Sample records for rhenium carbonyl-promoted c-s

  1. Organometallic Modeling of the Hydrodesulfurization (HDS) Process: Rhenium Carbonyl-promoted C-S Bond Cleavage and Hydrogenation of Thiophenes and Benozothiophenes

    Reynolds, Michael A. [Iowa State Univ., Ames, IA (United States)


    Organometallic modeling of the HDS process at single or multiple metal centers is one approach to better understanding the mechanism that govern commercial HDS. Therefore, we have currently been investigating the use of Re2(CO)10 as a potential model system for catalytic HDS with respect to S-binding, ring-opening, and hydrogenation of thiophenes andbenzothiophenes. We have also been investigating the use of UV-light as a method for activating thiophenic molecules towards C-S and C-H bond cleavage.

  2. Rhenium Nanochemistry for Catalyst Preparation

    Vadim G. Kessler


    Full Text Available The review presents synthetic approaches to modern rhenium-based catalysts. Creation of an active center is considered as a process of obtaining a nanoparticle or a molecule, immobilized within a matrix of the substrate. Selective chemical routes to preparation of particles of rhenium alloys, rhenium oxides and the molecules of alkyltrioxorhenium, and their insertion into porous structure of zeolites, ordered mesoporous MCM matrices, anodic mesoporous alumina, and porous transition metal oxides are considered. Structure-property relationships are traced for these catalysts in relation to such processes as alkylation and isomerization, olefin metathesis, selective oxidation of olefins, methanol to formaldehyde conversion, etc.

  3. Improved Rhenium Thrust Chambers

    O'Dell, John Scott


    Radiation-cooled bipropellant thrust chambers are being considered for ascent/ descent engines and reaction control systems on various NASA missions and spacecraft, such as the Mars Sample Return and Orion Multi-Purpose Crew Vehicle (MPCV). Currently, iridium (Ir)-lined rhenium (Re) combustion chambers are the state of the art for in-space engines. NASA's Advanced Materials Bipropellant Rocket (AMBR) engine, a 150-lbf Ir-Re chamber produced by Plasma Processes and Aerojet Rocketdyne, recently set a hydrazine specific impulse record of 333.5 seconds. To withstand the high loads during terrestrial launch, Re chambers with improved mechanical properties are needed. Recent electrochemical forming (EL-Form"TM") results have shown considerable promise for improving Re's mechanical properties by producing a multilayered deposit composed of a tailored microstructure (i.e., Engineered Re). The Engineered Re processing techniques were optimized, and detailed characterization and mechanical properties tests were performed. The most promising techniques were selected and used to produce an Engineered Re AMBR-sized combustion chamber for testing at Aerojet Rocketdyne.

  4. Rhenium/Oxygen Interactions at Elevated Temperatures

    Jacobson, Nathan; Myers, Dwight; Zhu, Dong-Ming; Humphrey, Donald


    The oxidation of pure rhenium is examined from 600-1400 C in oxygen/argon mixtures. Linear weight loss kinetics are observed. Gas pressures, flow rates, and temperatures are methodically varied to determine the rate controlling steps. The reaction at 600 and 800 C appears to be controlled by a chemical reaction step at the surface; whereas the higher temperature reactions appear to be controlled by gas phase diffusion of oxygen to the rhenium surface. Attack of the rhenium appears to be along grain boundaries and crystallographic planes.

  5. Mineral resource of the month: rhenium

    Polyak, Désirée E.


    Rhenium, a silvery-white, heat resistant metal, has increased significantly in importance since its discovery in 1925. First isolated by a team of German chemists studying platinum ore, the mineral was named for the Rhine River. From 1925 until the 1960s, only two metric tons of rhenium were produced worldwide. Since then, its uses have steadily increased, including everything from unleaded gasoline to jet engines, and worldwide annual production now tops 45 metric tons.

  6. Rhenium volatilization in waste glasses

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)


    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  7. New Motifs in Deoxydehydration: Beyond the Realms of Rhenium

    Petersen, Allan Robertson; Fristrup, Peter


    The deoxydehydration (DODH) reaction remains one of the most efficient methods of reducing the oxygen content of biomass while keeping important functionality in place. This reaction is traditionally catalysed by high-valent oxo-rhenium species. Recent research into heterogeneous rhenium-based ca......The deoxydehydration (DODH) reaction remains one of the most efficient methods of reducing the oxygen content of biomass while keeping important functionality in place. This reaction is traditionally catalysed by high-valent oxo-rhenium species. Recent research into heterogeneous rhenium......-based catalysts for DODH demonstrates their ability to rival and in some cases surpass their homogeneous counterparts. Furthermore, catalysts based on the metals molybdenum and vanadium show great potential as inexpensive alternatives to rhenium catalysts. In this Minireview, we detail the recent developments...... within the field of DODH with particular emphasis on discoveries outside the realms of rhenium....

  8. Accelerator Production and Separations for High Specific Activity Rhenium-186

    Jurisson, Silvia S. [Univ. of Missouri, Columbia, MO (United States); Wilbur, D. Scott [Univ. of Washington, Seattle, WA (United States)


    Tungsten and osmium targets were evaluated for the production of high specific activity rhenium-186. Rhenium-186 has potential applications in radiotherapy for the treatment of a variety of diseases, including targeting with monoclonal antibodies and peptides. Methods were evaluated using tungsten metal, tungsten dioxide, tungsten disulfide and osmium disulfide. Separation of the rhenium-186 produced and recycling of the enriched tungsten-186 and osmium-189 enriched targets were developed.

  9. Epitaxial Growth of Rhenium with Sputtering


    match (a = 2.76 Å) to the oxygen sublattice (a = 2.77 Å) of α-Al2O3 (0001) [2]. Re also has a reasonably high superconducting critical copyright. Keywords: Epitaxy, Rhenium, Sputtering 1. Introduction Epitaxial superconducting films of refractory metals are a promising new...than the RF sputtered films. These differences are most likely due to the fact that RF sputtering has more of an etching effect on the sample

  10. Electrodeposition of Plutonium on Rhenium Foil

    YANG; Jin-ling; YANG; Chun-li; DING; You-qian; SUN; Hong-qing


    Applying for LRIMS analysis,one of the main requirements is the production of an atomic beam(or molecular beam)with the atoms in one well defined state,i.e.,the ground state,and then the efficient excitation and ionization of the atoms.Therefore,the target nuclides must be transferred to the rhenium foil quantitatively.So the study on electrodeposistion was applied:first is the designation of electroplate

  11. Rhenium carbene complexes and their applications; Rhenium-Carben-Komplexe und ihre Anwendungen

    Hille, Claudia Heidi


    New pharmaceutically suitable metal complexes play an important role in the development of diagnostic and therapeutic agents for cancer treatment. One option concerning new radiopharmaceuticals, is the application of the rhenium isotopes {sup 186}Re and {sup 188}Re. Therefore, water soluble but at the same time stable complexes, which can be synthesized straightforward, are required. In this thesis, several synthetic pathways to such rhenium complexes bearing Nheterocyclic carbenes are presented and applicability tests of literature known complexes conducted. The selected target structures based on monocarbenes turned out to be inappropriate for use in radiopharmaceutical applications, due to their long reaction times and purification issues. Additionally, sterical and electronical effects of the carbene ligands concerning complex formation have been investigated. Possibilities of functionalization at different positions on the heterocycle as well as hydrophilic wingtips - to achieve a better stability in an aqueous media - have been examined to gain information about chemical and physical properties of the resulting complexes. Furthermore, experiments regarding the coordination of various biscarbene ligands, which provides besides the stable chelatisation additionally the possibility of varying the linking bridge, to rhenium(I/V) precursors, have been performed. Dioxo-bis-(1,1{sup '}-methylene-bis(3,3{sup '}-diisopropylimidazolium-2-ylidene)) rhenium(V )-hexafluorophosphate was synthesized via a transmetalation reaction of the corresponding silver carbene with ReOCl{sub 3}(PPh{sub 3}){sub 2} and silver hexafluorophosphate. This complex provided the basis for the first radiolabeled {sup 188}Rhenium NHC complex later on. An enhancement of the kinetic and thermodynamic stability of potential rhenium biscarbene complexes based on modifications concerning the length and character of the bridging moiety between the chelating NHC rings as well as the nature of

  12. Rhenium: a rare metal critical in modern transportation

    John, David A.


    Rhenium is a silvery-white, metallic element with an extremely high melting point (3,180 degrees Celsius) and a heat-stable crystalline structure, making it exceptionally resistant to heat and wear. Since the late 1980s, rhenium has been critical for superalloys used in turbine blades and in catalysts used to produce lead-free gasoline.

  13. First principles calculations of interstitial and lamellar rhenium nitrides

    Soto, G., E-mail: [Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, Km 107 Carretera Tijuana-Ensenada, Ensenada Baja California (Mexico); Tiznado, H.; Reyes, A.; Cruz, W. de la [Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, Km 107 Carretera Tijuana-Ensenada, Ensenada Baja California (Mexico)


    Highlights: Black-Right-Pointing-Pointer The possible structures of rhenium nitride as a function of composition are analyzed. Black-Right-Pointing-Pointer The alloying energy is favorable for rhenium nitride in lamellar arrangements. Black-Right-Pointing-Pointer The structures produced by magnetron sputtering are metastable variations. Black-Right-Pointing-Pointer The structures produced by high-pressure high-temperature are stable configurations. Black-Right-Pointing-Pointer The lamellar structures are a new category of interstitial dissolutions. - Abstract: We report here a systematic first principles study of two classes of variable-composition rhenium nitride: i, interstitial rhenium nitride as a solid solution and ii, rhenium nitride in lamellar structures. The compounds in class i are cubic and hexagonal close-packed rhenium phases, with nitrogen in the octahedral and tetrahedral interstices of the metal, and they are formed without changes to the structure, except for slight distortions of the unit cells. In the compounds in class ii, by contrast, the nitrogen inclusion provokes stacking faults in the parent metal structure. These faults create trigonal-prismatic sites where the nitrogen residence is energetically favored. This second class of compounds produces lamellar structures, where the nitrogen lamellas are inserted among multiple rhenium layers. The Re{sub 3}N and Re{sub 2}N phases produced recently by high-temperature and high-pressure synthesis belong to this class. The ratio of the nitrogen layers to the rhenium layers is given by the composition. While the first principle calculations point to higher stability for the lamellar structures as opposed to the interstitial phases, the experimental evidence presented here demonstrates that the interstitial classes are synthesizable by plasma methods. We conclude that rhenium nitrides possess polymorphism and that the two-dimensional lamellar structures might represent an emerging class of materials

  14. Rhenium, Molybdenum, Tungsten - Prospects for Production and Industrial Applications


    15. NUMBER OF PAGES 112 EOARD, Materials, Metalurgy , Structural Materials 16. PRICE CODE N/A 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19...least 75% of 1, 3, 5-triethylbenzene), which ensures an optimum combination of physical and chemical properties (isotherm of rhenium (VII) extraction...transitions. These data enabled the researchers to establish specific regularities in physical and chemical interaction of rhenium with other elements of

  15. Room-Temperature Tensile Behavior of Oriented Tungsten Single Crystals with Rhenium in Dilute Solid Solution



  16. A different 'spin' on rhenium chemistry. synthetic approaches and perspectives of 17-electron rhenium complexes.

    Zobi, Fabio


    Transition metal complexes of rhenium and technetium find wide application in nuclear medicine and the chemistry of these elements is still the focus of intense research efforts. For therapeutic and diagnostic applications, currently much attention is dedicated to the development of new targeting strategies aimed at appending the metal complexes to biological vectors (e.g. a peptide) for a site-specific delivery of the radionuclides. Advancements in radiopharmacy, however, will not only arise from the development of new targeted strategies but also from the exploration of the chemistry of these elements in their unusual oxidation states. In this respect the even number oxidation states of Re and Tc (i.e. +II, +IV and +VI) are relatively poorly understood. In particular, stable and substitutionally labile mononuclear 17-electron species of the elements (+II, d(5)) are a rarely encountered class of complexes. In this review we present our recent developments in the field of rhenium (II) chemistry with emphasis on the novel synthetic strategies we have recently introduced. We will also describe how the unique chemical and electronic properties of Re(II)-based complexes may provide a potentially new approach for applications in inorganic medicinal chemistry.

  17. Rhenium-catalysed hydroboration of aldehydes and aldimines.

    Arévalo, Rebeca; Vogels, Christopher M; MacNeil, Gregory A; Riera, Lucía; Pérez, Julio; Westcott, Stephen A


    The first examples for the rhenium-catalysed hydroboration of aldehydes, ketones and aldimines, including heteroaromatic quinoline, are reported herein. Reactions are remarkably chemoselective and tolerant of several functional groups. A wide array of rhenium complexes were efficient pre-catalysts for these hydroborations, including new low-valent complexes of the formula [Re(N-N)(CO)3(L)]X (N-N = bipy derivative, L = labile ligand/solvent, and X = [BAr(F)4](-) and [B(3,5-di-tBu-cat)2](-)), which have been characterized fully including an X-ray diffraction study for [Re(bipy)(CO)3(quin)][BAr(F)4] (2). A new silver spiroboronate ester Ag[B(3,5-di-tBu-cat)2](NCCH3)3 (3) was prepared and characterized fully, including an X-ray diffraction study, and used to make one of the new rhenium complexes.

  18. Application of Technetium and Rhenium in Nuclear Medicine

    Alberto, Roger


    Technetium and Rhenium are the two lower elements in the manganese triad. Whereas rhenium is known as an important part of high resistance alloys, technetium is mostly known as a cumbersome product of nuclear fission. It is less known that its metastable isotope 99mTc is of utmost importance in nuclear medicine diagnosis. The technical application of elemental rhenium is currently complemented by investigations of its isotope 188Re, which could play a central role in the future for internal, targeted radiotherapy. This article will briefly describe the basic principles behind diagnostic methods with radionuclides for molecular imaging, review the 99mTc-based radiopharmaceuticals currently in clinical routine and focus on the chemical challenges and current developments towards improved, radiolabeled compounds for diagnosis and therapy in nuclear medicine.

  19. Electroless plating of rhenium-nickel alloys

    Duhin, Alla [Biomaterials and Corrosion Laboratory, School of Mechanical Engineering and The Materials and Nanotechnologies Program, Tel-Aviv University, Ramat-Aviv, Tel Aviv 69978 (Israel); Inberg, Alexandra [Department of Physical Electronics, Faculty of Engineering, Tel-Aviv University, Ramat-Aviv, Tel Aviv 69978 (Israel); Eliaz, Noam, E-mail: [Biomaterials and Corrosion Laboratory, School of Mechanical Engineering and The Materials and Nanotechnologies Program, Tel-Aviv University, Ramat-Aviv, Tel Aviv 69978 (Israel); Gileadi, Eliezer [School of Chemistry, Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv, Tel Aviv 69978 (Israel)


    In this study, rhenium-nickel (Re-Ni) films were formed by electroless deposition on conductive (Cu) and non-conductive (SiO{sub 2}) substrates. Different bath compositions were evaluated, aiming to achieve high Re-content. Both sodium hypophosphite and dimethylamine-borane were used as reducing agents. Films containing up to 75 at% Re were obtained. The influence of nickel concentration in the solution on alloy composition, deposition rate and surface morphology were determined. It is shown that Ni{sup 2+} acts as a catalyst for the in situ reduction of the perrhenate ion, in a manner similar to what was proposed for electroplating of the same alloy. The rate of electroless plating is similar to that found in electroplating at an applied current density of 50 mA cm{sup -2}. While pure Re cannot be deposited from our electroless plating baths, the addition of even a very small amount of Ni{sup 2+} ions (0.25 mM) is enough to start the induced codeposition of Re. Proper selection of the bath composition can lead to fine control of the alloy thickness and its Re-content, thus making it potentially attractive for thin barrier layers.

  20. Effect of Temperature and Mole Ratio on the Synthesis Yield of Rhenium-Tetrofosmin



    Full Text Available Technetium-99m (99mTc tetrofosmin is widely used in nuclear medicine as a diagnostic agent for myocardial perfusion and as a tumor imaging agent. As a parenteral preparation it requires an evaluation of its pharmacokinetics and stability in-vivo. Since 99mTc has a short half-life and is only available in very low concentrations, it is impossible to characterize its chemical properties and presence in the body. Due to this reason, only technetium-99 (T1/2 = 5 × 105 years, which is available in macro quantities, or natural rhenium can be used for this purpose. In this study rhenium-188 (188Re tetrofosmin will be synthesized and applied, because non-radioactive Re can be easily obtained. Synthesis and radiochemical purity analysis of carrier-added 188Re-tetrofosmin were carried out as a model to study the in-vivo stability of technetium-99m tetrofosmin. Rhenium-188 was used as a tracer to identify the formation of rhenium tetrofosmin. Rhenium gluconate was synthesized first prior to the formation of rhenium tetrofosmin. The quality of labeling for both rhenium gluconate and rhenium tetrofosmin was analyzed using paper- and thin-layer chromatography, respectively. Rhenium gluconate can be synthesized with high labeling yield within 1 hour, whereas rhenium tetrofosmin was synthesized both in room temperature and in an elevated temperature with various tetrofosmin-to-rhenium mole ratios.The results showed that heating at 95oC led to a higher yield of more than 90% within 30 minutes. Rhenium tetrofosmin could be produced in high radiochemical purity using an excess of tetrofosmin with mole ratio of 2000. It is concluded that rhenium tetrofosmin could be synthesized through the formation of rhenium gluconate, and a higher yield could be obtained in a shorter time by heating process.

  1. Mechanistic Study of Oxygen Atom Transfer Catalyzed by Rhenium Compounds

    Xiaopeng Shan


    Two ionic and one neutral methyl(oxo)rhenium(V) compounds were synthesized and structurally characterized. They were compared in reactivity towards the ligands triphenylphosphane, pyridines, pyridine N-oxides. Assistance from Broensted bases was found on ligand displacement of ionic rhenium compounds as well as nucleophile assistance on oxidation of all compounds. From the kinetic data, crystal structures, and an analysis of the intermediates, a structural formula of PicH{sup +}3{sup -} and mechanisms of ligand displacement and oxidation were proposed.

  2. Investigation on oxidation states of rhenium in Re-HEDP

    WANG Wen-Jin; LUO Shun-Zhong; QIAO Jian; LIU Guo-Ping; LIU Ye-Bing


    The oxidation states of rhenium in Re-HEDP (hydroxyethylidene diphosphonate) were measured bythe methods of extraction and potentiometric titration. The oxidation state of rhenium in Re-HEDP was mostly +4valence, and the Re(Ⅳ)-HEDP was oxidized to Re( Ⅴ)-HEDP when it was titrated by I3- at pH 2.0. In the reductionsystem of Vc+Sn2+ , ReO4- was only reduced by Sn2+, but Vc was oxidized earlier than Sn2+ when it was titrated by I3.

  3. Solution and diffusion of hydrogen isotopes in tungsten-rhenium alloy

    Ren, Fei; Yin, Wen; Yu, Quanzhi; Jia, Xuejun; Zhao, Zongfang; Wang, Baotian


    Rhenium is one of the main transmutation elements forming in tungsten under neutron irradiation. Therefore, it is essential to understand the influence of rhenium impurity on hydrogen isotopes retention in tungsten. First-principle calculations were used to study the properties of hydrogen solution and diffusion in perfect tungsten-rhenium lattice. The interstitial hydrogen still prefers the tetrahedral site in presence of rhenium, and rhenium atom cannot act directly as a trapping site of hydrogen. The presence of rhenium in tungsten raises the solution energy and the real normal modes of vibration on the ground state and the transition state, compared to hydrogen in pure tungsten. Without zero point energy corrections, the presence of rhenium decreases slightly the migration barrier. It is found that although the solution energy would tend to increase slightly with the rising of the concentration of rhenium, but which does not influence noticeably the solution energy of hydrogen in tungsten-rhenium alloy. The solubility and diffusion coefficient of hydrogen in perfect tungsten and tungsten-rhenium alloy have been estimated, according to Sievert's law and harmonic transition state theory. The results show the solubility of hydrogen in tungsten agrees well the experimental data, and the presence of Re would decrease the solubility and increase the diffusivity for the perfect crystals.

  4. Catalytic Oxidation and Deoxygenation of Renewables with Rhenium Complexes

    Korstanje, T.J.; Klein Gebbink, R.J.M.


    Transformation of renewables has received major research interest in recent years, opening up completely new research areas, in particular in the field of oxidation and deoxygenation. For the oxidation reaction, rhenium complexes, in particular methyltrioxorhenium, are well known for their potential

  5. Diffusion aluminide coatings for internal surface of rhenium- and rhenium-ruthenium-containing single-crystal superalloys turbine blades: Part I

    Mubovadzhyan, S. A.; Galoyan, A. G.


    Process of formation rhenium or refractory carbides based diffusion barrier layer (coating) on internal surface of rhenium- and rhenium-ruthenium-containing single-crystal high-temperature alloys (superalloy) turbine blades, prior to diffusion aluminide coating deposition, is studied. It is shown that diffusion barrier layer is preventing deleterious secondary reaction zone formation under aluminide coating during long-term high-temperature operation. The kinetics of powder carburizing process of rhenium- and rhenium-ruthenium-containing high-temperature alloys is investigated, and conditions for carburizing these alloys are determined. The phase composition of the surface layer after carburizing is studied, and the effect of the fractional composition of a carbon-based powder mixture on the carburizing rate is determined.

  6. Polarization-Resolved Raman Spectroscopy of Rhenium Disulfide

    Chenet, Daniel; Aslan, Ozgur; Heinz, Tony; van der Zande, Arend; Hone, James


    Rhenium Disulfide (ReS2) is a layered semiconductor with each layer exhibiting a distorted 1T crystal structure. The reduced symmetry of the distorted 1T structure creates anisotropic optical and electrical properties that have been previously studied in bulk films. Herein, we demonstrate anisotropic behavior in its Raman spectra. We then correlate these vibrational modes with polarized absorption measurements in thin films in order to develop a versatile technique for determining the crystal orientation of anisotropic semiconducting thin films.

  7. What is the role of rhenium in single crystal superalloys?

    Mottura Alessandro


    Full Text Available Rhenium plays a critical role in single-crystal superalloys –its addition to first generation alloys improves creep life by a factor of at least two, with further benefits for fatigue performance. Its use in alloys such as PWA1484, CMSX-4 and Rene N5 is now widespread, and many in this community regard Re as the “magic dust”. In this paper, the latest thinking concerning the origins of the “rhenium-effect” is presented. We start by reviewing the hypothesis that rhenium clusters represent barriers to dislocation motion. Recent atom probe tomography experiments have shown that Re may instead form a solid solution with Ni at low concentrations (< 7 at.%. Density functional theory calculations indicate that, in the solid solution, short range ordering of Re may be expected. Finally, Re has been shown to diffuse slowly in the γ-Ni phase. Calculations using a semi-analytical dislocation climb/glide model based upon the work of McLean and Dyson have been used to rationalise the composition-dependence of creep deformation in these materials. All evidence points to two important factors: (i the preferred partitioning of Re to the γ phase, where dislocation activity preferentially occurs during the tertiary creep regime and (ii a retardation effect on dislocation segments at γ/γ′ interfaces, which require non-conservative climb and thus an associated vacancy flux.

  8. CVD Rhenium Engines for Solar-Thermal Propulsion Systems

    Williams, Brian E.; Fortini, Arthur J.; Tuffias, Robert H.; Duffy, Andrew J.; Tucker, Stephen P.


    Solar-thermal upper-stage propulsion systems have the potential to provide specific impulse approaching 900 seconds, with 760 seconds already demonstrated in ground testing. Such performance levels offer a 100% increase in payload capability compared to state-of-the-art chemical upper-stage systems, at lower cost. Although alternatives such as electric propulsion offer even greater performance, the 6- to 18- month orbital transfer time is a far greater deviation from the state of the art than the one to two months required for solar propulsion. Rhenium metal is the only material that is capable of withstanding the predicted thermal, mechanical, and chemical environment of a solar-thermal propulsion device. Chemical vapor deposition (CVD) is the most well-established and cost-effective process for the fabrication of complex rhenium structures. CVD rhenium engines have been successfully constructed for the Air Force ISUS program (bimodal thrust/electricity) and the NASA Shooting Star program (thrust only), as well as under an Air Force SBIR project (thrust only). The bimodal engine represents a more long-term and versatile approach to solar-thermal propulsion, while the thrust-only engines provide a potentially lower weight/lower cost and more near-term replacement for current upper-stage propulsion systems.

  9. Therapy with rhenium-186 HEDP in painful bone metastases; Schmerztherapie mit Rhenium-186 HEDP bei multiplen Knochenmetastasen

    Palmedo, H. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany); Bender, H. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany); Schomburg, A. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany); Gruenwald, F. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany); Schoeneich, G. [Klinik fuer Urologie, Univ. Bonn (Germany); Zamorra, P. [Klinik fuer Anaesthesiologie, Univ. Bonn (Germany); Reichmann, K. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany); Dierke-Dzierzon, C. [Klinik fuer Anaesthesiologie, Univ. Bonn (Germany); Mallmann, P. [Klinik fuer Gynaekologie und Geburtshilfe, Univ. Bonn (Germany); Biersack, H.J. [Klinik fuer Nuklearmedizin, Univ. Bonn (Germany)


    Aim: Therapeutic means for patients with painful bony metastases are strongly limited. In these patients, a systemic therapy with isotopes can be helpful. The aim of this study was to evaluate the efficacy of rhenium-186 HEDP for pain palliation in patients with disseminated bone metastases. Methods: 30 patients taking analgesics because of bone pain received one or more injection of 1295 MBq {sup 186}Re HEDP for pain palliation. Results: In 70% of the patients, therapy resulted in a significant reduction of pain. The average duration of pain relief was 4 weeks (1 week-2,5 months). The main side effects of therapy were a decrease of platelets (aver. 30000/{mu}l) and an increase of pain for 1-2 days (flare-phenomenon). Conclusion: Therapy with rhenium-186 HEDP can be used complementarily to analgesic therapy in patients with painful, disseminated bone metastases. (orig.) [Deutsch] Ziel: Die effiziente, medikamentoese Behandlung von Patienten mit schmerzhaften, disseminierten Knochenmetastasen stellt ein therapeutisches Problem dar. Die systemische Radionuklidtherapie kommt als Alternative in Frage. In der vorliegenden Studie wurde die Effektivitaet von Rhenium-186 HEDP zur Schmerztherapie bei disseminierten Knochenmetastasen evaluiert. Methoden: 30 Patienten, die wegen schmerzhafter Knochenmetastasen analgetisch behandelt wurden, erhielten - teilweise mehrfach - Injektionen von jeweils 1295 MBq {sup 186}Re HEDP zur Schmerzbehandlung. Ergebnisse: Bei 70% der Patienten liess sich eine Schmerzreduktion erreichen. Die Dauer des Ansprechens auf die Therapie betrug im Mittel 4 Wochen (1 Wo-2,5 Mon). Die wesentlichen Nebenwirkungen bestanden in einem geringen Abfall der Thrombozyten (durchschnittl. 30000/{mu}l) und einer kurzzeitigen Verstaerkung der Schmerzsymptomatik (Flare-Effekt). Schlussfolgerung: Bei Patienten mit schmerzhaften, disseminierten Knochenmetastasen kann die Schmerztherapie mit Rhenium-186 HEDP komplementaer zur medikamentoesen Therapie eingesetzt werden

  10. Effect of rhenium addition on tungsten fuzz formation in helium plasmas

    Khan, A.; De Temmerman, G.; Morgan, T. W.; M. B. Ward,


    The effect of the addition of rhenium to tungsten on the formation of a nanostructure referred to as ‘fuzz’ when exposed to helium plasmas at fusion relevant ion fluxes was investigated in the Magnum and Pilot PSI devices at the FOM Institute DIFFER. The effect rhenium had on fuzz growth was seen to

  11. Cationic Tri-Rhenium Rafts on gamma-Alumina: Characterization by X-ray Absorption Spectroscopy

    Koningsberger, D.C.; Fung, A.S.; Tooley, P.A.; Kelley, M.J.; Gates, B.C.


    Rhenium surface species, derived by treating [H,Re,(CO),,] adsorbed on y-A1203 in hydrogen at 400 'C, formed extremely small surface grouping of rhenium atoms having an average Re-Re coordination number of 2, as determined by extended X-ray absorption fine structure (EXAFS) spectroscopy. Results of

  12. Spectroscopic Characterization of a Monomeric, Cyclopentadienyl-Based Rhenium(V) Dioxo Complex

    Raju, Suresh; Jastrzebski, Johann T. B. H.; Lutz, Martin


    spectrometry. (Cpttt)ReO2 is shown to be the primary product of reduction of the rhenium(VII) complex (Cpttt)ReO3 with PPh3 and demonstrated to react with ethylene glycol significantly faster than its dimeric counterpart, supporting its role as an intermediate in rhenium-catalyzed deoxydehydration reactions....

  13. Rhenium-Catalyzed Dehydration of Nonbenzylic and Terpene Alcohols to Olefins

    Korstanje, T.J.; de Waard, E.F.; Jastrzebski, J.T.B.H.; Klein Gebbink, R.J.M.


    With the increasing importance of research into biomass as a feedstock for the chemical industry, new methods to reduce the oxygen content of biomass are required. Here, we present our progress in the field of the dehydration reaction, using various rhenium-based catalysts, with rhenium(VII) oxide a

  14. Effect of rhenium addition on tungsten fuzz formation in helium plasmas

    Khan, Aneeqa; De Temmerman, Gregory; Morgan, Thomas W.; Ward, Michael B.


    The effect of the addition of rhenium to tungsten on the formation of a nanostructure referred to as 'fuzz' when exposed to helium plasmas at fusion relevant ion fluxes was investigated in the Magnum and Pilot PSI devices at the FOM Institute DIFFER. The effect rhenium had on fuzz growth was seen to be dependent on time, temperature and flux. Initial fuzz growth was seen to be highly dependent on grain orientation, with rhenium having little effect. Once the fuzz was fully developed, the effect of grain orientation disappeared and the rhenium had an inhibiting effect on growth. This could be beneficial for inhibiting fuzz growth in a future fusion reactor, where transmutation of tungsten to rhenium is expected. It also appears that erosion or annealing of the fuzz is limiting growth of fuzz at higher temperatures in the range of ∼1340 °C.

  15. Effect of rhenium addition on tungsten fuzz formation in helium plasmas

    Khan, Aneeqa, E-mail: [School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL (United Kingdom); De Temmerman, Gregory [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046 - 13067 St Paul Lez Durance Cedex (France); Morgan, Thomas W. [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Partner in the Trilateral Euregio Cluster, Eindhoven (Netherlands); Ward, Michael B. [Institute for Materials Research, School of Chemical Process Engineering, University of Leeds, Leeds, LS2 9JT (United Kingdom)


    The effect of the addition of rhenium to tungsten on the formation of a nanostructure referred to as ‘fuzz’ when exposed to helium plasmas at fusion relevant ion fluxes was investigated in the Magnum and Pilot PSI devices at the FOM Institute DIFFER. The effect rhenium had on fuzz growth was seen to be dependent on time, temperature and flux. Initial fuzz growth was seen to be highly dependent on grain orientation, with rhenium having little effect. Once the fuzz was fully developed, the effect of grain orientation disappeared and the rhenium had an inhibiting effect on growth. This could be beneficial for inhibiting fuzz growth in a future fusion reactor, where transmutation of tungsten to rhenium is expected. It also appears that erosion or annealing of the fuzz is limiting growth of fuzz at higher temperatures in the range of ∼1340 °C.

  16. The Marine Geochemistry of Rhenium, Iridium and Platinum


    in the boundary clay, and proposed that this was the result of the impact of a 10 km meteorite with the Earth (Alvarez et al. 1980). Subsequently, Ir...Esser, B. K. (1991). Osmium Isotope Geochemistry of Terrigenous and Marine Sediments. PhD thesis, Yale University. Felitsyn, S. B. and P. A. Vaganov...C. E. (1990). Rhenium- Osmium Isotope Geochemistry of the Mantle, PhD Thesis, Yale University. McCallum, M. E., R. R. Loucks, R. R. Carlson, E. F

  17. Ultra-small rhenium clusters supported on graphene

    Miramontes, Orlando; Bonafé, Franco; Santiago, Ulises; Larios-Rodriguez, Eduardo; Velázquez-Salazar, Jesús J.; Mariscal, Marcelo M.; Yacaman, Miguel José


    The adsorption of very small rhenium clusters (2 – 13 atoms) supported on graphene was studied with high annular dark field - scanning transmission electron microscopy (HAADF-STEM). The atomic structure of the clusters was fully resolved with the aid of density functional calculations and STEM simulations. It was found that octahedral and tetrahedral structures work as seeds to obtain more complex morphologies. Finally, a detailed analysis of the electronic structure suggested that a higher catalytic effect can be expected in Re clusters when adsorbed on graphene than in isolated ones. PMID:25721176

  18. Plutonium ion emission from carburized rhenium mass spectrometer filaments

    Kelley, J.M.; Robertson, D.M.


    Physicochemical processes important to the application of thermal emission mass spectrometry were identified and clarified. Effects of filament carbon concentration and temperature on plutonium ion emissions from a carburized rhenium filament were determined. Filament carbon concentration profoundly affected the appearance and duration of an ion signal. A useful ion signal was produced only when the carbon saturation temperature of the filament was exceeded, at which point first-order kinetics were either achieved or closely approached. This paper explains observed ion emission behavior in terms of pausible carbothermic reduction reactions and carbon diffusion processes that direct the course of those reactions. 31 references, 5 figures.

  19. Molecular Engineering of Technetium and Rhenium Based Radiopharmaceuticals

    Zubieta, J.


    The research was based on the observation that despite the extraordinarily rich coordination chemistry of technetium and rhenium and several notable successes in reagent design, the extensive investigations by numerous research groups on a variety of N{sub 2}S{sub 2} and N{sub 3}S donor type ligands and on HYNIC have revealed that the chemistries of these ligands with Tc and Re are rather complex, giving rise to considerable difficulties in the development of reliable procedures for the development of radiopharmaceutical reagents.

  20. Clustering of transmutation elements tantalum, rhenium and osmium in tungsten in a fusion environment

    You, Yu-Wei; Kong, Xiang-Shan; Wu, Xuebang; Liu, C. S.; Fang, Q. F.; Chen, J. L.; Luo, G.-N.


    The formation of transmutation solute-rich precipitates has been reported to seriously degrade the mechanical properties of tungsten in a fusion environment. However, the underlying mechanisms controlling the formation of the precipitates are still unknown. In this study, first-principles calculations are therefore performed to systemically determine the stable structures and binding energies of solute clusters in tungsten consisting of tantalum, rhenium and osmium atoms as well as irradiation-induced vacancies. These clusters are known to act as precursors for the formation of precipitates. We find that osmium can easily segregate to form clusters even in defect-free tungsten alloys, whereas extremely high tantalum and rhenium concentrations are required for the formation of clusters. Vacancies greatly facilitate the clustering of rhenium and osmium, while tantalum is an exception. The binding energies of vacancy-osmium clusters are found to be much higher than those of vacancy-tantalum and vacancy-rhenium clusters. Osmium is observed to strongly promote the formation of vacancy-rhenium clusters, while tantalum can suppress the formation of vacancy-rhenium and vacancy-osmium clusters. The local strain and electronic structure are analyzed to reveal the underlying mechanisms governing the cluster formation. Employing the law of mass action, we predict the evolution of the relative concentration of vacancy-rhenium clusters. This work presents a microscopic picture describing the nucleation and growth of solute clusters in tungsten alloys in a fusion reactor environment, and thereby explains recent experimental phenomena.

  1. Ambient aging of rhenium filaments used in thermal ionization mass spectrometry: Growth of oxo-rhenium crystallites and anti-aging strategies

    Joseph M. Mannion


    Full Text Available Degassing is a common preparation technique for rhenium filaments used for thermal ionization mass spectrometric analysis of actinides, including plutonium. Although optimization studies regarding degassing conditions have been reported, little work has been done to characterize filament aging after degassing. In this study, the effects of filament aging after degassing were explored to determine a “shelf-life” for degassed rhenium filaments, and methods to limit filament aging were investigated. Zone-refined rhenium filaments were degassed by resistance heating under high vacuum before exposure to ambient atmosphere for up to 2 months. After degassing the nucleation and preferential growth of oxo-rhenium crystallites on the surface of polycrystalline rhenium filaments was observed by atomic force microscopy and scanning electron microscopy (SEM. Compositional analysis of the crystallites was conducted using SEM-Raman spectroscopy and SEM energy dispersive X-ray spectroscopy, and grain orientation at the metal surface was investigated by electron back-scatter diffraction mapping. Spectra collected by SEM-Raman suggest crystallites are composed primarily of perrhenic acid. The relative extent of growth and crystallite morphology were found to be grain dependent and affected by the dissolution of carbon into filaments during annealing (often referred to as carbonization or carburization. Crystallites were observed to nucleate in region specific modes and grow over time through transfer of material from the surface. Factors most likely to affect the rates of crystallite growth include rhenium substrate properties such as grain size, orientation, levels of dissolved carbon, and relative abundance of defect sites; as well as environmental factors such as length of exposure to oxygen and relative humidity. Thin (∼180 nm hydrophobic films of poly(vinylbenzyl chloride were found to slow the growth of oxo-rhenium crystallites on the filament

  2. A well-defined rhenium(VII) olefin metathesis catalyst

    Toreki, R.; Schrock, R.R. (Massachusetts Institute of Technology, Cambridge (USA))


    Molybdenum tungsten, and rhenium are the three most active metals in classical olefin metathesis systems. Molybdenum (VI){sup 2} and tungsten(VI){sup 3} alkylidene complexes of the type M-(CHR{prime})(NAr)(OR){sub 2} (Ar = 2,6-C{sub 6}H{sub 3}-i-Pr{sub 2}) have been shown to be well-behaved olefin metathesis catalysts with an activity that can be controlled through the choice of OR. Although several rhenium alkylidene complexes have been reported, none has shown any confirmable metathesis activity, even toward strained cyclic olefins such as norbornene. Since Re{triple bond}CR{double prime} and M{double bond}NR{double prime} (M = Mo or W) can be regarded as isoelectronic units, plausible candidates as olefin metathesis catalysts are complexes of the type Re(CHR{prime})(CR{double prime})(OR){sub 2}. The authors report here that such a complex in which OR = OCMe(CF{sub 3}){sub 2} is a well-behaved olefin metathesis catalyst.

  3. Ultrahigh Yield Strength Rhenium for High-Performance Combustion Chambers Project

    National Aeronautics and Space Administration — The state-of-the-art material system for high-performance radiation-cooled liquid rocket engines is iridium/rhenium manufactured by chemical vapor deposition (CVD)....

  4. The role of coordination chemistry in the development of copper and rhenium radiopharmaceuticals.

    Donnelly, Paul S


    There are several isotopes of copper and rhenium that are of interest in the development of new molecular imaging or radiotherapeutic agents. This perspective article highlights the role of coordination chemistry in the design of copper and rhenium radiopharmaceuticals engineered to selectively target tissue of interest such as cancer cells or pathological features associated with Alzheimer's disease. The coordination chemistry of copper bis(thiosemicarbazone) derivatives and copper macrocyclic complexes is discussed in terms of their potential application as targeted positron emission tomography tracers for non-invasive diagnostic imaging. A range of rhenium complexes with different ligands with rhenium in different oxidation states are introduced and their potential to be translated to new radiotherapeutic agents discussed.

  5. Evaluation of rhenium carbide as a prospective material for hard coating

    Soto, G., E-mail:; Tiznado, H.; Diaz, J.A.; Samano, E.C.; Reyes-Serrato, A.


    The literature reveals that interstitial alloys based on rhenium as a precursor might be extremely hard, becoming suitable to be used as hard coatings. In this work, we have produced rhenium carbide (ReC{sub x}) films by the reactive pulsed laser deposition method. Nanoindentation has been performed to estimate hardness. The maximum hardness value for ReC{sub x} films resulted to be 22.5 GPa. We found no evidence that ReC{sub x} films have hardness, or plasticity, higher than competitive hard coating materials. Our results and the fact that rhenium is expensive and scarce, suggest that preceding reports are overoptimistic on the prospective use of rhenium carbide as hard coatings.

  6. Separation of rhenium from molybdenum, tungsten, vanadium, platinum metals and other elements by reduction and solvent extraction.

    Yatirajam, V; Kakkar, L R


    Reduction in 1 M H(2)SO(4) with liquid zinc amalgam and extraction with isopentanol from 3M H(2)SO(4), separates rhenium from almost all the interfering elements of importance in rhenium determination. The small amounts of Mo, U, Fe and Ru still accompanying rhenium are removed by the thiocyanate-pentyl acetate or the oxine-chloroform extraction. The method is simple, rapid and of very wide applicability. It is particularly useful in the determination of rhenium in various alloys and tungsten-containing samples.

  7. Hemoglobin C, S-C, and E Diseases

    ... Anemia Vitamin Deficiency Anemia Anemia of Chronic Disease Aplastic Anemia Autoimmune Hemolytic Anemia Sickle Cell Disease Hemoglobin C, S- ... Anemia Vitamin Deficiency Anemia Anemia of Chronic Disease Aplastic Anemia Autoimmune Hemolytic Anemia Sickle Cell Disease Hemoglobin C, S- ...

  8. Lattice Dynamics of the Rhenium and Technetium Dichalcogenides

    Wolverson, Daniel; Hart, Lewis S.


    The rhenium and technetium dichalcogenides are layered van der Waals semiconductors which show a large number of Raman-active zone-centre phonon modes as a result of their unusually large unit cells and deviation from hexagonal symmetry. They thus offer the possibility of introducing in-plane anisotropy into composite heterostructures based on van der Waals materials, and Raman spectroscopy is generally used to determine their in-plane orientation. We show that first-principles calculations give a good description of the lattice dynamics of this family of materials and thus predict the zone-centre phonon frequencies and Raman activities of TcS2. We consider the distribution of the phonon modes in frequency and their atomic displacements and give a unified understanding of the phonon frequencies and Raman spectra of ReS2, TcS2 and ReSe2 in terms of the scaling of Raman frequency with the chalcogen mass.

  9. Iridium-Coated Rhenium Radiation-Cooled Rockets

    Reed, Brian D.; Biaglow, James A.; Schneider, Steven J.


    Radiation-cooled rockets are used for a range of low-thrust propulsion functions, including apogee insertion, attitude control, and repositioning of satellites, reaction control of launch vehicles, and primary propulsion for planetary space- craft. The key to high performance and long lifetimes for radiation-cooled rockets is the chamber temperature capability. The material system that is currently used for radiation-cooled rockets, a niobium alloy (C103) with a fused silica coating, has a maximum operating temperature of 1370 C. Temperature limitations of C103 rockets force the use of fuel film cooling, which degrades rocket performance and, in some cases, imposes a plume contamination issue from unburned fuel. A material system composed of a rhenium (Re) substrate and an iridium (Ir) coating has demonstrated operation at high temperatures (2200 C) and for long lifetimes (hours). The added thermal margin afforded by iridium-coated rhenium (Ir/Re) allows reduction or elimination of fuel film cooling. This, in turn, leads to higher performance and cleaner spacecraft environments. There are ongoing government- and industry-sponsored efforts to develop flight Ir/ Re engines, with the primary focus on 440-N, apogee insertion engines. Complementing these Ir/Re engine development efforts is a program to address specific concerns and fundamental characterization of the Ir/Re material system, including (1) development of Ir/Re rocket fabrication methods, (2) establishment of critical Re mechanical properly data, (3) development of reliable joining methods, and (4) characterization of Ir/Re life-limiting mechanisms.

  10. Endocavitary treatment of craniopharyngioma cysts by 186-rhenium. Traitement endocavitaire par le rhenium 186 des kystes de craniopharyngiomes

    Berenger, N.; Lebtahi, R.; Piketty, M.L.; Merienne, L.; Turak, B.; Bok, R.; Askienazy, S. (Hopital Sainte-Anne, 75 - Paris (France)); Munari, C. (Centre Hospitalier Universitaire, 38 - Grenoble (France))


    Forty-three patients with craniopharyngioma cysts were treated by intracystic injection of 186-rhenium. Leakage of colloid isotope into the CSF spaces during the ''test'' or ''therapeutic'' injection was detected by scintigraphic follow-up (15 cases/58 intracystic injections). In fact the physical characteristics of [sup 186]Re are well adapted to the requirements of treatment and, with the gamma emission, also allows early detection of leakage, avoiding irradiation of neighbouring structures. Follow-up studies revealed that craniopharyngioma cysts were effectively treated, with cessation of fluid formation, progressive shrinkage of the cysts leading to total disappearance in 14 cases (10-156 months, mean 52.5) and a considerable decrease in 13 cases (5-53 months, mean 23).

  11. New leads for fragment-based design of rhenium/technetium radiopharmaceutical agents

    Alice Brink


    Full Text Available Multiple possibilities for the coordination of fac-[Re(CO3(H2O3]+ to a protein have been determined and include binding to Asp, Glu, Arg and His amino-acid residues as well as to the C-terminal carboxylate in the vicinity of Leu and Pro. The large number of rhenium metal complex binding sites that have been identified on specific residues thereby allow increased target identification for the design of future radiopharmaceuticals. The core experimental concept involved the use of state-of-art tuneable synchrotron radiation at the Diamond Light Source to optimize the rhenium anomalous dispersion signal to a large value (f′′ of 12.1 electrons at its LI absorption edge with a selected X-ray wavelength of 0.9763 Å. At the Cu Kα X-ray wavelength (1.5418 Å the f′′ for rhenium is 5.9 electrons. The expected peak-height increase owing to the optimization of the Re f′′ was therefore 2.1. This X-ray wavelength tuning methodology thereby showed the lower occupancy rhenium binding sites as well as the occupancies of the higher occupancy rhenium binding sites.

  12. Chloroform Aided Extraction Spectrophotometric Determination of Rhenium Using Thiocyanate Complexing Agent

    E. Keshavarz Alamdari; S.K. Sadrnezhaad; Z. Mos-hefi Shabestari


    A new technique is developed for quantitative determination of rhenium in aqueous media containing molybdenum,iron and copper ions. The method seems easier and more accurate than the traditional ones. It consists of the formation of rhenium thiocyanate complex, which is extracted with chloroform at the presence of hydrochloric acid.This complex is a highly visible light absorbent that can easily be detected with the aid of a spectrophotometer. The maximum absorbance (λmax) observed for this complex was in the visible range of 430~435 nm. The experimental results showed that in a concentration range from 0.5~8 mg/L, the absorbance behavior of the rhenium thiocyanate complex is followed to the Beer-Lambert law.

  13. Nonlinear Saturable and Polarization-induced Absorption of Rhenium Disulfide

    Cui, Yudong; Lu, Feifei; Liu, Xueming


    Monolayer of transition metal dichalcogenides (TMDs), with lamellar structure as that of graphene, has attracted significant attentions in optoelectronics and photonics. Here, we focus on the optical absorption response of a new member TMDs, rhenium disulphide (ReS2) whose monolayer and bulk forms have the nearly identical band structures. The nonlinear saturable and polarization-induced absorption of ReS2 are investigated at near-infrared communication band beyond its bandgap. It is found that the ReS2-covered D-shaped fiber (RDF) displays the remarkable polarization-induced absorption, which indicates the different responses for transverse electric (TE) and transverse magnetic (TM) polarizations relative to ReS2 plane. Nonlinear saturable absorption of RDF exhibits the similar saturable fluence of several tens of μJ/cm2 and modulation depth of about 1% for ultrafast pulses with two orthogonal polarizations. RDF is utilized as a saturable absorber to achieve self-started mode-locking operation in an Er-doped fiber laser. The results broaden the operation wavelength of ReS2 from visible light to around 1550 nm, and numerous applications may benefit from the anisotropic and nonlinear absorption characteristics of ReS2, such as in-line optical polarizers, high-power pulsed lasers, and optical communication system.

  14. Rhenium uptake and distribution in phaeophyceae macroalgae, Fucus vesiculosus.

    Racionero-Gómez, B; Sproson, A D; Selby, D; Gröcke, D R; Redden, H; Greenwell, H C


    Owing to Rhenium (Re) having no known biological role, it is not fully understood how Re is concentrated in oil kerogens. A commonly held assumption is that Re is incorporated into decomposing biomass under reducing conditions. However, living macroalgae also concentrate Re to several orders of magnitude greater than that of seawater. This study uses Fucus vesiculosus to assess Re uptake and its subsequent localization in the biomass. It is demonstrated that the Re abundance varies within the macroalgae and that Re is not located in one specific structure. In F. vesiculosus, the uptake and tolerance of Re was evaluated via tip cultures grown in seawater of different Re(VII) compound concentrations (0-7450 ng g(-1)). A positive correlation is shown between the concentration of Re-doped seawater and the abundance of Re accumulated in the tips. However, significant differences between Re(VII) compounds are observed. Although the specific cell structures where the Re is localized is not known, our findings suggest that Re is not held within chloroplasts or cytoplasmic proteins. In addition, metabolically inactivated F. vesiculosus does not accumulate Re, which indicates that Re uptake is via syn-life bioadsorption/bioaccumulation and that macroalgae may provide a source for Re phytomining and/or bioremediation.

  15. Graphite-Conjugated Rhenium Catalysts for Carbon Dioxide Reduction

    Oh, Seokjoon; Gallagher, James R.; Miller, Jeffrey T.; Surendranath, Yogesh


    Condensation of fac-Re(5,6-diamino-1,10-phenanthroline)(CO)(3)Cl to o-quinone edge defects on graphitic carbon surfaces generates graphite-conjugated rhenium (GCC-Re) catalysts that are highly active for CO2 reduction to CO in acetonitrile electrolyte. X-ray photo-electron and X-ray absorption spectroscopies establish the formation of surface-bound Re centers with well-defined coordination environments. GCC-Re species on glassy carbon surfaces display catalytic currents greater than 50 mA cm(-2) with 96 +/- 3% Faradaic efficiency for CO production. Normalized for the number of Re active sites, GCC-Re catalysts exhibit higher turnover frequencies than that of a soluble molecular analogue, fac-Re(1,10-phenanthroline)(CO)(3)Cl, and turnover numbers greater than 12,000. In contrast to the molecular analogue, GCC-Re surfaces display a Tafel slope of 150 mV/decade, indicative of a catalytic mechanism involving rate-limiting one-electron transfer. This work establishes graphite conjugation as a powerful strategy for generating well-defined, tunable, heterogeneous electrocatalysts on ubiquitous graphitic carbon surfaces.

  16. Titanium alloyed with rhenium by selective laser melting

    Chlebus, Edward; Kuźnicka, Bogumiła, E-mail:; Dziedzic, Robert; Kurzynowski, Tomasz


    The paper presents results of processing Ti–Re alloys by consolidating mixtures of powders of both metals with the use of selective laser melting (SLM). Ti-based alloys containing 0.5, 1.0 and 1.5 at% Re were obtained in this way. Optimum process parameters were determined by accepting the criterion of minimum porosity of manufactured parts and maximum effectiveness of dissolving Re particles in molten Ti. Density of the SLM-processed parts reached over 99.9% and 90–85% of Re powder (by volume) was dissolved. The effects of Re content on the microstructure and mechanical properties of SLM-processed parts in as-built condition were investigated. Light microscopy and X-ray diffraction examinations revealed that rhenium changed the microstructure of CP-Ti lath-type α′ martensite to acicular-shaped by lowering the temperature of martensitic transformation. A very intensive effect of strengthening titanium by the addition of small amounts of Re was found, due to α′-lattice distortion and grain refinement. Alloying with 1.5 at% Re made it possible to obtain mechanical properties similar to those of the SLM-processed Ti6Al4V alloy in as-built condition.

  17. Nonlinear Saturable and Polarization-induced Absorption of Rhenium Disulfide

    Cui, Yudong; Lu, Feifei; Liu, Xueming


    Monolayer of transition metal dichalcogenides (TMDs), with lamellar structure as that of graphene, has attracted significant attentions in optoelectronics and photonics. Here, we focus on the optical absorption response of a new member TMDs, rhenium disulphide (ReS2) whose monolayer and bulk forms have the nearly identical band structures. The nonlinear saturable and polarization-induced absorption of ReS2 are investigated at near-infrared communication band beyond its bandgap. It is found that the ReS2-covered D-shaped fiber (RDF) displays the remarkable polarization-induced absorption, which indicates the different responses for transverse electric (TE) and transverse magnetic (TM) polarizations relative to ReS2 plane. Nonlinear saturable absorption of RDF exhibits the similar saturable fluence of several tens of μJ/cm2 and modulation depth of about 1% for ultrafast pulses with two orthogonal polarizations. RDF is utilized as a saturable absorber to achieve self-started mode-locking operation in an Er-doped fiber laser. The results broaden the operation wavelength of ReS2 from visible light to around 1550 nm, and numerous applications may benefit from the anisotropic and nonlinear absorption characteristics of ReS2, such as in-line optical polarizers, high-power pulsed lasers, and optical communication system. PMID:28053313

  18. Tungsten-rhenium thin film thermocouples for SiC-based ceramic matrix composites

    Tian, Bian; Zhang, Zhongkai; Shi, Peng; Zheng, Chen; Yu, Qiuyue; Jing, Weixuan; Jiang, Zhuangde


    A tungsten-rhenium thin film thermocouple is designed and fabricated, depending on the principle of thermal-electric effect caused by the high temperature. The characteristics of thin film thermocouples in different temperatures are investigated via numerical analysis and analog simulation. The working mechanism and thermo-electric features of the thermocouples are analyzed depending on the simulation results. Then the thin film thermocouples are fabricated and calibrated. The calibration results show that the thin film thermocouples based on the tungsten-rhenium material achieve ideal static characteristics and work well in the practical applications.

