibit behaviour of self develop. We analyse the experimental results.

Ordóñez-Padilla, M. J.; Olivares-Pérez, A.; Ortiz-Gutiérrez, M.; Juárez-Ramírez, J. C.

2014-02-01

388

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

389

Iron and manganese in lakes  

Microsoft Academic Search

The role of redox processes in determining the chemistry of iron and manganese is considered systematically. Both metals have soluble reduced forms and insoluble oxyhydroxides which are readily interconverted in the vicinity of a redox boundary. Although the oxyhydroxides are dominant in well-oxygenated waters, measureable concentrations of Fe(II) and Mn(II) can be observed, especially where photochemical reduction occurs. Differences in

William Davison

1993-01-01

390

Two genetic loci participate in the regulation by iron of the gene for the human transferrin receptor  

SciTech Connect

Iron regulation of the human transferrin receptor gene was examined in murine cells transformed with chimeric constructs containing the human transferrin receptor gene's promoter and either the structural gene for bacterial chloramphenicol acetyltransferase or the human transferrin receptor cDNA. The activity of the transferrin receptor gene's promoter with the heterologous indicator gene was found to be {approx}3-fold higher in cells treated with the iron chelator desferrioxamine than in cells treated with the iron source, hemin. A higher degree of iron regulation was seen in the expression of the human transferrin receptor cDNA driven by its own promoter. The receptor cDNA under the control of the simian virus 40 early promoter was also iron-regulated. Several human transferrin receptor transcripts differing in their 3{prime} end were produced in the murine cells regardless of the promoter used, with the shorter transcripts being relatively unregulated by iron. Deletion of cDNA corresponding to most of the 3{prime} untranslated portion of the mRNA for the receptor ablated the iron regulation. The authors conclude that at least two genetic elements exist for the regulation of the transferrin receptor gene by iron. One has its locus in the DNA upstream of the transferrin receptor gene's transcription start site, and the other is dependent upon the integrity of the sequences in the 3{prime} end of the gene.

Casey, J.L.; Di Jeso, B.; Rao, K.; Klausner, R.D.; Harford, J.B. (National Institutes of Health, Bethesda, MD (USA))

1988-03-01

391

The molecular biology of human iron metabolism.  

PubMed

Iron is one of the most important nonorganic substances that make life possible. Iron plays major roles in oxygen transport (eg, hemoglobin; -67% of total body iron [TBI]), short-term oxygen storage (eg, myoglobin; -3.5% of TBI), and energy generation (eg, cytochromes; -3% of TBI). Iron also serves vital roles in various nonheme-containing enzymes (-2% of TBI). Figure 1 lists heme-containing and nonheme iron-containing proteins. TBI is controlled by the rate of iron absorption; there are no physiologic mechanisms to excrete excess iron. Iron deficiency has many adverse consequences, including anemia, and in children, behavioral and learning disorders. Iron excess is toxic to the body, harming the heart, liver, skin, pancreatic islet beta cells, bones, joints, and pituitary gland. Maintaining proper iron balance is essential for maintaining homeostasis and health. TBI in adults normally ranges between 3.5 and 5.0 g. A total of 75% of TBI is functional, and 25% is stored within cells as ferritin or hemosiderin. Ferritin contains 24 subunits of light chains (L chains; 19.7 kDa) and heavy chains (H chains; 21.1 kDa). The L chains are encoded on chromosome 19q13.33 and are 175 amino acids long. The H chains are encoded on chromosome 11q1 and are 183 amino acids long. Each ferritin molecule can contain as many as approximately 4500 ferric ions. Because the major role of iron is in hemoglobin synthesis, this review will focus on iron, iron transport, and hematopoiesis. PMID:24868988

Winter, William E; Bazydlo, Lindsay A L; Harris, Neil S

2014-01-01

392

Iron-Tolerant Cyanobacteria: Ecophysiology and Fingerprinting  

NASA Technical Reports Server (NTRS)

Although the iron-dependent physiology of marine and freshwater cyanobacterial strains has been the focus of extensive study, very few studies dedicated to the physiology and diversity of cyanobacteria inhabiting iron-depositing hot springs have been conducted. One of the few studies that have been conducted [B. Pierson, 1999] found that cyanobacterial members of iron depositing bacterial mat communities might increase the rate of iron oxidation in situ and that ferrous iron concentrations up to 1 mM significantly stimulated light dependent consumption of bicarbonate, suggesting a specific role for elevated iron in photosynthesis of cyanobacteria inhabiting iron-depositing hot springs. Our recent studies pertaining to the diversity and physiology of cyanobacteria populating iron-depositing hot springs in Great Yellowstone area (Western USA) indicated a number of different isolates exhibiting elevated tolerance to Fe(3+) (up to 1 mM). Moreover, stimulation of growth was observed with increased Fe(3+) (0.02-0.4 mM). Molecular fingerprinting of unialgal isolates revealed a new cyanobacterial genus and species Chroogloeocystis siderophila, an unicellular cyanobacterium with significant EPS sheath harboring colloidal Fe(3+) from iron enriched media. Our preliminary data suggest that some filamentous species of iron-tolerant cyanobacteria are capable of exocytosis of iron precipitated in cytoplasm. Prior to 2.4 Ga global oceans were likely significantly enriched in soluble iron [Lindsay et al, 2003], conditions which are not conducive to growth of most contemporary oxygenic cyanobacteria. Thus, iron-tolerant CB may have played important physiological and evolutionary roles in Earths history.

