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1

Flame atomic absorption spectrometric determination of zinc after colloid precipitate flotation with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors  

Microsoft Academic Search

Colloid flotation of zinc from fresh water with a combination of two collectors, hydrated iron(III) oxide (Fe2O3·xH2O) and iron(III) tetramethylenedithiocarbamate (Fe(TMDTC)3), permits rapid separation of the precipitate before its atomic absorption spectrometric (AAS) analysis. All important parameters necessary for the successful flotation like optimal mass of collectors, pH of the medium, electrokinetic potential of the collector particle surfaces, type of

Katarina ?undeva; Traj?e Stafilov

1997-01-01

2

Reduction of aromatic nitro compounds with hydrazine hydrate in the presence of an iron oxide\\/hydroxide catalyst. III. The selective reduction of nitro groups in aromatic azo compounds  

Microsoft Academic Search

The study on the range of applications of a cheap iron oxide\\/hydroxide modification as a H-transfer catalyst opened up a promising new route for the selective reduction of nitro groups in aromatic azo compounds. A series of monosubstituted 3- and 4-nitrophenylazobenzenes were reduced selectively by hydrazine hydrate in the presence of the iron oxide\\/hydroxide catalyst. The selectivity for the nitro

Max Lauwiner; Ronny Roth; Paul Rys

1999-01-01

3

Density functional theory calculations on the complexation of p-arsanilic acid with hydrated iron oxide clusters: structures, reaction energies, and transition states.  

PubMed

Aromatic organoarsenicals, such as p-arsanilic acid (pAsA), are still used today as feed additives in the poultry and swine industries in developing countries. Through the application of contaminated litter as a fertilizer, these compounds enter the environment and interact with reactive soil components such as iron and aluminum oxides. Little is known about these surface interactions at the molecular level. We report density functional theory (DFT) calculations on the energies, optimal geometries, and vibrational frequencies for hydrated pAsA/iron oxide complexes, as well as changes in Gibbs free energy, enthalpy, and entropy for various types of ligand exchange reactions leading to both inner- and outer-sphere complexes. Similar calculations using arsenate are also shown for comparison, along with activation barriers and transition state geometries between inner-sphere complexes. Minimum energy calculations show that the formation of inner- and outer-sphere pAsA/iron oxide complexes is thermodynamically favorable, with the monodentate mononuclear complexes being the most favorable. Interatomic As-Fe distances are calculated to be between 3.3 and 3.5 Å for inner-sphere complexes and between 5.2 and 5.6 Å for outer-sphere complexes. In addition, transition state calculations show that activation energies greater than 23 kJ/mol are required to form the bidentate binuclear pAsA/iron oxide complexes, and that formation of arsenate bidentate binuclear complexes is thermodynamically -rather than kinetically- driven. Desorption thermodynamics using phosphate ions show that reactions are most favorable using HPO4(2-) species. The significance of our results for the overall surface complexation mechanism of pAsA and arsenate is discussed. PMID:25007345

Adamescu, Adrian; Hamilton, Ian P; Al-Abadleh, Hind A

2014-07-31

4

Enzymes of respiratory iron oxidation  

SciTech Connect

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

Blake, R. II.

1991-01-01

5

21 CFR 73.3125 - Iron oxides.  

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

2014-04-01

6

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

7

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

8

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

9

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

10

Competitive Oxidation and Hydration During Aqueous Alteration of Asteroids  

NASA Technical Reports Server (NTRS)

Introduction: Studies of chondrites show that incorporation of H2O ice during formation of asteroids followed by radioactive heating caused partial oxidation and hydration of primary reduced and anhydrous rocks. Oxidation of kamacite, phosphides, troilite and organic polymers occurred through consumption of water s oxygen and release of H2. Hydration caused formation of serpentine, saponite, chlorite, talc and hydrated salts. Since H2O was the major reactant in oxidation and hydration, these processes could have been competitive. Redox reactions in asteroids should have been closely connected to hydration (dehydration) during aqueous alteration and thermal metamorphism. For example, dehydration and reduction release H2O that can be consumed in oxidation and hydration, respectively. We model asteroidal processes in order to quantify the fate of H2O and water s oxygen in major redox and hydration/dehydration reactions. Model: Equilibrium compositions in the gas-solid-liquid

Zolotov, M. Y.; Mironenko, M. V.; Shock, E. L.

2005-01-01

11

Anaerobic oxidation of methane above gas hydrates at Hydrate Ridge, NE Pacific Ocean  

Microsoft Academic Search

At Hydrate Ridge (HR), Cascadia convergent margin, surface sediments contain mas- sive gas hydrates formed from methane that ascends together with fluids along faults from deeper reservoirs. Anaerobic oxidation of methane (AOM), mediated by a microbial consortium of archaea and sulfate-reducing bacteria, generates high concentrations of hydrogen sulfide in the surface sediments. The production of sulfide supports chemosynthetic communities that

Tina Treude; Antje Boetius; Katrin Knittel; Klaus Wallmann; Bo Barker Jørgensen

2003-01-01

12

Recovery of iron oxide from coal fly ash  

DOEpatents

A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

Dobbins, Michael S. (Ames, IA); Murtha, Marlyn J. (Ames, IA)

1983-05-31

13

Vacancy coalescence during oxidation of iron nanoparticles  

SciTech Connect

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

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

2007-06-14

14

Iron oxidation by Thiobacillus ferrooxidans  

SciTech Connect

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

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

1991-12-31

15

Carcinogenesis studies with iron oxides.  

PubMed

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

Steinhoff, D; Mohr, U; Hahnemann, S

1991-01-01

16

REMOVAL OF METAL IONS FROM WATER SOLUTIONS BY IRON\\/COBALT OXIDE COATED KERAMZITE  

Microsoft Academic Search

A method for coating hydrated iron, cobalt and iron\\/cobalt oxide on the surface of keramzite sand was developed. The coating parameters (pH, amount of coated metal, molar ratio Co\\/Fe, temperature of modification and time of treatment) controlling sorption ability of the coated layer were determined. The iron\\/cobalt coated keramzite thermally activated at 450°C obtained at a molar ratio Co\\/Fe-0.516 is

R. Y. Stefanova

2001-01-01

17

Iron, Oxidative Stress and Gestational Diabetes  

PubMed Central

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

Zhuang, Taifeng; Han, Huijun; Yang, Zhenyu

2014-01-01

18

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

19

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

20

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

21

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

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

2014-10-01

22

Iron Homeostasis, Oxidative Stress, and DNA Damage  

Microsoft Academic Search

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

Rogerio Meneghini

1997-01-01

23

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

PubMed Central

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

Brock, T D; Gustafson, J

1976-01-01

24

Tannin biosynthesis of iron oxide nanoparticles  

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

25

Platinum attachments on iron oxide nanoparticle surfaces  

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

26

Platinum Attachments on Iron Oxide Nanoparticle Surfaces  

SciTech Connect

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

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

2010-04-30

27

Ferrous iron oxidation by anoxygenic phototrophic bacteria  

Microsoft Academic Search

NATURAL oxidation of ferrous to ferric iron by bacteria such as Thiobacillus ferrooxidans or Gallionella ferruginea1, or by chemical oxidation2,3 has previously been thought always to involve molecular oxygen as the electron acceptor. Anoxic photochemical reactions4-6 or a photobiological process involving two photosystems7-9 have also been discussed as mechanisms of ferrous iron oxidation. The knowledge of such processes has implications

Friedrich Widdel; Sylvia Schnell; Silke Heising; Armin Ehrenreich; Bernhard Assmus; Bernhard Schink

1993-01-01

28

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2011 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...Identity. The color additives iron oxides consist...amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2011-04-01

29

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2010 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...Identity. The color additives iron oxides consist...amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2010-04-01

30

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2013 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...Identity. The color additives iron oxides consist...amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2013-04-01

31

21 CFR 73.2250 - Iron oxides.  

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...Identity. The color additives iron oxides consist...amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2014-04-01

32

21 CFR 73.2250 - Iron oxides.  

Code of Federal Regulations, 2012 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...Identity. The color additives iron oxides consist...amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2012-04-01

33

Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction  

Microsoft Academic Search

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

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

2006-01-01

34

Synthesis and characterization of nanostructure hydrous iron–titanium binary mixed oxide for arsenic sorption  

Microsoft Academic Search

Synthesis of nanostructure hydrous iron–titanium binary mixed oxide (NHITBMO) had been reported by a simple method, and characterized\\u000a by the X-ray diffraction (XRD), thermal analysis, transmission electron microscope (TEM), Föurier Transform Infrared (FTIR),\\u000a surface area, and zero surface charge pH (pHzpc). The synthetic oxide was hydrated and microcrystalline with 77.8 m2 g?1 BET surface area. The particle size (nm) calculated using XRD

Kaushik Gupta; Shyamal Saha; Uday Chand Ghosh

2008-01-01

35

Platinum attachments on iron oxide nanoparticle surfaces  

Microsoft Academic Search

Platinum nanoparticles supported on metal oxide surfaces have shown great potential as heterogeneous catalysts to accelerate electrochemical processes, such as the oxygen reduction reaction in fuel cells. Recently, the use of magnetic supports has become a promising research topic for easy separation and recovery of catalysts using magnets, such as Pt nanoparticles supported on iron oxide nanoparticles. The attachment of

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

2010-01-01

36

IRON OXIDE NANOPARTICLE-INDUCED OXIDATIVE STRESS AND INFLAMMATION  

EPA Science Inventory

Nanoparticle Physicochemical Characterizations We first focused on creating NP systems that could be used to test our hypotheses and assessing their stability in aqueous media. The iron oxide NP systems were not stable in cell culture medium o...

37

Iron oxides stimulate sulfate-driven anaerobic methane oxidation in seeps.  

PubMed

Seep sediments are dominated by intensive microbial sulfate reduction coupled to the anaerobic oxidation of methane (AOM). Through geochemical measurements of incubation experiments with methane seep sediments collected from Hydrate Ridge, we provide insight into the role of iron oxides in sulfate-driven AOM. Seep sediments incubated with (13)C-labeled methane showed co-occurring sulfate reduction, AOM, and methanogenesis. The isotope fractionation factors for sulfur and oxygen isotopes in sulfate were about 40‰ and 22‰, respectively, reinforcing the difference between microbial sulfate reduction in methane seeps versus other sedimentary environments (for example, sulfur isotope fractionation above 60‰ in sulfate reduction coupled to organic carbon oxidation or in diffusive sedimentary sulfate-methane transition zone). The addition of hematite to these microcosm experiments resulted in significant microbial iron reduction as well as enhancing sulfate-driven AOM. The magnitude of the isotope fractionation of sulfur and oxygen isotopes in sulfate from these incubations was lowered by about 50%, indicating the involvement of iron oxides during sulfate reduction in methane seeps. The similar relative change between the oxygen versus sulfur isotopes of sulfate in all experiments (with and without hematite addition) suggests that oxidized forms of iron, naturally present in the sediment incubations, were involved in sulfate reduction, with hematite addition increasing the sulfate recycling or the activity of sulfur-cycling microorganisms by about 40%. These results highlight a role for natural iron oxides during bacterial sulfate reduction in methane seeps not only as nutrient but also as stimulator of sulfur recycling. PMID:25246590

Sivan, Orit; Antler, Gilad; Turchyn, Alexandra V; Marlow, Jeffrey J; Orphan, Victoria J

2014-10-01

38

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

NASA Astrophysics Data System (ADS)

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

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

2009-03-01

39

Plasmodynamic synthesis of ultradispersed iron oxides  

NASA Astrophysics Data System (ADS)

Results of a pilot study of direct plasmochemical synthesis of ultradispersed crystalline iron oxide phases in a high-speed pulse jet of iron-containing electrodischarge plasma that effluxes into a closed volume with the air atmosphere are presented. The synthesized powder contains all main oxide phases, including magnetite Fe3O4, maghemite ?-Fe2O3, and hematite ?-Fe2O3. An important feature of the method is the formation of the metastable ?-Fe2O3 phase under normal conditions. The minimum average size of coherently diffracting domains (CDD) (particles) of the magnetic phases is observed when they are synthesized at air pressure of 1.0 atm. The powders have high magnetic properties comparable with those of compact iron oxides.

Sivkov, A. A.; Naiden, E. P.; Saigash, A. S.; Gerasimov, D. Yu.

2013-07-01

40

A laboratory study of anaerobic oxidation of methane in the presence of methane hydrate  

Microsoft Academic Search

In order to mimic and study the process of anaerobic methane oxidation in methane hydrate regions we developed four high-pressure anaerobic bioreactors, designed to incubate environmental sediment samples, and enrich for populations of microbes associated with anaerobic methane oxidation (AMO). We obtained sediment inocula from a bacterial mat at the southern Hydrate Ridge, Cascadia, having cell counts approaching 1010 cells\\/cc.

R. Solem; D. Bartlett; M. Kastner; D. Valentine

2003-01-01

41

Water column methane oxidation adjacent to an area of active hydrate dissociation, Eel river Basin  

Microsoft Academic Search

The role of methane clathrate hydrates in the global methane budget is poorly understood because little is known about how much methane from decomposing hydrates actually reaches the atmosphere. In an attempt to quantify the role of water column methanotrophy (microbial methane oxidation) as a control on methane release, we measured water column methane profiles (concentration and ?13C) and oxidation

DAVID L. VALENTINE; Douglas C Blanton; WILLIAM S. REEBURGH; Miriam Kastner

2001-01-01

42

Iron oxide magnetic nanoparticles: A short review  

NASA Astrophysics Data System (ADS)

Magnetic nanoparticles have been enjoying great importance and wide scale applications during the last two decades due to their specific characteristics and applications. Iron oxide magnetic nanoparticles with appropriate surface chemistry have been implied in numerous applications such as biomedicine and cancer therapy, catalysis and in magnetic separation techniques. This review summarizes recent commercial, industrial and bio-engineering applications and brief study of the methods for the preparation of iron oxide magnetic nanoparticles with a control over the size, morphology and the magnetic properties. Some future applications of microwave irradiation for magnetic particle synthesis are also addressed.

Hasany, S. F.; Rehman, A.; Jose, R.; Ahmed, I.

2012-11-01

43

Adsorption of isoxaflutole degradates to aluminum and iron hydrous oxides.  

PubMed

Isoxaflutole is a preemergence herbicide that has been marketed as a substitute for atrazine. It is rapidly transformed to a more stable and soluble diketonitrile degradate (DKN) after field application and can further degrade to a benzoic acid degradate (BA) within soil. However, no previous research has been conducted to investigate DKN and BA sorption to metal oxide minerals. The primary objective of this research was to elucidate the interactions of DKN and BA with synthetic hydrous aluminum and iron oxides (HAO and HFO, respectively) to understand how variably charged minerals may influence adsorption of these compounds in soil. The herbicide degradates did adsorb to HAO and HFO, and the data were well described by the Freundlich model (R2 > 0.91), with Nvalues ranging from 0.89 to 1.2. Adsorption isotherms and Kd values demonstrate that BA is adsorbed to HFO to a greater extent than other degradate-mineral combinations that were studied. The degree of hysteresis between adsorption/desorption isotherms was characterized as slight (hysteresis index values < 1.7), suggesting weak DKN and BA retention to HFO and HAO oxide surfaces. Degradate adsorption was observed to greatly diminish as suspension pH increased. Attenuated total reflectance-Fourier transform infrared spectra show no evidence that DKN or BA adsorb to mineral surfaces as inner-sphere complexes under hydrated conditions. Instead DKN and BA adsorb to positively charged metal oxide surfaces as outer-sphere or diffuse ion swarm complexes via electrostatic attraction. This research indicates that metal oxides may serve as important retardants for DKN and BA migration through acidic soils enriched with aluminum and iron oxides. PMID:21520760

Wu, Si Hyun; Goyne, Keith W; Lerch, Robert N; Lin, Chung-Ho

2011-01-01

44

Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion  

DOEpatents

Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

Shen, Ming-Shing (Rocky Point, NY); Yang, Ralph T. (Middle Island, NY)

1980-01-01

45

Iron oxide nanoparticles as a contrast agent for thermoacoustic tomography  

E-print Network

radiation. The addition of an exogenous contrast agent improves image quality by more effectively converting microwave energy to heat. The use of iron oxide nanoparticles in MRI applications has been explored but super paramagnetic iron oxide nanoparticles...

Keho, Aaron Lopez

2009-06-02

46

Peptide functionalized superparamagnetic iron oxide nanoparticles as MRI contrast agents  

E-print Network

Peptide functionalized superparamagnetic iron oxide nanoparticles as MRI contrast agents Selim the MRI signal in tissues of interest. Superparamagnetic iron oxide nanoparticles (SPIONs) are used of water molecules in different tissues create distinct signal intensities that enable detection

Atalar, Ergin

47

21 CFR 73.200 - Synthetic iron oxide.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Synthetic iron oxide. 73.200 Section 73.200...CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2010-04-01

48

21 CFR 73.1200 - Synthetic iron oxide.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200...CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2013-04-01

49

21 CFR 73.1200 - Synthetic iron oxide.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200...CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2012-04-01

50

21 CFR 73.1200 - Synthetic iron oxide.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200...CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2011-04-01

51

21 CFR 73.200 - Synthetic iron oxide.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Synthetic iron oxide. 73.200 Section 73.200...CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2012-04-01

52

21 CFR 73.200 - Synthetic iron oxide.  

...2014-04-01 2014-04-01 false Synthetic iron oxide. 73.200 Section 73.200...CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2014-04-01

53

21 CFR 73.200 - Synthetic iron oxide.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Synthetic iron oxide. 73.200 Section 73.200...CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2011-04-01

54

21 CFR 73.200 - Synthetic iron oxide.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Synthetic iron oxide. 73.200 Section 73.200...CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2013-04-01

55

21 CFR 73.1200 - Synthetic iron oxide.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200...CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2010-04-01

56

21 CFR 73.1200 - Synthetic iron oxide.  

...2014-04-01 2014-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200...CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any...

2014-04-01

57

Magnetic coupling among spinel iron oxide microparticles by Mssbauer spectroscopy  

E-print Network

L-437 Magnetic coupling among spinel iron oxide microparticles by Mössbauer spectroscopy E. Tronc cristalline au sein d'agrégats est suggérée. Abstract 2014 Mössbauer spectra of hydrous spinel iron oxide to patterns of hydrous spinel iron oxide colloids worked correctly except for particles about 8 nm in size

Boyer, Edmond

58

Complement receptor type 2conjugated superparamagnetic iron oxide nanoparticles  

E-print Network

Method of detection: Magnetic resonance imaging (MRI) Source of signal: Iron oxide Activation: No StudiesComplement receptor type 2­conjugated superparamagnetic iron oxide nanoparticles [CR2-Fc-SPIO] Kam: Complement receptor type 2­conjugated gold/superparamagnetic iron oxide nanoparticles Abbreviated name: CR2

Levin, Judith G.

59

Nanostructured anodic iron oxide film as photoanode for water oxidation  

NASA Astrophysics Data System (ADS)

Two different configurations of photoanodes based on anodic iron oxide were investigated for photoelectrochemical water oxidation. A self-ordered and vertically oriented array of iron oxide nanotubes was obtained by anodization of pure iron substrate in an ethylene glycol based electrolyte containing 0.1M NH4F + 3 vol% water (EGWF solution) at 50 V for 15 min. Annealing of the oxide nanotubes in a hydrogen environment at 500 °C for 1 h resulted in a predominantly hematite phase. The second type of photoanode was obtained by a two-step anodization procedure. This process resulted in a two-layered oxide structure, a top layer of nano-dendrite morphology and a bottom layer of nanoporous morphology. This electrode configuration combined the better photocatalytic properties of the nano-dendritic iron oxide and better electron transportation behaviour of vertically oriented nano-channels. Annealing of these double anodized samples in an acetylene environment at 550 °C for 10 min resulted in a mixture of maghemite and hematite phases. Photocurrent densities of 0.74 mA cm-2 at 0.2 VAg/AgCl and 1.8 mA cm-2 at 0.5 VAg/AgCl were obtained under AM 1.5 illumination in 1M KOH solution. The double anodized samples showed high photoconductivity and more negative flat band potential (-0.8 VAg/AgCl), which are the properties required for promising photoanode materials.

Rangaraju, R. R.; Panday, A.; Raja, K. S.; Misra, M.

2009-07-01

60

Acid monolayer functionalized iron oxide nanoparticle catalysts  

NASA Astrophysics Data System (ADS)

Superparamagnetic iron oxide nanoparticle functionalization is an area of intensely active research, with applications across disciplines such as biomedical science and heterogeneous catalysis. This work demonstrates the functionalization of iron oxide nanoparticles with a quasi-monolayer of 11-sulfoundecanoic acid, 10-phosphono-1-decanesulfonic acid, and 11-aminoundecanoic acid. The carboxylic and phosphonic moieties form bonds to the iron oxide particle core, while the sulfonic acid groups face outward where they are available for catalysis. The particles were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), potentiometric titration, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectrometry (XPS), and dynamic light scattering (DLS). The sulfonic acid functionalized particles were used to catalyze the hydrolysis of sucrose at 80° and starch at 130°, showing a higher activity per acid site than the traditional solid acid catalyst Amberlyst-15, and comparing well against results reported in the literature for sulfonic acid functionalized mesoporous silicas. In sucrose catalysis reactions, the phosphonic-sulfonic nanoparticles (PSNPs) were seen to be incompletely recovered by an external magnetic field, while the carboxylic-sulfonic nanoparticles (CSNPs) showed a trend of increasing activity over the first four recycle runs. Between the two sulfonic ligands, the phosphonates produced a more tightly packed monolayer, which corresponded to a higher sulfonic acid loading, lower agglomeration, lower recoverability through application of an external magnetic field, and higher activity per acid site for the hydrolysis of starch. Functionalizations with 11-aminoundecanoic acid resulted in some amine groups binding to the surfaces of iron oxide nanoparticles. This amine binding is commonly ignored in iron oxide nanoparticle syntheses and functionalizations for biomedical and catalytic applications, affecting understandings of surface charge and other material properties.

Ikenberry, Myles

61

Bacterial methane oxidation in sea-floor gas hydrate: Significance to life in extreme environments  

Microsoft Academic Search

Samples of thermogenic hydrocarbon gases, from vents and gas hydrate mounds within a sea-floor chemosynthetic community on the Gulf of Mexico continental slope at about 540 m depth, were collected by research submersible. Our study area is characterized by low water temperature (mean =7 °C), high pressure (about 5400 kPa), and abundant structure II gas hydrate. Bacterial oxidation of hydrate-bound

Roger Sassen; Ian R. MacDonald; Norman L. Guinasso Jr.; Samantha Joye; Adolfo G. Requejo; Stephen T. Sweet; Javier Alcalá-Herrera; Debra A. Defreitas; David R. Schink

1998-01-01

62

Formulations for iron oxides dissolution  

DOEpatents

A mixture of a di- or polyphosphonic acid and a reductant wherein each is present in a sufficient amount to provide a synergistic effect with respect to the dissolution of metal oxides and optionally containing corrosion inhibitors and pH adjusting agents.

Horwitz, Earl P. (Argonne, IL); Chiarizia, Renato (Argonne, IL)

1992-01-01

63

Noncollinear coupling of iron layers through native iron oxide spacers  

SciTech Connect

We have found a magnetic superstructure in multilayers that consist of iron and its native oxide. Employing nuclear resonant scattering of synchrotron radiation from {sup 57}Fe probe layers, this manifests as 1/2-order Bragg peaks in the reflectivity curve. From the field dependence of their intensity, we deduce the existence of two magnetic sublattices that are canted by an angle of almost 90 deg. and rotate as one unit in low fields. For higher fields, the two sets of moments gradually align collinear to the external field. This behavior can be explained by a coupling of two adjacent Fe layers that is mediated by an antiferromagnetic order in the oxide spacer between them.

Diederich, Thomas; Couet, Sebastien; Roehlsberger, Ralf [Hamburger Synchrotronstrahlungslabor (HASYLAB), Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22603 Hamburg (Germany)

2007-08-01

64

Nitric oxide donor superparamagnetic iron oxide nanoparticles.  

PubMed

This work reports a new strategy for delivering nitric oxide (NO), based on magnetic nanoparticles (MNPs), with great potential for biomedical applications. Water-soluble magnetic nanoparticles were prepared through a co-precipitation method by using ferrous and ferric chlorides in acidic solution, followed by a mercaptosuccinic acid (MSA) coating. The thiolated nanoparticles (SH-NPs) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that the SH-NPs have a mean diameter of 10nm and display superparamagnetic behavior at room temperature. Free thiol groups on the magnetite surface were nitrosated through the addition of an acidified nitrite solution, yielding nitrosated magnetic nanoparticles (SNO-NPs). The amount of NO covalently bound to the nanoparticles surface was evaluated by chemiluminescense. The SNO-NPs spontaneously released NO in aqueous solution at levels required for biomedical applications. This new magnetic NO-delivery vehicle has a great potential to generate desired amounts of NO directed to the target location. PMID:25427482

Molina, Miguel M; Seabra, Amedea B; de Oliveira, Marcelo G; Itri, Rosangela; Haddad, Paula S

2013-03-01

65

Inhibited phase behavior of gas hydrates in graphene oxide: influences of surface and geometric constraints.  

PubMed

Porous materials have provided us unprecedented opportunities to develop emerging technologies such as molecular storage systems and separation mechanisms. Pores have also been used as supports to contain gas hydrates for the application in gas treatments. Necessarily, an exact understanding of the properties of gas hydrates in confining pores is important. Here, we investigated the formation of CO2, CH4 and N2 hydrates in non-interlamellar voids in graphene oxide (GO), and their thermodynamic behaviors. For that, low temperature XRD and P-T traces were conducted to analyze the water structure and confirm hydrate formation, respectively, in GO after its exposure to gaseous molecules. Confinement and strong interaction of water with the hydrophilic surface of graphene oxide reduce water activity, which leads to the inhibited phase behavior of gas hydrates. PMID:25232710

Kim, Daeok; Kim, Dae Woo; Lim, Hyung-Kyu; Jeon, Jiwon; Kim, Hyungjun; Jung, Hee-Tae; Lee, Huen

2014-11-01

66

Microanalysis of iron oxidation state in iron oxides using X Ray Absorption Near Edge Structure (XANES)  

NASA Technical Reports Server (NTRS)

An exploratory application of x ray absorption near edge structure (XANES) analysis using the synchrotron x ray microprobe was undertaken to obtain Fe XANES spectra on individual sub-millimeter grains in conventional polished sections. The experiments concentrated on determinations of Fe valence in a suite of iron oxide minerals for which independent estimates of the iron speciation could be made by electron microprobe analysis and x ray diffraction.

Sutton, S. R.; Delaney, J.; Bajt, S.; Rivers, M. L.; Smith, J. V.

1993-01-01

67

Candidate anode materials for iron production by molten oxide electrolysis  

E-print Network

Molten oxide electrolysis (MOE) has been identified by the American Iron and Steel Institute (AISI) as one of four possible breakthrough technologies to alleviate the environmental impact of iron and steel production. This ...

Paramore, James D

2010-01-01

68

Diverse use of iron oxide nanoparticles for anticancer therapy.  

E-print Network

??Recent development of a variety of superparamagnetic and ferromagnetic iron/iron oxide (Fe/Fe?O?) nanoparticles with different surface chemistry have been widely studied for numerous biological applications… (more)

Abayaweera, Gayani Sandeepa

2014-01-01

69

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

70

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

PubMed

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

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

2014-11-01

71

Homogeneous oxidation of water by iron complexes with macrocyclic ligands.  

PubMed

The activity of eleven separated iron complexes and nine in situ-generated iron complexes towards catalytic water oxidation have been examined in aqueous solutions with Ce(NH4)2(NO3)6 as the oxidant. Two iron complexes bearing tridentate and tetradentate macrocyclic ligands were found to be novel water oxidation catalysts. The one with tetradentate ligand exhibited a promising activity with a turnover number of 65 for oxygen evolution. PMID:24777911

Zhang, Biaobiao; Li, Fei; Yu, Fengshou; Cui, Honghua; Zhou, Xu; Li, Hua; Wang, Yong; Sun, Licheng

2014-06-01

72

Chemoenzymatic synthesis of monocyclic arene oxides and arene hydrates from substituted benzene substrates.  

PubMed

Enantiopure cis-dihydrodiol bacterial metabolites of substituted benzene substrates were used as precursors, in a chemoenzymatic synthesis of the corresponding benzene oxides and of a substituted oxepine, via dihydrobenzene oxide intermediates. A rapid total racemization of the substituted benzene 2,3-oxides was found to have occurred, via their oxepine valence tautomers, in accord with predictions and theoretical calculations. Reduction of a substituted arene oxide to yield a racemic arene hydrate was observed. Arene hydrates have also been synthesised, in enantiopure form, from the corresponding dihydroarene oxide or trans-bromoacetate precursors. Biotransformation of one arene hydrate enantiomer resulted in a toluene-dioxygenase catalysed cis-dihydroxylation to yield a benzene cis-triol metabolite. PMID:23532167

Boyd, Derek R; Sharma, Narain D; Ljubez, Vera; McGeehin, Peter K M; Stevenson, Paul J; Blain, Marine; Allen, Christopher C R

2013-05-14

73

Mineral resource of the month: iron oxide pigments  

USGS Publications Warehouse

The article discusses iron oxide pigments, which have been used as colorants since human began painting as they resist color change due to sunlight exposure, have good chemical resistance and are stable under normal ambient conditions. Cyprus, Italy and Spain are among the countries that are known for the production of iron oxide pigments. Granular forms of iron oxides and nano-sized materials are cited as developments in the synthetic iron oxide pigment industry which are being used in computer disk drives and nuclear magnetic resonance imaging.

U.S. Geological Survey

2008-01-01

74

Compact Zwitterion-Coated Iron Oxide Nanoparticles for Biological Applications  

E-print Network

The potential of superparamagnetic iron oxide nanoparticles (SPIONs) in various biomedical applications, including magnetic resonance imaging (MRI), sensing, and drug delivery, requires that their surface be derivatized ...

Wei, He

75

Suspension Hydrogen Reduction of Iron Oxide Concentrates  

SciTech Connect

The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

H.Y. Sohn

2008-03-31

76

Chemically synthesized hollow nanostructures in iron oxides  

NASA Astrophysics Data System (ADS)

In this work, we report a detailed study of the formation of hollow nanostructures in iron oxides. Core/shell Fe/Fe-oxide nanoparticles were synthesized by thermal decomposition of Fe(CO)5 at high temperature. It was found that 8 nm is the critical size above which the particles have a core/shell morphology, whereas below this size the particles exhibit a hollow morphology. Annealing the core/shell particles under air also leads to the formation of hollow spheres with a significant increase in the average particle size. In the case of the thermally activated Kirkendall process, the particles do not fully transform into hollow structures but many irregular shaped voids exist inside each particle. The 8 nm hollow particles are superparamagnetic at room temperature with a blocking temperature of 70 K whereas the core/shell particles are ferromagnetic.

Khurshid, Hafsa; Li, Wanfeng; Tzitzios, Vasillis; Hadjipanayis, George C.

2011-07-01

77

In Situ Iron Oxide Emplacement for Groundwater Arsenic Remediation  

E-print Network

Iron oxide-bearing minerals have long been recognized as an effective reactive media for arsenic-contaminated groundwater remediation. This research aimed to develop a technique that could facilitate in situ oxidative precipitation of Fe3+ in a soil...

Abia, Thomas Sunday

2012-02-14

78

Iron Accumulation with Age, Oxidative Stress and Functional Decline  

Microsoft Academic Search

Identification of biological mediators in sarcopenia is pertinent to the development of targeted interventions to alleviate this condition. Iron is recognized as a potent pro-oxidant and a catalyst for the formation of reactive oxygen species in biological systems. It is well accepted that iron accumulates with senescence in several organs, but little is known about iron accumulation in muscle and

Jinze Xu; Mitchell D. Knutson; Christy S. Carter; Christiaan Leeuwenburgh; Marcelo Hermes-Lima

2008-01-01

79

Sophorolipids-functionalized iron oxide nanoparticles.  

PubMed

Functional iron oxide nanoparticles (NP) have been synthesized in a one and a two-step method using a natural functional glycolipid belonging to the family of sophorolipids (SL). These compounds, whose open acidic form is highly suitable for nanoparticle stabilization, are readily obtained by a fermentation process of the yeast Candida bombicola (polymorph Starmerella bombicola) in large amounts. The final carbohydrate coated iron oxide nanoparticles represent interesting potentially biocompatible materials for biomedical applications. According to the synthesis strategy, magnetic properties can eventually be tuned, thus putting in evidence the direct effect of the glycolipid on the final material's structure (maghemite and ferrihydrite have been obtained here). A combination of FT-IR, Dynamic Light Scattering (DLS) and UV-Vis experiments shows that SL complex the nanoparticle surface via their accessible COOH group thus forming stable colloids, whose hydrodynamic diameter mostly varies between 10 nm and 30 nm, both in water and in KCl-containing (0.01 M and 2 M) solutions. The materials can stand multiple filtration steps (up to 10) at different extents, where the largest recorded average aggregate size is 100 nm. In general, materials synthesized at T = 80 °C display better stability and smaller size distribution than those obtained at room temperature. PMID:23247504

Baccile, Niki; Noiville, Romain; Stievano, Lorenzo; Van Bogaert, Inge

2013-02-01

80

Fabrication and Characterization of Iron Oxide Thin Films Prepared By the Thermal Oxidation of Iron  

NASA Astrophysics Data System (ADS)

Iron oxide thin films were deposited by electron beam (e-beam) evaporation from pure iron. Two types of evaporation were done. Firstly, iron was deposited in vacuum, and secondly, the reactive evaporation of iron was carried out in an oxygen atmosphere. Films were post-annealed in air in the temperature range 200 °C to 500 °C. The structural properties were investigated by X-ray diffraction, revealed the growth of ?-Fe2O 3 (hematite). The films were polycrystalline with nanocrystallite size. The chemical properties of the films were determined from X-ray photoelectron spectroscopy, and highly reactive nature of iron oxide films was elucidated. The surface morphological properties of the films were determined using atomic force microscopy. The surface roughness and lateral mean grain size of the films were increased with annealing. The optical properties of the films, including the refractive index, extinction coefficient, absorption coefficient, and band gap were determined from spectrophotometric measurements. Films were highly transparent and exhibited high values of refractive indices. All the films had direct as well as indirect band gaps. The direct band gap values were 2.21 ± 0.03 eV and indirect band gap values were 1.98 ± 0.02 eV.

Saleem, Muhammad

81

Thermochemistry of iron manganese oxide spinels  

SciTech Connect

Oxide melt solution calorimetry has been performed on iron manganese oxide spinels prepared at high temperature. The enthalpy of formation of (Mn{sub x}Fe{sub 1-x}){sub 3}O{sub 4} at 298K from the oxides, tetragonal Mn{sub 3}O{sub 4} (hausmannite) and cubic Fe{sub 3}O{sub 4} (magnetite), is negative from x=0 to x=0.67 and becomes slightly positive for 0.670.6) spinels of intermediate compositions. The enthalpies of formation are discussed in terms of three factors: oxidation-reduction relative to the end-members, cation distribution, and tetragonality. A combination of measured enthalpies and Gibbs free energies of formation in the literature provides entropies of mixing. {delta}S{sub mix}, consistent with a cation distribution in which all trivalent manganese is octahedral and all other ions are randomly distributed for x>0.5, but the entropy of mixing appears to be smaller than these predicted values for x<0.4.

Guillemet-Fritsch, Sophie [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Navrotsky, Alexandra [Thermochemistry Facility and NEAT ORU, University of California at Davis, One Shields Avenue, Davis, CA 95616-877 (United States)]. E-mail: anavrotsky@ucdavis.edu; Tailhades, Philippe [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Coradin, Herve [Centre InterUniversitaire de Recherche et d'Ingenierie des Materiaux (CIRIMAT/LCMIE), Universite Paul Sabatier, Ba-hat timent 2R1, 118, route de Narbonne, 31062 Toulouse, Cedex 04 (France); Wang Miaojun [Thermochemistry Facility and NEAT ORU, University of California at Davis, One Shields Avenue, Davis, CA 95616-877 (United States)

2005-01-15

82

40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).  

...2014-07-01 2014-07-01 false Cobalt iron manganese oxide, carboxylic acid-modified...Chemical Substances § 721.10529 Cobalt iron manganese oxide, carboxylic acid-modified...substance identified generically as cobalt iron manganese oxide, carboxylic...

2014-07-01

83

40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Cobalt iron manganese oxide, carboxylic acid-modified...Chemical Substances § 721.10529 Cobalt iron manganese oxide, carboxylic acid-modified...substance identified generically as cobalt iron manganese oxide, carboxylic...

2013-07-01

84

Micronization of Iron Oxide Particles Using Gas Antisolvent Process  

Microsoft Academic Search

Iron oxide particles were micronized by supercritical carbon dioxide (CO2) as an antisolvent in a batch gas antisolvent (GAS) process. In the present study, the feasibility of GAS process to micronize the iron oxide particles using dimethyl sulfoxide (DMSO) as a solvent was investigated. In this direction, particle size and morphology changes were investigated with changing solution pressure (80–150 bar), temperature

Najmeh Vefgh; Feridun Esmaeilzadeh; Dariush Mowla; Ali Akbar Golchehreh

2012-01-01

85

Structural and optical properties of porous iron oxide  

NASA Astrophysics Data System (ADS)

The structural and optical properties of the novel porous iron oxide fabricated by wood template have been investigated. The obtained porous iron oxide was characterized to be ?- Fe 2O 3 by Fourier transform infrared and Raman spectroscopy. X-ray absorption fine structure measurement revealed that the bond length of Fe-O 1 of the porous iron oxide has good agreement with that reported for the ?- Fe 2O 3 crystal structure while the bond lengths for Fe-O 2 and Fe-Fe deviate slightly from those of the ?- Fe 2O 3 crystal structure. Photoluminescence from the porous iron oxide exhibited broad emission bands around 760 and 890 nm, which are believed to be due to the unique nanoscale structure of the porous iron oxide.

Ding, Jian; Fan, Tongxiang; Zhang, Di; Saito, Katsuhiko; Guo, Qixin

2011-05-01

86

Continuous biological ferrous iron oxidation in a submerged membrane bioreactor.  

PubMed

Microbial oxidation of ferrous iron may be available alternative method of producing ferric iron, which is a reagent used for removal of H2S from biogas. In this study, a submerged membrane bioreactor (MBR) system was employed to oxidize ferrous iron to ferric iron. In the submerged MBR system, we could keep high concentration of iron-oxidizing bacteria and high oxidation rate of ferrous iron. There was membrane fouling caused by chemical precipitates such as K-jarosite and ferric phosphate. However, a strong acidity (pH 1.75) of solution and low ferrous iron concentration (below 3000 mg/I) significantly reduced the fouling of membrane module during the bioreactor operation. A fouled membrane module could be easily regenerated with a 1 M of sulfuric acid solution. In conclusion, the submerged MBR could be used for high-density culture of iron-oxidizing bacteria and for continuous ferrous iron oxidation. As far as our knowledge concerns, this is the first study on the application of a submerged MBR to high acidic conditions (below pH 2). PMID:16003962

Park, D; Lee, D S; Park, J M

2005-01-01

87

Evaluation of Characterization Techniques for Iron Pipe Corrosion Products and Iron Oxide Thin Films  

Microsoft Academic Search

A common problem faced by drinking water studies is that of properly characterizing the corrosion products (CP) in iron pipescor synthetic Fe (hydr)oxides used to simulate the iron pipe used in municipal drinking-water systems. The present work compares the relative applicability of a suite of imaging and analytical techniques for the characterization of CPs and synthetic Fe oxide thin films

Thomas Borch; Anne K. Camper; Joel A. Biederman; Phillip W. Butterfield; Robin Gerlach; James E. Amonette

2008-01-01

88

Moessbauer spectroscopic study of phase conversions of an iron-containing oxide catalyst for oxidative dehydrogenation of butenes  

SciTech Connect

Moessbauer spectroscopy was used to study the structure of ..gamma..-Al/sub 2/O/sub 3/-supported iron oxide, which is catalytically active in the oxidative dehydrogenation of butenes to divinyl. The phase conversions of the catalyst were investigated after treating it in reducing (butenes) and reaction (butenes + oxygen + water vapor) media and after regeneration in a stream of oxygen. It is shown that the supported phase changes from a structure similar to hematite (..cap alpha..-Fe/sub 2/O/sub 3/) to spinel structure both under the effect of butenes and the reaction mixture. When this happens ion exchange occurs between the spinel and the support, with the formation of partly hydrated complexes of Fe/sup 2 +/ ions in an asymmetric environment of O/sup 2 -/ ions and OH/sup -/ groups of the lattice of the support. These complexes vanish upon reoxidation of the catalyst, and part of the spinel is oxidized to hematite.

Golub'ev, A.V.; Matveev, A.I.; Amirbekov, E.N.; Maksimov, Yu.V.; Suzdalev, I.P.

1988-06-01

89

Ecological succession among iron-oxidizing bacteria.  

PubMed

Despite over 125 years of study, the factors that dictate species dominance in neutrophilic iron-oxidizing bacterial (FeOB) communities remain unknown. In a freshwater wetland, we documented a clear ecological succession coupled with niche separation between the helical stalk-forming Gallionellales (for example, Gallionella ferruginea) and tubular sheath-forming Leptothrix ochracea. Changes in the iron-seep community were documented using microscopy and cultivation-independent methods. Quantification of Fe-oxyhydroxide morphotypes by light microscopy was coupled with species-specific fluorescent in situ hybridization (FISH) probes using a protocol that minimized background fluorescence caused by the Fe-oxyhydroxides. Together with scanning electron microscopy, these techniques all indicated that Gallionellales dominated during early spring, with L. ochracea becoming more abundant for the remainder of the year. Analysis of tagged pyrosequencing reads of the small subunit ribosomal RNA gene (SSU rRNA) collected during seasonal progression supported a clear Gallionellales to L. ochracea transition, and community structure grouped according to observed dominant FeOB forms. Axis of redundancy analysis of physicochemical parameters collected from iron mats during the season, plotted with FeOB abundance, corroborated several field and microscopy-based observations and uncovered several unanticipated relationships. On the basis of these relationships, we conclude that the ecological niche of the stalk-forming Gallionellales is in waters with low organic carbon and steep redoxclines, and the sheath-forming L. ochracea is abundant in waters that contain high concentrations of complex organic carbon, high Fe and Mn content and gentle redoxclines. Finally, these findings identify a largely unexplored relationship between FeOB and organic carbon. PMID:24225888

Fleming, Emily J; Cetini?, Ivona; Chan, Clara S; Whitney King, D; Emerson, David

2014-04-01

90

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

Microsoft Academic Search

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

Bergur V. Stefánsson; Börje Haraldsson; Ulf Nilsson

2011-01-01

91

Kinetics of zero valent iron nanoparticle oxidation in oxygenated water.  

PubMed

Zero valent iron (ZVI) nanoparticles are versatile in their ability to remove a wide variety of water contaminants, and ZVI-based bimetallic nanoparticles show increased reactivity above that of ZVI alone. ZVI nanoparticles degrade contaminants through the reactive species (e.g., OH*, H(2(g)), H(2)O(2)) that are produced during iron oxidation. Measurement and modeling of aqueous ZVI nanoparticle oxidation kinetics are therefore necessary to optimize nanoparticle design. Stabilized ZVI and iron-nickel nanoparticles of approximately 150 nm in diameter were synthesized through solution chemistry, and nanoparticle oxidation kinetics were determined via measured mass change using a quartz crystal microbalance (QCM). Under flowing aerated water, ZVI nanoparticles had an initial exponential growth behavior indicating surface-dominated oxidation controlled by migration of species (H(2)O and O(2)) to the surface. A region of logarithmic growth followed the exponential growth which, based on the Mott-Cabrera model of thin oxide film growth, suggests a reaction dominated by movement of species (e.g., iron cations and oxygen anions) through the oxide layer. The presence of ethanol or a nickel shell on the ZVI nanoparticles delayed the onset of iron oxidation and reduced the extent of oxidation. In oxygenated water, ZVI nanoparticles oxidized primarily to the iron oxide-hydroxide lepidocrocite. PMID:23130994

Greenlee, Lauren F; Torrey, Jessica D; Amaro, Robert L; Shaw, Justin M

2012-12-01

92

Iron oxide nanoparticle enhancement of radiation cytotoxicity  

PubMed Central

Iron oxide nanoparticles (IONPs) have been investigated as a promising means for inducing tumor cell-specific hyperthermia. Although the ability to generate and use nanoparticles that are biocompatible, tumor specific, and have the ability to produce adequate cytotoxic heat is very promising, significant preclinical and clinical development will be required for clinical efficacy. At this time it appears using IONP-induced hyperthermia as an adjunct to conventional cancer therapeutics, rather than as an independent treatment, will provide the initial IONP clinical treatment. Due to their high-Z characteristics, another option is to use intracellular IONPs to enhance radiation therapy without excitation with AMF (production of heat). To test this concept IONPs were added to cell culture media at a concentration of 0.2 mg Fe/mL and incubated with murine breast adenocarcinoma (MTG-B) cells for either 48 or 72 hours. Extracellular iron was then removed and all cells were irradiated at 4 Gy. Although samples incubated with IONPs for 48 hrs did not demonstrate enhanced post-irradiation cytotoxicity as compared to the non-IONP-containing cells, cells incubated with IONPs for 72 hours, which contained 40% more Fe than 48 hr incubated cells, showed a 25% decrease in clonogenic survival compared to their non-IONP-containing counterparts. These results suggest that a critical concentration of intracellular IONPs is necessary for enhancing radiation cytotoxicity. PMID:25301998

Mazur, Courtney M.; A.Tate, Jennifer; Strawbridge, Rendall R.; Gladstone, David J.; Hoopes, P. Jack

2014-01-01

93

Multiple hearth furnace for reducing iron oxide  

DOEpatents

A multiple moving hearth furnace (10) having a furnace housing (11) with at least two moving hearths (20) positioned laterally within the furnace housing, the hearths moving in opposite directions and each moving hearth (20) capable of being charged with at least one layer of iron oxide and carbon bearing material at one end, and being capable of discharging reduced material at the other end. A heat insulating partition (92) is positioned between adjacent moving hearths of at least portions of the conversion zones (13), and is capable of communicating gases between the atmospheres of the conversion zones of adjacent moving hearths. A drying/preheat zone (12), a conversion zone (13), and optionally a cooling zone (15) are sequentially positioned along each moving hearth (30) in the furnace housing (11).

Brandon, Mark M. (Charlotte, NC); True, Bradford G. (Charlotte, NC)

2012-03-13

94

PRECIPITATION CHEMISTRY OF MAGNESIUM SULFITE HYDRATES IN MAGNESIUM OXIDE SCRUBBING  

EPA Science Inventory

The report gives results of laboratory studies defining the precipitation chemistry of MgSO3 hydrates. The results apply to the design of Mg-based scrubbing processes for SO2 removal from combustion flue gas. In Mg-based scrubbing processes, MgSO3 precipitates as either trihydrat...

95

In situ embedment and growth of anhydrous and hydrated aluminum oxide particles on polyvinylidene fluoride (PVDF) membranes  

Microsoft Academic Search

Surface modification of polyvinylidene fluoride (PVDF) membranes was successfully performed by doping anhydrous and hydrated aluminum oxide particles (?-alumina, boehmite and gibbsite) through in situ particle embedment and subsequent crystal growth under a hydrothermal environment. The approach of particle embedment involves the dispersion of anhydrous or hydrated aluminum oxide particles in the water phase during PVDF membrane precipitation, and the

Xiao-Mao Wang; Xiao-Yan Li; Kaimin Shih

2011-01-01

96

Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.  

PubMed

Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. PMID:24673906

Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

2014-03-01

97

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

NASA Technical Reports Server (NTRS)

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

Napier, Mary E.; Stair, Peter C.

1992-01-01

98

Magnetization measurements and XMCD studies on ion irradiated iron oxide and core-shell iron/iron-oxide nanomaterials  

SciTech Connect

Magnetite (Fe3O4) and core-shell iron/iron-oxide (Fe/Fe3O4) nanomaterials prepared by a cluster deposition system were irradiated with 5.5 MeV Si2+ ions and the structures determined by x-ray diffraction as consisting of 100% magnetite and 36/64 wt% Fe/FeO, respectively. However, x-ray magnetic circular dichroism (XMCD) indicates similar surfaces in the two samples, slightly oxidized and so having more Fe3+ than the expected magnetite structure, with XMCD intensity much lower for the irradiated core-shell samples indicating weaker magnetism. X-ray absorption spectroscopy (XAS) data lack the signature for FeO, but the irradiated core-shell system consists of Fe-cores with ~13 nm of separating oxide crystallite, so it is likely that FeO exists deeper than the probe depth of the XAS (~5 nm). Exchange bias (Hex) for both samples becomes increasingly negative as temperature is lowered, but the irradiated Fe3O4 sample shows greater sensitivity of cooling field on Hex. Loop asymmetries and Hex sensitivities of the irradiated Fe3O4 sample are due to interfaces and interactions between grains which were not present in samples before irradiation as well as surface oxidation. Asymmetries in the hysteresis curves of the irradiated core/shell sample are related to the reversal mechanism of the antiferromagnetic FeO and possibly some near surface oxidation.

Kaur, Maninder; Qiang, You; Jiang, Weilin; Pearce, Carolyn; McCloy, John S.

2014-12-02

99

Interaction of fluorescent sensor with superparamagnetic iron oxide nanoparticles  

NASA Astrophysics Data System (ADS)

To sense superparamagnetic iron oxides (Fe2O3 and Fe3O4) nanocrystals a sensitive bioactive phenanthroimidazole based fluorescent molecule, 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d] imidazole has been designed and synthesized. Electronic spectral studies show that phenanthroimidazole is bound to the surface of iron oxide semiconductors. Fluorescent enhancement has been explained on the basis of photo-induced electron transfer (PET) mechanism and apparent binding constants have been deduced. Binding of phenanthroimidazole with iron oxide nanoparticles lowers the HOMO and LUMO energy levels of phenanthroimidazole molecule. Chemical affinity between the nitrogen atom of the phenanthroimidazole and Fe2+ and Fe3+ ions on the surface of the nano-oxide may result in strong binding of the phenanthroimidazole derivative with the nanoparticles. The electron injection from the photoexcited phenanthroimidazole to the iron oxides conduction band explains the enhanced fluorescence.

Karunakaran, Chockalingam; Jayabharathi, Jayaraman; Sathishkumar, Ramalingam; Jayamoorthy, Karunamoorthy

2013-06-01

100

Interaction of fluorescent sensor with superparamagnetic iron oxide nanoparticles.  

PubMed

To sense superparamagnetic iron oxides (Fe2O3 and Fe3O4) nanocrystals a sensitive bioactive phenanthroimidazole based fluorescent molecule, 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d] imidazole has been designed and synthesized. Electronic spectral studies show that phenanthroimidazole is bound to the surface of iron oxide semiconductors. Fluorescent enhancement has been explained on the basis of photo-induced electron transfer (PET) mechanism and apparent binding constants have been deduced. Binding of phenanthroimidazole with iron oxide nanoparticles lowers the HOMO and LUMO energy levels of phenanthroimidazole molecule. Chemical affinity between the nitrogen atom of the phenanthroimidazole and Fe(2+) and Fe(3+) ions on the surface of the nano-oxide may result in strong binding of the phenanthroimidazole derivative with the nanoparticles. The electron injection from the photoexcited phenanthroimidazole to the iron oxides conduction band explains the enhanced fluorescence. PMID:23562745

Karunakaran, Chockalingam; Jayabharathi, Jayaraman; Sathishkumar, Ramalingam; Jayamoorthy, Karunamoorthy

2013-06-01

101

Iron oxide amended biosand filters for virus removal.  

PubMed

Laboratory studies were performed to determine if the addition of iron oxides throughout biosand filter (BSF) media would increase virus removal due to adsorption. The proposed mechanism is electrostatic adsorption of negatively charged virion particles to positively charged iron oxides formed during the corrosion of zerovalent iron. Initial tests conducted using continuous flow, small-scale glass columns showed high MS2 bacteriophage removal in an iron-amended sand column (5log10) compared to a sand-only column (0.5log10) over 20 pore volumes. Additionally, two experiments with a column containing iron particles revealed 4log10 and 5log10 removal of rotavirus in the presence of 20 mg/L total organic carbon. Full-scale BSFs with iron particles removed>4log10 MS2 for the duration of the experiment (287 days), while BSF with steel wool removed>4log10 MS2 for the first 160 days. Plug flow for the BSF was shown to depend on uniformity between the iron oxide material and sand media grains. The results suggest that the duration of effective virus removal by iron-amended biosand filtration depends on source water conditions and the quantity and composition of iron material added. Overall, this study provides evidence that iron-amended BSFs may advance the field of point-of-use technologies and bring relief to millions of people suffering from waterborne diseases. PMID:21708394

Bradley, Ian; Straub, Anthony; Maraccini, Peter; Markazi, Sheila; Nguyen, Thanh H

2011-10-01

102

Immobilisation of arsenic by iron(II)-oxidizing bacteria  

NASA Astrophysics Data System (ADS)

Arsenic-contaminated groundwater is an environmental problem that affects about 1-2% of the world's population. As arsenic-contaminated water is also used for irrigating rice fields, the uptake of arsenic via rice is in some cases even higher than via drinking water. Arsenic is often of geogenic origin and in many cases bound to iron(III) minerals. Microbial iron(III) reduction leads to dissolution of Fe(III) minerals and thus the arsenic bound to these minerals is released to the environment. In turn, iron(II)-oxidizing bacteria have the potential to co-precipitate or sorb arsenic during iron(II) oxidation followed by iron(III) mineral formation. Here, we present work on arsenic co-precipitation and immobilization by anaerobic and aerobic iron(II)-oxidizing bacteria. Co-precipitation batch experiments with pure cultures of nitrate-dependent, phototrophic, and microaerophilic Fe(II)-oxidizing bacteria are used to quantify the amount of arsenic that can be immobilized during microbial iron mineral precipitation. Iron and arsenic speciation and redox state are determined by X- ray diffraction and synchrotron-based X-ray absorption methods (EXAFS, XANES). Microcosm experiments are set-up either with liquid media or with rice paddy soil amended with arsenic. Rice paddy soil from arsenic contaminated rice fields in China that include a natural population of Fe(II)-oxidizing microorganisms is used as inoculum. Dissolved and solid-phase arsenic and iron are quantified, Arsenic speciation is determined and the iron minerals are identified. Additionally, Arsenic uptake into the rice plant is quantified and a gene expression pattern in rice (Oryza sativa cv Gladia) is determined by microarrays as a response to the presence of Fe(II)-oxidizing bacteria.

Kappler, A.; Hohmann, C.; Winkler, E.; Muehe, M.; Morin, G.

2008-12-01

103

Surface modifications of iron oxide nanoparticles for biological applications  

E-print Network

Iron oxides magnetic nanoparticles (MPs) of high crystallinity, high magnetization, and size-monodispersity were synthesized with oleic acid as their native ligands. These hydrophobic and non-functionalized MPs have magnetic ...

Insin, Numpon

2011-01-01

104

RESEARCH PAPER Effects of iron oxide nanoparticles on polyvinyl alcohol  

E-print Network

RESEARCH PAPER Effects of iron oxide nanoparticles on polyvinyl alcohol: interfacial layer and bulk:1 and 14 nm for 50:1). The presence of polyvinyl alcohol (PVA) limits the particle growth (15 nm for 20

Guo, John Zhanhu

105

Electrochemical behavior of reactively sputtered iron-doped nickel oxide  

Microsoft Academic Search

Iron-doped nickel oxide films were deposited by reactive sputtering from elemental and alloy targets in a 20% oxygen\\/argon atmosphere and were characterized for use as oxygen evolution catalysts. The incorporation of iron reduced the overpotential required for oxygen evolution by as much as 300 mV at a current density of 100 mA\\/cm² compared to undoped nickel oxide deposited under similar

Eric L. Miller; R. E. Rocheleau

1997-01-01

106

Facile synthesis of magnetic iron oxide nanoparticles and their characterization  

NASA Astrophysics Data System (ADS)

Magnetic iron oxide nanoparticles are synthesized by suitable modification of the standard synthetic procedure without use of inert atmosphere and at room temperature. The facile synthesis procedure can be easily scaled up and is of important from industrial point of view for the commercial large scale production of magnetic iron oxide nanoparticles. The synthesized nanoparticles were characterized by thermal, dynamic light scattering, scanning electron microscopy and transmission electron microscopy analyses.

Jadhav, Sushilkumar A.; Patil, Suresh V.

2014-06-01

107

Process for removing soluble metal cations in iron oxide pigments  

SciTech Connect

This patent describes a process for removing soluble metal cations contained in transparent iron oxide pigments comprising washing the iron oxide pigment with a composition containing a ligand compound wherein the pigment after the washing has conductivity of less than about 500 ..mu..mho, wherein the quantity of the ligand compound is from about 0.1 to 5.0 percent by weight relative to the total pigment weight.

Patil, A.S.

1988-07-19

108

Photoreductive dissolution of colloidal iron oxides in natural waters  

Microsoft Academic Search

Size-separation (0.1-pm filtration and ultrafiltration) techniques and coulometric procedures have been used to investigate the photoreductive dissolution of iron oxides under conditions typical of natural waters. In the absence of organic agents, iron oxides are solubilized to varying degrees through photodissociation of ferric hydroxy groups at the colloid surface. The degree of dissolution is de- pendent principally on the chromophore

T. David Waite; Francois M. M. Morel

1984-01-01

109

Stem cell tracking using iron oxide nanoparticles  

PubMed Central

Superparamagnetic iron oxide nanoparticles (SPIONs) are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI) and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored. PMID:24729700

Bull, Elizabeth; Madani, Seyed Yazdan; Sheth, Roosey; Seifalian, Amelia; Green, Mark; Seifalian, Alexander M

2014-01-01

110

Stem cell tracking using iron oxide nanoparticles.  

PubMed

Superparamagnetic iron oxide nanoparticles (SPIONs) are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI) and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored. PMID:24729700

Bull, Elizabeth; Madani, Seyed Yazdan; Sheth, Roosey; Seifalian, Amelia; Green, Mark; Seifalian, Alexander M

2014-01-01

111

Optimization of iron analyses using ESI-MS : detection of iron oxide in pharmaceuticals.  

