Chemistry Commons^™

Role Of Iron In The Mechanism Of Asbestos-Induced Apoptosis In Human Lung And Pleural Target Cells, Aleksander Baldys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Occupational exposure to asbestos has been associated with increased incidence of pulmonary interstitial fibrosis, mesothelioma of the pleura, and bronchogenic carcinoma. Although the mechanism by which asbestos causes cancer remains unknown, iron associated with asbestos is thought to play a role in the pathogenic effects of fibers.

The aim of this research was to examine and compare the asbestos-induced signaling phenomena in relevant human lung and pleural target cells, and to determine the role of iron from asbestos fibers in these events. Exposure of human airway epithelial (A549) cells, human pleural mesothelial (MET5A) cells, and normal human small airway epithelial …

Study Of Structural And Magnetic Properties Of Iron-Rich Mixed Rare-Earth Nddyfe (17-Y-X)Coxsiy Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, M. S. Kim, Qingsheng Cai, William Joseph James

Physics Faculty Research & Creative Works

A series of NdDyFe(17-y-x)CoxSiy solid solutions with = 2 and 3 and = 0.5 1.0 and 1.5 were prepared by induction melting stoichiometric amounts of high-purity elements. The postannealed samples consist of two phases belonging to the space groups R3 m and P63 mmc . The lattice parameters and the unit cell volumes were calculated from the refinements of the magnetic and structural unit cells using the FULLPROF version of the Rietveld program. For a fixed content of Co, the maximum Curie temperatures (305 C to 405 C) were observed in samples with = 1 and having two phases, a …

Morphologic And Magnetic Properties Of Pd₁₀₀₋ₓfeₓ Nanoparticles Prepared By Ultrasound Assisted Electrochemistry, Maribel Guzman, Jean Luc Delplancke, Gary J. Long, Jacques P. Delwiche, Marie Jeanne Hubin-Franskin, Fernande Grandjean

Chemistry Faculty Research & Creative Works

Nanopowdered alloys of Pd_100-xFe_x, with x=4, 6, 8, and 12, have been prepared by ultrasound assisted electrochemistry. The composition of the individual particles, as determined by x-ray fluorescence, and the bulk composition, as determined by atomic absorption, are in agreement within experimental error. Transmission electron microscopy indicates that the nanopowders consist of agglomerates of small grains with a radius of approximately 5 nm, a radius which is confirmed by the broadening of the reflections in the x-ray powder diffraction patterns. X-ray fluorescence analysis of individual grains indicates a homogeneous distribution of palladium and iron throughout the …

A Mössbauer Spectral Study Of The Magnetic Properties Of Ho₂Fe₁₇ And Ho₂Fe₁₇D₃.₈, Gary J. Long, Olivier Isnard, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The Mössbauer spectra of Ho₂Fe₁₇ and Ho₂Fe₁₇D_3.8 have been measured between 4.2 and 295 K and analyzed with a model which takes into account both the disordered nonstoichiometric hexagonal Th₂Ni₁₇-like structure and the basal orientation of the iron magnetic moments. The isomer shifts of the five crystallographically inequivalent iron sites in both Ho₂Fe₁₇ and Ho₂Fe₁₇D_3.8 follow the sequence of Wigner-Seitz cell volumes and their temperature dependence follows the typical second-order Doppler shift. An increase in the weighted average isomer shift …

Synthetic, Structural, Magnetic, And Mössbauer Spectral Study Of {Fe[Hc(3,5-Me2pz)3]2}I2 And Its Spin-State Crossover Behavior, Daniel L. Reger, Christine A. Little, Mark D. Smith, Arnold L. Rheingold, Kin Chung Lam, Thomas L. Concolino, Gary J. Long, Raphaël P. Hermann, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The complex {Fe [HC(3,5-Me₂pz)₃]₂} I₂ (1) has been prepared from the reaction of FeI₂ and HC(3,5-Me₂pz)₃ (pz = pyrazolyl ring) in a 1:2 ratio. The complex is high spin in both the solid state and in solution at ambient temperature. In the solid state, magnetic susceptibility and Mössbauer spectral studies indicate that samples of the complex that have been crystallized and dried change completely from high-spin to low-spin upon cooling below 195 K, with a substantial two-step thermal hysteresis in the transition. The spin-crossover properties of 1 are sample …

Uneven Anodic Dissolution Of Iron Induced By Magnetic Field, Zhan-Peng Lv, De-Lun Huang, Wu Yang