  19. Influence of ligand structure on anticancer and antioxidant properties of rhenium cluster compounds

    I. V. Leus


    Full Text Available Under the model growth of T8 Guerin’s carcinoma in rats we studied the anticancer activity of the system rhenium-platinum, which includes cis-dicarboxylates of rhenium (III with different alkyl ligands, erythrocytes number and its morphological structure, erythrocytic stability, blood haemoglobin concentration, catalase activity and concentration of TBA-active products in the rats blood plasma. The renium-platinum system had considerable antioxidat effect and prevented the growth of tumour, that was maximal for a compound with the pivalate ligand.

  20. Novel rhenium gasket design for nuclear resonant inelastic x-ray scattering at high pressure.

    Tanis, Elizabeth A; Giefers, Hubertus; Nicol, Malcolm F


    For the first time, a highly absorbing element, rhenium, has been proven to be a strong, reliable, and safe gasket material for achieving high pressure in nuclear resonant inelastic x-ray scattering (NRIXS) experiments. Rhenium foil was cut into rectangular slices and in order to reduce absorption, the elevated imprint due to preindenting of the gasket is removed using electrical discharge machining. By utilizing this novel gasket design, transmission losses were mitigated while performing NRIXS experiments conducted on the 119Sn and 57Fe Mössbauer isotopes.

  1. Revised Atomistic Models of the Crystal Structure of C-S-H with high C/S Ratio

    Kovačević, Goran; Nicoleau, Luc; Nonat, André; Veryazov, Valera


    The atomic structure of calcium-silicate-hydrate (C1.67-S-Hx) has been studied. Atomistic C-S-H models suggested in our previous study have been revised in order to perform a direct comparison of energetic stability of the different structures. An extensive set of periodic structures of C-S-H with variation of water content was created, and then optimized using molecular dynamics with reactive force field ReaxFF and quantum chemical semiempirical method PM6. All models show organization of water molecules inside the structure of C-S-H. The new geometries of C-S-H, reported in this paper, show lower relative energy with respect to the geometries from the original definition of C-S-H models. Model that corresponds to calcium enriched tobermorite structure has the lowest relative energy and the density closest to the experimental values.

  2. Natural variations in the rhenium isotopic composition of meteorites

    Liu, R.; Hu, L.; Humayun, M.


    Rhenium is an important element with which to test hypotheses of isotope variation. Historically, it has been difficult to precisely correct the instrumental mass bias in thermal ionization mass spectrometry. We used W as an internal standard to correct mass bias on the MC-ICP-MS, and obtained the first precise δ187Re values ( ±0.02‰, 2SE) for iron meteorites and chondritic metal. Relative to metal from H chondrites, IVB irons are systematically higher in δ187Re by 0.14 ‰. δ187Re for other irons are similar to H chondritic metal, although some individual samples show significant isotope fractionation. Since 185Re has a high neutron capture cross section, the effect of galactic cosmic-ray (GCR) irradiation on δ187Re was examined using correlations with Pt isotopes. The pre-GCR irradiation δ187Re for IVB irons is lower, but the difference in δ187Re between IVB irons and other meteoritic metal remains. Nuclear volume-dependent fractionation for Re is about the right magnitude near the melting point of iron, but because of the refractory and compatible character of Re, a compelling explanation in terms of mass-dependent fractionation is elusive. The magnitude of a nucleosynthetic s-process deficit for Re estimated from Mo and Ru isotopes is essentially unresolvable. Since thermal processing reduced nucleosynthetic effects in Pd, it is conceivable that Re isotopic variations larger than those in Mo and Ru may be present in IVBs since Re is more refractory than Mo and Ru. Thus, the Re isotopic difference between IVBs and other irons or chondritic metal remains unexplained.

  3. Synthesis, crystal structure and magnetic properties of new indium rhenium and scandium rhenium oxides, In 6ReO 12 and Sc 6ReO 12

    Mikhailova, D.; Ehrenberg, H.; Fuess, H.


    The new complex indium rhenium and scandium rhenium oxides, In 6ReO 12 and Sc 6ReO 12, have been synthesized as single phases in sealed silica tubes and by high-pressure high-temperature syntheses, and their crystal structures have been determined by single crystal X-ray diffraction.The compounds crystallize in a rhombohedral structure related to the distorted fluorite structure like Ln 6ReO 12 for some rare earth elements, S. G.: R-3, Z=3, aH= 9.248(2) Å, cH=8.720(2) Å for Sc 6ReO 12 and aH=9.492(1) Å, cH=8.933(1) Å for In 6ReO 12. A maximum in magnetization is observed for Sc 6ReO 12 at T( Mmax)=1.89(2) K, whereas ferromagnetic ordering is found for In 6ReO 12 by a pronounced increase in the temperature dependence of magnetization at TC=7.5(5) K. The magnetic moment per rhenium ion in In 6ReO 12 and Sc 6ReO 12 is 0.84(1) and 0.65(1) μB, respectively, derived from the paramagnetic regions.

  4. Cyclopentadienyl Rhenium (Technetium) Tricarbonyl Complexes Integrated in Estrogen Receptor Ligands for ER+ Tumor Imaging


    Oxidation to the N-oxide 38 with peroxy acid, with subsequent rearrangement provides the alcohol 39. Treatment of 39 with triflic anhydride in...anionic monodentate ligand is bromide for the pyridyl-imine rhenium tricarbonyl bromide (PIRB VI) system. A nomenclature of PIRB ligands is based

  5. Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

    McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A


    The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

  6. 2 x 2 Polyethylene Reflected and Moderated Highly Enriched Uranium System with Rhenium

    A. Nichole Ellis; Jesson Hutchinson; John D. Bess; Dmitry N. Polyakov; Evgeny S. Glushkov; Alexey E. Glushkov


    The 2 × 2 array HEU-Re experiment was performed on the Planet universal critical assembly machine on November 4th, 2003 at the Los Alamos Critical Experiments Facility (LACEF) at Los Alamos National Laboratory (LANL). For this experiment, there were 10 ½ units, each full unit containing four HEU foils and two rhenium foils. The top unit contained only two HEU foils and two rhenium foils. A total of 42 HEU foils were used for this experiment. Rhenium is a desirable cladding material for space nuclear power applications. This experiment consisted of HEU foils interleaved with rhenium foils and is moderated and reflected by polyethylene plates. A unit consisted of a polyethylene plate, which has a recess for rhenium foils, and four HEU foils in a single layer in the top recess of each polyethylene plate. The Planet universal criticality assembly machine has been previously used in experiments containing HEU foils interspersed with SiO2 (HEU-MET-THERM-001), Al (HEU-MET-THERM-008), MgO (HEU-MET-THERM-009), Gd foils (HEU-MET-THERM-010), 2 × 2 × 26 Al (HEU-MET-THERM-012), Fe (HEU-MET-THERM-013 and HEU-MET-THERM-015), 2 × 2 × 23 SiO2 (HEU-MET-THERM-014), 2 × 2 × 11 hastalloy plates (HEU-MET-THERM-016), and concrete (HEU-MET-THERM-018). The 2 × 2 array of HEU-Re is considered acceptable for use as a benchmark critical experiment.

  7. Optical and Chemical Properties of Mixed-valent Rhenium Oxide Films Synthesized by Reactive DC Magnetron Sputtering



  8. Testing of electroformed deposited iridium/powder metallurgy rhenium rockets

    Reed, Brian D.; Dickerson, Robert


    High-temperature, oxidation-resistant chamber materials offer the thermal margin for high performance and extended lifetimes for radiation-cooled rockets. Rhenium (Re) coated with iridium (Ir) allow hours of operation at 2200 C on Earth-storable propellants. One process for manufacturing Ir/Re rocket chambers is the fabrication of Re substrates by powder metallurgy (PM) and the application of Ir coatings by using electroformed deposition (ED). ED Ir coatings, however, have been found to be porous and poorly adherent. The integrity of ED Ir coatings could be improved by densification after the electroforming process. This report summarizes the testing of two 22-N, ED Ir/PM Re rocket chambers that were subjected to post-deposition treatments in an effort to densify the Ir coating. One chamber was vacuum annealed, while the other chamber was subjected to hot isostatic pressure (HIP). The chambers were tested on gaseous oxygen/gaseous hydrogen propellants, at mixture ratios that simulated the oxidizing environments of Earth-storable propellants. ne annealed ED Ir/PM Re chamber was tested for a total of 24 firings and 4.58 hr at a mixture ratio of 4.2. After only 9 firings, the annealed ED Ir coating began to blister and spall upstream of the throat. The blistering and spalling were similar to what had been experienced with unannealed, as-deposited ED Ir coatings. The HIP ED Ir/PM Re chamber was tested for a total of 91 firings and 11.45 hr at mixture ratios of 3.2 and 4.2. The HIP ED Ir coating remained adherent to the Re substrate throughout testing; there were no visible signs of coating degradation. Metallography revealed, however, thinning of the HIP Ir coating and occasional pores in the Re layer upstream of the throat. Pinholes in the Ir coating may have provided a path for oxidation of the Re substrate at these locations. The HIP ED Ir coating proved to be more effective than vacuum annealed and as-deposited ED Ir. Further densification is still required to

  9. Sister M. Madeleva Wolff, C.S.C.

    Petit, M. Loretta


    Sister M. Madeleva Wolff, C.S.C., teacher, essayist, poet, and college administrator, through her creative ability and innovative practices made possible major contributions to Catholic education in her lifetime. Without her strong personality and boundless energy, many of her dreams for an ideal college curriculum would not have come to fruition.…

  10. Crystallization and rhenium MAD phasing of the acyl-homoserinelactone synthase EsaI

    Watson, W.T.; Murphy IV, Frank V.; Gould, Ty A.; Jambeck, Per; Val, Dale L.; Cronan, Jr., John E.; Beck von Bodman, Susan; Churchill, Mair E.A. (UIUC); (Colorado); (Connecticut)


    Acyl-homoserine-L-lactones (AHLs) are diffusible chemical signals that are required for virulence of many Gram-negative bacteria. AHLs are produced by AHL synthases from two substrates, S-adenosyl-L-methionine and acyl-acyl carrier protein. The AHL synthase EsaI, which is homologous to the AHL synthases from other pathogenic bacterial species, has been crystallized in the primitive tetragonal space group P4{sub 3}, with unit-cell parameters a = b = 66.40, c = 47.33 {angstrom}. The structure was solved by multiple-wavelength anomalous diffraction with a novel use of the rhenium anomalous signal. The rhenium-containing structure has been refined to a resolution of 2.5 {angstrom} and the perrhenate ion binding sites and liganding residues have been identified.

  11. Electrotransport and diffusivity of molybdenum, rhenium, tungsten, and zirconium in beta-thorium

    Schmidt, F. A.; Beck, M. S.; Rehbein, D. K.; Conzemius, R. J.; Carlson, O. N.


    The electric mobilities, diffusivities, and effective valences were determined for molybdenum, rhenium, tungsten, and zirconium in beta-thorium. All four solutes migrated in the same direction as the electron flow. Rhenium and molybdenum were found to be very mobile, with tungsten somewhat slower. Zirconium was found to move at a rate near that of the self-diffusion of beta-thorium, viz., about 10 to the -11th sq m/s at 1500 C. The electromigration velocities showed a similar trend. A comparison was made between experimental data obtained by scanning laser mass spectrometry and theoretical transport equations for two purification experiments. Good agreement was obtained with both the concentration profile predicted by DeGroot and the purification ratio predicted by Verhoeven.

  12. Rhenium-osmium isotope constraints on the age of iron meteorites

    Horan, M.F.; Morgan, J.W.; Walker, R.J.; Grossman, J.N.


    Rhenium and osmium concentrations and the osmium isotopic compositions of iron meteorites were determined by negative thermal ionization mass spectrometry. Data for the IIA iron meteorites define an isochron with an uncertainty of approximately ??31 million years for meteorites ???4500 million years old. Although an absolute rhenium-osmium closure age for this iron group cannot be as precisely constrained because of uncertainty in the decay constant of 187Re, an age of 4460 million years ago is the minimum permitted by combined uncertainties. These age constraints imply that the parent body of the IIAB magmatic irons melted and subsequently cooled within 100 million years after the formation of the oldest portions of chondrites. Other iron meteorites plot above the IIA isochron, indicating that the planetary bodies represented by these iron groups may have cooled significantly later than the parent body of the IIA irons.

  13. Broad Detection Range Rhenium Diselenide Photodetector Enhanced by (3-Aminopropyl)Triethoxysilane and Triphenylphosphine Treatment.

    Jo, Seo-Hyeon; Park, Hyung-Youl; Kang, Dong-Ho; Shim, Jaewoo; Jeon, Jaeho; Choi, Seunghyuk; Kim, Minwoo; Park, Yongkook; Lee, Jaehyeong; Song, Young Jae; Lee, Sungjoo; Park, Jin-Hong


    The effects of triphenylphosphine and (3-aminopropyl)triethoxysilane on a rhenium diselenide (ReSe2 ) photodetector are systematically studied by comparing with conventional MoS2 devices. This study demonstrates a very high performance ReSe2 photodetector with high photoresponsivity (1.18 × 10(6) A W(-1) ), fast photoswitching speed (rising/decaying time: 58/263 ms), and broad photodetection range (possible above 1064 nm).

  14. Synthesis and Characterization of Rhenium(V) Oxo Complexes Bearing PNP-Pincer Ligands

    Korstanje, Ties J.; Lutz, Martin; Jastrzebski, Johann T. B. H.; Klein Gebbink, Bert


    The synthesis of a series of pyridine-based PNP-pincer rhenium-oxo complexes, with phenyl (1, 3), tertbutyl (2), or cyclohexyl (4) groups on the phosphorus atoms and either a ReO2X (1, 2) or a ReCl2O (3, 4) core is reported. The structures of these compounds were characterized using H-1, C-13, and P

  15. Characterization of rhenium compounds obtained by electrochemical synthesis after aging process

    Vargas-Uscategui, Alejandro, E-mail: [Departamento de Ingeniería de Minas, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile); Mosquera, Edgar [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile); López-Encarnación, Juan M. [Department of Mathematics-Physics and Department of Chemistry, University of Puerto Rico at Cayey, 205 Ave. Antonio R. Barceló, Cayey, PR 00736, USA. (Puerto Rico); Chornik, Boris [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Blanco Encalada Av. 2008, Santiago (Chile); Katiyar, Ram S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico San Juan, San Juan, PR 00931-3343 (United States); Cifuentes, Luis [Departamento de Ingeniería de Minas, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile)


    The proper identification of the molecular nature of the aged rhenium compound obtained by means of electrodeposition from an alkaline aqueous electrolyte was determined. Chemical, structural and vibrational experimental characterization of the aged Re compound showed agreement with quantum-computations, thereby allowing the unambiguous identification of the Re compound as H(ReO{sub 4})H{sub 2}O. - Graphical abstract: Rhenium oxides were electrodeposited on a copper surface and after environmental aging was formed the H(ReO{sub 4})H{sub 2}O compound. The characterization of the synthesized material was made through the comparison of experimental evidence with quantum mechanical computations carried out by means of density functional theory (DFT). - Highlights: • Aged rhenium compound obtained by means of electrodeposition was studied. • The study was made by combining experimental and DFT-computational information. • The aged electrodeposited material is consistent with the H(ReO{sub 4})H{sub 2}O compound.

  16. A Study on the Trapping Characteristics of Rhenium Oxide Using Ca(OH){sub 2}

    Lee, Tae-Kyo; Eun, Hee-Chul; Choi, Jung-Hoon; Lee, Ki-Rak; Han, Seung-Youb; Park, Hwan-Seo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The objective of this study was to obtain basic data for trapping gaseous technetium (Tc) oxide generated from the voloxidation process in spent nuclear fuel pyroprocessing. Rhenium (Re) and Ca(OH){sub 2} were used as surrogates for the technetium and a trapping material, respectively. The trapping characteristics of rhenium oxide were investigated with changing temperatures and molar ratios of calcium (Ca) over rhenium, and the thermal behaviors of the trapping products were observed. The products following after the trapping test were identified as Ca(ReO{sub 4}){sub 2} and Ca{sub 5}Re{sub 2}O{sub 12}. The conversion to Ca{sub 5}Re{sub 2}O{sub 12} was preferred with increasing temperatures, and the trapping products were completely converted into Ca5Re2O12 under conditions exceeding 800 ℃, or when maintained at 750 ℃ for 4 hr. The trapping efficiency at a molar ratio of 2.5 (Ca:Re=5:2) was significantly superior to that at the molar ratio of 2.

  17. Alleviation of bone pain in prostate cancer. Effectiveness of treatment with rhenium-186 HEDP; Linderung von Knochenschmerzen bei metastasiertem Prostatakarzinom. Nutzen der Radionuklidtherapie mit Rhenium-186-HEDP

    Klutmann, S.; Bohuslavizki, K.H. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. fuer Nuklearmedizin


    Pain caused by bone metastases from carcinoma of the prostate are treated in particular by non-steroidal anti-inflammatory drugs and opioid-containing analgesics. In case of painful multilocular metastases, the use of osteotropic radionuclides which selectively irradiate the bone metastases while sparing healthy surrounding tissue offers an alternative. Owing to their favorable physical properties, rhenium-189 and samarium-153 are preferentially used. The rate of side effects - for the most part transient thrombocytopenia - is low, and the response rate is roughly 70 to 80% of the patients treated. Pain relief may last for between 1 and 6 months, with the option of multiple treatments. The prognosis of the disease is, however, not affected. (orig.) [German] Das Skelettsystem ist nach der lymphatischen Metastasierung der zweithaeufigste Sitz von Metastasen beim Prostatakarzinom. Um die Lebensqualitaet dieser Patienten zu verbessern, steht die effektive Schmerzbekaempfung im Mittelpunkt der Therapie. Neben der Gabe von Analgetika ist hier die Applikation des osteotropen Radionuklids Rhenium-186 gut geeignet. (orig.)

  18. C.S.Lewis: The Chronicles of Narnia and imagination

    Gojkošek, Monika


    The thesis entitled C. S. Lewis: The Chronicles of Narnia and imagination primarily focuses on the term fantastic novel, its development in Slovene literature and the definition of the term itself which changed during time. Since J. J. Kenda places The Chronicles of Narnia among fantasy literature a special emphasis is also given to the latter term. The second part of the thesis deals with the stories of The Chronicles of Narnia and the circumstances of their origin. An important part of the...

  19. Elastic and electronic properties of hexagonal rhenium sub-nitrides Re{sub 3}N and Re{sub 2}N in comparison with hcp-Re and wurtzite-like rhenium mononitride ReN

    Bannikov, Vyacheslav V.; Shein, Igor R.; Ivanovskii, Alexander L. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation)


    Very recently, two hexagonal rhenium sub-nitrides Re{sub 3}N and Re{sub 2}N, which belong to a rather rare group of known metal-rich (M/N > 1) nitrides of heavy 4d, 5d metals, have been successfully synthesized, and their potential technological applications as ultra-incompressible materials have been proposed. In this work, we present a detailed ab initio study of recently synthesized rhenium sub-nitrides in comparison with hcp-Re and wurtzite-like rhenium mono-nitride ReN, with the purpose to evaluate the trends of the elastic, electronic properties, and chemical bonding in the series of these hexagonal systems as a function of the Re/N stoichiometry: Re {yields} Re{sub 3}N {yields} Re{sub 2}N {yields} ReN. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Elastic and electronic properties of hexagonal rhenium sub-nitrides Re3N and Re2N in comparison with hcp-Re and wurtzite-like rhenium mononitride ReN

    Bannikov, Vyacheslav V.; Shein, Igor R.; Ivanovskii, Alexander L.


    Very recently, two new hexagonal rhenium sub-nitrides Re3N and Re2N, which belong to a rather rare group of known metal-rich (M/N > 1) nitrides of heavy 4d,5d metals, have been successfully synthesized, and their potential technological applications as ultra-incompressible materials have been proposed. In this work we present a detailed ab initio study of novel rhenium sub-nitrides in comparison with hcp-Re and wurtzite-like rhenium mono-nitride ReN, with the purpose to evaluate the trends of the elastic, electronic properties and chemical bonding in the series of these hexagonal systems as a function of the Re/N stoichiometry: Re \\rightarrow Re3N \\rightarrow Re2N \\rightarrow ReN.

  1. Development and Testing of Tungsten-rhenium Thermocouples%钨铼热电偶开发与测试

    王彦明; 郝彦军


    近年来随着钨铼丝测温精度的不断提高,并因其廉价性,钨铼型快速热电偶将逐渐替代铂铑型快速热电偶。介绍钨铼热电偶开发与测试过程中的一些要点。%In recent years, with the continuous improvement of the tungsten-rhenium wire temperature measurement accuracy, and its cheap, fast tungsten-rhenium thermocouples will gradually replace the platinum and rhodium fast thermocouple. This article describes some of the key points in the tungsten-rhenium thermocouples development and testing process.

  2. Biodistribution of rhenium cluster complex K₄[Re6S8(CN)6] in the body of laboratory rats.

    Brylev, K A; Shestopalov, M A; Khripko, O P; Trunova, V A; Zvereva, V V; Wang, C C; Mironov, Yu V; Fedorov, V E


    We studied the biodistribution of luminescent octahedral rhenium cluster complex K4[Re6S8(CN)6], a promising agent for photodynamic therapy. It was shown that rhenium complex [Re6S8(CN)6](4-)is mainly accumulated in the liver, the central organ of metabolism, and can be excreted by the kidneys. The cluster complex was also accumulated in the spleen in significant amount, which makes it a promising agent for creation of preparations for diagnostics and treatment of lymphoproliferative disorders. The mean lethal dose of the cluster complex was 0.38 g/kg.

  3. Lattice strains in gold and rhenium under nonhydrostatic compression to 37 GPa

    Duffy, Thomas S. [Department of Geosciences, Princeton University, Princeton, New Jersey 08544 (United States); Shen, Guoyin [Consortium for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637 (United States); Heinz, Dion L. [Department of Geophysical Sciences, The University of Chicago, Chicago, Illinois 60637 (United States); Shu, Jinfu [Geophysical Laboratory and Center for High-Pressure Research, Carnegie Institution of Washington, Washington, DC 20015 (United States); Ma, Yanzhang [Geophysical Laboratory and Center for High-Pressure Research, Carnegie Institution of Washington, Washington, DC 20015 (United States); Mao, Ho-Kwang [Geophysical Laboratory and Center for High-Pressure Research, Carnegie Institution of Washington, Washington, DC 20015 (United States); Hemley, Russell J. [Geophysical Laboratory and Center for High-Pressure Research, Carnegie Institution of Washington, Washington, DC 20015 (United States); Singh, Anil K. [Materials Science Division, National Aerospace Laboratories, Bangalore 5600 17, (India)


    Using energy-dispersive x-ray diffraction techniques together with the theory describing lattice strains under nonhydrostatic compression, the behavior of a layered sample of gold and rhenium has been studied at pressures of 14-37 GPa. For gold, the uniaxial stress component t is consistent with earlier studies and can be described by t=0.06+0.015P where P is the pressure in GPa. The estimated single-crystal elastic moduli are in reasonable agreement with trends based on extrapolated low-pressure data. The degree of elastic anisotropy increases as {alpha}, the parameter which characterizes stress-strain continuity across grain boundaries, is reduced from 1.0 to 0.5. For rhenium, the apparent equation of state has been shown to be strongly influenced by nonhydrostatic compression, as evidenced by its dependence on the angle {psi} between the diffracting plane normal and the stress axis. The bulk modulus obtained by inversion of nonhydrostatic compression data can differ by nearly a factor of 2 at angles of 0 degree sign and 90 degree sign . On the other hand, by a proper choice of {psi}, d spacings corresponding to quasihydrostatic compression can be obtained from data obtained under highly nonhydrostatic conditions. The uniaxial stress in rhenium over the pressure range from 14-37 GPa can be described by t=2.5+0.09P. The large discrepancy between x-ray elastic moduli and ultrasonic data and theoretical calculations indicates that additional factors such as texturing or orientation dependence of t need to be incorporated to more fully describe the strain distribution in hexagonal-close-packed metals. (c) 1999 The American Physical Society.

  4. Highly anisotropic rhenium(IV) complexes: new examples of mononuclear single-molecule magnets.

    Martínez-Lillo, José; Mastropietro, Teresa F; Lhotel, Elsa; Paulsen, Carley; Cano, Joan; De Munno, Giovanni; Faus, Juan; Lloret, Francesc; Julve, Miguel; Nellutla, Saritha; Krzystek, J


    The rhenium(IV) complex (NBu4)2[ReBr4(ox)] (1) (ox = oxalate and NBu4(+) = tetra-n-butylammonium cation) has been prepared and its crystal structure determined by X-ray diffraction. The structure is made up of discrete [ReBr4(ox)](2-) anions and bulky NBu4(+) cations. Each [ReBr4(ox)](2-) anion is surrounded by six NBu4(+) cations, which preclude any significant intermolecular contact between the anionic entities, the shortest rhenium···rhenium distance being 9.373(1) Å. Variable temperature dc and ac magnetic susceptibility measurements and field-dependent magnetization experiments on polycrystalline samples of 1 reveal the occurrence of highly anisotropic magnetically isolated Re(IV) centers (S(Re) = 3/2), which exhibit slow relaxation of the magnetization at very low temperatures in a dc field. Ac measurements conducted on a polycrystalline sample of the complex (NBu4)2[ReCl4(ox)] (2) [compound isostructural to 1 whose structure and dc magnetic susceptibility study were previously reported in Tomkiewicz, A.; Bartczak, T. J.; Kruszyński, R.; Mroziński, J. J. Mol. Struct. 2001, 595, 225] show a similar behavior, both complexes thus constituting new examples of mononuclear single-molecule magnets. High-frequency and -field electron paramagnetic resonance on polycrystalline samples of 1 and 2 and on single crystals of 2 allowed for the determination for the first time of the negative sign and confirmed a significant magnitude and rhombicity (E/D) of the zero-field splitting tensor of the [ReCl4(ox)](2-) and [ReBr4(ox)](2-) centers, originating from a combination of spin-orbit coupling and low molecular symmetry. D and E values of 1 and 2 were estimated through magnetization measurements and theoretically calculated through complete active space and density functional theory methodologies.

  5. Exchange interactions and Tc in rhenium-doped silicon: DFT, DFT + U and Monte Carlo calculations.

    Wierzbowska, Małgorzata


    Interactions between rhenium impurities in silicon are investigated by means of the density functional theory (DFT) and the DFT + U scheme. All couplings between impurities are ferromagnetic except the Re-Re dimers which in the DFT method are nonmagnetic, due to the formation of the chemical bond supported by substantial relaxation of the geometry. The critical temperature is calculated by means of classical Monte Carlo (MC) simulations with the Heisenberg Hamiltonian. The uniform ferromagnetic phase is obtained with the DFT exchange interactions at room temperature for the impurities concentration of 7%. With the DFT + U exchange interactions, the ferromagnetic clusters form above room temperature in MC samples containing only 3% Re.

  6. Effects of pressure and temperature on the yield strength of tantalum and rhenium

    Crow, Joseph Allan

    The effects of pressure and temperature on the yield strength of tantalum and the effects of pressure on the yield strength of rhenium were investigated using ruby fluorescence. A new Raman system with a motorized stage and near diffraction limit was built to map 2-dimensionally, the pressures inside of a diamond anvil cell. The 2-dimensional data is used to create contour maps and surface plots of the pressures and calculate the pressure gradients induced in the samples. Using the Birch-Murnaghan equation of state, the final sample thickness, and the pressure gradients, the yield strength as a function of temperature and pressure are calculated.

  7. Potential Antitumor Dendrimers: Synthesis and Characterizations of Rhenium(Ⅰ) and Cis-platin Containing Dendrimers

    Zhao Xinxin; Chit-Kay Chu


    @@ 1Introduction The chemistry of dendrimers is a fast developing field and has brought about a tsunami of research activity since Vogtle reported the first preparation in 1978. These hyperbranched macromolecules have grown out of chemists' imagination and have challenged synthetic chemists with their architectural complexity and intriguity. The potentials of these macromolecules are extensive and are synthesized using both organic and inorganic cores from which different scaffoldings are built, and upon which functionalities are attached for specific applications. The synthesis and characterizations of cisplatin and rhenium(Ⅰ) containing PAMAM derivatives will be discussed.

  8. Theoretical investigations on the elastic and thermodynamic properties of rhenium phosphide

    Wei, Qun; Zhu, Xuanmin; Lin, Zhengzhe; Yao, Ronghui [Xidian Univ., Xi' an (China). School of Physics and Optoelectronic Engineering; Yan, Haiyan [Baoji Univ. of Arts and Sciences (China). Dept. of Chemistry and Chemical Engineering


    Structural, mechanical, and electronic properties of orthorhombic rhenium phosphide (Re{sub 2}P) are systematically investigated by using first principles calculations. The elastic constants and anisotropy of elastic properties are obtained. The metallic character of Re{sub 2}P is demonstrated by density of state calculations. The quasi-harmonic Debye model is applied to the study of the thermodynamic properties. The thermal expansion, heat capacities, and Grueneisen parameter on the temperature and pressure have been determined as a function of temperature and pressure in the pressure range from 0 to 100 GPa and the temperature range from 0 to 1600 K.

  9. Enantiopure Radical Cation Salt Based on Tetramethyl-Bis(ethylenedithio-Tetrathiafulvalene and Hexanuclear Rhenium Cluster

    Flavia Pop


    Full Text Available Electrocrystallization of the (S,S,S,S enantiomer of tetramethyl-bis(ethylenedithio-tetrathiafulvalene donor 1 in the presence of the dianionic hexanuclear rhenium (III cluster [Re6S6Cl8]2− affords a crystalline radical cation salt formulated as [(S-1]2·Re6S6Cl8, in which the methyl substituents of the donors adopt an unprecedented all-axial conformation. A complex set of intermolecular TTF···TTF and cluster···TTF interactions sustain an original tridimensional architecture.

  10. Synthesis, molecular structure and magnetic properties of a rhenium(IV) compound with catechol

    Cuevas, A.; Geis, L.; Pintos, V.; Chiozzone, R.; Sanchíz, J.; Hummert, M.; Schumann, H.; Kremer, C.


    A novel Re(IV) complex containing catechol as ligand has been prepared and characterized. The crystal structure of (HNEt 3)(NBu 4)[ReCl 4(cat)]·H 2cat was determined. The rhenium ion presents a distorted octahedral geometry, being bonded to a bidentate catecholate group and four chloride anions. The magnetic properties of the complex were studied, a /2 D/ (the energy gap between ±3/2 and ±1/2 Kramers doublets) value of 190(10) cm -1. This is the largest /2 D/ value reported for Re(IV) up to now.

  11. Direct radiometric dating of hydrocarbon deposits using rhenium-osmium isotopes.

    Selby, David; Creaser, Robert A


    Rhenium-osmium (Re-Os) data from migrated hydrocarbons establish the timing of petroleum emplacement for the giant oil sand deposits of Alberta, Canada, at 112 +/- 5.3 million years ago. This date does not support models that invoke oil generation and migration for these deposits in the Late Cretaceous. Most Re-Os data from a variety of deposits within the giant hydrocarbon system show similar characteristics, supporting the notion of a single source for these hydrocarbons. The Re-Os data disqualify Cretaceous rocks as the primary hydrocarbon source but suggest an origin from older source rocks. This approach should be applicable to dating oil deposits worldwide.

  12. The Microcalorimeter Arrays for a Rhenium Experiment (MARE): a next-generation calorimetric neutrino mass experiment

    Monfardini, A; Brofferio, C; Capelli, S; Capozzi, F; Cremonesi, O; Enss, C; Fiorini, E; Fleischmann, A; Foggetta, L; Gallinaro, G; Gastaldo, L; Gatti, F; Giuliani, A; Gorla, P; Kelley, R; Kilbourne, C A; Margesin, B; McCammon, D; Nones, C; Nucciotti, A; Pavan, M; Pedretti, M; Pergolesi, D; Pessina, G; Porter, F S; Prest, M; Previtali, E; Repetto, P; Ribeiro-Gomez, M; Sangiorgio, S; Sisti, M


    Neutrino oscillation experiments have proved that neutrinos are massive particles, but can't determine their absolute mass scale. Therefore the neutrino mass is still an open question in elementary particle physics. An international collaboration is growing around the project of Microcalorimeter Arrays for a Rhenium Experiment (MARE) for directly measuring the neutrino mass with a sensitivity of about 0.2eV/c2. Many groups are joining their experiences and technical expertise in a common effort towards this challenging experiment. We discuss the different scenarios and the impact of MARE as a complement of KATRIN.

  13. From N-alkylimidazole ligands at a rhenium center: ring opening or formation of NHC complexes.

    Huertos, Miguel A; Pérez, Julio; Riera, Lucía; Menéndez-Velázquez, Amador


    Cationic rhenium tricarbonyl complexes with three N-alkylimidazole ligands undergo deprotonation of the central CH group upon reaction with 1 equiv of KN(SiMe3)2. For the tris(N-methylimidazole) complex, the metal fragment shifts from N to C, leaving an NHC complex with a nonsubstituted N atom. For compounds with at least one N-mesitylimidazole ligand, the intramolecular attack of the deprotonated carbon onto the central carbon of an N-mesitylimidazole ligand results in ring opening of the latter.

  14. A first-principles model for anomalous segregation in dilute ternary tungsten-rhenium-vacancy alloys

    Wróbel, J. S.; Nguyen-Manh, D.; Kurzydłowski, K. J.; Dudarev, S. L.


    The occurrence of segregation in dilute alloys under irradiation is a highly unusual phenomenon that has recently attracted attention, stimulated by the interest in the fundamental properties of alloys as well as by their applications. The fact that solute atoms segregate in alloys that, according to equilibrium thermodynamics, should exhibit full solubility, has significant practical implications, as the formation of precipitates strongly affects physical and mechanical properties of alloys. A lattice Hamiltonian, generalizing the so-called ‘ABV’ Ising model and including collective many-body inter-atomic interactions, has been developed to treat rhenium solute atoms and vacancies in tungsten as components of a ternary alloy. The phase stability of W–Re-vacancy alloys is assessed using a combination of density functional theory (DFT) calculations and cluster expansion (CE) simulations. The accuracy of CE parametrization is evaluated against the DFT data, and the cross-validation error is found to be less than 4.2 meV/atom. The free energy of W–Re-vacancy ternary alloys is computed as a function of temperature using quasi-canonical Monte Carlo simulations, using effective two, three and four-body interactions. In the low rhenium concentration range (<5 at. % Re), solute segregation is found to occur in the form of voids decorated by Re atoms. These vacancy-rhenium clusters remain stable over a broad temperature range from 800 K to 1600 K. At lower temperatures, simulations predict the formation of Re-rich rhenium–vacancy clusters taking the form of sponge-like configurations that contain from 30 to 50 at. % Re. The anomalous vacancy-mediated segregation of Re atoms in W can be rationalized by analyzing binding energy dependence as a function of Re to vacancy ratio as well as chemical Re–W and Re-vacancy interactions and short-range order parameters. DFT calculations show that rhenium–vacancy binding energies can be as high as 1.5 eV if the

  15. C-S bond cleavage by a polyketide synthase domain.

    Ma, Ming; Lohman, Jeremy R; Liu, Tao; Shen, Ben


    Leinamycin (LNM) is a sulfur-containing antitumor antibiotic featuring an unusual 1,3-dioxo-1,2-dithiolane moiety that is spiro-fused to a thiazole-containing 18-membered lactam ring. The 1,3-dioxo-1,2-dithiolane moiety is essential for LNM's antitumor activity, by virtue of its ability to generate an episulfonium ion intermediate capable of alkylating DNA. We have previously cloned and sequenced the lnm gene cluster from Streptomyces atroolivaceus S-140. In vivo and in vitro characterizations of the LNM biosynthetic machinery have since established that: (i) the 18-membered macrolactam backbone is synthesized by LnmP, LnmQ, LnmJ, LnmI, and LnmG, (ii) the alkyl branch at C-3 of LNM is installed by LnmK, LnmL, LnmM, and LnmF, and (iii) leinamycin E1 (LNM E1), bearing a thiol moiety at C-3, is the nascent product of the LNM hybrid nonribosomal peptide synthetase (NRPS)-acyltransferase (AT)-less type I polyketide synthase (PKS). Sulfur incorporation at C-3 of LNM E1, however, has not been addressed. Here we report that: (i) the bioinformatics analysis reveals a pyridoxal phosphate (PLP)-dependent domain, we termed cysteine lyase (SH) domain (LnmJ-SH), within PKS module-8 of LnmJ; (ii) the LnmJ-SH domain catalyzes C-S bond cleavage by using l-cysteine and l-cysteine S-modified analogs as substrates through a PLP-dependent β-elimination reaction, establishing l-cysteine as the origin of sulfur at C-3 of LNM; and (iii) the LnmJ-SH domain, sharing no sequence homology with any other enzymes catalyzing C-S bond cleavage, represents a new family of PKS domains that expands the chemistry and enzymology of PKSs and might be exploited to incorporate sulfur into polyketide natural products by PKS engineering.

  16. Electrochemical synthesis, structural characterization, and decomposition of rhenium oxoethoxide, Re4O4(OEt)12. Ligand influence on the structure and bonding in the high-valent tetranuclear planar rhenium alkoxide clusters.

    Nikonova, Olesya A; Jansson, Kjell; Kessler, Vadim G; Sundberg, Margareta; Baranov, Alexei I; Shevelkov, Andrei V; Drobot, Dmitrii V; Seisenbaeva, Gulaim A


    Anodic oxidation of rhenium in ethanol in the presence of LiCl as a conductive additive results with high yield in formation of a new oxoethoxide cluster, Re(4)O(4)(OEt)(12). The structure of the planar centrosymmetric metal-oxygen core of this molecule is composed of four edge-sharing Re(V)O(6) octahedra. Eight electrons are available for the formation of metal-metal bonds indicated by five relatively short Re-Re distances within the Re 4-rhombus, a "planar butterfly" type cluster. The theoretical calculations are indicating relatively low contribution of metal-metal bonding in the stability of the core. The stability of the +V-oxidation state, unusual for rhenium alkoxides can be at least partially attributed to the size effects in the packing of ligands. The X-ray powder study indicates that treatment of Re(4)O(4)(OEt)(12). in ambient atmosphere rapidly transforms it into a mixed-valence derivative Re(4)O(6)(OEt)(10) with a structure related to the earlier investigated cluster Re(4)O(6)(O(i)Pr)(10). Thermal decomposition of the latter rhenium oxoethoxide results in reduction to rhenium metal at as low temperatures as 380 degrees C, producing aggregates of metal nanoparticles with the average size of 3 nm.

  17. Rhenium-coated glass beads for intracolonic administration attenuate TNBS-induced colitis in mice: Proof-of-Concept Study.

    Siczek, Krzysztof; Zatorski, Hubert; Pawlak, Wojciech; Fichna, Jakub


    In search for novel effective treatments in inflammatory bowel diseases, a new strategy employing glass beads coated with rhenium nanolayer has been developed and validated in the mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. Briefly, mice were randomly divided into 5 experimental groups: control (vehicle alone, Group 1); control treated with rhenium-coated glass beads (Group 2); TNBS (Group 3); TNBS treated with rhenium-coated glass beads (Group 4); and TNBS treated with uncoated glass beads (Group 5). Mice from Group 2, 4 and 5 were treated with respective beads (once daily, 5 beads / animal, i.c.) between D3-D6 post-TNBS/vehicle and evaluation of colonic damage was performed on D7, based on macroscopic scoring and clinical parameters. Severe colonic inflammation developed in post-TNBS mice (Group 3) [P glass beads (Group 4) [P glass beads had any effect in control animals (Group 2), nor uncoated glass beads influenced TNBS-induced colitis (Group 5). In conclusion, a novel and attractive strategy for the treatment of colonic inflammation has been proposed; therapy with rhenium-coated glass beads already proved effective in the mouse model of TNBS-induced colitis, now requires further characterization in clinical conditions.

  18. Effect of operational parameters and internal recycle on rhenium solvent extraction from leach liquors using a mixer-settler

    Mostafa Hosseinzadeh


    Full Text Available The extraction of rhenium from molybdenite roasting dust leach solution was performed using a mixer-settler extractor by tributyl phosphate (TBP diluted in kerosene as the extractant. In the single-stage extraction experiments, effect of the aqueous to organic phase ratios, Qa/Qo, and the number of extraction stages, N, on the rhenium extraction was studied. It was found that using the phase ratio of 1:1 in a two-stage extraction, 87.5% depletion of rhenium was obtained. The comparison of experimental results with the continuous co-current extraction showed a good agreement. The effect of internal recycle of organic phase was investigated in the phase ratio of 1:1 by changing the flow rate ratio of recycle-to-fresh organic phase, Qro/Qfo. The optimum performance was achieved in the phase ratio, Qro/Qfo, equal to 3:7. It was found that improvement in the performance of the mixer-settler for the rhenium-TBP system can be obtained in the phase ratio of 1:1when Qro/Qfo = 3:7.

  19. Thermal reaction of SiC films with tungsten and tungsten-rhenium alloys

    Roger, J.; Le Petitcorps, Y. [Univ Bordeaux 1, Lab Composites Thermostruct, CNRS-SAFRAN-CEA-UB1, UMR 5801, F-33600 Pessac, (France); Roger, J.; Audubert, F. [CEA Cadarache, DEN/DEC/SPUA/LTEC, F-13108 St Paul Les Durance, (France)


    Solid-state reactions between SiC films and W-xRe (x = 0, 5 and 25 at%) substrates on thermal annealing between 1673 K and 1873 K for various durations have been investigated. SiC coatings were deposited on metallic wires by hot filament chemical vapour deposition (HFCVD) from a gas mixture of tetramethyl-silane (TMS) and hydrogen at 1373 K under normal pressure. The interface zones were characterized using scanning electron and optical microscopies, X-ray diffraction and electron microprobe microanalysis. All analyses reveal that SiC reacts with substrates. Various metal silicides and carbides were formed in layered reaction and the presence of these phases was confirmed by electron probe microanalysis. The effects of rhenium on the reactivity were established by the determination of growth kinetics deducted from the thicknesses of reaction zones as a function of annealing time. It has been found that an increase in the diffusion kinetics and activation energy with the quantity of rhenium in the tungsten wire. (authors)

  20. Tungsten alloyed with rhenium as an advanced material for heat-resistant silicon ICs interconnects

    Belov, A. N.; Chaplygin, Yu. A.; Golishnikov, A. A.; Kostyukov, D. A.; Putrya, M. G.; Safonov, S. O.; Shevyakov, V. I.


    This paper presents the results of comparative analysis of the electrical and mechanical characteristics of the tungsten and tungsten alloyed with rhenium films deposited on silicon, from the point of view of their use as interconnects in silicon ICs. W and W (Re-5%) alloyed with rhenium films were made by magnetron deposition. Sheet resistivity for W and W (Re- 5%) was 13 and 27 μOhm·cm respectively. Elemental composition the formed films was examined by Auger spectroscopy. To investigate the electromigration resistance of the conductors a methodology based on the accelerated electromigration testing at constant temperature was used. A comparative analysis of the mechanical stresses carried out in the W and W(Re - 5%) films. For this purpose was applied non-destructive method for optical laser scanning. At the same time, these films explored their ability of adhesion to silicon and silicon oxide. It is shown that the pull force of the W(Re - 5%) films was 1500 G/mm2, of the W films 700 G/mm2

  1. Photocatalytic H2 production from water with rhenium and cobalt complexes.

    Probst, Benjamin; Guttentag, Miguel; Rodenberg, Alexander; Hamm, Peter; Alberto, Roger


    Photocatalytic hydrogen production in pure water for three component systems using a series of rhenium-based photosensitizers (PS) and cobalt-based water reduction catalysts (WRC), with triethanolamine (TEOA) as an irreversible electron donor, is described. Besides the feasibility of this reaction in water, key findings are reductive quenching of the excited state of the PS by TEOA (k(q) = 5-8 × 10(7) M(-1) s(-1); Φ(cage) = 0.75) and subsequent transfer of an electron to the WRC (k(Co(III)) = 1.1 × 10(9) M(-1) s(-1)). Turnover numbers in rhenium (TON(Re), H/Re) above 500 were obtained, whereas TON(Co) (H(2)/Co) did not exceed 17. It is shown that the cobalt-based WRC limits long-term performance. Long-term performance critically depends on pH and the type of WRC used but is unaffected by the type of PS or the concentration of WRC. A quantum yield of 30% was obtained (H/photon).

  2. Characterization of rhenium oxide films and their application to liquid crystal cells

    Cazzanelli, E.; Castriota, M.; Marino, S.; Scaramuzza, N.; Purans, J.; Kuzmin, A.; Kalendarev, R.; Mariotto, G.; Das, G.


    Rhenium trioxide exhibits high electronic conductivity, while its open cubic crystal structure allows an appreciable hydrogen intercalation, generating disordered solid phases, with protonic conductivity. Rhenium oxide thin films have been obtained by thermal evaporation of ReO3 powders on different substrates, maintained at different temperatures, and also by reactive magnetron sputtering of a Re metallic target. A comparative investigation has been carried out on these films, by using micro-Raman spectroscopy and x-ray diffraction. Two basic types of solid phases appear to grow in the films: a red metallic HxReO3 compound, with distorted perovskite structures, like in the bulk material, and ordered HReO4 crystals based on tetrahedral perrhenate ions. Because of its conduction properties, the electrical and electro-optical behaviors of ReO3 films deposited on standard indium tin oxide/glass substrate have been tested inside asymmetric nematic liquid crystal cells, showing an appreciable capability of rectification of their electro-optical response, in similar way to tungsten trioxide.

  3. On the stability of rhenium up to 1 TPa pressure against transition to the bcc structure

    A K Verma; P Ravindran; R S Rao; B K Godwal; R Jeanloz


    We have carried out electronic structure total energy calculations on rhenium in the hexagonal close packed (hcp) and body centred cubic (bcc) phases, by the full potential linear muffin–tin orbital method, in order to verify the stability of the ambient pressure hcp phase against transition to the bcc structure at high pressures. As per our results, no hcp to bcc structural transition can occur up to 1 TPa pressures. Moreover, our Bain path calculations show that face centred cubic and body centred tetragonal structures are also not energetically preferred over hcp in this pressure range. The axial ratio (/) of Re changes by less than 0.33% in the pressure range studied.

  4. Osmium isotopes in Ivory Coast tektites: Confirmation of a meteoritic component and rhenium depletion

    Koeberl, Christian; Shirey, Steven B.


    The sensitive negative thermal ionization mass spectrometry method was used for the measurement of concentrations and isotopic ratios of osmium and rhenium in four Ivory Coast tektites. These tektites have crustal major and trace element composition, as well as large negative epsilonNd(-20) and positive epsilonSr(+260 to +300) which are characteristic for old continental crust. Os concentrations ranging from 0.09 to 0.30 ppb were found, clearly much higher than average crustal values, Os-187/Os-186 ratios of about 1.2-1.7, and low Re-187/Os-186 ratios. These results show unambiguously the existence of a meteoritic component (on the order of 0.06%) in the Ivory Coast tektites. Low Re abundances are the result of fractionation of Re during the impact.

  5. Diffusion of Iodine and Rhenium in Category 3 Waste Encasement Concrete and Soil Fill Material

    Wellman, Dawn M.; Mattigod, Shas V.; Whyatt, Greg A.; Powers, Laura; Parker, Kent E.; Wood, Marcus I.


    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e. sorption or precipitation). This understanding will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. A set of diffusion experiments using carbonated and non-carbonated concrete-soil half cells was conducted under unsaturated conditions (4% and 7% by wt moisture content). Spiked concrete half-cell specimens were prepared with and without colloidal metallic iron addition and were carbonated using supercritical carbon dioxide. Spikes of I and Re were added to achieve measurable diffusion profile in the soil part of the half-cell. In addition, properties of concrete materials likely to influence radionuclide migration such as carbonation were evaluated in an effort to correlate these properties with the release of iodine and rhenium.

  6. Pressure induced enhancement of the magnetic ordering temperature in rhenium(IV) monomers

    Woodall, Christopher H.; Craig, Gavin A.; Prescimone, Alessandro; Misek, Martin; Cano, Joan; Faus, Juan; Probert, Michael R.; Parsons, Simon; Moggach, Stephen; Martínez-Lillo, José; Murrie, Mark; Kamenev, Konstantin V.; Brechin, Euan K.


    Materials that demonstrate long-range magnetic order are synonymous with information storage and the electronics industry, with the phenomenon commonly associated with metals, metal alloys or metal oxides and sulfides. A lesser known family of magnetically ordered complexes are the monometallic compounds of highly anisotropic d-block transition metals; the `transformation' from isolated zero-dimensional molecule to ordered, spin-canted, three-dimensional lattice being the result of through-space interactions arising from the combination of large magnetic anisotropy and spin-delocalization from metal to ligand which induces important intermolecular contacts. Here we report the effect of pressure on two such mononuclear rhenium(IV) compounds that exhibit long-range magnetic order under ambient conditions via a spin canting mechanism, with Tc controlled by the strength of the intermolecular interactions. As these are determined by intermolecular distance, `squeezing' the molecules closer together generates remarkable enhancements in ordering temperatures, with a linear dependence of Tc with pressure.

  7. Formation, characterization and computational studies of mono- and dinuclear rhenium(I) chromone compounds

    Ebinumoliseh, Ifeoma; Booysen, Irvin Noel; Akerman, Matthew Piers; Xulu, Bheki


    Herein, we report the formation and characterization of a novel dinuclear rhenium(I) compound, fac-(Re(CO)3Br)2(μ-chret) (1) [chret = N, N'-bis(2-amino-3-imino)methylenechromone-1,2-ethane] and a mononuclear metal complex, fac-[Re(CO)3(bzch)Br] (2) [bzch = 2-benzimidazole-4H-chromen-4-one]. The metal complexes were characterized by 1H NMR-, IR-, UV-Vis, melting point and conductivity measurements. The solid-state structures for 1 and 2 were confirmed via single crystal X-ray analysis. X-ray studies of 2 revealed the transformation of the chb diimine into the bzch chelator (in 2). The simulated IR spectra for the respective metal complexes provided insight in the interpretation of their corresponding experimental spectra.

  8. Lattice vibration frequencies in Raman spectra of manganese and rhenium decacarbonyls

    Volkov, V.E.; Danilov, I.Yu.; Zhidkov, L.L.; Kovalev, Yu.G.; Ioganson, A.A. (AN SSSR, Krasnoyarsk. Inst. Khimii i Khimicheskoj Tekhnologii)


    Raman spectra (RS) in the 170-10 cm/sup -1/ region of Mn/sub 2/(CO)/sub 10/, Re/sub 2/(CO)/sub 10/ polycrystal samples and their mixed crystals with different component percentage were obtained in the 296-123 K range. Investigations at low temperatures enabled to obtain most complete spectra in the given region. The spectra were separated to intramolecular and lattice ones on the basis of both comparing the spectra of pure components with those of mixed crystals, and studying the temperature behaviour of frequencies in the spectra. It was established that frequencies, placed below 60 cm/sup -1/ as well as in the region of 130-150 cm/sup -1/ in the spectra of manganese- and rhenium decacarbonyls are determined by the lattice vibrations of molecules in crystals.

  9. Effect of rhenium doping on various physical properties of single crystals of MoSe2

    MihirM. Vora; Aditya M. Vora


    Effect of rhenium doping is examined in single crystals of MoSe2 viz.MoRe0.005Se1.995,MoRe0.001Se1.999 and Mo0.995Re0.005Se2,which is grown by using the direct vapor transport (DVT) technique.The grown crystals are structurally characterized by X-ray diffraction,by determining their lattice parameters a and c,and X-ray density.Also,the Hall effect and thermoelectric power (TEP) measurements show that the single crystals exhibit a p-type semiconducting nature.The direct and indirect band gap measurements are also undertaken on these semiconducting materials.

