Sample records for hafnium sulfates

  1. SEPARATING HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Lister, B.A.J.; Duncan, J.F.; Hutcheon, J.M.

    1956-08-21

    Substantially complete separation of zirconium from hafnium may be obtained by elution of ion exchange material, on which compounds of the elements are adsorbed, with an approximately normal solution of sulfuric acid. Preferably the acid concentration is between 0.8 N amd 1.2 N, amd should not exceed 1.5 N;. Increasing the concentration of sulfate ion in the eluting solution by addition of a soluble sulfate, such as sodium sulfate, has been found to be advantageous. The preferred ion exchange materials are sulfonated polystyrene resins such as Dowex 50,'' and are preferably arranged in a column through which the solutions are passed.

  2. Hafnium radioisotope recovery from irradiated tantalum

    DOEpatents

    Taylor, Wayne A.; Jamriska, David J.

    2001-01-01

    Hafnium is recovered from irradiated tantalum by: (a) contacting the irradiated tantalum with at least one acid to obtain a solution of dissolved tantalum; (b) combining an aqueous solution of a calcium compound with the solution of dissolved tantalum to obtain a third combined solution; (c) precipitating hafnium, lanthanide, and insoluble calcium complexes from the third combined solution to obtain a first precipitate; (d) contacting the first precipitate of hafnium, lanthanide and calcium complexes with at least one fluoride ion complexing agent to form a fourth solution; (e) selectively adsorbing lanthanides and calcium from the fourth solution by cationic exchange; (f) separating fluoride ion complexing agent product from hafnium in the fourth solution by adding an aqueous solution of ferric chloride to obtain a second precipitate containing the hafnium and iron; (g) dissolving the second precipitate containing the hafnium and iron in acid to obtain an acid solution of hafnium and iron; (h) selectively adsorbing the iron from the acid solution of hafnium and iron by anionic exchange; (i) drying the ion exchanged hafnium solution to obtain hafnium isotopes. Additionally, if needed to remove residue remaining after the product is dried, dissolution in acid followed by cation exchange, then anion exchange, is performed.

  3. Ablation Resistant Zirconium and Hafnium Ceramics

    NASA Technical Reports Server (NTRS)

    Bull, Jeffrey (Inventor); White, Michael J. (Inventor); Kaufman, Larry (Inventor)

    1998-01-01

    High temperature ablation resistant ceramic composites have been made. These ceramics are composites of zirconium diboride and zirconium carbide with silicon carbide, hafnium diboride and hafnium carbide with silicon carbide and ceramic composites which contain mixed diborides and/or carbides of zirconium and hafnium. along with silicon carbide.

  4. Hafnium isotope stratigraphy of ferromanganese crusts

    PubMed

    Lee; Halliday; Hein; Burton; Christensen; Gunther

    1999-08-13

    A Cenozoic record of hafnium isotopic compositions of central Pacific deep water has been obtained from two ferromanganese crusts. The crusts are separated by more than 3000 kilometers but display similar secular variations. Significant fluctuations in hafnium isotopic composition occurred in the Eocene and Oligocene, possibly related to direct advection from the Indian and Atlantic oceans. Hafnium isotopic compositions have remained approximately uniform for the past 20 million years, probably reflecting increased isolation of the central Pacific. The mechanisms responsible for the increase in (87)Sr/(86)Sr in seawater through the Cenozoic apparently had no effect on central Pacific deep-water hafnium.

  5. SEPARATION OF HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Overholser, L.B.; Barton, C.J. Sr.; Ramsey, J.W.

    1960-05-31

    The separation of hafnium impurities from zirconium can be accomplished by means of organic solvent extraction. The hafnium-containing zirconium feed material is dissolved in an aqueous chloride solution and the resulting solution is contacted with an organic hexone phase, with at least one of the phases containing thiocyanate. The hafnium is extracted into the organic phase while zirconium remains in the aqueous phase. Further recovery of zirconium is effected by stripping the onganic phase with a hydrochloric acid solution and commingling the resulting strip solution with the aqueous feed solution. Hexone is recovered and recycled by means of scrubbing the onganic phase with a sulfuric acid solution to remove the hafnium, and thiocyanate is recovered and recycled by means of neutralizing the effluent streams to obtain ammonium thiocyanate.

  6. Zirconium and hafnium

    USGS Publications Warehouse

    Jones, James V.; Piatak, Nadine M.; Bedinger, George M.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of the main ore mineral zircon (ZrSiO4, or as zirconium oxide or other zirconium chemicals. Zirconium and hafnium are both refractory lithophile elements that have nearly identical charge, ionic radii, and ionic potentials. As a result, their geochemical behavior is generally similar. Both elements are classified as incompatible because they have physical and crystallochemical properties that exclude them from the crystal lattices of most rock-forming minerals. Zircon and another, less common, ore mineral, baddeleyite (ZrO2), form primarily as accessory minerals in igneous rocks. The presence and abundance of these ore minerals in igneous rocks are largely controlled by the element concentrations in the magma source and by the processes of melt generation and evolution. The world’s largest primary deposits of zirconium and hafnium are associated with alkaline igneous rocks, and, in one locality on the Kola Peninsula of Murmanskaya Oblast, Russia, baddeleyite is recovered as a byproduct of apatite and magnetite mining. Otherwise, there are few primary igneous deposits of zirconium- and hafnium-bearing minerals with economic value at present. The main ore deposits worldwide are heavy-mineral sands produced by the weathering and erosion of preexisting rocks and the concentration of zircon and other economically important heavy minerals, such as ilmenite and rutile (for titanium), chromite (for chromium), and monazite (for rare-earth elements) in sedimentary systems, particularly in coastal environments. In coastal deposits, heavy-mineral enrichment occurs where sediment is repeatedly reworked by wind, waves, currents, and tidal processes. The resulting heavy-mineral-sand deposits, called placers or paleoplacers, preferentially form at relatively low latitudes on passive continental margins and supply 100 percent of

  7. Hafnium Oxide Film Etching Using Hydrogen Chloride Gas

    NASA Astrophysics Data System (ADS)

    Habuka, Hitoshi; Yamaji, Masahiko; Kobori, Yoshitsugu; Horii, Sadayoshi; Kunii, Yasuo

    2009-12-01

    Hydrogen chloride gas removes the hafnium oxide film formed by atomic layer deposition at the etch rate of about 1 nm/min. A 100 nm-thick hafnium oxide film was perfectly etched off at 1173 K for 60 min by 100% hydrogen chloride gas at 100 sccm. A weight decrease in the hafnium oxide film was observed at temperatures higher than ca. 600 K, which corresponds to the sublimation point of hafnium tetrachloride. The etching by-product is considered to be hafnium tetrachloride. The etching technique developed in this study is expected to be applicable to various processes, such as the cleaning of a hafnium oxide film deposition reactor.

  8. SEPARATING HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Lister, B.A.J.; Duncan, J.F.

    1956-08-21

    A dilute aqueous solution of zirconyl chloride which is 1N to 2N in HCl is passed through a column of a cation exchange resin in acid form thereby absorbing both zirconium and associated hafnium impurity in the mesin. The cation exchange material with the absorbate is then eluted with aqueous sulfuric acid of a O.8N to 1.2N strength. The first portion of the eluate contains the zirconium substantially free of hafnium.

  9. Formulation and method for preparing gels comprising hydrous hafnium oxide

    DOEpatents

    Collins, Jack L; Hunt, Rodney D; Montgomery, Frederick C

    2013-08-06

    Formulations useful for preparing hydrous hafnium oxide gels contain a metal salt including hafnium, an acid, an organic base, and a complexing agent. Methods for preparing gels containing hydrous hafnium oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including hafnium, an acid, an organic base, and a complexing agent.

  10. Silver-hafnium braze alloy

    DOEpatents

    Stephens, Jr., John J.; Hosking, F. Michael; Yost, Frederick G.

    2003-12-16

    A binary allow braze composition has been prepared and used in a bonded article of ceramic-ceramic and ceramic-metal materials. The braze composition comprises greater than approximately 95 wt % silver, greater than approximately 2 wt % hafnium and less than approximately 4.1 wt % hafnium, and less than approximately 0.2 wt % trace elements. The binary braze alloy is used to join a ceramic material to another ceramic material or a ceramic material, such as alumina, quartz, aluminum nitride, silicon nitride, silicon carbide, and mullite, to a metal material, such as iron-based metals, cobalt-based metals, nickel-based metals, molybdenum-based metals, tungsten-based metals, niobium-based metals, and tantalum-based metals. A hermetic bonded article is obtained with a strength greater than 10,000 psi.

  11. Hafnium-Based Contrast Agents for X-ray Computed Tomography.

    PubMed

    Berger, Markus; Bauser, Marcus; Frenzel, Thomas; Hilger, Christoph Stephan; Jost, Gregor; Lauria, Silvia; Morgenstern, Bernd; Neis, Christian; Pietsch, Hubertus; Sülzle, Detlev; Hegetschweiler, Kaspar

    2017-05-15

    Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry. The superior properties of this asymmetrically substituted hafnium CA were demonstrated by a CT angiography study in rabbits that revealed excellent signal contrast enhancement.

  12. 40 CFR 471.90 - Applicability; description of the zirconium-hafnium forming subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... zirconium-hafnium forming subcategory. 471.90 Section 471.90 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Zirconium-Hafnium Forming Subcategory § 471.90 Applicability; description of the zirconium-hafnium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  13. 40 CFR 421.330 - Applicability: Description of the primary zirconium and hafnium subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... primary zirconium and hafnium subcategory. 421.330 Section 421.330 Protection of Environment ENVIRONMENTAL... CATEGORY Primary Zirconium and Hafnium Subcategory § 421.330 Applicability: Description of the primary zirconium and hafnium subcategory. The provisions of this subpart are applicable to discharges resulting...

  14. Hafnium silicate and hafnium silicon oxynitride gate dielectrics for strained Si_xGe_1-x: Interface stability

    NASA Astrophysics Data System (ADS)

    Addepalli, Swarna; Sivasubramani, Prasanna; El-Bouanani, Mohamed; Kim, Moon; Gnade, Bruce; Wallace, Robert

    2003-03-01

    Strained Si_xGe_1-x layers have gained considerable attention due to hole mobility enhancement, and ease of integration with Si-based CMOS technology. The deposition of stable high-κ dielectrics [1] such as hafnium silicate and hafnium silicon oxynitride in direct contact with SiGe would simultaneously improve the capacitance of the gate stack and lower the leakage current for high performance SiGe devices. However, the oxidation of the Si_xGe_1-x substrate either during dielectric deposition or post-deposition processing would degrade device performance due to the thermodynamic instability of germanium oxide [2,3]. Results from XPS, HR-TEM, and C-V, and I-V analyses after various annealing treatments will be presented for hafnium silicate and hafnium silicon oxynitride films deposited on strained Si_xGe_1-x(100), and correlated with dielectric-Si_xGe_1-x(100) interface stability. Implications to the introduction of these oxides as viable gate dielectric candidates for SiGe-based CMOS technology will be discussed. This work is supported by DARPA through SPAWAR Grant No. N66001-00-1-8928, and the Texas Advanced Technology Program. References: [1] G. D. Wilk, R. M. Wallace and J. M. Anthony, Journal of Applied Physics, 89, 5243 (2001) [2] W. S. Liu, J .S. Chen, M.-A. Nicolet, V. Arbet-Engels, K. L. Wang, Journal of Applied Physics, 72, 4444 (1992), and, Applied Physics Letters, 62, 3321 (1993) [3] W. S. Liu, M. -A. Nicolet, H. -H. Park, B. -H. Koak, J. -W. Lee, Journal of Applied Physics, 78, 2631 (1995)

  15. A simple spectrophotometric method for determination of zirconium or hafnium in selected molybdenum-base alloys

    NASA Technical Reports Server (NTRS)

    Dupraw, W. A.

    1972-01-01

    A simple analytical procedure is described for accurately and precisely determining the zirconium or hafnium content of molybdenum-base alloys. The procedure is based on the reaction of the reagent Arsenazo III with zirconium or hafnium in strong hydrochloric acid solution. The colored complexes of zirconium or hafnium are formed in the presence of molybdenum. Titanium or rhenium in the alloy have no adverse effect on the zirconium or hafnium complex at the following levels in the selected aliquot: Mo, 10 mg; Re, 10 mg; Ti, 1 mg. The spectrophotometric measurement of the zirconium or hafnium complex is accomplished without prior separation with a relative standard deviation of 1.3 to 2.7 percent.

  16. Hafnium(IV) chloride complexes with chelating β-ketiminate ligands: Synthesis, spectroscopic characterization and volatility study

    NASA Astrophysics Data System (ADS)

    Patil, Siddappa A.; Medina, Phillip A.; Antic, Aleks; Ziller, Joseph W.; Vohs, Jason K.; Fahlman, Bradley D.

    2015-09-01

    The synthesis and characterization of four new β-ketiminate hafnium(IV) chloride complexes dichloro-bis[4-(phenylamido)pent-3-en-2-one]-hafnium (4a), dichloro-bis[4-(4-methylphenylamido)pent-3-en-2-one]-hafnium (4b), dichloro-bis[4-(4-methoxyphenylamido)pent-3-en-2-one]-hafnium (4c), and dichloro-bis[4-(4-chlorophenylamido)pent-3-en-2-one]-hafnium (4d) are reported. All the complexes (4a-d) were characterized by spectroscopic methods (1H NMR, 13C NMR, IR), and elemental analysis while the compound 4c was further examined by single-crystal X-ray diffraction, revealing that the complex is monomer with the hafnium center in octahedral coordination environment and oxygens of the chelating N-O ligands are trans to each other and the chloride ligands are in a cis arrangement. Volatile trends are established for four new β-ketiminate hafnium(IV) chloride complexes (4a-d). Sublimation enthalpies (ΔHsub) were calculated from thermogravimetric analysis (TGA) data, which show that, the dependence of ΔHsub on the molecular weight (4a-c) and inductive effects from chlorine (4d).

  17. Hafnium transistor process design for neural interfacing.

    PubMed

    Parent, David W; Basham, Eric J

    2009-01-01

    A design methodology is presented that uses 1-D process simulations of Metal Insulator Semiconductor (MIS) structures to design the threshold voltage of hafnium oxide based transistors used for neural recording. The methodology is comprised of 1-D analytical equations for threshold voltage specification, and doping profiles, and 1-D MIS Technical Computer Aided Design (TCAD) to design a process to implement a specific threshold voltage, which minimized simulation time. The process was then verified with a 2-D process/electrical TCAD simulation. Hafnium oxide films (HfO) were grown and characterized for dielectric constant and fixed oxide charge for various annealing temperatures, two important design variables in threshold voltage design.

  18. Thermochemistry of amorphous and crystalline zirconium and hafnium silicates.

    NASA Astrophysics Data System (ADS)

    Ushakov, S.; Brown, C. E.; Navrotsky, Alexandra; Boatner, L. A.; Demkov, A. A.; Wang, C.; Nguyen, B.-Y.

    2003-03-01

    Calorimetric investigation of amorphous and crystalline zirconium and hafnium silicates was performed as part of a research program on thermochemistry of alternative gate dielectrics. Amorphous hafnium and zirconium silicates with varying SiO2 content were synthesized by a sol-gel process. Crystalline zirconium and hafnium silicates (zircon and hafnon) were synthesized by solid state reaction at 1450 °C from amorphous gels and grown as single crystals from flux. High temperature oxide melt solution calorimetry in lead borate (2PbO.B2O3) solvent at 800 oC was used to measure drop solution enthalpies for amorphous and crystalline zirconium and hafnium silicates and corresponding oxides. Applying appropriate thermochemical cycles, formation enthalpy of crystalline ZrSiO4 (zircon) from binary oxides (baddeleite and quartz) at 298 K was calculated as -23 +/-2 kJ/mol and enthalpy difference between amorphous and crystalline zirconium silicate (vitrification enthalpy) was found to be 61 +/-3 kJ/mol. Crystallization onset temperatures of amorphous zirconium and hafnium silicates, as measured by differential scanning calorimetry (DSC), increased with silica content. The resulting crystalline phases, as characterized by X-ray diffraction (XRD), were tetragonal HfO2 and ZrO2. Critical crystallite size for tetragonal to monoclinic transformation of HfO2 in the gel was estimated as 6 +/-2 nm from XRD data Crystallization enthalpies per mole of hafnia and zirconia in gels decrease slightly together with crystallite size with increasing silica content, for example from -22 to -15 +/-1 kJ per mol of HfO2 crystallized at 740 and 1006 °C from silicates with 10 and 70 mol Applications of thermal analyses and solution calorimetry techniques together with first-principles density functional calculations to estimate interface and surface energies are discussed.

  19. Simultaneous determination of tantalum and hafnium in silicates by neutron activation analysis

    USGS Publications Warehouse

    Greenland, L.P.

    1968-01-01

    A neutron activation procedure suitable for the routine determination of tantalum and hafnium in silicates is described. The irradiated sample is fused with sodium peroxide and leached, and the insoluble hydroxides are dissolved in dilute hydrofluoric acid-hydrochloric acid. After LaF3 and AgCl scavenges, tantalum and hafnium are separated by anion exchange. Tantalum is obtained radiochemically pure; 233Pa and 95Zr contaminants in the hafnium fraction are resolved by ??-ray spectrometry. The chemical yield of the procedure is detemined after counting by re-irradiation. Values for the 8 U.S. Geological Survey standard rocks are reported. ?? 1968.

  20. The Hot-Pressing of Hafnium Carbide (Melting Point, 7030 F)

    NASA Technical Reports Server (NTRS)

    Sanders, William A.; Grisaffe, Salvatore J.

    1960-01-01

    An investigation was undertaken to determine the effects of the hot-pressing variables (temperature, pressure, and time) on the density and grain size of hafnium carbide disks. The purpose was to provide information necessary for the production of high-density test shapes for the determination of physical and mechanical properties. Hot-pressing of -325 mesh hafnium carbide powder was accomplished with a hydraulic press and an inductively heated graphite die assembly. The ranges investigated for each variable were as follows: temperature, 3500 to 4870 F; pressure, 1000 to 6030 pounds per square inch; and time, 5 to 60 minutes. Hafnium carbide bodies of approximately 98 percent theoretical density can be produced under the following minimal conditions: 4230 F, 3500 pounds per square inch, and 15 minutes. Further increases in temperature and time resulted only in greater grain size.

  1. Zirconium and hafnium in the southeastern Atlantic States

    USGS Publications Warehouse

    Mertie, J.B.

    1958-01-01

    The principal source of zirconium and hafnium is zircon, though a minor source is baddeleyite, mined only in Brazil. Zircon is an accessory mineral in igneous, metamorphic, and sedimentary rocks, but rarely occurs in hardrock in minable quantities. The principal sources of zircon are therefore alluvial deposits, which are mined in many countries of five continents. The principal commercial deposits in the United States are in Florida, though others exist elsewhere in the southeastern Coastal Plain. The evidence indicates that conditions for the accumulation of workable deposits of heavy minerals were more favorable during the interglacial stages of the Pleistocene epoch than during Recent time. Therefore detrital ores of large volume and high tenor are more likely to be found in the terrace deposits than along the present beaches. Other concentrations of heavy minerals, however, are possible at favored sites close to the Fall Line where the Tuscaloosa formation rests upon the crystalline rocks of the Piedmont province. A score of heavy and semiheavy minerals occur in the detrital deposits of Florida, but the principal salable minerals are ilmenite, leucoxene, rutile, and zircon, though monazite and staurolite are saved at some mining plants. Commercial deposits of heavy minerals are generally required to have a tenor of 4 percent, though ores with a lower tenor can be mined at a profit if the content of monazite is notably high. The percentages of zircon in the concentrates ranges from 10 to 16 percent, and in eastern Florida from 13 to 15 percent. Thus the tenor in zircon of the ore-bearing sands ranges from 0.4 to 0.6 percent. The content of hafnium in zircon is immaterial for many uses, but for some purposes very high or very low tenors in hafnium are required. Alluvial zircon cannot be separated into such varieties, which, if needed, must be obtained from sources in bedrock. It thus becomes necessary to determine the Hf : Zr ratios in zircon from many kinds of

  2. Separation of Zirconium and Hafnium: A Review

    NASA Astrophysics Data System (ADS)

    Xu, L.; Xiao, Y.; van Sandwijk, A.; Xu, Q.; Yang, Y.

    Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly classified into hydro- and pyrometallurgical routes. The current dominant zirconium production route involves pyrometallurgical ore cracking, multi-step hydrometallurgical liquid-liquid extraction for hafnium removal and the reduction of zirconium tetrachloride to the pure metal by the Kroll process. The lengthy hydrometallurgical Zr-Hf separation operations leads to high production cost, intensive labour and heavy environmental burden. Using a compact pyrometallurgical separation method can simplify the whole production flowsheet with a higher process efficiency. The known separation methods are discussed based on the following reaction features: redox characteristics, volatility, electrochemical properties and molten salt extraction. The commercially operating extractive distillation process is a significant advance in Zr-Hf separation technology but it suffers from high process maintenance cost. The recently developed new process based on molten salt-metal equilibrium for Zr-Hf separation shows a great potential for industrial application, which is compact for nuclear grade zirconium production starting from crude ore. In the present paper, the available separation technologies are compared. The advantages and disadvantages as well as future directions of research and development for nuclear grade zirconium production are discussed.

  3. High P-T phase transitions and P-V-T equation of state of hafnium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hrubiak, Rostislav; Drozd, Vadym; Karbasi, Ali

    2016-07-29

    We measured the volume of hafnium at several pressures up to 67 GPa and at temperatures between 300 to 780 K using a resistively heated diamond anvil cell with synchrotron x-ray diffraction at the Advanced Photon Source. The measured data allows us to determine the P-V-T equation of state of hafnium. The previously described [Xia et al., Phys. Rev. B 42, 6736-6738 (1990)] phase transition from hcp ({alpha}) to simple hexagonal ({omega}) phase at 38 GPa at room temperature was not observed even up to 51 GPa. The {omega} phase was only observed at elevated temperatures. Our measurements have alsomore » improved the experimental constraint on the high P-T phase boundary between the {omega} phase and high pressure bcc ({beta}) phase of hafnium. Isothermal room temperature bulk modulus and its pressure derivative for the {alpha}-phase of hafnium were measured to be B{sub 0} = 112.9{+-}0.5 GPa and B{sub 0}'=3.29{+-}0.05, respectively. P-V-T data for the {alpha}-phase of hafnium was used to obtain a fit to a thermodynamic P-V-T equation of state based on model by Brosh et al. [CALPHAD 31, 173-185 (2007)].« less

  4. Hafnium transistor design for neural interfacing.

    PubMed

    Parent, David W; Basham, Eric J

    2008-01-01

    A design methodology is presented that uses the EKV model and the g(m)/I(D) biasing technique to design hafnium oxide field effect transistors that are suitable for neural recording circuitry. The DC gain of a common source amplifier is correlated to the structural properties of a Field Effect Transistor (FET) and a Metal Insulator Semiconductor (MIS) capacitor. This approach allows a transistor designer to use a design flow that starts with simple and intuitive 1-D equations for gain that can be verified in 1-D MIS capacitor TCAD simulations, before final TCAD process verification of transistor properties. The DC gain of a common source amplifier is optimized by using fast 1-D simulations and using slower, complex 2-D simulations only for verification. The 1-D equations are used to show that the increased dielectric constant of hafnium oxide allows a higher DC gain for a given oxide thickness. An additional benefit is that the MIS capacitor can be employed to test additional performance parameters important to an open gate transistor such as dielectric stability and ionic penetration.

  5. Etude de la nitruration carbothermique du dioxyde de hafnium par diffraction X à haute température

    NASA Astrophysics Data System (ADS)

    Pialoux, A.

    1993-03-01

    The carbothermal reduction of hafnium dioxide under atmospheric level nitrogen pressure has been investigated using a graphite resistance high temperature X-ray diffractometer up to around 2300 K. A carbon transfer reaction through the gaseous phase (N 2, CO/CO 2) is shown to precede, then to compete the direct reduction of the hafnium oxide by the graphite in pure nitrogen. A complex mechanism has been found that accounts for the formation of hafnium dioxynitride and possibly of three other hafnium oxynitrides, then of hafnium mononitride and hafnium monocarbonitride, along two different steps between 1613 and 1923 K. An evaluation has been made concerning the composition of these γ 1- HfO 2-xN x/2□ x/2 (CaF 2-type structure), γ 2- Hf 7O 11N 2, γ 3- Hf 7O 8N 4 (rhombohedral), γ 4- Hf 2ON 2 (Mn 2O 3-type structure), HfN and HfN 1-zC z (NaCl-type structure) phases, considering the variations of their lattice parameters and the available data in the literature, especially on the isomorphous compounds of zirconium. It must be emphasized the new γ 1- HfO 2-xN x/2 phase, the dilatation of which is linear ( overlineα = 12×10 -6K -1), shows a constant composition from 2158 down to 1473 K (x ≈ 0,2). But under 1473 K, inevitably, the hafnium dioxynitride disappears, and poorly crystallized monoclinic αHfO 2 and rhombohedral γ 2- Hf 7O 11N 2 are formed.

  6. RF sputtered silicon and hafnium nitrides as applied to 440C steel

    NASA Technical Reports Server (NTRS)

    Grill, A.; Aron, P. R.

    1984-01-01

    Silicon nitride and hafnium nitride coatings were deposited on oxidized and unoxidized 440C stainless steel substrates. Sputtering was done in mixtures of argon and nitrogen gases from pressed powder silicon nitride and from hafnium metal targets. The coatings and the interface between the coating and substrate were investigated by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis and Auger electron spectroscopy. Oxide was found at all interfaces with an interface width of at least 600 A for the oxidized substrates and at least 300 A for the unoxidized substrates. Scratch test results demonstrate that the adhesion of hafnium nitride to both oxidized and unoxidized 440C is superior to that of silicon nitride. Oxidized 440C is found to have increased adhesion, to both nitrides, over that of unoxidized 440C. Coatings of both nitrides deposited at 8 mtorr were found to have increased adhesion to both oxidized and unoxidized 440C over those deposited at 20 mtorr.

  7. Tensile and stress-rupture behavior of hafnium carbide dispersed molybdenum and tungsten base alloy wires

    NASA Technical Reports Server (NTRS)

    Yun, Hee Mann; Titran, Robert H.

    1993-01-01

    The tensile strain rate sensitivity and the stress-rupture strength of Mo-base and W-base alloy wires, 380 microns in diameter, were determined over the temperature range from 1200 K to 1600 K. Three molybdenum alloy wires; Mo + 1.1w/o hafnium carbide (MoHfC), Mo + 25w/o W + 1.1w/o hafnium carbide (MoHfC+25W) and Mo + 45w/o W + 1.1w/o hafnium carbide (MoHfC+45W), and a W + 0.4w/o hafnium carbide (WHfC) tungsten alloy wire were evaluated. The tensile strength of all wires studied was found to have a positive strain rate sensitivity. The strain rate dependency increased with increasing temperature and is associated with grain broadening of the initial fibrous structures. The hafnium carbide dispersed W-base and Mo-base alloys have superior tensile and stress-rupture properties than those without HfC. On a density compensated basis the MoHfC wires exhibit superior tensile and stress-rupture strengths to the WHfC wires up to approximately 1400 K. Addition of tungsten in the Mo-alloy wires was found to increase the long-term stress rupture strength at temperatures above 1400 K. Theoretical calculations indicate that the strength and ductility advantage of the HfC dispersed alloy wires is due to the resistance to recrystallization imparted by the dispersoid.

  8. Mineral resource of the month: zirconium and hafnium

    USGS Publications Warehouse

    Gambogi, Joseph

    2007-01-01

    Zirconium and hafnium are corrosion-resistant metals that are grouped in the same family as titanium on the periodic table. The two elements commonly occur in oxide and silicate minerals and have significant economic importance in everything from ink, ceramics and golf shoes to nuclear fuel rods.

  9. Effect of cathode cooling efficiency and oxygen plasma gas pressure on the hafnium cathode wall temperature

    NASA Astrophysics Data System (ADS)

    Ashtekar, Koustubh; Diehl, Gregory; Hamer, John

    2012-10-01

    The hafnium cathode is widely used in DC plasma arc cutting (PAC) under an oxygen gas environment to cut iron and iron alloys. The hafnium erosion is always a concern which is controlled by the surface temperature. In this study, the effect of cathode cooling efficiency and oxygen gas pressure on the hafnium surface temperature are quantified. The two layer cathode sheath model is applied on the refractive hafnium surface while oxygen species (O2, O, O+, O++, e-) are considered within the thermal dis-equilibrium regime. The system of non-linear equations comprising of current density balance, heat flux balance at both the cathode surface and the sheath-ionization layer is coupled with the plasma gas composition solver. Using cooling heat flux, gas pressure and current density as inputs; the cathode wall temperature, electron temperature, and sheath voltage drop are calculated. Additionally, contribution of emitted electron current (Je) and ions current (Ji) to the total current flux are estimated. Higher gas pressure usually reduces Ji and increases Je that reduces the surface temperature by thermionic cooling.

  10. Low-voltage bendable pentacene thin-film transistor with stainless steel substrate and polystyrene-coated hafnium silicate dielectric.

    PubMed

    Yun, Dong-Jin; Lee, Seunghyup; Yong, Kijung; Rhee, Shi-Woo

    2012-04-01

    The hafnium silicate and aluminum oxide high-k dielectrics were deposited on stainless steel substrate using atomic layer deposition process and octadecyltrichlorosilane (OTS) and polystyrene (PS) were treated improve crystallinity of pentacene grown on them. Besides, the effects of the pentacene deposition condition on the morphologies, crystallinities and electrical properties of pentacene were characterized. Therefore, the surface treatment condition on dielectric and pentacene deposition conditions were optimized. The pentacene grown on polystyrene coated high-k dielectric at low deposition rate and temperature (0.2-0.3 Å/s and R.T.) showed the largest grain size (0.8-1.0 μm) and highest crystallinity among pentacenes deposited various deposition conditions, and the pentacene TFT with polystyrene coated high-k dielectric showed excellent device-performance. To decrease threshold voltage of pentacene TFT, the polystyrene-thickness on high-k dielectric was controlled using different concentration of polystyrene solution. As the polystyrene-thickness on hafnium silicate decreases, the dielectric constant of polystyrene/hafnium silicate increases, while the crystallinity of pentacene grown on polystyrene/hafnium silicate did not change. Using low-thickness polystyrene coated hafnium silicate dielectric, the high-performance and low voltage operating (<5 V) pentacene thin film transistor (μ: ~2 cm(2)/(V s), on/off ratio, >1 × 10(4)) and complementary inverter (DC gains, ~20) could be fabricated.

  11. Atomic layer deposition and characterization of hafnium oxide grown on silicon from tetrakis(diethylamino)hafnium and water vapor

    NASA Astrophysics Data System (ADS)

    Deshpande, Anand; Inman, Ronald; Jursich, Gregory; Takoudis, Christos

    2004-09-01

    In this work thin films of hafnium oxide are deposited on Si(100) substrates by means of atomic layer deposition (ALD) using tetrakis(diethylamino)hafnium and water vapor at substrate temperatures of 250-350ºC. Our system capabilities include fast transient delivery of reactive fluids, real-time vapor phase detection (in situ tunable diode laser hygrometer), precursor thermochemical capabilities, and ppt level elemental analysis by inductive coupling plasma mass spectrometry. The composition, purity, and other properties of the films and resulting interfaces are determined using x-ray and Fourier transform infrared spectroscopies, Z-contrast imaging and electron energy loss spectroscopy in a scanning transmission electron microscope with A˚ scale resolution, and spectroscopic ellipsometry. The observed ALD rate is ~1.4 A˚ per cycle. The nonuniformity across the film is less than 4%. Negligible carbon contamination is found in the resulting stoichiometric films under all conditions studied. The pulse sequence was optimized to prevent disastrous particulate problems while still minimizing purge times. The film deposition is investigated as a function of substrate temperature and reagent pulsing characteristics. A mild inverse temperature dependence of the ALD rate is observed. The initial stage of the HfO2 growth is investigated in detail.

  12. Review of anhydrous zirconium-hafnium separation techniques. Information circular/1984

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Skaggs, R.L.; Rogers, D.T.; Hunter, D.B.

    1983-12-01

    Sixteen nonaqueous techniques conceived to replace the current aqueous scheme for separating hafnium and zirconium tetrachlorides were reviewed and evaluated by the Bureau of Mines. The methods are divided into two classes: separation by fractional volatilization of the tetrachlorides, which takes advantage of the higher volatility of hafnium tetrachloride; and separation by chemical techniques, based on differences in chemical behavior of the two tetrachlorides. The criteria used to evaluate separation methods were temperature, pressure, separation factor per equilibrium stage, complexity, compatibility with existing technology, and potential for continuous operation. Three processes were selected as being most promising: (1) high-pressure distillation,more » (2) extractive distillation from a molten salt, and (3) preferential reduction of gaseous ZrCl4. Any of the proposed nonaqueous Hf-Zr separation schemes must be supplemented with additional purification to remove trace impurities.« less

  13. Development and characterization of ultrathin hafnium titanates as high permittivity gate insulators

    NASA Astrophysics Data System (ADS)

    Li, Min

    High permittivity or high-kappa materials are being developed for use as gate insulators for future ultrascaled metal oxide semiconductor field effect transistors (MOSFETs). Hafnium containing compounds are the leading candidates. Due to its moderate permittivity, however, it is difficult to achieve HfO2 gate structures with an EOT well below 1.0 nm. One approach to increase HfO2 permittivity is combining it with a very high-kappa material, such as TiO2. In this thesis, we systematically studied the electrical and physical characteristics of high-kappa hafnium titanates films as gate insulators. A series of HfxTi1-xO2 films with well-controlled composition were deposited using an MOCVD system. The physical properties of the films were analyzed using a variety of characterization techniques. X-ray micro diffraction indicates that the Ti-rich thin film is more immune to crystallization. TEM analysis showed that the thick stoichiometric HfTiO 4 film has an orthorhombic structure and large anisotropic grains. The C-V curves from the devices with the hafnium titanates films displayed relatively low hysteresis. In a certain composition range, the interfacial layer (IL) EOT and permittivity of HfxTi1-x O2 increases linearly with increasing Ti. The charge is negative for HfxTi1-xO2/IL and positive for Si/IL interface, and the magnitude increases as Hf increases. For ultra-thin films (less than 2 nm EOT), the leakage current increases with increasing HE Moreover, the Hf-rich sample has weaker temperature dependence of the current. In the MOSFET devices with the hafnium titanates films, normal transistor characteristics were observed, also electron mobility degradation. Next, we investigated the effects that different pre-deposition surface treatments, including HF dipping, NH3 surface nitridation, and HfO2 deposition, have on the electrical properties of hafnium titanates. Surface nitridation shows stronger effect than the thin HfO2 layer. The nitrided samples displayed a

  14. Evidence for oxygen vacancies movement during wake-up in ferroelectric hafnium oxide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Starschich, S.; Böttger, U.; Menzel, S.

    The wake-up effect which is observed in ferroelectric hafnium oxide is investigated in yttrium doped hafnium oxide prepared by chemical solution deposition. It can be shown that not the amount of cycles but the duration of the applied electrical field is essential for the wake-up. Temperature dependent wake-up cycling in a range of −160 °C to 100 °C reveals a strong temperature activation of the wake-up, which can be attributed to ion rearrangement during cycling. By using asymmetrical electrodes, resistive valence change mechanism switching can be observed coincident with ferroelectric switching. From the given results, it can be concluded that redistribution ofmore » oxygen vacancies is the origin of the wake-up effect.« less

  15. Effect of hafnium doping on density of states in dual-target magnetron co-sputtering HfZnSnO thin film transistors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, Chuan-Xin; Li, Jun, E-mail: SHUniverjunli@163.com; Fu, Yi-Zhou

    2015-11-23

    This study investigates the effect of hafnium doping on the density of states (DOSs) in HfZnSnO thin film transistors fabricated by dual-target magnetron co-sputtering system. The DOSs is extracted by temperature-dependent field-effect measurements, and they decrease from 1.1 × 10{sup 17} to 4.6 × 10{sup 16 }eV/cm{sup 3} with increasing the hafnium concentrations. The behavior of DOSs for the increasing hafnium concentration HfZnSnO thin film transistors can be confirmed by both the reduction of ΔV{sub T} under bias stress and the trapping charges calculated by capacitance voltage measurements. It suggests that the reduction in DOSs due to the hafnium doping is closely related with themore » bias stability and thermal stability.« less

  16. Hafnium germanosilicate thin films for gate and capacitor dielectric applications: thermal stability studies

    NASA Astrophysics Data System (ADS)

    Addepalli, Swarna; Sivasubramani, Prasanna; El-Bouanani, Mohamed; Kim, Moon; Gnade, Bruce; Wallace, Robert

    2003-03-01

    The use of SiO_2-GeO2 mixtures in gate and capacitor dielectric applications is hampered by the inherent thermodynamic instability of germanium oxide. Studies to date have confirmed that germanium oxide is readily converted to elemental germanium [1,2]. In sharp contrast, germanium oxide is known to form stable compounds with transition metal oxides such as hafnium oxide (hafnium germanate, HfGeO_4) [3]. Thus, the incorporation of hafnium in SiO_2-GeO2 may be expected to enhance the thermal stability of germanium oxide via Hf-O-Ge bond formation. In addition, the introduction of a transition metal would simultaneously enhance the capacitance of the dielectric thereby permitting a thicker dielectric which reduces leakage current [4]. In this study, the thermal stability of PVD-grown hafnium germanosilicate (HfGeSiO) films was investigated. XPS, HR-TEM, C-V and I-V results of films after deposition and subsequent annealing treatments will be presented. The results indicate that the presence or formation of elemental germanium drastically affects the stability of the HfGeSiO films. This work is supported by DARPA through SPAWAR Grant No. N66001-00-1-8928, and the Texas Advanced Technology Program. References: [1] W. S. Liu, J .S. Chen, M.-A. Nicolet, V. Arbet-Engels, K. L. Wang, Journal of Applied Physics, 72, 4444 (1992), and, Applied Physics Letters, 62, 3321 (1993) [2] W. S. Liu, M. -A. Nicolet, H. -H. Park, B. -H. Koak, J. -W. Lee, Journal of Applied Physics, 78, 2631 (1995) [3] P. M. Lambert, Inorganic Chemistry, 37, 1352 (1998) [4] G. D. Wilk, R. M. Wallace and J. M. Anthony, Journal of Applied Physics, 89, 5243 (2001)

  17. Article having an improved platinum-aluminum-hafnium protective coating

    NASA Technical Reports Server (NTRS)

    Nagaraj, Bangalore Aswatha (Inventor); Williams, Jeffrey Lawrence (Inventor)

    2005-01-01

    An article protected by a protective coating has a substrate and a protective coating having an outer layer deposited upon the substrate surface and a diffusion zone formed by interdiffusion of the outer layer and the substrate. The protective coating includes platinum, aluminum, no more than about 2 weight percent hafnium, and substantially no silicon. The outer layer is substantially a single phase.

  18. Hafnium-Based Bulk Metallic Glasses for Kinetic Energy Penetrators

    DTIC Science & Technology

    2004-12-01

    uranium -based (DU) and tungsten- nickel -iron (W-Ni-Fe) composite kinetic energy (KE) munitions is primarily ascribed to their high densities (U: ρ...based on an invariant point identified in the hafnium- copper- nickel ternary system. They are denser than zirconium-based glass-forming compositions...depleted- uranium penetrators. 1. INTRODUCTION 1.1 Criterion for Effective Kinetic Energy Penetrator Performance The lethality of depleted

  19. Inter-diffusion of copper and hafnium as studied by x-ray photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Pearson, Justin; Chourasia, A. R.

    The Cu/Hf interface has been characterized by x-ray photoelectron spectroscopy. Thin films (thicknesses ranging from 100 nm to 150 nm) of hafnium were deposited on a silicon substrate. About 80 nm of copper was then deposited on such samples. The e-beam method was used for the deposition. The samples were annealed for 30 min at temperatures of 100, 200, 300, 400, and 500°C. The inter-diffusion of copper and hafnium was investigated by sequential sputter depth profiling and x-ray photoelectron spectroscopy. The interdiffusion in each case was analyzed by the Matano-Boltzmann's procedure using the Fick's second law. The interdiffusion coefficients and the width of the interface as determined from the data have been correlated with the annealing temperature. Supported by Organized Research, TAMU-Commerce.

  20. The performance of hafnium and gadolinium self powered neutron detectors in the TREAT reactor

    NASA Astrophysics Data System (ADS)

    Imel, G. R.; Hart, P. R.

    1996-05-01

    The use of gadolinium and hafnium self powered neutron detectors in a transient reactor is described in this paper. The detectors were calibrated to the fission rate of U-235 using calibrated fission chambers; the calibration factors were tested in two reactors in steady state and found to be consistent. Calibration of the detectors in transient reactor conditions was done by using uranium wires that were analyzed by radiochemistry techniques to determine total fissions during the transient. This was correlated to the time-integrated current of the detectors during the transient. A temperature correction factor was derived to account for self-shielding effects in the hafnium and gadolinium detectors. The dynamic response of the detectors under transient conditions was studied, and found to be excellent.

  1. "Decarbonization" of an imino N-heterocyclic carbene via triple benzyl migration from hafnium

    USDA-ARS?s Scientific Manuscript database

    An imino N-heterocyclic carbene underwent three sequential benzyl migrations upon reaction with tetrabenzylhafnium, resulting in complete removal of the carbene carbon from the ligand. The resulting eneamido-amidinato hafnium complex showed alkene polymerization activity comparable to that of a prec...

  2. PROCESS OF RECOVERING ZIRCONIUM VALUES FROM HAFNIUM VALUES BY SOLVENT EXTRACTION WITH AN ALKYL PHOSPHATE

    DOEpatents

    Peppard, D.F.

    1960-02-01

    A process of separating hafnium nitrate from zirconium nitrate contained in a nitric acid solution by selectively. extracting the zirconium nitrate with a water-immiscible alkyl phosphate is reported.

  3. Ferroelectric memory based on molybdenum disulfide and ferroelectric hafnium oxide

    NASA Astrophysics Data System (ADS)

    Yap, Wui Chung; Jiang, Hao; Xia, Qiangfei; Zhu, Wenjuan

    Recently, ferroelectric hafnium oxide (HfO2) was discovered as a new type of ferroelectric material with the advantages of high coercive field, excellent scalability (down to 2.5 nm), and good compatibility with CMOS processing. In this work, we demonstrate, for the first time, 2D ferroelectric memories with molybdenum disulfide (MoS2) as the channel material and aluminum doped HfO2 as the ferroelectric gate dielectric. A 16 nm thick layer of HfO2, doped with 5.26% aluminum, was deposited via atomic layer deposition (ALD), then subjected to rapid thermal annealing (RTA) at 1000 °C, and the polarization-voltage characteristics of the resulting metal-ferroelectric-metal (MFM) capacitors were measured, showing a remnant polarization of 0.6 μC/cm2. Ferroelectric memories with embedded ferroelectric hafnium oxide stacks and monolayer MoS2 were fabricated. The transfer characteristics after program and erase pulses revealed a clear ferroelectric memory window. In addition, endurance (up to 10,000 cycles) of the devices were tested and effects associated with ferroelectric materials, such as the wake-up effect and polarization fatigue, were observed. This research can potentially lead to advances of 2D materials in low-power logic and memory applications.

  4. Hafnium nitride buffer layers for growth of GaN on silicon

    DOEpatents

    Armitage, Robert D.; Weber, Eicke R.

    2005-08-16

    Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 {character pullout}m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.

  5. Studies on Optical and Electrical Properties of Hafnium Oxide Nanoparticles

    NASA Astrophysics Data System (ADS)

    Jayaraman, Venkatachalam; Sagadevan, Suresh; Sudhakar, Rajesh

    2017-07-01

    In this paper, the synthesis and physico-chemical properties of hafnium oxide nanoparticles (HfO2 NPs) are analyzed and reported. The synthesis was carried out by the precipitation route by using hafnium tetrachloride (HfCl4) as precursor material with potassium hydroxide (KOH) dissolved in Millipore water. In the precipitation technique, the chemical reaction is comparatively simple, low-cost and non-toxic compared to other synthetic methods. The synthesized HfO2 NPs were characterized by using powder x-ray diffraction (PXRD), ultraviolet-visible (UV-Vis) spectroscopy, Raman analysis, and high-resolution transmission electron microscopy (HRTEM). The monoclinic structure of the HfO2 NPs was resolved utilizing x-ray diffraction (XRD). The optical properties were studied from the UV-Vis absorption spectrum. The optical band gap of the HfO2NPs was observed to be 5.1 eV. The Raman spectrum shows the presence of HfO2 NPs. The HRTEM image showed that the HfO2 NPs were of spherical shape with an average particle size of around 28 nm. The energy-dispersive x-ray spectroscopy (EDS) spectrum obviously demonstrated the presence of HfO2 NPs. Analysis and studies on the dielectric properties of the HfO2 NPs such as the dielectric constant, the dielectric loss, and alternating current (AC) conductivity were carried out at varying frequencies and temperatures.

  6. Hafnium isotope evidence for a transition in the dynamics of continental growth 3.2 Gyr ago.

    PubMed

    Næraa, T; Scherstén, A; Rosing, M T; Kemp, A I S; Hoffmann, J E; Kokfelt, T F; Whitehouse, M J

    2012-05-30

    Earth's lithosphere probably experienced an evolution towards the modern plate tectonic regime, owing to secular changes in mantle temperature. Radiogenic isotope variations are interpreted as evidence for the declining rates of continental crustal growth over time, with some estimates suggesting that over 70% of the present continental crustal reservoir was extracted by the end of the Archaean eon. Patterns of crustal growth and reworking in rocks younger than three billion years (Gyr) are thought to reflect the assembly and break-up of supercontinents by Wilson cycle processes and mark an important change in lithosphere dynamics. In southern West Greenland numerous studies have, however, argued for subduction settings and crust growth by arc accretion back to 3.8 Gyr ago, suggesting that modern-day tectonic regimes operated during the formation of the earliest crustal rock record. Here we report in situ uranium-lead, hafnium and oxygen isotope data from zircons of basement rocks in southern West Greenland across the critical time period during which modern-like tectonic regimes could have initiated. Our data show pronounced differences in the hafnium isotope-time patterns across this interval, requiring changes in the characteristics of the magmatic protolith. The observations suggest that 3.9-3.5-Gyr-old rocks differentiated from a >3.9-Gyr-old source reservoir with a chondritic to slightly depleted hafnium isotope composition. In contrast, rocks formed after 3.2 Gyr ago register the first additions of juvenile depleted material (that is, new mantle-derived crust) since 3.9 Gyr ago, and are characterized by striking shifts in hafnium isotope ratios similar to those shown by Phanerozoic subduction-related orogens. These data suggest a transitional period 3.5-3.2 Gyr ago from an ancient (3.9-3.5 Gyr old) crustal evolutionary regime unlike that of modern plate tectonics to a geodynamic setting after 3.2 Gyr ago that involved juvenile crust generation by plate

  7. Slow DNA Transport through Nanopores in Hafnium Oxide Membranes

    PubMed Central

    Bell, David C.; Cohen-Karni, Tzahi; Rosenstein, Jacob K.; Wanunu, Meni

    2016-01-01

    We present a study of double- and single-stranded DNA transport through nanopores fabricated in ultrathin (2–7 nm thick) free-standing hafnium oxide (HfO2) membranes. The high chemical stability of ultrathin HfO2 enables long-lived experiments with <2 nm diameter pores that last several hours, in which we observe >50 000 DNA translocations with no detectable pore expansion. Mean DNA velocities are slower than velocities through comparable silicon nitride pores, providing evidence that HfO2 nanopores have favorable physicochemical interactions with nucleic acids that can be leveraged to slow down DNA in a nanopore. PMID:24083444

  8. Cathodoluminescence Study of Hafnium Oxide

    NASA Astrophysics Data System (ADS)

    Purcell, Emily; Hengehold, Robert; McClory, John

    2011-10-01

    Hafnium dioxide (HfO2) is increasingly being used in place of silicon oxide as a gate insulator in field effect transistors. This is primarily due to its high dielectric constant, κ, of 25. Samples of HfO2 were grown by either atomic layer deposition (ALD) or pulsed laser deposition (PLD), with the PLD samples having assorted substrate temperatures during deposition (300 C, 500 C, and 750 C). Cathodoluminescence (CL) was chosen as the technique used for studying these HfO2 samples. The CL system used was capable of beam energies ranging from 1 keV to 20 keV and beam currents ranging from 10 μA to 50 μA. A Monte Carlo calculation using CASINO software was performed in order to determine the beam energy for the desired depth of penetration. Measurements were taken at sample temperatures ranging from 7K (closed cycled cryostat) to 300K (room temperature), as well as at various beam energies and beam currents. Comparison will be made between the PLD and ALD spectra.