Brown, I. I.; Mummey, D.; Lindsey, J.; McKay, D. S.

2006-01-01

393

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

394

A comparison between the dislocation structure of ball-milled iron and copper as derived from the X-ray diffraction peak profile analyses  

NASA Astrophysics Data System (ADS)

X-ray diffraction line profile analyses were used for determination of the dislocation structure of ball-milled copper and iron samples. Plots of integral breadths of the diffraction line profiles in accordance with the classical Williamson-Hall equation clarified stronger strain anisotropy in iron than copper. By the analyses of the integral breadths in accordance with the modified Williamson-Hall equation, the relative fractions of edge and screw dislocations were determined. Prevailing dislocation structure of copper had edge character while those of iron showed mainly screw character.

Hosseini Nasab, F.; Hossein Nedjad, S.; Karimi, S.

2013-12-01

395

Theoretical analysis of iron-bore superconducting undulators  

SciTech Connect

The unavoidable undulator field errors due to machining tolerances of the yokes lead to a reduction of the gain in comparison with the case computed with an ideally perfect undulator. We describe a mathematical model of errors in iron-dominated micro-undulators introduced by manufacturing tolerances. Explicit expressions for the perturbation fields are derived. We use these fields to calculate the first, second and phase integrals describing the effects on the electron trajectory. We conclude that the intrinsic tolerances achievable with wire electric discharge machining do not significantly affect the performance of the Accelerator Test Facility free-electron laser. 9 refs., 6 figs.

Ben-Zvi, I.; Fernow, R.; Gallardo, J.; Ingold, G.; Sampson, W.; Woodle, M.

1991-01-01

396

Alveolar macrophages accumulate iron and ferritin after in vivo exposure to iron or tungsten dusts.  

PubMed

Extracellular iron present in alveolar structures may contribute to oxidative lung injury induced by toxic mineral dusts by enhancing dust-induced generation of hydroxyl radicals. Alveolar macrophages (AMs) can sequester iron within ferritin and limit generation of hydroxyl radicals. In the current study we sought to assess whether AMs accumulate iron and ferritin after in vivo exposure to a dust with high iron content, to iron oxide, or to an inflammatory dust, calcium tungstate. We performed lung lavage 1, 7, 14, 28, 42, and 56 days after intratracheal instillation of mineral dust in saline solution or instillation of saline solution alone and quantitated cell recovery and AM content of iron and ferritin. Instillation of iron oxide increased neutrophil recovery only on a day 1 when compared with results in controls, whereas calcium tungstate increased neutrophil recovery through day 14. AMs recovered after instillation of iron oxide contained increased amounts of iron and ferritin, beginning on day 1 and progressing through day 56 after treatment (7.57 +/- 0.38 microgram iron per 10(6) AMs vs 1.54 +/- 0.28 microgram iron per 10(6) AMs for controls, p < 0.001; and 5908 +/- 768 ng ferritin per 10(6) AMs vs 395 +/- 20 ng ferritin per 10(6) AMs, p < 0.001). AMs recovered after calcium tungstate instillation also contained increased amounts of iron and ferritin beginning 14 days after treatment, with greatest content 42 days after treatment (4.85 +/- 0.68 microgram iron per 10(6) AMs, p < 0.001, and 2274 +/- 736 ng ferritin per 10(6) AMs, p < 0.001). Tumor necrosis factor, which can enhance iron accumulation by macrophages, was spontaneously released by AMs recovered from tungsten-treated rats. These studies indicate that AMs accumulate iron and ferritin in response to both iron loading of the lungs with iron oxide exposure and lung inflammation induced by calcium tungstate exposure. PMID:8656043

Wesselius, L J; Smirnov, I M; Nelson, M E; O'Brien-Ladner, A R; Flowers, C H; Skikne, B S

1996-04-01

397

Effect of iron chelators on placental uptake and transfer of iron in rat  

SciTech Connect

The uptake of radiolabeled transferrin and iron by the rat placenta has been studied using two approaches. The first involved injection of a ferrous or ferric iron chelator followed by injection of label. Neither chelator decreased the amount of labelled transferrin in the placenta after 2-h incubation and only bipyridine, a ferrous iron chelator, inhibited iron transport to the fetus. Deferoxamine (DFO), a ferric iron chelator, had no effect on iron transport to the fetus but reduced iron uptake by the liver. Both bipyridine and DFO increased iron excretion into the gut and by the urinary tract to the same degree into the gut, but there was a 10-fold greater urinary excretion with bipyridine than with DFO. Injection of iron attached to the chelators showed that neither bipyridine nor DFO could donate iron to the fetus as efficiently as transferrin. The mechanism involved was further investigated by studying the effect of the chelators on uptake of transferrin-bound iron by placental cells in culture. DFO inhibited iron accumulation more effectively than bipyridine in the cultured cells. The effect was not due to a decrease in the cycling time of the receptor. The results can be explained if the iron is released from the transferrin in intracellular vesicles in the ferrous form, where it may be chelated by bipyridine and prevented from passing to the fetus or converted to the ferric form once it is inside the cell matrix.

Wong, C.T.; McArdle, H.J.; Morgan, E.H.

