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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. Method of recovering and dewatering coarse sludge. [Magnitogorsk Integrated Iron and Steel Works-USSR

    SciTech Connect

    Medvedev, A.V.; Bogomolov, V.I.

    1981-01-01

    The washery has adopted a water-sludge system using centrifugal conical grates in the operation of sludge removal from the run-of-mine coal before jigging, dewatering of the large and fine coal machine concentrate and control classification of the primary and secondary sludges. The system was designed to separate and dewater the coarse sludge, then adding it to the flotation concentrate. The addition of the coarse sludge resulted in a decrease in the quantity of the dryer drum feed (from 27 to 23%), which decreased the moisture content of the dried product by 4 to 5%. The improvement in the granular composition and the decrease in the moisture and quantity of coal being dried stabilized the charging of the dryer drums, thus increasing the capacity and efficiency of the drying process. 1 table.

  3. Search for an optimal jigging machine operating regime. [Magnitogorsk Integrated Iron and Steel Works-USSR

    SciTech Connect

    Mamykin, Yu.S.; Rots, R.Yu.; Medvedev, A.V.; Zaplatkina, V.V.; Gulyanskii, A.A.

    1981-01-01

    An investigation of the operation of jigging machines for cleaning of fine coal was conducted under industrial conditions. Continuous monitoring was accomplished by the express analysis method in an aqueous solution of zinc chloride with the ash of the products determined. The capacity of the machines varied from 70 to 210 tons/h, the pulsator rotation speed from 41 to 97 rpm, and the air pressure from 12.7 to 13.7 kPa. The investigation was conducted by a passive experiment method. The tests showed that a change in the load from 170 to 190 tons/h with a simultaneous change in the content in the byproduct from 6.5 to 15% caused a decrease in the oscillation frequency from 80 to 65 rpm and a slight reduction in the cleaning efficiency (from 35 to 33.8%). With annual control the jigging efficiency averaged 23%.

  4. 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

  5. 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.

  6. 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

  7. Iron Deprivation Affects Drug Susceptibilities of Mycobacteria Targeting Membrane Integrity

    PubMed Central

    Pal, Rahul; Hameed, Saif; Fatima, Zeeshan

    2015-01-01

    Multidrug resistance (MDR) acquired by Mycobacterium tuberculosis (MTB) through continuous deployment of antitubercular drugs warrants immediate search for novel targets and mechanisms. The ability of MTB to sense and become accustomed to changes in the host is essential for survival and confers the basis of infection. A crucial condition that MTB must surmount is iron limitation, during the establishment of infection, since iron is required by both bacteria and humans. This study focuses on how iron deprivation affects drug susceptibilities of known anti-TB drugs in Mycobacterium smegmatis, a “surrogate of MTB.” We showed that iron deprivation leads to enhanced potency of most commonly used first line anti-TB drugs that could be reverted upon iron supplementation. We explored that membrane homeostasis is disrupted upon iron deprivation as revealed by enhanced membrane permeability and hypersensitivity to membrane perturbing agent leading to increased passive diffusion of drug and TEM images showing detectable differences in cell envelope thickness. Furthermore, iron seems to be indispensable to sustain genotoxic stress suggesting its possible role in DNA repair machinery. Taken together, we for the first time established a link between cellular iron and drug susceptibility of mycobacteria suggesting iron as novel determinant to combat MDR. PMID:26779346

  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

    MedlinePLUS

    ... deficiency anemia. Causes of low iron levels include blood loss, poor diet, or an inability to absorb enough iron from foods. People at higher risk of having too little iron are young ... to build up in the body. Centers for Disease Control and Prevention

  10. 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...

  11. Iron

    MedlinePLUS

    ... that contain vitamin C, like citrus fruits, strawberries, sweet peppers, tomatoes, and broccoli. What kinds of iron ... tiredness and lack of energy, GI upset, poor memory and concentration, and less ability to fight off ...

  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. 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

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

    PubMed

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

    2012-07-13

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

  15. Assessment of brain iron and neuronal integrity in patients with Parkinson's disease using novel MRI contrasts.

    PubMed

    Michaeli, Shalom; Oz, Glin; Sorce, Dennis J; Garwood, Michael; Ugurbil, Kamil; Majestic, Stacy; Tuite, Paul

    2007-02-15

    Postmortem demonstration of increased iron in the substantia nigra (SN) is a well-appreciated finding in Parkinson's disease (PD). Iron facilitates generation of free radicals, which are thought to play a role in dopamine neuronal loss. To date, however, magnetic resonance imaging (MRI) has failed to show significant in vivo differences in SN iron levels in subjects with PD versus control subjects. This finding may be due to the limitations in tissue contrasts achievable with conventional T(1)- and T(2)-weighted MRI sequences that have been used. With the recent development of novel rotating frame transverse (T(2rho)) and longitudinal (T(1rho)) relaxation MRI methods that appear to be sensitive to iron and neuronal loss, respectively, we embarked on a study of 8 individuals with PD (Hoehn & Yahr, Stage II) and 8 age-matched control subjects. Using these techniques with a 4T MRI magnet, we assessed iron deposits and neuronal integrity in the SN. First, T(2rho) MRI, which is reflective of iron-related dynamic dephasing mechanisms (e.g., chemical exchange and diffusion in the locally different magnetic susceptibilities), demonstrated a statistically significant difference between the PD and control group, while routine T(2) MRI did not. Second, T(1rho) measurements, which appear to reflect upon neuronal count, indicated neuronal loss in the SN in PD. We show here that sub-millimeter resolution T(1rho) and T(2rho) MRI relaxation methods can provide a noninvasive measure of iron content as well as evidence of neuronal loss in the midbrain of patients with PD. PMID:17149719

  16. 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.

  17. Chemical constituents in particulate emissions from an integrated iron and steel facility.

    PubMed

    Tsai, Jiun-Horng; Lin, Kuo-Hsiung; Chen, Chih-Yu; Ding, Jian-Yuan; Choa, Ching-Guan; Chiang, Hung-Lung

    2007-08-17

    Particle emissions from four integrated iron and steel plant processes, i.e., coke making, sintering, cold forming, and hot forming, were investigated in this study. Particle compositions of 21 element species, 11 ionic species, elemental carbon (EC), organic carbon (OC) and 16 polyaromatic hydrocarbons (PAHs) were analyzed to create "fingerprints" of the particles emitted from various processes in an integrated iron and steel plant. Results indicated that element compositions (0.11-0.42 g/g), water-soluble ions (0.34-0.52 g/g), elemental carbon (0.008-0.14 g/g), organic carbon (0.02-0.06 g/g) and PAHs (0.52-6.2 mg/g) contributed to the particle mass. In general, sulfur had a higher mass contribution than the other elements, which resulted from the use of coal, flux, heavy oil, and many recycled materials in the iron and steel plant. The particle mass contribution of potassium and chlorine in the sinter plant was higher than in other processes; this may be attributed to the lower boiling point and volatility of potassium. In addition, many recycled materials were fed into the sinter plant, causing a high concentration of potassium and chlorine in the particle phase. Eight PAH compounds were analyzed in the four processes. The carcinogenic compound Benzo(a)pyrene (BaP) was detectable only in the sintering process. PMID:17276592

  18. Chemical profile identification of fugitive and confined particle emissions from an integrated iron and steelmaking plant.

    PubMed

    Hleis, Dany; Fernández-Olmo, Ignacio; Ledoux, Frédéric; Kfoury, Adib; Courcot, Lucie; Desmonts, Thérèse; Courcot, Dominique

    2013-04-15

    The aim of this study is to obtain the characteristic inorganic chemical profile of important particle sources identified in the integrated iron and steel process: sintering, blast furnace, steelmaking and desulfurization slag processing. A complete chemical and physical characterization program was developed: particle size distribution, chemical analysis, XRD, SEM-EDX and TGA/DTA. The sample collected from the sinter stack showed high levels of K and Cl(-), followed by Fe, NH4(+), Ca, Na and Pb. The profile of the dust samples taken from the sinter cake discharge zone was quite different, showing higher amounts of Fe, Ca and Al, and lower amounts of K, Cl(-), Na and Pb. Dust samples collected from the blast furnace (BF) and steelmaking cast house may be distinguished from each other based on the higher levels of Fe (hematite and magnetite) and lower levels of Ca, Zn and C (graphite) found in BF dust. High levels of Ca and Fe were found in samples taken from the desulfurization slag processing area. Such information can be useful for source apportionment studies at receptor sites that could be influenced by iron and steelmaking plant emissions. PMID:23454464

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

    PubMed

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

    2014-11-01

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

  20. 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

  1. Bisphenol A mineralization by integrated ultrasound-UV-iron (II) treatment.

    PubMed

    Torres, Ricardo A; Pétrier, Christian; Combet, Evelyne; Moulet, Florence; Pulgarin, Cesar

    2007-01-01

    Bisphenol A (BPA), an organic compound largely used in the plastic industry as a monomer for production of epoxy resins and polycarbonate, is an emerging contaminant that is released in the environmentfrom bottles and packaging. BPA degradation (118 micromol L(-1)) under sonochemical conditions was investigated in this study, using a 300 kHz frequency, with a 80 W electrical power. Under these conditions, BPA was eliminated by the ultrasound process (-90 min). However, even after long ultrasound irradiation periods (10 h), more than 50% of chemical oxygen demand (COD) and 80% of total organic carbon (TOC) remained in the solution, indicating that most BPA intermediates are recalcitrant toward ultrasonic action. Accumulation of hydrogen peroxide from *OH and *OOH radical recombination was also observed. To increase the efficiency of BPA treatment, experiments combined ultrasound with Fe2+ (100 micromol L(-1)) and/or UV radiation (254 nm): Ultrasound/UV; Ultrasound/Fe2+; Ultrasound/UV/ Fe2+. Both UV and Fe2+ induced hydrogen peroxide dissociation, leading to additional *OH radicals and complete COD and TOC removal. Thus difficulties in obtaining mineralization of micropollutants like BPA through ultrasonic action alone, can be overcome by the Ultrasound/UV/ Fe2+ combination. Moreover, this technique was found to be the most cost-effective one. So, the integrated ultrasound-UV-iron(ll) process was shown to be of interest for the treatment of wastewaters contaminated with BPA. PMID:17265962

  2. 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 ...

  3. Synthesis of iron-based chemical looping sorbents integrated with pH swing carbon mineral sequestration.

    PubMed

    Kim, Hyung Ray; Lee, Dong Hyun; Fan, Liang-Shih; Park, Ah-Hyung Alissa

    2009-12-01

    The previously developed pH swing carbon mineral sequestration immobilizes the gaseous CO2 into a thermodynamically stable solid, MgCO3, using Mg-bearing minerals such as serpentine. This mineral carbonation technology is particularly promising since it generates value-added solid products: high surface area silica, iron oxide, and magnesium carbonate, while providing a safe and permanent storage option for CO2. By carefully controlling the pH of the system, these solids products can be produced with high purity. This study focuses on the synthesis of iron oxide particles as a chemical looping sorbent in order to achieve the integration between carbon capture and storage technologies. Since the solubility of Fe in aqueous phase is relatively low at neutral pH, the effect of the weak acid and chelating agents on the extraction of Fe from serpentine was investigated. The synthesized iron-based chemical looping sorbent was found to be as effective as commercially available iron oxide nanoparticles at converting syngas into high purity H2, while producing a sequestration-ready CO2 stream. PMID:19908801

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

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  5. 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.

  6. 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.

  7. 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...

  8. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  10. 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.

  11. 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

  12. 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. ...

  13. 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.

  14. Integration to Implementation and the Micronutrient Forum: A Coordinated Approach for Global Nutrition. Case Study Application: Safety and Effectiveness of Iron Interventions.

    PubMed

    Raiten, Daniel J; Neufeld, Lynnette M; De-Regil, Luz-Maria; Pasricha, Sant-Rayn; Darnton-Hill, Ian; Hurrell, Richard; Murray-Kolb, Laura E; Nair, K Madhavan; Wefwafwa, Terry; Kupka, Roland; Phall, Modou Cheyassin; Sakr Ashour, Fayrouz A

    2016-01-01

    Paramount among the challenges to our ability to address the role of food and nutrition in health promotion and disease prevention is how to design and implement context-specific interventions and guidance. The Integration to Effective Implementation (I-to-I) concept is intended to address the complexities of the global health context through engagement of the continuum of stakeholders involved in the food and nutrition enterprise. The 2014 Micronutrient Forum (MNF) Global Conference held in Addis Ababa, Ethiopia, in June 2014 offered the opportunity to apply the I-to-I approach with the use of current concerns about the safety and effectiveness of interventions to prevent and treat iron deficiency (ID) as a case study. ID is associated with a range of adverse outcomes, especially in pregnant and nonpregnant women, infants, and primary school-age children. Strategies to combat ID include iron supplementation, multiple micronutrient powders, and food-based interventions to enhance dietary iron intake. Recent reports indicate potential increased adverse risks when iron is provided in areas with high infection burdens (e.g., malaria). This paradox has weakened iron intervention programs. Furthermore, the selection and interpretation of available biomarkers for assessing iron nutrition have been found to be compromised by the inflammatory process. These issues highlight the need for a comprehensive approach that considers basic biology, assessment, interventions, and how these can be translated into appropriate programs and policies. The application of the I-to-I with the use of the MNF offered an opportunity to explore how that might be achieved. PMID:26773021

  15. 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.

  16. 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

  17. 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 800C 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

  18. 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

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

    PubMed

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

    2012-10-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  1. 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.

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

    PubMed Central

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

    2011-01-01

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

  3. Iron deficiency.

    PubMed

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world. PMID:1745900

  4. 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.

  5. Evaluation of effects of Ma??urabhasma on structural and functional integrity of small intestine in comparison with ferrous sulfate using an experimental model of iron deficiency anemia

    PubMed Central

    Gawde, Suchita Rajanikant; Patel, Tejal C.; Rege, Nirmala N.; Gajbhiye, Snehalata; Uchil, Dinesh

    2015-01-01

    Background: The present study was planned to assess effects of Ma??urabhasma (MB) on structural and functional integrity of small intestine using an animal model of iron deficiency anemia (IDA) in rat. Methods: IDA was induced by giving iron deficient diet and retro-orbital bloodletting for 21 days in Wistar female rats. Rats (n = 72) were divided into six groups: (i) Control group, (ii) IDA rats, (iii) IDA rats receiving vehicle, (iv) rats receiving ferrous sulfate (40 mg/kg), (vi) rats receiving a low dose (22.5 mg/kg) of MB, (vi) rats receiving a high dose (45 mg/kg) of MB. Treatment was conducted for a period of 21 days followed by an assessment of change in hemoglobin (Hb) levels, lactase levels, lipid peroxidation activity by measuring malondialdehyde (MDA) levels and jejunal morphometry. Results: In the present study, the lactase activity was markedly reduced in iron-deficient rats. Our study has demonstrated that intestinal morphology and MDA levels were not altered in the animals with IDA as compared to normal animals. In phase II, improvement in Hb response to ferrous sulfate was accompanied by an improvement in lactase activity. However, it significantly increased MDA levels with derangement of the normal villous structure. Rats receiving a low dose of MB did not have increased MDA levels. It did not alter the jejunal villous structure and improved lactase activity, but hematinic activity was found to be less than that of ferrous sulfate. Rats receiving a high dose of MB showed significantly improved Hb as well as lactase levels. They exhibited damage to the villous structure and increased MDA levels, but the effects were significantly less as compared to ferrous sulfate group. Conclusion: Rats receiving a high dose of MB have shown improvement in hematinic and lactase levels comparable to those receiving ferrous sulfate. However, it causes lesser oxidative damage as compared to ferrous sulfate. This is an encouraging finding because it indicates the potential of MB to cause lesser gastrointestinal side effects compared to ferrous sulfate. PMID:26120227

  6. Improved ammonium sulfate production equipment at the Orsk-Khalilovo Integrated Iron and Steel Works (OKhMK)

    SciTech Connect

    Kirillov, V.A.; Kuznetsov, M.K.; Antonov, A.V.; Vorob'ev, S.E.; Kuznetsov, V.Ya.; Bukreev, V.P.

    1981-01-01

    In the Orsk-Khalilovo coking plant, ammonium sulfate is made entirely from spent sulfuric acid supplied by the spirits plant in the Orsknefteorgsintez Association. The spent acid has a low concentration of H/sub 2/SO/sub 4/ monohydrate (67 to 72%) and is colored black by a suspension of inorganic and organic impurities. The inorganic impurities particularly harmful to the growth of ammonium sulfate crystals include iron salts (Fe content 0.04 to 0.06 wt %). In the ammonium sulfate plant they become insoluble and adsorb acid sludge; consequently, they are retained in the liquor and stain the finished ammonium sulfate. The organic impurities in the spent acid (equivalent to 0.6 to 0.8 wt % free carbon) precipitate on the ammonium sulfate crystals, thereby slowing down their growth and making the product fine and stained. Moreover, the use of spent acid causes frothing in the mother liquor; froth overflows from the circulation boxes and the operating conditions are difficult to observe. With spent acid of this low quality it is impossible to produce high-grade ammonium sulfate by the methods usually advocated. By improving the agitation of mother liquor in the saturator bath, diverting the return stream to the gas-lift cylinder and installing hydrocyclones, the quality of the ammonium sulfate has been raised: the >0.25 mm size fraction content has risen from 57 to 74%, and the acidity of the product has been reduced from 0.048 to 0.030 wt %. The average monthly yield of grade I product has risen from 2.8 to 50.0%.

  7. 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

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

    PubMed

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

    2014-06-01

    Nanosized zero-valent iron (nZVI) is a new option for the remediation of contaminated soil and groundwater, but the effect of nZVI on soil biota is mostly unknown. In this work, nanotoxicological studies were performed in vitro and in two different standard soils to assess the effect of nZVI on autochthonous soil organisms by integrating classical and molecular analysis. Standardised ecotoxicity testing methods using Caenorhabditis elegans were applied in vitro and in soil experiments and changes in microbial biodiversity and biomarker gene expression were used to assess the responses of the microbial community to nZVI. The classical tests conducted in soil ruled out a toxic impact of nZVI on the soil nematode C. elegans in the test soils. The molecular analysis applied to soil microorganisms, however, revealed significant changes in the expression of the proposed biomarkers of exposure. These changes were related not only to the nZVI treatment but also to the soil characteristics, highlighting the importance of considering the soil matrix on a case by case basis. Furthermore, due to the temporal shift between transcriptional responses and the development of the corresponding phenotype, the molecular approach could anticipate adverse effects on environmental biota. PMID:24287264

  9. 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

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

    PubMed Central

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

    2012-01-01

    Geochemical, molecular, and physiological analyses of microbial isolates were combined to study the geomicrobiology of acidic iron oxide mats in Yellowstone National Park. Nineteen sampling locations from 11 geothermal springs were studied ranging in temperature from 53 to 88C 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 6570C, but increased in diversity below 60C. 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 88C. PMID:22470372

  11. 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

  12. Serum iron test

    MedlinePLUS

    ... test if you have signs of low iron (iron deficiency) or too much iron. ... Brittenham GM. Disorders of iron homeostasis: iron deficiency and ... Basic Principles and Practice . 6th ed. Philadelphia, Pa: ...

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

    PubMed

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

    2014-10-01

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

  14. 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.

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

    PubMed

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

    2014-10-20

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

  16. Glutathione S-transferase and MRP1 form an integrated system involved in the storage and transport of dinitrosyl-dithiolato iron complexes in cells.

    PubMed

    Lok, H C; Sahni, S; Richardson, V; Kalinowski, D S; Kovacevic, Z; Lane, D J R; Richardson, D R

    2014-10-01

    Nitrogen monoxide (NO) is vital for many essential biological processes as a messenger and effector molecule. The physiological importance of NO is the result of its high affinity for iron in the active sites of proteins such as guanylate cyclase. Indeed, NO possesses a rich coordination chemistry with iron and the formation of dinitrosyl-dithiolato iron complexes (DNICs) is well documented. In mammals, NO generated by cytotoxic activated macrophages has been reported to play a role as a cytotoxic effector against tumor cells by binding and releasing intracellular iron. Studies from our laboratory have shown that two proteins traditionally involved in drug resistance, namely multidrug-resistance protein 1 and glutathione S-transferase, play critical roles in intracellular NO transport and storage through their interaction with DNICs (R.N. Watts et al., Proc. Natl. Acad. Sci. USA 103:7670-7675, 2006; H. Lok et al., J. Biol. Chem. 287:607-618, 2012). Notably, DNICs are present at high concentrations in cells and are biologically available. These complexes have a markedly longer half-life than free NO, making them an ideal "common currency" for this messenger molecule. Considering the many critical roles NO plays in health and disease, a better understanding of its intracellular trafficking mechanisms will be vital for the development of new therapeutics. PMID:25035074

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  18. 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

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

    PubMed

    Albarouki, Emad; Deising, Holger B

    2013-06-01

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

  20. Iron Dextran Injection

    MedlinePLUS

    Iron dextran injection is used to treat iron-deficiency anemia (a lower than normal number of red blood ... be treated with iron supplements taken by mouth. Iron dextran injection is in a class of medications called ...

