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Sample records for ruthenium 99

  1. Volatility of ruthenium-106, technetium-99, and iodine-129, and the evolution of nitrogen oxide compounds during the calcination of high-level, radioactive nitric acid waste

    SciTech Connect

    Rimshaw, S.J.; Case, F.N.; Tompkins, J.A.

    1980-02-01

    The nitrate anion is the predominant constituent in all high-level nuclear wastes. Formic acid reacts with the nitrate anion to yield noncondensable, inert gases (N/sub 2/ or N/sub 2/O), which can be scrubbed free of /sup 106/Ru, /sup 129/I, and /sup 99/Tc radioactivities prior to elimination from the plant by passing through HEPA filters. Treatment of a high-level authentic radioactive waste with two moles of formic acid per mole of nitrate anion leads to a low RuO/sub 4/ volatility of about 0.1%, which can be reduced to an even lower level of 0.007% on adding a 15% excess of formic acid. Without pretreatment of the nitrate waste with formic acid, a high RuO/sub 4/ volatility of approx. 35% is observed on calcining a 4.0 N HNO/sub 3/ solution in quartz equipment at 350/sup 0/C. The RuO/sub 4/ volatility falls to approx. 1.0% on decreasing the initial HNO/sub 3/ concentration to 1.0 N or lower. It is postulated that thermal denitration of a highly nitrated ruthenium complex leads to the formation of volatile RuO/sub 4/, while decarboxylation of a ruthenium-formate complex leads to the formation of nonvolatile RuO/sub 2/. Wet scrubbing with water is used to remove RuO/sub 4/ from the off-gas stream. In all glass equipment, small amounts of particulate RuO/sub 2/ are formed in the gas phase by decomposition of RuO/sub 4/. The /sup 99/Tc volatility was found to vary from 0.2 to 1.4% on calcining HNO/sub 3/ and HCOOH (formic acid) solutions over the temperature range of 250 to 600/sup 0/C. These unexpectedly low volatilities of /sup 99/Tc are correlated to the high thermal stability limits of various metal pertechnetates and technetates. Iodine volatilities were high, varying from a low of 30% at 350/sup 0/C to a high of 97% at 650/sup 0/C. It is concluded that with a proper selection of pretreatment and operating conditions the /sup 106/Ru and /sup 99/Tc activities can be retained in the calcined solid with recycle of the wet scrubbing solution.

  2. RECOVERY OF RUTHENIUM VALUES

    DOEpatents

    Grummitt, W.E.; Hardwick, W.H.

    1961-01-01

    A process is given for the recovery of ruthenium from its aqueous solutions by oxidizing the ruthenium to the octavalent state and subsequently extracting the ruthenium into a halogen-substituted liquid paraffin.

  3. Radiochemistry of ruthenium

    SciTech Connect

    Schulz, W W; Metcalf, S G; Barney, G S

    1984-06-01

    Information on ruthenium is presented. Topics include the following; isotopes and nuclear properties of ruthenium; review of the chemistry of ruthenium including metal and alloys, compounds of ruthenium, and solution chemistry; separation methods including volatilization of RuO{sub 4}, precipitation and coprecipitation, solvent extraction, chromatographic techniques, and analysis for radioruthenium. 445 refs., 7 figs., 23 tabs.

  4. Metals fact sheet: Ruthenium

    SciTech Connect

    1996-06-01

    Ruthenium, named after Ruthenia, a province in Western Russia, was discovered in 1827 by Osann in placer ores from Russia`s Ural mountains. A minor platinum group metal (PGM), Ruthenium was the last of the PGMs to be isolated. In 1844, Klaus prepared the first 6 grams of pure ruthenium metal.

  5. Synthesis of ruthenium hydride

    NASA Astrophysics Data System (ADS)

    Kuzovnikov, M. A.; Tkacz, M.

    2016-02-01

    Ruthenium hydride was synthesized at a hydrogen pressure of about 14 GPa in a diamond-anvil cell. Energy-dispersive x-ray diffraction was used to monitor the ruthenium crystal structure as a function of hydrogen pressure up to 30 GPa. The hydride formation was accompanied by phase transition from the original hcp structure of the pristine metal to the fcc structure. Our results confirmed the theoretical prediction of ruthenium hydride formation under hydrogen pressure. The standard Gibbs free energy of the ruthenium hydride formation reaction was calculated assuming the pressure of decomposition as the equilibrium pressure.

  6. SOLVENT EXTRACTION OF RUTHENIUM

    DOEpatents

    Hyman, H.H.; Leader, G.R.

    1959-07-14

    The separation of rathenium from aqueous solutions by solvent extraction is described. According to the invention, a nitrite selected from the group consisting of alkali nitrite and alkaline earth nitrite in an equimolecular quantity with regard to the quantity of rathenium present is added to an aqueous solution containing ruthenium tetrantrate to form a ruthenium complex. Adding an organic solvent such as ethyl ether to the resulting mixture selectively extracts the rathenium complex.

  7. Special Issue on Ruthenium Complexes.

    PubMed

    Dragutan, Ileana; Dragutan, Valerian; Demonceau, Albert

    2017-02-08

    The organic chemistry of ruthenium has been one of the most vigorously growing research areas over the past decades. Considerable effort has been extended towards the design and application of a broad series of ruthenium complexes, which culminated with the development by Ryoji Noyori (2001 Nobel Prize for Chemistry) of chiral ruthenium catalysts for stereoselective hydrogenation reactions [1], and the discovery by Robert H. Grubbs (2005 Nobel Prize for Chemistry) of well-defined ruthenium- benzylidene catalysts for olefin metathesis [2] [...].

  8. Contamination from 131I, 103Ru, and 239Np in the eluate of 99Mo-99mTc generators loaded with (n, gamma)-produced 99Mo.

    PubMed

    Billinghurst, M W; Hreczuch, F W

    1976-09-01

    Iodine-131, ruthenium-103, and neptunium-239 are present as contaminants in the eluate of 99Mo-99mTc generators loaded with 99Mo prepared by thermal-neutron irradiation of enriched 98Mo. The elution pattern of each of these contaminants is determined, together with the amounts found in the eluate of all generators tested over a 7-month period.

  9. RUTHENIUM DECONTAMINATION METHOD

    DOEpatents

    Gresky, A.T.

    1960-07-19

    A liquid-liquid extraction method of separating uranium from fission products is given. A small amount of a low molecular weight ketone is added to an acidic aqueous solution containing neutron-irradiated uranium and its associated fission products. The resulting solution is digested and then contacted with an organic liquid that extracts uranium values. The purpose of the step of digesting the aqueous solution in the presence of the ketone is to suppress the extractability of ruthenium.

  10. SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Callis, C.F.; Moore, R.L.

    1959-09-01

    >The separation of ruthenium from aqueous solutions containing uranium plutonium, ruthenium, and fission products is described. The separation is accomplished by providing a nitric acid solution of plutonium, uranium, ruthenium, and fission products, oxidizing plutonium to the hexavalent state with sodium dichromate, contacting the solution with a water-immiscible organic solvent, such as hexone, to extract plutonyl, uranyl, ruthenium, and fission products, reducing with sodium ferrite the plutonyl in the solvent phase to trivalent plutonium, reextracting from the solvent phase the trivalent plutonium, ruthenium, and some fission products with an aqueous solution containing a salting out agent, introducing ozone into the aqueous acid solution to oxidize plutonium to the hexavalent state and ruthenium to ruthenium tetraoxide, and volatizing off the ruthenium tetraoxide.

  11. Moderated ruthenium fischer-tropsch synthesis catalyst

    DOEpatents

    Abrevaya, Hayim

    1991-01-01

    The subject Fischer-Tropsch catalyst comprises moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  12. Characterization And Dissolution Properties Of Ruthenium Oxides

    EPA Science Inventory

    Ruthenium oxides (RuO2•1.10H2O and RuO2) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation ...

  13. SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Beederman, M.; Vogler, S.; Hyman, H.H.

    1959-07-14

    The separation of rathenium from a rathenium containing aqueous solution is described. The separation is accomplished by adding sodium nitrite, silver nitrate and ozone to the ruthenium containing aqueous solution to form ruthenium tetroxide and ihen volatilizing off the ruthenium tetroxide.

  14. Characterization And Dissolution Properties Of Ruthenium Oxides

    EPA Science Inventory

    Ruthenium oxides (RuO2•1.10H2O and RuO2) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation ...

  15. Ruthenium complexes as antimicrobial agents.

    PubMed

    Li, Fangfei; Collins, J Grant; Keene, F Richard

    2015-04-21

    One of the major advances in medical science has been the development of antimicrobials; however, a consequence of their widespread use has been the emergence of drug-resistant populations of microorganisms. There is clearly a need for the development of new antimicrobials--but more importantly, there is the need for the development of new classes of antimicrobials, rather than drugs based upon analogues of known scaffolds. Due to the success of the platinum anticancer agents, there has been considerable interest in the development of therapeutic agents based upon other transition metals--and in particular ruthenium(II/III) complexes, due to their well known interaction with DNA. There have been many studies of the anticancer properties and cellular localisation of a range of ruthenium complexes in eukaryotic cells over the last decade. However, only very recently has there been significant interest in their antimicrobial properties. This review highlights the types of ruthenium complexes that have exhibited significant antimicrobial activity and discusses the relationship between chemical structure and biological processing--including site(s) of intracellular accumulation--of the ruthenium complexes in both bacterial and eukaryotic cells.

  16. The influence of ruthenium on vascular tone.

    PubMed

    Pauwels, Bart; Boydens, Charlotte; Van de Voorde, Johan

    2015-09-01

    Over the past few years, ruthenium has been under attention for development of organometallic drugs with various therapeutic applications. Because of its favourable characteristics, ruthenium is perfectly suitable for drug design. Ruthenium-containing complexes exert a wide range of biological effects. However, so far, the influence of ruthenium itself on vascular tone has never been studied. The effect of ruthenium was analysed through organ bath studies measuring isometric tension on mice thoracic aorta. After obtaining a stable contraction plateau, cumulative concentration-response curves of the ruthenium-compounds (RuCl3 , Ruthenium Red, [RuCl2 (CO)3 ]2 and RuCl2 (DMSO)4 ) (30-600 μmol/l) were performed. The effect of RuCl3 after contraction with different contractile agents was evaluated. Furthermore, the influence of ruthenium-containing molecules on endogenous (acetylcholine) and exogenous (sodium nitroprusside) NO-mediated relaxations was determined. All studied ruthenium compounds elicit, to some extent, a decrease of the contraction level. Looking further into the underlying mechanism, we found that RuCl3 relaxes aortic rings only when contracted with norepinephrine. This RuCl3 -induced relaxation can be prevented by the antioxidants ascorbic acid and N-acetyl L-cysteine. In addition, ruthenium compounds may diminish acetylcholine- or sodium nitroprusside-induced relaxations. Ruthenium-containing molecules can influence vascular tone induced by norepinephrine due to oxidative inactivation. Moreover, they can undermine NO-mediated responses. This should be considered when developing ruthenium-containing drugs. © 2015 Royal Pharmaceutical Society.

  17. Nitric oxide-releasing ruthenium nanoparticles.

    PubMed

    Ho, Chi-Ming; Liao, Kai-Jun; Lok, Chun-Nam; Che, Chi-Ming

    2011-10-14

    Nitric oxide-releasing ruthenium nanoparticles were synthesized by the reaction of alkanethiolate-protected ruthenium nanoparticles with tert-butyl nitrite ((t)BuONO), and their water-soluble derivatives are able to deliver NO to proteins such as reduced myoglobin upon light irradiation in aqueous media.

  18. IR-doped ruthenium oxide catalyst for oxygen evolution

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I. (Inventor); Narayanan, Sekharipuram R. (Inventor)

    2012-01-01

    A method for preparing a metal-doped ruthenium oxide material by heating a mixture of a doping metal and a source of ruthenium under an inert atmosphere. In some embodiments, the doping metal is in the form of iridium black or lead powder, and the source of ruthenium is a powdered ruthenium oxide. An iridium-doped or lead-doped ruthenium oxide material can perform as an oxygen evolution catalyst and can be fabricated into electrodes for electrolysis cells.

  19. Electronic Transitions of Ruthenium Monoxide

    NASA Astrophysics Data System (ADS)

    Wang, Na; Ng, Y. W.; Cheung, A. S.-C.

    2013-06-01

    The electronic transition spectrum of ruthenium monoxide (RuO) molecule in the spectral region between 545nm to 640nm has been recorded and analyzed using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The RuO molecule was produced by reacting laser- ablated ruthenium atoms with N_{2}O seeded in argon. Nine vibrational bands were recorded and they are identified to be belonging to four electronic transition systems, namely the [18.1]Ω = 4 - X^{5} Δ_4 transition, [16.0]^{5} Φ_5 - X^{5} Δ_4 transition, [18.1]Ω = 3 - X^{5} Δ_3, and [15.8] ^{5} Φ_4 - X^{5} Δ_3 transition. RuO has been determined to have a X^{5} Δ_4 ground state. A least squares fit of the measured rotational lines yielded molecular constants for the ground and the low-lying electronic states. A molecular orbital energy level diagram has been used to help with the assignment of the observed electronic states.

  20. Luminescent tetrametallic complexes of ruthenium

    SciTech Connect

    Murphy, W.R. Jr.; Brewer, K.J.; Gettliffe, G.; Petersen, J.D. )

    1989-01-11

    Tetrametallic complexes constructed around the metal core Ru(dpp){sub 3}{sup 2+} (where dpp = 2,3-bis(2-pyridyl)pyrazine) have been prepared and characterized. The complexes, which have the general formula Ru((dpp)ML{sub 2}){sub 3}{sup n+}, where ML{sub 2} = Ru{sup II}(bpy){sub 2} (n = 8), Ru{sup II}(phen){sub 2} (n = 8), and Ru{sup II}(tpy)Cl (n = 5) and bpy = 2,2{prime}-bipyridine, phen = 1,10-phenanthroline, and tpy = 2,2{prime}:6{prime},2{double prime}-terpyridine, are prepared from the reaction of Ru(dpp){sub 3}{sup 2+} with ML{sub 2}Cl{sub 2} in ethanol/water. The tetrametallic complexes luminesce at room temperature in acetonitrile with emissions characteristic of a single ruthenium center with excited-state lifetimes in the 100-ns range. Electrochemically, the most facile reductions occur at the dpp ligand, and the lower energy oxidation is a single peak associated with the three peripheral ruthenium centers. 13 refs., 1 fig., 2 tabs.

  1. Ruthenium Sesquisilicide: A Promising Thermoelectric Material

    NASA Technical Reports Server (NTRS)

    Vining, Cronin B.

    1993-01-01

    Report describes experimental investigation of thermoelectric properties of ruthenium sesquisilicide (RU2Si3). Suggests suitably doped Ru2Si3 could have thermoelectric figures of merit two or more times as large as SiGe.

  2. Platinum-ruthenium-palladium fuel cell electrocatalyst

    DOEpatents

    Gorer, Alexander

    2006-02-07

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum at a concentration that is between about 20 and about 60 atomic percent, ruthenium at a concentration that is between about 20 and about 60 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having an atomic ratio of platinum to ruthenium that is between about 0.7 and about 1.2. Alternatively, the catalyst may contain platinum at a concentration that is between about 25 and about 50 atomic percent, ruthenium at a concentration that is between about 25 and about 55 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having a difference between the concentrations of ruthenium and platinum that is no greater than about 20 atomic percent.

  3. Platinum-ruthenium-nickel fuel cell electrocatalyst

    DOEpatents

    Gorer, Alexander

    2005-07-26

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum, ruthenium, and nickel, wherein the nickel is at a concentration that is less than about 10 atomic percent.

  4. Lead-ruthenium pyrochlores as oxygen electrocatalysts

    NASA Technical Reports Server (NTRS)

    Anderson, E. B.; Taylor, E. J.; Moniz, G. A.

    1990-01-01

    An investigation of lead-ruthenium pyrochlores of the structure Pb2(Ru/2-x/Pb/x/) O7-y for use as oxygen electrocatalysts in alkaline media is discussed. Lead-ruthenium pyrochlore mixed metal oxides were prepared and characterized by X-ray diffraction, BET surface area, dry powder conductivity, and chemical stability. Gas diffusion electrodes were developed specifically for the lead-ruthenium pyrochlore materials. Also investigated were the effects of varying electrode fabrication parameters on the oxygen reduction performance of the lead-ruthenium pyrochlore electrocatalyst. Long-term stability performance was also evaluated. The oxygen reduction performance of the pyrochlore electrocatalyst is considerably higher than that of the state-of-the-art gold-platinum alloy electrocatalyst currently used by NASA. Furthermore, the pyrochlore electrocatalysts are attractive candidates for high-performance pressurized alkaline fuel cells.

  5. Lead-ruthenium pyrochlores as oxygen electrocatalysts

    NASA Technical Reports Server (NTRS)

    Anderson, E. B.; Taylor, E. J.; Moniz, G. A.

    1990-01-01

    An investigation of lead-ruthenium pyrochlores of the structure Pb2(Ru/2-x/Pb/x/) O7-y for use as oxygen electrocatalysts in alkaline media is discussed. Lead-ruthenium pyrochlore mixed metal oxides were prepared and characterized by X-ray diffraction, BET surface area, dry powder conductivity, and chemical stability. Gas diffusion electrodes were developed specifically for the lead-ruthenium pyrochlore materials. Also investigated were the effects of varying electrode fabrication parameters on the oxygen reduction performance of the lead-ruthenium pyrochlore electrocatalyst. Long-term stability performance was also evaluated. The oxygen reduction performance of the pyrochlore electrocatalyst is considerably higher than that of the state-of-the-art gold-platinum alloy electrocatalyst currently used by NASA. Furthermore, the pyrochlore electrocatalysts are attractive candidates for high-performance pressurized alkaline fuel cells.

  6. Cationic ruthenium alkylidene catalysts bearing phosphine ligands.

    PubMed

    Endo, Koji; Grubbs, Robert H

    2016-02-28

    The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(i) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelating Ph2P(CH2)nPPh2 (n = 2 or 3) ligated cationic catalysts. The structures of these newly reported catalysts feature unique geometries caused by ligation of the bulky phosphine ligands. Their activities and selectivities in standard metathesis reactions were also investigated. These cationic ruthenium alkylidene catalysts reported here showed moderate activity and very similar stereoselectivity when compared to the second generation ruthenium dichloride catalyst in ring-closing metathesis, cross metathesis, and ring-opening metathesis polymerization assays.

  7. Photonastic effects in ruthenium sulfoxide polymers

    NASA Astrophysics Data System (ADS)

    Rack, Jeffrey J.; Livshits, Maksim Y.; Shin, Jisoo

    2016-09-01

    We have established that film morphology and laser induced heating from dye absorption are important parameters in the creation of new photonastic materials. Photonastic is defined as regular, repeatable movement in a pre-programmed direction following exposure to light. This work builds upon the development of photonastic polymers of ruthenium sulfoxide complexes, where the action of bending is ascribed to phototriggered isomerization of a sulfoxide ligand in a ruthenium coordination complex that is covalently attached to polynorbornene. The bending is analyzed in terms of a bilayer cantilever model.

  8. Bis(Dioxolene)(Bipyridine)Ruthenium Redox Series

    DTIC Science & Technology

    1988-07-11

    reactions with isosbestic points were generally observed in these redox processes. The electronic spectra of 02, 01, S, RI and R2 are shown Tor the (1...oOFFICE OF NAVAL RESEARCH Contract NOOOl4-84-G-0201 Task No. 0051-865 Technical Report *23 Bis(Dioxolene)(Bipyridine)Ruthenium Redox Series By...Classit’.’-tion) Bix(Dioxolene)(Bipyridine)Ruthenium Redox Series 12 PERSON4AL AUTHOR(S) A.B. P. Lever*, Pamela R. &uburn, Elaine S. Dodsworth, Masa-A

  9. Decarboxylation of cinnamic acids by ruthenium sawhorses

    USDA-ARS?s Scientific Manuscript database

    The ruthenium sawhorse has proven effective in the conversion of trans-cinnamic acid, and substituted trans-cinnamic acids, giving an effective source of biobased styrene and styrene analogs. The reaction is especially versatile, as it achieves product without utilizing co-reagents. However, the opt...

  10. Thermodynamic properties of gaseous ruthenium species.

    PubMed

    Miradji, Faoulat; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2015-05-21

    The review of thermodynamic data of ruthenium oxides reveals large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. The reaction energies leading to the formation of ruthenium oxides RuO, RuO2, RuO3, and RuO4 have been calculated for a series of reactions. The combination of different quantum chemical methods has been investigated [DFT, CASSCF, MRCI, CASPT2, CCSD(T)] in order to predict the geometrical parameters, the energetics including electronic correlation and spin-orbit coupling. The most suitable method for ruthenium compounds is the use of TPSSh-5%HF for geometry optimization, followed by CCSD(T) with complete basis set (CBS) extrapolations for the calculation of the total electronic energies. SO-CASSCF seems to be accurate enough to estimate spin-orbit coupling contributions to the ground-state electronic energies. This methodology yields very accurate standard enthalpies of formations of all species, which are either in excellent agreement with the most reliable experimental data or provide an improved estimate for the others. These new data will be implemented in the thermodynamical databases that are used by the ASTEC code (accident source term evaluation code) to build models of ruthenium chemistry behavior in severe nuclear accident conditions. The paper also discusses the nature of the chemical bonds both from molecular orbital and topological view points.

  11. Ruthenium-Ruthenium-Bonded [Bis{corrolato-ruthenium(III)}](n) (n=0, +1, -1) Complexes: Model Compounds for the Photosynthetic Special Pair.

    PubMed

    Sinha, Woormileela; Sommer, Michael G; Hettmanczyk, Lara; Patra, Bratati; Filippou, Vasileios; Sarkar, Biprajit; Kar, Sanjib

    2017-02-16

    We present herein the synthesis of three new bis(corrolato-ruthenium(III)) complexes containing unsupported Ru-Ru bonds and their characterization in different redox states. The (1) H NMR spectra of the bis(corrolato-ruthenium(III)) complexes displayed "normal" chemical shifts and the compounds proved to be EPR-silent. Crystallographic characterization of the dimers indicated Ru-Ru distances of 2.175 Å, consistent with a triple bond between the two ruthenium centers. All of the synthesized complexes undergo two successive reversible oxidations and a single reversible reduction. A combination of UV/Vis/NIR/EPR spectroelectrochemical studies and DFT calculations established the redox state distributions in these ruthenium-ruthenium-bonded dimers. Whereas reduction of the dimers is metal-based and leads to metal-metal-bonded mixed-valent Ru(II) -Ru(III) species, one-electron oxidation largely retains the Ru(III) -Ru(III) situation with the generation of metal-bound corrolato radicals. The present study thus concerns the first UV/Vis/NIR/EPR spectroelectrochemical characterization and DFT calculations of ruthenium-ruthenium-bonded rotationally ordered corrole dimers. The mean plane separation between the two corrole units in these dimers is around 3.543 Å, which is in close agreement to that in the "special pair" in chlorophyll. Oxidation of these ruthenium-ruthenium-bonded dimers gives rise to two new electronic absorption bands in the NIR region (similar to those of the special pair), which have apparently not been mentioned/observed in earlier reports on ruthenium-ruthenium-bonded corrole dimers. These bands mainly originate from inter-corrole transitions.

  12. Asymmetric reduction of ketones by biocatalysis using clementine mandarin (Citrus reticulata) fruit grown in Annaba or by ruthenium catalysis for access to both enantiomers.

    PubMed

    Bennamane, Manhel; Zeror, Saoussen; Aribi-Zouioueche, Louisa

    2015-03-01

    Biocatalytic reduction of prochiral ketones using freshly ripened clementine mandarin (Citrus reticulata) in aqueous medium is reported. High enantioselectivities were observed, especially for the bioreduction of indanone , tetralone , and thiochromanone with respectively 95%, 99%, and 86% enantiomeric excess (ee). Enantioselective bio- and metal-catalyzed reactions were compared. Chiral ruthenium catalysts afforded good asymmetric inductions (>75% ee) in most cases, enantiomeric excesses depending on the nature of substrate and ligand. N-aminoindanol prolinamide was revealed as the best ligand for most ketones. Interestingly, for several substrates both enantiomers could be obtained using either Citrus reticulata or ruthenium complex.

  13. Enantioselective syntheses of sulfoxides in octahedral ruthenium(II) complexes via a chiral-at-metal strategy.

    PubMed

    Li, Zheng-Zheng; Wen, A-Hao; Yao, Su-Yang; Ye, Bao-Hui

    2015-03-16

    The preparation of chiral 2-(alkylsulfinyl)phenol compounds by enantioselective coordination-oxidation of the thioether ruthenium complexes with a chiral-at-metal strategy has been developed. The enantiomerically pure sulfoxide complexes Δ-[Ru(bpy)2{(R)-LO-R}](PF6) (bpy is 2,2'-bipyridine, HLO-R is 2-(alkylsulfinyl)phenol, R = Me (Δ-1a), Et (Δ-2a), iPr (Δ-3a), Bn (Δ-4a), and Nap (Δ-5a)) and Λ-[Ru(bpy)2{(S)-LO-R}](PF6) (R = Me (Λ-1a), Et (Λ-2a), iPr (Λ-3a), Bn (Λ-4a), and Nap (Λ-5a)) have been synthesized by the reaction of Δ-[Ru(bpy)2(py)2](2+) or Λ-[Ru(bpy)2(py)2](2+) with the prochiral thioether ligands 2-(alkylthio)phenol (HL-R), followed by enantioselective oxidation with m-CPBA as oxidant. The X-ray crystallography was used to verify the stereochemistry of ruthenium complexes and sulfur atoms. The configurations of the ruthenium complexes are stable during the coordination and oxidation reactions. Moreover, the chiral sulfoxide ligands are enantioselectively generated by controlling of the configuration of ruthenium centers in the course of oxidation reaction. That is, the Λ configuration at the ruthenium center generates the S sulfoxide ligand; on the contrary, the Δ configuration of the ruthenium complex originates the R sulfoxide ligand. Acidolysis of Λ-[Ru(bpy)2{(R)-LO-R}](PF6) and Δ-[Ru(bpy)2{(S)-LO-R}](PF6) complexes in the presence of TFA-MeCN afforded the chiral ligands (R)-HLO-R and (S)-HLO-R in 96-99% ee values, respectively. Importantly, the chiral ruthenium complexes can be recycled as Δ/Λ-[Ru(bpy)2(MeCN)2](PF6)2 and reused in a next reaction cycle with complete retention of the configurations at ruthenium centers.

  14. The biokinetics of ruthenium in the human body.

    PubMed

    Leggett, R W

    2012-03-01

    The International Commission on Radiological Protection (ICRP) is updating its biokinetic and dosimetric models for workers and subsequently will revisit its models for members of the public. This paper summarises the biokinetic database for ruthenium and proposes a new biokinetic model for systemic ruthenium. In contrast to the ICRP's current model, the proposed model depicts recycling of ruthenium between tissues and blood and a non-uniform distribution of systemic ruthenium. The paper also points out inconsistencies between the ICRP's respiratory model for RuO(4) vapour and reported data, and inconsistencies between the ICRP's default gastrointestinal (GI) uptake value and data for some forms of ruthenium. Dosimetric implications of the proposed systemic model and the findings for inhaled RuO(4) vapour and GI uptake of ruthenium are examined.

  15. Radionuclide Basics: Technetium-99

    EPA Pesticide Factsheets

    Technetium-99 (chemical symbol Tc-99) is a silver-gray, radioactive metal. It occurs naturally in very small amounts in the earth's crust, but is primarily man-made. Technetium-99m is a short-lived form of Tc-99 that is used as a medical diagnostic tool.

  16. Transient photocyclization in ruthenium(ii) polypyridine complexes of indolamines.

    PubMed

    Carrone, G; Zayat, L; Slep, L D; Etchenique, R

    2017-01-18

    Ruthenium polypyridine complexes have proved to be useful caging groups for visible-light photodelivery of biomolecules. In most photoreactions, one ligand is expelled upon irradiation, yielding ruthenium mono-aqua complexes and no other photoproduct. In this work we show that a long-lived transient photoproduct is generated when the ruthenium complexes involve indolamines. The spatial conformation of this species is compatible with a cyclic structure that contains both the amine and the normally non-coordinating aromatic ring coordinated to the ruthenium center.

  17. Use of specific antibody to demonstrate glycocalyx, K99 pili, and the spatial relationships of K99+ enterotoxigenic Escherichia coli in the ileum of colostrum-fed calves.

    PubMed Central

    Chan, R; Acres, S D; Costerton, J W

    1982-01-01

    The attachment of enterotoxigenic Escherichia coli (ETEC) strain B44 (O9:K30:K99:F41:H-) to the ileal epithelium of newborn colostrum-fed calves was studied by electron microscopy. Stabilization of the bacterial glycocalyx (K30) and pili (K99) by fixation of tissue sections in specific antibody and staining with ruthenium red were used so that the bacterial surface structures could be clearly visualized and their spatial relationship to the intestinal brush border defined. When sections of ileum from infected calves were neither fixed in antibody nor stained with ruthenium red, the ETEC cells colonizing the small intestine were separated from each other and from the brush border by an electron-translucent halo; neither the glycocalyx nor the pili could be clearly resolved. When ruthenium red staining was used, the halo was partially filled by a net of electron-dense fibers composed of pili and condensed glycocalyx which extended to the brush border. Tissue sections reacted with anti-K30 antibody before staining with ruthenium red revealed microcolonies of ETEC surrounded by a discrete electron-dense glycocalyx 0.3 to 1.0 micrometers thick and in tight contact with the epithelial cell surface. When ileal tissue was treated with K99 antibody, the K99 pili were visible as discrete fibers extending from the bacterial cell surface through the glycocalyx. We discuss the role of these cell surface components in pathogenic adhesion and in the formation of protected microcolonies at the surface of the infected ileal epithelium. Images PMID:6127313

  18. The biokinetics of ruthenium in the human body

    SciTech Connect

    Leggett, Richard Wayne

    2011-01-01

    The biokinetics of ruthenium (Ru) in the human body is of interest due mainly to the potential for occupational or environmental exposure to 106Ru (T1/2 = 373.6 d) and 103Ru (T1/2 = 39.3 d), which typically represent a significant portion of the fission products in a reactor inventory. During reactor operations or nuclear fuel reprocessing these ruthenium isotopes may be present as ruthenium tetroxide (RuO4) vapor, a highly mobile form of ruthenium that has been involved in a number of cases of accidental exposure to 106Ru or 103Ru. This paper summarizes the biokinetic database for ruthenium and proposes a new respiratory model for inhaled RuO4 vapor, a new biokinetic for systemic (absorbed) ruthenium, and material-specific gastrointestinal absorption fractions for ruthenium. The proposed respiratory model for RuO4 differs from the current ICRP model mainly in that it depicts slower clearance of deposited activity from the respiratory tract and lower absorption to blood than depicted in the current ICRP model. The proposed systemic biokinetic model depicts more realistic paths of movement of absorbed ruthenium in the body than the current ICRP model and, in contrast to the present model, a less uniform distribution of systemic activity. Implications of the proposed models with regard to inhalation and ingestion dose coefficients for 106Ru are examined.

  19. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, H.

    1990-07-31

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation. 1 fig.

  20. Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst

    DOEpatents

    Abrevaya, Hayim

    1990-01-01

    A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

  1. Ruthenium(II) Complexes as Potential Apoptosis Inducers in Chemotherapy.

    PubMed

    Zheng, Kangdi; Wu, Qiong; Wang, Chengxi; Tan, Weijun; Mei, Wenjie

    2017-01-01

    Herein, the development of ruthenium complexes as potential apoptosis inducers, as well as their underlying mechanism has been reviewed. In recent years, various ruthenium complexes have been designed and their in vitro and in vivo inhibitory activities against various types of tumor cells have been evaluated extensively. It's demonstrated that ruthenium complexes can induce apoptosis of tumor cells through the signal pathway of mitochondria-mediated, death receptor-mediated, and/or endoplasmic reticulum (ER) stress pathways. Alternately, the binding behavior of these ruthenium(II) complexes with DNA, especially with Gquadruplex DNA may play a key role in the DNA damage of tumor cells, and thus provides a versatile tool to rational design novel ruthenium complexes with high activity and selectivity.

  2. Side-on bound diazene and hydrazine complexes of ruthenium.

    PubMed

    Field, Leslie D; Li, Hsiu L; Dalgarno, Scott J

    2010-07-05

    The reaction of cis-[RuCl(2)(PP)(2)] (PP = depe, dmpe) with hydrazine afforded end-on bound ruthenium(II) hydrazine complexes. Treatment of the hydrazine complexes with strong base afforded the side-on bound ruthenium(0) diazene complexes cis-[Ru(eta(2)-NH=NH)(PP)(2)]. Treatment of cis-[Ru(eta(2)-NH=NH)(depe)(2)] with weak acid under chloride-free conditions afforded the side-on bound hydrazine complex cis-[Ru(eta(2)-N(2)H(4))(depe)(2)](2+). These are the first reported side-on bound diazene and hydrazine complexes of ruthenium, and they have been characterized by NMR spectroscopy ((1)H, (31)P, (15)N) and by X-ray crystallography. The interconversion between the ruthenium diazene and the ruthenium hydrazine by acid-base treatment was reversible.

  3. Application of ruthenium catalyzed oxidation of [tris(2-aminoethyl)amine] in trace determination of ruthenium in environmental water samples

    NASA Astrophysics Data System (ADS)

    Prasad, Surendra; Naik, Radhey M.; Srivastava, Abhishek

    2008-10-01

    The ruthenium catalyzed oxidation of tris(2-aminoethyl)amine (TREN) by hexacyanoferrate(III) has been utilized for the development of a new and sensitive catalytic kinetic method (CKM) for the determination of ruthenium(III). The reaction was followed spectrophotometrically by the decrease in absorbance at 420 nm ( λmax of [Fe(CN) 6] 3-). The CKM developed utilizes fixed time procedure under optimum reaction conditions where the change in absorbance (Δ At) versus ruthenium(III) concentrations is plotted. The calibration curve recommended for the method is linear in the concentration range 10.11-252.67 ng ml -1 with very good accuracy and reproducibility and a maximum error 2.20%. The detection limits of the method for ruthenium(III) corresponding to 10, 15 and 20 min are 8.02, 5.03 and 3.15 ng ml -1, respectively. The ruthenium(III) has also been determined in the presence of several other interfering and non-interfering cations and anions and no foreign ions interfered in the determination of ruthenium(III) up to five-fold higher concentration of the foreign ions tested. The method is highly sensitive, selective and stable. It has successfully been applied for the determination of trace ruthenium(III) in some synthetic and environmental water samples. A review of most of the published catalytic kinetic and some other important methods for the determination of ruthenium has also been presented.

  4. Characterization and dissolution properties of ruthenium oxides.

    PubMed

    Luxton, Todd P; Eick, Matthew J; Scheckel, Kirk G

    2011-07-01

    Ruthenium oxides (RuO(2)·1·10H(2)O and RuO(2)) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation state. Surface charging experiments indicate a large quantity of reactive functional groups for both materials and a decrease in the acidity of the surface functional groups with crystallization of the hydrous oxide. Dissolution studies conducted in acidic and basic pH environments indicate Ru-oxides are insoluble in 0.1 M HCl and slightly soluble in 0.1 M NaOH. Oxalate and ascorbate (5 mM) promoted dissolution of RuO(2)·1·10H(2)O demonstrated an increase in dissolution rates with decreasing pH and increasing ligand surface coverage. XPS analysis of the RuO(2)·1·10H(2)O surface after ligand promoted dissolution revealed the reduction of Ru(IV) to Ru(III) indicating that both ascorbate and oxalate reductively dissolve RuO(2)·1·10H(2)O. Dissolution experiments with RuO(2) resulted in dissolution only for 5 mM oxalate at pH 3. Dissolution rates calculated for RuO(2)·1·10H(2)O and RuO(2) are compared with previously published dissolution rates for iron oxides, demonstrating an order of magnitude decrease in the oxalate and ascorbate promoted dissolution. Published by Elsevier Inc.

  5. Ruthenium / aerogel nanocomposits via Atomic Layer Deposition

    SciTech Connect

    Biener, J; Baumann, T F; Wang, Y; Nelson, E J; Kucheyev, S O; Hamza, A V; Kemell, M; Ritala, M; Leskela, M

    2006-08-28

    We present a general approach to prepare metal/aerogel nanocomposites via template directed atomic layer deposition (ALD). In particular, we used a Ru ALD process consisting of alternating exposures to bis(cyclopentadienyl)ruthenium (RuCp{sub 2}) and air at 350 C to deposit metallic Ru nanoparticles on the internal surfaces of carbon and silica aerogels. The process does not affect the morphology of the aerogel template and offers excellent control over metal loading by simply adjusting the number of ALD cycles. We also discuss the limitations of our ALD approach, and suggest ways to overcome these.

  6. Interaction of ruthenium red with Ca2(+)-binding proteins

    SciTech Connect

    Charuk, J.H.; Pirraglia, C.A.; Reithmeier, R.A. )

    1990-07-01

    The interaction of ruthenium red, ((NH3)5Ru-O-Ru(NH3)4-O-Ru(NH3)5)Cl6.4H2O, with various Ca2(+)-binding proteins was studied. Ruthenium red inhibited Ca2+ binding to the sarcoplasmic reticulum protein, calsequestrin, immobilized on Sepharose 4B. Furthermore, ruthenium red bound to calsequestrin with high affinity (Kd = 0.7 microM; Bmax = 218 nmol/mg protein). The dye stained calsequestrin in sodium dodecyl sulfate-polyacrylamide gels or on nitrocellulose paper and was displaced by Ca2+ (Ki = 1.4 mM). The specificity of ruthenium red staining of several Ca2(+)-binding proteins was investigated by comparison with two other detection methods, 45Ca2+ autoradiography and the Stains-all reaction. Ruthenium red bound to the same proteins detected by the 45Ca2+ overlay technique. Ruthenium red stained both the erythrocyte Band 3 anion transporter and the Ca2(+)-ATPase of skeletal muscle sarcoplasmic reticulum. Ruthenium red also stained the EF hand conformation Ca2(+)-binding proteins, calmodulin, troponin C, and S-100. This inorganic dye provides a simple, rapid method for detecting various types of Ca2(+)-binding proteins following electrophoresis.

  7. Dietary pesticides (99.99% all natural).

    PubMed Central

    Ames, B N; Profet, M; Gold, L S

    1990-01-01

    The toxicological significance of exposures to synthetic chemicals is examined in the context of exposures to naturally occurring chemicals. We calculate that 99.99% (by weight) of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are shown to be present in many common foods. We conclude that natural and synthetic chemicals are equally likely to be positive in animal cancer tests. We also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant. PMID:2217210

  8. Dietary pesticides (99. 99% all natural)

    SciTech Connect

    Ames, B.N.; Profet, M.; Gold, L.S. )

    1990-10-01

    The toxicological significance of exposures to synthetic chemicals is examined in the context of exposures to naturally occurring chemicals. The authors calculate that 99.99{percent} (by weight) of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are shown to be present in many common foods. They conclude that natural and synthetic chemicals are equally likely to be positive in animal cancer tests. They also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant.

  9. Decomposition Pathways of Z-Selective Ruthenium Metathesis Catalysts

    PubMed Central

    Herbert, Myles B.; Lan, Yu; Keitz, Benjamin K.; Liu, Peng; Endo, Koji; Day, Michael W.; Houk, K. N.; Grubbs, Robert H.

    2012-01-01

    The decomposition of a Z-selective ruthenium metathesis catalyst and structurally similar analogs has been investigated utilizing X-ray crystallography and density functional theory. Isolated X-ray crystal structures suggest that recently reported C-H activated catalysts undergo decomposition via insertion of the alkylidene moiety into the chelating ruthenium-carbon bond followed by hydride elimination, which is supported by theoretical calculations. The resulting ruthenium hydride intermediates have been implicated in previously observed olefin migration, and thus lead to unwanted byproducts in cross metathesis reactions. Preventing these decomposition modes will be essential in the design of more active and selective Z-selective catalysts. PMID:22500642

  10. PROCESS FOR DECONTAMINATING THORIUM AND URANIUM WITH RESPECT TO RUTHENIUM

    DOEpatents

    Meservey, A.A.; Rainey, R.H.

    1959-10-20

    The control of ruthenium extraction in solvent-extraction processing of neutron-irradiated thorium is presented. Ruthenium is rendered organic-insoluble by the provision of sulfite or bisulfite ions in the aqueous feed solution. As a result the ruthenium remains in the aqueous phase along with other fission product and protactinium values, thorium and uranium values being extracted into the organic phase. This process is particularly applicable to the use of a nitrate-ion-deficient aqueous feed solution and to the use of tributyl phosphate as the organic extractant.

  11. Building Indenylidene-Ruthenium Catalysts for Metathesis Transformations

    NASA Astrophysics Data System (ADS)

    Clavier, Hervé; Nolan, Steven P.

    Ruthenium-mediated olefin metathesis has emerged as an indispensable tool in organic synthesis for the formation carbon-carbon double bonds, attested by the large number of applications for natural product synthesis. Among the numerous catalysts developed to mediate olefin metathesis transformations, ruthenium-indenylidene complexes are robust and powerful pre-catalysts. The discovery of this catalyst category was slightly muddled due to a first mis-assignment of the compound structure. This report provides an overview of the synthetic routes for the construction of the indenylidene pattern in ruthenium complexes. The parameters relating to the indenylidene moiety construction will be discussed as well as the mechanism of this formation

  12. Characteristics and reactivity of ruthenium-oxo complexes.

    PubMed

    Ishizuka, Tomoya; Kotani, Hiroaki; Kojima, Takahiko

    2016-11-14

    In this perspective, we have surveyed the synthetic procedure, characteristics, and reactivity of high-valent ruthenium-oxo complexes. The ruthenium-oxo complexes have served as ideal species to elucidate the characteristics of metal-oxo complexes in terms of not only geometrical and electronic structures but also oxidation reactivity and mechanisms of oxidation reactions. Due to the high stability and excellent reversibility of redox processes, ruthenium-oxo complexes have provided significant mechanistic insights into the oxidation of organic compounds including alcohols, alkenes, and alkanes and also water on the basis of detailed kinetic analysis.

  13. 14 CFR 99.19-99.31 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false 99.19-99.31 Section 99.19-99.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General §§ 99.19-99.31...

  14. 14 CFR 99.19-99.31 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false 99.19-99.31 Section 99.19-99.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General §§ 99.19-99.31 ...

  15. 14 CFR 99.19-99.31 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false 99.19-99.31 Section 99.19-99.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General §§ 99.19-99.31 ...

  16. 14 CFR 99.19-99.31 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false 99.19-99.31 Section 99.19-99.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General §§ 99.19-99.31 ...

  17. 14 CFR 99.19-99.31 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false 99.19-99.31 Section 99.19-99.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General §§ 99.19-99.31 ...

  18. Ruthenium-containing bond coats for thermal barrier coating systems

    NASA Astrophysics Data System (ADS)

    Tryon, B.; Cao, F.; Murphy, K. S.; Levi, C. G.; Pollock, T. M.

    2006-01-01

    Bond coats for zirconia-based thermal barrier coating systems applied to nickel-based superalloys are typically composed of the B2 NiAl phase. Since RuAl has the same B2 crystal structure but a melting point 400°C higher than NiAl, ruthenium-modified aluminide bond coats could provide improved system temperature capability. Creep experiments on ternary Al-Ni-Ru alloys demonstrate greatly improved creep properties with increasing ruthenium content. Processing paths for ruthenium-modified NiAl-based bond coatings have been established within the bounds of commercially available coating systems. The oxidation resistance of ruthenium-modified bond coats during thermal cycling has been examined, and potential thermal barrier coating system implications are discussed.