E-print Network

??Detection of iron oxide in pharmaceutical formulations using electrospray ionization mass spectrometry (ESI-MS) following iron complexation with 1,10-phenanthroline (Phen), 1-(2-pyridylazo)-2-naphthol (PAN), and 4-(2-pyridylazo)resorcinol (PAR) was… (more)

Susanto, Dendi

2009-01-01

112

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

NASA Astrophysics Data System (ADS)

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

Zhang, C. L.

2003-12-01

113

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...

114

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

PubMed

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

Bonnefoy, Violaine; Holmes, David S

2012-07-01

115

Analysis of iron oxide precipitates in constructed mine wastewater treatments  

SciTech Connect

The purpose or this research project is to characterize iron oxide precipitates collected from abandoned mine drainage (AMD) treatment facilities in order to determine whether these precipitates have possible commercial value. The treatment facilities use constructed wetlands to raise pH levels to near neutral levels and to remove iron and other heavy metals from AMD polluted water. The main commercial value of interest is in the use of pigments in products such as paints, clay and brick. The precipitates arc characterized for composition and quality against natural and synthetic commercial pigment products. Various processing techniques were developed for sample preparation. Analysis tests include: general pigment tests, heavy metals, anions, particle size, and particle composition. Results show that the iron oxide precipitates are chemically similar to the commercial iron oxide but will require additional processing to meet pigment qualifications.

Partezana, J.M. [Saint Vincent College, Latrobe, PA (United States)

1996-10-01

116

Iron release and oxidant damage in human myoblasts by divicine.  

PubMed

Divicine is an aglycone derived from vicine, a glucosidic compound contained in fava beans (Vicia faba major or broad beans). In this study, we investigated the effect of divicine on cultured human myoblasts from normal subjects, in order to see if the drug may induce signs of oxidant stress in these cells. Myoblasts incubated 24 hours in the presence of 1 mM divicine, showed an increase of carbonyl groups and 4-hydroxynonenal (4-HNE) bound to cell proteins, as well as a significant release of iron and lactate dehydrogenase in the culture medium. Desferrioxamine (DFO), an iron chelator, significantly prevented protein oxidation and formation 4-HNE adducts. Our results can be interpreted as indicating that divicine autooxidizes both at extracellular level and into myoblasts thus inducing the release of free iron, which initiates oxidation of cellular proteins and lipids. DFO protects the cells by subtracting the free iron both at intracellular and extracellular level. PMID:10794072

Ninfali, P; Perini, M P; Bresolin, N; Aluigi, G; Cambiaggi, C; Ferrali, M; Pompella, A

2000-01-01

117

In vitro demonstration of anaerobic oxidation of methane coupled to sulphate reduction in sediment from a marine gas hydrate area  

Microsoft Academic Search

Summary Anaerobic oxidation of methane (AOM) and sulphate reduction were examined in sediment samples from a marine gas hydrate area (Hydrate Ridge, NE Pacific). The sediment contained high numbers of microbial consortia consisting of organisms that affi- liate with methanogenic archaea and with sulphate- reducing bacteria. Sediment samples incubated under strictly anoxic conditions in defined mineral medium (salinity as in

Katja Nauhaus; Antje Boetius; Martin Kruger; Friedrich Widdel

2002-01-01

118

Iron Accumulation with Age, Oxidative Stress and Functional Decline  

PubMed Central

Identification of biological mediators in sarcopenia is pertinent to the development of targeted interventions to alleviate this condition. Iron is recognized as a potent pro-oxidant and a catalyst for the formation of reactive oxygen species in biological systems. It is well accepted that iron accumulates with senescence in several organs, but little is known about iron accumulation in muscle and how it may affect muscle function. In addition, it is unclear if interventions which reduced age-related loss of muscle quality, such as calorie restriction, impact iron accumulation. We investigated non-heme iron concentration, oxidative stress to nucleic acids in gastrocnemius muscle and key indices of sarcopenia (muscle mass and grip strength) in male Fischer 344 X Brown Norway rats fed ad libitum (AL) or a calorie restricted diet (60% of ad libitum food intake starting at 4 months of age) at 8, 18, 29 and 37 months of age. Total non-heme iron levels in the gastrocnemius muscle of AL rats increased progressively with age. Between 29 and 37 months of age, the non-heme iron concentration increased by approximately 200% in AL-fed rats. Most importantly, the levels of oxidized RNA in gastrocnemius muscle of AL rats were significantly increased as well. The striking age-associated increase in non-heme iron and oxidized RNA levels and decrease in sarcopenia indices were all attenuated in the calorie restriction (CR) rats. These findings strongly suggest that the age-related iron accumulation in muscle contributes to increased oxidative damage and sarcopenia, and that CR effectively attenuates these negative effects. PMID:18682742

Xu, Jinze; Knutson, Mitchell D.; Carter, Christy S.; Leeuwenburgh, Christiaan

2008-01-01

119

Iron-Sulfur Cluster Synthesis, Iron Homeostasis and Oxidative Stress in Friedreich Ataxia  

PubMed Central

Friedreich ataxia (FRDA) is an autosomal recessive, multi-systemic degenerative disease that results from reduced synthesis of the mitochondrial protein frataxin. Frataxin has been intensely studied since its deficiency was linked to FRDA in 1996. The defining properties of frataxin—(i) the ability to bind iron, (ii) the ability to interact with, and donate iron to, other iron-binding proteins, and (iii) the ability to oligomerize, store iron and control iron redox chemistry—have been extensively characterized with different frataxin orthologues and their interacting protein partners. This very large body of biochemical and structural data [reviewed in (Bencze et al., 2006)] supports equally extensive biological evidence that frataxin is critical for mitochondrial iron metabolism and overall cellular iron homeostasis and antioxidant protection [reviewed in (Wilson, 2006)]. However, the precise biological role of frataxin remains a matter of debate. Here, we review seminal and recent data that strongly link frataxin to the synthesis of iron-sulfur cluster cofactors (ISC), as well as controversial data that nevertheless link frataxin to additional iron-related processes. Finally, we discuss how defects in ISC synthesis could be a major (although likely not unique) contributor to the pathophysiology of FRDA via (i) loss of ISC-dependent enzymes, (ii) mitochondrial and cellular iron dysregulation, and (iii) enhanced iron-mediated oxidative stress. PMID:22917739

Vaubel, Rachael A.; Isaya, Grazia

2012-01-01

120

Synthesis of carbon-encapsulated iron nanoparticles via solid state reduction of iron oxide nanoparticles  

SciTech Connect

The encapsulation of iron nanoparticles in protective carbon cages leads to unique hybrid core-shell nanomaterials. Recent literature reports suggest that such nanocomposites can be obtained in a relatively simple process involving the solid state carbothermal reduction of iron oxide nanoparticles. This approach is very attractive because it does not require advanced equipment and consumes less energy in comparison to widely used plasma methods. The presented more-in-depth study shows that the carbothermal approach is sensitive to temperature and the process yield strongly depends on the morphology and crystallinity of the carbon material used as a reductant. - Graphical abstract: Reduction of iron oxide nanoparticles by carbon black at 1200 deg. C yields well crystallized carbon-encapsulated iron nanoparticles. Highlights: > Carbon-encapsulated iron nanoparticles were synthesized by carbothermal reduction of iron oxide nanoparticles. > The process has the highest selectivity at 1200 C. > Lower temperatures result in iron oxide nanoparticles wrapped in carbon matrix. > The encapsulation rate of Fe at 1200 deg. C was found to be 15%.

Bystrzejewski, M., E-mail: mibys@chem.uw.edu.pl [Dept of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw (Poland)

2011-06-15

121

Stabilization and functionalization of iron oxide nanoparticles for biomedical applications  

NASA Astrophysics Data System (ADS)

Superparamagnetic iron oxide nanoparticles (NPs) are used in a rapidly expanding number of research and practical applications in the biomedical field, including magnetic cell labeling separation and tracking, for therapeutic purposes in hyperthermia and drug delivery, and for diagnostic purposes, e.g., as contrast agents for magnetic resonance imaging. These applications require good NP stability at physiological conditions, close control over NP size and controlled surface presentation of functionalities. This review is focused on different aspects of the stability of superparamagnetic iron oxide NPs, from its practical definition to its implementation by molecular design of the dispersant shell around the iron oxide core and further on to its influence on the magnetic properties of the superparamagnetic iron oxide NPs. Special attention is given to the selection of molecular anchors for the dispersant shell, because of their importance to ensure colloidal and functional stability of sterically stabilized superparamagnetic iron oxide NPs. We further detail how dispersants have been optimized to gain close control over iron oxide NP stability, size and functionalities by independently considering the influences of anchors and the attached sterically repulsive polymer brushes. A critical evaluation of different strategies to stabilize and functionalize core-shell superparamagnetic iron oxide NPs as well as a brief introduction to characterization methods to compare those strategies is given.Superparamagnetic iron oxide nanoparticles (NPs) are used in a rapidly expanding number of research and practical applications in the biomedical field, including magnetic cell labeling separation and tracking, for therapeutic purposes in hyperthermia and drug delivery, and for diagnostic purposes, e.g., as contrast agents for magnetic resonance imaging. These applications require good NP stability at physiological conditions, close control over NP size and controlled surface presentation of functionalities. This review is focused on different aspects of the stability of superparamagnetic iron oxide NPs, from its practical definition to its implementation by molecular design of the dispersant shell around the iron oxide core and further on to its influence on the magnetic properties of the superparamagnetic iron oxide NPs. Special attention is given to the selection of molecular anchors for the dispersant shell, because of their importance to ensure colloidal and functional stability of sterically stabilized superparamagnetic iron oxide NPs. We further detail how dispersants have been optimized to gain close control over iron oxide NP stability, size and functionalities by independently considering the influences of anchors and the attached sterically repulsive polymer brushes. A critical evaluation of different strategies to stabilize and functionalize core-shell superparamagnetic iron oxide NPs as well as a brief introduction to characterization methods to compare those strategies is given. This article was submitted as part of a collection of articles on surface nanotechnology for biological applications. Other papers on this topic can be found in issue 2 of vol. 3 (2011). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale].

Amstad, Esther; Textor, Marcus; Reimhult, Erik

2011-07-01

122

The Oxidation Of Iron In A Gel Using Consumer Chemicals  

ERIC Educational Resources Information Center

An experiment is conducted for the oxidation of iron in a gel using consumer chemicals, which is pertinent to the students' understanding of redox chemistry and of the relative oxidation potentials of various metals. The experiment can be carried out with consumer chemicals that might be purchased at a supermarket and commonly found in the home.

Wright, Stephen W.; Folger, Marsha R.; Quinn, Ryan P.; Sauls, Frederick C.; Krone, Diane

2005-01-01

123

Evaluation of the thermodynamic properties of hydrated metal oxide nanoparticles by INS techniques  

SciTech Connect

In this contribution we will present a detailed methodology for the elucidation of the following aspects of the thermodynamic properties of hydrated metal oxide nanoparticles from high-resolution, low-temperature inelastic neutron scattering (INS) data: (i) the isochoric heat capacity and entropy of the hydration layers both chemi- and physisorbed to the particle surface; (ii) the magnetic contribution to the heat capacity of the nanoparticles. This will include the calculation of the vibrational density of states (VDOS) from the raw INS spectra, and the subsequent extraction of the thermodynamic data from the VDOS. This technique will be described in terms of a worked example namely, cobalt oxide (Co3O4 and CoO). To complement this evaluation of the physical properties of metal oxide nanoparticle systems, we will emphasise the importance of high-resolution, high-energy INS for the determination of the structure and dynamics of the water species, namely molecular (H2O) and dissociated water (OH, hydroxyl), confined to the oxide surfaces. For this component of the chapter we will focus on INS investigations of hydrated isostructural rutile (a-TiO2) and cassiterite (SnO2) nanoparticles. We will complete this discussion of nanoparticle analysis by including an appraisal of the INS instrumentation employed in such studies with particular focus on TOSCA [ISIS, Rutherford Appleton Laboratory (RAL), U.K.] and the newly developed spectrometer SEQUOIA [SNS, Oak Ridge National Laboratory (ORNL), U.S.A].

Spencer, Elinor [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Ross, Dr. Nancy [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Parker, Stewart F. [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Kolesnikov, Alexander I [ORNL] [ORNL

2013-01-01

124

Removal of phosphorus from solution using biogenic iron oxides.  

PubMed

Phosphorus removal by biogenic iron oxides was investigated, providing an initial characterization of a potentially regenerable iron-rich sorbent. The biogenic iron oxides were collected from a wetland ecosystem and were dominated by the sheaths of Leptothrix ochracea. Sorption kinetics followed a pseudo-1st order model (R(2)=0.998) with a rate constant of 0.154+/-0.013h(-1). The Langmuir isotherm adequately described sorption for all samples (R(2)=0.923-0.981); the Freundlich model was a better fit for only one of four samples. Maximum phosphorus sorption estimated using the Langmuir parameter ranged from 46.9+/-2.9 to 165.0+/-21.2mgP/gFe and was similar to other iron-rich substrates. Maximum sorption normalized to total solids ranged from 10.8+/-0.7 to 39.9+/-3.2mgP/g, which represented the highest published values for iron-rich substrates. The high sorption capacity with respect to both iron and solids warrants further evaluation of biogenic iron oxides as a substrate for phosphorus removal. PMID:19298996

Rentz, Jeremy A; Turner, Ian P; Ullman, Jeffrey L

2009-04-01

125

Biogeochemistry of Iron Oxidation in a Circumneutral Freshwater Habitat  

NASA Astrophysics Data System (ADS)

Iron(II) oxidation in natural waters at circumneutral pH, often regarded as an abiotic process, may be biologically- mediated when it occurs in iron-rich redox gradients. West Berry Creek, a small circumneutral tributary flowing through a mixed coniferous forest in Big Basin State Park, California, contains localized iron (hydr)oxide precipitates at points along its course where anoxic groundwater meets oxygenated creek water. These mixing zones establish redox gradients and iron-rich microbial mats that may create microenvironments that promote active biogeochemical cycling of Fe. Water sampling revealed strong correlations between the concentrations of aqueous inorganic species, suggesting a rock-weathering source for most of these solutes. Liquid chromatography-mass spectrometry detected significant concentrations of organic exudates, including low molecular mass organic acids and siderophores, indicating active biogeochemical cycling of iron is occurring in the creek. X-ray diffraction and elemental analysis showed the iron precipitates to be amorphous minerals, such as ferrihydrite. Microbial biofilm communities are associated with the iron (hydr)oxide deposits. Clone libraries developed from 16s rDNA sequences revealed the presence of microorganisms related to the neutrophilic iron- oxidizing bacteria Gallionella and Siderooxidans; in addition, micrographs suggest the widespread presence of sheath-forming bacteria (e.g., Leptothrix). Sequences from these libraries also indicated the presence of significant populations of organisms related to bacteria in the genera Pseudomonas, Sphingomonas, and Nitrospira. These geosymbiotic systems appear to be significant not only for the biogeochemical cycling of iron in the creek, but also for the cycling of organic species, inorganic nutrients, and trace metals.

Duckworth, O.; Homstrom, S.; Pena, J.; Zacharias, E.; Sposito, G.

2007-12-01

126

Possible involvement of iron-induced oxidative insults in neurodegeneration.  

PubMed

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

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

2015-02-19

127

Magnetic composites based on hybrid spheres of aluminum oxide and superparamagnetic nanoparticles of iron oxides  

NASA Astrophysics Data System (ADS)

Materials containing hybrid spheres of aluminum oxide and superparamagnetic nanoparticles of iron oxides were obtained from a chemical precursor prepared by admixing chitosan and iron and aluminum hydroxides. The oxides were first characterized with scanning electron microscopy, X-ray diffraction, and Mössbauer spectroscopy. Scanning electron microscopy micrographs showed the size distribution of the resulting spheres to be highly homogeneous. The occurrence of nano-composites containing aluminum oxides and iron oxides was confirmed from powder X-ray diffraction patterns; except for the sample with no aluminum, the superparamagnetic relaxation due to iron oxide particles were observed from Mössbauer spectra obtained at 298 and 110 K; the onset six line-spectrum collected at 20 K indicates a magnetic ordering related to the blocking relaxation effect for significant portion of small spheres in the sample with a molar ratio Al:Fe of 2:1.

Braga, Tiago P.; Vasconcelos, Igor F.; Sasaki, José M.; Fabris, J. D.; de Oliveira, Diana Q. L.; Valentini, Antoninho

2010-03-01

128

Adiabatic pulse preparation for imaging iron oxide nanoparticles.  

PubMed

Superparamagnetic iron oxide nanoparticles produce changes in the surrounding microscopic magnetic field. A method for generating contrast based on the application of an adiabatic preparation pulse and the failure of the adiabatic condition surrounding the nanoparticles is introduced in this article. Images were obtained in the presence and absence of an adiabatic preparation pulse and the difference was obtained. With the use of an adiabatic full passage pulse, the contrast in the difference image depends linearly on iron concentration up to 1 mM. The use of an adiabatic zero passage pulse resulted in higher sensitivity to nanoparticles compared to the adiabatic full passage, while maintaining linear concentration dependence to 0.1 mM. This technique was shown to be insensitive to magnetization transfer and B(0) inhomogeneity. With its linearity with iron concentration and insensitivity to changes in the main magnetic field, the new method is well suited for quantitative iron oxide nanoparticle imaging. PMID:22213366

Harris, Steven S; Mao, Hui; Hu, Xiaoping P

2012-04-01

129

Bacterial oxidation of ferrous iron at low temperatures.  

PubMed

This study comprises the first report of ferrous iron oxidation by psychrotolerant, acidophilic iron-oxidizing bacteria capable of growing at 5 degrees C. Samples of mine drainage-impacted surface soils and sediments from the Norilsk mining region (Taimyr, Siberia) and Kristineberg (Skellefte district, Sweden) were inoculated into acidic ferrous sulfate media and incubated at 5 degrees C. Iron oxidation was preceded by an approximately 3-month lag period that was reduced in subsequent cultures. Three enrichment cultures were chosen for further work and one culture designated as isolate SS3 was purified by colony isolation from a Norilsk enrichment culture for determining the kinetics of iron oxidation. The 16S rRNA based phylogeny of SS3 and two other psychrotolerant cultures, SS5 from Norilsk and SK5 from Northern Sweden, was determined. Comparative analysis of amplified 16S rRNA gene sequences showed that the psychrotolerant cultures aligned within Acidithiobacillus ferrooxidans. The rate constant of iron oxidation by growing cultures of SS3 was in the range of 0.0162-0.0104 h(-1) depending on the initial pH. The oxidation kinetics followed an exponential pattern, consistent with a first order rate expression. Parallel iron oxidation by a mesophilic reference culture of Acidithiobacillus ferrooxidans was extremely slow and linear. Precipitates harvested from the 5 degrees C culture were identified by X-ray diffraction as mixtures of schwertmannite (ideal formula Fe(8)O(8)(OH)(6)SO(4)) and jarosite (KFe(3)(SO(4))(2)(OH)(6)). Jarosite was much more dominant in precipitates produced at 30 degrees C. PMID:17304566

Kupka, Daniel; Rzhepishevska, Olena I; Dopson, Mark; Lindström, E Börje; Karnachuk, Olia V; Tuovinen, Olli H

2007-08-15

130

Role of Surface Precipitation in Copper Sorption by the Hydrous Oxides of Iron and Aluminum  

E-print Network

Role of Surface Precipitation in Copper Sorption by the Hydrous Oxides of Iron and Aluminum K. G precipitation; sorption; isotherms; X-ray diffraction; hydrous iron oxide; hydrous aluminum oxide; copper. INTRODUCTION Hydrous oxides of iron (HFO) and aluminum (HAO) are important mineral components of natural

Chorover, Jon

131

Control of ferrous iron oxidation within circumneutral microbial iron mats by cellular activity and autocatalysis.  

PubMed

Ferrous iron (Fe2+) oxidation by microbial iron mat samples, dominated by helical stalks of Gallionella ferruginea or sheaths of Leptothrix ochracea, was examined. Pseudo-first-order rate constants for the microbial mat samples ranged from 0.029 +/- 0.004 to 0.249 +/- 0.042 min(-1) and correlated well with iron content (R2 = 0.929). Rate constants for Na azide-treated (1 mM) samples estimated autocatalytic oxidation by iron oxide stalks or sheaths, with values ranging from 0.016 +/- 0.008 to 0.062 +/- 0.006 min(-1). Fe2+ oxidation attributable to cellular activities was variable with respect to sampling location and sampling time, with rate constants from 0.013 +/- 0.005 to 0.187 +/- 0.037 min(-1). Rates of oxidation of the same order of magnitude for cellular processes and autocatalysis suggested that bacteria harnessing Fe2+ as an energy source compete with their own byproducts for growth, not chemical oxidation (under conditions where aqueous oxygen concentrations are less than saturating). The use of cyclic voltammetry within this study for the simultaneous measurement of Fe2+ and oxygen allowed the collection of statistically meaningful and reproducible data, two factors that have limited aerobic, circumneutral, Fe2+ -oxidation rate studies. PMID:17937285

Rentz, Jeremy A; Kraiya, Charoenkwan; Luther, George W; Emerson, David

2007-09-01

132

Multimodal Iron Oxide Nanoparticles for Hybrid Biomedical Imaging  

PubMed Central

Iron oxide core nanoparticles are attractive imaging agents because their material properties allow the tuning of pharmacokinetics as well as attachment of multiple moieties to their surface. In addition to affinity ligands, these include fluorochromes and radioisotopes for detection with optical and nuclear imaging. As the iron oxide core can be detected by MRI, options for combining imaging modalities are manifold. Already, preclinical imaging strategies combine non-invasive imaging with higher resolution techniques such as intravital microscopy to gain unprecedented insight into steady state biology and disease. Going forward, hybrid iron oxide nanoparticles will likely help to merge modalities, creating a synergy that enables imaging in basic research and, potentially, also in the clinic. PMID:23065771

Heidt, Timo; Nahrendorf, Matthias

2012-01-01

133

Development of Novel Biopolymer/Synthetic-Polymer/Iron Oxide Nanocomposites  

NASA Astrophysics Data System (ADS)

In this work we report the successful development of a family of magnetic nanocomposites based on chitosan or/and polyamide 6 matrix with dispersed iron oxide nanoparticles synthesized by chemical co-precipitation. The iron oxide contents varied from 5 up to 23 wt%, the nanocomposites were studied by FTIR, UV-vis, TGA, XRD, TEM and magnetometry. The FTIR analysis demonstrates an interaction between the amide group of the polyamide 6 and the ceramic material. In formic acid, the nanocomposites absorb in the UV-Vis range, and the magnitude of the band gap (optical), calculated using the band of higher wavelength, is between 2.16 and 2.19 eV. In nanocomposites with chitosan/polyamide 6 matrix the developed morphologies are spherulites of polyamide 6 surrounded by chitosan, with the iron oxide particles presumably in the form of ferrihidryte. The measured magnetic properties revealed a superparamagnetic character on the studied specimens.

Mena Montoya, Marleth; Carranza, Sugeheidy; Hinojosa, Moisés; González, Virgilio

2009-03-01

134

Arsenate adsorption onto iron oxide amended rice husk char.  

PubMed

In this study, rice husks were charred at 550 °C in a partially sealed ceramic vessel for 30minutes to create a high specific surface area (SSA) rice husk char (RHC). The RHC was then amended with iron oxides using dissolved ferric nitrate, Fe(NO3)3?9H2O, to provide a surface chemistry conducive to arsenic adsorption. The 550 °C iron oxide amended rice husk char's (550 IOA-RHC's) SSA was nearly 2.5 orders of magnitude higher and the arsenate adsorptive level was nearly 2 orders of magnitude higher than those reported for iron oxide amended sand, thus indicating a positive relationship between post-amendment SSA and arsenate adsorptive levels. Rice husks were then charred at temperatures ranging from 450 °C to 1050 °C to create an even higher SSA material, which might further increase arsenate adsorptive levels. The 950 °C RHC was chosen for amendment due to its high SSA and feasibility of being produced in the field. Once amended, the 950 °C iron oxide amended rice husk char (950 IOA-RHC) improved the arsenate adsorption capacity by thus confirming a positive relationship, though not a linear relationship, between post-amendment SSA and arsenic adsorptive capacity. Further study demonstrated that post-amendment mesoporous volume and mesoporous surface area appear to be better indicators of arsenic adsorptive capacity than SSA or iron content. PMID:24529452

Cope, Christopher O; Webster, Damon S; Sabatini, David A

2014-08-01

135

Electrolytic photodissociation of chemical compounds by iron oxide electrodes  

DOEpatents

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor diode having visible light as its sole source of energy. The diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Somorjai, Gabor A. (Berkeley, CA); Leygraf, Christofer H. (Berkeley, CA)

1984-01-01

136

Electrolytic photodissociation of chemical compounds by iron oxide photochemical diodes  

DOEpatents

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor photochemical diode having visible light as its sole source of energy. The photochemical diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Somorjai, Gabor A. (Berkeley, CA); Leygraf, Christofer H. (Berkeley, CA)

1985-01-01

137

Unprecedented Selective Oxidation of Styrene Derivatives using a Supported Iron Oxide Nanocatalyst in Aqueous Medium  

EPA Science Inventory

Iron oxide nanoparticles supported on mesoporous silica-type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as a green oxidant. Catalysts could be easily recovered after completion of the reac...

138

Evolutionary relationships among sulfur- and iron-oxidizing eubacteria.  

PubMed Central

Some 37 reverse transcriptase, partial 16S rRNA sequences from sulfur- and/or iron-oxidizing eubacteria, including sequences from species of the genera Thiobacillus, Thiothrix, Thiomicrospira, Acidophilium, "Leptospirillum," Thiovulum, and Chlorobium, have been determined. In addition, 16S sequences from a number of unnamed sulfur- and/or iron-oxidizing bacteria from hydrothermal vent sites, from invertebrate-bacterial endosymbioses, and from various mineral recovery operations also have been determined. The majority of sequences place their bacterial donors in one or another of the subdivisions of the Proteobacteria. However, three unnamed facultatively thermophilic iron-oxidizing isolates, Alv, BC, and TH3, are affiliated with the gram-positive division. One H2S-oxidizer, from the genus Thiovulum, is affiliated with Campylobacter, Wolinella, and other genera in what appears to be a new subdivision of the Proteobacteria. Three "Leptospirillum"-helical vibrioid isolates, BU-1, LfLa, and Z-2, exhibit no clear phylum level affiliation at all, other than their strong relationship to each other. A picture is emerging of an evolutionary widespread capacity for sulfur and/or iron oxidation among the eubacteria. PMID:1729214

Lane, D J; Harrison, A P; Stahl, D; Pace, B; Giovannoni, S J; Olsen, G J; Pace, N R

1992-01-01

139

DETERMINATION OF THE RATES AND PRODUCTS OF FERROUS IRON OXIDATION IN ARSENIC-CONTAMINATED POND WATER.  

EPA Science Inventory

Dissolved ferrous iron and arsenic in the presence of insufficient oxygenated ground water is released into a pond. When the mixing of ferrous iron and oxygenated water within the pond occurs, the ferrous iron is oxidized and precipitated as an iron oxide. Groups of experiments...

140

Deposition rates of oxidized iron on Mars  

NASA Technical Reports Server (NTRS)

The reddened oxidized surface of Mars is indicative of temporal interactions between the Martian atmosphere and its surface. During the evolution of the Martian regolith, primary ferromagnesian silicate and sulfide minerals in basaltic rocks apparently have been oxidized to secondary ferric-bearing assemblages. To evaluate how and when such oxidized deposits were formed on Mars, information about the mechanisms and rates of chemical weathering of Fe(2+)-bearing minerals has been determined. In this paper, mechanisms and rates of deposition of ferric oxide phases on the Martian surface are discussed.

Burns, R. G.

1993-01-01

141

Consumption of biogenic nitric oxide in hydrated soil.  

PubMed

An experimental study was conducted in order to determine the relationship of nitric oxide (NO) consumption to water-filled pore space in soil. A test system that included the capability to blend gases, test soil samples, and analyze off-gases was used to conduct the study. The experimental set consisted of three replicates at five different levels of soil water content and three different levels of soil nitrogen in a sandy loam soil: unamended soil, soil fertilized at 56.2 kg N per ha (50 lb N acre(-1)), and soil fertilized at 112.3 kg N per ha (100 lb N acre(-1)). The average NO consumption rates were 7.1x10(-13) g-NO cm(-3) soil, 3.5x10(-11) g-NO cm(-3) soil, and 1.5x10(-10) g-NO cm(-3) soil, respectively. PMID:11916050

Rammon, Desirée A; Peirce, J Jeffrey

2002-01-01

142

Magnetic resonance imaging contrast of iron oxide nanoparticles developed for hyperthermia is dominated by iron content  

PubMed Central

Purpose Magnetic iron oxide nanoparticles (MNPs) are used as contrast agents for magnetic resonance imaging (MRI) and hyperthermia for cancer treatment. The relationship between MRI signal intensity and cellular iron concentration for many new formulations, particularly MNPs having magnetic properties designed for heating in hyperthermia, is lacking. In this study, we examine the correlation between MRI T2 relaxation time and iron content in cancer cells loaded with various MNP formulations. Materials and methods Human prostate carcinoma DU-145 cells were loaded with starch-coated bionised nanoferrite (BNF), iron oxide (Nanomag® D-SPIO), Feridex™, and dextran-coated Johns Hopkins University (JHU) particles at a target concentration of 50 pg Fe/cell using poly-D-lysine transfection reagent. T2-weighted MRI of serial dilutions of these labelled cells was performed at 9.4 T and iron content quantification was performed using inductively coupled plasma mass spectrometry (ICP-MS). Clonogenic assay was used to characterise cytotoxicity. Results No cytotoxicity was observed at twice the target intracellular iron concentration (~100 pg Fe/cell). ICP-MS revealed highest iron uptake efficiency with BNF and JHU particles, followed by Feridex and Nanomag-D-SPIO, respectively. Imaging data showed a linear correlation between increased intracellular iron concentration and decreased T2 times, with no apparent correlation among MNP magnetic properties. Conclusions This study demonstrates that for the range of nanoparticle concentrations internalised by cancer cells the signal intensity of T2-weighted MRI correlates closely with absolute iron concentration associated with the cells. This correlation may benefit applications for cell-based cancer imaging and therapy including nanoparticle-mediated drug delivery and hyperthermia. PMID:24773041

Wabler, Michele; Zhu, Wenlian; Hedayati, Mohammad; Attaluri, Anilchandra; Zhou, Haoming; Mihalic, Jana; Geyh, Alison; DeWeese, Theodore L.; Ivkov, Robert; Artemov, Dmitri

2015-01-01

143

Hydration of calcium oxide surface predicted by reactive force field molecular dynamics.  

PubMed

In this work, we present the parametrization of Ca-O/H interactions within the reactive force field ReaxFF, and its application to study the hydration of calcium oxide surface. The force field has been fitted using density functional theory calculations on gas phase calcium-water clusters, calcium oxide bulk and surface properties, calcium hydroxide, bcc and fcc Ca, and proton transfer reactions in the presence of calcium. Then, the reactive force field has been used to study the hydration of the calcium oxide {001} surface with different water contents. Calcium oxide is used as a catalyzer in many applications such as CO(2) sequestration and biodiesel production, and the degree of surface hydroxylation is a key factor in its catalytic performance. The results show that the water dissociates very fast on CaO {001} bare surfaces without any defect or vacancy. The surface structure is maintained up to a certain amount of water, after which the surface undergoes a structural rearrangement, becoming a disordered calcium hydroxyl layer. This transformation is the most probable reason for the CaO catalytic activity decrease. PMID:22316164

Manzano, Hegoi; Pellenq, Roland J M; Ulm, Franz-Josef; Buehler, Markus J; van Duin, Adri C T

2012-03-01

144

Graphene oxide assisted hydrothermal carbonization of carbon hydrates.  

PubMed

Hydrothermal carbonization (HTC) of biomass such as glucose and cellulose typically produces micrometer-sized carbon spheres that are insulating. Adding a very small amount of Graphene oxide (GO) to glucose (e.g., 1:800 weight ratio) can significantly alter the morphology of its HTC product, resulting in more conductive carbon materials with higher degree of carbonization. At low mass loading level of GO, HTC treatment results in dispersed carbon platelets of tens of nanometers in thickness, while at high mass loading levels, free-standing carbon monoliths are obtained. Control experiments with other carbon materials such as graphite, carbon nanotubes, carbon black, and reduced GO show that only GO has significant effect in promoting HTC conversion, likely due to its good water processability, amphiphilicity, and two-dimensional structure that may help to template the initially carbonized materials. GO offers an additional advantage in that its graphene product can act as an in situ heating element to enable further carbonization of the HTC products very rapidly upon microwave irradiation. Similar effect of GO is also observed for the HTC treatment of cellulose. PMID:24298909

Krishnan, Deepti; Raidongia, Kalyan; Shao, Jiaojing; Huang, Jiaxing

2014-01-28

145

Glycoconjugated chitosan stabilized iron oxide nanoparticles as a multifunctional nanoprobe  

Microsoft Academic Search

Surface modification of iron oxide nanoparticles (IOPs) with functional polymer can be used for the preparation of multifunction nanoprobes. The present study dealt with the preparation of glycoconjugated chitosan (GC) stabilized IOPs (GC-IOPs). GC was prepared by direct coupling of lactobionic acid (LA) on chitosan. GC was subsequently grafted onto the surface of IOPs to enhance colloid stability. X-ray diffraction

So Min Lee; Eun Soo Yoo; Jin Hyun Choi; Han Do Ghim

2009-01-01

146

Iron-Titanium Oxides and Oxygen Fugacities in Volcanic Rocks  

Microsoft Academic Search

It is shown that in silicate liquids the ferric-ferrous equilibrium is controlled by temperature, oxygen fugacity, and the composition of the liquid, particularly its alkali content. Thus, if the iron-titanium oxide minerals that precipitate from a silicate liquid reflect the ferricferrous equilibrium, the oxygen geobarometer of Buddington and Lindsley will have to be calibrated, especially for such volcanics as phonolites

I. S. E. Carmichael; J. Nicholls

1967-01-01

147

The adsorption of aquatic humic substances by iron oxides  

Microsoft Academic Search

The interactions of humic substances from Esthwaite Water with hydrous iron oxides ( -FeOOH, -Fe 2 O 3 , amorphous Fe-gel) have been examined by measuring adsorption isotherms and by microelectrophoresis. In Na + -Cl - -HCO 3 - at I = 0.002 M (medium I) the extent of adsorption decreases with increasing pH. The results are consistent with a

E. Tipping

1981-01-01

148

Discovery of the recoverable high-pressure iron oxide Fe4O5  

E-print Network

Discovery of the recoverable high-pressure iron oxide Fe4O5 Barbara Lavinaa,b,1 , Przemyslaw Derac affecting planetary evolution, life, and technology. Iron oxides have unique electronic properties report the discovery of an iron oxide with for- mula Fe4O5, synthesized at high pressure and temperature

Downs, Robert T.

149

The Effect of Iron Oxide on Dissimilatory Nitrate Reduction to Ammonium (DNRA) in Lignin Cellulose medium  

E-print Network

The Effect of Iron Oxide on Dissimilatory Nitrate Reduction to Ammonium (DNRA) in Lignin Cellulose that may be more harmful than nitrate. In order to reduce ammonium production I proposed to add iron oxide oxidizing bacteria capable of DNRA. It was concluded that the iron addition actually prevented the reduction

Vallino, Joseph J.

150

Accumulation of Metals by Bacteriogenic Iron Oxides in a Subterranean Environment  

E-print Network

Accumulation of Metals by Bacteriogenic Iron Oxides in a Subterranean Environment F. G. FERRIS emission spectroscopy revealed iron oxide contents that varied from 60% to 90% (dry weight basis). Metal decreasing with increasing iron oxide content was evident for each metal, implying that metal uptake

Konhauser, Kurt

151

Detection of low concentrations of ne-grained iron oxides by voltammetry of microparticles  

E-print Network

Detection of low concentrations of ¢ne-grained iron oxides by voltammetry of microparticles I of the samples; concentrations of (anti)ferromagnetic iron(oxy)(hydr)oxides down to V0.1 wt% could be detected. � Abstract Mineralogical discrimination of iron oxides in soils and sediments is not a trivial task, mainly

Utrecht, Universiteit

152

Chromium Substitution Effect on the Magnetic Structure of Iron Oxides  

NASA Astrophysics Data System (ADS)

The local magnetic and electronic structures of chromium substituted iron oxide polycrystalline samples are investigated via Fe L-edge x-ray absorption near-edge structural and magnetic circular dichroism measurements. A strong dependence of atomic magnetic levels on the applied external magnetic field is observed. The magnetic behavior of Cr-doped iron oxides are determined to be dominantly governed by the d—d hybridization between Fe and Cr valence levels. In addition, the formation of CrO2 and Cr2O3 chromium oxide clusters in the sample are observed to determine the magnetic ordering, i.e. anti-ferromagnetic or ferromagnetic with the changing external magnetic fields. The results highly agree with the previous studies.

Osman Murat, Ozkendir

2012-05-01

153

Selective removal of phosphate from wastewater using hydrated metal oxides dispersed within anionic exchange media.  

PubMed

Hydrated ferric oxide (HFeO), hydrated zirconium oxide (HZrO) and hydrated copper oxide (HCuO) were immobilized within a microporous anion exchange resin (IRA-400), forming hybrid media for enhanced phosphate removal from aqueous systems. Empirical data from batch kinetic trials fitted the pseudo second order mechanism for chemical adsorption and each media was rate limited by intraparticle diffusion overall. These models were also used to predict the adsorption rate constants and the equilibrium adsorption capacities, which ranged from 26.51 to 30.44mgPg(-1), and from 24.15 to 27.90mgPg(-1) of media for the calculated and experimental capacities, respectively. The phosphate adsorption behavior by the hybrid materials fit both the Langmuir and Freundlich adsorption isotherms (R(2)>0.94), and the maximum adsorption capacities were 111.1mgPg(-1) for HFeO, 91.74mgPg(-1) for HZrO and 74.07mgPg(-1) for HCuO. The effect of competing ions such as sulfate reduced these capacities to 18.52mgPg(-1) for HFeO and 18.97mgPg(-1) for HZrO. Despite this decrease, HFeO was capable of reducing the phosphate in a real wastewater matrix by 83%, and the HZrO media was able to reduce it by 86%, suggesting that such hybrid media have the potential for application at full scale. PMID:24630462

Acelas, Nancy Y; Martin, Benjamin D; López, Diana; Jefferson, Bruce

2015-01-01

154

Low-temperature hydration, oxidation and hydrogen production from Oman peridotite  

NASA Astrophysics Data System (ADS)

Peridotite in the shallow subsurface undergoes hydration and oxidation (serpentinization) during reactions with percolating fluids, generating hydrogen gas and releasing magnesium, iron, and calcium into solution. In the presence of fluids enriched in dissolved carbon dioxide, extensive precipitation of carbonate minerals occurs. This reaction has large-scale implications for mitigating climate change by providing a stable, geological carbon repository. The Samail Ophiolite in Oman contains large quantities of ultramafic rocks that are currently undergoing serpentinization at low temperatures (30°C) and forming carbonate minerals. The production of hydrogen gas provides an electron donor for subsurface chemolithoautotrophic life which can contribute to carbon cycling in the subsurface as microorganisms utilize carbon dioxide as an inorganic carbon source. Serpentinization reactions require the oxidation of Fe (II) to Fe (III) to reduce water to H2, but the mechanisms of hydrogen generation in low-temperature systems is poorly characterized. To address this question, we conducted low temperature (100°C) water-rock reactions with Oman peridotite, measured H2 and characterized the speciation of Fe-bearing minerals before and after water-rock interaction using micro-X-ray Absorption Near Edge Structure (?XANES) spectra obtained from Stanford Synchrotron Radiation Lightsource. The experimental water-rock reactions produce H2 at a pH of 9, which corresponds with observations of ultrabasic springs in the Samail ophiolite and the presence of H2 in these spring waters. Significant hydrogen production occurs for two and a half months of reaction, peaking at 400 nmol/gram of reacted peridotite and then steadily decreases with time. These maximum values of hydrogen production from Oman peridotite are greater than observed by our laboratory and others during aqueous alteration of San Carlos peridotite and isolated pyroxenes and olivines (e.g. Mayhew et al. 2013 [1]). The products of low-temperature serpentinization, as determined by least squares fits of model spectra to sample ?XANES spectra, include serpentine minerals, altered olivines and Fe(III) minerals. X-ray fluorescence (?XRF) maps of the distribution of Fe-bearing phases reveal extensive alteration of pyroxenes to a mixture of Fe(II) and Fe(III)-bearing phases during the 100°C water-rock interactions, while olivine grains are only incipiently altered along fracture networks, suggesting an important role for pyroxenes in low temperature H2-generating reactions. The serpentinization reactions in the Oman peridotite are producing significant levels of hydrogen at a low temperature within the habitability limit for life, suggesting Oman provides a subsurface niche for hydrogen-utilizing microorganisms. The microbiology of the Oman subsurface is important to consider when investigating carbonation reactions aimed for carbon capture and sequestration because microbial life can affect carbon availability, and the injection of CO2 into the aquifer may significantly alter the ecosystem. [1] Mayhew et al. 2013. Nature Geoscience

Miller, H. M.; Mayhew, L.; Templeton, A. S.

2013-12-01

155

In vivo biodistribution of iron oxide nanoparticles: an overview  

NASA Astrophysics Data System (ADS)

Iron oxide nanoparticles present a promising alternative to conventional energy deposition-based tissue therapies. The success of such nanoparticles as a therapeutic for diseases like cancer, however, depends heavily on the particles' ability to localize to tumor tissue as well as provide minimal toxicity to surrounding tissues and key organs such as those involved in the reticuloendothelial system (RES). We present here the results of a long term clearance study where mice injected intravenously with 2 mg Fe of 100 nm dextran-coated iron oxide nanoparticles were sacrificed at 14 and 580 days post injection. Histological analysis showed accumulation of the nanoparticles in some RES organs by the 14 day time point and clearance of the nanoparticles by the 580 day time point with no obvious toxicity to organs. An additional study reported herein employs 20 nm and 110 nm starch-coated iron oxide nanoparticles at 80 mg Fe/kg mouse in a size/biodistribution study with endpoints at 4, 24 and 72 hours. Preliminary results show nanoparticle accumulation in the liver and spleen with some elevated iron accumulation in tumoral tissues with differences between the 20 nm and the 110 nm nanoparticle depositions.

Tate, Jennifer A.; Petryk, Alicia A.; Giustini, Andrew J.; Hoopes, P. Jack

2011-03-01

156

Study of nanocomposites based on iron oxides and pectin  

NASA Astrophysics Data System (ADS)

Mössbauer and X-ray diffraction study of nanocomposites based on iron oxides and pectin (PC) was carried out involving magnetization measurements. The concentrations of PC in nanocomposites varied from 0 to 10%. Mössbauer investigations of nanocomposites were carried out in the temperature range from 5 to 300 K. Many-state superparamagnetic relaxation model was used for spectra fitting. The magnetization, M(T,H), was measured in the temperature interval of 80-300 K and magnetic field up to 10 kOe. Formation of the "iron-polymer" interface was not observed. Particle sizes were estimated using the Mössbauer and X-ray powder diffraction data.

Chistyakova, Nataliya I.; Shapkin, Alexey A.; Sirazhdinov, Ruslan R.; Gubaidulina, Tatiana V.; Kiseleva, Tatiana Yu.; Kazakov, Alexander P.; Rusakov, Vyacheslav S.

2014-10-01

157

Enzymes of respiratory iron oxidation. Progress report, March 1990--November 1991  

SciTech Connect

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

Blake, R. II

1991-12-31

158

Niobian iron oxides as heterogeneous Fenton catalysts for environmental remediation  

NASA Astrophysics Data System (ADS)

Heterogeneous Fenton or Fenton-like reagents consist of a mixture of an iron-containing solid matrix and a liquid medium with H2O2. The Fenton system is based on the reaction between Fe2 + and H2O2 to produce highly reactive intermediate hydroxyl radicals ( • OH), which are able to oxidize organic contaminants, whereas the Fenton-like reaction is based on the reaction between Fe3 + and H2O2. These heterogeneous systems offer several advantages over their homogeneous counterparts, such as no sludge formation, operation at near-neutral pH and the possibility of recycling the iron promoter. Some doping transition cations in the iron oxide structure are believed to enhance the catalytic efficiency for the oxidation of organic substrates in water. In this work, goethites synthesized in presence of niobium served as precursors for the preparation of magnetites (niobian magnetites) via chemical reduction with hydrogen at 400°C. These materials were used as Fenton-like catalysts. Both groups of (Nb, Fe)-oxide samples were characterized by 57Fe Mössbauer spectroscopy at 298 K. The results show that increasing niobium contents raise the catalytic potential for decomposition of methylene blue, which was, in this work, used as a model molecule for organic substrates in water.

Oliveira, Diana Q. L.; Oliveira, Luiz C. A.; Murad, Enver; Fabris, José D.; Silva, Adilson C.; de Menezes, Lucas Morais

2010-01-01

159

Oxidative effect of several intravenous iron complexes in the rat.  

PubMed

The objective of this study was to compare the oxidative stress induced in rat internal organs by the administration of the following clinically used intravenous (IV) iron (Fe) containing compounds: iron sucrose (IS), iron dextran (ID), ferric carboxymaltose and ferumoxytol. Groups of six adult rats received 1 mg/kg of each compound weekly for 5 doses. Seven days following the last dose, animals were euthanized and tissue samples of heart, lung, liver, and kidney were obtained, washed in warmed saline and frozen under liquid nitrogen and stored at -80 °C for analysis for nitrotyrosine (NT) and dinitro phenyl (DNP) as markers of oxidative stress. All tissues showed a similar pattern of oxidative stress. All Fe products stimulated an increase in the tissue concentration of both NT and DNP. In general, DNP was stimulated significantly less than NT except for IS. DNP was stimulated to an equal degree except for ID where NT was significantly higher than the NT concentrations in all other Fe compounds. ID produced over 10-fold the concentration of NT than any other Fe. IV Fe compounds present a risk of oxidative stress to a variety of internal organs. However, we found that IS was the least damaging and ID was the worst. PMID:23681275

Bailie, George R; Schuler, Catherine; Leggett, Robert E; Li, Hsin; Li, Hsin-Dat; Patadia, Hiten; Levin, Robert

2013-06-01

160

Intratumoral iron oxide nanoparticle hyperthermia and radiation cancer treatment  

NASA Astrophysics Data System (ADS)

The potential synergism and benefit of combined hyperthermia and radiation for cancer treatment is well established, but has yet to be optimized clinically. Specifically, the delivery of heat via external arrays /applicators or interstitial antennas has not demonstrated the spatial precision or specificity necessary to achieve appropriate a highly positive therapeutic ratio. Recently, antibody directed and possibly even non-antibody directed iron oxide nanoparticle hyperthermia has shown significant promise as a tumor treatment modality. Our studies are designed to determine the effects (safety and efficacy) of iron oxide nanoparticle hyperthermia and external beam radiation in a murine breast cancer model. Methods: MTG-B murine breast cancer cells (1 x 106) were implanted subcutaneous in 7 week-old female C3H/HeJ mice and grown to a treatment size of 150 mm3 +/- 50 mm3. Tumors were then injected locally with iron oxide nanoparticles and heated via an alternating magnetic field (AMF) generator operated at approximately 160 kHz and 400 - 550 Oe. Tumor growth was monitored daily using standard 3-D caliper measurement technique and formula. specific Mouse tumors were heated using a cooled, 36 mm diameter square copper tube induction coil which provided optimal heating in a 1 cm wide region in the center of the coil. Double dextran coated 80 nm iron oxide nanoparticles (Triton Biosystems) were used in all studies. Intra-tumor, peri-tumor and rectal (core body) temperatures were continually measured throughout the treatment period. Results: Preliminary in vivo nanoparticle-AMF hyperthermia (167 KHz and 400 or 550 Oe) studies demonstrated dose responsive cytotoxicity which enhanced the effects of external beam radiation. AMF associated eddy currents resulted in nonspecific temperature increases in exposed tissues which did not contain nanoparticles, however these effects were minor and not injurious to the mice. These studies also suggest that iron oxide nanoparticle hyperthermia is more effective than non-nanoparticle tumor heating techniques when similar thermal doses are applied. Initial electron and light microscopy studies of iron oxide nanoparticle and AMF exposed tumor cells show a rapid uptake of particles and acute cytotoxicity following AMF exposure.

Hoopes, P. J.; Strawbridge, R. R.; Gibson, U. J.; Zeng, Q.; Pierce, Z. E.; Savellano, M.; Tate, J. A.; Ogden, J. A.; Baker, I.; Ivkov, R.; Foreman, A. R.

2007-02-01

161

Treatment with iron oxide nanoparticles induces ferritin synthesis but not oxidative stress in oligodendroglial cells.  

PubMed

Magnetic iron oxide nanoparticles (IONPs) have been used for a variety of neurobiological applications, although little is yet known as to the fate of such particles in brain cells. To address these questions, we have exposed oligodendroglial OLN-93 cells to dimercaptosuccinate-coated IONPs. Treatment of the cells strongly increased the specific cellular iron content proportional to the IONP concentrations applied (0-1000 ?M total iron as IONPs) up to 300-fold, but did not cause any acute cytotoxicity or induce oxidative stress. To investigate the potential of OLN-93 cells to liberate iron from the accumulated IONPs, we have studied the upregulation of the iron storage protein ferritin and the cell proliferation as cellular processes that depend on the availability of low-molecular-weight iron. The presence of IONPs caused a concentration-dependent increase in the amount of cellular ferritin and partially bypassed the inhibition of cell proliferation by the iron chelator deferoxamine. These data demonstrate that viable OLN-93 cells efficiently take up IONPs and suggest that these cells are able to use iron liberated from accumulated IONPs for their metabolism. PMID:21763792

Hohnholt, Michaela C; Geppert, Mark; Dringen, Ralf

2011-11-01

162

Wear resistance of iron oxide thin films  

Microsoft Academic Search

Magnetite films (Fe3O4) were reactively sputtered onto (100) silicon substrates in an Ar+O2 gas environment from a target containing Fe and 0.75 at. % Os. The films were then oxidized in air to form ?-Fe2O3. The wear resistance of the films was evaluated using an oscillatory wear tester and a contact start\\/stop tester with IBM 3380 type of sliders. Magnetite

Mao-Min Chen; Judy Lin; Tsai-Wei Wu; Gilbert Castillo

1988-01-01

163

Iron-mediated anaerobic oxidation of methane in brackish coastal sediments.  

PubMed

Methane is a powerful greenhouse gas and its biological conversion in marine sediments, largely controlled by anaerobic oxidation of methane (AOM), is a crucial part of the global carbon cycle. However, little is known about the role of iron oxides as an oxidant for AOM. Here we provide the first field evidence for iron-dependent AOM in brackish coastal surface sediments and show that methane produced in Bothnian Sea sediments is oxidized in distinct zones of iron- and sulfate-dependent AOM. At our study site, anthropogenic eutrophication over recent decades has led to an upward migration of the sulfate/methane transition zone in the sediment. Abundant iron oxides and high dissolved ferrous iron indicate iron reduction in the methanogenic sediments below the newly established sulfate/methane transition. Laboratory incubation studies of these sediments strongly suggest that the in situ microbial community is capable of linking methane oxidation to iron oxide reduction. Eutrophication of coastal environments may therefore create geochemical conditions favorable for iron-mediated AOM and thus increase the relevance of iron-dependent methane oxidation in the future. Besides its role in mitigating methane emissions, iron-dependent AOM strongly impacts sedimentary iron cycling and related biogeochemical processes through the reduction of large quantities of iron oxides. PMID:25412274

Egger, Matthias; Rasigraf, Olivia; Sapart, Célia J; Jilbert, Tom; Jetten, Mike S M; Röckmann, Thomas; van der Veen, Carina; Bând?, Narcisa; Kartal, Boran; Ettwig, Katharina F; Slomp, Caroline P

2015-01-01

164

Reflection spectra and magnetochemistry of iron oxides and natural surfaces  

NASA Technical Reports Server (NTRS)

The magnetic properties and spectral characteristics of iron oxides are distinctive. Diagnostic features in reflectance spectra (0.5 to 2.4 micron) for alpha Fe2O3, gamma Fe2O3, and FeOOH include location of Fe3(+) absorption features, intensity ratios at various wavelengths, and the curve shape between 1.2 micron and 2.4 micron. The reflection spectrum of natural rock surfaces are seldom those of the bulk rock because of weathering effects. Coatings are found to be dominated by iron oxides and clay. A simple macroscopic model of rock spectra (based on concepts of stains and coatings) is considered adequate for interpretation of LANDSAT data. The magnetic properties of materials associated with specific spectral types and systematic changes in both spectra and magnetic properties are considered.

Wasilewski, P.

1978-01-01

165

Iron aluminide alloy container for solid oxide fuel cells  

DOEpatents

A container for fuel cells is made from an iron aluminide alloy. The container alloy preferably includes from about 13 to about 22 weight percent Al, from about 2 to about 8 weight percent Cr, from about 0.1 to about 4 weight percent M selected from Zr and Hf, from about 0.005 to about 0.5 weight percent B or from about 0.001 to about 1 weight percent C, and the balance Fe and incidental impurities. The iron aluminide container alloy is extremely resistant to corrosion and metal loss when exposed to dual reducing and oxidizing atmospheres at elevated temperatures. The alloy is particularly useful for containment vessels for solid oxide fuel cells, as a replacement for stainless steel alloys which are currently used.

Judkins, Roddie Reagan (Knoxville, TN); Singh, Prabhakar (Export, PA); Sikka, Vinod Kumar (Oak Ridge, TN)

2000-01-01

166

Characterization of iron oxide-dextran magnetic nanoparticle suspensions  

NASA Astrophysics Data System (ADS)

Magnetic nanoparticles, with structures from core-shell to nanocrystallites in a matrix, are candidates for use in biomedical applications. "Superparamagnetic iron oxide" (SPIO) nanoparticles are nanocrystallites of iron oxide in a dextran matrix, with sizes between 20nm and 250nm. Dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and hysteresis measurements were used for structural and magnetic characterization. Additionally, cryoquench-TEM was performed, allowing direct imaging without false aggregation from drying. The DLS-determined size of the particles is 250nm, but cryoquench-TEM yields a smaller size of 150nm. In addition, the particles are relatively well-dispersed, but dimers and trimers are observed. This corresponds with the evidence of weak interactions in magnetic hysteresis measurements. Further magnetic characterization will provide information on how the magnetic properties of these SPIO particles correlate with their size and structure.

Shih, J.; Bai, R.; Chiou, W.; Briber, R. M.; Borchers, J. A.; Dennis, C. L.; Gruettner, C.

2011-03-01

167

Potential toxicity of superparamagnetic iron oxide nanoparticles (SPION)  

PubMed Central

Superparamagnetic iron oxide nanoparticles (SPION) are being widely used for various biomedical applications, for example, magnetic resonance imaging, targeted delivery of drugs or genes, and in hyperthermia. Although, the potential benefits of SPION are considerable, there is a distinct need to identify any potential cellular damage associated with these nanoparticles. Besides focussing on cytotoxicity, the most commonly used determinant of toxicity as a result of exposure to SPION, this review also mentions the importance of studying the subtle cellular alterations in the form of DNA damage and oxidative stress. We review current studies and discuss how SPION, with or without different surface coating, may cause cellular perturbations including modulation of actin cytoskeleton, alteration in gene expression profiles, disturbance in iron homeostasis and altered cellular responses such as activation of signalling pathways and impairment of cell cycle regulation. The importance of protein-SPION interaction and various safety considerations relating to SPION exposure are also addressed. PMID:22110864

Singh, Neenu; Jenkins, Gareth J.S.; Asadi, Romisa; Doak, Shareen H.

2010-01-01

168

Nanovectors for anticancer agents based on superparamagnetic iron oxide nanoparticles  

PubMed Central

During the last decade, the application of nanotechnologies for anticancer drug delivery has been extensively explored, hoping to improve the efficacy and to reduce side effects of chemotherapy. The present review is dedicated to a certain kind of anticancer drug nanovectors developed to target tumors with the help of an external magnetic field. More particularly, this work treats anticancer drug nanoformulations based on superparamagnetic iron oxide nanoparticles coated with biocompatible polymers. The major purpose is to focus on the specific requirements and technological difficulties related to controlled delivery of antitumoral agents. We attempt to state the problem and its possible perspectives by considering the three major constituents of the magnetic therapeutic vectors: iron oxide nanoparticles, polymeric coating and anticancer drug. PMID:18203422

Douziech-Eyrolles, Laurence; Marchais, Hervé; Hervé, Katel; Munnier, Emilie; Soucé, Martin; Linassier, Claude; Dubois, Pierre; Chourpa, Igor

2007-01-01

169

Thermodynamics of Uranyl Minerals: Enthalpies of Formation of Uranyl Oxide Hydrates  

SciTech Connect

The enthalpies of formation of seven uranyl oxide hydrate phases and one uranate have been determined using high-temperature oxide melt solution calorimetry: [(UO{sub 2}){sub 4}O(OH){sub 6}](H{sub 2}O){sub 5}, metaschoepite; {beta}-UO{sub 2}(OH){sub 2}; CaUO{sub 4}; Ca(UO{sub 2}){sub 6}O{sub 4}(OH){sub 6}(H{sub 2}O){sub 8}, becquerelite; Ca(UO{sub 2}){sub 4}O{sub 3}(OH){sub 4}(H{sub 2}O){sub 2}; Na(UO{sub 2})O(OH), clarkeite; Na{sub 2}(UO{sub 2}){sub 6}O{sub 4}(OH){sub 6}(H{sub 2}O){sub 7}, the sodium analogue of compreignacite and Pb{sub 3}(UO{sub 2}){sub 8}O{sub 8}(OH){sub 6}(H{sub 2}O){sub 2}, curite. The enthalpy of formation from the binary oxides, {Delta}H{sub f-ox}, at 298 K was calculated for each compound from the respective drop solution enthalpy, {Delta}H{sub ds}. The standard enthalpies of formation from the elements, {Delta}H{sub f}{sup o}, at 298 K are -1791.0 {+-} 3.2, -1536.2 {+-} 2.8, -2002.0 {+-} 3.2, -11389.2 {+-} 13.5, -6653.1 {+-} 13.8, -1724.7 {+-} 5.1, -10936.4 {+-} 14.5 and -13163.2 {+-} 34.4 kJ mol{sup -1}, respectively. These values are useful in exploring the stability of uranyl oxide hydrates in auxiliary chemical systems, such as those expected in U-contaminated environments.