  9. Self-cleaning and surface chemical reactions during hafnium dioxide atomic layer deposition on indium arsenide.

    PubMed

    Timm, Rainer; Head, Ashley R; Yngman, Sofie; Knutsson, Johan V; Hjort, Martin; McKibbin, Sarah R; Troian, Andrea; Persson, Olof; Urpelainen, Samuli; Knudsen, Jan; Schnadt, Joachim; Mikkelsen, Anders

    2018-04-12

    Atomic layer deposition (ALD) enables the ultrathin high-quality oxide layers that are central to all modern metal-oxide-semiconductor circuits. Crucial to achieving superior device performance are the chemical reactions during the first deposition cycle, which could ultimately result in atomic-scale perfection of the semiconductor-oxide interface. Here, we directly observe the chemical reactions at the surface during the first cycle of hafnium dioxide deposition on indium arsenide under realistic synthesis conditions using photoelectron spectroscopy. We find that the widely used ligand exchange model of the ALD process for the removal of native oxide on the semiconductor and the simultaneous formation of the first hafnium dioxide layer must be significantly revised. Our study provides substantial evidence that the efficiency of the self-cleaning process and the quality of the resulting semiconductor-oxide interface can be controlled by the molecular adsorption process of the ALD precursors, rather than the subsequent oxide formation.

  10. Aminopyridinate-FI hybrids, their hafnium and titanium complexes, and their application in the living polymerization of 1-hexene.

    PubMed

    Haas, Isabelle; Dietel, Thomas; Press, Konstantin; Kol, Moshe; Kempe, Rhett

    2013-10-11

    Based on two well-established ligand systems, the aminopyridinato (Ap) and the phenoxyimine (FI) ligand systems, new Ap-FI hybrid ligands were developed. Four different Ap-FI hybrid ligands were synthesized through a simple condensation reaction and fully characterized. The reaction of hafnium tetrabenzyl with all four Ap-FI hybrid ligands exclusively led to mono(Ap-FI) complexes of the type [(Ap-FI)HfBn2 ]. The ligands acted as tetradentate dianionic chelates. Upon activation with tris(pentafluorophenyl)borane, the hafnium-dibenzyl complexes led to highly active catalysts for the polymerization of 1-hexene. Ultrahigh molecular weights and extremely narrow polydispersities support the living nature of this polymerization process. A possible deactivation product of the hafnium catalysts was characterized by single-crystal X-ray analysis and is discussed. The coordination modes of these new ligands were studied with the help of model titanium complexes. The reaction of titanium(IV) isopropoxide with ligand 1 led to a mono(Ap-FI) complex, which showed the desired fac-mer coordination mode. Titanium (IV) isopropoxide reacted with ligand 4 to give a complex of the type [(ApH-FI)2 Ti(OiPr)2 ], which featured the ligand in its monoanionic form. The two titanium complexes were characterized by X-ray crystal-structure analysis. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Processing and characterization of boron carbide-hafnium diboride ceramics

    NASA Astrophysics Data System (ADS)

    Brown-Shaklee, Harlan James

    Hafnium diboride based ceramics are promising candidate materials for advanced aerospace and nuclear reactor components. The effectiveness of boron carbide and carbon as HfB2 sintering additives was systematically evaluated. In the first stage of the research, boron carbide and carbon additives were found to improve the densification behavior of milled HfB2 powder in part by removing oxides at the HfB2 surface during processing. Boron carbide additives reduced the hot pressing temperature of HfB2 by 150°C compared to carbon, which reduced the hot pressing temperature by ˜50°C. Reduction of oxide impurities alone could not explain the difference in sintering enhancement, however, and other mechanisms of enhancement were evaluated. Boron carbides throughout the homogeneity range were characterized to understand other mechanisms of sintering enhancement in HfB2. Heavily faulted carbon rich and boron rich boron carbides were synthesized for addition to HfB2. The greatest enhancement to densification was observed in samples containing boron- and carbon-rich compositions whereas B6.5 C provided the least enhancement to densification. It is proposed that carbon rich and boron rich boron carbides create boron and hafnium point defects in HfB2, respectively, which facilitate densification. Evaluation of the thermal conductivity (kth) between room temperature and 2000°C suggested that the stoichiometry of the boron carbide additives did not significantly affect kth of HfB2-BxC composites. The improved sinterability and the high kth (˜110 W/m-K at 300K and ˜90 W/m-K at 1000°C ) of HfB2-BxC ceramics make them excellent candidates for isotopically enriched reactor control materials.

  12. Metal–Organic Nanosheets Formed via Defect-Mediated Transformation of a Hafnium Metal–Organic Framework

    PubMed Central

    2017-01-01

    We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed “double cluster” (Hf12O8(OH)14), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxide frameworks, variable stoichiometry can lead to more complex defect structures, e.g., crystallographic shear planes or modules with differing compositions, which can be the source of further chemical reactivity; likewise, the layered hcp UiO-67 can react further to reversibly form a two-dimensional metal–organic framework, hxl UiO-67. Both three-dimensional hcp UiO-67 and two-dimensional hxl UiO-67 can be delaminated to form metal–organic nanosheets. Delamination of hcp UiO-67 occurs through the cleavage of strong hafnium-carboxylate bonds and is effected under mild conditions, suggesting that defect-ordered MOFs could be a productive route to porous two-dimensional materials. PMID:28343394

  13. Metal-Organic Nanosheets Formed via Defect-Mediated Transformation of a Hafnium Metal-Organic Framework.

    PubMed

    Cliffe, Matthew J; Castillo-Martínez, Elizabeth; Wu, Yue; Lee, Jeongjae; Forse, Alexander C; Firth, Francesca C N; Moghadam, Peyman Z; Fairen-Jimenez, David; Gaultois, Michael W; Hill, Joshua A; Magdysyuk, Oxana V; Slater, Ben; Goodwin, Andrew L; Grey, Clare P

    2017-04-19

    We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed "double cluster" (Hf 12 O 8 (OH) 14 ), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxide frameworks, variable stoichiometry can lead to more complex defect structures, e.g., crystallographic shear planes or modules with differing compositions, which can be the source of further chemical reactivity; likewise, the layered hcp UiO-67 can react further to reversibly form a two-dimensional metal-organic framework, hxl UiO-67. Both three-dimensional hcp UiO-67 and two-dimensional hxl UiO-67 can be delaminated to form metal-organic nanosheets. Delamination of hcp UiO-67 occurs through the cleavage of strong hafnium-carboxylate bonds and is effected under mild conditions, suggesting that defect-ordered MOFs could be a productive route to porous two-dimensional materials.

  14. Glucosamine Sulfate

    MedlinePlus

    ... Glucosamine Sulphate KCl, Glucosamine-6-Phosphate, GS, Mono-Sulfated Saccharide, Poly-(1->3)-N-Acetyl-2-Amino- ... Sulfate de Glucosamine, Sulfate de Glucosamine 2KCl, SG, Sulfated Monosaccharide, Sulfated Saccharide, Sulfato de Glucosamina. Glucosamine Hydrochloride ...

  15. Simultaneous quantification of cholesterol sulfate, androgen sulfates, and progestagen sulfates in human serum by LC-MS/MS.

    PubMed

    Sánchez-Guijo, Alberto; Oji, Vinzenz; Hartmann, Michaela F; Traupe, Heiko; Wudy, Stefan A

    2015-09-01

    Steroids are primarily present in human fluids in their sulfated forms. Profiling of these compounds is important from both diagnostic and physiological points of view. Here, we present a novel method for the quantification of 11 intact steroid sulfates in human serum by LC-MS/MS. The compounds analyzed in our method, some of which are quantified for the first time in blood, include cholesterol sulfate, pregnenolone sulfate, 17-hydroxy-pregnenolone sulfate, 16-α-hydroxy-dehydroepiandrosterone sulfate, dehydroepiandrosterone sulfate, androstenediol sulfate, androsterone sulfate, epiandrosterone sulfate, testosterone sulfate, epitestosterone sulfate, and dihydrotestosterone sulfate. The assay was conceived to quantify sulfated steroids in a broad range of concentrations, requiring only 300 μl of serum. The method has been validated and its performance was studied at three quality controls, selected for each compound according to its physiological concentration. The assay showed good linearity (R(2) > 0.99) and recovery for all the compounds, with limits of quantification ranging between 1 and 80 ng/ml. Averaged intra-day and between-day precisions (coefficient of variation) and accuracies (relative errors) were below 10%. The method has been successfully applied to study the sulfated steroidome in diseases such as steroid sulfatase deficiency, proving its diagnostic value. This is, to our best knowledge, the most comprehensive method available for the quantification of sulfated steroids in human blood. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  16. Simultaneous quantification of cholesterol sulfate, androgen sulfates, and progestagen sulfates in human serum by LC-MS/MS[S

    PubMed Central

    Sánchez-Guijo, Alberto; Oji, Vinzenz; Hartmann, Michaela F.; Traupe, Heiko; Wudy, Stefan A.

    2015-01-01

    Steroids are primarily present in human fluids in their sulfated forms. Profiling of these compounds is important from both diagnostic and physiological points of view. Here, we present a novel method for the quantification of 11 intact steroid sulfates in human serum by LC-MS/MS. The compounds analyzed in our method, some of which are quantified for the first time in blood, include cholesterol sulfate, pregnenolone sulfate, 17-hydroxy-pregnenolone sulfate, 16-α-hydroxy-dehydroepiandrosterone sulfate, dehydroepiandrosterone sulfate, androstenediol sulfate, androsterone sulfate, epiandrosterone sulfate, testosterone sulfate, epitestosterone sulfate, and dihydrotestosterone sulfate. The assay was conceived to quantify sulfated steroids in a broad range of concentrations, requiring only 300 μl of serum. The method has been validated and its performance was studied at three quality controls, selected for each compound according to its physiological concentration. The assay showed good linearity (R2 > 0.99) and recovery for all the compounds, with limits of quantification ranging between 1 and 80 ng/ml. Averaged intra-day and between-day precisions (coefficient of variation) and accuracies (relative errors) were below 10%. The method has been successfully applied to study the sulfated steroidome in diseases such as steroid sulfatase deficiency, proving its diagnostic value. This is, to our best knowledge, the most comprehensive method available for the quantification of sulfated steroids in human blood. PMID:26239050

  17. Reduced Sulfation of Chondroitin Sulfate but Not Heparan Sulfate in Kidneys of Diabetic db/db Mice

    PubMed Central

    Reine, Trine M.; Grøndahl, Frøy; Jenssen, Trond G.; Hadler-Olsen, Elin; Prydz, Kristian

    2013-01-01

    Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes. PMID:23757342

  18. Reduced sulfation of chondroitin sulfate but not heparan sulfate in kidneys of diabetic db/db mice.

    PubMed

    Reine, Trine M; Grøndahl, Frøy; Jenssen, Trond G; Hadler-Olsen, Elin; Prydz, Kristian; Kolset, Svein O

    2013-08-01

    Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.

  19. As-Received, Ozone Cleaned and Ar+ Sputtered Surfaces of Hafnium Oxide Grown by Atomic Layer Deposition and Studied by XPS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Engelhard, Mark H.; Herman, Jacob A.; Wallace, Robert

    2012-06-27

    In this study, X-ray photoelectron spectroscopy (XPS) characterization was performed on 47 nm thick hafnium oxide (HfO{sub 2}) films grown by atomic layer deposition using TEMA-Hf/H{sub 2}O at 250 C substrate temperature. HfO{sub 2} is currently being studied as a possible replacement for Silicon Oxide (SiO{sub 2}) as a gate dielectric in electronics transistors. XPS spectra were collected on a Physical Electronics Quantum 2000 Scanning ESCA Microprobe using a monochromatic Al K{sub a} X-ray (1486.7 eV) excitation source. The sample was analyzed under the following conditions: as received, after UV irradiation for five minutes, and after sputter cleaning with 2more » kV Ar{sup +} ions for 180 seconds. Survey scans showed carbon, oxygen, and hafnium as the major species in the film, while the only minor species of argon and carbide was detected after sputtering. Adventitious carbon initially composed approximately 18.6 AT% of the surface, but after UV cleaning it was reduced to 2.4 AT%. This demonstrated that that the majority of carbon was due to adventitious carbon. However, after 2 kV Ar{sup +} sputtering there was still only trace amounts of carbon at {approx}1 AT%, Some of this trace carbon is now in the form of a carbide due to the interaction with Ar{sup +} used for sputter cleaning. Furthermore, the stoiciometric ratio of oxygen and hafnium is consistent with a high quality HfO{sub 2} film.« less

  20. Hafnium, Tungsten, and the Differentiation of the Moon and Mars

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2003-11-01

    Measurements of the isotopic composition of tungsten (W) show that lunar samples and Martian meteorites have an excess of W-182. This was produced by the decay of hafnium-182 (Hf-182), an isotope with a half-life of only 9 million years. Because tungsten dissolves enthusiastically in metallic iron and hafnium does not, it is possible to use the abundance of W-182 in rocks formed by melting of the silicate mantle as an indicator of the timing of core formation. However, the concentrations of Hf and W in rocky material can be affected by melting and crystallization, so we also need to know how each element concentrates in common minerals in the mantles of the Moon and Mars. The behavior of Hf has been studied experimentally, but this is not true of W. Kevin Righter (Johnson Space Center) and Charles (Chip) Shearer (University of New Mexico) have filled this knowledge void by determining how W partitions between olivine, high- and low-calcium pyroxene, plagioclase feldspar, and garnet. The new data allowed Righter and Shearer to reexamine available measurements of the isotopic composition of W in lunar samples and Martian meteorites. Their analysis suggests that the lunar magma ocean, a huge magma system that surrounded the Moon when it formed, solidified in less than 30 million years. This is shorter than many theoretical calculations suggest. Pathfinder data and chemical data from Martian meteorites suggest that the core of Mars makes up about 20% of the planet. Core formation and subsequent melting of a region of the mantle containing garnet and high-calcium pyroxene took place less than 20-30 million years after the formation of the first solids in the solar system. This type of research shows the importance of measurements of isotopic compositions of radioactive elements or their decay products and laboratory experiments on the geochemical behavior of those elements.

  1. Study of bulk Hafnium oxide (HfO2) under compression

    NASA Astrophysics Data System (ADS)

    Pathak, Santanu; Mandal, Guruprasad; Das, Parnika

    2018-04-01

    Hafnium oxide (HfO2) is a technologically important material. This material has K-value of 25 and band gap 5.8 eV. A k value of 25-30 is preferred for a gate dielectric [1]. As it shows good insulating and capacitive properties, HfO2 is being considered as a replacement to SiO2 in microelectronic devices as gate dielectrics. On the other hand because of toughening mechanism due to phase transformation induced by stress field observed in these oxides, HFO2 has been a material of investigations in various configurations for a very long time. However the controversies about phase transition of HfO2 under pressure still exists. High quality synchrotron radiation has been used to study the structural phase transition of HfO2 under pressure.

  2. Multimode resistive switching in nanoscale hafnium oxide stack as studied by atomic force microscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hou, Y., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn; IMEC, Kapeldreef 75, B-3001 Heverlee; Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee

    2016-07-11

    The nanoscale resistive switching in hafnium oxide stack is investigated by the conductive atomic force microscopy (C-AFM). The initial oxide stack is insulating and electrical stress from the C-AFM tip induces nanometric conductive filaments. Multimode resistive switching can be observed in consecutive operation cycles at one spot. The different modes are interpreted in the framework of a low defect quantum point contact theory. The model implies that the optimization of the conductive filament active region is crucial for the future application of nanoscale resistive switching devices.

  3. Composition effects on mechanical properties of tungsten-rhenium-hafnium-carbon alloys

    NASA Technical Reports Server (NTRS)

    Witzke, W. R.

    1973-01-01

    The mechanical properties of rod and sheet fabricated from arc melted W-4Re-Hf-C alloys containing up to about 0.8 mol percent hafnium carbide (HfC) were evaluated in the as-worked condition. The DBTT's of electropolished bend and tensile specimens were independent of HfC content in this range but dependent on excess Hf or C above that required for stoichiometric HfC. Low temperature ductility was a maximum at Hf contents slightly in excess of stoichiometric. Variations in high temperature strength were also dependent on excess Hf and C. Maximum creep strengthening also occurred at Hf contents in excess of stoichiometric. Analysis of extracted second phase particles indicated that creep strength was reduced by increasing WC content in the HfC particles.

  4. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate and polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a) Specifications. Each milliliter of the ophthalmic preparation contains 5.0 milligrams neomycin sulfate (3.5...

  5. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate and polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a) Specifications. Each milliliter of the ophthalmic preparation contains 5.0 milligrams neomycin sulfate (3.5...

  6. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate and polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a) Specifications. Each milliliter of the ophthalmic preparation contains 5.0 milligrams neomycin sulfate (3.5...

  7. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate and polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a) Specifications. Each milliliter of the ophthalmic preparation contains 5.0 milligrams neomycin sulfate (3.5...

  8. Negative Electron Transfer Dissociation Sequencing of 3-O-Sulfation-Containing Heparan Sulfate Oligosaccharides

    NASA Astrophysics Data System (ADS)

    Wu, Jiandong; Wei, Juan; Hogan, John D.; Chopra, Pradeep; Joshi, Apoorva; Lu, Weigang; Klein, Joshua; Boons, Geert-Jan; Lin, Cheng; Zaia, Joseph

    2018-03-01

    Among dissociation methods, negative electron transfer dissociation (NETD) has been proven the most useful for glycosaminoglycan (GAG) sequencing because it produces informative fragmentation, a low degree of sulfate losses, high sensitivity, and translatability to multiple instrument types. The challenge, however, is to distinguish positional sulfation. In particular, NETD has been reported to fail to differentiate 4-O- versus 6-O-sulfation in chondroitin sulfate decasaccharide. This raised the concern of whether NETD is able to differentiate the rare 3-O-sulfation from predominant 6-O-sulfation in heparan sulfate (HS) oligosaccharides. Here, we report that NETD generates highly informative spectra that differentiate sites of O-sulfation on glucosamine residues, enabling structural characterizations of synthetic HS isomers containing 3-O-sulfation. Further, lyase-resistant 3-O-sulfated tetrasaccharides from natural sources were successfully sequenced. Notably, for all of the oligosaccharides in this study, the successful sequencing is based on NETD tandem mass spectra of commonly observed deprotonated precursor ions without derivatization or metal cation adduction, simplifying the experimental workflow and data interpretation. These results demonstrate the potential of NETD as a sensitive analytical tool for detailed, high-throughput structural analysis of highly sulfated GAGs. [Figure not available: see fulltext.

  9. Significant role of organic sulfur in supporting sedimentary sulfate reduction in low-sulfate environments

    NASA Astrophysics Data System (ADS)

    Fakhraee, Mojtaba; Li, Jiying; Katsev, Sergei

    2017-09-01

    Dissimilatory sulfate reduction (DSR) is a major carbon mineralization pathway in aquatic sediments, soils, and groundwater, which regulates the production of hydrogen sulfide and the mobilization rates of biologically important elements such as phosphorus and mercury. It has been widely assumed that water-column sulfate is the main sulfur source to fuel this reaction in sediments. While this assumption may be justified in high-sulfate environments such as modern seawater, we argue that in low-sulfate environments mineralization of organic sulfur compounds can be an important source of sulfate. Using a reaction-transport model, we investigate the production of sulfate from sulfur-containing organic matter for a range of environments. The results show that in low sulfate environments (<500 μM) the in-sediment production of sulfate can support a substantial portion (>50%) of sulfate reduction. In well-oxygenated systems, porewater sulfate profiles often exhibit sub-interface peaks so that sulfate fluxes are directed out of the sediment. Our measurements in Lake Superior, the world's largest lake, corroborate this conclusion: offshore sediments act as sources rather than sinks of sulfate for the water column, and sediment DSR is supported entirely by the in-sediment production of sulfate. Sulfate reduction rates are correlated to the depth of oxygen penetration and strongly regulated by the supply of reactive organic matter; rate co-regulation by sulfate availability becomes appreciable below 500 μM level. The results indicate the need to consider the mineralization of organic sulfur in the biogeochemical cycling in low-sulfate environments, including several of the world's largest freshwater bodies, deep subsurface, and possibly the sulfate-poor oceans of the Early Earth.

  10. The heparanome--the enigma of encoding and decoding heparan sulfate sulfation.

    PubMed

    Lamanna, William C; Kalus, Ina; Padva, Michael; Baldwin, Rebecca J; Merry, Catherine L R; Dierks, Thomas

    2007-04-30

    Heparan sulfate (HS) is a cell surface carbohydrate polymer modified with sulfate moieties whose highly ordered composition is central to directing specific cell signaling events. The ability of the cell to generate these information rich glycans with such specificity has opened up a new field of "heparanomics" which seeks to understand the systems involved in generating these cell type and developmental stage specific HS sulfation patterns. Unlike other instances where biological information is encrypted as linear sequences in molecules such as DNA, HS sulfation patterns are generated through a non-template driven process. Thus, deciphering the sulfation code and the dynamic nature of its generation has posed a new challenge to system biologists. The recent discovery of two sulfatases, Sulf1 and Sulf2, with the unique ability to edit sulfation patterns at the cell surface, has opened up a new dimension as to how we understand the regulation of HS sulfation patterning and pattern-dependent cell signaling events. This review will focus on the functional relationship between HS sulfation patterning and biological processes. Special attention will be given to Sulf1 and Sulf2 and how these key editing enzymes might act in concert with the HS biosynthetic enzymes to generate and regulate specific HS sulfation patterns in vivo. We will further explore the use of knock out mice as biological models for understanding the dynamic systems involved in generating HS sulfation patterns and their biological relevance. A brief overview of new technologies and innovations summarizes advances in the systems biology field for understanding non-template molecular networks and their influence on the "heparanome".

  11. Pyroelectricity of silicon-doped hafnium oxide thin films

    NASA Astrophysics Data System (ADS)

    Jachalke, Sven; Schenk, Tony; Park, Min Hyuk; Schroeder, Uwe; Mikolajick, Thomas; Stöcker, Hartmut; Mehner, Erik; Meyer, Dirk C.

    2018-04-01

    Ferroelectricity in hafnium oxide thin films is known to be induced by various doping elements and in solid-solution with zirconia. While a wealth of studies is focused on their basic ferroelectric properties and memory applications, thorough studies of the related pyroelectric properties and their application potential are only rarely found. This work investigates the impact of Si doping on the phase composition and ferro- as well as pyroelectric properties of thin film capacitors. Dynamic hysteresis measurements and the field-free Sharp-Garn method were used to correlate the reported orthorhombic phase fractions with the remanent polarization and pyroelectric coefficient. Maximum values of 8.21 µC cm-2 and -46.2 µC K-1 m-2 for remanent polarization and pyroelectric coefficient were found for a Si content of 2.0 at%, respectively. Moreover, temperature-dependent measurements reveal nearly constant values for the pyroelectric coefficient and remanent polarization over the temperature range of 0 ° C to 170 ° C , which make the material a promising candidate for IR sensor and energy conversion applications beyond the commonly discussed use in memory applications.

  12. Roles of Heparan Sulfate Sulfation in Dentinogenesis*

    PubMed Central

    Hayano, Satoru; Kurosaka, Hiroshi; Yanagita, Takeshi; Kalus, Ina; Milz, Fabian; Ishihara, Yoshihito; Islam, Md. Nurul; Kawanabe, Noriaki; Saito, Masahiro; Kamioka, Hiroshi; Adachi, Taiji; Dierks, Thomas; Yamashiro, Takashi

    2012-01-01

    Cell surface heparan sulfate (HS) is an essential regulator of cell signaling and development. HS traps signaling molecules, like Wnt in the glycosaminoglycan side chains of HS proteoglycans (HSPGs), and regulates their functions. Endosulfatases Sulf1 and Sulf2 are secreted at the cell surface to selectively remove 6-O-sulfate groups from HSPGs, thereby modifying the affinity of cell surface HSPGs for its ligands. This study provides molecular evidence for the functional roles of HSPG sulfation and desulfation in dentinogenesis. We show that odontogenic cells are highly sulfated on the cell surface and become desulfated during their differentiation to odontoblasts, which produce tooth dentin. Sulf1/Sulf2 double null mutant mice exhibit a thin dentin matrix and short roots combined with reduced expression of dentin sialophosphoprotein (Dspp) mRNA, encoding a dentin-specific extracellular matrix precursor protein, whereas single Sulf mutants do not show such defective phenotypes. In odontoblast cell lines, Dspp mRNA expression is potentiated by the activation of the Wnt canonical signaling pathway. In addition, pharmacological interference with HS sulfation promotes Dspp mRNA expression through activation of Wnt signaling. On the contrary, the silencing of Sulf suppresses the Wnt signaling pathway and subsequently Dspp mRNA expression. We also show that Wnt10a protein binds to cell surface HSPGs in odontoblasts, and interference with HS sulfation decreases the binding affinity of Wnt10a for HSPGs, which facilitates the binding of Wnt10a to its receptor and potentiates the Wnt signaling pathway, thereby up-regulating Dspp mRNA expression. These results demonstrate that Sulf-mediated desulfation of cellular HSPGs is an important modification that is critical for the activation of the Wnt signaling in odontoblasts and for production of the dentin matrix. PMID:22351753

  13. Zirconium and hafnium fractionation in differentiation of alkali carbonatite magmatic systems

    NASA Astrophysics Data System (ADS)

    Kogarko, L. N.

    2016-05-01

    Zirconium and hafnium are valuable strategic metals which are in high demand in industry. The Zr and Hf contents are elevated in the final products of magmatic differentiation of alkali carbonatite rocks in the Polar Siberia region (Guli Complex) and Ukraine (Chernigov Massif). Early pyroxene fractionation led to an increase in the Zr/Hf ratio in the evolution of the ultramafic-alkali magmatic system due to a higher distribution coefficient of Hf in pyroxene with respect to Zr. The Rayleigh equation was used to calculate a quantitative model of variation in the Zr/Hf ratio in the development of the Guli magmatic system. Alkali carbonatite rocks originated from rare element-rich mantle reservoirs, in particular, the metasomatized mantle. Carbonated mantle xenoliths are characterized by a high Zr/Hf ratio due to clinopyroxene development during metasomatic replacement of orthopyroxene by carbonate fluid melt.

  14. Sulfate reduction in freshwater wetland soils and the effects of sulfate and substrate loading

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, J.; Hsieh, Y.P.

    1998-07-01

    Elevated sulfate and organic C loadings in freshwater wetlands could stimulate dissimilatory sulfate reduction that oxidizes organic C, produces hydrogen sulfide and alkalinity, and sequesters trace metals. The authors determined the extent of sulfate reduction in two freshwater wetland soils, that is black gum (Nyssa biflona) swamp soils and titi (Cliftonia monophylla) swamp soils, in northern Florida. They also investigated the potential of sulfate reduction in the wetland soils by adding sulfate, organic substrate, and lime. Sulfate reduction was found to be an active process in both swamp soils without any amendment, where the pore water pH was as lowmore » as 3.6 and sulfate concentration was as low as 5 mg L{sup {minus}1}. Without amendment, 11 to 14% of organic C was oxidized through sulfate reduction in the swamp soils. Sulfate loading, liming, and substrate addition significantly increased sulfate reduction in the black gum swamp soil, but none of those treatments increase sulfate reduction in the titi swamp soil. The limiting factor for sulfate reduction in the titi swamp soil were likely texture and soil aggregate related properties. The results suggested that wastewater loading may increase sulfate reduction in some freshwater wetlands such as the black swamps while it has no stimulating effect on other wetlands such as the titi swamps.« less

  15. Experimental and first-principles studies on the elastic properties of α-hafnium metal under pressure

    DOE PAGES

    Qi, Xintong; Wang, Xuebing; Chen, Ting; ...

    2016-03-30

    Compressional and shear wave velocities of the α phase of hafnium have been measured up to 10.4 GPa at room temperature using ultrasonic interferometry in a multi-anvil apparatus. A finite strain equation of state analysis yielded K s0 = 110.4 (5) GPa, G 0 = 54.7(5) GPa,K s0' = 3.7 and G 0' = 0.6 for the elastic bulk and shear moduli and their pressure derivatives at ambient conditions. Complementary to the experimental data, the single crystal elastic constants, elastic anisotropy and the unit cell axial ratio c/a of α-hafnium at high pressures were investigated by Density Functional Theory (DFT)more » based first principles calculations. A c/a value of 1.605 is predicted for α-Hf at 40 GPa, which is in excellent agreement with previous experimental results. The low-pressure derivative of the shear modulus observed in our experimental data up to 10 GPa was found to originate from the elastic constant C44 which exhibits negligible pressure dependence within the current experimental pressure range. At higher pressures (>10 GPa), C 44 was predicted to soften and the shear wave velocity ν S trended to decrease with pressure, which can be interpreted as a precursor to the α-ω transition similar to that observed in other group IV elements (titanium and zirconium). Here, the acoustic velocities, bulk and shear moduli, and the acoustic Debye temperature (θ D = 240.1 K) determined from the current experiments were all compared well with those predicted by our theoretical DFT calculations.« less

  16. Stress-rupture strength and microstructural stability of tungsten-hafnium-carbon-wire reinforced superalloy composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Signorelli, R. A.

    1974-01-01

    Tungsten-hafnium-carbon - superalloy composites were found to be potentially useful for turbine blade applications on the basis of stress-rupture strength. The 100- and 1000-hr rupture strengths calculated for 70 vol. % fiber composites based on test data at 1090C (2000F) were 420 and 280 MN/m2 (61,000 and 41,000 psi, respectively). The investigation indicated that, with better quality fibers, composites having 100- and 1000-hr rupture strengths of 570 and 370 MN/m2 (82,000 and 54,000 psi, respectively), may be obtained. Metallographic studies indicated sufficient fiber-matrix compatibility for 1000 hr or more at 1090C (2000F).

  17. Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling.

    PubMed

    Ramachandra, Rashmi; Namburi, Ramesh B; Ortega-Martinez, Olga; Shi, Xiaofeng; Zaia, Joseph; Dupont, Sam T; Thorndyke, Michael C; Lindahl, Ulf; Spillmann, Dorothe

    2014-02-01

    Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates.

  18. 21 CFR 524.960 - Flumethasone, neomycin sulfate, and polymyxin B sulfate ophthalmic solutions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Flumethasone, neomycin sulfate, and polymyxin B sulfate ophthalmic solutions. 524.960 Section 524.960 Food and Drugs FOOD AND DRUG ADMINISTRATION... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.960 Flumethasone, neomycin sulfate, and polymyxin B sulfate...

  19. 21 CFR 524.960 - Flumethasone, neomycin sulfate, and polymyxin B sulfate ophthalmic solutions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Flumethasone, neomycin sulfate, and polymyxin B sulfate ophthalmic solutions. 524.960 Section 524.960 Food and Drugs FOOD AND DRUG ADMINISTRATION... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.960 Flumethasone, neomycin sulfate, and polymyxin B sulfate...

  20. Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

    PubMed

    Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

    2010-05-01

    Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

  1. Silicon doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) based FeFET: A material relation to device physics

    NASA Astrophysics Data System (ADS)

    Ali, T.; Polakowski, P.; Riedel, S.; Büttner, T.; Kämpfe, T.; Rudolph, M.; Pätzold, B.; Seidel, K.; Löhr, D.; Hoffmann, R.; Czernohorsky, M.; Kühnel, K.; Thrun, X.; Hanisch, N.; Steinke, P.; Calvo, J.; Müller, J.

    2018-05-01

    The recent discovery of ferroelectricity in thin film HfO2 materials renewed the interest in ferroelectric FET (FeFET) as an emerging nonvolatile memory providing a potential high speed and low power Flash alternative. Here, we report more insight into FeFET performance by integrating two types of ferroelectric (FE) materials and varying their properties. By varying the material type [HfO2 (HSO) versus hafnium zirconium oxide (HZO)], optimum content (Si doping/mixture ratio), and film thickness, a material relation to FeFET device physics is concluded. As for the material type, an improved FeFET performance is observed for HZO integration with memory window (MW) comparable to theoretical values. For different Si contents, the HSO based FeFET exhibited a MW trend with different stabilized phases. Similarly, the HZO FeFET shows MW dependence on the Hf:Zr mixture ratio. A maximized MW is obtained with cycle ratios of 16:1 (HfO2:Si) and 1:1 (Hf:Zr) as measured on HSO and HZO based FeFETs, respectively. The thickness variation shows a trend of increasing MW with the increased FE layer thickness confirming early theoretical predictions. The FeFET material aspects and stack physics are discussed with insight into the interplay factors, while optimum FE material parameters are outlined in relation to performance.

  2. Automotive sulfate emission data.

    PubMed Central

    Somers, J H

    1975-01-01

    This paper discusses automotive sulfate emission results obtained by the Office of Mobile Source Air Pollution Control of EPA, General Motors, Ford, Chrysler, and Esso. This work has been directed towards obtaining sulfate emission factors for cars with and without catalyst. While the EPA and Chrysler investigations have found significant sulfate formation in noncatalyst cars, GM, Ford, and Esso have found only trace levels from noncatalyst cars. All of these investigators agree that much higher quantities of sulfate are emitted from catalyst cars. The work done to date shows pelleted catalysts to have much lower sulfate emissions over the low speed-EPA Federal Test Procedures than monolith catalysts. This is probably due to temporary storage of sulfates on the catalyst due to chemical interaction with the alumina pellets. The sulfate compounds are, to a large degree, emitted later under higher speed conditions which result in higher catalyst temperatures which decompose the alumina salt. Future work will be directed towards further elucidation of this storage mechanism as well as determining in detail how factors such as air injection rate and catalyst location affect sulfate emissions. PMID:50932

  3. Atomic layer deposition of hafnium oxide: A detailed reaction mechanism from first principles

    NASA Astrophysics Data System (ADS)

    Widjaja, Yuniarto; Musgrave, Charles B.

    2002-08-01

    Atomic layer deposition (ALD) of hafnium oxide (HfO2) using HfCl4 and H2O as precursors is studied using density functional theory. The mechanism consists of two deposition half-reactions: (1) HfCl4 with Hf-OH sites, and (2) H2O with Hf-Cl sites. Both half-reactions exhibit stable intermediates with energies lower than those of the final products. We show that increasing the temperature reduces the stability of the complex. However, increasing temperature also increases the dissociation free-energy barrier, which in turn results in increased desorption of adsorbed precursors. Both half-reactions are qualitatively similar to the corresponding reactions of ZrO2 ALD using ZrCl4 and H2O.

  4. Intrinsic Defect Ferromagnetism: The case of Hafnium Oxide

    NASA Astrophysics Data System (ADS)

    Das Pemmaraju, Chaitanya

    2005-03-01

    In view of the recent experimental reports of intrinsic ferromagnetism in Hafnium Oxide (HfO2) thin film systems ootnotetextM. Venkatesan, C. B. Fitzgerald, J. M. D. Coey Nature 430, 630 (2004) Brief Communications, we carried out first principles investigations to look for magnetic structure in HfO2 possibly brought about by the presence of small concentrations of intrinsic point defects. Ab initio electronic structure calculations using Density Functional Theory (DFT) show that isolated cation vacancy sites in HfO2 lead to the formation of high spin defect states which couple ferromagnetically to each other. Interestingly, these high spin states are observed in the low symmetry monoclinic and tetragonal phases while the highly symmetric cubic flourite phase exhibits a non-magnetic ground state. Detailed studies of the electronic structure of cation vacancies in the three crystalline phases of Hafnia show that symmetry leading to orbitally degenerate defect levels is not a pre-requsite for ferromagnetism and that the interplay between Kinetic, Coulomb and Exchange energy together with favourable coupling to the Crystalline environment can lead to high spin ferromagnetic ground states even in extreme low symmetry systems like monoclinic HfO2. These findings open up a much wider class of systems to the possibility of intrinsic defect ferromagnetism.

  5. Work functions of hafnium nitride thin films as emitter material for field emitter arrays

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gotoh, Yasuhito, E-mail: gotoh.yasuhito.5w@kyoto-u.ac.jp; Fujiwara, Sho; Tsuji, Hiroshi

    The work functions of hafnium nitride thin films prepared by radio-frequency magnetron sputtering were investigated in vacuum, before and after surface cleaning processes, with a view of improving the properties of as-fabricated field emitter arrays comprising hafnium nitride emitters. The measurement of the work function was first performed for the as-deposited films and then for films subjected to surface cleaning process, either thermal treatment or ion bombardment. Thermal treatment at a maximum temperature of 300 °C reduced the work function by 0.7 eV. Once the film was heated, the work function maintained the reduced value, even after cooling to room temperature. Amore » little change in the work function was observed for the second and third thermal treatments. The ion bombardment was conducted by exposing the sample to a thin plasma for different sample bias conditions and processing times. When the sample was biased at −10 V, the work function decreased by 0.6 eV. The work function reduction became saturated in the early stage of the ion bombardment. When the sample was biased at −50 V, the work function exhibited different behaviors, that is, first it decreased rapidly and then increased in response to the increase in processing time. The lowest attainable work function was found to be 4.00 eV. It should be noted that none of the work function values reported in this paper were obtained using surfaces that were demonstrated to be free from oxygen contamination. The present results suggest that the current–voltage characteristics of a field emitter array can be improved by a factor of 25–50 by the examined postprocesses.« less

  6. The interfacial orientation relationship of oxide nanoparticles in a hafnium-containing oxide dispersion-strengthened austenitic stainless steel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miao, Yinbin, E-mail: miao2@illinois.edu; Mo, Kun; Cui, Bai

    2015-03-15

    This work reports comprehensive investigations on the orientation relationship of the oxide nanoparticles in a hafnium-containing austenitic oxide dispersion-strengthened 316 stainless steel. The phases of the oxide nanoparticles were determined by a combination of scanning transmission electron microscopy–electron dispersive X-ray spectroscopy, atom probe tomography and synchrotron X-ray diffraction to be complex Y–Ti–Hf–O compounds with similar crystal structures, including bixbyite Y{sub 2}O{sub 3}, fluorite Y{sub 2}O{sub 3}–HfO{sub 2} solid solution and pyrochlore (or fluorite) Y{sub 2}(Ti,Hf){sub 2−x}O{sub 7−x}. High resolution transmission electron microscopy was used to characterize the particle–matrix interfaces. Two different coherency relationships along with one axis-parallel relation between themore » oxide nanoparticles and the steel matrix were found. The size of the nanoparticles significantly influences the orientation relationship. The results provide insight into the relationship of these nanoparticles with the matrix, which has implications for interpreting material properties as well as responses to radiation. - Highlights: • The oxide nanoparticles in a hafnium-containing austenitic ODS were characterized. • The nanoparticles are Y–Hf–Ti–O enriched phases according to APT and STEM–EDS. • Two coherency and an axis-parallel orientation relationships were found by HR-TEM. • Particle size has a prominent effect on the orientation relationship (OR). • Formation mechanism of the oxide nanoparticles was discussed based on the ORs.« less

  7. Novel Alkylsulfatases Required for Biodegradation of the Branched Primary Alkyl Sulfate Surfactant 2-Butyloctyl Sulfate

    PubMed Central

    Ellis, Andrew J.; Hales, Stephen G.; Ur-Rehman, Naheed G. A.; White, Graham F.

    2002-01-01

    Recent reports show that contrary to common perception, branched alkyl sulfate surfactants are readily biodegradable in standard biodegradability tests. We report here the isolation of bacteria capable of biodegrading 2-butyloctyl sulfate and the identification of novel enzymes that initiate the process. Enrichment culturing from activated sewage sludge yielded several strains capable of growth on 2-butyloctyl sulfate. Of these, two were selected for further study and identified as members of the genus Pseudomonas. Strain AE-A was able to utilize either sodium dodecyl sulfate (SDS) or 2-butyloctyl sulfate as a carbon and energy source for growth, but strain AE-D utilized only the latter. Depending on growth conditions, strain AE-A produced up to three alkylsulfatases, as shown by polyacrylamide gel electrophoresis zymography. Growth on either SDS or 2-butyloctyl sulfate or in nutrient broth produced an apparently constitutive, nonspecific primary alkylsulfatase, AP1, weakly active on SDS and on 2-butyloctyl sulfate. Growth on 2-butyloctyl sulfate produced a second enzyme, AP2, active on 2-butyloctyl sulfate but not on SDS, and growth on SDS produced a third enzyme, AP3, active on SDS but not on 2-butyloctyl sulfate. In contrast, strain AE-D, when grown on 2-butyloctyl sulfate (no growth on SDS), produced a single enzyme, DP1, active on 2-butyloctyl sulfate but not on SDS. DP1 was not produced in broth cultures. DP1 was induced when residual 2-butyloctyl sulfate was present in the growth medium, but the enzyme disappeared when the substrate was exhausted. Gas chromatographic analysis of products of incubating 2-butyloctyl sulfate with DP1 in gels revealed the formation of 2-butyloctanol, showing the enzyme to be a true sulfatase. In contrast, Pseudomonas sp. strain C12B, well known for its ability to degrade linear SDS, was unable to grow on 2-butyloctyl sulfate, and its alkylsulfatases responsible for initiating the degradation of SDS by releasing the parent

  8. [Regulation of sulfates, hydrogen sulfide and heavy metals in technogenic reservoirs by sulfate-reducing bacteria].

    PubMed

    Hudz', S P; Peretiatko, T B; Moroz, O M; Hnatush, S O; Klym, I R

    2011-01-01

    Sulfate-reducing bacteria Desulfovibrio desulfuricans Ya-11 in the presence of sulfates and organic compounds in the medium reduce sulfates to hydrogen sulfide (dissimilatory sulfate reduction). Heavy metals in concentration over 2 mM inhibit this process. Pb2+, Zn2+, Ni2+, Co2+, Fe2+ and Cd2+ ions in concentration 1-1.5 mM display insignificant inhibiting effect on sulfate reduction process, and metals precipitate in the form of sulfides. At concentrations of heavy metals 2-3 mM one can observe a decrease of sulfates reduction intensity, and a percent of metals binding does not exceed 72%. Obtained results give reason to confirm, that sulfate-reducing bacteria play an important role in regulation of the level of sulfates, hydrogen sulfide and heavy metals in reservoirs and they may be used for purification of water environment from these compounds.

  9. Tailoring the index of refraction of nanocrystalline hafnium oxide thin films

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vargas, Mirella; Murphy, N. R.; Ramana, C. V., E-mail: rvchintalapalle@utep.edu

    2014-03-10

    Hafnium oxide (HfO{sub 2}) films were grown by sputter-deposition by varying the growth temperature (T{sub s} = 25–700 °C). HfO{sub 2} films grown at T{sub s} < 200 °C were amorphous, while those grown at T{sub s} ≥ 200 °C were monoclinic, nanocrystalline with (1{sup ¯}11) texturing. X-ray reflectivity (XRR) analyses indicate that the film-density (ρ) increases with increasing T{sub s}. The index of refraction (n) profiles derived from spectroscopic ellipsometry analyses follow the Cauchy dispersion relation. Lorentz-Lorenz analysis (n{sub (λ)} = 550 nm) and optical-model adopted agree well with the XRR data/analyses. A direct T{sub s}-ρ-n relationship suggests that tailoring the optical quality is possible by tuning T{sub s} and themore » microstructure of HfO{sub 2} films.« less

  10. The role of sulfate in aerobic granular sludge process for emerging sulfate-laden wastewater treatment.

    PubMed

    Xue, Weiqi; Hao, Tianwei; Mackey, Hamish R; Li, Xiling; Chan, Richard C; Chen, Guanghao

    2017-11-01

    Sulfate-rich wastewaters pose a major threat to mainstream wastewater treatment due to the unpreventable production of sulfide and associated shift in functional bacteria. Aerobic granular sludge could mitigate these challenges in view of its high tolerance and resilience against changes in various environmental conditions. This study aims to confirm the feasibility of aerobic granular sludge in the treatment of sulfate containing wastewater, investigate the impact of sulfate on nutrient removal and granulation, and reveal metabolic relationships in the above processes. Experiments were conducted using five sequencing batch reactors with different sulfate concentrations operated under alternating anoxic/aerobic condition. Results showed that effect of sulfate on chemical oxygen demand (COD) removal is negligible, while phosphate removal was enhanced from 12% to 87% with an increase in sulfate from 0 to 200 mg/L. However, a long acclimatization of the biomass (more than 70 days) is needed at a sulfate concentration of 500 mg/L and a total deterioration of phosphate removal at 1000 mg/L. Batch tests revealed that sulfide promoted volatile fatty acids (VFAs) uptake, producing more energy for phosphate uptake when sulfate concentrations were beneath 200 mg/L. However, sulfide detoxification became energy dominating, leaving insufficient energy for Polyhydroxyalkanoate (PHA) synthesis and phosphate uptake when sulfate content was further increased. Granulation accelerated with increasing sulfate levels by enhanced production of N-Acyl homoserine lactones (AHLs), a kind of quorum sensing (QS) auto-inducer, using S-Adenosyl Methionine (SAM) as primer. The current study demonstrates interactions among sulfate metabolism, nutrients removal and granulation, and confirms the feasibility of using the aerobic granular sludge process for sulfate-laden wastewaters treatment with low to medium sulfate content. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Modeling Reduction of Uranium U(VI) under Variable Sulfate Concentrations by Sulfate-Reducing Bacteria

    PubMed Central

    Spear, John R.; Figueroa, Linda A.; Honeyman, Bruce D.

