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Sample records for sulfate monocrystals studied

  1. Jahn-Teller glass formation in beta-lithium ammonium sulfate monocrystals studied by means of the electron paramagnetic resonance of Mn sup 2 sup + and Cu sup 2 sup + ions

    Waplak, S

    2002-01-01

    The EPR (electron paramagnetic resonance) spectra of non-Jahn-Teller (JT) Mn sup 2 sup + and JT Cu sup 2 sup + ions have been studied for alpha- or beta-LAS structure modification in the temperature range of 4.2-480 K. The experimental evidence for JT glass with frozen-in random strain fields due to the presence of the JT Cu sup 2 sup + ions is presented.

  2. Manufacturing tungsten monocrystal tubes by electro-spark machining and study of machined surface structure

    Abdukarimov, Eh.T.; Ismailov, L.R.; Krakhmalev, V.A.; Fershtat, L.N.

    1981-01-01

    A technique to manufacture tubes from tungsten monocrystals with low consumption of electrodes has been developed. Regimes of obtaining deep and through holes of different diameters with the productivity of 1 mm/min and with the minimum deviation from cylindrical shape are worked out using a specially designed electric pulse installation. X-ray and metallographical analyses have shown that as a result of electrospark machining a cold hardened layer is formed up to hundreds micrometers thick, pierced by the network of microcracks. Simultaneous use of electrospark and electrochemical machining permitted to manufacture tubes from tungsten monocrystals with non-distorted monocrystal surface and without a network of microcracks

  3. Study on radiation-induced defects in germanium monocrystals by the X-ray diffusive scattering method

    Malinenko, I.A.; Perelygina, E.A.; Chudinova, S.A.; Shivrin, O.N.

    1979-01-01

    The method of X-ray diffusion scattering was used to study the defective structure of germanium monocrystals exposed to 750 keV proton irradiation with 3.8x10 16 -4.6x10 17 cm -2 doses and subjected to the subsequent annealing at temperatures up to 450 deg C. Detected in the crystals were the complex radiation induced structure characterized with oriented vacancy complexes and results from the both effects: irradiation and annealing. Radiation defect sizes in the section (hhO) have been determined. With increasing the annealing temperature the structure reconstruction resulting in the complex dissociation is observed

  4. Gap energy studied by optical transmittance in lead iodide monocrystals grown by Bridgman's Method

    Veissid N.

    1999-01-01

    Full Text Available The bandgap energy as a function of temperature has been determined for lead iodide. The monocrystal was obtained in a vacuum sealed quartz ampoule inside a vertical furnace by Bridgman's method. The optical transmittance measurement enables to evaluate the values of Eg. By a fitting procedure of Eg as a function of temperature is possible to extract the parameters that govern its behavior. The variation of Eg with temperature was determined as: Eg(T = Eg(0 - aT2/(a + T, with: Eg(0 = (2.435 ± 0.008 eV, a = (8.7 ± 1.3 x 10-4 eV/K and a = (192 ± 90 K. The bandgap energy of lead iodide at room temperature was found to be 2.277 ± 0.007 eV.

  5. Study of thin films and V2O3 monocrystals in the range of phase transformations by the method of the surface acoustic waves

    Boborykina, E.N.; Nikitin, S.E.; Chudnovskij, F.A.

    1995-01-01

    A study was made on acoustic-electron interaction in films and V 2 O 3 monocrystals in 80-450 K range, including the region of metal-antiferromagnetic insulator phase transformation (PTM↔AFI) and the region of high-temperature anomalies. Temperature dependences of absorption and change of surface acoustic wave (SAW) velocity were measured. The maximum on temperature dependences of absorption and change of SAW velocity in the region of PTM↔AFI was revealed. 9 refs.; 4 figs

  6. A method for manufacturing monocrystals

    Faure, Jacqueline; Malmejac, Yves; Schaub, Bernard.

    1973-01-01

    Description is given of a method for manufacturing monocrystals, substantially free of disorder, of a metal showing an allotropic transformation at a temperature lower than its melting point. Monocrystals of the raw metal having undergone a uni-directional solidification are heated to a temperature between the allotropic transformation point and the metal melting point; the monocrystals are maintained in the vicinity of that temperature for a given period of time; they are cooled down to a temperature lower than the allotropic transformation point, then they are annealed and cooled down to room temperature. Such monocrystals are used in neutron monochromators [fr

  7. Synthesis and some properties of monocrystals. [Monocrystals-SbTiNbO6

    Popolitov, V I; Yaroslavskij, I M

    1985-01-01

    The Sb2O3-Nb2O5-TiO2- KHF2-H2O2-H2O system was studied in search for new ferroelectric monocrystals containing oxide forms of antimony, niobium and tantalum. The new compounds were synthesized in batch autoclaves at 500-600 deg, temperature gradient along the vertical autoclave axis being 0.2-0.5 degr/cm. The SbTiNbO6 monocrystals formed as a result of hydrothermal synthesis are assigned to rhombic crystal structure, their electric conductivity and dielectric permittivity at room temperature are 10 S xcm and 75, respectively. Differential thermal analysis of samples has shown the presence of phase transformation in them in the 270 to 280 range. Pyroelectric effect has been observed in monocrystals in the -180 to +280 deg range. The synthesized antimony titaniobate is concluded to be a ferroelectric with the Curie point Tsub(C)=280 +- 10 deg.

  8. Synthesis, structural and physico-chemical studies of the monocrystal superconductor oxides Hg Ba2 Can-1 Cun O2n+2+δ

    Viallet-Guillen, Virginie

    1998-01-01

    The thesis presents the synthesis and the structural and physico-chemical properties of the mercury-based monocrystal superconductor oxides. The results reported in the first chapter refer to the first three members of the mercury cuprate series Hg-1201, Hg-1212 and Hg-1223. In the second chapter detailed results concerning the structure of these compounds are given highlighting the features common to all cuprates and pointing out the peculiarities of mercury phases. The third chapter presents the phase diagrams (δ, T, p(O 2 )) of the compounds HgBa 2 CuO 4+δ and HgBa 2 Ca 2 Cu 3 O 8+δ obtained by thermogravimetry under controlled atmosphere between 150 deg.C and 500 deg.C and thermodynamic equilibrium conditions. In the case of Hg-1201, the critical temperature shows a variation close to a parabolic law, with an optimal Tc of 96 K (δ≅0.10) while in Hg-1223 the Tc increases linearly with the O content up to the optimal Tc of 135 K (δ≅0.19) and decreases only by 2 K in the over-doped regime. Finally, in the fourth chapter different physical properties are reviewed. The obtained monocrystals allowed studying the resistive transitory anisotropy, the torque, the specific heat, the nuclear magnetic resonance and the Raman diffusion

  9. Studies of a nitroxide radical by EPR in monocrystal: interaction of protons and electronic relaxation

    Alonso, A.

    1986-01-01

    The ESR spectra of a nitroxide radical, 4-hydroxi-2,2,6,6-tetramethylpiperidine-1-oxyl (TANOL II), introduced as impurity in a diamagnetic host, 4-hydroxi-2,6,6-tetramethylpiperedine (I), were investigated. The use of deuterated radical, 4-hydroxi-2,2,6,6 tetramethylpiperidine-d sub(17) -1, oxyl (PD-TANOL, III) improved the resolution of ESR spectra for most of orientations of magnetic field. The proton interqactions in the neighbourhood of magnetic group N-O were studied and superpyresfine tensors for two strongly coupled protons were determined. In order to study the influence of protons on electronic relaxation of radicals, the relaxation times T sub(1) and T sub(2) were estimated in the temperature range-160 sup(0)C - 25 sup(0)C for several orientations, and comparing data for protonated and deuterated radicals II and III, using the continuous wave saturation method. (author)

  10. Radiation effects in corundum monocrystal

    Soulayman, S.; Attiah, J.; Molhem, A. G.

    2007-01-01

    It is found by this work that the irradiation of corundum monocrystals by energetic particles creates stable lattice defects, as a result of the atomic displacements to the sublattice. We have identified the colour centers (F and F + ) and more complex ones line [Al i + F]. This finding is in an agreement with the experimental results, available in the literature. We have also investigated the mechanism of occurrence of, so called 'radiation memory' in corundum monocrystals. This phenomenon reflects the fact that, after irradiation and annealing at high temperature and irradiation again by the quanta of x-rays, the absorption line 302 nm (4.1 eV) in the spectrum of optical absorption is restored in the range 200-650 nm. A comparison of our results with the results of other researchers in carried out. (author)

  11. The use of anions with sulfate function in electrolyte for lithium battery. Study of transport mechanism; Utilisation d'anions a fonction sulfate dans des electrolytes pour batterie au lithium. Etude des mecanismes de transport

    Chauvin, Ch.

    2005-05-15

    Lithium salts based on oligo-ether sulfate were synthesized and characterised. They incorporate oxy-ethylene units which enable the lithium cation salvation and, potentially, their use as ionic liquids. Their properties as lithium salts dissolved in liquid or polymer electrolytes were evaluated. Their electrochemical and thermal stabilities are sufficient for lithium battery application. Due to their weak dissociation in POE, their conductivities are fairly low. On the other hand, they have high cationic transference numbers. In mixture with usual salts as LiTFSI, they provide a good compromise between conductivities/transference number/cost. The second part of this study deals with the synthesis and characterisation of an ionomer with sulfate function and polyether backbone. The electrochemical, physical and chemical properties of this material show that it could be used as polymer electrolyte. Its potential as cross-linked gelled polymer electrolyte is outstanding. Structural analyses on an ionomeric monocrystal have been corroborated with quantum chemistry calculations. (author)

  12. Fracture mechanics and physics approach to cleavage analysis in bcc monocrystals

    Ivanova, V.S.; Plastinin, V.M.

    1980-01-01

    On monocrystals of molybdenum obtained by electron--beam zone melting studied are the bonds between micro-and macroparameters of fracture controlling the limit state. Monocrystals of three orientations have been studied, namely >001 110 111<. Confirmed is an important role of plastic deformation in the (110) family planes at cleavage forming in the (100) family planes. A correlation connection is established between threshold value of the stress intensity coefficient and activation energy of plastic deformation

  13. Contribution to the study of the effects produced by irradiation and doping on LiF monocrystals

    Lima, Luis Filipe C.P. de

    1975-01-01

    The effects of neutron irradiation in pure and Mg doped LiF single crystals have been studied by combining internal friction and ionic thermo conductivity techniques. The main results of internal friction measurements in irradiated samples are: 1)a relaxation peak characteristic of inelastic relaxation processes is detected in pure samples exposed to fast and thermal neutrons in a swimming pool reactor. The nuclear reaction 6 Li (n,alpha)T is taken into account to explain the production of defects responsible for the detected relaxation peak because that process is not observed in experiments with pure sample shielded from thermal neutrons; 2) no Internal Friction relaxation peak is detected in Mg doped samples under the same experimental conditions; 3) It was not possible to determine an activation energy and a fundamental relaxation time for the defects responsible for the relaxation peak mentioned above because it was found that peak is not a Debye peak. Experiments, to determine the influence- of stress in Mg doped LiF crystals in torsion and in torsion-flexion configurations in the Internal Friction apparatus have also been performed. With the second experimental set-up an Internal Friction peak is detected leading to conclude that there is an Interaction between the flexion component with the Mg 2+ cation vacancy -elastic dipoles. Ionic Thermo conductivity measurements in LiF:Mg yielded for the parameters of the Mg 2+ cation vacancy pair the following values: fundamental relaxation, time τ 0 (5 +-2) x 10 -14 s and activation energy E = (0,65 + 0,02) eV. These results are in good agreement with the ones obtained In other laboratories. The effect of neutron irradiation on the concentration of Mg - cation vacancy pairs was to reduce that concentration. Moreover, two new depolarization current peaks are detected for neutron fluences higher than approximately 10 17 n/cm 2 . The relaxation parameters of one of these peaks (the lower temperature one) were

  14. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    LI, LIANG; Zhang, Jianqin; Sun, Xun; Zhang, Qiang; Zhao, Xian; Zhang, Xixiang

    2013-01-01

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property

  15. Neutron Transmission of Germanium Poly- and Monocrystals

    Habib, N.

    2009-01-01

    The measured total neutron cross-sections of germanium poly- and mono-crystals were analyzed using an additive formula. The formula takes into account the germanium crystalline structure and its physical parameters. Computer programs have developed in order to provide the required analyses. The calculated values of the total cross-section of polycrystalline germanium in the neutron wavelength range from 0.001 up to 0.7 nm were fitted to the measured ones at ETRR-1. From the fitting the main constants of the additive formula were determined. The experimental data measured at ETRR-1 of the total cross-section of high quality Ge single crystal at 4400 K, room, and liquid nitrogen temperatures, in the wavelength range between 0.028 nm and 0.64 nm, were also compared with the calculated values using the formula having the same constants. An overall agreement is noticed between the formula fits and experimental data. A feasibility study is done for the use of germanium in poly-crystalline form, as cold neutron filter, and in mono-crystalline one as an efficient filter for thermal neutrons. The filtering efficiency of Ge single crystal is detailed in terms of its isotopic abundance, crystal thickness, mosaic spread, and temperature. It can be concluded that the 7.5 cm thick 76 Ge single crystal (0.10 FWHM mosaic spread) cooled at liquid nitrogen temperature is an efficient thermal neutron filter.

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

    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.

  17. Radiation-electromagnetic effect in germanium monocrystals

    Kikoin, I.K.; Kikoin, L.I.; Lazarev, S.D.

    1980-01-01

    Experimentally investigated is the radiation-electromagnetic effect (REM) in germanium monocrystals on excitation of excess current carriers by α particles, protons and X-rays in magnetic fields up to 8 kOe. A cyclotron was used as an α particle source, and a standard X-ray tube with a copper anode - as an X-ray source. The e.m.f. of the REM effect linearly increases with the increase of the magnetic field and is proportional to the charged particle flux at small flux values, saturation occurs at great flux values (approximately 5x10 11 part./cm 2 xs). In the 4-40 MeV energy range the e.m.f. of the REM effect practically does not depend on the α particle energy. On irradiation of the samples with a grinding front surface the REM e.m.f. changes its sign. The REM and Hall effect measurement on α particle irradiated samples has shown that during irradiation a p-n transition is formed in the samples, which must be taken into account while studying the REM effect. The e.m.f. measured for the even REM effect quadratically increases with the magnetic field increase. The barrier radiation-voltaic effect (the effect e.m.f. is measured between the irradiated and nonirradiated sample faces) is studied. Using special masks the samples with a set of consecutive p-n transitions are produced by irradiation of germanium crystals by α particles. Investigation of the photovoltaic and photoelectromagnetic effects on such samples has shown that using this method the efficiency of the REM devices can be increased

  18. Moessbauer study of hydrated iron sulfates

    Araujo, S.I.; Danon, J.; Iannarella, L.

    1991-01-01

    The hydrated iron sulfates amarantite Fe(SO sub(4))(OH).3H sub(2)O, copiapite (Mg,Al)Fe sup(3+) sub(4)(SO sub(4)) sub(6)(OH) sub(2).20H sub(2)O and ungemachite K sub(3)Na sub(9)Fe(SO sub(4)) sub(6)(OH) sub(3).9H sub(2)O were studied by Moessbauer Spectroscopy (MS) in connection with Differential Scanning Calorimetry (DSC). The effect of the dehydration on the hyperfine parameters at the Fe sites was investigated. For amarantite, the Moessbauer spectrum remained practically unchanged, while the Fe sup(3+) quadrupole splittings for copiapite and ungemachite increased. The Fe sup(2+) quadrupole splitting of ungemachite was also unchanged. We have found out the anisotropy of the recoiless absorption probability for the sup(57)Fe Moessbauer gamma ray in amarantite. The three minerals were found to be highly hygroscopic after the dehydration consequent of the DSC measurements. (author)

  19. Transfer phenomena in p-PbTe monocrystals grown under zero-g conditions

    Regel', L.L.; Rakhmatov, O.I.; Red'ko, N.A.; Parfen'ev, R.V.; AN SSSR, Leningrad. Fiziko-Tekhnicheskij Inst.)

    1984-01-01

    The purpose of the study is comparative investigation of low-temperature phenomena of charge and heat transfer in p-PbTe monocrystals grown by the method of oriented crystallization under zero-g conditions as well as under terrestrial conditions at identical technological regimes. Investigation of thermal conductivity a strong magnetic field permits to separate lattice and electron thermal conductivity components, the latter constituting 6% of total thermal conductivity. Therefore the predominant contribution to kappa(T) is made by the lattice thermal conductivity which turned to be close by value for both samples. This points to identical character of structural perfection of p-PbTe investigated monocrystals

  20. Effect of hydrostatic pressure on magnetic phase transitions and magnetization in gadolinium monocrystal

    Nikitin, S.A.; Bezdushnyj, R.V.

    1989-01-01

    Effect of hydrostatic pressure on magnetization in gadolinium monocrystal (Δσ-effect) was investigated. Dependences of spesific magnetization, Δσ-effect and bulk magnetostriction of gadolinium monocrystal on temperatures were studied. Results of conducted investigation have shown that in gadolinium the change of specific magnetization under the hydrostatic pressure effect is caused in general case by three effects: a)change of spontaneous magnetization under the effect of hydrostatic pressure; b)change of magnetization within technical magnetization range due to the effect of hydrostatic pressure on magnetic anisotropy constants; c)change of magnetization due to the effect of hydrostatic pressure on temperature of spin-reoriented transition

  1. Russian plant grows monocrystals for CERN collider

    2003-01-01

    "..Experts of an enterprise in Murmansk Region has started to make so-called monocrystals. They are needed for making of a huge device the construction of which has started in Switzerland. Thanks to this unique equipment scientists of the European Organization for Nuclear Research (CERN) will be able to model the creation of the universe for the first time ever" (1/2 page).

  2. Bulk monocrystal growth, optical, dielectric, third order nonlinear, thermal and mechanical studies on HCl added L-alanine: An organic NLO material

    Shkir, Mohd, E-mail: shkirphysics@gmail.com [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Physics Department, Faculty of Science, King Khalid University, Abha (Saudi Arabia); Yahia, I.S., E-mail: dr_isyahia@yahoo.com [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Physics Department, Faculty of Science, King Khalid University, Abha (Saudi Arabia); Nano-Science & Semiconductor Labs, Physics Department, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Al-Qahtani, A.M.A. [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Physics Department, Faculty of Science, King Khalid University, Abha (Saudi Arabia)

    2016-12-01

    In the current work, good quality bulk size (∼32 mm × 23 mm × 10 mm) single crystals of HCl added L-alanine with well-defined morphology are successfully grown using slow evaporation technique. Crystal structure and other structural parameters were evaluated from X-ray diffraction data. Vibrational assessment of the grown crystal was done by FT-Raman analysis. The presence of chlorine and good quality of the grown crystal was confirmed by SEM/EDX analysis. Solid state UV–Vis–NIR diffused reflectance was measured and direct and indirect optical band gap was calculated using Kubelka-Munk relation and found to be 5.64 and 5 eV respectively. Dielectric measurement was carried out in high frequency range. Third order nonlinear optical susceptibility value was found to be enhanced from 1.91 × 10{sup −6} (pure) to 8.6 × 10{sup −6} esu (LAHCl). Good thermal stability of grown crystals was confirmed from DSC analysis. The enhancement in mechanical strength and crystalline perfection was also observed. - Highlights: • Bulk size (32 mm × 23 mm × 10 mm), good crystalline perfection HCl added L-alanine monocrystal is grown. • The shift in X-ray diffraction and vibrational peaks confirms the interaction of HCl. • The high optical transparency and band gap confirms its application in optoelectronic devices. • Third order NLO properties are found to be enhanced in HCl added L-alanine crystals. • The mechanical strength of the grown crystals is found to be enhanced due HCl addition.

  3. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    LI, LIANG

    2013-04-18

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property in the ultraviolet region which confirms and agrees well with former results. © 2013 Astro Ltd.

  4. Contribution to the radio crystallographic study of the effect of neutrons on LiF monocrystals (1962); Contribution a l'etude radiocristallographique de l'effet des neutrons sur les monocristaux de LiF (1962)

    Dubois, M; Tournarie, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    We have studied the changes in the 200 and 400 reflections in LiF monocrystals irradiated by neutrons, for doses of between 10{sup 17} and 10{sup 18} n/cm{sup 2}. The reflections are distinctly dissymmetric and in the case of doses under 5.10{sup 17} appear to consist of a fine peak associated with a wide and diffuse base. These appear to exist organised groups of point defects which lead to perturbed zones whose number varies very little with the irradiation and which exist perhaps beforehand. (authors) [French] Nous avons etudie l'evolution des reflexions 200 et 400 de monocristaux de LiF irradie aux neutrons pour des doses variant de 10{sup 17} a 10{sup 18} n/cm{sup 2}. Les reflexions presentent une nette dissymetrie et pour des doses inferieures a 5.10{sup 17} semblent constituees d'un pic fin associe a une base large et diffuse. Il semble qu'il y ait des rassemblements organises de defauts ponctuels pour donner des zones perturbees dans le nombre varierait peu avec l'irradiation et lui serait peut-etre preexistant. (auteurs)

  5. Studies on sulfate attack: Mechanisms, test methods, and modeling

    Santhanam, Manu

    The objective of this research study was to investigate various issues pertaining to the mechanism, testing methods, and modeling of sulfate attack in concrete. The study was divided into the following segments: (1) effect of gypsum formation on the expansion of mortars, (2) attack by the magnesium ion, (3) sulfate attack in the presence of chloride ions---differentiating seawater and groundwater attack, (4) use of admixtures to mitigate sulfate attack---entrained air, sodium citrate, silica fume, and metakaolin, (5) effects of temperature and concentration of the attack solution, (6) development of new test methods using concrete specimens, and (7) modeling of the sulfate attack phenomenon. Mortar specimens using portland cement (PC) and tricalcium silicate (C 3S), with or without mineral admixtures, were prepared and immersed in different sulfate solutions. In addition to this, portland cement concrete specimens were also prepared and subjected to complete and partial immersion in sulfate solutions. Physical measurements, chemical analyses and microstructural studies were performed periodically on the specimens. Gypsum formation was seen to cause expansion of the C3S mortar specimens. Statistical analyses of the data also indicated that the quantity of gypsum was the most significant factor controlling the expansion of mortar bars. The attack by magnesium ion was found to drive the reaction towards the formation of brucite. Decalcification of the C-S-H and its subsequent conversion to the non-cementitious M-S-H was identified as the mechanism of destruction in magnesium sulfate attack. Mineral admixtures were beneficial in combating sodium sulfate attack, while reducing the resistance to magnesium sulfate attack. Air entrainment did not change the measured physical properties, but reduced the visible distress of the mortars. Sodium citrate caused a substantial reduction in the rate of damage of the mortars due to its retarding effect. Temperature and

  6. Preparation, structure and properties of potassium neodymium tetraphosphate monocrystals

    Litvin, B.N.; Dorokhova, G.I.; Filipenko, O.S.

    1981-01-01

    To prepare KNd(PO 3 ) 4 in the form of monocrystals its crystallization in the aqueous solution of phosphoric acid is studied at 280-600 deg C. It is found that tetrapolyphosphate is formed higher than 350 deg C (KNd(P 3 ) 4 ), and lower than the temperature its polymorphous modification (tetrametaphosphate KNd(P 4 O 12 )) is crystallized. The main properties of the crystals of both modifications: habit, density, crystal structure, the Fedorov group, parameters of the elementary cell, refractive indices, interatomic distances, are presented. The life time of the metastable level Ndsup(3+)Esub(3/2) in the crystals prepared is measured. The decrease of life time value with the temperature and concentrational quenching is observed for both modifications [ru

  7. Synchrotron topography of the SrLaGaO4 monocrystals in the white beam

    Malinowska, A.; Lefeld-Sosnowska, M.; Wierzbicka, E.; Wieteska, K.; Wierzchowski, W.; Graeff, W.

    2005-01-01

    Paper presents results of the studies on defects of the crystalline lattice in the SrLaGaO 4 (SLG) monocrystals grown in the Institute of Electronic Materials Technology (ITME), Warsaw (Poland) by the Czochralski method. Studies were performed in the F1 station of the HASYLAB (Desy, Hamburg) using the synchrotron projecting and the sectional topography in the white beam, both transmission and reflection modes. Nature of the defects appearing in the SLG crystals remains unclear and needs further studies [pl

  8. Real structure of LaGaO3 monocrystals grown by Czochralski method

    Morozov, A.N.; Morozova, O.Yu.; Ponomarev, N.M.

    1993-01-01

    A complex X-ray diffraction study of lanthanum (ortho)gallate crystal structure and structural defects in LaGaO 3 crystals grown by the Czochralski method is carried out. Coordinates of atoms in LaGaO 3 unit cell are determined. X-Ray topographic studies of oriented LaGaO 3 sublayers for high-tc superconductor film growth are optimized. The substructure of monocrystals is studied

  9. Low-temperature monocrystal elastic constants of Fe-19Cr-10Ni

    Ledbetter, H.M.

    1984-01-01

    By a pulse-echo-overlap ultrasonic method, we determined the monocrystal elastic constants (C 11 , C 12 , C 44 ) of an Fe-19Cr-10Ni alloy between 295 and 4 K. In composition this laboratory alloy approximates a technological austenitic stainless steel: AISI 304. Many previous studies on polycrystalline steels found a low-temperature magnetic phase transition that affects physical properties, including elastic constants. At the transition, anomalies occur in all polycrystal elastic constants: Young's modulus, shear modulus, bulk modulus, and Poisson's ratio. The present study found that the transition, near 50 K, does not affect one monocrystal elastic constant: C 44 , the resistance to shear on a (100) plane in a [100]-type direction. We interpret this new observation from the viewpoint of a Born-type lattice model. Also, we comment about the relationship between the elastic-constant changes and the low-temperature magnetic state

  10. Rheo-electrical approximate simulation of monocrystal growth from the melt

    Vernois, G.

    1969-01-01

    On a two-dimensional model, the advantages of rheo-electrical simulation for studying monocrystal growth from the melt are pointed out. In the case of an opaque body, it is always possible to make a fairly exact model. As regards a transparent body, the simulation of radiation thermal exchange is fairly difficult. It is shown how the plans of a constant level complex crucible are established. (author) [fr

  11. Absorption of acoustic waves in La3Ga5SiO14 monocrystals

    Mansfel'd, G.D.; Bezdelkin, V.V.; Freik, A.D.; Kucheryavaya, E.S.

    1995-01-01

    Frequency dependences of longitudinal and transverse acoustic wave absorption coefficient in the basic crystallographic La 3 Ga 5 SiO 14 directions are measured by composite resonator method. The obtained values of absorption coefficient for all directions appear to be lower or approximately equal to the values of absorption coefficient in quartz monocrystals. Application of the resonator methods allows one to study factors affecting the resonator high-quality as well. 9 refs., 4 figs

  12. Case study of elevated layers of high sulfate concentration

    McNaughton, D.J.; Orgill, M.M.

    1979-01-01

    During studies in August 1976 that were part of the Multi-State Atmospheric Power Production Pollutant Study (MAP3S), Alkezweeny et al., (1977) noted that in the Milwaukee urban plume, layers of relatively high sulfate concentrations occurred at high altitudes with respect to the boundary layer. This paper represents a progress report on studies undertaken to investigate possible causes for a bimodel vertical profile of sulfate concentrations. Data presented by Alkezweeny et al., (1977) serve as a basis for this study. Data from August 23, 1976, and August 24, 1978, indicate concentrations relatively high in sulfate, at 1000 and 6000 ft, respectively, with lower concentrations at lower altitudes. Concentrations of trace metals also indicate no peaks in the vertical concentration profiles above the surface. Initial studies of the high, elevated sulfate concentrations have centered on the August 23 measurements taken over southeast Wisconsin using synoptic data from the national weather service, emissions data from the national emissions data bank system (EPA), air quality data from the national air surveillance network (EPA), and satellite photographs from the EROS Data Center

  13. Measurement of specific heat of pure and vanadium doped Al2O3 monocrystals at low temperature

    Lagnier, Robert; Villedieu, Michel; Bonjour, Emmanuel.

    1975-01-01

    Within the scope of a study on charge transfer mechanisms in vanadium doped Al 2 O 3 monocrystals, the absolute concentrations of V 3+ ions were determined using Schottky's anomaly of ions, the maximum of which lies around 5K [fr

  14. Phase transition in vortex system in Bi2212:Pb monocrystal

    Uspenskaya, L S; Rakhmanov, A L

    2002-01-01

    Penetration of the magnetic flux into the (Bi sub 0 sub . sub 8 sub 4 Pb sub 0 sub . sub 1 sub 6) sub 2 sub . sub 2 Sr sub 2 CaCu sub 2 O sub 8 high-temperature superconductor monocrystal is studied thorough the magnetooptical method in the crossed magnetic fields. It is shown that the magnetic flux penetration in the low-temperature areas is anisotropic: it moves primarily along the magnetic field, applied in the sample plane, and this anisotropy grows with the temperature growth. At the temperature of T sub m = 54 +- 2 K there takes place sharp change in the character of the magnetic field penetration into the superconductor, whereby the direction of the flux motion discontinues to be dependent on the direction and value of the magnetic field applied in the sample plane. This effect is interpreted within the frames of representations on the phase transition in the vortex system connected with a sharp decrease in the correlations of the vortex position in the different CuO-planes

  15. Study of dosimetric systems-ferrous sulfate-ferric sulfate, glass slides and dyed aqueous solutions

    Fernandes, L.

    1979-01-01

    The effect of some variables which can effect the preparation of the ferrous sulfate used as dosimetric solution has been studied. Among these variables the purity of the water used for the preparation of the solution and the presence (or absence) of oxygen in the dosimetric solution were considered. The dose rate distribution according to the transverse and longitudinal sections of the Co 60 irradiator was studied experimentally, using the dosimetric solution, and theoretically, using a computer program (KIFE). The results obtained with the ferrous sulface dosimetric solution were used as reference for the study of the application of EM and MSG glass slide as a dosimetric system. For this purpose the effects of the weakening of the coloration induced in the glass by gamma rays (Co 60 ) and the relationship between the absorbed dose of radiation and the ratio between the variation in absorbation value and the thickness of the glass irradiated, were studied. A study was also made of the use of the dye indicators bromothymol-blue, methyl-orange, Congo-red, neutral-red and p-nitrophenol, in aqueous solution, for radiation dose measurements. The bleaching of each indicator solution, under gamma-radiation (Co 60 ) was studied in oxygen and nitrogen atmospheres.(Author) [pt

  16. Synthesis of lithium niobate and monocrystal growth by Czochralski method

    Balzuweit, K.

    1988-01-01

    The qualitative analysis of lithium niobate by x-ray analysis and optical microscopy is presented. The lithium niobate compound was obtained by synthesis using niobium oxides and lithium carbonates. The lithium niobate monocrystal growth was done by Czochralski method. (M.C.K.)

  17. Study of calcium carbonate and sulfate co-precipitation

    Zarga, Y.

    2013-06-01

    Co-precipitation of mineral based salts in scaling is still not well understood and/or thermodynamically well defined in the water industry. This study focuses on investigating calcium carbonate (CaCO3) and sulfate mixed precipitation in scaling which is commonly observed in industrial water treatment processes including seawater desalination either by thermal-based or membrane-based processes. Co-precipitation kinetics were studied carefully by monitoring several parameters simultaneously measured, including: pH, calcium and alkalinity concentrations as well as quartz microbalance responses. The CaCO3 germination in mixed precipitation was found to be different than that of simple precipitation. Indeed, the co-precipitation of CaCO3 germination time was not anymore related to supersaturation as in a simple homogenous precipitation, but was significantly reduced when the gypsum crystals appeared first. On the other hand, the calcium sulfate crystals appear to reduce the energetic barrier of CaCO3 nucleation and lead to its precipitation by activating heterogeneous germination. However, the presence of CaCO3 crystals does not seem to have any significant effect on gypsum precipitation. IR spectroscopy and the Scanning Electronic Microscopy (SEM) were used to identify the nature of scales structures. Gypsum was found to be the dominant precipitate while calcite and especially vaterite were found at lower proportions. These analyses showed also that gypsum crystals promote calcite crystallization to the detriment of other forms. © 2013 Elsevier Ltd.

  18. Physico-chemical studies for strontium sulfate radiation dosimeter

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  19. Study of Phytoremediation Capability in Sulfate Removal from Water

    Milad Tafazoli

    2014-07-01

    Full Text Available Phytoremediation is known as a pollutants method with low cost, without operational complexity, with low energy consumption and no need for sludge disposal. In this study, hydroponic cultivation was chosen for estimation of sulfate removal as a significant sulfur compound in effluents on two fenny plants: pampas grass and bamboo.In this case, the plants were examined under two different retention times and after determining the optimum time (7 days, the main experiments were done for evaluating the plants removal efficiency and sulfate mass absorbance by plants. For better analysis, T-Test and ANOVA with significant influence (p < 0.05% were also done. Finally, the removal efficiency in pampas grass for all concentrations of 50, 200, 300, 600, 900, 1200, 1500 and 3000 mg/L were 44, 36, 34.22, 30.55, 15.93, 9.72, 7.77 and 4.44 percent, respectively, which were up to two times higher for the bamboos.

  20. X-ray diffraction study of lithium hydrazinium sulfate and lithium ammonium sulfate crystals under a static electric field

    Sebastian, M.T.; Becker, R.A.; Klapper, H.

    1991-01-01

    X-ray diffraction studies are made on proton-conducting polar lithium hydrazinium sulfate and ferroelectric lithium ammonium sulfate. The X-ray rocking curves recorded with in situ electric field along the polar b axis of lithium hydrazinium sulfate (direction of proton conductivity) show a strong enhancement of the 0k0 diffraction intensity. The corresponding 0k0 X-ray topographs reveal extinction contrast consisting of striations parallel to the polar axis. They disappear when the electric field is switched off. The effect is very strong in 0k0 but invisible in h0l reflections. It is present only if the electric field is parallel to the polar axis b. This unusual X-ray topographic contrast is correlated with the proton conduction. It is supposed that, under electric field, an inhomogeneous charge distribution develops, distorting the crystal lattice. Similar experiments on lithium ammonium sulfate also show contrast variations, but of quite different behaviour than before. In this case they result from changes of the ferroelectric domain configuration under electric field. (orig.)

  1. Relativistic electron planar channeling and diffraction in thin monocrystals

    Vorob'ev, S.A.; Nurmagambetov, S.B.; Kaplin, V.V.; Rozum, E.I.

    1985-01-01

    The interaction of relativistic electrons with thin monocrystals was investigated in approximation of continuous potential of crystal plane system. Numerical technique for solution of one-dimensional Schroedinger equation with a periodic potential was developed. Numerical solutions conducted according to the technique were used to determine the forms of ngular distributions of electrons located in various zones of lteral motion. Calculation results were applied for analyzing experimentally obtained data on agular distribution of 5.1 MeV electrons projected at small angles onto the (110) planar system of a Si monocrystal. The conducted complex experimental and theoretical: investigations demonstrated the possibility of prevalen occupation of certain states of lateral motion and enabled to determine angular reg in directions of the electron beam projection on a crystal where either channeling effects or those of electron diffraction are important

  2. Orientational anharmonicity of interatomic interaction in cubic monocrystals

    Belomestnykh, Vladimir N.; Tesleva, Elena P.

    2010-01-01

    Anharmonicity of interatomic interaction from a position of physical acoustics under the standard conditions is investigated. It is shown that the measure of anharmonicity of interatomic interaction (Grilneisen parameter) is explicitly expressed through velocities of sound. Calculation results of orientation anharmonicity are shown on the example of 116 cubic monocrystals with different lattice structural type and type of chemical bond. Two types of anharmonicity interatomic interaction anisotropy are determined. Keywords: acoustics, orientational anharmonicity, Gruneisen parameter, velocity of sound

  3. Acidity enhancement of niobia by sulfation: An experimental and DFT study

    Rocha, Angela S., E-mail: angela.sanches.rocha@gmail.com [Universidade do Estado do Rio de Janeiro, Departamento de Físico-Química, Instituto de Química, Rio de Janeiro (Brazil); Costa, Gustavo C. [Universidade do Estado do Rio de Janeiro, Departamento de Físico-Química, Instituto de Química, Rio de Janeiro (Brazil); Tamiasso-Martinhon, Priscila; Sousa, Célia; Rocha, Alexandre B. [Universidade Federal do Rio de Janeiro, Departamento de Físico-Química, Instituto de Química, Rio de Janeiro (Brazil)

    2017-01-15

    Acidic solids are used as catalyst at several industrial processes and studies to improve their activities have been developed by different groups. One method well known is sulfating oxide to create new acid sites, but investigations about sulfated niobia are still scarce. This work studied the influence of sulfation on the niobia acidity by using a very simple reaction model, the esterification of acetic acid with ethanol, performed at 60 °C and 1 atm. Niobia and sulfated niobia samples were characterized by N{sub 2} adsorption, X-ray diffraction, FTIR and titration with n-butylamine. To investigate the nature of sulfate groups formed on the surface of niobia, calculations based on the Density Functional Theory (DFT) have been performed for two models: pure niobia with hydroxylated surface and sulfated niobia where one OH{sup −} surface group was replaced by a HSO{sub 4}{sup −}. The experimental results indicated that the sulfation treatment leads to an increase in the specific surface area, acidity and, consequently, in the activity of niobia, with small changes in the crystal structure of the solid. The presence of sulfate groups was evidenced by FTIR spectra and calculations have indicated HSO{sub 4}{sup −} species bounded to the surface. Density Functional Perturbation Theory (DFPT) was also employed to obtain infrared intensities in the region of sulfate vibration bands. - Highlights: • Sulfation treatment has improved the acidity of niobium oxide. • A sulfate group on niobia (T-Nb{sub 2}O{sub 5}) was proposed using DFT method. • Niobia and sulfated niobia are used for esterification of acetic acid with ethanol.

  4. Acidity enhancement of niobia by sulfation: An experimental and DFT study

    Rocha, Angela S.; Costa, Gustavo C.; Tamiasso-Martinhon, Priscila; Sousa, Célia; Rocha, Alexandre B.

    2017-01-01

    Acidic solids are used as catalyst at several industrial processes and studies to improve their activities have been developed by different groups. One method well known is sulfating oxide to create new acid sites, but investigations about sulfated niobia are still scarce. This work studied the influence of sulfation on the niobia acidity by using a very simple reaction model, the esterification of acetic acid with ethanol, performed at 60 °C and 1 atm. Niobia and sulfated niobia samples were characterized by N 2 adsorption, X-ray diffraction, FTIR and titration with n-butylamine. To investigate the nature of sulfate groups formed on the surface of niobia, calculations based on the Density Functional Theory (DFT) have been performed for two models: pure niobia with hydroxylated surface and sulfated niobia where one OH − surface group was replaced by a HSO 4 − . The experimental results indicated that the sulfation treatment leads to an increase in the specific surface area, acidity and, consequently, in the activity of niobia, with small changes in the crystal structure of the solid. The presence of sulfate groups was evidenced by FTIR spectra and calculations have indicated HSO 4 − species bounded to the surface. Density Functional Perturbation Theory (DFPT) was also employed to obtain infrared intensities in the region of sulfate vibration bands. - Highlights: • Sulfation treatment has improved the acidity of niobium oxide. • A sulfate group on niobia (T-Nb 2 O 5 ) was proposed using DFT method. • Niobia and sulfated niobia are used for esterification of acetic acid with ethanol.

  5. X-ray investigation of fatigued nickel monocrystals by an analysis of diffraction line profiles

    Schmidt, G.K.

    1988-01-01

    Using a statistics of the inhomogeneous plastic deformation of a fatigued FCC monocrystal it may be possible to analyse the intensity distributions of the X-ray reflections of this crystal with regard to the fatigue phenomena. The results of an X-ray investigation of a fatigued nickel monocrystal are desribed. 3 refs.; 1 figure; 1 table

  6. Stringed converters on a basis of Ge1-xSix monocrystals

    Abbasov, Sh.M.; Abbasov, Sh. I.; Baytsar, R.I

    2003-01-01

    Full Text: The representing electromechanical resonator on elastic vibrations of monocrystal strings from semiconductor materials rather simple in manufacturing of stringed tenzoconverter on the basis of Ge-Si monocrystals was described. The examples os such class of converters using in concrete designs of devices for measurement of various physical parameters were reported

  7. Development of an accelerated test for Internal Sulfate Attack study

    Khelil Nacim

    2014-04-01

    Full Text Available Internal Sulfate Attack (ISA is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts. This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation techniques such as electrochemical chloride extraction (ECE in order to accelerate the leaching of alkalis that could be one of the triggers of the pathology. The study presented in this paper focused on concrete specimens prepared from cement (CEM I 52.5 N enriched with Na2SO4. These concretes have undergone a heat treatment typical of those used in precast plants (up to 24 hours with a maximum temperature of 80 °C. Various paths were explored for the development of the accelerated test. The first results showed that it was necessary to use a removable titanium anode ruthenium anode instead of stainless steel embedded in the concrete. Then tests with de-ionized water as the solute to the cathode did not accelerate the onset of expansions. The experiment has been modified and potassium carbonate was added to the solution. This modification didn’t show any significant improvement, and other experiments are being carried out to explain this result.

  8. Anti-tumor Study of Chondroitin Sulfate-Methotrexate Nanogels

    Wang, Jinyu; Zhao, Weibo; Chen, Haixiao; Qin, An; Zhu, Peizhi

    2017-10-01

    Self-assembly nanogels (NGs) were formed by bioconjugating methotrexate (MTX) with chondroitin sulfate (CS). MTX-CS NGs can greatly enhance the solubility and improve the delivery efficacy of MTX due to the CD44 binding property of CS. Vivo experiments revealed that MTX-CS NGs showed less toxicity than MTX. MTX-CS NGs can improve the anti-tumor effect while reducing the side effects of MTX. Due to their CD44 binding property, chondroitin sulfate-drug conjugates could be a promising and efficient platform for improving the solubility of sparingly soluble drug molecules as well as targeted delivery to cancer cells and tumor tissues.

  9. Synthesis, structural and physico-chemical studies of the monocrystal superconductor oxides Hg Ba{sub 2} Ca{sub n-1} Cu{sub n} O{sub 2n+2+{delta}}; Synthese, etudes structurales et physico-chimiques de monocristaux d`oxydes supraconducteurs Hg Ba{sub 2} Ca{sub n-1} Cu{sub n} O{sub 2n+2+{delta}}

    Viallet-Guillen, Virginie [Dept. de Recherche sur l` Etat Condense, CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-01-01

    The thesis presents the synthesis and the structural and physico-chemical properties of the mercury-based monocrystal superconductor oxides. The results reported in the first chapter refer to the first three members of the mercury cuprate series Hg-1201, Hg-1212 and Hg-1223. In the second chapter detailed results concerning the structure of these compounds are given highlighting the features common to all cuprates and pointing out the peculiarities of mercury phases. The third chapter presents the phase diagrams ({delta}, T, p(O{sub 2})) of the compounds HgBa{sub 2}CuO{sub 4+{delta}} and HgBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+{delta}} obtained by thermogravimetry under controlled atmosphere between 150 deg.C and 500 deg.C and thermodynamic equilibrium conditions. In the case of Hg-1201, the critical temperature shows a variation close to a parabolic law, with an optimal Tc of 96 K ({delta}{approx_equal}0.10) while in Hg-1223 the Tc increases linearly with the O content up to the optimal Tc of 135 K ({delta}{approx_equal}0.19) and decreases only by 2 K in the over-doped regime. Finally, in the fourth chapter different physical properties are reviewed. The obtained monocrystals allowed studying the resistive transitory anisotropy, the torque, the specific heat, the nuclear magnetic resonance and the Raman diffusion 212 refs., 106 figs., 30 tabs.

  10. Studies on Thermal Decomposition of Aluminium Sulfate to Produce Alumina Nano Structure

    M. Jafar-Tafreshi

    2012-12-01

    Full Text Available Aluminum sulfate nano structures have been prepared by solution combustion synthesis using aluminum nitrate nonahydrate (Al(NO33.9H2O and ammonium sulfate ((NH42SO4. The resultant aluminum sulfate nano structures were calcined at different temperatures to study thermal  decomposition of aluminum sulfate. The crystallinity and phase of  the as-synthesized and calcined samples were characterized by both X- ray diffraction and FTIR measurements. These two analyses determined the temperature at which the aluminum sulfate is converted to γ-alumina nano particles. The specific surface area and pore size distribution for  γ-alumina nano particles were determined by BET measurement. TEM measurement confirmed the size of the particles obtained by XRD and BET analyses.

  11. Growth mechanisms and morphology of NaCl monocrystals obtained by the Czochralski method

    Goujon, Gilles G.

    1969-01-01

    In its first part, this research thesis describes the various aspects of the theory of crystal growth in melt bath by drawing with growth being limited either by heat transfer phenomena or by mechanisms of molecule transport through the interface. The second part addresses the quality of the obtained monocrystals (dislocations, dislocation density) while discussing the impact of external growth parameters (germ choice and orientation, drawing speed, rotating speed, atmosphere, impurities, crystal diameter). Then, the author presents an experimental study (equipment, experimental conditions) and discusses its results (influence of temperature on crystal geometry, morphology of side surface, study of crystal plane faces by chemical attack). The next part proposes an interpretation of the morphology change of a crystal drawn by the Czochralski method

  12. Preparation of naphtalene monocrystals for scintillometers

    Gaeta, R.

    1959-01-01

    A method to prepare naphthalene crystals for scintillometers is described. The different methods of preparation and the reasons to choose the Bridgman method are analysed. The thermal curves of the growing furnaces, blister shape, use of curved capillaries and the most convenient growing velocities are studied in detail. Methods of preparation of high purity naphthalene by means of chromatography and zone melting are described. Finally the operations of cutting and polishing of crystal and their most significant physics properties are studied. (Author) 28 refs

  13. Effect of electronic radiation in Nb monocrystals

    Otero, M.P.; Lucki, G.

    1984-01-01

    The effect of the electronic irradiation in the Nb monocrystalline samples is studied. The irradiation source were the electrons from the high voltage electronic microscopy from the Argonne National Laboratory operating in 900 KeV. With the irradiation and deformation 'in-situ' experiments, dislocations in the samples were observed and the effect of the electrons in those dislocations during 59m of irradiation was studied. The follow applied deformation, show the differences in the displacements behavior of the non-irradiated and irradiated region. The growth rate of the displacements rings were determined. (E.G.) [pt

  14. Specific features of energy and spatial distribution of primary knocked-out atoms in monocrystals

    Taratin, A.M.; Vorob'ev, S.A.

    1978-01-01

    By simulation trajectories of 0.2 MeV protons in 1 μm thick Al monocrystal, the energy and spatial distributions of primary atoms knocked out by the protons (PKA) have been studied. Different orientations of the incident beam axis relative to the densely packed direction in the case of ''quasichanneling'' and ''chaotic'' scattering of particles by the crystal have been researched. The depth dependence of the number of generated PKA, their distribution in the plane transverse to the preferred direction, and the energy spectrum of PKA have been obtained. It is shown that the PKA volume density is higher than that obtained using evaluations not accounting for the crystalline structure, and the energy spectrum contains more low energy PKAs. A concept of the cross section of the PKA production on an atomic chain is introduced for ipterpretation of the data obtained

  15. Braked rotation of CH3 group in L-alanine monocrystals: temperature transformation of EPR spectrum

    Lemanov, V.V.; Sochava, L.S.

    2003-01-01

    EPR spectra temperature transformation of the irradiated alanine crystals is used for studying rotation of CH 3 methyl group in L-alamine monocrystals. 60 Co (2 x 10 4 Gy dose) was applied as a γ-radiation source. The simple method of experimental data processing which is reduced to obtaining the resonance lines width dependence on the temperature is used for the quantitative analysis of the spectrum temperature transformation. Temperature dependence of the CH 3 group rotation frequency is identified on the basis of these data. Activation energy U = 0.18 eV and pre-exponential multiplier ω 0 = 10 13 s -1 are determined from the EPR spectra temperature transformation which are in good agreement with values obtained earlier from the measurements of the proton spin-lattice relaxation in alanine polycrystal samples [ru

  16. Diffractometric measurement of the temperature dependence of piezoelectric tensor in GMO monocrystal

    Breczko, Teodor; Lempaszek, Andrzej

    2007-04-01

    Functional materials, of which an example is ferroelectric, ferroelastic monocrystal of molybdate (III) gadolinium (VI), are often used in the micro-motor operators (micro-servo motors) working in changeable environment conditions. Most frequently this change refers to temperature. That is why the important practical problem is the precise measurement of the value of piezoelectric tensor elements in dependence on the temperature of a particular monocrystal. In the presented article for this kind of measurements, the use of X-ray diffractometer has been shown. The advantage of the method presented is that, apart from precise dependence measurement between the temperature of a monocrystal and the value of piezoelectric tensor elements, it enables synchronous measurement of the value of thermal expansion tensor elements for a monocrystal.

  17. Superficial deformations determination in silicon monocrystals by X-ray difraction

    Carvalho, C.A.M.

    1985-01-01

    We present a technique of determination of deformation distribution in monocrystal surfaces through the adjustement of Bragg reflection patterns obtained from the X-ray diffraction theory. (M.W.O.) [pt

  18. An exploratory study of alkali sulfate aerosol formation during biomass combustion

    Løj, Lusi Hindiyarti; Frandsen, Flemming; Livbjerg, Hans

    2008-01-01

    mechanism. The modeling predictions are compared to data from laboratory experiments and entrained flow reactor experiments available in the literature. The analysis support that alkali sulfate aerosols are formed from homogeneous nucleation following a series of steps occurring in the gas phase. The rate......It is still in discussion to what extent alkali sulfate aerosols in biomass combustion are formed in the gas phase by a homogeneous mechanism or involve heterogeneous or catalyzed reactions. The present study investigates sulfate aerosol formation based on calculations with a detailed gas phase......-limiting step may be the oxidation of sulfite to sulfate, rather than the oxidation of SO2 to SO3 proposed previously. Even though the proposed model is consistent with experimental observations, experiments in a rigorously homogeneous system are called for to test its validity....

  19. Effect of oxygen content on vibrational and electron transitions in YBa2Cu3O6+x monocrystals

    Bazhenov, A.V.; Timofeev, V.B.

    1990-01-01

    Reflection spectra for light polarization are studied in YBa 2 Cu 3 O 6+x monocrystals. The main dipole-active vibrational modes are classified for tetragonal phase and using Kremers-Kronig correlation spectrum of dielectric function is reconstructed. The charge anisotropy for dielectric tetragonal phase, and also this phase ionicity are ascertained. The detected transitions are interpreted in frames of the known range calculations. It is stated that with average by volume oxygen separation into two stable phases, corresponding to X=0.6 and X=0.2, is seen

  20. Sulfate adsorption on goethite

    Rietra, R P.J.J.; Hiemstra, T; Riemsdijk, W.H. van

    1999-10-15

    Recent spectroscopic work has suggested that only one surface species of sulfate is dominant on hematite. Sulfate is therefore a very suitable anion to test and develop adsorption models for variable charge minerals. The authors have studied sulfate adsorption on goethite covering a large range of sulfate concentrations, surface coverages, pH values, and electrolyte concentrations. Four different techniques were used to cover the entire range of conditions. For characterization at low sulfate concentrations, below the detection limit of sulfate with ICP-AES, the authors used proton-sulfate titrations at constant pH. Adsorption isotherms were studied for the intermediate sulfate concentration range. Acid-base titrations in sodium sulfate and electromobility were used for high sulfate concentrations. All the data can be modeled with one adsorbed species if it is assumed that the charge of adsorbed sulfate is spatially distributed in the interface. The charge distribution of sulfate follows directly from modeling the proton-sulfate adsorption stoichoimemtry sine this stoichiometry is independent of the intrinsic affinity constant of sulfate. The charge distribution can be related to the structure of the surface complex by use of the Pauling bond valence concept and is in accordance with the microscopic structure found by spectroscopy. The intrinsic affinity constant follows from the other measurements. Modeling of the proton-ion stoichoimetry with the commonly used 2-pK models, where adsorbed ions are treated as point charges, is possible only if at least two surface species for sulfate are used.

  1. Investigation of Sulfate concentration influence on Anaerobic Lagoon performance: Birjand Wastewater Treatment plant: A Case study

    Mohammad Malakootian

    2016-05-01

    Full Text Available Background and Aim: In the present study the influence of the different sulfate concentration on the anaerobic lagoon stabilization was investigated. Materials and Methods: The present study is an experimental research carried out on anaerobic stabilization pond pilot for 7 months in Birjand wastewater treatment plant. After making sure of a steady state sulfate with different concentrations of 200, 300 and 400 mg/L were injected into the pilot. Then parameters including pH, organic nitrogen, ammonia nitrogen, BOD5, COD and nitrate were measured. All of the experiments were carried out according to the methods presented in the book "Standard Method" for the examination of water and wastewater (2005. Results: It was found that by increasing sulfate concentration from 200 to 300 mg/L all of parameters  except BOD5 (10% reduction had no significant changes., but by increasing the sulfate concentration from 200 to 400 mg/L the removal efficiency of the parameters such as BOD5, COD, Organic nitrogen, total kjeldahl nitrogen, nitrate and sulfate reduced to 11, 8, 12, 26, 6 and 10 percent, respectively. PH in the first stage was alkaline and then changed to acidic. Conclusion: Anaerobic stabilization ponds have different capacities for removal of organic compounds at different sulfate concentrations; so that; in sulfate concentration of 200 mg/L, the proper operation was seen and in concentration of 300 mg/L, sulfate-reducing bacteria get dominant and therefore odor is produced..  Alternatively, by increasing the concentration of sulphate to 400 mg/L, ammonia nitrogen increased 2.5 times (150% in the effluent.

  2. A Synchrotron Mössbauer Spectroscopy Study of a Hydrated Iron-Sulfate at High Pressures

    Perez, T. M.; Finkelstein, G. J.; Solomatova, N. V.; Jackson, J. M.

    2017-12-01

    Szomolnokite is a monohydrated ferrous iron sulfate mineral, FeSO4*H2O, where the ferrous iron atoms are in octahedral coordination with four corners shared with SO4 and two with H2O. While somewhat rare on Earth, szomolnokite has been detected on the surface of Mars along with several other hydrated sulfates and suggested to occur near the surface of Venus [1,2]. It is not clear if these sulfates are a result of reactions occurring at depth driven by changes in the behavior of iron in the sulfate. To date, only a few high-pressure studies have been conducted on hydrated iron sulfates using Mössbauer spectroscopy. Our study represents a first step towards understanding of the electronic environment of iron in a monohydrated sulfate at pressure. Using a hydrostatic helium pressure-transmitting medium, the pressure dependence of iron's site-specific behavior in a synthetic szomolnokite powdered sample was explored up to about 100 GPa with time-resolved synchrotron Mössbauer spectroscopy at the Advanced Photon Source of Argonne National Laboratory. At 1 bar, the Mössbauer spectrum is well described by three Fe2+-like sites, consistent with conventional Mössbauer spectra reported in Dyar et al. [3]. At pressures up to 20 GPa, changes in the hyperfine parameters are most likely due to a structural phase transition. Above this pressure, a fourth site is required to explain the time-spectra. Changes in the electronic configuration of iron, such as those due to a phase transition and/or a spin crossover, will affect the material's compressibility and transport properties. We will compare our high-pressure trends with those of other iron-bearing phases and discuss the relative influence on the dynamics of terrestrial planetary interiors. 1. Bishop et al. (2014) What Lurks in the Martian Rocks and Soil? Investigations of Sulfates, Phosphates, and Perchlorates. Spectral and thermal properties of perchlorate salts and implications for Mars. Am. Min. 99(8-9), 1580

  3. Hydrothermal Growth of Quasi-Monocrystal ZnO Thin Films and Their Application in Ultraviolet Photodetectors

    Yung-Chun Tu

    2015-01-01

    Full Text Available Quasi-monocrystal ZnO film grown using the hydrothermal growth method is used for the fabrication of Cu2O/ZnO heterojunction (HJ ultraviolet photodetectors (UV-PDs. The HJ was formed via the sputtering deposition of p-type Cu2O onto hydrothermally grown ZnO film (HTG-ZnO-film. The effect of annealing temperature in the nitrogen ambient on the photoluminescence spectra of the synthesized ZnO film was studied. The optoelectronic properties of Cu2O/ZnO film with various Cu2O thicknesses (250–750 nm under UV light (365 nm; intensity: 3 mW/cm2 were determined. The UV sensitivity of the HTG-ZnO-film-based UV-PDs and the sputtered ZnO-film-based UV-PDs were 55.6-fold (SHTG and 8.8-fold (Ssputter, respectively. The significant gain in sensitivity (SHTG/Ssputter = 630% of the proposed ZnO-film-based device compared to that for the device based on sputtered film can be attributed to the improved photoelectric properties of quasi-monocrystal ZnO film.