  10. Rhenium-osmium concentration and isotope systematics in group IIAB iron meteorites

    Morgan, J.W.; Horan, M.F.; Walker, R.J.; Grossman, J.N.


    Rhenium and osmium abundances, and osmium isotopic compositions were measured by negative thermal ionization mass spectrometry in thirty samples, including replicates, of five IIA and eight IIB iron meteorites. Log plots of Os vs. Re abundances for IIA and IIB irons describe straight lines that approximately converge on Lombard, which has the lowest Re and Os abundances and highest 187Re/188Os measured in a IIA iron to date. The linear IIA trend may be exactly reproduced by fractional crystallization, but is not well fitted using variable partition coefficients. The IIB iron trend, however, cannot be entirely explained by simple fractional crystallization. One explanation is that small amounts of Re and Os were added to the asteroid core during the final stages of crystallization. Another possibility is that diffusional enrichment of Os may have occurred in samples most depleted in Re and Os. -from Authors

  11. Click-to-Chelate: Development of Technetium and Rhenium-Tricarbonyl Labeled Radiopharmaceuticals

    Thomas L. Mindt


    Full Text Available The Click-to-Chelate approach is a highly efficient strategy for the radiolabeling of molecules of medicinal interest with technetium and rhenium-tricarbonyl cores. Reaction of azide-functionalized molecules with alkyne prochelators by the Cu(I-catalyzed azide-alkyne cycloaddition (CuAAC; click reaction enables the simultaneous synthesis and conjugation of tridentate chelating systems for the stable complexation of the radiometals. In many cases, the functionalization of (biomolecules with the ligand system and radiolabeling can be achieved by convenient one-pot procedures. Since its first report in 2006, Click-to-Chelate has been applied to the development of numerous novel radiotracers with promising potential for translation into the clinic. This review summarizes the use of the Click-to-Chelate approach in radiopharmaceutical sciences and provides a perspective for future applications.

  12. Rhenium-188: Availability from the W-188/Re-188 Generator and Status of Current Applications

    Pillai, M R A [Bhabha Atomic Research Centre, Mumbai, India; Dash, A [Bhabha Atomic Research Centre, Mumbai, India; Knapp Jr, Russ F [ORNL


    Rhenium-188 is one of the most readily available generator derived and useful radionuclides for therapy emitting - particles (2.12 MeV, 71.1% and 1.965 MeV, 25.6%) and imageable gammas (155 KeV, 15.1%). The 188W/188Re generator is an ideal source for the long term (4-6 months) continuous availability of no carrier added (nca) 188Re suitable for the preparation of radiopharmaceuticals for radionuclide therapy. The challenges associated with the double neutron capture route of production of the parent 188W radionuclide have been a major impediment in the progress of application of 188Re. Tungsten-188 of adequate specific activity can be prepared only in 2-3 of the high flux reactors operating in the World. Several useful technologies have been developed for the preparation of clinical grade 188W/188Re generator. Since the specific activity of 188W used in the generator is relatively low (<5 Ci/g), the eluted 188ReO4- can have low radioactive concentration often insufficient for radiopharmaceutical preparation. However, several efficient post elution concentration techniques have been developed that yield clinically useful 188ReO4-. Rhenium-188 has been used for the preparation of therapeutic radiopharmaceuticals for the management of diseases such as bone metastasis, rheumatoid arthritis and primary cancers. Several early phase clinical studies using radiopharmaceuticals based on 188Re-labeled phosphonates, antibodies, peptides, lipiodol and particulates have been reported. This article reviews the availability, and use of188Re including a discussion of why broader use of 188Re has not progressed as ecpected as a popular radionuclide for therapy.

  13. Improvement of MCrAlY coatings by addition of rhenium

    Czech, N. (Siemens AG, Power Generation Group (KWU), Materials Technology, DW-45466 Muelheim a.d. Ruhr (Germany)); Schmitz, F. (Siemens AG, Power Generation Group (KWU), Materials Technology, DW-45466 Muelheim a.d. Ruhr (Germany)); Stamm, W. (Siemens AG, Power Generation Group (KWU), Materials Technology, DW-45466 Muelheim a.d. Ruhr (Germany))


    In order to improve the efficiency and power output of gas turbines, turbine inlet temperatures are being rapidly increased. Since high strength blade materials and sophisticated processes such as single-crystal solidification are nowadays available also for large parts, it is possible to increase metal surface temperatures to save cooling air. The increase in surface temperature causes a more severe oxidation attack on the blade coating, which is usually of the MCrAlY type in stationary gas turbines. Additionally, coating degradation by interdiffusion with the substrate and by thermal mechanical stress is increased. Considerable research has been carried out to improve the high temperature properties of MCrAlY (with M[identical to]Co, Ni or combinations thereof) coatings by additions of minor alloying elements such as Si, Hf, Ta, Zr, etc. However, up to this time no work has been published on the properties of MCrAlY coatings with rhenium additions for stationary gas turbines. In this paper we report on the properties of MCrAlY coatings containing 1.5-10wt.% Re. The coatings were applied to INCO 738 LC material by low pressure plasma spraying. Static and cyclic oxidation tests were carried out for up to 5000h and 1500 cycles at 950 and 1000 C. Thermal fatigue tests under near-service stresses for up to 3000 cycles were performed. The microstructural stability and the interdiffusion behaviour were studied after long-time exposure. Rhenium additions can considerably improve the oxidation resistance of ''classical'' MCrAlY systems. Even more important, however, is the improvement in thermal cycle fatigue as properties as reflected by the number of cycles until crack initiation. Thus several of these coatings can be recommended for high temperature-high thermal load applications. ((orig.))

  14. Identification of rhenium donors and sulfur vacancy acceptors in layered MoS2 bulk samples

    Brandão, F. D.; Ribeiro, G. M.; Vaz, P. H.; González, J. C.; Krambrock, K.


    MoS2 monolayers, a two-dimensional (2D) direct semiconductor material with an energy gap of 1.9 eV, offer many opportunities to be explored in different electronic devices. Defects often play dominant roles in the electronic and optical properties of semiconductor devices. However, little experimental information about intrinsic and extrinsic defects or impurities is available for this 2D system, and even for macroscopic 3D samples for which MoS2 shows an indirect bandgap of 1.3 eV. In this work, we evaluate the nature of impurities with unpaired spins using electron paramagnetic resonance (EPR) in different geological macroscopic samples. Regarding the fact that monolayers are mostly obtained from natural crystals, we expect that the majority of impurities found in macroscopic samples are also randomly present in MoS2 monolayers. By EPR at low temperatures, rhenium donors and sulfur vacancy acceptors are identified as the main impurities in bulk MoS2 with a corresponding donor concentration of about 108-12 defects/cm2 for MoS2 monolayer. Electrical transport experiments as a function of temperature are in good agreement with the EPR results, revealing a shallow donor state with an ionization energy of 89 meV and a concentration of 7 × 1015 cm-3, which we attribute to rhenium, as well as a second deeper donor state with ionization energy of 241 meV with high concentration of 2 × 1019 cm-3 and net acceptor concentration of 5 × 1018 cm-3 related to sulfur vacancies.

  15. Rhenium Alloys as Ductile Substrates for Diamond Thin-Film Electrodes.

    Halpern, Jeffrey M; Martin, Heidi B


    Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film, polycrystalline boron-doped diamond electrodes. Traditional, carbide-forming metal substrates adhere strongly to diamond but lose their ductility during exposure to the high-temperature (1000°C) diamond, chemical vapor deposition environment. Boron-doped semi-metallic diamond was selectively deposited for up to 20 hours on one end of Mo/Re (47.5/52.5 wt.%) and W/Re (75/25 wt.%) alloy wires. Conformal diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases, the morphology and Raman spectra were consistent with well-faceted, microcrystalline diamond with minimal sp(2) carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition, the films showed consistently well-defined, dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test, bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° bend, and the tungsten fractured after a 21° bend. Brittle, transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture of the Mo/Re after the prior bend test showed a dimple fracture with a visible ductile core. Overall, the Mo/Re and W/Re alloys were suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth, and thus may be an attractive metal substrate for more ductile, thin-film diamond electrodes.

  16. Synthesis, characterization, photophysical, and computational studies of rhenium(I) tricarbonyl complexes containing the derivatives of bipyrazine.

    Kirgan, Robert; Simpson, Megan; Moore, Curtis; Day, Jeff; Bui, Loan; Tanner, Clayton; Rillema, D Paul


    The chloro and pyridinate derivatives of rhenium(I) tricarbonyl complexes containing the diimine ligands 2,2'-bipyrazine (bpz) and 5,5'-dimethyl-2,2'-bipyrazine (Me2bpz) are reported. Absorption maxima occur in the visible and ultraviolet regions of the spectrum; emission is structureless at room temperature and at 77 K; the infrared spectrum consists of three carbonyl stretches; electrochemically, a reversible reduction, an irreversible reduction, and an irreversible oxidation take place. Some ring protons are shielded and others deshielded in the presence of the methyl substituents attached to the bpz ring. DFT and TDDFT calculations provide insight into interpreting electronic and vibrational properties of the complexes. When compared to similar rhenium(I) tricarbonyl complexes of 2,2'-bipyridine (bpy) and 2,2'-bipyrimidine (bpm), the Me2bpz complexes are comparable to bpm derivatives and their properties are intermediate between those of bpy and bpz complexes.

  17. C-S-H凝胶对Pb(Ⅱ)的吸附固化作用%Adsorption and Solidification of Pb(Ⅱ) by C-S-H Gel

    王昕; 刘晶; 汪澜; 考宏涛


    In order to investigate the adsorption and solidification of Pb(II) , pure C-S-H gel and Pb-doped C-S-H gel were synthesized using analytical reagent grade Ca(NO3)2·4H2O、Na2SiO3·9H2O and Pb ( NO3) 2 as raw materials by the solution reaction. The results showed the C-S-H gel had good adsorption ability while soluble lead salts increased from 2% to 6% . The X-ray diffraction patterns of Pb-doped C-S-H gel changed obviously,both in peak shift and the emergence of Ca(OH)2 diffraction peaks. Infrared tests showed that Si linkage models had been changed in the way that Q2 stretching vibration shifted to lower wavenumber and Q stretching vibration peak absorption intensity increased, specially for silicon-oxide tetrahedron structure existing in Pb-doped C-S-H gel.%以分析纯Ca(NO3)2·4H2O、Na2SiO3·9H2O、Pb(NO3)2为原料,通过溶液反应法,制备纯净的C-S-H凝胶和掺杂Pb的C-S-H凝胶,研究了C-S-H凝胶在形成过程中对Pb的吸附固化作用及掺杂Pb后C-S-H凝胶的结构变化.结果表明,可溶铅盐由2%增至6%时,C-S-H凝胶对Pb均有良好的吸附固化作用,俘获Pb总量增大.XRD图谱发现掺杂Pb的C-S-H凝胶,其主峰位置发生偏移,出现明显的Ca(OH)2衍射峰.红外测试表明含Pb C-S-H凝胶硅氧四面体的链接方式发生变化,Q2伸缩振动峰向低波数方向偏移,Q1伸缩振动峰吸收强度增加.

  18. Substituted ethan phosphonic acid esters as reagents for the separation of molybdenum from rhenium by solvent extraction.

    Jordanov, N; Mareva, S; Borisov, G; Jordanov, B


    New esters of the ethan phosphonic acids have been synthesized and their extraction properties studied with respect to Mo(VI), Re(VII), Fe(III),Au(III),Tl(III) and Sb(V). A possibility is shown for the analytical separation of molybdenum from rhenium (beta = 700). The state of these new extraction agents in carbon tetrachloride solution, and the mechanism of the extraction processes, have been investigated by means of infrared spectra.

  19. Biological dosimetry after radiosynoviorthesis with rhenium-186 sulphide and erbium-169 citrate; Strahlenbiologische Effekte nach Radiosynoviorthese mit Rhenium-186-Sulfid und Erbium-169-Citrat

    Schnurbus-Duhs, Annika Jeannine


    Aim. The aim of the present studies was to investigate the biological radiation effect of radiosynoviorthesis (RSO) with Re-186 and Er-169 in order to evaluate the safety of this procedure. Methods. RSO with rhenium-186 sulfide colloid (10 patients) or erbium-169 citrate colloid (13 patients) was carried out in a total of 23 patients. Afterwards, the treated joint was immobilised for three days using splints. From all patients, blood was drawn immediately before and 17 to 19 days (Re-186) or 45 to 50 days (Er-169) after RSO. To evaluate the radiation dose, the yield of dicentric chromosomes in lymphocytes was determined exclusively in metaphases of the first cell cycle in vitro. At least 1000 cells per patient have been analysed before and after RSO which is sufficient to find potential radiation effects after long-term exposure to low energy radiation such as to expect after RSO. In addition, for Re-186 the activity leakage from the treated joint was measured by whole-body scintigraphy. Results. In a total of 47017 cells analysed from 46 blood samples, 40 and 88 before and 59 and 105 dicentrics after RSO with Re-186 and Er-169 were found. This showed no statistically significant increase in the number of dicentric chromosomes. The measured average activity leakage of less than 5 % (less than 3 MBq) was considered to be low. Conclusion. The results of chromosome analysis and activity measurement after RSO prove that this procedure is associated with a low effective dose in treated patients and thus can be considered a safe treatment.

  20. Influence of the acid and basic properties of rhenium oxide supported on alumina catalyst on the catalytic performance in olefin metathesis; Influence des proprietes acido-basiques de l`oxyde de rhenium supporte sur les performances catalytiques en metathese des olefines

    Nahama, F.


    The aim of this work is to study the influence of the acid-basic properties of rhenium oxide supported on alumina catalyst on the catalytic performance in olefin metathesis. The literature data indicate that the environment of the active site does possess acid properties. However, the nature of the acid sites is still matter of debate. Concerning the Re O{sub x} - Al{sub 2}O{sub 3} interactions, we have shown that perrhenate ions are electrostatically absorbed on alumina. The uptake of rhenium is favoured at acidic pH (below 4), and the absorbed rhenium is in equilibrium with rhenium in solution. The results of rhenium extraction by water strongly suggest that the surface compounds of the calcined Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3} materials is aluminium perrhenate. Characterization of surface acidity of the catalyst by infrared spectroscopy reveals that the initiation of the metathesis reaction is governed essentially by Lewis acidity. This strongly supports the role of Lewis acidity, which is exalted by the increase of the rhenium content and the calcination temperature. Finally, we point out by ammonia adsorption-thermodesorption a band at 1320 cm{sup -1} characteristic of the Lewis acidity of aluminium perrhenate. This result is a second indication of the presence of aluminium perrhenate on the Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3} catalyst surface. (author)

  1. Creep deformation behaviour of Rhenium free Ni-based single crystal superalloys LSC-15

    Tsuno Nobuyasu


    Full Text Available In this paper, creep deformation behavior of Ni-based single crystal superalloys LSC-15 were studied. LSC-15 does not include Rhenium and has been developed by IHI Corporation Japan. Creep tests were performed at 1000 and 1050 ∘C under several stress levels. The creep deformation behaviour was different between test temperatures at 1000 ∘C and 1050 ∘C. Moreover, the relationship between the minimum creep rate and stress was different at the various temperatures. The stress exponent values at 1000 ∘C and 1050 ∘C, were n = 6 and 12 respectively. This difference was due to differences in the formation of dislocation network. At 1000 ∘C, when the minimum creep rate, the dislocation network formed completely independent of stress level. On the other hand, at 1050 ∘C, the dislocation network had not developed fully at the minimum creep rate and the formation of dislocation network depended on the stress level. Therefore, stress dependency at 1050 ∘C is higher than that at 1000 ∘C.

  2. Strongly phosphorescent neutral rhenium(i) isocyanoborato complexes: synthesis, characterization, and photophysical, electrochemical, and computational studies.

    Chu, Wing-Kin; Wei, Xi-Guang; Yiu, Shek-Man; Ko, Chi-Chiu; Lau, Kai-Chung


    A new series of neutral isocyanoborato rhenium(I) diimine complexes [Re(CO)3 (N^N)(CNBR3 )], where N^N=bpy, 4,4'-Me2 bpy, phen, 4,7-Me2 phen, 2,9-Me2 phen, 3,4,7,8-Me4 phen; R=C6 F5 , C6 H5 , Cl, 4-ClC6 H4 , 3,5-(CF3 )2 C6 H3 , with various isocyanoborate and diimine ligands of diverse electronic and steric nature have been synthesized and characterized. The X-ray crystal structures of six complexes have also been determined. These complexes displayed intense bluish green to yellow phosphorescence at room temperature in dichloromethane solution. The photophysical and electrochemical properties of these complexes had been investigated. To elucidate the electronic structures and transitions of these complexes, DFT and TD-DFT calculations have been performed, which revealed that the lowest-energy electronic transition associated with these complexes originates from a mixture of MLCT [dπ(Re)→π*(N^N)] and LLCT [π(CNBR3 )→π*(N^N)] transitions.

  3. Safety and Efficacy of 188-Rhenium-Labeled Antibody to Melanin in Patients with Metastatic Melanoma

    M. Klein


    Full Text Available There is a need for effective “broad spectrum” therapies for metastatic melanoma which would be suitable for all patients. The objectives of Phase Ia/Ib studies were to evaluate the safety, pharmacokinetics, dosimetry, and antitumor activity of 188Re-6D2, a 188-Rhenium-labeled antibody to melanin. Stage IIIC/IV metastatic melanoma (MM patients who failed standard therapies were enrolled in both studies. In Phase Ia, 10 mCi 188Re-6D2 were given while unlabeled antibody preload was escalated. In Phase Ib, the dose of 188Re-6D2 was escalated to 54 mCi. SPECT/CT revealed 188Re-6D2 uptake in melanoma metastases. The mean effective half-life of 188Re-6D2 was 12.4 h. Transient HAMA was observed in 9 patients. Six patients met the RECIST criteria for stable disease at 6 weeks. Two patients had durable disease stabilization for 14 weeks and one for 22 weeks. Median overall survival was 13 months with no dose-limiting toxicities. The data demonstrate that 188Re-6D2 was well tolerated, localized in melanoma metastases, and had antitumor activity, thus warranting its further investigation in patients with metastatic melanoma.

  4. Detection of a meteoritic component in Ivory Coast tektites with rhenium-osmium isotopes

    Koeberl, Christian; Shirey, Steven B.


    Measurement of rhenium (Re) and osmium (Os) concentrations and Os isotopic compositions in Ivory Coast tektites (natural glasses with upper crustal compositions that are ejected great distances during meteorite impact) and rocks from the inferred source crater, Lake Bosumtwi, Ghana, show that these tektites incorporate about 0.6 percent of a meteoritic component. Analysis of elemental abundances of noble metals alone gives equivocal results in the detection of meteoritic components because the target rocks already have relatively large amounts of noble metals. The Re-Os system is ideally suited for the study of meteorite impacts on old continental crust for three reasons. The isotopic compositions of the target rocks and the meteoritic impactor are significantly different. Closed-system mixing of target rocks and meteorites is linear on Re-Os isochron diagrams, which thus permits identification of the loss of Re or Os. Osmium isotopic compositions are not likely to be altered during meteorite impact even if Re and Os are lost.

  5. Detection of a meteoritic component in ivory coast tektites with rhenium-osmium isotopes.

    Koeberl, C; Shirey, S B


    Measurement of rhenium (Re) and osmium (Os) concentrations and Os isotopic compositions in Ivory Coast tektites (natural glasses with upper crustal compositions that are ejected great distances during meteorite impact) and rocks from the inferred source crater, Lake Bosumtwi, Ghana, show that these tektites incorporate about 0.6 percent of a meteoritic component. Analysis of elemental abundances of noble metals alone gives equivocal results in the detection of meteoritic components because the target rocks already have relatively large amounts of noble metals. The Re-Os system is ideally suited for the study of meteorite impacts on old continental crust for three reasons. (i) The isotopic compositions of the target rocks and the meteoritic impactor are significantly different. (ii) Closed-system mixing of target rocks and meteorites is linear on Re-Os isochron diagrams, which thus permits identification of the loss of Re or Os. (iii) Osmium isotopic compositions are not likely to be altered during meteorite impact even if Re and Os are lost.

  6. Histologic study of effects of radiation synovectomy with Rhenium-188 microsphere

    Wang, S.-J. E-mail:; Lin, W.-Y; Chen, M.-N.; Chen, J.-T.; Ho, W.-L.; Hsieh, B.-T.; Huang, H.; Shen, L.-H.; Ting, G.; Knapp, F. F


    Rhenium-188 microsphere is a relatively new radiation synovectomy agent developed for the treatment of rheumatoid arthritis. It has been shown that the levels of unwanted extra-articular radiation are negligible with this agent. A histologic study was conducted to assess the effect of radiation synovectomy on synovium and articular cartilage after intra-articular injection of various doses of Re-188 microspheres into the knee joints of rabbits. Intra-articular injection of Re-188 microspheres into rabbit knee joints resulted in mild reactive inflammation and thrombotic occlusion of vessels which subsided rapidly. Sclerosis of subsynovium could be seen 12 weeks after injection. No evidence of damage to articular cartilage was noted. There was no significant difference in the articular pattern after injection of 0.3 or 0.6 mCi Re-188 microspheres. This study suggests that a treatment dose of Re-188 microspheres causes transient inflammation of synovium without any detectable damage to the articular cartilage of knee joint.

  7. {sup 188}Rhenium-HEDP in the Treatment of Pain in Bone Metastases

    Gaudiano, J.; Savio, E.; Robles, A.; Muniz, S.; Leon, A.; Verdera, S.; Martinez, G.; Hermida, J.C.; Knapp, F.F., Jr.


    Systemic use of radiopharmaceuticals is a recognized alternative method for the treatment of pain in patients with multiple bone metastasis. A new option, {sup 188}Re-HEDP is proposed, using generator-obtained {sup 188}Rhenium ({beta} energy = 2.1 MeV, {gamma} energy = 155 keV, half-life = 16.9 hours). After establishing parameters of biodistribution, dosimetry and image acquisition in mice, rats and rabbits, Phase I and II studies were conducted on 12 patients with multiple metastasis from carcinomas, with pain surpassing other analgesic options. More than 50% pain relief was found in 91% of the patients, with total relief during a variable period in 41% of them allowing opiate and other analgesic drugs to be decreased or withdrawn, and showing a lower bone marrow contribution to total absorbed dose than that reported for other similar radiopharmaceuticals. Further study of this option is recommended in order to determine higher dose protocols without toxic bone marrow reaction possibilities.

  8. Pyrazolato metal complexes: synthesis, characterization and X-ray crystal structures of rhenium(I) derivaties

    Ardizzoia, G.A; LaMonica, G.; Maspero, A. [Milan Univ. (Italy). Dipt. di Chimica Inorganica, Metallorganica e Analitica; Moret, M.; Masciocchi, N. [Milan Univ. (Italy). Dipt. di Chimica Strutturale e Stereochimica Inorganica


    The mononuclear complexes [Re(CO){sub 3}(Hpz){sub 2}Br] (1) and [Re(CO){sub 3}(Hdmpz){sub 2}Br] (2) were obtained by treating [Re(CO){sub 5}Br] with pyrazole (Hpz) or 3,5-dimethylpyrazole (Hdmpz). Complex 1 reacted with triethylamine affording a mixture of the ionic dinuclear derivative (Et{sub 3}NH)[Re{sub 2}(CO){sub 6}(pz){sub 2}Br] (3) and of the mononuclear species [Re(CO){sub 3}(Hpz){sub 2}(pz)] (4). Complex 4 was obtained in a pure form by carrying out the reaction in the presence of excess free pyrazole. Treatment of 4 with pyridine afforded the [Re(CO){sub 3}(py)(Hpz)(pz)] species (6). The analogues of 4 and 6 with Hdmpz, i.e. [Re(CO){sub 3}(Hdmpz){sub 2}(dmpz)] (7) and [Re(CO){sub 3}(py)(Hdmpz)(dmpz)] (8) were also synthesized. All species were characterized in solution by {sup 1}H-NMR spectroscopy, while the crystal structures of complexes 1, 3, 4 and 6 were determined by single-crystal X-ray diffraction analysis. The [(CO){sub 3}Re({mu}-pz){sub 2}({mu}-Br)Re(CO){sub 3}]{sup -} anion represents the first structurally characterized species containing rhenium(I) atoms bridged by mu-pyrazolate ligands. (orig.)

  9. Dose escalation study of rhenium-186 hydroxyethylidene diphosphonate in patients with metastatic prostate cancer

    Klerk, J.M.H. de (Dept. of Nuclear Medicine, Univ. Hospital, Utrecht (Netherlands)); Zonnenberg, B.A. (Oncology Section, Dept. of Internal Medicine, Univ. Hospital, Utrecht (Netherlands)); Schip, A.D. van het (Dept. of Nuclear Medicine, Univ. Hospital, Utrecht (Netherlands)); Dijk, A. van (Center for Hospital Pharmacy, Univ. Hospital, Utrecht (Netherlands)); Han, S.H. (Dept. of Nuclear Medicine, Univ. Hospital, Utrecht (Netherlands)); Quirijnen, J.M.S.P. (Dept. of Nuclear Medicine, Univ. Hospital, Utrecht (Netherlands)); Blijham, G.H. (Oncology Section, Dept. of Internal Medicine, Univ. Hospital, Utrecht (Netherlands)); Rijk, P.P. van (Dept. of Nuclear Medicine, Univ. Hospital, Utrecht (Netherlands))


    Rhenium-186 hydroxyethylidene diphosphonate ([sup 186]Re-HEDP) has been used for the palliative treatment of metastatic bone pain. A phase 1 dose escalation study was performed using [sup 186]Re-HEDP. Twenty-four patients with hormone-resistant prostate cancer entered the study. Each patient had at least four bone metastases and adequate haematological function. Groups of at least three consecutive patients were treated with doses starting at 1295 MBq and increasing to 3515 MBq (escalated in increments of 555 MBq). Thrombocytopenia proved to be the dose-limiting toxicity, while leucopenia played a minor role. Early death occurred in one patient (10 days after administration) without clear relationship to the [sup 186]Re-HEDP therapy. Transient neurological dysfunction was seen in two cases. Two patients who received 3515 MBq [sup 186]Re-HEDP showed grade 3 toxicity (thrombocytes 25-50 x 10[sup 9]/l), defined as unacceptable toxicity. After treatment alkaline phosphatase levels showed a transient decrease in all patients (mean: 26% [+-] 10% IU/l; range: 11%-44%). Prostate-specific antigen values showed a decline in eight patients, preceded by a temporary increase in three patients. From this study we conclude that the maximally tolerated dose of [sup 186]Re-HEDP is 2960 MBq. A placebo-controlled comparative study on the efficacy of [sup 186]Re-HEDP has been initiated. (orig.)

  10. Preparation of ultrafine rhenium powders by CVD hydrogen reduction of volatile rhenium oxides%采用CVD法还原挥发性铼的氧化物制备超细铼粉

    白猛; 刘志宏; 周乐君; 刘智勇; 张传福


    研究了一种以高铼酸铵为原料,采用化学气相沉积(CVD)制备超细铼粉的新方法.通过控制氧分压,使得NH4ReO7分解为具有挥发性的ReO4、Re2O7,再采用载气将其输运至还原区,经氢气还原生成超细铼粉.热力学计算表明,在NH4ReO7分解过程中,控制氧分压高于10-1.248 Pa时,Re2O7将不会分解为低价氧化物,DSC-TGA分析结果也证实了这一点.采用该方法制备的铼粉,粒度为100~800nm,D50为308nm,比表面积为4.37 m2/g,氧含量为0.45%.%A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials.In the process, volatile rhenium oxides,such as ReO4 and Re2O7,were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate,and carried into reduction zone by carrier gas,and there reduced into rhenium powders by hydrogen gas.Thermodynamic calculations indicated that Re2O7 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate.This result was further validated via DSC-TGA analysis of ammonium perrhenate.The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a D50 of 308 nm.The specific surface area and oxygen content were measured to be 4.37 m2/g and 0.45%,respectively.

  11. Rietveld refinement of the structures of 1.0 C-S-H and 1.5 C-S-H

    Battocchio, Francesco


    Low-Q region Rietveld analyses were performed on C-S-H synchrotron XRD patterns, using the software MAUD. Two different crystal structures of tobermorite 11 Å were used as a starting model: monoclinic ordered Merlino tobermorite, and orthorhombic disordered Hamid tobermorite. Structural modifications were required to adapt the structures to the chemical composition and the different interlayer spacing of the C-S-H samples. Refinement of atomic positions was done by using special constraints called fragments that maintain interatomic distances and orientations within atomic polyhedra. Anisotropic crystallite size refinement showed that C-S-H has a nanocrystalline disordered structure with a preferred direction of elongation of the nanocrystallites in the plane of the Ca interlayer. The quality of the fit showed that the monoclinic structure gives a more adequate representation of C-S-H, whereas the disordered orthorhombic structure can be considered a more realistic model if the lack of long-range order of the silica chain along the c-direction is assumed. © 2012 Elsevier Ltd. All rights reserved.

  12. Abundances and isotopic compositions of rhenium and osmium in pyrite samples from the Huaibei coalfield, Anhui, China

    Liu, Gaisheng; Chou, C.-L.; Peng, Z.; Yang, G.


    Two pyrite samples from the Shihezi Formation (Lower Permian), Huaibei coalfield, Anhui, China, have been analyzed for abundances and isotopic compositions of rhenium and osmium using negative thermal ion mass spectrometry. The Re-Os ages of the pyrites are 64.4 and 226 Ma, which are younger than the formation age of the coal seam. The pyrite samples may consist of pyrite formed at various stages during the history of coal formation. The ??Osvalues of the two pyrite samples are +17 and +18, respectively. Such high ??Osvalues are reported for the first time for recycles crustal materials from a sedimentary basin. ?? Springer-Verlag 2007.

  13. Use of the ORNL Tungsten-188/Rhenium-188 Generator for Preparation of the Rhenium-188 HDD/Lipiodol Complex for Transarterial Liver Cancer Therapy

    Knapp Jr, Russ F [ORNL; Jeong, J M [Seoul National University


    This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ({sup 188}W)/rhenium-188 ({sup 188}Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the {sup 188}Re-perrhenate bolus and preparation of {sup 188}Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The {sup 188}W/{sup 188}Re generator has a long useful shelf-life of several months and is a convenient on-site {sup 188}Re production system. {sup 188}Re has excellent therapeutic and imaging properties (T{sub 1/2} 16.9 hours; E{beta}{sub max} 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of {sup 188}Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of {sup 188}Re, several {sup 188}Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. {sup 188}Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of {sup 188}Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) {sup 188}W/{sup 188}Re generators. The handling of such high levels of {sup 188}Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (ie, 'As Low As Reasonably Achievable') principles must be followed. The ORNL generator provides consistently high {sup 188}Re yields (>75%) and low {sup 188}W parent breakthrough (<10{sup -3}%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require

  14. Layer-by-layer deposition of rhenium-containing hyperbranched polymers and fabrication of photovoltaic cells.

    Tse, Chui Wan; Man, Ka Yan Kitty; Cheng, Kai Wing; Mak, Chris S K; Chan, Wai Kin; Yip, Cho Tung; Liu, Zheng Tong; Djurisić, Aleksandra B


    Multilayer thin films were prepared by the layer-by-layer (LBL) deposition method using a rhenium-containing hyperbranched polymer and poly[2-(3-thienyl)ethoxy-4-butylsulfonate] (PTEBS). The radii of gyration of the hyperbranched polymer in solutions with different salt concentrations were measured by laser light scattering. A significant decrease in molecular size was observed when sodium trifluoromethanesulfonate was used as the electrolyte. The conditions of preparing the multilayer thin films by LBL deposition were studied. The growth of the multilayer films was monitored by absorption spectroscopy and spectroscopic ellipsometry, and the surface morphologies of the resulting films were studied by atomic force microscopy. When the pH of a PTEBS solution was kept at 6 and in the presence of salt, polymer films with maximum thickness were obtained. The multilayer films were also fabricated into photovoltaic cells and their photocurrent responses were measured upon irradiation with simulated air mass (AM) 1.5 solar light. The open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency of the devices were 1.2 V, 27.1 mu A cm(-2), 0.19, and 6.1x10(-3) %, respectively. The high open-circuit voltage was attributed to the difference in the HOMO level of the PTEBS donor and the LUMO level of the hyperbranched polymer acceptor. A plot of incident photon-to-electron conversion efficiency versus wavelength also suggests that the PTEBS/hyperbranched polymer junction is involved in the photosensitization process, in which a maximum was observed at approximately 420 nm. The relatively high capacitance, determined from the measured photocurrent rise and decay profiles, can be attributed to the presence of large counter anions in the polymer film.

  15. A novel series of rhenium-bipyrimidine complexes: synthesis, crystal structure and electrochemical properties.

    Chiozzone, Raúl; González, Ricardo; Kremer, Carlos; Cerdá, María Fernanda; Armentano, Donatella; De Munno, Giovanni; Martínez-Lillo, José; Faus, Juan


    Four novel rhenium complexes of formula [ReCl(4)(bpym)] (1), [ReBr(4)(bpym)] (2) PPh(4)[ReCl(4)(bpym)] (3) and NBu(4)[ReBr(4)(bpym)] (4) (bpym = 2,2'-bipyrimidine, PPh(4) = tetraphenylphosphonium cation and NBu(4) = tetrabutylammonium cation), have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of [ReX(4)(bpym)] molecules held together by van der Waals forces. In both complexes the Re(iv) central atom is surrounded by four halide anions and two nitrogen atoms of a bpym bidentate ligand in a distorted octahedral environment. The structures of 3 and 4 consist of [ReX(4)(bpym)](-) anions and PPh(4)(+) () or NBu(4)(+) (4) cations. The coordination sphere of the Re(iii) metal ion is the same as in 1 and 2, respectively. However, whereas the Re-X bonds are longer the Re-N bonds are shorter than in 1 and 2. This fact reveals that the bpym ligand forms a stronger bond with Re(iii) than with Re(iv) resulting in a stabilisation of the lower oxidation state. [ReX(4)(bpym)] complexes are easily reduced, chemically and electrochemically, to the corresponding [ReX(4)(bpym)](-) anions. A voltammetric study shows that the electron transference is a reversible process characterized by formal redox potentials of +0.19 V (1) and +0.32 V (2) vs. NHE, in acetonitrile as solvent.

  16. Dissolved rhenium in river waters: Insight into the chemical weathering of fossil organic carbon?

    Hilton, Robert; Gaillardet, Jerome


    The store of carbon in rock as fossil organic matter represents ~15x1021 g, which is almost 400 times the total amount of carbon present in the oceans and atmosphere. Oxidation of fossil organic carbon (FOC) during chemical weathering returns CO2 that was sequestered from the atmosphere in the geological past, back into the contemporary carbon cycle. Despite this recognition, the natural rates of FOC weathering are poorly constrained in the modern environment, as are the precise controls on its variability. This is primarily due to the difficultly in tracking the dissolved and gaseous carbon produced during FOC weathering, where biology and carbonate weathering mask its influence at a catchment-scale. Here we investigate the use of rhenium (Re) as a tracer of FOC weathering, focusing on a series of mountain catchments in Taiwan. We present dual methodology for determining dissolved Re content in river waters by ICP-MS, using pre-concentration and matrix removal via anion exchange chemistry and by direct analysis through standard-addition. Precision (2sigma) and accuracy at the ppt level are found to be better than 7%. In the 16 sampled catchments, the dissolved Re concentrations span the entire range from the published literature. We investigate the source of dissolved Re in the catchments using measurements of bedrocks and river sediments, and the comparative behavior of Re to major dissolved phases. A preliminary estimate of the Re budget derived from the weathering of FOC is presented, and the implications for the rates of FOC weathering discussed.

  17. Applying quality by design principles to the small-scale preparation of the bone-targeting therapeutic radiopharmaceutical rhenium-188-HEDP

    Lange, Rogier; Ter Heine, Rob; Van Der Gronde, Toon; Selles, Suzanne; De Klerk, John; Bloemendal, Haiko; Hendrikse, Harry


    Introduction Rhenium-188-HEDP (188Re-HEDP) is a therapeutic radiopharmaceutical for treatment of osteoblastic bone metastases. No standard procedure for the preparation of this radiopharmaceutical is available. Preparation conditions may influence the quality and in vivo behaviour of this product. I

  18. Optical and chemical properties of mixed-valent rhenium oxide films synthesized by reactive DC magnetron sputtering

    Murphy, Neil R.; Gallagher, Regina C.; Sun, Lirong; Jones, John G.; Grant, John T.


    Mixed-valent rhenium oxide thin films were deposited using reactive magnetron sputtering employing a metallic rhenium target within an oxygen-argon environment. The oxygen and argon flow rates were systematically varied, while the extinction coefficient, k, of the deposited layers was monitored using in situ spectroscopic ellipsometry. In situ monitoring was used to identify absorption features specific to ReO3, namely, the minimization of k brought on by the gap between interband absorption features in the UV at 310 nm and the onset of free electron absorption at wavelengths above 540 nm. Based on these results, oxygen flow ratios of 50% and 60% were shown to produce films having optical properties characteristic of ReO3, and thus, were selected for detailed ex situ characterization. Chemical analysis via X-ray photoelectron spectroscopy confirmed that all films consisted largely of ReO3, but had some contributions from Re2O3, ReO2 and Re2O7. Additional monitoring of the chemistry, as a function of environmental exposure time, indicated a correlation between structural instability and the presence of Re2O3 and Re2O7 in the films.

  19. Effect of Rhenium Addition on Wear Behavior of Cr-Al2O3 Metal Matrix Composites

    Chmielewski, Marcin; Piątkowska, Anna


    Materials for applications in the automotive industry are required to be strong, stiff, hard, light weight, and wear resistant, which is very difficult to achieve in the case of conventional materials. To meet all these diverse requirements, it is necessary to combine various types of materials (such as metals and ceramics). In the present study, the chromium and chromium-rhenium matrices were reinforced with aluminum oxide to obtain composite materials with improved wear resistance. The composites were fabricated by a powder metallurgy method. The effects of the rhenium addition and volume fraction of aluminum oxide on the wear rate and the friction coefficient of the composites at room temperature were examined in a ball-on-surface apparatus under dry conditions. The worn surfaces and debris were studied by scanning electron microscopy. The final values of the friction coefficient were 0.9 and 0.8 for the Cr-25%Al2O3 and Cr-40%Al2O3 composites, respectively. Alloying Cr matrix with Re improved wear resistance of composite but, at the same time, it caused an increase in its coefficient of friction.

  20. Redox induced electron transfer in doublet azo-anion diradical rhenium(II) complexes. Characterization of complete electron transfer series.

    Paul, Nandadulal; Samanta, Subhas; Goswami, Sreebrata


    Reactions of dirhenium decacarbonyl with the two azoaromatic ligands, L(a) = (2-phenylazo)pyridine and L(b) = (4-chloro-2-phenylazo)pyridine (general abbreviation of the ligands is L) afford paramagnetic rhenium(II) complexes, [Re(II)(L(*-))(2)(CO)(2)] (1) (S = 1/2 ground state) with two one-electron reduced azo-anion radical ligands in an octahedral geometrical arrangement. At room temperature (300 K) the complexes 1a-b, showed magnetic moments (mu(eff)) close to 1.94 mu(B), which is suggestive of the existence of strong antiferromagnetic interactions in the complexes. The results of magnetic measurements on one of the complexes, 1b, in the temperature range 2-300 K are reported. The above complexes showed two cathodic and two anodic responses in cyclic voltammetry where one-electron oxidation leads to an unusual redox event involving simultaneous reduction of the rhenium(II) and oxidation of the second ligand via intramolecular electron transfer. The oxidized complexes 1a(+) and 1b(+) are air stable and were isolated as crystalline solids as their tri-iodide (I(3)(-)) salts. The structures of the two representative complexes, 1b and [1b]I(3), as determined by X-ray crystallography, are compared. The anionic complexes, [1](-) and [1](2-) were characterized in solution by their spectral properties.

  1. Rhenium-188 Production in Hospitals, by W-188/Re-188 Generator, for Easy Use in Radionuclide Therapy

    Maria Argyrou


    Full Text Available Rhenium-188 (Re-188 is a high energy -emitting radioisotope obtained from the tungsten-188/rhenium-188 (W-188/Re-188 generator, which has shown utility for a variety of therapeutic applications in nuclear medicine, oncology, and interventional radiology/cardiology. Re-188 decay is accompanied by a 155 keV predominant energy -emission, which could be detected by -cameras, for imaging, biodistribution, or absorbed radiation dose studies. Its attractive physical properties and its potential low cost associated with a long-lived parent make it an interesting option for clinical use. The setup and daily use of W-188/Re-188 generator in hospital nuclear medicine departments are discussed in detail. The clinical efficacy, for several therapeutic applications, of a variety of Re-188-labeled agents is demonstrated. The high energy of the -emission of Re-188 is particularly well suited for effective penetration in solid tumours. Its total radiation dose delivered to tissues is comparable to other radionuclides used in therapy. Furthermore, radiation safety and shielding requirements are an important subject of matter. In the case of bone metastases treatment, therapeutic ratios are presented in order to describe the efficacy of Re-188 usage.

  2. Computational Material Modeling of Hydrated Cement Paste Calcium Silicate Hydrate (C-S-H) Chemistry Structure - Influence of Magnesium Exchange on Mechanical Stiffness: C-S-H Jennite


    material chemistry structure are studied following a molecular dynamics (MD) computational modeling methodology. Calcium ions are replaced with... chemistry structure. Conference Name: 1st Pan-American Conference on Computational Mechanics Conference Date: April 27, 2015 1st Pan-American Congress on...MODELING OF C-S-H Material chemistry level modeling following the principles and techniques commonly grouped under Computational Material Science is

  3. Rhenium and manganese bipyridine tricarbonyl catalysts for the electrochemical reduction of carbon dioxide

    Sampson, Matthew Dean

    Electrocatalytic reduction of carbon dioxide (CO2) is a profoundly challenging problem that is of interest, not only as a means of counteracting unsustainable emissions of CO2, but also as a method for the development of renewable fuels. Rhenium and manganese bipyridine tricarbonyl complexes are among the most active and robust catalysts for proton-coupled CO 2 reduction to carbon monoxide (CO). X- ray Absorption Spectroscopy studies are reported to reveal the electronic ground state of the Re catalysts, which help explain origins for high selectivity for CO2 reduction over proton reduction. Stopped-flow mixing in tandem with rapid-scan IR spectroscopy is utilized to probe the direct reaction of the Re catalysts with CO 2, observing, for the first time, the binding of CO2 to these catalysts. Manganese bipyridine catalysts are desirable, in comparison with their Re analogs, due to the earth-abundance of Mn and the ability for these catalysts to operate at lower overpotentials. One distinct difference between these Mn catalysts and their Re counterparts is a high tendency for dimerization after one-electron reduction, which contributes to the potential necessary to access their active state and to limiting their catalytic activity. Synthetic modification of the bipyridine ligand (by adding bulky mesityl groups) is used to completely eliminate dimerization for these Mn complexes, allowing the active catalyst to be generated at a 300 mV more positive potential than in typically Mn bipyridine complexes. CO2 reactivities in the presence of weak Bronsted acids, strong Bronsted acids, and Lewis acids have been explored in order to encourage this bulky Mn catalyst to reduce CO2 at low overpotentials. Mechanistic tools, including IR-spectroelectrochemistry, are described to gain insight into these unique catalytic processes. In order to further enhance stability and facilitate product separation, the use of metal-organic frameworks (MOFs) is explored as a means of anchoring


    HEHuanjie; ZHAODeqi; 等


    In this paper study on the property and mechanism of adsorpting rhenium from aqueous hydrochloric acid by using methyl phosphorous acid dimythyl heptyl ester levextrel resin(CL-P350) is reported.The effects of time,acidity,concentration of rhenium,and temperature on the adsorption of rhenium were investigated. The mechanism of adsorpting rhenium was discussed by chemical analytic and IR method,and dynamic adscrption and elution were studied.Experimental results show that the adsorption equilibration is reached in 4 min,the distribution coefficient(D) of Re(Ⅶ)increases with increase of concentration of HCl and reaches maximum 3.0-4.0moL/L HCl.ReO4- is taken up by ion association mechanism and can be described by Langmuir equation of the equilibrium state.The thermodynamic parameters in the adsorption process of ReO4- have been determined to be:ΔH=-29KJ/moL,ΔG=-25KJ/moL and ΔS=-13.5J/moL respectively.The saturation adsorption capacity of rhenium is 19.2mg/g when the solution containing 0.372g/L Re and 3.0mol/L HCl was passed through the resin column.The recovery percentage of rhenium is 98.4% while distilled water was used as an eluent.

  5. Solid-state thermolysis of a fac-rhenium(I) carbonyl complex with a redox non-innocent pincer ligand.

    Jurca, Titel; Chen, Wen-Ching; Michel, Sheila; Korobkov, Ilia; Ong, Tiow-Gan; Richeson, Darrin S


    The development of rhenium(I) chemistry has been restricted by the limited structural and electronic variability of the common pseudo-octahedral products fac-[ReX(CO)3L2] (L2 = α-diimine). We address this constraint by first preparing the bidentate bis(imino)pyridine complexes [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)3X] (X = Cl 2, Br 3), which were characterized by spectroscopic and X-ray crystallographic means, and then converting these species into tridentate pincer ligand compounds, [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)2X] (X = Cl 4, Br 5). This transformation was performed in the solid-state by controlled heating of 2 or 3 above 200 °C in a tube furnace under a flow of nitrogen gas, giving excellent yields (≥95 %). Compounds 4 and 5 define a new coordination environment for rhenium(I) carbonyl chemistry where the metal center is supported by a planar, tridentate pincer-coordinated bis(imino)pyridine ligand. The basic photophysical features of these compounds show significant elaboration in both number and intensity of the d-π* transitions observed in the UV/Vis spec tra relative to the bidentate starting materials, and these spectra were analyzed using time-dependent DFT computations. The redox nature of the bis(imino)pyridine ligand in compounds 2 and 4 was examined by electrochemical analysis, which showed two ligand reduction events and demonstrated that the ligand reduction shifts to a more positive potential when going from bidentate 2 to tridentate 4 (+160 mV for the first reduction step and +90 mV for the second). These observations indicate an increase in electrostatic stabilization of the reduced ligand in the tridentate conformation. Elaboration on this synthetic methodology documented its generality through the preparation of the pseudo-octahedral rhenium(I) triflate complex [(2,6-{2,6-Me2C6H3N=CPh}2C5H3N)Re(CO)2OTf] (7, 93 % yield). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Radio Supernovae: Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor Stars


    ar X iv :0 90 2. 40 59 v1 [ as tr o- ph .H E ] 2 4 Fe b 20 09 Radio Supernovae : Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor...FEB 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Radio Supernovae : Circum-Stellar Investigation (C.S.I...of Supernova Progenitor Stars 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

  7. Thruster-Assisted Position Mooring of C/S Inocean Cat I Drillship

    Bjørnø, Jon


    This thesis presents the development of a new research foundation into the Marine Cybernetic Laboratory, the C/S Inocean Cat I Drillship. This is a 1:90 scaled model of an Arctic drillship design by Inocean for Statoil. The C/S Inocean Cat I Drillship model is equipped with six Aero-naut Precision Schottel azimuth thrusters which are driven by six O.S. OMA-2820-950 motors and six Dynamixel MX-106R servo motors. To control the model a real time controller, CompactRIO, from National Instrum...

  8. A chiral rhenium complex with predicted high parity violation effects: synthesis, stereochemical characterization by VCD spectroscopy and quantum chemical calculations

    Saleh, Nidal; Roisnel, Thierry; Guy, Laure; Bast, Radovan; Saue, Trond; Darquié, Benoît; Crassous, Jeanne


    With their rich electronic, vibrational, rotational and hyperfine structure, molecular systems have the potential to play a decisive role in precision tests of fundamental physics. For example, electroweak nuclear interactions should cause small energy differences between the two enantiomers of chiral molecules, a signature of parity symmetry breaking. Enantioenriched oxorhenium(VII) complexes S-(-)- and R-(+)-3 bearing a chiral 2-methyl-1-thio-propanol ligand have been prepared as potential candidates for probing molecular parity violation effects via high resolution laser spectroscopy of the Re=O stretching. Although the rhenium atom is not a stereogenic centre in itself, experimental vibrational circular dichroism (VCD) spectra revealed a surrounding chiral environment, evidenced by the Re=O bond stretching mode signal. The calculated VCD spectrum of the R enantiomer confirmed the position of the sulfur atom cis to the methyl, as observed in the solid-state X-ray crystallographic structure, and showed the ...

  9. They Walked Together: Owen Barfield, Walter O. Field, Cecil Harwood, C.S. Lewis

    Hipolito Jane


    Full Text Available For C. S. Lewis, the walks that he took each Eastertide with Owen Barfield, Walter O. Field, and Cecil Harwood epitomized friendship. Although they were distinctly unlike in personality and were not all interested in the same things, the four “cretaceous perambulators” shared core ideals and aspirations. Their writings evidence the wonderful strengths of their friendship.

  10. Os diagramas de C. S. Peirce para as dez classes de signos

    Priscila Lena Farias


    Full Text Available Uma seção da Gramática Especulativa de C.S.Peirce - Dez classes de signos - recebeu, a partir de 1903, um importante tratamento diagramático. Neste artigo, são apresentados e discutidos dois diagramas desenvolvidos por Peirce para as dez classes, incluindo esboços desses modelos.

  11. Volatile sulphur compounds-forming abilities of lactic acid bacteria: C-S lyase activities.

    Bustos, Irene; Martínez-Bartolomé, Miguel A; Achemchem, Fouad; Peláez, Carmen; Requena, Teresa; Martínez-Cuesta, M Carmen


    Volatile sulphur compounds (VSCs) are of prime importance in the overall aroma of cheese and make a significant contribution to their typical flavours. Thus, the control of VSCs formation offers considerable potential for industrial applications. Here, lactic acid bacteria (LAB) from different ecological origins were screened for their abilities to produce VSCs from L-methionine. From the data presented, VSC-forming abilities were shown to be strain-specific and were correlated with the C-S lyase enzymatic activities determined using different approaches. High VSCs formation were detected for those strains that were also shown to possess high thiol-producing abilities (determined either by agar plate or spectrophotometry assays). Moreover, differences in C-S lyase activities were shown to correspond with the enzymatic potential of the strains as determined by in situ gel visualization. Therefore, the assessment of the C-S lyase enzymatic potential, by means of either of these techniques, could be used as a valuable approach for the selection of LAB strains with high VSC-producing abilities thus, representing an effective way to enhance cheese sulphur aroma compounds synthesis. In this regard, this study highlights the flavour forming potential of the Streptococcus thermophilus STY-31, that therefore could be used as a starter culture in cheese manufacture. Furthermore, although C-S lyases are involved in both biosynthetic and catabolic pathways, an association between methionine and cysteine auxotrophy of the selected strains and their VSCs-producing abilities could not be found.

  12. C. S. Peirce's Complementary and Transdisciplinary Conception of Science and Religion

    Brier, Søren


    C. S. Peirce was very mathematical, logical and empirical in the foundations of his thinking and he saw no principal limits to the knowledge obtainable by science. But the transdisciplinary view he developed differs substantially from the unity science of logical positivism in that he worked...

  13. Unusual nickel-mediated C-S cleavage of alkyl and aryl sulfoxides.

    Schaub, Thomas; Backes, Marc; Radius, Udo


    The first examples of transition metal mediated C-S cleavage of sulfoxides containing sp2- and sp3-hybridized carbon bonds attached to the sulfur atom and the first example of a structurally characterized complex featuring an oxygen-bound sulfinyl ligand are presented.