    2000-01-01

    The kinetics for the reduction of sulfate alone and for concurrent uranium [U(VI)] and sulfate reduction, by mixed and pure cultures of sulfate-reducing bacteria (SRB) at 21 ± 3°C were studied. The mixed culture contained the SRB Desulfovibrio vulgaris along with a Clostridium sp. determined via 16S ribosomal DNA analysis. The pure culture was Desulfovibrio desulfuricans (ATCC 7757). A zero-order model best fit the data for the reduction of sulfate from 0.1 to 10 mM. A lag time occurred below cell concentrations of 0.1 mg (dry weight) of cells/ml. For the mixed culture, average values for the maximum specific reaction rate, Vmax, ranged from 2.4 ± 0.2 μmol of sulfate/mg (dry weight) of SRB · h−1) at 0.25 mM sulfate to 5.0 ± 1.1 μmol of sulfate/mg (dry weight) of SRB · h−1 at 10 mM sulfate (average cell concentration, 0.52 mg [dry weight]/ml). For the pure culture, Vmax was 1.6 ± 0.2 μmol of sulfate/mg (dry weight) of SRB · h−1 at 1 mM sulfate (0.29 mg [dry weight] of cells/ml). When both electron acceptors were present, sulfate reduction remained zero order for both cultures, while uranium reduction was first order, with rate constants of 0.071 ± 0.003 mg (dry weight) of cells/ml · min−1 for the mixed culture and 0.137 ± 0.016 mg (dry weight) of cells/ml · min−1 (U0 = 1 mM) for the D. desulfuricans culture. Both cultures exhibited a faster rate of uranium reduction in the presence of sulfate and no lag time until the onset of U reduction in contrast to U alone. This kinetics information can be used to design an SRB-dominated biotreatment scheme for the removal of U(VI) from an aqueous source. PMID:10966381

  12. Additionally sulfated xylomannan sulfates from Scinaia hatei and their antiviral activities.

    PubMed

    Ray, Sayani; Pujol, Carlos A; Damonte, Elsa B; Ray, Bimalendu

    2015-10-20

    Herpes simplex viruses (HSVs) display affinity for cell-surface heparan sulfate proteoglycans with biological relevance in virus entry. This study demonstrates the potential of chemically engineered sulfated xylomannans from Scinaia hatei as antiHSV drug candidate. Particularly, a dimethylformamide -SO3/pyridine based procedure has been employed for the generation of anionic polysaccharides. This one-step procedure has the power of providing a spectrum of xylomannans with varying molecular masses (<12-74kDa), sulfate content (1-50%) and glycosyl composition. Especially, the sulfated xylomannans S1F1 and S2F1 possessed altered activity against HSV-1 and HSV-2 compared to the parental compound (F1) and that too in the absence of drug-induced cytotoxicity. Regarding methodological facet, the directive decoration of hydroxyl functionality with sulfate group plus changes in the molecular mass and sugar composition during isolation by the used reagent opens a door for the production of new molecular entity with altered biological activity from other natural sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Sulfation degree not origin of chondroitin sulfate derivatives modulates keratinocyte response.

    PubMed

    Corsuto, Luisana; Rother, Sandra; Koehler, Linda; Bedini, Emiliano; Moeller, Stephanie; Schnabelrauch, Matthias; Hintze, Vera; Schiraldi, Chiara; Scharnweber, Dieter

    2018-07-01

    Chondroitin sulfate (CS) sulfation-dependently binds transforming growth factor-β1 (TGF-β1) and chronic wounds often accompany with epidermal hyperproliferation due to downregulated TGF-β signaling. However, the impact of CS on keratinocytes is unknown. Especially biotechnological-chemical strategies are promising to replace animal-derived CS. Thus, this study aims to evaluate the effects of CS derivatives on the interaction with vascular endothelial growth factor-A (VEGF-A) and on keratinocyte response. Over-sulfated CS (sCS3) interacts stronger with VEGF-A than CS. Furthermore, collagen coatings with CS variants are prepared by in vitro fibrillogenesis. Stability analyses demonstrate that collagen is firmly integrated, while the fibril diameters decrease with increasing sulfation degree. CS variants sulfation-dependently decelerate keratinocyte (HaCaT) migration and proliferation in a scratch assay. HaCaT cultured on sCS3-containing coatings produced increased amounts of solute active TGF-β1 which could be translated into biomaterials able to decrease epidermal hyperproliferation in chronic wounds. Overall, semi-synthetic and natural CS yield to comparable responses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Mixtures of Sulfates in Melas Chasma

    NASA Image and Video Library

    2017-09-04

    In this image from NASA's Mars Reconnaissance Orbiter, layering within the light-toned sulfate deposit is the result of different states of hydration. Some of the layers have sulfates with little water (known as monohydrated sulfates) whereas other layers have higher amounts of water (called polyhydrated sulfates). The different amounts of water within the sulfates may reflect changes in the water chemistry during deposition of the sulfates, or may have occurred after the sulfates were laid down when heat or pressure forced the water out of some layers, causing a decrease in the hydration state. Many locations on Mars have sulfates, which are sedimentary rocks formed in water. Within Valles Marineris, the large canyon system that cuts across the planet, there are big and thick sequences of sulfates. The CRISM instrument on MRO is crucial for telling scientists which type of sulfate is associated with each layer, because each hydration state will produce a spectrum with absorptions at specific wavelengths depending upon the amount of water contained within the sulfate. https://photojournal.jpl.nasa.gov/catalog/PIA21935

  15. High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms.

    PubMed

    Dillon, Jesse G; Fishbain, Susan; Miller, Scott R; Bebout, Brad M; Habicht, Kirsten S; Webb, Samuel M; Stahl, David A

    2007-08-01

    The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population. Reduced activity at greater depths was correlated with novel populations of sulfate-reducing microorganisms, unrelated to characterized species, and most likely due to both sulfate and carbon limitation.

  16. Hafnium-doped hydroxyapatite nanoparticles with ionizing radiation for lung cancer treatment.

    PubMed

    Chen, Min-Hua; Hanagata, Nobutaka; Ikoma, Toshiyuki; Huang, Jian-Yuan; Li, Keng-Yuan; Lin, Chun-Pin; Lin, Feng-Huei

    2016-06-01

    Recently, photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. However, the optical approach of PDT is limited by tissue penetration depth of visible light. In this study, we propose that a ROS-enhanced nanoparticle, hafnium-doped hydroxyapatite (Hf:HAp), which is a material to yield large quantities of ROS inside the cells when the nanoparticles are bombarded with high penetrating power of ionizing radiation. Hf:HAp nanoparticles are generated by wet chemical precipitation with total doping concentration of 15mol% Hf(4+) relative to Ca(2+) in HAp host material. The results show that the HAp particles could be successfully doped with Hf ions, resulted in the formation of nano-sized rod-like shape and with pH-dependent solubility. The impact of ionizing radiation on Hf:HAp nanoparticles is assessed by using in-vitro and in-vivo model using A549 cell line. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) results reveal that after being exposed to gamma rays, Hf:HAp could significantly lead to the formation of ROS in cells. Both cell viability (WST-1) and cytotoxicity (LDH) assay show the consistent results that A549 lung cancer cell lines are damaged with changes in the cells' ROS level. The in-vivo studies further demonstrate that the tumor growth is inhibited owing to the cells apoptosis when Hf:HAp nanoparticles are bombarded with ionizing radiation. This finding offer a new therapeutic method of interacting with ionizing radiation and demonstrate the potential of Hf:HAp nanoparticles in tumor treatment, such as being used in a palliative treatment after lung surgical procedure. Photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. Unfortunately, the approach of PDT is usually limited to the treatment of systemic disease and deeper tumor, due to the limited tissue penetration depth of visible

  17. 21 CFR 184.1315 - Ferrous sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferrous sulfate. 184.1315 Section 184.1315 Food... GRAS § 184.1315 Ferrous sulfate. (a) Ferrous sulfate heptahydrate (iron (II) sulfate heptahydrate, Fe... pale, bluish-green crystals or granules. Progressive heating of ferrous sulfate heptahydrate produces...

  18. High Rates of Sulfate Reduction in a Low-Sulfate Hot Spring Microbial Mat Are Driven by a Low Level of Diversity of Sulfate-Respiring Microorganisms▿

    PubMed Central

    Dillon, Jesse G.; Fishbain, Susan; Miller, Scott R.; Bebout, Brad M.; Habicht, Kirsten S.; Webb, Samuel M.; Stahl, David A.

    2007-01-01

    The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population. Reduced activity at greater depths was correlated with novel populations of sulfate-reducing microorganisms, unrelated to characterized species, and most likely due to both sulfate and carbon limitation. PMID:17575000

  19. Chondroitin sulfate/dermatan sulfate sulfatases from mammals and bacteria.

    PubMed

    Wang, Shumin; Sugahara, Kazuyuki; Li, Fuchuan

    2016-12-01

    Sulfatases that specifically catalyze the hydrolysis of the sulfate groups on chondroitin sulfate (CS)/dermatan sulfate (DS) poly- and oligosaccharides belong to the formylglycine-dependent family of sulfatases and have been widely found in various mammalian and bacterial organisms. However, only a few types of CS/DS sulfatase have been identified so far. Recently, several novel CS/DS sulfatases have been cloned and characterized. Advanced studies have provided significant insight into the biological function and mechanism of action of CS/DS sulfatases. Moreover, further studies will provide powerful tools for structural and functional studies of CS/DS as well as related applications. This article reviews the recent progress in CS/DS sulfatase research and is expected to initiate further research in this field.

  20. Novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.

    1994-01-01

    Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H2 or organic electron donors oxidized S0 to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum. Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S0 with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S0 + 3 MnO2 + 4H+ ???SO42- + 3Mn(II) + 2H2O. None of the organisms evaluated could be grown with S0 as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S0 in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S0 as follows: 4S0 + 4H2O???SO42- + 3HS- + 5 H+. Growth of Desulfobulbus propionicus with S0 as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S0 oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(IV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S0.

  1. Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates

    USGS Publications Warehouse

    Wang, A.; Freeman, J.J.; Jolliff, B.L.; Chou, I.-Ming

    2006-01-01

    The martian orbital and landed surface missions, OMEGA on Mar Express and the two Mars Explorations Rovers, respectively, have yielded evidence pointing to the presence of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium sulfates, as well as the hydration states of other Ca- and Fe- sulfates, will be crucial in future landed missions on Mars in order to advance our knowledge of the hydrologic history of Mars as well as the potential for hosting life on Mars. Raman spectroscopy is a technique well-suited for landed missions on the martian surface. In this paper, we report a systematic study of the Raman spectra of the hydrates of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11 distinct hydrates of magnesium sulfates, crystalline and non-crystalline. The unique Raman spectral features along with the general tendency of the shift of the position of the sulfate ??1 band towards higher wavenumbers with a decrease in the degree of hydration allow in situ identification of these hydrated magnesium sulfates from the raw Raman spectra of mixtures. Using these Raman spectral features, we have started the study of the stability field of hydrated magnesium sulfates and the pathways of their transformations at various temperature and relative humidity conditions. In particular we report on the Raman spectrum of an amorphous hydrate of magnesium sulfate (MgSO4??2H2O) that may have specific relevance for the martian surface. ?? 2006 Elsevier Inc. All rights reserved.

  2. Using Terrestrial Sulfate Efflorescences as an Analogue of Hydrated Sulfate Formation in Valles Marineris on Mars

    NASA Astrophysics Data System (ADS)

    Smith, P. C.; Szynkiewicz, A.

    2015-12-01

    Hydrated sulfate minerals provide conclusive evidence that a hydrologic cycle was once active on the surface of Mars. Two classes of hydrated sulfate minerals have been detected by robotic instruments on Mars: monohydrated sulfate minerals comprised of kieserite and gypsum, and various polyhydrated sulfates with Fe-Ca-Na-Mg-rich compositions. These minerals are found in various locations on Mars, including large surface exposures in valley settings of Valles Marineris. However, the sulfate sources and formation mechanisms of these minerals are not yet well understood.Recently, it has been suggested that the sulfate minerals in Valles Marineris might have formed in a manner similar to sulfate efflorescences found in dry environments on Earth. In this study, we use sulfate effloresences from the Rio Puerco Watershed, New Mexico as a terrestrial analogue to assess major factors that might have led to deposition of sulfate minerals in Valles Marineris. In different seasons indicative of dry and wet conditions, we collected field photographs and sediment samples for chemical and stable isotopic analyses (sulfur content, δ34S) to determine major sources of sulfate ions for efflorescences and to assess how the seasonal changes in surface/groundwater activity affect their formation. Preliminary sulfur isotope results suggest that oxidation of bedrock sulfides (0.01-0.05 wt. S %) is a major source of sulfate ion for efflorescences formation because their δ34S varied in negative range (-28 to -20‰) similar to sulfides (average -32‰). Using field photographs collected in Oct 2006, Feb and Nov 2012, May 2013, Mar and Oct 2014, we infer that the highest surface accumulation of sulfate efflorescences in the studied analog site was observed after summer monsoon seasons when more water was available for surface and subsurface transport of solutes from chemical weathering. Conversely, spring snow melt led to enhanced dissolution of sulfate efflorescences.

  3. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ferric sulfate. 184.1307 Section 184.1307 Food and... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by...

  4. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric sulfate. 184.1307 Section 184.1307 Food and... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by...

  5. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ferric sulfate. 184.1307 Section 184.1307 Food and... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by...

  6. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferric sulfate. 184.1307 Section 184.1307 Food and....1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or...

  7. 21 CFR 184.1307 - Ferric sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ferric sulfate. 184.1307 Section 184.1307 Food and... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by...

  8. Electron-beam-evaporated thin films of hafnium dioxide for fabricating electronic devices

    DOE PAGES

    Xiao, Zhigang; Kisslinger, Kim

    2015-06-17

    Thin films of hafnium dioxide (HfO 2) are widely used as the gate oxide in fabricating integrated circuits because of their high dielectric constants. In this paper, the authors report the growth of thin films of HfO 2 using e-beam evaporation, and the fabrication of complementary metal-oxide semiconductor (CMOS) integrated circuits using this HfO 2 thin film as the gate oxide. The authors analyzed the thin films using high-resolution transmission electron microscopy and electron diffraction, thereby demonstrating that the e-beam-evaporation-grown HfO 2 film has a polycrystalline structure and forms an excellent interface with silicon. Accordingly, we fabricated 31-stage CMOS ringmore » oscillator to test the quality of the HfO 2 thin film as the gate oxide, and obtained excellent rail-to-rail oscillation waveforms from it, denoting that the HfO 2 thin film functioned very well as the gate oxide.« less

  9. Acetate Production from Oil under Sulfate-Reducing Conditions in Bioreactors Injected with Sulfate and Nitrate

    PubMed Central

    Callbeck, Cameron M.; Agrawal, Akhil

    2013-01-01

    Oil production by water injection can cause souring in which sulfate in the injection water is reduced to sulfide by resident sulfate-reducing bacteria (SRB). Sulfate (2 mM) in medium injected at a rate of 1 pore volume per day into upflow bioreactors containing residual heavy oil from the Medicine Hat Glauconitic C field was nearly completely reduced to sulfide, and this was associated with the generation of 3 to 4 mM acetate. Inclusion of 4 mM nitrate inhibited souring for 60 days, after which complete sulfate reduction and associated acetate production were once again observed. Sulfate reduction was permanently inhibited when 100 mM nitrate was injected by the nitrite formed under these conditions. Pulsed injection of 4 or 100 mM nitrate inhibited sulfate reduction temporarily. Sulfate reduction resumed once nitrate injection was stopped and was associated with the production of acetate in all cases. The stoichiometry of acetate formation (3 to 4 mM formed per 2 mM sulfate reduced) is consistent with a mechanism in which oil alkanes and water are metabolized to acetate and hydrogen by fermentative and syntrophic bacteria (K. Zengler et al., Nature 401:266–269, 1999), with the hydrogen being used by SRB to reduce sulfate to sulfide. In support of this model, microbial community analyses by pyrosequencing indicated SRB of the genus Desulfovibrio, which use hydrogen but not acetate as an electron donor for sulfate reduction, to be a major community component. The model explains the high concentrations of acetate that are sometimes found in waters produced from water-injected oil fields. PMID:23770914

  10. Acetate production from oil under sulfate-reducing conditions in bioreactors injected with sulfate and nitrate.

    PubMed

    Callbeck, Cameron M; Agrawal, Akhil; Voordouw, Gerrit

    2013-08-01

    Oil production by water injection can cause souring in which sulfate in the injection water is reduced to sulfide by resident sulfate-reducing bacteria (SRB). Sulfate (2 mM) in medium injected at a rate of 1 pore volume per day into upflow bioreactors containing residual heavy oil from the Medicine Hat Glauconitic C field was nearly completely reduced to sulfide, and this was associated with the generation of 3 to 4 mM acetate. Inclusion of 4 mM nitrate inhibited souring for 60 days, after which complete sulfate reduction and associated acetate production were once again observed. Sulfate reduction was permanently inhibited when 100 mM nitrate was injected by the nitrite formed under these conditions. Pulsed injection of 4 or 100 mM nitrate inhibited sulfate reduction temporarily. Sulfate reduction resumed once nitrate injection was stopped and was associated with the production of acetate in all cases. The stoichiometry of acetate formation (3 to 4 mM formed per 2 mM sulfate reduced) is consistent with a mechanism in which oil alkanes and water are metabolized to acetate and hydrogen by fermentative and syntrophic bacteria (K. Zengler et al., Nature 401:266-269, 1999), with the hydrogen being used by SRB to reduce sulfate to sulfide. In support of this model, microbial community analyses by pyrosequencing indicated SRB of the genus Desulfovibrio, which use hydrogen but not acetate as an electron donor for sulfate reduction, to be a major community component. The model explains the high concentrations of acetate that are sometimes found in waters produced from water-injected oil fields.

  11. Acute Exacerbations of COPD Are Associated With Increased Expression of Heparan Sulfate and Chondroitin Sulfate in BAL.

    PubMed

    Papakonstantinou, Eleni; Klagas, Ioannis; Roth, Michael; Tamm, Michael; Stolz, Daiana

    2016-03-01

    Acute exacerbations of COPD (AECOPDs) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. We investigated whether AECOPDs are associated with differential expression of glycosaminoglycans in BAL in a cohort of 97 patients with COPD. Patients with COPD with either stable disease (n = 53) or AECOPD (n = 44) and undergoing diagnostic bronchoscopy were matched for demographics and lung function parameters. Levels of heparan sulfate, chondroitin sulfate, dermatan sulfate, and matrix metalloproteinases (MMPs) in BAL were measured by enzyme-linked immunosorbent assay. Heparan sulfate and chondroitin sulfate were significantly increased in BAL of patients during exacerbations. Levels of heparan sulfate were higher in the BAL of patients with microbial infections. Chondroitin sulfate was negatively correlated with FEV1 % predicted but not with diffusing capacity of lung for carbon monoxide % predicted, indicating that chondroitin sulfate is associated with airway remodeling, leading to obstruction rather than to emphysema. Furthermore, heparan sulfate and chondroitin sulfate were significantly correlated with MMP-9, MMP-2, and MMP-12 in BAL, indicating that they were cleaved from their respective proteoglycans by MMPs and subsequently washed out in BAL. During AECOPD, there is increased expression of heparan sulfate and chondroitin sulfate in BAL. These molecules are significantly correlated with MMPs in BAL, indicating that they may be associated with airway remodeling and may lead to lung function decline during exacerbations of COPD. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  12. Quantitative analysis of glycosaminoglycans, chondroitin/dermatan sulfate, hyaluronic acid, heparan sulfate, and keratan sulfate by liquid chromatography-electrospray ionization-tandem mass spectrometry.

    PubMed

    Osago, Harumi; Shibata, Tomoko; Hara, Nobumasa; Kuwata, Suguru; Kono, Michihaya; Uchio, Yuji; Tsuchiya, Mikako

    2014-12-15

    We developed a method using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with a selected reaction monitoring (SRM) mode for simultaneous quantitative analysis of glycosaminoglycans (GAGs). Using one-shot analysis with our MS/MS method, we demonstrated the simultaneous quantification of a total of 23 variously sulfated disaccharides of four GAG classes (8 chondroitin/dermatan sulfates, 1 hyaluronic acid, 12 heparan sulfates, and 2 keratan sulfates) with a sensitivity of less than 0.5 pmol within 20 min. We showed the differences in the composition of GAG classes and the sulfation patterns between porcine articular cartilage and yellow ligament. In addition to the internal disaccharides described above, some saccharides derived from the nonreducing terminal were detected simultaneously. The simultaneous quantification of both internal and nonreducing terminal saccharides could be useful to estimate the chain length of GAGs. This method would help to establish comprehensive "GAGomic" analysis of biological tissues. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The Importance of Sulfate Adenylyl Transferase in S and O Fractionation by Sulfate Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Smith, D. A.; Johnston, D. T.; Bradley, A. S.

    2016-12-01

    Microbial sulfate reduction (MSR) is critical to the oxidation of organic matter in modern and ancient oceans, and plays an important role in regulating the redox state of the Earth's surface. The sulfur and oxygen isotopic composition of seawater sulfate and of sulfate minerals reflect the biogeochemical processes that cycle sulfur, of which MSR is among the most important. MSR is a multi-enzymatic reaction network that partitions the isotopes of sulfur and oxygen as a consequence of both the flux of sulfate through this biochemical network and the fractionation imposed by each individual enzyme. MSR affects the δ18O of residual, extracellular sulfate mainly by the equilibration of the MSR intermediate sulfite with extracellular water (Antler et al., 2013 GCA, Wankel et al., 2013 Geobiol). A series of oxidative and exchange reactions catalyzed by APS reductase (APSr), sulfate adenylyl transferase (Sat), and sulfate transporters promote the conversion of water-equilibrated intracellular sulfite to extracellular sulfate. The flux of sulfoxy anions via these proteins will be, at least in part, dependent on the activity of these enzymes. To test this, we examined sulfur and oxygen isotope fractionation in genetically engineered mutants of the sulfate reducing bacterium Desulfovibrio vulgaris Hildenborough (DvH). In these mutants, the activity of Sat has been artificially increased by perturbing the (i) transcriptional repressor Rex and (ii) its binding site upstream of the gene encoding Sat (Christensen et al., 2015 J. Bacteriol). It was predicted that this would minimize the back reaction of Sat, enhance the intracellular pool of APS, and minimize the equilibration between sulfite and adenosine monophosphate (AMP). Both mutants, along with the wild type DvH were grown in batch culture made with water enriched in 18O. Samples were collected throughout batch growth, and we report the evolution of the S and O isotopic composition of sulfate, and of the S isotopic

  14. Effect of nitrogen on tensile properties and structures of T-111 (tantalum, 8 percent tungsten, 2 percent hafnium) tubing

    NASA Technical Reports Server (NTRS)

    Buzzard, R. J.; Metroka, R. R.

    1973-01-01

    The effect of controlled nitrogen additions was evaluated on the mechanical properties of T-111 (Ta-8W-2Hf) fuel pin cladding material proposed for use in a lithium-cooled nuclear reactor concept. Additions of 80 to 1125 ppm nitrogen resulted in increased strengthening of T-111 tubular section test specimens at temperatures of 25 to 1200 C. Homogeneous distributions of up to 500 ppm nitrogen did not seriously decrease tensile ductility. Both single and two-phase microstructures, with hafnium nitride as the second phase, were evaluated in this study.

  15. Aerobic sulfate reduction in microbial mats

    NASA Technical Reports Server (NTRS)

    Canfield, Donald E.; Des Marais, David J.

    1991-01-01

    Measurements of bacterial sulfate reduction and dissolved oxygen (O2) in hypersaline bacterial mats from Baja California, Mexico, revealed that sulfate reduction occurred consistently within the well-oxygenated photosynthetic zone of the mats. This evidence that dissimilatory sulfate reduction can occur in the presence of O2 challenges the conventional view that sulfate reduction is a strictly anaerobic process. At constant temperature, the rates of sulfate reduction in oxygenated mats during daytime were similar to rates in anoxic mats at night: thus, during a 24-hour cycle, variations in light and O2 have little effect on rates of sulfate reduction in these mats.

  16. 21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 043264; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

  17. 21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

  18. 21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

  19. 21 CFR 524.155 - Bacitracin zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment. 524.155 Section 524.155 Food and... zinc-polymyxin B sulfate-neomycin sulfate-hydrocortisone or hydrocortisone acetate ophthalmic ointment... hydrocortisone. (2) To 025463; each gram of ointment contains 400 units of bacitracin zinc, 10,000 units of...

  20. Pyroelectric response in crystalline hafnium zirconium oxide (Hf 1- x Zr x O 2 ) thin films

    DOE PAGES

    Smith, S. W.; Kitahara, A. R.; Rodriguez, M. A.; ...

    2017-02-13

    Pyroelectric coefficients were measured for 20 nm thick crystalline hafnium zirconium oxide (Hf 1-xZr xO 2) thin films across a composition range of 0 ≤ x ≤ 1. Pyroelectric currents were collected near room temperature under zero applied bias and a sinusoidal oscillating temperature profile to separate the influence of non-pyroelectric currents. The pyroelectric coefficient was observed to correlate with zirconium content, increased orthorhombic/tetragonal phase content, and maximum polarization response. The largest measured absolute value was 48 μCm -2K -1 for a composition with x = 0.64, while no pyroelectric response was measured for compositions which displayed no remanent polarizationmore » (x = 0, 0.91, 1).« less

  1. Constraining Δ33S signatures of Archean seawater sulfate with carbonate-associated sulfate

    NASA Astrophysics Data System (ADS)

    Peng, Y.; Bao, H.; Bekker, A.; Hofmann, A.

    2017-12-01

    Non-mass dependent sulfur isotope deviation of S-bearing phases in Archean sedimentary strata, and expressed as Δ33S, has a consistent pattern, i.e., sulfide (pyrite) predominantly bear positive Δ33S values, while Paleoarchean sulfate (barite) has negative Δ33S values. This pattern was later corroborated by observations of negative Δ33S values in Archean volcanogenic massive sulfide deposits and negative Δ33S values in early diagenetic nodular pyrite with a wide range of δ34S values, which is thought to be due to microbial sulfate reduction. These signatures have provided a set of initial conditions for a mechanistic interpretation at physical chemistry level. Unlike the younger geological times when large bodies of seawater evaporite deposits are common, to expand seawater sulfate records, carbonate-associated sulfate (CAS) was utilized as a proxy for ancient seawater sulfate. CAS extracted from the Archean carbonates carries positive Δ33S values. However, CAS could be derived from pyrite oxidation following exposure to modern oxidizing conditions and/or during laboratory extraction procedures. It is, therefore, important for us understanding context of the overall early earth atmospheric condition to empirically confirm whether Archean seawater sulfate was generally characterized by negative Δ33S signatures. Combined δ18O, Δ17O, δ34S, and Δ33S analyses of sequentially extracted water-leachable sulfate (WLS) and acid-leachable sulfate (ALS = CAS) and δ34S and Δ33S analyses of pyrite can help to identify the source of extracted sulfate. We studied drill-core samples of Archean carbonates from the 2.55 Ga Malmani and Campell Rand supgroups, South Africa. Our preliminary results show that 1) neither WLS nor ALS were extracted from samples with extremely low pyrite contents (less than 0.05 wt.%); 2) extractable WLS and ALS is present in samples with relatively high pyrite contents (more than 1 wt.%), and that δ34S and Δ33S values of WLS, ALS, and

  2. Transport of steroid 3-sulfates and steroid 17-sulfates by the sodium-dependent organic anion transporter SOAT (SLC10A6).

    PubMed

    Grosser, Gary; Bennien, Josefine; Sánchez-Guijo, Alberto; Bakhaus, Katharina; Döring, Barbara; Hartmann, Michaela; Wudy, Stefan A; Geyer, Joachim

    2018-05-01

    The sodium-dependent organic anion transporter SOAT/Soat shows highly specific transport activity for sulfated steroids. SOAT substrates identified so far include dehydroepiandrosterone sulfate, 16α-hydroxydehydroepiandrosterone sulfate, estrone-3-sulfate, pregnenolone sulfate, 17β-estradiol-3-sulfate, and androstenediol sulfate. Apart from these compounds, many other sulfated steroids occur in mammals. Therefore, we aimed to expand the substrate spectrum of SOAT and analyzed the SOAT-mediated transport of eight different sulfated steroids by combining in vitro transport experiments in SOAT-transfected HEK293 cells with LC-MS/MS analytics of cell lysates. In addition, we aimed to better understand the structural requirements for SOAT substrates and so selected structural pairs varying only at specific positions: 3α/3β-sulfate, 17α/17β-sulfate, mono-sulfate/di-sulfate, and 17α-hydroxylation. We found significant and sodium-dependent SOAT-mediated transport of 17α-hydroxypregnenolone sulfate, 17β-estradiol-17-sulfate, androsterone sulfate, epiandrosterone sulfate, testosterone sulfate, epitestosterone sulfate, and 5α-dihydrotestosterone sulfate. However, 17β-estradiol-3,17-disulfate was not transported by SOAT. SOAT substrates from the group of sulfated steroids are characterized by a planar and lipophilic steroid backbone in trans-trans-trans conformation of the rings and a negatively charged mono-sulfate group at positions 3' or 17' with flexibility for α- or β- orientation. Furthermore, 5α-reduction, 16α-hydroxylation, and 17α-hydroxylation are acceptable for SOAT substrate recognition, whereas addition of a second negatively charged sulfate group seems to abolish substrate binding to SOAT, and so 17β-estradiol-3,17-disulfate is not transported by SOAT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. 21 CFR 558.364 - Neomycin sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and... in Animal Feeds § 558.364 Neomycin sulfate. (a) Approvals. Type A medicated article: 325 grams per.... (c) [Reserved] (d) Conditions of use. Neomycin sulfate is used as follows: Neomycin Sulfate...

  4. 21 CFR 558.364 - Neomycin sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and... in Animal Feeds § 558.364 Neomycin sulfate. (a) Approvals. Type A medicated article: 325 grams per.... (c) [Reserved] (d) Conditions of use. Neomycin sulfate is used as follows: Neomycin Sulfate...

  5. 21 CFR 558.364 - Neomycin sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and... in Animal Feeds § 558.364 Neomycin sulfate. (a) Approvals. Type A medicated article: 325 grams per.... (c) [Reserved] (d) Conditions of use. Neomycin sulfate is used as follows: Neomycin Sulfate...

  6. 21 CFR 558.364 - Neomycin sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and... in Animal Feeds § 558.364 Neomycin sulfate. (a) Approvals. Type A medicated article: 325 grams per.... (c) [Reserved] (d) Conditions of use. Neomycin sulfate is used as follows: Neomycin Sulfate...

  7. 21 CFR 558.364 - Neomycin sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and... in Animal Feeds § 558.364 Neomycin sulfate. (a) Approvals. Type A medicated article: 325 grams per.... (c) [Reserved] (d) Conditions of use. Neomycin sulfate is used as follows: Neomycin Sulfate...

  8. INTRACELLULAR SYNTHESIS OF CHONDROITIN SULFATE

    PubMed Central

    Dziewiatkowski, Dominic D.

    1962-01-01

    In autoradiograms of slices of costal cartilage, incubated for 4 hours in a salt solution containing S35-sulfate and then washed extensively and dehydrated, about 85 per cent of the radioactivity was assignable to the chondrocytes. From alkaline extracts of similarly prepared slices of cartilage, 64 to 83 per cent of the total sulfur-35 in the slices was isolated as chondroitin sulfate by chromatography on an anion-exchange resin. In view of the estimate that only about 15 per cent of the radioactivity was in the matrix, the isolation of 64 to 83 per cent of the total sulfur-35 as chondroitin sulfate is a strong argument that the chondrocytes are the loci in which chondroitin sulfate(s) is synthesized. PMID:13888910

  9. Synthesis of N-oleyl O-sulfate chitosan from methyl oleate with O-sulfate chitosan as edible film material

    NASA Astrophysics Data System (ADS)

    Daniel; Sihaloho, O.; Saleh, C.; Magdaleni, A. R.

    2018-04-01

    The research on the synthesis of N-oleyl O-sulfate chitosan through sulfonation reaction on chitosan with ammonium sulfate and followed by amidation reaction using methyl oleate has been done. In this study, chitosan was chemically modified into N-oleyl O-sulfatechitosan as an edible film making material. N-oleyl O-sulfate chitosan was synthesized by reaction between methyl oleate and O-sulfate chitosan. Wherein the depleted chitosan of O-sulfate chitosan into O-sulfate chitosan was obtained by reaction of sulfonation between ammonium sulfate and chitosan aldimine. While chitosan aldimine was obtained through reaction between chitosan with acetaldehyde. The structure of N-oleyl O-sulfate chitosan was characterized by FT-IR analysis which showed vibration uptake of C-H sp3 group, S=O group, and carbonyl group C=O of the ester. The resulting of N-oleyl O-sulfate chitosan yielded a percentage of 93.52%. Hydrophilic-Lipophilic Balance (HLB) test results gave a value of 6.68. In the toxicity test results of N-oleyl O-sulfate chitosan obtained LC50 value of 3738.4732 ppm. In WVTR (Water Vapor Transmission Rate) test results for chitosan film was 407.625 gram/m2/24 hours and N-oleylO-sulfate chitosan film was 201.125 gram/m2/24 hours.

  10. 21 CFR 184.1315 - Ferrous sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ferrous sulfate. 184.1315 Section 184.1315 Food... Specific Substances Affirmed as GRAS § 184.1315 Ferrous sulfate. (a) Ferrous sulfate heptahydrate (iron (II) sulfate heptahydrate, FeSO4·7H2O, CAS Reg. No. 7782-63-0) is prepared by the action of sulfuric acid on...

  11. 21 CFR 184.1461 - Manganese sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Manganese sulfate. 184.1461 Section 184.1461 Food... GRAS § 184.1461 Manganese sulfate. (a) Manganese sulfate (MnSO4·H2O, CAS Reg. No. 7785-0987-097) is a... of pyrolusite (MnO2) ore with solid ferrous sulfate and coal, followed by leaching and...

  12. 21 CFR 184.1315 - Ferrous sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ferrous sulfate. 184.1315 Section 184.1315 Food... Specific Substances Affirmed as GRAS § 184.1315 Ferrous sulfate. (a) Ferrous sulfate heptahydrate (iron (II) sulfate heptahydrate, FeSO4·7H2O, CAS Reg. No. 7782-63-0) is prepared by the action of sulfuric acid on...

  13. 21 CFR 184.1461 - Manganese sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Manganese sulfate. 184.1461 Section 184.1461 Food... Specific Substances Affirmed as GRAS § 184.1461 Manganese sulfate. (a) Manganese sulfate (MnSO4·H2O, CAS... dioxide in sulfuric acid, and the roasting of pyrolusite (MnO2) ore with solid ferrous sulfate and coal...

  14. 21 CFR 184.1461 - Manganese sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Manganese sulfate. 184.1461 Section 184.1461 Food... Specific Substances Affirmed as GRAS § 184.1461 Manganese sulfate. (a) Manganese sulfate (MnSO4·H2O, CAS... dioxide in sulfuric acid, and the roasting of pyrolusite (MnO2) ore with solid ferrous sulfate and coal...

  15. 21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment. 524.154 Section 524.154 Food and Drugs FOOD AND DRUG ADMINISTRATION... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.154 Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B...

  16. 21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment. 524.154 Section 524.154 Food and Drugs FOOD AND DRUG ADMINISTRATION... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.154 Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B...

  17. 21 CFR 172.822 - Sodium lauryl sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium lauryl sulfate. 172.822 Section 172.822... Sodium lauryl sulfate. The food additive sodium lauryl sulfate may be safely used in food in accordance... of sodium alkyl sulfates consisting chiefly of sodium lauryl sulfate [CH2(CH2)10CH2OSO2Na]. (2) It...

  18. Methods of producing sulfate salts of cations from heteroatomic compounds and dialkyl sulfates and uses thereof

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2015-09-29

    Methods of preparing sulfate salts of heteroatomic compounds using dialkyl sulfates as a primary reactant are disclosed. Also disclosed are methods of making ionic liquids from the sulfate salts of the heteroatomic compound, and electrochemical cells comprising the ionic liquids.

  19. Purification and sequence characterization of chondroitin sulfate and dermatan sulfate from fishes.

    PubMed

    Lin, Na; Mo, Xiaoli; Yang, Yang; Zhang, Hong

    2017-04-01

    Chondroitin sulfate (CS) and dermatan sulfate (DS) were extracted and purified from skins or bones of salmon (Salmo salar), snakehead (Channa argus), monkfish (Lophius litulon) and skipjack tuna (Katsuwonus pelamis). Size, structural sequences and sulfate groups of oligosaccharides in the purified CS and DS could be characterized and identified using high performance liquid chromatography (HPLC) combined with Orbitrap mass spectrometry. CS and DS chain structure varies depending on origin, but motif structure appears consistent. Structures of CS and DS oligosaccharides with different size and sulfate groups were compared between fishes and other animals, and results showed that some minor differences of special structures could be identified by hydrophilic interaction chromatography-liquid chromatography-fourier transform-mass/mass spectrometry (HILIC-LC-FT-MS/MS). For example, data showed that salmon and skipjack CS had a higher percentage content of high-level sulfated oligosaccharides than that porcine CS. In addition, structural information of different origins of CS and DS was analyzed by principal component analysis (PCA) and results showed that CS and DS samples could be differentiated according to their molecular conformation and oligosaccharide fragments information. Understanding CS and DS structure derived from different origins may lead to the production of CS or DS with unique disaccharides or oligosaccharides sequence composition and biological functions.

  20. Sulfates on Mars: Indicators of Aqueous Processes

    NASA Technical Reports Server (NTRS)

    Bishop, Janice L.; Lane, Melissa D.; Dyar, M. Darby; Brown, Adrian J.

    2006-01-01

    Recent analyses by MER instruments at Meridiani Planum and Gusev crater and the OMEGA instrument on Mars Express have provided detailed information about the presence of sulfates on Mars [1,2,3]. We are evaluating these recent data in an integrated multi-disciplinary study of visible-near-infrared, mid-IR and Mossbauer spectra of several sulfate minerals and sulfate-rich analog sites. Our analyses suggest that hydrated iron sulfates may account for features observed in Mossbauer and mid-IR spectra of Martian soils [4]. The sulfate minerals kieserite, gypsum and other hydrated sulfates have been identified in OMEGA spectra in the layered terrains in Valles Marineris and Terra Meridiani [2]. These recent discoveries emphasize the importance of studying sulfate minerals as tracers of aqueous processes. The sulfate-rich rock outcrops observed in Meridiani Planum may have formed in an acidic environment similar to acid rock drainage environments on Earth [5]. Because microorganisms typically are involved in the oxidation of sulfides to sulfates in terrestrial sites, sulfate-rich rock outcrops on Mars may be a good location to search for evidence of past life on that planet. Whether or not life evolved on Mars, following the trail of sulfate minerals will lead to a better understanding of aqueous processes and chemical weathering.

  1. Modulating inhibitors of transthyretin fibrillogenesis via sulfation: polychlorinated biphenyl sulfates as models.

    PubMed

    Grimm, Fabian A; Lehmler, Hans-Joachim; He, Xianran; Robertson, Larry W; Duffel, Michael W

    2015-02-25

    Small molecules that bind with high affinity to thyroxine (T4) binding sites on transthyretin (TTR) kinetically stabilize the protein's tetrameric structure, thereby efficiently decreasing the rate of tetramer dissociation in TTR related amyloidoses. Current research efforts aim to optimize the amyloid inhibiting properties of known inhibitors, such as derivatives of biphenyls, dibenzofurans and benzooxazoles, by chemical modification. In order to test the hypothesis that sulfate group substituents can improve the efficiencies of such inhibitors, we evaluated the potential of six polychlorinated biphenyl sulfates to inhibit TTR amyloid fibril formation in vitro. In addition, we determined their binding orientations and molecular interactions within the T4 binding site by molecular docking simulations. Utilizing this combined experimental and computational approach, we demonstrated that sulfation significantly improves the amyloid inhibiting properties as compared to both parent and hydroxylated PCBs. Importantly, several PCB sulfates were of equal or higher potency than some of the most effective previously described inhibitors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Tribo-electrochemical characterization of hafnium multilayer systems deposited on nitride/vanadium nitride AISI 4140 steel

    NASA Astrophysics Data System (ADS)

    Mora, M.; Vera, E.; Aperador, W.

    2016-02-01

    In this work is presented the synergistic behaviour among corrosion/wear (tribocorrosion) of the multilayer coatings hafnium nitride/vanadium nitride [HfN/VN]n. The multilayers were deposited on AISI 4140 steel using the technique of physical vapor deposition PVD magnetron sputtering, the tests were performed using a pin-on-disk tribometer, which has an adapted potentiostat galvanostat with three-electrode electrochemical cell. Tribocorrosive parameters such as: Friction coefficient between the coating and the counter body (100 Cr6 steel ball); Polarization resistance by means of electrochemical impedance spectroscopy technique and corrosion rate by polarization curves were determined. It was observed an increase in the polarization resistance, a decrease in the corrosion rate and a low coefficient of friction in comparison with the substrate, due to an increase on the number of bilayers.

  3. Cellular mechanisms of renal adaptation of sodium dependent sulfate cotransport to altered dietary sulfate in rats.

    PubMed

    Sagawa, K; DuBois, D C; Almon, R R; Murer, H; Morris, M E

    1998-12-01

    The renal transport and fractional reabsorption of inorganic sulfate is altered under conditions of sulfate deficiency or excess. The objective of this study was to examine the cellular mechanisms of adaptation of renal sodium/sulfate cotransport after varying dietary intakes of a sulfur containing amino acid, methionine. Female Lewis rats were divided into four groups and fed diets containing various concentrations of methionine (0, 0.3, 0.82 and 2.46%) for 8 days. Urinary excretion rates and renal clearance of sulfate were significantly decreased in the animals fed a 0% methionine diet or a 0.3% methionine diet, and significantly increased in the animals fed a 2.46% methionine diet when evaluated on days 4 and 7. Serum sulfate concentrations were unchanged by diet treatment in all animals. The fractional reabsorption of sulfate was significantly increased in the animals fed the 0% methionine diet and the 0.3% methionine diets, and decreased in the animals fed the 2.46% methionine diet. Increased mRNA and protein levels for the sodium/sulfate transporter (NaSi-1) were found in the kidney cortex following treatment with the 0 and 0.3% methionine diet groups. Sulfate homeostasis by renal reabsorption is maintained by an up-regulation of steady state levels of NaSi-1 mRNA and protein when the diet is low in methionine.

  4. Synthesis of High Symmetry Phase of Hafnium Dioxide Thin Films and Nickel Ferrite's Effect on Microstructure in Composite Heterostructure

    NASA Astrophysics Data System (ADS)

    Straka, Weston J.

    Hafnium dioxide has attracted a great deal of attention recently due to its potential use in two different electronic applications: CMOS and FeRAM. In CMOS, the usefulness of hafnia comes in due to its high dielectric constant and compatibility with current IC processing parameters. For FeRAM, hafnia's recent discovery to exhibit ferroelectricity in an orthorhombic phase makes this material attractive for replacement of the ferroelectric material in FeRAM. This study shows the feasibility of depositing thin films of hafnium oxide via chemical solution deposition for integration into these devices. The processing parameters necessary to produce this phase show how non-equilibrium processing plays a role in its synthesis. The temperature necessary to achieve the high symmetry phase was at 725 °C for 3 minutes on sapphire, silicon, and coated silicon substrates. The thermal conductivity of each was viewed as the property that allowed the hafnia formation. The dielectric constant of the hafnia films were between 30 and 32 with low dissipation factors and up to 47 with a poor dissipation factor all at 1 kHz. The formation of this phase was shown to be thickness independent with the high symmetry phase existing up to 300 nm film thickness. Interfacing the hafnia film with nickel ferrite was also studied to identify the possibility of using this composite for non-destructive reading of FeRAM. The magnetic properties showed an unchanged nickel ferrite film but the interface between the two was poor leading to the conclusion that more work must be done to successfully integrate these two films.

  5. Divergent Synthesis of Chondroitin Sulfate Disaccharides and Identification of Sulfate Motifs that Inhibit Triple Negative Breast Cancer

    NASA Astrophysics Data System (ADS)

    Wei Poh, Zhong; Heng Gan, Chin; Lee, Eric J.; Guo, Suxian; Yip, George W.; Lam, Yulin

    2015-09-01

    Glycosaminoglycans (GAGs) regulate many important physiological processes. A pertinent issue to address is whether GAGs encode important functional information via introduction of position specific sulfate groups in the GAG structure. However, procurement of pure, homogenous GAG motifs to probe the “sulfation code” is a challenging task due to isolation difficulty and structural complexity. To this end, we devised a versatile synthetic strategy to obtain all the 16 theoretically possible sulfation patterns in the chondroitin sulfate (CS) repeating unit; these include rare but potentially important sulfated motifs which have not been isolated earlier. Biological evaluation indicated that CS sulfation patterns had differing effects for different breast cancer cell types, and the greatest inhibitory effect was observed for the most aggressive, triple negative breast cancer cell line MDA-MB-231.

  6. Hafnium Films and Magnetic Shielding for TIME, A mm-Wavelength Spectrometer Array

    NASA Astrophysics Data System (ADS)

    Hunacek, J.; Bock, J.; Bradford, C. M.; Butler, V.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Frez, C.; Hailey-Dunsheath, S.; Hoscheit, B.; Kim, D. W.; Li, C.-T.; Marrone, D.; Moncelsi, L.; Shirokoff, E.; Steinbach, B.; Sun, G.; Trumper, I.; Turner, A.; Uzgil, B.; Weber, A.; Zemcov, M.

    2018-04-01

    TIME is a mm-wavelength grating spectrometer array that will map fluctuations of the 157.7-μm emission line of singly ionized carbon ([CII]) during the epoch of reionization (redshift z ˜ 5-9). Sixty transition-edge sensor (TES) bolometers populate the output arc of each of the 32 spectrometers, for a total of 1920 detectors. Each bolometer consists of gold absorber on a ˜ 3 × 3 mm silicon nitride micro-mesh suspended near the corners by 1 × 1 × 500 μm silicon nitride legs targeting a photon-noise-dominated NEP ˜ 1 × 10^{-17} W/√{Hz} . Hafnium films are explored as a lower-T_c alternative to Ti (500 mK) for TIME TESs, allowing thicker support legs for improved yield. Hf T_c is shown to vary between 250 and 450 mK when varying the resident Ar pressure during deposition. Magnetic shielding designs and simulations are presented for the TIME first-stage SQUIDs. Total axial field suppression is predicted to be 5 × 10^7.

  7. 21 CFR 172.822 - Sodium lauryl sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium lauryl sulfate. 172.822 Section 172.822... CONSUMPTION Multipurpose Additives § 172.822 Sodium lauryl sulfate. The food additive sodium lauryl sulfate... following specifications: (1) It is a mixture of sodium alkyl sulfates consisting chiefly of sodium lauryl...

  8. Comparison of magnesium sulfate and sodium sulfate for removal of water from pesticide extracts of foods.

    PubMed

    Schenck, Frank J; Callery, Patrick; Gannett, Peter M; Daft, Jonathan R; Lehotay, Steven J

    2002-01-01

    Water-miscible solvents, such as acetone and acetonitrile, effectively extract both polar and nonpolar pesticide residues from nonfatty foods. The addition of sodium chloride to the resulting acetonitrile-water or acetone-water extract (salting out) results in the separation of the water from the organic solvent. However, the organic solvent layer (pesticide extract) still contains some residual water, which can adversely affect separation procedures that follow, such as solid-phase extraction and/or gas chromatography. Drying agents, such as sodium sulfate or magnesium sulfate, are used to remove the water from the organic extracts. In the present study, we used nuclear magnetic resonance spectroscopy to study the composition of the phases resulting from salting out and to compare the effectiveness of sodium sulfate and magnesium sulfate as drying agents. The study showed that considerable amounts of water remained in the organic phase after phase separation. Sodium sulfate was a relatively ineffective drying agent, removing little or no residual water from the organic solvent. Magnesium sulfate proved to be a much more effective drying agent.

  9. Tracing the history of submarine hydrothermal inputs and the significance of hydrothermal hafnium for the seawater budget - A combined Pb-Hf-Nd isotope approach

    USGS Publications Warehouse

    van de Flierdt, T.; Frank, M.; Halliday, A.N.; Hein, J.R.; Hattendorf, B.; Gunther, D.; Kubik, P.W.