  19. Effect of ruthenium on nitrogen fixation by some nitrogen fixers.

    PubMed

    Bahadur, K; Gaur, N

    1979-01-01

    The effect of ruthenium chloride in the culture media on the nitrogen-fixing ability of the three nitrogen fixers (unidentified species of Azotobacter, designated here as D3, B3, and B), isolated from Allahabad soil, was studied. It was observed that the nitrogen-fixing ability of the organisms is much increased in presence of 25-75 micro M concentration of ruthenium chloride in the culture media, while sugar consumption remains more or less steady. Also, if mg nitrogen fixed/g carbon consumed in two culture media with successive increasing concentrations of ruthenium chloride is compared by calculating the difference in increase of the amount of nitrogen fixed and carbon consumed in these two culture media, it was observed that high amounts of nitrogen are fixed by B3 and B between 25-50 micro M, and between 50-75 micro M concentration of ruthenium chloride by D3.

  20. Nickel/ruthenium catalyst and method for aqueous phase reactions

    DOEpatents

    Elliott, Douglas C.; Sealock, John L.

    1998-01-01

    A method of hydrogenation using a catalyst in the form of a plurality of porous particles wherein each particle is a support having nickel metal catalytic phase or reduced nickel deposited thereon in a first dispersed phase and an additional ruthenium metal deposited onto the support in a second dispersed phase. The additional ruthenium metal is effective in retarding or reducing agglomeration or sintering of the nickel metal catalytic phase thereby increasing the life time of the catalyst during hydrogenation reactions.

  1. Nonproductive events in ring-closing metathesis using ruthenium catalysts.

    PubMed

    Stewart, Ian C; Keitz, Benjamin K; Kuhn, Kevin M; Thomas, Renee M; Grubbs, Robert H

    2010-06-30

    The relative TONs of productive and nonproductive metathesis reactions of diethyl diallylmalonate are compared for eight different ruthenium-based catalysts. Nonproductive cross metathesis is proposed to involve a chain-carrying ruthenium methylidene. A second more-challenging substrate (dimethyl allylmethylallylmalonate) that forms a trisubstituted olefin product is used to further delineate the effect of catalyst structure on the relative efficiencies of these processes. A steric model is proposed to explain the observed trends.

  2. Fabrication and Characterization of a Ruthenium Nitride Membrane for Electrochemical pH Sensors

    PubMed Central

    Liao, Yi-Hung; Chou, Jung-Chuan

    2009-01-01

    The pH sensing and nonideal characteristics of a ruthenium nitride (RuN) sensing membrane pH sensor were investigated. RuN thin films were deposited from a 99.9% ruthenium target on p-type silicon substrates using radio frequency (r.f.) sputtering with N2 gas. Subsequently, the nanometric structure and surface morphology of RuN thin films were determined. The sensitivity of the RuN sensing membrane pH sensor was 58.03 mV/pH, obtained from ID-VG curves with a current-voltage (I–V) measurement system in standard buffer solutions from pH 1 to pH 13 at room temperature (25 °C). Moreover, the nonideal characteristics of the RuN sensing membrane, such as temperature coefficient, drift with light influence, drift rate and hysteresis width, etc. were also investigated. Finally, the sensing characteristics of the RuN membrane were compared with titanium nitride (TiN), aluminum nitride (AlN) and silicon nitride (Si3N4) membranes. PMID:22574026

  3. Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-substituted alkynes and bicyclic alkenes.

    PubMed

    Goodreid, Jordan; Villeneuve, Karine; Carlson, Emily; Tam, William

    2014-11-07

    Ruthenium-catalyzed asymmetric [2 + 2] cycloadditions between chiral acyl camphorsultam-functionalized alkynes and bicyclic alkenes were examined, providing adducts with complete exo stereoselectivity in good overall yield and enantioselectivity (up to 99% and 166:1, respectively), as well as appreciable diastereoselectivity (up to 163:1). The diastereoselectivity showed dependence on the solvent and temperature, as well as on the substitution pattern of the reacting alkyne and bicyclic alkene components. In general, higher diastereoselectivities were observed for reactions conducted in ethereal solvents and at lower temperatures between N-propynoyl camphorsultams and bicyclic alkenes.

  4. Structural evolution of small ruthenium cluster anions

    SciTech Connect

    Waldt, Eugen; Hehn, Anna-Sophia; Ahlrichs, Reinhart; Kappes, Manfred M.; Schooss, Detlef

    2015-01-14

    The structures of ruthenium cluster anions have been investigated using a combination of trapped ion electron diffraction and density functional theory computations in the size range from eight to twenty atoms. In this size range, three different structural motifs are found: Ru{sub 8}{sup −}–Ru{sub 12}{sup −} have simple cubic structures, Ru{sub 13}{sup −}–Ru{sub 16}{sup −} form double layered hexagonal structures, and larger clusters form close packed motifs. For Ru{sub 17}{sup −}, we find hexagonal close packed stacking, whereas octahedral structures occur for Ru{sub 18}{sup −}–Ru{sub 20}{sup −}. Our calculations also predict simple cubic structures for the smaller clusters Ru{sub 4}{sup −}–Ru{sub 7}{sup −}, which were not accessible to electron diffraction measurements.

  5. A promising new thermoelectric material - Ruthenium silicide

    NASA Technical Reports Server (NTRS)

    Vining, Cronin B.; Mccormack, Joseph A.; Zoltan, Andrew; Zoltan, Leslie D.

    1991-01-01

    Experimental and theoretical efforts directed toward increasing thermoelectric figure of merit values by a factor of 2 or 3 have been encouraging in several respects. An accurate and detailed theoretical model developed for n-type silicon-germanium (SiGe) indicates that ZT values several times higher than currently available are expected under certain conditions. These new, high ZT materials are expected to be significantly different from SiGe, but not unreasonably so. Several promising candidate materials have been identified which may meet the conditions required by theory. One such candidate, ruthenium silicide, currently under development at JPL, has been estimated to have the potential to exhibit figure of merit values 4 times higher than conventional SiGe materials. Recent results are summarized.

  6. Lightening up Ruthenium Complexes to Fight Cancer?

    PubMed

    Mari, Cristina; Gasser, Gilles

    2015-01-01

    In medicine, light is used in a medical treatment called photodynamic therapy (PDT) to treat some types of cancer and skin diseases. This technique generally allows for reduced side effects compared to traditional chemotherapy. However, PDT is not fully effective on hypoxic tumors (i.e. lacking oxygen). To overcome this important drawback, photoactivated chemotherapy (PACT) agents have been designed to obtain light-mediated cancer cell death via an oxygen-independent mechanism. Ruthenium complexes have already been and are currently deeply explored as traditional anticancer agents. However, as reported in this short review article, such compounds can also bring novel opportunities in the field of light-mediated cancer treatment. Herein, we report on our findings in the optimization of Ru(II) polypyridyl complexes as PDT and PACT agents for the potential treatment of cancer and, interestingly, also of bacterial infections.

  7. Synergetic effect of palladium-ruthenium nanostructures for ethanol electrooxidation in alkaline media

    NASA Astrophysics Data System (ADS)

    Monyoncho, Evans A.; Ntais, Spyridon; Soares, Felipo; Woo, Tom K.; Baranova, Elena A.

    2015-08-01

    Palladium-ruthenium nanoparticles supported on carbon PdxRu1-x/C (x = 1, 0.99, 0.95, 0.90, 0.80, 0.50) were prepared using a polyol method for ethanol electrooxidation in alkaline media. The resulting bimetallic catalysts were found to be primarily a mix of Pd metal, Ru oxides and Pd oxides. Their electrocatalytic activity towards ethanol oxidation reaction (EOR) in 1M KOH was studied using cyclic voltammetry and chronoamperometry techniques. Addition of 1-10 at.% Ru to Pd not only lowers the onset oxidation potential for EOR but also produces higher current densities at lower potentials compared to Pd by itself. Thus, Pd90Ru10/C and Pd99Ru1/C provide the current densities of up to six times those of Pd/C at -0.96 V and -0.67 V vs MSE, respectively. The current density at different potentials was found to be dependent on the surface composition of PdxRu1-x/C nanostructures. Pd90Ru10/C catalyst with more surface oxides was found to be active at lower potential compared to Pd99Ru1/C with less surface oxides, which is active at higher potentials. The steady-state current densities of the two best catalysts, Pd90Ru10/C and Pd99Ru1/C, showed minimal surface deactivation from EOR intermediates/products during chronoamperometry.

  8. Nuclear targets of photodynamic tridentate ruthenium complexes.

    PubMed

    Zhao, Ran; Hammitt, Richard; Thummel, Randolph P; Liu, Yao; Turro, Claudia; Snapka, Robert M

    2009-12-28

    Octahedral ruthenium complexes, capable of photodynamic singlet oxygen production at near 100% efficiency, were shown to cause light-dependent covalent crosslinking of p53 and PCNA subunits in mammalian cells and cell lysates. Azide, a singlet oxygen quencher, greatly reduced the p53 photocrosslinking, consistent with the idea that singlet oxygen is the reactive oxygen species involved in p53 photocrosslinking. A photodynamically inactive ruthenium complex, [Ru(tpy)(2)](2+) (tpy = [2,2';6',2'']-terpyridine), had no effect on p53 or PCNA photocrosslinking. Photodynamic damage to p53 has particular relevance since p53 status is an important determinant of phototoxicity and the effectiveness of photodynamic cancer therapy. The two photodynamic complexes studied, [Ru(tpy)(pydppn)](2+), where pydppn = (3-(pyrid-2'-yl)-4,5,9,16-tetraaza-dibenzo[a,c]naphthacene, and [Ru(pydppn)(2)](2+), differed in their efficiency of p53 and PCNA photocrosslinking in cells, but showed similar efficiency of photocrosslinking in cell lysates, suggesting that they differ in their ability to enter cells. Photocrosslinking of PCNA by [Ru(tpy)(pydppn)](2+) increased linearly with concentration, time of uptake, or light exposure. Both [Ru(tpy)(pydppn)](2+) and [Ru(pydppn)(2)](2+) caused photodynamic protein-DNA crosslinking in cells, but [Ru(tpy)(pydppn)](2+) was more efficient. The efficiency of photodynamic protein-DNA crosslinking by [Ru(tpy)(pydppn)](2+) in cells increased with increasing levels of photodynamic damage. Photodynamic damage by [Ru(tpy)(pydppn)](2+) caused inhibition of DNA replication in a classical biphasic response, suggesting that DNA damage signaling and cell cycle checkpoint pathways were still operative after significant damage to nuclear proteins.

  9. Antimicrobial ruthenium complex coating on the surface of titanium alloy. High efficiency anticorrosion protection of ruthenium complex.

    PubMed

    El-Gamel, Nadia E A; Fekry, Amany M

    2015-08-01

    A ruthenium complex was prepared and structurally characterized using various techniques. Antibacterial and antifungal activities of ruthenium complex were evaluated. High significant antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans was recorded. Minor cytotoxicity records were reported at the highest concentration level using MTT assay. The influence of Cu(II), Cr(III), Fe(III) and Ru(III) metal ions of salen Schiff base on the corrosion resistance of Ti-alloy in 0.5M HCl was studied. In vitro corrosion resistance was investigated using electrochemical impedance spectroscopy (EIS) measurements and confirmed by surface examination via scanning electron microscope (SEM) technique. Both impedance and phase angle maximum (θ(max)) values were at maximum in the case of the ruthenium complex with promising antibacterial and antifungal activities. The surface film created by the ruthenium complex was highly resistant against attack or deterioration by bacteria. The EIS study showed high impedance values for the ruthenium complex with increasing exposure time up to 8 days. SEM images showed uniform distribution and adsorption of Ru(III) ions on Ti-alloy surface. The ruthenium complex, as a model of organic-inorganic hybrid complex, offered new prospects with desired properties in industrial and medical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. KSC-99pp1417

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour is viewed atop the mobile launcher platform on its way to Launch Pad 39A for launch of mission STS-99. Named the Shuttle Radar Topography Mission (SRTM), STS-99 involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will chart a new course, using two antennae and a 200-foot-long section of space station-derived mast protruding from its payload bay, to produce unrivaled 3-D images of the Earth's surface. The result of the Shuttle Radar Topography Mission could be close to 1 trillion measurements of the Earth's topography. Besides contributing to the production of better maps, these measurements could lead to improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, and enhanced navigation safety. STS-99 is scheduled for launch in January 2000

  11. KSC-99pp1418

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Under breaking clouds, Space Shuttle Endeavour, atop the mobile launcher platform and crawler-transporter, crawls its way to Launch Pad 39A for mission STS-99. Named the Shuttle Radar Topography Mission (SRTM), STS-99 involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will chart a new course, using two antennae and a 200-foot-long section of space station-derived mast protruding from its payload bay, to produce unrivaled 3-D images of the Earth's surface. The result of the Shuttle Radar Topography Mission could be close to 1 trillion measurements of the Earth's topography. Besides contributing to the production of better maps, these measurements could lead to improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, and enhanced navigation safety. STS-99 is scheduled for launch in January 2000

  12. Phosphine- and hydrogen-free: highly regioselective ruthenium-catalyzed hydroaminomethylation of olefins.

    PubMed

    Gülak, Samet; Wu, Lipeng; Liu, Qiang; Franke, Robert; Jackstell, Ralf; Beller, Matthias

    2014-07-07

    A highly regioselective ruthenium-catalyzed hydroaminomethylation of olefins is reported. Using easily available trirutheniumdodecacarbonyl an efficient sequence consisting of a water-gas shift reaction, hydroformylation of olefins, with subsequent imine or enamine formation and final reduction is realized. This novel procedure is highly practical (ligand-free, one pot) and economic (low catalyst loading and inexpensive metal). Bulk industrial as well as functionalized olefins react with various amines to give the corresponding tertiary amines generally in high yields (up to 92 %), excellent regioselectivities (n/iso>99:1), and full chemoselectivity in favor of terminal olefins. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Iridium-Doped Ruthenium Oxide Catalyst for Oxygen Evolution

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Narayan, Sri R.; Billings, Keith J.

    2011-01-01

    NASA requires a durable and efficient catalyst for the electrolysis of water in a polymer-electrolyte-membrane (PEM) cell. Ruthenium oxide in a slightly reduced form is known to be a very efficient catalyst for the anodic oxidation of water to oxygen, but it degrades rapidly, reducing efficiency. To combat this tendency of ruthenium oxide to change oxidation states, it is combined with iridium, which has a tendency to stabilize ruthenium oxide at oxygen evolution potentials. The novel oxygen evolution catalyst was fabricated under flowing argon in order to allow the iridium to preferentially react with oxygen from the ruthenium oxide, and not oxygen from the environment. Nanoparticulate iridium black and anhydrous ruthenium oxide are weighed out and mixed to 5 18 atomic percent. They are then heat treated at 300 C under flowing argon (in order to create an inert environment) for a minimum of 14 hours. This temperature was chosen because it is approximately the creep temperature of ruthenium oxide, and is below the sintering temperature of both materials. In general, the temperature should always be below the sintering temperature of both materials. The iridium- doped ruthenium oxide catalyst is then fabricated into a PEM-based membrane- electrode assembly (MEA), and then mounted into test cells. The result is an electrolyzer system that can sustain electrolysis at twice the current density, and at the same efficiency as commercial catalysts in the range of 100-200 mA/sq cm. At 200 mA/sq cm, this new system operates at an efficiency of 85 percent, which is 2 percent greater than commercially available catalysts. Testing has shown that this material is as stable as commercially available oxygen evolution catalysts. This means that this new catalyst can be used to regenerate fuel cell systems in space, and as a hydrogen generator on Earth.

  14. KSC-99pp1400

    NASA Image and Video Library

    1999-12-08

    KENNEDY SPACE CENTER, FLA. -- Workers in the Vehicle Assembly Building move orbiter Endeavour's main engine No. 3 (in front) out of the way before moving the replacement engine into place. Following routine testing procedures on a separate test engine, analysis revealed delamination on the wall of the engine's main combustion chamber. When data revealed that one of Endeavour's engines had undergone similar testing procedures, managers opted to replace the suspect engine as a precaution. Space Shuttle Endeavour is targeted for launch on mission STS-99 on Jan. 13, 2000, at 1:11 p.m. EST. STS-99 is the Shuttle Radar Topography Mission

  15. KSC-99padig041

    NASA Image and Video Library

    1999-12-08

    KENNEDY SPACE CENTER, FLA. -- This close-up of Space Shuttle Endeavour's main engines shows the replacement for main engine No. 3 (lower right) ready to be installed. Following routine testing procedures on a separate test engine, analysis revealed delamination on the wall of the engine's main combustion chamber. When data revealed that one of Endeavour's engines had undergone similar testing procedures, managers opted to replace the suspect engine as a precaution. Space Shuttle Endeavour is targeted for launch at 1:11 p.m. EST Jan. 13, 2000, on mission STS-99. It will be Endeavour's 14th flight. STS-99 is the Shuttle Radar Topography Mission

  16. KSC-99pp1401

    NASA Image and Video Library

    1999-12-08

    KENNEDY SPACE CENTER, FLA. -- Workers in the Vehicle Assembly Building move orbiter Endeavour's replacement main engine No. 3 onto a work stand to prepare it for installation in the orbiter. Following routine testing procedures on a separate test engine, analysis revealed delamination on the wall of the engine's main combustion chamber. When data revealed that one of Endeavour's engines had undergone similar testing procedures, managers opted to replace the suspect engine as a precaution. Space Shuttle Endeavour is targeted for launch on mission STS-99 on Jan. 13, 2000, at 1:11 p.m. EST. STS-99 is the Shuttle Radar Topography Mission

  17. Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

    ERIC Educational Resources Information Center

    Rapp, Teresa L.; Phillips, Susan R.; Dmochowski, Ivan J.

    2016-01-01

    The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, lightdriven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes…

  18. Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

    ERIC Educational Resources Information Center

    Rapp, Teresa L.; Phillips, Susan R.; Dmochowski, Ivan J.

    2016-01-01

    The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, lightdriven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes…

  19. Studies on separation and purification of fission (99)Mo from neutron activated uranium aluminum alloy.

    PubMed

    Rao, Ankita; Kumar Sharma, Abhishek; Kumar, Pradeep; Charyulu, M M; Tomar, B S; Ramakumar, K L

    2014-07-01

    A new method has been developed for separation and purification of fission (99)Mo from neutron activated uranium-aluminum alloy. Alkali dissolution of the irradiated target (100mg) results in aluminum along with (99)Mo and a few fission products passing into solution, while most of the fission products, activation products and uranium remain undissolved. Subsequent purification steps involve precipitation of aluminum as Al(OH)3, iodine as AgI/AgIO3 and molybdenum as Mo-α-benzoin oxime. Ruthenium is separated by volatilization as RuO4 and final purification of (99)Mo was carried out using anion exchange method. The radiochemical yield of fission (99)Mo was found to be >80% and the purity of the product was in conformity with the international pharmacopoeia standards.

  20. JENDL Dosimetry File 99.

    SciTech Connect

    KEIICHI,; SHIBATA,

    2001-01-22

    Version 00 JENDL/D-99 contains information for 47 nuclides and 67 reactions in the SAND-II group structure (although it was observed by RSICC that not all of the processed files are in the SAND-II group structure) and as 0K preprocessed pointwise files.

  1. 99 Films on Drugs.

    ERIC Educational Resources Information Center

    Weber, David O., Ed.

    This catalog describes and evaluates 16-millimeter films about various aspects of drug use. Among the subjects covered by the 99 films are the composition and effects of different drugs, reasons why people use drugs, life in the drug culture, the problem of law enforcement, and various means of dealing with drug users. Each film is synopsized. Two…

  2. Ruthenium Catalysis in the Synthesis of Six-Membered Heterocycles

    NASA Astrophysics Data System (ADS)

    Zhang, Min

    Owing to the cost-effectiveness and versatility of ruthenium in catalysis, the utilization of ruthenium for developing atom and step-economic methodologies, allowing for the synthesis of six-membered heterocycles, is of particular importance in synthetic chemistry because of the important value of such compounds employed in discovering biologically and pharmacologically active compositions, the preparation of novel materials with specific functions, etc. This chapter highlights the recent 15 years' advances on ruthenium-catalyzed synthesis of six-membered heterocycles, with particular focus on the related approaches and mechanistic basis, which includes the synthesis of N-heterocycles, O-heterocycles, N,O-heterocycles, and other type of heteroatom-heterocycles.

  3. Radioactive equilibrium: 99Mo/99mTc decay characteristics.

    PubMed

    Chechev, Valery P; Bé, Marie-Martine

    2014-05-01

    Within the Decay Data Evaluation Project, as an example of a radioactive equilibrium with isomer, the (99)Mo/(99m)Tc equilibrium mixture decay characteristics are examined. The results of a new decay data evaluation are presented for (99)Mo/(99m)Tc decay to nuclear levels in (99)Tc. These evaluated data have been obtained using information published up to 2013. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Adapting Ruthenium Sensitizers to Cobalt Electrolyte Systems.

    PubMed

    Amit Kumar, Sangeeta; Urbani, Maxence; Medel, María; Ince, Mine; González-Rodríguez, David; Chandiran, Aravind Kumar; Bhaskarwar, Ashok N; Torres, Tomás; Nazeeruddin, Md K; Grätzel, Michael

    2014-02-06

    In this work, we report the use of bulky substitutions in a new heteroleptic ruthenium(II) bipyridine complex, Ru(NCS)2LL', coded TT-230 to obtain high open-circuit potential in a dye-sensitized solar cell (where L is a bipyridine ligand appended with two cyclopenta(2,1-b;3,4-bA)dithiophene moieties, and L' = 4,4,'-dicarboxylic acid 2,2'-bipyridine). The electrolytes based on cobalt complexes have shown significant advantages in terms of attainable open-circuit potential compared to the standard iodide/tri-iodide redox mediators. These merits of the cobalt complexes were previously realized with a porphyrin sensitizer, achieving a VOC greater than 1 V in DSC. However, with conventional Ru(II)-polypyridyl complexes such as the C101 dye, similar increase in the VOC could not be attained due to the enhanced recombination. In this work, we have shown that the use of bulky substituents can prevent the back reaction of photogenerated electron and subsequently increase the open-circuit potential of the device. The recombination processes were investigated by transient photovoltage decay measurements.

  5. Neutron Scattering from Magnetically Frustrated Ruthenium Pyrochlores

    NASA Astrophysics Data System (ADS)

    Broholm, Collin

    2008-03-01

    Spin-1 ruthenium pyrochlores feature strong exchange interactions and deeply suppressed N'eel ordering. In addition a doping induced metallic phase has been demonstrated. I discuss neutron scattering experiments that explore the strongly frustrated quantum magnetism of Y2Ru2O7 [1] and Pr2-xBixRu2O7 [2]. In Y2Ru2O7 (θCW= --1100 K, TN=77 K) much of the magnetic spectral weight is concentrated in a 20 meV spectral peak above an 11 meV low temperature gap in the excitation spectrum. In Pr2-xBixRu2O7 magnetic order which occurs for T

  6. KSC-99pp1247

    NASA Image and Video Library

    1999-10-22

    KSC volunteers with Days of Caring '99 share tasks while getting ready to paint at Baxley Manor, an apartment building for senior citizens on Merritt Island. Coordinated by the KSC Community Relations Council, Days of Caring provides an opportunity for employees to volunteer their services in projects such as painting, planting flowers, reading to school children, and more. Organizations accepting volunteers include The Embers, Yellow Umbrella, Serene Harbor, Domestic Violence Program, the YMCA of Brevard County, and others

  7. KSC-99pp1245

    NASA Image and Video Library

    1999-10-22

    A volunteer for Days of Caring '99 prepares a light fixture before painting the walls in the hallway at Baxley Manor, an apartment building for senior citizens on Merritt Island. Coordinated by the KSC Community Relations Council, Days of Caring provides an opportunity for employees to volunteer their services in projects such as painting, planting flowers, reading to school children, and more. Organizations accepting volunteers include The Embers, Yellow Umbrella, Serene Harbor, Domestic Violence Program, the YMCA of Brevard County, and others

  8. KSC-99pp1244

    NASA Image and Video Library

    1999-10-22

    KSC volunteers for Days of Caring '99 unfold protective materials before getting ready to paint at Baxley Manor, an apartment building for senior citizens on Merritt Island. Coordinated by the KSC Community Relations Council, Days of Caring provides an opportunity for employees to volunteer their services in projects such as painting, planting flowers, reading to school children, and more. Organizations accepting volunteers include The Embers, Yellow Umbrella, Serene Harbor, Domestic Violence Program, the YMCA of Brevard County, and others

  9. KSC-99pp1246

    NASA Image and Video Library

    1999-10-22

    Volunteers for Days of Caring '99 set up the paint trays for painting at Baxley Manor, an apartment building for senior citizens on Merritt Island. Coordinated by the KSC Community Relations Council, Days of Caring provides an opportunity for employees to volunteer their services in projects such as painting, planting flowers, reading to school children, and more. Organizations accepting volunteers include The Embers, Yellow Umbrella, Serene Harbor, Domestic Violence Program, the YMCA of Brevard County, and others

  10. KSC-99pp1406

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour, on its mobile launcher platform, is transferred to Launch Pad 39A for mission STS-99. Named the Shuttle Radar Topography Mission (SRTM), it involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. The SRTM consists of a specially modified radar system that will gather data for the most accurate and complete topographic map of the Earth's surface that has ever been assembled

  11. KSC-99pp1419

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Under partly cloudy skies and the Atlantic Ocean as a backdrop, Space Shuttle Endeavour, atop the mobile launcher platform, arrives at Launch Pad 39A for mission STS-99. The white cubicle at left is the environmental chamber, the White Room, that provides entry into the orbiter for the astronauts. It is at the outer end of the Orbiter Access Arm on the Fixed Service Structure. STS-99, named the Shuttle Radar Topography Mission (SRTM), involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will chart a new course, using two antennae and a 200-foot-long section of space station-derived mast protruding from its payload bay, to produce unrivaled 3-D images of the Earth's surface. The result of the Shuttle Radar Topography Mission could be close to 1 trillion measurements of the Earth's topography. Besides contributing to the production of better maps, these measurements could lead to improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, and enhanced navigation safety. STS-99 is scheduled for launch in January 2000

  12. Method of producing molybdenum-99

    SciTech Connect

    Pitcher, Eric John

    2013-05-28

    Method of producing molybdenum-99, comprising accelerating ions by means of an accelerator; directing the ions onto a metal target so as to generate neutrons having an energy of greater than 10 MeV; directing the neutrons through a converter material comprising techentium-99 to produce a mixture comprising molybdenum-99; and, chemically extracting the molybdenum-99 from the mixture.

  13. Nickel/ruthenium catalyst and method for aqueous phase reactions

    DOEpatents

    Elliott, D.C.; Sealock, J.L.

    1998-09-29

    A method of hydrogenation is described using a catalyst in the form of a plurality of porous particles wherein each particle is a support having nickel metal catalytic phase or reduced nickel deposited thereon in a first dispersed phase and an additional ruthenium metal deposited onto the support in a second dispersed phase. The additional ruthenium metal is effective in retarding or reducing agglomeration or sintering of the nickel metal catalytic phase thereby increasing the life time of the catalyst during hydrogenation reactions. 2 figs.

  14. Determination of oxygen diffusion kinetics during thin film ruthenium oxidation

    SciTech Connect

    Coloma Ribera, R. Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F.

    2015-08-07

    In situ X-ray reflectivity was used to reveal oxygen diffusion kinetics for thermal oxidation of polycrystalline ruthenium thin films and accurate determination of activation energies for this process. Diffusion rates in nanometer thin RuO{sub 2} films were found to show Arrhenius behaviour. However, a gradual decrease in diffusion rates was observed with oxide growth, with the activation energy increasing from about 2.1 to 2.4 eV. Further exploration of the Arrhenius pre-exponential factor for diffusion process revealed that oxidation of polycrystalline ruthenium joins the class of materials that obey the Meyer-Neldel rule.

  15. KSC-99pp1407

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Framed by branches of oak leaves in this photo, Space Shuttle Endeavour, on its mobile launcher platform, is transferred to Launch Pad 39A for mission STS-99. The van behind it is barely noticeable next to the gigantic stature of the moving vehicle. Named the Shuttle Radar Topography Mission (SRTM), it involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. The SRTM consists of a specially modified radar system that will gather data for the most accurate and complete topographic map of the Earth's surface that has ever been assembled

  16. KSC-99pp1243

    NASA Image and Video Library

    1999-10-22

    KSC volunteers at Miracle City Mall, Titusville, help unload containers for Meals on Wheels delivery as part of their '99 Days of Caring participation. The volunteers will also help deliver the meals. Coordinated by the KSC Community Relations Council, Days of Caring provides an opportunity for employees to volunteer their services in projects such as painting, planting flowers, reading to school children, and more. Organizations accepting volunteers include The Embers, Yellow Umbrella, Serene Harbor, Domestic Violence Program, the YMCA of Brevard County, and others

  17. KSC-99pp0331

    NASA Image and Video Library

    1999-03-22

    The Shuttle Radar Topography Mission (SRTM) sits uncovered inside the Multi-Payload Processing Facility. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  18. KSC-99pp1405

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- The doors of the Vehicle Assembly Building (VAB) are open for the transfer of Space Shuttle Endeavour, on its mobile launcher platform, to Launch Pad 39A for mission STS-99. Named the Shuttle Radar Topography Mission (SRTM), it involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. The SRTM consists of a specially modified radar system that will gather data for the most accurate and complete topographic map of the Earth's surface that has ever been assembled

  19. KSC-99pp1408

    NASA Image and Video Library

    1999-12-13

    KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour is viewed between two tree trunks in this photo during the Shuttle's rollout to Launch Pad 39A for launch of mission STS-99. Named the Shuttle Radar Topography Mission (SRTM), it involves an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. The SRTM consists of a specially modified radar system that will gather data for the most accurate and complete topographic map of the Earth's surface that has ever been assembled

  20. Technetium-99m generator system

    DOEpatents

    Mirzadeh, Saed; Knapp, Jr., Furn F.; Collins, Emory D.

    1998-01-01

    A .sup.99 Mo/.sup.99m Tc generator system includes a sorbent column loaded with a composition containing .sup.99 Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating .sup.99m Tc eluted from the sorbent column. A method of preparing a concentrated solution of .sup.99m Tc includes the general steps of: a. providing a sorbent column loaded with a composition containing .sup.99 Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; b. eluting the sorbent column with a salt solution to elute .sup.99m Tc from the sorbent and to trap and concentrate the eluted .sup.99m Tc on the ion-exchange column; and c. eluting the concentrated .sup.99m Tc from the ion-exchange column with a solution comprising a reductive complexing agent.

  1. Technetium-99m generator system

    DOEpatents

    Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

    1998-06-30

    A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

  2. Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation

    EPA Science Inventory

    Arsenate adsorption on amorphous (RuO2•1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

  3. Molecular Models of Ruthenium(II) Organometallic Complexes

    ERIC Educational Resources Information Center

    Coleman, William F.

    2007-01-01

    This article presents the featured molecules for the month of March, which appear in the paper by Ozerov, Fafard, and Hoffman, and which are related to the study of the reactions of a number of "piano stool" complexes of ruthenium(II). The synthesis of compound 2a offers students an alternative to the preparation of ferrocene if they are only…

  4. PRECIPITATION OF ZIRCONIUM, NIOBIUM, AND RUTHENIUM FROM AQUEOUS SOLUTIONS

    DOEpatents

    Wilson, A.S.

    1958-08-12

    An improvement on the"head end process" for decontaminating dissolver solutions of their Zr, Ni. and Ru values. The process consists in adding a water soluble symmetrical dialkyl ketone. e.g. acetone, before the formation of the manganese dioxide precipitate. The effect is that upon digestion, the ruthenium oxide does not volatilize, but is carried on the manganese dioxide precipitate.

  5. Arsenate Adsorption On Ruthenium Oxides: A Spectroscopic And Kinetic Investigation

    EPA Science Inventory

    Arsenate adsorption on amorphous (RuO2•1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...

  6. Molecular dinitrogen complexes of ruthenium(II) porphyrins

    SciTech Connect

    Camenzind, M.J.; James, B.R.; Dolphin, D.; Sparapany, J.W.; Ibers, J.A.

    1988-08-24

    The existence of both mono- and bis(nitrogen) complexes of ruthenium have been previously established. Details on a series of complexes are presented herein, and results of an x-ray crystallographic study of Ru(TMP) (THF) (N/sub 2/) are reported. 30 references, 4 tables.

  7. Parameters governing ruthenium sawhorse-based decarboxylation of oleic acid

    USDA-ARS?s Scientific Manuscript database

    Ruthenium-catalyzed decarboxylation of 9-cisoctadecenoic is a path to produce biobased olefins. Here, a mechanistic study of this reaction was undertaken utilizing a closed reaction system and a pressure reactor. The proposed mechanism of an isomerization followed by a decarboxylation reaction was c...

  8. Molecular Models of Ruthenium(II) Organometallic Complexes

    ERIC Educational Resources Information Center

    Coleman, William F.

    2007-01-01

    This article presents the featured molecules for the month of March, which appear in the paper by Ozerov, Fafard, and Hoffman, and which are related to the study of the reactions of a number of "piano stool" complexes of ruthenium(II). The synthesis of compound 2a offers students an alternative to the preparation of ferrocene if they are only…

  9. A new approach to synthesize supported ruthenium phosphides for hydrodesulfurization

    SciTech Connect

    Wang, Qingfang; Wang, Zhiqiang; Yin, Xiaoqian; Zhou, Linxi; Zhang, Minghui

    2016-02-15

    Highlights: • We bring out a new method to synthesize noble metal phosphides at low temperature. • Both RuP and Ru{sub 2}P were synthesized using triphenylphosphine as phosphorus sources. • Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. • RuP/SiO{sub 2} prepared by new method had better HDS activity to that by TPR method. - Abstract: Supported noble metal ruthenium phosphides were synthesized by one-step H{sub 2}-thermal treatment method using triphenylphosphine (TPP) as phosphorus sources at low temperatures. Two phosphides RuP and Ru{sub 2}P can be prepared by this method via varying the molar ratio of metal salt and TPP. The as-prepared phosphides were characterized by X-ray powder diffraction (XRD), low-temperature N{sub 2} adsorption, CO chemisorption and transmission electronic microscopy (TEM). The supported ruthenium phosphides prepared by new method and conventional method together with contradistinctive metallic ruthenium were evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The catalytic results showed that metal-rich Ru{sub 2}P was the better active phase for HDS than RuP and metal Ru. Besides this, ruthenium phosphide catalyst prepared by new method exhibited superior HDS activity to that prepared by conventional method.

  10. Improvement of ruthenium based decarboxylation of carboxylic acids

    USDA-ARS?s Scientific Manuscript database

    The removal of oxygen atoms from biobased carboxylic acids is an attractive route to provide the drop in replacement feedstocks that industry needs to continue to provide high performance products. Through the use of ruthenium catalysis, an efficient method where this process can be accomplished on ...

  11. Ruthenium-catalyzed C–H activation of thioxanthones

    PubMed Central

    Wagner, Danny

    2015-01-01

    Summary Thioxanthones – being readily available in one step from thiosalicylic acid and arenes – were used in ruthenium-catalyzed C–H-activation reaction to produce 1-mono- or 1,8-disubstituted thioxanthones in good to excellent yields. Scope and limitation of this reaction are presented. PMID:25977717

  12. Ruthenium-catalyzed tertiary amine formation from nitroarenes and alcohols.

    PubMed

    Feng, Chao; Liu, Yong; Peng, Shengming; Shuai, Qi; Deng, Guojun; Li, Chao-Jun

    2010-11-05

    A highly selective ruthenium-catalyzed C-N bond formation was developed by using the hydrogen-borrowing strategy. Various tertiary amines were obtained efficiently from nitroarenes and primary alcohols. The reaction tolerates a wide range of functionalities. A tentative mechanism was proposed for this direct amination reaction of alcohols with nitroarenes.

  13. High-Performance Ruthenium Sensitizers Containing Imidazolium Counterions for Efficient Dye Sensitization in Water.

    PubMed

    Li, Xiaoyu; Li, Shiqing; Gao, Ge; Wu, Di; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2017-07-21

    A new type of water-soluble ruthenium sensitizers incorporating imidazolium counterions, denoted [DMPI]2 -Ru and [DMHI]2 -Ru, has been developed, which can be efficiently adsorbed onto TiO2 photoanodes in aqueous solution. Owing to the good thermal stability of imidazolium, [DMPI]2 -Ru adsorbed on TiO2 has a higher decomposition temperature than N719 dye [di(tetrabutylammonium) cis-di(thiocyanato)bis(2,2'-bipyridine-4,4'-dicarboxylato)ruthenium(II)]. When using organic solvent-based I(-) /I3(-) electrolytes, solars cell based on [DMPI]2 -Ru-sensitized TiO2 in water show high power conversion efficiencies (PCE) of up to 10.2 %, which is higher than that of N719 (9.9 %) under the common conditions for dye sensitization in organic solvent. [DMHI]2 -Ru, with poorer water solubility than [DMPI]2 -Ru, gives a smaller dye-adsorption amount on TiO2 and thus a lower PCE of 9.4 %. From the viewpoint of safety and environmental impact, the fabrication of dye-sensitized solar cells (DSSCs) by using water as solvent is undoubtedly a preferable strategy. Although the [DMPI]2 -Ru-based device fabricated by using water as the solvent for both the dye-sensitization process and the electrolyte gives a relatively low efficiency, it provides a promising approach for the practical application of DSSCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Study on volatilization mechanism of ruthenium tetroxide from nitrosyl ruthenium nitrate by using mass spectrometer

    NASA Astrophysics Data System (ADS)

    Kato, Tetsuya; Usami, Tsuyoshi; Tsukada, Takeshi; Shibata, Yuki; Kodama, Takashi

    2016-10-01

    In a cooling malfunction accident of a high-level liquid waste (HLLW) tank, behavior of ruthenium (Ru) attracts much attention, since Ru could be oxidized to a volatile chemical form in the boiling and drying of HLLW, and part of radioactive Ru can potentially be released to the environment. In this study, nitrosyl Ru nitrate (Ru(NO)(NO3)3) dissolved in nitric acid (HNO3), which is commonly contained in a simulated HLLW, was dried and heated up to 723 K, and the evolved gas was introduced into a mass spectrometer. The well-known volatile species, ruthenium tetroxide (RuO4) was detected in a temperature range between 390 K and 500 K with the peak top around 440 K. Various gases such as HNO3, nitrogen dioxide (NO2), nitrogen monoxide (NO) also evolved due to evaporation of the nitric acid and decomposition of the nitrate ions. The ion current of RuO4 seems to increase with the increasing decomposition of nitrate, while the evaporation of HNO3 decreases. More volatilization of RuO4 was observed from the HNO3 solution containing not only Ru(NO)(NO3)3 but also cerium nitrate (Ce(NO3)3·6H2O) which was added for extra supply of nitrate ion, compared with that from the HNO3 solution containing only Ru(NO)(NO3)3. These experimental results suggest that Ru could be oxidized to form RuO4 by the nitrate ion as well as HNO3.

  15. Ruthenium red-induced bundling of bacterial cell division protein, FtsZ.

    PubMed

    Santra, Manas Kumar; Beuria, Tushar K; Banerjee, Abhijit; Panda, Dulal

    2004-06-18

    The assembly of FtsZ plays a major role in bacterial cell division, and it is thought that the assembly dynamics of FtsZ is a finely regulated process. Here, we show that ruthenium red is able to modulate FtsZ assembly in vitro. In contrast to the inhibitory effects of ruthenium red on microtubule polymerization, we found that a substoichiometric concentration of ruthenium red strongly increased the light-scattering signal of FtsZ assembly. Further, sedimentable polymer mass was increased by 1.5- and 2-fold in the presence of 2 and 10 microm ruthenium red, respectively. In addition, ruthenium red strongly reduced the GTPase activity and prevented dilution-induced disassembly of FtsZ polymers. Electron microscopic analysis showed that 4-10 microm of ruthenium red produced thick bundles of FtsZ polymers. The significant increase in the light-scattering signal and pelletable polymer mass in the presence of ruthenium red seemed to be due to the bundling of FtsZ protofilaments into larger polymers rather than the actual increase in the level of polymeric FtsZ. Furthermore, ruthenium red was found to copolymerize with FtsZ, and the copolymerization of substoichiometric amounts of ruthenium red with FtsZ polymers promoted cooperative assembly of FtsZ that produced large bundles. Calcium inhibited the binding of ruthenium red to FtsZ. However, a concentration of calcium 1000-fold higher than that of ruthenium red was required to produce similar effects on FtsZ assembly. Ruthenium red strongly modulated FtsZ polymerization, suggesting the presence of an important regulatory site on FtsZ and suggesting that a natural ligand, which mimics the action of ruthenium red, may regulate the assembly of FtsZ in bacteria.

  16. KSC-99pp0502

    NASA Image and Video Library

    1999-05-07

    The Shuttle Radar Topography Mission (SRTM) is moved into the Space Station Processing Facility to prepare it for launch targeted for September 1999. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  17. KSC-99pp0329

    NASA Image and Video Library

    1999-03-24

    Inside the Multi-Payload Processing Facility, the Shuttle Radar Topography Mission (SRTM) is revealed after the lid of its container was removed. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  18. KSC-99pp0311

    NASA Image and Video Library

    1999-03-23

    In the Multi-Payload Processing Facility, Mary Reaves and Richard Rainen, with the Jet Propulsion Laboratory, work on the carrier and horizontal antenna mast for the STS-99 Shuttle Radar Topography Mission (SRTM) while Larry Broms watches. The SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during an 11-day mission in September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  19. KSC-99pp0503

    NASA Image and Video Library

    1999-05-07

    Inside the Space Station Processing Facility, the Shuttle Radar Topography Mission (SRTM) is maneuvered into place to prepare it for launch targeted for September 1999. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  20. KSC-99pp0330

    NASA Image and Video Library

    1999-03-24

    The Shuttle Radar Topography Mission (SRTM) sits inside the Multi-Payload Processing Facility after the SRTM's cover was removed. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  1. KSC-99pp0327

    NASA Image and Video Library

    1999-03-24

    Inside the Multi-Payload Processing Facility, the lid covering the Shuttle Radar Topography Mission (SRTM) is lifted. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  2. KSC-99pp0326

    NASA Image and Video Library

    1999-03-24

    The vehicle carrying the Shuttle Radar Topography Mission (SRTM) arrives at the Multi-Payload Processing Facility. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  3. KSC-99pp0328

    NASA Image and Video Library

    1999-03-24

    Inside the Multi-Payload Processing Facility, the lid covering the Shuttle Radar Topography Mission (SRTM) is lifted from the crate. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  4. KSC-99pp0312

    NASA Image and Video Library

    1999-03-23

    In the Multi-Payload Processing Facility, Beverly St. Ange, with the Jet Propulsion Laboratory, wires a biopod, a component of the STS-99 Shuttle Radar Topography Mission (SRTM). The SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during an 11-day mission in September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  5. KSC-99pp0313

    NASA Image and Video Library

    1999-03-23

    In the Multi-Payload Processing Facility, Mary Reaves (left) and Richard Rainen, with the Jet Propulsion Laboratory, check out the carrier and horizontal antenna mast for the STS-99 Shuttle Radar Topography Mission (SRTM). The SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during an 11-day mission in September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  6. KSC-99pp0505

    NASA Image and Video Library

    1999-05-07

    In the Space Station Processing Facility (SSPF), workers (lower right) disconnect the transport vehicle from the Shuttle Radar Topography Mission (SRTM) after moving it into the building for pre-launch preparations. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission targeted for launch in September 1999. This radar system will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth

  7. Technetium-99 in generator systems.

    PubMed

    Moore, P W

    1984-04-01

    Technetium-99m solutions always contain Tc-99. The amount varies considerably, depending on production methods and conditions, generator performance, and the time between production or separation and use. There is increasing evidence that labeling and imaging with some radiopharmaceutical kits is adversely affected when the Tc-99 exceeds certain amounts. The sensitivity of particular kits to Tc-99 depends on the ligand, the amount of usable Sn2+, and the ratio of Tc to ligand. Although Tc-99 formed during production is removed in the final steps of generator manufacture, some may appear in early extractions in the solvent extraction process. If elution or extraction efficiencies are high, any Tc-99 is reduced within about two elutions to an insignificant level that is maintained in subsequent elutions. If efficiencies are below about 40%, however, the ratio of Tc-99 to Tc-99m increases with each elution.