Journal of Electrochemistry

The effects of magnetic field on anodic dissolution of iron in sulfuric acid were studied by potentiostatic polarization measurements and scanning electron microscopy observation. Magnetic field would reduce the surface film coverage fraction on electrode by enhancing the film dissolution process, thus made the electrode prone to active dissolution state. With increasing the applied potentials, magnetic field would accelerate the anodic dissolution, change the oscillation state or passive state to active dissolution state, or maintain the passive state, respectively. Potential for onset of passivation moved in the noble direction when magnetic field was imposed. At specific anodic potentials, denting occurred …

Two-Dimensional Surface Raman Imaging Of A Roughened Iron Electrode In Saline Water, Pei-Gen Cao, Jian-Lin Yao, Jun-Wei Zheng, Bin Ren, Ren-Ao Gu, Zhong-Qun Tian

Journal of Electrochemistry

The analysis of the composite and distribution of iron oxide due to pit corrosion in saline solutions (3.4% NaCl) is of great importance. Many electrochemical methods, XPS, and other photoelectronic techniques have been applied to this domain. Surface enhanced Raman scattering (SERS) spectroscopy can provide the vibrational information of surface species with high sensitivity and is very useful in the study of surface chemistry of iron. Notwithstanding, the application of SERS in iron corrosion is hampered for its SERS-inactivity. Efforts have been devoted to extend the use of SERS to the study of iron.

Study Of The Effects Of Co2(G) On The Fe(Ii)-Luminol Chemiluminescence System: Application To Ultra-Trace Analysis Of Fe(Ii), Sara Beth Lovitz

Honors Theses

The Fe(II)-catalyzed oxidation of luminol has been a well-accepted chemiluminescence method for the trace and ultra-trace analysis of Fe(II) and Fe(III) in natural waters. Investigation into this chemiluminescence system has shown that COlg) is essential to Fe-catalyzed luminol chemiluminescence. In absence of CO2(g) there is no chemiluminescent signal. These reactions worked well in the past because CO2 is present in most laboratory H20 supplies. Intentional saturation of CO2 results in a 5-fold increase for this conventional system. We propose a mechanism for CO 2(g) enhancement that includes formation of a CO2-superoxide intermediate, which serves as the oxidant of luminol to …

Cerium Liii-Edge X-Ray Absorption Study Of The Ceₓfe4-YCoYSb₁₂ Skutterudites, Fernande Grandjean, Gary J. Long, Robert Cortès, Donald T. Morelli, Gregory P. Meisner

Chemistry Faculty Research & Creative Works

The cerium L_III-edge x-ray absorption near-edge spectra of the Ce_xFe_4-yCo_ySb₁₂ compounds have been obtained at 295 K and unambiguously indicate that cerium is in the 4f¹ electronic ground state for all values of 0.22≤x≤0.98 and 0.0≤y≤3.5. This stable trivalent state of cerium is in agreement with the proposed (CeFe₄Sb₁₂) _1-α(Co₄Sb₁₂)α, solid solution structure, in which the cerium atoms are always surrounded by twelve antimony first neighbors and six iron second neighbors, the observed magnetic properties of CeFe₄Sb₁₂ and …

Reply To "Comment On 'Mössbauer Effect Study Of Filled Antimonide Skutterudites'", Gary J. Long, Gary J. Long, Dimitri Hautot, Fernande Grandjean, Donald T. Morelli, Gregory P. Meisner

Chemistry Faculty Research & Creative Works

The temperature dependence of the isomer shift of α-iron between 4.2 and 990 K and of Dy₃Fe₅O₁₂ between 4.2 and 550 K has been analyzed in terms of the Debye model for the second-order Doppler shift, a model in which an additional parameter, the effective vibrating mass, is included. This mass is found equal to 57 g/mol in the ionic compound, Dy₃Fe₅O₁₂, and equal to 60 g/mol in metallic α-iron. The deviation of this mass from 57 g/mol is a measure of the covalency of the metallic bonding in …

The Role Of Iron And Reactive Oxygen Species In Particulate Air Pollution-Dependent Biochemical And Biological Activities, Kevin Richard Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particulate air pollution is known to exacerbate respiratory diseases, such as asthma and chronic obstructive pulmonary disease, in humans. It has been proposed that transition meta ls from inhaled particles may play a role in this exacerbation by generating radical species leading to damage in the lungs.

