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Sample records for magnitogorsk integrated iron

  1. Coke oven gas treatment and by-product plant of Magnitogorsk Integrated Iron and Steel Works

    SciTech Connect

    Egorov, V.N.; Anikin, G.J.; Gross, M.

    1995-12-01

    Magnitogorsk Integrated Iron and Steel Works, Russia, decided to erect a new coke oven gas treatment and by-product plant to replace the existing obsolete units and to improve the environmental conditions of the area. The paper deals with the technological concept and the design requirements. Commissioning is scheduled at the beginning of 1996. The paper describes H{sub 2}S and NH{sub 3} removal, sulfur recovery and ammonia destruction, primary gas cooling and electrostatic tar precipitation, and the distributed control system that will be installed.

  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)

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

    2010-06-01

    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.

  3. [Factors of anxiety and autonomic tonus in senior preschool children from Magnitogorsk].

    PubMed

    Ingel', F I; Stepanova, A A; Stepanova, O P; Legostaeva, T B; Koganova, Z I; Kozlova, O B

    2013-01-01

    In the paper there are presented the results of a study of anxiety and balance ofparts of autonomous nervous system in healthy children 5-7 years old, residing in different parts of Magnitogorsk. It is shown that state of heightened and high alert was shown to be more common among children living on the left bank of the Urals river around the Magnitogorsk Metallurgical Integrated Plant. In these children an imbalance in the work of the parts of the autonomic nervous system was detected more frequently, at that shifts were observed mainly in the direction to ergotropic tone. At the same time balanced work of the parts of the autonomic nervous system was observed more frequently in children living on the right bank of the Urals river. Discovered psychosomatic features of examined children turned out to be associated with both the social characteristics of family lifestyle and the emotional stress of parents, and the contents of some organic compounds in total snow samples collected in the territories of kindergartens which they attended. One ofthe most significant results ofthe work we consider the detection of a correlation relationship between emotional stress of parents and activity of key enzymes in their children, reflecting the protective and adaptive reactions of the organism. On the basis of these and previously obtained data, we suggest that social and psychological factors of the family are not only a potential source of maladaptation of the child, but, probably, can have an impact on the stability and sensitivity of the genome of children.

  4. New comprehensive indices for evaluating the quality of pitch and the principles of classification of pitches. [Magnitogorsk Integrated Iron and Steel Works-USSR

    SciTech Connect

    Gaisarov, M.G.; Mochalov, V.V.

    1981-01-01

    An attempt was made to select the minimum necessary number of indices by which may be evaluated the technological properties of pitch as a binder. These parameters include mutually correlated quantities, reflecting either the degree of condensation of the pitch (the content of the high-molecular fractions, the density, the coke cake yield, volatile matter yield, distillate to 360/sup 0/C, carbon-hydrogen ratio) or its rheological properties (viscosity, softening point). Using these criteria, statistical analysis was used to analyze the composition functions of coke-forming and plasticizing properties for ca 20 specimens from various plants with softening points of 65 to 90/sup 0/C. The results of the computations indicate that the relationship between the properties and composition in each group is significant and approaches the functional. The proposed pitch classification system is only a basis for discussion and requires refinement. 3 tables.

  5. Environmental-Toxicological Characteristics of Waters and Their Sources at Magnitogorsk With the Its Iron and Steel Industry

    NASA Astrophysics Data System (ADS)

    Koshkina, V. S.; Serova, A. A.; Timofeev, V. Yu

    2016-08-01

    This study summarizes the information necessary to characterize and assess the quality of drinking and industrial water supply in industrial centers with metallurgical engineering and provides information about the pollution impact on the natural environment. The study shows the influence of air pollution, of the soil pollution on the environment of water objects; it also demonstrates the role of the quality of water supply for establishing a higher risk of health problems for children.

  6. A novel streptococcal integrative conjugative element involved in iron acquisition

    PubMed Central

    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

    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

  7. Integrated modeling and heat treatment simulation of austempered ductile iron

    NASA Astrophysics Data System (ADS)

    Hepp, E.; Hurevich, V.; Schäfer, W.

    2012-07-01

    The integrated modeling and simulation of the casting and heat treatment processes for producing austempered ductile iron (ADI) castings is presented. The focus is on describing different models to simulate the austenitization, quenching and austempering steps during ADI heat treatment. The starting point for the heat treatment simulation is the simulated microstructure after solidification and cooling. The austenitization model considers the transformation of the initial ferrite-pearlite matrix into austenite as well as the dissolution of graphite in austenite to attain a uniform carbon distribution. The quenching model is based on measured CCT diagrams. Measurements have been carried out to obtain these diagrams for different alloys with varying Cu, Ni and Mo contents. The austempering model includes nucleation and growth kinetics of the ADI matrix. The model of ADI nucleation is based on experimental measurements made for varied Cu, Ni, Mo contents and austempering temperatures. The ADI kinetic model uses a diffusion controlled approach to model the growth. The models have been integrated in a tool for casting process simulation. Results are shown for the optimization of the heat treatment process of a planetary carrier casting.

  8. Quantifying Integrated Proteomic Responses to Iron Stress in the Globally Important Marine Diazotroph Trichodesmium

    PubMed Central

    Snow, Joseph T.; Polyviou, Despo; Skipp, Paul; Chrismas, Nathan A. M.; Hitchcock, Andrew; Geider, Richard; Moore, C. Mark; Bibby, Thomas S.

    2015-01-01

    Trichodesmium is a biogeochemically important marine cyanobacterium, responsible for a significant proportion of the annual ‘new’ nitrogen introduced into the global ocean. These non-heterocystous filamentous diazotrophs employ a potentially unique strategy of near-concurrent nitrogen fixation and oxygenic photosynthesis, potentially burdening Trichodesmium with a particularly high iron requirement due to the iron-binding proteins involved in these processes. Iron availability may therefore have a significant influence on the biogeography of Trichodesmium. Previous investigations of molecular responses to iron stress in this keystone marine microbe have largely been targeted. Here a holistic approach was taken using a label-free quantitative proteomics technique (MSE) to reveal a sophisticated multi-faceted proteomic response of Trichodesmium erythraeum IMS101 to iron stress. Increased abundances of proteins known to be involved in acclimation to iron stress and proteins known or predicted to be involved in iron uptake were observed, alongside decreases in the abundances of iron-binding proteins involved in photosynthesis and nitrogen fixation. Preferential loss of proteins with a high iron content contributed to overall reductions of 55–60% in estimated proteomic iron requirements. Changes in the abundances of iron-binding proteins also suggested the potential importance of alternate photosynthetic pathways as Trichodesmium reallocates the limiting resource under iron stress. Trichodesmium therefore displays a significant and integrated proteomic response to iron availability that likely contributes to the ecological success of this species in the ocean. PMID:26562022

  9. Iron

    MedlinePlus

    ... cereals and breads. White beans, lentils, spinach, kidney beans, and peas. Nuts and some dried fruits, such as raisins. Iron in food comes in two forms: heme iron and nonheme iron. Nonheme iron is found in plant foods and iron-fortified food products. Meat, seafood, ...

  10. 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 ...

  11. Integrated strategies needed to prevent iron deficiency and to promote early child development.

    PubMed

    Black, Maureen M

    2012-06-01

    Iron deficiency (ID) and iron deficiency anemia (IDA) are global public health problems that differentially impact pregnant women and infants in low and middle income countries. IDA during the first 1000 days of life (prenatally through 24 months) has been associated with long term deficits in children's socio-emotional, motor, cognitive, and physiological functioning. Mechanisms linking iron deficiency to children's development may include alterations to dopamine metabolism, myelination, and hippocampal structure and function, as well as maternal depression and unresponsive caregiving, potentially associated with maternal ID. Iron supplementation trials have had mixed success in promoting children's development. Evidence suggests that the most effective interventions to prevent iron deficiency and to promote early child development begin early in life and integrate strategies to ensure adequate iron and nutritional status, along with strategies to promote responsive mother-child interactions and early learning opportunities.

  12. Integrated Chemical Systems: The Simultaneous Formation of Hybrid Nanocomposites of Iron Oxide and Organo Silsesquioxanes

    SciTech Connect

    Zhao, L; Clapsaddle, B; Jr., J S; Schaefer, D; Shea, K

    2004-10-15

    A sol-gel approach for the synthesis of hybrid nanocomposites of iron oxide and bridged polysilsesquioxanes has been established. The procedures allow for the simultaneous formation of iron oxide and polysilsesquioxane networks in monolithic xerogels and aerogels. These hybrid nanocomposites are synthesized from FeCl{sub 3} {center_dot} 6H{sub 2}O and functionalized silsesquioxane monomers in a one-pot reaction using epoxides as a gelation agent. The porosity and microstructure of the materials has been determined by nitrogen porosimetry, electron microscopy and ultra small angle X-ray scattering (USAXS). The hybrid nanocomposites exhibit a uniform dispersion of both components with no evidence for phase separation at length scales > 5 nm. At this limit of resolution it is not possible to distinguish between two independent interpenetrating networks integrated at molecular length scales or a random copolymer or mixtures of both.

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

    NASA Astrophysics Data System (ADS)

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

    2006-02-01

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

  14. Involvement of Iron-Containing Proteins in Genome Integrity in Arabidopsis Thaliana.

    PubMed

    Zhang, Caiguo

    2015-01-01

    The Arabidopsis genome encodes numerous iron-containing proteins such as iron-sulfur (Fe-S) cluster proteins and hemoproteins. These proteins generally utilize iron as a cofactor, and they perform critical roles in photosynthesis, genome stability, electron transfer, and oxidation-reduction reactions. Plants have evolved sophisticated mechanisms to maintain iron homeostasis for the assembly of functional iron-containing proteins, thereby ensuring genome stability, cell development, and plant growth. Over the past few years, our understanding of iron-containing proteins and their functions involved in genome stability has expanded enormously. In this review, I provide the current perspectives on iron homeostasis in Arabidopsis, followed by a summary of iron-containing protein functions involved in genome stability maintenance and a discussion of their possible molecular mechanisms. PMID:27330736

  15. Involvement of Iron-Containing Proteins in Genome Integrity in Arabidopsis Thaliana

    PubMed Central

    Zhang, Caiguo

    2015-01-01

    The Arabidopsis genome encodes numerous iron-containing proteins such as iron-sulfur (Fe-S) cluster proteins and hemoproteins. These proteins generally utilize iron as a cofactor, and they perform critical roles in photosynthesis, genome stability, electron transfer, and oxidation-reduction reactions. Plants have evolved sophisticated mechanisms to maintain iron homeostasis for the assembly of functional iron-containing proteins, thereby ensuring genome stability, cell development, and plant growth. Over the past few years, our understanding of iron-containing proteins and their functions involved in genome stability has expanded enormously. In this review, I provide the current perspectives on iron homeostasis in Arabidopsis, followed by a summary of iron-containing protein functions involved in genome stability maintenance and a discussion of their possible molecular mechanisms. PMID:27330736

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

    PubMed

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

    2014-11-01

    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.

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

    PubMed

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

    2013-12-01

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

  18. Integration of magneto-optical active bismuth iron garnet on nongarnet substrates

    NASA Astrophysics Data System (ADS)

    Körner, Timo; Heinrich, Andreas; Weckerle, Martin; Roocks, Patrick; Stritzker, Bernd

    2008-04-01

    For optical communication, high quality magneto-optical active iron garnet films such as Y3Fe5O12 are important ceramic systems with extensive applications, e.g., as optical isolators [H. Dötsch et al., J. Opt. Soc. Am. B 22, 240 (2005)], optical modulators, etc. Thereby, garnets stand out due to their high Faraday rotation and low optical losses in the near infrared. Currently, it is desirable to integrate such macroscopic optical components on a single chip (Si, SiO2, etc.) to build up optical circuits as in the case of microelectronics (integrated optics) or the use for magneto-optical imaging. Up to now, Bi3Fe5O12 shows the highest Faraday rotation over 20°/μm. Unfortunately, Bi3Fe5O12 forms in a nonthermodynamical way. Thus, it can only be grown on garnet substrates which prevent it from direct deposition on substrates such as Si or SiO2. In our present work, we studied the integration of Bi3Fe5O12 on different SiO2 substrates using the pulsed laser deposition method. Therefore, we deposited an Y3Fe5O12 buffer first which was optimized in a postannealing step above 900°C in order to form a polycrystalline garnet phase, which is needed for further Bi3Fe5O12 growth. We measured the Faraday rotation of the double layered films and intensely studied them with x-ray diffraction, Rutherford backscattering spectroscopy, environmental scanning electron microscopy, and high-resolution transmission electron microscopy. The attained Faraday rotation can be compared with epitaxial Bi3Fe5O12 films grown on Gd3Ga5O12 substrates or even overcome them due to interference effects in the double layer. So they are highly attractive for magneto-optical imaging. For the determination of the film thicknesses which is usually done by Rutherford backscattering or profilometry, we used another approach. We measured the transmission spectra of the stack which we also derived from a theoretical model that uses a transfer matrix formalism. The thickness of the multilayer can be

  19. Iron-depletion promotes mitophagy to maintain mitochondrial integrity in pathogenic yeast Candida glabrata

    PubMed Central

    Nagi, Minoru; Tanabe, Koichi; Nakayama, Hironobu; Ueno, Keigo; Yamagoe, Satoshi; Umeyama, Takashi; Ohno, Hideaki; Miyazaki, Yoshitsugu

    2016-01-01

    ABSTRACT Candida glabrata, a haploid budding yeast, is the cause of severe systemic infections in immune-compromised hosts. The amount of free iron supplied to C. glabrata cells during systemic infections is severely limited by iron-chelating proteins such as transferrin. Thus, the iron-deficiency response in C. glabrata cells is thought to play important roles in their survival inside the host's body. In this study, we found that mitophagy was induced under iron-depleted conditions, and that the disruption of a gene homologous to ATG32, which is responsible for mitophagy in Saccharomyces cerevisiae, blocked mitophagy in C. glabrata. The mitophagic activity in C. glabrata cells was not detected on short-period exposure to nitrogen-starved conditions, which is a mitophagy-inducing condition used in S. cerevisiae. The mitophagy-deficient atg32Δ mutant of C. glabrata also exhibited decreased longevity under iron-deficient conditions. The mitochondrial membrane potential in Cgatg32Δ cells was significantly lower than that in wild-type cells under iron-depleted conditions. In a mouse model of disseminated infection, the Cgatg32Δ strain resulted in significantly decreased kidney and spleen fungal burdens compared with the wild-type strain. These results indicate that mitophagy in C. glabrata occurs in an iron-poor host tissue environment, and it may contribute to the longevity of cells, mitochondrial quality control, and pathogenesis. PMID:27347716

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

    NASA Astrophysics Data System (ADS)

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-01

    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.

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

    SciTech Connect

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-17

    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.

  2. Curie temperature, exchange integrals, and magneto-optical properties in off-stoichiometric bismuth iron garnet epitaxial films

    NASA Astrophysics Data System (ADS)

    Vertruyen, B.; Cloots, R.; Abell, J. S.; Jackson, T. J.; da Silva, R. C.; Popova, E.; Keller, N.

    2008-09-01

    We have studied the influence of the stoichiometry on the structural, magnetic, and magneto-optical properties of bismuth iron garnet (Bi3Fe5O12) thin films grown by pulsed laser deposition. Films with different stoichiometries have been obtained by varying the Bi/Fe ratio of the target and the oxygen pressure during deposition. Stoichiometry variations influence the Curie temperature TC by tuning the (Fe)-O-[Fe] geometry: TC increases when the lattice parameter decreases, contrary to what happens in the case of stoichiometric rare-earth iron garnets. The thermal variation of the magnetization, the Faraday rotation, and the Faraday ellipticity have been analyzed in the frame of the Néel two-sublattice magnetization model giving energies of -48K (4.1 meV), -29K (2.5 meV), and 84 K (7.3 meV) for the three magnetic exchange integrals jaa , jdd , and jad , respectively. Magneto-optical spectroscopy linked to compositional analysis by Rutherford backscattering spectroscopy shows that Bi and/or Fe deficiencies also affect the spectral variation (between 1.77 and 3.1 eV). Our results suggest that bismuth deficiency has an effect on the magneto-optical response of the tetrahedral Fe sublattice, whereas small iron deficiencies affect predominantly the magneto-optical response of the octahedral sublattice.

  3. 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...

  4. 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...

  5. Colour and toxic characteristics of metakaolinite-hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    NASA Astrophysics Data System (ADS)

    Sadasivam, Sivachidambaram; Thomas, Hywel Rhys

    2016-07-01

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    Laser exposures are performed on lithium iron phosphate battery electrodes at with process parameters based on those leading to the smallest heat affected zone for low power laser exposure at . 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.

  7. Integration of Genome-Scale Metabolic Nodels of Iron-Reducing Bacteria With Subsurface Flow and Geochemical Reactive Transport Models

    NASA Astrophysics Data System (ADS)

    Scheibe, T. D.; Mahadevan, R.; Fang, Y.; Garg, S.; Long, P. E.; Lovley, D. M.

    2008-12-01

    Several field and laboratory experiments have demonstrated that the growth and activity of iron-reducing bacteria can be stimulated in many subsurface environments by amendment of groundwater with a soluble electron donor. Under strong iron-reducing conditions, these organisms mediate reactions that can impact a wide range of subsurface contaminants including chlorinated hydrocarbons, metals, and radionuclides. Therefore there is strong interest in in-situ bioremediation as a potential technology for cleanup of contaminated aquifers. To evaluate and design bioremediation systems, as well as to evaluate the viability of monitored natural attenuation as an alternative, quantitative models of biogeochemically reactive transport are needed. To date, most such models represent microbial activity in terms of kinetic rate (e.g., Monod- type) formulations. Such models do not account for fundamental changes in microbial functionality (such as utilization of alternative respiratory pathways) that occur as the result of spatial and temporal variations in the geochemical environment experienced by microorganisms. Constraint-based genome-scale in silico models of microbial metabolism present an alternative to simplified rate formulations that provide flexibility to account for changes in microbial function in response to local geochemical conditions. We have developed and applied a methodology for coupling a constraint-based in silico model of Geobacter sulfurreducens with a conventional model of groundwater flow, transport, and geochemical reaction. Two uses of the in silico model are tested: 1) incorporation of modified microbial growth yield coefficients based on the in silico model, and 2) variation of reaction rates in a reactive transport model based on in silico modeling of a range of local geochemical conditions. Preliminary results from this integrated model will be presented.

  8. Iron Test

    MedlinePlus

    ... detect and help diagnose iron deficiency or iron overload. In people with anemia , these tests can help ... also be ordered when iron deficiency or iron overload is suspected. Early iron deficiency often goes unnoticed. ...

  9. Characterization of polycyclic aromatic hydrocarbons in fugitive PM10 emissions from an integrated iron and steel plant.

    PubMed

    Khaparde, V V; Bhanarkar, A D; Majumdar, Deepanjan; Rao, C V Chalapati

    2016-08-15

    Fugitive emissions of PM10 (particles <10μm in diameter) and associated polycyclic aromatic hydrocarbons (PAHs) were monitored in the vicinity of coking unit, sintering unit, blast furnace and steel manufacturing unit in an integrated iron and steel plant situated in India. Concentrations of PM10, PM10-bound total PAHs, benzo (a) pyrene, carcinogenic PAHs and combustion PAHs were found to be highest around the sintering unit. Concentrations of 3-ring and 4-ring PAHs were recorded to be highest in the coking unit whereas 5-and 6-ring PAHs were found to be highest in other units. The following indicatory PAHs were identified: indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, benzo (k) fluoranthene in blast furnace unit; indeno (1,2,3-cd) pyrene, dibenzo (a,h) anthracene, chrysene in sintering unit; Anthracene, fluoranthene, chrysene in coking unit and acenaphthene, fluoranthene, fluorene in steel making unit. Total-BaP-TEQ (Total BaP toxic equivalent quotient) and BaP-MEQ (Total BaP mutagenic equivalent quotient) concentration levels ranged from 2.4 to 231.7ng/m(3) and 1.9 to 175.8ng/m(3), respectively. BaP and DbA (dibenzo (a,h) anthracene) contribution to total-BaP-TEQ was found to be the highest. PMID:27099996

  10. New evidence on iron, copper accumulation and zinc depletion and its correlation with DNA integrity in aging human brain regions

    PubMed Central

    Vasudevaraju, P.; Bharathi; T, Jyothsna; Shamasundar, N. M.; Subba Rao, K.; Balaraj, B. M.; KSJ, Rao; T.S, Sathyanarayana Rao

    2010-01-01

    Deoxyribonucleic acid (DNA) conformation and stability play an important role in brain function. Earlier studies reported alterations in DNA integrity in the brain regions of neurological disorders like Parkinson’s and Alzheimer’s diseases. However, there are only limited studies on DNA stability in an aging brain and the factors responsible for genomic instability are still not clear. In this study, we assess the levels of Copper (Cu), Iron (Fe) and Zinc (Zn) in three age groups (Group I: below 40 years), Group II: between 41-60 years) and Group III: above 61 years) in hippocampus and frontal cortex regions of normal brains. The number of samples in each group was eight. Genomic DNA was isolated and DNA integrity was studied by nick translation studies and presented as single and double strand breaks. The number of single strand breaks correspondingly increased with aging compared to double strand breaks. The strand breaks were more in frontal cortex compared to hippocampus. We observed that the levels of Cu and Fe are significantly elevated while Zn is significantly depleted as one progresses from Group I to Group III, indicating changes with aging in frontal cortex and hippocampus. But the elevation of metals was more in frontal cortical region compared to hippocampal region. There was a clear correlation between Cu and Fe levels versus strand breaks in aging brain regions. This indicates that genomic instability is progressive with aging and this will alter the gene expressions. To our knowledge, this is a new comprehensive database to date, looking at the levels of redox metals and corresponding strand breaks in DNA in two brain regions of the aging brain. The biological significance of these findings with relevance to mental health will be discussed. PMID:20838501

  11. Integrated analysis of the {open_quotes}sponge iron reactor and fuel cell system{close_quotes}

    SciTech Connect

    Lehrhofer, J.; Ghaemi, M.; Wernigg, H.

    1996-12-31

    The system Sponge Iron Reactor/Fuel Cell (SIR/FC) is investigated from the ecological and technical aspects and also the pre-conversion energy chain as a part of the natural gas fuel cycle is analyzed. What are the decisive characteristics of a sponge iron reactor or the basic process cycle sponge iron/hydrogen/iron oxide? This process cycle offers a simple possibility to store the energy of synthesis gases in the form of sponge iron and at the same time to reform and condition these synthesis gases. As {open_quote}product{close_quote} of this energy storage one receives pure hydrogen which is intended for the running of fuel cells.

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

    PubMed

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

    1993-12-01

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

  13. Iron-Air Rechargeable Battery

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    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.

  14. Iron Uptake via DMT1 Integrates Cell Cycle with JAK-STAT3 Signaling to Promote Colorectal Tumorigenesis.

    PubMed

    Xue, Xiang; Ramakrishnan, Sadeesh K; Weisz, Kevin; Triner, Daniel; Xie, Liwei; Attili, Durga; Pant, Asha; Győrffy, Balázs; Zhan, Mingkun; Carter-Su, Christin; Hardiman, Karin M; Wang, Thomas D; Dame, Michael K; Varani, James; Brenner, Dean; Fearon, Eric R; Shah, Yatrik M

    2016-09-13

    Dietary iron intake and systemic iron balance are implicated in colorectal cancer (CRC) development, but the means by which iron contributes to CRC are unclear. Gene expression and functional studies demonstrated that the cellular iron importer, divalent metal transporter 1 (DMT1), is highly expressed in CRC through hypoxia-inducible factor 2α-dependent transcription. Colon-specific Dmt1 disruption resulted in a tumor-selective inhibitory effect of proliferation in mouse colon tumor models. Proteomic and genomic analyses identified an iron-regulated signaling axis mediated by cyclin-dependent kinase 1 (CDK1), JAK1, and STAT3 in CRC progression. A pharmacological inhibitor of DMT1 antagonized the ability of iron to promote tumor growth in a CRC mouse model and a patient-derived CRC enteroid orthotopic model. Our studies implicate a growth-promoting signaling network instigated by elevated intracellular iron levels in tumorigenesis, offering molecular insights into how a key dietary component may contribute to CRC.

  15. Iron Chelation

    MedlinePlus

    ... iron overload and need treatment. What is iron overload? Iron chelation therapy is used when you have ... may want to perform: How quickly does iron overload happen? This is different for each person. It ...

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

    SciTech Connect

    A.A. Akberdin; A.S. Kim

    2008-08-15

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

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

    PubMed

    Goto, Taichi; Onbaşlı, Mehmet C; Ross, C A

    2012-12-17

    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.

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

    SciTech Connect

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

    2013-05-07

    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.

  19. Iron biofortification of wheat grains through integrated use of organic and chemical fertilizers in pH affected calcareous soil.

    PubMed

    Ramzani, Pia Muhammad Adnan; Khalid, Muhammad; Naveed, Muhammad; Ahmad, Rashid; Shahid, Muhammad

    2016-07-01

    Incidence of iron (Fe) deficiency in human populations is an emerging global challenge. This study was conducted to evaluate the potential of iron sulphate combined with biochar and poultry manure for Fe biofortification of wheat grains in pH affected calcareous soil. In first two incubation studies, rates of sulfur (S) and Fe combined with various organic amendments for lowering pH and Fe availability in calcareous soil were optimized. In pot experiment, best rate of Fe along with biochar (BC) and poultry manure (PM) was evaluated for Fe biofortification of wheat in normal and S treated low pH calcareous soil. Fe applied with BC provided fair increase in root-shoot biomass and photosynthesis up to 79, 53 and 67%, respectively in S treated low pH soil than control. Grain Fe and ferritin concentration was increased up to 1.4 and 1.2 fold, respectively while phytate and polyphenol was decreased 35 and 44%, respectively than control in treatment where Fe was applied with BC and S. In conclusion, combined use of Fe and BC could be an effective approach to improve growth and grain Fe biofortification of wheat in pH affected calcareous soil. PMID:27179316

  20. Iron biofortification of wheat grains through integrated use of organic and chemical fertilizers in pH affected calcareous soil.

    PubMed

    Ramzani, Pia Muhammad Adnan; Khalid, Muhammad; Naveed, Muhammad; Ahmad, Rashid; Shahid, Muhammad

    2016-07-01

    Incidence of iron (Fe) deficiency in human populations is an emerging global challenge. This study was conducted to evaluate the potential of iron sulphate combined with biochar and poultry manure for Fe biofortification of wheat grains in pH affected calcareous soil. In first two incubation studies, rates of sulfur (S) and Fe combined with various organic amendments for lowering pH and Fe availability in calcareous soil were optimized. In pot experiment, best rate of Fe along with biochar (BC) and poultry manure (PM) was evaluated for Fe biofortification of wheat in normal and S treated low pH calcareous soil. Fe applied with BC provided fair increase in root-shoot biomass and photosynthesis up to 79, 53 and 67%, respectively in S treated low pH soil than control. Grain Fe and ferritin concentration was increased up to 1.4 and 1.2 fold, respectively while phytate and polyphenol was decreased 35 and 44%, respectively than control in treatment where Fe was applied with BC and S. In conclusion, combined use of Fe and BC could be an effective approach to improve growth and grain Fe biofortification of wheat in pH affected calcareous soil.

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

    PubMed Central

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

    2011-01-01

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

  2. Fully quantum mechanical calculation of the diffusivity of hydrogen in iron using the tight-binding approximation and path integral theory

    NASA Astrophysics Data System (ADS)

    Katzarov, Ivaylo H.; Pashov, Dimitar L.; Paxton, Anthony T.

    2013-08-01

    We present calculations of free energy barriers and diffusivities as functions of temperature for the diffusion of hydrogen in α-Fe. This is a fully quantum mechanical approach since the total energy landscape is computed using a self-consistent, transferable tight binding model for interstitial impurities in magnetic iron. Also the hydrogen nucleus is treated quantum mechanically and we compare here two approaches in the literature both based in the Feynman path integral formulation of statistical mechanics. We find that the quantum transition state theory which admits greater freedom for the proton to explore phase space gives result in better agreement with experiment than the alternative which is based on fixed centroid calculations of the free energy barrier. This will have an impact on future modeling and the simulation of hydrogen trapping and diffusion.

  3. Iron deficiency.

    PubMed

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world.

  4. Atmospheric iron deposition: global distribution, variability, and human perturbations.

    PubMed

    Mahowald, Natalie M; Engelstaedter, Sebastian; Luo, Chao; Sealy, Andrea; Artaxo, Paulo; Benitez-Nelson, Claudia; Bonnet, Sophie; Chen, Ying; Chuang, Patrick Y; Cohen, David D; Dulac, Francois; Herut, Barak; Johansen, Anne M; Kubilay, Nilgun; Losno, Remi; Maenhaut, Willy; Paytan, Adina; Prospero, Joseph M; Shank, Lindsey M; Siefert, Ronald L

    2009-01-01

    Atmospheric inputs of iron to the open ocean are hypothesized to modulate ocean biogeochemistry. This review presents an integration of available observations of atmospheric iron and iron deposition, and also covers bioavailable iron distributions. Methods for estimating temporal variability in ocean deposition over the recent past are reviewed. Desert dust iron is estimated to represent 95% of the global atmospheric iron cycle, and combustion sources of iron are responsible for the remaining 5%. Humans may be significantly perturbing desert dust (up to 50%). The sources of bioavailable iron are less well understood than those of iron, partly because we do not know what speciation of the iron is bioavailable. Bioavailable iron can derive from atmospheric processing of relatively insoluble desert dust iron or from direct emissions of soluble iron from combustion sources. These results imply that humans could be substantially impacting iron and bioavailable iron deposition to ocean regions, but there are large uncertainties in our understanding.

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

    SciTech Connect

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

    2010-09-30

    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

  6. Iron Meteorite

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A meteorite composed mainly of nickel-iron, with traces of other metals; also referred to simply as an iron, and formerly known as a siderite. Irons account for over 6% of all known meteorite specimens. They are the easiest type to identify, being heavy, magnetic and rust-colored; their metallic sheen tarnishes quickly on the Earth's surface, but otherwise irons show better resistance to weatheri...

  7. The fractionation and geochemical characteristics of rare earth elements measured in ambient size-resolved PM in an integrated iron and steelmaking industry zone.

    PubMed

    Dai, Qili; Li, Liwei; Yang, Jiamei; Liu, Baoshuang; Bi, Xiaohui; Wu, Jianhui; Zhang, YuFen; Yao, Lin; Feng, Yinchang

    2016-09-01

    Improved understanding of the fractionation and geochemical characteristic of rare earth elements (REEs) from steel plant emissions is important due to the unclear atmospheric signature of these elements and their adverse impact on human health and the environment. In this study, ambient particulate matter of different sizes was collected from one site in an integrated iron and steelmaking industrial zone (HG) and one urban background site with no direct industrial emissions (ZWY) during a 1-year sampling campaign in China. The total concentrations of REEs for TSP, PM10, and PM2.5 were 27.248, 14.989, 3.542 ng/m(3) in HG and 6.326, 5.274, 1.731 ng/m(3), respectively, in ZWY, which revealed the local influence of the steelmaking activities to the air quality. With respect to ZWY, the REEs in HG site are obviously fractionated in the coarser fraction, and LREEs account for more than 80 % of the total REE burden in all of the samples. Additionally, the REEs in HG and ZWY show a homogeneous trend with successively increased LREE/HREE ratios from the coarse particles to the fine particles. In our samples, La, Ce, Nd, and Sm are the most enriched rare earth elements, especially in the HG site. Moreover, ternary diagrams of LaCeSm indicate that the REEs in HG are potentially contributed by steelworks, carrier vehicles, coal combustion, and road dust re-suspension.

  8. Integrating classical and molecular approaches to evaluate the impact of nanosized zero-valent iron (nZVI) on soil organisms.

    PubMed

    Saccà, Maria Ludovica; Fajardo, Carmen; Costa, Gonzalo; Lobo, Carmen; Nande, Mar; Martin, Margarita

    2014-06-01

    Nanosized zero-valent iron (nZVI) is a new option for the remediation of contaminated soil and groundwater, but the effect of nZVI on soil biota is mostly unknown. In this work, nanotoxicological studies were performed in vitro and in two different standard soils to assess the effect of nZVI on autochthonous soil organisms by integrating classical and molecular analysis. Standardised ecotoxicity testing methods using Caenorhabditis elegans were applied in vitro and in soil experiments and changes in microbial biodiversity and biomarker gene expression were used to assess the responses of the microbial community to nZVI. The classical tests conducted in soil ruled out a toxic impact of nZVI on the soil nematode C. elegans in the test soils. The molecular analysis applied to soil microorganisms, however, revealed significant changes in the expression of the proposed biomarkers of exposure. These changes were related not only to the nZVI treatment but also to the soil characteristics, highlighting the importance of considering the soil matrix on a case by case basis. Furthermore, due to the temporal shift between transcriptional responses and the development of the corresponding phenotype, the molecular approach could anticipate adverse effects on environmental biota.

  9. Revealing the broad iron Kα line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

    NASA Astrophysics Data System (ADS)

    Duro, Refiz; Dauser, Thomas; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A.; Kreykenbohm, Sonja; Cadolle Bel, Marion; Bodaghee, Arash; Lohfink, Anne; Reynolds, Christopher S.; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Staubert, Rüdiger; Wilms, Jörn

    2016-05-01

    We report on the analysis of the broad Fe Kα line feature of Cyg X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kα reflection line at 6.4 keV with a very high signal to noise ratio. The 4-500 keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole parameters with a spin of a ~ 0.9, in agreement with recent measurements from reflection and disk continuum fitting. The inclination is found to be i ~ 30°, consistent with the orbital inclination and different from inclination measurements made during the soft state, which show a higher inclination. We speculate that the difference between the inclination measurements is due to changes in the inner region of the accretion disk.

  10. 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

    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

    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

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

    PubMed

    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

    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.

  12. Iron refractory iron deficiency anemia

    PubMed Central

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

    2013-01-01

    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

  13. The Involvement of OsPHO1;1 in the Regulation of Iron Transport Through Integration of Phosphate and Zinc Deficiency Signaling

    PubMed Central

    Saenchai, Chorpet; Bouain, Nadia; Kisko, Mushtak; Prom-u-thai, Chanakan; Doumas, Patrick; Rouached, Hatem

    2016-01-01

    Plants survival depends on their ability to cope with multiple nutrient stresses that often occur simultaneously, such as the limited availability of essential elements inorganic phosphate (Pi), zinc (Zn), and iron (Fe). Previous research has provided information on the genes involved in efforts by plants to maintain homeostasis when a single nutrient (Pi, Zn, or Fe) is depleted. Recent findings on nutritional stress suggest that plant growth capacity is influenced by a complex tripartite interaction between Pi, Zn, and Fe homeostasis. However, despite its importance, how plants integrate multiple nutritional stimuli into complex developmental programs, and which genes are involved in this tripartite (Pi ZnFe) interaction is still not clear. The aim of this study was to examine the physiological and molecular responses of rice (Oriza sativa L.) to a combination of Pi, Zn, and/or Fe deficiency stress conditions. Results showed that Fe deficiency had the most drastic single-nutrient effect on biomass, while the Zn deficiency-effect depended on the presence of Pi in the medium. Interestingly, the observed negative effect of Fe starvation was alleviated by concomitant Pi or PiZn depletion. Members of the OsPHO1 family showed a differential transcriptional regulation in response PiZnFe combinatory stress conditions. Particularly, the transcripts of the OsPHO1;1 sense and its natural antisense cis-NatPHO1;1 showed the highest accumulation under PiZn deficiency. In this condition, the Ospho1;1 mutants showed over-accumulation of Fe in roots compared to wild type plants. These data reveal coordination between pathways involved in Fe transport and PiZn signaling in rice which involves the OsPHO1; 1, and support the hypothesis of a genetic basis for Pi, Zn, and Fe signaling interactions in plants. PMID:27092147

  14. METABOLISM OF IRON STORES

    PubMed Central

    SAITO, HIROSHI

    2014-01-01

    ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since the pioneering research by Shoden in 1953. However, we recently developed a new method for determining ferritin iron and hemosiderin iron by computer-assisted serum ferritin kinetics. Serum ferritin increase or decrease curves were measured in patients with normal storage iron levels (chronic hepatitis C and iron deficiency anemia treated by intravenous iron injection), and iron overload (hereditary hemochromatosis and transfusion dependent anemia). We thereby confirmed the existence of two iron pathways where iron flows followed the numbered order (1) labile iron, (2) ferritin and (3) hemosiderin in iron deposition and mobilization among many previously proposed but mostly unproven routes. We also demonstrated the increasing and decreasing phases of ferritin iron and hemosiderin iron in iron deposition and mobilization. The author first demonstrated here the change in proportion between pre-existing ferritin iron and new ferritin iron synthesized by removing iron from hemosiderin in the course of iron removal. In addition, the author disclosed the cause of underestimation of storage iron turnover rate which had been reported by previous investigators in estimating storage iron turnover rate of normal subjects. PMID:25741033

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

    PubMed

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

    2014-10-01

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

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

    PubMed

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

    2014-10-20

    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.