    2004-01-01

    Secular variations in the Pb isotopic composition of a mixed hydrogenous-hydrothermal ferromanganese crust from the Bauer Basin in the eastern Equatorial Pacific provide clear evidence for changes in hydrothermal contributions during the past 7 Myr. The nearby Galapagos Rise spreading center provided a strong hydrothermal flux prior to 6.5 Ma. After 6.5 Ma, the Pb became stepwise more radiogenic and more similar to Equatorial Pacific seawater, reflecting the westward shift of spreading to the presently active East Pacific Rise (EPR). A second, previously unrecognized enhanced hydrothermal period occurred between 4.4 and 2.9 Ma, which reflects either off-axis hydrothermal activity in the Bauer Basin or a late-stage pulse of hydrothermal Pb from the then active, but waning Galapagos Rise spreading center. Hafnium isotope time-series of the same mixed hydrogenous-hydrothermal crust show invariant values over the past 7 Myr. Hafnium isotope ratios, as well as Nd isotope ratios obtained for this crust, are identical to that of hydrogenous Equatorial Pacific deep water crusts and clearly indicate that hydrothermal Hf, similar to Nd, does not travel far from submarine vents. Therefore, we suggest that hydrothermal Hf fluxes do not contribute significantly to the global marine Hf budget. ?? 2004 Elsevier B.V. All rights reserved.

  10. Monoalkyl sulfates as alkylating agents in water, alkylsulfatase rate enhancements, and the “energy-rich” nature of sulfate half-esters

    PubMed Central

    Wolfenden, Richard; Yuan, Yang

    2007-01-01

    Alkyl sulfate monoesters are involved in cell signaling and structure. Alkyl sulfates are also present in many commercial detergents. Here, we show that monomethyl sulfate acts as an efficient alkylating agent in water, reacting spontaneously with oxygen nucleophiles >100-fold more rapidly than do alkylsulfonium ions, the usual methyl donors in living organisms. These reactions of methyl sulfate, which are much more rapid than its hydrolysis, are insensitive to the nature of the attacking nucleophile, with a Brønsted βnuc value of −0.01. Experiments at elevated temperatures indicate a rate constant of 2 × 10−11 s−1 for the uncatalyzed hydrolysis of methyl sulfate at 25°C (t1/2 = 1,100 y), corresponding to a rate enhancement of ≈1011-fold by a human alkylsulfatase. Equilibria of formation of methyl sulfate from methanol and sodium hydrogen sulfate indicate a group transfer potential (ΔG′pH7) of −8.9 kcal/mol for sulfate ester hydrolysis. The magnitude of that value, involving release of the strong acid HSO4−, helps to explain the need for harnessing the free energy of hydrolysis of two ATP molecules in activating sulfate for the biosynthesis of sulfate monoesters. The “energy-rich” nature of monoalkyl sulfate esters, coupled with their marked resistance to hydrolysis, renders them capable of acting as sulfating or alkylating agents under relatively mild conditions. These findings raise the possibility that, under appropriate circumstances, alkyl groups may undergo transfer from alkyl sulfate monoesters to biological target molecules. PMID:17182738

  11. The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

    USGS Publications Warehouse

    Chou, I-Ming; Seal, Robert R.; Wang, Alian

    2013-01-01

    Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO"4-H"2O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous

  12. The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

    USGS Publications Warehouse

    Chou, I-Ming; Seal, Robert R.; Wang, Alian

    2013-01-01

    Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1 MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO4-H2O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous sulfates

  13. Sulfate resistance of high calcium fly ash concrete

    NASA Astrophysics Data System (ADS)

    Dhole, Rajaram

    Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime

  14. Effects of chlorate on the sulfation process of Trypanosoma cruzi glycoconjugates. Implication of parasite sulfates in cellular invasion.

    PubMed

    Ferrero, Maximiliano R; Soprano, Luciana L; Acosta, Diana M; García, Gabriela A; Esteva, Mónica I; Couto, Alicia S; Duschak, Vilma G

    2014-09-01

    Sulfation, a post-translational modification which plays a key role in various biological processes, is inhibited by competition with chlorate. In Trypanosoma cruzi, the agent of Chagas' disease, sulfated structures have been described as part of glycolipids and we have reported sulfated high-mannose type oligosaccharides in the C-T domain of the cruzipain (Cz) glycoprotein. However, sulfation pathways have not been described yet in this parasite. Herein, we studied the effect of chlorate treatment on T. cruzi with the aim to gain some knowledge about sulfation metabolism and the role of sulfated molecules in this parasite. In chlorate-treated epimastigotes, immunoblotting with anti-sulfates enriched Cz IgGs (AS-enriched IgGs) showed Cz undersulfation. Accordingly, a Cz mobility shift toward higher isoelectric points was observed in 2D-PAGE probed with anti-Cz antibodies. Ultrastructural membrane abnormalities and a significant decrease of dark lipid reservosomes were shown by electron microscopy and a significant decrease in sulfatide levels was confirmed by TLC/UV-MALDI-TOF-MS analysis. Altogether, these results suggest T. cruzi sulfation occurs via PAPS. Sulfated epitopes in trypomastigote and amastigote forms were evidenced using AS-enriched IgGs by immunoblotting. Their presence on trypomastigotes surface was demonstrated by flow cytometry and IF with Cz/dCz specific antibodies. Interestingly, the percentage of infected cardiac HL-1 cells decreased 40% when using chlorate-treated trypomastigotes, suggesting sulfates are involved in the invasion process. The same effect was observed when cells were pre-incubated with dCz, dC-T or an anti-high mannose receptor (HMR) antibody, suggesting Cz sulfates and HMR are also involved in the infection process by T. cruzi. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Modulating Inhibitors of Transthyretin Fibrillogenesis via Sulfation: Polychlorinated Biphenyl Sulfates as Models1

    PubMed Central

    Grimm, Fabian A.; Lehmler, Hans-Joachim; He, Xianran; Robertson, Larry W.; Duffel, Michael W.

    2015-01-01

    Small molecules that bind with high affinity to thyroxine (T4) binding sites on transthyretin (TTR) kinetically stabilize the protein’s tetrameric structure, thereby efficiently decreasing the rate of tetramer dissociation in TTR related amyloidoses. Current research efforts aim to optimize the amyloid inhibiting properties of known inhibitors, such as derivatives of biphenyls, dibenzofurans and benzooxazoles, by chemical modification. In order to test the hypothesis that sulfate group substituents can improve the efficiencies of such inhibitors, we evaluated the potential of six polychlorinated biphenyl sulfates to inhibit TTR amyloid fibril formation in vitro. In addition, we determined their binding orientations and molecular interactions within the T4 binding site by molecular docking simulations. Utilizing this combined experimental and computational approach, we demonstrated that sulfation significantly improves the amyloid inhibiting properties as compared to both parent and hydroxylated PCBs. Importantly, several PCB sulfates were of equal or higher potency than some of the most effective previously described inhibitors. PMID:25595224

  16. Synthesis, physicochemical characterization and biological evaluation of chitosan sulfate as heparan sulfate mimics.

    PubMed

    Doncel-Pérez, Ernesto; Aranaz, Inmaculada; Bastida, Agatha; Revuelta, Julia; Camacho, Celia; Acosta, Niuris; Garrido, Leoncio; Civera, Concepción; García-Junceda, Eduardo; Heras, Angeles; Fernández-Mayoralas, Alfonso

    2018-07-01

    Despite the relevant biological functions of heparan sulfate (HS) glycosaminoglycans, their limited availability and the chemical heterogeneity from natural sources hamper their use for biomedical applications. Chitosan sulfates (ChS) exhibit structural similarity to HSs and may mimic their biological functions. We prepared a variety of ChS with different degree of sulfation to evaluate their ability to mimic HS in protein binding and to promote neural cell division and differentiation. The structure of the products was characterized using various spectroscopic and analytical methods. The study of their interaction with different growth factors showed that ChS bound to the proteins similarly or even better than heparin. In cell cultures, a transition effect on cell number was observed as a function of ChS concentration. Differences in promoting the expression of the differentiation markers were also found depending on the degree of sulfation and modification in the chitosan. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Inter vs. intraglycosidic acetal linkages control sulfation pattern in semi-synthetic chondroitin sulfate.

    PubMed

    Laezza, Antonio; De Castro, Cristina; Parrilli, Michelangelo; Bedini, Emiliano

    2014-11-04

    Microbial-sourced unsulfated chondroitin could be converted into chondroitin sulfate (CS) polysaccharide by a multi-step strategy relying upon benzylidenation and acetylation reactions as key-steps for its regioselective protection. By conducting the two reactions one- or two-pots, CSs with different sulfation patterns could be obtained at the end of the semi-synthesis. In particular, a CS polysaccharide possessing sulfate groups randomly distributed between positions 4 and 6 of N-acetyl-galactosamine (GalNAc) units could be obtained through the two-pots route, whereas the one-pot pathway allowed an additional sulfation at position 3 of some glucuronic acid (GlcA) units. This difference was ascribed to the stabilization of a labile interglycosidic benzylidene acetal involving positions O-3 and O-6 of some GlcA and GalNAc, respectively, when the benzylidene-acetylation reactions were conducted in a one-pot fashion. Isolation and characterization of a polysaccharide intermediate showing interglycosidic acetal moieties was accomplished. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 21 CFR 582.1643 - Potassium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

  19. 21 CFR 582.1643 - Potassium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

  20. 21 CFR 582.1643 - Potassium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

  1. 21 CFR 582.1643 - Potassium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

  2. 21 CFR 582.1643 - Potassium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

  3. Tracing sources of streamwater sulfate during snowmelt using S and O isotope ratios of sulfate and 35S activity

    USGS Publications Warehouse

    Shanley, J.B.; Mayer, B.; Mitchell, M.J.; Michel, R.L.; Bailey, S.W.; Kendall, C.

    2005-01-01

    The biogeochemical cycling of sulfur (S) was studied during the 2000 snowmelt at Sleepers River Research Watershed in northeastern Vermont, USA using a hydrochemical and multi-isotope approach. The snowpack and 10 streams of varying size and land use were sampled for analysis of anions, dissolved organic carbon (DOC), 35S activity, and ?? 34S and ?? 18O values of sulfate. At one of the streams, ?? 18O values of water also were measured. Apportionment of sulfur derived from atmospheric and mineral sources based on their distinct ?? 34S values was possible for 7 of the 10 streams. Although mineral S generally dominated, atmospheric-derived S contributions exceeded 50% in several of the streams at peak snowmelt and averaged 41% overall. However, most of this atmospheric sulfur was not from the melting snowpack; the direct contribution of atmospheric sulfate to streamwater sulfate was constrained by 35S mass balance to a maximum of 7%. Rather, the main source of atmospheric sulfur in streamwater was atmospheric sulfate deposited months to years earlier that had microbially cycled through the soil organic sulfur pool. This atmospheric/pedospheric sulfate (pedogenic sulfate formed from atmospheric sulfate) source is revealed by ?? 18O values of streamwater sulfate that remained constant and significantly lower than those of atmospheric sulfate throughout the melt period, as well as streamwater 35S ages of hundreds of days. Our results indicate that the response of streamwater sulfate to changes in atmospheric deposition will be mediated by sulfate retention in the soil. ?? Springer 2005.

  4. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  5. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance...

  6. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  7. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance...

  8. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  9. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance...

  10. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  11. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  12. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  13. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  14. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance...

  15. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  16. 21 CFR 182.8997 - Zinc sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Zinc sulfate. 182.8997 Section 182.8997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of...

  17. Purification of Keratan Sulfate-endogalactosidase and its action on keratan sulfates of different origin.

    PubMed

    Nakazawa, K; Suzuki, S

    1975-02-10

    A glycosidase which attacks corneal keratan sulfate was purified from extracts of Pseudomonas sp. IFO-13309. When corneal keratan sulfate was degraded by the purified enzyme, Sephadex G-50 chromatography indicated the presence of a number of oligosaccharides differing in size and sulfate content. The characterization of two major fractions of the oligosaccharides indicated that the point of enzyme attack is limited to the endo-beta-D-galactoside bonds in which nonsulfated D-galactose residues participate. The enzyme, unlike ordinary exo-beta-D-galactosidases, did not catalyze the hydrolysis of phenyl beta-D-galactoside. Moreover, beta-D-galactosyl-(1 leads to 3)-2-acetamido-2-deoxy-beta-D-glucosyl-(1 leads to 3)-beta-D-galactosyl-(1 leads to 4)-D-glucose ("lacto-N-tetraose") was completely refractory to the action of this enzyme, suggesting that a structure of the type, X-(1 leads to 3)-beta-D-galactosyl-(1 leads to 4)-Y, is not the only specificity-determining factor, i.e. neighboring sugars, X and Y, or even larger portions of substrate molecule must have an important effect. Compared with corneal keratan sulfate, keratan sulfates from human nucleus pulposus and shark cartilage were attacked at lower rates with a resultant production of oligosaccharides of relatively large size. The result is in agreement with the view that considerable variations exist in the structure of keratan sulfates of different origin, and further suggests that the enzyme may serve as a useful reagent in studying these variations.

  18. Sulfation pattern of fucose branches affects the anti-hyperlipidemic activities of fucosylated chondroitin sulfate.

    PubMed

    Wu, Nian; Zhang, Yu; Ye, Xingqian; Hu, Yaqin; Ding, Tian; Chen, Shiguo

    2016-08-20

    Fucosylated chondroitin sulfates (fCSs) are glycosaminoglycans extracted from sea cucumbers, consisting of chondroitin sulfate E (CSE) backbones and sulfated fucose branches. The biological properties of fCSs could be affected by the sulfation pattern of their fucose branches. In the present study, two fCSs were isolated from sea cucumbers Isostichopus badionotus (fCS-Ib) and Pearsonothuria graeffei (fCS-Pg). Their monosaccharide compositions of glucuronic acid (GlcA), N-acetylgalactosamine (GalNAc), fucose (Fuc) and sulfate were at similar molar ratio with 1.0/0.7/0.9/3.1 for fCS-Ib and 1.0/0.8/1.5/2.6 for fCS-Pg. The two fCSs have different sulfation patterns on their fucose branches, fCS-Pg with 3,4-O-disulfation while fCS-Ib with 2,4-O-disulfation. Their antihyperlipidemic effects were compared using a high-fat high-fructose diet (HFFD)-fed C57BL/6J mice model. Both fCS-Ib and fCS-Pg had significant effects on lipid profile improvement, liver protection, blood glucose diminution and hepatic glycogen synthesis. Specifically, fCS-Pg with 3,4-O-disulfation fucose branches was more effective in reduction of blood cholesterol (TC), low density lipoprotein (LDL) and atherogenic index (AI). Our results indicate that both fCSs, especially fCS-Pg, could be used as a potential anti-hyperlipidemic drug. Copyright © 2016. Published by Elsevier Ltd.

  19. Multiple stable oxygen isotopic studies of atmospheric sulfate: A new quantitative way to understand sulfate formation processes in the atmosphere

    NASA Astrophysics Data System (ADS)

    Lee, Charles Chi-Woo

    2000-11-01

    Sulfate is an important trace species in the Earth's atmosphere because of its roles in numerous atmospheric processes. In addition to its inherent light-scattering properties, sulfate can serve as cloud condensation nucleus (CCN), affecting cloud formation as well as microphysical properties of clouds. Consequently, atmospheric sulfate species influence the global radiative energy balance. Sulfate is known to increase acidity of rainwater with negative consequences in both natural and urban environments. In addition, aerosol sulfate (<=2.5 μm) is respirable and poses a threat to human health as a potential carrier of toxic pollutants through the respiratory tract. Despite intense investigative effort, uncertainty regarding the relative significance of gas and aqueous phase oxidation pathways still remains. Acquisition of such information is important because the lifetime and transport of S(IV) species and sulfate aerosols are influenced by the oxidative pathways. In addition, sulfate formation processes affect the aerosol size distribution, which ultimately influences radiative properties of atmospheric aerosols. Therefore, the budgetary information of the sulfur cycle, as well as the radiative effects of sulfate on global climate variation, can be attained from better quantitative understanding of in situ sulfate formation processes in the atmosphere. Multiple stable oxygen isotopic studies of atmospheric sulfate are presented as a new tool to better comprehend the atmospheric sulfate formation processes. Coupled with isotopic studies, 35S radioactivity measurements have been utilized to assess contribution of sulfate from high altitude air masses. Atmospheric sulfate (aerosols and rainwater) samples have been collected from diverse environments. Laboratory experiments of gas and aqueous phase S(IV) oxidation by various oxidants, as well as biomass burning experiments, have also been conducted. The main isotopic results from these studies are as follows: (1

  20. 21 CFR 182.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum sulfate. 182.1125 Section 182.1125 Food... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in...

  1. 21 CFR 582.5997 - Zinc sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Zinc sulfate. 582.5997 Section 582.5997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is...

  2. 21 CFR 582.5997 - Zinc sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Zinc sulfate. 582.5997 Section 582.5997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is...

  3. 21 CFR 582.5997 - Zinc sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Zinc sulfate. 582.5997 Section 582.5997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is...

  4. 21 CFR 582.5997 - Zinc sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc sulfate. 582.5997 Section 582.5997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is...

  5. 21 CFR 182.8997 - Zinc sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc sulfate. 182.8997 Section 182.8997 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in...

  6. 21 CFR 182.8997 - Zinc sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc sulfate. 182.8997 Section 182.8997 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in...

  7. Low-voltage high-performance organic thin film transistors with a thermally annealed polystyrene/hafnium oxide dielectric

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Acton, Orb; Ting, Guy; Weidner, Tobias; Ma, Hong; Castner, David G.; Jen, Alex K.-Y.

    2009-12-01

    Low-voltage pentacene-based organic thin film transistors (OTFTs) are demonstrated with polystyrene (PS)/hafnium oxide (HfOx) hybrid dielectrics. Thermal annealing of PS films on HfOx at 120 °C (PS-120) induces a flatter orientation of the phenyl groups (tilt angle 65°) at the surface compared to PS films without annealing (PS-RT) (tilt angle 31°). The flatter phenyl group orientation leads to better matching of surface energy between pentacene and PS. Pentacene deposited on PS-120 display higher quality thin films with larger grain sizes and higher crystallinity. Pentacene OTFTs with PS-120/HfOx hybrid dielectrics can operate at low-voltage (<3 V) with high field-effect mobilities (1 cm2/V s), high on/off current ratios (106), and low subthreshold slopes (100 mV/dec).

  8. Heterogeneous Production of Sulfate Aerosol over China.

    NASA Astrophysics Data System (ADS)

    Shao, J.; Alexander, B.; Chen, Q.; Zhang, L.; Wang, Y.; Xie, Z.; He, P.

    2017-12-01

    Sulfate is thought to be the main contributor to the growth of PM2.5 during the severe haze pollution over China, but most studies have shown that traditional gas- and aqueous-phase chemistry cannot explain the rapid sulfate production during haze events, suggesting a missing heterogeneous oxidation mechanism. In this work, we implement heterogeneous sulfate formation into a 3-D global chemical transport model (GEOS-Chem) to evaluate the different pathways for global and regional sulfate production, including SO2 oxidation by NO2, O3, H2O2, and TMI+O2. Heterogeneous sulfate production rates and the dominant heterogeneous sulfate formation mechanism depends on calculations of aerosol pH, which is in turn is dependent upon thermodynamic state assumptions. We evaluate the influence of aerosol pH and potential impacts of aerosol ionic strength on sulfate production rates and mechanisms in the model, and its implications for PM2.5 in Chinese haze events.

  9. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg. No. 7783-20-2) occurs...

  10. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg...

  11. 21 CFR 184.1230 - Calcium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium sulfate. 184.1230 Section 184.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1230 Calcium sulfate. (a) Calcium sulfate (CaSO4, CAS Reg. No...

  12. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg...

  13. 21 CFR 556.300 - Gentamicin sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gentamicin sulfate. 556.300 Section 556.300 Food... Tolerances for Residues of New Animal Drugs § 556.300 Gentamicin sulfate. (a) A tolerance of 0.1 part per million is established for negligible residues of gentamicin sulfate in the uncooked edible tissues of...

  14. 21 CFR 184.1230 - Calcium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium sulfate. 184.1230 Section 184.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1230 Calcium sulfate. (a) Calcium sulfate (CaSO4, CAS Reg. No...

  15. 21 CFR 556.300 - Gentamicin sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gentamicin sulfate. 556.300 Section 556.300 Food... Tolerances for Residues of New Animal Drugs § 556.300 Gentamicin sulfate. (a) A tolerance of 0.1 part per million is established for negligible residues of gentamicin sulfate in the uncooked edible tissues of...

  16. 21 CFR 556.300 - Gentamicin sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gentamicin sulfate. 556.300 Section 556.300 Food... Tolerances for Residues of New Animal Drugs § 556.300 Gentamicin sulfate. (a) A tolerance of 0.1 part per million is established for negligible residues of gentamicin sulfate in the uncooked edible tissues of...

  17. 21 CFR 184.1643 - Potassium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

  18. 21 CFR 184.1643 - Potassium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

  19. 21 CFR 184.1643 - Potassium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

  20. 21 CFR 184.1643 - Potassium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg. No. 7778-80-5) occurs.... It is prepared by the neutralization of sulfuric acid with potassium hydroxide or potassium carbonate...

  1. 21 CFR 184.1643 - Potassium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

  2. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    DOEpatents

    Zaromb, Solomon; Lawson, Daniel B.

    1994-01-01

    A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

  3. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    DOEpatents

    Zaromb, S.; Lawson, D.B.

    1994-02-15

    A process for recovering zinc-rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered by distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10 C, separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream. 1 figure.

  4. Divergent Synthesis of Heparan Sulfate Oligosaccharides

    PubMed Central

    2015-01-01

    Heparan sulfates are implicated in a wide range of biological processes. A major challenge in deciphering their structure and activity relationship is the synthetic difficulties to access diverse heparan sulfate oligosaccharides with well-defined sulfation patterns. In order to expedite the synthesis, a divergent synthetic strategy was developed. By integrating chemical synthesis and two types of O-sulfo transferases, seven different hexasaccharides were obtained from a single hexasaccharide precursor. This approach combined the flexibility of chemical synthesis with the selectivity of enzyme-catalyzed sulfations, thus simplifying the overall synthetic operations. In an attempt to establish structure activity relationships of heparan sulfate binding with its receptor, the synthesized oligosaccharides were incorporated onto a glycan microarray, and their bindings with a growth factor FGF-2 were examined. The unique combination of chemical and enzymatic approaches expanded the capability of oligosaccharide synthesis. In addition, the well-defined heparan sulfate structures helped shine light on the fine substrate specificities of biosynthetic enzymes and confirm the potential sequence of enzymatic reactions in biosynthesis. PMID:26574650

  5. Passivation of InP heterojunction bipolar transistors by strain controlled plasma assisted electron beam evaporated hafnium oxide

    NASA Astrophysics Data System (ADS)

    Driad, R.; Sah, R. E.; Schmidt, R.; Kirste, L.

    2012-01-01

    We present structural, stress, and electrical properties of plasma assisted e-beam evaporated hafnium dioxide (HfO2) layers on n-type InP substrates. These layers have subsequently been used for surface passivation of InGaAs/InP heterostructure bipolar transistors either alone or in combination with plasma enhanced chemical vapor deposited SiO2 layers. The use of stacked HfO2/SiO2 results in better interface quality with InGaAs/InP heterostructures, as illustrated by smaller leakage current and improved breakdown voltage. These improvements can be attributed to the reduced defect density and charge trapping at the dielectric-semiconductor interface. The deposition at room temperature makes these films suitable for sensitive devices.

  6. Chemoenzymatic synthesis and structural characterization of 2-O-sulfated glucuronic acid-containing heparan sulfate hexasaccharides

    PubMed Central

    Hsieh, Po-Hung; Xu, Yongmei; Keire, David A; Liu, Jian

    2014-01-01

    Heparan sulfate and heparin are highly sulfated polysaccharides that consist of a repeating disaccharide unit of glucosamine and glucuronic or iduronic acid. The 2-O-sulfated iduronic acid (IdoA2S) residue is commonly found in heparan sulfate and heparin; however, 2-O-sulfated glucuronic acid (GlcA2S) is a less abundant monosaccharide (∼<5% of total saccharides). Here, we report the synthesis of three GlcA2S-containing hexasaccharides using a chemoenzymatic approach. For comparison purposes, additional IdoA2S-containing hexasaccharides were synthesized. Nuclear magnetic resonance analyses were performed to obtain full chemical shift assignments for the GlcA2S- and IdoA2S-hexasaccharides. These data show that GlcA2S is a more structurally rigid saccharide residue than IdoA2S. The antithrombin (AT) binding affinities of a GlcA2S- and an IdoA2S-hexasaccharide were determined by affinity co-electrophoresis. In contrast to IdoA2S-hexasaccharides, the GlcA2S-hexasaccharide does not bind to AT, confirming that the presence of IdoA2S is critically important for the anticoagulant activity. The availability of pure synthetic GlcA2S-containing oligosaccharides will allow the investigation of the structure and activity relationships of individual sites in heparin or heparan sulfate. PMID:24770491

  7. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS...

  8. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS Reg. No. 10034-99-8) occurs...

  9. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS...

  10. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS...

  11. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and....1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6), also known as Glauber's salt... by the neutralization of sulfuric acid with sodium hydroxide. (b) The ingredient is used as a...

  12. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b) The...

  13. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b) The...

  14. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b) The...

  15. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b) The...

  16. Complex Sulfate Deposits in Coprates Chasma

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image of layered sulfate-containing deposits in the Coprates Chasma region of Mars was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1827UTC (1:27 p.m. EST) on December 12, 2006 near 10.2 degrees south latitude, 68.8 degrees west longitude. The image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 40 meters (132 feet) across. The image is about 11 kilometers (6.8 miles) wide at its narrowest point.

    Coprates Chasma forms part of the backbone of the Valles Marineris canyon system. It extends approximately east-west for roughly 966 kilometers (600 miles), and is one of the larger chasmata in the Valles Marineris system.

    The top panel in the montage above shows the location of the CRISM image on a mosaic taken by the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS). The CRISM data covers an area centered on a knob near the chasma's northern wall.

    The center left image, an infrared false color image, shows the knob's layered morphology. The center right image unveils the mineralogical signatures of some of those layers, with yellow representing monohydrated sulfates (sulfates with one water molecule incorporated into each molecule of the mineral) and purple representing polyhydrated sulfates (sulfates with multiple waters per mineral molecule).

    The lower two images are renderings of data draped over topography with 3 times vertical exaggeration. These images provide a view of the topography and reveal how the sulfate deposits relate to that topography. Darker polyhydrated sulfates (purple) lie along the knob's western flank. Brighter, monohydrated sulfates (yellow) appear to be superimposed on polyhydrated sulfate deposits in the southwest corner of the image. These coarsely banded deposits continue along the southeast side of the knob.

    There are two possible explanations for the compositional banding of these sulfates. The first is deposition of

  17. Regeneration of sulfated metal oxides and carbonates

    DOEpatents

    Hubble, Bill R.; Siegel, Stanley; Cunningham, Paul T.

    1978-03-28

    Alkali metal or alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate found in dolomite or limestone are employed for removal of sulfur dioxide from combustion exhaust gases. The sulfated carbonates are regenerated to oxides through use of a solid-solid reaction, particularly calcium sulfide with calcium sulfate to form calcium oxide and sulfur dioxide gas. The regeneration is performed by contacting the sulfated material with a reductant gas such as hydrogen within an inert diluent to produce calcium sulfide in mixture with the sulfate under process conditions selected to permit the sulfide-sulfate, solid-state reaction to occur.

  18. The fate of sulfate in chronic heart failure

    PubMed Central

    Koning, Anne M.; Meijers, Wouter C.; Minović, Isidor; Post, Adrian; Feelisch, Martin; Pasch, Andreas; Leuvenink, Henri G. D.; de Boer, Rudolf A.; Bakker, Stephan J. L.

    2017-01-01

    New leads to advance our understanding of heart failure (HF) pathophysiology are urgently needed. Previous studies have linked urinary sulfate excretion to a favorable cardiovascular risk profile. Sulfate is not only the end product of hydrogen sulfide metabolism but is also directly involved in various (patho)physiological processes, provoking scientific interest in its renal handling. This study investigates sulfate clearance in chronic HF (CHF) patients and healthy individuals and considers its relationship with disease outcome. Parameters related to renal sulfate handling were determined in and compared between 96 previously characterized CHF patients and sex-matched healthy individuals. Among patients, sulfate clearance was analyzed for associations with clinical and outcome parameters. In CHF patients, plasma sulfate concentrations are significantly higher, whereas 24-h urinary excretion, fractional excretion, and clearance of sulfate are significantly lower, compared with healthy individuals. Among patients, sulfate clearance is independently associated with diuretics use, creatinine clearance and 24-h urinary sodium excretion. Sulfate clearance is associated with favorable disease outcome [hazard ratio per SD increase 0.38 (95% confidence interval 0.23–0.63), P < 0.001]. Although significance was lost after adjustment for creatinine clearance, the decrease of sulfate clearance in patients is independent of this parameter, indicating that sulfate clearance is not merely a reflection of renal function. This exploratory study reveals aberrant sulfate clearance as a potential contributor to CHF pathophysiology, with reduced levels in patients and a positive association with favorable disease outcome. Further research is needed to unravel the nature of its involvement and to determine its potential as a biomarker and target for therapy. NEW & NOTEWORTHY Sulfate clearance is decreased in chronic heart failure patients compared with healthy individuals. Among

  19. 21 CFR 184.1230 - Calcium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium sulfate. 184.1230 Section 184.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1230 Calcium sulfate. (a) Calcium sulfate (CaSO4, CAS Reg. No. 7778-18-9 or CaSO4·2H2O, CAS...

  20. Sulfation in lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Catherino, Henry A.; Feres, Fred F.; Trinidad, Francisco

    Virtually, all military land vehicle systems use a lead-acid battery to initiate an engine start. The maintainability of these batteries and as a consequence, system readiness, has suffered from a lack of understanding of the reasons for battery failure. Often, the term most commonly heard for explaining the performance degradation of lead-acid batteries is the word, sulfation. Sulfation is a residual term that came into existence during the early days of lead-acid battery development. The usage is part of the legend that persists as a means for interpreting and justifying the eventual performance deterioration and failure of lead-acid batteries. The usage of this term is confined to the greater user community and, over time, has encouraged a myriad of remedies for solving sulfation problems. One can avoid the connotations associated with the all-inclusive word, sulfation by visualizing the general "sulfation" effect in terms of specific mechanistic models. Also, the mechanistic models are essential for properly understanding the operation and making proper use this battery system. It is evident that the better the model, the better the level of understanding.

  1. Integrated Spectroscopic Studies of Anhydrous Sulfate Minerals

    NASA Technical Reports Server (NTRS)

    Lane, M. D.; Bishop, J. L.; Dyar, M. D.; Cloutis, E.; Forray, F. L.; Hiroi, T.

    2005-01-01

    Sulfates have been identified in Martian soils and bedrock and are emerging as an important indicator for aqueous activity on Mars. Sulfate minerals can form in a variety of low-temperature (evaporitic; chemical-weathering) and high-temperature (volcanic/fumarolic; hydrothermal) environments and their formational environments can range from alkaline to acidic. Although sulfates generally form in the presence of water, not all sulfates are hydrous or contain water in their structures. Many of these anhydrous sulfates (Dana group 28; Strunz class 67A) are minerals that form as accompanying phases to the main minerals in ore deposits or as replacement deposits in sedimentary rocks. However, some form from thermal decomposition of OH or H2O-bearing sulfates, such as from the reaction [1]: jarosite = yavapaiite + Fe2O3 + H2O. Where known, the stability fields of these minerals all suggest that they would be stable under martian surface conditions [2]. Thus, anhydrous sulfate minerals may contribute to martian surface mineralogy, so they must be well-represented in spectral libraries used for interpretation of the Martian surface. We present here the preliminary results of an integrated study of emittance, reflectance, and Mossbauer spectroscopy of a suite of wel-lcharacterized anhydrous sulfates.

  2. Cesium hafnium chloride: A high light yield, non-hygroscopic cubic crystal scintillator for gamma spectroscopy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burger, Arnold, E-mail: aburger@fisk.edu; Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235; Rowe, Emmanuel

    We report on the scintillation properties of Cs{sub 2}HfCl{sub 6} (cesium hafnium chloride or CHC) as an example of a little-known class of non-hygroscopic compounds having the generic cubic crystal structure of K{sub 2}PtCl{sub 6}. The crystals are easily growable from the melt using the Bridgman method with minimal precursor treatments or purification. CHC scintillation is centered at 400 nm, with a principal decay time of 4.37 μs and a light yield of up to 54 000 photons/MeV when measured using a silicon CCD photodetector. The light yield is the highest ever reported for an undoped crystal, and CHC also exhibits excellent lightmore » yield nonproportionality. These desirable properties allowed us to build and test CHC gamma-ray spectrometers providing energy resolution of 3.3% at 662 keV.« less

  3. Setting constraints on the nature and origin of the two major hydrous sulfates on Mars: Monohydrated and polyhydrated sulfates

    NASA Astrophysics Data System (ADS)

    Wang, Alian; Jolliff, Bradley L.; Liu, Yang; Connor, Kathryn

    2016-04-01

    Monohydrated Mg sulfate (MgSO4·H2O) and polyhydrated sulfate are the most common and abundant hydrous sulfates observed thus far on Mars. They are widely distributed and coexist in many locations. On the basis of results from two new sets of experiments, in combination with past experimental studies and the subsurface salt mineralogy observed at a saline playa (Dalangtan, DLT) in a terrestrial analogue hyperarid region on the Tibet Plateau, we can now set new constraints on the nature and origin of these two major Martian sulfates. Starkeyite (MgSO4·4H2O) is the best candidate for polyhydrated sulfate. MgSO4·H2O in the form of "LH-1w," generated from dehydration of Mg sulfates with high degrees of hydration, is the most likely mineral form for the majority of Martian monohydrated Mg sulfate. Two critical properties of Mg sulfates are responsible for the coexistence of these two phases that have very different degrees of hydration: (1) the metastability of a substructural unit in starkeyite at relatively low temperatures, and (2) catalytic effects attributed to coprecipitated species (sulfates, chlorides, oxides, and hydroxides) from chemically complex brines that help overcome the metastability of starkeyite. The combination of these two properties controls the coexistence of the LH-1w layer and starkeyite layers at many locations on Mars, which sometimes occur in an interbedded stratigraphy. The structural H2O held by these two broadly distributed sulfates represents a large H2O reservoir at the surface and in the shallow subsurface on current Mars.

  4. 21 CFR 522.650 - Dihydrostreptomycin sulfate injection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dihydrostreptomycin sulfate injection. 522.650... § 522.650 Dihydrostreptomycin sulfate injection. (a) Specifications. Each milliliter contains dihydrostreptomycin sulfate equivalent to 500 milligrams of dihydrostreptomycin. (b) Sponsors. See Nos. 054771 and...

  5. Benzene oxidation coupled to sulfate reduction

    USGS Publications Warehouse

    Lovley, D.R.; Coates, J.D.; Woodward, J.C.; Phillips, E.J.P.

    1995-01-01

    Highly reduced sediments from San Diego Bay, Calif., that were incubated under strictly anaerobic conditions metabolized benzene within 55 days when they were exposed initially to I ??M benzene. The rate of benzene metabolism increased as benzene was added back to the benzene-adapted sediments. When a [14C]benzene tracer was included with the benzene added to benzene-adapted sediments, 92% of the added radioactivity was recovered as 14CO2. Molybdate, an inhibitor of sulfate reduction, inhibited benzene uptake and production of 14CO2 from [14C]benzene. Benzene metabolism stopped when the sediments became sulfate depleted, and benzene uptake resumed when sulfate was added again. The stoichiometry of benzene uptake and sulfate reduction was consistent with the hypothesis that sulfate was the principal electron acceptor for benzene oxidation. Isotope trapping experiments performed with [14C]benzene revealed that there was no production of such potential extracellular intermediates of benzene oxidation as phenol, benzoate, p-hydroxybenzoate, cyclohexane, catechol, and acetate. The results demonstrate that benzene can be oxidized in the absence of O2, with sulfate serving as the electron acceptor, and suggest that some sulfate reducers are capable of completely oxidizing benzene to carbon dioxide without the production of extracellular intermediates. Although anaerobic benzene oxidation coupled to chelated Fe(III) has been documented previously, the study reported here provides the first example of a natural sediment compound that can serve as an electron acceptor for anaerobic benzene oxidation.

  6. Sulfation and Cation Effects on the Conformational Properties of the Glycan Backbone of Chondroitin Sulfate Disaccharides

    PubMed Central

    Faller, Christina E.; Guvench, Olgun

    2015-01-01

    Chondroitin sulfate (CS) is one of several glycosaminoglycans that are major components of proteoglycans. A linear polymer consisting of repeats of the disaccharide -4GlcAβ1-3GalNAcβ1-, CS undergoes differential sulfation resulting in five unique sulfation patterns. Because of the dimer repeat, the CS glycosidic “backbone” has two distinct sets of conformational degrees of freedom defined by pairs of dihedral angles: (ϕ1, ψ1) about the β1-3 glycosidic linkage and (ϕ2, ψ2) about the β1-4 glycosidic linkage. Differential sulfation and the possibility of cation binding, combined with the conformational flexibility and biological diversity of CS, complicate experimental efforts to understand CS three-dimensional structures at atomic resolution. Therefore, all-atom explicit-solvent molecular dynamics simulations with Adaptive Biasing Force sampling of the CS backbone were applied to obtain high resolution, high precision free energies of CS disaccharides as a function of all possible backbone geometries. All ten disaccharides (β1-3 vs. β1-4 linkage x five different sulfation patterns) were studied; additionally, ion effects were investigated by considering each disaccharide in the presence of either neutralizing sodium or calcium cations. GlcAβ1-3GalNAc disaccharides have a single, broad, thermodynamically important free-energy minimum whereas GalNAcβ1-4GlcA disaccharides have two such minima. Calcium cations but not sodium cations bind to the disaccharides, and binding is primarily to the GlcA –COO− moiety as opposed to sulfate groups. This binding alters the glycan backbone thermodynamics in instances where a calcium cation bound to –COO− can act to bridge and stabilize an interaction with an adjacent sulfate group, whereas, in the absence of this cation, the proximity of a sulfate group to –COO− results in two like charges being both desolvated and placed adjacent to each other and is found to be destabilizing. In addition to providing

  7. Sulfation and cation effects on the conformational properties of the glycan backbone of chondroitin sulfate disaccharides.

    PubMed

    Faller, Christina E; Guvench, Olgun

    2015-05-21

    Chondroitin sulfate (CS) is one of several glycosaminoglycans that are major components of proteoglycans. A linear polymer consisting of repeats of the disaccharide -4GlcAβ1-3GalNAcβ1-, CS undergoes differential sulfation resulting in five unique sulfation patterns. Because of the dimer repeat, the CS glycosidic "backbone" has two distinct sets of conformational degrees of freedom defined by pairs of dihedral angles: (ϕ1, ψ1) about the β1-3 glycosidic linkage and (ϕ2, ψ2) about the β1-4 glycosidic linkage. Differential sulfation and the possibility of cation binding, combined with the conformational flexibility and biological diversity of CS, complicate experimental efforts to understand CS three-dimensional structures at atomic resolution. Therefore, all-atom explicit-solvent molecular dynamics simulations with Adaptive Biasing Force sampling of the CS backbone were applied to obtain high-resolution, high-precision free energies of CS disaccharides as a function of all possible backbone geometries. All 10 disaccharides (β1-3 vs β1-4 linkage × five different sulfation patterns) were studied; additionally, ion effects were investigated by considering each disaccharide in the presence of either neutralizing sodium or calcium cations. GlcAβ1-3GalNAc disaccharides have a single, broad, thermodynamically important free-energy minimum, whereas GalNAcβ1-4GlcA disaccharides have two such minima. Calcium cations but not sodium cations bind to the disaccharides, and binding is primarily to the GlcA -COO(-) moiety as opposed to sulfate groups. This binding alters the glycan backbone thermodynamics in instances where a calcium cation bound to -COO(-) can act to bridge and stabilize an interaction with an adjacent sulfate group, whereas, in the absence of this cation, the proximity of a sulfate group to -COO(-) results in two like charges being both desolvated and placed adjacent to each other and is found to be destabilizing. In addition to providing information

  8. Tyrosine sulfation in precursors of collagen V.

    PubMed

    Fessler, L I; Brosh, S; Chapin, S; Fessler, J H

    1986-04-15

    Radioactive labeling of p-collagens V, collagens V, and, to a small extent, of procollagen V occurred when [35S]sulfate was incubated with tendons or primary tendon cell cultures, or blood vessels and crops of 17- to 19-day-old chick embryos, or with lung slices from neonatal rats. Most or all of this label is in the form of 1 or more sulfated tyrosine residues/chain of p alpha 1(V), alpha 1(V), p alpha 1'(V), alpha 1'(V), p alpha 2(V), and alpha 2(V), and it remains attached through purification by dialysis, ammonium sulfate precipitation, CsCl-GdnCl2 equilibrium buoyant density and velocity sedimentations, ion-exchange chromatography, and sodium dodecyl sulfate gel electrophoresis. Radioactive tyrosine sulfate was identified in alkaline hydrolysates of these collagen V chains, after labeling the tissues with either [35S]sulfate or [3H]tyrosine, by electrophoretic and chromatographic comigration with a tyrosine sulfate standard. Tunicamycin A1, which inhibits the attachment of N-linked complex carbohydrate, did not interfere with the sulfation process. The tyrosine sulfate is located in a noncollagenous domain, which is probably adjacent to the amino end of the collagen helix, and is retained throughout the physiological proteolytic processing of procollagens V. After digestion with Staphylococcus aureus V8 protease, 35S-labeled p alpha 1(V) and alpha 1(V) chains gave the same map of labeled peptides, and this differed from the map given by p alpha 1'(V) and alpha 1'(V) chains. Little sulfation of p alpha 2(V) and alpha 2(V) chains occurs. The implications of these observations for the structure and properties of procollagens V and their derivatives are considered.

  9. 21 CFR 520.1044c - Gentamicin sulfate powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gentamicin sulfate powder. 520.1044c Section 520... sulfate powder. (a) Specifications. Each gram of powder contains gentamicin sulfate equivalent to: (1) 16... colibacillosis: Gentamicin sulfate equivalent to 25 mg of gentamicin per gallon of drinking water to provide 0.5...

  10. 21 CFR 520.1044c - Gentamicin sulfate powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gentamicin sulfate powder. 520.1044c Section 520... sulfate powder. (a) Specifications. Each gram of powder contains gentamicin sulfate equivalent to: (1) 16... colibacillosis: Gentamicin sulfate equivalent to 25 mg of gentamicin per gallon of drinking water to provide 0.5...

  11. The combined therapy with chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride does not improve joint damage in an experimental model of knee osteoarthritis in rabbits.

    PubMed

    Roman-Blas, Jorge A; Mediero, Aránzazu; Tardío, Lidia; Portal-Nuñez, Sergio; Gratal, Paula; Herrero-Beaumont, Gabriel; Largo, Raquel

    2017-01-05

    Osteoarthritis is the most common chronic joint disorder especially during aging. Although with controversies, glucosamine, both in its forms of sulfate and hydrochloride, and chondroitin sulfate are commonly employed to treat osteoarthritis. Due to the modest improve in the symptoms observed in patients treated with these drugs alone, a formulation combining both agents has been considered. The discrepant results achieved for pain control or structural improvement in osteoarthritis patients has been attributed to the quality of chemical formulations or different bias in clinical studies. The current study has been designed to test the effects of two different combined formulations with adequate pharmaceutical grade of these drugs in osteoarthritic joints, and to explore the underlying mechanisms modulated by both formulations in different osteoarthritis target tissues. Knee osteoarthritis was surgically induced in experimental rabbits. Some animals received the combined therapy (CT)1, (chondroitin sulfate 1200mg/day + glucosamine sulfate 1500mg/day), or the CT2 ((chondroitin sulfate 1200mg/day + glucosamine hydrochloride 1500mg/day). Neither CT1 nor CT2 significantly modified the cartilage damage or the synovial inflammation observed in osteoarthritic animals. Treatments were also unable to modify the presence of pro-inflammatory mediators, and the synthesis of metalloproteinases in the cartilage or in the synovium of osteoarthritic animals. Combined therapies did not modify the decrease in the subchondral bone mineral density observed in osteoarthritic rabbits. Therapies of chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride failed to improve structural damage or to ameliorate the inflammatory profile of joint tissues during experimental osteoarthritis. Published by Elsevier B.V.

  12. Highly sulfated hexasaccharide sequences isolated from chondroitin sulfate of shark fin cartilage: insights into the sugar sequences with bioactivities.

    PubMed

    Mizumoto, Shuji; Murakoshi, Saori; Kalayanamitra, Kittiwan; Deepa, Sarama Sathyaseelan; Fukui, Shigeyuki; Kongtawelert, Prachya; Yamada, Shuhei; Sugahara, Kazuyuki

    2013-02-01

    Chondroitin sulfate (CS) chains regulate the development of the central nervous system in vertebrates and are linear polysaccharides consisting of variously sulfated repeating disaccharides, [-4GlcUAβ1-3GalNAcβ1-](n), where GlcUA and GalNAc represent D-glucuronic acid and N-acetyl-D-galactosamine, respectively. CS chains containing D-disaccharide units [GlcUA(2-O-sulfate)-GalNAc(6-O-sulfate)] are involved in the development of cerebellar Purkinje cells and neurite outgrowth-promoting activity through interaction with a neurotrophic factor, pleiotrophin, resulting in the regulation of signaling. In this study, to obtain further structural information on the CS chains containing d-disaccharide units involved in brain development, oligosaccharides containing D-units were isolated from a shark fin cartilage. Seven novel hexasaccharide sequences, ΔO-D-D, ΔA-D-D, ΔC-D-D, ΔE-A-D, ΔD-D-C, ΔE-D-D and ΔA-B-D, in addition to three previously reported sequences, ΔC-A-D, ΔC-D-C and ΔA-D-A, were isolated from a CS preparation of shark fin cartilage after exhaustive digestion with chondroitinase AC-I, which cannot act on the galactosaminidic linkages bound to D-units. The symbol Δ stands for a 4,5-unsaturated bond of uronic acids, whereas A, B, C, D, E and O represent [GlcUA-GalNAc(4-O-sulfate)], [GlcUA(2-O-sulfate)-GalNAc(4-O-sulfate)], [GlcUA-GalNAc(6-O-sulfate)], [GlcUA(2-O-sulfate)-GalNAc(6-O-sulfate)], [GlcUA-GalNAc(4-O-, 6-O-sulfate)] and [GlcUA-GalNAc], respectively. In binding studies using an anti-CS monoclonal antibody, MO-225, the epitopes of which are involved in cerebellar development in mammals, novel epitope structures, ΔA-D-A, ΔA-D-D and ΔA-B-D, were revealed. Hexasaccharides containing two consecutive D-units or a B-unit will be useful for the structural and functional analyses of CS chains particularly in the neuroglycobiological fields.

  13. Protein Precipitation Using Ammonium Sulfate.

    PubMed

    2016-04-01

    The basic theory of protein precipitation by addition of ammonium sulfate is presented, and the most common applications are listed. Tables are provided for calculating the appropriate amount of ammonium sulfate to add to a particular protein solution. Copyright © 2016 John Wiley & Sons, Inc.

  14. A modified sulfate process to lunar oxygen

    NASA Technical Reports Server (NTRS)

    Sullivan, Thomas A.

