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The detection of Fe ions is of great significance for monitoring environmental hazards and disease diagnosis. Herein, a new organic molecule (4,12-diphenylnaphtho-[2,1,8-mna]acridine) with quantum yields up to 68% was obtained by tandem cyclization synthetic strategy, and the fluorescent sensor for highly sensitive and selective detection of Fe.sup.3+ has been demonstrated. Interestingly, the fluorescence red shifted significantly, and the solution changed from colorless to yellowish green in the presence of Fe.sup.3+, indicating that the synthesized compound can detect Fe.sup.3+ with the naked eye. Furthermore, according to the Stern- Volmer equation, the quenching constant K.sub.SV was calculated to be 1.78 x 10.sup.5 M.sup.-1. The limit of detection of the sensor for Fe.sup.3+ is 0.6 [mu]M, which is lower than the detection limit currently reported for most organic molecules. In addition, we have shown that the synthesized organic molecule exhibits high photoresponsivity. This interesting property enables it to be applied in optoelectronic device fields, which offers alternative selectivity for the multifunctional application of 4,12-diphenylnaphtho-[2,1,8-mna]acridine., Author(s): Lidong Shan [sup.1] , Baozhen Li [sup.2] , Wei Fu [sup.3] Author Affiliations: (1) grid.12527.33, 0000 0001 0662 3178, Department of Chemistry, Tsinghua University, , 100084, Beijing, China (2) [...]

Progressive iron accumulation and renal impairment are prominent in both patients and mouse models of sickle cell disease (SCD). Endothelin A receptor (ETA) antagonism prevents this iron accumulation phenotype and reduces renal iron deposition in the proximal tubules of SCD mice. To better understand the mechanisms of iron metabolism in the kidney and the role of the [ET.sub.A] receptor in iron chelation and transport, we studied renal iron handling in a nonsickle cell iron overload model, heme oxygenase-1 ([Hmox-1.sup.-/-]) knockout mice. We found that [Hmox-1.sup.-/-] mice had elevated plasma endothelin-1 (ET-1), cortical ET-1 mRNA expression, and renal iron content compared with [Hmox-1.sup.+/+] controls. The [ET.sub.A] receptor antagonist, ambrisentan, attenuated renal iron deposition, without any changes to anemia status in Hmox-1mice. This was accompanied by reduced urinary iron excretion. Finally, ambrisentan had an important iron recycling effect by increasing the expression of the cellular iron exporter, ferroportin-1 (FPN-1), and circulating total iron levels in [Hmox-1.sup.-/-] mice. These findings suggest that the ET-1/[ET.sub.A] signaling pathway contributes to renal iron trafficking in a murine model of iron overload. Keywords: endothelin-1, iron homeostasis, ferroportin-1, sickle cell disease L'accumulation progressive de fer et l'insuffisance renale progressive se retrouvent de maniere proeminente chez les patients atteints d'anemie falciforme (AF) comme dans les modeles de la maladie chez la souris. L'antagonisme des recepteurs de l'endotheline A (ETA) permet de prevenir ce phenotype d'accumulation de fer et d'attenuer le depot de fer au niveau des tubules proximaux des reins de souris AF. Afin de mieux comprendre les modes d'action du metabolisme du fer dans les reins et le role des recepteurs [ET.sub.A] dans la chelation et le transport du fer, nous avons etudie la gestion du fer renal dans un modele de surcharge en fer sans AF : la souris << knock-out >> heme oxygenase 1 ([Hmox-1.sup.-/-]). Nous avons observe que la souris [Hmox-1.sup.-/-] presentait des taux plasmatiques d'endotheline 1 (ET-1), une expression corticale d'ET-1 en ARNm et des taux de fer dans les reins plus eleves que les temoins [Hmox-1.sup.+/+]. L'ambrisentane, un antagoniste des recepteurs ETA, permettait d'attenuer le depot de fer dans les reins sans aucune modification de l'etat anemique des souris [Hmox-1.sup.-/-], ce qui s'accompagnait d'une diminution de l'excretion urinaire du fer. Enfin, l'ambrisentane avait un important effet de recyclage du fer par l'entrainement d'un accroissement de l'expression de la ferroportine 1 (FPN-1), un exportateur de fer cellulaire, de meme que des taux de fer en circulation chez les souris [Hmox-1.sup.-/-]. Ces resultats laissent entendre que la voie de signalisation ET-1/ETA participerait au trafic du fer renal dans un modele de surcharge en fer chez la souris. Mots-cles : endotheline-1, homeostasie du fer, ferroportine 1, anemie falciforme, Introduction Iron homeostasis is fundamental for physiological processes in the body, and its imbalance has severe health consequences. Thus, iron metabolism is tightly regulated at the systemic and cellular levels. [...]