  1. 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 Dynatecs 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.

  2. 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.

  3. Iron and iron derived radicals

    SciTech Connect

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

    1987-04-01

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

  4. Bacterial iron homeostasis.

    PubMed

    Andrews, Simon C; Robinson, Andrea K; Rodrguez-Quiones, Francisco

    2003-06-01

    Iron is essential to virtually all organisms, but poses problems of toxicity and poor solubility. Bacteria have evolved various mechanisms to counter the problems imposed by their iron dependence, allowing them to achieve effective iron homeostasis under a range of iron regimes. Highly efficient iron acquisition systems are used to scavenge iron from the environment under iron-restricted conditions. In many cases, this involves the secretion and internalisation of extracellular ferric chelators called siderophores. Ferrous iron can also be directly imported by the G protein-like transporter, FeoB. For pathogens, host-iron complexes (transferrin, lactoferrin, haem, haemoglobin) are directly used as iron sources. Bacterial iron storage proteins (ferritin, bacterioferritin) provide intracellular iron reserves for use when external supplies are restricted, and iron detoxification proteins (Dps) are employed to protect the chromosome from iron-induced free radical damage. There is evidence that bacteria control their iron requirements in response to iron availability by down-regulating the expression of iron proteins during iron-restricted growth. And finally, the expression of the iron homeostatic machinery is subject to iron-dependent global control ensuring that iron acquisition, storage and consumption are geared to iron availability and that intracellular levels of free iron do not reach toxic levels. PMID:12829269

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

    MedlinePLUS

    ... Genetic disorder catalog Conditions > Iron-refractory iron deficiency anemia On this page: Description Genetic changes Inheritance Diagnosis ... July 2014 What is iron-refractory iron deficiency anemia? Iron-refractory iron deficiency anemia is one of ...

  6. [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

  7. Ironing out Ferroportin.

    PubMed

    Drakesmith, Hal; Nemeth, Elizabeta; Ganz, Tomas

    2015-11-01

    Maintaining physiologic iron concentrations in tissues is critical for metabolism and host defense. Iron absorption in the duodenum, recycling of iron from senescent erythrocytes, and iron mobilization from storage in macrophages and hepatocytes constitute the major iron flows into plasma for distribution to tissues, predominantly for erythropoiesis. All iron transfer to plasma occurs through the iron exporter ferroportin. The concentration of functional membrane-associated ferroportin is controlled by its ligand, the iron-regulatory hormone hepcidin, and fine-tuned by regulatory mechanisms serving iron homeostasis, oxygen utilization, host defense, and erythropoiesis. Fundamental questions about the structure and biology of ferroportin remain to be answered. PMID:26437604

  8. 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.

  9. [Iron's ups and downs].

    PubMed

    Gilles, A

    2013-09-01

    Iron is an essential trace metal whose extracellular concentration and stores are efficiently regulated. Systemic iron homeostasis assures a stable milieu in which each cell regulates its iron uptake to meet its own requirements. The system is challenged by variable availability of iron in the diet, by occasional iron losses through bleeding and by the fluctuations in the iron request by iron requiring processes such as erythropoiesis, growth, pregnancy and lactation; but also by pathologic processes involving aberrant iron retention leading to tissue iron overload and finally to end organ damage. A low serum ferritin is 100% specific for iron deficiency ; conversely hyperferritinemia is not a reliable sign of iron overload. Iron deficiency is a pan-ethnic disorder more prevalent in western and ageing people. Anemia represents the end stage of iron deficiency. During inflammatory states, iron becomes unavailable for erythropoiesis although adequate stores are present. This phenomenon is called functional iron deficiency and is characteristic of anemia of chronic disorders. Hyperferritinemia may exist in the presence or in the absence of iron overload. A cut off value of > 45% for transferrine saturation has been suggested to discriminate both settings. All the acquired conditions associated with hyperferritinemia must be excluded before performing genetic testing. Perfect understanding of iron homeostasis regulation as well as an adequate use of analyses exploring iron metabolism are mandatory for proper clinical management of iron deficiency and overload states. PMID:24195248

  10. 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.

  11. Iron in diet

    MedlinePLUS

    ... leafy greens at a meal, you can improve absorption of vegetable sources of iron up to three ... citrus, strawberries, tomatoes, and potatoes) also increase iron absorption. Cooking foods in a cast-iron skillet can ...

  12. Iron and Your Child

    MedlinePLUS

    ... to eat iron-rich foods. Milk decreases the absorption of iron and can also irritate the lining ... broccoli, oranges, and strawberries — which improves the body's absorption of iron. Avoid serving coffee or tea at ...

  13. Iron Sucrose Injection

    MedlinePLUS

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

  14. Iron and Your Child

    MedlinePLUS

    ... to eat iron-rich foods. Milk decreases the absorption of iron and can also irritate the lining ... broccoli, oranges, and strawberries which improves the body's absorption of iron. Avoid serving coffee or tea at ...

  15. 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....

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

    MedlinePLUS

    ... are related to iron-refractory iron deficiency anemia? Mutations in the TMPRSS6 gene cause iron-refractory iron ... regulate iron levels in the body. TMPRSS6 gene mutations reduce or eliminate functional matriptase-2, which disrupts ...

  17. Iron-Refractory Iron Deficiency Anemia

    PubMed Central

    Y?lmaz Keskin, Ebru; Yenicesu, ?dil

    2015-01-01

    Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the atypical microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field. PMID:25805669

  18. HEPCIDIN AND IRON HOMEOSTASIS

    PubMed Central

    Ganz, Tomas; Nemeth, Elizabeta

    2014-01-01

    Despite fluctuations in dietary iron intake and intermittent losses through bleeding, the plasma iron concentrations in humans remain stable at 1030 ?M. While most of the iron entering blood plasma comes from recycling, appropriate amount of iron is absorbed from the diet to compensate for losses and maintain nontoxic amounts in stores. Plasma iron concentration and iron distribution are similarly regulated in laboratory rodents. The hepatic peptide hepcidin was identified as the systemic iron-regulatory hormone. In the efferent arc, hepcidin regulates intestinal iron absorption, plasma iron concentrations, and tissue iron distribution by inducing degradation of its receptor, the cellular iron exporter ferroportin. Ferroportin exports iron into plasma from absorptive enterocytes, from macrophages that recycle the iron of senescent erythrocytes, and from hepatocytes that store iron. In the more complex and less well understood afferent arc, hepatic hepcidin synthesis is transcriptionally regulated by extracellular and intracellular iron concentrations through a molecular complex of bone morphogenetic protein receptors and their iron-specific ligands, modulators and iron sensors. Through as yet undefined pathways, hepcidin is also homeostatically regulated by the iron requirements of erythroid precursors for hemoglobin synthesis. In accordance with the role of hepcidin-mediated iron redistribution in host defense, hepcidin production is regulated by inflammation as well. Increased hepcidin concentrations in plasma are pathogenic in iron-restrictive anemias including anemias associated with inflammation, chronic kidney disease and some cancers. Hepcidin deficiency causes iron overload in hereditary hemochromatosis and ineffective erythropoiesis. Hepcidin, ferroportin and their regulators represent potential targets for the diagnosis and treatment of iron disorders and anemias. PMID:22306005

  19. Iron-refractory iron deficiency anemia.

    PubMed

    Kawabata, Hiroshi

    2016-01-01

    The major causes of iron deficiency anemia (IDA) include iron loss due to bleeding, increased iron requirements, and decreased iron absorption by the intestine. The most common cause of IDA in Japanese women is iron loss during menstruation. Autoimmune atrophic gastritis and Helicobacter pylori infection can also cause IDA by reducing intestinal iron absorption. In addition to these common etiologies, germline mutations of TMPRSS6 can cause iron-refractory IDA (IRIDA). TMPRSS6 encodes matriptase-2, a membrane-bound serine protease primarily expressed in the liver. Functional loss of matriptase-2 due to homozygous mutations results in an increase in the expression of hepcidin, which is the key regulator of systemic iron homeostasis. The serum hepcidin increase in turn leads to a decrease in iron supply from the intestine and macrophages to erythropoietic cells. IRIDA is microcytic and hypochromic, but decreased serum ferritin is not observed as in IDA. IRIDA is refractory to oral iron supplementation, but does respond to intravenous iron supplementation to some extent. Because genetic testing is required for the diagnoses of IRIDA, a considerable number of cases may go undiagnosed and may thus be overlooked. PMID:26935626

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

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

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

  1. Pathways of iron absorption.

    PubMed

    Conrad, Marcel E; Umbreit, Jay N

    2002-01-01

    Iron is vital for all living organisms but excess iron can be lethal because it facilitates free radical formation. Thus iron absorption is carefully regulated to maintain an equilibrium between absorption and body loss of iron. In countries where meat is a significant part of the diet, most body iron is derived from dietary heme because heme binds few of the dietary chelators that bind inorganic iron. Uptake of heme into enterocytes occurs as a metalloporphyrin in an endosomal process. Intracellular iron is released from heme by heme oxygenase to enter plasma as inorganic iron. Ferric iron is absorbed via a beta(3) integrin and mobilferrin pathway (IMP) which is unshared with other nutritional metals. Ferrous iron uptake is facilitated by a DMT-1 pathway which is shared with manganese. In the iron deficient gut, large quantities of both mobilferrin and DMT-1 are found in goblet cells and intraluminal mucins suggesting that they are secreted with mucin into the intestinal lumen to bind iron to facilitate uptake by the cells. In the cytoplasm, IMP and DMT associate in a large protein complex called paraferritin which serves as a ferrireductase. Paraferritin solublizes iron binding proteins and reduces iron to make iron available for production of iron containing proteins such as heme. Iron uptake by intestinal absorptive cells is regulated by the iron concentration within the cell. Except in hemochromatosis it remains in equilibrium with total body stores via transferrin receptors on the basolateral membrane of absorptive cells. Increased intracellular iron either up-regulates or satiates iron binding proteins on regulatory proteins to alter their location in the intestinal mucosa. PMID:12547224

  2. Iron metabolism in transplantation.

    PubMed

    Schaefer, Benedikt; Effenberger, Maria; Zoller, Heinz

    2014-11-01

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

  3. 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

  4. Iron supplementation in pregnancy.

    PubMed

    Mngen, Ercment

    2003-01-01

    Iron deficiency is the most common nutritional disorder in the world. Pregnant women are at especially high risk for iron deficiency and iron deficiency anemia. A considerable proportion of pregnant women in both developing and industrialized countries become anemic during pregnancy. The prevalence of anemia in pregnant women has remained unacceptably high worldwide despite the fact that routine iron supplementation during pregnancy has been almost universally recommended to prevent maternal anemia, especially in developing countries over the past 30 years. The major problem with iron supplementation during pregnancy is compliance. Despite many studies, the relationship between maternal anemia and adverse pregnancy outcome is unclear. However, there is now sufficient evidence that iron supplements increase hemoglobin and serum ferritin levels during pregnancy and also improve the maternal iron status in the puerperium, even in women who enter pregnancy with adequate iron stores. Recent information also suggests an association between maternal iron status in pregnancy and the iron status of infants postpartum. The necessity of routine iron supplementation during pregnancy has been debated in industrialized countries and routine supplementation is not universally practiced in all these countries. In view of existing data, however, routine iron supplementation during pregnancy seems to be a safe strategy to prevent maternal anemia in developing countries, where traditional diets provide inadequate iron and where malaria and other infections causing increased losses are endemic. PMID:14601265

  5. 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.

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

    PubMed

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

    2012-08-30

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

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

    PubMed

    Shi, Baoyou; Taylor, James S

    2007-09-01

    A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature. PMID:17886579

  8. Ferrous Sulfate (Iron)

    MedlinePLUS

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

  9. 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

  10. Iron and the liver.

    PubMed

    Pietrangelo, Antonello

    2016-01-01

    Humans have evolved to retain iron in the body and are exposed to a high risk of iron overload and iron-related toxicity. Excess iron in the blood, in the absence of increased erythropoietic needs, can saturate the buffering capacity of serum transferrin and result in non-transferrin-bound highly reactive forms of iron that can cause damage, as well as promote fibrogenesis and carcinogenesis in the parenchymatous organs. A number of hereditary or acquired diseases are associated with systemic or local iron deposition or iron misdistribution in organs or cells. Two of these, the HFE- and non-HFE hemochromatosis syndromes represent the paradigms of genetic iron overload. They share common clinical features and the same pathogenic basis, in particular, a lack of synthesis or activity of hepcidin, the iron hormone. Before hepcidin was discovered, the liver was simply regarded as the main site of iron storage and, as such, the main target of iron toxicity. Now, as the main source of hepcidin, it appears that the loss of the hepcidin-producing liver mass or genetic and acquired factors that repress hepcidin synthesis in the liver may also lead to iron overload. Usually, there is low-grade excess iron which, through oxidative stress, is sufficient to worsen the course of the underlying liver disease or other chronic diseases that are apparently unrelated to iron, such as chronic metabolic and cardiovascular diseases. In the future, modulation of hepcidin synthesis and activity or hepcidin hormone-replacing strategies may become therapeutic options to cure iron-related disorders. PMID:26725908

  11. 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

  12. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  15. Macrophages and Iron Metabolism.

    PubMed

    Soares, Miguel P; Hamza, Iqbal

    2016-03-15

    Iron is a transition metal that due to its inherent ability to exchange electrons with a variety of molecules is essential to support life. In mammals, iron exists mostly in the form of heme, enclosed within an organic protoporphyrin ring and functioning primarily as a prosthetic group in proteins. Paradoxically, free iron also has the potential to become cytotoxic when electron exchange with oxygen is unrestricted and catalyzes the production of reactive oxygen species. These biological properties demand that iron metabolism is tightly regulated such that iron is available for core biological functions while preventing its cytotoxic effects. Macrophages play a central role in establishing this delicate balance. Here, we review the impact of macrophages on heme-iron metabolism and, reciprocally, how heme-iron modulates macrophage function. PMID:26982356

  16. Iron deficiency anaemia.

    PubMed

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

    2016-02-27

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

  17. The ubiquity of iron.

    PubMed

    Frey, Perry A; Reed, George H

    2012-09-21

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

  18. Brain iron homeostasis.

    PubMed

    Moos, Torben

    2002-11-01

    Iron is essential for virtually all types of cells and organisms. The significance of the iron for brain function is reflected by the presence of receptors for transferrin on brain capillary endothelial cells. The transport of iron into the brain from the circulation is regulated so that the extraction of iron by brain capillary endothelial cells is low in iron-replete conditions and the reverse when the iron need of the brain is high as in conditions with iron deficiency and during development of the brain. Whereas there is good agreement that iron is taken up by means of receptor-mediated uptake of iron-transferrin at the brain barriers, there are contradictory views on how iron is transported further on from the brain barriers and into the brain extracellular space. The prevailing hypothesis for transport of iron across the BBB suggests a mechanism that involves detachment of iron from transferrin within barrier cells followed by recycling of apo-transferrin to blood plasma and release of iron as non-transferrin-bound iron into the brain interstitium from where the iron is taken up by neurons and glial cells. Another hypothesis claims that iron-transferrin is transported into the brain by means of transcytosis through the BBB. This thesis deals with the topic "brain iron homeostasis" defined as the attempts to maintain constant concentrations of iron in the brain internal environment via regulation of iron transport through brain barriers, cellular iron uptake by neurons and glia, and export of iron from brain to blood. The first part deals with transport of iron-transferrin complexes from blood to brain either by transport across the brain barriers or by uptake and retrograde axonal transport in motor neurons projecting beyond the blood-brain barrier. The transport of iron and transport into the brain was examined using radiolabeled iron-transferrin. Intravenous injection of [59Fe-125]transferrin led to an almost two-fold higher accumulation of 59Fe than of [125I]transferrin in the brain. Some of the 59Fe was detected in CSF in a fraction less than 30 kDa (III). It was estimated that the iron-binding capacity of transferrin in CSF was exceeded, suggesting that iron is transported into the brain in a quantity that exceeds that of transferrin. Accordingly, it was concluded that the paramount iron transport across the BBB is the result of receptor-mediated endocytosis of iron-containing transferrin by capillary endothelial cells, followed by recycling of transferrin to the blood and transport of non-transferrin-bound iron into the brain. It was found that retrograde axonal transport in a cranial motor nerve is age-dependent, varying from almost negligible in the neonatal brain to high in the adult brain. The principle sources of extracellular transferrin in the brain are hepatocytes, oligodendrocytes, and the choroid plexus. As the passage of liver-derived transferrin into the brain is restricted due to the BBB, other candidates for binding iron in the interstitium should be considered. In vitro studies have revealed secretion of transferrin from the choroid plexus and oligodendrocytes. The second part of the thesis encompasses the circulation of iron in the extracellular fluids of the brain, i.e. the brain interstitial fluid and the CSF. As the latter receives drainage from the interstitial fluid, the CSF of the ventricles can be considered a mixture of these fluids, which may allow for analysis of CSF in matters that relate to the brain interstitial fluid. As the choroid plexus is known to synthesize transferrin, a key question is whether transferrin of the CSF might play a role for iron homeostasis by diffusing from the ventricles and subarachnoid space to the brain interstitium. Intracerebroventricular injection of [59Fe125I]transferrin led to a higher accumulation of 59Fe than of [125I]transferrin in the brain. Except for uptake and axonal transport by certain neurons with access to the ventricular CSF, both iron and transferrin were, however, restricted to areas situated in close proximity to the ventricular and pial surfaces. In particular, transferrin injected into the ventricles was never observed in regions distant from the CSF. It was concluded that choroid plexus-derived transferrin is not likely to play a significant role for binding and transporting iron in the brain interstitium. Transferrin secretion from oligodendrocytes probably plays the key role in this process. In the third part of the thesis, the uptake of iron by neurons devoid of projections beyond the blood-brain barrier and glia is addressed. Given the fact that the demonstration of plasma proteins in brain sections can be hampered by several methodological factors, a mapping of the cellular distribution of transferrin in the brain was performed employing extensive use of tissue-processing and staining protocols. In order to aid in the understanding of cellular iron uptake in the intact brain, attempts were made to identify iron, transferrin, and transferrin receptors at the light microscopic level. Consistent with the widespread distribution of transferrin receptors in neurons, the ligand transferrin was also found in neurons throughout the CNS. When examined at high resolution, transferrin was found to be distributed to the cytoplasm of neurons, exhibiting a dotted appearance, which is probably consistent with a distribution in the endosomallysosomal system. In contrast to the consistent presence of transferrin receptors on neurons, it was not possible to detect transferrin receptors on glial cells. Related to these observations, the presence of non-transferrin-bound iron in the brain suggests that glial cells may take it up by a mechanism that does not involve the transferrin receptor. The widespread distribution of ferritin in glial cells clearly indicates that the glial cells acquire iron. Dietary iron-overload did not change the distribution of transferrin receptors or ferritin in the brain. By contrast, iron deficiency altered the cellular content of these proteins so that transferrin receptors were higher and ferritin lower. The transport of iron from brain to blood was addressed in the last part of the thesis. It was found that in the case of iron and transferrin, there is no evidence showing other significant routes of transport from the brain extracellular fluid into the blood than drainage to the ventricular system followed by export to the blood via the arachnoid villi. The turnover of transferrin in the CSF was found to be very high. For reasons mentioned above, transferrin of the CSF is of little significance for transport and cellular delivery of iron to transferrin receptor-expressing neurons. Instead, transferrin of the CSF probably plays a significant role for neutralization and export to the blood of metals, including iron. Once appearing in blood, transferrin of the CSF was degraded at the same rate as intravenously injected transferrin, which indicates that the transferrin of CSF is not altered to an extent that changes its catabolism during the passage from CSF to blood plasma. The metabolism of iron in the developing brain was found to differ markedly when compared to that of the adult brain. A developing regulated transfer of iron to the brain was reflected morphologically by a higher content of transferrin receptors and non-heme iron in endothelial cells of the developing rat brain than in the adult. Neurons had a very low level of transferrin receptors. After about 20 days of age, iron transport into the brain decreased rapidly, and transferrin receptors appeared on neurons. Iron and transferrin injected into the ventricular system of the developing brain were much more widely distributed in the brain parenchyma than in the adult brain. This high accumulation of substances injected into the ventricles in young animals is probably due to the lower rate of production and turnover of CSF, which will increase the time available for diffusion of proteins into the brain parenchyma, thus giving neurons of the developing brain the opportunity to take up transferrin originating from the CSF. PMID:12553165

  19. Electrolytic iron or ferrous sulfate increase body iron in women with moderate to low iron stores.

    PubMed

    Swain, James H; Johnson, LuAnn K; Hunt, Janet R

    2007-03-01

    Commercial elemental iron powders (electrolytic and reduced iron), as well as heme iron supplements, were tested for efficacy in improving the iron status of women. In a randomized, double-blind trial, 51 women with moderate to low iron stores received daily for 12 wk: 1) placebo, 2) 5 mg iron as heme iron or 50 mg iron as 3) electrolytic iron, 4) reduced iron, or 5) FeSO(4). Treatments were provided in 2 capsules (heme carrier) and 3 wheat rolls (other iron sources). Differences in iron status, food nonheme iron absorption, and fecal properties were evaluated. Body iron, assessed from the serum transferrin receptor:ferritin ratio, increased significantly more in subjects administered FeSO(4) (127 +/- 29 mg; mean +/- SEM) and electrolytic (115 +/- 37 mg), but not the reduced (74 +/- 32 mg) or heme (65 +/- 26 mg) iron forms, compared with those given placebo (2 +/- 19 mg). Based on body iron determinations, retention of the added iron was estimated as 3.0, 2.7, 1.8, and 15.5%, in the 4 iron-treated groups, respectively. Iron treatments did not affect food iron absorption. The 50 mg/d iron treatments increased fecal iron and free radical-generating capacity in vitro, but did not affect fecal water cytotoxicity. In subjects administered FeSO(4), fecal water content was increased slightly but significantly more than in the placebo group. In conclusion, electrolytic iron was approximately 86% as efficacious as FeSO(4) for improving body iron, but the power of this study was insufficient to detect any efficacy of the reduced or heme iron within 12 wk. With modification, this methodology of testing higher levels of food fortification for several weeks in healthy women with low iron stores has the potential for economically assessing the efficiency of iron compounds to improve iron status. PMID:17311950

  20. The production of iron carbide

    SciTech Connect

    Anderson, K.M.; Scheel, J.