    1992-01-01

    A modified sulfate process which produces oxygen from iron oxide-bearing minerals in lunar soil is under development. Reaction rates of ilmenite in varying strength sulfuric acid have been determined. Quantitative conversion of ilmenite to ferrous sulfate was observed over a range of temperatures and concentrations. Data has also been developed on the calcination of by-product sulfates. System engineering for overall operability and simplicity has begun, suggesting that a process separating the digestion and sulfate dissolution steps may offer an optimum process.

  15. 21 CFR 522.1204 - Kanamycin sulfate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Kanamycin sulfate injection. 522.1204 Section 522.1204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....1204 Kanamycin sulfate injection. (a) Specifications. Each milliliter of kanamycin sulfate injection...

  16. 21 CFR 522.1204 - Kanamycin sulfate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Kanamycin sulfate injection. 522.1204 Section 522.1204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....1204 Kanamycin sulfate injection. (a) Specifications. Each milliliter of kanamycin sulfate injection...

  17. 21 CFR 522.1204 - Kanamycin sulfate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Kanamycin sulfate injection. 522.1204 Section 522.1204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....1204 Kanamycin sulfate injection. (a) Specifications. Each milliliter of kanamycin sulfate injection...

  18. 21 CFR 522.1204 - Kanamycin sulfate injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Kanamycin sulfate injection. 522.1204 Section 522.1204 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....1204 Kanamycin sulfate injection. (a) Specifications. Each milliliter of kanamycin sulfate injection...

  19. Process for removing sulfate anions from waste water

    DOEpatents

    Nilsen, David N.; Galvan, Gloria J.; Hundley, Gary L.; Wright, John B.

    1997-01-01

    A liquid emulsion membrane process for removing sulfate anions from waste water is disclosed. The liquid emulsion membrane process includes the steps of: (a) providing a liquid emulsion formed from an aqueous strip solution and an organic phase that contains an extractant capable of removing sulfate anions from waste water; (b) dispersing the liquid emulsion in globule form into a quantity of waste water containing sulfate anions to allow the organic phase in each globule of the emulsion to extract and absorb sulfate anions from the waste water and (c) separating the emulsion including its organic phase and absorbed sulfate anions from the waste water to provide waste water containing substantially no sulfate anions.

  20. Characterization of the interaction of interleukin-8 with hyaluronan, chondroitin sulfate, dermatan sulfate and their sulfated derivatives by spectroscopy and molecular modeling.

    PubMed

    Pichert, Annelie; Samsonov, Sergey A; Theisgen, Stephan; Thomas, Lars; Baumann, Lars; Schiller, Jürgen; Beck-Sickinger, Annette G; Huster, Daniel; Pisabarro, M Teresa

    2012-01-01

    The interactions between glycosaminoglycans (GAGs), important components of the extracellular matrix, and proteins such as growth factors and chemokines play critical roles in cellular regulation processes. Therefore, the design of GAG derivatives for the development of innovative materials with bio-like properties in terms of their interaction with regulatory proteins is of great interest for tissue engineering and regenerative medicine. Previous work on the chemokine interleukin-8 (IL-8) has focused on its interaction with heparin and heparan sulfate, which regulate chemokine function. However, the extracellular matrix contains other GAGs, such as hyaluronic acid (HA), dermatan sulfate (DS) and chondroitin sulfate (CS), which have so far not been characterized in terms of their distinct molecular recognition properties towards IL-8 in relation to their length and sulfation patterns. NMR and molecular modeling have been in great part the methods of choice to study the structural and recognition properties of GAGs and their protein complexes. However, separately these methods have challenges to cope with the high degree of similarity and flexibility that GAGs exhibit. In this work, we combine fluorescence spectroscopy, NMR experiments, docking and molecular dynamics simulations to study the configurational and recognition properties of IL-8 towards a series of HA and CS derivatives and DS. We analyze the effects of GAG length and sulfation patterns in binding strength and specificity, and the influence of GAG binding on IL-8 dimer formation. Our results highlight the importance of combining experimental and theoretical approaches to obtain a better understanding of the molecular recognition properties of GAG-protein systems.

  1. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b...

  2. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of...

  3. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b...

  4. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b...

  5. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of use. This substance is generally...

  6. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of...

  7. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of...

  8. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of...

  9. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b...

  10. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

  11. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

  12. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

  13. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

  14. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

  15. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum sodium sulfate. 182.1131 Section 182.1131...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use. This substance is generally...

  16. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

  17. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

  18. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

  19. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum potassium sulfate. 182.1129 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of use. This substance is generally...

  20. A potential role for chondroitin sulfate/dermatan sulfate in arm regeneration in Amphiura filiformis.

    PubMed

    Ramachandra, Rashmi; Namburi, Ramesh B; Dupont, Sam T; Ortega-Martinez, Olga; van Kuppevelt, Toin H; Lindahl, Ulf; Spillmann, Dorothe

    2017-05-01

    Glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) and dermatan sulfate (DS) from various vertebrate and invertebrate sources are known to be involved in diverse cellular mechanisms during repair and regenerative processes. Recently, we have identified CS/DS as the major GAG in the brittlestar Amphiura filiformis, with high proportions of di- and tri-O-sulfated disaccharide units. As this echinoderm is known for its exceptional regeneration capacity, we aimed to explore the role of these GAG chains during A. filiformis arm regeneration. Analysis of CS/DS chains during the regeneration process revealed an increase in the proportion of the tri-O-sulfated disaccharides. Conversely, treatment of A. filiformis with sodium chlorate, a potent inhibitor of sulfation reactions in GAG biosynthesis, resulted in a significant reduction in arm growth rates with total inhibition at concentrations higher than 5 mM. Differentiation was less impacted by sodium chlorate exposure or even slightly increased at 1-2 mM. Based on the structural changes observed during arm regeneration we identified chondroitin synthase, chondroitin-4-O-sulfotransferase 2 and dermatan-4-O-sulfotransferase as candidate genes and sought to correlate their expression with the expression of the A. filiformis orthologue of bone morphogenetic factors, AfBMP2/4. Quantitative amplification by real-time PCR indicated increased expression of chondroitin synthase and chondroitin-4-O-sulfotransferase 2, with a corresponding increase in AfBMP2/4 during regeneration relative to nonregenerating controls. Our findings suggest that proper sulfation of GAGs is important for A. filiformis arm regeneration and that these molecules may participate in mechanisms controlling cell proliferation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Phyllosilicate and Hydrated Sulfate Deposits in Meridiani

    NASA Technical Reports Server (NTRS)

    Wiseman, S. M.; Avidson, R. E.; Murchie, S.; Poulet, F.; Andrews-Hanna, J. C.; Morris, R. V.; Seelos, F. P.

    2008-01-01

    Several phyllosilicate and hydrated sulfate deposits in Meridiani have been mapped in detail with high resolution MRO CRISM [1] data. Previous studies have documented extensive exposures of outcrop in Meridiani (fig 1), or etched terrain (ET), that has been interpreted to be sedimentary in origin [e.g., 2,3]. These deposits have been mapped at a regional scale with OMEGA data and show enhanced hydration (1.9 m absorption) in several areas [4]. However, hydrated sulfate detections were restricted to valley exposures in northern Meridiani ET [5]. New high resolution CRISM images show that hydrated sulfates are present in several spatially isolated exposures throughout the ET (fig 1). The hydrated sulfate deposits in the valley are vertically heterogeneous with layers of mono and polyhydrated sulfates and are morphologically distinct from other areas of the ET. We are currently mapping the detailed spatial distribution of sulfates and searching for distinct geochemical horizons that may be traced back to differential ground water recharge and/or evaporative loss rates. The high resolution CRISM data has allowed us to map out several phyllosilicate deposits within the fluvially dissected Noachian cratered terrain (DCT) to the south and west of the hematite-bearing plains (Ph) and ET (fig 1). In Miyamoto crater, phyllosilicates are located within 30km of the edge of Ph, which is presumably underlain by acid sulfate deposits similar to those explored by Opportunity. The deposits within this crater may record the transition from fluvial conditions which produced and/or preserved phyllosilicates deposits to a progressively acid sulfate dominated groundwater system in which large accumulations of sulfate-rich evaporites were deposited .

  2. Effective Synthesis of Sulfate Metabolites of Chlorinated Phenols

    PubMed Central

    Lehmler, Hans-Joachim; He, Xianran; Li, Xueshu; Duffel, Michael W.; Parkin, Sean

    2013-01-01

    Chlorophenols are an important class of persistent environmental contaminants and have been implicated in a range of adverse health effects, including cancer. They are readily conjugated and excreted as the corresponding glucuronides and sulfates in the urine of humans and other species. Here we report the synthesis and characterization of a series of ten chlorophenol sulfates by sulfation of the corresponding chlorophenols with 2,2,2-trichloroethyl (TCE) chlorosulfate using N,N-dimethylaminopyridine (DMAP) as base. Deprotection of the chlorophenol diesters with zinc powder/ammonium formate yielded the respective chlorophenol sulfate ammonium salts in good yield. The molecular structure of three TCE-protected chlorophenol sulfate diesters and one chlorophenol sulfate monoester were confirmed by X-ray crystal structure analysis. The chlorophenol sulfates were stable for several months if stored at −20 °C and, thus, are useful for future toxicological, environmental and human biomonitoring studies. PMID:23906814

  3. Sulfate was a trace constituent of Archean seawater.

    PubMed

    Crowe, Sean A; Paris, Guillaume; Katsev, Sergei; Jones, CarriAyne; Kim, Sang-Tae; Zerkle, Aubrey L; Nomosatryo, Sulung; Fowle, David A; Adkins, Jess F; Sessions, Alex L; Farquhar, James; Canfield, Donald E

    2014-11-07

    In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column of Lake Matano, Indonesia, a low-sulfate analog for the Archean ocean, we find large (>20 per mil) sulfur isotope fractionations between sulfate and sulfide, but the underlying sediment sulfides preserve a muted range of δ(34)S values. Using models informed by sulfur cycling in Lake Matano, we infer Archean seawater sulfate concentrations of less than 2.5 micromolar. At these low concentrations, marine sulfate residence times were likely 10(3) to 10(4) years, and sulfate scarcity would have shaped early global biogeochemical cycles, possibly restricting biological productivity in Archean oceans. Copyright © 2014, American Association for the Advancement of Science.

  4. The preparation and antioxidant activity of glucosamine sulfate

    NASA Astrophysics Data System (ADS)

    Xing, Ronge; Liu, Song; Wang, Lin; Cai, Shengbao; Yu, Huahua; Feng, Jinhua; Li, Pengcheng

    2009-05-01

    Glucosamine sulfate was prepared from glucosamine hydrochloride that was produced by acidic hydrolysis of chitin by ion-exchange method. Optical rotation and elemental analysis characterized the degree of its purity. In addition, the antioxidant potency of chitosan derivative-glucosamine sulfate was investigated in various established in vitro systems, such as superoxide (O{2/-})/hydroxyl (·OH) radicals scavenging, reducing power, iron ion chelating. The following results are obtained: first, glucosamine sulfate had pronounced scavenging effect on superoxide radical. For example the O{2/-} scavenging activity of glucosamine sulfate was 92.11% at 0.8 mg/mL. Second, the ·OH scavenging activity of glucosamine sulfate was also strong, and was about 50% at 3.2 mg/mL. Third, the reducing power of glucosamine sulfate was more pronounced. The reducing power of glucosamine sulfate was 0.643 at 0.75 mg/mL. However, its potency for ferrous ion chelating was weak. Furthermore, except for ferrous ion chelating potency, the scavenging rate of radical and reducing power of glucosamine sulfate were concentration-dependent and increased with their increasing concentrations, but its ferrous ion chelating potency decreased with the increasing concentration. The multiple antioxidant activities of glucosamine sulfate were evidents of reducing power and superoxide/hydroxyl radicals scavenging ability. These in vitro results suggest the possibility that glucosamine sulfate could be used effectively as an ingredient in health or functional food, to alleviate oxidative stress.

  5. Biological Sulfate Reduction Rates in Hydrothermal Recharge Zones

    NASA Astrophysics Data System (ADS)

    Crowell, B.; Lowell, R. P.

    2007-12-01

    We develop a model to determine the rate of removal of seawater sulfate in the recharge regions of deep-sea hydrothermal systems as a result of biogenic sulfate reduction. The rate of sulfate reduction as a function of temperature derived from laboratory measurements on cores from the Guaymas Basin in Mexico [Jorgensen et al., 1992] is incorporated into a steady state 1-D advection-diffusion temperature equation, and a 1-D, steady- state, advection dominated conservation of solute equation. The diffusivity of sulfate in seawater is on the order of ~ 10-10 m2/s, and unless the flow speeds are < 10-12 m/s, the effects of diffusion are negligible, except within thin diffusive boundary layers. This model is then compared with a model that utilizes Gibbs free energy to quantify biogenic sulfate reduction [Bach and Edwards, 2003] in the upper oceanic crust of aging lithosphere. Using the high rates determined by Jorgensen et al. [1992], our model indicates that biological activity would reduce all seawater sulfate transported into the system within the upper 10 meters or less of the crust, which is inconsistent with the estimates of Bach and Edwards [2003]. Sulfate concentrations from ODP borehole Legs 64 and 168, at the sedimented Guaymas Basin and Juan de Fuca Ridge, respectively, show that most of the seawater sulfate is removed in the upper 100 meters. If the sulfate is assumed to all be reduced biogenically, the sulfate reduction rates at the ODP sites are at least 2 orders of magnitude less than the laboratory estimates of Jorgenson et al. [1992]. Finally, we compare the rate of seawater sulfate removal as a result of the precipitation of anhydrite, with the rate of biogenic sulfate reduction. We find that if hydrothermal recharge occurs rapidly through highly permeable faults, that biogenic sulfate reduction is negligible and that anhydrite precipitation would rapidly clog the recharge zone [Lowell and Yao, 2002]. If recharge occurs through broad zones of slow

  6. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum sodium sulfate. 582.1131 Section 582.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  7. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum sodium sulfate. 582.1131 Section 582.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  8. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum sodium sulfate. 582.1131 Section 582.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  9. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum sodium sulfate. 182.1131 Section 182.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  10. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum sodium sulfate. 182.1131 Section 182.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  11. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum sodium sulfate. 582.1131 Section 582.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  12. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sodium sulfate. 182.1131 Section 182.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  13. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum sodium sulfate. 182.1131 Section 182.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  14. 21 CFR 582.5461 - Manganese sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use. This...

  15. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  16. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  17. 21 CFR 582.5461 - Manganese sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use. This...

  18. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  19. 21 CFR 582.5461 - Manganese sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use. This...

  20. 21 CFR 582.5461 - Manganese sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use. This...

  1. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  2. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  3. 21 CFR 582.5461 - Manganese sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use. This...

  4. Sulfate Metabolites of 4-Monochlorobiphenyl in Whole Poplar Plants

    PubMed Central

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2013-01-01

    4-Monochlorobiphenyl (PCB3) has been proven to be transformed into hydroxylated metabolites of PCB3 (OH-PCB3s) in whole poplar plants in our previous work. However, hydroxylated metabolites of PCBs, including OH-PCB3s, as the substrates of sulfotransferases have not been studied in many organisms including plants in vivo. Poplar (Populus deltoides × nigra, DN34) was used to investigate the further metabolism from OH-PCB3s to PCB3 sulfates because it is a model plant and one that is frequently utilized in phytoremediation. Results showed poplar plants could metabolize PCB3 into PCB3 sulfates during 25 day exposures. Three sulfate metabolites, including 2′-PCB3 sulfate, 3′-PCB3 sulfate and 4′-PCB3 sulfate, were identified in poplar roots and their concentrations increased in the roots from day 10 to day 25. The major products were 2′-PCB3 sulfate and 4′-PCB3 sulfate. However, the concentrations of PCB3 sulfates were much lower than those of OH-PCB3s in the roots, suggesting the sequential transformation of these hydroxylated PCB3 metabolites into PCB3 sulfates in whole poplars. In addition, 2′-PCB3 sulfate or 4′-PCB3 sulfate was also found in the bottom wood samples indicating some translocation or metabolism in woody tissue. Results suggested that OH-PCB3s were the substrates of sulfotransferases which catalyzed the formation of PCB3 sulfates in the metabolic pathway of PCB3. PMID:23215248

  5. Laboratory Simulated Acid-Sulfate Weathering of Basaltic Materials: Implications for Formation of Sulfates at Meridiani Planum and Gusev Crater, Mars

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, Douglas W.; Morris, Richard V.; Mertzman, A.

    2006-01-01

    Acid-sulfate weathering of basaltic materials is a candidate formation process for the sulfate-rich outcrops and rocks at the MER rover Opportunity and Spirit landing sites. To determine the style of acid-sulfate weathering on Mars, we weathered basaltic materials (olivine-rich glassy basaltic sand and plagioclase feldspar-rich basaltic tephra) in the laboratory under different oxidative, acid-sulfate conditions and characterized the alteration products. We investigated alteration by (1) sulfuric-acid vapor (acid fog), (2) three-step hydrothermal leaching treatment approximating an open system and (3) single-step hydrothermal batch treatment approximating a "closed system." In acid fog experiments, Al, Fe, and Ca sulfates and amorphous silica formed from plagioclase-rich tephra, and Mg and Ca sulfates and amorphous silica formed from the olivine-rich sands. In three-step leaching experiments, only amorphous Si formed from the plagioclase-rich basaltic tephra, and jarosite, Mg and Ca sulfates and amorphous silica formed from olivine-rich basaltic sand. Amorphous silica formed under single-step experiments for both starting materials. Based upon our experiments, jarosite formation in Meridiani outcrop is potential evidence for an open system acid-sulfate weathering regime. Waters rich in sulfuric acid percolated through basaltic sediment, dissolving basaltic phases (e.g., olivine) and forming jarosite, other sulfates, and iron oxides. Aqueous alteration of outcrops and rocks on the West Spur of the Columbia Hills may have occurred when vapors rich in SO2 from volcanic sources reacted with basaltic materials. Soluble ions from the host rock (e.g., olivine) reacted with S to form Ca-, Mg-, and other sulfates along with iron oxides and oxyhydroxides.

  6. 21 CFR 173.385 - Sodium methyl sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium methyl sulfate. 173.385 Section 173.385 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... CONSUMPTION Specific Usage Additives § 173.385 Sodium methyl sulfate. Sodium methyl sulfate may be present in...

  7. 21 CFR 173.385 - Sodium methyl sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium methyl sulfate. 173.385 Section 173.385 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... CONSUMPTION Specific Usage Additives § 173.385 Sodium methyl sulfate. Sodium methyl sulfate may be present in...

  8. 21 CFR 172.399 - Zinc methionine sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc methionine sulfate. 172.399 Section 172.399... CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

  9. 21 CFR 173.385 - Sodium methyl sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium methyl sulfate. 173.385 Section 173.385... CONSUMPTION Specific Usage Additives § 173.385 Sodium methyl sulfate. Sodium methyl sulfate may be present in... pectin by sulfuric acid and methyl alcohol and subsequent treatment with sodium bicarbonate. (b) It does...

  10. 21 CFR 582.5230 - Calcium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  11. 21 CFR 582.5230 - Calcium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  12. 21 CFR 582.5230 - Calcium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  13. 21 CFR 582.5315 - Ferrous sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5315 Ferrous sulfate. (a) Product. Ferrous sulfate. (b) Conditions of use. This substance...

  14. 21 CFR 582.5315 - Ferrous sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5315 Ferrous sulfate. (a) Product. Ferrous sulfate. (b) Conditions of use. This substance...

  15. 21 CFR 582.5315 - Ferrous sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5315 Ferrous sulfate. (a) Product. Ferrous sulfate. (b) Conditions of use. This substance...

  16. 21 CFR 582.5230 - Calcium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  17. 21 CFR 582.5315 - Ferrous sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5315 Ferrous sulfate. (a) Product. Ferrous sulfate. (b) Conditions of use. This substance...

  18. 21 CFR 582.1125 - Aluminum sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

  19. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

  20. 21 CFR 582.5230 - Calcium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  1. 21 CFR 582.5315 - Ferrous sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5315 Ferrous sulfate. (a) Product. Ferrous sulfate. (b) Conditions of use. This substance...

  2. Isolation of tungsten and tantalum isotopes without supports from. cap alpha. -particle-irradiated hafnium targets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gasita, S.M.; Iota, B.Z.; Malachkov, A.G.

    1985-11-01

    An extraction procedure has been developed for successive isolation of tungsten (/sup 178/W and /sup 181/W) and tantalum (/sup 179/Ta and /sup 182/Ta) isotopes without supports from ..cap alpha..particle-irradiated hafnium targets. The target, irradiated on a cyclotron, is dissolved in hydrofluoric acid. Tantalum isotopes are extracted with tributyl phosphate (TBP) from 1-5 M HF and are then reextracted with a 1:1 ammonia solution, and hydrofluoric acid is removed by heating. Tungsten isotopes are extracted with a chloroform solution or N-benzoyl-N-phenylhydroxylamine (BPHA) from 11-12 M H/sub 2/SO/sub 4/ or ..cap alpha..-benzoin oxime from 4.5-5.5 M H/sub 2/SO/sub 4/ and are thenmore » reextracted with a l:l ammonia solution. The yield of tungsten isotopes is not less than 95%, and the content of radioactive impurities of other isotopes is not more than 0.1%.« less

  3. Acid Sulfate Alteration on Mars

    NASA Technical Reports Server (NTRS)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  4. Tandem Mass Spectrometry of Heparan Sulfate Negative Ions: Sulfate Loss Patterns and Chemical Modification Methods for Improvement of Product Ion Profiles

    NASA Astrophysics Data System (ADS)

    Shi, Xiaofeng; Huang, Yu; Mao, Yang; Naimy, Hicham; Zaia, Joseph

    2012-09-01

    Heparan sulfate (HS) is a polysaccharide modified with sulfation, acetylation, and epimerization that enable its binding with protein ligands and regulation of important biological processes. Tandem mass spectrometry has been employed to sequence linear biomolecules e.g., proteins and peptides. However, its application in structural characterization of HS is limited due to the neutral loss of sulfate (SO3) during collisional induced dissociation (CID). In this report, we studied the dissociation patterns of HS disaccharides and demonstrate that the N-sulfate (N-S) bond is especially facile during CID. We identified factors that influence the propensities of such losses from precursor ions and proposed a Free Proton Index (FPI) to help select ions that are able to produce meaningful backbone dissociations. We then investigated the thermodynamics and kinetics of SO3 loss from sulfates that are protonated, deprotonated, and metal-adducted using density functional theory computations. The calculations showed that sulfate loss from a protonated site was much more facile than that from a deprotonated or metal-adducted site. Further, the loss of SO3 from N-sulfate was energetically favored by 3-8 kcal/mol in transition states relative to O-sulfates, making it more prone to this process by a substantial factor. In order to reduce the FPI, representing the number of labile sulfates in HS native chains and oligosaccharides, we developed a series of chemical modifications to selectively replace the N-sulfates of the glucosamine with deuterated acetyl group. These modifications effectively reduced the sulfate density on the HS oligosaccharides and generated considerably more backbone dissociation using on-line LC/tandem MS.

  5. The ammonium sulfate inhibition of human angiogenin.

    PubMed

    Chatzileontiadou, Demetra S M; Tsirkone, Vicky G; Dossi, Kyriaki; Kassouni, Aikaterini G; Liggri, Panagiota G V; Kantsadi, Anastassia L; Stravodimos, George A; Balatsos, Nikolaos A A; Skamnaki, Vassiliki T; Leonidas, Demetres D

    2016-09-01

    In this study, we investigate the inhibition of human angiogenin by ammonium sulfate. The inhibitory potency of ammonium sulfate for human angiogenin (IC50 = 123.5 ± 14.9 mm) is comparable to that previously reported for RNase A (119.0 ± 6.5 mm) and RNase 2 (95.7 ± 9.3 mm). However, analysis of two X-ray crystal structures of human angiogenin in complex with sulfate anions (in acidic and basic pH environments, respectively) indicates an entirely distinct mechanism of inhibition. While ammonium sulfate inhibits the ribonucleolytic activity of RNase A and RNase 2 by binding to the active site of these enzymes, sulfate anions bind only to peripheral substrate anion-binding subsites of human angiogenin, and not to the active site. © 2016 Federation of European Biochemical Societies.

  6. 21 CFR 173.385 - Sodium methyl sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium methyl sulfate. 173.385 Section 173.385... Sodium methyl sulfate. Sodium methyl sulfate may be present in pectin in accordance with the following... subsequent treatment with sodium bicarbonate. (b) It does not exceed 0.1 percent by weight of the pectin. ...

  7. Recalibrating the concentration of Precambrian seawater sulfate

    NASA Astrophysics Data System (ADS)

    Johnston, D. T.; Bradley, A. S.; Hoarfrost, A.; Girguis, P. R.

    2010-12-01

    The isotopic offset between sulfate sulfur and sulfide sulfur (δ34Ssulfate-sulfide) is widely used in the Precambrian as a paleo-indicator of seawater sulfate concentrations. Popularized by experimental work proposing an increase in seawater sulfate at the Archean - Proterozoic boundary, the concept of using a calibrated physiological process (dissimilatory sulfate reduction) to extract environmental information holds the potential to unlock numerous geological questions. To that end, the interpretability of sulfur isotope records relies on the degree to which strict quantitative constraints have been placed on the relationship between sulfate concentrations and sulfate reducing bacteria. Our work serves to extend those constraints. Here we present data from a series of replicate quasi-chemostat microbial reactors, inoculated with marine sediment from Monterey Bay and incubated with artificial seawater ([SO42-]< 5 mM). Our experimental design continuously removes sulfide and allows for systematic tracking of the dependence of δ34Ssulfate-sulfide on seawater sulfate concentration. In addition to expanding the existing δ34S context, we target high-precision multiple sulfur isotope data, which allows for a greater interpretability of both the overall result and its mapping onto environmental records. Further, we use natural abundance and δ18O spiked water within our experiments to assay rates of cellular re-oxidation (within the sulfate reduction pathway) and to constrain natural δ18O effects within these systems. Finally, we use modern molecular biological techniques to track community structure as a function of time and environmental conditions. Together, these data provide an integrated metric with which to interpret complex natural sulfur isotope records.

  8. Metallorganic chemical vapor deposition and atomic layer deposition approaches for the growth of hafnium-based thin films from dialkylamide precursors for advanced CMOS gate stack applications

    NASA Astrophysics Data System (ADS)

    Consiglio, Steven P.

    To continue the rapid progress of the semiconductor industry as described by Moore's Law, the feasibility of new material systems for front end of the line (FEOL) process technologies needs to be investigated, since the currently employed polysilicon/SiO2-based transistor system is reaching its fundamental scaling limits. Revolutionary breakthroughs in complementary-metal-oxide-semiconductor (CMOS) technology were recently announced by Intel Corporation and International Business Machines Corporation (IBM), with both organizations revealing significant progress in the implementation of hafnium-based high-k dielectrics along with metal gates. This announcement was heralded by Gordon Moore as "...the biggest change in transistor technology since the introduction of polysilicon gate MOS transistors in the late 1960s." Accordingly, the study described herein focuses on the growth of Hf-based dielectrics and Hf-based metal gates using chemical vapor-based deposition methods, specifically metallorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD). A family of Hf source complexes that has received much attention recently due to their desirable properties for implementation in wafer scale manufacturing is the Hf dialkylamide precursors. These precursors are room temperature liquids and possess sufficient volatility and desirable decomposition characteristics for both MOCVD and ALD processing. Another benefit of using these sources is the existence of chemically compatible Si dialkylamide sources as co-precursors for use in Hf silicate growth. The first part of this study investigates properties of MOCVD-deposited HfO2 and HfSixOy using dimethylamido Hf and Si precursor sources using a customized MOCVD reactor. The second part of this study involves a study of wet and dry surface pre-treatments for ALD growth of HfO2 using tetrakis(ethylmethylamido)hafnium in a wafer scale manufacturing environment. The third part of this study is an investigation of

  9. Conduction Channel Formation and Dissolution Due to Oxygen Thermophoresis/Diffusion in Hafnium Oxide Memristors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kumar, Suhas; Wang, Ziwen; Huang, Xiaopeng

    Due to the favorable operating power, endurance, speed, and density., transition-metal-oxide memristors, or resistive random-access memory (RRAM) switches, are under intense development for storage-class memory. Their commercial deployment critically depends on predictive compact models based on understanding nanoscale physiocochemical forces, which remains elusive and controversial owing to the difficulties in directly observing atomic motions during resistive switching, Here, using scanning transmission synchrotron X-ray spectromicroscopy to study in situ switching of hafnium oxide memristors, we directly observed the formation of a localized oxygen-deficiency-derived conductive channel surrounded by a low-conductivity ring of excess oxygen. Subsequent thermal annealing homogenized the segregated oxygen, resettingmore » the cells toward their as-grown resistance state. We show that the formation and dissolution of the conduction channel are successfully modeled by radial thermophoresis and Fick diffusion of oxygen atoms driven by Joule heating. This confirmation and quantification of two opposing nanoscale radial forces that affect bipolar memristor switching are important components for any future physics-based compact model for the electronic switching of these devices.« less

  10. Experimental sulfate amendment alters peatland bacterial community structure.

    PubMed

    Strickman, R J S; Fulthorpe, R R; Coleman Wasik, J K; Engstrom, D R; Mitchell, C P J

    2016-10-01

    As part of a long-term, peatland-scale sulfate addition experiment, the impact of varying sulfate deposition on bacterial community responses was assessed using 16S tag encoded pyrosequencing. In three separate areas of the peatland, sulfate manipulations included an eight year quadrupling of atmospheric sulfate deposition (experimental), a 3-year recovery to background deposition following 5years of elevated deposition (recovery), and a control area. Peat concentrations of methylmercury (MeHg), a bioaccumulative neurotoxin, were measured, the production of which is attributable to a growing list of microorganisms, including many sulfate-reducing Deltaproteobacteria. The total bacterial and Deltaproteobacterial community structures in the experimental treatment differed significantly from those in the control and recovery treatments that were either indistinguishable or very similar to one another. Notably, the relatively rapid return (within three years) of bacterial community structure in the recovery treatment to a state similar to the control, demonstrates significant resilience of the peatland bacterial community to changes in atmospheric sulfate deposition. Changes in MeHg accumulation between sulfate treatments correlated with changes in the Deltaproteobacterial community, suggesting that sulfate may affect MeHg production through changes in the community structure of this group. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Sulfation of LH Does Not Affect Intracellular Trafficking

    PubMed Central

    Pearl, Christopher A.; Boime, Irving

    2009-01-01

    LH and FSH are produced by the same gonadotrope cells of the anterior pituitary but differ in their mode of secretion. LH secretion is primarily episodic, or regulated, while FSH secretion is primarily basal, or constitutive. The asparagine (N)-linked oligosaccharides of LH and FSH terminate with sulfate and sialic acid, respectively. TSH also contains sulfated N-linked oligosaccharides and is secreted through the regulated pathway. It has been hypothesized that sulfate plays a role in segregating LH to the regulated pathway. Using a mouse pituitary model, we tested this hypothesis by examining the secretory fate of LH from pituitaries treated with sodium chlorate, a known inhibitor of sulfation. Here we show that mouse LH is sulfated and secreted through the regulated pathway, while FSH is secreted constitutively. LH secretion from chlorate treated pituitaries, which showed complete inhibition of sulfation, was similar to untreated pituitaries. These data suggest that the metabolic role for sulfated N-linked oligosaccharides is not for intracellular trafficking but for the extracellular bioactivity of LH. PMID:19647136

  12. Modeling and minimization of barium sulfate scale

    Treesearch

    Alan W. Rudie; Peter W. Hart

    2006-01-01

    The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using...

  13. Highly effective electronic passivation of silicon surfaces by atomic layer deposited hafnium oxide

    NASA Astrophysics Data System (ADS)

    Cui, Jie; Wan, Yimao; Cui, Yanfeng; Chen, Yifeng; Verlinden, Pierre; Cuevas, Andres

    2017-01-01

    This paper investigates the application of hafnium oxide (HfO2) thin films to crystalline silicon (c-Si) solar cells. Excellent passivation of both n- and p-type crystalline silicon surfaces has been achieved by the application of thin HfO2 films prepared by atomic layer deposition. Effective surface recombination velocities as low as 3.3 and 9.9 cm s-1 have been recorded with 15 nm thick films on n- and p-type 1 Ω cm c-Si, respectively. The surface passivation by HfO2 is activated at 350 °C by a forming gas anneal. Capacitance voltage measurement shows an interface state density of 3.6 × 1010 cm-2 eV-1 and a positive charge density of 5 × 1011 cm-2 on annealed p-type 1 Ω cm c-Si. X-ray diffraction unveils a positive correlation between surface recombination and crystallinity of the HfO2 and a dependence of the crystallinity on both annealing temperature and film thickness. In summary, HfO2 is demonstrated to be an excellent candidate for surface passivation of crystalline silicon solar cells.

  14. A COMPARISON OF EXPERIMENTS AND THREE-DIMENSIONAL ANALYSIS TECHNIQUES. PART I. UNPOISONED UNIFORM SLAB CORE WITH A PARTIALLY INSERTED HAFNIUM ROD

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Renzi, N.E.; Roseberry, R.J.

    >The experimental measurements and nuclear analysis of a uniformly loaded, unpoisoned slab core with a partially insented hafnium rod are described. Comparisons of experimental data with calculated results of the UFO code and flux synthesis techniques are given. It was concluded that one of the flux synthesis techniques and the UFO code are able to predict flux distributions to within approximately 5% of experiment for most cases. An error of approximately 10% was found in the synthesis technique for a channel near the partially inserted rod. The various calculations were able to predict neutron pulsed shutdowns to only approximately 30%.more » (auth)« less

  15. High-energy X-ray detection by hafnium-doped organic-inorganic hybrid scintillators prepared by sol-gel method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sun, Yan; Koshimizu, Masanori, E-mail: koshi@qpc.che.tohoku.ac.jp; Yahaba, Natsuna

    2014-04-28

    With the aim of enhancing the efficiency with which plastic scintillators detect high-energy X-rays, hafnium-doped organic-inorganic hybrid scintillators were fabricated via a sol-gel method. Transmission electron microscopy of sampled material reveals the presence of Hf{sub x}Si{sub 1−x}O{sub 2} nanoparticles, dispersed in a polymer matrix that constitutes the active material of the X-ray detector. With Hf{sub x}Si{sub 1−x}O{sub 2} nanoparticles incorporated in the polymer matrix, the absorption edge and the luminescence wavelength is shifted, which we attribute to Mie scattering. The detection efficiency for 67.4-keV X-rays in a 0.6-mm-thick piece of this material is two times better than the same thicknessmore » of a commercial plastic scintillator-NE142.« less

  16. Identical Origin for Halide and Sulfate Efflorescences on Meteorite Finds and Sulfate Veins in Orgueil

    NASA Technical Reports Server (NTRS)

    Zolensky, M. E.

    2000-01-01

    Halide and sulfate efflorescences are common on meteorite finds, especially those from cold deserts. Meanwhile, the late-stage sulfate veins in Orgueil are universally accepted as having originated by the action of late-stage high fO2 aqueous alteration on an asteroid. I suggest here that these phenomena have essentially the same origin.

  17. Identical Origin for Halide and Sulfate Efflorescences On Meteorite Finds and Sulfate Veins In Orgueil

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.

    1999-01-01

    Halide and sulfate efflorescences are common on meteorite finds, especially those from cold deserts. Meanwhile, the late-stage sulfate veins in Orgueil are universally accepted as having originated by the action of late-stage high fO2 aqueous alteration on an asteroid. I suggest here that these phenomena have essentially the same origin.

  18. Oxygen-Dependent Growth of the Sulfate-Reducing Bacterium Desulfovibrio oxyclinae in Coculture with Marinobacter sp. Strain MB in an Aerated Sulfate-Depleted Chemostat

    PubMed Central

    Sigalevich, Pavel; Cohen, Yehuda

    2000-01-01

    A chemostat coculture of the sulfate-reducing bacterium Desulfovibrio oxyclinae and the facultatively aerobic heterotroph Marinobacter sp. strain MB was grown for 1 week under anaerobic conditions at a dilution rate of 0.05 h−1. It was then exposed to an oxygen flux of 223 μmol min−1 by gassing the growth vessel with 5% O2. Sulfate reduction persisted under these conditions, though the amount of sulfate reduced decreased by 45% compared to the amount reduced during the initial anaerobic mode. After 1 week of growth under these conditions, sulfate was excluded from the incoming medium. The sulfate concentration in the growth vessel decreased exponentially from 4.1 mM to 2.5 μM. The coculture consumed oxygen effectively, and no residual oxygen was detected during either growth mode in which oxygen was supplied. The proportion of D. oxyclinae cells in the coculture as determined by in situ hybridization decreased from 86% under anaerobic conditions to 70% in the microaerobic sulfate-reducing mode and 34% in the microaerobic sulfate-depleted mode. As determined by the most-probable-number (MPN) method, the numbers of viable D. oxyclinae cells during the two microaerobic growth modes decreased compared to the numbers during the anaerobic growth mode. However, there was no significant difference between the MPN values for the two modes when oxygen was supplied. The patterns of consumption of electron donors and acceptors suggested that when oxygen was supplied in the absence of sulfate and thiosulfate, D. oxyclinae performed incomplete aerobic oxidation of lactate to acetate. This is the first observation of oxygen-dependent growth of a sulfate-reducing bacterium in the absence of either sulfate or thiosulfate. Cells harvested during the microaerobic sulfate-depleted stage and exposed to sulfate and thiosulfate in a respiration chamber were capable of anaerobic sulfate and thiosulfate reduction. PMID:11055958

  19. Calcium sulfate crystallization along citrus root channels in a Florida soil exhibiting acid sulfate properties

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Syslo, S.K.; Myhre, D.L.; Harris, W.G.

    1988-02-01

    The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation ismore » attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum can precipitate if the concentrations of calcium and sulfate in the evaporating groundwater exceed the solubility product of gypsum.« less

  20. Thermal Emission Spectroscopy of Sulfates: Possible Hydrous Iron-Sulfate in the Soil at the MER-A Gusev Crater Landing Site

    NASA Technical Reports Server (NTRS)

    Lane, Melissa D.

    2004-01-01

    Sulfates are likely to be present on Mars as indicated by the sulfur abundances measured at the Viking and Pathfinder landing sites (approx. 5-10% by weight SO3) [1-3] and because of Mars strongly oxidizing environment. Telescopic observations of Mars tentatively identified weak sulfate bands in near infrared [4] and thermal infrared [5] data. The currently orbiting midinfrared instruments (TES, THEMIS) and the Mini-TES on the Mars Exploration Rover landers may enable a positive identification [6] and determination of the chemistry of the sulfates. Critically important to the identification of these minerals is the presence of their spectra in a spectral library. There exist approximately 370 sulfate-mineral species [7]. Sulfate minerals occur in volcanic, hydrothermal, evaporitic, and chemical-weathering environments.

  1. Biogenic barite preciptiation at micromolar ambient sulfate

    NASA Astrophysics Data System (ADS)

    Horner, T. J.; Pryer, H. V.; Nielsen, S.; Ricketts, R. D.

    2016-12-01

    Earth's early oceans were essentially devoid of sulfate, yet barium sulfate (barite) deposits are common to ancient sediments. Most explanations for this `barite paradox' overlook biogenic barite precipitation—the dominant vector of particulate barium cycling in modern seawater—as the ancient oceans were presumably strongly undersaturated with respect to barite. We tested whether biogenic barite could indeed precipitate at trace sulfate by examining the particulate multi-element and Ba-isotopic geochemistry of one of the largest trace-sulfate ecosystems on Earth: Lake Superior. Despite exceptional levels of barite undersaturation in Lake Superior, we find unambiguous evidence of biogenic barite precipitation that is correlated with the depths of greatest organic matter remineralization in the water column. The overall pattern of particulate barium cycling in Lake Superior is strikingly similar to that seen in the open ocean, supporting the critical role of particle-associated `microenvironments' that become rich in respired sulfate as protected sites of biogenic barite formation. Our observations offer a microbially-mediated mechanism for barite formation at micromolar ambient sulfate and thus also a potential resolution to the barite paradox in the ancient oceans.

  2. 21 CFR 520.1044c - Gentamicin sulfate soluble powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gentamicin sulfate soluble powder. 520.1044c... Gentamicin sulfate soluble powder. (a) Specifications. Each gram of gentamicin sulfate soluble powder contains gentamicin sulfate equivalent to 16.7, 66.7, or 333.3 milligrams of gentamicin. (b) Sponsor. See...

  3. 21 CFR 520.1044c - Gentamicin sulfate soluble powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate soluble powder. 520.1044c... Gentamicin sulfate soluble powder. (a) Specifications. Each gram of gentamicin sulfate soluble powder contains gentamicin sulfate equivalent to 16.7, 66.7, or 333.3 milligrams of gentamicin. (b) Sponsor. See...

  4. Nitrate reduction in sulfate-reducing bacteria.

    PubMed

    Marietou, Angeliki

    2016-08-01

    Sulfate-reducing bacteria (SRBs) gain their energy by coupling the oxidation of organic substrate to the reduction of sulfate to sulfide. Several SRBs are able to use alternative terminal electron acceptors to sulfate such as nitrate. Nitrate-reducing SRBs have been isolated from a diverse range of environments. In order to be able to understand the significance of nitrate reduction in SRBs, we need to examine the ecology and physiology of the nitrate-reducing SRB isolates. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    NASA Astrophysics Data System (ADS)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  6. Importance of sulfate radical anion formation and chemistry in heterogeneous OH oxidation of sodium methyl sulfate, the smallest organosulfate

    DOE PAGES

    Kwong, Kai Chung; Chim, Man Mei; Davies, James F.; ...

    2018-02-27

    Organosulfates are important organosulfur compounds present in atmospheric particles. While the abundance, composition, and formation mechanisms of organosulfates have been extensively investigated, it remains unclear how they transform and evolve throughout their atmospheric lifetime. To acquire a fundamental understanding of how organosulfates chemically transform in the atmosphere, this study investigates the heterogeneous OH radical-initiated oxidation of sodium methyl sulfate (CH 3SO 4Na) droplets, the smallest organosulfate detected in atmospheric particles, using an aerosol flow tube reactor at a high relative humidity (RH) of 85%. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (direct analysis in real time,more » DART) coupled with a high-resolution mass spectrometer showed that neither functionalization nor fragmentation products are detected. Instead, the ion signal intensity of the bisulfate ion (HSO 4 -) has been found to increase significantly after OH oxidation. We postulate that sodium methyl sulfate tends to fragment into a formaldehyde (CH 2O) and a sulfate radical anion (SO 4 .-) upon OH oxidation. The formaldehyde is likely partitioned back to the gas phase due to its high volatility. The sulfate radical anion, similar to OH radical, can abstract a hydrogen atom from neighboring sodium methyl sulfate to form the bisulfate ion, contributing to the secondary chemistry. Kinetic measurements show that the heterogeneous OH reaction rate constant, k, is (3.79 ± 0.19) × 10 -13cm 3molecule -1s -1 with an effective OH uptake coefficient, γ eff, of 0.17 ± 0.03. While about 40% of sodium methyl sulfate is being oxidized at the maximum OH exposure (1.27 × 10 12molecule cm -3s), only a 3% decrease in particle diameter is observed. This can be attributed to a small fraction of particle mass lost via the formation and volatilization of formaldehyde. Overall, we firstly demonstrate that the heterogeneous OH oxidation of an

  7. Importance of sulfate radical anion formation and chemistry in heterogeneous OH oxidation of sodium methyl sulfate, the smallest organosulfate

    NASA Astrophysics Data System (ADS)

    Chung Kwong, Kai; Chim, Man Mei; Davies, James F.; Wilson, Kevin R.; Nin Chan, Man

    2018-02-01

    Organosulfates are important organosulfur compounds present in atmospheric particles. While the abundance, composition, and formation mechanisms of organosulfates have been extensively investigated, it remains unclear how they transform and evolve throughout their atmospheric lifetime. To acquire a fundamental understanding of how organosulfates chemically transform in the atmosphere, this work investigates the heterogeneous OH radical-initiated oxidation of sodium methyl sulfate (CH3SO4Na) droplets, the smallest organosulfate detected in atmospheric particles, using an aerosol flow tube reactor at a high relative humidity (RH) of 85 %. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (direct analysis in real time, DART) coupled with a high-resolution mass spectrometer showed that neither functionalization nor fragmentation products are detected. Instead, the ion signal intensity of the bisulfate ion (HSO4-) has been found to increase significantly after OH oxidation. We postulate that sodium methyl sulfate tends to fragment into a formaldehyde (CH2O) and a sulfate radical anion (SO4 ṡ -) upon OH oxidation. The formaldehyde is likely partitioned back to the gas phase due to its high volatility. The sulfate radical anion, similar to OH radical, can abstract a hydrogen atom from neighboring sodium methyl sulfate to form the bisulfate ion, contributing to the secondary chemistry. Kinetic measurements show that the heterogeneous OH reaction rate constant, k, is (3.79 ± 0.19) × 10-13 cm3 molecule-1 s-1 with an effective OH uptake coefficient, γeff, of 0.17 ± 0.03. While about 40 % of sodium methyl sulfate is being oxidized at the maximum OH exposure (1.27 × 1012 molecule cm-3 s), only a 3 % decrease in particle diameter is observed. This can be attributed to a small fraction of particle mass lost via the formation and volatilization of formaldehyde. Overall, we firstly demonstrate that the heterogeneous OH oxidation of an

  8. Importance of sulfate radical anion formation and chemistry in heterogeneous OH oxidation of sodium methyl sulfate, the smallest organosulfate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kwong, Kai Chung; Chim, Man Mei; Davies, James F.

    Organosulfates are important organosulfur compounds present in atmospheric particles. While the abundance, composition, and formation mechanisms of organosulfates have been extensively investigated, it remains unclear how they transform and evolve throughout their atmospheric lifetime. To acquire a fundamental understanding of how organosulfates chemically transform in the atmosphere, this study investigates the heterogeneous OH radical-initiated oxidation of sodium methyl sulfate (CH 3SO 4Na) droplets, the smallest organosulfate detected in atmospheric particles, using an aerosol flow tube reactor at a high relative humidity (RH) of 85%. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (direct analysis in real time,more » DART) coupled with a high-resolution mass spectrometer showed that neither functionalization nor fragmentation products are detected. Instead, the ion signal intensity of the bisulfate ion (HSO 4 -) has been found to increase significantly after OH oxidation. We postulate that sodium methyl sulfate tends to fragment into a formaldehyde (CH 2O) and a sulfate radical anion (SO 4 .-) upon OH oxidation. The formaldehyde is likely partitioned back to the gas phase due to its high volatility. The sulfate radical anion, similar to OH radical, can abstract a hydrogen atom from neighboring sodium methyl sulfate to form the bisulfate ion, contributing to the secondary chemistry. Kinetic measurements show that the heterogeneous OH reaction rate constant, k, is (3.79 ± 0.19) × 10 -13cm 3molecule -1s -1 with an effective OH uptake coefficient, γ eff, of 0.17 ± 0.03. While about 40% of sodium methyl sulfate is being oxidized at the maximum OH exposure (1.27 × 10 12molecule cm -3s), only a 3% decrease in particle diameter is observed. This can be attributed to a small fraction of particle mass lost via the formation and volatilization of formaldehyde. Overall, we firstly demonstrate that the heterogeneous OH oxidation of an

  9. Chondroitin-4-sulfation negatively regulates axonal guidance and growth

    PubMed Central

    Wang, Hang; Katagiri, Yasuhiro; McCann, Thomas E.; Unsworth, Edward; Goldsmith, Paul; Yu, Zu-Xi; Tan, Fei; Santiago, Lizzie; Mills, Edward M.; Wang, Yu; Symes, Aviva J.; Geller, Herbert M.