K. Kubatko; K. Helean; A. Navrotsky; P.C. Burns

2005-05-11

170

The kinetics of reduction of iron oxides at moderate temperatures  

Microsoft Academic Search

The rates of reduction of wustite with hydrogen were measured in the temperature range 511 to 690 K. The wustite specimens\\u000a were prepared by oxidizing thin iron foils, 50?m thick. These were reduced in a Cahn electrobalance under isothermal conditions\\u000a and the weight loss sustained was continuously monitored. The effect of the phase transformation of wustite on the reduction\\u000a kinetics

S. K. El-Rahaiby; Y. K. Rao

1979-01-01

171

Iron oxide-copper-gold deposits: an Andean view  

Microsoft Academic Search

Iron oxide-copper-gold (IOCG) deposits, defined primarily by their elevated magnetite and\\/or hematite contents, constitute a broad, ill-defined clan related to a variety of tectono-magmatic settings. The youngest and, therefore, most readily understandable IOCG belt is located in the Coastal Cordillera of northern Chile and southern Peru, where it is part of a volcano-plutonic arc of Jurassic through Early Cretaceous age.

Richard H. Sillitoe

2003-01-01

172

Cation Exchange in Kaolinite-Iron Oxide Systems  

Microsoft Academic Search

Kaolinite, to which iron oxides had been added by heating with FoC13 solution, was studied with regard to its cation exchange capacity. It was observed that net cations held (cations less anions) varied directly with pH. Cations and anions are removed in equivalent amounts when the clays arc washed with water, l%cmoval of exchangeable cations proceeds as the last anions

Grant W. Thomas; ALLEN R. SWOBODA

1962-01-01

173

Iron inhibits the nitric oxide synthesis elicited by asbestos in murine macrophages  

Microsoft Academic Search

Crocidolite fibers stimulated nitric oxide synthase (NOS) activity and expression in glial and alveolar murine macrophages: this effect was inhibited by iron supplementation and enhanced by iron chelation. We suggest that in these cells crocidolite stimulates NOS expression by decreasing the iron bioavailability and activating an iron-sensitive transcription factor.

Elisabetta Aldieri; Dario Ghigo; Maura Tomatis; Laura Prandi; Ivana Fenoglio; Costanzo Costamagna; Gianpiero Pescarmona; Amalia Bosia; Bice Fubini

2001-01-01

174

Iron-oxidizing microbial ecosystems thrived in late Paleoproterozoic redox-stratified oceans  

E-print Network

Iron-oxidizing microbial ecosystems thrived in late Paleoproterozoic redox-stratified oceans Noah Keywords: iron-bacteria iron-formations Fe-isotopes rare earth elements Paleoproterozoic stromatolites We conducted a geochemical and petrographic study of the 1.89billion year old Gunflint and Biwabik iron

Bekker, Andrey

175

Iron inhibits the nitric oxide synthesis elicited by asbestos in murine macrophages.  

PubMed

Crocidolite fibers stimulated nitric oxide synthase (NOS) activity and expression in glial and alveolar murine macrophages: this effect was inhibited by iron supplementation and enhanced by iron chelation. We suggest that in these cells crocidolite stimulates NOS expression by decreasing the iron bioavailability and activating an iron-sensitive transcription factor. PMID:11461780

Aldieri, E; Ghigo, D; Tomatis, M; Prandi, L; Fenoglio, I; Costamagna, C; Pescarmona, G; Bosia, A; Fubini, B

2001-08-01

176

Aging of Iron (Hydr)oxides by Heat Treatment and Effects on Heavy  

E-print Network

Aging of Iron (Hydr)oxides by Heat Treatment and Effects on Heavy Metal Binding M E T T E A . S Ã? R and Environmental Engineering, University of Washington, Seattle, Washington 98195 Amorphous iron (hydr generated in waste incineration. In this study, iron oxides containing heavy metals (e.g., Pb, Hg, Cr

Frenkel, Anatoly

177

A photonic crystal biosensor assay for ferritin utilizing iron-oxide nanoparticles  

E-print Network

biosensor as an immunodiagnostic platform for detection of serum ferritin, a biomarker for iron deficiency with iron-oxide nanoparticles (FpAb) assays were detected using the Biomolecular Interaction Detection (BINDA photonic crystal biosensor assay for ferritin utilizing iron-oxide nanoparticles Ross D. Peterson

Cunningham, Brian

178

Investigation of magnetically controlled water intake behavior of Iron Oxide Impregnated Superparamagnetic Casein Nanoparticles (IOICNPs).  

PubMed

Iron oxide impregnated casein nanoparticles (IOICNPs) were prepared by in-situ precipitation of iron oxide within the casin matrix. The resulting iron oxide impregnated casein nanoparticles (IOICNPs) were characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Vibrating sample magnetometer (VSM) and Raman spectroscopy. The FTIR analysis confirmed the impregnation of iron oxide into the casein matrix whereas XPS analysis indicated for complete oxidation of iron (II) to iron(III) as evident from the presence of the observed representative peaks of iron oxide. The nanoparticles were allowed to swell in phosphate buffer saline (PBS) and the influence of factors such as chemical composition of nanoparticles, pH and temperature of the swelling bath, and applied magnetic field was investigated on the water intake capacity of the nanoparticles. The prepared nanoparticles showed potential to function as a nanocarrier for possible applications in magnetically targeted delivery of anticancer drugs. PMID:25277602

Singh, Anamika; Bajpai, Jaya; Bajpai, Anil

2014-10-01

179

Iron requirement for Mn(II) oxidation by Leptothrix discophora SS-1.  

PubMed

A common form of biocatalysis of Mn(II) oxidation results in the formation of biogenic Mn(III, IV) oxides and is a key reaction in the geochemical cycling of Mn. In this study, we grew the model Mn(II)-oxidizing bacterium Leptothrix discophora SS-1 in media with limited iron (0.1 microM iron/5.8 mM pyruvate) and sufficient iron (0.2 microM iron/5.8 mM pyruvate). The influence of iron on the rate of extracellular Mn(II) oxidation was evaluated. Cultures in which cell growth was limited by iron exhibited reduced abilities to oxidize Mn(II) compared to cultures in medium with sufficient iron. While the extracellular Mn(II)-oxidizing factor (MOF) is thought to be a putative multicopper oxidase, Mn(II) oxidation in the presence of zero added Cu(II) was detected and the decrease in the observed Mn(II) oxidation rate in iron-limited cultures was not relieved when the medium was supplemented with Cu(II). The decline of Mn(II) oxidation under iron-limited conditions was not accompanied by siderophore production and is unlikely to be an artifact of siderophore complex formation with Mn(III). The temporal variations in mofA gene transcript levels under conditions of limited and abundant iron were similar, indicating that iron limitation did not interfere with the transcription of the mofA gene. Our quantitative PCR results provide a step forward in understanding the regulation of Mn(II) oxidation. The mechanistic role of iron in Mn(II) oxidation is uncertain; the data are consistent with a direct requirement for iron as a component of the MOF or an indirect effect of iron resulting from the limitation of one of many cellular functions requiring iron. PMID:19114505

El Gheriany, Iman A; Bocioaga, Daniela; Hay, Anthony G; Ghiorse, William C; Shuler, Michael L; Lion, Leonard W

2009-03-01

180

Unification of catalytic water oxidation and oxygen reduction reactions: amorphous beat crystalline cobalt iron oxides.  

PubMed

Catalytic water splitting to hydrogen and oxygen is considered as one of the convenient routes for the sustainable energy conversion. Bifunctional catalysts for the electrocatalytic oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are pivotal for the energy conversion and storage, and alternatively, the photochemical water oxidation in biomimetic fashion is also considered as the most useful way to convert solar energy into chemical energy. Here we present a facile solvothermal route to control the synthesis of amorphous and crystalline cobalt iron oxides by controlling the crystallinity of the materials with changing solvent and reaction time and further utilize these materials as multifunctional catalysts for the unification of photochemical and electrochemical water oxidation as well as for the oxygen reduction reaction. Notably, the amorphous cobalt iron oxide produces superior catalytic activity over the crystalline one under photochemical and electrochemical water oxidation and oxygen reduction conditions. PMID:25469760

Indra, Arindam; Menezes, Prashanth W; Sahraie, Nastaran Ranjbar; Bergmann, Arno; Das, Chittaranjan; Tallarida, Massimo; Schmeißer, Dieter; Strasser, Peter; Driess, Matthias

2014-12-17

181

Evidence for an oxygen evolving iron-oxo-cerium intermediate in iron-catalysed water oxidation.  

PubMed

The non-haem iron complex ?-[Fe(II)(CF3SO3)2(mcp)] (mcp=(N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)-1,2-cis-diaminocyclohexane) reacts with Ce(IV) to oxidize water to O2, representing an iron-based functional model for the oxygen evolving complex of photosystem II. Here we trap an intermediate, characterized by cryospray ionization high resolution mass spectrometry and resonance Raman spectroscopy, and formulated as [(mcp)Fe(IV)(O)(?-O)Ce(IV)(NO3)3](+), the first example of a well-characterized inner-sphere complex to be formed in cerium(IV)-mediated water oxidation. The identification of this reactive Fe(IV)-O-Ce(IV) adduct may open new pathways to validate mechanistic notions of an analogous Mn(V)-O-Ca(II) unit in the oxygen evolving complex that is responsible for carrying out the key O-O bond forming step. PMID:25609387

Codolà, Zoel; Gómez, Laura; Kleespies, Scott T; Que, Lawrence; Costas, Miquel; Lloret-Fillol, Julio

2015-01-01

182

Surface engineering of iron oxide nanoparticles for targeted cancer therapy  

PubMed Central

Conspectus Nanotechnology provides a flexible platform for the development of effective therapeutic nanomaterials that can interact specifically with a target in a biological system and provoke a desired biological response. Of the nanomaterials studied, iron oxide nanoparticles have emerged as one of top candidates for cancer therapy due to their intrinsic superparamagnetism that enables no-invasive magnetic resonance imaging (MRI) and biodegradability favorable for in vivo application. A therapeutic superparamagnetic iron oxide nanoparticle (SPION) typically consists of three primary components: an iron oxide nanoparticle core that serves as both a carrier for therapeutics and contrast agent for MRI, a coating on the iron oxide nanoparticle that promotes favorable interactions between the SPION and biological system, and a therapeutic payload that performs designated function in vivo. Often, a targeting ligand is also included in the design that recognizes the receptors over-expressed on cancer cells. The body is a highly complex system that imposes multiple physiological and cellular barriers to foreign objects. Thus, the success of a therapeutic SPION largely relies on the proper design of the iron oxide core to ensure MRI detectability and more critically, the coating to render the ability to bypass these barriers. Strategies to bypass the physiological barriers such as liver, kidneys, and spleen, involve tuning the overall size and surface chemistry of the SPION to maximize blood half-life and facilitate the navigation in the body. Strategies to bypass cellular barriers include the use of targeting agents to maximize uptake of the SPION by cancer cells, and employing materials that promote desired intracellular trafficking and enable controlled drug release. The payload can be genes, proteins, chemotherapy drugs, or a combination of them. Each therapeutic requires a specific coating design to maximize the loading and achieve effective delivery and release. In this Account, we discuss the primary design parameters in developing therapeutic SPIONs with a focus on surface coating design to overcome the barriers imposed by the body’s defense system and provide examples of how these design parameters have been implemented to produce therapeutic SPIONs for specific therapeutic applications. Although there are still challenges to be addressed, SPIONs show great promise in successful diagnosis and treatment of the most devastating cancers. Once critical design parameters have been optimized, these nanoparticles, combined with imaging modalities, can serve as a truly multi-functional theranostic agent that not only performs a therapeutic function, but provides instant treatment feedback for the physician to adjust the treatment plan. PMID:21528865

Kievit, Forrest M.; Zhang, Miqin

2011-01-01

183

Evaluation of Characterization Techniques for Iron Pipe Corrosion Products and Iron Oxide Thin Films  

SciTech Connect

A common problem faced by drinking water studies is that of properly characterizing the corrosion products (CP) in iron pipescor synthetic Fe (hydr)oxides used to simulate the iron pipe used in municipal drinking-water systems. The present work compares the relative applicability of a suite of imaging and analytical techniques for the characterization of CPs and synthetic Fe oxide thin films and provide an overview of the type of data that each instrument can provide as well as their limitations to help researchers and consultants choose the best technique for a given task. Crushed CP from a water distribution system and synthetic Fe oxide thin films formed on glass surfaces were chosen as test samples for this evaluation. The CP and synthetic Fe oxide thin films were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray powder diffractometry (XRD), grazing incident diffractometry (GID), transmission electron microscopy (TEM), selected area electron diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared, Mössbauer spectroscopy, Brunauer-Emmett-Teller N2 adsorption and Fe concentration was determined by the ferrozine method. XRD and GID were found to be the most suitable techniques for identification of the mineralogical composition of CP and synthetic Fe oxide thin films, respectively. AFM and a combined ToF-SIMS-AFM approach proved excellent for roughness and depth profiling analysis of synthetic Fe oxide thin films, respectively. Corrosion products were difficult to study by AFM due to their surface roughness, while synthetic Fe oxide thin films resisted most spectroscopic methods due to their limited thickness (118 nm). XPS analysis is not recommended for mixtures of Fe (hydr)oxides due to their spectral similarities. SEM and TEM provided great detail on mineralogical morphology.

Borch, Thomas; Camper, Anne K.; Biederman, Joel A.; Butterfield, Phillip; Gerlach, Robin; Amonette, James E.

2008-10-01

184

Iron isotope fractionation during photo-oxidation of aqueous ferrous iron  

NASA Astrophysics Data System (ADS)

The classic interpretation of banded iron formations (BIFs) presumes the presence of dissolved O2 in the surface ocean to oxidize ferrous Fe. However, at least two alternative oxidation mechanisms are possible: UV photo-oxidation; and the activity of anaerobic Fe(II)-oxidizing photosynthetic bacteria. We are investigating Fe isotope fractionation as a means of differentiating amongst these mechanisms. Photo-oxidation has been examined at pH ~ 3 and 41°C in the absence of ligands other than H2O, OH-, and Cl- using UVA (316-400 nm) and UVC (200-280 nm) light sources. In these experiments, ferrous Fe was oxidized and precipitated as ferric oxyhydroxide. We find that isotopically heavy Fe was preferentially removed from solution. The fractionation factor (?) for the overall reaction is ~ 1.0025. This value is comparable to the ? between Fe2+ and Fe3+ hexaquo complexes, but larger than the effect seen during the overall process of ferrous Fe oxidation and precipitation at near-neutral pH. The magnitude of isotope fractionation is likely to change at higher pH for two reasons. First, ferric oxyhydroxide precipitation, which may impart a kinetic isotope effect, is faster at higher pH. Second, the major UV-absorbing ferrous species in the ocean is the ferrous hydroxide ion [Fe(OH)+], the concentration of which is strongly pH dependent. Photo-oxidation experiments at realistic seawater pH are under current investigation.

Staton, S.; Amskold, L.; Gordon, G.; Anbar, A.; Konhauser, K.

2006-05-01

185

Abstract No. pan0505 Sorption of Heavy Metal Contaminants onto Hydrated Ferric Oxides: Mechanistic Modeling using X-ray  

E-print Network

Abstract No. pan0505 Sorption of Heavy Metal Contaminants onto Hydrated Ferric Oxides: Mechanistic the fate of heavy metal contaminants, such as lead, zinc, and nickel in soils and aquatic environments. Hence, to understand the mobility and bioavailability of these metal contaminants, these sorption

Sparks, Donald L.

186

Formation of the first oxidized iron in the solar system  

NASA Astrophysics Data System (ADS)