  17. Integrating Mobile Phones into Science Teaching to Help Students Develop a Procedure to Evaluate the Corrosion Rate of Iron in Simulated Seawater

    ERIC Educational Resources Information Center

    Moraes, Edgar P.; Confessor, Mario R.; Gasparotto, Luiz H. S.

    2015-01-01

    This article proposes an indirect method to evaluate the corrosion rate of iron nail in simulated seawater. The official procedure is based on the direct measurement of the specimen's weight loss over time; however, a highly precise scale is required and such equipment may not be easily available. On the other hand, mobile phones equipped with…

  18. Ferric iron reduction and iron assimilation in Saccharomyces cerevisiae.

    PubMed

    Anderson, G J; Lesuisse, E; Dancis, A; Roman, D G; Labbe, P; Klausner, R D

    We have used the yeast Saccharomyces cerevisiae as a model organism to study the role of ferric iron reduction in eucaryotic iron uptake. S. cerevisiae is able to utilize ferric chelates as an iron source by reducing the ferric iron to the ferrous form, which is subsequently internalized by the cells. A gene (FRE1) was identified which encodes a protein required for both ferric iron reduction and efficient ferric iron assimilation, thus linking these two activities. The predicted FRE1 protein appears to be a membrane protein and shows homology to the beta-subunit of the human respiratory burst oxidase. These data suggest that FRE1 is a structural component of the ferric reductase. Subcellular fractionation studies showed that the ferric reductase activity of isolated plasma membranes did not reflect the activity of the intact cells, implying that cellular integrity was necessary for function of the major S. cerevisiae ferric reductase. An NADPH-dependent plasma membrane ferric reductase was partially purified from plasma membranes. Preliminary evidence suggests that the cell surface ferric reductase may, in addition to mediating cellular iron uptake, help modulate the intracellular redox potential of the yeast cell.

  19. Iron and alloys of iron. [lunar resources

    NASA Technical Reports Server (NTRS)

    Sastri, Sankar

    1992-01-01

    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.

  20. Iron and iron derived radicals

    SciTech Connect

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

    1987-04-01

    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.

  1. A novel integration system of magnetically immobilized cells and a pair of graphite plate-stainless iron mesh electrodes for the bioremediation of coking wastewater.

    PubMed

    Jiang, Bei; Tan, Liang; Ning, Shuxiang; Shi, Shengnan

    2016-09-01

    Magnetically immobilized cells of Comamonas sp. JB coupling with electrode reaction was developed to enhance the treatment efficiency of coking wastewater containing phenol, carbazole (CA), dibenzofuran (DBF), and dibenzothiophene (DBT). The pair of graphite plate-stainless iron mesh electrodes was chosen as the most suitable electrodes. Magnetically immobilized cells coupling with graphite plate-stainless iron mesh electrodes (coupling system) exhibited high degradation activity for all the compounds, which were significantly higher than the sum by single magnetically immobilized cells and electrode reaction at the optimal voltage. Recycling experiments demonstrated that the degradation activity of coupling system increased gradually during eight recycles, indicating that there was a coupling effect between the biodegradation and electrode reaction. Phenol hydroxylase and qPCR assays confirmed that appropriate electrical stimulation could improve phenol hydroxylase activity and promote cells growth. Toxicity assessment suggested the treatment of the coking wastewater by coupling system led to less toxicity than untreated wastewater. PMID:27289060

  2. Alternative control techniques document: PM-10 emissions from selected processes at coke ovens and integrated iron and steel mills. Final report

    SciTech Connect

    Marsosudiro, P.J.; Snow, W.S.

    1994-02-01

    The purpose of the document is to provide guidance to state and local air quality management agencies for determining reasonably available control technologies (RACT) and best available control technologies (BACT) that apply to PM-10 sources in the iron and steel industry. Emission sources addressed are coke pushing, coke quenching, coke sizing and screening, casthouse operations, hot metal transfer, and desulfurization. These sources were selected for analysis because they are not presently regulated under New Source Performance Standards (NSPS). Emission control system descriptions, environmental and energy impact assessments, and control cost analyses are presented. The principal emission collection devices used are the fabric filter and wet venturi scrubber.

  3. Pharmacology of Iron Transport

    PubMed Central

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

    2013-01-01

    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

  4. 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

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

    1997-11-01

    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.

  5. Genetics Home Reference: iron-refractory iron deficiency anemia

    MedlinePlus

    ... refractory iron deficiency anemia iron-refractory iron deficiency anemia Enable Javascript to view the expand/collapse boxes. ... All Close All Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

  6. The liver: conductor of systemic iron balance

    PubMed Central

    Meynard, Delphine; Babitt, Jodie L.

    2014-01-01

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

  7. HEPCIDIN AND IRON HOMEOSTASIS

    PubMed Central

    Ganz, Tomas; Nemeth, Elizabeta

    2014-01-01

    Despite fluctuations in dietary iron intake and intermittent losses through bleeding, the plasma iron concentrations in humans remain stable at 10–30 μM. While most of the iron entering blood plasma comes from recycling, appropriate amount of iron is absorbed from the diet to compensate for losses and maintain nontoxic amounts in stores. Plasma iron concentration and iron distribution are similarly regulated in laboratory rodents. The hepatic peptide hepcidin was identified as the systemic iron-regulatory hormone. In the efferent arc, hepcidin regulates intestinal iron absorption, plasma iron concentrations, and tissue iron distribution by inducing degradation of its receptor, the cellular iron exporter ferroportin. Ferroportin exports iron into plasma from absorptive enterocytes, from macrophages that recycle the iron of senescent erythrocytes, and from hepatocytes that store iron. In the more complex and less well understood afferent arc, hepatic hepcidin synthesis is transcriptionally regulated by extracellular and intracellular iron concentrations through a molecular complex of bone morphogenetic protein receptors and their iron-specific ligands, modulators and iron sensors. Through as yet undefined pathways, hepcidin is also homeostatically regulated by the iron requirements of erythroid precursors for hemoglobin synthesis. In accordance with the role of hepcidin-mediated iron redistribution in host defense, hepcidin production is regulated by inflammation as well. Increased hepcidin concentrations in plasma are pathogenic in iron-restrictive anemias including anemias associated with inflammation, chronic kidney disease and some cancers. Hepcidin deficiency causes iron overload in hereditary hemochromatosis and ineffective erythropoiesis. Hepcidin, ferroportin and their regulators represent potential targets for the diagnosis and treatment of iron disorders and anemias. PMID:22306005

  8. [Iron-refractory iron deficiency anemia].

    PubMed

    Kawabata, Hiroshi

    2016-02-01

    The major causes of iron deficiency anemia (IDA) include iron loss due to bleeding, increased iron requirements, and decreased iron absorption by the intestine. The most common cause of IDA in Japanese women is iron loss during menstruation. Autoimmune atrophic gastritis and Helicobacter pylori infection can also cause IDA by reducing intestinal iron absorption. In addition to these common etiologies, germline mutations of TMPRSS6 can cause iron-refractory IDA (IRIDA). TMPRSS6 encodes matriptase-2, a membrane-bound serine protease primarily expressed in the liver. Functional loss of matriptase-2 due to homozygous mutations results in an increase in the expression of hepcidin, which is the key regulator of systemic iron homeostasis. The serum hepcidin increase in turn leads to a decrease in iron supply from the intestine and macrophages to erythropoietic cells. IRIDA is microcytic and hypochromic, but decreased serum ferritin is not observed as in IDA. IRIDA is refractory to oral iron supplementation, but does respond to intravenous iron supplementation to some extent. Because genetic testing is required for the diagnoses of IRIDA, a considerable number of cases may go undiagnosed and may thus be overlooked.

  9. Iron deficiency anemia

    MedlinePlus

    Anemia - iron deficiency ... iron from old red blood cells. Iron deficiency anemia develops when your body's iron stores run low. ... You may have no symptoms if the anemia is mild. Most of the time, ... slowly. Symptoms may include: Feeling weak or tired more often ...

  10. Iron status of vegetarians.

    PubMed

    Craig, W J

    1994-05-01

    An appropriately planned well-balanced vegetarian diet is compatible with an adequate iron status. Although the iron stores of vegetarians may be reduced, the incidence of iron-deficiency anemia in vegetarians is not significantly different from that in omnivores. Restrictive vegetarian diets (eg, macrobiotic) are associated with more widespread iron-deficiency anemia. Western vegetarians who consume a variety of foods have a better iron status than do those in developing countries who consume a limited diet based on unleavened, unrefined cereals. Whereas phytates, polyphenolics, and other plant constituents found in vegetarian diets inhibit nonheme-iron absorption, vitamin C, citric acid, and other organic acids facilitate nonheme-iron absorption.

  11. Neonatal iron nutrition.

    PubMed

    Rao, R; Georgieff, M K

    2001-10-01

    Preterm infants are prone to iron deficiency. Their total body iron content at birth is low and gets further depleted by clinical practices such as uncompensated phlebotomy losses and exogenous erythropoietin administration during the neonatal period. Early iron deficiency appears to adversely affect cognitive development in human infants. To maintain iron sufficiency and meet the iron demands of catch-up postnatal growth, iron supplementation is prudent in preterm infants. A dose of 2-4 mg/kg/day is recommended for preterm infants who are fed exclusively human milk. A dose of 6 mg/kg/day or more is needed with the use of exogenous erythropoietin or to correct preexisting iron deficiency. However, due to the poor antioxidant capabilities of preterm infants and the potential role of iron in several oxidant-related perinatal disorders, indiscriminate iron supplementation should be avoided.

  12. Mitochondrial Iron-Sulfur Cluster Activity and Cytosolic Iron Regulate Iron Traffic in Saccharomyces cerevisiae.

    PubMed

    Wofford, Joshua D; Lindahl, Paul A

    2015-11-01

    An ordinary differential equation-based mathematical model was developed to describe trafficking and regulation of iron in growing fermenting budding yeast. Accordingly, environmental iron enters the cytosol and moves into mitochondria and vacuoles. Dilution caused by increasing cell volume is included. Four sites are regulated, including those in which iron is imported into the cytosol, mitochondria, and vacuoles, and the site at which vacuolar Fe(II) is oxidized to Fe(III). The objective of this study was to determine whether cytosolic iron (Fecyt) and/or a putative sulfur-based product of iron-sulfur cluster (ISC) activity was/were being sensed in regulation. The model assumes that the matrix of healthy mitochondria is anaerobic, and that in ISC mutants, O2 diffuses into the matrix where it reacts with nonheme high spin Fe(II) ions, oxidizing them to nanoparticles and generating reactive oxygen species. This reactivity causes a further decline in ISC/heme biosynthesis, which ultimately gives rise to the diseased state. The ordinary differential equations that define this model were numerically integrated, and concentrations of each component were plotted versus the concentration of iron in the growth medium and versus the rate of ISC/heme biosynthesis. Model parameters were optimized by fitting simulations to literature data. The model variant that assumed that both Fecyt and ISC biosynthesis activity were sensed in regulation mimicked observed behavior best. Such "dual sensing" probably arises in real cells because regulation involves assembly of an ISC on a cytosolic protein using Fecyt and a sulfur species generated in mitochondria during ISC biosynthesis and exported into the cytosol.

  13. Iron and copper release in drinking-water distribution systems.

    PubMed

    Shi, Baoyou; Taylor, James S

    2007-09-01

    A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature.

  14. Serum iron test

    MedlinePlus

    ... of iron homeostasis: iron deficiency and overload. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, ... EJ, Gardner LB. Anemia of chronic diseases. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, ...

  15. Total iron binding capacity

    MedlinePlus

    ... GM. Disorders of iron homeostasis: iron deficiency and overload. In: Hoffman R, Benz EJ Jr, Silberstein LE, ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

  16. Iron and Your Child

    MedlinePlus

    ... 24 months old. Serve iron-rich foods alongside foods containing vitamin C — such as tomatoes, broccoli, oranges, and strawberries — which improves the body's absorption of iron. Avoid serving coffee ...

  17. Ferrous Sulfate (Iron)

    MedlinePlus

    ... cells. It is used to treat or prevent iron-deficiency anemia, a condition that occurs when the body ... than prescribed by your doctor.Although symptoms of iron deficiency usually improve within a few days, you may ...

  18. Iron losses in sweat

    SciTech Connect

    Brune, M.; Magnusson, B.; Persson, H.; Hallberg, L.

    1986-03-01

    The losses of iron in whole body cell-free sweat were determined in eleven healthy men. A new experimental design was used with a very careful cleaning procedure of the skin and repeated consecutive sampling periods of sweat in a sauna. The purpose was to achieve a steady state of sweat iron losses with minimal influence from iron originating from desquamated cells and iron contaminating the skin. A steady state was reached in the third sauna period (second sweat sampling period). Iron loss was directly related to the volume of sweat lost and amounted to 22.5 micrograms iron/l sweat. The findings indicate that iron is a physiological constituent of sweat and derived not only from contamination. Present results imply that variations in the amount of sweat lost will have only a marginal effect on the variation in total body iron losses.

  19. 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.

  20. Treatment of mature landfill leachate by internal micro-electrolysis integrated with coagulation: a comparative study on a novel sequencing batch reactor based on zero valent iron.

    PubMed

    Ying, Diwen; Peng, Juan; Xu, Xinyan; Li, Kan; Wang, Yalin; Jia, Jinping

    2012-08-30

    A comparative study of treating mature landfill leachate with various treatment processes was conducted to investigate whether the method of combined processes of internal micro-electrolysis (IME) without aeration and IME with full aeration in one reactor was an efficient treatment for mature landfill leachate. A specifically designed novel sequencing batch internal micro-electrolysis reactor (SIME) with the latest automation technology was employed in the experiment. Experimental data showed that combined processes obtained a high COD removal efficiency of 73.7 ± 1.3%, which was 15.2% and 24.8% higher than that of the IME with and without aeration, respectively. The SIME reactor also exhibited a COD removal efficiency of 86.1 ± 3.8% to mature landfill leachate in the continuous operation, which is much higher (p<0.05) than that of conventional treatments of electrolysis (22.8-47.0%), coagulation-sedimentation (18.5-22.2%), and the Fenton process (19.9-40.2%), respectively. The innovative concept behind this excellent performance is a combination effect of reductive and oxidative processes of the IME, and the integration electro-coagulation. Optimal operating parameters, including the initial pH, Fe/C mass ratio, air flow rate, and addition of H(2)O(2), were optimized. All results show that the SIME reactor is a promising and efficient technology in treating mature landfill leachate. PMID:22771343

  1. Treatment of mature landfill leachate by internal micro-electrolysis integrated with coagulation: a comparative study on a novel sequencing batch reactor based on zero valent iron.

    PubMed

    Ying, Diwen; Peng, Juan; Xu, Xinyan; Li, Kan; Wang, Yalin; Jia, Jinping

    2012-08-30

    A comparative study of treating mature landfill leachate with various treatment processes was conducted to investigate whether the method of combined processes of internal micro-electrolysis (IME) without aeration and IME with full aeration in one reactor was an efficient treatment for mature landfill leachate. A specifically designed novel sequencing batch internal micro-electrolysis reactor (SIME) with the latest automation technology was employed in the experiment. Experimental data showed that combined processes obtained a high COD removal efficiency of 73.7 ± 1.3%, which was 15.2% and 24.8% higher than that of the IME with and without aeration, respectively. The SIME reactor also exhibited a COD removal efficiency of 86.1 ± 3.8% to mature landfill leachate in the continuous operation, which is much higher (p<0.05) than that of conventional treatments of electrolysis (22.8-47.0%), coagulation-sedimentation (18.5-22.2%), and the Fenton process (19.9-40.2%), respectively. The innovative concept behind this excellent performance is a combination effect of reductive and oxidative processes of the IME, and the integration electro-coagulation. Optimal operating parameters, including the initial pH, Fe/C mass ratio, air flow rate, and addition of H(2)O(2), were optimized. All results show that the SIME reactor is a promising and efficient technology in treating mature landfill leachate.

  2. Iron Dextran Injection

    MedlinePlus

    ... called iron replacement products. It works by replenishing iron stores so that the body can make more red blood cells. ... and order certain lab tests to check your body's response to iron dextran injection.Before having any laboratory test, tell ...

  3. Iron-Deficiency Anemia

    MedlinePlus

    ... the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, easily ... Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the ...

  4. Iron and the liver.

    PubMed

    Pietrangelo, Antonello

    2016-01-01

    Humans have evolved to retain iron in the body and are exposed to a high risk of iron overload and iron-related toxicity. Excess iron in the blood, in the absence of increased erythropoietic needs, can saturate the buffering capacity of serum transferrin and result in non-transferrin-bound highly reactive forms of iron that can cause damage, as well as promote fibrogenesis and carcinogenesis in the parenchymatous organs. A number of hereditary or acquired diseases are associated with systemic or local iron deposition or iron misdistribution in organs or cells. Two of these, the HFE- and non-HFE hemochromatosis syndromes represent the paradigms of genetic iron overload. They share common clinical features and the same pathogenic basis, in particular, a lack of synthesis or activity of hepcidin, the iron hormone. Before hepcidin was discovered, the liver was simply regarded as the main site of iron storage and, as such, the main target of iron toxicity. Now, as the main source of hepcidin, it appears that the loss of the hepcidin-producing liver mass or genetic and acquired factors that repress hepcidin synthesis in the liver may also lead to iron overload. Usually, there is low-grade excess iron which, through oxidative stress, is sufficient to worsen the course of the underlying liver disease or other chronic diseases that are apparently unrelated to iron, such as chronic metabolic and cardiovascular diseases. In the future, modulation of hepcidin synthesis and activity or hepcidin hormone-replacing strategies may become therapeutic options to cure iron-related disorders.

  5. Iron, radiation, and cancer.

    PubMed Central

    Stevens, R G; Kalkwarf, D R

    1990-01-01

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

  6. Vapor-Liquid Partitioning of Iron and Manganese in Hydrothermal Fluids: An Experimental Investigation with Application to the Integrated Study of Basalt-hosted Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Pester, N. J.; Seyfried, W. E.

    2010-12-01

    The chemistry of deep-sea hydrothermal vent fluids, expressed at the seafloor, reflects a complex history of physicochemical reactions. After three decades of field and experimental investigations, the processes of fluid-mineral equilibria that transform seawater into that of a typical “black smoker” are generally well described in the literature. Deep crustal fluids, when encountering a given heat source that ultimately drives hydrothermal circulation, routinely intersect the two-phase boundary. This process results in the nearly ubiquitous observations of variable salinity in vent fluids and is often a secondary driver of circulation via the evolution of a more buoyant (i.e. less saline) phase. Phase separation in chemically complex fluids results in the partitioning of dissolved species between the two evolved phases that deviates from simple charge balance calculations and these effects become more prominent with increasing temperature and/or decreasing pressure along the two-phase envelope. This process of partitioning has not been extensively studied and the interplay between the effects of phase separation and fluid-mineral equilibrium are not well understood. Most basalt-hosted hydrothermal systems appear to enter a steady state mode wherein fluids approach the heat source at depth and rise immediately once the two-phase boundary is met. Thus, venting fluids exhibit only modest deviations from seawater bulk salinity and the effects of partitioning are likely minor for all but the most volatile elements. Time series observations at integrated study sites, however, demonstrate dynamic changes in fluid chemistry following eruptions/magmatic events, including order of magnitude increases in gas concentrations and unexpectedly high Fe/Cl ratios. In this case, the time dependence of vapor-liquid partitioning relative to fluid-mineral equilibrium must be considered when attempting to interpret changes in subsurface reaction conditions. The two-phase region of

  7. Mitochondrial Iron Metabolism and Its Role in Neurodegeneration

    PubMed Central

    Horowitz, Maxx P.; Greenamyre, J. Timothy

    2011-01-01

    In addition to their well-established role in providing the cell with ATP, mitochondria are the source of iron-sulfur clusters (ISCs) and heme – prosthetic groups that are utilized by proteins throughout the cell in various critical processes. The post-transcriptional system that mammalian cells use to regulate intracellular iron homeostasis depends, in part, upon the synthesis of ISCs in mitochondria. Thus, proper mitochondrial function is crucial to cellular iron homeostasis. Many neurodegenerative diseases are marked by mitochondrial impairment, brain iron accumulation, and oxidative stress – pathologies that are inter-related. This review discusses the physiological role that mitochondria play in cellular iron homeostasis and, in so doing, attempts to clarify how mitochondrial dysfunction may initiate and/or contribute to iron dysregulation in the context of neurodegenerative disease. We review what is currently known about the entry of iron into mitochondria, the ways in which iron is utilized therein, and how mitochondria are integrated into the system of iron homeostasis in mammalian cells. Lastly, we turn to recent advances in our understanding of iron dysregulation in two neurodegenerative diseases (Alzheimer’s disease and Parkinson’s disease), and discuss the use of iron chelation as a potential therapeutic approach to neurodegenerative disease. PMID:20463401

  8. [Iron function and carcinogenesis].

    PubMed

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models.

  9. Macrophages and Iron Metabolism.

    PubMed

    Soares, Miguel P; Hamza, Iqbal

    2016-03-15

    Iron is a transition metal that due to its inherent ability to exchange electrons with a variety of molecules is essential to support life. In mammals, iron exists mostly in the form of heme, enclosed within an organic protoporphyrin ring and functioning primarily as a prosthetic group in proteins. Paradoxically, free iron also has the potential to become cytotoxic when electron exchange with oxygen is unrestricted and catalyzes the production of reactive oxygen species. These biological properties demand that iron metabolism is tightly regulated such that iron is available for core biological functions while preventing its cytotoxic effects. Macrophages play a central role in establishing this delicate balance. Here, we review the impact of macrophages on heme-iron metabolism and, reciprocally, how heme-iron modulates macrophage function.

  10. [Iron function and carcinogenesis].

    PubMed

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models. PMID:27455808

  11. The Organization of Controller Motifs Leading to Robust Plant Iron Homeostasis

    PubMed Central

    Agafonov, Oleg; Selstø, Christina Helen; Thorsen, Kristian; Xu, Xiang Ming; Drengstig, Tormod; Ruoff, Peter

    2016-01-01

    Iron is an essential element needed by all organisms for growth and development. Because iron becomes toxic at higher concentrations iron is under homeostatic control. Plants face also the problem that iron in the soil is tightly bound to oxygen and difficult to access. Plants have therefore developed special mechanisms for iron uptake and regulation. During the last years key components of plant iron regulation have been identified. How these components integrate and maintain robust iron homeostasis is presently not well understood. Here we use a computational approach to identify mechanisms for robust iron homeostasis in non-graminaceous plants. In comparison with experimental results certain control arrangements can be eliminated, among them that iron homeostasis is solely based on an iron-dependent degradation of the transporter IRT1. Recent IRT1 overexpression experiments suggested that IRT1-degradation is iron-independent. This suggestion appears to be misleading. We show that iron signaling pathways under IRT1 overexpression conditions become saturated, leading to a breakdown in iron regulation and to the observed iron-independent degradation of IRT1. A model, which complies with experimental data places the regulation of cytosolic iron at the transcript level of the transcription factor FIT. Including the experimental observation that FIT induces inhibition of IRT1 turnover we found a significant improvement in the system’s response time, suggesting a functional role for the FIT-mediated inhibition of IRT1 degradation. By combining iron uptake with storage and remobilization mechanisms a model is obtained which in a concerted manner integrates iron uptake, storage and remobilization. In agreement with experiments the model does not store iron during its high-affinity uptake. As an iron biofortification approach we discuss the possibility how iron can be accumulated even during high-affinity uptake. PMID:26800438

  12. Cellular iron metabolism.

    PubMed

    Ponka, P

    1999-03-01

    Iron is essential for oxidation-reduction catalysis and bioenergetics, but unless appropriately shielded, iron plays a key role in the formation of toxic oxygen radicals that can attack all biological molecules. Hence, specialized molecules for the acquisition, transport (transferrin), and storage (ferritin) of iron in a soluble nontoxic form have evolved. Delivery of iron to most cells, probably including those of the kidney, occurs following the binding of transferrin to transferrin receptors on the cell membrane. The transferrin-receptor complexes are then internalized by endocytosis, and iron is released from transferrin by a process involving endosomal acidification. Cellular iron storage and uptake are coordinately regulated post-transcriptionally by cytoplasmic factors, iron-regulatory proteins 1 and 2 (IRP-1 and IRP-2). Under conditions of limited iron supply, IRP binding to iron-responsive elements (present in 5' untranslated region of ferritin mRNA and 3' untranslated region of transferrin receptor mRNA) blocks ferritin mRNA translation and stabilizes transferrin receptor mRNA. The opposite scenario develops when iron in the transit pool is plentiful. Moreover, IRP activities/levels can be affected by various forms of "oxidative stress" and nitric oxide. The kidney also requires iron for metabolic processes, and it is likely that iron deficiency or excess can cause disturbed function of kidney cells. Transferrin receptors are not evenly distributed throughout the kidney, and there is a cortical-to-medullary gradient in heme biosynthesis, with greatest activity in the cortex and least in the medulla. This suggests that there are unique iron/heme metabolism features in some kidney cells, but the specific aspects of iron and heme metabolism in the kidney are yet to be explained.

  13. The Evidence-Based Evaluation of Iron Deficiency Anemia.

    PubMed

    Hempel, Eliana V; Bollard, Edward R

    2016-09-01

    Anemia is a prevalent disease with multiple possible etiologies and resultant complications. Iron deficiency anemia is a common cause of anemia and is typically due to insufficient intake, poor absorption, or overt or occult blood loss. Distinguishing iron deficiency from other causes of anemia is integral to initiating the appropriate treatment. In addition, identifying the underlying cause of iron deficiency is also necessary to help guide management of these patients. We review the key components to an evidence-based, cost-conscious evaluation of suspected iron deficiency anemia. PMID:27542426

  14. Iron deficiency anaemia.

    PubMed

    Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent

    2016-02-27

    Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.

  15. Iron deficiency anaemia.

    PubMed

    Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent

    2016-02-27

    Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment. PMID:26314490

  16. The ubiquity of iron.

    PubMed

    Frey, Perry A; Reed, George H

    2012-09-21

    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

  17. The ubiquity of iron.

    PubMed

    Frey, Perry A; Reed, George H

    2012-09-21

    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.

  18. Iron-sulfur clusters: why iron?

    PubMed

    Jensen, Kasper P

    2006-08-01

    This communication addresses a simple question by means of density functional calculations: Why is iron used as the metal in iron-sulfur clusters? While there may be several answers to this question, it is shown here that one feature - the well-defined inner-sphere reorganization energy of self-exchange electron transfer - is very much favored in iron-sulfur clusters as opposed to metal substituted analogues of Mn, Co, Ni, and Cu. Furthermore, the conclusion holds for both 1Fe and 2Fe type iron-sulfur clusters. The results show that only iron provides a small inner-sphere reorganization energy of 21 kJ/mol in 1Fe (rubredoxin) and 46 kJ/mol in 2Fe (ferredoxin) models, whereas other metal ions exhibit values in the range 57-135 kJ/mol (1Fe) and 94-140 kJ/mol (2Fe). This simple result provides an important, although partial, explanation why iron alone is used in this type of clusters. The results can be explained by simple orbital rules of electron transfer, which state that the occupation of anti-bonding orbitals should not change during the redox reactions. This rule immediately suggests good and poor electron carriers.

  19. Iron and iron-based alloys for temporary cardiovascular applications.

    PubMed

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

    2015-03-01

    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.

  20. Iron and Stony-iron Meteorites

    NASA Astrophysics Data System (ADS)

    Haack, H.; McCoy, T. J.

    2003-12-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich sampling of the deep interiors of differentiated asteroids.Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar to that continuing on Earth - although on much smaller length- and timescales - with melting of the metal and silicates, differentiation into core, mantle, and crust, and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth and other terrestrial planets. This fact has been recognized since the work of Chladni (1794), who argued that stony-iron meteorites must have originated in outer space and fallen during fireballs and that they provide our closest analogue to the material that comprises our own planet's core. This chapter deals with our current knowledge of these meteorites. How did they form? What can they tell us about the early evolution of the solar system and its solid bodies? How closely do they resemble the materials from planetary interiors? What do we know and don't we know?Iron and stony-iron meteorites constitute ˜6% of meteorite falls (Grady, 2000). Despite their scarcity among falls, iron meteorites are our only samples of ˜75 of the ˜135 asteroids from which meteorites originate ( Keil et al., 1994; Scott, 1979; Meibom and Clark, 1999; see also Chapter 1.05), suggesting that both differentiated asteroids and the geologic processes that produced them were common.Despite the highly evolved nature of iron and stony-iron meteorites, their chemistry provides important

  1. Brain iron homeostasis.

    PubMed

    Moos, Torben

    2002-11-01

    Iron is essential for virtually all types of cells and organisms. The significance of the iron for brain function is reflected by the presence of receptors for transferrin on brain capillary endothelial cells. The transport of iron into the brain from the circulation is regulated so that the extraction of iron by brain capillary endothelial cells is low in iron-replete conditions and the reverse when the iron need of the brain is high as in conditions with iron deficiency and during development of the brain. Whereas there is good agreement that iron is taken up by means of receptor-mediated uptake of iron-transferrin at the brain barriers, there are contradictory views on how iron is transported further on from the brain barriers and into the brain extracellular space. The prevailing hypothesis for transport of iron across the BBB suggests a mechanism that involves detachment of iron from transferrin within barrier cells followed by recycling of apo-transferrin to blood plasma and release of iron as non-transferrin-bound iron into the brain interstitium from where the iron is taken up by neurons and glial cells. Another hypothesis claims that iron-transferrin is transported into the brain by means of transcytosis through the BBB. This thesis deals with the topic "brain iron homeostasis" defined as the attempts to maintain constant concentrations of iron in the brain internal environment via regulation of iron transport through brain barriers, cellular iron uptake by neurons and glia, and export of iron from brain to blood. The first part deals with transport of iron-transferrin complexes from blood to brain either by transport across the brain barriers or by uptake and retrograde axonal transport in motor neurons projecting beyond the blood-brain barrier. The transport of iron and transport into the brain was examined using radiolabeled iron-transferrin. Intravenous injection of [59Fe-125]transferrin led to an almost two-fold higher accumulation of 59Fe than of

  2. Mechanisms of mammalian iron homeostasis.

    PubMed

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

    2012-07-24

    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 the 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.

  3. IRON IN MULTIPLE MYELOMA

    PubMed Central

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

    2013-01-01

    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

  4. Cellular iron transport.

    PubMed

    Garrick, Michael D; Garrick, Laura M

    2009-05-01

    Iron has a split personality as an essential nutrient that also has the potential to generate reactive oxygen species. We discuss how different cell types within specific tissues manage this schizophrenia. The emphasis in enterocytes is on regulating the body's supply of iron by regulating transport into the blood stream. In developing red blood cells, adaptations in transport manage the body's highest flux of iron. Hepatocytes buffer the body's stock of iron. Macrophage recycle the iron from effete red cells among other iron management tasks. Pneumocytes provide a barrier to prevent illicit entry that, when at risk of breaching, leads to a need to handle the dangers in a fashion essentially shared with macrophage. We also discuss or introduce cell types including renal cells, neurons, other brain cells, and more where our ignorance, currently still vast, needs to be removed by future research. PMID:19344751

  5. Austempered Ductile Iron Machining

    NASA Astrophysics Data System (ADS)

    Pilc, Jozef; Šajgalík, Michal; Holubják, Jozef; Piešová, Marianna; Zaušková, Lucia; Babík, Ondrej; Kuždák, Viktor; Rákoci, Jozef

    2015-12-01

    This article deals with the machining of cast iron. In industrial practice, Austempered Ductile Iron began to be used relatively recently. ADI is ductile iron that has gone through austempering to get improved properties, among which we can include strength, wear resistance or noise damping. This specific material is defined also by other properties, such as high elasticity, ductility and endurance against tenigue, which are the properties, that considerably make the tooling characteristic worse.

  6. Plea for Iron Astrochemistry

    SciTech Connect

    Mostefaoui, T. A.; Benmerad, B.; Kerkar, M.

    2010-10-31

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

  7. Iron deficiency: beyond anemia.

    PubMed

    Yadav, Dinesh; Chandra, Jagdish

    2011-01-01

    Iron deficiency is the most common nutritional disorder affecting at least one third of world's population. Though anemia is common manifestation of iron deficiency, other effects of iron deficiency on various tissues, organs and systems are usually under recognized. Impaired brain development and cognitive, behavioural and psychomotor impairment are most worrisome manifestations of iron deficiency. Studies have demonstrated that some of these changes occurring during period of brain growth spurt (<2 years age) may be irreversible. Association of iron deficiency with febrile seizures, pica, breath holding spells, restless leg syndrome and thrombosis is increasingly being recognized. Impaired cell-mediated immunity and bactericidal function are generally noted in iron-deficient persons; however, the findings are inconsistent. Despite proven reversible functional immunological defects in vitro studies, a clinically important relationship between states of iron deficiency and susceptibility to infections remains controversial. Studies from malaria endemic regions have reported increased incidence of malaria in association with iron supplementation. These and some other aspects of iron deficiency are reviewed in this article.

  8. Physics of iron

    SciTech Connect

    Anderson, O.

    1993-10-01

    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.

  9. Physiology of Iron Metabolism

    PubMed Central

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

    2014-01-01

    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

  10. Physics of iron

    NASA Astrophysics Data System (ADS)

    Anderson, O.

    1993-10-01

    This volume comprises papers presented at the AIRAPT Conference, 28 June - 2 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 were 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.

  11. 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

  12. Iron metabolism and iron supplementation in cancer patients.

    PubMed

    Ludwig, Heinz; Evstatiev, Rayko; Kornek, Gabriela; Aapro, Matti; Bauernhofer, Thomas; Buxhofer-Ausch, Veronika; Fridrik, Michael; Geissler, Dietmar; Geissler, Klaus; Gisslinger, Heinz; Koller, Elisabeth; Kopetzky, Gerhard; Lang, Alois; Rumpold, Holger; Steurer, Michael; Kamali, Houman; Link, Hartmut

    2015-12-01

    Iron deficiency and iron deficiency-associated anemia are common complications in cancer patients. Most iron deficient cancer patients present with functional iron deficiency (FID), a status with adequate storage iron, but insufficient iron supply for erythroblasts and other iron dependent tissues. FID is the consequence of the cancer-associated cytokine release, while in absolute iron deficiency iron stores are depleted resulting in similar but often more severe symptoms of insufficient iron supply. Here we present a short review on the epidemiology, pathophysiology, diagnosis, clinical symptoms, and treatment of iron deficiency in cancer patients. Special emphasis is given to intravenous iron supplementation and on the benefits and limitations of different formulations. Based on these considerations and recommendations from current international guidelines we developed recommendations for clinical practice and classified the level of evidence and grade of recommendation according to the principles of evidence-based medicine.

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

    SciTech Connect

    2010-10-01

    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.

  14. Benefits and harms of iron supplementation in iron-deficient and iron-sufficient children.

    PubMed

    Domellöf, Magnus

    2010-01-01

    Due to high iron requirements, young children are at risk for iron deficiency anemia. Iron supplements are therefore often recommended, especially since iron deficiency anemia in children is associated with poor neurodevelopment. However, in contrast to most other nutrients, excess iron cannot be excreted by the human body and it has recently been suggested that excessive iron supplementation of young children may have adverse effects on growth, risk of infections, and even on cognitive development. Recent studies support that iron supplements are beneficial in iron-deficient children but there is a risk of adverse effects in those who are iron replete. In populations with a low prevalence of iron deficiency, general supplementation should therefore be avoided. Iron-fortified foods can still be generally recommended since they seem to be safer than medicinal iron supplements, but the level of iron fortification should be limited. General iron supplementation is recommended in areas with a high prevalence of iron deficiency, with the exception of malarious areas where a cautious supplementation approach needs to be adopted, based either on screening or a combination of iron supplements and infection control measures. More studies are urgently needed to better determine the risks and benefits of iron supplementation and iron-fortified foods given to iron-deficient and iron-sufficient children.

  15. Neurodegeneration with Brain Iron Accumulation

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Neurodegeneration with Brain Iron Accumulation Information Page Synonym(s): Hallervorden-Spatz Disease, ... done? Clinical Trials Organizations What is Neurodegeneration with Brain Iron Accumulation? Neurodegeneration with brain iron accumulation (NBIA) ...

  16. [Iron deficiency and digestive disorders].

    PubMed

    Cozon, G J N

    2014-11-01

    Iron deficiency anemia still remains problematic worldwide. Iron deficiency without anemia is often undiagnosed. We reviewed, in this study, symptoms and syndromes associated with iron deficiency with or without anemia: fatigue, cognitive functions, restless legs syndrome, hair loss, and chronic heart failure. Iron is absorbed through the digestive tract. Hepcidin and ferroportin are the main proteins of iron regulation. Pathogenic micro-organisms or intestinal dysbiosis are suspected to influence iron absorption.