    2008-01-01

    Summary Glycosaminoglycan (GAG) side chains endow extracellular matrix proteoglycans with diversity and complexity based upon the length, composition, and charge distribution of the polysaccharide chain. Using cultured primary neurons, we show that specific sulfation in the GAG chains of chondroitin sulfate (CS) mediates neuronal guidance cues and axonal growth inhibition. Chondroitin-4-sulfate (CS-A), but not chondroitin-6-sulfate (CS-C), exhibits a strong negative guidance cue to mouse cerebellar granule neurons. Enzymatic and gene-based manipulations of 4-sulfation in the GAG side chains alter their ability to direct growing axons. Furthermore, 4-sulfated CS GAG chains are rapidly and significantly increased in regions that do not support axonal regeneration proximal to spinal cord lesions in mice. Thus, our findings provide the evidence showing that specific sulfation along the carbohydrate backbone carries instructions to regulate neuronal function. PMID:18768934

  10. An Efficient Approach to Sulfate Metabolites of Polychlorinated Biphenyls

    PubMed Central

    Li, Xueshu; Parkin, Sean; Duffel, Michael W.; Robertson, Larry W.; Lehmler, Hans-Joachim

    2009-01-01

    Polychlorinated biphenyls (PCBs), a major class of persistent organic pollutants, are metabolized to hydroxylated PCBs. Several hydroxylated PCBs are substrates of cytosolic phase II enzymes, such as phenol and hydroxysteroid (alcohol) sulfotransferases; however, the corresponding sulfation products have not been isolated and characterized. Here we describe a straightforward synthesis of a series of ten PCB sulfate monoesters from the corresponding hydroxylated PCBs. The hydroxylated PCBs were synthesized by coupling chlorinated benzene boronic acids with appropriate brominated (chloro-)anisoles, followed by demethylation with boron tribromide. The hydroxylated PCBs were sulfated with 2,2,2-trichloroethyl chlorosulfate using DMAP as base. Deprotection with zinc powder/ammonium formate yielded the ammonium salts of the desired PCB sulfate monoesters in good yields when the sulfated phenyl ring contained no or one chlorine substituent. However, no PCB sulfate monoesters were isolated when two chlorines were present ortho to the sulfated hydroxyl group. To aid with future quantitative structure activity relationship studies, the structures of two 2,2,2-trichloroethyl-protected PCB sulfates were verified by X-ray diffraction. PMID:19345419

  11. Crystallization of Chicken Egg White Lysozyme from Sulfate Salts

    NASA Technical Reports Server (NTRS)

    Forsythe, Elizabeth; Pusey, Marc

    1998-01-01

    It has been "known" that chicken egg white lysozyme does not crystallize from sulfate, particularly ammonium sulfate, salts, but instead gives amorphous precipitates. This has been the basis of several studies using lysozyme comparing macromolecule crystal nucleation and amorphous precipitation. Recently Ries-Kautt et al (Acta Cryst D50, (1994) 366) have shown that purified isoionic CEWL could be crystallized from low concentrations of sulfate at basic pH, and we subsequently showed that in fact CEWL could be purified in both the tetragonal and orthorhombic forms using ammonium sulfate over the pH range 4.0 to 7.8 (Acta Cryst D53, (1997) 795). We have now extended these observations to include a range of common sulfate salts, specifically sodium, potassium, rubidium, magnesium, and manganese sulfates. In all cases but the manganese sulfates both the familiar tetragonal and orthorhombic forms were obtained, with unit cell dimensions close to those known for the "classic" sodium chloride crystallized forms. Manganese sulfate has only yielded orthorhombic crystals to date. All crystallizations were carried out using low (typically less than or equal to 6 M) salt and high (greater than approximately 90 mg/ml) protein concentrations. As with ammonium sulfate, the tetragonal - orthorhombic phase shift appears to be a function of both the temperature and the protein concentration, with higher temperatures and concentrations favoring the orthorhombic and lower the tetragonal form. The phase change range is somewhat reduced for the sulfate salts, depending upon conditions being typically between approximately 15 - 20 C. Both the magnesium and manganese sulfates gave crystals at salt concentrations over 0.6 M as well, with magnesium sulfate giving a very slowly nucleating and growing hexagonal form. A triclinic crystal form, characterized by aggressively small crystals (typically 0.1 mm in size) has been occasionally obtained from ammonium sulfate. Finally, preliminary spot

  12. Gaseous Sulfate Solubility in Glass: Experimental Method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bliss, Mary

    2013-11-30

    Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature tomore » guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.« less

  13. Metabolic interactions in methanogenic and sulfate-reducing bioreactors.

    PubMed

    Stams, A J M; Plugge, C M; de Bok, F A M; van Houten, B H G W; Lens, P; Dijkman, H; Weijma, J

    2005-01-01

    In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.

  14. Method of increasing the sulfation capacity of alkaline earth sorbents

    DOEpatents

    Shearer, J.A.; Turner, C.B.; Johnson, I.

    1980-03-13

    A system and method for increasing the sulfation capacity of alkaline earth carbonates to scrub sulfur dioxide produced during the fluidized bed combustion of coal in which partially sulfated alkaline earth carbonates are hydrated in a fluidized bed to crack the sulfate coating and convert the alkaline earth oxide to the hydroxide. Subsequent dehydration of the sulfate-hydroxide to a sulfate-oxide particle produces particles having larger pore size, increased porosity, decreased grain size and additional sulfation capacity. A continuous process is disclosed.

  15. Method of increasing the sulfation capacity of alkaline earth sorbents

    DOEpatents

    Shearer, John A.; Turner, Clarence B.; Johnson, Irving

    1982-01-01

    A system and method for increasing the sulfation capacity of alkaline earth carbonates to scrub sulfur dioxide produced during the fluidized bed combustion of coal in which partially sulfated alkaline earth carbonates are hydrated in a fluidized bed to crack the sulfate coating and convert the alkaline earth oxide to the hydroxide. Subsequent dehydration of the sulfate-hydroxide to a sulfate-oxide particle produces particles having larger pore size, increased porosity, decreased grain size and additional sulfation capacity. A continuous process is disclosed.

  16. Sources of sulfate supporting anaerobic metabolism in a contaminated aquifer

    USGS Publications Warehouse

    Ulrich, G.A.; Breit, G.N.; Cozzarelli, I.M.; Suflita, J.M.

    2003-01-01

    Field and laboratory techniques were used to identify the biogeochemical factors affecting sulfate reduction in a shallow, unconsolidated alluvial aquifer contaminated with landfill leachate. Depth profiles of 35S-sulfate reduction rates in aquifer sediments were positively correlated with the concentration of dissolved sulfate. Manipulation of the sulfate concentration in samples revealed a Michaelis-Menten-like relationship with an apparent Km and Vmax of approximately 80 and 0.83 ??M SO4-2??day-1, respectively. The concentration of sulfate in the core of the leachate plume was well below 20 ??M and coincided with very low reduction rates. Thus, the concentration and availability of this anion could limit in situ sulfate-reducing activity. Three sulfate sources were identified, including iron sulfide oxidation, barite dissolution, and advective flux of sulfate. The relative importance of these sources varied with depth in the alluvium. The relatively high concentration of dissolved sulfate at the water table is attributed to the microbial oxidation of iron sulfides in response to fluctuations of the water table. At intermediate depths, barite dissolves in undersaturated pore water containing relatively high concentrations of dissolved barium (???100 ??M) and low concentrations of sulfate. Dissolution is consistent with the surface texture of detrital barite grains in contact with leachate. Laboratory incubations of unamended and barite-amended aquifer slurries supported the field observation of increasing concentrations of barium in solution when sulfate reached low levels. At a deeper highly permeable interval just above the confining bottom layer of the aquifer, sulfate reduction rates were markedly higher than rates at intermediate depths. Sulfate is supplied to this deeper zone by advection of uncontaminated groundwater beneath the landfill. The measured rates of sulfate reduction in the aquifer also correlated with the abundance of accumulated iron sulfide

  17. Efflorescence relative humidity for ammonium sulfate particles.

    PubMed

    Gao, Yonggang; Chen, Shing Bor; Yu, Liya E

    2006-06-22

    The classical homogeneous nucleation theory was employed to calculate the efflorescence relative humidity (ERH) of airborne ammonium sulfate particles with a wide size range (8 nm to 17 microm) at room temperature. The theoretical predictions are in good agreement with the experimentally measured values. When the ammonium sulfate particle is decreased in size, the ERH first decreases, reaches a minimum around 30% for particle diameter equal to about 30 nm, and then increases. It is for the first time that the Kelvin effect is theoretically verified to substantially affect the ERH of ammonium sulfate particles smaller than 30 nm, while the aerosol size is the dominant factor affecting the efflorescent behavior of ammonium sulfate particles larger than 50 nm.

  18. 21 CFR 522.1484 - Neomycin sulfate sterile solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate sterile solution. 522.1484... § 522.1484 Neomycin sulfate sterile solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of neomycin sulfate (equivalent to 35 milligrams of neomycin base).1 1...

  19. 21 CFR 522.1484 - Neomycin sulfate sterile solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate sterile solution. 522.1484... § 522.1484 Neomycin sulfate sterile solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of neomycin sulfate (equivalent to 35 milligrams of neomycin base).1 1...

  20. 21 CFR 522.1484 - Neomycin sulfate sterile solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate sterile solution. 522.1484... § 522.1484 Neomycin sulfate sterile solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of neomycin sulfate (equivalent to 35 milligrams of neomycin base).1 1...

  1. 21 CFR 522.1484 - Neomycin sulfate sterile solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate sterile solution. 522.1484... § 522.1484 Neomycin sulfate sterile solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of neomycin sulfate (equivalent to 35 milligrams of neomycin base).1 1...

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

    DOE PAGES

    Sivan, Orit; Antler, Gilad; Turchyn, Alexandra V.; ...

    2014-09-22

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

  3. Global source attribution of sulfate aerosol and its radiative forcing

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Wang, H.; Smith, S.; Easter, R. C.; Ma, P. L.; Qian, Y.; Li, C.; Yu, H.; Rasch, P. J.

    2017-12-01

    Sulfate is an important aerosol that poses health risks and influences climate. Due to long-range atmospheric transport, local sulfate pollution could result from intercontinental influences, making domestic efforts of improving air quality inefficient. Accurate understanding of source attribution of sulfate and its radiative forcing is important for both regional air quality improvement and global climate mitigation. In this study, for the first time, a sulfur source-tagging capability is implemented in the Community Atmosphere Model (CAM5) to quantify the global source-receptor relationships of sulfate and its direct and indirect radiative forcing (DRF and IRF). Near-surface sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate is primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 20% of sulfate concentrations over North Africa, Russia and Central Asia. Sources from the Middle East account for 20% of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 20% over South Asia in spring. East Asia accounts for about 50% of sulfate over Southeast Asia in winter and autumn, 15% over Russia in summer, and 10% over North America in spring. South Asia contributes to 25% of sulfate over Southeast Asia in spring. Lifetime of aerosols, together with regional export, is found to determine regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with 75% contributed by anthropogenic sulfate and 25% contributed by natural sulfate. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes the most to the total DRF. East Asia has the largest contribution of 20-30% over the Northern Hemisphere mid- and high-latitudes. A 20% perturbation of sulfate and its precursor emissions gives a sulfate IRF of -0.44 W m-2. DMS has the

  4. Diethyl sulfate

    Integrated Risk Information System (IRIS)

    Diethyl sulfate ; CASRN 64 - 67 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  5. Dimethyl sulfate

    Integrated Risk Information System (IRIS)

    Dimethyl sulfate ; CASRN 77 - 78 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  6. A CONSIDERATION OF THE PERMEABILITY OF CARTILAGE TO INORGANIC SULFATE

    PubMed Central

    Campo, Robert D.; Dziewiatkowski, Dominic D.

    1961-01-01

    On the basis of an examination of autoradiograms of knee-joints fixed so as to remove chondroitin sulfate or inorganic sulfate, or to minimize the loss of both, it is suggested that the cartilage is permeable to inorganic sulfate in vivo and in vitro. In vivo and in vitro, almost as rapidly as it enters the cartilage, inorganic sulfate is utilized by the cells in the synthesis of chondroitin sulfate. The net result is a continuing low concentration of inorganic sulfate in the cartilage. PMID:13690307

  7. 21 CFR 529.50 - Amikacin sulfate intrauterine solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amikacin sulfate intrauterine solution. 529.50... Amikacin sulfate intrauterine solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 250 milligrams of amikacin (as the sulfate). (b) Sponsor. See No. 000856 and 059130 in § 510.600(c...

  8. Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins.

    PubMed

    Krichen, Fatma; Volpi, Nicola; Sila, Assaâd; Maccari, Francesca; Mantovani, Veronica; Galeotti, Fabio; Ellouz-Chaabouni, Semia; Bougatef, Ali

    2017-02-01

    Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Polyguluronate sulfate, polymannuronate sulfate, and their oligosaccharides have antithrombin III- and heparin cofactor II-independent anticoagulant activity

    NASA Astrophysics Data System (ADS)

    Zeng, Xuan; Lan, Ying; Zeng, Pengjiao; Guo, Zhihua; Hao, Cui; Zhang, Lijuan

    2017-04-01

    Cardiovascular disease is the leading causes of death. However, the complications can be treated with heparin and heparinoids, such as heparin pentasaccharide Fondaparinux, dermatan sulfate, and PSS made from alginate extracted from brown seaweeds by chemical sulfation. Alginate is composed of a linear backbone of polymannuronate (PM), polyguluronate (PG), and alternate residues of mannuronic acid and guluronic acid. It is unknown if heparin and sulfated PG (PGS)/PM (PMS) have the same or different anticoagulant molecular targets. In the current study, the anticoagulant activities of PGS, PMS, and their oligosaccharides were directly compared to that of heparin, Fondaparinux, and dermatan sulfate by the activated partial thrombinplastin time (aPTT) assay using normal, antithrombin III (ATIII)-deficient, heparin co-factor II (HCII)-deficient, and ATIII- and HCII-double deficient human plasmas. Our results showed that PGS, PMS, and their oligosaccharides had better anticoagulant activity than that of Fondaparinux in all four human plasmas tested. As expected, heparin was the best anticoagulant in normal plasma. Moreover, PGS, PGS6, PGS12, PGS25, PMS6, PMS12, and PMS25 were better anticoagulants than dermatan sulfate in HCII-deficient plasma. Most strikingly, PGS, PGS12, PGS25, PMS6, PMS12, and PMS25 were better anticoagulants than that of heparin in ATIII- and HCII-double deficient human plasma. The results revealed for the first time that sulfated alginate had ATIII- and HCII-independent anticoagulant activities. Therefore, developing PGS and PMS-based anticoagulants might require to discover their major molecular targets and to develop target-specific anticoagulant assays.

  10. Kinetics of sulfate and hydrogen uptake by the thermophilic sulfate-reducing bacteria Thermodesulfobacterium sp. strain JSP and Thermodesulfovibrio sp. strain R1Ha3

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sonne-Hansen, J.; Ahring, B.K.; Westermann, P.

    1999-03-01

    Dissimilatory sulfate reduction and methanogenesis are the main terminal processes in the anaerobic food chain. Both the sulfate-reducing bacteria (SRB) and the methane-producing archaea (MPA) use acetate and hydrogen as substrates and, therefore, compete for common electron donors in sulfate-containing natural environments. Due to a higher affinity for the electron donors acetate and hydrogen, SRB outcompete MPA for these compounds whenever sulfate is present in sufficient concentrations. Half-saturation constants (K{sub m}), maximum uptake rates (V{sub max}), and threshold concentrations for sulfate and hydrogen were determined for two thermophilic sulfate-reducing bacteria (SRB) in an incubation system without headspace. K{sub m} valuesmore » determined for the thermophilic SRB were similar to the constants described for mesophilic SRB isolated from environments with low sulfate concentrations.« less

  11. Sulfates on Mars: TES Observations and Thermal Inertia Data

    NASA Astrophysics Data System (ADS)

    Cooper, C. D.; Mustard, J. F.

    2001-05-01

    The high resolution thermal emission spectra returned by the TES spectrometer on the MGS spacecraft have allowed the mapping of a variety of minerals and rock types by different sets of researchers. Recently, we have used a linear deconvolution approach to compare sulfate-palagonite soil mixtures created in the laboratory with Martian surface spectra. This approach showed that a number of areas on Mars have spectral properties that match those of sulfate-cemented soils (but neither loose powder mixtures of sulfates and soils nor sand-sized grains of disaggregated crusted soils). These features do not appear to be caused by atmospheric or instrumental effects and are thus believed to be related to surface composition and texture. The distribution and physical state of sulfate are important pieces of information for interpreting surface processes on Mars. A number of different mechanisms could have deposited sulfate in surface layers. Some of these include evaporation of standing bodies of water, aerosol deposition of volcanic gases, hydrothermal alteration from groundwater, and in situ interaction between the atmosphere and soil. The areas on Mars with cemented sulfate signatures are spread across a wide range of elevations and are generally large in spatial scale. Some of the areas are associated with volcanic regions, but many are in dark red plains that have previously been interpreted as duricrust deposits. Our current work compares the distribution of sulfate-cemented soils as mapped by the spectral deconvolution approach with thermal inertia maps produced from both Viking and MGS-TES. Duricrust regions, interpreted from intermediate thermal inertia values, are large regions thought to be sulfate-cemented soils similar to coherent, sulfate-rich materials seen at the Viking lander sites. Our observations of apparent regions of cemented sulfate are also large in spatial extent. This scale information is important for evaluating formation mechanisms for the

  12. Hydrazine Sulfate (PDQ®)—Patient Version

    Cancer.gov

    Hydrazine sulfate has shown no anticancer activity in randomized clinical trials. It was reported in some clinical trials to be helpful in treating poor appetite and weight loss due to cancer. Learn more about hydrazine sulfate as a treatment for people with cancer in this expert-reviewed summary.

  13. Integrated Spectroscopic Studies of Hydrous Sulfate Minerals

    NASA Technical Reports Server (NTRS)

    Dyar, M. D.; Lane, M. D.; Bishop, J. L.; OConnor, V.; Cloutis, E.; Hiroi, T.

    2005-01-01

    Sulfate minerals have been identified in Martian meteorites and on Mars using a suite of instruments aboard the MER rovers. These results have confirmed previous groundbased observations and orbital measurements that suggested their presence. The orbiting OMEGA instrument on Mars Express is also finding evidence for sulfate. In order to better interpret remote-sensing data, we present here the results of a coordinated visible/near infrared (VNIR) reflectance, Moussbauer (MB), and thermal emittance study of wellcharacterized hydrous sulfate minerals.

  14. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

  15. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

  16. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

  17. 21 CFR 172.270 - Sulfated butyl oleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... edible vegetable oil using 1-butanol. Following sulfation, the reaction mixture is washed with water and neutralized with aqueous sodium or potassium hydroxide. Prior to sulfation, the butyl oleate reaction mixture...

  18. Development of affinity-based delivery of NGF from a chondroitin sulfate biomaterial.

    PubMed

    Butterfield, Karen Chao; Conovaloff, Aaron W; Panitch, Alyssa

    2011-01-01

    Chondroitin sulfate is a major component of the extracellular matrix in both the central and peripheral nervous systems. Chondroitin sulfate is upregulated at injury, thus methods to promote neurite extension through chondroitin sulfate-rich matrices and synthetic scaffolds are needed. We describe the use of both chondroitin sulfate and a novel chondroitin sulfate-binding peptide to control the release of nerve growth factor. Interestingly, the novel chondroitin sulfate-binding peptide enhances the controlled release properties of the chondroitin sulfate gels. While introduction of chondroitin sulfate into a scaffold inhibits primary cortical outgrowth, the combination of chondroitin sulfate, chondroitin sulfate-binding peptide and nerve growth factor promotes primary cortical neurite outgrowth in chondroitin sulfate gels.

  19. 40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

  20. 40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate obtained from...

  1. 40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

  2. 40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

  3. 40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate obtained from...

  4. Xyloside-primed Chondroitin Sulfate/Dermatan Sulfate from Breast Carcinoma Cells with a Defined Disaccharide Composition Has Cytotoxic Effects in Vitro.

    PubMed

    Persson, Andrea; Tykesson, Emil; Westergren-Thorsson, Gunilla; Malmström, Anders; Ellervik, Ulf; Mani, Katrin

    2016-07-08

    We previously reported that the xyloside 2-(6-hydroxynaphthyl) β-d-xylopyranoside (XylNapOH), in contrast to 2-naphthyl β-d-xylopyranoside (XylNap), specifically reduces tumor growth both in vitro and in vivo Although there are indications that this could be mediated by the xyloside-primed glycosaminoglycans (GAGs) and that these differ in composition depending on xyloside and cell type, detailed knowledge regarding a structure-function relationship is lacking. In this study we isolated XylNapOH- and XylNap-primed GAGs from a breast carcinoma cell line, HCC70, and a breast fibroblast cell line, CCD-1095Sk, and demonstrated that both XylNapOH- and XylNap-primed chondroitin sulfate/dermatan sulfate GAGs derived from HCC70 cells had a cytotoxic effect on HCC70 cells and CCD-1095Sk cells. The cytotoxic effect appeared to be mediated by induction of apoptosis and was inhibited in a concentration-dependent manner by the XylNap-primed heparan sulfate GAGs. In contrast, neither the chondroitin sulfate/dermatan sulfate nor the heparan sulfate derived from CCD-1095Sk cells primed on XylNapOH or XylNap had any effect on the growth of HCC70 cells or CCD-105Sk cells. These observations were related to the disaccharide composition of the XylNapOH- and XylNap-primed GAGs, which differed between the two cell lines but was similar when the GAGs were derived from the same cell line. To our knowledge this is the first report on cytotoxic effects mediated by chondroitin sulfate/dermatan sulfate. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Determining Oxygen Isotopic Fractionation between the ferrous sulfate, melanterite, and aqueous sulfate

    NASA Astrophysics Data System (ADS)

    Shulaker, D. Z.; Kohl, I.; Coleman, M. L.

    2011-12-01

    Studying regions on Earth that are analogous to Mars serve as case studies for studying astrobiology and planetary surface rock formation processes. Rio Tinto, Spain is very rich in iron sulfates, and has an environment that is possibly very similar to the former environment on Mars. Certain bacteria play significant roles in accelerating pyrite oxidation rates, the products of which contribute to the formation of ferrous sulfates, such as melanterite. During mineral crystallization in an aqueous solution, there are systematic isotopic differences between dissolved species and solid phases. Quantifying this fractionation enables isotopic analysis to be used to trace the original isotopic signature of the dissolved species. Isotope fractionation has been determined for minerals such as gypsum and epsomite, and from these results and theoretical predictions, it is expected that melanterite, a mineral potentially found on Mars, would be more enriched in oxygen-18 relative to the aqueous solution from which it crystallized.Thus, determining the oxygen-18 isotopic fractionation between melanterite and dissolved sulfate has many potential benefits for understanding surface processes on Mars and its past environment. To investigate the oxygen isotope fractionation for melanterite, acidic aqueous solutions saturated with dissolved hydrated ferrous sulfate were evaporated at 25 deg C and 40 deg C and under different conditions to induce different evaporation rates. During evaporation, the aqueous solution and crystallized melanterite were sampled at different stages. Oxygen-18 isotopic compositions were then measured. However, the fractionations observed in the experiments were opposite from predictions. At 25 deg C without enhanced evaporation, the dissolved sulfate was +5.5 per mil relative to the solid, while at 40 deg C it was +4.3 per mil. With enhanced evaporation, fractionation was +2.1 per mil, while at 40 deg C it was +3.6 per mil. In addition, at 40 deg C

  6. ROLE OF TYROSINE-SULFATED PROTEINS IN RETINAL STRUCTURE AND FUNCTION

    PubMed Central

    Kanan, Y.; Al-Ubaidi, M.R.

    2014-01-01

    The extracellular matrix (ECM) plays a significant role in cellular and retinal health. The study of retinal tyrosine-sulfated proteins is an important first step toward understanding the role of ECM in retinal health and diseases. These secreted proteins are members of the retinal ECM. Tyrosine sulfation was shown to be necessary for the development of proper retinal structure and function. The importance of tyrosine sulfation is further demonstrated by the evolutionary presence of tyrosylprotein sulfotransferases, enzymes that catalyze proteins’ tyrosine sulfation, and the compensatory abilities of these enzymes. Research has identified four tyrosine-sulfated retinal proteins: fibulin 2, vitronectin, complement factor H (CFH), and opticin. Vitronectin and CFH regulate the activation of the complement system and are involved in the etiology of some cases of age-related macular degeneration. Analysis of the role of tyrosine sulfation in fibulin function showed that sulfation influences the protein's ability to regulate growth and migration. Although opticin was recently shown to exhibit anti-angiogenic properties, it is not yet determined what role sulfation plays in that function. Future studies focusing on identifying all of the tyrosine-sulfated retinal proteins would be instrumental in determining the impact of sulfation on retinal protein function in retinal homeostasis and diseases. PMID:25819460

  7. A novel chondroitin sulfate hydrogel for nerve repair

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron William

    Brachial plexus injuries affect numerous patients every year, with very debilitating results. The majority of these cases are very severe, and involve damage to the nerve roots. To date, repair strategies for these injuries address only gross tissue damage, but do not supply cells with adequate regeneration signals. As a result, functional recovery is often severely lacking. Therefore, a chondroitin sulfate hydrogel that delivers neurotrophic signals to damaged neurons is proposed as a scaffold to support nerve root regeneration. Capillary electrophoresis studies revealed that chondroitin sulfate can physically bind with a variety of neurotrophic factors, and cultures of chick dorsal root ganglia demonstrated robust neurite outgrowth in chondroitin sulfate hydrogels. Outgrowth in chondroitin sulfate gels was greater than that observed in control gels of hyaluronic acid. Furthermore, the chondroitin sulfate hydrogel's binding activity with nerve growth factor could be enhanced by incorporation of a synthetic bioactive peptide, as revealed by fluorescence recovery after photobleaching. This enhanced binding was observed only in chondroitin sulfate gels, and not in hyaluronic acid control gels. This enhanced binding activity resulted in enhanced dorsal root ganglion neurite outgrowth in chondroitin sulfate gels. Finally, the growth of regenerating dorsal root ganglia in these gels was imaged using label-free coherent anti-Stokes scattering microscopy. This technique generated detailed, high-quality images of live dorsal root ganglion neurites, which were comparable to fixed, F-actin-stained samples. Taken together, these results demonstrate the viability of this chondroitin sulfate hydrogel to serve as an effective implantable scaffold to aid in nerve root regeneration.

  8. Barium Sulfate

    MedlinePlus

    ... and intestine using x-rays or computed tomography (CAT scan, CT scan; a type of body scan that uses a ... be clearly seen by x-ray examination or CT scan. ... more times before an x-ray examination or CT scan.If you are using a barium sulfate enema, ...

  9. 21 CFR 182.8997 - Zinc sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Zinc sulfate. 182.8997 Section 182.8997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product...

  10. 21 CFR 182.8997 - Zinc sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Zinc sulfate. 182.8997 Section 182.8997 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product...

  11. The Regulation of Steroid Action by Sulfation and Desulfation

    PubMed Central

    Mueller, Jonathan W.; Gilligan, Lorna C.; Idkowiak, Jan; Arlt, Wiebke

    2015-01-01

    Steroid sulfation and desulfation are fundamental pathways vital for a functional vertebrate endocrine system. After biosynthesis, hydrophobic steroids are sulfated to expedite circulatory transit. Target cells express transmembrane organic anion-transporting polypeptides that facilitate cellular uptake of sulfated steroids. Once intracellular, sulfatases hydrolyze these steroid sulfate esters to their unconjugated, and usually active, forms. Because most steroids can be sulfated, including cholesterol, pregnenolone, dehydroepiandrosterone, and estrone, understanding the function, tissue distribution, and regulation of sulfation and desulfation processes provides significant insights into normal endocrine function. Not surprisingly, dysregulation of these pathways is associated with numerous pathologies, including steroid-dependent cancers, polycystic ovary syndrome, and X-linked ichthyosis. Here we provide a comprehensive examination of our current knowledge of endocrine-related sulfation and desulfation pathways. We describe the interplay between sulfatases and sulfotransferases, showing how their expression and regulation influences steroid action. Furthermore, we address the role that organic anion-transporting polypeptides play in regulating intracellular steroid concentrations and how their expression patterns influence many pathologies, especially cancer. Finally, the recent advances in pharmacologically targeting steroidogenic pathways will be examined. PMID:26213785

  12. Modeling sulfate reduction in methane hydrate-bearing continental margin sediments: Does a sulfate-methane transition require anaerobic oxidation of methane?

    USGS Publications Warehouse

    Malinverno, A.; Pohlman, J.W.

    2011-01-01

    The sulfate-methane transition (SMT), a biogeochemical zone where sulfate and methane are metabolized, is commonly observed at shallow depths (1-30 mbsf) in methane-bearing marine sediments. Two processes consume sulfate at and above the SMT, anaerobic oxidation of methane (AOM) and organoclastic sulfate reduction (OSR). Differentiating the relative contribution of each process is critical to estimate methane flux into the SMT, which, in turn, is necessary to predict deeper occurrences of gas hydrates in continental margin sediments. To evaluate the relative importance of these two sulfate reduction pathways, we developed a diagenetic model to compute the pore water concentrations of sulfate, methane, and dissolved inorganic carbon (DIC). By separately tracking DIC containing 12C and 13C, the model also computes ??13C-DIC values. The model reproduces common observations from methane-rich sediments: a well-defined SMT with no methane above and no sulfate below and a ??13C-DIC minimum at the SMT. The model also highlights the role of upward diffusing 13C-enriched DIC in contributing to the carbon isotope mass balance of DIC. A combination of OSR and AOM, each consuming similar amounts of sulfate, matches observations from Site U1325 (Integrated Ocean Drilling Program Expedition 311, northern Cascadia margin). Without AOM, methane diffuses above the SMT, which contradicts existing field data. The modeling results are generalized with a dimensional analysis to the range of SMT depths and sedimentation rates typical of continental margins. The modeling shows that AOM must be active to establish an SMT wherein methane is quantitatively consumed and the ??13C-DIC minimum occurs. The presence of an SMT generally requires active AOM. Copyright 2011 by the American Geophysical Union.

  13. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

  14. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

  15. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327) are...

  16. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327) are...

  17. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

  18. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

  19. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327) are...

  20. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327) are...

  1. AnSBBR applied to organic matter and sulfate removal: interaction effect between feed strategy and COD/sulfate ratio.

    PubMed

    Friedl, Gregor F; Mockaitis, Gustavo; Rodrigues, José A D; Ratusznei, Suzana M; Zaiat, Marcelo; Foresti, Eugênio

    2009-10-01

    A mechanically stirred anaerobic sequencing batch reactor containing anaerobic biomass immobilized on polyurethane foam cubes, treating low-strength synthetic wastewater (500 mg COD L(-1)), was operated under different operational conditions to assess the removal of organic matter and sulfate. These conditions were related to fill time, defined by the following feed strategies: batch mode of 10 min, fed-batch mode of 3 h and fed-batch mode of 6 h, and COD/[SO(4)(2-)] ratios of 1.34, 0.67, and 0.34 defined by organic matter concentration of 500 mg COD L(-1) and sulfate concentrations of 373, 746, and 1,493 mg SO(4)(2-) L(-1) in the influent. Thus, nine assays were performed to investigate the influence of each of these parameters, as well as the interaction effect, on the performance of the system. The reactor operated with agitation of 400 rpm, total volume of 4.0 L, and treated 2.0 L synthetic wastewater in 8-h cycles at 30 +/- 1 degrees C. During all assays, the reactor showed operational stability in relation to the monitored variables such as COD, sulfate, sulfide, sulfite, volatile acids, bicarbonate alkalinity, and solids, thus demonstrating the potential to apply this technology to the combined removal of organic matter and sulfate. In general, the results showed that the 3-h fed-batch operation with a COD/[SO(4)(2-)] ratio of 0.34 presented the best conditions for organic matter removal (89%). The best efficiency for sulfate removal (71%) was accomplished during the assay with a COD/[SO(4)(2-)] ratio of 1.34 and a fill time of 6 h. It was also observed that as fill time and sulfate concentration in the influent increased, the ratio between removed sulfate load and removed organic load also increased. However, it should be pointed out that the aim of this study was not to optimize the removal of organic matter and sulfate, but rather to analyze the behavior of the reactor during the different feed strategies and applied COD/[SO(4)(2-)] ratios, and mainly to

  2. Measurement and Simulation of Thermal Conductivity of Hafnium-Aluminum Thermal Neutron Absorber Material

    DOE PAGES

    Guillen, Donna Post; Harris, William H.

    2016-05-11

    A metal matrix composite (MMC) material comprised of hafnium aluminide (Al3Hf) intermetallic particles in an aluminum matrix has been identified as a promising material for fast-flux irradiation testing applications. This material can filter thermal neutrons while simultaneously providing high rates of conductive cooling for experiment capsules. Our purpose is to investigate effects of Hf-Al material composition and neutron irradiation on thermophysical properties, which were measured before and after irradiation. When performing differential scanning calorimetry (DSC) on the irradiated specimens, a large exotherm corresponding to material annealment was observed. Thus, a test procedure was developed to perform DSC and laser flashmore » analysis (LFA) to obtain the specific heat and thermal diffusivity of pre- and post-annealment specimens. This paper presents the thermal properties for three states of the MMC material: (1) unirradiated, (2) as-irradiated, and (3) irradiated and annealed. Microstructure-property relationships were obtained for the thermal conductivity. These relationships are useful for designing components from this material to operate in irradiation environments. Furthermore, the ability of this material to effectively conduct heat as a function of temperature, volume fraction Al 3Hf, radiation damage and annealing is assessed using the MOOSE suite of computational tools.« less

  3. Ferroelectric transistors with monolayer molybdenum disulfide and ultra-thin aluminum-doped hafnium oxide

    NASA Astrophysics Data System (ADS)

    Yap, Wui Chung; Jiang, Hao; Liu, Jialun; Xia, Qiangfei; Zhu, Wenjuan

    2017-07-01

    In this letter, we demonstrate ferroelectric memory devices with monolayer molybdenum disulfide (MoS2) as the channel material and aluminum (Al)-doped hafnium oxide (HfO2) as the ferroelectric gate dielectric. Metal-ferroelectric-metal capacitors with 16 nm thick Al-doped HfO2 are fabricated, and a remnant polarization of 3 μC/cm2 under a program/erase voltage of 5 V is observed. The capability of potential 10 years data retention was estimated using extrapolation of the experimental data. Ferroelectric transistors based on embedded ferroelectric HfO2 and MoS2 grown by chemical vapor deposition are fabricated. Clockwise hysteresis is observed at low program/erase voltages due to slow bulk traps located near the 2D/dielectric interface, while counterclockwise hysteresis is observed at high program/erase voltages due to ferroelectric polarization. In addition, the endurances of the devices are tested, and the effects associated with ferroelectric materials, such as the wake-up effect and polarization fatigue, are observed. Reliable writing/reading in MoS2/Al-doped HfO2 ferroelectric transistors over 2 × 104 cycles is achieved. This research can potentially lead to advances of two-dimensional (2D) materials in low-power logic and memory applications.

  4. Theoretical study on the reactivity of sulfate species with hydrocarbons

    USGS Publications Warehouse

    Ma, Q.; Ellis, G.S.; Amrani, A.; Zhang, T.; Tang, Y.

    2008-01-01

    The abiotic, thermochemically controlled reduction of sulfate to hydrogen sulfide coupled with the oxidation of hydrocarbons, is termed thermochemical sulfate reduction (TSR), and is an important alteration process that affects petroleum accumulations in nature. Although TSR is commonly observed in high-temperature carbonate reservoirs, it has proven difficult to simulate in the laboratory under conditions resembling nature. The present study was designed to evaluate the relative reactivities of various sulfate species in order to provide greater insight into the mechanism of TSR and potentially to fill the gap between laboratory experimental data and geological observations. Accordingly, quantum mechanics density functional theory (DFT) was used to determine the activation energy required to reach a potential transition state for various aqueous systems involving simple hydrocarbons and different sulfate species. The entire reaction process that results in the reduction of sulfate to sulfide is far too complex to be modeled entirely; therefore, we examined what is believed to be the rate limiting step, namely, the reduction of sulfate S(VI) to sulfite S(IV). The results of the study show that water-solvated sulfate anions SO42 - are very stable due to their symmetrical molecular structure and spherical electronic distributions. Consequently, in the absence of catalysis, the reactivity of SO42 - is expected to be extremely low. However, both the protonation of sulfate to form bisulfate anions (HSO4-) and the formation of metal-sulfate contact ion-pairs could effectively destabilize the sulfate molecular structure, thereby making it more reactive. Previous reports of experimental simulations of TSR generally have involved the use of acidic solutions that contain elevated concentrations of HSO4- relative to SO42 -. However, in formation waters typically encountered in petroleum reservoirs, the concentration of HSO4- is likely to be significantly lower than the levels

  5. Theoretical study on the reactivity of sulfate species with hydrocarbons

    NASA Astrophysics Data System (ADS)

    Ma, Qisheng; Ellis, Geoffrey S.; Amrani, Alon; Zhang, Tongwei; Tang, Yongchun

    2008-09-01

    The abiotic, thermochemically controlled reduction of sulfate to hydrogen sulfide coupled with the oxidation of hydrocarbons, is termed thermochemical sulfate reduction (TSR), and is an important alteration process that affects petroleum accumulations in nature. Although TSR is commonly observed in high-temperature carbonate reservoirs, it has proven difficult to simulate in the laboratory under conditions resembling nature. The present study was designed to evaluate the relative reactivities of various sulfate species in order to provide greater insight into the mechanism of TSR and potentially to fill the gap between laboratory experimental data and geological observations. Accordingly, quantum mechanics density functional theory (DFT) was used to determine the activation energy required to reach a potential transition state for various aqueous systems involving simple hydrocarbons and different sulfate species. The entire reaction process that results in the reduction of sulfate to sulfide is far too complex to be modeled entirely; therefore, we examined what is believed to be the rate limiting step, namely, the reduction of sulfate S(VI) to sulfite S(IV). The results of the study show that water-solvated sulfate anions SO42- are very stable due to their symmetrical molecular structure and spherical electronic distributions. Consequently, in the absence of catalysis, the reactivity of SO42- is expected to be extremely low. However, both the protonation of sulfate to form bisulfate anions ( HSO4-) and the formation of metal-sulfate contact ion-pairs could effectively destabilize the sulfate molecular structure, thereby making it more reactive. Previous reports of experimental simulations of TSR generally have involved the use of acidic solutions that contain elevated concentrations of HSO4- relative to SO42-. However, in formation waters typically encountered in petroleum reservoirs, the concentration of HSO4- is likely to be significantly lower than the levels

  6. Heparan Sulfate and Chondroitin Sulfate Glycosaminoglycans Are Targeted by Bleomycin in Cancer Cells.

    PubMed

    Li, Xiulian; Lan, Ying; He, Yanli; Liu, Yong; Luo, Heng; Yu, Haibo; Song, Ni; Ren, Sumei; Liu, Tianwei; Hao, Cui; Guo, Yunliang; Zhang, Lijuan

    2017-01-01

    Bleomycin is a clinically used anti-cancer drug that produces DNA breaks once inside of cells. However, bleomycin is a positively charged molecule and cannot get inside of cells by free diffusion. We previously reported that the cell surface negatively charged glycosaminoglycans (GAGs) may be involved in the cellular uptake of bleomycin. We also observed that a class of positively charged small molecules has Golgi localization once inside of the cells. We therefore hypothesized that bleomycin might perturb Golgi-operated GAG biosynthesis. We used stable isotope labeling coupled with LC/MS analysis of GAG disaccharides simultaneously from bleomycin-treated and non-treated cancer cells. To further understand the cytotoxicity of bleomycin and its relationship to GAGs, we used sodium chlorate to inhibit GAG sulfation and commercially available GAGs to compete for cell surface GAG/bleomycin interactions in seven cell lines including CHO745 defective in both heparan sulfate and chondroitin sulfate biosynthesis. we discovered that heparan sulfate GAG was significantly undersulfated and the quantity and disaccharide compositions of GAGs were changed in bleomycin-treated cells in a concentration- and time-dependent manner. We revealed that bleomycin-induced cytotoxicity was directly related to cell surface GAGs. GAGs were targeted by bleomycin both at cell surface and at Golgi. Thus, GAGs might be the biological relevant molecules that might be related to the bleomycin-induced fibrosis in certain cancer patients, a severe side effect with largely unknown molecular mechanism. © 2017 The Author(s). Published by S. Karger AG, Basel.

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

    NASA Astrophysics Data System (ADS)

    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

  8. Olivine Weathering aud Sulfate Formation Under Cryogenic Conditions

    NASA Technical Reports Server (NTRS)

    Niles, Paul B.; Golden, D. C.; Michalski, J.

    2013-01-01

    High resolution photography and spectroscopy of the martian surface (MOC, HiRISE) from orbit has revolutionized our view of Mars with one of the most important discoveries being wide-spread layered sedimentary deposits associated with sulfate minerals across the low to mid latitude regions of Mars. The mechanism for sulfate formation on Mars has been frequently attributed to playa-like evaporative environments under prolonged warm conditions. An alternate view of the ancient martian climate contends that prolonged warm temperatures were never present and that the atmosphere and climate has been similar to modern conditions throughout most of its history. This view has had a difficult time explaining the sedimentary history of Mars and in particular the presence of sulfate minerals which seemingly need more water. We suggest here that mixtures of atmospheric aerosols, ice, and dust have the potential for creating small films of cryo-concentrated acidic solutions that may represent an important unexamined environment for understanding weathering processes on Mars. This study seeks to test whether sulfate formation may be possible at temperatures well below 0degC in water limited environments removing the need for prolonged warm periods to form sulfates on early Mars. To test this idea we performed laboratory experiments to simulate weathering of mafic minerals under Mars-like conditions. The weathering rates measured in this study suggest that fine grained olivine on Mars would weather into sulfate minerals in short time periods if they are exposed to H2SO4 aerosols at temperatures at or above -40degC. In this system, the strength of the acidic solution is maximized through eutectic freezing in an environment where the silicate minerals are extremely fine grained and have high surface areas. This provides an ideal environment despite the very low temperatures. On Mars the presence of large deposits of mixed ice and dust is undisputed. The presence of substantial

  9. METHOD OF INHIBITING CORROSION IN URANYL SULFATE SOLUTIONS

    DOEpatents

    Bohlmann, E.G.; Griess, J.C. Jr.

    1960-08-23

    A method is given for treating a uranyl sulfate solution to inhibit the corrosiveness of the solution and elevate the phase separation temperature of the solution. Lithium sulfate is added to the solution in an amount ranging from 0.25 to 1.3 times the uranyl sulfate concentration. The corrosiveness of the solution with respect to stainless steel is substantially decreased by this means. This treatment also serves to raise the phase separation temperature of the solution (above 250 deg C), at which time the uranyl sulfate solution separates into two liquid phases of unequal uranium concentration and thus becomes unsuitable as nuclear reactor fuel.

  10. Annual sulfate budgets for Dutch lowland peat polders: The soil is a major sulfate source through peat and pyrite oxidation

    NASA Astrophysics Data System (ADS)

    Vermaat, Jan E.; Harmsen, Joop; Hellmann, Fritz A.; van der Geest, Harm G.; de Klein, Jeroen J. M.; Kosten, Sarian; Smolders, Alfons J. P.; Verhoeven, Jos T. A.; Mes, Ron G.; Ouboter, Maarten

    2016-02-01

    Annual sulfate mass balances have been constructed for four low-lying peat polders in the Netherlands, to resolve the origin of high sulfate concentrations in surface water, which is considered a water quality problem, as indicated amongst others by the absence of sensitive water plant species. Potential limitation of these plants to areas with low sulfate was analyzed with a spatial match-up of two large databases. The peat polders are generally used for dairy farming or nature conservation, and have considerable areas of shallow surface water (mean 16%, range 6-43%). As a consequence of continuous drainage, the peat in these polders mineralizes causing subsidence rates generally ranging between 2 and 10 mm y-1. Together with pyrite oxidation, this peat mineralization the most important internal source of sulfate, providing an estimated 96 kg SO4 ha-1 mm-1 subsidence y-1. External sources are precipitation and water supplied during summer to compensate for water shortage, but these were found to be minor compared to internal release. The most important output flux is discharge of excess surface water during autumn and winter. If only external fluxes in and out of a polder are evaluated, inputs average 37 ± 9 and exports 169 ± 17 kg S ha-1 y-1. During summer, when evapotranspiration exceeds rainfall, sulfate accumulates in the unsaturated zone, to be flushed away and drained off during the wet autumn and winter. In some polders, upward seepage from early Holocene, brackish sediments can be a source of sulfate. Peat polders export sulfate to the regional water system and the sea during winter drainage. The available sulfate probably only plays a minor role in the oxidation of peat: we estimate that this is less than 10% whereas aerobic mineralization is the most important. Most surface waters in these polders have high sulfate concentrations, which generally decline during the growing season when aquatic sediments are a sink. In the sediment, this sulfur is

  11. In vivo contribution of amino acid sulfur to cartilage proteoglycan sulfation

    PubMed Central

    Pecora, Fabio; Gualeni, Benedetta; Forlino, Antonella; Superti-Furga, Andrea; Tenni, Ruggero; Cetta, Giuseppe; Rossi, Antonio

    2006-01-01

    Cytoplasmic sulfate for sulfation reactions may be derived either from extracellular fluids or from catabolism of sulfur-containing amino acids and other thiols. In vitro studies have pointed out the potential relevance of sulfur-containing amino acids as sources for sulfation when extracellular sulfate concentration is low or when its transport is impaired such as in DTDST [DTD (diastrophic dysplasia) sulfate transporter] chondrodysplasias. In the present study, we have considered the contribution of cysteine and cysteine derivatives to in vivo macromolecular sulfation of cartilage by using the mouse model of DTD we have recently generated [Forlino, Piazza, Tiveron, Della Torre, Tatangelo, Bonafe, Gualeni, Romano, Pecora, Superti-Furga et al. (2005) Hum. Mol. Genet. 14, 859–871]. By intraperitoneal injection of [35S]cysteine in wild-type and mutant mice and determination of the specific activity of the chondroitin 4-sulfated disaccharide in cartilage, we demonstrated that the pathway by which sulfate is recruited from the intracellular oxidation of thiols is active in vivo. To check whether cysteine derivatives play a role, sulfation of cartilage proteoglycans was measured after treatment for 1 week of newborn mutant and wild-type mice with hypodermic NAC (N-acetyl-L-cysteine). The relative amount of sulfated disaccharides increased in mutant mice treated with NAC compared with the placebo group, indicating an increase in proteoglycan sulfation due to NAC catabolism, although pharmacokinetic studies demonstrated that the drug was rapidly removed from the bloodstream. In conclusion, cysteine contribution to cartilage proteoglycan sulfation in vivo is minimal under physiological conditions even if extracellular sulfate availability is low; however, the contribution of thiols to sulfation becomes significant by increasing their plasma concentration. PMID:16719839

  12. Selenium inhibits sulfate-mediated methylmercury production in rice paddy soil.

    PubMed

    Wang, Yong-Jie; Dang, Fei; Zhao, Jia-Ting; Zhong, Huan

    2016-06-01

    There is increasing interest in understanding factors controlling methylmercury (MeHg) production in mercury-contaminated rice paddy soil. Sulfate has been reported to affect MeHg biogeochemistry under anoxic conditions, and recent studies revealed that selenium (Se) could evidently reduce MeHg production in paddy soil. However, the controls of sulfate and Se on net MeHg production in paddy soil under fluctuating redox conditions remain largely unknown. Microcosm experiments were conducted to explore the effects of sulfate and Se on net MeHg production in rice paddy soil. Soil was added with 0-960 mg/kg sulfate, in the presence or absence of 3.0 mg/kg selenium (selenite or selenate), and incubated under anoxic (40 days) or suboxic conditions (5 days), simulating fluctuating redox conditions in rice paddy field. Sulfate addition moderately affected soil MeHg concentrations under anoxic conditions, while reoxidation resulted in evidently higher (18-40%) MeHg levels in sulfate amended soils than the control. The observed changes in net MeHg production were related to dynamics of sulfate and iron. However, Se could inhibit sulfate-mediated MeHg production in the soils: Se addition largely reduced net MeHg production in the soils (23-86%, compared to the control), despite of sulfate addition. Similarly, results of the pot experiments (i.e., rice cultivation in amended soils) indicated that soil MeHg levels were rather comparable in Se-amended soils during rice growth period, irrespective of added sulfate doses. The more important role of Se than sulfate in controlling MeHg production was explained by the formation of HgSe nanoparticles irrespective of the presence of sulfate, confirmed by TEM-EDX and XANES analysis. Our findings regarding the effects of sulfate and Se on net MeHg production in rice paddy soil together with the mechanistic explanation of the processes advance our understanding of MeHg dynamics and risk in soil-rice systems. Copyright © 2016 Elsevier

  13. Hydrazine Sulfate (PDQ®)—Health Professional Version

    Cancer.gov

    Hydrazine sulfate has shown no anticancer activity in randomized clinical trials. Data on its effectiveness in cancer-related cachexia are inconclusive. Get detailed information about hydrazine sulfate as a treatment for people with cancer in this summary for clinicians.