  4. Microstructural and Microanalytical Study on Concrete Exposed to the Sulfate Environment

    Qing, Fang; Beixing, Li; Jiangang, Yin; Xiaolu, Yuan

    2017-11-01

    Microstructural properties have been examined to investigate the effect of mineral admixtures on the sulfate resistance of concrete. Concrete and cement paste specimens made with ordinary Portland cement (OPC) or ordinary Portland cement incorporating 20% fly ash (FA) or 30% ground blast furnace slag (GBFS), were made and exposed to 250 cycles of the cyclic sulfate environment. Microstructural and Microanalytical study was conducted by means of x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that the pore structure of concrete after sulfate exposure possesses the fractal feature. The OPC concrete presents more complex pore internal surface, higher porosity and less micro-pores than the concrete incorporating fly ash and GBFS. Portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum; while for OPC-GBFS concrete, both gypsum and ettringite are formed. In the cyclic sulfate environment, repeated hydration and dehydration of sulfates produce the expansive stress in pores, aggravating the demolishment of concrete structure.

  5. Comparison of Bupivacaine Plus Magnesium Sulfate and Ropivacaine Plus Magnesium Sulfate Infiltration for Postoperative Analgesia in Patients Undergoing Lumbar Laminectomy: A Randomized Double-blinded Study.

    Hazarika, Rajib; Parua, Samit; Choudhury, Dipika; Barooah, Rajesh Kumar

    2017-01-01

    The objective of this study was to assess and compare the analgesic duration of local infiltration of bupivacaine plus magnesium sulfate and ropivacaine plus magnesium sulfate for postoperative analgesia in patients undergoing lumbar laminectomy. A randomized, prospective, double-blinded single hospital, comparative study. Sixty adult patients of the American Society of Anesthesiologists physical Status I and II were randomly allocated into two Groups BM and RM, comprising 30 and 31 patients. Postlumbar laminectomy, the study drug was locally infiltrated into the paravertebral muscles on either side before skin closure. Group BM was given 20 ml of 0.25% bupivacaine combined with 500 mg of magnesium sulfate (constituted with normal saline [NS]), and Group RM was given 20 ml of 0.25% ropivacaine combined with 500 mg of magnesium sulfate (constituted with NS). Postoperative visual analog scale pain score was assessed hourly for the first 24 h postoperatively. Duration of postoperative analgesia, rescue analgesia consumption and side effects were also recorded. Comparison of data between the groups was done with SPSS 21.0© using independent t -test, Chi-square test, and Mann-Whitney U-test accordingly. P <0.05 was considered statistically significant. Time to first analgesic consumption was significantly longer in Group BM (7.3 ± 0.46 h) compared to Group RM (6.6 ± 0.69 h) ( P < 0.05). The consumption of nalbuphine rescue analgesic was significantly higher in Group RM (15.33 ± 5.07 mg) compared to Group BM (12 ± 4.07 mg) ( P < 0.05). Wound infiltration with bupivacaine and magnesium sulfate compared to ropivacaine and magnesium sulfate provided longer duration of postoperative analgesia and significantly reduced postoperative opioid consumption in patients undergoing lumbar laminectomy.

  6. Comparative study on the mechanisms of rotavirus inactivation by sodium dodecyl sulfate and ethylenediaminetetraacetate

    Ward, R.L. (Sandia Labs., Albuquerque, NM); Ashley, C.S.

    1980-06-01

    This report describes a comparative study on the effects of the anionic detergent sodium dodecyl sulfate and the chelating agent ethylenediaminetetraacetate on purified rotavirus SA-11 particles. Both chemicals readily inactivated rotavirus at quite low concentrations and under very mild conditions. In addition, both agents modified the viral capsid and prevented the adsorption of inactivated virions to cells. Capsid damage by ethylenediaminetetraacetate caused a shift in the densities of rotavirions from about l.35 to about 1.37 g/ml and a reduction in their sedimentation coefficients. Sodium dodcyl sulfate, on the other hand, did not detectably alter either of these physical properties of rotavirions. Both agents caused some alteration of the isoelectric points of the virions. Finally, analysis of rotavirus proteins showed that ethylenediaminetetraacetate caused the loss of two protein peaks from the electrophoretic pattern of virions but sodium dodecyl sulfate caused the loss of only one of these same protein peaks.

  7. Understanding the performance of sulfate reducing bacteria based packed bed reactor by growth kinetics study and microbial profiling.

    Dev, Subhabrata; Roy, Shantonu; Bhattacharya, Jayanta

    2016-07-15

    A novel marine waste extract (MWE) as alternative nitrogen source was explored for the growth of sulfate reducing bacteria (SRB). Variation of sulfate and nitrogen (MWE) showed that SRB growth follows an uncompetitive inhibition model. The maximum specific growth rates (μmax) of 0.085 and 0.124 h(-1) and inhibition constants (Ki) of 56 and 4.6 g/L were observed under optimized sulfate and MWE concentrations, respectively. The kinetic data shows that MWE improves the microbial growth by 27%. The packed bed bioreactor (PBR) under optimized sulfate and MWE regime showed sulfate removal efficiency of 62-66% and metals removal efficiency of 66-75% on using mine wastewater. The microbial community analysis using DGGE showed dominance of SRB (87-89%). The study indicated the optimum dosing of sulfate and cheap organic nitrogen to promote the growth of SRB over other bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Impact of elevated nitrate on sulfate-reducing bacteria: A comparative study of Desulfovibrio vulgaris

    He, Q.; He, Z.; Joyner, D.C.; Joachimiak, M.; Price, M.N.; Yang, Z.K.; Yen, H.-C. B.; Hemme, C. L.; Chen, W.; Fields, M.; Stahl, D. A.; Keasling, J. D.; Keller, M.; Arkin, A. P.; Hazen, T. C.; Wall, J. D.; Zhou, J.

    2010-07-15

    Sulfate-reducing bacteria have been extensively studied for their potential in heavy-metal bioremediation. However, the occurrence of elevated nitrate in contaminated environments has been shown to inhibit sulfate reduction activity. Although the inhibition has been suggested to result from the competition with nitrate-reducing bacteria, the possibility of direct inhibition of sulfate reducers by elevated nitrate needs to be explored. Using Desulfovibrio vulgaris as a model sulfate-reducing bacterium, functional genomics analysis reveals that osmotic stress contributed to growth inhibition by nitrate as shown by the upregulation of the glycine/betaine transporter genes and the relief of nitrate inhibition by osmoprotectants. The observation that significant growth inhibition was effected by 70 mM NaNO{sub 3} but not by 70 mM NaCl suggests the presence of inhibitory mechanisms in addition to osmotic stress. The differential expression of genes characteristic of nitrite stress responses, such as the hybrid cluster protein gene, under nitrate stress condition further indicates that nitrate stress response by D. vulgaris was linked to components of both osmotic and nitrite stress responses. The involvement of the oxidative stress response pathway, however, might be the result of a more general stress response. Given the low similarities between the response profiles to nitrate and other stresses, less-defined stress response pathways could also be important in nitrate stress, which might involve the shift in energy metabolism. The involvement of nitrite stress response upon exposure to nitrate may provide detoxification mechanisms for nitrite, which is inhibitory to sulfate-reducing bacteria, produced by microbial nitrate reduction as a metabolic intermediate and may enhance the survival of sulfate-reducing bacteria in environments with elevated nitrate level.

  9. Studies on the pore water sulfate, chloride and sedimentary methane to understand the sulfate reduction process in the eastern Arabian Sea

    Karisiddaiah, S.M.; Borole, D.V.; Rao, B.R.; Paropkari, A.L.; Joao, H; Kocherla, M.; Sarkar, G.P.; Biswas, G.; Kumar, N.

    Sediment cores (~5 m length) from ten stations collected in the water depths of 2665-3210 m in the eastern Arabian Sea were studied for pore water sulfate (SO42-), chloride (Cl-) and lighter-hydrocarbons (methane: C1, ethane:C2 and propane: C3...

  10. A dedicated torsion balance to detect neutrinos by coherent scattering on high Debye temperature monocrystals

    Cruceru, I; Nicolescu, G [National Institute of Research and Development for Physics and Nuclear Engineering ' Horia - Hulubei' , PO Box MG - 6, 077125 Magurele (Romania); Duliu, O G [University of Bucharest, Department of Atomic and Nuclear Physics, PO Box MG-II, 077125 Magurele (Romania)

    2008-11-01

    Coherent scattering of neutrinos on high Debye temperature monocrystals represent an alternative to detect solar as well as other high flux neutrino sources such as nuclear reactors or nuclear tests. Therefore, the possibility of detecting neutrinos by using sapphire monocrystals is presented and analyzed. Preliminary evaluations showed that 1 MeV neutrinos with a fluency density of 10{sup 12} cm{sup -1} s{sup -1} could interact with a 100 g sapphire monocrystal with a force of about 10{sup -6} dyne, value measurable with a high sensitivity torsion balance. For this reason a torsion balance provided with 1 m length molybdenum or tungsten wire and an optical autocollimator able to measure small rotation angles of about 0.1 seconds of arc was designed, constructed and now is under preliminary tests. Both theoretical and practical implications of such kind of detector are presented and discussed.

  11. SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

    Fox, K.; Edwards, T.

    2012-05-08

    This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to develop a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude

  12. Transmission of germanium poly- and monocrystals for thermal neutrons at different temperatures

    Adib, M.; Abdel-Kawy, A.; Eid, Y.; Maayouf, R.M.; Abbas, Y.; Habib, N.; Kilany, M.; Ashry, A.

    1987-01-01

    Neutron cross-sections of germanium poly- and monocrystals were measured with two time-of-flight and two double-axis crystal spectrometers. The results were analyzed using the single-level Breit-Wigner formula. The coherent scattering amplitude was determined from the Bragg reflections observed in the cross-section of a polycrystal and the analysis of the neutron diffraction pattern. The incoherent and the thermal diffuse scattering cross-section were estimated from the analysis of the total cross-section data obtained for a monocrystal at different temperatures in the energy range 2 meV to 1 eV. (orig./HP) [de

  13. Transmission of germanium poly- and monocrystals for thermal neutrons at different temperatures

    Adib, M.; Abdel-Kawy, A.; Eid, Y.; Maayouf, R.M.; Abbas, Y.; Habib, N.; Kilany, M.; Ashry, A.

    Neutron cross-sections of germanium poly- and monocrystals were measured with two time-of-flight and two double-axis crystal spectrometers. The results were analyzed using the single-level Breit-Wigner formula. The coherent scattering amplitude was determined from the Bragg reflections observed in the cross-section of a polycrystal and the analysis of the neutron diffraction pattern. The incoherent and the thermal diffuse scattering cross-section were estimated from the analysis of the total cross-section data obtained for a monocrystal at different temperatures in the energy range 2 meV to 1 eV.

  14. Evidence for oral agmatine sulfate safety--a 95-day high dosage pilot study with rats.

    Gilad, Gad M; Gilad, Varda H

    2013-12-01

    Agmatine, decarboxylated arginine, exerts beneficial effects in various experimental disease models. Clinical trials indicate the safety and effectiveness of short-term (up to 21 days) high dose regimens of oral agmatine sulfate, but longer term studies are lacking. This pilot study undertook to assess the safety of a longer term high dosage oral agmatine sulfate in laboratory rats. Adult Wistar rats consumed 5.3 g/l agmatine sulfate in their drinking water for 95 days, a regimen estimated to result in a daily dosage of absorbed agmatine of about 100mg/kg. Animals' body weight, water consumption and blood pressure were periodically measured, and general cage behavior, fur appearance, urination and feces appearance monitored. These parameters were also determined at 20 days after treatment cessation (day 115). On days 95 and 115, animals were euthanized for gross necropsy assessment. Agmatine-treated rats showed slight, but significant reductions in body weight and blood pressure, and reduced water consumption during treatment, which recovered completely within 20 days after treatment cessation. Otherwise, no abnormal behaviors or organ pathologies were observed. These findings are first to suggest apparent safety of sub-chronic high dosage dietary agmatine sulfate in laboratory rats, thus lending further support to the therapeutic applications of agmatine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. A case-referent study of cancer mortality among sulfate mill workers in Sweden.

    Andersson, E; Hagberg, S; Nilsson, T; Persson, B; Wingren, G; Torén, K

    2001-05-01

    To investigate whether workers in Swedish sulfate mills have an increased risk of death from certain malignancies that have previously been linked to the pulping process. Subjects of the study (n=2480) were men aged 40-75 at death during 1960-89 in the parishes surrounding four sulfate mills. Exposure assessment was based on information from the personnel files in the mills- 35% of the subjects were recognised there, and work categories were created. Among all sulfate mill workers, the odds ratio (OR) (90% confidence interval (90% CI)) for death from lung cancer was 1.6 (1.1 to 2.3), pleural mesotheliomas 9.5 (1.9 to 48), brain tumours 2.6 (1.2 to 5.3), and liver or biliary tract cancer 2.3 (1.0 to 5.2). There was an increased mortality from leukaemia among workers in the soda recovery plant (5.9 (2.6 to 13)) and bleaching plant and digester house (2.8 (1.0 to 7.5)). Sulfate mill workers were at increased risk of dying from lung cancer and pleural mesotheliomas, probably due to exposure to asbestos. Increased risks of brain tumours and cancers of the liver or biliary tract were also found but the aetiology is not obvious.

  16. Comparison of adsorption equilibrium models and error functions for the study of sulfate removal by calcium hydroxyapatite microfibrillated cellulose composite.

    Hokkanen, Sanna; Bhatnagar, Amit; Koistinen, Ari; Kangas, Teija; Lassi, Ulla; Sillanpää, Mika

    2018-04-01

    In the present study, the adsorption of sulfates of sodium sulfate (Na 2 SO 4 ) and sodium lauryl sulfate (SLS) by calcium hydroxyapatite-modified microfibrillated cellulose was studied in the aqueous solution. The adsorbent was characterized using elemental analysis, Fourier transform infrared, scanning electron microscope and elemental analysis in order to gain the information on its structure and physico-chemical properties. The adsorption studies were conducted in batch mode. The effects of solution pH, contact time, the initial concentration of sulfate and the effect of competing anions were studied on the performance of synthesized adsorbent for sulfate removal. Adsorption kinetics indicated very fast adsorption rate for sulfate of both sources (Na 2 SO 4 and SLS) and the adsorption process was well described by the pseudo-second-order kinetic model. Experimental maximum adsorption capacities were found to be 34.53 mg g -1 for sulfates of SLS and 7.35 mg g -1 for sulfates of Na 2 SO 4. The equilibrium data were described by the Langmuir, Sips, Freundlich, Toth and Redlich-Peterson isotherm models using five different error functions.

  17. Microscope and X-ray investigations of the implanted silicium monocrystals

    Auleytner, J.; Drwiega, M.; Furmanik, Z.; Godwod, K.; Krylow, J.; Lazarski, S.; Maciaszek, M.; Maydel-Ondrusz, E.

    1974-01-01

    The evaluation of the usefullness of bi-crystallic spectrometer and topographic method is presented to investigate the changes in implantated silicium monocrystals and diffraction effects as caused by implantation. The samples have been also examined by electronic microscope JEM-1000. (author)

  18. Production and characterization of monocrystals of the cubic Laves phases Se-Al2

    Beyss, M.; Uelhoff, W.; Fattah, A.

    1977-04-01

    The monocrystals of the cubic Laves phases Se-Al 2 have been produced for special measurements. Low-temperature anomalies were measured which were influenced by doping with foreign atoms. These anomalies, also called Kondo effect, were detected in some physical quantities like electric resistance, magnetic resistance, susceptibility, magnetization, specific heat, thermal conductivity and thermoelectric force. For diffuse magnetic neutron scattering, monocrystals with the dimensions 10 mm diameter and 70 mm length were produced. The materials used were La Al 2 , (La Ce) Al 2 , Ce Al 2 , Y Al 2 , and (Y Ce) Al 2 . The monocrystals had to have an exactly cylindrical cross-section which was obtained by stripping by means of spark erosion machines. The measurements were carried out at the reactor of the Laue-Langevin Institute at Grenoble. In the experiments the magnetic behavior was measured by neutron scattering on monocrystals in the temperature range from 2.5 K to 300 K, the energy spectra having been registered. (orig.) [de

  19. Calculation of radiation loss of 1. 2 GeV-electrons in a thick silicon monocrystal

    Keshtova, S.V.; Komarov, F.F.; Telegin, V.I.

    1988-10-01

    The angular distribution of radiation loss of different fractions of 1.2 GeV-electrons during axial channeling in a Si monocrystal of 1.6 mm thickness is discussed. The results of the numerical calculations are compared with the experimental data.

  20. Oral carcinogenicity study with nickel sulfate hexahydrate in Fischer 344 rats

    Heim, Katherine E.; Bates, Hudson K.; Rush, Rusty E.; Oller, Adriana R.

    2007-01-01

    Until now, existing data on the oral carcinogenicity of nickel substances have been inconclusive. Yet, the assessment of oral carcinogenicity of nickel has serious scientific and regulatory implications. In the present study, nickel sulfate hexahydrate was administered daily to Fischer 344 rats by oral gavage for 2 years (104 weeks) at exposure levels of 10, 30 and 50 mg NiSO 4 ·6H 2 O/kg. This treatment produced a statistically significant reduction in body weight of male and female rats, compared to controls, in an exposure-related fashion at 30 and 50 mg/kg/day. An exposure-dependent increase in mortality was observed in female rats. However, the overall study survival rate (males and females) was at least 25 animals per group (compliant with OECD guidelines) in the treated animals. Daily oral administration of nickel sulfate hexahydrate did not produce an exposure-related increase in any common tumor type or an increase in any rare tumors. One tumor type was statistically increased in a nickel sulfate-treated group compared to the study controls (keratoacanthoma in the 10 mg NiSO 4 ·6H 2 O/kg/day males), but there was no exposure-response relationship for this common tumor type. This study achieved sufficient toxicity to reach the Maximum Tolerated Dose (MTD) while maintaining a sufficiently high survival rate to allow evaluation for carcinogenicity. The present study indicated that nickel sulfate hexahydrate does not have the potential to cause carcinogenicity by the oral route of exposure in the Fischer 344 rat. Data from this and other studies demonstrate that inhalation is the only route of exposure that might cause concern for cancer in association with nickel exposures

  1. Isotope studies to determine dry deposition of sulfate to deciduous and coniferous trees: Final draft

    Garten, C.T. Jr.

    1988-01-01

    Experiments have been conducted at two locations near Oak Ridge, Tennessee, with radioactive 35 S (87 day half-life) to examine the cycling behavior of sulfur in yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and loblolly pine (Pinus taeda) trees. Some findings pertain to methods development for estimating dry deposition of sulfur to forest canopies and the magnitude of sulfur emissions from natural sources (Task II). We will determine through field studies, the internal cycling, storage, and biogenic emission of sulfur, as traced by 35 SO 4 2- , in environments impacted by atmospheric sulfate deposition; and will determine through isotope dilution studies, the contribution of foliar leaching and dry deposition to net throughfall (NTF) sulfate concentrations beneath deciduous and coniferous trees in such environments. 3 refs., 2 figs., 1 tab

  2. Dyeing Studies with Eucalyptus, Quercetin, Rutin, and Tannin: A Research on Effect of Ferrous Sulfate Mordant

    Rattanaphol Mongkholrattanasit; Charoon Klaichoi; Nattadon Rungruangkitkrai; Nattaya Punrattanasin; Kamolkan Sriharuksa; Monthon Nakpathom

    2013-01-01

    Natural dyes from Eucalyptus leaf extract, quercetin, rutin, and tannin were applied to silk fabric by pad-batch and pad-dry techniques under different conditions. Ferrous sulfate was used as a mordant. The dyeing properties were evaluated by measuring K/S and CIELAB values. In addition, the different fastness properties were evaluated. The effect of dyes at different concentration levels with respect to their colour strength was also studied.

  3. Study on the behavior of sulfur in hydrolysis process of titanyl sulfate solution

    Zeng, Fanbo; Luo, Dongmei, E-mail: dmluo@scu.edu.cn; Zhang, Zhao; Liang, Bin; Yuan, Xizhi; Fu, Li

    2016-06-15

    The existing forms of sulfur in hydrolysis process of titanyl sulfate solution were studied. Also the effects of sulfur on crystal structure, crystallite size and crystal phase transition of the hydrated titanium dioxide(TiO{sub 2}·H{sub 2}O) and titanium dioxide (TiO{sub 2}) were conducted. The analysis and methods of thermogravimetric-differential scanning calorimet (TG-DSC), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra and Raman spectroscopy were employed to characterize. The results indicated that the sulfur was present in the form of SO{sub 4}{sup 2−} ions in the hydrolysate of titanyl sulfate solution, and a portion of SO{sub 4}{sup 2−} ions were combined on the surface of hydrated titanium dioxide by chemical adsorption in the forms of inorganic chelating bidentate coordination and covalent sulfate coordination, the residual SO{sub 4}{sup 2−} ions were adsorbed on the surface of hydrated titanium dioxide by physical adsorption. The chemical adsorption of SO{sub 4}{sup 2−} ions were conducive to the formation and stabilization of anatase, which changed the crystal structure, and hindered the transformation of the anatase into rutile. The results of Raman spectroscopy showed that the sulfur was dissociated in the forms of SO{sub 4}{sup 2−} and HSO{sub 4}{sup −} ions during the hydrolysis of titanyl sulfate solution. The characteristic peak at 1004 cm{sup −1} corresponding to a new complex has been observed, which was composed of SO{sub 4}{sup 2−} and hydrated titanium complex ions through the bonding on the surface. In basis of the above experimental results, the hydrolysis process of titanyl sulfate solution was illustrated from the microstructure with 3D atlas. - Highlights: • The SO{sub 4}{sup 2−} ions exist in TiO{sub 2}·H{sub 2}O by chemical and physical adsorption. • The SO{sub 4}{sup 2−} ions are conducive to the formation and

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

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

    2015-06-01

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

  5. Time-of-flight neutron diffractometer for monocrystal study

    Anan'ev, B.N.; Balagurov, A.M.; Barabash, I.P.; Georgiu, Z.; Shibaev, V.D.

    1979-01-01

    The design of a neutron diffractometer is discussed. It is used for structural analysis of single crystals on the basis of time-of-flight measurements. The diffractometer is positioned along the axis of a beam of the IBR-30 pulse reactor, its average power is 29 kW. The mechanical part of the diffractometer consists of a massive foundation with a threeaxial goniometer, a rotatable platform with a collimator and a 3 He counter. The flowsheet of a control unit is given, which is used to position the rotatable platform of the diffractometer. The control unit includes a 14 digic binary counter for rotation angle recording, a parallel-to-series converter, a control signal shaper, two position shift registers, and a servo mechanism. The accuracy of diffraction maxima is evaluated. It is found that the ratio D(t)sup(1/2)/t (D(t) is a time dispersion of diffraction maxima, t is total time-of-flight time), which characterize the resolution of the diffractometer, is equal to 0.5% at the Bragg angle Q=45 deg and the neutron wavelength Λ=1 A

  6. Analysis of the kinetics of the fragile fracture process in Mo monocrystals in quasi-relaxation

    Tamayo Meza, Pedro; Bautista Godinez, Eric Gustavo; Yermishkin, Viacheslav

    2008-01-01

    The method of quasi-relaxation, generally known as the force relaxation method, has been widely applied in the study of elementary dislocational processes. It is essential for the study and analysis of thermoactivated mechanisms, for the determination of the energy of interaction between dislocations and inclusions, in the definition of the dislocational constants, to predict the development of creep, and even for the study of fracture kinetics. For the first time the use of the quasi-relaxation method for evaluating the fragile fracture tendency was presented in the work. However, as usually carried out, the use of mass specimens and the development of a considerable plastic deformation in the vertex of the crack-notch sample limits the possibilities for this method. Many studies analyze the theoretical aspects of the fracture process, and the obtention of reliable quantitative information about the behavior of the dislocation based on an analytical description of the process, and how and when it influences the conditions under which the final catastrophic fracture occurs. This work proposes a new method to analyze the effect of a tension concentrator on the surface of Mo monocrystal specimens. The relaxation of the force and the increase in the crack opening is related to the development of the plastic zone in its vertex with the help of the Irwin correction. During the relaxation, the crack-groove grows until it attains the length of the plastic zone. Specimens with and without force concentrators were tested in quasi-relaxation. The cracks appearing under these conditions are analyzed using a scanning electron microscopy (SEM). The crack appearing in the specimens under load conditions, whose development produced heavy force relaxation, allowed the force relaxation value to be defined and compared in the specimens with and without tension concentrators (au)

  7. Rare earth sulfates

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  8. Process for obtaining oxygen doped zinc telluride monocrystals and scintillator crystals obtained by this process

    Schneider, Maurice; Moreau, Roland; D'Haenen, J.-P.; Merenda, Pierre.

    1976-01-01

    A process is described for obtaining oxygen doped zinc telluride monocrystals, for use as scintillator crystals for ionising radiation detectors. The following operations are carried out in succession: one or several zinc telluride crystals are introduced into a silica ampoule together with a ternary mixture of zinc tellurium and oxygen, as an oxide or hydroxide of these elements; the ampoule is pumped down to a high vacuum and sealed; the sealed ampoule containing the mixture and monocrystals is placed in a kiln and brought to a uniform temperature sufficient to make the mixture three-phased, depending on its composition; the zinc telluride crystalline compound remains solid; the ampoule is then tempered to bring it quickly back to ambient temperature [fr

  9. Strength of Dislocation Junctions in FCC-monocrystals with a [\\overline{1}11] Deformation Axis

    Kurinnaya, R. I.; Zgolich, M. V.; Starenchenko, V. A.

    2017-07-01

    The paper examines all dislocation reactions implemented in FCC-monocrystals with axis deformation oriented in the [\\overline{1}11] direction. It identifies the fracture stresses of dislocation junctions depending on intersection geometry of the reacting dislocation loop segments. Estimates are produced for the full spectrum of reacting forest dislocations. The paper presents the statistical data of the research performed and identifies the share of long strong dislocation junctions capable of limiting the zone of dislocation shift.

  10. Reflection of the energy structure of a tungsten monocrystal nearsurface area in the secondary electron spectrum

    Artamonov, O.M.; Smirnov, O.M.; Terekhov, A.N.

    1982-01-01

    Formation of secondary electron energy spectrum during emission from the crystal layer near the surface has been considered, at that layer energy structure can be different from volumetric energy structure. Its thickness depends on the predominant mechanism of electron scattering and is determined by corresponding phenomenological parameters. It is shown that the structure in the secondary electron spectrum appears in the case when energy structure of emitting monocrystal layer can not be described in the approximation of almost free electron gas and, as experimental investigations show, approaches energy zone structure of its volume. It is also show that in the case when the energy structure of the emitting layer is satisfactorily described with the model of almost free electron gas, the SE spectrum is characterized with traditional cascade minimum. Experimental investigation of SE energy distribution was carried out for the W monocrystalline face (110). It was established that distinct structure in the SE spectrum appears only after electrochemical polishing of the specimen surface. It is related to the appearance of ''far'' order in the monocrystal emission layer on initially disturbed tungsten surface during such treatment. Disturbance of tungsten monocrystal surface structure on its oxidation in O 2 atmosphere results in the appearance of the cascade maximum and disappearance of distinct peculiarities in the SE spectrum

  11. Effects of oversulfated and fucosylated chondroitin sulfates on coagulation. Challenges for the study of anticoagulant polysaccharides.

    Fonseca, Roberto J C; Oliveira, Stephan-Nicollas M C G; Pomin, Vitor H; Mecawi, André S; Araujo, Iracema G; Mourão, Paulo A S

    2010-05-01

    We report the effects of a chemically oversulfated chondroitin sulfate and a naturally fucosylated chondroitin sulfate on the coagulation system. The former has been recently identified as a contaminant of heparin preparations and the latter has been proposed as an alternative anticoagulant. The mechanism of action of these polymers on coagulation is complex and target different components of the coagulation system. They have serpin-independent anticoagulant activity, which preponderates in plasma. They also have serpin-dependent anticoagulant activity but differ significantly in the target coagulation protease and preferential serpin. Their anticoagulant effects differ even more markedly when tested as inhibitors of coagulation proteases using plasma as a source of serpins. It is possible that the difference is due to the high availability of fucosylated chondroitin sulfate whereas oversulfated chondroitin sulfate has strong unspecific binding to plasma protein and low availability for the binding to serpins. When tested using a venous thrombosis experimental model, oversulfated chondroitin sulfate is less potent as an antithrombotic agent than fucosylated chondroitin sulfate. These highly sulfated chondroitin sulfates activate factor XII in in vitro assays, based on kallikrein release. However, only fucosylated chondroitin sulfate induces hypotension when intravenously injected into rats. In conclusion, the complexity of the regulatory mechanisms involved in the action of highly sulfated polysaccharides in coagulation requires their analysis by a combination of in vitro and in vivo assays. Our results are relevant due to the urgent need for new anticoagulant drugs or alternative sources of heparin.

  12. Chondroitin sulfate-derivatized agarose beads: a new system for studying cation binding to glycosaminoglycans

    Hunter, G.K.

    1987-01-01

    Chondroitin sulfate (CS) has been covalently attached to aminoethyl-agarose beads in a carbodiimide-catalyzed reaction. In this process, an amide bond is formed between carboxylate groups on the glycosaminoglycan (GAG) and the primary amine groups of the beads. Under optimal conditions, up to 160 micrograms of CS is attached per milligram of beads. CS-agarose beads have been used to study Ca binding to GAGs. The beads are mixed with a solution containing CaCl 2 and 45 Ca and allowed to sediment under unit gravity. An aliquot of supernatant is then removed and 45 Ca activity is determined to quantitate remaining (free) Ca. Using this system, it was shown that CS binds approximately 0.7 Ca/disaccharide unit at saturation. Under the conditions used, the apparent association constant (KA) is approximately 14 mM. In principle, this derivatization protocol may be used to attach any proteoglycan or GAG (except keratan sulfate) to an insoluble support. CS-agarose beads provide a rapid, simple, and relatively artifact-free system for studying cation-GAG interactions

  13. Heparan sulfate biosynthesis

    Multhaupt, Hinke A B; Couchman, John R

    2012-01-01

    Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

  14. Contribution to the study of the reduction of sulfate by the yolk sac of the chicken embryo

    Bourgeois, Claude

    1958-11-01

    This academic reports addresses additional information obtained about the reduction of sulfate into sulphite by the yolk sac of a chicken embryo. Two important difficulties have been faced: the impossibility to isolate this reduction from reactions which immediately use the formed sulphite, and the impossibility to obtain an acellular preparation able to reduce the sulfate. Then, the problem of reduction of sulfate into sulphite by the yolk sac is associated with the problem of permeability of yolk sac cells to the studied substances. Thus, the author studied whether other animal species could provide a better material than the chicken embryo for this study of sulfate reduction. It appears that some vertebrate embryos present some evidence of sulphur metabolism similar to that of chicken embryo. However, this last one revealed to be the most favourable for the study. The author reports the study of the evolution of the reduction activity of the yolk sac sulfate with respect to the embryo age, and the effect of some metabolic inhibitors on this activity [fr

  15. Use of specific features of electron and positron interactions with monocrystals for the control of high-energy particle beam parameters

    Bochek, G.L.; Vit'ko, V.I.; Grishaev, I.A.; Kovalenko, G.D.; Kulibaba, V.I.; Morokhovskij, V.L.; Shramenko, B.I.

    1977-01-01

    To study possibilities of using the effect of high energy positron and electron interactions with crystals in practice at the 2 GeV Kharkov lineac the effect of a light particle charge sign on the processes of bremsstrahlung, elastic scattering and revealing ''blocking effect'' in elastic scatterina has been investigated experimentally of 1 GeV electron (positron) beam is directed to a silicon crystal of 185 μkm thickness. Dependence of total bremsstrahlung flow on the angle between the beam direction and crystal axis has shown, that positron bremsstrahlung is minimum (positrons are channelling, but electron bremsstrahlung is maximum, when crystallographic axis direction coincides with particle direction. The process of positron annihilation in flight has been investigated in 300 μkm thick silicon monocrystal. Bremsstrahlung intensity for channeling positrons drops 4.4 times, and intensity of annihilation radiation - 1.6 times as compared to the case, when channeling regime is absent. Experimental data point out the possibility of using monocrystals for control of the parameters of high-energy particle control beams

  16. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

    Clausen, S K; Sobhani, S; Poulsen, O M

    2000-01-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfact......The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice...

  17. A monocrystal of 59Co as a nuclear orientation thermometer in neutron experiments with oriented targets

    Fasoli, U.; Galeazzi, G.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.

    1980-01-01

    An apparatus for measuring temperatures in the millikelvin region is described based on the 'deformation effect' on fast neutron transmission through an aligned 59 Co monocrystal, employing a 252 Cf pill as the neutron source. A statistical accuracy of a few percent in a few minutes is obtainable with a heat input of some tens of pW. The apparatus is suitable in neutron experiments with oriented targets when the gamma-ray background hinders the use of gamma-ray anisotropy thermometers. In these and similar cases, in which the temperature must be held constant for long periods, the large heat capacity of the cobalt sample is not a drawback. (orig.)

  18. Safety assessment of non-animal chondroitin sulfate sodium: Subchronic study in rats, genotoxicity tests and human bioavailability.

    Miraglia, Niccolò; Bianchi, Davide; Trentin, Antonella; Volpi, Nicola; Soni, Madhu G

    2016-07-01

    Chondroitin sulfate, an amino sugar polymer made of glucuronic acid and N-acetyl-galactosamine, is used in dietary supplements to promote joint health. Commonly used chondroitin sulfate is of animal origin and can pose potential safety problems including bovine spongiform encephalopathy (BSE). The objective of the present study was to investigate potential adverse effects, if any, of microbial derived chondroitin sulfate sodium (CSS) in subchronic toxicity, genotoxicity and bioavailability studies. In the toxicity study, Sprague Dawley rats (10/sex/group) were gavaged with CSS at dose levels of 0, 250, 500 and 1000 mg/kg body weight (bw)/day for 90-days. No mortality or significant changes in clinical signs, body weights, body weight gain or feed consumption were noted. Similarly, no toxicologically relevant treatment-related changes in hematological, clinical chemistry, urinalysis and organ weights were noted. Macroscopic and microscopic examinations did not reveal treatment-related abnormalities. In vitro mutagenic and clastogenic potentials as evaluated by Ames assay, chromosomal aberration test and micronucleus assay did not reveal genotoxicity of CSS. In pharmacokinetic study in human, CSS showed higher absorption as compared to chondroitin sulfate of animal origin. The results of subchronic toxicity study supports the no-observed-adverse-effect level (NOAEL) for CSS as 1000 mg/kg bw/day, the highest dose tested. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Methodology for the study of the dolomite porosity in essay of interrupted sulfation

    Ávila, Ivonete; Crnkovic, Paula M.; Milioli, Fernando E.

    2010-01-01

    The aim of this work is to propose a methodology to evaluate the evolution of the pore blockage of limestone during the sulfation reaction. The experiments were performed for a national limestone (dolomite) with average particle size of 545 μm in interrupted sulfation tests were conducted at seven different times and at three different temperatures of the process. The empirical data were obtained from porosimetry tests to establish BET surface area, volume and average size of pore and di...

  20. Effectiveness of intra-articular injections of sodium hyaluronate-chondroitin sulfate in knee osteoarthritis: a multicenter prospective study.

    Rivera, Fabrizio; Bertignone, Luca; Grandi, Giancarlo; Camisassa, Roberto; Comaschi, Guido; Trentini, Diego; Zanone, Marco; Teppex, Giuseppe; Vasario, Gabriele; Fortina, Giorgio

    2016-03-01

    Intra-articular injection of hyaluronic acid is a well-established therapy for the treatment of knee osteoarthritis. The aim of the study was to assess the effectiveness and safety of the use of Arthrum HCS(®) (40 mg hyaluronic acid and 40 mg chondroitin sulfate in 2 mL). This was an open, multicenter, prospective study. Men or women over 40 years of age with documented knee osteoarthritis and WOMAC subscore A (severity of pain) ≥25 were enrolled. They received three weekly intra-articular injections of sodium hyaluronate 2 % and chondroitin sulfate 2 % in combination. WOMAC subscore A was assessed at 1, 3 and 6 months after the last injection. One hundred and twelve patients were included (women, 66 %). The mean (SD) WOMAC subscore A decreased from 52.1 (15.2) at inclusion to 20.5 (19.7) at month 6 (P chondroitin sulfate in reducing pain (77 %), improving mobility (78 %) and reducing the consumption of analgesics (74 %). Only one adverse effect was reported by one patient (knee tumefaction). These results suggest that intra-articular injections of Arthrum HCS(®) (sodium hyaluronate plus chondroitin sulfate) in patients with knee osteoarthritis are efficient and safe. These results should be confirmed in a randomized controlled study. IV.

  1. A comparative study of three cytotoxicity test methods for nanomaterials using sodium lauryl sulfate.

    Kwon, Jae-Sung; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-10-01

    The biocompatibility evaluation of nanomaterials is essential for their medical diagnostic and therapeutic usage, where a cytotoxicity test is the simplest form of biocompatibility evaluation. Three methods have been commonly used in previous studies for the cytotoxicity testing of nanomaterials: trypan blue exclusion, colorimetric assay using water soluble tetrazolium (WST), and imaging under a microscope following calcein AM/ethidium homodimer-1 staining. However, there has yet to be a study to compare each method. Therefore, in this study three methods were compared using the standard reference material of sodium lauryl sulfate (SLS). Each method of the cytotoxicity test was carried out using mouse fibroblasts of L-929 exposed to different concentrations of SLS. Compared to the gold standard trypan blue exclusion test, both colorimetric assay using water soluble tetrazolium (WST) and imaging under microscope with calcein AM/ethidium homodimer-1 staining showed results that were not statistically different. Also, each method exhibited various advantages and disadvantages, which included the need of equipment, time taken for the experiment, and provision of additional information such as cell morphology. Therefore, this study concludes that all three methods of cytotoxicity testing may be valid, though careful consideration will be needed when selecting tests with regard to time, finances, and the amount of information required by the researcher(s).

  2. Sub-THz spectroscopic characterization of vibrational modes in artificially designed DNA monocrystal

    Sizov, Igor; Rahman, Masudur; Gelmont, Boris; Norton, Michael L.; Globus, Tatiana

    2013-01-01

    Highlights: • Sub-THz spectroscopy is used to characterize artificially designed DNA monocrystal. • Results are obtained using a novel near field, RT, frequency domain spectrometer. • Narrow resonances of 0.1 cm −1 width in absorption spectra of crystal are observed. • Signature measured between 310 and 490 GHz is reproducible and well resolved. • Absorption pattern is explained in part by simulation results from dsDNA fragment. - Abstract: Sub-terahertz (sub-THz) vibrational spectroscopy is a new spectroscopic branch for characterizing biological macromolecules. In this work, highly resolved sub-THz resonance spectroscopy is used for characterizing engineered molecular structures, an artificially designed DNA monocrystal, built from a short DNA sequence. Using a recently developed frequency domain spectroscopic instrument operating at room temperature with high spectral and spatial resolution, we demonstrated very intense and specific spectral lines from a DNA crystal in general agreement with a computational molecular dynamics (MD) simulation of a short double stranded DNA fragment. The spectroscopic signature measured in the frequency range between 310 and 490 GHz is rich in well resolved and reproducible spectral features thus demonstrating the capability of THz resonance spectroscopy to be used for characterizing custom macromolecules and structures designed and implemented via nanotechnology for a wide variety of application domains. Analysis of MD simulation indicates that intense and narrow vibrational modes with atomic movements perpendicular (transverse) and parallel (longitudinal) to the long DNA axis coexist in dsDNA, with much higher contribution from longitudinal vibrations

  3. The MOAHLFA index of irritant sodium lauryl sulfate reactions: first results of a multicentre study on routine sodium lauryl sulfate patch testing.

    Uter, Wolfgang; Geier, Johannes; Becker, Detlef; Brasch, Jochen; Löffler, Harald

    2004-01-01

    In a multicentre study of the German Contact Dermatitis Research Group, sodium lauryl sulfate (SLS) 0.25% and 0.5% aq. has been added to routine allergen patch tests to assess its properties as a convenient diagnostic indicator of individual susceptibility to irritation at the time of patch testing. Previous studies indicated that irritant SLS reactivity may be related to individual factors such as age and sex. As these factors are, in turn, among the important predictors of contact allergy to many allergens, e.g. summarized in the 'MOAHLFA index', the impact of the MOAHLFA factors on irritant SLS patch test reactivity, and thus a potential for confounding, was assessed in the 5971 participating patients. As a result of 2 logistic regression analyses with an irritant reaction to 0.25% and 0.5% SLS, respectively, as outcome, male sex was identified as a relatively weak but significant risk factor (OR 1.38), while age 40 years or older was an even weaker risk factor (OR 1.22 and 1.15, respectively). Upon detailed analysis, no clear age gradient could, however, be identified. 1-day exposure time almost halved the odds of an irritant SLS reaction. In conclusion, this type of SLS patch test can be regarded as robust, indicating individual irritability relatively independent from the individual factors analysed here.

  4. Direct Sulfation of Limestone

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  5. Barium Sulfate

    ... uses a computer to put together x-ray images to create cross-sectional or three dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque contrast media. It works by coating the esophagus, stomach, or ...

  6. Matrix-isolation FT-IR spectra and theoretical study of dimethyl sulfate

    Borba, Ana; Gómez-Zavaglia, Andrea; Simões, Pedro N. N. L.; Fausto, Rui

    2005-05-01

    The preferred conformations of dimethyl sulfate and their vibrational spectra were studied by matrix-isolation FT-IR spectroscopy and theoretical methods (DFT and MP2, with basis sets of different sizes, including the quadruple-zeta, aug-cc-pVQZ basis). Conformer GG (of C 2 symmetry and exhibiting O sbnd S sbnd O sbnd C dihedral angles of 74.3°) was found to be the most stable conformer in both the gaseous phase and isolated in argon. Upon annealing of the matrix, the less stable observed conformer (GT; with C 1 symmetry) quickly converts to the GG conformer, with the resulting species being embedded in a matrix-cage which corresponds to the most stable matrix-site for GG form. The highest energy TT conformer, which was assumed to be the most stable conformer in previous studies, is predicted by the calculations to have a relative energy of ca. 10 kJ mol -1 and was not observed in the spectra of the matrix-isolated compound.

  7. Effect of continuous magnesium sulfate infusion on spinal block characteristics: A prospective study

    Akansha Agrawal

    2014-01-01

    Full Text Available Background: Spinal anesthesia is an established mode of anesthesia for lower limb orthopedic surgeries. The limitations of the technique are short duration of action and limited post-operative analgesia. Concomitant use of intravenous infusion of magnesium sulfate may have an effect on the block characteristics and duration of action of intrathecal bupivacaine. Methods: A total of 80 American Society of Anesthesiologists I and II patients, either sex, 20-60 years of age scheduled for elective orthopedic fixation of fracture of long bones of lower limbs under spinal anesthesia were included. Spinal anesthesia administered with 2.5 ml heavy bupivacaine mixed with 10 mcg fentanyl. The groups were then divided to receive an infusion of injection magnesium sulfate 50 mg/kg/h over 15 min followed by 15 mg/kg/h until the end of the surgery (Group M and 15 ml of Normal Saline over 15 min followed by 100 ml/h until the end of surgery (Group S. Onset, duration of sensory and motor block and amount of post-operative analgesic were noted. Results: A total of 6 patients (Group M and seven patients (Group S had inadequate block and excluded from the study. Mean block height was T6. Time required to achieve block height was 8.82 min versus 7.42 min in Groups M and S respectively (P = 0.04. Mean duration of motor block was longer in group M (160.63 ± 17.76 min compared with Group S (130.12 ± 20.70 min (P = 0.000. Time for regression of sensory block to T12/L1was 206.88 ± 20.96 min (Group M and 163.88 ± 15.46 min (Group S (P = 0.000. Hemodynamic parameters were similar and statistically not significant. Need for first analgesic requirement was after 262.88 ± 21.11 min in group M and 193.25 ± 17.74 min in the group S (P = 0.000. Mean dosage of tramadol needed in first 24 h was less in group M (190 ± 30.38 mg vs. 265 ± 48.30 mg, P = 0.000. Conclusion: Use of intravenous magnesium with spinal anesthesia reduces post-operative pain and analgesic consumption.

  8. A XPS Study of the Passivity of Stainless Steels Influenced by Sulfate-Reducing Bacteria.

    Chen, Guocun

    The influence of sulfate-reducing bacteria (SRB) on the passivity of type 304 and 317L stainless steels (SS) was investigated by x-ray photoelectron spectroscopy (XPS), microbiological and electrochemical techniques. Samples were exposed to SRB, and then the resultant surfaces were analyzed by XPS, and the corrosion resistance by potentiodynamic polarization in deaerated 0.1 M HCl. To further understand their passivity, the SRB-exposed samples were analyzed by XPS after potentiostatic polarization at a passive potential in the hydrochloric solution. The characterization was performed under two surface conditions: unrinsed and rinsed by deaerated alcohol and deionized water. Comparisons were made with control samples immersed in uninoculated medium. SRB caused a severe loss of the passivity of 304 SS through sulfide formation and possible additional activation to form hexavalent chromium. The sulfides included FeS, FeS_2, Cr_2S _3, NiS and possibly Fe_ {rm 1-x}S. The interaction took place nonuniformly, resulting in undercutting of the passive film and preferential hydration of inner surface layers. The bacterial activation of the Cr^{6+ }^ecies was magnified by subsequent potentiostatic polarization. In contrast, 317L SS exhibited a limited passivity. The sulfides were formed mainly in the outer layers. Although Cr^{6+}^ecies were observed after the exposure, they were dissolved upon polarization. Since 317L SS has a higher Mo content, its higher passivity was ascribed to Mo existing as molybdate on the surface and Mo^{5+} species in the biofilm. Consequently, the interaction of SRB with Mo was studied. It was observed that molybdate could be retained on the surfaces of Mo coupons by corrosion products. In the presence of SRB, however, a considerable portion of the molybdate interacted with intermediate sulfur -containing proteins, forming Mo(V)-S complexes and reducing bacterial growth and sulfate reduction. The limited insolubility of the Mo(V)-S complexes in 0

  9. Anisotropy in angular distributions of 238U fission fragments by photons, produced in high energy electron interaction with Si monocrystal

    Kasilov, V.I.; Lapin, N.N.

    1981-01-01

    An enhancement is detected under the angle of 90 deg in the fission fragment yield from 238 U nuclei produced by photons emitted by high-energy electrons passing through a silicon monocrystal. The results enable one to select the most optimal conditions to obtain maximal yields of nuclear particles [ru

  10. Calculation of radiation loss of 1.2 GeV-electrons in a thick silicon monocrystal

    Keshtova, S.V.; Komarov, F.F.

    1988-01-01

    The angular distribution of radiation loss of different fractions of 1.2 GeV-electrons during axial channeling in a Si monocrystal of 1.6 mm thickness is discussed. The results of the numerical calculations are compared with the experimental data. (author)

  11. A pharmacoproteomic study confirms the synergistic effect of chondroitin sulfate and glucosamine.

    Calamia, Valentina; Mateos, Jesús; Fernández-Puente, Patricia; Lourido, Lucía; Rocha, Beatriz; Fernández-Costa, Carolina; Montell, Eulalia; Vergés, Josep; Ruiz-Romero, Cristina; Blanco, Francisco J

    2014-06-10

    Osteoarthritis (OA) is the most common age-related rheumatic disease. Chondrocytes play a primary role in mediating cartilage destruction and extracellular matrix (ECM) breakdown, which are main features of the OA joint. Quantitative proteomics technologies are demonstrating a very interesting power for studying the molecular effects of some drugs currently used to treat OA patients, such as chondroitin sulfate (CS) and glucosamine (GlcN). In this work, we employed the iTRAQ (isobaric tags for relative and absolute quantitation) technique to assess the effect of CS and GlcN, both alone and in combination, in modifying cartilage ECM metabolism by the analysis of OA chondrocytes secretome. 186 different proteins secreted by the treated OA chondrocytes were identified. 36 of them presented statistically significant differences (p ≤ 0.05) between untreated and treated samples: 32 were increased and 4 decreased. The synergistic chondroprotective effect of CS and GlcN, firstly reported by our group at the intracellular level, is now demonstrated also at the extracellular level.

  12. Synthesis, characterization and in vitro study of magnetic biphasic calcium sulfate-bioactive glass

    Goh, Yi-Fan; Akram, Muhammad; Alshemary, Ammar Z. [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Darul Ta' zim (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta' zim (Malaysia)

    2015-08-01

    Calcium sulfate-bioactive glass (CSBG) composites doped with 5, 10 and 20 mol% Fe were synthesized using quick alkali sol–gel method. X-ray diffraction (XRD) data of samples heated at 700 °C revealed the presence of anhydrite, while field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) characterization confirmed the formation of nano-sized CSBGs. The UV–vis studies confirmed that the main iron species in 5% Fe and 10% Fe doped CSBGs were tetrahedral Fe(III) whereas that in 20% Fe doped CSBG were extra-framework FeO{sub x} oligomers or iron oxide phases. Measurement of magnetic properties of the samples by vibrating sample magnetometer (VSM) showed very narrow hysteresis loop with zero coercivity and remanence for 10% Fe and 20% Fe doped CSBG, indicating that they are superparamagnetic in nature. All samples induced the formation of apatite layer with Ca/P ratio close to the stoichiometric HA in simulated body fluid (SBF) assessment. - Highlights: • Biphasic calcium sulphate-bioactive glass containing iron was prepared. • Composite bioglass was superparamagnetic in nature. • All samples promoted the growth of apatite layer with Ca/P close to 1.67.

  13. Kinetic Study of Hydroxyl and Sulfate Radical-Mediated Oxidation of Pharmaceuticals in Wastewater Effluents.

    Lian, Lushi; Yao, Bo; Hou, Shaodong; Fang, Jingyun; Yan, Shuwen; Song, Weihua

    2017-03-07

    Advanced oxidation processes (AOPs), such as hydroxyl radical (HO • )- and sulfate radical (SO 4 •- )-mediated oxidation, are alternatives for the attenuation of pharmaceuticals and personal care products (PPCPs) in wastewater effluents. However, the kinetics of these reactions needs to be investigated. In this study, kinetic models for 15 PPCPs were built to predict the degradation of PPCPs in both HO • - and SO 4 •- -mediated oxidation. In the UV/H 2 O 2 process, a simplified kinetic model involving only steady state concentrations of HO • and its biomolecular reaction rate constants is suitable for predicting the removal of PPCPs, indicating the dominant role of HO • in the removal of PPCPs. In the UV/K 2 S 2 O 8 process, the calculated steady state concentrations of CO 3 •- and bromine radicals (Br • , Br 2 •- and BrCl •- ) were 600-fold and 1-2 orders of magnitude higher than the concentrations of SO 4 •- , respectively. The kinetic model, involving both SO 4 •- and CO 3 •- as reactive species, was more accurate for predicting the removal of the 9 PPCPs, except for salbutamol and nitroimidazoles. The steric and ionic effects of organic matter toward SO 4 •- could lead to overestimations of the removal efficiencies of the SO 4 •- -mediated oxidation of nitroimidazoles in wastewater effluents.

  14. SFG and SPR Study of Sodium Dodecyl Sulfate Film Assembly on Positively Charged Surfaces

    Song, Sanghun; Weidner, Tobias; Wagner, Matthew; Castner, David

    2012-02-01

    This study uses sum frequency generation (SFG) vibrational spectroscopy and surface plasmon resonance (SPR) sensing to investigate the structure of sodium dodecyl sulfate (SDS) films formed on positively charged and hydrophilic surfaces. The SPR signals show a good surface coverage suggesting that full monolayer coverage is reached at 1 mM. SFG spectra of SDS adsorbed exhibits well resolved CH3 peaks and OH peaks. At both 0.2 mM and 1 mM SDS concentration the intensity of both the CH3 and OH peaks decreased close to background levels. We found that the loss of SFG signal at 0.2 mM occurs at this concentration independent of surface charge density. It is more likely that the loss of signal is related to structural inhomogeneity induced by a striped phase - stand-up phase transition. This is supported by a distinct change of the relative SFG phase between CH3/OH near 0.2 mM. The second intensity minimum might be related to charge compensation effects. We observed a substrate dependence for the high concentration transition. We also observed distinct SFG signal phase changes for water molecules associated with SDS layers at different SDS solution concentrations indicating that the orientation of bound water changed with SDS surface structure.

  15. Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis

    Angeliki Marietou

    2018-03-01

    Full Text Available The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.

  16. Study on the pelletizing of sulfate residue with magnetite concentrate in grate-kiln system

    Shufeng Y.

    2010-01-01

    Full Text Available The experiment on the feasibility of pelletizing with magnetite concentrate and the wasted sulfate residue was carried out, to research the performance of pellet in grate-kiln system and simulate the grate-kiln pelletizing process in the micro-pellet roasting simulation system in laboratory, and the process experiments on preheating and roasting sections were conducted. The results show that in order to obtain pellet with good performance and the magnetite concentrate should be over 20 in mass percent, the suitable pelletizing time is about 10 min and moisture is around 12.5%. Also, according to the process parameters of drying and preheating sections obtained from experiment, it will be successful to use magnetite concentrate and the wasted sulfate residue for pelletizing, which exploits a new way for the use of sulfate residue.

  17. Preliminary study of ethanol electrooxidation in the presence of sulfate on polycrystalline platinum

    Ferreira, R.S. Jr.; Oliveira, V.R.; Reis, R.G.C.S.; Maia, G.; Camara, G.A. [Departamento de Quimica/UFMS, C.P. 549, 79070-900, Campo Grande, MS (Brazil)

    2008-12-01

    The electrooxidation of ethanol and its inhibition by the presence of adsorbed sulfate have been investigated by cyclic voltammetry and chronoamperometry using several concentrations of sulfuric acid on smooth polycrystalline platinum. The results show that the concentration of sulfuric acid influences the current in both potentiostatic and potentiodynamic experiments. The results are interpreted in terms of the competitive adsorption of sulfate and ethanol on the same Pt sites and suggest that, when the sulfuric acid concentration is increased, there is a reduction of Pt free sites able to adsorb and oxidize ethanol. The voltammetric data reveal that the peak currents observed during ethanol oxidation are not affected in the same way by the presence of H{sub 2}SO{sub 4}, which, based on previously obtained FTIR results, suggests that the sulfate adsorption is able to inhibit the oxidation of ethanol in a selective way. (author)

  18. Mechanisms of deformation and of recrystallization of imperfect uranium monocrystals

    Calais, D.

    1960-04-01

    The various means by which plastic deformations by slip, twinning or kinking are produced by tension of imperfect α uranium single crystals prepared by a β → α phase change, have been studied by X-rays and micrographic examination. Depending on the crystallographic orientation with respect to the direction of the applied tension, and depending on the magnitude of the change in length, the crystals are deformed either preferentially according to a single mechanism, for example twinning, or simultaneously according to two or three mechanisms. The results of a subsequent annealing of the deformed single in the α phase are studied with respect to the deformation mechanisms. In the case of a deformation due primarily to (010) [100], (011) [100] or (110) [001] sliding, there occurs recrystallization by crystal growth selectivity. If the deformation occurs via deformation bands, there is recrystallization by 'oriented nucleation'. The crystals deformed preponderantly by twinning give on recrystallization perfect crystals having optimum dimensions and having orientational characteristics closely related to those of the original crystal. Finally are discussed some criteria relating to the geometry and the dynamics with a view to explaining the occurrence of such and such a deformation mechanism of a single crystal with a given orientation. This study, in conclusion, must help to define the best conditions (crystalline orientation and process of deformation) which will promote the growth of large, perfect, single crystals. (author) [fr

  19. Enhanced sulfate reduction with acidogenic sulfate-reducing bacteria

    Wang Aijie; Ren Nanqi; Wang Xu; Lee Duujong

    2008-01-01

    Sulfate reduction in a continuous flow, acidogenic reactor using molasses wastewater as the carbon source was studied at varying chemical oxygen demand/sulfate (COD/SO 4 2- ) ratios. At a critical COD/SO 4 2- ratio of 2.7, neither COD nor sulfate were in excess for extra production of ethanol or acetate in the reactor. An acetic-type microbial metabolism was established with sulfate-reducing bacteria (SRB) significantly consuming hydrogen and volatile fatty acids produced by acidogenic bacteria and hydrogen producing acetogens in degrading COD, thereby yielding sulfate removal rate >94.6%. A low critical COD/SO 4 2- ratio of 1.6 was also observed with the enriched ASRB population in reactor which overcomes the barrier to the treatment capability of sulfate-laden wastewater treatment with limited COD supply

  20. Interaction between sodium dodecyl sulfate and membrane reconstituted aquaporins: A comparative study of spinach SoPIP2;1 and E. coli AqpZ

    Hansen, Jesper Schmidt; Vararattanavech, Ardcharaporn; Plasencia, Inés

    2011-01-01

    This study describes the interaction between sodium dodecyl sulfate (SDS) and membrane proteins reconstituted into large unilamellar lipid vesicles and detergent micelles studied by circular dichroism (CD) and polarity sensitive probe labeling. Specifically, we carried out a comparative study of ...

