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Sample records for low-spin ferric corrole

  1. Viking Helmet Corroles: Activating Inert Oxidometal Corroles.

    Science.gov (United States)

    Schweyen, Peter; Brandhorst, Kai; Hoffmann, Martin; Wolfram, Benedikt; Zaretzke, Marc-Kevin; Bröring, Martin

    2017-10-09

    Chemically inert oxidometal(V) corrols of molybdenum and rhenium undergo clean ligand-exchange reactions upon the action of SiCl 4 . The resulting dichlorido complexes show trigonal prismatic coordination of the metal ion with the chlorine atoms residing in a cis configuration, and were studied by optical and resonance spectroscopy as well as DFT calculations. In situ reactivity studies with carbon nucleophiles indicate high reactivity for chlorine replacement. Treatment with sodium cyclopentadienide paves the way to robust molybdenum corrolocene half-sandwich complexes. These organometallic compounds are the first corrole species that stabilize an air-stable and diamagnetic low spin d 2 -Mo IV center. Structural, spectroelectrochemical, and chemical investigations prove a reversible Mo IV /Mo V redox couple close to the Fc/Fc + potential for these systems. The high stability of the compounds in both redox states calls for future applications in catalysis and as redox switch. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Triphenylamine corrole dyads: Synthesis, characterization and ...

    Indian Academy of Sciences (India)

    acceptor (D-A) systems in which triphenylamine is the donor and substituted corroles i.e., 5,15-phenyl-10- ..... trate that electronic communication between corrole and TPA chromophores is .... nical exchange).57 Both the Forster and the Dexter mechanisms .... energy-optimized structures, HOMO-LUMO pictures and the ...

  3. The Synthesis and Characterization of Several Corroles

    African Journals Online (AJOL)

    NICO

    dichloromethane, no corrole was detected in the resulting ... NMR spectrum with only three distinct signals for the protons in ..... solid state and in solution was brought to light by the discovery ..... weak electron density near the molecules.

  4. Corroles-Porphyrins: A Teamwork for Gas Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Rosamaria Capuano

    2015-04-01

    Full Text Available Porphyrins provide an excellent material for chemical sensors, and they have been used for sensing species both in air and solution. In the gas phase, the broad selectivity of porphyrins is largely dependant on molecular features, such as the metal ion complexed at the core of the aromatic ring and the peripheral substituents. Although these features have been largely exploited to design gas sensor arrays, so far, little attention has been devoted to modify the sensing properties of these macrocycles by variation of the molecular aromatic ring. In this paper, the gas sensing properties of a porphyrin analog, the corrole, are studied in comparison with those of the parent porphyrin. Results show that changes in the aromatic ring have important consequences on the sensitivity and selectivity of the sensors and that porphyrins and corroles can positively cooperate to enhance the performance of sensor arrays.

  5. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  6. Light induced intramolecular electron and energy transfer events in rigidly linked borondipyrromethene: Corrole Dyad

    Energy Technology Data Exchange (ETDEWEB)

    Giribabu, Lingamallu, E-mail: giribabu@iict.res.in [Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Telangana (India); Jain, Kanika [Department of Chemistry, School of Chemical Sciences & Pharmacy, Central University of Rajasthan, Kishangarh, Dist. Ajmer, Rajasthan 305817 (India); Sudhakar, Kolanu; Duvva, Naresh [Inorganic & Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Telangana (India); Chitta, Raghu, E-mail: raghuchitta@curaj.ac.in [Department of Chemistry, School of Chemical Sciences & Pharmacy, Central University of Rajasthan, Kishangarh, Dist. Ajmer, Rajasthan 305817 (India)

    2016-09-15

    We have designed and synthesized a photo-induced energy/electron donor–acceptor conjugate comprising of corrole linked to BODIPY at the 5-position via ester linkage. The dyad was characterized by elemental analysis, MALDI-MS, UV-Visible, {sup 1}H NMR fluorescence spectroscopy (steady-state and time-resolved) as well as electrochemical methods. A comparison of the UV–visible and {sup 1}H NMR spectra of the dyad with those of the corresponding individual model compounds (i.e., BODIPY-CO{sub 2}H and BPFC-OH) reveal that there exist minimum π–π interactions between BODIPY and corrole π-planes. Quenched emission of BODIPY and corrole part of the dyad has been observed in five different solvents. Excitation spectral data provided evidence for an intramolecular excitation energy transfer (EET) from the singlet BODIPY to the corrole and an intramolecular photoinduced electron transfer (PET) from singlet state of corrole to ground state of BODIPY. Detailed analysis of the data suggests that Forster's dipole–dipole mechanism does not adequately explain this energy transfer but, an electron exchange mediated mechanism can, in principle, contribute to the intramolecular EET.

  7. Manipulation resolves non-trivial structure of corrole monolayer on Ag(111)

    International Nuclear Information System (INIS)

    Tebi, Stefano; Serrano, Giulia; Koch, Reinhold; Müllegger, Stefan; Aldahhak, Hazem; Rauls, Eva; Schmidt, Wolf Gero; Schöfberger, Wolfgang

    2016-01-01

    Non-trivial arrangement of molecules within a molecular network complicates structure determination due to interdigitation, partial overlap, or stacking. We demonstrate that combined imaging and lateral manipulation with a scanning tunneling microscope resolves the intricate structure of a molecular network in two-dimensions in a straightforward manner. The network, formed by a monolayer of 5,10,15-tris(pentafluorophenyl)-corrole molecules on Ag(111), is manipulated for the first time with single-molecule precision. Our results reveal a shingle-like packing of partially overlapping corrole molecules. Density functional theory calculations support our findings. (paper)

  8. A green method for the preparation of fluorescent hybrid structures of gold and corrole

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Ângela S., E-mail: aspereira@ua.pt; Barata, Joana F. B. [University of Aveiro, CICECO – Chemistry Department, Aveiro Institute of Materials (Portugal); Vaz Serra, Vanda I. R. C. [University of Aveiro, QOPNA Chemistry Department (Portugal); Pereira, Sérgio; Trindade, Tito [University of Aveiro, CICECO – Chemistry Department, Aveiro Institute of Materials (Portugal)

    2015-10-15

    Gold/soap nanostructures were prepared by a green methodology using saponified household sunflower oil, as reducing and organic dispersing agent of auric acid. The incorporation of hydrophobic molecules on the novel water-soluble gold nanoparticles was followed by fluorescence lifetime imaging microscopy, using as model hydrophobic compound 5,10,15-tris-(pentafluorophenyl)corrolatogallium(III)(pyridine) (GaPFC), a highly fluorescent corrole. The results showed the hydrophobic GaPFC located between the organic bilayer surrounding several Au nanoparticles, which in turn were coated with fatty acids salts anchored by the double bond at the gold’s surface.

  9. Low-spin identical bands in odd-A nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Baktash, C; Garrett, J D; Winchell, D F; Smith, A [Oak Ridge National Lab., TN (United States)

    1992-08-01

    A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig.

  10. Low-spin identical bands in rare earth nuclei

    International Nuclear Information System (INIS)

    Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

    1992-01-01

    A comprehensive study of odd-A rotational bands in normally deformed rare earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

  11. Low-spin identical bands in odd-A nuclei

    International Nuclear Information System (INIS)

    Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

    1992-01-01

    A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

  12. Low-spin identical bands in odd-A nuclei

    International Nuclear Information System (INIS)

    Baktash, C.; Garrett, J.D.; Winchell, D.F.; Smith, A.

    1992-01-01

    A comprehensive study of odd-A rotational bands in normally-deformed rare-earth nuclei indicates that a large number of seniority-one configurations (30% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models, based on the traditional picture of nuclear pair correlation in vogue for more than three decades, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (author). 18 refs., 1 tab., 1 fig

  13. Synthesis and photophysical properties of a novel corrole–anthraquinone–corrole molecular system

    International Nuclear Information System (INIS)

    Sudhakar, Kolanu; Kanaparthi, Ravi Kumar; Kumar, Challa Kiran; Giribabu, Lingamallu

    2014-01-01

    A novel molecular triad (AQ-(H 3 ) 2 ) based on tritolylcorrole and anthraquinone having azomethine-bridge at the pyrrole-β position has been designed and synthesized by following a facile one step reaction. The molecular system, AQ-(H 3 ) 2 is characterized by elemental analysis, MALDI-MS, 1 H-NMR, UV–Visible and fluorescence spectroscopy (steady-state and time-resolved) as well as electrochemical methods. In absorption spectra, prominent changes such as red-shift (∼7 nm) and broadening of the both Soret and Q-bands with respect to their monomer units were observed. The present study supported by density functional theory calculations manifest that there exists a negligible electronic communication in the ground state between the donor tritolylcorrole and acceptor anthraquinone of the triad. However, interestingly, in the triad AQ-(H 3 ) 2 , fluorescence emission of the tritolylcorrole quenched significantly (17–80%) compared to their monomeric units. The emission quenching is attributed to the excited state intramolecular photoinduced electron transfer from donor tritolylcorrole to acceptor anthraquinone and the electron transfer rates (k ET ) are found in the range 4.1×10 8 to 2.4×10 9 s −1 and are found to be solvent dependent. - Highlights: • Molecular triad based on corrole and anthraquinone having azomethine-bridge at pyrrole-β position. • Ground state properties showed that there exist minimum π–π interactions. • Excited state properties showed intramolecular photoinduced electron transfer from corrole to anthraquinone

  14. Synthesis and photophysical properties of a novel corrole–anthraquinone–corrole molecular system

    Energy Technology Data Exchange (ETDEWEB)

    Sudhakar, Kolanu [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad-500007, Andhra Pradesh (India); Kanaparthi, Ravi Kumar [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad-500007, Andhra Pradesh (India); Department of Chemistry, Central University of Kerala, Reverside Transit Campus, Padanakkad, Nileshwar Kasaragod District - 671 314 Kerala (India); Kumar, Challa Kiran [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad-500007, Andhra Pradesh (India); Giribabu, Lingamallu, E-mail: giribabu@iict.res.in [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad-500007, Andhra Pradesh (India)

    2014-09-15

    A novel molecular triad (AQ-(H{sub 3}){sub 2}) based on tritolylcorrole and anthraquinone having azomethine-bridge at the pyrrole-β position has been designed and synthesized by following a facile one step reaction. The molecular system, AQ-(H{sub 3}){sub 2} is characterized by elemental analysis, MALDI-MS, {sup 1}H-NMR, UV–Visible and fluorescence spectroscopy (steady-state and time-resolved) as well as electrochemical methods. In absorption spectra, prominent changes such as red-shift (∼7 nm) and broadening of the both Soret and Q-bands with respect to their monomer units were observed. The present study supported by density functional theory calculations manifest that there exists a negligible electronic communication in the ground state between the donor tritolylcorrole and acceptor anthraquinone of the triad. However, interestingly, in the triad AQ-(H{sub 3}){sub 2}, fluorescence emission of the tritolylcorrole quenched significantly (17–80%) compared to their monomeric units. The emission quenching is attributed to the excited state intramolecular photoinduced electron transfer from donor tritolylcorrole to acceptor anthraquinone and the electron transfer rates (k{sub ET}) are found in the range 4.1×10{sup 8} to 2.4×10{sup 9} s{sup −1} and are found to be solvent dependent. - Highlights: • Molecular triad based on corrole and anthraquinone having azomethine-bridge at pyrrole-β position. • Ground state properties showed that there exist minimum π–π interactions. • Excited state properties showed intramolecular photoinduced electron transfer from corrole to anthraquinone.

  15. A Low Spin Manganese(IV) Nitride Single Molecule Magnet.

    Science.gov (United States)

    Ding, Mei; Cutsail, George E; Aravena, Daniel; Amoza, Martín; Rouzières, Mathieu; Dechambenoit, Pierre; Losovyj, Yaroslav; Pink, Maren; Ruiz, Eliseo; Clérac, Rodolphe; Smith, Jeremy M

    2016-09-01

    Structural, spectroscopic and magnetic methods have been used to characterize the tris(carbene)borate compound PhB(MesIm) 3 Mn≡N as a four-coordinate manganese(IV) complex with a low spin ( S = 1/2) configuration. The slow relaxation of the magnetization in this complex, i.e. its single-molecule magnet (SMM) properties, is revealed under an applied dc field. Multireference quantum mechanical calculations indicate that this SMM behavior originates from an anisotropic ground doublet stabilized by spin-orbit coupling. Consistent theoretical and experiment data show that the resulting magnetization dynamics in this system is dominated by ground state quantum tunneling, while its temperature dependence is influenced by Raman relaxation.

  16. 21 CFR 184.1297 - Ferric chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric chloride. 184.1297 Section 184.1297 Food and... Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride, FeC13, CAS Reg. No. 7705-08-0) may be prepared from iron and chlorine or from ferric oxide and hydrogen chloride...

  17. Phosphorus(V)-corrole: synthesis, spectroscopic properties, theoretical calculations, and potential utility for in vivo applications in living cells.

    Science.gov (United States)

    Liang, Xu; Mack, John; Zheng, Li-Min; Shen, Zhen; Kobayashi, Nagao

    2014-03-17

    The synthesis and properties of phosphorus(V) 5,10,15-tris(4-methoxycarbonylphenyl)corrole (1) have been investigated, and its potential utility for bioimaging applications in living cells has been explored. As would normally be anticipated for corrole complexes, the intensity of the Q(0,0) bands of 1 is greater than those of comparable phosphorus(V) tetraphenylporphyrins, but the ΦF values (0.25 for 1) are found to be comparable. A detailed analysis of the electronic structure of the complex was carried out by comparing electronic absorption and MCD spectral data to the results of TD-DFT calculations. The meso-aryl substituents, which enhance the lipophilicity of 1 and hence result in its localization in intracellular membranes during HeLa cell experiments, are predicted to result in a narrowing of the HOMO-LUMO gap and hence a red shift of the Q(0,0) bands toward the optical window in biological tissues.

  18. Development of Acoustic Devices Functionalized with Cobalt Corroles or Metalloporphyrines for the Detection of Carbon Monoxide at Low Concentration

    Directory of Open Access Journals (Sweden)

    Meddy VANOTTI

    2012-03-01

    Full Text Available Progresses in synthetic chemistry methodologies has pushed to develop a large variety of artificial receptors of particular interest for chemical sensor applications. We investigate here the behavior of gas sensors based on surface acoustic wave (SAW devices. The use of Love waves that are specially sensitive to surface perturbation enables to exploit the molecular recognition processes occurring in non conductive sensing layers of cobalt corroles [5,10,15-Tris(2,6-dichlorophenylcorrolato]cobalt(III] for CO detection. We have monitored phase variations of Love-wave-based delay lines under various operation conditions and studied the detection efficiency of a differential version of our sensors. A test bench also has especially been developed to allow for the regeneration of the sensor by freeing the CO trapping sites and therefore to provide an accurate control of the operation conditions. The detection threshold reached using the proposed SAW sensor is experimentally found below one ppm.

  19. Polymeric optical sensors for selective and sensitive nitrite detection using cobalt(III) corrole and rhodium(III) porphyrin as ionophores

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Si; Wo, Yaqi; Meyerhoff, Mark E., E-mail: mmeyerho@umich.edu

    2014-09-16

    Highlights: • We examine cobalt(III) corroles and rhodium(III) porphyrins as ionophores in polymeric films for optical sensors to detect nitrite. • Different types of proton chromoionophores are evaluated to optimize nitrite response. • Selectivity over lipophilic anions such as perchlorate and thiocyanate is observed. • Both ionophores yield optical sensors that are fully reversible. • The cobalt(III) corrole based sensor is employed to determine nitric oxide emission rates from NO donor doped polymers with good accuracy. - Abstract: Cobalt(III) 5,10,15-tris(4-tert-butylphenyl) corrole with a triphenylphosphine axial ligand and rhodium(III) 5,10,15,20-tetra(p-tert-butylphenyl) porphyrin are incorporated into plasticized poly(vinyl chloride) films to fabricate nitrite-selective bulk optodes via absorbance measurements. The resulting films yield sensitive, fast and fully reversible response toward nitrite with significantly enhanced nitrite selectivity over other anions including lipophilic anions such as thiocyanate and perchlorate. The selectivity patterns differ greatly from the Hofmeister series based on anion lipophilicity and are consistent with selectivity obtained with potentiometric sensors based on the same ionophores. The optical nitrite sensors are shown to be useful for detecting rates of emission of nitric oxide (NO) from NO releasing polymers containing S-nitroso-N-acetyl-DL-penicillamine.

  20. Photodynamic effects induced by meso-tris(pentafluorophenyl)corrole and its cyclodextrin conjugates on cytoskeletal components of HeLa cells.

    Science.gov (United States)

    Barata, Joana F B; Zamarrón, Alicia; Neves, M Graça P M S; Faustino, M Amparo F; Tomé, Augusto C; Cavaleiro, José A S; Röder, Beate; Juarranz, Ángeles; Sanz-Rodríguez, Francisco

    2015-03-06

    The aim of this work was to synthesize new corrole β-cyclodextrin conjugates βCD1 (with one β-cyclodextrin moiety) and βCD2 (with two β-cyclodextrin moieties) from 5,10,15-tris(pentafluorophenyl)corrole (TPFC) and to test in vitro the efficacy of these compounds towards tumoral HeLa cells. No dark cytotoxicity was observed for TPFC and βCD1 at the concentration used for PDT cell treatment, even during long incubation periods (24 h). Fluorescence microscopy showed that TPFC and βCD1 accumulate in HeLa cells at lysosomes and in the Golgi apparatus, respectively. The cell survival after the PDT treatment with visible light was dependent on light exposure level and compound concentration. βCD1 was able to penetrate efficiently in the cytoplasm of the HeLa cells. In particular, we have analyzed the photodynamic effect of the corrole derivatives on the microtubules of HeLa cells and the morphological alterations on the mitotic spindle. TPFC and βCD1 caused photocytotoxicity in tumoral HeLa cells and induced a rapid metaphase blockage of cells that also showed clearly altered configurations of the mitotic spindle. The results showed that TPFC has the highest photosensitizing efficiency on tumoral cells. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  1. Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

    Directory of Open Access Journals (Sweden)

    Clark Zahn

    2017-07-01

    Full Text Available Corroles are a developing class of tetrapyrrole-based molecules with significant chemical potential and relatively unexplored photophysical properties. We combined femtosecond broadband fluorescence up-conversion and fs broadband Vis-pump Vis-probe spectroscopy to comprehensively characterize the photoreaction of 5,10,15-tris-pentafluorophenyl-corrolato-antimony(V-trans-difluoride (Sb-tpfc-F2. Upon fs Soret band excitation at ~400 nm, the energy relaxed almost completely to Q band electronic excited states with a time constant of 500 ± 100 fs; this is evident from the decay of Soret band fluorescence at around 430 nm and the rise time of Q band fluorescence, as well as from Q band stimulated emission signals at 600 and 650 nm with the same time constant. Relaxation processes on a time scale of 10 and 20 ps were observed in the fluorescence and absorption signals. Triplet formation showed a time constant of 400 ps, with an intersystem crossing yield from the Q band to the triplet manifold of between 95% and 99%. This efficient triplet formation is due to the spin-orbit coupling of the antimony ion.

  2. Development of a radiochromic ferric oligomer hydrogel

    International Nuclear Information System (INIS)

    Jordan, Kevin; Sekimoto, Masaya

    2010-01-01

    Ferrous gelatin hydrogels were prepared by using sulphuric acid concentrations lower than required to maintain radiation induced ferric ions fully hydrated. The ferric hydroxyl species that are produced following irradiation exhibit a radiochromic response that can be probed with blue light. The dose distribution shapes were stable in time, indicating no long term diffusion. An over response to dose gradients was observed both in one centimeter cuvette samples and litre volumes probed with optical cone beam CT. This ferrous hydrogel may represent a model system for studying iron radiochemistry in biological systems.

  3. Intravenous ferric carboxymaltose for anaemia in pregnancy.

    Science.gov (United States)

    Froessler, Bernd; Collingwood, Joshua; Hodyl, Nicolette A; Dekker, Gustaaf

    2014-03-25

    Iron deficiency is a common nutritional deficiency amongst women of childbearing age. Peri-partum iron deficiency anaemia (IDA) is associated with significant maternal, fetal and infant morbidity. Current options for treatment are limited: these include oral iron supplementation, which can be ineffective and poorly tolerated, and red blood cell transfusions, which carry an inherent risk and should be avoided. Ferric carboxymaltose is a new treatment option that may be better tolerated.The study was designed to assess the safety and efficacy of iron deficiency anaemia (IDA) correction with intravenous ferric carboxymaltose in pregnant women with mild, moderate and severe anaemia in the second and third trimester. Prospective observational study; 65 anaemic pregnant women received ferric carboxymaltose up to 15 mg/kg between 24 and 40 weeks of pregnancy (median 35 weeks gestational age, SD 3.6). Treatment effectiveness was assessed by repeat haemoglobin (Hb) measurements and patient report of well-being in the postpartum period. Safety was assessed by analysis of adverse drug reactions and fetal heart rate monitoring during the infusion. Intravenous ferric carboxymaltose infusion significantly increased Hb values (p anaemia in pregnancy.

  4. FERRIC CITRATE: AN IRON-BASED ORAL PHOSPHATE BINDER

    Directory of Open Access Journals (Sweden)

    T. Christopher Bond

    2012-06-01

    Based on actual physician behavior in response to ferritin and TSAT increases and ferric citrate clinical trial results, and assuming equivalent pricing to other PBs, there would be cost savings with ferric citrate use through reduced ESA and iron use.

  5. Low-spin identical bands in neighboring odd-A and even-even nuclei

    International Nuclear Information System (INIS)

    Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

    1992-01-01

    A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority

  6. Low-spin identical bands in neighboring odd-A and even-even nuclei

    International Nuclear Information System (INIS)

    Baktash, C.; Winchell, D.F.; Garrett, J.D.; Smith, A.

    1993-01-01

    A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21 % for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority. (orig.)

  7. USING MAGNETIC MOMENTS TO UNVEIL THE NUCLEAR STRUCTURE OF LOW-SPIN NUCLEAR STATES

    Directory of Open Access Journals (Sweden)

    Diego A. Torres

    2011-07-01

    Full Text Available The experimental study of magnetic moments for nuclear states near the ground state, I ≤ 2, provides a powerful tool to test nuclear structure models. Traditionally, the use of Coulomb excitation reactions has been used to study low spin states, mostly I = 2. The use of alternative reaction channels, such as α transfer, for the production of radioactive species that, otherwise, will be only produced in future radioactive beam facilities has proved to be an alternative to measure not only excited states with I > 2, but to populate and study long-live radioactive nuclei. This contribution will present the experimental tools and challenges for the use of the transient field technique for the measurement of g factors in nuclear states with I ≤ 2, using Coulomb excitation and α-transfer reactions. Recent examples of experimental results near the N = 50 shell closure, and the experimental challenges for future implementations with radioactive beams, will be discussed.

  8. Decay of Hot Nuclei at Low Spins Produced by Antiproton-Annihilation in Heavy Nuclei

    CERN Multimedia

    2002-01-01

    % PS208 \\\\ \\\\ The objective of the experiment is to study (i) the thermal excitation energy distribution of antiproton-induced reactions in heavy nuclei and (ii) the decay properties of hot nuclei at low spins via evaporation, multifragmentation and fission as a function of excitation energy. The experimental set-up consists of 4-$\\pi$ detectors: the Berlin Neutron Ball~(BNB) which is a spherical shell of gadolinium-loaded scintillator liquid with an inner and outer diameter of 40 and 160~cm, respectively. This detector counts the number of evaporated neutrons in each reaction. Inside BNB there is a 4-$\\pi$ silicon ball~(BSIB) with a diameter of 20~cm consisting of 162 detectors which measure energy and multiplicity of all emitted charged nuclear particles. The particles are identified via time of flight, energy and pulse shape correlations.

  9. Total gastrectomy due to ferric chloride intoxication.

    Science.gov (United States)

    Menéndez, A Mesut; Abramson, Leonardo; Vera, Raúl A; Duza, Guillermo E; Palermo, Mariano

    2015-09-01

    The ferric chloride intoxication is frequently caused by accident. Its toxicity is generally underrated, which can lead to fatal evolution or irreversible consequences. In this case, the caustic condition of the substance is related to the toxic properties of iron. A 36-year-old male patient arrives by ambulance indicating sensory deterioration. He presents erosive injuries in the buccal cavity and in the oropharynx, brownish teeth and metabolic acidosis. Toxicology tests and ferritin blood dosage are requested, which show a result from 1400 mg/dl. The symptoms are interpreted as acute iron intoxication. Due to the unfavorable evolution of his condition, an abdominal and pelvic CT scan are performed, which show extensive pneumoperitoneum and free fluid in the abdominal cavity. An exploratory laparotomy, a total gastrectomy with esophagostomy and feeding jejunostomy, washing and drainage due to perforated gastric necrosis caused by caustic ingestion are performed. In our country, there is a high rate of intoxication caused by iron compounds, although it is not statistically measured. Nevertheless, the ferric chloride intoxication is extremely infrequent. The ingestion of this product leads to complications, which are associated with the iron concentration and its condition as a caustic agent. The surgical indications in the presence of intoxication caused by iron compounds are: stomach evacuation of iron, gastric necrosis, perforation or peritonitis and stenosis. Early or prophylactic gastrectomy is contraindicated. However, if complications that require immediate surgical intervention arise, there should be no hesitation and the corresponding procedure should be performed.

  10. Signatures of triaxiality in low-spin spectra of 86Ge

    Science.gov (United States)

    Lettmann, M.; Werner, V.; Pietralla, N.; Doornenbal, P.; Obertelli, A.; Rodríguez, T. R.; Sieja, K.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Chen, S.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Lapoux, V.; Motobayashi, T.; Niikura, M.; Paul, N.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Ando, T.; Arici, T.; Blazhev, A.; Browne, F.; Bruce, A.; Caroll, R. J.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Górska, M.; Gottardo, A.; Jungclaus, A.; Lee, J.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Momiyama, S.; Moschner, K.; Nagamine, S.; Nakatsuka, N.; Nita, C.; Nobs, C. R.; Olivier, L.; Patel, Z.; Podolyák, Zs.; Rudigier, M.; Saito, T.; Shand, C.; Söderström, P.-A.; Stefan, I.; Vaquero, V.; Wimmer, K.; Xu, Z.

    2018-05-01

    Low-spin states of neutron-rich 84,86,88Ge were measured by in-flight γ-ray spectroscopy at 270 MeV/u at the RIKEN-RIBF facility. The exotic beams have been produced by primary 238U in-flight fission reactions and impinged on the MINOS device. MINOS combines a 10-cm long LH2 target with a Time Projection Chamber (TPC) to reconstruct the reaction vertices. The reactions were selected by the BigRIPS and the ZeroDegree spectrometers for the incoming and outgoing channels, respectively. Emitted γ radiation was detected by the NaI-array DALI2. De-excitations from the {6}1+, {4}1,2+, and {2}1,2+ states of 84,86Ge and {4}1+ and {2}1,2+ states of 88Ge were observed. The data are compared to state-of-the-art shell model and beyond-mean-field calculations. Furthermore, a candidate for a {3}1+ state of 86Ge was identified. This state plays a key role in the discussion of ground-state triaxiality of 86Ge, along with other features of the low-energy level scheme. This work was published in [1].

  11. Core breaking and octupole low-spin states in $^{207}$ Tl

    CERN Multimedia

    We propose to study the low-spin level structure of the $^{207}$Tl nucleus populated by the $\\beta$- decay of $^{207}$Hg. While $^{207}$Tl is a single-proton hole nucleus, the majority of the observed states will have a three-particle structure thus requiring the breaking of the neutron or proton core, or a collective octupole phonon coupled to the single proton hole. Thus information will be obtained on the single particle orbitals in the vicinity of the N=126 and Z=82 magic numbers, and on the size of the shell gap. The results will be used to improve the predictive power of the shell model for more exotic nuclei as we move to lighter N=126 nuclei.The experiment will use the ISOLDE Decay station, and will take advantage of the $^{207}$Hg beam from the molten lead target. A test on the feasibility to produce an $^{208}$Hg beam from the same target, with the aim to study the $\\beta$-decay into $^{208}$Tl, could be performed at the same time.

  12. Extraction with tributyl phosphate (TBP) from ferric nitrate solutions

    International Nuclear Information System (INIS)

    Kolarik, Z.; Grudpan, K.

    1985-01-01

    Ferric nitrate acts as a strong salting-out agent in the extraction of thorium(IV), uranyl, europium(III), samarium(III) and zirconium(IV) nitrates as well as of nitric acid with tributyl phosphate in dodecane. Nitric acid, if present in the extraction system together with large amounts of ferric nitrate, markedly suppresses the extraction of thorium(IV) and lanthanides(III) but significantly supports the extraction of zirconium(IV). Separation factors of different metal pairs are presented as functions of the concentrations of ferric nitrate and nitric acid

  13. New low-spin states of 122Xe observed via high-statistics β-decay of 122Cs

    Science.gov (United States)

    Jigmeddorj, B.; Garrett, P. E.; Andreoiu, C.; Ball, G. C.; Bruhn, T.; Cross, D. S.; Garnsworthy, A. B.; Hadinia, B.; Moukaddam, M.; Park, J.; Pore, J. L.; Radich, A. J.; Rajabali, M. M.; Rand, E. T.; Rizwan, U.; Svensson, C. E.; Voss, P.; Wang, Z. M.; Wood, J. L.; Yates, S. W.

    2018-05-01

    Excited states of 122Xe were studied via the β+/EC decay of 122Cs with the 8π γ-ray spectrometer at the TRIUMF-ISAC facility. Compton-suppressed HPGe detectors were used for measurements of γ-ray intensities, γγ coincidences, and γ-γ angular correlations. Two sets of data were collected to optimize the decays of the ground (21.2 s) and isomeric (3.7 min) states of 122Cs. The data collected have enabled the observation of about 505 new transitions and about 250 new levels, including 51 new low-spin states. Spin assignments have been made for 58 low-spin states based on the deduced β-decay feeding and γ-γ angular correlation analyses.

  14. Hydrolysis of ferric chloride in solution

    International Nuclear Information System (INIS)

    Lussiez, G.; Beckstead, L.

    1996-11-01

    The Detox trademark process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200 degrees C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl 3 liquid + H 2 O → FeOCl solid + 2 HCl gas During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOCl solid + H 2 O → Fe 2 O 3 solid + 2 HCl gas . The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way

  15. Spin-state responses to light impurity substitution in low-spin perovskite LaCoO3

    Science.gov (United States)

    Tomiyasu, Keisuke; Kubota, Yuuki; Shimomura, Saya; Onodera, Mitsugi; Koyama, Syun-Ichi; Nojima, Tsutomu; Ishihara, Sumio; Nakao, Hironori; Murakami, Youichi

    2013-06-01

    We studied the spin-state responses to light impurity substitution in low-spin perovskite LaCoO3 (Co3+: d6) through magnetization, x-ray fluorescence, and electrical resistivity measurements of single-crystal LaCo0.99M0.01O3 (M = Cr, Mn, Fe, Ni). In the magnetization curves measured at 1.8 K, a change in the spin-state was not observed for Cr, Mn, or Fe substitution but was observed for Ni substitution. Strong magnetic anisotropy was also found in the Ni-substituted sample. The fluorescence measurements revealed that the valences were roughly estimated to be Cr3+, Mn(4-δ)+, Fe(3+δ')+, and Ni3+. From the observed chemical trends, we propose that the chemical potential is a key factor in inducing the change of the low-spin state. By expanding a model of the ferromagnetic spin-state heptamer generated by hole doping [Podlesnyak , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.101.247603 101, 247603 (2008)], the emergence of highly anisotropic spin-state molecular ferromagnets induced by low-spin Ni3+ with Jahn-Teller activity is suggested. We also discuss applicability of the present results to other materials with Fe (d6).

  16. The Nox/Ferric reductase/Ferric reductase-like families of Eumycetes.

    Science.gov (United States)

    Grissa, Ibtissem; Bidard, Frédérique; Grognet, Pierre; Grossetete, Sandrine; Silar, Philippe

    2010-09-01

    Reactive Oxygen Species (ROS) are involved in plant biomass degradation by fungi and development of fungal structures. While the ROS-generating NADPH oxidases from filamentous fungi are under strong scrutiny, much less is known about the related integral Membrane (or Ferric) Reductases (IMRs). Here, we present a survey of these enzymes in 29 fungal genomes covering the entire available range of fungal diversity. IMRs are present in all fungal genomes. They can be classified into at least 24 families, underscoring the high diversity of these enzymes. Some are differentially regulated during colony or fruiting body development, as well as by the nature of the carbon source of the growth medium. Importantly, functional characterization of IMRs has been made on proteins belonging to only two families, while nothing or very little is known about the proteins of the other 22 families. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  17. Quantum chemical analysis of the electronic structure and Moessbauer spectra parameters for low spin cyanide- and pyridine-hemichromes

    International Nuclear Information System (INIS)

    Khleskov, V.I.; Kolpakov, E.V.; Smirnov, A.B.

    1992-01-01

    The work contains results of quantum-chemical calculations of electronic structure and Moessbauer spectra parameters for low spin S=1/2 hexa-coordinated ferri-porphyrin complexes with cyanide (CN) and pyridine (Py) as axial ligands. Theoretical results made it possible to explain experimentally observed regularity of anomalous quadrupole splitting decrease after substitution of Py-ligands by CN. Comparison of theoretical and experimental data indicated that 2 E g must be the ground state of investigated hemichromes. In this state unpaired electron symmetrically occupies d π -orbitals of Fe-ion. (orig.)

  18. Ferric sulfates on Mars: Surface Explorations and Laboratory Experiments

    Science.gov (United States)

    Wang, A.; Ling, Z.; Freeman, J. J.

    2008-12-01

    Recent results from missions to Mars have reinforced the importance of sulfates for Mars science. They are the hosts of water, the sinks of acidity, and maybe the most active species in the past and current surface/near-surface processes on Mars. Fe-sulfate was found frequently by Spirit and Opportunity rovers: jarosite in Meridiani Planum outcrops and a less specific "ferric sulfate" in the salty soils excavated by Spirit at Gusev Crater. Pancam spectral analysis suggests a variety of ferric sulfates in these soils, i.e. ferricopiapite, jarosite, fibroferrite, and rhomboclase. A change in the Pancam spectral features occurred in Tyrone soils after ~ 190 sols of exposure to surface conditions. Dehydration of ferric sulfate is a possible cause. We synthesized eight ferric sulfates and conducted a series of hydration/dehydration experiments. Our goal was to establish the stability fields and phase transition pathways of these ferric sulfates. In our experiments, water activity, temperature, and starting structure are the variables. No redox state change was observed. Acidic, neutral, and basic salts were used. Ferric sulfate sample containers were placed into relative humidity buffer solutions that maintain static relative humidity levels at three temperatures. The five starting phases were ferricopiapite (Fe4.67(SO4)6(OH)2.20H2O), kornelite (Fe2(SO4)3.7H2O), rhomboclase (FeH(SO4)2.4H2O), pentahydrite (Fe2(SO4)3.5H2O), and an amorphous phase (Fe2(SO4)3.5H2O). A total of one hundred fifty experiments have been running for nearly ten months. Thousands of coupled Raman and gravimetric measurements were made at intermediate steps to monitor the phase transitions. The first order discovery from these experiments is the extremely large stability field of ferricopiapite. Ferricopiapite is the major ferric sulfate to precipitate from a Fe3+-S-rich aqueous solution at mid-low temperature, and it has the highest H2O/Fe ratio (~ 4.3). However, unlike the Mg-sulfate with highest

  19. Gas-phase spectroscopy of ferric heme-NO complexes

    DEFF Research Database (Denmark)

    Wyer, J.A.; Jørgensen, Anders; Pedersen, Bjarke

    2013-01-01

    and significantly blue-shifted compared to ferric heme nitrosyl proteins (maxima between 408 and 422 nm). This is in stark contrast to the Q-band absorption where the protein microenvironment is nearly innocent in perturbing the electronic structure of the porphyrin macrocycle. Photodissociation is primarily...... maxima of heme and its complexes with amino acids and NO. Not so innocent: Weakly bound complexes between ferric heme and NO were synthesised in the gas phase, and their absorption measured from photodissociation yields. Opposite absorption trends in the Soret-band are seen upon NO addition to heme ions...

  20. Restraining Sodium Volatilization in the Ferric Bauxite Direct Reduction System

    Directory of Open Access Journals (Sweden)

    Wentao Hu

    2016-03-01

    Full Text Available Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.

  1. Gravity settling of precipitated magnetite and ferric floc

    International Nuclear Information System (INIS)

    Holt, N.S.; Loft, P.R.

    1983-06-01

    A comparison is presented of the gravity settling performance of ferric floc and magnetite, both in batch settling tests, and on a continuous gravity settler. The precipitation of magnetite from solution on a continuous basis was also demonstrated, and the process was shown not to be significantly affected by the presence of a wide range of chemical species. (U.K.)

  2. Reaction of ferric leghemoglobin with H2O2

    DEFF Research Database (Denmark)

    Moreau, S; Davies, M J; Puppo, A

    1995-01-01

    Ferric leghemoglobin in the presence of H2O2 is known to give rise to protein radicals, at least one of which is centred on a tyrosine residue. These radicals are quenched by at least two processes. The first one involves an intramolecular heme-protein cross-link probably involving the tyrosine r...

  3. Equilibrium Studies of Fluoride Adsorption onto a Ferric Poly ...

    African Journals Online (AJOL)

    African countries along the Great Rift Valley are among areas of the world where excess fluoride in water sources is a major public health problem. In this work, the removal of fluoride (F) from water solutions using a ferric poly-mineral (FPM) from Kenya was therefore studied using batch adsorption experiments. The effect of ...

  4. CU(II): catalyzed hydrazine reduction of ferric nitrate

    International Nuclear Information System (INIS)

    Karraker, D.G.

    1981-11-01

    A method is described for producing ferrous nitrate solutions by the cupric ion-catalyzed reduction of ferric nitrate with hydrazine. The reaction is complete in about 1.5 hours at 40 0 C. Hydrazoic acid is also produced in substantial quantities as a reaction byproduct

  5. Synthesis, characterization, and bioavailability in rats of ferric phosphate nanoparticles

    NARCIS (Netherlands)

    Rohner, F.; Ernst, F.O.; Arnold, M.; Hilbe, M.; Biebinger, R.; Ehrensperger, F.; Pratsinis, S.E.; Langhans, W.; Hurrell, R.F.; Zimmermann, M.B.

    2007-01-01

    Particle size is a determinant of iron (Fe) absorption from poorly soluble Fe compounds. Decreasing the particle size of metallic Fe and ferric pyrophosphate added to foods increases Fe absorption. The aim of this study was to develop and characterize nanoparticles of FePO4 and determine their

  6. Non-adiabatic Landau-Zener transitions in low-spin molecular magnet V sub 1 sub 5

    CERN Document Server

    Chiorescu, I; Müller, A; Bögge, H; Barbara, B

    2000-01-01

    The V sub 1 sub 5 polyoxovanadate molecule is made of 15 spins ((1)/(2)) with antiferromagnetic couplings. It belongs to the class of molecules with very large Hilbert space dimension (2 sup 1 sup 5 in V sub 1 sub 5 , 10 sup 8 in Mn sub 1 sub 2 -AC). It is a low spin/large molecule with spin S=((1)/(2)). Contrary to large spins/large molecules of the Mn sub 1 sub 2 -AC type, V sub 1 sub 5 has no energy barrier against spin rotation. Magnetization measurements have been performed and despite the absence of a barrier, magnetic hysteresis is observed over a timescale of several seconds. This new phenomenon characterized by a 'butterfly' hysteresis loop is due to the effect of the environment on the quantum rotation of the entangled 15 spins of the molecule, in which the phonon density of states is not at its equilibrium (phonon bottleneck).

  7. Polarized Neutron Diffraction to Probe Local Magnetic Anisotropy of a Low-Spin Fe(III) Complex.

    Science.gov (United States)

    Ridier, Karl; Mondal, Abhishake; Boilleau, Corentin; Cador, Olivier; Gillon, Béatrice; Chaboussant, Grégory; Le Guennic, Boris; Costuas, Karine; Lescouëzec, Rodrigue

    2016-03-14

    We have determined by polarized neutron diffraction (PND) the low-temperature molecular magnetic susceptibility tensor of the anisotropic low-spin complex PPh4 [Fe(III) (Tp)(CN)3]⋅H2O. We found the existence of a pronounced molecular easy magnetization axis, almost parallel to the C3 pseudo-axis of the molecule, which also corresponds to a trigonal elongation direction of the octahedral coordination sphere of the Fe(III) ion. The PND results are coherent with electron paramagnetic resonance (EPR) spectroscopy, magnetometry, and ab initio investigations. Through this particular example, we demonstrate the capabilities of PND to provide a unique, direct, and straightforward picture of the magnetic anisotropy and susceptibility tensors, offering a clear-cut way to establish magneto-structural correlations in paramagnetic molecular complexes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Thermally assisted nanosecond laser generation of ferric nanoparticles

    Science.gov (United States)

    Kurselis, K.; Kozheshkurt, V.; Kiyan, R.; Chichkov, B.; Sajti, L.

    2018-03-01

    A technique to increase nanosecond laser based production of ferric nanoparticles by elevating temperature of the iron target and controlling its surface exposure to oxygen is reported. High power near-infrared laser ablation of the iron target heated up to 600 °C enhances the particle generation efficiency by more than tenfold exceeding 6 μg/J. Temporal and thermal dependencies of the particle generation process indicate correlation of this enhancement with the oxidative processes that take place on the iron surface during the per spot interpulse delay. Nanoparticles, produced using the heat-assisted ablation technique, are examined using scanning electron and transmission electron microscopy confirming the presence of 1-100 nm nanoparticles with an exponential size distribution that contain multiple randomly oriented magnetite nanocrystallites. The described process enables the application of high power lasers and facilitates precise, uniform, and controllable direct deposition of ferric nanoparticle coatings at the industry-relevant rates.

  9. Effect of Ferric Ions on Bioleaching of Pentlandite Concentrate

    Science.gov (United States)

    Li, Qian; Lai, Huimin; Yang, Yongbin; Xu, Bin; Jiang, Tao; Zhang, Yaping

    The intensified effects of ferric phosphate and ferric sulfate as nutrient and oxidant on the bioleaching of pentlandite concentrate with Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans were studied. The results showed that the nickel leaching rate was enhanced continuously with FePO4 or Fe2(SO4)3 added in certain extent, but declined at excess. For A. ferrooxidans, the optimum additive amount of Fe2(SO4)3 was 6.63mM/L and the nickel leaching rate reached 71.76%. Compared with Fe2(SO4)3, the optimum additive amount of FePO4 was 26.52mM/L for both strains. For A. ferrooxidans and S. thermosulfidooxidans, the nickel leaching rate could increase to 98.06% and 98.11% which was 1.83 times and 1.55 times of the leachig rate of blank test, respectively.

  10. Evaluation of oral abdominal contrast agent containing ferric ammonium citrate

    International Nuclear Information System (INIS)

    Shiga, Toshiko; Kawamura, Yasutaka; Iwasaki, Toshiko

    1991-01-01

    We evaluated the effectiveness of oral MRI contrast agent containing ferric ammonium citrate. Twenty patients were arbitrarily divided into 2 groups according to the given dose of 100 and 200 mg Fe of oral MRI contrast agent. MRI was performed before and immediately after ingesting 300 ml solution of oral MRI contrast agent using a 1.5 T superconducting system (GE: Signa). Each dose of 100 and 200 mg Fe of oral MRI contrast agent produced sufficient enhancement of gastrointestinal tract, enough to make clear the pancreatic contour and porta hepatis. There was no significant change in blood and urine analysis observed after taking oral MRI contrast agent. The use of ferric ammonium citrate as an oral MRI contrast agent seems to add valuable information in performing upper abdominal MRI imaging. (author)

  11. Supramolecular Ferric Porphyrins as Cyanide Receptors in Aqueous Solution

    Science.gov (United States)

    2011-01-01

    All fundamental data about binding of the cyanide to a supramolecular complex composed of a per-O-methylated β-cyclodextrin dimer having an imidazole linker (Im3CD) and an anionic ferric porphyrin (Fe(III)TPPS) indicate that the Fe(III)TPPS/Im3CD complex is much better as an cyanide receptor in vivo than hydroxocobalamin, whose cyanide binding ability is lowered by its strong binding to serum proteins in the blood. PMID:24900285

  12. Thermodynamics of ion-exchange on ferric antimonate

    International Nuclear Information System (INIS)

    Rawat, J.P.; Muktawat, K.P.S.

    1981-01-01

    A simple approach to ion-exchange equilibria on ferric antimonate has been applied. The values of selectivity coefficients for Ba 2+ , Mg 2+ , Ca 2+ and Sr 2+ have been measured using equilibrium experiments at constant ionic strength and at different temperatures from 20 to 60 0 C. The thermodynamic equilibrium constant and values of ΔG 0 , ΔH 0 and ΔS 0 are reported. (author)

  13. Intravenous ferric carboxymaltose accelerates erythropoietic recovery from experimental malarial anemia

    DEFF Research Database (Denmark)

    Maretty, Lasse; Sharp, Rebecca Emilie; Andersson, Mikael

    2012-01-01

    Iron restriction has been proposed as a cause of erythropoietic suppression in malarial anemia; however, the role of iron in malaria remains controversial, because it may increase parasitemia. To investigate the role of iron-restricted erythropoiesis, A/J mice were infected with Plasmodium chabaudi...... use of iron therapy in malaria and show the need for trials of intravenous ferric carboxymaltose as an adjunctive treatment for severe malarial anemia....

  14. SPECTROPHOTOMETRIC ASSESSMENT OF FERRIC REDUCING POWER OF THE INSTANT COFFEE

    OpenAIRE

    Tsiupko, T. G.; Tishchenko, E. A.; Voronova, O. B.

    2016-01-01

    The methods of antioxidant activity determination of foodstuffs using different indicator systems were discussed. The investigation of ferric reducing power (FRP) of coffee and its individual phenolic components such as chlorogenic (CGA), caffeic (СА), ferulic (FA), gallic (GA), vanillic (VA), protocatechuic (PCA) and uric (UA) acids as well as quercetin (Qu) and catechol (C) using the spectrophotometric method with Fe(III) - o-Phen indicator system was carried out. It was shown that the sens...

  15. Control over the magnetism and transition between high- and low-spin states of an adatom on trilayer graphene.

    Science.gov (United States)

    Zheng, Anmin; Gao, Guoying; Huang, Hai; Gao, Jinhua; Yao, Kailun

    2017-05-31

    Using density-functional theory, we investigate the electronic and magnetic properties of an adatom (Na, Cu and Fe) on ABA- and ABC-stacked (Bernal and rhombohedral) trilayer graphenes. In particular, we study the influence of an applied gate voltage on magnetism, as it modifies the electronic states of the trilayer graphene (TLG) as well as changes the adatom spin states. Our study performed for a choice of three different adatoms (Na, Cu, and Fe) shows that the nature of adatom-graphene bonding evolves from ionic to covalent in moving from an alkali metal (Na) to a transition metal (Cu or Fe). Applying an external electric field (EEF) to TLG systems with different stacking orders results in the transition between high- and low-spin states in the latter case (Cu, Fe) and induces a little of magnetism in the former (Na) without magnetism in the absence of an external electric field. Our study would be useful for controlled adatom magnetism and (organic) spintronic applications in nanotechnology.

  16. Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

    KAUST Repository

    Ge, Qingchun; Fu, Fengjiang; Chung, Neal Tai-Shung

    2014-01-01

    Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

  17. Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

    KAUST Repository

    Ge, Qingchun

    2014-07-01

    Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

  18. Treatment of Highly Turbid Water by Polyaluminum Ferric Chloride (PAFCL

    Directory of Open Access Journals (Sweden)

    Fazel Fazel Mohammadi-Moghaddam

    2015-10-01

    Full Text Available Background & Aims of the Study: In some situation like rainfall seasons raw water become very turbid so it affected the water treatment plant processes and quality of produced water. Treatment of very high turbid water has some concerns like precursors for disinfection by-products and very loading rate of particle on filter's media and consequently increases in water consumption for filter backwash. This paper investigates the performance of a composite inorganic polymer of aluminium and ferric salt, Polyaluminium ferric chloride (PAFCl, for the removal of turbidity, color and natural organic matter (NOM from high turbid water. Materials and Methods: Experiments were carried out by Jar test experiment by synthetic water samples with 250 and 500 NTU turbidity that prepared in laboratory. Results: The results of conventional jar test showed that the optimum pH for coagulation of water sample was 7.5 to 8 and optimum dosage of the coagulant was 10 mg/L. Removal efficiency of turbidity, color and UV adsorbent at 254 nm at optimum dose and pH without filtration was 99.92%, 100% and 80.6% respectively for first sample (250 NTU and 99.95%, 99.49% and 84.77 for second sample (500 NTU respectively. Conclusion: It concluded that polyaluminium ferric chloride has a very good efficiency for the removal of turbidity, color and organic matter in high turbid water. Also it can be select as a coagulant for high turbid water and some waste water from water treatment plant like filter backwash water.

  19. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

  20. Characterizing Slow Chemical Exchange in Nucleic Acids by Carbon CEST and Low Spin-Lock Field R1ρ NMR Spectroscopy

    Science.gov (United States)

    Zhao, Bo; Hansen, Alexandar L.; Zhang, Qi

    2016-01-01

    Quantitative characterization of dynamic exchange between various conformational states provides essential insights into the molecular basis of many regulatory RNA functions. Here, we present an application of nucleic-acid-optimized carbon chemical exchange saturation transfer (CEST) and low spin-lock field R1ρ relaxation dispersion (RD) NMR experiments in characterizing slow chemical exchange in nucleic acids that is otherwise difficult if not impossible to be quantified by the ZZ-exchange NMR experiment. We demonstrated the application on a 47-nucleotide fluoride riboswitch in the ligand-free state, for which CEST and R1ρ RD profiles of base and sugar carbons revealed slow exchange dynamics involving a sparsely populated (p ~ 10%) and shortly lived (τ ~ 10 ms) NMR “invisible” state. The utility of CEST and low spin-lock field R1ρ RD experiments in studying slow exchange was further validated in characterizing an exchange as slow as ~60 s−1. PMID:24299272

  1. Characterizing slow chemical exchange in nucleic acids by carbon CEST and low spin-lock field R(1ρ) NMR spectroscopy.

    Science.gov (United States)

    Zhao, Bo; Hansen, Alexandar L; Zhang, Qi

    2014-01-08

    Quantitative characterization of dynamic exchange between various conformational states provides essential insights into the molecular basis of many regulatory RNA functions. Here, we present an application of nucleic-acid-optimized carbon chemical exchange saturation transfer (CEST) and low spin-lock field R(1ρ) relaxation dispersion (RD) NMR experiments in characterizing slow chemical exchange in nucleic acids that is otherwise difficult if not impossible to be quantified by the ZZ-exchange NMR experiment. We demonstrated the application on a 47-nucleotide fluoride riboswitch in the ligand-free state, for which CEST and R(1ρ) RD profiles of base and sugar carbons revealed slow exchange dynamics involving a sparsely populated (p ~ 10%) and shortly lived (τ ~ 10 ms) NMR "invisible" state. The utility of CEST and low spin-lock field R(1ρ) RD experiments in studying slow exchange was further validated in characterizing an exchange as slow as ~60 s(-1).

  2. Radium behaviour during ferric oxi-hydroxides crystallization

    International Nuclear Information System (INIS)

    Bassot, S.; Stammose, D.; Benitah, S.

    2004-01-01

    In uranium mill tailings, oxides and oxi-hydroxides are responsible of about 70% of the radium immobilization, half being associated to amorphous forms (mainly hydrous ferric oxides and hydrous manganese oxides). With time, crystallization of these amorphous forms can occur, inducing a redistribution of radium between solid and solution. If the amount of mobile radium increases, the impact of these tailings on the environment may become significant. The aim of this study is to determine the amount of radium released in solution during the crystallization process of hydrous ferric oxide (HFO). The transformation of Ra-HFO co-precipitate in crystallized forms (goethite, hematite, is studied by ageing at 40 deg C for different solution compositions. Both solids and solutions are sampled for different times and analysed. The solid evolution is followed by specific area measurements (about 250 m2/g for HFO and about 10-20 m 2 /g for crystallized form) and by determination of the amorphous fraction according to a selective extraction procedure. The solutions were analysed for 226 radium activity, iron concentration and pH. In order to discriminate the part of radium included in the solid and the part of radium fixed on the solid surface, radium sorption onto HFO and crystallized forms is studied as a function of pH. The modelling of the sorption curves with JCHESS 2.0 code allow to point out the mechanisms responsible of the 226-radium distribution between solid and solution during the crystallization process of HFO. (author)

  3. Arsenic removal from acidic solutions with biogenic ferric precipitates.

    Science.gov (United States)

    Ahoranta, Sarita H; Kokko, Marika E; Papirio, Stefano; Özkaya, Bestamin; Puhakka, Jaakko A

    2016-04-05

    Treatment of acidic solution containing 5g/L of Fe(II) and 10mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7h, 96-98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pHremoves iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Subsurface injection of dissolved ferric chloride to form a chemical barrier: Laboratory investigations

    International Nuclear Information System (INIS)

    Morrison, S.J.; Spangler, R.R.; Morris, S.A.

    1996-01-01

    A chemical barrier is a permeable zone of reactive materials emplaced in the subsurface to remove ground-water contaminants while allowing clean ground water to pass through. Because dissolved ferric chloride hydrolyzes to amorphous ferric oxyhydroxide when it contacts calcite (CaCO 3 ), it may be viable to emplace a zone of amorphous ferric oxyhydroxide (an absorbent for U, Mo, and other inorganic contaminants) into calcite-bearing geologic units by injecting ferric chloride through wells. For a chemical barrier to be successful, it must remain permeable and must be immobile. This investigation monitored chemical compositions, hydraulic conductivity, and iron mobility in laboratory columns and in a two-dimensional tank to determine the viability of injecting ferric chloride to form an amorphous ferric oxyhydroxide chemical barrier. The authors introduced a ferric chloride solution (1,345 mg/1[0.024 m] Fe) to calcite-bearing alluvial gravel to form a chemical barrier of amorphous ferric oxyhydroxide, followed by solutions contaminated with U and Mo. The simulated chemical barriers decreased U and Mo concentrations to less than 0.05 mg/l (2.1 x 10 -7 m) and 0.01 (1.0 x 10 -7 m), respectively; however, the breakthrough front is spread out with concentrations increasing to more than regulatory guideline values sooner than predicted. The hydraulic conductivity of calcite-bearing alluvial gravel decreased substantially during ferric chloride introduction because of the formation of carbon dioxide but increased to within factors of 1 to 5 of the original value as synthetic ground water flowed through the system. Amorphous ferric oxyhydroxide that formed in these experiments remained immobile at flow rates exceeding those typical of ground water. These laboratory results, in conjunction with site-specific characterization data, can be used to design chemical barriers emplaced by injection of ferric chloride

  5. Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

    International Nuclear Information System (INIS)

    Song Huanbi; Hu Yezang

    1997-01-01

    The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

  6. Radioisotopic synovectomy using ferric hydroxide macroaggregated for chronic arthritis treatment

    International Nuclear Information System (INIS)

    Lima, Carla Flavia; Campos, Tarcisio P.R.

    2002-01-01

    Synovectomy radioisotopic is an arthritis treatment used in specific clinical conditions whose main goal is to sterilized the synovia. This treatment has specific and precise indications and it is considered to have an adequate response. The present work presents a modeling of an articulation (joint) based on its real geometric anatomy and chemical constitution. The internal dosimetry is evaluated by the Monte Carlo Code. The majority of the radionuclides were considered in the simulations. The syntheses of the ferric hydroxide macroaggregates with dysprosium and samarium have been prepared (Dy 165 -MHF and Sm 153 -MHF). Obtaining the cintilographic images of rabbits in which Dy 165 -MHF is injected is in progress. Biodistribution studies in addition with the internal dosimetry will certify the dose in the membrane of the synovia. (author)

  7. The equilibrium leach testing of ferric/aluminium hydroxide flocs

    International Nuclear Information System (INIS)

    Biddle, P.; Greenfield, B.F.; Greenham, P.S.; Rees, J.H.

    1987-09-01

    Equilibrium leach tests have been carried out on ferric/aluminium hydroxide flocs using cement and resin matrices, and cement and clay backfills in both air and nitrogen atmospheres. The equilibrium concentrations of a number of actinides and fission products were measured in leachates obtained over periods of up to a year. The lowest equilibrium actinide concentrations were found in leachates from systems with a cement backfill. Cement matrix-cement backfill was the most promising combination for limiting concentrations of long-lived radionuclides, resin-clay the least. Comparison of leachate concentrations with limiting drinking water concentrations are made and the high degree of protection afforded by candidate near field components shown. (author)

  8. The equilibrium leach testing of ferric/aluminium hydroxide flocs

    International Nuclear Information System (INIS)

    Biddle, P.; Greenfield, B.F.; Greenham, P.S.; Rees, J.H.

    1987-09-01

    Equilibrium leach tests have been carried out on ferric/aluminium hydroxide flocs using cement and resin matrices, and cement and clay backfills in both air and nitrogen atmospheres. The equilibrium concentrations of a number of actinides and fission products were measured in leachates obtained over periods of up to a year. The lowest equilibrium actinide concentrations were found in leachates from systems with a cement backfill. Cement matrix-cement backfill was the most promising combination for limiting concentrations of long-lived radionuclides, resin-clay the least. Comparisons of leachate concentrations with limiting drinking water concentrations are made and the high degree of protection afforded by candidate near field components shown. (author)

  9. Complex sulphide-barite ore leaching in ferric chloride solution

    Directory of Open Access Journals (Sweden)

    Miroslav Sokić

    2016-06-01

    Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

  10. Ferric oxide quantum dots in stable phosphate glass system and their magneto-optical study

    Energy Technology Data Exchange (ETDEWEB)

    Garaje, Sunil N.; Apte, Sanjay K. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Kumar, Ganpathy [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Panmand, Rajendra P.; Naik, Sonali D. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Mahajan, Satish M., E-mail: smahajan@tntech.edu [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Chand, Ramesh [Ministry of Communications and Information Technology, Department of Electronics and Information Technology (DeitY), Electronics Niketan, 6, CGO Complex, New Delhi 110003 (India); Kale, Bharat B., E-mail: bbkale@cmet.gov.in [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India)

    2013-02-15

    Graphical abstract: We report synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles (NCs) content on the optical and magneto-optical properties of the glasses. Faraday rotation of the glass nanocomposites was measured and showed variation in Verdet constant with concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and there is a threefold enhancement in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. Highlights: ► We synthesize ferric oxide embedded low melting stable phosphate glass nanocomposite. ► Glasses doped with 0.25 and 2% ferric oxide show particle size in the range of 4–12 nm. ► The host phosphate glass itself shows fairly good Verdet constant (11.5°/T cm). ► Glasses doped with 0.25% ferric oxide show high Verdet constant (30.525°/T cm). ► The as synthesis glasses may have potential application in magneto optical devices. -- Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48 eV and it shifted to 3.14 eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6 nm and 8–12 nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite.

  11. Transcriptional regulation by Ferric Uptake Regulator (Fur) in pathogenic bacteria.

    Science.gov (United States)

    Troxell, Bryan; Hassan, Hosni M

    2013-01-01

    In the ancient anaerobic environment, ferrous iron (Fe(2+)) was one of the first metal cofactors. Oxygenation of the ancient world challenged bacteria to acquire the insoluble ferric iron (Fe(3+)) and later to defend against reactive oxygen species (ROS) generated by the Fenton chemistry. To acquire Fe(3+), bacteria produce low-molecular weight compounds, known as siderophores, which have extremely high affinity for Fe(3+). However, during infection the host restricts iron from pathogens by producing iron- and siderophore-chelating proteins, by exporting iron from intracellular pathogen-containing compartments, and by limiting absorption of dietary iron. Ferric Uptake Regulator (Fur) is a transcription factor which utilizes Fe(2+) as a corepressor and represses siderophore synthesis in pathogens. Fur, directly or indirectly, controls expression of enzymes that protect against ROS damage. Thus, the challenges of iron homeostasis and defense against ROS are addressed via Fur. Although the role of Fur as a repressor is well-documented, emerging evidence demonstrates that Fur can function as an activator. Fur activation can occur through three distinct mechanisms (1) indirectly via small RNAs, (2) binding at cis regulatory elements that enhance recruitment of the RNA polymerase holoenzyme (RNAP), and (3) functioning as an antirepressor by removing or blocking DNA binding of a repressor of transcription. In addition, Fur homologs control defense against peroxide stress (PerR) and control uptake of other metals such as zinc (Zur) and manganese (Mur) in pathogenic bacteria. Fur family members are important for virulence within bacterial pathogens since mutants of fur, perR, or zur exhibit reduced virulence within numerous animal and plant models of infection. This review focuses on the breadth of Fur regulation in pathogenic bacteria.

  12. Arsenic removal from acidic solutions with biogenic ferric precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Ahoranta, Sarita H., E-mail: sarita.ahoranta@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Kokko, Marika E., E-mail: marika.kokko@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Papirio, Stefano, E-mail: stefano.papirio@unicas.it [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Özkaya, Bestamin, E-mail: bozkaya@yildiz.edu.tr [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Department of Environmental Engineering, Yildiz Technical University, Davutpasa Campus 34220, Esenler, Istanbul (Turkey); Puhakka, Jaakko A., E-mail: jaakko.puhakka@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland)

    2016-04-05

    Highlights: • Continuous and rapid arsenic removal with biogenic jarosite was achieved at pH 3.0. • Arsenic removal was inefficient below pH 2.4 due to reduced Fe–As co-precipitation. • As(V) had better sorption characteristics than As(III). • Biogenic jarosite adsorbed arsenic more effectively than synthetic jarosite. - Abstract: Treatment of acidic solution containing 5 g/L of Fe(II) and 10 mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7 h, 96–98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28 mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pH < 2.4. As(III) was partially oxidized to As(V) in the system. In shake flask experiments, As(V) sorbed onto jarosite better than As(III). Moreover, the sorption capacity of biogenic jarosite was significantly higher than that of synthetic jarosite. The developed bioprocess simultaneously and efficiently removes iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment.

  13. The absorption and transportation of ferric-salt in apple trees

    International Nuclear Information System (INIS)

    Xiong Zhixun; Chen Meihong

    1994-01-01

    59 Fe tracer technique was used to study the ferric-salt absorption, utilization and transportation in apple trees. The results indicated that absorption and utilization rate of ferric salt was 0.056%∼0.110% for roots and 30% for leaves, and that Fe is not easily to be transferred from one part to another. Fulvic acid iron had a better effect than ferrous sulfate. Ferric-salt absorption, utilization and transference were different among the cultivars. Intensive injections of ferrous salt into the apple trunks seemed to be more effective for correcting of chlorosis

  14. Mössbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    Science.gov (United States)

    Jaén, Juan A.; Navarro, César

    2009-07-01

    Fourier transform infrared spectroscopy and Mössbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Mössbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  15. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    International Nuclear Information System (INIS)

    Jaen, Juan A.; Navarro, Cesar

    2009-01-01

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  16. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Depto. de Quimica Fisica, CITEN, Lab. No. 105, Edificio de Laboratorios Cientificos-VIP (Panama); Navarro, Cesar [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2009-07-15

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  17. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    Directory of Open Access Journals (Sweden)

    Ma D.

    2013-01-01

    Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

  18. Iron fortification of flour with a complex ferric orthophosphate

    International Nuclear Information System (INIS)

    Hallberg, L.; Rossander-Hulthen, L.; Gramatkovski, E.

    1989-01-01

    The unexpectedly low bioavailability in humans of elemental iron powder prompted us to search for other Fe compounds suitable for Fe fortification of flour that fulfill the two requirements of insolubility in water (due to high water content of flour) and good bioavailability in humans. Systematic studies of compatibility, solubility, and bioavailability led to this study of a microcrystalline complex ferric orthophosphate (CFOP), Fe 3 H 8 (NH 4 )-(PO 4 )6.6H 2 O, a well-defined compound. This compound was labeled with 59 Fe, and the native Fe in meals was labeled with 55 FeCl3. The ratio of absorbed 59 Fe to absorbed 55 Fe is a direct measure of the fraction of CFOP that joins the nonheme Fe pool and that is made potentially available for absorption. The relative bioavailability of CFOP varied from 30% to 60% when labeled wheat rolls were served with different meals. The CFOP meets practical requirements of an Fe fortificant for flour well, with regard to both compatibility and bioavailability in humans

  19. Dietary bioavailability of Cu adsorbed to colloidal hydrous ferric oxide

    Science.gov (United States)

    Cain, Daniel J.; Croteau, Marie-Noële; Fuller, Christopher C.

    2013-01-01

    The dietary bioavailability of copper (Cu) adsorbed to synthetic colloidal hydrous ferric oxide (HFO) was evaluated from the assimilation of 65Cu by two benthic grazers, a gastropod and a larval mayfly. HFO was synthesized, labeled with 65Cu to achieve a Cu/Fe ratio comparable to that determined in naturally formed HFO, and then aged. The labeled colloids were mixed with a food source (the diatom Nitzschia palea) to yield dietary 65Cu concentrations ranging from 211 to 2204 nmol/g (dry weight). Animals were pulse fed the contaminated diet and assimilation of 65Cu from HFO was determined following 1–3 days of depuration. Mass transfer of 65Cu from HFO to the diatom was less than 1%, indicating that HFO was the source of 65Cu to the grazers. Estimates of assimilation efficiency indicated that the majority of Cu ingested as HFO was assimilated (values >70%), implying that colloidal HFO potentially represents a source of dietary Cu to benthic grazers, especially where there is active formation and infiltration of these particles into benthic substrates.

  20. Synthesis and characterization of redox-active ferric nontronite

    Energy Technology Data Exchange (ETDEWEB)

    Ilgen, A. G.; Kukkadapu, R. K.; Dunphy, D. R.; Artyushkova, K.; Cerrato, J. M.; Kruichak, J. N.; Janish, M. T.; Sun, C. J.; Argo, J. M.; Washington, R. E.

    2017-10-01

    Heterogeneous redox reactions on clay mineral surfaces control mobility and bioavailability of redox-sensitive nutrients and contaminants. Iron (Fe) residing in clay mineral structures can either catalyze or directly participate in redox reactions; however, chemical controls over its reactivity are not fully understood. In our previous work we demonstrated that converting a minor portion of Fe(III) to Fe(II) (partial reduction) in the octahedral sheet of natural Fe-rich clay mineral nontronite (NAu-1) activates its surface, making it redox-active. In this study we produced and characterized synthetic ferric nontronite (SIP), highlighting structural and chemical similarities and differences between this synthetic nontronite and its natural counterpart NAu-1, and probed whether mineral surface is redox-active by reacting it with arsenic As(III) under oxic and anoxic conditions. We demonstrate that synthetic nontronite SIP undergoes the same activation as natural nontronite NAu-1 following the partial reduction treatment. Similar to NAu-1, SIP oxidized As(III) to As(V) under both oxic (catalytic pathway) and anoxic (direct oxidation) conditions. The similar reactivity trends observed for synthetic nontronite and its natural counterpart make SIP an appropriate analog for laboratory studies. The development of chemically pure analogs for ubiquitous soil minerals will allow for systematic research of the fundamental properties of these minerals.

  1. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

    2013-01-01

    Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

  2. Characterization of ferric arsenate-sulfate compounds: Implications for arsenic control in refractory gold processing residues

    Czech Academy of Sciences Publication Activity Database

    Paktunc, D.; Majzlan, J.; Palatinus, Lukáš; Dutrizac, J.; Klementová, Mariana; Poirier, G.

    2013-01-01

    Roč. 98, č. 4 (2013), s. 554-565 ISSN 0003-004X Institutional support: RVO:68378271 Keywords : arsenic * ferric arsenate sulfate * autoclave residue * hydrometallurgy Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.059, year: 2013

  3. Oxidation of Alcohols by Ferric Nitrate in the Presence of Barium ...

    African Journals Online (AJOL)

    NJD

    Oxidation, ferric nitrate, barium chloride, silica sulphuric acid, heterogeneous or solvent-free conditions. 1. Introduction ... economic advantage and environment protection. ... by TLC. After completion, structure of the product was charac-.

  4. Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

    International Nuclear Information System (INIS)

    Rouas, C.

    1988-12-01

    A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry [fr

  5. Ferric-Pyoverdine Recognition by Fpv Outer Membrane Proteins of Pseudomonas protegens Pf-5

    Science.gov (United States)

    Hartney, Sierra L.; Mazurier, Sylvie; Girard, Maëva K.; Mehnaz, Samina; Davis, Edward W.; Gross, Harald; Lemanceau, Philippe

    2013-01-01

    The soil bacterium Pseudomonas protegens Pf-5 (previously called P. fluorescens Pf-5) produces two siderophores, enantio-pyochelin and a compound in the large and diverse pyoverdine family. Using high-resolution mass spectroscopy, we determined the structure of the pyoverdine produced by Pf-5. In addition to producing its own siderophores, Pf-5 also utilizes ferric complexes of some pyoverdines produced by other strains of Pseudomonas spp. as sources of iron. Previously, phylogenetic analysis of the 45 TonB-dependent outer membrane proteins in Pf-5 indicated that six are in a well-supported clade with ferric-pyoverdine receptors (Fpvs) from other Pseudomonas spp. We used a combination of phylogenetics, bioinformatics, mutagenesis, pyoverdine structural determinations, and cross-feeding bioassays to assign specific ferric-pyoverdine substrates to each of the six Fpvs of Pf-5. We identified at least one ferric-pyoverdine that was taken up by each of the six Fpvs of Pf-5. Functional redundancy of the Pf-5 Fpvs was also apparent, with some ferric-pyoverdines taken up by all mutants with a single Fpv deletion but not by a mutant having deletions in two of the Fpv-encoding genes. Finally, we demonstrated that phylogenetically related Fpvs take up ferric complexes of structurally related pyoverdines, thereby establishing structure-function relationships that can be employed in the future to predict the pyoverdine substrates of Fpvs in other Pseudomonas spp. PMID:23222724

  6. Binding of ferric ions is essential for the biological activity of glycine-extended gastrin

    International Nuclear Information System (INIS)

    Baldwin, G.S.; Pannequin, J.; Hollande, F.; Shulkes, A.