    1997-12-31

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

  1. Iron and transfusion medicine.

    PubMed

    Waldvogel-Abramovski, Sophie; Waeber, Grard; 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

  2. Austempered Ductile Iron Machining

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. 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.

  4. Physiology of iron metabolism.

    PubMed

    Waldvogel-Abramowski, Sophie; Waeber, Grard; 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

  5. Physiology of Iron Metabolism

    PubMed Central

    Waldvogel-Abramowski, Sophie; Waeber, Grard; 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

  6. Physics of iron

    NASA Astrophysics Data System (ADS)

    Anderson, O.

    1993-10-01

    This volume comprises papers presented at the AIRAPT Conference, 28 June - 2 July 1993. The iron sessions at the meeting were identified as the Second Ironworkers Convention. The renewal of interest stems from advances in technologies in both diamond-anvil cell (DAC) and shock wave studies as well as from controversies arising from a lack of consensus among both experimentalists and theoreticians. These advances have produced new data on iron in the pressure-temperature regime of interest for phase diagrams and for temperatures of the core/mantle and inner-core/outer-core boundaries. Particularly interesting is the iron phase diagram inferred from DAC studies. A new phase, (beta), with a (gamma)-(beta)-(epsilon) triple point at about 30 GPa and 1190 K, and possible sixth phase, (omega), with an (epsilon)-(Theta)-melt triple point at about 190 GPa and 4000 K are deemed possible. The importance of the equation of state of iron in consideration of Earth's heat budget and the origin of its magnetic field invoke the interest of theoreticians who argue on the basis of molecular dynamics and other first principles methods. While the major thrust of both meetings was on the physics of pure iron, there were notable contributions on iron alloys. Hydrogen-iron alloys, iron-sulfur liquids, and the comparability to rhenium in phase diagram studies are discussed. The knowledge of the physical properties of iron were increased by several contributions.

  7. Iron, Meat and Health

    PubMed Central

    Geissler, Catherine; Singh, Mamta

    2011-01-01

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

  8. 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.

  9. 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

  10. 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

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

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

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

  12. Iron-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.

  13. 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) ...

  14. [Iron deficiency and digestive disorders].

    PubMed

    Cozon, G J N

    2014-11-01

    Iron deficiency anemia still remains problematic worldwide. Iron deficiency without anemia is often undiagnosed. We reviewed, in this study, symptoms and syndromes associated with iron deficiency with or without anemia: fatigue, cognitive functions, restless legs syndrome, hair loss, and chronic heart failure. Iron is absorbed through the digestive tract. Hepcidin and ferroportin are the main proteins of iron regulation. Pathogenic micro-organisms or intestinal dysbiosis are suspected to influence iron absorption. PMID:25282486

  15. 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.

  16. Iron Chelation Therapy

    MedlinePLUS

    ... iron overload. Deferasirox ( Exjade ) . Deferasirox is a newer iron chelating medication that comes in a tablet form. It is dissolved in juice or water and taken (by mouth) once a day. Most patients tolerate it very well, but side effects can include nausea, diarrhea, rash, and more serious ...

  17. 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

  18. Iron studies in hemophilia

    SciTech Connect

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

    1981-12-01

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

  19. Iron piston having selectively hardened ring groove

    SciTech Connect

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

    1987-02-17

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

  20. Iron economy in Chlamydomonas reinhardtii

    PubMed Central

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

    2013-01-01

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

  1. 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:...

  2. 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:...

  3. 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:...

  4. 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:...

  5. 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.

  6. The regulation of iron transport.

    PubMed

    Frazer, David M; Anderson, Gregory J

    2014-01-01

    Iron is an essential nutrient, but its concentration and distribution in the body must be tightly controlled due to its inherent toxicity and insolubility in aqueous solution. Living systems have successfully overcome these potential limitations by evolving a range of iron binding proteins and transport systems that effectively maintain iron in a nontoxic and soluble form for much, if not all, of its time within the body. In the circulation, iron is transported to target organs bound to the serum iron binding protein transferrin. Individual cells modulate their uptake of transferrin-bound iron depending on their iron requirements, using both transferrin receptor 1-dependent and independent pathways. Once inside the cell, iron can be chaperoned to sites of need or, if in excess, stored within ferritin. Iron is released from cells by the iron export protein ferroportin1, which requires the ferroxidase activity of ceruloplasmin or hephestin to load iron safely onto transferrin. The regulation of iron export is controlled predominantly at the systemic level by the master regulator of iron homeostasis hepcidin. Hepcidin, in turn, responds to changes in body iron demand, making use of a range of regulatory mechanisms that center on the bone morphogenetic protein signaling pathway. This review provides an overview of recent advances in the field of iron metabolism and outlines the key components of the iron transport and regulation systems. PMID:24132807

  7. 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....

  8. 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....

  9. Reactive iron in marine sediments

    NASA Technical Reports Server (NTRS)

    Canfield, Donald E.

    1989-01-01

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

  10. 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...

  11. Iron in the brain

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

  12. [Secondary iron overload].

    PubMed

    Galactéros, F

    2000-05-01

    Secondary iron overload (SIO) constitutes a growing clinical problem, particularly in haematological diseases in which the improvements of life expectancy give the iron overload enough duration to play its own prognostic role. Iron may accumulate by two ways: transfusion and/(or) digestive hyperabsorption which is proportional to erythroïd plasma iron turnover. To properly evaluate the iron overloading one must be able to appreciate the cumulative red blood cell transfusion volumes. That is to say: weighting and counting red blood cell units. The magnitude of red blood cell precursor mass might be conveniently but indirectly evaluated by the measurement of the plasma transferrin receptor concentration. The group of haematological diseases, complicated by SIO to the contrary of primary haemochromatosis, is very heterogeneous. Some of them like hereditary dyserythropoiesis may not be obviously detectable on standard haematological observation. They can combine or not with hereditary haemochromatosis. A SIO must be treated when it may add a specific prognostic effect. In some cases, regular blood letting are usable without major problems. In all other cases iron chelation therapy is an effective way to reduce SIO, provided long term compliance is obtained. PMID:10865498

  13. Iron fortification: an update.

    PubMed

    Cook, J D; Reusser, M E

    1983-10-01

    Iron fortification is the optimal approach to reducing the high prevalence of iron deficiency in developing countries. Selection of the iron source entails a compromise between the use of inert compounds which are poorly absorbed and chemically reactive forms with high bioavailability. Although the vehicle and fortification compound must be chosen in tandem because most iron compounds cause discoloration or rancidity, the emphasis in this review is on the food vehicle. Technology for fortifying wheat flour and bread is well established and the use of these vehicles has probably had a significant impact on iron status in Western countries. Recent studies in India indicate that the fortification of common salt is technically feasible and field trials have shown a good hematological response. Similar success has been achieved by fortifying refined sugar with NaFeEDTA in Guatemala. Rice has advantages as a vehicle in those areas where it is the staple food but the technology requires further development. Fish-based condiments have been successfully fortified with NaFeEDTA and show promise as a vehicle in East Asian countries. The fortification of infant foods poses no technical problems and should be encouraged. Additional work is needed to identify other fortification options and to develop targeted fortification programs that will direct iron to those segments of a population in greatest need. PMID:6624707

  14. 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

  15. Topological properties in Iron-Based Superconductors

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  16. [Iron quantification in iron overload disease using MRI].

    PubMed

    Schnnagel, B P; Fischer, R; Nielsen, P; Grosse, R; Adam, G; Yamamura, J

    2013-07-01

    Iron as an essential nutrient is involved in multiple metabolic activities. The importance of a sufficient iron supply is stressed by the fact that, according to WHO data, about 30 % of the global population suffers from iron deficiency and resulting anemia. In contrast, hereditary hemochromatosis is the most common monogeneous inherited disease (prevalence of homozygous genotype 1:200 - 300 in Germany). While iron-induced anemia can be handled by relatively simple diagnostic and therapeutic management, the diagnosis and quantification of organ iron overload is far more challenging. This is of great clinical impact, as the overall body and organ iron concentration is the crucial prognostic parameter in iron overload disease. In 2001 the international workshop of NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) concluded that a quantitative, noninvasive, safe, and accurate approach for the assessment of body iron storage is needed to improve the diagnosis and management of patients with iron overload. PMID:23450372

  17. Isocitrate ameliorates anemia by suppressing the erythroid iron restriction response

    PubMed Central

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

    2013-01-01

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

  18. 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

  19. 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...

  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, 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...

  2. Development of an iron-enriched high-yieldings indica rice cultivar by introgression of a high-iron trait from transgenic iron-biofortified rice.

    PubMed

    Paul, Soumitra; Ali, Nusrat; Datta, Swapan K; Datta, Karabi

    2014-09-01

    Low level of iron in staple food crops is one reason for the predominance of iron-deficiency anemia in developing countries. Most of the iron in rice grains accumulates in the outer aleurone layer and embryo, which are removed during milling, and the edible endosperm contains very low amounts of iron. In an effort to increase iron nutrition, we report here the transgene introgression of a high-iron trait into a high-yielding indica rice cultivar. The ferritin gene from soybean (soyfer1) was introduced into rice plants through interbreeding between soybean ferritin-overexpressing transgenic IR68144 and the high-yielding cultivar Swarna. The stable integration of the soyfer1 gene was confirmed in the BC2F4 generation, and the hybrid seeds showed 2.6-fold soybean ferritin gene expression over the recurrent parent Swarna. The hybrid milled seeds revealed a 2.54-fold increase in iron and 1.54-fold increase in zinc compared to Swarna. Agronomic data and an SSR marker analysis of the hybrid rice plants were taken into account for NIL character identification. PMID:25069855

  3. 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

  4. Iron loading and disease surveillance.

    PubMed Central

    Weinberg, E. D.

    1999-01-01

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

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

    PubMed

    Dahlerup, Jens; Lindgren, Stefan; Moum, Bjrn

    2015-01-01

    Iron deficiency and iron deficiency anemia are global health problems leading to deterioration in patients' quality of life and more serious prognosis in patients with chronic diseases. The cause of iron deficiency and anemia is usually a combination of increased loss and decreased intestinal absorption and delivery from iron stores due to inflammation. Oral iron is first line treatment, but often hampered by intolerance. Intravenous iron is safe, and the preferred treatment in patients with chronic inflammation and bowel diseases. The goal of treatment is normalisation of hemoglobin concentration and recovery of iron stores. It is important to follow up treatment to ensure that these objectives are met and also long-term in patients with chronic iron loss and/or inflammation to avoid recurrence of anemia. PMID:25756711

  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. MRI measures of corpus callosum iron and myelin in early Huntington's disease.

    PubMed

    Di Paola, M; Phillips, O R; Sanchez-Castaneda, C; Di Pardo, A; Maglione, V; Caltagirone, C; Sabatini, U; Squitieri, F

    2014-07-01

    Increased iron in subcortical gray matter (GM) structures of patients with Huntington's disease (HD) has been suggested as a causal factor in neuronal degeneration. But how iron content is related to white matter (WM) changes in HD is still unknown. For example, it is not clear whether WM changes share the same physiopathology (i.e. iron accumulation) with GM or whether there is a different mechanism. The present study used MRI to examine iron content in premanifest gene carriers (PreHD, n = 25) and in early HD patients (n = 25) compared with healthy controls (n = 50). 3T MRI acquisitions included high resolution 3D T1, EPI sequences for diffusion tensor imaging (DTI) as an indirect measure of tissue integrity, and T2*-weighted gradient echo-planar imaging for MR-based relaxometry (R2*), which provides an indirect measure of ferritin/iron deposition in the brain. Myelin breakdown starts in the PreHD stage, but there is no difference in iron content values. Iron content reduction manifests later, in the early HD stage, in which we found a lower R2* parameter value in the isthmus. The WM iron reduction in HD is temporally well-defined (no iron differences in PreHD subjects and iron differences only in early HD patients). Iron level in callosal WM may be regarded as a marker of disease state, as iron does not differentiate PreHD subjects from controls but distinguishes between PreHD and HD. PMID:24895252

  8. Forging the anthropogenic iron cycle.

    PubMed

    Wang, Tao; Mller, Daniel B; Graedel, T E

    2007-07-15

    Metallurgical iron cycles are characterized for four anthropogenic life stages: production, fabrication and manufacturing, use, and waste management and recycling. This analysis is conducted for year 2000 and at three spatial levels: 68 countries and territories, nine world regions, and the planet. Findings include the following: (1) contemporary iron cycles are basically open and substantially dependent on environmental sources and sinks; (2) Asia leads the world regions in iron production and use; Oceania, Latin America and the Caribbean, Africa, and the Commonwealth of Independent States present a highly production-biased iron cycle; (3) purchased scrap contributes a quarter of the global iron and steel production; (4) iron exiting use is three times less than that entering use; (5) about 45% of global iron entering use is devoted to construction, 24% is devoted to transport equipment, and 20% goes to industrial machinery; (6) with respect to international trade of iron ore, iron and steel products, and scrap, 54 out of the 68 countries are net iron importers, while only 14 are net exporters; (7) global iron discharges in tailings, slag, and landfill approximate one-third of the iron mined. Overall, these results provide a foundation for studies of iron-related resource policy, industrial development, and waste and environmental management. PMID:17711233

  9. Iron regulatory proteins and their role in controlling iron metabolism.

    PubMed

    Kühn, Lukas C

    2015-02-01

    Cellular iron homeostasis is regulated by post-transcriptional feedback mechanisms, which control the expression of proteins involved in iron uptake, release and storage. Two cytoplasmic proteins with mRNA-binding properties, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a central role in this regulation. Foremost, IRPs regulate ferritin H and ferritin L translation and thus iron storage, as well as transferrin receptor 1 (TfR1) mRNA stability, thereby adjusting receptor expression and iron uptake via receptor-mediated endocytosis of iron-loaded transferrin. In addition splice variants of iron transporters for import and export at the plasma-membrane, divalent metal transporter 1 (DMT1) and ferroportin are regulated by IRPs. These mechanisms have probably evolved to maintain the cytoplasmic labile iron pool (LIP) at an appropriate level. In certain tissues, the regulation exerted by IRPs influences iron homeostasis and utilization of the entire organism. In intestine, the control of ferritin expression limits intestinal iron absorption and, thus, whole body iron levels. In bone marrow, erythroid heme biosynthesis is coordinated with iron availability through IRP-mediated translational control of erythroid 5-aminolevulinate synthase mRNA. Moreover, the translational control of HIF2α mRNA in kidney by IRP1 coordinates erythropoietin synthesis with iron and oxygen supply. Besides IRPs, body iron absorption is negatively regulated by hepcidin. This peptide hormone, synthesized and secreted by the liver in response to high serum iron, downregulates ferroportin at the protein level and thereby limits iron absorption from the diet. Hepcidin will not be discussed in further detail here. PMID:25306858

  10. 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

  11. 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.

  12. 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 .

  13. Iron deficiency anemia in children.

    PubMed

    Subramaniam, Girish; Girish, Meenakshi

    2015-06-01

    Iron deficiency is not just anemia; it can be responsible for a long list of other manifestations. This topic is of great importance, especially in infancy and early childhood, for a variety of reasons. Firstly, iron need is maximum in this period. Secondly, diet in infancy is usually deficient in iron. Thirdly and most importantly, iron deficiency at this age can result in neurodevelopmental and cognitive deficits, which may not be reversible. Hypochromia and microcytosis in a complete blood count (CBC) makes iron deficiency anemia (IDA) most likely diagnosis. Absence of response to iron should make us look for other differential diagnosis like ? thalassemia trait and anemia of chronic disease. Celiac disease is the most important cause of true IDA not responding to oral iron therapy. While oral ferrous sulphate is the cheapest and most effective therapy for IDA, simple nonpharmacological and pharmacological measures can go a long way in prevention of iron deficiency. PMID:25636824

  14. Iron in Infection and Immunity

    PubMed Central

    Cassat, James E.; Skaar, Eric P.

    2013-01-01

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

  15. Nonbiological fractionation of iron isotopes

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  16. 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.

  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. Iron storage in Mycoplasma capricolum.

    PubMed Central

    Bauminger, E R; Cohen, S G; Labenski de Kanter, F; Levy, A; Ofer, S; Kessel, M; Rottem, S

    1980-01-01

    Considerable quantities or iron were incorporated into the Mycoplasma capricolum cell membrane. Mossbauer studies showed that the iron is in a form which becomes magnetically ordered at low temperatures. The iron-enriched cells contained membrane-bound electron-dense particles of about 6.0 nm in diameter. Images PMID:7354003

  19. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... by any of the following processes: reduced iron, electrolytic iron, and carbonyl iron. (1) Reduced... stable in dry air. (3) Carbonyl iron is prepared by the decomposition of iron pentacarbonyl. It occurs as... shells. It is stable in dry air. (b) Iron, elemental (carbonyl, electrolytic, or reduced) meets...

  20. 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.

  1. Iron, transferrin and myelinogenesis

    NASA Astrophysics Data System (ADS)

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

    2003-09-01

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

  2. 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.

  3. 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)

  4. Iron deficiency anemia

    MedlinePLUS

    ... marrow. Iron-rich foods include: Chicken and turkey Dried lentils, peas, and beans Fish Meats (liver is the highest source) Peanut butter Soybeans Whole-grain bread Other sources include: Oatmeal Raisins, prunes, and apricots Spinach, kale, and other greens

  5. Why nutritional iron deficiency persists as a worldwide problem.

    PubMed

    Lynch, Sean R

    2011-04-01

    The earliest studies of food iron absorption employing biosynthetically incorporated radioisotopes were published in the 1950s. Wheat flour has been fortified with iron in Canada, the United Kingdom, and the United States since the 1940s. However, half a century later, nutritional iron deficiency (ID) is estimated to affect 1.5-2 billion people worldwide. The reasons for the apparently limited impact of health and nutrition policies aimed at reducing the prevalence of ID in developing countries are complex. They include uncertainty about the actual prevalence of ID, particularly in regions where malaria and other infections are endemic, failure of policy makers to recognize the relationships between ID and both impaired productivity and increased morbidity, concerns about safety and the risks to iron-sufficient individuals if mass fortification is introduced, and technical obstacles that make it difficult to add bioavailable iron to the diets of those at greatest risk. It is, however, likely that the next decade will see a marked reduction in the prevalence of ID worldwide. More specific assessment tools are being standardized and applied to population surveys. The importance of preventing ID during critical periods of the life cycle is receiving increased attention. Innovative approaches to the delivery of bioavailable iron have been shown to be efficacious. The importance of integrating strategies to improve iron nutrition with other health measures, and economic and social policies addressing poverty as well as trade and agriculture, are receiving increasing consideration. PMID:21367937

  6. Iron Aluminide Composites

    SciTech Connect

    Schneibel, J.H.

    1998-11-20

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

  7. Effect of dietary iron source and iron status on iron bioavailability tests in the rat

    SciTech Connect

    Zhang, D.; Hendricks, D.G.; Mahoney, A.W.