  14. An Integrated Perspective of Humanism and Supernaturalism for Education: C. S. Lewis's Version of Education

    Lee, Seung Chun


    This paper explores some theoretical reflections on the connection between C. S. Lewis's thoughts on the purpose and process of education and his understanding of supernatural human nature which has been relatively little explored. An introduction about Lewis's career as a college teacher blends into the background of this paper. It is followed by…

  15. Dorothy L. Sayers and C. S. Lewis: Christian Postmodernism beyond Boundaries

    Yuasa, Kyoko


    Modern critics do not consider science fiction and mystery novels to be "serious reading", but Dorothy L. Sayers and C. S. Lewis questioned the boundaries between "popular" and "serious" literature. Both Christian writers critically discuss the spiritual crisis of the modern world in each fiction genre. This paper…

  16. An Integrated Perspective of Humanism and Supernaturalism for Education: C. S. Lewis's Version of Education

    Lee, Seung Chun


    This paper explores some theoretical reflections on the connection between C. S. Lewis's thoughts on the purpose and process of education and his understanding of supernatural human nature which has been relatively little explored. An introduction about Lewis's career as a college teacher blends into the background of this paper. It is followed by…

  17. Oral Interpretation of C.S. Lewis'"Narnia Tales": A Refracting of "Pictures."

    Keefe, Carolyn

    "The Chronicles of Narnia" are a series of seven fairy tales written by C.S. Lewis that have become popular with both children and adults. Lewis points to five aspects of the fairy tale form that made the form suitable for expressing the images he saw. The aspects are: (1) no love interest; (2) no close psychology; (3) severe restraints…

  18. Paradise Lost and Found: Obedience, Disobedience, and Storytelling in C.S. Lewis and Philip Pullman.

    Wood, Naomi


    Considers how in the fantasy series "The Chronicles of Narnia" and "His Dark Materials," by C.S. Lewis and Philip Pullman respectively, the authors use symbols and themes from "Paradise Lost." Notes that each author's narrative choice uses his view of cosmic order to persuade readers that obedience should be…

  19. Oral Interpretation of C.S. Lewis'"Narnia Tales": A Refracting of "Pictures."

    Keefe, Carolyn

    "The Chronicles of Narnia" are a series of seven fairy tales written by C.S. Lewis that have become popular with both children and adults. Lewis points to five aspects of the fairy tale form that made the form suitable for expressing the images he saw. The aspects are: (1) no love interest; (2) no close psychology; (3) severe restraints…

  20. Paradise Lost and Found: Obedience, Disobedience, and Storytelling in C.S. Lewis and Philip Pullman.

    Wood, Naomi


    Considers how in the fantasy series "The Chronicles of Narnia" and "His Dark Materials," by C.S. Lewis and Philip Pullman respectively, the authors use symbols and themes from "Paradise Lost." Notes that each author's narrative choice uses his view of cosmic order to persuade readers that obedience should be…

  1. Effect of rhenium on short term oxidation of niobium based alloys for high temperature applications

    Sierra, Ruth M.

    The effect of adding Re to Nb-based alloys and is intended to analyze in depth the microstructures of Nb based alloys with Re, Si and Cr additions, in atomic percentages. The binary alloys (Nb-5Re, Nb-5Si and Nb-5Cr) reveal the formation of a single phase, NbSS, NbSS + Nb3Si and NbSS+NbCr2 respectively. The formation of the single phase was confirmed by TEM studies for the Nb-5Re alloy. Addition of Re to form ternary alloys, has helped in the formation of Nb5Si 3 and (Nb, Re) Cr2, in Nb-5Re- 5Si and Nb-5Re-5Cr respectively. Quaternary alloy Nb-5Re-5Si-5Cr has Nb5Si3, NbCr2 and NbSS. The oxidation behavior has been studied and the formation of the oxides has been characterized using XRD, SEM, EDS. Nb-Re-Si-Cr-X (Al, B, W) alloy system has been examined at temperatures between 700 and 1400°C in air. The continued work was to develop and discover a new materials system capable of replacing nickel based super alloys. Additions of aluminum were found to provide limited oxidation resistance. A discontinuous layer of Al2O3 and SiO2 was observed to form at all temperatures adapted for this study. Alloy containing aluminum additions were observed to suffer from pest oxidation at intermediate temperatures due to the development of Nb2O5. Poor oxidation resistance at intermediate temperatures for alloys with aluminum additions was attributed to a transformation in the structure of Nb2O5 formed. Pesting was observed at 900°C, consuming the metal completely. Additions of chromium were observed to increase oxidation resistance through the development of a layered oxide structure containing SiO2 and CrNbO4. Internal oxidation layer was observed to develop oxides in the midst of the phases formed. Boron addition has helped in the formation of the 3, 5 silicides, NbSS, and Laves phase. The combination of oxides of Nb2O5, CrNbO4 and SiO2 has helped improve the oxidation resistance of the alloy. Rhenium in this alloy has been a major element in terms of forming Re-oxides which has

  2. Influence of liposome forms of the rhenium compounds and cis-platin on thiol-disulfide coefficient in the rats’ blood

    I. V. Klenina


    Full Text Available Thiol-disulfide coefficient (TDC and its different modifications in model in vivo were studied. Introduction of the liposome forms of cluster rhenium compounds with organic ligands (CROL leads to both TDC increasing and to the constancy of the TDC. Thus, CROLs aren’t toxic agents and some compounds could mobilize organisms’ thiol defence system. Liposome form of cis-platin leads to the TDC decreasing. Important CROL capacities for its future medical treatment practice were shown.




    The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.

  4. Functionalized organoimidorhenium(V) complexes as potential radiopharamaceuticals: Syntheses of glycine derivatives and the structure determination of a rhenium analogue of chlorambucil

    Arterburn, J.B. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Chemistry and Biochemistry; Forgarty, I.M. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Chemistry and Biochemistry; Hall, K.A. [Los Alamos National Lab. (United States). CST Div.; Ott, K.C. [Los Alamos National Lab. (United States). CST Div.; Bryan, J.C. [Oak Ridge National Lab. (United States). CS Group


    Two important aspects, the synthesis of imido complexes of radioactive metal isotopes and the diversity that can be incorporated with this ligand, distinguish this communication. The multiply bonded organoimide ligand provides a new and powerful means of conjugating suitable radioisotopes of rhenium to biologically relevant molecules in the design of radiopharmaceuticals. Here stable isotope and {sup 188}Re-labeled analogues (1) of the anticancer drug chlorambucil were synthesized. (orig.)

  5. A click chemistry approach to 5,5'-disubstituted-3,3'-bisisoxazoles from dichloroglyoxime and alkynes: luminescent organometallic iridium and rhenium bisisoxazole complexes.

    van der Peet, Phillip L; Connell, Timothy U; Gunawan, Christian; White, Jonathan M; Donnelly, Paul S; Williams, Spencer J


    5,5'-Disubstituted-3,3'-bisisoxazoles are prepared in one step by the dropwise addition of aqueous potassium hydrogen carbonate to a mixture of dichloroglyoxime and terminal alkynes. The reaction exhibits a striking preference for the 5,5'-disubstituted 3,3'-bisisoxazole over the 4,5'-regioisomer. Organometallic iridium and rhenium bisisoxazole complexes are luminescent with emission wavelengths varying depending upon the identity of the 5,5'-substituent (phenyl, butyl).

  6. Efficient H{sub 2}-producing photo-catalytic systems based on cyclo-metallated iridium- and tricarbonyl-rhenium-diimine photosensitizers and cobaloxime catalysts

    Fihri, A.; Artero, V.; Fontecave, M. [Univ Grenoble 1, Lab Chim et Biol Metaux, Grenoble (France); Fihri, A.; Artero, V.; Fontecave, M. [CNRS, UMR 5249, F-75700 Paris (France); Fihri, A.; Artero, V.; Fontecave, M. [CEA, DSV, iRTSV, F-38054 Grenoble 9 (France); Pereira, A. [CEA, DRT, Liten, DTNM, LTS, Grenoble (France)


    Quantum yield values up to 16% under visible irradiation associated with high turnover frequencies ({approx} 50 h{sup -1}) and stability (up to 273 turnovers), characterize the new photo-catalytic systems for hydrogen production, based on diimine derivatives of ruthenium, cyclo-metallated iridium or tricarbonyl-rhenium as photosensitizers and cobaloxime H{sub 2}-evolving catalytic centers, which are among the most efficient molecular systems reported so far and compete with some platinum-based systems. (authors)

  7. Experimental approach to chemical identification of element 107 as eka-rhenium. Elaboration of procedure for continuous gas-thermochromatographic separation of radiorhenium

    Domanov, V.P.; Khyubener, Z.; Shalaevskij, M.R.; Timokhin, S.N.; Petrov, D.V.; Zvara, I.


    Gas-thermochromatographic behaviour of volatile oxygen-containing compounds of radiorhenium (/sup 177/Re), formed in the atmosphere of air at different content of aqueous vapours, has been studied. Technique of continuous thermochromatographic separation of radiorhenium from the products of nuclear reactions under the effect of heavy ions is developed. It is shown that not more than 10/sup -5/ part of ytterbium atoms-actinoid analogues, as well as of hafnium and tantalum-analogues of the elements 104 and 105 pass on thermogradient section of the column. It is found that under experimental conditions rhenium forms adsorption zone with the centre at the temperature of 100+-20 deg C. According to the evaluations of the time of atom transport from the target does not exceed 3s, and rhenium removal of the reaction column reaches 80%. The technique developed can be used for express selective separation of spontaneous fission isotopes of the element 107 as eka-rhenium from the mixture of nuclear reaction products with Z <= 107.

  8. Development of pharmaceuticals with radioactive rhenium for cancer therapy. Production of {sup 186}Re and {sup 188}Re, synthesis of labeled compounds and their biodistributions



    Production of the radioactive rhenium isotopes {sup 186}Re and {sup 188}Re, and synthesis of their labeled compounds have been studied together with the biodistributions of the compounds. This work was carried out by the Working Group on Radioactive Rhenium, consisting of researchers of JAERI and some universities, in the Subcommittee for Production and Radiolabeling under the Consultative Committee of Research on Radioisotopes. For {sup 186}Re, production methods by the {sup 185}Re(n,{gamma}){sup 186}Re reaction in a reactor and by the {sup 186}W(p,n){sup 186}Re reaction with an accelerator, which can produce nocarrier-added {sup 186}Re, have been established. For {sup 188}Re, a production method by the double neutron capture reaction of {sup 186}W, which produces a {sup 188}W/{sup 188}Re generator, has been established. For labeling of bisphosphonate, DMSA, DTPA, DADS, aminomethylenephosphonate and some monoclonal antibodies with the radioactive rhenium isotopes, the optimum conditions, including pH, the amounts of reagents and so on, have been determined for each compound. The biodistributions of each of the labeled compounds in mice have been also obtained. (author)

  9. The bispectrum of single-field inflationary trajectories with $c_{s} \

    Horner, Jonathan S


    The bispectrum of single-field inflationary trajectories in which the speed of sound of the inflationary trajectories $c_s$ is constant but not equal to the speed of light $c=1$ is explored. The trajectories are generated as random realisations of the Hubble Slow-Roll (HSR) hierarchy and the bispectra are calculated using numerical techniques that extends previous work. This method allows for out-of-slow-roll models with non-trivial time dependence and arbitrarily low $c_s$. The ensembles obtained using this method yield distributions for the shape and scale-dependence of the bispectrum and their relations with the standard inflationary parameters such as scalar spectral tilt $n_s$ and tensor-to-scalar ratio $r$. The distributions demonstrate the squeezed-limit consistency relations for arbitrary single-field inflationary models.

  10. Effects of glass fiber modified with calcium silicate hydrate (C-S-H(I)) reinforced cement

    Xin, M.; Zhang, L.; Ge, S.; Cheng, X.


    In this paper, calcium silicate hydrate (C-S-H(I)) and glass fiber modified with C-S-H(I) (SiF) at ambient temperature were synthesized. SiF and untreated fiber (OF) were incorporated into cement paste. Phase composition of C-S-H(I), SiF and OF was characterized by XRD. The surface morphologies were characterized by SEM. Flexural performance of fiber reinforced cement (FRC) at different curing ages was investigated. Results indicated that both SiF and OF could reinforce cement paste. SiF had a more positive effect on improving the flexural performance of FRC than OF. The strength of SiF reinforced cement was 11.48MPa after 28 days curing when fiber volume was 1.0%, 12.55% higher than that of OF reinforced cement. The flexural strength increased with the addition of fiber volume. However, the large dosage of fiber might cause a decrease in flexural strength of FRC.

  11. A Method for Semi-quantitative Analysis of C-S-H Gel in a Blended Cement Paste


    An amended method for accurate measuring the quantity of calcium silicate hydrate(C-S-H) in pure cement paste and blended cement paste by water adsorption was made, which based on R.A.Olson's method. Two improvements to this method, such as using C-S-H gel by hydro-thermal synthesis as standard sample and the stoichiometry of C-S-H gel is partitioned based on hydration time and the amount of mineral admixture. The result of C-S-H gel content in pure cement paste and blended cement paste is higher than by R.A.Olson's method.

  12. Rhenium complexes of chromophore-appended dipicolylamine ligands: syntheses, spectroscopic properties, DNA binding and X-ray crystal structure

    Mullice, L.A.; Buurma, N.J.; Pope, S.J.A. [Cardiff Univ., School of Chemistry (United Kingdom); Laye, R.H. [Sheffield Univ., Dept. of Chemistry (United Kingdom); Harding, L.P. [Huddersfield Univ., School of Biological and Chemical Sciences (United Kingdom)


    The syntheses of two chromophore-appended dipicolylamine-derived ligands and their reactivity with penta-carbonyl-chloro-rhenium have been studied. The resultant complexes each possess the fac-Re(CO){sub 3} core. The ligands L{sup 1} 1-[bis(pyridine-2-yl-methyl)amino]methyl-pyrene and L{sup 2} 2-[bis(pyridine-2-yl-methyl)amino]methyl-quinoxaline were isolated via a one-pot reductive amination in moderate yield. The corresponding rhenium complexes were isolated in good yields and characterised by {sup 1}H NMR, MS, IR and UV-Vis studies. X-Ray crystallographic data were obtained for fac-{l_brace}Re(CO){sub 3}(L{sup 1}){r_brace}(BF{sub 4}), C{sub 34}H{sub 26}BF{sub 4}N{sub 4}O{sub 3}Re: monoclinic, P2(1)/c, a 18.327(2) Angstroms, {alpha} = 90.00 degrees, b 14.1537(14) Angstroms, {beta}96.263(6) degrees, c = 23.511(3) Angstroms, {gamma} 90.00 Angstroms, 6062.4(11) (Angstroms){sup 3}, Z=8. The luminescence properties of the ligands and complexes were also investigated, with the emission attributed to the appended chromophore in each case. Isothermal titration calorimetry suggests that fac-{l_brace}Re(CO){sub 3}(L{sup 1}){r_brace}(BF{sub 4}) self-aggregates cooperatively in aqueous solution, probably forming micelle-like aggregates with a cmc of 0.18 mM. Investigations into the DNA-binding properties of fac-{l_brace}Re(CO){sub 3}(L{sup 1}){r_brace}(BF{sub 4}) were undertaken and revealed that fac-{l_brace}Re(CO){sub 3}(L{sup 1}){r_brace}(BF{sub 4}) binding to fish sperm DNA (binding constant 1.5 {+-} 0.2 * 10{sup 5} M{sup -1}, binding site size 3.2 {+-} 0.3 base pairs) is accompanied by changes in the UV-Vis spectrum as typically observed for pyrene-based intercalators while the calorimetrically determined binding enthalpy (-14 {+-} 2 kcal mol{sup -1}) also agrees favourably with values as typically found for intercalators. (authors)

  13. Structural insights into catalysis by βC-S lyase from Streptococcus anginosus.

    Kezuka, Yuichiro; Yoshida, Yasuo; Nonaka, Takamasa


    Hydrogen sulfide (H(2)S) is a causative agent of oral malodor and may play an important role in the pathogenicity of oral bacteria such as Streptococcus anginosus. In this microorganism, H(2)S production is associated with βC-S lyase (Lcd) encoded by lcd gene, which is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the α,β-elimination of sulfur-containing amino acids. When Lcd acts on L-cysteine, H(2)S is produced along with pyruvate and ammonia. To understand the H(2)S-producing mechanism of Lcd in detail, we determined the crystal structures of substrate-free Lcd (internal aldimine form) and two reaction intermediate complexes (external aldimine and α-aminoacrylate forms). The formation of intermediates induced little changes in the overall structure of the enzyme and in the active site residues, with the exception of Lys234, a PLP-binding residue. Structural and mutational analyses highlighted the importance of the active site residues Tyr60, Tyr119, and Arg365. In particular, Tyr119 forms a hydrogen bond with the side chain oxygen atom of L-serine, a substrate analog, in the external aldimine form suggesting its role in the recognition of the sulfur atom of the true substrate (L-cysteine). Tyr119 also plays a role in fixing the PLP cofactor at the proper position during catalysis through binding with its side chain. Finally, we partly modified the catalytic mechanism known for cystalysin, a βC-S lyase from Treponema denticola, and proposed an improved mechanism, which seems to be common to the βC-S lyases from oral bacteria.

  14. The embodiment of value: C.S. Sherrington and the cultivation of science.

    Smith, R


    The paper examines the ruputation of C.S. Sherrington as both eminent physiologist and eminent representative of scientific culture. It describes Sherrington's 'figurehead' status. In his career, research and personal manner, he embodied a life of science, not only in opposition to humanistic values but in fact appearing to be the highest achievement of those values. An analysis of Sherrington's research, of his lectures on Man on His Nature and of his poetry supports this account. The paper uses Sherrington's reputation to describe the values of an establishment group of English-speaking scientists and physicians in the 1930s and 1940s.

  15. Polarization of Inclusive $\\Lambda_{c}$'s in a Hybrid Model

    Goldstein, G R


    A hybrid model is presented for hyperon polarization that is based on perturbative QCD subprocesses and the recombination of polarized quarks with scalar diquarks. The updated hybrid model is applied to $p+p\\to \\Lambda +X$ and successfully reproduces the detailed kinematic dependence shown by the data. The hybrid model is extended to include pion beams and polarized $\\Lambda_c$'s. The resulting polarization is found to be in fair agreement with recent experiments. Predictions for the polarization dependence on $x_F$ and $p_T$ is given.

  16. A concise, efficient synthesis of sugar-based benzothiazoles through chemoselective intramolecular C-S coupling

    Shen, Chao


    Sugar-based benzothiazoles are a new class of molecules promising for many biological applications. Here, we have synthesized a wide range of sugar-based benzothiazoles from readily accessible glycosyl thioureas by chemoselective, palladium-catalyzed C-S coupling reactions. Corroborated by theoretical calculations, a mechanistic investigation indicates that the coordination to the palladium by a pivaloyl carbonyl group and the presence of intramolecular hydrogen bonding play important roles in the efficiency and chemoselectivity of reaction. These fluorescent glycoconjugates can be observed to readily enter mammalian tumor cells and exhibit potential in vitro antitumor activity. This journal is © The Royal Society of Chemistry 2012.

  17. C. S. Peirce’s Semiotic Answer to the Riddle of Consciousness

    Brier, Søren

    A scientific explanation of consciousness that is not partially based on phenomenology seems logically impossible. C.S. Peirce’s pragmaticist semiotics attempts to bridge the gap between natural sciences and humanities by combining a phenomenological approach with an evolutionary and realistic...... understanding of nature and society in the development of a new transdisicplinary and evolutionary theory of meaning and logic in a semiotic theory of mind and consciousness. Though a contributor to the development of modern logic and science Peirce, through inventing a semiotics that embraced phenomenology...

  18. Regio-selectivity of the Oxidative C-S Bond Formation in Ergothioneine and Ovothiol Biosyntheses

    Song, Heng; Leninger, Maureen; Lee, Norman


    Ergothioneine (5) and ovothiol (8) are two novel thiol-containing natural products. Their C-S bonds are formed by oxidative coupling reactions catalyzed by EgtB and OvoA enzymes, respectively. In this work, it was discovered that besides catalyzing the oxidative coupling between histidine and cysteine (1 → 6 conversion), OvoA can also catalyze a direct oxidative coupling between hercynine (2) and cysteine (2 → 4 conversion), which can shorten the ergothioneine biosynthetic pathway by two steps. PMID:24016264

  19. Regioselectivity of the oxidative C-S bond formation in ergothioneine and ovothiol biosyntheses.

    Song, Heng; Leninger, Maureen; Lee, Norman; Liu, Pinghua


    Ergothioneine (5) and ovothiol (8) are two novel thiol-containing natural products. Their C-S bonds are formed by oxidative coupling reactions catalyzed by EgtB and OvoA enzymes, respectively. In this work, it was discovered that in addition to catalyzing the oxidative coupling between histidine and cysteine (1 → 6 conversion), OvoA can also catalyze a direct oxidative coupling between hercynine (2) and cysteine (2 → 4 conversion), which can shorten the ergothioneine biosynthetic pathway by two steps.

  20. [Symbol-based communication in non-human primates: a C. S. Peirce's semiotic analysis].

    Queiroz, João


    Are (or were) there any other symbolic species? This question has been addressed by researchers from many different fields and is responsible for a historical controversy on the existence of a threshold between "symbolic creatures" vs "simple forms of language creatures". According to the mainstream ethology and comparative psychology only the Homo sapiens is cognitively equiped to produce and interpret symbols. Here, I introduce an empirically testable model of symbolic semiosis ("symbolic action of sign") supported by C.S.Peirce logical-phenomenological theory of categories. I suggest that a specific sign-user pattern of behavior, observed in non-human primate communication, indicate a transition from indexical to symbolic semiosis.

  1. Characterization of C-S Lyase from C. diphtheriae: A Possible Target for New Antimicrobial Drugs

    Alessandra Astegno


    Full Text Available The emergence of antibiotic resistance in microbial pathogens requires the identification of new antibacterial drugs. The biosynthesis of methionine is an attractive target because of its central importance in cellular metabolism. Moreover, most of the steps in methionine biosynthesis pathway are absent in mammals, lowering the probability of unwanted side effects. Herein, detailed biochemical characterization of one enzyme required for methionine biosynthesis, a pyridoxal-5′-phosphate (PLP- dependent C-S lyase from Corynebacterium diphtheriae, a pathogenic bacterium that causes diphtheria, has been performed. We overexpressed the protein in E. coli and analyzed substrate specificity, pH dependence of steady state kinetic parameters, and ligand-induced spectral transitions of the protein. Structural comparison of the enzyme with cystalysin from Treponema denticola indicates a similarity in overall folding. We used site-directed mutagenesis to highlight the importance of active site residues Tyr55, Tyr114, and Arg351, analyzing the effects of amino acid replacement on catalytic properties of enzyme. Better understanding of the active site of C. diphtheriae C-S lyase and the determinants of substrate and reaction specificity from this work will facilitate the design of novel inhibitors as antibacterial therapeutics.

  2. A remark on nano-particle stability of cement C-S-H gel

    Ficker, Tomáš; Len, Adél; Martišek, Dalibor


    Hydrated pastes of ordinary Portland cement prepared with different water-to-cement ratios were investigated by using the small-angle neutron scattering technique in the region of Q ∈ (0.0045, 0.11) Å-1. Samples of cement pastes were subjected to non-standard hydration conditions using a mix with D2O, low RH, and water-to-cement ratios spread over a very wide interval (0.4; 1.4). The investigation was focused on testing the structural stability of nano-metric particles in the cement C-S-H gel. Owing to the high structural stability of these nano-particles, their average diameter might be used as a microscopic parameter characterizing the nano-metric structure of C-S-H gels. The average diameter of the nano-particles of the studied ordinary Portland cement CEMI 42.5 R-SC was found to be close to the value of 4.2 nm and independent of the water-to-cement ratios.

  3. Solvent extraction of heptavalent technetium and rhenium by tributyl phosphate. Consolidated Fuel Reprocessing Program and Basic Energy Sciences Programs

    Pruett, D.J.


    The literature pertaining to the solvent extraction of heptavalent technetium and rhenium from aqueous solution by tributyl phosphate (TBP) has been compiled, critically evaluated, and supplemented with new data in some areas. The effects of adding mineral acids, alkali metal nitrates, alkali metal chlorides, uranyl nitrate, thorium nitrate, and plutonium(IV) nitrate to these systems were also examined. Discussions of the possible nature of the organic-phase complexes are presented, along with values of,,, and the equilibrium constant for the extraction reaction in several systems. Mathematical models correlating the distribution behavior over a wide range of conditions were also developed. Equations are given for calculating the distribution coefficients for the extraction of Re(VII) or Tc(VII) from 0.2 to 4 M HCl by 0.339 to 2.90 M TBP at 298 to 333/sup 0/K. Equations are given for calculating the distribution coefficients under the same conditions, but with HNO/sub 3/ (instead of HCl) present in the aqueous phase. 28 references, 27 figures, 3 tables.

  4. Numerical ellipsometry: Examination of growing nickel and rhenium thin films using n-k plane analysis and effective numerical substrates

    Urban, F.K., E-mail:; Barton, D.


    Useful thin film information may be obtained using ellipsometry data recorded during film growth. In cases in which the growing film overlies a substrate already coated with other films, it is possible to use a model which includes prior knowledge of the optical properties and layer thicknesses of all underlying films and the substrate. However, accuracy of the analysis is limited by imprecision in knowledge of the underlying structure and is not possible if the underlying material structure is unknown. These problems may be addressed by substituting a four-variable “numerical substrate” in place of the underlying materials. The “numerical substrate” exactly mathematically replaces a model of the physical substrate. It is represented by two effective optical indices which are independent of the growing film and dependent only upon light incidence angle and wavelength. The method may be implemented with a set of five measurements at a single wavelength and incidence angle or a set of three measurements at each of two incidence angles. Measurements may be made in-situ during film growth or ex-situ using “step deposited” films of different thicknesses. The work presented here is to demonstrate the method for nickel and rhenium films deposited on a BK7 substrate by Yamamoto using ion sputtering. - Highlights: • Ellipsometry data were taken in-situ. • Data are single angle, single wavelength. • Film nucleation layers are strongly vertically inhomogeneous. • Upper layers were nearly homogeneous. • Solutions used five measurements at different times.

  5. Activation cross-sections of deuteron induced nuclear reactions on rhenium up to 40 MeV

    Ditrói, F., E-mail: [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC), Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)


    Highlights: ► Excitation function measurement of deuteron induced reactions on rhenium up to 40 MeV. ► Model code calculations with EMPIRE-D, ALICE-D and TALYS (TENDL-2011). ► Integral production yield calculation. ► Thin layer activation (TLA) curves; {sup 185}Os and {sup 186}Re. -- Abstract: As a part of a thorough work of excitation functions on deuteron induced reactions, experimental cross-sections of {sup 185,183m,183g,182}Os and {sup 188,186,184m,184g,183}Re activation products on {sup nat}Re were measured up to 40 MeV for the first time with the activation method using a stacked foil irradiation technique and high resolution γ-spectrometry. Comparison with the former results of other laboratories and with the predictions of the ALICE-IPPE and EMPIRE-3 model codes, modified for improved calculations for deuteron reactions, and with data in the TENDL-2011 library are also presented. Thick target yields were given deduced from our experimental cross-sections and compared with the few literature values. For practical applications (thin layer activation) also activity versus depth distributions were calculated for selected isotopes.

  6. Influence of rhenium speciation on the stability and activity of Re/Pd bimetal catalysts used for perchlorate reduction.

    Choe, Jong Kwon; Shapley, John R; Strathmann, Timothy J; Werth, Charles J


    Recent work demonstrates reduction of aqueous perchlorate by hydrogen at ambient temperatures and pressures using a novel rhenium-palladium bimetal catalyst immobilized on activated carbon (Re/Pd-AC). This study examines the influence of Re speciation on catalyst activity and stability. Rates of perchlorate reduction are linearly dependent on Re content from 0-6 wt %, but no further increases are observed at higher Re contents. Surface-immobilized Re shows varying stability and speciation both in oxic versus H(2)-reducing environments and as a function of Re content. In oxic solutions, Re immobilization is dictated by sorption of the Re(VII) precursor, perrhenate (ReO(4)(-)), to activated carbon via electrostatic interactions. Under H(2)-reducing conditions, Re immobilization is significantly improved and leaching is minimized by ReO(4)(-) reduction to more reduced species on the catalyst surface. X-ray photoelectron spectroscopy shows two different Re binding energy states under H(2)-reducing conditions that correspond most closely to Re(V)/Re(IV) and Re(I) reference standards, respectively. The distribution of the two redox states varies with Re content, with the latter predominating at lower Re contents where catalyst activity is more strongly dependent on Re content. Results demonstrate that both lower Re contents and the maintenance of H(2)-reducing conditions are key elements in stabilizing the active Re surface species that are needed for sustained catalytic perchlorate treatment.

  7. Photo-reduction of CO2 Using a Rhenium Complex Covalently Supported on a Graphene/TiO2 Composite.

    Cui, Shi-Cong; Sun, Xue-Zhong; Liu, Jin-Gang


    One of the promising solutions for decreasing atmospheric CO2 is artificial photosynthesis, in which CO2 can be photoconverted into solar fuels. In this study, a rhenium complex Re(PyBn)(CO)3 Cl (PyBn=1-(2-picolyl)-4-phenyl-1H-1,2,3-triazole) was covalently grafted onto the surface of reduced graphene oxide (rGO). This was further combined with TiO2 to fabricate a novel catalyst composite TiO2 -rGO-Re(PyBn)(CO)3 Cl for CO2 photo-reduction. This hybrid composite demonstrated high selectivity conversion of CO2 into CO under xenon-lamp irradiation. Compared with the unsupported homogeneous catalyst Re(PyBn)(CO)3 Cl, the covalent immobilized catalyst composite TiO2 -rGO-Re(PyBn)(CO)3 Cl enhanced the turnover number six times and significantly improved catalyst stability. During the process of CO2 photo-reduction, intermediate species with lifetimes longer than hundreds of microseconds were observed and the formation of CO products was revealed using timeresolved infrared spectroscopy. A plausible mechanism for CO2 photo-reduction by the TiO2 -rGO-Re(PyBn)(CO)3 Cl catalyst composite has been suggested. The obtained results have implications for the future design of efficient catalyst composites for CO2 photo-conversion.

  8. Nature of active centers and mechanism of olefin metathesis on applied oxide catalysts of molybdenum, tungsten and rhenium

    Kadushin, A.A. (USSR Academy of Sciences); Aliyev, R.K.; Krylov, O.V.; Andreyev, A.A.; Yedreva-Kardzhiyeva, R.M.; Shopov, D.M.


    The authors undertook a systematic study of the effects of the carrier, activation conditions and the reaction itself on the formation and structure of active centers. Spectral characteristics of the systems studied were compared by infrared, ultraviolet, X-ray-electron and electron absorption spectroscopy, and X-ray-phase and chromatographic analyses. Catalytic activity in a metathesis reaction of propylene and butene-1 was tested in a quartz flow reactor at atmospheric pressure in a temperature range of 25-600/sup 0/C, with contact time of 3-50 seconds. The deposited oxide catalysts of the title minerals are discussed in terms of preparing the catalysts, studying their activity, and observing optical spectra. Tungsten ions were found to reduce at higher temperatures than molbydenum ions. Olefin treatment brought reduction of rhenium to lower oxidation levels. The low activities of Re/sub 2/O/sub 7//MgO at low temperatures is related to difficult electron transfer. The studies indicated the presence of a mobile center in the metathesis of olefins for oxide catalysis of all 3 title minerals, which is dependent on the chemical nature of the carrier and its crystalline structure.

  9. A new amperometric glucose biosensor based on screen printed carbon electrodes with rhenium(IV - oxide as a mediator



    Full Text Available Rhenium(IV-oxide, ReO2, was used as a mediator for carbon paste (CPE and screen printed carbon (SPCE electrodes for the catalytic amperometric determination of hydro-gen peroxide, whose overpotential for the reduction could be lowered to -0.1 V vs. Ag/AgCl in flow injection analysis (FIA using phosphate buffer (0.1 M, pH=7.5 as a carrier. For hydrogen peroxide a detection limit (3σ of 0.8 mg L-1 could be obtained.ReO2-modified SPCEs were used to design biosensors with a template enzyme, i.e. glucose oxidase, entrapped in a Nafion membrane. The resulting glucose sensor showed a linear dynamic range up to 200 mg L-1 glucose with a detection limit (3σ of 0.6 mg L-1. The repeatability was 2.1 % RSD (n = 5 measurements, the reproducibility 5.4 % (n = 5 sensors. The sensor could be applied for the determination of glucose in blood serum in good agreement with a reference method.

  10. Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications

    Charit, Indrajit; Butt, Darryl; Frary, Megan; Carroll, Mark


    This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

  11. Nuclear magnetic and quadrupole resonance in metallic powders in the presence of strong quadrupole interaction: Rhenium metal

    Dimitropoulos, C.; Maglione, M.; Borsa, F.


    The nuclear-magnetic-resonance and nuclear-quadrupole-resonance (NQR-NMR) spectra of /sup 187/Re and /sup 185/Re in a powder of rhenium metal were measured in the temperature range 5--10 K both in zero field and with an external magnetic field. The zero-field NQR spectrum is severely broadened by a nonuniform distribution of quadrupole interactions. The average quadrupole coupling frequencies measured at 5 K are, for the two isotopes, Q/ = 39 +- 0.2 MHz (/sup 187/Re) and Q/ = 40.8 +- 0.3 MHz (/sup 185/Re). The spectra obtained in the presence of an external magnetic field can be interpreted satisfactorily in terms of transitions among the eigenstates of the full Hamiltonian (Zeeman plus quadrupolar). Measurements of relaxation rates yield T/sub 1/T = 0.03 sK, indicating a relaxation mechanism driven by the hyperfine interaction with the conduction electrons. The feasibility of NQR-NMR studies in small metal particles in the presence of strong inhomogeneous quadrupole interactions is assessed

  12. Structured layer of rhenium dye on SiO₂ and TiO₂ surfaces by Langmuir-Blodgett technique.

    Joo, Yongho; Spalenka, Josef W; McElhinny, Kyle M; Schmitt, Samantha K; Evans, Paul G; Gopalan, Padma


    We demonstrate the Langmuir-Blodgett assembly of two rhenium-bipyridine complexes containing a flexible or an aromatic bridge, and transfer of the monolayer to SiO2 and single crystal TiO2 substrates. Both of the complexes (ReEC and Re2TC) have a hydrophilic carboxylic acid group, which preferentially anchors into the water subphase, and forms stable monolayers at surface pressures up to 40 mN/m. The optimum conditions for the formation of complete monolayers of both ReEC and Re2TC were identified through characterization of the morphology by atomic force microscopy (AFM), the thickness by ellipsometry, and the surface coverage by X-ray photoelectron spectroscopy (XPS). X-ray reflectivity measurements (XRR) are consistent with the orientation of the molecules normal to the substrate, and their extension to close to their calculated maximum length. Parameters derived from XRR analysis show that there is a higher packing density for Re2TC monolayers than for ReEC monolayers, attributable to the more rigid bridge in the Re2TC molecule.

  13. Pharmacokinetic properties of new antitumor radiopharmaceutical on the basis of diamond nanoporous composites labeled with rhenium-188

    Petriev, V. M.; Tishchenko, V. K.; Kuril’chik, A. A.; Skvortsov, V. G.


    Today the development of address therapeutic radionuclide delivery systems directly to tumor tissue is of current interest. It can be achieved by the design of drug containers of specific sizes and shapes from carbon-based composite materials. It will be allowed to enhance the efficacy of anticancer therapy and avoid serious side effects. In this work we studied the pharmacokinetic properties of nanodiamond nanoporous composite labeled with rhenium-188 in rats with hepatocholangioma PC-1 after intratumoral injection. It was established that substantial part of injected radioactivity remained in tumor tissue. Within three hours after 188Re-nanoporous composites injection activity in tumor constituted 79.1–91.3% of injected dose (ID). Then activity level declined to 45.9% ID at 120 hours. No more than 1.34% ID entered the bloodstream. In soft organs and tissues, except thyroid gland, the content of compound didn’t exceed 0.3% ID/g. The highest activity in thyroid gland was 6.95% ID/g. In conclusion, received results suggest 188Re-nanoporous composites can be promising radionuclide delivery systems for cancer treatment.

  14. Synthesis, characterization and structural investigation of new rhenium-oxo complexes containing bidentate phosphine ligands: an exploration of chirality and conformation in chelate rings of small and large bite angle ligands

    Parr, M.L.; Perez-Acosta, C. [Trinity College, Dept. of Chemistry, Hartford, CT (United States); Faller, J.W. [Yale Univ., Dept. of Chemistry, New Haven, CT (United States)


    The new rhenium complexes, [ReOCl{sub 3}(L{sub 2})], incorporating bidentate organophosphorus ligands [L{sub 2} = dppe-F{sub 20} (the per-fluorinated analog of dppe), xantphos, rac-BINAP, biphep and DPEphos] were successfully synthesized using [ReOCl{sub 3}(AsPh{sub 3}){sub 2}] as the precursor. The complexes were characterized by IR, {sup 1}H and {sup 31}P NMR, elemental analysis and X-ray diffraction. The X-ray structures reveal a distorted octahedral geometry with a facial arrangement of chloro ligands and an axial rhenium-oxo group. (authors)

  15. Characterization of Pozzolanic Reaction and Its Effect on the C-S-H Gel in Fly Ash-cement Paste

    WANG Lei; HE Zhen; CAI Xinhua


    High resolution solid-state 29Si MAS NMR, combined with XRD, SEM and FTIR were used to characterize the pozzolanic activity of FA, type of main pozzolanic reaction products, and the effect of pozzolanic reaction on the C-S-H microstructure in fly ash-cement (FC) paste. The experimental results indicate that in the hydrated FC paste with 30% dosage of FA at 3 d, FA partially participated in the pozzolanic reaction, while, at 120 d, FA largely reacts. During the hydration of FCpaste at laboratory temperature, the pozzolanic reaction products are C-S-H gel rather than zeolitic gel.Moreover, after the covalent bonds of Si-O-Si, Si-O-Al and Al-O-Al in the structure of FA are broken,monosilicates Si-OH and Al-OH groups form, these chemical species can connect C-S-H dimers, thus producing more Al-free C-S-H and aluminous C-S-H than in the plain cement paste. The increased content of Al for Si substitution in the bridging tetrahedra of C-S-H may decrease the stability of C-S-H, which results in a rather obvious loss in the mechanical strength of hardened FC paste.

  16. Compositional Evolution of Calcium Silicate Hydrate (C-S-H) Structures by Total X-Ray Scattering

    Soyer-Uzun, Sezen


    High-energy X-ray diffraction was employed to study the structural characteristics of a set of C-S-H samples with 0.6 ≤ C/S a;circ 1.75. It has been observed that Si is tetrahedrally coordinated to O for all samples irrespective of chemical composition and the Ca-O coordination number gradually decreases from ∼7 to ∼6 with increasing C/S ratio. This suggests that the C-S-H structure evolves from a tobermorite-like structure into a jennite-like structure as a function of increasing C/S ratio as the interlayer space decreases from ∼1.3 to ∼1 nm. Evolution of these short- and medium-range order structural characteristics in the C-S-H system is associated with the alteration of the Ca-O layers and silicate depolymerization with increasing C/S. © 2011 The American Ceramic Society.

  17. High-resolution metallic magnetic calorimeters for {beta}-spectroscopy on {sup 187}rhenium and position resolved X-ray spectroscopy

    Porst, Jan-Patrick


    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for {beta}-endpoint spectroscopy on {sup 187}rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 {mu}s could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than {delta}E{sub FWHM}<5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

  18. Note on predictions for c s bar quarkonia using a three-loop static potential

    Green, Noah; Repko, Wayne W.; Radford, Stanley F.


    We extend our treatment of the spectroscopy and decays of the charm-strange quarkonium system to include the effect of using the full three-loop QCD correction to the static short distance potential. As before, our potential model consists of the relativistic kinetic energy term, a scalar linear confining term including its relativistic corrections and the perturbative QCD spin-dependent terms. A set of unperturbed wave functions for the various states is obtained using a variational technique that is further constrained by requiring that the wave functions also satisfy the relativistic virial theorem. These are then used in a perturbative treatment of the potential to fit the mass spectrum of the c s bar system and calculate the radiative decay widths. Our results accurately describe the Ds spectrum and are compatible with the little data that is available for the radiative decays of the Ds states.

  19. Dark science and techno-utopia: the conservative approach of C. S. Lewis

    Mario Ramos Vera


    Full Text Available The rise of scientific, illustrated and progressive late nineteenth century utopias triggered proposals with alternative meanings. Some of those were articulated through a conservative thought as well as a christian, transcendent and otherworldly metanarrative. C. S. Lewis, for example, provided his answer to the techno-utopia in his essay The Abolition of Man as well as in the novel That Hideous Strength —conclusion of the Cosmic Trilogy (or Ransom Trilogy. We will introduce his challenge through three different arguments: (1 contrary to the project of personality conditioning , education is a link of continuity with the past and of respect for tradition; (2 in the light of the methodological atheism of these dystopias elicited the metaphysical and transcendent lewisian foundation of the imperfection of the human condition; (3 He will reply to the arrogance of social and political engineering by reducing power to a technical criterion of instrumental knowledge with the modest language of politics.

  20. Consciousness and C. S. Peirce’s Answer to the Riddle of the Sphinx

    Brier, Søren


    on phenomenology seems logically impossible therefore the many (unsuccessful) attempts to naturalize. C.S. Peirce’s pragmaticist semiotics attempts to bridge the gap between natural sciences and humanities by combining a phenomenological approach with an evolutionary and realistic understanding of nature...... some of the first to integrate Eastern philosophy in their thinking). But there was a split between the empiricist and intuitionist view of knowledge among them. Peirce through his pragmaticist semiotics suggested a way to unite these two hostile epistemologies. Peirce attempts a new way of answering...... Kant’s basic question in the Critique of Pure Reason: What can we know? and What may we hope? Peirce saw as his primary task to develop a comprehensive metaphysical and epistemological system in which a theory of categories was defined in a completely new way....

  1. PONDEROSA-C/S: client–server based software package for automated protein 3D structure determination

    Lee, Woonghee; Stark, Jaime L.; Markley, John L.


    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727–1728. doi:10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nucle...

  2. Radiolabeling and biotinylation of internalizing monoclonal antibody chimeric BR96: Potential use of extracorporeal immunoadsorption with enhanced tumor radioactivity retention of Iodine, Indium and Rhenium

    Chen, JianQing


    In this thesis, methodology of radiolabeling and simultaneous biotinylation for internalizing monoclonal antibody chimeric BR96 have been investigated by using three element groups of potential therapeutic radionuclides iodine, indium and rhenium, and their different labeling methods. The biodistribution and kinetics of biotinylated and radiolabeled chiBR96 have been studied in colon carcinoma isografted rats. The potential use of ECIA, based on the biotin-avidin concept, has been evaluated and compared with the approach of avidin `chase` in the same animal tumor model with respect to an enhancement of tumor-to-normal tissue (T/N) activity ratio. 131 refs.

  3. Synthesis, characterization, photoluminescence and electroluminescence properties of new 1,3,4-oxadiazole-containing rhenium(Ⅰ)complex Re(CO)3(Bphen)(PTOP)


    A new 1,3,4-oxadiazole-contanining rhenium(Ⅰ) complex, with the formula [Re(CO)3(Bphen)(PTOP)], (Bphen = bathophenardine, PTOP = 4-(5-p-tolyl-1, 3, 4-oxadiazd-2-yl) pyridine), is synthesized and characterized by elemental analysis, IR, 1H NMR,UV-vis and luminescence spectroscopy. The double-layer electroluminescence devices based on the Re(Ⅰ) complex have been fabricated by spin-coating technique. The turn-on voltage, maximum efficiency, and brightness for green emission obtained from the devices are 9 V, 2.1 cd/A and 165 cd/m2, respectively.

  4. Lump Kinetic Analysis of Syngas Composition Effect on Fischer-Tropsch Synthesis over Cobalt and Cobalt-Rhenium Alumina Supported Catalyst

    Dewi Tristantini


    Received: 10th November 2015; Revised: 10th February 2016; Accepted: 16th February 2016 How to Cite: Tristantini, D., Suwignjo, R.K. (2016. Lump Kinetic Analysis of Syngas Composition Effect on Fischer-Tropsch Synthesis over Cobalt and Cobalt-Rhenium Alumina Supported Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 84-92. (doi:10.9767/bcrec.11.1.424.84-92 Permalink/DOI:

  5. Photodetectors: Broad Detection Range Rhenium Diselenide Photodetector Enhanced by (3-Aminopropyl)Triethoxysilane and Triphenylphosphine Treatment (Adv. Mater. 31/2016).

    Jo, Seo-Hyeon; Park, Hyung-Youl; Kang, Dong-Ho; Shim, Jaewoo; Jeon, Jaeho; Choi, Seunghyuk; Kim, Minwoo; Park, Yongkook; Lee, Jaehyeong; Song, Young Jae; Lee, Sungjoo; Park, Jin-Hong


    The effects of triphenylphosphine (PPh3 ) and (3-amino-propyl)triethoxysilane (APTES) on a rhenium diselenide (ReSe2 ) photodetector are systematically studied by J.-H. Park and co-workers on page 6711 in comparison with a conventional MoS2 device. A very high performance ReSe2 photodetector is demonstrated, which has a broad photodetection range, high photoresponsivity (1.18 × 10(6) A W(-1) ), and fast photoswitching speed (rising/decaying time: 58/263 ms). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Endovascular brachytherapy (EVBT) with rhenium-188 for restenosis prophylaxis after angioplasty of infrainguinal lesions. Early experience; Endovaskulaere Brachytherapie (EVBT) mit Rhenium-188 zur Restenoseprophylaxe nach Angioplastie infrainguinaler Laesionen. Erste Erfahrungen

    Leissner, G.G.; Winterstein, A.; Bohndorf, K.; Wohlgemuth, W.A. [Klinikum Augsburg (Germany). Klinik fuer Diagnostische Radiologie und Neuroradiologie; Wengenmair, H. [Klinikum Augsburg (Germany). Medizinische Physik und Strahlenschutz; Sciuk, J. [Klinikum Augsburg (Germany). Klinik fuer Nuklearmedizin; Woelfle, K.D. [Klinikum Augsburg (Germany). Klinik fuer Gefaesschirurgie; Weinrich, K. [Klinikum Augsburg (Germany). II. Medizinische Klinik, Angiologie


    Purpose: Restenosis remains a major problem in percutaneous transluminal angioplasty (PTA) of peripheral arteries. The aim of this feasibility study was to evaluate the technical feasibility and safety of a new endovascular brachytherapy (EVBT) device with Rhenium-188 in restenosis prophylaxis of infrainguinal arteries. Materials and Methods: From March 2006 to April 2009, 52 patients with 71 infrainguinal arterial lesions were treated with Re-188 to prevent restenosis after PTA. 40 patients with 53 lesions (24 de-novo lesions and 29 restenoses) were reexamined (clinic, color-coded duplex ultrasound) after a mean follow-up period of 12.7 months (2.6 to 25.1 months). The liquid beta-emitter Re-188 was introduced to the target lesion via an EVBT certified PTA balloon and a tungsten applicator. After the calculated irradiation time, Re-188 was aspirated back into the tungsten applicator. A dose of 13 Gy was applied at a depth of 2 mm into the vessel wall. Results: After a mean follow-up of 12.7 months, the overall restenosis rate after Re-PTA was 15.1 % (8/53 lesions). The restenosis rate for de-novo lesions was 20.8 % (5/24) and 10.3 % for restenoses (3/29). In 4 patients reintervention was necessary (3 PTAs and 2 major amputations). No periprocedural complications were observed. No elevated radiation dose for the patient or the interventionalist was measured. Conclusion: EVBT with a Re-188 filled balloon catheter was technically feasible and safe after PTA of infrainguinal arterial lesions with restenosis rates lower than expected compared to published results. Treatment of restenoses seems to be more effective than de-novo lesions. (orig.)

  7. Dissimilar behavior of technetium and rhenium in borosilicatewaste glass as determined by X-ray absorption spectroscopy

    Lukens, Wayne W.; McKeown, David A.; Buechele, Andrew C.; Muller,Isabelle S.; Shuh, David K.; Pegg, Ian L.


    Technetium-99 is an abundant, long-lived (t1/2 = 213,000 yr)fission product that creates challenges for the safe, long-term disposalof nuclear waste. While 99Tc receives attention largely due to its highenvironmental mobility, it also causes problems during its incorporationinto nuclear waste glass due to the volatility of Tc(VII) compounds. Thisvolatility decreases the amount of 99Tc stabilized in the waste glass andcauses contamination of the waste glass melter and off-gas system. Theapproach to decrease the volatility of 99Tc that has received the mostattention is reduction of the volatile Tc(VII) species to less volatileTc(IV) species in the glass melt. On engineering scale experiments,rhenium is often used as a non-radioactive surrogate for 99Tc to avoidthe radioactive contamination problems caused by volatile 99Tc compounds.However, Re(VII) is more stable towards reduction than Tc(VII), so morereducing conditions would be required in the glass melt to produceRe(IV). To better understand the redox behavior of Tc and Re in nuclearwaste glass, a series of glasses were prepared under different redoxconditions. The speciation of Tc and Re in the resulting glasses wasdetermined by X-ray absorption fine structure spectroscopy. Surprisingly,Re and Tc do not behave similarly in the glass melt. Although Tc(0),Tc(IV), and Tc(VII) were observed in these samples, only Re(0) andRe(VII) were found. In no case was Re(IV) (or Re(VI))observed.

  8. Ultra-small rhenium nanoparticles immobilized on DNA scaffolds: An excellent material for surface enhanced Raman scattering and catalysis studies.

    Anantharaj, S; Sakthikumar, K; Elangovan, Ayyapan; Ravi, G; Karthik, T; Kundu, Subrata


    Highly Sensitive and ultra-small Rhenium (Re) metal nanoparticles (NPs) were successfully stabilized in water by the staging and fencing action of the versatile biomolecule DNA that resulted in two distinct aggregated chain-like morphologies with average grain sizes of 1.1±0.1nm and 0.7±0.1nm for the very first time within a minute of reaction time. Re NPs are formed by the borohydride reduction of ammonium perrhenate (NH4ReO4) in the presence of DNA at room temperature (RT) under stirring. The morphologies were controlled by carefully monitoring the molar ratio of NH4ReO4 and DNA. The synthesized material was employed in two potential applications: as a substrate for surface enhanced Raman scattering (SERS) studies and as a catalyst for the reduction of aromatic nitro compounds. SERS study was carried out by taking methylene blue (MB) as the probe and the highest SERS enhancement factor (EF) of 2.07×10(7) was found for the aggregated chain-like having average grain size of 0.7±0.1nm. Catalytic reduction of 4-nitro phenol (4-NP), 2-nitro phenol (2-NP) and 4-nitroaniline (4-NA) with a rate constant value of 6×10(-2)min(-1), 33.83×10(-2)min(-1) and 37.4×10(-2)min(-1) have testified the excellent catalytic performance of our Re NPs immobilized on DNA. The overall study have revealed the capability of DNA in stabilizing the highly reactive Re metal at nanoscale and made them applicable in practice. The present route can also be extended to prepare one dimensional (1-D), self-assembled NPs of other reactive metals, mixed metals or even metal oxides for specific applications in water based solutions.

  9. pH luminescence switching, dihydrogen phosphate sensing, and cellular uptake of a heterobimetallic ruthenium(II)-rhenium(I) complex.

    Zheng, Ze-Bao; Wu, Yong-Quan; Wang, Ke-Zhi; Li, Fuyou


    A new heterobimetallic ruthenium(II)-rhenium(I) complex of [Ru(bpy)2(HL)Re(CO)3Cl](ClO4)2·6H2O (RuHLRe) {bpy = 2,2'-bipyridine and HL = 2-(4-(2,6-di(pyridin-2-yl)pyridin-4-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline} was synthesised and characterised by elemental analysis, proton nuclear magnetic resonance spectroscopy, and mass spectrometry. The ground- and excited-state acid-base properties of RuHLRe were studied using UV-Vis absorption spectrophotometric and spectrofluorimetric titrations in a 100 : 1 (v/v) Britton-Robinson buffer-CH3CN solution combined with luminescence lifetime measurements. The complex exhibited two-step separate protonation-deprotonation processes in both the ground and excited states. The complex acted as pH-induced "off-on-off" luminescence switches (I(on)/I(off) = 31.0 and 14.6), with one of the switching actions being driven by pH variations over the physiological pH range (5.3-8.0). Importantly, cellular imaging and cytotoxicity experiments demonstrated that RuHLRe rapidly and selectively illuminated the membrane of HeLa cells over fixed cells and exhibited reduced cytotoxicity at the imaging concentration compared to the Re(I)-free parent Ru(II) complex. In addition, RuHLRe acted as an efficient "turn on" emission sensor for H2PO4(-) and "turn off" emission sensor for F(-) and OAc(-).

  10. Theoretical studies on the electronic structures and photoelectron spectra of tri-rhenium oxide clusters: Re3On- and Re3On (n = 1-6)

    Zhou, Qi; Gong, Wei-Chao; Xie, Lu; Zheng, Cun-Gong; Zhang, Wei; Wang, Bin; Zhang, Yong-Fan; Huang, Xin


    Density functional theory (DFT) calculations are performed to study the structural and electronic properties of tri-rhenium oxide clusters Re3On-/0 (n = 1-6). Generalized Koopmans' theorem is applied to predict the vertical detachment energies (VDEs) and simulate the photoelectron spectra (PES). Theoretical calculations at the B3LYP level are carried out to search for the global minima for both the anions and the neutrals. For the anions, the first two O atoms prefer the same corner position of a Re3 triangle. Whereas, Re3O3- possesses a C2v symmetry with one bridging and two terminal O atoms. The next three O atoms (n = 4-6) are adding sequentially on the basis of Re3O3- motif, i.e., adding one terminal O atom for Re3O4-, one terminal and one bridging O atoms for Re3O5-, and one terminal and two bridging O atoms for Re3O6-, respectively. Their corresponding neutral species are similar to the anions in geometry except Re3O4 and Re3O5. Molecular orbital analyses are employed to investigate the chemical bonding and structural evolution in these tri-rhenium oxide clusters.

