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Sample records for magnitogorsk integrated iron

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

    NASA Astrophysics Data System (ADS)

    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.

  2. 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

  3. 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 ...

  4. Iron

    MedlinePLUS

    ... are available? Iron is available in many multivitamin-mineral supplements and in supplements that contain only iron. Iron in supplements is often in the form of ferrous sulfate, ferrous gluconate, ferric citrate, or ferric sulfate. Dietary ...

  5. 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

  6. 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.

  7. Iron

    MedlinePLUS

    ... avoid taking it with foods containing dairy products, coffee, tea, or cereals. There are many forms of ... Coffee and teaTaking iron supplements with coffee or tea can reduce the amount of iron the body ...

  8. FUGITIVE EMISSIONS FROM INTEGRATED IRON AND STEEL PLANTS

    EPA Science Inventory

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

  9. IRON

    EPA Science Inventory

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

  10. Iron

    MedlinePLUS

    ... Guidelines for Americans and the U.S. Department of Agriculture's food guidance system, ChooseMyPlate . Where can I find ... on food sources of iron: U.S. Department of Agriculture's (USDA) National Nutrient Database Nutrient List for Iron ( ...

  11. Iron

    MedlinePLUS

    ... also used for improving athletic performance and treating attention deficit-hyperactivity disorder (ADHD) and canker sores. Some people also use ... body when taken by women who are pregnant.Attention deficit-hyperactivity disorder (ADHD). Developing research shows that taking iron sulfate ( ...

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

    EPA Science Inventory

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

  13. Integration of Quercetin-Iron Complexes into Phosphatidylcholine or Phosphatidylethanolamine Liposomes.

    PubMed

    Kim, Yuri A; Tarahovsky, Yury S; Yagolnik, Elena A; Kuznetsova, Svetlana M; Muzafarov, Eugeny N

    2015-08-01

    It is well known that flavonoids can chelate transition metals. Flavonoid-metal complexes exhibit a high antioxidative and therapeutic potential. However, the complexes are frequently hydrophobic ones and low soluble in water, which restricts their medical applications. Integration of these complexes into liposomes may increase their bioavailability and therapeutic effect. Here, we studied the interaction of quercetin-iron complexes with dimyristoylphosphatidylcholine (DMPC) or palmitoyl-oleoyl phosphatidylethanolamine (POPE) multilamellar liposomes. Differential scanning calorimetry (DSC) and freeze-fracture electron microscopy revealed that quercetin-iron complexes did not interact with liposomes. Quercetin however could penetrate lipid bilayers, when added to liposomes at a temperature above lipid melting. Iron cations added later penetrated into the lipid bilayers and produced complexes with quercetin in the liposomes. The quercetin-iron entry in POPE liposomes was improved when the suspension was heated above the temperature of the bilayer-hexagonal HII phase transition of the lipid. The approach proposed facilitates the integration of quercetin-iron complexes into liposomes and may promote their use in medicine. PMID:26047928

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

    PubMed Central

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

    2012-01-01

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

  15. Laser sintering of separated and uniformly distributed multiwall carbon nanotubes integrated iron nanocomposites

    NASA Astrophysics Data System (ADS)

    Lin, Dong; Richard Liu, C.; Cheng, Gary J.

    2014-03-01

    Uniform distribution of carbon nanotubes (CNTs) in metal matrix during additive manufacturing of nanocomposites is always a challenge since the CNTs tend to aggregate in the molten pool. In this study, Multiwall carbon nanotubes (MWNTs) were separated and distributed uniformly into iron matrix by laser sintering process. MWNTs and iron powders were mixed together by magnetic stir, coated on steel 4140 surface, followed by laser sintering. Due to the fast heating and cooling rate, the CNTs are evenly distributed in the metal matrix. The temperature field was calculated by multiphysics simulation considering size effects, including size dependent melting temperature, thermal conductivity, and heat capacity. The SEM, TEM, and XRD were used to understand the laser sintering of CNT integrated nanocomposites. The results proved the feasibility of this technique to synthesize MWNTS integrated metal matrix nanocomposites.

  16. Novel molecular platform integrated iron chelation therapy for 1H-MRI detection of ?-galactosidase activity.

    PubMed

    Li, Xiaojin; Zhang, Zhongwei; Yu, Zijun; Magnusson, Jennifer; Yu, Jian-Xin

    2013-04-01

    Targeting the increased Fe(3+) content in tumors, we propose a novel molecular platform integrated cancer iron chelation therapy for (1)H-magnetic resonance imaging (MRI) detection of ?-galactosidase (?-gal) activity. Following this idea, we have designed, synthesized, and characterized a series of ?-d-galactosides conjugated with various chelators and demonstrated the feasibility of this concept for assessing ?-gal activity in solution by (1)H-MRI T1 and T2 relaxation mapping. PMID:23391334

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

    PubMed

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

    2008-09-15

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

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

    E-print Network

    Miao, Ren

    2012-02-14

    of the cellular iron probably precipitates in mitochondria as Fe(III) nanoparticles. The results provide novel insights into iron trafficking and possible signal communications between organelles within cells. v DEDICATION I dedicate this work to my.................................................................................................................. v ACKNOWLEDGEMENTS .......................................................................................... vi TABLE OF CONTENTS ............................................................................................. vii LIST OF FIGURES...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  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. 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...

  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. 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. ...

  5. 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.

  6. 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.

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

    PubMed

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

    2010-12-01

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

  8. 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.

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

    PubMed Central

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

    2014-01-01

    Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat. PMID:24600464

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

    PubMed

    Goto, Taichi; Onba?l?, 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. PMID:23263087

  11. Regulation of cellular iron metabolism

    PubMed Central

    Wang, Jian; Pantopoulos, Kostas

    2011-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  13. 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.

  14. Iron overdose

    MedlinePLUS

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

  15. 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 measures are available over time, which allows an estimation of technological change over a decade-long historical period. In particular, the report will describe new treatment of technological change in energy-climate modeling for this industry sector, i.e., assessing the changes in costs and energy-savings potentials via comparing 1994 and 2002 conservation supply curves. In this study, we compared the same set of mitigation measures for both 1994 and 2002 -- no additional mitigation measure for year 2002 was included due to unavailability of such data. Therefore, the estimated potentials in total energy savings and carbon reduction would most likely be more conservative for year 2002 in this study. Based upon the cost curves, the rate of change in the savings potential at a given cost can be evaluated and be used to estimate future rates of change that can be the input for energy-climate models. Through characterizing energy-efficiency technology costs and improvement potentials, we have developed and presented energy cost curves for energy efficiency measures applicable to the U.S. iron and steel industry for the years 1994 and 2002. The cost curves can change significantly under various scenarios: the baseline year, discount rate, energy intensity, production, industry structure (e.g., integrated versus secondary steel making and number of plants), efficiency (or mitigation) measures, share of iron and steel production to which the individual measures can be applied, and inclusion of other non-energy benefits. Inclusion of other non-energy benefits from implementing mitigation measures can reduce the costs of conserved energy significantly. In addition, costs of conserved energy (CCE) for individual mitigation measures increase with the increases in discount rates, resulting in a general increase in total cost of mitigation measures for implementation and operation with a higher discount rate. In 1994, integrated steel mills in the U.S. produced 55.

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

    PubMed Central

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

    2013-01-01

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

  17. Integrated biomarker assessment of the effects of tailing discharges from an iron ore mine using blue mussels (Mytilus spp.).

    PubMed

    Brooks, Steven J; Harman, Christopher; Hultman, Maria T; Berge, John Arthur

    2015-08-15

    The blue mussel (Mytilus spp.) has been used to assess the potential biological effects of the discharge effluent from the Sydvaranger mine, which releases its tailings into Bøk fjord at Kirkenes in the north of Norway. Metal bioaccumulation and a suite of biomarkers were measured in mussels positioned for 6 weeks at varying distances from the discharge outlet. The biomarkers used included: stress on stress (SS); condition index (CI); cellular energy allocation (CEA); micronuclei formation (MN); lysosomal membrane stability (LMS), basophilic cell volume (VvBAS); and neutral lipid (NL) accumulation. The individual biomarkers were integrated using the integrated biological response (IBR/n) index. The accumulation of Fe was significantly higher in mussels located closer to the discharge outlet, indicating that these mussels had been exposed to the suspended mine effluent. The IBR/n results were in good agreement with the location of the mussels in relation to the distance from the discharge outlet and expected exposure to the mine effluent. Several biomarkers showed responses resulting in higher IBR/n values of analysed mussels within a 3 km distance from the tailing discharge. PMID:25889549

  18. Iron deficiency anemia

    MedlinePLUS

    Treatment may include taking iron supplements and eating iron-rich foods . Iron supplements (most often ferrous sulfate) are needed ... the body's iron stores in the bone marrow. Iron-rich foods include: Chicken and turkey Dried lentils, peas, and ...

  19. Iron chelators and iron toxicity.

    PubMed

    Brittenham, Gary M

    2003-06-01

    Iron chelation may offer new approaches to the treatment and prevention of alcoholic liver disease. With chronic excess, either iron or alcohol alone may individually injure the liver and other organs. In combination, each exaggerates the adverse effects of the other. In alcoholic liver disease, both iron and alcohol contribute to the production of hepatic fibrosis through their effects on damaged hepatocytes, hepatic macrophages, hepatic stellate cells, and the extracellular matrix. The pivotal role of iron in these processes suggests that chelating iron may offer a new approach to arresting or ameliorating liver injury. For the past four decades, deferoxamine B mesylate has been the only iron-chelating agent generally available for clinical use. Clinical experience with deferoxamine has demonstrated the safety and effectiveness of iron chelation for the prevention and treatment of iron overload. Determined efforts to develop alternative agents have at last resulted in the development of a variety of candidate iron chelators that are now in or near clinical trial, including (a) the hexadentate phenolic aminocarboxylate HBED [N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid], (b) the tridentate desferrithiocin derivative 4'-OH-dadmDFT [4'-hydroxy-(S)-desazadesmethyl-desferrithiocin; (S)-4,5-dihydro-2-(2,4-dihydroxyphenyl)-4-thiazolecarboxylic acid], (c) the tridentate triazole ICL670A [CGP72 670A; 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid], and (d) the bidentate hydroxypyridin-4-one deferiprone [L1, CP20; 1,2-dimethyl-3-hydroxypyridin-4-one]. These agents may provide new pharmacological means of averting or ameliorating liver damage in alcoholic liver disease by binding, inactivating, and eliminating the reactive forms of iron that contribute to oxidative injury of cellular components, are involved in signal transduction, or both. PMID:12957300

  20. 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. PMID:22470372

  1. Runner's anemia and iron deficiency.

    PubMed

    Hunding, A; Jordal, R; Paulev, P E

    1981-01-01

    Systemic iron deficiency was found in 63 (56%) of 113 joggers and competition runners (33 women and 80 men). Thirteen women and ten men had latent anemia. A majority of the women were fertile with iron loss from menstruation; the men were runners training long distances. The average transferrin iron-binding capacity was 80 mu mol/l serum in the women and 77 (iron-binding groups) in the men. The haptoglobin and iron concentrations in serum were remarkably low (most often below 10 and 20 mu mol/l, respectively). Three of the long-distance runners ran 25 km daily. They returned with so much free hemoglobin in their plasma that an accompanying iron loss (integrated over months), if not balanced by diet, would lead to iron deficiency and anemia. Oral iron therapy (200 mg ferrous sulphate per day) normalized the hemoglobin concentration and improved the transferrin saturation fraction in 61 persons. The competition runners reported personal records. PMID:7234508

  2. Iron contamination in silicon technology

    NASA Astrophysics Data System (ADS)

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

    This article continues the review of fundamental physical properties of iron and its complexes in silicon (Appl. Phys. A 69, 13 (1999)), and is focused on ongoing applied research of iron in silicon technology. The first section of this article presents an analysis of the effect of iron on devices, including integrated circuits, power devices, and solar cells. Then, sources of unintentional iron contamination and reaction paths of iron during device manufacturing are discussed. Experimental techniques to measure trace contamination levels of iron in silicon, such as minority carrier lifetime techniques (SPV, ?-PCD, and ELYMAT), deep-level transient spectroscopy (DLTS), total X-ray fluorescence (TXRF) and vapor-phase decomposition TXRF (VPD-TXRF), atomic absorption spectroscopy (AAS), mass spectrometry and its modifications (SIMS, SNMS, ICP-MS), and neutron activation analysis (NAA) are reviewed in the second section of the article. Prospective analytical tools, such as heavy-ion backscattering spectroscopy (HIBS) and synchrotron-based X-ray microprobe techniques (XPS, XANES, XRF) are briefly discussed. The third section includes a discussion of the present achievements and challenges of the electrochemistry and physics of cleaning of silicon wafers, with an emphasis on removal of iron contamination from the wafers. Finally, the techniques for gettering of iron are presented.

  3. Iron control in zinc pressure leach processes

    NASA Astrophysics Data System (ADS)

    Buban, K. R.; Collins, M. J.; Masters, I. M.

    1999-12-01

    The occurrence of zinc in sulfide ore deposits is generally accompanied by various iron minerals. Hence, even the most efficient concentrators generally produce a zinc concentrate with significant iron content. The efficient recovery of zinc metal from zinc concentrates requires the rejection of iron residue in a form that minimizes the zinc entrainment. Careful control of the iron precipitation step is important, so that the iron residue produced is amenable to efficient liquid-solid separation in order to obtain high zinc recoveries. In hydrometallurgical zinc processes, the coprecipitation of minor impurities along with iron precipitation is also important in producing zinc-sulfate solution from which high-purity zinc cathode can be electrowon. The integration of Dynatec’s zinc pressure leach process with existing roast-leach-electrowin plants employing various methods of iron rejection is briefly described in this article, along with the application of two-stage pressure leaching in stand-alone processes.

  4. Iron Chelation Therapy

    MedlinePLUS

    ... iron overload. What actually happens to cause iron overload? With each red blood cell transfusion, your body ... is deposited. What are the symptoms of iron overload? Early on, iron overload can cause no symptoms, ...

  5. 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.

  6. Integration

    ERIC Educational Resources Information Center

    Kalyn, Brenda

    2006-01-01

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

  7. 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…

  8. [Iron dysregulation and anemias].

    PubMed

    Ikuta, Katsuya

    2015-10-01

    Most iron in the body is utilized as a component of hemoglobin that delivers oxygen to the entire body. Under normal conditions, the iron balance is tightly regulated. However, iron dysregulation does occasionally occur; total iron content reductions cause iron deficiency anemia and overexpression of the iron regulatory peptide hepcidin disturbs iron utilization resulting in anemia of chronic disease. Conversely, the presence of anemia may ultimately lead to iron overload; for example, thalassemia, a common hereditary anemia worldwide, often requires transfusion, but long-term transfusions cause iron accumulation that leads to organ damage and other poor outcomes. On the other hand, there is a possibility that iron overload itself can cause anemia; iron chelation therapy for the post-transfusion iron overload observed in myelodysplastic syndrome or aplastic anemia improves dependency on transfusions in some cases. These observations reflect the extremely close relationship between anemias and iron metabolism. PMID:26458428

  9. MNN5 Encodes an Iron-Regulated ?-1,2-Mannosyltransferase Important for Protein Glycosylation, Cell Wall Integrity, Morphogenesis, and Virulence in Candida albicans

    PubMed Central

    Bai, Chen; Xu, Xiao-Li; Chan, Fong-Yee; Lee, Raymond Teck Ho; Wang, Yue

    2006-01-01

    The cell walls of microbial pathogens mediate physical interactions with host cells and hence play a key role in infection. Mannosyltransferases have been shown to determine the cell wall properties and virulence of the pathogenic fungus Candida albicans. We previously identified a C. albicans ?-1,2-mannosyltransferase, Mnn5, for its novel ability to enhance iron usage in Saccharomyces cerevisiae. Here we have studied the enzymatic properties of purified Mnn5 and characterized its function in its natural host. Mnn5 catalyzes the transfer of mannose to both ?-1,2- and ?-1,6-mannobiose, and this activity requires Mn2+ as a cofactor and is regulated by the Fe2+ concentration. An mnn5? mutant showed a lowered ability to extend O-linked, and possibly also N-linked, mannans, hypersensitivity to cell wall-damaging agents, and a reduction of cell wall mannosylphosphate content, phenotypes typical of many fungal mannosyltransferase mutants. The mnn5? mutant also exhibited some unique defects, such as impaired hyphal growth on solid media and attenuated virulence in mice. An unanticipated phenotype was the mnn5? mutant's resistance to killing by the iron-chelating protein lactoferrin, rendering it the first protein found that mediates lactoferrin killing of C. albicans. In summary, MNN5 deletion impairs a wide range of cellular events, most likely due to its broad substrate specificity. Of particular interest was the observed role of iron in regulating the enzymatic activity, suggesting an underlying relationship between Mnn5 activity and cellular iron homeostasis. PMID:16467465

  10. Iron and Prochlorococcus/

    E-print Network

    Thompson, Anne Williford

    2009-01-01

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

  11. Iron Sucrose Injection

    MedlinePLUS

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called ...

  12. Iron metabolism and toxicity

    SciTech Connect

    Papanikolaou, G.; Pantopoulos, K. . E-mail: kostas.pantopoulos@mcgill.ca

    2005-01-15

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

  13. Iron and Your Child

    MedlinePLUS

    ... an Everyday Diet Ever wonder why so many cereals and infant formulas are fortified with iron? Iron ... 4-6 months of age, when iron-fortified cereal is usually introduced (although breastfeeding moms should continue ...

  14. Saugus Iron Works Forge

    USGS Multimedia Gallery

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

  15. 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.

  16. Genetics Home Reference: Iron-refractory iron deficiency anemia

    MedlinePLUS

    ... iron-refractory iron deficiency anemia? anemia ; autosomal ; autosomal recessive ; cell ; deficiency ; gene ; hemoglobin ; hereditary ; hypochromic ; inherited ; iron ; metabolism ; molecule ; oxygen ; ...

  17. 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. PMID:26306041

  18. 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 constraints on the processes operating in the solar nebula. Although most of them probably formed through similar mechanisms, their characteristics are diverse in terms of chemistry, mineralogy, and structure. Significant differences in bulk chemistry between iron meteorites from different cores as well as variations in chemistry between meteorites from the same core provide evidence of the complex chemical evolution of these evolved meteorites. Intergroup variations for volatile siderophile elements (e.g., gallium and germanium) extend more than three orders of magnitude, hinting that iron meteorite parent bodies formed under diverse conditions. These differences reflect both the nebular source material and geological processing in the parent bodies.Can we be sure that the iron meteorites are indeed fragments of cores? Since no differentiated asteroid has yet been visited by a spacecraft, we rely on circumstantial evidence. Some M-type asteroids have spectral characteristics expected from exposed metallic cores (Tholen, 1989), while others exhibit basaltic surfaces, a hallmark of global differentiation. Although olivine-rich mantles should dominate the volume of differentiated asteroids, there is an enigmatic lack of olivine-rich asteroids (and meteorites) that could represent mantle material ( Burbine et al., 1996). Until we visit an asteroid with parts of a core-mantle boundary exposed, our best evidence supporting a core origin is detailed studies of iron meteorites.Iron-nickel alloys are expected in the cores of differentiated asteroids, but what other evidence supports the notion that iron meteorites sample the metallic cores of differentiated asteroids? What suggests that these asteroids were sufficiently heated to trigger core formation, and that iron meteorites sample cores rather than isolated pods of once molten metal? First and foremost, trace-element compositional trends in most groups of iron meteorites are consistent with fractional crystallization of a metallic melt (Scott, 1972), thus constraining peak temperatures. The temperatures required to f

  19. Iron is essential for life, being involved in cellular respiration in animals and photosynthesis in plants, as well as

    E-print Network

    Grosell, Martin

    Iron is essential for life, being involved in cellular respiration in animals and photosynthesis in plants, as well as being an integral cofactor of ribonucleotide reductase. However, in excess iron). Consequently, organisms have to regulate iron uptake to prevent the detrimental effects of tissue iron loading

  20. Iron Fractionation During Microbial Reduction of Iron

    NASA Astrophysics Data System (ADS)

    Icopini, G. A.; Brantley, S. L.; Ruebush, S.; Tien, M.; Bullen, T. D.

    2002-12-01

    The isotopic fractionation of iron during the biological reduction of iron by microbes has received much attention due to the possible use of iron isotopes as an indicator of biological activity in ancient and extraterrestrial environments. However the mechanisms of dissimilatory iron reduction have not been fully characterized. We are investigating the mechanisms by which Shewanella putrefaciens strain CN32 reduces ferric iron in the form of goethite, as well as, the resulting iron isotopic fractionation. In the experiments a PIPES buffered minimal media was used in an effort to eliminate or control the formation of secondary ferrous-iron solids. S. putrefaciens is thought to also produce an electron shuttle, which carries electrons from the cell to the iron solid. In one set of experiments, S. putrefaciens was cultured in minimal media containing goethite both with and without anthraquinone-2,6-disulfonate (AQDS, an artificial electron shuttle). Preliminary data indicates that the fractionation of iron in solution in the AQDS amended cultures is -1.57 per mil lighter than the starting goethite. This fractionation corresponds well with previously reported fractionations in similar systems. However, other researchers have shown that, in these systems, much of the reduced Fe(II) sorbs to the goethite. An acid extraction is often used to remove this sorbed Fe(II) and determine the total amount of reduced iron. This extraction was used to extract sorbed Fe(II) for isotopic analysis. Although the extraction itself may cause a fractionation effect, less than 1% of the total iron in the extraction can be attributed to this effect. Therefore, the observed fractionation should be primarily a function of the microbially reduced iron and not an artifact of the extraction. The isotope fractionation in the extraction, which includes both soluble and sorbed Fe(II), is -2.42 per mil relative to the starting goethite. We are currently combining parts of the cell involved in iron reduction (cell wall components) with an electron shuttle and goethite to accomplish in vitro Fe reduction. We will compare the in vitro iron isotope fractionations that occur without live cells to those with live cultures in an effort to elucidate iron reducing mechanisms and pathways.

  1. Iron Dextran Injection

    MedlinePLUS

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

  2. Iron in diet

    MedlinePLUS

    The best sources of iron include: Dried beans Dried fruits Eggs (especially egg yolks) Iron-fortified cereals Liver Lean red meat (especially beef) Oysters Poultry, dark red meat Salmon Tuna Whole ...

  3. 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.

  4. Ferrous Sulfate (Iron)

    MedlinePLUS

    ... the iron needed by the body to produce red blood cells. It is used to treat or prevent iron- ... that occurs when the body has too few red blood cells because of pregnancy, poor diet, excess bleeding, or ...

  5. Taking iron supplements

    MedlinePLUS

    ... taking a vitamin C supplement or drinking orange juice with your iron pill. This can help the iron absorb into your body. Drinking 8 ounces of fluid with an iron pill is also okay. Tell your health care provider about all the medicines you are ...

  6. Concurrent repletion of iron and zinc reduces intestinal oxidative damage in iron- and zinc-deficient rats

    PubMed Central

    Bodiga, Sreedhar; Krishnapillai, Madhavan Nair

    2007-01-01

    AIM: To understand the interactions between iron and zinc during absorption in iron- and zinc-deficient rats, and their consequences on intestinal oxidant-antioxidant balance. METHODS: Twenty-four weanling Wistar-Kyoto rats fed an iron- and zinc-deficient diet (< 6.5 mg Fe and 4.0 mg Zn/kg diet) for 4 wk were randomly divided into three groups (n = 8, each) and orally gavaged with 4 mg iron, 3.3 mg zinc, or 4 mg iron + 3.3 mg zinc for 2 wk. At the last day of repletion, 3 h before the animals were sacrificed, they received either 37 mBq of 55Fe or 65Zn, to study their localization in the intestine, using microautoradiography. Hemoglobin, iron and zinc content in plasma and liver were measured as indicators of iron and zinc status. Duodenal sections were used for immunochemical staining of ferritin and metallothionein. Duodenal homogenates (mitochondrial and cytosolic fractions), were used to assess aconitase activity, oxidative stress, functional integrity and the response of antioxidant enzymes. RESULTS: Concurrent repletion of iron- and zinc-deficient rats showed reduced localization of these minerals compared to rats that were teated with iron or zinc alone; these data provide evidence for antagonistic interactions. This resulted in reduced formation of lipid and protein oxidation products and better functional integrity of the intestinal mucosa. Further, combined repletion lowered iron-associated aconitase activity and ferritin expression, but significantly elevated metallothionein and glutathione levels in the intestinal mucosa. The mechanism of interactions during combined supplementation and its subsequent effects appeared to be due to through modulation of cytosolic aconitase, which in turn influenced the labile iron pool and metallothionein levels, and hence reduced intestinal oxidative damage. CONCLUSION: Concurrent administration of iron and zinc corrects iron and zinc deficiency, and also reduces the intestinal oxidative damage associated with iron supplementation. PMID:17963296

  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, radiation, and cancer

    SciTech Connect

    Stevens, R.G.; Kalkwarf, D.R. )

    1990-07-01

    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. 151 references.