    1986-03-05

    Weanling male rats were made anemic in 7 days by feeding a low iron diet and bleeding. Healthy rats were fed the low iron diet supplemented with ferrous sulfate (29 ppm Fe). Each group was subdivided and fed for 10 days on test diets containing about 29 ppm iron that were formulated with meat:spinach mixtures or meat:soy mixtures to provided 100:0, 75:25, 50:50, 25:75, or 0:100% of the dietary iron from these sources or from a ferrous sulfate diet. After 3 days on the diets all rats were dosed orally with 2 or 5 micro curries of /sup 59/Fe after a 18 hour fast and refeeding for 1.5 hours. Iron status influenced liver iron, carcass iron, liver radio activity and percent of radioactive dose retained. Diet influenced fecal iron and apparent absorption of iron. In iron bioavailability studies assessment methodology and iron status of the test subject greatly influences the estimates of the value of dietary sources of iron.

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  12. [Intravenous iron in general surgery].

    PubMed

    Serrablo, Alejandro; Urbieta, Elena; Carceln-Andrs, Josefa; Ruiz, Jaime; Rodrigo, Javier; Izuel, Mnica; Garca-Erce, Jos

    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

  13. Radiogenic Lead in Iron Meteorites Revisited

    NASA Astrophysics Data System (ADS)

    Schoenberg, R.; Kamber, B. S.; Collerson, K. D.

    2001-12-01

    Lead in iron meteorites has long been known to be of surprisingly radiogenic isotope composition (e.g. [1-3]). Primordial Pb is only found (if at all) after very extensive leaching of the samples in strong mineral acids. The widely accepted explanation for this observation is that Pb of radiogenic composition represents terrestrial contamination, although the exact source and mode of contamination have eluded the isotope geochemists. In the most recent study (with the lowest laboratory blanks) Gpel et al. [3] found that leachates and residues of progressively leached group IAB iron meteorites (Canyon Diablo, Toluca and Odessa) have, within analytical uncertainty, identical radiogenic and primordial Pb isotope components. The combined data yield an apparent regression age of 4534+/-8 Ma, identical to the Ar-Ar plateau age of the winonaite Pontlifny (4531+/-12 Ma; [4]), which is believed to represent the silicate counterpart to IAB iron meteorites. We will present high precision MC-ICPMS Pb-isotope data for eight progressively leached magmatic and non-magmatic iron meteorites, as well as Pb-isotopes and rare earth element patterns of bulk dissolutions of iron meteorites. All leachates and bulk dissolutions of the different iron meteorites (excluding the non-magmatic group IAB representatives) display excellent colinearity in the common lead isotope diagram. The slope of the regression line corresponds to an apparent age of 4568.5+/-4.6 Ma, within uncertainty equal to the Pb/Pb age of Ca-Al rich inclusions in the carbonaceous chondrite Allende [5]. Excellent colinearity of Pb data is also found in thorogenic Pb space, where the slope of the regression line corresponds to a ? -value of 3.816+/-29, which is equal to that of chondritic meteorites (i.e. 3.806+/-88) but different from average continental crust. Data for individual IAB meteorites also define excellent colinearity but yield somewhat younger apparent ages. For example, the regression date for our Canon Diablo leachates is 4546.5+/-7.6 Ma, within uncertainties identical to that of Gpel et al. [3]. Chondrite normalized rare earth element patterns of unleached bulk samples of iron meteorites prove absence of terrestrial contamination. Probability for selective contamination of iron meteorites with terrestrial Pb was calculated by comparison with different terrestrial data pools. For a single contamination event of all studied samples with average terrestrial lead the probability is 0.69%. Individual contamination for the different iron meteorites yields a probability as low as 0.0048%. Low probabilities of contamination reflect the well-known observation that the accessible Earth plots well to the left of the meteorite isochron in common Pb space (i.e. the first Pb-isotope paradox) and that average continental crust (and sediment) has a higher time-integrated Th/U ratio than chondritic meteorites. In view of the consistency in Pb-isotope composition of the radiogenic component in iron meteorites, the lack of contamination of other trace elements, and low estimated probabilities for terrestrial contamination we propose to reconsider the possibility of in situ grown (though now largely unsupported) radiogenic lead in iron meteorites. Implications for early planetary evolution and core formation will be discussed. [1] Oversby, V.M. (1970), Geochim. Cosmochim. Acta 34, 65. [2] Chen, J.H. and Wasserburg, G.J. (1983), Geochim. Cosmochim. Acta 47, 1725. [3] Gpel et al. (1985), Geochim. Cosmochim. Acta 49, 1681. [4] Benedix et al. (1998), Geochim. Cosmochim. Acta 62, 2535. [5] Manhs et al. (1988), Geochim. Cosmochim. Acta 69-70, 32.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  15. A protective role for zinc on intestinal peroxidative damage during oral iron repletion.

    PubMed

    Sreedhar, B; Subramaniyan, R; Nair, K Madhavan

    2004-06-11

    Oral iron-supplementation is a general practice to correct iron deficiency anemia. Exposure of iron-deficient intestine to large doses of iron is known to induce oxidative damage, leading to loss of functional integrity, and reduced mucosal cell turnover. Conditioning of intestine with anti-oxidants during iron administration was shown to suppress iron-induced oxidative damage. Zinc is known to protect cells from peroxidative damage by inducing metallothionein and maintaining the sulfhydryl group stability. Nevertheless, co-administration of iron and zinc may antagonize each other with respect to absorption. In the present study, we show that combined supplementation of iron and zinc though marginally inhibits iron uptake significantly attenuates the oxidative stress by induction of metallothionein and elevating the levels of GSH. Further, presence of zinc in situ reduced the iron-induced hydroxyl radical production in the intestinal mucosa, as assessed by EPR spectroscopy. These results strongly suggest a protective role for zinc on iron-induced oxidative stress, which might have implications in anemia control programs. PMID:15147971

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

    PubMed

    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. PMID:12940417

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

    PubMed Central

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

    2014-01-01

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

  18. VISUALIZING IRON IN MULTIPLE SCLEROSIS

    PubMed Central

    Bagnato, Francesca; Hametner, Simon; Welch, Edward Brian

    2012-01-01

    Magnetic resonance imaging (MRI) protocols that are designed to be sensitive to iron typically take advantage of (1) iron effects on the relaxation of water protons and/or (2) iron-induced local magnetic field susceptibility changes. Increasing evidence sustains the notion that imaging iron in brain of patients with multiple sclerosis (MS) may add some specificity toward the identification of the disease pathology. The present review summarizes currently reported in vivo and post mortem MRI evidence of (1) iron detection in white matter and grey matter of MS brains, (2) pathological and physiological correlates of iron as disclosed by imaging and (3) relations between iron accumulation and disease progression as measured by clinical metrics. PMID:23347601

  19. 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.

  20. 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

  1. Degradation of chlorofluorocarbons using granular iron and bimetallic irons

    NASA Astrophysics Data System (ADS)

    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.

  2. 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.

  3. 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.

  4. 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

  5. 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

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

    PubMed Central

    Brock, T D; Gustafson, J

    1976-01-01

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

  7. 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...

  8. Effect of confinement in carbon nanotubes on the activity of Fischer-Tropsch iron catalyst.

    PubMed

    Chen, Wei; Fan, Zhongli; Pan, Xiulian; Bao, Xinhe

    2008-07-23

    Following our previous findings that confinement within carbon nanotubes (CNTs) can modify the redox properties of encapsulated iron oxides, we demonstrate here how this can affect the catalytic reactivity of iron catalysts in Fischer-Tropsch synthesis (FTS). The investigation, using in situ XRD under conditions close to the reaction conditions, reveals that the distribution of iron carbide and oxide phases is modulated in the CNT-confined system. The iron species encapsulated inside CNTs prefer to exist in a more reduced state, tending to form more iron carbides under the reaction conditions, which have been recognized to be essential to obtain high FTS activity. The relative ratio of the integral XRD peaks of iron carbide (Fe(x)C(y)) to oxide (FeO) is about 4.7 for the encapsulated iron catalyst in comparison to 2.4 for the iron catalyst dispersed on the outer walls of CNTs under the same conditions. This causes a remarkable modification of the catalytic performance. The yield of C5+ hydrocarbons over the encapsulated iron catalyst is twice that over iron catalyst outside CNTs and more than 6 times that over activated-carbon-supported iron catalyst. The catalytic activity enhancement is attributed to the effect of confinement of the iron catalyst within the CNT channels. As demonstrated by temperature-programmed reduction in H2 and in CO atmospheres, the reducibility of the iron species is significantly improved when they are confined. The ability to modify the redox properties via confinement in CNTs is expected to be of significance for many catalytic reactions, which are highly dependent on the redox state of the active components. Furthermore, diffusion and aggregation of the iron species through the reduction and reaction have been observed, but these are retarded inside CNTs due to the spatial restriction of the channels. PMID:18576652

  9. Iron absorption and transport-an update.

    PubMed

    Conrad, M E; Umbreit, J N

    2000-08-01

    Iron is vital for all living organisms. However, excess iron is hazardous because it produces free radical formation. Therefore, iron absorption is carefully regulated to maintain an equilibrium between absorption and body loss of iron. In countries where heme is a significant part of the diet, most body iron is derived from dietary heme iron because heme binds few of the luminal intestinal iron chelators that inhibit absorption of non-heme iron. Uptake of luminal heme into enterocytes occurs as a metalloporphyrin. Intracellularly, iron is released from heme by heme oxygenase so that iron leaves the enterocyte to enter the plasma as non-heme iron. Ferric iron is absorbed via a beta(3) integrin and mobilferrin (IMP) pathway that is not shared with other nutritional metals. Ferrous iron uptake is facilitated by DMT-1 (Nramp-2, DCT-1) in a pathway shared with manganese. Other proteins were recently described which are believed to play a role in iron absorption. SFT (Stimulator of Iron Transport) is postulated to facilitate both ferric and ferrous iron uptake, and Hephaestin is thought to be important in transfer of iron from enterocytes into the plasma. The iron concentration within enterocytes reflects the total body iron and either upregulates or satiates iron-binding sites on regulatory proteins. Enterocytes of hemochromatotics are iron-depleted similarly to the absorptive cells of iron-deficient subjects. Iron depletion, hemolysis, and hypoxia each can stimulate iron absorption. In non-intestinal cells most iron uptake occurs via either the classical clathrin-coated pathway utilizing transferrin receptors or the poorly defined transferrin receptor independent pathway. Non-intestinal cells possess the IMP and DMT-1 pathways though their role in the absence of iron overload is unclear. This suggests that these pathways have intracellular functions in addition to facilitating iron uptake. PMID:10911382

  10. Glutaredoxins: roles in iron homeostasis

    PubMed Central

    Rouhier, Nicolas; Couturier, Jeremy; Johnson, Michael K.; Jacquot, Jean-Pierre

    2009-01-01

    Glutaredoxins, proteins traditionally involved in redox reactions, are also required for ironsulphur cluster assembly and haem biosynthesis. These new roles are likely related to the ability of some glutaredoxins to bind labile [2Fe2S] clusters and to transfer them rapidly and efficiently to acceptor proteins. Recent results point to putative roles for glutaredoxins in the sensing of cellular iron and in ironsulphur cluster biogenesis, either as scaffold proteins for the de novo synthesis of ironsulphur clusters or as carrier proteins for the transfer of preformed ironsulphur clusters. Based on prokaryote genome analysis and in vivo studies of iron regulation in yeast, we propose putative new roles and binding partners for glutaredoxins in the assembly of metalloproteins. PMID:19811920

  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. Microbial reduction of iron ore

    DOEpatents

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

    1989-01-01

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

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

    PubMed

    Emerson, David

    2015-01-01

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

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

    PubMed Central

    Emerson, David

    2016-01-01

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

  15. 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.

  16. 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.

  17. Isotopic, petrologic and biogeochemical investigations of banded iron-formations

    NASA Technical Reports Server (NTRS)

    Hayes, J. M.; Kaufman, A. J.; Klein, C.; Studley, S. A.; Baur, M. E.; Walter, M. R.

    1986-01-01

    It is recognized that the first occurrence of banded iron-formations (BIFs) clearly predates biological oxygenation of the atmosphere-hydrosphere system and that their last occurrences extend beyond plausible dates of pervasive biological oxygenation. For this reason, and because enormous quantities of oxidizing power have been sequestered in them, it is widely thought that these massive, but enigmatic, sediments must encode information about the mechanism and timing of the rise of atmospheric O2. By coupling isotopic analyses of iron-formation carbonates with biogeochemical and petrologic investigations, we are studying (1) the mechanism of initial sedimentation of iron; (2) the role of iron in microbially mediated diagenetic processes in fresh iron-formation sediments; and (3) the logical integration of mechanisms of deposition with observed levels of banding. Thus far, it has been shown that (1) carbonates in BIFs of the Hamersley Group of Western Australia are isotopically inhomogenous; (2) the nature and pattern of isotopic ordering is not consistent with a metamorphic origin for the overall depletion of C-13 observed in the carbonates; (3) if biological, the origin of the C-13 depleted carbonate could be either respiratory or fermentative; (4) iron may have been precipitate d as Fe(3+), then reduced to Fe(2+) within the sediment; and (5) sedimentary biogeochemical systems may have been at least partially closed to mass transport of carbonate species.

  18. 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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  1. Therapeutic iron restriction in sepsis.

    PubMed

    Xia, Yanfang; Farah, Nizam; Maxan, Alexander; Zhou, Juan; Lehmann, Christian

    2016-04-01

    Sepsis represents the systemic immune response to an infection. Mortality of sepsis slightly decreased over the past years, but due to the growing incidence, the absolute number of deaths still increases and belongs to the three most frequent causes of death worldwide. To date, there is no specific treatment for sepsis available yet. Iron is essential to both human beings and microbes and of great significance in many physiological and biochemical processes. Since iron is involved in the bacterial proliferation and immune dysregulation, we hypothesize that restricting host iron levels by application of iron chelators attenuates bacterial growth and improves the detrimental dysregulation of the systemic immune response in sepsis. PMID:26968906

  2. Replacing London's cast iron mains

    SciTech Connect

    Thorne, A. ); Mathews, P. )

    1992-07-01

    This paper discusses the cast iron gas distribution systems that exist in many cities and contains considerable amounts of pipe that vary in age from 20 to 150 years. In many ways, cast iron is an excellent material. It is inherently corrosion resistant, easy to install and cheap. However, it is also brittle and smaller diameter cast iron pipe has a relatively low beam strength. This can lead, under some circumstances, to failure without external warning, with typically a full-circumferential failure. In congested areas this can lead to serious consequences. As a result, cast iron replacement programs are a common feature in such urban gas distribution systems.

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

    PubMed

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

    2014-04-01

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

  4. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... line which extends through the building wall must be of steel pipe. (c) A cast iron or ductile iron... 49 Transportation 3 2011-10-01 2011-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile...

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

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

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

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

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

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

  7. Iron and iron-related proteins in asbestosis.

    EPA Science Inventory

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

  8. Nanosized Iron Oxide Colloids Strongly Enhance Microbial Iron Reduction?

    PubMed Central

    Bosch, Julian; Heister, Katja; Hofmann, Thilo; Meckenstock, Rainer U.

    2010-01-01

    Microbial iron reduction is considered to be a significant subsurface process. The rate-limiting bioavailability of the insoluble iron oxyhydroxides, however, is a topic for debate. Surface area and mineral structure are recognized as crucial parameters for microbial reduction rates of bulk, macroaggregate iron minerals. However, a significant fraction of iron oxide minerals in the subsurface is supposed to be present as nanosized colloids. We therefore studied the role of colloidal iron oxides in microbial iron reduction. In batch growth experiments with Geobacter sulfurreducens, colloids of ferrihydrite (hydrodynamic diameter, 336 nm), hematite (123 nm), goethite (157 nm), and akaganeite (64 nm) were added as electron acceptors. The colloidal iron oxides were reduced up to 2 orders of magnitude more rapidly (up to 1,255 pmol h?1 cell?1) than bulk macroaggregates of the same iron phases (6 to 70 pmol h?1 cell?1). The increased reactivity was not only due to the large surface areas of the colloidal aggregates but also was due to a higher reactivity per unit surface. We hypothesize that this can be attributed to the high bioavailability of the nanosized aggregates and their colloidal suspension. Furthermore, a strong enhancement of reduction rates of bulk ferrihydrite was observed when nanosized ferrihydrite aggregates were added. PMID:19915036

  9. IRON RELEASE AND COLORED WATER FORMATION FROM IRON SCALES

    EPA Science Inventory

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

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

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

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

  11. Iron-Deficiency Anemia (For Parents)

    MedlinePLUS

    ... Your Child All About Food Allergies Iron-Deficiency Anemia KidsHealth > For Parents > Iron-Deficiency Anemia Print A ... common nutritional deficiency in children. About Iron-Deficiency Anemia Every red blood cell in the body contains ...

  12. 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

  13. Genetics Home Reference: African iron overload

    MedlinePLUS

    ... high in iron. It is particularly associated with consumption of a traditional African beer that contains dissolved ... to some combination of differences in dietary iron consumption and gender differences in the processing of iron. ...

  14. 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 ...

  15. An international registry for neurodegeneration with brain iron accumulation

    PubMed Central

    2012-01-01

    We report the development of an international registry for Neurodegeneration with Brain Iron Accumulation (NBIA), in the context of TIRCON (Treat Iron-Related Childhood-Onset Neurodegeneration), an EU-FP7 – funded project. This registry aims to combine scattered resources, integrate clinical and scientific knowledge, and generate a rich source for future research studies. This paper describes the content, architecture and future utility of the registry with the intent to capture as many NBIA patients as possible and to offer comprehensive information to the international scientific community. PMID:22985983

  16. 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.

  17. Iron around the clock.

    PubMed

    Tissot, Nicolas; Przybyla-Toscano, Jonathan; Reyt, Guilhem; Castel, Baptiste; Duc, Cline; Boucherez, Jossia; Gaymard, Frdric; Briat, Jean-Franois; 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

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. Iron biomineralization by anaerobic neutrophilic iron-oxidizing bacteria

    NASA Astrophysics Data System (ADS)

    Miot, Jennyfer; Benzerara, Karim; Morin, Guillaume; Kappler, Andreas; Bernard, Sylvain; Obst, Martin; Frard, Cline; Skouri-Panet, Friel; Guigner, Jean-Michel; Posth, Nicole; Galvez, Matthieu; Brown, Gordon E., Jr.; Guyot, Franois

    2009-02-01

    Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent iron-oxidizing bacterium Acidovorax sp. strain BoFeN1 in the presence of dissolved Fe(II) using electron microscopy and Scanning Transmission X-ray Microscopy (STXM). All detected minerals consisted mainly of amorphous iron phosphates, but based on their morphology and localization, three types of precipitates could be discriminated: (1) mineralized filaments at distance from the cells, (2) globules of 100 25 nm in diameter, at the cell surface and (3) a 40-nm thick mineralized layer within the periplasm. All of those phases were shown to be intimately associated with organic molecules. Periplasmic encrustation was accompanied by an accumulation of protein moieties. In the same way, exopolysaccharides were associated with the extracellular mineralized filaments. The evolution of cell encrustation was followed by TEM over the time course of a culture: cell encrustation proceeded progressively, with rapid precipitation in the periplasm (in a few tens of minutes), followed by the formation of surface-bound globules. Moreover, we frequently observed an asymmetric mineral thickening at the cell poles. In parallel, the evolution of iron oxidation was quantified by STXM: iron both contained in the bacteria and in the extracellular precipitates reached complete oxidation within 6 days. While a progressive oxidation of Fe in the bacteria and in the medium could be observed, spatial redox (oxido-reduction state) heterogeneities were detected at the cell poles and in the extracellular precipitates after 1 day. All these findings provide new information to further the understanding of molecular processes involved in iron biomineralization by anaerobic iron-oxidizing bacteria and offer potential signatures of those metabolisms that can be looked for in the geological record.

  7. 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.

  8. Iron: the new advances in therapy.

    PubMed

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

    2013-03-01

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

  9. Iron and Neurodegeneration in Multiple Sclerosis

    PubMed Central

    Khalil, Michael; Teunissen, Charlotte; Langkammer, Christian

    2011-01-01

    Increased iron deposition might be implicated in multiple sclerosis (MS). Recent development of MRI enabled to determine brain iron levels in a quantitative manner, which has put more interest on studying the role of iron in MS. Evidence for abnormal iron homeostasis in MS comes also from analyses of iron and iron-related proteins in CSF and blood and postmortem MS brain sections. However, it is not yet clear if iron accumulation is implicated in MS pathology or merely reflects an epiphenomenon. Further interest has been generated by the idea of chronic cerebrospinal venous insufficiency that might be associated with brain iron accumulation due to a reduction in venous outflow, but its existence and etiologic role in MS are currently controversially debated. In future studies, combined approaches applying quantitative MRI together with CSF and serum analyses of iron and iron-related proteins in a clinical followup setting might help to elucidate the implication of iron accumulation in MS. PMID:22096640

  10. 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

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

  11. 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

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

  12. 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

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

  13. 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

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

  14. 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

  15. Iron-induced thrombocytopenia in severe iron-deficiency anemia.

    PubMed

    Cunha, Vitria; Ferreira, Melanie; Barosa, Rita; Fonseca, Ana Glria; Delerue, Francisca; Carvalho, Carla

    2015-04-01

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

  16. 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

  17. Phonons in iron monolayers

    NASA Astrophysics Data System (ADS)

    Stankov, S.; Sladecek, M.; ?lezak, T.; ?a?ewski, J.; Rhlsberger, R.; Sepiol, B.; Vogl, G.; Chumakov, A. I.; Rffer, R.; Spiridis, N.; Zajac, M.; ?lezak, M.; Parli?ski, K.; Korecki, J.