  1. Computational study of the effect of glyoxal-sulfate clustering on the Henry's Law coefficient of glyoxal

    Kurtén, Theo; Elm, Jonas; Prisle, Nønne L.

    2015-01-01

    . Although the glyoxal molecule interacts only weakly with sulfate, its hydrated forms (C2O3H4 and C2O4H6) form strong complexes with sulfate, displacing water molecules from the solvation shell and increasing the uptake of glyoxal into sulfate-containing aqueous solutions, including sulfate...... coefficient enhancement and found it to be in reasonable agreement with experimental results. This indicates that the complexation of glyoxal hydrates with sulfate can explain the observed uptake enhancement....

  2. Conformational studies on five octasaccharides isolated from chondroitin sulfate using NMR spectroscopy and molecular modeling

    Blanchard, V.; Chevalier, F.; Imberty, A.; Leeflang, B.R.; Sugahara, K.; Kamerling, J.P.

    2007-01-01

    Chondroitin sulfate proteoglycans (CS-PG) are involved in the regulation of the central nervous system in vertebrates due to their presence on cell surfaces and in the extracellular matrix of tissues. The CS moieties are built up from repeating -4)GlcA(β 1-3)GalNAc(β 1- disaccharide units, partly

  3. Experimental and numerical study on cement paste degradation under external sulfate attack

    Ma, X.; Copuroglu, O.; Schlangen, H.E.J.G.; Han, N; Xing, F; Saouma, V.; Bolander, J.; Landis, E.

    2016-01-01

    External sulfate attack is one of the situations that may cause gradual but severe damage in cementitious materials, which may lead to cracking, increased permeability and strength loss. In this paper, thin-walled hollow cement paste cylinders with a wall thickness of 2.5mm were made considering the

  4. Aqueous two-phase (polyethylene glycol + sodium sulfate) system for caffeine extraction: Equilibrium diagrams and partitioning study

    Araujo Sampaio, Daniela de; Mafra, Luciana Igarashi; Yamamoto, Carlos Itsuo; Forville de Andrade, Eriel; Oberson de Souza, Michèle; Mafra, Marcos Rogério; Castilhos, Fernanda de

    2016-01-01

    Highlights: • Binodal curves of PEG (400, 4000 and 6000) + Na_2SO_4 ATPS were determined. • Tie-lines were experimentally determined for aqueous (PEG 400 + Na_2SO_4) system. • Influence of caffeine on LLE of aqueous (PEG 400 + Na_2SO_4) system was investigated. • Partitioning of caffeine in aqueous (PEG 400 + Na_2SO_4) system was investigated. • Caffeine partition showed to be dependent on temperature and TLL. - Abstract: Environmental friendly methods for liquid–liquid extraction have been taken into account due to critical conditions and ecotoxicological effects potentially produced by organic solvents applied in traditional methods. Liquid–liquid extraction using aqueous two phase systems (ATPSs) presents advantages when compared to traditional liquid–liquid extraction. (Polyethylene glycol (PEG) + sodium sulfate + water) ATPS was applied to study partition of caffeine. Binodal curves for ATPSs composed of PEG of different molecular weights (400 g · mol"−"1, 4000 g · mol"−"1 and 6000 g · mol"−"1) sodium sulfate + water were determined by cloud point method at three different temperatures (293.15, 313.15 and 333.15) K. Liquid–liquid equilibrium (LLE) data (tie-lines, slope of the tie-line and tie-lines length) were obtained applying a gravimetric method proposed by Merchuck and co-workers at the same temperatures for aqueous (PEG 400 + sodium sulfate) and aqueous (PEG 400 + sodium sulfate + caffeine) systems. Reliability of the experimental tie-line (TL) data was evaluated using the equations reported by Othmer–Tobias and satisfactory linearity was obtained. Concerning to aqueous (PEG + sodium sulfate) system, the results pointed out that the higher PEG molecular weight the largest is the heterogeneous region. Moreover, temperature showed not to be relevant on binodal curves behavior, but it influenced on tie-line slopes. Partitioning of caffeine in aqueous (PEG 400 + sodium sulfate) system was investigated at different temperatures

  5. Kinetic study of the dehydration reaction of lithium sulfate monohydrate crystals using microscopy and modeling

    Lan, Shuiquan [Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612AZ Eindhoven (Netherlands); Zondag, Herbert [Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612AZ Eindhoven (Netherlands); Energy research Center of the Netherlands – ECN, P.O. Box 1, 1755ZG Petten (Netherlands); Steenhoven, Anton van [Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612AZ Eindhoven (Netherlands); Rindt, Camilo, E-mail: c.c.m.rindt@tue.nl [Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612AZ Eindhoven (Netherlands)

    2015-12-10

    Highlights: • Kinetics of Li{sub 2}SO{sub 4}·H{sub 2}O single crystals were modeled based on elementary processes. • Kinetics of nucleation and nuclei growth were studied by using optical microscopy. • A novel experiment was designed to visualize the reaction front into crystal bulk. • Fractional conversion was calculated and compared with TGA-experiments. - Abstract: Simulation of gas–solid reactions occurring in industrial processes requires a robust kinetic model to be applicable in a wide range of complicated reaction conditions. However, in literature it is often seen that even the same reaction under specific controlled conditions is interpreted with different kinetic models. In the present work, a phenomenological model based on nucleation and nuclei growth processes is presented to study the kinetics of the dehydration reaction of lithium sulfate monohydrate single crystals. The two elementary processes of the reaction, nucleation and nuclei growth, are characterized and quantified as a function of temperature by using optical microscopy experiments. The in-situ measured characteristics of the dehydration reaction provided confirmatory evidence that the rate of nucleation obeys an exponential law and the rate of nuclei growth is approximately constant. With knowledge acquired from the optical observations as inputs of the kinetic model, the fractional conversion of the dehydration reaction was calculated and compared with experimental results from thermogravimetric analysis (TGA). A satisfactory comparison was found both in isothermal and non-isothermal conditions. It is demonstrated that this knowledge-based model has a great potential to represent the gas–solid reaction kinetics in a wide range of process conditions regarding temperature, pressure and particle geometry.

  6. Structural studies on sulfated oligosaccharides derived from the carbohydrate-protein linkage region of chondroitin 6-sulfate proteoglycans of shark cartilage. (II.) Seven compounds containing 2 or 3 sulfate residues.

    Vliegenthart, J.F.G.; Waard, P. de; Harada, T.; Sugahara, K.

    1992-01-01

    Shark cartilage proteoglycans bear predominantly chondroitin 6-sulfate. After exhaustive protease digestion, reductive beta-elimination and subsequent chondroitinase ABC digestion, 13 hexasaccharide alditols were obtained from the carbohydrate-protein linkage region and six of them contain 0 or 1

  7. Study of radioactive sources accumulation with application of thermoluminescence dosemeters on the base of alkaline earth metals sulfates

    Tokbergenov, I.; Sadykov, T.

    2001-01-01

    Methodic for study of accumulation and distribution of radioactive sources in a nature objects is developed. An essence of the method consists of in that quantity of accumulated radioactive sources in a nature objects is defining by absorption dose measured with help of thermoluminescent dosemeters on the base of alkaline earth metals sulfates such as CaSO 4 :Dy and SrSO 4 :Eu

  8. Preparation of aromatic hydrocarbon monocrystals; Preparation de monocristaux d'hydrocarbures aromatiques

    Baret, C; Hering, H; Pichat, L; Thommeret, J

    1951-04-01

    This report explains the technique developed and used for the production of organic monocrystals, necessary for the detection of {gamma} radiation. The Bridgman process has been used. A glass bulb containing the substance to be crystallized passes through a vertical thermo-regulated furnace maintained slightly above the fusion point of the substance. The bottom of the bulb has a conical section which ends with a thin capillary in order to obtain a single crystal nucleus. This method has been implemented to several hydrocarbons (naphthalene, anthracene, stilbene, tolan, tetraphenylethylene, tetra-phenyl-butadiene). The report describes successively: the furnaces, the process used for the filling of the bulbs, the degassing of the products, and for each compound, the details of the preparation and purification and the size of the obtained crystals. (J.S.)

  9. Comparative study of attenuation of the pain caused by propofol intravenous injection, by granisetron, magnesium sulfate and nitroglycerine

    Dhananjay Kumar Singh

    2011-01-01

    Full Text Available Background: Propofol has the disadvantage of causing pain or discomfort on injection. The aim of the study was to assess the efficacy of pretreatment with various drugs to alleviate the propofol injection pain. Methods: One hundred American Society of Anesthesiology (ASA I and II adults, scheduled for various elective surgical procedures under general anesthesia (GA, were included in the study. They were randomly divided into four groups having 25 patients in each group. Group A received pretreatment with intravenous (i.v. magnesium sulfate, group B received i.v. granisetron, group C received i.v. nitroglycerine and group D was the control group. One-fourth of the total calculated induction dose of propofol was administered over a period of 5 seconds. The patients were asked about the pain on injection. The intensity of pain was assessed using verbal response. A score of 0-3 which corresponds to no, mild, moderate and severe pain was recorded. Results: All the three drugs reduced the incidence and intensity of pain on propofol injection but the order of efficacy in attenuation of pain on the propofol injection was granisetron > nitroglycerine > magnesium sulfate > control. Conclusion: Granisetron was the most effective followed by nitroglycerine and magnesium sulfate in attenuating pain on propofol intravenous injection.

  10. Density functional theory study on the ionic liquid pyridinium hydrogen sulfate

    Tankov, Ivaylo; Yankova, Rumyana; Genieva, Svetlana; Mitkova, Magdalena; Stratiev, Dicho

    2017-07-01

    The geometry, electronic structure and chemical reactivity of a pyridinium-based ionic liquid, pyridinium hydrogen sulfate ([H-Pyr]+[HSO4]-), have been discussed on the basis of quantum chemical density functional theory calculations using B3LYP/6-311+G(d,p) and B3LYP/6-311++G(2d,2p) approaches. The calculations indicated that [H-Pyr]+[HSO4]- exists in the form of an ion pair. A large electropositive potential was found on the pyridinium ring, while the regions of a negative electrostatic potential is linked with the lone pair of electronegative oxygen atoms in hydrogen sulfate anion ([HSO4]-). Electron transfer both within the anion, and between the anion and cation of an ion pair were described using natural bond orbital theory. The energy values of -7.1375 and -2.8801 eV were related to HOMO and LUMO orbitals, respectively.

  11. Contribution to the study of the reduction of sulfate by the yolk sac of the chicken embryo; Contribution a l'etude de la reduction du sulfate par le sac vitellin de l'embryon de poulet

    Bourgeois, Claude

    1958-11-15

    This academic reports addresses additional information obtained about the reduction of sulfate into sulphite by the yolk sac of a chicken embryo. Two important difficulties have been faced: the impossibility to isolate this reduction from reactions which immediately use the formed sulphite, and the impossibility to obtain an acellular preparation able to reduce the sulfate. Then, the problem of reduction of sulfate into sulphite by the yolk sac is associated with the problem of permeability of yolk sac cells to the studied substances. Thus, the author studied whether other animal species could provide a better material than the chicken embryo for this study of sulfate reduction. It appears that some vertebrate embryos present some evidence of sulphur metabolism similar to that of chicken embryo. However, this last one revealed to be the most favourable for the study. The author reports the study of the evolution of the reduction activity of the yolk sac sulfate with respect to the embryo age, and the effect of some metabolic inhibitors on this activity [French] Dans le present travail nous avons obtenu quelques renseignements concernant la reduction du sulfate en sulfite par l'embryon de poulet. Cette etude a ete menee, a l'aide de substances marquees par le soufre {sup 35}S, par les methodes qui avaient permis anterieurement a Chapeville et Fromageot de mettre en evidence cette reaction et les reactions qui lui font suite au cours de la synthese des aminoacides soufres. Pour apprecier la reduction du sulfate {sup 35}S, nous avons mesure la quantite d'acide cysteique {sup 35}S et de taurine {sup 35}S formes a partir du sulfite {sup 35}S. Appliquant ces techniques aux embryons d'especes animales variees, nous avons constate que quelques embryons de vertebres etaient capables d'utiliser le sulfite a la synthese d'acide cysteique: les embryons de roussette et de rat avec un rendement faible, l'embryon d'un passereau de la famille des turdides, comme celui du poulet

  12. Studies on the feeding of cupric sulfate pentahydrate and cupric citrate to broiler chickens.

    Pesti, G M; Bakalli, R I

    1996-09-01

    Male commercial broiler strain chickens were fed either a control diet (based on corn and soybean meal) or the control diet supplemented with cupric sulfate pentahydrate or cupric citrate in seven experiments (six in floor pens, one in wire-floored batteries). In Experiment 1, feeding 125 or 250 mg/kg copper increased growth (4.9%) and decreased feed conversion ratios (3.4%), total plasma cholesterol (40.2%), and breast muscle cholesterol (37.0%). Feeding 375 mg/kg copper was without further beneficial effect. In Experiment 2, withdrawing growth promoting supplements of copper from the feed for the last 7 d caused a significant (P copper caused only small increases in tissue copper levels: 0.36 vs 0.41 mg/kg for breast meat, and 0.48 vs 0.60 mg/kg for thigh meat, respectively. Litter copper accumulations in these experiments were similar to those of earlier reports. Breast muscle cholesterol was reduced by feeding 125 mg/kg supplemental copper from cupric citrate (27.84 mg/100 g) or 125 mg supplemental copper from cupric sulfate pentahydrate (25.32 mg/100 g) compared to broilers fed the control diet (43.92 mg/100 g). Cupric citrate was efficacious for growth promotion at lower copper levels than cupric sulfate pentahydrate, resulting in reduced litter copper.

  13. Physiological and Biophysical Studies on Gamma Irradiated Rat Treated with Dehydroepiandrosterone Sulfate (DHEAS)

    Hamza, G.R.A.

    2015-01-01

    Dehydroepiandrosterone Sulfate (DHEAS) is an adrenal hormone, and is the most abundant circulatory steroid hormone in the body. Serum DHEAS concentration peaks at around age 25 years, displaying a significant decrease with age linked with some pathological changes. Objective: This study was performed to investigate the effect(s) of DHEAS oral administration, and its possible prophylactic and/or mitigating roles against γ-irradiation-induced disorders in the irradiated rat. Experimental Animals and Design: Five groups of male Albino rats were used: 1- Control: untreated group. 2- Irradiated: animals exposed to a single dose of whole-body γ-irradiation (6 Gy). 3- DHEAS group: given a single dose of DHEAS (20 mg/100 g b. wt.), intra gastrically. 4-DHEAS + Irrad. group: given a single dose of DHEAS, 2 hrs before irradiation. 5- Irrad.+ DHEAS group: given DHEAS, 2 hrs after irradiation. Blood and testicular tissue samples were collected after one day, one week and two weeks post irradiation or DHEAS treatment. Parameters Measured: Plasma levels of triiodothyronine (T 3 ), thyroxin (T 4 ), thyrotropin (TSH), testosterone, acid phosphatase (ACP), triglycerides (TG), total cholesterol, high density lipoprotein-cholesterol (HDL-Ch), low density lipoprotein-cholesterol (LDL-Ch) were determined, and the atherogenic index (AI) was calculated. Reduced glutathione (GSH) content and malondialdehyde (MDA) levels were measured in blood and testes. A complete blood picture and some biophysical properties were also examined. Results: DHEAS administration pre-irradiation, and to a lesser magnitude, post-irradiation, improved the disturbances induced by irradiation in the plasma levels of the tested parameters: tT 3 , tT 4 , and TSH, testosterone and the lipid profile, showing almost normalization of the AI. Beneficial effects were also observed in the hematological picture, blood viscosity and conductivity. DHEAS elevated GSH levels and decreased lipid peroxidation (LPO) in blood

  14. Studies on the feeding of cupric sulfate pentahydrate, cupric citrate, and copper oxychloride to broiler chickens.

    Ewing, H P; Pesti, G M; Bakalli, R I; Menten, J F

    1998-03-01

    Male commercial broiler strain chickens were fed either a control diet (based on corn and soybean meal) or the control diet supplemented with cupric sulfate pentahydrate, copper oxychloride, or cupric citrate in two experiments conducted in floor pens. In Experiment 1, feeding copper at 125 mg/kg diet for 42 d significantly increased broiler growth; and the response from cupric citrate was significantly better than either cupric sulfate or copper oxychloride. In Experiment 2, the inclusion of copper from cupric citrate was reduced to 63 mg/kg and the length of the experiment was increased to 56 d. Cupric sulfate pentahydrate and copper oxychloride treatments increased weight gain by 4.9% and cupric citrate increased weight gain by 9.1%. The feed conversion ratios (grams of feed:grams of gain of live birds) in the birds fed copper were not significantly different from those fed the basal diet (P > 0.05) unless corrections were made for the weights of the dead birds; the adjusted feed conversion ratios (grams of feed:grams of gain of live birds + grams of gain of mortalities) for the copper-treated birds in Experiments 1 and 2 were 5.2 and 7.6% lower, respectively, than the ratios of birds fed the basal diets. Plasma copper levels increased in supplemented chicks by 35% in Experiment 1 and 24% in Experiment 2. Liver copper levels in both experiments were increased by 26% with copper supplementation. Mortality was not affected by dietary treatment in either experiment (P > 0.05).

  15. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    Friedrich, Leidi C.; Silva, Volnir O.; Moreira Jr, Paulo F.; Tcacenco, Celize M.; Quina, Frank H.

    2013-01-01

    Aggregation numbers (N Ag) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40º C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles (γ = 0.11-0.15, where γ is the slope of a plot of log aggregation number vs. log [Yaq] and [Yaq] is the sodium counter...

  16. Electrochemical study in the molten sodium acid sulphate - potassium acid sulphate eutectic; Etude electrochimique dans l'eutectique fondu sulfate acide de sodium - sulfate acide de potassium

    Le Ber, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The general properties of the NaHSO{sub 4} - KHSO{sub 4} molten eutectic resemble those of neutral sulphates and those of concentrated H{sub 2}SO{sub 4}. We have been able to show the existence in solution of the ions HSO{sup -}{sub 4} SO{sup 2-}{sub 4}, and H{sub 3}O{sup +}, these last being formed by the action of the HSO{sup -}{sub 4} ions on dissolved H{sub 2}O. The electro-active zone with a polished platinum electrode is limited in oxidation by the ions H{sub 3}O{sup +} and SO{sup 2-}{sub 4}, and in reduction by the protons of HSO{sup -}{sub 4}. We have compared the electro-active zones obtained with different electrodes (Ag-Au-graphite-mercury). We have considered the dissolution of a few metallic oxides and halides. This work shows the role as O{sup 2-} ion acceptors of HSO{sup -}{sub 4} ions. We have undertaken an electro-chemical study of a few oxido-reduction Systems: H{sup +} / H{sub 2}, Ag{down_arrow} / Ag (1), the vanadium and uranium Systems, those of mercury Hg{down_arrow} / Hg{sup 2-}{sub 2} and of gold Au/Au{sup 3+}, then of the attack by the solvent of a few common metals such as aluminium, iron, copper and nickel. The study of silver Systems has made it possible to obtain the solubility products of AgCl and AgBr and to consider the possibility of coulometric titration Cl{sup -} ions with Ag{sup +} ions. We have shown the existence of various chemical species of vanadium which may exist in the molten eutectic. (author) [French] Les proprietes generales de l'eutectique NaHSO{sub 4} - KHSO{sub 4} fondu s'apparentent a celles des sulfates neutres et a celles de H{sub 2}SO{sub 4} concentre. Nous avons pu mettre en evidence l'existence en solution d'ions HSO{sup -}{sub 4}, SO{sup 2-}{sub 4},et H{sub 3}O{sup +}, ces derniers resultats de l'action des ions HSO{sup -}{sub 4} sur H{sup 2}O dissoute. Le domaine d'electroactivite a une electrode de platine poli est limite en oxydation par les ions H{sub 3}O{sup +} + SO{sup 2-}{sub 4} et en reduction par les

  17. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    Friedrich, Leidi C.; Silva, Volnir O.; Quina, Frank H.; Moreira Junior, Paulo F.; Tcacenco, Celize M.

    2013-01-01

    Aggregation numbers (N Ag ) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40 deg C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles (γ = 0.11-0.15, where γ is the slope of a plot of log aggregation number vs. log [Y aq ] and [Y aq ] is the sodium counterion concentration free in the intermicellar aqueous phase) is found to be significantly lower than that of sodium alkyl sulfate micelles (γ ca. 0.25), a difference attributed to the larger headgroup size of SLES. The I 1 /I 3 vibronic intensity ratio and the rate constant for intramicellar quenching of pyrene show that the pyrene solubilization microenvironment and the intramicellar microviscosity are insensitive to micelle size or the presence of added salt. (author)

  18. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    Friedrich, Leidi C.; Silva, Volnir O.; Quina, Frank H., E-mail: quina@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Quimica; Moreira Junior, Paulo F. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Departamento de Engenharia Quimica; Tcacenco, Celize M. [Fundacao Instituto de Ensino para Osasco (FIEO/UNIFIEO), SP (Brazil). Centro Universitario FIEO. Centro de Estudos Quimicos

    2013-02-15

    Aggregation numbers (N{sub Ag}) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40 deg C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles ({gamma} = 0.11-0.15, where {gamma} is the slope of a plot of log aggregation number vs. log [Y{sub aq}] and [Y{sub aq}] is the sodium counterion concentration free in the intermicellar aqueous phase) is found to be significantly lower than that of sodium alkyl sulfate micelles ({gamma} ca. 0.25), a difference attributed to the larger headgroup size of SLES. The I{sub 1}/I{sub 3} vibronic intensity ratio and the rate constant for intramicellar quenching of pyrene show that the pyrene solubilization microenvironment and the intramicellar microviscosity are insensitive to micelle size or the presence of added salt. (author)

  19. Ion Exchange Studies for Removal of Sulfate from Hanford Tank Waste Envelope C (241-AN-107) Using SuperLig 655 Resin

    Kurath, D.E.; Bontha, J.R.; Blanchard, D.L.; Fiskum, S.K.; Rapko, B.M.

    2000-01-01

    BNFL Inc. is evaluating various pretreatment technologies to mitigate the impacts of sulfate on the LAW vitrification system. One pretreatment technology for separating sulfate from LAW solutions involves the use of SuperLig(reg. sign) 655 (SL-655), a proprietary ion exchange material developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. This report describes testing of SL-655 with diluted ([Na] approximately 5 M) waste from Hanford Tank 241-AN-107 at Battelle, Pacific Northwest Division. Batch contact studies were conducted from 4 to 96 hours to determine the sulfate distribution coefficient and reaction kinetics. A small-scale ion exchange column test was conducted to evaluate sulfate removal, loading, breakthrough, and elution from the SL-655. In all of these tests, an archived 241-AN-107 tank waste sample (pretreated to remove Cs, Sr, and transuranics elements) was used. The experimental details and results are described in this report. Under the test conditions, SL-655 was found to have no significant ion exchange affinity for sulfate in this matrix. The batch contact study resulted in no measurable difference in the aqueous sulfate concentration following resin contact (K d ∼ 0). The column test also demonstrated SL-655 had no practical affinity for sulfate in the tested matrix. Within experimental error, the sulfate concentration in the column effluent was equal to the concentration in the feed after passing 3 bed volumes of sample through the columns. Furthermore, some, if not all, of the decreased sulfate concentration in these first three column volumes of effluent can be ascribed to mixing and dilution of the 241-AN-107 feed with the interstitial liquid present in the column at the start of the loading cycle. Finally, ICP-AES measurements on the eluate solutions showed the presence of barium as soon as contact with the feed solution is completed. Barium is a metal not detected in the feed solution. Should the loss of barium be

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

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

    2013-01-01

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

  1. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor.

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-03-29

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor.

  2. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-01-01

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor. PMID:27021522

  3. An Exploratory Study on the Pathways of Cr (VI) Reduction in Sulfate-reducing Up-flow Anaerobic Sludge Bed (UASB) Reactor

    Qian, Jin; Wei, Li; Liu, Rulong; Jiang, Feng; Hao, Xiaodi; Chen, Guang-Hao

    2016-03-01

    Electroplating wastewater contains both Cr (VI) and sulfate. So Cr (VI) removal under sulfate-rich condition is quite complicated. This study mainly investigates the pathways for Cr (VI) removal under biological sulfate-reducing condition in the up-flow anaerobic sludge bed (UASB) reactor. Two potential pathways are found for the removal of Cr (VI). The first one is the sulfidogenesis-induced Cr (VI) reduction pathway (for 90% Cr (VI) removal), in which Cr (VI) is reduced by sulfide generated from biological reduction of sulfate. The second one leads to direct reduction of Cr (VI) which is utilized by bacteria as the electron acceptor (for 10% Cr (VI) removal). Batch test results confirmed that sulfide was oxidized to elemental sulfur instead of sulfate during Cr (VI) reduction. The produced extracellular polymeric substances (EPS) provided protection to the microbes, resulting in effective removal of Cr (VI). Sulfate-reducing bacteria (SRB) genera accounted for 11.1% of the total bacterial community; thus they could be the major organisms mediating the sulfidogenesis-induced reduction of Cr (VI). In addition, chromate-utilizing genera (e.g. Microbacterium) were also detected, which were possibly responsible for the direct reduction of Cr (VI) using organics as the electron donor and Cr (VI) as the electron acceptor.

  4. The removal of Tartrazine dye by modified Alumina with sodium dodecyl sulfate from aqueous solutions: equilibrium and thermodynamic studies

    A. Parchebaf Jadid

    2017-11-01

    Full Text Available Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver and blood toxicity. The goal of this study was investigating the efficiency of improved alumina by sodium dodecyl sulfate (SDS in eliminating Tartrazine from aqueous environments. In this research, the impact of effective parameters such as initial concentration of Tartrazine, time, pH, alumina dose and SDS value were studied in order to approach an optimal condition for eliminating the color. Also, absorption behavior was evaluated by Freundlich and Langmuir isotherms. The highest efficiency of Tartrazine elimination in the solution resulted in optimal pH of 2, the amount of adsorbent 1.5 g/L, 16 min duration and value 0.04 SDS g/l which was obtained for dye concentration 5 mg/L about 94.13%. Also, results suggested that Tartrazine absorption follows Langmuir isotherm (R2 = 0.9867. Obtained results from thermodynamic studies such as Gibbs free energy (-5.728 Kj/mol and enthalpy (-85.86 Kj/mol and entropy (-271.102 J/mol.K also suggested that the absorption process was exothermic. The results of this research suggested that improved alumina by sodium dodecyl sulfate had a relative good capability in Tartrazine elimination from aqueous environments. Thus

  5. XRD, SEM and infrared study into the intercalation of sodium hexadecyl sulfate (SHS) into hydrocalumite.

    Zhang, Ping; Wang, Tianqi; Zhang, Longlong; Wu, Daishe; Frost, Ray L

    2015-12-05

    Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.78 nm to 2.74 nm). The bands of C-H stretching vibrations of SHS were observed in the near-infrared spectra, which indicated that the resulting products were indeed CaAl-LDH-SHS. In addition, the bands of water stretching vibrations and OH groups shifted to higher wavenumbers when SHS was intercalated into CaAl-LDH-Cl interlayer space. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. A validated HPTLC method for determination of terbutaline sulfate in biological samples: Application to pharmacokinetic study

    Faiyazuddin, Md.; Rauf, Abdul; Ahmad, Niyaz; Ahmad, Sayeed; Iqbal, Zeenat; Talegaonkar, Sushma; Bhatnagar, Aseem; Khar, Roop K.; Ahmad, Farhan J.

    2011-01-01

    Terbutaline sulfate (TBS) was assayed in biological samples by validated HPTLC method. Densitometric analysis of TBS was carried out at 366 nm on precoated TLC aluminum plates with silica gel 60F254 as a stationary phase and chloroform–methanol (9.0:1.0, v/v) as a mobile phase. TBS was well resolved at RF 0.34 ± 0.02. In all matrices, the calibration curve appeared linear (r2 ⩾ 0.9943) in the tested range of 100–1000 ng spot−1 with a limit of quantification of 18.35 ng spot−1. Drug recovery f...

  7. Study of the phase transition in lithium potassium rubidium sulfate system

    Hamed, A. E.; Abd. El-Aziz, Y. M.; Madi, N. K.; Kassem, M. E.

    1998-10-01

    Specific heat, Cp, measurements have been performed in lithium potassium rubidium sulfate, (Li 0.5- x/2 K 0.5- x/2 Rb x) 2SO 4, system in a wide range of Rb 2SO 4 content ( x) ( x=0 up to x=10%). Measurements were made between 300 and 800 K with special attention paid to the phase transition at 708 K. It is shown that for small contents, ( x), ( x=0.2 up to x=2%) quantitative changes in the temperature dependence of specific heat Cp( T) around the transition point, T1, are observed. A larger content, x, results in essential changes in the critical behavior of Cp( T) and a considerable change in the phase transition accompanied by a progressive decrease in the thermodynamic parameters. The ratios of the Landau expansion coefficients change as the content of Rb 2SO 4 increases.

  8. An experimental study on sterilized barium sulfate (BaSO4) for vertebroplasty

    Chen Long; Ni Caifang; Ding Yi; Wang Yijin

    2005-01-01

    Objective: To search the proper sterilization method of barium for vertebroplasty. Methods: Perfusion agents were classified into two groups with ratio of powder/liquid(g/ml) as 3:2, and the percentage of BsSO 4 in powder was 20%. The barium powder in one group was sterilized by dry-heat and by ethylene oxide in the other. The barium powder of each group was germicultured and the polymerization time, CT value, strength and stiffness were measured respectively including 6 samples. Two independent-samples t text was used for analysis. Results: The germiculture in each group was negative. The difference in polmerization time and CT value of each group were not significant (P>0.05), while the strength and stiffness were significantly different (P<0.05). Conclusions: Sterilized effects of two groups were satisfied but the dry-heat barium sulfate is superior, more suitable for vertebroplasty. (authors)

  9. Theoretical Study of Infrared and Raman Spectra of Hydrated Magnesium Sulfate Salts

    Chaban, Galina M.; Huo, Winifred M.; Lee, Timothy J.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Harmonic and anharmonic vibrational frequencies, as well as infrared and Raman intensities, are calculated for MgSO4.nH20 (n=1-3). Electronic structure theory at the second order Moller-Plesset perturbation theory (MP2) level with a triple-zeta + polarization (TZP) basis set is used to determine the geometry, properties, and vibrational spectra of pure and hydrated MgSO4 salts. The direct vibrational self-consistent field (VSCF) method and its correlation corrected (CC-VSCF) extension are used to determine anharmonic corrections to vibrational frequencies and intensities for the pure MgSO4 and its complex with one water molecule. Very significant differences are found between vibrational of water molecules in complexes with MgSO4 and pure water. Some of the O-H stretching frequencies are shifted to the red very significantly (by up to 1500-2000/cm) upon complexation with magnesium sulfate. They should be observed between 1700 and 3000/cm in a region very different from the corresponding O-H stretch frequency region of pure water (3700-3800/cm). In addition, the SO2 stretching vibrations are found at lower frequency regions than the water vibrations. They can serve as unique identifiers for the presence of sulfate salts. The predicted infrared and Raman spectra should be of valuable help in the design of future missions and analysis of observed data from the ice surface of Jupiter's moon Europa that possibly contains hydrated MgSO4 salts.

  10. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis.

    Li, Lian; Li, Yan; Feng, Danyang; Xu, Linghua; Yin, Fengxin; Zang, Hengchang; Liu, Chunhui; Wang, Fengshan

    2016-10-11

    Chondroitin sulfate (CS) plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs) and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV) spectroscopy, high-performance liquid chromatography (HPLC), size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O) had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA) was investigated by destabilization of the medial meniscus (DMM) model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  11. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis

    Lian Li

    2016-10-01

    Full Text Available Chondroitin sulfate (CS plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV spectroscopy, high-performance liquid chromatography (HPLC, size exclusion chromatography-multiangle laser light scattering (SEC-MALLS and nuclear magnetic resonance (NMR spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA was investigated by destabilization of the medial meniscus (DMM model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  12. Whole Grain Consumption Increases Gastrointestinal Content of Sulfate-Conjugated Oxylipins in Pigs − A Multicompartmental Metabolomics Study

    Ingerslev, Anne Krog; Karaman, İbrahim; Bağcıoğlu, Murat

    2015-01-01

    The effects of increased intake of dietary fiber as either arabinoxylan (AX) or resistant starch (RS) compared to a typical low dietary fiber Western-style diet (WSD) on the metabolomics responses was studied in gastrointestinal content and tissue, peripheral plasma and urine using a multicompart...... of multicompartmental metabolomics offers information about the correlations between the compartments of the digestive system, providing additional insight into effects of increased whole grain intake.......The effects of increased intake of dietary fiber as either arabinoxylan (AX) or resistant starch (RS) compared to a typical low dietary fiber Western-style diet (WSD) on the metabolomics responses was studied in gastrointestinal content and tissue, peripheral plasma and urine using......, and a low dietary fiber intake were detected using multi block analysis. This study provides insight into microbial fermentation products in the gastrointestinal tract, and suggests a potential role in sulfate conjugation of metabolites on the bioavailability of ingested nutrients. In addition, the use...

  13. A study on super-sulfated cement using Dinh Vu phosphogypsum

    Lam, Nguyen Ngoc

    2018-04-01

    Super-sulfated cement (SSC) is a newly developed unburnt cementitious material. It is a kind of environmental-friendly cementitious material due to its energy-saving, carbon emission reducing, and waste-utilization. It mainly composes of phosphogysum (PG) and ground granulated blast furnace slag (GFS), with a small amount of cement. In Vietnam, the Diammonium Phosphate DAP – Dinh Vu fertilizer plant in Dinh Vu industrial zone in the northern port city of Hai Phong – has discharged millions of tons of solid waste containing gypsum after 9 years of operation. The waste has changed the color of the water, eroded metal and destroyed fauna and floral systems in the surrounding area. Notably, according to the environmental impact assessment, the gypsum landfill area is supposed to be 13 hectares and the storage time reaches up to five years. This paper presents the experimental results on SSC using a high amount of Dinh Vu phosphogypsum and GFS in comparison with those of ordinary Portland cement (PC). The results show that the setting time of SSC is much longer than that of Portland cement but the compressive strength of SSC can be obtained 45-50 MPa at the age of 28 days, similar to that of the control sample using 100% PC40, and 69MPa at the age of 90 days. This value even exceeds the compressive strength of the PC40 cement.

  14. Spectral study of interaction between chondroitin sulfate and nanoparticles and its application in quantitative analysis

    Ma, Yi; Wei, Maojie; Zhang, Xiao; Zhao, Ting; Liu, Xiumei; Zhou, Guanglian

    2016-01-01

    In this work, the interaction between chondroitin sulfate (CS) and gold nanoparticles (GNPs) and silver nanoparticles (SNPs) was characterized for the first time. Plasma resonance scattering (PRS) and plasma resonance absorption (PRA) were used to investigate the characteristics of their spectrum. The results suggested that the CS with negative charge could interact with metal nanoparticles with negative charge and the adsorption of CS on the surface of SNPs was more regular than that of GNPs. The resonance scattering spectra also further confirmed the interaction between CS and SNPs. A new method for detection of CS based on the interaction was developed. CS concentrations in the range of 0.02-3.5 μg/mL were proportional to the decreases of absorbance of SNPs. Compared with other reported methods, the proposed method is simple and workable without complex process, high consumption and expensive equipments. The developed method was applied to the determination of the CS contents from different biological origins and the results were compared with those obtained by the method of Chinese Pharmacopeia. The effects of matrix in plasma and other glycosaminoglycans on the determination of CS were also investigated. The results showed that a small quantity of blood plasma had no effect on the determination of CS and when the concentration ratio of CS to heparin was more than 10:1, the influence of heparin on the detection of CS could be ignored. This work gave a specific research direction for the detection of CS in the presence of metal nanoparticles.

  15. Studies of the effect of ethanol and sodium chloride on the micellization of sodium dodecyl sulfate by gel filtration

    Suzuki, H.

    1976-06-01

    The effects of the addition of ethanol and sodium chloride to aqueous solutions of sodium dodecyl sulfate (SDS) were studied by the gel-filtration method. With an increase in the concentration of ethanol, the CMC decreased and then increased after passing a minimum, while the micellar weight increased and then decreased, showing a corresponding maximum. Above about 40 vol percent ethanol, no micelle formation was observed. The micellar weight and aggregation number in the presence of ethanol were measured in the SDS concentration range of a constant elution rate of micelles. A decrease in the CMC and an increase in the micellar weight of SDS were observed with an increase in the concentration of NaCl from 0 to 10 mmol/l. The gel-filtration study enabled us to make a direct experimental confirmation of the effects of ethanol and NaCl on the micelle formation of SDS.

  16. Discovery of a Heparan sulfate 3- o -sulfation specific peeling reaction

    Huang, Yu; Mao, Yang; Zong, Chengli; Lin, Cheng; Boons, Geert Jan|info:eu-repo/dai/nl/088245489; Zaia, Joseph

    2015-01-01

    Heparan sulfate (HS) 3-O-sulfation determines the binding specificity of HS/heparin for antithrombin III and plays a key role in herpes simplex virus (HSV) infection. However, the low natural abundance of HS 3-O-sulfation poses a serious challenge for functional studies other than the two cases

  17. High-Density Near-Field Readout Using Solid Immersion Lens Made of KTaO3 Monocrystal

    Shinoda, Masataka; Saito, Kimihiro; Kondo, Takao; Furuki, Motohiro; Takeda, Minoru; Nakaoki, Ariyoshi; Sasaura, Masahiro; Fujiura, Kazuo

    2006-02-01

    We developed solid immersion lenses made of a KTaO3 monocrystal. The refractive index of KTaO3 is 2.382 at a wavelength of 405 nm. Using KTaO3 as the raw material of a solid immersion lens, we could design an effective numerical aperture of 2.20. We observed an eye pattern of a 150 GB capacity with a 130 nm track pitch and a 47.6 nm bit length. The areal density is 104.3 Gbit/in.2.

  18. Experimental study of the density and viscosity of 1-ethyl-3-methylimidazolium ethyl sulfate

    Schmidt, H.; Stephan, M.; Safarov, J.; Kul, I.; Nocke, J.; Abdulagatov, I.M.; Hassel, E.

    2012-01-01

    Highlights: ► Density of the ionic liquid [EMIM][EtSO 4 ]. ► Viscosity of the ionic liquid [EMIM][EtSO 4 ]. ► Thermodynamic properties of ionic liquid [EMIM][EtSO 4 ]. ► Equation of state of ionic liquid [EMIM][EtSO 4 ]. - Abstract: Density and viscosity of 1-ethyl-3-methylimidazolium ethyl sulfate [EMIM][EtSO 4 ] have been measured over the temperature range from (283.15 to 413.15) K and at pressures up to 140 MPa and in the temperature range from (283.15 to 373.15) K at 0.1 MPa, respectively. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be (0.01 to 0.08)%, 0.1%, 15 mK, and 0.35%, respectively. The measurements were carried out with an Anton–Paar DMA HPM vibration-tube densimeter and a fully automated SVM 3000 Anton–Paar rotational Stabinger viscometer. The vibration-tube densimeter was calibrated using various reference fluids, double-distilled water, methanol, toluene, and aqueous NaCl solutions. An empiric equation of state for [EMIM][EtSO 4 ] has been developed using the measured (p, ρ, T) data. This equation was used to calculate the various thermodynamic properties of the IL and for compare with measured properties (speed of sound and enthalpy). Theoretically based Arrhenius–Andrade and Vogel–Tamman–Fulcher type equations were use to describe of the temperature dependence of measured viscosities for [EMIM][EtSO 4 ]. All measured properties were detailed compared with the reported data by other author.

  19. Operando studies of all-vanadium flow batteries: Easy-to-make reference electrode based on silver-silver sulfate

    Ventosa, Edgar; Skoumal, Marcel; Vázquez, Francisco Javier; Flox, Cristina; Morante, Joan Ramon

    2014-12-01

    In-depth evaluation of the electrochemical performance of all-vanadium redox flow batteries (VRFBs) under operando conditions requires the insertion of a reliable reference electrode in the battery cell. In this work, an easy-to-make reference electrode based on silver-silver sulfate is proposed and described for VRFBs. The relevance and feasibility of the information obtained by inserting the reference electrode is illustrated with the study of ammoxidized graphite felts. In this case, we show that the kinetic of the electrochemical reaction VO2+/VO2+ is slower than that of V2+/V3+ at the electrode. While the slow kinetics at the positive electrode limits the voltage efficiency, the operating potential of the negative electrode, which is outside the stability widow of water, reduces the coulombic efficiency due to the hydrogen evolution.

  20. Design and Construction of Experiment for Direct Electron Irradiation of Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakho [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, Thad [Argonne National Lab. (ANL), Argonne, IL (United States); Sun, Zaijing [Argonne National Lab. (ANL), Argonne, IL (United States); Wardle, Kent E. [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-10-01

    Argonne is assisting SHINE Medical Technologies in developing SHINE, a system for producing fission-product 99Mo using a D/T-accelerator to produce fission in a non-critical target solution of aqueous uranyl sulfate. We have developed an experimental setup for studying thermal-hydraulics and bubble formation in the uranyl sulfate solution to simulate conditions expected in the SHINE target solution during irradiation. A direct electron beam from the linac accelerator will be used to irradiate a 20 L solution (sector of the solution vessel). Because the solution will undergo radiolytic decomposition, we will be able to study bubble formation and dynamics and effects of convection and temperature on bubble behavior. These experiments will serve as a verification/ validation tool for the thermal-hydraulic model. Utilization of the direct electron beam for irradiation allows homogeneous heating of a large solution volume and simplifies observation of the bubble dynamics simultaneously with thermal-hydraulic data collection, which will complement data collected during operation of the miniSHINE experiment. Irradiation will be conducted using a 30-40 MeV electron beam from the high-power linac accelerator. The total electron-beam power will be 20 kW, which will yield a power density on the order of 1 kW/L. The solution volume will be cooled on the front and back surfaces and central tube to mimic the geometry of the proposed SHINE solution vessel. Also, multiple thermocouples will be inserted into the solution vessel to map thermal profiles. The experimental design is now complete, and installation and testing are in progress.

  1. Contribution to the study of the role of sulfate-reducing bacteria in bio-corrosion phenomenon

    Chatelus, C.

    1987-11-01

    By their metabolic activities of hydrogen consumption and of sulfides production, the sulfate-reducing bacteria are the main bacteria responsible of the metallic corrosion phenomena in the absence of oxygen. A physiological and enzymatic study of some Desulfovibrio has contributed to the understanding of the role of these bacteria in the anaerobic bio-corrosion phenomena. Desulfovibrio (D.) vulgaris in organic medium, after having oxidized the lactate, consumes the hydrogen formed by the electrochemical reaction of iron dissolution. The Desulfovibrio can be responsible either of a corrosion by a direct contact with the metal in using the H 2 layer formed at its surface, (bacteria are then adsorbed at the surface because of an iron sulfide crystalline lattice), or of a distant corrosion in consuming the dissolved or gaseous hydrogen. As their hydrogenases can be stable in time independently of the cellular structure (D. vulparis) and active at high temperatures (to 70 C - 75 C) (D. baculatus), these bacteria can act in conditions incompatible with the viability of cells but compatible with the enzymatic expression. A study in terms of temperature has shown that inside the mesophilic group of the Desulfovibrio, the behaviour towards this parameter is specific to each bacteria, that accounts for the permanent presence of the representatives of this population in sites where the temperature variations are important. A change of some degrees Celsius can induce modifications in the yields of bacteria growth and by a consequence in variations in the corrosion intensity. Moreover, sulfate D. multispirans can reduce with specific velocities of different growth, the nitrate, the nitrite and the fumarate. Some sulfato-reducing could then adapt themselves to the variations of concentrations in electron acceptors and metabolize the oxidized substances used as biocides too. The choice of an electron acceptor rather than another do not depend uniquely of the specificity of the

  2. Influence of sulfate-reducing bacteria on the corrosion of steel in seawater: laboratory and in situ study

    Benbouzid-Rollet, N.

    1993-01-01

    A fouling reactor was designed to study, the influence of a mixed bio-film on AISI 316 L stainless steel. The bio-film was formed on the steel surface by the fermentative bacterium Vibrio natriegens. The sulfate-reducing bacterium Desulfovibrio vulgaris was then introduced in the reactor and colonized the surface, constituting approximately 5 % of the total population. The settlement of an anaerobic bacterium in the bio-film shows in it the existence of anaerobic micro-niches. Stainless steel electrochemical behavior was analyzed using open circuit potential and potentiodynamic polarization curves. Growth of the bio-film does not induce corrosion, but seems to change the cathodic oxygen reduction kinetics, diminishing the corrosion hazard. This effect increases when D. vulgaris grows in the bio-film. An ennobling of the open circuit potential was observed, similar to field cases already described. A case of drilling corrosion of carbon steel in a harbour area showed the characteristics of anaerobic corrosion related to sulfate-reducing bacteria. The total cultivatable SRB population was quantified and metabolic types were enumerated using specific electron donors. A maximum cell density of 1,1 x 10 8 cells/ cm 2 was estimated, revealing a very important growth of SRB on surfaces. Population structure was different in corroded and non-corroded areas. In corroded area, SRB utilizing benzoate and propionate were more abundant. A strain belonging to the sporulating genus Desulfotomaculum was isolated using these substrates, suggesting a partial aeration in the area of hole appearance. However, in vitro corrosion assays showed that the bacterial population sampled in this area induced a consequent weight loss of steel coupons, in the absence of oxygen. This was observed only with a diversified population, similar to that present in situ. It could not be reproduced with a mixed culture of two purified strains. (author)

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

    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.

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

    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.

  5. Syndecan heparan sulfate proteoglycans

    Gomes, Angélica Maciel; Sinkeviciute, Dovile; Multhaupt, Hinke A.B.

    2016-01-01

    discuss how, in partial catabolic processes, new roles for HSPGs emerge that affect cell behavior. Examples from tumor studies are emphasized, since HSPGs may be altered in composition and distribution and may also represent targets for the development of new therapeutics....... signaling can therefore be complex, but it is now known that syndecans are capable of independent signaling. This review is divided in two sections, and will first discuss how the assembly of heparan sulfate, the anabolic process, encodes information related to ligand binding and signaling. Second, we...

  6. Co-existence of Methanogenesis and Sulfate Reduction with Common Substrates in Sulfate-Rich Estuarine Sediments

    Michal Sela-Adler

    2017-05-01

    Full Text Available The competition between sulfate reducing bacteria and methanogens over common substrates has been proposed as a critical control for methane production. In this study, we examined the co-existence of methanogenesis and sulfate reduction with shared substrates over a large range of sulfate concentrations and rates of sulfate reduction in estuarine systems, where these processes are the key terminal sink for organic carbon. Incubation experiments were carried out with sediment samples from the sulfate-methane transition zone of the Yarqon (Israel estuary with different substrates and inhibitors along a sulfate concentrations gradient from 1 to 10 mM. The results show that methanogenesis and sulfate reduction can co-exist while the microbes share substrates over the tested range of sulfate concentrations and at sulfate reduction rates up to 680 μmol L-1 day-1. Rates of methanogenesis were two orders of magnitude lower than rates of sulfate reduction in incubations with acetate and lactate, suggesting a higher affinity of sulfate reducing bacteria for the available substrates. The co-existence of both processes was also confirmed by the isotopic signatures of δ34S in the residual sulfate and that of δ13C of methane and dissolved inorganic carbon. Copy numbers of dsrA and mcrA genes supported the dominance of sulfate reduction over methanogenesis, while showing also the ability of methanogens to grow under high sulfate concentration and in the presence of active sulfate reduction.

  7. Long-term repetitive sodium lauryl sulfate-induced irritation of the skin: an in vivo study.

    Branco, Nara; Lee, Ivy; Zhai, Hongbo; Maibach, Howard I

    2005-11-01

    Skin may adapt to topical irritants through accommodation. This study focuses on long-term exposure to irritants and attempts to demonstrate accommodation. Sodium lauryl sulfate (SLS) induced irritant contact dermatitis at 3 concentrations (0.025% to 0.075%). Distilled water, acetone and an empty chamber served as controls. Experimental compounds were applied to forearms of 7 healthy volunteers for 24 hr before replacing by a fresh chamber for 6 non-consecutive weeks over 103 days. Possible accommodation was quantified by visual scoring (erythema and dryness) and by bioengineering parameters: transepidermal water loss (TEWL), capacitance, chromametry and laser Doppler flowmetry (LDF). Significant erythema, dryness, elevated TEWL, skin colour reflectance and LDF values occurred during the exposure periods. Upon repeat exposure, an immediate and augmented response in erythema, TEWL, skin colour reflectance and LDF developed. However, irritant skin changes were not sustained. Irritation parameters return to baseline after cessation of exposure. There was no evidence of sustained irritation or accommodation after the last exposure. Study findings do not document sustained accommodation or adaptive hyposensitivity after long-term repetitive irritant exposure under these test conditions. Alternative models should be developed to prove or disprove the accommodation hypothesis.

  8. Spectral-fluorescent study of the interaction of the polymethine dye probe Cyan 2 with chondroitin-4-sulfate

    Tatikolov, Alexander S.; Akimkin, Timofey M.; Panova, Ina G.; Yarmoluk, Sergiy M.

    2017-04-01

    The noncovalent interaction of the polymethine dye probe 3,3‧,9-trimethylthiacarbocyanine iodide (Cyan 2) with chondroitin-4-sulfate (C4S) in buffer solutions with different pH and in water in the absence of buffers has been studied by spectral-fluorescent methods. It has been shown that in all media studied, at relatively high concentrations, the dye is bound to C4S mainly as a monomer, which is accompanied by a steep rise of fluorescence (the intermediate formation of dye aggregates on the biopolymer is also observed). From the dependence of the fluorescence quantum yield on the concentration of C4S, the parameters of binding of the dye monomer to C4S were obtained: the effective binding constant K, the number of the monomeric C4S units n per one dye monomer bound to C4S, and the fluorescence quantum yield of the bound dye monomer Φfb. The dependence of Φfb (and K) on pH of the medium is not monotonic: it has a minimum in the region of neutral pH and a growth in the regions of acid and basic pH. This can be explained by changing the charge of a C4S macromolecule as a function of pH and related conformational alterations in the biopolymer, which can affect the rigidity of a dye molecule and the energy of its interaction with the biopolymer.

  9. The effects of moderate alcohol supplementation on estrone sulfate and DHEAS in postmenopausal women in a controlled feeding study

    Albanes Demetrius

    2004-09-01

    Full Text Available Abstract Background We have demonstrated that moderate alcohol consumption (15 g/d, 30 g/d for 8 weeks resulted in significantly increased levels of serum estrone sulfate and DHEAS in 51 postmenopausal women in a randomized, placebo-controlled trial. We now report on the relationships between serum estrone sulfate and dehydroepiandrosterone sulfate (DHEAS levels after 4 weeks of moderate alcohol supplementation, and compare the results to the 8 weeks data to elucidate time-to-effect differences. Methods Postmenopausal women (n = 51 consumed 0 (placebo, 15 (1 drink, and 30 (2 drinks g alcohol (ethanol/ day for 8 weeks as part of a controlled diet in a randomized crossover design. Blood samples were drawn at baseline, at 4 weeks and at 8 weeks. Changes in estrone sulfate and DHEAS levels from placebo to 15 g and 30 g alcohol per day were estimated using linear mixed models. Results and Discussion At week 4, compared to the placebo, estrone sulfate increased an average 6.9% (P = 0.24 when the women consumed 15 g of alcohol per day, and 22.2% (P = 0.0006 when they consumed 30 g alcohol per day. DHEAS concentrations also increased significantly by an average of 8.0% (P Conclusions These data indicate that the hormonal effects due to moderate alcohol consumption are seen early, within 4 weeks of initiation of ingestion.

  10. Modeling study of cloud droplet nucleation and in-cloud sulfate production during the Sanitation of the Atmosphere (SANA) 2 campaign

    Liu, Xiaohong; Seidl, Winfried

    1998-01-01

    Based upon the measurements of vertical profiles of gaseous SO2, H2O2, O3, and meteorological parameters from aircraft and of the aerosol chemical composition and gaseous NH3, HNO3, and SO2 at the surface in southeastern Germany (Melpitz) during the Sanitation of the Atmosphere (SANA) 2 campaign, realistic modeling of cloud droplet nucleation and in-cloud sulfate production was performed with an explicit microphysical cloud model with size-resolved chemistry and cloud top entrainment. For the fair weather cumulus observed during the measurements, the calculated cloud droplet number concentrations could be as high as 2000 cm-3 (and precloud aerosol sulfate up to 9.1 μg m-3), indicating strong sulfur pollution at Melpitz during the campaign. The in-cloud sulfate production is within 1.5-5.0 μg m-3, depending on the initial gaseous NH3 concentration in the parcel. This result shows the necessity of gaseous NH3 vertical profile measurements. Entrainment can reduce the cloud droplet number concentration and cause the distribution of in-cloud produced sulfate to shift toward larger particle sizes. Under the cases we studied, we do not find a significant effect of cloud top gaseous H2O2 entrainment on the in-cloud sulfate production. For the adiabatic cases the departure of bulk water H2O2 from the Henry's law equilibrium is very small. When entrainment included, however, bulk water H2O2 concentrations could be clearly less than the equilibrium values, and the deficiencies are higher (>20%) for droplets larger than 10 μm radius. Our results suggest that entrainment could be one of the important factors to account for the measured H2O2 deficiency in cloud water.

  11. Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats.

    Nazarizadeh, Ali; Asri-Rezaie, Siamak

    2016-08-01

    In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO4) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO4 (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO4 evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses.

  12. Hybrid soliwave technique for mitigating sulfate-reducing bacteria in controlling biocorrosion: a case study on crude oil sample.

    Mohd Ali, Muhammad Khairool Fahmy Bin; Abu Bakar, Akrima; Md Noor, Norhazilan; Yahaya, Nordin; Ismail, Mardhiah; Rashid, Ahmad Safuan

    2017-10-01

    Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and deep-water pipelines that result in costly repair and pipeline failure. Sulfate-reducing bacteria (SRB) are commonly known as the culprit of MIC. The aim of this work is to investigate the performance of combination of ultrasound (US) irradiation and ultraviolet (UV) radiation (known as Hybrid soliwave technique, HyST) at pilot scale to inactivate SRB. The influence of different reaction times with respect to US irradiation and UV radiation and synergistic effect toward SRB consortium was tested and discussed. In this research, the effect of HyST treatment toward SRB extermination and corrosion studies of carbon steel coupon upon SRB activity before and after the treatment were performed using weight loss method. The carbon steel coupons immersed in SRB sample were exposed to HyST treatment at different time of exposure. Additionally, Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy were used to investigate the corrosion morphology in verifying the end product of SRB activity and corrosion formation after treatment. Results have shown that the US irradiation treatment gives a synergistic effect when combined with UV radiation in mitigating the SRB consortium.

  13. Biphasic calcium sulfate dihydrate/iron-modified alpha-tricalcium phosphate bone cement for spinal applications: in vitro study

    Vlad, M D; Lopez, J; Torres, R; Barraco, M; Fernandez, E; Valle, L J; Poeata, I

    2010-01-01

    In this study, the cytocompatibility of new 'iron-modified/alpha-tricalcium phosphate (IM/α-TCP) and calcium sulfate dihydrate (CSD)' bone cement (IM/α-TCP/CSD-BC) intended for spinal applications has been approached. The objective was to investigate by direct-contact osteoblast-like cell cultures (from 1 to 14 days) the in vitro cell adhesion, proliferation, morphology and cytoskeleton organization of MG-63 cells seeded onto the new cements. The results were as follows: (a) quantitative MTT-assay and scanning electron microscopy (SEM) showed that cell adhesion, proliferation and viability were not affected with time by the presence of iron in the cements; (b) double immunofluorescent labeling of F-actin and α-tubulin showed a dynamic interaction between the cell and its porous substrates sustaining the locomotion phenomenon on the cements' surface, which favored the colonization, and confirming the biocompatibility of the experimental cements; (c) SEM-cell morphology and cytoskeleton observations also evidenced that MG-63 cells were able to adhere, to spread and to attain normal morphology on the new IM/α-TCP/CSD-BC which offered favorable substratum properties for osteoblast-like cells proliferation and differentiation in vitro. The results showed that these new iron-modified cement-like biomaterials have cytocompatible features of interest not only as possible spinal cancellous bone replacement biomaterial but also as bone tissue engineering scaffolds.