    2002-01-01

    Full text: Non-amidated gastrins, such as glycine-extended gastrin17 (Ggly), are now known to be biologically active. Ggly stimulates cell proliferation and migration, and was recently shown to bind two ferric ions with high affinity. The objective of the present work was to define the structure of Ggly for the first time, and to investigate the role of ferric ions in biological activity. Methods: The structure of Ggly, and the identity of the ammo acids that act as ferric ion ligands, were determined by NMR and fluorescence spectroscopy. The effect on the gastric epithelial cell line IMGE-5 of Ggly fragments, and of Ggy mutants with some or all of the five consecutive glutamate residues replaced by alanine, was measured in terms of cell proliferation, cell migration and phosphorylation of focal adhesion kinase. Results: Ggly adopts a well-defined loop stabilised by hydrophobic interactions between Leu5, Tyrl2, Trp 14 and Phe17. Studies with Ggly fragments indicated that ferric ions bind via the pentaglutamate sequence, which is necessary but not sufficient for full activity Selective replacement of some or all of the glutamates results in a reduction in ferric ion binding, and complete loss of biological activity. Conclusion: Our results are consistent with the hypothesis that ferric ion binding is necessary for biological activity

  7. Cost-minimization analysis favours intravenous ferric carboxymaltose over ferric sucrose for the ambulatory treatment of severe iron deficiency.

    Directory of Open Access Journals (Sweden)

    Xavier Calvet

    Full Text Available OBJECTIVE: Intravenous iron is widely used to treat iron deficiency in day-care units. Ferric carboxymaltose (FCM allows administration of larger iron doses than iron sucrose (IS in each infusion (1000 mg vs. 200 mg. As FCM reduces the number of infusions required but is more expensive, we performed a cost-minimization analysis to compare the cost impact of the two drugs. MATERIALS AND METHODS: The number of infusions and the iron dose of 111 consecutive patients who received intravenous iron at a gastrointestinal diseases day-care unit from 8/2007 to 7/2008 were retrospectively obtained. Costs of intravenous iron drugs were obtained from the Spanish regulatory agencies. The accounting department of the Hospital determined hospital direct and indirect costs for outpatient iron infusion. Non-hospital direct costs were calculated on the basis of patient interviews. In the pharmacoeconomic model, base case mean costs per patient were calculated for administering 1000 mg of iron per infusion using FCM or 200 mg using IS. Sensitivity analysis and Monte Carlo simulation were performed. RESULTS: Under baseline assumptions, the estimated cost of iron infusion per patient and year was €304 for IS and €274 for FCM, a difference of €30 in favour of FCM. Adding non-hospital direct costs to the model increased the difference to €67 (€354 for IS vs. €287 for FCM. A Monte Carlo simulation taking into account non-hospital direct costs favoured the use of FCM in 97% of simulations. CONCLUSION: In this pharmacoeconomic analysis, FCM infusion reduced the costs of iron infusion at a gastrointestinal day-care unit.

  8. The decay of /sup 185/Hg low-spin states in /sup 185/Au as a probe of the nuclear models

    CERN Document Server

    Bourgeois, C; Kilcher, P; Roussière, B; Sauvage-Letessier, J

    1981-01-01

    The /sup 185/Au has been studied from the beta /sup +//EC decay of /sup 185m+g/Hg using the ISOCELE facility. Conversion electron measurements have been performed by means of a semi-circular magnetic spectrograph: new low-energy transitions have been observed. A 330 keV very converted transition has also been found. Its existence is discussed. In addition to the usual states observed in heavier gold isotopes, numerous negative-parity low-spin states have been located. The experimental states corresponding to a prolate shaped nucleus are compared with those extracted from an 'axial rotor+quasi-particle' coupling model. They could be identified with two state families, the first one arising from the h9/2+f5/2 sub-shells, the second from the p3/2+f7/2 sub-shells. (12 refs).

  9. Assignment of hyperfine shifted haem methyl carbon resonances in paramagnetic low-spin met-cyano complex of sperm whale myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yasuhiko

    1987-09-28

    The hyperfine shifted resonances arising from all four individual haem carbons of the paramagnetic low-spin met-cyano complex of sperm whale myoglobin have been clearly identified and assigned for the first time with the aid of /sup 1/H-/sup 13/C heteronuclear chemical shift correlated spectroscopy. Alteration of the in-plane symmetry of the electronic structure of haem induced by the ligation of proximal histidyl imidazole spreads the haem carbon resonances to 32 ppm at 22/sup 0/C, indicating the sensitivity of those resonances to the haem electronic/molecular structure. Those resonances are potentially powerful probes in characterizing the nature of haem electronic structure. 25 refs.; 2 figs.; 1 table.

  10. Cyanide binding to ferrous and ferric microperoxidase-11.

    Science.gov (United States)

    Ascenzi, Paolo; Sbardella, Diego; Santucci, Roberto; Coletta, Massimo

    2016-07-01

    Microperoxidase-11 (MP11) is an undecapeptide derived from horse heart cytochrome c (cytc). MP11 is characterized by a covalently linked solvent-exposed heme group, the heme-Fe atom being axially coordinated by a histidyl residue. Here, the reactions of ferrous and ferric MP11 (MP11-Fe(II) and MP11-Fe(III), respectively) with cyanide have been investigated from the kinetic and thermodynamic viewpoints, at pH 7.0 and 20.0 °C. Values of the second-order rate constant for cyanide binding to MP11-Fe(II) and MP11-Fe(III) are 4.5 M(-1) s(-1) and 8.9 × 10(3) M(-1) s(-1), respectively. Values of the first-order rate constant for cyanide dissociation from ligated MP11-Fe(II) and MP11-Fe(III) are 1.8 × 10(-1) s(-1) and 1.5 × 10(-3) s(-1), respectively. Values of the dissociation equilibrium constant for cyanide binding to MP11-Fe(II) and MP11-Fe(III) are 3.7 × 10(-2) and 1.7 × 10(-7) M, respectively, matching very well with those calculated from kinetic parameters so that no intermediate species seem to be involved in the ligand-binding process. The pH-dependence of cyanide binding to MP11-Fe(III) indicates that CN(-) is the only binding species. Present results have been analyzed in parallel with those of several heme-proteins, suggesting that (1) the ligand accessibility to the metal center and cyanide ionization may modulate the formation of heme-Fe-cyanide complexes, and (2) the general polarity of the heme pocket and/or hydrogen bonding of the heme-bound ligand may affect cyanide exit from the protein matrix. Microperoxidase-11 (MP11) is an undecapeptide derived from horse heart cytochrome c. Penta-coordinated MP11 displays a very high reactivity towards cyanide, whereas the reactivity of hexa-coordinated horse heart cytochrome c is very low.

  11. Evolution of the local structure of ferric gels and polymers during the crystallisation of iron oxides. Application to uranium trapping

    International Nuclear Information System (INIS)

    Combes, Jean-Marie

    1988-01-01

    A first part of this research thesis reports the study of the structure of the main iron oxides and oxy-hydroxides, and of the protocols for the synthesis of ferric gels. The second part reports a topological approach by EXAFS (Extended X-Ray Absorption Fine Structure) of the structure of Mn and Fe oxides and oxy-hydroxides. The third part reports the study of the formation of ferric oxides from aqueous solutions by using a polyhedral approach by X-ray absorption spectroscopy in the case of hydrolysis and formation of ferric gels, and in the case of haematite formation from ferric gels. The next parts respectively report the study of the local structure of gels synthesised from iron(II), and the study of the local structure of natural ferric gels. Then, the author reports the study of sites of uranium bonding on ferric gels [fr

  12. Laser photoelectron spectroscopy of MnH - and FeH - : Electronic structures of the metal hydrides, identification of a low-spin excited state of MnH, and evidence for a low-spin ground state of FeH

    Science.gov (United States)

    Stevens, Amy E.; Feigerle, C. S.; Lineberger, W. C.

    1983-05-01

    The laser photoelectron spectra of MnH- and MnD-, and FeH- and FeD- are reported. A qualitative description of the electronic structure of the low-spin and high-spin states of the metal hydrides is developed, and used to interpret the spectra. A diagonal transition in the photodetachment to the known high-spin, 7Σ+, ground state of MnH is observed. An intense off-diagonal transition to a state of MnH, at 1725±50 cm-1 excitation energy, is attributed to loss of an antibonding electron from MnH-, to yield a low-spin quintet state of MnH. For FeH- the photodetachment to the ground state is an off-diagonal transition, attributed to loss of the antibonding electron from FeH-, to yield a low-spin quartet ground state of FeH. A diagonal transition results in an FeH state at 1945±55 cm-1; this state of FeH is assigned as the lowest-lying high-spin sextet state of FeH. An additional excited state of MnH and two other excited states of FeH are observed. Excitation energies for all the states are reported; vibrational frequencies and bond lengths for the ions and several states of the neutrals are also determined from the spectra. The electron affinity of MnH is found to be 0.869±0.010 eV; and the electron affinity of FeH is determined to be 0.934±0.011 eV. Spectroscopic constants for the various deuterides are also reported.

  13. Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network

    Directory of Open Access Journals (Sweden)

    Golmohammadi Hassan

    2013-01-01

    Full Text Available A quantitative structure-property relationship (QSPR study based on partial least squares (PLS and artificial neural network (ANN was developed for the prediction of ferric iron precipitation in bioleaching process. The leaching temperature, initial pH, oxidation/reduction potential (ORP, ferrous concentration and particle size of ore were used as inputs to the network. The output of the model was ferric iron precipitation. The optimal condition of the neural network was obtained by adjusting various parameters by trial-and-error. After optimization and training of the network according to back-propagation algorithm, a 5-5-1 neural network was generated for prediction of ferric iron precipitation. The root mean square error for the neural network calculated ferric iron precipitation for training, prediction and validation set are 32.860, 40.739 and 35.890, respectively, which are smaller than those obtained by PLS model (180.972, 165.047 and 149.950, respectively. Results obtained reveal the reliability and good predictivity of neural network model for the prediction of ferric iron precipitation in bioleaching process.

  14. Evaluation of Ferric and Ferrous Iron Therapies in Women with Iron Deficiency Anaemia

    Science.gov (United States)

    Berber, Ilhami; Erkurt, Mehmet Ali; Aydogdu, Ismet; Kuku, Irfan

    2014-01-01

    Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiology and treatment of the underlying aetiology, the ferric group consisted of 30 patients treated with oral ferric protein succinylate tablets (2 × 40 mg elemental iron/day), and the second group consisted of 34 patients treated with oral ferrous glycine sulphate tablets (2 × 40 mg elemental iron/day) for three months. In all patients, the following laboratory evaluations were performed before beginning treatment and after treatment. Results. The mean haemoglobin and haematocrit increases were 0.95 g/dL and 2.62% in the ferric group, while they were 2.25 g/dL and 5.91% in the ferrous group, respectively. A significant difference was found between the groups regarding the increase in haemoglobin and haematocrit values (P < 0.05). Conclusion. Data are submitted on the good tolerability, higher efficacy, and lower cost of the ferrous preparation used in our study. PMID:25006339

  15. Role of Intravenous Ferric Carboxy-maltose in Pregnant Women with Iron Deficiency Anaemia.

    Science.gov (United States)

    Mishra, Vineet; Gandhi, Khusaili; Roy, Priyankur; Hokabaj, Shaheen; Shah, Kunur N

    2017-09-08

    Iron deficiency is a common nutritional deficiency amongst women of childbearing age. Peri-partum iron deficiency anaemia is associated with significant maternal, foetal and infant morbidity. Current options for treatment include oral iron, which can be ineffective and poorly tolerated, and red blood cell transfusions, which carry an inherent risk and should be avoided. Ferric carboxymaltose is a modern treatment option. The study was designed to assess the safety and efficacy of intravenous ferric carboxymaltose for correction of iron deficiency anaemia in pregnant women. A prospective study was conducted at Institute of Kidney Disease and Research Centre, Ahmedabad from January 2014 to December 2016. Antenatal women (108) with iron deficiency anaemia were the study subjects. Socio-demographic profile was recorded and anaemia was assessed based on recent haemoglobin reports. Iron deficiency was diagnosed on basis of serum ferritin value. Intravenous ferric carboxymaltose as per total correction dose (maximum 1500mg) was administered to all women; the improvement in haemoglobin levels were assessed after 3 weeks of total dose infusion. Most of the women(n= 45, 41.7%), were in the age group of 27-30 years. Most of the women (n = 64, 59.3%) had moderate anaemia as per WHO guidelines. Mean haemoglobin levels significantly increased over a period of 3 weeks after Ferric carboxymaltose administrationand no serious life threatening adverse events were observed. Intravenous ferric carboxymaltose was safe and effective in pregnent women with iron deficiency anaemia.

  16. Ferric hydroxide supported gold subnano clusters or quantum dots: enhanced catalytic performance in chemoselective hydrogenation.

    Science.gov (United States)

    Liu, Lequan; Qiao, Botao; Ma, Yubo; Zhang, Juan; Deng, Youquan

    2008-05-21

    An attempt to prepare ferric hydroxide supported Au subnano clusters via modified co-precipitation without any calcination was made. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been employed to study the structure and chemical states of these catalysts. No Au species could be observed in the HRTEM image nor from the XRD pattern, suggesting that the sizes of the Au species in and on the ferric hydroxide support were less than or around 1 nm. Chemoselective hydrogenation of aromatic nitro compounds and alpha,beta-unsaturated aldehydes was selected as a probe reaction to examine the catalytic properties of this catalyst. Under the same reaction conditions, such as 100 degrees C and 1 MPa H2 in the hydrogenation of aromatic nitro compounds, a 96-99% conversion (except for 4-nitrobenzonitrile) with 99% selectivity was obtained over the ferric hydroxide supported Au catalyst, and the TOF values were 2-6 times higher than that of the corresponding ferric oxide supported catalyst with 3-5 nm size Au particles. For further evaluation of this Au catalyst in the hydrogenation of citral and cinnamaldehyde, selectivity towards unsaturated alcohols was 2-20 times higher than that of the corresponding ferric oxide Au catalyst.

  17. Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254 nm UV light

    International Nuclear Information System (INIS)

    Wang Yuan; Zhang Pengyi; Pan Gang; Chen Hao

    2008-01-01

    The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254 nm UV light was reported. In the presence of 10 μM ferric ion, 47.3% of initial PFOA (48 μM) was decomposed and the defluorination ratio reached 15.4% within 4 h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80 μM, and the corresponding half-life was shortened to 103 min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu 2+ and Zn 2+ also slightly improved the photochemical decomposition of PFOA under irradiation of 254 nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280 nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254 nm UV light leads to the decomposition of PFOA in a stepwise way

  18. Low-spin structure of 51,35,86Br and 50,36,86Kr nuclei: The role of the g7 /2 neutron orbital

    Science.gov (United States)

    Urban, W.; Sieja, K.; Materna, T.; Czerwiński, M.; Rząca-Urban, T.; Blanc, A.; Jentschel, M.; Mutti, P.; Köster, U.; Soldner, T.; de France, G.; Simpson, G. S.; Ur, C. A.; Bernards, C.; Fransen, C.; Jolie, J.; Regis, J.-M.; Thomas, T.; Warr, N.

    2016-10-01

    Low-spin excited levels in 51,35,86Br and 50,36,86Kr, populated following β- decay and the neutron-induced fission of 235U, were measured using the Lohengrin fission-fragment separator and the EXILL array of Ge detectors at the PF1B cold-neutron facility of the Institute Laue-Langevin Grenoble. Improved populations of excited levels in 86Br remove inconsistencies existing in the literature on this nucleus. Directional-linear-polarization correlations, analyzed using newly developed formulas, as well as precise angular correlations allowed the unique 1- and 2- spin and parity assignments to the ground state of 86Br and the 4016.3-keV level in 86Kr, respectively. Based on these results we propose that the Gamow-Teller β- decays of 86Se and 86Br involve the ν g7 /2→π g9 /2 transition in addition to the ν p3 /2→π p3 /2 transition proposed earlier. In 86Kr we have identified 11+, 23+, and 31+ levels, analogous to the mixed-symmetry states in 94Mo, which in 86Kr are from proton excitations, only. Large-scale, shell-model calculations with refined interactions reproduce well excitations in 86Br and 86Kr and support our interpretations.

  19. EPR of some low-spin dsup(5) tris-chelate complexes of Fe(3), Ru(3), Os(3) in liquid-crystal matrix

    International Nuclear Information System (INIS)

    Domracheva, N.E.; Konstantinov, V.N.; Luchkona, S.A.; Ovchinnikov, I.V.

    1985-01-01

    Using the EPR method low-spin trischelate complexes of Fe, Ru, Os with 8-mercaptoquinoline and 8-oxyquinoline in oriented vitrified liquid-crystal matrix have been studied. Analtysis of angular dependences of EPR spectra of the complexes permitted to correlate the main axes of g-tensor with molecular axes and, consequently, to determine unambiguously the main electron states of the systems, as well as the value of crystal splittings. It is shown that in the complexes studied the splitting of energy levels is mainly determined by spin-orbital interaction, and not by axial or rhombic components of crystal field. However, rhombic distortion is responsible for anisotropy of g-tensor in xy plane and anisotropy of x- and y-axes orientation. The way to orient complexes in liquid-crystal matrix is substantiated; symmetry axis of the third order C 3 (Z) is mainly oriented along the director. Parameters of the function of orientational distribution of the complex axes are obtained

  20. THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

    Directory of Open Access Journals (Sweden)

    Ivan Osipov

    2015-12-01

    Full Text Available Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.

  1. Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-12-01

    Full Text Available Aim: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. Materials and Methods: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM. Results: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. Conclusion: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

  2. Evaluation of hydrous ferric oxide loaded activated carbon as a granular composite sorbent for radiostrontium

    International Nuclear Information System (INIS)

    Samanta, S.K.

    1997-01-01

    A composite sorbent was prepared in granular form by depositing hydrous ferric oxide inside the pores of activated carbon. The composite sorbent was found to show excellent sorption of radiostrontium in the presence of high sodium concentration under alkaline conditions. (author). 3 refs., 2 figs., 1 tab

  3. Part 5: Experimental periods using a ferrous-ferric chloride blend

    African Journals Online (AJOL)

    drinie

    A blend of ferrous chloride and ferric chloride (FeCl2-FeCl3) was simultaneously dosed into an activated sludge system at .... theoretical oxygen demand for this reaction is small, namely 0.15 ...... The role of bacterial extracellular polymers.

  4. Safety and Efficacy of Ferric Carboxymaltose in Anemic Pregnant Women: A Retrospective Case Control Study

    NARCIS (Netherlands)

    Pels, Anouk; Ganzevoort, Wessel

    2015-01-01

    Background. Anemia during pregnancy is commonly caused by iron deficiency and can have severe consequences for both the mother and the developing fetus. The aim of this retrospective study was to assess the safety and efficacy of intravenous ferric carboxymaltose (FCM) in pregnant women. Methods.

  5. Photoexcitation dynamics of nitric oxide bound ferric myoglobin probed by femtosecond IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Park Jaehun

    2013-03-01

    Full Text Available Time-resolved vibrational spectra show that photolysis quantum yield of NO bound ferric myoglobin is smaller than 0.86, the deligated NO geminately rebinds with subnanosecond time scale, and the rebinding kinetics depends on protein conformation.

  6. Ferric carboxymaltose prevents recurrence of anemia in patients with inflammatory bowel disease

    DEFF Research Database (Denmark)

    Evstatiev, Rayko; Alexeeva, Olga; Bokemeyer, Bernd

    2013-01-01

    Iron-deficiency anemia is the most common systemic complication of inflammatory bowel diseases (IBD). Iron-deficiency anemia recurs frequently and rapidly after iron-replacement therapy in patients with IBD. We performed a randomized, placebo-controlled trial to determine if administration...... of ferric carboxymaltose (FCM) prevents anemia in patients with IBD and low levels of serum ferritin....

  7. Electrical conduction studies in ferric-doped KHSO 4 single crystals

    Science.gov (United States)

    Sharon, M.; Kalia, A. K.

    1980-03-01

    Direct-current conductivity of ferric-doped (138, 267, and 490 ppm) single crystals of KHSO 4 has been studied. The mechanism for the dc conduction process is discussed. It is observed that the ferric ion forms a (Fe 3+-two vacancies) complex and the enthaply for its formation is 0.09 ± 0.01 eV. It is proposed that each ferric ion removes two protons from each HSO 4 dimer. The conductivity plot shows the presence of intrinsic and extrinsic regions. It is proposed that in the intrinsic region the dimer of HSO -4 breaks reversibly to form a long-chain monomer-type structure. The conductivity in the KHSO 4 crystal is proposed to be controlled by the rotation of HSO -4 tetrahedra along the axis which contains no hydrogen atom. Isotherm calculation for the trivalent-doped system is applied to this crystal and the results are compared with Co 2+-doped KHSO 4 crystal. The distribution coefficient of ferric ion in the KHSO 4 single crystal is calculated to be 4.5 × 10 -1. Ferric ion causes tapering in the crystal growth habit of KHSO 4 and it is believed to be due to the presence of (Fe 3+-two vacancies) complex. The enthalpy values for the various other processes are as follows: enthalpy for the breakage of HSO -4 dimer ( Hi) = 1.28 ± 0.01 eV; enthalpy for the rotation of HSO -4 tetrahedron ( Hm) = 0.58 ± 0.01 eV.

  8. Reduction of ferric iron by acidophilic heterotrophic bacteria: evidence for constitutive and inducible enzyme systems in Acidiphilium spp.

    Science.gov (United States)

    Johnson, D B; Bridge, T A M

    2002-01-01

    To compare the abilities of two obligately acidophilic heterotrophic bacteria, Acidiphilium acidophilum and Acidiphilium SJH, to reduce ferric iron to ferrous when grown under different culture conditions. Bacteria were grown in batch culture, under different aeration status, and in the presence of either ferrous or ferric iron. The specific rates of ferric iron reduction by fermenter-grown Acidiphilium SJH were unaffected by dissolved oxygen (DO) concentrations, while iron reduction by A. acidophilum was highly dependent on DO concentrations in the growth media. The ionic form of iron present (ferrous or ferric) had a minimal effect on the abilities of harvested cells to reduce ferric iron. Whole cell protein profiles of Acidiphilium SJH were very similar, regardless of the DO status of the growth medium, while additional proteins were present in A. acidophilum grown microaerobically compared with aerobically-grown cells. The dissimilatory reduction of ferric iron is constitutive in Acidiphilium SJH while it is inducible in A. acidophilum. Ferric iron reduction by Acidiphilium spp. may occur in oxygen-containing as well as anoxic acidic environments. This will detract from the effectiveness of bioremediation systems where removal of iron from polluted waters is mediated via oxidation and precipitation of the metal.

  9. The influence of surfactant on the synthesis of gamma ferric oxide: implications on phase composition and magnetic properties

    International Nuclear Information System (INIS)

    Narasimhan, B.R.V.; Prabhakar, S.; Manohar, P.; Gnanam, F.D.

    2002-01-01

    It has already been established that ferrous carbonate precipitated from the reaction of ferrous sulphate and sodium carbonate, on direct thermal decomposition yields gamma ferric oxide. The present work describes the effect of sodium lauryl sulphate (Sodium dodecyl sulphate) on the synthesis of gamma ferric oxide when it is introduced during the precipitation of ferrous carbonate. Since ferrous carbonate undergoes rapid oxidation on standing in air, the extent of oxidation in presence of sodium lauryl sulphate is also studied using oxidation-reduction potential measurements. The ferric oxide powders are characterized for phase analysis (XRD), magnetic properties (VSM) and particle size analysis. (author)

  10. Preparation of ferric acetylacetonate, bonzonate and caprate labelled with Fe-55 and tests of application to liquid scintillation measurements

    International Nuclear Information System (INIS)

    Los Arcos, J.M.; Rodriguez Barquero, L.; Grau Malonda, A.

    1990-01-01

    The methods of preparation of ferric acetylacetonate, benzoate and caprate labelled with 55 Fe are described. The quenching effect, the spectral baehaviour and the count rate stability are studied by liquid scintillation measurements in toluene, INSTAGEL and HISAFE II, for two different values of the sample concentration. The ferric acetylaceton-ate is stable for all the three scintillators but shows a strong quench, while the ferric benzoate and caprate are stable only for INSTAGEL and HISAFE II showing no significant quench at the concentrat-ions of interest in habitual measurements. (Author)

  11. Effect of three Electron Shuttles on Bioreduction of Ferric Iron in two Acidic and Calcareous soils

    Directory of Open Access Journals (Sweden)

    Setareh Sharifi

    2017-01-01

    Full Text Available Introduction: Iron cycle is one of the most important biogeochemical processes which affect the availability of iron in soils. Ferric iron oxides are the most abundant forms of iron in soils and sediments. Ferric iron is highly insoluble at circumneutral pH. Present investigations have shown that the structural ferric iron bound in clay minerals is reduced by some microorganisms. Anaerobic bacteria reduce ferric iron which bound to soil clay minerals under anaerobic conditions. They have the ability to use ferric iron as a terminal electron acceptor. Many studies presented that dissimilatory iron reducing bacteria (DIRB mediate the transfer of electrons from small organic molecules like acetate and glucose to various humic materials (electron shuttles which then pass electrons abiotically to ferric iron oxyhydroxide and phyllosilicate minerals. Electron shuttles like AQDS, a tricyclic quinone, increase the rate of iron reduction by iron reducing bacteria on sites of iron oxides and oxyhydroxides. By increasing the rate of bioreduction of ferric iron, the solubility and availability of iron enhanced meaningfully. Royer et al. (2002 showed that bioreduction of hematite (common iron mineral in soils increased more than three times in the presence of AQDS and Shewanella putrefaciens comparedto control treatments. Previous works have mostly used synthetic minerals as electron acceptor in bioreduction process. Furthermore, the effect of quinones as electron acceptor for microorganisms were studied with poorly crystalline ferric iron oxides . The main objective of this study was to study the effect of AQS, humic acid and fulvic acid (as electron shuttle and Shewanella sp. and Pseudomonas aeruginosa, on bioreduction of native ferric iron in two acidic and calcareous soils. Materials and Methods: An experiment was conducted in a completely randomized design with factorial arrangement and three replications in vitro condition. The soil samples collected

  12. Pitting corrosion resistance of high alloy OCTG in ferric chloride solution

    International Nuclear Information System (INIS)

    Masamura, K.; Yamamoto, S.; Matsushima, I.

    1986-01-01

    The effects of alloying elements and precipitated phases on the corrosion rate of high alloy OCTG in the ferric chloride solution have been evaluated. The corrosion rate of Fe-Cr-Ni-Mo alloys without precipitated phases, e.g. carbides and sigma phase, can be estimated from the composition using the following equation: log(C.R.)=-0.144xPRE-7690/(273+T)+28.6 where C.R. is the corrosion rate in g/m/sup 2//hr; PRE is Cr+3Mo+16N in percent and T is the test temperature in 0 C. The activation energies of the ferric chloride test are almost the same regardless of PRE or Ni content when no detrimental phase precipitates. When carbides or the sigma phase precipitate, the corrosion rate is higher and the activation energy is lowered. This suggests that secondary phases give preferential sites for initiation of pitting corrosion

  13. Molecular and phenotypic characterization of transgenic soybean expressing the Arabidopsis ferric chelate reductase gene, FRO2.

    Science.gov (United States)

    Vasconcelos, Marta; Eckert, Helene; Arahana, Venancio; Graef, George; Grusak, Michael A; Clemente, Tom

    2006-10-01

    Soybean (Glycine max Merr.) production is reduced under iron-limiting calcareous soils throughout the upper Midwest regions of the US. Like other dicotyledonous plants, soybean responds to iron-limiting environments by induction of an active proton pump, a ferric iron reductase and an iron transporter. Here we demonstrate that heterologous expression of the Arabidopsis thaliana ferric chelate reductase gene, FRO2, in transgenic soybean significantly enhances Fe(+3) reduction in roots and leaves. Root ferric reductase activity was up to tenfold higher in transgenic plants and was not subjected to post-transcriptional regulation. In leaves, reductase activity was threefold higher in the transgenic plants when compared to control. The enhanced ferric reductase activity led to reduced chlorosis, increased chlorophyll concentration and a lessening in biomass loss in the transgenic events between Fe treatments as compared to control plants grown under hydroponics that mimicked Fe-sufficient and Fe-deficient soil environments. However, the data indicate that constitutive FRO2 expression under non-iron stress conditions may lead to a decrease in plant productivity as reflected by reduced biomass accumulation in the transgenic events under non-iron stress conditions. When grown at Fe(III)-EDDHA levels greater than 10 microM, iron concentration in the shoots of transgenic plants was significantly higher than control. The same observation was found in the roots in plants grown at iron levels higher than 32 microM Fe(III)-EDDHA. These results suggest that heterologous expression of an iron chelate reductase in soybean can provide a route to alleviate iron deficiency chlorosis.

  14. Isolation of Trichoderma harzianum (Rifai) growing on ferric hydroxide mud impregnated with gas oil

    Energy Technology Data Exchange (ETDEWEB)

    Gudin, C. (Lavera Refinery, France); Chater, K.W.A.

    1977-09-01

    In northern France, gas oil-impregnated ferric hydroxide mud was found to support fungal growth. The fungus was identified by the Commonwealth Mycological Institute, Kew, with whom a reference culture has been registered. Experiments indicated that its growth resulted from the biodegradation of the gas oil. It is believed that, in this unusual situation, contaminating hydrocarbons may be removed from the environment by microbial activity.

  15. FeII induced mineralogical transformations of ferric oxyhydroxides into magnetite of variable stoichiometry and morphology

    International Nuclear Information System (INIS)

    Usman, M.; Abdelmoula, M.; Hanna, K.

    2012-01-01

    The Mössbauer spectroscopy was used to monitor the mineralogical transformations of ferrihydrite (F), lepidocrocite (L) and goethite (G) into magnetite as a function of aging time. Ferric oxyhydroxides were reacted with soluble Fe II and OH – in stoichiometric amounts to form magnetite at an initial pH of ∼9.7. Observed transformation extent into magnetite followed the order: F>L>G with almost 30% of untransformed G after 1 month. The departure from stoichiometry, δ, of magnetite (Fe 3−δ O 4 ) generated from F (δ∼0.04) and L (δ∼0.05) was relatively low as compared to that in magnetite from G (δ∼0.08). The analysis by transmission electron microscopy and BET revealed that generated magnetite was also different in terms of morphology, particle size and surface area depending on the nature of initial ferric oxyhydroxide. This method of preparation is a possible way to form nano-sized magnetite. - Graphical abstract: Mössbauer spectrum of the early stage of magnetite formation formed from the interaction of adsorbed Fe II species with goethite. Highlights: ► Ferric oxides were reacted with hydroxylated Fe II to form magnetite. ► Magnetite formation was quantified as a function of aging time. ► Complete transformation of ferrihydrite and lepidocrocite was achieved. ► Almost 70% of initial goethite was transformed. ► Resulting magnetites have differences in stoichiometry and morphological properties.

  16. Graphene oxide/ferric hydroxide composites for efficient arsenate removal from drinking water

    International Nuclear Information System (INIS)

    Zhang Kai; Dwivedi, Vineet; Chi Chunyan; Wu Jishan

    2010-01-01

    A series of novel composites based on graphene oxide (GO) cross-linked with ferric hydroxide was developed for effective removal of arsenate from contaminated drinking water. GO, which was used as a supporting matrix here, was firstly treated with ferrous sulfate. Then, the ferrous compound cross-linked with GO was in situ oxidized to ferric compound by hydrogen peroxide, followed by treating with ammonium hydroxide. The morphology and composition of the composites were analyzed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The ferric hydroxide was found to be homogenously impregnated onto GO sheets in amorphous form. These composites were evaluated as absorbents for arsenate removal from contaminated drinking water. For the water with arsenate concentration at 51.14 ppm, more than 95% of arsenate was absorbed by composite GO-Fe-5 with an absorption capacity of 23.78 mg arsenate/g of composite. Effective arsenate removal occurred in a wide range of pH from 4 to 9. However, the efficiency of arsenate removal was decreased when pH was increased to higher than 8.

  17. Comparison of Water Turbidity Removal Efficiencies of Descurainia Sophia Seed Extract and Ferric chloride

    Directory of Open Access Journals (Sweden)

    Mazyar Peyda

    2016-03-01

    Full Text Available Background Turbidity removal using inorganic coagulants such as iron and aluminum salts in water treatment processes causes environmental and human health concern. Historically, the use of natural coagulant to purify turbid water has been practiced for a long time. Recent research indicates that Descurainia Sophia seed can be effectively used as a natural coagulant to remove water turbidity. Method: In this work, turbidity removal efficiency of Descurainia Sophia seed extract was compared with Ferric chloride. Experiments were performed in laboratory scale. The coagulation experiments were done with kaolin as a model soil to produce turbidity in distilled water. The turbidity removal efficiency of Descurainia Sophia seed extract and Ferric chloride were conducted with jar test apparatus. In all experiments, initial turbidity was kept constant 100(NTU. Optimum combination of independent variables was used to compare two different types of coagulants. Result: The obtained results showed that Ferric chloride could remove 89.75% of the initial turbidity, while in case of Descurainia Sophia this value was 43.13%. The total organic carbon (TOC analysis of the treated water using seed extract showed an increased concentration of TOC equal to 0.99 mg/L. Conclusions: This research has shown that Descurainia Sophia seed extract has an acceptable potential in the coagulation/flocculation process to treat turbid water.

  18. Ferritin Elevation and Improved Responsiveness to Erythropoiesis-Stimulating Agents in Patients on Ferric Citrate Hydrate

    Directory of Open Access Journals (Sweden)

    Keitaro Yokoyama

    2017-05-01

    Discussion: It is suggested that not only iron load but also the erythropoiesis-stimulating agent dose reduction may be involved in ferritin elevation during ferric citrate hydrate treatment, resulting in a decrease of erythropoietin resistance index.

  19. Experimental determination of the phase boundary between kornelite and pentahydrated ferric sulfate at 0.1MPa

    Science.gov (United States)

    Kong, W.G.; Wang, A.; Chou, I.-Ming

    2011-01-01

    Recent findings of various ferric sulfates on Mars emphasize the importance of understanding the fundamental properties of ferric sulfates at temperatures relevant to that of Martian surface. In this study, the phase boundary between kornelite (Fe2(SO4)3.7H2O) and pentahydrated ferric sulfate (Fe2(SO4)3.5H2O) was experimentally determined using the humidity-buffer technique together with gravimetric measurements and Raman spectroscopy at 0.1MPa in the 36-56??C temperature range. Through the thermodynamic analysis of our experimental data, the enthalpy change (-290.8??0.3kJ/mol) and the Gibbs free energy change (-238.82??0.02kJ/mol) for each water molecule of crystallization in the rehydration of pentahydrated ferric sulfate to kornelite were obtained. ?? 2011 Elsevier B.V.

  20. Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis.

    Science.gov (United States)

    Jalal, Diana; McFadden, Molly; Dwyer, Jamie P; Umanath, Kausik; Aguilar, Erwin; Yagil, Yoram; Greco, Barbara; Sika, Mohammed; Lewis, Julia B; Greene, Tom; Goral, Simin

    2017-04-01

    Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown. We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed. There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group. Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence. © 2016 International Society for Hemodialysis.

  1. Reduction of costs for anemia-management drugs associated with the use of ferric citrate

    Directory of Open Access Journals (Sweden)

    Thomas A

    2014-05-01

    Full Text Available Anila Thomas,1 Leif E Peterson2 1Clinical Pharmacy Services, Houston Methodist Hospital, Houston, TX, USA; 2Center for Biostatistics, Houston Methodist Research Institute, Houston, TX, USA Background: Ferric citrate is a novel phosphate binder which has the potential to reduce usage of erythropoietin-stimulating agents (ESAs and intravenous (IV iron used for anemia management during hemodialysis (HD among patients with end-stage renal disease (ESRD. Currently, the potential health care cost savings on a national scale due to the use of ferric citrate in ESRD are undetermined. Methods: Per-patient-per-year costs of ESAs (Epogen® and Aranesp® [Amgen Inc., CA, USA] and IV iron (Venofer® [American Regent, Inc., NY, USA] and Ferrlecit® [Sanofi US, Bridgewater, NJ, USA] were based on RED BOOK™ (Truven Health Analytics New York, NY, USA costs combined with the Centers for Medicare and Medicaid Services (CMS base rate and actual usage in 2011 for the four drugs. The annual number of outpatients undergoing HD in the US was based on frequencies reported by the USRDS (United States Renal Data System. Monte Carlo uncertainty analysis was performed to determine total annual costs and cost reduction based on ferric citrate usage. Results: Total annual cost of ESAs and IV iron for anemia management in ESRD determined by Monte Carlo analysis assuming CMS base rate value was 5.127 (3.664–6.260 billion USD. For actual utilization in 2011, total annual cost of ESAs and IV iron was 3.981 (2.780–4.930 billion USD. If ferric citrate usage reduced ESA utilization by 20% and IV iron by 40%, then total cost would be reduced by 21.2% to 4.038 (2.868–4.914 billion USD for the CMS base rate, and by 21.8% to 3.111 (2.148–3.845 billion USD, based on 2011 actual utilization. Conclusion: It is likely that US health care costs for anemia-management drugs associated with ESRD among HD patients can be reduced by using ferric citrate as a phosphate binder. Keywords

  2. Ferric citrate.

    Science.gov (United States)

    Cada, Dennis J; Cong, Jasen; Baker, Danial E

    2015-02-01

    Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The February 2015 monograph topics are netupitant/palonosetron, naltrxone SR/bupropion SR, nintedanib, pirfenidone, and ivabradine. The Safety MUE is on netupitant/palonosetron.

  3. Safety and Efficacy of Intravenous Ferric Carboxy Maltose in Iron Deficiency Anaemia During Post-partum Period.

    Science.gov (United States)

    Mishra, Vineet; Roy, Priyankar; Gandhi, Khushali; Choudhary, Sumesh; Aggarwal, Rohina; Sokabaj, Shaheen

    2018-01-01

    Iron deficiency is the commonest treatable cause of postpartum anaemia. Parenteral iron therapy results in faster and higher replenishment of iron stores and correction of haemoglobin levels with better compliance. Ferric Carboxy Maltose is an effective and a safe option which can be administered intravenously in single total correction dose without any serious adverse effects.The study was done to evaluate the efficacy and safety of Ferric Carboxy Maltose in the treatment of iron deficiency anaemia in post-natal patients. It was an open, single arm study including 615 women with diagnosis of Iron deficiency anaemia and haemoglobin (Hb) levels between 4gm% and 11gm% from January 2013 to December 2016. Intravenous Ferric Carboxy Maltose(500-1500mg) was administered and the improvement in haemoglobin levels and iron stores were assessed after three weeks of total dose infusion. Out of the 615 women, 595 women were included in the analysis. Most of the women were in the age group of 27-30 years. Most of the women had mild anaemia as per World Health Organisation guidelines. Mean hemoglobin levels significantly increased over a period of three weeks after Ferric Carboxy Maltose administration. Other parameters like total iron binding capacity, Ferritin and Iron also had a significant improvement after Ferric Carboxy Maltose administration. No serious adverse events were observed after Ferric Carboxy Maltose. Intravenous Ferric Carboxy Maltose was an effective and a safe treatment option for iron deficiency anaemia and has an advantage of single administration of high doses without serious adverse effects.

  4. A Cost-effectiveness Analysis of Ferric Carboxymaltose in Patients With Iron Deficiency and Chronic Heart Failure in Spain.

    Science.gov (United States)

    Comín-Colet, Josep; Rubio-Rodríguez, Darío; Rubio-Terrés, Carlos; Enjuanes-Grau, Cristina; Gutzwiller, Florian S; Anker, Stefan D; Ponikowski, Piotr

    2015-10-01

    Treatment with ferric carboxymaltose improves symptoms, functional capacity, and quality of life in patients with chronic heart failure and iron deficiency. The aim of this study was to assess the cost-effectiveness of ferric carboxymaltose treatment vs no treatment in these patients. We used an economic model based on the Spanish National Health System, with a time horizon of 24 weeks. Patient characteristics and ferric carboxymaltose effectiveness (quality-adjusted life years) were taken from the Ferinject® Assessment in patients with IRon deficiency and chronic Heart Failure trial. Health care resource use and unit costs were taken either from Spanish sources, or from the above mentioned trial. In the base case analysis, patients treated with and without ferric carboxymaltose treatment acquired 0.335 and 0.298 quality-adjusted life years, respectively, representing a gain of 0.037 quality-adjusted life years for each treated patient. The cost per patient was €824.17 and €597.59, respectively, resulting in an additional cost of €226.58 for each treated patient. The cost of gaining 1 quality adjusted life year with ferric carboxymaltose was €6123.78. Sensitivity analyses confirmed the robustness of the model. The probability of ferric carboxymaltose being cost-effective (< €30 000 per quality-adjusted life year) and dominant (more effective and lower cost than no treatment) was 93.0% and 6.6%, respectively. Treatment with ferric carboxymaltose in patients with chronic heart failure and iron deficiency, with or without anemia, is cost-effective in Spain. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars

    Science.gov (United States)

    Sklute, Elizabeth C.; Rogers, A. Deanne; Gregerson, Jason C.; Jensen, Heidi B.; Reeder, Richard J.; Dyar, M. Darby

    2018-01-01

    Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca–, Na–, Mg– and Fe–chloride brines and multi-component (Fe2 (SO4)3 ± Ca, Na, Mg, Fe, Cl, HCO3) brines at ∼21°C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe–chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and

  6. Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars

    Science.gov (United States)

    Sklute, Elizabeth C.; Rogers, A. Deanne; Gregerson, Jason C.; Jensen, Heidi B.; Reeder, Richard J.; Dyar, M. Darby

    2018-03-01

    Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca-, Na-, Mg- and Fe-chloride brines and multicomponent (Fe2(SO4)3 ± Ca, Na, Mg, Fe, Cl, HCO3) brines at ∼21 °C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe-chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and transformation

  7. Ferric Iron Reduction by Bacteria Associated with the Roots of Freshwater and Marine Macrophytes†

    Science.gov (United States)

    King, G. M.; Garey, Meredith A.

    1999-01-01

    In vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of >100 μmol g (dry weight)−1 day−1 for three freshwater macrophytes and rates between 15 and 83 μmol (dry weight)−1 day−1 for two marine species. The rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). Sodium molybdate added at final concentrations of 0.2 to 20 mM did not inhibit iron reduction by roots of marine macrophytes (Spartina alterniflora and Zostera marina). Roots of a freshwater macrophyte, Sparganium eurycarpum, that were incubated with an analog of humic acid precursors, anthroquinone disulfate (AQDS), reduced freshly precipitated iron oxyhydroxide contained in dialysis bags that excluded solutes with molecular weights of >1,000; no reduction occurred in the absence of AQDS. Bacterial enrichment cultures and isolates from freshwater and marine roots used a variety of carbon and energy sources (e.g., acetate, ethanol, succinate, toluene, and yeast extract) and ferric oxyhydroxide, ferric citrate, uranate, and AQDS as terminal electron acceptors. The temperature optima for a freshwater isolate and a marine isolate were equivalent (approximately 32°C). However, iron reduction by the freshwater isolate decreased with increasing salinity, while reduction by the marine isolate displayed a relatively broad optimum salinity between 20 and 35 ppt. Our results suggest that by participating in an active iron cycle and perhaps by reducing humic acids, iron reducers in the rhizoplane of aquatic macrophytes limit organic availability to other heterotrophs (including methanogens) in the rhizosphere and bulk sediments. PMID:10508065

  8. Amorphous salts formed from rapid dehydration of multicomponent chloride and ferric sulfate brines: Implications for Mars.

    Science.gov (United States)

    Sklute, Elizabeth C; Rogers, A Deanne; Gregerson, Jason C; Jensen, Heidi B; Reeder, Richard J; Dyar, M Darby

    2018-03-01

    Salts with high hydration states have the potential to maintain high levels of relative humidity (RH) in the near subsurface of Mars, even at moderate temperatures. These conditions could promote deliquescence of lower hydrates of ferric sulfate, chlorides, and other salts. Previous work on deliquesced ferric sulfates has shown that when these materials undergo rapid dehydration, such as that which would occur upon exposure to present day Martian surface conditions, an amorphous phase forms. However, the fate of deliquesced halides or mixed ferric sulfate-bearing brines are presently unknown. Here we present results of rapid dehydration experiments on Ca-, Na-, Mg- and Fe-chloride brines and multi-component (Fe 2 (SO 4 ) 3 ± Ca, Na, Mg, Fe, Cl, HCO 3 ) brines at ∼21°C, and characterize the dehydration products using visible/near-infrared (VNIR) reflectance spectroscopy, mid-infrared attenuated total reflectance spectroscopy, and X-ray diffraction (XRD) analysis. We find that rapid dehydration of many multicomponent brines can form amorphous solids or solids with an amorphous component, and that the presence of other elements affects the persistence of the amorphous phase under RH fluctuations. Of the pure chloride brines, only Fe-chloride formed an amorphous solid. XRD patterns of the multicomponent amorphous salts show changes in position, shape, and magnitude of the characteristic diffuse scattering observed in all amorphous materials that could be used to help constrain the composition of the amorphous salt. Amorphous salts deliquesce at lower RH values compared to their crystalline counterparts, opening up the possibility of their role in potential deliquescence-related geologic phenomena such as recurring slope lineae (RSLs) or soil induration. This work suggests that a wide range of aqueous mixed salt solutions can lead to the formation of amorphous salts and are possible for Mars; detailed studies of the formation mechanisms, stability and transformation

  9. Effects of lead mineralogy on soil washing enhanced by ferric salts as extracting and oxidizing agents.

    Science.gov (United States)

    Yoo, Jong-Chan; Park, Sang-Min; Yoon, Geun-Seok; Tsang, Daniel C W; Baek, Kitae

    2017-10-01

    In this study, we evaluated the feasibility of using ferric salts including FeCl 3 and Fe(NO 3 ) 3 as extracting and oxidizing agents for a soil washing process to remediate Pb-contaminated soils. We treated various Pb minerals including PbO, PbCO 3 , Pb 3 (CO 3 ) 2 (OH) 2 , PbSO 4 , PbS, and Pb 5 (PO 4 ) 3 (OH) using ferric salts, and compared our results with those obtained using common washing agents of HCl, HNO 3 , disodium-ethylenediaminetetra-acetic acid (Na 2 -EDTA), and citric acid. The use of 50 mM Fe(NO 3 ) 3 extracted significantly more Pb (above 96% extraction) from Pb minerals except PbSO 4 (below 55% extraction) compared to the other washing agents. In contrast, washing processes using FeCl 3 and HCl were not effective for extraction from Pb minerals because of PbCl 2 precipitation. Yet, the newly formed PbCl 2 could be dissolved by subsequent wash with distilled water under acidic conditions. When applying our washing method to remediate field-contaminated soil from a shooting range that had high concentrations of Pb 3 (CO 3 ) 2 (OH) 2 and PbCO 3 , we extracted more Pb (approximately 99% extraction) from the soil using 100 mM Fe(NO 3 ) 3 than other washing agents at the same process conditions. Our results show that ferric salts can be alternative washing agents for Pb-contaminated soils in view of their extracting and oxidizing abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Ferric ammonium citrate as a positive bowel contrast agent for MR imaging of the upper abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Kivelitz, D.; Taupitz, M.; Hamm, B. [Universitaetsklinikum Charite, Berlin (Germany). Inst. fuer Radiologie; Gehl, H.B. [Medizinische Univ. Luebeck (Germany). Inst. fuer Radiologie; Heuck, A. [Muenchen Univ. (Germany). Radiologische Klinik; Krahe, T. [Koeln Univ. (Germany). Inst. fuer Radiologische Diagnostik; Lodemann, K.P. [Bracco-Byk Gulden GmbH, Konstanz (Germany)

    1999-07-01

    Purpose: To evaluate the safety and diagnostic efficacy of two different doses of ferric ammonium citrate as a paramagnetic oral contrast agent for MR imaging of the upper abdomen. Material and methods: Ninety-nine adult patients referred for MR imaging for a known or suspected upper abdominal pathology were included in this randomized multicenter double-blind clinical trial. Imaging was performed with spin-echo (T1- and T2-weighted) and gradient-echo (T1-weighted) techniques before and after administration of either 1200 mg or 2400 mg of ferric ammonium citrate dissolved in 600 ml of water. Safety analysis included monitoring of vital signs, assessment of adverse events, and laboratory testing. Efficacy with regard to organ distension, contrast distribution, bowel enhancement and delineation of adjacent structures was graded qualitatively. Results: No serious adverse events were reported for either of the two concentrations. A total of 31 minor side effects were noted, of which significantly more occurred in the higher dose group (p<0.01). The diagnostic confidence in defining or excluding disease was graded as better after contrast administration for 48% of all images. Marked or moderate enhancement of the upper gastrointestinal tract was achieved at both doses in 69.5% of cases with no evident difference between the two doses. The higher dose tended to show better results in terms of the contrast assessment parameters. Conclusion: Ferric ammonium citrate is a safe and effective oral contrast agent for MR imaging of the upper abdomen at two different dose levels. The higher dose showed a tendency toward better imaging results while the lower dose caused significantly fewer side effects. Therefore, the 1200 mg dose can be recommended in view of the risk-to-benefit ratio. (orig.)

  11. Ferric chloride modified zeolite in wastewater on Cr (VI) adsorption characteristics

    Science.gov (United States)

    Wu, Xiaoqing; Zhang, Kang; Chen, Wen; Zhang, Hua

    2018-03-01

    Zeolite was modified by ferric chloride(Fe-Z) removal Cr (VI) ion from wastewater. The results showed that the effect of Cr(VI) adsorption on modified zeolite depended significantly on pH. It is favorable for the adsorption of Cr(VI) in acid condition. The Langmuir isotherm model has high fitting accuracy with experimental data, demonstrated that is monolayer adsorption and chemical adsorption.The pseudo-second-order equation provided the best correlation to the data. The model can describe the adsorption reaction process well.

  12. Ferric chloride-graphite intercalation compounds as anode materials for Li-ion batteries.

    Science.gov (United States)

    Wang, Lili; Zhu, Yongchun; Guo, Cong; Zhu, Xiaobo; Liang, Jianwen; Qian, Yitai

    2014-01-01

    Ferric chloride-graphite intercalation compounds (FeCl3 -GICs) with stage 1 and stage 2 structures were synthesized by reacting FeCl3 and expanded graphite (EG) in air in a stainless-steel autoclave. As rechargeable Li-ion batteries, these FeCl3 -GICs exhibit high capacity, excellent cycling stability, and superior rate capability, which could be attributed to their unique intercalation features. This work may enable new possibilities for the fabrication of Li-ion batteries. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. FPGA-based quench detection system for super-FRS super-ferric dipole prototype

    International Nuclear Information System (INIS)

    Yang Tongjun; Wu Wei; Yao Qinggao; Yuan Ping; He Yuan; Han Shaofei; Ma Lizhen

    2011-01-01

    The quench detection system for Super-FRS super-ferric dipole prototype magnet of FAIR has been designed and built. The balance bridge was used to detect quench signal. In order to avoid blind zone of quench detection, two independent bridges were used. NI PXI-7830R FPGA was used to implement filter to quench signal and algorithm of quench decision and to produce quench trigger signal. Pre-sample technique was used in quench data acquisition. The data before and after quench could be recorded for analysis later. The test result indicated that the quench of the dipole's superconducting coil could be reliably detected by the quench detection module. (authors)

  14. [Topography structure and flocculation mechanism of polymeric phosphate ferric sulfate (PPFS)].

    Science.gov (United States)

    Zheng, Huai-li; Zhang, Hui-qin; Jiang, Shao-jie; Li, Fang; Jiao, Shi-jun; Fang, Hui-li

    2011-05-01

    Characteristics of polymeric phosphate ferric sulfate (PPFS) were investigated using FTIR (Fourier transform infrared spectrometer), XRD (X-ray diffraction) and SEM (scanning electron microscope) in the present study. The formed PPFS structure and morphology were stereo meshwork, which was clustered and close to coral reef, synthesis of high charge density, bioactive polyhydroxy and mixed polynuclear complex PPFS. The results showed that charge neutralization of PPFS had not played a decisive role in the coagulation beaker test and the zeta potential proved that PPFS was largely affected by bridging and netting sweep. Therefore, the coagulation mechanisms of PPFS were mainly composed of charge neutralization, adsorption bridging and netting sweep mechanisms.

  15. Improvement of Sodium Leaching Ratio of Ferric Bauxite Sinter after Direct Reduction

    Directory of Open Access Journals (Sweden)

    Wentao Hu

    2017-01-01

    Full Text Available The sodium leaching ratio (ηN of ferric bauxite direct reduction process is much lower than that of ordinary bauxite; thus, the former consumes more sodium than the latter. ηN can be promoted by increasing the dosage of sodium or restricted by increasing the heating temperature and time. However, the restriction effect of heating temperature is 16.67 times larger than that of heating time, and the restriction effect decreases 47.03 times faster when heating temperature increases than that process of heating time. These imply that ηN improves with the increasing sodium carbonate dosage and the decreasing heating temperature.

  16. A case of osteomalacia due to deranged mineral balance caused by saccharated ferric oxide and short-bowel syndrome

    Science.gov (United States)

    Nomoto, Hiroshi; Miyoshi, Hideaki; Nakamura, Akinobu; Nagai, So; Kitao, Naoyuki; Shimizu, Chikara; Atsumi, Tatsuya

    2017-01-01

    Abstract Rationale: Saccharated ferric oxide has been shown to lead to elevation of fibroblast growth factor 23, hypophosphatemia, and, consequently, osteomalacia. Moreover, mineral imbalance is often observed in patients with short-bowel syndrome to some degree. Patient concerns: A 62-year-old woman with short-bowel syndrome related with multiple resections of small intestines due to Crohn disease received regular intravenous administration of saccharated ferric oxide. Over the course of treatment, she was diagnosed with tetany, which was attributed to hypocalcemia. Additional assessments of the patient revealed not only hypocalcemia, but also hypophosphatemia, hypomagnesemia, osteomalacia, and a high concentration of fibroblast growth factor 23 (314 pg/mL). Diagnoses: We diagnosed her with mineral imbalance-induced osteomalacia due to saccharated ferric oxide and short-bowel syndrome. Interventions: Magnesium replacement therapy and discontinuation of saccharated ferric oxide alone. Outcomes: These treatments were able to normalize her serum mineral levels and increase her bone mineral density. Lessons: This case suggests that adequate evaluation of serum minerals, including phosphate and magnesium, during saccharated ferric oxide administration may be necessary, especially in patients with short-bowel syndrome. PMID:28953654

  17. In Situ Structural Characterization of Ferric Iron Dimers in Aqueous Solutions

    DEFF Research Database (Denmark)

    Zhu, Mengqiang; Puls, Brendan W.; Frandsen, Cathrine

    2013-01-01

    The structure of ferric iron (Fe3+) dimers in aqueous solutions has long been debated. In this work, we have determined the dimer structure in situ in aqueous solutions using extended X-ray absorption fine structure (EXAFS) spectroscopy. An Fe K-edge EXAFS analysis of 0.2 M ferric nitrate solutions...... at pH 1.28–1.81 identified a Fe–Fe distance at ∼3.6 Å, strongly indicating that the dimers take the μ-oxo form. The EXAFS analysis also indicates two short Fe–O bonds at ∼1.80 Å and ten long Fe–O bonds at ∼2.08 Å, consistent with the μ-oxo dimer structure. The scattering from the Fe–Fe paths interferes...... confirmed by Mössbauer analyses of analogous quick frozen solutions. This work also explores the electronic structure and the relative stability of the μ-oxo dimer in a comparison to the dihydroxo dimer using density function theory (DFT) calculations. The identification of such dimers in aqueous solutions...

  18. Diffusion simulation of ferric ions in dosemeter Fricke-gel with variable diffusion coefficient

    International Nuclear Information System (INIS)

    Milani, Caio Jacob; Bevilacqua, Joyce da Silva; Rodrigues Junior, Orlando

    2014-01-01

    Dosimetry using dosimeters Fricke-xylenol-Gel (FXG) allows confirmation and better understanding of radiotherapy treatments. The technique involves the evaluation of volumes irradiated by magnetic resonance imaging (MRI) or CT-optical. In both cases, the time spent between the irradiation and measurement is an important factor that directly influences the results. The quality of the images can be compromised by the mobility of ferric ions (Fe 3+), formed during the interaction of radiation with matter, increasing the uncertainty in determining the isodose. In this work, we simulated the dynamic involving ferric ions formed in one irradiated region irradiated in a two-dimensional domain with a variable diffusion coefficient. This phenomenon is modeled by a differential equation and solved numerically by an efficient algorithm that generalizes the Crank-Nicolson method. The stability and consistency of the method guarantee the convergence of the numerical solution for a predefined tolerance based in the choice of discretization steps of time and space. Different continuous functions were chosen to represent the diffusion coefficient and graphical views of the phenomenon are presented for a better understanding of the process

  19. Ferrous and ferric ions-based high-throughput screening strategy for nitrile hydratase and amidase.

    Science.gov (United States)

    Lin, Zhi-Jian; Zheng, Ren-Chao; Lei, Li-Hua; Zheng, Yu-Guo; Shen, Yin-Chu

    2011-06-01

    Rapid and direct screening of nitrile-converting enzymes is of great importance in the development of industrial biocatalytic process for pharmaceuticals and fine chemicals. In this paper, a combination of ferrous and ferric ions was used to establish a novel colorimetric screening method for nitrile hydratase and amidase with α-amino nitriles and α-amino amides as substrates, respectively. Ferrous and ferric ions reacted sequentially with the cyanide dissociated spontaneously from α-amino nitrile solution, forming a characteristic deep blue precipitate. They were also sensitive to weak basicity due to the presence of amino amide, resulting in a yellow precipitate. When amino amide was further hydrolyzed to amino acid, it gave a light yellow solution. Mechanisms of color changes were further proposed. Using this method, two isolates with nitrile hydratase activity towards 2-amino-2,3-dimethyl butyronitrile, one strain capable of hydrating 2-amino-4-(hydroxymethyl phosphiny) butyronitrile and another microbe exhibiting amidase activity against 2-amino-4-methylsulfanyl butyrlamide were obtained from soil samples and culture collections of our laboratory. Versatility of this method enabled it the first direct and inexpensive high-throughput screening system for both nitrile hydratase and amidase. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Combining Ferric Salt and Cactus Mucilage for Arsenic Removal from Water.

    Science.gov (United States)

    Fox, Dawn I; Stebbins, Daniela M; Alcantar, Norma A

    2016-03-01

    New methods to remediate arsenic-contaminated water continue to be studied, particularly to fill the need for accessible methods that can significantly impact developing communities. A combination of cactus mucilage and ferric (Fe(III)) salt was investigated as a flocculation-coagulation system to remove arsenic (As) from water. As(V) solutions, ferric nitrate, and mucilage suspensions were mixed and left to stand for various periods of time. Visual and SEM observations confirmed the flocculation action of the mucilage as visible flocs formed and settled to the bottom of the tubes within 3 min. The colloidal suspensions without mucilage were stable for up to 1 week. Sample aliquots were tested for dissolved and total arsenic by ICP-MS and HGAFS. Mucilage treatment improved As removal (over Fe(III)-only treatment); the system removed 75-96% As in 30 min. At neutral pH, removal was dependent on Fe(III) and mucilage concentration and the age of the Fe(III) solution. The process is fast, achieving maximum removal in 30 min, with the majority of As removed in 10-15 min. Standard jar tests with 1000 μg/L As(III) showed that arsenic removal and settling rates were pH-dependent; As removal was between 52% (high pH) and 66% (low pH).

  1. Arsenic and antimony removal from drinking water by adsorption on granular ferric oxide.

    Science.gov (United States)

    Sazakli, Eleni; Zouvelou, Stavroula V; Kalavrouziotis, Ioannis; Leotsinidis, Michalis

    2015-01-01

    Arsenic and antimony occur in drinking water due to natural weathering or anthropogenic activities. There has been growing concern about their impact on health. The aim of this study was to assess the efficiency of a granular ferric oxide adsorbent medium to remove arsenic and antimony from drinking water via rapid small-scale column tests (RSSCTs). Three different water matrices - deionized, raw water treated with a reverse osmosis domestic device and raw water - were spiked with arsenic and/or antimony to a concentration of 100 μg L⁻¹. Both elements were successfully adsorbed onto the medium. The loadings until the guideline value was exceeded in the effluent were found to be 0.35-1.63 mg g⁻¹ for arsenic and 0.12-2.11 mg g⁻¹ for antimony, depending on the water matrix. Adsorption of one element was not substantially affected by the presence of the other. Aeration did not affect significantly the adsorption capacity. Granular ferric oxide could be employed for the simultaneous removal of arsenic and antimony from drinking water, whereas full-scale systems should be assessed via laboratory tests before their implementation.

  2. Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous

    International Nuclear Information System (INIS)

    Milani, Caio J.; Bevilacqua, Joyce da Silva; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L.

    2013-01-01

    Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe 3+ ), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe 3+ in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

  3. Novel regeneration method for phosphate loaded granular ferric (hydr)oxide--a contribution to phosphorus recycling.

    Science.gov (United States)

    Kunaschk, Marco; Schmalz, Viktor; Dietrich, Norman; Dittmar, Thomas; Worch, Eckhard

    2015-03-15

    At a progressive rate, small wastewater treatment plants in rural areas need to be equipped with an additional phosphorus removal stage in order to achieve a good chemical status in the receiving natural water bodies. A conventional regeneration method for ferric (hydr)oxides such as phosphate specific adsorbents, which can be applied to remove and recover phosphorus in fixed bed filters, was investigated and improved. It was shown that a loss of up to 85% of the initial capacity can be observed when regeneration with 1 M NaOH is implemented. The losses are caused by surface blocking with different calcium-containing compounds as revealed by an EDX analysis. These blocking compounds could be removed completely with an additional acidic regeneration step at pH = 2.5. During the alkaline desorption that followed, complete phosphorus removal and a full recovery of the adsorption capacity were achieved for goethite-rich Bayoxide(®) E 33 HC (E33HC) and akaganéite-rich GEH(®) 104 (GEH). The regeneration procedure was repeated up to eight times without any signs of further decline in the phosphate adsorption capacity or any changes in the specific surface area or pore size distribution of the adsorbent. In contrast to GEH and E33HC, ferric hydroxide- and calcite-rich FerroSorp(®) Plus (FSP) was partly dissolved during acid treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Treatment of rheumatoid synovitis of the knee with intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates

    International Nuclear Information System (INIS)

    Sledge, C.B.; Zuckerman, J.D.; Zalutsky, M.R.

    1986-01-01

    One hundred eight knees of 93 patients with seropositive rheumatoid arthritis and persistent synovitis of the knee were treated with an intraarticular injection of 270 mCi of dysprosium 165 bound to ferric hydroxide macroaggregate. Leakage of radioactivity from the injected joint was minimal. Mean leakage to the venous blood 3 hours after injection was 0.11% of the injected dose; this corresponds to a mean whole body dose of 0.2 rads. Mean leakage to the liver 24 hours after injection was 0.64% of the injected dose; this corresponds to a mean liver dose of 3.2 rads. In 7 additional patients examined, there was negligible or near negligible activity found in the draining inguinal lymph nodes. One-year followup was possible for 74 knees (63 patients). Sixty-one percent of the knees had good results, 23% had fair results, and 16% had poor results. There was a direct correlation between the radiographic stage and response to treatment. In knees with stage I radiographic changes, 72% showed good results; 93% showed improvement. In knees with stage II changes, 59% showed good results; 81% showed improvement. These preliminary results indicate that dysprosium 165-ferric hydroxide macroaggregate is an effective agent for radiation synovectomy. The low leakage rates observed offer a definite advantage over agents previously used

  5. Synovectomy of the rheumatoid knee using intra-articular injection of dysprosium-165-ferric hydroxide macroaggregates

    International Nuclear Information System (INIS)

    Sledge, C.B.; Zuckerman, J.D.; Shortkroff, S.; Zalutsky, M.R.; Venkatesan, P.; Snyder, M.A.; Barrett, W.P.

    1987-01-01

    One hundred and eleven patients who had seropositive rheumatoid arthritis and persistent synovitis of the knee were treated with intra-articular injection of 270 millicuries of dysprosium-165 bound to ferric hydroxide macroaggregates. A two-year follow-up was available for fifty-nine of the treated knees. Thirty-nine had a good result; nine, a fair result; and eleven, a poor result. Of the twenty-five knees that had Stage-I radiographic changes, nineteen had a good result. Of the thirty-four knees that had Stage-II radiographic changes, twenty showed a good result. Systemic spread of the radioactivity from the injected joint was minimum. The mean whole-body dose was calculated to be 0.3 rad and that to the liver twenty-four hours after injection, 3.2 rads. The results indicated that dysprosium-165-ferric hydroxide macroaggregate is an effective agent for performing radiation synovectomy, particularly in knees that have Stage-I radiographic changes. Because of the minimum rate of systemic spread of the dysprosium-165, it offers a definite advantage over agents that previously have been used

  6. Real-time monitoring of arsenic filtration by granular ferric hydroxide

    International Nuclear Information System (INIS)

    Fleming, D.E.B.; Eddy, I.S.; Gherase, M.R.; Gibbons, M.K.; Gagnon, G.A.

    2008-01-01

    Full text: Contamination of drinking water by arsenic is a serious public health issue in many parts of the world. One recent approach to this problem has been to filter out arsenic by use of granular ferric hydroxide (GFH), an adsorbent developed specifically for the selective removal of arsenic from water. Previous studies have documented the efficiency and high treatment capacity of this approach. We present a novel X-ray fluorescence method to monitor the accumulation of arsenic within a specially designed GFH column, as both a function of time (or water volume) and location along the column. Using a miniature X-ray tube and silicon PiN diode detector, X-ray fluorescence is used to detect characteristic X-rays of arsenic excited from within the GFH. Trials were performed using a water flow rate of approximately 1.5 litres per hour, with an added arsenic concentration of approximately 1000 μg per litre. In this paper, trial results are presented and potential applications described. Characteristic arsenic Kα X-ray peak area as a function of time, as measured at various locations along a granular ferric hydroxide (GFH) water filtration column

  7. Synthesis of waste cooking oil based biodiesel via ferric-manganese promoted molybdenum oxide / zirconia nanoparticle solid acid catalyst: influence of ferric and manganese dopants.

    Science.gov (United States)

    Alhassan, Fatah H; Rashid, Umer; Taufiq-Yap, Yun Hin

    2015-01-01

    The utilization of ferric-manganese promoted molybdenum oxide/zirconia (Fe-Mn- MoO3/ZrO2) (FMMZ) solid acid catalyst for production of biodiesel was demonstrated. FMMZ is produced through impregnation reaction followed by calcination at 600°C for 3 h. The characterization of FMMZ had been done using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), temperature programmed desorption of NH3 (TPD-NH3), transmission electron microscopy(TEM) and Brunner-Emmett-Teller (BET) surface area measurement. The effect of waste cooking oil methyl esters (WCOME's) yield on the reactions variables such as reaction temperature, catalyst loading, molar ratio of methanol/oil and reusability were also assessed. The catalyst was used to convert the waste cooking oil into corresponding methyl esters (95.6%±0.15) within 5 h at 200℃ reaction temperature, 600 rpm stirring speed, 1:25 molar ratio of oil to alcohol and 4% w/w catalyst loading. The reported catalyst was successfully recycled in six connective experiments without loss in activity. Moreover, the fuel properties of WCOME's were also reported using ASTM D 6751 methods.

  8. Implementation of ferric hydroxide-based media for removal of toxic metalloids

    Science.gov (United States)

    Szlachta, Małgorzata; Wójtowicz, Patryk

    2017-11-01

    Effective removal of inorganic arsenic species is possible by application of the sorption technique with the use of iron-based sorbents. This study investigates the removal of arsenic(III) and arsenic(V) from an aqueous solution by application of a granular ferric hydroxide-based sorbent. The performance of tested media was evaluated based on the batch and fixed-bed adsorption studies. The efficiency of the process was determined with various treatment times, adsorbent doses, initial concentrations of arsenic and various solution temperatures. The obtained adsorption data were fitted with pseudo-first and second-order kinetic models and Langmuir and Freundlich isotherm equations. It was observed that the overall arsenite removal was lower when compared to the arsenate, and all tested operating parameters influenced the process efficiency. The experiments under dynamic conditions showed high treatment capacity and stability of tested adsorbent over a long period of time.

  9. Characterization of sonicated natural zeolite/ferric chloride hexahydrate by infrared spectroscopy

    Science.gov (United States)

    Prasetyo, T. A. B.; Soegijono, B.