1987-05-01

398

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

399

Deciphering Fur transcriptional regulatory network highlights its complex role beyond iron metabolism in Escherichia coli  

PubMed Central

The ferric uptake regulator (Fur) plays a critical role in the transcriptional regulation of iron metabolism. However, the full regulatory potential of Fur remains undefined. Here we comprehensively reconstruct the Fur transcriptional regulatory network in Escherichia coli K-12 MG1655 in response to iron availability using genome-wide measurements (ChIP-exo and RNA-seq). Integrative data analysis reveals that a total of 81 genes in 42 transcription units are directly regulated by three different modes of Fur regulation, including apo- and holo-Fur activation and holo-Fur repression. We show that Fur connects iron transport and utilization enzymes with negative-feedback loop pairs for iron homeostasis. In addition, direct involvement of Fur in the regulation of DNA synthesis, energy metabolism, and biofilm development is found. These results show how Fur exhibits a comprehensive regulatory role affecting many fundamental cellular processes linked to iron metabolism in order to coordinate the overall response of E. coli to iron availability. PMID:25222563

Seo, Sang Woo; Kim, Donghyuk; Latif, Haythem; O’Brien, Edward J.; Szubin, Richard; Palsson, Bernhard O.

2014-01-01

400

Industry experience in promoting weekly iron-folic acid supplementation in the Philippines.  

PubMed

After participating in a pilot project under a government-industry partnership to promote the adoption of weekly iron-folic acid supplementation among women of reproductive age in the Philippines in 1998, United Laboratories (UNILAB), the Philippines' largest private pharmaceutical company, decided in April 2002 to launch a weekly iron-folic acid supplement for pregnant and non-pregnant women under the brand name Femina. The business objective set for the Femina brand was to build the category of preventive iron-folic acid supplements in line with the Philippine Department of Health's advocacy on weekly supplementation as an alternate to daily dosing to reduce the prevalence of anemia in the country. The brand was supported with an integrated mix of traditional advertising media with complementary direct-to-consumer educational programs that aimed to create awareness of iron-deficiency anemia, its causes and effects, and the role of weekly intake of iron-folic acid in preventing the condition. Aggressive marketing support for 1 year was successful in creating awareness among the target women. Significant lessons derived from consumers identified opportunity areas that can be further addressed in developing advocacy programs on weekly iron supplementation implemented on a nationwide scale in the future. PMID:16466091

Garcia, Josel; Datol-Barrett, Eva; Dizon, Maynilad

2005-12-01

401

Bioavailability of iron bis-glycinate chelate in water.  

PubMed

Iron amino acid chelate is being increasingly considered in programs for iron fortification of foods. The bioavailability of iron bis-glycinate chelate given in water was studied using a double-isotopic method in a group of 14 women. Iron absorption from aqueous solutions of 15 mg/L of elemental iron as either iron bis-glycine chelate or ferrous ascorbate was not significantly different (34.6% and 29.9% respectively). Standardized iron absorption of the iron bis-glycinate was 46.3% (standardized to 40% absorption of the reference dose). There was a significant correlations between (ln) iron absorption of iron bis-glycinate chelate with (ln) serum ferritin (r = -0.60, p < 0.03) and with (ln) iron absorption from ferrous ascorbate (r = 0.71, p < 0.006), suggesting that iron bis-glycinate chelate absorption is indeed regulated by the iron stores of the body. PMID:11688077

Olivares, M; Pizarro, F

2001-03-01

402

Modelling Iron-Bentonite Interactions  

NASA Astrophysics Data System (ADS)

The presence of both iron canisters and bentonitic clay in some engineered barrier system (EBS) designs for the geological disposal of high-level radioactive wastes creates the potential for chemical interactions which may impact upon the long-term performance of the clay as a barrier to radionuclide migration. Flooding of potential radionuclide sorption sites on the clay by ferrous ions and conversion of clay to non-swelling sheet silicates (e.g. berthierine) are two possible outcomes deleterious to long-term performance. Laboratory experimental studies of the corrosion of iron in clay show that corrosion product layers are generally thin (< 1 µm) with magnetite, siderite, or ‘green rust' occurring depending upon temperature and ambient partial pressure of carbon dioxide. In theory, incorporation of iron into clay alteration products could act as a ‘pump' to accelerate corrosion. However, the results of laboratory experiments to characterise the products of iron-bentonite interaction are less than unequivocal. The type and amounts of solid products appear to be strong functions of time, temperature, water/clay ratio, and clay and pore fluid compositions. For example, the products of high temperature experiments (> 250 °C) are dominated by chlorite, whereas lower temperatures produce berthierine, odinite, cronstedtite, or Fe-rich smectite. Unfortunately, the inevitable short-term nature of laboratory experimental studies introduces issues of metastability and kinetics. The sequential formation in time of minerals in natural systems often produces the formation of phases not predicted by equilibrium thermodynamics. Evidence from analogous natural systems suggests that the sequence of alteration of clay by Fe-rich fluids will proceed via an Ostwald step sequence. The computer code, QPAC, has been modified to incorporate processes of nucleation, growth, precursor cannibalisation, and Ostwald ripening to address the issues of the slow growth of bentonite alteration products. This, together with inclusion of processes of iron corrosion and diffusion, has enabled investigation of a representative model of the alteration of bentonite in a typical EBS environment. Simulations with fixed mineral surface areas show that berthierine dominates the solid product assemblage, with siderite replacing it at simulation times greater than 10 000 years. Simulations with time-dependent mineral surface areas show a sequence of solid alteration products, described by: magnetite -> cronstedtite -> berthierine -> chlorite. Using plausible estimates of mineral-fluid interfacial free energies, chlorite growth is not achieved until 5 000 years of simulation time. The results of this modelling work suggest that greater emphasis should be placed upon methods to up-scale the results of laboratory experiments to timescales of relevance to performance assessment.