  14. Mud-bath therapy and oral glucosamine sulfate in patients with knee osteoarthritis: a randomized, controlled, crossover study.

    Peluso, Rosario; Caso, Francesco; Costa, Luisa; Sorbo, Dario; Carraturo, Nello; Di Minno, Matteo Nicola Dario; Carraturo, Federica; Oriente, Alfonso; Balestrieri, Umberto; Minicucci, Annamaria; Del Puente, Antonio; Scarpa, Raffaele

    2016-01-01

    To evaluate the efficacy and safety of combined treatment of mud-bath therapy and glucosamine crystalline sulfate (GlcN-S) in patients with knee osteoarthritis (OA). This study was a randomised, controlled, crossover investigation. Patients were randomly assigned (1:1) by the investigators to two groups, named group 1 and 2. Group 1 included twenty-three patients receiving oral GlcN-S treatment from the beginning of the study (T0) to the end of the 3rd month of treatment (T3) and a combined treatment of both mud-bath therapy and GlcN-S from T3 to the end of the study at six months (T6). Group 2 included twenty-two patients receiving a combined treatment of both mud-bath therapy and GlcN-S from T0 to T3 and that discontinued mud-bath therapy, receiving GlcN-S treatment alone, from T3 to T6. Primary endpoints of the study consisted of evaluating OA severity and activity at baseline and at follow-up visits. All 45 patients, eligible for the study, completed the period of the crossover. In group 1, no significant difference was shown in the comparison from T0 to T3, while from T3 to T6 most variables were significantly improved. In group 2, instead, the comparison between T0 and T3 showed a significant difference in different parameters. When comparing T3 and T6, despite an improvement of all the variables, no significant difference was shown. The association of GlcN-S and mud-bath therapy has a positive and safe role in improving pain, function and quality of life in knee OA patients.

  15. Photoinduced spin-orientation transition dynamics in Fe2+ - containing Y3Fe5O12 monocrystals

    Kovalenko, V.F.; Kuts, P.S.; Lyakhimets, S.N.

    1982-01-01

    The kinetic equations describing Fe 2 + ion redistribution between orientation-nonequivalent sites in the Y 3 Fe 5 O 12 monocrystal under the action of linearly-polarized light are solved. The method proposed permits to find Fe 2 + ion distribution over four types of orientation-nonequivalent sites using an introduced matrix. The spin-redistribution transition is shown to have a threshold character. The expression allowing one to perform a quantitative calculation of the time of creation of the threshold unbalance tau, is obtained. It is shown that tau is dependent on the initial unbalance of site population. A conclusion is made on the existence of sectors, in which the polarization vector of irradiatino. light is oriented and photoinduced changes do not occur even at infinitely large values of illimination time and intensity. The analysis of the theoretical results obtained and their comparison with the existing experimental results show good agreement

  16. Defects and color centers in SrTiD/sub 3/ monocrystals. [Pr, Nb Sm, Er, Tm additions

    Kulagin, N A

    1983-11-01

    Results are presented of investigation into crystal defects of nominally pure and activated SrTiO/sub 3/ monocrystals. It is shown that blue and yellow colour of the crystals is caused bt transition of some Ti/sup 4 +/ ions to Ti/sup 3 +/ which takes place against the background of essential change in the phase composition of crystals. Ions of iron group (Cr, Fe, Co, Ni) in SrTiO/sub 3/ mainly form centres Me/sup 3 +/:(O/sup 2 -/)/sub 6/ with compensation of charge deficit by anion vacancies. Ti/sup 3 +/ ions serve as compensators at non-isovalent substitution for SrTiO/sub 3/:REI/sup 3 +/ (Pr, Nd, Er, Tm). It is shown that the presence of impurity in concentration up to 10/sup -1/ % does not affect the temperature of the phase transformation in the range of 106 K.

  17. Sulfate reduction in freshwater peatlands

    Oequist, M.

    1996-12-31

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO{sub 4}{sup 2-} concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 {mu}M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 {mu}M h{sup -1} while in B and C they were 1 and 0.05 {mu}M h{sup -1}, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 {mu}g d{sup -1} g{sup -1}) were found 10 cm below the water table, in B (ca. 1.0 {mu}g d{sup -1} g{sup -1}) in the vicinity of the water table, and in C (0.75 {mu}g d{sup -1} g{sup -1}) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m{sup -2} d{sup -1}, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m{sup -2} d{sup -1}, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination

  18. Sulfate reduction in freshwater peatlands

    Oequist, M.

    1996-01-01

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO 4 2- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 μM. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 μM h -1 while in B and C they were 1 and 0.05 μM h -1 , respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d -1 g -1 ) were found 10 cm below the water table, in B (ca. 1.0 μg d -1 g -1 ) in the vicinity of the water table, and in C (0.75 μg d -1 g -1 ) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m -2 d -1 , while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m -2 d -1 , respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  19. Magnesium sulfate in femoral nerve block, does postoperative analgesia differ? A comparative study

    Hossam A. ELShamaa

    2014-04-01

    Conclusion: The current study concluded that the admixture of magnesium to bupivacaine provides a profound prolongation of the femoral nerve block, in addition to a significant decrease in postoperative pain scores and total dose of rescue analgesia, with a longer bearable pain periods in the first postoperative day.

  20. Aluminum potassium sulfate and tannic acid sclerotherapy for Goligher Grades II and III hemorrhoids: Results from a multicenter study

    Miyamoto, Hidenori; Hada, Takenori; Ishiyama, Gentaro; Ono, Yoshito; Watanabe, Hideo

    2016-01-01

    AIM: To show that aluminum potassium sulfate and tannic acid (ALTA) sclerotherapy has a high success rate for Grade II and III hemorrhoids. METHODS: This study was based on the clinical data of 604 patients with hemorrhoids who underwent ALTA sclerotherapy between January 2009 and February 2015. The objective of this study was to assess the efficacy of this treatment for Grades II and III hemorrhoids. Preoperative and postoperative symptoms, complications and success rate were all assessed retrospectively. Follow-up consisted of a simple questionnaire, physical examination and an anoscopy. Patients were followed-up at one day, one week, two weeks, one month, one year, two years, three years, four years and five years after the ALTA sclerotherapy. RESULTS: One hundred and sixty-nine patients were diagnosed with Grade II hemorrhoids and 435 patients were diagnosed with Grade III hemorrhoids. The one year, three year and five year cumulative success rates of ALTA sclerotherapy for Grades II and III hemorrhoids were 95.9% and 93.1%; 89.3% and 83.7%; and 89.3% and 78.2%, respectively. No significant differences were observed in the cumulative success rates after ALTA sclerotherapy between Grades II and III hemorrhoids (P = 0.09). There were forty-seven post-operative complications (low grade fever; anal pain; urinary retention; rectal ulcer; and others). No serious or life-threatening complications occurred and all cases improved through conservative treatment. At univariate analysis there were no predictive factors of failure. CONCLUSION: ALTA sclerotherapy has had a high success rate for Grade II and III hemorrhoids during five years of post-operative treatment. However, additional studies are needed to evaluate the efficacy of this ALTA sclerotherapy in the management of hemorrhoidal disease. PMID:27458504

  1. Controlling sulfate attack in Mississippi Department of Transportation structures.

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with specif...

  2. Controlling sulfate attack in Mississippi Department of Transportation structures

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with sp...

  3. Synthesis and anion binding studies of tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors: Proton transfer-induced selectivity for hydrogen sulfate over sulfate.

    Khansari, Maryam Emami; Johnson, Corey R; Basaran, Ismet; Nafis, Aemal; Wang, Jing; Leszczynski, Jerzy; Hossain, Md Alamgir

    2015-01-01

    Tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors, tris([(4-cyanophenyl)amino]propyl)urea ( L1 ) and tris([(4-cyanophenyl)amino]propyl)thiourea ( L2 ), have been synthesized and their anion binding properties have been investigated for halides and oxoanions. As investigated by 1 H NMR titrations, each receptor binds an anion with a 1:1 stoichiometry via hydrogen-bonding interactions (NH⋯anion), showing the binding trend in the order of F - > H 2 PO 4 - > HCO 3 - > HSO 4 - > CH 3 COO - > SO 4 2- > Cl - > Br - > I in DMSO- d 6 . The interactions of the receptors were further studied by 2D NOESY, showing the loss of NOESY contacts of two NH resonances for the complexes of F - , H 2 PO 4 - , HCO 3 - , HSO 4 - or CH 3 COO - due to the strong NH⋯anion interactions. The observed higher binding affinity for HSO 4 - than SO 4 2- is attributed to the proton transfer from HSO 4 - to the central nitrogen of L1 or L2 which was also supported by the DFT calculations, leading to the secondary acid-base interactions. The thiourea receptor L2 has a general trend to show a higher affinity for an anion as compared to the urea receptor L1 for the corresponding anion in DMSO- d 6 . In addition, the compound L2 has been exploited for its extraction properties for fluoride in water using a liquid-liquid extraction technique, and the results indicate that the receptor effectively extracts fluoride from water showing ca. 99% efficiency (based on L2 ).

  4. Arsenic Encapsulation Using Portland Cement With Ferrous Sulfate/Lime And Terra-BondTM Technologies - Microcharacterization And Leaching Studies

    This work reports the results of an investigation on the treatment and encapsulation of arsenic-containing materials by Portland cement with ferrous sulfate and lime (PFL) and Terra-BondTM, a commercially available patented technology. The arsenic materials treated we...

  5. Post-mortem computed tomography angiography utilizing barium sulfate to identify microvascular structures : a preliminary phantom model and case study

    Haakma, Wieke; Rohde, Marianne; Kuster, Lidy; Uhrenholt, Lars; Pedersen, Michael; Boel, Lene Warner Thorup

    2016-01-01

    We investigated the use of computer tomography angiography (CTA) to visualize microvascular structures in a vessel-mimicking phantom and post-mortem (PM) bodies. A contrast agent was used based on 22% barium sulfate, 20% polyethylene glycol and 58% distilled water. A vessel-mimicking phantom

  6. The Effect of Sodium Hyaluronate plus Sodium Chondroitin Sulfate Solution on Peritendinous Adhesion and Tendon Healing: An Experimental Study

    Hacı Bayram Tosun

    2016-06-01

    Full Text Available Background: Adhesion formation following tendon injury is a serious clinical problem. Aims: In this experimental study, the effects of the combination of sodium hyaluronate (HA and chondroitin sulfate (CS on peritendinous adhesion and tendon healing were evaluated. Study Design: Animal experimentation. Methods: Twenty-one mature Sprague Dawley male rats were randomly divided into three equal groups. The rats’ Achilles tendons were cut and repaired with a modified Kessler technique. About 0.25 and 0.50 mL of the HA and CS (HA+CS combination were injected subcutaneously into the repair site of the rats in groups 1 and 2, respectively, on days 0, 3, 7, and 10. The subjects in group 3 were used as the control group. At 6 weeks, all rats were euthanized. The tenotomy site was examined macroscopically in all animal subjects. Four samples were assigned to the histopathological examination group, and the others were assigned to the biomechanical assessment group. Results: Inflammation and adhesion in both treatment groups were observed at a lower rate than in the control group. The collagen filaments in both treatment groups were regular and the number was low when compared to the control group. However, there was no statistically significant difference between group 1 and the control group. The quantity, quality, and grade of the adhesions were statistically significantly lower in group 2 when compared with the other groups. The mean maximum stress strength in group 2 was statistically significantly higher than that in group 1 and the control group. Conclusion: Local administration of the HA+CS combination solution is a valid tool for preventing peritendinous adhesion after extrasynovial tendon repair such as Achilles tendon, and is a treatment option in such cases.

  7. Histopathological and bacterial study of Persian sturgeon fry, Acipenser persicus (Borodin, 1897) exposed to copper sulfate and potassium permanganate.

    Moshtaghi, Batol; Khara, Hossein; Pazhan, Zabiyollah; Shenavar, Alireza

    2016-09-01

    Persian sturgeon frys were exposed to different concentrations of copper sulfate and potassium permanganate in order to the evaluation of their impacts on bacterial load of skin, gill and surrounding water and also the histopathological alternations of gill tissue. For this purpose, the sublethal doses were determined after a pre-test and then the experiment was done in 4 (for copper sulfate: 0.07, 0.14, 026 and 0.5 mg/l) and 5 (for potassium permanganate: 0.07, 0.14, 026, 0.5 and 1 mg/l) treatments with three replicates inside the glass aquaria. Also, one group without disinfecting drug was considered as control for each experiment. The microbial and histopathological investigations were done after 96 h exposure. According to our results, a range of histopathological alternations were observed in gills tissue including mucus coagulation and secretion, hyperplasia, lamellar necrosis, hyperplasia, lamellar adhesion, haemorrhage, thickening of secondary lamellae, hypertrophy of supporter cartilage, clubbing of gill lamellae and sliming of primary lamellae. The severity of these alternations increased with increasing of the doses of the copper sulfate and potassium permanganate. The bacterial load (CFU/g) of gill, skin and surrounding water was lower in 0.07 mg/l copper sulfate treatment and 1 mg/l potassium permanganate treatment (P permanganate have disinfecting effects on bacterial load of gill, skin and surrounding water, although this is along with some histopathological alternations. Also, it seems that the copper sulfate has higher disinfecting power than potassium permanganate.

  8. Acid Sulfate Alteration on Mars

    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

  9. The ceric sulfate dosimeter

    Bjergbakke, Erling

    1970-01-01

    The process employed for the determination of absorbed dose is the reduction of ceric ions to cerous ions in a solution of ceric sulfate and cerous sulfate in 0.8N sulfuric acid: Ce4+→Ce 3+ The absorbed dose is derived from the difference in ceric ion concentration before and after irradiation...

  10. Interactions between poly(acrylic acid) and sodium dodecyl sulfate: isothermal titration calorimetric and surfactant ion-selective electrode studies.

    Wang, C; Tam, K C

    2005-03-24

    Interaction between a monodispersed poly(acrylic acid) (PAA) (M(W) = 5670 g/mol, M(w)/M(n) = 1.02) with sodium dodecyl sulfate (SDS) was investigated using isothermal titration calorimetry (ITC), ion-selective electrode (ISE), and dynamic light scattering measurements. Contrary to previous studies, we report for the first time evidence of interaction between SDS and PAA when the degree of neutralization (alpha) of PAA is lower than 0.2. Hydrocarbon chains of SDS cooperatively bind to apolar segments of PAA driven by hydrophobic interaction. The interaction is both enthalpy and entropy favored (deltaH is negative but deltaS is positive). In 0.05 wt % PAA solution, the SDS concentration corresponding to the onset of binding (i.e., CAC) is approximately 2.4 mM and the saturation concentration (i.e., C(S)) is approximately 13.3 mM when alpha = 0. When PAA was neutralized and ionized, the binding was hindered by the enhanced electrostatic repulsion between negatively charged SDS and PAA chains and improved solubility of the polymer. With increasing alpha to 0.2, CAC increases to approximately 6.2 mM, C(S) drops to 8.6 mM, and the interaction is significantly weakened where the amount of bound SDS on PAA is reduced considerably. The values of CAC and C(S) derived from different techniques are in good agreement. The binding results in the formation of mixed micelles on apolar PAA coils, which then expands and dissociates into single PAA chains. The majority of unneutralized PAA molecules exist as single polymer chains stabilized by bound SDS micelles in solution after the saturation concentration.

  11. X-ray study of surface layers of tungsten monocrystals after electroerosion machining

    Aleshina, S.A.; Baranov, Yu.V.; Smirnov, I.S.; Marchuk, A.I.

    1981-01-01

    The presence of polycrystal surface layer, approximately 10 μm thick in subjacent layers and the presence of highly developed block structure which is the result of high-temperature effect of electroerosion machining are detected. Angles of disorientation between blocks, which constitute tens of angular minutes, are evaluated using the method of X-ray topography. According to broadening of profile of X-ray diffraction lines analysis of fine crystal structure of the surface layers is conducted. It is shown that the broadening of diffraction lines is mainly connected with the presence of coherent scat-- tering regions

  12. Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells

    Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

    2015-01-01

    Recent studies identified PCB sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific...

  13. Experimental Study on the Feasibility of Using Water Glass and Aluminum Sulfate to Treat Complications in High Liquid Limit Soil Subgrade

    Wen-hui Zhang

    2015-01-01

    Full Text Available The feasibility of using water glass and aluminum sulfate to treat high liquid limit soil subgrade diseases is studied through laboratory experiments, and the following results were observed. After improving the high liquid limit clay with water glass and aluminum sulfate, the liquid limit decreases, the plastic limit increases, and the plasticity index decreases. Compared with untreated soil, the clay content of the improved soil decreases, while the silt and coarse contents increase. The absolute and relative expansion rates of the improved soil are both lower than those of the untreated soil. With the same number of dry and wet cycles, the decreased degrees of cohesion and internal friction angle of the improved soil are, respectively, one-half and one-third of those of the untreated soil. After three dry and wet cycles, the California bearing ratio (CBR of the untreated soil does not meet the requirements of specifications. However, after being cured for seven days and being subjected to three dry and wet cycles, the CBR of the improved soil, with 4% water glass solution and 0.4% aluminum sulfate, meets the requirements of specifications.

  14. Study of the solubility of yttrium, praseodymium, neodymium, and gadolinium sulfates in the presence of sodium and potassium in sulfuric-phosphoric acid solutions at 20 deg C

    Lokshin, Eh.P.; Tareeva, O.A.; Kashulina, T.G.

    2007-01-01

    The solubility of yttrium, praseodymium, neodymium, and gadolinium sulfates in the presence of sodium and potassium ions and the composition of solid phases were studied at 20 deg C in relation to the concentration of acids in sulfuric acid, phosphoric acid, and sulfuric-phosphoric acid solutions containing up to 36 wt % H 2 SO 4 and 33.12 g 1 -1 H 3 PO 4 . The formation of double sulfates of praseodymium and neodymium with sodium and potassium ions, as well as of gadolinium sulfate with sodium ions of the composition 1 : 1 was revealed. In water at 20 deg C, the solubility products of PrNa(SO 4 ) 2 ·H 2 O, NdNa(SO 4 ) 2 ·H 2 O, GdNa(SO 4 ) 2 ·H 2 O, PrK(SO 4 ) 2 ·H 2 O, and NdK(SO 4 ) 2 ·H 2 O are found to be 7.28x10 -8 , 7.84x10 -8 , 3.09x10 -6 , 3.02x10 -6 , and 1.70x10 -6 , respectively [ru

  15. Uptake studies with chondrotropic 99mTc-chondroitin sulfate in articular cartilage. Implications for imaging osteoarthritis in the knee

    Sobal, Grazyna; Dorotka, Ronald; Menzel, Johannes; Sinzinger, Helmut

    2013-01-01

    Chondroitin sulfate (CS) is an endogenous component of extracellular matrix in the cartilage and can be valuable for imaging of cartilage degeneration after radiolabeling. Data monitoring the uptake of 99m TcCS by human cartilage are rare. Radiolabeling was performed by 99m TcO 4 − /tin method at pH 5.0 in 0.5 M sodium acetate. For uptake studies human articular cartilage (n = 4, 65–79a) derived from individuals undergoing knee replacement (pieces of 3–5 mg wet weight), or frozen tissue sections (5 μ) for autoradiography (10 μCi) were used. The uptake was monitored from 10 min up to 96 h to achieve saturation. As the commercially available drug Condrosulf (IBSA, Lugano) contains Mg-stearate (0.25%) as additive (to improve its gastrointestinal resorption), we investigated the uptake ± additive. The washout of the tracer was examined by tissue incubation after uptake experiments (3 h and 24 h) with PBS-buffer for 10 min to 3 h. Using human articular cartilage the maximal uptake of 99m TcCS (specific activity of 4.1–6.1 Ci/mmol) was continuously increasing with time amounting to a maximum of 53.2% ± 3.2% with additive, versus 39.4% ± 2.3%, without additive, at saturation. Additive increased the resorption of the drug and consecutively its uptake. The washout of the tracer from cartilage after 3 h uptake amounted to 1.5% ± 0.2% with additive, versus 2.6% ± 0.5%, without. After 24 h washout was lower amounting to 1.1% ± 0.1% versus 1.75% ± 0.15%, respectively. Autoradiography revealed also a continuous increase in uptake of 99m TcCS with time. After 10 min of incubation the uptake increase was proportional to the incubation time, reaching the maximum at 48–72 h. Enhanced uptake at the surface (superficial zone) as compared to the subchondral part (deep zone) of slices, was observed. The non-specific uptake in the presence of 50-fold excess of cold CS was time-dependent up to a maximum of 15% (tissue) and 10% (autoradiography), at saturation. The

  16. Studies on bile acid and bilirubin in liver diseases Part 2. Clinical significance of serum bilirubin sulfate in various liver diseases

    石川, 泰祐

    1980-01-01

    The clinical significance of serum bilirubin sulfate, one of the direct bilirubin, was evaluated in various liver diseases with over 2 mg/dl of serum bilirubin concentration. The diagnosis included 25 cases of acute hepatitis, 8 cases of chronic hepatitis, 8 cases of liver cirrhosis and 16 cases of liver cirrhosis with hepatoma. Bilirubin sulfate was fractioned by Yonei's solvent partition method. The clinical significance of bilirubin sulfate was assessed by comparison of bilirubin sulfate w...

  17. Ferrous Sulfate (Iron)

    ... are allergic to ferrous sulfate, any other medications tartrazine (a yellow dye in some processed foods and ... in, tightly closed, and out of reach of children. Store it at room temperature and away from ...

  18. Holothurian Fucosylated Chondroitin Sulfate

    Vitor H. Pomin

    2014-01-01

    Full Text Available Fucosylated chondroitin sulfate (FucCS is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

  19. DHEA-sulfate test

    ... DHEA sulfate may be due to: Adrenal gland disorders that produce lower than normal amounts of adrenal hormones, including adrenal insufficiency and Addison disease The pituitary gland not producing normal amounts of its hormones ( hypopituitarism ) ...

  20. Two Phase 1, Open‐Label, Mass Balance Studies to Determine the Pharmacokinetics of 14C‐Labeled Isavuconazonium Sulfate in Healthy Male Volunteers

    Kato, Kota; Hale, Christine; Kowalski, Donna; Lademacher, Christopher; Yamazaki, Takao; Akhtar, Shahzad; Desai, Amit

    2017-01-01

    Abstract Isavuconazonium sulfate is the water‐soluble prodrug of the active triazole isavuconazole. Two phase 1 studies were conducted to identify the metabolic profile and mass balance of isavuconazole and BAL8728 (inactive cleavage product). Seven subjects in study 1 (isavuconazole mass balance) received a single oral dose of [cyano‐14C]isavuconazonium sulfate corresponding to 200 mg isavuconazole. Six subjects in study 2 (BAL8728 mass balance) received a single intravenous dose of [pyridinylmethyl‐14C]isavuconazonium sulfate corresponding to 75 mg BAL8728. Pharmacokinetic parameters of radioactivity in whole blood and plasma and of isavuconazole and BAL8728 in plasma were assessed. Radioactivity ratio of blood/plasma, percentage of dose, and cumulative percentage of radioactive dose recovered in urine and feces for isavuconazole and BAL8728 were assessed. Metabolic profiling was carried out by high‐performance liquid chromatography and mass spectrometry. Mean plasma isavuconazole pharmacokinetic parameters included apparent clearance (2.3 ± 0.7 L/h), apparent volume of distribution (301.8 ± 105.7 L), and terminal elimination half‐life (99.9 ± 44.6 hours). In study 1, isavuconazole‐derived radioactivity was recovered approximately equally in urine and feces (46.1% and 45.5%, respectively). In study 2, BAL8728‐derived radioactivity was predominantly recovered in urine (96.0%). Isavuconazole (study 1) and M4 (cleavage metabolite of BAL8728; study 2) were the predominant circulating components of radioactivity in plasma. PMID:28750160

  1. SULT1A3-Mediated Regiospecific 7-O-Sulfation of Flavonoids in Caco-2 Cells Can Be Explained by the Relevant Molecular Docking Studies

    Meng, Shengnan; Wu, Baojian; Singh, Rashim; Yin, Taijun; Morrow, John Kenneth; Zhang, Shuxing; Hu, Ming

    2012-01-01

    Flavonoids are the polyphenolic compounds with various claimed health benefits, but the extensive metabolism by uridine-5'-diphospho-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) in liver and intestine led to poor oral bioavailabilities. The effects of structural changes on the sulfonation of flavonoids have not been systemically determined, although relevant effects of structural changes on the glucuronidation of flavonoids had. We performed the regiospecific sulfonation of sixteen flavonoids from five different subclasses of flavonoids, which are represented by apigenin (flavone), genistein (isoflavone), naringenin (flavanone), kaempherol (flavonol), and phloretin (chalcone). Additional studies were performed using 4 mono-hydroxyl flavonoids with –OH group at 3, 4’, 5 or 7 position, followed by 5 di-hydroxyl-flavonoids, and 2 tri-hydroxyl flavonoids by using expressed human SULT1A3 and Caco-2 cell lysates. We found that these compounds were exclusively sulfated at the 7-OH position by SULT1A3 and primarily sulfated at 7-OH position in Caco-2 cell lysates with minor amounts of 4’-O-sulfates formed as well. Sulfonation rates measured using SULT1A3 and Caco-2 cell lysates were highly correlated at substrate concentrations of 2.5 and 10 µM. Molecular docking studies provided structural explanations as to why sulfonation only occurred at the 7-OH position of flavones, flavonols and flavanones. In conclusion, molecular docking studies explain why SULT1A3 exclusively mediates sulfonation at the 7-OH position of flavones/flavonols, and correlation studies indicate that SULT1A3 is the main isoform responsible for flavonoid sulfonation in the Caco-2 cells. PMID:22352375

  2. Investigation of diamond wheel topography in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire using fractal analysis method.

    Wang, Qiuyan; Zhao, Wenxiang; Liang, Zhiqiang; Wang, Xibin; Zhou, Tianfeng; Wu, Yongbo; Jiao, Li

    2018-03-01

    The wear behaviors of grinding wheel have significant influence on the work-surface topography. However, a comprehensive and quantitative method is lacking for evaluating the wear conditions of grinding wheel. In this paper, a fractal analysis method is used to investigate the wear behavior of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire, and a series of experiments on EUAG and conventional grinding (CG) are performed. The results show that the fractal dimension of grinding wheel topography is highly correlated to the wear behavior, i.e., grain fracture, grain pullout, and wheel loading. An increase in cutting edge density on the wheel surface results in an increase of the fractal dimension, but an increase in the grain pullout and wheel loading results in a decrease in the fractal dimension. The wheel topography in EUAG has a higher fractal dimension than that in CG before 60 passes due to better self-sharpening behavior, and then has a smaller fractal dimension because of more serious wheel loadings after 60 passes. By angle-dependent distribution analysis of profile fractal dimensions, the wheel surface topography is transformed from isotropic to anisotropic. These indicated that the fractal analysis method could be further used in monitoring of a grinding wheel performance in EUAG. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Measuring fission lifetimes with the crystal-blocking technique in mono-crystal, access to nuclear dissipation

    Basnary, St.

    2002-10-01

    Energy dissipation in nuclear matter may play an important role in the determination of the way through which heavy nuclei des-excite: fission or particle evaporation. An important dissipation should imply longer interval of time during which the nucleus is deformed. In that way the measurement of fission lifetimes may shed light on energy dissipation, but these measurements are very delicate to perform. Most available data on deformation times come from indirect measurements combined with the use of more or less valid models. The crystal-blocking lifetime technique in mono-crystals allows the direct measurement of long fission lifetimes. This technique has been applied to different nuclei situated in the proximity of lead. We have obtained relatively high values: τ > 3.10 -19 s for both lead and uranium which implies a strong dissipation of energy. The computation of dissipation coefficients has led to the following values: β ≅ 2.10 21 /s for lead and β ≥ 6.10 21 /s for uranium (E * > 120 MeV). These results show that dissipation effects have to be taken into account in the determination of the deexcitation way. (A.C.)

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

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

    2013-01-01

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

  5. Studies of structure change of iron sulfates and its catalysis; Ryusantetsukei shokubai no kozo henka to sono shokubai sayo

    Ogata, E.; Horie, K. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Nishijima, A. [National Institute of Materials and Chemical Research, Tsukuba (Japan)

    1996-10-28

    Since a huge amount of coal containing inorganic ash is treated for the commercial hydroliquefaction process, cheap catalysts widely distributing on the earth with large reserves are desired rather than expensive catalysts. This paper describes the effects of addition of sulfur on the catalysis of iron sulfates during the hydroconversion of 1-methylnaphthalene (1-MN). Reactions of 1-MN were conducted at the same charging amount of iron in the reaction system. Sulfur was directly added in the reaction system using ferrous sulfate (FeSO4) as precursor. Consequently, it was found that FeSO4 provides lower but similar catalytic activity to the synthetic pyrite catalyst prepared through the complex processes with the precise control. Thus, it was revealed that high performance pyrrhotite (Fe(1-x)S) catalyst can be prepared for the hydrogenation of aromatic-rings by adding solid sulfur into the reaction system using commercial reagent, FeSO4 as a precursor of the catalyst. 9 figs.

  6. A thermodynamic and kinetic study of trace iron removal from aqueous cobalt sulfate solutions using Monophos resin.

    Wang, Guangxin; Zhao, Yunchao; Yang, Bin; Song, Yongfa

    2018-01-01

    High purity cobalt has many important applications, such as magnetic recording media, magnetic recording heads, optoelectronic devices, magnetic sensors, and integrated circuits, etc. To produce 5N or higher purity cobalt in an electro-refining process, one of the challenges is to effectively reduce the Fe content of aqueous cobalt salt solution before electrolysis. This paper describes thermodynamic and kinetic investigations of the Fe adsorption process of a new sulfonated monophosphonic resin with the trade mark Monophos. Five cobalt sulfate solutions of different Co concentrations were prepared. Fe ions were removed from the solutions by ion exchange method using Monophos resin. Chemical analysis was carried out using a Perkin Elmer ICP-OES. The initial Fe concentrations of about 0.9-2.0 mg/L can be reduced to about 0.3-0.8 mg/L, which is equivalent to an Fe removal rate of 60-67%. The Langmuir isothermal adsorption model applies well to the Fe removal process. A second-order type based on McKay equation fits better with experimental data than other kinetic models. The kinetic curve can be divided into two sections. For t 30 min. Monophos resin is effective for the removal of trace Fe from cobalt sulfate solution. This ion exchange process obeys the Langmuir isothermal adsorption model and the McKay equation of second-order kinetics.

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

    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.

  8. Sulfate reduction and methanogenesis at a freshwater

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    The freshwater-seawater interface was studied in a ~9-m thick anaerobic aquifer located in marine sand and gravel with thin peat lenses. Very limited amounts of iron-oxides are present. Consequently, the dominating redox processes are sulfate reduction and methanogenesis, and the groundwater...... is enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...... chemistry was studied in a 120 m transect perpendicular to the coast. Cores were taken for radiotracer rate measurements of sulfate reduction and methanogenesis. In the saline part of the aquifer 35 m inland, sulfate reduction was the dominant process with rates of 0.1-10 mM/year. In the freshwater part 100...

  9. DEPENDENCY OF SULFATE SOLUBILITY ON MELT COMPOSITION AND MELT POLYMERIZATION

    JANTZEN, CAROL M.

    2004-01-01

    Sulfate and sulfate salts are not very soluble in borosilicate waste glass. When sulfate is present in excess it can form water soluble secondary phases and/or a molten salt layer (gall) on the melt pool surface which is purported to cause steam explosions in slurry fed melters. Therefore, sulfate can impact glass durability while formation of a molten salt layer on the melt pool can impact processing. Sulfate solubility has been shown to be compositionally dependent in various studies, (e.g. , B2O3, Li2O, CaO, MgO, Na2O, and Fe2O3 were shown to increase sulfate solubility while Al2O3 and SiO2 decreased sulfate solubility). This compositional dependency is shown to be related to the calculated melt viscosity at various temperatures and hence the melt polymerization

  10. Heritability and clinical determinants of serum indoxyl sulfate and p-cresyl sulfate, candidate biomarkers of the human microbiome enterotype.

    Liesbeth Viaene

    Full Text Available BACKGROUND: Indoxyl sulfate and p-cresyl sulfate are unique microbial co-metabolites. Both co-metabolites have been involved in the pathogenesis of accelerated cardiovascular disease and renal disease progression. Available evidence suggests that indoxyl sulfate and p-cresyl sulfate may be considered candidate biomarkers of the human enterotype and may help to explain the link between diet and cardiovascular disease burden. OBJECTIVE AND DESIGN: Information on clinical determinants and heritability of indoxyl sulfate and p-cresyl sulfate serum is non-existing. To clarify this issue, the authors determined serum levels of indoxyl sulfate and p-cresyl sulfate in 773 individuals, recruited in the frame of the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO study. RESULTS: Serum levels of indoxyl sulfate and p-cresyl sulfate amounted to 3.1 (2.4-4.3 and 13.0 (7.4-21.5 μM, respectively. Regression analysis identified renal function, age and sex as independent determinants of both co-metabolites. Both serum indoxyl sulfate (h2 = 0.17 and p-cresyl sulfate (h2 = 0.18 concentrations showed moderate but significant heritability after adjustment for covariables, with significant genetic and environmental correlations for both co-metabolites. LIMITATIONS: Family studies cannot provide conclusive evidence for a genetic contribution, as confounding by shared environmental effects can never be excluded. CONCLUSIONS: The heritability of indoxyl sulfate and p-cresyl sulfate is moderate. Besides genetic host factors and environmental factors, also renal function, sex and age influence the serum levels of these co-metabolites.

  11. p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

    Hye Sun Hyun

    2013-04-01

    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

  12. 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

    Dillon, Jesse G; Fishbain, Susan; Miller, Scott R

    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....

  13. Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65

    Diaz S, A.; Gonzalez F, E.; Arganis J, C.; Luna C, P.; Carapia M, L.

    2004-01-01

    In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

  14. Effect of metakaolin on external sulfate attack

    Ramlochan, T.; Thomas, M. [Toronto Univ., Dept. of Civil Engineering, ON (Canada)

    2000-07-01

    The effect of high reactivity metakaolin (HRM) on the sulfate resistance of mortars was studied. Mortar bars with three cements of varying C{sub 3}A content were used for the experiment. After a six month exposure to a 5 per cent solution of sodium sulfate, mortar bars incorporating any level of HRM as a partial replacement for a high-C{sub 3}A was considered 'moderately sulfate resistant'; mortar bars with HRM and a moderate or low C{sub 3}A content as 'high sulfate resistant'. It was also determined that for long term sulfate resistance 15 per cent HRM or more may be required, depending on the C{sub 3}A content. The performance of HRM was found to be significantly influenced by the water-cementitious material ratio, and in turn, by permeability, suggesting that HRM might increase sulfate resistance more by lowering the permeability of the concrete than by any chemical action. 7 refs., 4 tabs., 7 figs.

  15. Modeling the use of sulfate additives for potassium chloride destruction in biomass combustion

    Wu, Hao; Grell, Morten Nedergaard; Jespersen, Jacob Boll

    2013-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4. In the present study, the decomposition of ammonium sulfate, aluminum sulfate and ferric sulfate...... of ammonium sulfate addition and ferric sulfation addition compared favorably with the experimental results. However, the model for aluminum sulfate addition under-predicted significantly the high sulfation degree of KCl observed in the experiments, possibly because of an under-estimation of the decomposition...... rate of aluminum. Under the boiler conditions of the present work, the simulation results suggested that the desirable temperature for the ferric sulfate injection was around 950-900oC, whereas for ammonium sulfate the preferable injection temperature was below 800oC....

  16. Modeling the Use of Sulfate Additives for Potassium Chloride Destruction in Biomass Combustion

    Wu, Hao; Pedersen, Morten Nedergaard; Jespersen, Jacob Boll

    2014-01-01

    Potassium chloride, KCl, formed from biomass combustion may lead to ash deposition and corrosion problems in boilers. Sulfates are effective additives for converting KCl to the less harmful K2SO4 and HCl. In the present study, the rate constants for decomposition of ammonium sulfate and aluminum...... sulfate were obtained from experiments in a fast heating rate thermogravimetric analyzer. The yields of SO2 and SO3 from the decomposition were investigated in a tube reactor at 600–900 °C, revealing a constant distribution of about 15% SO2 and 85% SO3 from aluminum sulfate decomposition and a temperature...... fluidized-bed reactor using ammonium sulfate, aluminum sulfate, and ferric sulfate as additives. The simulation results for ammonium sulfate and ferric sulfate addition compared favorably to the experiments. The predictions for aluminum sulfate addition were only partly in agreement with the experimental...

  17. About the singular behavior of the ionic condensation of sodium chondroitin sulfate: Conductivity study in water and water dioxane mixture

    M'halla, Jalel; Besbes, Rafik; Bouazzi, Ramzi; Boughammoura, Sondes

    2006-01-01

    In this work, we generalized the (Bjerrum-Debye-Fuoss-MSA) double layer model to an ellipsoidal polyion (chondroitin sulfate) of (∣ Zs∣ e) structural charge, Ls structural length, R minor axe and ( R2 + L2/4) 1/2 major axe. With L ⩽ Ls. Na + counter ions are distributed on the contact (or condensed) layer and on the Debye layer (ionic atmosphere). Both layers are ellipsoidal equipotentials of, respectively, R and d minor axes and are concentric to the polyion. With d = ( R + 1/2 Γ), Γ is the Debye-MSA screen parameter. The equilibrium distribution of Na + ions is derived from a "two states" statistical approach, leading to a general implicit expression for the rate of condensation (1 - α). The generality of this formula results from the fact that it takes into account the finite size of the polyion ( L ≠ ∞ and R ≠ 0) and allows to calculate α for different conformations of the polyion: (ellipsoidal L ≠ 0, cylindrical: L = Ls, spherical: L → 0, and Manning's model: RL-1 → 0). The main conclusion of this model is that, α obeys to the Ostwald's principle of dilution ( α → 1 when CNa+ → 0). This result is contrary to Manning's theory, for which α is a constant αM independent on the concentration Ci: αM = bS/(∣ Zi∣ Lb), with bS = Ls/∣ Zs∣ and Lb = e2/( ɛkT) is the Bjerrum length. However, our analysis shows that the rate of variation: (∂ α/∂ Ci) in a given range of concentration, depends on the structural parameter bS. Indeed, the critical Manning condition ( α-1αM = 1, ⇒(∂ α/∂ Ci) ≈ 0), is compatible with the general following "rod-like model" approximation: (1-α)≈|Zi|(πbS)[4πZi2Lb][αCiR2];withbS″=αM-1 only for some peculiar values of bS and Lb (i.e., dielectric constant: ɛ). In water at 25 °C ( ɛ = 78.3), this singular behavior occurs for a range of a relative low or moderate concentration for some polyelectrolytes of bS structural parameter of about 5.8 Å. This is the case of sodium chondroitin

  18. Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

    Sun, Wenjie; Barlaz, Morton A

    2015-02-01

    A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

    Dallam, R.D.

    1987-01-01

    Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H 2 35 SO 4 ) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables

  20. Role of an ionic liquid, 1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)ethyl sulfate in extraction studies of gadolinium oxide

    Sen, Kamalika [Calcutta Univ., Kolkata (India). Dept. of Chemistry; Wolterbeek, H.T. [Technical Univ. Delft (NL). Section RIH (Radiation and Isotopes in Health)

    2012-07-01

    The room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)ethyl sulfate was studied for its extraction behavior for {sup 159}Gd in an environmentally benign liquid-liquid extraction system. The gadolinium oxide when dissolved in nitric acid and extracted in an RTIL/dextran biphasic system, was found to get completely extracted in the IL phase. The otherwise difficult to dissolve gadolinium oxide was found to have some solubility in the IL studied. Biphasic systems consisting of IL/dextran and certain IL/salt were studied for the extraction behavior of Gd{sub 2}O{sub 3} dissolved in the above RTIL. A similar experiment was also done with acid-dissolved gadolinium oxide for comparison. (orig.)

  1. The study of calcium sulfate decomposition by experiments under O{sub 2}/CO{sub 2} atmosphere

    Liu, Y. [HangZhou Dianzi Univ. (China). School of Science; Zhou, H.; Cen, K.F. [State Key Laboratory of Clean Energy Utilization, HangZhou (China); Liu, Y.H.; Stanger, R.; Elliot, L.; Wall, T. [Newcastle Univ. (Australia). Chemical Engineering

    2013-07-01

    Sulphur emission and the effect on ash properties and boiler- tube corrosion in oxy-fuel combustion have received increasing attention in the recent years. Early investigation about calcium- based desulphurization in oxy-fuel, addressed the advantage to reduce the SO{sub 2} emission. This paper, the decomposition of calcium sulphate was characterized by thermogravimetric analyzer. The results showed that the decomposition inhibited by increasing O{sub 2} concentration and SO{sub 2} concentration resulted from recycled flue gas. And CO{sub 2} concentration had the negative effect, which can be solved by changing O{sub 2} concentration through appropriately adjusting recycled flue gas ratio. The kinetics mechanism of calcium sulfate-decomposition in oxy-fuel combustion was further analyzed. Compared with conventional atmosphere, the reaction activation energy was heightened in oxy-fuel conditions, and the difference increased with rising temperature. So it can further confirm the advantage of calcium utilization rate under high temperature in oxy-fuel condition.

  2. Experimental Results for Direct Electron Irradiation of a Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, Thad [Argonne National Lab. (ANL), Argonne, IL (United States); Sun, Zaijing [Argonne National Lab. (ANL), Argonne, IL (United States); Wardle, Kent E. [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-30

    In support of the development of accelerator-driven production of fission product Mo-99 as proposed by SHINE Medical Technologies, a 35 MeV electron linac was used to irradiate depleted-uranium (DU) uranyl sulfate dissolved in pH 1 sulfuric acid at average power densities of 6 kW, 12 kW, and 15 kW. During these irradiations, gas bubbles were generated in the solution due to the radiolytic decomposition of water molecules in the solution. Multiple video cameras were used to record the behavior of bubble generation and transport in the solution. Seven six-channel thermocouples were used to record temperature gradients in the solution from self-heating. Measurements of hydrogen and oxygen concentrations in a helium sweep gas were recorded by a gas chromatograph to estimate production rates during irradiation. These data are being used to validate a computational fluid dynamics (CFD) model of the experiment that includes multiphase flow and a custom bubble injection model for the solution region.

  3. Experimental Results for Direct Electron Irradiation of a Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    Chemerisov, Sergey; Gromov, R.; Makarashvili, Vakhtang; Heltemes, Thad; Sun, Zaijing; Wardle, Kent E.; Bailey, James; Stepinski, Dominique; Jerden, James; Vandegrift, George F.

    2015-01-01

    In support of the development of accelerator-driven production of fission product Mo-99 as proposed by SHINE Medical Technologies, a 35 MeV electron linac was used to irradiate depleted-uranium (DU) uranyl sulfate dissolved in pH 1 sulfuric acid at average power densities of 6 kW, 12 kW, and 15 kW. During these irradiations, gas bubbles were generated in the solution due to the radiolytic decomposition of water molecules in the solution. Multiple video cameras were used to record the behavior of bubble generation and transport in the solution. Seven six-channel thermocouples were used to record temperature gradients in the solution from self-heating. Measurements of hydrogen and oxygen concentrations in a helium sweep gas were recorded by a gas chromatograph to estimate production rates during irradiation. These data are being used to validate a computational fluid dynamics (CFD) model of the experiment that includes multiphase flow and a custom bubble injection model for the solution region.

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

    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.

  5. A genetic study of dehydroepiandrosterone sulfate measured before and after a 20-week endurance exercise training program: the HERITAGE Family Study.

    An, P; Rice, T; Gagnon, J; Hong, Y; Leon, A S; Skinner, J S; Wilmore, J H; Bouchard, C; Rao, D C

    2000-03-01

    Familial aggregation and possible major gene effects were evaluated for the baseline serum dehydroepiandrosterone sulfate (DHEAS) level and the change in DHEAS in response to a 20-week exercise training program in a sample of 481 individuals from 99 Caucasian families who were sedentary at baseline and who participated in the HERITAGE Family Study. Baseline DHEAS levels were not normally distributed, and were therefore logarithmically transformed and adjusted for the effects of age and sex prior to genetic analysis. The DHEAS response to training was computed as the simple difference, post-training minus baseline, and was adjusted for the baseline DHEAS level, age, and sex. Maximal (genetic and familial environmental) heritabilities (using a familial correlation model) reached 58% and 30% for the baseline and the response to training, respectively. Our estimate for the baseline is generally in agreement with previous reports, suggesting that the magnitude of the familial effect underlying this phenotype in these sedentary families is similar to that in the general population. However, segregation analysis showed no evidence for a multifactorial familial component in data for either the baseline or the response to training. Rather, a major additive gene controlling the baseline was found. For the response to training in the complete sample, transmission of the major effect from parents to offspring was ambiguous, but in a subset of 56 "responsive" families (with at least 1 family member whose response to training was greater than 1 standard deviation) this major effect was Mendelian in nature. The putative major genes accounted for 50% and 33% of the variance for the baseline and the response to training, respectively. The novel finding in this study is that the baseline DHEAS level and the change in DHEAS in response to training may be influenced by major gene effects.

  6. Anisotropy of superconducting transformation in magnetic fields in Nd sub 1 sub . sub 8 sub 5 Ce sub 0 sub . sub 1 sub 5 CuO sub 4 monocrystal

    Panova, G K; Chernoplekov, N A; Emelchenko, G A; Malyuk, A N; Lin, S T

    2002-01-01

    The anisotropy of the superconducting properties of the Nd sub 1 sub . sub 8 sub 5 Ce sub 0 sub . sub 1 sub 5 CuO sub 4 monocrystal is studied by resistance within the temperature range of 2-30 K in the 0, 1, 2, 4, 6 Tl magnetic fields in the a-b plane. The T sub c (H) and H sub c sub 2 (T) strong anisotropy was observed by the magnetic field different orientation in the a-b plane. The zero direction in the gap of the order parameter is determined. The analysis of the experimental data shows, that such a result may be related to the change in the symmetry in the copper atoms surrounding, leading to its reduction from the tetragonal to orthorhombic one in the low-temperature area. The comparison with the La sub 1 sub . sub 8 sub 5 Sr sub 0 sub . sub 1 sub 5 CuO sub 4 gives all grounds to suppose, that the superconductivity mechanism in the electron- and hole-doped superconductor is similar and the observed difference is connected with the structure peculiarities

  7. Oxygen isotopic fractionation during bacterial sulfate reduction

    Balci, N.; Turchyn, A. V.; Lyons, T.; Bruchert, V.; Schrag, D. P.; Wall, J.

    2006-12-01

    Sulfur isotope fractionation during bacterial sulfate reduction (BSR) is understood to depend on a variety of environmental parameters, such as sulfate concentration, temperature, cell specific sulfate reduction rates, and the carbon substrate. What controls oxygen isotope fractionation during BSR is less well understood. Some studies have suggested that carbon substrate is important, whereas others concluded that there is a stoichiometric relationship between the fractionations of sulfur and oxygen during BSR. Studies of oxygen fractionation are complicated by isotopic equilibration between sulfur intermediates, particularly sulfite, and water. This process can modify the isotopic composition of the extracellular sulfate pool (δ18OSO4 ). Given this, the challenge is to distinguish between this isotopic equilibration and fractionations linked to the kinetic effects of the intercellular enzymes and the incorporation of sulfate into the bacterial cell. The δ18OSO4 , in concert with the sulfur isotope composition of sulfate (δ34SSO4), could be a powerful tool for understanding the pathways and environmental controls of BSR in natural systems. We will present δ18OSO4 data measured from batch culture growth of 14 different species of sulfate reducing bacteria for which sulfur isotope data were previously published. A general observation is that δ18OSO4 shows little isotopic change (kinetic effect during BSR and/or equilibration between sulfur intermediates and the isotopically light water (~-5‰) of the growth medium. Our present batch culture data do not allow us to convincingly isolate the magnitude and the controlling parameters of the kinetic isotope effect for oxygen. However, ongoing growth of mutant bacteria missing enzymes critical in the different steps of BSR may assist in this mission.

  8. Sulfated oligosaccharide structures, as determined by NMR techniques

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Cerezo, A.S.

    1997-01-01

    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a λ-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author)

  9. Do differences in future sulfate emission pathways matter for near-term climate? A case study for the Asian monsoon

    Bartlett, Rachel E.; Bollasina, Massimo A.; Booth, Ben B. B.; Dunstone, Nick J.; Marenco, Franco; Messori, Gabriele; Bernie, Dan J.

    2018-03-01

    Anthropogenic aerosols could dominate over greenhouse gases in driving near-term hydroclimate change, especially in regions with high present-day aerosol loading such as Asia. Uncertainties in near-future aerosol emissions represent a potentially large, yet unexplored, source of ambiguity in climate projections for the coming decades. We investigated the near-term sensitivity of the Asian summer monsoon to aerosols by means of transient modelling experiments using HadGEM2-ES under two existing climate change mitigation scenarios selected to have similar greenhouse gas forcing, but to span a wide range of plausible global sulfur dioxide emissions. Increased sulfate aerosols, predominantly from East Asian sources, lead to large regional dimming through aerosol-radiation and aerosol-cloud interactions. This results in surface cooling and anomalous anticyclonic flow over land, while abating the western Pacific subtropical high. The East Asian monsoon circulation weakens and precipitation stagnates over Indochina, resembling the observed southern-flood-northern-drought pattern over China. Large-scale circulation adjustments drive suppression of the South Asian monsoon and a westward extension of the Maritime Continent convective region. Remote impacts across the Northern Hemisphere are also generated, including a northwestward shift of West African monsoon rainfall induced by the westward displacement of the Indian Ocean Walker cell, and temperature anomalies in northern midlatitudes linked to propagation of Rossby waves from East Asia. These results indicate that aerosol emissions are a key source of uncertainty in near-term projection of regional and global climate; a careful examination of the uncertainties associated with aerosol pathways in future climate assessments must be highly prioritised.

  10. Dissolution of sulfate scales

    Hen, J.

    1991-11-26

    This patent describes a composition for the removal of sulfate scale from surfaces. It comprises: an aqueous solution of about 0.1 to 1.0 molar concentration of an aminopolycarboxylic acid (APCA) containing 1 to 4 amino groups or a salt thereof, and about 0.1 to 1.0 molar concentration of a second component which is diethylenetriaminepenta (methylenephosphonic acid) (DTPMP) or a salt thereof, or aminotri (methylenephosphonic acid) (ATMP) or a salt thereof as an internal phase enveloped by a hydrocarbon membrane phase which is itself emulsified in an external aqueous phase, the hydrocarbon membrane phase continuing a complexing agent weaker for the cations of the sulfate scale than the APCA and DTPMP or ATMP, any complexing agent for the cations in the external aqueous phase being weaker than that in the hydrocarbon membrane phase.

  11. Conductometric study of sodium dodecyl sulfate - nonionic surfactant (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 mixed micelles in aqueous solution

    Ćirin Dejan M.

    2012-01-01

    Full Text Available The present study is concerned with the determination of the critical micelle concentration (cmc of mixed micelles of sodium dodecyl sulfate with one of five nonionic surfactants (Triton X-100, Tween 20, Tween 60, Tween 80 or Tween 85 from conductance measurements. Based on the calculated values of the β parameters we have noticed that SDS-nonionic surfactants mostly showed strong synergistic effect. It was found that nonionic surfactants with mainly longer and more hydrophobic tail show stronger interactions with hydrophobic part of SDS, thus expressing stronger synergism. In SDS-Tween 80 binary system the strongest synergistic effect was noticed. SDS-Tween 85 micellar system showed antagonistic effect, most probably because the presence of the double bond in its three hydrophobic tails (three C18 tails makes it sterically rigid.

  12. Optimal thickness of a monocrystal line object in atomic plane visualization on its image in a high-resolution electron microscope

    Grishina, T.A.; Sviridova, V.Yu.

    1983-01-01

    Theoretical and experimental investigation of the influence of the FCC-lattice crystal (gold, nickel) thickness on conditions of visulization of atomic plane projections (APP) on the crystal image in a transmission high-resolution electron microscope (THREM) is reported. Results of electron diffraction theory are used for theoretical investigation. Calculation analysis of the influence of the monocrystal thickness and orientation on conitions of visualization of APP and atomic columns in monocrystal images formed in THREM in multibeam regimes with inclined and axial illumination is conducted. It is shown that, to visualize the atomic column projections in a crystal image formed in the multibeam regime with axial illumination, optimal are the thicknesses from 0.1 xisub(min) to 0.25 xisub(min) and at some object orientations also the thicknesses from 0.8 xisub(min) to 0.9 xisub(min), where xisub(min) is the extinction length minimum for the given orientation. It is shown that, to realize the ultimate resolutions in multibeam regimes both with inclined and axial illumination the optimal thickness of the object is 0.63 xisub(min). Satisfactory coincidence of theoretical and experimental data is obtained

  13. Radioimmunoassay of dehydroepiandrosterone sulfate

    Vieira, J.G.H.; Furlanetto, R.P.; Russo, E.M.K.; Noguti, K.O.; Chacra, A.R.

    1980-01-01

    The development of a radioimmunological method for the measurement of dehydroepiandrosterone sulfate in serum is described. For the immunization of rabbits, a DHA-3-hemissuccinate-bovine serum albumin conjugate was synthetized and a highly specific anti-serum was produced. The method developed requires only simple dilution prior to assay and the normal values for the different age groups were determined in 146 normal individuals. (Author) [pt

  14. Immobilization of calcium sulfate contained in demolition waste

    Ambroise, J.; Pera, J.

    2008-01-01

    This paper presents the results of a laboratory study undertaken to examine the treatment of demolition waste containing calcium sulfate by means of calcium sulfoaluminate clinker (CSA). The quantity of CSA necessary to entirely consume calcium sulfate was determined. Using infrared spectrometry analysis and X-ray diffraction, it was shown that calcium sulfate was entirely consumed when the ratio between CSA and calcium sulfate was 4. Standard sand was polluted by 4% calcium sulfate. Two solutions were investigated: ·either global treatment of sand by CSA, ·or immobilization of calcium sulfate by CSA, followed by the introduction of this milled mixture in standard sand. Regardless of the type of treatment, swelling was almost stabilized after 28 days of immersion in water

  15. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

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

    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

  17. Potential of nitrate addition to control the activity of sulfate-reducing prokaryotes in high-temperature oil production systems - a comparative study on a nitrate-treated and an untreated system

    Gittel, Antje; Sørensen, Ketil; Skovhus, Torben L.

    Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. Adding nitrate to the injection water is applied to control SRP activity by favoring the growth of heterotrophic, nitrate-reducing bacteria (h......NRB) and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). Microbial diversity, abundance of Bacteria, Archaea and sulfate-reducing prokaryotes (SRP) and the potential activity of SRP were studied in production water samples from a nitrate-treated and an untreated system. The reservoirs and the produced water......) and Desulfotomaculum (system with nitrate). In samples from the untreated site, the presence of active SRP was supported by demonstrating their activity (incubations with 35S-sulfate) and growth in batch cultures at pipeline temperature. No SRP activity was detected at reservoir temperature and in samples from...

  18. Vincristine sulfate loaded dextran microspheres amalgamated with thermosensitive gel offered sustained release and enhanced cytotoxicity in THP-1, human leukemia cells: In vitro and in vivo study.

    Thakur, Vivek; Kush, Preeti; Pandey, Ravi Shankar; Jain, Upendra Kumar; Chandra, Ramesh; Madan, Jitender

    2016-04-01

    Vincristine sulfate (VCS) is a drug of choice for the treatment of childhood and adult acute lymphocytic leukemia, Hodgkin's, non-Hodgkin's lymphoma as well as solid tumors including sarcomas. However, poor biopharmaceutical and pharmacokinetic traits of VCS like short serum half-life (12 min), high dosing frequency (1.4 mg/m(2) per week for 4 weeks) and extensive protein binding (75%) limit the clinical potential of VCS in cancer therapy. In present investigation, injectable vincristine sulfate loaded dextran microspheres (VCS-Dextran-MSs) were prepared and amalgamated with chitosan-β-glycerophosphate gel (VCS-Dextran-MSs-Gel) to surmount the biopharmaceutical and pharmacokinetic limitations of VCS that consequently induced synergistic sustained release pattern of the drug. Particle size and zeta-potential of VCS-Dextran-MSs were measured to be 6.8 ± 2.4 μm and -18.3 ± 0.11 mV along with the encapsulation efficiency of about 60.4 ± 4.5%. Furthermore, VCS-Dextran-MSs and VCS-Dextran-MSs-Gel exhibited slow release pattern and 94.7% and 95.8% of the drug was released in 72 h and 720 h, respectively. Results from cell viability assay and pharmacokinetic as well as histopathological analysis in mice indicated that VCS-Dextran-MSs-Gel offers superior therapeutic potential and higher AUClast than VCS-Dextran-MSs and drug solution. In conclusion, VCS-Dextran-MSs-Gel warrants further preclinical tumor growth study to scale up the technology. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    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.