  9. 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

  10. Iron-oxide catalyzed silicon photoanode for water splitting

    E-print Network

    Jun, Kimin

    2011-01-01

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

  11. 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

  12. Comparative Evaluation of Nephrotoxicity and Management by Macrophages of Intravenous Pharmaceutical Iron Formulations

    PubMed Central

    Connor, James R.; Zhang, Xuesheng; Nixon, Anne M.; Webb, Becky; Perno, Joseph R.

    2015-01-01

    Background There is a significant clinical need for effective treatment of iron deficiency. A number of compounds that can be administered intravenously have been developed. This study examines how the compounds are handled by macrophages and their relative potential to provoke oxidative stress. Methods Human kidney (HK-2) cells, rat peritoneal macrophages and renal cortical homogenates were exposed to pharmaceutical iron preparations. Analyses were performed for indices of oxidative stress and cell integrity. In addition, in macrophages, iron uptake and release and cytokine secretion was monitored. Results HK-2 cell viability was decreased by iron isomaltoside and ferumoxytol and all compounds induced lipid peroxidation. In the renal cortical homogenates, lipid peroxidation occurred at lowest concentrations with ferric carboxymaltose, iron dextran, iron sucrose and sodium ferric gluconate. In the macrophages, iron sucrose caused loss of cell viability. Iron uptake was highest for ferumoxytol and iron isomaltoside and lowest for iron sucrose and sodium ferric gluconate. Iron was released as secretion of ferritin or as ferrous iron via ferroportin. The latter was blocked by hepcidin. Exposure to ferric carboxymaltose and iron dextran resulted in release of tumor necrosis factor ?. Conclusions Exposure to iron compounds increased cell stress but was tissue and dose dependent. There was a clear difference in the handling of iron from the different compounds by macrophages that suggests in vivo responses may differ. PMID:25973894

  13. Iron and transfusion medicine.

    PubMed

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

    2013-11-01

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

  14. 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.

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

    PubMed

    Bonnefoy, Violaine; Holmes, David S

    2012-07-01

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

  16. 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

  17. 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.

  18. Physiology of iron metabolism.

    PubMed

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

    2014-06-01

    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

  19. 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

  20. 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.

  1. Human Iron?Sulfur Cluster Assembly, Cellular Iron Homeostasis, and Disease†

    PubMed Central

    2010-01-01

    Iron?sulfur (Fe?S) proteins contain prosthetic groups consisting of two or more iron atoms bridged by sulfur ligands, which facilitate multiple functions, including redox activity, enzymatic function, and maintenance of structural integrity. More than 20 proteins are involved in the biosynthesis of iron?sulfur clusters in eukaryotes. Defective Fe?S cluster synthesis not only affects activities of many iron?sulfur enzymes, such as aconitase and succinate dehydrogenase, but also alters the regulation of cellular iron homeostasis, causing both mitochondrial iron overload and cytosolic iron deficiency. In this work, we review human Fe?S cluster biogenesis and human diseases that are caused by defective Fe?S cluster biogenesis. Fe?S cluster biogenesis takes place essentially in every tissue of humans, and products of human disease genes, including frataxin, GLRX5, ISCU, and ABCB7, have important roles in the process. However, the human diseases, Friedreich ataxia, glutaredoxin 5-deficient sideroblastic anemia, ISCU myopathy, and ABCB7 sideroblastic anemia/ataxia syndrome, affect specific tissues, while sparing others. Here we discuss the phenotypes caused by mutations in these different disease genes, and we compare the underlying pathophysiology and discuss the possible explanations for tissue-specific pathology in these diseases caused by defective Fe?S cluster biogenesis. PMID:20481466

  2. 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) ...

  3. 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.

  4. Hypersensitivity from intravenous iron products.

    PubMed

    Bircher, Andreas J; Auerbach, Michael

    2014-08-01

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

  5. 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

  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, 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:...

  8. 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:...

  9. 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:...

  10. Iron age in oceanography

    NASA Astrophysics Data System (ADS)

    Coale, Kenneth H.; Worsfold, Paul; de Baar, Hein

    This last decade of the millennium could rightly be called the iron age in oceanography. The last quarter of this century has witnessed a revolution in our understanding of trace metal distributions in the world's oceans, and iron has changed more about how we think about ocean production and carbon cycling than any other element. The revolution has come about through the application of clean water sampling devices, stringent anticontamination methods, and the development of new analytical techniques. As detection limits have been reduced, the concentrations, distributions, and behavior of trace metals were revealed, like the curtain lifting on a geochemical drama. Iron plays a leading role.

  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. Saugus Iron Works Blast Furnace

    USGS Multimedia Gallery

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

  13. Limonite at Saugus Iron Works

    USGS Multimedia Gallery

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

  14. Iron overload and chelation therapy in myelodysplastic syndromes.

    PubMed

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

    2014-07-01

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

  15. 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...

  16. 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. PMID:25083899

  17. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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 obtained by any of the following processes: reduced iron, electrolytic iron, and carbonyl iron. (1)...

  18. Iron homeostasis in the liver

    PubMed Central

    Anderson, Erik R; Shah, Yatrik M

    2014-01-01

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

  19. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 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...

  20. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 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...

  1. 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...

  2. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 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...

  3. Iron and carbon isotope evidence for microbial iron respiration throughout the Archean

    E-print Network

    Iron and carbon isotope evidence for microbial iron respiration throughout the Archean Paul R: iron-formation Hamersley Isua iron carbonates iron respiration Banded Iron-Formations (BIFs that reaction between carbon and iron through microbial iron respiration [2Fe2O3nH2O+CH2O+7H+ 4Fe2+ + HCO3

  4. 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

  5. Cardioprotective activity of iron oxide nanoparticles

    PubMed Central

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

    2015-01-01

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

  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. PHOTON SCIENCE SEMINAR Diamonds, Iron and XDiamonds, Iron and XDiamonds, Iron and XDiamonds, Iron and X----rays:rays:rays:rays

    E-print Network

    Jackson, Jennifer M.

    PHOTON SCIENCE SEMINAR Diamonds, Iron and XDiamonds, Iron and XDiamonds, Iron and XDiamonds, Iron unique experimental challenges. Devices such as diamond-anvil pressure vessels and infrared lasers can

  8. Anemia caused by low iron - children

    MedlinePLUS

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

  9. 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

  10. 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.

  11. Enzymes of respiratory iron oxidation

    SciTech Connect

    Blake, R. II.

    1991-01-01

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

  12. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron,...

  13. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron,...

  14. 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,...

  15. IRON FILE SYSTEMS Vijayan Prabhakaran

    E-print Network

    Yeom, Heon Young

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

  16. IRON FILE SYSTEMS Vijayan Prabhakaran

    E-print Network

    Swift, Michael

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

  17. 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

  18. 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.

  19. Culture's Unacknowledged Iron Grip

    ERIC Educational Resources Information Center

    Engle, John

    2007-01-01

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

  20. 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)

  1. 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.

  2. The Iron Project

    NASA Technical Reports Server (NTRS)

    Pradhan, Anil K.

    2000-01-01

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

  3. 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.

  4. 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.

  5. Iron aluminide composites

    SciTech Connect

    Schneibel, J.H.

    1999-07-01

    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 microstructures, 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 of elevated temperatures (1,073 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 rule of mixtures. Interestingly, sufficiently thin ({lt}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 aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites.

  6. [Intravenous iron in general surgery].

    PubMed

    Serrablo, Alejandro; Urbieta, Elena; Carcelén-Andrés, Josefa; Ruiz, Jaime; Rodrigo, Javier; Izuel, Mónica; García-Erce, José

    2005-09-01

    Preoperative anemia is the main cause of blood transfusion in surgical patients. In digestive surgery high blood loss and allogenic blood transfusion (ABT) are associated with serious adverse events and higher mortality. Consequently, we believe that intravenous iron administration is justified to correct perioperative anemia. We present the case of a woman with metastatic colorectal adenocarcinoma in whom intravenous iron administration avoided the use of ABT. Subsequently, the iron metabolism profile improved. This had previously corresponded to a mixed pattern of iron deficiency, that is, to the association of organic and functional iron deficiency. PMID:16420822

  7. Ferrioxamine excretion in iron-loaded man

    SciTech Connect

    Pippard, M.J.; Callender, S.T.; Finch, C.A.

    1982-08-01

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

  8. 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 ?/?-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

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

    PubMed Central

    Kosman, Daniel J.

    2012-01-01

    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(H2O)6]3+. Mobilizing this iron requires bio-ferrireduction which in turn requires managing the rapid autoxidation of the resulting FeII which occurs at pH > 6. This review examines the aqueous redox chemistry of iron and the mechanisms evolved in aerobes to suppress the ‘rusting out’ of FeIII and the ROS-generating autoxidation of FeII so as to make this metal ion available as the most ubiquitous prosthetic group in metallobiology. PMID:23264695

  10. Iron versus the greenhouse

    SciTech Connect

    Monastersky, R.

    1995-09-30

    This paper reports on the possible repercussions of a Pacific Ocean experiment which demonstrated the effects of adding iron to the ocean. The plant growth stimulated was enough to use 350000 kilograms of carbon dioxide from the seawater. If performed on a large scale, fertilization of ocean water could absorb billions of tones of carbon dioxide from the air, enough to slow the rate of greenhouse warming. A variety of opinions are presented in the article.

  11. Measurement of iron absorption from meals contaminated with iron

    SciTech Connect

    Hallberg, L.; Bjoern-Rasmussen, E.

    1981-12-01

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

  12. 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

  13. 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. PMID:26194551

  14. ASSESSMENT OF SURFACE RUNOFF FROM IRON AND STEEL MILLS

    EPA Science Inventory

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

  15. 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.

  16. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  17. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  18. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation... § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line...

  19. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation... § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line...

  20. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  1. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 false Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section 192.489 Transportation...Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General...

  2. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  3. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  5. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  6. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  7. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation... § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line...

  8. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Service lines: Connections to cast iron or ductile iron mains. 192.369 Section 192.369 Transportation... § 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line...

  9. Alterations of iron distribution in Arabidopsis tissues infected by Dickeya dadantii.

    PubMed

    Aznar, Aude; Patrit, Oriane; Berger, Adeline; Dellagi, Alia

    2015-06-01

    Dickeya dadantii is a plant-pathogenic enterobacterium responsible for plant soft rot disease in a wide range of hosts, including the model plant Arabidopsis thaliana. Iron distribution in infected A.?thaliana was investigated at the cellular scale using the Perls'-diaminobenzidine-H2 O2 (PDH) method. Iron visualization during infection reveals a loss of iron from cellular compartments and plant cell walls. During symptom progression, two distinct zones are clearly visible: a macerated zone displaying weak iron content and a healthy zone displaying strong iron content. Immunolabelling of cell wall methylated pectin shows that pectin degradation is correlated with iron release from cell walls, indicating a strong relationship between cell wall integrity and iron in plant tissues. Using a D.?dadantii lipopolysaccharide antibody, we show that bacteria are restricted to the infected tissue, and that they accumulate iron in?planta. In conclusion, weak iron content is strictly correlated with bacterial cell localization in the infected tissues, indicating a crucial role of this element during the interaction. This is the first report of iron localization at the cellular level during a plant-microbe interaction and shows that PDH is a method of choice in this type of investigation. PMID:25266463

  10. Microbial reduction of iron ore

    DOEpatents

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

    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.

  11. 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.

  12. Magnetostructural study of iron sucrose

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  13. Four new iron meteorite finds

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  14. Enzymes of respiratory iron oxidation

    SciTech Connect

    Blake, R. II.

    1992-01-01

    This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.

  15. Good Sources of Nutrients: Iron 

    E-print Network

    Scott, Amanda; Replogle, Jacqueline

    2008-08-28

    children?s multivitamin pills containing iron can be dangerous if not taken as directed. Too much iron from a pill can cause serious injury, even death. To prevent this: Keep pills with iron in a child-safe container ? where your child can?t reach them... to your child only as ? directed by a health care provider. Note: Your child won?t get iron poisoning from food. Remember, ask a physician, registered dietitian or pharmacist whether you should take a dietary supple- ment such as a multivitamin pill...

  16. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section 148.275...148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is loaded in a closed hold, the...

  17. Organic phase synthesis of monodisperse iron oxide nanocrystals using iron chloride as precursor

    E-print Network

    Gao, Hongjun

    Organic phase synthesis of monodisperse iron oxide nanocrystals using iron chloride as precursor Monodisperse iron oxide nanocrystals were synthesized by a simplified method using iron chloride as precursor synthesis of mono- disperse spinel iron oxide nanocrystals using iron chloride as precursor. It was found

  18. 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 role in anaerobic energy metabolism.

  19. Genetics Home Reference: African iron overload

    MedlinePLUS

    ... in the Handbook. Where can I find additional information about African iron overload? You may find the following resources about African ... Health Dietary Supplement Fact Sheet: Iron Educational resources - ... iron overload Patient support - For patients and families American Liver ...

  20. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  1. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  2. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  3. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  4. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Chafing irons. 230.91 Section 230.91 Transportation ...Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving shall be securely...

  5. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  6. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  7. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  8. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  9. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  10. 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

  11. Iron around the clock.

    PubMed

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

    2014-07-01

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

  12. 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.

  13. 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...

  14. 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...

  15. Iron fertilization with volcanic ash?

    NASA Astrophysics Data System (ADS)

    Spirakis, Charles S.

    Martin [1990] suggests that intentional iron fertilization of nutrient-rich but iron-starved areas such as the southern oceans and equatorial Pacific might be used to stimulate organic productivity and thereby remove carbon dioxide from the atmosphere. Martin further proposes that low concentrations of atmospheric carbon dioxide during glacial times were partly the result of increased oceanic productivity stimulated by iron-bearing dust falling into oceans. Martin's work is very controversial both because the effectiveness of iron fertilization of the iron-starved parts of the oceans has been questioned [Peng and Broecker, 1991] and because proposed pilot-scale experiments to test the effects of iron addition on ocean ecology have met resistance from those who fear unanticipated and possibly harmful side effects. Of particular concern are possible long-term effects that would not necessarily be observed in proposed experiments. In this article, it is proposed that periodic additions of iron-bearing volcanic ash to the oceans represent natural iron-fertilization experiments that could be evaluated for their effects on ocean productivity.

  16. 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...

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

    PubMed Central

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

    2010-01-01

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

  18. 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. PMID:16980937

  19. 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.

  20. TCDD, dietary iron and hepatic iron distribution in female rats

    SciTech Connect

    Al-Bayati, Z.A.F.; Stohs, S.J.; Al-Turk, W.A.

    1987-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a prototype for a large group of halogenated aromatic hydrocarbons, and is the most potent of these compounds. TCDD is an environmental pollutant with exceptional toxicity for certain mammalian and avian species. The liver is one of the principal target organs affected by TCDD in the rat and other laboratory species. TCDD induces many functional, biochemical and pathological changes, including altered lipid metabolism in the liver. Ferrous iron plays an important role in the initiation of lipid peroxidation. A proposed mechanism for the production of liver injury in chronic iron overload is that organelle damage leading to cell death occurs as a result of membrane lipid peroxidation initiated and promoted by intracellular iron. The presence of iron in subcellular fractions in vitro may catalyze lipid peroxidation and produce membrane damage. There is evidence for the occurrence of hepatic lipid peroxidation after TCDD administration. The purpose of this study was to determine if TCDD induced lipid peroxidation was associated with an increase in the iron content of liver and its subcellular fractions. The effect of TCDD administration on the iron content of whole homogenate, microsomes, mitochondria, and cytosol of livers of female rats fed defined diets containing deficient, normal and excessive levels of iron for 17, 24 and 31 days was investigated.

  1. Fluidized bed for removing iron and acidity from acid mine drainage

    SciTech Connect

    Diz, H.R.; Novak, J.T.

    1998-08-01

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

  2. 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 Ocean Iron Enrichment Experiments. Seattle, WA. Geological Society of America. Coale, K., 2003. Open Ocean Iron Enrichment Experiments: What they have told us, what they have not. American Society for Limnology and Oceanography and The Oceanography Society, Honolulu, February 2004. Coale, K., 2004. Recent Research from the Southern Ocean Iron Experiment (SOFeX), in Taking the Heat: What is the impact of ocean fertilization on climate and ocean ecology? Science of earth and sky. AAAS, February 12-16, Seattle, WA

  3. Cellular and mitochondrial remodeling upon defects in iron-sulfur protein biogenesis.

    PubMed

    Hausmann, Anja; Samans, Birgit; Lill, Roland; Mühlenhoff, Ulrich

    2008-03-28

    Biogenesis of iron-sulfur (Fe/S) proteins in eukaryotes is an essential process involving the mitochondrial iron-sulfur cluster (ISC) assembly and export machineries and the cytosolic iron/sulfur protein assembly (CIA) apparatus. To define the integration of Fe/S protein biogenesis into cellular homeostasis, we compared the global transcriptional responses to defects in the three biogenesis systems in Saccharomyces cerevisiae using DNA microarrays. Depletion of a member of the CIA machinery elicited only weak (up to 2-fold) alterations in gene expression with no clear preference for any specific cellular process. In contrast, depletion of components of the mitochondrial ISC assembly and export systems induced strong and largely overlapping transcriptional responses of more than 200 genes (2-100-fold changes). These alterations were strikingly similar, yet not identical, to the transcriptional profiles developed upon iron starvation. Hence, mitochondria and their ISC systems serve as primary physiological regulators exerting a global control of numerous iron-dependent processes. First, ISC depletion activates the iron-responsive transcription factors Aft1/2p leading to increased cellular iron acquisition. Second, respiration and heme metabolism are repressed ensuring the balanced utilization of iron by the two major iron-consuming processes, iron-sulfur protein and heme biosynthesis. Third, the decreased respiratory activity is compensated by induction of genes involved in glucose acquisition. Finally, transcriptional remodeling of the citric acid cycle and the biosyntheses of ergosterol and biotin reflect the iron dependence of these pathways. Together, our data suggest a model in which mitochondria perform a global regulatory role in numerous cellular processes linked to iron homeostasis. PMID:18227070

  4. 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.

  5. Metallurgy Beyond Iron

    NASA Astrophysics Data System (ADS)

    Gallino, Isabella; Busch, Ralf

    2009-08-01

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

  6. Iron homeostasis in breast cancer.

    PubMed

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

    2014-05-28

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

  7. Multiscale Modeling of Shock-Induced Phase Transitions in Iron

    NASA Astrophysics Data System (ADS)

    Carter, Emily; Caspersen, Kyle; Lew, Adrian; Ortiz, Michael

    2004-03-01

    Multiscale Modeling of Shock-Induced Phase Transitions in Iron Emily Carter, Kyle Caspersen, Adrian Lew and Michael Ortiz We investigate the bcc to hcp phase transition in iron under both pressure and shear. We use DFT to map out the energy landscape of uniformly deformed iron, including its equation of state and its elastic moduli as a function of volume. >From these data we construct a nonlinear-elastic energy density which gives the energy density for arbitrary - not necessarily small - deformations. The energy density contains two wells corresponding to the bcc and hcp phases. We take this multi-well energy density as a basis for the investigation of the effect of shear on the phase diagram of iron. We allow for mixed states consisting alternating lamellae of bcc and hcp phases, and, for each macroscopic deformation, we determine the optimal microstructure of the mixed state by energy minimization using a sequential-lamination algorithm. We find that the superposition of shearing deformation on a volume change has the effect of inducing mixed states of varying spatial complexity, and of markedly lowering the critical transformation pressure. Indeed, we find that shear must be taken into consideration in order to obtain agreement with measured transformation pressures. Finally, we demonstrate how the microstructure model can be integrated into large-scale finite element calculations of shocked iron.

  8. Iron Isotopes in the Metal Phase of IAB Iron Meteorites

    NASA Astrophysics Data System (ADS)

    Cook, D. L.; Burkhard, R.; Schönbächler, M.; Leya, I.

    2015-07-01

    We analyzed IAB irons with a range of CRE ages to investigate whether effects from GCR may influence Fe isotopes. No resolvable anomalies were observed. Modeling of potential cosmic ray effects on Fe are underway to compare to our observations.

  9. 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.

  10. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    E-print Network

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

  11. THE IRON PROJECT Anil K. Pradhan

    E-print Network

    Pradhan, Anil

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

  12. 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...

  13. 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...

  14. Limonite Pile at Saugus Iron Works

    USGS Multimedia Gallery

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

  15. Saugus Iron Works Forge and Mill

    USGS Multimedia Gallery

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

  16. ANEMIA OF DISORDERED IRON METABOLISM AND HEME

    E-print Network

    ­ Heterogeneous aggregate of protein and iron Reference value 40-60% sideroblasts in BM REQUIREMENTS Daily Total Iron Concentration 40-50 mg Hemoglobin = 0.5 mg iron/ml blood Transferrin = Transport Protein of Individual TRANSPORT Transferrin ­ Plasma Transport Protein each gm will bind 1.4 mg of Iron TIBC = 250

  17. The Saugus Iron Works Blast Furnace

    USGS Multimedia Gallery

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

  18. Differential effects of basolateral and apical iron supply on iron transport in Caco-2 cells.

    PubMed

    Eady, J J; Wormstone, Y M; Heaton, S J; Hilhorst, B; Elliott, R M

    2015-05-01

    Iron homeostasis in the human body is maintained primarily through regulation of iron absorption in the duodenum. The liver peptide hepcidin plays a central role in this regulation. Additionally, expression and functional control of certain components of the cellular iron transport machinery can be influenced directly by the iron status of enterocytes. The significance of this modulation, relative to the effects of hepcidin, and the comparative effects of iron obtained directly from the diet and/or via the bloodstream are not clear. The studies described here were performed using Caco-2 cell monolayers as a model of intestinal epithelium, to compare the effects of iron supplied in physiologically relevant forms to either the apical or basolateral surfaces of the cells. Both sources of iron provoked increased cellular ferritin content, indicating iron uptake from both sides of the cells. Supply of basolateral transferrin-bound iron did not affect subsequent iron transport across the apical surface, but reduced iron transport across the basolateral membrane. In contrast, the apical iron supply led to subsequent reduction in iron transport across the apical cell membrane without altering iron export across the basolateral membrane. The apical and basolateral iron supplies also elicited distinct effects on the expression and subcellular distribution of iron transporters. These data suggest that, in addition to the effects of cellular iron status on the expression of iron transporter genes, different modes and direction of iron supply to enterocytes can elicit distinct functional effects on iron transport. PMID:25896409

  19. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192.373 Transportation...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron...

  20. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192.373 Transportation...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron...

  1. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  2. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192.373 Transportation...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron...

  3. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192.373 Transportation...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron...

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

    DOEpatents

    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.

  5. Extracellular Iron Biomineralization by Photoautotrophic Iron-Oxidizing Bacteria ? †

    PubMed Central

    Miot, Jennyfer; Benzerara, Karim; Obst, Martin; Kappler, Andreas; Hegler, Florian; Schädler, Sebastian; Bouchez, Camille; Guyot, François; Morin, Guillaume

    2009-01-01

    Iron oxidation at neutral pH by the phototrophic anaerobic iron-oxidizing bacterium Rhodobacter sp. strain SW2 leads to the formation of iron-rich minerals. These minerals consist mainly of nano-goethite (?-FeOOH), which precipitates exclusively outside cells, mostly on polymer fibers emerging from the cells. Scanning transmission X-ray microscopy analyses performed at the C K-edge suggest that these fibers are composed of a mixture of lipids and polysaccharides or of lipopolysaccharides. The iron and the organic carbon contents of these fibers are linearly correlated at the 25-nm scale, which in addition to their texture suggests that these fibers act as a template for mineral precipitation, followed by limited crystal growth. Moreover, we evidence a gradient of the iron oxidation state along the mineralized fibers at the submicrometer scale. Fe minerals on these fibers contain a higher proportion of Fe(III) at cell contact, and the proportion of Fe(II) increases at a distance from the cells. All together, these results demonstrate the primordial role of organic polymers in iron biomineralization and provide first evidence for the existence of a redox gradient around these nonencrusting, Fe-oxidizing bacteria. PMID:19592528

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

    DOEpatents

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

    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.