Watson, C.; Savage, D.; Benbow, S.; Wilson, J.

2009-04-01

403

Iron speciation and its biological availability in seawater: A workshop  

SciTech Connect

This workshop brought together marine chemists with expertise in iron chemistry and biologists with expertise in the role of iron in phytoplankton production to discuss controversies regarding the role of iron in oceanic primary productivity and global climatic change. A new paradigm for marine iron biogeochemistry was generated. The five major new items within this paradigm included (1) the nature of iron inputs to the sea, (2) chemical speciation of iron in seawater, (3) relationships between iron chemistry and marine microbial community dynamics, (4) adaptations of marine microbes to iron input, and (5) ecological and biogeochemical implications of changes in iron supply to the sea.

Wells, M.L.; Bruland, K.W.

1995-09-08

404

Iron overload thalassemic cardiomyopathy: Iron status assessment and mechanisms of mechanical and electrical disturbance due to iron toxicity  

PubMed Central

Patients with thalassemia major have inevitably suffered from complications of the disease, due to iron overload. Among such complications, cardiomyopathy is the leading cause of morbidity and mortality (63.6% to 71%). The major causes of death in this group of patients are congestive heart failure and fatal cardiac tachyarrhythmias leading to sudden cardiac death. The free radical-mediated pathway is the principal mechanism of iron toxicity. The consequent series of events caused by iron overload lead to catastrophic cardiac effects. The authors review the electrophysiological and molecular mechanisms, pathophysiology and correlated clinical insight of heart failure and arrhythmias in iron overload thalassemic cardiomyopathy. PMID:19340344

Lekawanvijit, Suree; Chattipakorn, Nipon

2009-01-01

405

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

406

Spin-Lattice Dynamics Simulations of Ferromagnetic Iron  

NASA Astrophysics Data System (ADS)

We develop a Spin-Lattice Dynamics (SLD) simulation model for ferromagnetic iron where atoms are treated as classical particles with spins. The atoms interact via many-body forces as well as via spin-orientation-dependent forces of the Heisenberg form. The coupling between the lattice and the spin degrees of freedom is described by a coordinate-dependent exchange function. An algorithm for integrating the spin-lattice dynamics equations of motion is based on the 2nd order Suzuki-Trotter decomposition for the non-commuting Liouville evolution operators for atomic coordinates and spins. The notions of the spin thermostat and the spin temperature are introduced through a combined application of the Langevin spin dynamics and the fiuctuation-dissipation theorem. Several applications of the new method described in the paper illustrate the significant effect of the spin degrees of freedom on the dynamics of atomic motion in iron and iron-based alloys, and confirm that the Spin-Lattice Dynamics approach provides a viable framework for performing realistic large-scale simulations of magnetic materials.

Ma, Pui-Wai; Woo, C. H.; Dudarev, S. L.

2008-04-01

407

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

408

Solid Iron Compressed Up to 560 GPa  

NASA Astrophysics Data System (ADS)

Dynamic compression by multiple shocks is used to compress iron up to 560 GPa (5.6 Mbar), the highest solid-state pressure yet attained for iron in the laboratory. Extended x-ray absorption fine structure (EXAFS) spectroscopy offers simultaneous density, temperature, and local-structure measurements for the compressed iron. The data show that the close-packed structure of iron is stable up to 560 GPa, the temperature at peak compression is significantly higher than expected from pure compressive work, and the dynamic strength of iron is many times greater than the static strength based on lower pressure data. The results provide the first constraint on the melting line of iron above 400 GPa.

Ping, Y.; Coppari, F.; Hicks, D. G.; Yaakobi, B.; Fratanduono, D. E.; Hamel, S.; Eggert, J. H.; Rygg, J. R.; Smith, R. F.; Swift, D. C.; Braun, D. G.; Boehly, T. R.; Collins, G. W.

2013-08-01

409

Bleomycin-detectable iron in brain tissue.  

PubMed

The normal brain contains regions with high concentrations of iron, part of which appears to be in a low molecular mass chelatable form. Iron complexes with a molecular mass of below 10,000, were measured in ultrafiltrates of homogenized gerbil brains using the bleomycin assay, and were found to average 20.5 +/- 3.5 microM (n = 8). As expected, no bleomycin detectable iron was found in the plasma of these animals. No obvious difference in the tissue levels of bleomycin-detectable iron was recorded following ischaemia and reperfusion. This is probably due to the already abundant presence of iron in the brain and the likely release of iron from protected sites due to structural damage inherent in the preparative procedures used. PMID:1712743

Gutteridge, J M; Cao, W; Chevion, M

1991-01-01

410

A screening test for assessing iron status.  

PubMed

Intervention strategies to combat iron deficiency anemia in developing countries may hasten the development of iron overload in patients with an inherited defect in hemoglobin synthesis. This risk could be diminished if there was a rapid and simple method available for detecting iron overload in population screening programs. We have developed such a method, which is in effect a semiquantitative ferritin measurement based on a modification of a two-site enzyme-linked immunoassay. The assay requires only 2 drops of whole blood and a total incubation time of 90 min. The procedure, which can readily distinguish iron deficiency from even a modest increase in storage iron, has a potentially wide application in settings where a prompt assessment of iron status is required. PMID:7032625