ABSTRACT. A newly constructed building with an open-loop geothermal system outflow stream on campus provides a powerful context for student driven experimentation in an environmental chemistry course. In less than [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.06.019 Byline: Nicola Moraci, Paolo S. CalabrA[sup.2] Abstract: Long-term behaviour is a major issue related to the use of zero-valent iron (ZVI) in permeable reactive barriers for groundwater remediation; in fact, in several published cases the hydraulic conductivity and removal efficiency were progressively reduced during operation, potentially compromising the functionality of the barrier. To solve this problem, the use of granular mixtures of ZVI and natural pumice has recently been proposed. This paper reports the results of column tests using aqueous nickel and copper solutions of various concentrations. Three configurations of reactive material (ZVI only, granular mixture of ZVI and pumice, and pumice and ZVI in series) are discussed. The results clearly demonstrate that iron-pumice granular mixtures perform well both in terms of contaminant removal and in maintaining the long-term hydraulic conductivity. Comparison with previous reports concerning copper removal by ZVI/sand mixtures reveals higher performance in the case of ZVI/pumice. Author Affiliation: Mechanic and Materials Department, Mediterranean University of Reggio Calabria, Faculty of Engineering, Via Graziella, loc. Feo di Vito, 89122 Reggio Calabria (RC), Italy Article History: Received 11 March 2010; Revised 21 June 2010; Accepted 22 June 2010

Byline: Xinmiao Zhao (1), Hongfu Zhang (1), Xiangkun Zhu (2), Suohan Tang (2), Yanjie Tang (1) Keywords: Iron isotopes; Mantle xenoliths; Lithospheric mantle; Mantle metasomatism; North China Craton Abstract: Iron isotopes, together with mineral elemental compositions of spinel peridotite xenoliths and clinopyroxenites from Hannuoba and Hebi Cenozoic alkaline basalts, were analyzed to investigate iron isotopic features of the lithospheric mantle beneath the North China Craton. The results show that the Hannuoba spinel peridotite xenoliths have small but distinguishable Fe isotopic variations. Overall variations in [delt[a].sup.57]Fe are in a range of -0.25 to 0.14[per thousand] for olivine, -0.17 to 0.17[per thousand] for orthopyroxene, -0.21 to 0.27[per thousand] for clinopyroxene, and -0.16 to 0.26[per thousand] for spinel, respectively. Clinopyroxene has the heaviest iron isotopic ratio and olivine the lightest within individual sample. No clear linear relationships between the mineral pairs on '[delta]-[delta]' plot suggest that iron isotopes of mineral separates analyzed have been affected largely by some open system processes. The broadly negative correlations between mineral iron isotopes and metasomatic indexes such as spinel Cr , (La/Yb).sub.N ratios of clinopyroxenes suggest that iron isotopic variations in different minerals and peridotites were probably produced by mantle metasomatism. The Hebi phlogopite-bearing lherzolite, which is significantly modified by metasomatic events, appears to be much heavier isotopically than clinopyroxene-poor lherzolite. This study further confirms previous conclusions that the lithospheric mantle has distinguishable and heterogeneous iron isotopic variations at the xenoliths scale. Mantle metasomatism is the most likely cause for the iron isotope variations in mantle peridotites. Author Affiliation: (1) State Key Laboratory of Lithopheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, 100029, Beijing, China (2) Laboratory of Isotopic Geology, MLR, Institute of Geology, Chinese Academy of Geological Sciences, 100037, Beijing, China Article History: Registration Date: 26/10/2009 Received Date: 12/12/2008 Accepted Date: 26/10/2009 Online Date: 16/11/2009 Article note: Communicated by F. Poitrasson. Electronic supplementary material The online version of this article (doi: 10.1007/s00410-009-0461-y) contains supplementary material, which is available to authorized users. An erratum to this article can be found at http://dx.doi.org/10.1007/s00410-010-0488-0