    2018-03-01

    The characteristics of sonicated Bayah natural zeolite with and without ferric chloride hexahydrate solution using infrared method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 min, 80 min and 120 min. Infra red spectra analysis was conducted to evaluate zeolite vibrational spectrum contributions, namely, the vibrations from the framework of the zeolite, from the charge-balancing cations, and from the relatively isolated groups, such as the surface OH groups and their behavior after sonication process. An addition of FeCl3.6H2O and sonication process on natural zeolite improved secondary building units link by forming oxygen bridges and also close relationship with duration of applied high intensity ultrasonic process. Longer ultrasonic process resulted in more increment of O-H absorbance.

  10. Segmentation of the potential consumers of ferric medicines based on data of iron deficiency anemia prevalence

    Directory of Open Access Journals (Sweden)

    Z. N. Mnushko

    2013-08-01

    Full Text Available INTRODUCTION. According to WHO 3.6 billion of people on the planet have latent iron deficiency and another 1.8 billion of people suffer from iron deficiency anemia (IDA. According to the Ministry of Health of Ukraine information the prevalence and the incidence of iron deficiency anemia is 1163.9 and 404.5 per 100 000 persons, respectively. However, this information is only clinically confirmed cases of IDA. The largest share in the structure of morbidity has the latent iron deficiency, which is characterized by less prominent clinical manifestations. Treatment of IDA aimed not only at addressing anemia as a symptom, but also at the elimination of iron deficiency and replenishment of its reserves in the organism, which can be achieved by taking ferric drugs. Today ferric drugs market is characterized by high leveled competition, stable demand and a wide range of products. Therefore, an important issue in the study of the market is to find the best ways to determining its potential capacity to expand the marketing potential and to provide iron supplementation as many consumers who need treatment and prevention of iron deficiency. GOAL OF THE STUDY. the segmentation of the population that needs treatment and prevention of iron deficiency on the basis of the etiological factors that cause development of anemia, based on official statistics on morbidity. MATERIALS AND METODS. According to the standard classification of the iron deficiency we have identified four main groups of etiological factors that lead to the development of IDA: bleeding, iron malabsorption, increased body's need for iron, as well as complicated genesis factors. In order to determine the total number of individual segments we have analyzed the reports of the State Statistics Committee of Ukraine, Health Statistics Centre of Ministry of Health of Ukraine, as well as electronic database of medical statistics “Health for All”. RESULTS AND DISCUSSION. According to the estimates

  11. Design, fabrication and cold tests of a super ferric octupole corrector for the LHC

    International Nuclear Information System (INIS)

    Garcia-Tabares, L.; Calero, J.; Laurent, G.; Russenschuck, S.; Siegel, N.; Traveria, M.; Aguirre, P.; Etxeandia, J.; Garcia, J.

    1996-01-01

    In the corrections scheme of the LHC it is planed to install octupole corrector magnets in the short straight section of the lattice. Initially these correctors were distributed windings on the cold bore tube nested in the tuning quadrupoles. The latter being suppressed a new compact super ferric design was chosen for the octupole prototype, suitable for a two-in-one configuration. This prototype was designed by CERN and CEDEX/Spain, built at INDAR/Spain and tested at CEDEX. The paper reports on the design of the prototype, describes the fabrication and assembly and presents the measurement results. Special interest has been taken to design a simple and compact magnet, easy to fabricate and training free below nominal field. First results show the feasibility of the solution wich will be finally confirmed by magnetic measurement. (Author) 4 refs

  12. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    International Nuclear Information System (INIS)

    Peng Zhang'e; Wu Feng; Deng Nansheng

    2006-01-01

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe 3+ ions was investigated. Algae, humic acid and Fe 3+ ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10 9 cells L -1 raw Chlorella vulgaris, 4 mg L -1 humic acid and 20 μmol L -1 Fe 3+ . The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment

  13. Photocatalytic Reduction of Hexavalent Chromium Induced by Photolysis of Ferric/tartrate Complex

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xianghua; Ding, Shimin; Zhang, Lixian [Yangtze Normal Univ., Fuling (China)

    2012-11-15

    Photocatalytic reduction of hexavalent chromium (Cr(VI)) in ferric-tartrate system under irradiation of visible light was investigated. Effects of light resources, initial pH value and initial concentration of various reactants on Cr(VI) photocatalytic reduction were studied. Photoreaction kinetics was discussed and a possible photochemical pathway was proposed. The results indicate that Fe(III)-tartrate system is able to rapidly and effectively photocatalytically reduce Cr(VI) utilizing visible light. Initial pH variations results in the concentration changes of Fe(III)-tartrate complex in this system, and pH at 3.0 is optimal for Cr(VI) photocatalytic reduction. Efficiency of Cr(VI) photocatalytic reduction increases with increasing initial concentrations of Cr(VI), Fe(III) and tartrate. Kinetics analysis indicates that initial Fe(III) concentration affects Cr(VI) photoreduction most significantly.

  14. Enhanced dark hydrogen fermentation by addition of ferric oxide nanoparticles using Enterobacter aerogenes.

    Science.gov (United States)

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Liu, Min; Zhou, Junhu; Cen, Kefa

    2016-05-01

    Ferric oxide nanoparticles (FONPs) were used to facilitate dark hydrogen fermentation using Enterobacter aerogenes. The hydrogen yield of glucose increased from 164.5±2.29 to 192.4±1.14mL/g when FONPs concentration increased from 0 to 200mg/L. SEM images of E. aerogenes demonstrated the existence of bacterial nanowire among cells, suggesting FONPs served as electron conduits to enhance electron transfer. TEM showed cellular internalization of FONPs, indicating hydrogenase synthesis and activity was potentially promoted due to the released iron element. When further increasing FONPs concentration to 400mg/L, the hydrogen yield of glucose decreased to 147.2±2.54mL/g. Soluble metabolic products revealed FONPs enhanced acetate pathway of hydrogen production, but weakened ethanol pathway. This shift of metabolic pathways allowed more nicotinamide adenine dinucleotide for reducing proton to hydrogen. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A high-throughput screening strategy for nitrile-hydrolyzing enzymes based on ferric hydroxamate spectrophotometry.

    Science.gov (United States)

    He, Yu-Cai; Ma, Cui-Luan; Xu, Jian-He; Zhou, Li

    2011-02-01

    Nitrile-hydrolyzing enzymes (nitrilase or nitrile hydratase/amidase) have been widely used in the pharmaceutical industry for the production of carboxylic acids and their derivatives, and it is important to build a method for screening for nitrile-hydrolyzing enzymes. In this paper, a simple, rapid, and high-throughput screening method based on the ferric hydroxamate spectrophotometry has been proposed. To validate the accuracy of this screening strategy, the nitrilases from Rhodococcus erythropolis CGMCC 1.2362 and Alcaligenes sp. ECU0401 were used for evaluating the method. As a result, the accuracy for assaying aliphatic and aromatic carboxylic acids was as high as the HPLC-based method. Therefore, the method may be potentially used in the selection of microorganisms or engineered proteins with nitrile-hydrolyzing enzymes.

  16. Differential scanning calorimetric study of HTPB based composite propellants in presence of nano ferric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Prajakta R.; Krishnamurthy, V.N.; Joshi, Satyawati S. [Department of Chemistry, University of Pune, Pune 411007 (India)

    2006-12-15

    A comparative study of the thermal decomposition of ammonium perchlorate (AP)/hydroxy terminated polybutadiene (HTPB) based composite propellants has been carried out in presence and absence of nano iron oxide at different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry. The pronounced effect was a lowering of the high temperature decomposition by 49 C. A higher heat release up to 40% was observed in presence of nano ferric oxide (3.5 nm). The kinetic parameters were evaluated using the Kissinger method. The increase of the rate constant in the catalyzed propellant confirmed the enhancement of the catalytic activity of ammonium perchlorate. The scanning electron micrographs of nano Fe{sub 2}O{sub 3} incorporated in HTPB revealed a well-separated characteristic necklace-like structure of {alpha}-Fe{sub 2}O{sub 3} particles at high magnification. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  17. The Porphyromonas gingivalis ferric uptake regulator orthologue does not regulate iron homeostasis

    Directory of Open Access Journals (Sweden)

    Catherine Butler

    2015-09-01

    Full Text Available Porphyromonas gingivalis is a Gram-negative anaerobic bacterium that has an absolute requirement for iron which it transports from the host as heme and/or Fe2+. Iron transport must be regulated to prevent toxic effects from excess metal in the cell. P. gingivalis has one ferric uptake regulator (Fur orthologue encoded in its genome called Har, which would be expected to regulate the transport and usage of iron within this bacterium. As a gene regulator, inactivation of Har should result in changes in gene expression of several genes compared to the wild-type. This dataset (GEO accession number GSE37099 provides information on expression levels of genes in P. gingivalis in the absence of Har. Surprisingly, these genes do not relate to iron homeostasis.

  18. Photocatalytic Reduction of Hexavalent Chromium Induced by Photolysis of Ferric/tartrate Complex

    International Nuclear Information System (INIS)

    Feng, Xianghua; Ding, Shimin; Zhang, Lixian

    2012-01-01

    Photocatalytic reduction of hexavalent chromium (Cr(VI)) in ferric-tartrate system under irradiation of visible light was investigated. Effects of light resources, initial pH value and initial concentration of various reactants on Cr(VI) photocatalytic reduction were studied. Photoreaction kinetics was discussed and a possible photochemical pathway was proposed. The results indicate that Fe(III)-tartrate system is able to rapidly and effectively photocatalytically reduce Cr(VI) utilizing visible light. Initial pH variations results in the concentration changes of Fe(III)-tartrate complex in this system, and pH at 3.0 is optimal for Cr(VI) photocatalytic reduction. Efficiency of Cr(VI) photocatalytic reduction increases with increasing initial concentrations of Cr(VI), Fe(III) and tartrate. Kinetics analysis indicates that initial Fe(III) concentration affects Cr(VI) photoreduction most significantly

  19. Safety of intravenous ferric carboxymaltose versus oral iron in patients with nondialysis-dependent CKD

    DEFF Research Database (Denmark)

    Roger, Simon D; Gaillard, Carlo A; Bock, Andreas H

    2017-01-01

    -label, multicenter, prospective study of patients with nondialysis-dependent CKD, anemia and iron deficiency randomized (1:1:2) to IV ferric carboxymaltose (FCM), targeting higher (400-600 µg/L) or lower (100-200 µg/L) ferritin, or oral iron. A post hoc analysis of adverse event rates per 100 patient......: These results further support the conclusion that correction of iron deficiency anemia with IV FCM is safe in patients with nondialysis-dependent CKD.......Background: The evidence base regarding the safety of intravenous (IV) iron therapy in patients with chronic kidney disease (CKD) is incomplete and largely based on small studies of relatively short duration. Methods: FIND-CKD (ClinicalTrials.gov number NCT00994318) was a 1-year, open...

  20. Renal function in patients with non-dialysis chronic kidney disease receiving intravenous ferric carboxymaltose

    DEFF Research Database (Denmark)

    Macdougall, Iain C; Bock, Andreas H; Carrera, Fernando

    2017-01-01

    BACKGROUND: Preclinical studies demonstrate renal proximal tubular injury after administration of some intravenous iron preparations but clinical data on renal effects of intravenous iron are sparse. METHODS: FIND-CKD was a 56-week, randomized, open-label, multicenter study in which patients...... with non-dialysis dependent chronic kidney disease (ND-CKD), anemia and iron deficiency without erythropoiesis-stimulating agent therapy received intravenous ferric carboxymaltose (FCM), targeting either higher (400-600 μg/L) or lower (100-200 μg/L) ferritin values, or oral iron. RESULTS: Mean (SD) e...... quartiles of FCM dose, change in ferritin or change in TSAT versus change in eGFR. Dialysis initiation was similar between groups. Renal adverse events were rare, with no indication of between-group differences. CONCLUSION: Intravenous FCM at doses that maintained ferritin levels of 100-200 μg/L or 400...

  1. Optical and electrical properties of thin films of bismuth ferric oxide

    International Nuclear Information System (INIS)

    Cardona R, D.

    2014-01-01

    The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe 2 O 3 ) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO 3 in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO 3 composition. These samples showed a secondary phase (Bi 2 5FeO 4 0 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe 2 O 3 ) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

  2. Study of the Efficiency of Arsenic Removal from Drinking Water by Granular Ferric Hydroxide (GFH

    Directory of Open Access Journals (Sweden)

    .R. Asgari

    2008-04-01

    Full Text Available Background and ObjectivePollution of surface and ground water to arsenic (As has been reported from many parts of the world and in some regions of Iran especially in Kurdistan province. Natural pollution of water to As is in fact dependent to geological characteristics of a region. To day, various methods have been recommended for As removal that each of which has special advantages and drawbacks. Granular ferric hydroxide (GFH is a relatively new adsorbent available in market which is principally introduced for As removal.MethodsThis study was an applied survey in which the effects of changing contact time, As concentration, adsorbent weight, pH as well as the effect of sulfate and chloride ions in arsenic removal were determined. Moreover, the model of absorption by GFH was studied and compared with Freundlich and Langmuir models. Raw data were analyzed by Excel and SPSS softwares. ResultsResults showed that As adsorption by GFH imitate both the Freundlich and Langmuir equations (with R2 >0.95. Optimum PH was 7.5 and duration of the process about 30 minutes was sufficient for optimum removal of As. It was also found that efficiency of As removal was high when small amounts of adsorbent were used. Furthermore, sulfate and chloride ions in concentrations used in this study had no noticeable effect on As removal and Fe added during process remains in the water more than the standard value (0.3 mg/l.ConclusionAccording to this study, GFH could be considered as a suitable adsorbent for As removal from polluted water resources because of its high performance without any needs to PH adjustment. However, there are few drawbacks such as Fe addition and relatively high initial cost. Keywords: Arsenic, Granular Ferric Hydroxide (GFH, Adsorption, Drinking Water

  3. Hydrous Ferric Oxides in Sediment Catalyze Formation of Reactive Oxygen Species during Sulfide Oxidation

    Directory of Open Access Journals (Sweden)

    Sarah A. Murphy

    2016-11-01

    Full Text Available Abstract: This article describes the formation of reactive oxygen species as a result of the oxidation of dissolved sulfide by Fe(III-containing sediments suspended in oxygenated seawater over the pH range 7.00 and 8.25. Sediment samples were obtained from across the coastal littoral zone in South Carolina, US, at locations from the beach edge to the forested edge of a Spartina dominated estuarine salt marsh and suspended in aerated seawater. Reactive oxygen species (superoxide and hydrogen peroxide production was initiated in sediment suspensions by the addition of sodium bisulfide. The subsequent loss of HS-, formation of Fe(II (as indicated by Ferrozine, and superoxide and hydrogen peroxide were monitored over time. The concentration of superoxide rose from the baseline and then persisted at an apparent steady state concentration of approximately 500 nanomolar at pH 8.25 and 200 nanomolar at pH 7.00 respectively until >97% hydrogen sulfide was consumed. Measured superoxide was used to predict hydrogen peroxide yield based on superoxide dismutation. Dismutation alone quantitatively predicted hydrogen peroxide formation at pH 8.25 but over predicted hydrogen peroxide formation at pH 7 by a factor of approximately 102. Experiments conducted with episodic spikes of added hydrogen peroxide indicated rapid hydrogen peroxide consumption could account for its apparent low instantaneous yield, presumably the result of its reaction with Fe(II species, polysulfides or bisulfite. All sediment samples were characterized for total Fe, Cu, Mn, Ni, Co and hydrous ferric oxide by acid extraction followed by mass spectrometric or spectroscopic characterization. Sediments with the highest loadings of hydrous ferric oxide were the only sediments that produced significant dissolved Fe(II species or ROS as a result of sulfide exposure.

  4. A study on the alkali leaching of complex compound for molybdenum trioxide and ferric oxide

    International Nuclear Information System (INIS)

    Kim, C.G.; Whang, Y.K.

    1981-01-01

    This study is to determine the alkali-leaching meachanism by which complex compound by the reaction made between molybdenite (MoS 2 ) and ferric oxide (Fe 2 O 3 ) in the roasted are when molybdenum trioxide (MoO 3 ) is formed by the roasting reaction of molybdenite concentrate. The results obtained from this experiment are summarized as follows: The heating reaction analysis shows that the complex compound of iron molybdates (Fe 2 O 3 .3-4 MoO 3 ) is formed by the reaction of molybdenum trioxide and ferric oxide at temperatures of above 500 0 C. It is shown that at various reaction temperature below 400 0 C molybdenum trioxide is almost completely leached by caustic soda irrespective of the mole ratio of two chemical samples used for the experiment, whereas at temperature above 400 0 C the leaching rate of molybdenum trioxide decreases except that it varies from 70.77% at a temperature of 900 0 C at which the mole ratio is 1 to 1 to 84.08% at a temperature of 1000 0 C. The x-ray diffraction analysis has shown that the complex compound reacted at a temperature of 1000 0 C produces a complex compound with the crystal structure of iron molybdates, and the alkali-leached residues even with 19.0% of molybdenum trioxide, however, contain only α-Fe 2 O 3 , without showing iron molybdates. The crystalline compound of iron molybdates obtained as a result of heating reaction was leached by using caustic soda, while MoO 3 and Fe 2 O 3 in the leaching residue was found to contain other compounds unable to be leached by caustic soda. (author)

  5. Phylogenetic diversity of dissimilatory ferric iron reducers in paddy soil of Hunan, South China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xin-Jun [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Graduate Univ., Chinese Academy of Sciences, BJ (China); Yang Jing; Chen Xue-Ping; Sun Guo-Xin [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Zhu Yong-Guan [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Key Lab. of Urban Environment and Health, Inst. of Urban Environment, Chinese Academy of Sciences, Xiamen (China)

    2009-12-15

    Purpose: Dissimilatory iron-reducing bacteria have been described by both culture-dependent and -independent methods in various environments, including freshwater, marine sediments, natural wetlands, and contaminated aquifers. However, little is known about iron-reducing microbial communities in paddy soils. The goal of this study was to characterize iron-reducing microbial communities in paddy soil. Moreover, the effect of dissolved and solid-phase iron (III) species on the iron-reducing microbial communities was also investigated by enrichment cultures. Methods: Ferric citrate and ferrihydrite were used respectively to set up enrichment cultures of dissimilatory ironreducing microorganisms using 1% inoculum of soil samples, and the iron reduction was measured. Moreover, bacterial DNA was extracted and 16S rRNA genes were PCR-amplified, and subsequently analyzed by the clone library and terminal restriction fragment length polymorphism (T-RFLP). Results: Phylogenetic analysis of 16S rRNA gene sequences extracted from the enrichment cultures revealed that Bradyrhizobium, Bacteroides, Clostridium and Ralstonia species were the dominant bacteria in the ferric citrate enrichment. However, members of the genera Clostridium, Bacteroides, and Geobacter were the dominant micro-organisms in the ferrihydrite enrichment. Analysis of enrichment cultures by T-RFLP strongly supported the cloning and sequencing results. Conclusions: The present study demonstrated that dissimilatory iron-reducing consortia in As-contaminated paddy soil are phylogenetically diverse. Moreover, iron (III) sources as a key factor have a strong effect on the iron (III)-reducing microbial community structure and relative abundance in the enrichments. In addition, Geobacter species are selectively enriched by ferrihydrite enrichment cultures. (orig.)

  6. Structural characterization of ferric hemoglobins from three antarctic fish species of the suborder notothenioidei.

    Science.gov (United States)

    Vergara, Alessandro; Franzese, Marisa; Merlino, Antonello; Vitagliano, Luigi; Verde, Cinzia; di Prisco, Guido; Lee, H Caroline; Peisach, Jack; Mazzarella, Lelio

    2007-10-15

    Spontaneous autoxidation of tetrameric Hbs leads to the formation of Fe (III) forms, whose physiological role is not fully understood. Here we report structural characterization by EPR of the oxidized states of tetrameric Hbs isolated from the Antarctic fish species Trematomus bernacchii, Trematomus newnesi, and Gymnodraco acuticeps, as well as the x-ray crystal structure of oxidized Trematomus bernacchii Hb, redetermined at high resolution. The oxidation of these Hbs leads to formation of states that were not usually detected in previous analyses of tetrameric Hbs. In addition to the commonly found aquo-met and hydroxy-met species, EPR analyses show that two distinct hemichromes coexist at physiological pH, referred to as hemichromes I and II, respectively. Together with the high-resolution crystal structure (1.5 A) of T. bernacchii and a survey of data available for other heme proteins, hemichrome I was assigned by x-ray crystallography and by EPR as a bis-His complex with a distorted geometry, whereas hemichrome II is a less constrained (cytochrome b5-like) bis-His complex. In four of the five Antartic fish Hbs examined, hemichrome I is the major form. EPR shows that for HbCTn, the amount of hemichrome I is substantially reduced. In addition, the concomitant presence of a penta-coordinated high-spin Fe (III) species, to our knowledge never reported before for a wild-type tetrameric Hb, was detected. A molecular modeling investigation demonstrates that the presence of the bulkier Ile in position 67beta in HbCTn in place of Val as in the other four Hbs impairs the formation of hemichrome I, thus favoring the formation of the ferric penta-coordinated species. Altogether the data show that ferric states commonly associated with monomeric and dimeric Hbs are also found in tetrameric Hbs.

  7. Ion sorption onto hydrous ferric oxides: Effect on major element fluid chemistry at Aespoe, Sweden

    International Nuclear Information System (INIS)

    Bruton, C.J.; Viani, B.E.

    1996-06-01

    The observed variability of fluid chemistry at the Aespoe Hard Rock Laboratory is not fully described by conservative fluid mixing models. Ion exchange may account for some of the observed discrepancies. It is also possible that variably charged solids such as oxyhydroxides of Fe can serve as sources and sinks of anions and cations through surface complexation. Surface complexation reactions on hydrous ferric oxides involve sorption of both cations and anions. Geochemical modeling of the surface chemistry of hydrous ferric oxides (HFOs) in equilibrium with shallow HBH02 and deep KA0483A waters shows that HFOs can serve as significant, pH-sensitive sources and sinks for cations and anions. Carbonate sorption is favored especially at below-neutral pH. A greater mass of carbonate is sorbed onto HFO surfaces than is contained in the fluid when 10 g goethite, used as a proxy for HFOs, is in contact with 1 kg H 2 O. The masses of sorbent required to significantly impact fluid chemistry through sorption/desorption reactions seem to be reasonable when compared to the occurrences of HFOs at Aespoe. Thus, it is possible that small changes in fluid chemistry can cause significant releases of cations or anions from HFOs into the fluid phase or, alternately, result in uptake of aqueous species onto HFO surfaces. Simulations of the mixing of shallow HBH02 and native KA0483A waters in the presence of a fixed mass of goethite show that surface complexation does not cause the concentrations of Ca, Sr, and SO 4 to deviate from those that are predicted using conservative mixing models. Results for HCO 3 are more difficult to interpret and cannot be addressed adequately at this time

  8. Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

    Science.gov (United States)

    Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

    2016-01-01

    A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

  9. Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

    Science.gov (United States)

    Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

    2017-03-01

    The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water

    Directory of Open Access Journals (Sweden)

    Yali Song

    2015-06-01

    Full Text Available Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM as a pretreatment prior to polyvinylidene fluoride (PVDF microfiltration (MF membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW distributions of NOM in the tested surface raw water were concentrated at 3–5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3–5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2–30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling.

  11. Ferric reductase genes involved in high-affinity iron uptake are differentially regulated in yeast and hyphae of Candida albicans.

    Science.gov (United States)

    Jeeves, Rose E; Mason, Robert P; Woodacre, Alexandra; Cashmore, Annette M

    2011-09-01

    The pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron-restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form, which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked. It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also makes a significant contribution to cell surface ferric and cupric reductase activity. It is also shown, for the first time, that transcription of FRE10 and FRE7 is lower in hyphae compared to yeast and that this leads to a corresponding decrease in cell surface ferric, but not cupric, reductase activity. This demonstrates that the regulation of two virulence determinants, the reductive iron uptake system and the morphological form of C. albicans, are linked. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Pyrite formation and mineral transformation pathways upon sulfidation of ferric hydroxides depend on mineral type and sulfide concentration

    NARCIS (Netherlands)

    Peiffer, Stefan; Behrends, Thilo; Hellige, Katrin; Larese-Casanova, Philip; Wan, Moli; Pollok, Kilian

    2015-01-01

    The reaction of ferric (hydr)oxides with dissolved sulfide does not lead to the instantaneous production of thermodynamically stable products but can induce a variety of mineral transformations including the formation of metastable intermediates. The importance of the various transformation pathways

  13. An electron spin resonance study of bis(tetraphenylarsonium) pentakis(isothiocyanato)nitrosyltechnetate(II): a six-co-ordinate low-spin 4d5 technetium(II) complex

    International Nuclear Information System (INIS)

    Baldas, J.; Boas, J.F.; Bonnyman, J.; Williams, G.A.

    1984-01-01

    The e.s.r. spectrum of the title complex has been studied in non-aqueous solution in the liquid and frozen glass phases. The spectrum is characteristic of a low-spin 4d 5 technetium(II) ion in an axially symmetric environment: g and A values are reported. The small quadrupole interaction observed is solvent dependent. A simple crystal field model, in which the unpaired electron is located in the tsub(2g) orbital triplet, is able to explain most features of the e.s.r. spectrum. A consideration of the electronic parameters derived from the g and A values leads to the conclusion that the results are best explained by a large tetragonal distortion from octahedral symmetry with strong π bonding between technetium and the ligands. (author)

  14. Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes.

    Science.gov (United States)

    Hackl, Laura; Cercamondi, Colin I; Zeder, Christophe; Wild, Daniela; Adelmann, Horst; Zimmermann, Michael B; Moretti, Diego

    2016-05-01

    Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability. We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains. We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios. Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice. Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of FePP and CA/TSC in the extruded rice matrix. This trial was registered at

  15. Possible Association of Ferrous Phosphates and Ferric Sulfates in S-rich Soil on Mars

    Science.gov (United States)

    Mao, J.; Schroeder, C.; Haderlein, S.

    2012-12-01

    NASA Mars Exploration Rover (MER) Spirit explored Gusev Crater to look for signs of ancient aqueous activity, assess past environmental conditions and suitability for life. Spirit excavated light-toned, S-rich soils at several locations. These are likely of hydrothermal, possibly fumarolic origin. At a location dubbed Paso Robles the light-toned soil was also rich in P - a signature from surrounding rock. While S is mainly bound in ferric hydrated sulfates [1], the mineralogy of P is ill-constrained [2]. P is a key element for life and its mineralogy constrains its availability. Ferrous phases observed in Paso Robles Mössbauer spectra may represent olivine and pyroxene from surrounding basaltic soil [1] or ferrous phosphate minerals [3]. Phosphate is well-known to complex and stabilize Fe 2+ against oxidation to Fe 3+ . Schröder et al. [3] proposed a formation pathway of ferrous phosphate/ferric sulfate associations: sulfuric acid reacts with basalt containing apatite, forming CaSO4 and phosphoric acid. The phosphoric and/or excess sulfuric acid reacts with olivine, forming Fe2+-phosphate and sulfate. The phosphate is less soluble and precipitates. Ferrous sulfate remains in solution and is oxidized as pH increases. To verify this pathway, we dissolved Fe2+-chloride and Na-phosphate salts in sulfuric acid inside an anoxic glovebox. The solution was titrated to pH 6 by adding NaOH when a first precipitate formed, which was ferrous phosphate according to Mössbauer spectroscopy (MB). At that point the solution was removed from the glovebox and allowed to evaporate in the presence of atmospheric oxygen, leading to the oxidation of Fe2+. The evaporation rate was controlled by keeping the suspensions at different temperatures; pH was monitored during the evaporation process. The final precipitates were analyzed by MB and X-Ray Fluorescence (XRF), comparable to MER MB and Alpha Particle X-ray Spectrometer instrument datasets, and complementary techniques such as X

  16. Sodium nitroprusside may modulate Escherichia coli antioxidant enzyme expression by interacting with the ferric uptake regulator.

    Science.gov (United States)

    Bertrand, R; Danielson, D; Gong, V; Olynik, B; Eze, M O

    2012-01-01

    Efforts to explore possible relationships between nitric oxide (NO) and antioxidant enzymes in an Escherichia coli model have uncovered a possible interaction between sodium nitroprusside (SNP), a potent, NO-donating drug, and the ferric uptake regulator (Fur), an iron(II)--dependent regulator of antioxidant and iron acquisition proteins present in Gram-negative bacteria. The enzymatic profiles of superoxide dismutase and hydroperoxidase during logarithmic phase of growth were studied via non-denaturing polyacrylamide gel electrophoresis and activity staining specific to each enzyme. Though NO is known to induce transcription of the manganese-bearing isozyme of SOD (MnSOD), treatment with SNP paradoxically suppressed MnSOD expression and greatly enhanced the activity of the iron-containing equivalent (FeSOD). Fur, one of six global regulators of MnSOD transcription, is uniquely capable of suppressing MnSOD while enhancing FeSOD expression through distinct mechanisms. We thus hypothesize that Fur is complacent in causing this behaviour and that the iron(II) component of SNP is activating Fur. E. coli was also treated with the SNP structural analogues, potassium ferricyanide (PFi) and potassium ferrocyanide (PFo). Remarkably, the ferrous PFo was capable of mimicking the SNP-related pattern, whereas the ferric PFi was not. As Fur depends upon ferrous iron for activation, we submit this observation of redox-specificity as preliminary supporting evidence for the hypothesized Fur-SNP interaction. Iron is an essential metal that the human innate immune system sequesters to prevent its use by invading pathogens. As NO is known to inhibit iron-bound Fur, and as activated Fur regulates iron uptake through feedback inhibition, we speculate that the administration of this drug may disrupt this strategic management of iron in favour of residing Gram-negative species by providing a source of iron in an otherwise iron-scarce environment capable of encouraging its own uptake

  17. Removal of the blue 1 dye of aqueous solutions using ferric zeolite

    International Nuclear Information System (INIS)

    Pinedo H, S. Y.

    2010-01-01

    Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

  18. Optimizing iron delivery in the management of anemia: patient considerations and the role of ferric carboxymaltose

    Directory of Open Access Journals (Sweden)

    Toblli JE

    2014-12-01

    Full Text Available Jorge Eduardo Toblli, Margarita Angerosa Nephrology Section, Department of Internal Medicine, Hospital Alemán, School of Medicine, University of Buenos Aires, Argentina Abstract: With the challenge of optimizing iron delivery, new intravenous (iv iron–carbohydrate complexes have been developed in the last few years. A good example of these new compounds is ferric carboxymaltose (FCM, which has recently been approved by the US Food and Drug Administration for the treatment of iron deficiency anemia in adult patients who are intolerant to oral iron or present an unsatisfactory response to oral iron, and in adult patients with non-dialysis-dependent chronic kidney disease (NDD-CKD. FCM is a robust and stable complex similar to ferritin, which minimizes the release of labile iron during administration, allowing higher doses to be administered in a single application and with a favorable cost-effective rate. Cumulative information from randomized, controlled, multicenter trials on a diverse range of indications, including patients with chronic heart failure, postpartum anemia/abnormal uterine bleeding, inflammatory bowel disease, NDD-CKD, and those undergoing hemodialysis, supports the efficacy of FCM for iron replacement in patients with iron deficiency and iron-deficiency anemia. Furthermore, as FCM is a dextran-free iron–carbohydrate complex (which has a very low risk for hypersensitivity reactions with a small proportion of the reported adverse effects in a large number of subjects who received FCM, it may be considered a safe drug. Therefore, FCM appears as an interesting option to apply high doses of iron as a single infusion in a few minutes in order to obtain the quick replacement of iron stores. The present review on FCM summarizes diverse aspects such as pharmacology characteristics and analyzes trials on the efficacy/safety of FCM versus oral iron and different iv iron compounds in multiple clinical scenarios. Additionally, the

  19. Comparative impacts of iron oxide nanoparticles and ferric ions on the growth of Citrus maxima.

    Science.gov (United States)

    Hu, Jing; Guo, Huiyuan; Li, Junli; Gan, Qiuliang; Wang, Yunqiang; Xing, Baoshan

    2017-02-01

    The impacts of iron oxide nanoparticles (γ-Fe 2 O 3 NPs) and ferric ions (Fe 3+ ) on plant growth and molecular responses associated with the transformation and transport of Fe 2+ were poorly understood. This study comprehensively compared and evaluated the physiological and molecular changes of Citrus maxima plants as affected by different levels of γ-Fe 2 O 3 NPs and Fe 3+ . We found that γ-Fe 2 O 3 NPs could enter plant roots but no translocation from roots to shoots was observed. 20 mg/L γ-Fe 2 O 3 NPs had no impact on plant growth. 50 mg/L γ-Fe 2 O 3 NPs significantly enhanced chlorophyll content by 23.2% and root activity by 23.8% as compared with control. However, 100 mg/L γ-Fe 2 O 3 NPs notably increased MDA formation, decreased chlorophyll content and root activity. Although Fe 3+ ions could be used by plants and promoted the synthesis of chlorophyll, they appeared to be more toxic than γ-Fe 2 O 3 NPs, especially for 100 mg/L Fe 3+ . The impacts caused by γ-Fe 2 O 3 NPs and Fe 3+ were concentration-dependent. Physiological results showed that γ-Fe 2 O 3 NPs at proper concentrations had the potential to be an effective iron nanofertilizer for plant growth. RT-PCR analysis showed that γ-Fe 2 O 3 NPs had no impact on AHA gene expression. 50 mg/L γ-Fe 2 O 3 NPs and Fe 3+ significantly increased expression levels of FRO2 gene and correspondingly had a higher ferric reductase activity compared to both control and Fe(II)-EDTA exposure, thus promoting the iron transformation and enhancing the tolerance of plants to iron deficiency. Relative levels of Nramp3 gene expression exposed to γ-Fe 2 O 3 NPs and Fe 3+ were significantly lower than control, indicating that all γ-Fe 2 O 3 NPs and Fe 3+ treatments could supply iron to C. maxima seedlings. Overall, plants can modify the speciation and transport of γ-Fe 2 O 3 NPs or Fe 3+ for self-protection and development by activating many physiological and molecular processes. Copyright © 2016 Elsevier

  20. Application of granular ferric hydroxides for removal elevated concentrations of arsenic from mine waters

    Science.gov (United States)

    Szlachta, Małgorzata; Włodarczyk, Paweł; Wójtowicz, Patryk

    2015-04-01

    Arsenic is naturally occurring element in the environment. Over three hundred minerals are known to contain some form of arsenic and among them arsenopyrite is the most common one. Arsenic-bearing minerals are frequently associated with ores containing mined metals such as copper, tin, nickel, lead, uranium, zinc, cobalt, platinum and gold. In the aquatic environment arsenic is typically present in inorganic forms, mainly in two oxidation states (+5, +3). As(III) is dominant in more reduced conditions, whereas As(V) is mostly present in an oxidizing environment. However, due to certain human activities the elevated arsenic levels in aquatic ecosystems are arising to a serious environmental problem. High arsenic concentrations found in surface and groundwaters, in some regions originate from mining activities and ore processing. Therefore, the major concern of mining industry is to maintain a good quality of effluents discharged in large volumes. This requires constant monitoring of effluents quality that guarantee the efficient protection of the receiving waters and reacting to possible negative impact of contamination on local communities. A number of proven technologies are available for arsenic removal from waters and wastewaters. In the presented work special attention is given to the adsorption method as a technically feasible, commonly applied and effective technique for the treatment of arsenic rich mine effluents. It is know that arsenic has a strong affinity towards iron rich materials. Thus, in this study the granular ferric hydroxides (CFH 12, provided by Kemira Oyj, Finland) was applied to remove As(III) and As(V) from aqueous solutions. The batch adsorption experiments were carried out to assess the efficiency of the tested Fe-based material under various operating parameters, including composition of treated water, solution pH and temperature. The results obtained from the fixed bed adsorption tests demonstrated the benefits of applying granular

  1. Kinetic study of the reduction of Ferric-1, 10-Orthophenanthroline with Uranium (IV) DTPA

    International Nuclear Information System (INIS)

    Perveen, Rashida; Naqvi, Iftikhar Imam

    2006-01-01

    The reduction of ferric 1, 10-orthophenanthroline by Uranium (IV) complex of Diethylenetriaminepentaacetic acid was investigated in aqueous hydrochloride acid at 30C, ionic strength 0.01 mole dm-3 and pH 3.5. The mechanism and rate law for the formation of [Fe (opt) 3] was established by isolation method at constant and varying pH values. Spectroscopic method was employed for this investigation. The rate constant and order of reaction with respect to each of the reactant the [U (IV) DTPA] and [Fe(opt3)] was established by plotting a graph 1n (A-At) vs. time. The reaction was observed to be following first order with respect each of following reactants. Overall reaction order was found to be two, having the value of the rate constant 571.59 m min. at pH 3.5. Thermodynamic parameters for the reaction were determined to be E=26.47 kj mol, G=35.11 kj mol, H=24.86 mol and S= 50.17 mol. With the help of Arrhenius equation activation energy for the reaction was calculated. Change in enthalpy and entropy for the reaction (S, H) were determined from the slope and intercept of Eyring plot. Hydrogen ion dependence of the reaction was determined by varying the pH and the rate law was determined. (author)

  2. Glutathione-dependent extracellular ferric reductase activities in dimorphic zoopathogenic fungi

    Science.gov (United States)

    Zarnowski, Robert; Woods, Jon P.

    2009-01-01

    In this study, extracellular glutathione-dependent ferric reductase (GSH-FeR) activities in different dimorphic zoopathogenic fungal species were characterized. Supernatants from Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis and Sporothrix schenckii strains grown in their yeast form were able to reduce iron enzymically with glutathione as a cofactor. Some variations in the level of reduction were noted amongst the strains. This activity was stable in acidic, neutral and slightly alkaline environments and was inhibited when trivalent aluminium and gallium ions were present. Using zymography, single bands of GSH-FeRs with apparent molecular masses varying from 430 to 460 kDa were identified in all strains. The same molecular mass range was determined by size exclusion chromatography. These data demonstrate that dimorphic zoopathogenic fungi produce and secrete a family of similar GSH-FeRs that may be involved in the acquisition and utilization of iron. Siderophore production by these and other fungi has sometimes been considered to provide a full explanation of iron acquisition in these organisms. Our work reveals an additional common mechanism that may be biologically and pathogenically important. Furthermore, while some characteristics of these enzymes such as extracellular location, cofactor utilization and large size are not individually unique, when considered together and shared across a range of fungi, they represent an important novel physiological feature. PMID:16000713

  3. The effect of ammonium ferric hexacyanoferrate on reducing radiocaesium transfer from grass silage to sheep

    Directory of Open Access Journals (Sweden)

    A. PAASIKALLIO

    2008-12-01

    Full Text Available A study was carried out to examine the effect of ammonium ferric hexacyanoferrate (AFCF on the transfer of radiocaesium from grass silage to the tissues of male lambs. During ensiling, a formic acid based additive and AFCF were sprayed on grass contaminated with 134Cs and the mixture was allowed to incubate for 45 days. A dose of 21 mg AFCF d-1, fed to sheep offered contaminated silage for fourteen days, reduced 134Cs transfer to muscle by 45% compared to that of control sheep. An equivalent dose of AFCF administered in a capsule reduced transfer by only 3%. In another experiment, AFCF intake of 50, 100 and 150 mg d-1 for ten days reduced 134Cs transfer to sheep muscle by 75, 82 and 86%, respectively. In control lambs, of average live weight 38 and 47 kg, the feed to muscle 134Cs transfer coefficient averaged 0.15 d kg-1, but equilibrium between tissue and feed 134Cs had probably not been reached due to the short feeding period. Increasing doses of AFCF from 0 to 150 mg d-1 increased the faecal/urinary 134Cs ratio from 2 to 42.;

  4. Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

    Directory of Open Access Journals (Sweden)

    Messias Borges Silva

    2013-04-01

    Full Text Available Leachates exhibiting an unstable ratio of biochemical oxygen demand (BOD and chemical oxygen demand (COD of approximately 0.45 are typical of new landfills in the City of Cachoeira Paulista, Brazil. Although the organic matter portion is bio-treatable, the presence of refractory leached organic material requires unconventional effluent-treatment processes. Leachate treatment with ozone oxidation, in the presence of ferric ions, acts as catalyst in the formation of hydroxyl radicals. Ozone was obtained by corona-discharge from high-purity O2 gas. The treatment was performed in natura in a jacketed borosilicate glass reactor containing 900 ml of leachate. The analyzed response variable was expressed as the concentration of dissolved organic carbon (DOC. In order to determine the optimal proportions to produce the greatest degradation rate for organic materials, variations in experimental O2 flow-fed to the generator, the Fe(iii concentration, and the output of the ozonator were conducted over two experimental runs. Experimental models showed a DOC degradation on the order of 81.25%.

  5. Acid-curing and ferric-trickle leaching effluent used in closed circuit uranium extractive process

    International Nuclear Information System (INIS)

    Jin Suoqing; Xiang Qinfang; Guo Jianzheng; Lu Guizhu; Su Yanru

    1998-01-01

    The new uranium ore process consists of crushing ore, mixing crushed ore with strong acid in rotating drums and curing the mixture in piles, trickle-leaching the ore beds with ferric solution, extracting uranium from pregnant solution with tertiary amine, precipitating product and disposing residue tailings. All the process effluent is used in closed circuit. There will be no process water to be discharged in the flowsheet except the tailings carrying off 15% water because during leaching moisture content of the ore rises to 15%. Tailings produced by the process are moist and friable, and can be disposed of on a pile or returned to the mine. Main technical parameters of the process: (a) water consumption is 0.2∼0.3 m 3 /t ore, electric power consumption is 20∼30 kW·h/t ore; (b) ore crushing up to -5∼-7 mm, leaching period is 12∼45 d, U content of residue is 0.01%∼0.02%, producing pregnant solution is 0.3∼0.5 m 3 /t ore, which is 1/5∼1/8 that of conventional agitation leaching process; (c) organic agent consumption is 1/5∼1/8 that of the conventional agitation process. All the research results above are tested by the pilot-plant test and industrial test. The new process has been applied to recovery of uranium in the mine located at northeast of China

  6. AMOEBA Polarizable Force Field Parameters of the Heme Cofactor in Its Ferrous and Ferric Forms.

    Science.gov (United States)

    Wu, Xiaojing; Clavaguera, Carine; Lagardère, Louis; Piquemal, Jean-Philip; de la Lande, Aurélien

    2018-04-16

    We report the first parameters of the heme redox cofactors for the polarizable AMOEBA force field in both the ferric and ferrous forms. We consider two types of complexes, one with two histidine side chains as axial ligands and one with a histidine and a methionine side chain as ligands. We have derived permanent multipoles from second-order Møller-Plesset perturbation theory (MP2). The sets of parameters have been validated in a first step by comparison of AMOEBA interaction energies of heme and a collection of biologically relevant molecules with MP2 and Density Functional Theory (DFT) calculations. In a second validation step, we consider interaction energies with large aggregates comprising around 80 H 2 O molecules. These calculations are repeated for 30 structures extracted from semiempirical PM7 DM simulations. Very encouraging agreement is found between DFT and the AMOEBA force field, which results from an accurate treatment of electrostatic interactions. We finally report long (10 ns) MD simulations of cytochromes in two redox states with AMOEBA testing both the 2003 and 2014 AMOEBA water models. These simulations have been carried out with the TINKER-HP (High Performance) program. In conclusion, owing to their ubiquity in biology, we think the present work opens a wide array of applications of the polarizable AMOEBA force field on hemeproteins.

  7. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    Energy Technology Data Exchange (ETDEWEB)

    Peng Zhang' e [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: zhepeng@126.com; Wu Feng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: fengwu@whu.edu.cn; Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: nsdengwhu@163.com

    2006-12-15

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe{sup 3+} ions was investigated. Algae, humic acid and Fe{sup 3+} ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10{sup 9} cells L{sup -1} raw Chlorella vulgaris, 4 mg L{sup -1} humic acid and 20 {mu}mol L{sup -1} Fe{sup 3+}. The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment.

  8. Indirect spectrophotometric determination of arbutin, whitening agent through oxidation by periodate and complexation with ferric chloride

    Science.gov (United States)

    Barsoom, B. N.; Abdelsamad, A. M. E.; Adib, N. M.

    2006-07-01

    A simple and accurate spectrophotometric method for the determination of arbutin (glycosylated hydroquinone) is described. It is based on the oxidation of arbutin by periodate in presence of iodate. Excess periodate causes liberation of iodine at pH 8.0. The unreacted periodate is determined by measurement of the liberated iodine spectrophotometrically in the wavelength range (300-500 nm). A calibration curve was constructed for more accurate results and the correlation coefficient of linear regression analysis was -0.9778. The precision of this method was better than 6.17% R.S.D. ( n = 3). Regression analysis of Bear-Lambert plot shows good correlation in the concentration range 25-125 ug/ml. The identification limit was determined to be 25 ug/ml a detailed study of the reaction conditions was carried out, including effect of changing pH, time, temperature and volume of periodate. Analyzing pure and authentic samples containing arbutin tested the validity of the proposed method which has an average percent recovery of 100.86%. An alternative method is also proposed which involves a complexation reaction between arbutin and ferric chloride solution. The produced complex which is yellowish-green in color was determined spectophotometrically.

  9. Determination of the molar extinction coefficient for the ferric reducing/antioxidant power assay.

    Science.gov (United States)

    Hayes, William A; Mills, Daniel S; Neville, Rachel F; Kiddie, Jenna; Collins, Lisa M

    2011-09-15

    The FRAP reagent contains 2,4,6-tris(2-pyridyl)-s-triazine, which forms a blue-violet complex ion in the presence of ferrous ions. Although the FRAP (ferric reducing/antioxidant power) assay is popular and has been in use for many years, the correct molar extinction coefficient of this complex ion under FRAP assay conditions has never been published, casting doubt on the validity of previous calibrations. A previously reported value of 19,800 is an underestimate. We determined that the molar extinction coefficient was 21,140. The value of the molar extinction coefficient was also shown to depend on the type of assay and was found to be 22,230 under iron assay conditions, in good agreement with published data. Redox titration indicated that the ferrous sulfate heptahydrate calibrator recommended by Benzie and Strain, the FRAP assay inventors, is prone to efflorescence and, therefore, is unreliable. Ferrous ammonium sulfate hexahydrate in dilute sulfuric acid was a more stable alternative. Few authors publish their calibration data, and this makes comparative analyses impossible. A critical examination of the limited number of examples of calibration data in the published literature reveals only that Benzie and Strain obtained a satisfactory calibration using their method. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Will the application of Ammonium-Ferric-Hexacyano-Ferrate enhance the vertical migration of radiocaesium?

    International Nuclear Information System (INIS)

    Vandenhove, H.; Bacquoy, C.; Hees, M. van; Lewyckyj, N.; Vandecasteele, C.

    1998-01-01

    The consideration of a possible enhanced vertical migration of radiocaesium with the application of ammonium-ferric-hexacyano-ferrate (AFCF) as countermeasure, due to the colloidal nature of AFCF, made us set up a series of migration experiments. For the study two soil types were considered, which were either left unplanted or cultivated with ryegrass. Two AFCF concentrations, 1 and 10 g m -2 , and an untreated control were applied. A simple diffusion-convection model was fitted to the data.The application of AFCF did not enhance the downward migration of radiocaesium in the profile. Moreover, for an unplanted sandy soil the application of AFCF significantly retarded the migration: 10 g AFCF m -2 decreased the convection term, V, from 0·78 to 0·42 cm a -1 and the diffusion component, D, from 0·21 to 0·09 cm 2 a -1 . For all other experimental conditions (unplanted loamy soil, ryegrass cultivated sandy and loamy soil), the application of AFCF did not have any effect on radiocaesium migration. Since AFCF does not promote the vertical migration of radiocaesium, enhanced groundwater contamination is improbable. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  12. Selective depression mechanism of ferric chromium lignin sulfonate for chalcopyrite-galena flotation separation

    Science.gov (United States)

    Yu, Jin-sheng; Liu, Run-qing; Wang, Li; Sun, Wei; Peng, Hong; Hu, Yue-hua

    2018-05-01

    Selective recovery of chalcopyrite-galena ore by flotation remains a challenging issue. The development of highly efficient, low-cost, and environmentally friendly depressants for this flotation is necessary because most of available reagents (e.g., K2Cr2O4) are expensive and adversely affect the environment. In this study, ferric chromium lignin sulfonate (FCLS), which is a waste-product from the paper and pulp industry, was introduced as a selective depressant for galena with butyl xanthate (BX) as a collector. Results show that the residue recovery of Pb in Cu concentrate was substantially reduced to 4.73% using FCLS compared with 10.71% using the common depressant K2Cr2O4. The underlying mechanisms were revealed using zeta-potential measurements and X-ray photoelectron spectroscopy (XPS). Zeta-potential measurements revealed that FCLS was more efficiently absorbed onto galena than onto chalcopyrite. XPS measurements further suggested that FCLS enhanced the surface oxidation of galena but prevented that of chalcopyrite. Thus, FCLS could be a potential candidate as a depressant for chalcopyrite-galena flotation because of its low cost and its lack of detrimental effects on the environment.

  13. A radioisotope study of the dispersion of ferric hydroxide floc in Bass Strait

    International Nuclear Information System (INIS)

    Davison, A.

    1983-01-01

    The dispersion of ferric hydroxide floc in Bass Strait waters adjacent to Burnie, Tasmania, has been investigated using radioisotope tracer techniques. Gold-198 labelled floc was employed to follow the movement of floc produced by dilution of the iron-rich effluent from a titanium dioxide plant. Dispersion was determined under calm and storm conditions. Tidal and wind-driven currents were measured, oscillating wave generated currents were calculated, and lateral and vertical dispersion coefficients were determined. It is concluded that floc disperses episodically during storms. The agglomerated floc remains trapped in a stable seabed layer which spreads slowly at seabed level when wind velocities are less than 15 m s -1 . When wind velocities exceed this level, the wave generated oscillating currents at seabed level, 30 m below the surface, are strong enough to raise the floc into suspension where advective dispersion occurs. Since tidal currents in the area are negligible, the direction of floc movement depends on the direction of the wind-driven current during each storm

  14. Ferric oxide nanoparticles decorated carbon nanotubes and carbon nanofibers: From synthesis to enhanced removal of phenol

    Directory of Open Access Journals (Sweden)

    Hamza A. Asmaly

    2015-09-01

    Full Text Available In this work, ferric oxide nanoparticle decorated carbon fibers and carbon nanotubes (CNF/Fe2O3 and CNT/Fe2O3 were synthesized and characterized by scanning electron microscopy (SEM, thermogravimetric analysis (TGA, energy dispersive X-ray spectroscopy (EDS, transmission electron microscopy (TEM, X-ray diffraction (XRD, zeta potential and BET surface area analyzer. The prepared nanocomposites were evaluated or the removal of phenol ions from aqueous solution. The effects of experimental parameters, such as shaking speed, pH, contact time, adsorbent dosage and initial concentration, were evaluated for the phenol removal efficiency. The adsorption experimental data were represented by both the Langmuir and Freundlich isotherm models. The Langmuir isotherm model best fitted the data on the adsorption of phenol, with a high correlation coefficient. The adsorption capacities, as determined by the Langmuir isotherm model were 0.842, 1.098, 1.684 and 2.778 mg/g for raw CNFs, raw CNTs, CNF–Fe2O3 and CNT–Fe2O3, respectively.

  15. Effect of Arsenic on the Formation and Adsorption Property of Ferric Hydroxide Precipitates in ZVI Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xing; Xi, Beidou; Zhao, Ying; Shi, Qiantao; Meng, Xiaoguang; Mao, Xuhui; Jiang, Yonghai; Ma, Zhifei; Tan, Wenbing; Liu, Hongliang; Gong, Bin (Stevens); (Beijing NU); (CRAES); (Wuhan)

    2017-08-14

    Treatment of arsenic by zerovalent iron (ZVI) has been studied extensively. However, the effect of arsenic on the formation of ferric hydroxide precipitates in the ZVI treatment has not been investigated. We discovered that the specific surface area (ca. 187 m2/g) and arsenic content (ca. 67 mg/g) of the suspended solids (As-containing solids) generated in the ZVI treatment of arsenic solutions were much higher than the specific surface area (ca. 37 m2/g) and adsorption capacity (ca.12 mg/g) of the suspended solids (As-free solids) generated in the arsenic-free solutions. Arsenic in the As-containing solids was much more stable than the adsorbed arsenic in As-free solids. XRD, SEM, TEM, and selected area electron diffraction (SAED) analyses showed that the As-containing solids consisted of amorphous nanoparticles, while the As-free solids were composed of micron particles with weak crystallinity. Extended X-ray absorption fine structure (EXAFS) analysis determined that As(V) was adsorbed on the As-containing suspended solids and magnetic solid surfaces through bidentate binuclear complexation; and As(V) formed a mononuclear complex on the As-free suspended solids. The formation of the surface As(V) complexes retarded the bonding of free FeO6 octahedra to the oxygen sites on FeO6 octahedral clusters and prevented the growth of the clusters and their development into 3-dimensional crystalline phases.

  16. Solar Ultraviolet-B Radiation Increases Phenolic Content and Ferric Reducing Antioxidant Power in Avena sativa

    Directory of Open Access Journals (Sweden)

    Christopher T. Ruhland

    2007-06-01

    Full Text Available We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm on the maximum photochemical efficiency of photosystem II (Fv/Fm, bulk-soluble phenolic concentrations, ferric-reducing antioxidant power (FRAP and growth of Avena sativa. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B by either 71% (reduced UV-B or by 19% (near-ambient UV-B over the 52 day experiment (04 July - 25 August 2002. Plants growing under near-ambient UV-B had 38% less total biomass than those under reduced UV-B. The reduction in biomass was mainly the result of a 24% lower leaf elongation rate, resulting in shorter leaves and less total leaf area than plants under reduced UV-B. In addition, plants growing under near-ambient UV-B had up to 17% lower Fv/Fm values early in the experiment, and this effect declined with plant age. Concentrations of bulk-soluble phenolics and FRAP values were 17 and 24% higher under near-ambient UV-B than under reduced UV-B, respectively. There was a positive relationship between bulk-soluble phenolic concentrations and FRAP values. There were no UV-B effects on concentrations of carotenoids (carotenes + xanthophylls.

  17. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    International Nuclear Information System (INIS)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige; Chen, Xingguo

    2015-01-01

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe 3+ ion sensing by fluorescence quenching is developed. • The method for Fe 3+ sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe 3+ ) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe 3+ permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe 3+ in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%

  18. EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

    2005-07-01

    Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

  19. Enhancement of Fenton oxidation for removing organic matter from hypersaline solution by accelerating ferric system with hydroxylamine hydrochloride and benzoquinone.

    Science.gov (United States)

    Peng, Siwei; Zhang, Weijun; He, Jie; Yang, Xiaofang; Wang, Dongsheng; Zeng, Guisheng

    2016-03-01

    Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions. This study investigated the feasibility of using benzoquinone (BQ) and hydroxylamine hydrochloride (HA) as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by accelerating the ferric system. It was found that organics removal was not obviously affected by chloride ions of low concentration (less than 0.1mol/L), while the mineralization rate was strongly inhibited in the presence of a large amount of chloride ions. In addition, ferric hydrolysis-precipitation was significantly alleviated in the presence of HA and BQ, and HA was more effective in reducing ferric ions into ferrous ions than HA, while the H2O2 decomposition rate was higher in the BQ-Fenton system. Electron spin resonance analysis revealed that OH production was reduced in high salinity conditions, while it was enhanced after the addition of HA and BQ (especially HA). This study provided a possible solution to control and alleviate the inhibitory effect of chloride ions on the Fenton process for organics removal. Copyright © 2015. Published by Elsevier B.V.

  20. Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

    Science.gov (United States)

    Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

    2008-09-19

    It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

  1. Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

    Science.gov (United States)

    Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

    2011-12-01

    Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

  2. Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate

    Science.gov (United States)

    Deike, R.G.; Granina, L.; Callender, E.; McGee, J.J.

    1997-01-01

    Phosphate-bearing, ferric iron and siliceous crusts ranging in age from Recent to approximately 65,000 yr B.P. are observed in sediments of Lake Baikal. In younger sediments the crusts are at the base of a spectrum of secondary iron and manganese oxides that accumulate near the sediment/water interface in the zone of positive oxidation potential beneath an oxygenated water column. In areas where the average Quaternary sedimentation rates have been slow (e.g. 0.026 mm/yr), the crusts are more common, and span a wider range of ages. No crusts have been found where the Quaternary sedimentation mode has been deltaic and rapid (0.15 mm/yr). Independent core correlation based on magnetic properties of the sediment suggests that crusts can be correlated over most of Academician Ridge, an area that is particularly sensitive to climatic events affecting the concentration of suspended sediment. These crusts may be indicative of periods of low suspended sediment concentration, which occur during sustained transitions from glacial periods of high detrital input, to interglacial periods of high diatom sedimentation. The crusts are dominated by iron-rich and siliceous amorphous mineral phases, with an FeO:SiO2 by weight of 3:1. Regardless of age or location in the lake the Fe phase always includes Ca, P and Mn. Extensive microprobe data for these four elements recast as normalized elemental weight percent reveal linear trends of Ca:P and Fe:P. With increasing P, Ca also increases such that the two elements maintain a linear relationship passing very close to the origin and with a mean molar Ca:P=0.3 (too low for well-characterized apatite). Conversely, with increasing P, Fe decreases (mean molar Fe:P=3.4). There is no correlation between Mn and P. Molar Fe:P ratios for vivianite (an Fe(II) phosphate mineral observed in sediments closely below some crusts) are clustered around a stoichiometric composition. The covariant increase in Ca:P and the corresponding decrease in Fe:P may

  3. Effect of ammonium and nitrate on ferric chelate reductase and nitrate reductase in Vaccinium species.

    Science.gov (United States)

    Poonnachit, U; Darnell, R

    2004-04-01

    Most Vaccinium species have strict soil requirements for optimal growth, requiring low pH, high iron availability and nitrogen primarily in the ammonium form. These soils are limited and are often located near wetlands. Vaccinium arboreum is a wild species adapted to a wide range of soils, including high pH, low iron, and nitrate-containing soils. This broader soil adaptation in V. arboreum may be related to increased efficiency of iron or nitrate uptake compared with the cultivated Vaccinium species. Nitrate, ammonium and iron uptake, and nitrate reductase (NR) and ferric chelate reductase (FCR) activities were compared in two Vaccinium species grown hydroponically in either nitrate or ammonia, with or without iron. The species studied were the wild V. arboreum and the cultivated V. corymbosum interspecific hybrid, which exhibits the strict soil requirements of most Vaccinium species. Ammonium uptake was significantly greater than nitrate uptake in both species, while nitrate uptake was greater in the wild species, V. arboreum, compared with the cultivated species, V. corymbosum. The increased nitrate uptake in V. arboreum was correlated with increased root NR activity compared with V. corymbosum. The lower nitrate uptake in V. corymbosum was reflected in decreased plant dry weight in this species compared with V. arboreum. Root FCR activity increased significantly in V. corymbosum grown under iron-deficient conditions, compared with the same species grown under iron-sufficient conditions or with V. arboreum grown under either iron condition. V. arboreum appears to be more efficient in acquiring nitrate compared with V. corymbosum, possibly due to increased NR activity and this may partially explain the wider soil adaptation of V. arboreum.

  4. Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink.

    Science.gov (United States)

    Roe, Mark A; Collings, Rachel; Hoogewerff, Jurian; Fairweather-Tait, Susan J

    2009-03-01

    Food iron fortification is a sustainable and relatively simple strategy to reduce/prevent iron deficiency but is a challenge for the food industry because of possible adverse organoleptic changes caused by the added iron. A micronized dispersible ferric pyrophosphate, trademarked as SunActive Fe, has recently been developed. SunActive Fe has a small particle size, is water soluble and may be suitable for fortifying liquid products. To determine the relative bioavailability of SunActive Fe and its suitability for addition to pure apple juice. Iron absorption from SunActive Fe added to pure apple juice (Minute Maid) was compared with absorption from ferrous sulphate, a highly bioavailable form of iron, in 15 women with relatively low iron stores. Both forms of iron were enriched with an iron stable isotope and iron absorption from the apple juice drinks was calculated from the isotopic enrichment of red blood cells 14 days after the last test meal. Although mean absorption of iron from SunActive Fe was significantly lower than from ferrous sulphate (5.5% compared with 9.1%), the mean bioavailability of SunActive Fe iron relative to ferrous sulphate was 0.6, indicating that it is a good source of bioavailable iron. Iron Absorption from SunActive Fe was positively correlated (r = 0.97, P = 0.01) with absorption from ferrous sulphate, and negatively correlated with serum ferritin concentration (ferrous sulphate r = -0.81, P apple juice and is a potentially useful fortificant for liquid food products.

  5. Arsenic Adsorption Equilibrium Concentration and Adsorption Rate of Activated Carbon Coated with Ferric-Aluminum Hydroxides

    Science.gov (United States)

    Zhang, M.; Sugita, H.; Oguma, T.; Hara, J.; Takahashi, S.

    2015-12-01

    In some areas of developing countries, ground or well water contaminated with arsenic has been reluctantly used as drinking water. It is highly desirable that effective and inexpensive arsenic removal agents should be developed and provided to reduce the potential health risk. Previous studies demonstrated that activated carbon coated with ferric-aluminum hydroxides (Fe-Al-C) has high adsorptive potential for removal of arsenic. In this study, a series of experiments using Fe-Al-C were carried to discuss adsorption equilibrium time, adsorption equilibrium concentration and adsorption rate of arsenic for Fe-Al-C. Fe-Al-C used in this study was provided by Astec Co., Ltd. Powder reagent of disodium hydrogen arsenate heptahydrate was dissolved into ion-exchanged water. The solution was then further diluted with ion-exchanged water to be 1 and 10 mg/L as arsenic concentration. The pH of the solution was adjusted to be around 7 by adding HCl and/or NaOH. The solution was used as artificial arsenic contaminated water in two types of experiments (arsenic adsorption equilibrium and arsenic adsorption rate tests). The results of the arsenic equilibrium tests were showed that a time period of about 3 days to reach apparent adsorption equilibrium for arsenic. The apparent adsorption equilibrium concentration and adsorbed amount of arsenic on Fe-Al-C adsorbent could be estimated by application of various adsorption isotherms, but the distribution coefficient of arsenic between solid and liquid varies with experimental conditions such as initial concentration of arsenic and addition concentration of adsorbent. An adsorption rate equation that takes into account the reduction in the number of effective adsorption sites on the adsorbent caused by the arsenic adsorption reaction was derived based on the data obtained from the arsenic adsorption rate tests.

  6. The Porphyromonas gingivalis ferric uptake regulator orthologue binds hemin and regulates hemin-responsive biofilm development.

    Directory of Open Access Journals (Sweden)

    Catherine A Butler

    Full Text Available Porphyromonas gingivalis is a Gram-negative pathogen associated with the biofilm-mediated disease chronic periodontitis. P. gingivalis biofilm formation is dependent on environmental heme for which P. gingivalis has an obligate requirement as it is unable to synthesize protoporphyrin IX de novo, hence P. gingivalis transports iron and heme liberated from the human host. Homeostasis of a variety of transition metal ions is often mediated in Gram-negative bacteria at the transcriptional level by members of the Ferric Uptake Regulator (Fur superfamily. P. gingivalis has a single predicted Fur superfamily orthologue which we have designated Har (heme associated regulator. Recombinant Har formed dimers in the presence of Zn2+ and bound one hemin molecule per monomer with high affinity (Kd of 0.23 µM. The binding of hemin resulted in conformational changes of Zn(IIHar and residue 97Cys was involved in hemin binding as part of a predicted -97C-98P-99L- hemin binding motif. The expression of 35 genes was down-regulated and 9 up-regulated in a Har mutant (ECR455 relative to wild-type. Twenty six of the down-regulated genes were previously found to be up-regulated in P. gingivalis grown as a biofilm and 11 were up-regulated under hemin limitation. A truncated Zn(IIHar bound the promoter region of dnaA (PGN_0001, one of the up-regulated genes in the ECR455 mutant. This binding decreased as hemin concentration increased which was consistent with gene expression being regulated by hemin availability. ECR455 formed significantly less biofilm than the wild-type and unlike wild-type biofilm formation was independent of hemin availability. P. gingivalis possesses a hemin-binding Fur orthologue that regulates hemin-dependent biofilm formation.

  7. Sodium pyrophosphate enhances iron bioavailability from bouillon cubes fortified with ferric pyrophosphate.

    Science.gov (United States)

    Cercamondi, Colin I; Duchateau, Guus S M J E; Harika, Rajwinder K; van den Berg, Robin; Murray, Peter; Koppenol, Wieneke P; Zeder, Christophe; Zimmermann, Michael B; Moretti, Diego

    2016-08-01

    Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (P<0·005) when comparing bouillons fortified with FePP only (4·4 %) and bouillons fortified with FePP+NaPP (6·4 %). Fe absorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well.

  8. Surface complexation modeling of Cu(II adsorption on mixtures of hydrous ferric oxide and kaolinite

    Directory of Open Access Journals (Sweden)

    Schaller Melinda S

    2008-09-01

    Full Text Available Abstract Background The application of surface complexation models (SCMs to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids. Results Cu adsorption was measured on pure hydrous ferric oxide (HFO, pure kaolinite (from two sources and in systems containing mixtures of HFO and kaolinite over a wide range of pH, ionic strength, sorbate/sorbent ratios and, for the mixed solid systems, using a range of kaolinite/HFO ratios. Cu adsorption data measured for the HFO and kaolinite systems was used to derive diffuse layer surface complexation models (DLMs describing Cu adsorption. Cu adsorption on HFO is reasonably well described using a 1-site or 2-site DLM. Adsorption of Cu on kaolinite could be described using a simple 1-site DLM with formation of a monodentate Cu complex on a variable charge surface site. However, for consistency with models derived for weaker sorbing cations, a 2-site DLM with a variable charge and a permanent charge site was also developed. Conclusion Component additivity predictions of speciation in mixed mineral systems based on DLM parameters derived for the pure mineral systems were in good agreement with measured data. Discrepancies between the model predictions and measured data were similar to those observed for the calibrated pure mineral systems. The results suggest that quantifying specific interactions between HFO and kaolinite in speciation models may not be necessary. However, before the component additivity approach can be applied to natural sediments and soils, the effects of aging must be further studied and methods must be developed to estimate reactive surface areas of solid constituents in natural samples.

  9. Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

    International Nuclear Information System (INIS)

    Mansonr, S.Z.

    2009-01-01

    Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

  10. Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

    International Nuclear Information System (INIS)

    Mansonr, S.Z.

    2008-01-01

    Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

  11. Iron-reducing bacteria accumulate ferric oxyhydroxide nanoparticle aggregates that may support planktonic growth.

    Science.gov (United States)

    Luef, Birgit; Fakra, Sirine C; Csencsits, Roseann; Wrighton, Kelly C; Williams, Kenneth H; Wilkins, Michael J; Downing, Kenneth H; Long, Philip E; Comolli, Luis R; Banfield, Jillian F

    2013-02-01

    Iron-reducing bacteria (FeRB) play key roles in anaerobic metal and carbon cycling and carry out biogeochemical transformations that can be harnessed for environmental bioremediation. A subset of FeRB require direct contact with Fe(III)-bearing minerals for dissimilatory growth, yet these bacteria must move between mineral particles. Furthermore, they proliferate in planktonic consortia during biostimulation experiments. Thus, a key question is how such organisms can sustain growth under these conditions. Here we characterized planktonic microbial communities sampled from an aquifer in Rifle, Colorado, USA, close to the peak of iron reduction following in situ acetate amendment. Samples were cryo-plunged on site and subsequently examined using correlated two- and three-dimensional cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission X-ray microscopy (STXM). The outer membranes of most cells were decorated with aggregates up to 150 nm in diameter composed of ∼3 nm wide amorphous, Fe-rich nanoparticles. Fluorescent in situ hybridization of lineage-specific probes applied to rRNA of cells subsequently imaged via cryo-TEM identified Geobacter spp., a well-studied group of FeRB. STXM results at the Fe L(2,3) absorption edges indicate that nanoparticle aggregates contain a variable mixture of Fe(II)-Fe(III), and are generally enriched in Fe(III). Geobacter bemidjiensis cultivated anaerobically in the laboratory on acetate and hydrous ferric oxyhydroxides also accumulated mixed-valence nanoparticle aggregates. In field-collected samples, FeRB with a wide variety of morphologies were associated with nano-aggregates, indicating that cell surface Fe(III) accumulation may be a general mechanism by which FeRB can grow while in planktonic suspension.

  12. Low-spin states of 23Na

    International Nuclear Information System (INIS)

    Bakkum, E.L.