  8. First acyclic diene metathesis polymerization under biphasic conditions using a dicationic ruthenium alkylidene: access to high-molecular-weight polymers with very low ruthenium contamination.

    PubMed

    Zhao, Jing; Wang, Dongren; Autenrieth, Benjamin; Buchmeiser, Michael R

    2015-01-01

    The acyclic diene metathesis (ADMET) polymerization of 6-hydroxy-1,10-undecadiene (M1) and 6-acetoxy-1,10-undecadiene (M2) by the action of two different catalysts, i.e., the second-generation Grubbs-Hoveyda system ([RuCl2(IMesH2)(CH-2-(2-PrO-C6H4)]) (1) and the dicationic ruthenium alkylidene [Ru(DMF)3(IMesH2)(CH-2-(2-PrO-C6H4)] (2, IMesH2 = 1,3-dimesitylimidazolin-2-ylidene) is reported. Biphasic conditions using 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([BDMIM(+)BF4(-)]) and 1,2,4-trichlorobenzene (TCB) are applied. Under the chosen conditions (T = 75 °C, 20 mbar), the use of catalyst 1 results only in the formation of low-molecular-weight polymers (Mn ≤ 10,000 g mol(-1)), while catalyst 2 allows for the high yield synthesis of high-molecular-weight polymers (Mn ≤ 40,000 g mol(-1), yields ≤ 99%). Irrespective of the catalyst used, all polymers display a high trans-content (>95%). Notably, Ru-contamination of the target polymers without any additional purification is as low as 1.2 ppm with catalyst 2. Together with the high yields and high molecular weights, the low Ru-contaminations clearly illustrate the advantages of the biphasic setup.

  9. Spectroscopic investigation on the interaction of ruthenium complexes with tumor specific lectin, jacalin.

    PubMed

    Ayaz Ahmed, Khan Behlol; Reshma, Elamvazhuthi; Mariappan, Mariappan; Anbazhagan, Veerappan

    2015-02-25

    Several ruthenium complexes are regarded as anticancer agents and considered as an alternative to the widely used platinum complexes. Owing to the preferential interaction of jacalin with tumor-associated T-antigen, we report the interaction of jacalin with four ruthenium complex namely, tris(1,10-phenanthroline)ruthenium(II)chloride, bis(1,10-phenanthroline)(N-[1,10]phenanthrolin-5-yl-pyrenylmethanimine)ruthenium(II)chloride, bis(1,10-phenanthroline)(dipyrido[3,2-a:2',3'-c]-phenazine)ruthenium(II)chloride, bis(1,10-phenanthroline)(11-(9-acridinyl)dipyrido[3,2-a:2',3'-c]phenazine)ruthenium(II) chloride. Fluorescence spectroscopic analysis revealed that the ruthenium complexes strongly quenched the intrinsic fluorescence of jacalin through a static quenching procedure, and a non-radiative energy transfer occurred within the molecules. Association constants obtained for the interaction of different ruthenium complexes with jacalin are in the order of 10(5) M(-1), which is in the same range as those obtained for the interaction of lectin with carbohydrate and hydrophobic ligand. Each subunit of the tetrameric jacalin binds one ruthenium complex, and the stoichiometry is found to be unaffected by the presence of the specific sugar, galactose. In addition, agglutination activity of jacalin is largely unaffected by the presence of the ruthenium complexes, indicating that the binding sites for the carbohydrate and the ruthenium complexes are different. These results suggest that the development of lectin-ruthenium complex conjugate would be feasible to target malignant cells in chemo-therapeutics. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Spectroscopic investigation on the interaction of ruthenium complexes with tumor specific lectin, jacalin

    NASA Astrophysics Data System (ADS)

    Ayaz Ahmed, Khan Behlol; Reshma, Elamvazhuthi; Mariappan, Mariappan; Anbazhagan, Veerappan

    2015-02-01

    Several ruthenium complexes are regarded as anticancer agents and considered as an alternative to the widely used platinum complexes. Owing to the preferential interaction of jacalin with tumor-associated T-antigen, we report the interaction of jacalin with four ruthenium complex namely, tris(1,10-phenanthroline)ruthenium(II)chloride, bis(1,10-phenanthroline)(N-[1,10]phenanthrolin-5-yl-pyrenylmethanimine)ruthenium(II)chloride, bis(1,10-phenanthroline)(dipyrido[3,2-a:2‧,3‧-c]-phenazine)ruthenium(II)chloride, bis(1,10-phenanthroline)(11-(9-acridinyl)dipyrido[3,2-a:2‧,3‧-c]phenazine)ruthenium(II) chloride. Fluorescence spectroscopic analysis revealed that the ruthenium complexes strongly quenched the intrinsic fluorescence of jacalin through a static quenching procedure, and a non-radiative energy transfer occurred within the molecules. Association constants obtained for the interaction of different ruthenium complexes with jacalin are in the order of 105 M-1, which is in the same range as those obtained for the interaction of lectin with carbohydrate and hydrophobic ligand. Each subunit of the tetrameric jacalin binds one ruthenium complex, and the stoichiometry is found to be unaffected by the presence of the specific sugar, galactose. In addition, agglutination activity of jacalin is largely unaffected by the presence of the ruthenium complexes, indicating that the binding sites for the carbohydrate and the ruthenium complexes are different. These results suggest that the development of lectin-ruthenium complex conjugate would be feasible to target malignant cells in chemo-therapeutics.

  11. Synthesis of PVP-stabilized ruthenium colloids with low boiling point alcohols.

    PubMed

    Zhang, Yuqing; Yu, Jiulong; Niu, Haijun; Liu, Hanfan

    2007-09-15

    A route to the preparation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized ruthenium colloids by refluxing ruthenium(III) chloride in low boiling point alcohols was developed. Deep purple colloids with shuttle-like ruthenium particles were also synthesized. XPS measurement verified the nanoparticles were in the metallic state. The morphology of metal nanoparticles was characterized by UV-visible absorption spectrophotometry, TEM and XRD.

  12. KSC-99pp1040

    NASA Image and Video Library

    1999-08-12

    A shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A) is transferred onto a transporter from the C-5 air cargo plane that brought it to KSC. The hardware will be taken to the Payload Hazardous Servicing Facility for final testing and integration of payload elements. Mission STS-103 is a "call-up" mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review

  13. KSC-99pp1037

    NASA Image and Video Library

    1999-08-12

    A C-5 air cargo plane lands at Kennedy Space Center carrying the payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will be taken to the Payload Hazardous Servicing Facility for final testing and integration of payload elements. Mission STS-103 is a "call-up" mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review

  14. KSC-99pp1039

    NASA Image and Video Library

    1999-08-12

    A shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A) is ready for transfer onto a transporter from the C-5 air cargo plane that brought it to KSC. The hardware will be taken to the Payload Hazardous Servicing Facility for final testing and integration of payload elements. Mission STS-103 is a "call-up" mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review

  15. STS-99 Crew Insignia

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The STS-99 crew members designed the flight insignia for the Shuttle Radar Topography Mission (SRTM), the most ambitious Earth mapping mission to date. Two radar anternas, one located in the Shuttle bay and the other located on the end of a 60-meter deployable mast, was used during the mission to map Earth's features. The goal was to provide a 3-dimensional topographic map of the world's surface up to the Arctic and Antarctic Circles. In the patch, the clear portion of Earth illustrates the radar beams penetrating its cloudy atmosphere and the unique understanding of the home planet that is provided by space travel. The grid on Earth reflects the mapping character of the SRTM mission. The patch depicts the Space Shuttle Endeavour orbiting Earth in a star spangled universe. The rainbow along Earth's horizon resembles an orbital sunrise. The crew deems the bright colors of the rainbow as symbolic of the bright future ahead because of human beings' venturing into space. The crew of six launched aboard the Space Shuttle Endeavor on February 11, 2000 and completed 222 hours of around the clock radar mapping gathering enough information to fill more than 20,000 CDs.

  16. KSC-99pp0523

    NASA Image and Video Library

    1999-05-13

    Inside the Space Station Processing Facility, workers at each end of a workstand watch as the Shuttle Radar Topography Mission (SRTM) begins its descent onto it. The SRTM, which is the primary payload on mission STS-99, consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  17. KSC-99pp0521

    NASA Image and Video Library

    1999-05-13

    After being lifted off the transporter (lower right) in the Space Station Processing Facility, the Shuttle Radar Topography Mission (SRTM) moves across the floor toward a workstand. The SRTM, which is the primary payload on mission STS-99, consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  18. KSC-99pp0524

    NASA Image and Video Library

    1999-05-13

    The move of the Shuttle Radar Topography Mission (SRTM) is nearly complete as it is lowered onto the workstand in the Space Station Processing Facility. The SRTM, which is the primary payload on mission STS-99, consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  19. KSC-99pp0520

    NASA Image and Video Library

    1999-05-13

    Workers inside the Space Station Processing Facility keep watch as an overhead crane begins lifting the Shuttle Radar Topography Mission (SRTM) from the transporter below. The SRTM is being moved to a workstand. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  20. KSC-99pp0522

    NASA Image and Video Library

    1999-05-13

    Inside the Space Station Processing Facility, the Shuttle Radar Topography Mission (SRTM) is maneuvered by an overhead crane toward a workstand below. The SRTM, which is the primary payload on mission STS-99, consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  1. KSC-99pp0519

    NASA Image and Video Library

    1999-05-13

    Inside the Space Station Processing Facility, workers watch as an overhead crane is lowered for lifting the Shuttle Radar Topography Mission (SRTM) from the transporter it is resting on. The SRTM is being moved to a workstand. The primary payload on mission STS-99, the SRTM consists of a specially modified radar system that will fly onboard the Space Shuttle during the 11-day mission scheduled for launch in September 1999. The objective of this radar system is to obtain the most complete high-resolution digital topographic database of the Earth. It will gather data that will result in the most accurate and complete topographic map of the Earth's surface that has ever been assembled. SRTM is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. SRTM will be making use of a technique called radar interferometry, wherein two radar images are taken from slightly different locations. Differences between these images allow for the calculation of surface elevation, or change. To get two radar images taken from different locations, the SRTM hardware will consist of one radar antenna in the shuttle payload bay and a second radar antenna attached to the end of a mast extended 60 meters (195 feet) out from the shuttle

  2. KSC-99pp1038

    NASA Image and Video Library

    1999-08-12

    A C-5 air cargo plane opens to reveal a shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A). The hardware will be taken to the Payload Hazardous Servicing Facility for final testing and integration of payload elements. Mission STS-103 is a "call-up" mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review

  3. KSC-99pp1041

    NASA Image and Video Library

    1999-08-12

    A shipping container with payload flight hardware for the Third Hubble Space Telescope Servicing Mission (SM-3A) sits on a flatbed trailer for transfer to the Payload Hazardous Servicing Facility where it will undergo final testing and integration of payload elements. Mission STS-103 is a "call-up" mission which is being planned due to the need to replace portions of the Hubble's pointing system, the gyros, which have begun to fail. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS-103 crew will not only replace gyroscopes, it will also replace a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Launch of STS-93 is currently targeted for Oct. 14 but under review, pending the launch date of a prior mission, STS-99, also under review

  4. Surface and sub-surface thermal oxidation of thin ruthenium films

    SciTech Connect

    Coloma Ribera, R.; Kruijs, R. W. E. van de; Yakshin, A. E.; Bijkerk, F.; Kokke, S.; Zoethout, E.

    2014-09-29

    A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low density and high density oxides. Nano-columns grow at the surface of the low density oxide layer, with the growth rate being limited by diffusion of ruthenium through the formed oxide film. Simultaneously, with the growth of the columns, sub-surface high density oxide continues to grow limited by diffusion of oxygen or ruthenium through the oxide film.

  5. CuAAC click reactions for the design of multifunctional luminescent ruthenium complexes.

    PubMed

    Zabarska, Natalia; Stumper, Anne; Rau, Sven

    2016-02-14

    CuAAC (Cu(i) catalyzed azide-alkyne cycloaddition) click chemistry has emerged as a versatile tool in the development of photoactive ruthenium complexes with multilateral potential applicability. In this contribution we discuss possible synthetic approaches towards CuAAC reactions with ruthenium(ii) polypyridine complexes and their differences with respect to possible applications. We focus on two main application possibilities of the click-coupled ruthenium assemblies. New results within the development of ruthenium based photosensitizers for the field of renewable energy supply, i.e. DSSCs (dye-sensitized solar cells) and artificial photocatalysis for the production of hydrogen, or for anticancer photodynamic therapeutic applications are reviewed.

  6. Electrochemical capacitor performance of hydrous ruthenium oxide/mesoporous carbon composite electrodes

    NASA Astrophysics Data System (ADS)

    Jang, Jong H.; Han, Sangjin; Hyeon, Taeghwan; Oh, Seung M.

    Ruthenium/carbon composite materials are prepared by impregnating ruthenium(III) acetylacetonate into a mesoporous carbon (average pore diameter=12 mn, pore volume=3.6 cm 3 g -1) and then heat treatment at 320 °C for 2 h under an argon atmosphere. The metallic ruthenium nanoparticles are converted to pseudo-capacitive hydrous ruthenium oxide by electrochemical oxidation at 0.75 V (versus SCE) for 2 h in 2.0 M H 2SO 4. The specific capacitance of the composite electrodes, which is the sum of the double-layer capacitance of mesoporous carbon and the pseudo-capacitance of hydrous ruthenium oxide, reaches 243 F g -1 with heavy loading. As the loading is increased, however, the degree of ruthenium utilization for a pseudo-capacitor becomes poorer, presumably due to a limited conversion to the hydrous oxide form. The rate capability of composite electrodes also decreases with increase in ruthenium loading, due to an increase in both the equivalent series resistance (ESR) and the overall capacitance value. The ESR enlargement is caused mainly an increase in the electrolyte resistance within pores which, in turn, results from a pore narrowing with ruthenium loading Hindered ionic motion in narrowed pores can explain this feature. An increase in the RC time constant with ruthenium loading is further verified by ac impedance measurements.

  7. Effect of nitrogen compounds on transport of ruthenium through the RCS.

    PubMed

    Kajan, Ivan; Kärkelä, Teemu; Auvinen, Ari; Ekberg, Christian

    2017-01-01

    Ruthenium is a fission product that can be released from the fuel in case of a severe nuclear accident. In this work the impact of the atmosphere composition, including air radiolysis products, on the transport of ruthenium through a primary circuit was examined. Experiments were performed at temperatures 1300, 1500 and 1700 K in a slightly humid air. In the experiments significant effect of nitrogen oxides (N2O, NO2) and nitric acid on the ruthenium chemistry in the model primary circuit was observed. The obtained results indicate a strong effect of air radiolysis products on the quantity partitioning of transported ruthenium to gaseous and aerosol compounds.

  8. Surface and sub-surface thermal oxidation of thin ruthenium films

    NASA Astrophysics Data System (ADS)

    Coloma Ribera, R.; van de Kruijs, R. W. E.; Kokke, S.; Zoethout, E.; Yakshin, A. E.; Bijkerk, F.

    2014-09-01

    A mixed 2D (film) and 3D (nano-column) growth of ruthenium oxide has been experimentally observed for thermally oxidized polycrystalline ruthenium thin films. Furthermore, in situ x-ray reflectivity upon annealing allowed the detection of 2D film growth as two separate layers consisting of low density and high density oxides. Nano-columns grow at the surface of the low density oxide layer, with the growth rate being limited by diffusion of ruthenium through the formed oxide film. Simultaneously, with the growth of the columns, sub-surface high density oxide continues to grow limited by diffusion of oxygen or ruthenium through the oxide film.

  9. Thermodynamic data bases for multivalent elements: An example for ruthenium

    SciTech Connect

    Rard, J.A.

    1987-11-01

    A careful consideration and understanding of fundamental chemistry, thermodynamics, and kinetics is absolutely essential when modeling predominance regions and solubility behavior of elements that exhibit a wide range of valence states. Examples of this are given using the ruthenium-water system at 298.15 K, for which a critically assessed thermochemical data base is available. Ruthenium exhibits the widest range of known aqueous solution valence states. Known solid anhydrous binary oxides of ruthenium are crystalline RuO/sub 2/, RuO/sub 4/, and possibly RuO/sub 3/ (thin film), and known hydroxides/hydrated oxides (all amorphous) are Ru(OH)/sub 3/ . H/sub 2/O, RuO/sub 2/ . 2H/sub 2/O, RuO/sub 2/ . H/sub 2/O, and a poorly characterized Ru(V) hydrous oxide. Although the other oxides, hydroxides, and hydrous oxides are generally obtained as precipitates from aqueous solutions, they are thermodynamically unstable with regard to RuO/sub 2/(cr) formation. Characterized aqueous species of ruthenium include RuO/sub 4/ (which slowly oxidizes water and which dissociates as a weak acid), RuO/sub 4//sup -/ and RuO/sub 4//sup 2 -/ (which probably contain lesser amounts of RuO/sub 3/(OH)/sub 2//sup -/ and RuO/sub 3/(OH)/sub 2//sup 2 -/, respectively, and other species), Ru(OH)/sub 2//sup 2 +/, Ru/sub 4/(OH)/sub 12//sup 4 +/, Ru(OH)/sub 4/, Ru/sup 3 +/, Ru(OH)/sup 2 +/, Ru(OH)/sub 2//sup +/, Ru/sup 2 +/, and some hydroxytetramers with formal ruthenium valences of 3.75 greater than or equal to Z greater than or equal to 2.0. Potential pH diagrams of the predominance regions change significantly with concentration due to polymerization/depolymerization reactions. Failure to consider the known chemistry of ruthenium can yield large differences in predicted solubilities.

  10. Molybdenum-99/technetium-99m management: race against time.

    PubMed

    Ahmad, Mushtaq

    2011-11-01

    Molybdenum-99 is a parent of diagnostic nuclear medicine. It decays to technetium-99m, which used in over 30 million investigations per year around the world. Supplies of Tc-99m remained fragile in the last few years, which may occur again in the short and long term. Few suggestions have been registered in this letter to cope inadequate supply of the most wanted radionuclide for patient care.

  11. Preparation, stability, and photoreactivity of thiolato ruthenium polypyridyl complexes: Can cysteine derivatives protect ruthenium-based anticancer complexes?

    PubMed

    van Rixel, Vincent H S; Busemann, Anja; Göttle, Adrien J; Bonnet, Sylvestre

    2015-09-01

    Ruthenium polypyridyl complexes may act as light-activatable anticancer prodrugs provided that they are protected by well-coordinated ligands that i) prevent coordination of other biomolecules to the metal center in the dark and ii) can be removed by visible light irradiation. In this paper, the use of monodentate thiol ligands RSH as light-cleavable protecting groups for the ruthenium complex [Ru(tpy)(bpy)(OH2)](PF6)2 ([1](PF6)2; tpy=2,2';6',2″-terpyridine, bpy=2,2'-bypyridine), is investigated. The reaction of [1](2+) with RSH=H2Cys (L-cysteine), H2Acys (N-acetyl-L-cysteine), and HAcysMe (N-acetyl-L-cysteine methyl ester), is studied by UV-visible spectroscopy, NMR spectroscopy, and mass spectrometry. Coordination of the monodentate thiol ligands to the ruthenium complex takes place upon heating to 353 K, but full conversion to the protected complex [Ru(tpy)(bpy)(SR)]PF6 is only possible when a large excess of ligand is used. Isolation and characterization of the two new thiolato complexes [Ru(tpy)(bpy)(κS-HCys)]PF6 ([2]PF6) and [Ru(tpy)(bpy)(κS-HAcys)]PF6 ([3]PF6) is reported. [3]PF6 shows a metal-to-ligand charge-transfer absorption band that is red shifted (λmax=492 nm in water) compared to its methionine analogue [Ru(tpy)(bpy)(κS-HAmet)](Cl)2 ([5](Cl)2, λmax=452 nm; HAmet=N-acetyl-methionine). In the dark the thiolate ligand coordinated to ruthenium is oxidized even by traces of oxygen, which first leads to the sulfenato, sulfinato, and disulfide ruthenium complexes, and finally to the formation of the aqua complex [1](2+). [3]PF6 showed slow photosubstitution of the thiolate ligand by water under blue light irradiation, together with faster photooxidation of the thiolate ligand compared to dark conditions. The use of thiol vs. thioether monodentate ligands is discussed for the protection of anticancer ruthenium-based prodrugs. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Complex of transferrin with ruthenium for medical applications

    DOEpatents

    Richards, Powell; Srivastava, Suresh C.; Meinken, George E.

    1984-05-15

    A novel Ruthenium-transferrin complex, prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40.degree. C. for about 2 hours, and purifying said complex by means of gel chromotography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparative results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex.

  13. Complex of transferrin with ruthenium for medical applications

    DOEpatents

    Richards, P.; Srivastava, S.C.; Meinken, G.E.

    1984-05-15

    A novel ruthenium-transferrin complex is disclosed which is prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40 C for about 2 hours. The complex is purified by means of gel chromotography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparative results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex. No Drawings

  14. The Growth of Monolayer Thin Films on a Ruthenium Surface

    NASA Astrophysics Data System (ADS)

    Bingham, Chris; Jones, Joshua; Karsten, Pohl

    2004-03-01

    Scanning Tunneling Microscopes (STMs) are able to acquire images of conductive surfaces with atomic resolution. At such a small scale even tiny impurities can affect the surface image making it necessary to perform STM experiments in an ultrahigh vacuum (10-11 Torr). An effective method for the cleaning of a Ruthenium sample will be developed through the use of a previously constructed sample holder, which contains a filament and a thermocouple to heat and measure sample temperature. Ruthenium samples will be flashed to a very high temperature (1700 K) very quickly in a low-pressure oxygen environment (10-8 Torr). Surface cleanliness will be measured by Auger Electron Spectroscopy (AES). Upon completion of a consistent method for surface cleaning, we deposit monolayer thick metal film such as copper, silver and gold by physical vapor deposition from tungsten baskets. Thickness, purity and atomic structure of the film will be measured using AES and STM.

  15. Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles

    SciTech Connect

    Berthoud, Romain; Delichere, Pierre; Gajan, David; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre; Coperet, Christophe

    2008-12-01

    Treatment under H{sub 2} at 300 C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Ru{sub p}/SiO{sub 2}], according to EXAFS, HRTEM and XPS. H{sub 2} adsorption measurements on [Ru{sub p}/SiO{sub 2}] in the absence of O{sub 2} show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Ru{sub s}) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In contrast, O{sub 2} adsorption on [Ru{sub p}/SiO{sub 2}] leads to a partial oxidation of the bulk at 25 C, to RuO{sub 2} at 200 C and to sintering upon further reduction under H{sub 2}, showing that O{sub 2} adsorption cannot be used to measure the dispersion of Ru particles.

  16. Is photoisomerization required for NO photorelease in ruthenium nitrosyl complexes?

    PubMed

    García, Juan Sanz; Alary, Fabienne; Boggio-Pasqua, Martial; Dixon, Isabelle M; Heully, Jean-Louis

    2016-11-01

    The factors that explain the competition between intramolecular NO linkage photoisomerization and NO photorelease in five ruthenium nitrosyl complexes were investigated. By applying DFT-based methods, it was possible to characterize the ground states and lowest triplet potential energy surfaces of these species, and to establish that both photoisomerization and photorelease processes can occur in the lowest triplet state of each species. This work highlights the crucial role of the sideways-bonded isomer, a metastable state also known as the MS2 isomer, in the photochemical loss of NO, while the results obtained also indicate that the population of the triplet state of this isomer is compulsory for both processes and show how photoisomerization and photorelease interfere. Graphical Abstract Illustration of the crucial role of the (3)MS2 state in the photoreactivities of ruthenium nitrosyl complexes.

  17. Determination of technetium-99 in aqueous samples by isotope dilution inductively coupled plasma-mass spectrometry

    SciTech Connect

    Beals, D.M.

    1992-09-01

    An isotope dilution/inductively coupled plasma mass spectrometric method (ID/ICP-MS) for measuring the concentration of technetium-99 in aqueous samples was developed at the Savannah River Technology Center (SRTC). The procedure is faster than radiometric techniques, is also less subject to interferences, and has equal or better detection limits. It is currently being used to measure the concentration of {sup 99}Tc in samples of Savannah River water collected in the vicinity of the Savannah River Site. In this method, one liter samples of water are spiked with {sup 97}Tc. After equilibration, the technetium is extracted from the sample with a chromatographic resin. Interfering elements, molybdenum and ruthenium, are either not retained by the resin or are washed off with dilute nitric acid. The technetium is then eluted with more concentrated nitric acid, and the {sup 99}Tc/{sup 97}Tc ratio in the eluant is measured with an ICP-MS. The {sup 99}Tc concentration in the original sample is calculated from the {sup 99}Tc/{sup 97}Tc ratio. The chemical recovery of the extraction procedure is greater than 90%. The detection limit of the instrument, taken as three times the background counts at m/z = 99, is 0.6 part per trillion (ppt). The detection limit of the procedure, taken as three times the standard deviation of several reagent blank analyses, is 0.33 pCi/L.

  18. Determination of technetium-99 in aqueous samples by isotope dilution inductively coupled plasma-mass spectrometry

    SciTech Connect

    Beals, D.M.

    1992-01-01

    An isotope dilution/inductively coupled plasma mass spectrometric method (ID/ICP-MS) for measuring the concentration of technetium-99 in aqueous samples was developed at the Savannah River Technology Center (SRTC). The procedure is faster than radiometric techniques, is also less subject to interferences, and has equal or better detection limits. It is currently being used to measure the concentration of {sup 99}Tc in samples of Savannah River water collected in the vicinity of the Savannah River Site. In this method, one liter samples of water are spiked with {sup 97}Tc. After equilibration, the technetium is extracted from the sample with a chromatographic resin. Interfering elements, molybdenum and ruthenium, are either not retained by the resin or are washed off with dilute nitric acid. The technetium is then eluted with more concentrated nitric acid, and the {sup 99}Tc/{sup 97}Tc ratio in the eluant is measured with an ICP-MS. The {sup 99}Tc concentration in the original sample is calculated from the {sup 99}Tc/{sup 97}Tc ratio. The chemical recovery of the extraction procedure is greater than 90%. The detection limit of the instrument, taken as three times the background counts at m/z = 99, is 0.6 part per trillion (ppt). The detection limit of the procedure, taken as three times the standard deviation of several reagent blank analyses, is 0.33 pCi/L.

  19. Characteristics of a promising new thermoelectric material - Ruthenium silicide

    NASA Technical Reports Server (NTRS)

    Ohta, Toshitaka; Vining, Cronin B.; Allevato, Camillo E.

    1991-01-01

    A preliminary study on arc-melted samples has indicated that ruthenium silicide has the potential to obtain figure-of-merit values four times higher than that of conventional silicon-germanium material. In order to realize the high figure-of-merit values, high-quality crystal from the melt is needed. A Bridgman-like method has been employed and has realized much better crystals than arc-melted ones.

  20. Arsenate adsorption on ruthenium oxides: A spectroscopic and kinetic investigation

    SciTech Connect

    Luxton, Todd P.; Eick, Matthew J.; Scheckel, Kirk G.

    2008-12-08

    Arsenate adsorption on amorphous (RuO{sub 2} {center_dot} 1.1H{sub 2}O) and crystalline (RuO{sub 2}) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was used to determine the local coordination environment of adsorbed arsenate. Additionally, pressure-jump (p-jump) relaxation spectroscopy was used to investigate the kinetics of arsenate adsorption/desorption on ruthenium oxides. Chemical relaxations resulting from the induced pressure change were monitored via electrical conductivity detection. EXAFS data were collected for two initial arsenate solution concentrations, 3 and 33 mM at pH 5. The collected spectra indicated a similar coordination environment for arsenate adsorbed to RuO{sub 2} {center_dot} 1.1H{sub 2}O for both arsenate concentrations. In contrast the EXAFS spectra of RuO{sub 2} indicated differences in the local coordination environments for the crystalline material with increasing arsenate concentration. Data analysis indicated that both mono- and bidentate surfaces complexes were present on both RuO{sub 2} {center_dot} 1.1H{sub 2}O and RuO{sub 2}. Relaxation spectra from the pressure-jump experiments of both ruthenium oxides resulted in a double relaxation event. Based on the relaxation spectra, a two step reaction mechanism for arsenate adsorption is proposed resulting in the formation of a bidentate surface complex. Analysis of the kinetic and spectroscopic data suggested that while there were two relaxation events, arsenate adsorbed to ruthenium oxide surfaces through both mono- and bidentate surface complexes.

  1. Ruthenium-97 hepatobiliary agents for delayed studies of the bilary tract I: Ru-97 PIPIDA: concise communication

    SciTech Connect

    Schachner, E.R.; Gil, M.C.; Atkins, H.L.; Som, P.; Srivastava, S.C.; Badia, J.; Sacker, D.F.; Fairchild, R.G.; Richards, P.

    1981-04-01

    Failure of early diagnosis of biliary atresia results in the development of cirrhosis and death. Commonly used hepatobiliary agents are not ideal for follow-up studies because of their unfavorable physical properties or short half-life. The excellent physical properties of Ru-97 should overcome these limitations. Therefore, Ru-97 PIPIDA (N,..cap alpha..-(p-isopropyl acetanilide) iminoacetic acid) is being investigated as a potential hepatobiliary agent that would allow an improved diagnosis of the disease. Ruthenium-97 PIPIDA and Tc-99m PIPIDA showed similar blood clearance rates in dogs. Ru-97 PIPIDA scintigrams in dogs showed early uptake in liver and gallbladder and slow excretion through the gastrointestinal tract. Biodistribution studies were performed in normal rats and rats with biliary obstruction. The findings suggest that Ru-97 PIPIDA should be useful for delayed studies ( 1 to 3 days) of the biliary tract.

  2. Electrochemical deposition of conducting ruthenium oxide films from solution

    SciTech Connect

    Anderson, D.P.; Warren, L.F.

    1984-02-01

    In the last decade, ruthenium oxide, RuO /sub x/ (x less than or equal to 2), has been used extensively as the active anode electrocatalyst constituent for Cl/sub 2/ and O/sub 2/ evolution reactions, in chlorate production, and in metal electrowinning from mixed chloride-sulfate solutions. More recently, this material has been incorporated in several light-induced water electrolysis schemes and apparently possesses the ability to inhibit CdS photocorrosion by acting as a hole scavenger. The numerous applications for this catalyst material certainly warrant further studies of its electrochemical properties on a variety of substrates, e.g., semiconductors. The lack of a simple technique for controlled deposition of ruthenium oxide onto conducting substrates prompted us to investigate an electrochemical approach to this problem. We describe here a new way to electrochemically deposit conducting films of hydrated ruthenium oxide from an aqueous solution of the benzeneruthenium (II)aqua complex. The films slowly dissolve in aqueous electrolytes upon potential cycling, yet appear to be catalytic with regards to water oxidation.

  3. Thin film ruthenium microstructures for transition edge sensors

    NASA Astrophysics Data System (ADS)

    Ilin, A. S.; Cohn, I. A.; Vystavkin, A. N.; Kovalenko, A. G.

    2016-12-01

    The superconducting properties of ruthenium (Ru) thin films and microstructures are investigated. The microstructures are used as transition edge sensors (TES), working at He-3 evaporation cryostats' temperatures. Ruthenium is substantially inert, and the critical temperature Tc for bulk Ru samples is known from state of art to be 0.40-0.51 K. We investigated magnetron sputtered Ru thin films with thicknesses 13-300 nm on a Si substrate and electron lithography fabricated TES samples, based on the thin-film Ru microstructures. It has been found, that the Tc for the Ru thin films is 0.55-0.70 K, and the width of the transition region is 1-5 mK, and for the Ru TES Tc = 0.55 and ΔT = 4 mK. Furthermore, it was established that lithography process had no significant influence on the properties of the TES samples, so we were able to get consistent properties for several fabrication sessions. Therefore ruthenium is concluded to be a desirable material for transition edge sensors working at He-3 cryostats' temperatures.

  4. The Mystery of the Electronic Spectrum of Ruthenium Monophosphide

    NASA Astrophysics Data System (ADS)

    Adam, Allan G.; Christensen, Ryan M.; Dore, Jacob M.; Konder, Ricarda M.; Tokaryk, Dennis W.

    2016-06-01

    Using PH3 as a reactant gas and ruthenium as the target metal in the UNB laser ablation spectrometer, the ruthenium monophosphide molecule (RuP) has been detected. Dispersed fluorescence experiments have been performed to determine ground state vibrational frequencies and the presence of any low-lying electronic states. Rotationally resolved spectra of two vibrational bands at 577nm and 592nm have been taken; the bands have been identified as 1-0 and 0-0 bands based on isotopic shifts. Ruthenium has seven stable isotopes and rotational transitions have been observed for six of the RuP isotopologues. RuP is isoelectronic to RuN so it is expected that RuP will have a 2Σ+ ground state and low resolution spectra indicated a likely 2Σ+ - 2Σ+ electronic transition. Further investigation has led us to believe we are observing a 2Π - 2Σ+ transition but mysteriously some important rotational branches are missing. It is hoped that new data to be recorded on a second electronic system we have observed at 535nm will help shed light on this mystery.

  5. Vibrational Spectroscopic Studies of Hydrogen, Carbon-Monoxide and Thiophene Adsorption on Ruthenium-Sulfide and Sulfided Ruthenium Catalysts.

    NASA Astrophysics Data System (ADS)

    Heise, William Herbert

    The "working surface" of ruthenium hydrodesulfurization (HDS) catalysts has been modeled by preadsorption of sulfur, carbon and carbon plus sulfur on Ru(0001). Adsorption and decomposition of thiophene over these surfaces have been investigated using TDS/TPRS, XPS and EELS. Thiophene is proposed to decompose via a three-step mechanism involving: (i) initial thiophene cracking at 120 K yielding surface sulfur and hydrocarbon species, (ii) hydrogen desorption near 230 K providing additional decomposition ensembles and (iii) continued decomposition to form "metallocycle -like" intermediates which retain EELS features similar to thiophene. Preadsorbed carbon or carbon plus sulfur are not as effective for passivation of the surface toward metallocycle formation as preadsorbed sulfur alone. This result is attributed to the fact that carbon deposited from butadiene annealed and decomposed at 700 K forms islands, while sulfur establishes a well-ordered superlattice on the surface. The decrease in metallocycle formation with increasing poison levels appears to explain HDS selectivity and specific activity trends observed in our laboratory from mildly sulfided (10% H_2S/H_2 , 673 K, 2h) ruthenium catalysts retaining submonolayers of sulfur. Incoherent inelastic neutron scattering (IINS) has been used to characterize hydrogen adsorption sites on ruthenium sulfide. Hydrogen resides on sulfur anions to form SH groups, yielding two non-degenerate bending modes at 600 and 710 cm^{-1}. Complementary hydrogen adsorption and H_2/D _2 exchange data suggest that the active sites for hydrogen adsorption may be coordinatively unsaturated S-S anion pairs. Comparison of CO adsorption on sulfided Ru/Al _2O_3 to sulfur precovered Ru(0001) reveals an adsorption site related to edge/corner atoms directly perturbed by sulfur, consistent with previous kinetic studies demonstrating higher specific activity for thiophene HDS over smaller ruthenium crystallites.

  6. Ruthenium-Catalyzed Ammonia Borane Dehydrogenation: Mechanism and Utility.

    PubMed

    Zhang, Xingyue; Kam, Lisa; Trerise, Ryan; Williams, Travis J

    2017-01-17

    One of the greatest challenges in using H2 as a fuel source is finding a safe, efficient, and inexpensive method for its storage. Ammonia borane (AB) is a solid hydrogen storage material that has garnered attention for its high hydrogen weight density (19.6 wt %) and ease of handling and transport. Hydrogen release from ammonia borane is mediated by either hydrolysis, thus giving borate products that are difficult to rereduce, or direct dehydrogenation. Catalytic AB dehydrogenation has thus been a popular topic in recent years, motivated both by applications in hydrogen storage and main group synthetic chemistry. This Account is a complete description of work from our laboratory in ruthenium-catalyzed ammonia borane dehydrogenation over the last 6 years, beginning with the Shvo catalyst and resulting ultimately in the development of optimized, leading catalysts for efficient hydrogen release. We have studied AB dehydrogenation with Shvo's catalyst extensively and generated a detailed understanding of the role that borazine, a dehydrogenation product, plays in the reaction: it is a poison for both Shvo's catalyst and PEM fuel cells. Through independent syntheses of Shvo derivatives, we found a protective mechanism wherein catalyst deactivation by borazine is prevented by coordination of a ligand that might otherwise be a catalytic poison. These studies showed how a bidentate N-N ligand can transform the Shvo into a more reactive species for AB dehydrogenation that minimizes accumulation of borazine. Simultaneously, we designed novel ruthenium catalysts that contain a Lewis acidic boron to replace the Shvo -OH proton, thus offering more flexibility to optimize hydrogen release and take on more general problems in hydride abstraction. Our scorpionate-ligated ruthenium species (12) is a best-of-class catalyst for homogeneous dehydrogenation of ammonia borane in terms of its extent of hydrogen release (4.6 wt %), air tolerance, and reusability. Moreover, a synthetically

  7. Analysis of the cytotoxic effects of ruthenium-ketoconazole and ruthenium-clotrimazole complexes on cancer cells

    PubMed Central

    Robles-Escajeda, Elisa; Martínez, Alberto; Varela-Ramirez, Armando; Sánchez-Delgado, Roberto A.; Aguilera, Renato J.

    2014-01-01

    Ruthenium-based compounds have intriguing anti-cancer properties and some of these novel compounds are currently in clinical trials. To continue the development of new metal-based drug combinations, we coupled ruthenium (Ru) with the azole compounds ketoconazole (KTZ) and clotrimazole (CTZ), which are well-known antifungal agents that also display anticancer properties. We report the activity of a series of twelve Ru-KTZ and Ru-CTZ compounds against three prostate tumor cell lines with different androgen sensitivity, as well as cervical cancer and lymphoblastic lymphoma cell lines. In addition, human cell lines were used to evaluate the toxicity against non-transformed cells and to establish selectivity indexes. Our results indicate that the combination of ruthenium and KTZ/CTZ in a single molecule results in complexes that are more cytotoxic than the individual components alone, displaying in some cases low micromolar CC50 values and high selectivity indexes. Additionally, all compounds are more cytotoxic against prostate cell lines with lower cytotoxicity against non-transformed epidermal cell lines. Some of the compounds were found to primarily induce cell death via apoptosis yet weakly interact with DNA. Our studies also demonstrate that the cytotoxicity induced by our Ru-based compounds is not directly related to their ability to interact with DNA. PMID:24272524

  8. Biennial Report, 1997-99.

    ERIC Educational Resources Information Center

    Wisconsin Technical Coll. System Board, Madison.

    This report describes the 1997-99 biennium activities of the Wisconsin Technical College System (WTCS) Board. Part 1 provides an Agency Overview. Details are given on mission and purpose, cooperative relationships, the State Board, the State Board Staff, and WTCS Districts. Part 2 explores the 1997-99 Budget and Policy Actions. It discusses the…

  9. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  10. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    EPA Science Inventory

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  11. Ruthenium catalyzed synthesis of 2,3-unsaturated C-glycosides from glycals.

    PubMed

    Srinivas, Batthula; Reddy, Thurpu Raghavender; Kashyap, Sudhir

    2015-04-10

    A highly efficient and convenient C-glycosylation method was developed using ruthenium(III) chloride for the synthesis of 2,3-unsaturated C-glycosides. Various nucleophiles such as allyl trimethylsilane, triethylsilane, trimethylsilyl cyanide, trimethylsilyl azide and heterocycles such as thiophene and furan reacted smoothly with glycals in the presence of catalytic amount of ruthenium trichloride under mild reaction conditions.

  12. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  13. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    EPA Science Inventory

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  14. Thermochemistry of Ruthenium Oxyhydroxide Species and Their Impact on Volatile Speciations in Severe Nuclear Accident Conditions.

    PubMed

    Miradji, Faoulat; Virot, François; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2016-02-04

    Literature thermodynamic data of ruthenium oxyhydroxides reveal large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. Reaction energies leading to the formation of all possible oxyhydroxide species RuOx(OH)y(H2O)z have been calculated for a series of reactions combining DFT (TPSSh-5%HF) geometries and partition functions, CCSD(T) energies extrapolated to the complete basis set limits. The highly accurate ab initio thermodynamic data were used as input data of thermodynamic equilibrium computations to derive the speciation of gaseous ruthenium species in the temperature, pressure and concentration conditions of severe nuclear accidents occurring in pressurized water reactors. At temperatures lower than 1000 K, gaseous ruthenium tetraoxide is the dominating species, between 1000 and 2000 K ruthenium trioxide becomes preponderant, whereas at higher temperatures gaseous ruthenium oxide, dioxide and even Ru in gaseous phase are formed. Although earlier studies predicted the formation of oxyhydroxides in significant quantities, the use of highly accurate ab initio thermodynamic data for ruthenium gaseous species leads to a more reliable inventory of gaseous ruthenium species in which gaseous oxyhydroxide ruthenium molecules are formed only in negligible amounts.

  15. Using ruthenium sawhorse based decarboxylation to produce industrial materials from oleic acid

    USDA-ARS?s Scientific Manuscript database

    Ruthenium catalyzed isomerization and decarboxylation of 9-cis-octadecenoic acid are reported as part of the effort to produce valuable industrial materials from biobased sources. Initial studies have demonstrated the efficacy of ruthenium sawhorse materials and further mechanistic studies uncovered...

  16. Ruthenium-based nitric oxide-donating and carbon monoxide-donating molecules.

    PubMed

    Pauwels, Bart; Boydens, Charlotte; Vanden Daele, Laura; Van de Voorde, Johan

    2016-03-01

    Over the past few years, the use of metallocomplexes for medical purposes has considerably grown. Because of its favourable characteristics, ruthenium has taken a significant place in this expanding field of research. Several ruthenium-containing metal compounds have been developed as delivery agents of physiological important molecules such as nitric oxide (NO) and carbon monoxide (CO). This review focuses on the (vaso)relaxant capacity of ruthenium-based NO-donating and CO-donating molecules in view of their potential usefulness in the treatment of cardiovascular diseases and erectile dysfunction. Ruthenium seems to be a valuable candidate for the design of NO-donating and CO-donating molecules. To date, ruthenium remains of interest in drug research as the search for new alternatives is still necessary. © 2016 Royal Pharmaceutical Society.

  17. Structure of ruthenium(II) complexes with coproporphyrin I tetraethyl ester

    NASA Astrophysics Data System (ADS)

    Zverev, S. A.; Andreev, S. V.; Zamilatskov, I. A.; Kurochkina, N. M.; Tyurin, V. S.; Senchikhin, I. N.; Ponomarev, G. V.; Erzina, D. R.; Chernyshev, V. V.