Byline: Christian Tegner (1), R. Grant Cawthorn (2) Abstract: The evolved, iron-rich rocks of the tholeiitic Bushveld and Skaergaard intrusions are similar in containing cumulus magnetite, ilmenite, plagioclase, clinopyroxene, apatite and olivine, and also orthopyroxenes/pigeonite in Bushveld. Here, we evaluate their liquid evolution trends using the total iron content in plagioclase determined by electron microprobe analyses. To aid this analysis a revised mass balance model for the liquid evolution of Skaergaard is presented. For plagioclase in the Upper Zone of Skaergaard it was previously demonstrated that total FeO increases from ~0.25 to ~0.45 wt% with differentiation and correlates inversely with An% [100 x Ca/(Na + Ca)]. The reverse trend is observed in two recently published datasets for Bushveld, showing that total FeO in plagioclase decreases upward through the magnetite-bearing Upper Zone from ~0.30 to ~0.15% and from ~0.40 to ~0.25% in the western and northern limbs, respectively, and correlates positively with An%. The partition coefficient of total iron between plagioclase and magma increases with oxidation and polymerisation in the liquid. Although Bushveld formed under slightly more oxidizing conditions than Skaergaard, differences in the partition coefficients cannot explain the two observed trends. We therefore conclude that the differentiation trends of the liquids subsequent to magnetite saturation were fundamentally different. The inferred liquid composition for Bushveld contained about 15 wt% total FeO at the level of magnetite-in, which is slightly less than the total FeO content of the subsequent cumulates. In contrast, the Skaergaard liquid contained more total FeO than the ensuing cumulates. As a result, in Bushveld residual liquids total FeO decreased after magnetite saturation, whereas in Skaergaard the residual liquids continued to become enriched in iron. This conclusion is corroborated by simple mass balance calculations between modelled residual liquids and extracted cumulate rocks. Despite the mineralogical similarities of evolved iron-rich rocks of Skaergaard and Bushveld, their liquid evolution trends were very different, and generalizations about the extent of iron enrichment in tholeiitic magmas should be avoided. Author Affiliation: (1) Department of Earth Sciences, Aarhus University, Hogh-Guldbergsgade 2, 8000, Arhus C, Denmark (2) School of Geosciences, University of the Witwatersrand, P.O. WITS 2050, Johannesburg, South Africa Article History: Registration Date: 01/10/2009 Received Date: 14/05/2009 Accepted Date: 30/09/2009 Online Date: 17/10/2009 Article note: Communicated by J. Hoefs. Electronic supplementary material The online version of this article (doi: 10.1007/s00410-009-0450-1) contains supplementary material, which is available to authorized users.