Abstract-For fayalite formation times of several thousand years, and systems enriched in water by a factor of ten relative to solar composition, 1 ?m radius olivine grains could reach 2 mole% fayalite and 0.1 ?m grains 5 mole% by nebular condensation, well short of the values appropriate for precursors of most chondrules and the values found in the matrices of unequilibrated ordinary chondrites. Even 10 ?m olivine crystals could reach 30 mole% fayalite above 1100 K in solar gas if condensation of metallic nickel-<span class="hlt">iron</span> were delayed sufficiently by supersaturation. Consideration of the surface tensions of several phases with equilibrium condensation temperatures above that of metallic <span class="hlt">iron</span> shows that, even if they were supersaturated, they would still nucleate homogeneously above the equilibrium condensation temperature of metallic <span class="hlt">iron</span>. This phenomenon would have provided nuclei for heterogeneous nucleation of metallic nickel-<span class="hlt">iron</span>, thus preventing the latter from supersaturating significantly and preventing olivine from becoming fayalitic. Unless a way is found to make nebular regions far more <span class="hlt">oxidizing</span> than in existing models, it is unlikely that chondrule precursors or the matrix olivine grains of unequilibrated ordinary chondrites obtained their fayalite contents by condensation processes. Perhaps stabilization of FeO occurred after condensation of water ice and accretion of icy planetesimals, during heating of the planetesimals and/or in hot, dense, water-rich vapor plumes generated by impacts on them. This would imply that FeO is a relatively young feature of nebular materials.</p> <div class="credits"> <p class="dwt_author">Grossman, Lawrence; Fedkin, Alexei V.; Simon, Steven B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">187</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20565252"> <span id="translatedtitle"><span class="hlt">Iron-oxidizing</span> bacteria: an environmental and genomic perspective.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In the 1830s, <span class="hlt">iron</span> bacteria were among the first groups of microbes to be recognized for carrying out a fundamental geological process, namely the <span class="hlt">oxidation</span> of <span class="hlt">iron</span>. Due to lingering questions about their metabolism, coupled with difficulties in culturing important community members, studies of Fe-<span class="hlt">oxidizing</span> bacteria (FeOB) have lagged behind those of other important microbial lithotrophic metabolisms. Recently, research on lithotrophic, oxygen-dependent FeOB that grow at circumneutral pH has accelerated. This work is driven by several factors including the recognition by both microbiologists and geoscientists of the role FeOB play in the biogeochemistry of <span class="hlt">iron</span> and other elements. The isolation of new strains of obligate FeOB allowed a better understanding of their physiology and phylogeny and the realization that FeOB are abundant at certain deep-sea hydrothermal vents. These ancient microorganisms offer new opportunities to learn about fundamental biological processes that can be of practical importance. PMID:20565252</p> <div class="credits"> <p class="dwt_author">Emerson, David; Fleming, Emily J; McBeth, Joyce M</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">188</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/14655711"> <span id="translatedtitle">Green rust and <span class="hlt">iron</span> <span class="hlt">oxide</span> formation influences metolachlor dechlorination during zerovalent <span class="hlt">iron</span> treatment.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Electron transfer from zerovalent <span class="hlt">iron</span> (Fe0) to targeted contaminants is affected by initial Fe0 composition, the <span class="hlt">oxides</span> formed during corrosion, and surrounding electrolytes. We previously observed enhanced metolachlor destruction by Fe0 when <span class="hlt">iron</span> or aluminum salts were present in the aqueous matrix and Eh/pH conditions favored formation of green rusts. To understand these enhanced destruction rates, we characterized changes in Fe0 composition during treatment of metolachlor with and without <span class="hlt">iron</span> and aluminum salts. Raman microspectroscopy and X-ray diffraction (XRD) indicated that the <span class="hlt">iron</span> source was initially coated with a thin layer of magnetite (Fe3O4), maghemite (gamma-Fe2O3), and wüstite (FeO). Time-resolved analysis indicated that akaganeite (beta-FeOOH) was the dominant <span class="hlt">oxide</span> formed during Fe0 treatment of metolachlor. Goethite (alpha-FeOOH) and some lepidocrocite (gamma-FeOOH) formed when Al2(SO4)3 was present, while goethite and magnetite (Fe3O4) were identified in Fe0 treatments containing FeSO4. Although conditions favoring formation of sulfate green rust (GR(II); Fe6(OH)12SO4) facilitated Fe0-mediated dechlorination of metolachlor, only adsorption was observed when GR(II) was synthesized (without Fe0) in the presence of metolachlor and Eh/pH changed to favor Fe(III)oxyhydroxide or magnetite formation. In contrast, dechlorination occurred when magnetite or natural goethite was amended with Fe(II) (as FeSO4) at pH 8 and continued as long as additional Fe(II) was provided. While metolachlor was not dechlorinated by GR(II) itself during a 48-h incubation, the GR(II) provided a source of Fe(II) and produced magnetite (and other <span class="hlt">oxide</span> surfaces) that coordinated Fe(II), which then facilitated dechlorination. PMID:14655711</p> <div class="credits"> <p class="dwt_author">Satapanajaru, Tunlawit; Shea, Patrick J; Comfort, Steve D; Roh, Yul</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-11-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">189</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/29315891"> <span id="translatedtitle"><span class="hlt">Oxidative</span> stress and renal injury with intravenous <span class="hlt">iron</span> in patients with chronic kidney disease</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Oxidative</span> stress and renal injury with intravenous <span class="hlt">iron</span> in patients with chronic kidney disease.BackgroundIntravenous <span class="hlt">iron</span> is widely prescribed in patients with chronic kidney disease (CKD) and can cause <span class="hlt">oxidative</span> stress. The relationship of <span class="hlt">oxidative</span> stress and renal injury in patients with CKD is unknown. Whether renal injury can occur at a time point when transferrin is incompletely saturated is also</p> <div class="credits"> <p class="dwt_author">RAJIV AGARWAL; NINA VASAVADA; Nadine G. Sachs; SHAWN CHASE</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">190</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40675432"> <span id="translatedtitle">Sorption and filtration of metals using <span class="hlt">iron-oxide</span>-coated sand</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxides</span> are good adsorbents for uncomplexed metals, some metal-ligand complexes, and many metal oxyanions. However, the adsorbent properties of these <span class="hlt">oxides</span> are not fully exploited in wastewater treatment operations because of difficulties associated with their separation from the aqueous phase. This paper describes experiments in which <span class="hlt">iron</span> <span class="hlt">oxides</span> were coated onto the surface of ordinary filter sand, and this</p> <div class="credits"> <p class="dwt_author">Mark M. Benjamin; Ronald S. Sletten; Robert P. Bailey; Thomas Bennett</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">191</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2835527"> <span id="translatedtitle">GAS-PHASE FLAME SYNTHESIS AND PROPERTIES OF MAGNETIC <span class="hlt">IRON</span> <span class="hlt">OXIDE</span> NANOPARTICLES WITH REDUCED <span class="hlt">OXIDATION</span> STATE</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles of reduced <span class="hlt">oxidation</span> state, mainly in the form of magnetite, have been synthesized utilizing a new continuous, gas-phase, nonpremixed flame method using hydrocarbon fuels. This method takes advantage of the characteristics of the inverse flame, which is produced by injection of <span class="hlt">oxidizer</span> into a surrounding flow of fuel. Unlike traditional flame methods, this configuration allows for the <span class="hlt">iron</span> particle formation to be maintained in a more reducing environment. The effects of flame temperature, oxygen-enrichment and fuel dilution (i.e. the stoichiometric mixture fraction), and fuel composition on particle size, Fe <span class="hlt">oxidation</span> state, and magnetic properties are evaluated and discussed. The crystallite size, Fe(II) fraction, and saturation magnetization were all found to increase with flame temperature. Flames of methane and ethylene were used, and the use of ethylene resulted in particles containing metallic Fe(0), in addition to magnetite, while no Fe(0) was present in samples synthesized using methane. PMID:20228941</p> <div class="credits"> <p class="dwt_author">Kumfer, Benjamin M; Shinoda, Kozo; Jeyadevan, Balachandran; Kennedy, Ian M</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">192</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3690895"> <span id="translatedtitle">Anoxic photochemical <span class="hlt">oxidation</span> of siderite generates molecular hydrogen and <span class="hlt">iron</span> <span class="hlt">oxides</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Photochemical reactions of minerals are underappreciated processes that can make or break chemical bonds. We report the photooxidation of siderite (FeCO3) by UV radiation to produce hydrogen gas and <span class="hlt">iron</span> <span class="hlt">oxides</span> via a two-photon reaction. The calculated quantum yield for the reaction suggests photooxidation of siderite would have been a significant source of molecular hydrogen for the first half of Earth’s history. Further, experimental results indicate this abiotic, photochemical process may have led to the formation of <span class="hlt">iron</span> <span class="hlt">oxides</span> under anoxic conditions. The reaction would have continued through the Archean to at least the early phases of the Great <span class="hlt">Oxidation</span> Event, and provided a mechanism for <span class="hlt">oxidizing</span> the atmosphere through the loss of hydrogen to space, while simultaneously providing a key reductant for microbial metabolism. We propose that the photochemistry of Earth-abundant minerals with wide band gaps would have potentially played a critical role in shaping the biogeochemical evolution of early Earth. PMID:23733945</p> <div class="credits"> <p class="dwt_author">Kim, J. Dongun; Yee, Nathan; Nanda, Vikas; Falkowski, Paul G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">193</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23796630"> <span id="translatedtitle">RGD-conjugated <span class="hlt">iron</span> <span class="hlt">oxide</span> magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin ?(v)?? targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy. PMID:23796630</p> <div class="credits"> <p class="dwt_author">Zheng, S W; Huang, M; Hong, R Y; Deng, S M; Cheng, L F; Gao, B; Badami, D</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">194</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/24503984"> <span id="translatedtitle">Preparation of <span class="hlt">Iron</span> <span class="hlt">Oxide</span>-Entrapped Chitosan Nanoparticles for Stem Cell Labeling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This study intended to prepare <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle-entrapped chitosan (CS) nanoparticles for stem cell labeling. The nanoparticles were synthesized by polymerizing <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle-associated methacrylic acid monomer in the presence of CS. TEM revealed that the well-defined <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles were successfully encapsulated inside the CS nanoparticles. The effect of CS at different [NH2]\\/[COOH] molar ratios on particle size, surface</p> <div class="credits"> <p class="dwt_author">Saowaluk Chaleawlert-umpon; Varissaporn Mayen; Krissanapong Manotham; Nuttaporn Pimpha</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">195</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42774631"> <span id="translatedtitle">Studies of lead retention from aqueous solutions using <span class="hlt">iron?oxide</span>?coated sorbents</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this research, experiments were conducted to study Pb sorption onto engineered <span class="hlt">iron?oxide</span>?coated sand (IOCS) and <span class="hlt">iron?oxide</span>?coated crushed brick (IOCB), as well as onto naturally <span class="hlt">iron?oxide</span>?coated sand (NIOCS). Optical and scanning electron microscopy (SEM) analyses were realised to investigate the surface properties and morphology of the coated sorbents. Infrared spectroscopy and X?ray diffraction techniques were also used to characterise the</p> <div class="credits"> <p class="dwt_author">N. Boujelben; J. Bouzid; Z. Elouear</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">196</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1981MTB....12..691S"> <span id="translatedtitle">Some aspects on porous properties of <span class="hlt">iron</span> <span class="hlt">oxides</span> containing foreign <span class="hlt">oxides</span> reduced by hydrogen</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The objective of this study is to prepare suitable <span class="hlt">iron</span> ores for industrial reduction processes. Therefore, the properties of porous, green and indurated hematite compacts as well as <span class="hlt">iron</span> ore were investigated by quantitatively measuring pore volume, BET surface area and pore size distribution. Furthermore, the influence of foreign <span class="hlt">oxides</span> on porous properties was investigated. Based on these data, the mechanism of sintering process of the compacts was discussed. The results obtained here suggest that the porosity of the compacts after almost 100 pct reduction does not depend upon whether the compacts were indurated or not. Therefore, it would be concluded that indurating the compact is not necessary for pulverized <span class="hlt">iron</span> ores containing foreign <span class="hlt">oxides</span> when reduced in the process such as a fluidized bed system.</p> <div class="credits"> <p class="dwt_author">Suzuki, Y.; Yamamoto, M.; Kotanigawa, T.; Nishida, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">197</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25414974"> <span id="translatedtitle">Greenlighting photoelectrochemical <span class="hlt">oxidation</span> of water by <span class="hlt">iron</span> <span class="hlt">oxide</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Hematite (?-Fe2O3) is one of just a few candidate electrode materials that possess all of the following photocatalyst-essential properties for scalable application to water <span class="hlt">oxidation</span>: excellent stability, earth-abundance, suitability positive valence-band-edge energy, and significant visible light absorptivity. Despite these merits, hematite's modest oxygen evolution reaction kinetics and its poor efficiency in delivering photogenerated holes, especially holes generated by green photons, to the electrode/solution interface, render it ineffective as a practical water-splitting catalyst. Here we show that hole delivery and catalytic utilization can be substantially improved through Ti alloying, provided that the alloyed material is present in ultrathin-thin-film form. Notably, the effects are most pronounced for charges photogenerated by photons with energy comparable to the band gap for excitation of Fe(3d) ? Fe(3d) transitions (i.e., green photons). Additionally, at the optimum Ti substitution level the lifetimes of surface-localized holes, competent for water <span class="hlt">oxidation</span>, are extended. Together these changes explain an overall improvement in photoelectrochemical performance, especially enhanced internal quantum efficiencies, observed upon Ti(IV) incorporation. PMID:25414974</p> <div class="credits"> <p class="dwt_author">Kim, Dong Wook; Riha, Shannon C; DeMarco, Erica J; Martinson, Alex B F; Farha, Omar K; Hupp, Joseph T</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-12-23</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">198</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://homepages.see.leeds.ac.uk/~earlgb/Publications/Shi%20et%20al%20Global%20Biogeo%20Cycl%202011.pdf"> <span id="translatedtitle">Influence of chemical weathering and aging of <span class="hlt">iron</span> <span class="hlt">oxides</span> on the potential <span class="hlt">iron</span> solubility of Saharan dust during</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Influence of chemical weathering and aging of <span class="hlt">iron</span> <span class="hlt">oxides</span> on the potential <span class="hlt">iron</span> solubility. In this study, we investigated how the nature of Fe minerals in the dust affects its potential Fe solubility minerals present in the samples and Fe solubilities of corresponding standard minerals. The calculated</p> <div class="credits"> <p class="dwt_author">Benning, Liane G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">199</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://homepages.see.leeds.ac.uk/~earlgb/Publications/raiswell_etal_gca_2006.pdf"> <span id="translatedtitle">Contributions from glacially derived sediment to the global <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> cycle: Implications for <span class="hlt">iron</span> delivery to the oceans</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">for <span class="hlt">iron</span> delivery to the oceans Rob Raiswell a,*, Martyn Tranter b , Liane G. Benning a , Martin Siegert b of glacial sediment delivery to the oceans have been derived from fluxes of meltwater runoff and iceberg, and Antarctic locations all contain <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> nanoparticles, which are poorly crystalline, typically</p> <div class="credits"> <p class="dwt_author">Benning, Liane G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">200</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25488041"> <span id="translatedtitle">Conductive <span class="hlt">iron</span> <span class="hlt">oxides</span> accelerate thermophilic methanogenesis from acetate and propionate.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Anaerobic digester is one of the attractive technologies for treatment of organic wastes and wastewater, while continuous development and improvements on their stable operation with efficient organic removal are required. Particles of conductive <span class="hlt">iron</span> <span class="hlt">oxides</span> (e.g., magnetite) are known to facilitate microbial interspecies electron transfer (termed as electric syntrophy). Electric syntrophy has been reported to enhance methanogenic degradation of organic acids by mesophilic communities in soil and anaerobic digester. Here we investigated the effects of supplementation of conductive <span class="hlt">iron</span> <span class="hlt">oxides</span> (magnetite) on thermophilic methanogenic microbial communities derived from a thermophilic anaerobic digester. Supplementation of magnetite accelerated methanogenesis from acetate and propionate under thermophilic conditions, while supplementation of ferrihydrite also accelerated methanogenesis from propionate. Microbial community analysis revealed that supplementation of magnetite drastically changed bacterial populations in the methanogenic acetate-degrading cultures, in which Tepidoanaerobacter sp. and Coprothermobacter sp. dominated. These results suggest that supplementation of magnetite induce electric syntrophy between organic acid-<span class="hlt">oxidizing</span> bacteria and methanogenic archaea and accelerate methanogenesis even under thermophilic conditions. Findings from this study would provide a possibility for the achievement of stably operating thermophilic anaerobic digestion systems with high efficiency for removal of organics and generation of CH4. PMID:25488041</p> <div class="credits"> <p class="dwt_author">Yamada, Chihaya; Kato, Souichiro; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_9");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a 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class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">201</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=64608"> <span id="translatedtitle">AN EFFICIENT AND ECOFRIENDLY <span class="hlt">OXIDATION</span> OF ALKENES USING <span class="hlt">IRON</span> NITRATE AND MOLECULAR OXYGEN</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">An environmentally friendly solventless <span class="hlt">oxidation</span> of alkenes is accomplished efficiently using relatively benign <span class="hlt">iron</span> nitrate as catalyst in the pressence of molecular oxygen under pressurized conditions....</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">202</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012TePhL..38..955V"> <span id="translatedtitle">Synthesis of Fe x O y nanoparticles during <span class="hlt">iron</span> <span class="hlt">oxidation</span> by supercritical water</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">It is established that <span class="hlt">iron</span> is <span class="hlt">oxidized</span> by supercritical water (SCW) with the formation of H2 and nanoparticles of <span class="hlt">iron</span> <span class="hlt">oxides</span> (Fe3O4, FeO, and ?-Fe2O3). The kinetics of H2 production and <span class="hlt">iron</span> <span class="hlt">oxidation</span> has been studied by SCW injection at T = 673, 723, 773, 823, and 873 K into a reactor with <span class="hlt">iron</span> particles. Data of X-ray diffraction and transmission electron microscopy show that the phase composition and morphology of synthesized <span class="hlt">oxide</span> nanoparticles depend on the SCW temperature.</p> <div class="credits"> <p class="dwt_author">Vostrikov, A. A.; Fedyaeva, O. N.; Shishkin, A. V.; Sokol, M. Ya.; Zaikovskii, A. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">203</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3541049"> <span id="translatedtitle">Enriched <span class="hlt">Iron</span>(III)-Reducing Bacterial Communities are Shaped by Carbon Substrate and <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Mineralogy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Iron</span> (Fe) <span class="hlt">oxides</span> exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) <span class="hlt">oxides</span> (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) <span class="hlt">oxides</span> within sedimentary environments? Further, how do changes in Fe mineralogy shape <span class="hlt">oxide</span>-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) <span class="hlt">oxides</span> (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe <span class="hlt">oxides</span> spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe <span class="hlt">oxide</span> type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe <span class="hlt">oxides</span> were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe <span class="hlt">oxide</span> structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments. PMID:23316187</p> <div class="credits"> <p class="dwt_author">Lentini, Christopher J.; Wankel, Scott D.; Hansel, Colleen M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">204</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/370154"> <span id="translatedtitle">Partial <span class="hlt">oxidation</span> of {alpha}-olefins over <span class="hlt">iron</span> antimony <span class="hlt">oxide</span> - influence of carbon number</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Iron</span> antimony <span class="hlt">oxide</span> is a well known catalyst for the partial <span class="hlt">oxidation</span> of propane and 1-butene. Kinetic studies of the partial <span class="hlt">oxidation</span> of {alpha}-olefins (C{sub 2}-C{sub 9}) revealed that the activity showed a maximum at C{sub 4}. The main products of the partial <span class="hlt">oxidation</span> of {alpha}-olefins (larger than C{sub 2}) are the conjugated alkenal (acrolein) and dienes. The selectivity to these desired products decreases with increasing chain length probably caused by both the decrease in number of allylic hydrogen atoms and the shielding of them. Ethene could only be <span class="hlt">oxidized</span> at relatively high temperatures (over 450{degrees}C) and the only observed products were CO and CO{sub 2} indicating the need for the presence of allylic hydrogen for low temperature selective partial <span class="hlt">oxidation</span>. Increasing the carbon number increases the yield of CO and CO{sub 2} due to shielding of the allylic hydrogen.</p> <div class="credits"> <p class="dwt_author">Steen, E. van; Schnobel, M.; O`Connor, C.T. [Univ. of Cape Town, Rondebosch (South Africa)</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">205</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70010273"> <span id="translatedtitle">Reactions of metal ions at surfaces of hydrous <span class="hlt">iron</span> <span class="hlt">oxide</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Cu, Ag and Cr concentrations in natural water may be lowered by mild chemical reduction involving ferric hydroxide-ferrous ion redox processes. V and Mo solubilities may be controlled by precipitation of ferrous vanadate or molybdate. Concentrations as low as 10-8.00 or 10-9.00 M are readily attainable for all these metals in oxygen-depleted systems that are relatively rich in Fe. Deposition of manganese <span class="hlt">oxides</span> such as Mn3O4 can be catalyzed in oxygenated water by coupling to ferrous-ferric redox reactions. Once formed, these <span class="hlt">oxides</span> may disproportionate, giving Mn4+ <span class="hlt">oxides</span>. This reaction produces strongly <span class="hlt">oxidizing</span> conditions at manganese <span class="hlt">oxide</span> surfaces. The solubility of As is significantly influenced by ferric <span class="hlt">iron</span> only at low pH. Spinel structures such as chromite or ferrites of Cu, Ni, and Zn, are very stable and if locally developed on ferric hydroxide surfaces could bring about solubilities much below 10-9.00 M for divalent metals near neutral pH. Solubilities calculated from thermodynamic data are shown graphically and compared with observed concentrations in some natural systems. ?? 1977.</p> <div class="credits"> <p class="dwt_author">Hem, J.D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">206</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.A33D0191Y"> <span id="translatedtitle">Red Dawn: Characterizing <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Minerals in Atmospheric Dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Atmospheric dust is comprised of many components including small amounts of <span class="hlt">iron</span> <span class="hlt">oxide</span> minerals. Although the <span class="hlt">iron</span> <span class="hlt">oxides</span> make up a small weight percent of the bulk dust, they are important because of their roles in ocean fertilization, controls on climate, and as a potential health hazard to humans. Here we report on the <span class="hlt">iron</span> <span class="hlt">oxide</span> mineralogy in dust from a large dust storm, dubbed Red Dawn, which engulfed eastern Australia along a 3000 km front on 23 September 2009. Red Dawn originated from the lower Lake Eyre Basin of South Australia, western New South Wales (NSW) and southwestern Queensland and was the worst dust storm to have hit the city of Sydney in more than 60 years. Dust samples were collected from various locations across eastern Australia (Lake Cowal, Orange, Hornsby, Sydney) following the Red Dawn event. Our dust collection provides a good opportunity to study the physical and mineralogical properties of <span class="hlt">iron</span> <span class="hlt">oxides</span> from Red Dawn using a combination of reflectance spectroscopy, Mössbauer spectroscopy (MB), and magnetic measurements. Magnetization measurements from 20-400 K reveal that magnetite/maghemite, hematite and goethite are present in all samples with magnetite occurring in trace amounts (< 0.5wt%). However, the amount of magnetite/maghemite even in trace concentrations generally increases from Lake Cowal from west to east (0.01 to 0.29 wt%), with highest magnetite contents in the urban-Sydney sites. These observations indicate the additions of magnetite from local urban sources. Variable temperature Mössbauer spectroscopy (300 K and 4.2 K) indicate that goethite and hematite compose approximately 25-45 % of the Fe-bearing phases in the Orange and Lake Cowal samples. Goethite is more abundant than hematite in the Lake Cowal samples whereas the opposite is observed for Orange. Hematite is observed at both temperatures but goethite only at 4.2 K. The identification of goethite in Mössbauer analyses at low-temperature but not at room temperature indicates the presence of nanogoethite and small particle sizes (< 30 nm). Magnetization experiments indicates that some of the nanogoethite has remanence blocking temperatures above 300 K (and hence larger particle sizes) but it must be a small fraction of the total grain distribution considering that goethite was not indicated at 300 K with Mössbauer. Likewise, Mössbauer spectra indicate that the hematite component is still above the Morin transition (TM=265 K) and in its canted antiferromagnetic state even at 4.2 K. Suppression of the Morin transition in hematite can occur due to reduced crystallinity, cation substitution (e.g., Ti4+, Al 3+), or small particle effects (d< 100 nm). Finally, we compared reflectance with a magnetic parameter (hard isothermal remanent magnetization, HIRM) for ferric <span class="hlt">oxide</span> abundance to assess the degree to which ferric <span class="hlt">oxide</span> in these samples might absorb solar radiation. In samples for which both parameters were obtained, HIRM and average reflectance over the visible wavelengths are correlated as a group (r2=0.24). These results indicate that the ferric <span class="hlt">oxide</span> minerals in Red Dawn dust absorb solar radiation. Much of this ferric <span class="hlt">oxide</span> occurs likely as grain coatings of nanohematite and nanogoethite, thereby providing high surface area to enhance absorption of solar radiation.</p> <div class="credits"> <p class="dwt_author">Yauk, K.; Ottenfeld, C. F.; Reynolds, R. L.; Goldstein, H.; Cattle, S.; Berquo, T. S.; Moskowitz, B. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">207</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24996958"> <span id="translatedtitle"><span class="hlt">Iron</span> increases diabetes-induced kidney injury and <span class="hlt">oxidative</span> stress in rats.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Diabetic nephropathy is both a common and a severe complication of diabetes mellitus. <span class="hlt">Iron</span> is an essential trace element. However, excess <span class="hlt">iron</span> is toxic, playing a role in the pathogenesis of diabetic nephropathy. The present study aimed to determine the extent of the interaction between <span class="hlt">iron</span> and type 2 diabetes in the kidney. Male rats were randomly assigned into four groups: control, <span class="hlt">iron</span> (300-mg/kg <span class="hlt">iron</span> dextran), diabetes (a single dose of intraperitoneal streptozotocin), and <span class="hlt">iron</span> + diabetes group. <span class="hlt">Iron</span> supplementation resulted in a higher liver <span class="hlt">iron</span> content, and diabetic rats showed higher serum glucose compared with control rats, which confirmed the model as <span class="hlt">iron</span> overload and diabetic. It was found that <span class="hlt">iron</span> + diabetes group showed a greater degree of kidney pathological changes, a remarkable reduction in body weight, and a significant increase in relative kidney weight and <span class="hlt">iron</span> accumulation in rat kidneys compared with <span class="hlt">iron</span> or diabetes group. Moreover, malondialdehyde values in the kidney were higher in <span class="hlt">iron</span> + diabetes group than in <span class="hlt">iron</span> or diabetes group, sulfhydryl concentration and glutathione peroxidase activity were decreased by the diabetes and <span class="hlt">iron</span> + diabetes groups, and protein <span class="hlt">oxidation</span> and nitration levels were higher in the kidney of <span class="hlt">iron</span> + diabetes group as compared to <span class="hlt">iron</span> or diabetes group. However, <span class="hlt">iron</span> supplementation did not elevate the glucose level of a diabetic further. These results suggested that <span class="hlt">iron</span> increased the diabetic renal injury probably through increased <span class="hlt">oxidative</span>/nitrative stress and reduced antioxidant capacity instead of promoting a rise in blood sugar levels; <span class="hlt">iron</span> might be a potential cofactor of diabetic nephropathy, and strict control of <span class="hlt">iron</span> would be important under diabetic state. PMID:24996958</p> <div class="credits"> <p class="dwt_author">Gao, Wanxia; Li, Xueli; Gao, Zhonghong; Li, Hailing</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">208</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/8347958"> <span id="translatedtitle">Frequency dependence of MR relaxation times. II. <span class="hlt">Iron</span> <span class="hlt">oxides</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The frequency dependence of T1 and T2 was measured for homogeneous suspensions of magnetite and <span class="hlt">iron</span> oxyhydroxide particles in water with various concentrations of gelatin. The transverse relaxivity showed two types of behavior: (a) For magnetic particles, there was a rapid increase in T2 relaxivity with frequency, followed by a saturation plateau, which accorded with the Langevin magnetization function. From these curves, the magnetic moment of the particle domains was estimated to range from 0.8 to 6.3 x 10(4) Bohr magnetons. (b) For <span class="hlt">iron</span> oxyhydroxide (ferritin, ferrihydrite, and akaganéite) particles, T2 relaxivity increased linearly with frequency, the slope of the increase characteristic for each particle. T2 relaxivity generally increased with increasing gelatin concentration, corresponding to the measured decrease in the water diffusion coefficient. For <span class="hlt">iron</span> <span class="hlt">oxides</span>, homogeneously distributed either as iatrogenic agents or endogenous biominerals, these findings may aid in the interpretation of in vivo relaxivity and the effect on MR imaging. PMID:8347958</p> <div class="credits"> <p class="dwt_author">Bulte, J W; Vymazal, J; Brooks, R A; Pierpaoli, C; Frank, J A</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">209</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014GeCoA.145....1J"> <span id="translatedtitle">Ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> under acidic conditions - The effect of ferric <span class="hlt">oxide</span> surfaces</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In this study, the kinetics of Fe(II) <span class="hlt">oxidation</span> in the presence of the <span class="hlt">iron</span> oxyhydroxides ferrihydrite, Si-ferrihydrite, schwertmannite, lepidocrocite and goethite are investigated over the pH range 4-5.5. Despite limited sorption of Fe(II), the rate of Fe(II) <span class="hlt">oxidation</span> is up to 70-fold faster than in the absence of any Fe oxyhydroxide phase over pH 4.5-5.5. Enhanced Fe(II) <span class="hlt">oxidation</span> was minor or negligible at pH 4 with undetectable amounts of Fe(II) adsorbed to the <span class="hlt">iron</span> oxyhydroxides at this pH. Heterogeneous rate constants derived from kinetic modeling were normalized to the concentration of adsorbed Fe(II) and deviated by no more than 13.8% at pH 4.5, 5 and 5.5, indicating that <span class="hlt">oxidation</span> is proportional to the concentration of adsorbed Fe(II). Average rate constants were found to be: 2.12 ± 0.20, 1.30 ± 0.09, 1.69 ± 0.22, 1.20 ± 0.08 and 0.68 ± 0.09 M-1 s-1 for ferrihydrite, goethite, lepidocrocite, schwertmannite and Si-ferrihydrite, respectively. The role of reactive oxygen species, such as hydrogen peroxide, the hydroxyl radical and superoxide, towards the overall <span class="hlt">oxidation</span> of Fe(II) was examined but found to have only a minor impact on Fe(II) <span class="hlt">oxidation</span> when compared to the effect of heterogeneous <span class="hlt">oxidation</span>.</p> <div class="credits"> <p class="dwt_author">Jones, Adele M.; Griffin, Phillipa J.; Collins, Richard N.; Waite, T. David</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">210</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/23493937"> <span id="translatedtitle">TiO 2 nanotube-supported ruthenium(III) <span class="hlt">hydrated</span> <span class="hlt">oxide</span>: A highly active catalyst for selective <span class="hlt">oxidation</span> of alcohols by oxygen</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Ruthenium(III) <span class="hlt">hydrated</span> <span class="hlt">oxide</span> was deposited onto the surface of TiO2 nanotubes via ion exchange followed by alkali treatment. The catalytic activity of Ru(III)\\/TiO2 catalyst for the selective <span class="hlt">oxidation</span> of alcohols by oxygen was studied in a continuous multichannel, compact reactor. It was found that the activity of Ru(III)\\/TiO2 (turnover frequency [TOF]?450 h?1) is greater than that of a recently reported</p> <div class="credits"> <p class="dwt_author">Dmitry V. Bavykin; Alexei A. Lapkin; Pawel K. Plucinski; Jens M. Friedrich; Frank C. Walsh</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">211</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/doepatents/biblio/866527"> <span id="translatedtitle">Nickel aluminides and nickel-<span class="hlt">iron</span> aluminides for use in <span class="hlt">oxidizing</span> environments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p class="result-summary">Nickel aluminides and nickel-<span class="hlt">iron</span> aluminides treated with hafnium or zirconium, boron and cerium to which have been added chromium to significantly improve high temperature ductility, creep resistance and <span class="hlt">oxidation</span> properties in <span class="hlt">oxidizing</span> environments.</p> <div class="credits"> <p class="dwt_author">Liu, Chain T. (Oak Ridge, TN)</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-03-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">212</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3490434"> <span id="translatedtitle">Rapid Spectrophotometric Technique for Quantifying <span class="hlt">Iron</span> in Cells Labeled with Superparamagnetic <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoparticles: Potential Translation to the Clinic</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Labeling cells with superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> (SPIO) nanoparticles provides the ability to track cells by Magnetic Resonance Imaging. Quantifying intracellular <span class="hlt">iron</span> concentration in SPIO labeled cells would allow for the comparison of agents and techniques used to magnetically label cells. Here we describe a rapid spectrophotometric technique (ST) to quantify <span class="hlt">iron</span> content of SPIO labeled cells, circumventing the previous requirement of an overnight acid digestion. Following lysis with 10% SDS of magnetically labeled cells, quantification of SPIO doped or labeled cells was performed using commonly available spectrophotometric instrument(s) by comparing absorptions at 370 and 750 nm with correction for turbidity of cellular products to determine <span class="hlt">iron</span> content of each sample. Standard curves demonstrated high linear correlation (R2 = 0.998) between absorbance spectra of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles and concentration in known SPIO doped cells. Comparisons of the ST to ICP-MS or NMR relaxometric (R2) determinations of intracellular <span class="hlt">iron</span> contents in SPIO containing samples resulted in significant linear correlation between the techniques (R2 vs. ST, R2>0.992, p<0.0001, ST vs. ICP-MS, R2>0.995, p<0.0001) with the limit of detection of ST for <span class="hlt">iron</span> = 0.66?g/ml. We have developed a rapid straightforward protocol that does not require overnight acid digestion for quantifying <span class="hlt">iron</span> <span class="hlt">oxide</span> content in magnetically labeled cells using readily available analytic instrumentation that should greatly expedite advances in comparing SPIO agents and protocols for labeling cells. PMID:23109392</p> <div class="credits"> <p class="dwt_author">Dadashzadeh, Esmaeel R.; Hobson, Matthew; Bryant, L. Henry; Dean, Dana D.; Frank, Joseph A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">213</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23790206"> <span id="translatedtitle">Morphology of biogenic <span class="hlt">iron</span> <span class="hlt">oxides</span> records microbial physiology and environmental conditions: toward interpreting <span class="hlt">iron</span> microfossils.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Despite the abundance of Fe and its significance in Earth history, there are no established robust biosignatures for Fe(II)-<span class="hlt">oxidizing</span> micro-organisms. This limits our ability to piece together the history of Fe biogeochemical cycling and, in particular, to determine whether Fe(II)-<span class="hlt">oxidizers</span> played a role in depositing ancient <span class="hlt">iron</span> formations. A promising candidate for Fe(II)-<span class="hlt">oxidizer</span> biosignatures is the distinctive morphology and texture of extracellular Fe(III)-oxyhydroxide stalks produced by mat-forming microaerophilic Fe(II)-<span class="hlt">oxidizing</span> micro-organisms. To establish the stalk morphology as a biosignature, morphologic parameters must be quantified and linked to the microaerophilic Fe(II)-<span class="hlt">oxidizing</span> metabolism and environmental conditions. Toward this end, we studied an extant model organism, the marine stalk-forming Fe(II)-<span class="hlt">oxidizing</span> bacterium, Mariprofundus ferrooxydans PV-1. We grew cultures in flat glass microslide chambers, with FeS substrate, creating opposing oxygen/Fe(II) concentration gradients. We used solid-state voltammetric microelectrodes to measure chemical gradients in situ while using light microscopy to image microbial growth, motility, and mineral formation. In low-oxygen (2.7-28 ?m) zones of redox gradients, the bacteria converge into a narrow (100 ?m-1 mm) growth band. As cells <span class="hlt">oxidize</span> Fe(II), they deposit Fe(III)-oxyhydroxide stalks in this band; the stalks orient directionally, elongating toward higher oxygen concentrations. M. ferrooxydans stalks display a narrow range of widths and uniquely biogenic branching patterns, which result from cell division. Together with filament composition, these features (width, branching, and directional orientation) form a physical record unique to microaerophilic Fe(II)-<span class="hlt">oxidizer</span> physiology; therefore, stalk morphology is a biosignature, as well as an indicator of local oxygen concentration at the time of formation. Observations of filamentous Fe(III)-oxyhydroxide microfossils from a ~170 Ma marine Fe-Si hydrothermal deposit show that these morphological characteristics can be preserved in the microfossil record. This study demonstrates the potential of morphological biosignatures to reveal microbiology and environmental chemistry associated with geologic <span class="hlt">iron</span> formation depositional processes. PMID:23790206</p> <div class="credits"> <p class="dwt_author">Krepski, S T; Emerson, D; Hredzak-Showalter, P L; Luther, G W; Chan, C S</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">214</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70019154"> <span id="translatedtitle"><span class="hlt">Iron</span> and manganese <span class="hlt">oxide</span> mineralization in the Pacific</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary"><span class="hlt">Iron</span>, manganese, and <span class="hlt">iron</span>-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. <span class="hlt">Iron</span> and manganese deposits occur in five forms: nodules, crusts, cements, mounds and sediment-hosted stratabound layers. Seafloor <span class="hlt">oxides</span> show a wide range of compositions from nearly pure <span class="hlt">iron</span> to nearly pure manganese end members. Fe/Mn ratios vary from about 24 000 (up to 58% elemental Fe) for hydrothermal seamount ironstones to about 0.001 (up to 52% Mn) for hydrothermal stratabound manganese <span class="hlt">oxides</span> from active volcanic arcs. Hydrogenetic Fe-Mn crusts that occur on most seamounts in the ocean basins have a mean Fe/Mn ratio of 0.7 for open-ocean seamount crusts and 1.2 for continental margin seamount crusts. Fe-Mn nodules of potential economic interest from the Clarion-Clipperton Zone have a mean Fe/Mn ratio of 0.3, whereas the mean ratio for nodules from elsewhere in the Pacific is about 0.7. Crusts are enriched in Co, Ni and Pt and nodules in Cu and Ni, and both have significant concentrations of Pb, Zn, Ba, Mo, V and other elements. In contrast, hydrothermal deposits commonly contain only minor trace metal contents, although there are many exceptions, for example, with Ni contents up to 0.66%, Cr to 1.2%, and Zn to 1.4%. Chondrite-normalized REE patterns generally show a positive Ce anomaly and abundant ??REEs for hydrogenetic and mixed hydrogenetic-diagenetic deposits, whereas the Ce anomaly is negative for hydrothermal deposits and ??REE contents are low. However, the Ce anomaly in crusts may vary from strongly positive in East Pacific crusts to slightly negative in West Pacific crusts, which may reflect the redox conditions of seawater. The concentration of elements in hydrogenetic Fe-Mn crusts depends on a wide variety of water column and crust surface characteristics, whereas concentration of elements in hydrothermal <span class="hlt">oxide</span> deposits depends of the intensity of leaching, rock types leached, and precipitation of sulphides at depth in the hydrothermal system.</p> <div class="credits"> <p class="dwt_author">Hein, J.R.; Koschinsky, A.; Halbach, P.; Manheim, F. T.; Bau, M.; Kang, J.-K.; Lubick, N.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">215</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24734703"> <span id="translatedtitle">Mesoporous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanofibers and their loading capacity of curcumin.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Mesoporous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanofibers were obtained by calcination of electrospun precursors at various temperatures. Their microstructure is influenced by the calcination temperature. As the calcination temperature is at 350 degrees C, the resultant <span class="hlt">iron</span> <span class="hlt">oxide</span> nanofibers largely consist of magnetic Fe3O4 and gamma-Fe2O3, with a specific surface area of about 120 m2/g and magnetization of about 66.5 Am2/kg. When the precursor calcined at 450 degrees C, the pure mesoporous alpha-Fe2O3 nanofibers with a specific surface area of about 92 m2/g are obtained and they show a high loading for curcumin. All the adjusted R-squares for the pseudo-second-order model overtop 0.99 in the initial curcumin ethanol solution concentrations of 30, 40 and 60 microg/mL, which suggests the pseudo-second-order kinetics model fit the adsorption kinetics of curcumin onto the mesoporous alpha-Fe2O3 nanofibers, and the adsorption can reach equilibrium in 60 min. While, Langmuir model (R2 = 0.9980) fits well the curcumin adsorption isotherm onto alpha-Fe2O3 mesoporous nanofibers, and the adsorption capacity is up to 12.48 mg/g at the curcumin concentration of 60 microg/mL. PMID:24734703</p> <div class="credits"> <p class="dwt_author">Wang, Qiuju; Liu, Ruijiang; Shen, Xiangqian; Zou, Lianli; Wu, Dingmei</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">216</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011JPhD...44H5002P"> <span id="translatedtitle">Crystallization process and magnetic properties of amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">This paper studied the crystallization process, phase transition and magnetic properties of amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles prepared by the microwave heating technique. Thermal analysis and magnetodynamics studies revealed many interesting aspects of the amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles. The as-prepared sample was amorphous. Crystallization of the maghemite ?-Fe2O3 (with an activation energy of 0.71 eV) and the hematite ?-Fe2O3 (with an activation energy of 0.97 eV) phase occurred at around 300 °C and 350 °C, respectively. A transition from the maghemite to the hematite occurred at 500 °C with an activation energy of 1.32 eV. A study of the temperature dependence of magnetization supported the crystallization and the phase transformation. Raman shift at 660 cm-1 and absorption band in the infrared spectra at 690 cm-1 showed the presence of disorder in the hematite phase on the nanoscale which is supposed to be the origin of the ferromagnetic behaviour of that antiferromagnetic phase.</p> <div class="credits"> <p class="dwt_author">Phu, N. D.; Ngo, D. T.; Hoang, L. H.; Luong, N. H.; Chau, N.; Hai, N. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">217</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008EPJAP..43..145T"> <span id="translatedtitle">Superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles Proton Nuclear Magnetic Resonance Dispersion curves</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Superparamagnetic nanoparticles are widely used as contrast agents for magnetic resonance imaging. We present the Proton Nuclear Magnetic Resonance Dispersion curves for colloidal suspension of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles used as contrast agents. The systems studied are composed of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles of two different sizes, 80 150nm dextran coated and 300 400nm silicon coated. Previous studies show that the longitudinal relaxation time dispersion as a function of the proton Larmor frequency is not easily obtained for the aqueous colloidal suspension of 300 400nm diameter nanoparticles. We obtained this system longitudinal relaxation time dispersion over a broad range of magnetic fields in a viscous medium. A theoretical model that accounts for the relaxation rate of water protons under the influence of such colloidal superparamagnetic nanoparticles was fitted to the experimental data of both systems. The fit allows access to characteristic parameters of superparamagnetic nanoparticles such as the Néel relaxation time, the nanoparticle radius, particle's magnetic moment and translational correlation time, important parameters for the contrast agent efficiency.</p> <div class="credits"> <p class="dwt_author">Taborda, A.; Carvalho, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">218</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4007256"> <span id="translatedtitle">Evaluation of Nanodispersion of <span class="hlt">Iron</span> <span class="hlt">Oxides</span> Using Various Polymers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">In order to create Fe2O3 and Fe2O3·H2O nanoparticles, various polymers were used as dispersing agents, and the resulting effects on the dispersibility and nanoparticulation of the <span class="hlt">iron</span> <span class="hlt">oxides</span> were evaluated. It was revealed that not only the solution viscosity but also the molecular length of the polymers and the surface tension of the particles affected the dispersibility of Fe2O3 and Fe2O3·H2O particles. Using the dispersing agents 7.5% hydroxypropylcellulose-SSL, 6.0% Pharmacoat 603, 5.0% and 6.5% Pharmacoat 904 and 7.0% Metolose SM-4, Fe2O3 nanoparticles were successfully fabricated by wet milling using Ultra Apex Mill. Fe2O3·H2O nanoparticles could also be produced using 5.0% hydroxypropylcellulose-SSL and 4.0 and 7.0% Pharmacoat 904. The index for dispersibility developed in this study appears to be an effective indicator of success in fabricating nanoparticles of <span class="hlt">iron</span> <span class="hlt">oxides</span> by wet milling using Ultra Apex Mill. PMID:24799739</p> <div class="credits"> <p class="dwt_author">Tanaka, Y.; Ueyama, H.; Ogata, M.; Daikoku, T.; Morimoto, M.; Kitagawa, A.; Imajo, Y.; Tahara, T.; Inkyo, M.; Yamaguchi, N.; Nagata, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">219</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24799739"> <span id="translatedtitle">Evaluation of nanodispersion of <span class="hlt">iron</span> <span class="hlt">oxides</span> using various polymers.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In order to create Fe2O3 and Fe2O3·H2O nanoparticles, various polymers were used as dispersing agents, and the resulting effects on the dispersibility and nanoparticulation of the <span class="hlt">iron</span> <span class="hlt">oxides</span> were evaluated. It was revealed that not only the solution viscosity but also the molecular length of the polymers and the surface tension of the particles affected the dispersibility of Fe2O3 and Fe2O3·H2O particles. Using the dispersing agents 7.5% hydroxypropylcellulose-SSL, 6.0% Pharmacoat 603, 5.0% and 6.5% Pharmacoat 904 and 7.0% Metolose SM-4, Fe2O3 nanoparticles were successfully fabricated by wet milling using Ultra Apex Mill. Fe2O3·H2O nanoparticles could also be produced using 5.0% hydroxypropylcellulose-SSL and 4.0 and 7.0% Pharmacoat 904. The index for dispersibility developed in this study appears to be an effective indicator of success in fabricating nanoparticles of <span class="hlt">iron</span> <span class="hlt">oxides</span> by wet milling using Ultra Apex Mill. PMID:24799739</p> <div class="credits"> <p class="dwt_author">Tanaka, Y; Ueyama, H; Ogata, M; Daikoku, T; Morimoto, M; Kitagawa, A; Imajo, Y; Tahara, T; Inkyo, M; Yamaguchi, N; Nagata, S</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">220</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24911468"> <span id="translatedtitle">Strategies for the biofunctionalization of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The field of nanotechnology applied to medicine (nanomedicine) is developing at a fast pace and is expected to provide solutions for early diagnosis, targeted therapy, and personalized medicine. However, designing nanomaterials for biomedical applications is not a trivial task. Avoidance of the immune system, stability in physiological media, control over the interaction of a nanomaterial with biological entities such as proteins and cell membranes, low toxicity, and optimal bioperformance are critical for the success of the designed nanomaterial. In this Feature Article we provide a concise overview of some of the most recent advances concerning the derivatization of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles for bioapplications. The most important aspects relating to the functionalization of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with carbohydrates, peptides, nucleic acids, and antibodies are covered, highlighting the recent contributions from our research group. We suggest tips for the appropriate (bio)functionalization of these inorganic nanoparticles in order to preserve the biological activity of the attached biomolecules and ensure their subsequent stability in physiological media. PMID:24911468</p> <div class="credits"> <p class="dwt_author">Fratila, Raluca M; Mitchell, Scott G; Del Pino, Pablo; Grazu, Valeria; de la Fuente, Jesús M</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-12-23</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a 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class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">221</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4039207"> <span id="translatedtitle">Magnetic tumor targeting of ?-Glucosidase immobilized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Directed enzyme/prodrug therapy (DEPT) has promising application for cancer therapy. However, most current DEPT strategies face shortcomings such as the loss of enzyme activity during preparation, low delivery and transduction efficiency in vivo, difficult to be monitored. In current study, a novel magnetic directed enzyme/prodrug therapy (MDEPT) was set up by conjugating ?-Glucosidase (?-Glu) to aminated, starch-coated, <span class="hlt">iron</span> <span class="hlt">oxide</span> magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (MNP), abbreviated as ?-Glu-MNP, using glutaraldehyde as the crosslinker. This ?-Glu-MNP was then characterized in detail by size distribution, zeta potential, FTIR spectra, TEM, SQUID and magnetophoretic mobility analysis. Compared to free enzyme, the conjugated ?-Glu on MNP remained 85.54%±6.9% relative activity and showed much better temperature stability. relative activity and showed much better temperature stability. The animal study results showed that ?-Glu-MNP display preferable pharmacokinetics characteristic in relation to MNP. With adscititious magnetic field on the surface of tumor, a significant quantity of ?-Glu-MNP was selectively delivered into a subcutaneous tumor of glioma-bearing mice. Remarkably, the enzyme activity of the delivered ?-Glu in tumor lesions showed as high as 20.123 ± 5.022 mU/g tissue with 2.14 of tumor/non-turmor of ?-Glu activity. PMID:23974977</p> <div class="credits"> <p class="dwt_author">Zhou, Jie; Zhang, Jian; David, Allan E.; Yang, Victor C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">222</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013Nanot..24K5102Z"> <span id="translatedtitle">Magnetic tumor targeting of ?-glucosidase immobilized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Directed enzyme/prodrug therapy (DEPT) has promising application for cancer therapy. However, most current DEPT strategies face shortcomings such as the loss of enzyme activity during preparation, low delivery and transduction efficiency in vivo and difficultly of monitoring. In this study, a novel magnetic directed enzyme/prodrug therapy (MDEPT) was set up by conjugating ?-glucosidase (?-Glu) to aminated, starch-coated, <span class="hlt">iron</span> <span class="hlt">oxide</span> magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (MNPs), abbreviated as ?-Glu-MNP, using glutaraldehyde as the crosslinker. This ?-Glu-MNP was then characterized in detail by size distribution, zeta potential, FTIR spectra, TEM, SQUID and magnetophoretic mobility analysis. Compared to free enzyme, the conjugated ?-Glu on MNPs retained 85.54% ± 6.9% relative activity and showed much better temperature stability. The animal study results showed that ?-Glu-MNP displays preferable pharmacokinetics characteristics in relation to MNPs. With an adscititious magnetic field on the surface of a tumor, a significant quantity of ?-Glu-MNP was selectively delivered into a subcutaneous tumor of a glioma-bearing mouse. Remarkably, the enzyme activity of the delivered ?-Glu in tumor lesions showed as high as 20.123±5.022 mU g-1 tissue with 2.14 of tumor/non-tumor ?-Glu activity.</p> <div class="credits"> <p class="dwt_author">Zhou, Jie; Zhang, Jian; David, Allan E.; Yang, Victor C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">223</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11871557"> <span id="translatedtitle">Effect of <span class="hlt">oxide</span> formation mechanisms on lead adsorption by biogenic manganese (hydr)<span class="hlt">oxides</span>, <span class="hlt">iron</span> (hydr)<span class="hlt">oxides</span>, and their mixtures.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The effects of <span class="hlt">iron</span> and manganese (hydr)<span class="hlt">oxide</span> formation processes on the trace metal adsorption properties of these metal (hydr)<span class="hlt">oxides</span> and their mixtures was investigated by measuring lead adsorption by <span class="hlt">iron</span> and manganese (hydr)<span class="hlt">oxides</span> prepared by a variety of methods. Amorphous <span class="hlt">iron</span> (hydr)<span class="hlt">oxide</span> formed by fast precipitation at pH 7.5 exhibited greater Pb adsorption (gamma(max) = 50 mmol of Pb/mol of Fe at pH 6.0) than <span class="hlt">iron</span> (hydr)<span class="hlt">oxide</span> formed by slow, diffusion-controlled <span class="hlt">oxidation</span> of Fe(II) at pH 4.5-7.0 or goethite. Biogenic manganese(III/IV) (hydr)<span class="hlt">oxide</span> prepared by enzymatic <span class="hlt">oxidation</span> of Mn(II) by the bacterium Leptothrix discophora SS-1 adsorbed five times more Pb (per mole of Mn) than an abiotic manganese (hydr)<span class="hlt">oxide</span> prepared by <span class="hlt">oxidation</span> of Mn(II) with permanganate, and 500-5000 times more Pb than pyrolusite <span class="hlt">oxides</span> (betaMnO2). X-ray crystallography indicated that biogenic manganese (hydr)<span class="hlt">oxide</span> and <span class="hlt">iron</span> (hydr)<span class="hlt">oxide</span> were predominantly amorphous or poorly crystalline and their X-ray diffraction patterns were not significantly affected by the presence of the other (hydr)<span class="hlt">oxide</span> during formation. When <span class="hlt">iron</span> and manganese (hydr)<span class="hlt">oxides</span> were mixed after formation, or for Mn biologically <span class="hlt">oxidized</span> with <span class="hlt">iron</span>(III) (hydr)<span class="hlt">oxide</span> present, observed Pb adsorption was similar to that expected for the mixture based on Langmuir parameters for the individual (hydr)<span class="hlt">oxides</span>. These results indicate that interactions in <span class="hlt">iron</span>/manganese (hydr)<span class="hlt">oxide</span> mixtures related to the formation process and sequence of formation such as site masking, alterations in specific surface area, or changes in crystalline structure either did not occur or had a negligible effect on Pb adsorption by the mixtures. PMID:11871557</p> <div class="credits"> <p class="dwt_author">Nelson, Yarrow M; Lion, Leonard W; Shuler, Michael L; Ghiorse, William C</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">224</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://dspace.mit.edu/handle/1721.1/67696"> <span id="translatedtitle">Characterization of <span class="hlt">Iron</span> Dinitrosyl Species Formed in the Reaction of Nitric <span class="hlt">Oxide</span> with a Biological Rieske Center</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Reactions of nitric <span class="hlt">oxide</span> with cysteine-ligated <span class="hlt">iron</span>?sulfur cluster proteins typically result in disassembly of the <span class="hlt">iron</span>?sulfur core and formation of dinitrosyl <span class="hlt">iron</span> complexes (DNICs). Here we report the first evidence ...</p> <div class="credits"> <p class="dwt_author">Wang, Hongxin</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">225</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17920653"> <span id="translatedtitle">Catalytic <span class="hlt">oxidation</span> of gaseous PCDD/Fs with ozone over <span class="hlt">iron</span> <span class="hlt">oxide</span> catalysts.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Catalytic <span class="hlt">oxidation</span> of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) with ozone (catalytic ozonation) over nano-sized <span class="hlt">iron</span> <span class="hlt">oxides</span> (denoted as FexOy) was carried out at temperature of 120-180 degrees C. The effects of operating temperature, ozone concentration, space velocity (SV) and water vapor contents on PCDD/F removal and destruction efficiencies via catalytic ozonation were investigated. High activity of the <span class="hlt">iron</span> <span class="hlt">oxide</span> catalyst towards PCDD/F decomposition was observed even at low temperatures with the aid of ozone. The PCDD/F removal and destruction efficiencies achieved with FexOy/O3 at 180 degrees C reach 94% and 91%, respectively. In the absence of ozone, the destruction efficiencies of all PCDD/F congeners are below 20% and decrease with increasing chlorination level of PCDD/F congener at lower temperature (120 degrees C). However, in the presence of ozone, the destruction efficiencies of all PCDD/F congeners are over 80% on FexOy/O3 at 180 degrees C. Higher temperature and ozone addition increase the activity of <span class="hlt">iron</span> <span class="hlt">oxide</span> for the decomposition of PCDD/Fs. Additionally, in the presence of 5% water vapor, the destruction efficiency of the PCDD/Fs is above 90% even at lower operating temperature (150 degrees C). It indicates that the presence of appropriate amount of water vapor enhances the catalytic activity for the decomposition of gas-phase PCDD/Fs. PMID:17920653</p> <div class="credits"> <p class="dwt_author">Wang, Hou Chuan; Chang, Shu Hao; Hung, Pao Chang; Hwang, Jyh Feng; Chang, Moo Been</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">226</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/279999"> <span id="translatedtitle">Growth of epitaxial films of <span class="hlt">iron</span> <span class="hlt">oxide</span>, nickel <span class="hlt">oxide</span>, cobalt <span class="hlt">oxide</span>, strontium hexagonal ferrite, and yttrium <span class="hlt">iron</span> garnet by laser ablation (abstract)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Thin films of <span class="hlt">iron</span> <span class="hlt">oxide</span>, nickel <span class="hlt">oxide</span>, cobalt <span class="hlt">oxide</span>, strontium hexagonal ferrite, and yttrium <span class="hlt">iron</span> garnet have been grown by laser ablation. With the exception of Co{sub 3}O{sub 4} deposited on LaAlO{sub 3}, the first three materials deposited on [100] LaAlO{sub 3}, SrTiO{sub 3}, and MgO result in high quality {ital c} axis [100] growth. Co{sub 3}O{sub 4} deposited on LaAlO{sub 3} produces highly oriented but random in-plane growth. Similar highly oriented but random in-plane growth occurs for all three materials deposited on glass. The same three materials deposited on cubic zirconia grow [111] oriented and twinned. Strontium hexagonal ferrite and yttrium <span class="hlt">iron</span> garnet have been deposited on [111] large lattice constant garnet. Epitaxial [0001] films are obtained for the former while the latter gives [111]-oriented films. For yttrium <span class="hlt">iron</span> garnet the closeness of lattice match to the substrate necessitates that the mosaicity (rocking curves) obtained from area maps be compared to the growth temperatures and pressures to determine the optimum growth conditions for epitaxiality. {copyright} {ital 1996 American Institute of Physics.}</p> <div class="credits"> <p class="dwt_author">Kennedy, R.J. [Physics Department, Florida A& M University, Tallahassee, Florida 32307 (United States)] [Physics Department, Florida A& M University, Tallahassee, Florida 32307 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">227</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40182259"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span> dissolution and solubility in the presence of siderophores</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Iron</span> is an essential trace nutrient for most known organisms. The <span class="hlt">iron</span> availability is limited by the solubility and the slow dissolution kinetics of <span class="hlt">iron</span>-bearing mineral phases, particularly in pH neutral or alkaline environments such as carbonatic soils and ocean water. Bacteria, fungi, and plants have evolved <span class="hlt">iron</span> acquisition systems to increase the bioavailability of <span class="hlt">iron</span> in such environments. A</p> <div class="credits"> <p class="dwt_author">Stephan M. Kraemer</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">228</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://dept.lamar.edu/zhanhu/icl/acta%20materialia_2009.pdf"> <span id="translatedtitle">Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with <span class="hlt">iron</span> <span class="hlt">oxide</span> and barium titanate</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">with <span class="hlt">iron</span> <span class="hlt">oxide</span> and barium titanate nanoparticles Z. Guo a,*, S.-E. Lee a , H. Kim a , S. Park a , H.T. Hahn (PU) nanocomposites reinforced with magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles and/or dielectric barium the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability</p> <div class="credits"> <p class="dwt_author">Guo, John Zhanhu</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">229</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/19253373"> <span id="translatedtitle">Magnetic Behavior of O-Carboxymethylchitosan Bounded With <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Two magnetic chitosan derivatives of O-carboxymethylchitosan bounded with <span class="hlt">iron</span> <span class="hlt">oxide</span> particles have been prepared by in situ coprecipitation and incorporation methods. The investigations were focused on structural and magnetic aspects-morphology of <span class="hlt">iron</span> <span class="hlt">oxide</span> particles and overall magnetic behavior of these two magnetic chitosan microspheres. It has been shown that the magnetic properties of the sample prepared by the incorporation method</p> <div class="credits"> <p class="dwt_author">A. Dusza; M. Wojtyniak; N. Nedelko; A. Slawska-Waniewska; J. M. Greneche; C. A. Rodrigues; C. Burger; C. Stringari; A. Debrassi</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">230</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41760877"> <span id="translatedtitle">Adsorption and desorption of natural organic matter on <span class="hlt">iron</span> <span class="hlt">oxide</span>. Mechanisms and models</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This study was undertaken to elucidate the interaction mechanism between NOM (natural organic matter) and <span class="hlt">iron</span> <span class="hlt">oxide</span> surfaces and to develop a predictive model for NOM adsorption and desorption. Results indicated that ligand exchange between carboxyl\\/hydroxyl functional groups of NOM and <span class="hlt">iron</span> <span class="hlt">oxide</span> surfaces was the dominant interaction mechanism, especially under acidic or slightly acidic pH conditions. This conclusion was</p> <div class="credits"> <p class="dwt_author">Baohua Gu; Z. Chen; L. Llang; J. F. McCarthy; J. Schmitt</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">231</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/31776915"> <span id="translatedtitle">Increased <span class="hlt">iron</span> content and RNA <span class="hlt">oxidative</span> damage in skeletal muscle with aging and disuse atrophy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Muscle atrophy with aging or disuse is associated with deregulated <span class="hlt">iron</span> homeostasis and increased <span class="hlt">oxidative</span> stress likely inflicting damage to nucleic acids. Therefore, we investigated RNA and DNA <span class="hlt">oxidation</span>, and <span class="hlt">iron</span> homeostasis in gastrocnemius muscles. Disuse atrophy was induced in 6- and 32-month old male Fischer 344\\/Brown Norway rats by 14 days of hind limb suspension (HS). We show that</p> <div class="credits"> <p class="dwt_author">Tim Hofer; Emanuele Marzetti; Jinze Xu; Arnold Y. Seo; Sukru Gulec; Mitchell D. Knutson; Christiaan Leeuwenburgh; Esther E. Dupont-Versteegden</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">232</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://faculty.eas.ualberta.ca/konhauser/Reprints/Geobiology-JR(2013).pdf"> <span id="translatedtitle">Authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> proxies for marine zinc over geological time and implications for eukaryotic metallome</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> proxies for marine zinc over geological time and implications for eukaryotic, Germany ABSTRACT Here, we explore enrichments in paleomarine Zn as recorded by authigenic <span class="hlt">iron</span> <span class="hlt">oxides</span> linked to biologically intrinsic evolutionary factors. In this case, zinc`s geochemical and biological</p> <div class="credits"> <p class="dwt_author">Konhauser, Kurt</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">233</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/books/n/micad/PEG-S-Au-SPIO/pdf/PEG-S-Au-SPIO.pdf"> <span id="translatedtitle">Thiol-modified poly(ethylene glycol)-conjugated gold/ superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Thiol-modified poly(ethylene glycol)-conjugated gold/ superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles Chemical name: Thiol-modified poly(ethylene glycol)-conjugated gold/superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-targeted Target category: Non-targeted Method of detection: Magnetic resonance imaging (MRI) Source of signal</p> <div class="credits"> <p class="dwt_author">Levin, Judith G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">234</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://lmrt.mit.edu/publications/2008/Park_AdvMat_2008.pdf"> <span id="translatedtitle">DOI: 10.1002/adma.200800004 Magnetic <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoworms for Tumor Targeting</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">DOI: 10.1002/adma.200800004 Magnetic <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoworms for Tumor Targeting and Imaging** By Ji for the diagnosis and treatment of dis- eases.[1­14] Ultrasensitive imaging for early detection of cancers presents some significant challenges. Dextran-coated magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> (IO) nanoparticles</p> <div class="credits"> <p class="dwt_author">Bhatia, Sangeeta</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">235</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25507440"> <span id="translatedtitle">[Neutrophilic lithotrophic <span class="hlt">iron-oxidizing</span> prokaryotes and their role in the biogeochemical processes of the <span class="hlt">iron</span> cycle].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Biology of lithotrophic neutrophilic <span class="hlt">iron-oxidizing</span> prokaryotes and their role in the processes of the biogeochemical cycle of <span class="hlt">iron</span> are discussed. This group of microorganisms is phylogenetically, taxonomically, and physiologically heterogeneous, comprising three metabolically different groups: aerobes, nitrate-dependent anaerobes, and phototrophs; the latter two groups have been revealed relatively recently. Their taxonomy and metabolism are described. Materials on the structure and functioning of the electron transport chain in the course of Fe(II) <span class="hlt">oxidation</span> by members of various physiological groups are discussed. Occurrence of <span class="hlt">iron</span> <span class="hlt">oxidizers</span> in freshwater and marine ecosystems, thermal springs, areas of hydrothermal activity, and underwater volcanic areas are considered. Molecular genetic techniques were used to determine the structure of <span class="hlt">iron-oxidizing</span> microbial communities in various natural ecosystems. Analysis of stable isotope fractioning of 56/54Fe in pure cultures and model experiments revealed predominance of biological <span class="hlt">oxidation</span> over abiotic ones in shallow aquatic habitats and mineral springs, which was especially pronounced under microaerobic conditions at the redox zone boundary. Discovery of anaerobic bacterial Fe(II) <span class="hlt">oxidation</span> resulted in development of new hypotheses concerning the possible role of microorganisms and the mechanisms of formation of the major <span class="hlt">iron</span> ore deposits in Precambrian and early Proterozoic epoch. Paleobiological data are presented on the microfossils and specific biomarkers retrieved from ancient ore samples and confirming involvement of anaerobic biogenic processes in their formation. PMID:25507440</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">236</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25423717"> <span id="translatedtitle">[Neutrophilic lithotrophic <span class="hlt">iron-oxidizing</span> prokaryotes and their role in the biogeochemical processes of the <span class="hlt">iron</span> cycle].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Biology of lithotrophic neutrophilic <span class="hlt">iron-oxidizing</span> prokaryotes and their role in the processes of the biogeochemical cycle of <span class="hlt">iron</span> are discussed. This group of microorganisms is phylogenetically, taxonomically, and physiologically heterogeneous, comprising three metabolically different groups: aerobes, nitrate-dependent anaerobes, and phototrophs; the latter two groups have been revealed relatively recently. Their taxonomy and metabolism are described. Materials on the structure and functioning of the electron transport chain in the course of Fe(II) <span class="hlt">oxidation</span> by members of various physiological groups are discussed. Occurrence of <span class="hlt">iron</span> <span class="hlt">oxidizers</span> in freshwater and marine ecosystems, thermal springs, areas of hydrothermal activity, and underwater volcanic areas are considered. Molecular genetic techniques were used to determine the structure of <span class="hlt">iron-oxidizing</span> microbial communities in various natural ecosystems. Analysis of stable isotope fractioning of 56/54Fe in pure cultures and model experiments revealed predominance of biological <span class="hlt">oxidation</span> over abiotic ones in shallow aquatic habitats and mineral springs, which was especially pronounced under microaerobic conditions at the redox zone boundary. Discovery of anaerobic bacterial Fe(II) <span class="hlt">oxidation</span> resulted in development of new hypotheses concerning the possible role of microorganisms and the mechanisms of formation of the major <span class="hlt">iron</span> ore deposits in Precambrian and early Proterozoic epoch. Paleobiological data are presented on the microfossils and specific biomarkers retrieved from ancient ore samples and confirming involvement of anaerobic biogenic processes in their formation. PMID:25423717</p> <div class="credits"> <p class="dwt_author">Dubinina, G A; Sorokina, A Iu</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">237</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21504536"> <span id="translatedtitle"><span class="hlt">Iron</span> isotope fractionation during microbial dissimilatory <span class="hlt">iron</span> <span class="hlt">oxide</span> reduction in simulated Archaean seawater.