  14. Biological functions of iduronic acid in chondroitin/dermatan sulfate.

    PubMed

    Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, Åke; Maccarana, Marco; Malmstrom, Anders

    2013-05-01

    The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse regulatory functions. Iduronic acid is formed by two epimerases (i.e. dermatan sulfate epimerase 1 and 2) that have different tissue distribution and properties. The role of iduronic acid in chondroitin/dermatan sulfate is highlighted by the vast changes in connective tissue features in patients with a new type of Ehler-Danlos syndrome: adducted thumb-clubfoot syndrome. Future research aims to understand the roles of the two epimerases and their interplay with the sulfotransferases involved in chondroitin sulfate/dermatan sulfate biosynthesis. Furthermore, a better definition of chondroitin/dermatan sulfate functions using different knockout models is needed. In this review, we focus on the two enzymes responsible for iduronic acid formation, as well as the role of iduronic acid in health and disease. © 2013 The Authors Journal compilation © 2013 FEBS.

  15. Biological functions of iduronic acid in chondroitin/dermatan sulfate

    PubMed Central

    Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, Åke; Maccarana, Marco; Malmstrom, Anders

    2013-01-01

    The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse regulatory functions. Iduronic acid is formed by two epimerases (i.e. dermatan sulfate epimerase 1 and 2) that have different tissue distribution and properties. The role of iduronic acid in chondroitin/dermatan sulfate is highlighted by the vast changes in connective tissue features in patients with a new type of Ehler–Danlos syndrome: adducted thumb-clubfoot syndrome. Future research aims to understand the roles of the two epimerases and their interplay with the sulfotransferases involved in chondroitin sulfate/dermatan sulfate biosynthesis. Furthermore, a better definition of chondroitin/dermatan sulfate functions using different knockout models is needed. In this review, we focus on the two enzymes responsible for iduronic acid formation, as well as the role of iduronic acid in health and disease. PMID:23441919

  16. Synthesis and anticoagulant activity of the quaternary ammonium chitosan sulfates.

    PubMed

    Fan, Lihong; Wu, Penghui; Zhang, Jinrong; Gao, Song; Wang, Libo; Li, Mingjia; Sha, Mingming; Xie, Weiguo; Nie, Min

    2012-01-01

    Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  17. Sulfated modification and anti-tumor activity of laminarin.

    PubMed

    Ji, Chen-Feng; Ji, Yu-Bin; Meng, DE-You

    2013-11-01

    The aim of this study was to investigate the sulfated modification of laminarin and the changes in structure and antitumor activity. The chlorosulfonic acid-pyridine method was applied for sulfated modification. The molecular weights of laminarin and laminarin sulfate (LAMS) were measured by high-performance liquid chromatography (HPLC), and IR and NMR spectra were also recorded. The surface conformations of laminarin and LAMS were observed with a scanning electron microscope. The antitumor activities of the two polysaccharides were also evaluated using an MTT assay. LAMS with a sulfate content of 45.92% and a molecular weight of 16,000 was synthesized. The IR spectra of laminarin and LAMS showed the characteristic absorption peaks of a polysaccharide, and LAMS also had the characteristic absorption peaks of sulfate moieties. The NMR spectra showed that laminarin and LAMS had β-(1→3) glycosidic bonds forming the main chain, and sulfate substitution was at the hydroxyl groups of C 2 and C 6 . Under the scanning electron microscope, there were clear differences in surface conformation between laminarin and LAMS; laminarin was cloud-like and spongy, while LAMS was block-like and flaky. The MTT results showed that laminarin and LAMS had inhibitory effects on LoVo cell growth, and the antitumor activity of LAMS was higher than that of laminarin at the same concentration. This suggests that sulfated modification was able to change the laminarin structure and markedly enhance the antitumor activity.

  18. Fractionation of sulfur and oxygen isotopes in sulfate by soil sorption

    NASA Astrophysics Data System (ADS)

    Van Stempvoort, D. R.; Reardon, E. J.; Fritz, P.

    1990-10-01

    Both field and laboratory data indicate that there is no significant isotope fractionation of sulfate during sorption in upland forest Podzols. The dominant sulfate sorption process in these soils is adsorption onto mineral surfaces. In the Plastic Lake watershed, Dorset, Ontario, Canada, fractions of sulfate from Podzol B-horizons have the following mean isotope (%.) compositions: water soluble sulfate, δ34S = +6.4; δ18O = -5.3; bicarbonate-exchanged sulfate by two methods, δ34S = + 4.5 and + 3.4; δ18O =-6.2 and -5.6; dissolved sulfate in B-horizon soilwater seepage, δ34S = + 4.8; δ18O = -5.4. These data indicate that soil sorption enriches dissolved sulfate in 34S by approximately 1 ± 1%. and in 18O by 0 +- 1 %. relative to sorbed sulfate. Similar results were obtained by laboratory sorption of sulfate by prepared goethite, which is a mineral representative of soil sorption sites in acidic Podzols like the one at Plastic Lake. The mean fractionation between sorbed and dissolved sulfate was found to be - 0.3%. for 34S and 0.1 %. for 18O. Earlier literature has confused the term adsorption; in many cases the more general term sorption, or retention, should be used. Pronounced fractionation of S and O isotopes in sulfate by lake and ocean sediments has been attributed to "adsorption" or "retention" but is more likely the result of sulfate reduction. Apparently, at Earth-surface conditions the only substantial isotope shifts in sulfate occur during microbial processes.

  19. 21 CFR 529.1044a - Gentamicin sulfate intrauterine solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gentamicin sulfate intrauterine solution. 529... § 529.1044a Gentamicin sulfate intrauterine solution. (a) Specifications. Each milliliter of solution contains 50 or 100 milligrams gentamicin sulfate. (b) Sponsors. See Nos. 000010, 000061, 000856, 057561...

  20. 21 CFR 529.1044a - Gentamicin sulfate intrauterine solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gentamicin sulfate intrauterine solution. 529... § 529.1044a Gentamicin sulfate intrauterine solution. (a) Specifications. Each milliliter of solution contains 50 or 100 milligrams gentamicin sulfate. (b) Sponsors. See Nos. 000010, 000061, 000856, 057561...

  1. 21 CFR 529.1044a - Gentamicin sulfate intrauterine solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate intrauterine solution. 529... § 529.1044a Gentamicin sulfate intrauterine solution. (a) Specifications. Each milliliter of solution contains 50 or 100 milligrams gentamicin sulfate. (b) Sponsors. See Nos. 000010, 000061, 000856, 057561...

  2. 21 CFR 529.1044a - Gentamicin sulfate intrauterine solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gentamicin sulfate intrauterine solution. 529... § 529.1044a Gentamicin sulfate intrauterine solution. (a) Specifications. Each milliliter of solution contains 50 or 100 milligrams gentamicin sulfate. (b) Sponsors. See Nos. 000010, 000061, 000856, 000859...

  3. Removing organic matter from sulfate-rich wastewater via sulfidogenic and methanogenic pathways.

    PubMed

    Vilela, Rogerio Silveira; Damianovic, Márcia Helena Rissato Zamariolli; Foresti, Eugenio

    2014-01-01

    The simultaneous organic matter removal and sulfate reduction in synthetic sulfate-rich wastewater was evaluated for various chemical oxygen demand (COD)/sulfate ratios applied in a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. At higher COD/sulfate ratios (12.5 and 7.5), the removal of organic matter was stable, likely due to methanogenesis. A combination of sulfate reduction and methanogenesis was clearly established at COD/sulfate ratios of 3.0 and 1.9. At a COD/sulfate ratio of 1.0, the organic matter removal was likely influenced by methanogenesis inhibition. The quantity of sulfate removed at a COD/sulfate ratio of 1.0 was identical to that obtained at a ratio of 1.9, indicating a lack of available electron donors for sulfidogenesis. The sulfate reduction and organic matter removal were not maximized at the same COD/sulfate ratio; therefore, competitive inhibition must be the predominant mechanism in establishing an electron flow.

  4. Rationally designed fluorescently labeled sulfate-binding protein mutants: evaluation in the development of a sensing system for sulfate

    NASA Technical Reports Server (NTRS)

    Shrestha, Suresh; Salins, Lyndon L E.; Mark Ensor, C.; Daunert, Sylvia

    2002-01-01

    Periplasmic binding proteins from E. coli undergo large conformational changes upon binding their respective ligands. By attaching a fluorescent probe at rationally selected unique sites on the protein, these conformational changes in the protein can be monitored by measuring the changes in fluorescence intensity of the probe which allow the development of reagentless sensing systems for their corresponding ligands. In this work, we evaluated several sites on bacterial periplasmic sulfate-binding protein (SBP) for attachment of a fluorescent probe and rationally designed a reagentless sensing system for sulfate. Eight different mutants of SBP were prepared by employing the polymerase chain reaction (PCR) to introduce a unique cysteine residue at a specific location on the protein. The sites Gly55, Ser90, Ser129, Ala140, Leu145, Ser171, Val181, and Gly186 were chosen for mutagenesis by studying the three-dimensional X-ray crystal structure of SBP. An environment-sensitive fluorescent probe (MDCC) was then attached site-specifically to the protein through the sulfhydryl group of the unique cysteine residue introduced. Each fluorescent probe-conjugated SBP mutant was characterized in terms of its fluorescence properties and Ser171 was determined to be the best site for the attachment of the fluorescent probe that would allow for the development of a reagentless sensing system for sulfate. Three different environment-sensitive fluorescent probes (1,5-IAEDANS, MDCC, and acylodan) were studied with the SBP171 mutant protein. A calibration curve for sulfate was constructed using the labeled protein and relating the change in the fluorescence intensity with the amount of sulfate present in the sample. The detection limit for sulfate was found to be in the submicromolar range using this system. The selectivity of the sensing system was demonstrated by evaluating its response to other anions. A fast and selective sensing system with detection limits for sulfate in the

  5. Reconstruction of secular variation in seawater sulfate concentrations

    NASA Astrophysics Data System (ADS)

    Algeo, T. J.; Luo, G. M.; Song, H. Y.; Lyons, T. W.; Canfield, D. E.

    2015-04-01

    Long-term secular variation in seawater sulfate concentrations ([SO42-]SW) is of interest owing to its relationship to the oxygenation history of Earth's surface environment. In this study, we develop two complementary approaches for quantification of sulfate concentrations in ancient seawater and test their application to late Neoproterozoic (635 Ma) to Recent marine units. The "rate method" is based on two measurable parameters of paleomarine systems: (1) the S-isotope fractionation associated with microbial sulfate reduction (MSR), as proxied by Δ34SCAS-PY, and (2) the maximum rate of change in seawater sulfate, as proxied by &partial; δ 34SCAS/∂ t(max). The "MSR-trend method" is based on the empirical relationship of Δ34SCAS-PY to aqueous sulfate concentrations in 81 modern depositional systems. For a given paleomarine system, the rate method yields an estimate of maximum possible [SO42-]SW (although results are dependent on assumptions regarding the pyrite burial flux, FPY), and the MSR-trend method yields an estimate of mean [SO42-]SW. An analysis of seawater sulfate concentrations since 635 Ma suggests that [SO42-]SW was low during the late Neoproterozoic (<5 mM), rose sharply across the Ediacaran-Cambrian boundary (~5-10 mM), and rose again during the Permian (~10-30 mM) to levels that have varied only slightly since 250 Ma. However, Phanerozoic seawater sulfate concentrations may have been drawn down to much lower levels (~1-4 mM) during short (<~2 Myr) intervals of the Cambrian, Early Triassic, Early Jurassic, and Cretaceous as a consequence of widespread ocean anoxia, intense MSR, and pyrite burial. The procedures developed in this study offer potential for future high-resolution quantitative analyses of paleo-seawater sulfate concentrations.

  6. Origin of secondary sulfate minerals on active andesitic stratovolcanoes

    USGS Publications Warehouse

    Zimbelman, D.R.; Rye, R.O.; Breit, G.N.

    2005-01-01

    Sulfate minerals in altered rocks on the upper flanks and summits of active andesitic stratovolcanoes result from multiple processes. The origin of these sulfates at five active volcanoes, Citlalte??petl (Mexico), and Mount Adams, Hood, Rainier, and Shasta (Cascade Range, USA), was investigated using field observations, petrography, mineralogy, chemical modeling, and stable-isotope data. The four general groups of sulfate minerals identified are: (1) alunite group, (2) jarosite group, (3) readily soluble Fe- and Al-hydroxysulfates, and (4) simple alkaline-earth sulfates such as anhydrite, gypsum, and barite. Generalized assemblages of spatially associated secondary minerals were recognized: (1) alunite+silica??pyrite??kaolinite?? gypsum??sulfur, (2) jarosite+alunite+silica; (3) jarosite+smectite+silica??pyrite, (4) Fe- and Al-hydroxysulfates+silica, and (5) simple sulfates+silica??Al-hydroxysulfates??alunite. Isotopic data verify that all sulfate and sulfide minerals and their associated alteration assemblages result largely from the introduction of sulfur-bearing magmatic gases into meteoric water in the upper levels of the volcanoes. The sulfur and oxygen isotopic data for all minerals indicate the general mixing of aqueous sulfate derived from deep (largely disproportionation of SO2 in magmatic vapor) and shallow (oxidation of pyrite or H2S) sources. The hydrogen and oxygen isotopic data of alunite indicate the mixing of magmatic and meteoric fluids. Some alunite-group minerals, along with kaolinite, formed from sulfuric acid created by the disproportionation of SO2 in a condensing magmatic vapor. Such alunite, observed only in those volcanoes whose interiors are exposed by erosion or edifice collapse, may have ??34S values that reflect equilibrium (350??50 ??C) between aqueous sulfate and H2S. Alunite with ??34S values indicating disequilibrium between parent aqueous sulfate and H2S may form from aqueous sulfate created in higher level low

  7. Acidic Fluids Across Mars: Detections of Magnesium-Nickel Sulfates

    NASA Technical Reports Server (NTRS)

    Yen, A. S.; Ming, D. W.; Gellert, R.; Mittlefehldt, D. W.; Rampe, E. B.; Vaniman, D. T.; Thompson, L. M.; Morris, R. V.; Clark, B. C.; VanBommel, S. J.

    2017-01-01

    Calcium, magnesium and ferric iron sulfates have been detected by the instrument suites on the Mars rovers. A subset of the magnesium sulfates show clear associations with nickel. These associations indicate Ni(2+) co-precipitation with or substitution for Mg(2+) from sulfate-saturated solutions. Nickel is ex-tracted from primary rocks almost exclusively at pH values less than 6, constraining the formation of these Mg-Ni sulfates to mildly to strongly acidic conditions. There is clear evidence for aqueous alteration at the rim of Endeavour Crater (Meridiani Planum), in the Murray formation mudstone (Gale Crater), and near Home Plate (Gusev Crater). The discovery of Mg-Ni sulfates at these locations indicates a history of fluid-rock interactions at low pH.

  8. SULFATE-REDUCING BACTERIA IN THE SEAGRASS RHIZOSPHERE

    EPA Science Inventory

    Seagrasses are rooted in anoxic sediments that support high levels of microbial activity including utilization of sulfate as a terminal electron acceptor which is reduced to sulfide. Sulfate reduction in seagrass bed sediments is stimulated by input of organic carbon through the ...

  9. XANES mapping of organic sulfate in three scleractinian coral skeletons

    NASA Astrophysics Data System (ADS)

    Cuif, Jean-Pierre; Dauphin, Yannicke; Doucet, Jean; Salome, Murielle; Susini, Jean

    2003-01-01

    The presence and localization of organic sulfate within coral skeletons are studied by using X-ray absorption near edge structure spectroscopy (XANES) fluorescence. XANES spectra are recorded from four reference sulfur-bearing organic molecules: three amino acids (H-S-C bonds in cysteine; C-S-C bonds in methionine; one disulfide bond C-S-S-C bonds in cystine) and a sulfated sugar (C-SO 4 bonds in chondroitin sulfate). Spectral responses of three coral skeletons show that the sulfated form is extremely dominant in coral aragonite, and practically exclusive within both centres of calcification and the surrounding fibrous tissues of coral septa. Mapping of S-sulfate concentrations in centres and fibres gives us direct evidence of high concentration of organic sulfate in centres of calcification. Additionally, a banding pattern of S-sulfate is visible in fibrous part of the coral septa, evidencing a biochemical zonation that corresponds to the step-by-step growth of fibres.

  10. 21 CFR 520.1044a - Gentamicin sulfate oral solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate oral solution. 520.1044a... Gentamicin sulfate oral solution. (a) Specifications. Each milliliter of aqueous solution contains gentamicin sulfate equivalent to 50 milligrams of gentamicin. (b) Sponsor. See Nos. 000061 and 054925 in § 510.600(c...

  11. 21 CFR 520.1044a - Gentamicin sulfate oral solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gentamicin sulfate oral solution. 520.1044a... Gentamicin sulfate oral solution. (a) Specifications. Each milliliter of aqueous solution contains gentamicin sulfate equivalent to 50 milligrams of gentamicin. (b) Sponsor. See Nos. 000061 and 054925 in § 510.600(c...

  12. 21 CFR 524.1044c - Gentamicin sulfate ophthalmic ointment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gentamicin sulfate ophthalmic ointment. 524.1044c... § 524.1044c Gentamicin sulfate ophthalmic ointment. (a) Specifications. Each gram of ointment contains gentamicin sulfate equivalent to 3 milligrams of gentamicin. (b) Sponsors. See Nos. 000061 and 043264 in...

  13. 21 CFR 524.1044c - Gentamicin sulfate ophthalmic ointment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate ophthalmic ointment. 524.1044c... § 524.1044c Gentamicin sulfate ophthalmic ointment. (a) Specifications. Each gram of ointment contains gentamicin sulfate equivalent to 3 milligrams of gentamicin. (b) Sponsors. See Nos. 000061 and 025463 in...

  14. 21 CFR 520.1044a - Gentamicin sulfate oral solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gentamicin sulfate oral solution. 520.1044a... Gentamicin sulfate oral solution. (a) Specifications. Each milliliter of aqueous solution contains gentamicin sulfate equivalent to 50 milligrams of gentamicin. (b) Sponsor. See Nos. 000061 and 054925 in § 510.600(c...

  15. 21 CFR 524.1044c - Gentamicin sulfate ophthalmic ointment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gentamicin sulfate ophthalmic ointment. 524.1044c... § 524.1044c Gentamicin sulfate ophthalmic ointment. (a) Specifications. Each gram of ointment contains gentamicin sulfate equivalent to 3 milligrams of gentamicin. (b) Sponsors. See Nos. 000061 and 025463 in...

  16. 21 CFR 520.1044a - Gentamicin sulfate oral solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gentamicin sulfate oral solution. 520.1044a... Gentamicin sulfate oral solution. (a) Specifications. Each milliliter of aqueous solution contains gentamicin sulfate equivalent to 50 milligrams of gentamicin. (b) Sponsor. See Nos. 000061 and 054925 in § 510.600(c...

  17. 21 CFR 524.1044c - Gentamicin sulfate ophthalmic ointment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gentamicin sulfate ophthalmic ointment. 524.1044c... § 524.1044c Gentamicin sulfate ophthalmic ointment. (a) Specifications. Each gram of ointment contains gentamicin sulfate equivalent to 3 milligrams of gentamicin. (b) Sponsors. See Nos. 000061 and 025463 in...

  18. Association of Indoxyl Sulfate with Heart Failure among Patients on Hemodialysis

    PubMed Central

    Cao, Xue-Sen; Chen, Jun; Zou, Jian-Zhou; Zhong, Yi-Hong; Teng, Jie; Ji, Jun; Chen, Zhang-Wei; Liu, Zhong-Hua; Shen, Bo; Nie, Yu-Xin; Lv, Wen-Lv; Xiang, Fang-Fang; Tan, Xiao

    2015-01-01

    Background and objectives Indoxyl sulfate, a protein-bound uremic toxin, may be associated with cardiovascular events and mortality in patients with CKD. This study aimed to investigate the relationship between indoxyl sulfate and heart failure in patients on hemodialysis. Design, setting, participants, & measurements Patients on hemodialysis for >6 months were enrolled within 6 months. Patients with congestive heart failure, angina pectoris, acute myocardial infarction, cerebral infarction, or cerebral hemorrhage within 3 months before the study or those <18 years old were excluded. The primary end point was first heart failure event during follow-up. Results In total, 258 patients (145 men) with a mean age of 57.0±14.6 years old were enrolled. Median plasma indoxyl sulfate level was used to categorize patients into two groups: the low-indoxyl sulfate group (indoxyl sulfate ≤32.35 μg/ml) and the high-indoxyl sulfate group (indoxyl sulfate >32.35 μg/ml). Then, patients were prospectively followed up for a median of 48.0 (interquartile range: 33.5–48.0) months. During follow-up, 68 patients experienced episodes of first heart failure. Kaplan–Meier analysis revealed the incidence of first heart failure event in the high–indoxyl sulfate group was significantly higher than in the low-indoxyl sulfate group (log rank P<0.001). Cox regression analysis showed indoxyl sulfate was significantly associated with first heart failure event (indoxyl sulfate as the continuous variable: hazard ratio, 1.02; 95% confidence interval [95% CI], 1.01 to 1.03; P=0.001; indoxyl sulfate as the dichotomous variable: hazard ratio, 3.49; 95% CI, 1.97 to 6.20; P<0.001). After adjustment for other confounding factors, the results remained significant (indoxyl sulfate as the continuous variable: hazard ratio, 1.04; 95% CI, 1.02 to 1.06; P<0.001; indoxyl sulfate as the dichotomous variable: hazard ratio, 5.31; 95% CI, 2.43 to 11.58; P<0.001). Conclusions Plasma indoxyl sulfate was

  19. On the sulfation of O-desmethyltramadol by human cytosolic sulfotransferases.

    PubMed

    Rasool, Mohammed I; Bairam, Ahsan F; Kurogi, Katsuhisa; Liu, Ming-Cheh

    2017-10-01

    Previous studies have demonstrated that sulfate conjugation is involved in the metabolism of the active metabolite of tramadol, O-desmethyltramadol (O-DMT). The current study aimed to systematically identify the human cytosolic sulfotransferases (SULTs) that are capable of mediating the sulfation of O-DMT. The sulfation of O-DMT under metabolic conditions was demonstrated using HepG2 hepatoma cells and Caco-2 human colon carcinoma cells. O-DMT-sulfating activity of thirteen known human SULTs and four human organ specimens was examined using an established sulfotransferase assay. pH-Dependency and kinetic parameters were also analyzed using, respectively, buffers at different pHs and varying O-DMT concentrations in the assays. Of the thirteen human SULTs tested, only SULT1A3 and SULT1C4 were found to display O-DMT-sulfating activity, with different pH-dependency profiles. Kinetic analysis revealed that SULT1C4 was 60 times more catalytically efficient in mediating the sulfation of O-DMT than SULT1A3 at respective optimal pH. Of the four human organ specimens tested, the cytosol prepared from the small intestine showed much higher O-DMT-sulfating activity than cytosols prepared from liver, lung, and kidney. Both cultured HepG2 and Caco-2 cells were shown to be capable of sulfating O-DMT and releasing sulfated O-DMT into cultured media. SULT1A3 and SULT1C4 were the major SULTs responsible for the sulfation of O-DMT. Collectively, the results obtained provided a molecular basis underlying the sulfation of O-DMT and contributed to a better understanding about the pharmacokinetics and pharmacodynamics of tramadol in humans. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  20. Recycling ferrous sulfate via super-oxidant synthesis

    NASA Astrophysics Data System (ADS)

    Kanari, N.; Evrard, O.; Neveux, N.; Ninane, L.

    2001-11-01

    Hydrated ferrous sulfate, a by-product of the titanium-dioxide and steel-surface-treatment industries, is usually disposed of as waste at a significant extra cost for these industries. Due to tight environmental regulations in the European countries, waste disposal of ferrous sulfate will not be an acceptable solution in the near future. Consequently, the waste will have to be treated. Recently, ferrous sulfate was successfully used to synthesize a novel superoxidant material (potassium ferrate) containing iron in hexavalent state (FeVI). With ferrates synthesis, innovative applications are possible in different industrial sectors, such as treatment of water and wastewater and effluent decontamination.

  1. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate.

    PubMed

    Restaino, Odile Francesca; Finamore, Rosario; Diana, Paola; Marseglia, Mariacarmela; Vitiello, Mario; Casillo, Angela; Bedini, Emiliano; Parrilli, Michelangelo; Corsaro, Maria Michela; Trifuoggi, Marco; De Rosa, Mario; Schiraldi, Chiara

    2017-03-15

    Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

  2. Mono- and Polyhydrated Sulfates in Tithonium Chasma

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image of sulfate-containing deposits in Tithonium Chasma was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1538 UTC (11:38 a.m. EDT) on August 31, 2007 near 5.22 degrees south latitude, 270.48 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 40 meters (132 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point.

    Tithonium Chasma lies at the western end of the Valles Marineris canyon system. It extends approximately east-west for roughly 810 kilometers (503 miles), varies in width from approximately 10 to 110 kilometers (6 to 68 miles), and cuts into the Martian surface to a maximum depth of roughly 6 kilometers (4 miles).

    The top panel in the montage above shows the location of the CRISM image on a mosaic taken by the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS). The CRISM data covers an area centered on a ridge of erosion-resistant rock.

    The center left image, an infrared false color image, reveals banded, light-colored material draped on the ridge. The center right image unveils the mineralogical composition of the area, with yellow representing monohydrated sulfates (sulfates with one water molecule incorporated into each molecule of the mineral) and purple polyhydrated sulfates (sulfates with multiple waters per mineral molecule).

    The lower two images are renderings of data draped over topography with 7 times vertical exaggeration. These images provide a view of the topography and reveal how the sulfate deposits both cover and flank the ridge. Brighter, monohydrated sulfate (yellow) deposits revealed in the lower right image lies along the ridge's northwest side and fall off into a small valley or depression, while darker polyhydrated sulfates (purple) lie along the ridge's northeast flank. A deposit of both mono- and polyhydrated sulfates spanning the ridge

  3. Bioleaching of heavy metals from sewage sludge by indigenous iron-oxidizing microorganisms using ammonium ferrous sulfate and ferrous sulfate as energy sources: a comparative study.

    PubMed

    Pathak, Ashish; Dastidar, M G; Sreekrishnan, T R

    2009-11-15

    The potential of indigenous iron-oxidizing microorganisms enriched at initial neutral pH of the sewage sludge for bioleaching of heavy metals was investigated at initial neutral pH of the sludge using ammonium ferrous sulfate (FAS) and ferrous sulfate (FS) as an energy sources in two different sets of experiments. After 16 days of bioleaching, 56% Cu, 48% Ni, 68% Zn and 42% C were removed from the sludge using ammonium ferrous sulfate as an energy source. On the other hand, 64% Cu, 58% Ni, 76% Zn and 52% Cr were removed using ferrous sulfate. Further, 32% nitrogen and 24% phosphorus were leached from the sludge using ferrous sulfate, whereas only 22% nitrogen and 17% phosphorus were removed using ammonium ferrous sulfate. The BCR sequential extraction study on speciation of metals showed that using ammonium ferrous sulfate and ferrous sulfate, all the metals remained in bioleached sludge as stable form (F4 fraction). The results of the present study indicate that the bioleached sludge would be safer for land application. Also, the fertilizing property was largely conserved in the bioleached sludge using both the substrates.

  4. Morphological, structural, and spectral characteristics of amorphous iron sulfates

    PubMed Central

    Sklute, E. C.; Jensen, H. B.; Rogers, A. D.; Reeder, R. J.

    2018-01-01

    Current or past brine hydrologic activity on Mars may provide suitable conditions for the formation of amorphous ferric sulfates. Once formed, these phases would likely be stable under current Martian conditions, particularly at low- to mid-latitudes. Therefore, we consider amorphous iron sulfates (AIS) as possible components of Martian surface materials. Laboratory AIS were created through multiple synthesis routes and characterized with total X-ray scattering, thermogravimetric analysis, scanning electron microscopy, visible/near-infrared (VNIR), thermal infrared (TIR), and Mössbauer techniques. We synthesized amorphous ferric sulfates (Fe(III)2(SO4)3 · ~ 6–8H2O) from sulfate-saturated fluids via vacuum dehydration or exposure to low relative humidity (<11%). Amorphous ferrous sulfate (Fe(II)SO4 · ~1H2O) was synthesized via vacuum dehydration of melanterite. All AIS lack structural order beyond 11 Å. The short-range (<5 Å) structural characteristics of amorphous ferric sulfates resemble all crystalline reference compounds; structural characteristics for the amorphous ferrous sulfate are similar to but distinct from both rozenite and szomolnokite. VNIR and TIR spectral data for all AIS display broad, muted features consistent with structural disorder and are spectrally distinct from all crystalline sulfates considered for comparison. Mössbauer spectra are also distinct from crystalline phase spectra available for comparison. AIS should be distinguishable from crystalline sulfates based on the position of their Fe-related absorptions in the visible range and their spectral characteristics in the TIR. In the NIR, bands associated with hydration at ~1.4 and 1.9 μm are significantly broadened, which greatly reduces their detectability in soil mixtures. AIS may contribute to the amorphous fraction of soils measured by the Curiosity rover. PMID:29675340

  5. Localized sulfate-reducing zones in a coastal plain aquifer

    USGS Publications Warehouse

    Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.

    1999-01-01

    High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.

  6. 21 CFR 172.399 - Zinc methionine sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

  7. 21 CFR 172.399 - Zinc methionine sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

  8. Tyrosine sulfation modulates activity of tick-derived thrombin inhibitors

    NASA Astrophysics Data System (ADS)

    Thompson, Robert E.; Liu, Xuyu; Ripoll-Rozada, Jorge; Alonso-García, Noelia; Parker, Benjamin L.; Pereira, Pedro José Barbosa; Payne, Richard J.

    2017-09-01

    Madanin-1 and chimadanin are two small cysteine-free thrombin inhibitors that facilitate blood feeding in the tick Haemaphysalis longicornis. Here, we report a post-translational modification—tyrosine sulfation—of these two proteins that is critical for potent anti-thrombotic and anticoagulant activity. Inhibitors produced in baculovirus-infected insect cells displayed heterogeneous sulfation of two tyrosine residues within each of the proteins. One-pot ligation-desulfurization chemistry enabled access to homogeneous samples of all possible sulfated variants of the proteins. Tyrosine sulfation of madanin-1 and chimadanin proved crucial for thrombin inhibitory activity, with the doubly sulfated variants three orders of magnitude more potent than the unmodified inhibitors. The three-dimensional structure of madanin-1 in complex with thrombin revealed a unique mode of inhibition, with the sulfated tyrosine residues binding to the basic exosite II of the protease. The importance of tyrosine sulfation within this family of thrombin inhibitors, together with their unique binding mode, paves the way for the development of anti-thrombotic drug leads based on these privileged scaffolds.

  9. Persistent sulfate formation from London Fog to Chinese haze

    PubMed Central

    Wang, Gehui; Zhang, Renyi; Gomez, Mario E.; Yang, Lingxiao; Levy Zamora, Misti; Hu, Min; Lin, Yun; Peng, Jianfei; Guo, Song; Meng, Jingjing; Li, Jianjun; Cheng, Chunlei; Hu, Tafeng; Ren, Yanqin; Wang, Yuesi; Gao, Jian; Cao, Junji; An, Zhisheng; Zhou, Weijian; Li, Guohui; Wang, Jiayuan; Tian, Pengfei; Marrero-Ortiz, Wilmarie; Secrest, Jeremiah; Du, Zhuofei; Zheng, Jing; Shang, Dongjie; Zeng, Limin; Shao, Min; Wang, Weigang; Huang, Yao; Wang, Yuan; Zhu, Yujiao; Li, Yixin; Hu, Jiaxi; Pan, Bowen; Cai, Li; Cheng, Yuting; Ji, Yuemeng; Zhang, Fang; Rosenfeld, Daniel; Liss, Peter S.; Duce, Robert A.; Kolb, Charles E.; Molina, Mario J.

    2016-01-01

    Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions. Under polluted environments, this SO2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH3 and NO2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world. PMID:27849598

  10. Competition and coexistence of sulfate-reducing bacteria, acetogens and methanogens in a lab-scale anaerobic bioreactor as affected by changing substrate to sulfate ratio

    PubMed Central

    Dar, Shabir A.; Kleerebezem, Robbert; Stams, Alfons J. M.; Kuenen, J. Gijs

    2008-01-01

    The microbial population structure and function of natural anaerobic communities maintained in lab-scale continuously stirred tank reactors at different lactate to sulfate ratios and in the absence of sulfate were analyzed using an integrated approach of molecular techniques and chemical analysis. The population structure, determined by denaturing gradient gel electrophoresis and by the use of oligonucleotide probes, was linked to the functional changes in the reactors. At the influent lactate to sulfate molar ratio of 0.35 mol mol−1, i.e., electron donor limitation, lactate oxidation was mainly carried out by incompletely oxidizing sulfate-reducing bacteria, which formed 80–85% of the total bacterial population. Desulfomicrobium- and Desulfovibrio-like species were the most abundant sulfate-reducing bacteria. Acetogens and methanogenic Archaea were mostly outcompeted, although less than 2% of an acetogenic population could still be observed at this limiting concentration of lactate. In the near absence of sulfate (i.e., at very high lactate/sulfate ratio), acetogens and methanogenic Archaea were the dominant microbial communities. Acetogenic bacteria represented by Dendrosporobacter quercicolus-like species formed more than 70% of the population, while methanogenic bacteria related to uncultured Archaea comprising about 10–15% of the microbial community. At an influent lactate to sulfate molar ratio of 2 mol mol−1, i.e., under sulfate-limiting conditions, a different metabolic route was followed by the mixed anaerobic community. Apparently, lactate was fermented to acetate and propionate, while the majority of sulfidogenesis and methanogenesis were dependent on these fermentation products. This was consistent with the presence of significant levels (40–45% of total bacteria) of D. quercicolus-like heteroacetogens and a corresponding increase of propionate-oxidizing Desulfobulbus-like sulfate-reducing bacteria (20% of the total bacteria). Methanogenic

  11. Preparation and evaluation of polysaccharide sulfates for inhibiting Helicobacter pylori adhesion.

    PubMed

    Song, Weijuan; Wang, Yalong; Zhang, Liyan; Fu, Shengnan; Zeng, Ying; Hu, Haiyan

    2014-03-15

    In treatments of Helicobacter pylori infections, recrudescences were common because of an unfavorable bacterial eradication rate due to the ever increasing resistance to antibiotics. In this study, we chose pectin, guar gum and chitosan to synthesize their sulfates to inhibit adhesions of H. pylori and thus enhance the eradication rate. The introduction of sulfates was characterized using FT-IR and elemental analysis. Data from zeta-potential, hydrodynamic diameter, hydrolysis and rheological property demonstrated the sulfates were physicochemically stable. Inhibition assay of hemagglutination and adhesion indicated sulfates prevented H. pylori from adhering to erythrocytes and AGS cells. In binding assay, affinities of sulfates to H. pylori suggested sulfates could compete with target cells for bacteria and moderated the bacterial adhesion to hosts. A higher content of galactoses and 2,3-O-linked sulfates benefited this action. Thus polysaccharide sulfates can serve as potential adjuvants to raise the bacterial eradication rate by inhibiting adhesions of H. pylori. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Heparan sulfate niche for cell proliferation in the adult brain.

    PubMed

    Mercier, Frederic; Arikawa-Hirasawa, Eri

    2012-02-29

    In adulthood, new neurons and glial cells are generated from stem cells in restricted zones of the brain, namely the olfactory bulb (OB), rostral migratory stream (RMS), subventricular zone (SVZ) of the lateral ventricle, sub-callosum zone (SCZ) and sub-granular layer (SGL) of the dentate gyrus. What makes these zones germinal? We previously reported that N-sulfated heparan sulfates (N-sulfated HS) present in specialized extracellular matrix structures (fractones) and vascular basement membranes bind the neurogenic factor FGF-2 (fibroblast growth factor-2) next to stem cells in the anterior SVZ of the lateral ventricle, the most neurogenic zone in adulthood. To determine to which extent cell proliferation is associated with N-sulfated HS, we mapped N-sulfated HS and proliferating cells by immunohistochemistry throughout the adult mouse brain. We found that cell proliferation is associated with N-sulfated HS in the OB, RMS, the whole germinal SVZ, and the SCZ. Cell proliferation was weakly associated with N-sulfated HS in the SGL, but the SGL was directly connected to a sub-cortical N-sulfated HS+ extension of the meninges. The NS-sulfated HS+ structures were blood vessels in the OB, RMS and SCZ, and primarily fractones in the SVZ. N-sulfated HS+ fractones, blood vessels and meninges formed a continuum that coursed along the OB, SVZ, RMS, SCZ and SGL, challenging the view that these structures are independent germinal entities. These results support the possibility that a single anatomical system might be globally responsible for mitogenesis and ultimately the production of new neurons and glial cells in the adult brain. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand.

    PubMed

    Seipp, Charles A; Williams, Neil J; Custelcean, Radu

    2016-09-08

    A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. The sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. The ligand can be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, (35)S-labeled sulfate and β liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.

  14. 21 CFR 172.399 - Zinc methionine sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine sulfate, CAS Reg. No. 56329-42-1, may be safely used in accordance with the following prescribed conditions: (a) The additive is the product of the...

  15. Sulfate and nitrate collected by filter sampling near the tropopause

    NASA Technical Reports Server (NTRS)

    Humenik, F. M.; Lezberg, E. A.; Otterson, D. A.

    1980-01-01

    Filter samples collected near the tropopause with an F-106 aircraft and two Boeing 747 aircraft were analyzed for sulfate and nitrate ion content. Within the range of routine commercial flight altitudes (at or below 12.5 km), stratospheric mass mixing ratios for the winter-spring group averaged 0.26 ppbm for sulfate and 0.35 ppbm for nitrate. For the summer-fall group, stratosphere mixing ratios averaged 0.13 ppbm and 0.25 ppbm for sulfate and nitrate, respectively. Winter-spring group tropospheric mass mixing ratios averaged 0.08 ppbm for sulfate and 0.10 ppbm for nitrate, while summer-fall group tropospheric mixing ratios averaged 0.05 ppbm for sulfate and 0.08 ppbm for nitrate. Correlations of the filter data with available ozone data suggest that the sulfate and nitrate are transported from the stratosphere to the troposphere.

  16. Vitamin C-sulfate inhibits mineralization in chondrocyte cultures: a caveat

    NASA Technical Reports Server (NTRS)

    Boskey, A. L.; Blank, R. D.; Doty, S. B.

    2001-01-01

    Differentiating chick limb-bud mesenchymal cell micro-mass cultures routinely mineralize in the presence of 10% fetal calf serum, antibiotics, 4 mM inorganic phosphate (or 2.5 mM beta-glycerophosphate), 0.3 mg/ml glutamine and either 25 microg/ml vitamin C or 5-12 microg/ml vitamin C-sulfate. The failure of these cultures to produce a mineralized matrix (assessed by electron microscopy, 45Ca uptake and Fourier transform infrared microscopy) led to the evaluation of each of these additives. We report here that the "stable" vitamin C-sulfate (ascorbic acid-2-sulfate) causes increased sulfate incorporation into the cartilage matrix. Furthermore, the release of sulfate from the vitamin C derivative appears to be responsible for the inhibition of mineral deposition, as demonstrated in cultures with equimolar amounts of vitamin C and sodium sulfate.

  17. Loss of the anion exchanger DRA (Slc26a3), or PAT1 (Slc26a6), alters sulfate transport by the distal ileum and overall sulfate homeostasis.

    PubMed

    Whittamore, Jonathan M; Hatch, Marguerite

    2017-09-01

    The ileum is considered the primary site of inorganic sulfate ([Formula: see text]) absorption. In the present study, we explored the contributions of the apical chloride/bicarbonate (Cl - /[Formula: see text]) exchangers downregulated in adenoma (DRA; Slc26a3), and putative anion transporter 1 (PAT1; Slc26a6), to the underlying transport mechanism. Transepithelial 35 [Formula: see text] and 36 Cl - fluxes were determined across isolated, short-circuited segments of the distal ileum from wild-type (WT), DRA-knockout (KO), and PAT1-KO mice, together with measurements of urine and plasma sulfate. The WT distal ileum supported net sulfate absorption [197.37 ± 13.61 (SE) nmol·cm -2 ·h -1 ], but neither DRA nor PAT1 directly contributed to the unidirectional mucosal-to-serosal flux ([Formula: see text]), which was sensitive to serosal (but not mucosal) DIDS, dependent on Cl - , and regulated by cAMP. However, the absence of DRA significantly enhanced net sulfate absorption by one-third via a simultaneous rise in [Formula: see text] and a 30% reduction to the secretory serosal-to-mucosal flux ([Formula: see text]). We propose that DRA, together with PAT1, contributes to [Formula: see text] by mediating sulfate efflux across the apical membrane. Associated with increased ileal sulfate absorption in vitro, plasma sulfate was 61% greater, and urinary sulfate excretion ( U SO4 ) 2.2-fold higher, in DRA-KO mice compared with WT controls, whereas U SO4 was increased 1.8-fold in PAT1-KO mice. These alterations to sulfate homeostasis could not be accounted for by any changes to renal sulfate handling suggesting that the source of this additional sulfate was intestinal. In summary, we characterized transepithelial sulfate fluxes across the mouse distal ileum demonstrating that DRA (and to a lesser extent, PAT1) secretes sulfate with significant implications for intestinal sulfate absorption and overall homeostasis. NEW & NOTEWORTHY Sulfate is an essential anion that is

  18. 40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...

  19. 40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...

  20. 40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...

  1. STATISTICAL METHOD FOR DETECTION OF A TREND IN ATMOSPHERIC SULFATE

    EPA Science Inventory

    Daily atmospheric concentrations of sulfate collected in northeastern Pennsylvania are regressed against meteorological factors, ozone, and time in order to determine if a significant trend in sulfate can be detected. he data used in this analysis were collected during the Sulfat...

  2. Recoverable immobilization of transuranic elements in sulfate ash

    DOEpatents

    Greenhalgh, Wilbur O.

    1985-01-01

    Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

  3. Chondroitin sulfate effects on neural stem cell differentiation.

    PubMed

    Canning, David R; Brelsford, Natalie R; Lovett, Neil W

    2016-01-01

    We have investigated the role chondroitin sulfate has on cell interactions during neural plate formation in the early chick embryo. Using tissue culture isolates from the prospective neural plate, we have measured neural gene expression profiles associated with neural stem cell differentiation. Removal of chondroitin sulfate from stage 4 neural plate tissue leads to altered associations of N-cadherin-positive neural progenitors and causes changes in the normal sequence of neural marker gene expression. Absence of chondroitin sulfate in the neural plate leads to reduced Sox2 expression and is accompanied by an increase in the expression of anterior markers of neural regionalization. Results obtained in this study suggest that the presence of chondroitin sulfate in the anterior chick embryo is instrumental in maintaining cells in the neural precursor state.

  4. Chondroitin sulfate synthase-2 is necessary for chain extension of chondroitin sulfate but not critical for skeletal development.

    PubMed

    Ogawa, Hiroyasu; Hatano, Sonoko; Sugiura, Nobuo; Nagai, Naoko; Sato, Takashi; Shimizu, Katsuji; Kimata, Koji; Narimatsu, Hisashi; Watanabe, Hideto

    2012-01-01

    Chondroitin sulfate (CS) is a linear polysaccharide consisting of repeating disaccharide units of N-acetyl-D-galactosamine and D-glucuronic acid residues, modified with sulfated residues at various positions. Based on its structural diversity in chain length and sulfation patterns, CS provides specific biological functions in cell adhesion, morphogenesis, neural network formation, and cell division. To date, six glycosyltransferases are known to be involved in the biosynthesis of chondroitin saccharide chains, and a hetero-oligomer complex of chondroitin sulfate synthase-1 (CSS1)/chondroitin synthase-1 and chondroitin sulfate synthase-2 (CSS2)/chondroitin polymerizing factor is known to have the strongest polymerizing activity. Here, we generated and analyzed CSS2(-/-) mice. Although they were viable and fertile, exhibiting no overt morphological abnormalities or osteoarthritis, their cartilage contained CS chains with a shorter length and at a similar number to wild type. Further analysis using CSS2(-/-) chondrocyte culture systems, together with siRNA of CSS1, revealed the presence of two CS chain species in length, suggesting two steps of CS chain polymerization; i.e., elongation from the linkage region up to Mr ∼10,000, and further extension. There, CSS2 mainly participated in the extension, whereas CSS1 participated in both the extension and the initiation. Our study demonstrates the distinct function of CSS1 and CSS2, providing a clue in the elucidation of the mechanism of CS biosynthesis.

  5. Shock vaporization of carbonate and sulfate minerals

    NASA Astrophysics Data System (ADS)

    Shen, A. H.; Ahrens, T. J.; O'Keefe, J. D.

    2001-12-01

    Strong shock waves induced by impacts can cause vaporization of rocks and minerals. The products of such process play important roles in planetary differentiation (Yakovlev et al., Geochem. International, 38, 1027, 2000) and in effecting the planetary climate. Many experiments and computer simulations have been performed to simulate the Chicxulub impact at Cretaceous/Tertiary boundary (see, for example, Pierazzo et al., J. Geophys. Res., 103, 28607, 1998 and Pope et al., J. Geophys. Res., 102, 21645, 1997). However, the pressure range for incipient and complete vaporization of carbonates and sulfates are not well constrained, especially, for minerals with various initial porosities. Furthermore, evidence for chemical species in the products of vaporized carbonate and sulfate minerals is almost non-existing. In this study, we employed published Hugoniot data for carbonate and sulfate minerals. By using the methods described in Ahrens (J. Appl. Phys., 43, 2443, 1972) and Ahrens and O'Keefe (The Moon, 4, 214, 1972), we calculated the entropy associated with the thermodynamic states produced by hypervelocity impacts at various velocities for carbonate and sulfate minerals with different initial porosities. The results were compared with the entropy of incipient vaporization and complete vaporization of these minerals to determine the degree of vaporization due to impacts. Moreover, these results are utilized to guide our experimental study in speciation reactions in shock-induced vaporization of carbonates and sulfates.