Pintar, J; Skikne, B S; Cook, J D

1982-01-01

411

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

412

Prevention of Iron Deficiency in Infancy, Childhood and Adolescence  

Microsoft Academic Search

Iron deficiency (ID) is prevalent in infants, children and adolescents worldwide due to their high iron requirements during growth, low dietary iron intake and low-bioavailability diet. Low iron status is associated with adverse health consequences throughout childhood. Prevention measures should be initiated early and include iron supplementation of pregnant women, delayed cord clamping at delivery and exclusive breast-feeding for 6

Maria Andersson; Richard F. Hurrell

2010-01-01

413

Pathophysiology and evaluation of iron overload in various disease states  

Microsoft Academic Search

Iron overload can result from increased iron absorption or from repeated blood transfusions. Primary iron overload is associated with genetic factors that boost iron absorption, such as hereditary haemochromatosis, while secondary iron overload results from chronic blood transfusions that are used to treat anaemia in conditions such as thalassaemia, sickle cell disease (SCD), and myelodysplastic syndromes (MDS). The consequences of

John B. Porter

414

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

415

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

416

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

417

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

418

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

419

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

Code of Federal Regulations, 2014 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...

2014-10-01

420

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

421

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

Code of Federal Regulations, 2014 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...

2014-10-01

422

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

423

Ferrous versus Ferric Oral Iron Formulations for the Treatment of Iron Deficiency: A Clinical Overview  

PubMed Central

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

424

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

425

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

426

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

427

Iron filings as magnetically retrievable markers  

Microsoft Academic Search

Iron filings (plain, red-painted and red-fluorescent-painted) in tallow baits were tested as bait acceptance markers for coyotes (Canis latrans). The paint coatings did not survive digestive passage. Based on very small numbers of treated animals, recovery period of iron filings appeared longer than for two types of particle markers examined by others. Iron filings would be simple to use, readily

R. D. Nass

1995-01-01

428

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

429

High toughness-high strength iron alloy  

NASA Technical Reports Server (NTRS)

An iron alloy is provided which exhibits strength and toughness characteristics at cryogenic temperatures. The alloy consists essentially of about 10 to 16 percent by weight nickel, about 0.1 to 1.0 percent by weight aluminum, and 0 to about 3 percent by weight copper, with the balance being essentially iron. The iron alloy is produced by a process which includes cold rolling at room temperature and subsequent heat treatment.

Stephens, J. R.; Witzke, W. R. (inventors)

1980-01-01

430

Directional Solidification of Nodular Cast Iron  

NASA Technical Reports Server (NTRS)

Cerium enhances formation of graphite nodules. Preliminary experiments in directional solidification of cast iron shows quantitative correlation of graphite microstructure with growth rate and thermal gradient, with sufficient spheroidizing element to form spheroidal graphite under proper thermal conditions. Experimental approach enables use of directional solidification to study solidification of spheriodal-graphite cast iron in low gravity. Possible to form new structural materials from nodular cast iron.

Curreri, P. A.; Stefanescu, D. M.; Hendrix, J. C.

1987-01-01

431

The Iron Abundance of IOTA Herculis From Ultraviolet Iron Lines  

NASA Astrophysics Data System (ADS)

We have obtained (Adelman 1992, 1993, private comunication) coadded, high-resolution IUE spectra of Iota Herculis (B3 IV) in both short wavelength (SWP) and long wavelength (LWP) regions. The spectra span the ultraviolet spectrum from 110 - 300 nm and have a SNR of roughly 30 -50; they are described in Adelman et. al. (1993, ApJ 419, 276). Abundance indicators were 54 lines of Fe II and 26 lines of Fe III whose atomic parameters have been measured in the laboratory. LTE synthetic spectra for comparison with observations were produced with the Kurucz model atmosphere and spectral synthesis codes ATLAS9/SYNTHE (Kurucz 1979, ApJS 40,1; Kurucz and Avrett 1981, SAO Special Report 391). Model parameters were chosen from the literature: effective temperature = 17500 K, log g =3.75, v sin i= 11 km/s, and turbulent velocity = 0 km/s. (Peters and Polidan 1985, in IAU Symposium 111, ed. D. S. Hayes et al. (Dordrecht: Reidel), 417). We determined the equivalent widths of the chosen lines by fitting gaussian profiles to the lines and by measuring the equivalent widths of the gaussians. We derived abundances by fitting a straight line to a plot of observed equivalent widths vs. synthetic equivalent widths; we adjusted the iron abundance of the models until a slope of unity was achieved. The abundances derived from the different ionization stages are in agreement: Fe II lines indicate an iron abundance that is 34 +15/-10% the solar value([Fe/H]=-0.47 +0.16-0.15dex), while from Fe III lines we obtain 34 +/- 10% ([Fe/H]=-0.47 +0.11/-0.15 dex). A search of the literature suggests that no previous investigations of this star's iron abundance have found agreement between the different ionization stages. We thank Saul Adelman for his generous assistance, and the Faculty Research Fund Board of Wittenberg University for support of this research.

Grigsby, J.; Mulliss, C.; Baer, G.