    2017-08-01

    The reaction between coproporphyrin I tetraethyl ester and ruthenium(II) dodecacarbonyl in toluene is investigated. The formation of two different products, complexes 2 and 3 of ruthenium(II) with coproporphyrin I tetraethyl ester, studied by means of mass spectrometry, electronic absorption spectroscopy, NMR, X-ray diffraction, and thermogravimetric analysis, is revealed. Structures are proposed for the products, of which ( 2) is a monocarbonyl complex of ruthenium(II) porphyrin that exists as a coordination polymer formed owing to intermolecular axial bonding between the oxygen atoms of carboethoxyl groups and ruthenium(II). The structure proposed for second product ( 3) is in the form of the corresponding monomer of a monocarbonyl complex of ruthenium(II) porphyrin. It is established that polymeric complex 2 transforms into monomeric complex 3 when it is heating in pyridine.

  18. New cholescintigraphic agent: ruthenium-97-DISIDA

    SciTech Connect

    Zanzi, I.; Srivastava, S.C.; Meinken, G,E.; Robeson, W.; Mausner, L.F.; Fairchild, R.G.; Margouleff, D.

    1986-06-01

    These studies demonstrate the first application of Ru-97-DISIDA in human subjects. High quality images were obtained. Scintigraphic findings in patients with hepatobiliary disorders were consistent with the biodistribution data obtained in experinmental animals and with other imaging procedures and clinical findings. Administration of Ru-97-DISIDA I.V. and of a solid test meal labeled with Tc-99m-Sulfur Colloid allowed simulateneous detection and quantification of deodenogastric reflux and determination of the gastric emptying rate. This represents an advantage as compared to the currently used techniques which necessitate two separate studies if a solid meal is used, or would mandate a liquid meal for a simultaneous study. The excellent nuclear decay characteristics of Ru-97 (tl/2 69.6 h, gamma 216 keV, 86%, no betas) permit delayed study of the hepatobiliary system with considerably less radiation exposure than I-131 Rose Bengal and with a marked improvement in image quality. 5 refs., 3 figs., 3 tabs.

  19. Mononuclear ruthenium polypyridine complexes that catalyze water oxidation

    PubMed Central

    2016-01-01

    Over the past decade, significant advances have been made in the development of molecular water oxidation catalysts (WOCs) in the context of developing a system that would accomplish artificial photosynthesis. Mononuclear ruthenium complexes with polypyridine ligands have drawn considerable attention in this regard, due to their high catalytic activity and relatively simple structure. In this perspective review, we will discuss mononuclear Ru polypyridine WOCs by organizing them into four groups according to their ligand environments. Each group will be discussed with regard to three fundamental questions: first, how does the catalyst initiate O–O bond formation? Second, which step in the catalytic cycle is rate-determining? Third, how efficient is the catalyst according to the specific descriptors such as turnover frequency? All discussion is based on the high-valent ruthenium intermediates that are proposed in the catalytic cycle according to experimental observation and theoretical simulation. Two fundamental mechanisms are set forth. An acid–base mechanism that involves the attack of a water molecule on the oxo of a high valent Ru 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000

  20. Graphene-Ruthenium(II) complex composites for sensitive ECL immunosensors.

    PubMed

    Xiao, Fang-Nan; Wang, Min; Wang, Feng-Bin; Xia, Xing-Hua

    2014-02-26

    Non-covalent modification method has been proven as an effective strategy for enhancing the chemical properties of graphene while the structure and electronic properties of graphene can be retained. This work describes a novel strategy to fabricate a solid-state electrochemiluminescent (ECL) immunosensor based on ruthenium(II) complex/3,4,9,10-perylenetetracarboxylic acid (PTCA)/graphene nanocomposites (Ru-PTCA/G) for sensitive detection of α-fetoprotein (AFP). It is found that immobilization of PTCA and reduction of GO can be simultaneously achieved in one-pot synthesis method under alkaline condition and moderate temperature, forming PTCA/G nanocomposites. Further covalent attachment of ruthenium(II) complex to the PTCA assembled on graphene sheets produces the functional Ru-PTCA/G nanocomposites which show good electrochemical activity and ca. 21 times higher luminescence quantum efficiency than the adsorbed derivative ruthenium(II) complex. The Ru-PTCA/G nanocomposites based solid-state ECL sensor exhibits high stability toward the determination of tripropylamine (TPA) coreactant. In addition, a new ECL immunosensor based on steric hindrance effect is fabricated by cross-linking α-fetoprotein antibody (anti-AFP) with chitosan covered on Ru-PTCA/G composites modified electrode for detection of cancer biomarker AFP. This ECL immunosensor shows an extremely sensitive response to AFP in a linear range of 5 pg·mL(-1) -10 ng·mL(-1) with a detection limit of 0.2 pg·mL(-1) . The present approach is effective for various molecules immobilization and may become a promising technique for biomolecular detection.

  1. Antiparasitic activities of novel ruthenium/lapachol complexes.

    PubMed

    Barbosa, Marília I F; Corrêa, Rodrigo S; de Oliveira, Katia Mara; Rodrigues, Claudia; Ellena, Javier; Nascimento, Otaciro R; Rocha, Vinícius P C; Nonato, Fabiana R; Macedo, Taís S; Barbosa-Filho, José Maria; Soares, Milena B P; Batista, Alzir A

    2014-07-01

    The present study describes the synthesis, characterization, antileishmanial and antiplasmodial activities of novel diimine/(2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,4'-methylbipyridine (Me-bipy) and 4,4'-methoxybipyridine (MeO-bipy)/phosphine/ruthenium(II) complexes containing lapachol (Lap, 2-hydroxy-3-(3-33 methyl-2-buthenyl)-1,4-naphthoquinone) as bidentate ligand. The [Ru(Lap)(PPh3)2(bipy)]PF6 (1), [Ru(Lap)(PPh3)2(Me-bipy)]PF6 (2), [Ru(Lap)(PPh3)2(MeO-bipy)]PF6(3) and[Ru(Lap)(PPh3)2(phen)]PF6 (4) complexes, PPh3=triphenylphospine, were synthesized from the reactions of cis-[RuCl2(PPh3)2(X-bipy)] or cis-[RuCl2(PPh3)2(phen)], with lapachol. The [RuCl2(Lap)(dppb)] (5) [dppb=1,4-bis(diphenylphosphine)butane] was synthesized from the mer-[RuCl3(dppb)(H2O)] complex. The complexes were characterized by elemental analysis, molar conductivity, infrared and UV-vis spectroscopy, (31)P{(1)H} and (1)H NMR, and cyclic voltammetry. The Ru(III) complex, [RuCl2(Lap)(dppb)], was also characterized by the EPR technique. The structure of the complexes [Ru(Lap)(PPh3)2(bipy)]PF6 and [RuCl2(Lap)(dppb)] was elucidated by X-ray diffraction. The evaluation of the antiparasitic activities of the complexes against Leishmania amazonensis and Plasmodium falciparum demonstrated that lapachol-ruthenium complexes are more potent than the free lapachol. The [RuCl2(Lap)(dppb)] complex is the most potent and selective antiparasitic compound among the five new ruthenium complexes studied in this work, exhibiting an activity comparable to the reference drugs.

  2. Gas-phase chemistry of ruthenium and rhodium carbonyl complexes.

    PubMed

    Cao, Shiwei; Wang, Yang; Qin, Zhi; Fan, Fangli; Haba, Hiromitsu; Komori, Yukiko; Wu, Xiaolei; Tan, Cunmin; Zhang, Xin

    2016-01-07

    Short-lived ruthenium and rhodium isotopes were produced from a (252)Cf spontaneous fission (SF) source. Their volatile carbonyl complexes were formed in gas-phase reactions in situ with the carbon-monoxide containing gas. A gas-jet system was employed to transport the volatile carbonyls from the recoil chamber to the chemical separation apparatus. The gas-phase chemical behaviors of these carbonyl complexes were studied using an online low temperature isothermal chromatography (IC) technique. Long IC columns made up of FEP Teflon were used to obtain the chemical information of the high-volatile Ru and Rh carbonyls. By excluding the influence of precursor effects, short-lived isotopes of (109-110)Ru and (111-112)Rh were used to represent the chemical behaviours of Ru and Rh carbonyls. Relative chemical yields of about 75% and 20% were measured for Ru(CO)5 and Rh(CO)4, respectively, relative to the yields of KCl aerosols transported in Ar gas. The adsorption enthalpies of ruthenium and rhodium carbonyl complexes on a Teflon surface were determined to be around ΔHads = -33(+1)(-2) kJ mol(-1) and -36(+2)(-1) kJ mol(-1), respectively, by fitting the breakthrough curves of the corresponding carbonyl complexes with a Monte Carlo simulation program. Different from Mo and Tc carbonyls, a small amount of oxygen gas was found to be not effective for the chemical yields of ruthenium and rhodium carbonyl complexes. The general chemical behaviors of short-lived carbonyl complexes of group VI-IX elements were discussed, which can be used in the future study on the gas-phase chemistry of superheavy elements - Bh, Hs, and Mt carbonyls.

  3. Anticancer activity of structurally related ruthenium(II) cyclopentadienyl complexes.

    PubMed

    Côrte-Real, Leonor; Mendes, Filipa; Coimbra, Joana; Morais, Tânia S; Tomaz, Ana Isabel; Valente, Andreia; Garcia, M Helena; Santos, Isabel; Bicho, Manuel; Marques, Fernanda

    2014-08-01

    A set of structurally related Ru(η(5)-C5H5) complexes with bidentate N,N'-heteroaromatic ligands have been evaluated as prospective metallodrugs, with focus on exploring the uptake and cell death mechanisms and potential cellular targets. We have extended these studies to examine the potential of these complexes to target cancer cell metabolism, the energetic-related phenotype of cancer cells. The observations that these complexes can enter cells, probably facilitated by binding to plasma transferrin, and can be retained preferentially at the membranes prompted us to explore possible membrane targets involved in cancer cell metabolism. Most malignant tumors present the Warburg effect, which consists in increasing glycolytic rates with production of lactate, even in the presence of oxygen. The reliance of glycolytic cancer cells on trans-plasma-membrane electron transport (TPMET) systems for their continued survival raises the question of their appropriateness as a target for anticancer drug development strategies. Considering the interesting findings that some anticancer drugs in clinical use are cytotoxic even without entering cells and can inhibit TPMET activity, we investigated whether redox enzyme modulation could be a potential mechanism of action of antitumor ruthenium complexes. The results from this study indicated that ruthenium complexes can inhibit lactate production and TPMET activity in a way dependent on the cancer cell aggressiveness and the concentration of the complex. Combination approaches that target cell metabolism (glycolytic inhibitors) as well as proliferation are needed to successfully cure cancer. This study supports the potential use of some of these ruthenium complexes as adjuvants of glycolytic inhibitors in the treatment of aggressive cancers.

  4. Progress in doping of ruthenium silicide (Ru2Si3)

    NASA Technical Reports Server (NTRS)

    Vining, C. B.; Allevato, C. E.

    1992-01-01

    Ruthenium silicide is currently under development as a promising thermoelectric material suitable for space power applications. Key to realizing the potentially high figure of merit values of this material is the development of appropriate doping techniques. In this study, manganese and iridium have been identified as useful p- and n-type dopants, respectively. Resistivity values have been reduced by more than 3 orders of magnitude. Anomalous Hall effect results, however, complicate interpretation of some of the results and further effort is required to achieve optimum doping levels.

  5. Ruthenium Behavior at Phase Separation of Borosilicate Glass-12259

    SciTech Connect

    Enokida, Youichi; Sawada, Kayo

    2012-07-01

    The Rokkasho reprocessing plant (RRP) located in Aomori, Japan, vitrifies high level waste (HLW) into a borosilicate glass. The HLW is generated from the reprocessing of spent fuel and contains ruthenium (Ru) and other platinum group metals (PGMs). Based on the recent consequences after a huge earthquake that occurred in Japan, a hypothetical blackout was postulated for the RRP to address additional safety analysis requirements. During a prolonged blackout, the borosilicate glass could phase separate due to cooling of the glass in the melter. The Ru present in the glass matrix could migrate into separate phases and impact the durability of the borosilicate glass. The durability of the glass is important for quality assurance and performance assessment of the vitrified HLW. A fundamental study was performed at an independent university to understand the impact of a prolonged blackout. Simulated HLW glasses were prepared for the RRP, and the Ru behavior in phase separated glasses was studied. The simulated HLW glasses contained nonradioactive elements and PGMs. The glass compositions were then altered to enhance the formation of the phase-separated glasses when subjected to thermal treatment at 700 deg. C for 24 hours. The synthesized simulated glasses contained 1.1 % Ru by weight as ruthenium dioxide (RuO{sub 2}). A portion of the RuO{sub 2} formed needle-shaped crystals in the glass specimens. After the thermal treatment, the glass specimen had separated into two phases. One of the two phases was a B{sub 2}O{sub 3} rich phase, and the other phase was a SiO{sub 2} rich phase. The majority of the chemical species in the B{sub 2}O{sub 3} rich phase was leached away with the Material Characterization Center-3 (MCC-3) protocol standardized by the Pacific Northwest National Laboratory using an aqueous low-concentrated nitric acid solution, but the leaching of the Ru fraction was very limited; less than 1% of the original Ru content. The Ru leaching was much less than

  6. The solubility of hydrogen in rhodium, ruthenium, iridium and nickel.

    NASA Technical Reports Server (NTRS)

    Mclellan, R. B.; Oates, W. A.

    1973-01-01

    The temperature variation of the solubility of hydrogen in rhodium, ruthenium, iridium, and nickel in equilibrium with H2 gas at 1 atm pressure has been measured by a technique involving saturating the solvent metal with hydrogen, quenching, and analyzing in resultant solid solutions. The solubilities determined are small (atom fraction of H is in the range from 0.0005 to 0.00001, and the results are consistent with the simple quasi-regular model for dilute interstitial solid solutions. The relative partial enthalpy and excess entropy of the dissolved hydrogen atoms have been calculated from the solubility data and compared with well-known correlations between these quantities.

  7. Chiral-auxiliary-mediated asymmetric synthesis of ruthenium polypyridyl complexes.

    PubMed

    Gong, Lei; Wenzel, Marianne; Meggers, Eric

    2013-11-19

    An octahedral metal complex with 6 different monodentate ligands can form 15 diastereomers as pairs of enantiomers. As a result, the elaborate stereochemistry of octahedral coordination geometries provides tremendous opportunities in the fields of catalysis, the materials sciences, and the life sciences. The demand for enantiomerically pure coordination complexes for tasks related to the selective molecular recognition of biomacromolecules led us to develop synthetic methods to control the absolute stereochemistry at octahedral metal centers. A few years ago our laboratory therefore embarked on a project exploring new and general synthetic strategies for the asymmetric synthesis of inert octahedral transition metal complexes. We initially used the example of thermally inert ruthenium polypyridyl complexes and developed a family of chiral bidentate ligands, including salicyloxazolines, (mercaptophenyl)oxazolines, sulfinylphenols, N-acetylsulfinamides, a phosphinohydroxybinaphthyl, and even the amino acid proline to serve as chiral auxiliaries for asymmetric coordination chemistry. All these chiral auxiliaries strongly coordinate to ruthenium(II) in a bidentate, deprotonated fashion, allowing them to control the absolute metal-centered configuration in the course of subsequent ligand exchange reactions. Finally, we can remove them from the metal without any loss of chiral information and without leaving a chemical trace. A key feature of these chiral auxiliary ligands is their switchable binding strength. A chelate effect ensures that the chiral ligands coordinate very tightly to the metal center, placing their carbon-based, sulfur-based, or axial chirality in a well-defined position close to the metal center to efficiently establish the absolute metal-centered configuration. At the same time a coordinating phenolate, carboximidate, carboxylate, or thiophenolate moiety makes the coordination reversible by weakening the binding strength through protonation or

  8. Progress in doping of ruthenium silicide (Ru2Si3)

    NASA Technical Reports Server (NTRS)

    Vining, C. B.; Allevato, C. E.

    1992-01-01

    Ruthenium silicide is currently under development as a promising thermoelectric material suitable for space power applications. Key to realizing the potentially high figure of merit values of this material is the development of appropriate doping techniques. In this study, manganese and iridium have been identified as useful p- and n-type dopants, respectively. Resistivity values have been reduced by more than 3 orders of magnitude. Anomalous Hall effect results, however, complicate interpretation of some of the results and further effort is required to achieve optimum doping levels.

  9. Thermal properties of ruthenium alkylidene-polymerized dicyclopentadiene

    PubMed Central

    Vidavsky, Yuval; Navon, Yotam; Ginzburg, Yakov; Gottlieb, Moshe

    2015-01-01

    Summary Differential scanning calorimetry (DSC) analysis of ring opening methatesis polymerization (ROMP) derived polydicyclopentadiene (PDCPD) revealed an unexpected thermal behavior. A recurring exothermic signal can be observed in the DSC analysis after an elapsed time period. This exothermic signal was found to be proportional to the resting period and was accompanied by a constant increase in the glass-transition temperature. We hypothesize that a relaxation mechanism within the cross-linked scaffold, together with a long-lived stable ruthenium alkylidene species are responsible for the observed phenomenon. PMID:26425203

  10. First polymer "ruthenium-cyclopentadienyl" complex as potential anticancer agent.

    PubMed

    Valente, Andreia; Garcia, Maria Helena; Marques, Fernanda; Miao, Yong; Rousseau, Cyril; Zinck, Philippe

    2013-10-01

    d-glucose end-capped polylactide ruthenium cyclopentadienyl complex (RuPMC) was newly synthesized by a straightforward method. RuPMC was tested against human MCF7 and MDAMB231 breast and A2780 ovarian adenocarcinoma revealing IC50 values in the micromolar range. A pH dependent hydrolysis is advanced by preliminary UV-visible spectroscopy. Cellular distribution studies showed that RuPMC is predominantly found in the nucleus and in the membrane. Data suggest potential application of RuPMC as a new drug delivery system for Ru(II)Cp compounds. © 2013.

  11. Threading of Binuclear Ruthenium Complex Through DNA Bases

    NASA Astrophysics Data System (ADS)

    Paramanathan, Thayaparan; Westerlund, Fredrik; McCauley, Micah; Lincoln, Per; Rouzina, Ioulia; Williams, Mark

    2009-03-01

    Due to steric constraints the dumb-bell shaped binuclear ruthenium complex can only intercalate DNA by threading, which requires local melting of the DNA to occur. By mechanically manipulating a single DNA molecule held with optical tweezers, we lower the barrier to threading compared to bulk experiments. Stretching single DNA molecules with different drug concentrations and holding a constant force allows the binding to reach equilibrium. We can obtain the equilibrium fractional ligand binding and length of DNA at saturation. Fitting these results yields quantitative measurements of the binding thermodynamics and kinetics. In addition, we obtain the minimum binding site size, which may be determined by either electrostatic repulsion or steric constraints.

  12. Ruthenium-catalyzed selective monoamination of vicinal diols.

    PubMed

    Bähn, Sebastian; Tillack, Annegret; Imm, Sebastian; Mevius, Kathleen; Michalik, Dirk; Hollmann, Dirk; Neubert, Lorenz; Beller, Matthias

    2009-01-01

    The monoamination of vicinal diols in the presence of in situ generated ruthenium catalysts has been investigated. Among the various phosphines tested in combination with [Ru(3)(CO)(12)], N-phenyl-2-(dicyclohexyl-phosphanyl)pyrrole showed the best performance. After optimization of the reaction conditions this system was applied to different secondary amines and anilines as well as a number of vicinal diols. With the exception of ethylene glycol, monoamination of the vicinal diols occurred selectively and the corresponding amino alcohols were obtained in good yields, producing water as the only side product.

  13. Microscopic Understanding of Fischer-Tropsch Synthesis on Ruthenium

    SciTech Connect

    Chavez, Donna L.

    2014-10-01

    Total energy calculations and scanning tunneling microscope (STM) image simulations were conducted in an effort to interpret new experimental images of CO and H adsorbed on the closepacked surface of ruthenium metal. The images are remarkable in suggesting that the adsorbed species are intermixed, plausibly accounting for the superior catalytic activity of this metal in forming hydrocarbons. Insight was gained over the short duration of the project, but a more accurate method of simulating images will be required before contact between theory and experiment points to a final result.

  14. Ruthenium Complexes: An Emerging Ground to the Development of Metallopharmaceuticals for Cancer Therapy.

    PubMed

    Abid, Mohammad; Shamsi, Farheen; Azam, Amir

    2016-01-01

    GLOBOCAN 2012 estimates 14.1 million new cancer cases and 8.2 million cancer-related deaths worldwide. Cancer is rapidly becoming a major public health concern in India as well, with the number of new cancer cases anticipated to double within the next 20 years. The percentage of currently approved metallodrugs is very low, in contrast to the majority of drugs available as organic compounds. The search for alternative drugs to cisplatin, carboplatin and other derivatives is highly needed due to their severe side effects including nephrotoxicity and neurotoxicity. Ruthenium, among other transition metal complexes appears to be a possible candidate for cancer therapy in the near future. The most significant rationale is ruthenium's octahedral chemistry and greater propensity to undergo redox reactions. The hypoxic environment of tumors favors the reduction of inert ruthenium (III) to active ruthenium (II) which opens new prospects for the development of novel prodrugs. Although studies suggest that ruthenium complexes penetrate well within the tumor cells and bind effectively to DNA, its binding to proteins is not very well explained. Ruthenium complexes are presently receiving great attention in the fields of biological, pharmaceutical and medicinal chemistry as anticancer agents. This review poses a comprehensive overview of the studies on competent anticancer ruthenium complexes and the role of these metal complexes in relation to their anticancer properties as well as those under clinical trials.

  15. Metalorganic Chemical Vapor Deposition of Ruthenium-Doped Diamond like Carbon Films

    NASA Technical Reports Server (NTRS)

    Sunkara, M. K.; Ueno, M.; Lian, G.; Dickey, E. C.

    2001-01-01

    We investigated metalorganic precursor deposition using a Microwave Electron Cyclotron Resonance (ECR) plasma for depositing metal-doped diamondlike carbon films. Specifically, the deposition of ruthenium doped diamondlike carbon films was investigated using the decomposition of a novel ruthenium precursor, Bis(ethylcyclopentadienyl)-ruthenium (Ru(C5H4C2H5)2). The ruthenium precursor was introduced close to the substrate stage. The substrate was independently biased using an applied RF power. Films were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Four Point Probe. The conductivity of the films deposited using ruthenium precursor showed strong dependency on the deposition parameters such as pressure. Ruthenium doped sample showed the presence of diamond crystallites with an average size of approx. 3 nm while un-doped diamondlike carbon sample showed the presence of diamond crystallites with an average size of 11 nm. TEM results showed that ruthenium was atomically dispersed within the amorphous carbon network in the films.

  16. Arene-ruthenium(II) complexes with hydrophilic P-donor ligands: versatile catalysts in aqueous media.

    PubMed

    Crochet, Pascale; Cadierno, Victorio

    2014-09-07

    In the last few years there has been increasing interest in the use of water as a reaction medium for catalysis, and therefore in designing water-soluble transition-metal catalysts. Half-sandwich (η(6)-arene)-ruthenium(ii) complexes are a versatile and well-known family of ruthenium compounds that exhibit a rich catalytic and coordination chemistry. This Perspective article focuses on the catalytic applications in aqueous media of (η(6)-arene)-ruthenium(ii) complexes containing water-soluble phosphines, and related hydrophilic P-donor ligands.

  17. meta-C-H Bromination on Purine Bases by Heterogeneous Ruthenium Catalysis.

    PubMed

    Warratz, Svenja; Burns, David J; Zhu, Cuiju; Korvorapun, Korkit; Rogge, Torben; Scholz, Julius; Jooss, Christian; Gelman, Dmitri; Ackermann, Lutz

    2017-02-01

    Methods for positionally selective remote C-H functionalizations are in high demand. Herein, we disclose the first heterogeneous ruthenium catalyst for meta-selective C-H functionalizations, which enabled remote halogenations with excellent site selectivity and ample scope. The versatile heterogeneous Ru@SiO2 catalyst was broadly applicable and could be easily recovered and reused, which set the stage for the direct fluorescent labeling of purines. In contrast to palladium, rhodium, iridium, or cobalt complexes, solely the ruthenium catalysis manifold provided access to meta-halogenated purine derivatives, illustrating the unique power of ruthenium C-H activation catalysis.

  18. Amorphous thin film ruthenium oxide as an electrode material for electrochemical capacitors

    SciTech Connect

    Jow, T.R.; Zheng, J.P.

    1995-12-31

    Ruthenium oxide thin films of an amorphous phase were successfully prepared on a titanium (Ti) substrate at temperatures below 160 C. The sol-gel process using metal alkoxide precursor in nonaqueous solvents was used to prepare these films. The preliminary results showed that a specific capacitance of 430 F/g can be achieved for amorphous ruthenium oxide electrode in sulfuric acid. Films prepared by this method are compared with the films prepared by the thermal decomposition of the aqueous ruthenium chloride solution at temperatures above 300 C. The specific capacitance, the crystalline structure, and the surface morphology of these films as a function of the preparation temperature were also discussed.

  19. Novel Ruthenium Sensitizers with a Phenothiazine Conjugated Bipyridyl Ligand for High-Efficiency Dye-Sensitized Solar Cells.

    PubMed

    She, Zhijie; Cheng, Yangyang; Zhang, Luoqiang; Li, Xiaoyu; Wu, Di; Guo, Qiang; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2015-12-23

    Two efficient ruthenium sensitizers with a phenothiazine-modified bipyridine as an ancillary ligand, coded SCZ-1 and SCZ-2, have been developed as dyes in dye-sensitized solar cells (DSSCs). Both sensitizers exhibit low-energy metal-to-ligand charge transfer (MLCT) bands centered at 539 nm with high molar extinction coefficients of 1.77 × 10(4) M(-1) cm(-1) for SCZ-1 and 1.66 × 10(4) M(-1) cm(-1) for SCZ-2, which are significantly higher than the corresponding value for the reference N719 (1.27 × 10(4) M(-1) cm(-1)), indicating that the light-harvesting capacity of ruthenium sensitizers can be reinforced by introducing phenothiazine moieties into the bipyridine ligand. Under AM 1.5G irradiation (100 mW cm(-2)), SCZ-1 and SCZ-2 sensitized DSSC devices show impressive power conversion efficiencies (PCE) up to 10.4% by using of iodide-based electrolytes, which exceeds that of N719 (9.9%) under the same conditions. Both of the open circuit voltage (VOC) and fill factor (FF) of SCZ-sensitized solar cells approximate to those of N719-sensitized cell. The relatively higher efficiencies of the SCZ-sensitized cells than that of N719-sensitized cell come from their higher short-circuit photocurrent density (JSC), which may be mainly attributed to the high absorption coefficient. The absorption spectrum and device efficiency of SCZ-1 are both quite close to those of SCZ-2, suggesting that the difference in alkyl chains on the N atom of phenothiazine is not a decisive factor in affecting the photovoltaic performance of dyes.

  20. Organometallic ruthenium(II) arene compounds with antiangiogenic activity.

    PubMed

    Nowak-Sliwinska, Patrycja; van Beijnum, Judy R; Casini, Angela; Nazarov, Alexey A; Wagnieres, Georges; van den Bergh, Hubert; Dyson, Paul J; Griffioen, Arjan W

    2011-06-09

    The antimetastatic ruthenium(II) compounds [Ru(η(6)-p-cymene)Cl(2)(PTA)] (PTA = 1,3,5-triaza-7-phosphaadamantane) (RAPTA-C) and [Ru(η(6)-toluene)Cl(2)(PTA)] (RAPTA-T), as well as their analogues [Ru(η(6)-p-cymene)Cl(2)(DAPTA)] (DAPTA = (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane)) (DAPTA-C) and [Ru(η(6)-toluene)Cl(2)(DAPTA)] (DAPTA-T), respectively, were tested in in vitro bioassays for endothelial cell function. All compounds showed low toxicity profiles and similar dose-dependent antiproliferative effects in endothelial cells at ≥100 μg/mL (∼200 μM). EC migration, measured 6 h after drug exposure, was also efficiently inhibited (ED(50) of ∼300 μg/mL, ∼500 μM, for all compounds). Since no cytostatic effect was noted, the inhibition of proliferation was considered mainly to consist of antiangiogenic activity. RAPTA-T and DAPTA-C were also tested in vivo in the chicken chorioallantoic membrane (CAM) assay and found to inhibit CAM development. Importantly, effective prevention of revascularization of the CAM after vaso-occlusive photodynamic therapy was observed. The reported ruthenium complexes show promising antimetastatic activity involving inhibition of angiogenesis and therefore are attractive agents for development of anticancer therapies based on combination of chemo- and angiostatic treatments.

  1. Committee's report on ruthenium fall-out incident

    SciTech Connect

    Borkowski, C.J.; Crawford, J.H.; Livingston, R.; Ritchie, R.H.; Rupp, A.F.; Taylor, E.H.

    1983-07-01

    Investigations of the fall-out incident of November 11 and 12, 1959, by responsible parties (Health Physics Division and Operations Division personnel) established beyond reasonable doubt that the incident had its origin in the expulsion of particles, heavily contaminated with ruthenium, which had been detached from the walls of the electric fan housing and ducts in the off-gas system associated with the brick stack. All available evidence indicates that the particles were loosened during maintenance work on the exhaust damper and the bearings of the electric fan and were carried up the stack in two bursts as particulate fall-out when this fan was put back into service. Radiographic and chemical analysis showed the activity to be almost entirely ruthenium (Ru/sup 106/) and its daughter rhodium (Rh/sup 106/) with very little, if any, strontium being present. This report summarizes the findings and sets forth the conclusions and recommendations of the Committee asked to investigate the incident.

  2. Ruthenium: A superior compensator of InP

    NASA Astrophysics Data System (ADS)

    Dadgar, A.; Stenzel, O.; Näser, A.; Zafar Iqbal, M.; Bimberg, D.; Schumann, H.

    1998-12-01

    The 4d-transition metal ruthenium presents a new dopant to fabricate thermally stable semi-insulating InP layers for both electron and hole injection. The layers are grown by low-pressure metalorganic chemical vapor deposition using tertiarybutylphosphine and trimethylindium as source materials for InP growth. Using bis(η5-2,4-dimethyl-pentadienyl)ruthenium(II) as precursor Ru doping concentrations of the order of 4×1018cm-3 are achieved, determined by means of secondary ion mass spectroscopy. The Ru diffusion coefficient in InP is determined to DRu(800 °C)⩽1×10-15 cm2/s which is four orders of magnitude smaller than for Fe. Resistivities obtained under electron and hole injection are above 6×107Ω cm and 5×108 Ω cm, respectively. In deep level transient spectroscopy measurements under electron emission and hole emission, one deep level each with concentrations around 1016 cm-3, is observed.

  3. Rotational bands in99Sr

    NASA Astrophysics Data System (ADS)

    Pfeiffer, B.; Monnand, E.; Pinston, J. A.; Münzel, J.; Möller, P.; Krumlinde, J.; Ziegert, W.; Kratz, K.-L.

    1984-02-01

    The β-decay of 59 ms99Rb has been studied at OSTIS. As is confirmed by RPA calculations with Nilsson model wave functions, the lowest energy levels in99Sr are consistent with rotational bands built on the [411 3/2], [413 5/2] and [422 3/2] Nilsson neutron configurations at 0, 423 and 1071 keV, respectively. All three bands have similar values of the inertial parameter ħ2/2θ indicating a nearly rigid rotor.

  4. Platinum-ruthenium nanotubes and platinum-ruthenium coated copper nanowires as efficient catalysts for electro-oxidation of methanol

    DOE PAGES

    Zheng, Jie; Cullen, David A.; Forest, Robert V.; ...

    2015-01-15

    The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this study, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). Finally, x-raymore » photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.« less

  5. Platinum-ruthenium nanotubes and platinum-ruthenium coated copper nanowires as efficient catalysts for electro-oxidation of methanol

    SciTech Connect

    Zheng, Jie; Cullen, David A.; Forest, Robert V.; Wittkopf, Jarrid A.; Zhuang, Zhongbin; Zheng, Whenchao; Chen, Jingguang G.; Yan, Yushan

    2015-01-15

    The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this study, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). Finally, x-ray photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.

  6. Beta decay of 99Tcm

    NASA Astrophysics Data System (ADS)

    Alburger, D. E.; Richards, P.; Ku, T. H.

    1980-02-01

    The emission of β rays from 6.02-h 99Tcm has been detected with an intermediate-image magnetic spectrometer. β-ray components with end-point energies of 434.8+/-2.6 keV (β0) to the 99Ru ground state and 346.7+/-2.0 keV (β1) to the 90-keV state were found with intensities per decay of (1.0+/-0.3) × 10-5 for β0 and (2.6+/-0.5) × 10-5 for β1. In the Kurie plot analysis the unique first-forbidden "α" shape was assumed for β0 and an allowed shape was assumed for β1. Values of f1t=9.39+/-0.11 for β0 and f0t=8.66+/-0.08 for β1 were derived. γ rays of 322, 233, and 140 keV were observed in a calibrated Ge(Li) detector with relative source intensities of I322:I233:I140=(1.13+/-0.09)×10-6:(0.95+/-0.17)×10-7:1.000. The total β-ray branching of 3.7 × 10-5 results in a negligible correction to dosage calculations in the use of 99Tcm for diagnostic nuclear medicine. RADIOACTIVITY 99Tcm: measured Eβ, Iβ, and Iγ magnetic spectrometer, Ge(Li); deduced decay scheme.

  7. 99 Tips for Safe Schools.

    ERIC Educational Resources Information Center

    Kaufer, Steve

    This pamphlet highlights 99 tips for maintaining safe schools. Areas of interest include: alarm systems and control of access, vandalism, parent education, transportation, school design, personnel training, and graffiti. The majority of the pointers deal with maintaining and implementing various forms of electronic surveillance and strategies for…

  8. Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide

    DOEpatents

    Pierantozzi, R.

    1985-04-09

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  9. Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries

    SciTech Connect

    Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

    2014-12-01

    Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

  10. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, R.

    1985-04-02

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  11. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  12. Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  13. Platinum-ruthenium-palladium alloys for use as a fuel cell catalyst

    DOEpatents

    Gorer, Alexander

    2002-01-01

    A noble metal alloy composition for a fuel cell catalyst, a ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

  14. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Corbea, Javier Jesus Concepcion; Chen, Zoufeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2016-06-07

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  15. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Concepcion Corbea, Javier Jesus; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L; Hoertz, Paul; Meyer, Thomas J

    2014-10-28

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  16. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Corbea, Javier Jesus Concepcion; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2013-09-03

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  17. Ruthenium complexes containing bis-benzimidazole derivatives as a new class of apoptosis inducers.

    PubMed

    Li, Linlin; Wong, Yum-Shing; Chen, Tianfeng; Fan, Cundong; Zheng, Wenjie

    2012-01-28

    A series of ruthenium complexes containing bis-benzimidazole derivatives have been synthesized and identified as able to target mitochondria and induce caspase-dependent apoptosis in cancer cells through superoxide overproduction.

  18. Characterization of Palladium and Ruthenium after Reaction with Tetraphenylborate and Mercury

    SciTech Connect

    Duff, M.C.

    2001-09-11

    This report documents a second series of X-ray fine structure and chemical analyses to examine the form that Pd - and, to a lesser extent, ruthenium (Ru) - takes in simulated high-level slurries containing TPB salts.

  19. Ruthenium on rutile catalyst, catalytic system, and method for aqueous phase hydrogenations

    DOEpatents

    Elliot, Douglas C.; Werpy, Todd A.; Wang, Yong; Frye, Jr., John G.

    2001-01-01

    An essentially nickel- and rhenium-free catalyst is described comprising ruthenium on a titania support where the titania is greater than 75% rutile. A catalytic system containing a nickel-free catalyst comprising ruthenium on a titania support where the titania is greater than 75% rutile, and a method using this catalyst in the hydrogenation of an organic compound in the aqueous phase is also described.

  20. 2-Nitroimidazole-ruthenium polypyridyl complex as a new conjugate for cancer treatment and visualization.

    PubMed

    Mazuryk, Olga; Maciuszek, Monika; Stochel, Grażyna; Suzenet, Franck; Brindell, Małgorzata

    2014-05-01

    A novel long-lifetime highly luminescent ruthenium polypyridyl complex containing 2-nitroimidazole moiety [Ru(dip)2(bpy-2-nitroIm)]Cl2 (dip=4,7-diphenyl-1,10-phenanthroline, bpy-2-nitroIm=4-[3-(2-nitro-1H-imidazol-1-yl)propyl]-2,2'-bipyridine) has been designed cancer treatment and imaging. The luminescence properties of the synthesized compound strongly depend on the oxygen concentration. Under oxygen-free conditions quantum yield of luminescence and the average lifetime of emission were found to be 0.034 and 1.9 μs, respectively, which is ca. three times higher in comparison to values obtained in air-equilibrated solution. The binding properties of the investigated ruthenium complex to human serum albumin have been studied and the apparent binding constant for the formation of the protein-ruthenium adduct was determined to be 1.1×10(5)M(-1). The quantum yield and the average lifetime of emission are greatly enhanced upon binding of ruthenium compound to the protein. The DNA binding studies revealed two distinguished binding modes which lead to a decrease in luminescence intensity of ruthenium complex up to 60% for [DNA]/[Ru]<2, and enhancement of emission for [DNA]/[Ru]>80. Preliminary biological studies confirmed fast and efficient accumulation of the ruthenium complex inside cells. Furthermore, the ruthenium complex was found to be relatively cytotoxic with LD50 of 12 and 13 μM for A549 and CT26 cell lines, respectively, under normoxic conditions. The retention and cellular uptake of ruthenium complex is enhanced under hypoxic conditions and its LD50 decreases to 8 μM for A549 cell line. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Electron Transfer Studies of Ruthenium(II) Complexes with Biologically Important Phenolic Acids and Tyrosine.

    PubMed

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Rajagopal, Seenivasan

    2016-03-01

    The ruthenium(II) complexes having 2,2'-bipyridine and phenanthroline derivatives are synthesized and characterized. The photophysical properties of these complexes at pH 12.5 are studied. The electron transfer reaction of biologically important phenolic acids and tyrosine are studied using absorption, emission and transient absorption spectral techniques. Semiclassical theory is applied to calculate the rate of electron transfer between ruthenium(II) complexes and biologically important phenolic acids.

  2. Stereoselective, Dual-Mode Ruthenium-Catalyzed Ring-Expansion of Alkynylcyclopropanols

    PubMed Central

    Trost, Barry M.; Xie, Jia; Maulide, Nuno

    2009-01-01

    A novel, dual-pathway ring-expansion of alkynylcyclopropanols is described. On treatment with a ruthenium catalyst, these compounds undergo highly selective enlargement to either (Z)-alkylidene cyclobutanones or β-substituted cyclopentenones. The unique ability to access the least selective double bond isomers of alkylidene cyclobutanones and the dramatic shift of reactivity observed further illustrate the particular intricacies of ruthenium catalysis when compared to other alkynophilic transition metals. PMID:19053484

  3. The synthesis, characterization, and reactivity of some alkyne, vinylidene, and butatrienylidene complexes of ruthenium

    SciTech Connect

    Lomprey, J.R.

    1993-01-01

    Cumulene complexes of ruthenium were studied in regard to their preparation, characterization, and reactivity. This work is divided into two parts: first, a study of the alkyne to vinylidene isomerization on a ruthenium (II) center, and second the study of the synthesis of metal butatrienylidene complexes. The isomeric C[sub 2]H[sub 2] complexes [Ru([eta][sup 2]-HC[triple bond]CH) (PMe[sub 2]-Ph)[sub 2] (Cp)] [BF[sub 4

  4. Photochemical generation and kinetic studies of a putative porphyrin-ruthenium(V)-oxo species

    PubMed Central

    Zhang, Rui; Vanover, Eric; Luo, Weilong; Newcomb, Martin

    2014-01-01

    Photo-disproportionation of a bis-porphyrin-diruthenium(IV) μ-oxo dimer gave a porphyrin-ruthenium(III) species and a putative poprhyrin-ruthenium(V)-oxo species that can be detected and studied in real time via laser flash photolysis methods. As determined by its spectral and kinetic behavior, the same oxo transient was also formed by photolysis of a porphyrin-ruthenium(III) N-oxide adduct. Second-order rate constants for reactions with several substrates at 22 °C were determined; representative values of rate constants were kox = 6.6 × 103 M−1 s−1 for diphenylmethanol, kox = 2.5 × 103 M−1 s−1 for styrene, and kox = 1.8 × 103 M−1 s−1 for cyclohexene. The putative porphyrin-ruthenium(V)-oxo transient reacted 5–6 orders of magnitude faster than the corresponding trans-dioxoruthenium(VI)-oxo porphyrins, and the rate constants obtained in this work were similar to those of corrole-iron(V)-oxo derivative. The high reactivity for the photochemically generated ruthenium-oxo species in comparison to other poprhyrin-metal-oxo intermediates suggests it is a true ruthenium(V)-oxo species. PMID:24770388

  5. Phosphorescent ruthenium complexes with a nitroimidazole unit that image oxygen fluctuation in tumor tissue.

    PubMed

    Son, Aoi; Kawasaki, Atsushi; Hara, Daiki; Ito, Takeo; Tanabe, Kazuhito

    2015-02-02

    Understanding oxygen fluctuation in a cancerous tumor is important for effective treatment, especially during radiotherapy. In this paper, ruthenium complexes bearing a nitroimidazole group are shown to report the oxygen status in tumor tissue directly. The nitroimidazole group was known to be accumulated in hypoxic tumor tissues. On the other hand, the ruthenium complex showed strong phosphorescence around 600 nm. The emission of ruthenium is quenched instantaneously by molecular oxygen due to energy transfer between triplet states of oxygen and ruthenium complex, but the emission is then recovered by the removal of oxygen. Thus, we could observe oxygen fluctuation in tumor tissue in a real-time manner by monitoring the phosphorescence of the ruthenium complex. The versatility of the probe is demonstrated by monitoring oxygen fluctuation in living cells and tumor tissue planted in mice. The ruthenium complex promptly penetrated plasma membrane and accumulated in cells to emit its oxygen-dependent phosphorescence. In vivo experiments revealed that the oxygen level in tumor tissue seems to fluctuate at the sub-minute timescale. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Photochemical generation and kinetic studies of a putative porphyrin-ruthenium(V)-oxo species.

    PubMed

    Zhang, Rui; Vanover, Eric; Luo, Weilong; Newcomb, Martin

    2014-06-21

    Photo-disproportionation of a bis-porphyrin-diruthenium(IV) μ-oxo dimer gave a porphyrin-ruthenium(III) species and a putative porphyrin-ruthenium(V)-oxo species that can be detected and studied in real time via laser flash photolysis methods. As determined by its spectral and kinetic behavior, the same oxo transient was also formed by photolysis of a porphyrin-ruthenium(III) N-oxide adduct. Second-order rate constants for reactions with several substrates at 22 °C were determined; representative values of rate constants were kox = 6.6 × 10(3) M(-1) s(-1) for diphenylmethanol, kox = 2.5 × 10(3) M(-1) s(-1) for styrene, and kox = 1.8 × 10(3) M(-1) s(-1) for cyclohexene. The putative porphyrin-ruthenium(V)-oxo transient reacted 5-6 orders of magnitude faster than the corresponding trans-dioxoruthenium(VI) porphyrins, and the rate constants obtained in this work were similar to those of the corrole-iron(V)-oxo derivative. The high reactivity for the photochemically generated ruthenium-oxo species in comparison to other porphyrin-metal-oxo intermediates suggests that it is a true ruthenium(V)-oxo species.