  7. Iron and Mechanisms of Emotional Behavior

    PubMed Central

    Kim, Jonghan; Wessling-Resnick, Marianne

    2014-01-01

    Iron is required for appropriate behavioral organization. Iron deficiency results in poor brain myelination and impaired monoamine metabolism. Glutamate and GABA homeostasis is modified by changes in brain iron status. Such changes not only produce 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 are 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. PMID:25154570

  8. 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.

  9. “There is iron and iron…” Burkinabè women’s perceptions of iron supplementation: a qualitative study.

    PubMed Central

    Compaore, A; Gies, S; Brabin, BJ; Tinto, H; Brabin, L

    2014-01-01

    Objectives Most pregnant women in Burkina Faso are iron deficient and many are anemic. This study assessed women’s understanding of anemia and the role of iron in preventing and treating this condition. Methods A qualitative study was conducted within a randomized controlled trial of weekly iron supplementation in a rural malaria endemic area. Focus groups with women of similar age, parity, and marital status took place in 12 of 24 study villages. Two additional focus groups were conducted with female field workers. Tape-recorded transcripts were translated into French and analyzed using Framework analysis. Results Anemia, for which no Mooré term or traditional treatment for anemia was evident, was described in terms of blood volume. Moderate blood loss (diminished blood) could be easily replaced by eating well and was not considered serious. Massive blood loss (finished blood) was a rare, life-threatening illness. Iron tablets could increase blood volume and help women withstand massive blood loss at delivery, but for the latter, transfusion was indicated. Women had no knowledge of iron’s role and did not readily concede that iron supplements contained elemental iron. Neither adolescents nor field workers were convinced of the benefits of supplementing non-pregnant adolescents, who were incorrectly considered to be at low risk of anemia. Conclusions Young women’s knowledge of anemia did not provide an adequate explanatory framework to motivate anemia prevention. Improving information on the role of iron is especially important for adolescent girls who may be incorrectly considered at low risk of anemia as they have not yet experienced pregnancy. PMID:25138626

  10. Placing Iron on Test Plate 

    E-print Network

    Unknown

    2011-08-17

    copper and aluminum for carrying the electricity and iron for use in magnets and motors. A different history exists where electricity has been used in information and signal processing. The electronics revolution has occurred because of new phenomena...

  11. Iron catalyzed coal liquefaction process

    DOEpatents

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

    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.

  12. Discovery of the Iron Isotopes

    E-print Network

    A. Schuh; A. Fritsch; M. Heim; A. Shore; M. Thoennessen

    2009-09-01

    Twenty-eight iron isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  13. Process for the synthesis of iron powder

    DOEpatents

    Welbon, William W. (Belleair, FL)

    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.

  14. 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.

  15. 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.

  16. Iron, Oxidative Stress and Gestational Diabetes

    PubMed Central

    Zhuang, Taifeng; Han, Huijun; Yang, Zhenyu

    2014-01-01

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

  17. The quantitative assessment of body iron.

    PubMed

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

    2003-05-01

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

  18. Iron Deficiency among Jamaican Adolescents

    PubMed Central

    Mason, K; Gibson, F; Hambleton, I; Serjeant, B; Serjeant, G

    2014-01-01

    ABSTRACT Objectives: To raise awareness of significant iron deficiency anaemia occurring in Jamaican secondary school students. Methods: Haematological screening of 15 592 students in the fifth and sixth forms of 14 secondary schools in the parishes of Manchester and Clarendon, Jamaica, was done. Samples were subject to haemoglobin electrophoresis, examination of haematological indices, and haemoglobin, alpha 2 (HbA2) levels where indicated. Results: Of 13 172 students with normal haemoglobin (AA) genotype aged 15–19 years, haemoglobin levels below 10 g/dL occurred in 0.36% of males and in 3.79% females. These subjects had low mean red cell volumes, low mean cell haemoglobin and high red cell distribution width, characteristic of iron deficiency, which was confirmed by dramatic increases in haemoglobin level following iron supplementation. Most revealed classic symptoms, histories of poor diets and pica, which generally resolved on iron supplementation. Conclusions: Iron deficiency, even in the absence of anaemia, is known to limit physical and mental functions and may impair intellectual performance in these high school students. Significant anaemia could be detected by incorporating a blood test into the school medical assessments performed on entry to secondary schools. There is a need for simple oral iron medications to be available at health centres. PMID:25803394

  19. 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.

  20. 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.

  1. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  4. 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.

  5. 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

  6. Hepcidin: regulation of the master iron regulator

    PubMed Central

    Rishi, Gautam; Wallace, Daniel F.; Subramaniam, V. Nathan

    2015-01-01

    Iron, an essential nutrient, is required for many diverse biological processes. The absence of a defined pathway to excrete excess iron makes it essential for the body to regulate the amount of iron absorbed; a deficiency could lead to iron deficiency and an excess to iron overload and associated disorders such as anaemia and haemochromatosis respectively. This regulation is mediated by the iron-regulatory hormone hepcidin. Hepcidin binds to the only known iron export protein, ferroportin (FPN), inducing its internalization and degradation, thus limiting the amount of iron released into the blood. The major factors that are implicated in hepcidin regulation include iron stores, hypoxia, inflammation and erythropoiesis. The present review summarizes our present knowledge about the molecular mechanisms and signalling pathways contributing to hepcidin regulation by these factors. PMID:26182354

  7. 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.

  8. Retinal iron homeostasis in health and disease

    PubMed Central

    Song, Delu; Dunaief, Joshua L.

    2013-01-01

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

  9. 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

  10. Iron deficiency in sicle cell disease.

    PubMed

    Nagaraj Rao, J; Sur, A M

    1980-05-01

    Iron studies were performed on 25 children with homozygous sickle cell disease. The majority (80%) of patients had never been transfused. Surprisingly, the results showed that all had low serum iron and low transferrin saturation. Three children had no marrow iron stores while the rest had diminished amounts of iron. This may be an important finding in view of recent efforts at fortifying common salt with iron. The exact effects of iron deficiency on sickle cell disease are not known and a controlled trial is called for. PMID:7376858

  11. 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.

  12. 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.

  13. Iron deficiency on neuronal function.

    PubMed

    Muñoz, Pablo; Humeres, Alexis

    2012-08-01

    Because of the intrinsic ability of iron to catalyze the formation of reactive oxygen species, it has been associated with oxidative stress and neurodegenerative diseases. However, iron deficiency (ID) also negatively impacts various functions of the brain, suggesting that iron plays an important physiological role in neuronal processes such as myelination, synaptogenesis, behavior and synaptic plasticity (SP). ID not only produces changes in the hippocampus, striatum, amygdale or prefrontal cortex, it also affects the interaction among these systems. In both humans and rodents, the perturbations of these structures are associated to cognitive deficits. These cognitive alterations have been well correlated with changes in neural plasticity, the possible cellular substrate of memory and learning. Given that SP is strongly affected by early ID and the lasting-neurological consequences remain even after ID has been corrected, it is important to prevent ID as well as to seek effective therapeutic interventions that reduce or reverse the long-term effects of the ID in the nervous system. This review will give an overview of the literature on the effects of iron deficit in neuronal functions such as behavior, neurotransmission and SP. We also discuss our recent data about the possible oxidative effect of iron on the mechanisms involved in neural plasticity. PMID:22639188

  14. ?-Nitro Derivatives of Iron Corrolates

    PubMed Central

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

    2012-01-01

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

  15. Iron in Parkinson's Disease Revisited

    NASA Astrophysics Data System (ADS)

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

    2002-06-01

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

  16. 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?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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. Determination of iron content and dispersity of intact ferritin by superconducting tunnel junction cryodetection mass spectrometry.

    PubMed

    Plath, Logan D; Ozdemir, Abdil; Aksenov, Alexander A; Bier, Mark E

    2015-09-01

    Ferritin is a common iron storage protein complex found in both eukaryotic and prokaryotic organisms. Although horse spleen holoferritin (HS-HoloFt) has been widely studied, this is the first report of mass spectrometry (MS) analysis of the intact form, likely because of its high molecular weight ?850 kDa and broad iron-core mass distribution. The 24-subunit ferritin heteropolymer protein shell consists of light (L) and heavy (H) subunits and a ferrihydrite-like iron core. The H/L heterogeneity ratio of the horse spleen apoferritin (HS-ApoFt) shell was found to be ?1:10 by liquid chromatography-electrospray ionization mass spectrometry. Superconducting tunneling junction (STJ) cryodetection matrix-assisted laser desorption ionization time-of-flight MS was utilized to determine the masses of intact HS-ApoFt, HS-HoloFt, and the HS-HoloFt dimer to be ?505 kDa, ?835 kDa, and ?1.63 MDa, respectively. The structural integrity of HS-HoloFt and the proposed mineral adducts found for both purified L and H subunits suggest a robust biomacromolecular complex that is internally stabilized by the iron-based core. However, cross-linking experiments of HS-HoloFt with glutaraldehyde, unexpectedly, showed the complete release of the iron-based core in a one-step process revealing a cross-linked HS-ApoFt with a narrow fwhm peak width of 31.4 kTh compared to 295 kTh for HS-HoloFt. The MS analysis of HS-HoloFt revealed a semiquantitative description of the iron content and core dispersity of 3400 ± 1600 (2?) iron atoms. Commercially prepared HS-ApoFt was estimated to still contain an average of 240 iron atoms. These iron abundance and dispersity results suggest the use of STJ cryodetection MS for the clinical analysis of iron deficient/overload diseases. PMID:26266697

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

    PubMed

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

    2015-04-01

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

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

    PubMed Central

    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

  4. 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

  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 1?, a transcription factor that normally responds to hypoxic conditions. Iron chelation has been shown to protect against disease progression and/or limit iron accumulation in some neurological disorders or their experimental models. Data from studies that administered a chelator to animals with experimental autoimmune encephalomyelitis, a model of MS, support the rationale for examining this treatment approach in MS. Preliminary clinical studies have been performed in MS patients using deferoxamine. Although some side effects were observed, the large majority of patients were able to tolerate the arduous administration regimen, i.e., 6–8 h of subcutaneous infusion, and all side effects resolved upon discontinuation of treatment. Importantly, these preliminary studies did not identify a disqualifying event for this experimental approach. More recently developed chelators, deferasirox and deferiprone, are more desirable for possible use in MS given their oral administration, and importantly, deferiprone can cross the blood–brain barrier. However, experiences from other conditions indicate that the potential for adverse events during chelation therapy necessitates close patient monitoring and a carefully considered administration regimen. PMID:24397846

  6. Complexed iron removal from groundwater

    SciTech Connect

    Munter, R.; Ojaste, H.; Sutt, J.

    2005-07-01

    The paper demonstrates an intensive work carried out and results obtained on the pilot plant of the City of Kogalym Water Treatment Station (Tjumen, Siberia, Russian Federation) to elaborate on a contemporary nonreagent treatment technology for the local iron-rich groundwater. Several filter materials (Birm, Pyrolox, hydroanthracite, Everzit, granulated activated carbon) and chemical oxidants (ozone, chlorine, hydrogen peroxide, oxygen, and potassium permanganate) were tested to solve the problem with complexed iron removal from groundwater. The final elaborated technology consists of raw water intensive aeration in the gas-degas treatment unit followed by sequential filtration through hydroanthracite and the special anthracite Everzit.

  7. Neurodegenerations with Brain Iron Accumulation.

    PubMed

    Schneider, Susanne A

    2016-01-01

    Syndromes with Neurodegeneration with Brain Iron Accumulation (NBIA) are a group of neurodegenerative disorders characterized by excess iron mainly in the globus pallidus and sometimes adjacent areas. They clinically present as hypo- and/or hyperkinetic movement disorders and a variable degree of pyramidal, cerebellar, peripheral nerve, autonomic, cognitive and psychiatric involvement and visual dysfunction. Several causative genes underlying NBIA have been identified which explain about 65% of cases. Pathophysiologically, many of the NBIA syndromes map into related biochemical pathways and gene networks including lipid metabolism. Treatment for NBIA disorders remains symptomatic. PMID:26320888

  8. Correcting Iron Deficiencies in Grain Sorghum 

    E-print Network

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

    1996-02-20

    Until grain sorghum develops an extensive root system, young plants may be unable to obtain enough ferrous iron to maintain normal growth. This publication offers strategies for avoiding, identifying and correcting iron deficiencies....

  9. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  10. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  11. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  12. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  13. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) 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, 2011 CFR

    2011-04-01

    ...) 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. 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 §...

  16. 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 §...

  17. The world iron and steel industry and its impact on Indiana iron and steel and electric utility industries

    NASA Astrophysics Data System (ADS)

    Leung, Thomas Cheong-Yuen

    In this research, a large scale mathematical programming model is developed to represent steel production and distribution. This model is used to investigate how technological changes, environmental restrictions, and government trade policies will affect future production location and relocation, world energy consumption, environmental pollution, and international trade in steel. Future potential relocation of production capacity of the world iron and steel industry will have substantial impacts on the North American electric utility industry, especially in Indiana. Given that the iron and steel industry is among the most energy intensive industries in North America, the electricity consumption of Indiana in particular is expected to change significantly as the industry adjusts to the changing environment. This research models the iron and steel industry in its use of two types of mills: integrated mills and mini-mills. Integrated mills use complex and capital intensive production processes to produce steel from iron ore, using a combination of the blast furnace and basic oxygen furnace. Mini-mills use electric melters which convert mainly scrap or directly reduced iron to steel. The model can reflect the trade and energy consequences of a chosen pattern of steel production, as well as the constraints on the pollutant generation. It also reflects various government trade policies to protect domestic steel production, such as quotas and protective tariffs. In addition, the model minimizes the total cost of steel production and transportation by evaluating the geographic patterns of the following factors: (1) iron and steel production; (2) new facility construction; (3) trade patterns. These factors are each subject to various constraints, such as demands, environmental restrictions, and government trade policies, imposed on the pattern of production. Optimization is performed for a single target year far enough in the future to allow construction of new capacity. The model also captures the transitional competition between the existing and the new capacities. Results indicate how future technological changes, environmental concerns and restrictions, and government trade policies can influence the iron and steel industry and the electric consumption of Indiana.

  18. 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 restores iron transporters in the duodenum and the liver but not in the spleen, which suggests that early-life iron deficiency may cause long term abnormalities in iron recycling from the spleen. PMID:26634050

  19. Mechanisms of cellular iron acquisition: another iron in the fire.

    PubMed

    Kaplan, Jerry

    2002-11-27

    Iron transport occurs by the well-known transferrin (Tf)-transferrin receptor (Tf receptor) system and by a second as yet uncharacterized system. Two reports in the current issue of Molecular Cell suggest an unexpected candidate for the Tf-independent system. PMID:12464171

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    E-print Network

    Buesseler, Ken

    Synthesis of iron fertilization experiments: From the Iron Age in the Age of Enlightenment Hein J; published 28 September 2005. [1] Comparison of eight iron experiments shows that maximum Chl a, the maximum IronEx-2. The two extreme experiments, EisenEx and SEEDS, can be linked via EisenEx bottle incubations

  2. 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)

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

    PubMed

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

    2013-12-10

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

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

    E-print Network

    Labbé, Simon

    element, 5 -(A/ T)GATAA-3 , located upstream of the frp1 , fip1 , and fio1 genes, is necessary for iron machinery. Iron is an essential trace element (1, 2). Because of its ability to undergo electronic changesFep1, an Iron Sensor Regulating Iron Transporter Gene Expression in Schizosaccharomyces pombe

  5. 49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  6. 49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  7. 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

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

  8. 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

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

  9. 49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  10. 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

  11. Drinking Water Problems: Iron and Manganese 

    E-print Network

    Dozier, Monty; McFarland, Mark L.

    2004-02-20

    . This is caused by colloidal iron?iron that does not form particles large enough to precipitate. Manganese usually is dissolved in water, although some shallow wells contain colloidal manganese that gives water a black tint. L-5451 2-04 Drinking Water Problems... mg/L combined concentrations of iron and manganese) Dissolved (colloidal) iron or Water is reddish or blackish Chemical oxidation and manganese (organic color from the tap and color filtration complexes of these minerals) remains longer than 24 hours...

  12. 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, and the subsequent fate (retention/export/recycling) of the biotic iron.

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

    PubMed Central

    Carpenter, Chandra; Payne, Shelley M.

    2014-01-01

    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 (FeII) or ferric (FeIII). 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. Enterobacteriacea, 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. PMID:24485010

  14. 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

  15. 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

  16. Molecular basis of iron-loading disorders.

    PubMed

    Darshan, Deepak; Frazer, David M; Anderson, Gregory J

    2010-01-01

    Iron-loading disorders (haemochromatosis) represent an important class of human diseases. Primary iron loading results from inherited disturbances in the mechanisms regulating intestinal iron absorption, such that excess iron is taken up from the diet. Body iron load can also be increased by repeated blood transfusions (secondary iron loading), usually as part of the treatment for various haematological disorders. In these syndromes, an element of enhanced iron absorption is also often involved. The central regulator of body iron trafficking is the liver-derived peptide hepcidin. Hepcidin limits iron entry into the plasma from macrophages, intestinal enterocytes and other cells by binding to the sole iron-export protein ferroportin, and facilitating its removal from the plasma membrane. Mutations in hepcidin or its upstream regulators (HFE, TFR2, HFE2 and BMP6) lead to reduced or absent hepcidin expression and a concomitant increase in iron absorption. Mutations in ferroportin that prevent hepcidin binding produce a similar result. Increased ineffective erythropoiesis, which often characterises erythrocyte disorders, also leads to reduced hepcidin expression and increased absorption. Recent advances in our understanding of hepcidin and body iron homeostasis provide the potential for a range of new diagnostic and therapeutic tools for haemochromatosis and related conditions. PMID:21054916

  17. Introduction Southern Ocean natural iron fertilization

    E-print Network

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

  18. Microbial iron respiration near 100°C

    NASA Astrophysics Data System (ADS)

    Holden, James F.; Feinberg, Lawrence F.

    2005-09-01

    Dissimilatory Fe(III) reduction (i.e., iron respiration) among hyperthermophilic microorganisms may be an ancient and widespread form of metabolism on earth and is a good candidate metabolism for putative life elsewhere. Iron respiration coupled with H2 oxidation at 100°C is highly favorable thermodynamically and can occur independent of photosynthesis. Hyperthermophilic iron reducers have been isolated from terrestrial hot springs, deep-sea hydrothermal vents, and deep (> 1,000 m) subsurface samples such as petroleum reservoirs, geothermal pools and mining operations. The hyperthermophilic archaeon Pyrobaculum aerophilum can reduce both soluble (Fe(III) citrate) and insoluble (poorly crystalline Fe(III) oxide) forms of iron. Direct contact is not necessary for reduction of insoluble iron suggesting the organism uses either an extracellular electron shuttle or a chelator for iron reduction. Growth on iron by a newly isolated Pyrobaculum sp. was measured at pH 5 where growth on O2, NO3- and S° no longer occurred, which broadened the pH range for growth of the organism. Environmental biomarkers of iron reducers may include extracellular iron chelators and electron shuttles, lipids, and 16S rRNAs. Markers of iron respiration may include magnetite formation and stable iron isotope fractionation. The identification of biomarkers for iron respiration at high temperatures is in its infancy but could provide insight into the microbial ecology of the subsurface biosphere, past and present, and provide targets for missions to other planets and moons.

  19. 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…

  20. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  1. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  2. 21 CFR 582.5375 - Iron reduced.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  3. Adipocyte iron regulates leptin and food intake.

    PubMed

    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

    2015-09-01

    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

  4. 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

  5. Ligand iron catalysts for selective hydrogenation

    DOEpatents

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

    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.

  6. IRON BIOMINERALS AS BIOMARKERS Joseph L. Kirschvink

    E-print Network

    Kirschvink, Joseph L.

    California Institute of Technology Abstract Because iron is an essential trace element in virtually all include elemental sulfur, manganese oxides, and various iron oxides.52 Often these mineral phases proveIRON BIOMINERALS AS BIOMARKERS Joseph L. Kirschvink Division of Geological and Planetary Sciences

  7. Minocycline Attenuates Iron-Induced Brain Injury.

    PubMed

    Zhao, Fan; Xi, Guohua; Liu, Wenqaun; Keep, Richard F; Hua, Ya

    2016-01-01

    Iron plays an important role in brain injury after intracerebral hemorrhage (ICH). Our previous study found minocycline reduces iron overload after ICH. The present study examined the effects of minocycline on the subacute brain injury induced by iron. Rats had an intracaudate injection of 50 ?l of saline, iron, or iron?+?minocycline. All the animals were euthanized at day 3. Rat brains were used for immunohistochemistry (n?=?5-6 per each group) and Western blotting assay (n?=?4). Brain swelling, blood-brain barrier (BBB) disruption, and iron-handling proteins were measured. We found that intracerebral injection of iron resulted in brain swelling, BBB disruption, and brain iron-handling protein upregulation (p?iron significantly reduced iron-induced brain swelling (n?=?5, p?Iron-handling protein levels in the brain, including ceruloplasmin and transferrin, were reduced in the minocycline co-injected animals. In conclusion, the present study suggests that minocycline attenuates brain swelling and BBB disruption via an iron-chelation mechanism. PMID:26463975

  8. In vivo iron metabolism by IRMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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...

  10. 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...

  11. 21 CFR 73.2250 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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...

  12. 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...

  13. 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...

  14. 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 iron deficiency, which needs to be treated in symptomatic patients. However, symptoms can already occur at ferritin levels of 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

  15. 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

  16. Redox Chemistry of Iron in Multiphase Atmosphere.

    NASA Astrophysics Data System (ADS)

    Pehkonen, Simo Olavi

    1995-01-01

    Iron redox chemistry was investigated in fog and stratus clouds in urban and remote locations in California, Delaware and New York. It was observed that iron(II) contributed from 20 to 70% of the total iron in the samples and that iron(III) was bound mostly as oxalato complexes in most samples. The iron(II) oxidation state seemed to correlate best with organic compounds, i.e., carboxylic acids and TOC (total organic carbon), indicating the important role of organic compounds to the redox state of iron. A new spectrophotometric technique for measuring simultaneously iron(II) and iron(III) in atmospheric water samples real time in the field was developed. DPKBH (Di -2-pyridyl ketone benzoylhydrazone) forms complexes with both iron(II) and iron(III) with an absorption maximum at 375 nm for both iron(II)-DPKBH and iron(III)-DPKBH and an absorption maximum at 660 nm for iron(II)-DPKBH. The detection limit of this method is 4 nM of iron with chloroform -water extraction and 0.1 ?m without the extraction. DPKBH forms bis complexes with iron and binds via the oxygen and two nitrogen atoms of the enol form of DPKBH as indicated by a FTIR study of the iron(III) -DPKBH complex. In addition to field observations, complementary laboratory photoreduction experiments were carried out with a variety of iron oxides and a variety of important atmospheric organic compounds such as oxalate, formate, acetate and formaldehyde. Photoreduction of am-Fe(OH) _3 with formate yielded the highest rates of photoreduction. Stability of the iron oxide and the strength of Fe-O bonds in the lattice played a more important role in the rate of iron photoreduction than the reactive surface area. Hydrogen peroxide was produced in the case of oxalate as the electron donor. Additional iron photoreduction experiments were carried out with halogenated acetic acids (the end products of tropospheric HCFC degradation) as electron donors and it was observed that monohalo acetic acids reduce iron oxides faster and get photooxidized faster compared to acetic acid.