    2010-03-01

    The systematic investigation of the lattice dynamics from bulk to a single atomic layer of material was a great experimental challenge until now. Recently, nuclear inelastic scattering has been introduced as a unique technique capable of determining the density of phonon states of nanoscale materials in-situ with a depth resolution of one atomic layer. This became possible by setting up a dedicated ultrahigh vacuum system for samples growth and characterization directly at the nuclear resonance beamline ID18 of the ESRF. The new instrument allowed for systematic investigation of the evolution of the density of phonon states of iron from the bulk to a single atomic layer. The isotopic selectivity of the nuclear resonance absorption was employed to experimentally determine the atomic vibrations at and near the Fe(110) surface with a monolayer sensitivity. The experimental achievements stimulated a rapid progress of the ab-initio calculations of surface phonons.

  18. 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.

  19. Weldability of iron aluminides

    SciTech Connect

    Zacharia, T.; David, S.A.

    1991-01-01

    Improvements in the ductility of iron aluminide alloys, achieved through control of composition and microstructure, has led to growing interest in using these materials for structural applications. weldability is a key issues in the utilization of these alloys for structural components. This paper describes the welding and welding behavior of an Fe{sub 3}Al alloy (FA-129) containing niobium and carbon. Weldability of this alloy has been found to be a strong function of composition, welding process and processing conditions. Crack free welds were made on both sheet and plate material using the electron beam (EB) welding process. Gas tungsten arc (GTA) welds, on the other hand, exhibited a tendency for delayed cold cracking. However, the study clearly demonstrated that successful welds can be made using matching filler metal and proper choice of processing conditions. 15 ref., 5 figs.

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

    PubMed

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

    2015-01-24

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

  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. 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.

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

    PubMed

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

    2016-02-01

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

  4. Iron-Carbonyl Aqueous Vesicles (MCsomes) by Hydration of [Fe(CO){CO(CH2 )5 CH3 }(Cp)(PPh3 )] (FpC6): Highly Integrated Colloids with Aggregation-Induced Self-Enhanced IR Absorption (AI-SEIRA).

    PubMed

    Murshid, Nimer; Wang, Xiaosong

    2015-12-21

    Self-assembly of hydrophobic molecules into aqueous colloids contradicts common chemical intuition, but has been achieved through hydration of [Fe(CO){CO(CH2 )5 CH3 }(Cp)(PPh3 )] (FpC6). FpC6 has no surface activity, no NMR signals in D2 O and no critical aggregation concentration (CAC) in H2 O. The molecule, however, contains both acyl and terminal CO groups that are prone to being hydrated. By adding water to a solution in THF, self-assembly of FpC6 can be initiated through water-carbonyl interactions (WCIs) with the highly polarized acyl CO groups. This aggregation subsequently enhances the hydration of the acyl CO groups and also induces the WCI of otherwise unhydrated terminal CO groups. The resultant metal-carbonyl aggregates have been proved to be bilayer vesicles with iron complexes exposed towards water and alkyl chains forming inner walls (MCsomes). These MCsomes show high structure integration upon dilution due to the hydrophobic nature of the building blocks. The highly polarized CO groups on the surface of the MCsomes result in a negative zeta potential (-65?mV) and create a local electric field, which significantly enhances the IR absorption of CO groups by more than 100-fold. This is the first discovery of aggregation-induced self-enhanced IR absorption (AI-SRIRA) without the assistant of external dielectric substrates. Highly integrated MCsomes are, therefore, promising as a novel group of materials, for example, for IR-based sensing and imaging. PMID:26563745

  5. Iron homeostasis in the neonate.

    PubMed

    Collard, Keith J

    2009-04-01

    The regulation of the availability of micronutrients is particularly critical during periods of rapid growth and differentiation such as the fetal and neonatal stages. Both iron deficiency and excess during the early weeks of life can have severe effects on neurodevelopment that may persist into adulthood and may not be corrected by restoration of normal iron levels. This article provides a succinct overview of our current understanding of the extent to which newborns, particularly premature newborns, are able (or not able) to regulate their iron status according to physiologic need. Postnatal development of factors important to iron homeostasis such as intestinal transport, extracellular transport, cellular uptake and storage, intracellular regulation, and systemic control are examined. Also reviewed are how factors peculiar to the sick and premature neonate can further adversely influence iron homeostasis and exacerbate iron-induced oxidative stress, predispose the infant to bacterial infections, and, thus, compromise his or her clinical situation further. The article concludes with a discussion of the areas of relative ignorance that require urgent investigation to rectify our lack of understanding of iron homeostasis in what is a critical stage of development. PMID:19336381

  6. Iron homeostasis in breast cancer.

    PubMed

    Marques, Oriana; da Silva, Berta Martins; Porto, Graa; 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. Cellular and mitochondrial remodeling upon defects in iron-sulfur protein biogenesis.

    PubMed

    Hausmann, Anja; Samans, Birgit; Lill, Roland; Mhlenhoff, 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

  8. Fetal and neonatal iron deficiency causes volume loss and alters the neurochemical profile of the adult rat hippocampus

    PubMed Central

    Rao, Raghavendra; Tkac, Ivan; Schmidt, Adam T.; Georgieff, Michael K.

    2011-01-01

    Objective Perinatal iron deficiency results in persistent hippocampus-based cognitive deficits in adulthood despite iron supplementation. The objective of the present study was to determine the long-term effects of perinatal iron deficiency and its treatment on hippocampal anatomy and neurochemistry in formerly iron-deficient young adult rats. Methods Perinatal iron deficiency was induced using a low-iron diet during gestation and the first postnatal week in male rats. Hippocampal size was determined using volumetric magnetic resonance imaging at 8 weeks of age. Hippocampal neurochemical profile, consisting of 17 metabolites indexing neuronal and glial integrity, energy reserves, amino acids, and myelination, was quantified using high-field in vivo 1H NMR spectroscopy at 9.4 T (N = 11) and compared with iron-sufficient control group (N = 10). Results The brain iron concentration was 56% lower than the control group at 7 days of age in the iron-deficient group, but had recovered completely at 8 weeks. The cross-sectional area of the hippocampus was decreased by 12% in the formerly iron-deficient group (P = 0.0002). The hippocampal neurochemical profile was altered: relative to the control group, creatine, lactate, N-acetylaspartylglutamate, and taurine concentrations were 629% lower, and glutamine concentration 18% higher in the formerly iron-deficient hippocampus (P < 0.05). Discussion Perinatal iron deficiency was associated with reduced hippocampal size and altered neurochemistry in adulthood, despite correction of brain iron deficiency. The neurochemical changes suggest suppressed energy metabolism, neuronal activity, and plasticity in the formerly iron-deficient hippocampus. These anatomic and neurochemical changes are consistent with previous structural and behavioral studies demonstrating long-term hippocampal dysfunction following perinatal iron deficiency. PMID:21605501

  9. 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.

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

    PubMed

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

    2006-04-20

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

  11. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  13. 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.

  14. [Phosphate metabolism and iron deficiency].

    PubMed

    Yokoyama, Keitaro

    2016-02-01

    Autosomal dominant hypophosphatemic rickets(ADHR)is caused by gain-of-function mutations in FGF23 that prevent its proteolytic cleavage. Fibroblast growth factor 23(FGF23)is a hormone that inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D biosynthesis. Low iron status plays a role in the pathophysiology of ADHR. Iron deficiency is an environmental trigger that stimulates FGF23 expression and hypophosphatemia in ADHR. It was reported that FGF23 elevation in patients with CKD, who are often iron deficient. In patients with nondialysis-dependent CKD, treatment with ferric citrate hydrate resulted in significant reductions in serum phosphate and FGF23. PMID:26813504

  15. Magnetic study of iron sorbitol

    NASA Astrophysics Data System (ADS)

    Lzaro, F. J.; Larrea, A.; Abada, A. R.; Romero, M. S.

    2002-09-01

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

  16. Macrophage iron, hepcidin, and atherosclerotic plaque stability.

    PubMed

    Sullivan, Jerome L

    2007-09-01

    Hepcidin has emerged as the key hormone in the regulation of iron balance and recycling. Elevated levels increase iron in macrophages and inhibit gastrointestinal iron uptake. The physiology of hepcidin suggests an additional mechanism by which iron depletion could protect against atherosclerotic lesion progression. Without hepcidin, macrophages retain less iron. Very low hepcidin levels occur in iron deficiency anemia and also in homozygous hemochromatosis. There is defective retention of iron in macrophages in hemochromatosis and also evidently no increase in atherosclerosis in this disorder. In normal subjects with intact hepcidin responses, atherosclerotic plaque has been reported to have roughly an order of magnitude higher iron concentration than that in healthy arterial wall. Hepcidin may promote plaque destabilization by preventing iron mobilization from macrophages within atherosclerotic lesions; the absence of this mobilization may result in increased cellular iron loads, lipid peroxidation, and progression to foam cells. Marked downregulation of hepcidin (e.g., by induction of iron deficiency anemia) could accelerate iron loss from intralesional macrophages. It is proposed that the minimally proatherogenic level of hepcidin is near the low levels associated with iron deficiency anemia or homozygous hemochromatosis. Induced iron deficiency anemia intensely mobilizes macrophage iron throughout the body to support erythropoiesis. Macrophage iron in the interior of atherosclerotic plaques is not exempt from this process. Decreases in both intralesional iron and lesion size by systemic iron reduction have been shown in animal studies. It remains to be confirmed in humans that a period of systemic iron depletion can decrease lesion size and increase lesion stability as demonstrated in animal studies. The proposed effects of hepcidin and iron in plaque progression offer an explanation of the paradox of no increase in atherosclerosis in patients with hemochromatosis despite a key role of iron in atherogenesis in normal subjects. PMID:17720947

  17. 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 (145.700.74 ug/g); however, it is usually reported as an inhibitor of iron absorption...

  18. 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...

  19. 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...

  20. 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. ...

  1. 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....

  2. 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.

  3. 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.

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

    PubMed

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

    2014-01-01

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

  5. Reductive iron assimilation and intracellular siderophores assist extracellular siderophore-driven iron homeostasis and virulence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Iron is an essential nutrient and prudent iron acquisition and management are key traits of a successful pathogen. Fungi use nonribosomally synthesized secreted iron chelators (siderophores) or Reductive Iron Assimilation (RIA) mechanisms to acquire iron in a high affinity manner. Previous studies...

  6. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Service lines: Connections to cast iron or ductile... Customer Meters, Service Regulators, and Service Lines 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line connected to a cast iron or ductile iron main must be...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  9. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2012-10-01 2012-10-01 false Remedial measures: Cast iron and ductile...

  10. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2011-10-01 2011-10-01 false Remedial measures: Cast iron and ductile...

  11. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2013-10-01 2013-10-01 false Remedial measures: Cast iron and ductile...

  12. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2014-10-01 2014-10-01 false Remedial measures: Cast iron and ductile...

  13. 49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2010-10-01 2010-10-01 false Remedial measures: Cast iron and ductile...

  14. 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

  15. 49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Connections to cast iron or ductile... Customer Meters, Service Regulators, and Service Lines 192.369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line connected to a cast iron or ductile iron main must be...

  16. Iron deficiency anemia in heart failure.

    PubMed

    Arora, Natasha P; Ghali, Jalal K

    2013-07-01

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

  17. Iron in fetal and neonatal nutrition

    PubMed Central

    Rao, Raghavendra; Georgieff, Michael K.

    2007-01-01

    Summary Both iron deficiency and iron excess during the fetal and neonatal period bode poorly for developing organ systems. Maternal conditions such as iron deficiency, diabetes mellitus, hypertension and smoking, and preterm birth are the common causes of perinatal iron deficiency. Long-term neurodevelopmental impairments and predisposition to future iron deficiency that are prevalent in infants with perinatal iron deficiency require early diagnosis, optimal treatment and adequate follow-up of infants at risk for the condition. However, due to the potential for oxidant-mediated tissue injury, iron overload should be avoided in the perinatal period, especially in preterm infants. PMID:17157088

  18. Iron homeostasis in host defence and inflammation

    PubMed Central

    Ganz, Tomas; Nemeth, Elizabeta

    2016-01-01

    Iron is an essential trace element for multicellular organisms and nearly all microorganisms. Although iron is abundant in the environment, common forms of iron are minimally soluble and therefore poorly accessible to biological organisms. Microorganisms entering a mammalian host face multiple mechanisms that further restrict their ability to obtain iron and thereby limit their pathogenicity. Iron levels also modulate host defence, as iron content in macrophages regulates their cytokine production. Here, we review recent advances that highlight the role of systemic and cellular iron-regulating mechanisms in protecting hosts from infection, emphasizing aspects that are applicable to human health and disease. PMID:26160612

  19. There is iron and iron Burkinab womens 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 womens 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 Moor 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 irons 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 womens 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

  20. Mitochondrial iron transport and homeostasis in plants

    PubMed Central

    Jain, Anshika; Connolly, Erin L.

    2013-01-01

    Iron (Fe) is an essential nutrient for plants and although the mechanisms controlling iron uptake from the soil are relatively well understood, comparatively little is known about subcellular trafficking of iron in plant cells. Mitochondria represent a significant iron sink within cells, as iron is required for the proper functioning of respiratory chain protein complexes. Mitochondria are a site of FeS cluster synthesis, and possibly heme synthesis as well. Here we review recent insights into the molecular mechanisms controlling mitochondrial iron transport and homeostasis. We focus on the recent identification of a mitochondrial iron uptake transporter in rice and a possible role for metalloreductases in iron uptake by mitochondria. In addition, we highlight recent advances in mitochondrial iron homeostasis with an emphasis on the roles of frataxin and ferritin in iron trafficking and storage within mitochondria. PMID:24046773

  1. 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

  2. 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.

  3. Thermal hazard of iron picrate.

    PubMed

    Akiyoshi, Miyako; Okada, Ken; Matsunaga, Takehiro

    2006-05-20

    Iron picrate (FePic) was synthesized under conditions similar to those that result in the natural deterioration of chemical weapons. Its thermal hazard was investigated by comparing it with iron picrate obtained by the chemical synthesis method (FePic(Ba)). FePic has eight or more water molecules of crystallization and consists of a mixture of various hydrates. It shows low sensitivity to friction and drop hammer tests due to the large number of water molecules of crystallization. Under the experimental conditions of the thermal analysis, the hydrated iron picrates began to decompose before being dehydrated to form the anhydrous salt. Prolonged holding under natural environmental conditions does not appear to result in formation of the dangerous anhydrous salt. Based on the observed heating rate dependence, it is thought that the hydrated iron picrate should start to decompose before dehydration to the anhydrous salt occurs when subjected to a large heating rate. PMID:16343750

  4. 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.

  5. Iron acquisition by Ornithobacterium rhinotracheale.

    PubMed

    Tabatabai, Louisa B; Zehr, Emilie S; Zimmerli, Mandy K; Nagaraja, Kakambi V

    2008-09-01

    Ornithobacterium rhinotracheale (ORT) is an emerging respiratory pathogen of poultry in North America that is causing millions of dollars in economic losses to the poultry industry. Ornithobacterium rhinotracheale is associated with airsacculitis, pleuritis, pneumonia, and consolidation of lungs. Little is known about the molecular mechanisms of infection. In this study, the mechanism of iron acquisition by O. rhinotracheale was explored. O. rhinotracheale strains grown under iron deprivation in media containing 200 microM 2,2'-dipyridyl did not secrete siderophores as measured by the chrome azurol S (CAS) agar and CAS solution assays. Filter disks impregnated with various protein-bound iron compounds and inorganic iron salts of Fe(III) and Fe(II) placed on iron-restricted agar inoculated with a lawn of O. rhinotracheale supported growth from sheep and porcine hemoglobins, ovotransferrin, Fe(III), and Fe(II), but they did not support growth from bovine transferrin, bovine apo-transferrin, bovine lactoferrin, and hemin. However, both bovine hemoglobin and transferrin supported growth of O. rhinotracheale serotype C. Four immunoreactive proteins involved in iron acquisition were identified in an O. rhinotracheale membrane extract by using mass spectrometry. Furthermore, O. rhinotracheale field strains showed differential sensitivity to 2,2'-dipyridyl. Of the 72 field strains tested, 22 strains were resistant to the iron chelator at concentrations of 50 microM and 100 microM, suggesting this attribute may be related to disease-producing potential of these strains. This is the first report on the identification of the iron acquisition mechanism of O. rhinotracheale. PMID:18939629

  6. Luminescent iron clusters in solution

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  7. Iron overload and toxicity: implications for anesthesiologists.

    PubMed

    Shander, Aryeh; Berth, Ulrike; Betta, Joanne; Javidroozi, Mazyar

    2012-08-01

    Conditions leading to iron overload range from rare hereditary disorders to more common medical conditions associated with chronic blood transfusions. Iron overload has deleterious effects on various vital organs (eg, liver, heart, and endocrine glands). Serum ferritin (in conjunction with transferrin saturation) is the most widely used test to evaluate iron burden and to screen for iron overload. The management plan should be adjusted to account for iron overload and potential consequences of liver, heart, and other organ involvement. PMID:22658368

  8. 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.

  9. 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.

  10. 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.

  11. The characterization of iron surfaces

    NASA Astrophysics Data System (ADS)

    Kock, A. J. H. M.; Geus, J. W.

    The extensive literature data on the adsorptive properties and reactivity of iron single crystal surfaces, films, and supported catalysts is reviewed. The intent of this paper is (i) to narrow the present gap between the surface chemistry discipline and catalysis research, and (ii) to gain a detailed insight into common catalyst characterization procedures. The interaction of oxygen, hydrogen, carbon monoxide, and nitrogen with the single crystal surfaces (110), (100), and (111) as well as with film specimens is dealt with. In addition to the adsorptive properties of well-defined iron oxide specimens also the reactivity of oxidized single crystal substrates towards hydrogenation is treated. Comprehension of both the adsorptive properties and the reactivity of metallic as well as of oxidized iron surfaces is required to understand what molecular phenomena proceed during a chemisorption experiment on a catalyst sample. Volumetric gas adsorption, temperature-programmed desorption, Mssbauer spectroscopy, and infrared spectroscopy experiments are discussed in relation to the above fundamental studies. The unfathomed discrepancy between the hydrogen adsorption features of single crystals and high-disperse supported iron catalysts can be appreciated from surface science constituents. The presence of oxygen at the metal-UHV interface of small metallic iron particles is made plausible. An alternative explanation for the magnetic anisotropy of magnesia- and silica-supported iron particles is advanced (exchange anisotropy).

  12. Ferritins: furnishing proteins with iron.

    PubMed

    Bradley, Justin M; Le Brun, Nick E; Moore, Geoffrey R

    2016-03-01

    Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-?-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe(2+) oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores, consider how iron might be released from ferritins, and examine in detail how three selected ferritins oxidise Fe(2+) to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins. PMID:26825805

  13. The World Beyond Iron

    NASA Astrophysics Data System (ADS)

    Kalvius, G. Michael

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

  14. Superconductivity in iron compounds

    NASA Astrophysics Data System (ADS)

    Stewart, G. R.

    2011-10-01

    Kamihara and coworkers’ report of superconductivity at Tc=26K in fluorine-doped LaFeAsO inspired a worldwide effort to understand the nature of the superconductivity in this new class of compounds. These iron pnictide and chalcogenide (FePn/Ch) superconductors have Fe electrons at the Fermi surface, plus an unusual Fermiology that can change rapidly with doping, which lead to normal and superconducting state properties very different from those in standard electron-phonon coupled “conventional” superconductors. Clearly, superconductivity and magnetism or magnetic fluctuations are intimately related in the FePn/Ch, and even coexist in some. Open questions, including the superconducting nodal structure in a number of compounds, abound and are often dependent on improved sample quality for their solution. With Tc values up to 56 K, the six distinct Fe-containing superconducting structures exhibit complex but often comparable behaviors. The search for correlations and explanations in this fascinating field of research would benefit from an organization of the large, seemingly disparate data set. This review provides an overview, using numerous references, with a focus on the materials and their superconductivity.