  11. Spectral interferences in the determination of rhenium in molybdenum and copper concentrates by inductively coupled plasma optical emission spectrometry (ICP-OES)

    Karadjov, Metody; Velitchkova, Nikolaya; Veleva, Olga; Velichkov, Serafim; Markov, Pavel; Daskalova, Nonka


    This paper deals with spectral interferences of complex matrix containing Mo, Al, Ti, Fe, Mg, Ca and Cu in the determination of rhenium in molybdenum and copper concentrates by inductively coupled plasma optical emission spectrometry (ICP-OES). By radial viewing 40.68 MHz ICP equipped with a high resolution spectrometer (spectral bandwidth = 5 pm) the hyperfine structure (HFS) of the most prominent lines of rhenium (Re II 197.248 nm, Re II 221.426 nm and Re II 227.525 nm) was registered. The HFS components under high resolution conditions were used as separate prominent line in order to circumvent spectral interferences. The Q-concept was applied for quantification of spectral interferences. The quantitative databases for the type and the magnitude of the spectral interferences in the presence of above mentioned matrix constituents were obtained by using a radial viewing 40.68 MHz ICP with high resolution and an axial viewing 27.12 MHz ICP with middle resolution. The data for the both ICP-OES systems were collected chiefly with a view to spectrochemical analysis for comparing the magnitude of line and wing (background) spectral interference and the true detection limits with spectroscopic apparatus with different spectral resolution. The sample pretreatment methods by sintering with magnesium oxide and oxidizing agents as well as a microwave acid digestion were applied. The feasibility, accuracy and precision of the analytical results were experimentally demonstrated by certified reference materials.

  12. Formation of sulfido ciobium complexes through C-S bond activation

    Azevedo Nélio Pires


    Full Text Available Upon reacting (eta5-C5H52NbCl2, eta5-C5H5 = Cp, and (Ph3Sn(SPh, in THF, (eta5-C5H52Nb(Cl(mu-SSn(Ph3(Cl, 1, and (eta5-C5H52Nb(SCl, 2, were obtained. Complexes 1 and 2 were characterized by IR, ¹H-NMR, 13C-NMR, Mössbauer spectroscopies, elemental analysis as well as by atomic absorption. Hydrolysis of 1 yielded the mu-oxo species, (eta5-C5H52Nb(Cl(mu-OSn(Ph3Cl, 3, which was characterized by IR, ¹H-NMR, 13C-NMR and Mössbauer spectroscopies, elemental analysis, atomic absorption as well as by X-ray crystallography. It crystallizes in the space group Pca2(1 with a = 17.282(3, b = 18.122(4, c = 17.3269(2, V = 5426.2(16 ų, and Z = 8. Additional studies indicated that the complexes were formed as a result of the nucleophilic displacement of the niobium-chloride bond by the thiolate ligand followed by a C-S bond cleavage. The cleavage occurs with an excess of the thiolate compound equal to or greater than 2:1.

  13. Jesus in Narnia. Narrative Katechese im Werk von C. S. Lewis

    Jadranka Garmaz


    Full Text Available This paper seeks to explore the narrative catechesis and elements of religious pedagogy in C. S. Lewis’ “The Chronicles of Narnia” and to critically ponder on the following questions: To what extent is the message of faith conveyed to the reader by Lewis’ story-telling? In which way is a narrative approach to theology and catechesis articulated and realised? Why is the narrative catechesis useful and what is its role in the context of the overall mission of the Church i.e. the preaching of the Gospel? In order to provide answers to these questions the first part of this paper outlines a Christian allegory of the Narnian stories. The second part deals with the formalistic approach as using allegory, allusion, and symbolism to interpret Lewis’ narrative. The third part outlines the need for a critical awareness and the role of theological narrative in flourishing humanity and human wholeness. The concluding section presents an overall assessment of Lewis’s Christian fantasy and its faith-shaping impact.

  14. Ransom, Religion, and Red Giants: C.S. Lewis and Fred Hoyle

    Larsen, Kristine


    Famed fantasy writer C.S. Lewis (1898-1963) was known to friends as a well-read astronomy aficionado. However, this medieval scholar and Christian apologist embraced a pre-Copernican universe (with its astrological overtones) in his Chronicles of Narnia series and defended the beauty and relevance of the geocentric model in his final academic work, "The Discarded Image". In the "Ransom Trilogy” ("Out of the Silent Planet", "Perelandra", and "That Hideous Strength") philologist Ransom (loosely based on Lewis's close friend J.R.R. Tolkien) travels to Lewis's visions of Mars and Venus, where he interacts with intelligent extraterrestrials, battles with evil scientists, and aids in the continuation of extraterrestrial Christian values. In the final book, Ransom is joined by a handful of colleagues in open warfare against the satanic N.I.C.E. (National Institute for Coordinated Experiments). Geneticist and evolutionary biologist J.B.S. Haldane criticized Lewis for his scientifically inaccurate descriptions of the planets, and his disdain for the scientific establishment. Lewis responded to the criticism in essays of his own. Another of Lewis's favorite scientific targets was atheist Fred Hoyle, whom he openly criticized for anti-Christian statements in Hoyle's BBC radio series. Writer and Lewis friend Dorothy L. Sayers voiced her own criticism of Hoyle. In a letter, Lewis dismissed Hoyle as "not a great philosopher (and none of my scientific colleagues think much of him as a scientist.” Given Lewis's lack of respect for Hoyle, and use of creative license in describing the planets, and the flat-earth, "geocentric” Narnia, it is surprising that Lewis very carefully includes an astronomically correct description of red giants in two novels in the Narnia series ("The Magician's Nephew" and "The Last Battle"). This inclusion is even more curious given that Fred Hoyle is well-known as one of the pioneers in the field of stellar death and the properties of red giants.

  15. Evaluation of technetium-99m/rhenium labelled nucleoside analogues as potential radiotracers in oncology[Dissertation 17173

    Desbouis, D


    }M). This compound also exhibited a mixed inhibition of the hTK1 with K{sub ic} = 73 {+-} 20 {mu}M. When tested in vitro for cell uptake in transfected cancer cells this technetium thymidine complex revealed a low internalisation of 0.03 {+-} 0.01%ID/(mg/mL). Under the same conditions the [{sup 3}H]thymidine exhibited an uptake of 1.50 {+-} 0.02%lD/(mg/mL). In order to gain potency and selectivity for HSV1-TK, the corresponding 5'-carboxamide 5-ethyl-2', 5'-dideoxyuridine was synthesized. The synthesis of the ligand was performed in seven steps from 2'-deoxyuridine. This ligand was then successfully labelled with the fac-M(CO){sub 3}-core (M = {sup 99m}Tc, Re). The rhenium complex was found to be a selective competitive inhibitor of HSV1-TK (K{sub i} = 4.56 {+-} 0.11 {mu}M). Although the cellular uptake of the technetium 2'-deoxyurine complex (0.10 {+-} 0.01%ID/(mg/mL)) was better than its corresponding technetium thymidine complex, it is still very low compared to thymidine uptake. The second aspect of this work was to develop nucleoside derivatives labelled with technetium-99m/rhenium tricarbonyl core capable of acting as substrates for human cytosolic thymidine kinase (hTKl). hTKl is a target of choice to evaluate cell proliferation due to its overexpression in a variety of cancer cells. [{sup 18}F]Fluorothymidine [{sup 18}F]FLT), which acts as a hTKl substrate, has emerged as a very efficient PET tracer for the monitoring of cell proliferation. Our aim was to develop a SPET tracer with the same mode of action as [{sup 18}F]FLT. We prepared a set of technetium-99m/rhenium complexes of N3 thymidine derivatives with different overall charges (+1, 0 and -1) and variable spacer lengths. The complexes with different overall charges had the same spacer length between chelating system and thymidine moiety (two carbons spacer) while the complexes with different spacer lengths (2, 3, 5 and 10) were all neutral. These compounds were tested for their

  16. $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ As the Lightest $c\\bar c s \\bar s$ State

    Lebed, Richard F


    The state $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ has recently been demoted by the Particle Data Group from its previous status as the conventional $c\\bar c$ $2 {}^3P_0$ state, largely due to the absence of expected $D\\bar D$ decays. We propose that $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ is actually the lightest $c\\bar c s \\bar s$ state, and calculate the spectrum of such states using the diquark model, identifying many of the observed charmoniumlike states that lack open-charm decay modes as $c\\bar c s \\bar s$. Among other results, we argue that $Y(4140)$ is a $J^{PC} = 1^{++}$ $c\\bar c s \\bar s$ state that has been not been seen in two-photon fusion largely as a consequence of the Landau-Yang theorem.

  17. Rhenium - osmium heterogeneity of enriched mantle basalts explained by composition and behaviour of mantle-derived sulfides

    Harvey, J.; Dale, C. W.; Gannoun, A.; Burton, K. W.


    Analyses of enriched mantle (EM) -basalts, using lithophile element-based isotope systems have long provided evidence for discrete, but variable mantle reservoirs [1]. Upon partial melting, the isotopic fingerprint of each reservoir is imparted upon the partial melt produced. However, recent work involving the Re-Os isotope systematics of EM-basalts [2] suggests that it may not be so simple to delimit these previously well defined mantle reservoirs; the “mantle zoo” [3] may contain more reservoirs than previously envisaged. However, a simple model, with varying contributions from two populations of compositionally distinct mantle sulfides can readily account for the observed heterogeneities in Re-Os isotope systematics of such basalts without additional mantle reservoirs. Rhenium-osmium elemental and isotopic analyses of individual sulfide grains separated from spinel lherzolites from Kilbourne Hole, NM, USA demonstrate that two discrete populations of mantle sulfide exist in terms of both Re-Os systematics and textural relationship with co-existing silicates. One population, with a rounded morphology, is preserved in silicate grains and typically possesses high [Os], low [Re] with unradiogenic, typically sub-chondritic, 187Os/188Os attributable to long term isolation in a low-Re environment. By contrast, irregular-shaped sulfides, preserved along silicate grain boundaries, possess low [Os], higher [Re] and a wider range of, but generally supra-chondritic, 187Os/188Os ([Os] typically ≤ 1-2 ppm, 187Os/188Os ≤ 0.3729; this study). This population is thought to represent metasomatic sulfide (e.g. [4,5]). Uncontaminated silicate phases contain negligible Os (mobilized and incorporated into the melt, adding their radiogenic 187Os/188Os signature. Only when sulfides armored within silicates are exposed to the melt through continued partial melting will enclosed sulfides add their high [Os] and unradiogenic 187Os/188Os to the aggregate melt. Platinum-group element

  18. Doxycycline reduces plasma VEGF-C/sVEGFR-3 and improves pathology in lymphatic filariasis.

    Debrah, Alexander Yaw; Mand, Sabine; Specht, Sabine; Marfo-Debrekyei, Yeboah; Batsa, Linda; Pfarr, Kenneth; Larbi, John; Lawson, Bernard; Taylor, Mark; Adjei, Ohene; Hoerauf, Achim


    lymphedema in the doxycycline-treated patients being significantly lower compared to placebo patients 12 mo after treatment. The reduction in the stages manifested as better skin texture, a reduction of deep folds, and fewer deep skin folds. In conclusion, a 6-wk regimen of antifilarial treatment with doxycycline against W. bancrofti showed a strong macrofilaricidal activity and reduction in plasma levels of VEGF-C/sVEGFR-3, the latter being associated with amelioration of supratesticular dilated lymphatic vessels and with an improvement of pathology in lymphatic filariasis patients.

  19. Doxycycline reduces plasma VEGF-C/sVEGFR-3 and improves pathology in lymphatic filariasis.

    Alexander Yaw Debrah


    the mean stage of lymphedema in the doxycycline-treated patients being significantly lower compared to placebo patients 12 mo after treatment. The reduction in the stages manifested as better skin texture, a reduction of deep folds, and fewer deep skin folds. In conclusion, a 6-wk regimen of antifilarial treatment with doxycycline against W. bancrofti showed a strong macrofilaricidal activity and reduction in plasma levels of VEGF-C/sVEGFR-3, the latter being associated with amelioration of supratesticular dilated lymphatic vessels and with an improvement of pathology in lymphatic filariasis patients.

  20. Mechanistic studies of a novel C-S lyase in ergothioneine biosynthesis: the involvement of a sulfenic acid intermediate.

    Song, Heng; Hu, Wen; Naowarojna, Nathchar; Her, Ampon Sae; Wang, Shu; Desai, Rushil; Qin, Li; Chen, Xiaoping; Liu, Pinghua


    Ergothioneine is a histidine thio-derivative isolated in 1909. In ergothioneine biosynthesis, the combination of a mononuclear non-heme iron enzyme catalyzed oxidative C-S bond formation reaction and a PLP-mediated C-S lyase (EgtE) reaction results in a net sulfur transfer from cysteine to histidine side-chain. This demonstrates a new sulfur transfer strategy in the biosynthesis of sulfur-containing natural products. Due to difficulties associated with the overexpression of Mycobacterium smegmatis EgtE protein, the proposed EgtE functionality remained to be verified biochemically. In this study, we have successfully overexpressed and purified M. smegmatis EgtE enzyme and evaluated its activities under different in vitro conditions: C-S lyase reaction using either thioether or sulfoxide as a substrate in the presence or absence of reductants. Results from our biochemical characterizations support the assignment of sulfoxide 4 as the native EgtE substrate and the involvement of a sulfenic acid intermediate in the ergothioneine C-S lyase reaction.

  1. Thiourea in the Construction of C-S Bonds as Part of an Undergraduate Organic Chemistry Laboratory Course

    Lu, Guo-ping; Chen, Fei; Cai, Chun


    The nucleophilic aromatic substitution reaction and thia-Michael addition using thiourea as an odorless, cheap, and easy-to-handle sulfur source in water are described, which can be used to teach upper-division undergraduates the role of thiourea in the formation of C-S bonds and the principles of green chemistry. The use of a cheap, nontoxic…

  2. Protein C/S ratio, an accurate and simple tool to identify carriers of a protein C gene mutation

    Libourel, EJ; Meinardi, [No Value; de Kam, PJ; Ruiters, MHJ; van der Meer, J; van der Schaaf, W; Veenstra, R.

    Hereditary protein C deficiency is demonstrated by lowered protein C plasma levels in a patient and at least one first-degree relative. This approach is insufficient in some cases owing to overlapping protein C levels in carriers and non-carriers of a protein C gene mutation. The protein C/S ratio

  3. Computer Simulation of the E.C.C.S. Buckling Curve using a Monte-Carlo Method

    Strating, J.; Vos, H.


    The application of a Monte-Carlo simulation procedure to obtain the distribution function of the maximum load of a hinged column with imperfections is discussed. Buckling tests carried out by the E.C.C.S. on IPE 160 sections have been simulated. Information concerning the column variables is obtaine

  4. Final Evaluation Report for the C.S. 211 Bilingual Gifted and Talented Program 1978-1979.

    Brumberg, Stephan F.; Toledo, Victor

    This report provides a program description and evaluation findings of a bilingual program for gifted and talented children conducted at C.S. 211, an elementary school serving black and Hispanic children in an economically deprived area of the Bronx, New York. The program's goals, which included above grade level reading and mathematics performance…

  5. Silver-mediated decarboxylative C-S cross-coupling of aliphatic carboxylic acids under mild conditions.

    Wang, Peng-Fei; Wang, Xiao-Qing; Dai, Jian-Jun; Feng, Yi-Si; Xu, Hua-Jian


    A silver-mediated decarboxylative C-S cross-coupling reaction of aliphatic carboxylic acid is described. This reaction occurs smoothly under mild conditions and shows good tolerance of functional groups. It provides an alternative approach for the synthesis of alkyl aryl sulfides.

  6. The uptake of Cs, Cl, I, Co, U and Pu by C-S-H, portlandite and ettringite

    Le Callonnec, C.; Richet, C.; Ayache, R


    The aim of this work is to study the retention of Pu, Cs, Cl, U, Co and I onto the three phases of a cement paste: calcium silicate hydrates or C-S-H (Ca/Si=1.65), portlandite (Ca(OH){sub 2}) and ettringite (Ca{sub 6}Al{sub 2}S{sub 3}O{sub 21}.32H{sub 2}O). C-S-H of Ca/Si molar ratio of 1.65 and ettringite were prepared in suspension, while portlandite was provided by an industrial laboratory. The sorptive power for each ion was determined by a batch model at 20 degrees Celsius. The uptake of ions onto the phases has been obtained by introducing a very small volume of radioactive Cs, Co, Cl, I, U and Pu solution in each batch. Aliquots of solution were periodically removed for analysis. The results show that there are two kinds of ions whatever the solid phase: those which are poorly sorbed: Cs, Cl, I and Co, U and Pu which are strongly sorbed (by a factor 100 to 10000). Elsewhere, the comparison between the sorptive power of each phase reveals that C-S-H develops a significant sorption potential for pluri-valent ions (Pu, U, Co) as well as for Cl. The retention capacity of portlandite mainly towards pluri-valent cations is one or two orders of magnitude weaker than C-S-H capacity. Ettringite only plays a sorptive role relatively to Cs. However, iodine does not have a strong affinity for any solid at all. The data allow us to calculate a global sorption coefficient Kd of the cement paste for each ion. Assuming that the proportion of C-S-H, portlandite, ettringite is respectively 65%, 15% and 5% in a Portland cement, the global sorption coefficient is in good agreement with literature regarding on U, Cs, I and Cl. Cementitious materials appear to be an interesting chemical barrier that can limit the diffusion of pluri-valent cations. As C-S-H represent from 60% to 75% of the cement paste, this study leads to underline that C-S-H is mainly responsible for the retention capacity of cementitious materials specially towards U, Pu, Co, Cl although its sorption power is

  7. Crystal structure of cis-bis-(μ-β-alanine-κ(2) O:O')bis[tri-chlorido-rhenium(III)](Re-Re) sesquihydrate.

    Golichenko, Alexander A; Domasevitch, Konstantin V; Kytova, Dina E; Shtemenko, Alexander V


    The structure of the title compound, [Re2Cl6(C3H7NO2)2]·1.5H2O, comprises a dinuclear complex cation [Re-Re = 2.2494 (3) Å] involving cis-oriented double carboxyl-ate bridges, four equatorial chloride ions and two weakly bonded chloride ligands in the axial positions at the two rhenium(III) atoms. In the crystal, two complex mol-ecules and two water mol-ecules constitute hydrogen-bonded dimers, while an extensive hydrogen-bonding network involving the groups of the zwitterionic ligand is important for generation of the framework. An additional partially occupied water molecule is disordered over two sets of sites about a symmetry centre with a site-occupancy ratio of 0.3:0.2.

  8. A Theoretical Study of the Binding of [Re6Se8(OH2(H2O4] Rhenium Clusters to DNA Purine Base Guanine

    Leonor Alvarado-Soto


    Full Text Available Hexanuclear rhenium complexes are promising candidates for use as antitumor drugs. However, to date, there has been no investigation into the nature of their binding to DNA. In this study, density functional theory (DFT was used to examine the binding of [Re6Se8(OH2(H2O4] to the DNA purine base guanine. The geometrical structures of cluster-guanine adducts in water were modeled at the zero order regular approximation (ZORA-PW91 level. Calculating the bond energies allowed us to compare the cis and trans forms of the cluster, and a possible manners of interaction between [Re6Se8(OH2(H2O3] clusters and DNA was obtained and explained.

  9. PONDEROSA-C/S: client-server based software package for automated protein 3D structure determination.

    Lee, Woonghee; Stark, Jaime L; Markley, John L


    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727-1728. doi: 10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nuclear Overhauser data sets ((13)C- and/or (15)N-NOESY). The output is a set of assigned NOEs and 3D structural models for the protein. Ponderosa Analyzer supports the visualization, validation, and refinement of the results from Ponderosa Server. These tools enable semi-automated NMR-based structure determination of proteins in a rapid and robust fashion. We present examples showing the use of PONDEROSA-C/S in solving structures of four proteins: two that enable comparison with the original PONDEROSA package, and two from the Critical Assessment of automated Structure Determination by NMR (Rosato et al. in Nat Methods 6:625-626. doi: 10.1038/nmeth0909-625 , 2009) competition. The software package can be downloaded freely in binary format from Registered users of the National Magnetic Resonance Facility at Madison can submit jobs to the PONDEROSA-C/S server at, where instructions, tutorials, and instructions can be found. Structures are normally returned within 1-2 days.

  10. Use of the Oak Ridge National Laboratory tungsten-188/rhenium-188 generator for preparation of the rhenium-188 HDD/lipiodol complex for trans-arterial liver cancer therapy

    Jeong, J M [Seoul National University; Knapp Jr, Russ F [ORNL


    This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ({sup 188}W)/rhenium-188 ({sup 188}Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the {sup 188}Re-perrhenate bolus and preparation of {sup 188}Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The {sup 188}W/{sup 188}Re generator has a long useful shelf-life of several months and is a convenient on-site {sup 188}Re production system. {sup 188}Re has excellent therapeutic and imaging properties (T{sub 1/2} 16.9 hours; E{sub {beta}max} 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of {sup 188}Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of {sup 188}Re, several {sup 188}Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. {sup 188}Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of {sup 188}Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) {sup 188}W/{sup 188}Re generators. The handling of such high levels of {sup 188}Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (i.e., 'As Low As Reasonably Achievable') principles must be followed. The ORNL generator provides consistently high {sup 188}Re yields (>75%) and low {sup 188}W parent breakthrough (<10{sup -3}%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require


    The solid state phase equilibria of the metal-rich regions of the Titanium-Molybdenum-Carbon and Titanium-Niobium-Carbon systems with up to 12 At...Rhenium and 10 At.% Aluminum additions, respectively, have been determined on hot pressed, heat treated, and in part arc melted alloys. The phase ... equilibria in the metal-rich regions, with these additions, is practically unchanged over that of the ternary Titanium-Molybdenum-Carbon and Titanium

  12. Using of hypnum cupressiforme as a bioaccumulator of heavy metals and {sup 1}37{sup C}s; Utilizzo di Hypnum cupressiforme come bioaccumulatore di metalli pesanti e {sup 1}37{sup C}s

    Larcher, S.; Roella, V.; Biccai, G. [ANPA Lombardia, Varese (Italy)


    The aim of this research, which was carried out from July 1997 to June 1998, was to evaluate the deposition of some heavy metals (Cu, Pb, Zn, Mn, Fe) in the city of Varese, using the moss Hypnum cupressiforme as a bioaccumulator. Therefore some mosses were picked up in an unpolluted area to prepare eight biological stations placed in the city centre. This research and the statistic analysis applied to the results made it possible to find out the most metal-polluted areas in the city and to verify the influence of the traffic in the stations close to the street. Hypnum cupressiforme was also used as a bioaccumulator of the artificial radionuclide {sup 1}37{sup C}s in order to see if traces of the nuclear incident in Chernobyl (April 1986) were detectable in indigenous mosses in the northern part of Varese province. The results have shown that the {sup 1}37{sup C}s, when present, has low concentration and therefore the remaining radioactivity is not dangerous any more. [Italian] La presente ricerca, effettuata nel periodo luglio 1997-giugno 1998, ha avuto lo scopo di valutare la deposizione di alcuni metalli pesanti (Cu, Pb, Zn, Mn, Fe) nella citta' di Varese, impiegando il muschio Hypnum cupressiforme come organismo accumulatore. Sono state pertanto allestite otto stazioni biologiche distribuite nel centro cittadino utilizzando muschio raccolto in una zona supposta poco inquinata. L'indagine svolta e l'analisi statistica applicata ai dati ottenuti hanno permesso di individuare le aree della citta' maggiormente soggette alla contaminazione da metalli e di verificare l'influenza dell'intensita' del traffico nelle stazioni poste in vicinanza di strade. Hypnum cupressiforme e' stato anche impiegato come bioaccumulatore del radionuclide artificiale {sup 1}37{sup C}s, per verificare se fossero ancora rilevabili tracce dell'incidente nucleare di Chernobyl (aprile 1986) in muschi indigeni cresciuti nella provincia a Nord di

  13. Facile C-S, S-H, and S-S bond cleavage using a nickel(0) NHC complex.

    Schaub, Thomas; Backes, Marc; Plietzsch, Oliver; Radius, Udo


    [Ni2(iPr2Im)4(COD)] 1 (iPr2Im = 1,3-di(isopropyl)-imidazol-2-ylidene) reacts at room temperature with the thioethers methyl para-tolyl sulfide, ethyl phenyl sulfide, benzothiophene and dibenzothiophene to afford the C-S bond cleavage products [Ni(iPr2Im)2(4-CH3-C6H4)(SMe)] 2, [Ni(iPr2Im)2(C6H5)(SEt)] 3, [Ni(iPr2Im)2(1,8-benzothiophenylato)] 4 and [Ni(iPr2Im)2(C,S-dibenzothiophenylato)] 5. In contrast to the reaction of thioethers or sulfoxides (reported earlier), no C-S bond cleavage was observed for the reaction of 1 with the sulfones bezothiophene-1,1-dioxide and methyl phenyl sulfone. In those cases the stable compounds [Ni(iPr2Im)2(eta2-2,3-benzothiophene-1,1-dioxide)] 6 and [Ni(iPr2Im)2(eta2-MeSO2C6H5)] 7 with a eta2-coordinated sulfone ligand have been isolated. Compound 6 has been structurally characterized. S-H bond cleavage was observed using 2-methyl-2-propanthiol to afford [Ni(iPr2Im)2(H)(StBu)] 8. The reaction of 1 with disulfides led to the dithiolato complexes [Ni(iPr2Im)2(SR)2] (R = tBu 9, Me 10, Ph 11) by S-S bond scission.

  14. Synthesis, Crystal Structure, and Magnetic Properties of Tetraphenylarsonium Tetrachloro(oxalato)rhenate(IV) and Bis(2,2'-bipyridine)tetrachloro(&mgr;-oxalato)copper(II)rhenium(IV).

    Chiozzone, Raúl; González, Ricardo; Kremer, Carlos; De Munno, Giovanni; Cano, Joan; Lloret, Francesc; Julve, Miguel; Faus, Juan


    Two new rhenium(IV) compounds of formula (AsPh(4))(2)[ReCl(4)(ox)] (1) and [ReCl(4)(&mgr;-ox)Cu(bipy)(2)] (2) (AsPh(4) = tetraphenylarsonium cation, ox = oxalate anion, and bipy = 2,2'-bipyridine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 and 2 crystallize in the monoclinic system, space groups P2(1)/c and P2(1)/n, respectively, with a = 22.250(5) Å, b = 11.245(3) Å, c = 19.089(4) Å, beta = 96.59(2) degrees, and Z = 4 for 1 and a = 9.421(2) Å, b = 16.909(4) Å, c = 16.179(4) Å, beta = 93.97(2) degrees, and Z = 4 for 2. The structure of 1 is made up of [ReCl(4)(ox)](2)(-) anions and AsPh(4)(+) cations held united by electrostatic forces. Rhenium(IV) is hexacoordinate, with two oxygens of a chelating ox and four chlorine atoms building a distorted octahedron around the metal atom. There is no contact between the [ReCl(4)(ox)](2)(-) anions, the shortest Re.Re and Cl.Cl distances being 10.345 and 7.209 Å, respectively. This anionic complex is coordinated to a [Cu(bipy)(2)](2+) cation in 2, through one oxalate-oxygen, giving a neutral heterometallic dinuclear unit. The Cu(II) ion shows a very distorted five-coordinated geometry, four bipy-nitrogens occuping the equatorial positions and the oxygen atom the apical one. The basal plane geometry is distorted toward the tetrahedron, the dihedral angle between the mean planes of the two bipy ligands is 37.6(2) degrees. These [ReCl(4)(&mgr;-ox)Cu(bipy)(2)] units are arranged in such a way that a chlorine atom of one of them points toward the copper atom of the neighboring one, forming helicoid chains. The intrachain Re.Cu distances through chloro and oxalato bridges are 4.658 and 4.798 Å, respectively. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8-300 K. 1 is a magnetically diluted Re(IV) complex, the great value of zero-field splitting of the ground level (D = 60 cm(-)(1)) accounting for the variation of chi(M)T with T in

  15. Electro-optic response of metal halide $\\rm{C_{s}PbI_{3}}$: A first-principles study



    A theoretical study of electronic and optical properties of metal-halide cubic perovskite, $\\rm{C_{s}PbI_{3}}$, is presented, using first-principles calculations with plane-wave pseudopotential method as implemented in the PWSCF code. In this approach, local density approximation (LDA) is used for exchange-correlation potential. A strong ionic bonding is observed between Cs and I orbitals and a weak covalent bonding is found between Pb-I and Cs-Pb orbitals. The optical properties of this compound are interesting and it has many applications in optoelectronic devices.

  16. The Intrinsic Analysis in C. S. Lewis’s Novel Prince Caspian (Book 2 In The Chronicles Of Narnia)

    Bukit, Andre Yamme Resa


    Novel is one of the literary which not only concern an interesting story, but it also contain a moral message for the readers. The paper entitles “The Intrinsic Analysis in C. S. Lewis’s Novel Prince Caspian (Book 2 In The Chronicles Of Narnia)” is about the intrinsic elements in a literary work consist of theme, plot, character, style, setting and point of view. Prince Caspian is the continued novel of “The Lion, The Witch and The Wardrobe (Book 1 In The Chronicles Of Narnia)” that written b...

  17. Active and passive vectorization of technetium{sup 99m} and {sup 188}rhenium radiopharmaceuticals for medical imaging and radiotherapy; Vectorisations active et passive de radiopharmaceutiques du technetium-99m et du rhenium-188 pour l'imagerie medicale et la therapie

    Lepareur, N


    Research for new molecules for nuclear medicine is a field in constant development. Over the past few years, development of new radiopharmaceuticals for radiotherapy has renewed interest for rhenium chemistry. Indeed, its two isotopes {sup 186}Re and {sup 188}Re, owing to their ideal properties and their similitude with {sup 99m}Tc, which is widely used as a radiotracer for diagnostic imaging, seem very promising for the preparation of radiopharmaceuticals. In the first part of this manuscript, the synthesis of rhenium and technetium-99 complexes, [M(RPhCS3)2(RPhCS2)] (M = Re, Tc), is described. The preparation of technetium{sup 99m} based radiopharmaceuticals, analogues to the pondered complexes, is also described. The stability/reactivity of these complexes has been studied by exchange reactions with potential ligands, specially dithiocarbamates, and also by UV-visible absorption spectroscopy and thermogravimetry. The reactivity of the complexes towards dithiocarbamates leads to the possibility to bind biomolecules to the metallic core, via the dithiocarbamate moiety. This method represents a potential alternative to current ones using the so-called bifunctional approach. In the second part of this manuscript, a new kit formulation for the {sup 188}Re labeling of lipiodol is described, using a complex analogous to those described in the previous part. The labeled oil is a potential cure for hepatocellular carcinoma. The in vitro and in vivo stability of this {sup 188}Re-SSS lipiodol and of its analogue {sup 99m}Tc-SSS lipiodol has been studied, and also their in vivo behavior in healthy pigs. This study has shown the quasi-exclusive hepatic fixation of the radiopharmaceutical, and has proven its good stability. Its selectivity for tumors remains to be shown before trying it on humans. (author)

  18. Metal derivatives of heterocyclic-2-thiones: Variable donor ability, C-S rupture and new structural motifs

    Tarlok S Lobana; Razia Sultana


    The chemistry of thio-ligands based on heterocyclic-2-thiones, namely, pyridine-2-thione (SNC5H5), imidazolidine-2-thione (SN2C3H6), imidazoline-2-thione (SN2C3H4), 1-methyl-imidazoline-2-thione (SN2C4H6) and thiazolidine-2-thione (S2NC3H5) with coinage and some other metals are described. The synthesis, solvent effect, isolation of new products after C-S rupture and crystal structure are also discussed. For example, copper(I) bromide with 1-methyl-imidazoline-2-thione (SN2C4H6) in acetonitrile formed CuI trinuclear complex, {Cu3(1-Br)3(-SN2C4H6)3}·CH3CN. This reaction in the presence of chloroform involved C-S bond rupture, oxidation of sulphur to sulphate and bromination of ring and formed a tetranuclear cluster, Cu4(1-N-(N2C4H5Br)4(4-O)(-Br)6] (N2C4H5Br = 2-bromo-1-methyl-imidazole). The reaction of copper(I) chloride with 1-methyl-imidazoline-2-thione (SN2C4H6) in acetonitrile also involved C-S rup ture and formed a chloro-bridged dinuclear complex [Cu2{2-N,N-(N2C4H5)2S}2(-Cl)2Cl2] {(N2C4H5)2S = 1, 1'-dimethyl-2,2'-di-imidazolyl sulphide}. Significantly copper(I) bonded to more polarisable iodide ion (Cu-I) does not involve C-S rupture and in this case it formed CuI polynuclear complex, {Cu2(-I)2(-SN2C4H6)2}. Both copper(I) chloride and copper(I) bromide with 1-methyl-imidazoline-2-thione in dimethyl sulphoxide involved C-S rupture and oxidation of sulphur to sulphate and formed a sulphate chelated CuII complex, [CuII{2-N,N-(N2C4H5)2S}(2-O,OSO2)(1-OH2)]. Imidazolidine-2-thione (SN2C3H6) with copper(I) chloride/bromide in dimethyl sulphoxide gave a sulphate bridged polynuclear complex, [CuII{2-N,N-(N2C3H5)2S}(-O,OSO2)(1-OH2)] {(N2C3H5)2S = 2,2'-thio-di-2-imidazoline}. Other metals such as silver, zinc, cadmium and mercury formed monomers or dimers.

  19. Control of light-promoted [2+2] cycloaddition reactions by a remote ancillary regulatory group that is covalently attached to rhenium rectangles.

    Lu, Zong-Zhan; Lee, Chung-Chou; Velayudham, Murugesan; Lee, Li-Wei; Wu, Jing-Yun; Kuo, Ting-Shen; Lu, Kuang-Lieh


    The high-yielding self-assembly of three neutral rhenium(I) rectangles, [Re(2)(CO)(6)(L)(bpe)](2) (1 a, L=2,2'-biimidazolate (biim); 1 b, L=2,2'-bisbenzimidazolate (bbim); 1 c, L=2,2'-bis(4,5-dimethylimidazolate) (bdmim); bpe=trans-1,2-bis(4-pyridyl)ethylene), under hydrothermal conditions is described. The rectangles were structurally characterized by spectroscopic techniques and further confirmed by single-crystal X-ray diffraction. Upon irradiation with a Hg lamp at 365 nm, the bpe ligands of rectangles 1 a and 1 b underwent [2+2] photocycloaddition reactions to produce [{(Re(CO)(3))(2)L}(2)(4,4'-tpcb)(2)] (2 a, L=biim; 2 b, L=bbim; 4,4'-tpcb=1,2,3,4-tetrakis(4-pyridyl)cyclobutane) through a single-crystal-to-single-crystal (SCSC) transformation. However, rectangle 1 c, which contained methyl groups on the 2,2'-biimidazolate ligand, failed to undergo cycloaddition, even after prolonged irradiation. This result indicates that the light-induced cycloaddition reaction can be preferentially controlled by the remote regulatory substituents, which are attached onto the same backbone of the rectangle complex. This transformation is the first reported utilization of a remote ancillary regulatory ligand that is covalently attached onto a coordination compound to control the [2+2] cycloaddition reaction. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Prediction of the correct measured activity of {sup 186}Re and {sup 188}Re from reactor produced natural rhenium using an artificial neural network

    Leila Moghaddam, B., E-mail: [Faculty of Nuclear Engineering and Physics, Amirkabir Technical University (Tehran Polytechnic), Hafez Street, Tehran (Iran, Islamic Republic of); Setayeshi, Saeed; Maragheh, Mohammad G.; Gholipour, Reza [Faculty of Nuclear Engineering and Physics, Amirkabir Technical University (Tehran Polytechnic), Hafez Street, Tehran (Iran, Islamic Republic of)


    To optimize the cost effectiveness of {sup 186}Re and {sup 188}Re production, which have recently been used as radio pharmaceuticals for therapeutic purposes, we designed an artificial neural network (ANN) to evaluate the activity of combined {sup 186}Re + {sup 188}Re. One of the production ways is the (n,gamma) reaction of natural rhenium which leads to combined {sup 186}Re + {sup 188}Re. Using the counted activity of {sup 186}Re + {sup 188}Re mixtures by a well type isotope calibrator, the precise activity of {sup 186}Re and {sup 188}Re is obtained by the ANN. A back-propagation ANN was trained using 30 activities of mixed {sup 186}Re + {sup 188}Re. The performance of the ANN was tested by Early-Stopping validation method, and the ANN was optimized with respect to its architecture. The response of the ANN shows significant precision that may be used for medical application of {sup 186}Re + {sup 188}Re mixtures.

  1. Ciencia y técnica en la anticiencia ficción de C. S. Lewis

    Burgos López, Campo Ricardo


    El artículo analiza la imagen que de la ciencia y la técnica occidentales (y por extensión de la civilización en que ellas son preeminentes); plantea C.S. Lewis en su Trilogía Cósmica (obra clásica de la literatura fantástica y religiosa del siglo XX). Ante la cultura científico-técnica predominante en la actualidad; en estas tres novelas Lewis propone una civilización enraizada en el Cristianismo. Frente a una cultura científico-técnica que acaba promoviendo la deshumanización; la discrimina...

  2. Cement hydration from hours to centuries controlled by diffusion through barrier shells of C-S-H

    Rahimi-Aghdam, Saeed; Bažant, Zdeněk P.; Abdolhosseini Qomi, M. J.


    Although a few good models for cement hydration exist, they have some limitations. Some do not take into account the complete range of variation of pore relative humidity and temperature, and apply over durations limited from up a few months to up to about a year. The ones that are applicable for long durations are either computationally too intensive for use in finite element programs or predict the hydration to terminate after few months. However, recent tests of autogenous shrinkage and swelling in water imply that the hydration may continue, at decaying rate, for decades, provided that a not too low relative pore humidity (above 0.7) persists for a long time, as expected for the cores of thick concrete structural members. Therefore, and because design lifetimes of over hundred years are required for large concrete structures, a new hydration model for a hundred year lifespan and beyond is developed. The new model considers that, after the first day of hydration, the remnants of anhydrous cement grains, gradually consumed by hydration, are enveloped by contiguous, gradually thickening, spherical barrier shells of calcium-silicate hydrate (C-S-H). The hydration progress is controlled by transport of water from capillary pores through the barrier shells toward the interface with anhydrous cement. The transport is driven by a difference of humidity, defined by equivalence with the difference in chemical potential of water. Although, during the period of 4-24 h, the C-S-H forms discontinuous nano-globules around the cement grain, an equivalent barrier shell control was formulated for this period, too, for ease and effectiveness of calculation. The entire model is calibrated and validated by published test data on the evolution of hydration degree for various cement types, particle size distributions, water-cement ratios and temperatures. Computationally, this model is sufficiently effective for calculating the evolution of hydration degree (or aging) at every

  3. Synthesis, characterization, and gas-phase fragmentation of rhenium-carbonyl complexes bearing imidazol(in)ium-2-dithiocarboxylate ligands.

    Beltrán, Tomás F; Zaragoza, Guillermo; Delaude, Lionel


    Five complexes with the generic formula [ReBr(CO)3(κ(2)-S,S'-S2C·NHC)] were obtained by reacting [ReBr(CO)5] with a set of representative imidazol(in)ium-2-dithiocarboxylate zwitterions. These ligands are the adducts of N-heterocyclic carbenes (NHCs) and carbon disulfide. The monometallic Re(i) compounds were further coupled with Na[Re(CO)5] to afford bimetallic Re(0) species. Depending on the experimental conditions, either octacarbonyl dimers [Re2(CO)8(μ2-κ(1)-S,κ(1)-S'-S2C·NHC)] or hexacarbonyl clusters [Re2(CO)6(κ(2)-S,S'-κ(3)-S,C,S'-S2C·NHC)] were isolated. All the products were fully characterized using various analytical techniques. Single crystal XRD analysis helped establish with certainty the various binding modes exhibited by the NHC·CS2 ligands. With bite angles ranging from ca. 104 to 130°, these zwitterions displayed a remarkable flexibility, which also permitted significant twists of the thiometallated rings to preserve a staggered arrangement of the carbonyl groups in the bimetallic systems. Monitoring the chemical shift of the CS2(-) moiety by (13)C NMR spectroscopy was most useful to detect its change of hapticity upon decarbonylation of the octacarbonyl compounds into hexacarbonyl derivatives. IR spectroscopy was another very convenient tool to identify the type of complex formed in a reaction, based on the pattern of its carbonyl vibration bands. Advanced mass spectrometry techniques showed that all the compounds underwent partial or total decarbonylation in the gas phase with no concomitant fragmentation of the bimetallic assemblies into monometallic ions.

  4. 协同萃取法回收地浸采铀工艺树脂中铼%Synergistic Extraction of Rhenium from In-Situ Leach Uranium Mining Technology Resin

    彭真; 罗明标; 蒋小辉; 花榕; 廖桢葳


    Synergistic extraction of rhenium with primary amines and tributylphosphate was studied. The effects of initial pH value, composition of the extractant, and volume ratio of organic phase to aqueous phase on the extraction of rhenium were studied. The results showed that the synergistic extraction efficiency of rhenium was above 97% at pH 2-10, while dissolving loss of primary amine ( N1923) in acid condition was great. The optimum conditions were obtained with initial pH value of 9.5 with 30% N1923, 50% TBP and 20% sulphonating kerosene as extractant, 3% NaOH as stripping reagent, phase ratio of 1: 1. The extraction efficiency was above 99% , and stripping efficiency was above 97%. The distribution ratio of rhenium increased with the increase of initial concentration of rhenium, and the extraction rate of rhenium was not influenced by the uranium existed in aqueous phase, and hardly influenced by nitrate. During the progress of in-situ sulfuric acid leaching technique of uranium, U and Re in the forms of [ UO2 (SO4 )2 ]2- , [ UO2 (SO4)3]4- , ReO4- were brought into leaching solution, and simultaneously absorbed by anion exchange resin D231. Uranium was stripped by nitrate or chloride from in-situ leach uranium mining technology resin, then rhenium was stripped by 10% NH4NO3 and 8% NH40H. It was effective, for the recovery of rhenium from desorption solution by primary amines and tributylphosphate synergistic extraction that provided parameters for further industry investigation for recovery of rhenium from uranium ore.%介绍了伯胺和磷酸三丁酯协同萃取回收铼的实验研究,考察了水相初始pH值、萃取剂组成、相比(O/W)对铼萃取率的影响.结果表明:协同萃取体系在pH 2~10范围内铼的萃取率均在97%以上,但酸性条件下伯胺N1923溶解损失较大,水相初始pH9.5为最佳萃取酸度,以有机相30% N1923-50%TBP-20%磺化煤油萃取铼效果最佳,并采用3% NaOH反萃铼,

  5. Characterization of C-S lyase from Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 and its potential role in food flavour applications.

    Allegrini, Alessandra; Astegno, Alessandra; La Verde, Valentina; Dominici, Paola


    Volatile thiols have substantial impact on the aroma of many beverages and foods. Thus, the control of their formation, which has been linked to C-S lyase enzymatic activities, is of great significance in industrial applications involving food flavours. Herein, we have carried out a spectroscopic and functional characterization of a putative pyridoxal 5'-phosphate (PLP)-dependent C-S lyase from the lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 (LDB C-S lyase). Recombinant LDB C-S lyase exists as a tetramer in solution and shows spectral properties of enzymes containing PLP as cofactor. The enzyme has a broad substrate specificity toward sulphur-containing amino acids with aminoethyl-L-cysteine and L-cystine being the most effective substrates over L-cysteine and L-cystathionine. Notably, the protein also reveals cysteine-S-conjugate β-lyase activity in vitro, and is able to cleave a cysteinylated substrate precursor into the corresponding flavour-contributing thiol, with a catalytic efficiency higher than L-cystathionine. Contrary to similar enzymes of other lactic acid bacteria however, LDB C-S lyase is not capable of α,γ-elimination activity towards L-methionine to produce methanethiol, which is a significant compound in flavour development. Based on our results, future developments can be expected regarding the flavour-forming potential of Lactobacillus C-S lyase and its use in enhancing food flavours.

  6. Synthesis, spectroscopic, electrochemical and computational studies of rhenium(I) dicarbonyl complexes based on meridionally-coordinated 2,2':6',2''-terpyridine.

    Frenzel, Blaise A; Schumaker, Josh E; Black, Daniel R; Hightower, Sean E


    A homologous series of meridionally-coordinated tridentate 2,2':6',2''-terpyridine Re(I) dicarbonyl complexes have been prepared and investigated. The complexes mer,cis-[Re(tpy-κ(3)N)(CO)2(L)](n) (L = Cl(-) (1), OSO2CF3(-) (2), NCCH3 (3), CN(-) (4), NC5H5 (5), PMe3 (6), PEt3 (7), PPh3 (8), P(OMe)3 (9) and P(OEt)3 (10); n = 0 or +1) have been synthesized and characterized by elemental analysis, (1)H NMR and infrared spectroscopy. The electrochemistry of these compounds has been studied and compared to that of other known rhenium compounds using an electrochemical parameterization model. Cyclic voltammetry measurements have shown that the first oxidation of the complexes varies systematically in potential as the ligand L is altered. Many of these one-electron oxidations occur at lower potentials compared to more familiar bidentate diimine Re(I) tricarbonyl complexes. A correlation exists between CO, a strong π-acidic ligand, and deviations of the observed reduction potentials from the calculated values. Many of the complexes absorb light throughout a significant portion of the visible spectrum. Two of these complexes, mer,cis-Re(tpy-κ(3)N)(CO)2Cl (1) and mer,cis-Re(tpy-κ(3)N)(CO)2CN (4), absorb light throughout the entire visible spectrum. Low temperature emission spectra were obtained for the compounds mer,cis-Re(tpy-κ(3)N)(CO)2Cl (1) and mer,cis-[Re(tpy-κ(3)N)(CO)2(P(OEt)3)](+) (10) at 77 K in a 4 : 1 methanol-ethanol glass matrix and give metal-to-ligand charge transfer ((3)MLCT) luminescence. Density functional theory (DFT) calculations of the electronic structure are in good agreement with the experimental data.

  7. Comparative therapeutic efficacy of rhenium-188 radiolabeled-liposome and 5-fluorouracil in LS-174T human colon carcinoma solid tumor xenografts.

    Hsu, Chin-Wei; Chang, Ya-Jen; Chang, Chih-Hsien; Chen, Liang-Cheng; Lan, Keng-Li; Ting, Gann; Lee, Te-Wei


    Nanoliposomes are important carriers capable of packaging drugs for various delivery applications. Rhenium-188-radiolabeled liposome ((188)Re-liposome) has potential for radiotherapy and diagnostic imaging. To evaluate the targeting of (188)Re-liposome, biodistribution, microSPECT/CT, whole-body autoradiography (WBAR), and pharmacokinetics were performed in LS-174T human tumor-bearing mice. The comparative therapeutic efficacy of (188)Re-liposome and 5-fluorouracil (5-FU) was assessed according to inhibition of tumor growth and the survival ratio. The highest uptake of (188)Re-liposome in LS-174T tumor was found at 24 hours by biodistribution and microSPECT/CT imaging, showing a positive correlation for tumor targeting of (188)Re-liposome using the Pearson's correlation analysis (r=0.997). Pharmacokinetics of (188)Re-liposome showed the properties of high circulation time and high bioavailability (mean residence time [MRT]=18.8 hours, area under the curve [AUC]=1371%ID/g·h). For therapeutic efficacy, the tumor-bearing mice treated with (188)Re-liposome (80% maximum tolerated dose [MTD], 23.7 MBq) showed better tumor growth inhibition and longer survival time than those treated with 5-FU (80% MTD, 144 mg/kg). The median survival time for mice treated with (188)Re-liposome (58.5 days; p0.05) and normal saline-treated mice (43.63 days). Dosimetry study revealed that the (188)Re-liposome did not lead to high absorbed doses in normal tissue, but did in small tumors. These results of imaging and biodistribution indicated the highly specific accumulation of tumor after intravenous (i.v.) injection of (188)Re-liposome. The therapeutic efficacy of radiotherapeutics of (188)Re-liposome have been confirmed in a LS-174T solid tumor animal model, which points to the potential benefit and promise of passive nanoliposome delivered radiotherapeutics for cancer treatment.

  8. Applying quality by design principles to the small-scale preparation of the bone-targeting therapeutic radiopharmaceutical rhenium-188-HEDP.

    Lange, Rogier; Ter Heine, Rob; van der Gronde, Toon; Selles, Suzanne; de Klerk, John; Bloemendal, Haiko; Hendrikse, Harry


    Rhenium-188-HEDP ((188)Re-HEDP) is a therapeutic radiopharmaceutical for treatment of osteoblastic bone metastases. No standard procedure for the preparation of this radiopharmaceutical is available. Preparation conditions may influence the quality and in vivo behaviour of this product. In this study we investigate the effect of critical process parameters on product quality and stability of (188)Re-HEDP. A stepwise approach was used, based on the quality by design (QbD) concept of the ICH Q8 (Pharmaceutical Development) guideline. Potential critical process conditions were identified. Variables tested were the elution volume, the freshness of the eluate, the reaction temperature and time, and the stability of the product upon dilution and storage. The impact of each variable on radiochemical purity was investigated. The acceptable ranges were established by boundary testing. With 2ml eluate, adequate radiochemical purity and stability were found. Nine ml eluate yielded a product that was less stable. Using eluate stored for 24h resulted in acceptable radiochemical purity. Complexation for 30min at room temperature, at 60°C and at 100°C generated appropriate and stable products. A complexation time of 10min at 90°C was too short, whereas heating 60min resulted in products that passed quality control and were stable. Diluting the end product and storage at 32.5°C resulted in notable decomposition. Two boundary tests, an elution volume of 9ml and a heating time of 10min, yielded products of inadequate quality or stability. The product was found to be instable after dilution or when stored above room temperature. Our findings show that our previously developed preparation method falls well within the proven acceptable ranges. Applying QbD principles is feasible and worthwhile for the small-scale preparation of radiopharmaceuticals. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Self y creatividad en el pragmatismo de C.S. Peirce: "la incidencia del instante presente en la conducta"

    Fernando Andacht


    Full Text Available El artículo presenta una reflexión sobre la relevancia teórica y analítica de la creatividad y de la espontaneidad, consideradas como un aspecto central del modelo semiótico de C.S. Peirce, y lo hace a través del estudio de su incidencia en la identidad humana, en el self. Para ello, apelo a una serie de conceptos técnicos de la te ría de los signos peirceana, los cuales son aplicados a un abordaje analítico contemporáneo de un film de ficción realista. En su trama narrativa, bajo la forma de una alegoría realista, es posible contemplar el proceso en virtud del cual emerge en la vida de cada día la tendencia creativa al cambio, en fuerte tensión con su opuesto, la tendencia conservadora que, en caso de adquirir una hegemonía excesiva, busca convertir un estado concreto de cosas en algo permanente y opresor para la vida humana concebida como el aumento continuo de razonabilidad.

  10. Deep Eutectic Solvents as Reaction Media for the Palladium-Catalysed C-S Bond Formation: Scope and Mechanistic Studies.

    Marset, Xavier; Guillena, Gabriela; Ramón, Diego J


    A unique jigsaw catalytic system based on deep eutectic solvents and palladium nanoparticles where C-S bonds are formed from aryl boronic acids and sodium metabisulfite, is introduced. The functionalization step is compatible with a broad spectrum of reagents such as nucleophiles, electrophiles or radical scavengers. This versatile approach allows the formation of different types of products in an environmentally friendly medium by selecting the components of the reaction, which engage one with another as pieces in a jigsaw. This simple procedure avoids the use of toxic volatile organic solvents allowing the formation of complex molecules in a one-pot reaction under mild conditions. Despite the fact that only 1 mol % of metal loading is used, the recyclability of the catalytic system is possible. Kinetic experiments were performed and the reaction order for all reagents, catalyst and ligand was determined. The obtained results were compared to palladium nanocrystals of different known shapes in order to shed some light on the properties of the catalyst. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The creative word and poetic visions of the world. The beginnings of an epic fantasy in C. S. Lewis

    Gutierrez Bautista, O. D.