    1987-01-01

    A study of 23 Na via the 22 Ne(p,γ) 23 Na and 23 Na(γ,γ) 23 Na reactions is presented. Only a limited number of resonances has been studied, selected on the basis of strong excitation of the lowest levels of which the spin was unknown. As a result the spins are now known of all levels of 23 Na with excitation energies up to 7 MeV, except for a few high-spin states which are too weakly excited in the decay of the known 22 Ne(p,γ) resonances. The mean lifetimes of the 23 Na levels at 4.43 and 7.89 MeV were found to be 350±70 and 220±17 attoseconds (1 attosecond = 10 -18 seconds) respectively. 97 refs.; 22 figs.; 12 tabs

  13. The new generation of intravenous iron: chemistry, pharmacology, and toxicology of ferric carboxymaltose.

    Science.gov (United States)

    Funk, Felix; Ryle, Peter; Canclini, Camillo; Neiser, Susann; Geisser, Peter

    2010-01-01

    An ideal preparation for intravenous iron replacement therapy should balance effectiveness and safety. Compounds that release iron rapidly tend to cause toxicity, while large molecules can induce antibody formation and cause anaphylactic reactions. There is therefore a need for an intravenous iron preparation that delivers appropriate amounts of iron in a readily available form but with minimal side effects and thus with an excellent safety profile. In this paper, a review is given on the chemistry, pharmacology, and toxicology of ferric carboxymaltose (FCM, Ferinject), a stable and robust complex formulated as a colloidal solution with a physiological pH. The complex is gradually taken up mainly from the hepatic reticulo-endothelial system (RES), followed by effective delivery of iron to the endogeneous transport system for the haem synthesis in new erythrocytes, as shown in studies on the pharmacodynamics and pharmacokinetics with radio-labelled FCM. Studies with radio-labelled FCM also demonstrated a barrier function of the placenta and a low transfer of iron into the milk of lactating rats. Safety pharmacology studies indicated a favourable profile with regard to cardiovascular, central nervous, respiratory, and renal toxicity. A high maximum non-lethal dose was demonstrated in the single-dose toxicity studies. Furthermore, based on the No-Observed-Adverse-Effect-Levels (NOAELs) found in repeated-dose toxicity studies and on the cumulative doses administered, FCM has good safety margins. Reproductive and developmental toxicity studies did not reveal any direct or indirect harmful effects. No genotoxic potential was found in in vitro or in vivo studies. Moreover, antigenicity studies showed no cross-reactivity of FMC with anti-dextran antibodies and also suggested that FCM does not possess sensitizing potential. Lastly, no evidence of irritation was found in local tolerance studies with FCM. This excellent toxicity profile and the high effectiveness of FCM allow

  14. Ferric iron partitioning between pyroxene and melt during partial melting of the Earth's upper mantle

    Science.gov (United States)

    Rudra, A.; Hirschmann, M. M.

    2017-12-01

    The oxidation state of the Earth's mantle influences melt production, volatile behavior, partitioning of key trace elements and possible saturation of alloy at depth. Average Fe3+/FeT ratios in MORBs indicate oxygen fugacitiy of the source regions is close to QFM, in contrast to a 3 log unit variation of fO2 recorded by abyssal peridotites. Quantification of the relationship between basalt and source Fe3+/FeT, oxygen fugacity, and melting requires constraints on Fe3+ partitioning between melt and mantle minerals and in particular the principal Fe3+ host, pyroxene. McCanta et al. (2004) investigated valence dependent partitioning of Fe between Martian ferroan pigeonites and melt, but behavior in terrestrial pyroxene compositions relevant to MORB petrogenesis has not been investigated. We are conducting 1 atm controlled fO2 experiments over 4 log unit variation of fO2 between ΔQFM = 2.5 to -1.5 to grow pyroxenes of variable tetrahedral and octahedral cationic population from andesitic melts of varying Mg#, alumina and alkali content. Dynamic crystallization technique facilitates growth of pyroxene crystals (100-200 um) that EPMA analyses show to be compositionally homogeneous and in equilibrium with the melt. Fe3+/FeT ratio of the synthetic pyroxenes have been analyzed by XAFS spectroscopy at the APS (GSECARS) synchrotron. To quantify the x-ray anisotropy in pyroxenes, we collected Fe K-edge XAFS spectra of oriented natural single crystals for a wide range compositions whose Fe3+/FeT ratios we determined by Mossbauer spectroscopy. We have collected both XANES and EXAFS spectral regions spanning from 7020-7220 eV to explore predictive capabilities of different spectral regions about ferric iron concentration and site occupancy. Our results will document the Fe3+ compatibility in pyroxenes of different compositions under a variety of fO2 conditions, which in turn will better constrain the interrelationship between mantle redox and melting.

  15. Study of the Efficiency of Arsenic Removal from Drinking Water by Granular Ferric Hydroxide (GFH

    Directory of Open Access Journals (Sweden)

    A.R Asgari

    2012-05-01

    Full Text Available

    Background and Objective

    Pollution of surface and ground water to arsenic (As has been reported from many parts of the world and in some regions of Iran especially in Kurdistan province. Natural pollution of water to As is in fact dependent to geological characteristics of a region. To day, various methods have been recommended for As removal that each of which has special advantages and drawbacks. Granular ferric hydroxide (GFH is a relatively new adsorbent available in market which is principally introduced for As removal.

     

    Methods

    This study was an applied survey in which the effects of changing contact time, As concentration, adsorbent weight, pH as well as the effect of sulfate and chloride ions in arsenic removal were determined. Moreover, the model of absorption by GFH was studied and compared with Freundlich and Langmuir models. Raw data were analyzed by Excel and SPSS softwares.

     

    Results

    Results showed that As adsorption by GFH imitate both the Freundlich and Langmuir equations (with R2 >0.95. Optimum PH was 7.5 and duration of the process about 30 minutes was sufficient for optimum removal of As. It was also found that efficiency of As removal was high when small amounts of adsorbent were used. Furthermore, sulfate and chloride ions in concentrations used in this study had no noticeable effect on As removal and Fe added during process remains in the water more than the standard value (0.3 mg/l.

     

    Conclusion

    According to this study, GFH could be considered as a suitable adsorbent for As removal from polluted water resources because of its high performance without any needs to PH adjustment. However, there are few drawbacks such as Fe addition and relatively high initial cost.

  16. Assessing the costs and benefits of perioperative iron deficiency anemia management with ferric carboxymaltose in Germany

    Directory of Open Access Journals (Sweden)

    Froessler B

    2018-04-01

    Full Text Available Bernd Froessler,1,2 Alexandra M Rueger,3,4 Mark P Connolly5,6 1Department of Anesthesia, Lyell McEwin Hospital, Elizabeth Vale, SA, Australia; 2Discipline of Acute Care Medicine, University of Adelaide, Adelaide, SA, Australia; 3Vifor Pharma, Munich, Germany; 4Charité Universitätsmedizin Berlin, Medizinische Klinik mit Schwerpunkt Kardiologie Campus Virchow-Klinikum, Berlin, Germany; 5Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy, University of Groningen, Groningen, the Netherlands; 6Global Market Access Solutions Sàrl, St-Prex, Switzerland Background: Perioperative administration of ferric carboxymaltose (FCM was previously shown to reduce both the need for transfusions and the hospital length of stay in patients with preoperative iron deficiency anemia (IDA. In this study, we estimated the economic consequences of perioperative administration using FCM vs usual care in patients with IDA from the perspective of a German hospital using decision-analytic modeling.Materials and methods: The model was populated with clinical inputs (transfusion rates, blood units transfused, hospital length of stay from a previously reported randomized trial comparing FCM vs usual care for managing IDA patients undergoing elective abdominal surgery. We applied a hospital perspective to all costs, excluding surgery-related costs in both treatment arms. One-way sensitivity analyses were undertaken to evaluate key drivers of cost analysis.Results: The average costs per case treated using FCM compared to usual care were €2,461 and €3,246, respectively, for resource expenses paid by hospital per case. This would suggest potential savings achieved with preoperative intravenous iron treatment per patient of €786 per case. A sensitivity analysis varying the key input parameters indicated the cost analysis is most sensitive to changes in the length of stay and the cost of hospitalization per day.Conclusion: Perioperative administration

  17. Uranium removal from drinking water by adsorption onto granular ferric hydroxide (GEH)

    International Nuclear Information System (INIS)

    Bahr, Carsten

    2012-01-01

    Uranium contamination of groundwater is encountered in many regions worldwide. Effective and simple removal technologies are required by waterworks faced with this problem, particularly in Germany which set a specification for maximum permissible uranium content in drinking water in November 2011. The present thesis examines the suitability of Granular Ferric Hydroxide (GEH) as a water treatment adsorbent for uranium removal. Adsorption isotherms generated in the studies showed that GEH is capable of adsorbing uranium, in fact achieving highest loading levels as compared to other oxide-based absorbents. Experimental data for uranium adsorption as a function of pH for the model systems U(VI) / H 2 O and U(VI) / H 2 O / CO 2 successfully fits the Surface Complexation Model using the adjusted parameter set for ferrihydrite. Test findings showed that adsorption capacity varies substantially depending on the water matrix processed and is significantly reduced when real ground water or drinking water is processed. The main parameters influencing adsorption capacity were found to be pH and the associated carbonate concentration, as well as the concentrations of calcium and phosphate and to a lesser extent of sulfate and humic substances. The reduced capacity is caused by adsorption competition and changes in chemical speciation of uranium brought about by the water matrix at hand. Both the kinetics and the dynamics of adsorption can be successfully described by the Homogeneous Surface Diffusion Model (HSDM). The characteristic transport coefficients for film diffusion and particle diffusion were determined using empirical correlations and lab testing. The comparatively slow kinetics of adsorption are caused by the rate-determining particle diffusion and lead to a relatively flat breakthrough curve. Experiments on small adsorber columns (RSSCT method) were used to simulate uranium breakthrough in GEH fixed-bed filters on a laboratory scale, permitting accurate prediction

  18. Redox Evolution in Magma Oceans Due to Ferric/Ferrous Iron Partitioning

    Science.gov (United States)

    Schaefer, L.; Elkins-Tanton, L. T.; Pahlevan, K.

    2017-12-01

    A long-standing puzzle in the evolution of the Earth is that while the present day upper mantle has an oxygen fugacity close to the QFM buffer, core formation during accretion would have occurred at much lower oxygen fugacities close to IW. We present a new model based on experimental evidence that normal solidification and differentiation processes in the terrestrial magma ocean may explain both core formation and the current oxygen fugacity of the mantle without resorting to a change in source material or process. A commonly made assumption is that ferric iron (Fe3+) is negligible at such low oxygen fugacities [1]. However, recent work on Fe3+/Fe2+ ratios in molten silicates [2-4] suggests that the Fe3+ content should increase at high pressure for a given oxygen fugacity. While disproportionation was not observed in these experiments, it may nonetheless be occurring in the melt at high pressure [5]. Therefore, there may be non-negligible amounts of Fe3+ formed through metal-silicate equilibration at high pressures within the magma ocean. Homogenization of the mantle and further partitioning of Fe2+/Fe3+ as the magma ocean crystallizes may explain the oxygen fugacity of the Earth's mantle without requiring additional oxidation mechanisms. We present here models using different parameterizations for the Fe2+/Fe3+ thermodynamic relationships in silicate melts to constrain the evolution of the redox state of the magma ocean as it crystallizes. The model begins with metal-silicate partitioning at high pressure to form the core and set the initial Fe3+ abundance. Combined with previous work on oxygen absorption by magma oceans due to escape of H from H2O [6], we show that the upper layers of solidifying magma oceans should be more oxidized than the lower mantle. This model also suggests that large terrestrial planets should have more oxidized mantles than small planets. From a redox perspective, no change in the composition of the Earth's accreting material needs to be

  19. Analysis of spatial diffusion of ferric ions in PVA-GTA gel dosimeters through magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Marrale, Maurizio [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); ATeN Center, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Collura, Giorgio [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Gallo, Salvatore, E-mail: salvatore.gallo05@unipa.it [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare (INFN) – Gruppo V Sezione di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Dipartimento di Fisica, Universitá di Milano, Via Giovanni Celoria 16, 20133 Milano (Italy); Nici, Stefania [Dipartimento di Fisica e Chimica, Universitá di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Tranchina, Luigi [ATeN Center, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Abbate, Boris Federico [U.O.C. Fisica Sanitaria, A.R.N.A.S., Ospedale Civico Palermo, Piazza Nicola Leotta 4, 90127 Palermo (Italy); Marineo, Sandra; Caracappa, Santo [Istituto Zooprofilattico Sperimentale della Sicilia (IZS), Via Gino Marinuzzi, 3, 90129 Palermo (Italy); and others

    2017-04-01

    Highlights: • Analysis of ferric ions diffusion throughout the gel matrix in PVA-GTA samples. • Measurements with preclinical 7T MRI scanner with spatial resolution of 200 μm. • Diffusion process is much slower for PVA-GTA gels than for agarose ones. - Abstract: This work focused on the analysis of the temporal diffusion of ferric ions through PVA-GTA gel dosimeters. PVA-GTA gel samples, partly exposed with 6 MV X-rays in order to create an initial steep gradient, were mapped using magnetic resonance imaging on a 7T MRI scanner for small animals. Multiple images of the gels were acquired over several hours after irradiation and were analyzed to quantitatively extract the signal profile. The spatial resolution achieved is 200 μm and this makes this technique particularly suitable for the analysis of steep gradients of ferric ion concentration. The results obtained with PVA-GTA gels were compared with those achieved with agarose gels, which is a standard dosimetric gel formulation. The analysis showed that the diffusion process is much slower (more than five times) for PVA-GTA gels than for agarose ones. Furthermore, it is noteworthy that the diffusion coefficient value obtained through MRI analysis is significantly consistent with that obtained in separate study Marini et al. (Submitted for publication) using a totally independent method such as spectrophotometry. This is a valuable result highlighting that the good dosimetric features of this gel matrix not only can be reproduced but also can be measured through independent experimental techniques based on different physical principles.

  20. Beta transmutations in apatites with ferric iron as an electron acceptor - implication for nuclear waste form development.

    Science.gov (United States)

    Yao, Ge; Zhang, Zelong; Wang, Jianwei

    2017-09-27

    Apatite-structured materials have been considered for the immobilization of a number of fission products from reprocessing nuclear fuel because of their chemical durability as well as compositional and structural flexibility. It is hypothesized that the effect of beta decay on the stability can be mitigated by introducing an appropriate electron acceptor at the neighboring sites in the structure. The decay series 137 Cs → 137 Ba and 90 Sr → 90 Y → 90 Zr were investigated using a spin-polarized DFT approach to test the hypothesis. Apatites with compositions of Ca 10 (PO 4 ) 6 F 2 and Ca 4 Y 6 (SiO 4 ) 6 F 2 were selected as model systems for the incorporation of radionuclides Cs and Sr, respectively. Ferric iron was introduced in the structure as an electron acceptor. Electron density of states, crystal and defect structures, and energies before and after beta decay were calculated. The calculated electron density of states suggests that the extra electron is localized at the ferric iron, which changes its oxidation state and becomes ferrous iron. The crystal and defect structures were analyzed based on the volume, lattice parameters, radial distribution functions, metal cation to coordinating oxygen distances, and the metaprism twist angle of the apatite crystal structure. The results show that there are minor changes in the crystal and defect structures of CsFeCa 8 (PO 4 ) 6 F 2 with Cs + and Fe 3+ substitutions undergoing the Cs → Ba transmutation, and of Ca 3 SrY 4 Fe 2 (SiO 4 ) 6 F 2 with Sr 2+ and Fe 3+ substitutions undergoing the Sr → Y → Zr transmutations. The last decay change, from Y 3+ → Zr 4+ , causes relatively larger changes in the local defect structure around Zr involving the coordination environment but the change is not significant to the crystal structure. The results on calculated cohesive energy suggest that the transmutations Cs + → Ba 2+ and Sr 2+ → Y 3+ → Zr 4+ in both apatite compositions are energetically favorable

  1. Filamentous hydrous ferric oxide biosignatures in a pipeline carrying acid mine drainage at Iron Mountain Mine, California

    Science.gov (United States)

    Williams, Amy J.; Alpers, Charles N.; Sumner, Dawn Y.; Campbell, Kate M.

    2017-01-01

    A pipeline carrying acidic mine effluent at Iron Mountain, CA, developed Fe(III)-rich precipitate caused by oxidation of Fe(II)aq. The native microbial community in the pipe included filamentous microbes. The pipe scale consisted of microbial filaments, and schwertmannite (ferric oxyhydroxysulfate, FOHS) mineral spheres and filaments. FOHS filaments contained central lumina with diameters similar to those of microbial filaments. FOHS filament geometry, the geochemical environment, and the presence of filamentous microbes suggest that FOHS filaments are mineralized microbial filaments. This formation of textural biosignatures provides the basis for a conceptual model for the development and preservation of biosignatures in other environments.

  2. Potential side effects of ammonium-ferric-hexacyano-ferrate application: enhanced radiostrontium transfer and free cyanide release

    International Nuclear Information System (INIS)

    Vandenhove, Hildegarde; Hees, May van; Vandecasteele, Christian

    2000-01-01

    The effect of the application of ammonium-ferric-hexacyano-ferrate (AFCF), effective in reducing soil-to-plant radiocaesium transfer, on radiostrontium transfer was tested for ryegrass grown under greenhouse conditions on sandy soil for 310 days. Identical radiostrontium transfer factors (9.4 kg kg -1 ) were obtained with 0 or 10 g AFCF m -2 applied. Amending AFCF to planted or uncovered sandy or loamy soils in quantities of up to 100 g AFCF m -2 did not result in detectable levels of free cyanide. Negative side effects of AFCF application to soil are hence unlikely

  3. A novel role of the ferric reductase Cfl1 in cell wall integrity, mitochondrial function, and invasion to host cells in Candida albicans.

    Science.gov (United States)

    Yu, Qilin; Dong, Yijie; Xu, Ning; Qian, Kefan; Chen, Yulu; Zhang, Biao; Xing, Laijun; Li, Mingchun

    2014-11-01

    Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  4. A case of osteomalacia due to deranged mineral balance caused by saccharated ferric oxide and short-bowel syndrome: A case report.

    Science.gov (United States)

    Nomoto, Hiroshi; Miyoshi, Hideaki; Nakamura, Akinobu; Nagai, So; Kitao, Naoyuki; Shimizu, Chikara; Atsumi, Tatsuya

    2017-09-01

    Saccharated ferric oxide has been shown to lead to elevation of fibroblast growth factor 23, hypophosphatemia, and, consequently, osteomalacia. Moreover, mineral imbalance is often observed in patients with short-bowel syndrome to some degree. A 62-year-old woman with short-bowel syndrome related with multiple resections of small intestines due to Crohn disease received regular intravenous administration of saccharated ferric oxide. Over the course of treatment, she was diagnosed with tetany, which was attributed to hypocalcemia. Additional assessments of the patient revealed not only hypocalcemia, but also hypophosphatemia, hypomagnesemia, osteomalacia, and a high concentration of fibroblast growth factor 23 (314 pg/mL). We diagnosed her with mineral imbalance-induced osteomalacia due to saccharated ferric oxide and short-bowel syndrome. Magnesium replacement therapy and discontinuation of saccharated ferric oxide alone. These treatments were able to normalize her serum mineral levels and increase her bone mineral density. This case suggests that adequate evaluation of serum minerals, including phosphate and magnesium, during saccharated ferric oxide administration may be necessary, especially in patients with short-bowel syndrome.

  5. [Stabilization of Cadmium Contaminated Soils by Ferric Ion Modified Attapulgite (Fe/ATP)--Characterizations and Stabilization Mechanism].

    Science.gov (United States)

    Rong, Yang; Li, Rong-bo; Zhou, Yong-li; Chen, Jing; Wang, Lin-ling; Lu, Xiao-hua

    2015-08-01

    Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium( Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2 and --OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (--OH bonds or O- sites) on ATP could react with Fe3+ giving Fe--O--Cd-- bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals.

  6. Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

    Science.gov (United States)

    Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

    2017-05-01

    Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

  7. Extraction of uranium from coarse ore and acid-curing and ferric sulphate-trickle leaching process

    International Nuclear Information System (INIS)

    Jin Suoqing

    1994-01-01

    On the basis of analysis of the problems in the technology of the traditional uranium hydrometallurgy and the limitations of thin layer leaching process (TLL), a new leaching system-acid-curing and ferric sulphate-trickle leaching (AFL) process (NGJ in Chinese) has developed for extraction of uranium from the coarse ore. The ferric sulphate solution was used for trickling the acid-cured uranium ore and the residual leaching reaction incomplete in TLL process can be improved in this process. And the AFL process has a wide applicability to China's uranium ores, being in competition with the traditional agitation leaching process for treating coarse ores. The uranium ore processing technology based on the AFL process will become one of the new basic technologies of uranium hydrometallurgy. A series of difficulties will be basically overcome associated with fine grinding because of its elimination in the presented process. Moreover, the situation of the present uranium hydrometallurgy can be also changed owing to without technological effluent discharge

  8. Reactions of Ferrous Coproheme Decarboxylase (HemQ) with O2 and H2O2 Yield Ferric Heme b.

    Science.gov (United States)

    Streit, Bennett R; Celis, Arianna I; Shisler, Krista; Rodgers, Kenton R; Lukat-Rodgers, Gudrun S; DuBois, Jennifer L

    2017-01-10

    A recently discovered pathway for the biosynthesis of heme b ends in an unusual reaction catalyzed by coproheme decarboxylase (HemQ), where the Fe(II)-containing coproheme acts as both substrate and cofactor. Because both O 2 and H 2 O 2 are available as cellular oxidants, pathways for the reaction involving either can be proposed. Analysis of reaction kinetics and products showed that, under aerobic conditions, the ferrous coproheme-decarboxylase complex is rapidly and selectively oxidized by O 2 to the ferric state. The subsequent second-order reaction between the ferric complex and H 2 O 2 is slow, pH-dependent, and further decelerated by D 2 O 2 (average kinetic isotope effect of 2.2). The observation of rapid reactivity with peracetic acid suggested the possible involvement of Compound I (ferryl porphyrin cation radical), consistent with coproheme and harderoheme reduction potentials in the range of heme proteins that heterolytically cleave H 2 O 2 . Resonance Raman spectroscopy nonetheless indicated a remarkably weak Fe-His interaction; how the active site structure may support heterolytic H 2 O 2 cleavage is therefore unclear. From a cellular perspective, the use of H 2 O 2 as an oxidant in a catalase-positive organism is intriguing, as is the unusual generation of heme b in the Fe(III) rather than Fe(II) state as the end product of heme synthesis.

  9. Removal of Sb(III and Sb(V by Ferric Chloride Coagulation: Implications of Fe Solubility

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Inam

    2018-04-01

    Full Text Available Coagulation and precipitation appear to be the most efficient and economical methods for the removal of antimony from aqueous solution. In this study, antimony removal from synthetic water and Fe solubility with ferric chloride (FC coagulation has been investigated. The effects of pH, FC dosage, initial antimony loading and mixed Sb(III, Sb(V proportions on Fe solubility and antimony removal were studied. The results showed that the Sb(III removal efficiency increased with the increase of solution pH particularly due to an increase in Fe precipitation. The Sb(V removal was influenced by the solution pH due to a change in Fe solubility. However, the Fe solubility was only impaired by the Sb(III species at optimum pH 7. The removal efficiencies of both Sb species were enhanced with an increase in FC dose. The quantitative analysis of the isotherm study revealed the strong adsorption potential of Sb(III on Fe precipitates as compared to Sb(V. Furthermore, the removal behavior of antimony was inhibited in mixed proportion with high Sb(V fraction. In conclusion, this study contributes to better understanding the fate of Sb species, their mobilities, and comparative removal behavior, with implications for Fe solubility using ferric chloride in different aqueous environments.

  10. Ferric Iron Precipitation in the Nagahama Bay, Satsuma Iwo-Jima Island, Kagoshima

    Science.gov (United States)

    Nagata, T.; Kiyokawa, S.; Ikehara, M.; Oguri, K.; Goto, S.; Ito, T.; Yamaguchi, K. E.; Ueshiba, T.

    2010-12-01

    Satsuma-Iwojima island is active volcanic island and 6 x 3 km in size, located 38km south of Kyushu island, Japan. The reddish brown water along the coast of the Iwo-dake volcano at the center of the island formed by neutralization through mixing of shallow hydrothermal fluid and seawater. The reddish brown water contains reddish ferrihydrite (Fe3+) that is derived from oxidation of Fe2+ from acidic hot spring (Shikaura and Tazaki, 2001). In the Nagahama Bay with its opening to the south, red-colored Fe-rich water is affected by tidal current, but sedimentation of the ferric hydroxide is confirmed to occur in the ocean bottom (Ninomiya and Kiyokawa, 2009). Here we focus other lines of evidence from long term observations and meteorological records as important factor to form thick iron rich sediments. Meteorological and stationary observations: We used weather record in the Satsuma Iwo-jima and cross-checked with stationary observations, which enabled us to observe color changes of the surface of Nagahama Bay. It was made clear that north wind condition in the Nagahama Bay resulted in changes of the color of its surface, from red to green, by intrusion of ocean water coming from outside. Long term temperature monitoring: The temperature of seawater in the Nagahama Bay fluctuated synchronically with the air temperature. But that of hot spring water rather remained constant regardless of the seasonal change. We observed that seawater temperature in the Nagahama Bay is low at high tide and high at low tide, and the rage of temperature change is maximum at the spring tide and minimum at the neap tide. In other words, the amount of discharge of hot spring and that of seawater inflow vary inversely. Core sample: In the Nagahama Bay, iron rich sediments that is more than 1 m thick were identified. The core sample shows lithology as following; upper part, 10-20cm thick, formed loose Fe-rich deposit, lower portion formed alteration of weakly consolidated Fe-rich orange

  11. Energy cascades, excited state dynamics, and photochemistry in cob(III)alamins and ferric porphyrins.

    Science.gov (United States)

    Rury, Aaron S; Wiley, Theodore E; Sension, Roseanne J

    2015-03-17

    Porphyrins and the related chlorins and corrins contain a cyclic tetrapyrrole with the ability to coordinate an active metal center and to perform a variety of functions exploiting the oxidation state, reactivity, and axial ligation of the metal center. These compounds are used in optically activated applications ranging from light harvesting and energy conversion to medical therapeutics and photodynamic therapy to molecular electronics, spintronics, optoelectronic thin films, and optomagnetics. Cobalt containing corrin rings extend the range of applications through photolytic cleavage of a unique axial carbon-cobalt bond, permitting spatiotemporal control of drug delivery. The photochemistry and photophysics of cyclic tetrapyrroles are controlled by electronic relaxation dynamics including internal conversion and intersystem crossing. Typically the electronic excitation cascades through ring centered ππ* states, ligand to metal charge transfer (LMCT) states, metal to ligand charge transfer (MLCT) states, and metal centered states. Ultrafast transient absorption spectroscopy provides a powerful tool for the investigation of the electronic state dynamics in metal containing tetrapyrroles. The UV-visible spectrum is sensitive to the oxidation state, electronic configuration, spin state, and axial ligation of the central metal atom. Ultrashort broadband white light probes spanning the range from 270 to 800 nm, combined with tunable excitation pulses, permit the detailed unravelling of the time scales involved in the electronic energy cascade. State-of-the-art theoretical calculations provide additional insight required for precise assignment of the states. In this Account, we focus on recent ultrafast transient absorption studies of ferric porphyrins and corrin containing cob(III)alamins elucidating the electronic states responsible for ultrafast energy cascades, excited state dynamics, and the resulting photoreactivity or photostability of these compounds. Iron

  12. EPR study of the low-spin state of Ru.sup.3+./sup. in the YAl.sub.3./sub.(BO.sub.4./sub.).sub.3./sub. and EuAl.sub.3./sub.(BO.sub.3./sub.).sub.4./sub. aluminum borates

    Czech Academy of Sciences Publication Activity Database

    Prokhorov, Andriy; Chernush, L.F.; Dyakonov, V.P.; Szymczak, H.; Prokhorov, A.D.

    2016-01-01

    Roč. 420, Dec (2016), s. 285-289 ISSN 0304-8853 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088 Institutional support: RVO:68378271 Keywords : EPR spectra * rare-earth * aluminum borates * spin Hamiltonian parameters * superposition model * low-spin state Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.630, year: 2016

  13. Performance evaluation of ALCAN-AASF50-ferric coated activated alumina and granular ferric hydroxide (GFH) for arsenic removal in the presence of competitive ions in an active well :Kirtland field trial - initial studies.

    Energy Technology Data Exchange (ETDEWEB)

    Neidel, Linnah L.; Krumhansl, James Lee; Siegel, Malcolm Dean; Khandaker, Nadim Reza

    2006-01-01

    This report documents a field trial program carried out at Well No.15 located at Kirtland Air Force Base, Albuquerque, New Mexico, to evaluate the performance of two relatively new arsenic removal media, ALCAN-AASF50 (ferric coated activated alumina) and granular ferric hydroxide (US Filter-GFH). The field trial program showed that both media were able to remove arsenate and meet the new total arsenic maximum contaminant level (MCL) in drinking water of 10 {micro}g/L. The arsenate removal capacity was defined at a breakthrough effluent concentration of 5 {micro}g/L arsenic (50% of the arsenic MCL of 10 {micro}g/L). At an influent pH of 8.1 {+-} 0.4, the arsenate removal capacity of AASF50 was 33.5 mg As(V)/L of dry media (29.9 {micro}g As(V)/g of media on a dry basis). At an influent pH of 7.2 {+-} 0.3, the arsenate removal capacity of GFH was 155 mg As(V)/L of wet media (286 {micro}g As(V)/g of media on a dry basis). Silicate, fluoride, and bicarbonate ions are removed by ALCAN AASF50. Chloride, nitrate, and sulfate ions were not removed by AASF50. The GFH media also removed silicate and bicarbonate ions; however, it did not remove fluoride, chloride, nitrate, and sulfate ions. Differences in the media performance partly reflect the variations in the feed-water pH between the 2 tests. Both the exhausted AASF50 and GFH media passed the Toxicity Characteristic Leaching Procedure (TCLP) test with respect to arsenic and therefore could be disposed as nonhazardous waste.

  14. An investigation of magnox sludge and alumino-ferric floc waste simulate, immobilised by a cementitious matrix

    International Nuclear Information System (INIS)

    Halley, D.G.

    1983-09-01

    Magnox sludge and alumino ferric floc simulates, prepared using non-radioactive tracers were immobilised by a cementitious system. Formulation design aimed at optimising pollutant leaching with permeability and compressive strength as secondary considerations. The behaviour of the products under accelerated weathering conditions was investigated. The study was divided into two parts: Formulation design in Phase I and the systematic testing of the optimum formulations under freeze-thaw, and hydration -dehydration conditions in Phase 2. Analytical method development for leachate analysis continued through both Phases. The Barnwood method of leach testing was used. The immobilised waste had good physical properties (i.e. high strength and low permeability) and a significant improvement was achieved during the course of the work in the leach rates of the tracers, particularly of caesium and strontium. (author)

  15. Physico-chemical properties of the new generation IV iron preparations ferumoxytol, iron isomaltoside 1000 and ferric carboxymaltose.

    Science.gov (United States)

    Neiser, Susann; Rentsch, Daniel; Dippon, Urs; Kappler, Andreas; Weidler, Peter G; Göttlicher, Jörg; Steininger, Ralph; Wilhelm, Maria; Braitsch, Michaela; Funk, Felix; Philipp, Erik; Burckhardt, Susanna

    2015-08-01

    The advantage of the new generation IV iron preparations ferric carboxymaltose (FCM), ferumoxytol (FMX), and iron isomaltoside 1000 (IIM) is that they can be administered in relatively high doses in a short period of time. We investigated the physico-chemical properties of these preparations and compared them with those of the older preparations iron sucrose (IS), sodium ferric gluconate (SFG), and low molecular weight iron dextran (LMWID). Mössbauer spectroscopy, X-ray diffraction, and Fe K-edge X-ray absorption near edge structure spectroscopy indicated akaganeite structures (β-FeOOH) for the cores of FCM, IIM and IS, and a maghemite (γ-Fe2O3) structure for that of FMX. Nuclear magnetic resonance studies confirmed the structure of the carbohydrate of FMX as a reduced, carboxymethylated, low molecular weight dextran, and that of IIM as a reduced Dextran 1000. Polarography yielded significantly different fingerprints of the investigated compounds. Reductive degradation kinetics of FMX was faster than that of FCM and IIM, which is in contrast to the high stability of FMX towards acid degradation. The labile iron content, i.e. the amount of iron that is only weakly bound in the polynuclear iron core, was assessed by a qualitative test that confirmed decreasing labile iron contents in the order SFG ≈ IS > LMWID ≥ FMX ≈ IIM ≈ FCM. The presented data are a step forward in the characterization of these non-biological complex drugs, which is a prerequisite to understand their cellular uptake mechanisms and the relationship between the structure and physiological safety as well as efficacy of these complexes.

  16. Induction of hepatic and renal metallothionein synthesis by ferric nitrilotriacetate in mice: the role of MT as an antioxidant

    International Nuclear Information System (INIS)

    Min, Kyong-Son; Morishita, Fumio; Tetsuchikawahara, Noriko; Onosaka, Satomi

    2005-01-01

    Metallothionein (MT) demonstrates strong antioxidant properties, yet the physiological relevance of its antioxidant action is not clear. Injection of mice with ferric nitrilotriacetate (Fe-NTA) caused a dose-dependent increase in hepatic and renal MT. Fe-NTA caused a greater increase in hepatic and renal MT concentration (2.5- and 4-fold) compared with FeCl 3 at the same dose of ferric ion. MT mRNA levels were markedly elevated in both of tissues. Thiobarbituric acid (TBA) values in both tissues reached a maximum after 2-4 h. The MT concentrations were significantly increased after 2-4 h in liver and after 8-16 h in kidneys. Plasma concentrations of cytokines such as IL-6 and TNFα were elevated by 4 h; IL-6 levels were 24 times higher after Fe-NTA than that after injection of FeCl 3 . Pretreatment of mice with ZnSO 4 attenuated nephrotoxicity induced by Fe-NTA after 2 h, but was not effective 4 h after injection. After a Fe-NTA injection, a loss of Cd-binding properties of preinduced MT was observed only in kidneys of Zn-pretreated mice but not in liver. Treatment with BSO, glutathione (GSH) depletor, intensified a loss of its Cd-binding properties after a Fe-NTA injection. These results indicate that induction of MT synthesis may result from reactive oxygen species (ROS) generated by Fe-NTA, and MT may act in vivo as a complementary antioxidant

  17. Groundwater arsenic removal by coagulation using ferric(III) sulfate and polyferric sulfate: A comparative and mechanistic study.

    Science.gov (United States)

    Cui, Jinli; Jing, Chuanyong; Che, Dongsheng; Zhang, Jianfeng; Duan, Shuxuan

    2015-06-01

    Elevated arsenic (As) in groundwater poses a great threat to human health. Coagulation using mono- and poly-Fe salts is becoming one of the most cost-effective processes for groundwater As removal. However, a limitation comes from insufficient understanding of the As removal mechanism from groundwater matrices in the coagulation process, which is critical for groundwater treatment and residual solid disposal. Here, we overcame this hurdle by utilizing microscopic techniques to explore molecular As surface complexes on the freshly formed Fe flocs and compared ferric(III) sulfate (FS) and polyferric sulfate (PFS) performance, and finally provided a practical solution in As-geogenic areas. FS and PFS exhibited a similar As removal efficiency in coagulation and coagulation/filtration in a two-bucket system using 5mg/L Ca(ClO)2. By using the two-bucket system combining coagulation and sand filtration, 500 L of As-safe water (<10 μg/L) was achieved during five treatment cycles by washing the sand layer after each cycle. Fe k-edge X-ray absorption near-edge structure (XANES) and As k-edge extended X-ray absorption fine structure (EXAFS) analysis of the solid residue indicated that As formed a bidentate binuclear complex on ferrihydrite, with no observation of scorodite or poorly-crystalline ferric arsenate. Such a stable surface complex is beneficial for As immobilization in the solid residue, as confirmed by the achievement of much lower leachate As (0.9 μg/L-0.487 mg/L) than the US EPA regulatory limit (5 mg/L). Finally, PFS is superior to FS because of its lower dose, much lower solid residue, and lower cost for As-safe drinking water. Copyright © 2015. Published by Elsevier B.V.

  18. Highly selective and sensitive fluorogenic ferric probes based on aggregation-enhanced emission with - SiMe3 substituted polybenzene

    Science.gov (United States)

    Wang, Xuefeng; Wang, Hua; Jiang, Qin; Lee, Yong-Ill; Feng, Shengyu; Liu, Hong-Guo

    2018-01-01

    In this study, thiophene was linked to polybenzene to generate novel fluorescent probes, namely 3,4-diphenyl-2,5-di(2-thienyl)phenyl-trimethylsilane (DPTB-TMS) with a - SiMe3 substituent and 3,4-diphenyl-2,5-di(2-thienyl)phenyl (DPTB) without the - SiMe3 substituent, respectively. Both of the two compounds exhibit aggregation-enhanced emission (AEE) properties in tetrahydrofuran/water mixtures due to restricted intramolecular rotation of the peripheral groups, which make the two compounds good candidates for the detection of Fe3 + ions in aqueous-based solutions. The fluorescence intensity of the two compounds decreases immediately and obviously upon addition of a trace amount of Fe3 +, and decreases continuously as the amount of Fe3 + increases. The fluorescence was quenched to 92% of its initial intensity when the amount of Fe3 + ions reached 6 μmol for DPTB-TMS and to 80% for DPTB in the systems, indicating that the compound with the - SiMe3 group is a more effective probe. The detection limit was found to be 1.17 μM (65 ppb). The detection mechanism is proposed to be static quenching. DPTB-TMS is highly efficient for the detection of ferric ions even in the presence of other metal ions. In addition, the method is also successfully applied to the detection of ferric ions in water, blood serum, or solid films. This indicates that these polybenzene compounds can be applied as low-cost, high selectivity, and high efficiency Fe3 + probes in water or in clinical applications.

  19. Theory favors a stepwise mechanism of porphyrin degradation by a ferric hydroperoxide model of the active species of heme oxygenase.

    Science.gov (United States)

    Kumar, Devesh; de Visser, Samuël P; Shaik, Sason

    2005-06-08

    The report uses density functional theory to address the mechanism of heme degradation by the enzyme heme oxygenase (HO) using a model ferric hydroperoxide complex. HO is known to trap heme molecules and degrade them to maintain iron homeostasis in the biosystem. The degradation is initiated by complexation of the heme, then formation of the iron-hydroperoxo species, which subsequently oxidizes the meso position of the porphyrin by hydroxylation, thereby enabling eventually the cleavage of the porphyrin ring. Kinetic isotope effect studies indicate that the mechanism is assisted by general acid catalysis, via a chain of water molecules, and that all the events occur in concert. However, previous theoretical treatments indicated that the concerted mechanism has a high barrier, much higher than an alternative mechanism that is initiated by O-O bond homolysis of iron-hydroperoxide. The present contribution studies the stepwise and concerted acid-catalyzed mechanisms using H(3)O(+)(H(2)O)(n)(), n = 0-2. The effect of the acid strength is tested using the H(4)N(+)(H(2)O)(2) cluster and a fully protonated ferric hydroperoxide. All the calculations show that a stepwise mechanism that involves proton relay and O-O homolysis, in the rate-determining step, has a much lower barrier (>10 kcal/mol) than the corresponding fully concerted mechanism. The best fit of the calculated solvent kinetic isotope effect, to the experimental data, is obtained for the H(3)O(+)(H(2)O)(2) cluster. The calculated alpha-deuterium secondary kinetic isotope effect is inverse (0.95-0.98), but much less so than the experimental value (0.7). Possible reasons for this quantitative difference are discussed. Some probes are suggested that may enable experiment to distinguish the stepwise from the concerted mechanism.

  20. Bioavailability and the mechanisms of intestinal absorption of iron from ferrous ascorbate and ferric polymaltose in experimental animals

    International Nuclear Information System (INIS)

    Johnson, G.; Jacobs, P.

    1990-01-01

    The comparative bioavailability from matching quantities of iron in the form of ferrous ascorbate or ferric polymaltose was defined in rats. Studies were carried out in the intact animals under basal conditions and also when requirements for this metal were either increased or decreased by manipulating stores or erythropoietic activity. No significant difference was found in the total quantity of iron absorbed from either salt or complex under any of these circumstances, suggesting that the mucosal mechanism regulating the overall process was common to both. However, the rate of transfer from the lumen into portal blood was distinctive, reaching a maximum with salt at 30 min compared to 24 h for the complex. To explore the possibility that iron from the two sources was initially handled by different subcellular pathways, the radiolabeled compounds were instilled into loops of bowel that had been isolated between ligatures in vivo. Enterocytes were harvested and fractionated, and incorporation into ferritin and transferrin was determined using RIA. From salt, iron appeared rapidly in duodenal but not ileal ferritin, whereas mucosal transferrin increased under conditions of stimulated absorption, suggesting that this protein may act as a shuttle for the metal. In contrast, iron from polymaltose showed a cumulative incorporation into duodenal ferritin over time that correlated with iron absorption, defined by the appearance of radiolabel in the serum and in the carcass; a similar pattern was demonstrable in ileal mucosal cells. Conversely, binding of iron to transferrin was minimal. No iron polymaltose was found within the mucosal cells. It is suggested that the low rate of iron transfer from this ferric complex may reflect its extracellular breakdown in the lumen of the gastrointestinal tract

  1. Formation, aggregation and reactivity of amorphous ferric oxyhydroxides on dissociation of Fe(III)-organic complexes in dilute aqueous suspensions

    Science.gov (United States)

    Bligh, Mark W.; Waite, T. David

    2010-10-01

    While chemical reactions that take place at the surface of amorphous ferric oxides (AFO) are known to be important in aquatic systems, incorporation of these reactions into kinetic models is hindered by a lack of ability to reliably quantify the reactivity of the surface and the changes in reactivity that occur over time. Long term decreases in the reactivity of iron oxides may be considered to result from changes in the molecular structure of the solid, however, over shorter time scales where substantial aggregation may occur, the mechanisms of reactivity loss are less clear. Precipitation of AFO may be described as a combination of homogeneous and heterogeneous reactions, however, despite its potentially significant role, the latter reaction is usually neglected in kinetic models of aquatic processes. Here, we investigate the role of AFO in scavenging dissolved inorganic ferric (Fe(III)) species (Fe') via the heterogeneous precipitation reaction during the net dissociation of organically complexed Fe(III) in seawater. Using sulfosalicylic acid (SSA) as a model ligand, AFO was shown to play a significant role in inducing the net dissociation of the Fe-SSA complexes with equations describing both the heterogeneous precipitation reaction and the aging of AFO being required to adequately describe the experimental data. An aggregation based mechanism provided a good description of AFO aging over the short time scale of the experiments. The behaviour of AFO described here has implications for the bioavailability of iron in natural systems as a result of reactions involving AFO which are recognised to occur over time scales of minutes, including adsorption of Fe' and AFO dissolution, precipitation and ageing.

  2. Studies on the preparation of ferric-hydroxide macro aggregate and hydroxyapatite particles labelled with Sm-153, Ho-166 and/or Dy-165 for radiation synovectomy

    International Nuclear Information System (INIS)

    Le Van So; Pham Ngoc Dien; Truong Hong Nghia; Nguyen Thi Thu; Nguyen Cong Duc; Vo Thji Cam Hoa; Bui Van Cuong

    2004-01-01

    The modified methods for the preparation of Hydroxyapatite particle (HA) and Ferric Hydroxide Macro Aggregated (FHMA of high stability and uniformity in particle size and of good geometrical shape suitable for production of radiolabeled carrier for radiation synovectomy purpose were developed. 165 Dy, 166 Ho and/or 153 Sm labeled HA and FHMA were produced using a simple labelling method. (author)

  3. Dual fortification of salt with iodine and iron: a randomized, double-blind, controlled trial of micronized ferric pyrophosphate and encapsulated ferrous fumarate in southern India

    NARCIS (Netherlands)

    Andersson, M.; Thankachan, P.; Muthayya, S.; Goud, R.B.; Kurpad, A.V.; Hurrell, R.F.

    2008-01-01

    Background:Dual fortification of salt with iodine and iron could be a sustainable approach to combating iodine and iron deficiencies. Objective:We compared the efficacy of dual-fortified salt (DFS) made by using 2 proposed contrasting formulas-one fortifying with iron as micronized ground ferric

  4. Optical properties and electronic transitions of zinc oxide, ferric oxide, cerium oxide, and samarium oxide in the ultraviolet and extreme ultraviolet

    DEFF Research Database (Denmark)

    Pauly, N; Yubero, F; Espinós, J P

    2017-01-01

    Optical properties and electronic transitions of four oxides, namely zinc oxide, ferric oxide, cerium oxide, and samarium oxide, are determined in the ultraviolet and extreme ultraviolet by reflection electron energy loss spectroscopy using primary electron energies in the range 0.3-2.0 ke...

  5. Formation, reactivity and aging of amorphous ferric oxides in the presence of model and membrane bioreactor derived organics.

    Science.gov (United States)

    Bligh, Mark W; Maheshwari, Pradeep; David Waite, T

    2017-11-01

    Iron salts are routinely dosed in wastewater treatment as a means of achieving effluent phosphorous concentration goals. The iron oxides that result from addition of iron salts partake in various reactions, including reductive dissolution and phosphate adsorption. The reactivity of these oxides is controlled by the conditions of formation and the processes, such as aggregation, that lead to a reduction in accessible surface sites following formation. The presence of organic compounds is expected to significantly impact these processes in a number of ways. In this study, amorphous ferric oxide (AFO) reactivity and aging was investigated following the addition of ferric iron (Fe(III)) to three solution systems: two synthetic buffered systems, either containing no organic or containing alginate, and a supernatant system containing soluble microbial products (SMPs) sourced from a membrane bioreactor (MBR). Reactivity of the Fe(III) phases in these systems at various times (1-60 min) following Fe(III) addition was quantified by determining the rate constants for ascorbate-mediated reductive dissolution over short (5 min) and long (60 min) dissolution periods and for a range (0.5-10 mM) of ascorbate concentrations. AFO particle size was monitored using dynamic light scattering during the aging and dissolution periods. In the presence of alginate, AFO particles appeared to be stabilized against aggregation. However, aging in the alginate system was remarkably similar to the inorganic system where aging is associated with aggregation. An aging mechanism involving restructuring within the alginate-AFO assemblage was proposed. In the presence of SMPs, a greater diversity of Fe(III) phases was evident with both a small labile pool of organically complexed Fe(III) and a polydisperse population of stabilized AFO particles present. The prevalence of low molecular weight organic molecules facilitated stabilization of the Fe(III) oxyhydroxides formed but subsequent aging

  6. The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on adsorption of Cr (VI) from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Lili [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Ma Wei, E-mail: chmawv@yahoo.com [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Han Mei; Cheng Zihong [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China)

    2011-02-15

    Research highlights: {yields} The reconstruction processes of CH-Mg/Al and CH-Mg/Al/Fe were fast and efficient, but the adsorption of Cr (VI) on CH-Mg/Al/Fe reached equilibrium faster. {yields} The removal mechanism involved not only intercalation but also adsorption on external surface of the layers and interlayer anion exchange. {yields} The existence of Fe3{sup +} in Mg/Al calcined hydrotalcite led to the interlayer anion exchange more difficult and it is affected equilibrium amount of Cr (VI) adsorption. - Abstract: The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on removal of Cr (VI) from aqueous solution was studied from aspects of structure characteristics, adsorption properties and mechanism discussions. The calcined hydrotalcites (CH-Mg/Al and CH-Mg/Al/Fe) were obtained by thermal decomposition of their corresponding precursors and characterized by XRD, TEM, pH{sub PZC} and FTIR. The adsorption properties were studied as a function of pH, initial Cr (VI) concentration and contact time. The results showed that the nature of adsorption is endothermic and spontaneous for both CH-Mg/Al and CH-Mg/Al/Fe, but the thermodynamic parameter value changes revealed the addition of Fe{sup 3+} is disadvantage to adsorption process and the theoretical saturated adsorption capacity decreased by approximately 10.2 mg/g at tested temperatures. The removal mechanism involved not only intercalation but adsorption on external surface of the layers and interlayer anion exchange for both CH-Mg/Al and CH-Mg/Al/Fe. Furthermore, the results also indicated that intercalation accounts for a large proportion during removal process whatever for CH-Mg/Al, or for CH-Mg/Al/Fe. Additionally, the replacement of Al{sup 3+} by Fe{sup 3+} in CH-Mg/Al led to the interlayer anion exchange more difficult. On the basis of the results, it is concluded that the existence of ferric iron in calcined Mg/Al hydrotalcite is unfavorable to removal of Cr (VI) from aqueous solution.

  7. Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.

    Science.gov (United States)

    Liu, Yulei; Wang, Lu; Wang, Xianshi; Huang, Zhuangsong; Xu, Chengbiao; Yang, Tao; Zhao, Xiaodan; Qi, Jingyao; Ma, Jun

    2017-11-01

    Thallium (Tl) is highly toxic to mammals and relevant pollution cases are increasing world-widely. Convenient and efficient method for the removal of trace Tl from contaminated source water is imperative. Here, the removal of trace Tl by K 2 FeO 4 [Fe(VI)] was investigated for the first time, with the exploration of reaction mechanisms. Six different types of water treatment agents (powdered activated carbon, Al 2 (SO 4 ) 3 , FeCl 3 , δ-MnO 2 , MnO 2 nano-particles, and K 2 FeO 4 ) were used for the removal of Tl in spiked river water, and K 2 FeO 4 showed excellent removal performance. Over 92% of Tl (1 μg/L) was removed within 5 min by applying 2.5 mg/L of K 2 FeO 4 (pH 7.0, 20 °C). XPS analysis revealed that in the reaction of Tl(I) with K 2 FeO 4 , Tl(I) was oxidized to Tl(III), and removed by the K 2 FeO 4 reduced ferric particles. The removal of Tl by in situ formed and ex situ formed ferric particle was examined respectively, and the results revealed that the removal of trace Tl could be attributed to the combination of adsorption and coprecipitation processes. The hydrodynamic size of the reduced particle from K 2 FeO 4 ranged from 10 nm to 100 nm, and its surface was negatively charged under neutral pH condition. These factors were conducive for the efficient removal of Tl by K 2 FeO 4 . The effects of solution pH, coexisting ions (Na + , Ca 2+ , and HCO 3 - ), humic acid, solution temperature, and reductive environment on the removal and desorption of Tl were investigated, and the elimination of Tl in polluted river water and reservoir water was performed. These results suggest that K 2 FeO 4 could be an efficient and convenient agent on trace Tl removal. Copyright © 2017. Published by Elsevier Ltd.

  8. Superiority of ferric chloride as coagulant over alum and ferrous sulphate at controlled pH and cost comparison of these coagulant

    International Nuclear Information System (INIS)

    Irfan, M.

    2008-01-01

    This study was conducted by author as a member of Specialty Chemical Division of Sitara Chemical Industries which is the largest chlor -alkali manufacturing industry in Pakistan. Sitara is also producing FeCl/sub 3/ as a byproduct to consume its additional quantity of chlorine produced during electrolysis of brine solution for caustic soda preparation. Most of the industries are using Alum along with other polymers for treatment of effluent waste water. Treatment system is based on sand bed filters. For coagulation of unwanted materials present in the water, Alum is being used with Anionic Polymer (Accofloc-A2125) as flocculent. But the ferric chloride is not only functions as a reactants to remove water impurities but it also functions as a both coagulant and a Flocculent. This study was conducted for finding best alternative chemicals to improve treated water quality. For this purpose Ferric Chloride (FeCl/sub 3/) is used as best alternative of alum for better removal of turbidity, heavy metals and micro organisms to eradicate above said problems and for better removal of turbidity, heavy metals and micro, organisms to eradicate health problems. As per lab scale results quality of treated water with Ferric Chloride (FeCl/sub 3/) proved better than that of Alum. The main objective of this research is to investigate the efficiency of coagulation and flocculation processes for removing suspended solids, colour and COD which present in significant quantity. Three types of coagulants were examined using standard jar test apparatus, i.e., aluminum sulphate (alum), ferric chloride (FeCl/sub 3/) and ferrous sulphate (FeSO/sub 4/). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were examined. At 300 rpm of rapid mixing and 50 rpm of slow mixing and 60 minutes settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl/sub 3/ was found to be superior compared with other

  9. SEQUENTIAL EXTRACTION OF PHOSPHORUS BY MEHLICH-1 AND ION EXCHANGE RESIN FROM B HORIZONS OF FERRIC AND PERFERRIC LATOSOLS (OXISOLS

    Directory of Open Access Journals (Sweden)

    Danilo de Lima Camêlo

    2015-08-01

    Full Text Available In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1 and Ion Exchange Resin (IER, from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed with M-1 and IER from samples of B horizons (depth between 0.8 and 1.0 m. Total contents of Ca, P, Fe, Al, and Ti were determined after digestion with nitric, hydrofluoric and perchloric acids. The effects of sequential P extractions on Fe oxides were also evaluated from the analyses of dithionite-citrate-bicarbonate and ammonium acid oxalate. The high similarity between contents of P accumulated after sequential extractions with M-1 and IER in soils developed on tuffite indicated a predominance of P-Ca. Higher contents of P after a single IER extraction show greater efficiency in P removal from highly weathered soils, as from the Latosols studied here. The P contents also show the high sensitivity of extractant M-1 in highly buffered soils. Furthermore, a single extraction with extractant M-1 or IER is not sufficient to estimate the amount of labile P in these soils.

  10. An experimental study on accelerated fouling of aluminum oxide and ferric oxide particles in internally enhanced tubes

    Energy Technology Data Exchange (ETDEWEB)

    Abedin, Mohammad Zoynal; Kim, Nae Hyun [School of Mechanical System Engineering, Incheon National University, Incheon (Korea, Republic of)

    2016-12-15

    This paper describes the results of accelerated particulate fouling tests performed on three enhanced tubes and a plain tube. The tests were performed using ferric oxide and aluminum oxide as foulant materials. Three enhanced tubes included 25 start, 10 start helically ribbed tubes and a ripple tube. Effects of the water velocity (0.9 to 1.8 m/s) and foulant concentration (750 to 2500 ppm) were investigated. At 750 ppm, the enhanced tubes fouled almost the same as the plain tube for the entire velocity range tested (0.9 to 1.8 m/s). The enhanced tube fouled faster than the plain tube for cases of high concentration combined with low velocities. Of the three enhanced tubes, the 25 start helically ribbed tube fouled faster than the ripple and the 10 start helically ribbed tubes. One thing to be noted is that the fouling concentrations used in the tests are significantly higher than would be expected in commercial heat exchangers. Also, the velocity range investigated is lower than would be expected in heat exchanger operation.

  11. Harmful algal bloom removal and eutrophic water remediation by commercial nontoxic polyamine-co-polymeric ferric sulfate-modified soils.

    Science.gov (United States)

    Dai, Guofei; Zhong, Jiayou; Song, Lirong; Guo, Chunjing; Gan, Nanqin; Wu, Zhenbin

    2015-07-01

    Harmful algal bloom has posed great threat to drinking water safety worldwide. In this study, soils were combined with commercial nontoxic polyamine poly(epichlorohydrin-dimethylamine) (PN) and polymeric ferric sulfate (PFS) to obtain PN-PFS soils for Microcystis removal and eutrophic water remediation under static laboratory conditions. High pH and temperature in water could enhance the function of PN-PFS soil. Algal removal efficiency increased as soil particle size decreased or modified soil dose increased. Other pollutants or chemicals (such as C, P, and organic matter) in eutrophic water could participate and promote algal removal by PN-PFS soil; these pollutants were also flocculated. During PN-PFS soil application in blooming field samples, the removal efficiency of blooming Microcystis cells exceeded 99 %, the cyanotoxin microcystins reduced by 57 %. Water parameters (as TP, TN, SS, and SPC) decreased by about 90 %. CODMn, PO4-P, and NH4-N also sharply decreased by >45 %. DO and ORP in water improved. Netting and bridging effects through electrostatic attraction and complexation reaction could be the two key mechanisms of Microcystis flocculation and pollutant purification. Considering the low cost of PN-PFS soil and its nontoxic effect on the environment, we proposed that this soil combination could be applied to remove cyanobacterial bloom and remediate eutrophic water in fields.

  12. Effects of ferric iron reduction and regeneration on nitrous oxide and methane emissions in a rice soil.

    Science.gov (United States)

    Huang, Bin; Yu, Kewei; Gambrell, Robert P

    2009-01-01

    A laboratory soil slurry experiment and an outdoor pot experiment were conducted to study effects of ferric iron (Fe(III)) reduction and regeneration on nitrous oxide (N(2)O) and methane (CH(4)) emissions in a rice (Oryza sativa L.) soil. The anoxic slurry experiment showed that enhancing microbial Fe(III) reduction by ferrihydrite amendment (40 mol Fe g(-1)) transitionally stimulated N(2)O production and lowered CH(4) production by 16% during an initial 33-day incubation. Increased regeneration of Fe(III) through a 4-day aeration period in the Fe-amended slurry compared to the control slurry reduced CH(4) emission by 30% in the subsequent 15-day anaerobic incubation. The pot experiment showed that ferrihydrite amendment (63 micromol Fe g(-1)) stimulated N(2)O fluxes in the days following flooding. The Fe amendment suppression on CH(4) emission was obscured in the early season but became significant upon reflooding in the mid- and late-seasons. As a result, seasonal CH(4) emission in Fe-amended pots was 26% lower than the control with a single 2-day drainage and 69% lower with a double 2-day drainage. The reduction in CH(4) emission upon reflooding from the Fe-amended pots was mainly attributed to the increased Fe(III) regeneration during drainage showing a mechanism of Fe(III) regeneration in mitigating CH(4) emission by short-term drainage in flooded soils.

  13. Dragon Fruit Foliage Plant-Based Coagulant for Treatment of Concentrated Latex Effluent: Comparison of Treatment with Ferric Sulfate

    Directory of Open Access Journals (Sweden)

    Juferi Idris

    2013-01-01

    Full Text Available The effectiveness of dragon fruit foliage as a natural coagulant for treatment of concentrated latex effluent was investigated and compared with ferric sulfate, a chemical coagulant. Dragon fruit is a round and often red-colored fruit with scales-like texture and is native to south American countries which is also cultivated and heavily marketed in southeast Asian countries. Its foliage represents a part of its overall plant system. Latex effluent is one of the main byproduct from rubber processing factories in Malaysia. Three main parameters investigated were chemical oxygen demand (COD, suspended solids (SS, and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of latex effluent pH as well as coagulation dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages for foliage were observed for effluent pH 10 at 94.7, 88.9, and 99.7%, respectively. It is concluded that the foliage showed tremendous potential as a natural coagulant for water treatment purposes. The foliage could be used in the pretreatment stage of Malaysian latex effluent prior to secondary treatment.

  14. Effects of molecular composition of natural organic matter on ferric iron complexation at circumneutral pH.

    Science.gov (United States)

    Fujii, Manabu; Imaoka, Akira; Yoshimura, Chihiro; Waite, T D

    2014-04-15

    Thermodynamic and kinetic parameters for ferric iron (Fe[III]) complexation by well-characterized humic substances (HS) from various origins were determined by a competitive ligand method with 5-sulfosalicylic acid at circumneutral pH (6.0-8.0) and an ionic strength of ∼0.06 M. The measured Fe binding properties including conditional stability constants and complexation capacities ranged over more than 2 orders of magnitude, depending on the origin and the particular operationally defined fraction of HS examined. Statistical comparison of the complexation parameters to a range of chemical properties of the HS indicated a strong positive correlation between Fe(III) complexation capacity and aromatic carbon content in the HS at all pHs examined. In contrast, the complexation capacity was determined to be up to a few orders of magnitude smaller than the concentration of carboxylic and phenolic groups present. Therefore, specific functional groups including those resident in the proximity of aromatic structures within the HS are likely preferable for Fe(III) coordination under the conditions examined. Overall, our results suggest that the concentration of dissolved Fe(III) complexes in natural waters is substantially influenced by variation in HS characteristics in addition to other well-known factors such as HS concentration and nature and concentration of competing cations present.

  15. Dissolution behaviour of ferric pyrophosphate and its mixtures with soluble pyrophosphates: Potential strategy for increasing iron bioavailability.

    Science.gov (United States)

    Tian, Tian; Blanco, Elena; Smoukov, Stoyan K; Velev, Orlin D; Velikov, Krassimir P

    2016-10-01

    Ferric pyrophosphate (FePP) is a widely used iron source in food fortification and in nutritional supplements, due to its white colour, that is very uncommon for insoluble Fe salts. Although its dissolution is an important determinant of Fe adsorption in human body, the solubility characteristics of FePP are complex and not well understood. This report is a study on the solubility of FePP as a function of pH and excess of pyrophosphate ions. FePP powder is sparingly soluble in the pH range of 3-6 but slightly soluble at pH8. In the presence of pyrophosphate ions the solubility of FePP strongly increases at pH 5-8.5 due to formation a soluble complex between Fe(III) and pyrophosphate ions, which leads to an 8-10-fold increase in the total ionic iron concentration. This finding is beneficial for enhancing iron bioavailability, which important for the design of fortified food, beverages, and nutraceutical products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

    Energy Technology Data Exchange (ETDEWEB)

    Dr Robin Gerlach; Erin K. Field; Sridhar Viamajala; Brent M. Peyton; William A. Apel; Al B. Cunningham

    2011-09-01

    Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy's Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity.

  17. Mercury (II) reduction and co-precipitation of metallic mercury on hydrous ferric oxide in contaminated groundwater.

    Science.gov (United States)

    Richard, Jan-Helge; Bischoff, Cornelia; Ahrens, Christian G M; Biester, Harald

    2016-01-01

    Mercury (Hg) speciation and sorption analyses in contaminated aquifers are useful for understanding transformation, retention, and mobility of Hg in groundwater. In most aquifers hydrous ferric oxides (HFOs) are among the most important sorbents for trace metals; however, their role in sorption or mobilization of Hg in aquifers has been rarely analyzed. In this study, we investigated Hg chemistry and Hg sorption to HFO under changing redox conditions in a highly HgCl2-contaminated aquifer (up to 870μgL(-1) Hg). Results from aqueous and solid phase Hg measurements were compared to modeled (PHREEQC) data. Speciation analyses of dissolved mercury indicated that Hg(II) forms were reduced to Hg(0) under anoxic conditions, and adsorbed to or co-precipitated with HFO. Solid phase Hg thermo-desorption measurements revealed that between 55 and 93% of Hg bound to HFO was elemental Hg (Hg(0)). Hg concentrations in precipitates reached more than 4 weight %, up to 7000 times higher than predicted by geochemical models that do not consider unspecific sorption to and co-precipitation of elemental Hg with HFO. The observed process of Hg(II) reduction and Hg(0) formation, and its retention and co-precipitation by HFO is thought to be crucial in HgCl2-contaminated aquifers with variable redox-conditions regarding the related decrease in Hg solubility (factor of ~10(6)), and retention of Hg in the aquifer. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Comparative Evaluation of U.S. Brand and Generic Intravenous Sodium Ferric Gluconate Complex in Sucrose Injection: Physicochemical Characterization

    Directory of Open Access Journals (Sweden)

    Dajun Sun

    2018-01-01

    Full Text Available The objective of this study was to evaluate physicochemical equivalence between brand (i.e., Ferrlecit and generic sodium ferric gluconate (SFG in sucrose injection by conducting a series of comparative in vitro characterizations using advanced analytical techniques. The elemental iron and carbon content, thermal properties, viscosity, particle size, zeta potential, sedimentation coefficient, and molecular weight were determined. There was no noticeable difference between brand and generic SFG in sucrose injection for the above physical parameters evaluated, except for the sedimentation coefficient determined by sedimentation velocity analytical ultracentrifugation (SV-AUC and molecular weight by asymmetric field flow fractionation-multi-angle light scattering (AFFF-MALS. In addition, brand and generic SFG complex products showed comparable molecular weight distributions when determined by gel permeation chromatography (GPC. The observed minor differences between brand and generic SFG, such as sedimentation coefficient, do not impact their biological activities in separate studies of in vitro cellular uptake and rat biodistribution. Coupled with the ongoing clinical study comparing the labile iron level in healthy volunteers, the FDA-funded post-market studies intended to illustrate comprehensive surveillance efforts ensuring safety and efficacy profiles of generic SFG complex in sucrose injection, and also to shed new light on the approval standards on generic parenteral iron colloidal products.

  19. Non-transferrin-bound iron (NTBI uptake by T lymphocytes: evidence for the selective acquisition of oligomeric ferric citrate species.

    Directory of Open Access Journals (Sweden)

    Joao Arezes

    Full Text Available Iron is an essential nutrient in several biological processes such as oxygen transport, DNA replication and erythropoiesis. Plasma iron normally circulates bound to transferrin. In iron overload disorders, however, iron concentrations exceed transferrin binding capacity and iron appears complexed with low molecular weight molecules, known as non-transferrin-bound iron (NTBI. NTBI is responsible for the toxicity associated with iron-overload pathologies but the mechanisms leading to NTBI uptake are not fully understood. Here we show for the first time that T lymphocytes are able to take up and accumulate NTBI in a manner that resembles that of hepatocytes. Moreover, we show that both hepatocytes and T lymphocytes take up the oligomeric Fe3Cit3 preferentially to other iron-citrate species, suggesting the existence of a selective NTBI carrier. These results provide a tool for the identification of the still elusive ferric-citrate cellular carrier and may also open a new pathway towards the design of more efficient iron chelators for the treatment of iron overload disorders.

  20. Novel approach to zinc removal from circum-neutral mine waters using pelletised recovered hydrous ferric oxide.

    Science.gov (United States)

    Mayes, William M; Potter, Hugh A B; Jarvis, Adam P

    2009-02-15

    Data are presented which evaluate the performance of a pilot-scale treatment system using pelletised hydrous ferric oxide (HFO; a waste stream from coal mine water treatment) as a high surface area sorbent for removing zinc (Zn) from a metal mine water discharge in the North Pennines Orefield, UK. Over a 10-month period the system removed Zn at mean area- and volume-adjusted removal rates of 3.7 and 8.1gm(-3)day(-1), respectively, with a mean treatment efficiency of 32% at a low mean residence time of 49min. There were seasonal effects in Zn removal owing to establishment and dieback of algae in the treatment tank. This led to increased Zn uptake in early summer months followed by slight Zn release upon algae senescence. In addition to these biosorptive processes, the principal sinks for Zn appear to be (1) sorption onto the HFO surface, and (2) precipitation with calcite-dominated secondary minerals. The latter were formed as a product of dissolution of portlandite in the cement binder and calcium recarbonation. Further optimisation of the HFO pelletisation process holds the possibility for providing a low-cost, low footprint treatment option for metal rich mine waters, in addition to a valuable after-use for recovered HFO from coal mine water treatment facilities.

  1. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.)

    OpenAIRE

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic ...

  2. Diluting ferric carboxymaltose in sodium chloride infusion solution (0.9% w/v) in polypropylene bottles and bags: effects on chemical stability.

    Science.gov (United States)

    Philipp, Erik; Braitsch, Michaela; Bichsel, Tobias; Mühlebach, Stefan

    2016-01-01

    This study was designed to assess the physicochemical stability of colloidal ferric carboxymaltose solution (Ferinject) when diluted and stored in polypropylene (PP) bottles and bags for infusion. Two batches of ferric carboxymaltose solution (Ferinject) were diluted (500 mg, 200 mg and 100 mg iron in 100 mL saline) in PP bottles or bags under aseptic conditions. The diluted solutions were stored at 30°C and 75%±5% relative humidity (rH) for 72 h, and samples were withdrawn aseptically at preparation and after 24 h, 48 h and 72 h. Multiple parameters were used to test stability-related measures (pH, total iron and iron (II) content, molecular weight range determination, microbial contamination and particles count ≥10 μm). Overall, Ferinject diluted in 0.9% (w/v) NaCl solution and stored in PP bottles and bags was stable within the specifications for the complex and the acceptability limits set for all assays. In both containers, total iron content remained stable, within 10% of the theoretical iron content, and levels of iron (II) remained far below the threshold of acceptability. All preparations were free from sediments, particle numbers were acceptable and there was no microbial contamination. The molecular weight distribution and polydispersity index were also acceptable. Under the tested experimental conditions, colloidal ferric carboxymaltose solution (Ferinject) diluted in saline in PP infusion bottles or bags demonstrated physical and chemical stability for up to 72 h at 30°C and 75% rH. Because of the lack of additional clinical data, when using ferric carboxymaltose, physicians/pharmacists should refer to the dilution and storing recommendations given in the product's summary of product characteristics.

  3. Supplementation with a dietary multicomponent (Lafergin(®)) based on Ferric Sodium EDTA (Ferrazone(®)): results of an observational study.

    Science.gov (United States)

    Cignini, Pietro; Mangiafico, Lucia; Padula, Francesco; D'Emidio, Laura; Dugo, Nella; Aloisi, Alessia; Giorlandino, Claudio; Vitale, Salvatore Giovanni

    2015-01-01

    During pregnancy, iron deficiency anemia is recognized as a specific risk factor for both adverse maternal and perinatal outcome. We decided to test the hypothesis that the daily administration of Lafergin(®), a dietary multicomponent based on Ferrazone(®) (Ferric Sodium EDTA), Lactoferrin, Vitamin C and Vitamin B12, from first trimester of pregnancy until the end of gestation, may significantly reduce, in anemic women, the severity of anemia compared to controls who received ferrous sulfate or liposomal iron.

  4. Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

    International Nuclear Information System (INIS)

    Gandon, Remi

    1982-01-01

    Adsorbents obtained by hydrolysing the Fe 3+ , 6H 2 O ion are made of polymers with aquo (H 2 O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn 2+ , Co 2+ and Mn 2+ cations are exchanged with hydrogen from hydroxo groups. CrO 4 2- , SeO 3 2- and Sb(OH) 6 - anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn 2+ and Sb(OH) 6 - associate with ferric hydroxides from oxidized Fe 2+ . 60 Co, 54 Mn and 51 Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author) [fr

  5. Cost-effectiveness analysis of ferric carboxymaltose in iron-deficient patients with chronic heart failure in Sweden.

    Science.gov (United States)

    Hofmarcher, Thomas; Borg, Sixten

    2015-01-01

    Iron deficiency is a common but treatable comorbidity in chronic heart failure (CHF) that is associated with impaired health-related quality-of-life (HRQoL). This study evaluates the cost-effectiveness of the intravenous iron preparation ferric carboxymaltose (FCM) for the treatment of iron deficiency in CHF from a Swedish healthcare perspective. A cost-effectiveness analysis with a time horizon of 24 weeks was performed to compare FCM treatment with placebo. Data on health outcomes and medical resource use were mainly taken from the FAIR-HF trial and combined with Swedish cost data. An incremental cost-effectiveness ratio (ICER) was calculated as well as the change in per-patient costs for primary care and hospital care. In the FCM group compared with placebo, quality-adjusted life years (QALYs) are higher (difference = 0.037 QALYs), but so are per-patient costs [(difference = SEK 2789 (€303)]. Primary care and hospital care equally share the additional costs, but within hospitals there is a major shift of costs from inpatient care to outpatient care. The ICER is SEK 75,389 (€8194) per QALY. The robustness of the result is supported by sensitivity analyses. Treatment of iron deficiency in CHF with FCM compared with placebo is estimated to be cost-effective. The ICER in the base case scenario is twice as high as previously thought, but noticeably below SEK 500,000 (€54,300) per QALY, an informal average reference value used by the Swedish Dental and Pharmaceutical Benefits Agency. Increased HRQoL and fewer hospitalizations are the key drivers of this result.