Byline: Mirjam Kan Parker (1), Axel Liebscher (2,3), Dirk Frei (3,4), Jelle Sijl (1), Wim Westrenen (1), Jon Blundy (5), Gerhard Franz (2) Keywords: Orthopyroxene; Partition coefficient; Experimental determination; Computer simulations; Substitution mechanisms Abstract: Although orthopyroxene (Opx) is present during a wide range of magmatic differentiation processes in the terrestrial and lunar mantle, its effect on melt trace element contents is not well quantified. We present results of a combined experimental and computational study of trace element partitioning between Opx and anhydrous silicate melts. Experiments were performed in air at atmospheric pressure and temperatures ranging from 1,326 to 1,420degC in the system [CaO--MgO--Al.sub.2]O.sub.3--SiO.sub.2 and subsystem CaO--MgO--SiO.sub.2. We provide experimental partition coefficients for a wide range of trace elements (large ion lithophile: Li, Be, B, K, Rb, Sr, Cs, Ba, Th, U rare earth elements, REE: La, Ce, Nd, Sm, Y, Yb, Lu high field strength: Zr, Nb, Hf, Ta, Ti transition metals: Sc, V, Cr, Co) for use in petrogenetic modelling. REE partition coefficients increase from D.sub.La.sup.Opx - melt 0.0005 to D.sub.Lu.sup.Opx - melt 0.109 , D values for highly charged elements vary from D.sub.Th.sup.Opx - melt 0.0026 through D.sub.Nb.sup.Opx - melt 0.0033 and D.sub.U.sup.Opx - melt 0.0066 to D.sub.Ti.sup.Opx - melt 0.058 , and are all virtually independent of temperature. Cr and Co are the only compatible trace elements at the studied conditions. To elucidate charge-balancing mechanisms for incorporation of REE into Opx and to assess the possible influence of Fe on Opx-melt partitioning, we compare our experimental results with computer simulations. In these simulations, we examine major and minor trace element incorporation into the end-members enstatite ([Mg.sub.2][Si.sub.2]O.sub.6) and ferrosilite ([Fe.sub.2][Si.sub.2]O.sub.6). Calculated solution energies show that R.sup.2+ cations are more soluble in Opx than R.sup.3+ cations of similar size, consistent with experimental partitioning data. In addition, simulations show charge balancing of R.sup.3+ cations by coupled substitution with Li.sup.+ on the M1 site that is energetically favoured over coupled substitution involving Al--Si exchange on the tetrahedrally coordinated site. We derived best-fit values for ideal ionic radii r .sub.0, maximum partition coefficients D .sub.0, and apparent Young's moduli E for substitutions onto the Opx M1 and M2 sites. Experimental r .sub.0 values for R.sup.3+ substitutions are 0.66--0.67 A for M1 and 0.82--0.87 A for M2. Simulations for enstatite result in r .sub.0 = 0.71--0.73 A for M1 and ~0.79--0.87 A for M2. Ferrosilite r .sub.0 values are systematically larger by ~0.05 A for both M1 and M2. The latter is opposite to experimental literature data, which appear to show a slight decrease in r.sub.0.sup.M2 in the presence of Fe. Additional systematic studies in Fe-bearing systems are required to resolve this inconsistency and to develop predictive Opx-melt partitioning models for use in terrestrial and lunar magmatic differentiation models. Author Affiliation: (1) Faculty of Earth and Life Science, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands (2) Institut fur Angewandte Geowissenschaften, Technische Universitat Berlin, Ernst-Reuter-Platz 1, 10587, Berlin, Germany (3) GFZ German Research Centre for Geosciences, Telegrafenberg, 14473, Potsdam, Germany (4) Geological Survey of Denmark and Greenland (GEUS), Aster Voldgade 10, 1350, Copenhagen K, Denmark (5) CETSEI, Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ, United Kingdom Article History: Registration Date: 04/08/2009 Received Date: 20/04/2009 Accepted Date: 04/08/2009 Online Date: 22/08/2009 Article note: Communicated by J. Hoefs.

A methodology to evaluate hysteresis losses in iron sheets under de-biased inductions is presented in this work. Based on several experimental investigations of six different iron sheets used in the fabrication of electrical machines, an improvement of the classical Steinmetz equation is proposed. This technique can be easily employed and may be helpful for electrical machine designers. Index Terms--DC-biased inductions, hysteresis losses, iron losses.

Carbonyl iron (CI) based magnetorheological (MR) fluid systems possess some disadvantages including severe sedimentation of the CI particles due to their large density mismatch with the carrier liquid and difficulties in redispersion after caking. In order to not only prevent sedimentation but also enhance re-dispersion of pure magnetic CI particles in MR fluid, hybrid magnetic particles of CI/poly(methyl methacrylate) (PMMA) were prepared via a suspension polymerization method of methyl methacrylate. Since the composite particles of CI-PMMA have a lower density than that of pure CI particles, they are regarded to improve the sedimentation problem of magnetic particles in the MR fluid. Both CI and CI-PMMA particles were dispersed in mineral oil (20 vol %) and their MR characteristics were examined via a rotational rheometer with a magnetic field supplier. Various characterizations of the CI-PMMA particles were performed via SEM and FT-IR. Shear stress as a function of shear rate of the MR fluid was investigated under magnetic field strengths exhibiting typical MR performance. Index Terms--Carbonyl iron, composite, magnetorheology, poly(methyl methacrylate).

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2008.03.011 Byline: P.N. Sedwick (a)(b), A.R. Bowie (c)(d), T.W. Trull (b)(c)(e) Keywords: Iron; Southern Ocean; Antarctic Zone; Sea ice; Polar waters Abstract: We report measurements of dissolved iron (dFe, Author Affiliation: (a) Bermuda Institute of Ocean Sciences, St. George's GE 01, Bermuda (b) IASOS, University of Tasmania, Hobart, Tasmania, Australia (c) Antarctic Climate and Ecosystems CRC, Hobart, Tasmania, Australia (d) ACROSS, University of Tasmania, Hobart, Tasmania, Australia (e) CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia Article History: Received 7 February 2006; Revised 26 March 2008; Accepted 30 March 2008