  7. A New Homogeneous Catalyst for the Dehydrogenation of Dimethylamine Borane Starting with Ruthenium(III) Acetylacetonate

    PubMed Central

    Ünel Barın, Ebru; Masjedi, Mehdi; Özkar, Saim

    2015-01-01

    The catalytic activity of ruthenium(III) acetylacetonate was investigated for the first time in the dehydrogenation of dimethylamine borane. During catalytic reaction, a new ruthenium(II) species is formed in situ from the reduction of ruthenium(III) and characterized using UV-Visible, Fourier transform infrared (FTIR), 1H NMR, and mass spectroscopy. The most likely structure suggested for the ruthenium(II) species is mer-[Ru(N2Me4)3(acac)H]. Mercury poisoning experiment indicates that the catalytic dehydrogenation of dimethylamine-borane is homogeneous catalysis. The kinetics of the catalytic dehydrogenation of dimethylamine borane starting with Ru(acac)3 were studied depending on the catalyst concentration, substrate concentration and temperature. The hydrogen generation was found to be first-order with respect to catalyst concentration and zero-order regarding the substrate concentration. Evaluation of the kinetic data provides the activation parameters for the dehydrogenation reaction: the activation energy Ea = 85 ± 2 kJ·mol−1, the enthalpy of activation ∆H# = 82 ± 2 kJ·mol−1 and the entropy of activation; ∆S# = −85 ± 5 J·mol−1·K−1. The ruthenium(II) catalyst formed from the reduction of ruthenium(III) acetylacetonate provides 1700 turnovers over 100 hours in hydrogen generation from the dehydrogenation of dimethylamine borane before deactivation at 60 °C.

  8. Corrosion Investigations of Ruthenium in Potassium Periodate Solutions Relevant for Chemical Mechanical Polishing

    NASA Astrophysics Data System (ADS)

    Cheng, Jie; Wang, Tongqing; Pan, Jinshan; Lu, Xinchun

    2016-08-01

    Ruthenium is the most promising material for the barrier layer used for the sub 14 nm technology node in integrated circuits manufacturing. Potassium periodate (KIO4)-based slurry is used in the chemical mechanical planarization (CMP) process of the barrier layer. However, the electrochemical and corrosion properties of ruthenium have not been investigated in such slurry. In this paper, the electrochemical and corrosion behaviors of ruthenium in KIO4 solutions were investigated under static conditions but at different pH values by potentiodynamic polarization and electrochemical impedance spectroscopy measurements, combined with surface chemical analysis using auger electron spectroscopy. Moreover, to study wear enhanced corrosion during CMP, tribocorrosion experiments were carried out to monitor the current density changes during and after mechanical scratching. The results show that at pH 6, ruthenium forms a relatively thick and heterogeneous surface film composed of RuO2·2H2O/RuO3, showing a high corrosion resistance and it exhibits a quick repassivation after mechanical scratching. At pH 4, ruthenium shows a passivation behavior with formation of a uniform and conductive oxide like RuO2·2H2O. It should be noted that there is a possible formation of RuO4 toxic gas under this condition, which should be avoided in the actual production. However, at pH 11, ruthenium exhibits no considerable passivity and the corrosion proceeds uniformly.

  9. Anticancer Activity and Modes of Action of (arene) ruthenium(II) Complexes Coordinated to C-, N-, and O-ligands.

    PubMed

    Biersack, Bernhard

    2016-01-01

    An overview of anticancer active (arene)ruthenium(II) complexes coordinated to period 2 element-based ligand systems, i.e., carbon-, nitrogen-, and oxygen-coordinated ligands, is provided in this mini-review. A bridge is forged from the large group of anticancer active ruthenium compounds with monodentate and chelating nitrogen ligands via complexes of O,O-chelating ligands to organometallic ruthenium derivatives coordinated to carbon. (Arene)ruthenium(II) complexes with reduced side-effects and enhanced efficacy against cancer are highlighted. Pertinent literature is covered up to 2014.

  10. A selective, long-lived deep-red emissive ruthenium(II) polypyridine complexes for the detection of BSA.

    PubMed

    Babu, Eththilu; Muthu Mareeswaran, Paulpandian; Singaravadivel, Subramanian; Bhuvaneswari, Jayaraman; Rajagopal, Seenivasan

    2014-09-15

    A selective, label free luminescence sensor for bovine serum albumin (BSA) is investigated using ruthenium(II) complexes over the other proteins. Interaction between BSA and ruthenium(II) complexes has been studied using absorption, emission, excited state lifetime and circular dichroism (CD) spectral techniques. The luminescence intensity of ruthenium(II) complexes (I and II), has enhanced at 602 and 613 nm with a large hypsochromic shift of 18 and 5 nm respectively upon addition of BSA. The mode of binding of ruthenium(II) complexes with BSA has analyzed using computational docking studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A ruthenium water oxidation catalyst containing a bipyridine glycoluril ligand.

    PubMed

    Mane, Vishwanath S; Kumbhar, Avinash S; Thummel, Randolph P

    2017-10-03

    A mononuclear ruthenium complex [Ru(tpy)(bpg)H2O](2+) bearing a bipyridine glycoluril where bpg = 4b,5,7,7a-tetrahydro-4b,7a-nepiminomethanoimino-6H-imidazo[4,5-f][1,10]phenanthro-line-6,13-dione acts as a robust water oxidation catalyst (WOC) at pH = 1 using Ce(iv) as a sacrificial oxidant. The turn over number (TON) for water oxidation is found to be ∼5 times higher than the parent complex [Ru(tpy)(bpy)H2O](2+) where tpy = 2,2':6',2''-terpyridine; bpy = 2,2'-bipyridine. The presence of intermolecular H-bonding groups and the electronic effect of the functionalized bipyridine ligand may play a significant role in water oxidation.

  12. Catalytic determination of ultratrace amounts of ruthenium with oscillopolarography monitoring

    SciTech Connect

    Jiang Zhi-Liang; Wang Li-Sheng )

    1993-09-01

    The single sweep oscillopolarographic behaviour of Rhodamine B in sulphuric acid medium was investigated. A novel, sensitive and selective catalytic method with oscillopolarography monitoring for the determination of ultratrace amounts of ruthenium was described, based on the catalytic effect of Ru(III) on the slow redox reaction occurring between Rhodamine B and potassium periodate in sulphuric acid medium at 25[degrees]C. Single sweep oscillopolarography is used to monitor the changes in concentration of Rhodamine B by means of the second derivative wave [minus]0.55 V vs. SCE. The determination range from 8.2x10[sup [minus]10] to 2.5x10[sup [minus]8] M Ru was obtained by the initial rate procedure. Influence of 30 foreign ions was considered. Ru in ore samples was analysed by this method, with satisfactory results.

  13. Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation

    SciTech Connect

    Joo, Sang Hoon; Park, Jeong Y.; Renzas, J. Russell; Butcher, Derek R.; Huang, Wenyu; Somorjai, Gabor A.

    2010-04-04

    Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac){sub 3} precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O{sub 2}) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm Ru NP catalyst shows 8-fold higher activity than the 2 nm catalysts. The results gained from this study will provide the scientific basis for future design of Ru-based oxidation catalysts.

  14. Platinum adlayered ruthenium nanoparticles, method for preparing, and uses thereof

    DOEpatents

    Tong, YuYe; Du, Bingchen

    2015-08-11

    A superior, industrially scalable one-pot ethylene glycol-based wet chemistry method to prepare platinum-adlayered ruthenium nanoparticles has been developed that offers an exquisite control of the platinum packing density of the adlayers and effectively prevents sintering of the nanoparticles during the deposition process. The wet chemistry based method for the controlled deposition of submonolayer platinum is advantageous in terms of processing and maximizing the use of platinum and can, in principle, be scaled up straightforwardly to an industrial level. The reactivity of the Pt(31)-Ru sample was about 150% higher than that of the industrial benchmark PtRu (1:1) alloy sample but with 3.5 times less platinum loading. Using the Pt(31)-Ru nanoparticles would lower the electrode material cost compared to using the industrial benchmark alloy nanoparticles for direct methanol fuel cell applications.

  15. Synthesis, characterization, and anticancer activity of ruthenium-pyrazole complexes.

    PubMed

    David, Solene; Perkins, Richard S; Fronczek, Frank R; Kasiri, Sahba; Mandal, Subhrangsu S; Srivastava, Radhey S

    2012-06-01

    A series of new water soluble Ru(III) pyrazole complexes mer-[RuCl(3)(DMSO-S)(pyz)(2)] 1, mer-[RuCl(3)(DMSO-S)(DMSO-O)(pyz)] 2, mer-[RuCl(3)(bpy)(dmpyz)] 3, and mer-[RuCl(3)(DMSO-S)(dmpyz)(2)] 4 (pyz=pyrazole; dmpyz=3,5-dimethylpyrazole, bpy=2,2'-bipyridine) have been synthesized and characterized by use of a combination of spectroscopy (IR and UV-visible), X-ray diffraction, and cyclic voltammetry. The molecular X-ray structure of all reported compounds (1-4) revealed distorted octahedral coordination around ruthenium. The cytotoxicity assay on human breast cancer cells (MCF7) demonstrated that compounds 1 and 4 affect cell viability, whereas compounds 2 and 3 do not show appreciable activity. The IC(50) values for 1 and 4 lie within the range of 71-32μM in MCF7 cells.

  16. Similar Biological Activities of Two Isostructural Ruthenium and Osmium Complexes

    SciTech Connect

    Maksimoska,J.; Williams, D.; Atilla-Gokcumen, G.; Smalley, K.; Carroll, P.; Webster, R.; Filippakopoulos, P.; Knapp, S.; Herlyn, M.; Meggers, E.

    2008-01-01

    In this study, we probe and verify the concept of designing unreactive bioactive metal complexes, in which the metal possesses a purely structural function, by investigating the consequences of replacing ruthenium in a bioactive half-sandwich kinase inhibitor scaffold by its heavier congener osmium. The two isostructural complexes are compared with respect to their anticancer properties in 1205?Lu melanoma cells, activation of the Wnt signaling pathway, IC50 values against the protein kinases GSK-3? and Pim-1, and binding modes to the protein kinase Pim-1 by protein crystallography. It was found that the two congeners display almost indistinguishable biological activities, which can be explained by their nearly identical three-dimensional structures and their identical mode of action as protein kinase inhibitors. This is a unique example in which the replacement of a metal in an anticancer scaffold by its heavier homologue does not alter its biological activity.

  17. Modulating the Anticancer Activity of Ruthenium(II)-Arene Complexes.

    PubMed

    Clavel, Catherine M; Păunescu, Emilia; Nowak-Sliwinska, Patrycja; Griffioen, Arjan W; Scopelliti, Rosario; Dyson, Paul J

    2015-04-23

    Following the identification of [Ru(η(6)-p-cymene)Cl2(1H,1H,2H,2H-perfluorodecyl-3-(pyridin-3-yl)propanoate)], a ruthenium(II)-arene complex with a perfluoroalkyl-modified ligand that displays remarkable in vitro cancer cell selectivity, a series of structurally related compounds were designed. In the new derivatives, the p-cymene ring and/or the chloride ligands are substituted by other ligands to modulate the steric bulk or aquation kinetics. The new compounds were evaluated in both in vitro (cytotoxicity and migration assays) and in vivo (chicken chorioallantoic membrane) models and were found to exhibit potent antivascular effects.

  18. Thermal conductivity of ruthenium aluminide (RuAl)

    SciTech Connect

    Anderson, S.A.; Lang, C.I.

    1998-01-06

    Ruthenium aluminide (RuAl) is an intermetallic compound which exhibits strength at high temperatures together with attractive room temperature toughness. This combination of properties makes it a promising material for use at higher temperatures than currently possible with conventional titanium and nickel based alloys. Although high temperature applications will demand a knowledge and understanding of the thermal properties of RuAl, no such information is available in the scientific literature. In this paper, measurements of the thermal conductivity of RuAl are reported for the first time. Although the electrical properties of RuAl have previously been investigated, further electrical resistivity measurements have been made, using the same samples used to measure thermal conductivity. This allows a direct, meaningful comparison of electrical and thermal conductivity data, offering insights into the thermal transport mechanisms in RuAl. Microstructure is shown to have a significant influence on thermal and electrical properties.

  19. Catalytic determination of ultratrace amounts of ruthenium with oscillopolarographic detection.

    PubMed

    Zhi-Liang, J

    1991-06-01

    The oscillopolarographic behaviour of Methyl Red in sodium hydroxide medium has been studied, and the results show that the wave at -0.79 V is an irreversible two-electron adsorption wave. A very sensitive and selective catalytic reaction-oscillopolarographic method for the determination of Ru down to 3 ng/l. is described, based on the Ru(III)-catalysed redox reaction of Methyl Red and potassium periodate in hydrochloric acid medium. Potassium thiocyanate is used to quench the reaction and the oscillopolarography is then performed with sodium hydroxide as the supporting electrolyte. The influence of 41 foreign ions has been examined. Ruthenium in ore samples has been determined by the method, with satisfactory results.

  20. 29 CFR 99.310 - Financial statements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Financial statements. 99.310 Section 99.310 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditees § 99... have separate audits in accordance with § 99.500(a) and prepare separate financial statements. (b...

  1. Sol-gel synthesis of hydrous ruthenium oxide nanonetworks from 1,2-epoxides

    SciTech Connect

    Walker, Jeremy; Bruce King, R.; Tannenbaum, Rina

    2007-08-15

    Hydrous ruthenium oxide (RuO{sub 2}.xH{sub 2}O) xerogels were synthesized through the addition of a 1,2-epoxide, propylene oxide, to commercial hydrated ruthenium chloride, 'RuCl{sub 3}.xH{sub 2}O,' in ethanol. After a blue-black monolithic gel formed in 4 h, the samples were allowed to age for 24 h and were dried in ambient conditions. The dried samples were then characterized by XPS, XRD, DTA and TGA. XPS showed the Ru(3d{sub 5/2}) peak at a binding energy of 281.7 eV, corresponding to that of hydrous ruthenium oxide. XRD data revealed the synthesized material as amorphous. Heating the sample in inert atmospheres caused the complete reduction of the oxide to the zero-valent state, whereas heating the sample in air resulted in both crystalline anhydrous RuO{sub 2} and zero-valent ruthenium, depending on the method of heating. DTA traces showed an endotherm ending at 150 deg. C, corresponding to the loss of coordinated water, as well as two higher temperature crystallization exotherms when the sample was heated in both inert and oxygen-rich atmospheres. TGA runs also confirmed the complete reduction of the hydrous oxide when heated in nitrogen below 270 deg. C and the formation of anhydrous ruthenium oxide when heated in air, confirming the XRD results. - Graphical abstract: Heating of hydrous ruthenium oxide, RuO{sub 2}.xH{sub 2}O, under an inert atmosphere, results in its complete reduction to the zero-valent state, whereas heating it in air results in both crystalline anhydrous RuO{sub 2} and zero-valent ruthenium, depending on the method of heating.

  2. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    PubMed Central

    Li, H.F.; Zhou, F.Y.; Li, L.; Zheng, Y.F.

    2016-01-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co–Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10−6 cm3·g−1–1.29 × 10−6 cm3·g−1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10−6 cm3·g−1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10−6 cm3·g−1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10−6 cm3·g−1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments. PMID:27090955

  3. Structural basis and anticancer properties of ruthenium-based drug complexed with human serum albumin.

    PubMed

    Zhang, Yao; Ho, Andy; Yue, Jiping; Kong, Linlin; Zhou, Zuping; Wu, Xiaoyang; Yang, Feng; Liang, Hong

    2014-10-30

    Ruthenium-based anticancer complexes have become increasingly popular for study over the last two decades. Although ruthenium complexes are currently being investigated in clinical trials, there are still some difficulties with their delivery and associated side effects. Human serum albumin (HSA)-based delivery systems are promising for improving anticancer drug targeting and reducing negative side effects. However, there have been few studies regarding the HSA delivery system for metal-based anticancer compounds and no mention of its structural mechanism. Therefore, we studied the structure and anticancer properties of the ruthenium-based compound [RuCl5(ind)](2-) in complex with HSA. The structure revealed that [RuCl5(ind)](2-) has two binding sites in HSA. In the IB subdomain, [RuCl5(ind)](2-) binds to a new sub-site by coordinating with His-146. In the IIA subdomain, ruthenium (III) of [RuCl5(ind)](2-) binds to the hydrophobic cavity and forms coordination bonds by replacing chlorine atoms with the His-242 and Lys-199 residues of HSA. Interestingly, [RuCl5(ind)](2-), together with HSA, can enhance cytotoxicity by two to five times in cancer cells but has no effect on normal cells in vitro. Compared with unbound drug, the HSA-[RuCl5(ind)](2-) complex promotes MGC-803 cell apoptosis and also has a stronger capacity for cell cycle arrest at the G2 phase in MGC-803. In conclusion, this study will guide the rational design and development of ruthenium-containing or ruthenium-centered drugs and an HSA delivery system for ruthenium-based drugs.

  4. Development of a stable cobalt-ruthenium Fisher-Tropsch catalyst. Final report

    SciTech Connect

    Frame, R.R.; Gala, H.B.

    1995-02-01

    The reverse micelle catalyst preparation method has been used to prepare catalysts on four supports: magnesium oxide, carbon, alumina- titania and steamed Y zeolite. These catalysts were not as active as a reference catalyst prepared during previous contracts to Union Carbide Corp. This catalyst was supported on steamed Y zerolite support and was impregnated by a pore-filling method using a nonaqueous solvent. Additional catalysts were prepared via pore- filling impregnation of steamed Y zeolites. These catalysts had levels of cobalt two to three and a half times as high as the original Union Carbide catalyst. On a catalyst volume basis they were much more active than the previous catalyst; on an atom by atom basis the cobalt was about of the same activity, i.e., the high cobalt catalysts` cobalt atoms were not extensively covered over and deactivated by other cobalt atoms. The new, high activity, Y zerolite catalysts were not as stable as the earlier Union Carbide catalyst. However, stability enhancement of these catalysts should be possible, for instance, through adjustment of the quantity and/or type of trace metals present. A primary objective of this work was determination whether small amounts of ruthenium could enhance the activity of the cobalt F-T catalyst. The reverse micelle catalysts were not activated by ruthenium, indeed scanning transmission electronic microscopy (STEM) analysis provided some evidence that ruthenium was not present in the cobalt crystallites. Ruthenium did not seem to activate the high cobalt Y zeolite catalyst either, but additional experiments with Y zeolite-supported catalysts are required. Should ruthenium prove not to be an effective promoter under the simple catalyst activation procedure used in this work, more complex activation procedures have been reported which are claimed to enhance the cobalt/ruthenium interaction and result in activity promotion by ruthenium.

  5. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

    PubMed

    Li, H F; Zhou, F Y; Li, L; Zheng, Y F

    2016-04-19

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments.

  6. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    NASA Astrophysics Data System (ADS)

    Li, H. F.; Zhou, F. Y.; Li, L.; Zheng, Y. F.

    2016-04-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co–Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10‑6 cm3·g‑1–1.29 × 10‑6 cm3·g‑1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10‑6 cm3·g‑1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10‑6 cm3·g‑1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10‑6 cm3·g‑1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments.

  7. STS-99: Post Flight Presentation

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Live footage shows the crewmembers of STS-99, Commander Kevin R. Kregel, Pilot Dominic L. Pudwill Gorie, and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri, and Gerhard P.J. Thiele, arriving at Kennedy Space Center (KSC) in the T-38 aircraft. Crewmembers are seen speaking to the welcoming crowd at KSC, suiting-up, walking out to the Astro-van, being strapped in the shuttle, and performing various activities while in orbit. Scenes include the astronaut training process, main engine ignition, liftoff, solid rocket booster separation, mast deployment and retraction, and the changing of the mapping tapes. Footage also includes the crewmembers sleeping, eating, exercising, dancing and having fun in zero gravity. The High Definition Television Camera (HDTV) picks up images from the Earth. These images includes Bolivia, Paraguay, Brazil, Bahamas, Mauritania, Saudi Arabia, Mount Fuji, Tokyo Bay, Southern Russia, the Black Sea, Equador, Northern Peru, the Mediterranean Sea, Malta, Sicily and Italy. The crewmembers of STS-99 each took a turn to narrate the scenes and events as they occur.

  8. STS-99: Post Flight Presentation

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Live footage shows the crewmembers of STS-99, Commander Kevin R. Kregel, Pilot Dominic L. Pudwill Gorie, and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri, and Gerhard P.J. Thiele, arriving at Kennedy Space Center (KSC) in the T-38 aircraft. Crewmembers are seen speaking to the welcoming crowd at KSC, suiting-up, walking out to the Astro-van, being strapped in the shuttle, and performing various activities while in orbit. Scenes include the astronaut training process, main engine ignition, liftoff, solid rocket booster separation, mast deployment and retraction, and the changing of the mapping tapes. Footage also includes the crewmembers sleeping, eating, exercising, dancing and having fun in zero gravity. The High Definition Television Camera (HDTV) picks up images from the Earth. These images includes Bolivia, Paraguay, Brazil, Bahamas, Mauritania, Saudi Arabia, Mount Fuji, Tokyo Bay, Southern Russia, the Black Sea, Equador, Northern Peru, the Mediterranean Sea, Malta, Sicily and Italy. The crewmembers of STS-99 each took a turn to narrate the scenes and events as they occur.

  9. A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides

    EPA Science Inventory

    One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this...

  10. Syntheses and Characterization of Ruthenium(II) Tetrakis(pyridine)complexes: An Advanced Coordination Chemistry Experiment or Mini-Project

    ERIC Educational Resources Information Center

    Coe, Benjamin J.

    2004-01-01

    An experiment for third-year undergraduate a student is designed which provides synthetic experience and qualitative interpretation of the spectroscopic properties of the ruthenium complexes. It involves the syntheses and characterization of several coordination complexes of ruthenium, the element found directly beneath iron in the middle of the…

  11. A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides

    EPA Science Inventory

    One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this...

  12. Syntheses and Characterization of Ruthenium(II) Tetrakis(pyridine)complexes: An Advanced Coordination Chemistry Experiment or Mini-Project

    ERIC Educational Resources Information Center

    Coe, Benjamin J.

    2004-01-01

    An experiment for third-year undergraduate a student is designed which provides synthetic experience and qualitative interpretation of the spectroscopic properties of the ruthenium complexes. It involves the syntheses and characterization of several coordination complexes of ruthenium, the element found directly beneath iron in the middle of the…

  13. Directional photoinduced electron transfer in paraquat silicate thin films containing entrapped ruthenium(II)-tris(bathophenanthroline-disulfonate).

    PubMed

    Trammell, Scott A; Tsoi, Stanislav; Martin, Brett; Melde, Brian J; Moore, Martin M; Dressick, Walter J

    2011-10-28

    We have demonstrated directional photoinduced electron transfer in paraquat silicate thin films containing entrapped ruthenium(II)-tris(bathophenanthroline-disulfonate (RuBPS). The films were made by electrochemically-induced hydrolysis of a silane analogue of paraquat with ruthenium(II)-tris(bathophenanthroline-disulfonate as its ion pair.

  14. Sol gel synthesis of hydrous ruthenium oxide nanonetworks from 1,2-epoxides

    NASA Astrophysics Data System (ADS)

    Walker, Jeremy; Bruce King, R.; Tannenbaum, Rina

    2007-08-01

    Hydrous ruthenium oxide (RuO 2· xH 2O) xerogels were synthesized through the addition of a 1,2-epoxide, propylene oxide, to commercial hydrated ruthenium chloride, "RuCl 3· xH 2O," in ethanol. After a blue-black monolithic gel formed in 4 h, the samples were allowed to age for 24 h and were dried in ambient conditions. The dried samples were then characterized by XPS, XRD, DTA and TGA. XPS showed the Ru(3 d5/2) peak at a binding energy of 281.7 eV, corresponding to that of hydrous ruthenium oxide. XRD data revealed the synthesized material as amorphous. Heating the sample in inert atmospheres caused the complete reduction of the oxide to the zero-valent state, whereas heating the sample in air resulted in both crystalline anhydrous RuO 2 and zero-valent ruthenium, depending on the method of heating. DTA traces showed an endotherm ending at 150 °C, corresponding to the loss of coordinated water, as well as two higher temperature crystallization exotherms when the sample was heated in both inert and oxygen-rich atmospheres. TGA runs also confirmed the complete reduction of the hydrous oxide when heated in nitrogen below 270 °C and the formation of anhydrous ruthenium oxide when heated in air, confirming the XRD results.

  15. Metal-metal interactions in linear tri-, penta-, hepta-, and nona-nuclear ruthenium string complexes.

    PubMed

    Niskanen, Mika; Hirva, Pipsa; Haukka, Matti

    2012-05-01

    Density functional theory (DFT) methodology was used to examine the structural properties of linear metal string complexes: [Ru(3)(dpa)(4)X(2)] (X = Cl(-), CN(-), NCS(-), dpa = dipyridylamine(-)), [Ru(5)(tpda)(4)Cl(2)], and hypothetical, not yet synthesized complexes [Ru(7)(tpta)(4)Cl(2)] and [Ru(9)(ppta)(4)Cl(2)] (tpda = tri-α-pyridyldiamine(2-), tpta = tetra-α-pyridyltriamine(3-), ppta = penta-α-pyridyltetraamine(4-)). Our specific focus was on the two longest structures and on comparison of the string complexes and unsupported ruthenium backboned chain complexes, which have weaker ruthenium-ruthenium interactions. The electronic structures were studied with the aid of visualized frontier molecular orbitals, and Bader's quantum theory of atoms in molecules (QTAIM) was used to study the interactions between ruthenium atoms. The electron density was found to be highest and distributed most evenly between the ruthenium atoms in the hypothetical [Ru(7)(tpta)(4)Cl(2)] and [Ru(9)(ppta)(4)Cl(2)] string complexes.

  16. Transient Spectroscopic Characterization of the Genesis of a Ruthenium Complex Catalyst Supported on Zeolite Y

    SciTech Connect

    Ogino, Isao; Gates, Bruce C.

    2010-01-12

    A mononuclear ruthenium complex anchored to dealuminated zeolite HY, Ru(acac)(C{sub 2}H{sub 4}){sup 2+} (acac = acetylacetonate, C{sub 5}H{sub 7}O{sup 2}{sup -}), was characterized in flow reactors by transient infrared (IR) spectroscopy and Ru K edge X-ray absorption spectroscopy. The combined results show how the supported complex was converted into a form that catalyzes ethene conversion to butene. The formation of these species resulted from the removal of acac ligands from the ruthenium (as shown by IR and extended X-ray absorption fine structure (EXAFS) spectra) and the simultaneous decrease in the symmetry of the ruthenium complex, with the ruthenium remaining mononuclear and its oxidation state remaining essentially unchanged (as shown by EXAFS and X-ray absorption near-edge structure spectra). The removal of anionic acac ligands from the ruthenium was evidently compensated by the bonding of other anionic ligands, such as hydride from H2 in the feed stream, to form species suggested to be Ru(H)(C{sub 2}H{sub 4}){sub 2}{sup +}, which is coordinatively unsaturated and inferred to react with ethene, leading to the observed formation of butene in a catalytic process.

  17. Use of Ruthenium Photoreduction Techniques to Study Electron Transfer in Cytochrome Oxidase

    PubMed Central

    Durham, Bill; Millett, Francis

    2009-01-01

    Ruthenium photoreduction methods are described to study electron transfer from cytochrome c to cytochrome c oxidase, and within cytochrome oxidase. Methods are described to prepare a ruthenium cytochrome c derivative, Ru-39-Cc, by labeling the single sufhydryl group on horse K39C with (4-bromomethyl-4′methylbipyridine) (bis-bipyridine)ruthenium(II). The ruthenium complex attached to Cys-39 on the opposite side of the heme crevice does not interfere with the interaction with cytochrome oxidase. Laser flash photolysis of a 1:1 complex between Ru-39-Cc and bovine cytochrome oxidase results in photoreduction of heme c within 1 μs, followed by electron transfer from heme c to CuA in cytochrome oxidase with a rate constant of 60,000 s−1 and from CuA to heme a with a rate constant of 20,000 s−1. A new ruthenium dimer, Ru2Z, has been developed to reduce CuA within 1 μs with a yield of 60%, followed by electron transfer from CuA to heme a and then to the heme a3/CuB binuclear center. Methods are described to measure the single-electron reduction of each of the intermediates involved in reduction of oxygen to water by cytochrome oxidase, including Pm, F, OH, and E. PMID:19348907

  18. Band Offsets of a Ruthenium Gate on Ultrathin High-k Oxide Films on Silicon

    SciTech Connect

    Rangan, S.; Bersch, W; Bartynski, R; Garfunkel, E; Vescovo, E

    2009-01-01

    Valence-band and conduction-band edges of ultrathin oxides and their shifts upon sequential metallization with ruthenium have been measured using synchrotron-radiation-excited x-ray, ultraviolet, and inverse photoemissions. From these techniques, the offsets between the valence-band and conduction-band edges of the oxides, and the ruthenium metal gate Fermi edge have been directly measured. In addition the core levels of the oxides and the ruthenium have been characterized. Upon deposition, Ru remains metallic and no chemical alteration of the underlying oxide gates, or interfacial SiO{sub 2} in the case of the high-? thin films, can be detected. However a clear shift of the band edges is measured for all samples due to the creation of an interface dipole at the ruthenium-oxide interface. Using the energy gap, the electron affinity of the oxides, and the ruthenium work function that have been directly measured on these samples, the experimental band offsets are compared to those predicted by the induced gap states model.

  19. Ligand Engineering for the Efficient Dye-Sensitized Solar Cells with Ruthenium Sensitizers and Cobalt Electrolytes.

    PubMed

    Aghazada, Sadig; Gao, Peng; Yella, Aswani; Marotta, Gabriele; Moehl, Thomas; Teuscher, Joël; Moser, Jacques-E; De Angelis, Filippo; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2016-07-05

    Over the past 20 years, ruthenium(II)-based dyes have played a pivotal role in turning dye-sensitized solar cells (DSCs) into a mature technology for the third generation of photovoltaics. However, the classic I3(-)/I(-) redox couple limits the performance and application of this technique. Simply replacing the iodine-based redox couple by new types like cobalt(3+/2+) complexes was not successful because of the poor compatibility between the ruthenium(II) sensitizer and the cobalt redox species. To address this problem and achieve higher power conversion efficiencies (PCEs), we introduce here six new cyclometalated ruthenium(II)-based dyes developed through ligand engineering. We tested DSCs employing these ruthenium(II) complexes and achieved PCEs of up to 9.4% using cobalt(3+/2+)-based electrolytes, which is the record efficiency to date featuring a ruthenium-based dye. In view of the complicated liquid DSC system, the disagreement found between different characterizations enlightens us about the importance of the sensitizer loading on TiO2, which is a subtle but equally important factor in the electronic properties of the sensitizers.

  20. Quantitative study of ruthenium cross-over in direct methanol fuel cells during early operation hours

    NASA Astrophysics Data System (ADS)

    Schoekel, A.; Melke, J.; Bruns, M.; Wippermann, K.; Kuppler, F.; Roth, C.

    2016-01-01

    In direct methanol fuel cells (DMFC), ruthenium cross-over is an important degradation phenomenon. The loss of ruthenium from the anode, its transport through the membrane and its deposition onto the cathode are detrimental to the fuel cell performance and limit the fuel cell's lifetime. Here we present a quantitative study on the fraction of ruthenium being transferred from the anode to the cathode during early operation hours (0-100 h) of a DMFC. Already during fabrication of the MEA ruthenium is transferred to the cathode. In our pristine MEAs about 0.024 wt% Ru could be found in the cathode catalyst. The cell potential during operation seems to have only a minor influence on the dissolution process. In contrast, the operation time appears to be much more important. Our data hint at two dissolution processes: a fast process dominating the first hours of operation and a slower process, which is responsible for the ongoing ruthenium transfer during the fuel cell lifetime. After 2 h held at open circuit conditions the Ru content of the cathode side was 10 times higher than in the pristine MEA. In contrast, the slower process increased that amount only by a factor of two over the course of another 100 h.

  1. The inhibition of mitochondrial calcium transport by lanthanides and Ruthenium Red

    PubMed Central

    Reed, Ken C.; Bygrave, Fyfe L.

    1974-01-01

    An EGTA (ethanedioxybis(ethylamine)tetra-acetic acid)-quench technique was developed for measuring initial rates of 45Ca2+ transport by rat liver mitochondria. This method was used in conjunction with studies of Ca2+-stimulated respiration to examine the mechanisms of inhibition of Ca2+ transport by the lanthanides and Ruthenium Red. Ruthenium Red inhibits Ca2+ transport non-competitively with Ki 3×10−8m; there are 0.08nmol of carrier-specific binding sites/mg of protein. The inhibition by La3+ is competitive (Ki=2×10−8m); the concentration of lanthanide-sensitive sites is less than 0.001nmol/mg of protein. A further difference between their modes of action is that lanthanide inhibition diminishes with time whereas that by Ruthenium Red does not. Binding studies showed that both classes of inhibitor bind to a relatively large number of external sites (probably identical with the `low-affinity' Ca2+-binding sites). La3+ competes with Ruthenium Red for most of these sites, but a small fraction of the bound Ruthenium Red (less than 2nmol/mg of protein) is not displaced by La3+. The results are discussed briefly in relation to possible models for a Ca2+ carrier. PMID:4375957

  2. The Use of Specific Antibodies to Demonstrate the Glycocalyx and Spatial Relationships of a K99-, F41- Enterotoxigenic Strain of Escherichia coli Colonizing the Ileum of Colostrum-deprived Calves

    PubMed Central

    Chan, R.; Lian, C.J.; Costerton, J.W.; Acres, S.D.

    1983-01-01

    Electron microscopy was used to study the interaction between the glycocalyx of enterotoxigenic Escherichia coli strain 210 (09:K30+;K99-;F41-:H-) and the glycocalyx of epithelial cells in then ileum of experimentally infected newborn colostrum-deprived calves. Fixation of tissues in anti-K30 antibody and ruthenium red was used to stabilize the bacterial glycocalyx so that the spatial relationship between the bacteria and the intestinal epithelial cells could be characterized. When strain 210 was grown in vitro and reacted with anti-K30 antibody prior to staining with ruthenium red, the extensive glycocalyx could be clearly visualized surrounding the bacterial cells. By negative staining, an unidentified pilus was also seen. Sections of ileum from infected calves, which were not fixed in antibody nor stained with ruthenium red, revealed attached bacteria which were surrounded by an electron-translucent zone and no visible bacterial glycocalyx. When ruthenium red staining was used, the bacterial glycocalyx partially collapsed during the dehydration steps of fixation, but could be seen as either a fibrous capsule or an electron-dense accretion on the bacterial cell surface. When ileal tissue was reacted for one hour in anti-K30 antibody before staining with ruthenium red, the bacterial glycocalyx was seen as a discrete electron-dense structure up to 1.0µm thick which was in intimate contact with the glycocalyx of the epithelial cells. The importance of the bacterial exopolysaccharide to microcolony formation on the villi could be clearly visualized. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7. PMID:6349756

  3. Biological processing of dinuclear ruthenium complexes in eukaryotic cells.

    PubMed

    Li, Xin; Heimann, Kirsten; Dinh, Xuyen Thi; Keene, F Richard; Collins, J Grant

    2016-10-20

    The biological processing - mechanism of cellular uptake, effects on the cytoplasmic and mitochondrial membranes, intracellular sites of localisation and induction of reactive oxygen species - of two dinuclear polypyridylruthenium(ii) complexes has been examined in three eukaryotic cells lines. Flow cytometry was used to determine the uptake of [{Ru(phen)2}2{μ-bb12}](4+) (Rubb12) and [Ru(phen)2(μ-bb7)Ru(tpy)Cl](3+) {Rubb7-Cl, where phen = 1,10-phenanthroline, tpy = 2,2':6',2''-terpyridine and bbn = bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane} in baby hamster kidney (BHK), human embryonic kidney (HEK-293) and liver carcinoma (HepG2) cell lines. The results demonstrated that the major uptake mechanism for Rubb12 and Rubb7-Cl was active transport, although with a significant contribution from carrier-assisted diffusion for Rubb12 and passive diffusion for Rubb7-Cl. Flow cytometry coupled with Annexin V/TO-PRO-3 double-staining was used to compare cell death by membrane damage or apoptosis. Rubb12 induced significant direct membrane damage, particularly with HepG2 cells, while Rubb7-Cl caused considerably less membrane damage but induced greater levels of apoptosis. Confocal microscopy, coupled with JC-1 assays, demonstrated that Rubb12 depolarises the mitochondrial membrane, whereas Rubb7-Cl had a much smaller affect. Cellular localisation experiments indicated that Rubb12 did not accumulate in the mitochondria, whereas significant mitochondrial accumulation was observed for Rubb7-Cl. The effect of Rubb12 and Rubb7-Cl on intracellular superoxide dismutase activity showed that the ruthenium complexes could induce cell death via a reactive oxygen species-mediated pathway. The results of this study demonstrate that Rubb12 predominantly kills eukaryotic cells by damaging the cytoplasmic membrane. As this dinuclear ruthenium complex has been previously shown to exhibit greater toxicity towards bacteria than eukaryotic cells, the results of the present study suggest that

  4. 29 CFR 99.320 - Report submission.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Report submission. 99.320 Section 99.320 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditees § 99...). (ix) The Catalog of Federal Domestic Assistance (CFDA) number for each Federal program, as...

  5. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  6. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  7. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  8. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  9. 49 CFR 229.99 - Safety hangers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Safety hangers. 229.99 Section 229.99..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Internal Combustion Equipment § 229.99 Safety hangers. Drive shafts shall have safety hangers....

  10. 45 CFR 99.27 - Official transcript.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Official transcript. 99.27 Section 99.27 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND Hearing Procedures § 99.27 Official transcript. The Department...

  11. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Evidence. 99.25 Section 99.25 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally...

  12. 45 CFR 99.24 - Evidentiary purpose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Evidentiary purpose. 99.24 Section 99.24 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND Hearing Procedures § 99.24 Evidentiary purpose. The purpose of...

  13. 45 CFR 99.13 - Place.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Place. 99.13 Section 99.13 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND Preliminary Matters-Notice and Parties § 99.13 Place. The hearing shall be held in the...

  14. 45 CFR 99.31 - Posthearing briefs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Posthearing briefs. 99.31 Section 99.31 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND Posthearing Procedures, Decisions § 99.31 Posthearing briefs. The...

  15. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot...

  16. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot...

  17. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot...

  18. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot...

  19. 14 CFR 99.9 - Radio requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Radio requirements. 99.9 Section 99.9... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.9 Radio requirements. (a) A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot...

  20. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in a...

  1. Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

    PubMed

    Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

    2015-01-01

    This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

  2. 45 CFR 99.2 - Presiding officer.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Presiding officer. 99.2 Section 99.2 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND General § 99.2 Presiding officer. (a) (1) The presiding officer at...

  3. 45 CFR 99.2 - Presiding officer.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Presiding officer. 99.2 Section 99.2 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND General § 99.2 Presiding officer. (a) (1) The presiding officer at...

  4. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional...

  5. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  6. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  7. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities...

  8. 50 CFR 665.99 - Area restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Area restrictions. 665.99 Section 665.99 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC American Samoa Fisheries § 665.99 Area...

  9. 29 CFR 99.405 - Management decision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Management decision. 99.405 Section 99.405 Labor Office of... Agencies and Pass-through Entities § 99.405 Management decision. (a) General. The management decision shall... the management decision, the Federal agency or pass-through entity may request additional information...

  10. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

  11. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

  12. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

  13. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

  14. 14 CFR 99.49 - Hawaii ADIZ.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

  15. 25 CFR 700.99 - Salvage value.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Salvage value. 700.99 Section 700.99 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.99 Salvage value. Salvage value means the probable sale price of an...

  16. 7 CFR 27.99 - Values; expression.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Values; expression. 27.99 Section 27.99 Agriculture... CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Price Quotations and Differences § 27.99 Values; expression. For the purpose of this subpart values shall be expressed in terms of cents and hundredths of a...

  17. 29 CFR 99.400 - Responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Responsibilities. 99.400 Section 99.400 Labor Office of the... Pass-through Entities § 99.400 Responsibilities. (a) Cognizant agency for audit responsibilities... programs of more than one agency. (8) Coordinate the audit work and reporting responsibilities among...

  18. 14 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Definitions. 99.3 Section 99.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.3 Definitions. Aeronautical...

  19. 14 CFR 99.15 - Position reports.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Position reports. 99.15 Section 99.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.15 Position reports. (a)...

  20. 14 CFR 99.12 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false 99.12 Section 99.12 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.12...

  1. 14 CFR 99.5 - Emergency situations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Emergency situations. 99.5 Section 99.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.5 Emergency situations. In...

  2. 14 CFR 99.1 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Applicability. 99.1 Section 99.1 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.1 Applicability. (a)...

  3. 29 CFR 99.200 - Audit requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Audit requirements. 99.200 Section 99.200 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.200 Audit requirements. (a) Audit required. Non-Federal entities that expend $300,000 or more in a...

  4. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230 Audit costs. (a) Allowable costs. Unless prohibited by law, the cost of audits made in accordance with the...

  5. 29 CFR 99.505 - Audit reporting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Audit reporting. 99.505 Section 99.505 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.505 Audit... the audit was conducted in accordance with this part and include the following: (a) An opinion (or...

  6. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  7. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  8. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  9. 14 CFR 99.41 - General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  10. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  11. 14 CFR 99.41 - General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  12. 14 CFR 99.41 - General.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  13. 14 CFR 99.41 - General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  14. 14 CFR 99.41 - General.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

  15. 32 CFR 552.99 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Applicability. 552.99 Section 552.99 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Firearms and Weapons § 552.99 Applicability. (a)...

  16. 32 CFR 552.99 - Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Applicability. 552.99 Section 552.99 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Firearms and Weapons § 552.99 Applicability. (a)...

  17. 14 CFR 99.12 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false 99.12 Section 99.12 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.12 ...

  18. 14 CFR 99.12 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false 99.12 Section 99.12 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.12 ...

  19. 14 CFR 99.15 - Position reports.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Position reports. 99.15 Section 99.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.15 Position reports. (a) The...

  20. 14 CFR 99.12 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false 99.12 Section 99.12 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.12 ...

  1. 14 CFR 99.15 - Position reports.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Position reports. 99.15 Section 99.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.15 Position reports. (a) The...

  2. 14 CFR 99.15 - Position reports.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Position reports. 99.15 Section 99.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.15 Position reports. (a) The...

  3. 14 CFR 99.5 - Emergency situations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Emergency situations. 99.5 Section 99.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.5 Emergency situations. In an...

  4. 14 CFR 99.12 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false 99.12 Section 99.12 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.12 ...

  5. 14 CFR 99.5 - Emergency situations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Emergency situations. 99.5 Section 99.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.5 Emergency situations. In an...

  6. 14 CFR 99.5 - Emergency situations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Emergency situations. 99.5 Section 99.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.5 Emergency situations. In an...

  7. 14 CFR 99.15 - Position reports.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Position reports. 99.15 Section 99.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.15 Position reports. (a) The...

  8. 14 CFR 99.5 - Emergency situations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Emergency situations. 99.5 Section 99.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.5 Emergency situations. In an...

  9. 29 CFR 99.510 - Audit findings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Audit findings. 99.510 Section 99.510 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditors § 99.510 Audit findings. (a) Audit findings reported. The auditor shall report the following as audit findings in...

  10. 29 CFR 99.230 - Audit costs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Audit costs. 99.230 Section 99.230 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.230 Audit costs. (a) Allowable costs. Unless prohibited by law, the cost of audits made in accordance with...

  11. 29 CFR 99.200 - Audit requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Audit requirements. 99.200 Section 99.200 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.200 Audit requirements. (a) Audit required. Non-Federal entities that expend $300,000 or more in...

  12. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire door...

  13. 46 CFR 111.99-5 - General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false General. 111.99-5 Section 111.99-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-5 General. Fire door release systems, if installed, must meet...

  14. 46 CFR 111.99-5 - General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false General. 111.99-5 Section 111.99-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-5 General. Fire door release systems, if installed, must...

  15. 46 CFR 111.99-1 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Applicability. 111.99-1 Section 111.99-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Fire Door Holding and Release Systems § 111.99-1 Applicability. This subpart applies to fire...