  17. Iron nutrition in adolescence.

    PubMed

    Mesías, Marta; Seiquer, Isabel; Navarro, M Pilar

    2013-01-01

    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 adequate iron bioavailability to favor element utilization and thus be sufficient for needs at this stage of life. Currently, many adolescents consume monotonous and unbalanced diets which may limit mineral intake and/or bioavailability, leading to iron deficiency and, consequently, to ferropenic anemia, a nutritional deficit of worldwide prevalence. Iron deficiency, apart from provoking important physiological repercussions, can adversely affect adolescents' cognitive ability and behavior. Accordingly, promoting the consumption of a varied, adjusted, and balanced diet by adolescents will facilitate iron utilization, benefiting their health both at present and in adulthood. This review discusses how physiological changes during adolescence can cause iron requirements to increase. Consequently, it is important that diet should contribute an appropriate amount of this mineral and, moreover, with an adequate bioavailability to satisfy needs during this special period of life.

  18. Thin Wall Iron Castings

    SciTech Connect

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

    2001-10-31

    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.

  19. Microbes: mini iron factories.

    PubMed

    Joshi, Kumar Batuk

    2014-12-01

    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

  20. Microbes: mini iron factories.

    PubMed

    Joshi, Kumar Batuk

    2014-12-01

    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.

  1. Iron studies in hemophilia

    SciTech Connect

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

    1981-12-01

    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.

  2. Iron economy in Chlamydomonas reinhardtii

    PubMed Central

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

    2013-01-01

    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

  3. Iron piston having selectively hardened ring groove

    SciTech Connect

    Brann, D.E.; Lindsay, J.E.

    1987-02-17

    This patent describes a long-lasting cast iron piston body for an internal combustion engine, the piston body comprising a generally cylindrical sidewall and having an annular groove in the wall encircling the body for receiving a piston ring. The groove is defined by opposed faces that intersect the wall, the piston body being composed predominantly of gray iron characterized by an as-cast pearlitic microstructure, the groove face comprising an integrally cast, selectively hardened iron band adjacent the piston sidewall and encircling the piston body. The band is characterized by a martensitic microstructure substantially harder than the pearlitic microstructure and is effective to reduce wear resulting from a piston ring seated within the groove.

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

    PubMed

    Yee, Jerry

    2010-02-01

    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

  5. 21 CFR 310.518 - Drug products containing iron or iron salts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Drug products containing iron or iron salts. 310... Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as...) that contains iron or iron salts for use as an iron source shall bear the following statement:...

  6. 21 CFR 310.518 - Drug products containing iron or iron salts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Drug products containing iron or iron salts. 310... Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as...) that contains iron or iron salts for use as an iron source shall bear the following statement:...

  7. 21 CFR 310.518 - Drug products containing iron or iron salts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Drug products containing iron or iron salts. 310... Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as...) that contains iron or iron salts for use as an iron source shall bear the following statement:...

  8. 21 CFR 310.518 - Drug products containing iron or iron salts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Drug products containing iron or iron salts. 310... Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as...) that contains iron or iron salts for use as an iron source shall bear the following statement:...

  9. Molecular control of vertebrate iron homeostasis by iron regulatory proteins

    PubMed Central

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

    2008-01-01

    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

  10. Iron overload and hematologic malignancies.

    PubMed

    Franchini, Massimo; Veneri, Dino

    2004-01-01

    Although iron is essential for cell replication and survival, an increase of body iron stores has been implicated in the development of cancer. However, while the association between iron overload and hepatocellular carcinoma is well documented, the relationship with nonhepatocellular malignancies remains ill-defined. In this review, we briefly report the present knowledge regarding the association between iron overload and hematologic malignancies.

  11. Coal desulfurization. [using iron pentacarbonyl

    NASA Technical Reports Server (NTRS)

    Hsu, G. C. (Inventor)

    1979-01-01

    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.

  12. [Iron and liver disease].

    PubMed

    Miyanishi, Koji; Kato, Junji

    2016-07-01

    Free iron in the liver is believed to facilitate the formation of reactive oxygen species (ROS), including hydroxyl radicals (*OH), which cause oxidative damage of numerous cellular components such as lipids, proteins, and nucleic acids, and also upregulate collagen synthesis. The *OH radical is known to generate promutagenic bases such as 8-hydroxy-2-deoxyguanosine (8-OHdG). In cases with chronic hepatitis C, long-term iron reduction therapy reduced the activity of hepatitis, suppressed fibrosis, and prevented hepatocarcinogenesis. In nonalcoholic steatohepatitis (NASH) livers, hepatic iron accumulation as well as oxidative DNA damage significantly increased. Humoral factor(s) in NASH serum may upregulate DMT1 expression in small intestine. Iron reduction therapy for NASH patients has a potential to reduce disease activity as well as hepatic oxidative damage. PMID:27455806

  13. Iron in diet

    MedlinePlus

    ... found in lamb, pork, and shellfish. Iron from vegetables, fruits, grains, and supplements is harder for the ... and peas Kidney beans Seeds: Almonds Brazil nuts Vegetables: Broccoli Spinach Kale Collards Asparagus Dandelion greens Whole ...

  14. Iron Sucrose Injection

    MedlinePlus

    ... often you receive iron sucrose injection and your total number of doses based on your condition and ... hands or feet; swelling of the hands, feet, ankles, or lower legs; loss of consciousness; or seizures. ...

  15. Iron deficiency and iron deficiency anemia in women.

    PubMed

    Coad, Jane; Pedley, Kevin

    2014-01-01

    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.

  16. Scotland's first iron lung.

    PubMed

    Porter, I A; Williams, M J

    1997-08-01

    The history of artificial ventilation and the development of the iron lung in the USA by Drinker and his colleagues is discussed. The building and use of an iron lung by Dr R G Henderson in Aberdeen in 1933 is described. The development of other types of ventilator in the UK is recorded and the circumstances whereby positive pressure ventilation was introduced in Denmark in 1952 is outlined. PMID:9507591

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

    PubMed Central

    2007-01-01

    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

  18. 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...

  19. Iron-Based Superconductors as topological matter

    NASA Astrophysics Data System (ADS)

    Hu, Jiangping

    We show the existence of non-trivial topological properties in Iron-based superconductors. Several examples are provided, including (1) the single layer FeSe grown on SrTiO3 substrate, in which an topological insulator phase exists due to the band inversion at M point; (2) CaFeAs2, a staggered intercalation compound that integrates both quantum spin hall and superconductivity in which the nontrivial topology stems from the chain-like As layers away from FeAs layers; (3) the Fe(Te,Se) thin films in which the nontrivial Z2 topological invariance originates from the parity exchange at Γ point that is controlled by the Te(Se) height; (4 nontrivial topology that is driven by the nematic order in FeSe. These results lay ground for integrating high Tc superconductivity with topological properties to realize new emergent phenomena, such as majorana particles, in iron-based high temperature superconductors

  20. Topological properties in Iron-Based Superconductors

    NASA Astrophysics Data System (ADS)

    Hu, Jiangping; Hao, Ningning; Wu, X. X.

    2015-03-01

    We show the existence of non-trivial topological properties in Iron-based superconductors. Several examples are provided, including (1) the single layer FeSe grown on SrTiO3 substrate, in which an topological insulator phase exists due to the band inversion at M point; (2) CaFeAs2, a staggered intercalation compound that integrates both quantum spin hall and superconductivity in which the nontrivial topology stems from the chain-like As layers away from FeAs layers; (3) the Fe(Te,Se) thin films in which the nontrivial Z2 topological invariance originates from the parity exchange at ? point that is controlled by the Te(Se) height. These results lay ground for integrating high Tc superconductivity with topological properties to realize new emergent phenomena, such as majorana particles, in iron-based high temperature superconductors. The work is supported by NSFC and the Ministry of Science and Technology of China.

  1. Mining iron: iron uptake and transport in plants.

    PubMed

    Kim, Sun A; Guerinot, Mary Lou

    2007-05-25

    Iron uptake in plants is highly regulated in order to supply amounts sufficient for optimal growth while preventing excess accumulation. In response to iron deficiency, plants induce either reduction-based or chelation-based mechanisms to enhance iron uptake from the soil. Genes involved in each mechanism have been identified from various model plants including Arabidopsis and rice. Iron transport within plants is also tightly controlled. New information has emerged on transporters that play a role in xylem loading and phloem loading/unloading of iron, and on the iron chelators involved in iron homeostasis. Some of the components regulating iron deficiency responses also have been elucidated, demonstrating that iron dependent gene regulation occurs at both the transcriptional and post-transcriptional levels. PMID:17485078

  2. Plant cell nucleolus as a hot spot for iron.

    PubMed

    Roschzttardtz, Hannetz; Grillet, Louis; Isaure, Marie-Pierre; Conéjéro, Geneviève; Ortega, Richard; Curie, Catherine; Mari, Stéphane

    2011-08-12

    Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.

  3. Iron Absorption in Drosophila melanogaster

    PubMed Central

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  4. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  5. [Iron deficiency and iron deficiency anemia are global health problems].

    PubMed

    Dahlerup, Jens; Lindgren, Stefan; Moum, Björn

    2015-03-10

    Iron deficiency and iron deficiency anemia are global health problems leading to deterioration in patients' quality of life and more serious prognosis in patients with chronic diseases. The cause of iron deficiency and anemia is usually a combination of increased loss and decreased intestinal absorption and delivery from iron stores due to inflammation. Oral iron is first line treatment, but often hampered by intolerance. Intravenous iron is safe, and the preferred treatment in patients with chronic inflammation and bowel diseases. The goal of treatment is normalisation of hemoglobin concentration and recovery of iron stores. It is important to follow up treatment to ensure that these objectives are met and also long-term in patients with chronic iron loss and/or inflammation to avoid recurrence of anemia.

  6. Mammalian iron metabolism and its control by iron regulatory proteins☆

    PubMed Central

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

    2013-01-01

    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

  7. 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

  8. Iron Meteorite on Mars

    NASA Technical Reports Server (NTRS)

    2005-01-01

    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.

  9. Iron in Infection and Immunity

    PubMed Central

    Cassat, James E.; Skaar, Eric P.

    2013-01-01

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

  10. Iron in infection and immunity.

    PubMed

    Cassat, James E; Skaar, Eric P

    2013-05-15

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

  11. Nonbiological fractionation of iron isotopes

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Roe, J. E.; Barling, J.; Nealson, K. H.

    2000-01-01

    Laboratory experiments demonstrate that iron isotopes can be chemically fractionated in the absence of biology. Isotopic variations comparable to those seen during microbially mediated reduction of ferrihydrite are observed. Fractionation may occur in aqueous solution during equilibration between inorganic iron complexes. These findings provide insight into the mechanisms of iron isotope fractionation and suggest that nonbiological processes may contribute to iron isotope variations observed in sediments.

  12. Iron excretion in iron dextran-overloaded mice

    PubMed Central

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

    2014-01-01

    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

  13. Formation and occurrence of biogenic iron-rich minerals

    NASA Astrophysics Data System (ADS)

    Fortin, Danielle; Langley, Sean

    2005-09-01

    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

  14. Iron deficiency and cognitive functions

    PubMed Central

    Jáuregui-Lobera, Ignacio

    2014-01-01

    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

  15. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron,...

  16. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron, elemental. 184.1375 Section 184.1375 Food and... Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and...

  17. Development of iron aluminides

    SciTech Connect

    Viswanathan, S.; Sikka, V.K.; Andleigh, V.K.

    1995-06-01

    The primary reason for the poor room-temperature ductility of Fe{sub 3}Al-based alloys is generally accepted to be environmental embrittlement due to hydrogen produced by the reaction of aluminum with water vapor present in the test atmosphere. In the as-cast condition, another possible reason for the low room-temperature ductility is the large grain size (0.5 to 3 mm) of the cast material. While recent studies on iron aluminides in the wrought condition have led to higher room-temperature ductility and increased high-temperature strength, limited studies have been conducted on iron aluminides in the as-cast condition. The purpose of this study was to induce grain refinement of the as-cast alloy through alloying additions to the melt and study the effect on room-temperature ductility as measured by the strain corresponding to the maximum stress obtained in a three-point bend test. A base charge of Fe-28% Al-5% Cr alloy was used; as in previous studies this ternary alloy exhibited the highest tensile ductility of several alloys tested. Iron aluminide alloys are being considered for many structural uses, especially for applications where their excellent corrosion resistance is needed. Several alloy compositions developed at ORNL have been licensed to commercial vendors for development of scale-up procedures. With the licensees and other vendors, several applications for iron aluminides are being pursued.

  18. Iron dominated magnets

    SciTech Connect

    Fischer, G.E.

    1985-07-01

    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.

  19. Iron, transferrin and myelinogenesis

    NASA Astrophysics Data System (ADS)

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

    2003-09-01

    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.

  20. Iron ERRs with Salmonella.

    PubMed

    Fang, Ferric C; Weiss, Günter

    2014-05-14

    The hormone hepcidin promotes iron sequestration by macrophages. A recent study by Kim et al. (2014) implicates the orphan receptor ERRγ (estrogen-related receptor γ) in the regulation of hepcidin production and suggests that targeting the ERRγ-hepcidin axis may be beneficial during infection with the facultative intracellular pathogen Salmonella.

  1. Taking iron supplements

    MedlinePlus

    ... J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Related MedlinePlus Health Topics Iron Browse the Encyclopedia A.D.A. ...

  2. Extracting Iron from Cereal.

    ERIC Educational Resources Information Center

    Katz, David A.

    1992-01-01

    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)

  3. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    NASA Astrophysics Data System (ADS)

    Török, B.; Thiele, A.

    2013-12-01

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

  4. Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction.

    PubMed

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

    2006-10-01

    Iron (Fe) has long been a recognized physiological requirement for life, yet for many microorganisms that persist in water, soils and sediments, its role extends well beyond that of a nutritional necessity. Fe(II) can function as an electron source for iron-oxidizing microorganisms under both oxic and anoxic conditions and Fe(III) can function as a terminal electron acceptor under anoxic conditions for iron-reducing microorganisms. Given that iron is the fourth most abundant element in the Earth's crust, iron redox reactions have the potential to support substantial microbial populations in soil and sedimentary environments. As such, biological iron apportionment has been described as one of the most ancient forms of microbial metabolism on Earth, and as a conceivable extraterrestrial metabolism on other iron-mineral-rich planets such as Mars. Furthermore, the metabolic versatility of the microorganisms involved in these reactions has resulted in the development of biotechnological applications to remediate contaminated environments and harvest energy.

  5. Nutritional iron deficiency: the role of oral iron supplementation.

    PubMed

    Lachowicz, J I; Nurchi, V M; Fanni, D; Gerosa, C; Peana, M; Zoroddu, M A

    2014-01-01

    Nutritional iron deficiency represents a relevant health problem mainly in developing countries. Children and pregnant women represent the main target of this disease, and the low amount of bio-available iron mostly depends on plant-based diets. Iron deficiency may have serious consequences, with severe impairment of the immune function leading to infectious diseases. The brain development in embryos and fetuses during gestation can be greatly affected by iron deficiency of the mother with heavy outcomes on the cognition status of children. A better understanding of molecular pathways involved in iron absorption and metabolism are the basis for new strategies for developing a therapy for iron deficiency. Different therapeutic strategies are summarized, and iron fortification appears the best tool.

  6. Iron Aluminide Composites

    SciTech Connect

    Schneibel, J.H.

    1998-11-20

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength at elevated temperatures (1073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a mile of mixtures. Interestingly, sufficiently thin (< 1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminizes, environmental embrittlement is dramatically reduced in iron aluminide composites.

  7. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  8. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  9. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  10. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  11. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  12. Protein adducts of malondialdehyde and 4-hydroxynonenal in livers of iron loaded rats: quantitation and localization.

    PubMed

    Khan, M Firoze; Wu, Xiaohong; Tipnis, Ulka R; Ansari, G A S; Boor, Paul J

    2002-05-01

    Pathophysiological mechanisms for hepatocellular injury, fibrosis and/or cirrhosis in hepatic iron overload are poorly understood. An increase in intracellular transit pool of iron can catalyze peroxidation of lipids to produce reactive aldehydes such as malondialdehyde (MDA) and 4-hydroxynonenal (HNE). Covalent binding of such lipid aldehydes with proteins may cause impairment in cellular function and integrity. This investigation was focused on quantitative determination of MDA and HNE-protein adducts, and to establish a correlation between iron deposition and formation and localization of MDA and HNE-protein adducts, using immunohistochemistry. To achieve iron overload, male SD rats were fed a 2.5% carbonyl iron-supplemented diet for six weeks, while control animals received standard diet. Total iron as well as low molecular weight chelatable iron (LMWC-Fe) in the hepatic tissue of rats fed the iron supplemented diet increased significantly ( approximately 14- and approximately 15-fold, respectively). Quantitative ELISA for MDA-and HNE-protein adducts showed remarkable increases of 186 and 149%, respectively, in the liver homogenates of rats fed the iron-supplemented diet. Sections of liver stained for iron showed striking iron deposits in periportal (zone 1) hepatocytes, which was less dramatic in midzonal (zone 2) cells. Livers from iron-loaded rats showed strong, diffuse staining for both MDA and HNE adducts, which was highly pronounced in centrilobular (zone 3) hepatocytes, but was also evident in midzonal cells (zone 2). The demonstration of greater formation of both MDA and HNE-protein adducts provides evidence of iron-catalyzed lipid peroxidation in vivo. Although in this model of iron overload there was no evidence of tissue injury, our results provide an account of some of the initiating factors or early molecular events in hepatocellular damage that may lead to the pathological manifestations seen in chronic iron overload.

  13. Iron status in the elderly.

    PubMed

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

    2014-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  15. Degradation of chlorofluorocarbons using granular iron and bimetallic irons.

    PubMed

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

    2014-03-01

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

  16. Degradation of chlorofluorocarbons using granular iron and bimetallic irons.

    PubMed

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

    2014-03-01

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

  17. Flare Plasma Iron Abundance

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    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.

  18. Iron homoeostasis in rheumatic disease.

    PubMed

    Baker, Joshua F; Ghio, Andrew J

    2009-11-01

    Iron is critical in nearly all cell functions and the ability of a cell, tissue and organism to procure this metal is obligatory for survival. Iron is necessary for normal immune function, and relative iron deficiency is associated with mild immunosuppression. Concentrations of this metal in excess of those required for function can present both an oxidative stress and elevate risks for infection. As a result, the human has evolved to have a complex mechanism of regulating iron and limiting its availability. This homoeostasis can be disrupted. Autoimmune diseases and gout often present with abnormal iron homoeostasis, thus supporting a participation of the metal in these injuries. We review the role of iron in normal immune function and discuss both clinical evidence of altered iron homoeostasis in autoimmune diseases and gout as well as possible implications of both depletion and supplementation of this metal in this patient population. We conclude that altered iron homoeostasis may represent a purposeful response to inflammation that could have theoretical anti-inflammatory benefits. We encourage physicians to avoid routine iron supplementation in those without depleted iron stores.

  19. Iron homeostasis and eye disease

    PubMed Central

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

    2009-01-01

    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

  20. Iron deficiency and cardiovascular disease.

    PubMed

    von Haehling, Stephan; Jankowska, Ewa A; van Veldhuisen, Dirk J; Ponikowski, Piotr; Anker, Stefan D

    2015-11-01

    Iron deficiency affects up to one-third of the world's population, and is particularly common in elderly individuals and those with certain chronic diseases. Iron excess can be detrimental in cardiovascular illness, and research has now also brought anaemia and iron deficiency into the focus of cardiovascular medicine. Data indicate that iron deficiency has detrimental effects in patients with coronary artery disease, heart failure (HF), and pulmonary hypertension, and possibly in patients undergoing cardiac surgery. Around one-third of all patients with HF, and more than one-half of patients with pulmonary hypertension, are affected by iron deficiency. Patients with HF and iron deficiency have shown symptomatic improvements from intravenous iron administration, and some evidence suggests that these improvements occur irrespective of the presence of anaemia. Improved exercise capacity has been demonstrated after iron administration in patients with pulmonary hypertension. However, to avoid iron overload and T-cell activation, it seems that recipients of cardiac transplantations should not be treated with intravenous iron preparations.

  1. Iron acquisition in Vibrio cholerae.

    PubMed

    Wyckoff, Elizabeth E; Mey, Alexandra R; Payne, Shelley M

    2007-06-01

    Vibrio cholerae, the causative agent of cholera, has an absolute requirement for iron and must obtain this element in the human host as well as in its varied environmental niches. It has multiple systems for iron acquisition, including the TonB-dependent transport of heme, the endogenous siderophore vibriobactin and several siderophores that are produced by other microorganisms. There is also a Feo system for the transport of ferrous iron and an ABC transporter, Fbp, which transports ferric iron. There appears to be at least one additional high affinity iron transport system that has not yet been identified. In iron replete conditions, iron acquisition genes are repressed by Fur. Fur also represses the synthesis of a small, regulatory RNA, RyhB, which negatively regulates genes for iron-containing proteins involved in the tricarboxylic acid cycle and respiration as well as genes for motility and chemotaxis. The redundancy in iron transport systems has made it more difficult to determine the role of individual systems in vivo and in vitro, but it may reflect the overall importance of iron in the growth and survival of V. cholerae.

  2. Iron absorption and transport-an update.

    PubMed

    Conrad, M E; Umbreit, J N

    2000-08-01

    Iron is vital for all living organisms. However, excess iron is hazardous because it produces free radical formation. Therefore, iron absorption is carefully regulated to maintain an equilibrium between absorption and body loss of iron. In countries where heme is a significant part of the diet, most body iron is derived from dietary heme iron because heme binds few of the luminal intestinal iron chelators that inhibit absorption of non-heme iron. Uptake of luminal heme into enterocytes occurs as a metalloporphyrin. Intracellularly, iron is released from heme by heme oxygenase so that iron leaves the enterocyte to enter the plasma as non-heme iron. Ferric iron is absorbed via a beta(3) integrin and mobilferrin (IMP) pathway that is not shared with other nutritional metals. Ferrous iron uptake is facilitated by DMT-1 (Nramp-2, DCT-1) in a pathway shared with manganese. Other proteins were recently described which are believed to play a role in iron absorption. SFT (Stimulator of Iron Transport) is postulated to facilitate both ferric and ferrous iron uptake, and Hephaestin is thought to be important in transfer of iron from enterocytes into the plasma. The iron concentration within enterocytes reflects the total body iron and either upregulates or satiates iron-binding sites on regulatory proteins. Enterocytes of hemochromatotics are iron-depleted similarly to the absorptive cells of iron-deficient subjects. Iron depletion, hemolysis, and hypoxia each can stimulate iron absorption. In non-intestinal cells most iron uptake occurs via either the classical clathrin-coated pathway utilizing transferrin receptors or the poorly defined transferrin receptor independent pathway. Non-intestinal cells possess the IMP and DMT-1 pathways though their role in the absence of iron overload is unclear. This suggests that these pathways have intracellular functions in addition to facilitating iron uptake.

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

    PubMed

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

    2015-04-01

    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

  4. Microbial reduction of iron ore

    DOEpatents

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

    1989-11-14

    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.

  5. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    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.

  6. The Irony of Iron – Biogenic Iron Oxides as an Iron Source to the Ocean

    PubMed Central

    Emerson, David

    2016-01-01

    Primary productivity in at least a third of the sunlit open ocean is thought to be iron-limited. Primary sources of dissolved iron (dFe) to the ocean are hydrothermal venting, flux from the sediments along continental margins, and airborne dust. This article provides a general review of sources of hydrothermal and sedimentary iron to the ocean, and speculates upon the role that iron-cycling microbes play in controlling iron dynamics from these sources. Special attention is paid to iron-oxidizing bacteria (FeOB) that live by oxidizing iron and producing biogenic iron oxides as waste products. The presence and ubiquity of FeOB both at hydrothermal systems and in sediments is only beginning to be appreciated. The biogenic oxides they produce have unique properties that could contribute significantly to the dynamics of dFe in the ocean. Changes in the physical and chemical characteristics of the ocean due to climate change and ocean acidification will undoubtedly impact the microbial iron cycle. A better understanding of the contemporary role of microbes in the iron cycle will help in predicting how these changes could ultimately influence marine primary productivity. PMID:26779157

  7. The Irony of Iron - Biogenic Iron Oxides as an Iron Source to the Ocean.

    PubMed

    Emerson, David

    2015-01-01

    Primary productivity in at least a third of the sunlit open ocean is thought to be iron-limited. Primary sources of dissolved iron (dFe) to the ocean are hydrothermal venting, flux from the sediments along continental margins, and airborne dust. This article provides a general review of sources of hydrothermal and sedimentary iron to the ocean, and speculates upon the role that iron-cycling microbes play in controlling iron dynamics from these sources. Special attention is paid to iron-oxidizing bacteria (FeOB) that live by oxidizing iron and producing biogenic iron oxides as waste products. The presence and ubiquity of FeOB both at hydrothermal systems and in sediments is only beginning to be appreciated. The biogenic oxides they produce have unique properties that could contribute significantly to the dynamics of dFe in the ocean. Changes in the physical and chemical characteristics of the ocean due to climate change and ocean acidification will undoubtedly impact the microbial iron cycle. A better understanding of the contemporary role of microbes in the iron cycle will help in predicting how these changes could ultimately influence marine primary productivity.

  8. The Irony of Iron - Biogenic Iron Oxides as an Iron Source to the Ocean.

    PubMed

    Emerson, David

    2015-01-01

    Primary productivity in at least a third of the sunlit open ocean is thought to be iron-limited. Primary sources of dissolved iron (dFe) to the ocean are hydrothermal venting, flux from the sediments along continental margins, and airborne dust. This article provides a general review of sources of hydrothermal and sedimentary iron to the ocean, and speculates upon the role that iron-cycling microbes play in controlling iron dynamics from these sources. Special attention is paid to iron-oxidizing bacteria (FeOB) that live by oxidizing iron and producing biogenic iron oxides as waste products. The presence and ubiquity of FeOB both at hydrothermal systems and in sediments is only beginning to be appreciated. The biogenic oxides they produce have unique properties that could contribute significantly to the dynamics of dFe in the ocean. Changes in the physical and chemical characteristics of the ocean due to climate change and ocean acidification will undoubtedly impact the microbial iron cycle. A better understanding of the contemporary role of microbes in the iron cycle will help in predicting how these changes could ultimately influence marine primary productivity. PMID:26779157

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

    PubMed

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

    2014-09-15

    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. 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.

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

    PubMed

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

    2014-01-01

    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. 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

  11. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbonyl iron. (1) Reduced iron is prepared by reacting ground ferric oxide with hydrogen or carbon... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No....

  12. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbonyl iron. (1) Reduced iron is prepared by reacting ground ferric oxide with hydrogen or carbon... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No....

  13. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... iron is prepared by reacting ground ferric oxide with hydrogen or carbon monoxide at an elevated... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron...

  14. Replacing London's cast iron mains

    SciTech Connect

    Thorne, A. ); Mathews, P. )

    1992-07-01

    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 relatively low beam strength. This can lead, under some circumstances, to failure without external warning, with typically a full-circumferential failure. In congested areas this can lead to serious consequences. As a result, cast iron replacement programs are a common feature in such urban gas distribution systems.

  15. Iron Deficiency Anemia in Pregnancy.

    PubMed

    Breymann, Christian

    2015-10-01

    Anemia is a common problem in obstetrics and perinatal care. Any hemoglobin below 10.5 g/dL can be regarded as true anemia regardless of gestational age. Reasons for anemia in pregnancy are mainly nutritional deficiencies, parasitic and bacterial diseases, and inborn red blood cell disorders such as thalassemias. The main cause of anemia in obstetrics is iron deficiency, which has a worldwide prevalence between estimated 20%-80% and consists of a primarily female population. Stages of iron deficiency are depletion of iron stores, iron-deficient erythropoiesis without anemia, and iron deficiency anemia, the most pronounced form of iron deficiency. Pregnancy anemia can be aggravated by various conditions such as uterine or placental bleedings, gastrointestinal bleedings, and peripartum blood loss. In addition to the general consequences of anemia, there are specific risks during pregnancy for the mother and the fetus such as intrauterine growth retardation, prematurity, feto-placental miss ratio, and higher risk for peripartum blood transfusion. Besides the importance of prophylaxis of iron deficiency, the main therapy options for the treatment of pregnancy anemia are oral iron and intravenous iron preparations.

  16. Calcium, iron and neuronal function.

    PubMed

    Hidalgo, Cecilia; Núñez, Marco T

    2007-01-01

    Calcium and iron play dual roles in neuronal function: they are both essential but when present in excess they cause neuronal damage and may even induce neuronal death. Calcium signals are required for synaptic plasticity, a neuronal process that entails gene expression and which is presumably the cellular counterpart of cognitive brain functions such as learning and memory. Neuronal activity generates cytoplasmic and nuclear calcium signals that in turn stimulate pathways that promote the transcription of genes known to participate in synaptic plasticity. In addition, evidence discussed in this article shows that iron deficiency causes learning and memory impairments that persist following iron repletion, indicating that iron is necessary for normal development of cognitive functions. Recent results from our group indicate that iron is required for long-term potentiation in hippocampal CA1 neurons and that iron stimulates ryanodine receptor-mediated calcium release through ROS produced via the Fenton reaction leading to stimulation of the ERK signaling pathway. These combined results support a coordinated action between iron and calcium in synaptic plasticity and raise the possibility that elevated iron levels may contribute to neuronal degeneration through excessive intracellular calcium increase caused by iron-induced oxidative stress. PMID:17505966

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

    PubMed

    Kosman, Daniel J

    2013-01-01

    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(H(2)O)(6)](3+). Mobilizing this iron requires bio-ferrireduction which in turn requires managing the rapid autoxidation of the resulting Fe(II) 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 Fe(III) and the ROS-generating autoxidation of Fe(II) so as to make this metal ion available as the most ubiquitous prosthetic group in metallobiology. PMID:23264695

  18. Iron oxide surfaces

    NASA Astrophysics Data System (ADS)

    Parkinson, Gareth S.

    2016-03-01

    The current status of knowledge regarding the surfaces of the iron oxides, magnetite (Fe3O4), maghemite (γ-Fe2O3), haematite (α-Fe2O3), and wüstite (Fe1-xO) is reviewed. The paper starts with a summary of applications where iron oxide surfaces play a major role, including corrosion, catalysis, spintronics, magnetic nanoparticles (MNPs), biomedicine, photoelectrochemical water splitting and groundwater remediation. The bulk structure and properties are then briefly presented; each compound is based on a close-packed anion lattice, with a different distribution and oxidation state of the Fe cations in interstitial sites. The bulk defect chemistry is dominated by cation vacancies and interstitials (not oxygen vacancies) and this provides the context to understand iron oxide surfaces, which represent the front line in reduction and oxidation processes. Fe diffuses in and out from the bulk in response to the O2 chemical potential, forming sometimes complex intermediate phases at the surface. For example, α-Fe2O3 adopts Fe3O4-like surfaces in reducing conditions, and Fe3O4 adopts Fe1-xO-like structures in further reducing conditions still. It is argued that known bulk defect structures are an excellent starting point in building models for iron oxide surfaces. The atomic-scale structure of the low-index surfaces of iron oxides is the major focus of this review. Fe3O4 is the most studied iron oxide in surface science, primarily because its stability range corresponds nicely to the ultra-high vacuum environment. It is also an electrical conductor, which makes it straightforward to study with the most commonly used surface science methods such as photoemission spectroscopies (XPS, UPS) and scanning tunneling microscopy (STM). The impact of the surfaces on the measurement of bulk properties such as magnetism, the Verwey transition and the (predicted) half-metallicity is discussed. The best understood iron oxide surface at present is probably Fe3O4(100); the structure is

  19. Preventing childhood anemia in India: iron supplementation and beyond.

    PubMed

    Sachdev, H P S; Gera, T

    2013-05-01

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

  20. Effects of iron deficiency on iron binding and internalization into acidic vacuoles in Dunaliella salina.

    PubMed

    Paz, Yakov; Shimoni, Eyal; Weiss, Meira; Pick, Uri

    2007-07-01

    Uptake of iron in the halotolerant alga Dunaliella salina is mediated by a transferrin-like protein (TTf), which binds and internalizes Fe(3+) ions. Recently, we found that iron deficiency induces a large enhancement of iron binding, which is associated with accumulation of three other plasma membrane proteins that associate with TTf. In this study, we characterized the kinetic properties of iron binding and internalization and identified the site of iron internalization. Iron deficiency induces a 4-fold increase in Fe binding, but only 50% enhancement in the rate of iron uptake and also increases the affinity for iron and bicarbonate, a coligand for iron binding. These results indicate that iron deprivation leads to accumulation and modification of iron-binding sites. Iron uptake in iron-sufficient cells is preceded by an apparent time lag, resulting from prebound iron, which can be eliminated by unloading iron-binding sites. Iron is tightly bound to surface-exposed sites and hardly exchanges with medium iron. All bound iron is subsequently internalized. Accumulation of iron inhibits further iron binding and internalization. The vacuolar inhibitor bafilomycin inhibits iron uptake and internalization. Internalized iron was localized by electron microscopy within vacuolar structures that were identified as acidic vacuoles. Iron internalization is accompanied by endocytosis of surface proteins into these acidic vacuoles. A novel kinetic mechanism for iron uptake is proposed, which includes two pools of bound/compartmentalized iron separated by a rate-limiting internalization stage. The major parameter that is modulated by iron deficiency is the iron-binding capacity. We propose that excessive iron binding in iron-deficient cells serves as a temporary reservoir for iron that is subsequently internalized. This mechanism is particularly suitable for organisms that are exposed to large fluctuations in iron availability. PMID:17513481

  1. 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...

  2. Iron and iron-related proteins in asbestosis.

    EPA Science Inventory

    ABSTRACT: We tested the postulate that iron homeostasis is altered among patients diagnosed to have asbestosis. Lung tissue from six individuals diagnosed to have had asbestosis at autopsy was stained for iron, ferritin, divalent metal transporter 1 (DMT1), and ferroportin 1 (FP...

  3. MALLEABLE IRON BULL LADLE, HOLDS IRON AFTER IT IS TAPPED ...

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

    MALLEABLE IRON BULL LADLE, HOLDS IRON AFTER IT IS TAPPED OUT OF THE CUPOLA UNTIL IT NEEDED BY POURERS ON THE CONVEYOR LINES WHO FILL MOBILE LADLES ATTACHED TO OVERHEAD RAIL SYSTEMS AS THE BULL LADLE TIPS. - Stockham Pipe & Fittings Company, Malleable Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  4. Can Iron Lift Your Learning Ability?

    ERIC Educational Resources Information Center

    Schibeci, Renato

    1997-01-01

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

  5. Iron-Deficiency Anemia (For Parents)

    MedlinePlus

    ... Things to Know About Zika & Pregnancy Iron-Deficiency Anemia KidsHealth > For Parents > Iron-Deficiency Anemia Print A ... common nutritional deficiency in children. About Iron-Deficiency Anemia Every red blood cell in the body contains ...

  6. The Iron Metallome in Eukaryotic Organisms

    PubMed Central

    Dlouhy, Adrienne C.; Outten, Caryn E.

    2013-01-01

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

  7. Iron Meteorites and Upwelling in Antarctica

    NASA Astrophysics Data System (ADS)

    Gourlay, B. S.; Behr, E.; Mardon, A.; Behr, E.

    2016-09-01

    In Antarctica, a meteorite stranding zone, stone meteorites are more common than iron. Dr. Evatt's team suggests that the heat conductivity of iron may be opposing the upwelling effects so iron meteorites sink under the ice unlike the stone ones.

  8. Snapshot of iron response in Shewanella oneidensis by gene network reconstruction

    SciTech Connect

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

    2008-10-09

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

  9. Iron oxide surfaces

    NASA Astrophysics Data System (ADS)

    Parkinson, Gareth S.