  15. Iron, oxidative stress and gestational diabetes.

    PubMed

    Zhuang, Taifeng; Han, Huijun; Yang, Zhenyu

    2014-09-01

    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

  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. Rethinking Iron Regulation and Assessment in Iron Deficiency, Anemia of Chronic Disease, and Obesity: Introducing Hepcidin

    PubMed Central

    Tussing-Humphreys, Lisa; Pustacioglu, Cenk; Nemeth, Elizabeta; Braunschweig, Carol

    2012-01-01

    Adequate iron availability is essential to human development and overall health. Iron is a key component of oxygen-carrying proteins, has a pivotal role in cellular metabolism, and is essential to cell growth and differentiation. Inadequate dietary iron intake, chronic and acute inflammatory conditions, and obesity are each associated with alterations in iron homeostasis. Tight regulation of iron is necessary because iron is highly toxic and human beings can only excrete small amounts through sweat, skin and enterocyte sloughing, and fecal and menstrual blood loss. Hepcidin, a small peptide hormone produced mainly by the liver, acts as the key regulator of systemic iron homeostasis. Hepcidin controls movement of iron into plasma by regulating the activity of the sole known iron exporter ferroportin-1. Downregulation of the ferroportin-1 exporter results in sequestration of iron within intestinal enterocytes, hepatocytes, and iron-storing macrophages reducing iron bioavailability. Hepcidin expression is increased by higher body iron levels and inflammation and decreased by anemia and hypoxia. Importantly, existing data illustrate that hepcidin may play a significant role in the development of several iron-related disorders, including the anemia of chronic disease and the iron dysregulation observed in obesity. Therefore, the purpose of this article is to discuss iron regulation, with specific emphasis on systemic regulation by hepcidin, and examine the role of hepcidin within several disease states, including iron deficiency, anemia of chronic disease, and obesity. The relationship between obesity and iron depletion and the clinical assessment of iron status will also be reviewed. PMID:22717199

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

    PubMed Central

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

    2014-01-01

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

  20. 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

  1. Essential metals--case study on iron.

    PubMed

    Gurzau, Eugen S; Neagu, Corneliu; Gurzau, Anca Elena

    2003-09-01

    Iron is a vital element in life. Because of the insolubility of iron oxides and sulfides the implication is that dissolved iron was fairly abundant and that oxygen and sulfide were rare in the atmosphere and ocean. Iron and its compounds present as pollutants in the atmosphere can cause deleterious effects to humans, animals, and materials. Analyses of urban air samples show that the iron content averages 1.6 microg/m(3), with the iron and steel industry probably the most likely source of emission. Iron is a natural component of soils and its concentration can be influenced by some industries. Iron concentration in surface water varies greatly, from 61 ppm to 2680 ppm. The disposition of iron in the human body is regulated by a complex mechanism to maintain homeostasis. Iron concentrations in body tissues must be tightly regulated because excessive iron leads to tissue damage, as a result of formation of free radicals. Iron has the capacity to accept and donate electrons readily. The content of body iron is regulated primarily by absorption since humans have no physiological mechanism by which excess iron is excreted. Iron has been identified as a component of asbestos and other mineral and synthetic fibers. Inhalation of iron oxide fumes or dust by workers in the metal industries may result in deposition of iron particles in lungs, producing an X-ray appearance resembling silicosis. During the last decades efforts regarding dietary iron supply focused mostly on the prevention of deficiencies, especially during growth and pregnancy. The chemical form of the iron influences absorption, as do interrelationships with other dietary components. PMID:12915152

  2. "There is iron and iron" Burkinab women's perceptions of iron supplementation: a qualitative study.

    PubMed

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

    2014-10-01

    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. 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. Anemia, for which no Moor 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. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    SciTech Connect

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

    1985-09-01

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

  7. When Less is More: Novel Mechanisms of Iron Conservation

    PubMed Central

    Bayeva, Marina; Chang, Hsiang-Chun; Wu, Rongxue; Ardehali, Hossein

    2016-01-01

    Disorders of iron homeostasis are very common, yet the molecular mechanisms of iron regulation remain understudied. Over 20 years have passed since the first characterization of iron regulatory proteins (IRP) as mediators of cellular iron deficiency response in mammals through iron acquisition. However, little is known about other mechanisms necessary for adaptation to low-iron states. In this review we present recent evidence that establishes existence of a new iron regulatory pathway aimed at iron conservation and optimization of iron use through suppression of non-essential iron-consuming processes. Moreover, we discuss the possible links between iron homeostasis and energy metabolism uncovered by studies of iron deficiency response. PMID:23948590

  8. [Iron, hepcidin and chronic kidney disease].

    PubMed

    Fievet, Patrick; Brazier, Franois

    2011-04-01

    Iron deficiency is commonly observed in chronic kidney disease. Blood loss and iron consumption under erythropiesis activating agents (ESA) induce absolute deficiency whereas defect of iron intestinal absorption and storage release account for functional deficiency. High hepcidin plasma levels are probably induced by inflammatory process and can explain functional deficiency. However, hepcidin is negatively correlated with ESA needs and hepcidin expression is influenced by other factors as degree of renal insufficiency, iron pool, treatments (iron IV and ESA). IV iron is the common therapeutic approach of iron deficiency and only normalized iron marrow supply cannot account for his efficiency. New IV iron products allow us to conceive new therapeutic schemes. Hepcidin inhibition is another therapeutic alternative. PMID:21186144

  9. Hepcidin: regulation of the master iron regulator

    PubMed Central

    Rishi, Gautam; Wallace, DanielF.; 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

  10. Iron trafficking system in Helicobacter pylori.

    PubMed

    Ge, Ruiguang; Sun, Xuesong

    2012-04-01

    Helicobacter pylori infections are closely associated with peptic ulcers, gastric malignancy and iron deficiency anemia. Iron is essential for almost all living organisms and the investigation of iron uptake and trafficking system is thus important to understand the pathological roles of H. pylori. Up to now, the iron trafficking system of H. pylori is not yet fully clear and merits further efforts in this regards. The available information about iron uptake and regulation has been discussed in this concise review, such as FeoB in ferrous transportation, FrpB2 in hemoglobin uptake, HugZ in heme processing, virulence factors (VacA and CagA) in transferrin utilization, Pfr and NapA in iron storage and Fur in iron regulation. The identified iron trafficking system will help us to understand the pathological roles of H. pylori in the various gastric diseases and iron deficiency anemia and stimulates further development of effective anti-bacterial drugs. PMID:22127376

  11. Shigella Iron Acquisition Systems and their Regulation

    PubMed Central

    Wei, Yahan; Murphy, Erin R.

    2016-01-01

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

  12. 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

  13. Iron for proliferation of cell lines and hematopoietic progenitors: Nailing down the intracellular functional iron concentration.

    PubMed

    Pourcelot, Emmanuel; Lnon, Marine; Mobilia, Nicolas; Cahn, Jean-Yves; Arnaud, Josiane; Fanchon, Eric; Moulis, Jean-Marc; Mossuz, Pascal

    2015-07-01

    Iron is an essential nutrient which must be provided in sufficient amounts to support growth of eukaryotic cells. All organisms devote specialized pathways to ensure proper delivery. Yet, a quantitative assessment of the intra-cellular iron concentration needed to allow the cell cycle to proceed in mammalian cells is missing. Starting from iron-depleted cell lines or primary hematopoietic progenitors prepared with clinically implemented iron chelators, replenishment via transferrin and other iron sources has been quantitatively monitored through the main endogenous markers of the cellular iron status, namely proteins involved in the uptake (transferrin receptor), the storage (ferritin), and the sensing (Iron Regulatory Proteins) of iron. When correlated with measurements of iron concentrations and indicators of growth, this minimally intrusive approach provided an unprecedented estimate of the intracellular iron concentration acting upon iron-centered regulatory pathways. The data were analyzed with the help of a previously developed theoretical treatment of cellular iron regulation. The minimal cellular iron concentration required for cell division was named functional iron concentration (FIC) to distinguish it from previous estimates of the cellular labile iron. The FIC falls in the low nanomolar range for all studied cells, including hematopoietic progenitors. These data shed new light on basic aspects of cellular iron homeostasis by demonstrating that sensing and regulation of iron occur well below the concentrations requiring storage or becoming noxious in pathological conditions. The quantitative assessment provided here is relevant for monitoring treatments of conditions in which iron provision must be controlled to avoid unwanted cellular proliferation. PMID:25827953

  14. Retinal iron homeostasis in health and disease.

    PubMed

    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

  15. [Iron metabolism: State of the art].

    PubMed

    Beaumont, C; Karim, Z

    2013-01-01

    About 60% of body iron is associated with hemoglobin in circulating red blood cells and daily erythropoiesis requires about 25 to 30mg iron per day. This iron is provided by macrophages through recycling of heme iron following phagocytosis of senescent red blood cells and heme catabolism. Intestinal iron absorption (1 to 2mg per day) only compensates for daily iron losses. Hepcidin, a 25amino-acid peptide synthesized in hepatocytes, secreted in plasma and rapidly removed in urines, is a negative regulator of both intestinal iron absorption and heme iron recycling by macrophages. Hepcidin synthesis is stimulated by iron or by inflammation (mostly by IL-6) and is repressed by iron deficiency and by all conditions that stimulate bone marrow erythropoiesis such as anemia, bleeding, hemolysis, dyserythropoiesis or erythropoietin injections. A defect in the activation of hepcidin normally triggered by iron excess is the underlying mechanism for all juvenile or adult forms of hemochromatosis whereas a defect in hepcidin repression is responsible for an iron deficiency iron refractory anemia (IRIDA). Reduced hepcidin filtration in renal insufficiency contributes to the associated anemia and stimulation of hepcidin synthesis by inflammation is a major determinant of the anemia of chronic disorders. New therapeutic perspectives are currently underway such as the development of agonists or antagonists of hepcidin or siRNA approaches aiming at reducing hepcidin synthesis. The validation of hepcidin assays in a near future will allow identifying the patients most likely to benefit from intravenous iron therapy. PMID:22595534

  16. Integrated Neighborhood and Integrated Education

    ERIC Educational Resources Information Center

    Milgram, Jean Gregg

    1974-01-01

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

  17. Accelerated dissolution of iron oxides in ice

    NASA Astrophysics Data System (ADS)

    Jeong, D.; Kim, K.; Choi, W.

    2012-08-01

    Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a~new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4), the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the type of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid-like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from -10 C to -196 C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

  18. Accelerated dissolution of iron oxides in ice

    NASA Astrophysics Data System (ADS)

    Jeong, D.; Kim, K.; Choi, W.

    2012-11-01

    Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4), the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the surface area of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from -10 to -196 C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

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

    PubMed Central

    Carmona, Merc; Ayt, Jos; Hidalgo, Elena

    2015-01-01

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

  20. Preparation and protection of iron and iron compounds

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  1. 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.

  2. 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.

  3. Southern Ocean natural iron fertilization

    NASA Astrophysics Data System (ADS)

    Charette, Matt; Sanders, Richard; Zhou, Meng

    2011-08-01

    Modeling and Synthesis of Southern Ocean Natural Iron Fertilization; Woods Hole, Massachusetts, 27-29 June 2011; For many years a major paradox in ocean science was the existence of regions where the major nutrients are present in nonlimiting concentrations yet phytoplankton biomass is low. Pioneering experiments in the 1990s firmly established that the likely cause of this high-nutrient, low-chlorophyll condition is a deficit of iron relative to other nutrients. Iron is required for numerous processes within the cell, including photosynthesis, respiration, and nutrient uptake, yet because of its chemical properties, in seawater it is present at vanishingly small concentration levels. Elucidating the role of iron in governing ecosystem functioning and carbon sequestration is in its infancy; however, one promising approach is to make observations in regions where landmasses act as point sources of iron. In 2004-2006, three separate expeditions targeted the southern Indian Ocean around the Crozet and Kerguelen Islands and in the southern Scotia Sea around the southern Drake Passage. Representatives from all three programs met recently to compare findings and identify critical gaps in existing knowledge.

  4. Iron in Parkinson's Disease Revisited

    NASA Astrophysics Data System (ADS)

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

    2002-06-01

    Mssbauer 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. Mssbauer 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 Mssbauer 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 Mssbauer parameters different from ferritin. We found a slightly higher asymmetry and intensity of the 4.1 K doublet in Mssbauer 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.

  5. Melting Behavior of Iron Alloys

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Lee, K. K. M.

    2014-12-01

    Earth's core consists of an iron-nickel alloy with approximately ten percent of other light elements (e.g., C, S, Si, O). Therefore, the behavior of iron alloys of similar composition at the temperatures and pressures that resemble the conditions of Earth's core is of fundamental importance to our understanding of the inner workings of our planet. The melting behavior of iron alloys is especially important as it sheds light on the conditions at the boundary between Earth's solid inner core and its liquid outer core, as well as puts constraints on the age of the inner core. Here, we report the melting curve of iron alloys based on laser-heated diamond anvil cell experiments. Four-color multi-wavelength imaging radiometry is used to determine the temperature profiles of the heated spot during melting and electron microscopy is used to map the compositional and textural changes of the iron alloys. An automated analysis of the texture, composition and temperature of the hot spots is conducted with an in-house developed image processing script, which identifies the melting point of the alloys and the preferred host phases of minor elements (e.g., Ni, Cr, Mn) at high-pressure/temperature conditions.

  6. ?-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

  7. Fluorescent bacteria for colloidal iron biosensors

    NASA Astrophysics Data System (ADS)

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

    2006-01-01

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

  8. 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

  9. Advances in Pediatric Intravenous Iron Therapy.

    PubMed

    Mantadakis, Elpis

    2016-01-01

    Iron deficiency anemia (IDA) continues to be very common worldwide. Intravenous (IV) iron is an infrequently used therapeutic option in children with IDA despite numerous studies in adults and several small but notable pediatric studies showing efficacy and safety. Presently, the availability of newer IV iron products allows for replacement of the total iron deficit at a single setting. These products appear safer compared to the high molecular weight iron dextrans of the past. Herein, we review the medical literature and suggest that front line use of IV iron should be strongly considered in diseases associated with IDA in children. Pediatr Blood Cancer 2015 Wiley Periodicals, Inc. PMID:26376214

  10. The Role of Hepcidin in Iron Metabolism

    PubMed Central

    Nemeth, Elizabeta; Ganz, Tomas

    2009-01-01

    Hepcidin is the central regulator of systemic iron homeostasis. Dysregulation of hepcidin production results in a variety of iron disorders. Hepcidin deficiency is the cause of iron overload in hereditary hemochromatosis, iron-loading anemias, and hepatitis C. Hepcidin excess is associated with anemia of inflammation, chronic kidney disease and iron-refractory iron deficiency anemia. Diagnostic and therapeutic applications of this new knowledge are beginning to emerge. Dr. Ernest Beutler played a significant role in advancing our understanding of the function of hepcidin. This review is dedicated to his memory. PMID:19907144

  11. 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

  12. 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)

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

    PubMed Central

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

    2002-01-01

    Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (?5 ?g/day) and iron-normal (800 ?g/day) rats and in both groups after daily high-iron supplementation (8,000 ?g/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 ?g) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake. PMID:11854522

  14. 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.

  15. [Iron supplementation is recommended in renal anemia].

    PubMed

    Stefansson, Bergur

    2015-01-01

    The main causes for renal anemia are insufficient erythropoietin production and absolute and/or functional iron deficiency. Absolute iron deficiency occurs with blood losses (most common are gastro-intestinal bleedings and hemodialysis treatments) or inadequate iron absorption in the gut (mainly due to increased circulating hepcidin or treatment with erythropoiesis stimulating agents). The explanation for functional iron deficiency is the high level of circulating hepcidin found in chronic kidney disease patients. The transmembrane iron transporter ferroportin is internalized and degraded by hepcidin with subsequent decreased iron absorption from the gut and reduced mobilization from iron storing cells. Thus, the bioavailability of iron is decreased despite normal or high total iron content. The diagnosis of iron deficiency in chronic kidney disease can be problematic because inflammation is common, leading to false high circulating ferritin and false low transferrin saturation. Treatment with iron is recommended in chronic kidney disease patients to prevent or minimize anemia symptoms or to reduce the need for treatment with erythropoiesis stimulating agents or blood transfusions. Intravenous iron is recommended in patients on dialysis treatment but in non-dialysis patients, a 1-3 month trial of oral iron can be tried. However, this is seldom sufficient in patients treated with erythropoiesis stimulating agents. PMID:25756713

  16. Direct Reduction of Iron Ore

    NASA Astrophysics Data System (ADS)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  17. Magnetism in dense hexagonal iron

    PubMed Central

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

    2004-01-01

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

  18. [Iron overload and insulin resistance].

    PubMed

    Vantyghem, M-C; Girardot, C; Boulogne, A; Wemeau, J-L

    2005-11-01

    There is increasing evidence that moderately elevated body iron stores, below levels commonly found in genetic hemochromatosis, may be associated with adverse health outcomes. Genetic hemochromatosis, characterized by transferrin saturation (TS) greater than 45%, is most often linked to homozygosity of the HFE C282Y allele. The phenotype is also modulated by mutations of more recently discovered genes (including ferroportin, hemojuvelin, hepcidin, and transferrin receptor) and environmental factors (including alcohol, viruses, diet, blood loss). Iron overload without hemochromatosis is characterized by high levels of serum ferritin and normal TS, as seen in dysmetabolic hepatosiderosis. Elevated serum ferritin levels predict incident type 2 diabetes in prospective studies and have been associated with hypertension, dyslipidemia, glucose tolerance disturbances, central adiposity, and metabolic syndrome. High ferritin levels are not synonymous with iron overload and may in some cases be a simple marker of insulin resistance. PMID:16292193

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

    PubMed

    Sayed, Farheen N; Polshettiwar, Vivek

    2015-01-01

    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. 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

  1. Iron chelation and multiple sclerosis

    PubMed Central

    Weigel, KelseyJ.; Lynch, SharonG.; LeVine, StevenM.

    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., 68h 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 bloodbrain 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

  2. Disassembling iron availability to phytoplankton.

    PubMed

    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 CO(2) drawdown in vast ocean regions. Yet a clear-cut definition of bioavailability remains elusive, with elements of iron speciation and kinetics, phytoplankton physiology, light, temperature, and microbial interactions, to name a few, all intricately intertwined into this concept. Here, in a synthesis of published and new data, we attempt to disassemble the complex concept of iron bioavailability to phytoplankton by individually exploring some of its facets. We distinguish between the fundamentals of bioavailability - the acquisition of Fe-substrate by phytoplankton - and added levels of complexity involving interactions among organisms, iron, and ecosystem processes. We first examine how phytoplankton acquire free and organically bound iron, drawing attention to the pervasiveness of the reductive uptake pathway in both prokaryotic and eukaryotic autotrophs. Turning to acquisition rates, we propose to view the availability of various Fe-substrates to phytoplankton as a spectrum rather than an absolute "all or nothing." We then demonstrate the use of uptake rate constants to make comparisons across different studies, organisms, Fe-compounds, and environments, and for gaging the contribution of various Fe-substrates to phytoplankton growth in situ. Last, we describe the influence of aquatic microorganisms on iron chemistry and fate by way of organic complexation and bio-mediated redox transformations and examine the bioavailability of these bio-modified Fe species. PMID:22529839

  3. 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

  4. Iron chelation and multiple sclerosis.

    PubMed

    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., 6-8h 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

  5. Selected properties of iron aluminides

    SciTech Connect

    Schneibel, J.H.

    1994-09-01

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

  6. 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

  7. 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.

  8. Integrating Art.

    ERIC Educational Resources Information Center

    BCATA Journal for Art Teachers, 1991

    1991-01-01

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

  9. Iron-oxo complexes: Elusive iron(V) species identified

    NASA Astrophysics Data System (ADS)

    McDonald, Aidan R.; Que, Lawrence

    2011-10-01

    A (hydroxo)oxoiron(V) oxidant has been implicated in cis-dihydroxylation reactions catalysed by Rieske dioxygenases and biomimetic non-haem iron complexes, but with only indirect proof of its existence. Variable-temperature mass spectrometry now provides persuasive evidence for just such a reactive intermediate in a synthetic system.

  10. Soft tissue calcification induced by iron complexes.

    PubMed

    Anghileri, L J

    1992-07-01

    Complexed iron (III) induces a local calcification of soft tissues in mice that is strongly dependent upon the nature of the complexing molecule. Ferric lactate is much more effective in inducing calcification than iron dextran. PMID:1393784

  11. 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 ...

  12. 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 ...

  13. 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 ...