  17. Electron Spectroscopy Studies of Iron, Iron Sulfides and Supported Iron Surfaces: Chemisorption of Simple Gases.

    NASA Astrophysics Data System (ADS)

    Lee, Yiu Chung

    EELS was used to investigate the chemisorption of oxygen and carbon on iron. The EELS spectra of oxidized iron show characteristic features with strong enhancement of the interband transitions involving the Fe 3d band (4.6 and 7.5 eV) and moderate enhancement of the M(,2,3) transition doublet (54.4 and 58.2 eV). The changes in the electron energy loss structures with an overlayer of graphitic or carbidic carbon were investigated. The adsorption and growth of iron on Ni(100) has been studied using the combined techniques of LEED and EELS. Initially iron grows by a layer-by-layer mechanism for the first few layers. High iron coverages result in the observation of complex LEED patterns with satellites around the main (1 x 1) diffraction sports. This is due to the formation of b.c.c. Fe(110) crystallites arranged in domains with different orientations. EELS studies show the presence of three stages in the growth of iron on Ni(100): low-coverage, film-like and bulk-like. Auger and EELS were used to study the iron sulfide (FeS(,2), Fe(,7)S(,8) and FeS) surfaces. A characteristic M(,2,3) VV Auger doublet with a separation of 5.0 eV was observed on the sulfides. An assignment of the electron energy loss peaks was made based on the energy dependence of the loss peaks and previous photoemission results. The effect of argon ion bombardment was studied. Peaks with strong iron and sulfur character were observed. Heating the damaged sulfides results in reconstruction of the sulfide surfaces. The reactions of the sulfides with simple gases, such as H(,2), CO, CH(,4), C(,2)H(,4), NH(,3) and O(,2) were also studied. Using XPS, the chemisorption of SO(,2) on CaO(100) has been studied. The chemical state of sulfur has been identified as that of sulfate. The kinetics of SO(,2) chemisorption on CaO are discussed. The binding states of Fe and Na on CaO were determined to be Fe('2+) and Na('+) respectively. At low Fe or Na coverages (< 0.5 ML), there is a large increase in the rate of sulfate formation at low SO(,2) exposures (< 3 L). This increase is explained by the 'activation' of SO(,2) chemisorption sites by Fe or Na adatoms.

  18. 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 short-term consequences of the independent and combined effects of gamma radiation and elevated body iron stores on measures of cardiac structure. We hypothesize that modifications to cardiac structure and function will be greater in rats with high body iron stores and exposed to gamma radiation than in rats that have only 1 of those treatments. Cardiac Aim 2: Identify and compare the effects of gamma radiation and elevated body iron stores on the genetic and epigenetic regulation of proteins associated with cardiac structure and function. We hypothesize that modifications of epigenetic control and posttranslational expression of proteins associated with cardiac contractile function will be differentially altered in rats with high body iron stores and exposed to gamma radiation compared to rats with only 1 type of treatment.

  19. Iron multiplets in meteor comas

    NASA Astrophysics Data System (ADS)

    Mozgova, A. M.; Churyumov, K. I.; Melnyk, M. V.

    2015-12-01

    In this paper, we present a catalog of the iron multiplets which are observed in meteor spectra. It contains the indication of energy levels terms (in eV) and wavelengths of spectral lines. Complete Grotrian diagrams are given if possible, which clearly explain the transitions that accompany the radiation in belonging to a given multiplet.

  20. Electrolytic dissolution of iron meteorites.

    PubMed

    Tackett, S L; Meyer, W M; Pany, F G; Moore, C B

    1966-08-19

    When iron meteorites are dissolved anodically in neutral solution, nonmetallic inclusions are not attached and collect at the bottom of the anode compartment. When the meteorites contain both kamacite and taenite, the kamacite dissolves preferentially, revealing a three-dimensional Widmanstätten pattern. PMID:17780649

  1. Synthesis of iron oxide nanoworms

    NASA Astrophysics Data System (ADS)

    Palchoudhury, Soubantika; Xu, Yaolin; Goodwin, Johnny; Bao, Yuping

    2011-04-01

    We report on the synthesis of highly crystalline iron oxide nanoworms via a modified "heat-up" method using iron oleate as the precursor. According to a detailed nanoparticle growth study, we proposed that the nanoworms resulted from the aggregation of spherical iron oxide nanoparticles. The aggregation was induced by the high percentage coverage of a weakly bound ligand (trioctylphosphine oxide) on the iron oxide surfaces. A time dependent study clearly demonstrated the evolution of these nanostructures from spheres to one-dimensional nanoworms. The diameter of the nanoworms was similar to the spherical nanoparticles observed at an early stage of the reaction, and the length of the nanoworms changed from 50-200 nm during the reaction. The spheres and the nanoworms were both maghemite crystal structures, but the magnetic properties changed from superparamagnetic for the spheres to ferromagnetic for the elongated nanoworms. These one dimensional structures will offer additional opportunities for biomedical applications because of their high blood circulation time and large surface area for bio-labeling.

  2. 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.

  3. Breaks National Monument Iron County

    E-print Network

    Laughlin, Robert B.

    Minersville Latimer Lund Beryl Parowan Summit Enoch Iron Springs Newcastle Zane 15 Dixie National Forest Revisions to the National Landscape Conservation System included in Public Law 111-11 are not yet reflected130 18 143 56 130 143 14 143 130 257 271 21 21 56 56 21 143 Cedar Breaks National Monument Utah

  4. Iron oxides in human spleen.

    PubMed

    Kopáni, Martin; Miglierini, Marcel; Lan?ok, Adriana; Dekan, Július; ?aplovicová, Mária; Jakubovský, Ján; Bo?a, 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 ?m 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

  5. 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

  6. Dynamic transition in supercritical iron.

    PubMed

    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

  7. ENVIRONMENTAL ASSESSMENT OF IRON CASTING

    EPA Science Inventory

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

  8. 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 ...

  9. Transformation rate between ferritin and hemosiderin assayed by serum ferritin kinetics in patients with normal iron stores and iron overload.

    PubMed

    Saito, Hiroshi; Hayashi, Hisao

    2015-11-01

    Ferritin iron, hemosiderin iron, total iron stores and transformation rate were determined by serum ferritin kinetics. The transformation rate between ferritin and hemosiderin is motivated by the potential difference between them. The transformer determines transformation rate according to the potential difference in iron mobilization and deposition. The correlations between transformation rate and iron stores were studied in 11 patients with chronic hepatitis C (CHC), 1 patent with treated iron deficiency anemia (TIDA), 9 patients with hereditary hemochromatosis (HH) and 4 patients with transfusion-dependent anemia (TD). The power regression curve of approximation showed an inverse correlation between transformation rate and ferritin iron, hemosiderin iron in part and total iron stores in HH. Such an inverse correlation between transformation rate and iron stores implies that the larger the amount of iron stores, the smaller the transformation of iron stores. On the other hand, a minimal inverse correlation between transformation rate and ferritin iron and no correlation between transformation rate and hemosiderin iron or total iron stores in CHC indicate the derangement of storage iron metabolism in the cells with CHC. Radio-iron fixation on the iron storing tissue in iron overload was larger than that in normal subjects by ferrokinetics. This is consistent with the inverse correlation between transformation rate and total iron stores in HH. The characteristics of iron turnover between ferritin and hemosiderin were disclosed from the correlation between transformation rate and ferritin iron, hemosiderin iron or total iron stores. PMID:26663936

  10. Transformation rate between ferritin and hemosiderin assayed by serum ferritin kinetics in patients with normal iron stores and iron overload

    PubMed Central

    Saito, Hiroshi; Hayashi, Hisao

    2015-01-01

    ABSTRACT Ferritin iron, hemosiderin iron, total iron stores and transformation rate were determined by serum ferritin kinetics. The transformation rate between ferritin and hemosiderin is motivated by the potential difference between them. The transformer determines transformation rate according to the potential difference in iron mobilization and deposition. The correlations between transformation rate and iron stores were studied in 11 patients with chronic hepatitis C (CHC), 1 patent with treated iron deficiency anemia (TIDA), 9 patients with hereditary hemochromatosis (HH) and 4 patients with transfusion-dependent anemia (TD). The power regression curve of approximation showed an inverse correlation between transformation rate and ferritin iron, hemosiderin iron in part and total iron stores in HH. Such an inverse correlation between transformation rate and iron stores implies that the larger the amount of iron stores, the smaller the transformation of iron stores. On the other hand, a minimal inverse correlation between transformation rate and ferritin iron and no correlation between transformation rate and hemosiderin iron or total iron stores in CHC indicate the derangement of storage iron metabolism in the cells with CHC. Radio-iron fixation on the iron storing tissue in iron overload was larger than that in normal subjects by ferrokinetics. This is consistent with the inverse correlation between transformation rate and total iron stores in HH. The characteristics of iron turnover between ferritin and hemosiderin were disclosed from the correlation between transformation rate and ferritin iron, hemosiderin iron or total iron stores. PMID:26663936

  11. Intermetallic formation and interdiffusion in diffusion couples made of uranium and single crystal iron

    NASA Astrophysics Data System (ADS)

    Chen, Tianyi; Smith, Travis A.; Gigax, Jonathan G.; Chen, Di; Balerio, Robert; Shao, Lin; Sencer, Bulent H.; Kennedy, J. Rory

    2015-12-01

    We studied the interfacial phase formation and diffusion kinetics in uranium-iron diffusion couples. A comparison was made between polycrystalline uranium (U) bonded with polycrystalline iron (FeP) and polycrystalline uranium bonded with single crystalline Fe (FeSC). After thermal annealing at 575 °C, 600 °C, 625 °C and 650 °C, respectively, diffusion and microstructures at the interface were characterized by scanning electron microscopy and transmission electron miscopy. The presence of grain boundaries in iron has a significant influence on interface reactions. In comparison with U-FeP system, interdiffusion coefficients of the U-FeSC system are significantly lower and were governed by much higher activation energies. Integrated interdiffusion coefficients and intrinsic diffusion coefficients were obtained. The intrinsic diffusion coefficients show faster diffusion of iron atoms in both U6Fe and UFe2 intermetallic phases than uranium.

  12. Hadronic Shower Development in Iron-Scintillator Tile Calorimetry

    E-print Network

    Tilecal Atlas Collaboration

    1999-04-29

    The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter uses a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behavior is obtained. The underlying radial energy densities for four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrization has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeter design.

  13. Hadronic Shower Development in Tile Iron-Scintillator Calorimetry

    E-print Network

    Yuri A. Kulchitsky

    1999-10-07

    The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter uses a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behavior is obtained. The underlying radial energy densities for four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrization has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeter design.

  14. Formation of iron-rich shelled structures by microbial communities

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  15. 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.

  16. 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.

  17. Proteomic analysis of iron acquisition, metabolic and regulatory responses of Yersinia pestis to iron starvation

    PubMed Central

    2010-01-01

    Background The Gram-negative bacterium Yersinia pestis is the causative agent of the bubonic plague. Efficient iron acquisition systems are critical to the ability of Y. pestis to infect, spread and grow in mammalian hosts, because iron is sequestered and is considered part of the innate host immune defence against invading pathogens. We used a proteomic approach to determine expression changes of iron uptake systems and intracellular consequences of iron deficiency in the Y. pestis strain KIM6+ at two physiologically relevant temperatures (26°C and 37°C). Results Differential protein display was performed for three Y. pestis subcellular fractions. Five characterized Y. pestis iron/siderophore acquisition systems (Ybt, Yfe, Yfu, Yiu and Hmu) and a putative iron/chelate outer membrane receptor (Y0850) were increased in abundance in iron-starved cells. The iron-sulfur (Fe-S) cluster assembly system Suf, adapted to oxidative stress and iron starvation in E. coli, was also more abundant, suggesting functional activity of Suf in Y. pestis under iron-limiting conditions. Metabolic and reactive oxygen-deactivating enzymes dependent on Fe-S clusters or other iron cofactors were decreased in abundance in iron-depleted cells. This data was consistent with lower activities of aconitase and catalase in iron-starved vs. iron-rich cells. In contrast, pyruvate oxidase B which metabolizes pyruvate via electron transfer to ubiquinone-8 for direct utilization in the respiratory chain was strongly increased in abundance and activity in iron-depleted cells. Conclusions Many protein abundance differences were indicative of the important regulatory role of the ferric uptake regulator Fur. Iron deficiency seems to result in a coordinated shift from iron-utilizing to iron-independent biochemical pathways in the cytoplasm of Y. pestis. With growth temperature as an additional variable in proteomic comparisons of the Y. pestis fractions (26°C and 37°C), there was little evidence for temperature-specific adaptation processes to iron starvation. PMID:20113483

  18. Intestinal iron absorption during suckling in mammals.

    PubMed

    Frazer, David M; Darshan, Deepak; Anderson, Gregory J

    2011-06-01

    The maintenance of appropriate iron levels is important for mammalian health, particularly during the rapid growth period following birth. Too little iron can lead to irreversible damage to the developing central nervous system and too much iron at this point can have adverse long term consequences, possibly due to excessive free radical production. In order to maintain iron levels, intestinal iron absorption is very efficient in young mammals, such that almost all of the iron in breast milk is utilized. However this high level of absorption is unable to be down regulated in response to excess iron as it can be in adults, implying that different regulatory processes are involved during suckling. Various mechanisms have been proposed to explain this high absorption, including enhanced expression of the proteins involved in iron absorption in adults (particularly DMT1 and ferroportin), non-specific uptake via pinocytosis, and the uptake of lactoferrin bound iron by the lactoferrin receptor. However, at present the precise mechanism is unclear. It is possible that all of these components contribute to the high intestinal iron absorption seen during suckling, or a novel, as yet undescribed, mechanism could be involved. This review summarises the evidence for and against each of the mechanisms described above and highlights how little is known about iron homeostasis in this vital stage of development. PMID:21359534

  19. 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

  20. 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.

  1. Radiation stability of iron nanoparticles irradiated with accelerated iron ions

    NASA Astrophysics Data System (ADS)

    Uglov, V. V.; Remnev, G. E.; Kvasov, N. T.; Safronov, I. V.; Shymanski, V. I.

    2015-07-01

    In the present work the dynamic processes occurring in a nanoscale iron particle exposed to irradiation with iron ions of different energies are studied in detailed. It is shown that the elastic and thermoelastic crystal lattice responses to irradiation form force factors affecting the evolution of defect-impurity system, which, in turn, leads to a decrease in the number of structural defects. Quantitative estimations of the spatial distribution of defects resulting in their migration to the surface were obtained. Such self-organization of nanoparticles exposed to ionizing radiation can be used as a basis for the production of radiation-resistant nanostructured materials capable of sustaining a long-term radiation influence.

  2. Iron requirements of infants and toddlers.

    PubMed

    Domellöf, Magnus; Braegger, Christian; Campoy, Cristina; Colomb, Virginie; Decsi, Tamas; Fewtrell, Mary; Hojsak, Iva; Mihatsch, Walter; Molgaard, Christian; Shamir, Raanan; Turck, Dominique; van Goudoever, Johannes

    2014-01-01

    Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group because their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of ID anemia (IDA) include low birth weight, high cow's-milk intake, low intake of iron-rich complementary foods, low socioeconomic status, and immigrant status. The aim of this position paper was to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight. There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of ID. There is insufficient evidence to support general iron supplementation of healthy European infants and toddlers of normal birth weight. Formula-fed infants up to 6 months of age should receive iron-fortified infant formula, with an iron content of 4 to 8 mg/L (0.6-1.2 mg(-1) · kg(-1) · day(-1)). Marginally low-birth-weight infants (2000-2500 g) should receive iron supplements of 1-2 mg(-1) · kg(-1) · day(-1). Follow-on formulas should be iron-fortified; however, there is not enough evidence to determine the optimal iron concentration in follow-on formula. From the age of 6 months, all infants and toddlers should receive iron-rich (complementary) foods, including meat products and/or iron-fortified foods. Unmodified cow's milk should not be fed as the main milk drink to infants before the age of 12 months and intake should be limited to <500 mL/day in toddlers. It is important to ensure that this dietary advice reaches high-risk groups such as socioeconomically disadvantaged families and immigrant families. PMID:24135983

  3. A Diatom Ferritin Optimized for Iron Oxidation but Not Iron Storage.

    PubMed

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

    2015-11-20

    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 Fe(3+) 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 Fe(2+) 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

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

    PubMed Central

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

    2008-01-01

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

  5. 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

  6. 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

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

    PubMed

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

    2015-01-01

    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

  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. 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. PMID:24225375

  10. Synthesis and characterization of stable iron-iron oxide core-shell nanoclusters for environmental applications.

    PubMed

    Antony, Jiji; Qiang, You; Baer, Donald R; Wang, Chongmin

    2006-02-01

    Iron-iron oxide core-shell nanoclusters are of great interest due to their potential applications as a remedy for environmental contamination. We report the room-temperature synthesis of core-shell iron-iron oxide nanoclusters using our novel cluster deposition system. Various types of measurements such as Transmission Electron Microscopy, X-ray Diffraction, X-ray Photon Spectroscopy, and Electron Energy Loss Spectroscopy are conducted in characterizing nanoclusters. Stable, monodispersive iron-iron oxide core-shell nanocrystals are identified. PMID:16573063

  11. 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.

  12. 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. PMID:17312812

  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 as an ergogenic aid: ironclad evidence?

    PubMed

    Rodenberg, Richard E; Gustafson, Shane

    2007-07-01

    Iron supplementation for the iron-depleted nonanemic athlete is a controversial issue. Athletes may be iron deficient due to poor dietary intake, significant or obligatory blood loss, or deficiency via increased need secondary to intense physical activity. Athletes who are found to be anemic secondary to iron deficiency do benefit and show improved performance with appropriate iron supplementation. There is contradictory evidence for iron supplementation and improving performance in the iron-depleted nonanemic athlete. An athlete's iron status is usually monitored via serum ferritin. Currently, there is no standardized ferritin level at which supplementation is recommended, nor is there a consensus as to the appropriate maintenance of ferritin. Screening endurance athletes or female athletes in general for iron deficiency and also educating these athletes regarding the importance of a balanced diet to maximize performance would seem prudent and beneficial. Based on the literature, supplementation for the iron-depleted nonanemic athlete does not appear to be justified to solely improve performance. PMID:17618003

  15. Integrity of 111 In-radiolabeled superparamagnetic iron oxide

    E-print Network

    Sridhar, Srinivas

    imaging (MRI), while radiolabeling the same platform with nuclear medicine isotopes allows imaging medical imaging [7]. A radionuclide commonly used in clinical nuclear medicine is 111 In. It emits gamma, with efficient detection using nuclear medicine imaging instruments [7]. Also, the half-life of 111 In is 2

  16. 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.

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

    EPA Science Inventory

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

  18. 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...

  19. 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…

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

    EPA Science Inventory

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

  1. Cloning and functional characterization of MtFRO1, a root iron reductase from Medicago truncatula

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Iron is an essential micronutrient, and although it is abundant in the soil, it can be poorly available under certain soil conditions. The activity of the Fe(III) reductase enzyme, an integral plasma membrane protein belonging to the super-family of the flavocytochromes (1), is the rate-limiting phy...

  2. Iron and iron chelators: a review on potential effects on skin aging.

    PubMed

    Pouillot, Anne; Polla, Ada; Polla, Barbara S

    2013-12-01

    Similar to oxygen, iron is essential for aerobic life and energy production. Akin to oxygen, iron can be toxic and accelerate the aging process. Indeed, via the Fenton and Haber Weiss reactions, iron potentiates the generation of highly reactive oxygen free radicals such as hydroxyl radical, thus stimulating oxidative damage. The possibility that women's longer life span relates to a lower iron status due to iron loss during reproductive life has been considered as a valid hypothesis, while hemochromatosis has been proposed as a model of iron overload to examine the effects of iron on the aging process. Iron plays an aggravating role in many diseases in which iron deprivation has been shown to be beneficial including ischaemia-reperfusion injury, neurological disorders and muscle diseases such as Duchenne's muscular dystrophy. In the skin, excess iron combined with UV radiation exerts pro-oxidant effects while scavenging of free iron prevents or inhibits the toxic effects of UV radiation on both nude mice and human skin. In this review, we propose that iron chelators and/or iron deprivation might play a significant role in the prevention of aging- associated diseases and conditions, in particular in the skin, and increase quality of life. Controlled iron deprivation might be achieved by regular blood donation in which case the quality of life of both the donor and the recipient is improved. Increasing the frequency of blood donation may thus significantly contribute to both individual and social wellbeing. Furthermore, we propose the skin as an accessible model for the study of aging and the effects of iron / iron deprivation on the aging mechanisms. Finally, we suggest that the development of topical iron chelators might represent a novel and simple approach to prevent skin aging, when such prevention has proven an important factor in increasing an aging populations' quality of life. PMID:23866012

  3. 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.

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

    PubMed Central

    Casey, J L; Di Jeso, B; Rao, K; Klausner, R D; Harford, J B

    1988-01-01

    Iron regulation of the human transferrin receptor gene was examined in murine cells transformed with chimeric constructs containing the human transferrin receptor gene's promoter and either the structural gene for bacterial chloramphenicol acetyltransferase or the human transferrin receptor cDNA. The activity of the transferrin receptor gene's promoter with the heterologous indicator gene was found to be approximately equal to 3-fold higher in cells treated with the iron chelator desferrioxamine than in cells treated with the iron source, hemin. A higher degree of iron regulation was seen in the expression of the human transferrin receptor cDNA driven by its own promoter. The receptor cDNA under the control of the simian virus 40 early promoter was also iron-regulated. Several human transferrin receptor transcripts differing in their 3' end were produced in the murine cells regardless of the promoter used, with the shorter transcripts being relatively unregulated by iron. Deletion of cDNA corresponding to most of the 3' untranslated portion of the mRNA for the receptor ablated the iron regulation. We conclude that at least two genetic elements exist for the regulation of the transferrin receptor gene by iron. One has its locus in the DNA upstream of the transferrin receptor gene's transcription start site, and the other is dependent upon the integrity of the sequences in the 3' end of the gene. Images PMID:3162307

  5. 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

  6. Regulation of heme iron absorption by young children

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. 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...

  8. 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)

  9. 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.

  10. 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

  11. The Iron Abundance of IOTA Herculis From Ultraviolet Iron Lines

    NASA Astrophysics Data System (ADS)

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

    1995-03-01

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

  12. 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.

  13. Directional Solidification of Nodular Cast Iron

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  14. Synthesis of iron based hydrocracking catalysts

    SciTech Connect

    Farcasiu, M.; Eldredge, P.A.; Ladner, E.P.

    1992-12-31

    Disclosed are method of preparing a fine particle iron based hydrocracking catalyst and the catalyst prepared thereby. An iron (III) oxide powder and elemental sulfur are reacted with a liquid hydrogen donor having a hydroaromatic structure present in the range of from about 5 to about 50 times the weight of iron (III) oxide at 180C to 240C for 0 to 8 hours. Various specific hydrogen donors are disclosed. The catalysts are active at low temperature (<350C) and low pressure.

  15. Study of iron mononitride thin films

    SciTech Connect

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

    2014-04-24

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

  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. Surface modification of high temperature iron alloys

    DOEpatents

    Park, Jong-Hee (Clarendon Hills, IL)

    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.

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

    PubMed Central

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

    2013-01-01

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

  19. Method for producing iron-based catalysts

    DOEpatents

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

    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.

  20. Perinatal iron deficiency and neurocognitive development

    PubMed Central

    Radlowski, Emily C.; Johnson, Rodney W.

    2013-01-01

    Iron deficiency is the most common form of nutrient deficiency worldwide. It is highly prevalent due to the limited availability of high quality food in developing countries and poor dietary habits in industrialized countries. According to the World Health Organization, it affects nearly 2 billion people and up to 50% of women who are pregnant. Maternal anemia during pregnancy is especially burdensome to healthy neurodevelopment in the fetus because iron is needed for proper neurogenesis, development, and myelination. Maternal anemia also increases the risk of low birth weight, either due to premature birth or fetal growth restriction, which is associated with delayed neurocognitive development and even psychiatric illness. As rapid neurodevelopment continues after birth infants that received sufficient iron in utero, but that receive a low iron diet after 6 months of age, also show deficits in neurocognitive development, including impairments in learning and memory. Unfortunately, the neurocognitive complications of iron deficiency during critical pre- and postnatal periods of brain development are difficult to remedy, persisting into adulthood. Thus, preventing iron deficiency in the pre- and postnatal periods is critical as is devising new means to recapture cognitive function in individuals who experienced early iron deficiency. This review will discuss the prevalence of pre- and postnatal iron deficiency, the mechanism, and effects of iron deficiency on brain and cognitive development. PMID:24065908

  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. 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. PMID:26378028

  3. Biosynthesis and characterization of layered iron phosphate

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  4. Processing of Goethitic Iron Ore Fines

    NASA Astrophysics Data System (ADS)

    Sharma, J.; Sharma, T.; Mandre, N. R.

    2015-10-01

    In the present investigation an attempt has been made to beneficiate goethitic iron ore containing 59.02 % Iron, 6.51 % Alumina, 4.79 % Silica, 0.089 % Phosphorus with 7.11 % loss on ignition. For this purpose, different beneficiation techniques such as gravity and magnetic separation processes have been employed. During the process two conceptual flow sheets were also developed for the beneficiation of goethite iron ore fines. In the prsent work it was possible to enhance grade of iron to 63.35, 63.18, and 65.35 % from Jigging, Multi Gravity Separation (MGS) and Wet High Intensity Magnetic Separator (WHIMS) respectively.