  16. 29 CFR 99.100 - Purpose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Purpose. 99.100 Section 99.100 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS General § 99.100 Purpose... audit of non-Federal entities expending Federal awards. ...

  17. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Evidence. 99.25 Section 99.25 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally under... conference or otherwise prior to the hearing if the presiding officer so requires. (c) Rules of...

  18. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Evidence. 99.25 Section 99.25 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally under... conference or otherwise prior to the hearing if the presiding officer so requires. (c) Rules of...

  19. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Evidence. 99.25 Section 99.25 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally under... conference or otherwise prior to the hearing if the presiding officer so requires. (c) Rules of...

  20. 45 CFR 99.25 - Evidence.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Evidence. 99.25 Section 99.25 Public Welfare... DEVELOPMENT FUND Hearing Procedures § 99.25 Evidence. (a) Testimony. Testimony shall be given orally under... conference or otherwise prior to the hearing if the presiding officer so requires. (c) Rules of...

  1. 45 CFR 99.2 - Presiding officer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Presiding officer. 99.2 Section 99.2 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE CHILD CARE AND DEVELOPMENT FUND General § 99.2 Presiding officer. (a) (1) The presiding officer at...

  2. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education. The...

  3. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education. The...

  4. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education. The...

  5. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  6. 15 CFR 9.9 - Consumer education.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Consumer education. 9.9 Section 9.9 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR A VOLUNTARY LABELING PROGRAM FOR HOUSEHOLD APPLIANCES AND EQUIPMENT TO EFFECT ENERGY CONSERVATION § 9.9 Consumer education....

  7. Is matching ruthenium with dithiocarbamato ligands a potent chemotherapeutic weapon in oncology?

    PubMed

    Nardon, Chiara; Brustolin, Leonardo; Fregona, Dolores

    2016-01-01

    In the last years, several metal-based compounds have been designed and biologically investigated worldwide in order to obtain chemotherapeutics with a better toxicological profile and comparable or higher antiblastic activity than the clinically-established platinum-based drugs. In this context, researchers have addressed their attention to alternative nonplatinum derivatives able to maximize the anticancer activity of the new drugs and to minimize the side effects. Among them, a number of ruthenium complexes have been developed, including the compounds NAMI-A and KP1019, now in clinical trials. Here, we report the results collected so far for a particular class of ruthenium complexes - the ruthenium(II/III)-dithiocarbamates - which proved more potent than cisplatin in vitro, even at nanomolar concentrations, against a wide panel of human tumor cell lines.

  8. Recent advances in ruthenium complex-based light-driven water oxidation catalysts.

    PubMed

    Xue, Long-Xin; Meng, Ting-Ting; Yang, Wei; Wang, Ke-Zhi

    2015-11-01

    The light driven splitting of water is one of the most attractive approaches for direct conversion of solar energy into chemical energy in the future. Ruthenium complexes as the water oxidation catalysts (WOCs) and light sensitizers have attracted increasing attention, and have made a great progress. This mini-review highlights recent progress on ruthenium complex-based photochemical and photoelectrochemical water oxidation catalysts. The recent representative examples of these ruthenium complexes that are in homogeneous solution or immobilized on solid electrodes, are surveyed. In particular, special attention has been paid on the supramolecular dyads with photosensitizer and WOC being covalently hold together, and grafted onto the solid electrode. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Disaggregation of human islet amyloid polypeptide fibril formation by ruthenium polypyridyl complexes.

    PubMed

    Zhu, Dengsen; Gong, Gehui; Wang, Wenji; Du, Weihong

    2017-05-01

    The toxicity of amyloid proteins is associated with many degenerative and systematic diseases. The aggregation of human islet amyloid polypeptide may induce pancreatic β-cell death, which is linked to type II diabetes. Ruthenium complexes are inhibitors of various proteins and potential anticancer metallodrugs, which can also be used to disaggregate amyloid proteins. This work reported that several ruthenium polypyridyl complexes remarkably affected the peptide aggregation by predominant hydrophobic interaction and metal coordination, as reflected by thermodynamic parameters and mass spectrometry analysis. Morphology and particle size analysis showed that the amyloid fibrils were disaggregated from long fibrils into small nano particles. Addition of these complexes also decreased the cytotoxicity induced by the peptide. The results indicated that ruthenium polypyridyl complexes may be potential metallodrugs to treat amyloidosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

    PubMed Central

    Jimenez, Leonel R.; Tolentino, Daniel R.; Gallon, Benjamin J.; Schrodi, Yann

    2012-01-01

    The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh3)3 and RuCl2(pcymene)(L), where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-npropylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes. PMID:22580400

  11. TCP suppression in a ruthenium-bearing single-crystal nickel-based superalloy

    NASA Astrophysics Data System (ADS)

    Hobbs, R. A.; Zhang, L.; Rae, C. M. F.; Tin, S.

    2008-07-01

    Ruthenium suppresses the precipitation of deleterious topologically close-packed (TCP) phases in high refractory content single-crystal nickel-based superalloys. The effectiveness of ruthenium as a TCP suppressant appears to be the net effect of its limited solubility in the TCP phase, a lower density of structural growth ledges for atomic attachment at the TCP/matrix interface, and destabilization of the γ' phase at elevated temperatures. These characteristics combine to limit the growth rates of TCP precipitates and decrease the driving force for their precipitation. Destabilization of the γ' phase upon the addition of ruthenium is particularly potent due to the sensitivity of the rhenium content in the γ matrix to changes in the γ' volume fraction.

  12. Conduction electron g-factors in ruthenium and osmium from de Haas-van Alphen measurements

    NASA Astrophysics Data System (ADS)

    Startsev, V. E.; Coleridge, P. T.; Templeton, I. M.; Fawcett, E.; Muir, C.; Perz, J. M.

    1984-04-01

    Conduction electron g-factors have been deduced from de Haas-van Alphen line shapes in the hexagonal group VIII 4 d transition metal ruthenium and the electronically analogous 5 d metal osmium. The values for orbits normal to [0001] are 1.8±0.1 and 1.3±0.1 for the ellipsoids centered on the line LM in ruthenium and osmium, respectively, and 1.9±0.2 for the Γ-centered ellipsoid in ruthenium. The more marked suppression of the g-factor in osmium, where spin-orbit coupling is stronger, is consistent with recent theoretical studies of transition metal g-factor trends.

  13. Nonlinear optics and surface relief gratings in alkynyl-ruthenium complexes

    NASA Astrophysics Data System (ADS)

    Sahraoui, B.; Luc, J.; Meghea, A.; Czaplicki, R.; Fillaut, J.-L.; Migalska-Zalas, A.

    2009-02-01

    Generally, the organometallic complexes rich in carbon and containing π-conjugated chains are materials interesting for the study of electronic transfer processes. Currently, the ruthenium-acetylide organometallic complexes form part of the most studied organometallic compounds in nonlinear optics. In this work, we highlight the nonlinear optical properties and the photo-induced structure of new organometallic complexes containing a ruthenium-acetylide donor fragment able to compete with the strongest organic donors. We determine, using various experimental techniques (degenerate four-wave mixing, second and third harmonic generation), the influence of the functionalization of these molecular structures on the improvement of their second-and third-order nonlinear optical properties exploiting in particular the nature of the acceptor fragment and the π-conjugated transmitter. Also we present the dynamics of formation of photo-induced surface relief gratings using a transmission holographic technique and the atomic force microscopy on ruthenium-acetylide complexes containing an azobenzene fragment.

  14. Isomerization of methyl linoleate on ruthenium(III) alkoxide complex; Mathematical modeling

    SciTech Connect

    Mukesh, D.; Narasimhan, C.S.; Ramnarayan, K.; Deshpande, V.M

    1989-08-01

    The isomerization of methyl linoleate using ruthenium alkoxide complexes is described. With alcohols, such as isopropyl alcohol (IPA), 1-butanol, 1-hexanol, and 1-octanol, isomerization of double bonds to produce a conjugated system is the main reaction, with hydrogenation being the side reaction. The latter is formed via the conjugated product. Based on kinetic and infrared spectroscopic data, it is concluded that the active catalytic species is a ruthenium hydride complex formed by the decomposition of the unstable alkoxide. The reaction is mathematically modeled, and the rate parameters are obtained by fitting the simulation to experimental data. These values are compared with data obtained from reactions carried out with supported ruthenium-nickel heterogeneous catalyst.

  15. Synthesis, characterization, DNA interaction and in vitro cytotoxicity activities of ruthenium(II) Schiff base complexes

    NASA Astrophysics Data System (ADS)

    Sathiyaraj, Subbaiyan; Butcher, Ray J.; Jayabalakrishnan, Chinnasamy

    2012-12-01

    DNA binding, cleavage and cytotoxicity characteristics of a novel Schiff base ligand 3-(benzothiazol-2-yliminomethyl)-naphthalen-2-ol and ruthenium(II) complexes have been investigated. The DNA interaction properties of the complexes have been investigated using absorption spectra, as well as gel electrophoresis studies. Intrinsic binding constant (Kb) has been estimated under similar set of experimental conditions. Absorption spectral study indicate that the ligand and ruthenium(II) complexes has intrinsic binding constant in the range of 1.4-7.2 × 104 M-1. Ruthenium(II) complexes show more binding ability than the ligand. Further, in vitro cytotoxicity study of the ligand and the complexes exhibited antitumor activity against HeLa and HEp2 tumor cells.

  16. Stoichiometric photoisomerization of mononuclear ruthenium(II) monoaquo complexes controlling redox properties and water oxidation catalysis.

    PubMed

    Yamazaki, Hirosato; Hakamata, Tomoya; Komi, Manabu; Yagi, Masayuki

    2011-06-15

    Although various reactions involved in photoexcited states of polypyridyl ruthenium(II) complexes have been extensively studied, photoisomerization of the complexes is very rare. We report the first illustration of stoichiometric photoisomerization of trans-[Ru(tpy)(pynp)OH(2)](2+) (1a) [tpy = 2,2':6',2''-terpyridine; pynp = 2-(2-pyridyl)-1,8-naphthyridine] to cis-[Ru(tpy)(pynp)OH(2)](2+) (1a') and the isolation of 1a and 1a' for X-ray crystallographic analysis. Polypyridyl ruthenium(II) aquo complexes are attracting much attention related to proton-coupled electron transfer and water oxidation catalysis. We demonstrate that the photoisomerization significantly controls the redox reactions and water oxidation catalyses involving the ruthenium(II) aquo complexes 1a and 1a'.

  17. Ruthenium red inhibits tail skin vasodilatation evoked by intracerebroventricular injection of capsaicin in the rat.

    PubMed

    Hajós, M; Jancsó, G; Mari, Z; Obál, F

    1991-04-01

    The effect of Ruthenium red on the tail skin vasodilatation evoked by an intracerebroventricular injection of capsaicin was studied in the anesthetized rat. Injection of capsaicin into the lateral ventricle resulted in a marked elevation of the tail skin temperature, indicative of peripheral vasodilatation. Ruthenium red, given by intracerebroventricular injection, significantly inhibited this response, which is known to be mediated by central warmth-sensitive neuronal structures. The findings suggest that the sensitivity to Ruthenium red, reportedly characteristic of the capsaicin-sensitive neurons in the peripheral nervous system, is also a trait of the capsaicin-sensitive nerve cells in the central nervous system. This is the first evidence indicating that similar molecular mechanisms, presumably involving changes in cellular calcium metabolism, contribute to the capsaicin-induced activation of neurons in both the peripheral and central nervous systems.

  18. Rigid 5'-6-locked phenanthroline-derived nucleosides chelated to ruthenium and europium ions.

    PubMed

    Gislason, Kristmann; Sigurdsson, Snorri Th

    2013-01-01

    We describe complexes of ruthenium and europium with rigid, 5'-6-locked 1,10-phenanthroline-containing nucleosides. Both nucleosides were synthesized from condensation of 5-amino-2'-deoxycytidine with the corresponding diketone. The ruthenium nucleoside displayed fluorescence characteristic of polypyridine ruthenium complexes with a maximum at 616 nm and a quantum yield of 0.011. Binding of europium to the 1,10-phenanthroline-2,9-diacid moiety of the lanthanide binding nucleoside showed formation of a 1:1 complex with emission at 570-630 nm, whose emission was enhanced by addition of two phenanthroline ligands. The lanthanide-binding nucleoside was incorporated into DNA oligonucleotides and shown to selectively bind one equivalent of europium ions.

  19. Hydrodefluorination of carbon-fluorine bonds by the synergistic action of a ruthenium-palladium catalyst.

    PubMed

    Sabater, Sara; Mata, Jose A; Peris, Eduardo

    2013-01-01

    Catalytic hydrodefluorination of organic molecules is a major organometallic challenge, owing to the strength of C-F sigma bonds, and it is a process with multiple industrial applications. Here we report a new heterodimetallic ruthenium-palladium complex based on a triazolyl-di-ylidene ligand. The complex is remarkably active in the hydrodefluorination of aromatic and aliphatic carbon-fluorine bonds under mild reaction conditions. We observe that both metals are required to promote the reaction process. The overall process implies that the palladium fragment facilitates the C-F activation, whereas the ruthenium centre allows the reduction of the substrate via transfer hydrogenation from isopropanol/sodium t-butoxide. The activity of this heterodimetallic complex is higher than that shown by a mixture of the related homodimetallic complexes of ruthenium and palladium, demonstrating the catalytic benefits of the heterodimetallic complex linked by a single-frame ligand.

  20. Isotopic separation of D sub 2 O from H sub 2 O using ruthenium adsorbent

    SciTech Connect

    Thiel, P.A.

    1990-04-10

    This paper describes a one-phase method for enriching the concentration of D{sub 2}O in solutions of D{sub 2}O and H{sub 2}O. It comprises: contacting in the absence of hydrogen gas steam phase D{sub 2}O and steam phase H{sub 2}O, with the hexagonal surface of crystalline ruthenium having a particle size greater than 10 nanometers so that sufficient (001) face is exposed to produce enriched D{sub 2}O. Also described is a one-phase method of enriching the concentration of D{sub 2}O and solutions of D{sub 2}O and H{sub 2}O. It comprises: contacting the D{sub 2}O and H{sub 2}O in the steam phase with the hexagonal surface of crystalline ruthenium wherein the ruthenium is divided into particles of about 1 micron to produce enriched D{sub 2}O.

  1. Future of low specific activity molybdenum-99/technetium-99m generator.

    PubMed

    Mushtaq, A

    2012-10-01

    In last few years, the shortage of molybdenum-99 (99Mo) was felt in the developed and developing countries hospitals, where diagnostic nuclear medicine is practiced. To overcome the shortage of 99Mo various routes of its production by accelerators and reactors generating low and high specific activity products have been planned. High specific activity 99Mo obtained by fission of uranium-235 (235U) has completely dominated in the manufacturing of technetium-99m (99mTc) generators in last 3-4 decades, but due to proliferation and dirty bomb, issues non fission routes of 99Mo production are emphasized. Future of low specific activity 99Mo is discussed.

  2. Water oxidation by Ruthenium complexes incorporating multifunctional biipyridyl diphosphonate ligands

    DOE PAGES

    Xie, Yan; Shaffer, David W.; Lewandowska-Andralojc, Anna; ...

    2016-05-11

    Here, we describe herein the synthesis and characterization of ruthenium complexes with multifunctional bipyridyl diphosphonate ligands as well as initial water oxidation studies. In these complexes, the phosphonate groups provide redox-potential leveling through charge compensation and σ donation to allow facile access to high oxidation states. These complexes display unique pH-dependent electrochemistry associated with deprotonation of the phosphonic acid groups. The position of these groups allows them to shuttle protons in and out of the catalytic site and reduce activation barriers. A mechanism for water oxidation by these catalysts is proposed on the basis of experimental results and DFT calculations.more » The unprecedented attack of water at a neutral six-coordinate [RuIV] center to yield an anionic seven-coordinate [RuIV–OH]– intermediate is one of the key steps of a single-site mechanism in which all species are anionic or neutral. These complexes are among the fastest single-site catalysts reported to date.« less

  3. Ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbenes.

    PubMed

    Paradiso, Veronica; Bertolasi, Valerio; Costabile, Chiara; Grisi, Fabia

    2016-01-14

    New ruthenium Grubbs' and Hoveyda-Grubbs' second generation catalysts bearing N-alkyl/N-isopropylphenyl N-heterocyclic carbene (NHC) ligands with syn or anti backbone configuration were obtained and compared in model olefin metathesis reactions. Different catalytic efficiencies were observed depending on the size of the N-alkyl group (methyl or cyclohexyl) and on the backbone configuration. The presence of an N-cyclohexyl substituent determined the most significant reactivity differences between catalysts with syn or anti phenyl groups on the backbone. In particular, anti catalysts proved highly efficient, especially in the ring-closing metathesis (RCM) of encumbered diolefins, while syn catalysts showed low efficiency in the RCM of less hindered diolefins. This peculiar behavior, rationalized through DFT studies, was found to be related to the high propensity of these catalysts to give nonproductive metathesis events. Enantiopure anti catalysts were also tested in asymmetric metathesis reactions, where moderate enantioselectivities were observed. The steric and electronic properties of unsymmetrical NHCs with the N-cyclohexyl group were then evaluated using the corresponding rhodium complexes. While steric factors proved unimportant for both syn and anti NHCs, a major electron-donating character was found for the unsymmetrical NHC with anti phenyl substituents on the backbone.

  4. Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments

    SciTech Connect

    Vecchi, Paul Anthony

    2005-01-01

    This dissertation contains five papers in the format required for journal publication which describe (in part) my research accomplishments as a graduate student at Iowa State University. This work can be broadly categorized as the binding of weakly-coordinating ligands to cationic organometallic ruthenium fragments, and consists of two main areas of study. Chapters 2-4 are investigations into factors that influence the binding of dibenzothiophenes to [Cp'Ru(CO)2(+ fragments, where Cp' = η5-C5H5 (Cp) and η5-C5Me5 (Cp*). Chapters 5 and 6 present the synthesis and structural characterization of complexes containing corannulene buckybowls that are η6-coordinated to [Cp*Ru(+ fragments. The first chapter contains a brief description of the difficulty in lowering sulfur levels in diesel fuel along with a review of corannulene derivatives and their metal complexes. After the final paper is a short summary of the work herein (Chapter 7). Each chapter is independent, and all equations, schemes, figures, tables, references, and appendices in this dissertation pertain only to the chapter in which they appear.

  5. Highly efficient and robust molecular ruthenium catalysts for water oxidation.

    PubMed

    Duan, Lele; Araujo, Carlos Moyses; Ahlquist, Mårten S G; Sun, Licheng

    2012-09-25

    Water oxidation catalysts are essential components of light-driven water splitting systems, which could convert water to H(2) driven by solar radiation (H(2)O + hν → 1/2O(2) + H(2)). The oxidation of water (H(2)O → 1/2O(2) + 2H(+) + 2e(-)) provides protons and electrons for the production of dihydrogen (2H(+) + 2e(-) → H(2)), a clean-burning and high-capacity energy carrier. One of the obstacles now is the lack of effective and robust water oxidation catalysts. Aiming at developing robust molecular Ru-bda (H(2)bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) water oxidation catalysts, we carried out density functional theory studies, correlated the robustness of catalysts against hydration with the highest occupied molecular orbital levels of a set of ligands, and successfully directed the synthesis of robust Ru-bda water oxidation catalysts. A series of mononuclear ruthenium complexes [Ru(bda)L(2)] (L = pyridazine, pyrimidine, and phthalazine) were subsequently synthesized and shown to effectively catalyze Ce(IV)-driven [Ce(IV) = Ce(NH(4))(2)(NO(3))(6)] water oxidation with high oxygen production rates up to 286 s(-1) and high turnover numbers up to 55,400.

  6. Homobimetallic Ruthenium-N-Heterocyclic Carbene Complexes For Olefin Metathesis

    NASA Astrophysics Data System (ADS)

    Sauvage, Xavier; Demonceau, Albert; Delaude, Lionel

    In this chapter, the synthesis and catalytic activity towards olefin metathesis of homobimetallic ruthenium (Ru)-alkylidene, -cyclodiene or -arene complexes bearing phosphine or N-heterocyclic carbene (NHC) ligands are reviewed. Emphasis is placed on the last category of bimetallic compounds. Three representatives of this new type of molecular scaffold were investigated. Thus, [(p-cymene)Ru(m-Cl)3RuCl (h2-C2H4)(L)] complexes with L = PCy3 (15a), IMes (16a), or IMesCl2 (16b) were prepared. They served as catalyst precursors for cross-metathesis (CM) of various styrene derivatives. These experiments revealed the outstanding aptitude of complex 16a (and to a lesser extent of 16b) to catalyze olefin metathesis reactions. Contrary to monometallic Ru-arene complexes of the [RuCl2(p-cymene)(L)] type, the new homobimetallic species did not require the addition of a diazo compound nor visible light illumination to initiate the ring-opening metathesis of norbornene or cyclooctene. When diethyl 2,2-diallylmalonate and N,N-diallyltosylamide were exposed to 16a,b, a mixture of cycloisomerization and ring-closing metathesis (RCM) products was obtained in a nonselective way. Addition of phenylacetylene enhanced the metathetical activity while completely repressing the cycloisomerization process.

  7. Water oxidation by Ruthenium complexes incorporating multifunctional biipyridyl diphosphonate ligands

    SciTech Connect

    Xie, Yan; Shaffer, David W.; Lewandowska-Andralojc, Anna; Szalda, David J.; Concepcion, Javier J.

    2016-05-11

    Here, we describe herein the synthesis and characterization of ruthenium complexes with multifunctional bipyridyl diphosphonate ligands as well as initial water oxidation studies. In these complexes, the phosphonate groups provide redox-potential leveling through charge compensation and σ donation to allow facile access to high oxidation states. These complexes display unique pH-dependent electrochemistry associated with deprotonation of the phosphonic acid groups. The position of these groups allows them to shuttle protons in and out of the catalytic site and reduce activation barriers. A mechanism for water oxidation by these catalysts is proposed on the basis of experimental results and DFT calculations. The unprecedented attack of water at a neutral six-coordinate [RuIV] center to yield an anionic seven-coordinate [RuIV–OH] intermediate is one of the key steps of a single-site mechanism in which all species are anionic or neutral. These complexes are among the fastest single-site catalysts reported to date.

  8. Water oxidation by Ruthenium complexes incorporating multifunctional biipyridyl diphosphonate ligands

    SciTech Connect

    Xie, Yan; Shaffer, David W.; Lewandowska-Andralojc, Anna; Szalda, David J.; Concepcion, Javier J.

    2016-05-11

    Here, we describe herein the synthesis and characterization of ruthenium complexes with multifunctional bipyridyl diphosphonate ligands as well as initial water oxidation studies. In these complexes, the phosphonate groups provide redox-potential leveling through charge compensation and σ donation to allow facile access to high oxidation states. These complexes display unique pH-dependent electrochemistry associated with deprotonation of the phosphonic acid groups. The position of these groups allows them to shuttle protons in and out of the catalytic site and reduce activation barriers. A mechanism for water oxidation by these catalysts is proposed on the basis of experimental results and DFT calculations. The unprecedented attack of water at a neutral six-coordinate [RuIV] center to yield an anionic seven-coordinate [RuIV–OH] intermediate is one of the key steps of a single-site mechanism in which all species are anionic or neutral. These complexes are among the fastest single-site catalysts reported to date.

  9. Ruthenium oxide modified nickel electrode for ascorbic acid detection.

    PubMed

    Lee, Yuan-Gee; Liao, Bo-Xuan; Weng, Yu-Ching

    2017-04-01

    Electrodes of ruthenium oxide modified nickel were prepared by a thermal decomposition method. The stoichiometry of the modifier, RuOx, was quantitatively determined to be a meta-stable phase, RuO5. The electrodes were employed to sense ascorbic acid in alkaline solution with a high sensitivity, 296 μAcm(-2) mM(-1), and good selectivity for eight kinds of disturbing reagents. We found that the ascorbic acid was oxidized irreversibly in solution. To match with the variation of the morphology, the sensitivity reached a maximum when the RuOx segregated with a nano-crystalline feature. We find that the substrate oxidized as the deposited RuOx grew thicker. The feature of the deposited RuOx changed from nano-particles to small islands resulting from the wetting effect of the substrate oxide, NiO; meanwhile the sensitivity decreased dramatically. The endurance of the RuOx/Ni electrode also showed a good performance after 38 days of successive test.

  10. Synthesis of ruthenium particles by photoreduction in polymer solutions.

    PubMed

    Harada, Masafumi; Takahashi, Saki

    2008-09-01

    Colloidal dispersions of poly(N-vinyl-2-pyrrolidone)-protected ruthenium (Ru) particles have been synthesized by the photoreduction of Ru(III) ionic solutions in the presence of photo-activator such as benzophenone and benzoin. The size and the structure of the synthesized particles have been extensively investigated by UV-vis, transmission electron micrograph (TEM) and extended X-ray absorption fine structure (EXAFS). Metallic Ru particles with an average diameter of 1.3 nm were successfully synthesized in the presence of benzophenone, although mixtures of partly oxidized Ru particles and metallic Ru particles were synthesized in the presence of benzoin. Photoreduction of Ru(III) ionic precursors to Ru atoms was promoted by ketyl radicals, which is more efficiently generated by the photoirradiation of benzophenone than by that of benzoin. The photoirradiation of benzophenone in the Ru(III) ionic solutions is an efficient and convenient method to produce metallic Ru particles in polymer solutions rather than the refluxing and the hydrothermal method of ionic solutions of Ru.

  11. Fabrication Technology of Ruthenium Microelectrode Pattern for RF MEMS

    NASA Astrophysics Data System (ADS)

    Matsumura, Takeshi; Esashi, Masayoshi; Harada, Hiroshi; Tanaka, Shuji

    Ruthenium (Ru), which is one of noble metals, has been intensively considered as an electrode material of DRAM capacitors, since Ru has high oxidation resistance and high electrical conductivity even in the oxidized state. Furthermore, Ru is also expected to be used as an electrode material of acoustic devices, e.g. FBAR, because of its superior acoustic properties such as high Young's modulus and density. For such applications, a precise etching technique for Ru microelectrode patterns is required. Ru etching proceeds by producing volatile oxidized Ru (RuO4), and is possible using plasma with O2 or O2 plus halogenous gas, e.g. Cl2 and CF4. However, the plasma etching also attacks resist and/or an underlayer of Si, SiN etc. In this study, a wet etching process with cerium (IV) ammonium nitrate (CAN)-based etchant and a dry etching process with O3 gas were investigated as low-damage Ru etching processes. O3 gas etching is better for patterning Ru microelectrodes than CAN-based wet etching. For O3 gas etching, diluted HF pretreatment is effective to reduce side etching and to improve etching uniformity

  12. Highly efficient and robust molecular ruthenium catalysts for water oxidation

    PubMed Central

    Duan, Lele; Araujo, Carlos Moyses; Ahlquist, Mårten S.G.; Sun, Licheng

    2012-01-01

    Water oxidation catalysts are essential components of light-driven water splitting systems, which could convert water to H2 driven by solar radiation (H2O + hν → 1/2O2 + H2). The oxidation of water (H2O → 1/2O2 + 2H+ + 2e-) provides protons and electrons for the production of dihydrogen (2H+ + 2e- → H2), a clean-burning and high-capacity energy carrier. One of the obstacles now is the lack of effective and robust water oxidation catalysts. Aiming at developing robust molecular Ru-bda (H2bda = 2,2′-bipyridine-6,6′-dicarboxylic acid) water oxidation catalysts, we carried out density functional theory studies, correlated the robustness of catalysts against hydration with the highest occupied molecular orbital levels of a set of ligands, and successfully directed the synthesis of robust Ru-bda water oxidation catalysts. A series of mononuclear ruthenium complexes [Ru(bda)L2] (L = pyridazine, pyrimidine, and phthalazine) were subsequently synthesized and shown to effectively catalyze CeIV-driven [CeIV = Ce(NH4)2(NO3)6] water oxidation with high oxygen production rates up to 286 s-1 and high turnover numbers up to 55,400. PMID:22753518

  13. Diverse ruthenium nitrides stabilized under pressure: a theoretical prediction

    PubMed Central

    Zhang, Yunkun; Wu, Lailei; Wan, Biao; Lin, Yangzheng; Hu, Qingyang; Zhao, Yan; Gao, Rui; Li, Zhiping; Zhang, Jingwu; Gou, Huiyang

    2016-01-01

    First-principles calculations were performed to understand the structural stability, synthesis routes, mechanical and electronic properties of diverse ruthenium nitrides. RuN with a new I-4m2 symmetry stabilized by pressure is found to be energetically preferred over the experimental NaCl-type and ZnS-type ones. The Pnnm-RuN2 is found to be stable above 1.1 GPa, in agreement with the experimental results. Specifically, new stoichiometries like RuN3 and RuN4 are proposed firstly to be thermodynamically stable, and the dynamical and mechanical stabilities of the newly predicted structures have been verified by checking their phonon spectra and elastic constants. A phase transition from P4/mmm-RuN4 to C2/c-RuN4 is also uncovered at 23.0 GPa. Drawn from bonding and band structure analysis, P4/mmm-RuN4 exhibits semi-metal-like behavior and becomes a semiconductor for the high-pressure C2/c-RuN4 phase. Meanwhile the P21/c-RuN3 shows metallic feature. Highly directional covalent N-N and Ru-N bonds are formed and dominating in N-enriched Ru nitrides, making them promising hard materials. PMID:27627856

  14. Sweetening ruthenium and osmium: organometallic arene complexes containing aspartame.

    PubMed

    Gray, Jennifer C; Habtemariam, Abraha; Winnig, Marcel; Meyerhof, Wolfgang; Sadler, Peter J

    2008-09-01

    The novel organometallic sandwich complexes [(eta(6)-p-cymene)Ru(eta(6)-aspartame)](OTf)(2) (1) (OTf = trifluoromethanesulfonate) and [(eta(6)-p-cymene)Os(eta(6)-aspartame)](OTf)(2) (2) incorporating the artificial sweetener aspartame have been synthesised and characterised. A number of properties of aspartame were found to be altered on binding to either metal. The pK(a) values of both the carboxyl and the amino groups of aspartame are lowered by between 0.35 and 0.57 pH units, causing partial deprotonation of the amino group at pH 7.4 (physiological pH). The rate of degradation of aspartame to 3,6-dioxo-5-phenylmethylpiperazine acetic acid (diketopiperazine) increased over threefold from 0.12 to 0.36 h(-1) for 1, and to 0.43 h(-1) for 2. Furthermore, the reduction potential of the ligand shifted from -1.133 to -0.619 V for 2. For the ruthenium complex 1 the process occurred in two steps, the first (at -0.38 V) within a biologically accessible range. This facilitates reactions with biological reductants such as ascorbate. Binding to and activation of the sweet taste receptor was not observed for these metal complexes up to concentrations of 1 mM. The factors which affect the ability of metal-bound aspartame to interact with the receptor site are discussed.

  15. Dual-targeting organometallic ruthenium(II) anticancer complexes bearing EGFR-inhibiting 4-anilinoquinazoline ligands.

    PubMed

    Zhang, Yang; Zheng, Wei; Luo, Qun; Zhao, Yao; Zhang, Erlong; Liu, Suyan; Wang, Fuyi

    2015-08-07

    We have recently demonstrated that complexation with (η(6)-arene)Ru(II) fragments confers 4-anilinoquinazoline pharmacophores a higher potential for inducing cellular apoptosis while preserving the highly inhibitory activity of 4-anilinoquinazolines against EGFR and the reactivity of the ruthenium centre to 9-ethylguanine (Chem. Commun., 2013, 49, 10224-10226). Reported herein are the synthesis, characterisation and evaluation of the biological activity of a new series of ruthenium(ii) complexes of the type [(η(6)-arene)Ru(N,N-L)Cl]PF6 (arene = p-cymene, benzene, 2-phenylethanol or indane, L = 4-anilinoquinazolines). These organometallic ruthenium complexes undergo fast hydrolysis in aqueous solution. Intriguingly, the ligation of (arene)Ru(II) fragments with 4-anilinoquinazolines not only makes the target complexes excellent EGFR inhibitors, but also confers the complexes high affinity to bind to DNA minor grooves while maintaining their reactivity towards DNA bases, characterising them with dual-targeting properties. Molecular modelling studies reveal that the hydrolysis of these complexes is a favourable process which increases the affinity of the target complexes to bind to EGFR and DNA. In vitro biological activity assays show that most of this group of ruthenium complexes are selectively active inhibiting the EGF-stimulated growth of the HeLa cervical cancer cell line, and the most active complex [(η(6)-arene)Ru(N,N-L13)Cl]PF6 (, IC50 = 1.36 μM, = 4-(3'-chloro-4'-fluoroanilino)-6-(2-(2-aminoethyl)aminoethoxy)-7-methoxyquinazoline) is 29-fold more active than its analogue, [(η(6)-arene)Ru(N,N-ethylenediamine)Cl]PF6, and 21-fold more active than gefitinib, a well-known EGFR inhibitor in use clinically. These results highlight the strong promise to develop highly active ruthenium anticancer complexes by ligation of cytotoxic ruthenium pharmacophores with bioactive organic molecules.

  16. Ruthenium(III) catalyzed oxidation of sugar alcohols by dichloroisocyanuric acid—A kinetic study

    NASA Astrophysics Data System (ADS)

    Lakshman Kumar, Y.; Venkata Nadh, R.; Radhakrishnamurti, P. S.

    2016-02-01

    Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol, D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid—perchloric medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed.

  17. Bis(Cyclic Alkyl Amino Carbene) Ruthenium Complexes: A Versatile, Highly Efficient Tool for Olefin Metathesis

    PubMed Central

    Gawin, Rafał; Kozakiewicz, Anna; Guńka, Piotr A.; Dąbrowski, Paweł

    2016-01-01

    Abstract The state‐of‐the‐art in olefin metathesis is application of N‐heterocyclic carbene (NHC)‐containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)‐containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported. PMID:27943616

  18. Hydrogenation of Carbon Dioxide to Methane by Ruthenium Nanoparticles in Ionic Liquid.

    PubMed

    Melo, Catarina I; Szczepańska, Anna; Bogel-Łukasik, Ewa; Nunes da Ponte, Manuel; Branco, Luís C

    2016-05-23

    The efficient transformation of carbon dioxide into fuels can be an excellent alternative to sequestration. In this work, we describe CO2 hydrogenation to methane in imidazolium-based ionic liquid media, using ruthenium nanoparticles prepared in situ as catalyst. The best yield of methane (69 %) was achieved using 0.24 mol % ruthenium catalyst (in [omim][NTf2 ], 1-octyl-3-methylimidazolium bistrifluoromethanesulfonylimide, at 40 bar of hydrogen pressure plus 40 bar of CO2 pressure, and at 150 °C. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A ruthenium-based biomimetic hydrogen cluster for efficient photocatalytic hydrogen generation from formic acid.

    PubMed

    Chang, Chin-Hao; Chen, Mei-Hua; Du, Wan-Shan; Gliniak, Jacek; Lin, Jia-Hoa; Wu, Hsin-Hua; Chan, Hsin-Fang; Yu, Jen-Shiang K; Wu, Tung-Kung

    2015-04-20

    A ruthenium-based biomimetic hydrogen cluster, [Ru2 (CO)6 (μ-SCH2 CH2 CH2 S)] (1), has been synthesized and, in the presence of the P ligand tri(o-tolyl)phosphine, demonstrated efficient photocatalytic hydrogen generation from formic acid decomposition. Turnover frequencies (TOFs) of 5500 h(-1) and turnover numbers (TONs) over 24 700 were obtained with less than 50 ppm of the catalyst, thus representing the highest TOFs for ruthenium complexes as well as the best efficiency for photocatalytic hydrogen production from formic acid. Moreover, 1 showed high stability with no significant degradation of the photocatalyst observed after prolonged photoirradiation at 90 °C.

  20. Bis(Cyclic Alkyl Amino Carbene) Ruthenium Complexes: A Versatile, Highly Efficient Tool for Olefin Metathesis.

    PubMed

    Gawin, Rafał; Kozakiewicz, Anna; Guńka, Piotr A; Dąbrowski, Paweł; Skowerski, Krzysztof

    2017-01-19

    The state-of-the-art in olefin metathesis is application of N-heterocyclic carbene (NHC)-containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)-containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported.

  1. Enantiotopos-selective C-H oxygenation catalyzed by a supramolecular ruthenium complex.

    PubMed

    Frost, James R; Huber, Stefan M; Breitenlechner, Stefan; Bannwarth, Christoph; Bach, Thorsten

    2015-01-07

    Spirocyclic oxindoles undergo an enantioselective oxygenation reaction (nine examples; e.r. up to 97:3) upon catalysis by a chiral ruthenium porphyrin complex (1 mol %). The catalyst exhibits a lactam ring, which is responsible for substrate association through hydrogen bonds, and an active ruthenium center, which is in a defined spatial relationship to the oxygenation substrate. DFT calculations illustrate the perfect alignment of the active site with the reactive C-H bond and suggest--in line with the kinetic isotope effect--an oxygen rebound mechanism for the reaction.

  2. Selective ruthenium labeling of the tryptophan residue in the bee venom Peptide melittin.

    PubMed

    Perekalin, Dmitry S; Novikov, Valentin V; Pavlov, Alexander A; Ivanov, Igor A; Anisimova, Natalia Yu; Kopylov, Alexey N; Volkov, Dmitry S; Seregina, Irina F; Bolshov, Michail A; Kudinov, Alexander R

    2015-03-23

    Melittin is a membrane-active peptide from bee venom with promising antimicrobial and anticancer activity. Herein we report on a simple and selective method for labeling of the tryptophan residue in melittin by the organometallic fragment [(C5 H5 )Ru](+) in aqueous solution and in air. Ruthenium coordination does not disturb the secondary structure of the peptide (as verified by 2D NMR spectroscopy), but changes the pattern of its intermolecular interactions resulting in an 11-fold decrease of hemolytic activity. The high stability of the organometallic conjugate allowed the establishment of the biodistribution of the labeled melittin in mice by inductively coupled plasma MS analysis of ruthenium.

  3. Ruthenium(II)-catalyzed oxidative C-H alkenylations of sulfonic acids, sulfonyl chlorides and sulfonamides.

    PubMed

    Ma, Wenbo; Mei, Ruhuai; Tenti, Giammarco; Ackermann, Lutz

    2014-11-10

    Twofold C-H functionalization of aromatic sulfonic acids was achieved with an in situ generated ruthenium(II) catalyst. The optimized cross-dehydrogenative alkenylation protocol proved applicable to differently substituted arenes and a variety of alkenes, including vinyl arenes, sulfones, nitriles and ketones. The robustness of the ruthenium(II) catalyst was demonstrated by the chemoselective oxidative olefination of sulfonamides as well as sulfonyl chlorides. Mechanistic studies provided support for a reversible, acetate-assisted C-H ruthenation, along with a subsequent olefin insertion.

  4. Thermochemistry and Molecular Structure of a Remarkable Agostic Interaction in a Heterobifunctional Ruthenium-Boron Complex

    PubMed Central

    Conley, Brian L.; Williams, Travis J.

    2010-01-01

    A boron-pendant ruthenium species forms a unique agostic methyl bridge between the boron and ruthenium atoms in the presence of a ligating solvent, acetonitrile. NMR inversion-recovery experiments enable measurement of the activation and equilibrium thermochemistry for formation of the agostic bridge. The mechanism for bridge formation involves displacement of an acetonitrile ligand; thus, this is a rare example of a case where an agostic C—H ligand competitively displaces another tight-binding ligand from a coordinatively saturated complex. Characterization of this complex gives unique insights into development of C—H activation catalysis based on this ligand-metal bifunctional motif. PMID:20088526

  5. Proton-coupled electron transfer and multielectron oxidations in complexes of ruthenium and osmium

    SciTech Connect

    Dovletoglou, A.

    1992-01-01

    This doctoral research concerns the mechanism of proton-coupled electron transfer over an extended pH range. These processes between ruthenium and osmium complexes and hydroquinones have been studied using spectrophotometric methods and cyclic voltammetry. Elucidation of the mechanistic details has been attempted by using isotopic labelling, kinetic analysis, and numerical simulation of complex kinetic schemes. The coordination and redox chemistry of polypyridyl-acetylacetonato and -oxalato complexes of ruthenium and the role of ancillary ligands in defining the properties of Ru[sup IV]O complexes were explored. These studies represent the first attempt to probe possible 2e[sup [minus

  6. Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

    PubMed Central

    Collman, James P.; McDevitt, John T.; Yee, Gordon T.; Leidner, Charles R.; McCullough, Laughlin G.; Little, William A.; Torrance, Jerry B.

    1986-01-01

    The synthesis and characterization of pyrazine-bridged polymers of iron(II/III), ruthenium(II/III), and osmium(II/III) octaethylporphyrin (dubbed “shish-kebab” polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polymers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway. Unlike most of the previously reported porphyrinic molecular metals in which the conduction electrons are macrocyclic-based, electron transport in these materials proceeds exclusively along the metal-pyrazine backbone. PMID:16593717

  7. ECL performance of ruthenium tris-bipyridyl complexes covalently linked with phenothiazine through different bridge.

    PubMed

    Sun, Shiguo; Yang, Yang; Liu, Fengyu; Fan, Jiangli; Kehr, Jan; Sun, Licheng; Peng, Xiaojun

    2010-10-07

    Three ruthenium complexes 1a, 1b and 1c were synthesized, in which the phenothiazine moiety was covalently linked to the ruthenium complex through a 4 carbon chain and amide bond, respectively. The results demonstrate that one PTZ moiety is preferred to reach a good ECL performance, and the 4 carbon chain linked complex 1a exhibits the highest ECL enhancement (up to about 9 times), in comparison with the commonly utilized parent Ru(bpy)(3)(2+), permitting a lower detection limit of 1.0 x 10(-14) M with signal to noise of 3 for 20 mM DBAE at Au electrode.

  8. Formation of C-C bonds via ruthenium-catalyzed transfer hydrogenation().

    PubMed

    Moran, Joseph; Krische, Michael J

    2012-01-01

    Ruthenium-catalyzed transfer hydrogenation of diverse π-unsaturated reactants in the presence of aldehydes provides products of carbonyl addition. Dehydrogenation of primary alcohols in the presence of the same π-unsaturated reactants provides identical products of carbonyl addition. In this way, carbonyl addition is achieved from the alcohol or aldehyde oxidation level in the absence of stoichiometric organometallic reagents or metallic reductants. In this account, the discovery of ruthenium-catalyzed C-C bond-forming transfer hydrogenations and the recent development of diastereo- and enantioselective variants are discussed.

  9. Mo99 Production Plant Layout

    SciTech Connect

    Woloshun, Keith Albert; Dale, Gregory E.; Naranjo, Angela Carol

    2015-06-25

    The NorthStar Medical Technologies 99Mo production facility configuration is envisioned to be 8 accelerator pairs irradiating 7 100Mo targets (one spare accelerator pair undergoing maintenance while the other 7 pairs are irradiating targets). The required shielding in every direction for the accelerators is initially estimated to be 10 feet of concrete. With the accelerator pairs on one (ground) level and spaced with the required shielding between adjacent pairs, the only practical path for target insertion and removal while minimizing floor space is vertical. The current scheme then requires a target vertical lift of nominally 10 feet through a shield stack. It is envisioned that the lift will be directly into a hot cell where an activated target can be removed from its holder and a new target attached and lowered. The hot cell is on a rail system so that a single hot cell can service all active target locations, as well as deliver the ready targets to the separations lab. On this rail system, coupled to the hot cell, will be a helium recovery and clean-up system. All helium coolant equipment is located on the upper level near to the target removal point.