    2016-03-01

    The current status of knowledge regarding the surfaces of the iron oxides, magnetite (Fe3O4), maghemite (γ-Fe2O3), haematite (α-Fe2O3), and wüstite (Fe1-xO) is reviewed. The paper starts with a summary of applications where iron oxide surfaces play a major role, including corrosion, catalysis, spintronics, magnetic nanoparticles (MNPs), biomedicine, photoelectrochemical water splitting and groundwater remediation. The bulk structure and properties are then briefly presented; each compound is based on a close-packed anion lattice, with a different distribution and oxidation state of the Fe cations in interstitial sites. The bulk defect chemistry is dominated by cation vacancies and interstitials (not oxygen vacancies) and this provides the context to understand iron oxide surfaces, which represent the front line in reduction and oxidation processes. Fe diffuses in and out from the bulk in response to the O2 chemical potential, forming sometimes complex intermediate phases at the surface. For example, α-Fe2O3 adopts Fe3O4-like surfaces in reducing conditions, and Fe3O4 adopts Fe1-xO-like structures in further reducing conditions still. It is argued that known bulk defect structures are an excellent starting point in building models for iron oxide surfaces. The atomic-scale structure of the low-index surfaces of iron oxides is the major focus of this review. Fe3O4 is the most studied iron oxide in surface science, primarily because its stability range corresponds nicely to the ultra-high vacuum environment. It is also an electrical conductor, which makes it straightforward to study with the most commonly used surface science methods such as photoemission spectroscopies (XPS, UPS) and scanning tunneling microscopy (STM). The impact of the surfaces on the measurement of bulk properties such as magnetism, the Verwey transition and the (predicted) half-metallicity is discussed. The best understood iron oxide surface at present is probably Fe3O4(100); the structure is

  10. The case for iron

    SciTech Connect

    Martin, J.H.; Gordon, R.M.; Fitzwater, S.E. )

    1991-12-01

    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 atmospheric dust loads in these regions are among the lowest in the world. The authors summarize experiments performed in three nutrient-rich areas: The Gulf of Alaska, the Ross Sea, and the equatorial Pacific. In general, populations without added Fe doubled at rates 11-40% of the expected maxima at various temperatures. The additions of nanomole quantities of Fe increased these doubling rates by factors of 2-3. In spite of the lack of Fe, tightly coupled phytoplankton/zooplankton communities seem to inhabit these major nutrient-rich areas. Since Fe is required for the synthesis of chlorophyll and nitrate reductase, little chlorophyll is found and NH{sub 3} is the favored N source. Normal rate values of specific productivity indicate that these populations are healthy, but limited by the insufficient Fe supply. When Fe becomes available either artificially in bottle experiments or in the environment as Fe-rich land masses are approached, diatoms quickly bloom, chlorophyll levels increase, and nutrient stocks are rapidly depleted. These combined results indicate that Fe availability is the primary factor controlling phytoplankton production in nutrient-rich areas of the open sea.

  11. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron oxides. 186.1374 Section 186.1374 Food and... Substances Affirmed as GRAS § 186.1374 Iron oxides. (a) Iron oxides (oxides of iron, CAS Reg. No. 1332-37-2) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron...

  12. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron oxides. 186.1374 Section 186.1374 Food and... Substances Affirmed as GRAS § 186.1374 Iron oxides. (a) Iron oxides (oxides of iron, CAS Reg. No. 1332-37-2) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron...

  13. The role of heme and iron-sulfur clusters in mitochondrial biogenesis, maintenance, and decay with age.

    PubMed

    Atamna, Hani; Walter, Patrick B; Ames, Bruce N

    2002-01-15

    Mitochondria decay with age from oxidative damage and loss of protective mechanisms. Resistance, repair, and replacement mechanisms are essential for mitochondrial preservation and maintenance. Iron plays an essential role in the maintenance of mitochondria, through its two major functional forms: heme and iron-sulfur clusters. Both iron-based cofactors are formed and utilized in the mitochondria and then distributed throughout the cell. This is an important function of mitochondria that is not directly related to the production of ATP. Heme and iron-sulfur clusters are important for the normal assembly and for the optimal activity of the electron transfer complexes. Loss of mitochondrial cytochrome c oxidase (complex IV), integrity of mtDNA, and function can result from abnormal homeostasis of iron. We review the physiological role of iron-sulfur clusters and heme in the integrity of the mitochondria and the generation of oxidants.

  14. Proteasome-mediated turnover of the transcriptional activator FIT is required for plant iron-deficiency responses.

    PubMed

    Sivitz, Alicia; Grinvalds, Claudia; Barberon, Marie; Curie, Catherine; Vert, Grégory

    2011-06-01

    Plants display a number of responses to low iron availability in order to increase iron uptake from the soil. In the model plant Arabidopsis thaliana, the ferric-chelate reductase FRO2 and the ferrous iron transporter IRT1 control iron entry from the soil into the root epidermis. To maintain iron homeostasis, the expression of FRO2 and IRT1 is tightly controlled by iron deficiency at the transcriptional level. The basic helix-loop-helix (bHLH) transcription factor FIT represents the most upstream actor known in the iron-deficiency signaling pathway, and directly regulates the expression of the root iron uptake machinery genes FRO2 and IRT1. However, how FIT is controlled by iron and acts to activate transcription of its targets remains obscure. Here we show that FIT mRNA and endogenous FIT protein accumulate in Arabidopsis roots upon iron deficiency. However, using plants constitutively expressing FIT, we observed that FIT protein accumulation is reduced in iron-limited conditions. This post-transcriptional regulation of FIT is perfectly synchronized with the accumulation of endogenous FIT and IRT1 proteins, and therefore is part of the early responses to low iron. We demonstrated that such regulation affects FIT protein stability under iron deficiency as a result of 26S proteasome-dependent degradation. In addition, we showed that FIT post-translational regulation by iron is required for FRO2 and IRT1 gene expression. Taken together our results indicate that FIT transcriptional and post-translational regulations are integrated in plant roots to ensure that the positive regulator FIT accumulates as a short-lived protein following iron shortage, and to allow proper iron-deficiency responses.

  15. 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...

  16. Iron biofortification of maize grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. 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...

  18. Iron deficiency in the tropics.

    PubMed

    Fleming, A F

    1982-06-01

    Iron in food is classified as belonging to the haem pool, the nonhaem pool, and extraneous sources. Haem iron is derived from vegetable and animal sources with varying bioavailability. Hookworm infestation of the intestinal tract affects 450 million people in the tropics. Schistosoma mansoni caused blood loss in 7 Egyptian patients of 7.5- 25.9 ml/day which is equivalent to a daily loss of iron of .6-7.3 mg daily urinary loss of iron in 9 Egyptian patients. Trichuris trichiura infestation by whipworm is widespread in children with blood loss of 5 ml/day/worm. The etiology of anemia in children besides iron deficiency includes malaria, bacterial or viral infections, folate deficiency and sickle-cell disease. Severe infections cause profound iron-deficiency anemia in children in central American and Malaysia. Plasmodium falciparum malaria-induced anaemia in tropical Africa lowers the mean haemoglobin concentration in the population by 2 g/dI, causing profound anaemia in some. The increased risk of premature delivery, low birthweight, fetal abnormalities, and fetal death is directly related to the degree of maternal anemia. Perinatal mortality was reduced from 38 to 4% in treated anemic mothers. Mental performance was significantly lower in anemic school children and improved after they received iron. Supplements of iron, soy-protein, calcium, and vitamins given to villagers with widespread malnutrition, iron deficiency, and hookworm infestation in Colombia reduced enteric infections in children. Severe iron-deficiency anemia was treated in adults in northern Nigeria by daily in Ferastral 10 ml, which is equivalent to 500 mg of iron per day. Choloroquine, folic acid, rephenium hydroxynaphthoate, and tetrachlorethylene treat adults with severe iron deficiency from hookworm infestation in rural tropical Africa. Blood transfusion is indicated if the patient is dying of anaemia or is pregnant with a haemoglobin concentration 6 gm/dl. In South East Asia, mg per day

  19. Iron deficiency in the tropics.

    PubMed

    Fleming, A F

    1982-06-01

    Iron in food is classified as belonging to the haem pool, the nonhaem pool, and extraneous sources. Haem iron is derived from vegetable and animal sources with varying bioavailability. Hookworm infestation of the intestinal tract affects 450 million people in the tropics. Schistosoma mansoni caused blood loss in 7 Egyptian patients of 7.5- 25.9 ml/day which is equivalent to a daily loss of iron of .6-7.3 mg daily urinary loss of iron in 9 Egyptian patients. Trichuris trichiura infestation by whipworm is widespread in children with blood loss of 5 ml/day/worm. The etiology of anemia in children besides iron deficiency includes malaria, bacterial or viral infections, folate deficiency and sickle-cell disease. Severe infections cause profound iron-deficiency anemia in children in central American and Malaysia. Plasmodium falciparum malaria-induced anaemia in tropical Africa lowers the mean haemoglobin concentration in the population by 2 g/dI, causing profound anaemia in some. The increased risk of premature delivery, low birthweight, fetal abnormalities, and fetal death is directly related to the degree of maternal anemia. Perinatal mortality was reduced from 38 to 4% in treated anemic mothers. Mental performance was significantly lower in anemic school children and improved after they received iron. Supplements of iron, soy-protein, calcium, and vitamins given to villagers with widespread malnutrition, iron deficiency, and hookworm infestation in Colombia reduced enteric infections in children. Severe iron-deficiency anemia was treated in adults in northern Nigeria by daily in Ferastral 10 ml, which is equivalent to 500 mg of iron per day. Choloroquine, folic acid, rephenium hydroxynaphthoate, and tetrachlorethylene treat adults with severe iron deficiency from hookworm infestation in rural tropical Africa. Blood transfusion is indicated if the patient is dying of anaemia or is pregnant with a haemoglobin concentration 6 gm/dl. In South East Asia, mg per day

  20. The Pharmacokinetics and Pharmacodynamics of Iron Preparations

    PubMed Central

    Geisser, Peter; Burckhardt, Susanna

    2011-01-01

    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

  1. Aluminium toxicity and iron homeostasis.

    PubMed

    Ward, R J; Zhang, Y; Crichton, R R

    2001-11-01

    In an animal model of aluminum overload, (aluminium gluconate), the increases in tissue aluminium content were paralleled by elevations of tissue iron in the kidney, liver heart and spleen as well as in various brain regions, frontal, temporal and parietal cortex and hippocampus. Despite such increases in iron content there were no significant changes in the activities of a wide range of cytoprotective enzymes apart from an increase in superoxide dismutase in the frontal cortex of the aluminium loaded rats. Such increases in tissue iron content may be attributed to the stabilisation of IRP-2 by aluminium thereby promoting transferrin receptor synthesis while blocking ferritin synthesis. Using the radioactive tracer (26)Al less than 1% of the injected dose was recovered in isolated ferritin, supporting previous studies which also found little evidence for aluminium storage within ferritin. The increases in brain iron may well be contributory to neurodegeneration, although the pathogenesis by which iron exerts such an effect is unclear.

  2. Microbial acquisition of iron from ferric iron bearing minerals

    SciTech Connect

    Hersman, L.E.; Sposito, G.

    1998-12-31

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

  3. Iron endowment at birth: maternal iron status and other influences.

    PubMed

    Viteri, Fernando E

    2011-11-01

    The iron endowment at birth depends, in large part, on the newborn's birth weight and gestational age. These are determined by many factors, some of which are maternal characteristics, including the following: maternal iron stores at her own birth and during her own early life, maternal growth and development, maternal age at conception, intergenesic intervals, maternal body characteristics and iron status at conception and during early pregnancy, gestational body weight gain, and iron status throughout gestation, particularly at conception and early pregnancy, and gestational body weight gain. Although less studied, paternal influences on the initiation and progression of pregnancy and on maternal environmental exposures are also important. Even though tools for the quantitative evaluation of women's iron status are very well developed, the quantitative estimation of body iron in the newborn and young infant remains a challenge. This article describes the crucial role played by the placenta in protecting the embryo and the fetus. In addition, neonatal health, particularly early in pregnancy, is briefly addressed, as are some important aspects of antenatal nutritional interventions that include iron.

  4. Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

    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). All detected minerals consisted mainly of amorphous iron phosphates, but based on their morphology and localization, three types of precipitates could be discriminated: (1) mineralized filaments at distance from the cells, (2) globules of 100 ± 25 nm in diameter, at the cell surface and (3) a 40-nm thick mineralized layer within the periplasm. All of those phases were shown to be intimately associated with organic molecules. Periplasmic encrustation was accompanied by an accumulation of protein moieties. In the same way, exopolysaccharides were associated with the extracellular mineralized filaments. The evolution of cell encrustation was followed by TEM over the time course of a culture: cell encrustation proceeded progressively, with rapid precipitation in the periplasm (in a few tens of minutes), followed by the formation of surface-bound globules. Moreover, we frequently observed an asymmetric mineral thickening at the cell poles. In parallel, the evolution of iron oxidation was quantified by STXM: iron both contained in the bacteria and in the extracellular precipitates reached complete oxidation within 6 days. While a progressive oxidation of Fe in the bacteria and in the medium could be observed, spatial redox (oxido-reduction state) heterogeneities were detected at the cell poles and in the extracellular precipitates after 1 day. All these findings provide new information to further the understanding of molecular processes involved in iron biomineralization by anaerobic iron-oxidizing bacteria and

  5. Southern Ocean Iron Experiment (SOFex)

    SciTech Connect

    Coale, Kenneth H.

    2005-07-28

    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

  6. Molecular Dynamics Simulation of Iron — A Review

    NASA Astrophysics Data System (ADS)

    Chui, C. P.; Liu, Wenqing; Xu, Yongbing; Zhou, Yan

    2015-12-01

    Molecular dynamics (MD) is a technique of atomistic simulation which has facilitated scientific discovery of interactions among particles since its advent in the late 1950s. Its merit lies in incorporating statistical mechanics to allow for examination of varying atomic configurations at finite temperatures. Its contributions to materials science from modeling pure metal properties to designing nanowires is also remarkable. This review paper focuses on the progress of MD in understanding the behavior of iron — in pure metal form, in alloys, and in composite nanomaterials. It also discusses the interatomic potentials and the integration algorithms used for simulating iron in the literature. Furthermore, it reveals the current progress of MD in simulating iron by exhibiting some results in the literature. Finally, the review paper briefly mentions the development of the hardware and software tools for such large-scale computations.

  7. Iron Mountain Electromagnetic Results

    SciTech Connect

    Gail Heath

    2012-07-01

    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.

  8. Iron bromide vapor laser

    NASA Astrophysics Data System (ADS)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  9. Antimony in iron meteorites

    NASA Technical Reports Server (NTRS)

    Willis, J.

    1981-01-01

    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.

  10. Iron interventions for women and children in low-income countries.

    PubMed

    Stoltzfus, Rebecca J

    2011-04-01

    The WHO estimates that 41% of women and 27% of children suffer from anemia due to iron deficiency. The consequences of iron deficiency anemia include suboptimal mental and motor development in young children, increased risk of maternal mortality, and decreased economic productivity of adults. Recent research also provides evidence that maternal iron deficiency in pregnancy increases neonatal morbidity and mortality. This short review briefly highlights how iron interventions might be positioned within 4 global health initiatives: making pregnancy safer, saving newborn lives, infant and young child feeding, and fortification. The importance of iron nutrition is recognized in the context of child nutrition, fortification, and biofortification, and it is likely that meaningful advances will be made through these initiatives in the coming decade. However, iron nutrition is not yet well integrated into the programmatic agendas for reducing morbidity and mortality of pregnant women and neonates. Iron supplementation in pregnancy has been advocated for decades as a means of controlling anemia, but this outcome has not been sufficient to motivate strong programs and policies, and the evidence base is still sparse for high-priority clinical outcomes. To act on the current evidence for maternal and neonatal health will require stronger advocacy within circles that have not traditionally included nutritionists. Successful implementation will require greater attention to antenatal care for pregnancy women and prioritization of iron-promoting actions (including iron supplementation and deworming) within that platform. PMID:21367936

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

    PubMed

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

    2015-01-24

    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.

  12. High temperature oxidation of iron-iron oxide core-shell nanowires composed of iron nanoparticles.

    PubMed

    Krajewski, M; Brzozka, K; Lin, W S; Lin, H M; Tokarczyk, M; Borysiuk, J; Kowalski, G; Wasik, D

    2016-02-01

    This work describes an oxidation process of iron-iron oxide core-shell nanowires at temperatures between 100 °C and 800 °C. The studied nanomaterial was synthesized through a simple chemical reduction of iron trichloride in an external magnetic field under a constant flow of argon. The electron microscopy investigations allowed determining that the as-prepared nanowires were composed of self-assembled iron nanoparticles which were covered by a 3 nm thick oxide shell and separated from each other by a thin interface layer. Both these layers exhibited an amorphous or highly-disordered character which was traced by means of transmission electron microscopy and Mössbauer spectroscopy. The thermal oxidation was carried out under a constant flow of argon which contained the traces of oxygen. The first stage of process was related to slow transformations of amorphous Fe and amorphous iron oxides into crystalline phases and disappearance of interfaces between iron nanoparticles forming the studied nanomaterial (range: 25-300 °C). After that, the crystalline iron core and iron oxide shell became oxidized and signals for different compositions of iron oxide sheath were observed (range: 300-800 °C) using X-ray diffraction, Raman spectroscopy and Mössbauer spectroscopy. According to the thermal gravimetric analysis, the nanowires heated up to 800 °C under argon atmosphere gained 37% of mass with respect to their initial weight. The structure of the studied nanomaterial oxidized at 800 °C was mainly composed of α-Fe2O3 (∼ 93%). Moreover, iron nanowires treated above 600 °C lost their wire-like shape due to their shrinkage and collapse caused by the void coalescence. PMID:26766540

  13. 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

    Shapiro, A.P.; Sivavec, T.M.; Principe, J.M.

    1997-11-01

    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.

  14. Clinical iron deficiency disturbs normal human responses to hypoxia

    PubMed Central

    Frise, Matthew C.; Cheng, Hung-Yuan; Nickol, Annabel H.; Curtis, M. Kate; Pollard, Karen A.; Roberts, David J.; Ratcliffe, Peter J.; Dorrington, Keith L.; Robbins, Peter A.

    2016-01-01

    BACKGROUND. Iron bioavailability has been identified as a factor that influences cellular hypoxia sensing, putatively via an action on the hypoxia-inducible factor (HIF) pathway. We therefore hypothesized that clinical iron deficiency would disturb integrated human responses to hypoxia. METHODS. We performed a prospective, controlled, observational study of the effects of iron status on hypoxic pulmonary hypertension. Individuals with absolute iron deficiency (ID) and an iron-replete (IR) control group were exposed to two 6-hour periods of isocapnic hypoxia. The second hypoxic exposure was preceded by i.v. infusion of iron. Pulmonary artery systolic pressure (PASP) was serially assessed with Doppler echocardiography. RESULTS. Thirteen ID individuals completed the study and were age- and sex-matched with controls. PASP did not differ by group or study day before each hypoxic exposure. During the first 6-hour hypoxic exposure, the rise in PASP was 6.2 mmHg greater in the ID group (absolute rises 16.1 and 10.7 mmHg, respectively; 95% CI for difference, 2.7–9.7 mmHg, P = 0.001). Intravenous iron attenuated the PASP rise in both groups; however, the effect was greater in ID participants than in controls (absolute reductions 11.1 and 6.8 mmHg, respectively; 95% CI for difference in change, –8.3 to –0.3 mmHg, P = 0.035). Serum erythropoietin responses to hypoxia also differed between groups. CONCLUSION. Clinical iron deficiency disturbs normal responses to hypoxia, as evidenced by exaggerated hypoxic pulmonary hypertension that is reversed by subsequent iron administration. Disturbed hypoxia sensing and signaling provides a mechanism through which iron deficiency may be detrimental to human health. TRIAL REGISTRATION. ClinicalTrials.gov (NCT01847352). FUNDING. M.C. Frise is the recipient of a British Heart Foundation Clinical Research Training Fellowship (FS/14/48/30828). K.L. Dorrington is supported by the Dunhill Medical Trust (R178/1110). D.J. Roberts was

  15. Orally active iron chelators in the treatment of iron overload.

    PubMed

    Olivieri, N F

    1996-03-01

    Data from several trials have provided evidence for the efficacy of deferiprone in the treatment of iron overload in thalassemia major. Deferiprone has now been shown to induce sustained decreases in tissue iron to concentrations that are associated with survival free of the complications of iron overload in deferoxamine-treated patients. Despite this evidence of efficacy, the risk of agranulocytosis mandates a careful evaluation of the risk of this drug in patients willing and able to use deferoxamine. The incidence of agranulocytosis associated with deferiprone is under study in a prospective multicenter trial in Canada, Italy, and the United States, under corporate sponsorship by Apotex Research in Canada. The results of this study should determine the risk associated with the use of this agent and may provide the data required for a US Food and Drug Administration decision regarding licensing of this agent for the treatment of iron overload, a goal supported by investigators worldwide.

  16. Recovery of scrap iron metal value using biogenerated ferric iron.

    PubMed

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

    2006-04-20

    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.

  17. Iron Metabolism in Hodgkin's Disease

    PubMed Central

    Beamish, M. R.; Jones, P. Ashley; Trevett, D.; Evans, I. Howell; Jacobs, A.

    1972-01-01

    An evaluation of iron metabolism has been carried out in 23 untreated patients with Hodgkin's disease and 6 patients with other lymphomata. The reduction in red cell life span is related to the stage of the disease. There is an almost universal impairment of iron release from the reticuloendothelial system with a consequent sideropenia and failure of iron delivery to the bone marrow for erythropoiesis. This defect is found in all stages of the disease and is not related to systemic symptoms. PMID:4567182

  18. [Phosphate metabolism and iron deficiency].

    PubMed

    Yokoyama, Keitaro

    2016-02-01

    Autosomal dominant hypophosphatemic rickets(ADHR)is caused by gain-of-function mutations in FGF23 that prevent its proteolytic cleavage. Fibroblast growth factor 23(FGF23)is a hormone that inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D biosynthesis. Low iron status plays a role in the pathophysiology of ADHR. Iron deficiency is an environmental trigger that stimulates FGF23 expression and hypophosphatemia in ADHR. It was reported that FGF23 elevation in patients with CKD, who are often iron deficient. In patients with nondialysis-dependent CKD, treatment with ferric citrate hydrate resulted in significant reductions in serum phosphate and FGF23.

  19. Austempered ductile iron process development

    NASA Astrophysics Data System (ADS)

    Gupta, C. D.; Keough, J. R.; Pramstaller, D. M.

    1986-11-01

    Pressure from imports and material substitution has severly affected demand for domestic iron industry products. It is estimated that the potential market for Austempered Ductile Iron (ADI) is as large as the market for carburized and/or through hardened forgings. The primary interest in ADI is generated by the economics of process. Improved machinability and reduced processing costs as well as interesting physical properties has created an enormous interest in all metalworking industries towards ADI. The development of gas-fired austempering processes and resoluton of technical and economic uncertainities concerning the process will help improve the outlook for iron founderies.

  20. Targeted iron oxide nanoparticles for the enhancement of radiation therapy.

    PubMed

    Hauser, Anastasia K; Mitov, Mihail I; Daley, Emily F; McGarry, Ronald C; Anderson, Kimberly W; Hilt, J Zach

    2016-10-01

    To increase the efficacy of radiation, iron oxide nanoparticles can be utilized for their ability to produce reactive oxygen species (ROS). Radiation therapy promotes leakage of electrons from the electron transport chain and leads to an increase in mitochondrial production of the superoxide anion which is converted to hydrogen peroxide by superoxide dismutase. Iron oxide nanoparticles can then catalyze the reaction from hydrogen peroxide to the highly reactive hydroxyl radical. Therefore, the overall aim of this project was to utilize iron oxide nanoparticles conjugated to a cell penetrating peptide, TAT, to escape lysosomal encapsulation after internalization by cancer cells and catalyze hydroxyl radical formation. It was determined that TAT functionalized iron oxide nanoparticles and uncoated iron oxide nanoparticles resulted in permeabilization of the lysosomal membranes. Additionally, mitochondrial integrity was compromised when A549 cells were treated with both TAT-functionalized nanoparticles and radiation. Pre-treatment with TAT-functionalized nanoparticles also significantly increased the ROS generation associated with radiation. A long term viability study showed that TAT-functionalized nanoparticles combined with radiation resulted in a synergistic combination treatment. This is likely due to the TAT-functionalized nanoparticles sensitizing the cells to subsequent radiation therapy, because the nanoparticles alone did not result in significant toxicities. PMID:27521615

  1. Observation of Iron Specific Interaction with a Charge Neutral Phospholipid

    NASA Astrophysics Data System (ADS)

    Wang, Wenjie; Zhang, Honghu; Feng, Shuren; San Emeterio, Josue; Kuzmenko, Ivan; Nilsen-Hamilton, Marit; Mallapragada, Surya; Vaknin, David

    2015-03-01

    Using surface sensitive X-ray scattering and spectroscopic techniques we show that phosphatidyl choline (PC) head groups attract positively charged iron ions and complexes even at pH values that are lower than 3. DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) is a zwitterionic lipid typically used as a model system for cell membranes. Within a large pH range (3 -11), it carries a negative charge on the phosphate group and a positive charge on the quaternary ammonium cation, thus appears charge neutral. Further lowering the pH, i.e. adding a proton to the phosphate group, results in a positively charged headgroup. Surprisingly, we detect significant enrichment of iron at the interface of the DPPC monolayer and the aqueous subphase with the pH maintained at 3 or even lower. With a supposedly charge neutral or even positive surface, the observation of surface bound, charge positive iron ions or iron hydroxides is counter-intuitive and suggests iron-specific interaction with the phospholipid headgroup, which is not governed by electrostatic interaction. The effect of the integration of Mms6, a membrane protein that promotes the formation of magnetic nanocrystals, into the DPPC monolayer will also be discussed. Research supported by the U.S. Department of Energy under Contract No. DE-AC02-07CH11358 and DE-AC02-06CH11357.

  2. 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...

  3. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Iron oxides. 73.2250 Section 73.2250 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity. The color additives iron oxides consist of any one or any combination of synthetically prepared iron oxides, including...

  4. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Iron oxides. 73.2250 Section 73.2250 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity. The color additives iron oxides consist of any one or any combination of synthetically prepared iron oxides, including...

  5. Iron trafficking as an antimicrobial target

    PubMed Central

    Frederick, Rosanne E.; Mayfield, Jeffery A.; DuBois, Jennifer L.

    2013-01-01

    Iron is essential for the survival of most organisms. Microbial iron acquisition depends on multiple, sometimes complex steps, many of which are not shared by higher eukaryotes. Depriving pathogenic microbes of iron is therefore a potential antimicrobial strategy. The following minireview briefly describes general elements in microbial iron uptake pathways and summarizes some of the current work aiming at their medicinal inhibition. PMID:19350396

  6. 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...

  7. Method for reducing iron losses in an iron smelting process

    DOEpatents

    Sarma, Balu; Downing, Kenneth B.

    1999-01-01

    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.

  8. Correlation, magnetization and conduction in iron pnictides and iron chalcogenides

    NASA Astrophysics Data System (ADS)

    Yin, Zhiping; Haule, Kristjan; Kotliar, Gabriel

    2011-03-01

    By combining density functional theory (DFT) and dynamical mean field theory (DMFT), we study the electronic properties of iron pnictides and iron chalcogenides in both the paramagnetic and magnetic states. With ab initio derived realistic Coulomb interaction U and Hund's exchange coupling J, we find detailed agreements bewtween our calculations and many experimental observations in these compounds, including ARPES, magnetic properties, optical conductivity and anisotropy, and so on, WITHOUT any adjustment such as shifting of atomic positions, Fermi level and bands and renormalizations of bands which are commonly needed in DFT calculations in order to compare with experiments. Our theory explains the origin of the different magnetizations in FeTe and other iron pnictides and provides a unique physical picture. We find that in the magnetic phase of the iron pnictides, both the spin and the orbital polarization are strongly energy dependent. The spin polarization becomes weaker around Fermi level when the orbital polarization is stronger and vice verse at high energies. We stress on the role of the Hund's J rather than the Coulomb U and show how the iron pnictides and iron chalcogenides differ from other compounds.

  9. Method for reducing iron losses in an iron smelting process

    SciTech Connect

    Sarma, B.; Downing, K.B.

    1999-03-23

    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.

  10. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Service lines: Connections to cast iron or ductile... Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line connected to a cast iron or ductile iron main must be...

  11. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Service lines: Connections to cast iron or ductile... Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line connected to a cast iron or ductile iron main must be...

  12. 21 CFR 310.518 - Drug products containing iron or iron salts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) that contains iron or iron salts for use as an iron source shall bear the following statement: WARNING... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Drug products containing iron or iron salts. 310... SERVICES (CONTINUED) DRUGS FOR HUMAN USE NEW DRUGS Requirements for Specific New Drugs or Devices §...

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

    NASA Astrophysics Data System (ADS)

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

    2006-08-01

    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 μm 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 μm) 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.

  14. IRON-TOLERANT CYANOBACTERIA: IMPLICATIONS FOR ASTROBIOLOGY

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

  15. Iron overload in cultured rat myocardial cells

    NASA Astrophysics Data System (ADS)

    Bauminger, E. R.; Iancu, T. C.; Link, G.; Pinson, A.; Hershko, C.

    1987-03-01

    In order to characterize the nature of iron deposits associated with iron overload in heart cells, Mössbauer spectroscopy and ultrastructural studies were performed in iron loaded heart cell cultures obtained from newborn rats grown in a medium containing 20 μg iron/ml. Maximal uptake of iron after 24 hrs was about 15%. Not more than 20% of the iron in these cells was stored in ferritin and the rest was found in smaller trivalent iron aggregates. With time there was a shift from smaller to larger aggregates. In chase samples there was only a very limited spontaneous release of iron from heart cells. Desferrioxamine, an iron chelating drug, removed a major part of the smaller aggregates, but did not remove ferritin iron.

  16. Iron for restless legs syndrome

    PubMed Central

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

    2014-01-01

    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

  17. Iron catalyzed coal liquefaction process

    DOEpatents

    Garg, Diwakar; Givens, Edwin N.

    1983-01-01

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

  18. Study of iron nanoparticle melting

    NASA Astrophysics Data System (ADS)

    Fedorov, A. V.; Shulgin, A. V.; Lavruk, S. A.

    2016-10-01

    In paper melting process of iron nanoparticles was investigated with molecular dynamics method. Melting temperatures was found for particles with radius from 1.5 to 4 nm. Results match with data of other authors. Heat capacity was calculated based on investigation of caloric curves. Dependence between heat capacity and temperature for different size of nanoparticles was approximated. Heat conductivity of iron nanoparticles was calculated.

  19. Luminescent iron clusters in solution

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  20. Iron loading: a risk factor for osteoporosis.

    PubMed

    Weinberg, E D

    2006-12-01

    Iron loaded persons are at increased risk for infection, neoplasia, arthropathy, cardiomyopathy and an array of endocrine and neurodegenerative diseases. This report summarizes evidence of increased risk of iron loading for osteoporosis. Iron suppresses bone remodeling apparently by decreasing osteoblast formation and new bone synthesis. Low molecular mass iron chelators as well as a natural protein iron chelator, lactoferrin, may be useful in prevention of osteoporosis.

  1. Oxygen isotope relationships in iron meteorites

    NASA Technical Reports Server (NTRS)

    Clayton, R. N.; Mayeda, T. K.; Olsen, E. J.; Prinz, M.

    1983-01-01

    Iron meteorites with oxygen-bearing phases can be classified in terms of their oxygen isotopic abundances. These iron meteorite classes are isotopically similar to various stony meteorite classes, which may indicate a common origin. The group IAB and IIICD irons may be related to the winonaites; group IIE irons may be related to H chondrites; group IVA irons may be related to L or LL chondrites.

  2. Process for the synthesis of iron powder

    DOEpatents

    Welbon, William W.

    1983-01-01

    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.

  3. Process for the synthesis of iron powder

    DOEpatents

    Not Available

    1982-03-06

    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.

  4. Process for the synthesis of iron powder

    DOEpatents

    Welbon, W.W.

    1983-11-08

    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.

  5. Iron transport in Parkinson's disease.

    PubMed

    Hirsch, E C

    2009-12-01

    Dopaminergic cell death in the substantia nigra (SN) is central to Parkinson's disease (PD) but the neurodegenerative mechanisms have not been completely elucidated. Iron accumulation in dopaminergic neurons and glial cells in the SN of PD patients may contribute to the generation of oxidative stress, protein aggregation and neuronal death. However, the mechanisms involved in iron accumulation remain unclear. In previous studies we excluded a role of transferrin and its receptor in iron accumulation while we showed that lactoferrin receptors were overexpressed in blood vessels and dopaminergic neurons in Parkinson's disease. We recently also described an increase in the expression of the divalent metal transporter 1 (DMT1/Nramp2/Slc11a2) in the SN of PD patients. Using the PD animal model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication in mice, we showed that DMT1 expression increased in the ventral mesencephalon of intoxicated animals, concomitant with iron accumulation, oxidative stress and dopaminergic cell loss. A mutation in DMT1 that impairs iron transport protected rodents against parkinsonism-inducing neurotoxins MPTP and 6-hydroxydopamine (6-OHDA). This study supports a critical role for DMT1 in iron-mediated neurodegeneration in PD. PMID:20082992

  6. Management of Iron Deficiency Anemia

    PubMed Central

    Jimenez, Kristine; Kulnigg-Dabsch, Stefanie

    2015-01-01

    Anemia affects one-fourth of the world’s population, and iron deficiency is the predominant cause. Anemia is associated with chronic fatigue, impaired cognitive function, and diminished well-being. Patients with iron deficiency anemia of unknown etiology are frequently referred to a gastroenterologist because in the majority of cases the condition has a gastrointestinal origin. Proper management improves quality of life, alleviates the symptoms of iron deficiency, and reduces the need for blood transfusions. Treatment options include oral and intravenous iron therapy; however, the efficacy of oral iron is limited in certain gastrointestinal conditions, such as inflammatory bowel disease, celiac disease, and autoimmune gastritis. This article provides a critical summary of the diagnosis and treatment of iron deficiency anemia. In addition, it includes a management algorithm that can help the clinician determine which patients are in need of further gastrointestinal evaluation. This facilitates the identification and treatment of the underlying condition and avoids the unnecessary use of invasive methods and their associated risks. PMID:27099596

  7. Relativistic Iron Line Fits

    NASA Astrophysics Data System (ADS)

    Fink, M.; Dauser, T.; Beuchert, T.; Jeffreson, S.; Tawabutr, J.; Wilms, J.; García, J.; Walton, D. J.

    2016-08-01

    The 6.4 keV Iron reflection line possesses strong diagnostic potential for AGN-systems. In the rare case of unobscured AGN, this line receives a contribution from the very center of the accretion flow close to the event horizon that is subject to strong relativistic effects. The shape of this line distortion can be used infer important parameters of the central accretion region, especially the black hole spin parameter a* and the accretion disk inclination i. We analyze several (nine?) bare AGN spectra from the sample of Walton et al. 2012 using high resolution spectra from the XMM and NuStar archives. The relativistic reflection is modeled using the RELXILL code (Dauser 20XX). The newest iteration of the RELXILL model also supports a lamp post geometry for the irradiation of the accretion disk. By combining these detailed models with the wide spectral range of NuStar and XMM/NuStar joint observations we can put tight constraints on the aforementioned parameters and we can constrain the height of the source h in a possible lamp post geometry.

  8. In vitro bioavailability of iron from the heme analogue sodium iron chlorophyllin.

    PubMed

    Miret, Silvia; Tascioglu, Serpil; van der Burg, Monique; Frenken, Leon; Klaffke, Werner

    2010-01-27

    The use of heme analogues from vegetable origin could provide an alternative iron source of potentially high bioavailability. Sodium iron chlorophyllin is a water-soluble semisynthetic chlorophyll derivative where the magnesium in the porphyrin ring has been substituted by iron. We have used an in vitro model that combines gastric and intestinal digestion followed by intestinal iron uptake in Caco-2 cells to determine the bioavailability of iron from sodium iron chlorophyllin. Our results demonstrate that sodium iron chlorophyllin is stable under simulated gastrointestinal conditions and is able to deliver bioavailable iron to Caco-2 cells. Similar to the heme, the bioavailability of iron from sodium iron chlorophyllin is dependent on the food matrix, and it was inhibited by calcium. Potentially, sodium iron chlorophyllin could be used as an iron fortificant from vegetable origin with high bioavailability.

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

    PubMed

    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

    2014-07-25

    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.

  10. Differences in activation of mouse hepcidin by dietary iron and parenterally administered iron dextran: compartmentalization is critical for iron sensing.

    PubMed

    Daba, Alina; Gkouvatsos, Konstantinos; Sebastiani, Giada; Pantopoulos, Kostas

    2013-01-01

    The iron regulatory hormone hepcidin responds to both oral and parenteral iron. Here, we hypothesized that the diverse iron trafficking routes may affect the dynamics and kinetics of the hepcidin activation pathway. To address this, C57BL/6 mice were administered an iron-enriched diet or injected i.p. with iron dextran and analyzed over time. After 1 week of dietary loading with carbonyl iron, mice exhibited significant increases in serum iron and transferrin saturation, as well as in hepatic iron, Smad1/5/8 phosphorylation and bone morphogenetic protein 6 (BMP6), and hepcidin mRNAs. Nevertheless, hepcidin expression reached a plateau afterward, possibly due to upregulation of inhibitory Smad7, Id1, and matriptase-2 mRNAs, while hepatic and splenic iron continued to accumulate over 9 weeks. One day following parenteral administration of iron dextran, mice manifested elevated serum and hepatic iron levels and Smad1/5/8 phosphorylation, but no increases in transferrin saturation or BMP6 mRNA. Surprisingly, hepcidin failed to appropriately respond to acute overload with iron dextran, and a delayed (after 5-7 days) hepcidin upregulation correlated with increased transferrin saturation, partial relocation of iron from macrophages to hepatocytes, and induction of BMP6 mRNA. Our data suggest that the physiological hepcidin response is saturable and are consistent with the idea that hepcidin senses exclusively iron compartmentalized within circulating transferrin and/or hepatocytes.