This paper investigated how government influenced firms and firms influenced government. The context was the natural environment. The paper found that as government regulatory forced increase, firms chose to acquiesce or compromise. Further, as the government relaxed regulatory pressures, firms attempted to manipulate the government in their own interest. Also, as firms attempted to manipulate the government in their own interest, the government relaxed regulatory pressures. Finally, as firms chose to acquiesce or compromise, the government increased regulatory forces. The findings buttressed neo-institutional theorists in that the institutional forces studied did not lead to isomorphism. The analysis found that firms met changes in the institutional environment with a large array of strategies, ranging from acquiescence and compromise to manipulation. When studied over time, the relationships further illuminated the beliefs of neo-institutional thinkers. When the government chose to apply aggressive regulatory forces, firms responded by acquiescing or compromising, leading to more government pressure which resulted in more acquiescence and compromise. As governments decreased regulatory pressures, firms attempted to manipulate the government, which lead to relaxation of regulatory forces by the government. Thus, over time, the combined firm-government field became increasingly less isomorphic. KEY WORDS: Longitudinal, government, regulation, business strategy, INTRODUCTION The study's first objective was to investigate how governments' regulatory forces impacted firm strategy. Second, this paper considered how changes in firms' compliance strategies influenced governments' regulatory forces. Third, [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2005.12.002 Byline: Edward R. Sholkovitz (a), Peter N. Sedwick (b) Keywords: Iron; Sea water; Aerosols; Buoy systems; In situ instrumentation; Air-water exchange; Sargasso Sea; Western North Atlantic; Bermuda Abstract: We report results from the first deployment of a buoy-mounted aerosol sampler on the Bermuda Testbed Mooring (BTM) in the Sargasso Sea, in which a time-series of 21 aerosol samples were collected over the period May 5-September 29, 2004. These aerosol samples were analyzed for iron and soluble sodium (as a proxy for sea salt). Also analyzed was a time-series of 22 aerosol samples collected over the same period at the Tudor Hill atmospheric sampling tower on Bermuda. The buoy sampler worked as intended and successfully collected a time-series of aerosol samples, thus demonstrating that moored buoys can be used as oceanic observatories to provide information on the temporal (weekly, monthly and seasonal) variability in the concentration of aerosol iron (and other trace elements) over the surface ocean. The magnitude and time variation of aerosol Fe concentrations calculated from the BTM buoy samples are in close agreement with the corresponding aerosol Fe record from the Tudor Hill tower, which is located approximately 80km northwest of the mooring site. Both the BTM and Tudor Hill samples record periods of high aerosol iron loadings in late June and late July 2004, reflecting the transport of soil dust from North Africa, with the highest concentration of aerosol iron at the BTM site (0.83[mu]gm.sup.-3) measured in late June. Concentrations of sea-salt aerosol calculated from the BTM samples are comparable to values measured over the Sargasso Sea and for samples collected at the Tudor Hill tower. Sea-salt aerosols do not appear to impede the collection of mineral aerosols by the buoy-mounted sampler. Author Affiliation: (a) Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02541, USA (b) Bermuda Biological Station for Research, St. Georges GE01, Bermuda Article History: Received 19 July 2005; Revised 19 December 2005; Accepted 21 December 2005

Abstract -- A thick-film graphite-containing electrode modified with calomel was proposed for determining iron(III) by stripping voltammetry. Of the organic reagents under study, pyrocatechol was found to be the most [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2004.11.010 Byline: Jason M. Lenes, John J. Walsh, Daniel B. Otis, Kendall L. Carder Keywords: Trichodesmium; Saharan dust; Iron; Biogeochemical cycles; Modeling; Barbados; Caribbean; Western North Atlantic Abstract: A one-dimensional quasi-Eulerian model, describing the biological and chemical interactions of autotrophic and heterotrophic plankton populations within the upper 100m of the water column, was used to explain the relative impact of iron fertilization from Saharan dust on phosphorus cycling by the cyanobacterium, Trichodesmium spp. We examined the Caribbean surface waters off the west coast of Barbados using seasonal cases of dust delivery (summer peak) in relation to periods of elevated phosphorus stocks found in episodic pulses of Amazon River water advected past Barbados by the Guiana Current. The additional iron and phosphorus supplied by fluvial sources, available after biological depletion of nitrogen, could alleviate the growth limitation of Trichodesmium far downstream of the river plumes. The model results were compared with measurements made of Trichodesmium stocks 8km off the west coast of Barbados. Modeled concentrations within the low-salinity Amazon plumes reached [approximately equal to]7.4mgchlm.sup.-2, as seen at Barbados. In the absence of the low-salinity signal, the Trichodesmium biomass shifted to phosphorus limitation with little response to iron fertilization. This indicates that Trichodesmium stocks may indeed be mainly a function of phosphorus availability within the upper water column. Therefore, the supply of phosphorus from subtropical/tropical rivers, such as the Amazon and Orinoco, limits the potential cyanophyte response, despite adequate atmospheric iron delivery. This alters our view not only of the western North Atlantic nitrogen budget, but potentially several regions downstream of low N:P river systems. Author Affiliation: College of Marine Science, University of South Florida, 140 Seventh Avenue South, St. Petersburg, FL, 33701-5016, USA Article History: Received 23 April 2004; Revised 13 September 2004; Accepted 20 November 2004