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The largest Fe isotope excursion yet measured in marine sedimentary rocks occurs in shales, carbonates, and banded <span class="hlt">iron</span> formations of Neoarchaean and Paleoproterozoic age. The results of field and laboratory studies suggest a potential role for microbial dissimilatory <span class="hlt">iron</span> reduction (DIR) in producing this excursion. However, most experimental studies of Fe isotope fractionation during DIR have been conducted in simple geochemical systems, using pure Fe(III) <span class="hlt">oxide</span> substrates that are not direct analogues to phases likely to have been present in Precambrian marine environments. In this study, Fe isotope fractionation was investigated during microbial reduction of an amorphous Fe(III) <span class="hlt">oxide</span>-silica coprecipitate in anoxic, high-silica, low-sulphate artificial Archaean seawater at 30 °C to determine if such conditions alter the extent of reduction or isotopic fractionations relative to those observed in simple systems. The Fe(III)-Si coprecipitate was highly reducible (c. 80% reduction) in the presence of excess acetate. The coprecipitate did not undergo phase conversion (e.g. to green rust, magnetite or siderite) during reduction. <span class="hlt">Iron</span> isotope fractionations suggest that rapid and near-complete isotope exchange took place among all Fe(II) and Fe(III) components, in contrast to previous work on goethite and hematite, where exchange was limited to the outer few atom layers of the substrate. Large quantities of low-?(56)Fe Fe(II) (aqueous and solid phase) were produced during reduction of the Fe(III)-Si coprecipitate. These findings shed new light on DIR as a mechanism for producing Fe isotope variations observed in Neoarchaean and Paleoproterozoic marine sedimentary rocks. PMID:21504536</p> <div class="credits"> <p class="dwt_author">Percak-Dennett, E M; Beard, B L; Xu, H; Konishi, H; Johnson, C M; Roden, E E</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">238</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/22780979"> <span id="translatedtitle">Electrocatalytic characteristics of uric acid <span class="hlt">oxidation</span> at graphite–zeolite-modified electrode doped with <span class="hlt">iron</span> (III)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A new method is developed for the catalytic <span class="hlt">oxidation</span> of uric acid at graphite–zeolite-modified electrode doped with <span class="hlt">iron</span> (III) (Fe3+Y\\/ZCME). <span class="hlt">Iron</span> (III) exchanged in zeolite Y act as catalyst to <span class="hlt">oxidize</span> uric acid. First, the electrochemical behavior of <span class="hlt">iron</span> (III) incorporated in the zeolite Y-modified electrode was studied. The results illustrate that diffusion controls the ferric\\/ferrous redox process at the</p> <div class="credits"> <p class="dwt_author">M. Mazloum Ardakani; Z. Akrami; H. Kazemian; H. R. Zare</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">239</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007JMMM..310.2405H"> <span id="translatedtitle">Characteristics of hollow microtubes consisting of amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles produced by <span class="hlt">iron</span> <span class="hlt">oxidizing</span> bacteria, Leptothrix ochracea</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Some features of characteristic <span class="hlt">iron</span> <span class="hlt">oxide</span> sheaths which the <span class="hlt">iron</span> <span class="hlt">oxidizing</span> bacteria Leptothrix ochracea ( L. oceracea) formed were studied in order to make clear their morphology microstructure, chemical composition, and crystal structure through scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). Each sheath was a hollow tube with average outer and inner diameters of 1.1 and 1.4 ?m, respectively. Their length ranged from 10 to 200 ?m and the aspect ratio was 10-200. Each sheath was constructed by very small particles with a diameter of less than 100 nm. The hollow sheaths were mainly composed of Fe and O with small amounts of Si and P. The chemical composition analyzed by EDX was roughly Fe:Si:P=80:15:5 with the exception of O. XRD measurement revealed that crystal structures of the sheath were similar to that of 2-line ferrihydrite. The sheath showed spin-glass-like magnetic properties.</p> <div class="credits"> <p class="dwt_author">Hashimoto, H.; Yokoyama, S.; Asaoka, H.; Kusano, Y.; Ikeda, Y.; Seno, M.; Takada, J.; Fujii, T.; Nakanishi, M.; Murakami, R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">240</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19719685"> <span id="translatedtitle">Ultrastructure and potential sub-seafloor evidence of bacteriogenic <span class="hlt">iron</span> <span class="hlt">oxides</span> from Axial Volcano, Juan de Fuca Ridge, north-east Pacific Ocean.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxides</span> from the caldera of Axial Volcano, a site of hydrothermal vent activity along the Juan de Fuca Ridge, were found to consist predominantly of microbial structures in <span class="hlt">hydrated</span> whole mounts examined using an environmental scanning electron microscope. Novel observations were made of the <span class="hlt">iron</span> <span class="hlt">oxides</span> revealing the spatial relationships of the bacteria within to be more consistent with microbial mats than mineral precipitates. The bacterial structures are attributed to the sheaths of Leptothrix ochracea, the stalks of Gallionella ferruginea, and the filaments of a novel <span class="hlt">iron</span> <span class="hlt">oxidizing</span> PV-1 strain, based on the distinctive morphological characteristics of these three bacteria. Energy dispersive X-ray spectroscopy revealed the presence and distribution of Fe, Si, and Cl on the bacterial sheaths, stalks and filaments. The <span class="hlt">iron</span> <span class="hlt">oxides</span> were identified by X-ray diffraction to be two-line ferrihydrite, a poorly ordered <span class="hlt">iron</span> oxyhydroxide. Adsorption of Si in particular to two-line ferrihydrite likely contributes to its stability on the seafloor, and might also be a preservation mechanism creating microfossils of the bacterial structures encrusted with ferrihydrite. Presumptive evidence of the sub-seafloor presence of L. ochracea, G. ferruginea and PV-1 at Axial Volcano was obtained from the presence of these bacteria on a trap that had been placed within an active vent, and also in a vent fluid sample. If indeed these bacteria are present in the sub-seafloor, it may be an indication that the surface expression of <span class="hlt">iron</span> <span class="hlt">oxide</span> deposits at Axial Volcano is minimal in comparison to what exists beneath the seafloor. PMID:19719685</p> <div class="credits"> <p class="dwt_author">Kennedy, C B; Scott, S D; Ferris, F G</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-03-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a 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src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">241</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3361705"> <span id="translatedtitle">Porous <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Ribbons Grown on Graphene for High-Performance Lithium Storage</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A well-designed nanostructure of transition metal <span class="hlt">oxides</span> has been regarded as a key to solve their problems of large volume changes during lithium insertion-desertion processes which are associated with pulverization of the electrodes and rapid capacity decay. Here we report an effective approach for the fabrication of porous <span class="hlt">iron</span> <span class="hlt">oxide</span> ribbons by controlling the nucleation and growth of <span class="hlt">iron</span> precursor onto the graphene surface and followed by an annealing treatment. The resultant <span class="hlt">iron</span> <span class="hlt">oxide</span> ribbons possess large aspect ratio, porous structure, thin feature and enhanced open-edges. These characteristics are favorable for the fast diffusion of lithium ions and electrons, and meanwhile can effectively accommodate the volume change of <span class="hlt">iron</span> <span class="hlt">oxides</span> during the cycling processes. As a consequence, the graphene-induced porous <span class="hlt">iron</span> <span class="hlt">oxide</span> ribbons exhibit a high reversible capacity and excellent cycle stability for lithium storage. PMID:22645643</p> <div class="credits"> <p class="dwt_author">Yang, Shubin; Sun, Yi; Chen, Long; Hernandez, Yenny; Feng, Xinliang; Müllen, Klaus</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">242</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25498641"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span>/cassava starch-supported Ziegler-Natta catalysts for in situ ethylene polymerization.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles were used as supporters for in situ polymerization to produce polymer nanocomposites with well-dispersed fillers in polymer matrix. <span class="hlt">Iron</span> <span class="hlt">oxide</span> could be sustained as colloidal solutions by cassava starch to produce a good dispersion of <span class="hlt">iron</span> <span class="hlt">oxide</span> in the matrix. New supports based on <span class="hlt">iron</span> <span class="hlt">oxide</span>/cassava starch or cassava starch for Ziegler-Natta catalysts were utilized as heterogeneous supporters for partially hydrolyzed triethylaluminum. Then, TiCl4 was immobilized on the supports as catalysts for polymerization of ethylene. High-density polyethylene (HDPE) composites were obtained by the synthesized catalysts. A good dispersion of <span class="hlt">iron</span> <span class="hlt">oxide</span>/cassava starch particles was observed in the synthesized polymer matrix promoting to good mechanical properties of HDPE. PMID:25498641</p> <div class="credits"> <p class="dwt_author">Chancharoenrith, Sittikorn; Kamonsatikul, Choavarit; Namkajorn, Montree; Kiatisevi, Supavadee; Somsook, Ekasith</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">243</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3754957"> <span id="translatedtitle"><span class="hlt">Iron</span> Binding at Specific Sites within the Octameric HbpS Protects Streptomycetes from <span class="hlt">Iron</span>-Mediated <span class="hlt">Oxidative</span> Stress</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The soil bacterium Streptomyces reticuli secretes the octameric protein HbpS that acts as a sensory component of the redox-signalling pathway HbpS-SenS-SenR. This system modulates a genetic response on <span class="hlt">iron</span>- and haem-mediated <span class="hlt">oxidative</span> stress. Moreover, HbpS alone provides this bacterium with a defence mechanism to the presence of high concentrations of <span class="hlt">iron</span> ions and haem. While the protection against haem has been related to its haem-binding and haem-degrading activity, the interaction with <span class="hlt">iron</span> has not been studied in detail. In this work, we biochemically analyzed the <span class="hlt">iron</span>-binding activity of a set of generated HbpS mutant proteins and present evidence showing the involvement of one internal and two exposed D/EXXE motifs in binding of high quantities of ferrous <span class="hlt">iron</span>, with the internal E78XXE81 displaying the tightest binding. We additionally show that HbpS is able to <span class="hlt">oxidize</span> ferrous to ferric <span class="hlt">iron</span> ions. Based on the crystal structure of both the wild-type and the mutant HbpS-D78XXD81, we conclude that the local arrangement of the side chains from the glutamates in E78XXE81 within the octameric assembly is a pre-requisite for interaction with <span class="hlt">iron</span>. The data obtained led us to propose that the exposed and the internal motif build a highly specific route that is involved in the transport of high quantities of <span class="hlt">iron</span> ions into the core of the HbpS octamer. Furthermore, physiological studies using Streptomyces transformants secreting either wild-type or HbpS mutant proteins and different redox-cycling compounds led us to conclude that the <span class="hlt">iron</span>-sequestering activity of HbpS protects these soil bacteria from the hazardous side effects of peroxide- and <span class="hlt">iron</span>-based <span class="hlt">oxidative</span> stress. PMID:24013686</p> <div class="credits"> <p class="dwt_author">Wedderhoff, Ina; Kursula, Inari; Groves, Matthew R.; Ortiz de Orué Lucana, Darío</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">244</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.dragon.lv/exafs/akuzmin/papers/ak85.pdf"> <span id="translatedtitle">Changes in the Local Structure of Nanocrystalline Electrochromic Films of <span class="hlt">Hydrated</span> Nickel Vanadium <span class="hlt">Oxide</span> upon OzoneInduced Coloration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrated</span> thin films of nickel vanadium <span class="hlt">oxide</span> (Ni1?xVxOy), made by reactive DC magnetron sputtering, were studied by X-ray absorption spectroscopy at the Ni and V K-edges using synchrotron radiation. The XANES signals were analysed within the full-multiple-scattering formalism, whereas EXAFS data were modelled within the multi-shell multiple-scattering approach. We found that transparent films exhibit a nanocrystalline NiO-type structure with homogeneous</p> <div class="credits"> <p class="dwt_author">E. Avendano; A. Kuzmin; J. Purans; A. Azens; G. A. Niklasson; C. G. Granqvist</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">245</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/58739496"> <span id="translatedtitle">Changes in the local structure of nanocrystalline electrochromic films of <span class="hlt">hydrated</span> nickel vanadium <span class="hlt">oxide</span> upon ozone-induced coloration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Hydrated</span> thin films of nickel vanadium <span class="hlt">oxide</span> (Ni1?xVxOy), made by reactive DC magnetron sputtering, were studied by x-ray absorption spectroscopy at the Ni and V K-edges using synchrotron radiation. The XANES signals were analysed within the full-multiple-scattering formalism, whereas EXAFS data were modelled within the multi-shell multiple-scattering approach. We found that transparent films exhibit a nanocrystalline NiO-type structure with homogeneous</p> <div class="credits"> <p class="dwt_author">A Kuzmin; J Purans; A Azens; G A Niklasson; C G Granqvist</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">246</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3625229"> <span id="translatedtitle">Dietary <span class="hlt">Iron</span> Concentration May Influence Aging Process by Altering <span class="hlt">Oxidative</span> Stress in Tissues of Adult Rats</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Iron</span> is an essential element. However, in its free form, <span class="hlt">iron</span> participates in redox-reactions, leading to the production of free radicals that increase <span class="hlt">oxidative</span> stress and the risk of damaging processes. Living organisms have an efficient mechanism that regulates <span class="hlt">iron</span> absorption according to their <span class="hlt">iron</span> content to protect against <span class="hlt">oxidative</span> damage. The effects of restricted and enriched-<span class="hlt">iron</span> diets on <span class="hlt">oxidative</span> stress and aging biomarkers were investigated. Adult Wistar rats were fed diets containing 10, 35 or 350 mg/kg <span class="hlt">iron</span> (adult restricted-<span class="hlt">iron</span>, adult control-<span class="hlt">iron</span> and adult enriched-<span class="hlt">iron</span> groups, respectively) for 78 days. Rats aged two months were included as a young control group. Young control group showed higher hemoglobin and hematocrit values, lower levels of <span class="hlt">iron</span> and lower levels of MDA or carbonyl in the major studied tissues than the adult control group. Restricted-<span class="hlt">iron</span> diet reduced <span class="hlt">iron</span> concentrations in skeletal muscle and <span class="hlt">oxidative</span> damage in the majority of tissues and also increased weight loss. Enriched-<span class="hlt">iron</span> diet increased hematocrit values, serum <span class="hlt">iron</span>, gamma-glutamyl transferase, <span class="hlt">iron</span> concentrations and <span class="hlt">oxidative</span> stress in the majority of tissues. As expected, young rats showed higher mRNA levels of heart and hepatic L-Ferritin (Ftl) and kidneys SMP30 as well as lower mRNA levels of hepatic Hamp and interleukin-1 beta (Il1b) and also lower levels of liver protein ferritin. Restricted-<span class="hlt">iron</span> adult rats showed an increase in heart Ftl mRNA and the enriched-<span class="hlt">iron</span> adult rats showed an increase in liver nuclear factor erythroid derived 2 like 2 (Nfe2l2) and Il1b mRNAs and in gut divalent metal transporter-1 mRNA (Slc11a2) relative to the control adult group. These results suggest that <span class="hlt">iron</span> supplementation in adult rats may accelerate aging process by increasing <span class="hlt">oxidative</span> stress while <span class="hlt">iron</span> restriction may retards it. However, <span class="hlt">iron</span> restriction may also impair other physiological processes that are not associated with aging. PMID:23593390</p> <div class="credits"> <p class="dwt_author">Arruda, Lorena Fernandes; Arruda, Sandra Fernandes; Campos, Natália Aboudib; de Valencia, Fernando Fortes; Siqueira, Egle Machado de Almeida</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">247</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/6820225"> <span id="translatedtitle">Instability of waste plumes adsorbed on <span class="hlt">iron</span> <span class="hlt">oxide</span> in soils</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Iron</span> (hydrous) <span class="hlt">oxide</span> coatings on the solid matrix dominate adsorption in many soils. Their adsorption characteristics vary considerably with the composition of the soil pore water. If the latter is not sufficiently buffered, the contaminant distribution between solid and soluble soil phase, Kd (''distribution coefficient''), will change as intruding water differing in chemical composition from the original one in the system progresses through the plume environment. Thus the Kd's at different locations within the plume become time dependent, spatially variable and causally correlated. The conventional constant or stochastic Kd model is not capable of describing contaminant migration in such a situation. A geochemical equilibrium model, the so-called triple layer model, has been incorporated into a transport code and is used to calculate the adsorption processes and thus the Kd as a function of environmental parameters. The major processes occurring are: (1) accumulation of a proton reservoir on the surface itself; (2) development of a charge cloud at a distance of several angstroms from the surface, capable of accommodating contaminant ions; and (3) development of a net charge at the <span class="hlt">oxide</span>/water interface and, consequently, the creation of a cation or anion exchange capacity of the <span class="hlt">oxide</span>.</p> <div class="credits"> <p class="dwt_author">Gruber, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">248</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.B51A0483B"> <span id="translatedtitle">Identification of a membrane cytochrome c from neutrophilic, <span class="hlt">iron-oxidizing</span> Mariprofundus ferrooxydans, strain PV-1</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Neutrophilic-<span class="hlt">iron</span> <span class="hlt">oxidizing</span> bacteria (FeOB) are a group of bacteria that can <span class="hlt">oxidize</span> <span class="hlt">iron</span> at -or near neutral pH, making them relevant in habitats with naturally high levels of reduced <span class="hlt">iron</span> (i.e. Fe2+) such as hydrothermal vents. In the ocean, microorganisms in the Mariprofundus genus (zeta- Proteobacteria) are the only known organisms to chemolithoautotrophically <span class="hlt">oxidize</span> <span class="hlt">iron</span>. In order to identify the active bacterial <span class="hlt">oxidation</span> of <span class="hlt">iron</span> in the environment (i.e. in the deep biosphere), biomarkers for this functionality are needed. The aim of this study is to confirm the expression of potential functional biomarkers that are diagnostic of neutrophilic bacterial <span class="hlt">iron-oxidation</span>. To this end, Mariprofundus ferrooxydans, strain PV-1 was cultivated in large batches and its proteins extracted via a methodology to circumvent protein binding to filamentous material. Proteins were assayed for redox-activity and for <span class="hlt">iron-oxidation</span> activity. The bands of the gel that showed activity were analyzed via LC-MS/MS for identification of peptides and subsequently protein-matched to the M. ferrooxydans proteome database. The results indicate that a membrane cytochrome c with homology to the <span class="hlt">iron-oxidizing</span> Cyt572 from Leptospirillum Group II is expressed in M. ferrooxydans when it is active. Other proteins associated with the electron transport chain of M. ferroxydans such as cbb3-type cytochrome oxidase subunits were identified and validated separately through reverse transcription followed by PCR amplification.</p> <div class="credits"> <p class="dwt_author">Barco, R. A.; Zhong, J.; Ramirez, G. A.; Reese, B. K.; Edwards, K. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">249</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18004545"> <span id="translatedtitle"><span class="hlt">Iron</span> and carbon metabolism by a mineral-<span class="hlt">oxidizing</span> Alicyclobacillus-like bacterium.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A novel <span class="hlt">iron-oxidizing</span>, moderately thermophilic, acidophilic bacterium (strain "GSM") was isolated from mineral spoil taken from a gold mine in Montana. Biomolecular analysis showed that it was most closely related to Alicyclobacillus tolerans, although the two bacteria differed in some key respects, including the absence (in strain GSM) of varpi-alicyclic fatty acids and in their chromosomal base compositions. Isolate GSM was able to grow in oxygen-free media using ferric <span class="hlt">iron</span> as terminal electron acceptor confirming that it was a facultative anaerobe, a trait not previously described in Alicyclobacillus spp.. The acidophile used both organic and inorganic sources of energy and carbon, although growth and <span class="hlt">iron</span> <span class="hlt">oxidation</span> by isolate GSM was uncoupled in media that contained both fructose and ferrous <span class="hlt">iron</span>. Fructose utilization suppressed <span class="hlt">iron</span> <span class="hlt">oxidation</span>, and <span class="hlt">oxidation</span> of ferrous <span class="hlt">iron</span> occurred only when fructose was depleted. In contrast, fructose catabolism was suppressed when bacteria were harvested while actively <span class="hlt">oxidizing</span> <span class="hlt">iron</span>, suggesting that both ferrous <span class="hlt">iron</span>- and fructose-<span class="hlt">oxidation</span> are inducible in this acidophile. Isolate GSM accelerated the <span class="hlt">oxidative</span> dissolution of pyrite in liquid media either free of, or amended with, organic carbon, although redox potentials were significantly different in these media. The potential of this isolate for commercial mineral processing is discussed. PMID:18004545</p> <div class="credits"> <p class="dwt_author">Yahya, Adibah; Hallberg, Kevin B; Johnson, D Barrie</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">250</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24583326"> <span id="translatedtitle">The effect of protein <span class="hlt">oxidation</span> on <span class="hlt">hydration</span> and water-binding in pork packaged in an oxygen-enriched atmosphere.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This study investigated the in situ <span class="hlt">oxidative</span> process of myofibrillar proteins in boneless pork loin chops (Longissimus lumborum) packaged in an oxygen-enriched atmosphere (HiOx: 80% O2/20% CO2), an air-permeable polyvinylchloride (PVC) overwrap, or a partial vacuum (VP) throughout display at 2°C for up to 14, 7, and 21days, respectively. Samples stored in HiOx were susceptible to lipid (TBARS) and protein (carbonyls, sulfhydryls, and aggregation) <span class="hlt">oxidation</span>, while samples in PVC and VP showed lesser <span class="hlt">oxidative</span> changes. Water-holding capacity of raw muscle decreased (P<0.05) when stored in HiOx but not in PVC and VP. Upon salt and phosphate brine marination, HiOx and PVC muscle samples had improved <span class="hlt">hydration</span> capacity during display compared with non-stored control, but display generally decreased <span class="hlt">hydration</span> of VP samples. The result was in agreement with myofibril structural changes. Despite the enhanced <span class="hlt">hydration</span>, HiOx muscle was least capable of withholding moisture upon cooking. PMID:24583326</p> <div class="credits"> <p class="dwt_author">Delles, Rebecca M; Xiong, Youling L</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">251</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3640798"> <span id="translatedtitle">Arsenic removal from water using flame-synthesized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with variable <span class="hlt">oxidation</span> states</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">We utilized gas-phase diffusion flame synthesis, which has potential for large-scale production of metal <span class="hlt">oxide</span> nanoparticles, to produce <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (IONPs) with variable <span class="hlt">oxidation</span> states. The efficacy of these materials in removal of arsenate (As(V) ) from water was assessed. Two different flame configurations, a diffusion flame (DF) and an inverse diffusion flame (IDF), were employed to synthesize six different IONPs by controlling flame conditions. The IONPs produced in the IDF configuration (IDF-IONPs) had smaller particle diameters (4.8 – 8.2 nm) and larger surface areas (141–213 m2/g) than the IONPs produced in the DF configuration (29 nm, 36 m2/g), which resulted in their higher adsorption capacities. As(V) adsorption capacities of the IDF-IONPs increased when the IONPs were synthesized in more <span class="hlt">oxidizing</span> conditions. The fully <span class="hlt">oxidized</span> IDF-IONPs, maghemite (?-Fe2O3), showed the highest As(V) adsorption capacity, comparable to that of magnetite nanocrystals synthesized by thermal decomposition of <span class="hlt">iron</span> pentacarbonyl and equivalent to three to four times higher capacity than that of a commonly used goethite-based adsorbent. All IONPs were magnetically responsive, which is of great importance for solid?liquid separation. This study demonstrates that the IONPs synthesized in gas-phase flame, particularly IDF-IONPs, are excellent adsorbents because of their high As(V) sorption capacity, potential for large-scale production, and useful magnetic property. PMID:23645964</p> <div class="credits"> <p class="dwt_author">Abid, Aamir D.; Kanematsu, Masakazu; Young, Thomas M.; Kennedy, Ian M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">252</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25578030"> <span id="translatedtitle">Enhanced removal performance of arsenate and arsenite by magnetic graphene <span class="hlt">oxide</span> with high <span class="hlt">iron</span> <span class="hlt">oxide</span> loading.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>/graphene <span class="hlt">oxide</span> (MGO) with high <span class="hlt">iron</span> loading (51 wt%) has been successfully synthesized using the co-precipitation method, and then used as adsorbents for the removal of arsenate and arsenite from aqueous solutions. The resulting MGO possesses desirable magnetic properties (12.8 emu g(-1)) and excellent adsorption properties for the removal of As(iii) and As(iv) with significantly enhanced adsorption capacities of 54.18 mg g(-1) and 26.76 mg g(-1), respectively. These values are much higher than those of other GO-based composites reported previously. The kinetic, equilibrium and environmental effects (pH, ionic strength, coexist anion) of MGO were obtained experimentally. A synchrotron-based X-ray fluorescent microprobe was used to generate elemental distribution maps of adsorbents; the results suggest that As(v) became preferentially associated with <span class="hlt">iron</span> <span class="hlt">oxides</span> during the adsorption process, and that the distribution of Fe is directly correlated with the distribution of As. PMID:25578030</p> <div class="credits"> <p class="dwt_author">Yu, Fei; Sun, Sainan; Ma, Jie; Han, Sheng</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-28</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">253</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1992PhDT........75P"> <span id="translatedtitle">Initial Stages of <span class="hlt">Oxidation</span> of <span class="hlt">IRON</span>(100) Surface</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Oxygen/metal systems are involved in several important areas, such as catalytic <span class="hlt">oxidation</span>, corrosion processes and surface magnetism. As an example of one important system the surface structure and <span class="hlt">oxidation</span> of the <span class="hlt">iron</span>/oxygen system are of interest. AES, XPS, and LEED have been used to determine the initial uptake of oxygen, crystallographic structure of chemisorbed oxygen, and final state of the <span class="hlt">oxide</span>. The AES measurements, which agree well with results of XPS, show three regions of oxygen adsorption. The chemisorption of oxygen is followed by <span class="hlt">oxide</span> formation and <span class="hlt">oxide</span> growth. The initial oxygen uptake curve increases rapidly with exposure and becomes flat at around 6 L, and then increases nonlinearly. The sticking coefficient corresponding to the oxygen uptake curve decreases rapidly to a minimum at around 6 L oxygen exposure. Beyond this exposure, the sticking coefficient increases to a maximum at around 20L and decreases again. LEED patterns of clean Fe(100) and chemisorbed oxygen on Fe(100) are p(1 x 1). According to results using the Fe MVV transition, we have found that the final state of <span class="hlt">oxide</span> is Fe _2O_3 at room temperature. The photoemission extended x-ray absorption fine structure (PEXAFS) technique has been used to investigate the structures of the clean Fe(100) surface and the <span class="hlt">oxide</span> formed on the Fe(100) surface. This is the first successful PEXAFS measurement using a photopeak of a single crystal substrate. PEXAFS is a powerful tool for surface study because of its surface sensitivity due to the short electron escape depth (about 5A) and its chemical sensitivity permitting selective study of each element in different chemical environments. An Fe 3p core level shift of 2.6(3) eV is observed at the surface of Fe(100) exposed to 50L, 100L and 500L of oxygen. We measured PEXAFS using Fe 3p unshifted and chemically shifted peaks, in constant initial state(CIS) spectroscopy. We determined Fe-Fe distances in the clean <span class="hlt">iron</span>, and Fe-O and Fe-Fe separations in the <span class="hlt">oxide</span>. The results for clean Fe(100) are 2.47(4), 2.85(4), 4.01(7), and 4.71(7) A for the 1st, 2nd, 3rd, and 4th nearest neighbor Fe-Fe distances, respectively, which agree well with the known bulk values. The two Fe-O distances and the Fe-Fe distance of the <span class="hlt">oxide</span> are 2.01(4), 4.48(7) and 3.31(6) A, respectively. These results are also in agreement with the known values of the bulk gamma-Fe_2 O_3. The surface extended electron energy loss fine structure technique, which has the advantage of greater accessibility than synchrotron radiation, also has been applied to the structural study. The correct distances are obtained from SEELFS above the Fe 3p edge using phase shifts calculated with the curve wave approximation but not the plane wave approximation.</p> <div class="credits"> <p class="dwt_author">Park, Yong Seob</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">254</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://depts.washington.edu/kkgroup/publications/PDF/2009_Kalele_JMMM_321.pdf"> <span id="translatedtitle">Probing temperature-sensitive behavior of pNIPAAm-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles using frequency-dependent magnetic measurements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">of detecting the changes in the hydrody- namic volume of the pNIPAAm-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticlesProbing temperature-sensitive behavior of pNIPAAm-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles using frequency t i c l e i n f o Available online 4 March 2009 Keywords: Nanoparticle <span class="hlt">Iron</span> <span class="hlt">oxide</span> pNIPAAm Biomedical</p> <div class="credits"> <p class="dwt_author">Krishnan, Kannan M.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">255</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012LPI....43.1940P"> <span id="translatedtitle"><span class="hlt">Iron</span> (Oxyhydr)<span class="hlt">Oxide</span> Biosignatures in the Brushy Basin Member of the Jurassic Morrison Formation, Colorado Plateau, USA: Analog for Martian Diagenetic <span class="hlt">Iron</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Iron</span> precipitates in modern microbial mats compared with <span class="hlt">iron</span> cements in Jurassic alkaline saline lake sediments show that morphological and chemical biosignatures are present and preserved in <span class="hlt">oxidized</span>, evaporative environments analogous to Mars.</p> <div class="credits"> <p class="dwt_author">Potter-McIntyre, S. L.; Chan, M. A.; McPherson, B. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">256</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25184762"> <span id="translatedtitle">Bioconjugated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocubes: synthesis, functionalization, and vectorization.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A facile bottom-up approach for the synthesis of inorganic/organic bioconjugated nanoprobes based on <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocubes as the core with a nanometric silica shell is demonstrated. Surface coating and functionalization protocols developed in this work offered good control over the shell thickness (8-40 nm) and enabled biovectorization of SiO2@Fe3O4 core-shell structures by covalent attachment of folic acid (FA) as a targeting unit for cellular uptake. The successful immobilization of folic acid was investigated both quantitatively (TGA, EA, XPS) and qualitatively (AT-IR, UV-vis, ?-potential). Additionally, the magnetic behavior of the nanocomposites was monitored after each functionalization step. Cell viability studies confirmed low cytotoxicity of FA@SiO2@Fe3O4 conjugates, which makes them promising nanoprobes for targeted internalization by cells and their imaging. PMID:25184762</p> <div class="credits"> <p class="dwt_author">Wortmann, Laura; Ilyas, Shaista; Niznansky, Daniel; Valldor, Martin; Arroub, Karim; Berger, Nadja; Rahme, Kamil; Holmes, Justin; Mathur, Sanjay</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">257</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25526296"> <span id="translatedtitle">Colloidal stability of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with multivalent polymer surfactants.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This paper introduces a new approach for preparing magnetic colloidal suspensions with electrostatic repulsion between particles and polyelectrolyte surfactants. The surface charge of the <span class="hlt">iron</span> <span class="hlt">oxide</span> particles was positive in acidic aqueous conditions; however the surface charge of the colloid was negative in basic aqueous conditions due to the amphoteric property of Fe2O3. The long-term colloidal stability and particle distribution of the multivalent charged polymers, Poly(4-vinylbenzenesulfonate sodium salt) (PSS), Poly(acrylic acid) (PAA), and Poly(allylamine hydrochloride) (PAH) were compared with the monovalent surfactant sodium dodecyl sulfate (SDS). Both mono- and multivalent surfactant molecules showed good colloidal stability for extended periods of time. However, the particle distribution was dependent on the hydrophobicity of the surfactants' functional groups. Polyelectrolytes with a negatively charged functional group showed good long-term stability of particles and a narrow particle distribution regardless of the acid dissociation constant (pKa) of the polymer. PMID:25526296</p> <div class="credits"> <p class="dwt_author">Choi, Young-Wook; Lee, Hoik; Song, Youngjun; Sohn, Daewon</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">258</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AIPC.1288...26K"> <span id="translatedtitle">Magneto-optical Properties of <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoclusters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have developed a modified synthetic protocol for the growth of monodispersed, superparamagnetic, flower-like colloidal nanoclusters (CNCs) with 40-120 nm average diameters. Importantly, these are consisted of smaller <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocrystals, also with adjustable size (12.2-7.7 nm). We show that their optical properties can be tuned by applying an external magnetic field. Spectrophotometric measurements under these conditions reveal a diffuse reflectance maximum in the visible range, which is related to the CNCs assembly in ordered structures. The increasing field strength leads to a blue shift in the spectral weight when the size of the CNCs is above a critical diameter. The size-dependent characteristics of the CNCs determine their magneto-optical behavior and their potential in photonic crystal based technologies.</p> <div class="credits"> <p class="dwt_author">Kostopoulou, Athanasia; Tsiaoussis, Ioannis; Lappas, Alexandros</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">259</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183648"> <span id="translatedtitle">Heterobifunctional PEG Ligands for Bioconjugation Reactions on <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Ever since <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles have been recognized as promising scaffolds for biomedical applications, their surface functionalization has become even more important. We report the synthesis of a novel polyethylene glycol-based ligand that combines multiple advantageous properties for these applications. The ligand is covalently bound to the surface via a siloxane group, while its polyethylene glycol backbone significantly improves the colloidal stability of the particle in complex environments. End-capping the molecule with a carboxylic acid introduces a variety of coupling chemistry possibilities. In this study an antibody targeting plasminogen activator inhibitor-1 was coupled to the surface and its presence and binding activity was assessed by enzyme-linked immunosorbent assay and surface plasmon resonance experiments. The results indicate that the ligand has high potential towards biomedical applications where colloidal stability and advanced functionality is crucial. PMID:25275378</p> <div class="credits"> <p class="dwt_author">Bloemen, Maarten; Van Stappen, Thomas; Willot, Pieter; Lammertyn, Jeroen; Koeckelberghs, Guy; Geukens, Nick; Gils, Ann; Verbiest, Thierry</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">260</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2015JMMM..374..205Y"> <span id="translatedtitle">Preparation of polylysine-modified superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Polylysine (PLL) coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (SPIONs) have potential in biomedical application. In the present work PEG coated SPIONs (PEG-SPIONs) with the particle size of 9.4±1.4 nm were synthesized by thermal decomposition of Fe(acac)3 in PEG, and then coated with PLL (PLL/PEG-SPIONs). The PEG-SPIONs and PLL/PEG-SPIONs were superparamagnetic with the saturation magnetization of 53 and 44 emu/g, respectively. The hydrodynamic diameter of PEG-SPIONs in deionized water was 18.8 nm, which increased to 21.3-28.2 nm after mixing with different amount of PLL. The zeta potentials of PLL/PEG-SPIONs were -8.9 - -3.4 mV which were changing with time. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that PLL was attached to the PEG-SPIONs.</p> <div class="credits"> <p class="dwt_author">Yang, Gao; Zhang, Baolin; Wang, Jun; Xie, Songbo; Li, Xuan</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_12");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span 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</span> </span> <a id="NextPageLink" onclick='return showDiv("page_15");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">261</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1996GeCoA..60.1531G"> <span id="translatedtitle">Gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> associations under supergene conditions: An experimental approach</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Abstract-The interaction of gold hydroxo-chloro complexes with <span class="hlt">iron</span> <span class="hlt">oxides</span> (ferrihydrites, goethites) during coprecipitation experiments is investigated. Chemical analyses of solids and solutions are coupled with a detailed characterization of the <span class="hlt">iron</span> <span class="hlt">oxides</span> with various methods, including X-ray diffraction, High Resolution Transmission Electron Microscopy (HRTEM), and Mössbauer spectroscopy. HCl solutions containing varying amounts of AuCl 4- and ferric nitrate were titrated to neutral or alkaline pH, resulting in the coprecipitation of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> phases (ferrihydrite or goethite). Reference titrations were performed in the absence of <span class="hlt">iron</span>. Most of the gold was removed from solution in the presence of <span class="hlt">iron</span> <span class="hlt">oxides</span> whereas gold remained dissolved in the reference samples. In association with <span class="hlt">iron</span> <span class="hlt">oxides</span> two forms of gold have been identified by HRTEM and 197Au Mössbauer spectroscopy: metallic gold as well as chloro and/or hydroxo combined gold. This combined gold is in a trivalent state as the primary product which means that a reduction process is not a necessary step for the adsorption of gold species on <span class="hlt">iron</span> <span class="hlt">oxides</span>. Metallic gold characterized in these products by means of HRTEM consists mainly of colloids ranging from 3-60 nm in diameter embedded in the ferrihydrite matrix, as isolated particles or as particles associated with goethite laths. The smallest metallic gold particles detected would be almost invisible to classical observation techniques used for solid phases. In our experiments, <span class="hlt">oxidation</span>-reduction reactions between Fe 2+ and Au 3+ are responsible for the presence of metallic gold observed on the <span class="hlt">iron</span> phases. Photochemical reactions may also take part in the reduction process. Colloidal gold and gold complexes could be associated to the <span class="hlt">iron</span> <span class="hlt">oxides</span> by strong electrostatic interactions. Our results suggest that poorly ordered <span class="hlt">iron</span> <span class="hlt">oxides</span> are highly efficient in trapping gold from solutions thanks to their high surface area, and favor gold precipitation during the first stage of the low temperature genesis of ironrich Au-containing systems.</p> <div class="credits"> <p class="dwt_author">Greffié, Catherine; Benedetti, Marc F.; Parron, Claude; Amouric, Marc</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">262</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1988EnGeo..11..289S"> <span id="translatedtitle"><span class="hlt">Iron</span> sulfide <span class="hlt">oxidation</span> and the chemistry of acid generation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Acid mine drainage, produced from the <span class="hlt">oxidation</span> of <span class="hlt">iron</span> sulfides, often contains elevated levels of dissolved aluminum (AI), <span class="hlt">iron</span> (Fe), and sulfate (SO4) and low pH. Understanding the interactions of these elements associated with acid mine drainage is necessary for proper solid waste management planning. Two eastern oil shales were leached using humidity cell methods. This study used a New Albany Shale (4.6 percent pyrite) and a Chattanooga Shale (1.5 percent pyrite). The leachates from the humidity cells were filtered, and the filtrates were analyzed for total concentrations of cations and anions. After correcting for significant solution species and complexes, ion activities were calculated from total concentrations. The results show that the activities of Fe3+, Fe2+, Al3+, and SO4 2- increased due to the <span class="hlt">oxidation</span> of pyrite. Furthermore, the <span class="hlt">oxidation</span> of pyrite resulted in a decreased pH and an increased pe+pH (redox-potential). The Fe3+ and Fe2+ activities appeared to be controlled by amorphous Fe(OH)3 solid phase above a pH of 6.0 and below pe+pH 11.0. The Fe3+, Fe2+, and SO4 2- activities reached saturation with respect to FeOHSO4 solid phase between pH 3.0 and 6.0 and below pe+pH 11.0 Below a pH of 3.0 and above a pe+pH of 11.0, Fe2+, Fe3+, and SO4 2- activities are supported by FeSO4·7H2O solid phase. Above a pH of 6.0, the Al3+ activity showed an equilibrium with amorphous Al(OH)3 solid phase. Below pH 6.0, Al3+ and SO4 2- activities are regulated by the AlOHSO4 solid phase, irrespective of pe+pH. The results of this study suggest that under <span class="hlt">oxidizing</span> conditions with low to high leaching potential, activities of Al and Fe can be predicted on the basis of secondary mineral formation over a wide range of pH and redox. As a result, the long-term chemistry associated with disposal environments can be largely predicted (including trace elements).</p> <div class="credits"> <p class="dwt_author">Sullivan, Patrick J.; Yelton, Jennifer L.; Reddy, K. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">263</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=203127"> <span id="translatedtitle">Synergistic Competitive Inhibition of Ferrous <span class="hlt">Iron</span> <span class="hlt">Oxidation</span> by Thiobacillus ferrooxidans by Increasing Concentrations of Ferric <span class="hlt">Iron</span> and Cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Oxidation</span> of ferrous <span class="hlt">iron</span> by Thiobacillus ferrooxidans SM-4 was inhibited competitively by increasing concentrations of ferric <span class="hlt">iron</span> or cells. A kinetic analysis showed that binding of one inhibitor did not exclude binding of the other and led to synergistic inhibition by the two inhibitors. Binding of one inhibitor, however, was affected by the other inhibitor, and the apparent inhibition constant increased with increasing concentrations of the other inhibitor. PMID:16348031</p> <div class="credits"> <p class="dwt_author">Lizama, Hector M.; Suzuki, Isamu</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">264</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1073561"> <span id="translatedtitle">Exchange bias in Core-Shell <span class="hlt">Iron-Iron</span> <span class="hlt">Oxide</span> Nanoclusters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">An exchange bias study has been performed on core-shell <span class="hlt">iron-iron</span> <span class="hlt">oxide</span> (Fe-Fe3O4) nanoclusters (NCs) of size 11 nm and 14 nm carrying a different core to shell ratio. NCs show complicated behaviors due to competition between interfacial exchange and Zeeman energy in the presence of magnetic field during cooling. These behaviors are accompanied by the evolution of size- dependent cluster structures in the ferromagnetic-core/ferri- or antiferro-magnetic-shell. Smaller clusters have larger coercive field, exchange bias field, and vertical magnetization shift due to the greater contribution from frozen spins of shell/interfaces. These smaller clusters thus also show more dramatic changes with the training effect. Both sizes of clusters display an additional anomaly of the upper part of the hysteresis loop at 10 K under low cooling field (0.1 kOe). This anomaly decreases with number of loop cycles with same field, and disappear with large cooling field (> 0.1 kOe). It may be caused by the competition between the magnetization reversal and the magnetostatic interactions.</p> <div class="credits"> <p class="dwt_author">Kaur, Maninder; McCloy, John S.; Qiang, You</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-03</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">265</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11878380"> <span id="translatedtitle">Modeling the kinetics of ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> by monochloramine.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The maintenance of disinfectants in distribution systems is necessary to ensure drinking water safety. Reactions with oxidizable species can however lead to undesirable disinfectant losses. Previous work has shown that the presence of Fe(II) can cause monochloramine loss in distribution system waters. This paper further examines these reactions and presents a reaction mechanism and kinetic model. The mechanism includes both aqueous-phase reactions and surface-catalyzed reactions involving the <span class="hlt">iron</span> <span class="hlt">oxide</span> product. In addition, it considers competitive reactions involving the amidogen radical that lead to a nonelementary stoichiometry. Using the method of initial rates, the aqueous-phase reactions were found to have first-order dependencies on Fe(II), NH2Cl, and OH- and a rate coefficient (kNH2Cl,soln) of 3.10 (+/-0.560) x 10(9) M(-2) min(-1). The surface-mediated reactions were modeled by assuming the formation of two surface species: >FeOFe+ and >FeOFeOH. Using numerical techniques, combined rate coefficients for the surface-mediated processes were determined to be 0.56 M(-3) min(-1) and 3.5 x 10(-18) M(-4) min(-1), respectively. The model was then used to examine monochloramine and Fe(II) stability under conditions similar to those observed in distribution systems. Our findings suggest the potential utility of monochloramine as an <span class="hlt">oxidant</span> for Fe(III) removal in drinking water treatment. PMID:11878380</p> <div class="credits"> <p class="dwt_author">Vikesland, Peter J; Valentine, Richard L</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-02-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">266</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25497787"> <span id="translatedtitle">In vitro toxicity of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle: <span class="hlt">Oxidative</span> damages on Hep G2 cells.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">During the past years many studies have been done highlighting the great need for a more thorough understanding of cell-<span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle interactions. To improve our knowledge in this field, there is a great need for standardized protocols that would allow to comparing the cytotoxic potential of any Fe2O3-NP type with previously studied particles. Several approaches are reported that several parameters which are of great importance for Fe2O3 nanoparticle induced toxicity. Nanoparticles because of their very small size can pass through the cell membrane and can make <span class="hlt">oxidative</span> damage in all parts of the cells such as mitochondria, membrane, DNA due to high surface area. This study focuses on acute cytotoxicity of reactive oxygen species and DNA damaging effects of mentioned nanoparticles. Results showed increase of the <span class="hlt">oxidative</span> damage leads cells to the apoptosis, therefore reduced cell viability. It is interesting that all of the results are concentration and time dependent. PMID:25497787</p> <div class="credits"> <p class="dwt_author">Sadeghi, Leila; Tanwir, Farzeen; Yousefi Babadi, Vahid</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">267</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014Nanos...7...38W"> <span id="translatedtitle">Recent progress in magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials as promising photocatalysts</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Photocatalytic degradation of toxic organic pollutants is a challenging tasks in ecological and environmental protection. Recent research shows that the magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite photocatalytic system can effectively break through the bottleneck of single-component semiconductor <span class="hlt">oxides</span> with low activity under visible light and the challenging recycling of the photocatalyst from the final products. With high reactivity in visible light, magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductors can be exploited as an important magnetic recovery photocatalyst (MRP) with a bright future. On this regard, various composite structures, the charge-transfer mechanism and outstanding properties of magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials are sketched. The latest synthesis methods and recent progress in the photocatalytic applications of magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials are reviewed. The problems and challenges still need to be resolved and development strategies are discussed.</p> <div class="credits"> <p class="dwt_author">Wu, Wei; Changzhong Jiang, Affc; Roy, Vellaisamy A. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">268</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25406760"> <span id="translatedtitle">Recent progress in magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials as promising photocatalysts.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Photocatalytic degradation of toxic organic pollutants is a challenging tasks in ecological and environmental protection. Recent research shows that the magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite photocatalytic system can effectively break through the bottleneck of single-component semiconductor <span class="hlt">oxides</span> with low activity under visible light and the challenging recycling of the photocatalyst from the final products. With high reactivity in visible light, magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductors can be exploited as an important magnetic recovery photocatalyst (MRP) with a bright future. On this regard, various composite structures, the charge-transfer mechanism and outstanding properties of magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials are sketched. The latest synthesis methods and recent progress in the photocatalytic applications of magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span>-semiconductor composite nanomaterials are reviewed. The problems and challenges still need to be resolved and development strategies are discussed. PMID:25406760</p> <div class="credits"> <p class="dwt_author">Wu, Wei; Changzhong Jiang; Roy, Vellaisamy A L</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-27</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">269</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24036104"> <span id="translatedtitle">The complex interplay of <span class="hlt">iron</span> metabolism, reactive oxygen species, and reactive nitrogen species: insights into the potential of various <span class="hlt">iron</span> therapies to induce <span class="hlt">oxidative</span> and nitrosative stress.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Production of minute concentrations of superoxide (O2(*-)) and nitrogen monoxide (nitric <span class="hlt">oxide</span>, NO*) plays important roles in several aspects of cellular signaling and metabolic regulation. However, in an inflammatory environment, the concentrations of these radicals can drastically increase and the antioxidant defenses may become overwhelmed. Thus, biological damage may occur owing to redox imbalance-a condition called <span class="hlt">oxidative</span> and/or nitrosative stress. A complex interplay exists between <span class="hlt">iron</span> metabolism, O2(*-), hydrogen peroxide (H2O2), and NO*. <span class="hlt">Iron</span> is involved in both the formation and the scavenging of these species. <span class="hlt">Iron</span> deficiency (anemia) (ID(A)) is associated with <span class="hlt">oxidative</span> stress, but its role in the induction of nitrosative stress is largely unclear. Moreover, oral as well as intravenous (iv) <span class="hlt">iron</span> preparations used for the treatment of ID(A) may also induce <span class="hlt">oxidative</span> and/or nitrosative stress. Oral administration of ferrous salts may lead to high transferrin saturation levels and, thus, formation of non-transferrin-bound <span class="hlt">iron</span>, a potentially toxic form of <span class="hlt">iron</span> with a propensity to induce <span class="hlt">oxidative</span> stress. One of the factors that determine the likelihood of <span class="hlt">oxidative</span> and nitrosative stress induced upon administration of an iv <span class="hlt">iron</span> complex is the amount of labile (or weakly-bound) <span class="hlt">iron</span> present in the complex. Stable dextran-based <span class="hlt">iron</span> complexes used for iv therapy, although they contain only negligible amounts of labile <span class="hlt">iron</span>, can induce <span class="hlt">oxidative</span> and/or nitrosative stress through so far unknown mechanisms. In this review, after summarizing the main features of <span class="hlt">iron</span> metabolism and its complex interplay with O2(*-), H2O2, NO*, and other more reactive compounds derived from these species, the potential of various <span class="hlt">iron</span> therapies to induce <span class="hlt">oxidative</span> and nitrosative stress is discussed and possible underlying mechanisms are proposed. Understanding the mechanisms, by which various <span class="hlt">iron</span> formulations may induce <span class="hlt">oxidative</span> and nitrosative stress, will help us develop better tolerated and more efficient therapies for various dysfunctions of <span class="hlt">iron</span> metabolism. PMID:24036104</p> <div class="credits"> <p class="dwt_author">Koskenkorva-Frank, Taija S; Weiss, Günter; Koppenol, Willem H; Burckhardt, Susanna</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22285550"> <span id="translatedtitle"><span class="hlt">Iron</span> supplementation at high altitudes induces inflammation and <span class="hlt">oxidative</span> injury to lung tissues in rats</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Exposure to high altitudes is associated with hypoxia and increased vulnerability to <span class="hlt">oxidative</span> stress. Polycythemia (increased number of circulating erythrocytes) develops to compensate the high altitude associated hypoxia. <span class="hlt">Iron</span> supplementation is, thus, recommended to meet the demand for the physiological polycythemia. <span class="hlt">Iron</span> is a major player in redox reactions and may exacerbate the high altitudes-associated <span class="hlt">oxidative</span> stress. The aim of this study was to explore the potential <span class="hlt">iron</span>-induced <span class="hlt">oxidative</span> lung tissue injury in rats at high altitudes (6000 ft above the sea level). <span class="hlt">Iron</span> supplementation (2 mg elemental <span class="hlt">iron</span>/kg, once daily for 15 days) induced histopathological changes to lung tissues that include severe congestion, dilatation of the blood vessels, emphysema in the air alveoli, and peribronchial inflammatory cell infiltration. The levels of pro-inflammatory cytokines (IL-1?, IL-6, and TNF-?), lipid peroxidation product and protein carbonyl content in lung tissues were significantly elevated. Moreover, the levels of reduced glutathione and total antioxidant capacity were significantly reduced. Co-administration of trolox, a water soluble vitamin E analog (25 mg/kg, once daily for the last 7 days of <span class="hlt">iron</span> supplementation), alleviated the lung histological impairments, significantly decreased the pro-inflammatory cytokines, and restored the <span class="hlt">oxidative</span> stress markers. Together, our findings indicate that <span class="hlt">iron</span> supplementation at high altitudes induces lung tissue injury in rats. This injury could be mediated through excessive production of reactive oxygen species and induction of inflammatory responses. The study highlights the tissue injury induced by <span class="hlt">iron</span> supplementation at high altitudes and suggests the co-administration of antioxidants such as trolox as protective measures. - Highlights: • <span class="hlt">Iron</span> supplementation at high altitudes induced lung histological changes in rats. • <span class="hlt">Iron</span> induced <span class="hlt">oxidative</span> stress in lung tissues of rats at high altitudes. • <span class="hlt">Iron</span> increased the levels of IL-1?, IL-6 and TNF-? in lung tissues at high altitudes. • Trolox alleviated the <span class="hlt">iron</span>-induced histological and biochemical changes to the lungs.</p> <div class="credits"> <p class="dwt_author">Salama, Samir A., E-mail: salama.3@buckeyemail.osu.edu [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11751 (Egypt); Department of Pharmacology and GTMR Unit, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Omar, Hany A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Maghrabi, Ibrahim A. [Department of Clinical Pharmacy, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); AlSaeed, Mohammed S. [Department of Surgery, College of Medicine, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); EL-Tarras, Adel E. [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia)</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24784347"> <span id="translatedtitle">Biosynthesis of stable <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles in aqueous extracts of Hordeum vulgare and Rumex acetosa plants.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We report the synthesis and characterization of amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles from <span class="hlt">iron</span> salts in aqueous extracts of monocotyledonous (Hordeum vulgare) and dicotyledonous (Rumex acetosa) plants. The nanoparticles were characterized by TEM, absorbance spectroscopy, SAED, EELS, XPS, and DLS methods and were shown to contain mainly <span class="hlt">iron</span> <span class="hlt">oxide</span> and <span class="hlt">iron</span> oxohydroxide. H. vulgare extracts produced amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with diameters of up to 30 nm. These <span class="hlt">iron</span> nanoparticles are intrinsically unstable and prone to aggregation; however, we rendered them stable in the long term by addition of 40 mM citrate buffer pH 3.0. In contrast, amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (diameters of 10-40 nm) produced using R. acetosa extracts are highly stable. The total protein content and antioxidant capacity are similar for both extracts, but pH values differ (H. vulgare pH 5.8 vs R. acetosa pH 3.7). We suggest that the presence of organic acids (such oxalic or citric acids) plays an important role in the stabilization of <span class="hlt">iron</span> nanoparticles, and that plants containing such constituents may be more efficacious for the green synthesis of <span class="hlt">iron</span> nanoparticles. PMID:24784347</p> <div class="credits"> <p class="dwt_author">Makarov, Valentin V; Makarova, Svetlana S; Love, Andrew J; Sinitsyna, Olga V; Dudnik, Anna O; Yaminsky, Igor V; Taliansky, Michael E; Kalinina, Natalia O</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-27</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2907147"> <span id="translatedtitle">Kinetics and Mechanism of <span class="hlt">Oxidation</span> Reactions of Porphyrin-<span class="hlt">Iron</span>(IV)-Oxo Intermediates</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The kinetics of reactions of three porphyrin-<span class="hlt">iron</span>(IV)-oxo derivatives with alkenes and benzylic alcohols were measured. The <span class="hlt">iron</span>-oxo systems studied were 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin-<span class="hlt">iron</span>(IV)-oxo (2a), 5,10,15,20-tetrakis(2,6-difluorophenyl)porphyrin-<span class="hlt">iron</span>(IV)-oxo (2b), and 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin-<span class="hlt">iron</span>(IV)-oxo (2c). Species 2 were stable for hours at room temperature as dilute solutions in acetonitrile and reacted hundreds to thousands of times faster in the presence of high concentrations of substrates. Typical second-order rate constants determined from pseudo-first-order kinetic studies are 1–2 × 10?2 M?1 s?1 for reactions with styrene and 3 × 10?2 M?1 s?1 for reactions with benzyl alcohol. The reactivity order for the <span class="hlt">iron</span>-oxo species was 2a > 2b > 2c, which is inverted from that expected on the basis of the electron demand of the porphyrin macrocycles, and the <span class="hlt">oxidation</span> reaction was suppressed when excess porphyrin-<span class="hlt">iron</span>(III) complex was added to reaction mixtures. These observations indicate that the reactions involve disproportionation of the <span class="hlt">iron</span>(IV)-oxo species 2 to give an <span class="hlt">iron</span>(III) species and a more highly <span class="hlt">oxidized</span> <span class="hlt">iron</span> species, presumed to be <span class="hlt">iron</span>(IV)-oxo porphyrin radical cation, that is the true <span class="hlt">oxidant</span> in the reactions. Analyses of the kinetics of <span class="hlt">oxidations</span> of a series of para-substituted benzylic alcohols with Hammett ?+ substituent constants and with a dual parameter method developed by Jiang (Jiang, X. K. Acc. Chem. Res. 1997, 30, 283) indicated that considerable positive charge developed on the benzylic carbons in the <span class="hlt">oxidation</span> reactions, as expected for electrophilic <span class="hlt">oxidants</span>, and also that substantial radical character developed on the benzyl carbon in the transition states. PMID:17630728</p> <div class="credits"> <p class="dwt_author">Pan, Zhengzheng; Newcomb, Martin</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3663513"> <span id="translatedtitle">Mechanism of Ferrous <span class="hlt">Iron</span> Binding and <span class="hlt">Oxidation</span> by Ferritin from a Pennate Diatom*</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A novel ferritin was recently found in Pseudo-nitzschia multiseries (PmFTN), a marine pennate diatom that plays a major role in global primary production and carbon sequestration into the deep ocean. Crystals of recombinant PmFTN were soaked in <span class="hlt">iron</span> and zinc solutions, and the structures were solved to 1.65–2.2-? resolution. Three distinct <span class="hlt">iron</span> binding sites were identified as determined from anomalous dispersion data from aerobically grown ferrous soaked crystals. Sites A and B comprise the conserved ferroxidase active site, and site C forms a pathway leading toward the central cavity where <span class="hlt">iron</span> storage occurs. In contrast, crystal structures derived from anaerobically grown and ferrous soaked crystals revealed only one ferrous <span class="hlt">iron</span> in the active site occupying site A. In the presence of dioxygen, zinc is observed bound to all three sites. <span class="hlt">Iron</span> <span class="hlt">oxidation</span> experiments using stopped-flow absorbance spectroscopy revealed an extremely rapid phase corresponding to Fe(II) <span class="hlt">oxidation</span> at the ferroxidase site, which is saturated after adding 48 ferrous <span class="hlt">iron</span> to apo-PmFTN (two ferrous <span class="hlt">iron</span> per subunit), and a much slower phase due to <span class="hlt">iron</span> core formation. These results suggest an ordered stepwise binding of ferrous <span class="hlt">iron</span> and dioxygen to the ferroxidase site in preparation for catalysis and a partial mobilization of <span class="hlt">iron</span> from the site following <span class="hlt">oxidation</span>. PMID:23548912</p> <div class="credits"> <p class="dwt_author">Pfaffen, Stephanie; Abdulqadir, Raz; Le Brun, Nick E.; Murphy, Michael E. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/doepatents/biblio/6306801"> <span id="translatedtitle">Decaking of coal or oil shale during pyrolysis in the presence of <span class="hlt">iron</span> <span class="hlt">oxides</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p class="result-summary">A method for producing a fuel from the pyrolysis of coal or oil shale in the presence of <span class="hlt">iron</span> <span class="hlt">oxide</span> in an inert gas atmosphere is described. The method includes the steps of pulverizing feed coal or oil shale, pulverizing <span class="hlt">iron</span> <span class="hlt">oxide</span>, mixing the pulverized feed and <span class="hlt">iron</span> <span class="hlt">oxide</span>, and heating the mixture in a gas atmosphere which is substantially inert to the mixture so as to form a product fuel, which may be gaseous, liquid and/or solid. The method of the invention reduces the swelling of coals, such as bituminous coal and the like, which are otherwise known to swell during pyrolysis. 4 figs., 8 tabs.</p> <div class="credits"> <p class="dwt_author">Rashid Khan, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-05-05</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70026818"> <span id="translatedtitle">Rare earth element partitioning between hydrous ferric <span class="hlt">oxides</span> and acid mine water during <span class="hlt">iron</span> <span class="hlt">oxidation</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Ferrous <span class="hlt">iron</span> rapidly <span class="hlt">oxidizes</span> to Fe (III) and precipitates as hydrous Fe (III) <span class="hlt">oxides</span> in acid mine waters. This study examines the effect of Fe precipitation on the rare earth element (REE) geochemistry of acid mine waters to determine the pH range over which REEs behave conservatively and the range over which attenuation and fractionation occur. Two field studies were designed to investigate REE attenuation during Fe <span class="hlt">oxidation</span> in acidic, alpine surface waters. To complement these field studies, a suite of six acid mine waters with a pH range from 1.6 to 6.1 were collected and allowed to <span class="hlt">oxidize</span> in the laboratory at ambient conditions to determine the partitioning of REEs during Fe <span class="hlt">oxidation</span> and precipitation. Results from field experiments document that even with substantial Fe <span class="hlt">oxidation</span>, the REEs remain dissolved in acid, sulfate waters with pH below 5.1. Between pH 5.1 and 6.6 the REEs partitioned to the solid phases in the water column, and heavy REEs were preferentially removed compared to light REEs. Laboratory experiments corroborated field data with the most solid-phase partitioning occurring in the waters with the highest pH. ?? 2004 Elsevier Ltd. All rights reserved.</p> <div class="credits"> <p class="dwt_author">Verplanck, P.L.; Nordstrom, D.K.; Taylor, H.E.; Kimball, B.A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.geo.uu.nl/Research/Paleomagnetism/publications/Grygar_2003.pdf"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span> mineralogy in late Miocene red beds from La Gloria, Spain: rock-magnetic,</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxide</span> mineralogy in late Miocene red beds from La Gloria, Spain: rock-magnetic, voltammetric March 2002; accepted 20 January 2003 Abstract Free ferric <span class="hlt">oxides</span> of a red bed series were analyzed constituents. Free Fe <span class="hlt">oxides</span> occurred at a concentration of 0.3­2.1%, i.e. in the majority of the samples below</p> <div class="credits"> <p class="dwt_author">Utrecht, Universiteit</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://web.mit.edu/dsadoway/www/135.pdf"> <span id="translatedtitle">Production of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten <span class="hlt">Iron</span> <span class="hlt">Oxide</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">advocated molten <span class="hlt">oxide</span> elec- trolysis (MOE) as a carbon-free alternative to existing metals extrac- tionProduction of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten <span class="hlt">Iron</span> <span class="hlt">Oxide</span> of Resource and Environmental Sciences, Wuhan University, China Molten <span class="hlt">oxide</span> electrolysis (MOE</p> <div class="credits"> <p class="dwt_author">Sadoway, Donald Robert</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/14524461"> <span id="translatedtitle">Development of supported <span class="hlt">iron</span> <span class="hlt">oxide</span> catalyst for destruction of PCDD/F.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Studies on the development of supported <span class="hlt">iron</span> <span class="hlt">oxide</span> catalysts for PCDD/F decomposition using 2-monochlorophenol as a surrogate test compound are presented. <span class="hlt">Iron</span> <span class="hlt">oxide</span> catalysts supported on titania were prepared by two methods: impregnation and the sol-gel method. The latter preparation method resulted in better dispersion of <span class="hlt">iron</span> <span class="hlt">oxide</span> on the surface and the formation of gamma-Fe2O3. This is in contrast to the impregnated samples where alpha-Fe2O3 crystallites were formed. Formation of gamma-Fe2O3 resulted in improved reducibility of the active phase that favorably affected the catalytic <span class="hlt">oxidation</span> properties of the catalyst, i.e., the light-off curves for the sol-gel samples were shifted toward lower temperature. Addition of calcium <span class="hlt">oxide</span> to <span class="hlt">iron</span> <span class="hlt">oxide</span> catalyst further improved the performance of the system through stabilization and increase in the concentration of gamma-Fe2O3 in the sol-gel prepared samples. Addition of calcium <span class="hlt">oxide</span> has a dual effect on the performance of the catalyst. First, it creates oxygen vacancies in the reduction-resistant Fe2O3 octahedral structures, thereby improving the reducibility of the active phase. Second, <span class="hlt">iron</span> <span class="hlt">oxide</span> can transform during decomposition of chlorinated hydrocarbons into <span class="hlt">iron</span> chloride. Calcium <span class="hlt">oxide</span> improved the chlorine transfer from the surface <span class="hlt">iron</span> <span class="hlt">oxide</span> species, thereby providing a relatively fresh surface for further catalytic <span class="hlt">oxidation</span>. Comparison of TPR profiles with the position of light-off curves in 2-monochlorophenol decomposition led to the conclusion that Fe3O4 species are the active phase under conditions that facilitate redox cycling between Fe3+ and Fe2+ ions. PMID:14524461</p> <div class="credits"> <p class="dwt_author">Lomnicki, S; Dellinger, B</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-09-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3353163"> <span id="translatedtitle">Biomedical properties and preparation of <span class="hlt">iron</span> <span class="hlt">oxide</span>-dextran nanostructures by MAPLE technique</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background In this work the chemical structure of dextran-<span class="hlt">iron</span> <span class="hlt">oxide</span> thin films was reported. The films were obtained by MAPLE technique from composite targets containing 10 wt. % dextran with 1 and 5 wt.% <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (IONPs). The IONPs were synthesized by co-precipitation method. A KrF* excimer laser source (? = 248 nm, ?FWHM?25 ns, ? = 10 Hz) was used for the growth of the hybrid, <span class="hlt">iron</span> <span class="hlt">oxide</span> NPs-dextran thin films. Results Dextran coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles thin films were indexed into the spinel cubic lattice with a lattice parameter of 8.36 Å. The particle sized calculated was estimated at around 7.7 nm. The XPS shows that the binding energy of the Fe 2p3/2 of two thin films of dextran coated <span class="hlt">iron</span> <span class="hlt">oxide</span> is consistent with Fe3+ <span class="hlt">oxides</span>. The atomic percentage of the C, O and Fe are 66.71, 32.76 and 0.53 for the films deposited from composite targets containing 1 wt.% maghemite and 64.36, 33.92 and 1.72 respectively for the films deposited from composite targets containing 5 wt.% maghemite. In the case of cells cultivated on dextran coated 5% maghemite ?-Fe2O3, the number of cells and the level of F-actin were lower compared to the other two types of thin films and control. Conclusions The dextran-<span class="hlt">iron</span> <span class="hlt">oxide</span> continuous thin films obtained by MAPLE technique from composite targets containing 10 wt.% dextran as well as 1 and 5 wt.% <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles synthesized by co-precipitation method presented granular surface morphology. Our data proved a good viability of Hep G2 cells grown on dextran coated maghemite thin films. Also, no changes in cells morphology were noticed under phase contrast microscopy. The data strongly suggest the potential use of <span class="hlt">iron</span> <span class="hlt">oxide</span>-dextran nanocomposites as a potential marker for biomedical applications. PMID:22410001</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70027546"> <span id="translatedtitle">Hawaiian submarine manganese-<span class="hlt">iron</span> <span class="hlt">oxide</span> crusts - A dating tool?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Black manganese-<span class="hlt">iron</span> <span class="hlt">oxide</span> crusts form on most exposed rock on the ocean floor. Such crusts are well developed on the steep lava slopes of the Hawaiian Ridge and have been sampled during dredging and submersible dives. The crusts also occur on fragments detached from bedrock by mass wasting, on submerged coral reefs, and on poorly lithified sedimentary rocks. The thickness of the crusts was measured on samples collected since 1965 on the Hawaiian Ridge from 140 dive or dredge localities. Fifty-nine (42%) of the sites were collected in 2001 by remotely operated vehicles (ROVs). The thinner crusts on many samples apparently result from post-depositional breakage, landsliding, and intermittent burial of outcrops by sediment. The maximum crust thickness was selected from each dredge or dive site to best represent crusts on the original rock surface at that site. The measurements show an irregular progressive thickening of the crusts toward the northwest-i.e., progressive thickening toward the older volcanic features with increasing distance from the Hawaiian hotspot. Comparison of the maximum crust thickness with radiometric ages of related subaerial features supports previous studies that indicate a crust-growth rate of about 2.5 mm/m.y. The thickness information not only allows a comparison of the relative exposure ages of two or more features offshore from different volcanoes, but also provides specific age estimates of volcanic and landslide deposits. The data indicate that some of the landslide blocks within the south Kona landslide are the oldest exposed rock on Mauna Loa, Kilauea, or Loihi volcanoes. Crusts on the floors of submarine canyons off Kohala and East Molokai volcanoes indicate that these canyons are no longer serving as channelways for downslope, sediment-laden currents. Mahukona volcano was approximately synchronous with Hilo Ridge, both being younger than Hana Ridge. The Nuuanu landslide is considerably older than the Wailau landslide. The Waianae landslide southwest of Oahu has yielded samples with the greatest manganese-<span class="hlt">iron</span> <span class="hlt">oxide</span> crusts (9.5 mm thick) and therefore apparently represents the oldest submarine material yet found in the study area. The submarine volcanic field 100 km southwest of Oahu is apparently younger than the Waianae landslide. ?? 