  10. STS-99 / Endeavour Mission Overview

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM). This radar system will produce unrivaled 3-D images of the Earth's Surface. This videotape presents a mission overview press briefing. The panel members are Dr. Ghassem Asrar, NASA Associate Administrator Earth Sciences; General James C. King, Director National Imagery and Mapping Agency (NIMA); Professor Achim Bachem, Member of the Executive Board, Deutschen Zentrum fur Luft- und Raumfahrt (DLR), the German National Aerospace Research Center; and Professor Sergio Deiulio, President of the Italian Space Agency. Dr. Asrar opened with a summary of the history of Earth Observations from space, relating the SRTM to this history. This mission, due to cost and complexity, required partnership with other agencies and nations, and the active participation of the astronauts. General King spoke to the expectations of NIMA, and the use of the Synthetic Aperture Radar to produce the high resolution topographic images. Dr. Achim Bachem spoke about the international cooperation that this mission required, and some of the commercial applications and companies that will use this data. Dr Deiulio spoke of future plans to improve knowledge of the Earth using satellites. Questions from the press concerned use of the information for military actions, the reason for the restriction on access to the higher resolution data, the mechanism to acquire that data for scientific research, and the cost sharing from the mission's partners. There was also discussion about the mission's length.

  11. STS-99 Prelaunch Press Briefing

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour, and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This videotape shows a press briefing about a mechanical problem that the shuttle was having. There was discussion about possibly scrubbing the launch due to the problem with the Enhanced Master Events Controller. A problem with a fuel pump part had also become evident and there was discussion about the impact that this could have on the flight.

  12. LIDAR Measurements During Aerosols99

    NASA Technical Reports Server (NTRS)

    Voss, Kenneth J.; Welton, Ellsworth J.; Quinn, Patricia K.; Johnson, James; Thompson, Anne; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The Aerosols99 cruise took place during the period from January 14, to February 8 1999 on the R/V Ron Brown. The cruise track was almost a straight line from Norfolk, Va. to Cape Town, South Africa and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. A Micro Pulse LIDAR system was used continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres the aerosols were capped at 1 km. When a Dust event from Africa was encountered the aerosol extinction increased its maximum height to above 2 km. During a period in which the air mass was dominated by biomass burning from Southern Africa, the aerosol layer extended to 4 km. Comparisons of the aerosol optical depth derived from LIDAR inversion and surface sunphotometers showed an agreement within +/- 0.05 RMS Similar comparisons between the extinction measured with a nephelometer and particle soot absorption photometer (at 19 m altitude) and the lowest LIDAR measurement (75 m) showed good agreement (+/- 0.014/km . The LIDAR underestimated surface extinction during periods when an elevated aerosol layer was present over a relatively clean surface layer, but otherwise gave accurate results.

  13. Characterization of ruthenium red-binding sites of the Ca(2+)-ATPase from sarcoplasmic reticulum and their interaction with Ca(2+)-binding sites.

    PubMed Central

    Corbalan-Garcia, S; Teruel, J A; Gomez-Fernandez, J C

    1992-01-01

    Sarcoplasmic reticulum Ca(2+)-ATPase has previously been shown to bind and dissociate two Ca2+ ions in a sequential mode. This behaviour is confirmed here by inducing sequential Ca2+ dissociation with Ruthenium Red. Ruthenium Red binds to sarcoplasmic reticulum vesicles (6 nmol/mg) with a Kd = 2 microM, producing biphasic kinetics of Ca2+ dissociation from the Ca(2+)-ATPase, decreasing the affinity for Ca2+ binding. Studies on the effect of Ca2+ on Ruthenium Red binding indicate that Ruthenium Red does not bind to the high-affinity Ca(2+)-binding sites, as suggested by the following observations: (i) micromolar concentrations of Ca2+ do not significantly alter Ruthenium Red binding to the sarcoplasmic reticulum; (ii) quenching of the fluorescence of fluorescein 5'-isothiocyanate (FITC) bound to Ca(2+)-ATPase by Ruthenium Red (resembling Ruthenium Red binding) is not prevented by micromolar concentrations of Ca2+; (iii) quenching of FITC fluorescence by Ca2+ binding to the high-affinity sites is achieved even though Ruthenium Red is bound to the Ca(2+)-ATPase; and (iv) micromolar Ca2+ concentrations prevent inhibition of the ATP-hydrolytic capability by dicyclohexylcarbodi-imide modification, but Ruthenium Red does not. However, micromolar concentrations of lanthanides (La3+ and Tb3+) and millimolar concentrations of bivalent cations (Ca2+ and Mg2+) inhibit Ruthenium Red binding as well as quenching of FITC-labelled Ca(2+)-ATPase fluorescence by Ruthenium Red. Studies of Ruthenium Red binding to tryptic fragments of Ca(2+)-ATPase, as demonstrated by ligand blotting, indicate that Ruthenium Red does not bind to the A1 subfragment. Our observations suggest that Ruthenium Red might bind to a cation-binding site in Ca(2+)-ATPase inducing fast release of the last bound Ca2+ by interactions between the sites. PMID:1280106

  14. Cyclotron Production of Technetium-99m

    NASA Astrophysics Data System (ADS)

    Gagnon, Katherine M.

    Technetium-99m (99mTc) has emerged as the most widely used radionuclide in medicine and is currently obtained from a 99Mo/ 99mTc generator system. At present, there are only a handful of ageing reactors worldwide capable of producing large quantities of the parent isotope, 99Mo, and owing to the ever growing shutdown periods for maintenance and repair of these ageing reactors, the reliable supply 99mTc has been compromised in recent years. With an interest in alternative strategies for producing this key medical isotope, this thesis focuses on several technical challenges related to the direct cyclotron production of 99mTc via the 100Mo(p,2n)99mTc reaction. In addition to evaluating the 100Mo(p,2n)99mTc and 100Mo(p,x)99Mo reactions, this work presented the first experimental evaluation of the 100Mo(p,2n) 99gTc excitation function in the range of 8-18 MeV. Thick target calculations suggested that large quantities of cyclotron-produced 99mTc may be possible. For example, a 6 hr irradiation at 500 μA with an energy window of 18→10 MeV is expected to yield 1.15 TBq of 99mTc. The level of coproduced 99gTc contaminant was found to be on par with the current 99Mo/99mTc generator standard eluted with a 24 hr frequency. Highly enriched 100Mo was required as the target material for 99mTc production and a process for recycling of this expensive material is presented. An 87% recovery yield is reported, including metallic target preparation, irradiation, 99mTc extraction, molybdate isolation, and finally hydrogen reduction to the metal. Further improvements are expected with additional optimization experiments. A method for forming structurally stable metallic molybdenum targets has also been developed. These targets are capable of withstanding more than a kilowatt of beam power and the reliable production and extraction of Curie quantities of 99mTc has been demonstrated. With the end-goal of using the cyclotron-produced 99mTc clinically, the quality of the cyclotron

  15. Photoexpulsion of Surface-Grafted Ruthenium Complexes and Subsequent Release of Cytotoxic Cargos to Cancer Cells from Mesoporous Silica Nanoparticles

    PubMed Central

    Frasconi, Marco; Liu, Zhichang; Lei, Juying; Wu, Yilei; Strekalova, Elena; Malin, Dmitry; Ambrogio, Michael W.; Chen, Xinqi; Botros, Youssry Y.; Cryns, Vincent L.; Sauvage, Jean-Pierre; Stoddart, J. Fraser

    2014-01-01

    Ruthenium(II) polypyridyl complexes have emerged both as promising probes of DNA structure and as anticancer agents because of their unique photophysical and cytotoxic properties. A key consideration in the administration of those therapeutic agents is the optimization of their chemical reactivities to allow facile attack on the target sites, yet avoid unwanted side effects. Here, we present a drug delivery platform technology, obtained by grafting the surface of mesoporous silica nanoparticles (MSNPs) with ruthenium(II) dipyridophenazine (dppz) complexes. This hybrid nanomaterial displays enhanced luminescent properties relative to that of the ruthenium(II) dppz complex in a homogeneous phase. Since the coordination between the ruthenium(II) complex and a monodentate ligand linked covalently to the nanoparticles can be cleaved under irradiation with visible light, the ruthenium complex can be released from the surface of the nanoparticles by selective substitution of this ligand with a water molecule. Indeed, the modified MSNPs undergo rapid cellular uptake, and after activation with light, the release of an aqua ruthenium(II) complex is observed. We have delivered, in combination, the ruthenium(II) complex and paclitaxel, loaded in the mesoporous structure, to breast cancer cells. This hybrid material represents a promising candidate as one of the so-called theranostic agents that possess both diagnostic and therapeutic functions. PMID:23815127

  16. Cytotoxic and genotoxic effects of cis-tetraammine(oxalato)ruthenium(III) dithionate on the root meristem cells of Allium cepa.

    PubMed

    Pereira, Flávia de Castro; Vilanova-Costa, Cesar Augusto Sam Tiago; de Lima, Aliny Pereira; Ribeiro, Alessandra de Santana Braga Barbosa; da Silva, Hugo Delleon; Pavanin, Luiz Alfredo; Silveira-Lacerda, Elisângela de Paula

    2009-06-01

    Ruthenium complexes have attracted much attention as possible building blocks for new transition-metal-based antitumor agents. The present study examines the mitotoxic and clastogenic effects induced in the root tips of Allium cepa by cis-tetraammine(oxalato)ruthenium(III) dithionate {cis-[Ru(C(2)O(2))(NH(3))(4)](2)(S(2)O(6))} at different exposure durations and concentrations. Correlation tests were performed to determine the effects of the time of exposure and concentration of ruthenium complex on mitotic index (MI) and mitotic aberration index. A comparison of MI results of cis-[Ru(C(2)O(2))(NH(3))(4)](2)(S(2)O(6)) to those of lead nitrate reveals that the ruthenium complex demonstrates an average mitotic inhibition eightfold higher than lead, with the frequency of cellular abnormalities almost fourfold lower and mitotic aberration threefold lower. A. cepa root cells exposed to a range of ruthenium complex concentrations did not display significant clastogenic effects. Cis-tetraammine(oxalato)ruthenium(III) dithionate therefore exhibits a remarkable capacity to inhibit mitosis, perhaps by inhibiting DNA synthesis or blocking the cell cycle in the G2 phase. Further investigation of the mechanisms of action of this ruthenium complex will be important to define its clinical potential and to contribute to a novel and rational approach to developing a new metal-based drug with antitumor properties complementary to those exhibited by the drugs already in clinical use.

  17. Catalytic water oxidation by ruthenium(II) quaterpyridine (qpy) complexes: evidence for ruthenium(III) qpy-N,N'''-dioxide as the real catalysts.

    PubMed

    Liu, Yingying; Ng, Siu-Mui; Yiu, Shek-Man; Lam, William W Y; Wei, Xi-Guang; Lau, Kai-Chung; Lau, Tai-Chu

    2014-12-22

    Polypyridyl and related ligands have been widely used for the development of water oxidation catalysts. Supposedly these ligands are oxidation-resistant and can stabilize high-oxidation-state intermediates. In this work a series of ruthenium(II) complexes [Ru(qpy)(L)2 ](2+) (qpy=2,2':6',2'':6'',2'''-quaterpyridine; L=substituted pyridine) have been synthesized and found to catalyze Ce(IV) -driven water oxidation, with turnover numbers of up to 2100. However, these ruthenium complexes are found to function only as precatalysts; first, they have to be oxidized to the qpy-N,N'''-dioxide (ONNO) complexes [Ru(ONNO)(L)2 ](3+) which are the real catalysts for water oxidation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Pulsed Nd:YAG laser deposition of ruthenium thin films

    NASA Astrophysics Data System (ADS)

    Wai Keat, Lee

    Ruthenium (Ru) is one of the noble air-stable transition metals, which has excellent thermal chemical stability, low electrical resistivity, and relatively high work function near the valence band edge of Si. Recently, Ru has been introduced into the semiconductor industries as a result of the interesting chemical, physical, and electrical properties it possessed. So far, investigations of ruthenium films have been centered on material properties of Ru layers, growth using direct current/radiofrequency (DC/RF) magnetron sputtering, and chemical vapor deposition. However, comparatively little work has been carried out using the pulsed laser deposition (PLD) technique. In this research work, the growth of Ru film using PLD was investigated. The Ru films were deposited on silicon (Si) substrates employing 355 nm pulsed Nd:YAG laser source. Laser fluence ranged from 2 to 8 J/cm2 was employed, with deposition duration from 5 to 180 minutes under high vacuum condition. Optical emission spectroscopy (OES) was employed to study the species and purity of the plasma during the deposition. It was observed that intensity of the Ru species spectra increased with increasing laser fluence and more prominent after laser fluence of 4 J/cm2. No impurities were observed. Film thicknesses ranging from 15 to 280 nm were obtained. As the deposition duration and the laser fluence increased, the thickness of the deposited Ru films increased. It is observed that there was a critical deposition duration value, and this value increases as the laser fluence increased. X-ray diffraction (XRD) spectra showed Ru with crystalline orientation of (101), (100), and (002) peaks. The XRD results revealed an enhanced diffraction peak when film thickness increased, under all laser fluences. Grain sizes were deduced from the XRD data by using the Scherrer's formula and the values fall in the range of 20 to 35 nm for the film thickness covering from 50 nm to 250 nm. Besides, the electrical properties of

  19. In vitro evaluation of ruthenium complexes for photodynamic therapy.

    PubMed

    Li, Wenna; Xie, Qiang; Lai, Linglin; Mo, Zhentao; Peng, Xiaofang; Leng, Ennian; Zhang, Dandan; Sun, Hongxia; Li, Yiqi; Mei, Wenjie; Gao, Shuying

    2017-06-01

    Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. Rup-03 and Rup-04 had the lowest IC50 values. Rup-03 had an IC50 value of 29.5±2.3μM in HepG2 cells and 59.0±6.1μM in RAW264.7 cells, while Rup-04 had an IC50 value of 40.0±3.8μM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Ruthenium porphyrin-induced photodamage in bladder cancer cells.

    PubMed

    Bogoeva, Vanya; Siksjø, Monica; Sæterbø, Kristin G; Melø, Thor Bernt; Bjørkøy, Astrid; Lindgren, Mikael; Gederaas, Odrun A

    2016-06-01

    Photodynamic therapy (PDT) is a noninvasive treatment for solid malignant and flat tumors. Light activated sensitizers catalyze photochemical reactions that produce reactive oxygen species which can cause cancer cell death. In this work we investigated the photophysical properties of the photosensitizer ruthenium(II) porphyrin (RuP), along with its PDT efficiency onto rat bladder cancer cells (AY27). Optical spectroscopy verified that RuP is capable to activate singlet oxygen via blue and red absorption bands and inter system crossing (ISC) to the triplet state. In vitro experiments on AY27 indicated increased photo-toxicity of RuP (20μM, 18h incubation) after cell illumination (at 435nm), as a function of blue light exposure. Cell survival fraction was significantly reduced to 14% after illumination of 20μM RuP with 15.6J/cm(2), whereas the "dark toxicity" of 20μM RuP was 17%. Structural and morphological changes of cells were observed, due to RuP accumulation, as well as light-dependent cell death was recorded by confocal microscopy. Flow cytometry verified that PDT-RuP (50μM) triggered significant photo-induced cellular destruction with a photoxicity of (93%±0.9%). Interestingly, the present investigation of RuP-PDT showed that the dominating mode of cell death is necrosis. RuP "dark toxicity" compared to the conventional chemotherapeutic drug cisplatin was higher, both evaluated by the MTT assay (24h). In conclusion, the present investigation shows that RuP with or without photoactivation induces cell death of bladder cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. {sup 106}Ruthenium Plaque Therapy (RPT) for Retinoblastoma

    SciTech Connect

    Murakami, Naoya; Suzuki, Shigenobu; Ito, Yoshinori; Yoshimura, Ryoichi; Inaba, Koji; Kuroda, Yuki; Morota, Madoka; Mayahara, Hiroshi; Sakudo, Mototake; Wakita, Akihisa; Okamoto, Hiroyuki; Sumi, Minako; Kagami, Yoshikazu; Nakagawa, Keiichi; Ohtomo, Kuni; Itami, Jun

    2012-09-01

    Purpose: To evaluate the effectiveness of episcleral {sup 106}ruthenium plaque therapy (RPT) in the management of retinoblastoma. Methods and Materials: One hundred one RPTs were retrospectively analyzed that were performed in 90 eyes of 85 patients with retinoblastoma at National Cancer Center Hospital between 1998 and 2008. Each RPT had a corresponding tumor and 101 tumors were considered in the analysis of local control. Median follow-up length was 72.8 months. Median patient age at the RPT was 28 months. Median prescribed doses at reference depth and outer surface of the sclera were 47.4 Gy and 162.3 Gy, respectively. Results: Local control rate (LCR) and ocular retention rate (ORR) at 2 years were 33.7% and 58.7%, respectively. Unilateral disease, International Classification of Retinoblastoma group C or more advanced at the first presentation or at the time of RPT, vitreous and/or subretinal seeding, tumor size greater than 5 disc diameter (DD), reference depth greater than 5 mm, dose rate at reference depth lower than 0.7 Gy/hour, dose at the reference depth lower than 35 Gy, and (biologically effective dose with an {alpha}/{beta} ratio of 10 Gy) at the reference depth lower than 40 Gy{sub 10} were associated with unfavorable LCR. Two patients died of metastatic disease. Radiation complications included retinal detachment in 12 eyes (13.3%), proliferative retinopathy in 6 (6.7%), rubeosis iris in 2 (2.2%), and posterior subcapsular cataract in 23 (25.6%). Conclusion: RPT is an effective eye-preserving treatment for retinoblastoma.

  2. Regression of Lung Cancer by Hypoxia Sensitizing Ruthenium Polypyridyl Complexes

    PubMed Central

    Yadav, Abhishek; Janaratne, Thamara; Krishnan, Arthi; Singhal, Sharad S.; Yadav, Sushma; Dayoub, Adam S.; Hawkins, Doyle L.; Awasthi, Sanjay; MacDonnell, Frederick M.

    2013-01-01

    The ruthenium (II) polypyridyl complexes (RPCs) Δ-[(phen)2Ru(tatpp)]Cl2 (Δ-[3]Cl2) and ΔΔ-[(phen)2Ru(tatpp)Ru(phen)2]Cl4 (ΔΔ-[4]Cl4) are a new generation of metal-based anti-tumor agents. These RPCs bind DNA via intercalation of the tatpp ligand which itself is redox-active and easily reduced at biologically relevant potentials. We have previously shown that RPC 44+ cleaves DNA when reduced by glutathione to a radical species, and that this DNA cleavage is potentiated under hypoxic conditions in vitro. Here we show that 32+ also exhibits free-radical mediated DNA cleavage in vitro, and that 32+ and 44+ both exhibit selective cytotoxicity towards cultured malignant cell lines, and marked inhibition of tumor growth in vivo. The murine acute toxicity of RPCs 32+ and 44+ (maximum tolerable doses (MTD’s) ~ 65 µmol/kg) is comparable with that for cisplatin (LD50 ~57 µmol/kg) but unlike cisplatin, RPC’s are generally cleared from the body unchanged via renal excretion without appreciable metabolism or nephrotoxic side effects. RPCs 32+ and 44+ are demonstrated to suppress growth of human non-small cell lung carcinoma (~83%), show potentiated cytotoxicity in vitro under hypoxic conditions, and induce apoptosis through both intrinsic and extrinsic pathways. The novel hypoxia-enhanced DNA cleavage activity and biological activity suggest a promising new anti-cancer pharmacophore based on metal complexes with aromatic ligands that are easily reduced at biologically accessible potentials. PMID:23443803

  3. Dealloyed Ruthenium Film Catalysts for Hydrogen Generation from Chemical Hydrides

    PubMed Central

    Serin, Ramis B.; Abdullayeva, Nazrin; Sankir, Mehmet

    2017-01-01

    Thin-film ruthenium (Ru) and copper (Cu) binary alloys have been prepared on a Teflon™ backing layer by cosputtering of the precious and nonprecious metals, respectively. Alloys were then selectively dealloyed by sulfuric acid as an etchant, and their hydrogen generation catalysts performances were evaluated. Sputtering time and power of Cu atoms have been varied in order to tailor the hydrogen generation performances. Similarly, dealloying time and the sulfuric acid concentration have also been altered to tune the morphologies of the resulted films. A maximum hydrogen generation rate of 35 mL min−1 was achieved when Cu sputtering power and time were 200 W and 60 min and while acid concentration and dealloying time were 18 M and 90 min, respectively. It has also been demonstrated that the Ru content in the alloy after dealloying gradually increased with the increasing the sputtering power of Cu. After 90 min dealloying, the Ru to Cu ratio increased to about 190 times that of bare alloy. This is the key issue for observing higher catalytic activity. Interestingly, we have also presented template-free nanoforest-like structure formation within the context of one-step alloying and dealloying used in this study. Last but not least, the long-time hydrogen generation performances of the catalysts system have also been evaluated along 3600 min. During the first 600 min, the catalytic activity was quite stable, while about 24% of the catalytic activity decayed after 3000 min, which still makes these systems available for the development of robust catalyst systems in the area of hydrogen generation. PMID:28773097

  4. Dealloyed Ruthenium Film Catalysts for Hydrogen Generation from Chemical Hydrides.

    PubMed

    Serin, Ramis B; Abdullayeva, Nazrin; Sankir, Mehmet

    2017-07-02

    Thin-film ruthenium (Ru) and copper (Cu) binary alloys have been prepared on a Teflon™ backing layer by cosputtering of the precious and nonprecious metals, respectively. Alloys were then selectively dealloyed by sulfuric acid as an etchant, and their hydrogen generation catalysts performances were evaluated. Sputtering time and power of Cu atoms have been varied in order to tailor the hydrogen generation performances. Similarly, dealloying time and the sulfuric acid concentration have also been altered to tune the morphologies of the resulted films. A maximum hydrogen generation rate of 35 mL min(-1) was achieved when Cu sputtering power and time were 200 W and 60 min and while acid concentration and dealloying time were 18 M and 90 min, respectively. It has also been demonstrated that the Ru content in the alloy after dealloying gradually increased with the increasing the sputtering power of Cu. After 90 min dealloying, the Ru to Cu ratio increased to about 190 times that of bare alloy. This is the key issue for observing higher catalytic activity. Interestingly, we have also presented template-free nanoforest-like structure formation within the context of one-step alloying and dealloying used in this study. Last but not least, the long-time hydrogen generation performances of the catalysts system have also been evaluated along 3600 min. During the first 600 min, the catalytic activity was quite stable, while about 24% of the catalytic activity decayed after 3000 min, which still makes these systems available for the development of robust catalyst systems in the area of hydrogen generation.

  5. Metalloporphyrin-mediated asymmetric nitrogen-atom transfer to hydrocarbons: aziridination of alkenes and amidation of saturated C-H bonds catalyzed by chiral ruthenium and manganese porphyrins.

    PubMed

    Liang, Jiang-Lin; Huang, Jie-Sheng; Yu, Xiao-Qi; Zhu, Nianyong; Che, Chi-Ming

    2002-04-02

    Chiral metalloporphyrins [Mn(Por*)(OH)(MeOH)] (1) and [Ru(Por*)(CO)(EtOH)] (2) catalyze asymmetric aziridination of aromatic alkenes and asymmetric amidation of benzylic hydrocarbons to give moderate enantiomeric excesses. The mass balance in these nitrogen-atom-transfer processes has been examined. With PhI=NTs as the nitrogen source, the aziridination of styrenes, trans-stilbene, 2-vinylnaphthalene, indene, and 2,2-dimethylchromene catalyzed by complex 1 or 2 resulted in up to 99 % substrate conversions and up to 94 % aziridine selectivities, whereas the amidation of ethylbenzenes, indan, tetralin, 1-, and 2-ethylnaphthalene catalyzed by complex 2 led to substrate conversions of up to 32 % and amide selectivities of up to 91 %. Complex 1 or 2 can also catalyze the asymmetric amidation of 4-methoxyethylbenzene, tetralin, and 2-ethylnaphthalene with "PhI(OAc)(2) + NH(2)SO(2)Me", affording the N-substituted methanesulfonamides in up to 56 % ee with substrate conversions of up to 34 % and amide selectivities of up to 92 %. Extension of the "complex 1 + PhI=NTs" or "complex 1 + PhI(OAc)(2) + NH(2)R (R=Ts, Ns)" amidation protocol to a steroid resulted in diastereoselective amidation of cholesteryl acetate at the allylic C-H bonds at C-7 with substrate conversions of up to 49 % and amide selectivities of up to 90 % (alpha:beta ratio: up to 4.2:1). An aziridination- and amidation-active chiral bis(tosylimido)ruthenium(VI) porphyrin, [Ru(Por*)(NTs)(2)] (3), and a ruthenium porphyrin aziridine adduct, [Ru(Por*)(CO)(TsAz)] (4, TsAz=N-tosyl-2- (4-chlorophenyl)aziridine), have been isolated from the reaction of 2 with PhI=NTs and N-tosyl-2-(4-chlorophenyl)aziridine, respectively. The imidoruthenium porphyrin 3 could be an active species in the aziridination or amidation catalyzed by complex 2 described above. The second-order rate constants for the reactions of 3 with styrenes, 2-vinylnaphthalene, indene, ethylbenzenes, and 2-ethylnaphthalene range from 3.7-42.5x10(-3) dm(3

  6. A combined experimental and computational study on the cycloisomerization of 2-ethynylbiaryls catalyzed by dicationic arene ruthenium complexes.

    PubMed

    Yamamoto, Yoshihiko; Matsui, Kazuma; Shibuya, Masatoshi

    2015-05-04

    Ruthenium-catalyzed cycloisomerization of 2-ethynylbiaryls was investigated to identify an optimal ruthenium catalyst system. A combination of [η(6) -(p-cymene)RuCl2 (PR3 )] and two equivalents of AgPF6 effectively converted 2-ethynylbiphenyls into phenanthrenes in chlorobenzene at 120 °C over 20 h. Moreover, 2-ethynylheterobiaryls were found to be favorable substrates for this ruthenium catalysis, thus achieving the cycloisomerization of previously unused heterocyclic substrates. Moreover, several control experiments and DFT calculations of model complexes were performed to propose a plausible reaction mechanism. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Amidines for versatile ruthenium(II)-catalyzed oxidative C-H activations with internal alkynes and acrylates.

    PubMed

    Li, Jie; John, Michael; Ackermann, Lutz

    2014-04-25

    Cationic ruthenium complexes derived from KPF6 or AgOAc enabled efficient oxidative CH functionalizations on aryl and heteroaryl amidines. Thus, oxidative annulations of diversely decorated internal alkynes provided expedient access to 1-aminoisoquinolines, while catalyzed C-H activations with substituted acrylates gave rise to structurally novel 1-iminoisoindolines. The powerful ruthenium(II) catalysts displayed a remarkably high site-, regio- and, chemoselectivity. Therefore, the catalytic system proved tolerant of a variety of important electrophilic functional groups. Detailed mechanistic studies provided strong support for the cationic ruthenium(II) catalysts to operate by a facile, reversible C-H activation.

  8. Radiation Chemistry of Simulated (99)Mo Product

    SciTech Connect

    Carson, S.D.; Garcia, M.J.; McDonald, M.J.; Simpson, R.L.; Tallant, D.R.

    1998-11-06

    PharrnaceuticaI houses that produce {sup 99}Tc/{sup 99}Tc generators have on occasion received {sup 99}Mo that contained a black precipitate. Addition of sodium hypochlorite to product bottles prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of Mo. The radiation effects of the dose from {sup 99}Mo on the product and product bottle have been determined by irradiating simulated {sup 99}Mo product solutions with the {sup 60}Co source at Sandia National Laboratories' Gamma Irradiation Facility (GE). The GIF experiment successfully generated a black precipitate in amounts sufficient for isolation and analysis by infrared and Rrunan spectroscopy. Changes in the pH of the basic {sup 99}Mo product solution during irradiation were monitored by titration. ResuIts of these analyses and the nature of the process that generates the precipitate, a mixture of molybdenum oxides that forms in plastic bottles, but not in glass containers, are discussed.

  9. 21 CFR 12.99 - Motions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Motions. 12.99 Section 12.99 Food and Drugs FOOD... HEARING Hearing Procedures § 12.99 Motions. (a) A motion on any matter relating to the proceeding is to be... before the presiding officer. (b) A response may be filed within 10 days of service of a motion. The time...

  10. 21 CFR 12.99 - Motions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Motions. 12.99 Section 12.99 Food and Drugs FOOD... HEARING Hearing Procedures § 12.99 Motions. (a) A motion on any matter relating to the proceeding is to be... before the presiding officer. (b) A response may be filed within 10 days of service of a motion. The time...

  11. 21 CFR 12.99 - Motions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Motions. 12.99 Section 12.99 Food and Drugs FOOD... HEARING Hearing Procedures § 12.99 Motions. (a) A motion on any matter relating to the proceeding is to be... before the presiding officer. (b) A response may be filed within 10 days of service of a motion. The time...

  12. 21 CFR 12.99 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Motions. 12.99 Section 12.99 Food and Drugs FOOD... HEARING Hearing Procedures § 12.99 Motions. (a) A motion on any matter relating to the proceeding is to be... before the presiding officer. (b) A response may be filed within 10 days of service of a motion. The time...

  13. 21 CFR 12.99 - Motions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Motions. 12.99 Section 12.99 Food and Drugs FOOD... HEARING Hearing Procedures § 12.99 Motions. (a) A motion on any matter relating to the proceeding is to be... before the presiding officer. (b) A response may be filed within 10 days of service of a motion. The time...

  14. 31 CFR 9.9 - Report.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Report. 9.9 Section 9.9 Money and... SECURITY § 9.9 Report. A report will be made and published in the Federal Register upon the disposition of each request, application or motion under § 9.3. Copies of the report will be available at the Office...

  15. 31 CFR 9.9 - Report.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Report. 9.9 Section 9.9 Money and... SECURITY § 9.9 Report. A report will be made and published in the Federal Register upon the disposition of each request, application or motion under § 9.3. Copies of the report will be available at the Office...

  16. 31 CFR 9.9 - Report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Report. 9.9 Section 9.9 Money and... SECURITY § 9.9 Report. A report will be made and published in the Federal Register upon the disposition of each request, application or motion under § 9.3. Copies of the report will be available at the Office...

  17. SEPARATION OF URANYL AND RUTHENIUM VALUES BY THE TRIBUTYL PHOSPHATE EXTRACTION PROCESS

    DOEpatents

    Wilson, A.S.

    1961-05-01

    A process is given for separating uranyl values from ruthenium values contained in an aqueous 3 to 4 M nitric acid solution. After the addition of hydrogen peroxide to obtain a concentration of 0.3 M, the uranium is selectively extracted with kerosene-diluted tributyl phosphate.

  18. Probing the structural evolution of ruthenium doped germanium clusters: Photoelectron spectroscopy and density functional theory calculations

    PubMed Central

    Jin, Yuanyuan; Lu, Shengjie; Hermann, Andreas; Kuang, Xiaoyu; Zhang, Chuanzhao; Lu, Cheng; Xu, Hongguang; Zheng, Weijun

    2016-01-01

    We present a combined experimental and theoretical study of ruthenium doped germanium clusters, RuGen− (n = 3–12), and their corresponding neutral species. Photoelectron spectra of RuGen− clusters are measured at 266 nm. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) are obtained. Unbiased CALYPSO structure searches confirm the low-lying structures of anionic and neutral ruthenium doped germanium clusters in the size range of 3 ≤ n ≤ 12. Subsequent geometry optimizations using density functional theory (DFT) at PW91/LANL2DZ level are carried out to determine the relative stability and electronic properties of ruthenium doped germanium clusters. It is found that most of the anionic and neutral clusters have very similar global features. Although the global minimum structures of the anionic and neutral clusters are different, their respective geometries are observed as the low-lying isomers in either case. In addition, for n > 8, the Ru atom in RuGen−/0 clusters is absorbed endohedrally in the Ge cage. The theoretically predicted vertical and adiabatic detachment energies are in good agreement with the experimental measurements. The excellent agreement between DFT calculations and experiment enables a comprehensive evaluation of the geometrical and electronic structures of ruthenium doped germanium clusters. PMID:27439955

  19. Synthesis and anticancer activity of carbosilane metallodendrimers based on arene ruthenium(ii) complexes.

    PubMed

    Maroto-Díaz, Marta; Elie, Benelita T; Gómez-Sal, Pilar; Pérez-Serrano, Jorge; Gómez, Rafael; Contel, María; Javier de la Mata, F

    2016-04-28

    A series of new organometallic carbosilane dendrimers (first and second generation) and the corresponding non-dendritic mononuclear based on ruthenium arene fragments are described. The metallodendrimers were prepared by reactions of the precursor [Ru(η(6)-p-cymene)Cl2]2 with carbosilane dendrimers functionalized with N-donor monodentate ligands such as NH2- and pyridine, or with N,O-, N,N-chelating imine ligands. While the dendrimer precursors are insoluble in DMSO or water, novel metallodendrimers are soluble in DMSO and some of them are even highly soluble in water. The molecular structure of the "Ru-NH2" mononuclear compound (zero generation) was determined by single-crystal X-ray crystallography. The cytotoxicity activity of these dendritic structures was evaluated in several human cancer cell lines and compared with that of the corresponding mononuclear ruthenium complexes. Most compounds display significant cytotoxic activities in the low micromolar range with the first generation ruthenium dendrimers being the most active compounds. The cell death type for selected compounds has been studied as well as their reactivity towards relevant biomolecules such as DNA, Human Serum Albumin (HSA) and Cathepsin-B. All the data point to a mode of action different from that of cisplatin for most complexes. First generation ruthenium dendrimers inhibit Cathepsin-B, which may suggest potential antimetastatic properties of these compounds.

  20. Differential Reactivities of Enyne Substrates in Ruthenium- and Palladium-Catalyzed Cycloisomerizations

    PubMed Central

    Trost, Barry M.; Gutierrez, Alicia C.; Ferreira, Eric M.

    2010-01-01

    Complementary methods for the transition metal-catalyzed enyne cycloisomerizations of cyclic olefins have been developed. By using distinct ruthenium and palladium catalysts, decalins and 7,6-bicycles can be obtained with dichotomous stereochemical outcomes. The change in mechanism that accompanies the change in metal affords trans-fused 1,4-dienes with ruthenium and their cis-fused diastereomers under palladium catalysis. In the reactions under ruthenium catalysis, a coordinating group is required, and acts to direct the metal to the same side of the carbocycle, resulting in the observed trans diastereoselectivity. Subtle changes in the carbocyclic substrate led to the discovery of a heretofore-unobserved mechanistic pathway, providing bicyclic cycloisomerization products under palladium catalysis and tricyclic products under ruthenium catalysis in DMA. The differential effect of DMA supports a mechanism in which the coordination requirements of the two paths differ, allowing for the reaction to be shuttled through the metallacycle pathway (generating tricyclic products) when DMA is used as a solvent. PMID:20545356

  1. Investigation of ruthenium dioxide formation mechanisms in containment glass synthesized by liquid feed

    SciTech Connect

    Sawada, K.; Shimada, T.; Sako, N.; Enokida, Y.; Schuller, S.; Angeli, F.; Charpentier, T.

    2013-07-01

    The presenting paper focuses on the structural configuration of ruthenium in vitreous matrices with the objective of obtaining more insight into ruthenium incorporation and solubilization mechanisms in borosilicate glasses. To determine the structural effect of an increasing RuO{sub 2} in a borosilicate glass, a series of glass samples were selected from a benchmark composition. {sup 11}B NMR shows that the borate network is influenced by the presence of RuO{sub 2} in the glass: the addition of 2% RuO{sub 2} in a borosilicate glass led to a significant rise of BO{sub 4}. RuO{sub 2} precipitated in the glass does not seem to be the cause of this modification because when RuO{sub 2} increase there is no further change of BO{sub 4} fraction. This effect can be therefore attributed to RuO{sub 2} dissolved in the glass. RuO{sub 2} is known to have a very low solubility in borosilicate glasses (50 to 2000 ppm depending on the temperature, sodium concentration and conditions of synthesis). The link between the ruthenium and the borated network is not yet clearly identified, however, assumptions can be made such as the formation of Ru-O-B when a sufficient quantity of Ru is add (> 400 ppm). Ruthenium could play the role of silicon in increasing the possibility of bridging bond formation with boron coordination number IV.

  2. Selective nuclei accumulation of ruthenium(II) complex enantiomers that target G-quadruplex DNA.

    PubMed

    Sun, Dongdong; Liu, Yanan; Yu, Qianqian; Liu, Du; Zhou, Yanhui; Liu, Jie

    2015-09-01

    Different enantiomers exhibit large differences in their biological activity and/or toxicity, but they rarely involve the relationship of the agents for molecular and cellular imaging with the chiral structure of ruthenium complexes. Here, we report that an enantiomer of a polypyridyl ruthenium complex can selectively accumulate in the nucleus of HepG2 cells. Confocal laser scanning microscopy studies show that this phenomenon occurs via a non-endocytotic, but temperature-dependent, mechanism of cellular uptake in HepG2 cells. DNA oligonucleotides with repetitive tracts of guanine bases that can form G-quadruplex structures have aroused interest as therapeutic agents and as targets for anticancer drug design. Various biophysical techniques show that the Λ-enantiomer of ruthenium complexes can selectively stabilize human telomeric G-quadruplex DNA and has a strong preference for G-quadruplex over duplex DNA. Judged from the NMR results, we speculate that at higher 4:1 ligand/G-quadruplex stoichiometry, complex Λ-Ru is likely to bind with each groove of the tetraplex in a dimeric form or intercalate with the G-tetrad in the 3' terminal face and coexist with other modes. The molecular modeling analysis is in agreement with the NMR titrations performed in this investigation indicating that ruthenium complexes are actually characterized by a mixed binding mode. The results provide many opportunities for the development of novel agents for living cell-related studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Design of Photoactive Ruthenium Complexes to Study Electron Transfer and Proton Pumping in Cytochrome Oxidase

    PubMed Central

    Durham, Bill; Millett, Francis

    2011-01-01

    This review describes the development and application of photoactive ruthenium complexes to study electron transfer and proton pumping reactions in cytochrome c oxidase (CcO). CcO uses four electrons from Cc to reduce O2 to two waters, and pumps four protons across the membrane. The electron transfer reactions in cytochrome oxidase are very rapid, and cannot be resolved by stopped-flow mixing techniques. Methods have been developed to covalently attach a photoactive tris(bipyridine)ruthenium group [Ru(II)] to Cc to form Ru-39-Cc. Photoexcitation of Ru(II) to the excited state Ru(II*), a strong reductant, leads to rapid electron transfer to the ferric heme group in Cc, followed by electron transfer to CuA in CcO with a rate constant of 60,000 s−1. Ruthenium kinetics and mutagenesis studies have been used to define the domain for the interaction between Cc and CcO. New ruthenium dimers have also been developed to rapidly inject electrons into CuA of CcO with yields as high as 60%, allowing measurement of the kinetics of electron transfer and proton release at each step in the oxygen reduction mechanism. PMID:21939635

  4. Biological properties of novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles.

    PubMed

    Novak, Maria S; Büchel, Gabriel E; Keppler, Bernhard K; Jakupec, Michael A

    2016-06-01

    Since the discovery that nitric oxide (NO) is a physiologically relevant molecule, there has been great interest in the use of metal nitrosyl compounds as antitumor pharmaceuticals. Particularly interesting are those complexes which can deliver NO to biological targets. Ruthenium- and osmium-based compounds offer lower toxicity compared to other metals and show different mechanisms of action as well as different spectra of activity compared to platinum-based drugs. Novel ruthenium- and osmium-nitrosyl complexes with azole heterocycles were studied to elucidate their cytotoxicity and possible interactions with DNA. Apoptosis induction, changes of mitochondrial transmembrane potential and possible formation of reactive oxygen species were investigated as indicators of NO-mediated damage by flow cytometry. Results suggest that ruthenium- and osmium-nitrosyl complexes with the general formula (indazolium)[cis/trans-MCl4(NO)(1H-indazole)] have pronounced cytotoxic potency in cancer cell lines. Especially the more potent ruthenium complexes strongly induce apoptosis associated with depolarization of mitochondrial membranes, and elevated reactive oxygen species levels. Furthermore, a slight yet not unequivocal trend to accumulation of intracellular cyclic guanosine monophosphate attributable to NO-mediated effects was observed.

  5. Inhibitory effects of NAMI-A-like ruthenium complexes on prion neuropeptide fibril formation.

    PubMed

    Wang, Xuesong; Zhu, Dengsen; Zhao, Cong; He, Lei; Du, Weihong

    2015-05-01

    Prion diseases are a group of infectious and fatal neurodegenerative disorders caused by the conformational conversion of a cellular prion protein (PrP) into its abnormal isoform PrP(Sc). PrP106-126 resembles PrP(Sc) in terms of physicochemical and biological characteristics and is used as a common model for the treatment of prion diseases. Inhibitory effects on fibril formation and neurotoxicity of the prion neuropeptide PrP106-126 have been investigated using metal complexes as potential inhibitors. Nevertheless, the binding mechanism between metal complexes and the peptide remains unclear. The present study is focused on the interaction of PrP106-126 with NAMI-A and NAMI-A-like ruthenium complexes, including KP418, KP1019, and KP1019-2. Results demonstrated that these ruthenium complexes could bind to PrP106-126 in a distinctive binding mode through electrostatic and hydrophobic interactions. NAMI-A-like ruthenium complexes can also effectively inhibit the aggregation and fibril formation of PrP106-126. The complex KP1019 demonstrated the optimal inhibitory ability upon peptide aggregation, and cytotoxicity because of its large aromatic ligand contribution. The studied complexes could also regulate the copper redox chemistry of PrP106-126 and effectually inhibit the formation of reactive oxygen species. Given these findings, ruthenium complexes with relatively low cellular toxicity may be used to develop potential pharmaceutical products against prion diseases.

  6. SORPTION OF ARSENATE AND ARSENITE ON A RUTHENIUM COMPOUND: A MACROSCOPIC AND MICROSCOPIC STUDY

    EPA Science Inventory

    Sorption of arsenate and arsenite was examined on a ruthenium compound using macroscopic and microscopic techniques. Batch sorption experiments at pH 4,5,6, 7 and 8 were employed to construct constant solid solution ratio isotherms (CSI). After equilibration at the appropriate pH...

  7. Cytoxicity and Apoptotic Mechanism of Ruthenium(II) Amino Acid Complexes in Sarcoma-180 Tumor Cells

    PubMed Central

    Lima, Aliny Pereira; Pereira, Flávia Castro; Almeida, Marcio Aurelio Pinheiro; Mello, Francyelli Mariana Santos; Pires, Wanessa Carvalho; Pinto, Thallita Monteiro; Delella, Flávia Karina; Felisbino, Sérgio Luis; Moreno, Virtudes; Batista, Alzir Azevedo; de Paula Silveira-Lacerda, Elisângela

    2014-01-01

    Over the past several decades, much attention has been focused on ruthenium complexes in antitumor therapy. Ruthenium is a transition metal that possesses several advantages for rational antitumor drug design and biological applications. In the present study, five ruthenium complexes containing amino acids were studied in vitro to determine their biological activity against sarcoma-180 tumor cells. The cytotoxicity of the complexes was evaluated by an MTT assay, and their mechanism of action was investigated. The results demonstrated that the five complexes inhibited the growth of the S180 tumor cell line, with IC50 values ranging from 22.53 µM to 50.18 µM, and showed low cytotoxicity against normal L929 fibroblast cells. Flow cytometric analysis revealed that the [Ru(gly)(bipy)(dppb)]PF6 complex (2) inhibited the growth of the tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and G0/G1 phase cell cycle arrest. Further investigation showed that complex 2 caused a loss of mitochondrial membrane potential; activated caspases 3, caspase-8, and caspase-9 and caused a change in the mRNA expression levels of caspase 3, caspase-9 as well as the bax genes. The levels of the pro-apoptotic Bcl-2 family protein Bak were increased. Thus, we demonstrated that ruthenium amino acid complexes are promising drugs against S180 tumor cells, and we recommend further investigations of their role as chemotherapeutic agents for sarcomas. PMID:25329644

  8. SORPTION OF LEAD ON A RUTHENIUM COMPOUND: A MACROSCOPIC AND MICROSCOPIC STUDY

    EPA Science Inventory

    The objective of this study was to elucidate the sorption mechanism of Pb on the high-affinity ruthenium compound with time at pH 6 employing batch methods and X-ray absorption fine structure (XAFS) and X-ray diffraction (XRD) spectroscopies. For the spectroscopic studies, Pb so...