  20. Preparation of naphtalene monocrystals for scintillometers; Preparacion de monocristales de naftaleno para contadores de centelleo

    Gaeta, R

    1959-07-01

    A method to prepare naphthalene crystals for scintillometers is described. The different methods of preparation and the reasons to choose the Bridgman method are analysed. The thermal curves of the growing furnaces, blister shape, use of curved capillaries and the most convenient growing velocities are studied in detail. Methods of preparation of high purity naphthalene by means of chromatography and zone melting are described. Finally the operations of cutting and polishing of crystal and their most significant physics properties are studied. (Author) 28 refs.

  1. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Pal'-Val', P.P.; Kaufmann, Kh.-J.

    1983-01-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon 0 approximately 10 -4 , during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples

  2. Characterization of lithium niobate monocrystals doped with iron (Li Nb O3:Fe)

    Mastelaro, V.R.; Terrile, N.C.; Nascimento, O.R.; Nicolo, I.

    1988-01-01

    LiNbO 3 :Fe Crystals were analised using EPR Optical absorption spectroscopy and holographic techniques. The site occupied by Fe 3+ is discused and the effect of thermal treatments on Fe 2+ and OH - concentration is studied. The high diffraction efficiency, measure by holographic techniques shows that crystals are particularly good for holographic applications. (author) [pt

  3. Nonlinear optical and microscopic analysis of Cu2+ doped zinc thiourea chloride (ZTC) monocrystal

    Ramteke, S. P.; Anis, Mohd; Pandian, M. S.; Kalainathan, S.; Baig, M. I.; Ramasamy, P.; Muley, G. G.

    2018-02-01

    Organometallic crystals offer considerable nonlinear response therefore, present article focuses on bulk growth and investigation of Cu2+ ion doped zinc thiourea chloride (ZTC) crystal to explore its technological impetus for laser assisted nonlinear optical (NLO) device applications. The Cu2+ ion doped ZTC bulk single crystal of dimension 03 × 2.4 × 0.4 cm3 has been grown from pH controlled aqueous solution by employing slow solvent evaporation technique. The structural analysis has been performed by means of single crystal X-ray diffraction technique. The doping of Cu2+ ion in ZTC crystal matrix has been confirmed by means of energy dispersive spectroscopic (EDS) technique. The origin of nonlinear optical properties in Cu2+ ion doped ZTC crystal has been studied by employing the Kurtz-Perry test and Z-scan analysis. The remarkable enhancement in second harmonic generation (SHG) efficiency of Cu2+ ion doped ZTC crystal with reference to ZTC crystal has been determined. The He-Ne laser assisted Z-scan analysis has been performed to determine the third order nonlinear optical (TONLO) nature of grown crystal. The TONLO parameters such as susceptibility, absorption coefficient, refractive index and figure of merit of Cu-ZTC crystal have been evaluated using the Z-scan transmittance data. The laser damage threshold of grown crystal to high intensity of Nd:YAG laser is found to be 706.2 MW/cm2. The hardness number, work hardening index, yield strength and elastic stiffness coefficient of grown crystal has been investigated under microhardness study. The etching study has been carried out to determine the growth likelihood, nature of etch pits and surface quality of grown crystal.

  4. Stress corrosion mechanisms of alloy-600 polycrystals and monocrystals in primary water: effect of hydrogen

    Foct, F.

    1999-01-01

    The aim of this study is to identify the mechanisms involved in Alloy 600 primary water stress corrosion cracking. Therefore, this work is mainly focussed on the two following points. The first one is to understand the influence of hydrogen on SCC of industrial Alloy 600 and the second one is to study the crack initiation and propagation on polycrystals and single crystals. A cathodic potential applied during slow strain rate tests does not affect crack initiation but increases the slow crack growth rate by a factor 2 to 5. Cathodic polarisation, cold work and 25 cm 3 STP/kg hydrogen content increase the slow CGR so that the K ISCC (and therefore fast CGR) is reached. The influence of hydrogenated primary water has been studied for the first time on Alloy 600 single crystals. Cracks cannot initiate on tensile specimens but they can propagate on pre-cracked specimens. Transgranular cracks present a precise crystallographic aspect which is similar to that of 316 alloy in MgCl 2 solutions. Moreover, the following results improve the description of the cracking conditions. Firstly, the higher the hydrogen partial pressure, the lower the Alloy 600 passivation current transients. Since this result is not correlated with the effect of hydrogen on SCC, cracking is not caused by a direct effect of dissolved hydrogen on dissolution. Secondly, hydrogen embrittlement of Alloy 600 disappears at temperatures above 200 deg.C. Thirdly, grain boundary sliding (GBS) does not directly act on SCC but shows the mechanical weakness of grain boundaries. Regarding the proposed models for Alloy 600 SCC, it is possible to draw the following conclusions. Internal oxidation or absorbed hydrogen effects are the most probable mechanisms for initiation. Dissolution, internal oxidation and global hydrogen embrittlement models cannot explain crack propagation. On the other hand, the Corrosion Enhanced Plasticity Model gives a good description of the SCC propagation. (author)

  5. Electric conductivity of TlInTe2 monocrystal in strong electric fields

    Zarbaliev, M.M.; Godzhaev, Eh.M.; Gadzhiev, V.A.

    1980-01-01

    Electric condUctivity of the TlInTe 2 single crystal in strong electric fields has been studied in the range of 77-300 K. The electron part of the TlInTe 2 dielectric constant has been found to be 4. The dependence of the activation energy of current carriers on the electric field strength is constructed and the value of the activation energy of current carriers in the absence of an electric field is determined by the extrapolation method. The results of the experiments are in good agreement with the Frenkel-Pool theory, and this affords grounds for asserting that the obtained dependences of electric conductivity on temperature and the electric field strength are defined by variation in the current carrier concentration due to action of the thermal-electron ionization mechanism

  6. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Pal' -Val' , P.P.; Kaufmann, Kh.J.

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature dynamic annealing has been revealed in strained samples, that is almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  7. Electrical, optical and photoelectric properties of cadmium sulfide monocrystals doped by indium and irradiated by electrons

    Davidyuk, G E; Manzhara, V S

    2002-01-01

    One studied effect of irradiation by E = 1.2 MeV energy and PHI = 2 x 10 sup 1 sup 7 cm sup - sup 2 dose fast electrons on electrical, optical and photoelectrical CdS single-crystals doped by In. On the basis of analysis of the experimental results one makes conclusions about decomposition and, in this case, indium atoms occurring in cation sublattice nodes are knocked out by cadmium atoms. In CdS:In irradiated specimens one detected new centres of slow recombination with occurrence of maximums of photoconductivity optical suppression within lambda sub M sub sub 1 = 0.75 mu m and lambda sub M sub sub 2 = 1.03 mu m range. It is assumed that complexes containing cadmium vacancies and indium atoms are responsible for recombination new centres

  8. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Pal' -Val' , P.P. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur); Kaufmann, Kh.J. (Akademie der Wissenschaften der DDR, Berlin)

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples subjected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature ''dynamic annealing'' has been revealed in strained samples, that is, almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  9. 2-Amino-4-hydroxyethylaminoanisole sulfate

    Madsen, Jakob T; Andersen, Klaus E

    2016-01-01

    positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

  10. Scintillation properties of selected oxide monocrystals activated with Ce and Pr

    Wojtowicz, Andrzej J.; Drozdowski, Winicjusz; Wisniewski, Dariusz; Lefaucheur, Jean-Luc; Galazka, Zbigniew; Gou, Zhenhui; Lukasiewicz, Tadeusz; Kisielewski, Jaroslaw

    2006-01-01

    advantages and, after a likely improvement of some parameters, may also present a viable and desired alternative in applications that require high counting rates or better time resolution. Unfortunately, LuAP:Pr, although the fastest among all the materials studied, may be seriously limited in its achievable light yield by inherent physical processes that are responsible for nonradiative quenching of scintillation light in this material.

  11. Effects of magnesium sulfate on the acquisition and reinstatement of ...

    In the current study, the effects of magnesium sulfate on the acquisition and reinstatement of morphine-induced conditioned place preference (CPP) in an animal model were investigated. The acquisition and extinction and reinstatement phases induced using morphine 40 and 10mg/kg. Magnesium sulfate 300 and 600 ...

  12. Morpholine-4-carboxamidinium sulfate

    Ioannis Tiritiris

    2016-01-01

    Full Text Available The asymmetric unit of the title salt, 2C5H12N3O+·SO42−, comprises two cations and one sulfate ion. In both cations, the C, N and O atoms of the morpholine rings are disordered over two sets of sites, with refined occupancies of 0.849 (3:0.151 (3 for cation I and 0.684 (4:0.316 (4 for cation II. The C—N bond lengths in both central C3N units of the carboxamidinium ions range between 1.253 (12 and 1.362 (5 Å, indicating a degree of double-bond character. The central C atoms are bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charges are delocalized in both CN3 planes. The crystal structure is stabilized by a three-dimensional network of N—H...O hydrogen bonds between the cations and the sulfate ion. Scheme tiny font, charges and delocalized bonds almost invisible

  13. Presence of sulfate does not inhibit low-temperature dolomite precipitation

    Sánchez-Román, Mónica; McKenzie, Judith A.; de Luca Rebello Wagener, Angela; Rivadeneyra, Maria A.; Vasconcelos, Crisógono

    2009-01-01

    The hypothesis that sulfate inhibits dolomite formation evolved from geochemical studies of porewaters from deep-sea sedimentary sequences and has been tested with hydrothermal experiments. We examined the sulfate inhibition factor using aerobic culture experiments with Virgibacillus marismortui and

  14. A conductance study of guanidinium chloride, thiocyanate, sulfate, and carbonate in dilute aqueous solutions: ion-association and carbonate hydrolysis effects.

    Hunger, Johannes; Neueder, Roland; Buchner, Richard; Apelblat, Alexander

    2013-01-17

    We study the conductance of dilute aqueous solutions for a series of guandinium salts at 298.15 K. The experimental molar conductivities were analyzed within the framework of the Quint-Viallard theory in combination with Debye-Hückel activity coefficients. From this analysis, we find no evidence for significant ion association in aqueous solutions of guanidinium chloride (GdmCl) and guanidinium thiocyanate (GdmSCN), and the molar conductivity of these electrolytes can be modeled assuming a complete dissociation. The limiting ionic conductivity of the guanidinium ion (Gdm(+)) is accurately determined to λ(Gdm(+)) = 51.45 ± 0.10 S cm(2) mol(-1). For the bivalent salts guanidinium sulfate (Gdm(2)SO(4)) and guanidinium carbonate (Gdm(2)CO(3)), the molar conductivities show small deviations from ideal (fully dissociated electrolyte) behavior, which are related to weak ion association in solution. Furthermore, for solutions of Gdm(2)CO(3), the hydrolysis of the carbonate anion leads to distinctively increased molar conductivities at high dilutions. The observed ion association is rather weak for all studied electrolytes and cannot explain the different protein denaturing activities of the studied guanidinium salts, as has been proposed previously.

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

    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

  16. Effect of the Wetting Agent Sodium Lauryl Sulfate on the Pharmacokinetics of Alectinib: Results From a Bioequivalence Study in Healthy Subjects.

    Morcos, Peter N; Parrott, Neil; Banken, Ludger; Timpe, Carsten; Lindenberg, Marc; Guerini, Elena; Dall, Georgina; Bogman, Katrijn; Sturm, Carolina; Zeaiter, Ali; Martin-Facklam, Meret; Phipps, Alex

    2017-05-01

    The anaplastic lymphoma kinase (ALK) inhibitor alectinib is an effective treatment for ALK-positive non-small-cell lung cancer. This bioequivalence study evaluated the in vivo performance of test 3 formulations with the reduced wetting agent sodium lauryl sulfate (SLS) content. This randomized, 4-period, 4-sequence, crossover study compared alectinib (600 mg) as 25%, 12.5%, and 3% SLS hard capsule formulations with the reference 50% SLS clinical formulation in healthy subjects under fasted conditions (n = 49), and following a high-fat meal (n = 48). Geometric mean ratios and 90% confidence intervals (CIs) for C max , AUC 0-last , and AUC 0-∞ of alectinib, its major active metabolite, M4, and alectinib plus M4 were determined for the test formulations versus the reference formulation. Bioequivalence was concluded if the 90%CIs were within the 80% to 125% boundaries. The 25% SLS formulation demonstrated bioequivalence to the reference 50% SLS formulation for C max , AUC 0-last , and AUC 0-∞ of alectinib, M4, and alectinib plus M4 under both fasted and fed conditions. Further reductions in SLS content (12.5% and 3% SLS) did not meet the bioequivalence criteria. Cross-group comparisons showed an approximately 3-fold positive food effect. Reducing SLS to 25% resulted in a formulation that is bioequivalent to the current 50% SLS formulation used in alectinib pivotal trials. © 2016, The American College of Clinical Pharmacology.

  17. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    Sadeghi, Rahmat; Shahabi, Somayyeh

    2011-01-01

    Graphical abstract: Apparent molar volume against molality: o, ·, and Δ, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, Δ, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research highlights: → C 12 H 25 SO 3 Na(SDSn) was seen to interact with PEG more weakly than C 12 H 25 SO 4 Na(SDS). → The constraints on molecular mobility of SDS micelles are larger than those of SDSn. → Entropy change on micellization for SDSn is larger than those for SDS. → Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. → Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C 12 H 25 SO 4 Na) or sodium dodecyl sulfonate (C 12 H 25 SO 3 Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C 12 H 25 SO 4 Na and C 12 H 25 SO 3 Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C 12 H 25 SO 4 Na/C 12 H 25 SO 3 Na and PEG were studied and it was found that sodium alkyl sulfonates were seen to interact more weakly than their sulfate analogues.

  18. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    Sadeghi, Rahmat, E-mail: rsadeghi@uok.ac.ir [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Shahabi, Somayyeh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2011-09-15

    Graphical abstract: Apparent molar volume against molality: o, {center_dot}, and {Delta}, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, {Delta}, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research Highlights: > C{sub 12}H{sub 25}SO{sub 3}Na(SDSn) was seen to interact with PEG more weakly than C{sub 12}H{sub 25}SO{sub 4}Na(SDS). > The constraints on molecular mobility of SDS micelles are larger than those of SDSn. > Entropy change on micellization for SDSn is larger than those for SDS. > Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. > Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C{sub 12}H{sub 25}SO{sub 4}Na) or sodium dodecyl sulfonate (C{sub 12}H{sub 25}SO{sub 3}Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C{sub 12}H{sub 25}SO{sub 4}Na and C{sub 12}H{sub 25}SO{sub 3}Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C{sub 12}H{sub 25}SO{sub 4}Na/C{sub 12}H{sub 25}SO{sub 3}Na and PEG were studied and it was found that sodium alkyl sulfonates were seen

  19. INTRACELLULAR SYNTHESIS OF CHONDROITIN SULFATE

    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

  20. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  1. Sulfate reduction in an entrained-flow black liquor gasifier

    Kymaelaeinen, M.; Janka, K. [Tampella Power, Tampere (Finland); Frederick, W.J.; Littau, M.; Sricharoenchaikul, V.; Jivakanun, N.; Waag, K. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemical Engineering

    1995-12-31

    Sulfate reduction and carbon conversion during pyrolysis and gasification of black liquor particles were experimentally studied in a laminar entrained-flow reactor. A model was also developed to simulate an entrained-flow black liquor gasifier. Experimental results were then compared to model calculations. Results indicated that carbon must be present to get a high degree of sulfate reduction during gasification. It is therefore important to balance the rates of carbon conversion and sulfate reduction. High local temperatures in the reactor should be avoided so that carbon does not convert too rapidly, but temperatures of nearly 1000 degrees C are required to achieve good sulfate reduction. It was suggested that a new equation was needed to adequately predict sulfate reduction in an entrained-flow black liquor gasifier. 12 refs., 8 figs., 5 tabs.

  2. Study of total seed proteins pattern of sesame (sesamum indicum l.) landraces via sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page)

    Akbar, F.; Shinwari, Z.K.

    2012-01-01

    The sesame (Sesamum indicum L.) germplasm, comprising of 105 accessions was characterized for total seed storage proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The germplasm was collected from diverse agro-ecological regions of Pakistan. To our information, no studies have yet been carried out in Pakistan on the genetic evaluation of sesame genotypes based on total seed protein. Total seed proteins were electrophoretically separated on 12% polyacrylamide gels by standard protocols. A total of 20 polypeptide bands were observed, of which 14 (70%) were polymorphic and 6 (30%) were monomorphic, with molecular weight ranging from 13.5 to 100 kDa. Six bands i.e., 7, 11, 12, 15, 16 and 18 were common in all genotypes. Similarity coefficients varied fro m 0.50 to 1.00. The dendrogram based on dissimilarity matrix using unweighted pair group method with arithmetic averages (UPGMA) separated all sesame accessions into three main groups i.e., A, B, C, comprising 89, 14 and 2 genotypes, respectively. Overall a low to medium level of genetic variability was observed for SDS-PAGE (single dimension). As SDS-PAGE alone did not reveal high level of genetic variability, hence 2-D gel electrophoresis along with other advanced type DNA markers and more number of sesame accessions from all over the country are recommended for the future genetic evaluation. Our investigation will significantly support the classification, development, genetic evaluation and conservation of sesame germplasm in Pakistan. (author)

  3. Study of total seed proteins pattern of sesame (sesamum indicum l.) landraces via sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page)

    Akbar, F; Shinwari, Z K [Quaid-e-Azam University, Islamabad (Pakistan). Dept. of Biotechnology; Yousif, N; Masood, M S [Institute of Agri-Biotechnology and Genetic Resources, Islamabad (Pakistan)

    2012-11-15

    The sesame (Sesamum indicum L.) germplasm, comprising of 105 accessions was characterized for total seed storage proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The germplasm was collected from diverse agro-ecological regions of Pakistan. To our information, no studies have yet been carried out in Pakistan on the genetic evaluation of sesame genotypes based on total seed protein. Total seed proteins were electrophoretically separated on 12% polyacrylamide gels by standard protocols. A total of 20 polypeptide bands were observed, of which 14 (70%) were polymorphic and 6 (30%) were monomorphic, with molecular weight ranging from 13.5 to 100 kDa. Six bands i.e., 7, 11, 12, 15, 16 and 18 were common in all genotypes. Similarity coefficients varied fro m 0.50 to 1.00. The dendrogram based on dissimilarity matrix using unweighted pair group method with arithmetic averages (UPGMA) separated all sesame accessions into three main groups i.e., A, B, C, comprising 89, 14 and 2 genotypes, respectively. Overall a low to medium level of genetic variability was observed for SDS-PAGE (single dimension). As SDS-PAGE alone did not reveal high level of genetic variability, hence 2-D gel electrophoresis along with other advanced type DNA markers and more number of sesame accessions from all over the country are recommended for the future genetic evaluation. Our investigation will significantly support the classification, development, genetic evaluation and conservation of sesame germplasm in Pakistan. (author)

  4. A Comparative Study of Cyclic Oxidation and Sulfates-Induced Hot Corrosion Behavior of Arc-Sprayed Ni-Cr-Ti Coatings at Moderate Temperatures

    Guo, Wenmin; Wu, Yuping; Zhang, Jianfeng; Hong, Sheng; Chen, Liyan; Qin, Yujiao

    2015-06-01

    The cyclic oxidation and sulfates-induced hot corrosion behaviors of a Ni-43Cr-0.3Ti arc-sprayed coating at 550-750 °C were characterized and compared in this study. In general, all the oxidation and hot corrosion kinetic curves of the coating followed a parabolic law, i.e., the weight of the specimens showed a rapid growth initially and then reached the gradual state. However, the initial stage of the hot corrosion process was approximately two times longer than that of the oxidation process, indicating a longer preparation time required for the formation of a protective scale in the former process. At 650 °C, the parabolic rate constant for the hot corrosion was 7.2 × 10-12 g2/(cm4·s), approximately 1.7 times higher than that for the oxidation at the same temperature. The lower parabolic rate constant for the oxidation was mainly attributed to the formation of a protective oxide scale on the surface of corroded specimens, which was composed of a mixture of NiO, Cr2O3, and NiCr2O4. However, as the liquid molten salts emerged during the hot corrosion, these protective oxides would be dissolved and the coating was corrupted acceleratedly.

  5. Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation

    Hatada, Motoyoshi; Jonah, C.D.

    1994-10-01

    It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles in the solution with time during and after irradiation were studied using dynamic light scattering technique and UV spectrophotometer. The particles formed from palladium sulfate solution are found to be water-filled bulky particles of diameter of 200 nm, which grow by mutual coagulation even after irradiation was terminated. Average density depends on concentration of palladium ion in the solution and dose, and the lowest density was about 2 g/cm 3 for particles of 200 nm obtained from 0.06 mM solution by 2.4 kGy irradiation. The average density of the particles obtained from palladium sulfate-silver sulfate solutions was smaller than those obtained for the corresponding palladium sulfate solutions. Supersonic agitation destroyed coagulated precipitates to form fine particles, but did not form clusters of a few atoms. (author)

  6. NTP technical report on the toxicity studies of Cupric Sulfate (CAS No. 7758-99-8) Administered in Drinking Water and Feed to F344/N Rats and B6C3F1 Mice.

    Hebert, Charles

    1993-07-01

    Cupric sulfate is an inorganic salt which is widely used in industry, agriculture, and veterinary medicine. Its applications include use as an algicide in potable waters and as a feed additive and therapeutic agent in swine, sheep, and cattle. Because copper salts are found in human water supplies, toxicity studies of cupric sulfate pentahydrate were conducted in male and female F344/N rats and B6C3F1 mice by the drinking water (2-week studies only) and dosed feed routes (2-week and 13-week studies). Animals were evaluated for hematology, clinical chemistry, urinalysis, reproductive toxicity, tissue metal accumulation, and histopathology. In the 2-week drinking water studies, groups of five rats and five mice per sex received cupric sulfate at concentrations of 300 to 30,000 ppm for 15 days. One female rat, one male mouse, and three female mice in the 3000 ppm groups and all rats and mice in the 10,000 and 30,000 ppm groups died before the end of the studies. The remaining mice and rats in the 3000 ppm groups gained little or lost weight. Water consumption in the three highest dose groups of both species was reduced by more than 65%. Clinical signs observed in these groups were typical of those seen in moribund animals and were attributed to dehydration. The only gross or microscopic change specifically related to cupric sulfate toxicity was an increase in the size and number of cytoplasmic protein droplets in the epithelium of the renal proximal convoluted tubule in male rats from the 300 and 1000-ppm groups. In the 2-week feed studies, groups of five rats and five mice per sex were fed diets containing 1000 to 16,000 ppm cupric sulfate. No chemical-related deaths occurred in any dose group. Compared to the controls, rats and mice in the two highest dose groups had reduced body weight gains which were attributed to decreased feed consumption. Hyperplasia with hyperkeratosis of the squamous epithelium on the limiting ridge of the forestomach was seen in rats and

  7. Human O-sulfated metabolites of (-)-epicatechin and methyl-(-)-epicatechin are poor substrates for commercial aryl-sulfatases: implications for studies concerned with quantifying epicatechin bioavailability.

    Saha, S; Hollands, W; Needs, P W; Ostertag, L M; de Roos, B; Duthie, G G; Kroon, P A

    2012-06-01

    Epicatechin is a widely consumed dietary flavonoid and there is substantial evidence that it contributes to the health benefits reported for flavanol-rich cocoa products including dark chocolate. Numerous reports have described the appearance of epicatechin and epicatechin phase-2 conjugates (sulfates and glucuronides of epicatechin and methylepicatechin) in blood and urine samples of subjects following ingestion of epicatechin. The most widely reported method of quantifying total epicatechin in plasma and urine samples involves hydrolysis with a mixture of β-glucuronidase and sulfatase to convert the conjugates to epicatechin aglycone which is subsequently quantified. We observed a lack of hydrolysis of epicatechin sulfates and methylepicatechin sulfates using commercial sulfatases and investigated this further. Samples of urine or plasma from subjects who had consumed epicatechin were subjected to enzyme hydrolysis and then analysed using LC-MS/MS, or analysed without enzyme hydrolysis. Attempts to increase the extent of hydrolysis of epicatechin conjugates were made by increasing the amount of enzyme, hydrolysis pH and length of incubations, and using alternative sources of enzyme. The standard hydrolysis conditions failed to hydrolyse the majority of epicatechin sulfates and methylepicatechin sulfates. Even when the quantity of enzyme and incubation period was increased, the pH optimised, or alternative sources of sulfatases were used, epicatechin monosulfates and methylepicatechin monosulfates remained as major peaks in the chromatograms of the samples. An assessment of literature data strongly suggested that the majority of reports where enzyme hydrolysis was used had significantly underestimated epicatechin bioavailability in humans. Methods for quantifying epicatechin concentrations in blood and urine need to take account of the lack of hydrolysis of (methyl)epicatechin-sulfates, for example by quantifying these directly using LC-MS/MS. Copyright © 2012

  8. Oriented nucleation and growth of anhydrite during direct sulfation of limestone

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2008-01-01

    The direct sulfation of limestone (Iceland Spar) was studied at 973 K in a fixed-bed reactor. Scanning electron microscopy examinations of the sulfated limestone particles show that the sulfation process involves oriented nucleation and growth of the solid product, anhydrite. The reason...

  9. Comparative evaluation of antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate and Tween as surfactants: an in vivo study.

    Venu, V; Prabhakar, A R; Basappa, N

    2013-01-01

    The aim of the study was to determine the antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate (SLS) and Tween as surfactants. It is a double-blind cross over the study, a total of 20 children within their mixed dentition period (7-13 year) having Streptococci mutans count more than 10(6) were selected for the main study. Three types of chlorhexidine containing dentifrices were used with a washout period of 1 week. Out of the three toothpastes, one was without surfactant and other two toothpastes contained SLS and Tween as surfactants respectively. 20 volunteers brushed for 1 min during the study day with their assigned toothpaste. Saliva samples were collected before brushing, immediately after brushing and 1, 3, 5, and 7 hand sent for microbial analysis. The culture carried out by inoculating saliva sample onto Mitis salivarius agar for selective isolation of S. mutans followed by counting of colony forming unit. Group I and III (Chlorhexidine and CHX + Tween) had shown statistically significant reduction in bacterial count until 7 h when compared to their baseline values ( P < 0.001). Group II toothpaste (CHX + SLS) had shown significant reduction in bacterial count until 3 h only. On inter group comparison, Group III had shown good amount of percentage reduction in bacterial count when compared to other groups. CHX + Tween toothpaste had shown statistically significant reduction in antibacterial activity and substantivity than other groups. These findings show chlorhexidine containing toothpaste with non-ionic surfactant will be able to maintain the antibacterial property and substantivity of chlorhexidine.

  10. Comparative evaluation of antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate and Tween as surfactants: An in vivo study

    V Venu

    2013-01-01

    Full Text Available Aim: The aim of the study was to determine the antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate (SLS and Tween as surfactants. Materials and Methods: It is a double-blind cross over the study, a total of 20 children within their mixed dentition period (7-13 year having Streptococci mutans count more than 10 6 were selected for the main study. Three types of chlorhexidine containing dentifrices were used with a washout period of 1 week. Out of the three toothpastes, one was without surfactant and other two toothpastes contained SLS and Tween as surfactants respectively. 20 volunteers brushed for 1 min during the study day with their assigned toothpaste. Saliva samples were collected before brushing, immediately after brushing and 1, 3, 5, and 7 hand sent for microbial analysis. The culture carried out by inoculating saliva sample onto Mitis salivarius agar for selective isolation of S. mutans followed by counting of colony forming unit. Results: Group I and III (Chlorhexidine and CHX + Tween had shown statistically significant reduction in bacterial count until 7 h when compared to their baseline values ( P < 0.001. Group II toothpaste (CHX + SLS had shown significant reduction in bacterial count until 3 h only. On inter group comparison, Group III had shown good amount of percentage reduction in bacterial count when compared to other groups. Conclusion: CHX + Tween toothpaste had shown statistically significant reduction in antibacterial activity and substantivity than other groups. These findings show chlorhexidine containing toothpaste with non-ionic surfactant will be able to maintain the antibacterial property and substantivity of chlorhexidine.

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

    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

  12. Biological sulfate removal from gypsum contaminated construction and demolition debris.

    Kijjanapanich, Pimluck; Annachhatre, Ajit P; Esposito, Giovanni; van Hullebusch, Eric D; Lens, Piet N L

    2013-12-15

    Construction and demolition debris (CDD) contains high levels of sulfate that can cause detrimental environmental impacts when disposed without adequate treatment. In landfills, sulfate can be converted to hydrogen sulfide under anaerobic conditions. CDD can thus cause health impacts or odor problems to landfill employees and surrounding residents. Reduction of the sulfate content of CDD is an option to overcome these problems. This study aimed at developing a biological sulfate removal system to reduce the sulfate content of gypsum contaminated CDD in order to decrease the amount of solid waste, to improve the quality of CDD waste for recycling purposes and to recover sulfur from CDD. The treatment leached out the gypsum contained in CDD by water in a leaching column. The sulfate loaded leachate was then treated in a biological sulfate reducing Upflow Anaerobic Sludge Blanket (UASB) reactor to convert the sulfate to sulfide. The UASB reactor was operated at 23 ± 3 °C with a hydraulic retention time and upflow velocity of 15.5 h and 0.1 m h(-1), respectively while ethanol was added as electron donor at a final organic loading rate of 3.46 g COD L(-1) reactor d(-1). The CDD leachate had a pH of 8-9 and sulfate dissolution rates of 526.4 and 609.8 mg L(-1) d(-1) were achieved in CDD gypsum and CDD sand, respectively. Besides, it was observed that the gypsum dissolution was the rate limiting step for the biological treatment of CDD. The sulfate removal efficiency of the system stabilized at around 85%, enabling the reuse of the UASB effluent for the leaching step, proving the versatility of the bioreactor for practical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Heparan sulfate and cell division

    Porcionatto M.A.

    1999-01-01

    Full Text Available Heparan sulfate is a component of vertebrate and invertebrate tissues which appears during the cytodifferentiation stage of embryonic development. Its structure varies according to the tissue and species of origin and is modified during neoplastic transformation. Several lines of experimental evidence suggest that heparan sulfate plays a role in cellular recognition, cellular adhesion and growth control. Heparan sulfate can participate in the process of cell division in two distinct ways, either as a positive or negative modulator of cellular proliferation, or as a response to a mitogenic stimulus.

  14. Conversion electron Moessbauer study of low carbon steel polarized in aqueous sulfate solution containing sulfite in low concentration

    Vertes, Cs.; Lakatos-Varsanyi, M.; Vertes, A.; Kuzmann, E.; Meisel, W.; Guetlich, P.

    1992-01-01

    The passivation of low carbon steel was studied in aqueous solution of 0.5 M Na 2 SO 4 +0.001 M NaHSO 3 at pH=3.5 and 6.5. The found major components at pH=3.5 were: γ-FeOOH and Fe 3 C, and also FeSO 4 .H 2 O could be identified on the surface of the low carbon steel as a minor component. At pH=6.5, the passive film contained only amorphous iron(III)-oxide or oxyhydroxide. (orig.)

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

    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.

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

    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.

  17. Sodium lauryl sulfate enhances nickel penetration through guinea-pig skin. Studies with energy dispersive X-ray microanalysis

    Lindberg, M.; Sagstroem, S.R.; Roomans, G.M.; Forslind, B.

    1989-01-01

    The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis (EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na, Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX allows analysis of the influence of different factors involved in nickel penetration through the skin by giving data on the physiological effects on the epidermal cells caused by the applied substances

  18. Histopathological and bacterial study of skin and gill of grass carp, Ceteopharyngodon idella, (Valenciennes 1844) exposed to copper sulfate and potassium permanganate.

    Jooyandeh, Fatemeh; Sadeghpour, Ali; Khara, Hossein; Pajand, Zabihollah

    2016-09-01

    The gill histology and bacterial load of skin of the grass carp juveniles were investigated in relation to various concentrations of copper sulfate and potassium permanganate. For this purpose, the sublethal doses were determined after a pre-test and then the experiment was done in five treatments (for copper sulfate: 1, 1.94, 3.71, 7.07 and 15 mg/l and for potassium permanganate: 0.25, 0.52, 1.91, 2.27 and 5 mg/l) with three replicates inside the glass aquaria. Also, one group without disinfecting product was considered as control for each experiment. The microbial and histopathological investigations were done after 96 h exposure. According to results, the lowest bacterial load (CFU/g) of skin was observed in 15 mg/l copper sulfate treatment and 0.25 mg/l potassium permanganate treatment (P permanganate. In this regard, the highest histological damages were observed in 15 mg/l copper sulfate and 5 mg/l potassium permanganate respectively. Our results showed that low dosage of potassium permanganate has best effect on reducing of bacterial load of skin with lowest adverse effects on gill tissue.

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

    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.

  20. High covalence in CuSO4 and the radicalization of sulfate: an X-ray absorption and density functional study.

    Szilagyi, Robert K; Frank, Patrick; DeBeer George, Serena; Hedman, Britt; Hodgson, Keith O

    2004-12-27

    Sulfur K-edge X-ray absorption spectroscopy (XAS) of anhydrous CuSO(4) reveals a well-resolved preedge transition feature at 2478.8 eV that has no counterpart in the XAS spectra of anhydrous ZnSO(4) or copper sulfate pentahydrate. Similar but weaker preedge features occur in the sulfur K-edge XAS spectra of [Cu(itao)SO(4)] (2478.4 eV) and [Cu[(CH(3))(6)tren]SO(4)] (2477.7 eV). Preedge features in the XAS spectra of transition metal ligands are generally attributed to covalent delocalization of a metal d-orbital hole into a ligand-based orbital. Copper L-edge XAS of CuSO(4) revealed that 56% of the Cu(II) 3d hole is delocalized onto the sulfate ligand. Hybrid density functional calculations on the two most realistic models of the covalent delocalization pathways in CuSO(4) indicate about 50% electron delocalization onto the sulfate oxygen-based 2p orbitals; however, at most 14% of that can be found on sulfate sulfur. Both experimental and computational results indicated that the high covalence of anhydrous CuSO(4) has made sulfate more like the radical monoanion, inducing an extensive mixing and redistribution of sulfur 3p-based unoccupied orbitals to lower energy in comparison to sulfate in ZnSO(4). It is this redistribution, rather than a direct covalent interaction between Cu(II) and sulfur, that is the origin of the observed sulfur XAS preedge feature. From pseudo-Voigt fits to the CuSO(4) sulfur K-edge XAS spectrum, a ground-state 3p character of 6% was quantified for the orbital contributing to the preedge transition, in reasonable agreement with the DFT calculation. Similar XAS fits indicated 2% sulfur 3p character for the preedge transition orbitals in [Cu(itao)SO(4)] and [Cu[(CH(3))(6)tren]SO(4)]. The covalent radicalization of ligands similar to sulfate, with consequent energy redistribution of the virtual orbitals, represents a new mechanism for the induction of ligand preedge XAS features. The high covalence of the Cu sites in CuSO(4) was found to be

  1. Effect of a Long Chain Carboxylate Acid on Sodium Dodecyl Sulfate Micelle Structure: A Small-angle Neutron Scattering Study

    Arum Patriati; Edy Giri Rachman Putra

    2009-01-01

    The effect of different hydrocarbon chain length of carboxylate acid, i.e. dodecanoic acid, CH 3 (CH 2 ) 10 COOH and hexadecanoic acid, CH 3 (CH 2 ) 14 COOH as a co-surfactant in the 0.3M SDS micellar solution has been studied using small angle neutron scattering (SANS). Here, the present of dodecanoic acid has induced the SDS structural micelles. The ellipsoid micelles structures changed significantly in length (major axis) from 21.7 Armstrong to 35.5 Armstrong at a fixed minor axis of 16.7 Armstrong in the present of 0.005M to 0.1M dodecanoic acid. Nevertheless, this effect was not shown in the present of hexadecanoic acid with the same concentration range. The present of hexadecanoic acid molecules gave a small effect on growth of SDS micelles where the major axis of the micelle was simply elongated from 21.5 Armstrong to 23.5 Armstrong. It showed that the appropriate hydrocarbon chain length between surfactant and co-surfactant molecules is one of the determining factors in forming a mixed micelles structure. (author)

  2. Mercury mobilization and speciation linked to bacterial iron oxide and sulfate reduction: A column study to mimic reactive transfer in an anoxic aquifer.

    Hellal, Jennifer; Guédron, Stéphane; Huguet, Lucie; Schäfer, Jörg; Laperche, Valérie; Joulian, Catherine; Lanceleur, Laurent; Burnol, André; Ghestem, Jean-Philippe; Garrido, Francis; Battaglia-Brunet, Fabienne

    2015-09-01

    Mercury (Hg) mobility and speciation in subsurface aquifers is directly linked to its surrounding geochemical and microbial environment. The role of bacteria on Hg speciation (i.e., methylation, demethylation and reduction) is well documented, however little data is available on their impact on Hg mobility. The aim of this study was to test if (i) Hg mobility is due to either direct iron oxide reduction by iron reducing bacteria (IRB) or indirect iron reduction by sulfide produced by sulfate reducing bacteria (SRB), and (ii) to investigate its subsequent fate and speciation. Experiments were carried out in an original column setup combining geochemical and microbiological approaches that mimic an aquifer including an interface of iron-rich and iron depleted zones. Two identical glass columns containing iron oxides spiked with Hg(II) were submitted to (i) direct iron reduction by IRB and (ii) to indirect iron reduction by sulfides produced by SRB. Results show that in both columns Hg was leached and methylated during the height of bacterial activity. In the column where IRB are dominant, Hg methylation and leaching from the column was directly correlated to bacterial iron reduction (i.e., Fe(II) release). In opposition, when SRB are dominant, produced sulfide induced indirect iron oxide reduction and rapid adsorption of leached Hg (or produced methylmercury) on neoformed iron sulfides (e.g., Mackinawite) or its precipitation as HgS. At the end of the SRB column experiment, when iron-oxide reduction was complete, filtered Hg and Fe concentrations increased at the outlet suggesting a leaching of Hg bound to FeS colloids that may be a dominant mechanism of Hg transport in aquifer environments. These experimental results highlight different biogeochemical mechanisms that can occur in stratified sub-surface aquifers where bacterial activities play a major role on Hg mobility and changes in speciation. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis

    Holmborn, Katarina; Habicher, Judith; Kasza, Zsolt

    2012-01-01

    The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS and CS because of defective formation...... levels of CS than control larvae, whereas morpholino-mediated suppression of csgalnact1/csgalnact2 resulted in increased HS biosynthesis. Thus, the balance of the Extl3 and Csgalnact1/Csgalnact2 proteins influences the HS/CS ratio. A characterization of the pharyngeal cartilage element morphologies...

  4. Protection and repair of post-thrombolytic brain tissue with high-dose human albumin and magnesium sulfate: an experimental study

    Li Yongdong; Zhao Jungong; Li Minghua; You Xiaofang; Chen Yingsheng

    2008-01-01

    Objective: To evaluate the neuroprotective effects of high-dose human albumin and magnesium sulfate combined with recombinant tissue plasminogen activator (rt-PA) thrombolysis in a SD rat model of embolic stroke, with the aim to explore the possibility of extention for thrombolytic window. Methods: A thromboembolic stroke model performed on male SD rats (n=40) was randomly assigned into four groups: group A (n=10): rats received an intravenous infusion of 10 mg/kg rt-PA over a period of one hour at 3 h after onset of MCAO; group B (n=10): rats received an intravenous infusion of 10 mg/kg rt-PA over a period of one hour at 6 h after onset of MCAO; group C(n=10): rats received an intravenous infusion of human albumin (2.5 g/kg) and rt-PA(10 mg/kg) at 3 h and 6 h after onset of MCAO; group D(n=10): rats received same dose human albumin and rt-PA as that in group C, in addition, magnesium salfate (500 mg/ kg) was given intraperitoneally 3 h and 18 h after onset of MCAO. MRI was performed in each animal at preischemia, 24 h, 7 d and 14 d after treatment. After the last MR examination, all animals were killed under anesthesia, pathologic study (including electron microscope, light microscope, immuno-histochemistry) was performed in each animal, and LSCM were performed in two animals of each group. Results: The infarct volumes in four groups at 14 d after thrombolysis reduced 5.07% , 2.58%, 10.18% and 35.40% respectively compared with the infarct volume at 3 h after MCAO, with a predominant reduction in group D (P<0.05); increase of rCBV was confirmed at the marginal area of the cerebral infarction from the onset of stroke to 14 d, with significant increase between group A and C from 1 d to 7 d (P<0.05), while no significant difference was found in group B and C. The longest survival exhibited in group D and the shortest in group B, and no significant difference occurred concerning about survival among the four groups (P=0.763, P=0.636). In addition, LSCM showed a slight

  5. Neutralization study of boron and some metallic impurities (gold, titanium, manganese, chromium) by hydrogen implantation in monocrystal silicon

    Zundel, T.

    1987-02-01

    Boron doped silicon implanted with hydrogen at low energy in the temperature range 80-140 0 C shows a large decrease of the electrically active dopant concentration up to a depth which increases with the temperature, the implantation duration and the starting material resistivity. This effect is assigned to the formation of an electrically inactive BH complex. The hydrogen incorporation process shows a weakly temperature dependent enhanced diffusion step followed by a normal diffusion phase which may be described by a thermally activated diffusion coefficient. Heating at 80 0 C produces a complete dissociation of the BH complexes in the space charge region of reverse biased Schottky diodes. Consequently the released hydrogen drifts under the electric field and the neutralization becomes more pronounced in the bulk. Hydrogen neutralizes the gold, chromium, manganese related deep levels but has no effect on titanium related defect levels. Thermal annealing at 495 0 C of hydrogenated chromium or manganese doped samples produces four majority carriers levels which disappear at 700 0 C [fr

  6. Sulfated oligosaccharide structures, as determined by NMR techniques

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J. [Parana Univ., Curitiba, PR (Brazil). Dept. De Bioquimica; Cerezo, A.S. [Buenos Aires Univ. Nacional (Argentina). Dept. de Quimica Organica

    1997-12-31

    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a {lambda}-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author) 4 refs., 8 figs., 1 tabs.

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

    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.

  8. Tyrosine sulfation, a post-translational modification of microvillar enzymes in the small intestinal enterocyte

    Danielsen, E M

    1987-01-01

    Protein sulfation in small intestinal epithelial cells was studied by labelling of organ cultured mucosal explants with [35S]-sulfate. Six bands in SDS-PAGE became selectively labelled; four, of 250, 200, 166 and 130 kd, were membrane-bound and two, of 75 and 60 kd, were soluble. The sulfated mem...... sulfated. Most if not all the sulfate was bound to tyrosine residues rather than to the carbohydrate of the microvillar enzymes, showing that this type of modification can occur on plasma membrane proteins as well as on secretory proteins....

  9. Influence of Internal Sulfate Attack on Some Properties of High Strength Concrete

    Nada Mahdi Fawzi

    2015-08-01

    Full Text Available One of the most important problems that faces the concrete industry in Iraq is the deterioration due to internal sulfate attack , since it reduces the compressive strength and increases the expansion of concrete. Consequently, the concrete structure may be damage .The effects of total and total effective sulfate contents on high strength concrete (HSC have been studied in the present study. The research studied the effect of sulfate content in cement , sand and gravel , as well as comparing the total sulfate content with the total effective SO3 content. Materials used were divided into two groups of SO3 in cement ,three groups of SO3 in sand ,and two groups of SO3 in gravel. The results show that considering the total effective sulfate content is better than the total content of sulfates since the effect of sulfate in each constituent of concrete, depends on it's granular size .The smaller the particle size of the material the more effective is the sulfate in it. Therefore, it is recommended to follow the Iraqi specification for total effective sulfate content, because it gives more flexibility to the use of sand and gravel with higher sulfate content. The results of compressive strength at 90-days show that the effect of total effective SO3 content of ( 2.647% , 2.992% , 3.424% that correspond to total sulfate of ( 3.778%, 3.294%, 4.528% decrease the compressive strength by (7.53%, 11.44%, 14.59% respectively.

  10. Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

    Yang, Yang [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Wang, Hailong [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Smith, Steven J. [Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park MD USA; Easter, Richard C. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Rasch, Philip J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA

    2018-02-08

    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 burden 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.

  11. Evolutionary relationships and functional diversity of plant sulfate transporters

    Hideki eTakahashi

    2012-01-01

    Full Text Available 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 sulfate transporters (SUL and animal anion exchangers (SLC26. The lineage of plant SULTR family is expanded into four subfamilies (SULTR1 to SULTR4 in land plant species. By contrast, the putative SULTR homologues 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 completely absent in the angiosperm species analyzed. The present study suggests distinct evolutionary trajectories of sulfate transport systems for land plants and green algae.

  12. [Efficacy and safety of tulobuterol patch versus oral salbutamol sulfate in children with mild or moderate acute attack of bronchial asthma: a comparative study].

    Lin, Qian; Liu, Quan-Hua; Bao, Yi-Xiao

    2013-06-01

    To compare tulobuterol patch and oral salbutamol sulfate in terms of efficacy and safety in children with mild or moderate acute attack of bronchial asthma. A total of 92 children with mild and moderate acute asthmatic attack were randomly divided into salbutamol group (n=46) and tulobuterol group (n=46). Both groups received routine treatment with antihistamine, selective leukotriene receptor antagonist and glucocorticoid. In addition, the salbutamol group was given slow-release capsules of salbutamol sulfate, and the tulobuterol group was treated with tulobuterol patch. The two groups were compared with respect to symptom scores of cough, wheeze, respiratory rate, wheezing sound, three depression sign and peak expiratory flow, as well as adverse events. As the treatment proceeded, symptom scores decreased in both groups; on the third day of treatment, all symptom scores except cough score showed a significant decrease in both groups (Pattack.

  13. Double-blind, randomized crossover study of intravenous infusion of magnesium sulfate versus 5% dextrose on depressive symptoms in adults with treatment-resistant depression.

    Mehdi, Syed M A; Atlas, Steven E; Qadir, Sidra; Musselman, Dominique; Goldberg, Sharon; Woolger, Judi M; Corredor, Raul; Abbas, Muhammad H; Arosemena, Leopoldo; Caccamo, Simone; Campbell, Carmen S G; Farooqi, Ashar; Gao, Jinrun; Konefal, Janet; Lages, Lucas C; Lantigua, Laura; Lopez, Johanna; Padilla, Vanessa; Rasul, Ammar; Ray, Anna M; Simões, Herbert G; Tiozzo, Eduard; Lewis, John E

    2017-03-01

    Treatment-resistant depression patients are more likely to suffer from comorbid physical and mental disorders, experience marked and protracted functional impairment, and incur higher health-care costs than non-affected individuals. Magnesium sulfate is a treatment option that may offer great potential for patients with treatment-resistant depression based on prior work in animals and humans. Twelve subjects with mild or moderate treatment-resistant depression were randomized into a double-blind crossover trial to receive an infusion of 4 g of magnesium sulfate in 5% dextrose or placebo infusion of 5% dextrose with a 5-day washout in between the 8-day intervention period. Subjects were assessed before and after the intervention for serum and urine magnesium, lipid panel, the Hamilton Rating Scale for Depression, and the Patient Health Questionnaire-9. We found a difference in serum magnesium from day 2 to 8 (pre-infusion) (P < 0.002) and from baseline to day 8 (P < 0.02). No changes were noted on the Hamilton Rating Scale for Depression or the Patient Health Questionnaire-9 24 h post-treatment, but as serum magnesium increased from baseline to day 7, the Patient Health Questionnaire-9 decreased from baseline to day 7 (P = 0.02). Magnesium sulfate did not significantly affect depression 24 h post-infusion, but other results were consistent with the literature. The association between changes in serum magnesium and the Patient Health Questionnaire-9 supports the idea that magnesium sulfate may be used to address treatment-resistant depression, an ongoing medical challenge. © 2016 The Authors Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

  14. Subchronic (26- and 52-week) toxicity and irritation studies of a novel microbicidal gel formulation containing sodium lauryl sulfate in animal models.

    Piret, Jocelyne; Laforest, Geneviève; Bussières, Martin; Bergeron, Michel G

    2008-03-01

    The safety of an ethylene oxide/propylene oxide gel formulation containing sodium lauryl sulfate (2%, w/w), that could be a potent candidate as a topical microbicide, has been evaluated. More specifically, the subchronic (26- and 52-week) toxicity of the formulation when applied intravaginally as well as its irritating potential for the rectal, penile, eye, skin and buccal mucosa have been examined in animal models. The results showed that the vaginal administration of the gel formulation containing sodium lauryl sulfate once and twice daily (with doses 12 +/- 2 h apart) for 26 weeks to rats and for 52 weeks to rabbits induced slight to moderate histopathological alterations. When the formulation was applied intrarectally to male and female rabbits once and twice daily (with doses 12 +/- 2 h apart) for 14 days, no macroscopic or microscopic changes were reported. For both vaginal and rectal dosing, no effect was seen on the haematology, coagulation and serum chemistry parameters as well as on the body weight of animals and the relative organ weights. Other sporadic macroscopic and histopathological findings were incidental in origin and of no toxicological significance. The gel formulation containing sodium lauryl sulfate was considered as mildly irritating for the penile mucosa of rabbits, non-irritating for the eye of rabbits, mildly irritating for the skin in a rabbit model and non-irritating for the hamster cheek pouch. It is suggested that the gel formulation containing sodium lauryl sulfate is safe for most tissues that could be exposed to the product under normal use.

  15. Incorporation of 35S-sulfate and 3H-glucosamine into heparan and chondroitin sulfates during the cell cycle of B16-F10 cells

    Blair, O.C.; Sartorelli, A.C.

    1984-01-01

    Changes in glycosaminoglycan composition occurring during the cell cycle were determined in B16-F10 cells sorted flow cytometrically with respect to DNA content. Incorporation of 35 S-sulfate into heparan sulfate and chondroitin sulfate of unsorted and G1,S, and G2 +M sorted cells was determined following chondroitinase ABC or nitrous acid treatment; the incorporation into surface material was measured as the difference between the radioactivity of control and trypsin-treated cells. Incorporation of 35 S-sulfate and 3 H-glucosamine into cetyl pyridinium chloride (CPC)-precipitable material was characterized before and after chondroitinase or nitrous acid treatment by Sephadex G50 chromatography. Long-term (48 h) and short-term (1 h) labeling studies demonstrate that (a) the amount of total cellular chondroitin sulfate is greater than that of heparan sulfate, with larger amounts of unsulfated heparan than chondroitin being present; (b) the rate of turnover of heparan sulfate is greater than that of chondroitin sulfate; (c) greatest short-term incorporation of 3H-glucosamine into CPC-precipitable material occurs during S phase; and (d) the rate of turnover of both heparan sulfate and chondroitin sulfate is decreased in S phase relative to G1 and G2 + M

  16. Predictive mapping of the acidifying potential for acid sulfate soils

    Boman, A; Beucher, Amélie; Mattbäck, S

    Developing methods for the predictive mapping of the potential environmental impact from acid sulfate soils is important because recent studies (e.g. Mattbäck et al., under revision) have shown that the environmental hazards (e.g. leaching of acidity) related to acid sulfate soils vary depending...... on their texture (clay, silt, sand etc.). Moreover, acidity correlates, not only with the sulfur content, but also with the electrical conductivity (EC) measured after incubation. Electromagnetic induction (EMI) data collected from an EM38 proximal sensor also enabled the detailed mapping of acid sulfate soils...... over a field (Huang et al., 2014).This study aims at assessing the use of EMI data for the predictive mapping of the acidifying potential in an acid sulfate soil area in western Finland. Different supervised classification modelling techniques, such as Artificial Neural Networks (Beucher et al., 2015...

  17. Biosynthesis and function of chondroitin sulfate.

    Mikami, Tadahisa; Kitagawa, Hiroshi

    2013-10-01

    Chondroitin sulfate proteoglycans (CSPGs) are principal pericellular and extracellular components that form regulatory milieu involving numerous biological and pathophysiological phenomena. Diverse functions of CSPGs can be mainly attributed to structural variability of their polysaccharide moieties, chondroitin sulfate glycosaminoglycans (CS-GAG). Comprehensive understanding of the regulatory mechanisms for CS biosynthesis and its catabolic processes is required in order to understand those functions. Here, we focus on recent advances in the study of enzymatic regulatory pathways for CS biosynthesis including successive modification/degradation, distinct CS functions, and disease phenotypes that have been revealed by perturbation of the respective enzymes in vitro and in vivo. Fine-tuned machineries for CS production/degradation are crucial for the functional expression of CS chains in developmental and pathophysiological processes. Control of enzymes responsible for CS biosynthesis/catabolism is a potential target for therapeutic intervention for the CS-associated disorders. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Semi-synthesis of chondroitin sulfate-E from chondroitin sulfate-A

    Cai, Chao; Solakyildirim, Kemal; Yang, Bo; Beaudet, Julie M.; Weyer, Amanda; Linhardt, Robert J.; Zhang, Fuming

    2012-01-01

    Chondroitin sulfate-E (chondroitin-4, 6-disulfate) was prepared from chondroitin sulfate-A (chondroitin-4 - sulfate) by regioselective sulfonation, performed using trimethylamine sulfur trioxide in formamide under argon. The structure of semi-synthetic chondroitin sulfate-E was analyzed by PAGE, 1H NMR, 13C NMR, 2D NMR and disaccharide analysis and compared with natural chondroitin sulfate-E. Both semi-synthetic and natural chondroitin sulfate-E were each biotinylated and immobilized on BIAco...

  19. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  20. Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta).

    Lee, Wei-Kang; Namasivayam, Parameswari; Ong Abdullah, Janna; Ho, Chai-Ling

    2017-04-24

    Seaweeds survive in marine waters with high sulfate concentration compared to those living at freshwater habitats. The cell wall polymer of Gracilaria spp. which supplies more than 50% of the world agar is heavily sulfated. Since sulfation reduces the agar quality, it is interesting to investigate the effects of sulfate deprivation on the sulfate contents of seaweed and agar, as well as the metabolic pathways of these seaweeds. In this study, two agarophytes G. changii and G. salicornia were treated under sulfate deprivation for 5 days. The sulfate contents in the seaweed/agar were generally lower in sulfate-deprivated samples compared to those in the controls, but the differences were only statistically significant for seaweed sample of G. changii and agar sample of G. salicornia. RNA sequencing (RNA-Seq) of sulfate-deprivated and untreated seaweed samples revealed 1,292 and 3,439 differentially expressed genes (DEGs; ≥1.5-fold) in sulfate-deprivated G. changii and G. salicornia, respectively, compared to their respective controls. Among the annotated DEGs were genes involved in putative agar biosynthesis, sulfur metabolism, metabolism of sulfur-containing amino acids, carbon metabolism and oxidative stress. These findings shed light on the sulfate deprivation responses in agarophytes and help to identify candidate genes involved in agar biosynthesis.

  1. A New Ursane type Sulfated Saponin from Zygophyllum fabago Linn.

    Saleha Suleman Khan

    2014-07-01

    Full Text Available One new sulfated saponin 3β,23,30-trihydroxyurs-20-en-28-al-23-sulfate 3-O-β- D -xylopyranoside (Zygofaboside C; 1 was purified from the water soluble fraction of ethanolic extract of the aerial parts of Zygophyllum fabago Linn. The structure of the compound was elucidated through spectral studies, especially 1D- and 2D-NMR, HR-FAB mass spectrometry, and comparison with literature data.

  2. Alkylation of isobutane by butenes on zirconium sulfate catalysts

    Lavrenov, A.V.; Perelevskij, E.V.; Finevich, V.P.; Zajkovskij, V.I.; Paukshtis, E.A.; Duplyakiv, V.K.; Bal'zhinimaev, B.S.

    2003-01-01

    Preparation of applied zirconium sulfate catalysts obtained by the method of impregnation is investigated. Results of comparative study of structural, acid-base and catalytic properties of sulfated zirconium dioxide applied on silica gel and aluminium oxide are represented. Intervals of values of synthesis basic parameters and characteristics of catalysts properties providing achievement of high activity and selectivity in isobutane alkylation by butenes in liquid phase are determined [ru

  3. Intravesical administration of combined hyaluronic acid (HA) and chondroitin sulfate (CS) for the treatment of female recurrent urinary tract infections: a European multicentre nested case-control study.