  6. Antifouling potential of Nature-inspired sulfated compounds

    NASA Astrophysics Data System (ADS)

    Almeida, Joana R.; Correia-da-Silva, Marta; Sousa, Emília; Antunes, Jorge; Pinto, Madalena; Vasconcelos, Vitor; Cunha, Isabel

    2017-02-01

    Natural products with a sulfated scaffold have emerged as antifouling agents with low or nontoxic effects to the environment. In this study 13 sulfated polyphenols were synthesized and tested for antifouling potential using the anti-settlement activity of mussel (Mytilus galloprovincialis) plantigrade post-larvae and bacterial growth inhibition towards four biofilm-forming bacterial strains. Results show that some of these Nature-inspired compounds were bioactive, particularly rutin persulfate (2), 3,6-bis(β-D-glucopyranosyl) xanthone persulfate (6), and gallic acid persulfate (12) against the settlement of plantigrades. The chemical precursors of sulfated compounds 2 and 12 were also tested for anti-settlement activity and it was possible to conclude that bioactivity is associated with sulfation. While compound 12 showed the most promising anti-settlement activity (EC50 = 8.95 μg.mL-1), compound 2 also caused the higher level of growth inhibition in bacteria Vibrio harveyi (EC20 = 12.5 μg.mL-1). All the three bioactive compounds 2, 6, and 12 were also found to be nontoxic to the non target species Artemia salina (<10% mortality at 250 μM) and Vibrio fischeri (LC50 > 1000 μg.mL-1). This study put forward the relevance of synthesizing non-natural sulfated small molecules to generate new nontoxic antifouling agents.

  7. Antifouling potential of Nature-inspired sulfated compounds

    PubMed Central

    Almeida, Joana R.; Correia-da-Silva, Marta; Sousa, Emília; Antunes, Jorge; Pinto, Madalena; Vasconcelos, Vitor; Cunha, Isabel

    2017-01-01

    Natural products with a sulfated scaffold have emerged as antifouling agents with low or nontoxic effects to the environment. In this study 13 sulfated polyphenols were synthesized and tested for antifouling potential using the anti-settlement activity of mussel (Mytilus galloprovincialis) plantigrade post-larvae and bacterial growth inhibition towards four biofilm-forming bacterial strains. Results show that some of these Nature-inspired compounds were bioactive, particularly rutin persulfate (2), 3,6-bis(β-D-glucopyranosyl) xanthone persulfate (6), and gallic acid persulfate (12) against the settlement of plantigrades. The chemical precursors of sulfated compounds 2 and 12 were also tested for anti-settlement activity and it was possible to conclude that bioactivity is associated with sulfation. While compound 12 showed the most promising anti-settlement activity (EC50 = 8.95 μg.mL−1), compound 2 also caused the higher level of growth inhibition in bacteria Vibrio harveyi (EC20 = 12.5 μg.mL−1). All the three bioactive compounds 2, 6, and 12 were also found to be nontoxic to the non target species Artemia salina (<10% mortality at 250 μM) and Vibrio fischeri (LC50 > 1000 μg.mL−1). This study put forward the relevance of synthesizing non-natural sulfated small molecules to generate new nontoxic antifouling agents. PMID:28205590

  8. 21 CFR 524.1484g - Neomycin sulfate-thiabendazole-dexamethasone solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate-thiabendazole-dexamethasone... NEW ANIMAL DRUGS § 524.1484g Neomycin sulfate-thiabendazole-dexamethasone solution. (a) Specifications. Each cubic centimeter of neomycin sulfate-thiabendazole-dexamethasone solution contains: 40 milligrams...

  9. 21 CFR 524.1484g - Neomycin sulfate-thiabendazole-dexamethasone solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate-thiabendazole-dexamethasone... NEW ANIMAL DRUGS § 524.1484g Neomycin sulfate-thiabendazole-dexamethasone solution. (a) Specifications. Each cubic centimeter of neomycin sulfate-thiabendazole-dexamethasone solution contains: 40 milligrams...

  10. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sulfate salt (generic). 721.10546 Section 721.10546 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject to...

  11. 21 CFR 524.1484g - Neomycin sulfate-thiabendazole-dexamethasone solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate-thiabendazole-dexamethasone... NEW ANIMAL DRUGS § 524.1484g Neomycin sulfate-thiabendazole-dexamethasone solution. (a) Specifications. Each cubic centimeter of neomycin sulfate-thiabendazole-dexamethasone solution contains: 40 milligrams...

  12. 21 CFR 524.1484g - Neomycin sulfate-thiabendazole-dexamethasone solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate-thiabendazole-dexamethasone... NEW ANIMAL DRUGS § 524.1484g Neomycin sulfate-thiabendazole-dexamethasone solution. (a) Specifications. Each cubic centimeter of neomycin sulfate-thiabendazole-dexamethasone solution contains: 40 milligrams...

  13. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfate salt (generic). 721.10546 Section 721.10546 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject to...

  14. Hydrazine/Hydrazine sulfate

    Integrated Risk Information System (IRIS)

    Hydrazine / Hydrazine sulfate ; CASRN 302 - 01 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  15. Diversity and composition of sulfate- and sulfite-reducing prokaryotes as affected by marine-freshwater gradient and sulfate availability.

    PubMed

    Fan, Lan-Feng; Tang, Sen-Lin; Chen, Chang-Po; Hsieh, Hwey-Lian

    2012-01-01

    Sulfate- and sulfite-reducing prokaryotes (SSRP) communities play a key role in both sulfur and carbon cycles. In estuarine ecosystems, sulfate concentrations change with tides and could be limited in tidal freshwater reach or deep sediments. In a subtropical estuary of northern Taiwan in December 2007, we examined the compositional changes of SSRP communities. We examined three sites: from the lower estuarine brackish-water reach (site GR and mangrove vegetation site, GM) to the upper estuarine tidal freshwater reach (site HR), as well as from surface to a 50-cm depth. The partial sequence of sulfite reductase (dsrB) genes was used as a molecular marker of SSRP, linked to polymerase chain reaction and denaturing gradient gel electrophoresis (DGGE) techniques. SSRP communities of the DGGE profiles varied with sites according to one-way analyses of similarities (Global R = 0.69, P = 0.001). Using cluster analysis, the DGGE profile was found to show site-specific clusters and a distinct depth zonation (five, six, and two SSRP communities at the GM, GR, and HR sites, respectively). SSRP composition was highly correlated to the combination of salinity, reduced sulfur, and total organic carbon contents (BIO-ENV analysis, r ( s ) = 0.56). After analyzing a total of 35 dsrB sequences in the DGGE gel, six groups with 15 phylotypes were found, which were closely related to marine-freshwater gradient. Moreover, sequences neighboring sulfite-reducing prokaryotes were observed, in addition to those affiliated to sulfate-reducing prokaryotes. Four phylotypes harvested in HR resembled the genus Desulfitobacterium, a sulfite-reducing prokaryote, which failed to use sulfate as an electron acceptor and were active in freshwater and sulfate-limited habitat. The other five phylotypes in the HR reach belonged to the sulfate-reducing prokaryotes of the genera Desulfatiferula, Desulfosarcina, Desulfovibrio, and Desulfotomaculum, which appeared to tolerate low salinity and

  16. Sulfated steroids as natural ligands of mouse pheromone-sensing neurons.

    PubMed

    Nodari, Francesco; Hsu, Fong-Fu; Fu, Xiaoyan; Holekamp, Terrence F; Kao, Lung-Fa; Turk, John; Holy, Timothy E

    2008-06-18

    Among mice, pheromones and other social odor cues convey information about sex, social status, and identity; however, the molecular nature of these cues is essentially unknown. To identify these cues, we screened chromatographic fractions of female mouse urine for their ability to cause reproducible firing rate increases in the pheromone-detecting vomeronasal sensory neurons (VSNs) using multielectrode array (MEA) recording. Active compounds were found to be remarkably homogenous in their basic properties, with most being of low molecular weight, moderate hydrophobicity, low volatility, and possessing a negative electric charge. Purification and structural analysis of active compounds revealed multiple sulfated steroids, of which two were identified as sulfated glucocorticoids, including corticosterone 21-sulfate. Sulfatase-treated urine extracts lost >80% of their activity, indicating that sulfated compounds are the predominant VSN ligands in female mouse urine. As measured by MEA recording, a collection of 31 synthetic sulfated steroids triggered responses 30-fold more frequently than did a similarly sized stimulus set containing the majority of all previously reported VSN ligands. Collectively, VSNs detected all major classes of sulfated steroids, but individual neurons were sensitive to small variations in chemical structure. VSNs from both males and females detected sulfated steroids, but knock-outs for the sensory transduction channel TRPC2 did not detect these compounds. Urine concentrations of the two sulfated glucocorticoids increased many fold in stressed animals, indicating that information about physiological status is encoded by the urine concentration of particular sulfated steroids. These results provide an unprecedented characterization of the signals available for chemical communication among mice.

  17. Sulfated steroids as natural ligands of mouse pheromone-sensing neurons

    PubMed Central

    Nodari, Francesco; Hsu, Fong-Fu; Fu, Xiaoyan; Holekamp, Terrence F.; Kao, Lung-Fa; Turk, John; Holy, Timothy E.

    2009-01-01

    Among mice, pheromones and other social odor cues convey information about sex, social status, and identity; however, the molecular nature of these cues is largely unknown. To identify these cues, we screened chromatographic fractions of female mouse urine for their ability to cause reproducible firing rate increases in the pheromone-detecting vomeronasal sensory neurons (VSNs) using multielectrode array (MEA) recording. Active compounds were found to be remarkably homogenous in their basic properties, with most being of low molecular weight, moderate hydrophobicity, low volatility, and possessing a negative electric charge. Purification and structural analysis of active compounds revealed multiple sulfated steroids, of which two were identified as sulfated glucocorticoids, including corticosterone 21-sulfate. Sulfatase-treated urine extracts lost more than 80% of their activity, indicating that sulfated compounds are the predominant VSN ligands in female mouse urine. As measured by MEA recording, a collection of 31 synthetic sulfated steroids triggered responses 30-fold more frequently than did a similarly-sized stimulus set containing the majority of all previously-reported VSN ligands. Collectively, VSNs detected all major classes of sulfated steroids, but individual neurons were sensitive to small variations in chemical structure. VSNs from both males and females detected sulfated steroids, but knockouts for the sensory transduction channel TRPC2 did not detect these compounds. Urine concentrations of the two sulfated glucocorticoids increased many-fold in stressed animals, indicating that information about physiological status is encoded by the urine concentration of particular sulfated steroids. These results provide an unprecedented characterization of the signals available for chemical communication among mice. PMID:18562612

  18. The origin of 2.7 eV luminescence and 5.2 eV excitation band in hafnium oxide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perevalov, T. V., E-mail: timson@isp.nsc.ru; Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk; Aliev, V. Sh.

    2014-02-17

    The origin of a blue luminescence band at 2.7 eV and a luminescence excitation band at 5.2 eV of hafnia has been studied in stoichiometric and non-stoichiometric hafnium oxide films. Experimental and calculated results from the first principles valence band spectra showed that the stoichiometry violation leads to the formation of the peak density of states in the band gap caused by oxygen vacancies. Cathodoluminescence in the non-stoichiometric film exhibits a band at 2.65 eV that is excited at the energy of 5.2 eV. The optical absorption spectrum calculated for the cubic phase of HfO{sub 2} with oxygen vacancies showsmore » a peak at 5.3 eV. Thus, it could be concluded that the blue luminescence band at 2.7 eV and HfO{sub x} excitation peak at 5.2 eV are due to oxygen vacancies. The thermal trap energy in hafnia was estimated.« less

  19. IER-297 CED-2: Final Design for Thermal/Epithermal eXperiments with Jemima Plates with Polyethylene and Hafnium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nelson, A. J.; Percher, C. M.; Zywiec, W. J.

    This report presents the final design (CED-2) for IER-297, and focuses on 15 critical configurations using highly enriched uranium (HEU) Jemima plates moderated by polyethylene with and without hafnium diluent. The goal of the U.S. Nuclear Criticality Safety Program’s Thermal/Epithermal eXperiments (TEX) is to design and conduct new critical experiments to address high priority nuclear data needs from the nuclear criticality safety and nuclear data communities, with special emphasis on intermediate energy (0.625 eV – 100 keV) assemblies that can be easily modified to include various high priority diluent materials. The TEX (IER 184) CED-1 Report [1], completed in 2012,more » demonstrated the feasibility of meeting the TEX goals with two existing NCSP fissile assets, plutonium Zero Power Physics Reactor (ZPPR) plates and highly enriched uranium (HEU) Jemima plates. The first set of TEX experiments will focus on using the plutonium ZPPR plates with polyethylene moderator and tantalum diluents.« less

  20. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant new...

  1. 40 CFR 721.10443 - Ethoxylated alkylphenol sulfate, ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethoxylated alkylphenol sulfate... New Uses for Specific Chemical Substances § 721.10443 Ethoxylated alkylphenol sulfate, ammonium salt... identified generically as ethoxylated alkylphenol sulfate, ammonium salt (PMN P-01-470) is subject to...

  2. 40 CFR 721.10443 - Ethoxylated alkylphenol sulfate, ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethoxylated alkylphenol sulfate... New Uses for Specific Chemical Substances § 721.10443 Ethoxylated alkylphenol sulfate, ammonium salt... identified generically as ethoxylated alkylphenol sulfate, ammonium salt (PMN P-01-470) is subject to...

  3. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant new...

  7. Potential for beneficial application of sulfate reducing bacteria in sulfate containing domestic wastewater treatment.

    PubMed

    van den Brand, T P H; Roest, K; Chen, G H; Brdjanovic, D; van Loosdrecht, M C M

    2015-11-01

    The activity of sulfate reducing bacteria (SRB) in domestic wastewater treatment plants (WWTP) is often considered as a problem due to H2S formation and potential related odour and corrosion of materials. However, when controlled well, these bacteria can be effectively used in a positive manner for the treatment of wastewater. The main advantages of using SRB in wastewater treatment are: (1) minimal sludge production, (2) reduction of potential pathogens presence, (3) removal of heavy metals and (4) as pre-treatment of anaerobic digestion. These advantages are accessory to efficient and stable COD removal by SRB. Though only a few studies have been conducted on SRB treatment of domestic wastewater, the many studies performed on industrial wastewater provide information on the potential of SRB in domestic wastewater treatment. A key-parameter analyses literature study comprising pH, organic substrates, sulfate, salt, temperature and oxygen revealed that the conditions are well suited for the application of SRB in domestic wastewater treatment. Since the application of SRB in WWTP has environmental benefits its application is worth considering for wastewater treatment, when sulfate is present in the influent.

  8. Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

    DOE PAGES

    Seipp, Charles A.; Williams, Neil J.; Custelcean, Radu

    2016-01-01

    One simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. Furthermore, the sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. These ligands can then be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutralmore » bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and β liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.« less

  9. Kinetics of sulfate and hydrogen uptake by the thermophilic sulfate-reducing bacteria thermodesulfobacterium sp. Strain JSP and thermodesulfovibrio sp. Strain R1Ha3

    PubMed

    Sonne-Hansen; Westermann; Ahring

    1999-03-01

    Half-saturation constants (Km), maximum uptake rates (Vmax), and threshold concentrations for sulfate and hydrogen were determined for two thermophilic sulfate-reducing bacteria (SRB) in an incubation system without headspace. Km values determined for the thermophilic SRB were similar to the constants described for mesophilic SRB isolated from environments with low sulfate concentrations.

  10. The role of sulfates on antifreeze protein activity.

    PubMed

    Meister, Konrad; Duman, John G; Xu, Yao; DeVries, Arthur L; Leitner, David M; Havenith, Martina

    2014-07-17

    In the present study, we have investigated the effect of sodium sulfate (Na2SO4) buffer on the antifreeze activity of DAFP-1, the primary AFP in the hemolymph of the beetle Dendroides canadensis. In contrast to previous studies, we found evidence that sodium sulfate does not suppress antifreeze activity of DAFP-1. Terahertz absorption spectroscopy (THz) studies were combined with molecular dynamics (MD) simulations to investigate the change in collective hydrogen bond dynamics in the vicinity of the AFP upon addition of sodium sulfate. The MD simulations revealed that the gradient of H-bond dynamics toward the ice-binding site is even more pronounced when adding sodium sulfate: The cosolute dramatically slows the hydrogen bond dynamics on the ice-binding plane of DAFP-1, whereas it has a more modest effect in the vicinity of other parts of the protein. These theoretical predictions are in agreement with the experimentally observed increase in THz absorption for solvated DAFP-1 upon addition of sodium sulfate. These studies support our previously postulated mechanism for AF activity, with a preferred ice binding by threonine on nanoice crystals which is supported by a long-range effect on hydrogen bond dynamics.

  11. Selective Synthesis and Biological Evaluation of Sulfate-Conjugated Resveratrol Metabolites

    PubMed Central

    Hoshino, Juma; Park, Eun-Jung; Kondratyuk, Tamara P.; Marler, Laura; Pezzuto, John M.; van Breemen, Richard B.; Mo, Shunyan; Li, Yongchao; Cushman, Mark

    2010-01-01

    Five resveratrol sulfate metabolites were synthesized and assessed for activities known to be mediated by resveratrol: inhibition of tumor necrosis factor (TNF)-α-induced NFκB activity, cylcooxygenases (COX-1 and COX-2), aromatase, nitric oxide production in endotoxin-stimulated macrophages, and proliferation of KB or MCF7 cells, induction of quinone reductase 1 (QR1), accumulation in the sub-G1 phase of the cell cycle, and quenching of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. Two metabolites showed activity in these assays; the 3-sulfate exhibited QR1 induction, DPPH free radical scavenging, and COX-1 and COX-2 inhibitory activities, and the 4′-sulfate inhibited NFκB induction, as well as COX-1 and COX-2 activities. Resveratrol, as well as its 3′-sulfate and 4-sulfate, inhibit NO production by NO scavenging and down-regulation of iNOS expression in RAW 264.7 cells. Resveratrol sulfates displayed low antiproliferative activity and negligible uptake in MCF7 cells. PMID:20527891

  12. Kinetics of Sulfate and Hydrogen Uptake by the Thermophilic Sulfate-Reducing Bacteria Thermodesulfobacterium sp. Strain JSP and Thermodesulfovibrio sp. Strain R1Ha3

    PubMed Central

    Sonne-Hansen, Jacob; Westermann, Peter; Ahring, Birgitte K.

    1999-01-01

    Half-saturation constants (Km), maximum uptake rates (Vmax), and threshold concentrations for sulfate and hydrogen were determined for two thermophilic sulfate-reducing bacteria (SRB) in an incubation system without headspace. Km values determined for the thermophilic SRB were similar to the constants described for mesophilic SRB isolated from environments with low sulfate concentrations. PMID:10049897

  13. Micro-SHINE Uranyl Sulfate Irradiations at the Linac

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Youker, Amanda J.; Kalensky, Michael; Chemerisov, Sergey

    2016-08-01

    Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50-MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

  14. Opiate-like excitatory effects of steroid sulfates and calcium-complexing agents given cerebroventricularly.

    PubMed

    LaBella, F S; Havlicek, V; Pinsky, C

    1979-01-12

    Intracerebroventricular administration of 10--20 microgram of steroid-O-sulfates induced hypermotility, agitation, salivation, EEG abnormalities, stereotypies, wet dog shakes and seizures. Equivalent effects resulted from 30--200 microgram morphine sulfate (H2SO4 salt), 50 microgram EGTA or 300--400 microgram of sodium sulfate or phosphate, but not chloride, nitrate or acetate. Non-steroid sulfates, steroid glucuronides and steroid phosphates were inactive. Naloxone, previously found to antagonize the excitatory effects of androsterone sulfate, failed to antagonize those of cortisol sulfate, sodium sulfate or EGTA. These findings suggest a role for extracellular calcium ions and for sulfate derived from circulating steroids in central responses to opiates.

  15. 21 CFR 524.981c - Fluocinolone acetonide, neomycin sulfate cream.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Fluocinolone acetonide, neomycin sulfate cream... ANIMAL DRUGS § 524.981c Fluocinolone acetonide, neomycin sulfate cream. (a) Specifications. The drug contains 0.025 percent fluocinolone acetonide and 0.5 percent neomycin sulfate (0.35 percent neomycin base...

  16. 21 CFR 524.981c - Fluocinolone acetonide, neomycin sulfate cream.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fluocinolone acetonide, neomycin sulfate cream... ANIMAL DRUGS § 524.981c Fluocinolone acetonide, neomycin sulfate cream. (a) Specifications. The drug contains 0.025 percent fluocinolone acetonide and 0.5 percent neomycin sulfate (0.35 percent neomycin base...

  17. 21 CFR 524.981c - Fluocinolone acetonide, neomycin sulfate cream.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Fluocinolone acetonide, neomycin sulfate cream... ANIMAL DRUGS § 524.981c Fluocinolone acetonide, neomycin sulfate cream. (a) Specifications. The drug contains 0.025 percent fluocinolone acetonide and 0.5 percent neomycin sulfate (0.35 percent neomycin base...

  18. 21 CFR 524.981c - Fluocinolone acetonide, neomycin sulfate cream.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Fluocinolone acetonide, neomycin sulfate cream... ANIMAL DRUGS § 524.981c Fluocinolone acetonide, neomycin sulfate cream. (a) Specifications. The drug contains 0.025 percent fluocinolone acetonide and 0.5 percent neomycin sulfate (0.35 percent neomycin base...

  19. Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Yang; Wang, Hailong; Smith, Steven J.

    Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burdenmore » are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.« less

  20. Successful magnesium sulfate tocolysis: is "weaning" the drug necessary?

    PubMed

    Lewis, D F; Bergstedt, S; Edwards, M S; Burlison, S; Gallaspy, J W; Brooks, G G; Adair, C D

    1997-10-01

    Magnesium sulfate is the most commonly used tocolytic agent for preterm labor. A common clinical practice is to slowly discontinue the drug (wean) after successful tocolysis. Our objective was to determine the necessity of this practice. A prospective, randomized clinical trial was performed from June 1993 to July 1996. After successful magnesium sulfate tocolysis, patients with preterm labor were randomized to two groups: stopping the drug abruptly (no weaning) or gradually weaning the drug (approximately 1 gm every 4 hours). Preterm labor was defined as documented cervical change with regular uterine contractions or regular uterine contractions with a cervix of 2 cm and 75% effacement. The primary outcome variable was the necessity to reinstitute magnesium sulfate therapy within 24 hours of discontinuation of successful tocolysis. One hundred forty-one patients completed the study. No patient in the no-wean group required retocolysis within 24 hours of magnesium discontinuation. However, eight patients in the wean group required retocolysis within 24 hours of magnesium discontinuation (p = 0.01). Significantly more patients in the wean group had retocolysis during pregnancy (3 vs 12, p = 0.03). Patients in the wean group were also in the labor and delivery unit longer and, as would be anticipated, received magnesium sulfate significantly longer. No differences in the neonatal outcomes were noted between the two groups. Seventy-seven percent of the patients in the study were delivered prematurely. This study demonstrated an increased need for retocolysis in the group weaned from magnesium sulfate. We also found that patients in the wean group had an increased labor and delivery time and a longer administration time of magnesium sulfate. Thus weaning magnesium sulfate increases health care cost. The practice of weaning magnesium sulfate does not appear beneficial.

  1. Evolutionary Relationships and Functional Diversity of Plant Sulfate Transporters

    PubMed Central

    Takahashi, Hideki; Buchner, Peter; Yoshimoto, Naoko; Hawkesford, Malcolm J.; Shiu, Shin-Han

    2011-01-01

    Sulfate is an essential nutrient cycled in nature. Ion transporters that specifically facilitate the transport of sulfate across the membranes are found ubiquitously in living organisms. The phylogenetic analysis of known sulfate transporters and their homologous proteins from eukaryotic organisms indicate two evolutionarily distinct groups of sulfate transport systems. One major group named Tribe 1 represents yeast and fungal SUL, plant SULTR, and animal SLC26 families. The evolutionary origin of SULTR family members in land plants and green algae is suggested to be common with yeast and fungal SUL and animal anion exchangers (SLC26). The lineage of plant SULTR family is expanded into four subfamilies (SULTR1–SULTR4) in land plant species. By contrast, the putative SULTR homologs from Chlorophyte green algae are in two separate lineages; one with the subfamily of plant tonoplast-localized sulfate transporters (SULTR4), and the other diverged before the appearance of lineages for SUL, SULTR, and SLC26. There also was a group of yet undefined members of putative sulfate transporters in yeast and fungi divergent from these major lineages in Tribe 1. The other distinct group is Tribe 2, primarily composed of animal sodium-dependent sulfate/carboxylate transporters (SLC13) and plant tonoplast-localized dicarboxylate transporters (TDT). The putative sulfur-sensing protein (SAC1) and SAC1-like transporters (SLT) of Chlorophyte green algae, bryophyte, and lycophyte show low degrees of sequence similarities with SLC13 and TDT. However, the phylogenetic relationship between SAC1/SLT and the other two families, SLC13 and TDT in Tribe 2, is not clearly supported. In addition, the SAC1/SLT family is absent in the angiosperm species analyzed. The present study suggests distinct evolutionary trajectories of sulfate transport systems for land plants and green algae. PMID:22629272

  2. Evolutionary relationships and functional diversity of plant sulfate transporters.

    PubMed

    Takahashi, Hideki; Buchner, Peter; Yoshimoto, Naoko; Hawkesford, Malcolm J; Shiu, Shin-Han

    2011-01-01

    Sulfate is an essential nutrient cycled in nature. Ion transporters that specifically facilitate the transport of sulfate across the membranes are found ubiquitously in living organisms. The phylogenetic analysis of known sulfate transporters and their homologous proteins from eukaryotic organisms indicate two evolutionarily distinct groups of sulfate transport systems. One major group named Tribe 1 represents yeast and fungal SUL, plant SULTR, and animal SLC26 families. The evolutionary origin of SULTR family members in land plants and green algae is suggested to be common with yeast and fungal SUL and animal anion exchangers (SLC26). The lineage of plant SULTR family is expanded into four subfamilies (SULTR1-SULTR4) in land plant species. By contrast, the putative SULTR homologs from Chlorophyte green algae are in two separate lineages; one with the subfamily of plant tonoplast-localized sulfate transporters (SULTR4), and the other diverged before the appearance of lineages for SUL, SULTR, and SLC26. There also was a group of yet undefined members of putative sulfate transporters in yeast and fungi divergent from these major lineages in Tribe 1. The other distinct group is Tribe 2, primarily composed of animal sodium-dependent sulfate/carboxylate transporters (SLC13) and plant tonoplast-localized dicarboxylate transporters (TDT). The putative sulfur-sensing protein (SAC1) and SAC1-like transporters (SLT) of Chlorophyte green algae, bryophyte, and lycophyte show low degrees of sequence similarities with SLC13 and TDT. However, the phylogenetic relationship between SAC1/SLT and the other two families, SLC13 and TDT in Tribe 2, is not clearly supported. In addition, the SAC1/SLT family is absent in the angiosperm species analyzed. The present study suggests distinct evolutionary trajectories of sulfate transport systems for land plants and green algae.

  3. In Situ Rates of Sulfate Reduction in Response to Geochemical Perturbations

    USGS Publications Warehouse

    Kneeshaw, T.A.; McGuire, J.T.; Cozzarelli, I.M.; Smith, E.W.

    2011-01-01

    Rates of in situ microbial sulfate reduction in response to geochemical perturbations were determined using Native Organism Geochemical Experimentation Enclosures (NOGEEs), a new in situ technique developed to facilitate evaluation of controls on microbial reaction rates. NOGEEs function by first trapping a native microbial community in situ and then subjecting it to geochemical perturbations through the introduction of various test solutions. On three occasions, NOGEEs were used at the Norman Landfill research site in Norman, Oklahoma, to evaluate sulfate-reduction rates in wetland sediments impacted by landfill leachate. The initial experiment, in May 2007, consisted of five introductions of a sulfate test solution over 11 d. Each test stimulated sulfate reduction with rates increasing until an apparent maximum was achieved. Two subsequent experiments, conducted in October 2007 and February 2008, evaluated the effects of concentration on sulfate-reduction rates. Results from these experiments showed that faster sulfate-reduction rates were associated with increased sulfate concentrations. Understanding variability in sulfate-reduction rates in response to perturbations may be an important factor in predicting rates of natural attenuation and bioremediation of contaminants in systems not at biogeochemical equilibrium. Copyright ?? 2011 The Author(s). Journal compilation ?? 2011 National Ground Water Association.

  4. 21 CFR 524.1580e - Nitrofurazone ointment with butacaine sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Nitrofurazone ointment with butacaine sulfate. 524... ANIMAL DRUGS § 524.1580e Nitrofurazone ointment with butacaine sulfate. (a) Specifications. The drug contains 0.2 percent nitrofurazone and 0.5 percent butacaine sulfate in a water-soluble base. (b) Sponsor...

  5. 21 CFR 524.1580e - Nitrofurazone ointment with butacaine sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Nitrofurazone ointment with butacaine sulfate. 524... ANIMAL DRUGS § 524.1580e Nitrofurazone ointment with butacaine sulfate. (a) Specifications. The drug contains 0.2 percent nitrofurazone and 0.5 percent butacaine sulfate in a water-soluble base. (b) Sponsor...

  6. Impact of clay minerals on sulfate-reducing activity in aquifers

    USGS Publications Warehouse

    Wong, D.; Suflita, J.M.; McKinley, J.P.; Krumholz, L.R.

    2004-01-01

    Previous studies have shown that sulfate-reduction activity occurs in a heterogeneous manner throughout the terrestrial subsurface. Low-activity regions are often observed in the presence of clay minerals. Here we report that clays inhibit sulfate reduction activity in sediments and in a pure culture of Desulfovibriovulgaris. Clay minerals including bentonite and kaolinite inhibited sulfate reduction by 70–90% in sediments. Intact clays and clay colloids or soluble components, capable of passing through a 0.2-µm filter, were also inhibitory to sulfate-reducing bacteria. Other adsorbent materials, including anion or cation exchangers and a zeolite, did not inhibit sulfate reduction in sediments, suggesting that the effect of clays was not due to their cation-exchange capacity. We observed a strong correlation between the Al2O3content of clays and their relative ability to inhibit sulfate reduction in sediments (r2 = 0.82). This suggested that inhibition might be a direct effect of Al3+ (aq) on the bacteria. We then tested pure aluminum oxide (Al2O3) and showed it to act in a similar manner to clay. As dissolved aluminum is known to be toxic to a variety of organisms at low concentrations, our results suggest that the effects of clay on sulfate-reducing bacteria may be directly due to aluminum. Thus, our experiments provide an explanation for the lack of sulfate-reduction activity in clay-rich regions and presents a mechanism for the effect.

  7. Identification of a sulfate metabolite of PCB 11 in human serum

    PubMed Central

    Grimm, Fabian A.; Lehmler, Hans-Joachim; Koh, Wen Xin; DeWall, Jeanne; Teesch, Lynn M.; Hornbuckle, Keri C.; Thorne, Peter S.; Robertson, Larry W.; Duffel, Michael W.

    2016-01-01

    Despite increasing evidence for a major role for sulfation in the metabolism of lower-chlorinated polychlorinated biphenyls in vitro and in vivo, and initial evidence for potential bioactivities of the resulting sulfate ester metabolites, the formation of PCB sulfates in PCB exposed human populations had not been explored. The primary goal of this study was to determine if PCB sulfates, and potentially other conjugated PCB derivatives, are relevant classes of PCB metabolites in the serum of humans with known exposures to PCBs. In order to detect and quantify dichlorinated PCB sulfates in serum samples of 46 PCB-exposed individuals from either rural or urban communities, we developed a high-resolution mass spectrometry-based protocol using 4-PCB 11 sulfate as a model compound. The method also allowed the preliminary analysis of these 46 human serum extracts for the presence of other metabolites, such as glucuronic acid conjugates and hydroxylated PCBs. Sulfate ester metabolites derived from dichlorinated PCBs were detectable and quantifiable in more than 20 % of analyzed serum samples. Moreover, we were able to utilize this method to detect PCB glucuronides and hydroxylated PCBs, albeit at lower frequencies than PCB sulfates. Altogether, our results provide initial evidence for the presence of PCB sulfates in human serum. Considering the inability of previously employed analytical protocols for PCBs to extract these sulfate ester metabolites and the concentrations of these metabolites observed in our current study, our data support the hypothesis that total serum levels of PCB metabolites in exposed individuals may have been underestimated in the past. PMID:27816204

  8. SULFATE REDUCTION IN GROUNDWATER: CHARACTERIZATION AND APPLICATIONS FOR REMEDIATION

    PubMed Central

    Miao, Z.; Brusseau, M. L.; Carroll, K. C.; Carreón-Diazconti, C.; Johnson, B.

    2013-01-01

    Sulfate is ubiquitous in groundwater, with both natural and anthropogenic sources. Sulfate reduction reactions play a significant role in mediating redox conditions and biogeochemical processes for subsurface systems. They also serve as the basis for innovative in-situ methods for groundwater remediation. An overview of sulfate reduction in subsurface environments is provided, along with a brief discussion of characterization methods and applications for addressing acid mine drainage. We then focus on two innovative, in-situ methods for remediating sulfate-contaminated groundwater, the use of zero-valent iron (ZVI) and the addition of electron-donor substrates. The advantages and limitations associated with the methods are discussed, with examples of prior applications. PMID:21947714

  9. A Geochemical and Mineralogical Model for Formation of Layered Sulfate Deposits at Meridiani Planum by Hydrothermal Acid-sulfate Alteration of Pyroclastic Basalt

    NASA Astrophysics Data System (ADS)

    McCollom, T. M.; Hynek, B. M.

    2012-12-01

    The Mars Exploration Rover (MER) Opportunity has extensively characterized sulfate-rich, hematite-bearing bedrock exposed at Meridiani Planum, Mars. Based on various measurements, the mineral composition of the bedrocks has been interpreted to include: amorphous silica/glass/phyllosilicates, Mg-, Ca-, and Fe-bearing sulfates including jarosite, minor amounts of igneous phases including plagioclase, pyroxene, olivine, and magnetite, and hematite [1,2]. Chemically, the bedrocks closely resemble the composition of pristine martian basalt with addition of S and O, and minor variations of Mg and Cl with depth [3,4]. Based on these and other observations, the MER team has proposed that the bedrocks represent chemically altered siliciclastic sediments combined with sulfate salts formed by evaporation of sulfate-bearing fluids, modified by transport and multiple stages of infiltrating groundwater [3,5]. Several alternative scenarios have been proposed for the origin of the rocks including large impacts [6], evaporating glacial deposits [7], acid-fog alteration [8], and hydrothermal acid-sulfate alteration of basalt [4]. In order to further evaluate the potential contribution of hydrothermal proceeses to the deposits, we performed numerical geochemical models of acid-sulfate alteration of martian basalt based on constraints provided by recent laboratory experiments. Experimental studies of alteration of basalt conducted in our lab [9] indicate that the initial stages of acid-sulfate alteration of pyroclastic basalt are characterized by rapid decomposition of igneous crystalline phases including plagioclase, pyroxene, and olivine, while the glass (and igneous phases protected within the glass) remain unreactive. Elements released by dissolving minerals are precipitated primarily as amorphous silica and Ca-, Al-, Fe- and Mg-bearing sulfates, while precipitation of phyllosilicates and Fe-oxides/oxyhydroxides (FeOx) is kinetically inhibited. Based on these constraints, models

  10. Gastrointestinal and microbial responses to sulfate-supplemented drinking water in mice.

    PubMed

    Deplancke, Bart; Finster, Kai; Graham, W Vallen; Collier, Chad T; Thurmond, Joel E; Gaskins, H Rex

    2003-04-01

    There is increasing evidence that hydrogen sulfide (H2S), produced by intestinal sulfate-reducing bacteria (SRB), may be involved in the etiopathogenesis of chronic diseases such as ulcerative colitis and colorectal cancer. The activity of SRB, and thus H2S production, is likely determined by the availability of sulfur-containing compounds in the intestine. However, little is known about the impact of dietary or inorganic sulfate on intestinal sulfate and SRB-derived H2S concentrations. In this study, the effects of short-term (7 day) and long-term (1 year) inorganic sulfate supplementation of the drinking water on gastrointestinal (GI) sulfate and H2S concentrations (and thus activity of resident SRBs), and the density of large intestinal sulfomucin-containing goblet cells, were examined in C3H/HeJBir mice. Additionally, a PCR-denaturing gradient gel electrophoresis (DGGE)-based molecular ecology technique was used to examine the impact of sulfate-amended drinking water on microbial community structure throughout the GI tract. Average H2S concentrations ranged from 0.1 mM (stomach) to 1 mM (cecum). A sulfate reduction assay demonstrated in situ production of H2S throughout the GI tract, confirming the presence of SRB. However, H2S generation and concentrations were greatest in the cecum and colon. Sulfate supplementation of drinking water did not significantly increase intestinal sulfate or H2S concentrations, suggesting that inorganic sulfate is not an important modulator of intestinal H2S concentrations, although it altered the bacterial profiles of the stomach and distal colon of 1-year-old mice. This change in colonic bacterial profiles may reflect a corresponding increase in the density of sulfomucin-containing goblet cells in sulfate-supplemented compared with control mice.

  11. Specific sulfation and glycosylation—a structural combination for the anticoagulation of marine carbohydrates

    PubMed Central

    Pomin, Vitor H.; Mourão, Paulo A. S.

    2014-01-01

    Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans (SFs), sulfated galactans (SGs) and glycosaminoglycans (GAGs). The structural combinations necessary for the anticoagulant activities are the 2-sulfation in α-L-SGs, the 2,4-di-sulfation in α-L-fucopyranosyl units found as composing units of certain sea-urchin and sea-cucumber linear SFs, or as branching units of the fucosylated chondroitin sulfate, a unique GAG from sea-cucumbers. Another unique GAG type from marine organisms is the dermatan sulfate isolated from ascidians. The high levels of 4-sulfation at the galactosamine units combined with certain levels of 2-sulfation at the iduronic acid units is the anticoagulant structural requirements of these GAGs. When the backbones of red algal SGs are homogeneous, the anticoagulation is proportionally dependent of their sulfation content. Finally, 4-sulfation was observed to be the structural motif required to enhance the inhibition of thrombin via heparin cofactor-II by invertebrate SFs. PMID:24639954

  12. Physiochemical properties of alkylaminium sulfates: hygroscopicity, thermostability, and density.

    PubMed

    Qiu, Chong; Zhang, Renyi

    2012-04-17

    Although heterogeneous interaction of amines has been recently shown to play an important role in the formation and growth of atmospheric aerosols, little information is available on the physicochemical properties of aminium sulfates. In this study, the hygroscopicity, thermostability, and density of alkylaminium sulfates (AASs) have been measured by an integrated aerosol analytical system including a tandem differential mobility analyzer and an aerosol particle mass analyzer. AAS aerosols exhibit monotonic size growth at increasing RH without a well-defined deliquescence point. Mixing of ammonium sulfate (AS) with AASs lowers the deliquescence point corresponding to AS. Particles with AASs show comparable or higher thermostability than that of AS. The density of AASs is determined to be 1.2-1.5 g cm(-3), and an empirical model is developed to predict the density of AASs on the basis of the mole ratio of alkyl carbons to total sulfate. Our results reveal that the heterogeneous uptake of amines on sulfate particles may considerably alter the aerosol properties. In particular, the displacement reaction of alkylamines with ammonium sulfate aerosols leads to a transition from the crystalline to an amorphorous phase and an improved water uptake, considerably enhancing their direct and indirect climate forcing.

  13. High Magnetic Susceptibility in a Highly Saline Sulfate-Rich Aquifer Undergoing Biodegradation of Hydrocarbon Results from Sulfate Reduction.

    NASA Astrophysics Data System (ADS)

    Atekwana, E. A.; Enright, A.; Ntarlagiannis, D.; Slater, L. D.; Bernier, R.; Beaver, C. L.; Rossbach, S.

    2016-12-01

    We investigated the chemical and stable carbon isotope composition of groundwater in a highly saline aquifer contaminated with hydrocarbon. Our aim to evaluate hydrocarbon degradation and to constrain the geochemical conditions that generated high anomalous magnetic susceptibility (MS) signatures observed at the water table interface. The occurrence of high MS in the water table fluctuating zone has been attributed to microbial iron reduction, suggesting the use of MS as a proxy for iron cycling. The highly saline aquifer had total dissolved solids concentrations of 3.7 to 29.3 g/L and sulfate concentrations of 787 to 37,100 mg/L. We compared our results for groundwater locations with high hydrocarbon contamination (total petroleum hydrocarbon (TPH) >10 mg/L), at lightly contaminated (TPH <10 mg/L) and locations with no contaminations. Our results for the terminal electron acceptors (TEAs) dissolved oxygen (DO), nitrate (NO3-), dissolved iron (Fe2+) , dissolved manganese (Mn2+), sulfate (SO42-) and methane (CH4) suggest a chemically heterogeneous aquifer, probably controlled by heterogeneous distribution of TEAs and contamination (type of hydrocarbon, phase and age of contamination). The concentrations of dissolved inorganic carbon (DIC) ranged from 67 to 648 mg C/L and the stable carbon isotope (δ13CDIC) ranged from -30.0‰ to 1.0 ‰ and DIC-δ13CDIC modeling indicates that the carbon in the DIC is derived primarily from hydrocarbon degradation. The concentrations of Fe2+ in the aquifer ranged from 0.1 to 55.8 mg/L, but was mostly low, averaging 2.7+10.9 mg/L. Given the low Fe2+ [AE1] in the aqueous phase and the high MS at contaminated locations, we suggest that the high MS observed does not arise from iron reduction but rather from sulfate reduction. Sulfate reduction produces H2S which reacts with Fe2+ to produce ferrous sulfide (Fe2+S) or the mixed valence greigite (Fe2+Fe3+2S4). We conclude that in highly saline aquifers with high concentrations of sulfate

  14. Endothelial Heparan Sulfate 6-O-Sulfation Levels Regulate Angiogenic Responses of Endothelial Cells to Fibroblast Growth Factor 2 and Vascular Endothelial Growth Factor*

    PubMed Central

    Ferreras, Cristina; Rushton, Graham; Cole, Claire L.; Babur, Muhammad; Telfer, Brian A.; van Kuppevelt, Toin H.; Gardiner, John M.; Williams, Kaye J.; Jayson, Gordon C.; Avizienyte, Egle

    2012-01-01

    Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor 165 (VEGF165) are potent pro-angiogenic growth factors that play a pivotal role in tumor angiogenesis. The activity of these growth factors is regulated by heparan sulfate (HS), which is essential for the formation of FGF2/FGF receptor (FGFR) and VEGF165/VEGF receptor signaling complexes. However, the structural characteristics of HS that determine activation or inhibition of such complexes are only partially defined. Here we show that ovarian tumor endothelium displays high levels of HS sequences that harbor glucosamine 6-O-sulfates when compared with normal ovarian vasculature where these sequences are also detected in perivascular area. Reduced HS 6-O-sulfotransferase 1 (HS6ST-1) or 6-O-sulfotransferase 2 (HS6ST-2) expression in endothelial cells impacts upon the prevalence of HS 6-O-sulfate moieties in HS sequences, which consist of repeating short, highly sulfated S domains interspersed by transitional N-acetylated/N-sulfated domains. 1–40% reduction in 6-O-sulfates significantly compromises FGF2- and VEGF165-induced endothelial cell sprouting and tube formation in vitro and FGF2-dependent angiogenesis in vivo. Moreover, HS on wild-type neighboring endothelial or smooth muscle cells fails to restore endothelial cell sprouting and tube formation. The affinity of FGF2 for HS with reduced 6-O-sulfation is preserved, although FGFR1 activation is inhibited correlating with reduced receptor internalization. These data show that 6-O-sulfate moieties in endothelial HS are of major importance in regulating FGF2- and VEGF165-dependent endothelial cell functions in vitro and in vivo and highlight HS6ST-1 and HS6ST-2 as potential targets of novel antiangiogenic agents. PMID:22927437

  15. Photoluminescence properties of Eu3+ doped HfO2 coatings formed by plasma electrolytic oxidation of hafnium

    NASA Astrophysics Data System (ADS)

    Stojadinović, Stevan; Tadić, Nenad; Ćirić, Aleksandar; Vasilić, Rastko

    2018-03-01

    Plasma electrolytic oxidation was used for synthesis of Eu3+ doped monoclinic HfO2 coatings on hafnium substrate. Results of photoluminescence (PL) measurements show the existence of two distinct regions: one that is related to the blue emission originating from oxygen vacancy defects in HfO2 and the other one characterized with a series of sharp orange-red emission peaks related to f-f transitions of Eu3+ from excited level 5D0 to lower levels 7FJ (J = 0, 1, 2, 3, and 4). PL peaks appearing in excitation spectra of obtained coatings are attributed either to charge transfer state of Eu3+ or to direct excitation of the Eu3+ ground state 7F0 into higher levels of the 4f-manifold. PL of formed coatings increases with PEO time due to an increase of oxygen vacancy defects and the content of Eu3+. Acquired experimental data suggest that hypersensitive electrical dipole transition is much more intense than the magnetic dipole transition, indicating that Eu3+ ions occupy a non-inversion symmetry sites.

  16. 40 CFR 721.1500 - 1,2-Benzenediamine, 4-ethoxy, sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1,2-Benzenediamine, 4-ethoxy, sulfate... Substances § 721.1500 1,2-Benzenediamine, 4-ethoxy, sulfate. (a) Chemical substance and significant new use...-benzenediamine, 4-ethoxy, sulfate, PMN P-83-105. (2) The significant new use is: Manufacture, import, or...

  17. 40 CFR 721.1500 - 1,2-Benzenediamine, 4-ethoxy, sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1,2-Benzenediamine, 4-ethoxy, sulfate... Substances § 721.1500 1,2-Benzenediamine, 4-ethoxy, sulfate. (a) Chemical substance and significant new use...-benzenediamine, 4-ethoxy, sulfate, PMN P-83-105. (2) The significant new use is: Manufacture, import, or...

  18. 40 CFR 721.1500 - 1,2-Benzenediamine, 4-ethoxy, sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 1,2-Benzenediamine, 4-ethoxy, sulfate... Substances § 721.1500 1,2-Benzenediamine, 4-ethoxy, sulfate. (a) Chemical substance and significant new use...-benzenediamine, 4-ethoxy, sulfate, PMN P-83-105. (2) The significant new use is: Manufacture, import, or...

  19. 40 CFR 721.1500 - 1,2-Benzenediamine, 4-ethoxy, sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 1,2-Benzenediamine, 4-ethoxy, sulfate... Substances § 721.1500 1,2-Benzenediamine, 4-ethoxy, sulfate. (a) Chemical substance and significant new use...-benzenediamine, 4-ethoxy, sulfate, PMN P-83-105. (2) The significant new use is: Manufacture, import, or...

  20. 40 CFR 721.1500 - 1,2-Benzenediamine, 4-ethoxy, sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1,2-Benzenediamine, 4-ethoxy, sulfate... Substances § 721.1500 1,2-Benzenediamine, 4-ethoxy, sulfate. (a) Chemical substance and significant new use...-benzenediamine, 4-ethoxy, sulfate, PMN P-83-105. (2) The significant new use is: Manufacture, import, or...