2004 Geological Society of America.</p> <div class="credits"> <p class="dwt_author">Moore, J.G.; Clague, D.A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_13");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> 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showDiv("page_16");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/15155857"> <span id="translatedtitle">Activation of <span class="hlt">Iron</span> Regulatory Protein1 by <span class="hlt">Oxidative</span> Stress in vitro</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Iron</span> regulatory protein-1 (IRP-1), a central cytoplasmic regulator of cellular <span class="hlt">iron</span> metabolism, is rapidly activated by <span class="hlt">oxidative</span> stress to bind to mRNA <span class="hlt">iron</span>-responsive elements. We have reconstituted the response of IRP-1 to extracellular H2O2 in a system derived from murine B6 fibroblasts permeabilized with streptolysin-O. This procedure allows separation of the cytosol from the remainder of the cells (cell pellet).</p> <div class="credits"> <p class="dwt_author">Kostas Pantopoulos; Matthias W. Hentze</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21698372"> <span id="translatedtitle">Effect of diquat-induced <span class="hlt">oxidative</span> stress on <span class="hlt">iron</span> metabolism in male Fischer-344 rats.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Diquat toxicity causes <span class="hlt">iron</span>-mediated <span class="hlt">oxidative</span> stress; however, it remains unclear how diquat affects <span class="hlt">iron</span> metabolism. Here, we examined the effect of diquat-induced <span class="hlt">oxidative</span> stress on <span class="hlt">iron</span> metabolism in male Fischer-344 rats, with particular focus on gene expression. Hepatic nonheme <span class="hlt">iron</span> content was unchanged until 20 h after diquat treatment. Hepatic free <span class="hlt">iron</span> levels increased markedly in the early stages following treatment and remained elevated for at least 6 h, resulting in severe hepatotoxicity, until returning to control levels at 20 h. The level of hepatic ferritin, especially the H-subunit, increased 20 h after diquat treatment due to elevated hepatic ferritin-H mRNA expression. These results indicate that early elevated levels of free <span class="hlt">iron</span> in the liver of diquat-treated rats cause hepatotoxicity, and that this free <span class="hlt">iron</span> is subsequently sequestered by ferritin synthesized under conditions of <span class="hlt">oxidative</span> stress, thus limiting the pro-<span class="hlt">oxidant</span> challenge of <span class="hlt">iron</span>. The plasma <span class="hlt">iron</span> concentration decreased at 6 and 20 h after diquat treatment, whereas the level of plasma interleukin-6 increased markedly at 3 h and remained high until 20 h. In the liver of diquat-treated rats, expression of hepcidin mRNA was markedly upregulated at 3 and 6 h, whereas ferroportin mRNA expression was downregulated slightly at 20 h. Transferrin receptor 1 mRNA expression was significantly upregulated at 3, 6, and 20 h. These results indicate that inhibition of <span class="hlt">iron</span> release from <span class="hlt">iron</span>-storage tissues, through stimulation of the interleukin-6-hepcidin-ferroportin axis, and enhanced <span class="hlt">iron</span> uptake into hepatocytes, mediated by transferrin receptor 1, cause hypoferremia. PMID:21698372</p> <div class="credits"> <p class="dwt_author">Higuchi, Masashi; Yoshikawa, Yasunaga; Orino, Koichi; Watanabe, Kiyotaka</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.sciencemag.org/content/287/5459/1796.full.pdf"> <span id="translatedtitle">An Archaeal <span class="hlt">Iron-Oxidizing</span> Extreme Acidophile Important in Acid Mine Drainage</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This scientific paper describes the isolation, identification and physiology a new species of <span class="hlt">iron-oxidizing</span> Archaea capable of growth at pH 0. This species was isolated from an acid mine drainage site at <span class="hlt">Iron</span> Mountain, California. Additionally, the authors also discuss the ecological niche occupied by this species and other closely related Thermoplasmales, their contribution to acid mine drainage and their impact on <span class="hlt">iron</span> and sulfur cycles.</p> <div class="credits"> <p class="dwt_author">Banfield, Jilian F.; Bond, Philip L.; Edwards, Katrina J.; Gihring, Thomas M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-09-11</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55926462"> <span id="translatedtitle">Biogeochemistry and bacteriology of ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> in geothermal habitats</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A survey of hot, acid springs in Yellowstone Park has shown that high concentrations of ferrous and ferric <span class="hlt">iron</span> are often present. Total ionic <span class="hlt">iron</span> concentrations in different springs ranged from less than 1 ppm to greater than 200 ppm, and up to 50% of the ionic <span class="hlt">iron</span> was in the ferrous form. Some of these springs also have high</p> <div class="credits"> <p class="dwt_author">Thomas D. Brock; Susan Cook; Sandra Petersen; J. L. Mosser</p> <p class="dwt_publisher"></p> <p class="publishDate">1976-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18803673"> <span id="translatedtitle">Dissimilatory ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> at a low pH: a novel trait identified in the bacterial subclass Rubrobacteridae.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A novel <span class="hlt">iron-oxidizing</span> acidophilic actinobacterium was isolated from spoil material at an abandoned copper mine. Phylogenetic analysis placed the isolate within the Rubrobacteridae subclass of the Actinobacteria. Its optimum temperature and pH for growth are 30-35 degrees C and pH 3.0, respectively. Although it could catalyze the dissimilatory <span class="hlt">oxidation</span> of ferrous <span class="hlt">iron</span>, growth yields declined progressively in media containing ferrous <span class="hlt">iron</span> concentrations >100 microM. The isolate, Pa33, did not grow or <span class="hlt">oxidize</span> <span class="hlt">iron</span> in the absence of organic carbon, and appeared to be an obligate heterotroph. Specific rates of <span class="hlt">iron</span> <span class="hlt">oxidation</span> were much smaller than those determined for the autotrophic <span class="hlt">iron-oxidizing</span> proteobacterium Acidithiobacillus ferrooxidans and the heterotrophic <span class="hlt">iron-oxidizing</span> actinobacterium Ferrimicrobium acidiphilum. <span class="hlt">Iron</span> <span class="hlt">oxidation</span> by isolate Pa33 appears to be a defensive mechanism, in which <span class="hlt">iron</span> <span class="hlt">oxidation</span> converts a soluble species to which the bacterium is sensitive to an <span class="hlt">oxidized</span> species (ferric <span class="hlt">iron</span>) that is highly insoluble in the spoil from which it was isolated. This is the first report of acidophily or dissimilatory <span class="hlt">iron</span> <span class="hlt">oxidation</span> within the Rubrobacteridae subclass and one of very few within the Actinobacteria phylum as a whole. PMID:18803673</p> <div class="credits"> <p class="dwt_author">Bryan, Christopher G; Johnson, David B</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014ApWS....4..175D"> <span id="translatedtitle">Removal of <span class="hlt">iron</span> and arsenic (III) from drinking water using <span class="hlt">iron</span> <span class="hlt">oxide</span>-coated sand and limestone</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A method for removal of <span class="hlt">iron</span> and arsenic (III) from contaminated water using <span class="hlt">iron</span> <span class="hlt">oxide</span>-coated sand and limestone has been developed for drinking water. For the intended use, sand was coated with ferric chloride and used as filtering media. Limestone was added onto the coated sand and the effect of limestone addition on removal efficiency of <span class="hlt">iron</span> and arsenic was monitored. Both batch and column experiments were conducted to investigate the efficiency of coated sand and limestone as filtering media. Maximum removal of <span class="hlt">iron</span> (99.8 %) was obtained with coated sand at a dose of 5 g/100 ml and by adding 0.2 g/100 ml of limestone at pH 7.3. Arsenic (III) removal efficiency increased with the increased dose of coated sand and was best removed at pH 7.12. The maximum adsorption capacity for arsenic (III) obtained from Langmuir model was found to be 0.075 mg/g and the kinetics data followed pseudo-first order better than pseudo-second order. Energy dispersive X-ray analysis and FT-IR study proved the removal of <span class="hlt">iron</span> and arsenic. Column experiment showed removal of <span class="hlt">iron</span> and arsenic (III) to <0.3 mg/l and 10 ?g/l, respectively, from an initial concentration of 20 mg/l (<span class="hlt">iron</span>) and 200 ?g/l (arsenic).</p> <div class="credits"> <p class="dwt_author">Devi, Rashmi R.; Umlong, Iohborlang M.; Das, Bodhaditya; Borah, Kusum; Thakur, Ashim J.; Raul, Prasanta K.; Banerjee, Saumen; Singh, Lokendra</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://hal.archives-ouvertes.fr/docs/00/97/66/13/PDF/Photo-Fenton_oxidation_of_phenol_accepted.pdf"> <span id="translatedtitle">Photo-Fenton <span class="hlt">oxidation</span> of phenol with magnetite as <span class="hlt">iron</span> source Marco Minella,1</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Photo-Fenton <span class="hlt">oxidation</span> of phenol with magnetite as <span class="hlt">iron</span> source Marco Minella,1 Giulia Marchetti,1 irradiation. Very interestingly, the photo-Fenton degradation of phenol was also observed under neutral to promote photo-Fenton reactions even under circumneutral pH conditions, the limited <span class="hlt">iron</span> leaching and its</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=135691"> <span id="translatedtitle"><span class="hlt">OXIDANT</span> GENERATION PROMOTES <span class="hlt">IRON</span> SEQUESTRATION IN BEAS-2B CELLS EXPOSED TO ASBESTOS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">Lung injury following asbestos exposure is associated with an <span class="hlt">oxidative</span> stress that is catalyzed by <span class="hlt">iron</span> in the fiber matrix, complexed to the surface, or both. We tested the hypothesis that the cellular response to asbestos includes the transport and sequestration of this <span class="hlt">iron</span> ...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005JMMM..293...20C"> <span id="translatedtitle">Surface characterisation of dextran-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles prepared by laser pyrolysis and coprecipitation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The favoured mechanism of adsorption of dextran on the surface of maghemite nanoparticles (5 nm) prepared by laser pyrolysis seems to be the collective hydrogen bonding between dextran hydroxyl groups and <span class="hlt">iron</span> <span class="hlt">oxide</span> particle surface. After heating, the formation of a surface complex between the polysaccharide oxygen atoms and the surface <span class="hlt">iron</span> atoms gave rise to a stronger bonding.</p> <div class="credits"> <p class="dwt_author">Carmen Bautista, M.; Bomati-Miguel, Oscar; del Puerto Morales, María; Serna, Carlos J.; Veintemillas-Verdaguer, Sabino</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=166843"> <span id="translatedtitle">*<span class="hlt">OXIDANT</span> GENERATION PROMOTES <span class="hlt">IRON</span> SEQUESTRATION IN BEAS-2B CELLS EXPOSED TO ASBESTOS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">Lung injury after asbestos exposure is associated with an <span class="hlt">oxidative</span> stress that is catalyzed by <span class="hlt">iron</span> in the fiber matrix, complexed to the surface, or both. We tested the hypothesis that the cellular response to asbestos includes the transport and sequestration of this <span class="hlt">iron</span> throu...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54430593"> <span id="translatedtitle">Authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> formation in the estuarine mixing zone of the Yangtze River</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Estuaries are elementary geochemical fronts where river water and seawater mix. Within this mixing zone, <span class="hlt">iron</span> and other non-conservative elements can undergo complex reactions to form new solid phases. In order to understand authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> formation in the Yangtze River Estuary, two onsite water-mixing sets of experiments were conducted, one by mixing variable amounts of unfiltered Yangtze River water</p> <div class="credits"> <p class="dwt_author">D. J. Fan; R. D. Neuser; X. G. Sun; Z. S. Yang; Z. G. Guo; S. K. Zhai</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30485603"> <span id="translatedtitle"><span class="hlt">Iron</span> homeostasis and <span class="hlt">oxidative</span> stress in idiopathic pulmonary alveolar proteinosis: a case-control study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">BACKGROUND: Lung injury caused by both inhaled dusts and infectious agents depends on increased availability of <span class="hlt">iron</span> and metal-catalyzed <span class="hlt">oxidative</span> stress. Because inhaled particles, such as silica, and certain infections can cause secondary pulmonary alveolar proteinosis (PAP), we tested the hypothesis that idiopathic PAP is associated with an altered <span class="hlt">iron</span> homeostasis in the human lung. METHODS: Healthy volunteers (n =</p> <div class="credits"> <p class="dwt_author">Andrew J Ghio; Jacqueline G Stonehuerner; Judy H Richards; Kay M Crissman; Victor L Roggli; Claude A Piantadosi; Martha Sue Carraway</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20066267"> <span id="translatedtitle">Chemical modification of biogenous <span class="hlt">iron</span> <span class="hlt">oxide</span> to create an excellent enzyme scaffold.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The biogenous <span class="hlt">iron</span> <span class="hlt">oxide</span> (BIO) from Leptothrix ochracea was transformed to an organic-inorganic hybrid support to prepare an excellent immobilized enzyme showing high catalytic performance. PMID:20066267</p> <div class="credits"> <p class="dwt_author">Sakai, Takashi; Miyazaki, Yuki; Murakami, Ai; Sakamoto, Noriko; Ema, Tadashi; Hashimoto, Hideki; Furutani, Mitsuaki; Nakanishi, Makoto; Fujii, Tatsuo; Takada, Jun</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-21</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243331"> <span id="translatedtitle">Nitrogen Requirement of <span class="hlt">Iron-Oxidizing</span> Thiobacilli for Acidic Ferric Sulfate Regeneration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Ammonium was shown to be a limiting nutrient for <span class="hlt">iron</span> <span class="hlt">oxidation</span> in cultures of Thiobacillus ferrooxidans. In addition, one strain was also able to assimilate nitrate, but not nitrite, for growth and coupled <span class="hlt">iron</span> <span class="hlt">oxidation</span>. Some amino acids (0.5 mM) were tested as a source of nitrogen; none clearly stimulated bacterial activity and inhibition was commonly encountered. Complex nitrogenous compounds were inhibitory at high concentrations (0.1 to 0.5%, wt/vol) and, at low concentrations, some clearly stimulated the bacterial <span class="hlt">iron</span> <span class="hlt">oxidation</span> in ammonium-limited cultures. Enhancement of <span class="hlt">iron</span> <span class="hlt">oxidation</span> by these compounds was also observed in ammonium-unlimited cultures, suggesting their possible role in providing trace nutrients and possibly carbon for the bacteria. PMID:16345391</p> <div class="credits"> <p class="dwt_author">Tuovinen, Olli H.; Panda, Fern A.; Tsuchiya, Henry M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1132191"> <span id="translatedtitle">Effects of <span class="hlt">Iron</span> <span class="hlt">Oxides</span> on the Rheological Properties of Cementitious Slurry</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxide</span> has been considered a promising host for immobilizing and encapsulating radioactive 99Tc (t1/2=2.1x105 year), which significantly enhances the stability of 99Tc within a cementitious waste form. However, the flow behavior of cementitious slurry containing <span class="hlt">iron</span> <span class="hlt">oxide</span> has never been investigated to ensure its workability, which directly influences the preparation and performance of the cementitious waste form monolith. Variation in the rheological properties of the cementitious slurry were studied using rheometry and ultrasonic wave reflection to understand the effects of various <span class="hlt">iron</span> <span class="hlt">oxides</span> (magnetite, hematite, ferrihydrite, and goethite) during the cement setting and stiffening processes. The rheological behavior significantly varied with the addition of different chemical compounds of <span class="hlt">iron</span> <span class="hlt">oxides</span>. Complementary microscopic characteristics such as colloidal vibration currents, morphology, and particle size distributions further suggest that the most adverse alteration of cement setting and stiffening behavior caused by the presence of goethite may be attributed to its acicular shape.</p> <div class="credits"> <p class="dwt_author">Chung, Chul-Woo; Chun, Jaehun; Wang, Guohui; Um, Wooyong</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-04-02</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=187548"> <span id="translatedtitle"><span class="hlt">Iron</span> homeostatis and <span class="hlt">oxidative</span> stress in idiopathic pulmonary alveolar proteinosis: a case-control study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">ABSTRACT: BACKGROUND: Lung injury caused by both inhaled dusts and infectious agents depends on increased availability of <span class="hlt">iron</span> and metal-catalyzed <span class="hlt">oxidative</span> stress. Because inhaled particles, such as silica, and certain infections can cause secondary pulmonary alveolar proteinosi...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.rafaldb.com/papers/A-2006-09-Szeged-Nanobiophysics-oxide-and-sulfide-crystals-in-bacteria.pdf"> <span id="translatedtitle">Magnetic microstructures of chains and clusters of <span class="hlt">iron</span> <span class="hlt">oxide</span> and sulfide nanocrystals in bacteria</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Magnetic microstructures of chains and clusters of <span class="hlt">iron</span> <span class="hlt">oxide</span> and sulfide nanocrystals in bacteria of intracellular ferrimagnetic magnetite (Fe3O4) and greigite (Fe3S4) nanocrystals inside magnetotactic bacteria</p> <div class="credits"> <p class="dwt_author">Dunin-Borkowski, Rafal E.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=280796"> <span id="translatedtitle">Eco-Friendly Magnetic <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Pillared Montmorillonite for Advanced Catalytic Degradation of Dichlorophenol</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">Eco-friendly pillared montmorillonites, in which the pillars consist of <span class="hlt">iron</span> <span class="hlt">oxide</span> are expected to have interesting and unusual magnetic properties that are applicable for environmental decontamination. Completely ?green? and effective composite was synthesized using mild reactio...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=95756"> <span id="translatedtitle"><span class="hlt">OXIDATION</span> OF CYCLOHEXANE WITH AIR CATALYZED BY A STERICALLY HINDERED <span class="hlt">IRON</span> (II) COMPLEX</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary"><span class="hlt">Oxidation</span> of Cyclohexane with Air Catalyzed by a Sterically Hindered <span class="hlt">Iron</span>(II) Complex. Thomas M. Becker, Michael A. Gonzalez* United States Environmental Protection Agency; National Risk Management Research Laboratory; Sustainable Technology Division; Clean Pr...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20748643"> <span id="translatedtitle">Identification of <span class="hlt">iron</span> <span class="hlt">oxide</span> impurities in earliest industrial-scale processed platinum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A detailed investigation of <span class="hlt">iron</span> <span class="hlt">oxide</span> inclusions in a 19th century Russian platinum coin is presented. Such coins represent the products of the first industrial-scale purification of platinum metal. The processed metal is far from pure, however, and two types of <span class="hlt">iron</span> <span class="hlt">oxide</span> inclusions are identified by electron microprobe and Raman microscopy. The results show that the inclusions mainly consist of magnetite and haematite. The Raman band of magnetite at 668 cm{sup -1} was found to shift to about 680 cm{sup -1} with an increase in the average <span class="hlt">oxidation</span> state of the <span class="hlt">iron</span>. It is concluded that the <span class="hlt">iron</span> <span class="hlt">oxides</span> are formed during the heating of the platinum metal powder in the manufacturing process.</p> <div class="credits"> <p class="dwt_author">Weerd, Jaap van der [Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Rehren, Thilo [Institute of Archaeology, University College London, 31-34 Gordon Square, London WC1H 0PY (United Kingdom)]. E-mail: th.rehren@ucl.ac.uk; Firth, Steven [Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Clark, Robin J.H. [Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)]. E-mail: r.j.h.clark@ucl.ac.uk</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-09-15</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return 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href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a style="font-weight: bold;">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_17");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://dspace.mit.edu/handle/1721.1/91255"> <span id="translatedtitle">Lipidoid-Coated <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoparticles for Efficient DNA and siRNA delivery</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">The safe, targeted and effective delivery of gene therapeutics remains a significant barrier to their broad clinical application. Here we develop a magnetic nucleic acid delivery system composed of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles ...</p> <div class="credits"> <p class="dwt_author">Jiang, Shan</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41335884"> <span id="translatedtitle">A cheaper, faster, better way to detect water of <span class="hlt">hydration</span> on Solar System bodies</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The 3.0-micrometers water of <span class="hlt">hydration</span> absorption feature observed in the IR photometry of many low-albedo and some medium-albedo asteroids strongly correlates with the 0.7-micrometers Fe(+2) to Fe(+3) <span class="hlt">oxidized</span> <span class="hlt">iron</span> absorption feature observed in narrowband spectrophotometry of these asteroids. Using this relationship, an empirical algorithm for predicting the presence of water of <span class="hlt">hydration</span> in the surface material of a Solar System</p> <div class="credits"> <p class="dwt_author">Faith Vilas</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24486913"> <span id="translatedtitle">Synthesis and characterization of CREKA-conjugated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles for hyperthermia applications.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">One of the current challenges in the systemic delivery of nanoparticles in cancer therapy applications is the lack of effective tumor localization. <span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles (IONPs) coated with crosslinked dextran were functionalized with the tumor-homing peptide CREKA, which binds to fibrinogen complexes in the extracellular matrix of tumors. This allows for the homing of these nanoparticles to tumor tissue. The IONP core allows for particle heating upon exposure to an alternating magnetic field (AMF), while the dextran coating stabilizes the particles in suspension and decreases the cytotoxicity of the system. Magnetically mediated hyperthermia (MMH) allows for the heating of tumor tissue to increase the efficacy of traditional cancer treatments using IONPs. While MMH provides the opportunity for localized heating, this method is currently limited by the lack of particle penetration into tumor tissue, even after effective targeted delivery to the tumor site. The CREKA-conjugated nanoparticles presented were characterized for their size, stability, heating capabilities and biocompatibility. The particles had a <span class="hlt">hydrated</span> diameter of 52nm, were stable in phosphate buffered saline solution and media with 10% v/v fetal bovine serum over at least 12h, and generated enough heat to raise solution temperatures well into the hyperthermia range (41-45°C) when exposed to an AMF, owing to an average specific absorption rate of 83.5Wg(-1). Cytotoxicity studies demonstrated that the particles have low cytotoxicity over long exposure times at low concentrations. A fibrinogen clotting assay was used to determine the binding affinity of CREKA-conjugated particles, which was significantly greater than the binding affinity of dextran, only coated IONPs demonstrating the potential for this particle system to effectively home to a variety of tumor locations. Finally, it was shown that in vitro MMH increased the effects of cisplatin compared with cisplatin or MMH treatments alone. PMID:24486913</p> <div class="credits"> <p class="dwt_author">Kruse, Anastasia M; Meenach, Samantha A; Anderson, Kimberly W; Hilt, J Zach</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.geosciences.unl.edu/~dloope/pdf/RindedIronSedimentology.pdf"> <span id="translatedtitle">Rinded <span class="hlt">iron-oxide</span> concretions: hallmarks of altered siderite masses of both early and late diagenetic origin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Rinded <span class="hlt">iron-oxide</span> concretions: hallmarks of altered siderite masses of both early and late-0118, USA Associate Editor ­ Peter Talling ABSTRACT <span class="hlt">Iron</span>-bearing concretions are valuable records later diagenetic events. Distinctive concretions composed of heavy rinds of <span class="hlt">iron</span> <span class="hlt">oxide</span> that surround</p> <div class="credits"> <p class="dwt_author">Nebraska-Lincoln, University of</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005PhDT.......338S"> <span id="translatedtitle">The role of volatiles in the reduction of <span class="hlt">iron</span> <span class="hlt">oxides</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">With <span class="hlt">iron</span> ore reduction processes using coal-ore pellets or mixtures, it is possible that volatiles from the coals can contribute to the overall reduction. By identifying the possible reducing species in the volatiles as H2/CO and simulating these constituents, the rates for H2 and CO were investigated in the temperature and reduction range of interest where hydrogen was the major reductant and studied in detail. In the initial stages of the present study, the fundamentals of hydrogen reduction of fine powder were found to be a complex mechanism of chemical kinetics and mass transfer. Complete uniform reduction for porous and dense <span class="hlt">iron</span> ores were not observed contrary to existing work regarding this subject. Morphological observations of <span class="hlt">iron</span> ores reduced at low and high temperatures showed a topochemical receding interface to be dominating with an intermediate region developing for higher temperature samples indicating the importance of pore mass transfer at the later stages of reduction. Although the activation energy of 50˜56 kJ/mole for these powder samples were comparable to the literature values for solely chemical kinetics controlled reactions, the reaction rates were not proportional to sample weight and also did not exhibit complete uniform internal reduction. The calculated mass transfer rates were comparable to the observed rate which suggested that bulk mass transfer is important to the mixed-control. The reaction rate at the mixed control regime was found to be first order with respect to hydrogen partial pressure. Results of reducing <span class="hlt">iron</span> <span class="hlt">oxide</span> powders in a mixture of He-40%H2 -5%CO and H2-1%H2S showed that H2S and CO which is involved with the volatiles does not affect the rate at the reduction range of interest indicating the role of volatiles is dominated by the hydrogen reduction. The single composite pellet experiments at 900 and 1000°C showed significant fixed carbon reduction to occur above 1000°C. Depending upon the type of carbon reductant in the composite pellet, secondary reactions with carbon and H2O was possible. Sintering of the pellets did not occur until a significant amount of reduction was obtained and thus for volatile reduction it is likely that the effects of sintering was negligible. To determine the possibility of volatile reduction, a layer of Fe 2O3 powders were spread over HV coals resulting in the reduction of the top layer by about 20% at 1000°C after 1000 seconds. The morphology of the reduced Fe2O3 layer indicated that the reduction is higher near the interface of Coal/Fe2O3. The volatile reduction of a single layer of composite pellet was found to be negligible. However, the reduction of Fe2O3 pellets at the top layer by the volatiles from the bottom layers of a three-layer pellet geometry was observed to be about 15%. From the morphological observations and the computed rates of bulk mass transfer, volatile reduction seems to be controlled by a mixed-controlled mechanism of bulk mass transfer and the limited-mixed control. Using the reduction information obtained from the single pellet experiments reduced in hydrogen, an empirical relationship was obtained to approximately predict the amount of volatile reduction up to 20%.</p> <div class="credits"> <p class="dwt_author">Sohn, Il</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002AGUFM.B72A0756C"> <span id="translatedtitle">Microbial Communities Associated with Biogenic <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Mineralization in Circumneutral pH Environments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Lithotrophic growth on <span class="hlt">iron</span> is a metabolism that has been found in a variety of neutral pH environments and is likely important in sustaining life in microaerophilic solutions, especially those low in organics. The composition of the microbial communities, especially the organisms that are responsible for <span class="hlt">iron</span> <span class="hlt">oxidation</span>, and carbon and nitrogen fixation, are not known, yet the ability to recognize these contributions is vital to our understanding of <span class="hlt">iron</span> cycling in natural environments. Our approach has been to study the microbial community structure, mineralogy, and geochemistry of ~20 cm thick, 100's meters long, fluffy <span class="hlt">iron</span> <span class="hlt">oxide</span>-encrusted biological mats growing in the Piquette Mine tunnel, and to compare the results to those from geochemically similar environments. In situ measurements (Hydrolab) and geochemical characterization of bulk water samples and peepers (dialysis sampling vials) indicate that the environment is microaerobic, with micromolar levels of <span class="hlt">iron</span>, high carbonate and sulfate, and typical groundwater nitrate and nitrite concentrations. 16S rDNA clone libraries show that the microbial mat and water contain communities with considerable diversity within the Bacterial domain, a large proportion of Nitrospira and Betaproteobacteria, and no Archaea. Because clone library data are not necessarily indicative of actual abundance, fluorescence in-situ hybridization (FISH) was performed on water, mat, and sediment samples from the Piquette mine and two circumneutral <span class="hlt">iron</span>- and carbonate-rich springs in the Oregon Cascade Range. Domain- and phylum-level probes were chosen based on the clone library results (Nitrospira, Beta- and Gammaproteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Planctomyces). FISH data reveal spatial associations between specific microbial groups and mineralized structures. The organisms responsible for making the mineralized sheaths that compose the bulk of the <span class="hlt">iron</span> <span class="hlt">oxide</span> mat are Betaproteobacteria (probably Leptothrix spp.). However, only a small proportion of the cells in the mat reside within the sheaths. Most are located on or around the sheaths, which provide a physical framework for the community. Preliminary results from FISH experiments on the <span class="hlt">iron</span>-rich spring samples show some similarities, including an abundance of Betaproteobacteria. Enrichment and isolation experiments are being performed to identify the <span class="hlt">iron-oxidizing</span> organisms. <span class="hlt">Iron-oxidizers</span> have been enriched from all sites. In some cultures it has been difficult to isolate the <span class="hlt">iron-oxidizing</span> organisms from a non-<span class="hlt">iron-oxidizing</span> heterotroph, possibly indicating co-dependence. Knowledge of the microbial community structure and the metabolic activities of key members will enable us to better understand the processes and chemical conditions which generate <span class="hlt">iron</span> <span class="hlt">oxide</span> deposits found in the geologic record on Earth and possibly extraterrestrial habitats.</p> <div class="credits"> <p class="dwt_author">Chan, C. S.; Banfield, J. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40678708"> <span id="translatedtitle">Enhancing Fenton <span class="hlt">oxidation</span> of TNT and RDX through pretreatment with zero-valent <span class="hlt">iron</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The effect of reductive treatment with elemental <span class="hlt">iron</span> on the rate and extent of TOC removal by Fenton <span class="hlt">oxidation</span> was studied for the explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) using a completely stirred tank reactor (CSTR). The results support the hypothesis that TNT and RDX are reduced with elemental <span class="hlt">iron</span> to products that are <span class="hlt">oxidized</span> more rapidly and completely by</p> <div class="credits"> <p class="dwt_author">Seok-Young Oh; Pei C. Chiu; Byung J. Kim; Daniel K. Cha</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49179387"> <span id="translatedtitle">Cytotoxic effects of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles and implications for safety in cell labelling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The in vitro labelling of cultured cells with <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (NPs) is a frequent practice in biomedical research. To date, the potential cytotoxicity of these particles remains an issue of debate. In the present study, 4 different NP types (dextran-coated Endorem, carboxydextran-coated Resovist, lipid-coated magnetoliposomes (MLs) and citrate-coated very small <span class="hlt">iron</span> <span class="hlt">oxide</span> particles (VSOP)) are tested on a variety</p> <div class="credits"> <p class="dwt_author">Stefaan J. H. Soenen; Uwe Himmelreich; Nele Nuytten; Marcel De Cuyper</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://repository.tamu.edu/handle/1969.1/ETD-TAMU-1977-THESIS-S391"> <span id="translatedtitle">High gradient magnetic separation of <span class="hlt">iron</span> <span class="hlt">oxide</span> minerals from soil clays</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">HIGH GRADIENT MAGNETIC SEPARATION OF <span class="hlt">IRON</span> <span class="hlt">OXIDE</span> MINERALS FROM SOIL CLAYS A Thesis by DARRELL GENE SCHULZE Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1977 Major Subject: Soil Science HIGH GRADIENT MAGNETIC SEPARATION OF <span class="hlt">IRON</span> <span class="hlt">OXIDE</span> MINERALS FROM SOIL CLAYS A Thesis DARRELL GENE SCHULZE Approved as to style and content by: (Chairman of C ittee) epartm t) j (Member) (Membe December 1977...</p> <div class="credits"> <p class="dwt_author">Schulze, Darrell Gene</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-07</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011PhyB..406.1496G"> <span id="translatedtitle">Correlation between structural and magnetic properties of sprayed <span class="hlt">iron</span> <span class="hlt">oxide</span> thin films</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The structural, optical and magnetic properties of <span class="hlt">iron</span> <span class="hlt">oxide</span> films were investigated. Raman spectroscopy results demonstrate that different <span class="hlt">iron</span> <span class="hlt">oxide</span> polymorphs can coexist in the sprayed films. It also showed that thickness plays an important role in the development of mixed or pure hematite films. Among the phases detected in the films are feroxyhyte and maghemite. Additionally, the control of the magnetic properties by varying the deposition temperature and thickness is established in this work.</p> <div class="credits"> <p class="dwt_author">Garcia-Lobato, M. A.; Martinez, Arturo I.; Castro-Roman, M.; Falcony, C.; Escobar-Alarcon, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40926841"> <span id="translatedtitle">Gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> associations under supergene conditions: An experimental approach</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">-The interaction of gold hydroxo-chloro complexes with <span class="hlt">iron</span> <span class="hlt">oxides</span> (ferrihydrites, goethites) during coprecipitation experiments is investigated. Chemical analyses of solids and solutions are coupled with a detailed characterization of the <span class="hlt">iron</span> <span class="hlt">oxides</span> with various methods, including X-ray diffraction, High Resolution Transmission Electron Microscopy (HRTEM), and Mössbauer spectroscopy. HCl solutions containing varying amounts of AuCl4- and ferric nitrate were titrated to</p> <div class="credits"> <p class="dwt_author">Catherine Greffié; Marc F. Benedetti; Claude Parron; Marc Amouric</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040089060&hterms=chemiluminescence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dchemiluminescence"> <span id="translatedtitle">Luminescence and ESR studies of relationships between O(-)-centres and structural <span class="hlt">iron</span> in natural and synthetically <span class="hlt">hydrated</span> kaolinites</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Luminescence, induced by dehydration and by wetting with hydrazine and unsymmetrically substituted hydrazine, and related ESR spectra have been observed from several kaolinites, synthetically <span class="hlt">hydrated</span> kaolinites, and metahalloysites. The amine-wetting luminescence results suggest that intercalation, not a chemiluminescence reaction, is the luminescence trigger. Correlation between <span class="hlt">hydration</span>-induced luminescence and g = 2 ESR signals associated with O(-)-centres in several natural halloysites, and concurrent diminution of the intensity of both these signal types as a function of aging in two 8.4 angstroms synthetically <span class="hlt">hydrated</span>, kaolinites, confirm a previously-reported relationship between the luminescence induced by dehydration and in the presence of O(-)-centres (holes, i.e., electron vacancies) in the tetrahedral sheet. Furthermore, the ESR spectra of the 8.4 angstroms <span class="hlt">hydrate</span> showed a concurrent change in the line shape of the g = 4 signal from a shape usually associated with structural Fe in an ordered kaolinite, to a simpler one typically observed in more disordered kaolinite, halloysite, and montmorillonite. Either structural Fe centres and the O(-)-centres interact, or both are subject to factors previously associated with degree of order. The results question the long-term stability of the 8.4 angstroms <span class="hlt">hydrate</span>, although XRD does not indicate interlayer collapse over this period. Complex inter-relationships are shown between intercalation, stored energy, structural Fe, and the degree of <span class="hlt">hydration</span> which may be reflected in catalytic as well as spectroscopic properties of the clays.</p> <div class="credits"> <p class="dwt_author">Coyne, L. M.; Costanzo, P. M.; Theng, B. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004JVST...22..419C"> <span id="translatedtitle">Fabrication of <span class="hlt">iron</span> (III) <span class="hlt">oxide</span> doped polystyrene shells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A type of <span class="hlt">iron</span> (III) <span class="hlt">oxide</span> doped plastic shell used for inertial confinement fusion experiments has been fabricated by emulsion techniques. Three different phases of solution (W1, O, and W2) are used for the fabrication process. The W1 phase is a 1 wt % of sodium lauryl sulfate in water. This W1 phase solution is mixed with a 3 wt % Fe2O3-polystyrene (PS) solution in benzene-dichloroethane (O phase) while stirring. The resulting emulsion (W1/O) is poured into a 3 wt % aqueous polyvinyl alcohol solution (W2 phase) while stirring. The resulting emulsion (W1/O/W2) is then heated to evaporate benzene and dichloroethane, and thus a solid Fe2O3-PS shell is formed. The diameter and wall thickness of the shells range from 150 to 500 ?m and 5 to 15 ?m, respectively. The average surface roughness of the shells is 40 nm, similar to that of the usual PS shells. .</p> <div class="credits"> <p class="dwt_author">Cai, Pei-Jun; Tang, Yong-Jian; Zhang, Lin; Du, Kai; Feng, Chang-Gen</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23802405"> <span id="translatedtitle">Functionalization of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with biosurfactants and biocompatibility studies.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We present methodologies to functionalize <span class="hlt">iron</span> <span class="hlt">oxide</span> (Fe3O4) nanoparticles with biosurfactants and biocompatibility results. Positively charged Fe3O4 nanoparticles of average hydrodynamic size -26 nm is functionalized with four different molecules of interest, viz., surfactin, rhamnolipid, polyethylene glycol (PEG) and dextran. The functionalization results in dramatic alterations in surface potential and hydrodynamic size due to the presence of coated moieties on the nanoparticle interface. The Fourier transform infrared spectroscopy and thermogravimetric analysis confirm the presence of adsorbed moieties on nanoparticles. The phase contrast microscopy studies show the formation of reversible chains of functionalized nanoparticles under an external magnetic field. Cell viability studies using L929 mouse fibroblast cell line show that pure surfactin, rhamnolipid and dextran exhibit cytotoxicity with increase in concentration, whereas, pure PEG exhibit biocompatibility at different concentrations. Accordingly, surfactin and rhamnolipid coated nanoparticles are found to be cytotoxic with increase in concentration and PEG coated nanoparticles are found to be biocompatible. Dextran coated nanoparticles do not exhibit significant increase in biocompatibility. PMID:23802405</p> <div class="credits"> <p class="dwt_author">Sangeetha, J; Thomas, Susha; Arutchelvi, J; Doble, Mukesh; Philip, John</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013MMTB..tmp..227D"> <span id="translatedtitle">Hydrogen Reduction of Zinc and <span class="hlt">Iron</span> <span class="hlt">Oxides</span> Containing Mixtures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Zinc is a metal of significant technological importance and its production from secondary sources has motivated the development of alternative processes, such as the chemical treatment of electrical arc furnace (EAF) dust. Currently, the extraction of zinc from the mentioned residue using a carbon-containing reducing agent is in the process of being established commercially and technically. In the current study, the possibility of reducing zinc from an EAF dust sample through a H2 constant flux in a horizontal oven is studied. The reduction of a synthetic <span class="hlt">oxide</span> mixture of analogous composition is also investigated. The results indicated that the reduction process is thermodynamically viable for temperatures higher than 1123 K (850 °C), and all zinc metal produced is transferred to the gas stream, enabling its complete separation from <span class="hlt">iron</span>. The same reaction in the presence of zinc crystals was considered for synthesizing FeZn alloys. However, for the experimental conditions employed, although ZnO reduction was indeed thermodynamically hindered because of the presence of zinc crystals (the metal's partial pressure was enhanced), the zinc metal's escape within the gaseous phase could not be effectively avoided.</p> <div class="credits"> <p class="dwt_author">de Siqueira, Rogério Navarro C.; de Albuquerque Brocchi, Eduardo; de Oliveira, Pamela Fernandes; Motta, Marcelo Senna</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JAP...113l4701O"> <span id="translatedtitle">Magnetic resonance imaging of microvessels using <span class="hlt">iron-oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The visualization of microstructures including blood vessels with an inner overall cross-sectional area below approximately 200 ?m remains beyond the capabilities of current clinical imaging modalities. But with magnetic resonance (MR) imaging, magnetic entities cause susceptibility artifacts in the images by disrupting the homogeneous magnetic field in a much larger scale than their actual size. As validated in this paper through simulation and in-vitro experiments, these artifacts can serve as a source of contrast, enabling microvessels with an inner diameter below the spatial resolution of any medical imaging modalities to be visualized using a clinical MR scanner. For such experiments, micron-sized agglomerations of <span class="hlt">iron-oxide</span> (Fe3O4) nanoparticles were injected in microchannels with internal diameters of 200 and 50 ?m equivalent to a narrower artery or a larger arteriole, and down to a smaller arteriole, respectively. The results show the feasibility of the proposed method for micro-particle detection and the visualization of microvessels using a 1.5 T clinical MR scanner. It was confirmed that the method is reproducible and accurate at the sub-pixel level.</p> <div class="credits"> <p class="dwt_author">Olamaei, N.; Cheriet, F.; Martel, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1997HyInt.110...33F"> <span id="translatedtitle">Mg-rich <span class="hlt">iron</span> <span class="hlt">oxide</span> spinels from tuffite</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Powdered crystals of an <span class="hlt">iron</span>-rich spinel separated from tuffite were examined by chemical analysis, X-ray diffractometry (XRD), magnetometry, scanning electron microscopy and Mössbauer spectroscopy. They are found to contain mainly 48 mass% Fe2O3; 16.9% FeO; 14.3% TiO2; 9% MgO and 3% Al2O3. The magnetization is 29 J T-1 kg-1 at B0 ~ 0.9 T. XRD pattern reveals two cubic phases with ?0 = 0.8382(5) and 0.8412(5) nm, respectively. Mössbauer spectra are very complex, but the hyperfine field distribution patterns can be decomposed in two relatively well-resolved Gaussian distributions for the Fe3+ block (averaged isomer shift relative to ?-Fe, ? = 0.27 mm s-1) with Bhf = 43.6 T (14.6% of the whole spectral area, WSA) and Bhf = 47.3 (27.7% WSA). A second less resolved distribution block (? = 0.63 mm s-1) shows two main maxima in the P(Bhf) curve at 35.3 T (25.7% WSA) and 45.2 T (19.7% WSA), respectively. The Mg-rich maghemite (lower ?0) appears to be a direct alteration product of a Mg-rich magnetite (higher ?0), via an <span class="hlt">oxidation</span> process of structural Fe2+ to Fe3+ proceeding from the outer to the inner part of the crystal.</p> <div class="credits"> <p class="dwt_author">Fabris, J. D.; Mussel, W. Da N.; Coey, J. M. D.; de Jesus Filho, M. F.; Goulart, A. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1990PhDT.......129K"> <span id="translatedtitle">Inverse-Photoemission Spectroscopy of <span class="hlt">Iron</span> <span class="hlt">Oxides</span>, Silver</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">I measured the inverse-photoemission spectra (IPES) of <span class="hlt">iron</span> <span class="hlt">oxides</span> grown on an Fe substrate, and calculated the band structure of paramagnetic FeO to analyze the IPES. The band calculation showed some overlap between Fe _3_{rm d} states and O_2_{rm p} states in the region of occupied states, and s,p-like states of Fe in the unoccupied region. Isochromatic IPES showed structures at ~2.5 eV and ~7.5 eV above the Fermi energy. I estimate the full band gap of FeO as 2.5 eV from the IPES data. Angle-resolved inverse-photoemission spectra (ARIPES) have been measured on single-crystal Ag. The results are compared with the predictions of bulk band-structure theory and a free-electron model. The latter gives good agreement for the structure with a final state near the Fermi energy. Band theory is needed for the structure 17 eV above the Fermi energy. This structure is very nondispersive, indicating the existence of a very flat band throughout the IXUL plane.</p> <div class="credits"> <p class="dwt_author">Kim, Bongsoo</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005PhDT.........6I"> <span id="translatedtitle">Synthesis of p-<span class="hlt">iron</span>(III) <span class="hlt">oxide</span>, n-<span class="hlt">iron</span>(III) <span class="hlt">oxide</span>, and carbon-modified-n-titanium dioxide and their application in self-driven photoelectrochemical cells: p-<span class="hlt">iron</span>(III) <span class="hlt">oxide/n-iron</span>(III) <span class="hlt">oxide</span>, p-<span class="hlt">iron</span>(III) <span class="hlt">oxide</span>/carbon-modified-n-titanium dioxide, and p-gallium indium phosphide/carbon-modified-n-titanium dioxide for direct water photoelectrolysis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">My Ph.D. Dissertation describes (1) the influence of metal dopants on the spray pyrolytic synthesis of p-type and n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> thin film semiconductors, (2) the fabrication of carbon-modified (CM) n-type titanium dioxide, and (3) various self-driven photoelectrochemical cells (PEC) for water splitting. (1) Stable thin films of <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> was the first goal pursued in this work. Various metal dopants were investigated to ascertain their viability as good dopant for <span class="hlt">iron</span>(III) <span class="hlt">oxide</span>. These metals included copper, zinc, and magnesium. This was followed by investigating metals that could improve the conductivity of n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span>, which included indium, iodine, manganese, and calcium. Research showed that zinc improved p-type characteristics the best, and considerably improved stability of p-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> in acidic media. Indium-doped n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> showed improvement in photocurrent response over naturally-doped <span class="hlt">iron</span>(III) <span class="hlt">oxide</span>; however, there was a loss in the onset potential, which proved vital for developing a self-driven PEC. Importantly, the use of 1-pentanol as the spray solution solvent instead of ethanol improved the onset potential and photoresponse of n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> which helped to fabricate a self-driven p-type/n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> PEC for water splitting. (2) Carbon-modified n-type titanium dioxide electrodes were found to be extremely valuable towards fabrication of self-driven water splitting PEC, because the addition of carbon into the titanium dioxide crystal structure provided it with the ability to absorb light much further into the visible spectrum. Unmodified titanium dioxide can only absorb ˜13% of the total solar power (100 mW/cubic cm) of Air Mass (AM) 1.5; in other words wavelengths of light from ultraviolet to 414 nm. Carbon modification of n-type titanium dioxide allows it to absorb up to 535 nm, or ˜30% of the total solar power. (3) The most important part of this work is the fabrication of a self-driven PEC for water splitting using zinc-doped p-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span> and naturally-doped n-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span>; carbon-modified n-type titanium dioxide and zinc-doped p-type <span class="hlt">iron</span>(III) <span class="hlt">oxide</span>; and p-type gallium indium phosphide and carbon-modified n-type titanium dioxide.</p> <div class="credits"> <p class="dwt_author">Ingler, William B., Jr.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10902578"> <span id="translatedtitle">Ferritin <span class="hlt">oxidation</span> in vitro: implication of <span class="hlt">iron</span> release and degradation by the 20S proteasome.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Ferritin, the major <span class="hlt">iron</span> storage protein in mammalian cells, was treated with various concentrations of different <span class="hlt">oxidants</span>: xanthine/xanthine oxidase, Sin-1 (3-morpholinosydnonimine, purchased from Alexis, Grunberg, Germany), DEA-NO (Diethylamine NONOate, purchased from Calblochem-Novabiochem, Schwalbach, Germany), and hydrogen peroxide. The proteolytic susceptibility towards the isolated 20S proteasome of untreated ferritin and <span class="hlt">oxidized</span> ferritin was measured in parallel with the <span class="hlt">iron</span> liberated by these <span class="hlt">oxidants</span>. With increasing hydrogen peroxide, Sin-1, and xanthine oxidase concentrations, the measured proteasomal degradation of ferritin also increased. At higher <span class="hlt">oxidant</span> concentrations, however, the proteolytic susceptibility began to decrease. The <span class="hlt">oxidation</span> of ferritin by DEA-NO was accompanied by a lesser increase of proteolytic susceptibility in comparison with the effects of the other <span class="hlt">oxidants</span>. Addition of DEA-NO to Sin-1 suppressed the increase in proteolytic susceptibility of ferritin, whereas adding xanthine/xanthine oxidase had no additional effect. <span class="hlt">Iron</span> was liberated readily from ferritin as a result of the <span class="hlt">oxidation</span> process, although the increase in proteolytic susceptibility was not always correlated to the <span class="hlt">iron</span> release. In fact, the degradation of <span class="hlt">oxidatively</span> damaged ferritin was not accompanied by a further increase of free <span class="hlt">iron</span>. Therefore, we conclude that the proteasome is a secondary antioxidative defense system that degrades only nonfunctional ferritin. PMID:10902578</p> <div class="credits"> <p class="dwt_author">Rudeck, M; Volk, T; Sitte, N; Grune, T</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-05-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a 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href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a style="font-weight: bold;">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_18");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25427555"> <span id="translatedtitle"><span class="hlt">Hydration</span> kinetics, ion-release and antimicrobial properties of white Portland cement blended with zirconium <span class="hlt">oxide</span> nanoparticles.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This study examines the impact of 20 wt% zirconium <span class="hlt">oxide</span> nanoparticles on the early <span class="hlt">hydration</span> kinetics of white Portland cement by isothermal conduction calorimetry and transmission electron microscopy. The findings confirm that the nano-ZrO2 particles do not directly participate in the chemical reactions during cement <span class="hlt">hydration</span>; although, they do divert the normal <span class="hlt">hydration</span> processes and accelerate the initial setting reactions. The rate of heat evolution and the extent of the exotherm associated with these reactions are reduced in the presence of nano-ZrO2. The incorporation of nano-ZrO2 into the cement also decreases the solubility of the silicate phases but does not compromise its capacity to release hydroxide ions. There was no observed difference in the antimicrobial activity of the nano-ZrO2-blended and unblended cement pastes against S. aureus and E. coli; however, a modest reduction in this property was noted against P. aeruginosa for the blended cement. PMID:25427555</p> <div class="credits"> <p class="dwt_author">Li, Qiu; Coleman, Nichola J</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/665932"> <span id="translatedtitle">The crystal chemistry and structural analysis of uranium <span class="hlt">oxide</span> <span class="hlt">hydrates</span>. Final report, May 15, 1995--December 31, 1997</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The purpose of this research program was to develop a thorough understanding of the crystal-chemical and crystal-structural systematics of uranyl <span class="hlt">oxide</span> <span class="hlt">hydrates</span> which are the initial corrosion products of the UO{sub 2} in spent nuclear fuel and the principal phases in which actinides occur in the near surface environment. The scope of this program has been expanded to include all inorganic phases in which U{sup 6+} plays a significant structural role; currently 183 phases with known crystal structures.</p> <div class="credits"> <p class="dwt_author">Miller, M.L.; Ewing, R.C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22304546"> <span id="translatedtitle">Vapour phase approach for <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle synthesis from solid precursors</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A new non-solution mediated approach to the synthesis of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles directly from solid FeCl{sub 2} salt precursors has been developed. The method is rapid, simple and scalable. The structural properties and the phase of the resulting <span class="hlt">iron</span> <span class="hlt">oxide</span> particles has been determined by a range of methods including XRD, FT-IR and Mössbauer spectroscopy, and the phase is shown to be maghemite (?-Fe{sub 2}O{sub 3}). The magnetic properties of the <span class="hlt">iron</span> <span class="hlt">oxide</span> particles have been measured using SQUID, confirming superparamagnetic behaviour of the powder and a saturation magnetization of 53.0 emu g{sup ?1} at 300 K. Aqueous dispersions at increasing concentrations were prepared and their heating rate under a 400 kHz alternating magnetic field measured. The specific absorption rate (SAR) of the <span class="hlt">iron</span> <span class="hlt">oxide</span> was found to be 84.8 W g{sup ?1}, which makes the material suitable for the formulation of ferrofluids or ferrogels with RF heating properties. - Graphical Abstract: Superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles obtained by a novel vapour phase approach. Highlights: ? Novel vapour phase (non-solvent) approach for <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle synthesis. ? Attractive alternative approach to the present co-precipitation method. ? Better magnetic properties with high coercivity of nanoparticles. ? A high specific absorption rate (SAR) for hyperthermia applications.</p> <div class="credits"> <p class="dwt_author">Singh, Mandeep; Ulbrich, Pavel; Prokopec, Vadym [Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Svoboda, Pavel [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 120 00 Prague 2 (Czech Republic); Šantavá, Eva [Institute of Physics ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Št?pánek, František, E-mail: Frantisek.Stepanek@vscht.cz [Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10810445"> <span id="translatedtitle">Genetic variation of basal <span class="hlt">iron</span> status, ferritin and <span class="hlt">iron</span> regulatory protein in mice: potential for modulation of <span class="hlt">oxidative</span> stress.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Toxic and carcinogenic free radical processes induced by drugs and other chemicals are probably modulated by the participation of available <span class="hlt">iron</span>. To see whether endogenous <span class="hlt">iron</span> was genetically variable in normal mice, the common strains C57BL/10ScSn, C57BL/6J, BALB/c, DBA/2, and SWR were examined for major differences in their hepatic non-heme <span class="hlt">iron</span> contents. Levels in SWR mice were 3- to 5-fold higher than in the two C57BL strains, with intermediate levels in DBA/2 and BALB/c mice. Concentrations in kidney, lung, and especially spleen of SWR mice were also greater than those in C57BL mice. Non-denaturing PAGE of hepatic ferritin from all strains showed a major holoferritin band at approximately 600 kDa, with SWR mice having > 3-fold higher levels than C57BL strains. SDS PAGE showed a band of 22 kDa, mainly representing L-ferritin subunits. A trace of a subunit at 18 kDa was also detected in ferritin from SWR mice. The 18 kDa subunit and a 500 kDa holoferritin from which it originates were observed in all strains after parenteral <span class="hlt">iron</span> overload, and there was no major variation in ferritin patterns. Although <span class="hlt">iron</span> uptake studies showed no evidence for differential duodenal absorption between strains to explain the variation in basal <span class="hlt">iron</span> levels, acquisition of absorbed <span class="hlt">iron</span> by the liver was significantly higher in SWR mice than C57BL/6J. As with <span class="hlt">iron</span> and ferritin contents, total <span class="hlt">iron</span> regulatory protein (IRP-1) binding capacity for mRNA <span class="hlt">iron</span> responsive element (IRE) and actual IRE/IRP binding in the liver were significantly greater in SWR than C57BL/6J mice. Cytosolic aconitase activity, representing unbound IRP-1, tended to be lower in the former strain. SWR mice were more susceptible than C57BL/10ScSn mice to the toxic action of diquat, which is thought to involve <span class="hlt">iron</span> catalysis. If extrapolated to humans, the findings could suggest that some people might have the propensity for greater basal hepatic <span class="hlt">iron</span> stores than others, which might make them more susceptible to <span class="hlt">iron</span>-catalysed toxicity caused by <span class="hlt">oxidants</span>. PMID:10810445</p> <div class="credits"> <p class="dwt_author">Clothier, B; Robinson, S; Akhtar, R A; Francis, J E; Peters, T J; Raja, K; Smith, A G</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010PhDT.......201K"> <span id="translatedtitle">Solar Hydrogen Production by Photo-<span class="hlt">oxidation</span> of Water from Doped <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Photoanodes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Hematite thin film electrodes synthesized as photoanodes for the photoelectrochemical hydrogen production from water. A novel electrochemical method in which the <span class="hlt">iron</span> <span class="hlt">oxide</span> precursors is co-deposited with diverse metals to create electrochemically doped thin films has been studies. The most promising dopant metals that found have been Pt, Mo, Cr, Ti and Al; which are substituted into the hematite structure in 1-8 % atomic. The films were characterized by scanning electron microscopy, X-ray diffraction, UV-Vis optical spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to determine the effect of the dopants on the hematite structure and the photoelectrochemical performance as compared to the undoped material. The IPCE (incident photon-to-current efficiency) values of the transition metal doped <span class="hlt">iron</span> <span class="hlt">oxide</span> were up to 4 times higher than the undoped samples. Further improvements to the photocatalytic performance were achieved by deposition of oxygen evolution catalysts, as well as modifications to the surface of the hematite photoelectrode.</p> <div class="credits"> <p class="dwt_author">Kleiman-Shwarscetin, Alan</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012JMMM..324.3975S"> <span id="translatedtitle">Study of carbon encapsulated <span class="hlt">iron</span> <span class="hlt">oxide/iron</span> carbide nanocomposite for hyperthermia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Magnetic nanocomposite has been synthesized successfully using biopolymer route which acts as a source of carbon for carbide formation. The present approach based on thermal decomposition represents a considerable advance over previous reports that often use high-energy procedures or costly and hazardous precursors. X-ray diffraction, high-resolution transmission electron microscopy and vibrating sample magnetometer have been used to characterize the composites. Multi phase formation is evident from X-ray diffraction in the as-prepared samples. Phase confirmation was further done from M (magnetization) versus T (temperature) curve indicating presence of different phases of carbide along with <span class="hlt">iron</span> <span class="hlt">oxide</span>. TEM study suggests formation of cuboidal shape nanocomposite using two different quenching conditions. Transmission electron microscopy also confirmed the formation of carbon layer in the vicinity of the Fe3O4/Fe3C nanoparticles. The magnetic measurement shows that the composite nanoparticles exhibit a maximum magnetization of 60 emu g-1 at room temperature. Biocompatibility study with three different cell lines (HeLa, MCF-7 and L929) confirms that these nanocomposites are biocompatible. Temperature versus time measurement in an AC field suggests good heating ability of the samples. These investigations indicate that these nanocomposites may be useful for bioapplications, in particular for hyperthermia.</p> <div class="credits"> <p class="dwt_author">Sharma, Madhulika; Mantri, Sanket; Bahadur, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25390073"> <span id="translatedtitle">Size- and composition-dependent radio frequency magnetic permeability of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocrystals.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We investigate the size- and composition-dependent ac magnetic permeability of superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocrystals for radio frequency (RF) applications. The nanocrystals are obtained through high-temperature decomposition synthesis, and their stoichiometry is determined by Mössbauer spectroscopy. Two sets of <span class="hlt">oxides</span> are studied: (a) as-synthesized magnetite-rich and (b) aged maghemite nanocrystals. All nanocrystalline samples are confirmed to be in the superparamagnetic state at room temperature by SQUID magnetometry. Through the one-turn inductor method, the ac magnetic properties of the nanocrystalline <span class="hlt">oxides</span> are characterized. In magnetite-rich <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocrystals, size-dependent magnetic permeability is not observed, while maghemite <span class="hlt">iron</span> <span class="hlt">oxide</span> nanocrystals show clear size dependence. The inductance, resistance, and quality factor of hand-wound inductors with a superparamagnetic composite core are measured. The superparamagnetic nanocrystals are successfully embedded into hand-wound inductors to function as inductor cores. PMID:25390073</p> <div class="credits"> <p class="dwt_author">Yun, Hongseok; Liu, Xiyu; Paik, Taejong; Palanisamy, Duraivelan; Kim, Jungkwun; Vogel, William D; Viescas, Arthur J; Chen, Jun; Papaefthymiou, Georgia C; Kikkawa, James M; Allen, Mark G; Murray, Christopher B</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-12-23</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/44401619"> <span id="translatedtitle">Polymer-<span class="hlt">oxide</span> adhesion: fabrication of a poly(dimethylsiloxane)\\/<span class="hlt">iron</span>(III) <span class="hlt">oxide</span> composite with a high compressive strength</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Poly(dimethylsiloxane)\\/<span class="hlt">iron</span>(III) <span class="hlt">oxide</span> composite powders were obtained by thermal treatment of polymer-<span class="hlt">oxide</span> mixtures. The composites present themselves as free-flowing powders, visually indistinguishable from the pure <span class="hlt">oxide</span>. They are, however, highly hydrophobic and cannot be dispersed in polar solvents. Cylindrical test specimens were obtained by pressing a composite powder and heating it at two different temperatures. Specimens heated at 270 and 300°C</p> <div class="credits"> <p class="dwt_author">Flavio Maron Vichi; Fernando Galembeck</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1044483"> <span id="translatedtitle">Size dependence of inter- and intra-cluster interactions in core-shell <span class="hlt">iron-iron</span> <span class="hlt">oxide</span> nanoclusters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The room temperature magnetic properties of core-shell <span class="hlt">iron-iron</span> <span class="hlt">oxide</span> nanoclusters (NCs) synthesized by a cluster deposition system have been investigated, and their dependence on mean cluster size has been discussed. In this study, the surface/boundary spins of clusters were not frozen and were thermally activated during the measurements. The inter-cluster interactions between clusters and intra-cluster interactions between the <span class="hlt">iron</span> core (ferromagnetic) and <span class="hlt">iron</span> <span class="hlt">oxide</span> shell (ferrimagnetic) have been investigated by field dependent isothermal remanent magnetization and dc demagnetization measurements at room temperature. The Henkel plot and delta M plot support the existence of dipolar inter-cluster interactions which become stronger with the growth of cluster size. The derivative of the initial magnetization curve implies that smaller clusters require less field and time than the bigger ones to overcome various energy barriers before aligning along the field direction. Coercive field and magnetization are also correlated with the interaction parameters. To compare the room temperature magnetic results, one system was studied at low temperature, where exchange coupling at the interface between the <span class="hlt">oxide</span> and metallic phases was observed through bias effect and anisotropy enhancement.</p> <div class="credits"> <p class="dwt_author">Kaur, Maninder; McCloy, John S.; Jiang, Weilin; Yao, Qi; Qiang, You</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25201602"> <span id="translatedtitle">Taurine supplementation reduces <span class="hlt">oxidative</span> stress and protects the liver in an <span class="hlt">iron</span>-overload murine model.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We previously demonstrated that <span class="hlt">iron</span> overload induces liver damage by causing the formation of reactive oxygen species (ROS). Taurine is a potent free radical scavenger that attenuates the damage caused by excessive oxygen free radicals. Therefore, the aim of the present study was to investigate whether taurine could reduce the hepatotoxicity of <span class="hlt">iron</span> overload with regard to ROS production. Mice were intraperitoneally injected with <span class="hlt">iron</span> 5 days/week for 13 weeks to achieve <span class="hlt">iron</span> overload. It was found that <span class="hlt">iron</span> overload resulted in liver dysfunction, increased apoptosis and elevated <span class="hlt">oxidative</span> stress. Taurine supplementation increased liver taurine levels by 40% and led to improved liver function, as well as a reduction in apoptosis, ROS formation and mitochondrial swelling and an attenuation in the loss of the mitochondrial membrane potential. Treatment with taurine mediated a reduction in <span class="hlt">oxidative</span> stress in <span class="hlt">iron</span>?overloaded mice, attenuated liver lipid peroxidation, elevated antioxidant enzyme activities and maintained reduced glutathione levels. These results indicate that taurine reduces <span class="hlt">iron</span>?induced hepatic <span class="hlt">oxidative</span> stress, preserves liver function and inhibits hepatocyte apoptosis. Therefore, taurine may be a potential therapeutic drug to reduce liver damage caused by <span class="hlt">iron</span> overload. PMID:25201602</p> <div class="credits"> <p class="dwt_author">Zhang, Zeyu; Liu, Dan; Yi, Bo; Liao, Zhangping; Tang, Lei; Yin, Dong; He, Ming</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24460948"> <span id="translatedtitle">An inorganic geochemical argument for coupled anaerobic <span class="hlt">oxidation</span> of methane and <span class="hlt">iron</span> reduction in marine sediments.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Here, we present results from sediments collected in the Argentine Basin, a non-steady state depositional marine system characterized by abundant <span class="hlt">oxidized</span> <span class="hlt">iron</span> within methane-rich layers due to sediment reworking followed by rapid deposition. Our comprehensive inorganic data set shows that <span class="hlt">iron</span> reduction in these sulfate and sulfide-depleted sediments is best explained by a microbially mediated process-implicating anaerobic <span class="hlt">oxidation</span> of methane coupled to <span class="hlt">iron</span> reduction (Fe-AOM) as the most likely major mechanism. Although important in many modern marine environments, <span class="hlt">iron</span>-driven AOM may not consume similar amounts of methane compared with sulfate-dependent AOM. Nevertheless, it may have broad impact on the deep biosphere and dominate both <span class="hlt">iron</span> and methane cycling in sulfate-lean marine settings. Fe-AOM might have been particularly relevant in the Archean ocean, >2.5 billion years ago, known for its production and accumulation of <span class="hlt">iron</span> <span class="hlt">oxides</span> (in <span class="hlt">iron</span> formations) in a biosphere likely replete with methane but low in sulfate. Methane at that time was a critical greenhouse gas capable of sustaining a habitable climate under relatively low solar luminosity, and relationships to <span class="hlt">iron</span> cycling may have impacted if not dominated methane loss from the biosphere. PMID:24460948</p> <div class="credits"> <p class="dwt_author">Riedinger, N; Formolo, M J; Lyons, T W; Henkel, S; Beck, A; Kasten, S</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25357230"> <span id="translatedtitle">Stable anode performance of vanadium <span class="hlt">oxide</span> <span class="hlt">hydrate</span> semi-microspheres and their graphene based composite microspheres in sodium-ion batteries.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A simple and versatile method for preparation of new crystalline vanadium <span class="hlt">oxide</span> <span class="hlt">hydrate</span> semi-microspheres is developed via a simple hydrothermal route, which are tested as a novel high-energy anode materials for sodium-ion batteries. The enhancement of electrochemical performance for the vanadium <span class="hlt">oxide</span> <span class="hlt">hydrate</span> electrode is offered by addition of graphene. The graphene-based vanadium <span class="hlt">oxide</span> <span class="hlt">hydrate</span> microsphere composite shows a high discharge capacity of 336.1 mA h g(-1) for the second cycle between a 0.05-3.0 V voltage limit at a discharge current density of 10 mA g(-1). A reversible capacity of 303.1 mA h g(-1) is retained after 20 cycles. PMID:25357230</p> <div class="credits"> <p class="dwt_author">Fei, Hailong; Li, Zhiwei; Feng, Wenjing; Liu, Xin</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ucl.ac.uk/~ucbtdag/Valentini_2012.pdf"> <span id="translatedtitle">Manipulation of in vivo <span class="hlt">iron</span> levels can alter resistance to <span class="hlt">oxidative</span> stress without affecting ageing in the nematode C. elegans</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Manipulation of in vivo <span class="hlt">iron</span> levels can alter resistance to <span class="hlt">oxidative</span> stress without affecting in the nematode Caenorhabditis elegans. Media supplementation with Fe(III) increased free <span class="hlt">iron</span> levels in vivo</p> <div class="credits"> <p class="dwt_author">Gems, David</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23755691"> <span id="translatedtitle">Green method to form <span class="hlt">iron</span> <span class="hlt">oxide</span> nanorods in orange peels for chromium(VI) reduction.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A green method for synthesizing <span class="hlt">iron</span> <span class="hlt">oxide</span> nanorods within orange peel pith has been developed. Orange peel pith functions as both a support and a reducing agent for <span class="hlt">iron</span> ions. The nanorods were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Results of the characterization indicate that <span class="hlt">iron</span> is deposited on the surface of orange peel primarily in the form of <span class="hlt">iron</span>, <span class="hlt">iron</span>(II) <span class="hlt">oxide</span> and magnetite. The nanoparticles grow to form nanorods in the range of 20-40 nm of diameter. The biocomposite was then tested for Cr(VI) reduction and removal from aqueous solutions, exhibiting removals as high as 96% for concentrations of 10 mg/L and 76% for 50 mg/L, which is almost 4 times the removal capacity of orange peel alone. PMID:23755691</p> <div class="credits"> <p class="dwt_author">López-Téllez, G; Balderas-Hernández, P; Barrera-Díaz, C E; Vilchis-Nestor, A R; Roa-Morales, G; Bilyeu, Bryan</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22068318"> <span id="translatedtitle">Redox switching and oxygen evolution at <span class="hlt">oxidized</span> metal and metal <span class="hlt">oxide</span> electrodes: <span class="hlt">iron</span> in base.