    Ciani, Oriana; Arendsen, Erik; Romancik, Martin; Lunik, Richard; Costantini, Elisabetta; Di Biase, Manuel; Morgia, Giuseppe; Fragalà, Eugenia; Roman, Tomaskin; Bernat, Marian; Guazzoni, Giorgio; Tarricone, Rosanna; Lazzeri, Massimo

    2016-03-31

    To compare the clinical effectiveness of the intravesical administration of combined hyaluronic acid and chondroitin sulfate (HA+CS) versus current standard management in adult women with recurrent urinary tract infections (RUTIs). A European Union-based multicentre, retrospective nested case-control study. 276 adult women treated for RUTIs starting from 2009 to 2013. Patients treated with either intravesical administration of HA+CS or standard of care (antimicrobial/immunoactive prophylaxis/probiotics/cranberry). The primary outcome was occurrence of bacteriologically confirmed recurrence within 12 months. Secondary outcomes were time to recurrence, total number of recurrences, health-related quality of life and healthcare resource consumption. Crude and adjusted results for unbalanced characteristics are presented. 181 patients treated with HA+CS and 95 patients treated with standard of care from 7 centres were included. The crude and adjusted ORs (95% CI) for the primary end point were 0.77 (0.46 to 1.28) and 0.51 (0.27 to 0.96), respectively. However, no evidence of improvement in terms of total number of recurrences (incidence rate ratio (95% CI), 0.99 (0.69 to 1.43)) or time to first recurrence was seen (HR (95% CI), 0.99 (0.61 to 1.61)). The benefit of intravesical HA+CS therapy improves when the number of instillations is ≥ 5. Our results show that bladder instillations of combined HA+CS reduce the risk of bacteriologically confirmed recurrences compared with the current standard management of RUTIs. Total incidence rates and hazard rates were instead non-significantly different between the 2 groups after adjusting for unbalanced factors. In contrast to what happens with antibiotic prophylaxis, the effectiveness of the HA+CS reinstatement therapy improves over time. NCT02016118. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Initial kinetics of the direct sulfation of limestone

    Hu, Guilin; Shang, Lei; Dam-Johansen, Kim

    2008-01-01

    The initial kinetics of direct sulfation of Faxe Bryozo, a porous bryozoan limestone was studied in the temperature interval from 873 to 973 K in a pilot entrained flow reactor with very short reaction times (between 0.1 and 0.6 s). The initial conversion rate of the limestone - for conversions...... less than 0.3% - was observed to be significantly promoted by higher SO2 concentrations and lower CO2 concentrations, whereas 02 showed negligible influence. A mathematical model for the sulfation of limestone involving chemical reaction at calcite grain surfaces and solid-state diffusion of carbonate...... ions in calcite grains is established. The validity of the model is limited to the initial sulfation period, in which nucleation of the solid product calcium sulphate is not started. This theoretical reaction-diffusion model gives a good simulation of the initial kinetics of the direct sulfation...

  5. Chondroitin sulfate effects on neural stem cell differentiation.

    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.

  6. Regional transport model of atmospheric sulfates

    Rao, K.S.; Thomson, I.; Egan, B.A.

    1977-01-01

    As part of the Sulfate Regional Experiment (SURE) Design Project, a regional transport model of atmospheric sulfates has been developed. This quasi-Lagrangian three-dimensional grid numerical model uses a detailed SO 2 emission inventory of major anthropogenic sources in the Eastern U.S. region, and observed meteorological data during an episode as inputs. The model accounts for advective transport and turbulent diffusion of the pollutants. The chemical transformation of SO 2 and SO 4 /sup =/ and the deposition of the species at the earth's surface are assumed to be linear processes at specified constant rates. The numerical model can predict the daily average concentrations of SO 2 and SO 4 /sup =/ at all receptor locations in the grid region during the episode. Because of the spatial resolution of the grid, this model is particularly suited to investigate the effect of tall stacks in reducing the ambient concentration levels of sulfur pollutants. This paper presents the formulations and assumptions of the regional sulfate transport model. The model inputs and results are discussed. Isopleths of predicted SO 2 and SO 4 /sup =/ concentrations are compared with the observed ground level values. The bulk of the information in this paper is directed to air pollution meteorologists and environmental engineers interested in the atmospheric transport modeling studies of sulfur oxide pollutants

  7. Effects of magnesium sulfate on the foliar absorption of phosphates at the pumpkin; Effets du sulfate de magnesium sur l'absorption foliaire de phosphates chez le potiron

    Chamel, A

    1962-07-01

    The foliar absorption of phosphates labelled with {sup 32}P and applied with or without magnesium sulfate on the first leaf of pumpkin seedlings have been studied. The magnesium sulfate applied with the phosphate reduces plainly the absorption rate of {sup 32}P. (O.M.) [French] Nous avons etudie l'absorption foliaire de phosphates marques au {sup 32}P appliques, avec et sans sulfate de magnesium, sur la premiere feuille de jeunes plants de potirons. Le sulfate de magnesium applique avec le phosphate diminue nettement le taux d'absorption du {sup 32}P. (auteur)

  8. A novel chondroitin sulfate hydrogel for nerve repair

    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.

  9. Evolutionary relationships and functional diversity of plant sulfate transporters.

    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.

  10. Equivalence of a single dose (1200 mg) compared to a three-time a day dose (400 mg) of chondroitin 4&6 sulfate in patients with knee osteoarthritis. Results of a randomized double blind placebo controlled study.

    Zegels, B; Crozes, P; Uebelhart, D; Bruyère, O; Reginster, J Y

    2013-01-01

    Evaluation of the efficacy and safety of a single oral dose of a 1200 mg sachet of chondroitin 4&6 sulfate (CS 1200) vs three daily capsules of chondroitin 4&6 sulfate 400 mg (CS 3*400) (equivalence study) and vs placebo (superiority study) during 3 months, in patients with knee osteoarthritis (OA). Comparative, double-blind, randomized, multicenter study, including 353 patients of both genders over 45 years with knee OA. Minimum inclusion criteria were a Lequesne index (LI) ≥ 7 and pain ≥ 40 mm on a visual analogue scale (VAS). LI and VAS were assessed at baseline and after 1-3 months. Equivalence between CS was tested using the per-protocol procedure and superiority of CS vs placebo was tested using an intent-to-treat procedure. After 3 months of follow-up, no significant difference was demonstrated between the oral daily single dose of CS 1200 formulation and the three daily capsules of CS 400. Patients treated with CS 1200 or CS 3*400 were significantly improved compared to placebo after 3 months of follow-up in terms of LI (security and tolerability was observed between the three groups. This study suggests that a daily administration of an oral sachet of 1200 mg of chondroitin 4&6 sulfate allows a significant clinical improvement compared to a placebo, and a similar improvement when compared to a regimen of three daily capsules of 400 mg of the same active ingredient. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

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

    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.

  12. Sulfated glycosaminoglycans in human vocal fold lamina propria

    Sung Woo Park

    Full Text Available Abstract Introduction: The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear. Objective: To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age. Methods: We used 11 vocal folds obtained from cadavers (7 men and 4 women with no laryngeal lesion, less than 12 h after death, and aged between 35 and 98 years. The folds underwent glycosaminoglycans extraction from the cover and ligament, and post-electrophoresis analysis. Data were compared according to the layer, age and gender. Results: The concentration of dermatan sulfate was significantly higher in all layers. No differences were observed in the total concentrations of glycosaminoglycans in layers studied according to gender. It is significantly lower in the cover of individuals aged below 60 years. Conclusion: Dermatan sulfate, chondroitin sulfate, and heparan sulfate were observed in the human vocal folds cover and ligament of both genders, with the concentration of dermatan sulfate being significantly higher in all layers. Glycosaminoglycans concentration on the cover is significantly lower in individuals below 60 years compared with elderly.

  13. Sulfate transport in toad skin

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting...... apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage...... conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short...

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

    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

  15. Sulfate resistance of nanosilica contained Portland cement mortars

    Batilov, Iani B.

    Soils, sea water and ground water high in sulfates are commonly encountered hostile environments that can attack the structure of concrete via chemical and physical mechanisms which can lead to costly repairs or replacement. Sulfate attack is a slow acting deteriorative phenomenon that can result in cracking, spalling, expansion, increased permeability, paste-to-aggregate bond loss, paste softening, strength loss, and ultimately, progressive failure of concrete. In the presented research study, Portland cement (PC) mortars containing 1.5% to 6.0% nanosilica (nS) cement replacement by weight were tested for sulfate resistance through full submersion in sodium sulfate to simulate external sulfate attack. Mortars with comparable levels of cement replacement were also prepared with microsilica (mS). Three cement types were chosen to explore nS' effectiveness to reduce sulfate expansion, when paired with cements of varying tricalcium aluminate (C3A) content and Blaine fineness, and compare it to that of mS. Mortars were also made with combined cement replacement of equal parts nS and mS to identify if they were mutually compatible and beneficial towards sulfate resistance. Besides sulfate attack expansion of mortar bars, the testing program included investigations into transport and microstructure properties via water absorption, sulfate ion permeability, porosimetry, SEM with EDS, laser diffraction, compressive strength, and heat of hydration. Expansion measurements indicated that mS replacement mortars outperformed both powder form nS, and nS/mS combined replacement mixtures. A negative effect of the dry nS powder replacement attributed to agglomeration of its nanoparticles during mixing negated the expected superior filler, paste densification, and pozzolanic activity of the nanomaterial. Agglomerated nS was identified as the root cause behind poor performance of nS in comparison to mS for all cement types, and the control when paired with a low C3A sulfate resistant

  16. AC impedance spectroscopy study of the corrosion behavior of an AZ91 magnesium alloy in 0.1 M sodium sulfate solution

    Chen, Jian; Wang, Jianqiu; Han, Enhou; Dong, Junhua; Ke, Wei

    2007-01-01

    The corrosion behavior of an AZ91 magnesium alloy in 0.1 M sodium sulfate solution at the corrosion potential (E corr ) was investigated using electrochemical impedance spectroscopy (EIS), environmental scanning electron microscopy (ESEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results showed that when the immersion time was less than 18th, general corrosion occurred on the surface and the main corrosion products were hydroxides and sulfates. The film coverage effect was the main mechanism for the corrosion process of AZ91 alloy. At this stage, the matrix had a better corrosion resistance. With the increasing immersion time, pitting occurred on the surface. At this stage, the corrosion process was controlled by three surface state variables: the area fraction θ 1 of the region controlled by the formation of Mg(OH) 2 , the area fraction θ 2 of the region controlled by the precipitation of MgAl 2 (SO 4 ) 4 .2H 2 O, and the metastable Mg + concentration C m

  17. NMR studies of the influence of dodecyl sulfate on the amide hydrogen exchange kinetics of a micelle-solubilized hydrophobic tripeptide

    O'Neil, J.D.J.; Sykes, B.D.

    1989-01-01

    Backbone amide hydrogen exchange measurements are an important source of information about the internal dynamics of proteins. Before such measurements can be interpreted unambiguously, contributions to hydrogen exchange rates from the chemical and physical environment of the amides must be taken into account. Membrane proteins are often solubilized in detergents, yet there have not been any systematic investigations of the possible effects detergents may have on the amide hydrogen exchange rates of proteins. To address this question, the authors have measured individual backbone and carboxyl-terminal amide exchange rates for the amphipathic tripeptide Leu-Val-Ile-amide dissolved in water and dodecyl sulfate micelles. Proton NMR spectroscopy was used to measure exchange using the direct exchange-out into D 2 O technique at 5 degree C and using an indirect steady-state saturation-transfer technique at 25 degree C. The broadening effect of micelle-incorporated spin-labeled fatty acid (12-doxylsterate) on the 1 H NMR spectra of both the detergent and the peptide resonances was used to demonstrate that the tripeptide is intimately associated with the micelle. These experiments help to explain the elevated pH min observed for backbone amides in the sodium dodecyl sulfate solubilized M13 coat protein

  18. A spectroscopic and surface microhardness study of enamel exposed to beverages supplemented with ferrous fumarate and ferrous sulfate. A randomized in vitro trial.

    Xavier, Arun M; Rai, Kavita; Hegde, Amitha M; Shetty, Suchetha

    2016-06-01

    To compare the efficacy between supplementing ferrous fumarate and ferrous sulfate to carbonated beverages by recording the in vitro mineral loss and surface microhardness (SMH) changes in human enamel. 120 enamel blocks each (from primary and permanent teeth) were uniformly prepared and the initial SMH was recorded. These enamel specimens were equally divided (n = 60) for their respective beverage treatment in Group 1 (2 mmol/L ferrous sulfate) and Group 2 (2 mmol/L ferrous fumarate). Each group was further divided into three subgroups as Coca-Cola, Sprite and mineral water (n= 10). The specimens were subjected to three repetitive cycles of respective treatment for a 5-minute incubation period, equally interspaced by 5-minute storage in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH recorded. The results were tested using student's t-test, one-way ANOVA and Wilcoxon signed rank test (P Coca-Cola (P < 0.005).

  19. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

    Restaino, Odile Francesca, E-mail: odilefrancesca.restaino@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Finamore, Rosario, E-mail: rosario.finamore@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Diana, Paola, E-mail: paola.diana@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Marseglia, Mariacarmela, E-mail: marimars84@hotmail.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Vitiello, Mario, E-mail: mariovitiello.ita@gmail.com [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Casillo, Angela, E-mail: angela.casillo@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Bedini, Emiliano, E-mail: emiliano.bedini@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Parrilli, Michelangelo, E-mail: michelangelo.parrilli@unina.it [Department of Biology, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); and others

    2017-03-15

    contamination in chondoitin sulfate samples. • A new HPAED method was developed, compared to a GC-MS one and used to screen standard and commercial samples. • Keratan sulfate contamination was found in the range from 0.1 to 19%, in almost 50% of the samples tested it was over the 5% limit. • First time detected keratan sulfate contamination in both bovine and marine origin standards. • SEC-TDA analyses, SAX chromatography and NMR studies allowed to detect in chondrotin sulfate samples the presence of low sulfated chains and proteoglycan bounded ones.

  20. A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

    Restaino, Odile Francesca; Finamore, Rosario; Diana, Paola; Marseglia, Mariacarmela; Vitiello, Mario; Casillo, Angela; Bedini, Emiliano; Parrilli, Michelangelo

    2017-01-01

    contamination in chondoitin sulfate samples. • A new HPAED method was developed, compared to a GC-MS one and used to screen standard and commercial samples. • Keratan sulfate contamination was found in the range from 0.1 to 19%, in almost 50% of the samples tested it was over the 5% limit. • First time detected keratan sulfate contamination in both bovine and marine origin standards. • SEC-TDA analyses, SAX chromatography and NMR studies allowed to detect in chondrotin sulfate samples the presence of low sulfated chains and proteoglycan bounded ones.

  1. 21 CFR 184.1261 - Copper sulfate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food and... Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4·5H2O, CAS... the reaction of sulfuric acid with cupric oxide or with copper metal. (b) The ingredient must be of a...

  2. Periodate Oxidation for Sulfated Glycosaminoglycans, with Special Reference to the Position of Extra Sulfate Groups in Chondroitin Polysulfates, Chondroitin Sulfate D and Chondroitin Sulfate K

    Seno, Nobuko; Murakami, Keiko; Shibusawa, Haru

    1981-01-01

    The optimum conditions for periodate oxidation of sulfated disaccharides were investigated to determine the position of extra sulfate groups on the saturated disulfated disaccharides obtained from chondroitin polysulfates, chondroitin sulfates D and K. Under the conditions: 2mM saturated disulfated disaccharide with 20mM sodium periodate at 37°in the dark, the uronic acid residue in the disulfated disaccharide from chondroitin sulfate D was rapidly and completely destroyed, whereas that in th...

  3. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    Kirchheim, A. P.

    2011-02-21

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C3A or 3CaO·Al2O 3) and Na-doped tricalcium aluminate (orthorhombic C3A or Na2Ca8Al6O18), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by 27Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C3A hydration during the early stages. There are differences in the hydration mechanism between the two types of C3A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C3A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C3A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping. © 2011 American Chemical Society.

  4. 21 CFR 582.5230 - Calcium sulfate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  5. 21 CFR 184.1643 - Potassium sulfate.

    2010-04-01

    ... hydroxide or potassium carbonate. (b) The ingredient meets the specifications of the “Food Chemicals Codex... 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...

  6. 21 CFR 184.1443 - Magnesium sulfate.

    2010-04-01

    ... 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... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization...

  7. EFFECT OF MAGNESIUM SULFATE (A LAXATIVE) ON ...

    use with little success . Magnesium sulfate also known as Epsom salt or bitter salt is a hydrate salt with a chemical name of magnesium sulfate heptahydrate . Chemical formula is MgSO. 7HO and trade name is. Andrews liver salt. Dried magnesium sulfate is an osmotic laxative or a saline laxative that acts by increasing the.

  8. 21 CFR 582.5443 - Magnesium sulfate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  9. Modeling and minimization of barium sulfate scale

    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...

  10. 21 CFR 582.1125 - Aluminum sulfate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 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 182.1125 - Aluminum sulfate.

    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...

  12. Tratamento da Eclâmpsia: Estudo Comparativo entre o Sulfato de Magnésio e a Fenitoína Treatment of Eclampsia: Comparative Study on the Use of Magnesium Sulfate and Phenytoin

    João de Deus Valadares Neto

    2000-10-01

    Full Text Available Objetivos: comparar a eficácia do sulfato de magnésio e da fenitoína no controle das convulsões em pacientes com eclâmpsia e avaliar os efeitos de sulfato de magnésio e da fenitoína sobre o prognóstico materno e perinatal em pacientes com eclâmpsia. Métodos: estudo prospectivo, randômico e controlado no qual foram analisados, de forma comparativa, os resultados obtidos no tratamento anticonvulsivante da eclâmpsia em 77 mulheres tratadas com sulfato de magnésio ou fenitoína. As drogas que constituíram os dois esquemas terapêuticos foram distribuídas, na proporção de um para um, em caixas numeradas aleatoriamente que apresentavam características semelhantes. À medida que cada paciente era admitida, uma caixa era aberta e o esquema nela contido administrado à paciente. Resultados: observou-se que, no grupo tratado com sulfato de magnésio, 19,5% das pacientes apresentaram recidiva de convulsões, ao passo que no grupo que usou fenitoína, 36,1% manifestaram novas crises (p0,05. Conclusões: o sulfato de magnésio mostrou-se mais eficaz que a fenitoína no controle e prevenção da recidiva de convulsões em pacientes com eclâmpsia, embora sua utilização esteja associada a maior prevalência materna de hemorragia pós-parto e desconforto respiratório neonatal. A fenitoína apresenta-se como droga alternativa para o tratamento de eclâmpsia nos casos em que houver contra-indicação ao uso do sulfato de magnésio.Purpose: to compare the efficiency between magnesium sulfate and phenytoin in the control of convulsions in patients with eclampsia and to evaluate the effects of magnesium sulfate and phenytoin on the maternal and perinatal prognosis in patients with eclampsia. Methods: this is a prospective, randomized and controlled study in which the results obtained with the use of anticonvulsive treatment in 77 women with eclampsia, treated with either magnesium sulfate or phenytoin, were analyzed comparatively. The drugs

  13. Short communication: Efficacy of copper sulfate hoof baths against digital dermatitis--Where is the evidence?

    Thomsen, Peter T

    2015-04-01

    Digital dermatitis is a major problem in modern dairy production because of decreased animal welfare and financial losses. Individual cow treatments are often seen as too time consuming by farmers, and walk-through hoof baths have therefore been used extensively to control digital dermatitis. For decades, copper sulfate hoof baths have been used to treat and prevent digital dermatitis. Copper sulfate has been referred to as the industry gold standard when it comes to hoof-bath chemicals. In several scientific studies testing the efficacy of other hoof-care products, copper sulfate has been used as a positive control, thereby indicating that copper sulfate has a known positive effect. However, this may not be the case. A dilemma may exist between (1) copper sulfate generally being perceived as being effective against digital dermatitis and (2) a possible lack of well-documented scientific evidence of this effect. The objective of this study was to evaluate the existing scientific literature to determine whether the efficacy of copper sulfate used in hoof baths against digital dermatitis has in fact been demonstrated scientifically. A systematic literature search identified 7 peer-reviewed journal articles describing the efficacy of copper sulfate in hoof baths as treatment or prevention of bovine digital dermatitis. Only 2 of the 7 studies compared copper sulfate to a negative control; most studies were relatively small, and often no clear positive effect of copper sulfate was demonstrated. In conclusion, the frequent claim that copper sulfate is widely reported to be effective is supported by little scientific evidence. Well-designed clinical trials evaluating the effect of copper sulfate against digital dermatitis compared with a negative control are needed. Until such studies have been made, the efficacy of copper sulfate in hoof baths against digital dermatitis remains largely unproven. Copyright © 2015 American Dairy Science Association. Published by Elsevier

  14. Regeneration of sulfated metal oxides and carbonates

    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.

  15. Conformational studies of human [15-2-aminohexanoic acid]little gastrin in sodium dodecyl sulfate micelles by 1H NMR

    Mammi, S.; Peggion, E.

    1990-01-01

    Human little gastrin is a 17 amino acid peptide that adopts a random conformation in water and an ordered structure in sodium dodecyl sulfate (SDS) micelles as well as in trifluoroethanol (TFE). The circular dichroism spectra in these two media have the same shape, indicative of a similar preferred conformation. The authors describe here the assignment of the proton NMR resonances and the conformational analysis of [Ahx 15 ] little gastrin in SDS micelles. Two-dimensional correlation techniques form the basis for the assignment. The conformational analysis utilizes NOE's, NH to C α H coupling constants, and the temperature coefficients of the amide chemical shifts. The NMR data indicate a helical structure in the N-terminal portion of the peptide. These results are compared with the conformation that the authors recently proposed for a minigastrin analogue (fragment 5-17 of [Ahx 15 ] little gastrin) in TFE

  16. Podocyte-specific deletion of NDST1, a key enzyme in the sulfation of heparan sulfate glycosaminoglycans, leads to abnormalities in podocyte organization in vivo

    Sugar, T.; Wassenhove-McCarthy, D.J.; Esko, J.D.; Kuppevelt, T.H. van; Holzman, L.; McCarthy, K.J.

    2014-01-01

    Heparan sulfate proteoglycans have been shown to modulate podocyte adhesion to--and pedicel organization on--the glomerular basement membrane. Recent studies showed that foot process effacement developed in a mutant mouse model whose podocytes were unable to assemble heparan sulfate

  17. Sulfation of Condensed Potassium Chloride by SO2

    Sengeløv, Louise With; Hansen, Troels Bruun; Bartolomé, Carmen

    2013-01-01

    The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K and with rea......The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K...... and with reactant concentrations of 500–3000 ppm SO2, 1–20% O2, and 4–15% H2O. The degree of sulfation was monitored by measuring the formation of HCl. Analysis of the solid residue confirmed that the reaction proceeds according to a shrinking core model and showed the formation of an eutectic at higher...... temperatures. On the basis of the experimental results, a rate expression for the sulfation reaction was derived. The model compared well with literature data for sulfation of KCl and NaCl, and the results indicate that it may be applied at even higher SO2 concentrations and temperatures than those...

  18. Radiocrystallography study of the wolfeite of pegmatite from Bela Vista, Minas Gerais State in Brazil

    Baptista, N.R.; Baptista, A.

    1985-01-01

    The conclusions about the wolfeite mineral monocrystal study (Fe,Mn) 2 (PO 4 ) (OH), from the Bela Vista pigmatite, Minas Gerais State were described. Reticular Parameters were determined and through the reflection levels analysis the space group was confirmed. (L.M.J.) [pt

  19. Radiocrystallographic study of the triphylite of pegmatite from Bela Vista, Minas Gerais State, in Brazil

    Baptista, N.R.; Baptista, A.

    1985-01-01

    Conclusions through the triphylite mineral monocrystal Li (Fe,Mn)PO4 study from Bela Vista pegmatite, Minas Gerais State were related. Reticular parameters were evaluated and through the reflection levels analysis present in the different reciprocal levels photographyed, a space group mentioned in literature were confirmed. (L.M.J.) [pt

  20. Structure-Activity Relationships of Bioengineered Heparin/Heparan Sulfates Produced in Different Bioreactors

    Ha Na Kim

    2017-05-01

    Full Text Available Heparin and heparan sulfate are structurally-related carbohydrates with therapeutic applications in anticoagulation, drug delivery, and regenerative medicine. This study explored the effect of different bioreactor conditions on the production of heparin/heparan sulfate chains via the recombinant expression of serglycin in mammalian cells. Tissue culture flasks and continuously-stirred tank reactors promoted the production of serglycin decorated with heparin/heparan sulfate, as well as chondroitin sulfate, while the serglycin secreted by cells in the tissue culture flasks produced more highly-sulfated heparin/heparan sulfate chains. The serglycin produced in tissue culture flasks was effective in binding and signaling fibroblast growth factor 2, indicating the utility of this molecule in drug delivery and regenerative medicine applications in addition to its well-known anticoagulant activity.

  1. Potential for beneficial application of sulfate reducing bacteria in sulfate containing domestic wastewater treatment.

    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.

  2. Hydrazine Sulfate (PDQ)

    ... NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent ... NCCIH) are sponsoring a number of clinical trials (research studies) at medical centers to test CAM therapies for use in cancer. Conventional approaches to cancer ...

  3. Analysis of Saprolegnia parasitica Transcriptome following Treatment with Copper Sulfate.

    Kun Hu

    Full Text Available Massive infection caused by oomycete fungus Saprolegnia parasitica is detrimental to freshwater fish. Recently, we showed that copper sulfate demonstrated good efficacy for controlling S. parasitica infection in grass carp. In this study, we investigated the mechanism of inhibition of S. parasitica growth by copper sulfate by analyzing the transcriptome of copper sulfate-treated S. parasitica. To examine the mechanism of copper sulfate inhibiting S. parasitica, we utilized RNA-seq technology to compare differential gene expression in S. parasitica treated with or without copper sulfate.The total mapped rates of the reads with the reference genome were 90.50% in the control group and 73.50% in the experimental group. In the control group, annotated splice junctions, partial novel splice junctions and complete novel splice junctions were about 83%, 3% and 14%, respectively. In the treatment group, the corresponding values were about 75%, 6% and 19%. Following copper sulfate treatment, a total 310 genes were markedly upregulated and 556 genes were markedly downregulated in S. parasitica. Material metabolism related GO terms including cofactor binding (33 genes, 1,3-beta-D-glucan synthase complex (4 genes, carboxylic acid metabolic process (40 genes were the most significantly enriched. KEGG pathway analysis also determined that the metabolism-related biological pathways were significantly enriched, including the metabolic pathways (98 genes, biosynthesis of secondary metabolites pathways (42 genes, fatty acid metabolism (13 genes, phenylalanine metabolism (7 genes, starch and sucrose metabolism pathway (12 genes. The qRT-PCR results were largely consistent with the RNA-Seq results.Our results indicate that copper sulfate inhibits S. parasitica growth by affecting multiple biological functions, including protein synthesis, energy biogenesis, and metabolism.

  4. Behaviour of cementitious materials: sulfates and temperature actions

    Barbarulo, Remi

    2002-09-01

    The research work presented in this Ph.D. thesis is related to the nuclear waste underground repository concept. Concrete could be used in such a repository, and would be subjected to variations of temperature in presence of sulfate, a situation that could induce expansion of concrete. The research was lead in three parts: an experimental study of the possibility of an internal sulfate attack on mortars; an experimental study and modeling of the chemical equilibriums of the CaO-SiO 2 -Al 2 O 3 -SO 3 -H 2 O system; and a modeling of the mechanisms of internal and external sulfate attacks, and the effect of temperature. The results show that mortars can develop expansions after a steam-cure during hydration, but also when a long steam-cure is applied to one-year-old mortars, which is a new point. Ettringite precipitation can be considered as responsible for these expansions. The experimental study of the CaO-SiO 2 -Al 2 O 3 -SO 3 -H 2 O system clarified the role of Calcium Silicate Hydrates (C-S-H) on chemical equilibriums of cementitious materials. Sulfate sorption on C-S-H has been studied in detail. The quantity of sulfate bound to the C-S-H mainly depends on the sulfate concentration in solution, on the Ca/Si ratio of the C-S-H and is not significantly influenced by temperature. Aluminium inclusion in the C-S-H seems to be a significant phenomenon. Temperature increases the calcium sulfo-aluminate solubilities and thus increases sulfates concentration in solution. A modeling of the chemical system is proposed. Simulations of external sulfate attack (15 mmol/L of Na 2 SO 4 ) predict ettringite precipitation at 20 and 85±C. Simulation of internal sulfate attack was performed at a local scale (a hydrated cement grain). An initial inhomogeneity can lead, after a thermal curing at 85±C, to ettringite precipitation in zones originally free from ettringite. This new-formed ettringite could be the origin of the expansions. (author) [fr

  5. Synthesis of [2,4-3H] 17β-dihydroequilin sulfate

    Bhavnani, B.R.

    1994-01-01

    [2,4- 3 H] 17β-dihydroequilin-3-sulfate ammonium salt suitable for in vivo pharmacokinetic studies was synthesized from [2,4- 3 H] equilin. Sulfation of [2,4- 3 H] equilin with pyridine-chlorosulfonic acid mixture gave in high yields [2,4- 3 H] equilin sulfate, which was then reduced with sodium borohydride to yield [2,4- 3 H] 17β-dihydroequilin sulfate. The reduction was sterospecific and no 17α-reduced products were formed. (author)

  6. Role of protein sulfation in vasodilation induced by minoxidil sulfate, a K+ channel opener

    Meisheri, K.D.; Oleynek, J.J.; Puddington, L.

    1991-01-01

    Evidence from contractile, radioisotope ion flux and electrophysiological studies suggest that minoxidil sulfate (MNXS) acts as a K+ channel opener in vascular smooth muscle. This study was designed to examine possible biochemical mechanisms by which MNXS exerts such an effect. Experiments performed in the isolated rabbit mesenteric artery (RMA) showed that MNXS, 5 microM, but not the parent compound minoxidil, was a potent vasodilator. Whereas the relaxant effects of an another K+ channel opener vasodilator, BRL-34915 (cromakalim), were removed by washing with physiological saline solution, the effects of MNXS persisted after repeated washout attempts. Furthermore, after an initial exposure of segments of intact RMA to [35S] MNXS, greater than 30% of the radiolabel was retained 2 hr after removal of the drug. In contrast, retention of radiolabel was not detected with either [3H]MNXS (label on the piperidine ring of MNXS) or [3H]minoxidil (each less than 3% after a 2-hr washout). These data suggested that the sulfate moiety from MNXS was closely associated with the vascular tissue. To determine if proteins were the acceptors of sulfate from MNXS, intact RMAs were incubated with [35S]MNXS, and then 35S-labeled proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analyzed by fluorography. Preferential labeling of a 116 kD protein was detected by 2 and 5 min of treatment. A 43 kD protein (resembling actin) also showed significant labeling. A similar profile of 35S-labeled proteins was observed in [35S] MNXS-treated A7r5 rat aortic smooth muscle cells, suggesting that the majority of proteins labeled by [35S]MNXS in intact RMA were components of smooth muscle cells

  7. Antifouling potential of Nature-inspired sulfated compounds

    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 ( 1000 μg.mL-1). This study put forward the relevance of synthesizing non-natural sulfated small molecules to generate new nontoxic antifouling agents.

  8. Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

    Harmon, S.M.

    2003-01-01

    In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

  9. A comparison of stable-isotope probing of DNA and phospholipid fatty acids to study prokaryotic functional diversity in sulfate-reducing marine sediment enrichment slurries.

    Webster, Gordon; Watt, Lynsey C; Rinna, Joachim; Fry, John C; Evershed, Richard P; Parkes, R John; Weightman, Andrew J

    2006-09-01

    Marine sediment slurries enriched for anaerobic, sulfate-reducing prokaryotic communities utilizing glucose and acetate were used to provide the first comparison between stable-isotope probing (SIP) of phospholipid fatty acids (PLFA) and DNA (16S rRNA and dsrA genes) biomarkers. Different 13C-labelled substrates (glucose, acetate and pyruvate) at low concentrations (100 microM) were used over a 7-day incubation to follow and identify carbon flow into different members of the community. Limited changes in total PLFA and bacterial 16S rRNA gene DGGE profiles over 7 days suggested the presence of a stable bacterial community. A broad range of PLFA were rapidly labelled (within 12 h) in the 13C-glucose slurry but this changed with time, suggesting the presence of an active glucose-utilizing population and later development of another population able to utilize glucose metabolites. The identity of the major glucose-utilizers was unclear as 13C-enriched PLFA were common (16:0, 16:1, 18:1omega7, highest incorporation) and there was little difference between 12C- and 13C-DNA 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) profiles. Seemingly glucose, a readily utilizable substrate, resulted in widespread incorporation consistent with the higher extent of 13C-incorporation (approximately 10 times) into PLFA compared with 13C-acetate or 13C-pyruvate. 13C-PLFA in the 13C-acetate and 13C-pyruvate slurries were similar to each other and to those that developed in the 13C-glucose slurry after 4 days. These were more diagnostic, with branched odd-chain fatty acids (i15:0, a15:0 and 15:1omega6) possibly indicating the presence of Desulfococcus or Desulfosarcina sulfate-reducing bacteria (SRB) and sequences related to these SRB were in the 13C-acetate-DNA dsrA gene library. The 13C-acetate-DNA 16S rRNA gene library also contained sequences closely related to SRB, but these were the acetate-utilizing Desulfobacter sp., as well as a broad range of uncultured Bacteria. In

  10. Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

    Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

    2017-03-01

    Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at

  11. Biological sulfate removal from construction and demolition debris leachate: Effect of bioreactor configuration

    Kijjanapanich, Pimluck; Do, Anh Tien; Annachhatre, Ajit P.; Esposito, Giovanni; Yeh, Daniel H.; Lens, Piet N.L.

    2014-01-01

    Highlights: • Novel biological technique for gypsum removal from CDD. • CDDS leachate treatment performed using different sulfate reducing bioreactors. • Gypsum in CDD can be used as a source of sulfate for sulfate reducing bacteria. • High calcium concentration (1000 mg L −1 ) did not affect the bioreactor performance. - Abstract: Due to the contamination of construction and demolition debris (CDD) by gypsum drywall, especially, its sand fraction (CDD sand, CDDS), the sulfate content in CDDS exceeds the posed limit of the maximum amount of sulfate present in building sand (1.73 g sulfate per kg of sand for the Netherlands). Therefore, the CDDS cannot be reused for construction. The CDDS has to be washed in order to remove most of the impurities and to obtain the right sulfate content, thus generating a leachate, containing high sulfate and calcium concentrations. This study aimed at developing a biological sulfate reduction system for CDDS leachate treatment and compared three different reactor configurations for the sulfate reduction step: the upflow anaerobic sludge blanket (UASB) reactor, inverse fluidized bed (IFB) reactor and gas lift anaerobic membrane bioreactor (GL-AnMBR). This investigation demonstrated that all three systems can be applied for the treatment of CDDS leachate. The highest sulfate removal efficiency of 75–85% was achieved at a hydraulic retention time (HRT) of 15.5 h. A high calcium concentration up to 1000 mg L −1 did not give any adverse effect on the sulfate removal efficiency of the IFB and GL-AnMBR systems

  12. Biological sulfate removal from construction and demolition debris leachate: Effect of bioreactor configuration

    Kijjanapanich, Pimluck, E-mail: som_cheng00@hotmail.com [Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Do, Anh Tien [Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Annachhatre, Ajit P. [Environmental Engineering and Management, Asian Institute of Technology, PO Box 4, Klongluang, Pathumthani 12120 (Thailand); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino (Italy); Yeh, Daniel H. [Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Lens, Piet N.L. [Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands)

    2014-03-01

    Highlights: • Novel biological technique for gypsum removal from CDD. • CDDS leachate treatment performed using different sulfate reducing bioreactors. • Gypsum in CDD can be used as a source of sulfate for sulfate reducing bacteria. • High calcium concentration (1000 mg L{sup −1}) did not affect the bioreactor performance. - Abstract: Due to the contamination of construction and demolition debris (CDD) by gypsum drywall, especially, its sand fraction (CDD sand, CDDS), the sulfate content in CDDS exceeds the posed limit of the maximum amount of sulfate present in building sand (1.73 g sulfate per kg of sand for the Netherlands). Therefore, the CDDS cannot be reused for construction. The CDDS has to be washed in order to remove most of the impurities and to obtain the right sulfate content, thus generating a leachate, containing high sulfate and calcium concentrations. This study aimed at developing a biological sulfate reduction system for CDDS leachate treatment and compared three different reactor configurations for the sulfate reduction step: the upflow anaerobic sludge blanket (UASB) reactor, inverse fluidized bed (IFB) reactor and gas lift anaerobic membrane bioreactor (GL-AnMBR). This investigation demonstrated that all three systems can be applied for the treatment of CDDS leachate. The highest sulfate removal efficiency of 75–85% was achieved at a hydraulic retention time (HRT) of 15.5 h. A high calcium concentration up to 1000 mg L{sup −1} did not give any adverse effect on the sulfate removal efficiency of the IFB and GL-AnMBR systems.

  13. Kinetics of the direct sulfation of limestone at the initial stage of crystal growth of the solid product

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2011-01-01

    The direct sulfation of limestone was studied in a quartz bench scale fixed‐bed reactor with the technique of data deconvolution. The obtained results show that the direct sulfation of limestone has a two‐period kinetic behavior: a short initial sulfation period with high but fast decreasing...... such as SO2, O2, and CO2 and the temperature. The sulfation process in the initial stage of the period with product crystal growth can be described by the combination of the sulfation reaction at the gas–solid interface, diffusion of the product ions toward the product crystal grains, diffusion of carbonate...

  14. Inhibition of synthesis of heparan sulfate by selenate: Possible dependence on sulfation for chain polymerization

    Dietrich, C.P.; Nader, H.B.; Buonassisi, V.; Colburn, P.

    1988-01-01

    Selenate, a sulfation inhibitor, blocks the synthesis of heparan sulfate and chondroitin sulfate by cultured endothelial cells. In contrast, selenate does not affect the production of hyaluronic acid, a nonsulfated glycosaminoglycan. No differences in molecular weight, [ 3 H]glucosamine/[ 35 S]sulfuric acid ratios, or disaccharide composition were observed when the heparan sulfate synthesized by selenate-treated cells was compared with that of control cells. The absence of undersulfated chains in preparations from cultures exposed to selenate supports the concept that, in the intact cell, the polymerization of heparan sulfate might be dependent on the sulfation of the saccharide units added to the growing glycosaminoglycan chain

  15. Sulfate and dissolved sulfide variation under low COD/Sulfate ratio in Up-flow Anaerobic Sludge Blanket (UASB treating domestic wastewater

    Sérvio Túlio Alves Cassini

    2012-04-01

    Full Text Available In this study, the dynamics of sulfate reduction and dissolved sulfide generation (S2-, HS-, H2Saq in liquid phase was evaluated in an UASB reactor treating domestic wastewater with low COD/Sulfate content. The evaluation in the UASB reactor was performed at three sludge heights (0.25, 1.25, 2.25 taps and effluent of the reactor. Sulfate reduction was verified in the reactor, with an average reduction of 24 % throughout the experiment period. However, the dissolved sulfide concentration in the reactor was not higher than 5.0 mg Sdiss/L. The kinetic model of first order showed good fit to describe the sulfate reduction under different COD/sulfate ratio, with K1app between 2.94x10-5 s-1 and 1.17x10-5 s-1 with correlation coefficients for data over 91%. The maximum rate to sulfate reduction was 18.0 mg SO42-/L.h-1 and small variation in COD/sulfate ratio promotes a significant change both in sulfate and sulfide concentrations.

  16. Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

    Kravitz, Ben

    2009-07-28

    We used a general circulation model of Earth\\'s climate to conduct geoengineering experiments involving stratospheric injection of sulfur dioxide and analyzed the resulting deposition of sulfate. When sulfur dioxide is injected into the tropical or Arctic stratosphere, the main additional surface deposition of sulfate occurs in midlatitude bands, because of strong cross-tropopause flux in the jet stream regions. We used critical load studies to determine the effects of this increase in sulfate deposition on terrestrial ecosystems by assuming the upper limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2 into the tropical stratosphere or 3 Tg of SO2 into the Arctic stratosphere, neither the maximum point value of sulfate deposition of approximately 1.5 mEq m−2 a−1 nor the largest additional deposition that would result from geoengineering of approximately 0.05 mEq m−2 a−1 is enough to negatively impact most ecosystems.

  17. Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

    Kravitz, Ben; Robock, Alan; Oman, Luke; Stenchikov, Georgiy L.; Marquardt, Allison B.

    2009-01-01

    We used a general circulation model of Earth's climate to conduct geoengineering experiments involving stratospheric injection of sulfur dioxide and analyzed the resulting deposition of sulfate. When sulfur dioxide is injected into the tropical or Arctic stratosphere, the main additional surface deposition of sulfate occurs in midlatitude bands, because of strong cross-tropopause flux in the jet stream regions. We used critical load studies to determine the effects of this increase in sulfate deposition on terrestrial ecosystems by assuming the upper limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2 into the tropical stratosphere or 3 Tg of SO2 into the Arctic stratosphere, neither the maximum point value of sulfate deposition of approximately 1.5 mEq m−2 a−1 nor the largest additional deposition that would result from geoengineering of approximately 0.05 mEq m−2 a−1 is enough to negatively impact most ecosystems.

  18. Direct sulfation of limestone based on oxy-fuel combustion technology

    Chen, C.M.; Zhao, C.S.; Liu, S.T.; Wang, C.B. [North China Electric Power University, Baoding (China)

    2009-10-15

    With limestone as the sorbent, the sulfation reaction can proceed via two different routes depending on whether calcination of the limestone takes place under the given reaction conditions. The direct sulfation reaction is defined as the sulfation reaction between sulfur dioxide (SO{sub 2}) and limestone in an uncalcined state. This reaction, based on oxyfuel combustion technology, was studied by thermogravimetric analysis. Surface morphologies of the limestone particles after sulfation were examined by a scanning electron microscope. Results show that there are more pores or gaps in the product layer formed by direct sulfation of limestone than by indirect sulfation, which can be attributed to the generation of carbon dioxide (CO{sub 2}) at a reaction interface. Compared with indirect sulfation, direct sulfation of limestone can yield much higher conversion and has a much higher reaction rate. For direct sulfation, the greater porosity in the product layer greatly reduces the solid-state ion diffusion distance, resulting in a higher reaction rate and higher conversion.

  19. Biological sulfate removal from construction and demolition debris leachate: effect of bioreactor configuration.

    Kijjanapanich, Pimluck; Do, Anh Tien; Annachhatre, Ajit P; Esposito, Giovanni; Yeh, Daniel H; Lens, Piet N L

    2014-03-30

    Due to the contamination of construction and demolition debris (CDD) by gypsum drywall, especially, its sand fraction (CDD sand, CDDS), the sulfate content in CDDS exceeds the posed limit of the maximum amount of sulfate present in building sand (1.73 g sulfate per kg of sand for the Netherlands). Therefore, the CDDS cannot be reused for construction. The CDDS has to be washed in order to remove most of the impurities and to obtain the right sulfate content, thus generating a leachate, containing high sulfate and calcium concentrations. This study aimed at developing a biological sulfate reduction system for CDDS leachate treatment and compared three different reactor configurations for the sulfate reduction step: the upflow anaerobic sludge blanket (UASB) reactor, inverse fluidized bed (IFB) reactor and gas lift anaerobic membrane bioreactor (GL-AnMBR). This investigation demonstrated that all three systems can be applied for the treatment of CDDS leachate. The highest sulfate removal efficiency of 75-85% was achieved at a hydraulic retention time (HRT) of 15.5h. A high calcium concentration up to 1,000 mg L(-1) did not give any adverse effect on the sulfate removal efficiency of the IFB and GL-AnMBR systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Application of Biostimulation for Remediation of Sulfate-Contaminated Groundwater at a Mining Site

    Miao, Z.; Carroll, K. C.; Carreon, C.; Brusseau, M. L.

    2011-12-01

    There is growing concern regarding sulfate contamination of groundwater. One innovative in-situ remediation option under investigation is biostimulation through addition of electron-donor amendments to enhance sulfate reduction. Two pilot-scale ethanol-injection tests were conducted at a former uranium mining site that is contaminated with sulfate and nitrate (with a lack of heavy metals), and for which there appears to be minimal natural attenuation of sulfate. The first test was a push-pull test that had a limited zone of influence, while the second test was a single-well injection test in which additional downgradient wells were monitored. For both tests, sulfate concentrations began to decline within a few weeks of injection, after nitrate concentrations were significantly reduced. Concomitantly, aqueous concentrations of manganese, iron, and hydrogen sulfide increased from background. Monitoring over many months revealed that the declines in sulfate concentration conformed to exponential decay, with first-order decay rates of approximately 0.01 /d. Analysis of sulfur stable isotope data indicated that the decrease in sulfate concentrations was microbially mediated. The results also indicated that sulfides formed during sulfate reduction may have undergone partial re-oxidation. This study illustrates the feasibility of using ethanol injection for remediation of sulfate-contaminated groundwater. However, re-oxidation of sulfides (both metal sulfide precipitates and hydrogen sulfide gas) is a potential issue of significance that would need to be addressed.

  1. DETECTION AND PURIFICATION OF TYROSINE-SULFATED PROTEINS USING A NOVEL ANTI-SULFOTYROSINE MONOCLONAL ANTIBODY*

    Hoffhines, Adam J.; Damoc, Eugen; Bridges, Kristie G.; Leary, Julie A.; Moore, Kevin L.

    2006-01-01

    Protein-tyrosine O-sulfation is a post-translational modification mediated by one of two Golgi tyrosylprotein sulfotransferases (TPST-1 & TPST-2) that catalyze the transfer of sulfate to tyrosine residues in secreted and transmembrane proteins. Tyrosine sulfation plays a role in protein-protein interactions in several well-defined systems. Although dozens of tyrosine-sulfated proteins are known, many more are likely to exist and await description. Advancing our understanding of the importance of tyrosine sulfation in biological systems requires the development of new tools for the detection and study of tyrosine-sulfated proteins. We have developed a novel anti-sulfotyrosine monoclonal antibody, called PSG2, that binds with high affinity and exquisite specificity to sulfotyrosine residues in peptides and proteins independent of sequence context. We show that it can detect tyrosinesulfated proteins in complex biological samples and can be used as a probe to assess the role of tyrosine sulfation in protein function. We also demonstrate the utility of PSG2 in the purification of tyrosine-sulfated proteins from crude tissue samples. Finally, Western blot analysis using PSG2 indicates that certain sperm/epididymal proteins are undersulfated in Tpst2−/− mice. This indicates that TPST-1 and TPST-2 have distinct macromolecular substrate specificities and provides clues as to the molecular mechanism of the infertility of Tpst2−/− males. PSG2 should be widely applicable for identification of tyrosine-sulfated proteins in other systems and organisms. PMID:17046811

  2. Effects of bulk colloidal stability on adsorption layers of poly(diallyldimethylammonium chloride)/sodium dodecyl sulfate at the air-water interface studied by neutron reflectometry.

    Campbell, Richard A; Yanez Arteta, Marianna; Angus-Smyth, Anna; Nylander, Tommy; Varga, Imre

    2011-12-29

    We show for the oppositely charged system poly(diallyldimethylammonium chloride)/sodium dodecyl sulfate that the cliff edge peak in its surface tension isotherm results from the comprehensive precipitation of bulk complexes into sediment, leaving a supernatant that is virtually transparent and a depleted adsorption layer at the air/water interface. The aggregation and settling processes take about 3 days to reach completion and occur at bulk compositions around charge neutrality of the complexes which lack long-term colloidal stability. We demonstrate excellent quantitative agreement between the measured surface tension values and a peak calculated from the surface excess of surfactant in the precipitation region measured by neutron reflectometry, using the approximation that there is no polymer left in the liquid phase. The nonequilibrium nature of the system is emphasized by the production of very different interfacial properties from equivalent aged samples that are handled differently. We go on to outline our perspective on the "true equilibrium" state of this intriguing system and conclude with a comment on its practical relevance given that the interfacial properties can be so readily influenced by the handling of kinetically trapped bulk aggregates. © 2011 American Chemical Society

  3. Effects of chondroitin sulfate on brain response to painful stimulation in knee osteoarthritis patients. A randomized, double-blind, placebo-controlled functional magnetic resonance imaging study.

    Monfort, Jordi; Pujol, Jesús; Contreras-Rodríguez, Oren; Llorente-Onaindia, Jone; López-Solà, Marina; Blanco-Hinojo, Laura; Vergés, Josep; Herrero, Marta; Sánchez, Laura; Ortiz, Hector; Montañés, Francisco; Deus, Joan; Benito, Pere

    2017-06-21

    Knee osteoarthritis is causing pain and functional disability. One of the inherent problems with efficacy assessment of pain medication was the lack of objective pain measurements, but functional magnetic resonance imaging (fMRI) has emerged as a useful means to objectify brain response to painful stimulation. We have investigated the effect of chondroitin sulfate (CS) on brain response to knee painful stimulation in patients with knee osteoarthritis using fMRI. Twenty-two patients received CS (800mg/day) and 27 patients placebo, and were assessed at baseline and after 4 months of treatment. Two fMRI tests were conducted in each session by applying painful pressure on the knee interline and on the patella surface. The outcome measurement was attenuation of the response evoked by knee painful stimulation in the brain. fMRI of patella pain showed significantly greater activation reduction under CS compared with placebo in the region of the mesencephalic periaquecductal gray. The CS group, additionally showed pre/post-treatment activation reduction in the cortical representation of the leg. No effects of CS were detected using the interline pressure test. fMRI was sensitive to objectify CS effects on brain response to painful pressure on patellofemoral cartilage, which is consistent with the known CS action on chondrocyte regeneration. The current work yields further support to the utility of fMRI to objectify treatment effects on osteoarthritis pain. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  4. Analysis of tyrosine-O-sulfation

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  5. Chondroitin sulfate synthase-2 is necessary for chain extension of chondroitin sulfate but not critical for skeletal development.

    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.

  6. Development of a sodium dodecyl sulfate-polyacrylamide gel electrophoresis reference method for the analysis and identification of fish species in raw and heat-processed samples : A collaborative study

    Pineiro, C.; Barros-Velazquez, J.; Perez-Martin, R.I.

    1999-01-01

    A collaborative study was carried out in seven European labs with the aim of achieving a sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) standard operation procedure to identify fish species in raw and cooked samples. Urea and SDS-containing solutions were evaluated...... silver stained, yielded good results and afforded higher reproducibility, thus allowing a better matching of results among the laboratories participating in this collaborative study. Under the optimized technical conditions described above, all the fish species tested, either raw and cooked, yielded...... seemed not to be influenced so much by the state of the sample (raw, cooked at 60 degrees C, cooked at 85 degrees C). Desalting, ultrafiltration or treatment with RNase/DNase did not improve the discriminatory power of the protein patterns. Commercial homogeneous 15% ExcelGels, especially when they were...

  7. Methods for Engineering Sulfate Reducing Bacteria of the Genus Desulfovibrio

    Chhabra, Swapnil R; Keller, Kimberly L.; Wall, Judy D.

    2011-03-15

    Sulfate reducing bacteria are physiologically important given their nearly ubiquitous presence and have important applications in the areas of bioremediation and bioenergy. This chapter provides details on the steps used for homologous-recombination mediated chromosomal manipulation of Desulfovibrio vulgaris Hildenborough, a well-studied sulfate reducer. More specifically, we focus on the implementation of a 'parts' based approach for suicide vector assembly, important aspects of anaerobic culturing, choices for antibiotic selection, electroporation-based DNA transformation, as well as tools for screening and verifying genetically modified constructs. These methods, which in principle may be extended to other sulfate-reducing bacteria, are applicable for functional genomics investigations, as well as metabolic engineering manipulations.

  8. Bactericide for sulfate-reducing bacteria

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

    1981-01-01

    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  9. Optimizing substrate for sulfate-reducing bacteria

    Chang, L.K.; Updegraff, D.M.; Wildeman, T.R.

    1991-01-01

    Microbial sulfate reduction followed by sulfide precipitation effectively removes heavy metals from wastewaters. The substrate in the anaerobic zone in a constructed wetland can be designed to emphasize this removal process. This group of bacteria requires CH 2 O, P, N, and SO 4 =, reducing conditions, and pH range of 5-9 (pH=7 is optimum). The objective of this study was to find an inexpensive source of nutrients that would give the best initial production of sulfide and make a good wetland substrate. All tested materials contain sufficient P and N; mine drainage provides sulfate. Thus, tests focused on finding organic material that provides the proper nutrients and does not cause the culture to fall below pH of 5. Among chemical nutrients, sodium lactate combined with (NH 4 ) 2 HPO 4 were the only compounds that produced sulfide after 11 days. Among complex nutrients, only cow manure produced sulfide after 26 days. Among complex carbohydrates, cracked corn and raw rice produced sulfide after 10 days. Most substrates failed to produce sulfide because anaerobic fermentation reduced the pH below 5. Presently, cracked corn is the best candidate for a substrate. Five grams of cow manure produced 0.14 millimole of sulfide whereas 0.1 g of cracked corn produced 0.22 millimole

  10. Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library

    Sugiura, Nobuo; Clausen, Thomas Mandel; Shioiri, Tatsuasa

    2016-01-01

    with chondroitin sulfate (CS) proteoglycans present in the placental tissue. CS is a linear acidic polysaccharide composed of repeating disaccharide units of d-glucuronic acid and N-acetyl-d-galactosamine that are modified by sulfate groups at different positions. Previous reports have shown that placental......-adhering IEs were associated with an unusually low sulfated form of chondroitin sulfate A (CSA) and that a partially sulfated dodecasaccharide is the minimal motif for the interaction. However, the fine molecular structure of this CS chain remains unclear. In this study, we have characterized the CS chain...... that interacts with a recombinant minimal CS-binding region of VAR2CSA (rVAR2) using a CS library of various defined lengths and sulfate compositions. The CS library was chemo-enzymatically synthesized with bacterial chondroitin polymerase and recombinant CS sulfotransferases. We found that C-4 sulfation...

  11. Removal of Sulfate from Waste Water by Activated Carbon

    Mohammed Sadeq Salman

    2009-01-01

    Activated carbon was Produced from coconut shell and was used for removing sulfate from industrial waste water in batch Processes. The influence of various parameter were studied such as pH (4.5 9.) , agitation time (0 120)min and adsorbent dose (2 10) gm.The Langmuir and frandlich adsorption capacity models were been investigated where showed there are fitting with langmmuir model with squre regression value ( 0.76). The percent of removal of sulfate (22% - 38%) at (PH=7) in the isotherm ...

  12. Bacterial PerO Permeases Transport Sulfate and Related Oxyanions.

    Hoffmann, Marie-Christine; Pfänder, Yvonne; Tintel, Marc; Masepohl, Bernd

    2017-07-15

    Rhodobacter capsulatus synthesizes the high-affinity ABC transporters CysTWA and ModABC to specifically import the chemically related oxyanions sulfate and molybdate, respectively. In addition, R. capsulatus has the low-affinity permease PerO acting as a general oxyanion transporter, whose elimination increases tolerance to molybdate and tungstate. Although PerO-like permeases are widespread in bacteria, their function has not been examined in any other species to date. Here, we present evidence that PerO permeases from the alphaproteobacteria Agrobacterium tumefaciens , Dinoroseobacter shibae , Rhodobacter sphaeroides , and Sinorhizobium meliloti and the gammaproteobacterium Pseudomonas stutzeri functionally substitute for R. capsulatus PerO in sulfate uptake and sulfate-dependent growth, as shown by assimilation of radioactively labeled sulfate and heterologous complementation. Disruption of perO genes in A. tumefaciens , R. sphaeroides , and S. meliloti increased tolerance to tungstate and, in the case of R. sphaeroides , to molybdate, suggesting that heterometal oxyanions are common substrates of PerO permeases. This study supports the view that bacterial PerO permeases typically transport sulfate and related oxyanions and, hence, form a functionally conserved permease family. IMPORTANCE Despite the widespread distribution of PerO-like permeases in bacteria, our knowledge about PerO function until now was limited to one species, Rhodobacter capsulatus In this study, we showed that PerO proteins from diverse bacteria are functionally similar to the R. capsulatus prototype, suggesting that PerO permeases form a conserved family whose members transport sulfate and related oxyanions. Copyright © 2017 American Society for Microbiology.

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

    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 (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.