The aim of this research was to determine the role that iron from particulate air pollution played in the generation of reactive oxygen species and subsequently the induction of inflammatory mediators in cells in culture. The production of reactive oxygen species by particulate air pollution was found to be dependent on the mobilization …

A Study Of Adsorption Kinetics Of Β-Phenylaminopropiophenone On Iron In Acid Solution, Dihua Wang, Xianzhang Bu, Jinyun Zou, Fuxing Gan

Journal of Electrochemistry

The adsorption kinetics of β-phenylaminopropiophenone (PAP) on iron electrode in 0.5 mol/L H₂SO₄ solution with or without Cl^- were investigated by chronoamperometry.

Breakdown Of The Iron Passive Layer By Use Of The Scanning Electrochemical Microscope, David O. Wipf, John W. Still

Publications

The scanning electrochemical microscope (SECM) is used to generate localized corrosion at passivating iron surfaces by using the tip to generate Cl^– ions. Use of the SECM allows the rapid establishment of a locally aggressive chemical environment at a pre-selected site on the iron surface. The susceptibility for passive-layer breakdown and corrosion initiation was examined as a function of the time between the start of the passive-layer growth and the formation of Cl^- ions. The breakdown of the passive-layer was found to depend strongly on the passivation potential and the site of Cl^- formation on the iron …

The Adsorption-Desorption Behaviors Of Β Phenylaminopropiophenone On Iron In Sulphuric Acid Solution, Xianzhang Bu, Dihua Wang, Jinyun Zou, Fuxing Gan

Journal of Electrochemistry

The adsorption-desorption behaviors of β-phenylaminopropiophenone (PAP) on iron in 0.5 mol·L^-1 H₂SO₄ solution with or without halide ions (Cl^-, I^-) were investigated by potentiostatic polarization measurement. The results show that the adsorption of PAP on iron surface follows Flory-Huggins isotherm, the adsorption free energy parameter (f) is positive in H₂SO₄ solution; In the presence of 0.1 mol·L^-1 Cl^-1, when C_PAP ≤ 2×10^-5 mol·L^-1, f＞0. A desorption phenomenon was observed at more positive potential region in anodic polarization curves. Furthermore, the anodic desorption …

Determination Of Wavelength Dependent Quantum Yields For Iron (Iii) Photoreduction In Well Defined Chloride Media, J. Catherine Kneece

Honors Theses

The quantum yields for iron (lII) photoreduction in sodium chloride and sodium perchlorate media were measured as a function of wavelength. The experiments were conducted using natural levels of total iron, less than 300 nM. The results indicate that three species are photochemically active in these media, Fe(OH)+2, FeCl2+and FeCl2+. The quantum yields for (OH)+2 are 0.22 at 300 run and 0.076 at 340 nm. The quantum yields for FeCl+ are 0.048 at 300 run and 0.038 at 340 nm. The quantum yields for FeCl2+ are 0.088 at 300 nm and 0.051 at 340 nm. The data presented suggests that …

Iron-Dithiothreitol Dependent Production Of 8-Hydroxy-2'-Deoxyguanosine In Dna, David Allan Cook

Undergraduate Honors Capstone Projects

Oxidative damage to DNA in a metal-thiol system was studied. Calf thymus DNA was incubated in an iron(IIl)-dithiothreitol system prepared in various buffers. Damage was measured by monitoring the production of 8-hydroxy-2'-deoxyguanosine. DNA oxidation was proportional to the concentration of dithiothreitol (DTT) in HEPES and tris(hydroxymethyl)aminomethane (Tris) buffers while it was only roughly related to DTT concentration in sodium chloride. Incubation in potassium phosphate buffer produced no damage. The results indicate that hydroxyl radicals may be generated by the iron-OTT system in HEPES, Tris, and sodium chloride, while in the phosphate buffer an iron phosphate complex may be formed which …

Effect Of Iron Binding On The Ability Of Crocidolite To Cause Dna Single-Strand Breaks, Jeanne Ann Hardy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fibrous carcinogens, such as crocidolite asbestos, are known to catalyze many of the same reactions as iron, namely O₂ consumption, generation of reduced oxygen species, and damage to DNA, such as strand breaks, and modifications of bases. Upon inhalation, fibers are also known to become coated with an iron-rich material. The mechanism by which this iron is bound to fibers in the lung is not known, and the effect of this additional iron on the reactivity of the fibers is also not well understood. The studies described here were undertaken to elucidate the abilities of crocidolite asbestos, in its …