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Outstanding issues regarding the film formation, redox switching characteristics and the oxygen evolution reaction (OER) electrocatalytic behaviour of multicycled <span class="hlt">iron</span> oxyhydroxide films in aqueous alkaline solution have been revisited. The <span class="hlt">oxide</span> is grown using a repetitive potential multicycling technique, and the mechanism of the latter hydrous <span class="hlt">oxide</span> formation process has been discussed. A duplex layer model of the <span class="hlt">oxide</span>/solution interphase region is proposed. The acid/base behaviour of the hydrous <span class="hlt">oxide</span> and the microdispersed nature of the latter material has been emphasised. The hydrous <span class="hlt">oxide</span> is considered as a porous assembly of interlinked octahedrally coordinated anionic metal oxyhydroxide surfaquo complexes which form an open network structure. The latter contains considerable quantities of water molecules which facilitate hydroxide ion discharge at the metal site during active oxygen evolution, and also charge compensating cations. The dynamics of redox switching has been quantified via analysis of the cyclic voltammetry response as a function of potential sweep rate using the Laviron-Aoki electron hopping diffusion model by analogy with redox polymer modified electrodes. Steady state Tafel plot analysis has been used to elucidate the kinetics and mechanism of oxygen evolution. Tafel slope values of ca. 60 mV dec(-1) and ca. 120 mV dec(-1) are found at low and high overpotentials respectively, whereas the reaction order with respect to hydroxide ion activity changes from ca. 3/2 to ca. 1 as the potential is increased. These observations are rationalised in terms of a kinetic scheme involving Temkin adsorption and the rate determining formation of a physisorbed hydrogen peroxide intermediate on the <span class="hlt">oxide</span> surface. The dual Tafel slope behaviour is ascribed to the potential dependence of the surface coverage of adsorbed intermediates. PMID:22068318</p> <div class="credits"> <p class="dwt_author">Lyons, Michael E G; Doyle, Richard L; Brandon, Michael P</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-28</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4038746"> <span id="translatedtitle">Interactions of proteins with biogenic <span class="hlt">iron</span> oxyhydroxides and a new culturing technique to increase biomass yields of neutrophilic, <span class="hlt">iron-oxidizing</span> bacteria</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Neutrophilic, bacterial <span class="hlt">iron-oxidation</span> remains one of the least understood energy-generating biological reactions to date. One of the reasons it remains under-studied is because there are inherent problems with working with <span class="hlt">iron-oxidizing</span> bacteria (FeOB), including low biomass yields and interference from the <span class="hlt">iron</span> <span class="hlt">oxides</span> in the samples. In an effort to circumvent the problem of low biomass, a new large batch culturing technique was developed. Protein interactions with biogenic <span class="hlt">iron</span> <span class="hlt">oxides</span> were investigated confirming that such interactions are strong. Therefore, a protein extraction method is described to minimize binding of proteins to biogenic <span class="hlt">iron</span> <span class="hlt">oxides</span>. The combination of these two methods results in protein yields that are appropriate for activity assays in gels and for proteomic profiling. PMID:24910632</p> <div class="credits"> <p class="dwt_author">Barco, Roman A.; Edwards, Katrina J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005PNAS..10210472A"> <span id="translatedtitle">Effect of bicarbonate on <span class="hlt">iron</span>-mediated <span class="hlt">oxidation</span> of low-density lipoprotein</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Oxidation</span> of low-density lipoprotein (LDL) may play an important role in atherosclerosis. We studied the effects of bicarbonate/CO2 and phosphate buffer systems on metal ion-catalyzed <span class="hlt">oxidation</span> of LDL to malondialdehyde (MDA) and to protein carbonyl and MetO derivatives. Our results revealed that LDL <span class="hlt">oxidation</span> in mixtures containing free <span class="hlt">iron</span> or heme derivatives was much greater in bicarbonate/CO2 compared with phosphate buffer. However, when copper was substituted for <span class="hlt">iron</span> in these mixtures, the rate of LDL <span class="hlt">oxidation</span> in both buffers was similar. <span class="hlt">Iron</span>-catalyzed <span class="hlt">oxidation</span> of LDL was highly sensitive to inhibition by phosphate. Presence of 0.3-0.5 mM phosphate, characteristic of human serum, led to 30-40% inhibition of LDL <span class="hlt">oxidation</span> in bicarbonate/CO2 buffer. <span class="hlt">Iron</span>-catalyzed <span class="hlt">oxidation</span> of LDL to MDA in phosphate buffer was inhibited by increasing concentrations of albumin (10-200 ?M), whereas MDA formation in bicarbonate/CO2 buffer was stimulated by 10-50 ?M albumin but inhibited by higher concentrations. However, albumin stimulated the <span class="hlt">oxidation</span> of LDL proteins to carbonyl derivatives at all concentrations examined in both buffers. Conversion of LDL to MDA in bicarbonate/CO2 buffer was greatly stimulated by ADP, ATP, and EDTA but only when EDTA was added at a concentration equal to that of <span class="hlt">iron</span>. At higher than stoichiometric concentrations, EDTA prevented <span class="hlt">oxidation</span> of LDL. Results of these studies suggest that interactions between bicarbonate and <span class="hlt">iron</span> or heme derivatives leads to complexes with redox potentials that favor the generation of reactive oxygen species and/or to the generation of highly reactive CO2 anion or bicarbonate radical that facilitates LDL <span class="hlt">oxidation</span>. Freely available online through the PNAS open access option.Abbreviations: LDL, low-density lipoprotein; MDA, malondialdehyde; MetO, methionine sulfoxide.</p> <div class="credits"> <p class="dwt_author">Arai, Hirofumi; Berlett, Barbara S.; Chock, P. Boon; Stadtman, Earl R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/doepatents/biblio/527767"> <span id="translatedtitle">Metal regeneration of <span class="hlt">iron</span> chelates in nitric <span class="hlt">oxide</span> scrubbing</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p class="result-summary">The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate <span class="hlt">iron</span> (II) (CHELATE) by reduction of <span class="hlt">iron</span> (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing <span class="hlt">iron</span> (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free <span class="hlt">iron</span> (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.</p> <div class="credits"> <p class="dwt_author">Chang, S.G.; Littlejohn, D.; Shi, Y.</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-08-19</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22215586"> <span id="translatedtitle">Effect of <span class="hlt">iron</span> <span class="hlt">oxide</span> loading on the phase transformation and physicochemical properties of nanosized mesoporous ZrO{sub 2}</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Highlights: ? Modified preparation method for nanosized <span class="hlt">iron</span> <span class="hlt">oxide</span> supported ZrO{sub 2} catalysts. ? Systematic study of effect of high <span class="hlt">iron</span> <span class="hlt">oxide</span> loading over ZrO{sub 2}. ? Influence of <span class="hlt">iron</span> <span class="hlt">oxide</span> on the stabilization of tetragonal ZrO{sub 2} phase. ? A mesoporous nature of zirconia changed upon changing <span class="hlt">iron</span> <span class="hlt">oxide</span> loading. ? Surface to bulk migration of <span class="hlt">iron</span> <span class="hlt">oxide</span> evidenced by XPS technique. -- Abstract: Mesoporous ZrO{sub 2}-supported <span class="hlt">iron</span> <span class="hlt">oxide</span> materials were prepared with nominal loadings of <span class="hlt">iron</span> <span class="hlt">oxide</span> of 5, 10, 15 and 20 wt.% using a modified co-precipitation method. The physicochemical properties of the catalysts were characterized by thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, Raman spectroscopy, high resolution transmission electron microscopy, N{sub 2} adsorption, X-ray photoelectron spectroscopy and infrared spectroscopy methods. A delay in the ZrO{sub 2} phase transformation as a result of the incorporation of <span class="hlt">iron</span> was determined using TG/DSC measurements. XRD, Raman spectroscopy and HRTEM results revealed that an increase of <span class="hlt">iron</span> <span class="hlt">oxide</span> loading from 5 to 15 wt.% enhanced the transformation of the monoclinic to tetragonal phase. Unexpectedly, 20 wt.% <span class="hlt">iron</span> <span class="hlt">oxide</span> loading was required for complete tetragonal structure stabilization due to the mesoporosity of the ZrO{sub 2} support. <span class="hlt">Iron</span> <span class="hlt">oxide</span> loadings from 5 to 15 wt.% showed an increase in the BET-surface area due to the presence of amorphous <span class="hlt">iron</span> <span class="hlt">oxide</span> on the surface. XPS and FTIR results indicated that increasing the <span class="hlt">iron</span> <span class="hlt">oxide</span> content to 20 wt.% resulted in stabilization of the tetragonal zirconia phase as a result of surface-to-bulk migration and incorporation of Fe{sup 3+} ions in the ZrO{sub 2} lattice.</p> <div class="credits"> <p class="dwt_author">Basahel, S.N. [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia)] [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia); Ali, Tarek T. [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia) [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia); Chemistry Department, Faculty of Science, Sohag University, 82524 Sohag (Egypt); Narasimharao, K. [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia)] [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia); Bagabas, A.A. [Petrochemicals Research Institute (PRI), King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, 11442 Riyadh (Saudi Arabia)] [Petrochemicals Research Institute (PRI), King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, 11442 Riyadh (Saudi Arabia); Mokhtar, M., E-mail: mmokhtar2000@yahoo.com [Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah (Saudi Arabia)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16756375"> <span id="translatedtitle">Inhibition of hemoglobin- and <span class="hlt">iron</span>-promoted <span class="hlt">oxidation</span> in fish microsomes by natural phenolics.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Natural phenolic antioxidants have been tested in hake (Merluccious merluccious) microsomes as inhibitors of lipid <span class="hlt">oxidation</span> promoted by fish muscle prooxidants: hemoglobin (Hb), enzymatic NADH-<span class="hlt">iron</span> and nonenzymatic ascorbate-<span class="hlt">iron</span>. The phenolics selected were as follows: (a) a grape phenolic extract (OW), (b) a fraction (IV) with isolated grape procyanidins with a medium-low degree of polymerization and galloylation percentage, (c) hydroxytyrosol obtained from olive oil byproducts, and (d) a synthetic phenolic antioxidant, propyl gallate. All compounds delayed lipid <span class="hlt">oxidation</span> activated by Hb, enzymatic NADH-<span class="hlt">iron</span>, and nonenzymatic ascorbate-<span class="hlt">iron</span>, excluding hydroxytyrosol that was not an effective antioxidant on <span class="hlt">oxidation</span> promoted by nonenzymatic <span class="hlt">iron</span>. The relative antioxidant efficiency was independent of the prooxidant system, IV > propyl gallate > OW > hydroxytyrosol, and showed a positive correlation with their incorporation into microsomes (p < 0.05). The reducing capacity or ability for donating electrons and the chelating properties may also contribute to the antioxidant activity of phenolics, although these factors were less decisive than their affinity for incorporating into the microsomes. Conversely, the inhibition of Hb <span class="hlt">oxidation</span> by phenolics and their polarity did not seem to play an important role on antioxidant mechanism. These results stressed the importance of incorporating the exogenous antioxidants into the membranes where are located key substances for fish lipid <span class="hlt">oxidation</span> (highly unsaturated phospholipids, <span class="hlt">iron</span>-reducing enzymes, and endogenous alpha-tocopherol). PMID:16756375</p> <div class="credits"> <p class="dwt_author">Pazos, Manuel; Lois, Salomé; Torres, Josep Lluís; Medina, Isabel</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-06-14</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12726912"> <span id="translatedtitle">Intralysosomal <span class="hlt">iron</span>: a major determinant of <span class="hlt">oxidant</span>-induced cell death.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">As a result of continuous digestion of <span class="hlt">iron</span>-containing metalloproteins, the lysosomes within normal cells contain a pool of labile, redox-active, low-molecular-weight <span class="hlt">iron</span>, which may make these organelles particularly susceptible to <span class="hlt">oxidative</span> damage. <span class="hlt">Oxidant</span>-mediated destabilization of lysosomal membranes with release of hydrolytic enzymes into the cell cytoplasm can lead to a cascade of events eventuating in cell death (either apoptotic or necrotic depending on the magnitude of the insult). To assess the importance of the intralysosomal pool of redox-active <span class="hlt">iron</span>, we have temporarily blocked lysosomal digestion by exposing cells to the lysosomotropic alkalinizing agent, ammonium chloride (NH(4)Cl). The consequent increase in lysosomal pH (from ca. 4.5 to > 6) inhibits intralysosomal proteolysis and, hence, the continuous flow of reactive <span class="hlt">iron</span> into this pool. Preincubation of J774 cells with 10 mM NH(4)Cl for 4 h dramatically decreased apoptotic death caused by subsequent exposure to H(2)O(2), and the protection was as great as that afforded by the powerful <span class="hlt">iron</span> chelator, desferrioxamine (which probably localizes predominantly in the lysosomal compartment). Sulfide-silver cytochemical detection of <span class="hlt">iron</span> revealed a pronounced decrease in lysosomal content of redox-active <span class="hlt">iron</span> after NH(4)Cl exposure, probably due to diminished intralysosomal digestion of <span class="hlt">iron</span>-containing material coupled with continuing <span class="hlt">iron</span> export from this organelle. Electron paramagnetic resonance experiments revealed that hydroxyl radical formation, readily detectable in control cells following H(2)O(2) addition, was absent in cells preexposed to 10 mM NH(4)Cl. Thus, the major pool of redox-active, low-molecular-weight <span class="hlt">iron</span> may be located within the lysosomes. In a number of clinical situations, pharmacologic strategies that minimize the amount or reactivity of intralysosomal <span class="hlt">iron</span> should be effective in preventing <span class="hlt">oxidant</span>-induced cell death. PMID:12726912</p> <div class="credits"> <p class="dwt_author">Yu, Zhengquan; Persson, H Lennart; Eaton, John W; Brunk, Ulf T</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-05-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFM.B11E..06K"> <span id="translatedtitle">Light Induced Dissolution of <span class="hlt">Iron</span> <span class="hlt">Oxides</span> in the Presence of Siderophores</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Iron</span> is a micronutrient that is essential for a range of important enzymatic processes in most organisms. <span class="hlt">Iron</span> deficiency is thought to be limiting the primary productivity in marine `High Nutrient Low Chlorophyll' (HNLC) regions which has a significant effect on global carbon cycling. Important <span class="hlt">iron</span> sources in HNLC regions are upwelling and atmospheric dust inputs. However, the <span class="hlt">iron</span> bioavailability from atmospheric dust is limited by the low solubility and slow dissolution kinetics of <span class="hlt">iron</span> bearing minerals. Marine bacteria are known to facilitate weathering reactions by exudation of substances such as low molecular weight organic ligands including siderophores. We investigated if siderophore promoted photoreductive dissolution constitutes an important pathway for increasing the bioavailability of <span class="hlt">iron</span> <span class="hlt">oxides</span>. We used the microbial siderophores aerobactin and desferrioxamine-B (DFO-B). Aerobactin and desferrixoamines are excreted by marine and terrestrial bacteria. Aerobactin is a dihydroxamate siderophore containing the potentially photoreactive group alpha-hydroxy carboxylate. DFO-B is a trihydroxamate siderophore which forms soluble <span class="hlt">iron</span> complexes that are not photoreactive (BARBEAU et al., 2003). Despite the structural differences, both siderophores accelerate <span class="hlt">iron</span> <span class="hlt">oxide</span> dissolution in irradiated suspensions compared to dissolution rates in the dark. This suggests that both siderophores are not involved in a light induced ligand to metal charge transfer reaction, but rather accelerate other photreductive dissolution mechanisms. Similarly it was observed that both ligands accelerate light induced dissolution of <span class="hlt">iron</span> <span class="hlt">oxides</span> in the presence of oxalate as a chromophore. The observations suggest that light induced dissolution of <span class="hlt">iron</span> <span class="hlt">oxides</span> in the presence of siderophores is an important pathway for bacterial <span class="hlt">iron</span> acquisition. However, the formation of Fe(II) by this mechanism may also lead to an increase of the availability of <span class="hlt">iron</span> to phytoplankton that generally does not produce siderophores or take up <span class="hlt">iron</span>(III)siderophore complexes (BARBEAU et al., 2001). References Barbeau K., Rue E. L., Bruland K. W., and Butler A. (2001) Photochemical cycling of <span class="hlt">iron</span> in the surface ocean mediated by microbial <span class="hlt">iron</span>(III)-binding ligands. Nature 413(6854), 409-413. Barbeau K., Rue E. L., Trick C. G., Bruland K. T., and Butler A. (2003) Photochemical reactivity of siderophores produced by marine heterotrophic bacteria and cyanobacteria based on characteristic Fe(III) binding groups. Limnology and Oceanography 48(3), 1069-1078.</p> <div class="credits"> <p class="dwt_author">Kraemer, S. M.; Borer, P.; Sulzberger, B. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=124031"> <span id="translatedtitle">Life at the Energetic Edge: Kinetics of Circumneutral <span class="hlt">Iron</span> <span class="hlt">Oxidation</span> by Lithotrophic <span class="hlt">Iron-Oxidizing</span> Bacteria Isolated from the Wetland-Plant Rhizosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Batch cultures of a lithotrophic Fe(II)-<span class="hlt">oxidizing</span> bacterium, strain BrT, isolated from the rhizosphere of a wetland plant, were grown in bioreactors and used to determine the significance of microbial Fe(II) <span class="hlt">oxidation</span> at circumneutral pH and to identify abiotic variables that affect the partitioning between microbial <span class="hlt">oxidation</span> and chemical <span class="hlt">oxidation</span>. Strain BrT grew only in the presence of an Fe(II) source, with an average doubling time of 25 h. In one set of experiments, Fe(II) <span class="hlt">oxidation</span> rates were measured before and after the cells were poisoned with sodium azide. These experiments indicated that strain BrT accounted for 18 to 53% of the total <span class="hlt">iron</span> <span class="hlt">oxidation</span>, and the average cellular growth yield was 0.70 g of CH2O per mol of Fe(II) <span class="hlt">oxidized</span>. In a second set of experiments, Fe(II) was constantly added to bioreactors inoculated with live cells, killed cells, or no cells. A statistical model fitted to the experimental data demonstrated that metabolic Fe(II) <span class="hlt">oxidation</span> accounted for up to 62% of the total <span class="hlt">oxidation</span>. The total Fe(II) <span class="hlt">oxidation</span> rates in these experiments were strongly limited by the rate of Fe(II) delivery to the system and were also influenced by O2 and total <span class="hlt">iron</span> concentrations. Additionally, the model suggested that the microbes inhibited rates of abiotic Fe(II) <span class="hlt">oxidation</span>, perhaps by binding Fe(II) to bacterial exopolymers. The net effect of strain BrT was to accelerate total <span class="hlt">oxidation</span> rates by up to 18% compared to rates obtained with cell-free treatments. The results suggest that neutrophilic Fe(II)-<span class="hlt">oxidizing</span> bacteria may compete for limited O2 in the rhizosphere and therefore influence other wetland biogeochemical cycles. PMID:12147500</p> <div class="credits"> <p class="dwt_author">Neubauer, Scott C.; Emerson, David; Megonigal, J. Patrick</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22273850"> <span id="translatedtitle">Millimeter wave ferromagnetic resonance in gallium-substituted ?-<span class="hlt">iron</span> <span class="hlt">oxide</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe{sub 12}O{sub 19}) and strontium ferrite (SrFe{sub 12}O{sub 19}), which have natural ferromagnetic resonant frequency range from 40 GHz to 60?GHz. However, the higher frequency range lacks suitable materials that support the higher frequency ferromagnetic resonance. A new series of gallium-substituted ?-<span class="hlt">iron</span> <span class="hlt">oxides</span> (?-Ga{sub x}Fe{sub 2?x}O{sub 3}) are synthesized which have ferromagnetic resonant frequencies appearing over the frequency range 30 GHz–150 GHz. The ?-Ga{sub x}Fe{sub 2?x}O{sub 3} is synthesized by the combination of reverse micelle and sol-gel techniques or the sol-gel method only. The particle sizes are observed to be smaller than 100 nm. In this paper, the free space magneto-optical approach has been employed to study these newly developed ?-Ga{sub x}Fe{sub 2?x}O{sub 3} particles in millimeter waves. This technique enables to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the millimeter wave frequency range from a single set of direct measurements. The transmittance and absorbance spectra of ?-Ga{sub x}Fe{sub 2?x}O{sub 3} are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.</p> <div class="credits"> <p class="dwt_author">Chao, Liu, E-mail: liu.chao@tufts.edu; Afsar, Mohammed N. [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States); Ohkoshi, Shin-ichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-07</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1021991"> <span id="translatedtitle">Mechanisms of <span class="hlt">iron</span> <span class="hlt">oxide</span> transformations in hydrothermal systems.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Coexistence of magnetite and hematite in hydrothermal systems has often been used to constrain the redox potential of fluids, assuming that the redox equilibrium is attained among all minerals and aqueous species. However, as temperature decreases, disequilibrium mineral assemblages may occur due to the slow kinetics of reaction involving the minerals and fluids. In this study, we conducted a series of experiments in which hematite or magnetite was reacted with an acidic solution under H2-rich hydrothermal conditions (T = 100 250 C,) to investigate the kinetics of redox and non-redox transformations between hematite and magnetite, and the mechanisms of <span class="hlt">iron</span> <span class="hlt">oxide</span> transformation under hydrothermal conditions. The formation of euhedral crystals of hematite in 150 and 200 C experiments, in which magnetite was used as the starting material, indicates that non-redox transformation of magnetite to hematite occurred within 24 h. The chemical composition of the experimental solutions was controlled by the non-redox transformation between magnetite and hematite throughout the experiments. While solution compositions were controlled by the non-redox transformation in the first 3 days in a 250 C experiment, reductive dissolution of magnetite became important after 5 days and affected the solution chemistry. At 100 C, the presence of maghemite was indicated in the first 7 days. Based on these results, equilibrium constants of non-redox transformation between magnetite and hematite and those of non-redox transformation between magnetite and maghemite were calculated. Our results suggest that the redox transformation of hematite to magnetite occurs in the following steps: (1) reductive dissolution of hematite to and (2) non-redox transformation of hematite and to magnetite.</p> <div class="credits"> <p class="dwt_author">Otake, Tsubasa [Pennsylvania State University; Wesolowski, David J [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Allard Jr, Lawrence Frederick [ORNL; Ohmoto, Hiroshi [Pennsylvania State University</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1007864"> <span id="translatedtitle">Mechanisms of <span class="hlt">iron</span> <span class="hlt">oxide</span> transformation in hydrothermal systems.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Coexistence of magnetite and hematite in hydrothermal systems has often been used to constrain the redox potential of fluids, assuming that the redox equilibrium is attained among all minerals and aqueous species. However, as temperature decreases, disequilibrium mineral assemblages may occur due to the slow kinetics of reaction involving the minerals and fluids. In this study, we conducted a series of experiments in which hematite or magnetite was reacted with an acidic solution under H{sub 2}-rich hydrothermal conditions (T = 100-250 C, P{sub H{sub 2}} = 0.05-5 MPa) to investigate the kinetics of redox and non-redox transformations between hematite and magnetite, and the mechanisms of <span class="hlt">iron</span> <span class="hlt">oxide</span> transformation under hydrothermal conditions. The formation of euhedral crystals of hematite in 150 and 200 C experiments, in which magnetite was used as the starting material, indicates that non-redox transformation of magnetite to hematite occurred within 24 h. The chemical composition of the experimental solutions was controlled by the non-redox transformation between magnetite and hematite throughout the experiments. While solution compositions were controlled by the non-redox transformation in the first 3 days in a 250 C experiment, reductive dissolution of magnetite became important after 5 days and affected the solution chemistry. At 100 C, the presence of maghemite was indicated in the first 7 days. Based on these results, equilibrium constants of non-redox transformation between magnetite and hematite and those of non-redox transformation between magnetite and maghemite were calculated. Our results suggest that the redox transformation of hematite to magnetite occurs in the following steps: (1) reductive dissolution of hematite to Fe{sub (aq)}{sup 2+} and (2) non-redox transformation of hematite and Fe{sub (aq)}{sup 2+} to magnetite.</p> <div class="credits"> <p class="dwt_author">Otake, Tsubasa [Pennsylvania State University; Wesolowski, David J [ORNL; Anovitz, Lawrence {Larry} M [ORNL</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009SPIE.7181E..0OC"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticle hyperthermia and radiation cancer treatment</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">It is established that heat can enhance the effect of radiation cancer treatment. Due to the ability to localize thermal energy using nanoparticle hyperthermia, as opposed to other, less targeted, hyperthermia modalities, it appears such enhancement could be accomplished without complications normally associated with systemic or regional hyperthermia. This study employs non-curative (suboptimal), doses of heat and radiation, in an effort to determine the therapeutic enhancement potential for IONP hyperthermia and radiation. Methods: MTG-B murine breast adenocarcinoma cell are inoculated into the right flanks of female CH3/HEJ mice and grown to volumes of 150mm3+ /- 40 mm3. A single dose of 15 Gy (6 MeV) radiation was uniformly delivered to the tumor. A pre-defined thermal dose is delivered by direct injection of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles into the tumor. By adjusting the field strength of the 160 KHz alternating magnetic field (AMF) an intra-tumoral temperature between 41.5 and 43 degrees Celsius was maintained for 10min. The alternating magnetic field was delivered by a water-cooled 36mm diameter square copper tube induction coil operating at 160 kHz with variable magnet field strengths up to 450 Oe . The primary endpoint of the study is the number of days required for the tumor to achieve a volume 3 fold greater than the volume at the time of treatment (tumor regrowth delay). Results: Preliminary results suggest the addition of a modest IONP hyperthermia to 15 Gy radiation achieved an approximate 50% increase in tumor regrowth delay as compared to a 15 Gy radiation treatment alone. The therapeutic effects of IONP heat and radiation combined were considered additive, however in mice that demonstrated complete response (no tumor present after 30 days), the effect was considered superadditive or synergistic. Although this data is very encouraging from a multimodality cancer therapy standpoint, additional temporal and dose related information is clearly necessary to optimize the therapy.</p> <div class="credits"> <p class="dwt_author">Cassim, S. M.; Giustini, A. J.; Petryk, A. A.; Strawbridge, R. A.; Hoopes, P. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AIPC.1626..138H"> <span id="translatedtitle">Magnetic field calculations for <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles for MRI</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The susceptibility effects of superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (SPIONs) functionalized with triethylenglycol (TREG) and Polyethylen Glycol (PEG) has been studied, those nanoparticles have the necessary properties to be used in the clinic as contrast media in imaging by MRI[1-3]. We are considering the behavior of the magnetic field as plane wave to explain the electrical and magnetic field produced by SPIONs. Images were acquired on a 1.5T imager Philips, using mFFE Sequence. Three glass capillary tubes with a) TREG (10nm) concentration of 300 ?g/ml, and PEGCOOH 6000(10nm) with 300 ?g/ml, and 2% agarosa. Magnetic field simulations were calculated in Matlab. The plane wave that comes in contact with a sphere of radius a, an propagation constant k1, and it is in an homogeneous space k2. We consider that the electric field is linearly polarized on x-direction, with a propagation on z-positive-axis. The secondary induced field can be explained from the interior of the sphere and valid exterior points. The referred waves are transmitted and reflected, this is valid only when the wavelength is smaller than the radius of the sphere. The obtained vibrational mode is an answer of the electrical oscillation and this is projection of the disturbed magnetic field. TREG-SPIONs produce more serious susceptibility artefacts compared to PEG-SPIONs. This study is promissory due to the concordance of the results of the simulations and the inhomogeneities showed in the MR images.</p> <div class="credits"> <p class="dwt_author">Hernandez, Ricardo; Mendez Rojas, Miguel; Dies Suarez, Pilar; Hidalgo Tobón, Silvia</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.whoi.edu/science/MCG/groundwater/pubs/PDF/Spiteri%20et%20al.pdf"> <span id="translatedtitle">pH-Dependent <span class="hlt">iron</span> <span class="hlt">oxide</span> precipitation in a subterranean estuary C. Spiteri a,*, P. Regnier a</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">pH-Dependent <span class="hlt">iron</span> <span class="hlt">oxide</span> precipitation in a subterranean estuary C. Spiteri a,*, P. Regnier a , C August 2005 Available online 11 November 2005 Abstract <span class="hlt">Iron-oxide</span>-coated sediment particles the factors controlling this Fe-<span class="hlt">oxide</span> precipitation. Here, we implement a simple reaction network in a 1D</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25233236"> <span id="translatedtitle">The mechanism of vapor phase <span class="hlt">hydration</span> of calcium <span class="hlt">oxide</span>: implications for CO2 capture.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Lime-based sorbents are used for fuel- and flue-gas capture, thereby representing an economic and effective way to reduce CO2 emissions. Their use involves cyclic carbonation/calcination which results in a significant conversion reduction with increasing number of cycles. To reactivate spent CaO, vapor phase <span class="hlt">hydration</span> is typically performed. However, little is known about the ultimate mechanism of such a <span class="hlt">hydration</span> process. Here, we show that the vapor phase <span class="hlt">hydration</span> of CaO formed after calcination of calcite (CaCO3) single crystals is a pseudomorphic, topotactic process, which progresses via an intermediate disordered phase prior to the final formation of oriented Ca(OH)2 nanocrystals. The strong structural control during this solid-state phase transition implies that the microstructural features of the CaO parent phase predetermine the final structural and physicochemical (reactivity and attrition) features of the product hydroxide. The higher molar volume of the product can create an impervious shell around unreacted CaO, thereby limiting the efficiency of the reactivation process. However, in the case of compact, sintered CaO structures, volume expansion cannot be accommodated in the reduced pore volume, and stress generation leads to pervasive cracking. This favors complete <span class="hlt">hydration</span> but also detrimental attrition. Implications of these results in carbon capture and storage (CCS) are discussed. PMID:25233236</p> <div class="credits"> <p class="dwt_author">Kud?acz, Krzysztof; Rodriguez-Navarro, Carlos</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-10-21</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23747468"> <span id="translatedtitle">Selective catalytic <span class="hlt">oxidation</span> of H?S over <span class="hlt">iron</span> <span class="hlt">oxide</span> supported on alumina-intercalated Laponite clay catalysts.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A series of <span class="hlt">iron</span> <span class="hlt">oxide</span> supported on alumina-intercalated clay catalysts (named Fe/Al-Lap catalysts) with mesoporous structure and high specific surface area were prepared. The structural and chemical properties were studied by nitrogen sorption isotherms, X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FTIR), H? temperature-programmed reduction (H?-TPR) and NH? temperature-programmed desorption (NH3-TPD) techniques. It was realized that <span class="hlt">iron</span> <span class="hlt">oxide</span> mainly existed in the form of isolated Fe(3+) in an <span class="hlt">oxidic</span> environment. Fe/Al-Lap catalysts showed high catalytic activities in the temperature range of 120-200 °C without the presence of excessive O?. This can be attributed to the interaction between <span class="hlt">iron</span> <span class="hlt">oxide</span> and alumina, which improve the redox property of Fe(3+) efficiently. In addition, the strong acidity of catalysts and good dispersion of <span class="hlt">iron</span> <span class="hlt">oxide</span> were also beneficial to <span class="hlt">oxidation</span> reaction. Among them, 7% Fe/Al-Lap catalyst presented the best catalytic performance at 180 °C. Finally, the catalytic and deactivation mechanisms were explored. PMID:23747468</p> <div class="credits"> <p class="dwt_author">Zhang, Xin; Dou, Guangyu; Wang, Zhuo; Li, Li; Wang, Yufei; Wang, Hailin; Hao, Zhengping</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://repository.tamu.edu/handle/1969.1/ETD-TAMU-2011-12-10258"> <span id="translatedtitle">Bioinspired Synthesis and Reactivity Studies of Nitric <span class="hlt">Oxide</span> <span class="hlt">Iron</span> Complexes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">bound to the serum albumin protein via histidine.42 Similarly, addition of NO to aconitase resulted in a transient <span class="hlt">iron</span>-nitrosyl-histidyl-aconitase complex observed by EPR spectroscopy as well as formation of an <span class="hlt">iron</span>-nitrosyl-thiol- aconitase complex...</p> <div class="credits"> <p class="dwt_author">Hess, Jennifer</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-02-14</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=105055"> <span id="translatedtitle">THE <span class="hlt">IRON</span> CYCLE AND <span class="hlt">OXIDATIVE</span> STRESS IN THE LUNG</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">While <span class="hlt">iron</span> is essential for many aspects of cellular function, it can also generate oxygen-based free radicals that result in injury to biological molecules. For this reason, <span class="hlt">iron</span> acquisition and distribution must be tightly regulated. Constant exposure to the atmosphere, howev...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://web.mit.edu/dsadoway/www/137.pdf"> <span id="translatedtitle">Electrolysis of Molten <span class="hlt">Iron</span> <span class="hlt">Oxide</span> with an Iridium Anode: The Role of Electrolyte Basicity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Electrolysis of Molten <span class="hlt">Iron</span> <span class="hlt">Oxide</span> with an Iridium Anode: The Role of Electrolyte Basicity Hojong electrolysis (MOE) is a carbon-free, electrochemical technique to decompose a metal <span class="hlt">oxide</span> directly into liquid. Electrolysis is being investigated by the steel industry as a carbon-lean route that copes with the potential</p> <div class="credits"> <p class="dwt_author">Sadoway, Donald Robert</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1041591"> <span id="translatedtitle">Electrochemical Deposition of <span class="hlt">Iron</span> Nanoneedles on Titanium <span class="hlt">Oxide</span> Nanotubes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Iron</span> as a catalyst has wide applications for hydrogen generation from ammonia, photodecomposition of organics, and carbon nanotube growth. Tuning the size and shape of <span class="hlt">iron</span> is meaningful for improving the catalysis efficiency. It is the objective of this work to prepare nanostructured <span class="hlt">iron</span> with high surface area via electrochemical deposition. <span class="hlt">Iron</span> nanoneedles were successfully electrodeposited on Ti supported TiO2 nanotube arrays in a chlorine-based electrolyte containing 0.15 M FeCl2 {center_dot} 4H2O and 2.0 M HCl. Transmission electron microscopic analysis reveals that the average length of the nanoneedles is about 200 nm and the thickness is about 10 nm. It has been found that a high overpotential at the cathode made of Ti/TiO2 nanotube arrays is necessary for the formation of the nanoneedles. Cyclic voltammetry test indicates that the electrodeposition of <span class="hlt">iron</span> nanoneedles is a concentration-limited process.</p> <div class="credits"> <p class="dwt_author">Gan Y. X.; Zhang L.; Gan B.J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">356</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21518300"> <span id="translatedtitle">Doped, porous <span class="hlt">iron</span> <span class="hlt">oxide</span> films and their optical functions and anodic photocurrents for solar water splitting</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The fabrication and morphological, optical, and photoelectrochemical characterization of doped <span class="hlt">iron</span> <span class="hlt">oxide</span> films is presented. The complex index of refraction and absorption coefficient of polycrystalline films are determined through measurement and modeling of spectral transmission and reflection data using appropriate dispersion relations. Photoelectrochemical characterization for water photo-<span class="hlt">oxidation</span> reveals that the conversion efficiencies of electrodes are strongly influenced by substrate temperature during their oblique-angle physical vapor deposition. These results are discussed in terms of the films' morphological features and the known optoelectronic limitations of <span class="hlt">iron</span> <span class="hlt">oxide</span> films for application in solar water splitting devices.</p> <div class="credits"> <p class="dwt_author">Kronawitter, Coleman X.; Mao, Samuel S. [Department of Mechanical Engineering, University of California at Berkeley, Berkeley, California 94720, USA and Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Antoun, Bonnie R. [Sandia National Laboratories, Livermore, California 94551 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-02-28</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">357</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19940007656&hterms=Ferrous+Sulfide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DFerrous%2BSulfide"> <span id="translatedtitle">Chemical weathering on Mars: Rate of <span class="hlt">oxidation</span> of <span class="hlt">iron</span> dissolved in brines</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Salts believed to occur in Martian regolith imply that brines occur on Mars, which may have facilitated the <span class="hlt">oxidation</span> of dissolved Fe(2+) ions after they were released during chemical weathering of basaltic ferromagnesian silicate and <span class="hlt">iron</span> sulfide minerals. Calculations show that the rate of <span class="hlt">oxidation</span> of Fe(2+) ions at -35 C in a 6M chloride-sulfate brine that might exist on Mars is about 10(exp 6) times slower that the <span class="hlt">oxidation</span> rate of <span class="hlt">iron</span> in ice-cold terrestrial seawater.</p> <div class="credits"> <p class="dwt_author">Burns, Roger G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">358</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3348679"> <span id="translatedtitle"><span class="hlt">Oxidation</span> of Low-Density Lipoprotein by <span class="hlt">Iron</span> at Lysosomal pH: Implications for Atherosclerosis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Low-density lipoprotein (LDL) has recently been shown to be <span class="hlt">oxidized</span> by <span class="hlt">iron</span> within the lysosomes of macrophages, and this is a novel potential mechanism for LDL <span class="hlt">oxidation</span> in atherosclerosis. Our aim was to characterize the chemical and physical changes induced in LDL by <span class="hlt">iron</span> at lysosomal pH and to investigate the effects of <span class="hlt">iron</span> chelators and ?-tocopherol on this process. LDL was <span class="hlt">oxidized</span> by <span class="hlt">iron</span> at pH 4.5 and 37 °C and its <span class="hlt">oxidation</span> monitored by spectrophotometry and high-performance liquid chromatography. LDL was <span class="hlt">oxidized</span> effectively by FeSO4 (5–50 ?M) and became highly aggregated at pH 4.5, but not at pH 7.4. The level of cholesteryl esters decreased, and after a pronounced lag, the level of 7-ketocholesterol increased greatly. The total level of hydroperoxides (measured by the triiodide assay) increased up to 24 h and then decreased only slowly. The lipid composition after 12 h at pH 4.5 and 37 °C was similar to that of LDL <span class="hlt">oxidized</span> by copper at pH 7.4 and 4 °C, i.e., rich in hydroperoxides but low in oxysterols. Previously <span class="hlt">oxidized</span> LDL aggregated rapidly and spontaneously at pH 4.5, but not at pH 7.4. Ferrous <span class="hlt">iron</span> was much more effective than ferric <span class="hlt">iron</span> at <span class="hlt">oxidizing</span> LDL when added after the <span class="hlt">oxidation</span> was already underway. The <span class="hlt">iron</span> chelators diethylenetriaminepentaacetic acid and, to a lesser extent, desferrioxamine inhibited LDL <span class="hlt">oxidation</span> when added during its initial stages but were unable to prevent aggregation of LDL after it had been partially <span class="hlt">oxidized</span>. Surprisingly, desferrioxamine increased the rate of LDL modification when added late in the <span class="hlt">oxidation</span> process. ?-Tocopherol enrichment of LDL initially increased the rate of <span class="hlt">oxidation</span> of LDL but decreased it later. The presence of <span class="hlt">oxidized</span> and highly aggregated lipid within lysosomes has the potential to perturb the function of these organelles and to promote atherosclerosis. PMID:22493939</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">359</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22493939"> <span id="translatedtitle"><span class="hlt">Oxidation</span> of low-density lipoprotein by <span class="hlt">iron</span> at lysosomal pH: implications for atherosclerosis.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Low-density lipoprotein (LDL) has recently been shown to be <span class="hlt">oxidized</span> by <span class="hlt">iron</span> within the lysosomes of macrophages, and this is a novel potential mechanism for LDL <span class="hlt">oxidation</span> in atherosclerosis. Our aim was to characterize the chemical and physical changes induced in LDL by <span class="hlt">iron</span> at lysosomal pH and to investigate the effects of <span class="hlt">iron</span> chelators and ?-tocopherol on this process. LDL was <span class="hlt">oxidized</span> by <span class="hlt">iron</span> at pH 4.5 and 37 °C and its <span class="hlt">oxidation</span> monitored by spectrophotometry and high-performance liquid chromatography. LDL was <span class="hlt">oxidized</span> effectively by FeSO(4) (5-50 ?M) and became highly aggregated at pH 4.5, but not at pH 7.4. The level of cholesteryl esters decreased, and after a pronounced lag, the level of 7-ketocholesterol increased greatly. The total level of hydroperoxides (measured by the triiodide assay) increased up to 24 h and then decreased only slowly. The lipid composition after 12 h at pH 4.5 and 37 °C was similar to that of LDL <span class="hlt">oxidized</span> by copper at pH 7.4 and 4 °C, i.e., rich in hydroperoxides but low in oxysterols. Previously <span class="hlt">oxidized</span> LDL aggregated rapidly and spontaneously at pH 4.5, but not at pH 7.4. Ferrous <span class="hlt">iron</span> was much more effective than ferric <span class="hlt">iron</span> at <span class="hlt">oxidizing</span> LDL when added after the <span class="hlt">oxidation</span> was already underway. The <span class="hlt">iron</span> chelators diethylenetriaminepentaacetic acid and, to a lesser extent, desferrioxamine inhibited LDL <span class="hlt">oxidation</span> when added during its initial stages but were unable to prevent aggregation of LDL after it had been partially <span class="hlt">oxidized</span>. Surprisingly, desferrioxamine increased the rate of LDL modification when added late in the <span class="hlt">oxidation</span> process. ?-Tocopherol enrichment of LDL initially increased the rate of <span class="hlt">oxidation</span> of LDL but decreased it later. The presence of <span class="hlt">oxidized</span> and highly aggregated lipid within lysosomes has the potential to perturb the function of these organelles and to promote atherosclerosis. PMID:22493939</p> <div class="credits"> <p class="dwt_author">Satchell, Leanne; Leake, David S</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">360</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21899208"> <span id="translatedtitle">Assessment of the extent of <span class="hlt">oxidative</span> stress induced by intravenous ferumoxytol, ferric carboxymaltose, <span class="hlt">iron</span> sucrose and <span class="hlt">iron</span> dextran in a nonclinical model.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Intravenous (i.v.) <span class="hlt">iron</span> is associated with a risk of <span class="hlt">oxidative</span> stress. The effects of ferumoxytol, a recently approved i.v. <span class="hlt">iron</span> preparation, were compared with those of ferric carboxymaltose, low molecular weight <span class="hlt">iron</span> dextran and <span class="hlt">iron</span> sucrose in the liver, kidneys and heart of normal rats. In contrast to <span class="hlt">iron</span> sucrose and ferric carboxymaltose, low molecular weight <span class="hlt">iron</span> dextran and ferumoxytol caused renal and hepatic damage as demonstrated by proteinuria and increased liver enzyme levels. Higher levels of <span class="hlt">oxidative</span> stress in these tissues were also indicated, by significantly higher levels of malondialdehyde, significantly increased antioxidant enzyme activities, and a significant reduction in the reduced to <span class="hlt">oxidized</span> glutathione ratio. Inflammatory markers were also significantly higher with ferumoxytol and low molecular weight <span class="hlt">iron</span> dextran rats than <span class="hlt">iron</span> sucrose and ferric carboxymaltose. Polarographic analysis suggested that ferumoxytol contains a component with a more positive reduction potential, which may facilitate <span class="hlt">iron</span>-catalyzed formation of reactive oxygen species and thus be responsible for the observed effects. Only low molecular weight <span class="hlt">iron</span> dextran induced <span class="hlt">oxidative</span> stress and inflammation in the heart. PMID:21899208</p> <div class="credits"> <p class="dwt_author">Toblli, Jorge E; Cao, Gabriel; Oliveri, Leda; Angerosa, Margarita</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_17");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">361</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/514711"> <span id="translatedtitle">Hydrothermal synthesis of <span class="hlt">iron</span> and zinc double vanadium <span class="hlt">oxides</span> using the tetramethyl ammonium ion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">There has been much effort recently to find more cost-effective <span class="hlt">oxide</span> cathodes for advanced lithium batteries, to replace the technically excellent but expensive lithium cobalt <span class="hlt">oxide</span>. The authors have studied the hydrothermal synthesis of tetramethyl ammonium vanadium <span class="hlt">oxides</span> that contain an additional transition metal, such as <span class="hlt">iron</span> or zinc, in order to stabilize the layered structure of vanadium <span class="hlt">oxide</span> for electrochemical redox reactions with lithium. Addition of the lower cost <span class="hlt">iron</span> and zinc is also beneficial for commercial application. Several new layered structures which contain double sheets of V{sub 2}O{sub 5} have been formed and characterized. The <span class="hlt">iron</span> compound contains the TMA ion. Their structures and electrochemical behavior are reported.</p> <div class="credits"> <p class="dwt_author">Fan Zhang; Zavalij, P.Y.; Whittingham, M.S. [State Univ. of New York, Binghamton, NY (United States)] [State Univ. of New York, Binghamton, NY (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">362</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/1052976"> <span id="translatedtitle">Characterization and Properties of Metallic <span class="hlt">Iron</span> and <span class="hlt">Iron-Oxide</span> Nanoparticles: Spectroscopy, Electrochemistry, and Kinetics</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">There are reports that nano-sized zero-valent <span class="hlt">iron</span> (Fe0) exhibits greater reactivity than micro-sized particles of Fe0, and it has been suggested that the higher reactivity of nano-Fe0 may impart advantages for groundwater remediation or other environmental applications. However, most of these reports are preliminary in that they leave a host of potentially significant (and often challenging) material or process variables either uncontrolled or unresolved. In an effort to better understand the reactivity of nano-Fe0, we have used a variety of complementary techniques to characterize two widely studied nano-Fe0 preparations:Ã?¢Ã?Â?Ã?Â? one synthesized by reduction of goethite with heat and H2 (FeH2) and the other by reductive precipitation with borohydride (FeBH). FeH2 is a two-phase material consisting of 40 nm Ã?Â?Ã?±-Fe0 (made up of crystals approximately the size of the particles) and Fe3O4 particles of similar size or larger containing reduced sulfur; whereas FeBH is mostly 20Ã?¢Ã?Â?Ã?Â?80 nm metallic Fe particles (aggregates of <1.5 nm grains) with an <span class="hlt">oxide</span> shell/coating that is high in <span class="hlt">oxidized</span> boron. The FeBH particles further aggregate into chains. Both materials exhibit corrosion potentials that are more negative than nano-sized Fe2O3, Fe3O4, micro-sized Fe0, or a solid Fe0 disk, which is consistent with their rapid reduction of oxygen, benzoquinone, and carbon tetrachloride. Benzoquinonewhich presumably probes inner-sphere surface reactionsreacts more rapidly with FeBH than FeH2, whereas carbon tetrachloride reacts at similar rates with FeBH and FeH2, presumably by outer-sphere electron transfer. Both types of nano-Fe0 react more rapidly than micro-sized Fe0 based on mass-normalized rate constants, but surface area-normalized rate constants do not show a significant nano-size effect. The distribution of products from reduction of carbon tetrachloride is more favorable with FeH2, which produces less chloroform than reaction with FeBH.</p> <div class="credits"> <p class="dwt_author">JT Nurmi; PG Tratnyek; V Sarathy; DR Baer; JE Amonette; K Pecher; CM Wang; JC Linehan; DW Matson; RL Penn; MD Driessen</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">363</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.nlm.nih.gov/medlineplus/iron.html"> <span id="translatedtitle"><span class="hlt">Iron</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://medlineplus.gov/">MedlinePLUS</a></p> <p class="result-summary"><span class="hlt">Iron</span> is a mineral that our bodies need for many functions. For example, <span class="hlt">iron</span> is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. <span class="hlt">Iron</span> is also part of many other proteins and ...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">364</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3876768"> <span id="translatedtitle">Beta-Thalassemia Major and Female Fertility: The Role of <span class="hlt">Iron</span> and <span class="hlt">Iron</span>-Induced <span class="hlt">Oxidative</span> Stress</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Endocrine complications due to haemosiderosis are present in a significant number of patients with beta-thalassemia major (BTM) worldwide and often become barriers in their desire for parenthood. Thus, although spontaneous fertility can occur, the majority of females with BTM is infertile due to hypogonadotropic hypogonadism (HH) and need assisted reproductive techniques. Infertility in these women seems to be attributed to <span class="hlt">iron</span> deposition and <span class="hlt">iron</span>-induced <span class="hlt">oxidative</span> stress (OS) in various endocrine organs, such as hypothalamus, pituitary, and female reproductive system, but also through the <span class="hlt">iron</span> effect on other organs, such as liver and pancreas, contributing to the impaired metabolism of hormones and serum antioxidants. Nevertheless, the gonadal function of these patients is usually intact and fertility is usually retrievable. Meanwhile, a significant prooxidants/antioxidants imbalance with subsequent increased (OS) exists in patients with BTM, which is mainly caused by tissue injury due to overproduction of free radicals by secondary <span class="hlt">iron</span> overload, but also due to alteration in serum trace elements and antioxidant enzymes. Not only using the appropriate antioxidants, essential trace elements, and minerals, but also regulating the advanced glycation end products, could probably reduce the extent of <span class="hlt">oxidative</span> damage and related complications and retrieve BTM women's infertility. PMID:24396593</p> <div class="credits"> <p class="dwt_author">Roussou, Paraskevi; Tsagarakis, Nikolaos J.; Diamanti-Kandarakis, Evanthia</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">365</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24992833"> <span id="translatedtitle">Comparison of various <span class="hlt">iron</span> chelators and prochelators as protective agents against cardiomyocyte <span class="hlt">oxidative</span> injury.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Oxidative</span> stress is a common denominator of numerous cardiovascular disorders. Free cellular <span class="hlt">iron</span> catalyzes the formation of highly toxic hydroxyl radicals, and <span class="hlt">iron</span> chelation may thus be an effective therapeutic approach. However, using classical <span class="hlt">iron</span> chelators in diseases without <span class="hlt">iron</span> overload poses risks that necessitate more advanced approaches, such as prochelators that are activated to chelate <span class="hlt">iron</span> only under disease-specific <span class="hlt">oxidative</span> stress conditions. In this study, three cell-membrane-permeable <span class="hlt">iron</span> chelators (clinically used deferasirox and experimental SIH and HAPI) and five boronate-masked prochelator analogs were evaluated for their ability to protect cardiac cells against <span class="hlt">oxidative</span> injury induced by hydrogen peroxide. Whereas the deferasirox-derived agents TIP and TRA-IMM displayed negligible protection and even considerable toxicity, the aroylhydrazone prochelators BHAPI and BSIH-PD provided significant cytoprotection and displayed lower toxicity after prolonged cellular exposure compared to their parent chelators HAPI and SIH, respectively. Overall, the most favorable properties in terms of protective efficiency and low inherent cytotoxicity were observed with the aroylhydrazone prochelator BSIH. BSIH efficiently protected both H9c2 rat cardiomyoblast-derived cells and isolated primary rat cardiomyocytes against hydrogen peroxide-induced mitochondrial and lysosomal dysregulation and cell death. At the same time, BSIH was nontoxic at concentrations up to its solubility limit (600 ?M) and in 72-h incubation. Hence, BSIH merits further investigation for prevention and/or treatment of cardiovascular disorders associated with a known (or presumed) component of <span class="hlt">oxidative</span> stress. PMID:24992833</p> <div class="credits"> <p class="dwt_author">Jansová, Hana; Machá?ek, Miloslav; Wang, Qin; Hašková, Pavlína; Jirkovská, Anna; Pot??ková, Eliška; Kielar, Filip; Franz, Katherine J; Sim?nek, Tomáš</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">366</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22210211"> <span id="translatedtitle">Superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles as radiosensitizer via enhanced reactive oxygen species formation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Highlights: Black-Right-Pointing-Pointer Ultrasmall citrate-coated SPIONs with {gamma}Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} structure were prepared. Black-Right-Pointing-Pointer SPIONs uptaken by MCF-7 cells increase the ROS production for about 240%. Black-Right-Pointing-Pointer The SPION induced ROS production is due to released <span class="hlt">iron</span> ions and catalytically active surfaces. Black-Right-Pointing-Pointer Released <span class="hlt">iron</span> ions and SPION surfaces initiate the Fenton and Haber-Weiss reaction. Black-Right-Pointing-Pointer X-ray irradiation of internalized SPIONs leads to an increase of catalytically active surfaces. -- Abstract: Internalization of citrate-coated and uncoated superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles by human breast cancer (MCF-7) cells was verified by transmission electron microscopy imaging. Cytotoxicity studies employing metabolic and trypan blue assays manifested their excellent biocompatibility. The production of reactive oxygen species in <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle loaded MCF-7 cells was explained to originate from both, the release of <span class="hlt">iron</span> ions and their catalytically active surfaces. Both initiate the Fenton and Haber-Weiss reaction. Additional <span class="hlt">oxidative</span> stress caused by X-ray irradiation of MCF-7 cells was attributed to the increase of catalytically active <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle surfaces.</p> <div class="credits"> <p class="dwt_author">Klein, Stefanie; Sommer, Anja [Department of Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstr. 3, D-91058 Erlangen (Germany)] [Department of Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstr. 3, D-91058 Erlangen (Germany); Distel, Luitpold V.R. [Department of Radiation Oncology, Friedrich Alexander University Erlangen-Nuremberg, Universitaetsstrasse 27, D-91054 Erlangen (Germany)] [Department of Radiation Oncology, Friedrich Alexander University Erlangen-Nuremberg, Universitaetsstrasse 27, D-91054 Erlangen (Germany); Neuhuber, Winfried [Department of Anatomy, Chair of Anatomy I, Friedrich Alexander University Erlangen-Nuremberg, Krankenhausstr. 9, D-91054 Erlangen (Germany)] [Department of Anatomy, Chair of Anatomy I, Friedrich Alexander University Erlangen-Nuremberg, Krankenhausstr. 9, D-91054 Erlangen (Germany); Kryschi, Carola, E-mail: kryschi@chemie.uni-erlangen.de [Department of Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstr. 3, D-91058 Erlangen (Germany)] [Department of Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstr. 3, D-91058 Erlangen (Germany)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-24</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">367</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4243170"> <span id="translatedtitle">Comparison of various <span class="hlt">iron</span> chelators and prochelators as protective agents against cardiomyocyte <span class="hlt">oxidative</span> injury</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Oxidative</span> stress is a common denominator of numerous cardiovascular disorders. Free cellular <span class="hlt">iron</span> catalyzes formation of highly toxic hydroxyl radicals and <span class="hlt">iron</span> chelation may thus be an effective therapeutic approach. However, using classical <span class="hlt">iron</span> chelators in diseases without <span class="hlt">iron</span> overload poses risks that necessitate more advanced approaches, such as prochelators that are activated to chelate <span class="hlt">iron</span> only under disease-specific <span class="hlt">oxidative</span> stress conditions. In this study, three cell membrane-permeable <span class="hlt">iron</span> chelators (clinically-used deferasirox and experimental SIH and HAPI) and five boronate-masked prochelator analogs were evaluated for their ability to protect cardiac cells against <span class="hlt">oxidative</span> injury induced by hydrogen peroxide. Whereas the deferasirox-derived agents TIP and TRA-IMM displayed negligible protection and even considerable toxicity, aroylhydrazone prochelators BHAPI and BSIH-PD provided significant cytoprotection and displayed lower toxicity following prolonged cellular exposure compared to their parent chelators HAPI and SIH, respectively. Overall, the most favorable properties in terms of protective efficiency and low inherent cytotoxicity were observed with aroylhydrazone prochelator BSIH. BSIH efficiently protected both H9c2 rat cardiomyoblast-derived cells as well as isolated primary rat cardiomyocytes against hydrogen peroxide-induced mitochondrial and lysosomal dysregulation and cell death. At the same time, BSIH was non-toxic at concentrations up to its solubility limit (600 µM) and 72-hour incubation. Hence, BSIH merits further investigation for prevention and/or treatment of cardiovascular disorders associated with a known (or presumed) component of <span class="hlt">oxidative</span> stress. PMID:24992833</p> <div class="credits"> <p class="dwt_author">Jansová, Hana; Machá?ek, Miloslav; Wang, Qin; Hašková, Pavlína; Jirkovská, Anna; Pot??ková, Eliška; Kielar, Filip; Franz, Katherine J.; Šim?nek, Tomáš</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">368</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009IJMPB..23.1529A"> <span id="translatedtitle">Growth of Carbon Nanotubes on <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoparticles Catalyst Derived from <span class="hlt">Iron</span> Storage Protein-Ferritin by Cvd Method</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Here we used the <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles derived from ferritin as catalyst for the synthesis of carbon nanotubes (CNTs) by the chemical vapor deposition (CVD) of coal gas. It has been found that the structure and morphology of CNTs can be tailored, to some degree, by varying the experimental conditions such as catalyst loading and process parameters. In addition to straight CNTs, some Y-branched CNTs were also obtained, which might be due to the sulfur species in the coal gas.</p> <div class="credits"> <p class="dwt_author">An, Yuliang; Liu, Yanqiu; Yuan, Xia; Tan, Hao</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">369</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/11732984"> <span id="translatedtitle">A revised scheme for the reactivity of <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> minerals towards dissolved sulfide</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The reaction between dissolved sulfide and synthetic <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> minerals was studied in artificial seawater and 0.1 M NaCl at pH 7.5 and 25°C. Electron transfer between surface-complexed sulfide and solid-phase Fe(III) results in the <span class="hlt">oxidation</span> of dissolved sulfide to elemental sulfur, and the subsequent dissolution of the surface-reduced Fe. Sulfide <span class="hlt">oxidation</span> and Fe(II) dissolution kinetics were evaluated for freshly</p> <div class="credits"> <p class="dwt_author">Simon W. Poulton; Michael D. Krom; Robert Raiswell</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">370</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/22632684"> <span id="translatedtitle">Surface reactivity of polypyrrole\\/<span class="hlt">iron-oxide</span> nanoparticles: electrochemical and CS-AFM investigations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Composite materials based on <span class="hlt">iron-oxide</span> nanoparticles (magnetite, hematite, and maghemite) and tetraoxalate-doped polypyrrole\\u000a (PPy) were electrochemically generated from aqueous solutions. Their composition was determined using electrochemical quartz\\u000a crystal microbalance experiments. The <span class="hlt">oxide</span> percentage in mass was found to vary from 17 to 27% depending on the <span class="hlt">oxide</span> identity.\\u000a They were all shown to be fascinating candidates as protective materials against</p> <div class="credits"> <p class="dwt_author">A. Pailleret; N. T. L. Hien; D. T. M. Thanh; C. Deslouis</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">371</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/ofr2003196"> <span id="translatedtitle">Spectral reflectance properties (0.4-2.5 um) of secondary Fe-<span class="hlt">oxide</span>, Fe-hydroxide, and Fe-sulfate-<span class="hlt">hydrate</span> minerals associated with sulfide-bearing mine waste</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Fifteen Fe-<span class="hlt">oxide</span>, Fe-hydroxide, and Fe-sulphate-<span class="hlt">hydrate</span> mineral species commonly associated with sulphide bearing mine wastes were characterized by using X-ray powder diffraction and scanning electron microscope methods. Diffuse reflectance spectra of the samples show diagnostic absorption features related to electronic processes involving ferric and/or ferrous <span class="hlt">iron</span>, and to vibrational processes involving water and hydroxyl ions. Such spectral features enable field and remote sensing based studies of the mineral distributions. Because secondary minerals are sensitive indicators of pH, Eh, relative humidity, and other environmental conditions, spectral mapping of these minerals promises to have important applications to mine waste remediation studies. This report releases digital (ascii) spectra (spectral_data_files.zip) of the fifteen mineral samples to facilitate usage of the data with spectral libraries and spectral analysis software. The spectral data are provided in a two-column format listing wavelength (in micrometers) and reflectance, respectively.</p> <div class="credits"> <p class="dwt_author">Crowley, J.K.; Williams, D.E.; Hammarstrom1, J.M.; Piatak, N.; Mars, J.C.; Chou, I-Ming</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">372</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014ApSS..319..339Q"> <span id="translatedtitle">Effects of hydrazine <span class="hlt">hydrate</span> treatment on the performance of reduced graphene <span class="hlt">oxide</span> film as counter electrode in dye-sensitized solar cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The reduced graphene <span class="hlt">oxide</span> (RGO) counter electrodes were prepared by drop casting method and followed by heat treatment. The as-prepared RGO counter electrodes were used as substitution for Pt counter electrode in dye-sensitized solar cells (DSSCs). The effects of hydrazine <span class="hlt">hydrate</span> in graphene <span class="hlt">oxide</span> (GO) suspension on the performance of RGO counter electrodes were investigated. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements revealed that a moderate amount of hydrazine <span class="hlt">hydrate</span> can enhance the catalytic activity of the RGO film toward the reduction of I3- and decrease the sheet resistance of the film. The efficiency (?) of DSSC based on the RGO counter electrodes with optimum addition of hydrazine <span class="hlt">hydrate</span> increased from 1.826% to 2.622% under a simulated solar illumination of 100 mW cm-2 (AM 1.5).</p> <div class="credits"> <p class="dwt_author">Qiu, Leifei; Zhang, Haiyan; Wang, Wenguang; Chen, Yiming; Wang, Rong</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">373</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20140013482&hterms=increased+inflammatory+state&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dincreased%2Binflammatory%2Bstate"> <span id="translatedtitle">Risk of <span class="hlt">Oxidative</span> Damage to Bone from Increased <span class="hlt">Iron</span> Stores During Space Flight</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Iron</span> stores are increased secondary to neocytolysis of red blood cells and a high dietary intake of <span class="hlt">iron</span> during space flight. This raises concerns about the risk of excess <span class="hlt">iron</span> causing <span class="hlt">oxidative</span> damage in many tissues, including bone. Biomarkers of <span class="hlt">iron</span> status, <span class="hlt">oxidative</span> damage, and bone resorption during space flight were analyzed for 23 (16 M/7 F) International Space Station crewmembers as part of the Nutrition SMO project. Up to 5 in-flight blood samples and 24-h urine pools were collected over the course of the 4-6 month missions. Serum <span class="hlt">iron</span> increased slightly during space flight and was decreased at landing (P < 0.0004). An increase in serum ferritin early in flight (217% in women and 68% in men, P < 0.0004), returning to preflight concentrations at landing, and a decrease in transferrin and transferrin receptors during flight indicated that a transient increase in <span class="hlt">iron</span> stores occurred. No inflammatory response was observed during flight. The <span class="hlt">oxidative</span> damage markers 8-hydroxy-2'-deoxyguanosine and prostaglandin F(sub 2(alpha)) were positively correlated (both P < 0.001) with serum ferritin. A greater area under the curve for ferritin during flight was correlated with greater changes in bone mineral density of several bone regions after flight (1). In a separate study (2), a ground-based investigation was conducted that examined the combined effects of radiation exposure and <span class="hlt">iron</span> overload on sensitivity to radiation injury in several physiological systems in 12-wk male Sprague-Dawley rats. The rats were acclimated to an adequate <span class="hlt">iron</span> diet (45 mg <span class="hlt">iron</span> (ferric citrate)/kg diet) for 3 wk and then assigned to one of four groups: adequate <span class="hlt">iron</span> (Fe) diet/no radiation, adequate Fe diet/ radiation, moderately high Fe diet (650 mg Fe (ferric citrate)/kg diet)/no radiation, and moderately high Fe diet/radiation. Animals remained on the assigned diet for 4 wk. Starting on day 14 of experimental diet treatment, animals were exposed to a fractionated dose (0.375 Gy) of Cs-137 every other day (3 Gy total dose). On day 29 (24 h after last radiation exposure), animals were euthanized. <span class="hlt">Oxidative</span> stress markers in the liver, bone, eyes, and serum were assessed. There was evidence that the <span class="hlt">iron</span> diet contributed to DNA damage as well as radiation exposure in the liver, eyes, and bone. Together, the results suggest that increased <span class="hlt">iron</span> stores do constitute a risk factor for <span class="hlt">oxidative</span> damage and bone resorption, during space flight and on Earth. Funded by the Human Health and Countermeasures Element of the NASA Human Research Program.</p> <div class="credits"> <p class="dwt_author">Zwart, S. R.; Smith, S. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">374</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20088555"> <span id="translatedtitle">Effect of <span class="hlt">hydration</span> on the hydrogen abstraction reaction by HO in DMS and its <span class="hlt">oxidation</span> products.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The gas-phase hydrogen abstraction reaction between the HO radical and sulfur containing species in the absence and presence of a single water molecule is investigated theoretically. The sulfur containing species dimethyl sulfide, dimethyl sulfoxide, and dimethyl sulfone are considered. The calculations are carried out with a mixture of density function theory and second order Møller-Plesset perturbation theory. We find that the energy of the <span class="hlt">hydrated</span> transition state structures for the hydrogen abstraction reactions is lowered compared to that of the nonhydrated ones. Furthermore, the energy difference between the reaction complex and the transition state is reduced when one water molecule is added. The atmospheric abundance of the different <span class="hlt">hydrated</span> complexes is estimated in order to assess the relative importance of the possible reaction mechanisms. PMID:20088555</p> <div class="credits"> <p class="dwt_author">Jørgensen, Solvejg; Kjaergaard, Henrik G</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-04-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">375</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/m7488m71832480j8.pdf"> <span id="translatedtitle">Comparison of injectable <span class="hlt">iron</span> complexes in their ability to <span class="hlt">iron</span> load tissues and to induce <span class="hlt">oxidative</span> stress</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Iron</span> and copper homeostasis have been studied in various tissues after <span class="hlt">iron</span>-loading with the polynuclear ferric hydroxide carbohydrate complexes, <span class="hlt">iron</span> dextran, <span class="hlt">iron</span> polymaltose, <span class="hlt">iron</span> sucrose and <span class="hlt">iron</span> gluconate for four weeks. There were significant increases in the <span class="hlt">iron</span> content of the different rat tissues compared to controls, with the exception of the brain, which showed no change in its <span class="hlt">iron</span></p> <div class="credits"> <p class="dwt_author">R. Legssyer; P. Geisser; Harry McArdle; R. R. Crichton; R. J. Ward</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">376</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41761211"> <span id="translatedtitle">Solubilization of plutonium hydrous <span class="hlt">oxide</span> by <span class="hlt">iron</span>-reducing bacteria</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The removal of plutonium from soils id challenging because of its strong sorption to soils and limited solubility, Microbial reduction of metals is known to affect the speciation and solubility of sparingly soluble metals in the environment, notably <span class="hlt">iron</span> and manganese. The similarity in reduction potential for [alpha]-FeOOH(s) and hydrous PuO[sub 2](s) suggests that <span class="hlt">iron</span>-reducing bacteria may also reduce and</p> <div class="credits"> <p class="dwt_author">Patricia A. Rusin; Leticia Quintana; James R. Brainard; B. A. Strietelmeler; C. Drew Tait; Scott A. Ekberg; Phillip D. Palmer; Thomas W. Newton; David L. Clark</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">377</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013MMTB...44.1000S"> <span id="translatedtitle">Study of Organic and Inorganic Binders on Strength of <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Pellets</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Bentonite is a predominant binder used in <span class="hlt">iron</span> ore pelletization. However, the presence of a high content of silica and alumina in bentonite is considered undesirable for ironmaking operations. The objective of this study was to identify the alternatives of bentonite for <span class="hlt">iron</span> ore pelletization. To achieve this goal, different types of organic and inorganic binders were utilized to produce <span class="hlt">iron</span> <span class="hlt">oxide</span> pellets. The quality of these <span class="hlt">iron</span> <span class="hlt">oxide</span> pellets was compared with pellets made using bentonite. All pellets were tested for physical strength at different stages of pelletization to determine their ability to survive during shipping and handling. The results show that organic binders such as lactose monohydrate, hemicellulose, and sodium lignosulfonate can provide sufficient strength to indurated pellets.</p> <div class="credits"> <p class="dwt_author">Srivastava, Urvashi; Kawatra, S. Komar; Eisele, Timothy C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">378</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3697272"> <span id="translatedtitle">Deposition of Biogenic <span class="hlt">Iron</span> Minerals in a Methane <span class="hlt">Oxidizing</span> Microbial Mat</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic <span class="hlt">oxidation</span> of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and <span class="hlt">iron</span> sulfides, building up these chimneys. <span class="hlt">Iron</span> sulfides are generated by the microbial reduction of <span class="hlt">oxidized</span> sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic <span class="hlt">iron</span> sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger <span class="hlt">iron</span> sulfide mineral aggregates. PMID:23843725</p> <div class="credits"> <p class="dwt_author">Wrede, Christoph; Dreier, Anne; Heller, Christina; Reitner, Joachim; Hoppert, Michael</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">379</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24828365"> <span id="translatedtitle">3-D analysis of bacterial cell-(<span class="hlt">iron</span>)mineral aggregates formed during Fe(II) <span class="hlt">oxidation</span> by the nitrate-reducing Acidovorax sp. strain BoFeN1 using complementary microscopy tomography approaches.