  14. Iron, hepcidin, and the metal connection

    PubMed Central

    Loréal, Olivier; Cavey, Thibault; Bardou-Jacquet, Edouard; Guggenbuhl, Pascal; Ropert, Martine; Brissot, Pierre

    2014-01-01

    Identification of new players in iron metabolism, such as hepcidin, which regulates ferroportin and divalent metal transporter 1 expression, has improved our knowledge of iron metabolism and iron-related diseases. However, from both experimental data and clinical findings, “iron-related proteins” appear to also be involved in the metabolism of other metals, especially divalent cations. Reports have demonstrated that some metals may affect, directly or indirectly, the expression of proteins involved in iron metabolism. Throughout their lives, individuals are exposed to various metals during personal and/or occupational activities. Therefore, better knowledge of the connections between iron and other metals could improve our understanding of iron-related diseases, especially the variability in phenotypic expression, as well as a variety of diseases in which iron metabolism is secondarily affected. Controlling the metabolism of other metals could represent a promising innovative therapeutic approach. PMID:24926268

  15. 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 ...

  16. Magnetic domains in cobalt and iron borides

    NASA Astrophysics Data System (ADS)

    Livingston, L. D.

    1981-03-01

    Using Kerr and Bitter techniques, magnetic domain patterns have been studied in various cobalt, iron, and cobalt-iron borides prepared by chill casting, directional solidification, and melt-spinning. Magnetic symmetries and metallurgical stability of the phases are discussed.

  17. Mechanisms of iron metabolism in Caenorhabditis elegans

    PubMed Central

    Anderson, Cole P.; Leibold, Elizabeth A.

    2014-01-01

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

  18. 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.

  19. 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

  20. 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

  1. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. 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)

  4. 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 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain Materials § 148.275 Iron oxide, spent; iron sponge, spent....

  5. 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

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

    PubMed Central

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

    2015-01-01

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

  7. 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.

  8. 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

  9. Thermal fracture endurance of cast irons with application study of pig iron ingot molds

    NASA Astrophysics Data System (ADS)

    Lee, Jye-Long; Lee, Shen-Chih

    1995-06-01

    Pig iron ingot molds manufactured with flake, compacted graphite cast iron, and spheroidal graphite cast iron were installed on a pig iron casting machine and subjected to thermal cycling for studying thermal fracture endurance of the three cast irons. The effects of graphite morphology on the fracture mechanism were analyzed by examining the fracture patterns, microstructures, and microcracks in the failed molds. The determining factors of thermal fracture endurance were elucidated with thermal fracture resistance indices. Compacted graphite cast iron exhibited better thermal fracture endurance than flake and spheroidal graphite cast irons because of its higher strength-to-thermal stress ratio.

  10. Bioavailability of iron in multiple fortified milk.

    PubMed

    Sachdeva, Bhawana; Kaushik, Ravinder; Arora, Sumit; Kapila, Suman

    2015-09-01

    The objectives of the study were to evaluate the bioavailability of iron in milk fortified with ferric pyrophosphate (FPP) soluble and vitamin A acetate and to establish the role of vitamin A in enhancement of iron absorption. Balance indices viz. apparent digestibility coefficient, % retention/intake of iron and haematological parameters viz. blood haemoglobin, plasma ferritin, plasma transferrin and iron content in rat livers were analyzed to evaluate iron bioavailability. Anaemia was induced in one group of rats to evaluate the effect of iron status of body on iron absorption from diet. The results of in vivo study showed that feeding of rats with lyophilates of milk fortified with FPP soluble and FPP soluble + vitamin A acetate had a significant effect on the balance indices of the iron as well as on the haematological parameters and iron liver status. The utilization of iron in the body, as indicated by the results of balance indices, haematological parameters and iron status of livers was significantly higher in anaemic rats compared to control group rats. Vitamin A appeared to be playing role in enhancement of iron absorption and utilization in body. PMID:26345022

  11. 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

  12. Voice Modulations in German Ironic Speech

    ERIC Educational Resources Information Center

    Scharrer, Lisa; Christmann, Ursula; Knoll, Monja

    2011-01-01

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

  13. 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…

  14. Iron status in athletes. An update.

    PubMed

    Newhouse, I J; Clement, D B

    1988-06-01

    As more studies are done on the iron status of athletes, the significance of apparent iron deficiency remains controversial. Do observed changes in iron status in athletes indicate an actual iron deficiency or a physiological response to exercise? Iron replacement would clearly be indicated if an iron deficiency was present but would not be necessary or effective if the observed changes were simply a physiological response. There is agreement that serum ferritin and haemoglobin decrease with some exercise conditions and that some indicators of haemolysis, such as serum haptoglobin and bilirubin, change in response to exercise. Expansion of plasma volume and the shift of iron storage from bone marrow to the liver could support the claim that the apparent reduced iron status parameters occurring with exercise are misleading. Countering this concept are studies in athletes which demonstrate dietary iron intake deficiencies and blood loss in the gastrointestinal and urinary tract. Iron deficiency is common in the general population, particularly in women. Therefore, continued monitoring of iron status in athletes appears justified in the face of present knowledge. Replacement therapy, when iron deficiency is apparent, is recommended. PMID:3041528

  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. Voice Modulations in German Ironic Speech

    ERIC Educational Resources Information Center

    Scharrer, Lisa; Christmann, Ursula; Knoll, Monja

    2011-01-01

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

  17. Micromilling enhances iron bioaccessibility from wholegrain wheat.

    PubMed

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

    2014-11-19

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

  18. 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.

  19. 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

  20. 21 CFR 522.1182 - Iron injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and conditions of use. It is used in baby pigs by sponsors in § 510.600(c) of this chapter as follows... baby pig anemia due to iron deficiency, intramuscularly inject 200 mg of elemental iron (1 mL) at 1 to 3 days of age. (ii) For treatment of baby pig anemia due to iron deficiency, intramuscularly...

  1. 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

  2. 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...

  3. Fate of blood meal iron in mosquitos

    PubMed Central

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

    2007-01-01

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

  4. Iron bioaccumulation in mycelium of Pleurotus ostreatus.

    PubMed

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

    2015-03-01

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

  5. Treatment of Iron Deficiency in Women

    PubMed Central

    Breymann, C.; Rmer, 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

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  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. How Is Iron-Deficiency Anemia Treated?

    MedlinePLUS

    ... come in pill form or in drops for children. Large amounts of iron can be harmful, so take iron supplements only as your doctor prescribes. Keep iron supplements out of reach from children. This will prevent them from taking an overdose ...

  12. Africa: The Birthplace of Iron Mining.

    ERIC Educational Resources Information Center

    Mutunhu, Tendai

    1981-01-01

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

  13. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  14. Iron Deficiency in Autism and Asperger Syndrome.

    ERIC Educational Resources Information Center

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

    2002-01-01

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

  15. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No. 1332-37-2), Color Index No. 77491, shall conform...

  16. 49 CFR 230.91 - Chafing irons.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  17. 21 CFR 73.3125 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Iron oxides. 73.3125 Section 73.3125 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No. 1332-37-2), Color Index No. 77491, shall conform...

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

    PubMed

    Martelli, Alain; Schmucker, Stphane; Reutenauer, Laurence; Mathieu, Jacques R R; Peyssonnaux, Carole; Karim, Zoubida; Puy, Herv; Galy, Bruno; Hentze, Matthias W; Puccio, Hlne

    2015-02-01

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

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

    NASA Astrophysics Data System (ADS)

    Jiang, Jiachen; Bambi, Cosimo; Steiner, James F.

    2015-05-01

    The iron K? 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 105 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.

  20. 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

  1. Iron Deficiency and Bariatric Surgery

    PubMed Central

    Jáuregui-Lobera, Ignacio

    2013-01-01

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

  2. Iron uptake by Escherichia coli.

    PubMed

    Braun, Volkmar

    2003-09-01

    Ferric iron is transported into Escherichia coli by a number of chelating compounds. Iron transport through the outer membrane by citrate, ferrichrome, enterobactin, aerobactin, yersiniabactin, and heme is catalyzed by highly specific proteins and across the cytoplasmic membrane by ABC transport systems with lower specificity. Transport across the outer membrane requires energy, which is provided by the proton motive force of the cytoplasmic membrane and transmitted to the outer membrane via the TonB-ExbB-ExbD proteins. Binding of substrates induces large long-range structural changes in the transport proteins, but does not open the channel. It is thought that the channel is opened by energy input from the cytoplasmic membrane. Although a basic understanding of how the transport proteins might function has been obtained from the crystal structures of three outer membrane proteins of E. coli and from many genetic and biochemical experiments, numerous fundamental questions still remain open. Transcription of the transport protein genes is regulated by the Fur protein, which when loaded with ferrous iron functions as a repressor. Fur also positively regulates genes of iron-containing proteins by repressing synthesis of an anti-sense RNA. Regulation of ferric citrate transport genes via a transmembrane device has become the paradigm of the regulation of a variety of systems, including the hypersensitivity response of plants to bacterial infections. PMID:12957834

  3. 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,...

  4. 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

  5. Corrosion of ductile iron piping

    SciTech Connect

    Szeliga, M.

    1995-12-31

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

  6. 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.

  7. Iron oxides in human spleen.

    PubMed

    Kopni, Martin; Miglierini, Marcel; Lan?ok, Adriana; Dekan, Jlius; ?aplovicov, Mria; Jakubovsk, Jn; 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), Mssbauer 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

  8. Dynamic transition in supercritical iron

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  9. 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.

  10. FUGITIVE EMISSIONS FROM IRON FOUNDRIES

    EPA Science Inventory

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

  11. 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 120C to 175C 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 (?154C), 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

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

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2013-12-01

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

  14. 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

  15. 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 ...

  16. 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

  17. 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.

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

    PubMed Central

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

    2013-01-01

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

  19. 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 575C, 600C, 625C and 650C, 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.

  20. Iron and steel industry process model

    SciTech Connect

    Sparrow, F.T.; Pilati, D.; Dougherty, T.; McBreen, E.; Juang, L.L.

    1980-01-01

    The iron and steel industry process model depicts expected energy-consumption characteristics of the iron and steel industry and ancillary industries for the next 25 years by means of a process model of the major steps in steelmaking, from ore mining and scrap recycling to the final finishing of carbon, alloy, and stainless steel into steel products such as structural steel, slabs, plates, tubes, and bars. Two plant types are modeled: fully integrated mills and mini-mills. User-determined inputs into the model are as follows: projected energy and materials prices; projected costs of capacity expansion and replacement; energy-conserving options, both operating modes and investments; the internal rate of return required on investment; and projected demand for finished steel. Nominal input choices in the model for the inputs listed above are as follows: National Academy of Sciences Committee on Nuclear and Alternative Energy Systems Demand Panel nominal energy-price projections for oil, gas, distillates, residuals, and electricity and 1975 actual prices for materials; actual 1975 costs; new technologies added; 15% after taxes; and 1975 actual demand with 1.5%/y growth. The model reproduces the base-year (1975) actual performance of the industry; then, given the above nominal input choices, it projects modes of operation and capacity expansion that minimize the cost of meeting the given final demands for each of 5 years, each year being the midpoint of a 5-year interval. The output of the model includes the following: total energy use and intensity (Btu/ton) by type, by process, and by time period; energy conservation options chosen; utilization rates for existing capacity; capital-investment decisions for capacity expansion.

  1. Metabolic Remodeling in Iron-deficient Fungi

    PubMed Central

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

    2012-01-01

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

  2. 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 (α-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.

  3. 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.

  4. 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 (26C and 37C). 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 (26C and 37C), there was little evidence for temperature-specific adaptation processes to iron starvation. PMID:20113483

  5. On risks and benefits of iron supplementation recommendations for iron intake revisited.

    PubMed

    Schmann, Klaus; Ettle, Thomas; Szegner, Bernadett; Elsenhans, Bernd; Solomons, Noel W

    2007-01-01

    Iron is an essential trace element with a high prevalence of deficiency in infants and in women of reproductive age from developing countries. Iron deficiency is frequently associated with anaemia and, thus, with reduced working capacity and impaired intellectual development. Moreover, the risk for premature delivery, stillbirth and impaired host-defence is increased in iron deficiency. Iron-absorption and -distribution are homeostatically regulated to reduce the risk for deficiency and overload. These mechanisms interact, in part, with the mechanisms of oxidative stress and inflammation and with iron availability to pathogens. In the plasma, fractions of iron may not be bound to transferrin and are hypothesised to participate in atherogenesis. Repleted iron stores and preceding high iron intakes reduce intestinal iron absorption which, however, offers no reliable protection against oral iron overload. Recommendations for dietary iron intake at different life stages are given by the US Food and Nutrition Board (FNB), by FAO/WHO and by the EU Scientific Committee, among others. They are based, on estimates for iron-losses, iron-bioavailability from the diet, and iron-requirements for metabolism and growth. Differences in choice and interpretation of these estimates lead to different recommendations by the different panels which are discussed in detail. Assessment of iron-related risks is based on reports of adverse health effects which were used in the attempts to derive an upper safe level for dietary iron intake. Iron-related harm can be due to direct intestinal damage, to oxidative stress, or to stimulated growth of pathogens. Unfortunately, it is problematic to derive a reproducible cause-effect and dose-response relationship for adverse health effects that suggest a relationship to iron-intake, be they based on mechanistic or epidemiological observations. Corresponding data and interpretations are discussed for the intestinal lumen, the vascular system and for the intracellular and interstitial space, considering interference of the mechanisms of iron homoeostasis as a likely explanation for differences in epidemiological observations. PMID:17697954

  6. In vitro iron availability from iron-fortified whole-grain wheat flour.

    PubMed

    Kloots, Willem; Op den Kamp, Danielle; Abrahamse, Leo

    2004-12-29

    Iron deficiency is the most common nutritional disorder worldwide. Iron fortification of foods is considered to be the most cost-effective long-term approach to reduce iron deficiency. However, for fortified foods to be effective in reducing iron deficiency, the added iron must be sufficiently bioavailable. In this study, fortification of whole-grain wheat flour with different sources of iron was evaluated in vitro by measuring the amount of dialyzable iron after simulated gastrointestinal digestion of flour baked into chapatis and subsequent intestinal absorption of the released iron using Caco-2 cell layers. The dialyzability of iron from iron-fortified wheat flour was extremely low. Additions of 50 mg/kg iron to the flour in the form of ferrous sulfate, Ferrochel amino acid chelate, ferric amino acid chelate taste free (TF), Lipofer, ferrous lactate, ferrous fumarate, ferric pyrophosphate, carbonyl iron, or electrolytic iron did not significantly increase the amount of in vitro dialyzable iron after simulated gastrointestinal digestion. In contrast, fortification of flour with SunActive Fe or NaFeEDTA resulted in a significant increase in the amount of in vitro dialyzable iron. Relative to iron from ferrous sulfate, iron from SunActive Fe and NaFeEDTA appeared to be 2 and 7 times more available in the in vitro assay, respectively. Caco-2 cell iron absorption from digested chapatis fortified with NaFeEDTA, but not from those fortified with SunActive Fe, was significantly higher than from digested chapatis fortified with ferrous sulfate. On the basis of these results it appears that fortification with NaFeEDTA may result in whole-grain wheat flour that effectively improves the iron status. PMID:15612807

  7. In vitro iron availability from iron-fortified whole-grain wheat flour.

    TOXLINE Toxicology Bibliographic Information

    Kloots W; Op den Kamp D; Abrahamse L

    2004-12-29

    Iron deficiency is the most common nutritional disorder worldwide. Iron fortification of foods is considered to be the most cost-effective long-term approach to reduce iron deficiency. However, for fortified foods to be effective in reducing iron deficiency, the added iron must be sufficiently bioavailable. In this study, fortification of whole-grain wheat flour with different sources of iron was evaluated in vitro by measuring the amount of dialyzable iron after simulated gastrointestinal digestion of flour baked into chapatis and subsequent intestinal absorption of the released iron using Caco-2 cell layers. The dialyzability of iron from iron-fortified wheat flour was extremely low. Additions of 50 mg/kg iron to the flour in the form of ferrous sulfate, Ferrochel amino acid chelate, ferric amino acid chelate taste free (TF), Lipofer, ferrous lactate, ferrous fumarate, ferric pyrophosphate, carbonyl iron, or electrolytic iron did not significantly increase the amount of in vitro dialyzable iron after simulated gastrointestinal digestion. In contrast, fortification of flour with SunActive Fe or NaFeEDTA resulted in a significant increase in the amount of in vitro dialyzable iron. Relative to iron from ferrous sulfate, iron from SunActive Fe and NaFeEDTA appeared to be 2 and 7 times more available in the in vitro assay, respectively. Caco-2 cell iron absorption from digested chapatis fortified with NaFeEDTA, but not from those fortified with SunActive Fe, was significantly higher than from digested chapatis fortified with ferrous sulfate. On the basis of these results it appears that fortification with NaFeEDTA may result in whole-grain wheat flour that effectively improves the iron status.

  8. 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

  9. Cellular Iron Distribution in Bacillus anthracis

    PubMed Central

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

    2012-01-01

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

  10. Adipocyte iron regulates adiponectin and insulin sensitivity

    PubMed Central

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

    2012-01-01

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

  11. Adipocyte iron regulates adiponectin and insulin sensitivity.

    PubMed

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

    2012-10-01

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

  12. 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.

  13. Iron deficiency anemia: evaluation and management.

    PubMed

    Short, Matthew W; Domagalski, Jason E

    2013-01-15

    Iron deficiency is the most common nutritional disorder worldwide and accounts for approximately one-half of anemia cases. The diagnosis of iron deficiency anemia is confirmed by the findings of low iron stores and a hemoglobin level two standard deviations below normal. Women should be screened during pregnancy, and children screened at one year of age. Supplemental iron may be given initially, followed by further workup if the patient is not responsive to therapy. Men and postmenopausal women should not be screened, but should be evaluated with gastrointestinal endoscopy if diagnosed with iron deficiency anemia. The underlying cause should be treated, and oral iron therapy can be initiated to replenish iron stores. Parenteral therapy may be used in patients who cannot tolerate or absorb oral preparations. PMID:23317073

  14. In-situ identification of iron--zinc intermetallics in galvannealed steel coatings and iron oxides on exposed steel

    NASA Astrophysics Data System (ADS)

    Cook, Desmond C.

    1998-12-01

    Identification of all the compounds present in various coatings on steels is particularly difficult. Non-destructive, in-situ analysis is necessary if the fraction of each compound as well as its probable layering within the coating, is to be determined. Mssbauer spectroscopy is one valuable probe capable of uniquely identifying all iron compounds which form as coatings on steel and other iron alloy surfaces. To investigate a complete coating several criteria need to be considered. Removing the coating inevitably leaves a small and perhaps important component intact on the substrate. Therefore investigating the coating as it remains intact on the steel is important if complete identification of the iron compounds is to be made. This also preserves crystalline texture or preferred growth orientation within the coating to which the Mssbauer effect is sensitive. Mssbauer spectroscopy is a non-destructive technique which allows the integrity of the coating to be maintained during analysis. The combined transmission and scattering Mssbauer geometries generally result in accurate analysis of the coating composition. For the scattering geometry added information on compound layering is obtained if separate Mssbauer spectra are recorded using the re-emitted gamma rays as well as the conversion electrons and subsequently emitted X-rays. In-situ scattering Mssbauer spectroscopy has been used to characterize the iron--zinc alloys which form in the coatings of commercially produced corrosion resistant galvannealed sheet steel, a product of great interest to automotive producers. The results show that different amounts of four iron--zinc phases are present depending on the production conditions of the coating. The different phases are also distinctly layered. Mssbauer analyses of corrosion coatings formed on the surface of steels which have been exposed to different environments has also been undertaken. Materials include structural steels exposed for up to 25 years in marine, rural and industrial environments, and the interior surfaces of boiler pipes subjected to adverse chemical and temperature environments.

  15. 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

  16. 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

  17. 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

  18. Ineffective erythropoiesis and regulation of iron status in iron loading anaemias.

    PubMed

    Camaschella, Clara; Nai, Antonella

    2016-02-01

    The definition 'iron loading anaemias' encompasses a group of inherited and acquired anaemias characterized by ineffective erythropoiesis, low hepcidin levels, excessive iron absorption and secondary iron overload. Non-transfusion-dependent ?-thalassaemia is the paradigmatic example of these conditions that include dyserythropoietic and sideroblastic anaemias and some forms of myelodysplasia. Interrupting the vicious cycle between ineffective erythropoiesis and iron overload may be of therapeutic benefit in all these diseases. Induction of iron restriction by means of transferrin infusions, minihepcidins or manipulation of the hepcidin pathway prevents iron overload, redistributes iron from parenchymal cells to macrophage stores and partially controls anaemia in ?-thalassaemic mice. Inhibition of ineffective erythropoiesis by activin ligand traps improves anaemia and iron overload in the same models. Targeting iron loading orineffective erythropoiesis shows promise in preclinical studies; activin ligand traps are in clinical trials with promising results and may be useful in patients with ineffective erythropoiesis. PMID:26491866

  19. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  1. 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

  2. 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

  3. Fetal iron levels are regulated by maternal and fetal Hfe genotype and dietary iron

    PubMed Central

    Balesaria, Sara; Hanif, Rumeza; Salama, Mohamed F.; Raja, Kishor; Bayele, Henry K.; McArdle, Harry; Srai, Surjit K.S.