  5. Hepatic iron overload: Quantitative MR imaging

    SciTech Connect

    Gomori, J.M.; Horev, G.; Tamary, H.; Zandback, J.; Kornreich, L.; Zaizov, R.; Freud, E.; Krief, O.; Ben-Meir, J.; Rotem, H.

    1991-05-01

    Iron deposits demonstrate characteristically shortened T2 relaxation times. Several previously published studies reported poor correlation between the in vivo hepatic 1/T2 measurements made by means of midfield magnetic resonance (MR) units and the hepatic iron content of iron-overloaded patients. In this study, the authors assessed the use of in vivo 1/T2 measurements obtained by means of MR imaging at 0.5 T using short echo times (13.4 and 30 msec) and single-echo-sequences as well as computed tomographic (CT) attenuation as a measure of liver iron concentration in 10 severely iron-overloaded patients with beta-thalassemia major. The iron concentrations in surgical wedge biopsy samples of the liver, which varied between 3 and 9 mg/g of wet weight (normal, less than or equal to 0.5 mg/g), correlated well (r = .93, P less than or equal to .0001) with the preoperative in vivo hepatic 1/T2 measurements. The CT attenuation did not correlate with liver iron concentration. Quantitative MR imaging is a readily available noninvasive method for the assessment of hepatic iron concentration in iron-overloaded patients, reducing the need for needle biopsies of the liver.

  6. 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.

  7. 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...

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

    PubMed Central

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

    2014-01-01

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

  9. Dual selective iron chelating probes with a potential to monitor mitochondrial labile iron pools.

    PubMed

    Abbate, Vincenzo; Reelfs, Olivier; Kong, Xiaole; Pourzand, Charareh; Hider, Robert C

    2015-12-24

    Mitochondria-targeted peptides incorporating dual fluorescent and selective iron chelators have been designed as novel biosensors for the mitochondrial labile iron pool. The probes were demonstrated to specifically co-localize with mitochondria and their fluorescence emission was found to be sensitive to the presence of iron. PMID:26567874

  10. Bordetella pertussis FbpA Binds Both Unchelated Iron and Iron Siderophore Complexes

    PubMed Central

    2015-01-01

    Bordetella pertussis is the causative agent of whooping cough. This pathogenic bacterium can obtain the essential nutrient iron using its native alcaligin siderophore and by utilizing xeno-siderophores such as desferrioxamine B, ferrichrome, and enterobactin. Previous genome-wide expression profiling identified an iron repressible B. pertussis gene encoding a periplasmic protein (FbpABp). A previously reported crystal structure shows significant similarity between FbpABp and previously characterized bacterial iron binding proteins, and established its iron-binding ability. Bordetella growth studies determined that FbpABp was required for utilization of not only unchelated iron, but also utilization of iron bound to both native and xeno-siderophores. In this in vitro solution study, we quantified the binding of unchelated ferric iron to FbpABp in the presence of various anions and importantly, we demonstrated that FbpABp binds all the ferric siderophores tested (native and xeno) with ?M affinity. In silico modeling augmented solution data. FbpABp was incapable of iron removal from ferric xeno-siderophores in vitro. However, when FbpABp was reacted with native ferric-alcaligin, it elicited a pronounced change in the iron coordination environment, which may signify an early step in FbpABp-mediated iron removal from the native siderophore. To our knowledge, this is the first time the periplasmic component of an iron uptake system has been shown to bind iron directly as Fe3+ and indirectly as a ferric siderophore complex. PMID:24873326

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

    E-print Network

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Iron Supplementation in Suckling Piglets: How to Correct Iron Deficiency Anemia without Affecting Plasma Hepcidin Levels

    PubMed Central

    Starzy?ski, Rafa? R.; Laarakkers, Coby M. M.; Tjalsma, Harold; Swinkels, Dorine W.; Pieszka, Marek; Sty?, Agnieszka; Mickiewicz, Micha?; Lipi?ski, Pawe?

    2013-01-01

    The aim of the study was to establish an optimized protocol of iron dextran administration to pig neonates, which better meets the iron demand for erythropoiesis. Here, we monitored development of red blood cell indices, plasma iron parameters during a 28-day period after birth (till the weaning), following intramuscular administration of different concentrations of iron dextran to suckling piglets. To better assess the iron status we developed a novel mass spectrometry assay to quantify pig plasma levels of the iron-regulatory peptide hormone hepcidin-25. This hormone is predominantly secreted by the liver and acts as a negative regulator of iron absorption and reutilization. The routinely used protocol with high amount of iron resulted in the recovery of piglets from iron deficiency but also in strongly elevated plasma hepcidin-25 levels. A similar protocol with reduced amounts of iron improved hematological status of piglets to the same level while plasma hepcidin-25 levels remained low. These data show that plasma hepcidin-25 levels can guide optimal dosing of iron treatment and pave the way for mixed supplementation of piglets starting with intramuscular injection of iron dextran followed by dietary supplementation, which could be efficient under condition of very low plasma hepcidin-25 level. PMID:23737963

  14. Iron supply to the western subarctic Pacific: Importance of iron export from the Sea of Okhotsk

    NASA Astrophysics Data System (ADS)

    Nishioka, Jun; Ono, Tsuneo; Saito, Hiroaki; Nakatsuka, Takeshi; Takeda, Shigenobu; Yoshimura, Takeshi; Suzuki, Koji; Kuma, Kenshi; Nakabayashi, Shigeto; Tsumune, Daisuke; Mitsudera, Humio; Johnson, W. Keith; Tsuda, Atsushi

    2007-10-01

    Iron is an essential nutrient and plays an important role in the control of phytoplankton growth (Martin et al., 1989). Atmospheric dust has been thought to be the most important source of iron, supporting annual biological production in the western subarctic Pacific (WSP) (Duce and Tindale, 1991; Moore et al., 2002). We argue here for another source of iron to the WSP. We found extremely high concentrations of dissolved and particulate iron in the Okhotsk Sea Intermediate Water (OSIW) and the North Pacific Intermediate Water (NPIW), and water ventilation processes in this region probably control the transport of iron through the intermediate water layer from the continental shelf of the Sea of Okhotsk to wide areas of the WSP. Additionally, our time series data in the Oyashio region of the WSP indicate that the pattern of seasonal changes in dissolved iron concentrations in the surface-mixed layer was similar to that of macronutrients, and that deep vertical water mixing resulted in higher winter concentrations of iron in the surface water of this region. The estimated dissolved iron supply from the iron-rich intermediate waters to the surface waters in the Oyashio region was comparable to or higher than the reported atmospheric dust iron input and thus a major source of iron to these regions. Our data suggest that the consideration of this source of iron is essential in our understanding of spring biological production and biogeochemical cycles in the western subarctic Pacific and the role of the marginal sea.

  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. 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 as suggested by measurements over the Atlantic Ocean. Our results imply that the dissolution of iron in African dust is generally slower than that in Asian dust. Conventionally, dust is assumed as the major supply of bioavailable iron with a constant solubility at 1-2% to the remote ocean. Therefore, the timing and location of the atmospheric iron input to the ocean with detailed modeling of atmospheric processing could be different from those previously assumed. Past and future changes in aerosol supply of bioavailable iron might play a greater role in the nutrient supply for phytoplankton production in the upper ocean, as global warming has been predicted to intensify stratification and reduce vertical mixing from the deep ocean. Thus the feedback of climate change through ocean uptake of carbon dioxide as well as via aerosol-cloud interaction might be modified by the inclusion of iron chemistry in the atmosphere.

  17. Electrodynamics in Iron and Steel

    E-print Network

    John Paul Wallace

    2009-06-03

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

  18. 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

  19. 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

  20. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Iron, citrate phosphate potassium complexes. 721.10357 Section 721...721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical substance...identified as iron, citrate phosphate potassium complexes (PMN P-09-382;...

  1. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Iron, citrate phosphate potassium complexes. 721.10357 Section 721...721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical substance...identified as iron, citrate phosphate potassium complexes (PMN P-09-382;...

  2. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Iron, citrate phosphate potassium complexes. 721.10357 Section 721...721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical substance...identified as iron, citrate phosphate potassium complexes (PMN P-09-382;...

  3. 49 CFR 236.532 - Strap iron inductor; use restricted.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  4. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  5. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  6. 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

  7. 49 CFR 236.532 - Strap iron inductor; use restricted.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  8. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 6 2012-04-01 2012-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

  9. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  10. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  11. 49 CFR 236.532 - Strap iron inductor; use restricted.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  12. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  13. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  14. 49 CFR 236.532 - Strap iron inductor; use restricted.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  15. 49 CFR 236.532 - Strap iron inductor; use restricted.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Strap iron inductor; use restricted. 236.532...Instructions; Roadway § 236.532 Strap iron inductor; use restricted. No railroad shall use strap iron inductor or other roadway element...

  16. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 3 2013-04-01 2013-04-01 false Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

  17. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  18. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  19. 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 ...

  20. Iron Cycling and Redox Evolution in the Precambrian

    E-print Network

    Planavsky, Noah John

    2012-01-01

    sorption to iron oxides. Iron-silica co-precipitationiron oxide-rich sediments. Importantly, with the exception of silica,iron oxide-rich sedimentary rocks can be used to track dissolved phosphate concentrations if the dissolved silica

  1. Iron-Accelerated Neuronal Differentiation of Human Embryonic Stem Cells

    E-print Network

    Lu, David Tong

    2014-01-01

    Klausner RD, et al. Iron-responsive elements: regulatory RNAin critical demand. Iron, a trace element, is essential forELEMENTS software. Final ratios that were derived by dividing total intensity of axons cultured with iron

  2. Ironic effects of sleep urgency.

    PubMed

    Ansfield, M E; Wegner, D M; Bowser, R

    1996-07-01

    Normal sleepers were instructed either to fall asleep as quickly as they could or to fall asleep whenever they desired, under a high mental load (listening to John Philip Sousa marches) or a low mental load (listening to sleep-conducive new age music). Under low load, participants trying to fall asleep quickly did so faster than those attempting only to fall asleep whenever they desired. Under high load, however, and consistent with the ironic process theory of mental control (Wegner, D. M., 1994, Psychological Review, 101, 34-52), sleep onset latency was greater for participants attempting to fall asleep quickly than for those not attempting to do so. PMID:8826759

  3. Iron Indices in Bottlenose Dolphins (Tursiops truncatus)

    PubMed Central

    Mazzaro, Lisa M; Johnson, Shawn P; Fair, Patricia A; Bossart, Greg; Carlin, Kevin P; Jensen, Eric D; Smith, Cynthia R; Andrews, Gordon A; Chavey, Patricia S; Venn-Watson, Stephanie

    2012-01-01

    Bottlenose dolphins can have iron overload (that is, hemochromatosis), and managed populations of dolphins may be more susceptible to this disease than are wild dolphins. Serum iron, total iron-binding capacity (TIBC), transferrin saturation, and ferritin were measured in 181 samples from 141 dolphins in 2 managed collections and 2 free-ranging populations. Although no iron indices increased with age among free-ranging dolphins, ferritin increased with age in managed collections. Dolphins from managed collections had higher iron, ferritin, and transferrin saturation values than did free-ranging dolphins. Dolphins with high serum iron (exceeding 300 ?g/dL) were more likely to have elevated ferritin but not ceruloplasmin or haptoglobin, demonstrating that high serum levels of iron are due to a true increase in total body iron. A time-series study of 4 dolphins with hemochromatosis that were treated with phlebotomy demonstrated significant decreases in serum ferritin, iron, and TIBC between pre- and posttreatment samples; transferrin saturation initially fell but returned to prephlebotomy levels by 6 mo after treatment. Compared with those in managed collections, wild dolphins were 15 times more likely to have low serum iron (100 ?g/dL or less), and this measure was associated with lower haptoglobin. In conclusion, bottlenose dolphins in managed collections are more likely to have greater iron stores than are free-ranging dolphins. Determining why this situation occurs among some dolphin populations and not others may improve the treatment of hemochromatosis in dolphins and provide clues to causes of nonhereditary hemochromatosis in humans. PMID:23561885

  4. 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.

  5. Iron absorption is more closely related to iron status than to daily iron intake in 12- to 48-mo-old children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few studies have evaluated iron absorption in small children after the first year of life. Our objective was to examine the relations among iron intake, iron absorption, and iron status in a group of healthy children. We studied 28 children, ages 12 to 48 mo, after a 7-d home adaptation to a diet re...

  6. Cytosolic Monothiol Glutaredoxins Function in Intracellular Iron Sensing and Trafficking via Their Bound Iron-Sulfur Cluster

    E-print Network

    Mühlenhoff, Ulrich

    Iron is an essential nutrient for cells. It is unknown how iron, after its import into the cytosol, is specifically delivered to iron-dependent processes in various cellular compartments. Here, we identify an essential ...

  7. 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)

  8. 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].

  9. Carburizer Effect on Cast Iron Solidification

    NASA Astrophysics Data System (ADS)

    Janerka, Krzysztof; Kondracki, Marcin; Jezierski, Jan; Szajnar, Jan; Stawarz, Marcin

    2014-06-01

    This paper presents the effect of carburizing materials on cast iron solidification and crystallization. The studies consisted of cast iron preparation from steel scrap and different carburizers. For a comparison, pig iron was exclusively used in a solid charge. Crystallization analysis revealed the influence of the carburizer material on the crystallization curves as well as differences in the solidification paths of cast iron prepared with the use of different charge materials. The carburizers' influence on undercooling during the eutectic crystallization process was analyzed. The lowest undercooling rate was recorded for the melt with pig iron, then for synthetic graphite, natural graphite, anthracite, and petroleum coke (the highest undercooling rate). So a hypothesis was formulated that eutectic cells are created most effectively with the presence of carbon from pig iron (the highest nucleation potential), and then for the graphite materials (crystallographic similarity with the carbon precipitation in the cast iron). The most difficult eutectic crystallization is for anthracite and petroleum coke (higher undercooling is necessary). This knowledge can be crucial when the foundry plant is going to change the solid charge composition replacing the pig iron by steel scrap and the recarburization process.

  10. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...It is stable in dry air. (3) Carbonyl iron is prepared by the decomposition of iron pentacarbonyl. It occurs as a dark gray powder. When viewed under a microscope, it appears as spheres built up with concentric shells. It is stable in dry...

  11. 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.

  12. 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.

  13. The Iron abundance in Galactic Planetary Nebulae

    E-print Network

    G. Delgado-Inglada; M. Rodriguez; A. Mampaso; K. Viironen

    2009-03-31

    We constrain the iron abundance in a sample of 33 low-ionization Galactic planetary nebulae (PNe) using [Fe III] lines and correcting for the contribution of higher ionization states with ionization correction factors (ICFs) that take into account uncertainties in the atomic data. We find very low iron abundances in all the objects, suggesting that more than 90% of their iron atoms are condensed onto dust grains. This number is based on the solar iron abundance and implies a lower limit on the dust-to-gas mass ratio, due solely to iron, of M_dust/M_gas>1.3x10^{-3} for our sample. The depletion factors of different PNe cover about two orders of magnitude, probably reflecting differences in the formation, growth, or destruction of their dust grains. However, we do not find any systematic difference between the gaseous iron abundances calculated for C-rich and O-rich PNe, suggesting similar iron depletion efficiencies in both environments. The iron abundances of our sample PNe are similar to those derived following the same procedure for a group of 10 Galactic H II regions. These high depletion factors argue for high depletion efficiencies of refractory elements onto dust grains both in molecular clouds and AGB stars, and low dust destruction efficiencies both in interstellar and circumstellar ionized gas.

  14. 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...

  15. Mesoscale Iron Enrichment Experiments 19932005: Synthesis

    E-print Network

    Buesseler, Ken

    in major nutrient-rich waters is limited by iron deficiency" (2). The candidate mechanism of Martin (1, 2Mesoscale Iron Enrichment Experiments 1993­2005: Synthesis and Future Directions P. W. Boyd,1 * T. Watson2 Since the mid-1980s, our understanding of nutrient limitation of oceanic primary production has

  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, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5375 Iron reduced. (a) Product....

  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, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5375 Iron reduced. (a) Product....

  18. 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…

  19. Production of iron from metallurgical waste

    SciTech Connect

    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.

  20. Iron deficiency anemia in inflammatory bowel disease.

    PubMed

    Kaitha, Sindhu; Bashir, Muhammad; Ali, Tauseef

    2015-08-15

    Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD) and is frequently overlooked as a complication. Patients with IBD are commonly found to have iron deficiency anemia (IDA) secondary to chronic blood loss, and impaired iron absorption due to tissue inflammation. Patients with iron deficiency may not always manifest with signs and symptoms; so, hemoglobin levels in patients with IBD must be regularly monitored for earlier detection of anemia. IDA in IBD is associated with poor quality of life, necessitating prompt diagnosis and appropriate treatment. IDA is often associated with inflammation in patients with IBD. Thus, commonly used laboratory parameters are inadequate to diagnose IDA, and newer iron indices, such as reticulocyte hemoglobin content or percentage of hypochromic red cells or zinc protoporphyrin, are required to differentiate IDA from anemia of chronic disease. Oral iron preparations are available and are used in patients with mild disease activity. These preparations are inexpensive and convenient, but can produce gastrointestinal side effects, such as abdominal pain and diarrhea, that limit their use and patient compliance. These preparations are partly absorbed due to inflammation. Non-absorbed iron can be toxic and worsen IBD disease activity. Although cost-effective intravenous iron formulations are widely available and have improved safety profiles, physicians are reluctant to use them. We present a review of the pathophysiologic mechanisms of IDA in IBD, improved diagnostic and therapeutic strategies, efficacy, and safety of iron replacement in IBD. PMID:26301120

  1. Iron deficiency anemia in inflammatory bowel disease

    PubMed Central

    Kaitha, Sindhu; Bashir, Muhammad; Ali, Tauseef

    2015-01-01

    Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD) and is frequently overlooked as a complication. Patients with IBD are commonly found to have iron deficiency anemia (IDA) secondary to chronic blood loss, and impaired iron absorption due to tissue inflammation. Patients with iron deficiency may not always manifest with signs and symptoms; so, hemoglobin levels in patients with IBD must be regularly monitored for earlier detection of anemia. IDA in IBD is associated with poor quality of life, necessitating prompt diagnosis and appropriate treatment. IDA is often associated with inflammation in patients with IBD. Thus, commonly used laboratory parameters are inadequate to diagnose IDA, and newer iron indices, such as reticulocyte hemoglobin content or percentage of hypochromic red cells or zinc protoporphyrin, are required to differentiate IDA from anemia of chronic disease. Oral iron preparations are available and are used in patients with mild disease activity. These preparations are inexpensive and convenient, but can produce gastrointestinal side effects, such as abdominal pain and diarrhea, that limit their use and patient compliance. These preparations are partly absorbed due to inflammation. Non-absorbed iron can be toxic and worsen IBD disease activity. Although cost-effective intravenous iron formulations are widely available and have improved safety profiles, physicians are reluctant to use them. We present a review of the pathophysiologic mechanisms of IDA in IBD, improved diagnostic and therapeutic strategies, efficacy, and safety of iron replacement in IBD. PMID:26301120

  2. Obesity Promotes Alterations in Iron Recycling

    PubMed Central

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

  3. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...and conditions of us e. It is used in baby pigs by sponsors in § 510.600(c) of...as follows: (i) For prevention of baby pig anemia due to iron deficiency, intramuscularly...days of age. (ii) For treatment of baby pig anemia due to iron deficiency,...

  4. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...and conditions of us e. It is used in baby pigs by sponsors in § 510.600(c) of...as follows: (i) For prevention of baby pig anemia due to iron deficiency, intramuscularly...days of age. (ii) For treatment of baby pig anemia due to iron deficiency,...

  5. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...and conditions of us e. It is used in baby pigs by sponsors in § 510.600(c) of...as follows: (i) For prevention of baby pig anemia due to iron deficiency, intramuscularly...days of age. (ii) For treatment of baby pig anemia due to iron deficiency,...

  6. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...and conditions of us e. It is used in baby pigs by sponsors in § 510.600(c) of...as follows: (i) For prevention of baby pig anemia due to iron deficiency, intramuscularly...days of age. (ii) For treatment of baby pig anemia due to iron deficiency,...

  7. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...and conditions of us e. It is used in baby pigs by sponsors in § 510.600(c) of...as follows: (i) For prevention of baby pig anemia due to iron deficiency, intramuscularly...days of age. (ii) For treatment of baby pig anemia due to iron deficiency,...

  8. 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.

  9. 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,…

  10. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...is an amorphous, lusterless, grayish-black powder. It is stable in dry air. (3) Carbonyl iron is prepared by the decomposition of iron pentacarbonyl. It occurs as a dark gray powder. When viewed under a microscope, it appears as spheres built...

  11. Dechlorination of TCE with palladized iron

    DOEpatents

    Fernando, Quintus (Tucson, AZ); Muftikian, Rosy (Tucson, AZ); Korte, Nic (Grand Junction, CO)

    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.

  12. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... follows: (i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular injection at 2 to 4 days of age. (ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by... described in paragraph (a)(1)(i) of this section as follows: (i) For the prevention of anemia due to...

  13. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... follows: (i) For prevention of iron deficiency anemia, inject 100 mg (1 mL) by intramuscular injection at 2 to 4 days of age. (ii) For treatment of iron deficiency anemia, inject 100 mg (1 mL) by... described in paragraph (a)(1)(i) of this section as follows: (i) For the prevention of anemia due to...

  14. Formation and Reactivity of Biogenic Iron Minerals

    SciTech Connect

    Ferris, F. Grant

    1999-06-01

    This objective of this research is to evaluate the formation and reactivity of biogenic iron minerals produced by dissimilatory iron-reducing bacteria, particularly with respect to the solid phase incorporation of metal contaminants (e.g., uranium, chromium, and nickel).

  15. 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 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...

  16. 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 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...

  17. Removal of Metallic Iron on Oxide Slags

    NASA Astrophysics Data System (ADS)

    Shannon, George N.; Fruehan, R. J.; Sridhar, Seetharaman

    2009-10-01

    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 ({p_{O2}} of approximately 10-4 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 °C and in 160 seconds at 1600 °C.

  18. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...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 § 186.1(b)(1), the...

  19. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...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 § 186.1(b)(1), the...

  20. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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 § 186.1(b)(1), the...

  1. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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 § 186.1(b)(1), the...

  2. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...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 § 186.1(b)(1), the...

  3. Nickel-iron spherules from aouelloul glass

    USGS Publications Warehouse

    Chao, E.C.T.; Dwornik, E.J.; Merrill, C.W.

    1966-01-01

    Nickel-iron spherules, ranging from less than 0.2 to 50 microns in diameter and containing 1.7 to 9.0 percent Ni by weight, occur in glass associated with the Aouelloul crater. They occur in discrete bands of siliceous glass enriched in dissolved iron. Their discovery is significant tangible evidence that both crater and glass originated from terrestrial impact.

  4. 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...

  5. 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.

  6. 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.

  7. Process to Produce Iron Nanoparticle Lunar Dust Simulant Composite

    NASA Technical Reports Server (NTRS)

    Hung, Ching-cheh; McNatt, Jeremiah

    2010-01-01

    A document discusses a method for producing nanophase iron lunar dust composite simulant by heating a mixture of carbon black and current lunar simulant types (mixed oxide including iron oxide) at a high temperature to reduce ionic iron into elemental iron. The product is a chemically modified lunar simulant that can be attracted by a magnet, and has a surface layer with an iron concentration that is increased during the reaction. The iron was found to be -iron and Fe3O4 nanoparticles. The simulant produced with this method contains iron nanoparticles not available previously, and they are stable in ambient air. These nanoparticles can be mass-produced simply.

  8. Reconstruction of Gene Networks of Iron Response in Shewanella oneidensis

    SciTech Connect

    Yang, Yunfeng; Harris, Daniel P; Luo, Feng; Joachimiak, Marcin; Wu, Liyou; Dehal, Paramvir; Jacobsen, Janet; Yang, Zamin Koo; Gao, Haichun; Arkin, Adam; Palumbo, Anthony Vito; Zhou, Jizhong

    2009-01-01

    It is of great interest to study the iron response of the -proteobacterium Shewanella oneidensis since it possesses a high content of iron and is capable of utilizing iron for anaerobic respiration. We report here that the iron response in S. oneidensis is a rapid process. To gain more insights into the bacterial response to iron, temporal gene expression profiles were examined for iron depletion and repletion, resulting in identification of iron-responsive biological pathways in a gene co-expression network. Iron acquisition systems, including genes unique to S. oneidensis, were rapidly and strongly induced by iron depletion, and repressed by iron repletion. Some were required for iron depletion, as exemplified by the mutational analysis of the putative siderophore biosynthesis protein SO3032. Unexpectedly, a number of genes related to anaerobic energy metabolism were repressed by iron depletion and induced by repletion, which might be due to the iron storage potential of their protein products. Other iron-responsive biological pathways include protein degradation, aerobic energy metabolism and protein synthesis. Furthermore, sequence motifs enriched in gene clusters as well as their corresponding DNA-binding proteins (Fur, CRP and RpoH) were identified, resulting in a regulatory network of iron response in S. oneidensis. Together, this work provides an overview of iron response and reveals novel features in S. oneidensis, including Shewanella-specific iron acquisition systems, and suggests the intimate relationship between anaerobic energy metabolism and iron response.