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The formation of cell-(<span class="hlt">iron</span>)mineral aggregates as a consequence of bacterial <span class="hlt">iron</span> <span class="hlt">oxidation</span> is an environmentally widespread process with a number of implications for processes such as sorption and coprecipitation of contaminants and nutrients. Whereas the overall appearance of such aggregates is easily accessible using 2-D microscopy techniques, the 3-D and internal structure remain obscure. In this study, we examined the 3-D structure of cell-(<span class="hlt">iron</span>)mineral aggregates formed during Fe(II) <span class="hlt">oxidation</span> by the nitrate-reducing Acidovorax sp. strain BoFeN1 using a combination of advanced 3-D microscopy techniques. We obtained 3-D structural and chemical information on different cellular encrustation patterns at high spatial resolution (4-200 nm, depending on the method): more specifically, (1) cells free of <span class="hlt">iron</span> minerals, (2) periplasm filled with <span class="hlt">iron</span> minerals, (3) spike- or platelet-shaped <span class="hlt">iron</span> mineral structures, (4) bulky structures on the cell surface, (5) extracellular <span class="hlt">iron</span> mineral shell structures, (6) cells with <span class="hlt">iron</span> mineral filled cytoplasm, and (7) agglomerations of extracellular globular structures. In addition to structural information, chemical nanotomography suggests a dominant role of extracellular polymeric substances (EPS) in controlling the formation of cell-(<span class="hlt">iron</span>)mineral aggregates. Furthermore, samples in their <span class="hlt">hydrated</span> state showed cell-(<span class="hlt">iron</span>)mineral aggregates in pristine conditions free of preparation (i.e., drying/dehydration) artifacts. All these results were obtained using 3-D microscopy techniques such as focused ion beam (FIB)/scanning electron microscopy (SEM) tomography, transmission electron microscopy (TEM) tomography, scanning transmission (soft) X-ray microscopy (STXM) tomography, and confocal laser scanning microscopy (CLSM). It turned out that, due to the various different contrast mechanisms of the individual approaches, and due to the required sample preparation steps, only the combination of these techniques was able to provide a comprehensive understanding of structure and composition of the various Fe-precipitates and their association with bacterial cells and EPS. PMID:24828365</p> <div class="credits"> <p class="dwt_author">Schmid, G; Zeitvogel, F; Hao, L; Ingino, P; Floetenmeyer, M; Stierhof, Y-D; Schroeppel, B; Burkhardt, C J; Kappler, A; Obst, M</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">380</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/23341099"> <span id="translatedtitle">Magnetic chitosan\\/<span class="hlt">iron</span> (II, III) <span class="hlt">oxide</span> nanoparticles prepared by spray-drying</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Chitosan\\/<span class="hlt">iron</span> (II, III) <span class="hlt">oxide</span> nanoparticles with various ratios of chitosan\\/<span class="hlt">iron</span> (CS1\\/Fe4, CS2\\/Fe4 and CS3\\/Fe4) were prepared by a spray-drying method. Atomic absorption spectrometry (AAS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) spectrometry data confirm that magnetic crystalline Fe3O4 interacts with chitosan and distributes in the chitosan matrix. Field emission scanning electron microscopy (FESEM) micrographs indicate that nanoparticles so</p> <div class="credits"> <p class="dwt_author">Hsin-Yi Huang; Yeong-Tarng Shieh; Chao-Ming Shih; Yawo-Kuo Twu</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a 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showDiv("page_21");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">381</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40352919"> <span id="translatedtitle">Advanced <span class="hlt">oxidation</span> of natural organic matter using hydrogen peroxide and <span class="hlt">iron</span>-coated pumice particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">oxidative</span> removal of natural organic matter (NOM) from waters using hydrogen peroxide and <span class="hlt">iron</span>-coated pumice particles as heterogeneous catalysts was investigated. Two NOM sources were tested: humic acid solution and a natural source water. <span class="hlt">Iron</span> coated pumice removed about half of the dissolved organic carbon (DOC) concentration at a dose of 3000mgl?1 in 24h by adsorption only. Original pumice</p> <div class="credits"> <p class="dwt_author">M. Kitis; S. S. Kaplan</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">382</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009ApPhA..95..373B"> <span id="translatedtitle">Synthesis and studies of growth kinetics of monodispersed <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles using ferrocene as novel precursor</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have used ferrocene and paraffin wax as novel precursor and solvent for the growth of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles. The proposed method of growth has several advantages over existing methods of growth using <span class="hlt">iron</span> pentacarbonyl a precursor. Highly crystalline and monodispersed particles are obtained which assemble in two- and three-dimensional hexagonal closed packed superlattices. Growth kinetics has been studied by varying concentration of the precursor and time of growth. A phenomenological model has been proposed to explain the growth kinetics.</p> <div class="credits"> <p class="dwt_author">Bhalerao, G. M.; Sinha, A. K.; Srivastava, Himanshu; Srivastava, A. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">383</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40122227"> <span id="translatedtitle">Authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> formation in the estuarine mixing zone of the Yangtze River</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Estuaries are elementary geochemical fronts where river water and seawater mix. Within this mixing zone, <span class="hlt">iron</span> and other non-conservative\\u000a elements can undergo complex reactions to form new solid phases. In order to understand authigenic <span class="hlt">iron</span> <span class="hlt">oxide</span> formation in\\u000a the Yangtze River Estuary, two onsite water-mixing sets of experiments were conducted, one by mixing variable amounts of unfiltered\\u000a Yangtze River water</p> <div class="credits"> <p class="dwt_author">D. J. Fan; R. D. Neuser; X. G. Sun; Z. S. Yang; Z. G. Guo; S. K. Zhai</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">384</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2265287"> <span id="translatedtitle"><span class="hlt">Iron</span> homeostasis and <span class="hlt">oxidative</span> stress in idiopathic pulmonary alveolar proteinosis: a case-control study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Lung injury caused by both inhaled dusts and infectious agents depends on increased availability of <span class="hlt">iron</span> and metal-catalyzed <span class="hlt">oxidative</span> stress. Because inhaled particles, such as silica, and certain infections can cause secondary pulmonary alveolar proteinosis (PAP), we tested the hypothesis that idiopathic PAP is associated with an altered <span class="hlt">iron</span> homeostasis in the human lung. Methods Healthy volunteers (n = 20) and patients with idiopathic PAP (n = 20) underwent bronchoalveolar lavage and measurements were made of total protein, <span class="hlt">iron</span>, tranferrin, transferrin receptor, lactoferrin, and ferritin. Histochemical staining for <span class="hlt">iron</span> and ferritin was done in the cell pellets from control subjects and PAP patients, and in lung specimens of patients without cardiopulmonary disease and with PAP. Lavage concentrations of urate, glutathione, and ascorbate were also measured as indices of <span class="hlt">oxidative</span> stress. Results Lavage concentrations of <span class="hlt">iron</span>, transferrin, transferrin receptor, lactoferrin, and ferritin were significantly elevated in PAP patients relative to healthy volunteers. The cells of PAP patients had accumulated significant <span class="hlt">iron</span> and ferritin, as well as considerable amounts of extracellular ferritin. Immunohistochemistry for ferritin in lung tissue revealed comparable amounts of this metal-storage protein in the lower respiratory tract of PAP patients both intracellularly and extracellularly. Lavage concentrations of ascorbate, glutathione, and urate were significantly lower in the lavage fluid of the PAP patients. Conclusion <span class="hlt">Iron</span> homeostasis is altered in the lungs of patients with idiopathic PAP, as large amounts of catalytically-active <span class="hlt">iron</span> and low molecular weight anti-<span class="hlt">oxidant</span> depletion are present. These findings suggest a metal-catalyzed <span class="hlt">oxidative</span> stress in the maintenance of this disease. PMID:18215276</p> <div class="credits"> <p class="dwt_author">Ghio, Andrew J; Stonehuerner, Jacqueline G; Richards, Judy H; Crissman, Kay M; Roggli, Victor L; Piantadosi, Claude A; Carraway, Martha Sue</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">385</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23291738"> <span id="translatedtitle">Ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> by sulfur-<span class="hlt">oxidizing</span> Acidithiobacillus ferrooxidans and analysis of the process at the levels of transcription and protein synthesis.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In contrast to <span class="hlt">iron-oxidizing</span> Acidithiobacillus ferrooxidans, A. ferrooxidans from a stationary phase elemental sulfur-<span class="hlt">oxidizing</span> culture exhibited a lag phase in pyrite <span class="hlt">oxidation</span>, which is similar to its behaviour during ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span>. The ability of elemental sulfur-<span class="hlt">oxidizing</span> A. ferrooxidans to immediately <span class="hlt">oxidize</span> ferrous <span class="hlt">iron</span> or pyrite without a lag phase was only observed in bacteria obtained from growing cultures with elemental sulfur. However, these cultures that shifted to ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> showed a low rate of ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> while no growth was observed. Two-dimensional gel electrophoresis was used for a quantitative proteomic analysis of the adaptation process when bacteria were switched from elemental sulfur to ferrous <span class="hlt">iron</span>. A comparison of total cell lysates revealed 39 proteins whose increase or decrease in abundance was related to this phenotypic switching. However, only a few proteins were closely related to <span class="hlt">iron</span> and sulfur metabolism. Reverse-transcription quantitative PCR was used to further characterize the bacterial adaptation process. The expression profiles of selected genes primarily involved in the ferrous <span class="hlt">iron</span> <span class="hlt">oxidation</span> indicated that phenotypic switching is a complex process that includes the activation of genes encoding a membrane protein, maturation proteins, electron transport proteins and their regulators. PMID:23291738</p> <div class="credits"> <p class="dwt_author">Kucera, Jiri; Bouchal, Pavel; Lochman, Jan; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">386</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/59244211"> <span id="translatedtitle">Density Functional Theory Calculations on <span class="hlt">Hydrated</span> Dimethylarsinic Acid and <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Clusters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Dimethylarsinic Acid (DMA) or (CH3)2AsO2H is an important organoarsenical compound detected in arsenic speciation studies of environmental samples and synthesized during pyrolysis of oil shale. DMA was used historically as a herbicide on large agricultural fields and can be detected in the leachates of landfills rich in waste containing arsenic such as glass, alloys, and semiconductors, as well as biologically</p> <div class="credits"> <p class="dwt_author">Adrian Adamescu</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">387</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://scholars.wlu.ca/etd/1125"> <span id="translatedtitle">Density Functional Theory Calculations on <span class="hlt">Hydrated</span> Dimethylarsinic Acid and <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Clusters.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">??Dimethylarsinic Acid (DMA) or (CH3)2AsO2H is an important organoarsenical compound detected in arsenic speciation studies of environmental samples and synthesized during pyrolysis of oil shale.… (more)</p> <div class="credits"> <p class="dwt_author">Adamescu, Adrian</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">388</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25590575"> <span id="translatedtitle">Noncovalent magnetic control and reversible recovery of graphene <span class="hlt">oxide</span> using <span class="hlt">iron</span> <span class="hlt">oxide</span> and magnetic surfactants.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The unique charging properties of graphene <span class="hlt">oxide</span> (GO) are exploited in the preparation of a range of noncovalent magnetic GO materials, using microparticles, nanoparticles, and magnetic surfactants. Adsorption and desorption are controlled by modification of pH within a narrow window of <2 pH units. The benefit conferred by using charge-based adsorption is that the process is reversible, and the GO can be captured and separated from the magnetic nanomaterial, such that both components can be recycled. <span class="hlt">Iron</span> <span class="hlt">oxide</span> (Fe2O3) microparticles form a loosely flocculated gel network with GO, which is demonstrated to undergo magnetic compressional dewatering in the presence of an external magnetic field. For composites formed from GO and Fe2O3 nanoparticles, it is found that low Fe2O3:GO mass ratios (<5:1) favor flocculation of GO, whereas higher ratios (>5:1) cause overcharging of the surfaces resulting in restabilization. The effectiveness of the GO adsorption and magnetic capture process is demonstrated by separating traditionally difficult-to-recover gold nanoparticles (d ? 10 nm) from water. The fully recyclable nature of the assembly and capture process, combined with the vast adsorption capacity of GO, presents obvious and appealing advantages for applications in decontamination and water treatment. PMID:25590575</p> <div class="credits"> <p class="dwt_author">McCoy, Thomas M; Brown, Paul; Eastoe, Julian; Tabor, Rico F</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-28</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">389</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004cosp...35..222R"> <span id="translatedtitle"><span class="hlt">Iron</span>-sulfides, <span class="hlt">iron-oxides</span> and aqueous processing of organic materials in CM and CI meteorites and IDPs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Why do CM meteorites have such a rich variety of organics? D/H isotope ratios prove an interstellar component of the organic matter in CM and CI carbonaceous meteorites wherein the complex ``organics'' could in part be due to Fischer-Tropsch type (FTT) processes and processing of organic precursors on Fe-sulfide, Fe-<span class="hlt">oxide</span> or clay catalysts. ``Origin of Life'' scenarios refer to the richly varied organics in CM (Murchison) meteorites as the precursor materials delivered to the Earth 4.2-3.9 Gyrs ago. Aggregate interplanetary dust particles (IDPs) have more carbon, incl. an interstellar component, than CI and CM meteorites but their original ``organics'' and amounts are modified by pyrolysis during atmospheric entry. Here, I will assume that anhydrous aggregate IDPs formed the originally anhydrous CI and CM matrix. These IDPs contain submicron CHON, mixed and `silicate' principal components (PCs), e.g. Fe-rich serpentine dehydroxylate, (Mg,Fe)3Si2O7, PCs [Fe/(Mg+Fe)(fe) = 0.3-0.8], and micron-size Fe-sulfides, olivine and pyroxenes. In a Mg-Fe-Si diagram with an Fe-apex, these PC compositions plot on a serpentine, (Mg,Fe)/Si line. The <span class="hlt">hydrated</span> CI matrix compositions also define a straight line that, anchored at serpentine, fe = 0.3, is rotated towards higher (Mg,Fe)/Si ratios with increasing serpentine fe-ratio when during <span class="hlt">hydration</span> of an initially ``serpentine dehydroxylate PC'' CI matrix reacted with Fe-sulfide, Fe-<span class="hlt">oxide</span>, or both. The straight line defining <span class="hlt">hydrated</span> CM matrix compositions is rotated even more towards higher (Mg,Fe)/Si ratios when <span class="hlt">hydrated</span> CI-like material continued reacting with Fe-<span class="hlt">oxide</span> and Fe-sulfide and formed tochilinite, a mineral unique to CM meteorites. Continuous <span class="hlt">hydration</span> of IDP-like material with an ample supply of Fe-minerals acting as catalysts for formation and processing ``organics'' would have affected the redox conditions of a buffered C-H-O-S aqueous fluid during the time ``organics' were modified to the unique mélanges of CM protoplanets. Of all meteors with masses decreasing from (0.1 - 2x103 kg) to (2x10-8 - 5x10-6) kg, 22% up to 39% were ``regular cometary material' [Ceplecha et al., 1998, Space Sci. Revs. 84: 327-471]. This mass range covers small boulders ˜ 1 m in size to dust that might represent the building blocks of comet nucleus rubble piles that have yet to be identified. When they included CI and CM-like materials, comets might harbor processed complex ``organics'' with unprocessed (presolar) organics preserved in the dirty-ice/icy-dirt. `Origin of Life' discussions ought to consider periodic comets as a resource to study solar system processing of pristine organics.</p> <div class="credits"> <p class="dwt_author">Rietmeijer, F. J.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">390</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3282478"> <span id="translatedtitle">Toward a Mechanistic Understanding of Anaerobic Nitrate-Dependent <span class="hlt">Iron</span> <span class="hlt">Oxidation</span>: Balancing Electron Uptake and Detoxification</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The anaerobic <span class="hlt">oxidation</span> of Fe(II) by subsurface microorganisms is an important part of biogeochemical cycling in the environment, but the biochemical mechanisms used to couple <span class="hlt">iron</span> <span class="hlt">oxidation</span> to nitrate respiration are not well understood. Based on our own work and the evidence available in the literature, we propose a mechanistic model for anaerobic nitrate-dependent <span class="hlt">iron</span> <span class="hlt">oxidation</span>. We suggest that anaerobic <span class="hlt">iron-oxidizing</span> microorganisms likely exist along a continuum including: (1) bacteria that inadvertently <span class="hlt">oxidize</span> Fe(II) by abiotic or biotic reactions with enzymes or chemical intermediates in their metabolic pathways (e.g., denitrification) and suffer from toxicity or energetic penalty, (2) Fe(II) tolerant bacteria that gain little or no growth benefit from <span class="hlt">iron</span> <span class="hlt">oxidation</span> but can manage the toxic reactions, and (3) bacteria that efficiently accept electrons from Fe(II) to gain a growth advantage while preventing or mitigating the toxic reactions. Predictions of the proposed model are highlighted and experimental approaches are discussed. PMID:22363331</p> <div class="credits"> <p class="dwt_author">Carlson, Hans K.; Clark, Iain C.; Melnyk, Ryan A.; Coates, John D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">391</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21126142"> <span id="translatedtitle">Reduction of <span class="hlt">iron-oxide</span>-carbon composites: part I. Estimation of the rate constants</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A new ironmaking concept using <span class="hlt">iron-oxide</span>-carbon composite pellets has been proposed, which involves the combination of a rotary hearth furnace (RHF) and an <span class="hlt">iron</span> bath smelter. This part of the research focuses on studying the two primary chemical kinetic steps. Efforts have been made to experimentally measure the kinetics of the carbon gasification by CO{sub 2} and wustite reduction by CO by isolating them from the influence of heat- and mass-transport steps. A combined reaction model was used to interpret the experimental data and determine the rate constants. Results showed that the reduction is likely to be influenced by the chemical kinetics of both carbon <span class="hlt">oxidation</span> and wustite reduction at the temperatures of interest. Devolatilized wood-charcoal was observed to be a far more reactive form of carbon in comparison to coal-char. Sintering of the <span class="hlt">iron-oxide</span> at the high temperatures of interest was found to exert a considerable influence on the reactivity of wustite by virtue of altering the internal pore surface area available for the reaction. Sintering was found to be predominant for highly porous <span class="hlt">oxides</span> and less of an influence on the denser ores. It was found using an indirect measurement technique that the rate constants for wustite reduction were higher for the porous <span class="hlt">iron-oxide</span> than dense hematite ore at higher temperatures (> 1423 K). Such an indirect mode of measurement was used to minimize the influence of sintering of the porous <span class="hlt">oxide</span> at these temperatures.</p> <div class="credits"> <p class="dwt_author">Halder, S.; Fruehan, R.J. [Praxair Inc., Tonawanda, NY (United States). Technological Center</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">392</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008MMTB...39..784H"> <span id="translatedtitle">Reduction of <span class="hlt">Iron-Oxide</span>-Carbon Composites: Part I. Estimation of the Rate Constants</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A new ironmaking concept using <span class="hlt">iron-oxide</span>-carbon composite pellets has been proposed, which involves the combination of a rotary hearth furnace (RHF) and an <span class="hlt">iron</span> bath smelter. This part of the research focuses on studying the two primary chemical kinetic steps. Efforts have been made to experimentally measure the kinetics of the carbon gasification by CO2 and wüstite reduction by CO by isolating them from the influence of heat- and mass-transport steps. A combined reaction model was used to interpret the experimental data and determine the rate constants. Results showed that the reduction is likely to be influenced by the chemical kinetics of both carbon <span class="hlt">oxidation</span> and wüstite reduction at the temperatures of interest. Devolatilized wood-charcoal was observed to be a far more reactive form of carbon in comparison to coal-char. Sintering of the <span class="hlt">iron-oxide</span> at the high temperatures of interest was found to exert a considerable influence on the reactivity of wüstite by virtue of altering the internal pore surface area available for the reaction. Sintering was found to be predominant for highly porous <span class="hlt">oxides</span> and less of an influence on the denser ores. It was found using an indirect measurement technique that the rate constants for wüstite reduction were higher for the porous <span class="hlt">iron-oxide</span> than dense hematite ore at higher temperatures (>1423 K). Such an indirect mode of measurement was used to minimize the influence of sintering of the porous <span class="hlt">oxide</span> at these temperatures.</p> <div class="credits"> <p class="dwt_author">Halder, S.; Fruehan, R. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">393</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AcSpA..76...74H"> <span id="translatedtitle"><span class="hlt">Iron-oxide</span> aerogel and xerogel catalyst formulations: Characterization by 57Fe Mössbauer and XAFS spectroscopies</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Iron</span> in various <span class="hlt">iron-oxide</span> aerogel and xerogel catalyst formulations (?85% Fe 2O 3; ?10% K, Co, Cu, or Pd) developed for possible use in Fischer-Tropsch synthesis (FTS) or the water-gas-shift (WGS) reaction has been examined by 57Fe Mössbauer spectroscopy. The seventeen samples consisted of both as-prepared and calcined aerogels and xerogels and their products after use as catalysts for FTS or the WGS reaction. Complementary XAFS spectra were obtained on the occurrence of the secondary elements in some of the same materials. A broad, slightly asymmetric, two-peak Mössbauer spectrum was obtained from the different as-prepared and calcined catalyst formulations in the majority of cases. Such spectra could only be satisfactorily fit with three quadrupole doublet components, but no systematic trends in the isomer shift and quadrupole splitting parameters and area ratios of the individual components could be discerned that reflected variations in the composition or preparation of the aerogel or xerogel materials. However, significant reductions were noted in the Mössbauer effective thickness (recoilless absorption effect per unit mass of <span class="hlt">iron</span>) parameter, ?eff/ g, determined at room temperature, for aerogels and xerogels compared to bulk <span class="hlt">iron</span> <span class="hlt">oxides</span>, reflecting the openness and lack of rigidity of the aerogel and xerogel structures. Mössbauer measurements for two aerogels over the range from 15 to 292 K confirmed the greatly diminished nature of this parameter at room temperature. Major increases in the effective thickness parameter were observed when the open structure of the aerogel or xerogel collapsed during calcination resulting in the formation of <span class="hlt">iron</span> <span class="hlt">oxides</span> (hematite, spinel ferrite). Similar structural changes were indicated by increases in this parameter after use of <span class="hlt">iron-oxide</span> aerogels as catalysts for FTS or the WGS reaction, during which the <span class="hlt">iron-oxide</span> aerogel was converted to a mixture of nonstoichiometric magnetite and the Hägg carbide, ?-Fe 5C 2, or nonstoichiometric magnetite, respectively.</p> <div class="credits"> <p class="dwt_author">Huggins, Frank E.; Bali, Sumit; Huffman, Gerald P.; Eyring, Edward M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">394</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2754497"> <span id="translatedtitle">Extending the models for <span class="hlt">iron</span> and sulfur <span class="hlt">oxidation</span> in the extreme Acidophile Acidithiobacillus ferrooxidans</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Acidithiobacillus ferrooxidans gains energy from the <span class="hlt">oxidation</span> of ferrous <span class="hlt">iron</span> and various reduced inorganic sulfur compounds at very acidic pH. Although an initial model for the electron pathways involved in <span class="hlt">iron</span> <span class="hlt">oxidation</span> has been developed, much less is known about the sulfur <span class="hlt">oxidation</span> in this microorganism. In addition, what has been reported for both <span class="hlt">iron</span> and sulfur <span class="hlt">oxidation</span> has been derived from different A. ferrooxidans strains, some of which have not been phylogenetically characterized and some have been shown to be mixed cultures. It is necessary to provide models of <span class="hlt">iron</span> and sulfur <span class="hlt">oxidation</span> pathways within one strain of A. ferrooxidans in order to comprehend the full metabolic potential of the pangenome of the genus. Results Bioinformatic-based metabolic reconstruction supported by microarray transcript profiling and quantitative RT-PCR analysis predicts the involvement of a number of novel genes involved in <span class="hlt">iron</span> and sulfur <span class="hlt">oxidation</span> in A. ferrooxidans ATCC23270. These include for <span class="hlt">iron</span> <span class="hlt">oxidation</span>: cup (copper oxidase-like), ctaABT (heme biogenesis and insertion), nuoI and nuoK (NADH complex subunits), sdrA1 (a NADH complex accessory protein) and atpB and atpE (ATP synthetase F0 subunits). The following new genes are predicted to be involved in reduced inorganic sulfur compounds <span class="hlt">oxidation</span>: a gene cluster (rhd, tusA, dsrE, hdrC, hdrB, hdrA, orf2, hdrC, hdrB) encoding three sulfurtransferases and a heterodisulfide reductase complex, sat potentially encoding an ATP sulfurylase and sdrA2 (an accessory NADH complex subunit). Two different regulatory components are predicted to be involved in the regulation of alternate electron transfer pathways: 1) a gene cluster (ctaRUS) that contains a predicted <span class="hlt">iron</span> responsive regulator of the Rrf2 family that is hypothesized to regulate cytochrome aa3 oxidase biogenesis and 2) a two component sensor-regulator of the RegB-RegA family that may respond to the redox state of the quinone pool. Conclusion Bioinformatic analysis coupled with gene transcript profiling extends our understanding of the <span class="hlt">iron</span> and reduced inorganic sulfur compounds <span class="hlt">oxidation</span> pathways in A. ferrooxidans and suggests mechanisms for their regulation. The models provide unified and coherent descriptions of these processes within the type strain, eliminating previous ambiguity caused by models built from analyses of multiple and divergent strains of this microorganism. PMID:19703284</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">395</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.princeton.edu/morel/publications/pdfs/waiteEST1984.pdf"> <span id="translatedtitle">Environ. Scl. Technol. W84, 18, 860-868 Photoreductive Dissolution of Colloidal <span class="hlt">Iron</span> <span class="hlt">Oxides</span> in Natural Waters</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">and <span class="hlt">oxide</span>-bound ferric citrate complexes and the known photoactivity of soluble <span class="hlt">iron</span>- fulvic acid groups (II/or dissolutionof colloidaliron <span class="hlt">oxides</span> (8). All of these natural water studies have been performed in acidic lakes</p> <div class="credits"> <p class="dwt_author">Morel, François M. M.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">396</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JNuM..448..420T"> <span id="translatedtitle">Advanced <span class="hlt">oxidation</span>-resistant <span class="hlt">iron</span>-based alloys for LWR fuel cladding</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Application of advanced <span class="hlt">oxidation</span>-resistant <span class="hlt">iron</span> alloys as light water reactor fuel cladding is proposed. The motivations are based on specific limitations associated with zirconium alloys, currently used as fuel cladding, under design-basis and beyond-design-basis accident scenarios. Using a simplified methodology, gains in safety margins under severe accidents upon transition to advanced <span class="hlt">oxidation</span>-resistant <span class="hlt">iron</span> alloys as fuel cladding are showcased. <span class="hlt">Oxidation</span> behavior, mechanical properties, and irradiation effects of advanced <span class="hlt">iron</span> alloys are briefly reviewed and compared to zirconium alloys as well as historic austenitic stainless steel cladding materials. Neutronic characteristics of <span class="hlt">iron</span>-alloy-clad fuel bundles are determined and fed into a simple economic model to estimate the impact on nuclear electricity production cost. Prior experience with steel cladding is combined with the current understanding of the mechanical properties and irradiation behavior of advanced <span class="hlt">iron</span> alloys to identify a combination of cladding thickness reduction and fuel enrichment increase (?0.5%) as an efficient route to offset any penalties in cycle length, due to higher neutron absorption in the <span class="hlt">iron</span> alloy cladding, with modest impact on the economics.</p> <div class="credits"> <p class="dwt_author">Terrani, K. A.; Zinkle, S. J.; Snead, L. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">397</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006ApPhL..88d3105L"> <span id="translatedtitle">Magnetic nanocables—Silicon carbide sheathed with <span class="hlt">iron-oxide</span>-doped amorphous silica</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">High-purity nanocables of <span class="hlt">iron</span>-containing amorphous-silica-sheathed silicon carbide were synthesized by a thermal reaction method using silicon wafer as the silicon source and growth substrate, and ferrocene as the carbon and <span class="hlt">iron</span> catalyst precursor. The nanocables were tens of ?m in length and 40-60nm in diameter. <span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles with a mean diameter of 5nm were dispersed evenly in the amorphous silica layer. The nanocables were found to be ferromagnetic at both 10K and room temperature, which indicates that they may have important potential applications in electromagnetic nanodevices.</p> <div class="credits"> <p class="dwt_author">Liu, C.; Li, R. W.; Belik, A.; Golberg, D.; Bando, Y.; Cheng, H. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">398</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24187645"> <span id="translatedtitle">The effect of gold and <span class="hlt">iron-oxide</span> nanoparticles on biofilm-forming pathogens.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Microbial biofilms on biomaterial implants or devices are hard to eliminate by antibiotics due to their protection by exopolymeric substances that embed the organisms in a matrix, impenetrable for most antibiotics and immune-cells. Application of metals in their nanoparticulated form is currently considered to resolve bacterial infections. Gold and <span class="hlt">iron-oxide</span> nanoparticles are widely used in different medical applications, but their utilisation to eradicate biofilms on biomaterials implants is novel. Here, we studied the effect of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles on Staphylococcus aureus and Pseudomonas aeruginosa biofilms. We report that biofilm growth was reduced at higher concentrations of gold and <span class="hlt">iron-oxide</span> nanoparticles compared to absence of nanoparticles. Thus nanoparticles with appropriate concentration could show significant reduction in biofilm formation. PMID:24187645</p> <div class="credits"> <p class="dwt_author">Sathyanarayanan, Madhu Bala; Balachandranath, Reneta; Genji Srinivasulu, Yuvasri; Kannaiyan, Sathish Kumar; Subbiahdoss, Guruprakash</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">399</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2733941"> <span id="translatedtitle">Photoinitiated Coupling of Unmodified Monosaccharides to <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Nanoparticles for Sensing Proteins and Bacteria</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">We report a versatile approach for the immobilization of unmodified monosaccharides onto <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles. Covalent coupling of the carbohydrate onto <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle surfaces was accomplished by the CH insertion reaction of photochemically activated phosphate-functionalized perfluorophenylazides (PFPAs), and the resulting glyconanoparticles were characterized by IR, TGA, and TEM. The surface-bound d-mannose showed the recognition ability towards Concanavalin A and Escherichia coli strain ORN178 that possesses mannose-specific receptor sites. Owing to the simplicity and versatility of the technique, together with the magnetic property of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles, the methodology developed in this study serves as a general approach for the preparation of magnetic glyconanoparticles to be used in clinical diagnosis, sensing, and de-contamination. PMID:19534519</p> <div class="credits"> <p class="dwt_author">Liu, Li-Hong; Dietsch, Hervé; Schurtenberger, Peter; Yan, Mingdi</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">400</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24094173"> <span id="translatedtitle">Synthesis and characterization of PEG-<span class="hlt">iron</span> <span class="hlt">oxide</span> core-shell composite nanoparticles for thermal therapy.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In this study, core-shell nanoparticles were developed to achieve thermal therapy that can ablate cancer cells in a remotely controlled manner. The core-shell nanoparticles were prepared using atomic transfer radical polymerization (ATRP) to coat <span class="hlt">iron</span> <span class="hlt">oxide</span> (Fe3O4) nanoparticles with a poly(ethylene glycol) (PEG) based polymer shell. The <span class="hlt">iron</span> <span class="hlt">oxide</span> core allows for the remote heating of the particles in an alternating magnetic field (AMF). The coating of <span class="hlt">iron</span> <span class="hlt">oxide</span> with PEG was verified through Fourier transform infrared spectroscopy and thermal gravimetric analysis. A thermoablation (55°C) study was performed on A549 lung carcinoma cells exposed to nanoparticles and over a 10 min AMF exposure. The successful thermoablation of A549 demonstrates the potential use of polymer coated particles for thermal therapy. PMID:24094173</p> <div class="credits"> <p class="dwt_author">Wydra, Robert J; Kruse, Anastasia M; Bae, Younsoo; Anderson, Kimberly W; Hilt, J Zach</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">401</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007SPIE.6441E..1TP"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles as drug delivery agents in MIA PaCa-2 pancreatic cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Oleic acid (OA)-Pluronic-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles were synthesized and characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Atomic Force Microscopy (AFM). FT-IR confirmed the bonding of oleic acid and Pluronic (surfactant) to the nanoparticles. AFM measurements on these nanoparticles indicated a root mean square (RMS) roughness, a measure of nanoparticle size of (50 +/- 20) nm. The efficiency of these functionalized nanoparticles was investigated by loading with 5-Fluorouracil (5-FU) in aqueous solution. AFM measurements were used to characterize modified <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles and pancreatic MIA PaCa-2 cells, including size distribution, stability and cellular uptake. Nanoparticles were added to MIA PaCa-2 cells and assayed for their cytotoxic effects after 24 and 48 hours. The outcome of this study demonstrated the effectiveness of oleic acid (OA)-Pluronic-coated <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles as a non-toxic drug delivery agent for pancreatic cancer.</p> <div class="credits"> <p class="dwt_author">Perry, Christopher; Randriamahefa, Alexandrine; Lokko, Carl; Evans, Whitney; Watkins, Julian; Carrell, Holly; King, Natalie; Patel, Darayas</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">402</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013ApSS..281...60M"> <span id="translatedtitle">Magnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles as drug delivery system in breast cancer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Present work was focused on producing improved <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles for targeted drug delivery in breast cancer. Nanometric-sized <span class="hlt">iron</span> <span class="hlt">oxide</span> particles were synthesized by laser pyrolysis and were morphologically/structurally characterized. These new nanoparticles were compared with some commercial, chemically prepared <span class="hlt">iron</span> <span class="hlt">oxide</span> ones. Cytotoxicity and the anti-proliferation effects of nanoparticles were tested in vitro on the breast adenocarcinoma cell line MCF-7. Nanoparticles were further coated with the antracyclinic antibiotic Violamycine B1 and tested for the anti-tumor effect on MCF-7 cells. The nanoparticles produced by us seem more effective in vitro than the commercial ones, with respect to cellular uptake and VB1 delivery. Violamycine B1 bound on nanoparticles is as efficient as the free form, but is better delivered into tumor cells.</p> <div class="credits"> <p class="dwt_author">Marcu, A.; Pop, S.; Dumitrache, F.; Mocanu, M.; Niculite, C. M.; Gherghiceanu, M.; Lungu, C. P.; Fleaca, C.; Ianchis, R.; Barbut, A.; Grigoriu, C.; Morjan, I.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">403</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20814119"> <span id="translatedtitle"><span class="hlt">Oxidative</span> stress in hemodialysis patients receiving intravenous <span class="hlt">iron</span> therapy and the role of N-acetylcysteine in preventing <span class="hlt">oxidative</span> stress.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">To determine the contribution of injectable <span class="hlt">iron</span> administered to hemodialysis (HD) patients in causing <span class="hlt">oxidative</span> stress and the beneficial effect of N-acetylcysteine (NAC) in reducing it, we studied in a prospective, double blinded, randomized controlled, cross over trial 14 adult HD patients who were randomized into two groups; one group received NAC in a dose of 600 mgs twice daily for 10 days prior to intravenous <span class="hlt">iron</span> therapy and the other group received placebo. Both the groups were subjected to intravenous <span class="hlt">iron</span> therapy, 100 mg of <span class="hlt">iron</span> sucrose in 100 mL of normal saline given over a period of one hour. Blood samples for the markers of <span class="hlt">oxidative</span> stress were taken before and after <span class="hlt">iron</span> therapy. After the allowance of a week of wash out period for the effect of N-acetylcysteine we crossed over the patients to the opposite regimen. We measured the lipid peroxidation marker, malondiaaldehyde (MDA), to evaluate the <span class="hlt">oxidative</span> stress and total anti-<span class="hlt">oxidant</span> capacity (TAC) for the antioxidant level in addition to the highly sensitive C-reactive protein (HsCRP). Non-invasive assessment of endothelial dysfunction was measured by digital plethysmography before and after intravenous <span class="hlt">iron</span> therapy. There was an increase of MDA (21.97 + 3.65% vs 7.06 + 3.65%) and highly sensitive C-reactive protein (HsCRP) (11.19 + 24.63% vs 13.19 + 7.7%) after <span class="hlt">iron</span> administration both in the placebo and the NAC groups. NAC reduced the baseline acute systemic generation of <span class="hlt">oxidative</span> stress when compared to placebo, which was statistically significant with MDA (12.76 + 4.4% vs 9.37 + 4.40%: P = 0.032) but not with HsCRP though there was a declining trend (2.85 + 22.75 % vs 8.93 + 5.19%: P = 0.112). Pre-treatment with NAC reduced the endothelial dysfunction when compared to placebo, but it was not statistically significant, except for reflection index (RI). We conclude that in our HD patients NAC reduced the <span class="hlt">oxidative</span> stress before and after the administration of intravenous <span class="hlt">iron</span> therapy in addition to the endothelial dysfunction induced by this treatment. PMID:20814119</p> <div class="credits"> <p class="dwt_author">Swarnalatha, G; Ram, R; Neela, Prasad; Naidu, M U R; Dakshina Murty, K V</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">404</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22884880"> <span id="translatedtitle"><span class="hlt">Iron</span> increases liver injury through <span class="hlt">oxidative</span>/nitrative stress in diabetic rats: Involvement of nitrotyrosination of glucokinase.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Excessive tissue <span class="hlt">iron</span> levels are associated with the increase of <span class="hlt">oxidative</span>/nitrative stress which contributes to tissue damage that may elevate the risk of diabetes. Therefore, we investigated the effects of <span class="hlt">iron</span> on diabetes-associated liver injury and whether <span class="hlt">iron</span>-related tyrosine nitration participated in this process. Rats were randomly divided into four groups: control, <span class="hlt">iron</span> overload (300 mg/kg <span class="hlt">iron</span> dextran, i.p.), diabetic (35 mg/kg of streptozotocin i.p. after administration of a high-fat diet) and diabetic simultaneously treated with <span class="hlt">iron</span>. <span class="hlt">Iron</span> supplement markedly increased diabetes-mediated liver damage and hepatic dysfunction by increasing liver/body weight ratio, serum levels of aspartate and alanine aminotransferase, and histological examination, which were correlated with elevated levels of lipid peroxidation, protein carbonyls and tyrosine nitration, <span class="hlt">oxidative</span> metabolism of nitric <span class="hlt">oxide</span>, and reduced antioxidant capacity. Consequently, the extent of <span class="hlt">oxidized</span>/nitrated glucokinase was markedly increased in the <span class="hlt">iron</span>-treated diabetic rats that contribute to a decrease in its expression and activity. Further studies revealed a significant contribution of <span class="hlt">iron</span>-induced specific glucokinase nitration sites to its inactivation. In conclusion, <span class="hlt">iron</span> facilitates diabetes-mediated elevation of <span class="hlt">oxidative</span>/nitrative stress, simultaneously impairs liver GK, and can be a link between enzymatic changes and hepatic dysfunction. These findings may provide new insight on the role of <span class="hlt">iron</span> in the pathogenesis of diabetes mellitus. PMID:22884880</p> <div class="credits"> <p class="dwt_author">Li, Xueli; Li, Hailing; Lu, Naihao; Feng, Yunchao; Huang, Yi; Gao, Zhonghong</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">405</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.7252B"> <span id="translatedtitle">The life cycle of <span class="hlt">iron</span> Fe(III) <span class="hlt">oxide</span>: impact of fungi and bacteria</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxides</span> are ubiquitous reactive constituents of soils, sediments and aquifers. They exhibit vast surface areas which bind a large array of trace metals, nutrients and organic molecules hence controlling their mobility/reactivity in the subsurface. In this context, understanding the "life cycle" of <span class="hlt">iron</span> <span class="hlt">oxide</span> in soils is paramount to many biogeochemical processes. Soils environments are notorious for their extreme heterogeneity and variability of chemical, physical conditions and biological agents at play. Here, we present studies investigating the role of two biological agents driving <span class="hlt">iron</span> <span class="hlt">oxide</span> dynamics in soils, root-associated fungi (mycorrhiza) and bacteria. Mycorrhiza filaments (hypha) grow preferentially around, and on the surface of nutrient-rich minerals, making mineral-fungi contact zones, hot-spots of chemical alteration in soils. However, because of the microscopic nature of hyphae (only ~ 5 µm wide for up to 1 mm long) and their tendency to strongly adhere to mineral surface, in situ observations of this interfacial micro-environment are scarce. In a microcosm, ectomycorrhiza (Paxillus involutus) was grown symbiotically with a pine tree (Pinus sylvestris) in the presence of freshly-cleaved biotite under humid, yet undersaturated, conditions typical of soils. Using spatially-resolved ion milling technique (FIB), transmission electron microscopy and spectroscopy (TEM/STEM-EDS), synchrotron based X-ray microscopy (STXM), we were able to quantify the speciation of Fe at the biotite-hypha interface. The results shows that substantial <span class="hlt">oxidation</span> of biotite structural-Fe(II) into Fe(III) subdomains occurs at the contact zone between mycorrhiza and biotite. Once formed, <span class="hlt">iron</span>(III) <span class="hlt">oxides</span> can reductively dissolve under suboxic conditions via several abiotic and microbial pathways. In particular, they serve as terminal electron acceptors for the <span class="hlt">oxidation</span> of organic matter by <span class="hlt">iron</span> reducing bacteria. We aimed here to understand the role of Fe(III) mineral properties, in particular the influence of solubility, in the kinetics of microbial <span class="hlt">iron</span> reduction. We used the facultative anaerobic gram-positive bacterium Shewanella putrefaciens as model <span class="hlt">iron</span> reducing bacterium, with several ferrihydrite, hematite, goethite or lepidocrocite as electron acceptor, and lactate as electron donor. Maximum microbial Fe(III) reduction rates and solubility of Fe(III) phases were found to positively correlated in a Linear Free Energy Relationship suggesting a rate limitation by the electron transfer between <span class="hlt">iron</span> reductases and a Fe(III) center, or by the subsequent desorption of Fe2+ from the <span class="hlt">iron</span> <span class="hlt">oxide</span> mineral surface.</p> <div class="credits"> <p class="dwt_author">Bonneville, Steeve</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">406</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1019733"> <span id="translatedtitle">Gold-Coated Cementite Nanoparticles: An <span class="hlt">Oxidation</span>-Resistant Alternative to -<span class="hlt">Iron</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Iron</span>-based nanoparticles are desirable for many applications because of their magnetic properties and inherent biocompatibility. Metallic <span class="hlt">iron</span>, or {alpha}-Fe, is the most sought after because of its high saturation magnetization (up to 220 emu/g). This magnetization in <span class="hlt">iron</span> nanoparticles is difficult to reach or maintain because of the ease of <span class="hlt">oxidation</span>, which greatly reduces the magnetization values (90 emu/g or less). Here, we report the synthesis of an <span class="hlt">iron</span>-based nanoparticle comprising a magnetic cementite core (Fe{sub 3}C) that is more <span class="hlt">oxidation</span>-resistant than {alpha}-Fe, an <span class="hlt">oxide</span> layer, and a gold coating for passivation and easy functionalization. The nanoparticle structure was confirmed via X-ray absorption fine structure and Moessbauer experiments, and morphology was confirmed using transmission electron microscopy. Magnetic characterization yielded a saturation magnetization of 110 emu/g, thus demonstrating cementite as more stable alternative to {alpha}-Fe with higher magnetic moments than the <span class="hlt">iron</span> <span class="hlt">oxides</span>.</p> <div class="credits"> <p class="dwt_author">Shultz, M.; Calvin, S; Gonzalez-Jimenez, F; Mujica, V; Alleluia, B; Carpenter, E</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">407</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17662375"> <span id="translatedtitle">Fenton-like <span class="hlt">oxidation</span> of 2,4,6-trinitrotoluene using different <span class="hlt">iron</span> minerals.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Degradation of 2,4,6-trinitrotoluene (TNT) was investigated in presence of different <span class="hlt">oxidants</span> (Fenton's reagent, sodium persulfate, peroxymonosulfate and potassium permanganate) and different <span class="hlt">iron</span> minerals (ferrihydrite, hematite, goethite, lepidocrocite, magnetite and pyrite) either in aqueous solution or in soil slurry systems. Fenton's reagent was the only <span class="hlt">oxidant</span> able to degrade TNT in solution (k(app)=0.0348 min(-1)). When using <span class="hlt">iron</span> <span class="hlt">oxide</span> as heterogeneous catalyst at pH 3, specific reaction rate constants per surface area were k(surf)=1.47.10(-3) L min(-1) m(-2) and k(surf)=0.177 L min(-1) m(-2) for magnetite and pyrite, respectively while ferric <span class="hlt">iron</span> minerals were inefficient for TNT degradation. The major asset of <span class="hlt">iron</span> mineral catalyzed Fenton-like treatment has been the complete <span class="hlt">oxidation</span> of the pollutant avoiding the accumulation of possible toxic by-products. In soil slurry systems, 38% abatement of the initial TNT concentration (2 g/kg) was reached after 24 h treatment time at neutral pH. Rate limiting steps were the availability of soluble <span class="hlt">iron</span> at neutral pH together with desorption of the TNT fraction sorbed on the clay mineral surfaces. PMID:17662375</p> <div class="credits"> <p class="dwt_author">Matta, Roger; Hanna, Khalil; Chiron, Serge</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-10-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">408</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24991655"> <span id="translatedtitle"><span class="hlt">Iron</span> <span class="hlt">oxide</span> nanoparticles stabilized with dendritic polyglycerols as selective MRI contrast agents.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Monodisperse small <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles functionalized with dendritic polyglycerol (dPG) or dendritic polyglycerol sulfate (dPGS) are prepared. They are highly stable in aqueous solutions as well as physiological media. In particular, oleic acid capped <span class="hlt">iron</span> <span class="hlt">oxide</span> particles (core diameter = 11 ± 1 nm) were modified by a ligand exchange process in a one pot synthesis with dPG and dPGS bearing phosphonate as anchor groups. Dynamic light scattering measurements performed in water and different biological media demonstrate that the hydrodynamic diameter of the particles is only slightly increased by the ligand exchange process resulting in a final diameter of less than 30 nm and that the particles are stable in these media. It is also revealed by magnetic resonance studies that their magnetic relaxivity is reduced by the surface modification but it is still sufficient for high contrast magnetic resonance imaging (MRI). Additionally, incubation of dPGS functionalized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles with human umbilical vein endothelial cells showed a 50% survival at 85 nM (concentration of nanoparticles). Surface plasmon resonance (SPR) studies demonstrate that the dPGS functionalized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles inhibit L-selectin ligand binding whereas the particles containing only dPG do not show this effect. Experiments in a flow chamber with human myelogenous leukemia cells confirmed L-selectin inhibition of the dPGS functionalized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles and with that the L-selectin mediated leukocyte adhesion. These results indicate that dPGS functionalized <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles are a promising contrast agent for inflamed tissue probed by MRI. PMID:24991655</p> <div class="credits"> <p class="dwt_author">Nordmeyer, Daniel; Stumpf, Patrick; Gröger, Dominic; Hofmann, Andreas; Enders, Sven; Riese, Sebastian B; Dernedde, Jens; Taupitz, Matthias; Rauch, Ursula; Haag, Rainer; Rühl, Eckart; Graf, Christina</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-21</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">409</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.P11B1820P"> <span id="translatedtitle">Textural and Mineralogical Characteristics of Microbial Fossils in Modern and Ancient <span class="hlt">Iron</span> (oxyhydr)<span class="hlt">oxides</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Jurassic Brushy Basin Member of the Morrison Formation contains extensive alkaline saline lacustrine deposits rich in diagenetic <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxides</span> that are well exposed on the Colorado Plateau of the southwestern USA. These early diagenetic <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> minerals are associated with preserved diatoms and other algal forms, identified via scanning electron microscope (SEM) in thin sections of representative samples. The minerals are also associated with macroscopic bioturbation features (e.g., charophytes, burrows and fossilized dinosaur bones). Algal forms with cellular elaboration are identified by HF dissolution of bioturbation structures and examination with SEM. Collectively, these features suggest biomediated textures are preserved in early diagenetic <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxides</span>, and can persist for tens of millions of years. Modern microbially precipitated <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxides</span> and ~100ka tufa terraces from a cold spring system along Ten Mile Graben in southern Utah, USA are compared with the Morrison examples to identify modern microbial fossils and document any differences and preservation changes during diagenesis over geologic time. Two distinct suites of elements (1. C, Fe, As and 2. C, S, Se) are associated with microbial fossils in both the modern and ancient tufas, as well as the ancient Morrison specimens. The occurrence of these distinctive trace element configurations in the <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> minerals suggest the suites could be potential markers for biosignatures. The presence of ferrihydrite in ~100ka fossil microbial mats suggests this thermodynamically unstable mineral may also be used as a biomarker. Diagnostic trace element suites and unusual mineral phases warrant further study for their potential as biomarkers. These terrestrial <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxide</span> examples will: 1) document specific biomediated textures and what their origins might be (related to different processes or species), 2) show how they might persist or respond to diagenesis over time, and 3) provide a "ground truth" library of textures to explore and compare in extraterrestrial <span class="hlt">iron</span> (oxyhydr)<span class="hlt">oxides</span> where we hope to detect preserved evidence of life. Well-documented biomarkers in terrestrial deposits are valuable references and benchmarks for the search for extinct and preserved microbial exolife in <span class="hlt">iron</span> <span class="hlt">oxide</span> minerals of Mars.</p> <div class="credits"> <p class="dwt_author">Potter, S. L.; Chan, M. A.; McPherson, B. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">410</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22278120"> <span id="translatedtitle">Template assisted self-assembly of <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles: An x-ray structural analysis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">We have fabricated by e-beam lithography periodic arrays of rectangular shaped trenches of different widths into Si substrates. The trenches were filled with <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles, 20?nm in diameter, by spin-coating them onto the Si substrate. The trenches have the purpose to assist the self-assembly of the <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles. Using x-ray scattering techniques, we have analyzed the structure factor of the trenches before and after filling in order to determine the filling factor. We present a theoretical analysis of the x-ray scattering function within the distorted-wave Born approximation and we present a quantitative comparison between theory and experiment.</p> <div class="credits"> <p class="dwt_author">Mishra, D. [Department of Physics, Ruhr-University Bochum, 44780 Bochum (Germany); Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Strasse des 17. Juni 135, 10623 Berlin (Germany); Zabel, H. [Department of Physics, Ruhr-University Bochum, 44780 Bochum (Germany); Ulyanov, S. V. [St.-Petersburg State University, Ul'yanovskaya ul.1, Petrodvorets, St.-Petersburg 198904 (Russian Federation); St.-Petersburg University of Commerce and Economics, St.-Petersburg 194018 (Russian Federation); Romanov, V. P. [St.-Petersburg State University, Ul'yanovskaya ul.1, Petrodvorets, St.-Petersburg 198904 (Russian Federation); Uzdin, V. M. [St.-Petersburg State University, Ul'yanovskaya ul.1, Petrodvorets, St.-Petersburg 198904 (Russian Federation); St.-Petersburg National Research University of Information Technologies, Mechanics and Optics, 49, Kronverkskij, St.-Petersburg 197101 (Russian Federation)</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-02-07</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">411</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730011800&hterms=detecting+iron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddetecting%2Biron"> <span id="translatedtitle">Friction-induced surface activity of some hydrocarbons with clean and <span class="hlt">oxide</span>-covered <span class="hlt">iron</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Sliding friction studies were conducted on a clean and <span class="hlt">oxide</span>-covered <span class="hlt">iron</span> surface with exposure of that surface to various hydrocarbons. The hydrocarbons included ethane, ethylene ethyl chloride, methyl chloride, and vinyl chloride. Auger cylindrical mirror analysis was used to follow interactions of the hydrocarbon with the <span class="hlt">iron</span> surface. Results with vinyl chloride indicate friction induced surface reactivity, adsorption to surface <span class="hlt">oxides</span>, friction sensitivity to concentration and polymerization. Variation in the loads employed influence adsorption and accordingly friction. In contrast with ethyl and vinyl chloride, friction induced surface reactivity was not observed with ethane and ethylene.</p> <div class="credits"> <p class="dwt_author">Buckley, D. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">412</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5287837"> <span id="translatedtitle"><span class="hlt">Hydrate</span> detection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Project objectives were: (1) to create methods of analyzing gas <span class="hlt">hydrates</span> in natural sea-floor sediments, using available data, (2) to make estimates of the amount of gas <span class="hlt">hydrates</span> in marine sediments, (3) to map the distribution of <span class="hlt">hydrates</span>, (4) to relate concentrations of gas <span class="hlt">hydrates</span> to natural processes and infer the factors that control <span class="hlt">hydrate</span> concentration or that result in loss of <span class="hlt">hydrate</span> from the sea floor. (VC)</p> <div class="credits"> <p class="dwt_author">Dillon, W.P.; Ahlbrandt, T.S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">413</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10147402"> <span id="translatedtitle"><span class="hlt">Hydrate</span> detection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Project objectives were: (1) to create methods of analyzing gas <span class="hlt">hydrates</span> in natural sea-floor sediments, using available data, (2) to make estimates of the amount of gas <span class="hlt">hydrates</span> in marine sediments, (3) to map the distribution of <span class="hlt">hydrates</span>, (4) to relate concentrations of gas <span class="hlt">hydrates</span> to natural processes and infer the factors that control <span class="hlt">hydrate</span> concentration or that result in loss of <span class="hlt">hydrate</span> from the sea floor. (VC)</p> <div class="credits"> <p class="dwt_author">Dillon, W.P.; Ahlbrandt, T.S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">414</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2792909"> <span id="translatedtitle">A Silica-Supported <span class="hlt">Iron</span> <span class="hlt">Oxide</span> Catalyst Capable of Activating Hydrogen Peroxide at Neutral pH Values</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Iron</span> <span class="hlt">oxides</span> catalyze the conversion of hydrogen peroxide (H2O2) into <span class="hlt">oxidants</span> capable of transforming recalcitrant contaminants. Unfortunately, the process is relatively inefficient at circumneutral pH values due to competing reactions that decompose H2O2 without producing <span class="hlt">oxidants</span>. Silica- and alumina-containing <span class="hlt">iron</span> <span class="hlt">oxides</span> prepared by sol-gel processing of aqueous solutions containing Fe(ClO4)3, AlCl3 and tetraethyl orthosilicate efficiently catalyzed the decomposition of H2O2 into <span class="hlt">oxidants</span> capable of transforming phenol at circumneutral pH values. Relative to hematite, goethite and amorphous FeOOH, the silica-<span class="hlt">iron</span> <span class="hlt">oxide</span> catalyst exhibited a stoichiometric efficiency, defined as the number of moles of phenol transformed per mole of H2O2 consumed, that was 10 to 40 times higher than that of the <span class="hlt">iron</span> <span class="hlt">oxides</span>. The silica-alumina-<span class="hlt">iron</span> <span class="hlt">oxide</span> catalyst had a stoichiometric efficiency that was 50 to 80 times higher than that of the <span class="hlt">iron</span> <span class="hlt">oxides</span>. The significant enhancement in <span class="hlt">oxidant</span> production is attributable to the interaction of Fe with Al and Si in the mixed <span class="hlt">oxides</span>, which alters the surface redox processes, favoring the production of strong <span class="hlt">oxidants</span> during H2O2 decomposition. PMID:19943668</p> <div class="credits"> <p class="dwt_author">Pham, Anh Le-Tuan; Lee, Changha; Doyle, Fiona M.; Sedlak, David L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">415</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23865752"> <span id="translatedtitle">Catechol-functionalized chitosan/<span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle composite inspired by mussel thread coating and squid beak interfacial chemistry.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Biological materials offer a wide range of multifunctional and structural properties that are currently not achieved in synthetic materials. Herein we report on the synthesis and preparation of bioinspired organic/inorganic composites that mimic the key physicochemical features associated with the mechanical strengthening of both squid beaks and mussel thread coatings using chitosan as an initial template. While chitosan is a well-known biocompatible material, it suffers from key drawbacks that have limited its usage in a wider range of structural biomedical applications. First, its load-bearing capability in <span class="hlt">hydrated</span> conditions remains poor, and second it completely dissolves at pH < 6, preventing its use in mild acidic microenvironments. In order to overcome these intrinsic limitations, a chitosan-based organic/inorganic biocomposite is prepared that mimics the interfacial chemistry of squid beaks and mussel thread coating. Chitosan was functionalized with catechol moieties in a highly controlled fashion and combined with superparamagnetic <span class="hlt">iron</span> <span class="hlt">oxide</span> (?-Fe2O3) nanoparticles to give composites that represent a significant improvement in functionality of chitosan-based biomaterials. The inorganic/organic (?-Fe2O3/catechol) interfaces are stabilized and strengthened by coordination bonding, resulting in hybrid composites with improved stability at high temperatures, physiological pH conditions, and acid/base conditions. The inclusion of superparamagnetic particles also makes the composites stimuli-responsive. PMID:23865752</p> <div class="credits"> <p class="dwt_author">Zvarec, Ondrej; Purushotham, Sreekanth; Masic, Admir; Ramanujan, Raju V; Miserez, Ali</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-08-27</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">416</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/1027145"> <span id="translatedtitle">Trace element cycling through <span class="hlt">iron</span> <span class="hlt">oxide</span> minerals during redox-driven dynamic recrystallization</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Microbially driven <span class="hlt">iron</span> redox cycling in soil and sedimentary systems, including during diagenesis and fluid migration, may activate secondary abiotic reactions between aqueous Fe(II) and solid Fe(III) <span class="hlt">oxides</span>. These reactions catalyze dynamic recrystallization of <span class="hlt">iron</span> <span class="hlt">oxide</span> minerals through localized and simultaneous <span class="hlt">oxidative</span> adsorption of Fe(II) and reductive dissolution of Fe(III). Redox-active trace elements undergo speciation changes during this process, but the impact redox-driven recrystallization has on redox-inactive trace elements associated with <span class="hlt">iron</span> <span class="hlt">oxides</span> is uncertain. Here we demonstrate that Ni is cycled through the minerals goethite and hematite during redox-driven recrystallization. X-ray absorption spectroscopy demonstrates that during this process adsorbed Ni becomes progressively incorporated into the minerals. Kinetic studies using batch reactors containing aqueous Fe(II) and Ni preincorporated into <span class="hlt">iron</span> <span class="hlt">oxides</span> display substantial release of Ni to solution. We conclude that <span class="hlt">iron</span> <span class="hlt">oxide</span> recrystallization activated by aqueous Fe(II) induces cycling of Ni through the mineral structure, with adsorbed Ni overgrown in regions of Fe(II) <span class="hlt">oxidative</span> adsorption and incorporated Ni released in regions of reductive dissolution of structural Fe(III). The redistribution of Ni among the mineral bulk, mineral surface, and aqueous solution appears to be thermodynamically controlled and catalyzed by Fe(II). Our work suggests that important proxies for ocean composition on the early Earth may be invalid, identifies new processes controlling micronutrient availability in soil, sedimentary, and aquatic ecosystems, and points toward a mechanism for trace element mobilization during diagenesis and enrichment in geologic fluids.</p> <div class="credits"> <p class="dwt_author">Frierdich, Andrew J.; Luo, Yun; Catalano, Jeffrey G. (WU)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-11-17</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">417</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008GeCoA..72.3371D"> <span id="translatedtitle">Sorption of ferric <span class="hlt">iron</span> from ferrioxamine B to synthetic and biogenic layer type manganese <span class="hlt">oxides</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Siderophores are biogenic chelating agents produced in terrestrial and marine environments that increase the bioavailability of ferric <span class="hlt">iron</span>. Recent work has suggested that both aqueous and solid-phase Mn(III) may affect siderophore-mediated <span class="hlt">iron</span> transport, but scant information appears to be available about the potential roles of layer type manganese <span class="hlt">oxides</span>, which are relatively abundant in soils and the oligotrophic marine water column. To probe the effects of layer type manganese <span class="hlt">oxides</span> on the stability of aqueous Fe-siderophore complexes, we studied the sorption of ferrioxamine B [Fe(III)HDFOB +, an Fe(III) chelate of the trihydroxamate siderophore desferrioxamine B (DFOB)] to two synthetic birnessites [layer type Mn(III,IV) <span class="hlt">oxides</span>] and a biogenic birnessite produced by Pseudomonas putida GB-1. We found that all of these predominantly Mn(IV) <span class="hlt">oxides</span> greatly reduced the aqueous concentration of Fe(III)HDFOB + at pH 8. Analysis of Fe K-edge EXAFS spectra indicated that a dominant fraction of Fe(III) associated with the Mn(IV) <span class="hlt">oxides</span> is not complexed by DFOB as in solution, but instead Fe(III) is specifically adsorbed to the mineral structure at multiple sites, thus indicating that the Mn(IV) <span class="hlt">oxides</span> displaced Fe(III) from the siderophore complex. These results indicate that layer type manganese <span class="hlt">oxides</span>, including biogenic minerals, may sequester <span class="hlt">iron</span> from soluble ferric complexes. We conclude that the sorption of <span class="hlt">iron</span>-siderophore complexes may play a significant role in the bioavailability and biogeochemical cycling of <span class="hlt">iron</span> in marine and terrestrial environments.</p> <div class="credits"> <p class="dwt_author">Duckworth, Owen W.; Bargar, John R.; Sposito, Garrison</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">418</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23811518"> <span id="translatedtitle">Functional gene analysis of freshwater <span class="hlt">iron</span>-rich flocs at circumneutral pH and isolation of a stalk-forming microaerophilic <span class="hlt">iron-oxidizing</span> bacterium.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Iron</span>-rich flocs often occur where anoxic water containing ferrous <span class="hlt">iron</span> encounters oxygenated environments. Culture-independent molecular analyses have revealed the presence of 16S rRNA gene sequences related to diverse bacteria, including autotrophic <span class="hlt">iron</span> <span class="hlt">oxidizers</span> and methanotrophs in <span class="hlt">iron</span>-rich flocs; however, the metabolic functions of the microbial communities remain poorly characterized, particularly regarding carbon cycling. In the present study, we cultivated <span class="hlt">iron-oxidizing</span> bacteria (FeOB) and performed clone library analyses of functional genes related to carbon fixation and methane <span class="hlt">oxidization</span> (cbbM and pmoA, respectively), in addition to bacterial and archaeal 16S rRNA genes, in freshwater <span class="hlt">iron</span>-rich flocs at groundwater discharge points. The analyses of 16S rRNA, cbbM, and pmoA genes strongly suggested the coexistence of autotrophic <span class="hlt">iron</span> <span class="hlt">oxidizers</span> and methanotrophs in the flocs. Furthermore, a novel stalk-forming microaerophilic FeOB, strain OYT1, was isolated and characterized phylogenetically and physiologically. The 16S rRNA and cbbM gene sequences of OYT1 are related to those of other microaerophilic FeOB in the family Gallionellaceae, of the Betaproteobacteria, isolated from freshwater environments at circumneutral pH. The physiological characteristics of OYT1 will help elucidate the ecophysiology of microaerophilic FeOB. Overall, this study demonstrates functional roles of microorganisms in <span class="hlt">iron</span> flocs, suggesting several possible linkages between Fe and C cycling. PMID:23811518</p> <div class="credits"> <p class="dwt_author">Kato, Shingo; Chan, Clara; Itoh, Takashi; Ohkuma, Moriya</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">419</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010PhDT.........9Q"> <span id="translatedtitle">Synthesis, purification and assembly of gold and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The aims of the current research include developing new synthetic strategies to prepare structurally complex gold nanoparticles and new size sorting methods to separate nanoparticles of larger size, as well as studying the assembly of nanoparticles into novel hierarchical structures through both template-assisted and template-free strategies. In the synthesis section of this dissertation (Chapters 2 & 3), a size controllable synthesis of dendritic gold nanoparticles through a seed-mediated process in ethanol is described. The effect of seeds size and shape as well as the carbon chain length of alkylamines on the formation of dendritic structure was investigated. The synthetic strategy developed is capable of forming dendritic structure on various substrates, like flat or rod-like gold particles. In another work, the shape evolution of gold nanoparticles in a seed-mediated growth as well as the kinetics of reduction of HAuCl4 in the presence of seeds was studied. The reduction of the gold precursor by sodium citrate could be greatly accelerated in the presence of seed nanoparticles. Along with the enhanced reaction kinetics, dramatic shape evolution of gold nanoparticles was observed by changing ratios of precursors. In the purification section (Chapter 4), a novel method of separating nanoparticles of different sizes in a viscosity gradient was developed. The viscosity gradient was created with polyvinylpyrrolidone (PVP) aqueous solutions. Previously, such size separation was all achieved in the density gradient, while the hidden contribution of viscosity difference inside the density gradient was not well recognized. Through this work, it is clarified that the viscosity can contribute as importantly as density in the size sorting of nanoparticles through rate zonal centrifuge. It was also demonstrated both experimentally and mathematically that the viscosity gradient is more effective in separation of larger sized nanoparticles. In the assembly section (Chapter 5, 6 & 7), nanoparticles were assembled into three different hierachical structures through both template-assisted and template-free approaches. In the template-assisted assembly, gold nanorods were aligned into ordered 1D linear pattern by using soft biological filamentous, namely bacteria flagella, as templates. Two different ways of assembling nanorods onto flagella were investigated. In another study, a highly commercialized polymer, polyvinylpyrrolidone (PVP), was discovered for the first time to be able to self-assemble into branched hollow fibers. Based on this discovery, two approaches (one through direct deposition of silica onto the PVP aggregate and the other through co-assembly of PVP covered gold nanoparticles with free PVP molecules) by which the self-assembly behavior of PVP could be exploited to template the formation of branched hollow inorganic fibers were demonstrated. In the template-free assembly, a general method for assembling nanoparticle into clusters (NPCs) in an oil-in-water emulsion system was investigated. Detailed studies on the mechanism of formation of NPCs structure, optimized conditions, scalable production and surface chemistry manipulation were carried out. Besides, comparison of the properties of individual and clustered <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles was conducted. It was discovered that due to their collective properties, NPCs are more responsive to an external magnetic field and can potentially serve as better contrast enhancement agents than individually dispersed magnetic NPs in Magnetic Resonance Imaging (MRI).</p> <div class="credits"> <p class="dwt_author">Qiu, Penghe</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">420</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.nmr.mgh.harvard.edu/~cfarrar/NMR%20Biomed%20(2007).pdf"> <span id="translatedtitle">Impact of field strength and <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticle concentration on the linearity and diagnostic accuracy of off-resonance imaging</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Off-resonance imaging (ORI) techniques are being increasingly used to image <span class="hlt">iron</span> <span class="hlt">oxide</span> imaging agents such as monocrystalline <span class="hlt">iron</span> <span class="hlt">oxide</span> nanoparticles (MION). However, the diagnostic accuracy, linearity, and field dependence of ORI have not been fully characterized. In this study, the sensitivity, specificity, and linearity of ORI were thus examined as a function of both MION concentration and magnetic field strength</p> <div class="credits"> <p class="dwt_author">Christian T. Farrar; Guangping Dai; Mikhail Novikov; Anthony Rosenzweig; Ralph Weissleder; Bruce R. Rosen; David E. Sosnovik</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_20");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19")