  9. Olefin Ring Closing Metathesis and Hydrosilylation Reaction in Aqueous Medium by Grubbs Second Generation Ruthenium Catalyst

    EPA Science Inventory

    The Grubbs second generation ruthenium catalyst was shown to catalyze various olefin ring closing metathesis and hydrosilylation reactions in aqueous medium. Reactions proceeded in pure water without any additives or co-solvents, in a short period of time. We found that inhomogen...

  10. Effects of ruthenium seed layer on the microstructure and spin dynamics of thin permalloy films

    SciTech Connect

    Jin Lichuan; Zhang Huaiwu; Tang Xiaoli; Bai Feiming; Zhong Zhiyong

    2013-02-07

    The spin dynamics and microstructure properties of a sputtered 12 nm Ni{sub 81}Fe{sub 19} thin film have been enhanced by the use of a ruthenium seed layer. Both the ferromagnetic resonance field and linewidth are enhanced dramatically as the thickness of ruthenium seed layer is increased. The surface anisotropy energy constant can also be largely tailored from 0.06 to 0.96 erg/cm{sup -2} by changing the seed layer thickness. The changes to the dynamics magnetization properties are caused by both ruthenium seed layer induced changes in the Ni{sub 81}Fe{sub 19} structure properties and surface topography properties. Roughness induced inhomogeneous linewidth broadening is also seen. The damping constant is highly tunable via the ruthenium thickness. This approach can be used to tailor both the structure and spin dynamic properties of thin Ni{sub 81}Fe{sub 19} films over a wide range. And it may benefit the applications of spin dynamics and spin current based devices.

  11. Recent Advances on Dark and Light-Activated Cytotoxity of Imidazole-Containing Ruthenium Complexes.

    PubMed

    Liu, Ping; Jia, Jia; Zhao, Yue; Wang, Ke-Zhi

    2016-01-01

    Imidazole derivatives have known to possess a diverse range of pharmacological activity. In particular, one of ruthenium-based derivatives, imidazolium [trans-RuCl4(1H-imidazole)(DMSOS)] (NAMI-A) which is now in clinical trials, opens a new avenue for developing promising ruthenium-based anticancer drugs alternative to Cisplatin. This mini-review overviews some representative examples of imidazole-containing ruthenium complexes (ICRCs) with in vitro anticancer activities. Special attention is paid on ICRCs with the activities more potent than Cisplatin, and their correlation with their DNA binding properties in the context of possible cancer chemotherapeutic applications. The ICRCs are divided into two main categories according to their dark and light activated cytotoxicity; the former case is further clarified into mononuclear complexes including tris(bidentate polypyridyl) ruthenium complexes and those containing monodentatively coordinative imidazole ligands as well as polynuclear complexes. The perspective, challenges and future efforts for investigations into ICRCs are pointed out or suggested.

  12. Synthesis, Anticancer Activity, and Genome Profiling of Thiazolo Arene Ruthenium Complexes.

    PubMed

    Grozav, Adriana; Balacescu, Ovidiu; Balacescu, Loredana; Cheminel, Thomas; Berindan-Neagoe, Ioana; Therrien, Bruno

    2015-11-12

    Sixteen hydrazinyl-thiazolo arene ruthenium complexes of the general formula [(η(6)-p-cymene)Ru(N,N'-hydrazinyl-thiazolo)Cl]Cl were synthesized. All complexes were tested in vitro for their antiproliferative activity on three tumor cell lines (HeLa, A2780, and A2780cisR) and on a noncancerous cell line (HFL-1). A superior cytotoxic activity of the ruthenium complexes as compared to cisplatin and oxaliplatin, on both cisplatin-sensitive and cisplatin resistant ovarian cancer cells, was observed. In addition, the biological activity of two selected derivatives was evaluated using microarray gene expression assay and ingenuity pathway analysis. p53 signaling was identified as an important pathway modulated by both arene ruthenium compounds. New activated molecules such as FAS, ZMAT3, PRMT2, BBC3/PUMA, and PDCD4, whose overexpressions are correlated with overcoming resistance to cisplatin therapy, were also identified as potential targets. Moreover, the arene ruthenium complexes can be used in association with cisplatin to prevent cisplatin resistance development and synergistically to induce cell death in ovarian cancer cells.

  13. Magnetically Recoverable Supported Ruthenium Catalyst for Hydrogenation of Alkynes and Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    A ruthenium (Ru) catalyst supported on magnetic nanoparticles (NiFe2O4) has been successfully synthesized and used for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The cata...

  14. Cis-Selective Ring-Opening Metathesis Polymerization with Ruthenium Catalysts

    PubMed Central

    Keitz, Benjamin K.; Fedorov, Alexey; Grubbs, Robert H.

    2012-01-01

    Using a C-H activated, ruthenium-based metathesis catalyst, the cis selective ROMP of several monocyclic alkenes, as well as norbornene and oxanorbornene-type monomers is reported. The cis content of the isolated polymers depended heavily on monomer structure and temperature. By lowering the temperature, cis content as high as 96% could be obtained. PMID:22239675

  15. Strategy to tether organometallic ruthenium-arene anticancer compounds to recombinant human serum albumin.

    PubMed

    Ang, Wee Han; Daldini, Elisa; Juillerat-Jeanneret, Lucienne; Dyson, Paul J

    2007-10-29

    In order to utilize macromolecules for drug targeting and delivery, a strategy to tether organometallic ruthenium-arene drugs to carrier protein molecules was developed. The approach involves the design of a drug fragment capable of conjugating to linker molecules on a modified carrier protein via hydrazone bond formation. The proof-of-concept using recombinant human serum albumin is described.

  16. Ruthenium bipyridyl tethered porous organosilica: a versatile, durable and reusable heterogeneous photocatalyst.

    PubMed

    Jana, Avijit; Mondal, John; Borah, Parijat; Mondal, Sujan; Bhaumik, Asim; Zhao, Yanli

    2015-07-07

    A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides.

  17. Probing the structural evolution of ruthenium doped germanium clusters: Photoelectron spectroscopy and density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Jin, Yuanyuan; Lu, Shengjie; Hermann, Andreas; Kuang, Xiaoyu; Zhang, Chuanzhao; Lu, Cheng; Xu, Hongguang; Zheng, Weijun

    2016-07-01

    We present a combined experimental and theoretical study of ruthenium doped germanium clusters, RuGen- (n = 3-12), and their corresponding neutral species. Photoelectron spectra of RuGen- clusters are measured at 266 nm. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) are obtained. Unbiased CALYPSO structure searches confirm the low-lying structures of anionic and neutral ruthenium doped germanium clusters in the size range of 3 ≤ n ≤ 12. Subsequent geometry optimizations using density functional theory (DFT) at PW91/LANL2DZ level are carried out to determine the relative stability and electronic properties of ruthenium doped germanium clusters. It is found that most of the anionic and neutral clusters have very similar global features. Although the global minimum structures of the anionic and neutral clusters are different, their respective geometries are observed as the low-lying isomers in either case. In addition, for n > 8, the Ru atom in RuGen-/0 clusters is absorbed endohedrally in the Ge cage. The theoretically predicted vertical and adiabatic detachment energies are in good agreement with the experimental measurements. The excellent agreement between DFT calculations and experiment enables a comprehensive evaluation of the geometrical and electronic structures of ruthenium doped germanium clusters.

  18. Probing the structural evolution of ruthenium doped germanium clusters: Photoelectron spectroscopy and density functional theory calculations.

    PubMed

    Jin, Yuanyuan; Lu, Shengjie; Hermann, Andreas; Kuang, Xiaoyu; Zhang, Chuanzhao; Lu, Cheng; Xu, Hongguang; Zheng, Weijun

    2016-07-21

    We present a combined experimental and theoretical study of ruthenium doped germanium clusters, RuGen(-) (n = 3-12), and their corresponding neutral species. Photoelectron spectra of RuGen(-) clusters are measured at 266 nm. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) are obtained. Unbiased CALYPSO structure searches confirm the low-lying structures of anionic and neutral ruthenium doped germanium clusters in the size range of 3 ≤ n ≤ 12. Subsequent geometry optimizations using density functional theory (DFT) at PW91/LANL2DZ level are carried out to determine the relative stability and electronic properties of ruthenium doped germanium clusters. It is found that most of the anionic and neutral clusters have very similar global features. Although the global minimum structures of the anionic and neutral clusters are different, their respective geometries are observed as the low-lying isomers in either case. In addition, for n > 8, the Ru atom in RuGen(-/0) clusters is absorbed endohedrally in the Ge cage. The theoretically predicted vertical and adiabatic detachment energies are in good agreement with the experimental measurements. The excellent agreement between DFT calculations and experiment enables a comprehensive evaluation of the geometrical and electronic structures of ruthenium doped germanium clusters.

  19. Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise.

    PubMed

    Rapp, Teresa L; Phillips, Susan R; Dmochowski, Ivan J

    2016-12-13

    The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently "caging" biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model "caged" acetonitrile complex, Ru(2,2'-bipyridine)2(acetonitrile)2, or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV-vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course.

  20. Design of photoactive ruthenium complexes to study electron transfer and proton pumping in cytochrome oxidase.

    PubMed

    Durham, Bill; Millett, Francis

    2012-04-01

    This review describes the development and application of photoactive ruthenium complexes to study electron transfer and proton pumping reactions in cytochrome c oxidase (CcO). CcO uses four electrons from Cc to reduce O(2) to two waters, and pumps four protons across the membrane. The electron transfer reactions in cytochrome oxidase are very rapid, and cannot be resolved by stopped-flow mixing techniques. Methods have been developed to covalently attach a photoactive tris(bipyridine)ruthenium group [Ru(II)] to Cc to form Ru-39-Cc. Photoexcitation of Ru(II) to the excited state Ru(II*), a strong reductant, leads to rapid electron transfer to the ferric heme group in Cc, followed by electron transfer to Cu(A) in CcO with a rate constant of 60,000s(-1). Ruthenium kinetics and mutagenesis studies have been used to define the domain for the interaction between Cc and CcO. New ruthenium dimers have also been developed to rapidly inject electrons into Cu(A) of CcO with yields as high as 60%, allowing measurement of the kinetics of electron transfer and proton release at each step in the oxygen reduction mechanism.

  1. Olefin Ring Closing Metathesis and Hydrosilylation Reaction in Aqueous Medium by Grubbs Second Generation Ruthenium Catalyst

    EPA Science Inventory

    The Grubbs second generation ruthenium catalyst was shown to catalyze various olefin ring closing metathesis and hydrosilylation reactions in aqueous medium. Reactions proceeded in pure water without any additives or co-solvents, in a short period of time. We found that inhomogen...

  2. SORPTION OF ARSENATE AND ARSENITE ON A RUTHENIUM COMPOUND: A MACROSCOPIC AND MICROSCOPIC STUDY

    EPA Science Inventory

    Sorption of arsenate and arsenite was examined on a ruthenium compound using macroscopic and microscopic techniques. Batch sorption experiments at pH 4,5,6, 7 and 8 were employed to construct constant solid solution ratio isotherms (CSI). After equilibration at the appropriate pH...

  3. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cell Stacks

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    Dissolution of ruthenium was observed in the 80-cell stack. Duration testing was performed in single cell MEAs to determine the pathway of cell degradation. EDAX analysis on each of the single cell MEAs has shown that the Johnson Matthey commercial catalyst is stable in DMFC operation for 250 hours, no ruthenium dissolution was observed. Changes in the hydrophobicity of the cathode backing papers was minimum. Electrode polarization analysis revealed that the MEA performance loss is attributed to changes in the cathode catalyst layer. Ruthenium migration does not seem to occur during cell operation but can occur when methanol is absent from the anode compartment, the cathode compartment has access to air, and the cells in the stack are electrically connected to a load (Shunt Currents). The open-to-air cathode stack design allowed for: a) The MEAs to have continual access to oxygen; and b) The stack to sustain shunt currents. Ruthenium dissolution in a DMFC stack can be prevented by: a) Developing an internally manifolded stacks that seal reactant compartments when not in operation; b) Bringing the cell voltages to zero quickly when not in operation; and c) Limiting the total number of cells to 25 in an effort to limit shunt currents.

  4. Magnetically Recoverable Supported Ruthenium Catalyst for Hydrogenation of Alkynes and Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    A ruthenium (Ru) catalyst supported on magnetic nanoparticles (NiFe2O4) has been successfully synthesized and used for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The cata...

  5. SORPTION OF LEAD ON A RUTHENIUM COMPOUND: A MACROSCOPIC AND MICROSCOPIC STUDY

    EPA Science Inventory

    The objective of this study was to elucidate the sorption mechanism of Pb on the high-affinity ruthenium compound with time at pH 6 employing batch methods and X-ray absorption fine structure (XAFS) and X-ray diffraction (XRD) spectroscopies. For the spectroscopic studies, Pb so...

  6. Method for producing electricity using a platinum-ruthenium-palladium catalyst in a fuel cell

    DOEpatents

    Gorer, Alexander

    2004-01-27

    A method for producing electricity using a fuel cell that utilizes a ternary alloy composition as a fuel cell catalyst, the ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

  7. Cytoxicity and apoptotic mechanism of ruthenium(II) amino acid complexes in sarcoma-180 tumor cells.

    PubMed

    Lima, Aliny Pereira; Pereira, Flávia Castro; Almeida, Marcio Aurelio Pinheiro; Mello, Francyelli Mariana Santos; Pires, Wanessa Carvalho; Pinto, Thallita Monteiro; Delella, Flávia Karina; Felisbino, Sérgio Luis; Moreno, Virtudes; Batista, Alzir Azevedo; de Paula Silveira-Lacerda, Elisângela

    2014-01-01

    Over the past several decades, much attention has been focused on ruthenium complexes in antitumor therapy. Ruthenium is a transition metal that possesses several advantages for rational antitumor drug design and biological applications. In the present study, five ruthenium complexes containing amino acids were studied in vitro to determine their biological activity against sarcoma-180 tumor cells. The cytotoxicity of the complexes was evaluated by an MTT assay, and their mechanism of action was investigated. The results demonstrated that the five complexes inhibited the growth of the S180 tumor cell line, with IC50 values ranging from 22.53 µM to 50.18 µM, and showed low cytotoxicity against normal L929 fibroblast cells. Flow cytometric analysis revealed that the [Ru(gly)(bipy)(dppb)]PF6 complex (2) inhibited the growth of the tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and G0/G1 phase cell cycle arrest. Further investigation showed that complex 2 caused a loss of mitochondrial membrane potential; activated caspases 3, caspase-8, and caspase-9 and caused a change in the mRNA expression levels of caspase 3, caspase-9 as well as the bax genes. The levels of the pro-apoptotic Bcl-2 family protein Bak were increased. Thus, we demonstrated that ruthenium amino acid complexes are promising drugs against S180 tumor cells, and we recommend further investigations of their role as chemotherapeutic agents for sarcomas.

  8. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cells Stacks

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    This viewgraph presentation gives a detailed review of the Direct Methanol Based Fuel Cell (DMFC) stack and investigates the Ruthenium that was found at the exit of the stack. The topics include: 1) Motivation; 2) Pathways for Cell Degradation; 3) Cell Duration Testing; 4) Duration Testing, MEA Analysis; and 5) Stack Degradation Analysis.

  9. Advances in Photocatalysis: A Microreview of Visible Light Mediated Ruthenium and Iridium Catalyzed Organic Transformations.

    PubMed

    Day, Jon I; Teegardin, Kip; Weaver, Jimmie; Chan, John

    2016-07-15

    Photocatalytic organic transformations utilizing ruthenium and iridium complexes have garnered significant attention due to the access they provide to new synthetic spaces through new reaction mechanisms. A survey of the photophysical data and the diversity of transformations that may be accomplished utilizing commercially available photocatalysts is contained herein.

  10. Ruthenium-catalyzed direct C-H amidation of arenes including weakly coordinating aromatic ketones.

    PubMed

    Kim, Jiyu; Kim, Jinwoo; Chang, Sukbok

    2013-06-03

    C-H activation: The ruthenium-catalyzed direct sp(2) C-H amidation of arenes by using sulfonyl azides as the amino source is presented (see scheme). A wide range of substrates were readily amidated including arenes bearing weakly coordinating groups. Synthetic utility of the thus obtained products was demonstrated in the preparation of biologically active heterocycles.

  11. Metalation dictates remote regioselectivity: ruthenium-catalyzed functionalization of meta C(Ar)-H Bonds.

    PubMed

    Juliá-Hernández, Francisco; Simonetti, Marco; Larrosa, Igor

    2013-10-25

    Remote control: The title reaction is effective for the sulfonation and alkylation of arenes bearing directing groups. Initial ortho metalation of the substrate forms an intermediate which does not evolve towards functionalization at the CM bond. Instead, the ruthenium catalyst acts as a strong electron-donating group, thus directing a remote electrophilic attack.

  12. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cell Stacks

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    Dissolution of ruthenium was observed in the 80-cell stack. Duration testing was performed in single cell MEAs to determine the pathway of cell degradation. EDAX analysis on each of the single cell MEAs has shown that the Johnson Matthey commercial catalyst is stable in DMFC operation for 250 hours, no ruthenium dissolution was observed. Changes in the hydrophobicity of the cathode backing papers was minimum. Electrode polarization analysis revealed that the MEA performance loss is attributed to changes in the cathode catalyst layer. Ruthenium migration does not seem to occur during cell operation but can occur when methanol is absent from the anode compartment, the cathode compartment has access to air, and the cells in the stack are electrically connected to a load (Shunt Currents). The open-to-air cathode stack design allowed for: a) The MEAs to have continual access to oxygen; and b) The stack to sustain shunt currents. Ruthenium dissolution in a DMFC stack can be prevented by: a) Developing an internally manifolded stacks that seal reactant compartments when not in operation; b) Bringing the cell voltages to zero quickly when not in operation; and c) Limiting the total number of cells to 25 in an effort to limit shunt currents.

  13. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cells Stacks

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

    2005-01-01

    This viewgraph presentation gives a detailed review of the Direct Methanol Based Fuel Cell (DMFC) stack and investigates the Ruthenium that was found at the exit of the stack. The topics include: 1) Motivation; 2) Pathways for Cell Degradation; 3) Cell Duration Testing; 4) Duration Testing, MEA Analysis; and 5) Stack Degradation Analysis.

  14. Diphosphite ligands derived from carbohydrates as stabilizers for ruthenium nanoparticles: promising catalytic systems in arene hydrogenation.

    PubMed

    Gual, Aitor; Axet, M Rosa; Philippot, Karine; Chaudret, Bruno; Denicourt-Nowicki, Audrey; Roucoux, Alain; Castillon, Sergio; Claver, Carmen

    2008-06-28

    Ruthenium nanoparticles (RuNPs) were prepared through the hydrogenation of [Ru(COD)(COT)] (COD = 1,5-cyclooctadiene, COT = 1,3,5-cyclooctatriene) in the presence of diphosphites derived from carbohydrates as stabilizing agents, and interestingly, structural modifications of the diphosphite backbone were found to influence nanoparticle size and dispersity, as well as their catalytic activity in arene hydrogenation.

  15. Ruthenium-Catalyzed Synthesis of β-Hydroxyamides from β-Ketonitriles in Water.

    PubMed

    González-Fernández, Rebeca; Crochet, Pascale; Cadierno, Victorio

    2016-12-02

    An unprecedented hydration/transfer hydrogenation tandem process for the catalytic conversion of β-ketonitriles into synthetically useful β-hydroxyamides in water has been developed, making use of the ruthenium(II) complex [RuCl2(η(6)-p-cymene){P(4-C6H4F)2Cl}] in combination with sodium formate.

  16. A GSH-activatable ruthenium(ii)-azo photosensitizer for two-photon photodynamic therapy.

    PubMed

    Zeng, Leli; Kuang, Shi; Li, Guanying; Jin, Chengzhi; Ji, Liangnian; Chao, Hui

    2017-02-07

    A glutathione (GSH)-activatable ruthenium(ii)-azo photosensitizer was prepared. The complex had low toxicity towards cells under dark conditions. It exhibited excellent phototoxicity under two-photon excitation (810 nm) and thus was developed as a two-photon photodynamic anticancer agent for cancer therapy.

  17. Simultaneous determination of iron and ruthenium as ternary complexes by extractive second derivative spectrophotometry.

    PubMed

    Toral, M I; Richter, P; Tapia, A E; Hernández, J

    1999-08-23

    A highly sensitive and selective second derivative spectrophotometric method has been developed for the determination of ruthenium and iron in mixtures. The method is based on the formation of the binary complexes of iron and ruthenium with 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline) in the presence of ethyleneglycol. These complexes are formed at pH 4.0-6.0 upon heating at 90 degrees C for 60 min. The ternary perchlorate complexes are then separated by liquid-liquid extraction. The extracts were evaluated directly by derivative spectrophotometric measurement, using the zero-crossing approach for determination of both analytes. Ruthenium and iron were thus determined in the ranges 9.6-450 and 16.3-280 ng/ml, respectively, in the presence of one another. The detection limits achieved (3sigma) were found to be 2.9 ng/ml of ruthenium and 4.9 ng/ml of iron. The relative standard deviations were in all instances less than 1.5%. The proposed method was applied to the determination of both analytes in synthetic mixtures.

  18. An improved ruthenium catalyst for the environmentally benign amination of primary and secondary alcohols.

    PubMed

    Hollmann, Dirk; Tillack, Annegret; Michalik, Dirk; Jackstell, Ralf; Beller, Matthias

    2007-03-05

    The N-alkylation of amines in the presence of different ruthenium catalysts generated in situ was investigated. Among the various catalysts tested, the combination of [Ru3(CO)12] and N-phenyl-2-(dicyclohexylphosphanyl)pyrrole showed the best performance. By applying this novel catalyst, a variety of functionalized alcohols and amines were converted into the corresponding secondary amines in high yield.

  19. A new designed hydrazine group-containing ruthenium complex used for catalytic hydrogenation of esters.

    PubMed

    Tan, Xuefeng; Wang, Qingli; Liu, Yuanhua; Wang, Fangyuan; Lv, Hui; Zhang, Xumu

    2015-08-07

    A hydrazine group-containing nitrogen-phosphine ligand and corresponding ruthenium complexes were synthesized. When these complexes were used for hydrogenation of esters, excellent performance was observed (TON up to 17, 200). A wide substrate scope was suitable for this catalytic system.

  20. Dithia[3.3]paracyclophane-based monometal ruthenium acetylide complexes: synthesis, characterization and substituent effects.

    PubMed

    Zhu, Xingxun; Ou, Yaping; Zhang, Jing; Xia, Jian-Long; Yin, Jun; Yu, Guang-Ao; Liu, Sheng Hua

    2013-05-21

    A series of dithia[3.3]metaparacyclophane-based monometal ruthenium acetylide complexes have been synthesized. All of the complexes have been fully characterised by NMR spectrometry, X-ray crystallography and elemental analyses. At the same time, their basic optical properties, such as UV/Vis absorption spectra, and electrochemical properties have been determined. (1)H NMR and X-ray crystal structure studies reveal that there are intramolecular C-H···π interactions in these ruthenium complexes, in both solution and solid states. Electrochemical studies reveal that the substituted groups on the dithia[3.3]paracyclophane ring can clearly affect the oxidation activities of the ruthenium center by way of the intramolecular C-H···π interaction. In addition, electron-donating groups facilitate the oxidation of the ruthenium center compared with electron-deficient groups. UV/Vis absorption and IR spectra of some complexes in neutral and oxidized states also have been studied. IR spectra studies indicated that the substituents in the cyclophane have some effects on the ν(C≡C) bands of these complexes in the neutral state and little effect on ν(C≡C) of these complexes in the oxidized state.

  1. Mechanistic study of hydrogen transfer to imines from a hydroxycyclopentadienyl ruthenium hydride. Experimental support for a mechanism involving coordination of imine to ruthenium prior to hydrogen transfer.

    PubMed

    Samec, Joseph S M; Ell, Alida H; Aberg, Jenny B; Privalov, Timofei; Eriksson, Lars; Bäckvall, Jan-E

    2006-11-08

    Reaction of [2,3,4,5-Ph(4)(eta(5)-C(4)COH)Ru(CO)(2)H] (2) with different imines afforded ruthenium amine complexes at low temperatures. At higher temperatures in the presence of 2, the complexes decomposed to give [Ru(2)(CO)(4)(mu-H)(C(4)Ph(4)COHOCC(4)Ph(4))] (1) and free amine. Electron-rich imines gave ruthenium amine complexes with 2 at a lower temperature than did electron-deficient imines. The negligible deuterium isotope effect (k(RuHOH)/k(RuDOD) = 1.05) observed in the reaction of 2 with N-phenyl[1-(4-methoxyphenyl)ethylidene]amine (12) shows that neither hydride (RuH) nor proton (OH) is transferred to the imine in the rate-determining step. In the dehydrogenation of N-phenyl-1-phenylethylamine (4) to the corresponding imine 8 by [2,3,4,5-Ph(4)(eta(4)-C(4)CO)Ru(CO)(2)] (A), the kinetic isotope effects observed support a stepwise hydrogen transfer where the isotope effect for C-H cleavage (k(CHNH)/k(CDNH) = 3.24) is equal to the combined (C-H, N-H) isotope effect (k(CHNH)/k(CDND) = 3.26). Hydrogenation of N-methyl(1-phenylethylidene)amine (14) by 2 in the presence of the external amine trap N-methyl-1-(4-methoxyphenyl)ethylamine (16) afforded 90-100% of complex [2,3,4,5-Ph(4)(eta(4)-C(4)CO)]Ru(CO)(2)NH(CH(3))(CHPhCH(3)) (15), which is the complex between ruthenium and the amine newly generated from the imine. At -80 degrees C the reaction of hydride 2 with 4-BnNH-C(6)H(9)=NPh (18), with an internal amine trap, only afforded [2,3,4,5-Ph(4)(eta(4)-C(4)CO)](CO)(2)RuNH(Ph)(C(6)H(10)-4-NHBn) (19), where the ruthenium binds to the amine originating from the imine, showing that neither complex A nor the diamine is formed. Above -8 degrees C complex 19 rearranged to the thermodynamically more stable [Ph(4)(eta(4)-C(4)CO)](CO)(2)RuNH(Bn)(C(6)H(10)-4-NHPh) (20). These results are consistent with an inner sphere mechanism in which the substrate coordinates to ruthenium prior to hydrogen transfer and are difficult to explain with the outer sphere pathway previously

  2. 99Mo/(99m)Tc separation: an assessment of technology options.

    PubMed

    Dash, Ashutosh; Knapp, F F Russ; Pillai, M R A

    2013-02-01

    Several strategies for the effective separation of (99m)Tc from (99)Mo have been developed and validated. Due to the success of column chromatographic separation using acidic alumina coupled with high specific activity fission (99)Mo (F (99)Mo) for production of (99)Mo/(99m)Tc generators, however, most technologies until recently have generated little interest. The reduced availability of F (99)Mo and consequently the shortage of (99)Mo/(99m)Tc column generators in the recent past have resurrected interest in the production of (99)Mo as well as (99m)Tc by alternate routes. Most of these alternative production processes require separation techniques capable of providing clinical grade (99m)Tc from low specific activity (99)Mo or irradiated Mo targets. For this reason there has been renewed interest in alternate separation routes. This paper reviews the reported separation technologies which include column chromatography, solvent extraction, sublimation and gel systems that have been traditionally used for the fabrication of (99)Mo/(99m)Tc generator systems. The comparative advantage, disadvantage, and technical challenges toward adapting the emerging requirements are discussed. New developments such as solid-phase column extraction, electrochemical separation, extraction chromatography, supported liquid membrane (SLM) and thermochromatographic techniques are also being evaluated for their potential application in the changed scenario of providing (99m)Tc from alternate routes. Based on the analysis provided in this review, it appears that some proven separation technologies can be quickly resurrected for the separation of clinical grade (99m)Tc from macroscopic levels of reactor or cyclotron irradiated molybdenum targets. Furthermore, emerging technologies can be developed further to respond to the expected changing modes of (99m)Tc production.

  3. Mo-99/Tc-99m Separation: An Assessment of Technical Options

    SciTech Connect

    Dash, A; Pillai, M R A; Knapp Jr, Russ F

    2013-01-01

    Several strategies for the effective separation of 99mTc from 99Mo have been developed and validated. Due to the success of column chromatographic separation using acidic alumina coupled with high specific activity fission 99Mo (F 99Mo) for production of 99Mo/99mTc generators, however, most technologies until recently have generated little interest. The reduced availability of F 99Mo and consequently the shortage of 99Mo/99mTc column generators in the recent past have resurrected interest in the production of 99Mo as well as 99mTc by alternate routes. Most of these alternative production processes require separation techniques capable of providing clinical grade 99mTc from low specific activity 99Mo or irradiated Mo targets. For this reason there has been renewed interest in alternate separation routes. This paper reviews the reported separation technologies which include column chromatography, solvent extraction, sublimation and gel systems that have been traditionally used for the fabrication of 99Mo/99mTc generator systems. The comparative advantage, disadvantage, and technical challenges toward adapting the emerging requirements are discussed. New developments such as solid-phase column extraction, electrochemical separation, extraction chromatography, supported liquid membrane (SLM) and thermochromatographic techniques are also being evaluated for their potential application in the changed scenario of providing 99mTc from alternate routes. Based on the analysis provided in this review, it appears that some proven separation technologies can be quickly resurrected for the separation of clinical grade 99mTc from macroscopic levels of reactor or cyclotron irradiated molybdenum targets. Furthermore, emerging technologies can be developed further to respond to the expected changing modes of 99mTc production.

  4. Use of Ruthenium Photooxidation Techniques to Study Electron Transfer in the Cytochrome bc1 Complex

    PubMed Central

    Millett, Francis; Durham, Bill

    2009-01-01

    Ruthenium photooxidation methods are presented to study electron transfer between the cytochrome bc1 complex and cytochrome c, and within the cytochrome bc1 complex. Methods are described to prepare a ruthenium cytochrome c derivative, Ruz-39-Cc, by labeling the single sulfhydryl on yeast H39C;C102T iso-1-Cc with the reagent Ru(bpz)2(4-bromomethyl-4′-methylbipyridine). The ruthenium complex attached to Cys-39 on the opposite side of Cc from the heme crevice does not affect the interaction with cyt bc1. Laser excitation of reduced Ruz-39-Cc results in photooxidation of heme c within 1 μs with a yield of 20%. Flash photolysis of a 1:1 complex between reduced yeast cytochrome bc1 and Ruz-39-Cc leads to electron transfer from heme c1 to heme c with a rate constant of 1.4 × 104 s-1. Methods are described for the use of the ruthenium dimer, Ru2D, to photooxidize cyt c1 in the cytochrome bc1 complex within 1 μs with a yield of 20%. Electron transfer from the Rieske iron-sulfur center [2Fe2S] to cyt c1 was detected with a rate constant of 6 × 104 s-1 in R. sphaeroides cyt bc1 using this method. This electron transfer step is rate-limited by the rotation of the Rieske iron-sulfur protein in a conformational gating mechanism. This method provides critical information on the dynamics of rotation of the iron-sulfur protein (ISP) as it transfers electrons from QH2 in the Qo site to cyt c1 These ruthenium photooxidation methods can be used to measure many of the electron transfer reactions in cytochrome bc1 complexes from any source. PMID:19348884

  5. The nature of unsupported uranium-ruthenium bonds: a combined experimental and theoretical study.

    PubMed

    Gardner, Benedict M; Patel, Dipti; Cornish, Andrew D; McMaster, Jonathan; Lewis, William; Blake, Alexander J; Liddle, Stephen T

    2011-09-26

    Four new uranium-ruthenium complexes, [(Tren(TMS))URu(η(5)-C(5)H(5))(CO)(2)] (9), [(Tren(DMSB))URu(η(5)-C(5)H(5))(CO)(2)] (10), [(Ts(Tolyl))(THF)URu(η(5)-C(5)H(5))(CO)(2)] (11), and [(Ts(Xylyl))(THF)URu(η(5)-C(5)H(5))(CO)(2)] (12) [Tren(TMS)=N(CH(2)CH(2)NSiMe(3))(3); Tren(DMSB)=N(CH(2)CH(2)NSiMe(2)tBu)(3)]; Ts(Tolyl)=HC(SiMe(2)NC(6)H(4)-4-Me)(3); Ts(Xylyl)=HC(SiMe(2)NC(6)H(3)-3,5-Me(2))(3)], were prepared by a salt-elimination strategy. Structural, spectroscopic, and computational analyses of 9-12 shows: i) the formation of unsupported uranium-ruthenium bonds with no isocarbonyl linkages in the solid state; ii) ruthenium-carbonyl backbonding in the [Ru(η(5)-C(5)H(5))(CO)(2)](-) ions that is tempered by polarization of charge within the ruthenium fragments towards uranium; iii) closed-shell uranium-ruthenium interactions that can be classified as predominantly ionic with little covalent character. Comparison of the calculated U-Ru bond interaction energies (BIEs) of 9-12 with the BIE of [(η(5)-C(5)H(5))(3)URu(η(5)-C(5)H(5))(CO)(2)], for which an experimentally determined U-Ru bond disruption enthalpy (BDE) has been reported, suggests BDEs of approximately 150 kJ mol(-1) for 9-12.

  6. Photoinduced electron transfer in ruthenium(II)/Tin(IV) multiporphyrin arrays.

    PubMed

    Indelli, M Teresa; Chiorboli, Claudio; Ghirotti, Marco; Orlandi, Michele; Scandola, Franco; Kim, Hyun Jung; Kim, Hee-Joon

    2010-11-18

    The photophysical behavior of a series of heterometallic arrays made of a central Sn(IV) porphyrin connected, respectively, to two (SnRu(2)), four (SnRu(4)), or six (SnRu(6)) ruthenium porphyrin units has been studied in dichloromethane. Two different motifs connect the ruthenium porphyrin units to central tin porphyrin core, axial coordination via ditopic bridging ligands and/or coordination to peripheral pyridyl groups of the central porphyrin ring. A remarkable number of electron transfer processes (photoinduced charge separation and recombination processes) have been time-resolved using a combination of emission spectroscopy and fast (nanosecond) and ultrafast (femtosecond) absorption techniques. In these systems both types of molecular components can be selectively populated by light absorption. In all the arrays, the local excited states of these units (the tin porphyrin singlet excited state and the ruthenium porphyrin triplet state) are quenched by electron transfer leading to a charge-separated state where the ruthenium porphyrin unit is oxidized and the tin porphyrin unit is reduced. For each array, the two forward electron transfer processes, as well as the charge recombination process leading back to the ground state, have been kinetically resolved. The rate constants obey standard free-energy correlations with the forward processes lying in the normal free-energy regime and the back reactions in the Marcus inverted region. The comparison between the trimeric (SnRu(2)) and pentameric (SnRu(4)) arrays shows that all the electron transfer processes are faster in the latter than in the former system. This can be rationalized in terms of differences in electronic factors (due to the different connecting motifs) and driving force. In less polar solvents, such as toluene, the energy of the charge-separated states is substantially lifted, leading to a switch (from electron transfer to triplet energy transfer) in the deactivation mechanism of the excited

  7. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    SciTech Connect

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

  8. Tc-99 Ion Exchange Resin Testing

    SciTech Connect

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  9. A chelate-stabilized ruthenium(sigma-pyrrolato) complex: resolving ambiguities in nuclearity and coordination geometry through 1H PGSE and 31P solid-state NMR studies.

    PubMed

    Foucault, Heather M; Bryce, David L; Fogg, Deryn E

    2006-12-11

    Reaction of RuCl2(PPh3)3 with LiNN' (NN' = 2-[(2,6-diisopropylphenyl)imino]pyrrolide) affords a single product, with the empirical formula RuCl[(2,6-iPr2C6H3)N=CHC4H3N](PPh3)2. We identify this species as a sigma-pyrrolato complex, [Ru(NN')(PPh3)2]2(mu-Cl)2 (3b), rather than mononuclear RuCl(NN')(PPh3)2 (3a), on the basis of detailed 1D and 2D NMR characterization in solution and in the solid state. Retention of the chelating, sigma-bound iminopyrrolato unit within 3b, despite the presence of labile (dative) chloride and PPh3 donors, indicates that the chelate effect is sufficient to inhibit sigma --> pi isomerization of 3b to a piano-stool, pi-pyrrolato structure. 2D COSY, SECSY, and J-resolved solid-state 31P NMR experiments confirm that the PPh3 ligands on each metal center are magnetically and crystallographically inequivalent, and 31P CP/MAS NMR experiments reveal the largest 99Ru-31P spin-spin coupling constant (1J(99Ru,31P) = 244 +/- 20 Hz) yet measured. Finally, 31P dipolar-chemical shift spectroscopy is applied to determine benchmark phosphorus chemical shift tensors for phosphine ligands in hexacoordinate ruthenium complexes.

  10. A Di(Mu-oxo) Bridged Ruthenium Dimer.

    DTIC Science & Technology

    1992-04-01

    Tables For X-ray Crystallography, Vol. IV, pp. 99-101. Birmingham: Kynoch Press. (Present distributor Kluwer Academic Publishers, Dordrecht.) Duchamp ...8217 were taken from Cromer and Waber (1974) and Cromer (1974); the programs used were those of the CRYM Crystallographic Computing System ( Duchamp , 1964

  11. 40 CFR 86.1725-99 - Maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Maintenance. 86.1725-99 Section 86.1725-99 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Provisions for the Voluntary National Low Emission Vehicle...

  12. 40 CFR 86.1702-99 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Definitions. 86.1702-99 Section 86.1702-99 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Provisions for the Voluntary National Low Emission Vehicle...

  13. NARSTO SOS99NASH WIND PROFILER DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO SOS99NASH WIND PROFILER DATA Project Title:  NARSTO ... Platform:  Ground Station Instrument:  Wind Profiler Location:  Nashville, Tennessee Spatial ... Data Guide Documents:  SOS99Nash Wind Profiler Guide Related Data:  Southern Oxidants ...

  14. 46 CFR 111.99-3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Definitions. 111.99-3 Section 111.99-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL... control panel means a manually-operated device on the navigating bridge or in the fire control room for...

  15. 29 CFR 99.105 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS General § 99.105 Definitions. Audit finding means deficiencies which the auditor is required by § 99.510(a) to report in the..., State, or local government audit organization, which meets the general standards specified in generally...

  16. Tc-99m Labeled carrier for imaging

    DOEpatents

    Henze, Eberhard

    1984-01-01

    Novel radionuclide imaging agents, having particular application for lymphangiography are provided by non-covalently binding Tc-99m to a pharmaceutically acceptable cross-linked polysaccharide. Upon injection of the Tc-99m labeled polysaccharide into the blood stream, optimum contrast can be obtained within one hour.

  17. 29 CFR 99.310 - Financial statements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Financial statements. 99.310 Section 99.310 Labor Office of....310 Financial statements. (a) Financial statements. The auditee shall prepare financial statements... appropriate, cash flows for the fiscal year audited. The financial statements shall be for the same...

  18. 10 CFR 51.99 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false 51.99 Section 51.99 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND RELATED REGULATORY FUNCTIONS National Environmental Policy Act-Regulations Implementing Section 102(2) Final Environmental...

  19. 10 CFR 51.99 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false 51.99 Section 51.99 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND RELATED REGULATORY FUNCTIONS National Environmental Policy Act-Regulations Implementing Section 102(2) Final Environmental...

  20. 10 CFR 51.99 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false 51.99 Section 51.99 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND RELATED REGULATORY FUNCTIONS National Environmental Policy Act-Regulations Implementing Section 102(2) Final Environmental...

  1. 10 CFR 51.99 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false 51.99 Section 51.99 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND RELATED REGULATORY FUNCTIONS National Environmental Policy Act-Regulations Implementing Section 102(2) Final Environmental...

  2. 45 CFR 99.31 - Posthearing briefs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Posthearing briefs. 99.31 Section 99.31 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROCEDURE FOR HEARINGS FOR THE... fact and conclusions of law. The presiding officer shall also fix the time for reply briefs,...

  3. 14 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Definitions. 99.3 Section 99.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND... reports are normally filed during flight operations. Air defense identification zone (ADIZ) means an area...

  4. 14 CFR 99.45 - Alaska ADIZ.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification...

  5. 14 CFR 99.45 - Alaska ADIZ.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification...

  6. 14 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Definitions. 99.3 Section 99.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND... reports are normally filed during flight operations. Air defense identification zone (ADIZ) means an area...

  7. 14 CFR 99.45 - Alaska ADIZ.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification...

  8. 14 CFR 99.45 - Alaska ADIZ.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification...

  9. 14 CFR 99.45 - Alaska ADIZ.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification...

  10. 14 CFR 99.1 - Applicability.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Applicability. 99.1 Section 99.1 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... subpart prescribes rules for operating all aircraft (except for Department of Defense and law enforcement...

  11. 14 CFR 99.47 - Guam ADIZ.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND..., 145°11′21″ E; then to the point of origin. (b) Outer boundary. The area bounded by a circle with...

  12. 14 CFR 61.99 - Aeronautical experience.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience. 61.99 Section 61.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical experience. A person who applies for a recreational pilot certificate must receive and log at...

  13. 29 CFR 99.300 - Auditee responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Auditees... the schedule of expenditures of Federal awards in accordance with § 99.310. (e) Ensure that the audits... submission due date required by § 99.320(a) are granted by the cognizant or oversight agency for audit...

  14. 7 CFR 1956.99 - Exception authority.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Exception authority. 1956.99 Section 1956.99 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Farm Loan Programs and...

  15. 21 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Definitions. 99.3 Section 99.3 Food and Drugs FOOD... Definitions. (a) Agency or FDA means the Food and Drug Administration. (b) For purposes of this part, a... or market the drug or device. For purposes of this part, the term may also include the sponsor of the...

  16. 21 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Definitions. 99.3 Section 99.3 Food and Drugs FOOD... Definitions. (a) Agency or FDA means the Food and Drug Administration. (b) For purposes of this part, a... or market the drug or device. For purposes of this part, the term may also include the sponsor of the...

  17. 21 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Definitions. 99.3 Section 99.3 Food and Drugs FOOD... Definitions. (a) Agency or FDA means the Food and Drug Administration. (b) For purposes of this part, a... or market the drug or device. For purposes of this part, the term may also include the sponsor of the...

  18. 21 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Definitions. 99.3 Section 99.3 Food and Drugs FOOD... Definitions. (a) Agency or FDA means the Food and Drug Administration. (b) For purposes of this part, a... or market the drug or device. For purposes of this part, the term may also include the sponsor of the...

  19. 21 CFR 99.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Definitions. 99.3 Section 99.3 Food and Drugs FOOD... Definitions. (a) Agency or FDA means the Food and Drug Administration. (b) For purposes of this part, a... or market the drug or device. For purposes of this part, the term may also include the sponsor of the...

  20. 29 CFR 99.310 - Financial statements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Financial statements. 99.310 Section 99.310 Labor Office of....310 Financial statements. (a) Financial statements. The auditee shall prepare financial statements that reflect its financial position, results of operations or changes in net assets, and,...