    2012-01-01

    Background Iron metabolism during pregnancy maintains fetal iron levels at the expense of the mother. The mechanism behind this regulation is still not clear despite recent advances. Here we examine the role of maternal and fetal Hfe, its downstream signaling molecule, hepcidin and dietary iron in the regulation of placental iron transfer. Design and Methods Hfe wild-type, knockout and heterozygote dams were fed iron deficient (12.5 ppm), adequate (50 ppm) and replete (150 ppm) iron diets and mated with heterozygote males to produce pups of all genotypes. Dams and pups were sacrificed at Day 18 of gestation; serum, placenta, body and liver iron parameters were measured. Protein and mRNA levels of various iron transporter genes were determined in duodenum, liver and placenta by Western blotting and real time PCR. Results Maternal liver iron levels were dependent on both dietary iron intake and Hfe genotype. Increasing iron levels in the maternal diet resulted in increased total iron in the fetus, primarily in the liver. However, fetuses of Hfe-knockout mothers showed further elevation of liver iron levels, concomitant with elevated expression of Tfr1, Dmt1 and Fpn in the placenta. Hfe-knockout fetuses that express low levels of liver hepcidin accumulated more iron in their liver than wild-type fetuses due to increased ferroportin levels in the placenta. Conclusions Maternal and fetal status, as well as dietary iron, is important in regulating iron transfer across placenta. Maternal Hfe regulates iron transfer by altering gene expression in the placenta. Fetal Hfe is important in regulating placental iron transfer by modulating fetal liver hepcidin expression. PMID:22180422

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

    PubMed

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

    2011-05-01

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

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

    PubMed

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

    2009-11-01

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

  6. Iron--what is melt?

    SciTech Connect

    Duba, A.G.

    1993-06-01

    The melting point of iron reported from a variety of phenomena observed in the laser-heated diamond-anvil-cell (DAC) and in shock wave studies differs widely. Although three groups of investigators, observing the same phenomena in the DAC are in good agreement to about 40 GPa, they disagree significantly with other measurements of melting point based on observation of different phenomena in the DAC. These latter data are in substantial agreement with some of the reported melting temperatures from two groups of investigators who measured temperature along the Hugoniot. However, a third group of investigators observe a sound velocity discontinuity along the Hugoniot and calculate a significantly lower temperature for melting. Melting point determination in iron is subject to the interpretation of physical phenomena, experimental errors which are probably larger than estimated, and perhaps undetected chemical reactions.

  7. Thermopower of thin iron films

    NASA Astrophysics Data System (ADS)

    Schepis, Randy; Schrder, Klaus

    1992-02-01

    Thin iron films were prepared by evaporation in a high vacuum system (pressure in the 10 -5 MPa range). The thermopower was measured in situ near room temperature as a function of film thickness. Iron films with rather high resistivity values showed a strong thickness effect of the Seeback coefficient, S, with the difference between S (bulk) and S (film) reaching values of up to (193) ?V/K for a sample 5 nm thick. The difference between S (bulk) and S (film) decreased with increasing d values. However, a sample with a resistance value of 50 ?? cm at d = 5 n had an S value which differed by less than 3 ?V/K from S (bulk).

  8. [Sport and iron in 2006].

    PubMed

    Schrago, G

    2006-07-26

    The iron deficiency is a current problem in common people, especially by the women. If the sport is good for the health, it's an additional riskfactor in endurance sports; by women with high trainingdoses, low Body Mass Index (BMI), high bloodlosses, there's a high risk for anaemia. The physiological update is a startpoint for guidelines about follow up of the sportsmen, athletes or amateurs. PMID:16927555

  9. Albumin holograms with iron ions

    NASA Astrophysics Data System (ADS)

    Ordez-Padilla, M. J.; Olivares-Prez, A.; Ortiz-Gutirrez, M.; Jurez-Ramrez, J. C.

    2014-02-01

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

  10. 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.

  11. Synthesis and Characterization of Stable IronIron Oxide CoreShell Nanoclusters for Environmental Applications

    SciTech Connect

    Antony, Jiji; Qiang, You; Baer, Donald R.; Wang, Chong M.

    2006-02-01

    Ironiron oxide coreshell nanoclusters are of great interest due to their potential applications as a remedy for environmental contamination. We report the room-temperature synthesis of coreshell ironiron 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 ironiron oxide coreshell nanocrystals are identified.

  12. 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.

  13. Sonochemical synthesis of amorphous iron

    NASA Astrophysics Data System (ADS)

    Suslick, Kenneth S.; Choe, Seok-Burm; Cichowlas, Andrzej A.; Grinstaff, Mark W.

    1991-10-01

    AMORPHOUS metallic alloys ('metallic glasses') lack long-range crystalline order and have unique electronic, magnetic and corrosion-resistant properties1-3. Their applications include use in power-transformer cores, magnetic storage media, cryothermometry and corrosion-resistant coatings. The production of metallic glasses is made difficult, however, by the extremely rapid cooling from the melt that is necessary to prevent crystallization. Cooling rates of about 105 to 107 K s-1 are generally required; for comparison, plunging red-hot steel into water produces cooling rates of only about 2,500 K s-1. Metallic glasses can be formed by splattering molten metal on a cold surface using techniques such as gun, roller or splat quenching4,5. Acoustic cavitation is known to induce extreme local heating in otherwise cold liquids, and to provide very rapid cooling rates6-11. Here we describe the synthesis of metallic-glass powders using the microscopically extreme (yet macroscopically mild) conditions induced by high-intensity ultrasound. The sonolysis of iron pentacarbonyl, a volatile organometallic compound, produces nearly pure amorphous iron. This amorphous iron powder is a highly active catalyst for the Fischer-Tropsch hydrogenation of carbon monoxide and for hydrogenolysis and dehydrogenation of saturated hydrocarbons.

  14. Current approach to iron chelation in children.

    PubMed

    Aydinok, Yesim; Kattamis, Antonis; Viprakasit, Vip

    2014-06-01

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

  15. What is new in iron overload?

    PubMed Central

    2007-01-01

    Children with severe chronic hemolytic anemia or congenital erythroblastopenia are transfusion dependent. Long-term transfusion therapy prolongs life but results in a toxic accumulation of iron in the organs. The human body cannot actively eliminate excess iron. Therefore, the use of a chelating agent is required to promote excretion of iron. So far, iron chelation has been done by subcutaneous infusion of deferoxamine given over 10 h, 56days per week. Compliance is poor and chelation often insufficient. Ferritin measurements and sometimes liver biopsies are used to evaluate the iron burden in the body. At the present time, new iron chelators that can be given orally are available. Furthermore, magnetic resonance imaging (MRI) assessment of tissue iron is a noninvasive and highly reproducible method, which is able to quantitate organ iron burden. In conclusion, iron overload can be measured more accurately with noninvasive methods such as MRI. Deferasirox is a once-daily oral therapy for treating transfusional iron overload, which improves patient compliance and quality of life. PMID:17899187

  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. Iron, phytoplankton growth, and the carbon cycle.

    PubMed

    Street, Joseph H; Paytan, Adina

    2005-01-01

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

  18. The reproductive ecology of iron in women.

    PubMed

    Miller, Elizabeth M

    2016-01-01

    Reproductive ecology focuses on the sensitivity of human reproduction to environmental variation. While reproductive ecology has historically focused on the relationship between energy status and reproductive outcomes, iron status is equally critical to women's reproductive health, given the wide-ranging detrimental effects of iron-deficiency anemia on maternal and infant well-being. This review interprets the vast literature on iron status and women's reproduction through an evolutionary framework. First, it will critique the evidence for iron deficiency caused by blood loss during menstruation, reinterpreting the available data as ecological variation in menses within and between populations of women. Second, it will highlight the scant but growing evidence that iron status is implicated in fertility, a relationship that has deep evolutionary roots. Third, this review proposes a new hypothesis for the transfer of iron from mother to infant via pregnancy and breastfeeding: reproductive iron withholding. In this hypothesis, mothers transfer iron to infants in a manner that helps infants avoid iron-mediated infection and oxidative stress, but trades off with potential risk of maternal and infant iron deficiency. Finally, this review explores two main factors that can modify the relationship between iron status and the gestation-lactation cycle: (1) the relationship between long-term reproductive effort (parity) and iron status and (2) supplementation schemes before and during pregnancy. The review concludes by suggesting continued research into iron homeostasis in women using evolutionary, ecological, and biocultural frameworks. Am J Phys Anthropol 159:S172-S195, 2016. © 2016 Wiley Periodicals, Inc. PMID:26808104

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

    EPA Science Inventory

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

  20. 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…

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

    EPA Science Inventory

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

  2. 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...

  3. 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...

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

    EPA Science Inventory

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

  5. 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...

  6. 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...

  7. Modelling Iron-Bentonite Interactions

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  8. Compartmentalization and regulation of iron metabolism proteins protect male germ cells from iron overload.

    PubMed

    Leichtmann-Bardoogo, Yael; Cohen, Lyora A; Weiss, Avital; Marohn, Britta; Schubert, Stephanie; Meinhardt, Andreas; Meyron-Holtz, Esther G

    2012-06-15

    The universal importance of iron, its high toxicity, and complex chemistry present a challenge to biological systems in general and to protected compartments in particular. The high mitotic rate and avid mitochondriogenesis of developing male germ cells imply high iron requirements. Yet access to germ cells is tightly regulated by the blood-testis barrier that protects the meiotic and postmeiotic germ cells. To elucidate how iron is supplied to developing male germ cells, we analyzed iron deposition and iron transport proteins in testes of mice with iron overload and with genetic ablation of the iron regulators Hfe and iron regulatory protein 2. Iron accumulated mainly around seminiferous tubules, and only small amounts localized within the seminiferous tubules. The localization and regulation of proteins involved in iron import, storage, and export such as transferrin, transferrin receptor, the divalent metal transporter-1, cytosolic ferritin, and ferroportin strongly support a model of a largely autonomous iron cycle within seminiferous tubules. We show evidence that ferritin secretion from Sertoli cells may play an important role in iron acquisition of primary spermatocytes. During spermatogenic development iron is carried along from primary spermatocytes to spermatids, and from spermatids iron is recycled to the apical compartment of Sertoli cells, which traffic it back to a new generation of spermatocytes. Losses are replenished by the peripheral circulation. Such an internal iron cycle essentially detaches the iron homeostasis within the seminiferous tubule from the periphery and protects developing germ cells from iron fluctuations. This model explains how compartmentalization can optimize cellular and systemic nutrient homeostasis. PMID:22496346

  9. 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

  10. Malabsorption of iron as a cause of iron deficiency anemia in postmenopausal women

    PubMed Central

    Qamar, Khansa; Saboor, Muhammad; Qudsia, Fatima; Khosa, Shafi Muhammad; Moinuddin; Usman, Muhammad

    2015-01-01

    Objective: Malabsorption is one of the causes of iron deficiency anemia in postmenopausal women. The main objective of this study was to access the frequency of malabsorption in iron deficient anemic postmenopausal women. Methods: A total of 123 postmenopausal women were enrolled in the study. Of these 123 women, 50 were included as control group and 73 patients with comparable severity of anemia were the patient group. Two tablets of ferrous sulfate (200 mg/tablet) along with one tablet of vitamin C (500 mg) were given to all participants. Serum iron levels were determined on samples collected from all participants before and after the administration of ferrous sulfate. Difference between before and after serum iron levels of normal and patients were compared. Results: No change in serum iron between sample one and sample two represented malabsorption. Out of 73, 5 postmenopausal anemic patients showed no change in their serum iron level after the administration of ferrous sulfate. This study shows that frequency of malabsorption of iron in postmenopausal women is 6.8%. Conclusion: Malabsorption should be considered as a prevalent cause of iron deficiency anemia in postmenopausal women. It should be properly diagnosed and iron response should be monitored properly in postmenopausal women with IDA after oral iron therapy. If a postmenopausal woman does not show any response to oral iron therapy, she should be evaluated for iron loss (blood loss and/or malabsorption). Intravenous route should be used for the administration of iron in these patients. PMID:26101480

  11. 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.

  12. Dynamic control of hepatic Plasmodium numbers by hepcidin despite elevated liver iron during iron supplementation.

    PubMed

    Ferrer, Patricia; Castillo-Neyra, Ricardo; Roy, Cindy N; Sullivan, David J

    2016-01-01

    Treatment of iron deficiency anemia in malaria endemic areas is complicated as iron supplementation increases malaria risk while malaria decreases iron absorption. Here we measured the influence of hepcidin expression and non-heme iron during iron supplementation on hepatic Plasmodium berghei numbers in anemic and non-anemic mice. Despite elevated hepatic non-heme iron on the high iron diet, elevated hepcidin expression is associated with less parasite bioavailable iron and lower hepatic parasite loads in anemic, iron deficient mice after both two and six weeks of supplementation. A marginal trend to lower parasite hepatic numbers was seen in non-anemic, iron replete mice. In a transgenic model of severe anemia, mice with a deletion in Sec15l1, which reportedly have normal liver iron and normal hepcidin expression, there were no changes in liver parasite numbers or blood stage numbers or outcome in the lethal Plasmodium yoelii model. In summary during iron supplementation the lower hepatic malaria numbers are regulated more by hepcidin than the absolute level of non-heme hepatic iron. PMID:26384816

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2008-03-25

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

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

    PubMed Central

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

    2008-01-01

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

  16. INTEGRAL Results

    SciTech Connect

    Walter, Roland

    2005-11-22

    INTEGRAL is operational since more than two years and producing high quality data. The instruments are working almost perfectly. A selection of INTEGRAL results obtained on point sources are presented.

  17. Role of iron in neurodegenerative diseases.

    PubMed

    Li, Kai; Reichmann, Heinz

    2016-04-01

    Currently, we still lack effective measures to modify disease progression in neurodegenerative diseases. Iron-containing proteins play an essential role in many fundamental biological processes in the central nervous system. In addition, iron is a redox-active ion and can induce oxidative stress in the cell. Although the causes and pathology hallmarks of different neurodegenerative diseases vary, iron dyshomeostasis, oxidative stress and mitochondrial injury constitute a common pathway to cell death in several neurodegenerative diseases. MRI is capable of depicting iron content in the brain, and serves as a potential biomarker for early and differential diagnosis, tracking disease progression and evaluating the effectiveness of neuroprotective therapy. Iron chelators have shown their efficacy against neurodegeneration in a series of animal models, and been applied in several clinical trials. In this review, we summarize recent developments on iron dyshomeostasis in Parkinson's disease, Alzheimer's disease, Friedreich ataxia, and Huntington's disease. PMID:26794939

  18. Iron-Based Redox Switches in Biology

    PubMed Central

    Theil, Elizabeth C.

    2009-01-01

    Abstract By virtue of its unique electrochemical properties, iron makes an ideal redox active cofactor for many biologic processes. In addition to its important role in respiration, central metabolism, nitrogen fixation, and photosynthesis, iron also is used as a sensor of cellular redox status. Iron-based sensors incorporate Fe-S clusters, heme, and mononuclear iron sites to act as switches to control protein activity in response to changes in cellular redox balance. Here we provide an overview of iron-based redox sensor proteins, in both prokaryotes and eukaryotes, that have been characterized at the biochemical level. Although this review emphasizes redox sensors containing Fe-S clusters, proteins that use heme or novel iron sites also are discussed. Antioxid. Redox Signal. 11, 1029–1046. PMID:19021503

  19. 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.

  20. Teaching Integrity

    ERIC Educational Resources Information Center

    Saunders, Sue; Butts, Jennifer Lease

    2011-01-01

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

  1. Teaching Integrity

    ERIC Educational Resources Information Center

    Saunders, Sue; Butts, Jennifer Lease

    2011-01-01

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

  2. 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...

  3. 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)

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

    PubMed

    Santiago, Palacios

    2012-01-01

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

  5. Out of BalanceSystemic Iron Homeostasis in Iron-Related Disorders

    PubMed Central

    Steinbicker, Andrea U.; Muckenthaler, Martina U.

    2013-01-01

    Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism. PMID:23917168

  6. Genetic and Biochemical Analysis of High Iron Toxicity in Yeast

    PubMed Central

    Lin, Huilan; Li, Liangtao; Jia, Xuan; Ward, Diane McVey; Kaplan, Jerry

    2011-01-01

    Iron storage in yeast requires the activity of the vacuolar iron transporter Ccc1. Yeast with an intact CCC1 are resistant to iron toxicity, but deletion of CCC1 renders yeast susceptible to iron toxicity. We used genetic and biochemical analysis to identify suppressors of high iron toxicity in ?ccc1 cells to probe the mechanism of high iron toxicity. All genes identified as suppressors of high iron toxicity in aerobically grown ?ccc1 cells encode organelle iron transporters including mitochondrial iron transporters MRS3, MRS4, and RIM2. Overexpression of MRS3 suppressed high iron toxicity by decreasing cytosolic iron through mitochondrial iron accumulation. Under anaerobic conditions, ?ccc1 cells were still sensitive to high iron toxicity, but overexpression of MRS3 did not suppress iron toxicity and did not result in mitochondrial iron accumulation. We conclude that Mrs3/Mrs4 can sequester iron within mitochondria under aerobic conditions but not anaerobic conditions. We show that iron toxicity in ?ccc1 cells occurred under both aerobic and anaerobic conditions. Microarray analysis showed no evidence of oxidative damage under anaerobic conditions, suggesting that iron toxicity may not be solely due to oxidative damage. Deletion of TSA1, which encodes a peroxiredoxin, exacerbated iron toxicity in ?ccc1 cells under both aerobic and anaerobic conditions, suggesting a unique role for Tsa1 in iron toxicity. PMID:21115478

  7. 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...

  8. Non-Invasive Methods for Iron Concentration Assessment

    NASA Astrophysics Data System (ADS)

    Carneiro, Antonio A. O.; Baffa, Oswaldo; Angulo, Ivan L.; Covas, Dimas T.

    2002-08-01

    Iron excess is commonly observed in patients with transfusional iron overload. The iron chelation therapy in these patients require accurate determination of the magnitude of iron excess. The most promising method for noninvasive assessment of iron stores is based on measurements of hepatic magnetic susceptibility.

  9. 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.

  10. 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 Mssbauer spectroscopy (CEMS) and soft x-ray absorption spectroscopy (SXAS) studies shows that the film crystallizes in ZnS-type crystal structure.

  11. Weldability and hot ductility of iron aluminides

    SciTech Connect

    Ash, D.I.; Edwards, G.R. . Center for Welding and Joining Research); David, S.A. )

    1991-05-01

    The weldability of iron aluminide alloys is discussed. Although readily welded with electron beam (EB) and gas-tungsten arc (GTA) techniques, iron aluminides are sometimes susceptible to cracking during cooling when welded with the GTA welding process. Taken into account are the effects of microstructural instability (grain growth), weld heat input (cooling rate) and environment on the hot ductility of an iron aluminide alloy designated FA-129. 64 refs., 59 figs., 3 tabs.

  12. Synthesis of iron based hydrocracking catalysts

    SciTech Connect

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

    1993-05-25

    A method of preparing an iron based hydrocracking catalyst is described, comprising reacting iron (111) oxide powders and elemental sulfur 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 (111) oxide at a temperature in the range of from about 180 C to about 240 C for a time in the range of from about 0 to about 8 hours.

  13. 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.

  14. 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.

  15. 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.

  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. High toughness-high strength iron alloy

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  18. 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.

  19. 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

  20. Self-assembling iron silicide nanobars and structure on silicon wafer by microwave plasma method

    NASA Astrophysics Data System (ADS)

    Xu, Bei-Xue; Zhang, Yang; Zhu, He-Sun; Shen, De-Zhong; Wu, JinLei; Xue, Z. Q.; Wu, Q. D.

    2005-02-01

    In this paper, we report a kind of novel belt-like nanostructure of iron silicide, which we call nanobars, synthesized on silicon (001) substrate by microwave plasma method. The iron silicide nanobars were found to be of metallic ?-FeSi2 with tetragonal symmetry (a=b=0.2695nm and c=0.5390nm) by energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. The scanning electron microscope (SEM) morphology indicates that the nanobars, with lengths typically up to several micrometres, widths in the range of 20-200 nm and thickness of 10-100 nm, self-assembly align along <110> directions on (001) silicon substrate and form network structure. The possible self-assembly growth mechanism of iron silicide nanobars was discussed. It is suggested that the optimal matching directions, the reconstruction in high temperature, and the interaction between original depositional iron nanoparticles by the magnetization of microwave magnetic field are the three factors that caused the formation and orientation of iron silicide nanobars. The special structure and self-assembly growth mechanism of iron silicide nanobars might be used in MEMS and NEMS fabricating or self-assembling carbon nanotubes integrated nanocircuits from the bottom up.