  6. Synthesis of LiFePO4/C cathode material from ferric oxide and organic lithium salts

    International Nuclear Information System (INIS)

    Shi Zhongqi; Huang Ming; Huai Yongjian; Lin Ziji; Yang Kerun; Hu Xuebu; Deng Zhenghua

    2011-01-01

    Research highlights: → LiFePO 4 can be synthesized from Fe 2 O 3 by a sequence of free-radical reactions. → Organic lithium salts can avoid the composition segregation of the precursor. → Low cost ferric oxide and environmentally friendly distilled water are used. - Abstract: LiFePO 4 /C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe 2 O 3 , NH 4 H 2 PO 4 , Li 2 C 2 O 4 and lithium polyacrylate (PAALi). The sintering temperature of LiFePO 4 /C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO 4 /C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO 4 /C composite with the particle size of ∼200 nm shows better discharge capacity (156.4 mAh g -1 ) than bare LiFePO 4 (52.3 mAh g -1 ) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO 4 /C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g -1 and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO 4 /C composite.

  7. Removal of some heavy metals from industrial waste water using polyacrylamide ferric antimonate as new ion exchange material

    International Nuclear Information System (INIS)

    El-Aryan, Y.F.A.

    2011-01-01

    Composite ion exchangers consist of one or more ion exchangers combined with another material, which can be inorganic or organic and may it be an ion exchanger. The reason for manufacturing a composite material is to produce a granular material, with sufficient strength for column use, from ion exchangers that do not form, or only form weak, granules themselves. Attempts in this study are focused to prepare composite ion exchangers for treatment of wastewater. Heavy metals when present in water in concentrations exceeding the permitted limits are injurious to the health. Hence, it is very important to treat such waters to remove the metal ions present before it is supplied for any useful purpose. Therefore, many investigations have studied to develop more effective process to treat such waste stream. Ion-exchange has been widely adopted in heavy metal containing wastewater and most of the ion-exchangers (i.e. ion-exchange media) currently being used are commercially mass-produced organic resins.Therefore, the main aim of this work is directed to find the optimum conditions for removal of some heavy metals from industrial waste water.1-Preparation of polyacrylamide ferric antimonate composite.2-Characterization of the prepared exchanger using IR spectra, X-ray diffraction pattern, DTA and TG analyses.3-Chemical stability, capacity and equilibrium measurements will be determined on the materials using at different conditions (ph heating temperature and reaction temperature).4-Kinetic studies of some heavy metals.5-Ion exchange isotherm.6-Breakthrough curves for removal of the investigated metal ions on the prepared exchanger under certain condition.

  8. Bioavailability of iron in cottonseed meal, ferric sulfate, and two ferrous sulfate by-products of the galvanizing industry.

    Science.gov (United States)

    Boling, S D; Edwards, H M; Emmert, J L; Biehl, R R; Baker, D H

    1998-09-01

    Iron depletion-repletion assays were carried out with young chicks to establish Fe bioavailability values for Fe2(SO4)3.7H2O (22.7% Fe), Fe-ZnSO4.H2O (20.2% Fe, 13.0% Zn), Zn-FeSO4.H2O (20.2% Zn, 14.2% Fe), and cottonseed meal (200 mg Fe/kg). Standard hemoglobin response curves were established using feed-grade FeSO4.H2O (28.8% Fe) or reagent-grade FeSO4.7H2O (20.1% Fe) as standards such that relative bioavailability (RBV) could be assessed for the experimental sources of Fe. Weight gain, hemoglobin, and hematocrit responded linearly (P 0.10) from the standard. However, evaluation of all criteria of response (hemoglobin, hematocrit, weight gain) suggested that neither Fe-ZnSO4.H2O nor Zn-FeSO4.H2O had different Fe RBV values than FeSO4.H2O. Standard-curve calculations were used for assessment of Fe RBV in Fe2(SO4)3.7H2O and cottonseed meal, as only a single level of Fe addition was studied for each of these products. Iron RBV in Fe2(SO4)3.7H2O was estimated to be 37%, whereas Fe RBV in cottonseed meal was found to be 56%. Both of these values were lower (P galvanizing industry, are excellent sources of bioavailable Fe, whereas ferric sulfate and cottonseed meal are relatively poor sources of usable Fe.

  9. Does ascorbic acid supplementation affect iron bioavailability in rats fed micronized dispersible ferric pyrophosphate fortified fruit juice?

    Science.gov (United States)

    Haro-Vicente, Juan Francisco; Pérez-Conesa, Darío; Rincón, Francisco; Ros, Gaspar; Martínez-Graciá, Carmen; Vidal, Maria Luisa

    2008-12-01

    Food iron (Fe) fortification is an adequate approach for preventing Fe-deficiency anemia. Poorly water-soluble Fe compounds have good sensory attributes but low bioavailability. The reduction of the particle size of Fe fortificants and the addition of ascorbic acid might increase the bioavailability of low-soluble compounds. The present work aims to compare the Fe absorption and bioavailability of micronized dispersible ferric pyrophosphate (MDFP) (poorly soluble) to ferrous sufate (FS) (highly soluble) added to a fruit juice in presence or absence of ascorbic acid (AA) by using the hemoglobin repletion assay in rats. After a hemoglobin depletion period, four fruit juices comprised of (1) FS, (2) MDFP, (3) FS + AA, (4) MDFP + AA were produced and administered to a different group of rats (n = 18) over 21 days. During the repletion period, Fe balance, hemoglobin regeneration efficiency (HRE), relative bioavailability (RBV) and Fe tissue content were determined in the short, medium and long term. Fe absorption and bioavailability showed no significant differences between fortifying the fruit juice with FS or MDFP. The addition of AA to the juice enhanced Fe absorption during the long-term balance study within the same Fe source. HRE and Fe utilization increased after AA addition in both FS and MDFP groups in every period. Fe absorption and bioavailability from MDFP were comparable to FS added to a fruit juice in rats. Further, the addition of AA enhanced Fe absorption in the long term, as well as Fe bioavailability throughout the repletion period regardless of the Fe source employed.

  10. Vertically grown zinc oxide nanorods functionalized with ferric oxide for in vivo and non-enzymatic glucose detection

    Science.gov (United States)

    Marie, Mohammed; Manoharan, Anishkumar; Kuchuk, Andrian; Ang, Simon; Manasreh, M. O.

    2018-03-01

    An enzyme-free glucose sensor based on vertically grown zinc oxide nanorods (NRs) functionalized with ferric oxide (Fe2O3) is investigated. The well-aligned and high density ZnO NRs were synthesized on an FTO/glass substrate by a sol-gel and hydrothermal growth method. A dip-coating technique was utilized to modify the surface of the as-grown ZnO NRs with Fe2O3. The immobilized surface was coated with a layer of nafion membrane. The fabricated glucose sensor was characterized amperometrically at room temperature using three electrodes stationed in the phosphate buffer solution, where ZnO NRs/Fe2O3/nafion membrane was the sensing or working electrode, and platinum plate and silver/silver chloride were used as the counter and reference electrodes, respectively. The proposed non-enzymatic and modified glucose sensor exhibited a high sensitivity in the order of 0.052 μA cm-2 (mg/dL)-1, a lower detection limit of around 0.95 mmol L-1, a sharp and fast response time of ˜1 s, and a linear response to changes in glucose concentrations from 100-400 mg dL-1. The linear amperometric response of the sensor covers the physiological and clinical interest of glucose levels for diabetic patients. The device continues to function accurately after multiple measurements with a good reproducibility. The proposed glucose sensor is expected to be used clinically for in vivo monitoring of glucose.

  11. Effects of suspended particles on the rate of mass transfer to a rotating disk electrode. [Ferric cyanide

    Energy Technology Data Exchange (ETDEWEB)

    Roha, D.J.

    1981-06-01

    Limiting currents for the reduction of ferric cyanide at a rotating disk were determined in the presence of 0 to 40 percent by volume of spherical glass beads. Experiments were conducted with six different particle diameters, and with rotation speeds in the range of 387 to 270 rpm, usong both a 0.56 cm and a 1.41 cm radius disk electrode. It was established that at a given rpm upon addition of glass beads in the limiting current, i/sub L/, may increase to more than three times its value without solids. This increase in limiting current density is greater at high rotation speeds and with the larger disk electrode. i/sub L/ as a function of particle diameter yields at maximum at approx. 10 ..mu..m. Two mass transfer models are offered to explain this behavior, both of which assume that the beads are in contact with the disk electrode and moving parallel to its surface. In the surface renewal model it is assumed that complete mixing takes place with the passage of each bead and the boundary layer is replaced with fresh bulk solution. While with the particle film model it is assumed the bead and a clinging film of fluid rotate together. The film promotes mass transfer by alternately absorbing and desorbing the diffusing species. The particle film model best explains the observed behavior of the limiting current density. Calculations of stirring power required verses i/sub L/ observed, show that adding beads to increase i/sub L/ consumes less additional power than simply increasing the rotation speed alone and even permits a decrease in the amount of stirring energy required per unit reactant consumed, at limiting current conditions.

  12. Photocatalytic evaluation of self-assembled porous network structure of ferric oxide film fabricated by dry deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yunchan; Kim, Hyungsub; Lee, Geon-Yong; Pawar, Rajendra C.; Lee, Jai-Sung; Lee, Caroline Sunyong, E-mail: sunyonglee@hanyang.ac.kr

    2016-09-15

    Ferric oxide powder in the alpha phase (α-Fe{sub 2}O{sub 3}) was deposited on an aluminum oxide (Al{sub 2}O{sub 3}) substrate by a nanoparticle deposition system using the dry deposition method. X-ray diffraction (XRD) images confirmed that the phase of the deposited α-Fe{sub 2}O{sub 3} did not change. The deposited α-Fe{sub 2}O{sub 3} was characterized in terms of its microstructure using scanning electron microscopy (SEM). A porous network microstructure formed when small agglomerates of Fe{sub 2}O{sub 3} (SAF) were deposited. The deposition and formation mechanism of the microstructure were investigated using SEM and three-dimensional (3D) profile analysis. First, a dense coating layer formed when the film was thinner than the particle size. After that, as the film thickness increased to over 5 μm, the porous network structure formed by excavating the surface of the coating layer as it was bombarded by particles. Rhodamine B (RhB) was degraded after 6 h of exposure to the Fe{sub 2}O{sub 3} coating layer with SAF, which has good photocatalytic activity and a high porous network structure. The kinetic rate constants of the SAF and large agglomerates of Fe{sub 2}O{sub 3} (LAF) were calculated to be 0.197(h{sup −1}) and 0.128(h{sup −1}), respectively, based on the absorbance results. Using linear sweep voltammetry, we confirmed that the photoelectric effect occurred in the coating layer by measuring the resulting current under illuminated and dark conditions. - Graphical abstract: Self-assembled porous photocatalytic film fabricated by dry deposition method for water purification. - Highlights: • Different sizes of Fe{sub 2}O{sub 3} agglomerates were used to form porous network structure. • Fe{sub 2}O{sub 3} agglomerate particles were deposited using solvent-free process. • Self-assembled porous network microstructure formed better with small agglomerates of Fe{sub 2}O{sub 3}. • Fabricated porous network structure showed its potential to be used

  13. Synthesis of LiFePO{sub 4}/C cathode material from ferric oxide and organic lithium salts

    Energy Technology Data Exchange (ETDEWEB)

    Shi Zhongqi; Huang Ming [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Huai Yongjian [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); China Aviation Lithium Battery Co., Ltd, Luoyang, Henan 471003 (China); Lin Ziji; Yang Kerun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Hu Xuebu [Department of Chemistry and Materials, Sichuan Normal University, Chengdu, Sichuan 610068 (China); Zhongke Laifang Power Science and Technology Co., Ltd., Chengdu, Sichuan 610041 (China); Deng Zhenghua, E-mail: zhdeng@cioc.ac.c [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Zhongke Laifang Power Science and Technology Co., Ltd., Chengdu, Sichuan 610041 (China)

    2011-04-15

    Research highlights: {yields} LiFePO{sub 4} can be synthesized from Fe{sub 2}O{sub 3} by a sequence of free-radical reactions. {yields} Organic lithium salts can avoid the composition segregation of the precursor. {yields} Low cost ferric oxide and environmentally friendly distilled water are used. - Abstract: LiFePO{sub 4}/C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe{sub 2}O{sub 3}, NH{sub 4}H{sub 2}PO{sub 4}, Li{sub 2}C{sub 2}O{sub 4} and lithium polyacrylate (PAALi). The sintering temperature of LiFePO{sub 4}/C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO{sub 4}/C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO{sub 4}/C composite with the particle size of {approx}200 nm shows better discharge capacity (156.4 mAh g{sup -1}) than bare LiFePO{sub 4} (52.3 mAh g{sup -1}) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO{sub 4}/C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g{sup -1} and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO{sub 4}/C composite.

  14. The formation, structure, and ageing of As-rich hydrous ferric oxide at the abandoned Sb deposit Pezinok (Slovakia)

    Science.gov (United States)

    Majzlan, Juraj; Lalinská, Bronislava; Chovan, Martin; Jurkovič, L.'ubomír; Milovská, Stanislava; Göttlicher, Jörg

    2007-09-01

    The abandoned Sb deposit Pezinok in Slovakia is a significant source of As and Sb pollution that can be traced in the upper horizons of soils kilometers downstream. The source of the metalloids are two tailing impoundments which hold ˜380,000 m 3 of mining waste. The tailings and the discharged water have circumneutral pH values (7.0 ± 0.6) because the acidity generated by the decomposition of the primary sulfides (pyrite, FeS 2; arsenopyrite, FeAsS; berthierite, FeSb 2S 4) is rapidly neutralized by the abundant carbonates. The weathering rims on the primary sulfides are iron oxides which act as very efficient scavengers of As and Sb (with up to 19.2 wt% As and 23.7 wt% Sb). In-situ μ-XANES experiments indicate that As in the weathering rims is fully oxidized (As 5+). The pore solutions in the impoundment body contain up to 81 ppm As and 2.5 ppm Sb. Once these solutions are discharged from the impoundments, they precipitate or deposit masses of As-rich hydrous ferric oxide (As-HFO) with up to 28.3 wt% As 2O 5 and 2.7 wt% Sb. All As-HFO samples are amorphous to X-rays. They contain Fe and As in their highest oxidation state and in octahedral and tetrahedral coordination, respectively, as suggested by XANES and EXAFS studies on Fe K and As K edges. The iron octahedra in the As-HFO share edges to form short single chains and the chains polymerize by sharing edges or corners with the adjacent units. The arsenate ions attach to the chains in a bidentate-binuclear and monodentate fashion. In addition, hydrogen-bonded complexes may exist to satisfy the bonding requirements of all oxygen atoms in the first coordination sphere of As 5+. Structural changes in the As-HFO samples were traced by chemical analyses and Fe EXAFS spectroscopy during an ageing experiment. As the samples age, As becomes more easily leachable. EXAFS spectra show a discernible trend of increasing number of Fe-Fe pairs at a distance of 3.3-3.5 Å, that is, increasing polymerization of the iron

  15. 188Re radiopharmaceuticals for radiosynovectomy: evaluation and comparison of tin colloid, hydroxyapatite and tin-ferric hydroxide macroaggregates

    International Nuclear Information System (INIS)

    Savio, Eduardo; Ures, María Cristina; Zeledón, Patricia; Trindade, Victoria; Paolino, Andrea; Mockford, Virginia; Malanga, Antonio; Fernández, Marcelo; Gaudiano, Javier

    2004-01-01

    Radiosynovectomy is a therapy used to relieve pain and inflammation from rheumatoid arthritis and related diseases. In this study three 188 Re particulate compounds were characterized according to their physico-chemical properties and their biological behavior in rabbits. The results were compared in order to establish which was the radiopharmaceutical that better fits the requirements of this kind of radiotherapy. Three radiopharmaceutical formulations, tin colloid, hydroxyapatite particles (HA) and ferric hydroxide macroaggregates coated with tin colloid (FHMA), were physically characterized (number, volume and surface of the particles). For this purpose laser diffraction methodology was used. To evaluate cavity leakage of activity the following studies in New Zealand rabbits were performed: scintigraphic images for 48 hr after intraarticular injection of each radiopharmaceutical, biodistribution at 48 hr and urine samples collection during the first 24 hr post-radiopharmaceutical administration. Labeling procedures for 188 Re-HA and 188 Re-Sn-FHMA were labour intensive while 188 Re-Sn was easily prepared. Furthermore, 188 Re-Sn colloid offered the greatest surface area in the 2–10 microm range and was obtained with a radiochemical purity over 95%, while percentage of bound activity for 188 Re-HA and 188 Re-Sn-FHMA were 55% and 92% respectively. Stability was verified for the three radiopharmaceuticals for 24 hr. Scintigraphic studies and biodistribution in rabbits after intraarticular administration of the radiopharmaceuticals showed relevant activity only in the knee, this being over 90% of the residual activity in the whole body at 48 hr in every case. Renal elimination of 188 Re-Sn colloid and 188 Re-Sn-FHMA was detected by activity measurements in urine samples, during the first 12 hr post-radiopharmaceutical injection. The percentage of activity retained in the knee was 69.1% for 188 Re-Sn colloid, 55.1% for 188 Re-Sn-FHMA and 33.6% for 188 Re-HA. The 188

  16. Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

    Science.gov (United States)

    Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

    2015-04-01

    The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

  17. Pyrolysis of the mixture of MSWI fly ash and sewage sludge for co-disposal: Effect of ferrous/ferric sulfate additives.

    Science.gov (United States)

    Hu, Yuyan; Yang, Fan; Chen, Fangfang; Feng, Yuheng; Chen, Dezhen; Dai, Xiaohu

    2018-05-01

    Co-pyrolysis with sewage sludge was proved to be an efficient pre-treatment for sanitary landfill of municipal solid waste incineration (MSWI) fly ash (FA). In this study, to improve the stabilization effect of heavy metals, mixed ferrous/ferric sulfate was added into the FA/SS mixture before pyrolysis. To examine the feasibility of the landfill of co-pyrolysis char, toxicity characteristic leaching procedure (HJ/T300) was conducted. In addition, physio-chemical characteristics of char were also tested to explain the stability of heavy metals, including the speciation, mineralogical composition and the morphological features of them. The results indicated that within the range that the obtained char could meet the standard for landfill (GB16889-2008), the appropriate addition of mixed ferrous/ferric sulfates benefit to raising the FA ratio in the FA/SS mixture. The maximum ratio of 67 wt% is achieved when the additive was 1.5 wt% of dried SS (based on iron element) and the pyrolysis temperature was 500 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Porphyria Cutanea Tarda in a Patient with End-Stage Renal Disease: A Case of Successful Treatment with Deferoxamine and Ferric Carboxymaltose

    Directory of Open Access Journals (Sweden)

    Natacha Rodrigues

    2017-01-01

    Full Text Available Porphyria cutanea tarda (PCT is a rare disease, with a strong association with hepatitis C virus. PCT is particularly problematic in end-stage renal disease patients as they have no renal excretion of porphyrins and these are poorly dialyzed. Also, conventional treatment of PCT is compromised in these patients as hydroxychloroquine is contraindicated, phlebotomies with the stipulated frequency are poorly tolerated in already anaemia-prone patients, and iron-chelating agents are less efficient in removing iron and contribute to worsening anaemia. The authors report a patient on haemodialysis, with hepatitis C infection, that is diagnosed with PCT. Despite the good clinical results with deferoxamine, she became dependent on blood transfusions because of her ferropenic state. Every time oxide iron was started, the patient developed clinical features of the disease, resolving after the suspension of the drug. A decision was made to start the patient on ferric carboxymaltose, which was well tolerated without disease symptoms and need of further blood transfusions. This case suggests that deferoxamine is efficient in treatment of porphyria cutanea tarda. Also, ferric carboxymaltose may be a valuable option for refractory anaemia in patients with this disease and end-stage renal disease, as it seems to provide iron without clinical relapse of the disease.

  19. Measurement of the ferric diffusion coefficient in agarose and gelatine gels by utilization of the evolution of a radiation induced edge as reflected in relaxation rate images

    International Nuclear Information System (INIS)

    Pedersen, Torje V.; Olsen, Dag R.; Skretting, Arne

    1997-01-01

    A method has been developed to determine the diffusion coefficients of ferric ions in ferrous sulphate doped gels. A radiation induced edge was created in the gel, and two spin-echo sequences were used to acquire a pair of images of the gel at different points of time. For each of these image pairs, a longitudinal relaxation rate image was derived. From profiles through these images, the standard deviations of the Gaussian functions that characterize diffusion were determined. These data provided the basis for the determination of the ferric diffusion coefficients by two different methods. Simulations indicate that the use of single spin-echo images in this procedure may in some cases lead to a significant underestimation of the diffusion coefficient. The technique was applied to different agarose and gelatine gels that were prepared, irradiated and imaged simultaneously. The results indicate that the diffusion coefficient is lower in a gelatine gel than in an agarose gel. Addition of xylenol orange to a gelatine gel lowers the diffusion coefficient from 1.45 to 0.81 mm 2 h -1 , at the cost of significantly lower R 1 sensitivity. The addition of benzoic acid to the latter gel did not increase the R 1 sensitivity. (author) OK

  20. Stabilized-solubilized ferric pyrophosphate as a new iron source for food fortification. Bioavailability studies by means of the prophylactic-preventive method in rats.

    Science.gov (United States)

    Salgueiro, M J; Arnoldi, S; Kaliski, M A; Torti, H; Messeri, E; Weill, R; Zubillaga, M; Boccio, J

    2009-02-01

    The purpose of the present work was to evaluate the iron bioavailability of a new ferric pyrophosphate salt stabilized and solubilized with glycine. The prophylactic-preventive test in rats, using ferrous sulfate as the reference standard, was applied as the evaluating methodology both using water and yogurt as vehicles. Fifty female Sprague-Dawley rats weaned were randomized into five different groups (group 1: FeSO(4); group 2: pyr; group 3: FeSO(4) + yogurt; group 4: pyr + yogurt and group 5: control). The iron bioavailability (BioFe) of each compound was calculated using the formula proposed by Dutra-de-Oliveira et al. where BioFe % = (HbFef - HbFei) x 100/ToFeIn. Finally, the iron bioavailability results of each iron source were also given as relative biological value (RBV) using ferrous sulfate as the reference standard. The results showed that both BioFe % and RBV % of the new iron source tested is similar to that of the reference standard independently of the vehicle employed for the fortification procedure (FeSO(4) 49.46 +/- 12.0% and 100%; Pyr 52.66 +/- 15.02% and 106%; FeSO(4) + yogurth 54.39 +/- 13.92% and 110%; Pyr + yogurt 61.97 +/- 13.54% and 125%; Control 25.30 +/- 6.60, p soluble ferric pyrophosphate may be considered as an optimal iron source for food fortification.

  1. Comparison of ferric chloride and aluminum sulfate on phosphorus removal and membrane fouling in MBR treating BAF effluent of municipal wastewater

    Directory of Open Access Journals (Sweden)

    Xin Li

    2017-12-01

    Full Text Available A membrane bioreactor (MBR was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

  2. Comparative Evaluation of U.S. Brand and Generic Intravenous Sodium Ferric Gluconate Complex in Sucrose Injection: In Vitro Cellular Uptake

    Directory of Open Access Journals (Sweden)

    Min Wu

    2017-12-01

    Full Text Available Iron deficiency anemia is a common clinical consequence for people who suffer from chronic kidney disease, especially those requiring dialysis. Intravenous (IV iron therapy is a widely accepted safe and efficacious treatment for iron deficiency anemia. Numerous IV iron drugs have been approved by U.S. Food and Drug Administration (FDA, including a single generic product, sodium ferric gluconate complex in sucrose. In this study, we compared the cellular iron uptake profiles of the brand (Ferrlecit® and generic sodium ferric gluconate (SFG products. We used a colorimetric assay to examine the amount of iron uptake by three human macrophage cell lines. This is the first published study to provide a parallel evaluation of the cellular uptake of a brand and a generic IV iron drug in a mononuclear phagocyte system. The results showed no difference in iron uptake across all cell lines, tested doses, and time points. The matching iron uptake profiles of Ferrlecit® and its generic product support the FDA’s present position detailed in the draft guidance on development of SFG complex products that bioequivalence can be based on qualitative (Q1 and quantitative (Q2 formulation sameness, similar physiochemical characterization, and pharmacokinetic bioequivalence studies.

  3. Standard test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric Chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 These test methods cover procedures for the determination of the resistance of stainless steels and related alloys to pitting and crevice corrosion (see Terminology G 15) when exposed to oxidizing chloride environments. Six procedures are described and identified as Methods A, B, C, D, E, and F. 1.1.1 Method A—Ferric chloride pitting test. 1.1.2 Method B—Ferric chloride crevice test. 1.1.3 Method C—Critical pitting temperature test for nickel-base and chromium-bearing alloys. 1.1.4 Method D—Critical crevice temperature test for nickel-base and chromium-bearing alloys. 1.1.5 Method E—Critical pitting temperature test for stainless steels. 1.1.6 Method F—Critical crevice temperature test for stainless steels. 1.2 Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium-bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys. Methods C, D, E and F allow for a rankin...

  4. High affinity (3H) β-Alanine uptake by scar margins of ferric chloride-induced epileptogenic foci in rat isocortex

    International Nuclear Information System (INIS)

    Robitaille, Y.; Sherwin, A.

    1984-01-01

    Cortical astrocytes of normal mammalian brain are endowed with a high affinity uptake system for β-Alanine which is competitively inhibited by gamma aminobutyric acid (GABA), a neurotransmitter strongly implicated in epileptogenesis. The authors evaluated ( 3 H) β-Alanine uptake by reactive astrocytes proliferating within scar of epileptogenic foci induced in rat motor cortex by microinjections of 100 mM ferric chloride. Following in vitro incubation of scar tissue with ( 3 H) β-Alanine, ultrastructural morphometry of grain patterns at 5, 30 and 120 days post injection revealed early and significant grain count increases over astroglial processes, predominantly those related to perivascular glial end-feet. Astrocytic cell body and endothelial cell counts showed a more gradual and stepwise increase. Similar data were obtained by comparing visual and edited mean astrocytic grain counts. These results suggest that the enhanced uptake of reactive astrocytes may reflect a marked decrease of inhibitory GABAergic neurons within ferric chloride-induced scars. 7 figures, 1 table

  5. Ferric iron remediation and stabilisation (firs) - developing a new robust electrokinetic remediation technique for heavy metal and radionuclide contaminated sites

    International Nuclear Information System (INIS)

    Faulkner, D.; Hopkinson, L.; Cundy, A.

    2005-01-01

    Electrokinetic remediation is an emerging technology that has generated considerable interest as a technique for the in-situ remediation of contaminated clay-rich soils and sediments. Despite promising experimental results, however, at present there is no standardised universal electrokinetic soil/sediment remediation approach. Many of the current technologies are technically complex and energy intensive, and geared towards the removal of 90% or more of specific contaminants, under very specific field or laboratory-based conditions. However, in the real environment a low-tech, low-energy contaminant reduction / containment technique may be more appropriate and realistic. Such a technique, FIRS (Ferric Iron Remediation and Stabilisation), is discussed here. The FIRS technique involves the application of a low magnitude (typically less than 0.2 V/cm) direct electric potential between two or more sacrificial, iron-rich, electrodes emplaced either side of a contaminated soil or sediment. The electric potential is used to generate a strong pH (and Eh) gradient within the soil column (pH 2 - 13), which acts to re-mobilize contaminants in the treated soil, and force the precipitation of an impermeable, sorptive iron-rich barrier or 'pan' in the soil between the electrodes. Geochemical data from bench-scale treatment cells indicate that the FIRS technique can significantly reduce the concentration of a range of heavy metals and radionuclides in contaminated soils, by remobilization of contaminants followed by precipitation on, or around, the iron-rich barrier generated by the technique. In addition, arsenic seems highly amenable to the FIRS treatment, due to its solubility under the high pH conditions generated near to the cathode, and its marked geochemical affinity with the freshly precipitated iron oxides and oxy-hydroxides in the iron barrier. Geotechnical tests indicate that the iron barrier produced by the technique is practically impervious (permeability 10 -9 m

  6. Heterogeneous catalytic ozonation of biologically pretreated Lurgi coal gasification wastewater using sewage sludge based activated carbon supported manganese and ferric oxides as catalysts.

    Science.gov (United States)

    Zhuang, Haifeng; Han, Hongjun; Hou, Baolin; Jia, Shengyong; Zhao, Qian

    2014-08-01

    Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl₂ as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Simultaneous separation of copper, cadmium and cobalt from sea-water by co-flotation with octadecylamine and ferric hydroxide as collectors.

    Science.gov (United States)

    Cabezon, L M; Caballero, M; Cela, R; Perez-Bustamante, J A

    1984-08-01

    A method is proposed for the simultaneous quantitative separation of traces ofCu(II), Cd(II) and Co(II) from sea-water samples by means of the co-flotation (adsorbing colloid flotation) technique with ferric hydroxide as co-precipitant and octadecylamine as collector. The experimental parameters have been studied and optimized. The drawbacks arising from the low solubility of octadecylamine and the corresponding sublates in water have been avoided by use of a 6M hydrochloric acid-MIBK-ethanol (1:2:2 v v ) mixture. The results obtained by means of the proposed method have been compared with those given by the usual ammonium pyrrolidine dithiocarbamate/MIBK extraction method.

  8. Comparison of the Performance of Corn Starch Coagulant Aid Accompany with Alum, Polyaluminum Chloride and Ferric Chloride Coagulants in Turbidity Removal from Water

    Directory of Open Access Journals (Sweden)

    Leila Mosleh

    2014-09-01

    Full Text Available Background: The most important process in water treatment plant is coagulation and flocculation. Regular chemical coagulant which used in Iran are aluminum sulfate (Alum and ferric chloride. Chemical coagulants have hazardous effect on human health and their cost is high for developing country. The purpose of this study was to evaluate the comparison of chemical coagulants accompany with corn starch as a coagulant aid, for the turbidity removal from water. Methods: This study was accomplished in pilot-scale with synthetic turbid water using clay. In this research, initial turbidity of 250 and 500 NTU was experimented. Chemical coagulant dose during the experiment was 1, 2 and 5 ppm and natural coagulant dose was 0, 0.1, 0.3, 0.5 and 0.7 ppm. Results: The results showed that maximum removal efficiency of turbidity in initial turbidity of 250 NTU belonged to poly aluminum chloride with 5 ppm dosage and corn starch with 0.7 ppm dosage which removed and reduced the initial turbidity to 98.48% and 3.73 NTU, respectively. Moreover, in initial turbidity of 500 NTU the maximum removal efficiency was 98.52% which belonged to ferric chloride and corn starch (5 and 0.7 ppm respectively and reduced the initial turbidity to 7.4 NTU. Conclusions: The results of this study showed that using natural coagulant aid reduce the chemical coagulant consumption, and also does not have significant effect on pH range and reduce the health risks. While huge amount of required polyelectrolytes for water treatment plant imported to the country and the production of corn starch in our country is high, it is hope that the results of this project can be used in industrial scale.

  9. Optical and electrical properties of thin films of bismuth ferric oxide; Propiedades opticas y electricas de peliculas delgadas de oxido de bismuto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Cardona R, D.

    2014-07-01

    The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe{sub 2}O{sub 3}) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO{sub 3} in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO{sub 3} composition. These samples showed a secondary phase (Bi{sub 2}5FeO{sub 4}0 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe{sub 2}O{sub 3}) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

  10. New Insight into the Local Structure of Hydrous Ferric Arsenate Using Full-Potential Multiple Scattering Analysis, Density Functional Theory Calculations, and Vibrational Spectroscopy.

    Science.gov (United States)

    Wang, Shaofeng; Ma, Xu; Zhang, Guoqing; Jia, Yongfeng; Hatada, Keisuke

    2016-11-15

    Hydrous ferric arsenate (HFA) is an important arsenic-bearing precipitate in the mining-impacted environment and hydrometallurgical tailings. However, there is no agreement on its local atomic structure. The local structure of HFA was reprobed by employing a full-potential multiple scattering (FPMS) analysis, density functional theory (DFT) calculations, and vibrational spectroscopy. The FPMS simulations indicated that the coordination number of the As-Fe, Fe-As, or both in HFA was approximately two. The DFT calculations constructed a structure of HFA with the formula of Fe(HAsO 4 ) x (H 2 AsO 4 ) 1-x (OH) y ·zH 2 O. The presence of protonated arsenate in HFA was also evidenced by vibrational spectroscopy. The As and Fe K-edge X-ray absorption near-edge structure spectra of HFA were accurately reproduced by FPMS simulations using the chain structure, which was also a reasonable model for extended X-Ray absorption fine structure fitting. The FPMS refinements indicated that the interatomic Fe-Fe distance was approximately 5.2 Å, consistent with that obtained by Mikutta et al. (Environ. Sci. Technol. 2013, 47 (7), 3122-3131) using wavelet analysis. All of the results suggested that HFA was more likely to occur as a chain with AsO 4 tetrahedra and FeO 6 octahedra connecting alternately in an isolated bidentate-type fashion. This finding is of significance for understanding the fate of arsenic and the formation of ferric arsenate minerals in an acidic environment.

  11. Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals

    NARCIS (Netherlands)

    Zimmermann, M.B.; Biebinger, R.; Egli, I.; Zeder, C.; Hurrell, R.F.

    2011-01-01

    Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric

  12. Search for low spin superdeformed states by transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Blons, J; Goutte, D; Lepretre, A; Lucas, R; Meot, V; Paya, D; Phan, X H [DAPNIA SPhN CE Saclay 91191 Gif sur Yvette (France); Barreau, G; Doan, T P; Pedemay, G [CENBG, 33175 Gradignan (France); Becker, J A; Stoyer, M A [LLNL, Livermore, CA (United States)

    1992-08-01

    We present a specific experimental technique aiming to observe superdeformed isomeric states. Preliminary results on two proton transfer reaction on platinum targets leading to {sup 194}Hg are shown. (author). 6 refs., 5 figs.

  13. Low spin models for higher-spin Lagrangians

    Czech Academy of Sciences Publication Activity Database

    Francia, Dario

    2011-01-01

    Roč. 2011, č. 188 (2011), s. 94-105 ISSN 0375-9687. [International Conference on String Field Theory and Related Aspects (SFT2010). Kyoto, 18.10.2010-22.10.2010] Grant - others:EUROHORC and ESF(XE) EYI/07/E010 Institutional research plan: CEZ:AV0Z10100502 Keywords : higher spin theories * Maxwell's equations * open string theory Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.063, year: 2011 http://ptp.ipap.jp/link?PTPS/188/94/

  14. pH dependence of cyanide binding to the ferric heme domain of the direct oxygen sensor from Escherichia coli and the effect of alkaline denaturation.

    Science.gov (United States)

    Bidwai, Anil K; Ok, Esther Y; Erman, James E

    2008-09-30

    The spectrum of the ferric heme domain of the direct oxygen sensor protein from Escherichia coli ( EcDosH) has been measured between pH 3.0 and 12.6. EcDosH undergoes acid denaturation with an apparent p K a of 4.24 +/- 0.05 and a Hill coefficient of 3.1 +/- 0.6 and reversible alkaline denaturation with a p K a of 9.86 +/- 0.04 and a Hill coefficient of 1.1 +/- 0.1. Cyanide binding to EcDosH has been investigated between pH 4 and 11. The EcDosH-cyanide complex is most stable at pH 9 with a K D of 0.29 +/- 0.06 microM. The kinetics of cyanide binding are monophasic between pH 4 and 8. At pH >or=8.5, the reaction is biphasic with the fast phase dependent upon the cyanide concentration and the slow phase independent of cyanide. The slow phase is attributed to conversion of denatured EcDosH to the native state, with a pH-independent rate of 0.052 +/- 0.006 s (-1). The apparent association rate constant for cyanide binding to EcDosH increases from 3.6 +/- 0.1 M (-1) s (-1) at pH 4 to 520 +/- 20 M (-1) s (-1) at pH 11. The dissociation rate constant averages (8.6 +/- 1.3) x 10 (-5) s (-1) between pH 5 and 9, increasing to (1.4 +/- 0.1) x 10 (-3) s (-1) at pH 4 and (2.5 +/- 0.1) x 10 (-3) s (-1) at pH 12.2. The mechanism of cyanide binding is consistent with preferential binding of the cyanide anion to native EcDosH. The reactions of imidazole and H 2O 2 with ferric EcDosH were also investigated and show little reactivity.

  15. Persistent Microvascular Obstruction After Myocardial Infarction Culminates in the Confluence of Ferric Iron Oxide Crystals, Proinflammatory Burden, and Adverse RemodelingCLINICAL PERSPECTIVE

    Energy Technology Data Exchange (ETDEWEB)

    Kali, Avinash; Cokic, Ivan; Tang, Richard; Dohnalkova, Alice; Kovarik, Libor; Yang, Hsin-Jung; Kumar, Andreas; Prato, Frank S.; Wood, John C.; Underhill, David; Marban, Eduardo; Dharmakumar, Rohan

    2016-11-01

    Emerging evidence now supports the notion that persistent microvascular obstruction (PMO) may be more predictive of major adverse cardiovascular events than MI size itself. But, how PMO, a phenomenon limited to the acute/sub-acute period of MI, imparts adverse remodeling throughout the post MI period, particularly after its resolution, is incompletely understood. We hypothesized that PMOs resolve into chronic iron crystals within MI territories and actively impart a proinflammatory burden and adverse remodeling of infarction and LV in the chronic phase of MI. Canine models reperfused (n=20) and non-reperfused (n=20) with and without PMO were studied with serial cardiac MRI to characterize the spatiotemporal relationships between PMO, iron deposition, and infarct and LV remodeling indices between acute (day 7, post MI) and chronic (week 8, post MI). Histopathology and immunohistochemistry were used to validate the iron deposition, microscopically map and quantify the relationship between iron-rich chronic MI regions against pro-inflammatory macrophages, proinflammatory cytokines and matrix metalloproteinase. Atomic resolution transmission electron microscopy (TEM) was used to determine the crystallinity of iron and assess the physical effects of iron on lysosomes within macrophages, and energy-dispersive X-ray spectroscopy (EDS) to identify the chemical composition of the iron composite. Results showed that PMOs lead to iron deposition within chronic MI and that the extent of chronic iron deposition is strongly related to PMO Volume (r>0.6, p<0.001). TEM and EDS analysis showed that iron within chronic MI is found within macrophages as aggregates of nanocrystals of ~2.5 nm diameter in ferric state. Correlative histological studies showed that iron content, proinflammatory burden and collagen degrading enzyme were highly correlated (r >0.7, p<0.001). Iron within chronic MI was significantly associated with infarct resorption (r>0.5, p<0.001) and adverse structural (r

  16. Removal of the blue 1 dye of aqueous solutions using ferric zeolite; Remocion del colorante azul 1 de soluciones acuosas utilizando zeolita ferrica

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo H, S. Y.

    2010-07-01

    Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

  17. Myo-inositol-14C, phytic acid-14C and ferric phytate-14C metabolism through microbian action in an andosol soil

    International Nuclear Information System (INIS)

    Gonzalez I, J.

    1977-01-01

    The myo-inositol- 14 C, phytic acid- 14 C and ferric phytate- 14 C compounds were incubated in an andosol soil at 70% of the field capacity and at 36.5 deg C during twelve days. These compounds suffered a microbian oxidation at 14 CO 2 of 61.0, 1.9 and 0% respectively. The fixation of the phytic acid- 14 C was observed through the fast decrease in the metabolism, due to the formation of complexes with the Fe and Al (phytates). The myo-inositol- 14 C metabolism was reduced by a factor of nine at the second incubation day. The following mechanisms were observed in the myo-inositol metabolism: (i) adsorption of the inositol by the soil minerals, (ii) adsorption by humic acids, (iii) myo-inositol phosphorylation and (iv) epimerization of myo-inositol to chiro-inositol. It was found that the (i) and (ii) formation depends on the soil microbian activity. The (i), (ii) and (iii) interactions were considered as possible mechanisms for the inhibition of the myo-inositol microbian oxidation. The inhibition of the myo-inositol oxidation through adsorption or phosphorylation is considered as a chemical blockade for the hydroaxial group, avoiding this way a microbian oxidation stereospecific of this hydroxil group. (author)

  18. Determination of the biodistribution and biokinetics of radiopharmaca like 166Ho-ferric-hydroxide or 153Sm-EDTMP used for therapeutic treatment by energy dispersive measurements

    International Nuclear Information System (INIS)

    Fischer, H.; Poljanc, K.; Aiginger, H.; Pruefert, U.; Granegger, S.; Ofluoglu, S.; Pirich, Ch.; Sinzinger, H.; Dudczak, R.; Steger, F.

    2003-01-01

    The activity distribution of beta-emitting radionuclides in the human body and the respective therapeutic dose distribution in the target and the unwanted leakage in the other organs was determined by measurement of corresponding gamma-lines. The measurement was done by scanning in a whole-body counter in the General Hospital Vienna. It is possible to localize activity and dose distribution by means of the detected activity profiles of the four detectors. Two typical treatments are reported: the treatment of synovitis using radiation of 166 Ho-Ferric-Hydroxide (characteristic gamma-line: 81 keV) and radionuclide therapy focused at the palliative treatment of bone metastases with 153 Sm-EDTMP, a bone seeking beta-emitting radionuclide (characteristic gamma-line: 103 keV). For the determination of the applied dose, the leakage and the quality assurance spectroscopic data of a clinical whole-body counter can be a useful tool for controlling and monitoring in health care. (authors)

  19. Mechanism of pyrrhotite formation from ferric oxyhydroxide catalyst; Kokoritsu sekitan ekika shokubai no kaihatsu (Okishi suisankatetsu shokubai karano pyrrhotite seisei kyodo)

    Energy Technology Data Exchange (ETDEWEB)

    Tazawa, K.; Koyama, T.; Kaneko, T.; Shimasaki, K. [Nippon Brown Coal Liquefaction Co. Ltd., Tokyo (Japan)

    1996-10-28

    It is thought that iron-based catalysts for coal liquefaction exercise their catalytic activity by forming pyrrhotite (Fe(1-x)S). However, there are still a lot of unknown problems remained concerning the formation and agglomeration behaviors of pyrrhotite. These make a difficulty for improving the activity of iron-based catalysts. In this study, sulfiding behaviors of {alpha}-iron oxyhydroxide ({alpha}-FeOOH) and {gamma}-iron oxyhydroxide ({gamma}-FeOOH) were investigated to reveal the formation and agglomeration behaviors of pyrrhotite. It was found that pyrrhotite was easily converted from ferric oxyhydroxide catalysts having large specific surface areas at the sulfiding temperature below 250{degree}C, and fine crystallites of pyrrhotite were formed at the initial stage of sulfiding. Crystal growth of pyrrhotite at the sulfiding temperature over 350{degree}C depended on the catalyst forms. It was also found that smaller crystallites of pyrrhotite were formed from {gamma}-FeOOH than from {alpha}-FeOOH and amorphous iron oxyhydroxide. 5 refs., 7 figs., 1 tab.

  20. Electrochemical sensing of hydroxylamine using a wax impregnated graphite electrode modified with a nanocomposite consisting of ferric oxide and copper hexacyanoferrate

    International Nuclear Information System (INIS)

    Allibai Mohanan, Vinu Mohan; Kacheri Kunnummal, Aswini; Biju, Valsala Madhavan Nair

    2016-01-01

    The authors describe a wax-impregnated graphite electrode modified with ferric oxide (Fe_2O_3) and copper hexacyanoferrate(II), and its application as an electrochemical sensor for hydroxylamine. The presence of Fe_2O_3 nanoparticles enhance the electron transfer kinetics and electrocatalytic activities, and also enlarge the surface area of the modified electrode. As compared to the unmodified electrode, 16.9 and 30.1 fold enhancements in amperometric response was observed for copper hexacyanoferrate(II) and the nanocomposite modified electrodes, respectively. Also, the presence of Fe_2O_3 in the nanocomposite enhances the anodic current response by 1.78 fold when compared to copper hexacyanoferrate(II) alone modified electrode. The electron transfer coefficient, electron transfer rate constant, diffusion coefficient and catalytic rate constant for the electro-oxidation of hydroxylamine were determined. Amperometry performed at a working voltage of 750 mV (vs. Ag/AgCl) revealed a detection range that extends from 0.8 μM to 100 μM, a detection limit of 0.5 μM (at an S/N ratio of 3) and a sensitivity of 0.0924 mA⋅mM"−"1. The modified electrode is remarkably stable and was successfully applied to the determination of hydroxylamine in spiked water samples. (author)

  1. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L., J. oxycedrus (L., J. phoenicea (L. and Tetraclinis articulata (L.

    Directory of Open Access Journals (Sweden)

    Meryem El Jemli

    2016-01-01

    Full Text Available Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC, and ferric reducing antioxidant power (FRAP assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT, quercetin, and Trolox. The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91±0.37 μg/mL, 19.80±0.55 μg/mL, and 24.23±0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

  2. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.).

    Science.gov (United States)

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT), quercetin, and Trolox). The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91 ± 0.37 μg/mL, 19.80 ± 0.55 μg/mL, and 24.23 ± 0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

  3. The Role of Intermediates in the Process of Red Ferric Pigment Manufacture from FeSO4.7H2O

    International Nuclear Information System (INIS)

    Zboril, Radek; Mashlan, Miroslav; Petridis, Dimitris; Krausova, Dagmar; Pikal, Petr

    2002-01-01

    One method of industrial manufacture of red ferric pigments is based on the thermal decomposition of FeSO 4 .7H 2 O into α-Fe 2 O 3 (copperas red). The difficult reproducibility of the color quality of the final pigment is the main problem of this process. One of the factors that can influence the pigment color is contamination by some of the intermediates formed during the transformation process. The identification of two groups of intermediates is the basic result of an extensive laboratory investigation carried out using 57 Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The first group of intermediates includes sulfato-phases as FeSO 4 .H 2 O, FeSO 4 , Fe(OH)SO 4 , Fe 2 O(SO 4 ) 2 , Fe 2 O(SO 4 ) 2 .xH 2 O x element of (0,1), and Fe 2 (SO 4 ) 3 . Thermally metastable polymorphs of iron(III) oxide, β-Fe 2 O 3 , γ-Fe 2 O 3 and ε-Fe 2 O 3 , represent the other group. Moessbauer characterization of all intermediate products is given. A significant influence of β-Fe 2 O 3 on the pigment color was found.

  4. Inactivation of ferric uptake regulator (Fur) attenuates Helicobacter pylori J99 motility by disturbing the flagellar motor switch and autoinducer-2 production.

    Science.gov (United States)

    Lee, Ai-Yun; Kao, Cheng-Yen; Wang, Yao-Kuan; Lin, Ssu-Yuan; Lai, Tze-Ying; Sheu, Bor-Shyang; Lo, Chien-Jung; Wu, Jiunn-Jong

    2017-08-01

    Flagellar motility of Helicobacter pylori has been shown to be important for the bacteria to establish initial colonization. The ferric uptake regulator (Fur) is a global regulator that has been identified in H. pylori which is involved in the processes of iron uptake and establishing colonization. However, the role of Fur in H. pylori motility is still unclear. Motility of the wild-type, fur mutant, and fur revertant J99 were determined by a soft-agar motility assay and direct video observation. The bacterial shape and flagellar structure were evaluated by transmission electron microscopy. Single bacterial motility and flagellar switching were observed by phase-contrast microscopy. Autoinducer-2 (AI-2) production in bacterial culture supernatant was analyzed by a bioluminescence assay. The fur mutant showed impaired motility in the soft-agar assay compared with the wild-type J99 and fur revertant. The numbers and lengths of flagellar filaments on the fur mutant cells were similar to those of the wild-type and revertant cells. Phenotypic characterization showed similar swimming speed but reduction in switching rate in the fur mutant. The AI-2 production of the fur mutant was dramatically reduced compared with wild-type J99 in log-phase culture medium. These results indicate that Fur positively modulates H. pylori J99 motility through interfering with bacterial flagellar switching. © 2017 John Wiley & Sons Ltd.

  5. Fluorescent sensors based on quinoline-containing styrylcyanine: determination of ferric ions, hydrogen peroxide, and glucose, pH-sensitive properties and bioimaging.

    Science.gov (United States)

    Yang, Xiaodong; Zhao, Peiliang; Qu, Jinqing; Liu, Ruiyuan

    2015-08-01

    A novel styrylcyanine-based fluorescent probe 1 was designed and synthesized via facile methods. Ferric ions quenched the fluorescence of probe 1, whereas the addition of ferrous ions led to only small changes in the fluorescence signal. When hydrogen peroxide was introduced into the solution containing probe 1 and Fe(2+) , Fe(2+) was oxidized to Fe(3+), resulting in the quenching of the fluorescence. The probe 1/Fe(2+) solution fluorescence could also be quenched by H2 O2 released from glucose oxidation by glucose oxidase (GOD), which means that probe 1/Fe(2+) platform could be used to detect glucose. Probe 1 is fluorescent in basic and neutral media but almost non-fluorescent in strong acidic environments. Such behaviour enables it to work as a fluorescent pH sensor in both the solution and solid states and as a chemosensor for detecting volatile organic compounds with high acidity and basicity. Subsequently, the fluorescence microscopic images of probe 1 in live cells and in zebrafish were achieved successfully, suggesting that the probe has good cell membrane permeability and a potential application for imaging in living cells and living organisms. Copyright © 2014 John Wiley & Sons, Ltd.

  6. Comparative evaluation of post-column free radical scavenging and ferric reducing antioxidant power assays for screening of antioxidants in strawberries.

    Science.gov (United States)

    Raudonis, Raimondas; Raudone, Lina; Jakstas, Valdas; Janulis, Valdimaras

    2012-04-13

    ABTS and FRAP post-column techniques evaluate the antioxidant characteristics of HPLC separated compounds with specific reagents. ABTS characterize their ability to scavenge free radicals by electron-donating antioxidants, resulting in the absorbance decrease of the chromophoric radical. FRAP - is based on the reduction of Fe(III)-tripyridyltriazine complex to Fe(II)-tripyridyltriazine at low pH by electron-donating antioxidants, resulting in an absorbance increase. Both post-column assays were evaluated and compared according to the following validation parameters: specificity, precision, limit of detection (LoD), limit of quantitation (LoQ) and linearity. ABTS and FRAP post-column assays were specific, repeatable and sensitive and thus can be used for the evaluation of antioxidant active compounds. Antioxidant active compounds were quantified according to TEAC for each assay and ABTS/FRAP ratio was derived. No previous records of antioxidative activity of leaves and fruits of strawberries (Fragaria viridis, Fragaria moschata) research have been found. The research results confirm the reliability of ABTS and FRAP post-column assays for screening of antioxidants in complex mixtures and the determination of radical scavenging and ferric reducing ability by their TEAC values. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. In situ generated gas bubble-assisted modulation of the morphologies, photocatalytic, and magnetic properties of ferric oxide nanostructures synthesized by thermal decomposition of iron nitrate

    International Nuclear Information System (INIS)

    Tong Guoxiu; Guan Jianguo; Xiao Zhidong; Huang Xing; Guan Yao

    2010-01-01

    Ferric oxide (Fe 2 O 3 ) complex nanoarchitectures with high BET specific surface area, superior photocatalytic activity and modulated magnetic properties are facilely synthesized via controlled thermal decomposition of iron(III) nitrate nonahydrate. The products are characterized by X-ray diffraction, Fourier-transforming infrared spectra, field-emission scanning electron microscope, field-emission high-resolution transmission electron microscope, and nitrogen physisorption and micrometrics analyzer. The corresponding photocatalytic activity and static magnetic properties are also evaluated by measuring the photocatalytic degradation of Rhodamine B aqueous solution under visible light illumination and vibrating sample magnetometer, respectively. Simply tuning the decomposition temperature can conveniently modulate the adsorbing/desorbing behaviors of the in situ generated gases on the nucleus surfaces, and consequently the crystalline structures and morphologies of the Fe 2 O 3 complex nanoarchitectures. The as-prepared Fe 2 O 3 complex nanoarchitectures show strong crystal structure and/or morphology-dependent photocatalytic and magnetic performances. The Fe 2 O 3 complex nanoarchitectures with high specific surface area and favorable crystallization are found to be beneficial for improving the photocatalytic activity. This work not only reports a convenient and low-cost decomposition procedure and a novel formation mechanism of complex nanoarchitectures but also provides an efficient route to enhance catalytic and magnetic properties of Fe 2 O 3 .

  8. Carbon quantum dots directly generated from electrochemical oxidation of graphite electrodes in alkaline alcohols and the applications for specific ferric ion detection and cell imaging.

    Science.gov (United States)

    Liu, Mengli; Xu, Yuanhong; Niu, Fushuang; Gooding, J Justin; Liu, Jingquan

    2016-04-25

    Carbon quantum dots (CQDs) are attracting tremendous interest owing to their low toxicity, water dispersibility, biocompatibility, optical properties and wide applicability. Herein, CQDs with an average diameter of (4.0 ± 0.2) nm and high crystallinity were produced simply from the electrochemical oxidation of a graphite electrode in alkaline alcohols. The as-formed CQDs dispersion was colourless but the dispersion gradually changed to bright yellow when stored in ambient conditions. Based on UV-Vis absorption, fluorescence spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM), this colour change appeared to be due to oxygenation of surface species over time. Furthermore, the CQDs were used in specific and sensitive detection of ferric ion (Fe(3+)) with broad linear ranges of 10-200 μM with a low limit of detection of 1.8 μM (S/N = 3). The application of the CQDs for Fe(3+) detection in tap water was demonstrated and the possible mechanism was also discussed. Finally, based on their good characteristics of low cytotoxicity and excellent biocompatibility, the CQDs were successfully applied to cell imaging.

  9. Mid-infrared and near-infrared spectroscopic study of selected magnesium carbonate minerals containing ferric iron-Implications for the geosequestration of greenhouse gases.

    Science.gov (United States)

    Frost, Ray L; Reddy, B Jagannadha; Bahfenne, Silmarilly; Graham, Jessica

    2009-04-01

    The proposal to remove greenhouse gases by pumping liquefied CO(2) several kilometres below the ground implies that many carbonate containing minerals will be formed. Among these minerals brugnatellite and coalingite are probable. Two ferric ion bearing minerals brugnatellite and coalingite with a hydrotalcite-like structure have been characterised by a combination of infrared and near-infrared (NIR) spectroscopy. The infrared spectra of the OH stretching region are characterised by OH and water stretching vibrations. Both the first and second fundamental overtones of these bands are observed in the NIR spectra in the 7030-7235 cm(-1) and 10,490-10,570 cm(-1) regions. Intense (CO(3))(2-) symmetric and antisymmetric stretching vibrations support the concept that the carbonate ion is distorted. The position of the water bending vibration indicates the water is strongly hydrogen bonded in the mineral structure. Split NIR bands at around 8675 and 11,100 cm(-1) indicate that some replacement of magnesium ions by ferrous ions in the mineral structure has occurred. Near-infrared spectroscopy is ideal for the assessment of the formation of carbonate minerals.

  10. Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl4) and ferric chloride (FeCl3) in algal turbid water

    KAUST Repository

    Chekli, L.; Eripret, C.; Park, S.H.; Tabatabai, S. Assiyeh Alizadeh; Vronska, O.; Tamburic, B.; Kim, J.H.; Shon, H.K.

    2016-01-01

    Seasonal green algae blooms in freshwaters have raised attention on the need to develop novel effective treatment processes for the removal of algae in water. In the present study, the performance of newly developed polytitanium tetrachloride (PTC) coagulant for the removal of freshwater microalga Chlorella vulgaris has been investigated and compared with titanium tetrachloride (TiCl4) coagulant and the conventional ferric chloride (FeCl3) coagulant. The main benefit of using titanium-based coagulants is that the sludge produced after flocculation may be recycled into a valuable product: titanium dioxide photocatalyst. Both titanium-based coagulants achieved good flocculation over a broader pH range and coagulant dose compared to conventional FeCl3 coagulant. All three coagulants achieved comparable performance in terms of turbidity removal (i.e. turbidity removal efficiency >97%); although TiCl4 performed slightly better at the lower tested dose (i.e. <9 mg/L). Zeta potential measurements indicated that charge neutralisation may not be the sole mechanism involved in the coagulation of algae for all three coagulants. Analysis of the dynamic floc size variation during floc breakage showed no regrowth after floc breakage for the three coagulants. The flocs formed by both Ti-based coagulants were larger than those formed by FeCl3 and also grew at a faster rate. This study indicates that Ti-based coagulants are effective and promising coagulants for algae removal in water.

  11. Determinants of quality of life of patients with heart failure and iron deficiency treated with ferric carboxymaltose: FAIR-HF sub-analysis.

    Science.gov (United States)

    Gutzwiller, Florian S; Pfeil, Alena M; Comin-Colet, Josep; Ponikowski, Piotr; Filippatos, Gerasimos; Mori, Claudio; Braunhofer, Peter G; Szucs, Thomas D; Schwenkglenks, Matthias; Anker, Stefan D

    2013-10-09

    Heart failure (HF) is a burden to patients and health care systems. The objectives of HF treatment are to improve health related quality of life (HRQoL) and reduce mortality and morbidity. We aimed to evaluate determinants of health-related quality of life (HRQoL) in patients with iron deficiency and HF treated with intravenous (i.v.) iron substitution or placebo. A randomised, double-blind, placebo-controlled trial (n = 459) in iron-deficient chronic heart failure (CHF) patients with or without anaemia studied clinical and HRQoL benefits of i.v. iron substitution using ferric carboxymaltose (FCM) over a 24-week trial period. Multivariate analysis was carried out with various clinical variables as independent variables and HRQoL measures as dependent variables. Mean change from baseline of European Quality of Life - 5 Dimensions (EQ-5D) (value set-based) utilities (on a 0 to 100 scale) at week 24 was 8.91 (i.v. iron) and 0.68 (placebo; p model remained stable. In this study, i.v. iron substitution, exercise tolerance, stroke, country of residence and renal function influenced measures of HRQoL in patients with heart failure and iron deficiency. © 2013.

  12. Ferrous ammonium phosphate (FeNH₄PO₄) as a new food fortificant: iron bioavailability compared to ferrous sulfate and ferric pyrophosphate from an instant milk drink.

    Science.gov (United States)

    Walczyk, Thomas; Kastenmayer, Peter; Storcksdieck Genannt Bonsmann, Stefan; Zeder, Christophe; Grathwohl, Dominik; Hurrell, Richard F

    2013-06-01

    The main purpose of this study was to establish bioavailability data in humans for the new (Fe) fortification compound ferrous ammonium phosphate (FAP), which was specially developed for fortification of difficult-to-fortify foods where soluble Fe compounds cannot be used due to their negative impact on product stability. A double-blind, randomized clinical trial with cross-over design was conducted to obtain bioavailability data for FAP in humans. In this trial, Fe absorption from FAP-fortified full-cream milk powder was compared to that from ferric pyrophosphate (FPP) and ferrous sulfate. Fe absorption was determined in 38 young women using the erythrocyte incorporation dual stable isotope technique (⁵⁷Fe, ⁵⁸Fe). Geometric mean Fe absorption from ferrous sulfate, FAP and FPP was 10.4, 7.4 and 3.3 %, respectively. Fe from FAP was significantly better absorbed from milk than Fe from FPP (p soluble reference compound (p = 0.0002). Absorption ratios of FAP and FPP relative to ferrous sulfate as a measure of relative bioavailability were 0.71 and 0.32, respectively. The results of the present studies show that replacing FPP with FAP in full-cream milk could significantly improve iron bioavailability.

  13. Effect of pH and Calcium on the Adsorptive Removal of Cadmium and Copper by Iron Oxide–Coated Sand and Granular Ferric Hydroxide

    KAUST Repository

    Uwamariya, V.

    2015-08-17

    Iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were used to study the effect of Ca2+ and pH on the adsorptive removal of Cu2+ and Cd2+ from groundwater using batch adsorption experiments and kinetic modeling. It was observed that Cu2+ and Cd2+ were not stable in synthetic waters. The extent of precipitation increased with increasing pH. Removal of Cu2+ and Cd2+ was achieved through both precipitation and adsorption, with IOCS showing higher adsorption efficiency. Increase of pH (from 6 to 8) resulted in a higher overall removal efficiency of both Cu2+ and Cd2+, with precipitation as predominant removal mechanisms at higher pH values, especially for Cu2+. An increase in Ca2+ concentration increased the precipitation of Cu2+ [as Cu2(OH)2CO3 and Cu3(OH)2(CO3)2] and Cd2+ [as Cd(OH)2 and CdCO3]. In addition, Ca2+ competes with Cu2+ and Cd2+ for surface adsorption sites on IOCS and GFH, and reduces their adsorption capacity. The kinetic modeling revealed that the adsorption of Cd2+ onto IOCS is a complex process, with limited contribution of chemisorption that increases in the presence of Ca2+. © 2015 American Society of Civil Engineers.

  14. Studies on Synthesis of Electrochemically Exfoliated Functionalized Graphene and Polylactic Acid/Ferric Phytate Functionalized Graphene Nanocomposites as New Fire Hazard Suppression Materials.

    Science.gov (United States)

    Feng, Xiaming; Wang, Xin; Cai, Wei; Qiu, Shuilai; Hu, Yuan; Liew, Kim Meow

    2016-09-28

    Practical application of functionalized graphene in polymeric nanocomposites is hampered by the lack of cost-effective and eco-friendly methods for its production. Here, we reported a facile and green electrochemical approach for preparing ferric phytate functionalized graphene (f-GNS) by simultaneously utilizing biobased phytic acid as electrolyte and modifier for the first time. Due to the presence of phytic acid, electrochemical exfoliation leads to low oxidized graphene sheets (a C/O ratio of 14.8) that are tens of micrometers large. Successful functionalization of graphene was confirmed by the appearance of phosphorus and iron peaks in the X-ray photoelectron spectrum. Further, high-performance polylactic acid/f-GNS nanocomposites are readily fabricated by a convenient masterbatch strategy. Notably, inclusion of well-dispersed f-GNS resulted in dramatic suppression on fire hazards of polylactic acid in terms of reduced peak heat-release rate (decreased by 40%), low CO yield, and formation of a high graphitized protective char layer. Moreover, obviously improvements in crystallization rate and thermal conductivities of polylactic acid nanocomposites were observed, highlighting its promising potential in practical application. This novel strategy toward the simultaneous exfoliation and functionalization for graphene demonstrates a simple yet very effective approach for fabricating graphene-based flame retardants.

  15. A hydrogen-ferric ion rebalance cell operating at low hydrogen concentrations for capacity restoration of iron-chromium redox flow batteries

    Science.gov (United States)

    Zeng, Y. K.; Zhao, T. S.; Zhou, X. L.; Zou, J.; Ren, Y. X.

    2017-06-01

    To eliminate the adverse impacts of hydrogen evolution on the capacity of iron-chromium redox flow batteries (ICRFBs) during the long-term operation and ensure the safe operation of the battery, a rebalance cell that reduces the excessive Fe(III) ions at the positive electrolyte by using the hydrogen evolved from the negative electrolyte is designed, fabricated and tested. The effects of the flow field, hydrogen concentration and H2/N2 mixture gas flow rate on the performance of the hydrogen-ferric ion rebalance cell have been investigated. Results show that: i) an interdigitated flow field based rebalance cell delivers higher limiting current densities than serpentine flow field based one does; ii) the hydrogen utilization can approach 100% at low hydrogen concentrations (≤5%); iii) the apparent exchange current density of hydrogen oxidation reaction in the rebalance cell is proportional to the square root of the hydrogen concentration at the hydrogen concentration from 1.3% to 50%; iv) a continuous rebalance process is demonstrated at the current density of 60 mA cm-2 and hydrogen concentration of 2.5%. Moreover, the cost analysis shows that the rebalance cell is just approximately 1% of an ICRFB system cost.

  16. Experimental considerations on the removal of alimentary tract signal in T2 multi shot inversion recovery echo planar imaging using ferric ammonium citrate as contrast agent

    International Nuclear Information System (INIS)

    Kato, Joji; Saito, Haruyoshi; Tomisato, Kenichi; Maruyama, Tomoyuki; Watanabe, Tsuneo; Kawamura, Yoshihiko

    1997-01-01

    We investigated the removal of alimentary tract signal in T 2 echo planar imaging using an oral positive contrast agent for the alimentary tract mainly consisting of ferric ammonium citrate (FerriSeltz: Otsuka Pharmaceutical Co., Ltd.). It has been reported that the FerriSeltz preparation is useful as negative contrast agent because of its enhancing effect of reducing T 2 at high concentrations. However, it was shown to enhance susceptibility artifact in echo planar imaging (EPI). Thus, it is considered difficult to use FerriSeltz at high concentrations in EPI. In contrast, in IR EPI (TI 150 and 200 ms) high concentrations of FerriSeltz are not required, and it is possible to achieve excellent signal suppression at an ordinary concentration of 5.97 mmol/l. This might be due to the fact that the bounce point of FerriSeltz aqueous solution reached about 150 to 200 ms. At present, no effective negative contrast agent for alimentary tract MRI is available. Therefore, it is thought that IR EPI combined with FerriSeltz is a useful technique, since it can eliminate the signal of the alimentary tract at an ordinary concentration. (author)

  17. Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl4) and ferric chloride (FeCl3) in algal turbid water

    KAUST Repository

    Chekli, L.

    2016-11-11

    Seasonal green algae blooms in freshwaters have raised attention on the need to develop novel effective treatment processes for the removal of algae in water. In the present study, the performance of newly developed polytitanium tetrachloride (PTC) coagulant for the removal of freshwater microalga Chlorella vulgaris has been investigated and compared with titanium tetrachloride (TiCl4) coagulant and the conventional ferric chloride (FeCl3) coagulant. The main benefit of using titanium-based coagulants is that the sludge produced after flocculation may be recycled into a valuable product: titanium dioxide photocatalyst. Both titanium-based coagulants achieved good flocculation over a broader pH range and coagulant dose compared to conventional FeCl3 coagulant. All three coagulants achieved comparable performance in terms of turbidity removal (i.e. turbidity removal efficiency >97%); although TiCl4 performed slightly better at the lower tested dose (i.e. <9 mg/L). Zeta potential measurements indicated that charge neutralisation may not be the sole mechanism involved in the coagulation of algae for all three coagulants. Analysis of the dynamic floc size variation during floc breakage showed no regrowth after floc breakage for the three coagulants. The flocs formed by both Ti-based coagulants were larger than those formed by FeCl3 and also grew at a faster rate. This study indicates that Ti-based coagulants are effective and promising coagulants for algae removal in water.

  18. Electrical Properties of Photodiode Ba0.25Sr0.75TiO3 (BST Thin Film Doped with Ferric Oxide on p-type Si (100 Substrate using Chemical Solution Deposition Method

    Directory of Open Access Journals (Sweden)

    Irzaman

    2011-12-01

    Full Text Available In this paper we have grown pure Ba0.25Sr0.75TiO3 (BST and BST doped by Ferric Oxide Fe2O3 (BFST with doping variations of 5%, 10%, and 15% above type-p Silicon (100 substrate using the chemical solution deposition (CSD method with spin coating technique at rotation speed of 3000 rpm, for 30 seconds. BST thin film are made with a concentration of 1 M 2-methoxyethanol and annealing temperature of 850OC for the Si (100 substrate. Characterization of the thin film is performed for the electrical properties such as the current-voltage (I-V curve using Keithley model 2400 as well as dielectric constant, time constant, pyroelectric characteristics, and depth measurement. The results show that the thin film depth increases if the concentration of the Ferric Oxide doping increases. The I-V characterization shows that the BST and BFST thin film has photodiode properties. The dielectric constant increases with the addition of doping. The maximum dielectric constant value is obtained for 15 % doping concentration namely 83.1 for pure BST and 6.89, 11.1, 41.63 and 83.1, respectively for the Ferric Oxide doping based BST with concentration of 5%, 10%, and 15%. XRD spectra of 15 % of ferric oxide doped BST thin film tetragonal phase, we carried out the lattice constant were a = b = 4.203 Å; c = 4.214 Å; c/a ratio = 1.003

  19. FAIRY: a randomized controlled patient-blind phase III study to compare the efficacy and safety of intravenous ferric carboxymaltose (Ferinject®) to placebo in patients with acute isovolemic anemia after gastrectomy - study protocol for a randomized controlled trial

    OpenAIRE

    Reim, Daniel; Kim, Young-Woo; Nam, Byung Ho; Kim, Mi-Jung; Yook, Jeong Hwan; Park, Young Kyu; Roh, Sung Hoon; Yu, Wan Sik; Bae, Jae Moon

    2014-01-01

    Background Isovolemic anemia (decrease in hemoglobin concentration with normal or even increased blood volume) after gastric cancer surgery may negatively influence short- and long-term outcomes. Therefore correction of isovolemic postoperative anemia is supposed to be beneficial. This prospective randomized placebo-controlled multicenter trial is designed to evaluate the efficacy of ferric carboxymaltose administration with the primary end point of successful hemoglobin level increase by 2 g...