1995-03-01

432

Changes in Serum Lipid Concentrations during Iron Depletion and after Iron Supplementation  

Microsoft Academic Search

To investigate the effects of body iron depletion and iron supplementation on serum lipid concentrations, hematologic indices, iron markers, and serum lipid profiles were measured in 427 girls, age 14- 19 yr. There were no significant differences in serum lipid concentrations between subjects with moderate iron deficiency anemia (blood Hb <12.0 g\\/dL) and healthy controls. However, serum total cholesterol concentration

Jong Weon Choi; Soon Ki Kim; Soo Hwan Pai

2001-01-01

433

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

434

Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren  

PubMed Central

The effect of iron fortification is generally assumed to be less than iron supplementation; however, the magnitude of difference in effects is not known. The present study aims to compare the efficacy of these two strategies on anaemia and iron status. After screening on low Hb, 425 anaemic children in six primary schools in Tam Nong district of Phu Tho province were included in a randomized, placebo-controlled trial comparing two groups receiving iron fortified instant noodles or iron supplementation for 6 months and a control group, with children in all groups having been dewormed. Blood samples were collected before and after intervention for haemoglobin, serum ferritin (SF), serum transferrin receptor (TfR), C-reactive protein (CRP), and haemoglobinopathies analysis. Regression analysis was used to assess the effect of iron fortification and iron supplementation on haemoglobin concentration, SF, TfR, body iron, and anaemic status as outcome variables. The improvement of haemoglobin, SF, and body iron level in the group receiving iron fortification was 42% (2.6 g/L versus 6.2 g/L), 20% (23.5 ?g/L versus 117.3 ?g/L), and 31.3% (1.4 mg/kg versus 4.4 mg/kg) of that in the iron supplementation group. The prevalence of anaemia dropped to 15.1% in the control group, with an additional reduction of anaemia of 8.5% in the iron supplementation group. The additional reduction due to iron fortification was 5.4%, which amounts to well over 50% of the impact of supplementation. In conclusion, the efficacy of iron fortification based on reduction of prevalence of anaemia, and on the change in haemoglobin level, is about half of the maximum impact of supplementation in case of optimal compliance. Thus, in a population of anaemic children with mild iron deficiency, iron fortification should be the preferred strategy to combat anaemia. PMID:17147795

Thi Le, Huong; Brouwer, Inge D; Burema, Jan; Nguyen, Khan Cong; Kok, Frans J

2006-01-01

435

Crystallographic Orientation and Oxidation of Submicron Whiskers of Iron, Iron—Cobalt, and Cobalt  

Microsoft Academic Search

Individual single-crystal iron, iron—cobalt, and cobalt whiskers with diameters from 250 to 7000 Å have been studied by selected area electron diffraction. All of the iron and iron—cobalt diffraction patterns showed a normal bcc structure with the ?100? direction along the long axis of the whisker. All but one of the cobalt whiskers were hexagonal with the ?11.0? along the

F. E. Luborsky; E. F. Koch; C. R. Morelock

1963-01-01

436

Deferasirox removes cardiac iron and attenuates oxidative stress in the iron-overloaded gerbil.  

PubMed

Iron-induced cardiovascular disease is the leading cause of death in iron-overloaded patients. Deferasirox is a novel, once daily oral iron chelator that was recently approved for the treatment of transfusional iron overload. Here, we investigate whether deferasirox is capable of removing cardiac iron and improving iron-induced pathogenesis of the heart using the iron overload gerbil model. Animals were randomly divided into three groups: control, iron overload, and iron overload + deferasirox treatment. Iron-dextran was given 100 mg/kg per 5 days i.p for 10 weeks. Deferasirox treatment was taken post iron loading and was given at 100 mg/kg/day p.o for 1 or 3 months. Cardiac iron concentration was determined by inductively coupled plasma atomic emission spectroscopy. Compared with the untreated group, deferasirox treatment for 1 and 3 months decreased cardiac iron concentration 17.1% (P = 0.159) and 23.5% (P < 0.05), respectively. These treatment-associated reductions in cardiac iron were paralleled by decreases in tissue ferritin expression of 20% and 38% at 1 and 3 months, respectively (P < 0.05). Using oxyblot analysis and hydroethidine fluorescence, we showed that deferasirox significantly reduces cardiac protein oxidation and superoxide abundance by 36 and 47.1%, respectively (P < 0.05). Iron-induced increase in oxidative stress was also associated with increased phosphorylation of ERK-, p38-, and JNK-mitogen-activated protein kinase (MAPK). Interestingly, deferasirox treatment significantly diminished the phosphorylation of all three MAPK subfamilies. These results suggest that deferasirox may confer a cardioprotective effect against iron induced injury. PMID:19650117

Al-Rousan, Rabaa M; Paturi, Satyanarayana; Laurino, Joseph P; Kakarla, Sunil K; Gutta, Anil K; Walker, Ernest M; Blough, Eric R

2009-09-01

437

Microbial oxidation of ferrous iron in acid mine water at sulfur and iron-sulfide mine  

Microsoft Academic Search

The microbial oxidation of ferrous iron in the acid mine water from the abandoned Matsuo sulfur and iron-sulfide mine area was investigated. The acid mine water had an extremely low pH value and contained a high concentration of ferrous iron (about 1,000 ppm). The ferrous iron was oxidized rapidly to the ferric form in the acid mine water. The oxidation

Norio Wakao; Yonekichi Sakurai; Hideo Shiota

1977-01-01

438

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

439

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

440

Diagnosis and management of iron deficiency anemia.  

PubMed

Iron deficiency anemia (IDA) is a common hematologic condition, affecting a substantial proportion of the world's women and young children. Optimal management of IDA requires an accurate diagnosis, identification and correction of the underlying cause, provision of medicinal iron therapy, and confirmation of treatment success. There are limited data to support current treatment approaches regarding oral iron preparation, dosing, monitoring, and duration of therapy. New intravenous iron agents have improved safety profiles, which may foster their increased utilization in the treatment of patients with IDA. Clinical trials focused on improving current treatment standards for IDA are sorely needed. PMID:25064710

Powers, Jacquelyn M; Buchanan, George R

2014-08-01

441

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

442

Hepatocellular carcinoma and African iron overload.  