  9. Experimental animal model to study iron overload and iron chelation and review of other such models.

    PubMed

    Italia, Khushnooma; Colah, Roshan; Ghosh, Kanjaksha

    2015-10-01

    The disorders of iron overload due to primary or secondary cause are one of the important human diseases leading to high mortality if untreated. To understand this, an animal model has been extensively studied. The source of iron administered to the mode of iron administration that can mimic the iron overload in humans has been studied. A safe and orally active iron chelator is still needed as many of the existing compounds have different types of complications and toxicity associated. Hence having a simple animal model which can be availed quickly and can be used to study various compounds for its iron chelating activity would likely to have immense utility for pharmacological studies. In this review we have shown how, using a simple procedure, a large number of small iron overloaded animals can be produced easily for various studies. PMID:26227843

  10. Fossilized iron bacteria reveal a pathway to the biological origin of banded iron formation.

    PubMed

    Chi Fru, Ernest; Ivarsson, Magnus; Kilias, Stephanos P; Bengtson, Stefan; Belivanova, Veneta; Marone, Federica; Fortin, Danielle; Broman, Curt; Stampanoni, Marco

    2013-01-01

    Debates on the formation of banded iron formations in ancient ferruginous oceans are dominated by a dichotomy between abiotic and biotic iron cycling. This is fuelled by difficulties in unravelling the exact processes involved in their formation. Here we provide fossil environmental evidence for anoxygenic photoferrotrophic deposition of analogue banded iron rocks in shallow marine waters associated with an Early Quaternary hydrothermal vent field on Milos Island, Greece. Trace metal, major and rare earth elemental compositions suggest that the deposited rocks closely resemble banded iron formations of Precambrian origin. Well-preserved microbial fossils in combination with chemical data imply that band formation was linked to periodic massive encrustation of anoxygenic phototrophic biofilms by iron oxyhydroxide alternating with abiotic silica precipitation. The data implicate cyclic anoxygenic photoferrotrophy and their fossilization mechanisms in the construction of microskeletal fabrics that result in the formation of characteristic banded iron formation bands of varying silica and iron oxide ratios. PMID:23784372

  11. Iron deposition in modern and archaeological teeth

    NASA Astrophysics Data System (ADS)

    Williams, A.-M. M.; Siegele, R.

    2014-09-01

    Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment.

  12. Studies of the kinetics and mechanisms of perfluoroether reactions on iron and oxidized iron surfaces

    NASA Technical Reports Server (NTRS)

    Napier, Mary E.; Stair, Peter C.

    1992-01-01

    Polymeric perfluoroalkylethers are being considered for use as lubricants in high temperature applications, but have been observed to catalytically decompose in the presence of metals. X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD) were used to explore the decomposition of three model fluorinated ethers on clean polycrystalline iron surfaces and iron surfaces chemically modified with oxygen. Low temperature adsorption of the model fluorinated ethers on the clean, oxygen modified and oxidized iron surfaces was molecular. Thermally activated defluorination of the three model compounds was observed on the clean iron surface at remarkably low temperatures, 155 K and below, with formation of iron fluoride. Preferential C-F bond scission occurred at the terminal fluoromethoxy, CF3O, of perfluoro-1-methoxy-2-ethoxy ethane and perfluoro-1-methoxy-2-ethoxy propane and at CF3/CF2O of perfluoro-1,3-diethoxy propane. The reactivity of the clean iron toward perfluoroalkylether decomposition when compared to other metals is due to the strength of the iron fluoride bond and the strong electron donating ability of the metallic iron. Chemisorption of an oxygen overlayer lowered the reactivity of the iron surface to the adsorption and decomposition of the three model fluorinated ethers by blocking active sites on the metal surface. Incomplete coverage of the iron surface with chemisorbed oxygen results in a reaction which resembles the defluorination reaction observed on the clean iron surface. Perfluoro-1-methoxy-2-ethoxy ethane reacts on the oxidized iron surface at 138 K, through a Lewis acid assisted cleavage of the carbon oxygen bond, with preferential attack at the terminal fluoromethoxy, CF3O. The oxidized iron surface did not passivate, but became more reactive with time. Perfluoro-1-methoxy-2-ethoxy propane and perfluoro-1,3-diethoxy propane desorbed prior to the observation of decomposition on the oxidized iron surface.

  13. Iron and Carbon Isotope Evidence for Microbial Iron Respiration Throughout the Archean

    NASA Astrophysics Data System (ADS)

    Craddock, P. R.; Dauphas, N.

    2010-12-01

    Banded Iron-Formations (BIFs) are voluminous chemical sediments that are rich in iron-oxide, carbonate and silica and whose occurrence is unique to the Precambrian. Their preservation in the geological records offers insights to the surface chemical and biological cycling of iron and carbon on early Earth. However, many details regarding the role of microbial activity in BIF deposition and diagenesis are unresolved. Laboratory studies have shown that reaction between carbon and iron through microbial iron respiration (4Fe(OH)3 + [CH2O] + 7H+ ? 4Fe2+ + HCO3- + 10H2O + chemical energy) can impart fractionation to the isotopic compositions of these elements. Here, we report iron (?56Fe, vs. IRMM-014) and carbon isotopic (?13C, vs. V-PDB) compositions of magnetite and of iron-rich (siderite, ankerite) and iron-poor carbonates (calcite, dolomite) in BIFs from the late Archean (~2.5 Ga) Hamersley Basin, Australia and the early Archean (~3.8 Ga) Isua Supracrustal Belt (ISB), Greenland. The range of ?56Fe values measured in the Hamersley Basin, including light values in magnetite (as low as -1.0 ‰) and heavy values in iron-rich carbonates (up to +1.2 ‰), are incompatible with their precipitation in equilibrium with seawater. Rather, the isotopic compositions of Fe-rich carbonates together with previously reported light ?13C values in these same carbonates record evidence for diagenetic reduction of ferric oxide precursors to magnetite and carbonate through microbial iron respiration (i.e., dissimilatory iron reduction, DIR). Iron and carbon isotope data of iron-rich metacarbonates from the ISB are similar to those of late Archean BIFs. The isotopic signatures of these metacarbonates are supportive of an early diagenetic origin despite metasomatic overprint, and preserve evidence for microbial iron catabolism at ~3.8 Ga, within the oldest recognized sedimentary rocks on Earth.

  14. Mechanistic and regulatory aspects of intestinal iron absorption.

    PubMed

    Gulec, Sukru; Anderson, Gregory J; Collins, James F

    2014-08-15

    Iron is an essential trace mineral that plays a number of important physiological roles in humans, including oxygen transport, energy metabolism, and neurotransmitter synthesis. Iron absorption by the proximal small bowel is a critical checkpoint in the maintenance of whole-body iron levels since, unlike most other essential nutrients, no regulated excretory systems exist for iron in humans. Maintaining proper iron levels is critical to avoid the adverse physiological consequences of either low or high tissue iron concentrations, as commonly occurs in iron-deficiency anemia and hereditary hemochromatosis, respectively. Exquisite regulatory mechanisms have thus evolved to modulate how much iron is acquired from the diet. Systemic sensing of iron levels is accomplished by a network of molecules that regulate transcription of the HAMP gene in hepatocytes, thus modulating levels of the serum-borne, iron-regulatory hormone hepcidin. Hepcidin decreases intestinal iron absorption by binding to the iron exporter ferroportin 1 on the basolateral surface of duodenal enterocytes, causing its internalization and degradation. Mucosal regulation of iron transport also occurs during low-iron states, via transcriptional (by hypoxia-inducible factor 2?) and posttranscriptional (by the iron-sensing iron-regulatory protein/iron-responsive element system) mechanisms. Recent studies demonstrated that these regulatory loops function in tandem to control expression or activity of key modulators of iron homeostasis. In health, body iron levels are maintained at appropriate levels; however, in several inherited disorders and in other pathophysiological states, iron sensing is perturbed and intestinal iron absorption is dysregulated. The iron-related phenotypes of these diseases exemplify the necessity of precisely regulating iron absorption to meet body demands. PMID:24994858

  15. Estimation of iron requirements for women by numerical analysis of population-based data from the National Health and Nutrition Surveys of Japan 2003-2007.

    PubMed

    Yokoi, Katsuhiko

    2014-10-01

    Iron requirements were estimated from the results of the National Health and Nutrition Surveys of Japan 2003-2007 using the numerical analysis of requirements based on an integral equation. The numerical analysis used population-based data on iron nutriture, the prevalence of inadequate iron status, and the distribution of iron intakes. The cutoff value for inadequate iron status was defined as a serum ferritin concentration <30ng/mL. Iron intakes and menstrual blood losses followed a log-normal distribution and published values were corrected accordingly to calculate usual values. For women aged 18-29 years old, the median of the estimated median iron requirement (corresponding to the estimated average requirement by using the terminology of the dietary reference intakes) was 7.59mg (range, 6.86-8.11). The median of the estimated usual iron intake covering the needs of women with 80mL per cycle of menstrual blood loss was 11.27mg (range, 10.16-12.00), and the median of the usual iron intake covering the needs of 97.7% of women was 13.93mg (range, 12.55-14.81). For women aged 30-49 years old, the corresponding figures were 8.13mg (range, 7.96-8.69), 11.95mg (range, 11.72-12.77), and 14.71mg (range, 14.44-15.72). PMID:25213680

  16. A heme export protein is required for red blood cell differentiation and iron homeostasis.

    PubMed

    Keel, Siobán B; Doty, Raymond T; Yang, Zhantao; Quigley, John G; Chen, Jing; Knoblaugh, Sue; Kingsley, Paul D; De Domenico, Ivana; Vaughn, Michael B; Kaplan, Jerry; Palis, James; Abkowitz, Janis L

    2008-02-01

    Hemoproteins are critical for the function and integrity of aerobic cells. However, free heme is toxic. Therefore, cells must balance heme synthesis with its use. We previously demonstrated that the feline leukemia virus, subgroup C, receptor (FLVCR) exports cytoplasmic heme. Here, we show that FLVCR-null mice lack definitive erythropoiesis, have craniofacial and limb deformities resembling those of patients with Diamond-Blackfan anemia, and die in midgestation. Mice with FLVCR that is deleted neonatally develop a severe macrocytic anemia with proerythroblast maturation arrest, which suggests that erythroid precursors export excess heme to ensure survival. We further demonstrate that FLVCR mediates heme export from macrophages that ingest senescent red cells and regulates hepatic iron. Thus, the trafficking of heme, and not just elemental iron, facilitates erythropoiesis and systemic iron balance. PMID:18258918

  17. Iron and Malaria Interactions: Research Needs From Basic Science to Global Policy12

    PubMed Central

    Cox, Sharon E.

    2012-01-01

    The resurgence in interest and concern regarding the potentially malign interactions between iron administration and malaria infections, especially in young children and pregnant women, has generated a research agenda that is both broad and deep. This paper highlights some of the key questions under 5 headings: basic science; clinical science and epidemiology; technological developments; country level planning; and global policy. At a time of unparalleled progress in basic science, which is illuminating the mechanisms by which iron interacts with infectious organisms, it is concluded that there are good medium-term prospects for achieving policy breakthroughs based on a secure foundation of disease-nutrient interactions. However, it is also stressed that there is much that can be done in the interim, especially in relation to health systems and implementation research that can empower systems to integrate iron interventions with programs for malaria prevention, surveillance, and treatment. PMID:22797996

  18. Dysregulation of cellular iron metabolism in Friedreich ataxia: from primary iron-sulfur cluster deficit to mitochondrial iron accumulation

    PubMed Central

    Martelli, Alain; Puccio, Hélène

    2014-01-01

    Friedreich ataxia (FRDA) is the most common recessive ataxia in the Caucasian population and is characterized by a mixed spinocerebellar and sensory ataxia frequently associating cardiomyopathy. The disease results from decreased expression of the FXN gene coding for the mitochondrial protein frataxin. Early histological and biochemical study of the pathophysiology in patient's samples revealed that dysregulation of iron metabolism is a key feature of the disease, mainly characterized by mitochondrial iron accumulation and by decreased activity of iron-sulfur cluster enzymes. In the recent past years, considerable progress in understanding the function of frataxin has been provided through cellular and biochemical approaches, pointing to the primary role of frataxin in iron-sulfur cluster biogenesis. However, why and how the impact of frataxin deficiency on this essential biosynthetic pathway leads to mitochondrial iron accumulation is still poorly understood. Herein, we review data on both the primary function of frataxin and the nature of the iron metabolism dysregulation in FRDA. To date, the pathophysiological implication of the mitochondrial iron overload in FRDA remains to be clarified. PMID:24917819

  19. Is early-life iron exposure critical in neurodegeneration?

    PubMed

    Hare, Dominic J; Arora, Manish; Jenkins, Nicole L; Finkelstein, David I; Doble, Philip A; Bush, Ashley I

    2015-09-01

    The effects of iron deficiency are well documented, but relatively little is known about the long-term implications of iron overload during development. High levels of redox-active iron in the brain have been associated with neurodegenerative disorders, most notably Parkinson disease, yet a gradual increase in brain iron seems to be a feature of normal ageing. Increased brain iron levels might result from intake of infant formula that is excessively fortified with iron, thereby altering the trajectory of brain iron uptake and amplifying the risk of iron-associated neurodegeneration in later life. In this Perspectives article, we discuss the potential long-term implications of excessive iron intake in early life, propose the analysis of iron deposits in teeth as a method for retrospective determination of iron exposure during critical developmental windows, and call for evidence-based optimization of the chemical composition of infant dietary supplements. PMID:26100754

  20. Daily oral iron supplementation during pregnancy

    PubMed Central

    Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Dowswell, Therese; Viteri, Fernando E

    2014-01-01

    Background Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it may also improve other maternal and birth outcomes. Objectives To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (2 July 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (2 July 2012) and contacted relevant organisations for the identification of ongoing and unpublished studies. Selection criteria Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy. Data collection and analysis We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. Main results We included 60 trials. Forty-three trials, involving more than 27,402 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo. Overall, women taking iron supplements were less likely to have low birthweight newborns (below 2500 g) compared with controls (8.4% versus 10.2%, average risk ratio (RR) 0.81; 95% confidence interval (CI) 0.68 to 0.97, 11 trials, 8480 women) and mean birthweight was 30.81 g greater for those infants whose mothers received iron during pregnancy (average mean difference (MD) 30.81; 95% CI 5.94 to 55.68, 14 trials, 9385 women). Preventive iron supplementation reduced the risk of maternal anaemia at term by 70% (RR 0.30; 95% CI 0.19 to 0.46, 14 trials, 2199 women) and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women). Although the difference between groups did not reach statistical significance, women who received iron supplements were more likely than controls to report side effects (25.3% versus 9.91%) (RR 2.36; 95% CI 0.96 to 5.82, 11 trials, 4418 women), particularly at doses 60 mg of elemental iron or higher. Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130g/L during pregnancy and at term. Twenty-three studies were conducted in countries that in 2011 had some malaria risk in parts of the country. In some of these countries/territories, malaria is present only in certain areas or up to a particular altitude. Only two of these reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%. Authors’ conclusions Prenatal supplementation with daily iron are effective to reduce the risk of low birthweight, and to prevent maternal anaemia and iron deficiency in pregnancy. Associated maternal side effects and particularly high Hb concentrations during pregnancy at currently used doses suggest the need to update recommendations on doses and regimens for routine iron supplementation. PMID:23235616

  1. Intravenous iron therapy: how far have we come?

    PubMed Central

    Cançado, Rodolfo Delfini; Muñoz, Manuel

    2011-01-01

    Oral iron supplementation is usually the first choice for the treatment of iron deficiency anemia (IDA) because of its effectiveness and low cost. But unfortunately in many iron deficient conditions, oral iron is a less than the ideal treatment mainly because of adverse events related to the gastrointestinal tract as well as the long course required to treat anemia and replenish body iron stores. The first iron product for intravenous use was high-molecular-weight iron dextran. However, dextran-containing intravenous iron preparations are associated with an elevated risk of anaphylactic reactions, which made physicians reluctant to prescribe intravenous iron in the treatment of iron deficiency anemia for many years. In 1999 and 2001, two new intravenous iron preparations (ferric gluconate and iron sucrose) were introduced into the market as safer alternatives to iron dextran. Over the last five years, three new intravenous iron dextran-free preparations have been developed and have better safety profiles than the more traditional intravenous compounds, as none require test doses and all these products are promising in respect to a more rapid replacement of body iron stores (15-60 minutes/infusion) as they can be given at higher doses (from 500 mg to more than 1000 mg/infusion). The purpose of this review is to discuss some pertinent issues in relation to the history, pharmacology, administration, efficacy, safety profile and toxicity of intravenous iron for the treatment of iron deficiency anemia. PMID:23049364

  2. Storage iron exchange in the rat as affected by deferoxamine

    SciTech Connect

    Kim, B.K.; Huebers, H.; Pippard, M.J.; Finch, C.A.

    1985-04-01

    The initial tissue localization and redistribution of radioactive iron injected intravenously into the rat as ferritin, chondroitin sulfate, and nonviable red cells was determined. Ferritin iron, initially localized in the hepatocyte, showed minimal redistribution over 24 hours in the normal animal. This may be compared with the active release of iron from the reticuloendothelial cell after the intravenous injection of nonviable red cells and chondroitin sulfate iron. All forms of iron were actively mobilized in iron-deficient animals. The effect of chelation of iron by deferoxamine (DFO) on the redistribution pattern over 4 to 6 hours was determined in iron-deficient, normal, iron-loaded, and phenylhydrazine-treated rats to evaluate the effect of iron stores and erythropoiesis. Use of DFO resulted in extensive chelation of radioactive iron within the hepatocyte and greatly reduced the amount of hepatocyte iron available for erythropoiesis. Very little chelation of reticuloendothelial cell-processed iron occurred, and there was little decrease in its utilization for red cell production. Total urinary chelate iron was independent of erythropoiesis but varied in parallel with the iron load of the animal. These studies suggest that DFO does not act on the reticuloendothelial cell but does have at least two sites of action, both of which relate to total storage iron. One involves hepatocyte stores with excretion into the intestinal tract. The other, possibly located at the hepatocyte membrane, results in urinary iron excretion.

  3. Liver toxicity of thioacetamide is increased by hepatocellular iron overload.

    PubMed

    Ackerman, Zvi; Pappo, Orit; Link, Gabriela; Glazer, Maya; Grozovski, Maria

    2015-02-01

    An increase in hepatic iron concentration might exacerbate liver injury. However, it is unknown whether hepatic iron overload may exacerbate acute liver injury from various toxins. Therefore, we evaluated how manipulations to increase hepatic iron concentration affected the extent of acute liver injury from thioacetamide. In this study, we used rats with either "normal" or increased hepatic iron concentration. Iron overload was induced by either providing excess iron in the diet or by injecting iron subcutaneously. Both routes of providing excess iron induced an increase in hepatic iron overload. Meanwhile, the subcutaneous route induced both hepatocellular and sinusoidal cell iron deposition; the oral route induced lesser degree of hepatic iron concentration and only hepatocellular iron overload. Thioacetamide administration to the rats with "normal" hepatic iron concentration induced hepatic cell necrosis and apoptosis associated with a remarkable increase in serum aminotransaminases and depletion of hepatic glutathione and other antioxidative indices. Thioacetamide administration to the iron-overloaded rats exacerbated the extent of liver injury only in the rats orally induced with iron overload. In the rats subcutaneously induced with iron overload, the extent of liver injury from thioacetamide was not different from that observed in the rats with "normal" iron overload. It was concluded that the outcome of thioacetamide-induced acute liver injury may depend on both the level of hepatic iron concentration and on the cellular distribution of iron. While isolated hepatocellular iron overload may exacerbate thioacetamide-induced acute liver injury, a combined hepatocellular and sinusoidal cell iron deposition, even at high hepatic iron concentration, had no such an effect. PMID:25161090

  4. Iron overload diseases: the chemical speciation of non-heme iron deposits in iron loaded mammalian tissues

    NASA Astrophysics Data System (ADS)

    St. Pierre, T. G.; Chua-Anusorn, W.; Webb, J.; Macey, D. J.

    2000-07-01

    57Fe Mössbauer spectra of iron overloaded human spleen, rat spleen and rat liver tissue samples at 78 K were found to consist of a quadrupole doublet (major component) with magnetic sextet (minor component with fractional spectral area F s). The distributions of F s for spleen tissue from two different clinically identifiable groups (n = 7 and n = 12) of thalassemic patients were found to be significantly different. The value of F s for dietary-iron loaded rat liver was found to rise significantly with age/duration (up to 24 months) of iron loading.

  5. Using iron line reverberation and spectroscopy to distinguish Kerr and non-Kerr black holes

    E-print Network

    Jiachen Jiang; Cosimo Bambi; James F. Steiner

    2015-04-21

    The iron K$\\alpha$ line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates is produced by the illumination of a cold accretion disk by a hot corona. In this framework, the activation of a new flaring region in the hot corona imprints a time variation on the iron line spectrum. Future X-ray facilities with high time resolution and large effective areas may be able to measure the so-called 2-dimensional transfer function; that is, the iron line profile detected by a distant observer as a function of time in response to an instantaneous flare from the X-ray primary source. This work is a preliminary study to determine if and how such a technique can provide more information about the spacetime geometry around the compact object than the already possible measurements of the time-integrated iron line profile. Within our simplified model, we find that a measurement of iron line reverberation can improve constraints appreciably given a sufficiently strong signal, though that most of the information is present in the time-integrated spectrum. Our aim is to test the Kerr metric. We find that current X-ray facilities and data are unable to provide strong tests of the Kerr nature of supermassive black hole candidates. We consider an optimistic case of $10^5$ iron line photons from a next-generation data set. With such data, the reverberation model improves upon the spectral constraint by an order of magnitude.