  20. Coagulant effect of ferric chloride for separation of biomass from the microalgae Chlorella sp. of the water; Efeito coagulante do cloreto ferrico para separacao da biomassa da microalga Chlorella sp. da agua

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Tamara Daiane de; Mendes, Mucio Andre dos Santos Alves [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola e Ambiental], E-mail: tamara_daiane@yahoo.com.br; Matos, Antonio Teixeira de [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Lo Monaco, Paola Alfonsa Vieira [Instituto Federal do Espirito Santo (IFES), Santa Teresa, ES (Brazil); Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola

    2010-07-01

    Currently, much interest has been focused on the biotechnological potential of microalgae, mainly in the production of biofuels. For this to become viable the biomass of algae should be separated from the water and the process of coagulation/flocculation/sedimentation may be an alternative. This study aimed to evaluate the effect of ferric chloride as coagulant agent of the microalgae Chlorella vulgaris. Were tested five concentrations of ferric chloride in the suspension containing the microalgae: 20,0; 30,0; 40,0; 50,0 e 100,0 g L{sup -1}. The tests were performed using the Jar-test apparatus and the turbidity was measured in suspensions after 2 hours of sedimentation. Mathematical equations were adjusted by regression, relating the concentration used in the tests according to the turbidity of the suspension. There was a linear decrease in turbidity with the addition of ferric chloride, and for concentration of 100.0 g L{sup -1} was achieved a removal efficiency of turbidity of 58%. However, it is necessary to conduct further research, evaluating the economic feasibility of the technique in the separation of microalgae from the water. (author)

  1. Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe(3+)).

    Science.gov (United States)

    Scheers, Nathalie; Rossander-Hulthen, Lena; Torsdottir, Inga; Sandberg, Ann-Sofie

    2016-02-01

    Lactic fermentation of foods increases the availability of iron as shown in a number of studies throughout the years. Several explanations have been provided such as decreased content of inhibitory phytate, increased solubility of iron, and increased content of lactic acid in the fermented product. However, to our knowledge, there are no data to support that the bioavailability of iron is affected by lactic fermentation. The objective of the present study was to investigate whether the bioavailability of iron from a vegetable mix was affected by lactic fermentation and to propose a mechanism for such an event, by conducting human and cell (Caco-2, HepG2) studies and iron speciation measurements (voltammetry). We also investigated whether the absorption of zinc was affected by the lactic fermentation. In human subjects, we observed that lactic-fermented vegetables served with both a high-phytate and low-phytate meal increased the absorption of iron, but not zinc. In vitro digested fermented vegetables were able to provoke a greater hepcidin response per ng Fe than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe(3+) species were increased after the lactic fermentation, while there was no significant change in hydrated Fe(2+). Furthermore, lactate addition to Caco-2 cells did not affect ferritin formation in response to Fe nor did lactate affect the hepcidin response in the Caco-2/HepG2 cell system. The mechanism for the increased bioavailability of iron from lactic-fermented vegetables is likely an effect of the increase in ferric iron (Fe(3+)) species caused by the lactic fermentation. No effect on zinc bioavailability was observed.

  2. Impacts of vegetation and temperature on the treatment of domestic sewage in constructed wetlands incorporated with Ferric-Carbon micro-electrolysis material.

    Science.gov (United States)

    Zhou, Qingwei; Zhu, Hui; Bañuelos, Gary; Yan, Baixing; Liang, Yinxiu; Yu, Jing; Li, Huai

    2017-10-03

    Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) material had been widely used for the pretreatment of wastewater. Therefore, we hypothesized that Fe/C-M/E material could enhance the treatment of domestic sewage when it was integrated into constructed wetlands (CWs). In this study, CWs integrated with Fe/C-M/E material were developed. Druing the experiment of effect of vegetation on the performance of CWs, percentages of NH 4 + -N, NO 3 - -N, total nitrogen (TN), and Chemical Oxygen Demand (COD) removed in polyculture (W1) were up to 91.8%, 97.0%, 92.3%, and 85.4%, respectively, which were much higher than those in Lythrum salicaria monoculture (W2) and Canna indica monoculture (W3). In the experiment of temperature influences on the removal efficiency of CWs, temperature substantially influenced the performance of CWs. For example, NO 3 - -N removal percentages of W1, W2, and W3 at high temperature (25.5°C and 19.8°C) were relatively stable and greater than 85.4%. At 8.9°C, however, a sharp decline of NO 3 - -N removal percentage was observed in all CWs. Temperature also influenced the Chemical Oxygen Demand (COD) removal and soil microbial activity and biomass. Overall, the polyculture (Lythrum salicaria +Canna indica) showed the best performance during most of the operating time, at an average temperature ≥ 19.8°C, due to the functional complementarity between vegetation. All the CWs consistently achieved high removal efficiency (above 96%) for TP in all experiments, irrespective of vegetation types, phosphorous loadings, and temperatures. In conclusion, polyculture was an attractive solution for the treatment of domestic sewage during most of the operating time (average temperature ≥ 19.8°C). Furthermore, CWs with Fe/C-M/E material were ideally suitable for domestic sewage treatment, especially for TP removal.

  3. Single and combined effects of phosphate, silicate, and natural organic matter on arsenic removal from soft and hard groundwater using ferric chloride

    Science.gov (United States)

    Chanpiwat, Penradee; Hanh, Hoang Thi; Bang, Sunbaek; Kim, Kyoung-Woong

    2017-06-01

    In order to assess the effects of phosphate, silicate and natural organic matter (NOM) on arsenic removal by ferric chloride, batch coprecipitation experiments were conducted over a wide pH range using synthetic hard and soft groundwaters, similar to those found in northern Vietnam. The efficiency of arsenic removal from synthetic groundwater by coprecipitation with FeCl3 was remarkably decreased by the effects of PO4 3-, SiO4 4- and NOM. The negative effects of SiO4 4- and NOM on arsenic removal were not as strong as that of PO4 3-. Combining PO4 3- and SiO4 4- increased the negative effects on both arsenite (As3+) and arsenate (As5+) removal. The introduction of NOM into the synthetic groundwater containing both PO4 3- and SiO4 4- markedly magnified the negative effects on arsenic removal. In contrast, both Ca2+ and Mg2+ substantially increased the removal of As3+ at pH 8-12 and the removal of As5+ over the entire pH range. In the presence of Ca2+ and Mg2+, the interaction of NOM with Fe was either removed or the arsenic binding to Fe-NOM colloidal associations and/or dissolved complexes were flocculated. Removal of arsenic using coprecipitation by FeCl3 could not sufficiently reduce arsenic contents in the groundwater (350 μg/L) to meet the WHO guideline for drinking water (10 μg/L), especially when the arsenic-rich groundwater also contains co-occurring solutes such as PO4 3-, SiO4 4- and NOM; therefore, other remediation processes, such as membrane technology, should be introduced or additionally applied after this coprecipitation process, to ensure the safety of drinking water.

  4. Safety of intravenous ferric carboxymaltose versus oral iron in patients with nondialysis-dependent CKD: an analysis of the 1-year FIND-CKD trial.

    Science.gov (United States)

    Roger, Simon D; Gaillard, Carlo A; Bock, Andreas H; Carrera, Fernando; Eckardt, Kai-Uwe; Van Wyck, David B; Cronin, Maureen; Meier, Yvonne; Larroque, Sylvain; Macdougall, Iain C

    2017-09-01

    The evidence base regarding the safety of intravenous (IV) iron therapy in patients with chronic kidney disease (CKD) is incomplete and largely based on small studies of relatively short duration. FIND-CKD (ClinicalTrials.gov number NCT00994318) was a 1-year, open-label, multicenter, prospective study of patients with nondialysis-dependent CKD, anemia and iron deficiency randomized (1:1:2) to IV ferric carboxymaltose (FCM), targeting higher (400-600 µg/L) or lower (100-200 µg/L) ferritin, or oral iron. A post hoc analysis of adverse event rates per 100 patient-years was performed to assess the safety of FCM versus oral iron over an extended period. The safety population included 616 patients. The incidence of one or more adverse events was 91.0, 100.0 and 105.0 per 100 patient-years in the high ferritin FCM, low ferritin FCM and oral iron groups, respectively. The incidence of adverse events with a suspected relation to study drug was 15.9, 17.8 and 36.7 per 100 patient-years in the three groups; for serious adverse events, the incidence was 28.2, 27.9 and 24.3 per 100 patient-years. The incidence of cardiac disorders and infections was similar between groups. At least one ferritin level ≥800 µg/L occurred in 26.6% of high ferritin FCM patients, with no associated increase in adverse events. No patient with ferritin ≥800 µg/L discontinued the study drug due to adverse events. Estimated glomerular filtration rate remained the stable in all groups. These results further support the conclusion that correction of iron deficiency anemia with IV FCM is safe in patients with nondialysis-dependent CKD. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA.

  5. Particle Size, Surface Area, and Amorphous Content as Predictors of Solubility and Bioavailability for Five Commercial Sources of Ferric Orthophosphate in Ready-To-Eat Cereal.

    Science.gov (United States)

    Dickmann, Robin S; Strasburg, Gale M; Romsos, Dale R; Wilson, Lori A; Lai, Grace H; Huang, Hsimin

    2016-03-01

    Ferric orthophosphate (FePO₄) has had limited use as an iron fortificant in ready-to-eat (RTE) cereal because of its variable bioavailability, the mechanism of which is poorly understood. Even though FePO₄ has desirable sensory properties as compared to other affordable iron fortificants, few published studies have well-characterized its physicochemical properties. Semi-crystalline materials such as FePO₄ have varying degrees of molecular disorder, referred to as amorphous content, which is hypothesized to be an important factor in bioavailability. The objective of this study was to systematically measure the physicochemical factors of particle size, surface area, amorphous content, and solubility underlying the variation in FePO₄ bioavailability. Five commercial FePO₄ sources and ferrous sulfate were added to individual batches of RTE cereal. The relative bioavailability value (RBV) of each iron source, determined using the AOAC Rat Hemoglobin Repletion Bioassay, ranged from 51% to 99% (p Solubility in dilute HCl accurately predicted RBV (R² = 0.93, p = 0.008). Amorphous content measured by Dynamic Vapor Sorption ranged from 1.7% to 23.8% and was a better determinant of solubility (R² = 0.91; p = 0.0002) than surface area (R² = 0.83; p = 0.002) and median particle size (R² = 0.59; p = 0.12). The results indicate that while solubility of FePO₄ is highly predictive of RBV, solubility, in turn, is strongly linked to amorphous content and surface area. This information may prove useful for the production of FePO₄ with the desired RBV.

  6. Particle Size, Surface Area, and Amorphous Content as Predictors of Solubility and Bioavailability for Five Commercial Sources of Ferric Orthophosphate in Ready-To-Eat Cereal

    Directory of Open Access Journals (Sweden)

    Robin S. Dickmann

    2016-03-01

    Full Text Available Ferric orthophosphate (FePO4 has had limited use as an iron fortificant in ready-to-eat (RTE cereal because of its variable bioavailability, the mechanism of which is poorly understood. Even though FePO4 has desirable sensory properties as compared to other affordable iron fortificants, few published studies have well-characterized its physicochemical properties. Semi-crystalline materials such as FePO4 have varying degrees of molecular disorder, referred to as amorphous content, which is hypothesized to be an important factor in bioavailability. The objective of this study was to systematically measure the physicochemical factors of particle size, surface area, amorphous content, and solubility underlying the variation in FePO4 bioavailability. Five commercial FePO4 sources and ferrous sulfate were added to individual batches of RTE cereal. The relative bioavailability value (RBV of each iron source, determined using the AOAC Rat Hemoglobin Repletion Bioassay, ranged from 51% to 99% (p < 0.05, which is higher than typically reported. Solubility in dilute HCl accurately predicted RBV (R2 = 0.93, p = 0.008. Amorphous content measured by Dynamic Vapor Sorption ranged from 1.7% to 23.8% and was a better determinant of solubility (R2 = 0.91; p = 0.0002 than surface area (R2 = 0.83; p = 0.002 and median particle size (R2 = 0.59; p = 0.12. The results indicate that while solubility of FePO4 is highly predictive of RBV, solubility, in turn, is strongly linked to amorphous content and surface area. This information may prove useful for the production of FePO4 with the desired RBV.

  7. Sodium ferric gluconate (SFG) in complex with sucrose for IV infusion: bioequivalence of a new generic product with the branded product in healthy volunteers.

    Science.gov (United States)

    Baribeault, David

    2011-08-01

    Parenteral sodium ferric gluconate in complex (Ferrlecit [branded SFG]) is used to treat patients with iron deficiency anemia undergoing chronic hemodialysis and receiving supplemental epoetin. This comparative pharmacokinetic study (GeneraMedix, Inc., Study 17909) evaluates whether the recently approved generic product Nulecit (generic SFG) and the branded product Ferrlecit (branded SFG) are bioequivalent. In this open-label study, 240 healthy volunteers in a fasting state were assigned randomly to a single 10-min intravenous (IV) infusion of 125 mg of generic or branded SFG. Total and transferrin-bound iron concentrations were determined for the 36-h period after infusion and corrected for pretreatment levels. Maximum concentration (Cmax) and area under the concentration-time curve of 0 to 36 h (AUC[0-36]) were compared between the two products. Demonstration of bioequivalence required that the 90% confidence intervals of each parameter evaluated for generic SFG were within 80% to 125% of the corresponding values for branded SFG. Uncorrected and baseline-corrected mean serum concentrations of total serum iron during the 36-h assessment period were similar for generic and branded SFG. For total serum iron, the geometric mean ratios of corrected Cmax and AUC[0-36] were 100%. For transferrin-bound iron, the geometric mean ratios were 87% for corrected Cmax and 92% for corrected AUC[0-36]. All associated 90% confidence intervals were within the range of 80% to 125%. A new generic SFG in complex for IV infusion is bioequivalent to the branded SFG in complex for IV infusion. The generic SFG is AB rated by the FDA and considered therapeutically equivalent to the branded product.

  8. Efficacy and Tolerability of Intravenous Ferric Carboxymaltose in Patients with Iron Deficiency at a Hospital Outpatient Clinic: A Retrospective Cohort Study of Real-World Clinical Practice

    Directory of Open Access Journals (Sweden)

    António Robalo Nunes

    2017-01-01

    Full Text Available Ferric carboxymaltose (FCM is an intravenous iron formulation to correct iron deficiency. Although its use has been extensively studied in clinical trials, real-world evidence regarding FCM treatment is scarce. Our aim was to evaluate the efficacy and tolerability of FCM treatment in patients with iron deficiency, with or without anemia, at a hospital outpatient clinic. Data was collected retrospectively from medical records. During this 2-year study, 459 patients were included. Mean age was 58.6 ± 17.5 years and most patients received cumulative FCM doses of 501–1000 mg (63.2%. Six weeks after administration of FCM, efficacy endpoints hemoglobin increase ≥2 g/dL, hemoglobin increase ≥3 g/dL, and transferrin saturation > 20% were attained by 41%, 20%, and 63% of patients, respectively. Patients who received higher FCM doses showed significant reduced odds of not achieving hemoglobin increase ≥2 g/dL (501–1000 mg, adjusted odds ratio [OR]: 0.34, 95% confidence interval [CI] 0.18–0.62; 1001–3000 mg, OR: 0.19, 95% CI 0.07–0.49, compared to 500 mg doses. Treatment-emergent adverse events were documented in <4% of patients. In conclusion, FCM treatment was effective and well-tolerated by outpatients with iron deficiency at a hospital clinic, and its dosage should be adjusted to improve iron deficiency management in clinical practice.

  9. The Bradyrhizobium japonicum Ferrous Iron Transporter FeoAB Is Required for Ferric Iron Utilization in Free Living Aerobic Cells and for Symbiosis.

    Science.gov (United States)

    Sankari, Siva; O'Brian, Mark R

    2016-07-22

    The bacterium Bradyrhizobium japonicum USDA110 does not synthesize siderophores for iron utilization in aerobic environments, and the mechanism of iron uptake within symbiotic soybean root nodules is unknown. An mbfA bfr double mutant defective in iron export and storage activities cannot grow aerobically in very high iron medium. Here, we found that this phenotype was suppressed by loss of function mutations in the feoAB operon encoding ferrous (Fe(2+)) iron uptake proteins. Expression of the feoAB operon genes was elevated under iron limitation, but mutants defective in either gene were unable to grow aerobically over a wide external ferric (Fe(3+)) iron (FeCl3) concentration range. Thus, FeoAB accommodates iron acquisition under iron limited and iron replete conditions. Incorporation of radiolabel from either (55)Fe(2+) or (59)Fe(3+) into cells was severely defective in the feoA and feoB strains, suggesting Fe(3+) reduction to Fe(2+) prior to traversal across the cytoplasmic membrane by FeoAB. The feoA or feoB deletion strains elicited small, ineffective nodules on soybean roots, containing few bacteria and lacking nitrogen fixation activity. A feoA(E40K) mutant contained partial iron uptake activity in culture that supported normal growth and established an effective symbiosis. The feoA(E40K) strain had partial iron uptake activity in situ within nodules and in isolated cells, indicating that FeoAB is the iron transporter in symbiosis. We conclude that FeoAB supports iron acquisition under limited conditions of soil and in the iron-rich environment of a symbiotic nodule. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Core–shell structure carbon coated ferric oxide (Fe{sub 2}O{sub 3}@C) nanoparticles for supercapacitors with superior electrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Yipeng [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Zhang, Haiyan [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Chen, Yiming, E-mail: chenym@gdut.edu.cn [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Deng, Peng; Huang, Zhikun [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Liu, Liying; Qian, Yannan; Li, Yunyong [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Li, Qingyu [School of Chemistry and Chemistry Engineering, Guangxi Normal University, Guilin 541004 (China)

    2015-08-05

    Highlights: • Fe{sub 2}O{sub 3}@C was prepared by using arc discharge method followed by heat treatment. • KOH activation made the core–shell structure Fe{sub 2}O{sub 3}@C porous. • The activated-Fe{sub 2}O{sub 3}@C supercapacitor exhibited superior electrochemical performance. - Abstract: Core–shell structure carbon coated ferric oxide nanoparticles (Fe{sub 2}O{sub 3}@C) were fabricated by the oxidation of carbon coated iron nanoparticles (Fe@C) prepared by a direct current carbon arc discharge method. Porous activated-Fe{sub 2}O{sub 3}@C was prepared by KOH activation of Fe{sub 2}O{sub 3}@C at the temperature of 750 °C. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize the structure and morphology of the Fe{sub 2}O{sub 3}@C and activated-Fe{sub 2}O{sub 3}@C. The specific surface area and pore size distribution of the samples were also tested. The activated-Fe{sub 2}O{sub 3}@C electrodes exhibited good electrochemical performance with a maximum specific capacitance of 612 F g{sup −1} at the charge/discharge current density of 0.5 A g{sup −1} with 5 M NaOH electrolyte. After 10,000 cycling DC tests at the charge/discharge current density of 4 A g{sup −1}, a high level specific capacitance of 518 F g{sup −1} was obtained (90.6% retention of the initial capacity), suggesting excellent long-term cycling stability.

  11. Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge

    Directory of Open Access Journals (Sweden)

    Akira Homma

    1974-01-01

    Full Text Available Quantitative method of viral pollution determination for large volume of water using ferric hydroxide gel impregnated on the surface of glassfibre cartridge filter. The use of ferric hydroxide gel, impregnated on the surface of glassfibre cartridge filter enable us to recover 62.5% of virus (Poliomylitis type I, Lsc strain exsogeneously added to 400 liters of tap-water. The virus concentrator system consists of four cartridge filters, in which the three first one are clarifiers, where the contaminants are removed physically, without significant virus loss at this stage. The last cartridge filter is impregnated with ferric hydroxide gel, where the virus is adsorbed. After the required volume of water has been processed, the last filter is removed from the system and the viruses are recovered from the gel, using 1 liter of glycine/NaOH buffer, at pH 11. Immediately the eluate is clarified through series of cellulose acetate membranes mounted in a 142mm Millipore filter. For the second step of virus concentration, HC1 1N is added slowly to the eluate to achieve pH 3.5-4. MgC1, is added to give a final concentration of 0.05M and the viruses are readsorbed on a 0.45 , porosity (HA cellulose acetate membrane, mounted in a 90 mm Millipore filter. The viruses are recovered using the same eluent plus 10% of fetal calf serum, to a final volume of 3 ml. In this way, it was possible to concentrate virus from 400 liters of tap-water, into 1 liter in the first stage of virus concentration and just to 3 ml of final volume in a second step. The efficiency, simplicity and low operational cost, provded by the method, make it feasible to study viral pollution of recreational and tap-water sources.Relata-se o emprego de um concentrador portátil, o qual se mostrou capaz de recuperar 62,5% dos vírus (Polio I, amostra Lsc experimentalmente dispersos em 400 litros de água, os quais foram reduzidos a 3 ml. O sistema concentrador de vírus é composto de quatro

  12. Bioavailable Ferric Iron (BAFelll) Assay

    Science.gov (United States)

    2007-02-01

    citrate dithionite bicarbonate CDBFe citrate dithionite bicarbonate extractable iron cDCE cis-Dichloroethene CDM Camp Dresser & McKee Inc...Defense (DoD) installations. Camp Dresser & McKee Inc. (CDM), in cooperation with the Naval Facilities Engineering Services Center (NFESC), was the...several upgradient and/or cross - gradient background soil samples. Duplicate analysis of samples is recommended. While these recommendations are not

  13. Enhancing the Process of Anaerobic Ammonium Oxidation Coupled to Iron Reduction in Constructed Wetland Mesocosms with Supplementation of Ferric Iron Hydroxides

    Science.gov (United States)

    Shuai, W.; Jaffe, P. R.

    2017-12-01

    Effective ammonium (NH4+) removal has been a challenge in wastewater treatment processes. Aeration, which is required for the conventional NH4+ removal approach by ammonium oxidizing bacteria, is an energy intensive process during the operation of wastewater treatment plant. The efficiency of NH4+ oxidation in natural systems is also limited by oxygen transfer in water and sediments. The objective of this study is to enhance NH4+ removal by applying a novel microbial process, anaerobic NH4+ oxidation coupled to iron (Fe) reduction (also known as Feammox), in constructed wetlands (CW). Our studies have shown that an Acidimicrobiaceae bacterium named A6 can carry out the Feammox process using ferric Fe (Fe(III)) minerals like ferrihydrite as their electron acceptor. To investigate the properties of the Feammox process in CW as well as the influence of electrodes, Feammox bacterium A6 was inoculated in planted CW mesocosms with electrodes installed at multiple depths. CW mesocosms were operated using high NH4+ nutrient solution as inflow under high or low sediment Fe(III) level. During the operation, NH4+ and ferrous Fe concentration, pore water pH, voltages between electrodes, oxidation reduction potential and dissolved oxygen were measured. At the end of the experiment, CW sediment samples at different depths were taken, DNAs were extracted and quantitative polymerase chain reaction and pyrosequencing were performed to analyze the microbial communities. The results show that the high Fe level CW mesocosm has much higher NH4+ removal ability than the low Fe level CW mesocosm after Fe-reducing conditions are developed. This indicates the enhanced NH4+ removal can be attributed to elevated Feammox activity in high Fe level CW mesocosm. The microbial community structures are different in high or low Fe level CW mesocosms and on or away from the installed electrodes. The voltages between cathode and anode increased after the injection of A6 enrichment culture in low Fe

  14. Cyanide binding to hexacoordinate cyanobacterial hemoglobins: hydrogen-bonding network and heme pocket rearrangement in ferric H117A Synechocystis hemoglobin.

    Science.gov (United States)

    Vu, B Christie; Nothnagel, Henry J; Vuletich, David A; Falzone, Christopher J; Lecomte, Juliette T J

    2004-10-05

    The truncated hemoglobin (Hb) from the cyanobacterium Synechocystis sp. PCC 6803 is a bis-histidyl hexacoordinate complex in the absence of exogenous ligands. This protein can form a covalent cross-link between His117 in the H-helix and the heme 2-vinyl group. Cross-linking, the physiological importance of which has not been established, is avoided with the His117Ala substitution. In the present work, H117A Hb was used to explore exogenous ligand binding to the heme group. NMR and thermal denaturation data showed that the replacement was of little consequence to the structural and thermodynamic properties of ferric Synechocystis Hb. It did, however, decelerate the association of cyanide ions with the heme iron. Full complexation required hours, instead of minutes, of incubation at optical and NMR concentrations. At neutral pH and in the presence of excess cyanide, binding occurred with a first-order dependence on cyanide concentration, eliminating distal histidine decoordination as the rate-limiting step. The cyanide complex of the H117A variant was characterized for the conformational changes occurring as the histidine on the distal side, His46 (E10), was displaced. Extensive rearrangement allowed Tyr22 (B10) to insert in the heme pocket and Gln43 (E7) and Gln47 (E11) to come in contact with it. H-bond formation to the bound cyanide was identified in solution with the use of (1)H(2)O/(2)H(2)O mixtures. Cyanide binding also resulted in a change in the ratio of heme orientational isomers, in a likely manifestation of heme environment reshaping. Similar observations were made with the related Synechococcus sp. PCC 7002 H117A Hb, except that cyanide binding was rapid in this protein. In both cases, the (15)N chemical shift of bound cyanide was reminiscent of that in peroxidases and the orientation of the proximal histidine was as in other truncated Hbs. The ensemble of the data provided insight into the structural cooperativity of the heme pocket scaffold and pointed

  15. Adrenaline and triiodothyronine modify the iron handling in the freshwater air-breathing fish Anabas testudineus Bloch: role of ferric reductase in iron acquisition.

    Science.gov (United States)

    Rejitha, V; Peter, M C Subhash

    2013-01-15

    The effects of in vivo adrenaline and triiodothyronine (T(3)) on ferric reductase (FR) activity, a membrane-bound enzyme that reduces Fe(III) to Fe(II) iron, were studied in the organs of climbing perch (Anabas testudineus Bloch). Adrenaline injection (10 ng g(-1)) for 30 min produced significant inhibition of FR activity in the liver and kidney and that suggests a role for this stress hormone in iron acquisition in this fish. Short-term T(3) injection (40 ng g(-1)) reduced FR activity in the gills of fed fish but not in the unfed fish. Similar reduction of FR activity was also obtained in the intestine and kidney of fed fish after T(3) injection. Feeding produced pronounced decline in FR activity in the spleen but T(3) challenge in fed and unfed fish increased its activity in this iron storing organ and that point to the sensitivity of FR system to feeding activity. The in vitro effects of Fe on FR activity in the gill explants of freshwater fish showed correlations of FR with Na(+), K(+)-ATPase and H(+)-ATPase activities. Substantial increase in the FR activity was found in the gill explants incubated with all the tested doses of Fe(II) iron (1.80, 3.59 and 7.18 μM) and Fe(III) iron (1.25, 2.51 and 5.02 μM) and this indicate that FR and Na pump activity are positively correlated. On the contrary, substantial reduction of gill H(+)-ATPase activity was found in the gill explants incubated with Fe(II) iron and Fe(III) iron indicating that perch gills may not require a high acidic microenvironment for the reduction of Fe(III) iron. Accumulation of iron in the gill explants after Fe(III) iron incubation implies a direct relationship between Fe acquisition and FR activity in this tissue. The inverse correlation between FR activity and H(+)-ATPase activity in Fe(II) or Fe(III) loaded gills and the significant positive correlations of FR activity with total [Fe] content in the Fe(III) loaded gills substantiate that FR which shows sensitivity to sodium and proton pumps

  16. FIND-CKD: a randomized trial of intravenous ferric carboxymaltose versus oral iron in patients with chronic kidney disease and iron deficiency anaemia.

    Science.gov (United States)

    Macdougall, Iain C; Bock, Andreas H; Carrera, Fernando; Eckardt, Kai-Uwe; Gaillard, Carlo; Van Wyck, David; Roubert, Bernard; Nolen, Jacqueline G; Roger, Simon D

    2014-11-01

    The optimal iron therapy regimen in patients with non-dialysis-dependent chronic kidney disease (CKD) is unknown. Ferinject® assessment in patients with Iron deficiency anaemia and Non-Dialysis-dependent Chronic Kidney Disease (FIND-CKD) was a 56-week, open-label, multicentre, prospective and randomized study of 626 patients with non-dialysis-dependent CKD, anaemia and iron deficiency not receiving erythropoiesis-stimulating agents (ESAs). Patients were randomized (1:1:2) to intravenous (IV) ferric carboxymaltose (FCM), targeting a higher (400-600 µg/L) or lower (100-200 µg/L) ferritin or oral iron therapy. The primary end point was time to initiation of other anaemia management (ESA, other iron therapy or blood transfusion) or haemoglobin (Hb) trigger of two consecutive values <10 g/dL during Weeks 8-52. The primary end point occurred in 36 patients (23.5%), 49 patients (32.2%) and 98 patients (31.8%) in the high-ferritin FCM, low-ferritin FCM and oral iron groups, respectively [hazard ratio (HR): 0.65; 95% confidence interval (CI): 0.44-0.95; P = 0.026 for high-ferritin FCM versus oral iron]. The increase in Hb was greater with high-ferritin FCM versus oral iron (P = 0.014) and a greater proportion of patients achieved an Hb increase ≥1 g/dL with high-ferritin FCM versus oral iron (HR: 2.04; 95% CI: 1.52-2.72; P < 0.001). Rates of adverse events and serious adverse events were similar in all groups. Compared with oral iron, IV FCM targeting a ferritin of 400-600 µg/L quickly reached and maintained Hb level, and delayed and/or reduced the need for other anaemia management including ESAs. Within the limitations of this trial, no renal toxicity was observed, with no difference in cardiovascular or infectious events. NCT00994318. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA.

  17. Comparing soluble ferric pyrophosphate to common iron salts and chelates as sources of bioavailable iron in a Caco-2 cell culture model.

    Science.gov (United States)

    Zhu, Le; Glahn, Raymond P; Nelson, Deanna; Miller, Dennis D

    2009-06-10

    Iron bioavailability from supplements and fortificants varies depending upon the form of the iron and the presence or absence of iron absorption enhancers and inhibitors. Our objectives were to compare the effects of pH and selected enhancers and inhibitors and food matrices on the bioavailability of iron in soluble ferric pyrophosphate (SFP) to other iron fortificants using a Caco-2 cell culture model with or without the combination of in vitro digestion. Ferritin formation was the highest in cells treated with SFP compared to those treated with other iron compounds or chelates. Exposure to pH 2 followed by adjustment to pH 7 markedly decreased FeSO(4) bioavailability but had a smaller effect on bioavailabilities from SFP and sodium iron(III) ethylenediaminetetraacetate (NaFeEDTA), suggesting that chelating agents minimize the effects of pH on iron bioavailability. Adding ascorbic acid (AA) and cysteine to SFP in a 20:1 molar ratio increased ferritin formation by 3- and 2-fold, respectively, whereas adding citrate had no significant effect on the bioavailability of SFP. Adding phytic acid (10:1) and tannic acid (1:1) to iron decreased iron bioavailability from SFP by 91 and 99%, respectively. The addition of zinc had a marked inhibitory effect on iron bioavailability. Calcium and magnesium also inhibited iron bioavailability but to a lesser extent. Incorporating SFP in rice greatly reduced iron bioavailability from SFP, but this effect can be partially reversed with the addition of AA. SFP and FeSO(4) were taken up similarly when added to nonfat dry milk. Our results suggest that dietary factors known to enhance and inhibit iron bioavailability from various iron sources affect iron bioavailability from SFP in similar directions. However, the magnitude of the effects of iron absorption inhibitors on SFP iron appears to be smaller than on iron salts, such as FeSO(4) and FeCl(3). This supports the hypothesis that SFP is a promising iron source for food fortification

  18. Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

    Science.gov (United States)

    Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

    2017-03-01

    Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at

  19. Actinide speciation bound to hydrous ferric oxide colloids in the near-field conditions of the waste pond at 'Mayak' facility (Russia)

    International Nuclear Information System (INIS)

    Kalmykov, St.; Khasanova, A.; Kriventsov, V.; Teterin, Y.; Novikov, A.

    2007-01-01

    Full text of publication follows: 'Mayak' facility is a nuclear waste and spent nuclear fuel reprocessing plant located in Ural Mountains, Russia. The opened pond, Karachay Lake, was used for several decades for the discharge of low- and intermediate level waste solutions containing fission products and traces of actinides. Due to high salt concentration and high density of waste solutions, they are penetrating into the groundwater system that is represented by oxic Eh conditions. The speciation of actinides in groundwater samples collected close to Karachay Lake was studied by successive micro- and ultra-filtrations with subsequent SEM, TEM, nano-SIMS, membrane extraction and other techniques. It was established that U and Np were found in soluble fraction (pass through 10 kD ultra-filter) in the form of their bi- and tri-carbonate complexes that was supported by chemical thermodynamic calculations. In contrast, Pu and Am were bound to nano-colloids 10 kD - 50 nm in size. The SEM and TEM data indicate the presence of variety of different colloidal particles which relative concentration decrease in the row: hydrous ferric oxides (HFO) >> clays ≅ calcite > rutile ≅ hematite ≅ barite ≅ MnO 2 > monazite > other phases. The SIMS with submicron resolution (Cameca nanoSIMS-50) was used to study local concentration of actinides. According to the obtained data among different colloids detected in the sample actinides were preferentially bound to HFO and MnO 2 while other phases did not sorb actinides. In order to determine actinide speciation bound to HFO colloids XPS and An L 3 edge XAFS measurements were done at Siberian Synchrotron Radiation Centre. The storage ring VEPP-3 with electron beam energy of 2 GeV and an average stored current of 80 mA was used as the source of radiation. Since the concentration of actinides in actual samples was too low for XAFS, the samples for measurements were prepared by contacting about 10 -5 M solutions of Np(V) and Pu(V) with

  20. Moessbauer, electron paramagnetic resonance and magnetic susceptibility studies of photosensitive nitrile hydratase from Rhodococcus sp. N-771

    International Nuclear Information System (INIS)

    Nagamune, Teruyuki; Honda, Jun; Kobayashi, Yoshio; Sasabe, Hiroyuki; Endo, Isao; Ambe, Fumitoshi; Teratani, Yoshitaka; Hirata, Akira

    1992-01-01

    Moessbauer, magnetic susceptibility and electron paramagnetic resonance (EPR) studies of inactive and photoactivated NHase enzymes were performed to elucidate the electronic change of non-heme two-iron atom center of the enzyme by photoactivation. These spectroscopic investigations revealed that both the two iron atoms of the active NHase could be assigned to low-spin ferric state, and those of the inactive NHase could each be assigned to low-spin ferric and low-spin ferrous ones. From these results, it was concluded that one of the non-heme iron atoms is oxidized in the inactive NHase during photoactivation. (orig.)

  1. Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous; Simulacao da difusao de ions ferricos em dosimetros Fricke-Xilenol-Gel em meios nao homogeneos

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Caio J.; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Matematica e Estatistica. Departamento de Matematica Aplicada; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L., E-mail: rodrijr@ipen.br, E-mail: Icrodri@ipen.br, E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (lPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2013-11-01

    Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe{sup 3+}), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe{sup 3+} in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

  2. FAIRY: a randomized controlled patient-blind phase III study to compare the efficacy and safety of intravenous ferric carboxymaltose (Ferinject®) to placebo in patients with acute isovolemic anemia after gastrectomy - study protocol for a randomized controlled trial.

    Science.gov (United States)

    Reim, Daniel; Kim, Young-Woo; Nam, Byung Ho; Kim, Mi-Jung; Yook, Jeong Hwan; Park, Young Kyu; Roh, Sung Hoon; Yu, Wan Sik; Bae, Jae Moon

    2014-04-05

    Isovolemic anemia (decrease in hemoglobin concentration with normal or even increased blood volume) after gastric cancer surgery may negatively influence short- and long-term outcomes. Therefore correction of isovolemic postoperative anemia is supposed to be beneficial. This prospective randomized placebo-controlled multicenter trial is designed to evaluate the efficacy of ferric carboxymaltose administration with the primary end point of successful hemoglobin level increase by 2 g/dl at 12 weeks after randomization. Gastric cancer patients after oncologic resection and postoperative hemoglobin level ≥ 7 g/dl to hemoglobin level, hematology and quality of life assessment 3 and 12 weeks after randomization. Correction of isovolemic postoperative anemia in gastric cancer patients after oncologic resection is considered to be beneficial. Administration of ferric carboxymaltose is considered to be superior to placebo for anemia correction without the possible risks of red blood cell transfusion. Further, improved quality of life for patients with quick recovery of hemoglobin levels is expected. NCT01725789 (international: http://www.clinicaltrials.gov) and NCCCTS-12-644 (NCC, Korea).

  3. Hard X-ray total scattering study on the structure of Si-dopped ferric oxyhydroxides and products of their transformation

    Science.gov (United States)

    Pieczara, Gabriela; Borkiewicz, Olaf; Manecki, Maciej; Rzepa, Grzegorz

    2016-04-01

    Here we report the results of a detailed structural investigation, using synchrotron-based pair distribution function analyses (PDF) and high-resolution X-ray diffraction (HR-XRD), on a series of Si-bearing synthetic analogues of ferrihydrite with a range of Si/Fe ratio relevant to geological environments and on products of their thermal transformation. Hard X-ray total scattering data suitable for PDF analyses have been collected at the PDF-dedicated beamline 11-ID-B and the HR-XRD data at beamline 11-BM of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). Ferrihydrite is a poorly crystalline, nano-sized hydrous ferric oxyhydroxide with a nominal/ideal formula Fe5HO8•4H2O. Its chemical composition however, can vary significantly and the atomic structure is yet to be fully understood despite multitude of structural studies undertaken over the past two decades (Michel et al., 2007; Manceau, 2009). One of the most commonly discussed and still unsettled contention points regarding the structural arrangements of ferrihydrite is related to the presence or absence of tetraherdally coordinated iron(III) within its structure. The majority of experimental work carried out to date focused on pure, synthetic ferrihydrite analogues with chemical composition close to ideal/nominal. This approach is clearly a significant oversimplification of natural ferrihydrite which always contains substantial amounts of admixtures, with Si, C, P, As, Ca, S and Al being the most common. One of the most important and the most commonly encountered impurities is Si, in the form of silicate ion that has strong affinity for ferrihydrite. SiO2content in natural ferrihydrites can vary substantially but generally falls with the range of 2.6-31.5 wt% (Cismasu et al., 2011). In certain environments however, such as modern seafloor hydrothermal vents, higher Si/Fe ratios (up to ca. 3) have been reported (Sun et al., 2013). The results of previous reports indicate that silicate

  4. The influence of aquatic humic substances characteristics on the coagulation efficiency using ferric chloride; Influencia das caracteristicas das substancias humicas aquaticas na eficiencia da coagulacao com o cloreto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Sloboda, Eliane; Vieira, Eny Maria [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica], e-mail: elisloboda@hotmail.com; Dantas, Angela Di Bernardo; Bernardo, Luiz Di [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Hidraulica e Saneamento

    2009-07-01

    The aim of this study was to verify the influence of the apparent molecular size of aquatic humic substances on the effectiveness of coagulation with ferric chloride. Coagulation-filtration tests using jar test and bench-scale sand filters were carried out on samples of water with true color of approximately 100 Hazen units, prepared with aquatic humic substances of different molecular sizes (F{sub 1}: < 0.45 {mu}m, F{sub 2}: 100 kDa - 0.45 {mu}m, F{sub 3}: 30 - 100 kDa and F{sub 4}{sup '} : < 30 kDa). For the water samples with lower apparent molecular size fractions, greater dosages of coagulant was needed to remove the color around 5.0 Hanzen units, mainly because these water samples contain higher concentrations of fulvic acids, which exhibited a larger number of negatively-charged groups. (author)

  5. Coordination modes of tyrosinate-ligated catalase-type heme enzymes: magnetic circular dichroism studies of Plexaura homomalla allene oxide synthase, Mycobacterium avium ssp. paratuberculosis protein-2744c, and bovine liver catalase in their ferric and ferrous states.

    Science.gov (United States)

    Bandara, D M Indika; Sono, Masanori; Bruce, Grant S; Brash, Alan R; Dawson, John H

    2011-12-01

    Bovine liver catalase (BLC), catalase-related allene oxide synthase (cAOS) from Plexaura homomalla, and a recently isolated protein from the cattle pathogen Mycobacterium avium ssp. paratuberculosis (MAP-2744c (MAP)) are all tyrosinate-ligated heme enzymes whose crystal structures have been reported. cAOS and MAP have low (enzymes in their ferric and ferrous states using magnetic circular dichroism and UV-visible absorption spectroscopy. The MAP protein shows remarkable spectral similarities to cAOS and BLC in its native Fe(III) state, but clear differences from ferric proximal heme ligand His93Tyr Mb (myoglobin) mutant, which may be attributed to the presence of an Arg(+)-N(ω)-H···¯O-Tyr (proximal heme axial ligand) hydrogen bond in the first three heme proteins. Furthermore, the spectra of Fe(III)-CN¯, Fe(III)-NO, Fe(II)-NO (except for five-coordinate MAP), Fe(II)-CO, and Fe(II)-O(2) states of cAOS and MAP, but not H93Y Mb, are also similar to the corresponding six-coordinate complexes of BLC, suggesting that a tyrosinate (Tyr-O¯) is the heme axial ligand trans to the bound ligands in these complexes. The Arg(+)-N(ω)-H to ¯O-Tyr hydrogen bond would be expected to modulate the donor properties of the proximal tyrosinate oxyanion and, combined with the subtle differences in the catalytic site structures, affect the activities of cAOS, MAP and BLC. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Hemes férricos pentacoordenados e hexacoordenados dos monômeros d nativo e reconstituído da hemoglobina extracelular de Glossoscolex paulistus: estudos espectroscópicos em meio ácido Pentacoordinate and hexacoordinate ferric hemes from the native and reconstituted d monomers of Glossoscolex paulistus extracellular hemoglobin: spectroscopic studies in acid medium

    Directory of Open Access Journals (Sweden)

    Julio C. Ribelatto

    2005-10-01

    Full Text Available UV-Vis and fluorescence spectroscopic studies of the native and reconstituted d monomers of Glossoscolex paulistus were performed in acid medium. The coexistence of distinct species shows the complexity of the equilibria. Besides the hexacoordinate low spin hemichrome, with bands at 535 and 565 nm, a pentacoordinate high spin hemichrome is identified by the blue-shifted low intensity Soret band (371 nm and the LMCT band (643 nm. The pentacoordinate hemichrome must be related to the partial unfolding of the polypeptide.

  7. Development of Surface Complexation Models of Cr(VI) Adsorption on Soils, Sediments and Model Mixtures of Kaolinite, Montmorillonite, γ-Alumina, Hydrous Manganese and Ferric Oxides and Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Koretsky, Carla [Western Michigan University

    2013-11-29

    Hexavalent chromium is a highly toxic contaminant that has been introduced into aquifers and shallow sediments and soils via many anthropogenic activities. Hexavalent chromium contamination is a problem or potential problem in the shallow subsurface at several DOE sites, including Hanford, Idaho National Laboratory, Los Alamos National Laboratory and the Oak Ridge Reservation (DOE, 2008). To accurately quantify the fate and transport of hexavalent chromium at DOE and other contaminated sites, robust geochemical models, capable of correctly predicting changes in chromium chemical form resulting from chemical reactions occurring in subsurface environments are needed. One important chemical reaction that may greatly impact the bioavailability and mobility of hexavalent chromium in the subsurface is chemical binding to the surfaces of particulates, termed adsorption or surface complexation. Quantitative thermodynamic surface complexation models have been derived that can correctly calculate hexavalent chromium adsorption on well-characterized materials over ranges in subsurface conditions, such pH and salinity. However, models have not yet been developed for hexavalent chromium adsorption on many important constituents of natural soils and sediments, such as clay minerals. Furthermore, most of the existing thermodynamic models have been developed for relatively simple, single solid systems and have rarely been tested for the complex mixtures of solids present in real sediments and soils. In this study, the adsorption of hexavalent chromium was measured as a function of pH (3-10), salinity (0.001 to 0.1 M NaNO3), and partial pressure of carbon dioxide(0-5%) on a suite of naturally-occurring solids including goethite (FeOOH), hydrous manganese oxide (MnOOH), hydrous ferric oxide (Fe(OH)3), γ-alumina (Al2O3), kaolinite (Al2Si2O5(OH)4), and montmorillonite (Na3(Al, Mg)2Si4O10(OH)2-nH2O). The results show that all of these materials can bind substantial quantities of

  8. Molecular dynamics investigation of ferrous-ferric electron transfer in a hydrolyzing aqueous solution: Calculation of the pH dependence of the diabatic transfer barrier and the potential of mean force

    International Nuclear Information System (INIS)

    Rustad, James R.; Rosso, Kevin M.; Felmy, Andrew R.

    2004-01-01

    We present a molecular model for ferrous-ferric electron transfer in an aqueous solution that accounts for electronic polarizability and exhibits spontaneous cation hydrolysis. An extended Lagrangian technique is introduced for carrying out calculations of electron-transfer barriers in polarizable systems. The model predicts that the diabatic barrier to electron transfer increases with increasing pH, due to stabilization of the Fe 3+ by fluctuations in the number of hydroxide ions in its first coordination sphere, in much the same way as the barrier would increase with increasing dielectric constant in the Marcus theory. We have also calculated the effect of pH on the potential of mean force between two hydrolyzing ions in aqueous solution. As expected, increasing pH reduces the potential of mean force between the ferrous and ferric ions in the model system. The magnitudes of the predicted increase in diabatic transfer barrier and the predicted decrease in the potential of mean force nearly cancel each other at the canonical transfer distance of 0.55 nm. Even though hydrolysis is allowed in our calculations, the distribution of reorganization energies has only one maximum and is Gaussian to an excellent approximation, giving a harmonic free energy surface in the reorganization energy F(ΔE) with a single minimum. There is thus a surprising amount of overlap in electron-transfer reorganization energies for Fe 2+ -Fe(H 2 O) 6 3+ , Fe 2+ -Fe(OH)(H 2 O) 5 2+ , and Fe 2+ -Fe(OH) 2 (H 2 O) + couples, indicating that fluctuations in hydrolysis state can be viewed on a continuum with other solvent contributions to the reorganization energy. There appears to be little justification for thinking of the transfer rate as arising from the contributions of different hydrolysis states. Electronic structure calculations indicate that Fe(H 2 O) 6 2+ -Fe(OH) n (H 2 O) 6-n (3-n)+ complexes interacting through H 3 O 2 - bridges do not have large electronic couplings

  9. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging.

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-14

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM(+) on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 ± 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection.

  10. Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals.

    Science.gov (United States)

    Zimmermann, Michael B; Biebinger, Ralf; Egli, Ines; Zeder, Christophe; Hurrell, Richard F

    2011-04-01

    Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyrophosphate (FPP) and (2) to compare the efficacy of FS with FPP in a fortification trial to increase body Fe stores in Fe-deficient children v. Fe-sufficient children. Using stable isotopes in test meals in young women (n 49) selected for low and high Fe status, we compared the absorption of FPP with FS. We analysed data from previous efficacy trials in children (n 258) to determine whether Fe status at baseline predicted response to FS v. FPP as salt fortificants. Plasma ferritin was a strong negative predictor of Fe bioavailability from FS (P soluble Fe compounds not only demonstrate better overall absorption and can be used at lower fortification levels, but they also have the added advantage that, because their absorption is up-regulated in Fe deficiency, they innately 'target' Fe-deficient individuals in a population.

  11. Comparison of the Performance of Poly Aluminum Chloride (PACl, Ferric Chloride (FeCl3, in Turbidity and Organic Matter Removal; from Water Source, Case-Study: Karaj River, in Tehran Water Treatment Plant No. 2

    Directory of Open Access Journals (Sweden)

    Mohammad Abdolah zadeh

    2009-06-01

    Full Text Available Coagulation and flocculation are the principal units in water treatment processes. In this study, the Jar test was used to investigate the effects of the pH and TOC on FeCl3 and PACl coagulants for further removal of turbidity, organic matter, aluminum, total organic carbon (TOC, dissolved organic carbon (DOC, organic Aadsorption at a wavelength of 254 nm (UV254 nm , alkalinity, residual aluminum and ferric, total trihalomethans (TTHMs in the Karaj River in the year 2007- 2008. These experiments were conducted through a bench scale study using conventional coagulation in the influent to Tehran Water Treatment Plant No. 2 (TWTP2.With normal pH levels, PACl demonstrated more efficiency than FeCl3 in removing turbidity, TOC, UV254 nm, and TTHMs. The lower coagulant consumption, high floc size, lower floc detention time, lower sludge production, lack of the need for pH adjustment in turbidity of 25 NTU and the lower alum consumption were the advantages of PACl application instead of FeCl3 as a coagulant. Also, PACl application was efficient at low turbidity (2 NTU, average turbidity (6 NTU, and high turbidity (100 NTU in TOC, turbidity, UV254 nm , and DOC removal. Thus, PACl is an economical alternative as a coagulant in TWTP2.

  12. Design of an effective bifunctional catalyst organotriphosphonic acid-functionalized ferric alginate (ATMP-FA) and optimization by Box-Behnken model for biodiesel esterification synthesis of oleic acid over ATMP-FA.

    Science.gov (United States)

    Liu, Wei; Yin, Ping; Liu, Xiguang; Qu, Rongjun

    2014-12-01

    Biodiesel production has become an intense research area because of rapidly depleting energy reserves and increasing petroleum prices together with environmental concerns. This paper focused on the optimization of the catalytic performance in the esterification reaction of oleic acid for biodiesel production over the bifunctional catalyst organotriphosphonic acid-functionalized ferric alginate ATMP-FA. The reaction parameters including catalyst amount, ethanol to oleic acid molar ratio and reaction temperature have been optimized by response surface methodology (RSM) using the Box-Behnken model. It was found that the reaction temperature was the most significant factor, and the best conversion ratio of oleic acid could reach 93.17% under the reaction conditions with 9.53% of catalyst amount and 8.62:1 of ethanol to oleic acid molar ratio at 91.0 °C. The research results show that two catalytic species could work cooperatively to promote the esterification reaction, and the bifunctional ATMP-FA is a potential catalyst for biodiesel production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

    KAUST Repository

    Sinha, Shahnawaz

    2011-09-30

    The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated mic - rosand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of C eq = 10 μg/L were 500 mg/L for AA and GFH, 520–1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60–95 % .

  14. Phytochemical composition, total phenolic content and ferric ...

    African Journals Online (AJOL)

    Nigerian Journal of Technological Research ... The phytochemical analysis revealed the presence of alkaloids, flavonoids, saponins, tannins, terpenoids ... The leaf extract also gave the highest FRAP value, with the root bark extract having the ...

  15. Low-spin electromagnetic transition probabilities in {sup 102,104}Cd

    Energy Technology Data Exchange (ETDEWEB)

    Jolie, J.; Dewald, A.; Fransen, C.; Linnemann, A.; Melon, B.; Moeller, O. [Inst. fuer Kernphysik, Univ. zu Koeln (Germany); Boelaert, N. [Inst. fuer Kernphysik, Univ. zu Koeln (Germany); Dept. of Subatomic and Radiation Physics, Gent Univ. (Belgium); Smirnova, N.; Heyde, K. [Dept. of Subatomic and Radiation Physics, Gent Univ. (Belgium)

    2007-07-01

    Lifetimes of low-lying states in {sup 102,104}Cd were determined by using the recoil distance Doppler shift technique with a plunger device and a Ge array consisting of five HP Ge detectors and one Euroball cluster detector. The experiments were carried out at the Cologne FN Tandem accelerator using the {sup 92,94}Mo({sup 12}C,2n){sup 102,104}Cd reactions. The differential decay curve method in coincidence mode was employed to derive the lifetime of the first excited 2{sup +} state in both nuclei and the first excited 4{sup +} state in {sup 104}Cd. The corresponding E2 transition probabilities agree well with large scale shell-model calculations. (orig.)

  16. Off-Yrast low-spin structure of deformed nuclei at mass number A∼150

    Energy Technology Data Exchange (ETDEWEB)

    Krugmann, Andreas

    2014-07-14

    The present work consists of two independent parts. The first part deals with the investigation of the 0{sup +}{sub 1}→0{sup +}{sub 2} transition in {sup 150}Nd with inelastic electron scattering and in the second part a proton scattering experiment for the investigation of dipole excitations is presented. In the first part of this thesis a pioneer experiment in inelastic electron scattering is introduced. At an electron energy of 75 MeV, excitation energy spectra have been measured at the high resolution 169 spectrometer at the S-DALINAC. The aim of this investigation was the determination of the ρ{sup 2}(E0;0{sup +}{sub 1}→0{sup +}{sub 2}) transition strength in the heavy deformed nucleus {sup 150}Nd. The experimental form factor of this particular transition has been compared to a theoretical form factor that has been constructed by an effective density operator on a microscopic level with the help of the generator coordinate method. The required collective wave functions have been calculated in the Confined β soft rotor model. In this model-dependent analysis the E0 transition strength has been determined for the first time. Furthermore the evolution of the E0 transition strength as a function of the potential stiffness has been investigated from the X(5) phase shape transitional point to the Rigid Rotor limit. It has been shown, that the E0 strength is relatively high at the shape-phase transitional point and starts to decrease with increasing stiffness and vanishes completely at the Rigid Rotor limit. Additionally the wave functions of the macroscopic collective Confined β-soft rotor model have been compared to those from a microscopic mean field Hamiltonian. Good agreement has been found. The second part of this thesis covers a polarized-proton scattering experiment on the heavy deformed nucleus {sup 154}Sm, that has been performed at the RCNP in Osaka, Japan. Utilizing the method of polarization transfer observables, a separation of spinflip and non-spinflip parts of the cross section has been done. Here, for the first time, the Pygmy Dipole Resonance (PDR) has been identified in the heavy deformed nucleus {sup 154}Sm that appears as a double-hump structure in the E1 response. A possible interpretation of this double-hump structure in terms of a deformation splitting analogously to the Giant Dipole Resonance (GDR) has been given. In case of the spinflip cross section, a broad distribution in the excitation energy range between 6 and 12 MeV has been observed. The distribution and the extracted sum strength are in good accordance with previous experiments.

  17. Low spin structure of 86Se: Confirmation of γ collectivity at N =52

    Science.gov (United States)

    Materna, T.; Urban, W.; Sieja, K.; Köster, U.; Faust, H.; Czerwiński, M.; RzÄ ca-Urban, T.; Bernards, C.; Fransen, C.; Jolie, J.; Regis, J.-M.; Thomas, T.; Warr, N.

    2015-09-01

    The 86Se nucleus has been investigated by γ -ray spectroscopy using an array of Ge detectors placed at the exit of the fission-fragment mass separator Lohengrin of the Institut Laue-Langevin. New transitions have been identified by studying the β decay of 86As. An excitation scheme is proposed and includes a 22+ level at 1399 keV and a possible 3+ level that are well reproduced by shell model calculations with the most recent parametrization. The properties of the excitations indicate a possible onset of γ collectivity in 86Se.

  18. Lifetimes of the low spin states in the superdeformed band of {sup 192}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Lee, I Y; Baktash, C; Cullen, D; Garrett, J D; Johnson, N R; McGowan, F K; Winchell, D F [Oak Ridge National Lab., TN (United States); Yu, C H [Tennessee Univ., Knoxville, TN (United States)

    1992-08-01

    Superdeformed (SD) states with a 2:1 axis ratio have been observed in nuclei in the A = 150, 190, and the actinide regions. These states depopulate into normally deformed (ND) states by gamma decay, but so far the linking transitions have not been observed and the depopulation mechanism is not fully understood. Nuclei in different mass regions decay out at states with different spin (I), excitation energy above the ND yrast line (U) and lifetime {tau}. This variation is due to differences in the nuclear properties such as the barrier penetration probability, the level densities and the gamma transition strength of SD and ND states. One important factor is the competition between the collective E2 decay along the SD band and the statistical decay to the ND states. These transition rates, or the partial lifetimes, can be determined if the lifetime and the intensity of the gamma rays depopulating the SD states are known. (author). 4 refs., 2 tabs., 2 figs.

  19. Physics at low spin in the mass 160 region: the search for tetrahedral shapes

    International Nuclear Information System (INIS)

    Bark, R.A.; Sharpey-Schafer, J.F.; Maliage, S.M.; Madiba, T.E.; Komati, F.S.; Lawrie, E.A.; Lawrie, J.J.; Lindasy, R.; Maine, P.; Mullins, S.M.; Murray, S.H.T.; Ncapayi, N.J.; Ramashidza, T.M.; Smit, F.D.; Vymers, P.

    2010-01-01

    The low-lying, odd-spin negative parity bands in the mass 160 region have been identified as candidates for the rotation of a tetrahedral shape, as they have very weak in-band E2 transitions. We report the observation of such bands in 160 Yb and 154 Gd. They are crossed by 2 quasiparticle bands which allow band mixing calculations to be carried out to derive relative quadrupole moments. However, those studied are not consistent with zero, as required for tetrahedral shape. The aligned angular momenta of the bands suggest an octupole vibrational assignment.

  20. Decay properties of rare earth nuclei at high excitation and low spin

    International Nuclear Information System (INIS)

    Atac, A.

    1989-01-01

    The purpose of this study was to examine the decay pattern of highly excited rare earth nuclei for which the decay process is expected to be governed by statistical laws. The aim was to investigate how good the statistical model describes the nuclear system and to search for possible deviation from it. It is shown that the gamma decay spectra following both the ( 3 He,α) pick-up reactions and the inelastic ( 3 He, 3 He') reactions reveal similar type of bumps. This leads to the conclusion that the bump structures are not a result of a particular reaction mechanism, but that they have a more general origin. The study is mainly devoted to an examination of the nature of the bumps. 22 refs

  1. Electromagnetic properties of low-spin states in 102,104Pd

    International Nuclear Information System (INIS)

    Luontama, M.; Julin, R.; Kantele, J.; Passoja, A.; Trzaska, W.; Baecklin, A.; Jonsson, N.G.; Westerberg, L.

    1985-12-01

    Electromagnetic transitions from low-lying 0 + , 2 + , 4 + and 3 - states in 102 , 104 Pd have been studied with (p,2n) and (p,p) reactions and with Coulomb excitation. The E2 transition probabilities from the 0 3 + state in 102 Pd (13 W.u.) and from the 0 2 + state in 104 Pd (14 W.u.) are somewhat low for two-phonon states. Generally, the E2 transition rates are reasonably well reproduced by the IBA-2 and by the boson-expansion description. The intruding 0 2 + state (tsub(1/2) = 14.3 ns) in 102 Pd is connected to the 2 2 + and 2 3 + states via strong E2 transitions: B(E2;0 2 + →2 2 + )=96+-40 W.u.; B(E2;2 3 + →0 2 + )=17+-8 W.u

  2. Characterization of Lanthanum Ferric Cobaltite doped with Strontium (LSCF) films deposited by spray-pyrolysis for application as cathode in PaCOS-TI; Caracterizacao de filmes de CFLE depositados por spray-pirolise para utilizacao como catodo em PaCOS-TI

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.S.; Guimaraes, V.F.; Paes Junior, H.R. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Lab. de Materiais Avancados], Emails: laryssadsa@yahoo.com.br, valtencyguimaraes@yahoo.com.br, herval@uenf.br

    2010-07-01

    The lanthanum ferric cobaltite doped with strontium (LSCF) is a ceramic material with the perovskite structure that stands out in the field of research for its use as cathode in solid oxide fuel cells at intermediate temperatures (IT-SOFC). The films were synthesized by spray-pyrolysis technique on 8% mol Yttria stabilized zirconia (YSZ) substrates. It was studied the influence of heat treatment temperatures (600-1000 deg C) on the properties of the films under the conditions of treatment during four hours. Samples were tested electrically by measuring the variation of electrical conductivity with temperature, structurally by X-ray diffraction (XRD) and morphologically by scanning electron microscopy (SEM). The films heat treated at 700 deg C for 4 hours showed better performance for application as cathode. (author)

  3. Investigation of low spin resonances in the 12C+12C and 16O+12C systems

    International Nuclear Information System (INIS)

    Uzureau, J.L.; Fieni, J.M.; Cocu, F.; Michaudon, A.

    1979-01-01

    The excitation functions of the 12 C( 12 C,α) 20 Ne and 12 C( 16 O,α) 24 Mg reactions were measured at different angles below the Coulomb barrier. Resonant structures were found at Esub(cm)=5.80 MeV in the 12 C+ 12 C system and at Esub(cm)=6.10 MeV in the 16 O+ 12 C system. From the analysis of angular distributions measured at the previous resonant energies, values of respectively Jsup(π)=0 + and 2 + have been deduced [fr

  4. A low-spin Fe(III) complex with 100-ps ligand-to-metal charge transfer photoluminescence

    DEFF Research Database (Denmark)

    Chabera, Pavel; Liu, Yizhu; Prakash, Om

    2017-01-01

    Transition-metal complexes are used as photosensitizers(1), in light-emitting diodes, for biosensing and in photocatalysis(2). A key feature in these applications is excitation from the ground state to a charge-transfer state(3,4); the long charge-transfer-state lifetimes typical for complexes...

  5. Structure of Os - Pt nuclei and g factors of 186-192Os isotopes at low spins

    International Nuclear Information System (INIS)

    Ansari, A.

    1987-10-01

    Employing a pairing + quadrupole model interaction, especially suitable for the Os - Pt region, the ground state structure of these nuclei is investigated following a selfconsistent Hartree-Fock-Bogolyubov (HFB) approach. Effects of the inclusion of hexadecapole degrees of freedom in the Hamiltonian are also studied. All the osmium isotopes considered here come out to be prolate in shape in the ground state. 186 Pt is triaxial with γ=12 deg. and with the increasing mass number they gradually go over to the oblate shape at A=190 itself. In view of recent experimental data on g factors of osmium isotopes which show interesting variations as a function of mass number as well as spin, we have calculated these following the methods of variation after exact angular momentum projection of axial HFB wave functions and the cranked HFB theory. The observed trend of the variation of g factor at I=2 with the mass number is reproduced with very minor adjustments of the force constants of the Hamiltonian in both the approaches. However, the variation of g factor with spin, which is sensitive to the interplay between collective and the single particle degrees of freedom, can be understood only in the cranking approach. (author). 52 refs, 8 figs, 6 tabs

  6. Iron Fortified Complementary Foods Containing a Mixture of Sodium Iron EDTA with Either Ferrous Fumarate or Ferric Pyrophosphate Reduce Iron Deficiency Anemia in 12- to 36-Month-Old Children in a Malaria Endemic Setting: A Secondary Analysis of a Cluster-Randomized Controlled Trial.

    Science.gov (United States)

    Glinz, Dominik; Wegmüller, Rita; Ouattara, Mamadou; Diakité, Victorine G; Aaron, Grant J; Hofer, Lorenz; Zimmermann, Michael B; Adiossan, Lukas G; Utzinger, Jürg; N'Goran, Eliézer K; Hurrell, Richard F

    2017-07-14

    Iron deficiency anemia (IDA) is a major public health problem in sub-Saharan Africa. The efficacy of iron fortification against IDA is uncertain in malaria-endemic settings. The objective of this study was to evaluate the efficacy of a complementary food (CF) fortified with sodium iron EDTA (NaFeEDTA) plus either ferrous fumarate (FeFum) or ferric pyrophosphate (FePP) to combat IDA in preschool-age children in a highly malaria endemic region. This is a secondary analysis of a nine-month cluster-randomized controlled trial conducted in south-central Côte d'Ivoire. 378 children aged 12-36 months were randomly assigned to no food intervention ( n = 125; control group), CF fortified with 2 mg NaFeEDTA plus 3.8 mg FeFum for six days/week ( n = 126; FeFum group), and CF fortified with 2 mg NaFeEDTA and 3.8 mg FePP for six days/week ( n = 127; FePP group). The outcome measures were hemoglobin (Hb), plasma ferritin (PF), iron deficiency (PF anemia (Hb iron deficiency with or without anemia ( p = 0.068). IDA prevalence sharply decreased in the FeFum (32.8% to 1.2%, p anemia. These data indicate that, despite the high endemicity of malaria and elevated inflammation biomarkers (C-reactive protein or α-1-acid-glycoprotein), IDA was markedly reduced by provision of iron fortified CF to preschool-age children for 9 months, with no significant differences between a combination of NaFeEDTA with FeFum or NaFeEDTA with FePP. However, there was no overall effect on anemia, suggesting most of the anemia in this setting is not due to ID. This trial is registered at clinicaltrials.gov (NCT01634945).

  7. Quantitative spectrographic determination of traces of manganese in ferric oxide

    International Nuclear Information System (INIS)

    Capdevila, C.; Roca, M.

    1968-01-01

    In order to enhance the sensitivity, different electrode types and sweeping substances have been studied. Graphite anodes, with 5 x 2,5, 4 x 4,5, 4 x 8 and 7 x 10 mm crater, as well as CuF 2 , AgCl, ZnO and graphite powder as sweeping materials, have been tested. A JACO-Ebert grating spectrograph and 10 amp. d.c. arc have been employed, choosing the proper exposure times from moving-plate studies. Using 4 x 4,5 mm electrodes and 75% AgCl a detection limit of 0,2 ppm is attainable. (Author) 7 refs

  8. Magnetostructural relationship for μ2-phenoxido bridged ferric dimers.

    Science.gov (United States)

    Yu, Fei; Cao, Zi-Heng; Ge, Jing-Yuan; Sun, Yi-Chen; Ouyang, Zhong-Wen; Zuo, Jing-Lin; Wang, Zhenxing; Kurmoo, Mohamedally

    2017-03-27

    Three Fe(iii) dimers, [Fe 2 (L-H) 2 ]·2CH 3 CN (1), [Fe 2 (L-OCH 3 ) 2 ] (2) and [Fe 2 (L-OC 2 H 5 ) 2 ]·2CH 3 CN (3), containing the pentadentate O,N,N,O,O-donor Schiff-base ligands with variable size pendants, were synthesized and structurally characterized. The three ligands were generated in situ from 2-(iminomethyl)phenol, 2-methoxy-6-(iminomethyl)phenol and 2-ethoxy-6-(iminomethyl)phenol, respectively. All three crystal structures contain centrosymmetric dimers of edge-sharing octahedra of Fe(iii) ions through a pair of μ 2 -phenoxido bridges. The exchange coupling is ferromagnetic for 1 (J = +0.47(1) cm -1 , ∠Fe-O-Fe = 98.02°) and 2 (J = +0.86(1) cm -1 , ∠Fe-O-Fe = 97.17°), but antiferromagnetic for 3 (J = -0.72(1) cm -1 , ∠Fe-O-Fe = 98.53°), which are correlated by high-field electron paramagnetic resonance revealing moderate magneto-anisotropy of D = -0.24(3) cm -1 , E = 0.08(1) cm -1 for 1, D = -0.38(1) cm -1 , E = 0.11(1) cm -1 for 2, and D = 0.30(3) cm -1 , E = 0.02(1) cm -1 for 3. The exchange couplings were further estimated by DFT calculations, which gave the finest Fe-O-Fe angle of 97.83° for the ferromagnetic-antiferromagnetic crossover.

  9. Obligatory reduction of ferric chelates in iron uptake by soybeans.

    Science.gov (United States)

    Chaney, R L; Brown, J C; Tiffin, L O

    1972-08-01

    The contrasting Fe(2+) and Fe(3+) chelating properties of the synthetic chelators ethylenediaminedi (o-hydroxyphenylacetate) (EDDHA) and 4,7-di(4-phenylsulfonate)-1, 10-phenanthroline (bathophenanthrolinedisulfonate) (BPDS) were used to determine the valence form of Fe absorbed by soybean roots supplied with Fe(3+)-chelates. EDDHA binds Fe(3+) strongly, but Fe(2+) weakly; BPDS binds Fe(2+) strongly but Fe(3+) weakly. Addition of an excess of BPDS to nutrient solutions containing Fe(3+)-chelates inhibited soybean Fe uptake-translocation by 99+%; [Fe(II) (BPDS)(3)](4-) accumulated in the nutrient solution. The addition of EDDHA caused little or no inhibition. These results were observed with topped and intact soybeans. Thus, separation and absorption of Fe from Fe(3+)-chelates appear to require reduction of Fe(3+)-chelate to Fe(2+)-chelate at the root, with Fe(2+) being the principal form of Fe absorbed by soybean.

  10. Uranium potentiometer determination in inactive atmosphere with ferric sulfate

    International Nuclear Information System (INIS)

    Fernandez Cellini, R.; Alonso Lopez, J.

    1956-01-01

    Potenciometric titration of Uranium with (SO 4 ) 3 Fe 2 , using Cd as reducing agent has been studied; acidity and sensibility of this reaction are fixed. This method yields good results for uranite group, removing previously phosphate by ion exchange with Amberlite IR-120. (Author)

  11. Comparative Evaluation of Ankaferd Blood Stopper, Ferric Sulfate ...

    African Journals Online (AJOL)

    2016-07-24

    Jul 24, 2016 ... 2017 Nigerian Journal of Clinical Practice | Published by Wolters Kluwer ‑ ... pulpotomy treatment in primary teeth,[1-6] researches which ... Restorable teeth following completion of procedure. ... pulp tissue was completely removed with low-speed .... radiographic failure was observed in seven teeth from.