A spectroelectrochemical sensor with attenuated total reflectance at an indium-doped tin oxide (ITO) optically transparent electrode coated with a thin film of Nation has been demonstrated for the determination of aqueous iron ion. The novelty of this sensor stems from its ability to take up colorless iron ion ([Fe.sup.2+]) from solution and complex it with an organic ligand, 2,2'-bipyridine (bipy), that has been previously loaded in the optically transparent charge-selective Nafion film coating the electrode. The resulting complex ion, tris(2,2'-bipyridyl)iron(II), Fe[(bipy).sup.2+.sub.3], absorbs strongly, making it easily detectable via optical spectroscopy. Fe[(bipy).sup.2+.sub.3] loaded into the selective film is oxidized to colorless Fe[(bipy).sup.3+.sub.3], which gives rise to an absorbance change for quantifying iron. This paper maps the development of this sensor, from the spectroelectrochemical characterization of the complex ion at an ITO optically transparent electrode to an analysis of the uptake, retention, and optical response of the complex ion in the Nation film. Finally, an evaluation of the uptake of aqueous [Fe.sup.2+] by the bipy-loaded Nation film is reported. These data include preliminary results illustrating the dependence of the sensor response on differing concentrations of [Fe.sup.2+] in solution.

Research has been conducted on the nitrogenase Fe protein. The effect of this protein redox state on the ADP-ribosylation regulation in Klebsiella pneumoniae strain is discussed.

Research has been conducted on the marine bacteria. The growth of this bacteria under iron-limited conditions has been investigated.

Research has been conducted on the kynurenine pathway catabolites. The reaction of these catabolites with iron and copper and interactions with alpha-crystallins have been investigated.

Research has been conducted on the heterodimeric iron protein. The contributions provided by the iron protein subunits to the events controlled by hydrolysis and nucleotide binding have been studied.

Research has been conducted on the green sulfur bacteria Chlorobium tepidum and Prosthecochloris aestuarii. Electron transfer in the reaction center core complexes from these bacteria has been examined.

Research has been conducted on human lactoferrin (Lf) and serum transferrin (Tf). The iron-release profiles for Lf, Tf and their N-lobe half-molecules have been examined.

Research has been conducted on the energy-dependent electron transfer pathway. The use of the electron donor ferrocytochrome c in investigating this pathway is discussed.

Research has been conducted on gene expression global changes in iron-deficient cells of Synechocystis sp. strain PCC 6803. The use of the differential expression method in studying these changes is discussed.

Research has been conducted on the O (sub)2 -carrying protein hemethyrin (Hr). Results indicate that a conserved sequence motof in all Hrs provides histidine and carboxylate ligands to the diiron active site.

Research has been conducted on the Rieske iron-sulfur protein. Electron transfer between this protein and cytochrome c (sub)1 has been investigated.

Research has been conducted on the biotin and lipoate synthases. The results of Mossbauer studies of (super)57 Fe-reconstituted biotin synthase are presented.

Research has been conducted on the iron-regulatory protein 1 (IRP1). The effect of the nitrogen monoxide donors on IRP1 RNA-binding activity in fibroblast lysates and whole cells.

Research has been conducted on the blue non-heme iron protein superoxide reductase (SOR). The investigation of the crystal structure of SOR in the oxidized and reduced forms is described.

Research has been conducted on the proximal heme iron ligands electronic characteristics in heme proteins. The role of the ligands in oxygen and peroxide activation has been investigated.

Research has been conducted on the effect of histidine ligand of human transferin on iron binding. Site-directed mutagenesis, spectroscopy and structural analysis are examined.