  11. Neutron scattering of iron-based superconductors

    SciTech Connect

    Shamoto, S; Wakimoto, S; Kodama, K.; Ishikado, Motoyuki; Christianson, Andrew D; Lumsden, Mark D; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Arai, Masatoshi; Kakurai, K.; Esaka, Fumitaka; Iyo, Akira; Kito, Hijiri; Eisaki, Hiroshi

    2011-01-01

    Low-energy spin excitations have been studied on polycrystalline LaFeAsO{sub 1-x}F{sub x} samples by inelastic neutron scattering. The Q-integrated dynamical spin susceptibility {chi}{double_prime}({omega}) of the superconducting samples is found to be comparable to that of the magnetically ordered parent sample. On the other hand, {chi}{double_prime}({omega}) almost vanishes at x = 0.158, where the superconducting transition temperature T{sub c} is suppressed to 7 K. In addition, {chi}{double_prime}({omega}) in optimally doped LaFeAsO{sub 0.918}F{sub 0.082} with T{sub c} = 29 K exhibits a spin resonance mode. The peak energy, E{sub res}, when scaled by k{sub B}T{sub c} is similar to the value of about 4.7 reported in other high-T{sub c} iron-based superconductors. This result suggests that there is intimate relationship between the dynamical spin susceptibility and high-T{sub c} superconductivity in iron-based superconductors, and is consistent with a nesting condition between Fermi surfaces at the {Gamma} and M points.

  12. Iron Necessity: The Secret of Wolbachia's Success?

    PubMed Central

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

    2014-01-01

    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

  13. Iron necessity: the secret of Wolbachia's success?

    PubMed

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

    2014-10-01

    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

  14. 49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cast iron or ductile iron lines. 192.487 Section 192.487 Transportation Other Regulations Relating to... iron or ductile iron lines. (a) General corrosion. Except for cast iron or ductile iron pipe, each... the purpose of this paragraph. (b) Localized corrosion pitting. Except for cast iron or ductile...

  15. 49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... cast iron or ductile iron lines. 192.487 Section 192.487 Transportation Other Regulations Relating to... iron or ductile iron lines. (a) General corrosion. Except for cast iron or ductile iron pipe, each... the purpose of this paragraph. (b) Localized corrosion pitting. Except for cast iron or ductile...

  16. Defect Interaction in Iron and Iron-based Alloys

    NASA Astrophysics Data System (ADS)

    Xu, Haixuan; Stocks, G. Malcolm; Stoller, Roger

    2014-03-01

    Magnetism has a profound influence on the defect properties in iron and iron-based alloys. For instance, it has been shown from first principles calculations that the helium interstitial occupies the tetrahedral site instead of octahedral site in contrast to all previous work that neglected the magnetic effects. In this study, we explore the effects of magnetism on the defect interaction, primarily interstitial-type defects, in bcc iron and Fe-Cr systems. The magnetic moment change during the interaction of two 1/2 <111>interstitial loops in bcc iron was calculated using the ab initio locally self-consistent multiple-scattering (LSMS) method and a significant fluctuation was observed. Adding Cr significantly modifies the magnetic structure of the defects and defect interactions. In addition, the effects of magnetism on the defect energetics are evaluated. This study provides useful insights on whether magnetism can be used as a effective means to manipulate the defect evolution in iron-based structural alloys. This material is based upon work supported as part of the Center for Defect Physics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

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

    PubMed Central

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

    2011-01-01

    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

  18. Aerogravity and remote sensing observations of an iron deposit in Gara Djebilet, southwestern Algeria

    NASA Astrophysics Data System (ADS)

    Bersi, Mohand; Saibi, Hakim; Chabou, Moulley Charaf

    2016-04-01

    The Gara Djebilet iron ore region is one of the most important regions in Africa. Located in the southwestern part of Algeria at the border with Mauritania, the Gara Djebilet region is characterized by steep terrain, which makes this area not easily accessible. Due to these conditions, remote sensing techniques and geophysics are the best ways to map this iron ore. The Gara Djebilet formations are characterized by high iron content that is especially rich in hematite, chamosite and goethite. The high iron content causes an absorption band at 0.88 μm, which is referred to as band 5 in the Operational Land Imager (OLI) Landsat 8 images. In this study, we integrated geological data, aerogravity data, and remote sensing data for the purpose of mapping the distribution of the Gara Djebilet iron deposit. Several remote sensing treatments were applied to the Landsat 8 OLI image, such as color composites, band ratioing, principal component analysis and a mathematical index, which helped locate the surface distribution of the iron ore. The results from gravity gradient interpretation techniques, 2-D forward modeling and 3-D inversion of aerogravity data provided information about the 2-D and 3-D distribution of the iron deposit. The combination of remote sensing and gravity results help us evaluate the ore potential of Gara Djebilet. The estimated tonnage of the iron ore at Gara Djebilet is approximately 2.37 billion tonnes with 57% Fe.

  19. Membrane development in the cyanobacterium, Anacystis nidulans, during recovery from iron starvation

    SciTech Connect

    Pakrasi, H.B.; Goldenberg, A.; Sherman, L.A.

    1985-09-01

    Deprivation of iron from the growth medium results in physiological as well as structural changes in the unicellular cyanobacterium Anacystis nidulans R2. Important among these changes are alterations in the composition and function of the photosynthetic membranes. Room-temperature absorption spectra of iron-starved cyanobacterial cells show a chlorophyll absorption peak at 672 nanometers, 7 nanometers blue-shifted from its normal position at 679 nanometers. Iron-starved cells have decreased amounts of chlorophyll and phycobilins. Their fluorescence spectra (77K) have one prominent chlorophyll emission peak at 684 nanometers as compared to three peaks at 687, 696, and 717 nanometers from normal cells. Chlorophyll-protein analysis of iron-deprived cells indicated the absence of high molecular weight bands. Addition of iron to iron-starved cells induced a restoration process in which new components were initially synthesized and integrated into preexisting membranes; at later times, new membranes were assembled and cell division commenced. Synthesis of chlorophyll and phycocyanins started almost immediately after the addition of iron. The origin of the fluorescence emission at 687 and 696 nanometers is discussed in relation to the specific chlorophyll-protein complexes formed during iron reconstitution. 26 references, 2 figures, 1 table.

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

    PubMed

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

    2007-01-01

    Monodisperse crystalline zero-valent iron, iron-nickel, iron-palladium nanowires were synthesised using template-directed electrodeposition methods. Prior to nanowire fabrication, alumina nanotemplates with controlled pore structure (e.g. pore diameter and porosity) were fabricated by anodising high purity aluminium foil in sulphuric acid. After fabrication of alumina nanotemplates, iron, iron-nickel and iron-palladium nanowires were electrodeposited within the pore structure. The dimensions of nanowires including diameter and length were precisely controlled by pore diameter of anodised alumina and deposition rate and time. The composition, crystal structure and orientation were controlled by adjusting electrodeposition parameters including applied current density and solution compositions.

  1. Synthesis, properties, and applications of iron nanoparticles.

    SciTech Connect

    Huber, Dale L.

    2005-01-01

    Iron, the most ubiquitous of the transition metals and the fourth most plentiful element in the Earths crust, is the structural backbone of our modern infrastructure. It is therefore ironic that as a nanoparticle, iron has been somewhat neglected in favor of its own oxides, as well as other metals such as cobalt, nickel, gold, and platinum. This is unfortunate, but understandable. Irons reactivity is important in macroscopic applications (particularly rusting), but is a dominant concern at the nanoscale. Finely divided iron has long been known to be pyrophoric, which is a major reason that iron nanoparticles have not been more fully studied to date. This extreme reactivity has traditionally made iron nanoparticles difficult to study and inconvenient for practical applications. Iron however has a great deal to offer at the nanoscale, including very potent magnetic and catalytic properties. Recent work has begun to take advantage of irons potential, and work in this field appears to be blossoming.

  2. Sequestration and Scavenging of Iron in Infection

    PubMed Central

    Parrow, Nermi L.; Fleming, Robert E.

    2013-01-01

    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

  3. Shigella Iron Acquisition Systems and their Regulation

    PubMed Central

    Wei, Yahan; Murphy, Erin R.

    2016-01-01

    Survival of Shigella within the host is strictly dependent on the ability of the pathogen to acquire essential nutrients, such as iron. As an innate immune defense against invading pathogens, the level of bio-available iron within the human host is maintained at exceeding low levels, by sequestration of the element within heme and other host iron-binding compounds. In response to sequestration mediated iron limitation, Shigella produce multiple iron-uptake systems that each function to facilitate the utilization of a specific host-associated source of nutrient iron. As a mechanism to balance the essential need for iron and the toxicity of the element when in excess, the production of bacterial iron acquisition systems is tightly regulated by a variety of molecular mechanisms. This review summarizes the current state of knowledge on the iron-uptake systems produced by Shigella species, their distribution within the genus, and the molecular mechanisms that regulate their production. PMID:26904516

  4. FOLLOW-UP OF A RANDOMIZED CONTROLLED TRIAL OF IRON-FORTIFIED (12.7 MG/L) VS. LOW-IRON (2.3 MG/L) INFANT FORMULA: DEVELOPMENTAL OUTCOME AT 10 YEARS

    PubMed Central

    Lozoff, Betsy; Castillo, Marcela; Clark, Katy M.; Smith, Julia B.

    2012-01-01

    Objective To assess long-term developmental outcome in children who received iron-fortified or low-iron formula. Design Follow-up at 10 years of randomized controlled trial (1991–1994) of 2 levels of formula iron. Examiners blind to group. Setting Urban areas around Santiago, Chile. Participants Original study enrolled healthy full-term infants in community clinics; 835 completed the trial. At 10 years, 573 were assessed (57%). Intervention Iron-fortified (12.7 mg/l) or low-iron (2.3 mg/l) formula from 6 to 12 months. Main Outcome Measures IQ, spatial memory, arithmetic achievement, visual-motor integration, visual perception, and motor functioning. We used covaried regression to compare iron-fortified and low-iron groups and consider hemogobin (HB) prior to randomization and sensitivity analyses to identify 6-month HB at which groups diverged in outcome. Results Compared to low-iron, the iron-fortified group scored lower on every 10-year outcome (significant for spatial memory, visual-motor integration; suggestive for IQ, arithmetic, visual perception, motor coordination; 1.4 – 4.6 points lower, effect sizes 0.13 – 0.21). Children with high 6-month HB (> 128 g/l) showed poorer outcome on these measures if they received iron-fortified formula (10.7 – 19.3 points lower; large effect sizes, 0.85 – 1.36); those with low HB (< 105 g/l) showed better outcome (2.6 – 4.5 points higher; small but significant effects, 0.22 – 0.36). High HB represented 5.5% of sample (n = 26); low HB, 17.0% (n = 87). Conclusions Long-term development may be adversely affected in infants with high HB who receive 12.7 mg/l iron-fortified formula. Optimal amounts of iron in infant formula warrant further study. PMID:22064877

  5. Preparation and protection of iron and iron compounds

    NASA Astrophysics Data System (ADS)

    Koprinarov, N.; Konstantinova, M.; Avdeev, G.; Ruskov, T.; Tzacheva, Tz

    2012-03-01

    Iron, iron carbide and iron oxide nano- and micro-particles were synthesized in a hermetically sealed container using ferrocene and a mixture of ferrocene, xylene and water. The particles produced possess well expressed magnetic properties and are wrapped in a protective carbon cover. Carbon provides excellent protection against moisture and chemical influences and insures a long-lasting stability. Structural changes in the particles and their covers were examined at up to 1000 °C in vacuum and 800 °C in air, as were their stability under the influence of acids. The particles morphology was examined by scanning (SEM) and transmission electron microscopy (TEM); their chemical composition and crystal structure were studied by X-ray diffraction (XRD), Mössbauer spectroscopy and electron probe X-ray micro analysis and energy dispersive X-ray spectrometry (EDS).

  6. Iron isotope composition of some Archean and Proterozoic iron formations

    NASA Astrophysics Data System (ADS)

    Planavsky, Noah; Rouxel, Olivier J.; Bekker, Andrey; Hofmann, Axel; Little, Crispin T. S.; Lyons, Timothy W.

    2012-03-01

    Fe isotopes can provide new insight into redox-dependent biogeochemical processes. Precambrian iron formations (IF) are deserving targets for Fe isotope studies because they are composed predominantly of authigenic Fe phases and record a period of unprecedented iron deposition in Earth's history. We present Fe isotope data for bulk samples from 24 Archean and Proterozoic IF and eight Phanerozoic Fe oxide-rich deposits. These data reveal that many Archean and early Paleoproterozoic iron formations were a sink for isotopically heavy Fe, in contrast to later Proterozoic and Phanerozoic Fe oxide-rich rocks. The positive δ56Fe values in IF are best explained by delivery of particulate ferric oxides formed in the water column to the sediment-water interface. Because IF are a net sink for isotopically heavy Fe, there must be a corresponding pool of isotopically light Fe in the sedimentary record. Earlier work suggested that Archean pyritic black shales were an important part of this light sink before 2.35 billion years ago (Ga). It is therefore likely that the persistently and anomalously low δ56Fe values in shales are linked with the deposition of isotopically heavy Fe in IF in the deeper parts of basins. IF deposition produced a residual isotopically light dissolved Fe pool that was captured by pyritic Fe in shales. Local dissimilatory Fe reduction in porewater and associated diagenetic reactions resulting in pyrite and carbonate precipitation may have further enhanced Fe isotope heterogeneity in marine sediments, and an 'iron shuttle' may have transported isotopically light Fe from shelf sediments to the basin. Nevertheless, water-column processing of hydrothermally delivered Fe likely had the strongest influence on the bulk iron isotope composition of Archean and Paleoproterozoic iron formations and other marine sediments.

  7. Haem iron-containing peroxidases.

    PubMed

    Isaac, I S; Dawson, J H

    1999-01-01

    Peroxidases are enzymes that utilize hydrogen peroxide to oxidize substrates. A histidine residue on the proximal side of the haem iron ligates most peroxidases. The various oxidation states and ligand complexes have been spectroscopically characterized. HRP-I is two oxidation states above ferric HRP. It contains an oxoferryl (= oxyferryl) iron with a pi-radical cation that resides on the haem. HRP-II is one oxidation state above ferric HRP and contains an oxoferryl iron. HRP-III is equivalent to the oxyferrous state. Only compounds I and II are part of the peroxidase reaction cycle. CCP-ES contains an oxoferryl iron but the radical cation resides on the Trp-191 residue and not on the haem. CPO is the only known peroxidase that is ligated by a cysteine residue rather than a histidine residue, on the proximal side of the haem iron. CPO is a more versatile enzyme, catalysing numerous types of reaction: peroxidase, catalase and halogenation reactions. The various CPO species are less stable than other peroxidase species and more elusive, thus needing further characterization. The roles of the amino acid residues on the proximal and distal sides of the haem need more investigation to further decipher their specific roles. Haem proteins, especially peroxidases, are structure-function-specific. PMID:10730188

  8. Sonochemical synthesis of iron colloids

    SciTech Connect

    Suslick, K.S.; Fang, M.; Hyeon, T.

    1996-11-27

    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.

  9. Graphite Formation in Cast Iron

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.

    1985-01-01

    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.

  10. Redox control of iron regulatory proteins.

    PubMed

    Fillebeen, Carine; Pantopoulos, Kostas

    2002-01-01

    Iron regulatory proteins, IRP1 and IRP2, are cytoplasmic proteins of the iron-sulfur cluster isomerase family and serve as major post-transcriptional regulators of cellular iron metabolism. They bind to 'iron responsive elements' (IREs) of several mRNAs and thereby control their translation or stability. IRP1 and IRP2 respond to alterations in intracellular iron levels, but also to other signals such as nitric oxide (NO) and reactive oxygen species (ROS). The redox regulation of IRP1 and IRP2 provides direct links between the control of iron homeostasis and oxidative stress.

  11. Advances in Pediatric Intravenous Iron Therapy.

    PubMed

    Mantadakis, Elpis

    2016-01-01

    Iron deficiency anemia (IDA) continues to be very common worldwide. Intravenous (IV) iron is an infrequently used therapeutic option in children with IDA despite numerous studies in adults and several small but notable pediatric studies showing efficacy and safety. Presently, the availability of newer IV iron products allows for replacement of the total iron deficit at a single setting. These products appear safer compared to the high molecular weight iron dextrans of the past. Herein, we review the medical literature and suggest that front line use of IV iron should be strongly considered in diseases associated with IDA in children.

  12. A Systems Biology Approach to Iron Metabolism

    PubMed Central

    Chifman, J.; Laubenbacher, R.; Torti, S.V.

    2015-01-01

    Iron is critical to the survival of almost all living organisms. However, inappropriately low or high levels of iron are detrimental and contribute to a wide range of diseases. Recent advances in the study of iron metabolism have revealed multiple intricate pathways that are essential to the maintenance of iron homeostasis. Further, iron regulation involves processes at several scales, ranging from the subcellular to the organismal. This complexity makes a systems biology approach crucial, with its enabling technology of computational models based on a mathematical description of regulatory systems. Systems biology may represent a new strategy for understanding imbalances in iron metabolism and their underlying causes. PMID:25480643

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

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

  14. A phosphomimetic mutation at Ser-138 renders iron regulatory protein 1 sensitive to iron-dependent degradation.

    PubMed

    Fillebeen, Carine; Chahine, Danielle; Caltagirone, Annie; Segal, Phillip; Pantopoulos, Kostas

    2003-10-01

    Iron regulatory protein 1 (IRP1) binds to mRNA iron-responsive elements (IREs) and thereby controls the expression of IRE-containing mRNAs. In iron-replete cells, assembly of a cubane [4Fe-4S] cluster inhibits IRE-binding activity and converts IRP1 to a cytosolic aconitase. Earlier experiments with Saccharomyces cerevisiae suggested that phosphomimetic mutations of Ser-138 negatively affect the stability of the cluster (N. M. Brown, S. A. Anderson, D. W. Steffen, T. B. Carpenter, M. C. Kennedy, W. E. Walden, and R. S. Eisenstein, Proc. Natl. Acad. Sci. USA 95:15235-15240, 1998). Along these lines, we show here that a highly purified preparation of recombinant human IRP1 bearing a phosphomimetic S138E substitution (IRP1(S138E)) lacks aconitase activity, which is a hallmark of [4Fe-4S] cluster integrity. Similarly, IRP1(S138E) expressed in mammalian cells fails to function as aconitase. Furthermore, we demonstrate that the impairment of [4Fe-4S] cluster assembly in mammalian cells sensitizes IRP1(S138E) to iron-dependent degradation. This effect can be completely blocked by the iron chelator desferrioxamine or by the proteasome inhibitors MG132 and lactacystin. As expected, the stability of wild-type or phosphorylation-deficient IRP1(S138A) is not affected by iron manipulations. Ser-138 and flanking sequences appear to be highly conserved in the IRP1s of vertebrates, whereas insect IRP1 orthologues and nonvertebrate IRP1-like molecules contain an S138A substitution. Our data suggest that phosphorylation of Ser-138 may provide a basis for an additional mechanism for the control of vertebrate IRP1 activity at the level of protein stability.

  15. Non-heme iron as ferrous sulfate does not interact with heme iron absorption in humans.

    PubMed

    Gaitán, Diego; Olivares, Manuel; Lönnerdal, Bo; Brito, Alex; Pizarro, Fernando

    2012-12-01

    The absorption of heme iron has been described as distinctly different from that of non-heme iron. Moreover, whether heme and non-heme iron compete for absorption has not been well established. Our objective was to investigate the potential competition between heme and non-heme iron as ferrous sulfate for absorption, when both iron forms are ingested on an empty stomach. Twenty-six healthy nonpregnant women were selected to participate in two iron absorption studies using iron radioactive tracers. We obtained the dose-response curve for absorption of 0.5, 10, 20, and 50 mg heme iron doses, as concentrated red blood cells. Then, we evaluated the absorption of the same doses, but additionally we added non-heme iron, as ferrous sulfate, at constant heme/non-heme iron molar ratio (1:1). Finally, we compare the two curves by a two-way ANOVA. Iron sources were administered on an empty stomach. One factor analysis showed that heme iron absorption was diminished just by increasing total heme iron (P < 0.0001). The addition of non-heme iron as ferrous sulfate did not have any effect on heme iron absorption (P = NS). We reported evidence that heme and non-heme iron as ferrous sulfate does not compete for absorption. The mechanism behind the absorption of these iron sources is not clear. PMID:22935997

  16. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism

    PubMed Central

    Horniblow, Richard D.; Dowle, Miriam; Iqbal, Tariq H.; Latunde-Dada, Gladys O.; Palmer, Richard E.

    2015-01-01

    Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease. PMID:26378798

  17. Measurement of hair iron concentration as a marker of body iron content

    PubMed Central

    SAHIN, CEM; PALA, CIGDEM; KAYNAR, LEYLAGUL; TORUN, YASEMIN ALTUNER; CETIN, AYSUN; KURNAZ, FATIH; SIVGIN, SERDAR; SAHIN, FATIH SERDAR

    2015-01-01

    The aim of the present study was to define the possible association between blood parameters and hair iron concentration in patient groups showing a difference in body iron content. The study population comprised subjects with iron deficiency anaemia and transfusion-related anaemia with different body iron contents and a healthy control group. All the cases included in the study were examined with respect to hair iron concentration, serum iron, total iron-binding capacity (TIBC), transferrin saturation and erythrocyte markers in the total blood count with ferritin values. Differences in hair iron concentration were evaluated between the groups. Correlation analysis was applied to define the association between the laboratory values used as markers of body iron content and hair iron concentration. A statistically significant difference was determined in hair iron 56Fe and 57Fe concentrations between the group with transfusion-related anaemia, the iron deficiency anaemia group and the healthy control group (P<0.001). In addition, a positive correlation was determined between hair iron 56Fe and 57Fe concentrations and serum iron, ferritin level, transferrin saturation, mean erythrocyte volume and mean erythrocyte haemoglobin values and a negative correlation with TIBC. In conclusion, the results of the present study showed a statistically significant difference in the hair iron concentrations of the patient groups with different body iron content and these values were correlated to the laboratory markers of body iron content. PMID:26137241

  18. Disorders of iron metabolism. Part 1: molecular basis of iron homoeostasis.

    PubMed

    Muñoz, Manuel; García-Erce, José Antonio; Remacha, Angel Francisco

    2011-04-01

    IRON FUNCTIONS: Iron is an essential micronutrient, as it is required for satisfactory erythropoietic function, oxidative metabolism and cellular immune response. IRON PHYSIOLOGY: Absorption of dietary iron (1-2 mg/day) is tightly regulated and just balanced against iron loss because there are no active iron excretory mechanisms. Dietary iron is found in haem (10%) and non-haem (ionic, 90%) forms, and their absorption occurs at the apical surface of duodenal enterocytes via different mechanisms. Iron is exported by ferroportin 1 (the only putative iron exporter) across the basolateral membrane of the enterocyte into the circulation (absorbed iron), where it binds to transferrin and is transported to sites of use and storage. Transferrin-bound iron enters target cells-mainly erythroid cells, but also immune and hepatic cells-via receptor-mediated endocytosis. Senescent erythrocytes are phagocytosed by reticuloendothelial system macrophages, haem is metabolised by haem oxygenase, and the released iron is stored as ferritin. Iron will be later exported from macrophages to transferrin. This internal turnover of iron is essential to meet the requirements of erythropoiesis (20-30 mg/day). As transferrin becomes saturated in iron-overload states, excess iron is transported to the liver, the other main storage organ for iron, carrying the risk of free radical formation and tissue damage. REGULATION OF IRON HOMOEOSTASIS: Hepcidin, synthesised by hepatocytes in response to iron concentrations, inflammation, hypoxia and erythropoiesis, is the main iron-regulatory hormone. It binds ferroportin on enterocytes, macrophages and hepatocytes triggering its internalisation and lysosomal degradation. Inappropriate hepcidin secretion may lead to either iron deficiency or iron overload.

  19. Iron deficiency and iron excess damage mitochondria and mitochondrial DNA in rats.

    PubMed

    Walter, Patrick B; Knutson, Mitchell D; Paler-Martinez, Andres; Lee, Sonia; Xu, Yu; Viteri, Fernando E; Ames, Bruce N

    2002-02-19

    Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (< or =5 microg/day) and iron-normal (800 microg/day) rats and in both groups after daily high-iron supplementation (8,000 microg/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 microg) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 x nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake.

  20. Direct Biohydrometallurgical Extraction of Iron from Ore

    SciTech Connect

    T.C. Eisele

    2005-10-01

    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.

  1. Monitoring iron uptake by siderophores.

    PubMed

    Hoegy, Françoise; Schalk, Isabelle J

    2014-01-01

    Iron is an important element for almost all forms of life. In order to get access to this essential nutriment, Pseudomonads produce two major siderophores, pyoverdine PVD and pyochelin (PCH). Uptake of iron in bacterial cells can be monitored accurately using (55)Fe. Bacteria cells are incubated in the presence of either PVD or PCH loaded with (55)Fe. After incubation, extracellular iron ions are separated from those accumulated in the bacteria cells by either centrifugation or filtration on glass microfiber filters, for the PCH and PVD assays, respectively. (55)Fe contained in the harvested cells on the filter or in the cell pellet is counted in scintillation cocktail. The number of moles of (55)Fe transported can be determined using the specific activity of the radionuclide. PMID:24818918

  2. Facile and sustainable synthesis of shaped iron oxide nanoparticles: effect of iron precursor salts on the shapes of iron oxides.

    PubMed

    Sayed, Farheen N; Polshettiwar, Vivek

    2015-05-05

    A facile and sustainable protocol for synthesis of six different shaped iron oxides is developed. Notably, all the six shapes of iron oxides can be synthesised using exactly same synthetic protocol, by simply changing the precursor iron salts. Several of the synthesised shapes are not reported before. This novel protocol is relatively easy to implement and could contribute to overcome the challenge of obtaining various shaped iron oxides in economical and sustainable manner.

  3. Facile and Sustainable Synthesis of Shaped Iron Oxide Nanoparticles: Effect of Iron Precursor Salts on the Shapes of Iron Oxides

    PubMed Central

    Sayed, Farheen N.; Polshettiwar, Vivek

    2015-01-01

    A facile and sustainable protocol for synthesis of six different shaped iron oxides is developed. Notably, all the six shapes of iron oxides can be synthesised using exactly same synthetic protocol, by simply changing the precursor iron salts. Several of the synthesised shapes are not reported before. This novel protocol is relatively easy to implement and could contribute to overcome the challenge of obtaining various shaped iron oxides in economical and sustainable manner. PMID:25939969

  4. Estimation of dietary iron bioavailability from food iron intake and iron status.

    PubMed

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

    2014-01-01

    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

  5. Iron chelation and multiple sclerosis

    PubMed Central

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

    2014-01-01

    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 1α, 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

  6. Disassembling Iron Availability to Phytoplankton

    PubMed Central

    Shaked, Yeala; Lis, Hagar

    2012-01-01

    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

  7. Selected properties of iron aluminides

    SciTech Connect

    Schneibel, J.H.

    1994-09-01

    Important properties of iron aluminides have been compiled in order to help engineers and scientists to be able to quickly assess this materials system. This compilation is by no means exhaustive, but it represents a reasonable first effort to summarize the properties of iron aluminides. Considerable care has been, used in assembling the data into tables. However, no guarantee can be made that all the values compiled here are correct; and in case of doubt, or in order to obtain more detailed information, the original sources should always be consulted.

  8. Bioavailability of bi- and trivalent oral iron preparations. Investigations of iron absorption by postabsorption serum iron concentrations curves.

    PubMed

    Dietzfelbinger, H

    1987-01-01

    Since 1977 the bioavailability of 14 bi- and trivalent oral iron preparations has been investigated in five separate orientated clinical studies by using postabsorption serum iron concentration curves. The range of relative bioavailability was 46 to 100% in the first group of preparations, 31 to 47% in the second group and 6 to 29% in the third group. The first group contained mainly bivalent quick release preparations, the second group slow or sustained release preparations and the third mainly trivalent iron preparations. The postabsorption serum iron concentration curves which show a good congruence with exact 59Fe whole body retention tests again confirmed the nearly 50-year-old rule that bivalent iron is up to 16 times better absorbed than trivalent iron. There is no doubt that the oral iron preparations of good bioavailability are able to cure an iron deficiency more rapidly than iron preparations with a low bioavailability. This therefore has a clear influence on the overall expense of iron therapy. Only those preparations from the first group can be recommended for oral iron therapy. The preparations in the second group are less suitable and those in the third group should be excluded from iron therapy in all countries. PMID:3566864

  9. Fatal overdose of iron tablets in adults.

    PubMed

    Abhilash, Kundavaram P P; Arul, J Jonathan; Bala, Divya

    2013-09-01

    Acute iron toxicity is usually seen in children with accidental ingestion of iron-containing syrups. However, the literature on acute iron toxicity with suicidal intent in adults is scant. We report, the first instance of two adults with fatal ingestion of a single drug overdose with iron tablets from India. Two young adults developed severe gastro-intestinal bleeding and fulminant hepatic failure 48 h after deliberate consumption of large doses of iron tablets. Serum iron levels measured 36 h after ingestion were normal presumably due to the redistribution of iron to the intracellular compartment. Despite aggressive supportive management in medical intensive care unit of a tertiary care hospital, the patients succumbed to the toxic doses of iron.

  10. Neurodegeneration with brain iron accumulation (NBIA)

    MedlinePlus

    ... gov/ency/article/001225.htm Neurodegeneration with brain iron accumulation (NBIA) To use the sharing features on this page, please enable JavaScript. Neurodegeneration with brain iron accumulation (formerly known as Hallervorden-Spatz disease) is ...

  11. Fatal overdose of iron tablets in adults.

    PubMed

    Abhilash, Kundavaram P P; Arul, J Jonathan; Bala, Divya

    2013-09-01

    Acute iron toxicity is usually seen in children with accidental ingestion of iron-containing syrups. However, the literature on acute iron toxicity with suicidal intent in adults is scant. We report, the first instance of two adults with fatal ingestion of a single drug overdose with iron tablets from India. Two young adults developed severe gastro-intestinal bleeding and fulminant hepatic failure 48 h after deliberate consumption of large doses of iron tablets. Serum iron levels measured 36 h after ingestion were normal presumably due to the redistribution of iron to the intracellular compartment. Despite aggressive supportive management in medical intensive care unit of a tertiary care hospital, the patients succumbed to the toxic doses of iron. PMID:24339645

  12. Synthetic mononuclear nonheme iron-oxygen intermediates.

    PubMed

    Nam, Wonwoo

    2015-08-18

    Mononuclear nonheme iron-oxygen species, such as iron-superoxo, -peroxo, -hydroperoxo, and -oxo, are key intermediates involved in dioxygen activation and oxidation reactions catalyzed by nonheme iron enzymes. Because these iron-oxygen intermediates are short-lived due to their thermal instability and high reactivity, it is challenging to investigate their structural and spectroscopic properties and reactivity in the catalytic cycles of the enzymatic reactions themselves. One way to approach such problems is to synthesize biomimetic iron-oxygen complexes and to tune their geometric and electronic structures for structural characterization and reactivity studies. Indeed, a number of biologically important iron-oxygen species, such as mononuclear nonheme iron(III)-superoxo, iron(III)-peroxo, iron(III)-hydroperoxo, iron(IV)-oxo, and iron(V)-oxo complexes, were synthesized recently, and the first X-ray crystal structures of iron(III)-superoxo, iron(III)-peroxo, and iron(IV)-oxo complexes in nonheme iron models were successfully obtained. Thus, our understanding of iron-oxygen intermediates in biological reactions has been aided greatly from the studies of the structural and spectroscopic properties and the reactivities of the synthetic biomimetic analogues. In this Account, we describe our recent results on the synthesis and characterization of mononuclear nonheme iron-oxygen complexes bearing simple macrocyclic ligands, such as N-tetramethylated cyclam ligand (TMC) and tetraamido macrocyclic ligand (TAML). In the case of iron-superoxo complexes, an iron(III)-superoxo complex, [(TAML)Fe(III)(O2)](2-), is described, including its crystal structure and reactivities in electrophilic and nucleophilic oxidative reactions, and its properties are compared with those of a chromium(III)-superoxo complex, [(TMC)Cr(III)(O2)(Cl)](+), with respect to its reactivities in hydrogen atom transfer (HAT) and oxygen atom transfer (OAT) reactions. In the case of iron-peroxo intermediates

  13. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron (III) oxide (CAS Reg. No. 1309-37-1, red-brown to black trigonal crystals). (b) In accordance with §...

  14. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron (III) oxide (CAS Reg. No. 1309-37-1, red-brown to black trigonal crystals). (b) In accordance with §...

  15. Effects of developmental iron deficiency and post-weaning iron repletion on the levels of iron transporter proteins in rats

    PubMed Central

    Oh, Sugyoung; Shin, Pill-kyung

    2015-01-01

    BACKGROUND/OBJECTIVES Iron deficiency in early life is associated with developmental problems, which may persist until later in life. The question of whether iron repletion after developmental iron deficiency could restore iron homeostasis is not well characterized. In the present study, we investigated the changes of iron transporters after iron depletion during the gestational-neonatal period and iron repletion during the post-weaning period. MATERIALS/METHODS Pregnant rats were provided iron-deficient (< 6 ppm Fe) or control (36 ppm Fe) diets from gestational day 2. At weaning, pups from iron-deficient dams were fed either iron-deficient (ID group) or control (IDR group) diets for 4 week. Pups from control dams were continued to be fed with the control diet throughout the study period (CON). RESULTS Compared to the CON, ID rats had significantly lower hemoglobin and hematocrits in the blood and significantly lower tissue iron in the liver and spleen. Hepatic hepcidin and BMP6 mRNA levels were also strongly down-regulated in the ID group. Developmental iron deficiency significantly increased iron transporters divalent metal transporter 1 (DMT1) and ferroportin (FPN) in the duodenum, but decreased DMT1 in the liver. Dietary iron repletion restored the levels of hemoglobin and hematocrit to a normal range, but the tissue iron levels and hepatic hepcidin mRNA levels were significantly lower than those in the CON group. Both FPN and DMT1 protein levels in the liver and in the duodenum were not different between the IDR and the CON. By contrast, DMT1 in the spleen was significantly lower in the IDR, compared to the CON. The splenic FPN was also decreased in the IDR more than in the CON, although the difference did not reach statistical significance. CONCLUSIONS Our findings demonstrate that iron transporter proteins in the duodenum, liver and spleen are differentially regulated during developmental iron deficiency. Also, post-weaning iron repletion efficiently

  16. Toxicology and safety of Ferrochel and other iron amino acid chelates.

    PubMed

    Jeppsen, R B

    2001-03-01

    Iron is estimated to be deficient in the diets of one fifth of the world's population. Iron is commonly provided as a supplemental nutrient in industrialized countries for uses of choice. In other countries of the world, it may be required as an overt addition to the diet to prevent iron deficiency. This may be accomplished through fortification of a common food. As a micronutrient, iron has a relatively narrow range of safety--whether given as a supplement or fortificant, it must be in a high enough dose to be appreciably absorbed, but low enough to avoid toxicity. This concern can be ameliorated by careful choice of the form of iron administered. A source of iron which has proven to be highly bioavailable, yet regulated by dietary need, is iron chelated with amino acids. The structural integrity and longevity of these compounds have been proven by valid chemical and instrumental tests. Proofs of safety of iron amino acid chelate in the dietary administration of iron to swine in both multigenerational and longevity studies are reported. Formal tests of toxicity utilizing ferrous bisglycinate chelate (Ferrochel) carried out in accordance to US-FDA guidelines are also summarized. Ferrochel has been demonstrated to have a No Observable Adverse Effect Level (NOAEL) of at least 500 mg per kg rat body weight, the highest dose tested. This and other results of the detailed toxicity test, as well as other tests of safety and efficacy, have resulted in the US-FDA acknowledging that this product is Generally Recognized As Safe (GRAS) under its approved conditions of use as a source of iron for food enrichment and fortification purposes.

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

    SciTech Connect

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

    2015-01-24

    Highlights: • Iron accumulation was involved in the acute phase following SAH. • Blockage of MCU could attenuate cellular iron accumulation following SAH. • Blockage of MCU could decrease ROS generation and improve cell energy supply following SAH. • Blockage of MCU could alleviate apoptosis and brain injury following SAH. - Abstract: 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.

  18. The Iron-Iron Carbide Phase Diagram: A Practical Guide to Some Descriptive Solid State Chemistry.

    ERIC Educational Resources Information Center

    Long, Gary J.; Leighly, H. P., Jr.