  6. Regulation of systemic iron homeostasis: how the body responds to changes in iron demand.

    PubMed

    Anderson, Gregory J; Darshan, Deepak; Wilkins, Sarah J; Frazer, David M

    2007-06-01

    The iron that is required to meet the metabolic needs of cells and tissues is derived from the plasma. Plasma iron in turn reflects the release of iron from various body cells, principally the macrophages of the reticuloendothelial system, and the absorption of dietary iron by the proximal small intestine. This iron donation is highly regulated and the liver-derived peptide hepcidin has emerged as the key modulator of cellular iron export. Following its synthesis and secretion from the liver, circulating hepcidin reduces iron export into the plasma by binding to the iron efflux protein ferroportin1 on the surface of enterocytes, macrophages and other cell types and causing its internalization. The level of hepatic hepcidin expression is influenced by HFE, transferrin receptor 2 and hemojuvelin, and the signal transduction pathway(s) linking these proteins to hepcidin are only beginning to be revealed. Hemojuvelin has recently been shown to signal through the bone morphogenetic protein pathway, ultimately activating receptor SMAD/SMAD4 complexes to alter hepcidin transcription. Circulating differic transferrin has emerged as a possible upstream regulator of the liver-based hepcidin regulatory pathway. In addition to being regulated by body iron requirements, hepcidin expression can be modulated by pro-inflammatory cytokines such as interleukin-6. The continuing analysis of inherited disorders of iron metabolism combined with biochemical analysis of signal transduction pathways is essential to fully define this important regulatory system. PMID:17273818

  7. Intravenous Iron Therapy in Patients with Iron Deficiency Anemia: Dosing Considerations.

    PubMed

    Koch, Todd A; Myers, Jennifer; Goodnough, Lawrence Tim

    2015-01-01

    Objective. To provide clinicians with evidence-based guidance for iron therapy dosing in patients with iron deficiency anemia (IDA), we conducted a study examining the benefits of a higher cumulative dose of intravenous (IV) iron than what is typically administered. Methods. We first individually analyzed 5 clinical studies, averaging the total iron deficit across all patients utilizing a modified Ganzoni formula; we then similarly analyzed 2 larger clinical studies. For the second of the larger studies (Study 7), we also compared the efficacy and retreatment requirements of a cumulative dose of 1500?mg ferric carboxymaltose (FCM) to 1000?mg iron sucrose (IS). Results. The average iron deficit was calculated to be 1531?mg for patients in Studies 1-5 and 1392?mg for patients in Studies 6-7. The percentage of patients who were retreated with IV iron between Days 56 and 90 was significantly (p < 0.001) lower (5.6%) in the 1500?mg group, compared to the 1000?mg group (11.1%). Conclusions. Our data suggests that a total cumulative dose of 1000?mg of IV iron may be insufficient for iron repletion in a majority of patients with IDA and a dose of 1500?mg is closer to the actual iron deficit in these patients. PMID:26257955

  8. Intravenous Iron Therapy in Patients with Iron Deficiency Anemia: Dosing Considerations

    PubMed Central

    Koch, Todd A.; Myers, Jennifer; Goodnough, Lawrence Tim

    2015-01-01

    Objective. To provide clinicians with evidence-based guidance for iron therapy dosing in patients with iron deficiency anemia (IDA), we conducted a study examining the benefits of a higher cumulative dose of intravenous (IV) iron than what is typically administered. Methods. We first individually analyzed 5 clinical studies, averaging the total iron deficit across all patients utilizing a modified Ganzoni formula; we then similarly analyzed 2 larger clinical studies. For the second of the larger studies (Study 7), we also compared the efficacy and retreatment requirements of a cumulative dose of 1500?mg ferric carboxymaltose (FCM) to 1000?mg iron sucrose (IS). Results. The average iron deficit was calculated to be 1531?mg for patients in Studies 1–5 and 1392?mg for patients in Studies 6-7. The percentage of patients who were retreated with IV iron between Days 56 and 90 was significantly (p < 0.001) lower (5.6%) in the 1500?mg group, compared to the 1000?mg group (11.1%). Conclusions. Our data suggests that a total cumulative dose of 1000?mg of IV iron may be insufficient for iron repletion in a majority of patients with IDA and a dose of 1500?mg is closer to the actual iron deficit in these patients. PMID:26257955

  9. Iron Absorption from Two Milk Formulas Fortified with Iron Sulfate Stabilized with Maltodextrin and Citric Acid

    PubMed Central

    Pizarro, Fernando; Olivares, Manuel; Maciero, Eugenia; Krasnoff, Gustavo; Cócaro, Nicolas; Gaitan, Diego

    2015-01-01

    Background: Fortification of milk formulas with iron is a strategy widely used, but the absorption of non-heme iron is low. The purpose of this study was to measure the bioavailability of two iron fortified milk formulas designed to cover toddlers’ nutritional needs. These milks were fortified with iron sulfate stabilized with maltodextrin and citric acid. Methods: 15 women (33–47 years old) participated in study. They received on different days, after an overnight fast, 200 mL of Formula A; 200 mL of Formula B; 30 mL of a solution of iron and ascorbic acid as reference dose and 200 mL of full fat cow’s milk fortified with iron as ferrous sulfate. Milk formulas and reference dose were labeled with radioisotopes 59Fe or 55Fe, and the absorption of iron measured by erythrocyte incorporation of radioactive Fe. Results: The geometric mean iron absorption corrected to 40% of the reference dose was 20.6% for Formula A and 20.7% for Formula B, versus 7.5% of iron fortified cow’s milk (p < 0.001). The post hoc Sheffé indeed differences between the milk formulas and the cow’s milk (p < 0.001). Conclusion: Formulas A and B contain highly bioavailable iron, which contributes to covering toddlers’ requirements of this micronutrient. PMID:26529007

  10. Iron biofortification in rice by the introduction of multiple genes involved in iron nutrition.

    PubMed

    Masuda, Hiroshi; Ishimaru, Yasuhiro; Aung, May Sann; Kobayashi, Takanori; Kakei, Yusuke; Takahashi, Michiko; Higuchi, Kyoko; Nakanishi, Hiromi; Nishizawa, Naoko K

    2012-01-01

    To address the problem of iron-deficiency anemia, one of the most prevalent human micronutrient deficiencies globally, iron-biofortified rice was produced using three transgenic approaches: by enhancing iron storage in grains via expression of the iron storage protein ferritin using endosperm-specific promoters, enhancing iron translocation through overproduction of the natural metal chelator nicotianamine, and enhancing iron flux into the endosperm by means of iron(II)-nicotianamine transporter OsYSL2 expression under the control of an endosperm-specific promoter and sucrose transporter promoter. Our results indicate that the iron concentration in greenhouse-grown T(2) polished seeds was sixfold higher and that in paddy field-grown T(3) polished seeds was 4.4-fold higher than that in non-transgenic seeds, with no defect in yield. Moreover, the transgenic seeds accumulated zinc up to 1.6-times in the field. Our results demonstrate that introduction of multiple iron homeostasis genes is more effective for iron biofortification than the single introduction of individual genes. PMID:22848789

  11. Iron biofortification in rice by the introduction of multiple genes involved in iron nutrition

    PubMed Central

    Masuda, Hiroshi; Ishimaru, Yasuhiro; Aung, May Sann; Kobayashi, Takanori; Kakei, Yusuke; Takahashi, Michiko; Higuchi, Kyoko; Nakanishi, Hiromi; Nishizawa, Naoko K.

    2012-01-01

    To address the problem of iron-deficiency anemia, one of the most prevalent human micronutrient deficiencies globally, iron-biofortified rice was produced using three transgenic approaches: by enhancing iron storage in grains via expression of the iron storage protein ferritin using endosperm-specific promoters, enhancing iron translocation through overproduction of the natural metal chelator nicotianamine, and enhancing iron flux into the endosperm by means of iron(II)-nicotianamine transporter OsYSL2 expression under the control of an endosperm-specific promoter and sucrose transporter promoter. Our results indicate that the iron concentration in greenhouse-grown T2 polished seeds was sixfold higher and that in paddy field-grown T3 polished seeds was 4.4-fold higher than that in non-transgenic seeds, with no defect in yield. Moreover, the transgenic seeds accumulated zinc up to 1.6-times in the field. Our results demonstrate that introduction of multiple iron homeostasis genes is more effective for iron biofortification than the single introduction of individual genes. PMID:22848789

  12. KINETIC CONDENSATION AND EVAPORATION OF METALLIC IRON AND IMPLICATIONS FOR METALLIC IRON DUST FORMATION

    SciTech Connect

    Tachibana, Shogo; Nagahara, Hiroko; Ozawa, Kazuhito; Ikeda, Youhei; Nomura, Ryuichi; Tatsumi, Keisuke; Joh, Yui

    2011-07-20

    Metallic iron is one of the most abundant condensing materials in systems of solar abundance. Because metallic iron is responsible for the continuum opacity of dust particles, it has a large contribution to the thermal structure of circumstellar environments and hence to dust evolution itself. In order to understand the formation processes of metallic iron in circumstellar environments, condensation and evaporation kinetics of metallic iron were studied experimentally. Metallic iron condenses at the maximum rate with the condensation coefficient (a parameter ranging from 0 to 1 to represent kinetic hindrance for surface reaction) of unity under high supersaturation conditions, and evaporates nearly ideally (evaporation coefficient of unity) in vacuum. On the other hand, evaporation of metallic iron takes place with more kinetic hindrance in the presence of metallic iron vapor. It is also found that metallic iron atoms nucleate heterogeneously on Al{sub 2}O{sub 3}. Metallic iron does not necessarily condense homogeneously in circumstellar environments, but might condense through heterogeneous nucleation on pre-existing dust. Metallic iron formation proceeds with little kinetic hindrance for highly unequilibrated conditions, but the effects of kinetic hindrance may appear for evaporation and condensation occurring near equilibrium with a timescale of months to years in protoplanetary disks.

  13. Nicotianamine synthase overexpression positively modulates iron homeostasis-related genes in high iron rice

    PubMed Central

    Wang, Meng; Gruissem, Wilhelm; Bhullar, Navreet K.

    2013-01-01

    Nearly one-third of the world population, mostly women and children, suffer from iron malnutrition and its consequences, such as anemia or impaired mental development. Biofortification of rice, which is a staple crop for nearly half of the world's population, can significantly contribute in alleviating iron deficiency. NFP rice (transgenic rice expressing nicotianamine synthase, ferritin and phytase genes) has a more than six-fold increase in iron content in polished rice grains, resulting from the synergistic action of nicotianamine synthase (NAS) and ferritin transgenes. We investigated iron homeostasis in NFP plants by analyzing the expression of 28 endogenous rice genes known to be involved in the homeostasis of iron and other metals, in iron-deficient and iron-sufficient conditions. RNA was collected from different tissues (roots, flag leaves, grains) and at three developmental stages during grain filling. NFP plants showed increased sensitivity to iron-deficiency conditions and changes in the expression of endogenous genes involved in nicotianamine (NA) metabolism, in comparison to their non-transgenic siblings (NTS). Elevated transcript levels were detected in NFP plants for several iron transporters. In contrast, expression of OsYSL2, which encodes a member of yellow stripe like protein family, and a transporter of the NA-Fe(II) complex was reduced in NFP plants under low iron conditions, indicating that expression of OsYSL2 is regulated by the endogenous iron status. Expression of the transgenes did not significantly affect overall iron homeostasis in NFP plants, which establishes the engineered push-pull mechanism as a suitable strategy to increase rice endosperm iron content. PMID:23755054

  14. Iron therapy for the treatment of iron deficiency in chronic heart failure: intravenous or oral?

    PubMed

    McDonagh, Theresa; Macdougall, Iain C

    2015-03-01

    This article considers the use and modality of iron therapy to treat iron deficiency in patients with heart failure, an aspect of care which has received relatively little attention compared with the wider topic of anaemia management. Iron deficiency affects up to 50% of heart failure patients, and is associated with poor quality of life, impaired exercise tolerance, and mortality independent of haematopoietic effects in this patient population. The European Society of Cardiology Guidelines for heart failure 2012 recommend a diagnostic work-up for iron deficiency in patients with suspected heart failure. Iron absorption from oral iron preparations is generally poor, with slow and often inefficient iron repletion; moreover, up to 60% of patients experience gastrointestinal side effects. These problems may be exacerbated in heart failure due to decreased gastrointestinal absorption and poor compliance due to pill burden. Evidence for clinical benefits using oral iron is lacking. I.v. iron sucrose has consistently been shown to improve exercise capacity, cardiac function, symptom severity, and quality of life. Similar findings were observed recently for i.v. ferric carboxymaltose in patients with systolic heart failure and impaired LVEF in the double-blind, placebo-controlled FAIR-HF and CONFIRM-HF trials. I.v. iron therapy may be better tolerated than oral iron, although confirmation in longer clinical trials is awaited. Routine diagnosis and management of iron deficiency in patients with symptomatic heart failure regardless of anaemia status is advisable, and, based on current evidence, prompt intervention using i.v. iron therapy should now be considered. PMID:25639592

  15. Iron therapy for the treatment of iron deficiency in chronic heart failure: intravenous or oral?

    PubMed Central

    McDonagh, Theresa; Macdougall, Iain C

    2015-01-01

    This article considers the use and modality of iron therapy to treat iron deficiency in patients with heart failure, an aspect of care which has received relatively little attention compared with the wider topic of anaemia management. Iron deficiency affects up to 50% of heart failure patients, and is associated with poor quality of life, impaired exercise tolerance, and mortality independent of haematopoietic effects in this patient population. The European Society of Cardiology Guidelines for heart failure 2012 recommend a diagnostic work-up for iron deficiency in patients with suspected heart failure. Iron absorption from oral iron preparations is generally poor, with slow and often inefficient iron repletion; moreover, up to 60% of patients experience gastrointestinal side effects. These problems may be exacerbated in heart failure due to decreased gastrointestinal absorption and poor compliance due to pill burden. Evidence for clinical benefits using oral iron is lacking. I.v. iron sucrose has consistently been shown to improve exercise capacity, cardiac function, symptom severity, and quality of life. Similar findings were observed recently for i.v. ferric carboxymaltose in patients with systolic heart failure and impaired LVEF in the double-blind, placebo-controlled FAIR-HF and CONFIRM-HF trials. I.v. iron therapy may be better tolerated than oral iron, although confirmation in longer clinical trials is awaited. Routine diagnosis and management of iron deficiency in patients with symptomatic heart failure regardless of anaemia status is advisable, and, based on current evidence, prompt intervention using i.v. iron therapy should now be considered. PMID:25639592

  16. Genome and low-iron response of an oceanic diatom adapted to chronic iron limitation

    PubMed Central

    2012-01-01

    Background Biogeochemical elemental cycling is driven by primary production of biomass via phototrophic phytoplankton growth, with 40% of marine productivity being assigned to diatoms. Phytoplankton growth is widely limited by the availability of iron, an essential component of the photosynthetic apparatus. The oceanic diatom Thalassiosira oceanica shows a remarkable tolerance to low-iron conditions and was chosen as a model for deciphering the cellular response upon shortage of this essential micronutrient. Results The combined efforts in genomics, transcriptomics and proteomics reveal an unexpected metabolic flexibility in response to iron availability for T. oceanica CCMP1005. The complex response comprises cellular retrenchment as well as remodeling of bioenergetic pathways, where the abundance of iron-rich photosynthetic proteins is lowered, whereas iron-rich mitochondrial proteins are preserved. As a consequence of iron deprivation, the photosynthetic machinery undergoes a remodeling to adjust the light energy utilization with the overall decrease in photosynthetic electron transfer complexes. Conclusions Beneficial adaptations to low-iron environments include strategies to lower the cellular iron requirements and to enhance iron uptake. A novel contribution enhancing iron economy of phototrophic growth is observed with the iron-regulated substitution of three metal-containing fructose-bisphosphate aldolases involved in metabolic conversion of carbohydrates for enzymes that do not contain metals. Further, our data identify candidate components of a high-affinity iron-uptake system, with several of the involved genes and domains originating from duplication events. A high genomic plasticity, as seen from the fraction of genes acquired through horizontal gene transfer, provides the platform for these complex adaptations to a low-iron world. PMID:22835381

  17. Management strategies of iron accumulation in a captive population of black rhinoceroses (Diceros bicornis minor).

    PubMed

    Mylniczenko, Natalie D; Sullivan, Kathleen E; Corcoran, Michelle E; Fleming, Gregory J; Valdes, Eduardo V

    2012-09-01

    During routine health screens for black rhinoceroses (Diceros bicornis minor) in a captive setting, serum iron and ferritin were analyzed as well as total iron binding capacity and total iron saturation. Trends for ferritin and percent iron saturation showed steady increases since 2003 in four of four animals (three males; one female) with two animals (one male; one female) consistently showing higher elevations over conspecifics. The historical diet had been comprised of a commercial or in-house complete pelleted feed; several species of fresh browse, Bermuda grass, alfalfa and timothy hays, as well as enrichment and training items (apples, carrots, sweet potatoes, and a small amount of leafy greens and vegetables). In 2009, one of the three male rhinoceroses showed a threefold increase in ferritin and concurrently exhibited clinical signs of lethargy, decreased appetite, and disinterest in training. The lone female showed a twofold increase; she also became reproductively acyclic in the prior year. The male was immobilized for examination and phlebotomy. During the same time period, a new version of the complete pelleted feed, with a reduced amount of iron, was introduced. Subsequent to the diet change, the male's ferritin levels have consistently declined, and the female started cycling again. Even with these corrective steps to reduce iron levels, levels of iron saturation remained high, and ferritin levels were still above 1,500 ng/ml. Therapeutic phlebotomy was instituted via a rigorous training program that allowed phlebotomies over a 30-min time frame. This was possible because of a long-term training program for the animals, consistent training personnel, routine collection of samples on a monthly basis, and general comfort level of the animals in the restraint chute. The results of this integrated approach showed some significant improvements and an overall positive impact on the animals. PMID:23156710

  18. Energy assessments in iron foundries

    SciTech Connect

    Meffert, W.A.

    1999-08-01

    The US metal-casting industry has undergone two decades of consolidation and overseas competition that has left it leaner, smarter, and more competitive. Energy use in particular has received a lot of attention because it is one of the top costs of manufacturing. However, the industry still has room for significant energy savings by taking advantage of proven strategies and technology. Many of these strategies are low and no-cost measures. An assessment of a large, ductile iron foundry performed by the Georgia Tech Industrial Assessment Center (IAC) has identified key strategies to decrease energy costs. The foundry currently practices some of the strategies. Other strategies were discovered and developed by the team. This article presents a rational approach to targeting energy costs and outlines the key strategies. Both successes and failures are detailed in the hopes that future assessment teams will be able to build on the efforts described.

  19. Shock waves in polycrystalline iron.

    PubMed

    Kadau, Kai; Germann, Timothy C; Lomdahl, Peter S; Albers, Robert C; Wark, Justin S; Higginbotham, Andrew; Holian, Brad Lee

    2007-03-30

    The propagation of shock waves through polycrystalline iron is explored by large-scale atomistic simulations. For large enough shock strengths the passage of the wave causes the body-centered-cubic phase to transform into a close-packed phase with most structure being isotropic hexagonal-close-packed (hcp) and, depending on shock strength and grain orientation, some fraction of face-centered-cubic (fcc) structure. The simulated shock Hugoniot is compared to experiments. By calculating the extended x-ray absorption fine structure (EXAFS) directly from the atomic configurations, a comparison to experimental EXAFS measurements of nanosecond-laser shocks shows that the experimental data is consistent with such a phase transformation. However, the atomistically simulated EXAFS spectra also show that an experimental distinction between the hcp or fcc phase is not possible based on the spectra alone. PMID:17501216

  20. Iron deficiency anemia in pregnancy.

    PubMed

    Di Renzo, Gian Carlo; Spano, Filippo; Giardina, Irene; Brillo, Eleonora; Clerici, Graziano; Roura, Luis Cabero

    2015-11-01

    Anemia is the most frequent derailment of physiology in the world throughout the life of a woman. It is a serious condition in countries that are industrialized and in countries with poor resources. The main purpose of this manuscript is to give the right concern of anemia in pregnancy. The most common causes of anemia are poor nutrition, iron deficiencies, micronutrients deficiencies including folic acid, vitamin A and vitamin B12, diseases like malaria, hookworm infestation and schistosomiasis, HIV infection and genetically inherited hemoglobinopathies such as thalassemia. Depending on the severity and duration of anemia and the stage of gestation, there could be different adverse effects including low birth weight and preterm delivery. Treatment of mild anemia prevents more severe forms of anemia, strictly associated with increased risk of fetal-maternal mortality and morbidity. PMID:26472066

  1. Synthesis and characterization of platinum decorated iron oxide nanoparticles for biomedical applications

    NASA Astrophysics Data System (ADS)

    Palchoudhury, Soubantika

    This dissertation focuses on the development of a bifunctional nanoparticle system that can potentially offer simultaneous imaging and therapy in the future. Recently, small platinum (Pt) nanoparticles (< 5 nm) have shown great potential in therapeutic applications, such as DNA dissociation, radiation therapy, and oxidative stress treatment. Therefore, the small Pt nanoparticles of size comparable to DNA grooves are chosen as potential therapeutic components in this research. However, such small sized Pt nanoparticles tends to aggregate, and are difficult to target. Therefore, this research reports the synthesis, characterization, and DNA interaction of small Pt decorated iron oxide nanoparticles. The iron oxide carriers provide stability to the small Pt nanoparticles, and can potentially serve as MRI contrast agents. The hypothesis of this research is that the Pt nanoparticles supported on iron oxide nanoparticle surfaces can effectively interact with DNA molecules similar to the free Pt nanoparticles. A reproducible synthetic technique was first developed to prepare iron oxide nanoparticles with excellent size control and narrow size distribution. Subsequently, two different approaches were utilized to produce multiple small Pt nanoparticle attached iron oxide nanoparticles. The first route involved attachment of Pt nanoparticles onto iron oxide seeds of various shapes in an organic solvent, followed by an aqueous phase transfer. Here, the shape of the nanoparticles was controlled to facilitate heterogeneous nucleation of Pt nanoparticles. The protective biocompatible polymer coating (polyacrylic acid) in this method could prevent interaction of the Pt nanoparticles with undesirable biomolecules. Several non-spherical iron oxide nanoparticles were explored, including whiskers, worms, plates, and flowers. In the second method, an aqueous phase ligand exchange process was performed first, prior to the deposition of multiple Pt nanoparticles. This facile method provided more accessibility of the Pt nanoparticles for DNA interactions. The DNA interaction of these nanoparticles was investigated using gel electrophoresis, electron microscopy, dynamic light scattering, and atomic absorption spectroscopy. By comparing with control DNA, we suggested that two possible interactions between DNA and Pt-iron oxide nanoparticles were present: (1) DNA molecules directly linked to the Pt-iron oxide nanoparticles, and (2) DNA molecules de-attached the Pt nanoparticles from the iron oxide support. This reported nanodrug system could potentially open up new possibilities in the design of therapeutic agents using multifunctional nanoparticles. Future efforts are to investigate the in vivo characteristics of this integrated nanostructure.

  2. Co-Production of Electricity and Hydrogen Using a Novel Iron-based Catalyst

    SciTech Connect

    Hilaly, Ahmad; Georgas, Adam; Leboreiro, Jose; Arora, Salil; Head, Megann; Trembly, Jason; Turk, Brian; Gupta, Raghubir

    2011-09-30

    The primary objective of this project was to develop a hydrogen production technology for gasification applications based on a circulating fluid-bed reactor and an attrition resistant iron catalyst. The work towards achieving this objective consisted of three key activities: • Development of an iron-based catalyst suitable for a circulating fluid-bed reactor • Design, construction, and operation of a bench-scale circulating fluid-bed reactor system for hydrogen production • Techno-economic analysis of the steam-iron and the pressure swing adsorption hydrogen production processes. This report describes the work completed in each of these activities during this project. The catalyst development and testing program prepared and iron-based catalysts using different support and promoters to identify catalysts that had sufficient activity for cyclic reduction with syngas and steam oxidation and attrition resistance to enable use in a circulating fluid-bed reactor system. The best performing catalyst from this catalyst development program was produced by a commercial catalyst toll manufacturer to support the bench-scale testing activities. The reactor testing systems used during material development evaluated catalysts in a single fluid-bed reactor by cycling between reduction with syngas and oxidation with steam. The prototype SIP reactor system (PSRS) consisted of two circulating fluid-bed reactors with the iron catalyst being transferred between the two reactors. This design enabled demonstration of the technical feasibility of the combination of the circulating fluid-bed reactor system and the iron-based catalyst for commercial hydrogen production. The specific activities associated with this bench-scale circulating fluid-bed reactor systems that were completed in this project included design, construction, commissioning, and operation. The experimental portion of this project focused on technical demonstration of the performance of an iron-based catalyst and a circulating fluid-bed reactor system for hydrogen production. Although a technology can be technically feasible, successful commercial deployment also requires that a technology offer an economic advantage over existing commercial technologies. To effective estimate the economics of this steam-iron process, a techno-economic analysis of this steam iron process and a commercial pressure swing adsorption process were completed. The results from this analysis described in this report show the economic potential of the steam iron process for integration with a gasification plant for coproduction of hydrogen and electricity.

  3. Indium Sorption to Iron Oxides

    NASA Astrophysics Data System (ADS)

    White, S. J.; Sacco, S. A.; Hemond, H.; Hussain, F. A.; Runkel, R. L.; Walton-Day, K. E.; Kimball, B. A.; Shine, J. P.

    2014-12-01

    Indium is an increasingly important metal in semiconductors and electronics, and its use is growing rapidly as a semiconductive coating (as indium tin oxide) for liquid crystal displays (LCDs) and flat panel displays. It also has uses in important energy technologies such as light emitting diodes (LEDs) and photovoltaic cells. Despite its rapid increase in use, very little is known about the environmental behavior of indium, and concerns are being raised over the potential health effects of this emerging metal contaminant. One source of indium to the environment is acid mine drainage from the mining of lead, zinc, and copper sulfides. In our previous studies of a stream in Colorado influenced by acid mine drainage from lead and zinc mining activities, indium concentrations were found to be 10,000 times those found in uncontaminated rivers. However, the speciation and mobility of indium could not be reliably modeled because sorption constants to environmental sorbents have not been determined. In this study, we generate sorption constants for indium to ferrihydrite in the laboratory over a range of pHs, sorbent to sorbate ratios, and ionic strengths. Ferrihydrite is one of the most important sorbents in natural systems, and sorption to amorphous iron oxides such as ferrihydrite is thought to be one of the main removal mechanisms of metals from the dissolved phase in aqueous environments. Because of its relatively low solubility, we also find that indium hydroxide precipitation can dominate indium's partitioning at micromolar concentrations of indium. This precipitation may be important in describing indium's behavior in our study stream in Colorado, where modeling sorption to iron-oxides does not explain the complete removal of indium from the dissolved phase when the pH of the system is artificially raised to above 8. This study contributes much-needed data about indium's aqueous behavior, in order to better understand its fate, transport, and impacts in the environment.