  12. Comparative Evaluation of Ankaferd Blood Stopper, Ferric Sulfate ...

    African Journals Online (AJOL)

    2016-07-24

    Jul 24, 2016 ... with extensive caries but without evidence of radicular pathology. The coronal pulp is amputated, and the ... Caries lesion should be approximating to the pulp. • No interradicular or periapical radiolucency or pulp ..... be used in the occlusal cavity. Holan et al.[24] assessed the success of SSC and AM ...

  13. assessing the efficacy of assessing the efficacy of dissolved ferric

    African Journals Online (AJOL)

    eobe

    The drying bed was funnel-shaped with 420mm surface diameter, 340mm vertical depth fitted with a. 25 mm drain pipe and a gauze to prevent the sand from flowing out from the opening at the base. The sand was 75mm thick while the sewage sludge occupied a thickness of 200mm. This experiment lasted for six days.

  14. Spin-crossover in [Fe(3-bpp)2][BF4]2 in different solvents--a dramatic stabilisation of the low-spin state in water.

    Science.gov (United States)

    Barrett, Simon A; Kilner, Colin A; Halcrow, Malcolm A

    2011-12-07

    The temperature of spin-crossover in [Fe(3-bpp)(2)][BF(4)](2) (3-bpp = 2,6-di{pyrazol-3-yl}pyridine) tends to increase in associating solvents. In particular, T(½) shifts to 60-70 K higher temperature in water compared to organic solvents.

  15. Electric-Field Effects in ESR Spectrum of Low-Spin Center Ni3+ in KTaO3 Crystals (Preprint)

    National Research Council Canada - National Science Library

    Sochava, L. S; Basun, S. A; Bursian, V. E; Razdobarin, A. G; Evans, Dean R

    2007-01-01

    ...+ was studied in KTaO3 single crystals. Orientation of the centers as well as splitting of the resonance lines was found resulting from the external E-field interaction with the electric dipole moment of the center...

  16. Influence of sex hormones on relative quantities of multiple species of cytochrome P-450 in rat liver microsomes

    International Nuclear Information System (INIS)

    Fujita, S.; Peisach, J.; Chevion, M.; Hebrew Univ., Jerusalem

    1981-01-01

    EPR spectra of rat liver microsomes from male, female and hormonally-treated castrated hepatectomized rats were studied. The spectra, especially in the region of gsub(max) suggested a heterogeneity of local environments of the low spin ferric heme indicative of multiple structures for cytochrome P-450. Certain features in the spectrum correlated with sexual differences. It is suggested that the changes in the relative amplitudes of the EPR features represent differences in the relative abundance of the individual proteins in the mixture that, in turn, are related to the sexual differences of metabolic patterns for reactions catalyzed by cytochrome P-450. (author)

  17. Electronic structure of transition metal-isocorrole complexes: A first quantum chemical study

    NARCIS (Netherlands)

    van Oort, B; Tangen, E; Ghosh, A.

    2004-01-01

    DFT calculations indicate that the broad electronic-structural features of metalloisocorroles are rather similar to those of analogous metallocorroles. Thus, like their corrole analogues, many metalloisocorroles feature substantially non-innocent ligands. Another key point is that both corroles and

  18. Magnetic resonance imaging of transfusional hemosiderosis complicating thalassemia major

    International Nuclear Information System (INIS)

    Brasch, R.C.; Wesbey, G.E.; Gooding, C.A.; Koerper, M.A.

    1984-01-01

    Tissue deposits of hemosiderin, a paramagnetic iron-protein complex, resulted in marked abnormalities of magnetic resonance (MR) spin-echo signal intensity within the viscera of three children with transfusional hemosiderosis and thalassemia major. In all patients the liver and bone marrow demonstrated abnormally low spin-echo intensities and the kidneys and muscles had abnormally high intensities. These observations correlate with in vitro MR observation of ferric (Fe +3 ) solutions, in which concentrations of ferric salts greater than 20 mmol yielded higher intensities than did water alone. MR imaging is sensitive to the tissue deposition of hemosiderin, and MR intensity appears to provide a rough measure of the amount of iron deposited

  19. The passivation of calcite by acid mine water. Column experiments with ferric sulfate and ferric chloride solutions at pH 2

    Energy Technology Data Exchange (ETDEWEB)

    Soler, Josep M. [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain)], E-mail: jsoler@ija.csic.es; Boi, Marco [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Mogollon, Jose Luis [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Instituto de Ciencias de la Tierra, Universidad Central de Venezuela, Caracas 1020-A (Venezuela, Bolivarian Republic of); Cama, Jordi; Ayora, Carlos [Institute of Earth Sciences ' Jaume Almera' (CSIC), Lluis Sole i Sabaris s/n, 08028 Barcelona, Catalonia (Spain); Institute of Environmental Assessment and Water Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia (Spain); Nico, Peter S.; Tamura, Nobumichi; Kunz, Martin [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2008-12-15

    Column experiments, simulating the behavior of passive treatment systems for acid mine drainage, have been performed. Acid solutions (HCl or H{sub 2}SO{sub 4}, pH 2), with initial concentrations of Fe(III) ranging from 250 to 1500 mg L{sup -1}, were injected into column reactors packed with calcite grains at a constant flow rate. The composition of the solutions was monitored during the experiments. At the end of the experiments (passivation of the columns), the composition and structure of the solids were measured. The dissolution of calcite in the columns caused an increase in pH and the release of Ca into the solution, leading to the precipitation of gypsum and Fe-oxyhydroxysulfates (Fe(III)-SO{sub 4}-H{sup +} solutions) or Fe-oxyhydroxychlorides (Fe(III)-Cl-H{sup +} solutions). The columns worked as an efficient barrier for some time, increasing the pH of the circulating solutions from 2 to {approx}6-7 and removing its metal content. However, after some time (several weeks, depending on the conditions), the columns became chemically inert. The results showed that passivation time increased with decreasing anion and metal content of the solutions. Gypsum was the phase responsible for the passivation of calcite in the experiments with Fe(III)-SO{sub 4}-H{sup +} solutions. Schwertmannite and goethite appeared as the Fe(III) secondary phases in those experiments. Akaganeite was the phase responsible for the passivation of the system in the experiments with Fe(III)-Cl-H{sup +} solutions.

  20. The influence of Ferric ion contamination on the solid polymer electrolyte water electrolysis performance

    International Nuclear Information System (INIS)

    Wang, Xunying; Zhang, Linsong; Li, Guangfu; Zhang, Geng; Shao, Zhi-Gang; Yi, Baolian

    2015-01-01

    Highlights: • The cathode possesses higher tolerance for the Fe 3+ contamination than the anode. • Fe 3+ are mostly reduced to Fe 2+ rather than occur underpotential deposition. • Increased electrolysis voltage was mainly attributed to ohmic overpotential. • Voltage lags behind current for minutes in the multi-current-step test. • Poisoned electrolyser is mostly recovered by 0.5 M H 2 SO 4 solution treatment for 13 h. - Abstract: Fe 3+ is a sort of common metal ion contaminant for the solid polymer electrolyte (SPE) water electrolyser. In this paper, the effect of Fe 3+ on the performance of SPE water electrolyser has been investigated by both in-situ and ex-situ characterizations. The electron probe microanalysis and ultraviolet test results showed that Fe 3+ could migrate from the anode to the cathode and mostly be reduced to Fe 2+ in the cathode rather than occurred underpotential deposition as described in the previous report. The in-situ dynamic contamination test showed that the anode voltage increased sharply as soon as the Fe 3+ was fed into the anode, while the cathode voltage kept constant until the contamination time was over 30 minutes, indicating the higher tolerance of the cathode than the anode for the Fe 3+ contamination. The calculation results based on the electrochemistry impedance spectroscopy test results revealed that the striking increase of the electrolysis voltage was mainly attributed to the ohmic overpotential, which was due to the replacement of H + by Fe 3+ in the Nafion resin. Interestingly, the voltage lagged behind the current for several minutes in the multi-current-step test for the contaminated electrolyser, which phenomenon may be used for judging whether the SPE water electrolyser performance degradation is due to the metal ions contamination. Furthermore, recovery strategy has been developed, and it was found that the contaminated electrolyser could be mostly recovered by 0.5 M H 2 SO 4 solution treatment for 13 h

  1. Ferric minerals and organic matter change arsenic speciation in copper mine tailings.

    Science.gov (United States)

    Wang, Peng; Liu, Yunjia; Menzies, Neal W; Wehr, J Bernhard; de Jonge, Martin D; Howard, Daryl L; Kopittke, Peter M; Huang, Longbin

    2016-11-01

    Arsenic (As) is commonly associated with Cu ore minerals, with the resultant risk that As can be released offsite from mine tailings. We used synchrotron-based fluorescence X-ray absorption near-edge spectroscopy (XANES) imaging to provide in situ, laterally-resolved speciation of As within tailings which differed in magnetite content (5-12%) and organic matter content (0-5%). Although the total As content was lower in tailings with low magnetite (LM), the soluble (pore water) As was actually 7-times higher in LM tailings than in high magnetite (HM) tailings. Additionally, amendment with 5% sugarcane mulch residues (SMR) (for revegetation) further increased soluble As due to the dissolution and oxidation of arsenopyrite or orpiment. Indeed, in HM tailings, arsenopyrite and orpiment initially accounted for 88% of the total As, which decreased to 48% upon the addition of SMR - this being associated with an increase in As V -ferrihydrite from 12% to 52%. In LM tailings, the pattern of As distribution and speciation was similar, with As as As V -ferrihydrite increasing from 57% to 75% upon the addition of SMR. These findings indicate that changes in ore processing technology, such as the recovery of magnetite could have significant environmental consequences regarding the As mobilisation and transformation in mine tailings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Minimisation of higher order harmonics for large aperture super-ferric quadrupole magnet

    International Nuclear Information System (INIS)

    Dutta, Atanu; Sharma, P.R.; Dey, M.K.; Bhunia, U.; Nandy, C.; Roy, S.; Pal, G.; Mallik, C.

    2011-01-01

    We have analysed the magnetic field of finite length (effective length of 1200 mm), large bore (pole radius of 350 mm) superconducting quadrupole magnets for use in Low Energy Branch of Super FRS with the program TOSCA. In particularly we have tried to minimize the 12-pole and 20-pole components, which would contribute to geometric aberrations. At the same time we have tried to keep the gradient field uniformity at reference radius 300 mm within ±8.0E-04. (author)

  3. Valorisation of ferric sewage sludge ashes: Potential as a phosphorus source

    DEFF Research Database (Denmark)

    Guedes, Paula; Couto, Nazare; Ottosen, Lisbeth M.

    2016-01-01

    Sewage sludge ashes (SSA), although a waste, contain elements with socio-economic and environmental potential that can be recovered. This is the case of phosphorus (P). SSA from two Danish incinerators were collected during two years and characterized. The sampling was done immediately after...... incineration (fresh SSA) or from an outdoor deposit (deposited SSA). Although morphology and mineral composition were similar, physico-chemical and metal concentration differences were found between incinerator plants and sampling periods. No differences were observed between deposited and fresh SSA, except...... for the parameters directly influenced by disposal conditions (e.g. moisture content). All the SSAs had high concentrations of P (up to 16 wt%), but they all exceeded Danish EPA Cd and Ni thresholds for direct application at agricultural soil.Fresh and deposited SSA were acid washed aiming P extraction, achieving 50...

  4. Current generation in microbial electrolysis cells with addition of amorphous ferric hydroxide, Tween 80, or DNA

    KAUST Repository

    Ren, Lijiao

    2012-11-01

    Iron-oxide nanoparticles and the Tween 80 have previously been shown to improve power generation in microbial fuel cells (MFCs), presumably by improving electron transfer from the bacteria to the anode. We examined whether several chemicals would affect current production in single-chamber microbial electrolysis cells (MECs), where hydrogen gas is produced at the cathode, using mixed cultures and Geobacter sulfurreducens. Tween 80 did not increase the current. Fe(OH) 3 addition increased the maximum current density of both the mixed cultures (from 6.1 ± 0.9 A/m 2 to 8.8 ± 0.3 A/m 2) and pure cultures (from 4.8 ± 0.5 A/m 2 to 7.4 ± 1.1 A/m 2). Improved current production was sustained even after iron was no longer added to the medium. It was demonstrated that increased current resulted from improved cathode performance. Analysis using electrochemical impedance spectroscopy (EIS) showed that the iron primarily reduced the diffusion resistances of the cathodes, and scanning electron microscopy (SEM) images showed the formation of highly porous structures on the cathode. The addition of DNA also did not improve MEC or MFC performance. These results demonstrated that among these treatments only Fe(OH) 3 addition was a viable method for enhancing current densities in MECs, primarily by improving cathode performance. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.

  5. A Moessbauer study on the interaction between biomolecular lipid membranes and ferric ferrous ions

    International Nuclear Information System (INIS)

    Karvaly, B.; Badinka, C.; Keszthelyi, L.; Erdei, L.

    1975-01-01

    The results of Moessbauer experiments made on liposome systems of a large specific area are presented. In the study lecithin was used as a membrane-forming material. The measurements were carried out on frozen liposome systems, at various 57 Fe/lipid concentration ratios, pH values and temperatures. Since the presence of liposomes had no noticeable influence on the Moessbauer spectra of Fe 2+ ions, only lecithin Fe 3+ systems were considered. Moessbauer spectra in case of Fe 3+ solutions with lecithin showed marked quadrupole splitting (exhibiting an anomalous temperature dependence) which is not shown in case of pure Fe 3+ solution. (Z.S.)

  6. Use of ferric- and ferrous-salts in liquid waste treatment processes

    International Nuclear Information System (INIS)

    Efremenkov, V.M.; Toropov, I.G.; Toropova, V.V.; Satsukevich, V.M.; Davidov, J.P.; Jabrodsky, V.N.; Prokshin, N.E.

    1995-01-01

    Treatment of spent decontamination solutions is the most complicated task in the whole problem of management of liquid radioactive waste, because quite often they have complex compositions, which makes it difficult to find for them effective and non-expensive treatment technology. New methods of treatment of such a waste is proposed based on use of specific sorption ability of ferro- and ferri-species in solution. These species are often present in solution as the by-products, and in combination with other components of decontamination solution they can be used as initial substances for synthesis of valuable sorbents directly in treating solution. Using specific compositions and conditions in solution, it is possible to make liquid waste treatment process more effective and less expensive. Particular examples of this process is presented in this work

  7. Structure Function Analysis of the Ferric Uptake Regulator (Fur) of Helicobacter pylori

    Science.gov (United States)

    2010-03-17

    through the gastric lumen, through the mucus layer to the underlying epithelial cells; thus, the flagella are essential for colonization (66). This...organism also produces a mucinase to help breakdown the mucus layer in the stomach (181). Once through the mucus layer , approximately 20% of the...combating pH-related stress. This is primarily managed through the production of urease , an essential enzyme, which generates ammonia through the

  8. Methane-induced Activation Mechanism of Fused Ferric Oxide-Alumina Catalysts during Methane Decomposition

    KAUST Repository

    Reddy Enakonda, Linga

    2016-06-27

    Activation of Fe2O3-Al2O3 with CH4 (instead of H2) is a meaningful method to achieve catalytic methane decomposition (CMD). This reaction of CMD is more economic and simple against commercial methane steam reforming (MSR) as it produces COx-free H2. In this study, for the first time, structure changes of the catalyst were screened during CH4 reduction with time on stream. The aim was to optimize the pretreatment conditions through understanding the activation mechanism. Based on results from various characterization techniques, reduction of Fe2O3 by CH4 proceeds in three steps: Fe2O3→Fe3O4→FeO→Fe0. Once Fe0 is formed, it decomposes CH4 with formation of Fe3C, which is the crucial initiation step in the CMD process to initiate formation of multiwall carbon nanotubes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Formation of ferric flocks for the removal of Zn and Cu from dockyard wastewater

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Arevalo, Edurado; Stichnothe, Heinz

    2006-01-01

    Wastewater from wash down of boat hulls contains typically Cu, Zn and organometallic biocides, e.g. tributyltin (TBT). In some cases this wastewater is led directly into the marine system. In the present paper a cheap flocculation method (iron flocculants) for removal of Cu and Zn from the wastew......Wastewater from wash down of boat hulls contains typically Cu, Zn and organometallic biocides, e.g. tributyltin (TBT). In some cases this wastewater is led directly into the marine system. In the present paper a cheap flocculation method (iron flocculants) for removal of Cu and Zn from...

  10. Methane-induced Activation Mechanism of Fused Ferric Oxide-Alumina Catalysts during Methane Decomposition

    KAUST Repository

    Reddy Enakonda, Linga; Zhou, Lu; Saih, Youssef; Ould-Chikh, Samy; Lopatin, Sergei; Gary, Daniel; Del-Gallo, Pascal; Basset, Jean-Marie

    2016-01-01

    Activation of Fe2O3-Al2O3 with CH4 (instead of H2) is a meaningful method to achieve catalytic methane decomposition (CMD). This reaction of CMD is more economic and simple against commercial methane steam reforming (MSR) as it produces COx-free H2

  11. Efficacy of a low-dose ferric-EDTA in reducing iron deficiency ...

    African Journals Online (AJOL)

    Iron deficiency anaemia is a public health problem in Tanzania especially among children under the age of five years. In malaria holoendemic areas, control of anaemia by supplementation with iron has been reported to increase serious adverse events. The World Health Organization recommends that, programs to control ...

  12. Riboflavin Biosynthesis Is Associated with Assimilatory Ferric Reduction and Iron Acquisition by Campylobacter Jejuni.

    NARCIS (Netherlands)

    Gaskin, D.J.H.; Holmes, K.; Mulholland, F.; Wells, J.

    2007-01-01

    One of the pathways involved in the acquisition of the essential metal iron by bacteria involves the reduction of insoluble Fe3+ to soluble Fe2+, followed by transport of Fe2+ to the cytoplasm. Flavins have been implicated as electron donors in this poorly understood process. Ferrous iron uptake is

  13. Polynuclear Iron-Oxo/Hydroxy Complexes of Ketoacidoximate Ligands: Synthesis, Structures and Conversion to Ferric Oxide

    KAUST Repository

    Davaasuren, Bambar

    2017-06-13

    The polynuclear iron-oxo/hydroxy complexes containing ketoacidoximate ligands described in this report are [Fe3(μ3-O){O2C-C(C6H5)=NOCH3}6(py)3] (1) (py=pyridine), [Fe2(μ3-O){O2C-C(CH2-C6H5)=NO}2(H2O)(CH3OH)]2 (2) and [{Fe(μ2-OH)(O2C-C(CH3)=NO)}(dmso)]6 (3) (dmso=dimethyl sulfoxide). 1–3 are isolated from the reaction of Fe(NO3)3⋅9H2O and in situ generated anions of ketoacidoximate ligand [(HO2C-C(R1)=NOR2), where R1=CH3, C6H5 and CH2-C6H5; R2=H or CH3] in H2O, followed by crystallization in donor solvents. 1–3 undergo thermal decomposition above 200 °C and form crystalline α-Fe2O3 at 600 °C.

  14. Sedimentibacter sp. With corrosive capability, Ferric-reducing, isolated from an oil separation tank

    International Nuclear Information System (INIS)

    Lopez-Jimenez, G.; Loera, O.; Ramirez, F.; Monroy, O.; Fernandez-Linares, L. C.

    2009-01-01

    Bio corrosion is a common problem in oil and gas industry facilities. characterization of the microbial populations responsible for bio corrosion and the interactions between different microorganisms with metallic surfaces is required in order to implemented efficient monitoring and control strategies. (Author)

  15. Arsenic removal by coagulation using ferric chloride and chitosan from water

    Directory of Open Access Journals (Sweden)

    Farid Hesami

    2013-01-01

    Conclusions: Chitosan as natural coagulant aid improved arsenic removal efficiency by coagulation process using FeCl 3 . This method can be used for regions with drinking water contaminated with initial arsenic concentration less than 1 000 μg/l.

  16. A novel dansyl-based fluorescent probe for highly selective detection of ferric ions.

    Science.gov (United States)

    Yang, Min; Sun, Mingtai; Zhang, Zhongping; Wang, Suhua

    2013-02-15

    A novel dansyl-based fluorescent probe was synthesized and characterized. It exhibits high selectivity and sensitivity towards Fe(3+) ion. This fluorescent probe is photostable, water soluble and pH insensitive. The limit of detection is found to be 0.62 μM. These properties make it a good fluorescent probe for Fe(3+) ion detection in both chemical and biological systems. Spike recovery test confirms its practical application in tap water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Study of the dehydroxylation in the hydrated ferric oxide named limonite

    International Nuclear Information System (INIS)

    Palacios, P.R.; Bustamante, A.; De Los Santos Valladares, L.; Gonzalez, J.C.

    2012-01-01

    We completed the previous characterization of the compound named limonite (FeO[OH].nH 2 O) with the analysis of thermal behavior at temperatures from ambient to 1000 o C, as well as their chemical analysis through the measurements of energy dispersive X-ray and the study in the infrared region in energy range from 600 to 4000 cm -1 . The results show a sharp endotherm peak around 264 o C, it corresponds to the structure change of the orthorhombic goethite (Pbnm) to rhombohedra hematite (R3c). Moreover, we found three inflexion points in the percentage of mass loss at temperatures of 50, 190 and 290 o C. These changes are closely related to the deshydroxylation of limonite to goethite, α-FeO(OH), phases and subsequently to hematite, α-Fe 2 O 3 . (author).

  18. Possibility of sludge conditioning and dewatering with rice husk biochar modified by ferric chloride.

    Science.gov (United States)

    Wu, Yan; Zhang, Panyue; Zhang, Haibo; Zeng, Guangming; Liu, Jianbo; Ye, Jie; Fang, Wei; Gou, Xiying

    2016-04-01

    Rice husk biochar modified by FeCl3 (MRB-Fe) was used to enhance sludge dewaterability in this study. MRB-Fe preparation conditions and dosage were optimized. Mechanisms of MRB-Fe improving sludge dewaterability were investigated. The optimal modification conditions were: FeCl3 concentration, 3mol/L; ultrasound time, 1h. The optimal MRB-Fe dosage was 60% DS. Compared with raw sludge, the sludge specific resistance to filtration (SRF) decreased by 97.9%, the moisture content of sludge cake decreased from 96.7% to 77.9% for 6min dewatering through vacuum filtration under 0.03MPa, the SV30% decreased from 96% to 60%, and the net sludge solids yield (YN) increased by 28 times. Positive charge from iron species on MRB-Fe surface counteracted negative charge of sludge flocs to promote sludge settleability and dewaterability. Meanwhile, MRB-Fe kept a certain skeleton structure in sludge cake, making the moisture pass through easily. Using MRB-Fe, therefore, for sludge conditioning and dewatering is promising. Copyright © 2016. Published by Elsevier Ltd.

  19. Super and ferric: the first HL-LHC component is ready

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Although the actual installation phase in the tunnel will only start in 2024, the first magnet – a sextupole – of the High-Luminosity LHC (HL-LHC) is ready and working according to specifications. This first component is also rather unique as, unlike the superconducting magnets currently used in the LHC, it relies on a “superferric” heart.   An expert in the LASA Laboratory (INFN Milan, Italy) works on assembling the first sextupole corrector of the HL-LHC. (Image: INFN Milan) Although the name might sound completely unfamiliar, superferric magnets were first proposed in the 1980s as a possible solution for high-energy colliders. However, many technical problems had to be overcome before the use of superferric magnets could become a reality. In its final configuration, the HL-LHC will have 36 superferric corrector magnets, of which 4 will be quadrupoles, 8 sextupoles and 24 higher order magnets. In superferric (or “iron-dominated”) magne...

  20. Current generation in microbial electrolysis cells with addition of amorphous ferric hydroxide, Tween 80, or DNA

    KAUST Repository

    Ren, Lijiao; Tokash, Justin C.; Regan, John M.; Logan, Bruce E.

    2012-01-01

    the maximum current density of both the mixed cultures (from 6.1 ± 0.9 A/m 2 to 8.8 ± 0.3 A/m 2) and pure cultures (from 4.8 ± 0.5 A/m 2 to 7.4 ± 1.1 A/m 2). Improved current production was sustained even after iron was no longer added to the medium

  1. Study of dosimetric systems-ferrous sulfate-ferric sulfate, glass slides and dyed aqueous solutions

    International Nuclear Information System (INIS)

    Fernandes, L.

    1979-01-01

    The effect of some variables which can effect the preparation of the ferrous sulfate used as dosimetric solution has been studied. Among these variables the purity of the water used for the preparation of the solution and the presence (or absence) of oxygen in the dosimetric solution were considered. The dose rate distribution according to the transverse and longitudinal sections of the Co 60 irradiator was studied experimentally, using the dosimetric solution, and theoretically, using a computer program (KIFE). The results obtained with the ferrous sulface dosimetric solution were used as reference for the study of the application of EM and MSG glass slide as a dosimetric system. For this purpose the effects of the weakening of the coloration induced in the glass by gamma rays (Co 60 ) and the relationship between the absorbed dose of radiation and the ratio between the variation in absorbation value and the thickness of the glass irradiated, were studied. A study was also made of the use of the dye indicators bromothymol-blue, methyl-orange, Congo-red, neutral-red and p-nitrophenol, in aqueous solution, for radiation dose measurements. The bleaching of each indicator solution, under gamma-radiation (Co 60 ) was studied in oxygen and nitrogen atmospheres.(Author) [pt

  2. Tuning of the charge in octahedral ferric complexes based on pyridoxal-N-substituted thiosemicarbazone ligands

    NARCIS (Netherlands)

    Tido, Eddy W. Yemeli; Faulmann, Christophe; Roswanda, Robby; Meetsma, Auke; van Koningsbruggen, Petra J.

    2010-01-01

    Four novel mononuclear coordination compounds namely: [Fe(Hthpy)(2)](SO(4))(1/2)center dot 3.5H(2)O 1, [Fe(Hthpy)(2)]NO(3)center dot 3H(2)O 2, [Fe(H(2)mthpy)(2)](CH(3)C(6)H(4)SO(3))(3)center dot CH(3)CH(2)OH 3 and [Fe(Hethpy)(ethpy)]center dot 8H(2)O 4, (H(2)thpy = pyridoxalthiosemicarbazone,

  3. Forbidden transitions in the EPR spectrum of the ferric ion cubic symmetry in magesium oxide

    Energy Technology Data Exchange (ETDEWEB)

    de Biasi, R S [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

    1979-03-01

    The spectrum of the ..delta..m /sub s/=2 transitions of Fe/sup 3 +/ in cubic symmetry sites in MgO has been measured at 9.25GHz. The orientation dependence of the transitions is found to be consistent with a spin Hamiltonian of cubic symmetry with g=2.0037(isotropic), a=0.0205/sup +/-0.00005 cm/sup -1/.

  4. Alanine dosimetry using a spectrophotometric ferric-xylenol orange complex readout

    International Nuclear Information System (INIS)

    Laere, K. van; Buysse, J.; Berkvens, P.

    1989-01-01

    The spectrophotometric dosimetric method using the indirect oxidation of ferrous ions after dissolution of irradiated DL-and L-alanine has been thoroughly investigated with respect to its composition, read-out procedure and dose-response. Optimal concentration of 0.10 N H 2 SO 4 , 0.2 mM xylenol orange and 0.2 mM Fe 2+ were found, giving an absorption maximum at 547 nm. Standardization of chemical processing procedures allows a reproducibility better than 0.5%. The useful dose range has been extended to 0.03-12 kGy by means of slightly different read-out procedure. The quantitative concept of ''indirect yield'', G id , was introduced for this procedure as a measure of the indirect oxidation capacity of the radicals. It was found to be G id,0 (Fe 3+ ) 7.1 ions/100 eV transferred into the alanine. The spectrophotometric readout combines the highly advantageous use of alanine as a dosemeter with the straightforwardness, accuracy and low costs of the chemical procedure. (author)

  5. Biological activity of Fe(III) aquo-complexes towards ferric chelate reductase (FCR).

    Science.gov (United States)

    Escudero, Rosa; Gómez-Gallego, Mar; Romano, Santiago; Fernández, Israel; Gutiérrez-Alonso, Ángel; Sierra, Miguel A; López-Rayo, Sandra; Nadal, Paloma; Lucena, Juan J

    2012-03-21

    In this study we have obtained experimental evidence that confirms the high activity of aquo complexes III and IV towards the enzyme FCR, responsible for the reduction of Fe(III) to Fe(II) in the process of iron acquisition by plants. The in vivo FCR assays in roots of stressed cucumber plants have shown a higher efficiency of the family of complexes III and a striking structure-activity relationship with the nature of the substituent placed in a phenyl group far away from the metal center. The results obtained in this work demonstrate that all the aquo compounds tested interact efficiently with the enzyme FCR and hence constitute a new concept of iron chelates that could be of great use in agronomy.

  6. Polynuclear Iron-Oxo/Hydroxy Complexes of Ketoacidoximate Ligands: Synthesis, Structures and Conversion to Ferric Oxide

    KAUST Repository

    Davaasuren, Bambar; Khanderi, Jayaprakash; Rothenberger, Alexander

    2017-01-01

    The polynuclear iron-oxo/hydroxy complexes containing ketoacidoximate ligands described in this report are [Fe3(μ3-O){O2C-C(C6H5)=NOCH3}6(py)3] (1) (py=pyridine), [Fe2(μ3-O){O2C-C(CH2-C6H5)=NO}2(H2O)(CH3OH)]2 (2) and [{Fe(μ2-OH)(O2C-C(CH3)=NO

  7. Analysis of a Ferric Uptake Regulator (Fur) Mutant ofDesulfovibrio vulgaris Hildenborough

    Energy Technology Data Exchange (ETDEWEB)

    Bender, Kelly S.; Yen, Huei-Che Bill; Hemme, Christopher L.; Yang, Zamin K.; He, Zhili; He, Qiang; Zhou, Jizhong; Huang, Katherine H.; Alm, Eric J.; Hazen, Terry C.; Arkin, Adam P.; Wall, Judy D.

    2007-09-21

    Previous experiments examining the transcriptional profileof the anaerobe Desulfovibrio vulgaris demonstrated up-regulation of theFur regulon in response to various environmental stressors. To test theinvolvement of Fur in the growth response and transcriptional regulationof D. vulgaris, a targeted mutagenesis procedure was used for deletingthe fur gene. Growth of the resulting ?fur mutant (JW707) was notaffected by iron availability, but the mutant did exhibit increasedsensitivity to nitrite and osmotic stresses compared to the wild type.Transcriptional profiling of JW707 indicated that iron-bound Fur acts asa traditional repressor for ferrous iron uptake genes (feoAB) and othergenes containing a predicted Fur binding site within their promoter.Despite the apparent lack of siderophore biosynthesis genes within the D.vulgaris genome, a large 12-gene operon encoding orthologs to TonB andTolQR also appeared to be repressed by iron-bound Fur. While other genespredicted to be involved in iron homeostasis were unaffected by thepresence or absence of Fur, alternative expression patterns that could beinterpreted as repression or activation by iron-free Fur were observed.Both the physiological and transcriptional data implicate a globalregulatory role for Fur in the sulfate-reducing bacterium D.vulgaris.

  8. Effect of ferrous/ferric ions molar ratio on reaction mechanism for ...

    Indian Academy of Sciences (India)

    Wintec

    Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan. MS received 25 ... methods, a mixed aqueous solution of Fe. 2+ ... (Quantum Design model MPMS) at a magnetic field of. 100 Oe ...

  9. Quinoline-substituted Zinc(II) phthalocyanine for the dual detection of ferric and zinc ions

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ankush [Lyallpur Khalsa College of Engineering, Jalandhar (India); Kim, A Rong [Dong-A University, Busan (Korea, Republic of); Kim, Kyung Sub; Na, Kun [The Catholic University, Seoul (Korea, Republic of); Choi, Myung Seok [Konkuk University, Seoul (Korea, Republic of); Park, Jong S. [Pusan National University, Busan (Korea, Republic of)

    2015-09-15

    Here we present the synthesis and properties of quinoline-substituted zinc(II) phthalocyanine, Zn[Pc(O-QN){sub 4} ]. Zn[Pc(O-QN){sub 4} ] can function as a highly selective chemosensor against Fe{sup 3+} and Zn{sup 2+} ions, exhibiting efficient fluorescence quenching and enhancement, respectively. Various characterization techniques were employed to investigate the intermolecular interactions of Zn[Pc(O-QN){sub 4} ] with metal ions. A double-electron exchange and a forbidden photoinduced electron transfer behavior in Zn[Pc(O-QN){sub 4} ] were attributed to such opposite responses. Furthermore, by taking advantage of selectivity, we successfully employed Zn[Pc(O-QN)-4 ] to stain and record confocal fluorescence microscopy images of Chang liver cells in the presence of metal ions.

  10. 76 FR 17556 - Sodium Ferric Ethylenediaminetetraacetate; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-03-30

    ..., flavored milk, and fruit-flavored beverages (Ref. 2), as well as soy, fish, teriyaki, and hoisin sauces... synopses of the study results can be found in the risk assessment and Biopesticides Registration Action... Assessment Data Requirements 1. Acute toxicity. Tier I acute toxicity studies of technical grade sodium...

  11. Perianth bottom-specific blue color development in Tulip cv. Murasakizuisho requires ferric ions.

    Science.gov (United States)

    Shoji, Kazuaki; Miki, Naoko; Nakajima, Noriyuki; Momonoi, Kazumi; Kato, Chiharu; Yoshida, Kumi

    2007-02-01

    The entire flower of Tulipa gesneriana cv. Murasakizuisho is purple, except the bottom, which is blue. To elucidate the mechanism of the different color development in the same petal, we prepared protoplasts from the purple and blue epidermal regions and measured the flavonoid composition by HPLC, the vacuolar pH by a proton-selective microelectrode, and element contents by the inductively coupled plasma (ICP) method. Chemical analyses revealed that the anthocyanin and flavonol compositions in both purple and blue colored protoplasts were the same; delphinidin 3-O-rutinoside (1) and major three flavonol glycosides, manghaslin (2), rutin (3) and mauritianin (4). The vacuolar pH values of the purple and blue protoplasts were 5.5 and 5.6, respectively, without any significant difference. However, the Fe(3+) content in the blue protoplast was approximately 9.5 mM, which was 25 times higher than that in the purple protoplasts. We could reproduce the purple solution by mixing 1 with two equimolar concentrations of flavonol with lambda(vismax) = 539 nm, which was identical to that of the purple protoplasts. Furthermore, addition of Fe(3+) to the mixture of 1-4 gave the blue solution with lambda(vismax) = 615 nm identical to that of the blue protoplasts. We have established that Fe(3+) is essential for blue color development in the tulip.

  12. The ferric aerobactin receptor IutA, a protein isolated on agarose column, is not essential for uropathogenic Escherichia coli infection El receptor de aerobactina IutA, una proteína aislada en columna de agarosa, no es esencial para la infección por Escherichia coli uropatógena O receptor de aerobactina IutA, uma proteína isolada em coluna de agarose, não é essencial para a infecção por Escherichia coli uropatogênica

    Directory of Open Access Journals (Sweden)

    Taise Natali Landgraf

    2012-04-01

    Full Text Available Although many proteins have been described involved in Escherichia coli colonization and infection, only few reports have shown lectins as important components in these processes. Because the mechanisms underlying E. coli colonization process involving lectins are not fully understood, we sought to identify the presence of other non-described lectins in E. coli. Here, we isolated a 75-kDa protein from E. coli on Sepharose column and identified it as ferric aerobactin receptor (IutA. Since IutA is controversially associated with virulence of some E. coli strains, mainly in uropathogenic E. coli (UPEC, we evaluated the presence of iutA gene in UPEC isolated from patients with urinary infection. This gene was present in only 38% of the isolates, suggesting a weak association with virulence. Because there is a redundancy in the siderophore-mediated uptake systems, we suggest that IutA can be advantageous but not essential for UPEC.La falta de una clara comprensión de los mecanismos de participación de las lectinas en el proceso de colonización por Escherichia coli, nos motivó a identificar la presencia de otras lectinas que no han sido descritas en E. coli. En este estudio, se aisló una proteína de 75kDa de E. coli en una columna de Sepharosa, correspondiente al receptor de aerobactina (IutA. La asociación de IutA con cepas virulentas de E coli es controvertido, especialmente en E. coli uropatógena (UPEC, lo que nos llevó a evaluar la presencia del gen iutA en UPECs aisladas de pacientes con infección urinaria. El gen estaba presente en 38% de los aislamientos, lo que sugiere una débil asociación con la virulencia. Debido a la existencia de redundancia en los sistemas de captura de hierro, se sugiere que IutA puede ser una ventaja, sin embargo no es esencial para la UPEC.Apenas alguns relatos na literatura demonstram que lectinas são importantes nos processos de colonização e infecção por Escherichia coli. A falta de compreens

  13. EPR study of the low-spin state of Ru{sup 3+}in the YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4} aluminum borates

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, A.A., E-mail: andaprokhorov@gmail.com [Institute of Physics AS CR, Na Slovance 2, Praha 8 18221 (Czech Republic); Chernush, L.F. [A.A. Galkin Donetsk Physico-Technical Institute, 72, R. Luxembourg Str., Donetsk 83114 (Ukraine); Dyakonov, V.P.; Szymczak, H. [Institute of Physics, PAS, al. Lotników 32/46, Warsaw 02-668 (Poland); Prokhorov, A.D. [A.A. Galkin Donetsk Physico-Technical Institute, 72, R. Luxembourg Str., Donetsk 83114 (Ukraine)

    2016-12-15

    New data on the ground state of impurity Ru{sup 3+} ions in the crystals of YAl{sub 3}(BO{sub 3}){sub 4} and EuAl{sub 3}(BO{sub 3}){sub 4} aluminum borates were obtained. It was shown that Ru{sup 3+} ion replaces trivalent rare-earth ions without breaking the symmetry of the site. The crystal field acting on 4d{sup 5} ions forms an EPR spectrum, which is described by the spin Hamiltonian with S=1/2. The spin-Hamiltonian parameters determined are equal to g{sub II}=1.963, g{sub ⊥}=3.796, A{sub II}=43.03*10{sup −4} cm{sup −1}, A{sub ⊥}=84.86*10{sup −4} cm{sup −1} in the YAl{sub 3}(BO{sub 3}){sub 4} crystal (at T=15 K) and g{sub II}=2.016, g{sub ⊥}=3.796 in the EuAl{sub 3}(BO{sub 3}){sub 4} crystal (at T=15 K). It is found that the value of ∆g=g{sub II}-g{sub ⊥} is an indicator of distortions of nearest environment of Ru{sup 3+} ion. The angle between the C{sub 3} axis and the direction into nearest oxygen ion was determined. The EPR linewidth of Ru{sup 3+} ion increases with increasing temperature due to the dipole-dipole and exchange interactions with the excited states of the host lattice Ru{sup 3+} ion.

  14. The structural chemistry of metallocorroles: combined X-ray crystallography and quantum chemistry studies afford unique insights.

    Science.gov (United States)

    Thomas, Kolle E; Alemayehu, Abraham B; Conradie, Jeanet; Beavers, Christine M; Ghosh, Abhik

    2012-08-21

    Although they share some superficial structural similarities with porphyrins, corroles, trianionic ligands with contracted cores, give rise to fundamentally different transition metal complexes in comparison with the dianionic porphyrins. Many metallocorroles are formally high-valent, although a good fraction of them are also noninnocent, with significant corrole radical character. These electronic-structural characteristics result in a variety of fascinating spectroscopic behavior, including highly characteristic, paramagnetically shifted NMR spectra and textbook cases of charge-transfer spectra. Although our early research on corroles focused on spectroscopy, we soon learned that the geometric structures of metallocorroles provide a fascinating window into their electronic-structural characteristics. Thus, we used X-ray structure determinations and quantum chemical studies, chiefly using DFT, to obtain a comprehensive understanding of metallocorrole geometric and electronic structures. This Account describes our studies of the structural chemistry of metallocorroles. At first blush, the planar or mildly domed structure of metallocorroles might appear somewhat uninteresting particularly when compared to metalloporphyrins. Metalloporphyrins, especially sterically hindered ones, are routinely ruffled or saddled, but the missing meso carbon apparently makes the corrole skeleton much more resistant to nonplanar distortions. Ruffling, where the pyrrole rings are alternately twisted about the M-N bonds, is energetically impossible for metallocorroles. Saddling is also uncommon; thus, a number of sterically hindered, fully substituted metallocorroles exhibit almost perfectly planar macrocycle cores. Against this backdrop, copper corroles stand out as an important exception. As a result of an energetically favorable Cu(d(x2-y2))-corrole(π) orbital interaction, copper corroles, even sterically unhindered ones, are inherently saddled. Sterically hindered substituents

  15. Heme environment in HmuY, the heme-binding protein of Porphyromonas gingivalis

    International Nuclear Information System (INIS)

    Wojtowicz, Halina; Wojaczynski, Jacek; Olczak, Mariusz; Kroliczewski, Jaroslaw; Latos-Grazynski, Lechoslaw; Olczak, Teresa

    2009-01-01

    Porphyromonas gingivalis, a Gram-negative anaerobic bacterium implicated in the development and progression of chronic periodontitis, acquires heme for growth by a novel mechanism composed of HmuY and HmuR proteins. The aim of this study was to characterize the nature of heme binding to HmuY. The protein was expressed, purified and detailed investigations using UV-vis absorption, CD, MCD, and 1 H NMR spectroscopy were carried out. Ferric heme bound to HmuY may be reduced by sodium dithionite and re-oxidized by potassium ferricyanide. Heme complexed to HmuY, with a midpoint potential of 136 mV, is in a low-spin Fe(III) hexa-coordinate environment. Analysis of heme binding to several single and double HmuY mutants with the methionine, histidine, cysteine, or tyrosine residues replaced by an alanine residue identified histidines 134 and 166 as potential heme ligands.

  16. Heme environment in HmuY, the heme-binding protein of Porphyromonas gingivalis

    Energy Technology Data Exchange (ETDEWEB)

    Wojtowicz, Halina [Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw (Poland); Wojaczynski, Jacek [Department of Chemistry, University of Wroclaw, 50-383 Wroclaw (Poland); Olczak, Mariusz [Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw (Poland); Kroliczewski, Jaroslaw [Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, 50-148 Wroclaw (Poland); Latos-Grazynski, Lechoslaw [Department of Chemistry, University of Wroclaw, 50-383 Wroclaw (Poland); Olczak, Teresa [Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw (Poland)

    2009-05-29

    Porphyromonas gingivalis, a Gram-negative anaerobic bacterium implicated in the development and progression of chronic periodontitis, acquires heme for growth by a novel mechanism composed of HmuY and HmuR proteins. The aim of this study was to characterize the nature of heme binding to HmuY. The protein was expressed, purified and detailed investigations using UV-vis absorption, CD, MCD, and {sup 1}H NMR spectroscopy were carried out. Ferric heme bound to HmuY may be reduced by sodium dithionite and re-oxidized by potassium ferricyanide. Heme complexed to HmuY, with a midpoint potential of 136 mV, is in a low-spin Fe(III) hexa-coordinate environment. Analysis of heme binding to several single and double HmuY mutants with the methionine, histidine, cysteine, or tyrosine residues replaced by an alanine residue identified histidines 134 and 166 as potential heme ligands.

  17. Resonance Raman studies of Escherichia coli cytochrome bd oxidase. Selective enhancement of the three heme chromophores of the "as-isolated" enzyme and characterization of the cyanide adduct.

    Science.gov (United States)

    Sun, J; Osborne, J P; Kahlow, M A; Kaysser, T M; Hil, J J; Gennis, R B; Loehr, T M

    1995-09-26

    Cytochrome bd oxidase is a terminal bacterial oxidase containing three cofactors: a low-spin heme (b558), a high-spin heme (b595), and a chlorin d. The center of dioxygen reduction has been proposed to be at a dinuclear b595/d site, whereas b558 is mainly involved in transferring electrons from ubiquinone. One of the unique functional features of this enzyme is its resistance to high concentrations of cyanide (Ki in the millimolar range). With the appropriate selection of laser lines, the ligation and spin states of the b558, b595, and d hemes can be probed selectively by resonance Raman (rR) spectroscopy. Wavelengths between 400 and 500 nm predominantly excite the rR spectra of the b558 and b595 chromophores. Spectra obtained within this interval show a mixed population of spin and ligation states arising from b558 and b595, with the former more strongly enhanced at higher energy. Red excitation wavelengths (590-650 nm) generate rR spectra characteristic of chlorins, indicating the selective enhancement of the d heme. These rR results reveal that cytochrome bd oxidase "as isolated" contains the b558 heme in a six-coordinate low-spin ferric state, the b595 heme in a five-coordinate high-spin (5cHS) ferric state, and the d heme in a mixture of oxygenated (FeIIO2 FeIIIO2-; d650) and ferryl-oxo (FeIV = O; d680) states. However, the rR spectra of these two chlorin species indicate that they are both in the 5cHS state, suggesting that the d heme is lacking a strongly coordinated sixth ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Resonance Raman detection of iron-ligand vibrations in cyano(pyridine)(octaethylporphinato)iron(III): Effects of pyridine basicity on the Fe-CN bond strength

    International Nuclear Information System (INIS)

    Uno, Tadayuki; Hatano, Keiichiro; Nishimura, Yoshifumi; Arata, Yoji

    1988-01-01

    The influence of axial ligand basicity on the bonding of iron(III) in cyano adducts of octaethylporphyrin has been studied by resonance Raman spectroscopy. In a six-coordinate ferric low-spin complex, cyano(pyridine)(octaethylporphinato)iron(III), Fe(OEP)(CN)(py), Raman lines at 449 and 191 cm -1 were assigned to the ν(Fe-CN) and ν(Fe-py) stretching modes, respectively. When pyridine was displaced with its derivatives, py-X, where X = 4-cyano, 3-acetyl, 3-methyl, 4-methyl, 3,4-dimethyl, and 4-dimethylamino, the ν(Fe-CN) stretching frequency was found to decrease in the complex with a high pyridine basicity. It was concluded that the stronger the trans pyridine basicity, the weaker the iron-carbon (cyanide) bond. A clear frequency shift was observed in the ν 4 model, though most of the porphyrin vibrations were insensitive to the ligand substitution. The frequency of the ν 4 mode, which is the C a -N(pyrrole) breathing vibration of the porphyrin skeleton, was found to increase with an increase in pyridine basicity. This is contrary to what was found in ferrous low-spin hemes as CO complexes. The ν 4 shift in the CN complexes was explained in terms of forward π donation; donation of electrons from the porphyrin π orbital to the d π vacancy of the low-spin iron(III) weakened the C a -N(pyrrole) bonds and hence decreased the ν 4 frequency. 32 references, 8 figures

  19. FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids.

    Science.gov (United States)

    Banerjee, Sambuddha; Paul, Subrata; Nguyen, Leonard T; Chu, Byron C H; Vogel, Hans J

    2016-01-01

    The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.

  20. Zn and Fe complexes containing a redox active macrocyclic biquinazoline ligand.

    Science.gov (United States)

    Banerjee, Priyabrata; Company, Anna; Weyhermüller, Thomas; Bill, Eckhard; Hess, Corinna R

    2009-04-06

    A series of iron and zinc complexes has been synthesized, coordinated by the macrocyclic biquinazoline ligand, 2-4:6-8-bis(3,3,4,4-tetramethyldihydropyrrolo)-10-15-(2,2'-biquinazolino)-[15]-1,3,5,8,10,14-hexaene-1,3,7,9,11,14-N(6) (Mabiq). The Mabiq ligand consists of a bipyrimidine moiety and two dihydropyrrole units. The electronic structures of the metal-Mabiq complexes have been characterized using spectroscopic and density-functional theory (DFT) computational methods. The parent zinc complex exhibits a ligand-centered reduction to generate the metal-coordinated Mabiq radical dianion, establishing the redox non-innocence of this ligand. Iron-Mabiq complexes have been isolated in three oxidation states. This redox series includes low-spin ferric and low-spin ferrous species, as well as an intermediate-spin Fe(II) compound. In the latter complex, the iron ion is antiferromagnetically coupled to a Mabiq-centered pi-radical. The results demonstrate the rich redox chemistry and electronic properties of metal complexes coordinated by the Mabiq ligand.

  1. Stoichiometry-based estimates of ferric iron in calcic, sodic-calcic and sodic amphiboles: a comparison of various methods

    Directory of Open Access Journals (Sweden)

    Gualda Guilherme A.R.

    2005-01-01

    Full Text Available An important drawback of the electron microprobe is its inability to quantify Fe3+/Fe2+ ratios in routine work. Although these ratios can be calculated, there is no unique criterion that can be applied to all amphiboles. Using a large data set of calcic, sodic-calcic, and sodic amphibole analysis from A-type granites and syenites from southern Brazil, weassess the choices made by the method of Schumacher (1997, Canadian Mineralogist, 35: 238-246, which uses the average between selected maximum and minimum estimates. Maximum estimates selected most frequently are: 13 cations excluding Ca, Na, and K (13eCNK - 66%; sum of Si and Al equal to 8 (8SiAl - 17%; 15 cations excluding K (15eK - 8%. These selections are appropriate based on crystallochemical considerations. Minimum estimates are mostly all iron as Fe2+ (all Fe2 - 71%, and are clearly inadequate. Hence, maximum estimates should better approximate the actual values. To test this, complete analyses were selected from the literature, and calculated and measured values were compared. 13eCNK and maximum estimates are precise and accurate (concordance correlation coefficient- r c " 0.85. As expected, averages yield poor estimates (r c = 0.56. We recommend, thus, that maximum estimates be used for calcic, sodic-calcic, and sodic amphiboles.

  2. Coagulation performance of a novel poly-ferric-acetate (PFC) coagulant in phosphate-kaolin synthetic water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yanxin; Lu, Jinpeng; Dong, Xiongzi; Yao, Chengli [Hefei Normal University, Hefei (China); Hao, Jianwen [Anhui Vocational and Technical College, Hefei (China)

    2017-10-15

    The process of coagulation-flocculation is increasingly applied in wastewater treatment. And the polymerized inorganic coagulants are widely used among these coagulation-flocculation processes. However, conventional coagulants using sulfates or chlorides as counter anion may give rise to corrosion. The purpose of this study was to synthesize PFC coagulants in which acetate is used as counter anion. The influences on the preparation of PFC were optimized. The synthesis was done at the optimum conditions, such as temperature of 60 .deg. C, the Fe/CH{sub 3}COOH molar ratio of 1 : 4.0 and reaction time of 6 h, respectively. The prepared PFC coagulants were characterized by Fourier transform infrared (FTIR) spectrophotometry and scanning electron microscopy (SEM). PFC was found to mainly form complexation polymeric species and present more cluster and lamellar structure. A series of jar tests were carried out to study the coagulation performance of PFC and PFS in phosphate-kaolin synthetic water treatment. Results showed that the coagulation performance of PFC was more efficient than PFS's in terms of the phosphorus removal efficiency and the residual turbidity. Due to using acetate as counter anion to iron, PFC is less harmful to the processes of water treatment and equipment than that of the conventional coagulants applied chlorides or sulfates. Therefore, PFC is a promising coagulant in the process of corrosion sensitive applications and the process of wastewater containing phosphorus treatment.

  3. Kinetics of Np(4) oxidation reaction by persulphate in nitric acid solution in the presence of ferric ions as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Koltunov, V S; Marchenko, V I

    1976-01-01

    The kinetics of the reaction Np(IV) + Fe(III) = Np(V) + Fe(II)was investigated by a spectrophotometric method according to observation of the consumption of Np(IV) at 720 nm in a solution of HNO/sub 3/ + NaNO/sub 3/ in the concentration range; (F(III))equal (5.12-102.4).10/sup -3/ M, (H+) equal 0.14-1 M, (NO/sub 3//sup -/) = 0.5-2 M at an ionic strength of the solution ..mu.. = 0.2-2 and temperatures of 25-46/sup 0/C. To exclude the reverse reaction, (3-6).10/sup -2/ M (NH/sub 4/)/sub 2/S/sub 2/O/sub 8/, which rapidly oxidizes Fe(II), was added to the solution. The possible oxidation of Np(V) to Np(VI) was prevented by the addition of small quantities of N/sub 2/H/sub 4/. It was shown that the reaction rate is described by the equation -d(Np(IV))/dt=k(Np(IV))(Fe(III))/(H/sup +/)/sup 3/. where k = 0.490 +- 0.026 M/sup 2/.min/sup -1/ at 25/sup 0/ and ..mu.. = 1. The No/sub 3//sup -/ ions inhibit the reaction in the interval (NO/sub 3//sup -/) = 0-1 M and do not influence it at (NO/sub 3//sup -/) > 1 M. On the basis of an investigation of the dependence of k on the temperature, the energy (E = 32.5 kcal/mole), free energy (..delta..F* = 20.3 kcal/mole), and entropy (..delta..S* = 39 entropy units) of activation of the reaction were calculated. The reaction mechanism is discussed.

  4. Neurotoxicity of low-dose repeatedly intranasal instillation of nano- and submicron-sized ferric oxide particles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Feng Weiyue, E-mail: fengwy@mail.ihep.ac.cn; Zhu Motao; Wang Yun; Wang Meng [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Gu Yiqun [Maternity Hospital of Haidian District (China); Ouyang Hong; Wang Huajian; Li Ming; Zhao Yuliang, E-mail: zhaoyuliang@mail.ihep.ac.cn; Chai Zhifang [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Wang Haifang [Peking University, College of Chemistry and Molecular Engineering (China)

    2009-01-15

    Olfactory tract has been demonstrated to be an important portal for inhaled solid nanoparticle transportation into the central nervous system (CNS). We have previously demonstrated that intranasally instilled Fe{sub 2}O{sub 3} nanoparticles could transport into the CNS via olfactory pathway. In this study, we investigated the neurotoxicity and size effect of repeatedly low-dose (130 {mu}g) intranasal exposure of nano- and submicron-sized Fe{sub 2}O{sub 3} particles (21 nm and 280 nm) to mice. The biomarkers of oxidative stress, activity of nitric oxide synthases and release of monoamine neurotransmitter in the brain were studied. Our results showed that significant oxidative stress was induced by the two sizes of Fe{sub 2}O{sub 3} particles. The activities of GSH-Px, Cu,Zn-SOD, and cNOS significantly elevated and the total GSH and GSH/GSSG ratio significantly decreased in the olfactory bulb and hippocampus after the nano- and submicron-sized Fe{sub 2}O{sub 3} particle treatment (p < 0.05). The nano-sized Fe{sub 2}O{sub 3} generally induced greater alteration and more significant dose-effect response than the submicron-sized particle did. Some slight perturbation of monoamine neurotransmitters were found in the hippocampus after exposure to the two sizes of Fe{sub 2}O{sub 3} particle. The TEM image showed that some ultrastructural alterations in nerve cells, including neurodendron degeneration, membranous structure disruption and lysosome increase in the olfactory bulb, slight dilation in the rough endoplasmic reticulum and lysosome increase in the hippocampus were induced by the nano-sized Fe{sub 2}O{sub 3} treatment. In contrast, in the submicron-sized Fe{sub 2}O{sub 3} treated mice, slightly swollen mitochondria and some vacuoles were observed in the olfactory bulb and hippocampus, respectively. These results indicate that intranasal exposure of Fe{sub 2}O{sub 3} nanoparticles could induce more severe oxidative stress and nerve cell damage in the brain than the larger particle did. This is the first study to compare the neurotoxicity of nano- and submicron-sized Fe{sub 2}O{sub 3} particles in the central nervous system after long-term and low-dose intranasal exposure.

  5. Determination of diffuse double layer protonation constants for hydrous ferric oxide (HFO): supporting evidence for the Dzombak and Morel compilation

    CSIR Research Space (South Africa)

    Pretorius, PJ

    1998-01-01

    Full Text Available of the experimental system suggests that titration points below pH 4 should not be used for the determination of protonation constants because of potential HFO dissolution. Surface protonation constant, PZC and binding site estimates agree excellently with currently...

  6. Analysis of low concentration of free ferric oxides in clays by vis diffuse reflectance spectroscopy and voltammetry

    Czech Academy of Sciences Publication Activity Database

    Grygar, Tomáš; Dědeček, Jiří; Hradil, David

    2002-01-01

    Roč. 53, č. 2 (2002), s. 71-77 ISSN 0016-7738 R&D Projects: GA ČR GA205/00/1349 Institutional research plan: CEZ:AV0Z4032918 Keywords : voltammetry * Vis spectroscopy * analysis Subject RIV: CA - Inorganic Chemistry

  7. Effect of dissolved ozone or ferric ions on photodegradation of thiacloprid in presence of different TiO2 catalysts

    International Nuclear Information System (INIS)

    Cernigoj, Urh; Stangar, Urska Lavrencic; Jirkovsky, Jaromir

    2010-01-01

    Combining TiO 2 photocatalysis with inorganic oxidants (such as O 3 and H 2 O 2 ) or transition metal ions (Fe 3+ , Cu 2+ and Ag + ) often leads to a synergic effect. Electron transfer between TiO 2 and the oxidant is usually involved. Accordingly, the degree of synergy could be influenced by TiO 2 surface area. With this in mind, the disappearance of thiacloprid, a neonicotinoid insecticide, was studied applying various photochemical AOPs and different TiO 2 photocatalysts. In photocatalytic ozonation experiments, synergic effect of three different TiO 2 photocatalysts was quantified. Higher surface area resulted in a more pronounced synergic effect but an increasing amount of TiO 2 did not influence the degree of the synergy. This supports the theory that the synergy is a consequence of adsorption of ozone on the TiO 2 surface. No synergy was observed in photocatalytic degradation of thiacloprid in the presence of dissolved iron(III) species performed under varied experimental conditions (concentration, age of iron(III) solution, different TiO 2 films, usage of TiO 2 slurries). This goes against the literature for different organic compounds (i.e., monuron). It indicates different roles of iron(III) in the photodegradation of different organic molecules. Moreover, TiO 2 surface area did not affect photodegradation efficiency in iron(III)-based experiments which could confirm absence of electron transfer between TiO 2 photocatalyst and iron(III).

  8. Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

    Science.gov (United States)

    Gu, Baohua; Cole, David R.; Brown, Gilbert M.

    2004-10-05

    A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

  9. Isolation and identification of ferric reducing bacteria and evaluation of their roles in iron availability in two calcareous soils

    Science.gov (United States)

    Ghorbanzadeh, N.; Lakzian, A.; Haghnia, G. H.; Karimi, A. R.

    2014-12-01

    Iron is an essential element for all organisms which plays a crucial role in important biochemical processes such as respiration and photosynthesis. Iron deficiency seems to be an important problem in many calcareous soils. Biological dissimilatory Fe(III) reduction increases iron availability through reduction of Fe(III) to Fe(II). The aim of this study was to isolate, identify and evaluate some bacterial isolates for their abilities to reduce Fe(III) in two calcareous soils. Three bacterial isolates were selected and identified from paddy soils by using 16S rRNA amplification and then inoculated to sterilized and non-sterilized calcareous soils in the presence and absence of glucose. The results showed that all isolates belonged to Bacillus genus and were capable of reducing Fe(III) to Fe(II) in vitro condition. The amount of Fe(III) reduction in sterilized calcareous soils was significantly higher when inoculated with PS23 isolate and Shewanella putrefaciens ( S. putrefaciens) (as positive control) compared to PS16 and PS11 isolates. No significant difference was observed between PS11 and PS16 isolates in the presence of indigenous microbial community. The results also revealed that glucose had a significant effect on Fe(III) reduction in the examined calcareous soil samples. The amount of Fe(III) reduction increased two-fold when soil samples were treated with glucose and inoculated by S. putrefaciens and PS23 in non-sterilized soils.

  10. Sealing of adhesive systems in ferric sulfate-contaminated dentinal margins in class V composite resin restorations

    Directory of Open Access Journals (Sweden)

    Niloofar Shadman

    2016-03-01

    Full Text Available Background. Hemostatic agents are applied to prepare an isolated bleeding-free condition during dental treatments and can influence adhesive restorations. This study evaluated the effect of a hemostatic agent (ViscoStat on microleakage of contaminated dentinal margin of class V composite resin restorations with three adhesives. Methods. Sixty freshly extracted human molars were selected and class V cavities (3×3×1.5 mm were prepared on buccal and lingual surfaces. Gingival margins of the cavities were placed below the cementoenamel junction. The teeth were divided into six groups randomly. The adhesives were Excite, AdheSE and AdheSE One. In three groups, the gingival walls of the cavities were contaminated with ViscoStat and then rinsed. The cavities were restored with composite resin and light-cured. After storage in distilled water (37°C for 24 hours and polishing, the samples were thermocycled and sealed with nail varnish. Then they were stored in 1% basic fuchsin for 24 hours, rinsed and mounted in self-cured acryl resin, followed by sectioning buccolingually. Dye penetration was observed under a stereomicroscope and scored. Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests. P 0.05. In the contaminated groups, Excite had significantly less microleakage than the others (P = 0.003. AdheSE and AdheSE One did not exhibit significant difference in microleakage (P > 0.05. Conclusion. ViscoStat hemostatic agent increased dentinal microleakage in AdheSE and AdheSE One adhesives with no effect on Excite.

  11. Ferric Complexes of 3-Hydroxy-4-pyridinones Characterized by Density Functional Theory and Raman and UV−vis Spectroscopies

    Czech Academy of Sciences Publication Activity Database

    Šebestík, Jaroslav; Šafařík, Martin; Bouř, Petr

    2012-01-01

    Roč. 51, č. 8 (2012), s. 4473-4481 ISSN 0020-1669 R&D Projects: GA ČR GA203/07/1517; GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:AV ČR(CZ) M200550902 Institutional research plan: CEZ:AV0Z40550506 Keywords : Raman spectroscopy * UV-Vis spectroscopy * DFT * CAM-B3LYP * deferipron Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.593, year: 2012

  12. Enhanced cellulase hydrolysis of eucalyptus waste fibers from pulp mill by Tween80-assisted ferric chloride pretreatment.

    Science.gov (United States)

    Chen, Liheng; Fu, Shiyu

    2013-04-03

    Pretreatment combining FeCl3 and Tween80 was performed for cellulose-to-ethanol conversion of eucalyptus alkaline peroxide mechanical pulping waste fibers (EAWFs). The FeCl3 pretreatment alone showed a good effect on the enzymatic hydrolysis of EAWFs, but inhibited enzyme activity to some extent. A surfactant, Tween80, added during FeCl3 pretreatment was shown to significantly enhance enzyme reaction by eluting enzymatic inhibitors such as iron(III) that are present at the surface of the pretreated biomass. Treatment temperature, liquid-solid ratio, treatment time, FeCl3 concentration, and Tween80 dosage for pretreatment were optimized as follows: 180 °C, 8:1, 30 min, 0.15 mol/L, and 1% (w/v). Pretreated EAWFs under such optimal conditions provided enzymatic glucose (based on 100 g of oven-dried feedstock) and substrate enzymatic digestibility of EAWFs of 34.8 g and 91.3% after 72 h of enzymatic hydrolysis, respectively, with an initial cellulase loading of 20 FPU/g substrate.

  13. Effect of dissolved ozone or ferric ions on photodegradation of thiacloprid in presence of different TiO2 catalysts

    Czech Academy of Sciences Publication Activity Database

    Černigoj, U.; Štangar, U. L.; Jirkovský, Jaromír

    2010-01-01

    Roč. 177, 1-3 (2010), s. 399-406 ISSN 0304-3894 Institutional research plan: CEZ:AV0Z40400503 Keywords : neonicotionoid pesticides * photocatalysis * ozonation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.723, year: 2010

  14. Flavins secreted by roots of iron-deficient Beta vulgaris enable mining of ferric oxide via reductive mechanisms.

    Science.gov (United States)

    Sisó-Terraza, Patricia; Rios, Juan J; Abadía, Javier; Abadía, Anunciación; Álvarez-Fernández, Ana

    2016-01-01

    Iron (Fe) is abundant in soils but generally poorly soluble. Plants, with the exception of Graminaceae, take up Fe using an Fe(III)-chelate reductase coupled to an Fe(II) transporter. Whether or not nongraminaceous species can convert scarcely soluble Fe(III) forms into soluble Fe forms has deserved little attention so far. We have used Beta vulgaris, one among the many species whose roots secrete flavins upon Fe deficiency, to study whether or not flavins are involved in Fe acquisition. Flavins secreted by Fe-deficient plants were removed from the nutrient solution, and plants were compared with Fe-sufficient plants and Fe-deficient plants without flavin removal. Solubilization of a scarcely soluble Fe(III)-oxide was assessed in the presence or absence of flavins, NADH (nicotinamide adenine dinucleotide, reduced form) or plant roots, and an Fe(II) trapping agent. The removal of flavins from the nutrient solution aggravated the Fe deficiency-induced leaf chlorosis. Flavins were able to dissolve an Fe(III)-oxide in the presence of NADH. The addition of extracellular flavins enabled roots of Fe-deficient plants to reductively dissolve an Fe(III)-oxide. We concluded that root-secretion of flavins improves Fe nutrition in B. vulgaris. Flavins allow B. vulgaris roots to mine Fe from Fe(III)-oxides via reductive mechanisms. © 2015 CSIC New Phytologist © 2015 New Phytologist Trust.

  15. Biological regeneration of ferric ("Fe3+") solution during desulphurisation of gaseous streams: effect of nutrients and support material

    CSIR Research Space (South Africa)

    Mulopo, J

    2015-03-01

    Full Text Available + are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous...

  16. Photocatalytic activity of ferric oxide/titanium dioxide nanocomposite films on stainless steel fabricated by anodization and ion implantation

    Science.gov (United States)

    Zhan, Wei-ting; Ni, Hong-wei; Chen, Rong-sheng; Yue, Gao; Tai, Jun-kai; Wang, Zi-yang

    2013-08-01

    A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 1015 atoms·cm-2 and then annealed in air at 450°C for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution (3.5 wt%) by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe2O3/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.

  17. Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

    Energy Technology Data Exchange (ETDEWEB)

    Erin K. Field; Robin Gerlach; Sridhar Viamajala; Laura K. Jennings; Alfred B. Cunningham; Brent M. Peyton; William A. Apel

    2011-09-01

    The reduction of hexavalent chromium, Cr(VI), to trivalent chromium, Cr(III), can be an important aspect of remediation processes at Department of Energy (DOE) and other contaminated sites. Cellulomonas species are found at several Cr(VI) contaminated and uncontaminated locations at the DOE site in Hanford, Washington. Members of this genus have demonstrated the ability to effectively reduce Cr(VI) to Cr(III) fermentatively and therefore play a potential role in hexavalent chromium remediation at this site. Batch studies were conducted with Cellulomonas sp. strain ES6 to assess the influence of various carbon sources, iron minerals, and electron shuttling compounds on Cr(VI) reduction. These chemical species are likely to be present in these terrestrial environments during in situ bioremediation. Results indicated that there were a number of interactions between these compounds that influenced Cr(VI) reduction rates. The type of carbon source as well as the type of electron shuttle present influenced Cr(VI) reduction rates. When an electron shuttle, such as anthraquinone-2,6-disulfonate (AQDS), was present in the system, reduction rates increased significantly. Biologically reduced AQDS (AHDS) reduced Cr(VI) almost instantaneously. The presence of iron minerals and their concentrations did not significantly influence Cr(VI) reduction rates. However, strain ES6 or AQDS could directly reduce surface-associated Fe(III) to Fe(II) which was capable of reducing Cr(VI) at a near instantaneous rate. These results suggest the rate limiting step in these systems is the transfer of electrons from strain ES6 to the intermediate or terminal electron acceptor whether that is Cr(VI), Fe(III), or AQDS.

  18. Uranium potentiometer determination in inactive atmosphere with ferric sulfate; Determinacion poteniometrica de uranio en atmosfera inerte con sulfato ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R; Alonso Lopez, J

    1956-07-01

    Potentiometric titration of Uranium with (SO{sub 4}){sub 3} Fe{sub 2}, using Cd as reducing agent has been studied; acidity and sensibility of this reaction are fixed. This method yields good results for uranite group, removing previously phosphate by ion exchange with Amberlite IR-120. (Author)

  19. Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

    Energy Technology Data Exchange (ETDEWEB)

    Halasyamani, Shiv [Univ. of Houston, TX (United States); Fennie, Craig [Cornell Univ., Ithaca, NY (United States)

    2016-11-03

    We have focused on the synthesis, characterization, and ab initio theory on multi-functional mixed-metal fluorides. With funding from the DOE, we have successfully synthesized and characterized a variety of mixed metal fluoride materials.

  20. Spectrophotometric Determination of Labetalol and Lercanidipine in Pure Form and in Pharmaceutical Preparations Using Ferric-1,10-Phenanthroline

    OpenAIRE

    Abu El-Enin, M. A.; El-Wasseef, D. R.; El-Sherbiny, D. T.; El-Ashry, S. M.

    2009-01-01

    A simple and sensitive spectrophotometric method was developed for the determination of labetalol HCl (LBT) and lercanidipine HCl (LER) in pure form and in dosage forms. The method was based upon oxidation of the LBT and LER with Fe+3 and the estimation of the produced Fe+2 with 1,10-phenanthroline. The absorbance of the tris(1,10-phenanthroline) Fe+2 complex was measured at 510 nm. Reaction conditions were optimized to obtain colored complex of higher sensitivity and longer stability. The ab...

  1. MTBE DEGRADATION USING FENTON'S REAGENT: THE EFFECT OF FERROUS AND FERRIC IRON MIXTURES ON THE EFFICIENCY OF THE OVERALL REACTION

    Science.gov (United States)

    The gasoline additive MTBE has been extensively used in the U.S. since the late 70's to increase the octane rating in reformulated gasoline, replacing toxic organo-lead compounds. However, its use was boosted during the late 80's, when the study of additional physico-chemical pro...