  14. Studies on the interactions of chloroquine diphosphate and phenelzine sulfate drugs with human serum albumin and human hemoglobin proteins by spectroscopic techniques

    Tunç, Sibel, E-mail: stunc@akdeniz.edu.tr; Duman, Osman, E-mail: osmanduman@akdeniz.edu.tr; Bozoğlan, Bahar Kancı

    2013-08-15

    The interactions of chloroquine diphosphate (CQP) and phenelzine sulfate (PS) drugs with human serum albumin (HSA) and human hemoglobin (HMG) proteins were investigated by various spectroscopic methods. It was found that CQP caused the fluorescence quenching of protein molecules through a static quenching mechanism, but PS did not. The values of Stern–Volmer quenching constant, bimolecular quenching constant, binding constant and number of binding site on the protein molecules were calculated for HSA–CQP and HMG–CQP systems at pH 7.4 and different temperatures. For CQP, there was only one binding site on HSA and HMG proteins and the binding affinity of HSA was higher than that of HMG. The binding constants decreased with increasing temperature. The values of negative enthalpy change and positive entropy change indicated that electrostatic interactions play an important role in the binding processes. In addition, the binding processes were spontaneous and carried out by exothermic reactions. According to Förster resonance energy transfer theory, the average binding distance between proteins and CQP was calculated as 3.72 nm for HSA–CQP system and 3.45 nm for HMG–CQP system. Circular dichroism analysis displayed that the addition of CQP led to a decrease in the α-helix amount of HSA and HMG proteins. -- Highlights: • Unlike PS, CQP was bounded by HSA and HMG proteins. • The fluorescence spectra of HSA and HMG were quenched by CQP through static mechanism. • HSA–CQP and HMG–CQP complexes were stabilized by electrostatic attraction forces. • Binding constants, thermodynamic parameters and binding distances were calculated. • The binding of CQP changed the conformational structure of HSA and HMG proteins.

  15. Studies on mathematical modeling of the leaching process in order to efficiently recover lead from the sulfate/oxide lead paste.

    Buzatu, Traian; Ghica, Gabriel Valeriu; Petrescu, Ionuţ Mircea; Iacob, Gheorghe; Buzatu, Mihai; Niculescu, Florentina

    2017-02-01

    Increasing global lead consumption has been mainly supported by the acid battery manufacturing industry. As the lead demand will continue to grow, to provide the necessary lead will require an efficient approach to recycling lead acid batteries. In this paper was performed a mathematical modeling of the process parameters for lead recovery from spent lead-acid batteries. The results of the mathematical modeling compare well with the experimental data. The experimental method applied consists in the solubilisation of the sulfate/oxide paste with sodium hydroxide solutions followed by electrolytic processing for lead recovery. The parameters taken into considerations were NaOH molarity (4M, 6M and 8M), solid/liquid ratio - S/L (1/10, 1/30 and 1/50) and temperature (40°C, 60°C and 80°C). The optimal conditions resulted by mathematical modeling of the electrolytic process of lead deposition from alkaline solutions have been established by using a second-order orthogonal program, in order to obtain a maximum efficiency of current without exceeding an imposed energy specific consumption. The optimum value for the leaching recovery efficiency, obtained through mathematical modeling, was 89.647%, with an error of δ y =3.623 which leads to a maximum recovery efficiency of 86.024%. The optimum values for each variable that ensure the lead extraction efficiency equal to 89.647% are the following: 3M - NaOH, 1/35 - S/L, 70°C - temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Process integration for biological sulfate reduction in a carbon monoxide fed packed bed reactor.

    Kumar, Manoj; Sinharoy, Arindam; Pakshirajan, Kannan

    2018-05-09

    This study examined immobilized anaerobic biomass for sulfate reduction using carbon monoxide (CO) as the sole carbon source under batch and continuous fed conditions. The immobilized bacteria with beads made of 10% polyvinyl alcohol (PVA) showed best results in terms of sulfate reduction (84 ± 3.52%) and CO utilization (98 ± 1.67%). The effect of hydraulic retention time (HRT), sulfate loading rate and CO loading rate on sulfate and CO removal was investigated employing a 1L packed bed bioreactor containing the immobilized biomass. At 48, 24 and 12 h HRT, the sulfate removal was 94.42 ± 0.15%, 89.75 ± 0.47% and 61.08 ± 0.34%, respectively, along with a CO utilization of more than 90%. The analysis of variance (ANOVA) of the results obtained showed that only the initial CO concentration significantly affected the sulfate reduction process. The reactor effluent sulfate concentrations were 27.41 ± 0.44, 59.16 ± 1.08, 315.83 ± 7.33 mg/L for 250, 500 and 1000 mg/L of influent sulfate concentrations respectively, under the optimum operating conditions. The sulfate reduction rates matched well with low inlet sulfate loading rates, indicating stable performance of the bioreactor system. Overall, this study yielded very high sulfate reduction efficiency by the immobilized anaerobic biomass under high CO loading condition using the packed bed reactor system. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. On the sulfation of O-desmethyltramadol by human cytosolic sulfotransferases.

    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.

  18. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    Ozuolmez, D.; Na, H.; Lever, M.A.; Kjeldsen, K.U.; Jørgensen, B.B.; Plugge, C.M.

    2015-01-01

    Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and

  19. Tillage and water management for riceland productivity in acid sulfate soils of the Mekong delta, Vietnam.

    Minh, L.Q.; Tuong, T.P.; Mensvoort, van M.E.F.; Bouma, J.

    1997-01-01

    Acid sulfate soils are characterized by low pH and high concentrations of aluminum, sulfate, iron and hydrogen sulfide. Removal of at least part of these substances is a prerequisite for land use, at least in severely acid soils. In this study, the effectiveness of harrowing and flushing with

  20. The effects of hydrologic fluctuation and sulfate regeneration on mercury cycling in an experimental peatland

    J.K. Coleman Wasik; D.R. Engstrom; C.P.J. Mitchell; E.B. Swain; B.A. Monson; S.J. Balogh; J.D. Jeremiason; B.A. Branfireun; R.K. Kolka; J.E. Almendinger

    2015-01-01

    A series of severe droughts during the course of a long-term, atmospheric sulfate-deposition experiment in a boreal peatland in northern Minnesota created a unique opportunity to study how methylmercury (MeHg) production responds to drying and rewetting events in peatlands under variable levels of sulfate loading. Peat oxidation during extended dry periods mobilized...

  1. Fish Mercury and Surface Water Sulfate Relationships in the Everglades Protection Area

    Few published studies present data on relationships between fish mercury and surface or pore water sulfate concentrations, particularly on an ecosystem-wide basis. Resource managers can use these relationships to identify the sulfate conditions that contain fish with health-conce...

  2. Effects of magnesium sulfate on the foliar absorption of phosphates at the pumpkin

    Chamel, A.

    1962-01-01

    The foliar absorption of phosphates labelled with 32 P and applied with or without magnesium sulfate on the first leaf of pumpkin seedlings have been studied. The magnesium sulfate applied with the phosphate reduces plainly the absorption rate of 32 P. (O.M.) [fr

  3. 21 CFR 172.822 - Sodium lauryl sulfate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium lauryl sulfate. 172.822 Section 172.822 Food... Multipurpose Additives § 172.822 Sodium lauryl sulfate. The food additive sodium lauryl sulfate may be safely... specifications: (1) It is a mixture of sodium alkyl sulfates consisting chiefly of sodium lauryl sulfate [CH2(CH2...

  4. The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch grown in the field and sugar beet (Beta vulgaris L. grown in hydroponics

    Hamdi eEl-Jendoubi

    2014-01-01

    Full Text Available Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch trees grown in the field and sugar beet (Beta vulgaris L. cv. ‘Orbis’ grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated and basal (untreated leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

  5. The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch) grown in the field and sugar beet (Beta vulgaris L.) grown in hydroponics.

    El-Jendoubi, Hamdi; Vázquez, Saúl; Calatayud, Angeles; Vavpetič, Primož; Vogel-Mikuš, Katarina; Pelicon, Primož; Abadía, Javier; Abadía, Anunciación; Morales, Fermín

    2014-01-01

    Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch) trees grown in the field and sugar beet (Beta vulgaris L. cv. "Orbis") grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated) and basal (untreated) leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume) and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

  6. Contribution to the study of the role of sulfate-reducing bacteria in bio-corrosion phenomenon; Contribution a l'etude du role des bacteries sulfato-reductrices dans les phenomenes de biocorrosion

    Chatelus, C

    1987-11-15

    By their metabolic activities of hydrogen consumption and of sulfides production, the sulfate-reducing bacteria are the main bacteria responsible of the metallic corrosion phenomena in the absence of oxygen. A physiological and enzymatic study of some Desulfovibrio has contributed to the understanding of the role of these bacteria in the anaerobic bio-corrosion phenomena. Desulfovibrio (D.) vulgaris in organic medium, after having oxidized the lactate, consumes the hydrogen formed by the electrochemical reaction of iron dissolution. The Desulfovibrio can be responsible either of a corrosion by a direct contact with the metal in using the H{sub 2} layer formed at its surface, (bacteria are then adsorbed at the surface because of an iron sulfide crystalline lattice), or of a distant corrosion in consuming the dissolved or gaseous hydrogen. As their hydrogenases can be stable in time independently of the cellular structure (D. vulparis) and active at high temperatures (to 70 C - 75 C) (D. baculatus), these bacteria can act in conditions incompatible with the viability of cells but compatible with the enzymatic expression. A study in terms of temperature has shown that inside the mesophilic group of the Desulfovibrio, the behaviour towards this parameter is specific to each bacteria, that accounts for the permanent presence of the representatives of this population in sites where the temperature variations are important. A change of some degrees Celsius can induce modifications in the yields of bacteria growth and by a consequence in variations in the corrosion intensity. Moreover, sulfate D. multispirans can reduce with specific velocities of different growth, the nitrate, the nitrite and the fumarate. Some sulfato-reducing could then adapt themselves to the variations of concentrations in electron acceptors and metabolize the oxidized substances used as biocides too. The choice of an electron acceptor rather than another do not depend uniquely of the specificity of

  7. Contribution to the study of the role of sulfate-reducing bacteria in bio-corrosion phenomenon; Contribution a l'etude du role des bacteries sulfato-reductrices dans les phenomenes de biocorrosion

    Chatelus, C

    1987-11-15

    By their metabolic activities of hydrogen consumption and of sulfides production, the sulfate-reducing bacteria are the main bacteria responsible of the metallic corrosion phenomena in the absence of oxygen. A physiological and enzymatic study of some Desulfovibrio has contributed to the understanding of the role of these bacteria in the anaerobic bio-corrosion phenomena. Desulfovibrio (D.) vulgaris in organic medium, after having oxidized the lactate, consumes the hydrogen formed by the electrochemical reaction of iron dissolution. The Desulfovibrio can be responsible either of a corrosion by a direct contact with the metal in using the H{sub 2} layer formed at its surface, (bacteria are then adsorbed at the surface because of an iron sulfide crystalline lattice), or of a distant corrosion in consuming the dissolved or gaseous hydrogen. As their hydrogenases can be stable in time independently of the cellular structure (D. vulparis) and active at high temperatures (to 70 C - 75 C) (D. baculatus), these bacteria can act in conditions incompatible with the viability of cells but compatible with the enzymatic expression. A study in terms of temperature has shown that inside the mesophilic group of the Desulfovibrio, the behaviour towards this parameter is specific to each bacteria, that accounts for the permanent presence of the representatives of this population in sites where the temperature variations are important. A change of some degrees Celsius can induce modifications in the yields of bacteria growth and by a consequence in variations in the corrosion intensity. Moreover, sulfate D. multispirans can reduce with specific velocities of different growth, the nitrate, the nitrite and the fumarate. Some sulfato-reducing could then adapt themselves to the variations of concentrations in electron acceptors and metabolize the oxidized substances used as biocides too. The choice of an electron acceptor rather than another do not depend uniquely of the specificity of

  8. Weak bases and formation of a less soluble lauryl sulfate salt/complex in sodium lauryl sulfate (SLS) containing media.

    Bhattachar, Shobha N; Risley, Donald S; Werawatganone, Pornpen; Aburub, Aktham

    2011-06-30

    This work reports on the solubility of two weakly basic model compounds in media containing sodium lauryl sulfate (SLS). Results clearly show that the presence of SLS in the media (e.g. simulated gastric fluid or dissolution media) can result in an underestimation of solubility of some weak bases. We systematically study this phenomenon and provide evidence (chromatography and pXRD) for the first time that the decrease in solubility is likely due to formation of a less soluble salt/complex between the protonated form of the weak base and lauryl sulfate anion. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Investigation of kinetics and absorption isotherm models for hydroponic phytoremediation of waters contaminated with sulfate.

    Saber, Ali; Tafazzoli, Milad; Mortazavian, Soroosh; James, David E

    2018-02-01

    Two common wetland plants, Pampas Grass (Cortaderia selloana) and Lucky Bamboo (Dracaena sanderiana), were used in hydroponic cultivation systems for the treatment of simulated high-sulfate wastewaters. Plants in initial experiments at pH 7.0 removed sulfate more efficiently compared to the same experimental conditions at pH 6.0. Results at sulfate concentrations of 50, 200, 300, 600, 900, 1200, 1500 and 3000 mg/L during three consecutive 7-day treatment periods with 1-day rest intervals, showed decreasing trends of both removal efficiencies and uptake rates with increasing sulfate concentrations from the first to the second to the third 7-day treatment periods. Removed sulfate masses per unit dry plant mass, calculated after 23 days, showed highest removal capacity at 600 mg/L sulfate for both plants. A Langmuir-type isotherm best described sulfate uptake capacity of both plants. Kinetic studies showed that compared to pseudo first-order kinetics, pseudo-second order kinetic models slightly better described sulfate uptake rates by both plants. The Elovich kinetic model showed faster rates of attaining equilibrium at low sulfate concentrations for both plants. The dimensionless Elovich model showed that about 80% of sulfate uptake occurred during the first four days' contact time. Application of three 4-day contact times with 2-day rest intervals at high sulfate concentrations resulted in slightly higher uptakes compared to three 7-day contact times with 1-day rest intervals, indicating that pilot-plant scale treatment systems could be sized with shorter contact times and longer rest-intervals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Gastrointestinal and microbial responses to sulfate-supplemented drinking water in mice.

    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. Structural elucidation of fucosylated chondroitin sulfates from sea cucumber using FTICR-MS/MS.

    Agyekum, Isaac; Pepi, Lauren; Yu, Yanlei; Li, Junhui; Yan, Lufeng; Linhardt, Robert J; Chen, Shiguo; Amster, I Jonathan

    2018-02-01

    Fucosylated chondroitin sulfates are complex polysaccharides extracted from sea cucumber. They have been extensively studied for their anticoagulant properties and have been implicated in other biological activities. While nuclear magnetic resonance spectroscopy has been used to extensively characterize fucosylated chondroitin sulfate oligomers, we herein report the first detailed mass characterization of fucosylated chondroitin sulfate using high-resolution Fourier transform ion cyclotron resonance mass spectrometry. The two species of fucosylated chondroitin sulfates considered for this work include Pearsonothuria graeffei (FCS-Pg) and Isostichopus badionotus (FCS-Ib). Fucosylated chondroitin sulfate oligosaccharides were prepared by N-deacetylation-deaminative cleavage of the two fucosylated chondroitin sulfates and purified by repeated gel filtration. Accurate mass measurements obtained from electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry measurements confirmed the oligomeric nature of these two fucosylated chondroitin sulfate oligosaccharides with each trisaccharide repeating unit averaging four sulfates per trisaccharide. Collision-induced dissociation of efficiently deprotonated molecular ions through Na/H + exchange proved useful in providing structurally relevant glycosidic and cross-ring product ions, capable of assigning the sulfate modifications on the fucosylated chondroitin sulfate oligomers. Careful examination of the tandem mass spectrometry of both species deferring in the positions of sulfate groups on the fucose residue (FCS-Pg-3,4- OS) and (FCS-Ib-2,4- OS) revealed cross-ring products 0,2 A αf and 2,4 X 2αf which were diagnostic for (FCS-Pg-3,4- OS) and 0,2 X 2αf diagnostic for (FCS-Ib-2,4- OS). Mass spectrometry and tandem mass spectrometry data acquired for both species varying in oligomer length (dp3-dp15) are presented.

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

    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.

  13. The influence of landing points on the sputtering of mono-crystal solids due to cluster impacting

    Niu, Guo-jian; Li, Xiao-chun; Xu, Qian; Yang, Zhong-shi, E-mail: zsyang@ipp.ac.cn; Luo, Guang-nan, E-mail: gnluo@ipp.ac.cn

    2017-01-15

    The mechanism of sputtering due to cluster impacting which has been widely studied is an important but unsolved problem. In present research, we discuss the effect of the landing point on the sputtering with the method of molecular dynamics. The results show that the landing points play significant roles on sputter yield when the temperature of target is low. Specific landing points can cause particular sputtering patterns which lead to different sputtering yield and moving directions of sputtered atoms. The mechanism of this phenomenon is that specific landing keeps symmetries and anisotropies of target lattice, which influence the sputtering yield.

  14. Reversibility of oxidation and aggregation of impurity in the system of potassium halide monocrystal-phosphite molecular centre

    Lebedev, A.V.; Bogdanova, T.G.; Vasil'ev, I.A.; Mel'nikova, I.N.

    1980-01-01

    Thermo- and radiation-stimulated reversible reaction of oxidation and aggregation of phosphorus in the composition of phosphite molecular centre in the matrix of potassium iodide are studied. It is shown that in the process of isothermal annealing and γ-radiolysis in the matrix of potassium iodide destruction of phosphite molecular centre takes place. It is established that it is accompanied by oxidation of trivalent phosphorus and aggregation of the formed phosphorus-oxygen anions. Reduction of the initial phosphite centre during the sample hardening is explained by the reverse reaction as a result of which electron-exceeding centres of the base are destructed and reduction of phosphorus takes place

  15. Dextran sulfate sodium-induced colitis in piglets

    Nielsen, Katrine Dalby; Schramm, Andreas; Purup, Stig

    Inflammatory bowel disease (IBD) results from complex interactions between genetic and environmental factors. Although a genetic contribution has been proven, dietary factors have also shown to play a role in the development of IBD. This study aims to investigate the effect of adding red meatto t...... the diet of piglets in a dextran sodium sulfate (DSS)-induced colitis model....

  16. Effects of adding aluminum sulfate to different litters on selected ...

    The objective of this study was to determine the effects of adding aluminum sulfate to different litters on blood plasma concentrations of some principal microelements and some vitamins in broilers. In this experiment, 645 day old Ross 308 broiler chicks were randomly divided into 4 litter group (straw, sawdust, alum ...

  17. Pre-harvest calcium sulfate application improves postharvest quality ...

    The quality of cut rose flowers at the postharvest stage is affected by pre-harvest conditions. The present study was conducted to examine the possible involvement of calcium sulfate (CaSO4) in regulation of rose flower senescence. Roses (Rosa hybrida L.) cultivars 'Cool Water' and 'Pretty Blinda', were treated with either ...

  18. Transformation of carbon tetrachloride under sulfate reducing conditions

    Best, Jappe H. de; Salminen, E.; Doddema, Hans J.; Janssen, Dick B.; Harder, Wim

    1998-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 µM, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  19. Transformation of carbon tetrachloride under sulfate reducing conditions

    de Best, JH; Salminen, E; Doddema, HJ; Janssen, DB; Harder, W

    1997-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 mu M, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  20. Mercury and lead tolerance in hypersaline sulfate-reducing bacteria

    Harithsa, S.; Kerkar, S.; LokaBharathi, P.A.

    -sporulating, non-motile rods lacking in desulfoviridin and cytochromes. Examination of these isolates for heavy metal tolerance and response studies in terms of growth and sulfate-reducing activity (SRA) were carried out using HgCl sub(2) and Pb(NO sub(3)) sub(2...

  1. Decomposition of Copper (II) Sulfate Pentahydrate: A Sequential Gravimetric Analysis.

    Harris, Arlo D.; Kalbus, Lee H.

    1979-01-01

    Describes an improved experiment of the thermal dehydration of copper (II) sulfate pentahydrate. The improvements described here are control of the temperature environment and a quantitative study of the decomposition reaction to a thermally stable oxide. Data will suffice to show sequential gravimetric analysis. (Author/SA)

  2. Prognostic significance of highly sulfated chondroitin sulfates in ovarian cancer defined by the single chain antibody GD3A11.

    van der Steen, Sophieke C H A; van Tilborg, Angela A G; Vallen, Myrtille J E; Bulten, Johan; van Kuppevelt, Toin H; Massuger, Leon F A G

    2016-03-01

    The extracellular matrix (ECM) of ovarian cancer may provide a number of potential biomarkers. Chondroitin sulfate (CS), a class of sulfated polysaccharides, is abundantly present in the ECM of ovarian cancer. Structural alterations of CS chains (i.e. sulfation pattern) have been demonstrated to play a role in cancer development and progression. In this study we investigate the potential of highly sulfated CS as a biomarker in ovarian cancer using the single chain antibody GD3A11 selected by the phage display technology. The specificity of the antibody was determined by an indirect ELISA. GD3A11 epitope expression was assessed by immunohistochemistry in healthy organs, benign and malignant ovarian tumors (N=359) and correlated to clinical parameters. The CHST15 gene, responsible for the biosynthesis of highly sulfated CS was evaluated for mutation and methylation status. The GD3A11 epitope was minimally expressed in normal organs. Intense expression was observed in the ECM of different ovarian cancer subtypes, in contrast to benign ovarian tumors. Expression was independent of tumor grade, FIGO stage, and the use chemotherapy. For the aggressive ovarian cancer phenotype, intense expression was identified as an independent predictor for poor prognosis. CHST15 gene analysis showed no mutations nor an altered methylation status. Specific highly sulfated CS motifs expressed in the tumoral ECM hold biomarker potential in ovarian cancer patients. These matrix motifs constitute a novel class of biomarkers with prognostic significance and may be instrumental for innovative diagnostic and therapeutic applications (e.g. targeted therapy) in management of ovarian cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. The anaerobic treatment of sulfate containing wastewater

    Visser, A.

    1995-01-01


    In the anaerobic treatment of sulfate containing wastewater sulfate reducing bacteria (SRB) will compete with methanogenic- (MB) and acetogenic bacteria (AB) for the available substrates such as hydrogen, acetate, propionate and butyrate. The outcome of this competition will

  4. Metodologia para o estudo da porosidade de dolomita em ensaio de sulfatação interrompida Methodology for the study of the dolomite porosity in essay of interrupted sulfation

    Ivonete Ávila

    2010-01-01

    Full Text Available The aim of this work is to propose a methodology to evaluate the evolution of the pore blockage of limestone during the sulfation reaction. The experiments were performed for a national limestone (dolomite with average particle size of 545 μm in interrupted sulfation tests were conducted at seven different times and at three different temperatures of the process. The empirical data were obtained from porosimetry tests to establish BET surface area, volume and average size of pore and distribution of pore sizes of the sulfated samples. Thermogravimetric tests were performed to evaluate the preparation methodology of the samples used in the porosimetry tests.

  5. Evaluation of antioxidant activities and chemical analysis of sulfated chitosan from Sepia prashadi.

    Seedevi, Palaniappan; Moovendhan, Meivelu; Vairamani, Shanmugam; Shanmugam, Annaian

    2017-06-01

    The chitin and chitosan of S. prashadi was prepared through demineralization, deproteinzation, deacetylation process and sulfation were carried by chlorosulfonic acid in N,N-dimethylformamide. The sulfate content in chitosan was found to be 18.9%. The carbon, hydrogen and nitrogen composition of the sulfated chitosan were recorded 39.09%, 6.95% and 6.58% respectively. The structural analysis was done by using FT-IR and NMR spectroscopy technique. The DSC curves of sulfated chitosan showed a large endothermic peak resolved with T o value of 54.57°C and T P value of 97.46°C. The morphology of sulfated chitin and sulfated chitosan were studied by SEM. The Further in vitro antioxidant activity of sulfated chitosan was screened by scavenging activity of superoxide radical assay, hydroxyl radical scavenging assay, metal-ion chelating effect and reducing power. Its anticoagulant activity was tested for human plasma with respect to Activated Partial Thromboplastin Time (APTT) and Prothrombin Time (PT). Results prove that sulfated chitosan has potent antioxidant and anticoagulant activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Modulation of the expression of chondroitin sulfate proteoglycan in stimulated human monocytes

    Uhlin-Hansen, L.; Eskeland, T.; Kolset, S.O.

    1989-01-01

    Proteoglycan biosynthesis was studied in human monocytes and monocyte-derived macrophages (MDM) after exposure to typical activators of the monocyte/macrophage system: interferon-gamma (IFN-gamma), lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA). By morphological examination, both monocytes and MDM were stimulated by these activators. Treatment with IFN-gamma resulted in a slight decrease in the expression of [35S]chondroitin sulfate proteoglycan (CSPG) in both monocytes and MDM, whereas LPS treatment increased the [35S]CSPG expression 1.8 and 2.2 times, respectively. PMA, in contrast, decreased the CSPG expression 0.4 times in monocytes, whereas MDM were stimulated to increase the biosynthesis 1.9 times. An increase in the sulfate density of the chondroitin sulfate chains was evident following differentiation of monocytes into MDM due to the expression of disulfated disaccharide units of the chondroitin sulfate E type (CS-E). However, monocytes exposed to PMA did also express disaccharides of the chondroitin sulfate E type. Furthermore, the expression of CS-E in MDM was increased 2 times following PMA treatment. An inactive phorbol ester, phorbol 12,13-diacetate, did not affect the expression of CS-E in either monocytes or MDM when compared with control cultures, suggesting that protein kinase C-dependent signal pathways may be involved in the regulation of sulfation of CSPG. Exposure to LPS or IFN-gamma did not lead to any changes in the sulfation of the chondroitin sulfate chains

  7. Metabolic Flexibility of Sulfate Reducing Bacteria

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  8. Synthesis, physico-chemical and biomedical applications of sulfated Aegle marmelos gum: Green chemistry approach

    Manish Jindal

    2017-05-01

    Full Text Available The present investigation was aimed at obtaining a sulfated derivative of gum obtained from partially ripe fruits of Aegle marmelos employing the ultrasonication technique. Elemental analysis and FTIR-ATR studies confirmed successful sulfation. The molarity of sulfuric acid exerted maximum influence on the degree of substitution followed by reaction temperature and reaction time. The sulfated derivative showed higher swelling in both acidic and alkaline pH as compared to the unmodified gum. It also possessed higher negative zeta potential, higher viscosity, work of shear, firmness, consistency, cohesiveness and index of viscosity as compared to both unmodified gum as well as sodium alginate. Sulfated derivative was superior to unmodified gum and sodium alginate in terms of antimicrobial and anticoagulant activities. The sulfated sample appears to be a potential substitute over the unmodified gum sample and sodium alginate for modulating the physicochemical properties of food and drug release dosage forms.

  9. Effect of mechanical activation on structure and thermal decomposition of aluminum sulfate

    Ghasri-Khouzani, M.; Meratian, M.; Panjepour, M.

    2009-01-01

    The thermal decompositions of both non-activated and mechanically activated aluminum sulfates were studied by thermogravimetry (TG). The structural disorder, the specific surface area (SSA) and the morphology of mechanically activated aluminum sulfates were analyzed by X-ray diffraction (XRD), laser particle-size analyzer, and scanning electron microscopy (SEM), respectively. Thermal analyses results indicated that the initial temperature of thermal decomposition (T i ) in TG curves for mechanically activated aluminum sulfates decreased gradually with increasing the milling time. It was also found that the SSA of mechanically activated aluminum sulfates remained almost constant after a certain milling time, and lattice strains (ε) rose but the crystallite sizes (D) decreased with increasing the milling time. These results showed that the decrease of T i in TG curves of mechanically activated aluminum sulfates was mainly caused by the increase of lattice distortions and decrease of the crystallite sizes with increasing the milling time

  10. Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

    Mangalo, Muna; Meckenstock, Rainer U.; Stichler, Willibald; Einsiedl, Florian

    2007-09-01

    Bacterial sulfate reduction is one of the most important respiration processes in anoxic habitats and is often assessed by analyzing the results of stable isotope fractionation. However, stable isotope fractionation is supposed to be influenced by the reduction rate and other parameters, such as temperature. We studied here the mechanistic basics of observed differences in stable isotope fractionation during bacterial sulfate reduction. Batch experiments with four sulfate-reducing strains ( Desulfovibrio desulfuricans, Desulfobacca acetoxidans, Desulfonatronovibrio hydrogenovorans, and strain TRM1) were performed. These microorganisms metabolize different carbon sources (lactate, acetate, formate, and toluene) and showed broad variations in their sulfur isotope enrichment factors. We performed a series of experiments on isotope exchange of 18O between residual sulfate and ambient water. Batch experiments were conducted with 18O-enriched (δ 18O water = +700‰) and depleted water (δ 18O water = -40‰), respectively, and the stable 18O isotope shift in the residual sulfate was followed. For Desulfovibrio desulfuricans and Desulfonatronovibrio hydrogenovorans, which are both characterized by low sulfur isotope fractionation ( ɛS > -13.2‰), δ 18O values in the remaining sulfate increased by only 50‰ during growth when 18O-enriched water was used for the growth medium. In contrast, with Desulfobacca acetoxidans and strain TRM1 ( ɛS factor ( ɛS exchange with water during sulfate reduction. However, this neither takes place in the sulfate itself nor during formation of APS (adenosine-5'-phosphosulfate), but rather in intermediates of the sulfate reduction pathway. These may in turn be partially reoxidized to form sulfate. This reoxidation leads to an incorporation of oxygen from water into the "recycled" sulfate changing the overall 18O isotopic composition of the remaining sulfate fraction. Our study shows that such incorporation of 18O is correlated with the

  11. Cloning and characterization of a novel chondroitin sulfate/dermatan sulfate 4-O-endosulfatase from a marine bacterium.

    Wang, Wenshuang; Han, Wenjun; Cai, Xingya; Zheng, Xiaoyu; Sugahara, Kazuyuki; Li, Fuchuan

    2015-03-20

    Sulfatases are potentially useful tools for structure-function studies of glycosaminoglycans (GAGs). To date, various GAG exosulfatases have been identified in eukaryotes and prokaryotes. However, endosulfatases that act on GAGs have rarely been reported. Recently, a novel HA and CS lyase (HCLase) was identified for the first time from a marine bacterium (Han, W., Wang, W., Zhao, M., Sugahara, K., and Li, F. (2014) J. Biol. Chem. 289, 27886-27898). In this study, a putative sulfatase gene, closely linked to the hclase gene in the genome, was recombinantly expressed and characterized in detail. The recombinant protein showed a specific N-acetylgalactosamine-4-O-sulfatase activity that removes 4-O-sulfate from both disaccharides and polysaccharides of chondroitin sulfate (CS)/dermatan sulfate (DS), suggesting that this sulfatase represents a novel endosulfatase. The novel endosulfatase exhibited maximal reaction rate in a phosphate buffer (pH 8.0) at 30 °C and effectively removed 17-65% of 4-O-sulfates from various CS and DS and thus significantly inhibited the interactions of CS and DS with a positively supercharged fluorescent protein. Moreover, this endosulfatase significantly promoted the digestion of CS by HCLase, suggesting that it enhances the digestion of CS/DS by the bacterium. Therefore, this endosulfatase is a potential tool for use in CS/DS-related studies and applications. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. N-acetylneuraminlactose sulfate in milk and its role in the synthesis of glycosaminoglycans during development

    Kieras, F.J.; Kastin, S.; Rerecich, M.; Sturman, J.A.

    1986-01-01

    Mammals in early life are incapable of synthesizing inorganic sulfate, an important constituent of connective tissue glycosaminoglycans (GAGs). Studies have shown that [ 35 S]Na 2 SO 4 injected into lactating rats is secreted into the milk as [ 35 S] N-acetylneuraminlactose sulfate (NLS); this compound accounts for ≥ 95% of the radioactivity found in milk. They have studied the metabolic fate of the sulfate moiety of NLS in the newborn rat. Lactating rat dams were injected with [ 35 S] Na 2 SO 4 at various times postpartum and pups were allowed to suckle for 48 hrs before sacrifice. Pups of varying ages (3 d. - 19 d.) were sacrificed and the GAGs were prepared from 9 different organs and tissues. Pups of all ages showed appreciable radiosulfate incorporated into all of the tissues and organs examined. In young pups (3 and 5 d old) a high of 75% of the total [ 35 S] sulfate in the homogenate was found in the GAGs of bone, and a low of 27% in the GAGs of liver. Analysis of the composition of the GAGs by enzymatic degradation showed that bone GAGs consisted entirely of chondroitin 4/6 sulfate (C4/6S) while liver GAGs contained 50% C4/6S, 10% dermatan sulfate (DS), and 40% chondroitinase resistant material (probably heparan sulfate). These data show that sulfate in the form of NLS is incorporated in substantial amounts into the sulfated GAGs of the developing rat and support the hypothesis that NLS is an important source of nutrient sulfate during rat development

  13. Copper sulfate acute ecotoxicity and environmental risk for tropical fish

    Adilson Ferreira da Silva

    2014-10-01

    Full Text Available The aim of this study was to estimate copper sulfate acute toxicity and to determine death percentage and environmental risk on guppy fish (Phallocerus caudimaculatus, zebrafish (Brachydanio rerio, mato grosso (Hyphessobrycon eques, and pacu (Piaractus mesopotamicus. Fish were exposed to 0.01, 0.03, 0.05, 0.07, 0.10, and 0.30 mg L-1 (guppy, 0.05, 0.07, 0.10, and 0.30 mg L-1 (zebrafish, 0.07, 0.10, 0.20, and 0.30 mg L-1 (mato grosso and 9.5, 10.0, 10.5, 11.0, 11.5, and 12.0 mg L-1 (pacu of copper sulfate, with triplicate control. The estimated 50% average lethal concentrations (LC50; 96 hours were 0.05 (guppy, 0.13 (zebrafish; 0.16 (mato grosso and 10.36 mg L-1 (pacu. Copper sulfate was extremely toxic for guppy, highly toxic for zebrafish and mato grosso and lightly toxic for pacu and presents environmental risk of high adverse effects on the guppy, zebrafish and mato grosso and moderate adverse effect to the pacu. Therefore, the guppy fish, zebrafish, and mato grosso are important alternatives for copper sulfate toxicity evaluation in waterbodies.

  14. Artemin Crystal Structure Reveals Insights into Heparan Sulfate Binding

    Silvian,L.; Jin, P.; Carmillo, P.; Boriack-Sjodin, P.; Pelletier, C.; Rushe, M.; Gong, B.; Sah, D.; Pepinsky, B.; Rossomando, A.

    2006-01-01

    Artemin (ART) promotes the growth of developing peripheral neurons by signaling through a multicomponent receptor complex comprised of a transmembrane tyrosine kinase receptor (cRET) and a specific glycosylphosphatidylinositol-linked co-receptor (GFR{alpha}3). Glial cell line-derived neurotrophic factor (GDNF) signals through a similar ternary complex but requires heparan sulfate proteoglycans (HSPGs) for full activity. HSPG has not been demonstrated as a requirement for ART signaling. We crystallized ART in the presence of sulfate and solved its structure by isomorphous replacement. The structure reveals ordered sulfate anions bound to arginine residues in the pre-helix and amino-terminal regions that were organized in a triad arrangement characteristic of heparan sulfate. Three residues in the pre-helix were singly or triply substituted with glutamic acid, and the resulting proteins were shown to have reduced heparin-binding affinity that is partly reflected in their ability to activate cRET. This study suggests that ART binds HSPGs and identifies residues that may be involved in HSPG binding.

  15. The effect of divalent salt in chondroitin sulfate solutions

    Aranghel, D., E-mail: daranghe@nipne.ro [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, daranghe@nipne.ro (Romania); Extreme Light Intrastructure Nuclear Physics (ELI-NP), Reactorului 30,RO-077125, POB-MG6, Magurele-Bucharest (Romania); Badita, C. R. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, daranghe@nipne.ro (Romania); University of Bucharest, Faculty of Physics, Atomiştilor 405, CP MG - 11, RO – 077125, Bucharest-Magurele (Romania); Radulescu, A. [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science, 85747 Garching (Germany); Moldovan, L.; Craciunescu, O. [National Institute R& D for Biological Sciences, Splaiul Independenţei 296, sector 6, cod 060031, C.P. 17-16, Bucharest (Romania); Balasoiu, M. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, daranghe@nipne.ro (Romania); Joint Institute for Nuclear Research, 141980 Dubna, Moscow region (Russian Federation)

    2016-03-25

    Chondroitin-4 sulfate (CS4) is the main glycosaminoglycan extracted from bovine trachea. CS4 play an important role in osteoarthritis treatment, anticoagulant activity, reduces the degradation of cartilage matrix components, reduces necrosis and apoptosis of chondrocytes and reduces the activity of collagenase. Chondroitin sulfate is also responsible for proteoglycans degradation. Chondroitin sulfate can bind calcium ions with different affinities, depending on their sulfation position. The purpose of this study was to determine the structural properties and the influence of Ca{sup 2+} cations. We carried out measurements on CS4 solutions and mixtures of liquid CS4 with Ca{sup 2+} by Small-Angle Neutron Scattering (SANS). CS4 have a mass fractal behavior and the addition of a salt (CaCl{sub 2}) in CS4 solutions generates the appearance of a correlation peak due to local ordering between adjacent chains with inter-chain distances between 483 Å and 233 Å for a calcium concentration of 0.01% w/w.

  16. The effect of divalent salt in chondroitin sulfate solutions

    Aranghel, D.; Badita, C. R.; Radulescu, A.; Moldovan, L.; Craciunescu, O.; Balasoiu, M.

    2016-03-01

    Chondroitin-4 sulfate (CS4) is the main glycosaminoglycan extracted from bovine trachea. CS4 play an important role in osteoarthritis treatment, anticoagulant activity, reduces the degradation of cartilage matrix components, reduces necrosis and apoptosis of chondrocytes and reduces the activity of collagenase. Chondroitin sulfate is also responsible for proteoglycans degradation. Chondroitin sulfate can bind calcium ions with different affinities, depending on their sulfation position. The purpose of this study was to determine the structural properties and the influence of Ca2+ cations. We carried out measurements on CS4 solutions and mixtures of liquid CS4 with Ca2+ by Small-Angle Neutron Scattering (SANS). CS4 have a mass fractal behavior and the addition of a salt (CaCl2) in CS4 solutions generates the appearance of a correlation peak due to local ordering between adjacent chains with inter-chain distances between 483 Å and 233 Å for a calcium concentration of 0.01% w/w.

  17. The effect of divalent salt in chondroitin sulfate solutions

    Aranghel, D.; Badita, C. R.; Radulescu, A.; Moldovan, L.; Craciunescu, O.; Balasoiu, M.

    2016-01-01

    Chondroitin-4 sulfate (CS4) is the main glycosaminoglycan extracted from bovine trachea. CS4 play an important role in osteoarthritis treatment, anticoagulant activity, reduces the degradation of cartilage matrix components, reduces necrosis and apoptosis of chondrocytes and reduces the activity of collagenase. Chondroitin sulfate is also responsible for proteoglycans degradation. Chondroitin sulfate can bind calcium ions with different affinities, depending on their sulfation position. The purpose of this study was to determine the structural properties and the influence of Ca"2"+ cations. We carried out measurements on CS4 solutions and mixtures of liquid CS4 with Ca"2"+ by Small-Angle Neutron Scattering (SANS). CS4 have a mass fractal behavior and the addition of a salt (CaCl_2) in CS4 solutions generates the appearance of a correlation peak due to local ordering between adjacent chains with inter-chain distances between 483 Å and 233 Å for a calcium concentration of 0.01% w/w.

  18. THE IMPACT OF BIOSTIMULATION ON THE FATE OF SULFATE AND ASSOCIATED SULFUR DYNAMICS IN GROUNDWATER

    Miao, Ziheng; Carreón-Diazconti, Concepcion; Carroll, Kenneth C.; Brusseau, Mark L.

    2014-01-01

    The impact of electron-donor addition on sulfur dynamics for a groundwater system with low levels of metal contaminants was evaluated with a pilot-scale biostimulation test conducted at a former uranium mining site. Geochemical and stable-isotope data collected before, during, and after the test were analyzed to evaluate the sustainability of sulfate reducing conditions induced by the test, the fate of hydrogen sulfide, and the impact on aqueous geochemical conditions. The results of site characterization activities conducted prior to the test indicated the absence of measurable bacterial sulfate reduction. The injection of an electron donor (ethanol) induced bacterial sulfate reduction, as confirmed by an exponential decrease of sulfate concentration in concert with changes in oxidation-reduction potential, redox species, alkalinity, production of hydrogen sulfide, and fractionation of δ34S-sulfate. High, stoichiometrically-equivalent hydrogen sulfide concentrations were not observed until several months after the start of the test. It is hypothesized that hydrogen sulfide produced from sulfate reduction was initially sequestered in the form of iron sulfides until the exhaustion of readily reducible iron oxides associated with the sediment. The fractionation of δ34S for sulfate was atypical, wherein the enrichment declined in the latter half of the experiment. It was conjectured that mixing effects associated with the release of sulfate from sulfate minerals associated with the sediments, along with possible sulfide re-oxidation contributed to this behavior. The results of this study illustrate the biogeochemical complexity that is associated with in-situ biostimulation processes involving bacterial sulfate reduction. PMID:25016586

  19. The impact of biostimulation on the fate of sulfate and associated sulfur dynamics in groundwater

    Miao, Ziheng; Carreón-Diazconti, Concepcion; Carroll, Kenneth C.; Brusseau, Mark L.

    2014-08-01

    The impact of electron-donor addition on sulfur dynamics for a groundwater system with low levels of metal contaminants was evaluated with a pilot-scale biostimulation test conducted at a former uranium mining site. Geochemical and stable-isotope data collected before, during, and after the test were analyzed to evaluate the sustainability of sulfate reducing conditions induced by the test, the fate of hydrogen sulfide, and the impact on aqueous geochemical conditions. The results of site characterization activities conducted prior to the test indicated the absence of measurable bacterial sulfate reduction. The injection of an electron donor (ethanol) induced bacterial sulfate reduction, as confirmed by an exponential decrease of sulfate concentration in concert with changes in oxidation-reduction potential, redox species, alkalinity, production of hydrogen sulfide, and fractionation of δ34S-sulfate. High, stoichiometrically-equivalent hydrogen sulfide concentrations were not observed until several months after the start of the test. It is hypothesized that hydrogen sulfide produced from sulfate reduction was initially sequestered in the form of iron sulfides until the exhaustion of readily reducible iron oxides within the sediment. The fractionation of δ34S for sulfate was atypical, wherein the enrichment declined in the latter half of the experiment. It was conjectured that mixing effects associated with the release of sulfate from sulfate minerals associated with the sediments, along with possible sulfide re-oxidation contributed to this behavior. The results of this study illustrate the biogeochemical complexity that is associated with in-situ biostimulation processes involving bacterial sulfate reduction.

  20. Global source attribution of sulfate concentration and direct and indirect radiative forcing

    Y. Yang

    2017-07-01

    Full Text Available The global source–receptor relationships of sulfate concentrations, and direct and indirect radiative forcing (DRF and IRF from 16 regions/sectors for years 2010–2014 are examined in this study through utilizing a sulfur source-tagging capability implemented in the Community Earth System Model (CESM with winds nudged to reanalysis data. 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 concentrations are primarily attributed to non-local sources from long-range transport. Regional source efficiencies of sulfate concentrations are higher over regions with dry atmospheric conditions and less export, suggesting that lifetime of aerosols, together with regional export, is important in determining regional air quality. The simulated global total sulfate DRF is −0.42 W m−2, with −0.31 W m−2 contributed by anthropogenic sulfate and −0.11 W m−2 contributed by natural sulfate, relative to a state with no sulfur emissions. In the Southern Hemisphere tropics, dimethyl sulfide (DMS contributes 17–84 % 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 incremental IRF of −0.44 W m−2. DMS has the largest contribution, explaining −0.23 W m−2 of the global sulfate incremental IRF. Incremental IRF over regions in the Southern Hemisphere with low background aerosols is more sensitive to emission perturbation than that over the polluted Northern Hemisphere.

  1. Global source attribution of sulfate concentration and direct and indirect radiative forcing

    Yang, Yang; Wang, Hailong; Smith, Steven J.; Easter, Richard; Ma, Po-Lun; Qian, Yun; Yu, Hongbin; Li, Can; Rasch, Philip J.

    2017-07-01

    The global source-receptor relationships of sulfate concentrations, and direct and indirect radiative forcing (DRF and IRF) from 16 regions/sectors for years 2010-2014 are examined in this study through utilizing a sulfur source-tagging capability implemented in the Community Earth System Model (CESM) with winds nudged to reanalysis data. 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 concentrations are primarily attributed to non-local sources from long-range transport. Regional source efficiencies of sulfate concentrations are higher over regions with dry atmospheric conditions and less export, suggesting that lifetime of aerosols, together with regional export, is important in determining regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with -0.31 W m-2 contributed by anthropogenic sulfate and -0.11 W m-2 contributed by natural sulfate, relative to a state with no sulfur emissions. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes 17-84 % 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 incremental IRF of -0.44 W m-2. DMS has the largest contribution, explaining -0.23 W m-2 of the global sulfate incremental IRF. Incremental IRF over regions in the Southern Hemisphere with low background aerosols is more sensitive to emission perturbation than that over the polluted Northern Hemisphere.

  2. 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.

    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.

  3. Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.).

    Alnsour, Mohammad; Kleinwächter, Maik; Böhme, Julia; Selmar, Dirk

    2013-03-15

    Horseradish plants (Armoracia rusticana) contain high concentrations of glucosinolates. Former studies have revealed that Armoracia plants cultivated in vitro have markedly lower glucosinolate concentrations than those grown in soils. Yet, these studies neglected that the sulfate concentration in the growth medium may have had a strong impact on glucosinolate metabolism. Accordingly, in this study horseradish in vitro plants were cultivated with differing sulfate concentrations and the glucosinolate concentrations were quantified by ion pair HPLC. Cultivation in 1.7 mmol L(-1) sulfate (as used in the prior studies) resulted in the accumulation of 16.2 µmol g(-1) DW glucosinolates, while the glucosinolate concentration increased to more than 23 µmol g(-1) DW when 23.5 mmol L(-1) sulfate was used in the medium. Correspondingly, the glucosinolate concentration decreased to 1.6 µmol g(-1) DW when sulfate concentration was lowered to 0.2 mmol L(-1). Since the glucosinolate accumulation in relation to the sulfate concentration follows a typical saturation curve, we deduce that the availability of sulfate determines the glucosinolate concentration in horseradish in vitro plants. © 2012 Society of Chemical Industry.

  4. Extraction of uranyl sulfate with primary amine

    Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

    1984-01-01

    PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

  5. Chlorate: a reversible inhibitor of proteoglycan sulfation

    Humphries, D.E.; Silbert, J.E.

    1988-01-01

    Bovine aorta endothelial cells were cultured in medium containing [ 3 H]glucosamine, [ 35 S]sulfate, and various concentrations of chlorate. Cell growth was not affected by 10 mM chlorate, while 30 mM chlorate had a slight inhibitory effect. Chlorate concentrations greater than 10 mM resulted in significant undersulfation of chondroitin. With 30 mM chlorate, sulfation of chondroitin was reduced to 10% and heparan to 35% of controls, but [ 3 H]glucosamine incorporation on a per cell basis did not appear to be inhibited. Removal of chlorate from the culture medium of cells resulted in the rapid resumption of sulfation

  6. Integrated approach for investigating the durability of self-consolidating concrete to sulfate attack

    Bassuoni, Mohamed Tamer F.

    The growing use of self-consolidating concrete (SCC) in various infrastructure applications exposed to sulfate-rich environments necessitates conducting comprehensive research to evaluate its durability to external sulfate attack. Since the reliability and adequacy of standard sulfate immersion tests have been questioned, the current thesis introduced an integrated testing approach for assessing the durability of a wide scope of SCC mixtures to external sulfate attack. This testing approach involved progressive levels of complexity from single to multiple damage processes. A new series of sulfate attack tests involving multiple field-like parameters and combined damage mechanisms (various cations, controlled pH, wetting-drying, partial immersion, freezing-thawing, and cyclic cold-hot conditions with or without sustained flexural loading) were designed to evaluate the performance (suitability) of the SCC mixtures under various sulfate attack exposure scenarios. The main mixture design variables of SCC included the type of binder (single, binary, ternary and quaternary), air-entrainment, sand-to-aggregate mass ratio and hybrid fibre reinforcement. The comprehensive database and knowledge obtained from this research were used to develop smart models (fuzzy and neuro-fuzzy inference systems) based on artificial-intelligence to evaluate and predict the performance of the SCC mixtures under various sulfate attack exposure regimes implemented in this study. In full immersion tests involving high concentration sodium and magnesium sulfate solutions with controlled pH, the low penetrability of SCC was responsible for the high durability of specimens. Ternary and quaternary cementitious systems with or without limestone materials provided a passivating layer, with or without acid neutralization capacity, which protected SCC from severe damage in the aggressive sulfuric acid and ammonium sulfate solutions. In contrast to conclusions drawn from the sodium sulfate immersion

  7. Polymorphism of nickel sulfate hexahydrate

    Angel, R.J.; Finger, L.W.

    1988-01-01

    NiSO 4 .6H 2 O, M r =262.85; data collections with Mo Kα radiation, λ=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, β=98.38(2) 0 , V=1704.7(6) A 3 , Z=8, D x =2.05 g cm -3 , μ=25.54 cm -1 , F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4 1 2 1 2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A 3 , Z=4, D x =2.07 g cm -3 , μ=25.81 cm -1 , F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO 4 .6D 2 O, and a number of other hexahydrate sulfates, e.g. MgSO 4 .6H 2 O. Both structures contain isolated [Ni(H 2 O 6 ] octahedra and [SO 4 ] tetrahedra linked by hydrogen bonding. (orig.)

  8. Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

    Wuman Zhang

    2017-01-01

    Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

  9. Methane Migration and Its Influence on Sulfate Reduction in the Good Weather Ridge Region, South China Sea Continental Margin Sediments

    Saulwood Lin

    2006-01-01

    Full Text Available Bacteria sulfate reduction is a major pathway for organic carbon oxidation in marine sediments. Upward diffusion of methane from gas hydrate deep in the sedimentary strata might be another important source of carbon for sulfate reducing bacteria and subsequently induce higher rates of sulfate reduction in sediments. Since abundant gas may migrate upward to the surface as a result of tectonic activity occurring in the accretionary wedge, this study investigates the effect of methane migration on the sulfate reduction process in continental margin sediments offshore southwestern Taiwan. Piston and gravity core samples were taken in order to evaluate vertical and spatial variations of sulfate and methane. Pore water sulfate, sulfide, methane, sediment pyrite, and organic carbon were extracted and analyzed.

  10. Lymphocyte mobilization by dextran sulfate in beagles

    Ragan, H.A.; Debban, K.H.

    1978-01-01

    Dogs manifesting 239 Pu-induced lymphopenia responded to the lymphocyte-mobilizing agent, dextran sulfate, to a degree similar to that observed in control dogs. No life-threatening increase in prothrombin times or hemorrhagic tendencies were observed

  11. Sulfated cellulose thin films with antithrombin affinity

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  12. COMBINED ALUMINIUM SULFATE/HYDROXIDE PROCESS FOR ...

    sulfate, and used for fluoride removal from water by combining with Nalgonda Technique. ... effects on human health and could result in fluorosis. ... [23], nanoscale aluminium oxide hydroxide (AlOOH) [24] and natural zeolite [25], were among.

  13. ROE Wet Sulfate Deposition 2009-2011

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  14. Effects of magnesium sulfate on the foliar absorption of phosphates at the pumpkin; Effets du sulfate de magnesium sur l'absorption foliaire de phosphates chez le potiron

    Chamel, A

    1962-07-01

    The foliar absorption of phosphates labelled with {sup 32}P and applied with or without magnesium sulfate on the first leaf of pumpkin seedlings have been studied. The magnesium sulfate applied with the phosphate reduces plainly the absorption rate of {sup 32}P. (O.M.) [French] Nous avons etudie l'absorption foliaire de phosphates marques au {sup 32}P appliques, avec et sans sulfate de magnesium, sur la premiere feuille de jeunes plants de potirons. Le sulfate de magnesium applique avec le phosphate diminue nettement le taux d'absorption du {sup 32}P. (auteur)

  15. Profile of irritant patch testing with detergents: sodium lauryl sulfate, sodium laureth sulfate and alkyl polyglucoside.

    Löffler, H; Happle, R

    2003-01-01

    The cutaneous reaction to detergents follows distinct kinetic rules: the duration of application and the irritant concentration are of major importance. The aim of this study was to evaluate the differences in kinetics of skin reaction between the standard irritant sodium lauryl sulfate (SLS), and 2 modern detergents: sodium laureth sulfate (SLES) and alkyl polyglucoside (APG). We performed patch testing with SLS and SLES (or APG) at different concentrations (0.125, 0.25, 0.5, 1.0 and 2.0%) and with different exposure times (6, 12 and 24 h). Evaluation was conducted by measurement of transepidermal water loss (TEWL) and laser Doppler flowmetry (LD) 24 h, 7 and 10 days after patch removal. We found a pronounced reaction to SLS, and a far milder one to SLES. Even at the highest concentration the skin reaction to APG was hard to detect. During the regeneration period (day 3-10) SLS showed even at day 10 an increased TEWL at all concentrations tested. The irritation due to SLES was convincingly detectable only up to day 7, whereas the APG-tested skin areas showed no significant reaction even at day 3. These results demonstrate the improvement in reduction of skin irritation achieved by development of novel detergents.

  16. The investigation on physico-chemical conditions of sulfides and sulfates based on petrographic and sulfur - oxygen stable isotope studies from the Darreh-Zar porphyry copper deposit, Kerman

    Anis Parsapoor

    2014-04-01

    Full Text Available The Darreh-Zar porphyry copper deposit, located in the Urumieh – Dokhtar magmatic belt, lies about 10 km southeast of Sar-Cheshmeh porphyry copper deposit. The ore body with hydrothermally altered zones including potassic, chlorite-sericite, sericite, argillic and propylitic all related to the Darreh-Zar porphyry stock intruded the Eocene volcanic rocks. Pyrite, chalcopyrite, molybdenite, with different textures as disseminated and veinlet, are the major sulfide minerals and chalcocite and covellite are considered as the secondary minerals. Sulfur isotopic composition of the sulfates and sulfides studied fall on the magmatic values. Two different origins may be suggested for the gypsums studied: 1- hydration of anhydrite and 2- oxidation of pyrite during supergene enrichment. The stable isotopic data calculated on couple minerals (pyrite-anhydrite point to the formation temperature of about 485-515οC for the fluids involved in mineralization. The fluid responsible for mineralization suggests magmatic sources for all sulfide phases and reduced aqueous sulfur species. Isotopic zoning, based on the δ34S pyrite values, divided the area into the east and the west parts with negative and positive correlation against the depth, respectively. Also, a negative correlation is observed between the Cu and the δ34S in the eastern portion of the area.

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

    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

  18. Electrochemical Deposition and Dissolution of Thallium from Sulfate Solutions

    Ye. Zh. Ussipbekova

    2015-01-01

    Full Text Available The electrochemical behavior of thallium was studied on glassy carbon electrodes in sulfate solutions. Cyclic voltammetry was used to study the kinetics of the electrode processes and to determine the nature of the limiting step of the cathodic reduction of thallium ions. According to the dependence of current on stirring rate and scan rate, this process is diffusion limited. Chronocoulometry showed that the electrodeposition can be performed with a current efficiency of up to 96% in the absence of oxygen.

  19. Sites of sulfate incorporation into mammotrophs and somatotrophs of the rat pituitary as determined by quantitative electron microscopic autoradiography

    Rosenzweig, L.J.; Farquhar, M.G.

    1980-01-01

    Dispersed pituitary cells were labeled with [ 35 S]sulfate followed by a chase incubation in order to study sulfate incorporation and transport in anterior pituitary cells. The initial site of incorporation of sulfate, the kinetics of sulfate transport, and the intracellular localization of incorporated sulfate were studied by quantitative electron microscope autoradiography. Analysis of autoradiograms from estrogen-treated female rats revealed that all granulated cell types incorporate sulfate. The labeling index of the various cell types was greatest for mammotrophs, slightly less for corticotrophs, gonadotrophs, and thyrotrophs and least for somatotrophs. These results indicate the [ 35 S]sulfate is initially incorporated into the Golgi complex of all interior pituitary cell types. The majority of the sulfate-labeled macromolecules are then packaged into immature secretion granules in the Golgi region, which become mature granules. In addition, a considerable amount (approx. 30% in mammotrophs) of the radioactivity remains associated within the Golgi region for up to 2 h post pulse. The incorporation of sulfate into the Golgi complex and its transfer to secretory granule membranes and/or contents thus appears to be a general property of anterior pituitary cells

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

    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.

  1. Polymorphism of nickel sulfate hexahydrate

    Angel, R.J.; Finger, L.W.

    1988-11-15

    NiSO/sub 4/.6H/sub 2/O, M/sub r/=262.85; data collections with Mo K..cap alpha.. radiation, lambda=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, ..beta..=98.38(2)/sup 0/, V=1704.7(6) A/sup 3/, Z=8, D/sub x/=2.05 g cm/sup -3/, ..mu..=25.54 cm/sup -1/, F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4/sub 1/2/sub 1/2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A/sup 3/, Z=4, D/sub x/=2.07 g cm/sup -3/, ..mu..=25.81 cm/sup -1/, F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO/sub 4/.6D/sub 2/O, and a number of other hexahydrate sulfates, e.g. MgSO/sub 4/.6H/sub 2/O. Both structures contain isolated (Ni(H/sub 2/O/sub 6/) octahedra and (SO/sub 4/) tetrahedra linked by hydrogen bonding.