    1982-01-01

    Discusses the solid state chemistry of iron and steel in terms of the iron-iron carbide phase diagram. Suggests that this is an excellent way of introducing the phase diagram (equilibrium diagram) to undergraduate students while at the same time introducing the descriptive solid state chemistry of iron and steel. (Author/JN)

  19. Early postnatal iron repletion overcomes lasting effects of gestational iron deficiency in rats.

    PubMed

    Beard, John L; Unger, Erica L; Bianco, Laura E; Paul, Tessy; Rundle, Sarah E; Jones, Byron C

    2007-05-01

    Iron deficiency anemia in early childhood causes developmental delays and, very likely, irreversible alterations in neurological functioning. One primary goal for the present study was to determine whether the effects of late gestational iron deficiency on brain monoamine metabolism, iron content, and behavioral phenotypes could be repaired with iron intervention in early lactation. Young pregnant rats were provided iron-deficient or control diets from mid-gestation (G15). At postnatal d 4 (P4), pups from iron-deficient dams were out-fostered either to other ID dams or control dams while pups of control dams were similarly fostered to other control dams. Dietary treatments continued to adulthood (P65) when brain iron and regional monoamines were evaluated. P4 iron repletion normalized body iron status, brain iron concentrations, monoamine concentrations, and monoamine transporter and receptor densities in most brain regions. Dopamine transporter densities in caudate and substantia nigra were lower in ID rats but were normalized with iron repletion. Serotonin transporter levels in most brain regions and open-field exploration were also normalized with iron repletion. The success of this approach of early postnatal iron intervention following iron deficiency in utero contrasts to a relative lack of success when the intervention is performed at weaning. These data suggest that a window of opportunity exists for reversing the detrimental effects of iron deficiency in utero in rats and provides strong support of intervention approaches in humans with iron deficiency during pregnancy.

  20. The role of ceruloplasmin in iron metabolism.

    PubMed

    Roeser, H P; Lee, G R; Nacht, S; Cartwright, G E

    1970-12-01

    The importance of ceruloplasmin in iron metabolism was studied in swine made hypoceruloplasminemic by copper deprivation. When the plasma ceruloplasmin level fell below 1% of normal, cell-to-plasma iron flow became sufficiently impaired to cause hypoferremia, even though total body iron stores were normal. When ceruloplasmin was administered to such animals, plasma iron increased immediately and continued to rise at a rate proportional to the logarithm of the ceruloplasmin dose. The administration of inorganic copper induced increases in plasma iron only after ceruloplasmin appeared in the circulation. Thus, ceruloplasmin appeared to be essential to the normal movement of iron from cells to plasma. Studies designed to define the mechanism of action of ceruloplasmin were based on the in vitro observation that ceruloplasmin behaves as an enzyme (ferroxidase) that catalyzes oxidation of ferrous iron. Retention of injected ferrous iron in the plasma of ceruloplasmin-deficient swine was significantly less than that of ferric iron, reflecting impaired transferrin iron binding. Rat ceruloplasmin, which has little ferroxidase activity, was much less effective than porcine or human ceruloplasmin in inducing increases in plasma iron. These observations suggest that ceruloplasmin acts by virtue of its ferroxidase activity. Eight patients with Wilson's disease were evaluated in order to investigate iron metabolism in a disorder characterized by reduced ceruloplasmin levels. Evidence of iron deficiency was found in six of these, and in five of the six, plasma ceruloplasmin was less than 5% of normal. In comparison, the two patients without evidence of iron deficiency had ceruloplasmin levels of 11 and 18% of normal. It is suggested that iron deficiency tends to occur in those patients with Wilson's disease who have the severest degrees of hypoceruloplasminemia, possibly because of defective transfer of iron from intestinal mucosal cells to plasma.

  1. Intravenous iron-containing products: EMA procrastination.

    PubMed

    2014-07-01

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

  2. Intravenous iron-containing products: EMA procrastination.

    PubMed

    2014-07-01

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

  3. Integrated Means Integrity

    ERIC Educational Resources Information Center

    Odegard, John D.

    1978-01-01

    Describes the operation of the Cessna Pilot Center (CPC) flight training systems. The program is based on a series of integrated activities involving stimulus, response, reinforcement and association components. Results show that the program can significantly reduce in-flight training time. (CP)

  4. Why are biotic iron pools uniform across high- and low-iron pelagic ecosystems?

    NASA Astrophysics Data System (ADS)

    Boyd, P. W.; Strzepek, R. F.; Ellwood, M. J.; Hutchins, D. A.; Nodder, S. D.; Twining, B. S.; Wilhelm, S. W.

    2015-07-01

    Dissolved iron supply is pivotal in setting global phytoplankton productivity and pelagic ecosystem structure. However, most studies of the role of iron have focussed on carbon biogeochemistry within pelagic ecosystems, with less effort to quantify the iron biogeochemical cycle. Here we compare mixed-layer biotic iron inventories from a low-iron (~0.06 nmol L-1) subantarctic (FeCycle study) and a seasonally high-iron (~0.6 nmol L-1) subtropical (FeCycle II study) site. Both studies were quasi-Lagrangian, and had multi-day occupation, common sampling protocols, and indirect estimates of biotic iron (from a limited range of available published biovolume/carbon/iron quotas). Biotic iron pools were comparable (~100 ± 30 pmol L-1) for low- and high-iron waters, despite a tenfold difference in dissolved iron concentrations. Consistency in biotic iron inventories (~80 ± 24 pmol L-1, largely estimated using a limited range of available quotas) was also conspicuous for three Southern Ocean polar sites. Insights into the extent to which uniformity in biotic iron inventories was driven by the need to apply common iron quotas obtained from laboratory cultures were provided from FeCycle II. The observed twofold to threefold range of iron quotas during the evolution of FeCycle II subtropical bloom was much less than reported from laboratory monocultures. Furthermore, the iron recycling efficiency varied by fourfold during FeCycle II, increasing as stocks of new iron were depleted, suggesting that quotas and iron recycling efficiencies together set biotic iron pools. Hence, site-specific differences in iron recycling efficiencies (which provide 20-50% and 90% of total iron supply in high- and low-iron waters, respectively) help offset the differences in new iron inputs between low- and high-iron sites. Future parameterization of iron in biogeochemical models must focus on the drivers of biotic iron inventories, including the differing iron requirements of the resident biota

  5. Regulation of iron transport systems in Enterobacteriaceae in response to oxygen and iron availability.

    PubMed

    Carpenter, Chandra; Payne, Shelley M

    2014-04-01

    Iron is an essential nutrient for most bacteria. Depending on the oxygen available in the surrounding environment, iron is found in two distinct forms: ferrous (Fe(II)) or ferric (Fe(III)). Bacteria utilize different transport systems for the uptake of the two different forms of iron. In oxic growth conditions, iron is found in its insoluble, ferric form, and in anoxic growth conditions iron is found in its soluble, ferrous form. Enterobacteriaceae have adapted to transporting the two forms of iron by utilizing the global, oxygen-sensing regulators, ArcA and Fnr to regulate iron transport genes in response to oxygen.

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

    PubMed Central

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

    2015-01-01

    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

  7. Fate of blood meal iron in mosquitos

    PubMed Central

    Zhou, Guoli; Kohlhepp, Pete; Geiser, Dawn; Frasquillo, Maria del Carmen; Vazquez-Moreno, Luz; Winzerling, Joy J.

    2007-01-01

    Iron is an essential element of living cells and organisms as a component of numerous metabolic pathways. Hemoglobin and ferric-transferrin in vertebrate host blood are the two major iron sources for female mosquitoes. We used inductively coupled plasma mass spectrometry (ICP-MS) and radioisotope-labeling to quantify the fate of iron supplied from hemoglobin or as transferrin in Aedes aegypti. At the end of the first gonotrophic cycloe, ~87% of the ingested total meal heme iron was excreted, while 7% was distributed into the eggs and 6% was stored in different tissues. In contrast, ~8% of the iron provided as transferrin was excreted and of that absorbed, 77% was allocated to the eggs and 15% distributed in the tissues. Further analyses indicate that of the iron supplied in a blood meal, ~7% appears in the eggs and of this iron 98% is from hemoglobin and 2% from ferric-transferrin. Whereas of iron from a blood meal retained in body of the female, ~97% is from heme and <1 % is from transferrin. Evaluation of iron-binding proteins in hemolymph and egg following intake of 59Fe-transferrin revealed that ferritin is iron loaded in these animals, and indicate that this protein plays a critical role in meal iron transport and iron storage in eggs in A. aegypti. PMID:17689557

  8. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No. 1332-37-2), Color Index No. 77491, shall conform...

  9. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... oxide; or (iii) Elemental iron. (2) 200 mg of elemental iron derived from ferric hydroxide. (b) Sponsors... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron injection. 522.1182 Section 522.1182 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1182...

  10. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No. 1332-37-2), Color Index No. 77491, shall conform...

  11. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No. 1332-37-2), Color Index No. 77491, shall conform...

  12. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... oxide; or (iii) Elemental iron. (2) 200 mg of elemental iron derived from ferric hydroxide. (b) Sponsors... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron injection. 522.1182 Section 522.1182 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1182...

  13. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... oxide; or (iii) Elemental iron. (2) 200 mg of elemental iron derived from ferric hydroxide. (b) Sponsors... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron injection. 522.1182 Section 522.1182 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1182...

  14. Iron Deficiency in Autism and Asperger Syndrome.

    ERIC Educational Resources Information Center

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

    2002-01-01

    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…

  15. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron injection. 522.1182 Section 522.1182 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1182 Iron... equivalent of: (1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric hydroxide; (ii)...

  16. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron reduced. 582.5375 Section 582.5375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5375 Iron reduced. (a) Product. Iron reduced. (b) Conditions of use. This substance...

  17. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron reduced. 582.5375 Section 582.5375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5375 Iron reduced. (a) Product. Iron reduced. (b) Conditions of use. This substance...

  18. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Chafing irons. 230.91 Section 230.91 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Tenders Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving...

  19. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron injection. 522.1182 Section 522.1182 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1182 Iron... equivalent of: (1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric hydroxide; (ii)...

  20. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Chafing irons. 230.91 Section 230.91 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Tenders Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving...

  1. Treatment of Iron Deficiency in Women

    PubMed Central

    Breymann, C.; Römer, T.; Dudenhausen, J. W.

    2013-01-01

    Iron deficiency with and without anaemia is a common cause of morbidity, particularly in women. Iron deficiency is generally the result of an imbalance between iron loss and iron absorption. In women with symptoms suspicious for iron deficiency, it is important to confirm or exclude the suspicion using proper tests. The use of serum ferritin levels is considered the gold standard for diagnosis. Although the ideal ferritin levels are not unknown the current consent is that levels < 40 ng/ml indicate iron deficiency, which needs to be treated in symptomatic patients. However, symptoms can already occur at ferritin levels of < 100 ng/ml and treatment must be adapted to the individual patient. Iron supplementation is only indicated in symptomatic patients diagnosed with iron deficiency whose quality of life is affected. It is important to treat iron deficiency together with its causes or risk factors. For example, blood loss from hypermenorrhea should be reduced. Women also need to receive information about the benefits of an iron-rich diet. If oral treatment with iron supplements is ineffective, parenteral iron administration is recommended. PMID:26633902

  2. Ligand iron catalysts for selective hydrogenation

    DOEpatents

    Casey, Charles P.; Guan, Hairong

    2010-11-16

    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.

  3. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity. The color additives iron... per million. (c) Uses and restrictions. Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

  4. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity. The color additives iron... per million. (c) Uses and restrictions. Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

  5. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2250 Iron oxides. (a) Identity. The color additives iron... per million. (c) Uses and restrictions. Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing...

  6. Iron bioaccumulation in mycelium of Pleurotus ostreatus.

    PubMed

    Almeida, Sandra M; Umeo, Suzana H; Marcante, Rafael C; Yokota, Meire E; Valle, Juliana S; Dragunski, Douglas C; Colauto, Nelson B; Linde, Giani A

    2015-03-01

    Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatus mycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L (-1) and glucose at 28.45 g L (-1) . The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L (-1) or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg (-1) produced with iron addition of 300 mg L (-1) . The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L (-1) of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron. PMID:26221108

  7. Voice Modulations in German Ironic Speech

    ERIC Educational Resources Information Center

    Scharrer, Lisa; Christmann, Ursula; Knoll, Monja

    2011-01-01

    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"…

  8. Africa: The Birthplace of Iron Mining.

    ERIC Educational Resources Information Center

    Mutunhu, Tendai

    1981-01-01

    Describes the discovery in Swaziland of the oldest iron mining site known. Before this evidence that it was Africans who discovered iron mining and smelting around 42,000 B.C., it had been believed that the knowledge of iron originated in the Middle East between 550-1500 B.C. (GC)

  9. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Chafing irons. 230.91 Section 230.91 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Tenders Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving...

  10. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Chafing irons. 230.91 Section 230.91 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Tenders Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving...

  11. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Chafing irons. 230.91 Section 230.91 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Tenders Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving...

  12. Micromilling enhances iron bioaccessibility from wholegrain wheat.

    PubMed

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

    2014-11-19

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

  13. Adipocyte iron regulates leptin and food intake

    PubMed Central

    Gao, Yan; Li, Zhonggang; Gabrielsen, J. Scott; Simcox, Judith A.; Lee, Soh-hyun; Jones, Deborah; Cooksey, Bob; Stoddard, Gregory; Cefalu, William T.; McClain, Donald A.

    2015-01-01

    Dietary iron supplementation is associated with increased appetite. Here, we investigated the effect of iron on the hormone leptin, which regulates food intake and energy homeostasis. Serum ferritin was negatively associated with serum leptin in a cohort of patients with metabolic syndrome. Moreover, the same inverse correlation was observed in mice fed a high-iron diet. Adipocyte-specific loss of the iron exporter ferroportin resulted in iron loading and decreased leptin, while decreased levels of hepcidin in a murine hereditary hemochromatosis (HH) model increased adipocyte ferroportin expression, decreased adipocyte iron, and increased leptin. Treatment of 3T3-L1 adipocytes with iron decreased leptin mRNA in a dose-dependent manner. We found that iron negatively regulates leptin transcription via cAMP-responsive element binding protein activation (CREB activation) and identified 2 potential CREB-binding sites in the mouse leptin promoter region. Mutation of both sites completely blocked the effect of iron on promoter activity. ChIP analysis revealed that binding of phosphorylated CREB is enriched at these two sites in iron-treated 3T3-L1 adipocytes compared with untreated cells. Consistent with the changes in leptin, dietary iron content was also directly related to food intake, independently of weight. These findings indicate that levels of dietary iron play an important role in regulation of appetite and metabolism through CREB-dependent modulation of leptin expression. PMID:26301810

  14. Iron bioaccumulation in mycelium of Pleurotus ostreatus

    PubMed Central

    Almeida, Sandra M.; Umeo, Suzana H.; Marcante, Rafael C.; Yokota, Meire E.; Valle, Juliana S.; Dragunski, Douglas C.; Colauto, Nelson B.; Linde, Giani A.

    2015-01-01

    Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatus mycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L −1 and glucose at 28.45 g L −1 . The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L −1 or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg −1 produced with iron addition of 300 mg L −1 . The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L −1 of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron. PMID:26221108

  15. Intravenous iron-dextran: studies on unsaturated iron-binding capacity

    PubMed Central

    Cox, J. S. G.; Moss, G. F.; Bremner, I.; Reason, Janet

    1968-01-01

    A method is described for measuring the plasma unsaturated iron-binding capacity in the presence of very high concentrations of iron as iron-dextran. The procedure utilizes 59Fe to label the apotransferrin with subsequent separation of ionic iron from transferrin-bound iron on an ion exchange or Sephadex G.25 column. The unsaturated iron-binding capacity has been measured in rabbits and dogs after intravenous injection of iron-dextran and in human subjects after total dose infusion of iron-dextran. No evidence of saturation of the unsaturated iron-binding capacity was found even when the plasma iron values were greater than 40,000 μg Fe/100 ml. PMID:5697365

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

    PubMed

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

    2014-01-01

    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.

  17. Coal desulfurization with iron pentacarbonyl

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.

    1979-01-01

    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.

  18. Iron oxides in human spleen.

    PubMed

    Kopáni, Martin; Miglierini, Marcel; Lančok, Adriana; Dekan, Július; Čaplovicová, Mária; Jakubovský, Ján; Boča, Roman; Mrazova, Hedviga

    2015-10-01

    Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 μm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization.

  19. Iron Deficiency and Bariatric Surgery

    PubMed Central

    Jáuregui-Lobera, Ignacio

    2013-01-01

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

  20. Iron oxides in human spleen.

    PubMed

    Kopáni, Martin; Miglierini, Marcel; Lančok, Adriana; Dekan, Július; Čaplovicová, Mária; Jakubovský, Ján; Boča, Roman; Mrazova, Hedviga

    2015-10-01

    Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 μm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization. PMID:26292972

  1. Dynamic transition in supercritical iron

    PubMed Central

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

    2014-01-01

    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

  2. Integrating Art.

    ERIC Educational Resources Information Center

    BCATA Journal for Art Teachers, 1991

    1991-01-01

    These articles focus on art as a component of interdisciplinary integration. (1) "Integrated Curriculum and the Visual Arts" (Anna Kindler) considers various aspects of integration and implications for art education. (2) "Integration: The New Literacy" (Tim Varro) illustrates how the use of technology can facilitate cross-curricular integration.…

  3. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations

    PubMed Central

    de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa

    2016-01-01

    ABSTRACT Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption. PMID:26969708

  4. Mitochondrial iron chelation ameliorates cigarette-smoke induced bronchitis and emphysema in mice

    PubMed Central

    Cloonan, Suzanne M.; Glass, Kimberly; Laucho-Contreras, Maria E.; Bhashyam, Abhiram R.; Cervo, Morgan; Pabón, Maria A.; Konrad, Csaba; Polverino, Francesca; Siempos, Ilias I.; Perez, Elizabeth; Mizumura, Kenji; Ghosh, Manik C.; Parameswaran, Harikrishnan; Williams, Niamh C.; Rooney, Kristen T.; Chen, Zhi-Hua; Goldklang, Monica P.; Yuan, Guo-Cheng; Moore, Stephen C.; Demeo, Dawn L.; Rouault, Tracey A.; D’Armiento, Jeanine M.; Schon, Eric A.; Manfredi, Giovanni; Quackenbush, John; Mahmood, Ashfaq; Silverman, Edwin K.; Owen, Caroline A.; Choi, Augustine M.K.

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is linked to both cigarette smoking and genetic determinants. We have previously identified iron-responsive element binding protein 2 (IRP2) as an important COPD susceptibility gene, with IRP2 protein increased in the lungs of individuals with COPD. Here we demonstrate that mice deficient in Irp2 were protected from cigarette smoke (CS)-induced experimental COPD. By integrating RIP-Seq, RNA-Seq, gene expression and functional enrichment clustering analysis, we identified IRP2 as a regulator of mitochondrial function in the lung. IRP2 increased mitochondrial iron loading and cytochrome c oxidase (COX), which led to mitochondrial dysfunction and subsequent experimental COPD. Frataxin-deficient mice with higher mitochondrial iron loading had impaired airway mucociliary clearance (MCC) and higher pulmonary inflammation at baseline, whereas synthesis of cytochrome c oxidase (Sco2)-deficient mice with reduced COX were protected from CS-induced pulmonary inflammation and impairment of MCC. Mice treated with a mitochondrial iron chelator or mice fed a low-iron diet were protected from CS-induced COPD. Mitochondrial iron chelation also alleviated CS-impairment of MCC, CS-induced pulmonary inflammation and CS-associated lung injury in mice with established COPD, suggesting a critical functional role and potential therapeutic intervention for the mitochondrial-iron axis in COPD. PMID:26752519

  5. Mitochondrial iron chelation ameliorates cigarette smoke-induced bronchitis and emphysema in mice.

    PubMed

    Cloonan, Suzanne M; Glass, Kimberly; Laucho-Contreras, Maria E; Bhashyam, Abhiram R; Cervo, Morgan; Pabón, Maria A; Konrad, Csaba; Polverino, Francesca; Siempos, Ilias I; Perez, Elizabeth; Mizumura, Kenji; Ghosh, Manik C; Parameswaran, Harikrishnan; Williams, Niamh C; Rooney, Kristen T; Chen, Zhi-Hua; Goldklang, Monica P; Yuan, Guo-Cheng; Moore, Stephen C; Demeo, Dawn L; Rouault, Tracey A; D'Armiento, Jeanine M; Schon, Eric A; Manfredi, Giovanni; Quackenbush, John; Mahmood, Ashfaq; Silverman, Edwin K; Owen, Caroline A; Choi, Augustine M K

    2016-02-01

    Chronic obstructive pulmonary disease (COPD) is linked to both cigarette smoking and genetic determinants. We have previously identified iron-responsive element-binding protein 2 (IRP2) as an important COPD susceptibility gene and have shown that IRP2 protein is increased in the lungs of individuals with COPD. Here we demonstrate that mice deficient in Irp2 were protected from cigarette smoke (CS)-induced experimental COPD. By integrating RNA immunoprecipitation followed by sequencing (RIP-seq), RNA sequencing (RNA-seq), and gene expression and functional enrichment clustering analysis, we identified Irp2 as a regulator of mitochondrial function in the lungs of mice. Irp2 increased mitochondrial iron loading and levels of cytochrome c oxidase (COX), which led to mitochondrial dysfunction and subsequent experimental COPD. Frataxin-deficient mice, which had higher mitochondrial iron loading, showed impaired airway mucociliary clearance (MCC) and higher pulmonary inflammation at baseline, whereas mice deficient in the synthesis of cytochrome c oxidase, which have reduced COX, were protected from CS-induced pulmonary inflammation and impairment of MCC. Mice treated with a mitochondrial iron chelator or mice fed a low-iron diet were protected from CS-induced COPD. Mitochondrial iron chelation also alleviated CS-induced impairment of MCC, CS-induced pulmonary inflammation and CS-associated lung injury in mice with established COPD, suggesting a critical functional role and potential therapeutic intervention for the mitochondrial-iron axis in COPD.

  6. Progressive hair straightening using an automated flat iron: function of silicones.

    PubMed

    Dussaud, Anne; Rana, Bhavna; Lam, Hui Tung

    2013-01-01

    An automated hair iron was built with which the hair temperature, contact force of the iron against the hair tress, and gliding speed were controlled. The changes in keratin were characterized by several techniques including differential scanning calorimetry, birefringence measurements, and wet tensile tests. Undamaged curly hair was ironed for several iron cycles at temperatures ranging from 120°C to 175°C and washed between each iron cycle. Irreversible straightening of curly hair was observed and depended on the temperature and the number of cycles. The birefringence data suggested that the straightening was related to a gradual decrease of the microfilament organization. Silicone treatment did not significantly affect the course of microfilament denaturation, but it improved the quality of straightening. It enhanced the fiber alignment under the gliding action of the iron. Progressive thermal straightening may be a promising method to achieve permanent smoothing of curly hair without chemical treatment. Ironing at the onset temperature (∼154°C), before substantial disulfide bond scission occurred, seemed to be a good compromise between process speed, straightening performance, and hair integrity (i.e., reduced loss of cross-linking). PMID:23578835

  7. Mitochondrial iron chelation ameliorates cigarette smoke-induced bronchitis and emphysema in mice.

    PubMed

    Cloonan, Suzanne M; Glass, Kimberly; Laucho-Contreras, Maria E; Bhashyam, Abhiram R; Cervo, Morgan; Pabón, Maria A; Konrad, Csaba; Polverino, Francesca; Siempos, Ilias I; Perez, Elizabeth; Mizumura, Kenji; Ghosh, Manik C; Parameswaran, Harikrishnan; Williams, Niamh C; Rooney, Kristen T; Chen, Zhi-Hua; Goldklang, Monica P; Yuan, Guo-Cheng; Moore, Stephen C; Demeo, Dawn L; Rouault, Tracey A; D'Armiento, Jeanine M; Schon, Eric A; Manfredi, Giovanni; Quackenbush, John; Mahmood, Ashfaq; Silverman, Edwin K; Owen, Caroline A; Choi, Augustine M K

    2016-02-01

    Chronic obstructive pulmonary disease (COPD) is linked to both cigarette smoking and genetic determinants. We have previously identified iron-responsive element-binding protein 2 (IRP2) as an important COPD susceptibility gene and have shown that IRP2 protein is increased in the lungs of individuals with COPD. Here we demonstrate that mice deficient in Irp2 were protected from cigarette smoke (CS)-induced experimental COPD. By integrating RNA immunoprecipitation followed by sequencing (RIP-seq), RNA sequencing (RNA-seq), and gene expression and functional enrichment clustering analysis, we identified Irp2 as a regulator of mitochondrial function in the lungs of mice. Irp2 increased mitochondrial iron loading and levels of cytochrome c oxidase (COX), which led to mitochondrial dysfunction and subsequent experimental COPD. Frataxin-deficient mice, which had higher mitochondrial iron loading, showed impaired airway mucociliary clearance (MCC) and higher pulmonary inflammation at baseline, whereas mice deficient in the synthesis of cytochrome c oxidase, which have reduced COX, were protected from CS-induced pulmonary inflammation and impairment of MCC. Mice treated with a mitochondrial iron chelator or mice fed a low-iron diet were protected from CS-induced COPD. Mitochondrial iron chelation also alleviated CS-induced impairment of MCC, CS-induced pulmonary inflammation and CS-associated lung injury in mice with established COPD, suggesting a critical functional role and potential therapeutic intervention for the mitochondrial-iron axis in COPD. PMID:26752519

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

    PubMed

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

    2013-12-01

    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.

  9. 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 ...

  10. Mammalian target of rapamycin coordinates iron metabolism with iron-sulfur cluster assembly enzyme and tristetraprolin.

    PubMed

    Guan, Peng; Wang, Na

    2014-09-01

    Both iron deficiency and excess are relatively common health concerns. Maintaining the body's levels of iron within precise boundaries is critical for cell functions. However, the difference between iron deficiency and overload is often a question of a scant few milligrams of iron. The mammalian target of rapamycin (mTOR), an atypical Ser/Thr protein kinase, is attracting significant amounts of interest due to its recently described role in iron homeostasis. Despite extensive study, a complete understanding of mTOR function has remained elusive. mTOR can form two multiprotein complexes that consist of mTOR complex 1 (mTORC1) and mTOR complex 2. Recent advances clearly demonstrate that mTORC1 can phosphorylate iron-sulfur cluster assembly enzyme ISCU and affect iron-sulfur clusters assembly. Moreover, mTOR is reported to control iron metabolism through modulation of tristetraprolin expression. It is now well appreciated that the hormonal hepcidin-ferroportin system and the cellular iron-responsive element/iron-regulatory protein regulatory network play important regulatory roles for systemic iron metabolism. Sustained ISCU protein levels enhanced by mTORC1 can inhibit iron-responsive element and iron-regulatory protein binding activities. In this study, hepcidin gene and protein expression in the livers of tristetraprolin knockout mice were dramatically reduced. Here, we highlight and summarize the current understanding of how mTOR pathways serve to modulate iron metabolism and homeostasis as the third iron-regulatory system.

  11. Daily supplementation with iron increases lipid peroxidation in young women with low iron stores.

    PubMed

    King, Sarah M; Donangelo, Carmen M; Knutson, Mitchell D; Walter, Patrick B; Ames, Bruce N; Viteri, Fernando E; King, Janet C

    2008-06-01

    The aim of this study was to determine whether women with low iron stores (plasma ferritin iron supplement for 8 wks at a level commonly used to treat poor iron status develop increased lipid peroxidation as measured by ethane exhalation rates and plasma malondialdehyde. The women served as their own control as pre- and post-supplementation periods were compared. Twelve women participated in the study for a 70-day period and consumed daily iron supplements (98 mg of iron as ferrous sulfate) from day 14 to day 70. Baseline blood and expired air samples were obtained on days 1 and 14; measurements during supplementation were performed on days 56 and 70, that is at 6 and 8 weeks of supplementation. Iron status improved during the iron supplementation period; biochemical indicators of lipid peroxidation also increased. After 6 wks of iron supplementation, serum ferritin almost doubled and body iron more than doubled. Hemoglobin levels increased slightly and other indicators of iron status became normal. However, plasma malondialdehyde (MDA) and breath ethane exhalation rates (BEER) increased by more than 40% between baseline and 6 wks of supplementation; these increases correlated significantly with plasma iron and ferritin levels. MDA was positively correlated with BEER. BEER increased further after 8 wks of iron supplementation. The increased indicators of lipid peroxidation with duration of supplementation and as iron status improved suggest that providing daily nearly 100 mg iron may not be a totally innocuous regimen for correcting iron depletion in women.

  12. Effects of High Dietary HEME Iron and Radiation on Cardiovascular Function

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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

  13. Iron-control additives improve acidizing

    SciTech Connect

    Walker, M.; Dill, W. ); Besler, M. )

    1989-07-24

    Iron sulfide and sulfur precipitation in sour wells can be controlled with iron-sequestering agents and sulfide modifiers. Oil production has been routinely increased in sour wells where precipitation of iron sulfide and elemental sulfur has been brought under control. Production increases have been especially noteworthy on wells that had a history of rapid production decline after acid stimulation. Twenty-fold production increases have been recorded. Key to the production increase has been to increase permeability with: Iron chelating agents that control precipitation of iron sulfide. A sulfide modifier that reduces precipitation of solids in the presence of excessive amounts of hydrogen sulfide and prevents precipitation of elemental sulfur.

  14. Hepcidin in the diagnosis of iron disorders

    PubMed Central

    Girelli, Domenico; Nemeth, Elizabeta

    2016-01-01

    The discovery of the iron-regulatory hormone hepcidin in 2001 has revolutionized our understanding of iron disorders, and its measurement should advance diagnosis/treatment of these conditions. Although several assays have been developed, a gold standard is still lacking, and efforts toward harmonization are ongoing. Nevertheless, promising applications can already be glimpsed, ranging from the use of hepcidin levels for diagnosing iron-refractory iron deficiency anemia to global health applications such as guiding safe iron supplementation in developing countries with high infection burden. PMID:27044621

  15. Metabolic Remodeling in Iron-deficient Fungi

    PubMed Central

    Philpott, Caroline C.; Leidgens, Sebastien; Frey, Avery G.

    2012-01-01

    Eukaryotic cells contain dozens, perhaps hundreds, of iron-dependent proteins, which perform critical functions in nearly every major cellular process. Nutritional iron is frequently available to cells in only limited amounts; thus, unicellular and higher eukaryotes have evolved mechanisms to cope with iron scarcity. These mechanisms have been studied at the molecular level in the model eukaryotes Saccharomyces cerevisiae and Schizosaccharomyces pombe, as well as in some pathogenic fungi. Each of these fungal species exhibits metabolic adaptations to iron deficiency that serve to reduce the cell’s reliance on iron. However, the regulatory mechanisms that accomplish these adaptations differ greatly between fungal species. PMID:22306284

  16. Targeting Iron Homeostasis in Acute Kidney Injury.

    PubMed

    Walker, Vyvyca J; Agarwal, Anupam

    2016-01-01

    Iron is an essential metal involved in several major cellular processes required to maintain life. Because of iron's ability to cause oxidative damage, its transport, metabolism, and storage is strictly controlled in the body, especially in the small intestine, liver, and kidney. Iron plays a major role in acute kidney injury and has been a target for therapeutic intervention. However, the therapies that have been effective in animal models of acute kidney injury have not been successful in human beings. Targeting iron trafficking via ferritin, ferroportin, or hepcidin may offer new insights. This review focuses on the biology of iron, particularly in the kidney, and its implications in acute kidney injury. PMID:27085736

  17. Neurologic manifestations of iron deficiency in childhood.

    PubMed

    Yager, Jerome Y; Hartfield, Dawn S

    2002-08-01

    Iron deficiency is a common disorder in pediatric patients. Although the most common manifestation is that of anemia, iron deficiency is frequently the source of a host of neurologic disorders presenting to general pediatric neurologic practices. These disorders include developmental delay, stroke, breath-holding episodes, pseudotumor cerebri, and cranial nerve palsies. Although frequent, the identification of iron deficiency as part of the differential diagnosis in these disorders is uncommon and frequently goes untreated. The purpose of the current review is to highlight what is understood regarding iron deficiency and it's underlying pathophysiology as it relates to the brain, and the association of iron deficiency with common neurologic pediatric disease.

  18. THE IRON PROJECT & Iron Opacity Project: Evidence of increased opacity for solar plasmas

    NASA Astrophysics Data System (ADS)

    Eissner, W.; Hala, -; Nahar, S.; Pradhan, A.; Bailey, J.

    2015-05-01

    The recently reported measurement1 of opacity of iron plasma at high energy density similar to that in the solar convection zone near the boundary of radiative zone shows enhanced continuum, and the integrated opacity is about 7% higher than that from prediction using the existing Opacity Project (OP) data for photoionization and oscillator strengths. This agrees toward 15% increment of opacity needed to explain the lower abundance of elements determined by 3D spectral analysis of solar observation. However, our later large-scale calculations that included strong resonances due to excitations to highly excited cores states for Fe XVII indicated significant amount of opacity missing in the OP data. We will present our latest findings on the importance of highly excited states on the opacity and how proper inclusion of resonances could enhance the continuum. These will have important impact on the composition of the Sun, the benchmark for astronomical objects. We will also present in progress work under the Iron Project on the collision strengths of Si IX obtained using relativistic effects in the Breit-Pauli R-matrix method and transition probabilities of fine structure transitions in Ti I.*Partial support: NSF, DO.

  19. Parkinson's Disease: The Mitochondria-Iron Link.

    PubMed

    Muñoz, Yorka; Carrasco, Carlos M; Campos, Joaquín D; Aguirre, Pabla; Núñez, Marco T

    2016-01-01

    Mitochondrial dysfunction, iron accumulation, and oxidative damage are conditions often found in damaged brain areas of Parkinson's disease. We propose that a causal link exists between these three events. Mitochondrial dysfunction results not only in increased reactive oxygen species production but also in decreased iron-sulfur cluster synthesis and unorthodox activation of Iron Regulatory Protein 1 (IRP1), a key regulator of cell iron homeostasis. In turn, IRP1 activation results in iron accumulation and hydroxyl radical-mediated damage. These three occurrences-mitochondrial dysfunction, iron accumulation, and oxidative damage-generate a positive feedback loop of increased iron accumulation and oxidative stress. Here, we review the evidence that points to a link between mitochondrial dysfunction and iron accumulation as early events in the development of sporadic and genetic cases of Parkinson's disease. Finally, an attempt is done to contextualize the possible relationship between mitochondria dysfunction and iron dyshomeostasis. Based on published evidence, we propose that iron chelation-by decreasing iron-associated oxidative damage and by inducing cell survival and cell-rescue pathways-is a viable therapy for retarding this cycle. PMID:27293957

  20. Cancer Cells with Irons in the Fire

    PubMed Central

    Bystrom, Laura M.; Rivella, Stefano

    2014-01-01

    Iron is essential for the growth and proliferation of cells, as well as for many biological processes that are important for the maintenance and survival of the human body. However, excess iron is associated with the development of cancer and other pathological conditions, due in part to the pro-oxidative nature of iron and its damaging effects on DNA. Current studies suggest that iron depletion may be beneficial for patients that have diseases associated with iron overload or other iron metabolism disorders that may increase the risk for cancer. On the other hand, studies suggest that cancer cells are more vulnerable to the effects of iron depletion and oxidative stress in comparison to normal cells. Therefore, cancer patients might benefit from treatments that alter both iron metabolism and oxidative stress. This review highlights the pro-oxidant effects of iron, the relationship between iron and cancer development, the vulnerabilities of iron-dependent cancer phenotype, and how these characteristics may be exploited to prevent or treat cancer. PMID:24835768

  1. Parkinson's Disease: The Mitochondria-Iron Link.

    PubMed

    Muñoz, Yorka; Carrasco, Carlos M; Campos, Joaquín D; Aguirre, Pabla; Núñez, Marco T

    2016-01-01

    Mitochondrial dysfunction, iron accumulation, and oxidative damage are conditions often found in damaged brain areas of Parkinson's disease. We propose that a causal link exists between these three events. Mitochondrial dysfunction results not only in increased reactive oxygen species production but also in decreased iron-sulfur cluster synthesis and unorthodox activation of Iron Regulatory Protein 1 (IRP1), a key regulator of cell iron homeostasis. In turn, IRP1 activation results in iron accumulation and hydroxyl radical-mediated damage. These three occurrences-mitochondrial dysfunction, iron accumulation, and oxidative damage-generate a positive feedback loop of increased iron accumulation and oxidative stress. Here, we review the evidence that points to a link between mitochondrial dysfunction and iron accumulation as early events in the development of sporadic and genetic cases of Parkinson's disease. Finally, an attempt is done to contextualize the possible relationship between mitochondria dysfunction and iron dyshomeostasis. Based on published evidence, we propose that iron chelation-by decreasing iron-associated oxidative damage and by inducing cell survival and cell-rescue pathways-is a viable therapy for retarding this cycle.