Research has been conducted on the reaction that produces the neutral heterobimetallic complex. The results of the X-ray crystal structure analysis of the reaction are examined.

We show that high-quality powder X-ray diffraction data, collected in diamond anvil cells, provide sufficient information for Rietveld refinement and determination of temperature factors. For the first time using a new method based on combination of thermal equation of state and measured mean-square atomic vibrations of high-pressure (epsilon)-Fe phase, we determine Debye temperatures at pressure up to 300 GPa and temperature over 1000 K. We found that the Gruneisen parameter of (epsilon)-iron could be described by Anderson's (1967) equation with parameters (gamma)(sub 0) = 1.78(6), q = 0.69(10) with fixed V(sub 0) = 6.73 cm(super 3)/mol.

We present a method by which the melting curves and corresponding densities along the liquidus of iron phases are calculated at high pressure. The melting curve of the (epsilon)(hcp) iron phase is calculated from P = 0 to P = 330 GPa. The melting curve of the (gamma)(sub i)(fcc) iron phase is calculated from P = 0 to P = 100 GPa. The point where these curves cross, near P = 50 GPa, is the location of the upper triple point on the melting curve. Our method combines the Lindemann melting equation with the Vinet isothermal equation of state. These equations are coupled by means of the Gruneisen parameter, (gamma) which is given by K'(sub T) (the pressure derivative of the isothermal bulk modulus, K(sub T)) of the equation of state. By this thermodynamic formalism, we find values of volume, V; temperature, T; and the Gruneisen parameter, (gamma) along the melting curve. This calculation requires the following thermal parameters: thermal expansivity, (alpha)(sub v), at high T; (mathematical expression not reproducible in ASCII) at high T; the melting temperature, T(sub m), at P = 0; q = (mathematical expression not reproducible in ASCII) at high T; and (gamma). The method also requires zero-pressure equation-of-state parameters: density, (rho), at T = 300 K; K(sub T) at T = 300 K; and (mathematical expression not reproducible in ASCII) at T = 300 K. Our results do not confirm or deny the existence of the recently proposed (beta) phase. We demonstrate that with our existing knowledge the physical parameters of the (beta) and (epsilon) phases may be so close to each other that these two phases need not be considered separately in discussing the physics of iron at core P,T conditions. We find that one set of reasonable thermoelastic parameters of the (epsilon) phase reproduces the melting temperature and density at pressures of 50 and 240 GPa. Further, these parameters give agreement with previous estimates of the melting temperature and density at 330 GPa.

Based on an in situ X-ray study of Fe and a review of the available data, we propose the following triple-points in the Fe phase diagram - the hexagonal closest packed (HCP), face-centered cubic (FCC), and the (beta) phase: P = 40 (4) GPa at T = 1550 (100) K, the (beta)-phase-FCC-melt; P = 60 (10) GPa at T = 2600 (100) K. We define the stability of (beta) phase from a combination of new X-ray results on externally heated Fe between pressures of 37 to 300 GPa, as well as the previous data on externally heated and laser-heated samples. X-ray data on externally heated Fe, without any pressure medium, confirms the double hexagonal closest packed (DHCP) structure for the (beta) phase. The HCP-(beta) phase boundary has a very small negative dP/dT indicating the similarity of physical properties (molar volume, thermal expansion, and bulk modulus) between the two phrases, but a higher entropy and enthalpy for the (beta) phase.

Research has been conducted on the iron-containing catalase and dismutase enzymes. The purification and characterization of these enzymes that have been expressed by anaerobic bacterium Desulfovibrio gigas are described.

Research has been conducted on the intracellular parasite Legionella pneumophila. Results indicate that L.pneumophila can contain high-affinity iron chelators.

Research has been conducted on the high frequency EPR data for the ferrous complex. A full-matrix diagonalization approach for the spectra simulation is discussed.

Research has been conducted on the heme compounds that are the iron source for neisseriae. The identification of the neisserial gene has been carried out.

Research has been conducted on the Corynebacterium diphtheriae diphtheria toxin repressor. The role of the nucleotide substitutions in the IRP3 operator has been investigated.

Research has been conducted on the salicylic acid. The role of this acid in iron metabolism has been investigated.

Research has been conducted on the active Fe-superoxide dismutase. The isolation of the sodF from the clonal isolate Nostoc commune has been examined.

Research has been conducted on the synthesis and characterization of a new iron(III) phosphate. Urea as a template under hydrothermal conditions is examined.