    Full Text Available The enormous popularity of the book series The Chronicles of Narnia by British author C. S. Lewis invites the study of the work´s artistic quality that forms part of the beginning of the epic fantasy; not only because it represents a milestone in literary history, but also because it remains an expression of fundamental human needs that, in the same manner, were found in post-war days ofthe twentieth century, as observed in the great questions of postmodernity. The crisis of the greatstories generally expressed by religions and thecultural dissolution of major literary referencesproduce a fertile ground for the emergence ofliterary works, such as The Chronicles of Narnia,and propose a vision of the world and a projectfor the future. In this paper we will analyze theartistic value of The Magician’s Nephew (1955, abook which opens the collection of children’s books,as a work that offers a poetic vision of the worldwith the Judeo-Christian religious background ofcreation.

  12. Synthesis and investigation of CrB{sub 4}, MnB{sub 4} and new ternary chromium and rhenium manganese borides; Synthese und Untersuchung von CrB{sub 4}, MnB{sub 4} sowie neuen ternaeren Chrom- und Rheniummanganboriden

    Knappschneider, Arno


    In the present work single crystals of the tetraborides of chromium and manganese have been grown and allowed a structure refinement of the compounds. Furthermore the physical characteristics for example hardness, electronic properties and magnetism were been determined. Also the ternary tetraboride phase of chromium and manganese was synthesized and a new ternary rhenium manganese diboride could be obtained.

  13. 基于 C/S 架构的气象观测站点智能统计系统%An intelligent statistical system of meteorological observation station based on C/S architecture

    王磊; 杨涛


    随着我国气象事业的快速发展,各类气象观测站点数量越来越多,及时准确的统计各类观测站点的业务可用性数据对提高气象预报质量是至关重要的。传统人工统计主要采用常见的 Office 办公软件,耗时长且错误率高,特别是当出现交叉数据或关联数据且数据量相当大时,则人工无法是完成的。针对这一问题,建立了一个基于 C/S 架构的气象观测站点智能统计系统。该智系统在技术上采用了 VC++编程语言。并采用 VS.2008软件开发工具及SQL Server2008数据库协同开发。系统分为服务器端和客户端,分别实现数据的存储管理和逻辑操作。软件测试运行后,实现自动化站点业务统计查询和报表打印,大大提高了工作效率,并降低了数据的出错率。该系统能够在全省局域网范围内实现智能化观测站点统计管理。%With the rapid development of meteorological service in China,the number of various kinds of meteorological observation stations increases more and more.It is important that we must do the statistics for the available business data of various kinds of observation stations accurately to improve the quality of the weather forecast.Traditional artificial statistics mainly adopts common office software.The defect of this mode is the time consuming and high error rate.The artificial mode could not complete the assignment when there was a large amount of the cross or associated data.In order to solve this problem,this paper establishes an intelligent statistical system of meteorological observation station based on C/S architecture.The VC + + programming language is used in this intelligent system.The VS.2008 software development tools and the SQL Server 2008 database software are also be used.This system is divided into client part and server part.They could realize the data storage management and logical operation respectively.After testing and operating

  14. Theoretical studies on the electronic structures and photoelectron spectra of tri-rhenium oxide clusters: Re3O(n)(-) and Re3O(n) (n=1-6).

    Zhou, Qi; Gong, Wei-Chao; Xie, Lu; Zheng, Cun-Gong; Zhang, Wei; Wang, Bin; Zhang, Yong-Fan; Huang, Xin


    Density functional theory (DFT) calculations are performed to study the structural and electronic properties of tri-rhenium oxide clusters Re3On(-/0) (n=1-6). Generalized Koopmans' theorem is applied to predict the vertical detachment energies (VDEs) and simulate the photoelectron spectra (PES). Theoretical calculations at the B3LYP level are carried out to search for the global minima for both the anions and the neutrals. For the anions, the first two O atoms prefer the same corner position of a Re3 triangle. Whereas, Re3O3(-) possesses a C2v symmetry with one bridging and two terminal O atoms. The next three O atoms (n=4-6) are adding sequentially on the basis of Re3O3(-) motif, i.e., adding one terminal O atom for Re3O4(-), one terminal and one bridging O atoms for Re3O5(-), and one terminal and two bridging O atoms for Re3O6(-), respectively. Their corresponding neutral species are similar to the anions in geometry except Re3O4 and Re3O5. Molecular orbital analyses are employed to investigate the chemical bonding and structural evolution in these tri-rhenium oxide clusters. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Adsorption of gluconate and uranyl on C-S-H phases: Combination of wet chemistry experiments and molecular dynamics simulations for the binary systems

    Androniuk, Iuliia; Landesman, Catherine; Henocq, Pierre; Kalinichev, Andrey G.


    As a first step in developing better molecular scale understanding of the effects of organic additives on the adsorption and mobility of radionuclides in cement under conditions of geological nuclear waste repositories, two complementary approaches, wet chemistry experiments and molecular dynamics (MD) computer simulations, were applied to study the sorption behaviour of two simple model systems: gluconate and uranyl on calcium silicate hydrate phases (C-S-H) - the principal mineral component of hardened cement paste (HCP). Experimental data on sorption and desorption kinetics and isotherms of adsorption for gluconate/C-S-H and U(VI)/C-S-H binary systems were collected and quantitatively analysed for C-S-H samples synthesised with various Ca/Si ratios (0.83, 1.0, 1.4) corresponding to various stages of HCP aging and degradation. Gluconate labelled with 14C isotope was used in order to improve the sensitivity of analytical detection technique (LSC) at particularly low concentrations (10-8-10-5 mol/L). There is a noticeable effect of Ca/Si ratio on the gluconate sorption on C-S-H, with stronger sorption at higher Ca/Si ratios. Sorption of organic anions on C-S-H is mediated by the presence of Ca2+ at the interface and strongly depends on the surface charge and Ca2+ concentration. In parallel, classical MD simulations of the same model systems were performed in order to identify specific surface sorption sites most actively involved in the sorption of gluconate and uranyl on C-S-H and to clarify molecular mechanisms of adsorption.

  16. 地质样品中铼的密闭消解电感耦合等离子体质谱测定法%Determination of Rhenium in Geological Samples by Closed-vessel Digestion ICP-MS

    朱晓贤; 王强; 乔宁强; 薛志伟


    The optimal conditions for testing rhenium in geological samples using Inductively Coupled Plasma -Mass Spectrometry (ICP-MS ) method was discussed and the defects caused by the original testing method such as low sensi-tivity that couldn’ t meet the requirements of testing the geological samples with low rhenium content were successfully avoided .Considering the disadvantages of unstability and easy volatilization of Rhenium in acid solutions ,geological sam-ples were treated under closed-vessel digestion by nitric acid and H2O2 to avoid Rhenium decomposition .After the test method was confirmed ,several blank tests were carried out according to the test conditions and the sample treatment pro-cess .The detect limit for 3σ(standard deviation ) was 1 .60 ng/g ,and for 10σwas 5 .32 ng/g .The addition standard re-covery rate was 95 .8% to 101 .1% .Precision test was performed on China national standard material GBWO7238 .The relative standard deviation ( n=6 ) was 7 .3% .And then ,the method was applied to six different concentration levels of this standard material and the test results were in accordance with the certified value .Therefore this method can meet the requirement of testing rhenium in geological samples .%针对铼在酸性溶液中不稳定易挥发损失的缺点,采用硝酸、过氧化氢密闭中压消解处理,解决了铼的分解问题。探讨了等离子体质谱法测量地质样品中铼的最佳条件,解决了原测量方法灵敏度低,不能满足地质样品中低含量铼测定的缺陷。在试验方法确定的条件下,按照仪器测量条件及试样处理全过程进行数份空白试验,以3倍标准偏差计算仪器的检出限为1.60 ng/g ,10倍标准偏差计算方法的检出限为5.32 ng/g ;方法的加标回收率在95.8%~101.1%。对国家标准物质GBWO7238进行精密度试验,相对标准偏差( n=6)7.3%。方法应用于6个不同含量级别的国家标准物质中

  17. Design criteria for rhenium-reduced nickel-based single-crystal alloys. Identification and computer-assisted conversion; Designkriterien fuer rheniumreduzierte Nickelbasis-Einkristalllegierungen. Identifikation und rechnergestuetzte Umsetzung

    Goehler, Thomas


    In the present work, design criteria and property models for the creep strength optimization of rhenium-free nickel based single crystal Superalloys are investigated. The study focuses on a typical load condition of 1050 C and 150 MPa, which is representative for flight engine applications. Thereby the key aspect is to link chemical composition, manufacturing processes, microstructure formation and mechanistic understanding of dislocation creep through a computational materials engineering approach. Beside the positive effect of rhenium on solid solution hardening, a second mechanism in which rhenium increases high temperature creep strength is identified. It indirectly stabilizes precipitation hardening by reducing the coarsening kinetics of γ'-rafting. Five 1st and 2nd generation technical Superalloys show a comparable microstructure evolution for up to 2 % plastic elongation, while creep times differ by a factor of five. The application of a microstructure sensitive creep model shows that these coarsening processes can activate γ-cutting and thus lead to an increasing creep rate. Based on these calculations a threshold value of φ{sub γ/γ'} > 2,5 at 150 MPa is estimated. This ratio of matrix channel to raft thickness has been proofed for multiple positions by microstructure analysis of interrupted creep tests. The mechanism described previously can be decelerated by the enrichment of the γ-matrix with slow diffusing elements. The same principle also increases the solid solution strength of the γ-matrix. Therefore, the present work delivers an additional mechanistic explanation why creep properties of single phase nickel based alloys can be transferred to two phase technical Superalloys with rafted γ'-structure. Following, the best way to substitute both rhenium fundamental properties, namely a slow diffusion coefficient and a small solubility in g', has been investigated by means of CALPHAD-modeling. Only molybdenum and especially

  18. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C3S, β-C2S and their blends

    Dolado, J. S.


    Full Text Available The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C3S, β-C2S and their blends are studied by Nitrogen sorption and nanoindentation experiments. The surface area and nanoporosity of C-S-H gels formed from the hydration of β-C2S and the 30-70 (T1-C3S and β-C2S mixture are higher than those from hydration of T1-C3S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nanoindentation study, which shows the greater relative volume of C-S-H phases with lower densities in the β-C2S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from 29Si magic-angle-spinning (MAS NMR, of the C-S-H gels.La caracterización textural y mecánica de geles C-S-H formados a partir de la hidratación de muestras puras de T1-C3S, ß-C2S y sus mezclas ha sido estudiada por medio de adsorción de nitrógeno y nanoindentación. El área superficial y la nano-porosidad de los geles formados durante la hidratación del ß-C2S y la mezcla 30-70 (T1-C3S- ß-C2S son mayores que los correspondientes a los geles del T1-C3S, y la mezcla 70-30; esta diferencia disminuye con el tiempo de hidratación. Estos cambios coinciden con los resultados de nanoindentación que indican un aumento de volumen relativo de las fases C-S-H con una densidad menor en el caso del ß-C2S y la mezcla 30-70. Al aumentar el tiempo de hidratación, el volumen relativo de fases C-S-H de mayor densidad aumenta a expensas de aquellas de menor densidad. Importantes correlaciones cuantitativas se establecen entre las características texturales y la longitud de cadena media del gel C-S-H, determinada mediante RMN-MAS de 29Si.

  19. Are PrP(C)s involved in some human myelin diseases? Relating experimental studies to human pathology.

    Veber, Daniela; Scalabrino, Giuseppe


    We have experimentally demonstrated that cobalamin (Cbl) deficiency increases normal cellular prion (PrP(C)) levels in rat spinal cord (SC) and cerebrospinal fluid (CSF), and decreases PrP(C)-mRNA levels in rat SC. Repeated intracerebroventricular administrations of anti-octapeptide repeat-PrP(C)-region antibodies to Cbl-deficient (Cbl-D) rats prevent SC myelin lesions, and the administrations of PrP(C)s to otherwise normal rats cause SC white matter lesions similar to those induced by Cbl deficiency. Cbl positively regulates SC PrP(C) synthesis in rat by stimulating the local synthesis of epidermal growth factor (EGF), which also induces the local synthesis of PrP(C)-mRNAs, and downregulating the local synthesis of tumor necrosis factor(TNF)-α, thus preventing local PrP(C) overproduction. We have clinically demonstrated that PrP(C) levels are increased in the CSF of patients with subacute combined degeneration (SCD), unchanged in the CSF of patients with Alzheimer's disease and amyotrophic lateral sclerosis, and decreased in the CSF and SC of patients with multiple sclerosis (MS), regardless of its clinical course. We conclude that SCD (human and experimental) is a neurological disease due to excess PrP(C) without conformational change and aggregation, that the increase in PrP(C) levels in SCD and Cbl-D polyneuropathy and their decrease in MS CNS make them antipodian myelin diseases in terms of quantitative PrP(C) abnormalities, and that these abnormalities are related to myelin damage in the former, and impede myelin repair in the latter.

  20. Phosphorylated Pol II CTD recruits multiple HDACs, including Rpd3C(S), for methylation-dependent deacetylation of ORF nucleosomes.

    Govind, Chhabi K; Qiu, Hongfang; Ginsburg, Daniel S; Ruan, Chun; Hofmeyer, Kimberly; Hu, Cuihua; Swaminathan, Venkatesh; Workman, Jerry L; Li, Bing; Hinnebusch, Alan G


    Methylation of histone H3 by Set1 and Set2 is required for deacetylation of nucleosomes in coding regions by histone deacetylase complexes (HDACs) Set3C and Rpd3C(S), respectively. We report that Set3C and Rpd3C(S) are cotranscriptionally recruited in the absence of Set1 and Set2, but in a manner stimulated by Pol II CTD kinase Cdk7/Kin28. Consistently, Rpd3C(S) and Set3C interact with Ser5-phosphorylated Pol II and histones in extracts, but only the histone interactions require H3 methylation. Moreover, reconstituted Rpd3C(S) binds specifically to Ser5-phosphorylated CTD peptides in vitro. Hence, whereas interaction with methylated H3 residues is required for Rpd3C(S) and Set3C deacetylation activities, their cotranscriptional recruitment is stimulated by the phosphorylated CTD. We further demonstrate that Rpd3, Hos2, and Hda1 have overlapping functions in deacetylating histones and suppressing cotranscriptional histone eviction. A strong correlation between increased acetylation and lower histone occupancy in HDA mutants implies that histone acetylation is important for nucleosome eviction. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Comparative Photocatalytic Degradation of Monoazo and Diazo Dyes Under Simulated Visible Light Using Fe3+/C/S doped-TiO2 Nanoparticles.

    Anku, William Wilson; Oppong, Samuel Osei-Bonsu; Shukla, Sudheesh Kumar; Govender, Poomani Penny


    This research work delved into the photocatalytic degradation of monoazo dye (methyl orange) and diazo dye (congo red) in aqueous solution using Fe3+/C/S-doped TiO2 nanocomposites. The nanocomposites were synthesised through sol-gel method and characterized using XRD, FTIR, SEM, TEM, EDX, BET and UV-Vis. Photocatalytic degradation of the dyes was monitored under simulated visible light using pristine TiO2, C/S/doped-TiO2 and Fe3+/C/S doped-TiO2 with varying concentrations of Fe3+. The influence of catalyst doping, solution pH, and light intensity were also examined. Doping TiO2 with Fe3+/C/S caused reduction in its band gap value with the resultant improvement in its visible light activity. The photocatalytic efficiency of the catalysts is given as follows: TiO2 TiO2 TiO2 with Fe3+/C/S-TiO2 (0.3% Fe3+) as the best performing photocatalyst. The monoazo dye experienced higher degradation efficiency than the diazo dye. Degradation of the azo dyes was observed to decrease with increasing pH from 2 to 12. Increased visible light intensity enhanced the photodegradation efficiency of the dye. Dye decolourization was observed to be faster than its mineralization.

  2. Metatranscriptomic Evidence of Chemolithoautotrophy in the Rifle (CO) Subsurface Relevant to C, S, N, and Fe Cycling

    Beller, H. R.; Jewell, T. N. M.; Karaoz, U.; Thomas, B. C.; Banfield, J. F.; Brodie, E.; Williams, K. H.


    Although there is a limited understanding of the chemolithoautotrophic activity of aquifer microorganisms, such subsurface microbial activity could greatly influence the cycling of elements such as C, S, N, and Fe. Here, we present transcriptional (RNA-Seq) evidence of the emergence of such chemolithoautotrophic activities in groundwater filter samples from a 2-month experiment in which up to 1.5 mM nitrate (a native electron acceptor) was injected into a perennially suboxic/anoxic aquifer (Rifle, CO) containing a large reservoir of reduced Fe- and S-containing compounds. Illumina sequence data from rRNA-subtracted cDNA libraries was assembled and mapped to phylogenetically binned Rifle metagenome data. Indicative of the activity of Fe(II)-oxidizing bacteria, many high-abundance transcripts mapped to the Gallionellaceae family, whose known members are chemolithoautotrophic bacteria that catalyze Fe(II) oxidation. For example, included among the most abundant transcripts were a cold-shock protein and an acyl carrier protein with 96-98% protein sequence identity to Gallionella capsiferriformans and a nitrite reductase (nirS) gene likely belonging to a Sideroxydans relative. The apparent activity of Gallionellaceae members is consistent with 16S rRNA iTag analyses of these samples, which indicated that Gallionella-related taxa accounted for up to ~50% of these communities. Evidence of sulfide oxidation also was apparent in these samples. For example, highly expressed subunits of APS reductase were very similar to those of the obligately chemolithoautotrophic S- and Fe(II)-oxidizing Thiobacillus denitrificans in terms of sequence identity (98-99%) and synteny of the mapped scaffold. Also highly expressed were a ß-Proteobacterial Form II RubisCO gene and a hydrazine oxidoreductase gene (93% identity to the planctomycete KSU-1), the latter strongly indicative of anaerobic ammonia oxidation (anammox) activity, which has seldom been reported in aquifer environments. Such

  3. The effect of group-substitution on structures and photophysical properties of rhenium(I) tricarbonyl complexes with pyridyltetrazole ligand: A DFT/TDDFT study

    Yang, Xiao-Zhu; Wang, Ya-Ling; Guo, Jing-Ye; Zhang, Ting-Ting, E-mail:; Jia, Jian-Feng; Wu, Hai-Shun


    A series of rhenium(I) tricarbonyl complexes having a general formula fac-[Re (CO){sub 3}(L)(R-N{sup ^}N)] (L = Br; N{sup ∧}N = tert-butylated pyridyltetrazole; R = −H, 1; −NO{sub 2}, 2; −CN, 3; −OCH{sub 3}, 4; −CH{sub 3}, 5) have been investigated theoretically by density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. The calculated results reveal that introductions of different groups on R position of N{sup ^}N ligand can induce changes on electronic structures, photophysical properties and emission quantum yield for these complexes. When the electron-withdrawing groups (−NO{sub 2} and −CN) are introduced in complex 2 and 3, the lowest energy absorption and emission bands are red-shifted compared with that of 1. On the contrary, the introduction of electron-donating group (−OCH{sub 3} and −CH{sub 3}) in complex 4 and 5 cause corresponding blue-shifted. For these complexes, the stronger electron-donating ability of introduced group on N{sup ^}N ligand is, the larger blue-shifted of the lowest energy absorption and emission bands is. The solvent effect on absorption and emission spectrum indicates that the lowest-energy absorption and emission bands have both red shifts with the decrease of solvent polarity. The electronic affinity (EA), ionization potential (IP) and reorganization energy (λ) results show that complex 4 may be suitable to be used as an emitter in organic light-emitting diodes OLEDs. Meanwhile the emission quantum yield of complex 4 is possibly higher than other complexes. - Highlights: • Re(I) tricarbonyl complexes with pyridyltetrazole ligand have been studied by DFT. • The introductions of groups can change structures and properties for these complexes. • The lowest-energy bands have red-shift with the decrease of solvent polarity. • The introduction of −OCH{sub 3} may increase emission quantum yield of OLEDs.

  4. Observation of inductive effects that cause a change in the rate-determining step for the conversion of rhenium azides to imido complexes.

    Travia, Nicholas E; Xu, Zhenggang; Keith, Jason M; Ison, Elon A; Fanwick, Phillip E; Hall, Michael B; Abu-Omar, Mahdi M


    The cationic oxorhenium(V) complex [Re(O)(hoz)(2)(CH(3)CN)][B(C(6)F(5))(4)] [1; Hhoz = 2-(2'-hydroxyphenyl)-2-oxazoline] reacts with aryl azides (N(3)Ar) to give cationic cis-rhenium(VII) oxoimido complexes of the general formula [Re(O)(NAr)(hoz)(2)][B(C(6)F(5))(4)] [2a-2f; Ar = 4-methoxyphenyl, 4-methylphenyl, phenyl, 3-methoxyphenyl, 4-chlorophenyl, and 4-(trifluoromethyl)phenyl]. The kinetics of formation of 2 in CH(3)CN are first-order in both azide (N(3)Ar) and oxorhenium(V) complex 1, with second-order rate constants ranging from 3.5 × 10(-2) to 1.7 × 10(-1) M(-1) s(-1). A strong inductive effect is observed for electron-withdrawing substituents, leading to a negative Hammett reaction constant ρ = -1.3. However, electron-donating substituents on phenyl azide deviate significantly from this trend. Enthalpic barriers (ΔH(‡)) determined by the Eyring-Polanyi equation are in the range 14-19 kcal mol(-1) for all aryl azides studied. However, electron-donating 4-methoxyphenyl azide exhibits a large negative entropy of activation, ΔS(‡) = -21 cal mol(-1) K(-1), which is in sharp contrast to the near zero ΔS(‡) observed for phenyl azide and 4-(trifluoromethyl)phenyl azide. The Hammett linear free-energy relationship and the activation parameters support a change in the mechanism between electron-withdrawing and electron-donating aryl azides. Density functional theory predicts that the aryl azides coordinate via N(α) and extrude N(2) directly. For the electron-withdrawing substituents, N(2) extrusion is rate-determining, while for the electron-donating substituents, the rate-determining step becomes the initial attack of the azide. The barriers for these two steps are inverted in their order with respect to the Hammett σ values; thus, the Hammett plot appears with a break in its slope.

  5. Catalytic CO2 activation assisted by rhenium hydride/B(C6F5)3 frustrated Lewis pairs--metal hydrides functioning as FLP bases.

    Jiang, Yanfeng; Blacque, Olivier; Fox, Thomas; Berke, Heinz


    Reaction of 1 with B(C6F5)3 under 1 bar of CO2 led to the instantaneous formation of the frustrated Lewis pair (FLP)-type species [ReHBr(NO)(PR3)2(η(2)-O═C═O-B(C6F5)3)] (2, R = iPr a, Cy b) possessing two cis-phosphines and O(CO2)-coordinated B(C6F5)3 groups as verified by NMR spectroscopy and supported by DFT calculations. The attachment of B(C6F5)3 in 2a,b establishes cooperative CO2 activation via the Re-H/B(C6F5)3 Lewis pair, with the Re-H bond playing the role of a Lewis base. The Re(I) η(1)-formato dimer [{Re(μ-Br)(NO)(η(1)-OCH═O-B(C6F5)3)(PiPr3)2}2] (3a) was generated from 2a and represents the first example of a stable rhenium complex bearing two cis-aligned, sterically bulky PiPr3 ligands. Reaction of 3a with H2 cleaved the μ-Br bridges, producing the stable and fully characterized formato dihydrogen complex [ReBrH2(NO)(η(1)-OCH═O-B(C6F5)3)(PiPr3)2] (4a) bearing trans-phosphines. Stoichiometric CO2 reduction of 4a with Et3SiH led to heterolytic splitting of H2 along with formation of bis(triethylsilyl)acetal ((Et3SiO)2CH2, 7). Catalytic reduction of CO2 with Et3SiH was also accomplished with the catalysts 1a,b/B(C6F5)3, 3a, and 4a, showing turnover frequencies (TOFs) between 4 and 9 h(-1). The stoichiometric reaction of 4a with the sterically hindered base 2,2,6,6-tetramethylpiperidine (TMP) furnished H2 ligand deprotonation. Hydrogenations of CO2 using 1a,b/B(C6F5)3, 3a, and 4a as catalysts gave in the presence of TMP TOFs of up to 7.5 h(-1), producing [TMPH][formate] (11). The influence of various bases (R2NH, R = iPr, Cy, SiMe3, 2,4,6-tri-tert-butylpyridine, NEt3, PtBu3) was studied in greater detail, pointing to two crucial factors of the CO2 hydrogenations: the steric bulk and the basicity of the base.

  6. Hydrodesulfurization on Transition Metal Catalysts: Elementary Steps of C-S Bond Activation and Consequences of Bifunctional Synergies

    Yik, Edwin Shyn-Lo

    The presence of heteroatoms (e.g. S, N) in crude oil poses formidable challenges in petroleum refining processes as a result of their irreversible binding on catalytically active sites at industrially relevant conditions. With increasing pressures from legislation that continues to lower the permissible levels of sulfur content in fuels, hydrodesulfurization (HDS), the aptly named reaction for removing heteroatoms from organosulfur compounds, has become an essential feedstock pretreatment step to remove deleterious species from affecting downstream processing. Extensive research in the area has identified the paradigm catalysts for desulfurization; MoSx or WSx, promoted with Co or Ni metal; however, despite the vast library of both empirical and fundamental studies, a clear understanding of site requirements, the elementary steps of C-S hydrogenolysis, and the properties that govern HDS reactivity and selectivity have been elusive. While such a lack of rigorous assessments has not prevented technological advancements in the field of HDS catalysis, fundamental interpretations can inform rational catalyst and process design, particularly in light of new requirements for "deep" desulfurization and in the absence of significant hydrotreatment catalyst developments in recent decades. We report HDS rates of thiophene, which belongs to a class of compounds that are most resistant to sulfur removal (i.e. substituted alkyldibenzothiophenes), over a range of industrially relevant temperatures and pressures, measured at differential conditions and therefore revealing their true kinetic origins. These rates, normalized by the number of exposed metal atoms, on various SiO 2-supported, monometallic transition metals (Re, Ru, Pt), range several orders of magnitude. Under relevant HDS conditions, Pt and Ru catalysts form a layer of chemisorbed sulfur on surfaces of a metallic bulk, challenging reports that assume the latter exists as its pyrite sulfide phase during reaction. While

  7. Management of a Septic Open Abdomen Patient with Spontaneous Jejunal Perforation after Emergent C/S with Confounding Factor of Mild Acute Pancreatitis

    Fahri Yetisir


    Full Text Available Introduction. We report the management of a septic Open Abdomen (OA patient by the help of negative pressure therapy (NPT and abdominal reapproximation anchor (ABRA system in pregnant woman with spontaneous jejunal perforation after emergent cesarean section (C/S with confounding factor of mild acute pancreatitis (AP. Presentation of Case. A 29-year-old and 34-week pregnant woman with AP underwent C/S. She was arrested after anesthesia induction and responded to cardiopulmonary resuscitation (CPR. There were only ash-colored serosanguinous fluid within abdomen during C/S. After C/S, she was transferred to intensive care unit (ICU with vasopressor support. On postoperative 1st day, she underwent reoperation due to fecal fluid coming near the drainage. Leakage point could not be identified exactly and operation had to be deliberately abbreviated due to hemodynamic instability. NPT was applied. Two days later source control was provided by conversion of enteroatmospheric fistula (EAF to jejunostomy. ABRA was added and OA was closed. No hernia developed at 10-month follow-up period. Conclusion. NPT application in septic OA patient may gain time to patient until adequate source control could be achieved. Using ABRA in conjunction with NPT increases the fascial closure rate in infected OA patient.

  8. Structural and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from alite hydration in the presence of sodium and potassium hydroxide

    Mendoza, Oscar, E-mail: [Grupo del Cemento y Materiales de Construcción (CEMATCO). Universidad Nacional de Colombia, Facultad de Minas, Medellín (Colombia); Giraldo, Carolina [Cementos Argos S.A., Medellín (Colombia); Camargo, Sergio S. [Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro/COPPE, Rio de Janeiro (Brazil); Tobón, Jorge I. [Grupo del Cemento y Materiales de Construcción (CEMATCO). Universidad Nacional de Colombia, Facultad de Minas, Medellín (Colombia)


    This research evaluates the effect of sodium and potassium hydroxide on the structure and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from the hydration of pure alite. Monoclinic (MIII) alite was synthesized and hydrated, using water-to-alite ratios of 0.5 and 0.6 and additions of 10% NaOH and KOH by weight of alite. Based on results of X-ray diffraction, isothermal calorimetry, thermogravimetric analysis, Nuclear Magnetic Resonance and nanoindentation, two different effects of the alkaline hydroxides on the hydration reaction of alite, both at early and later ages, can be identified: (i) a differentiated hydration process, attributed to an enhancement in calcium hydroxide (CH) precipitation and a stimulation of the C-S-H nuclei; and (ii) an increase in the elastic modulus of the C-S-H aggregations, attributed to an electrostatic attraction between positive charges from the alkaline cations and negative charges from the C-S-H structure.

  9. 基于B/S和C/S的即时通信系统%Instant Communication System Based on B/S and C/S



    This paper proposes a instant communication framework for B/S and C/S in order to construct instant communication system in B/S. It implements a instant communication system using Ajax, Flash as client technologies. This system solves the problem that the past instant communication system of C/S can't integrate with application system of B/S and realizes unified communication between systems of B/S and C/S.%为了在B/S下实现即时通信,提出一个适合于B/S和C/S的即时通信框架,选择Ajax,Flash作为客户端技术,实现一套即时通信系统.该系统克服以往C/S即时通信软件无法在B/S系统中应用的缺点,在基于B/S,C/S的系统间实现统一通信.

  10. A Comparison of Positive Outcome Expectancies: A Review of the Theories of M. F. Scheier, C. S. Carver, M. E. P. Seligman, and C. R. Snyder.

    Bird, William A.

    Research has shown that optimistic and pessimistic outcome expectancy evaluations are associated with adaptive and maladaptive levels of psychological functioning, physical wellness, and health recovery issues. The research of M. F. Scheier, C. S. Carver, M. E. P. Seligman, and C. R. Snyder supports the hypothesis that elevated optimism or…

  11. On $bullet$-lict signed graphs $L_{bullet_c}(S$ and $bullet$-line signed graphs $L_bullet(S$

    Mukti Acharya


    Full Text Available A emph{signed graph} (or, in short, emph{sigraph} $S=(S^u,sigma$ consists of an underlying graph $S^u :=G=(V,E$ and a function $sigma:E(S^ulongrightarrow {+,-}$, called the signature of $S$. A emph{marking} of $S$ is a function $mu:V(Slongrightarrow {+,-}$. The emph{canonical marking} of a signed graph $S$, denoted $mu_sigma$, is given as $$mu_sigma(v := prod_{vwin E(S}sigma(vw.$$The line-cut graph (or, in short, emph{lict graph} of a graph $G=(V,E$, denoted by $L_c(G$, is the graph with vertex set $E(Gcup C(G$, where $C(G$ is the set of cut-vertices of $G$, in which two vertices are adjacent if and only if they correspond to adjacent edges of $G$ or one vertex corresponds to an edge $e$ of $G$ and the other vertex corresponds to a cut-vertex $c$ of $G$ such that $e$ is incident with $c$.In this paper, we introduce emph{Dot-lict signed graph} (or emph{$bullet$-lict signed graph} $L_{bullet_c}(S$, which has $L_c(S^u$ as its underlying graph. Every edge $uv$ in $L_{bullet_c}(S$ has the sign $mu_sigma(p$, if $u, v in E(S$ and $pin V(S$ is a common vertex of these edges, and it has the sign $mu_sigma(v$, if $uin E(S$ and $vin C(S$.we characterize signed graphs on $K_p$, $pgeq2$, on cycle $C_n$ and on $K_{m,n}$ which are $bullet$-lict signed graphs or $bullet$-line signed graphs, characterize signed graphs $S$ so that $L_{bullet_c}(S$ and $L_bullet(S$ are balanced. We also establish the characterization of signed graphs $S$ for which $Ssim L_{bullet_c}(S$, $Ssim L_bullet(S$, $eta(Ssim L_{bullet_c}(S$ and $eta(Ssim L_bullet(S$, here $eta(S$ is negation of $S$ and $sim$ stands for switching equivalence.

  12. Computer controlled performance mapping of thermionic converters: effect of collector, guard-ring potential imbalances on the observed collector current-density, voltage characteristics and limited range performance map of an etched-rhenium, niobium planar converter

    Manista, E. J.


    The effect of collector, guard-ring potential imbalance on the observed collector-current-density J, collector-to-emitter voltage V characteristic was evaluated in a planar, fixed-space, guard-ringed thermionic converter. The J,V characteristic was swept in a period of 15 msec by a variable load. A computerized data acquisition system recorded test parameters. The results indicate minimal distortion of the J,V curve in the power output quadrant for the nominal guard-ring circuit configuration. Considerable distortion, along with a lowering of the ignited-mode striking voltage, was observed for the configuration with the emitter shorted to the guard ring. A limited-range performance map of an etched-rhenium, niobium, planar converter was obtained by using an improved computer program for the data acquisition system.

  13. Determination of rhenium by chrome black-T-sodium bromate catalytic kinetic spectrophotometry%铬黑T溴酸钠催化动力学分光光度法测定铼

    王毅梦; 樊雪梅


    A new method combined with ultraviolet visible spectrophotometry was developed for the determination of rhenium which catalyzed the reaction of chrome black‐T‐sodium bromate. The dynamic conditions of the catalytic system was determined and the catalytic reaction apparent activation energy and the reaction rate constant were calculated ,respectively ,Ea=39.12 KJ/mol and K=1.248 × 10‐3/s. Under the optimal conditions ,the rhenium concentration showed a good linear relationship with the relative ab‐sorbance in the range of 0‐10.02 mg/L ,the detection limit was 2.7675 mg/L.%基于在硫酸介质中,铼催化溴酸钠氧化铬黑T的褪色反应,建立了测定铼的光度分析新方法。确定了催化体系的动力学条件,计算得出催化反应的表观活化能 Ea =39.12 KJ/mol ,反应速率常数为K =1.248×10-3/s。在选定的试验优条件下,铼的浓度在0~10.02 m g/L范围内与相对吸光度呈良好的线性关系,检出限为2.7675 m g/L。方法所用仪器简单,操作简便。

  14. Numerical simulation on vacuum solution heat treatment and gas quenching process of a low rhenium-containing Ni-based single crystal turbine blade

    Zhe-xin Xu


    Full Text Available Numerical heat-transfer and turbulent flow model for an industrial high-pressure gas quenching vacuum furnace was established to simulate the heating, holding and gas fan quenching of a low rhenium-bearing Ni-based single crystal turbine blade. The mesh of simplified furnace model was built using finite volume method and the boundary conditions were set up according to the practical process. Simulation results show that the turbine blade geometry and the mutual shielding among blades have significant influence on the uniformity of the temperature distribution. The temperature distribution at sharp corner, thin wall and corner part is higher than that at thick wall part of blade during heating, and the isotherms show a toroidal line to the center of thick wall. The temperature of sheltered units is lower than that of the remaining part of blade. When there is no shelteration among multiple blades, the temperature distribution for all blades is almost identical. The fluid velocity field, temperature field and cooling curves of the single and multiple turbine blades during gas fan quenching were also simulated. Modeling results indicate that the loading tray, free outlet and the location of turbine blades have important influences on the flow field. The high-speed gas flows out from the nozzle is divided by loading tray, and the free outlet enhanced the two vortex flow at the end of the furnace door. The closer the blade is to the exhaust outlet and the nozzle, the greater the flow velocity is and the more adequate the flow is. The blade geometry has an effect on the cooling for single blade and multiple blades during gas fan quenching, and the effects in double layers differs from that in single layer. For single blade, the cooing rate at thin-walled part is lower than that at thick-walled part, the cooling rate at sharp corner is greater than that at tenon and blade platform, and the temperature at regions close to the internal position is

  15. [{sup 11}C]S.L.(25.1188), a new radioligand to study the monoamine oxidase type B with PET: preclinical characterisation

    Saba, W.; Valette, H.; Peyronneau, M.A.; Bramoulle, Y.; Coulon, C.; Dolle, F.; Bottlaender, M. [Service Hospitalier Frederic Joliot, IIBM/DSV, 91 - Orsay (France); Curet, O.; George, P. [Sanofi-Aventis, 92 - Bagneux (France)


    Introduction. - Monoamine oxidase (M.A.O.) is a flavin containing enzyme, that catalyzes the oxidative deamination of various amines and neurotransmitters. Two isoforms exist, M.A.O.-A and M.A.O.-B. Variations in M.A.O. activity may be associated to human disease such as Parkinson and Alzheimer disease. Few radiotracers have been developed for M.A.O. PET studies such as [{sup 11}C]deprenyl, an irreversible M.A.O.-B inhibitor. Recently an oxazolidinone derivative, S.L.- 25.1188 ((S)-5-methoxy-methyl-3-[6-(4,4,4-tri-fluoro butoxy)- benzo[d]isoxazol-3-yl]-oxazolidin-2-one), belonging to a new generation of selective and reversible M.A.O.-B inhibitors was developed and showed in vitro a high selectivity for M.A.O.B. [1]. The aim of this study was to characterize [{sup 11}C]S.L.- 25.1188 as radioligand for in vivo PET examination of M.A.O.-B. Materials and methods. - PET studies of the brain distribution were carried out in male Papio anubis baboons. Selectivity and reversibility of [{sup 11}C]S.L.-25.1188 binding for M.A.O.-B was assessed by pre-treatment or displacement experiments (30 min before and after tracer injection, respectively) using reference ligands for M.A.O.-B (deprenyl: 2 mg/kg i.v. and lazabemide: 0.5 mg/kg i.v.) or by displacement experiments using unlabelled S.L.-25.1188 (1 mg/kg, i.v., 30 min after tracer injection). Distribution volume (D.V.) was calculated using 2-tissue-compartment model. The saturable binding following pre-treatment with deprenyl was considered as the specific binding. Results. - After injection, [1{sup 1C}]S.L.-25.1188 presents a rapid phase of distribution in blood (about 5 min), followed by a elimination with T1/2 of 75 min. The Blood to plasma concentration ratio was constant during the experimentation (0.9 {+-} .04) consistent with a similar kinetic of [{sup 11}C]S.L.- 25.1188 in both blood and plasma. Metabolism analysis showed that [{sup 11}C]S.L.-25.1188 is stable in vivo. In the brain, uptake in different areas was

  16. Recent Progress in Copper-Catalyzed C-S Coupling Reactions%铜催化C-S偶联反应的研究新进展

    秦元成; 彭强


    Copper-catalyzed C-S coupling reaction is an important method for the synthesis of sulphur-containing compounds and also a hightlight on organic and catalyst chemistry. In this paper, the recent progress in copper-catalyzed C-S coupling reactions is reviewed according to the different ligands.%铜催化C-S偶联反应是有机合成中的重要手段,近年来一直是有机化学和催化化学的研究热点之一.按照反应中所使用的配体的不同对铜催化C-S偶联反应的研究新进展进行了综述.

  17. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C{sub 3}S, {beta}-C{sub 2}S and their blends; Caracterizacion textural y mecanica de geles C-S-H formados en la hidratacion de muestras sinteticas T1-C{sub 3}S, {beta}-C{sub 2}S y sus mezclas

    Goni, S.; Guerrero, A.; Puertas, F.; Hernandez, M. S.; Palacios, M.; Dolado, J. S.; Zhu, W.; Howind, T.


    The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C{sub 3}S, {beta}-C{sub 2}S and their blends are studied by Nitrogen sorption and nano indentation experiments. The surface area and nano porosity of C-S-H gels formed from the hydration of {beta}-C{sub 2}S and the 30-70 (T1-C{sub 3}S and {beta}-C{sub 2}S mixture) are higher than those from hydration of T1-C{sub 3}S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nano indentation study, which shows the greater relative volume of C-S-H phases with lower densities in the {beta}-C{sub 2}S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from {sup 2}9Si magic-angle-spinning (MAS) NMR, of the C-S-H gels. (Author) 36 refs.

  18. TBAI-Catalyzed/Water-Assisted Double C-S Bond Formations: An Efficient Approach to Sulfides through Metal-Free Three-Component Reactions.

    Chu, Xue-Qiang; Xu, Xiao-Ping; Ji, Shun-Jun


    An aqueous catalytic method for double C-S bond formations that involves alcohol derivatives, organic halides, and sodium thiosulfate has been developed. A diverse range of functionalized sulfides, including pharmaceutical and biological derivatives, can be obtained in an efficient and eco-friendly manner under air. The mechanistic studies revealed that this tetrabutylammonium-iodide-catalyzed/water-assisted reaction generated a mercaptan species as the key intermediate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Producción de A.C.S. y climatización de una vivienda unifamiliar con energía geotérmica

    Martínez Doce, Rubén


    El objetivo de este proyecto fin de carrera es el de realizar un diseño de una instalación para la producción de agua caliente sanitaria (A.C.S.), climatización de las estancias y de una piscina cubierta, de una vivienda unifamiliar mediante energía geotérmica, con el fin de proporcionar un ahorro energético utilizando una energía limpia.

  20. I/S and C/S mixed layers, some indicators of recent physical-chemical changes in active geothermal systems: The case study of Chipilapa (El Salvador)

    Beaufort, D.; Papapanagiotou, P.; patrier, P.; Fouillac, A.M.; Traineau, H.


    I/S and C/S mixed layers from the geothermal field of Chipilapa (El Salvador) have been studied in details in order to reevaluate their potential use as indicator of the thermodynamic conditions in which they were formed. It is funded that overprinting of clay bearing alteration stages is common. For a given alteration stage, the spatial variation of I/S and C/S mixed layer ininerals is controlled by kinetics of mixed layer transformation and not only by temperature. Clay geo-thermometers cannot give reliable results because the present crystal-chemical states of the I/S and C/S mixed layers is not their initial state, it was aquired during the overall hydrothermal history which post dated the nucleation of smectitic clay material at high temperature. Occurrences of smectites or smectite-rich mixed layers at high temperature in reservoirs is a promising guide for reconstruct the zones in which boiling or mixing of non isotherinal fluids occurred very recently or still presently.

  1. Effect of Curing Regime on Degree of Al3+Substituting for Si4+in C-S-H Gels of Hardened Portland Cement Pastes

    HU Chenguang; HU Shuguang; DING Qingjun; FENG Xiaoxin; HUANG Xiulin


    The effect of curing regime on degree of Al3+substituting for Si4+(Al/Si ratio) in C-S-H gels of hardened Portland cement pastes was investigated by 29Si magic angel spinning (MAS) nuclear magnetic resonance (NMR) with deconvolution technique. The curing regimes included the constant temperature (20, 40, 60 and 80℃) and variable temperature (simulated internal temperature of mass concrete with 60℃peak). The results indicate that constant temperature of 20℃is beneficial to substitution of Al3+for Si4+, and Al/Si ratio changes to be steady after 180 d. The increase of Al/Si ratio at 40℃is less than that at 20℃for 28 d. The other three regimes of high temperature increase Al/Si ratio only before 3 d, on the contrary to that from 3 to 28 d. However, the 20℃curing stage from 28 to 180 d at variable temperature regime, is beneficial to the increase of Al/Si ratio which is still lower than that at constant temperature regime of 20℃for the same age. A nonlinear relation exists between the Al/Si ratio and temperature variation or mean chain length (MCL) of C-S-H gels, furthermore, the amount of Al3+which can occupy the bridging tetrahedra sites in C-S-H structure is insufficient in hardened Portland cement pastes.

  2. Renal cysteine conjugate C-S lyase mediated toxicity of halogenated alkenes in primary cultures of human and rat proximal tubular cells.

    McGoldrick, Trevor A; Lock, Edward A; Rodilla, Vicente; Hawksworth, Gabrielle M


    Proximal tubular cells from human (HPT) and rat (RPT) kidneys were isolated, grown to confluence and incubated with S-(1,2-dichlorovinyl)- l-cysteine (DCVC), S-(1,2,2-trichlorovinyl)- l-cysteine (TCVC), S-(1,1,2,2-tetrafluoroethyl)- l-cysteine (TFEC) and S-(2-chloro-1,1-difluorethyl)- l-cysteine (CDFEC), the cysteine conjugates of nephrotoxicants. The cultures were exposed to the conjugates for 12, 24 and 48 h and the toxicity determined using the MTT assay. All four conjugates caused dose-dependent toxicity to RPT cells over the range 50-1,000 microM, the order of toxicity being DCVC>TCVC>TFEC=CDFEC. The inclusion of aminooxyacetic acid (AOAA; 250 microM), an inhibitor of pyridoxal phosphate-dependent enzymes such as C-S lyase, afforded protection, indicating that C-S lyase has a role in the bioactivation of these conjugates. In HPT cultures only DCVC caused significant time- and dose-dependent toxicity. Exposure to DCVC (500 microM) for 48 h decreased cell viability to 7% of control cell values, whereas co-incubation of DCVC (500 microM) with AOAA (250 microM) resulted in cell viability of 71%. Human cultures were also exposed to S-(1,2-dichlorovinyl)-glutathione (DCVG). DCVG was toxic to HPT cells, but the onset of toxicity was delayed compared with the corresponding cysteine conjugate. AOAA afforded almost complete protection from DCVG toxicity. Acivicin (250 microM), an inhibitor of gamma-glutamyl transferase (gamma-GT), partially protected against DCVG (500 microM)-induced toxicity at 48 h (5% viability and 53% viability in the absence and presence of acivicin, respectively). These results suggest that DCVG requires processing by gamma-GT prior to bioactivation by C-S lyase in HPT cells. The activity of C-S lyase, using TFEC as a substrate, and glutamine transaminase K (GTK) was measured in rat and human cells with time in culture. C-S lyase activity in RPT and HPT cells decreased to approximately 30% of fresh cell values by the time the cells reached

  3. 温度对大掺量粉煤灰水泥水化C-S-H聚合度的影响%Effect of Temperature on Aggregate States of Hydration Products C-S-H Gel of Cement with High Content of Fly Ash

    于文金; 罗永传; 弓子成; 丁庆军


    Effect of curing temperature and temperature variation on silicon-oxy tetrahedron aggregate states of hydra-tion products C-S-H gel of cement with high content of fly ash materials by high-resolution solid "Si NMR,XRD and FT-IR testing techniques. The results show that silicon-oxy tetrahedron aggregate states C-S-H gel and contents of alumi-num-oxy tetrahedron increased and then stabilized with the increase of curing temperature. Curing at normal temperature was good for increasing silicon-oxy tetrahedron aggregate states of CSH gels and contents of aluminum-oxy tetrahedron at the periods from 7 d to 28 d.%采用固体29Si核磁共振、FTIR、XRD测试方法研究了养护温度、温度变化对大掺量粉煤灰水泥基材料水化C-S-H凝胶硅氧四面体聚合程度的影响规律.结果表明:粉煤灰掺量为50%时,C-S-H凝胶硅氧四面体的聚合程度和C-S-H凝胶中铝氧四面体的比例随着养护温度的升高而呈现先增加后稳定的趋势.在7d至28 d龄期阶段,常温养护更加有利于C-S-H凝胶硅氧四面体聚合程度的增加,也更有利于Al原子取代Si原子.

  4. Zur Geschichte der Geowissenschaften im Museum für Naturkunde zu Berlin. Teil 3: Von A. G. Werner und R. J. Haüy zu C. S. Weiss – Der Weg von C. S. Weiss zum Direktor des Mineralogischen Museums der Berliner Universität

    G. Hoppe


    Der Berufung von C. S. Weiss an die Universität Berlin im Jahre 1810 gingen Entwicklungen voraus, die durch die Kristallographie des Franzosen R. J. Haüy, besonders durch dessen Lehrbuch der Mineralogie, ausgelöst wurden. Sie stehen mit der Übersetzung dieses Lehrbuchs im Zusammenhang und führten zur Qualifizierung von C. S. Weiss zum Mineralogen und Kristallographen sowie zur weiteren Entwicklung der Kristallographie innerhalb des Lehrgebäudes der Mineralogie. Den Anstoß gab der mit dem Berl...

  5. Ecología de los tursiones, Tursiops truncatus, en la Bahía de La Paz, B.C.S.

    Salinas Zacarías, Mario Alberto


    Se realizaron observaciones directas y fotoidentificación de los tursiones de la Bahía de La Paz, B.C.S. durante 2000 y 2001. Se determinó la distribución, abundancia relativa y su variación en relación con diversos factores ambientales. De la misma forma se determinó la estructura de la comunidad de tursiones en la bahía, las asociaciones entre grupos y el uso del ambiente en relación con su actividad reproductiva y alimentación. Así mismo se documentaron los desplazamientos de algunos de lo...

  6. Producción de A.C.S. y climatización de una vivienda unifamiliar con energía geotérmica

    Martínez Doce, Rubén


    El objetivo de este proyecto fin de carrera es el de realizar un diseño de una instalación para la producción de agua caliente sanitaria (A.C.S.), climatización de las estancias y de una piscina cubierta, de una vivienda unifamiliar mediante energía geotérmica, con el fin de proporcionar un ahorro energético utilizando una energía limpia. Ingeniería Industrial Industria Ingeniaritza

  7. Surface structure determination of group 11 metals adsorbed on a rhenium(10 anti 10) surface by low-energy electron diffraction

    Messahel, Lyria


    This thesis deals with the computational surface determination of various long-range ordered phases formed by thin films of copper, silver, and gold adsorbed on the rhenium- (10 anti 10) surface. It is based upon LEED-I,V curves for these phases that were recorded in the course of detailed experimental investigations of the respective films carried out in our group (using techniques such as LEED, MEED, and TPD). In order to solve the intricate puzzle of surface structural analysis, the electron elastic scattering behaviour of the investigated coinage metal phases was calculated using the Erlangen TensErLEED program package. Thereby first a set of theoretical LEED-I,V curves is derived for a guessed reference structure. Subsequently its structural input parameters are varied in a trial-and-error procedure until optimal agreement between experiment and theory is attained. The (1 x 1) phases formed by the deposited metals were tackled first to establish an absolute coverage calibration and to elucidate the respective growth modes on the Re(10 anti 10) surface. In all three cases the (1 x 1) structure is developed best at a coverage {Theta}{sub Cu,Ag,Au}=2 ML=1 BL. Extension of the investigation to experimental I,V curves for higher Cu coverages revealed that this element continues to grow bilayerwise, thereby retaining the Re hcp morphology. Ag, in contrast to Cu and Au, happens not to grow as homogeneously, and the TPD data suggest that Ag films exhibit the so-called simultaneous-multilayer (SM) growth mode. The following analysis of the sub-bilayer coverage range shows that the three systems exhibit considerable differences. While Cu, having a negative lattice misfit compared to Re, shows no long-range ordered superstructures, Ag and Au with a similar positive misfit form a couple of such phases. Ag features both a (1 x 4) phase, stable at ambient temperatures, that upon heating transforms into a c(2 x 2) phase that only exists at elevated temperatures. The

  8. 电感耦合等离子体质谱法测定钼矿石和钼精矿中铼%Determination of rhenium in molybdenum ores and molybdenum concentrate by inductively coupled plasma mass spectrometry

    程秀花; 黎卫亮


    采用氧化镁焙烧样品,热水浸提后不需分离富集,电感耦合等离子体质谱法直接测定钼矿石及钼精矿中铼.对不同焙烧熔剂、焙烧条件、浸提条件以及仪器测定条件进行了研究,结果表明:以氧化镁为焙烧试剂,在650℃保温90 min,趁热用热水浸提为最佳溶样条件,测定时选用103 Rh为内标元素,可有效校正仪器漂移,减小基体效应的干扰.方法检出限为0.005 μg/g,回收率在94%~102%之间.本方法经国家标准物质分析验证,结果与认定值吻合,相对标准偏差(RSD,n=5)≤3.6%,适合钼矿石及钼精矿中含量为0.05~300 μg/g铼的测定.%Molybdenum ore and molybdenum concentrate were calcined by magnesium oxide. After hot water extraction,the sample was directly determined by inductively coupled plasma mass spectrometry to obtain the content of rhenium. A study was conducted on the calcination solvent & conditions,extraction conditions and instrumental determination conditions. Results indicated that: magnesium oxide was taken as calcination solvent; the sample was kept at 650 °C for 90 min; the optimal dissolution conditions was to use hot water for leaching; 103Rh was selected as internal element to effectively correct instrumental drift and reduce the interference of matrix effect. The detection limit was 0. 005 μg/g and recoveries were between 94 % and 102 %. The method was tested by certified reference materials with the result consistent with certified value and RSD (n = 5) ≤ 3. 6 %. The method is suitable for the determination of rhenium with the content of 0. 05 ~ 300 μg/g in molybdenum ore and molybdenum concentrate.