Investigations Of Iron Cycling In Aquatic Systems, Heather A. Lounsbury

Honors Theses

A fully automated luminal-based chemiluminescence flow injection analysis system has been developed for rapid detection of Fe(IT) at natural levels in natural water systems. Similar detection limits are achieved for H202 by fluorometry using an enzyme mediated oxidation of the reagent p-hydroxyphenylacetic acid. Using these analytical systems, the rates of Fe(IT) oxidation by dissolved oxygen in 0.7 M NaO have been measured for nanomolar concentrations of Fe(II) over the pH range 7.0 to 8.3. When the production and decomposition of H202 in the system were considered, measured rates were in excellent agreement with a model based on previously reported rate …

Mobilization Of Iron Enhances The Iron-Dependent Biochemical Reactivity Of Asbestos In Vitro And Contributes To The Cytotoxicity Of Asbestos In Cultured Cells, Loren Glen Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Asbestos related research began approximately 60 years ago, yet, the mechanism(s) by which asbestos exerts its biological effects is not well understood. The hypothesis upon which this dissertation is based is that mobilization of iron from asbestos enhances the iron-dependent biochemical reactivity of asbestos in vitro and contributes to asbestos-dependent cytotoxicity. The specific aims for this hypothesis were, 1) to determine whether iron was responsible for the biochemical reactivity of asbestos in vitro and asbestos-induced cytotoxicity in cultured cells, and 2) to determine whether mobilization of iron from asbestos enhanced the reactions catalyzed by asbestos in vitro and contributes to …

The Transport And Intracellular Distribution Of Iron In The Basidiomycete, Ustilago Sphaerogena, Charles W. Passavant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The transport and intracellular distribution of iron in Ustilago sphaerogena via the native siderochrome ferrichrome A has been examined. Evidence is presented which suggests the involvement of deferriferrichrome in iron transport when the metal is supplied to the cell as ferrichrome A. This process requires both oxygen and ATP synthesis and may require a transmembrane electrochemical gradient. Once inside the cell, iron derived from ferrichrome A is rapidly distributed, with a major fraction found in the mitochondria, presumably as heme.

The kinetics of ferrichrome and ferrichrome A uptake have also been investigated. The Km of transport of ferrichrome was …

Characterization Of Trace Iron Species In Natural Water, James Robert Johnson

Dissertations and Theses

The distribution and speciation of trace metals in natural waters is only slightly, at best, understood. Interactions with organic substances can effectively distribute the metals throughout many ill-defined physical and chemical. To better comprehend the complexity of metal-organic interactions this work focused on the delineation of trace iron species present in a natural system. The separation of Fe(II) and Fe(III) was successfully accomplished using a variation of an ion exchange method involving resin-loaded filter paper. The quantitation of the various iron species was determined using linear scan voltammetry and atomic absorption. The total iron concentration, determined as the sum of …

An Fe (Iii) - Initiated Oxidase Reaction With Ferroxidase-Ii, Glenn Alexander Hegamyer

Master's Theses

A reaction involving iron as an intermediary electron carrier for the coupling of electron transfer from an endogenous substrate to ferroxidase-I has been proposed.

The enzymic nature of the reacti on has been established and studies with iron chelating agents have demonstrated the involvement of Fe(III). The kinetic parameters of ferroxidase-11 with Fe (lll) were found to be quite similar to those previously established for Fe(Il). The participation by the copper associated with ferroxi dase-11 was ascertained by use of the copper chelating agent, diethyl -di thio-carbamate .

A variety of substances normally found in blood were surveyed as possible …

Noble Gases: A Record Of The Early Solar System, E. C. Alexander

Doctoral Dissertations

"Analyses of the noble gases in samples of iron meteorites are presented which indicate the following: 1. The inclusions of iron meteorites contain noble gases with a wide range of isotopic compositions. 2. The noble gas concentration and isotopic anomalies arc often grossly inhomogeneously distributed within a given inclusion and vary from inclusion to inclusion in a meteorite. 3. Silicate inclusions appear to be the most promising samples for I-Xe and Pu-Xe dating. 4. Graphite and troilite in addition to the silicate inclusion contain significant radiogenic ¹²⁹Xe anomalies. 5. The total I-Xe (and in the case of Toluca silicates total …

Gravimetric Analysis, Walter M. Lauer

Chemistry Honors Papers

This 16 page thesis examines gravimetric quantitative analyses of various metals.