  2. Spectroscopy of Loose and Cemented Sulfate-Bearing Soils: Implications for Duricrust on Mars

    Cooper, Christopher D.; Mustard, John F.

    2002-07-01

    The goal of this work is to determine the spectroscopic properties of sulfate in martian soil analogs over the wavelength range 0.3 to 25 μm (which is relevant to existing and planned remotely sensed data sets for Mars). Sulfate is an abundant component of martian soil (up to 9% SO 3 by weight) and apparently exists as a particulate in the soil but also as a cement. Although previous studies have addressed the spectroscopic identity of sulfates on Mars, none have used laboratory mixtures of materials with sulfates at the abundances measured by landed spacecraft, nor have any works considered the effect of salt-cementation on spectral properties of soil materials. For this work we created mixtures of a palagonitic soil (JSC Mars-1) and sulfates (MgSO 4 and CaSO 4·2H 2O). The effects of cementation were determined and separated from the effects of packing and hydration by measuring the samples as loose powders, packed powders, cemented materials, and disaggregated materials. The results show that the presence of particulate sulfate is best observed in the 4-5 μm region. Soils cemented with sulfate exhibit a pronounced restrahlen band between 8 and 9 μm as well as well-defined absorptions in the 4-5 μm region. Cementation effects are distinct from packing effects and disaggregation of cemented samples rapidly diminishes the strength of the restrahlen bands. The results of this study show that sulfate in loose materials is more detectable in the near infrared (4-5 μm) than in the thermal infrared (8-9 μm). However, cemented materials are easily distinguished from loose mixtures in the thermal infrared because of the high values of their absorption coefficient in this region. Together these results suggest that both wavelength regions are important for determining the spatial extent and physical form of sulfates on the surface of Mars.

  3. Effect of n-octanol on -uranyl extraction by tri-n-octylammonium sulfate

    Ochkin, A.V.; Kudrov, A.N.

    1984-01-01

    The effect of n-octanol on the extraction of uranyl sulfate by solutions of tri-n-octylamine sulfate in benzene has been studied. With the increase of alcohol concentration the coefficient of uranium distribution passes through the maximum. At low alcohol concentrations a decrease in water content in the organic phase is observed. It is shown that the increase in ammonium salt activity in replacement of part of hydrate At high alcohol concentration the decrease in uranium distribution coefficients is observed, which is related to TOA sulfate solvation by alcohol

  4. Detailed predictive mapping of acid sulfate soil occurrence using electromagnetic induction data

    Beucher, Amélie; Boman, A; Mattbäck, S

    impact through the resulting corrosion of concrete and steel infrastructures, or their poor geotechnical qualities. Therefore, mapping acid sulfate soil occurrence constitutes a key step to target the strategic areas for subsequent environmental risk management and mitigation. Conventional mapping (i...... obtained from a EM38 proximal sensor enabled the refined mapping of acid sulfate soils over a field (Huang et al. 2014). The present study aims at developing an efficient and reliable method for the detailed predictive mapping of acid sulfate soil occurrence in a field located in western Finland. Different...

  5. Sulfate minerals: a problem for the detection of organic compounds on Mars?

    Lewis, James M T; Watson, Jonathan S; Najorka, Jens; Luong, Duy; Sephton, Mark A

    2015-03-01

    The search for in situ organic matter on Mars involves encounters with minerals and requires an understanding of their influence on lander and rover experiments. Inorganic host materials can be helpful by aiding the preservation of organic compounds or unhelpful by causing the destruction of organic matter during thermal extraction steps. Perchlorates are recognized as confounding minerals for thermal degradation studies. On heating, perchlorates can decompose to produce oxygen, which then oxidizes organic matter. Other common minerals on Mars, such as sulfates, may also produce oxygen upon thermal decay, presenting an additional complication. Different sulfate species decompose within a large range of temperatures. We performed a series of experiments on a sample containing the ferric sulfate jarosite. The sulfate ions within jarosite break down from 500 °C. Carbon dioxide detected during heating of the sample was attributed to oxidation of organic matter. A laboratory standard of ferric sulfate hydrate released sulfur dioxide from 550 °C, and an oxygen peak was detected in the products. Calcium sulfate did not decompose below 1000 °C. Oxygen released from sulfate minerals may have already affected organic compound detection during in situ thermal experiments on Mars missions. A combination of preliminary mineralogical analyses and suitably selected pyrolysis temperatures may increase future success in the search for past or present life on Mars.

  6. Research on A3 steel corrosion behavior of basic magnesium sulfate cement

    Xing, Sainan; Wu, Chengyou; Yu, Hongfa; Jiang, Ningshan; Zhang, Wuyu

    2017-11-01

    In this paper, Tafel polarization technique is used to study the corrosion behavior of A3 steel basic magnesium sulfate, and then analyzing the ratio of raw materials cement, nitrites rust inhibitor and wet-dry cycle of basic magnesium sulfate corrosion of reinforced influence, and the steel corrosion behavior of basic magnesium sulfate compared with magnesium oxychloride cement and Portland cement. The results show that: the higher MgO/MgSO4 mole ratio will reduce the corrosion rate of steel; Too high and too low H2O/MgSO4 mole ratio may speed up the reinforcement corrosion effect; Adding a small amount of nitrite rust and corrosion inhibitor, not only can obviously reduce the alkali type magnesium sulfate in the early hydration of cement steel bar corrosion rate, but also can significantly reduce dry-wet circulation under the action of alkali type magnesium sulfate cement corrosion of reinforcement effect. Basic magnesium sulfate cement has excellent ability to protect reinforced, its long-term corrosion of reinforcement effect and was equal to that of Portland cement. Basic magnesium sulfate corrosion of reinforced is far below the level in the MOC in the case.

  7. Emerging sulfated flavonoids and other polyphenols as drugs: nature as an inspiration.

    Correia-da-Silva, Marta; Sousa, Emília; Pinto, Madalena M M

    2014-03-01

    Nature uses sulfation of endogenous and exogenous molecules mainly to avoid potential toxicity. The growing importance of natural sulfated molecules, as modulators of a number of physiological and pathological processes, has inspired the synthesis of non-natural sulfated scaffolds. Until the 1990s, the synthesis of sulfated small molecules was almost restricted to derivatives of flavonoids and aimed mainly at structure elucidation and plant biosynthesis studies. Currently, the synthesis of this type of compounds concerns structurally diverse scaffolds and is aimed at the development of potential drugs and/or exploitation of the biological effects of sulfated metabolites. Some important hit compounds are emerging from sulfated flavonoids and other polyphenols mainly as anticoagulant and antiviral agents. When compared with polymeric macromolecules such as heparins, sulfated small molecules could be of value in therapeutics due to their hydrophobic nature that can contribute to improve the bioavailability. This review highlights the synthetic approaches that were applied to obtain monosulfated or polysulfated phenolic small molecules and compiles the diverse biological activities already reported for this type of derivatives. Toxicity and pharmacokinetic parameters of this emerging class of derivatives will also be considered, emphasizing their value for therapeutic applications. © 2013 Wiley Periodicals, Inc.

  8. Secondary effects of anion exchange on chloride, sulfate, and lead release: systems approach to corrosion control.

    Willison, Hillary; Boyer, Treavor H

    2012-05-01

    Water treatment processes can cause secondary changes in water chemistry that alter finished water quality including chloride, sulfate, natural organic matter (NOM), and metal release. Hence, the goal of this research was to provide an improved understanding of the chloride-to-sulfate mass ratio (CSMR) with regards to chloride and sulfate variations at full-scale water treatment plants and corrosion potential under simulated premise plumbing conditions. Laboratory corrosion studies were conducted using Pb-Sn solder/Cu tubing galvanic cells exposed to model waters with low (approx. 5 mg/L Cl(-) and 10 mg/L SO(4)(2-)) and high (approx. 50 mg/L Cl(-) and 100 mg/L SO(4)(2-)) concentrations of chloride and sulfate at a constant CSMR of ≈ 0.5. The role of NOM during corrosion was also evaluated by changing the type of organic material. In addition, full-scale sampling was conducted to quantify the raw water variability of chloride, sulfate, and NOM concentrations and the changes to these parameters from magnetic ion exchange treatment. Test conditions with higher concentrations of chloride and sulfate released significantly more lead than the lower chloride and sulfate test waters. In addition, the source of NOM was a key factor in the amount of lead released with the model organic compounds yielding significantly less lead release than aquatic NOM. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Ionic and secretory response of pancreatic islet cells to minoxidil sulfate

    Antoine, M.H.; Hermann, M.; Herchuelz, A.; Lebrun, P.

    1991-01-01

    Minoxidil sulfate is an antihypertensive agent belonging to the new class of vasodilators, the K+ channel openers. The present study was undertaken to characterize the effects of minoxidil sulfate on ionic and secretory events in rat pancreatic islets. The drug unexpectedly provoked a concentration-dependent decrease in 86Rb outflow. This inhibitory effect was reduced in a concentration-dependent manner by glucose and tolbutamide. Minoxidil sulfate did not affect 45Ca outflow from islets perfused in the presence of extracellular Ca++ and absence or presence of glucose. However, in islets exposed to a medium deprived of extracellular Ca++, the drug provoked a rise in 45Ca outflow. Whether in the absence or presence of extracellular Ca++, minoxidil sulfate increased the cytosolic free Ca++ concentration of islet cells. Lastly, minoxidil sulfate increased the release of insulin from glucose-stimulated pancreatic islets. These results suggest that minoxidil sulfate reduces the activity of the ATP-sensitive K+ channels and promotes an intracellular translocation of Ca++. The latter change might account for the effect of the drug on the insulin-releasing process. However, the secretory response to minoxidil sulfate could also be mediated, at least in part, by a modest Ca++ entry

  10. Discrepancies in composition and biological effects of different formulations of chondroitin sulfate.

    Martel-Pelletier, Johanne; Farran, Aina; Montell, Eulàlia; Vergés, Josep; Pelletier, Jean-Pierre

    2015-03-06

    Osteoarthritis is a common, progressive joint disease, and treatments generally aim for symptomatic improvement. However, SYmptomatic Slow-Acting Drugs in Osteoarthritis (SYSADOAs) not only reduce joint pain, but slow structural disease progression. One such agent is chondroitin sulfate-a complex, heterogeneous polysaccharide. It is extracted from various animal cartilages, thus has a wide range of molecular weights and different amounts and patterns of sulfation. Chondroitin sulfate has an excellent safety profile, and although various meta-analyses have concluded that it has a beneficial effect on symptoms and structure, others have concluded little or no benefit. This may be due, at least partly, to variations in the quality of the chondroitin sulfate used for a particular study. Chondroitin sulfate is available as pharmaceutical- and nutraceutical-grade products, and the latter have great variations in preparation, composition, purity and effects. Moreover, some products contain a negligible amount of chondroitin sulfate and among samples with reasonable amounts, in vitro testing showed widely varying effects. Of importance, although some showed anti-inflammatory effects, others demonstrated weak effects, and some instances were even pro-inflammatory. This could be related to contaminants, which depend on the origin, production and purification process. It is therefore vitally important that only pharmaceutical-grade chondroitin sulfate be used for treating osteoarthritis patients.

  11. Effects of ultrasound and sodium lauryl sulfate on the transdermal delivery of hydrophilic permeants: Comparative in vitro studies with full-thickness and split-thickness pig and human skin.

    Seto, Jennifer E; Polat, Baris E; Lopez, Renata F V; Blankschtein, Daniel; Langer, Robert

    2010-07-01

    The simultaneous application of ultrasound and the surfactant sodium lauryl sulfate (referred to as US/SLS) to skin enhances transdermal drug delivery (TDD) in a synergistic mechanical and chemical manner. Since full-thickness skin (FTS) and split-thickness skin (STS) differ in mechanical strength, US/SLS treatment may have different effects on their transdermal transport pathways. Therefore, we evaluated STS as an alternative to the well-established US/SLS-treated FTS model for TDD studies of hydrophilic permeants. We utilized the aqueous porous pathway model to compare the effects of US/SLS treatment on the skin permeability and the pore radius of pig and human FTS and STS over a range of skin electrical resistivity values. Our findings indicate that the US/SLS-treated pig skin models exhibit similar permeabilities and pore radii, but the human skin models do not. Furthermore, the US/SLS-enhanced delivery of gold nanoparticles and quantum dots (two model hydrophilic macromolecules) is greater through pig STS than through pig FTS, due to the presence of less dermis that acts as an artificial barrier to macromolecules. In spite of greater variability in correlations between STS permeability and resistivity, our findings strongly suggest the use of 700microm-thick pig STS to investigate the in vitro US/SLS-enhanced delivery of hydrophilic macromolecules. 2010 Elsevier B.V. All rights reserved.

  12. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

  13. Microbial Diversity in Sulfate-Reducing Marine Sediment Enrichment Cultures Associated with Anaerobic Biotransformation of Coastal Stockpiled Phosphogypsum (Sfax, Tunisia

    Hana Zouch

    2017-08-01

    Full Text Available Anaerobic biotechnology using sulfate-reducing bacteria (SRB is a promising alternative for reducing long-term stockpiling of phosphogypsum (PG, an acidic (pH ~3 by-product of the phosphate fertilizer industries containing high amounts of sulfate. The main objective of this study was to evaluate, for the first time, the diversity and ability of anaerobic marine microorganisms to convert sulfate from PG into sulfide, in order to look for marine SRB of biotechnological interest. A series of sulfate-reducing enrichment cultures were performed using different electron donors (i.e., acetate, formate, or lactate and sulfate sources (i.e., sodium sulfate or PG as electron acceptors. Significant sulfide production was observed from enrichment cultures inoculated with marine sediments, collected near the effluent discharge point of a Tunisian fertilizer industry (Sfax, Tunisia. Sulfate sources impacted sulfide production rates from marine sediments as well as the diversity of SRB species belonging to Deltaproteobacteria. When PG was used as sulfate source, Desulfovibrio species dominated microbial communities of marine sediments, while Desulfobacter species were mainly detected using sodium sulfate. Sulfide production was also affected depending on the electron donor used, with the highest production obtained using formate. In contrast, low sulfide production (acetate-containing cultures was associated with an increase in the population of Firmicutes. These results suggested that marine Desulfovibrio species, to be further isolated, are potential candidates for bioremediation of PG by immobilizing metals and metalloids thanks to sulfide production by these SRB.

  14. Reduction of orthophosphates loss in agricultural soil by nano calcium sulfate.

    Chen, Dong; Szostak, Paul; Wei, Zongsu; Xiao, Ruiyang

    2016-01-01

    Nutrient loss from soil, especially phosphorous (P) from farmlands to natural water bodies via surface runoff or infiltration, have caused significant eutrophication problems. This is because dissolved orthophosphates are usually the limiting nutrient for algal blooms. Currently, available techniques to control eutrophication are surprisingly scarce. Calcium sulfate or gypsum is a common soil amendment and has a strong complexation to orthophosphates. The results showed that calcium sulfate reduced the amount of water extractable P (WEP) through soil incubation tests, suggesting less P loss from farmlands. A greater decrease in WEP occurred with a greater dosage of calcium sulfate. Compared to conventional coarse calcium sulfate, nano calcium sulfate further reduced WEP by providing a much greater specific surface area, higher solubility, better contact with the fertilizer and the soil particles, and superior dispersibility. The enhancement of the nano calcium sulfate for WEP reduction is more apparent for a pellet- than a powdered- fertilizer. At the dosage of Ca/P weight ratio of 2.8, the WEP decreased by 31±5% with the nano calcium sulfate compared to 20±5% decrease with the coarse calcium sulfate when the pellet fertilizer was used. Computation of the chemical equilibrium speciation shows that calcium hydroxyapatite has the lowest solubility. However, other mineral phases such as hydroxydicalcium phosphate, dicalcium phosphate dihydrate, octacalcium phosphate, and tricalcium phosphate might form preceding to calcium hydroxyapatite. Since calcium sulfate is the major product of the flue gas desulfurization (FGD) process, this study demonstrates a potential beneficial reuse and reduction of the solid FGD waste. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Efficacy of Submucosal Sodium Tetradecyl Sulfate in the Soft Palate as a Treatment of the Mild Obstructive Sleep Apnea Syndrome: A Pilot Study

    Alberto Labra

    2012-01-01

    Full Text Available Background. As described by Mair et al. in 2001, snoreplasty, the application of sclerosant agents in the palate is a promising and cheap alternative to treat snoring. We decided to try this kind of therapy for the management of mild sleep apnea. Study Design. Experimental, longitudinal, prospective, nonrandomized, self-controlled pilot study. Methods. 11 patients were included, all of them with a polysomnographic study showing an Apnea-Hypopnea Index (AHI from 5 to 20, and with a Müller maneuver showing only retropalatal collapse. Results. We found significant decrease in the number of apneas hypopneas and oxygen desaturation as well as in the snoring index (<0.05, although no differences were found in the number of arousals. Conclusion. Sclerosant agents might become a relevant part in the treatment of sleep apnea, in very well-selected patients.

  16. Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

    Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

    2007-12-15

    Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)

  17. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    2010-04-01

    ... ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a...

  18. Prevalence of contact allergy in the general population: Sensitization to metals with a focus on nickel sulfate, the EDEN Fragrance Study Group

    Schuttelaar, M.-L.; Ofenloch, R.; Bruze, M.; Cazzaniga, S.; Elsner, P.; Gonçalo, M.; Naldi, L.; Svensson, Å.; Diepgen, T.

    2016-01-01

    Sensitization to metals is assessed mostly in clinical populations. Studies in the general population are scarce. Our objective was to determine the prevalence of metal sensitization in the general population and to determine risk factors for nickel sensitization. In five European countries (the

  19. Study of aging and ordering processes in titanium carbide

    Arbuzov, M.P.; Khaenko, B.V.; Kachkovskaya, Eh.T.

    1977-01-01

    Aging and ordering processes in titanium carbide were investigated on monocrystals (fragments of alloys) with the aid of roentgenographic method. The sequence of phase transformations during aging was ascertained,and a monoclinic structure of the carbon atoms ordering is suggested. The microhardness of titanium carbide was studied as a function of the heat treatment of alloys and the main factors (ordering and dislocation structure) which govern the difference in the microhardness of hardened and aged (annealed) specimens were determined

  20. Monitoring sulfide and sulfate-reducing bacteria

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  1. The electrical and thermal properties of sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide

    Imanaka, N.; Yamaguchi, Y.; Adachi, G.; Shiokawa, J.

    1986-01-01

    Sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide was prepared. The thermal and electrical properties of its phases were investigated. The Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 SiO 2 samples are similar to the Na 2 SO 4 -I phase (a high temperature phase), which is appreciably effective for Na + ionic conduction. Phase transformation was considerably suppressed by mixing. Electromotive force (EMF) was measured, using Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 -SiO 2 as a solid electrolyte, by constructing an SO 2 gas concentration cell. The measured EMF's at 823 and 773 K were in fairly good accordance with the calculated EMF's for inlet SO 2 gas concentration between 30 ppm and 1%, and 500 ppm and 0.5% respectively

  2. Interfacial properties of chitosan/sodium dodecyl sulfate complexes

    Milinković Jelena R.

    2017-01-01

    Full Text Available Contemporary formulations of cosmetic and pharmaceutical emulsions may be achieved by using combined polymer/surfactant system, which can form complexes with different structure and physicochemical properties. Such complexation can lead to additional stabilization of the emulsion products. For these reasons, the main goal of this study was to investigate the interfacial properties of chitosan/sodium dodecyl sulfate complexes. In order to understand the stabilization mechanism, the interface of the oil/water systems that contained mixtures of chitosan and sodium dodecyl sulfate, was studied by measuring the interfacial tension. Considering the fact that the properties of the oil phase has influence on the adsorption process, three different types of oil were investigated: medium-chain triglycerides (semi-synthetic oil, paraffin oil (mineral oil and natural oil obtained from the grape seed. The surface tension measurements at the oil/water interface, for chitosan water solutions, indicate a poor surface activity of this biopolymer. Addition of sodium dodecyl sulfate to chitosan solution causes a significant decrease in the interfacial tension for all investigated oils. The results of this study are important for understanding the influence of polymer-surfactant interactions on the properties of the solution and stability of dispersed systems. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III46010

  3. Heparan sulfate-chondroitin sulfate hybrid proteoglycan of the cell surface and basement membrane of mouse mammary epithelial cells

    David, G.; Van den Berghe, H.

    1985-01-01

    Chondroitin sulfate represents approximately 15% of the 35 SO 4 -labeled glycosaminoglycans carried by the proteoglycans of the cell surface and of the basolateral secretions of normal mouse mammary epithelial cells in culture. Evidence is provided that these chondroitin sulfate-carrying proteoglycans are hybrid proteoglycans, carrying both chondroitin sulfate and heparan sulfate chains. Complete N-desulfation but limited O-desulfation, by treatment with dimethyl sulfoxide, of the proteoglycans decreased the anionic charge of the chondroitin sulfate-carrying proteoglycans to a greater extent than it decreased the charge of their constituent chondroitin sulfate chains. Partial depolymerization of the heparan sulfate residues of the proteoglycans with nitrous acid or with heparin lyase also reduced the effective molecular radius of the chondroitin sulfate-carrying proteoglycans. The effect of heparin lyase on the chondroitin sulfate-carrying proteoglycans was prevented by treating the proteoglycan fractions with dimethyl sulfoxide, while the effect of nitrous acid on the dimethyl sulfoxide-treated proteoglycans was prevented by acetylation. This occurrence of heparan sulfate-chondroitin sulfate hybrid proteoglycans suggests that the substitution of core proteins by heparan sulfate or chondroitin sulfate chains may not solely be determined by the specific routing of these proteins through distinct chondroitin sulfate and heparan sulfate synthesizing mechanisms. Moreover, regional and temporal changes in pericellular glycosaminoglycan compositions might be due to variable postsynthetic modification of a single gene product

  4. Sulfation in lead-acid batteries

    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.

  5. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entactin...

  6. Sulfate accumulation in a sea breeze/land breeze circulation system

    Cass, Glen R.; Shair, Frederick H.

    1984-01-01

    An atmospheric tracer study using SF_6 was conducted on July 22, 1977, to examine the origin of the high particulate sulfate concentrations observed in coastal Los Angeles County. It was found that the sea breeze/land breeze circulation system in the Los Angeles Basin both increases the retention time for sulfate formation in the marine environment and causes individual air parcels to make multiple passes over large coastal emissions sources. Day-old sulfur oxides emissions advected out to se...

  7. Pengaruh Penambahan Sodium Lauril Sulfat (Sls) Sebagai Surfaktan Terhadap Sifat Fisik Dan Uji Disolusi Tablet Ketoprofen

    Pratama, Adithya Wahyu; Siswanto, Agus; Suparman, Suparman

    2012-01-01

    Ketoprofen (acid 2-(3-benzoilfenil) propanoat) was derivated of propionat acid which has analgesic, antipyretic, and anti-inflammatory with poor solubillity in water. This research allowed to increase the dissolution rate of ketoprofen tablets and effect on the physical characteristic by adding sodium lauril sulfat as surfactant. Sodium lauryl sulfat is a surfactant that can be used to improve wetting and dissolution rate. This study was done with make four formula of ketoprofen tablets by d...

  8. Verification of Sulfate Attack Penetration Rates for Saltstone Disposal Unit Modeling

    Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-12

    Recent Special Analysis modeling of Saltstone Disposal Units consider sulfate attack on concrete and utilize degradation rates estimated from Cementitious Barriers Partnership software simulations. This study provides an independent verification of those simulation results using an alternative analysis method and an independent characterization data source. The sulfate penetration depths estimated herein are similar to the best-estimate values in SRNL-STI-2013-00118 Rev. 2 and well below the nominal values subsequently used to define Saltstone Special Analysis base cases.

  9. Synthesis of highly anti-HIV active sulfated poly- and oligo-saccharides and analysis of their action mechanisms by NMR [nuclear magnetic resonance] spectroscopy

    Uryu, Toshiyuki

    1998-01-01

    We have been synthesizing sulfated polysaccharides and oligosaccharides with highly anti-HIV (human immunodeficiency virus) activities. It has been known that sulfated polysaccharides such as dextran sulfate and pentosan polysulfate have biological activities such as anticoagulant activity and recently anti-HIV activity. Curdlan sulfate having 1,3-β-linked glucan backbone had high anti-HIV activity but low anticoagulant activity. Phase I/II test for the curdlan sulfate as an AIDS (acquired immunodeficiency syndrome) drug was carried out in the United States. In this study, regioselectivity sulfatec curdlan sulfates were prepared in order to study effects of sulfate groups and conformation of curdlan sulfates. In addition, action mechanisms of curdlan sulfate as anti-AIDS drug and of heparin as an anticoagulant were examined by means of NMR spectroscopy. 1. Structure dependence of anti-HIV and anticoagulant activities of sulfated polysaccharides. Curdlan with M n 9000 was regioselectively sulfated on its hydroxyl groups at 6, 4, and 2 positions. Those were a curdlan sulfate 62S in which 100% of 6-OH, and about 50% of 2-OH was sulfated, a curdlan sulfate 42S in which 4- and 2-OH's were sulfated, and a curdlan sulfate in which 6, 4, and 2-OH's were partially sulfated. All curdlan sulfates had very high anti-HIV activities exhibited by the drug concentration of 50% inhibition of infection, i.e., EC 50 of 0.04 - 0.25 μg/mL. However, there was almost no difference in the activity among the samples. Therefore, it was revealed that the degree of sulfation and putative conformation of the curdlan sulfates but not the position of sulfate groups have large effects on the anti-HIV activity. On the other hand, the anticoagulant activity increased with increasing molecular weight of the curdlan sulfates. As a result, it is assumed that the size of reaction sites of the virus protein reacting with curdlan sulfate is different from that of the proteins related to anticoagulant

  10. Sulfate Reduction and Thiosulfate Transformations in a Cyanobacterial Mat during a Diel Oxygen Cycle

    JØRGENSEN, BB

    1994-01-01

    Bacterial sulfate reduction and transformations of thiosulfate were studied with radiotracers in a Microcoleus chthono-plastes-dominated microbial mat growing in a hypersaline pond at the Red Sea. The study showed how a diel cycle of oxygen evolution affected respiration by sulfate-reducing bacte......Bacterial sulfate reduction and transformations of thiosulfate were studied with radiotracers in a Microcoleus chthono-plastes-dominated microbial mat growing in a hypersaline pond at the Red Sea. The study showed how a diel cycle of oxygen evolution affected respiration by sulfate......-reducing bacteria and the metabolism of thiosulfate through oxidative and reductive pathways. Sulfate reduction occurred in both oxic and anoxic layers of the mat and varied diurnally, apparently according to temperature rather than to oxygen. Time course experiments showed that the radiotracer method...... underestimated sulfate reduction in the oxic zone due to rapid reoxidation of the produced sulfide. Extremely high reduction rates of up to 10 mu mol cm(-3) d(-1) were measured just below the euphotic zone. Although thiosulfate was simultaneously oxidized, reduced and disproportionated by bacteria in all layers...

  11. Sulfates as chromophores for multiwavelength photoacoustic imaging phantoms

    Fonseca, Martina; An, Lu; Beard, Paul; Cox, Ben

    2017-12-01

    As multiwavelength photoacoustic imaging becomes increasingly widely used to obtain quantitative estimates, the need for validation studies conducted on well-characterized experimental phantoms becomes ever more pressing. One challenge that such studies face is the design of stable, well-characterized phantoms and absorbers with properties in a physiologically realistic range. This paper performs a full experimental characterization of aqueous solutions of copper and nickel sulfate, whose properties make them close to ideal as chromophores in multiwavelength photoacoustic imaging phantoms. Their absorption varies linearly with concentration, and they mix linearly. The concentrations needed to yield absorption values within the physiological range are below the saturation limit. The shape of their absorption spectra makes them useful analogs for oxy- and deoxyhemoglobin. They display long-term photostability (no indication of bleaching) as well as resistance to transient effects (no saturable absorption phenomena), and are therefore suitable for exposure to typical pulsed photoacoustic light sources, even when exposed to the high number of pulses required in scanning photoacoustic imaging systems. In addition, solutions with tissue-realistic, predictable, and stable scattering can be prepared by mixing sulfates and Intralipid, as long as an appropriate emulsifier is used. Finally, the Grüneisen parameter of the sulfates was found to be larger than that of water and increased linearly with concentration.

  12. Producing ammonium sulfate from flue gas desulfurization by-products

    Chou, I.-Ming; Bruinius, J.A.; Benig, V.; Chou, S.-F.J.; Carty, R.H.

    2005-01-01

    Emission control technologies using flue gas desulfurization (FGD) have been widely adopted by utilities burning high-sulfur fuels. However, these technologies require additional equipment, greater operating expenses, and increased costs for landfill disposal of the solid by-products produced. The financial burdens would be reduced if successful high-volume commercial applications of the FGD solid by-products were developed. In this study, the technical feasibility of producing ammonium sulfate from FGD residues by allowing it to react with ammonium carbonate in an aqueous solution was preliminarily assessed. Reaction temperatures of 60, 70, and 80??C and residence times of 4 and 6 hours were tested to determine the optimal conversion condition and final product evaluations. High yields (up to 83%) of ammonium sulfate with up to 99% purity were achieved under relatively mild conditions. The optimal conversion condition was observed at 60??C and a 4-hour residence time. The results of this study indicate the technical feasibility of producing ammonium sulfate fertilizer from an FGD by-product. Copyright ?? Taylor & Francis Inc.

  13. Neutral sodium/bicarbonate/sulfate hot waters in geothermal systems

    Mahon, W.A.J. (Dept. of Industrial and Scientific Research, Wairakei, New Zealand); Klyen, L.E.; Rhode, M.

    1980-03-01

    The least understood thermal water is a near neutral water which contains varying amounts of bicarbonate and sulfate as the major anions, low concentrations of chloride (< 30 ppM) and sodium as the major cation. In the past this water has been referred to as a sodium bicarbonate water but present studies suggest that the quantities of bicarbonate and sulfate in this water type are frequently of the same order. Of particular interest is the distribution and position of the sodium/bicarbonate/sulfate water in the same and different systems. Many hot springs in Indonesia, for example, discharge water of this composition. Present studies indicate that this water type can originate from high temperature reservoirs which form the secondary steam heated part of a normal high temperature geothermal system. The hydrological conditions producing these waters in geothermal systems are investigated and the relationship between the water type and vapor dominated systems is discussed. It is suggested that the major water type occurring in the so called vapor dominated parts of geothermal systems is this water. The water does not simply represent steam condensate, rather it consists essentially of meteoric water which has been steam heated. The water composition results from the interaction of carbon dioxide and hydrogen sulfide with meteoric water and the rocks confining this water in the aquifer.

  14. DISTRIBUTION OF GBM HEPARAN-SULFATE PROTEOGLYCAN CORE PROTEIN AND SIDE-CHAINS IN HUMAN GLOMERULAR-DISEASES

    VANDENBORN, J; VANDENHEUVEL, LPWJ; BAKKER, MAH; VEERKAMP, JH; ASSMANN, KJM; WEENING, JJ; BERDEN, JHM

    Using monoclonal antibodies (mAbs) recognizing either the core protein or the heparan sulfate (HS) side chain of human GBM heparan sulfate proteoglycan (HSPG), we investigated their glomerular distribution on cryostat sections of human kidney tissues. The study involved 95 biopsies comprising twelve

  15. Community structure and activity of sulfate-reducing bacteria in an intertidal surface sediment: a multi-method approach

    Llobet-Brossa, E.; Rabus, R.; Böttcher, M.

    2002-01-01

    by the presence of acid-volatile sulfides (AVS, essentially iron monosulfide). Stable sulfur isotope discrimination between dissolved sulfate and AVS was dominated by sulfate reduction. The diversity of SRB was studied using denaturant gradient gel electrophoresis of 16S rDNA, phospholipid fatty acid analysis...

  16. Prevalence of contact allergy to metals in the European general population with a focus on nickel sulfate and piercings: The EDEN Fragrance Study.

    Schuttelaar, Marie L A; Ofenloch, Robert F; Bruze, Magnus; Cazzaniga, Simone; Elsner, Peter; Gonçalo, Margarida; Naldi, Luigi; Svensson, Åke; Diepgen, Thomas L

    2018-04-10

    Studies on sensitization to metals in the general population are scarce. To determine the prevalence of sensitization to metals in the general population, and factors associated with nickel sensitization. In 5 European countries (The Netherlands, Germany, Italy, Portugal and Sweden), a random sample (N = 3119) from the general population (aged 18-74 years) was patch tested and interviewed by use of a questionnaire on exposure to metals, piercing, and jewellery. Overall, the age-standardized prevalences of sensitization to nickel, cobalt and chromium were, respectively, 14.5%, 2.1%, and 0.8%. The highest prevalence of nickel sensitization was seen in Portugal (18.5%) and the lowest (8.3%) in Sweden. The prevalence of cobalt sensitization varied between 3.8% (The Netherlands) and 0.9% (Italy), and the prevalence of chromium sensitization varied between 1.3% (Portugal) and 0.2% (Sweden). Significant associations were observed between nickel allergy and female sex (odds ratio [OR] 5.19; 95% confidence interval [95%CI]: 3.99-6.74), past piercing use (OR 3.86; 95%CI: 2.85-5.24), and currently having ≥3 piercings (OR 5.58; 95%CI: 4.02-7.76). The prevalence of sensitization to metals in the European general population was high, mostly because of nickel. The lowest prevalence of contact allergy to nickel and chromium observed in Sweden supports the effectiveness of long-standing regulation. © 2018 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.

  17. Sulfated glycopeptide nanostructures for multipotent protein activation

    Lee, Sungsoo S.; Fyrner, Timmy; Chen, Feng; Álvarez, Zaida; Sleep, Eduard; Chun, Danielle S.; Weiner, Joseph A.; Cook, Ralph W.; Freshman, Ryan D.; Schallmo, Michael S.; Katchko, Karina M.; Schneider, Andrew D.; Smith, Justin T.; Yun, Chawon; Singh, Gurmit; Hashmi, Sohaib Z.; McClendon, Mark T.; Yu, Zhilin; Stock, Stuart R.; Hsu, Wellington K.; Hsu, Erin L.; Stupp , Samuel I. (NWU)

    2017-06-19

    Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

  18. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    Ozuolmez, Derya; Na, Hyunsoo; Lever, Mark A; Kjeldsen, Kasper U; Jørgensen, Bo B; Plugge, Caroline M

    2015-01-01

    Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744), a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria.

  19. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    Derya eOzuolmez

    2015-05-01

    Full Text Available Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744, a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria.

  20. Evaluation of commercial and sulfated ZrO_2 aiming application catalysis

    Silva, F.N.; Dantas, J.; Costa, A.C.F.M.; Pallone, E.M.J.A.; Dutra, R.C.L.

    2014-01-01

    This study evaluates the performance of commercial and sulfated ZrO_2 for future application in catalysis. Commercial ZrO_2 was provided by the company Saint-Gobain Zirpro. The sulfation occurred with SO_4"-"2 ion content of 30% compared to the mass of ZrO_2. The samples were characterized by XRD, FTIR, EDX and GD. The results revealed the formation of a monoclinic phase for the commercial sample, and a monoclinic major phase with tetragonal traces for the sulfated sample. The commercial ZrO_2 showed a narrow, bimodal and asymmetric agglomerates distribution, while the sulfated sample showed a narrow, tetramodal and asymmetric agglomerates distribution. The presence of traces of the tetragonal phase in the SO_4"-"2/ZrO_2 XRD, and the presence of SO_3 in the EDX were good indicators for future use in catalysis to provide ester. (author)

  1. Oxygen Reduction Reaction on PtCo Nanocatalyst: (Bi)sulfate Anion Poisoning

    Liu, Jie; Huang, Yan

    2018-05-01

    Pt alloy electrocatalysts are susceptible to anion adsorption in the working environment of fuel cells. In this work, the unavoidable bisulfate and sulfate ((bi)sulfate) poisoning of the oxygen reduction reaction (ORR) on a common PtCo nanocatalyst was studied by the rotating disk electrode (RDE) technique, for the first time to the best of our knowledge. The specific activity decreases linearly with the logarithm of (bi)sulfate concentration under various high potentials. This demonstrates that the (bi)sulfate adsorption does not affect the free energy of ORR activation at a given potential. Moreover, it is speculated that these two conditions, the adsorption of one O2 molecule onto two Pt sites and this adsorption as a rate-determining step of ORR reaction, are unlikely to exist simultaneously.

  2. Sulfate metabolites as alternative markers for the detection of 4-chlorometandienone misuse in doping control.

    Balcells, Georgina; Gómez, Cristina; Garrostas, Lorena; Pozo, Óscar J; Ventura, Rosa

    2017-07-01

    Sulfate metabolites have been described as long-term metabolites for some anabolic androgenic steroids (AAS). 4-chlorometandienone (4Cl-MTD) is one of the most frequently detected AAS in sports drug testing and it is commonly detected by monitoring metabolites excreted free or conjugated with glucuronic acid. Sulfation reactions of 4Cl-MTD have not been studied. The aim of this work was to evaluate the sulfate fraction of 4Cl-MTD metabolism by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to establish potential long-term metabolites valuable for doping control purposes. 4Cl-MTD was administered to two healthy male volunteers and urine samples were collected up to 8 days after administration. A theoretical selected reaction monitoring (SRM) method working in negative mode was developed. Ion transitions were based on ionization and fragmentation behaviour of sulfate metabolites as well as specific neutral losses (NL of 15 Da and NL of 36 Da) of compounds with related chemical structure. Six sulfate metabolites were detected after the analysis of excretion study samples. Three of the identified metabolites were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). Results showed that five out of the six identified sulfate metabolites were detected in urine up to the last collected samples from both excretion studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Formation of the natural sulfate aerosol

    Kerminen, V.M.; Hillamo, R.; Maekinen, M.; Virkkula, A.; Maekelae, T.; Pakkanen, T. [Helsinki Univ. (Finland). Dept. of Physics

    1996-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  4. Formation of the natural sulfate aerosol

    Kerminen, V M; Hillamo, R; Maekinen, M; Virkkula, A; Maekelae, T; Pakkanen, T [Helsinki Univ. (Finland). Dept. of Physics

    1997-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  5. Sulfate Storage and Stability on Common Lean NOx Trap Components

    Ottinger, Nathan A [ORNL; Toops, Todd J [ORNL; Pihl, Josh A [ORNL; Roop, Justin T [ORNL; Choi, Jae-Soon [ORNL; Partridge Jr, William P [ORNL

    2012-01-01

    Components found in a commercial lean NO{sub x} trap have been studied in order to determine their impact on sulfate storage and release. A micro-reactor and a diffuse reflectance infrared Fourier transform spectrometer (DRIFTS) were used to compare components MgAl{sub 2}O{sub 4}, Pt/MgAl{sub 2}O{sub 4}, Pt/Al{sub 2}O{sub 3}, Pt/Ba/Al{sub 2}O{sub 3}, Pt/CeO{sub 2}-ZrO{sub 2}, and Pt/Ba/CeO{sub 2}-ZrO{sub 2}, as well as physical mixtures of Pt/Al{sub 2}O{sub 3} + MgAl{sub 2}O{sub 4} and Pt/Ba/CeO{sub 2}-ZrO{sub 2} + MgAl{sub 2}O{sub 4}. Desulfation temperature profiles as well as DRIFTS NO{sub x} and SO{sub x} storage spectra are presented for all components. This systematic approach highlighted the ability of the underlying support to impact sulfate stability, in particular when Ba was supported on ceria-zirconia rather than alumina the desulfation temperature decreased by 60-120 C. A conceptual model of sulfation progression on the ceria-zirconia support is proposed that explains the high uptake of sulfur and low temperature release when it is employed. It was also determined that the close proximity of platinum is not necessary for much of the sulfation and desulfation chemistry that occurs, as physical mixtures with platinum dispersed on only one phase displayed similar behavior to samples with platinum dispersed on both phases.

  6. Performance evaluation and microbial community analysis of the function and fate of ammonia in a sulfate-reducing EGSB reactor.

    Wang, Depeng; Liu, Bo; Ding, Xinchun; Sun, Xinbo; Liang, Zi; Sheng, Shixiong; Du, Lingfeng

    2017-10-01

    Ammonia is widely distributed in sulfate-reducing bioreactor dealing with sulfate wastewater, which shows potential effect on the metabolic pathway of sulfate and ammonia. This study investigates the sulfate-reducing efficiency and microbial community composition in the sulfate-reducing EGSB reactor with the increasing ammonia loading. Results indicated that, compared with low ammonia loading (166-666 mg/L), the sulfate and organic matter removal efficiencies were improved gradually with the appropriate ammonia loading (1000-2000 mg/L), which increased from 63.58 ± 3.81 to 71.08 ± 1.36% and from 66.24 ± 1.32 to 81.88 ± 1.83%, respectively. Meanwhile, with the appropriate ratio of ammonia and sulfate (1.5-3.0) and hydraulic retention time (21 h), the sulfate-reducing anaerobic ammonia oxidation (SRAO) process was occurred efficiently, inducing the accumulation of S 0 (270 mg/L) and the simultaneous ammonia removal (70.83%) in EGSB reactor. Moreover, the key sulfate-reducing bacteria (SRB) (Desulfovibrio) and denitrification bacteria (Pseudomonas and Alcaligenes) were responsible for the sulfate and nitrogen removal in these phases, which accounted for 3.66-5.54 and 3.85-9.13%, respectively. However, as the ammonia loading higher than 3000 mg/L (phases 9 and 10), the sulfate-reducing efficiency was decreased to only 28.3 ± 1.26% with the ammonia removal rate of 18.4 ± 3.37% in the EGSB reactor. Meanwhile, the predominant SRB in phases 9 and 10 were Desulfomicrobium (1.22-1.99%) and Desulfocurvus (4.0-5.46%), and the denitrification bacteria accounted for only 0.88% (phase 10), indicating the low nitrogen removal rate.

  7. Molecular dissection of placental malaria protein VAR2CSA interaction with a chemo-enzymatically synthesized chondroitin sulfate library.

    Sugiura, Nobuo; Clausen, Thomas Mandel; Shioiri, Tatsumasa; Gustavsson, Tobias; Watanabe, Hideto; Salanti, Ali

    2016-12-01

    Placental malaria, a serious infection caused by the parasite Plasmodium falciparum, is characterized by the selective accumulation of infected erythrocytes (IEs) in the placentas of the pregnant women. Placental adherence is mediated by the malarial VAR2CSA protein, which interacts with chondroitin sulfate (CS) proteoglycans present in the placental tissue. CS is a linear acidic polysaccharide composed of repeating disaccharide units of D-glucuronic acid and N-acetyl-D-galactosamine that are modified by sulfate groups at different positions. Previous reports have shown that placental-adhering IEs were associated with an unusually low sulfated form of chondroitin sulfate A (CSA) and that a partially sulfated dodecasaccharide is the minimal motif for the interaction. However, the fine molecular structure of this CS chain remains unclear. In this study, we have characterized the CS chain that interacts with a recombinant minimal CS-binding region of VAR2CSA (rVAR2) using a CS library of various defined lengths and sulfate compositions. The CS library was chemo-enzymatically synthesized with bacterial chondroitin polymerase and recombinant CS sulfotransferases. We found that C-4 sulfation of the N-acetyl-D-galactosamine residue is critical for supporting rVAR2 binding, whereas no other sulfate modifications showed effects. Interaction of rVAR2 with CS is highly correlated with the degree of C-4 sulfation and CS chain length. We confirmed that the minimum structure binding to rVAR2 is a tri-sulfated CSA dodecasaccharide, and found that a highly sulfated CSA eicosasaccharide is a more potent inhibitor of rVAR2 binding than the dodecasaccharides. These results suggest that CSA derivatives may potentially serve as targets in therapeutic strategies against placental malaria.

  8. Inhibition of sulfate reduction in paddy soils

    Vamos, R

    1958-12-13

    The hydrogen sulfide formed in waterlogged soils is a serious problem in rice cultivation. It inhibits the uptake of water and nutrients and may even cause root-rot. Results can best be obtained by preventing the formation of hydrogen sulfide. It is formed mainly by reduction of sulfate for which the cellulose-butyric acid fermentation provides the hydrogen source. Addition of ammonium or potassium nitrate prevents the formation of H/sub 2/S. The hydrogen produced by butyric acid fermentation is used to reduce nitrate and consequently cannot be utilized by the sulfate-reducing bacteria as a source of energy. 6 references.

  9. Mast Cells Produce a Unique Chondroitin Sulfate Epitope.

    Farrugia, Brooke L; Whitelock, John M; O'Grady, Robert; Caterson, Bruce; Lord, Megan S

    2016-02-01

    The granules of mast cells contain a myriad of mediators that are stored and protected by the sulfated glycosaminoglycan (GAG) chains that decorate proteoglycans. Whereas heparin is the GAG predominantly associated with mast cells, mast cell proteoglycans are also decorated with heparan sulfate and chondroitin sulfate (CS). This study investigated a unique CS structure produced by mast cells that was detected with the antibody clone 2B6 in the absence of chondroitinase ABC digestion. Mast cells in rodent tissue sections were characterized using toluidine blue, Leder stain and the presence of mast cell tryptase. The novel CS epitope was identified in rodent tissue sections and localized to cells that were morphologically similar to cells chemically identified as mast cells. The rodent mast cell-like line RBL-2H3 was also shown to express the novel CS epitope. This epitope co-localized with multiple CS proteoglycans in both rodent tissue and RBL-2H3 cultured cells. These findings suggest that the novel CS epitope that decorates mast cell proteoglycans may play a role in the way these chains are structured in mast cells. © 2016 The Histochemical Society.

  10. Sulfated Polysaccharides in the Freshwater Green Macroalga Cladophora surera Not Linked to Salinity Adaptation.

    Arata, Paula X; Alberghina, Josefina; Confalonieri, Viviana; Errea, María I; Estevez, José M; Ciancia, Marina

    2017-01-01

    The presence of sulfated polysaccharides in cell walls of seaweeds is considered to be a consequence of the physiological adaptation to the high salinity of the marine environment. Recently, it was found that sulfated polysaccharides were present in certain freshwater Cladophora species and some vascular plants. Cladophora (Ulvophyceae, Chlorophyta) is one of the largest genera of green algae that are able to grow in both, seas and freshwater courses. Previous studies carried out on the water-soluble polysaccharides of the marine species C. falklandica established the presence of sulfated xylogalactoarabinans constituted by a backbone of 4-linked β-L-arabinopyranose units partially sulfated mainly on C3 and also on C2 with partial glycosylation, mostly on C2, with terminal β-D-xylopyranose or β-D-galactofuranose units. Besides, minor amounts of 3-, 6- and/or 3,6-linked β-D-galactan structures, with galactose in the pyranosic form were detected. In this work, the main water soluble cell wall polysaccharides from the freshwater alga Cladophora surera were characterized. It was found that this green alga biosynthesizes sulfated polysaccharides, with a structure similar to those found in marine species of this genus. Calibration of molecular clock with fossil data suggests that colonization of freshwater environments occurred during the Miocene by its ancestor. Therefore, the presence of sulfated polysaccharides in the freshwater green macroalga C. surera could be, in this case, an adaptation to transient desiccation and changes in ionic strength. Retention of sulfated polysaccharides at the cell walls may represent a snapshot of an evolutionary event, and, thus constitutes an excellent model for further studies on the mechanisms of sulfation on cell wall polysaccharides and environmental stress co-evolution.

  11. Sulfated Polysaccharides in the Freshwater Green Macroalga Cladophora surera Not Linked to Salinity Adaptation

    Paula X. Arata

    2017-11-01

    Full Text Available The presence of sulfated polysaccharides in cell walls of seaweeds is considered to be a consequence of the physiological adaptation to the high salinity of the marine environment. Recently, it was found that sulfated polysaccharides were present in certain freshwater Cladophora species and some vascular plants. Cladophora (Ulvophyceae, Chlorophyta is one of the largest genera of green algae that are able to grow in both, seas and freshwater courses. Previous studies carried out on the water-soluble polysaccharides of the marine species C. falklandica established the presence of sulfated xylogalactoarabinans constituted by a backbone of 4-linked β-L-arabinopyranose units partially sulfated mainly on C3 and also on C2 with partial glycosylation, mostly on C2, with terminal β-D-xylopyranose or β-D-galactofuranose units. Besides, minor amounts of 3-, 6- and/or 3,6-linked β-D-galactan structures, with galactose in the pyranosic form were detected. In this work, the main water soluble cell wall polysaccharides from the freshwater alga Cladophora surera were characterized. It was found that this green alga biosynthesizes sulfated polysaccharides, with a structure similar to those found in marine species of this genus. Calibration of molecular clock with fossil data suggests that colonization of freshwater environments occurred during the Miocene by its ancestor. Therefore, the presence of sulfated polysaccharides in the freshwater green macroalga C. surera could be, in this case, an adaptation to transient desiccation and changes in ionic strength. Retention of sulfated polysaccharides at the cell walls may represent a snapshot of an evolutionary event, and, thus constitutes an excellent model for further studies on the mechanisms of sulfation on cell wall polysaccharides and environmental stress co-evolution.

  12. Sulfur cycling in contaminated aquifers: What can we learn from oxygen isotopes in sulfate? (Invited)

    Knoeller, K.; Vogt, C.; Hoth, N.

    2009-12-01

    Bacterial reduction of dissolved sulfate (BSR) is a key process determining the natural attenuation in many contaminated aquifers. For example, in groundwater bodies affected by acid mine drainage (AMD) BSR reduces the contaminant load by producing alkalinity and facilitating a sustainable fixation of sulfur in the sediment. In aquifers contaminated with petroleum hydrocarbons sulfate may act as a terminal electron acceptor for the anaerobic oxidation of the organic contaminants to carbon dioxide and water. Due to the isotope selectivity of sulfate reducing bacteria, BSR shows the most pronounced isotope fractionation within the sulfur cycle. While sulfur displays a straightforward kinetic enrichment in the residual sulfate described by the enrichment factor epsilon (ɛ), the mechanism of oxygen isotope fractionation is still being discussed controversially. Nevertheless, it is agreed on that oxygen isotope exchange between ambient water and residual sulfate occurs during BSR in natural environments. With respect to this potential isotope exchange, the fractionation parameter theta (θ) is introduced instead of the kinetic enrichment factor epsilon (ɛ). The dual isotope system considering both sulfate-sulfur and sulfate-oxygen isotope fractionation and the respective fractionation parameters ɛ and θ provides an excellent tool for the recognition and quantification of BSR. Beyond that, the dual isotope approach may help identify and estimate interfering sulfur transformations such as re-oxidation and disproportionation processes which is especially vital for the understanding of the overall natural attenuation potential of the investigated aquifers. We present two examples from different field studies showing the benefits of applying the combination of sulfur and oxygen isotopes in dissolved sulfate to reveal the details of the sulfur cycle. The first case study is concerned with the evaluation of the potential for BSR in an AMD-affected aquifer close to an

  13. Trace methane oxidation and the methane dependency of sulfate reduction in anaerobic granular sludge

    Meulepas, Roel J.W.

    2010-05-01

    This study investigates the oxidation of labeled methane (CH4) and the CH4 dependence of sulfate reduction in three types of anaerobic granular sludge. In all samples, 13C-labeled CH4 was anaerobically oxidized to 13C-labeled CO2, while net endogenous CH4 production was observed. Labeled-CH4 oxidation rates followed CH4 production rates, and the presence of sulfate hampered both labeled-CH4 oxidation and methanogenesis. Labeled-CH4 oxidation was therefore linked to methanogenesis. This process is referred to as trace CH4 oxidation and has been demonstrated in methanogenic pure cultures. This study shows that the ratio between labeled-CH4 oxidation and methanogenesis is positively affected by the CH4 partial pressure and that this ratio is in methanogenic granular sludge more than 40 times higher than that in pure cultures of methanogens. The CH4 partial pressure also positively affected sulfate reduction and negatively affected methanogenesis: a repression of methanogenesis at elevated CH4 partial pressures confers an advantage to sulfate reducers that compete with methanogens for common substrates, formed from endogenous material. The oxidation of labeled CH 4 and the CH4 dependence of sulfate reduction are thus not necessarily evidence of anaerobic oxidation of CH4 coupled to sulfate reduction. © 2010 Federation of European Microbiological Societies.

  14. Effects of the addition of micro silica on the durability of mortars exposed to the sodium sulfate attack

    Nasser, C.; Meriam, M.

    2012-01-01

    This article presents a detailed experimental study on the sulfate attack of mortars of self compacting concrete, and the effectiveness of employs micro silica and limestone fillers in the minimization of the damage resulting from such an attack. The test solution used to supply the sulfate ions and the cations was the sodium sulfate solution 4.5%. The solution saturated with lime was employed as the reference solution. The main variables investigated in the study were the type of cement and mineral addition. The expansion measured on p rims of mortar of (40x40x160) millimeters was employed to estimate their durability after exposure to the sodium sulfate solution attack during 91 days-Specimens of mortars were visually examined to assess the extent of deterioration due to the sulfate attack. The x-ray diffraction was used to evaluate the microstructural nature of the sulfate attack. The test results proved that the use of micro silica had a beneficial effect on the expansion due to the sodium sulfate attack. While mortars with limestone filler have undergoes degradation even with the use of cement resistant to sulfates. (authors).

  15. Activation and transfer of sulfate in biological systems (1960); Activation biologique du sulfate et son transfert (1960)

    Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    It examines in this review the successive stages of active sulfate formation and its role in biological synthesis of sulfuric esters. The possible role of active sulfate as intermediary in sulfate reduction is also discussed. (author) [French] On examine dans cette etude les stades successifs de la mise en evidence du sulfate actif, son role dans la formation des esters sulfuriques de natures diverses, ainsi que sa participation eventuelle comme intermediaire au cours de la reduction du sulfate. On decrit aussi un procede de preparation du systeme biologique, generateur du sulfate actif et une methode de synthese chimique. (auteur)

  16. Cloud albedo changes in response to anthropogenic sulfate and non-sulfate aerosol forcings in CMIP5 models

    L. Frey

    2017-07-01

    Full Text Available The effects of different aerosol types on cloud albedo are analysed using the linear relation between total albedo and cloud fraction found on a monthly mean scale in regions of subtropical marine stratocumulus clouds and the influence of simulated aerosol variations on this relation. Model experiments from the Coupled Model Intercomparison Project phase 5 (CMIP5 are used to separately study the responses to increases in sulfate, non-sulfate and all anthropogenic aerosols. A cloud brightening on the month-to-month scale due to variability in the background aerosol is found to dominate even in the cases where anthropogenic aerosols are added. The aerosol composition is of importance for this cloud brightening, that is thereby region dependent. There is indication that absorbing aerosols to some extent counteract the cloud brightening but scene darkening with increasing aerosol burden is generally not supported, even in regions where absorbing aerosols dominate. Month-to-month cloud albedo variability also confirms the importance of liquid water content for cloud albedo. Regional, monthly mean cloud albedo is found to increase with the addition of anthropogenic aerosols and more so with sulfate than non-sulfate. Changes in cloud albedo between experiments are related to changes in cloud water content as well as droplet size distribution changes, so that models with large increases in liquid water path and/or cloud droplet number show large cloud albedo increases with increasing aerosol. However, no clear relation between model sensitivities to aerosol variations on the month-to-month scale and changes in cloud albedo due to changed aerosol burden is found.

  17. Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

    Miletto, M.; Williams, K.H.; N' Guessan, A.L.; Lovley, D.R.

    2011-04-01

    Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to

  18. Efflorescent sulfates from Baia Sprie mining area (Romania) — Acid mine drainage and climatological approach

    Buzatu, Andrei; Dill, Harald G.; Buzgar, Nicolae; Damian, Gheorghe; Maftei, Andreea Elena; Apopei, Andrei Ionuț

    2016-01-01

    The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30–90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

  19. Efflorescent sulfates from Baia Sprie mining area (Romania)--Acid mine drainage and climatological approach.

    Buzatu, Andrei; Dill, Harald G; Buzgar, Nicolae; Damian, Gheorghe; Maftei, Andreea Elena; Apopei, Andrei Ionuț

    2016-01-15

    The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30-90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A., E-mail: jimfield@email.arizona.edu

    2016-11-05

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu{sup 2+} as stable sulfide mineral. • Cu{sup +2} removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H{sub 2}SO{sub 4} and Cu{sup 2+}. Sulfate, sulfide, Cu{sup 2+} and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO{sub 4}{sup 2−} d{sup −1}) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu{sup 2+} removal were observed in the endogenous control. In algae amended-columns, Cu{sup 2+} was precipitated with biogenic H{sub 2}S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.