  2. Parkinson's Disease: The Mitochondria-Iron Link

    PubMed Central

    Carrasco, Carlos M.; Núñez, Marco T.

    2016-01-01

    Mitochondrial dysfunction, iron accumulation, and oxidative damage are conditions often found in damaged brain areas of Parkinson's disease. We propose that a causal link exists between these three events. Mitochondrial dysfunction results not only in increased reactive oxygen species production but also in decreased iron-sulfur cluster synthesis and unorthodox activation of Iron Regulatory Protein 1 (IRP1), a key regulator of cell iron homeostasis. In turn, IRP1 activation results in iron accumulation and hydroxyl radical-mediated damage. These three occurrences—mitochondrial dysfunction, iron accumulation, and oxidative damage—generate a positive feedback loop of increased iron accumulation and oxidative stress. Here, we review the evidence that points to a link between mitochondrial dysfunction and iron accumulation as early events in the development of sporadic and genetic cases of Parkinson's disease. Finally, an attempt is done to contextualize the possible relationship between mitochondria dysfunction and iron dyshomeostasis. Based on published evidence, we propose that iron chelation—by decreasing iron-associated oxidative damage and by inducing cell survival and cell-rescue pathways—is a viable therapy for retarding this cycle. PMID:27293957

  3. Immunity to plant pathogens and iron homeostasis.

    PubMed

    Aznar, Aude; Chen, Nicolas W G; Thomine, Sebastien; Dellagi, Alia

    2015-11-01

    Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity. PMID:26475190

  4. Iron control in the Appalachian Basin

    SciTech Connect

    Dill, W.R.; Fredette, G.

    1983-11-01

    The Appalachian Basin presents one of the most challenging production and stimulation problems because of the iron content of its hydrocarbon producing formations. A variety of iron compounds in the producing formations present problems that have to be considered to effectively stimulate these formations. A research program was initiated in the later part of 1980 to determine methods of more effectively controlling the iron problems in the Appalachian Basin. Results of this study provide data for comparing the effectiveness of various iron control systems that are used in acid stimulation or breakdown techniques that minimize the release of acid insoluble solids and stabilizes them to decrease the detrimental effect caused by fines migration. Also developed in this study was an iron control system that helps the compatibility of the treating fluid with ferrous iron in the formation water. Flow test data and field results indicate the effectiveness of these iron control systems and treating techniques.

  5. Anaemia and iron deficiency disease in children.

    PubMed

    Olivares, M; Walter, T; Hertrampf, E; Pizarro, F

    1999-01-01

    Iron deficiency is the single most common nutritional disorder world-wide and the main cause of anaemia in infancy, childhood and pregnancy. It is prevalent in most of the developing world and it is probably the only nutritional deficiency of consideration in industrialised countries. In the developing world the prevalence of iron deficiency is high, and is due mainly to a low intake of bioavailable iron. However, in this setting, iron deficiency often co-exists with other conditions such as, malnutrition, vitamin A deficiency, folate deficiency, and infection. In tropical regions, parasitic infestation and haemoglobinopathies are also a common cause of anaemia. In the developed world iron deficiency is mainly a single nutritional problem. The conditions previously mentioned might contribute to the development of iron deficiency or they present difficulties in the laboratory diagnosis of iron deficiency.

  6. The Role of Iron and Iron Overload in Chronic Liver Disease

    PubMed Central

    Milic, Sandra; Mikolasevic, Ivana; Orlic, Lidija; Devcic, Edita; Starcevic-Cizmarevic, Nada; Stimac, Davor; Kapovic, Miljenko; Ristic, Smiljana

    2016-01-01

    The liver plays a major role in iron homeostasis; thus, in patients with chronic liver disease, iron regulation may be disturbed. Higher iron levels are present not only in patients with hereditary hemochromatosis, but also in those with alcoholic liver disease, nonalcoholic fatty liver disease, and hepatitis C viral infection. Chronic liver disease decreases the synthetic functions of the liver, including the production of hepcidin, a key protein in iron metabolism. Lower levels of hepcidin result in iron overload, which leads to iron deposits in the liver and higher levels of non-transferrin-bound iron in the bloodstream. Iron combined with reactive oxygen species leads to an increase in hydroxyl radicals, which are responsible for phospholipid peroxidation, oxidation of amino acid side chains, DNA strain breaks, and protein fragmentation. Iron-induced cellular damage may be prevented by regulating the production of hepcidin or by administering hepcidin agonists. Both of these methods have yielded successful results in mouse models. PMID:27332079

  7. A Diatom Ferritin Optimized for Iron Oxidation but Not Iron Storage*

    PubMed Central

    Pfaffen, Stephanie; Bradley, Justin M.; Abdulqadir, Raz; Firme, Marlo R.; Moore, Geoffrey R.; Le Brun, Nick E.; Murphy, Michael E. P.

    2015-01-01

    Ferritin from the marine pennate diatom Pseudo-nitzschia multiseries (PmFTN) plays a key role in sustaining growth in iron-limited ocean environments. The di-iron catalytic ferroxidase center of PmFTN (sites A and B) has a nearby third iron site (site C) in an arrangement typically observed in prokaryotic ferritins. Here we demonstrate that Glu-44, a site C ligand, and Glu-130, a residue that bridges iron bound at sites B and C, limit the rate of post-oxidation reorganization of iron coordination and the rate at which Fe3+ exits the ferroxidase center for storage within the mineral core. The latter, in particular, severely limits the overall rate of iron mineralization. Thus, the diatom ferritin is optimized for initial Fe2+ oxidation but not for mineralization, pointing to a role for this protein in buffering iron availability and facilitating iron-sparing rather than only long-term iron storage. PMID:26396187

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

    PubMed Central

    Hurrell, Richard F.

    2014-01-01

    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

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

    PubMed Central

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

    2015-01-01

    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

  10. High Fat Diet Subverts Hepatocellular Iron Uptake Determining Dysmetabolic Iron Overload

    PubMed Central

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

    2015-01-01

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

  11. Iron storage disease in tapirs.

    PubMed

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

    2006-03-01

    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.

  12. Iron oxidation by Thiobacillus ferrooxidans

    SciTech Connect

    Kang, Sunki; Sproull, R.D.

    1991-12-31

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

  13. F-8 Iron Bird Cockpit

    NASA Technical Reports Server (NTRS)

    1975-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

  15. Current approach to iron chelation in children.

    PubMed

    Aydinok, Yesim; Kattamis, Antonis; Viprakasit, Vip

    2014-06-01

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

  16. Iron and mechanisms of emotional behavior.

    PubMed

    Kim, Jonghan; Wessling-Resnick, Marianne

    2014-11-01

    Iron is required for appropriate behavioral organization. Iron deficiency results in poor brain myelination and impaired monoamine metabolism. Glutamate and γ-aminobutyric acid homeostasis is modified by changes in brain iron status. Such changes produce not only deficits in memory/learning capacity and motor skills, but also emotional and psychological problems. An accumulating body of evidence indicates that both energy metabolism and neurotransmitter homeostasis influence emotional behavior, and both functions are influenced by brain iron status. Like other neurobehavioral aspects, the influence of iron metabolism on mechanisms of emotional behavior is multifactorial: brain region-specific control of behavior, regulation of neurotransmitters and associated proteins, temporal and regional differences in iron requirements, oxidative stress responses to excess iron, sex differences in metabolism, and interactions between iron and other metals. To better understand the role that brain iron plays in emotional behavior and mental health, this review discusses the pathologies associated with anxiety and other emotional disorders with respect to body iron status.

  17. Iron uptake and transport across physiological barriers.

    PubMed

    Duck, Kari A; Connor, James R

    2016-08-01

    Iron is an essential element for human development. It is a major requirement for cellular processes such as oxygen transport, energy metabolism, neurotransmitter synthesis, and myelin synthesis. Despite its crucial role in these processes, iron in the ferric form can also produce toxic reactive oxygen species. The duality of iron's function highlights the importance of maintaining a strict balance of iron levels in the body. As a result, organisms have developed elegant mechanisms of iron uptake, transport, and storage. This review will focus on the mechanisms that have evolved at physiological barriers, such as the intestine, the placenta, and the blood-brain barrier (BBB), where iron must be transported. Much has been written about the processes for iron transport across the intestine and the placenta, but less is known about iron transport mechanisms at the BBB. In this review, we compare the established pathways at the intestine and the placenta as well as describe what is currently known about iron transport at the BBB and how brain iron uptake correlates with processes at these other physiological barriers. PMID:27457588

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

    PubMed

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

    2014-02-28

    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.

  19. Iron-Tolerant Cyanobacteria: Ecophysiology and Fingerprinting

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

  20. Iron, phytoplankton growth, and the carbon cycle.

    PubMed

    Street, Joseph H; Paytan, Adina

    2005-01-01

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

  1. Iron speciation in beans (Phaseolus vulgaris) biofortified by common breeding.

    PubMed

    Hoppler, Matthias; Egli, Ines; Petry, Nicolai; Gille, Doreen; Zeder, Christophe; Walczyk, Thomas; Blair, Matthew W; Hurrell, Richard F

    2014-09-01

    The iron storage protein ferritin is a potential vehicle to enhance the iron content of biofortified crops. With the aim of evaluating the potential of ferritin iron in plant breeding, we used species-specific isotope dilution mass spectrometry to quantify ferritin iron in bean varieties with a wide range of total iron content. Zinc, phytic acid, and polyphenols were also measured. Total iron concentration in 21 bean varieties ranged from 32 to 115 ppm and was positively correlated with concentrations of zinc (P = 0.001) and nonferritin bound iron (P < 0.001). Ferritin iron ranged from 13% to 35% of total iron and increased only slightly in high iron beans (P = 0.007). Concentrations of nonferritin bound iron and phytic acid were correlated (P = 0.001), although phytic acid:iron molar ratio decreased with increasing iron concentration (P = 0.003). Most iron in high iron beans was present as nonferritin bound iron, which confirms our earlier finding showing that ferritin iron in beans was lower than previously published. As the range of ferritin iron content in beans is relatively narrow, there is less opportunity for breeders to breed for high ferritin. The relevance of these findings to the extent of iron absorption depends on resolving the question of whether ferritin iron is absorbed or not to a greater extent than nonferritin bound iron.

  2. Modelling Iron-Bentonite Interactions

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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

  3. Iron Translocation I. Plant Culture, Exudate Sampling, Iron-Citrate Analysis

    PubMed Central

    Tiffin, Lee O.

    1966-01-01

    Plant culture, exudate sampling, and analytical methods designed to ascertain the form of iron translocated are presented. Restoration of iron to sunflower plants precultured at different Fe levels resulted in exudate iron concentrations ranging from 0.2 to 31 × 10−5 m. Citrate was from 3 to 89 × 10−5 m. Iron and citrate were highest in exudates from iron-deficient plants. Citrate/Fe ratios were between 1 and 3 for exudates of deficient plants. Exudate from normal plants gave a citrate/Fe ratio of 15. Malate, iron, and a fraction of the citrate in stem exudates migrated electrophoretically to similar positions in acetate buffer. Extracts of narrow bands from the iron-containing areas gave curves suggesting that citrate bound the iron. Citrate that was not combined with iron migrated in a slower band. The effect of iron on citrate migration was confirmed in several related experiments. The stability of Fe-citrate was demonstrated electrophoretically in malate buffer. Citrate retained iron against malate. Data given in this paper indicate that citrate binds iron in sunflower exudate. The data suggest that citrate carries iron in intact plants. Images PMID:16656281

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

    SciTech Connect

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

    1987-05-01

    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.

  5. Regulation of Iron Acquisition Responses in Plant Roots by a Transcription Factor

    ERIC Educational Resources Information Center

    Bauer, Petra

    2016-01-01

    The presented research hypothesis-driven laboratory exercise teaches advanced undergraduate students state of the art methods and thinking in an integrated molecular physiology context. Students understand the theoretical background of iron acquisition in the model plant "Arabidopsis thaliana." They design a flowchart summarizing the key…

  6. Global survey of Fur binding refines the iron responsive regulon of Pseudomonas syringae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas syringae must sense and respond to a variety of environmental signals and understanding how the bacterium integrates these signals into a physiological response is central to our understanding of this plant pathogen. One important micronutrient for all biological organisms is iron. Pre...

  7. 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...

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

    ERIC Educational Resources Information Center

    Whitman, Maryann

    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…

  9. Iron Chelation Therapy in Myelodysplastic Syndromes

    PubMed Central

    Messa, Emanuela; Cilloni, Daniela; Saglio, Giuseppe

    2010-01-01

    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

  10. Iron absorption from typical Latin American diets.

    PubMed

    Acosta, A; Amar, M; Cornbluth-Szarfarc, S C; Dillman, E; Fosil, M; Biachi, R G; Grebe, G; Hertrampf, E; Kremenchuzky, S; Layrisse, M

    1984-06-01

    The availability and daily absorption of iron was determined by the extrinsic label method in typical lower middle to lower class diets consumed in regions of Argentina, Brazil, Chile, Mexico, Peru, and Venezuela. Differences in iron absorption from meals up to 7-fold, could be attributed to the varying contents of absorption enhancers, eg, in meat, and of inhibitors in tea, vegetables, and wheat or maize bread. The total iron available in the diets from four countries did not meet the physiological requirements for normal subjects but deficient subjects fulfilled their requirements absorbing from 1.0 to 2.1 mg/day. In five diets heme iron (6 to 24% of the total) provided 34 to 73% of the iron absorbed. These data suggest that such absorption and utilization studies may be used to correlate the prevalence of iron deficiency in a population with certain diets and to guide fortification programs.

  11. Photochemical Activation of Chlorine by Iron and Iron Oxide Aerosol

    NASA Astrophysics Data System (ADS)

    Wittmer, J.; Zetzsch, C.

    2015-12-01

    The photochemical activation of chlorine by dissolved iron in sea-salt aerosol droplets and by highly dispersed Fe2O3 aerosol particles (mainly hematite, specific surface > 100 m2/g), exposed to gaseous HCl, was investigated in humidified air in a Teflon simulation chamber. Employing the radical-clock technique, we quantified the production of gaseous atomic Cl. When the artificial sea salt aerosols contained suspended Fe2O3 alone at pH 6, no significant Cl production could be observed, even if the dissolution of iron was forced by "weathering" (repeatedly freezing and thawing for five times). Adjusting the pH in the stock suspension to 2.6, 2.2, and 1.9 and equilibrating for one week resulted in a quantifiable amount of dissolved iron (0.03, 0.2, and 0.6 mmol/L, respectively) and in gaseous Cl production rates of ~1.6, 6, and 8 × 1021 atoms cm-2 h-1, respectively. Exposing the pure Fe2O3 aerosol in the absence of salt to various gaseous HCl concentrations resulted in rates ranging from 8 × 1020 Cl atoms cm-2 h-1 (at ~4 ppb HCl) to 5 × 1022 Cl atoms cm-2 h-1 (at ~350 ppb HCl) and confirmed the uptake and conversion of HCl to atomic Cl (at HCl to Cl conversion yields of 2-5 % mol/mol, depending on the relative humidity). The relevance for environmental processes in the atmosphere will be discussed.

  12. Dependence of intestinal iron absorption on the valency state of iron.

    PubMed

    Wollenberg, P; Rummel, W

    1987-11-01

    1. In rats iron was absorbed after administration into the gut lumen as ferric iron bound to serum albumin, to nitrilotriacetic acid, and to 8-OH-quinoline sulfonic acid, or as isolated diferri-transferrin. 2. Iron absorption from 59Fe-labelled transferrin was inhibited by the addition of rat plasma. 3. The inhibitory component in the rat plasma turned out to be ceruloplasmin (ferrous iron oxidase, EC 1.16.2.1). 4. The absorption of iron from these ferric iron complexes was also inhibited by addition to the incubation medium of ferrozine, a strong anionic Fe(II)-ligand. 5. Uptake and absorptive utilization of transferrin-bound ferric iron was decreased after a prewash of the gut lumen and could be restored by the addition of ascorbate to the incubation medium. 6. The conclusion was drawn from these results that luminal reduction precedes ferric iron absorption and that this is a prerequisite for the uptake into the mucosa.

  13. THE EFFECT OF WATER CHEMISTRY ON THE PROPERTIES OF IRON PARTICLES AND IRON SUSPENSIONS

    EPA Science Inventory

    The structure and properties of iron colloids in aquatic systems is important in understanding their behavior in environmental and engineering systems. For example the adsorption of contaminants onto iron colloids and subsequent transport through ground water aquifers and surface...

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

    PubMed Central

    Santiago, Palacios

    2012-01-01

    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

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

    ERIC Educational Resources Information Center

    Cooter, G. Rankin; Mowbray, Kathy W.

    1978-01-01

    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)

  16. Adsorption of ammonia on multilayer iron phthalocyanine

    SciTech Connect

    Isvoranu, Cristina; Knudsen, Jan; Ataman, Evren; Andersen, Jesper N.; Schnadt, Joachim; Schulte, Karina; Wang Bin; Bocquet, Marie-Laure

    2011-03-21

    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.

  17. Hepcidin and Its Role in Iron Homeostasis

    PubMed Central

    Kwapisz, Justyna; Slomka, Artur

    2009-01-01

    Hepcidin, a small peptide secreted mainly by the liver, plays a central role in iron status regulation. The experiments on hepcidin seemed very promising and gave new life to understanding iron metabolism. Many authors suggest that hepcidin measurement can be used as a clinical tool for the diagnosis and management of a wide range of iron-related disorders. The current review presents data concerning hepcidin, especially its biology, mechanism of action and its role in pathomechanism of many diseases.

  18. [IRON OVERLOAD: BETTER UNDERSTANDING, BETTER CARE].

    PubMed

    Brissot, Pierre

    2015-12-01

    Chronic iron overload, either of genetic (hemochromatoses) or acquired (transfusions) origin, leads to frequent disorders, affecting both the quality of life and life expectancy. Major recent advances in the knowledge of iron metabolism, together with advances in biology, imaging and drug design have already significantly improved the diagnostic and therapeutic approaches. These conceptual and technological ameliorations should, in the near future, continue to benefit the clinical management of iron overloaded patients. PMID:26979029

  19. Surface modification of high temperature iron alloys

    DOEpatents

    Park, Jong-Hee

    1995-01-01

    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.

  20. Surface modification of high temperature iron alloys

    DOEpatents

    Park, J.H.

    1995-06-06

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

  1. High toughness-high strength iron alloy

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    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.

  2. New developments and controversies in iron metabolism and iron chelation therapy.

    PubMed

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-03-26

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  3. New developments and controversies in iron metabolism and iron chelation therapy

    PubMed Central

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-01-01

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients’ therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  4. New developments and controversies in iron metabolism and iron chelation therapy.

    PubMed

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-03-26

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  5. The development of precipitated iron catalysts with improved stability

    SciTech Connect

    Not Available

    1990-01-01

    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.

  6. Structural basis for iron piracy by pathogenic Neisseria

    PubMed Central

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

    2012-01-01

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

  7. Structural basis for iron piracy by pathogenic Neisseria.

    PubMed

    Noinaj, Nicholas; Easley, Nicole C; Oke, Muse; Mizuno, Naoko; Gumbart, James; Boura, Evzen; Steere, Ashley N; Zak, Olga; Aisen, Philip; Tajkhorshid, Emad; Evans, Robert W; Gorringe, Andrew R; Mason, Anne B; Steven, Alasdair C; Buchanan, Susan K

    2012-02-12

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

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

    PubMed

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

    2005-12-01

    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.

  9. Role of manganese in protection against oxidative stress under iron starvation in cyanobacterium Anabaena 7120.

    PubMed

    Kaushik, Manish Singh; Srivastava, Meenakshi; Verma, Ekta; Mishra, Arun Kumar

    2015-06-01

    The cyanobacterium Anabaena sp. PCC 7120 was grown in presence and absence of iron to decipher the role of manganese in protection against the oxidative stress under iron starvation and growth, manganese uptake kinetics, antioxidative enzymes, lipid peroxidation, electrolyte leakage, thiol content, total peroxide, proline and NADH content was investigated. Manganese supported the growth of cyanobacterium Anabaena 7120 under iron deprived conditions where maximum uptake rate of manganese was observed with lower K(m) and higher V(max) values. Antioxidative enzymes were also found to be elevated in iron-starved conditions. Estimation of lipid peroxidation and electrolyte leakage depicted the role of manganese in stabilizing the integrity of the membrane which was considered as the prime target of oxygen free radicals in oxidative stress. The levels of total peroxide, thiol, proline and NADH content, which are the representative of oxidative stress response in Anabaena 7120, were also showed increasing trends in iron starvation. Hence, the results discerned, clearly suggested the role of manganese in protection against the oxidative stress in cyanobacterium Anabaena 7120 under iron starvation either due to its antioxidative properties or involvement as cofactor in a number of antioxidative enzymes.

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

    PubMed

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

    2005-12-01

    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

  11. Calcein as a fluorescent probe for ferric iron. Application to iron nutrition in plant cells.

    PubMed

    Thomas, F; Serratrice, G; Béguin, C; Aman, E S; Pierre, J L; Fontecave, M; Laulhère, J P

    1999-05-01

    The recent use of calcein (CA) as a fluorescent probe for cellular iron has been shown to reflect the nutritional status of iron in mammalian cells (Breuer, W., Epsztejn, S., and Cabantchik, Z. I. (1995) J. Biol. Chem. 270, 24209-24215). CA was claimed to be a chemosensor for iron(II), to measure the labile iron pool and the concentration of cellular free iron(II). We first study here the thermodynamic and kinetic properties of iron binding by CA. Chelation of a first iron(III) involves one aminodiacetic arm and a phenol. The overall stability constant log beta111 of FeIIICAH is 33. 9. The free metal ion concentration is pFeIII = 20.3. A (FeIII)2 CA complex can be formed. A reversible iron(III) exchange from FeIIICAH to citrate and nitrilotriacetic acid is evidenced when these ligands are present in large excess. The kinetics of iron(III) exchange by CA is compatible with metabolic studies. The low reduction potential of FeIIICAH shows that the ferric form is highly stabilized. CA fluorescence is quenched by 85% after FeIII chelation but by only 20% using FeII. Real time iron nutrition by Arabidopsis thaliana cells has been measured by fluorimetry, and the iron buffer FeIIICAH + CA was used as source of iron. As a siderophore, FeIIICAH promotes cell growth and regreening of iron-deficient cells more rapidly than FeIIIEDTA. We conclude that CA is a good chemosensor for iron(III) in cells and biological fluids, but not for Fe(II). We discuss the interest of quantifying iron buffers in biochemical studies of iron, in vitro as well as in cells.

  12. Voronoi analysis of the short-range atomic structure in iron and iron-carbon melts

    NASA Astrophysics Data System (ADS)

    Sobolev, Andrey; Mirzoev, Alexander

    2015-08-01

    In this work, we simulated the atomic structure of liquid iron and iron-carbon alloys by means of ab initio molecular dynamics. Voronoi analysis was used to highlight changes in the close environments of Fe atoms as carbon concentration in the melt increases. We have found, that even high concentrations of carbon do not affect short-range atomic order of iron atoms — it remains effectively the same as in pure iron melts.

  13. Efficacy and safety of intravenous iron sucrose in treating adults with iron deficiency anemia

    PubMed Central

    Cançado, Rodolfo Delfini; de Figueiredo, Pedro Otavio Novis; Olivato, Maria Cristina Albe; Chiattone, Carlos Sérgio

    2011-01-01

    Background Iron deficiency is the most common disorder in the world, affecting approximately 25% of the world`s population and the most common cause of anemia. Objective To evaluate the efficacy and safety of intravenous iron sucrose (IS) in the treatment of adults with iron deficiency anemia Methods Eighty-six adult patients with iron deficiency anemia, who had intolerance or showed no effect with oral iron therapy, received a weekly dose of 200 mg of intravenous iron sucrose until the hemoglobin level was corrected or until receiving the total dose of intravenous iron calculated for each patient Results The mean hemoglobin and serum ferritin levels were 8.54 g/dL and 7.63 ng/mL (pre-treatment) and 12.1 g/dL and 99.0 ng/mL (post-treatment) (p-value < 0.0001), respectively. The average increases in hemoglobin levels were 3.29 g/dL for women and 4.58 g/dL for men; 94% of male and 84% of female patients responded (hemoglobin increased by at least 2 g/dL) to intravenous iron therapy. Correction of anemia was obtained in 47 of 69 (68.1%) female patients and in 12 of 17 male (70.6%) patients. A total of 515 intravenous infusions of iron sucrose were administered and iron sucrose was generally well tolerated with no moderate or serious adverse drug reactions recorded by the investigators. Conclusions Our data confirm that the use of intravenous iron sucrose is a safe and effective option in the treatment of adult patients with iron deficiency anemia who lack satisfactory response to oral iron therapy. Intravenous iron sucrose is well tolerated and with a clinically manageable safety profile when using appropriate dosing and monitoring. The availability of intravenous iron sucrose would potentially improve compliance and thereby reduce morbidities from iron deficiency. PMID:23049360

  14. Method for producing iron-based catalysts

    DOEpatents

    Farcasiu, Malvina; Kaufman, Phillip B.; Diehl, J. Rodney; Kathrein, Hendrik

    1999-01-01

    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.

  15. Hepatocellular carcinoma and African iron overload.

    PubMed Central

    Gangaidzo, I T; Gordeuk, V R

    1995-01-01

    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

  16. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    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 (μXRF) 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.

  17. Ferrous iron transport in Streptococcus mutans

    SciTech Connect

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

    1986-12-01

    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.

  18. Epigenetic regulation of iron homeostasis in Arabidopsis.

    PubMed

    Xing, Jiewen; Wang, Tianya; Ni, Zhongfu

    2015-01-01

    Iron (Fe) is one of the most important microelement required for plant growth and development because of its unique property of catalyzing oxidation/reduction reactions. Iron deficiency impairs fundamental processes which could lead to a decrease in chlorophyll production and pollen fertility, thus influencing crop productivity and quality. However, iron in excess is toxic to the cell and is harmful to the plant. To exactly control the iron content in all tissues, plants have evolved many strategies to regulate iron homeostasis, which refers to 2 successive steps: iron uptake at the root surface, and iron distribution in vivo. In the last decades, a number of transporters and regulatory factors involved in this process have been isolated and identified. To cope with the complicated flexible environmental conditions, plants apply diverse mechanisms to regulate the expression and activity of these components. One of the most important mechanisms is epigenetic regulation of iron homeostasis. This review has been presented to provide an update on the information supporting the involvement of histone modifications in iron homeostasis and possible future course of the field. PMID:26313698

  19. Brain iron deposits and lifespan cognitive ability.

    PubMed

    Del C Valdés Hernández, Maria; Ritchie, Stuart; Glatz, Andreas; Allerhand, Mike; Muñoz Maniega, Susana; Gow, Alan J; Royle, Natalie A; Bastin, Mark E; Starr, John M; Deary, Ian J; Wardlaw, Joanna M

    2015-10-01

    Several studies have reported associations between brain iron deposits and cognitive status, and cardiovascular and neurodegenerative diseases in older individuals, but the mechanisms underlying these associations remain unclear. We explored the associations between regional brain iron deposits and different factors of cognitive ability (fluid intelligence, speed and memory) in a large sample (n = 662) of individuals with a mean age of 73 years. Brain iron deposits in the corpus striatum were extracted automatically. Iron deposits in other parts of the brain (i.e., white matter, thalamus, brainstem and cortex), brain tissue volume and white matter hyperintensities (WMH) were assessed separately and semi-automatically. Overall, 72.8 % of the sample had iron deposits. The total volume of iron deposits had a small but significant negative association with all three cognitive ability factors in later life (mean r = -0.165), but no relation to intelligence in childhood (r = 0.043, p = 0.282). Regression models showed that these iron deposit associations were still present after control for a variety of vascular health factors, and were separable from the association of WMH with cognitive ability. Iron deposits were also associated with cognition across the lifespan, indicating that they are relevant for cognitive ability only at older ages. Iron deposits might be an indicator of small vessel disease that affects the neuronal networks underlying higher cognitive functioning.

  20. Acute iron poisoning. Rescue with macromolecular chelators.

    PubMed Central

    Mahoney, J R; Hallaway, P E; Hedlund, B E; Eaton, J W

    1989-01-01

    Acute iron intoxication is a frequent, sometimes life-threatening, form of poisoning. Present therapy, in severe cases, includes oral and intravenous administration of the potent iron chelator, deferoxamine. Unfortunately, high dose intravenous deferoxamine causes acute hypotension additive with that engendered by the iron poisoning itself. To obviate this problem, we have covalently attached deferoxamine to high molecular weight carbohydrates such as dextran and hydroxyethyl starch. These macromolecular forms of deferoxamine do not cause detectable decreases in blood pressure of experimental animals, even when administered intravenously in very large doses, and persist in circulation much longer than the free drug. These novel iron-chelating substances, but not deferoxamine itself, will prevent mortality from otherwise lethal doses of iron administered to mice either orally or intraperitoneally. Further reflecting this enhanced therapeutic efficacy, the high molecular weight iron chelators also abrogate iron-mediated hepatotoxicity, suppressing the release of alanine aminotransferase. We conclude that high molecular weight derivatives of deferoxamine hold promise for the effective therapy of acute iron intoxication and may also be useful in other clinical circumstances in which control of free, reactive iron is therapeutically desirable. PMID:2794068

  1. Characterization of tetraethylene glycol passivated iron nanoparticles

    NASA Astrophysics Data System (ADS)

    Nunes, Eloiza da Silva; Viali, Wesley Renato; da Silva, Sebastião William; Coaquira, José Antonio Huamaní; Garg, Vijayendra Kumar; de Oliveira, Aderbal Carlos; Morais, Paulo César; Jafelicci Júnior, Miguel

    2014-10-01

    The present study describes the synthesis and characterization of iron@iron oxide nanoparticles produced by passivation of metallic iron in tetraethylene glycol media. Structural and chemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Mössbauer spectroscopy. Pomegranate-like core@shell nanoparticulate material in the size range of 90-120 nm was obtained. According to quantitative phase analysis using Rietveld structure refinement the synthesized iron oxide was identified as magnetite (Fe3O4) whereas the iron to magnetite mass fractions was found to be 47:53. These findings are in good agreement with the data obtained from Mössbauer and thermal gravimetric analysis (TGA). The XPS data revealed the presence of a surface organic layer with higher hydrocarbon content, possibly due to the tetraethylene glycol thermal degradation correlated with iron oxidation. The room-temperature (300 K) saturation magnetization measured for the as-synthesized iron and for the iron-iron oxide were 145 emu g-1 and 131 emu g-1, respectively. The measured saturation magnetizations are in good agreement with data obtained from TEM, XRD and Mössbauer spectroscopy.

  2. Iron status and cellular immune competence.

    PubMed

    Good, M F; Powell, L W; Halliday, J W

    1988-03-01

    There is increasing evidence that both iron overload and iron deficiency are associated with significant abnormalities of immune function. In diseases associated with iron overload there is increased susceptibility to both infection and neoplasia. The precise mechanisms are still being unravelled but iron overload has been shown to impair antigen-specific immune responses and to reduce the number of functional helper precursor cells. Similarly, iron in vitro in concentrations reported to be present in the serum of patients with iron overload impairs the generation of cytotoxic T-cells, enhances suppressor T-cell activity and reduces the proliferative capacity of helper T-cells. The predominant tumor seen in iron overload is primary hepatocellular carcinoma; however other aetiological factors appear to be involved in addition to iron overload, especially hepatic cirrhosis. Nevertheless, primary liver cancer occurs much more frequently in hemochromatosis than in other forms of cirrhosis. Iron deficiency is associated with an altered response to infection but the relationship is again a complex one. The cellular mechanisms involved have yet to be clearly defined, although impaired T and B cell function have been demonstrated.

  3. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    SciTech Connect

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

    2010-06-22

    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.

  4. [Iron stores status at early pregnancy].

    PubMed

    Barón, María Adela; Solano, Liseti; Peña, Evelyn; Del Real, Sara

    2005-06-01

    Iron deficiency is the most common cause of nutritional anemia. During pregnancy there is a high risk of developing it, due to the increase of iron requirements for fetal and maternal tissues growth. The objective of this study was to determine the iron nutritional status in early pregnancy and to determine its relationship with the dietary intake. The study applied a cross-sectional and descriptive design in 419 pregnant women (13-41 y) from Valencia, Carabobo, Venezuela. Serum ferritin was determined by enzimoinmunoassay and hemoglobin by a semi-automated method. Dietary iron intake was assessed through two non-consecutive 24 hours recalls. Statistical analysis included basic descriptives, Fisher exact test, Chi-square, and Mann-Whitney tests; with a statistical significance of p < 0.05. The iron deficiency and anemia prevalence were 16.2% and 14.4%, respectively; corresponding 36.6% to ferropenic anemia. 10.4%, 29.0% and 24.2% of the women had deficient intake for iron, vitamin C and A, respectively. There were no significant differences by age. A nutritional risk was observed regarding the iron status, demonstrated by the percentage of ferropenic anemia and because the main dietary contribution came from non-heme iron, which has low bioavailability. Additionally, there was an important percentage of inadequate vitamin C and A intakes; hence, their contribution to iron absorption was limited.

  5. Iron overload in hematopoietic cell transplantation.

    PubMed

    Majhail, N S; Lazarus, H M; Burns, L J

    2008-06-01

    Iron overload, primarily related to RBC transfusions, is a relatively common complication in hematopoietic cell transplant (HCT) recipients. Iron overload increases the risk of infections, veno-occlusive disease and hepatic dysfunction post transplant. Elevated pretransplant ferritin levels have been reported to increase the risk of nonrelapse mortality following HCT and might influence the risk of acute and chronic GVHD. Serum ferritin is sensitive but not specific for iron overload and is a poor predictor of body iron burden. Estimation of hepatic iron content with a liver biopsy or magnetic resonance imaging should be considered prior to initiating therapy for post transplant iron overload. A subgroup of transplant survivors with mild iron overload and no end-organ damage may not need therapy. Phlebotomy is the treatment of choice with iron-chelation therapy reserved for patients not eligible for phlebotomy. Natural history, evolution and treatment of iron overload in transplant survivors have not been adequately investigated and more studies are needed to determine its impact on short-term and long-term morbidity and mortality. PMID:18438425

  6. Epigenetic regulation of iron homeostasis in Arabidopsis.

    PubMed

    Xing, Jiewen; Wang, Tianya; Ni, Zhongfu

    2015-01-01

    Iron (Fe) is one of the most important microelement required for plant growth and development because of its unique property of catalyzing oxidation/reduction reactions. Iron deficiency impairs fundamental processes which could lead to a decrease in chlorophyll production and pollen fertility, thus influencing crop productivity and quality. However, iron in excess is toxic to the cell and is harmful to the plant. To exactly control the iron content in all tissues, plants have evolved many strategies to regulate iron homeostasis, which refers to 2 successive steps: iron uptake at the root surface, and iron distribution in vivo. In the last decades, a number of transporters and regulatory factors involved in this process have been isolated and identified. To cope with the complicated flexible environmental conditions, plants apply diverse mechanisms to regulate the expression and activity of these components. One of the most important mechanisms is epigenetic regulation of iron homeostasis. This review has been presented to provide an update on the information supporting the involvement of histone modifications in iron homeostasis and possible future course of the field.

  7. Regulation of iron acquisition responses in plant roots by a transcription factor.

    PubMed

    Bauer, Petra

    2016-09-10

    The presented research hypothesis-driven laboratory exercise teaches advanced undergraduate students state of the art methods and thinking in an integrated molecular physiology context. Students understand the theoretical background of iron acquisition in the model plant Arabidopsis thaliana. They design a flowchart summarizing the key steps of the experimental approach. Students are made familiar with current techniques such as qPCR. Following their experimental outline, students grow Arabidopsis seedlings up to the age of six days under sufficient and deficient iron supply. The Arabidopsis plants are of two different genotypes, namely wild type and fit loss of function mutants. fit mutants lack the essential transcription factor FIT, required for iron acquisition and plant growth. Students monitor growth phenotypes and root iron reductase activity in a quantitative and qualitative manner. Then, students determine gene expression regulation of FIT, FRO2, and a reference gene by reverse transcription-quantitative PCR (RT-qPCR). Finally, students interpet their results and build a model summarizing the connections between morphological, physiological and molecular iron deficiency responses. Learning outcomes and suggestions for integrating the course concept are explained. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(5):438-449, 2016.