PubMed Central

Both hepatocellular carcinoma (HCC) and iron overload are important health problems in Africa. Chronic hepatitis B virus (HBV) infection is recognised as a major risk factor for HCC, but iron overload in Africans has not been considered in pathogenesis. Up to half the patients with HCC in Africa do not have any recognised risk factors such as preceding chronic HBV infection, and other risk factors remain unidentified. HCC is an important complication of HLA-linked haemochromatosis, an iron loading disorder found in Europeans. It is proposed that African iron overload might also be a risk factor for HCC. PMID:8549953

Gangaidzo, I T; Gordeuk, V R

1995-01-01

443

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

444

Mineral Migration and Influence of Meal Preparation in Iron Cookware on the Iron Nutritional Status of Vegetarian Students  

Microsoft Academic Search

This study evaluates iron and manganese migration from iron pans and the impact of routine meal preparation on the iron status of vegetarians. Rice and tomato sauce were cooked in iron pans. Fe and Mn quantification were done by inductively coupled plasma optical emission spectrometry. Vegetarians had their meals prepared in cast-iron cookware for 12 weeks. Tomato sauce took up

Késia Diego Quintaes; Jaime Amaya-Farfan; Fernanda Mariana Tomazini; Marcelo Antonio Morgano; Niurka Maritza de Almeyda Hajisa; José Trezza Neto

2007-01-01

445

Reactive Iron and Iron-Reducing Bacteria in Louisiana Continental Shelf Sediments  

EPA Science Inventory

The Mississippi and Atchafalaya Rivers release sediments containing 15 x 106 t of iron onto the Louisiana continental shelf (LCS) each year. Iron oxides reaching the seafloor may be utilized as electron acceptors by iron-reducing bacteria for organic matter oxidation or become r...

446

Serum bleomycin-detectable iron in patients with thalassemia major with normal range of serum iron.  

PubMed

"Free" iron, a potentially radical-generating low mass iron, and not found in normal human blood, was increased in the serum of blood-transfused thalassemia major patients seen in the Yangon General Hospital, Yangon, Myanmar (Burma). The low mass iron was detected by the bleomycin assay. Fifty-one blood samples were analyzed (from 28 males and 23 females). High "free" iron was detected in 47 sera samples from thalassemia patients. Serum ferritin, which reflects the body store iron, was higher than the normal range (10-200 ng/ml) in 49 patients. On the other hand, serum iron of 39 sera samples fell within the normal range (50-150 micrograms/dl). Four were less than 50 micrograms/dl and eight were more than 150 micrograms/dl. Almost all the patients' sera of normal or higher serum iron level contained "free" iron. Thus, almost all the sera from thalassemic patients from Myanmar contain bleomycin-detectable iron, even when serum iron is within the normal range. In developing countries where undernutrition is prevalent (serum albumin in these patients was 3.6 +/- 0.4 g/dl, P < 0.0001 vs. control value of 4.0 - 4.8 g/dl), normal serum iron does not preclude the presence of free iron in the serum. PMID:7545860

Han, K E; Okada, S

1995-06-01

447

IRON "BIOFORTIFICATION" OF TROPICAL MAIZE TO REDUCE HUMAN IRON DEFFICIENCY IN WEST AFRICA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron deficiency is estimated to affect over one-half the world population. Improving the nutritional quality of staple food crops by the development of genotypes with high bioavailable iron represents a sustainable and cost effective approach to alleviating iron malnutrition. Forty-nine elite late m...

448

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

449

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

450

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

451

Absorption of Iron from Ferritin Is Independent of Heme Iron and Ferrous Salts in Women and Rat Intestinal Segments123  

PubMed Central

Ferritin iron from food is readily bioavailable to humans and has the potential for treating iron deficiency. Whether ferritin iron absorption is mechanistically different from iron absorption from small iron complexes/salts remains controversial. Here, we studied iron absorption (RBC 59Fe) from radiolabeled ferritin iron (0.5 mg) in healthy women with or without non-ferritin iron competitors, ferrous sulfate, or hemoglobin. A 9-fold excess of non-ferritin iron competitor had no significant effect on ferritin iron absorption. Larger amounts of iron (50 mg and a 99-fold excess of either competitor) inhibited iron absorption. To measure transport rates of iron that was absorbed inside ferritin, rat intestinal segments ex vivo were perfused with radiolabeled ferritin and compared to perfusion with ferric nitrilotriacetic (Fe-NTA), a well-studied form of chelated iron. Intestinal transport of iron absorbed inside exogenous ferritin was 14.8% of the rate measured for iron absorbed from chelated iron. In the steady state, endogenous enterocyte ferritin contained >90% of the iron absorbed from Fe-NTA or ferritin. We found that ferritin is a slow release source of iron, readily available to humans or animals, based on RBC iron incorporation. Ferritin iron is absorbed by a different mechanism than iron salts/chelates or heme iron. Recognition of a second, nonheme iron absorption process, ferritin endocytosis, emphasizes the need for more mechanistic studies on ferritin iron absorption and highlights the potential of ferritin present in foods such as legumes to contribute to solutions for global iron deficiency. PMID:22259191

Chen, Huijun; Miranda, Constanza; Janser, Heinz; Elsenhans, Bernd; Núñez, Marco T.; Pizarro, Fernando; Schümann, Klaus