  9. Early Permian extensional shearing of an Ordovician granite: The Saint-Eutrope "C/S-like" orthogneiss (Montagne Noire, French Massif Central)

    Pitra, Pavel; Poujol, Marc; Van Den Driessche, Jean; Poilvet, Jean-Charles; Paquette, Jean-Louis


    Dating the magmatic events in the Montagne Noire gneiss dome is a key point to arbitrate between the different interpretations of the Late Carboniferous-Early Permian tectonics in this southern part of the Variscan belt. The Saint-Eutrope orthogneiss crops out along the northern flank of the dome. We show that the protolith of this orthogneiss is an Ordovician granite dated at 455 ± 2 Ma (LA-ICP-MS U-Pb dating on zircon). This age is identical to that previously obtained on the augen orthogneiss of the southern flank, strongly suggesting that both orthogneiss occurrences have the same Ordovician protolith. The Saint-Eutrope orthogneiss experienced intense shearing along the Espinouse extensional detachment at ca. 295 Ma (LA-ICP-MS U-Pb-Th on monazite), an age close to that determined previously on mica by the 39Ar-40Ar method and contemporaneous with the emplacement age of the syntectonic Montalet granite farther to the west. This normal sense shearing reworked previous fabrics related to Variscan thrusting that can be still observed in the augen orthogneiss of the southern flank, and is responsible for the spectacular "C/S-like" pattern of the Saint-Eutrope orthogneiss. This work also shows that care is needed when dealing with C/S-type structures, since they can develop not only in syntectonic intrusions, but also in orthogneisses affected by an intense secondary deformation, at decreasing temperature.

  10. Occurrence of S and F1C/S-related fimbrial determinants and their expression in Escherichia coli strains isolated from extraintestinal infections.

    Sokolowska-Köhler, W; Schönian, G; Bollmann, R; Schubert, A; Parschau, J; Seeberg, A; Presber, W


    The presence of S and F1C/S-related fimbrial determinants was determined in 462 E. coli strains obtained from different extraintestinal infections and in 162 control isolates of E. coli by using two different DNA probes: an oligonucleotide probe consisting of three oligonucleotides that bind specifically to the S adhesin gene and a polynucleotide probe which is not able to distinguish between S, F1C, and S-related sequences. The expression of S and F1C phenotypes was tested by dot enzyme immunoassay with the corresponding monoclonal antibodies. S fimbriae genotypes were observed more frequently in septic (25%) and urinary (12%) isolates of E. coli than in faecal and water isolates (1%) and often occurred together with O2, O6, O18 and O83 antigens. F1C/S-related fimbrial DNA was detected with a higher frequency in UTI isolates (26%) than in septic (16%) and faecal (10%) isolates and was most frequently associated with O4, O6, and O75 serotypes. Since the production of S and F1C fimbriae was comparatively rare in all clinical and control isolates of E. coli, DNA hybridization assays which allow the sensitive and specific detection of fimbrial determinants even in the absence of their expression are preferable to phenotypic assays.

  11. The Styles of Software System Architecture--from C/S to B/S%软件体系结构风格--从C/S到B/S




  12. Effects of carbon-to-sulfur (C/S) ratio and nitrate (N) dosage on Denitrifying Sulfur cycle-associated Enhanced Biological Phosphorus Removal (DS-EBPR)

    Yu, Mei; Lu, Hui; Wu, Di; Zhao, Qing; Meng, Fangang; Wang, Yudan; Hao, Xiaodi; Chen, Guang-Hao


    In this study, the Denitrifying Sulfur cycle-associated Enhanced Biological Phosphorous Removal (DS-EBPR) with 20 mg P/L/d of the volumetric P removal rate was successfully achieved in a Sequencing Batch Reactor (SBR). The effects of carbon-to-sulfur (C/S) mass ratio and nitrate (N) dosage were investigated through two batch tests to reveal the role of wastewater compositions in DS-EBPR performance. The optimal specific P release and uptake rates (0.4 and 2.4 mg P/g VSS/h, respectively) were achieved at C/S/P/N mass ratio of 150/200/20/20, and poly-S is supplied as a potential electron and energy storage. The nitrate dosage in a range of 10-50 mg N/L had no significant influence on P uptake rates (2.1 ~ 2.4 mg P/g VSS/h), but significantly affected the storage of inclusion poly-S, the poly-S oxidation rate was increased about 16% while dosing nitrate from 20 to 30 mg N/L. It implies that nitrate is denitrified in the P uptake phase, and excess nitrate is further consumed by poly-S. Moreover, the microbial analysis showed that the functional bacteria should mostly belong to denitrifying bacteria or Unclassified genera.

  13. Oxidative Cleavage of C=S and P=S Bonds at an Al(I) Center: Preparation of Terminally Bound Aluminum Sulfides.

    Chu, Terry; Vyboishchikov, Sergei F; Gabidullin, Bulat; Nikonov, Georgii I


    The treatment of cyclic thioureas with the aluminum(I) compound NacNacAl (1; NacNac=[ArNC(Me)CHC(Me)NAr](-) , Ar=2,6-Pr(i)2 C6 H3 ) resulted in oxidative cleavage of the C=S bond and the formation of 3 and 5, the first monomeric aluminum complexes with an Al=S double bond stabilized by N-heterocyclic carbenes. Compound 1 also reacted with triphenylphosphine sulfide in a similar manner, which resulted in cleavage of the P=S bond and production of the adduct [NacNacAl=S(S=PPh3 )] (8). The Al=S double bond in 3 can react with phenyl isothiocyanate to furnish the cycloaddition product 9 and zwitterion 10 as a result of coupling between the liberated carbene and PhN=C=S. All novel complexes were characterized by multinuclear NMR spectroscopy, and the structures of 5, 9, and 10 were confirmed by X-ray diffraction analysis. The nature of the Al=S bond in 5 was also probed by DFT calculations.

  14. To Think and Watch the Evil: The Turn of the Screw as Cultural Reference in Television from Dark Shadows to C.S.I.

    Anna Viola Sborgi


    Full Text Available Since its first publication, Henry James’s The Turn of the Screw (1898 has always haunted the imagination of artists (Benjamin Britten, Jack Clayton, Amenábar and has been widely used as a source for television narratives (Dan Curtis, US TV version starring Colin Firth, Tim Fywell. In serial productions, James’s story has been the object of extensive quotation and allusion, from the 1960 gothic soap opera Dark Shadows to the C.S.I. episode Turn of the Screw (Season 4, Episode 21. A milestone in literary history, the story now embodies a set of cultural references conveying different, complex meanings, which can only be disclosed in the light of contemporary forms of representing reality. The novella appeals to two apparently opposite tendencies in contemporary television: the morbid display of the real (C.S.I. and the quest for the supernatural (Buffy The Vampire Slayer, among others. A line can be traced from Dark Shadows, the show that pioneered the genre, to contemporary horror soaps about vampires and supernatural phenomena. This paper shows the ways in which James’ sophisticated novella makes its way through popular culture, and how its constant ambiguous, dilemmatic interplay between reality and imagination can be related to the double-sided drive of the contemporary public towards hyper-reality and the supernatural.

  15. Role of support nature (γ-Al2O3 and SiO2-Al2O3) on the performances of rhenium oxide catalysts in the metathesis of ethylene and 2-pentene

    Weena Phongsawat; Benjamas Netiworaruksa; Kongkiat Suriye; Siraprapha Dokjampa; Piyasan Praserthdam; Joongjai Panpranot


    The metathesis of ethylene and 2-pentene was studied as an alternative route for propylene production over Re2O7/γ-Al2O3 and Re2O7/SiO2-Al2O3 catalysts.Both NH3 temperature-programmed desorption (NH3-TPD) and H2 temperature-programmed reduction (H2-TPR) results showed that Re2O7/SiO2-Al2O3 exhibited stronger acidity and weaker metal-support interaction than Re2O7/γ-Al2O3.At 35-60 ℃,isomerization free metathesis was observed only over Re2O7/γ-Al2O3,suggesting that the formation of metal-carbene metathesis active sites required only weak acidity.Our results suggest that on the Re2O7/SiO2-Al2O3,hydrido-rhenium species ([Re]-H) were formed in addition to the metathesis active sites,resulting in the isomerization of the initial 1-butene product into 2-butenes.A subsequent secondary metathesis reaction between these 2-butenes and the excess ethylene could explain the enhanced yields of propylene observed.The results demonstrate the potential for high yield of propylene from alternative feedstocks.

  16. Simultaneous determination of the Cd and Zn total body burden of individual, nearly microscopic, nanoliter-volume aquatic organisms (Hyalella azteca) by rhenium-cup in-torch vaporization (ITV) sample introduction and axially viewed ICP-AES

    Smith, Andrea T.; Badiei, Hamid R.; Karanassios, Vassili [University of Waterloo, Department of Chemistry, Waterloo, ON (Canada); Evans, J. Catherine [University of Waterloo, Department of Biology, Waterloo, ON (Canada)


    The Cd and Zn total body burden of individual, up to 7-day-old aquatic organisms (Hyalella aztecabenthic amphipod) with an average volume of approximately 100 nL was determined simultaneously by using rhenium-cup (Re-cup) in-torch vaporization (ITV) sample introduction and an axially viewed inductively coupled plasma atomic emission spectrometry (ICP-AES) system. The direct elemental analysis capabilities of this system (i.e., no sample digestion) reduced sample preparation time, eliminated contamination concerns from the digestion reagent and, owing to its detection limits (e.g., in the low pg range for Cd and Zn), vit enabled simultaneous determinations of Cd and Zn in individual, neonate and young juvenile specimens barely visible to the unaided eye (e.g., nearly microscopic). As for calibration, liquid standards and the standard additions method were tested. Both methods gave comparable results, thus indicating that in this case liquid standards can be employed for calibration, and in the process making use of the standard additions method unnecessary. Overall, the ITV-ICP-AES approach by-passed the time-consuming acid digestions, eliminated the potential for contamination from the digestion reagents, improved considerably the speed of acquisition of analytical information and enabled simultaneous determinations of two elements using individual biological specimens. (orig.)

  17. Reduced-Intensity Conditioning Combined with (188)Rhenium Radioimmunotherapy before Allogeneic Hematopoietic Stem Cell Transplantation in Elderly Patients with Acute Myeloid Leukemia: The Role of In Vivo T Cell Depletion.

    Schneider, Sebastian; Strumpf, Annette; Schetelig, Johannes; Wunderlich, Gerd; Ehninger, Gerhard; Kotzerke, Jörg; Bornhäuser, Martin


    The combination of reduced-intensity conditioning, (188)rhenium anti-CD66 radioimmunotherapy, and in vivo T cell depletion was successfully applied in elderly patients with acute myeloid leukemia or myelodysplastic syndrome. Within a prospective phase II protocol, we investigated whether a dose reduction of alemtuzumab (from 75 mg to 50 mg MabCampath) would improve leukemia-free survival by reducing the incidence of relapse. Fifty-eight patients (median age, 67 years; range, 54 to 76) received radioimmunotherapy followed by fludarabine 150 mg/m(2) and busulfan 8 mg/kg combined with either 75 mg (n = 26) or 50 mg (n = 32) alemtuzumab. Although we observed a trend towards a shorter duration of neutropenia in the 50 mg group (median, 19 versus 21 days; P = .07), the time from transplantation to neutrophil and platelet engraftment as well as the overall incidence of engraftment did not differ. The incidence of severe acute graft-versus-host disease tended to be higher after the lower alemtuzumab dose (17% versus 4%; P = .15). No significant differences in the cumulative incidences of relapse (38% versus 35%; P = .81) or nonrelapse mortality (46% versus 27%; P = .31) were observed. Accordingly, disease-free and overall survival were not significantly different between groups. Although the feasibility of radioimmunotherapy plus reduced-intensity conditioning could be demonstrated in elderly patients, the dose reduction of alemtuzumab had no positive impact on overall outcome.

  18. Crystal structure of octa-μ3-selenido-(p-toluene-sulfonato-κO)penta-kis-(tri-ethyl-phosphane-κP)-octa-hedro-hexa-rhenium(III) p-toluene-sulfonate di-chloro-methane disolvate.

    Edwards, Julia A; McDonald, Robert; Szczepura, Lisa F


    The title compound, [Re6Se8{O3SC6H4(CH3)}{P(C2H5)3}5](CH3C6H4SO3)·2CH2Cl2, contains the face-capped hexa-nuclear [Re6(μ3-Se)8](2+) cluster core. The [Re6Se8](2+) cluster core displays a non-crystallographic center of symmetry and is bonded through the Re(III) atoms to five tri-ethyl-phosphane ligands and one p-toluene-sulfonate ligand. One p-toluene-sulfonate counter-ion and two di-chloro-methane solvent mol-ecules are also present in the asymmetric unit. One of the ethyl chains of one triethylphos-phane ligand and one of the CH2Cl2 solvent molecules are disordered over two sets of sites (occupancy ratios 0.65:0.35 and 0.5:0.5, respectively). The Re-O(sulfon-ate) bond length of 2.123 (5) Å is similar to other Re-O bond lengths of hexa-nuclear rhenium chalcogenide clusters containing other O-donor ligands such as dimethyl sulfoxide (DMSO), di-methyl-formamide (DMF) and hydroxide.

  19. EDTA-Reduction of Water to Molecular Hydrogen Catalyzed by Visible-Light-Response TiO2-Based Materials Sensitized by Dawson- and Keggin-Type Rhenium(V-Containing Polyoxotungstates

    Yusuke Kataoka


    Full Text Available The synthesis and characterization of a Keggin-type mono-rhenium(V-substituted polyoxotungstate are described. The dimethylammonium salt [Me2NH2]4[PW11ReVO40] was obtained as analytically pure homogeneous black-purple crystals by reacting mono-lacunary Keggin polyoxotungstate with [ReIVCl6]2- in water, followed by crystallization from acetone at ca. 5 °C. Single-crystal X-ray structural analysis of [PW11ReVO40]4- revealed a monomeric structure with overall Td symmetry. Characterization of [Me2NH2]4[PW11ReVO40] was also accomplished by elemental analysis, magnetic susceptibility, TG/DTA, FTIR, UV-vis, diffuse reflectance (DR UV-vis, and solution 31P-NMR spectroscopy. Furthermore, [PW11ReVO40]4- and the Dawson-type dirhenium(V-oxido-bridged polyoxotungstate [O{ReV(OH(α2-P2W17O61}2]14- were supported onto anatase TiO2 surface by the precipitation methods using CsCl and Pt(NH34Cl2. With these materials, hydrogen evolution from water in the presence of EDTA⋅2Na (ethylenediamine tetraacetic acid disodium salt under visible light irradiation (≥400 nm was achieved.

  20. Synthesis of Bioactive 2-(Arylaminothiazolo[5,4-f]-quinazolin-9-ones via the Hügershoff Reaction or Cu- Catalyzed Intramolecular C-S Bond Formation

    Damien Hédou


    Full Text Available A library of thirty eight novel thiazolo[5,4-f]quinazolin-9(8H-one derivatives (series 8, 10, 14 and 17 was prepared via the Hügershoff reaction and a Cu catalyzed intramolecular C-S bond formation, helped by microwave-assisted technology when required. The efficient multistep synthesis of the key 6-amino-3-cyclopropylquinazolin-4(3H-one (3 has been reinvestigated and performed on a multigram scale from the starting 5-nitroanthranilic acid. The inhibitory potency of the final products was evaluated against five kinases involved in Alzheimer’s disease and showed that some molecules of the 17 series described in this paper are particularly promising for the development of novel multi-target inhibitors of kinases.

  1. Volatile compounds of sulfur in the Fe-C-S system at 5.3 GPa and 1300°C

    Zhimulev, E. I.; Sonin, V. M.; Bul'bak, T. A.; Chepurov, A. I.; Tomilenko, A. A.; Pokhilenko, N. P.


    This report presents the results of experimental studies of the fluid phase in the Fe-C-S system at high P and T values (5.3 GPa and 1300°C) conforming to diamond synthesis. The samples for experiments were mounted on air; therefore, the volatile compounds detected after the experiments are characterized by a wide variety and complicated composition involving both inorganic and organic components. Among the inorganic compounds, CO2, H2O, N2, SO2, CS2, and COS were detected. The GC/MS analysis revealed hydrocarbons (paraffins, olefins, and arenes), including high-molecular compounds. The formation of heavy hydrocarbons confirms their thermodynamic stability under high pressure. Oxygenated hydrocarbons (alcohols, aldehydes, ketones, carboxylic acids, and ethers) were also detected.

  2. Una (revisión del mito y de lo imaginario desde la semiótica de C.S. Peirce

    Fernando Torres Andacht


    Full Text Available El trabajo busca presentar un cruce teórico posible y fructífero entre el modelo semiótico triádico elaborado por C.S. Peirce y algunas nociones claves de las ciencias sociales, tal como fueron expuestas por algunos de sus primeros pensadores (Durkheim, Sorel y también de sus continuadores modernos (Anderson, Kolakowski. En torno al concepto de mito, de ritual y de imaginario, es posible establecer un diálogo con los elementos básicos de la semiótica peirceana. El propósito que anima esta reflexión es más el de señalar un camino futuro que el de presentar una tesis sobre cómo podría ser la confluencia de las ciencias sociales y la semiótica de tipo triádico.

  3. Synergistic Effect between the Atomically Dispersed Active Site of Fe-N-C and C-S-C for ORR in Acidic Medium.

    Shen, Hangjia; Gracia-Espino, Eduardo; Ma, Jingyuan; Zang, Ketao; Luo, Jun; Wang, Le; Gao, Sanshuang; Mamat, Xamxikamar; Hu, Guangzhi; Wagberg, Thomas; Guo, Shaojun


    Various advanced catalysts of sulfur doped Fe-N-C materials have been recently designed for oxygen reduction reaction (ORR), however, the enhanced activity is still controversial and usually attributed to differences in surface area, improved conductivity, or to uncertain synergistic effects. Here, a sulfur-doped Fe-N-C catalyst (denoted as Fe/SNC) derived via a template sacrificing method is presented. The incorporated S gives a thiophene-like structure (C-S-C), reduces the electron localization around the Fe center, improves the interaction with oxygenated species, and therefore facilitates the complete 4e- ORR in acid solution. This synergistic effect makes the Fe/SNC catalyst exhibits much better ORR activity than sulfur free catalyst (Fe/NC) in 0.5 M H2SO4. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Role of active-site residues Tyr55 and Tyr114 in catalysis and substrate specificity of Corynebacterium diphtheriae C-S lyase.

    Astegno, Alessandra; Allegrini, Alessandra; Piccoli, Stefano; Giorgetti, Alejandro; Dominici, Paola


    In recent years, there has been increased interest in bacterial methionine biosynthesis enzymes as antimicrobial targets because of their pivotal role in cell metabolism. C-S lyase from Corynebacterium diphtheriae is a pyridoxal 5'-phosphate-dependent enzyme in the transsulfuration pathway that catalyzes the α,β-elimination of sulfur-containing amino acids, such as L-cystathionine, to generate ammonia, pyruvate, and homocysteine, the immediate precursor of L-methionine. In order to gain deeper insight into the functional and dynamic properties of the enzyme, mutants of two highly conserved active-site residues, Y55F and Y114F, were characterized by UV-visible absorbance, fluorescence, and CD spectroscopy in the absence and presence of substrates and substrate analogs, as well as by steady-state kinetic studies. Substitution of Tyr55 with Phe apparently causes a 130-fold decrease in K(d)(PLP) at pH 8.5 providing evidence that Tyr55 plays a role in cofactor binding. Moreover, spectral data show that the mutant accumulates the external aldimine intermediate suggesting that the absence of interaction between the hydroxyl moiety and PLP-binding residue Lys222 causes a decrease in the rate of substrate deprotonation. Mutation of Tyr114 with Phe slightly influences hydrolysis of L-cystathionine, and causes a change in substrate specificity towards L-serine and O-acetyl-L-serine compared to the wild type enzyme. These findings, together with computational data, provide useful insights in the substrate specificity of C-S lyase, which seems to be regulated by active-site architecture and by the specific conformation in which substrates are bound, and will aid in development of inhibitors.

  5. Mechanistic Insight into the Cu-Catalyzed C-S Cross-Coupling of Thioacetate with Aryl Halides. A Joint Experimental-Computational Study.

    Soria-Castro, Silvia M; Andrada, Diego M; Caminos, Daniel A; Argúello, Juan E; Robert, Marc; Peñeñory, Alicia B


    The mechanism of the Ullmann-type reaction between potassium thioacetate (KSAc) and iodobenzene (PhI) catalyzed by CuI associated with 1,10-phenanthroline (phen) as a ligand has been explored experimentally and computationally. The study on C-S bond formation has been investigated by UV-visible spectrophotometry, cyclic voltammetry, mass espectrometry and products assessment from radical probes. The results indicate that under experimental conditions the catalytically active species is [Cu(phen)(SAc)] regardless of the copper source. An examination of the aryl halide activation mechanism using radical probes was undertaken. No evidences of the presence of radical species have been found during the reaction process, which is consistent with an oxidative addition cross coupling pathway. The different reaction pathways leading to the experimentally observed reaction products have been studied by DFT calculation. The oxidative addition - reductive elimination mechanism via an unstable CuIII intermediate is energetically more feasible than other possible mechanisms such as Single Electron Transfer, Halogen Atom Transfer and σ-Bond Methatesis.

  6. Synthesis of [{sup 11}C]-S21007 a novel 5HT{sub 3} partial agonist as a potential tracer for PET studies

    Guillouet, S.; Barre, L.; Gourand, F. [CEA Centre de Cyceron, 14 -Caen (France); Lasne, M.C. [Centre National de la Recherche Scientifique, 14 - Caen (France); Rault, S. [Caen Univ., 14 (France). Faculte de Pharmacie


    5HT{sub 3} receptors have been the focus of much research during the last decade. The presence of these receptors has been demonstrated in many neuronal tissues, both in periphery and in the CNS. The identification of selective agonists and antagonists for this receptor subtype has allowed the discovery of several important new therapeutic applications as the inhibition of pain, migraine, cytotoxic and radiation-induced emesis and treatment of psychoses and anxiety. The first 5HT{sub 3} antagonist labelled with a {beta}+ emitter atom was [{sup 11}C]MDL72222. The PET studies which have been performed with it in the brain of baboon (distribution, kinetics and binding) have established that it was not a good radioligand to detect a specific binding, due to its high lipophilicity. Other radioligands have been developed since, but their affinities for 5HT{sub 3} receptors PET studies have not been demonstrated. Among a series of of tricyclic piperazine derivatives synthesized, S21007 has been described as a novel selective and partial agonist which possesses a good affinity for 5HT{sub 3} receptors (IC{sub 50} = 1nM) versus other 5HT subtypes studied where IC{sub 50} > 1{mu}M. We report here the radiosynthesis of [{sup 11}C]S21007. (author).

  7. A Quick Study of Science Return from Direct Imaging Exoplanet Missions: Detection and Characterization of Circumstellar Material with an AFTA or EXO-C/S CGI

    Schneider, Glenn


    The capabilities of a high (~ 10^-9 resel^-1) contrast, narrow-field, coronagraphic instrument (CGI) on a space-based AFTA-C or probe-class EXO-C/S mission, conceived to study the diversity of exoplanets now known to exist into stellar habitable zones, are particularly and importantly germane to symbiotic studies of the systems of circumstellar (CS) material from which planets have emerged and interact with throughout their lifetimes. The small particle populations in "disks" of co-orbiting materials can trace the presence of planets through dynamical interactions that perturb the spatial distribution of the light-scattering debris, detectable at optical wavelengths and resolvable with an AFTA-C or EXO-S/C CGI. Herein we: (1) present the science case to study the formation, evolution, architectures, diversity, and properties of the material in the planet-hosting regions of nearby stars, (2) discuss how a CGI under current conception can uniquely inform and contribute to those investigations, (3) consider the ...

  8. 无纸化考试系统的设计与实现%The Design and Implement for Paperless Examination System on C/S



    The needs analysis,overall design,the detailed design and the backend database of Paperless examination system are introduced.To uses the technology in visual stutio 2005 and SQL(Structured Query Language)database to design and implement the Paperless examination system based on C/S.The automatic grading and maintenance mode of the exam papers in the back-end management system,as well as the establishment of backend database and data maintenance are focused on the paper.%通过对无纸化考试系统的需求分析、总体设计和详细的设计过程以及后台数据库的描述,利用VS 2005和SQL 2000数据库技术设计实现了基于C/S模式的无纸化考试系统.重点分析了前台考试系统中的试题自动评分模块和后台管理系统中的试题维护模块,以及后台数据库的建立、数据维护等功能.

  9. Synthesis of 1,2,4-Triazoles via Oxidative Heterocyclization: Selective C-N Bond Over C-S Bond Formation.

    Gogoi, Anupal; Guin, Srimanta; Rajamanickam, Suresh; Rout, Saroj Kumar; Patel, Bhisma K


    The higher propensity of C-N over C-S bond forming ability was demonstrated, through formal C-H functionalization during the construction of 4,5-disubstituted 1,2,4-triazole-3-thiones from arylidenearylthiosemicarbazides catalyzed by Cu(II). However, steric factors imparted by the o-disubstituted substrates tend to change the reaction path giving thiodiazole as the major or an exclusive product. Upon prolonging the reaction time, the in situ generated thiones are transformed to 4,5-disubstituted 1,2,4-triazoles via a desulfurization process. Two classes of heterocycles viz. 4,5-disubstituted 1,2,4-triazole-3-thiones and 4,5-disubstituted 1,2,4-triazoles can be synthesized from arylidenearylthiosemicarbazides by simply adjusting the reaction time. Desulfurization of 1,2,4-triazole-3-thiones is assisted by thiophilic Cu to provide 1,2,4-triazoles with concomitant formation of CuS and polynuclear sulfur anions as confirmed from scanning electron microscope and energy dispersive X-ray spectroscopy measurements. A one-pot synthesis of an antimicrobial compound has been successfully achieved following this strategy.

  10. Palabra creadora y visión poética del mundo. Los comienzos de la fantasía épica en C. S. Lewis

    Omar David Gutiérrez Bautista


    Full Text Available La enorme difusión de la serie de libros Las Crónicas de Narnia del autor británico C. S. Lewis, invita al estudio de la calidad artística de la obra que forma parte de los comienzos de la fantasía épica; no sólo porque representa un hito en la historia literaria, sino porque sigue siendo una expresión de necesidades humanas fundamentales que, si bien se ubicaron en la etapa de posguerra en el siglo XX, actualmente se observan en los grandes cuestionamientos de la posmodernidad. La crisis de los grandes relatos expresados generalmente por las religiones y la disolución cultural de grandes referentes literarios, producen un campo propicio para la aparición de obras literarias que, como Las Crónicas de Narnia, proponen una visión del mundo y un proyecto de futuro. En el presente trabajo analizaremos el valor artístico de El sobrino del mago (1955, libro con que se abre la colección de libros infantiles, como obra que propone una visión poética del mundo con el trasfondo religioso judeocristiano de la creación.

  11. Preliminary Study on the Use of Radionuclides 137{sup C}s and 210{sup P}b and Spectro radiometry Techniques as Tools to Determine Soil Erosion State; Estudio Preliminar sobre el Uso de los Radionucleidos 137{sup C}s y 210{sup P}b y las Tecnicas de Espectrorradiometria como Herramientas para Determinar el Estado de Erosion de Suelos

    Rodriguez Vegas, E.; Gasco Leonarte, C.; Schmid, T.; Suarez, J. A.; Rodriguez Rastrero, M.; Almorox Alonso, J.


    Radionuclides are largely used as tools for studying and quantifying soil erosion. The global fallout of artificial radionuclides derived from weapons testing (1945-1970) was rapidly and firmly fixed in soil surface horizons. This allowed determining soil erosion by comparing 137{sup C}s inventories at individual sampling points with a reference inventory. This procedure is complemented with the 210{sup P}buns inventory calculation as an indicator of the local average of radionuclides deposition. Spectro radiometry is implemented to associate soil reflectance measurements to physical and chemical soil properties related to soil erosion processes obtained from laboratory analyses. The methodology applies both instrumental techniques in soil samples from a semiarid agricultural area near to Camarena (Toledo). The resulting inventories obtained for 137{sup C}s and 210{sup P}bexc are similar to the Spanish reference allowing comparation. Spectro radiometry results correlate well with soil properties measured in the laboratory and can be applied to determine these properties more quickly and easily, as well as for integration with gamma spectrometry results. This is a preliminary study to identify soils affected by erosion that is presented as a Master thesis of the Official Master Degree: {sup A}gro- Environmental Technology for a Sustainable Agriculture{sup ,} of the Technical University of Madrid - School of Agricultural Engineers (UPM-ETSI). Coherent and complimentary results are obtained applying both instrumental techniques within this agricultural area.. (Author)

  12. Polarized and depolarized Raman spectra of liquid carbon disulfide in the pressure range 0-10 kbar. I. Vibration frequencies, C-S bond length, and Fermi resonance

    Ikawa, S.; Whalley, Edward


    The effect of pressure on the polarized and depolarized Raman spectra of liquid carbon disulphide, i.e., the peak frequencies, bandwidths, and relative intensities of both the allowed ν1 and 2ν2 bands and the interaction-induced ν2 and ν3 bands, have been measured at 22 °C up to 10 kbar. This paper discusses the effect of pressure on the frequencies and on the relative isotropic intensity of the ν1 and 2ν2 bands. The frequency of the ν1 band increases linearly with pressure, within the experimental uncertainty, at the rate 0.16±0.01 cm-1 kbar-1, and the frequencies of the ν2, ν3, and 2ν2 bands decrease nonlinearly. The frequency shifts are described by second-order perturbation theory with the molecular anharmonicity and the intermolecular interaction as perturbations. The leading terms of the shifts consist of the same derivative of the interaction potential, multiplied by different anharmonicity constants, and the shifts of the ν1 and 2ν2 bands suggests that the C-S bond length decreases at the rate 2×10-4 Å kbar-1. The relative isotropic intensity of the 2ν2 and ν1 bands increases with pressure at the rate 0.050 kbar-1, whereas the anisotropic 2ν2 intensity relative to the isotropic ν1 intensity is independent of pressure to the experimental precision of ˜0.005. The effect of pressure on the second derivative of the isotropic and anisotropic parts of the polarizability with respect to the bend coordinate was estimated as 1.1×10-43 C m2 V-1 kbar-1 and ˜0, respectively, from these values.

  13. The Representation of Biblical Archetypes in The Chronicles of Narnia and C.S.Lewis' Christian Thought on Children%《纳尼亚传奇》中的《圣经》原型再现与C.S.路易斯的基督教儿童观




  14. Comunicação simbólica em primatas não-humanos: uma análise baseada na semiótica de C. S. Peirce Symbol-based communication in non-human primates: a C. S. Peirce's semiotic analysis

    João Queiroz


    Full Text Available Existem (ou existiram outras espécies de criaturas simbólicas? Essa questão tem sido abordada por pesquisadores de diversas áreas e é responsável por uma histórica controvérsia sobre a existência de um limiar entre "criaturas simbólicas" vs "criaturas capazes de produzir formas simples de linguagem". Conforme o mainstream em Etologia e Psicologia Comparada apenas o Homo sapiens está cognitivamente equipado para produzir e interpretar símbolos. Vou introduzir um modelo empiricamente testável de semiose simbólica ("ação simbólica do signo", baseada na teoria das categorias lógico-fenomenológicas de C.S.Peirce. Vou sugerir que um padrão específico de comportamento do usuário do signo, observado na comunicação de primatas não-humanos, indica a transição de uma semiose indexical para uma simbólica.Are (or were there any other symbolic species? This question has been addressed by researchers from many different fields and is responsible for a historical controversy on the existence of a threshold between "symbolic creatures" vs "simple forms of language creatures". According to the mainstream ethology and comparative psychology only the Homo sapiens is cognitively equiped to produce and interpret symbols. Here, I introduce an empirically testable model of symbolic semiosis ("symbolic action of sign" supported by C.S.Peirce logical-phenomenological theory of categories. I suggest that a specific sign-user pattern of behavior, observed in non-human primate communication, indicate a transition from indexical to symbolic semiosis.

  15. Jargonial-Obfuscation(J-O) DISambiguation Elimination via Siegel-Baez Cognition Category-Semantics(C-S) in Siegel FUZZYICS=CATEGORYICS (Son of TRIZ)/(F=C) Tabular List-Format Dichotomy Truth-Table Matrix Analytics

    Siegel, Carl Ludwig; Siegel, Edward Carl-Ludwig


    NOT "philosophy" per se but raising serious salient Arnol'd [Huygens and Barrow, Newton and Hooke(96)] questions begged is Rota empiricism Husserl VS. Frege maths-objects Dichotomy controversy: Hill-Haddock[Husserl or Frege?(00)]as manifestly-demonstrated by Hintikka[B.U.]-Critchey[Derrida Deconstruction Ethics(78)] deconstruction; Altshuler TRIZ; Siegel F=C/C-S; Siegel-Baez(UCR) Cognition C-S = "Category-theory ``+'' Cognitive-Semantics[Wierzbica-Langacker-Lakoff-Nunez[Where Maths Comes From(00)]-Fauconnier-Turner[Blending(98)]-Coulson[Semantic-Leaps (00)

  16. Correlação entre a cistatina C sérica e marcadores de aterosclerose subclínica em pacientes hipertensos

    Francisco das Chagas Monteiro Junior


    Full Text Available FUNDAMENTO: A cistatina C sérica (s-CC, um marcador endógeno da função renal, tem sido proposta também como um marcador de risco cardiovascular. No entanto, ainda não está estabelecido se se trata de um marcador direto de aterosclerose, independentemente da função renal. OBJETIVO: O objetivo deste estudo foi correlacionar a s-CC com dois marcadores substitutos de aterosclerose subclínica. MÉTODOS: Trata-se de um estudo transversal envolvendo 103 pacientes hipertensos ambulatoriais, de meia idade (57,49 ± 11,7 anos, sendo 60 do sexo feminino (58,25% e a maioria com função renal preservada. A s-CC foi correlacionada com a espessura mediointimal carotídea (EMIc e a dilatação mediada por fluxo de artéria braquial (DMF, ambas avaliadas por ultrassonografia, bem como com o clearance de creatinina medido e fatores de risco cardiovascular estabelecidos. RESULTADOS: A s-CC não se correlacionou significativamente nem com a EMIc (r = -0,024, p = 0,84 nem com a DMF (r = -0,050 e p = 0,687, e não foi observada também associação significativa com fatores de risco convencionais nem marcadores inflamatórios. Na análise univariada, a s-CC se correlacionou com o clearance de creatinina medido (r = - 0,498, p < 0,001, idade (r = 0,408, p < 0,001, microalbuminúria (r = 0,291, p = 0,014, ácido úrico (r = 0,391, p < 0,001, relação E/e' (r = 0,242, p = 0,049 e escore de Framingham (r = 0,359, p = 0,001. No entanto, após análise de regressão múltipla, apenas a associação com o clearance de creatinina medido permaneceu significativa (r = -0,491, p <0,001. CONCLUSÃO: Em pacientes hipertensos ambulatoriais de meia idade, a s-CC se correlacionou com o clearance de creatinina medido,como esperado, mas não foi observada associação com marcadores de aterosclerose nem com fatores de risco cardiovascular estabelecidos.

  17. Computational modeling of the bHLH domain of the transcription factor TWIST1 and R118C, S144R and K145E mutants

    Maia Amanda M


    Full Text Available Abstract Background Human TWIST1 is a highly conserved member of the regulatory basic helix-loop-helix (bHLH transcription factors. TWIST1 forms homo- or heterodimers with E-box proteins, such as E2A (isoforms E12 and E47, MYOD and HAND2. Haploinsufficiency germ-line mutations of the twist1 gene in humans are the main cause of Saethre-Chotzen syndrome (SCS, which is characterized by limb abnormalities and premature fusion of cranial sutures. Because of the importance of TWIST1 in the regulation of embryonic development and its relationship with SCS, along with the lack of an experimentally solved 3D structure, we performed comparative modeling for the TWIST1 bHLH region arranged into wild-type homodimers and heterodimers with E47. In addition, three mutations that promote DNA binding failure (R118C, S144R and K145E were studied on the TWIST1 monomer. We also explored the behavior of the mutant forms in aqueous solution using molecular dynamics (MD simulations, focusing on the structural changes of the wild-type versus mutant dimers. Results The solvent-accessible surface area of the homodimers was smaller on wild-type dimers, which indicates that the cleft between the monomers remained more open on the mutant homodimers. RMSD and RMSF analyses indicated that mutated dimers presented values that were higher than those for the wild-type dimers. For a more careful investigation, the monomer was subdivided into four regions: basic, helix I, loop and helix II. The basic domain presented a higher flexibility in all of the parameters that were analyzed, and the mutant dimer basic domains presented values that were higher than the wild-type dimers. The essential dynamic analysis also indicated a higher collective motion for the basic domain. Conclusions Our results suggest the mutations studied turned the dimers into more unstable structures with a wider cleft, which may be a reason for the loss of DNA binding capacity observed for in vitro

  18. Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers

    Wellington, Kevin W


    Full Text Available Oxidative C-S and C-C bond formation with aryl and alkyl thiols was catalyzed under mild conditions in a reaction vessel open to air at pH 4.5 in the presence of a commercial laccase (Novozym 51003 or Suberase) and a cosolvent (DMF) to afford 1...

  19. Nuclear wastes management: the lessons from the C.S.M. disposal site (Centre de Stockage de la Manche). Memory-less Centre, Future-less Centre?; Gestion des dechets radioactifs: les lecons du Centre de Stockage de la Manche (C.S.M.). Centre Sans Memoire, Centre Sans Avenir?



    With its 527 217 m{sup 3} of low and medium activity wastes put in storage between 1969 and 1994, the C.S.M.( center of storage of Manche) is and remains to this day a necessary element to understand the problems posed by the eternal storage of nuclear materials and the limits of the notion of reversibility. There are therefore teachings to be drawn. We cannot repeat past mistakes in particular with high activity wastes which we wish to bury deep underground. This report is based on the analysis of the existing bibliography, of the internal A.N.D.R.A. documents which we released to the public, of the lessons drawn from our participation in the official concerting and work groups, and finally of the data obtained after inquiries were done in the region in the framework of R.I.V.I.E;R.E. (citizens network of radioecological surveillance, information and evaluation). In spite of all efforts produced, many questions remain unanswered regarding this site so it is sometimes difficult to be more precise. (N.C.)

  20. Development of novel strategy for the synthesis of organometallic compounds usable as protein ligands: application to the human cyclophilin hCyp-18; Developpement de ligands de proteines par assemblage combinatoire autour d'un coeur de rhenium{sup V}: application a la cyclophiline hCyp-18

    Clavaud, C


    This thesis describes a new strategy for the development of bioactive organometallic compounds, basing on the combinatorial assembly of sub-chemical libraries (A and B) independent but complementary and able to coordinate a metallic heart M to form A-M-B complex potential ligands of biomolecules. The coordination of metals, well adapted to the production of molecular variety is usually used in medicinal chemistry, in diagnostic and therapeutic nuclear medicine. Among the useful elements, the rhenium and the technetium are metals of choice for the development of the assembly strategy because of their chemical and radiochemical properties and of the structure analogy of their complexes. This strategy was validated in vitro. The protein chosen for this purpose was the cyclophilin hCyp-18. (N.C.)

  1. PENGGUNAAN SEPPAKS ALUMINA SEBAGAI ALAT UJI KUALITAS SISTEM GEL GENERATOR TUNGSTEN-188/RENIUM-188 (The Use of Alumina SepPaks As A Quality Control Tool for The Tungsten-188/Rhenium-188 Gel Generators System

    Duyeh Setiawan


    for decay of the 188Re daughter, the use of an alumina SepPaks in tandem with the 188W/188Re gel generator is an effective technique to trap the 188W breakthrough.  This technique was showed by experiment result gel generators 188W/188Re titan tungstate, the eluate was  subsequently passed through alumina SepPaks followed by thorough washing with 0.9 % pH 5.  The result of elution  is obtained maximum yield 65 %, it has radionuclide purities is 97 % and radiochemical is 95 %.  The scavenger determination of 188W was showed in the presence of 290 keV gamma spectrum in the alumina SepPaks were clearly detected. Based on the result its showed that, the use of alumina SepPaks was very effective as  a quality control tool in assessing  188W/188Re gel generator performance system for radionuclide rhenium-188 production.

  2. Kritický rozbor českých překladů románu od C. S. Lewise: The Chronicles of Narnia: The Lion, the Witch and the Wardrobe

    Bryndová, Barbora


    This MA thesis is concerned with the comparison of two Czech translations of C. S. Lewis' novel The Chronicles of Narnia: The Lion, the Witch and the Wardrobe. The thesis is divided into two parts: theoretical and practical. The first part concentrates on the description of the author's and translators' life as well as the background of creating the novel and its translations. One part deals with the film adaptations of the book. Then there are described individual techniques and methods of t...

  3. A triad of rhenium-mediated transformations

    Jaydip Gangopadhyay; Samir Das; Suman Sengupta; Indranil Chakraborty; Animesh Chakravorty


    The title transformations are oxygen atom transfer, twin isomerization and regiospecific imine oxidation. Bispyridyldiazole ligands have furnished new oxygen atom transfer reagents of coordination type ReVOCl3(NN) which undergo a slower transfer to PPh3 than the corresponding azole reagents. The rate of twin isomerization (linkage and geometrical) of meridional azole complexes of coordination type ReIII(OPnP)Cl3(NN) to facial ReIII(PnPO)Cl3(NN) decreases rapidly as increases in the interval 1-4 (PnP is Ph2P(CH2)PPh2). An -diimine chelate of type ReV(NPh)Cl3(NN) is shown to undergo facile oxidation to the corresponding iminoamide complex ReVI(NPh)Cl3(NN) upon treating with dilute nitric acid. The reaction proceeds via regiospecific nucleophilic addition of water to the more polarized imine function.

  4. An elusive vinyl radical isolated as an appended unit in a five-coordinate Co(iii)-bis(iminobenzosemiquinone) complex formed via ligand-centered C-S bond cleavage.

    Sarkar, Prasenjit; Tiwari, Archana; Sarmah, Amrit; Bhandary, Subhrajyoti; Roy, Ram Kinkar; Mukherjee, Chandan


    Redox-active ligand H4Pra(edt(AP/AP)) experienced C-S bond cleavage during complexation reaction with Co(OAc)2·2H2O in the presence of Et3N in CH3OH in air. Thus, formed complex 1 was composed of two iminobenzosemiquinone radicals in its coordination sphere and an unprecedented stable tethered-vinyl radical. The complex has been characterized by mass, X-ray single crystal, X-band EPR, variable-temperature magnetic moment measurements and DFT based computational study.

  5. Características ecofisiológicas de la reproducción de Nodipecten subnodosus (Sowerby, 1835) (Pectinidae) en la Laguna Ojo de Liebre, B.C.S.

    Arellano Martínez, Marcial


    El conocimiento de los ciclos de vida, de las estrategias reproductivas y de los factores que influyen sobre el proceso reproductivo de cualquier especie, son fundamentales para desarrollar programas de manejo sustentable de los recursos. En este estudio se analizó el proceso reproductivo de la almeja mano de león Nodipecten subnodosus en la laguna Ojo de Liebre, B.C.S., México, y su relación con el ciclo de almacenamiento y utilización de energía, así como la influencia de los factores ambie...

  6. Response of duplex Cr(N)/S and Cr(C)/S coatings on 316L stainless steel to tribocorrosion in 0.89% NaCl solution under plastic contact conditions.

    Sun, Y; Dearnley, P A; Mallia, Bertram


    Two duplex coatings, Cr(N)/S and Cr(C)/S, were deposited on 316 L stainless steel by magnetron sputtering. The effectiveness of these duplex coatings in improving the tribocorrosion behavior of medical alloys under elastic contact conditions has been demonstrated in a recent publication. The present work focused on the response of these duplex coatings to tribocorrosion under plastic contact conditions. Tribocorrosion tests were conducted in 0.89% NaCl solution at 37°C at an initial contact pressure of 740 MPa and under unidirectional sliding conditions for sliding duration up to 24 h. The results showed that during sliding in the corrosive solution, the duplex coatings were plastically deformed into the substrate to a depth about 1 μm. The Cr(C)/S duplex coating had sufficient ductility to accommodate the deformation without cracking, such that it was worn through gradually, leading to the gradual increase in open circuit potential (OCP) and coefficient of friction (COF). On the other hand, the Cr(N)/S duplex coating suffered from cracking at all tested potentials, leading to coating blistering after prolonged sliding at OCP and stable pit formation in the substrate beneath the coating at applied anodic potentials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  7. The C.S.R. implementation

    Mihaela Bucur


    Full Text Available The enterprises which started to integrate the principles of sustainable development in their activity, in their business processes and in their philosophy of business unfolding, require that Corporate Social Responsibility (CSR actions held by the companies involved a significant component of sustainable development. In practice, it would be beneficial if every direct action of the enterprise achieved long-lasting objectives and obtained sustainable results. The original contribution of this work is therefore essential for practitioners because it identifies a series of steps to be followed for the implementation and evaluation of a company's CSR activities. The present research addresses the need for implementing the concept of CSR in up companies. Our approach is drawn from several theoretical models, simplified for a beginner integrating CSR programs. Thus, in order to know what to start with, we have identified a number of simple steps and a methodology presented in this article.

  8. Rhetoric and Semiotic in C. S. Peirce.

    Lyne, John R.


    Outlines Peirce's philosophy of rhetoric by examining his philosophy of signs and sketching his specific program for rhetoric as a general art for "rendering signs effective." Suggests that Peirce's work is part of a fully elaborated system of inquiry and signification. (JMF)

  9. 非球面玻璃模造用碳化钨模仁磁控溅射铼-铱镀膜工艺优化%Optimization of magnetron sputtering of rhenium-iridium coating on mold core (tungsten carbide) used for aspheric glass molding



    通过钽过渡镀层与铼-铱复合镀层相结合的膜层结构,解决了非球面玻璃模造碳化钨模仁热压寿命短、沾黏等问题.通过离子源和镀膜层厚度参数的优化调整,得到了最佳镀膜工艺和参数,改善了模仁的表面品质,延长了模仁的使用寿命.镀钽膜层15 min及铼-铱膜层21 min后所得镀膜的总厚度约为270 nm,模仁热压寿命可超过3 000次.%The problems of short service life and sticking of tungsten carbide (WC) mold core used for aspheric glass molding were solved by combination of tantalum mediate coating and rhenium-indium composite coating. The parameters of ion source and coating thickness were optimized and the optimal plating conditions were obtained. The surface quality of mold core was improved and its service life greatly extended. The molding core with a coating having a total thickness of ca.270 nm obtained by successively plating Ta for 15 min and Re-Ir for 21 min can be reused for more than 3 000 times in hot embossing.

  10. Oxygen atom transfer reactions from dioxygen to phosphines via a bridging sulfur dioxide in a trinuclear cluster complex of rhenium, [(Ph(3)P)(2)N][Re(3)(mu(3)-S)(mu-S)(2)(mu-SO(2))Cl(6)(PMe(2)Ph)(3)].

    Saito, Taro; Sunaga, Tomoaki; Sakai, Nobuaki; Nakamura, Yoichi; Yamamoto, Saori; Iriuchijima, Daisuke; Yoza, Kenji


    A trinuclear rhenium sulfide cluster complex, [(Ph(3)P)(2)N][Re(3)(mu(3)-S)(mu-S)(3)Cl(6)(PMe(2)Ph)(3)], synthesized from Re(3)S(7)Cl(7), dimethylphenylphosphine, and [(Ph(3)P)(2)N]Cl is readily converted to a bridging SO(2) complex, [(Ph(3)P)(2)N][Re(3)(mu(3)-S)(mu-S)(2)(mu-SO(2))Cl(6)(PMe(2)Ph)(3)], by reaction with O(2). The oxygen atoms on the SO(2) ligand react with phosphines or phosphites to form phosphine oxides or phosphates, and the original cluster complex is recovered. The reaction course has been monitored by (31)P NMR as well as by UV-vis spectroscopy. The catalytic oxygenation of PMePh(2) in the presence of the SO(2) complex shows that turnovers are 8 per hour at 23 degrees C in CDCl(3). The X-ray structures of the cluster complexes are described.

  11. Effect of Ba2+on microstructure of C-S-H in portland cement pastes at variable temperature regime%变温下 Ba2+对水泥浆体C-S-H微结构的影响

    沈凡; 胡晨光; 赵明宇


    为从分子尺度优化C-S-H微结构提供理论依据,采用模拟大体积混凝土内部变温历程的养护制度,运用29 Si魔角旋转核磁共振(29 Si MAS NMR)结合去卷积技术,研究了变温条件下Ba(OH)2掺量为1.0%时对水泥浆体C-S-H微结构的影响规律。结果表明:在变温条件下掺加Ba(OH)2提高了水泥浆体中硅酸盐矿物水化程度,尤其在水化早期(3 d)时硅酸盐矿物水化程度增幅较大,进而使C-S-H结构中硅氧四面体二聚体数量增加,导致其C-S-H平均分子链长(MCL)显著低于纯水泥浆体,避免了纯水泥浆体在降温阶段出现C-S-H的MCL降低的现象。同时,掺加Ba(OH)2进一步降低了水泥浆体在变温过程下C-S-H中Al3+取代Si4+的程度。%In order to provide the theoretical basis for optimizing the microstructure of C -S -H at molecular scale,by simulating the variable temperature process in the interior of mass concrete and using the 29 Si Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR)combined with deconvolution technique,effect of 1.0% Ba(OH)2 on C-S-H microstructure in Portland cement pastes at variable temperature regime was in-vestigated.The results show that the hydration of silicate minerals in cement pastes is improved by mixing the Ba(OH)2 at variable temperature regime,especially at the early stage hydration(3 d).The amount of silicate tetrahedra dimers is increased,leading to the mean chain length (MCL)of C -S -H in cement pastes with Ba(OH)2 lower than that in pure cement pastes,avoiding the phenomenon of C-S-H MCL reduction in pure cement pastes at the cooling stage.Meanwhile,the degree of Al3+substituting for Si4+is further decreased by adding to Ba(OH)2 in cement pastes at variable temperature regime.

  12. Development of safety MIS based on the C/S and B/S mixed model%C/S和B/S相结合的安全型管理信息系统开发

    陈军霞; 刘权乐; 陈玉增



  13. Observation of three different ferromagnetic phases with predictable T sub c s in La sub 2 MnCo sub 0 sub . sub 5 Ni sub 0 sub . sub 5 O sub 6

    Joly, V L J; Joy, P A


    The perovskite-type oxide La sub 2 MnCo sub 0 sub . sub 5 Ni sub 0 sub . sub 5 O sub 6 has been found to form in three different ferromagnetic phases with different transition temperatures, when a low-temperature synthesized sample is annealed at different temperatures. The interesting magnetic behaviour of the compound is due to the combination of different spin states of Mn, Co and Ni in the different phases of the compound. The magnetic transition temperatures of the three phases of the compound can be predicted from the T sub c s of La sub 2 MnCoO sub 6 and La sub 2 MnNiO sub 6. (letter to the editor)

  14. San Juanico, BCS, Mexico, hybrid electric plant renewable energies in the rural communities development; Planta electrica hibrida San Juanico, B.C.S., Mexico, las energias renovables en el desarrollo de las comunidades rurales

    Lopez Rios, Serafin [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad (Mexico)


    The hybrid electric plant of San Juanico, B.C.S., Mexico, is described in terms of its environmental goals, operating process and contribution to the development of that rural community of the Baja California Peninsula. San Juanico hybrid electric plant is organized in three electrical generation systems that work in parallel: one uses solar energy, another wind energy and a third one uses diesel fuel. [Spanish] Se describe la planta hibrida de San Juanico, BCS, Mexico, en terminos de los objetivos ambientales que condujeron a su realizacion, asi como de su proceso operativo y de la participacion que tiene en el desarrollo de esa comunidad rural de la peninsula de Baja California, Mexico. La planta hibrida de San Juanico esta constituida por tres sistemas de generacion de electrcicidad que operan en paralelo: uno utiliza energia radiante del sol, otro energia del viento y un tercero utiliza diesel.

  15. Simultaneous Synchrotron WAXD and Fast Scanning (Chip) Calorimetry: On the (Isothermal) Crystallization of HDPE and PA11 at High Supercoolings and Cooling Rates up to 200 °C s(-1).

    Baeten, Dorien; Mathot, Vincent B F; Pijpers, Thijs F J; Verkinderen, Olivier; Portale, Giuseppe; Van Puyvelde, Peter; Goderis, Bart


    An experimental setup, making use of a Flash DSC 1 prototype, is presented in which materials can be studied simultaneously by fast scanning calorimetry (FSC) and synchrotron wide angle X-ray diffraction (WAXD). Accumulation of multiple, identical measurements results in high quality, millisecond WAXD patterns. Patterns at every degree during the crystallization and melting of high density polyethylene at FSC typical scanning rates from 20 up to 200 °C s(-1) are discussed in terms of the temperature and scanning rate dependent material crystallinities and crystal densities. Interestingly, the combined approach reveals FSC thermal lag issues, for which can be corrected. For polyamide 11, isothermal solidification at high supercooling yields a mesomorphic phase in less than a second, whereas at very low supercooling crystals are obtained. At intermediate supercooling, mixtures of mesomorphic and crystalline material are generated at a ratio proportional to the supercooling. This ratio is constant over the isothermal solidification time.