  8. Regulation of iron acquisition responses in plant roots by a transcription factor.

    PubMed

    Bauer, Petra

    2016-09-10

    The presented research hypothesis-driven laboratory exercise teaches advanced undergraduate students state of the art methods and thinking in an integrated molecular physiology context. Students understand the theoretical background of iron acquisition in the model plant Arabidopsis thaliana. They design a flowchart summarizing the key steps of the experimental approach. Students are made familiar with current techniques such as qPCR. Following their experimental outline, students grow Arabidopsis seedlings up to the age of six days under sufficient and deficient iron supply. The Arabidopsis plants are of two different genotypes, namely wild type and fit loss of function mutants. fit mutants lack the essential transcription factor FIT, required for iron acquisition and plant growth. Students monitor growth phenotypes and root iron reductase activity in a quantitative and qualitative manner. Then, students determine gene expression regulation of FIT, FRO2, and a reference gene by reverse transcription-quantitative PCR (RT-qPCR). Finally, students interpet their results and build a model summarizing the connections between morphological, physiological and molecular iron deficiency responses. Learning outcomes and suggestions for integrating the course concept are explained. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(5):438-449, 2016. PMID:27027408

  9. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation Other Regulations Relating to Transportation... Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron...

  10. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation Other Regulations Relating to Transportation... Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron...

  11. 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...

  12. Intravenous iron, inflammation, and oxidative stress: is iron a friend or an enemy of uremic patients?

    PubMed

    Garneata, Liliana

    2008-01-01

    Intravenous iron supplementation is a recognized therapy for anemia in chronic hemodialysis patients, especially in those treated with erythropoietin. The vast majority of patients with chronic kidney disease (CKD) seem to be iron-deficient, as evaluated by the usual parameters and by iron staining on bone marrow biopsy, because of multiple forms of interference with all phases of iron metabolism. The need for iron supplementation in CKD patients becomes obvious. Intravenous iron was demonstrated to be superior to oral iron in hemodialysis patients. There is also evidence for the superiority of intravenous iron in peritoneal dialysis and in nondialysis-dependent CKD patients. On the other hand, intravenous iron could promote cytotoxicity and tissue injury, and exacerbate oxidative stress and thus endothelial dysfunction, as well as inflammation and the progression of both CKD and cardiovascular disease. Nevertheless, correction of anemia is effective in reducing oxidative stress and, consequently, cardiovascular risk. The overall risk-benefit ratio favors the use of intravenous iron alone or with an erythropoietic stimulating agent in the management of renal anemia. Clinical judgment is necessary in each individual case to diagnose iron deficiency and effectively use intravenous iron.

  13. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation Other Regulations Relating to Transportation... Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron...

  14. Obesity Alters Adipose Tissue Macrophage Iron Content and Tissue Iron Distribution

    PubMed Central

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

    2014-01-01

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

  15. Studies on the reduction kinetics of hematite iron ore pellets with noncoking coals for sponge iron plants

    SciTech Connect

    Kumar, M.; Mohapatra, P.; Patel, S.K.

    2009-07-01

    In the present investigation, fired pellets were made by mixing hematite iron ore fines of -100, -16+18, and -8+10 mesh size in different ratios and studies on their reduction kinetics in Lakhanpur, Orient OC-2 and Belpahar coals were carried out at temperatures ranging from 850{sup o}C to 1000{sup o}C with a view toward promoting the massive utilization of fines in ironmaking. The rate of reduction in all the fired iron ore pellets increased markedly with an increase in temperature up to 1000{sup o}C, and it was more intense in the first 30min. The values of activation energy, calculated from integral and differential approaches, for the reduction of fired pellets (prepared from iron ore fines of -100 mesh size) in coals were found to be in the range 131-148 and 130-181 kJ mol{sup -1} (for =0.2 to 0.8), indicating the process is controlled by a carbon gasification reaction. The addition of selected larger size particles in the matrix of -100 mesh size fines up to the extent studied decreased the activation energy and slightly increased the reduction rates of resultant fired pellets. In comparison to coal, the reduction of fired pellets in char was characterized by significantly lower reduction rates and higher activation energy.

  16. Electron spectroscopy of iron disilicide

    NASA Astrophysics Data System (ADS)

    Parshin, A. S.; Igumenov, A. Yu.; Mikhlin, Yu. L.; Pchelyakov, O. P.; Zhigalov, V. S.

    2016-09-01

    We have reported on the results of a complex investigation of iron disilicide FeSi2 using characteristic electron energy loss spectroscopy, inelastic electron scattering cross section spectroscopy, and X-ray photoelectron spectroscopy. It has been shown that the main peak in the spectra of inelastic electron scattering for FeSi2 is a superposition of two unresolved peaks, viz., surface and bulk plasmons. An analysis of the fine structure of the spectra of inelastic electron scattering cross section by their decomposition into Lorentzlike Tougaard peaks has made it possible to quantitatively estimate the contributions of individual energy loss processes to the resulting spectrum and determine their origin and energy.

  17. Iron mobilization in North African dust.

    SciTech Connect

    Ito, A.; Feng, Y.

    2011-01-01

    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

  18. Teaching Integrity

    ERIC Educational Resources Information Center

    Saunders, Sue; Butts, Jennifer Lease

    2011-01-01

    Integrity is one of those essential yet highly ambiguous concepts. For the purpose of this chapter, integrity is defined as that combination of both attributes and actions that makes entities appear to be whole and ethical, as well as consistent. Like the concepts of leadership or wisdom or community or collaboration, integrity is a key element of…

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

    NASA Astrophysics Data System (ADS)

    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

    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 μm), medium (30-60 μm), and large (>60 μm) diatoms is consistent with growth physiology determined for single species in natural seawater. The minimum level of "dissolved" Fe (filtrate < 0.2 μm) 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

  20. Plant mechanisms of siderophore-iron utilization

    SciTech Connect

    Crowley, D.E.

    1986-01-01

    Mechanisms of siderophore iron-utilization by plants were examined to determine whether plants have direct mechanisms for acquiring iron from microbially-produced hydroxamate siderophores or simply take up inorganic iron in equilibrium with the chelate (shuttle mechanism). Experiments were designed to determine whether the monocot plant species, oat (Avena sativa L. cv. Victory) could acquire iron from ferrichrome under hydroponic conditions in which iron uptake was most likely to occur by direct use of the chelating agent. Ten-day-old iron-deficient seedlings, grown in aerated Hoagland's nutrient solution (minus iron) buffered at pH 7.4 with CaCO/sub 3/, were placed in fresh nutrient solution containing 10/sup -7.4/M radioactive /sup 55/FeCl/sub 3/ (23.7 mCi/mg) with the synthetic chelate, EDDHA (10..pi../sup 5/M), ferrichrome (10/sup -5/M), or with no chelate. After 6 days, shoot content of /sup 55/Fe in shoots of plants provided with ferrichrome was 100-fold greater than that in shoots of plants provided with EDDHA. Therefore iron uptake by oat under these conditions not only indicates direct use of ferrichrome, but also suggest that oat may be better able to acquire iron from siderophores than from synthetic chelates. One possible mechanism for direct use of chelating agents, may involve siderophore binding sites on the plasmalemma of root cortical cells where iron is split from the chelate by enzymatic reduction of ferric to ferrous iron. To demonstrate hypothesized siderophore binding sites on oat roots, experiments examined possible competition for presumed siderophore binding sites by an inert analog of ferrichrome constructed by irreversible chelation with chromium.

  1. Pathogenic Mechanisms Underlying Iron Deficiency and Iron Overload: New Insights for Clinical Application

    PubMed Central

    van Velden, DP; van Rensburg, SJ; Erasmus, R

    2009-01-01

    Iron uptake, utilisation, release and storage occur at the gene level. Individuals with variant forms of genes involved in iron metabolism may have different requirements for iron and are likely to respond differently to the same amount of iron in the diet, a concept termed nutrigenetics. Iron deficiency, iron overload and the anemia of inflammation are the commonest iron-related disorders. While at least four types of hereditary iron overload have been identified to date, our knowledge of the genetic basis and consequences of inherited iron deficiency remain limited. The importance of genetic risk factors in relation to iron overload was highlighted with the identification of the HFE gene in 1996. Deleterious mutations in this gene account for 80-90% of inherited iron overload and are associated with loss of iron homeostasis, alterations in inflammatory responses, oxidative stress and in its most severe form, the disorder hereditary haemochromatosis (HH). Elucidation of the genetic basis of HH has led to rapid clinical benefit through drastic reduction in liver biopsies performed as part of the diagnostic work-up of affected patients. Today, detection of a genetic predisposition in the presence of high serum ferritin and transferrin saturation levels is usually sufficient to diagnose HH, thereby addressing the potential danger of inherited iron overload which starts with the same symptoms as iron deficiency, namely chronic fatigue. This review provides the scientific back-up for application of pathology supported genetic testing, a new test concept that is well placed for optimizing clinical benefit to patients with regard to iron status.

  2. Nitrate-dependent iron oxidation limits iron transport in anoxic ocean regions

    NASA Astrophysics Data System (ADS)

    Scholz, Florian; Löscher, Carolin R.; Fiskal, Annika; Sommer, Stefan; Hensen, Christian; Lomnitz, Ulrike; Wuttig, Kathrin; Göttlicher, Jörg; Kossel, Elke; Steininger, Ralph; Canfield, Donald E.

    2016-11-01

    Iron is an essential element for life on Earth and limits primary production in large parts of the ocean. Oxygen-free continental margin sediments represent an important source of bioavailable iron to the ocean, yet little of the iron released from the seabed reaches the productive sea surface. Even in the anoxic water of oxygen minimum zones, where iron solubility should be enhanced, most of the iron is rapidly re-precipitated. To constrain the mechanism(s) of iron removal in anoxic ocean regions we explored the sediment and water in the oxygen minimum zone off Peru. During our sampling campaign the water column featured two distinct redox boundaries separating oxic from nitrate-reducing (i.e., nitrogenous) water and nitrogenous from weakly sulfidic water. The sulfidic water mass in contact with the shelf sediment contained elevated iron concentrations >300 nM. At the boundary between sulfidic and nitrogenous conditions, iron concentrations dropped sharply to <20 nM coincident with a maximum in particulate iron concentration. Within the iron gradient, we found an increased expression of the key functional marker gene for nitrate reduction (narG). Part of this upregulation was related to the activity of known iron-oxidizing bacteria. Collectively, our data suggest that iron oxidation and removal is induced by nitrate-reducing microbes, either enzymatically through anaerobic iron oxidation or by providing nitrite for an abiotic reaction. Given the important role that iron plays in nitrogen fixation, photosynthesis and respiration, nitrate-dependent iron oxidation likely represents a key-link between the marine biogeochemical cycles of nitrogen, oxygen and carbon.

  3. Planktonic marine iron oxidizers drive iron mineralization under low-oxygen conditions.

    PubMed

    Field, E K; Kato, S; Findlay, A J; MacDonald, D J; Chiu, B K; Luther, G W; Chan, C S

    2016-09-01

    Observations of modern microbes have led to several hypotheses on how microbes precipitated the extensive iron formations in the geologic record, but we have yet to resolve the exact microbial contributions. An initial hypothesis was that cyanobacteria produced oxygen which oxidized iron abiotically; however, in modern environments such as microbial mats, where Fe(II) and O2 coexist, we commonly find microaerophilic chemolithotrophic iron-oxidizing bacteria producing Fe(III) oxyhydroxides. This suggests that such iron oxidizers could have inhabited niches in ancient coastal oceans where Fe(II) and O2 coexisted, and therefore contributed to banded iron formations (BIFs) and other ferruginous deposits. However, there is currently little evidence for planktonic marine iron oxidizers in modern analogs. Here, we demonstrate successful cultivation of planktonic microaerophilic iron-oxidizing Zetaproteobacteria from the Chesapeake Bay during seasonal stratification. Iron oxidizers were associated with low oxygen concentrations and active iron redox cycling in the oxic-anoxic transition zone (<3 μm O2 , <0.2 μm H2 S). While cyanobacteria were also detected in this transition zone, oxygen concentrations were too low to support significant rates of abiotic iron oxidation. Cyanobacteria may be providing oxygen for microaerophilic iron oxidation through a symbiotic relationship; at high Fe(II) levels, cyanobacteria would gain protection against Fe(II) toxicity. A Zetaproteobacteria isolate from this site oxidized iron at rates sufficient to account for deposition of geologic iron formations. In sum, our results suggest that once oxygenic photosynthesis evolved, microaerophilic chemolithotrophic iron oxidizers were likely important drivers of iron mineralization in ancient oceans. PMID:27384464

  4. SIRT3 regulates cellular iron metabolism and cancer growth by repressing iron regulatory protein 1.

    PubMed

    Jeong, S M; Lee, J; Finley, L W S; Schmidt, P J; Fleming, M D; Haigis, M C

    2015-04-16

    Iron metabolism is essential for many cellular processes, including oxygen transport, respiration and DNA synthesis, and many cancer cells exhibit dysregulation in iron metabolism. Maintenance of cellular iron homeostasis is regulated by iron regulatory proteins (IRPs), which control the expression of iron-related genes by binding iron-responsive elements (IREs) of target mRNAs. Here, we report that mitochondrial SIRT3 regulates cellular iron metabolism by modulating IRP1 activity. SIRT3 loss increases reactive oxygen species production, leading to elevated IRP1 binding to IREs. As a consequence, IRP1 target genes, such as the transferrin receptor (TfR1), a membrane-associated glycoprotein critical for iron uptake and cell proliferation, are controlled by SIRT3. Importantly, SIRT3 deficiency results in a defect in cellular iron homeostasis. SIRT3 null cells contain high levels of iron and lose iron-dependent TfR1 regulation. Moreover, SIRT3 null mice exhibit higher levels of iron and TfR1 expression in the pancreas. We found that the regulation of iron uptake and TfR1 expression contribute to the tumor-suppressive activity of SIRT3. Indeed, SIRT3 expression is negatively correlated with TfR1 expression in human pancreatic cancers. SIRT3 overexpression decreases TfR1 expression by inhibiting IRP1 and represses proliferation in pancreatic cancer cells. Our data uncover a novel role of SIRT3 in cellular iron metabolism through IRP1 regulation and suggest that SIRT3 functions as a tumor suppressor, in part, by modulating cellular iron metabolism. PMID:24909164

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

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

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

  6. 20. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON ...

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

    20. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON GREY IRON UNIT NO. 1 MOLD CONVEYOR. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  7. 19. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON ...

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

    19. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON GREY IRON UNIT NO. 1 MOLD CONVEYOR. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  8. Anemia caused by low iron - infants and toddlers

    MedlinePlus

    ... is absorbed better when it is in breast milk. Formula with iron added (iron fortified) also provides ... Infants younger than 12 months who drink cow's milk rather than breast milk or iron-fortified formula ...

  9. The relationship between the iron isotopic composition of human whole blood and iron status parameters.

    PubMed

    Van Heghe, Lana; Delanghe, Joris; Van Vlierberghe, Hans; Vanhaecke, Frank

    2013-11-01

    As the iron status of an individual cannot be adequately assessed on the basis of the (total) Fe concentration in whole blood or serum, in medicine a number of parameters, such as the serum concentrations of ferritin, transferrin and soluble transferrin receptor and the transferrin saturation, are routinely determined instead. As previous research has shown that also the isotopic composition of Fe in blood and tissues is dependent on the metabolism, the present study assessed whether Fe isotopic composition in whole blood provides information as to an individual's iron status. Fe isotopic analysis of whole blood samples from a reference population (healthy volunteers) was carried out using multi-collector ICP-mass spectrometry (after chromatographic target element isolation) and the results obtained were investigated by statistical means as to their potential relation with the iron status parameters conventionally used in medicine. A low δ(56)Fe value was demonstrated to coincide with high iron status and a high δ(56)Fe value with low iron status, thus reflecting the response of the body to this iron status in terms of iron uptake, distribution between blood and stores and mobilization of storage iron. In a second phase, the iron isotopic composition in blood from patients treated for hemochromatosis type I and from patients with anemia of chronic disease (ACD) was determined. The results for hemochromatosis patients plotted with the values of low iron status, while those for ACD patients plotted with the values of high iron status. By taking a closer look at the aberrant iron metabolism that comes with these diseases, it can be seen that the patient samples confirm the conclusions drawn for the reference population. Patients with hemochromatosis type I have a strongly upregulated iron uptake, like healthy individuals with low iron status. The metabolism of patients suffering from ACD tries to remove iron from the circulation by downregulating the iron uptake

  10. Electrochemically controlled iron isotope fractionation

    NASA Astrophysics Data System (ADS)

    Black, Jay R.; Young, Edward D.; Kavner, Abby

    2010-02-01

    Variations in the stable isotope abundances of transition metals have been observed in the geologic record and trying to understand and reconstruct the physical/environmental conditions that produced these signatures is an area of active research. It is clear that changes in oxidation state lead to large fractionations of the stable isotopes of many transition metals such as iron, suggesting that transition metal stable isotope signatures could be used as a paleo-redox proxy. However, the factors contributing to these observed stable isotope variations are poorly understood. Here we investigate how the kinetics of iron redox electrochemistry generates isotope fractionation. Through a combination of electrodeposition experiments and modeling of electrochemical processes including mass-transport, we show that electron transfer reactions are the cause of a large isotope separation, while mass transport-limited supply of reactant to the electrode attenuates the observed isotopic fractionation. Furthermore, the stable isotope composition of electroplated transition metals can be tuned in the laboratory by controlling parameters such as solution chemistry, reaction overpotential, and solution convection. These methods are potentially useful for generating isotopically-marked metal surfaces for tracking and forensic purposes. In addition, our studies will help interpret stable isotope data in terms of identifying underlying electron transfer processes in laboratory and natural samples.

  11. Corrosion performance of iron aluminides

    SciTech Connect

    Natesan, K.

    1993-03-01

    Iron aluminides are being developed for use as structural materials and/or cladding alloys in fossil energy systems. Extensive development has been in progress on Fe[sub 3]Al-based alloys to improve the engineering ductility of these alloys. This paper describes results from the ongoing program to evaluate the corrosion performance of these alloys. The experimental program at Argonne National Laboratory involvesthermogravimetric analyses of alloys exposed to environments that simulate coal gasification and fluidized-bed combustion. Experiments were conducted at 650--1000[degrees]C in simulated oxygen/sulfur gas mixtures. In addition, oxidation/sulfidation behavior of several alumina-forming Fe-Al and Fe-Cr-Ni-Al alloys was determined for comparison with the corrosion rates obtained on iron aluminides. Other aspects of the program are corrosion evaluation of the aluminides in the presence of HC1-containing gases and in the presence of slag from a slogging gasifier. Results are used to establish threshold Al levels in the alloys for development of protective alumina scales. Thermal cycling tests are used to examine the spalling resistance of the scales.

  12. Preliminary Iron Distribution on Vesta

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Mittlefehldt, David W.

    2013-01-01

    The distribution of iron on the surface of the asteroid Vesta was investigated using Dawn's Gamma Ray and Neutron Detector (GRaND) [1,2]. Iron varies predictably with rock type for the howardite, eucrite, and diogenite (HED) meteorites, thought to be representative of Vesta. The abundance of Fe in howardites ranges from about 12 to 15 wt.%. Basaltic eucrites have the highest abundance, whereas, lower crustal and upper mantle materials (cumulate eucrites and diogenites) have the lowest, and howardites are intermediate [3]. We have completed a mapping study of 7.6 MeV gamma rays produced by neutron capture by Fe as measured by the bismuth germanate (BGO) detector of GRaND [1]. The procedures to determine Fe counting rates are presented in detail here, along with a preliminary distribution map, constituting the necessary initial step to quantification of Fe abundances. We find that the global distribution of Fe counting rates is generally consistent with independent mineralogical and compositional inferences obtained by other instruments on Dawn such as measurements of pyroxene absorption bands by the Visual and Infrared Spectrometer (VIR) [4] and Framing Camera (FC) [5] and neutron absorption measurements by GRaND [6].

  13. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  14. Integrated Translatomics with Proteomics to Identify Novel Iron–Transporting Proteins in Streptococcus pneumoniae

    PubMed Central

    Yang, Xiao-Yan; He, Ke; Du, Gaofei; Wu, Xiaohui; Yu, Guangchuang; Pan, Yunlong; Zhang, Gong; Sun, Xuesong; He, Qing-Yu

    2016-01-01

    Streptococcus pneumoniae (S.pneumoniae) is a major human pathogen causing morbidity and mortality worldwide. Efficiently acquiring iron from the environment is critical for S. pneumoniae to sustain growth and cause infection. There are only three known iron-uptake systems in Streptococcal species responsible for iron acquisition from the host, including ABC transporters PiaABC, PiuABC, and PitABC. Besides, no other iron-transporting system has been suggested. In this work, we employed our newly established translating mRNA analysis integrated with proteomics to evaluate the possible existence of novel iron transporters in the bacterium. We simultaneously deleted the iron-binding protein genes of the three iron-uptake systems to construct a piaA/piuA/pitA triple mutant (Tri-Mut) of S. pneumoniae D39, in which genes and proteins related to iron transport should be regulated in response to the deletion. With ribosome associated mRNA sequencing-based translatomics focusing on translating mRNA and iTRAQ quantitative proteomics based on the covalent labeling of peptides with tags of varying mass, we indeed observed a large number of genes and proteins representing various coordinated biological pathways with significantly altered expression levels in the Tri-Mut mutant. Highlighted in this observation is the identification of several new potential iron-uptake ABC transporters participating in iron metabolism of Streptococcus. In particular, putative protein SPD_1609 in operon 804 was verified to be a novel iron-binding protein with similar function to PitA in S. pneumoniae. These data derived from the integrative translatomics and proteomics analyses provided rich information and insightful clues for further investigations on iron-transporting mechanism in bacteria and the interplay between Streptococcal iron availability and the biological metabolic pathways. PMID:26870030

  15. The Corrosion and Preservation of Iron Antiques.

    ERIC Educational Resources Information Center

    Walker, Robert

    1982-01-01

    Discusses general corrosion reactions (iron to rust), including corrosion of iron, sulfur dioxide, chlorides, immersed corrosion, and underground corrosion. Also discusses corrosion inhibition, including corrosion inhibitors (anodic, cathodic, mixed, organic); safe/dangerous inhibitors; and corrosion/inhibition in concrete/marble, showcases/boxes,…

  16. Dechlorination of TCE with palladized iron

    DOEpatents

    Fernando, Quintus; Muftikian, Rosy; Korte, Nic

    1997-01-01

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from various effluents or contaminated soil containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products.

  17. Formation and Reactivity of Biogenic Iron Microminerals

    SciTech Connect

    Beveridge, Terrance J.; Ferris, F. Grant

    2001-08-15

    The overall purpose of the project was to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addressed how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  18. Iron decreases biological effects of ozone exposure

    EPA Science Inventory

    CONTEXT: Ozone (0(3)) exposure is associated with a disruption of iron homeostasis and increased availability of this metal which potentially contributes to an oxidative stress and biologicaleffects. OBJECTIVE: We tested the postulate that increased concentrations of iron in c...

  19. CONTROLLING ODOROUS EMISSIONS FROM IRON FOUNDRIES

    EPA Science Inventory

    The report discusses the control of odorous emissions from iron foundries. he main process sources of odors in iron foundries are mold and core making, casting, and sand shakeout. he odors are usually caused by chemicals, which may be present as binders and other additives to the...

  20. Capturing phosphates with iron enhanced sand filtration.

    PubMed

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  1. Iron homeostasis in the Rhodobacter genus

    PubMed Central

    Zappa, Sébastien; Bauer, Carl E.

    2013-01-01

    Metals are utilized for a variety of critical cellular functions and are essential for survival. However cells are faced with the conundrum of needing metals coupled with e fact that some metals, iron in particular are toxic if present in excess. Maintaining metal homeostasis is therefore of critical importance to cells. In this review we have systematically analyzed sequenced genomes of three members of the Rhodobacter genus, R. capsulatus SB1003, R. sphaeroides 2.4.1 and R. ferroxidans SW2 to determine how these species undertake iron homeostasis. We focused our analysis on elemental ferrous and ferric iron uptake genes as well as genes involved in the utilization of iron from heme. We also discuss how Rhodobacter species manage iron toxicity through export and sequestration of iron. Finally we discuss the various putative strategies set up by these Rhodobacter species to regulate iron homeostasis and the potential novel means of regulation. Overall, this genomic analysis highlights surprisingly diverse features involved in iron homeostasis in the Rhodobacter genus. PMID:24382933

  2. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  3. Obesity promotes alterations in iron recycling.

    PubMed

    Citelli, Marta; Fonte-Faria, Thaís; Nascimento-Silva, Vany; Renovato-Martins, Mariana; Silva, Raphael; Luna, Aderval Severino; Silva, Simone Vargas da; Barja-Fidalgo, Christina

    2015-01-01

    Hepcidin is a key hormone that induces the degradation of ferroportin (FPN), a protein that exports iron from reticuloendothelial macrophages and enterocytes. The aim of the present study was to experimentally evaluate if the obesity induced by a high-fat diet (HFD) modifies the expression of FPN in macrophages and enterocytes, thus altering the iron bioavailability. In order to directly examine changes associated with iron metabolism in vivo, C57BL/6J mice were fed either a control or a HFD. Serum leptin levels were evaluated. The hepcidin, divalent metal transporter-1 (DMT1), FPN and ferritin genes were analyzed by real-time polymerase chain reaction. The amount of iron present in both the liver and spleen was determined by flame atomic absorption spectrometry. Ferroportin localization within reticuloendothelial macrophages was observed by immunofluorescence microscopy. Obese animals were found to exhibit increased hepcidin gene expression, while iron accumulated in the spleen and liver. They also exhibited changes in the sublocation of splenic cellular FPN and a reduction in the FPN expression in the liver and the spleen, while no changes were observed in enterocytes. Possible explanations for the increased hepcidin expression observed in HFD animals may include: increased leptin levels, the liver iron accumulation or endoplasmic reticulum (ER) stress. Together, the results indicated that obesity promotes changes in iron bioavailability, since it altered the iron recycling function.

  4. Tannin biosynthesis of iron oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Herrera-Becerra, R.; Rius, J. L.; Zorrilla, C.

    2010-08-01

    In this work, iron oxide nanoparticles synthesized with gallic acid and tannic acid are characterized using High-Resolution Transmission Electron Microscopy (HRTEM). Its size, form, and structure are compared with nanoparticles obtained previously using alfalfa biomass in order to find a simpler, consistent, and environmentally friendly method in the production of iron oxide nanoparticles.

  5. Is There an Ironic Tone of Voice?

    ERIC Educational Resources Information Center

    Bryant, Gregory A.; Fox Tree, Jean E.

    2005-01-01

    Research on nonverbal vocal cues and verbal irony has often relied on the concept of an "ironic tone of voice". Here we provide acoustic analysis and experimental evidence that this notion is oversimplified and misguided. Acoustic analyses of spontaneous ironic speech extracted from talk radio shows, both ambiguous and unambiguous in written form,…

  6. Obesity promotes alterations in iron recycling.

    PubMed

    Citelli, Marta; Fonte-Faria, Thaís; Nascimento-Silva, Vany; Renovato-Martins, Mariana; Silva, Raphael; Luna, Aderval Severino; Silva, Simone Vargas da; Barja-Fidalgo, Christina

    2015-01-01

    Hepcidin is a key hormone that induces the degradation of ferroportin (FPN), a protein that exports iron from reticuloendothelial macrophages and enterocytes. The aim of the present study was to experimentally evaluate if the obesity induced by a high-fat diet (HFD) modifies the expression of FPN in macrophages and enterocytes, thus altering the iron bioavailability. In order to directly examine changes associated with iron metabolism in vivo, C57BL/6J mice were fed either a control or a HFD. Serum leptin levels were evaluated. The hepcidin, divalent metal transporter-1 (DMT1), FPN and ferritin genes were analyzed by real-time polymerase chain reaction. The amount of iron present in both the liver and spleen was determined by flame atomic absorption spectrometry. Ferroportin localization within reticuloendothelial macrophages was observed by immunofluorescence microscopy. Obese animals were found to exhibit increased hepcidin gene expression, while iron accumulated in the spleen and liver. They also exhibited changes in the sublocation of splenic cellular FPN and a reduction in the FPN expression in the liver and the spleen, while no changes were observed in enterocytes. Possible explanations for the increased hepcidin expression observed in HFD animals may include: increased leptin levels, the liver iron accumulation or endoplasmic reticulum (ER) stress. Together, the results indicated that obesity promotes changes in iron bioavailability, since it altered the iron recycling function. PMID:25569627

  7. Processing and applications of iron aluminides

    SciTech Connect

    Sikka, V.K.

    1994-09-01

    Iron aluminides are well known for their resistance to high- temperature sulfidizing and oxidizing environments. In order to take advantage of their excellent corrosion resistance, several methods for their processing have been identified. Issues with melting and processing are discussed detail. Effects of grain size and melting practice on low-temperature ductility are also presented. Many applications for iron aluminides are described.

  8. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and...

  9. Formation and Reactivity of Biogenic Iron Microminerals

    SciTech Connect

    Beveridge, Terrance J.; Glasauer, Susan; Korenevsky, Anton; Ferris, F. Grant

    2000-08-08

    The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  10. Removal of metallic iron on oxide slags

    SciTech Connect

    Shannon, G.N.; Fruehan, R.J.; Sridhar, S.

    2009-10-15

    It is possible, in some cases, for ground coal particles to react with gasifier gas during combustion, allowing the ash material in the coal to form phases besides the expected slag phase. One of these phases is metallic iron, because some gasifiers are designed to operate under a reducing atmosphere (pO{sub 2}) of approximately 10{sup -4} atm). Metallic iron can become entrained in the gas stream and deposit on, and foul, downstream equipment. To improve the understanding of the reaction between different metallic iron particles and gas, which eventually oxidizes them, and the slag that the resulting oxide dissolves in, the kinetics of iron reaction on slag were predicted using gas-phase mass-transfer limitations for the reaction and were compared with diffusion in the slag; the reaction itself was observed under confocal scanning laser microscopy. The expected rates for iron droplet removal are provided based on the size and effective partial pressure of oxygen, and it is found that decarburization occurs before iron reaction, leading to an extra 30- to 100-second delay for carbon-saturated particles vs pure iron particles. A pure metallic iron particle of 0.5 mg should be removed in about 220 seconds at 1400{sup o}C and in 160 seconds at 1600{sup o}C.

  11. Antimalarial properties of orally active iron chelators.

    PubMed

    Heppner, D G; Hallaway, P E; Kontoghiorghes, G J; Eaton, J W

    1988-07-01

    The appearance of widespread multiple drug resistance in human malaria has intensified the search for new antimalarial compounds. Metal chelators, especially those with high affinity for iron, represent one presently unexploited class of antimalarials. Unfortunately the use of previously identified chelators as antimalarials has been precluded by their toxicity and, in the case of desferrioxamine, the necessity for parenteral administration. The investigators now report that a new class of orally active iron chelators, namely the derivatives of alpha-ketohydroxypyridines (KHPs), are potent antimalarials against cultured Plasmodium falciparum. The KHPs evidently exert this effect by sequestering iron because a preformed chelator:iron complex has no antimalarial action. The pool(s) of iron being sequestered by the chelators have not been identified but may not include serum transferrin. Preincubation of human serum with KHPs followed by removal of the drug results in the removal of greater than 97% of total serum iron. Nonetheless, this serum effectively supports the growth of P falciparum cultures. Therefore the KHPs may exert antimalarial effect through chelation of erythrocytic rather than serum iron pool(s). The investigators conclude that these powerful, orally active iron chelators may form the basis of a new class of antimalarial drugs. PMID:3291984

  12. Bacterial ferrous iron transport: the Feo system.

    PubMed

    Lau, Cheryl K Y; Krewulak, Karla D; Vogel, Hans J

    2016-03-01

    To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are essential. Several bacterial ferrous iron transport systems have been described; however, only the Feo system appears to be widely distributed and is exclusively dedicated to the transport of iron. In recent years, many studies have explored the role of the FeoB and FeoA proteins in ferrous iron transport and their contribution toward bacterial virulence. The three-dimensional structures for the Feo proteins have recently been determined and provide insight into the molecular details of the transport system. A highly select group of bacteria also express the FeoC protein from the same operon. This review will provide a comprehensive look at the structural and functional aspects of the Feo system. In addition, bioinformatics analyses of the feo operon and the Feo proteins have been performed to complement our understanding of this ubiquitous bacterial uptake system, providing a new outlook for future studies.

  13. Voice modulations in German ironic speech.

    PubMed

    Scharrer, Lisa; Christmann, Ursula; Knoll, Monja

    2011-12-01

    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' that may possibly act as irony cues by comparing acoustic measures of ironic and literal speech. For this purpose, samples of scripted ironic and literal target utterances produced by 14 female speakers were recorded and acoustically analyzed. Results showed that in contrast to literal remarks, ironic criticism was characterized by a decreased mean fundamental frequency (F0), raised energy levels and increased vowel duration, whereas F0-contours differed only marginally between both speech types. Furthermore, we found ironic speech to be characterized by vowel hyperarticulation,an acoustic feature which has so far not been considered as a possible irony cue. Contrary to our expectations, voice modulations in ironic speech were applied independently from the availability of additional, visual irony cues.The results are discussed in light of previous findings on acoustic features of irony yielded for other languages.

  14. Roman mystery iron blades from Serbia

    SciTech Connect

    Balos, Sebastian; Benscoter, Arlan; Pense, Alan

    2009-04-15

    A First to Forth Century Roman spear blade from Serbia was found to have an unusual microstructure inconsistent with typical Roman Period iron. An analysis of the blade undertaken at Lehigh University in the US and at the Faculty of Technical Sciences in Novi Sad, Serbia established that it was metallic in appearance, magnetic and had an external layer of red rust. But as metallographically polished, it appeared to contain multiple internal phases and internal cracking. Even after aggressive etching, no typical low carbon microstructure was developed. Scanning electron microscopy, classical and energy dispersive X-ray analysis indicated that the specimen was essentially iron, although its microhardness was too high for typical Roman iron. It was then dubbed 'Mystery Iron.' Analysis of all the data led to the proposal that it was essentially a Roman iron 'fossil' in which the iron had been converted to high temperature iron oxide while retaining the form of the blade, conversion probably occurring in a fire. Subsequent X-ray diffraction analysis confirmed that the blade consisted of FeO and Fe{sub 3}O{sub 4} and the mystery of the iron fossil was at least partially solved. A hypothesis is proposed regarding a potential cause for the fire.

  15. Iron Deficiency in Adolescents and Young Adults.

    ERIC Educational Resources Information Center

    Risser, William L.; Risser, Jan M. H.

    1990-01-01

    Reviews the prevalence, natural history, causes, impact on performance, diagnosis, and treatment of iron deficiency in adolescent and young adult athletes. All athletes should be screened and treated. The best diagnosis involves determining serum ferritin and hemoglobin levels. Treatment requires therapeutic doses of oral ferrous iron for several…

  16. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron (III) oxide (CAS Reg. No. 1309-37-1, red-brown to black trigonal crystals). (b) In accordance with § 186.1(b)(1), the ingredient...

  17. Duodenal Amyloidosis Masquerading as Iron Deficiency Anemia

    PubMed Central

    Hurairah, Abu

    2016-01-01

    The present study is a unique illustration of duodenal amyloidosis initially manifesting with iron deficiency anemia. It underscores the importance of clinical suspicion of amyloidosis while performing upper gastrointestinal endoscopy with a biopsy to establish the definite diagnosis in patients with unexplained iron deficiency anemia. PMID:27625911

  18. The role of iron in pulmonary pathology.

    PubMed

    Khiroya, Heena; Turner, Alice M

    2015-01-01

    Respiratory disease accounts for a large proportion of emergency admissions to hospital and diseaseassociated mortality. Genetic association studies demonstrate a link between iron metabolism and pulmonary disease phenotypes. IREB2 is a gene that produces iron regulatory protein 2 (IRP2), which has a key role in iron homeostasis. This review addresses pathways involved in iron metabolism, particularly focusing on the role of IREB2. In addition to this, environmental factors also influence phenotypic variation in respiratory disease, for example inhaled iron from cigarette smoke is deposited in the lung and causes tissue damage by altering iron homeostasis. The effects of cigarette smoke are detailed in this article, particularly in relation to lung conditions that favour the upper lobes, such as emphysema and lung cancer. Clinical applications of iron homeostasis are also discussed in this review, especially looking at the pathophysiology of chronic obstructive pulmonary disease, lung cancer, pulmonary infections and acute respiratory distress syndrome. Promising new treatments involving iron are also covered. PMID:26629341

  19. IRON COATED URANIUM AND ITS PRODUCTION

    DOEpatents

    Gray, A.G.

    1960-03-15

    A method of applying a protective coating to a metallic uranium article is given. The method comprises etching the surface of the article with an etchant solution containlng chloride ions, such as a solution of phosphoric acid and hydrochloric acid, cleaning the etched surface, electroplating iron thereon from a ferrous ammonium sulfate electroplating bath, and soldering an aluminum sheath to the resultant iron layer.

  20. Production of iron from metallurgical waste

    DOEpatents

    Hendrickson, David W; Iwasaki, Iwao

    2013-09-17

    A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO.sub.2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.