  4. Microbial Biosignatures in High Iron Thermal Springs

    NASA Astrophysics Data System (ADS)

    Parenteau, M. N.; Embaye, T.; Jahnke, L. L.; Cady, S. L.

    2003-12-01

    The emerging anoxic source waters at Chocolate Pots hot springs in Yellowstone National Park contain 2.6 to 11.2 mg/L Fe(II) and are 51-54° C and pH 5.5-6.0. These waters flow down the accumulating iron deposits and over three major phototrophic mat communities: Synechococcus/Chloroflexus at 51-54° C, Pseudanabaena at 51-54° C, and a narrow Oscillatoria at 36-45° C. We are assessing the contribution of the phototrophs to biosignature formation in this high iron system. These biosignatures can be used to assess the biological contribution to ancient iron deposits on Earth (e.g. Precambrian Banded Iron Formations) and, potentially, to those found on Mars. Most studies to date have focused on chemotrophic iron-oxidizing communities; however, recent research has demonstrated that phototrophs have a significant physiological impact on these iron thermal springs (Pierson et al. 1999, Pierson and Parenteau 2000, and Trouwborst et al., 2003). We completed a survey of the microfossils, biominerals, biofabrics, and lipid biomarkers in the phototrophic mats and stromatolitic iron deposits using scanning and transmission electron microscopy (SEM and TEM), energy dispersive spectrometry (EDS), powder X-ray diffraction (XRD), and gas chromatography-mass spectroscopy (GC-MS). The Synechococcus/Chloroflexus mat was heavily encrusted with iron silicates while the narrow Oscillatoria mat was encrusted primarily with iron oxides. Encrustation of the cells increased with depth in the mats. Amorphous 2-line ferrihydrite is the primary precipitate in the spring and the only iron oxide mineral associated with the mats. Goethite, hematite, and siderite were detected in dry sediment samples on the face of the main iron deposit. Analysis of polar lipid fatty acid methyl esters (FAME) generated a suite of lipid biomarkers. The Synechococcus/Chloroflexus mat contained two mono-unsaturated isomers of n-C18:1 with smaller amounts of polyunsaturated n-C18:2, characteristic of cyanobacteria. The mat also contained abundant n,n-wax esters of C32 to C37, characteristic of Chloroflexus. 10-Methyl-C16 was also detected, indicative of sulfate reducing bacteria (SRB). The narrow Oscillatoria mat was dominated by the aforementioned cyanobacterial biomarkers as well as iso-C17:1, a biomarker for some groups of SRB. Unusual dimethyl fatty acids were also detected. The goal of this research is to provide an initial dataset that will illustrate the maximum amount of paleobiological and paleoenvironmental information expected to form in these types of iron deposits. Insights from our research may help elucidate the role of phototrophs in the deposition of BIFs on Earth, and may assist in the search for evidence of fossilized microbial life in iron deposits on Mars. Pierson, B.K., M.N. Parenteau, and B.M. Griffin, Phototrophs in high-iron-concentration microbial mats: Ecology of phototrophs in an iron-depositing hot spring, Appl. Environ. Microbiol., 65, 5474-5483, 1999. Pierson, B.K., and M.N. Parenteau, Phototrophs in high iron microbial mats: Microstructure of mats in iron-depositing hot springs, FEMS Microbiology Ecology 32, 181-196, 2000. Trouwborst, R., G. Koch, G. Luther, and B.K. Pierson, Photosynthesis and iron in hot spring microbial mats (abstract), NAI General Meeting, Astrobiology 2(4), 206, 2003.

  5. Iron, oxygen, and the pulmonary circulation

    PubMed Central

    2015-01-01

    The human pulmonary vasculature vasoconstricts in response to a reduction in alveolar oxygen tension, a phenomenon termed hypoxic pulmonary vasoconstriction (HPV). This review describes the time course of this behavior, which occurs in distinct phases, and then explores the importance for HPV of the hypoxia-inducible factor (HIF) pathway. Next, the HIF-hydroxylase enzymes that act as molecular oxygen sensors within the HIF pathway are discussed. These enzymes are particularly sensitive to intracellular iron availability, which confers iron-sensing properties on the HIF pathway. Human studies of iron chelation and supplementation are then reviewed. These demonstrate that the iron sensitivity of the HIF pathway evident from in vitro experiments is relevant to human pulmonary vascular physiology. Next, the importance of iron status in high-altitude illness and chronic cardiopulmonary disease is explored, and the therapeutic potential of intravenous iron discussed. The review concludes by highlighting some further complexities that arise from interactions between the HIF pathway and other intracellular iron-sensing mechanisms. PMID:26066825

  6. Iron cycling at corroding carbon steel surfaces.

    PubMed

    Lee, Jason S; McBeth, Joyce M; Ray, Richard I; Little, Brenda J; Emerson, David

    2013-01-01

    Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media. PMID:24093730

  7. Platinum attachments on iron oxide nanoparticle surfaces

    NASA Astrophysics Data System (ADS)

    Palchoudhury, Soubantika; Xu, Yaolin; An, Wei; Turner, C. Heath; Bao, Yuping

    2010-05-01

    Platinum nanoparticles supported on metal oxide surfaces have shown great potential as heterogeneous catalysts to accelerate electrochemical processes, such as the oxygen reduction reaction in fuel cells. Recently, the use of magnetic supports has become a promising research topic for easy separation and recovery of catalysts using magnets, such as Pt nanoparticles supported on iron oxide nanoparticles. The attachment of Pt on iron oxide nanoparticles is limited by the wetting ability of the Pt (metal) on ceramic surfaces. A study of Pt nanoparticle attachment on iron oxide nanoparticle surfaces in an organic solvent is reported, which addresses the factors that promote or inhibit such attachment. It was discovered that the Pt attachment strongly depends on the capping molecules of the iron oxide seeds and the reaction temperature. For example, the attachment of Pt nanoparticles on oleic acid coated iron oxide nanoparticles was very challenging, because of the strong binding between the carboxylic groups and iron oxide surfaces. In contrast, when nanoparticles are coated with oleic acid/tri-n-octylphosphine oxide or oleic acid/oleylamine, a significant increase in Pt attachment was observed. Electronic structure calculations were then applied to estimate the binding energies between the capping molecules and iron ions, and the modeling results strongly support the experimental observations.

  8. Platinum Attachments on Iron Oxide Nanoparticle Surfaces

    SciTech Connect

    Palchoudhury, Soubantika; Xu, Yaolin; An, Wei; Turner, C. H.; Bao, Yuping

    2010-04-30

    Platinum nanoparticles supported on metal oxide surfaces have shown great potential as heterogeneous catalysts to accelerate electrochemical processes, such as the oxygen reduction reaction in fuel cells. Recently, the use of magnetic supports has become a promising research topic for easy separation and recovery of catalysts using magnets, such as Pt nanoparticles supported on iron oxide nanoparticles. The attachment of Pt on iron oxide nanoparticles is limited by the wetting ability of the Pt (metal) on ceramic surfaces. A study of Pt nanoparticle attachment on iron oxide nanoparticle surfaces in an organic solvent is reported, which addresses the factors that promote or inhibit such attachment. It was discovered that the Pt attachment strongly depends on the capping molecules of the iron oxide seeds and the reaction temperature. For example, the attachment of Pt nanoparticles on oleic acid coated iron oxide nanoparticles was very challenging, because of the strong binding between the carboxylic groups and iron oxide surfaces. In contrast, when nanoparticles are coated with oleic acid/tri-n-octylphosphine oxide or oleic acid/oleylamine, a significant increase in Pt attachment was observed. Electronic structure calculations were then applied to estimate the binding energies between the capping molecules and iron ions, and the modeling results strongly support the experimental observations.

  9. Deferitazole, a new orally active iron chelator.

    PubMed

    Hider, Robert C; Kong, Xiaole; Abbate, Vincenzo; Harland, Rachel; Conlon, Kelly; Luker, Tim

    2015-03-21

    Following a systematic search of desferrithiocin analogs, a polyether derivative, deferitazole (formerly FBS0701), has entered into phase 1 and 2 clinical trials with promising biological properties. However, until now, detailed physicochemical properties of this chelator have not been reported. The compound displays a high affinity and selectivity for iron(III) as demonstrated by the log??2 = 33.39 ± 0.03 and the pFe(3+) value of 22.3. Two equilibrating isomeric forms of the iron(III) complex exist under biological conditions. Deferitazole also binds the trivalent metals Al(III) and La(III) with high affinity; log??2 values, 26.68 and 21.55 respectively. The affinity of deferitazole for divalent cations is somewhat lower, with the exception of Cu(II) which possesses a log??2 value of 25.5; deferitazole scavenges iron from labile sources such as citrate and albumin with efficiencies comparable with those of other therapeutic iron chelators, including deferasirox, deferiprone and desferrioxamine. The Fe(III)(deferitazole)2 is stable under physiological conditions and does not redox cycle. The high affinity of deferitazole for iron(III) renders it unlikely that this chelator will lead to the redistribution of iron and consequently deferitazole shows considerable promise as a therapeutic iron(III) chelator. PMID:25687725

  10. Preparation of iron castings for enameling

    SciTech Connect

    Mironenko, V.V.; Naletov, A.S.; Paladich, V.V.

    1983-01-01

    The quality of enameling depends not only upon the composition of the enamel but also upon the structure, composition and properties of the metal being enameled. An increase in enameling quality and in the properties of enameled cast iron parts may be obtained by surface sheathing of cast iron parts with 08 low-carbon steel. The authors have investigated the conditions of formation of a strong metallic bond between 08 steel and molten cast iron and of obtaining a low-carbon layer on the surface of a sheathed casting on the side of the iron. On the basis of the experimental data, a nomogram was drawn making it possible to determine the production conditions of the process. The results of the investigation are being used as the basis of a new method of producing cast iron enameled fittings with a surface low-carbon layer. The method developed specifies the preparation of halves of a thin-walled hollow nonremovable core of 08 sheet steel, diffusion butt welding of the halves prepared, shot peening, placement of the cores in the sand mold and pouring of iron at 1430-1460/sup 0/C. Production tests of experimental housings for valves showed the effectiveness of the new method in comparison with the traditional. The strength of the cast iron was increased by 1.5 times and the soundness of the enamel coating by 4 times.

  11. Iron deficiency anemia in celiac disease

    PubMed Central

    Freeman, Hugh James

    2015-01-01

    Iron is an important micronutrient that may be depleted in celiac disease. Iron deficiency and anemia may complicate well-established celiac disease, but may also be the presenting clinical feature in the absence of diarrhea or weight loss. If iron deficiency anemia occurs, it should be thoroughly evaluated, even if celiac disease has been defined since other superimposed causes of iron deficiency anemia may be present. Most often, impaired duodenal mucosal uptake of iron is evident since surface absorptive area in the duodenum is reduced, in large part, because celiac disease is an immune-mediated disorder largely focused in the proximal small intestinal mucosa. Some studies have also suggested that blood loss may occur in celiac disease, sometimes from superimposed small intestinal disorders, including ulceration or neoplastic diseases, particularly lymphoma. In addition, other associated gastric or colonic disorders may be responsible for blood loss. Rarely, an immune-mediated hemolytic disorder with increased urine iron loss may occur that may respond to a gluten-free diet. Reduced expression of different regulatory proteins critical in iron uptake has also been defined in the presence and absence of anemia. Finally, other rare causes of microcytic anemia may occur in celiac disease, including a sideroblastic form of anemia reported to have responded to a gluten-free diet. PMID:26309349

  12. Iron cycling at corroding carbon steel surfaces

    PubMed Central

    Lee, Jason S.; McBeth, Joyce M.; Ray, Richard I.; Little, Brenda J.; Emerson, David

    2013-01-01

    Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with three culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media. PMID:24093730

  13. Iron requirements based upon iron absorption tests are poorly predicted by haematological indices in patients with inactive inflammatory bowel disease

    PubMed Central

    Lomer, Miranda CE; Cook, William B; Jan-Mohamed, Hamid Jan B; Hutchinson, Carol; Liu, Ding Yong; Hider, Robert C; Powell, Jonathan J

    2012-01-01

    Iron deficiency (ID) and iron deficiency anaemia (IDA) are common in patients with inflammatory bowel disease (IBD). Traditional clinical markers of iron status can be skewed in the presence of inflammation meaning that a patient’s iron status can be misinterpreted. Additionally, iron absorption is known to be down-regulated in patients with active IBD. However, whether this is the case for quiescent or mildly active disease has not been formally assessed. This study aimed to investigate the relationship between iron absorption, iron requirements and standard haematological indices in IBD patients without active disease. Twenty nine patients with quiescent or mildly active IBD and 28 control subjects undertook an iron absorption test which measured sequential rises in serum iron over four hours following ingestion of 200 mg ferrous sulphate. At baseline, serum iron, transferrin saturation, non-transferrin bound iron (NTBI), ferritin and soluble transferrin receptor were all measured. Thereafter (30-240 minutes) only serum iron and NTBI were measured. Iron absorption did not differ between the two groups (P=0.9; RM-ANOVA). In control subjects baseline haematological parameters predicted iron absorption (i.e. iron requirements) but this was not the case for patients with IBD. Iron absorption is normal in quiescent or mildly active IBD patients but standard haematological parameters do not accurately predict iron requirements. PMID:22152498

  14. Magnetic Susceptibility of Submicroscopic Metallic Iron Formation Through Laser Irradiation of Olivine

    NASA Astrophysics Data System (ADS)

    Markley, M. M.; Kletetschka, G.

    2014-12-01

    Surfaces of exposed solids change their integrity due to solar wind and micrometeorite impacts, resulting in significant modification of exposed mineral grains. Apart from the possibility of in-situ ice generation, initial iron rich composition allows for re-precipitation of iron. The importance of characterizing these SMFe (submicroscopic metallic iron) particles exists to better our interpretations in remote sensing of planetary surface minerals. For example, the presence of SMFe changes the spectral reflectance of silicate minerals in the visible (VIS) to near-infrared (NIR) wavelengths, and contributes to "space weathering": (1) SMFe darkens the overall reflectance, (2) steepens (or reddens) the spectral slope, and (3) decreases the contrast in the 1 µm band. Irradiating olivine samples with energies simulating micrometeorite impact energies revealed single domain (SD) and superparamagnetic (SPM) iron grains varying in size. All samples exhibit general VIS-NIR space weathering effects, but also magnetic anomalies in the immediate surface proximity and frequency dependent magnetic susceptibility changes due to the production of SMFe. Planetary minerals such as olivine produce more SMFe when micrometeorite impacts and/or solar wind irradiation increases. Magnetic textures found during the scanning of the laser irradiated samples reveal anomalies that are dominantly caused by metallic iron and are in superparamagnetic state while at room temperature. We observed an increased dispersion of these metallic anomalies when irradiation energy increased. Frequency dependent magnetic susceptibility measurements creates a data set that has potential to become a tool in remote detection of these surfaces by deep penetration radar incidence.

  15. High-temperature miscibility of iron and rock during terrestrial planet formation

    NASA Astrophysics Data System (ADS)

    Wahl, Sean M.; Militzer, Burkhard

    2015-01-01

    The accretion of a terrestrial body and differentiation of its silicate/oxide mantle from iron core provide abundant energy for heating its interior to temperatures much higher than the present day Earth. The consequences of differentiation on the structure and composition of planets are typically addressed considering only the interaction of molten iron with an immiscible 'rocky' phase. We demonstrate that mixing in a representative system of liquid or solid MgO and liquid iron to a single homogeneous liquid occurs at sufficiently low temperature to be present in the aftermath of a giant impact. Applying the thermodynamic integration technique to density functional theory molecular dynamics simulations, we determine the solvus closure temperature for the Fe-MgO system for pressures up to 400 GPa. Solvus closure occurs at ?4000 K at low pressure, and has a weak positive pressure dependence, such that its gradient with respect to depth is less steep than an adiabatic temperature profile. This predicts a new mode of core-mantle differentiation following the most energetic giant impacts, with exsolution of iron from the mixture beginning in the outer layers of the planet. We demonstrate that high-temperature equilibration results in delivery of nominally insoluble Mg-rich material to the early core. Since MgO is the least soluble major mantle component in iron at low temperatures, these results may represent an upper bound on temperature for mixing in terrestrial planets.

  16. Hepcidin/Ferritin Quotient Helps to Predict Spontaneous Recovery from Iron Loss following Blood Donation

    PubMed Central

    Lotfi, Ramin; Kroll, Christine; Plonné, Dietmar; Jahrsdörfer, Bernd; Schrezenmeier, Hubert

    2015-01-01

    Summary Background Iron supplementation is generally recommended for blood donors even though there are inter-individual differences in iron homeostasis. Methods Ferritin levels of repeat donors were compared with first-time donors, retrospectively. Prospectively, we tested 27 male repeat donors for the following parameters at the day of blood donation as well as 1, 3, 7, 10, and 56 days thereafter: ferritin, hepcidin, transferrin, transferrin receptor, hemoglobin, erythropoietin, reticulocytes, hemoglobin in reticulocyte, twisted gastrulation protein homolog 1, and growth differentiation factor-15. Results 56 days after blood donation, donors' average ferritin dropped to 55% (range 30-100%) compared to the initial value. Of all tested parameters hepcidin showed the highest and most significant changes beginning 1 day after donation and lasting for the whole period of 56 days. Along with ferritin, there was a high variation in hepcidin levels indicating inter-individual differences in hepcidin response to iron loss. Donors with a hepcidin/ferritin quotient < 0.3 regained 60% of their initial ferritin after 56 days, while those with a quotient ? 0.3 reached less than 50%. Conclusion As hepcidin appears to integrate erythropoietic and iron-loading signals, clinical measurement of hepcidin (together with the hepcidin-ferritin ratio) may become a useful indicator of erythropoiesis and iron kinetics.

  17. Hydrogen and Ferric Iron in Mars Materials

    NASA Technical Reports Server (NTRS)

    Dyar, Melinda D.

    2004-01-01

    Knowledge of oxygen and hydrogen fugacity is of paramount importance in constraining phase equilibria and crystallization processes of melts, as well as understanding the partitioning of elements between the cope and silicate portions of terrestrial planets. H and Fe(3+) must both be analyzed in order to reconstruct hydrogen and oxygen fugacities on Mars. To date, SIMS data have elucidated D/H and H contents of hydrous phases in SNC meteorites, but until now anhydrous martian minerals have not been systematically examined for trace hydrogen. Ferric iron has been quantified using XANES in many martian phases, but integrated studies of both Fe(3+) and H on the same spots are really needed to address the H budget. Finally, the effects of shock on both Fe(3+) and H in hydrous and anhydrous phases must be quantified. Thus, the overall goal of this research was to understand the oxygen and hydrogen fugacities under which martian samples crystallized. In this research one-year project, we approached this problem by 1) characterizing Fe(3+) and H contents of SNC meteorites using both bulk (Mossbauer spectroscopy and uranium extraction, respectively) and microscale (synchrotron micro-XANES and SIMS) methods; 2) relating Fe(3+) and H contents of martian minerals to their oxygen and hydrogen fugacities through analysis of experimentally equilibrated phases (for pyroxene) and through study of volcanic rocks in which the oxygen and hydrogen fugacities can be independently constrained (for feldspar); and 3) studying the effects of shock processes on Fe(3+) and H contents of the phases of interest. Results have been used to assess quantitatively the distribution of H and Fe(3+) among phases in the martian interior, which will better constrain the geodynamic processes of the interior, as well as the overall hydrogen and water budgets on Mars. There were no inventions funded by this research.

  18. Reductive Dissolution of Iron Oxides and Iron-Rich Clays Enhanced by Sulfate-Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Zhang, C. L.

    2003-12-01

    Iron oxides and iron-rich clays are abundant in low-temperature sedimentary environments where sulfate-reducing bacteria are also present. This study summarizes our research on reductive dissolution of ferrihydrite, goethite, hematite, magnetite, and a nontronite clay by Desulfovibrio spp. strain G-20 and strain G-11. The goal was twofold: (1) to understand the enzymatic processes of iron reduction by sulfate-reducing bacteria (SRB) using iron as the sole electron acceptor and (2) to determine whether iron reduction from the oxides and clays could be enhanced by biogenic H2S through an enzymatic process during sulfate reduction. In the iron-oxide experiments without sulfate, iron reduction by G-20 averaged about 4.5% of total iron for ferrihydrite, goethite, and hematite. The reduction of magnetite, however, was about threefold higher (13.3%). The maximum biomass of G-20 gained during iron reduction was also highest in the magnetite culture, suggesting that reduction of magnetite may have stimulated the growth of G-20. In the presence of sulfate, iron reduction was dramatically enhanced in all cultures (>70%). In inorganic experiments using Na2S, less than 4% total iron was reduced from goethite or hematite and about 19% was reduced from magnetite. The enhanced reduction of iron during sulfate reduction may have resulted from enzymatic activity of the SRB or through the chelation of solids with organic acids and other organic molecules. Transmission electron microscopy (TEM) showed shortened and thinned goethite and hematite crystals during sulfate and iron reduction. The magnetite crystals, on the other hand, were disintegrated extensively. For the nontronite experiments using G-11, iron reduction from the clay was about 10% of total structural Fe(III) in the absence of sulfate but reached 29% in the presence of sulfate. Abiotic iron reduction using Na2S, on the other hand, was ca. 7.5% of total structural Fe(III). Analyses of TEM and X-ray diffraction revealed significant changes in structure and composition of the clay during its dissolution by G-11. Overall, this study demonstrates that sulfate-reducing bacteria can dramatically enhance the dissolution of iron oxides and iron-rich clays, thus accelerating the transformation of these minerals in sulfate-rich environments.

  19. Nitrosative Stress and Apoptosis by Intravenous Ferumoxytol, Iron Isomaltoside 1000, Iron Dextran, Iron Sucrose, and Ferric Carboxymaltose in a Nonclinical Model.

    PubMed

    Toblli, J E; Cao, G; Giani, J F; Dominici, F P; Angerosa, M

    2015-07-01

    Iron is involved in the formation as well as in the scavenging of reactive oxygen and nitrogen species. Thus, iron can induce as well as inhibit both oxidative and nitrosative stress. It also has a key role in reactive oxygen and nitrogen species-mediated apoptosis. We assessed the differences in tyrosine nitration and caspase 3 expression in the liver, heart, and kidneys of rats treated weekly with intravenous ferumoxytol, iron isomaltoside 1000, iron dextran, iron sucrose and ferric carboxymaltose (40?mg iron/kg body weight) for 5 weeks. Nitrotyrosine was quantified in tissue homogenates by Western blotting and the distribution of nitrotyrosine and caspase 3 was assessed in tissue sections by immunohistochemistry. Ferric carboxymaltose and iron sucrose administration did not result in detectable levels of nitrotyrosine or significant levels of caspase 3?vs. control in any of the tissue studied. Nitrotyrosine and caspase 3 levels were significantly (p<0.01) increased in all assessed organs of animals treated with iron dextran and iron isomaltoside 1000, as well as in the liver and kidneys of ferumoxytol-treated animals compared to isotonic saline solution (control). Nitrotyrosine and caspase 3 levels were shown to correlate positively with the amount of Prussian blue-detectable iron(III) deposits in iron dextran- and iron isomaltoside 1000-treated rats but not in ferumoxytol-treated rats, suggesting that iron dextran, iron isomaltoside 1000 and ferumoxytol induce nitrosative (and oxidative) stress as well as apoptosis via different mechanism(s). PMID:25050519

  20. Synthesis of iron based hydrocracking catalysts

    DOEpatents

    Farcasiu, Malvina (Pittsburgh, PA); Eldredge, Patricia A. (Barboursville, VA); Ladner, Edward P. (Pittsburgh, PA)

    1993-01-01

    A method of preparing a fine particle iron based hydrocracking catalyst and the catalyst prepared thereby. An iron (III) oxide powder and elemental sulfur are reacted with a liquid hydrogen donor having a hydroaromatic structure present in the range of from about 5 to about 50 times the weight of iron (III) oxide at a temperature in the range of from about 180.degree. C. to about 240.degree. C. for a time in the range of from about 0 to about 8 hours. Various specific hydrogen donors are disclosed. The catalysts are active at low temperature (<350.degree. C.) and low pressure.