2012-01-01

452

Synthesis of iron fertilization experiments: From the Iron Age in the Age of Enlightenment  

NASA Astrophysics Data System (ADS)

Comparison of eight iron experiments shows that maximum Chl a, the maximum DIC removal, and the overall DIC/Fe efficiency all scale inversely with depth of the wind mixed layer (WML) defining the light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, and grazing play additional roles. The Southern Ocean experiments were most influenced by very deep WMLs. In contrast, light conditions were most favorable during SEEDS and SERIES as well as during IronEx-2. The two extreme experiments, EisenEx and SEEDS, can be linked via EisenEx bottle incubations with shallower simulated WML depth. Large diatoms always benefit the most from Fe addition, where a remarkably small group of thriving diatom species is dominated by universal response of Pseudo-nitzschia spp. Significant response of these moderate (10-30 ?m), medium (30-60 ?m), and large (>60 ?m) diatoms is consistent with growth physiology determined for single species in natural seawater. The minimum level of "dissolved" Fe (filtrate < 0.2 ?m) maintained during an experiment determines the dominant diatom size class. However, this is further complicated by continuous transfer of original truly dissolved reduced Fe(II) into the colloidal pool, which may constitute some 75% of the "dissolved" pool. Depth integration of carbon inventory changes partly compensates the adverse effects of a deep WML due to its greater integration depths, decreasing the differences in responses between the eight experiments. About half of depth-integrated overall primary productivity is reflected in a decrease of DIC. The overall C/Fe efficiency of DIC uptake is DIC/Fe ˜ 5600 for all eight experiments. The increase of particulate organic carbon is about a quarter of the primary production, suggesting food web losses for the other three quarters. Replenishment of DIC by air/sea exchange tends to be a minor few percent of primary CO2 fixation but will continue well after observations have stopped. Export of carbon into deeper waters is difficult to assess and is until now firmly proven and quite modest in only two experiments.

de Baar, Hein J. W.; Boyd, Philip W.; Coale, Kenneth H.; Landry, Michael R.; Tsuda, Atsushi; Assmy, Philipp; Bakker, Dorothee C. E.; Bozec, Yann; Barber, Richard T.; Brzezinski, Mark A.; Buesseler, Ken O.; Boyé, Marie; Croot, Peter L.; Gervais, Frank; Gorbunov, Maxim Y.; Harrison, Paul J.; Hiscock, William T.; Laan, Patrick; Lancelot, Christiane; Law, Cliff S.; Levasseur, Maurice; Marchetti, Adrian; Millero, Frank J.; Nishioka, Jun; Nojiri, Yukihiro; van Oijen, Tim; Riebesell, Ulf; Rijkenberg, Micha J. A.; Saito, Hiroaki; Takeda, Shigenobu; Timmermans, Klaas R.; Veldhuis, Marcel J. W.; Waite, Anya M.; Wong, Chi-Shing

2005-09-01

453

Iron mobilization in North African dust.  

SciTech Connect

Iron is an essential nutrient for phytoplankton. Although iron-containing dust mobilized from arid regions supplies the majority of the iron to the oceans, the key flux in terms of the biogeochemical response to atmospheric deposition is the amount of soluble or bioavailable iron. Atmospheric processing of mineral aerosols by anthropogenic pollutants (e.g. sulfuric acid) may transform insoluble iron into soluble forms. Previous studies have suggested higher iron solubility in smaller particles, as they are subject to more thorough atmospheric processing due to a longer residence time than coarse particles. On the other hand, the specific mineralogy of iron in dust may also influence the particulate iron solubility in size. Compared to mineral dust aerosols, iron from combustion sources could be more soluble, and found more frequently in smaller particles. Internal mixing of alkaline dust with iron-containing minerals could significantly reduce iron dissolution in large dust aerosols due to the buffering effect, which may, in contrast, yield higher solubility in smaller particles externally mixed with alkaline dust (Ito and Feng, 2010). Here, we extend the modeling study of Ito and Feng (2010) to investigate atmospheric processing of mineral aerosols from African dust. In contrast to Asian dust, we used a slower dissolution rate for African dust in the fine mode. We compare simulated fractional iron solubility with observations. The inclusion of alkaline compounds in aqueous chemistry substantially limits the iron dissolution during long-range transport to the Atlantic Ocean: only a small fraction of iron (<0.2%) dissolves from illite in coarsemode dust aerosols with 0.45% soluble iron initially. In contrast, a significant fraction (1-1.5%) dissolves in fine-mode dust aerosols due to the acid mobilization of the iron-containing minerals externally mixed with carbonate minerals. Consequently, the model generally reproduces higher iron solubility in smaller particles as suggested by measurements over the Atlantic Ocean. Our results imply that the dissolution of iron in African dust is generally slower than that in Asian dust. Conventionally, dust is assumed as the major supply of bioavailable iron with a constant solubility at 1-2% to the remote ocean. Therefore, the timing and location of the atmospheric iron input to the ocean with detailed modeling of atmospheric processing could be different from those previously assumed. Past and future changes in aerosol supply of bioavailable iron might play a greater role in the nutrient supply for phytoplankton production in the upper ocean, as global warming has been predicted to intensify stratification and reduce vertical mixing from the deep ocean. Thus the feedback of climate change through ocean uptake of carbon dioxide as well as via aerosol-cloud interaction might be modified by the inclusion of iron chemistry in the atmosphere.

Ito, A.; Feng, Y. (Environmental Science Division); (Research Inst. for Global Change)

2011-01-01

454

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