  2. The green hemoproteins of bovine erythrocytes. II. Spectral, ligand-binding, and electrochemical properties.

    Science.gov (United States)

    DeFilippi, L J; Hultquist, D E

    1978-05-10

    The two green hemoproteins isolated from bovine erythrocytes (form I and form II) have been characterized as to spectral, electrochemical, and chemical properties. The absorption spectra of the isolated hemoproteins are typical of high spin ferric states. Reduction of the hemoproteins yields high spin ferrohemoproteins. Complexation of the ferrohemoproteins with CO and the ferrihemoproteins with cyanide yields low spin complexes, demonstrating the presence of an exchangeable weak field ligand in both the ferrous and ferric states of the hemoproteins. The differences in position and intensity of the absorption peaks of the visible spectra allow the two forms to be distinguished from one another. The midpoint potential of forms I and II were found to be +0.075 and +0.019 V, respectively, at pH 6.4 and +0.038 and -0.005 V, respectively, at pH 7.0. This is consistent with the gaining of 1 proton/electron during the reduction. The Nernst plot reveals an unusual 0.5-electron transfer, whereas a quantitative titration demonstrates a 1-electron transfer. Form I binds cyanide more tightly than form II (KD of 84 and 252 micrometer, respectively). The observed spectral, electrochemical, and ligand-binding differences between forms I and II can be explained in terms of a greater electron-withdrawing ability of the side chains of the heme of form I relative to the heme of form II.

  3. Structural and Mechanistic Insights into Hemoglobin-catalyzed Hydrogen Sulfide Oxidation and the Fate of Polysulfide Products

    Energy Technology Data Exchange (ETDEWEB)

    Vitvitsky, Victor; Yadav, Pramod K.; An, Sojin; Seravalli, Javier; Cho, Uhn-Soo; Banerjee, Ruma (Michigan-Med); (UNL)

    2017-02-17

    Hydrogen sulfide is a cardioprotective signaling molecule but is toxic at elevated concentrations. Red blood cells can synthesize H2S but, lacking organelles, cannot dispose of H2S via the mitochondrial sulfide oxidation pathway. We have recently shown that at high sulfide concentrations, ferric hemoglobin oxidizes H2S to a mixture of thiosulfate and iron-bound polysulfides in which the latter species predominates. Here, we report the crystal structure of human hemoglobin containing low spin ferric sulfide, the first intermediate in heme-catalyzed sulfide oxidation. The structure provides molecular insights into why sulfide is susceptible to oxidation in human hemoglobin but is stabilized against it in HbI, a specialized sulfide-carrying hemoglobin from a mollusk adapted to life in a sulfide-rich environment. We have also captured a second sulfide bound at a postulated ligand entry/exit site in the α-subunit of hemoglobin, which, to the best of our knowledge, represents the first direct evidence for this site being used to access the heme iron. Hydrodisulfide, a postulated intermediate at the junction between thiosulfate and polysulfide formation, coordinates ferric hemoglobin and, in the presence of air, generated thiosulfate. At low sulfide/heme iron ratios, the product distribution between thiosulfate and iron-bound polysulfides was approximately equal. The iron-bound polysulfides were unstable at physiological glutathione concentrations and were reduced with concomitant formation of glutathione persulfide, glutathione disulfide, and H2S. Hence, although polysulfides are unlikely to be stable in the reducing intracellular milieu, glutathione persulfide could serve as a persulfide donor for protein persulfidation, a posttranslational modification by which H2S is postulated to signal.

  4. Inverted porphyrins and expanded porphyrins: An overview

    Indian Academy of Sciences (India)

    Unknown

    More recently, synthetic porphyrins and porphyrin-like macrocycles have ... one of the meso carbons resulting in the formation of corroles; – (d) Isomeric ... spectroscopic, chemical and physical properties, which can find applications in ..... diol 55 under TFA catalysis yielding 20–28% yield of expected rubyrins 85 and 86 as.

  5. Recent developments in out-of-plane metallocorrole chemistry across the periodic table.

    Science.gov (United States)

    Buckley, Heather L; Arnold, John

    2015-01-07

    This article presents a brief review of recent developments in metallocorrole chemistry, with a focus on species with significant displacement of the metal from the N4 plane of the corrole ring. Comparisons based on X-ray crystallographic data are made between a range of early and/or heavy transition metal, lanthanide, actinide, and main group metallocorrole species.

  6. Effect of soil washing with only chelators or combining with ferric chloride on soil heavy metal removal and phytoavailability: Field experiments.

    Science.gov (United States)

    Guo, Xiaofang; Wei, Zebin; Wu, Qitang; Li, Chunping; Qian, Tianwei; Zheng, Wei

    2016-03-01

    In a field experiment on multi-metal contaminated soil, we investigated the efficiency of Cd, Pb, Zn, and Cu removal by only mixture of chelators (MC) or combining with FeCl3. After washing treatment, a co-cropping system was performed for heavy metals to be extracted by Sedum alfredii and to produce safe food from Zea mays. We analyzed the concentration of heavy metals in groundwater to evaluate the leashing risk of soil washing with FeCl3 and MC. Results showed that addition of FeCl3 was favorable to the removal of heavy metals in the topsoil. Metal leaching occurred mainly in rain season during the first co-cropping. The removal rates of Cd, Zn, Pb, and Cu in topsoil were 28%, 53%, 41%, and 21% with washing by FeCl3+MC after first harvest. The application of FeCl3 reduced the yield of S. alfredii and increased the metals concentration of Z. mays in first harvest. However, after amending soil, the metals concentration of Z. mays in FeCl3+MC treatment were similar to that only washing by MC. The grains and shoots of Z. mays were safe for use in feed production. Soil washing did not worsen groundwater contamination during the study period. But the concentration of Cd in groundwater was higher than the limit value of Standard concentrations for Groundwater IV. This study suggests that soil washing using FeCl3 and MC for the remediation of multi-metal contaminated soil is potential feasibility. However, the subsequent measure to improve the washed soil environment for planting crop is considered. Copyright © 2016. Published by Elsevier Ltd.

  7. Synthesis of nitrogen-doped and amino acid-functionalized graphene quantum dots from glycine, and their application to the fluorometric determination of ferric ion

    International Nuclear Information System (INIS)

    Li, Linbo; Li, Lin; Wang, Chao; Liu, Kangyu; Zhu, Ruohua; Qiang, Hong; Lin, Yuqing

    2015-01-01

    We report on a single-step thermolysis strategy to prepare highly luminescent nitrogen-doped and amino acid-functionalized graphene quantum dots (NA-GQDs) by using glycine as both carbon and nitrogen source. The NA-GQDs display an excitation wavelength-dependent fluorescence with maximum excitation and emission wavelengths of 380 and 450 nm, respectively, and a quantum yield of ∼16 %. Fluorescence is quenched by Fe(III) and Hg(II), and the effect was used to develop a method for the determination of Fe(III). Quenching by Fe(III) is attributed to its higher thermodynamic affinity (compared to other transition-metal ions) for the ligands on the GQDs in which nitrogen atoms mainly act as the chelating atoms. A linear relationship was observed between fluorescence intensity and the concentration of Fe(III) over the 0.5 μM to 0.5 mM range. The detection limit is 0.1 μM. (author)

  8. Optimized Reaction Conditions for Removal of Cellular Organic Matter of Microcystis aeruginosa During the Destabilization and Aggregation Process Using Ferric Sulfate in Water Purification

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Martin; Polášek, Pavel; Pivokonská, Lenka; Tomášková, Hana

    2009-01-01

    Roč. 81, č. 5 (2009), s. 514-522 ISSN 1061-4303 R&D Projects: GA ČR GA103/07/0295 Institutional research plan: CEZ:AV0Z20600510 Keywords : Microcystis aeruginosa * cellular organic matter * destabilization * aggregation * optimized reaction conditions * water purification Subject RIV: BK - Fluid Dynamics Impact factor: 0.965, year: 2009

  9. Spectral variations in rocks and soils containing ferric iron hydroxide and(or) sulfate minerals as seen by AVIRIS and laboratory spectroscopy

    Science.gov (United States)

    Rockwell, Barnaby W.

    2004-01-01

    Analysis of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data covering the Big Rock Candy Mountain area of the Marysvale volcanic field, west-central Utah, identified abundant rocks and soils bearing jarosite, goethite, and chlorite associated with volcanic rocks altered to propylitic grade during the Miocene (2321 Ma). Propylitically-altered rocks rich in pyrite associated with the relict feeder zones of convecting, shallow hydrothermal systems are currently undergoing supergene oxidation to natrojarosite, kaolinite, and gypsum. Goethite coatings are forming at the expense of jarosite where most pyrite has been consumed through oxidation in alluvium derived from pyrite-bearing zones. Spectral variations in the goethite-bearing rocks that resemble variations found in reference library samples of goethites of varying grain size were observed in the AVIRIS data. Rocks outside of the feeder zones have relatively low pyrite content and are characterized by chlorite, epidote, and calcite, with local copper-bearing quartz-calcite veins. Iron-bearing minerals in these rocks are weathering directly to goethite. Laboratory spectral analyses were applied to samples of iron-bearing rock outcrops and alluvium collected from the area to determine the accuracy of the AVIRIS-based mineral identification. The accuracy of the iron mineral identification results obtained by analysis of the AVIRIS data was confirmed. In general, the AVIRIS analysis results were accurate in identifying medium-grained goethite, coarse-grained goethite, medium- to coarse-grained goethite with trace jarosite, and mixtures of goethite and jarosite. However, rock fragments from alluvial areas identified as thin coatings of goethite with the AVIRIS data were found to consist mainly of medium- to coarse-grained goethite based on spectral characteristics in the visible and near-infrared. To determine if goethite abundance contributed to the spectral variations observed in goethite-bearing rocks with AVIRIS data, a laboratory experiment was performed in which spectra were acquired of a goethite-bearing rock while progressively decreasing the areal abundance of the rock with respect to a background of white, fine-grained quartz sand. This experiment found that, with decreasing material abundance, the crystal field absorption feature of goethite near 1.0 micron decreases in depth and narrows more from the long wavelength side of the feature than from the short wavelength side, as is the case in goethite reference spectra as grain size decreases from coarse to fine. In the Marysvale study area, goethite-bearing alluvium downgradient from source outcrops tends to be identified as finer-grained or thin coatings of goethite due to the minerals presence in lesser abundance. The goethite-bearing alluvium is a closer match to reference spectra of thin coatings of goethite even though the actual grain size of the contained goethite fragments is medium to coarse grained, the same on average as that from the source outcrops. Coarser-grained goethite most likely will be correctly identified in areas of greater goethite abundance proximal to jarosite-bearing source rock where the surface is relatively free of goethite-free soil components and vegetation that corrupt the goethite spectral response. When analysis of imaging spectroscopy data is performed using reference spectra of iron minerals of varying grain sizes and mixed compositions, the results are useful not only for purposes of mineral identification, but also for distinguishing goethite-bearing outcrop from alluvial surfaces with similar mineralogy, providing valuable information for geologic, geomorphologic, mineral exploration, and environmental assessment studies.

  10. Effect of pH and Calcium on the Adsorptive Removal of Cadmium and Copper by Iron Oxide–Coated Sand and Granular Ferric Hydroxide

    KAUST Repository

    Uwamariya, V.; Petrusevski, B.; Lens, P. N. L.; Amy, Gary L.

    2015-01-01

    H (from 6 to 8) resulted in a higher overall removal efficiency of both Cu2+ and Cd2+, with precipitation as predominant removal mechanisms at higher pH values, especially for Cu2+. An increase in Ca2+ concentration increased the precipitation of Cu2+ [as

  11. Phosphomolybdic acid and ferric iron as efficient electron mediators for coupling biomass pretreatment to produce bioethanol and electricity generation from wheat straw

    Science.gov (United States)

    Yi Ding; Bo Du; Xuebing Zhao; J.Y. Zhu; Dehua Liu

    2017-01-01

    Phosphomolybdic acid (PMo12) was used as an electron mediator and proton carrier to mediate biomass pretreatment for ethanol production and electricity generation from wheat straw. In the pretreatment, lignin was oxidized anaerobically by PMo12 with solubilization of a fraction of hemicelluloses, and the PMo12...

  12. Biocarbon can reduce the CO{sub 2} discharges from the ferric alloy industry; Biokarbon kan redusere CO{sub 2}-utslippene i ferrolegeringsindustrien

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Oddvar

    1999-07-01

    The article discusses the use of biocarbon mainly peat, for reduction processes and thereby reduce CO{sub 2} discharge. The costs have however, to be reduced considerably. Research in the field is briefly described.

  13. Effect of ferric sulfate contamination on the bonding effectiveness of etch-and-rinse and self-etch adhesives to superficial dentin

    OpenAIRE

    Shahram Farzin Ebrahimi; Niloofar Shadman; Arezoo Abrishami

    2013-01-01

    Aim: This study investigated the effect of one hemostatic agent on the shear bond strength of self-etch and etch-and-rinse adhesive systems. Materials and Methods: Sixty extracted third molars were selected. After preparing a flat surface of superficial dentin, they were randomly divided into six groups. Adhesives were Tetric N-Bond, AdheSE, and AdheSE One F. Before applying adhesives, surfaces were contaminated with ViscoStat for 60 s in three groups and rinsed. Then composite were attached ...

  14. Turn-off fluorescence sensor for the detection of ferric ion in water using green synthesized N-doped carbon dots and its bio-imaging.

    Science.gov (United States)

    Edison, Thomas Nesakumar Jebakumar Immanuel; Atchudan, Raji; Shim, Jae-Jin; Kalimuthu, Senthilkumar; Ahn, Byeong-Cheol; Lee, Yong Rok

    2016-05-01

    This paper reports turn-off fluorescence sensor for Fe(3+) ion in water using fluorescent N-doped carbon dots as a probe. A simple and efficient hydrothermal carbonization of Prunus avium fruit extract for the synthesis of fluorescent nitrogen-doped carbon dots (N-CDs) is described. This green approach proceeds quickly and provides good quality N-CDs. The mean size of synthesized N-CDs was approximately 7nm calculated from the high-resolution transmission electron microscopic images. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy revealed the presence of -OH, -NH2, -COOH, and -CO functional groups over the surface of CDs. The N-CDs showed excellent fluorescent properties, and emitted blue fluorescence at 411nm upon excitation at 310nm. The calculated quantum yield of the synthesized N-CDs is 13% against quinine sulfate as a reference fluorophore. The synthesized N-CDs were used as a fluorescent probe towards the selective and sensitive detection of biologically important Fe(3+) ions in water by fluorescence spectroscopy and for bio-imaging of MDA-MB-231 cells. The limit of detection (LOD) and the Stern-Volmer quenching constant for the synthesized N-CDs were 0.96μM and 2.0958×10(3)M of Fe(3+) ions. The green synthesized N-CDs are efficiently used as a promising candidate for the detection of Fe(3+) ions and bio-imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Organic complexation and translocation of ferric iron in podzols of the Negro River watershed. Separation of secondary Fe species from Al species

    Science.gov (United States)

    Fritsch, E.; Allard, Th.; Benedetti, M. F.; Bardy, M.; do Nascimento, N. R.; Li, Y.; Calas, G.

    2009-04-01

    The development of podzols in lateritic landscapes of the upper Amazon basin contributes to the exportation of organic carbon and associated metals in the black waters of the Negro River watershed. We have investigated the distribution of Fe III in the clay-size fraction of eight organic-rich horizons of waterlogged plateau podzols, to unravel the weathering conditions and mechanisms that control its transfer to the rivers. The speciation and amount of Fe III stored in residual mineral phases of laterites, or bound to organic compounds of weakly and well-expressed podzols, were determined by electron paramagnetic resonance spectroscopy combined with chemical analyses. Reducing conditions restrict the production of organo-Fe complexes in the subsoil B-horizons of waterlogged podzols and most of the Fe 2+ released from the dissolution of Fe-oxides is exported to the rivers via the perched groundwater. However, significant amounts of diluted Fe III bound to organic ligands (Fe IIIOM) and nano Fe-oxides are produced at the margin of the depression in the topsoil A horizons of weakly expressed podzols due to shorter periods of anoxia. The downward translocation of organically bound metals from topsoil A to subsoil B-horizons of podzols occurs in shorter distances for Fe than it does for Al. This separation of secondary Fe species from Al species is attributed to the physical fractionation of their organic carriers in texture contrasted B-horizons of podzols, as well as to the effect of pH on metal speciation in soil solutions and metal binding onto soil organic ligands (mostly for Al). This leads us to consider the topsoil A horizons of weakly expressed podzols, as well as the subsoil Bh horizon of better-expressed ones, as the main sources for the transfer of Fe IIIOM to the rivers. The concentration of Fe IIIOM rises from soil sources to river colloids, suggesting drastic biogeochemical changes in more oxygenated black waters of the Negro River watershed. The contribution of soil organic matter to the transfer of Fe to rivers is likely at the origin of the peculiar Fe isotope pattern recently recognized in podzolic environments.

  16. Hydrous ferric oxide: evaluation of Cd-HFO surface complexation models combining Cd(K) EXAFS data, potentiometric titration results, and surface site structures identified from mineralogical knowledge.

    Science.gov (United States)

    Spadini, Lorenzo; Schindler, Paul W; Charlet, Laurent; Manceau, Alain; Vala Ragnarsdottir, K

    2003-10-01

    The surface properties of ferrihydrite were studied by combining wet chemical data, Cd(K) EXAFS data, and a surface structure and protonation model of the ferrihydrite surface. Acid-base titration experiments and Cd(II)-ferrihydrite sorption experiments were performed within 3titration data could be adequately modeled by triple bond Fe- OH(2)(+1/2)-H(+)triple bond Fe-OH(-1/2),logk((int))=-8.29, assuming the existence of a unique intrinsic microscopic constant, logk((int)), and consequently the existence of a single significant type of acid-base reactive functional groups. The surface structure model indicates that these groups are terminal water groups. The Cd(II) data were modeled assuming the existence of a single reactive site. The model fits the data set at low Cd(II) concentration and up to 50% surface coverage. At high coverage more Cd(II) ions than predicted are adsorbed, which is indicative of the existence of a second type of site of lower affinity. This agrees with the surface structure and protonation model developed, which indicates comparable concentrations of high- and low-affinity sites. The model further shows that for each class of low- and high-affinity sites there exists a variety of corresponding Cd surface complex structure, depending on the model crystal faces on which the complexes develop. Generally, high-affinity surface structures have surface coordinations of 3 and 4, as compared to 1 and 2 for low-affinity surface structures.

  17. Novel chemoselective hydrogenation of aromatic nitro compounds over ferric hydroxide supported nanocluster gold in the presence of CO and H2O.

    Science.gov (United States)

    Liu, Lequan; Qiao, Botao; Chen, Zhengjian; Zhang, Juan; Deng, Youquan

    2009-02-14

    Chemoselective hydrogenation of aromatic nitro compounds were first efficiently achieved over Au/Fe(OH)(x) at 100-120 degrees C for 1.5-6 h (depending on different substrates) in the presence of CO and H(2)O.

  18. Ferric Sulfate and Proline Enhance Heavy-Metal Tolerance of Halophilic/Halotolerant Soil Microorganisms and Their Bioremediation Potential for Spilled-Oil Under Multiple Stresses

    Science.gov (United States)

    Al-Mailem, Dina M.; Eliyas, Mohamed; Radwan, Samir S.

    2018-01-01

    The aim of this study was to explore the heavy-metal resistance and hydrocarbonoclastic potential of microorganisms in a hypersaline soil. For this, hydrocarbonoclastic microorganisms were counted on a mineral medium with oil vapor as a sole carbon source in the presence of increasing concentrations of ZnSO4, HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4. The colony-forming units counted decreased in number from about 150 g-1 on the heavy-metal-free medium to zero units on media with 40–100 mg l-1 of HgCl2, CdSO4, PbNO3, or Na2HAsO4. On media with CuSO4 or ZnSO4 on the other hand, numbers increased first reaching maxima on media with 50 mg l-1 CuSO4 and 90 mg l-1 ZnSO4. Higher concentrations reduced the numbers, which however, still remained considerable. Pure microbial isolates in cultures tolerated 200–1600 mg l-1 of HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4 in the absence of crude oil. In the presence of oil vapor, the isolates tolerated much lower concentrations of the heavy metals, only 10–80 mg l-1. The addition of 10 Fe2(SO4)3 and 200 mg l-1 proline (by up to two- to threefold) enhanced the tolerance of several isolates to heavy metals, and consequently their potential for oil biodegradation in their presence. The results are useful in designing bioremediation technologies for oil spilled in hypersaline areas. PMID:29563904

  19. The ferric yersiniabactin uptake receptor FyuA is required for efficient biofilm formation by urinary tract infectious Escherichia coli in human urine

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Ferrieres, Lionel; Klemm, Per

    2008-01-01

    Urinary tract infection (UTI) is the most common infection in patients with indwelling urinary catheters, and bacterial biofilm formation is a major problem in this type of infection. Escherichia coli is responsible for the large majority of UTIs. Free iron is strictly limited in the human urinary...... of the most upregulated genes in biofilm; it was upregulated 63-fold in the E coli UTI strain VR50. FyuA was found to be highly important for biofilm formation in iron-poor environments such as human urine. Mutants in fyuA show aberrant biofilm formation and the cells become filamentous; a VR50fyuA mutant...... of iron greatly influences UTI strains' ability to form biofilm....

  20. Analogies and surprising differences between recombinant nitric oxide synthase-like proteins from Staphylococcus aureus and Bacillus anthracis in their interactions with l-arginine analogs and iron ligands.

    Science.gov (United States)

    Salard, Isabelle; Mercey, Emilie; Rekka, Eleni; Boucher, Jean-Luc; Nioche, Pierre; Mikula, Ivan; Martasek, Pavel; Raman, C S; Mansuy, Daniel

    2006-12-01

    Genome sequencing has recently shown the presence of genes coding for NO-synthase (NOS)-like proteins in bacteria. The roles of these proteins remain unclear. The interactions of a series of l-arginine (l-arg) analogs and iron ligands with two recombinant NOS-like proteins from Staphylococcus aureus (saNOS) and Bacillus anthracis (baNOS) have been studied by UV-visible spectroscopy. SaNOS and baNOS in their ferric native state, as well as their complexes with l-arg analogs and with various ligands, exhibit spectral characteristics highly similar to the corresponding complexes of heme-thiolate proteins such as cytochromes P450 and NOSs. However, saNOS greatly differs from baNOS at the level of three main properties: (i) native saNOS mainly exists under an hexacoordinated low-spin ferric state whereas native baNOS is mainly high-spin, (ii) the addition of tetrahydrobiopterin (H4B) or H4B analogs leads to an increase of the affinity of l-arg for saNOS but not for baNOS, and (iii) saNOS Fe(II), contrary to baNOS, binds relatively bulky ligands such as nitrosoalkanes and tert-butylisocyanide. Thus, saNOS exhibits properties very similar to those of the oxygenase domain of inducible NOS (iNOS(oxy)) not containing H4B, as expected for a NOSoxy-like protein that does not contain H4B. By contrast, the properties of baNOS which look like those of H4B-containing iNOS(oxy) are unexpected for a NOS-like protein not containing H4B. The origin of these surprising properties of baNOS remains to be determined.

  1. Characterization of SiaA, a streptococcal heme-binding protein associated with a heme ABC transport system.

    Science.gov (United States)

    Sook, Brian R; Block, Darci R; Sumithran, Suganya; Montañez, Griselle E; Rodgers, Kenton R; Dawson, John H; Eichenbaum, Zehava; Dixon, Dabney W

    2008-02-26

    Many pathogenic bacteria require heme and obtain it from their environment. Heme transverses the cytoplasmic membrane via an ATP binding cassette (ABC) pathway. Although a number of heme ABC transport systems have been described in pathogenic bacteria, there is as yet little biophysical characterization of the proteins in these systems. The sia (hts) gene cluster encodes a heme ABC transporter in the Gram positive Streptococcus pyogenes. The lipoprotein-anchored heme binding protein (HBP) of this transporter is SiaA (HtsA). In the current study, resonance Raman (rR), magnetic circular dichroism (MCD), and nuclear magnetic resonance (NMR) spectroscopies were used to determine the coordination state and spin state of both the ferric and ferrous forms of this protein. Identifiers from these techniques suggest that the heme is six-coordinate and low-spin in both oxidation states of the protein, with methionine and histidine as axial ligands. SiaA has a pKa of 9.7 +/- 0.1, attributed to deprotonation of the axial histidine. Guanidinium titration studies show that the ferric state is less stable than the ferrous state, with DeltaG(H2O) values for the oxidized and reduced proteins of 7.3 +/- 0.8 and 16.0 +/- 3.6 kcal mol-1, respectively. The reductive and oxidative midpoint potentials determined via spectroelectrochemistry are 83 +/- 3 and 64 +/- 3 mV, respectively; the irreversibility of heme reduction suggests that redox cycling of the heme is coupled to a kinetically sluggish change in structure or conformation. The biophysical characterization described herein will significantly advance our understanding of structure-function relationships in HBP.

  2. Quaternary structure of methemoglobin

    International Nuclear Information System (INIS)

    Chevion, M.; Ilan, Y.A.; Samuni, A.; Navok, T.; Czapski, G.

    1979-01-01

    The pulse radiolysis of solutions of adult human methemoglobin was used to reduce a single heme iron within the protein tetramers. The valence hybrids thus formed were reacted with oxygen. Kinetics of the reactions were studied. The effects of pH and inositol hexaphosphate were examined. The kinetics of the ligation of oxygen to stripped valence hybrids showed a single phase behavior at the pH range 6.5 to 9. As the pH was lowered below 6.5, a second, slower phase became apparent. In the presence of inositol hexaphosphate, above pH 8, the kinetics of oxygen binding was of a single phase. As the pH was lowered, a transition to a second, slower phase was noticed. Below pH 7, the slower phase was the only detectable one. On this basis, it is concluded that human adult stripped methemoglobin resides in an R quarternary structure, while the presence of IHP stabilizes the T structure at pH below 7.5. This transition between the quaternary structures of methemoglobin cannot be accounted for by the switch between the high spin and the low spin states of the ferric iron. This switch of spin state takes place at pH>8.2

  3. Purification, Reconstitution, and Inhibition of Cytochrome P-450 Sterol Δ22-Desaturase from the Pathogenic Fungus Candida glabrata

    Science.gov (United States)

    Lamb, David C.; Maspahy, Segula; Kelly, Diane E.; Manning, Nigel J.; Geber, Antonia; Bennett, John E.; Kelly, Steven L.

    1999-01-01

    Sterol Δ22-desaturase has been purified from a strain of Candida glabrata with a disruption in the gene encoding sterol 14α-demethylase (cytochrome P-45051; CYP51). The purified cytochrome P-450 exhibited sterol Δ22-desaturase activity in a reconstituted system with NADPH–cytochrome P-450 reductase in dilaurylphosphatidylcholine, with the enzyme kinetic studies revealing a Km for ergosta-5,7-dienol of 12.5 μM and a Vmax of 0.59 nmol of this substrate metabolized/min/nmol of P-450. This enzyme is encoded by CYP61 (ERG5) in Saccharomyces cerevisiae, and homologues have been shown in the Candida albicans and Schizosaccharomyces pombe genome projects. Ketoconazole, itraconazole, and fluconazole formed low-spin complexes with the ferric cytochrome and exhibited type II spectra, which are indicative of an interaction between the azole moiety and the cytochrome heme. The azole antifungal compounds inhibited reconstituted sterol Δ22-desaturase activity by binding to the cytochrome with a one-to-one stoichiometry, with total inhibition of enzyme activity occurring when equimolar amounts of azole and cytochrome P-450 were added. These results reveal the potential for sterol Δ22-desaturase to be an antifungal target and to contribute to the binding of drugs within the fungal cell. PMID:10390230

  4. Combined crystallographic and spectroscopic analysis of Trematomus bernacchii hemoglobin highlights analogies and differences in the peculiar oxidation pathway of Antarctic fish hemoglobins.

    Science.gov (United States)

    Merlino, Antonello; Vitagliano, Luigi; Howes, Barry D; Verde, Cinzia; di Prisco, Guido; Smulevich, Giulietta; Sica, Filomena; Vergara, Alessandro

    2009-12-01

    Recent studies have demonstrated that hemoglobins isolated from Antarctic fish undergo peculiar oxidation processes. Here we show, by combining crystallographic and spectroscopic data, that the oxidation pathway of Trematomus bernacchii hemoglobin (HbTb) is distinct from that observed for the major component of Trematomus newnesi (Hb1Tn), despite the high sequence identity of the two proteins and structural similarity of their ferrous and fully oxidized states. Resonance Raman analysis of HbTb autoxidation upon air-exposure reveals the absence of the oxidized pentacoordinated state that was observed for Hb1Tn. The HbTb oxidation pathway is characterized by two ferric species: an aquo hexacoordinated high spin state and a bis-histidyl hexacoordinated low spin form, which appear in the early stages of the oxidation process. The high resolution structure of an intermediate along the oxidation pathway has been determined at 1.4 A resolution. The analysis of the electron density of the heme pocket shows, for both the alpha and the beta iron, the coexistence of multiple binding states. In this partially oxidized form, HbTb exhibits significant deviations from the canonical R state both at the local and global level. The analysis of these modifications highlights the structural correlation between key functional regions of the protein.

  5. Spectroscopic characterization of a truncated hemoglobin from the nitrogen-fixing bacterium Herbaspirillum seropedicae.

    Science.gov (United States)

    Razzera, Guilherme; Vernal, Javier; Baruh, Debora; Serpa, Viviane I; Tavares, Carolina; Lara, Flávio; Souza, Emanuel M; Pedrosa, Fábio O; Almeida, Fábio C L; Terenzi, Hernán; Valente, Ana Paula

    2008-09-01

    The Herbaspirillum seropedicae genome sequence encodes a truncated hemoglobin typical of group II (Hs-trHb1) members of this family. We show that His-tagged recombinant Hs-trHb1 is monomeric in solution, and its optical spectrum resembles those of previously reported globins. NMR analysis allowed us to assign heme substituents. All data suggest that Hs-trHb1 undergoes a transition from an aquomet form in the ferric state to a hexacoordinate low-spin form in the ferrous state. The close positions of Ser-E7, Lys-E10, Tyr-B10, and His-CD1 in the distal pocket place them as candidates for heme coordination and ligand regulation. Peroxide degradation kinetics suggests an easy access to the heme pocket, as the protein offered no protection against peroxide degradation when compared with free heme. The high solvent exposure of the heme may be due to the presence of a flexible loop in the access pocket, as suggested by a structural model obtained by using homologous globins as templates. The truncated hemoglobin described here has unique features among truncated hemoglobins and may function in the facilitation of O(2) transfer and scavenging, playing an important role in the nitrogen-fixation mechanism.

  6. Oxidation of tertiary amines by cytochrome p450-kinetic isotope effect as a spin-state reactivity probe.

    Science.gov (United States)

    Li, Chunsen; Wu, Wei; Cho, Kyung-Bin; Shaik, Sason

    2009-08-24

    Two types of tertiary amine oxidation processes, namely, N-dealkylation and N-oxygenation, by compound I (Cpd I) of cytochrome P450 are studied theoretically using hybrid DFT calculations. All the calculations show that both N-dealkylation and N-oxygenation of trimethylamine (TMA) proceed preferentially from the low-spin (LS) state of Cpd I. Indeed, the computed kinetic isotope effects (KIEs) for the rate-controlling hydrogen abstraction step of dealkylation show that only the KIE(LS) fits the experimental datum, whereas the corresponding value for the high-spin (HS) process is much higher. These results second those published before for N,N-dimethylaniline (DMA), and as such, they further confirm the conclusion drawn then that KIEs can be a sensitive probe of spin state reactivity. The ferric-carbinolamine of TMA decomposes most likely in a non-enzymatic reaction since the Fe-O bond dissociation energy (BDE) is negative. The computational results reveal that in the reverse reaction of N-oxygenation, the N-oxide of aromatic amine can serve as a better oxygen donor than that of aliphatic amine to generate Cpd I. This capability of the N-oxo derivatives of aromatic amines to transfer oxygen to the heme, and thereby generate Cpd I, is in good accord with experimental data previously reported.

  7. Restricted active space calculations of L-edge X-ray absorption spectra: from molecular orbitals to multiplet states.

    Science.gov (United States)

    Pinjari, Rahul V; Delcey, Mickaël G; Guo, Meiyuan; Odelius, Michael; Lundberg, Marcus

    2014-09-28

    The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between metal and ligands, which makes the simulation of spectra challenging. The core restricted active space (RAS) method is an accurate and flexible approach that can be used to calculate X-ray spectra of a wide range of medium-sized systems without any symmetry constraints. Here, the applicability of the method is tested in detail by simulating three ferric (3d(5)) model systems with well-known electronic structure, viz., atomic Fe(3+), high-spin [FeCl6](3-) with ligand donor bonding, and low-spin [Fe(CN)6](3-) that also has metal backbonding. For these systems, the performance of the core RAS method, which does not require any system-dependent parameters, is comparable to that of the commonly used semi-empirical charge-transfer multiplet model. It handles orbitally degenerate ground states, accurately describes metal-ligand interactions, and includes both single and multiple excitations. The results are sensitive to the choice of orbitals in the active space and this sensitivity can be used to assign spectral features. A method has also been developed to analyze the calculated X-ray spectra using a chemically intuitive molecular orbital picture.

  8. Radiation effects and metalloproteins studied by x-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wurzbach, J.A.

    1975-07-01

    X-ray photoelectron spectroscopy (XPS) is used to study the bonding structure at the iron site of cytochrome c and the bonding of rare earth ions to the phosphate oxygens of ATP. Radiation effects are studied on several amino acid and simple peptide model systems. The emission spectrum of the x-ray source is calculated from literature references. The distributions of photon energy as a function of photon frequency and as a function of take-off angle are obtained. From these distributions, the radiation dose absorbed by an organic sample is found to be 10/sup 6/ rads/sec. The C 1s and N 1s spectra of amino acids and peptides are studied to characterize an internal reference standard for protein XPS spectra. Samples of native cytochrome c prepared from solutions of pH 1.5, 3, 7, and 11 are studied. Control samples include porphyrin cytochrome c (PCC), the metal free analogue of the native protein, and microperoxidase (MP), a mixture of heme peptides derived from the peptic digestion of cytochrome c. These samples show two S 2p peaks. The first peak has a binding energy (BE) of 163 eV, which corresponds to the S containing amino acids; the second peak is shifted to 167 eV. This large shift may be the result of Fe-S binding, or oxidation, or both. Low spin ferricytochrome c and ferri-MP were found to have Fe 3p BE's that are unusually low (51 eV) compared to other ferric compounds (54 to 58 eV) and even Fe metal (53 eV). X-ray crystal structures of these compounds show that low spin heme Fe lies in the porphyrin plane; while, high spin heme Fe is displaced above the plane. The N 1s and P 2p spectra of ATP show no change except slight broadening when Nd/sup 3 +/ is substituted for Na/sup +/. Thus, there is no inconsistency with proposals that rare earth ions might be useful as substitutes for alkali metal ions and alkaline earth ions in proteins.

  9. Resonance Raman study on the structure of the active sites of microsomal cytochrome P-450 isozymes LM2 and LM4.

    Science.gov (United States)

    Hildebrandt, P; Greinert, R; Stier, A; Taniguchi, H

    1989-12-08

    The isozymes 2 and 4 of rabbit microsomal cytochrome P-450 (LM2, LM4) have been studied by resonance Raman spectroscopy. Based on high quality spectra, a vibrational assignment of the porphyrin modes in the frequency range between 100-1700 cm-1 is presented for different ferric states of cytochrome P-450 LM2 and LM4. The resonance Raman spectra are interpreted in terms of the spin and ligation state of the heme iron and of heme-protein interactions. While in cytochrome P-450 LM2 the six-coordinated low-spin configuration is predominantly occupied, in the isozyme LM4 the five-coordinated high-spin form is the most stable state. The different stability of these two spin configurations in LM2 and LM4 can be attributed to the structures of the active sites. In the low-spin form of the isozymes LM4 the protein matrix forces the heme into a more rigid conformation than in LM2. These steric constraints are removed upon dissociation of the sixth ligand leading to a more flexible structure of the active site in the high-spin form of the isozyme LM4. The vibrational modes of the vinyl groups were found to be characteristic markers for the specific structures of the heme pockets in both isozymes. They also respond sensitively to type-I substrate binding. While in cytochrome P-450 LM4 the occupation of the substrate-binding pocket induces conformational changes of the vinyl groups, as reflected by frequency shifts of the vinyl modes, in the LM2 isozyme the ground-state conformation of these substituents remain unaffected, suggesting that the more flexible heme pocket can accommodate substrates without imposing steric constraints on the porphyrin. The resonance Raman technique makes structural changes visible which are induced by substrate binding in addition and independent of the changes associated with the shift of the spin state equilibrium: the high-spin states in the substrate-bound and substrate-free enzyme are structurally different. The formation of the inactive form

  10. Radiation effects and metalloproteins studied by x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Wurzbach, J.A.

    1975-07-01

    X-ray photoelectron spectroscopy (XPS) is used to study the bonding structure at the iron site of cytochrome c and the bonding of rare earth ions to the phosphate oxygens of ATP. Radiation effects are studied on several amino acid and simple peptide model systems. The emission spectrum of the x-ray source is calculated from literature references. The distributions of photon energy as a function of photon frequency and as a function of take-off angle are obtained. From these distributions, the radiation dose absorbed by an organic sample is found to be 10 6 rads/sec. The C 1s and N 1s spectra of amino acids and peptides are studied to characterize an internal reference standard for protein XPS spectra. Samples of native cytochrome c prepared from solutions of pH 1.5, 3, 7, and 11 are studied. Control samples include porphyrin cytochrome c (PCC), the metal free analogue of the native protein, and microperoxidase (MP), a mixture of heme peptides derived from the peptic digestion of cytochrome c. These samples show two S 2p peaks. The first peak has a binding energy (BE) of 163 eV, which corresponds to the S containing amino acids; the second peak is shifted to 167 eV. This large shift may be the result of Fe-S binding, or oxidation, or both. Low spin ferricytochrome c and ferri-MP were found to have Fe 3p BE's that are unusually low (51 eV) compared to other ferric compounds (54 to 58 eV) and even Fe metal (53 eV). X-ray crystal structures of these compounds show that low spin heme Fe lies in the porphyrin plane; while, high spin heme Fe is displaced above the plane. The N 1s and P 2p spectra of ATP show no change except slight broadening when Nd 3+ is substituted for Na + . Thus, there is no inconsistency with proposals that rare earth ions might be useful as substitutes for alkali metal ions and alkaline earth ions in proteins

  11. The first TDDFT and MCD studies of free base triarylcorroles: a closer look into solvent-dependent UV-visible absorption.

    Science.gov (United States)

    Ziegler, Christopher J; Sabin, Jared R; Geier, G Richard; Nemykin, Victor N

    2012-05-16

    Absorption spectra of several free base triarylcorroles were investigated by MCD spectroscopy. The MCD spectra exhibit unusual sign-reverse (positive-to-negative intensities in ascending energy) features in the Soret- and Q-type band regions, suggesting a rare ΔHOMO < ΔLUMO relationship between π and π* MOs in the corrole core. This journal is © The Royal Society of Chemistry 2012

  12. Interaction of nitric oxide with human heme oxygenase-1.

    Science.gov (United States)

    Wang, Jinling; Lu, Shen; Moënne-Loccoz, Pierre; Ortiz de Montellano, Paul R

    2003-01-24

    NO and CO may complement each other as signaling molecules in some physiological situations. We have examined the binding of NO to human heme oxygenase-1 (hHO-1), an enzyme that oxidizes heme to biliverdin, CO, and free iron, to determine whether inhibition of hHO-1 by NO can contribute to the signaling interplay of NO and CO. An Fe(3+)-NO hHO-1-heme complex is formed with NO or the NO donors NOC9 or 2-(N,N-diethylamino)-diazenolate-2-oxide.sodium salt. Resonance Raman spectroscopy shows that ferric hHO-1-heme forms a 6-coordinated, low spin complex with NO. The nu(N-O) vibration of this complex detected by Fourier transform IR is only 4 cm(-1) lower than that of the corresponding metmyoglobin (met-Mb) complex but is broader, suggesting a greater degree of ligand conformational freedom. The Fe(3+)-NO complex of hHO-1 is much more stable than that of met-Mb. Stopped-flow studies indicate that k(on) for formation of the hHO-1-heme Fe(3+)-NO complex is approximately 50-times faster, and k(off) 10 times slower, than for met-Mb, resulting in K(d) = 1.4 microm for NO. NO thus binds 500-fold more tightly to ferric hHO-1-heme than to met-Mb. The hHO-1 mutations E29A, G139A, D140A, S142A, G143A, G143F, and K179A/R183A do not significantly diminish the tight binding of NO, indicating that NO binding is not highly sensitive to mutations of residues that normally stabilize the distal water ligand. As expected from the K(d) value, the enzyme is reversibly inhibited upon exposure to pathologically, and possibly physiologically, relevant concentrations of NO. Inhibition of hHO-1 by NO may contribute to the pleiotropic responses to NO and CO.

  13. The influence of the Cys46/Cys55 disulfide bond on the redox and spectroscopic properties of human neuroglobin.

    Science.gov (United States)

    Bellei, Marzia; Bortolotti, Carlo Augusto; Di Rocco, Giulia; Borsari, Marco; Lancellotti, Lidia; Ranieri, Antonio; Sola, Marco; Battistuzzi, Gianantonio

    2018-01-01

    Neuroglobin is a monomeric globin containing a six-coordinate heme b, expressed in the nervous system, which exerts an important neuroprotective role. In the human protein (hNgb), Cys46 and Cys55 form an intramolecular disulfide bond under oxidizing conditions, whose cleavage induces a helix-to-strand rearrangement of the CD loop that strengthens the bond between the heme iron and the distal histidine. Hence, it is conceivable that the intramolecular disulfide bridge modulates the functionality of human neuroglobin by controlling exogenous ligand binding. In this work, we investigated the influence of the Cys46/Cys55 disulfide bond on the redox properties and on the pH-dependent conformational equilibria of hNgb, using UV-vis spectroelectrochemistry, cyclic voltammetry, electronic absorption spectroscopy and magnetic circular dichroism (MCD). We found that the SS bridge significantly affects the heme Fe(III) to Fe(II) reduction enthalpy (ΔH°' rc ) and entropy (ΔS°' rc ), mostly as a consequence of changes in the reduction-induced solvent reorganization effects, without affecting the axial ligand-binding interactions and the polarity and electrostatics of the heme environment. Between pH3 and 12, the electronic properties of the heme of ferric hNgb are sensitive to five acid-base equilibria, which are scarcely affected by the Cys46/Cys55 disulfide bridge. The equilibria occurring at extreme pH values induce heme release, while those occurring between pH5 and 10 alter the electronic properties of the heme without modifying its axial coordination and low spin state. They involve the sidechains of non-coordinating aminoacids close to the heme and at least one heme propionate. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Probing Ligand Exchange in the P450 Enzyme CYP121 from Mycobacterium tuberculosis: Dynamic Equilibrium of the Distal Heme Ligand as a Function of pH and Temperature.

    Science.gov (United States)

    Fielding, Andrew J; Dornevil, Kednerlin; Ma, Li; Davis, Ian; Liu, Aimin

    2017-12-06

    CYP121 is a cytochrome P450 enzyme from Mycobacterium tuberculosis that catalyzes the formation of a C-C bond between the aromatic groups of its cyclodityrosine substrate (cYY). The crystal structure of CYP121 in complex with cYY reveals that the solvent-derived ligand remains bound to the ferric ion in the enzyme-substrate complex. Whereas in the generally accepted P450 mechanism, binding of the primary substrate in the active-site triggers the release of the solvent-derived ligand, priming the metal center for reduction and subsequent O 2 binding. Here we employed sodium cyanide to probe the metal-ligand exchange of the enzyme and the enzyme-substrate complex. The cyano adducts were characterized by UV-vis, EPR, and ENDOR spectroscopies and X-ray crystallography. A 100-fold increase in the affinity of cyanide binding to the enzyme-substrate complex over the ligand-free enzyme was observed. The crystal structure of the [CYP121(cYY)CN] ternary complex showed a rearrangement of the substrate in the active-site, when compared to the structure of the binary [CYP121(cYY)] complex. Transient kinetic studies showed that cYY binding resulted in a lower second-order rate constant (k on (CN) ) but a much more stable cyanide adduct with 3 orders of magnitude slower k off (CN) rate. A dynamic equilibrium between multiple high- and low-spin species for both the enzyme and enzyme-substrate complex was also observed, which is sensitive to changes in both pH and temperature. Our data reveal the chemical and physical properties of the solvent-derived ligand of the enzyme, which will help to understand the initial steps of the catalytic mechanism.

  15. The selenazal drug ebselen potently inhibits indoleamine 2,3-dioxygenase by targeting enzyme cysteine residues.

    Science.gov (United States)

    Terentis, Andrew C; Freewan, Mohammed; Sempértegui Plaza, Tito S; Raftery, Mark J; Stocker, Roland; Thomas, Shane R

    2010-01-26

    The heme enzyme indoleamine 2,3-dioxygenase (IDO) plays an important immune regulatory role by catalyzing the oxidative degradation of l-tryptophan. Here we show that the selenezal drug ebselen is a potent IDO inhibitor. Exposure of human macrophages to ebselen inhibited IDO activity in a manner independent of changes in protein expression. Ebselen inhibited the activity of recombinant human IDO (rIDO) with an apparent inhibition constant of 94 +/- 17 nM. Optical and resonance Raman spectroscopy showed that ebselen altered the active site heme of rIDO by inducing a transition of the ferric heme iron from the predominantly high- to low-spin form and by lowering the vibrational frequency of the Fe-CO stretch of the CO complex, indicating an opening of the distal heme pocket. Substrate binding studies showed that ebselen enhanced nonproductive l-tryptophan binding, while circular dichroism indicated that the drug reduced the helical content and protein stability of rIDO. Thiol labeling and mass spectrometry revealed that ebselen reacted with multiple cysteine residues of IDO. Removal of cysteine-bound ebselen with dithiothreitol reversed the effects of the drug on the heme environment and significantly restored enzyme activity. These findings indicate that ebselen inhibits IDO activity by reacting with the enzyme's cysteine residues that result in changes to protein conformation and active site heme, leading to an increase in the level of nonproductive substrate binding. This study highlights that modification of cysteine residues is a novel and effective means of inhibiting IDO activity. It also suggests that IDO is under redox control and that the enzyme represents a previously unrecognized in vivo target of ebselen.

  16. Metal-porphyrin interactions. VI. The reactivities of several ferric porphyrin monomers with cyanide compared with ligand reactions of iron and cobalt porphyrins reconstituted with proteins. [25/sup 0/

    Energy Technology Data Exchange (ETDEWEB)

    Hambright, P. (Howard Univ., Washington, DC); Chock, P.B.

    1975-01-01

    A study of the hydrolysis and kinetics and equilibrium behavior of cyanide addition to the monomeric iron(III) complexes of meso, proto and deuteroporphyrin-IX in 2 percent sodium lauryl sulfate--0.1 M tetramethyl ammonium bromide, 25/sup 0/ is reported. The reactivity parameters are compared to reactions of the same Co(II) and Fe(II) porphyrin types reconstituted to myoglobins and hemoglobins.

  17. 鲁米诺-[铁氰化钾-亚铁氰化钾]-酚磺乙胺化学发光体系%Chemiluminescence Reaction of Luminol-[Potassium Ferric yanide-Potassium Ferrocyanide]-Ethamsylate System

    Institute of Scientific and Technical Information of China (English)

    李银环; 杜建修; 吕九如

    2002-01-01

    实验发现,酚磺乙胺与鲁米诺在碱性溶液中可产生弱的化学发光,铁氰化钾和亚铁氰化钾的存在对该化学发光反应具有很强的催化作用.基于此,建立了基于鲁米诺-铁氰化钾/亚铁氰化钾-酚磺乙胺体系测定酚磺乙胺的流动注射化学发光新方法.酚磺乙胺浓度在4 .0×10-6~1.0×10-4 g/L范围内与化学发光强度具有线性关系.该方法的检出限为1×10-6 g/L,相对标准偏差为1.4%(2.0×10-5 g/L 酚磺乙胺溶液,n=11).该方法用于止血敏注射液中酚磺乙胺的含量测定,结果令人满意.同时 ,还对可能的化学发光反应机理进行了初步探讨.

  18. Sonochemical synthesis of a multi-responsive regenerable water-stable zinc(II) fluorescent probe for highly selective, sensitive and real-time sensing of benzaldehyde, ferric ion and PH.

    Science.gov (United States)

    Wang, Xin Rui; Wang, Xing Ze; Li, Yong; Liu, Kun; Liu, Shi Xin; Du, Jing; Huang, Zhuo; Luo, Yan; Huo, Jian Zhong; Wu, Xiang Xia; Liu, Yuan Yuan; Ding, Bin

    2018-06-01

    In this work, a novel water-stable coordination polymer with {4 4 } network topology {[Zn(L) 2 (NO 3 ) 2 ]} n (1) (L = 4,4'-Bis(triazol-1-ylmethyl)biphenyl) has been synthesized through the hydrothermal and sonochemical approaches. 1 has been characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy, UV-vis absorption spectrum and scanning electron microscopy (SEM). PXRD patterns of the as-synthesized samples 1 have confirmed the purity of the bulky samples. In the sonochemical preparation approaches, different ultrasound irradiation power and ultrasound time were also used in order to investigate the impact factor for morphology and size of nano-structured 1. Photo-luminescence studies have revealed that 1 can efficiently distinguish Fe 3+ from Fe 2+ and other metal ions. On the other hand, 1 also can exhibit a highly sensitive, excellently selective and real-time detection of benzaldehyde and pH through photo-luminescence quenching process. As for 1, density functional theory (DFT) and time-dependent DFT (TDDFT) theory has been applied to calculate these spectroscopic data, the result agree with the experimental results for detection of benzaldehyde. Photo-luminescent recyclability results indicated 1 can be reused at least five times in the detection process. To the best of our knowledge, this is the first example of a multi-responsive regenerable luminescent sensor for highly selective, sensitive and real-time sensing of Fe 3+ over Fe 2+ , benzaldehyde and pH values. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Synthesis and structure of a ferric complex of 2,6-di(1H-pyrazol-3-yl)pyridine and its excellent performance in the redox-controlled living ring-opening polymerization of ε-caprolactone.

    Science.gov (United States)

    Fang, Yang-Yang; Gong, Wei-Jie; Shang, Xiu-Juan; Li, Hong-Xi; Gao, Jun; Lang, Jian-Ping

    2014-06-14

    The reaction of FeCl3 with a pincer ligand, 2,6-di(1H-pyrazol-3-yl)pyridine (bppyH2), produced a mononuclear Fe(III) complex [Fe(bppyH2)Cl3] (1), which could be reduced to the corresponding Fe(II) dichloride complex [Fe(bppyH2)Cl2] (2) by suitable reducing agents such as Cp2Co or Fe powder. 1 and 2 exhibited a reversible transformation from each other with appropriate redox reagents. 1 could be utilized as a pre-catalyst to initiate the ring-opening polymerization of ε-caprolactone in the presence of alcohol but did not work. The 1/alcohol system displayed characteristics of a well-controlled polymerization with the resulting poly(ε-caprolactone) having low molecular weight distributions, a linear tendency of molecular weight evolution with conversion, and polymer growth observed for the sequential additions of ε-caprolactone monomer to the polymerization reaction. The polymerization was completely turned off by the in situ reduction of the catalytic Fe center via Cp2Co and then turned back upon the addition of [Cp2Fe]PF6. The rate of polymerization was modified by switching in situ between the Fe(III) and Fe(II) species.

  20. Determination of Non-Transferrin Bound Iron, Transferrin Bound Iron, Drug Bound Iron and Total Iron in Serum in a Rats after IV Administration of Sodium Ferric Gluconate Complex by Simple Ultrafiltration Inductively Coupled Plasma Mass Spectrometric Detection

    Directory of Open Access Journals (Sweden)

    Murali K. Matta

    2018-02-01

    Full Text Available A rapid, sensitive and specific ultrafiltration inductively-coupled plasma mass spectrometry method was developed and validated for the quantification of non-transferrin bound iron (NTBI, transferrin bound iron (TBI, drug bound iron (DI and total iron (TI in the same rat serum sample after intravenous (IV administration of iron gluconate nanoparticles in sucrose solution (Ferrlecit®. Ultrafiltration with a 30 kDa molecular cut-off filter was used for sample cleanup. Different elution solvents were used to separate each form of iron from sample serum. Isolated fractions were subjected to inductively-coupled mass spectrometric analysis after microwave digestion in 4% nitric acid. The reproducibility of the method was evaluated by precision and accuracy. The calibration curve demonstrated linearity from 5–500 ng/mL with a regression (r2 of more than 0.998. This method was effectively implemented to quantify rat pharmacokinetic study samples after intravenous administration of Ferrlecit®. The method was successfully applied to a pharmacokinetic (PK study of Ferrlecit in rats. The colloidal iron followed first order kinetics with half-life of 2.2 h and reached background or pre-dose levels after 12 h post-dosing. The drug shown a clearance of 0.31 mL/min/kg and volume of distribution of 0.05 L/kg. 19.4 ± 2.4 mL/h/kg.

  1. Radiolytic and photochemical reduction of carbon dioxide in solution catalyzed by transition metal complexes with some selected macrocycles

    International Nuclear Information System (INIS)

    Grodkowski, J.

    2004-01-01

    The main goal of the work presented in this report is an explanation of the mechanism of carbon dioxide (CO 2 ) reduction catalyzed by transition metal complexes with some selected macrocycles. The catalytic function of two electron exchange centers in the reduction of CO 2 , an inner metal and a macrocycle ring, was defined. Catalytic effects of rhodium, iron and cobalt porphyrins, cobalt and iron phthalocyanines and corroles as well as cobalt corrins have been investigated. CO 2 reduction by iron ions without presence of macrocycles and also in presence of copper compounds in aqueous solutions have been studied as well

  2. Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

    Directory of Open Access Journals (Sweden)

    Nicolas Desbois

    2015-11-01

    Full Text Available The Cu(I-catalysed Huisgen cycloaddition, known as “click” reaction, has been applied to the synthesis of a range of triazole-linked porphyrin/corrole to DOTA/NOTA derivatives. Microwave irradiation significantly accelerates the reaction. The synthesis of heterobimetallic complexes was easily achieved in up to 60% isolated yield. Heterobimetallic complexes were easily prepared as potential MRI/PET (SPECT bimodal contrast agents incorporating one metal (Mn, Gd for the enhancement of contrast for MRI applications and one “cold” metal (Cu, Ga, In for future radionuclear imaging applications. Preliminary relaxivity measurements showed that the reported complexes are promising contrast agents (CA in MRI.

  3. Precipitation pathways for ferrihydrite formation in acidic solutions

    DEFF Research Database (Denmark)

    Zhu, Mengqiang; Frandsen, Cathrine; Wallace, Adam F.

    2016-01-01

    to identify and quantify the long-time sought ferric speciation over time during ferric oxyhydroxide formation in partially-neutralized ferric nitrate solutions ([Fe3+] = 0.2 M, 1.8 ... occurs prior to further condensation leading up to the nucleation of ferrihydrite. The structural reconfiguration is likely the rate-limiting step involved in the nucleation process....

  4. ORF Alignment: NC_003305 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_003305 gi|17937619 >1kmoA 2 661 49 702 6e-54 ... ref|NP_534408.1| exogenous ferric... siderophore receptor [Agrobacterium tumefaciens ... str. C58] gb|AAL44724.1| exogenous ferric sidero...phore ... receptor [Agrobacterium tumefaciens str. C58] ... pir||AF3038 exogenous ferric sider

  5. ORF Alignment: NC_003063 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_003063 gi|15891046 >1kmoA 2 661 49 702 6e-54 ... ref|NP_534408.1| exogenous ferric... siderophore receptor [Agrobacterium tumefaciens ... str. C58] gb|AAL44724.1| exogenous ferric sidero...phore ... receptor [Agrobacterium tumefaciens str. C58] ... pir||AF3038 exogenous ferric sider

  6. ORF Alignment: NC_002927 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002927 gi|33603734 >1kmoA 3 661 60 754 2e-50 ... ref|NP_891294.1| exogenous ferric... siderophore receptor [Bordetella bronchiseptica ... RB50] gb|AAB51774.1| exogenous ferric siderophor...e ... receptor emb|CAE35124.1| exogenous ferric siderophore ... receptor [Bordetella bronchise

  7. Role of Met80 and Tyr67 in the low-pH conformational equilibria of cytochrome c.

    Science.gov (United States)

    Battistuzzi, Gianantonio; Bortolotti, Carlo Augusto; Bellei, Marzia; Di Rocco, Giulia; Salewski, Johannes; Hildebrandt, Peter; Sola, Marco

    2012-07-31

    The low-pH conformational equilibria of ferric yeast iso-1 cytochrome c (ycc) and its M80A, M80A/Y67H, and M80A/Y67A variants were studied from pH 7 to 2 at low ionic strength through electronic absorption, magnetic circular dichroism, and resonance Raman spectroscopies. For wild-type ycc, the protein structure, axial heme ligands, and spin state of the iron atom convert from the native folded His/Met low-spin (LS) form to a molten globule His/H(2)O high-spin (HS) form and a totally unfolded bis-aquo HS state, in a single cooperative transition with an apparent pK(a) of ~3.0. An analogous cooperative transition occurs for the M80A and M80A/Y67H variants. This is preceded by protonation of heme propionate-7, with a pK(a) of ~4.2, and by an equilibrium between a His/OH(-)-ligated LS and a His/H(2)O-ligated HS conformer, with a pK(a) of ~5.9. In the M80A/Y67A variant, the cooperative low-pH transition is split into two distinct processes because of an increased stability of the molten globule state that is formed at higher pH values than the other species. These data show that removal of the axial methionine ligand does not significantly alter the mechanism of acidic unfolding and the ranges of stability of low-pH conformers. Instead, removal of a hydrogen bonding partner at position 67 increases the stability of the molten globule and renders cytochrome c more susceptible to acid unfolding. This underlines the key role played by Tyr67 in stabilizing the three-dimensional structure of cytochrome c by means of the hydrogen bonding network connecting the Ω loops formed by residues 71-85 and 40-57.

  8. Quaternary structure and spin state of human fetal methemoglobin

    International Nuclear Information System (INIS)

    Chevion, M.; Navok, T.; Ilan, Y.A.; Czapski, G.

    1981-01-01

    Using the pulse-radiolysis technique, solutions of fetal human methemoglobin were irradiated in order to reduce a single heme-iron within the protein tetramers. The valence-hybrids thus formed ere reacted wjth oxygen. Kinetics of the reactions were studied. The effects of p and inositol-hexaphosphate (IHP) were examined. The kinetics of the ligation of oxygen to stripped valence-hybrids showed a single-phase behaviour at the pH range 7-9. As the pH was lowered below 6.5, a second slower phase became apparent. This slow phase consisted of approximately 50% at pH 5.8. In the presence of IHP above pH 7.4, the kinetics of oxygen-binding was of a single-phase. As the pH was lowered a transition to a second, slower phase was noticed. Below pH 7 the slower phase was the only detectable one. The analysis of the relative contribution of the faster phase to the total reaction, as a function of the pH, showed a typical sigmoidal transition curve characterized by a pK = 7.2 and a Hill parameter n = 3.06. On this basis it is concluded that stripped, fetal human methemoglobin resides in an R quaternary structure while the presence of IHP stabilizes the T structure at pH below 7.2. The switch between the high spin aquomet- and the low spin hydroxymet-derivatives of adult and fetal human hemoglobins was studied optically in detail. These switches were found to be only slightly affected by IHP, and exhibited very low cooperativity (pK = 8.04; n = 1.1 and pK = 8.10; n = 1.3 for adult methemoglobin when stripped and in the presence of IHP, respectively; pK = 8.18; n = 1.11 and pK = 8.21; n = 1.28 for fetal methemoglobin when stripped and in the presence of IHP, respectively). These findings lead to the conclusion that the transition between quaternary structures in either human or fetal methemoglobins is not coupled to the switch of the spin state of the ferric heme. (author)

  9. Comparison of the sensitivity of mass spectrometry atmospheric pressure ionization techniques in the analysis of porphyrinoids.

    Science.gov (United States)

    Swider, Paweł; Lewtak, Jan P; Gryko, Daniel T; Danikiewicz, Witold

    2013-10-01

    The porphyrinoids chemistry is greatly dependent on the data obtained in mass spectrometry. For this reason, it is essential to determine the range of applicability of mass spectrometry ionization methods. In this study, the sensitivity of three different atmospheric pressure ionization techniques, electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization, was tested for several porphyrinods and their metallocomplexes. Electrospray ionization method was shown to be the best ionization technique because of its high sensitivity for derivatives of cyanocobalamin, free-base corroles and porphyrins. In the case of metallocorroles and metalloporphyrins, atmospheric pressure photoionization with dopant proved to be the most sensitive ionization method. It was also shown that for relatively acidic compounds, particularly for corroles, the negative ion mode provides better sensitivity than the positive ion mode. The results supply a lot of relevant information on the methodology of porphyrinoids analysis carried out by mass spectrometry. The information can be useful in designing future MS or liquid chromatography-MS experiments. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Combined MCD/DFT/TDDFT Study of the Electronic Structure of Axially Pyridine Coordinated Metallocorroles.

    Science.gov (United States)

    Rhoda, Hannah M; Crandall, Laura A; Geier, G Richard; Ziegler, Christopher J; Nemykin, Victor N

    2015-05-18

    A series of metallocorroles were investigated by UV-vis and magnetic circular dichroism spectroscopies. The diamagnetic distorted square-pyramidal main-group corrole Ga(tpfc)py (2), the diamagnetic distorted octahedral transition-metal adduct Co(tpfc)(py)2 (3), and paramagnetic distorted octahedral transition-metal complex Fe(tpfc)(py)2 (4) [H3tpfc = tris(perfluorophenyl)corrole] were studied to investigate similarities and differences in the electronic structure and spectroscopy of the closed- and open-shell metallocorroles. Similar to the free-base H3tpfc (1), inspection of the MCD Faraday B-terms for all of the macrocycles presented in this report revealed that a ΔHOMO MCD spectra. In addition, the MCD spectra of the cobalt and the iron complexes were also complicated by a number of charge-transfer states in the visible region. Iron complex 4 also exhibits a low-energy absorption in the NIR region (1023 nm). DFT and TDDFT calculations were used to elaborate the electronic structures and provide band assignments in UV-vis and MCD spectra of the metallocorroles. DFT and TDDFT calculations predict that the orientation of the axial pyridine ligand(s) has a very minor influence on the calculated electronic structures and absorption spectra in the target systems.

  11. Positive parity states and some electromagnetic transition properties of even-odd europium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Yazar, Harun Resit, E-mail: yazar@nevsehir.edu.tr [Nevsehir University, Faculty of Art and Science (Turkey)

    2013-06-15

    The positive-parity low-spin states of even-odd Europium isotopes ({sup 151-155}Eu) were studied within the framework of the interacting boson-fermion model. The calculated positive low-spin state energy spectra of the odd Eu isotope were found to agree quite well with the experimental data. The B(E2) values were also calculated and it was found that the calculated positive-parity low-spin state energy spectra of the odd-A Eu isotopes agree quite well with the experimental data.

  12. Mean field approach to nuclear structure

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Tennessee Univ., Knoxville, TN

    1993-01-01

    Several examples of mean-field calculations, relevant to the recent and planned low-spin experimental works, are presented. The perspectives for future studies (mainly related to spectroscopy of exotic nuclei) are reviewd

  13. Overview of experimental research on nuclear structure in department of modern applied physics

    International Nuclear Information System (INIS)

    Zhu Shengjiang

    1999-01-01

    The experimental research on nuclear structure in Department of Modern Applied Physics, Tsinghua University has been summarized. The main research results in high spin states of nuclear structure, as well as some low spin states, have been reported

  14. Use of novel composite coagulants for arsenic removal from waters : experimental insight for the application of polyferric sulfate (PFS)

    OpenAIRE

    Katsoyiannis, Ioannis A.; Tzollas, Nikolaos M.; Tolkou, Athanasia K.; Mitrakas, Manassis; Ernst, Mathias; Zouboulis, Anastasios I.

    2017-01-01

    In the present study, several pre-polymerized coagulants of iron and aluminum were tested for their efficiency towards As(V) and As(III) removal from water sources. The results showed that the pre-polymerized coagulants of iron, such as poly-ferric sulfate and poly-ferric silicate chloride, were very efficient for As(V) removal. With regard to As(III) removal, among all examined coagulants, including the conventional ferric chloride, only the poly-ferric sulfate (PFS) was able to reduce As(II...

  15. Compositions and methods for removing arsenic in water

    Science.gov (United States)

    Gadgil, Ashok Jagannth [El Cerrito, CA

    2011-02-22

    Compositions and methods and for contaminants from water are provided. The compositions comprise ferric hydroxide and ferric oxyhydride coated substrates for use in removing the contaminant from the water. Contacting water bearing the contaminant with the substrates can substantially reduce contaminant levels therein. Methods of oxidizing the contaminants in water to facilitate their removal by the ferric hydroxide and ferric oxyhydride coated substrates are also provided. The contaminants include, but are not limited to, arsenic, selenium, uranium, lead, cadmium, nickel, copper, zinc, chromium and vanadium, their oxides and soluble salts thereof.

  16. Hangman Catalysis for Photo- and Photoelectro- Chemical Activation of Water

    Energy Technology Data Exchange (ETDEWEB)

    Nocera, Daniel

    2014-04-15

    The focus of this DOE program is solar fuels – specifically the chemistry for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) from water and the oxygen reduction reaction (ORR) to water These three reactions are at the heart of renewable energy conversion. The bond-making and bond-breaking chemistry that underpins these transformations is not well understood. We are developing insight into such chemistry by creating a series of ligand constructs that poise an acid-base functionality over a redox active metal platform. These “hangman” ligands utilize the acid-base functionality to form a secondary coordination sphere that can assist proton movement and facilitate substrate assembly and activation within the molecular cleft. The grant period funding cycle focused on synthesis and reactivity of hangman porphyrins and corroles for HER, OER and ORR.

  17. Association between Peritonsillar Abscess and Molar Caries

    Directory of Open Access Journals (Sweden)

    M Shayani Nasab

    2006-05-01

    Full Text Available Background: Peritonsillar abscess is the most common deep neck infections that are related with periodontal disease which has the same pathogenesis. We determined the relationship between peritonsillar infection and molar caries. Methods: In a cross-sectional study, 33 consecutive patients whom referred to Hamadan university clinic of otolaryngologic for peritonsillar abscess were examined by otolaryngologist and dentist who investigated relationship between peritonsillar infection and molar caries. Results: There were 27 males and 6 females with mean age 26.7+_7 years. The frequency caries on ipsilateral peritonsillar infection sides was in relation to molars caries on opposite sides (conterol group. This corrolation was significant with odds ratio 2.5. Conclusion: Molar caries were seen 2.5 times more likely to have peritonsillar infection compared with normal molar sides. Key Words: Peritonsillar abscess, Infection, Periodontal disease, Dental caries

  18. IRON REDUCTASE SYSTEMS ON THE PLANT PLASMA-MEMBRANE - A REVIEW

    NARCIS (Netherlands)

    MOOG, PR; BRUGGEMANN, W

    1994-01-01

    Higher plant roots, leaf mesophyll tissue, protoplasts as well as green algae are able to reduce extra-cellular ferricyanide and ferric chelates. In roots of dicotyledonous and nongraminaceous, monocotyledonous plants, the rate of ferric reduction is increased by iron deficiency. This reduction is

  19. REMOVAL OF HEXAVALENT CHROMIUM FROM DRINKING WATER

    Directory of Open Access Journals (Sweden)

    A. R. Asgari ، F. Vaezi ، S. Nasseri ، O. Dördelmann ، A. H. Mahvi ، E. Dehghani Fard

    2008-10-01

    Full Text Available Removal of chromium can be accomplished by various methods but none of them is cost-effective in meeting drinking water standards. For this study, granular ferric hydroxide was used as adsorbent for removal of hexavalent chromium. Besides, the effects of changing contact time, pH and concentrations of competitive anions were determined for different amounts of granular ferric hydroxide. It was found that granular ferric hydroxide has a high capacity for adsorption of hexavalent chromium from water at pH≤7 and in 90 min contact time. Maximum adsorption capacity was determined to be 0.788 mg Cr+6/g granular ferric hydroxide. Although relatively good adsorption of sulfate and chloride had been specified in this study, the interfering effects of these two anions had not been detected in concentrations of 200 and 400 mg/L. The absorbability of hexavalent chromium by granular ferric hydroxide could be expressed by Freundlich isotherm with R2>0.968. However, the disadvantage was that the iron concentration in water was increased by the granular ferric hydroxide. Nevertheless, granular ferric hydroxide is a promising adsorbent for chromium removal, even in the presence of other interfering compounds, because granular ferric hydroxide treatment can easily be accomplished and removal of excess iron is a simple practice for conventional water treatment plants. Thus, this method could be regarded as a safe and convenient solution to the problem of chromium-polluted water resources.

  20. ACTIVATION AND DETOXIFICATION OF UICC CROCIDOLITE - THE EFFECT OF CONVERSION OF OXIDATION-STATE OF IRON ON THE TOXICITY OF THE FIBERS

    NARCIS (Netherlands)

    GULUMIAN, M; POLLAK, H

    Detoxification of crocidolite, an asbestiform riebeckite with a coating of ferric salt, converted some of the ferrous ions into ferric ions and therefore decreased the activity of the fibres to catalyse the reduction of oxygen and hydrogen peroxide. The H-2-activation of crocidolite fibres on the