  16. Based on C / S and B / S Mixed-mode Development of Meteorological Applications Software%基于C/S与B/S混合模式开发气象应用软件

    周鸿奎; 谢芳; 李霞


    A meteorological application system was developed through DelPhi, SQL Server, Asp, etc. It applies in tourism meteorology, medical C/S and D/S meteorology, model and application ot traffic meteorology, sand therapy meteorology. The development methods of%通过使用C/S与B/S的混合开发模式,应用Delphi、SQL Server、Asp等关键技术,开发了一套适于本地的集旅游气象、医疗气象、交通气象、沙疗气象为一体气象服务应用系统,初步探索了气象业务应用软件的开发方法。

  17. The operational forecast system on red tide drift based on the C/S System Structure%基于C/S架构的业务化赤潮漂移扩散预报

    杨静; 蔡文博; 李海


    以风场、三维海流场数值预报结果作为输入强迫,建立了赤潮漂移扩散数值预报模型,并开发了相应的软件模块.模块基于C/S(客户端/服务器端)架构,通过数值模拟技术以及GIS、Web Services等信息技术,实现“提交预报请求—数值模式计算—预报结果可视化—预报产品生成”自动化赤潮漂移与扩散预报工作流程.该预报模块具备数据预处理、人机交互参数输入、数值模式计算、预报结果可视化和预报产品制作功能.以长江口附近海域历史赤潮为例进行后报试验,预测了赤潮藻团在风与流场共同作用下的漂移路径变化,结果与实际监测情况一致.该模块的业务化应用能进一步完善现有的赤潮预报系统,将成为赤潮防灾减灾的有力工具.%Forced by numerical forecast results of Wind field and three-dimensional current, a red tide drift prediction model was established. The development of appropriate software modules, which is based on C/S (client /server) architecture, unifies the "forecast request - numerical simulation - results of visualization - the forecast products generated "automated red tide drift and spread forecasting process by the numerical technology GIS and Web Services. The forecast module is provided by data preprocessing, the input of human-computer interaction parameters, numerical calculations, results visualization and forecasting production function, Hindcast test of the history red tide near the Yangtze Delta is conducted to predict the drift path of the red tide algae group under the joint action of the wind and water current. The results are consistent with the actual monitoring data. The operational application of the module can further improve the existing red tide forecasting system, and will become a powerful tool for the red tide disaster prevention and mitigation.

  18. 基于C/S结构的医院门诊管理信息系统设计与开发%Design & Development of Outpatient Management Information System Based on C/S Structure



    以一个大型医院管理信息系统项目为对象进行研究,着重讲述医院门诊管理信息系统主要功能模块的需求分析、业务流程分析、数据库设计及主要功能模块的实现.系统程序的编写采用面向对象的开发语言PowerBuilder,底层数据库采用SQL Server,整个系统为提高运行效率而采用C/S结构开发.%The research object of the HIS article is a practical item, a large HIS. The article emphatically narrates demand analysis , the service flow analysis, the database design and the main modules used in the system. The program language of the system is PowerBuilder which is object-oriented, the data base is SQL Server. To improve operating efficiency and system development the system uses C/S architecture.

  19. Physics Proofs of Four Millennium-Problems(MP) via CATEGORY-SEMANTICS(C-S)/F=C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

    Clay, London; Siegel, Edward Carl-Ludwig


    Siegel-Baez Cognitive-Category-Semantics"(C-C-S) tabular list-format matrix truth-table analytics SoO jargonial-obfuscation elimination query WHAT? yields four "pure"-maths MP "Feet of Clay!!!" proofs: (1) Siegel [AMS Natl.Mtg.(02)-Abs.973-03-126: (CCNY;64)(94;Wiles)] Fermat's: Last-Thm. = Least-Action Ppl.; (2) P=/=NP TRIVIAL simple Euclid geometry/dimensions: NO computer anything"Feet of Clay!!!"; (3) Birch-Swinnerton-Dyer conjecture; (4) Riemann-hypotheses via COMBO.: Siegel[AMS Natl.Mtg.(02)-Abs.973-60-124] digits log-law inversion to ONLY BEQS with ONLY zero-digit BEC, AND Rayleigh[1870;graph-thy."short-CUT method"[Doyle-Snell, Random-Walks & Electric-Nets,MAA(81)]-"Anderson"[(58)] critical-strip C-localization!!! SoO DichotomY ("V") IdentitY: #s:(Euler v Bernoulli) = (Sets v Multisets) = Quantum-Statistics(FD v BE) = Power-Spectra(1/f(0) v 1/f(1)) = Conic-Sections(Ellipse v Hyperbola) = Extent(Locality v Globality);Siegel[(89)] (so MIScalled) "complexity" as UTTER-SIMPLICITY(!!!) v COMPLICATEDNESS MEASURE(S) definition.

  20. 碳硫比对磷石膏分解率的影响研究%The Effect of C/S Ratio on the Decomposition Rate of Phosphogypsum

    刘大东; 陈前林; 李文飞; 罗焕虎


    In nitrogen,decomposition of phosphogypsum was not exactly the same at different temperatures.Raising the temperature of calcination and prolong the time of heat preservation can effectively improve the decomposition rate of phosphogypsum.At 1100 ℃ and 1150 ℃,C/S=0.7,the decomposition can reach above 99% for 20 min.The decomposition of phosphogypsum rate can reach more than 99% under the constant temperature 1200 ℃ for 5 min.%在氮气条件下,磷石膏在不同温度、碳硫比和保温时间下的分解情况不尽相同,提高煅烧温度和延长保温时间可有效的提高磷石膏的分解率。在1100℃和1150℃、碳硫比0.7、保温20 min时,磷石膏分解的分解率可达在99%以上;而在1200℃、保温5 min后,磷石膏的分解率可以达到99%以上。

  1. 基于C/S模式的轮胎胶囊硫化机远程监控系统设计%Remote monitoring system for tyre capsule vulcanizer based on C/S

    苗岱江; 邢建国; 张华


    Tyre capsule vulcanizer remote monitoring system which based on C/S mode is developed by using the VC++6.0 as programming method in the Windows environment by the TCP/IP communication protocol. In this paper, client / server mode and the tyre capsule vulcanizing process are introduced, realization method of key technologies such as network communication and remote database are presented. The application indicated that the system is good at real time and works safely, and has widely used in the future.%在Windows环境下采用Visual C++ 6.0开发工具,遵循TCP/IP网络通信协议,开发了基于C/S模式的轮胎胶囊硫化机的远程监控系统.对客户端/服务器模式、胶囊硫化机的工作过程进行了介绍,对网络通信和远程数据库等关健技术给出了实现方法.运行结果表明,该系统具有良好的实时性和安全性,具有较强的实际应用价值.

  2. 基于C/S模式的煤矿监控系统的应用研究%Study on application of Coalmine Monitoring System based on C/S mode

    梁志勇; 戴胜华


    Aimed at the demand for the current development of Coalmine Monitoring System, in order to provide better compatibility and scalability, this paper introduced the design of Monitoring System based on C/S structure. This design adopted LM3S8962 microprocessor of 32-bit ARM-based, and selected the open source embedded Operating System RTThread, and used TCP/IP protocol as the method to communicate with the central computer. The result showed that it could meet the requirement of real-time monitoring and multi-tasks, ensure the rate of data transfer.%针对当前煤矿监控系统的发展要求,为了寻求更好的兼容性和可扩展性,介绍一种基于C/S结构的监控系统的设计方案.该方案采用32 bit ARM微处理器LM3S8962,选用源代码开放的RT-Thread嵌入式操作系统,并使用TCP/IP协议作为通讯协议与控制中心计算机进行网络通信.测试表明,该监控系统能满足实时性和多任务的要求,并保证数据传输速度.

  3. Interaction of calcium silicate hydrates (C-S-H), the main components of cement, with alkaline chlorides, analogy with clays; Interaction des silicates de calcium hydrates, principaux constituants du ciment, avec les chlorures d'alcalins. Analogie avec les argiles

    Viallis-Terrisse, H


    This work, belonging to a more general study on the structure and reactivity of cement, deals with the experimental and theoretical analysis of the interaction of alkaline chlorides with calcium silicate hydrates (C-S-H), the main components of cement paste. The interaction of alkaline cations with C-S-H is interfacial, involving both electrostatic and surface complexation mechanisms. The C-S-H surface is constituted of silanol sites, partially dissociated due to the high pH of the interstitial solution. The calcium ions, present in large amounts in the equilibrium solution of C-S-H, constitute potential determining ions for the C-S-H surface. The alkaline ions seem to compete with calcium for the same surface sites. The adsorption isotherms show that caesium presents a better affinity than sodium and lithium for the C-S-H surface. Moreover, solid-state NMR suggests that caesium forms with the surface sites inner-sphere complexes, whereas sodium seems to keep its hydration sphere. These results are in agreement with zeta potential measurements, which let suppose a specific adsorption of caesium ions, and an indifferent behaviour of both other alkaline ions. A model for the C-S-H surface was proposed, from the electric double layer model, and mass action laws expressing the complexation of the different ionic species with the silanol sites. The whole study relies on a structural analogy with smectites, some clays presenting well-known cationic adsorption properties. The structural similarity between both minerals is enhanced by some similarities of reactivity, though significant behaviour differences could also be noted. (author)

  4. Correlação entre a cistatina C sérica e marcadores de aterosclerose subclínica em pacientes hipertensos Correlation between serum cystatin C and markers of subclinical atherosclerosis in hypertensive patients

    Francisco das Chagas Monteiro Junior


    Full Text Available FUNDAMENTO: A cistatina C sérica (s-CC, um marcador endógeno da função renal, tem sido proposta também como um marcador de risco cardiovascular. No entanto, ainda não está estabelecido se se trata de um marcador direto de aterosclerose, independentemente da função renal. OBJETIVO: O objetivo deste estudo foi correlacionar a s-CC com dois marcadores substitutos de aterosclerose subclínica. MÉTODOS: Trata-se de um estudo transversal envolvendo 103 pacientes hipertensos ambulatoriais, de meia idade (57,49 ± 11,7 anos, sendo 60 do sexo feminino (58,25% e a maioria com função renal preservada. A s-CC foi correlacionada com a espessura mediointimal carotídea (EMIc e a dilatação mediada por fluxo de artéria braquial (DMF, ambas avaliadas por ultrassonografia, bem como com o clearance de creatinina medido e fatores de risco cardiovascular estabelecidos. RESULTADOS: A s-CC não se correlacionou significativamente nem com a EMIc (r = -0,024, p = 0,84 nem com a DMF (r = -0,050 e p = 0,687, e não foi observada também associação significativa com fatores de risco convencionais nem marcadores inflamatórios. Na análise univariada, a s-CC se correlacionou com o clearance de creatinina medido (r = - 0,498, p BACKGROUND: Serum cystatin C (s-CC, an endogenous marker of kidney function, has also been proposed as a cardiovascular risk marker. However, it is unknown whether it is a direct marker of atherosclerosis, independently of kidney function. OBJECTIVE: The aim of this study was to correlate s-CC with two surrogate markers of subclinical atherosclerosis. METHODS: This is a cross-sectional study involving 103 middle-aged (57.49 ± 11.7 years hypertensive outpatients, being 60 female (58.25%, most with preserved kidney function. S-CC was correlated with carotid intima media thickness (IMT and flow-mediated dilation of brachial artery (FMD, both assessed by ultrasound, as well as with measured creatinine clearance and established

  5. 解釈する力を高める発問 : C.S.Peirceの認識論に基づく「読みの授業論」の構築(2)

    佐藤, 佐敏


    解釈する力を高めるためには, どのような授業において, どのような発間をすると良いのであろうか。筆者は, C.S. Pierce の pragmatism の格率と abduction の理論を援用し, 解釈するという読みの営みを次のような推論過程で捉えた。「文章を解釈するということは, 文字情報を入力し, 読み手が各自の既有知識に基づいて推論する営みである。」この推論過程を鍛えると, 解釈する力が高まる。そのためには以下の発間が考えられる。(1)複数の根拠をあげることが可能となる発間。(2)複数の理由付けをあげることが可能となる発間。(3)複数の解釈の比較ができる発間。なお, これらの発間に答える時に, 根拠と既有知識を往復させて推論過程を見直させることが, 解釈を高めるための要件となる。例えば, 「相反する解釈を二つ提示し, どちらの解釈が良いかを考える発問」は, 複数の根拠をあげて複数の理由付けを考えることになる。その時に, それぞれの推論過程を見直すことになるので, 解釈する力を高める上で, 有効である。...

  6. Experimental and computational thermochemical study of sulfur-containing amino acids: L-cysteine, L-cystine, and L-cysteine-derived radicals. S-S, S-H, and C-S bond dissociation enthalpies.

    Roux, Maria Victoria; Foces-Foces, Concepción; Notario, Rafael; da Silva, Manuel A V Ribeiro; da Silva, Maria das Dores M C Ribeiro; Santos, Ana Filipa L O M; Juaristi, Eusebio


    This paper reports an experimental and theoretical study of the standard (p(degrees) = 0.1 MPa) molar enthalpies of formation at T = 298.15 K of the sulfur-containing amino acids l-cysteine [CAS 52-90-4] and l-cystine [CAS 56-89-3]. The standard (p(degrees) = 0.1 MPa) molar enthalpies of formation of crystalline l-cysteine and l-cystine were calculated from the standard molar energies of combustion, in oxygen, to yield CO2(g) and H2SO4.115H2O, measured by rotating-bomb combustion calorimetry at T = 298.15 K. The vapor pressures of l-cysteine were measured as function of temperature by the Knudsen effusion mass-loss technique. The standard molar enthalpy of sublimation, at T = 298.15 K, was derived from the Clausius-Clapeyron equation. The experimental values were used to calculate the standard (p(degrees) = 0.1 MPa) enthalpy of formation of l-cysteine in the gaseous phase, DeltafH(degrees)m(g) = -382.6 +/- 1.8 kJ x mol-1. Due to the low vapor pressures of l-cystine and since this compound decomposes at the temperature range required for a possible sublimation, it was not possible to determine its enthalpy of sublimation. Standard ab initio molecular orbital calculations at the G3(MP2)//B3LYP and/or G3 levels were performed. Enthalpies of formation, using atomization and isodesmic reactions, were calculated and compared with experimental data. A value of -755 +/- 10 kJ x mol-1 was estimated for the enthalpy of formation of cystine. Detailed inspections of the molecular and electronic structures of the compounds studied were carried out. Finally, bond dissociation enthalpies (BDE) of S-H, S-S, and C-S bonds, and enthalpies of formation of l-cysteine-derived radicals, were also computed.


    罗国涛; 裴广


    针对各个电影系统数据资源有限且不能共享、人们通过智能手机访问最新影视信息效率低下以及手机客户端多任务访问服务端时易出现未响应错误,提出一种基于WebService 和Android的C/S +B/S 结构手机电影系统实现方法。系统总体由An-droid手机客户端、JavaEE服务器端和基于WebService的分布式异构数据库三部分组成。在手机桌面主屏上采用AppWidget组件方便用户以多角度快速浏览最新影视信息从而增强用户独特的视觉体验。手机客户端访问服务器端时客户端采用线程池方法避免手机出现ANR错误。后台管理系统采用SSH2+JQuery+JSON组合框架使得展示层、业务层以及数据持久层三层分离,降低了系统各模块的耦合性,提高了系统的可维护性和可重用性。为更好地实现电影数据共享,系统中心数据库采用触发器与日志表法、API法相结合的变更数据捕获方法实现了分布式异构数据库的同步操作。通过实验证明了该系统的可行性及实用性。%Aiming at the problems that every movie system is limited in data resources and cannot share each other,the efficiency of peo-ple accessing to the latest movie information through smart phones is low,and the access to server by cellphone client in multitask mode is prone to not-responding error,in this article we proposed a WebService and Android-based implementation method of C/S+B/S architecture cellphone movie system.The system is composed of three parts,the Android client,the JavaEE server and the WebService-based distributed heterogeneous database.In cellphone desktop main screen,the AppWidget component is used,this makes the users convenient to have a quick browse on the latest film and television information with various angles so as to enhance users'unique visual experience.When the cell-phone client accessing the server,the client uses thread pool method to avoid ANR mistakes

  8. Libraries of RGD analogs, labeled through ReO{sup 3+} or TcO{sup 3+} coordination, targeting {alpha}V{beta}3 integrin: development of tracers for the early detection of tumor neo-angiogenesis; Chimiotheques de complexes du technetium et du rhenium ciblant l'integrine {alpha}V{beta}3: developpement de traceurs pour la detection precoce de la neoangiogenese tumorale

    Aufort, M.


    Integrins form a family of hetero-dimeric integral glycoproteins which play a central role in cell-cell adhesion and cell-matrix interactions. In particular, they are over expressed during tumor neo-angiogenesis. About 10 of them recognize a structured RGD (Arg-Gly-Asp) sequence. Analogs of this sequence can be used for the early detection of tumors and metastases. We developed new tracers, labeled with {sup 99m}Tc, for the molecular imaging of {alpha}{sub V{beta}3} integrin. Until recently, there was no reliable ab initio structure prediction of complex molecules containing Re and Tc chelates. Therefore, we preferred a combinatorial approach to develop potential ligands of {alpha}{sub V{beta}3} integrin and we attempted to identify efficient tracers by in vivo screening. This method would account for biodistribution and pharmacokinetics properties in the early steps of the study. Tracers were obtained according two strategies: i) cyclization of linear RGD analogs; ii) combinatorial assembling of independent modules through metal core coordination by the well-known NS{sub 2}+S motif. After synthesis and labeling, the stability of the tracers was investigated in presence of glutathione and in murine plasma. In vitro screening on purified integrin showed that a cyclic rhenium coordinate binds specifically {alpha}{sub V{beta}3}. A tumor model (U87-MG tumor on nude mice) was validated in the laboratory and a method was developed to analyze in vivo experiments. Biodistribution data and percentage of activity found in tumors are encouraging for cyclic compounds though identification of efficient tracers is difficult due to their instability in the conditions of analyses. (author)


    Setyawan, Wahyu; Nandipati, Giridhar; Kurtz, Richard J.


    Reference data are generated using the ab initio method to fit interatomic potentials for the W-Re system. The reference data include single phases of W and Re, strained structures, slabs, systems containing several concentrations of vacancies, systems containing various types of interstitial defects, melt structures, structures in the σ and χ phases, and structures containing several concentrations of solid solutions of Re in bcc W and W in hcp Re. Future work will start the fitting iterations.

  10. Rhenium-Catalyzed Deoxydehydration of Diols and Polyols

    Dethlefsen, Johannes Rytter; Fristrup, Peter


    , is the heniumcatalyzeddeoxydehydration (DODH) of a vicinal diol into analkene; this is a model system for abundant polyols like glyceroland sugar alcohols. The present contribution includesa review of early investigations of stoichiometric reactions involvingrhenium, diols, and alkenes followed by a discussion ofthe various catalytic...... systems that have been developed withemphasis on the nature of the reductant, the substrate scope,and mechanistic investigations....

  11. Technetium and rhenium: coordination chemistry and nuclear medical applications

    Abram,Ulrich; Alberto, Roger


    Coordination compounds of the radioactive element technetium are well established in diagnostic nuclear medicine, and various complexes of the gamma-emitting nuclide 99mTc are routinely used for organ imaging. Modern trends in the radiopharmaceutical chemistry of technetium focus on the 'labeling' of biologically active molecules such as peptides, steroids or other receptor-seeking units. This requires more knowledge about the coordination chemistry of the artificial transition metal, particu...

  12. Surface-Cycling of Rhenium and its Isotopes


    average Mo concentration. B: Cumulative Yenisei H2O and Mo fluxes for 2004. 63 Jan 1 0.5 0 1.5 2.0 W a te r flu x, k m 3 d -1 Calendar date, 2004 2.5...and Applied Chemistry, 70: 217–235. [27, 126, 135] Russ, G. P., Bazan , J. M., and Date, A. R. (1987), Osmium isotopic ratio measure- ments by

  13. Abundances and Orbit of the Rhenium Star HD 65949

    Cowley, C. R.; Hubrig, S.; Palmeri, P.; Quinet, P.; Biémont, E.; Wahlgren, G. M.; Schütz, O.; González, J. F.


    HD 65949 is a late B star in NGC 2516. Two X-ray sources are within 1". The spectrum arguably falls outside of the usual CP star classifications. It may be most closely related to the HgMn stars, having strong Hg II λ3984, and Pt II. But while ? is exceptionally strong, Mn II is only mildly enhanced. The rarely observed Re II spectrum is extraordinarily well developed. Other uncommon identifications are Kr II, Os II, and Th III. Preliminary quantitative work by Cowley, Hubrig, and Wahlgren (JPhCS, 130, 012005, 2008) is now extended to abundances or upper limits of 58 elements. Calculations of atomic structures by the Mons group, assessed through comparisons with experiment, have provided a large number of oscillator strengths making it possible to derive reliable abundances from rare 5d ions, as well as the 4d spectrum of Ru II. Nb II (4d) is confirmed, and its abundance determined using recent work of Nilsson and Ivarsson (A&A, 492, 609, 2008). Many Re II (5d) lines show broad hyperfine structure, easily resolved on ESO HARPS spectra. We provide new orbital elements for this known SB1. The period is 21.28 days and is slowly increasing, indicating the presence of a third body. Using the spectroscopic Teff=13100 and log(g) = 4.0, as well as the orbital data, we estimate primary and secondary masses near 3.3 and 1.6 M⊙, with a separation of some 0.25 AU. Observations: ESO (UVES Progs. 076.D-0172, 081.D-0498), HARPS, and from Complejo Astronomico El Leoncito. Support from Belgian FRS-FNRS is gratefully acknowledged.

  14. Improved Rhenium Thrust Chambers for In-Space Propulsion Project

    National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems (RCS) for future NASA missions such...

  15. Cationic technetium and rhenium complexes with pendant carbohydrates

    Ferreira, Cara L. [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)], E-mail:; Marques, Fabio L.N. [Centro de Medicina Nuclear, Faculdade de Medicina, Universidade de Sao Paulo, Trav. R. Dr. Ovidio Pires de Campos s/n Sao Paulo, 05403-010 (Brazil)], E-mail:; Okamoto, Miriam R.Y. [Centro de Medicina Nuclear, Faculdade de Medicina, Universidade de Sao Paulo, Trav. R. Dr. Ovidio Pires de Campos s/n Sao Paulo, 05403-010 (Brazil); Otake, Andreia H. [Laboratorio de Oncologia Experimental, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Sao Paulo 01246-903 (Brazil); Sugai, Yuko; Mikata, Yuji [KYOUSEI Science Center, Nara Women' s University, Nara 630-8506 (Japan); Storr, Tim; Bowen, Meryn [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1 (Canada); Yano, Shigenobu [Division of Functional Material Science, Nara Women' s University, Nara 630-8506 (Japan); Adam, Michael J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Chammas, Roger [KYOUSEI Science Center, Nara Women' s University, Nara 630-8506 (Japan); Orvig, Chris [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada)


    Three carbohydrate conjugated dipicolylamine chelators, 2-bis(2-pyridinylmethyl)amino)ethyl 1-deoxy-1-thio-{beta}-D-glucopyranoside (L{sup 1}), 2-bis(2-pyridinylmethyl)amino)ethyl-{beta}-D-glucopyranoside (L{sup 2}), and 2-bis(2-pyridinylmethyl)amino) carboxamide-N-(2-amino-2-deoxy-D-glucopyranose) (L{sup 3}) were complexed to the [M(CO){sub 3}]{sup +} core (M=Tc, Re) and the properties of the resulting complexes were investigated. Synthesis and characterization of the chelator 2-bis(2-pyridinylmethyl)amino)ethyl 1-deoxy-1-thio-{beta}-D-glucopyranoside (L{sup 1}) and the corresponding Re complex are reported. All chelators were radiolabeled in high yield with [{sup 99m}Tc(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (>98%) and [{sup 186}Re(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (>80%). The chelators and Re-complexes were determined to not be substrates for the glucose metabolism enzyme hexokinase. However, the biodistribution of each of the {sup 99m}Tc complexes demonstrated fast clearance from most background tissue, including >75% clearance of the activity in the kidneys and the liver within 2 h post-injection.

  16. Dissociative chemisorption of N2 on Rhenium

    Billing, Gert D.; Guldberg, Annette; Henriksen, Niels Engholm


    mechanically using the FFT (fast Fourier transform) technique. Also normal modes of the solid are quantized using a quantum boson approach and the remaining degrees of freedom are treated classically. Full corrugation of the surface and phonon coupling to infinite order as well as rotational motion...

  17. Unsaturated platinum-rhenium cluster complexes. Synthesis, structures and reactivity.

    Adams, Richard D; Captain, Burjor; Smith, Mark D; Beddie, Chad; Hall, Michael B


    Two new compounds PtRe3(CO)12(PBut3)(micro-H)3, 9, and PtRe2(CO)9(PBut3)(micro-H)2, 10, were obtained from the reaction of Pt(PBut3)2 with Re3(CO)12(micro-H3), 8, at room temperature. Compound 9 contains a butterfly cluster of four metals formed by the insertion of the platinum atom from a Pt(PBut3) group into one of the hydride-bridged metal-metal bonds of 8. The three hydrido ligands are bridging ligands across each of three new Pt-Re bonds. Compound 10 contains a triangular PtRe2 cluster with two hydrido ligands; one bridges a Pt-Re bond, and the other bridges the Re-Re bond. The new compound Pt2Re2(CO)7(PBut3)2(micro-H)2, 11, was obtained from the reaction of 8 with Pt(PBut3)2 in hexane at reflux. Compound 11 was also obtained from 10 by reaction with an additional quantity of Pt(PBut3)2. Compound 11 contains a tetrahedral cluster of four metal atoms with two dynamically active hydrido ligands. A CO ligand on one of the two platinum atoms also exchanges between the two platinum atoms rapidly on the NMR time scale. Compound 11 is electronically unsaturated and was found to add hydrogen at room temperature to form the tetrahydrido cluster complex, Pt2Re2(CO)7(PBut3)2(micro-H)4, 12. Compound 12 has a structure similar to 11 but contains one triply bridging hydrido ligand, two edge bridging hydrido ligands, and one terminal hydrido ligand on one of the two platinum atoms. A kinetic isotope effect D/H of 1.5(1) was determined for the addition of H2 to 11. Hydrogen can be eliminated from 12 by heating to 97 degrees C or by the application of UV-vis irradiation at room temperature. Compound 12 adds CO at room temperature to yield the complex Pt2Re2(CO)8(PBut3)2(micro-H)4, 13, which contains a planar cluster of four metal atoms with a Pt-Pt bond and four edge bridging hydrido ligands. Compounds 11 and 12 react with Pt(PBut3)2 to yield the known five metal cluster complexes Pt3Re2(CO)6(PBut3)3(micro-H)2, 14, and Pt3Re2(CO)6(PBut3)3(micro-H)4, 15, respectively. Density functional calculations confirm the hydride positions in the lowest energy structural isomers of 11 and 12 and suggest a mechanism for H2 addition to 11 that occurs on the Pt atom with the lower coordination number.

  18. The crystal structure of some rhenium and technetium dichalcogenides

    Lamfers, H.J; Meetsma, A.; Wiegers, G.A; deBoer, J.L.


    The crystal structures of ReSe2,ReS2, ReSSe and TcS2 are determined using single crystal X-ray diffraction. The compounds are triclinic with space group P (1) over bar. ReSe2, Res(2) and ReSSe have a distorted CdCl2-type structure; TcS2 has a distorted Cd(OH)(2)-type structure. In the case of Res,

  19. Rhenium(IV) compounds inducing apoptosis in cancer cells.

    Martínez-Lillo, José; Mastropietro, Teresa F; Lappano, Rosamaria; Madeo, Antonio; Alberto, Marta E; Russo, Nino; Maggiolini, Marcello; De Munno, Giovanni


    The anticancer properties of a series of mononuclear Re(IV) compounds of formula ReCl(4)L (where L is bpy = 2,2'-bipyridine; bpym = 2,2'-bipyrimidine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine; phen = 1,10-phenanthroline) were investigated for the first time. All compounds displayed potent in vitro antiproliferative activity against selected cancer cells.

  20. Syntheses, reactions, and structures of dioxycarbene complexes of rhenium

    Miessler, G.L.; Kim, S.; Jacobson, R.A.; Angelici, R.J.


    The cyclic dioxycarbene complex Re(CO)4Br(COCH2CH2O) (I) reacts with PPh3 to give initially fac-Re(CO)3(PPh3)Br(COCH2CH2O) (II) and upon further reaction Re(CO)2(PPh3)2Br(COCH2CH2O) (II). The reaction of I with the diphosphines Ph2P(CH2)/sub n/PPh2 (n = 1,2) gives the diphosphine-bridged complexes (Re(CO)3Br(COCH2CH2O))2(Ph2P(CH2)/sub n/PPh2) (IV, n = 1; V, n = 2). The structures of I and V were established by X-ray diffraction studies. The crystals of I are orthorhombic, space group Pbca, with a = 11.764 (2) A, b = 17.579 (4) A, c = 10.658 (2) A, and Z = 8, while those of V are triclinic, space group P anti I, with a = 11.160 (2) A, b = 11.369 (3) A, c = 10.090 (3) A, = 111.58 (3), US = 95.40 (2), el = 92.78 (2), Z = 1, and two acetones ((CH3)2CO) of crystallization. The dimethyldithiocarbamate ion, S2CN(CH3)2, reacts with I to remove in effect ethylene oxide form the carbene ligand, giving Gr(CO)5Br and HOCH2CH2SC(=S)N(CH3)2.

  1. Nanostructured Tungsten Rhenium Components for Propulsion Systems Project

    National Aeronautics and Space Administration — Revolutionizing the space propulsion industry through innovative, relatively low-cost, manufacturing techniques is extremely needed. Specifically, advancements are...

  2. Improved Rhenium Thrust Chambers for In-Space Propulsion Project

    National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems for NASA missions such as Mars Sample...

  3. Design and implementation of client software automatic upgrade for C/S pattern in distributed environment%分布式环境下 C/S模式客户端软件自动在线升级的设计与实现



    通过分布环境下C/S模式软件在线自动升级的实现,揭示了在必须采用C/S模式实现业务应用时进行软件及时的自动升级的可行性.在具体应用环境下克服了C/S模式部署困难,升级不方便,维护成本高几个不利的因素,将客户端描述文件中的程序最近一次更新日期或版本号与服务器端升级程序的最近一次更新日期或版本号进行比较,使系统自动感知新程序的存在,在设计上采用首启动探寻式最新版本更新,克服了定时探索新版所带来的网络资源的消耗,对打造多元化综合软件应用架构进行了积极的探索与应用.%Through the design and implement of client software automatic upgrade for C/S pattern in distributed environment,it opens out a feasibility that carry out software automatic upgrade in time when we must make use of C/S pattern. It overcomes a number of disadvantage complication, for example,difficult deployment,inconvenient upgrade cost maintenance for C/S pattern under the some application environment. It compares program update date and time or version number between client side and server side in description files, making the system automatically apperceive newer program exists. It can be used to make multi complex software architecture.

  4. X-ray crystallographic characterization of new soluble endohedral fullerenes utilizing the popular C82 bucky cage. Isolation and structural characterization of Sm@C3v(7)-C82, Sm@C(s)(6)-C82, and Sm@C2(5)-C82.

    Yang, Hua; Jin, Hongxiao; Wang, Xinqing; Liu, Ziyang; Yu, Meilan; Zhao, Fukun; Mercado, Brandon Q; Olmstead, Marilyn M; Balch, Alan L


    Three isomers of Sm@C(82) that are soluble in organic solvents were obtained from the carbon soot produced by vaporization of hollow carbon rods doped with Sm(2)O(3)/graphite powder in an electric arc. These isomers were numbered as Sm@C(82)(I), Sm@C(82)(II), and Sm@C(82)(III) in order of their elution times from HPLC chromatography on a Buckyprep column with toluene as the eluent. The identities of isomers, Sm@C(82)(I) as Sm@C(s)(6)-C(82), Sm@C(82)(II) as Sm@C(3v)(7)-C(82), and Sm@C(82)(III) as Sm@C(2)(5)-C(82), were determined by single-crystal X-ray diffraction on cocrystals formed with Ni(octaethylporphyrin). For endohedral fullerenes like La@C(82), which have three electrons transferred to the cage to produce the M(3+)@(C(82))(3-) electronic distribution, generally only two soluble isomers (e.g., La@C(2v)(9)-C(82) (major) and La@C(s)(6)-C(82) (minor)) are observed. In contrast, with samarium, which generates the M(2+)@(C(82))(2-) electronic distribution, five soluble isomers of Sm@C(82) have been detected, three in this study, the other two in two related prior studies. The structures of the four Sm@C(82) isomers that are currently established are Sm@C(2)(5)-C(82), Sm@C(s)(6)-C(82), Sm@C(3v)(7)-C(82), and Sm@C(2v)(9)-C(82). All of these isomers obey the isolated pentagon rule (IPR) and are sequentially interconvertable through Stone-Wales transformations.

  5. Valores de cistatina C sérica en recién nacidos pretérmino en nuestro medio. Relación con valores de creatinina sérica y patologías de la prematuridad

    Leonor Bardallo Cruzado


    Conclusiones: Descenso de CisC sérica a las 48-72 h de vida, siendo esta caída en el tiempo significativa (p < 0,05, ascenso a los 7 días, en los 3 grupos de EG y sin diferencias en valores de CisC entre los grupos. Se requieren más estudios en pretérminos con patología respiratoria y situaciones de hipotensión. En ≤ 1.500 g la CisC es mejor marcador de filtrado glomerular (FG.

  6. Dialogue Alone: D. C. S. Oosthuizen's Engagement with Three Philo ...


    model – that is, on the model of the right of a homeless person to buy a mansion, .... argued that every moment of life was a moment of crisis and decision. ... Kierkegaard's work was at the centre of graduate research at Stellenbosch and.

  7. Hadrons with c-s content: past, present and future

    Prencipe, Elisabetta


    The PANDA detector at FAIR aims to conduct an antiproton-proton experiment with a very high rate capability. It is expected to feature high mass resolution, more than 20 times better than achieved at B-factories. PANDA is in a unique position to perform highly resolved mass scan, and to measure the width of very narrow charm and charmonium-like states, whose nature is still unknown, 12 years after their discovery. In this report, we present a method to determine the width of the $D_{s0}^*(2317)^+$. We discuss the future perspectives of PANDA, based on our present simulations, in relation with the recent measurements performed by LHCb and the performances in this field at the B factories.

  8. The directed flow maximum near $c_{s} = 0$

    Brachmann, J; Stöcker, H; Greiner, W


    We investigate the excitation function of quark-gluon plasma formation and the rapidity dependence of directed in-plane flow of nucleons in the energy range of the BNL-AGS and for the $E^{kin}_{Lab}=40A$~GeV Pb+Pb collisions performed recently at the CERN-SPS. We employ the three-fluid model with dynamical unification of kinetically equilibrated fluid elements. Within our model with first-order phase transition at high density, droplets of QGP coexisting with hadronic matter are produced already at BNL-AGS energies, $E^{kin}_{Lab}\\simeq 10A$~GeV. A substantial decrease of the isentropic velocity of sound, however, requires higher energies, $E^{kin}_{Lab}\\simeq40A$~GeV. We calculate the response of the directed in-plane momentum per nucleon, $(y)$. According to our model calculations, kinematic requirements and EoS effects work hand-in-hand at $E^{kin}_{Lab}=40A$~GeV to allow the observation of the dropping velocity of sound and of the ``slowly burning'' mixed phase via an {\\em increase} of the directed flow a...

  9. El Midwest Canto Al Pueblo: "otra vez, c/s"

    Guernica, Antonio Jose; Saavedra, Pilar


    El Midwest Canto Al Pueblo was a successful effort to bring artists, poets, musicians, and cultural workers together in a setting conducive to a free and easy interchange of ideas and directions in order to reaffirm, share, and celebrate the identity of La Raza with el pueblo. The activities during the 10-day festival included poetry readings,…

  10. Iúri Lótman, C. S. Peirce e semiose cultural

    Floyd Merrell


    Full Text Available Este artigo examina os processos sí­gnicos formulados por Peirce a partir da noção de espaço semiótico de Iúri Lótman. Manifestações particulares de espaço semiótico dentro da semiosfera são qualificadas como inconsistentes e/ou incompletas, dependendo do contexto cultural. Inconsistência e incompletude são da natureza da imprecisão e generalidade de Peirce respectivamente, por sua vez elas próprias qualificadas em termos de supradeterminação e subdeterminação, à luz das categorias peirceanas de primeiridade, secundidade e terceiridade que são discutidas em termos de homogenia, hegemonia e heterogenia respectivamente. Estes conceitos serão então utilizados como dispositivos de modelamento, fornecendo uma interpretação para um importante evento na cultura latino-americana. Palavras-chave semiosfera, categorias, homogenia, hegemonia, heterogenia, cultura latinoamericana Abstract This paper brings Lotman’s semiotic space to bear on Peirce’s sign processes. Particular manifestations of cultural semiotic space within the semiosphere are qualified as inconsistent and/or incomplete, depending upon the cultural context. Inconsistency and incompleteness are of the nature of Peirce’s vagueness and generality respectively, that are themselves qualified in terms of overdetermination and underdetermination. Overdetermination and underdetermination, in view of Peirce’s categories of Firstness, Secondness, and Thirdness, are discussed in terms of homogeny, hegemony, and heterogeny respectively. These concepts will then be used as a modeling device providing an interpretation for an important event in Latin American culture. Key words semiosphere, categories, homogeny, hegemony, heterogeny, Latin American culture

  11. Hadronization of b --> c$\\overline{c}$s

    Buchalla, Gerhard; Yamamoto, H; Buchalla, Gerhard; Dunietz, Isard; Yamamoto, Hitoshi


    The b -> c cbar s transition is usually believed to hadronize predominantly in Bbar -> X_c Ds(*)- with the Ds(*)- originating from the virtual W. We demonstrate in a variety of independent ways that other hadronization processes cannot be neglected. The invariant mass of cbar s has sizable phase-space beyond m_D+m_K. The rate for Bbar -> D Dbar Kbar X could be significant and should not be ignored as was done in previous experimental analyses. We estimate the number of charmed hadrons per B-decay, n_c, to be about 1.3 to higher accuracy than obtained in previous investigations. Even though n_c is currently measured to be about 1.1, observing a significant Bbar -> D Dbar Kbar X would support n_c of about 1.3. Many testable consequences result, some of which we discuss.

  12. El Midwest Canto Al Pueblo: "otra vez, c/s"

    Guernica, Antonio Jose; Saavedra, Pilar


    El Midwest Canto Al Pueblo was a successful effort to bring artists, poets, musicians, and cultural workers together in a setting conducive to a free and easy interchange of ideas and directions in order to reaffirm, share, and celebrate the identity of La Raza with el pueblo. The activities during the 10-day festival included poetry readings,…

  13. (6aS,11aR,11cS-8-Sulfanylidene-2,3,5,6,6a,7,11,11a,11b,11c-decahydro-3a,7a-diaza-1H,4H-benzo[de]anthracen-3a-ium chloride hemihydrate

    Liang Wang


    Full Text Available The title compound, C15H23N2S+·Cl−·0.5H2O, was prepared from (6aS,11aR,11cS-2,3,5,6,6a,7,11,11a,11b,11c-decahydro-3a,7a-diaza-1H,4H-benzo[de]anthracene-8-one (sophocarpine and Lawesson's reagent. The thione-substituted ring is in an envelope conformation and the three other six-membered rings are in chair conformations. In the crystal, anions and cations are linked by N—H...Cl and weak C—H...Cl hydrogen bonds. One 0.5-occupancy solvent water molecule lies on a twofold rotation axis and another 0.25-occupancy solvent water molecule is in a general position. The H atoms of these water molecules were not located or included in the refinement.

  14. 基于C/S模式的成像测井仪器调试台架软件系统研制%Development of the Test-bench Software System for Imaging Logging Tool Based on the C/S Mode

    杨喜峰; 鞠晓东; 吴文河


    根据微电阻率扫描测井仪调试台架软件功能需求,在对比C/S和B/S两种通讯模式基础上,确定基于C/S模式的软件通讯结构.为提高调试台架软件的可移植和扩展性,引入相应软件技术:前端机通过内核模块方法和多线程技术实现驱动程序动态管理和功能模块独立;上位机中采用MDI软件框架和组件技术实现结构开放和功能独立.微电阻率扫描测井仪调试台架软件系统设计结构扩展性强,组件功能可复用性强,方便移植到同类调试台架.%According to demand of the Micro-resistivity canning tool test-bench software demand, C/S and B/S two kinds of communication modes are contrasted, then confirms the software communication structure based on C/ S mode. In order to improve the portability and expansibility of the test-bench software, the corresponding software technology is introduced: front end machine realizes driver dynamic management and the independent function through the kernel modules method and multithread technology, main machine brings about the opening up of software structure and independent function through the MDI software framework and component technology. Based on the micro-resistivity scanning tool test-bench software system of above software technology has stronger portability and scalability, can easily transplant to other test- bench.

  15. Institute for separation chemistry of Marcoule I.C.S.M; Institut de chimie separative de Marcoule I.C.S.M



    Institute for Separation Chemistry was created in March 2007, and the building including laboratory and offices will be opened to scientists and technicians the middle of 2008. Since resources in Uranium are scarce and wastes related to nuclear energy production are potentially dangerous, the chemistry associated to nuclear energy production always followed the principles of green chemistry: close the life-cycle of material and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in processes. The Institute is devoted to chemistry at the service of the nuclear energy of the future, seen as an actor for sustainable development compatible with limited resources and chemical preservation of the atmosphere. Progresses in fundamental research, based on publication and education of students, engineers and young scientists, will be focused along seven identified directions, devoted to scattering and diffraction, microscopies and mainly mesoscopic modelling. The goals of the teams are described in this booklet, describing activities of the 28 scientists since two years. Separation chemistry, a branch of physical chemistry, is a key actor in 'green chemistry'. Nano-science and physical chemistry, at the roots of modern chemistry considering also non-covalent and long-range interactions, need to be included along the 'tools' involved in new processes. Three axis of research will be privileged: initial steps of separation, via dissolution by sono-chemical means, ion separation via colloids and complex fluids, and maintaining the separation between species involving self-repairing nano-materials, once the evolution of the interface fed from the evolving interface has been modelled. Eleven permanent staff scientists are already active since a few months on average at ICSM at the date of this report (5 CEA, 2 Universities and 4 CNRS). Teaching, scientific animation, summer schools and the common laboratory book of the UMR 5257 ICSM are managed by a team from CEA/INSTN. The activity report regroups goals of teams starting to work, together with previous recent activities of scientists now belonging to ICSM. This report describes the work done before (2003-2007) creation of ICSM by scientists now belonging to ICSM as well as the scientific work done in the first months of existence of ICSM, in the form of scientists integrated in host laboratories. Work done before is described on pages with a frame concern research performed before by scientists now staff permanent scientists at ICSM and related to the goals of ICSM. ICSM will be build by conjunction of the knowledge of scientists joining the group: at the date of writing - ten months before opening of the laboratory - 1/4 of the total number of permanent scientists have already joined the UMR 5257 and convene once every month. The report could have been presented either in administrative order, i.e. by the 'number' of the team, or starting from analysis of needs in nuclear and green chemistry. We have chosen the chronological order, i.e. the order of effective starts of experiments made by permanent ICSM staff.

  16. Melanoma Therapy with Rhenium-Cyclized Alpha Melanocyte Stimulating Hormone Peptide Analogs

    Thomas P Quinn


    Malignant melanoma is the 6th most commonly diagnosed cancer with increasing incidence in the United States. It is estimated that 54,200 cases of malignant melanoma will be newly diagnosed and 7,600 cases of death will occur in the United States in the year 2003 (1). At the present time, more than 1.3% of Americans will develop malignant melanoma during their lifetime (2). The average survival for patients with metastatic melanoma is about 6-9 months (3). Moreover, metastatic melanoma deposits are resistant to conventional chemotherapy and external beam radiation therapy (3). Systematic chemotherapy is the primary therapeutic approach to treat patients with metastatic melanoma. Dacarbazine is the only single chemotherapy agent approved by FDA for metastatic melanoma treatment (5). However, the response rate to Dacarbazine is only approximately 20% (6). Therefore, there is a great need to develop novel treatment approaches for metastatic melanoma. The global goal of this research program is the rational design, characterization and validation of melanoma imaging and therapeutic radiopharmaceuticals. Significant progress has been made in the design and characterization of metal-cyclized radiolabeled alpha-melanocyte stimulating hormone peptides. Therapy studies with {sup 188}Re-CCMSH demonstrated the therapeutic efficacy of the receptor-targeted treatment in murine and human melanoma bearing mice (previous progress report). Dosimetry calculations, based on biodistribution data, indicated that a significant dose was delivered to the tumor. However, {sup 188}Re is a very energetic beta-particle emitter. The longer-range beta-particles theoretically would be better for larger tumors. In the treatment of melanoma, the larger primary tumor is usually surgically removed leaving metastatic disease as the focus of targeted radiotherapy. Isotopes with lower beta-energies and/or shorter particle lengths should be better suited for targeting metastases. The {sup 177}Lu-DOTA-Re(Arg11)CCMSH and {sup 212}Pb-DOTA-Re(Arg11)CCMSH complexes were developed and synthesized to investigate its ability to target and deliver an effective dose to small melanoma tumors and metastatic deposits. Dosimetry calculations for {sup 188}Re-CCMSH and {sup 212}Pb/{sup 212}Bi[DOTA]-Re(Arg11)CCMSH were compared in the B16/F1 mouse melanoma flank tumor model to analyze the delivered dose to tumor and normal organs.

  17. Ultra-incompressible and hard technetium carbide and rhenium carbide: First-principles prediction

    Wang Yuan Xu [Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 475004 (China)


    Using density functional theory, the author predicts that the compounds ReC and TcC with the hexagonal WC-like structure are ultra-incompressible and hard materials. This is concluded from the very large bulk and shear moduli. The phonon dispersion reveals no soft modes indicating the stability of the two materials. The calculated density of states shows that ReC and TcC are metallic. The structural and elastic properties of OsC, IrC, and PtC with hexagonal and cubic structure are also investigated for comparison. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Mechanical properties of 50Molybdenum-50Rhenium alloys and their assembly by spinal muscular atrophy

    Xu, Jianhui

    This study is concerned with the deformation and fracture behaviors, especially strain-rate effect on plasticity in tensile tests, of two 50Mo-50Re alloys at strain rates ranging from 10-6 s-1 to 1 s-1 at room temperature in air. Metallographic observations of the 50Mo-50Re alloys before and after tensile deformation were conducted to understand the relationships among mechanical properties, microstructure and strain rate in these alloys. Understanding the strain-rate effect on mechanical properties of 50Mo-50Re alloys is important for optimizing forming operations, especially sheet forming, of these alloys, which are often used in cathode and aerospace applications. An anomalous strain-rate effect on ductility was observed in the 50Mo-50Re alloys. Ductility was significantly increased by increasing the strain rate from 10-6 s-1 to 1 s-1 in the fully-recrystallized and recovery heat-treated 50Mo-50Re alloys in tension at room temperature. At a low strain rate, fracture was predominantly brittle, while it was more ductile at higher stain rates. At a low strain rate, secondary cracks initiated at grain boundaries and triple junctions were observed in these alloys, which suggested that significant stress concentration was generated by tensile plastic deformation in the vicinity of grain boundaries, especially triple junctions. Electron backscatter diffraction experiments revealed that there was strain concentration at grain boundaries and their triple junctions during tensile deformation in these alloys. The decrease in ductility at low strain rates in the alloys was related to the possible interaction between dislocations and trace interstitial atoms (e.g., H, O, N and C) picked up during production of these alloys. This dissertation also reports the research efforts made to optimize small-scale resistance spot welding (SSRSW) of refractory alloy 50Mo-50Re thin sheet by adjusting seven important welding parameters, including hold time, electrode material, electrode shape, ramp time, weld current, electrode force, and weld time. The strength of the weld was improved from 100 N to 184.7 N after the optimization. The improved welding quality gave rise to the overall quality improvement of the traveling tubes for microwave telecommunication industry. The diameter of nuggets and formation of pores were also discussed in the study. KEYWORDS: Mechanical properties, Refractory alloy, Mo-Re alloy, Strain rate, Resistance spot welding.


    Setyawan, Wahyu; Nandipati, Giridhar; Kurtz, Richard J.


    In the previous semi annual report, we explored the stability of interstitial clusters in W up to size seven. In this report, we study the binding of those clusters to Re, Os, and Ta atoms. For each cluster size, the three most stable configurations are considered to average the binding property. The average binding energy to a Re decreases from 0.79 eV for a size-1 cluster (a [111] dumbbell) to 0.65 eV for a size-7 cluster. For Os, the binding decreases from 1.61 eV for a [111] dumbbell to 1.34 eV for a size-7 cluster. Tantalum is repulsive to interstitial clusters with binding energy ranges from -0.61 eV for a [111] dumbbell to -0.5 eV for a size-7 cluster.

  20. Localization of colorectal carcinoma by rhenium-188-labeled B72.3 antibody in xenografted mice

    Hosono, Masako N. [Osaka City Univ. (Japan). Medical School; Hosono, Makoto; Zamora, P.O.; Guhlke, S.; Haberberger, T.; Bender, H.; Knapp, F.F.R.; Biersack, H.J.


    In order to evaluate the feasibility of {sup 188}Re-labeled antibodies for radioimmunotargeting, monoclonal antibody B72.3, recognizing TAG-72, expressed on the surface membranes of colorectal cancer cells, was directly labeled with {sup 188}Re, obtained from a {sup 188}W/{sup 188}Re generator, using stannous tartrate and compared with {sup 125}I-labeled B72.3. As a control, a human IgG was also radiolabeled with {sup 188}Re and {sup 125}I. Prepared antibodies for {sup 188}Re labeling could be stored as kits. Biodistribution was determined in nude mice inoculated with human colorectal carcinoma LoVo. Labeling efficiency and immunoreactivity of {sup 188}Re-B72.3 were 80.3% and 64.7%, respectively. {sup 188}Re-B72.3 localized specifically in the LoVo tumors. Although the absolute tumor accumulation level of {sup 188}Re-B72.3 was lower than {sup 125}I-B72.3, {sup 188}Re-B72.3 demonstrated higher tumor-to-blood contrast than the {sup 125}I-labeled counterpart, 2.04{+-}0.44 vs. 1.05{+-}0.28 at 96 hours, because of fast clearance from the blood. {sup 188}Re-B72.3 seemed efficient for the imaging and therapy of colorectal carcinoma. (author)

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

    Witzke, W. R.


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

  2. Dehydrogenation of light alkanes over rhenium catalysts on conventional and mesoporous MFI supports

    Rovik, Anne Krogh; Hagen, Anke; Schmidt, I.;


    Recently, Re/HZSM-5 (Si/Al = 15) was shown to be an efficient catalyst for ethane dehydrogenation and aromatization at 823 K and atmospheric pressure. In this reaction, the major initial products were benzene, toluene and xylene (BTX), but increasing amounts of ethene were produced with time on s...

  3. Crystal structure of fac-aquatricarbonyl[(S-valinato-κ2N,O]rhenium(I

    Kseniia O. Piletska


    Full Text Available In the molecule of the title compound, [Re(C5H10NO2(CO3(H2O], the ReI atom adopts a distorted octahedral coordination sphere defined by one aqua and three carbonyl ligands as well as one amino N and one carboxylate O atom of the chelating valinate anion. The carbonyl ligands are arranged in a fac-configuration around the ReI ion. In the crystal, an intricate hydrogen-bonding system under participation of two O—H, two N—H and one C—H donor groups and the carboxylate and carbonyl O atoms as acceptor groups contribute to the formation of a three-dimensional supramolecular network.

  4. Microstructure and Texture Changes of Tungsten-Rhenium coated on Carbon Fiber Composite during Annealing

    LIUXiang; XUZengyu; S.Tamura; N.Yoshida


    Since tungsten was chose as the divertor tiles of 1TER, the investigation of tungsten and its coating as plasma facing material (PFM) have been paid more attentions by fusion scientists all over the world. Recent years, tungsten coatings have been successfully

  5. Unsymmetrical tren-based ligands: synthesis and reactivity of rhenium complexes.

    Mösch-Zanetti, Nadia C; Köpke, Sinje; Herbst-Irmer, Regine; Hewitt, Manuel


    Reaction of bis(2-aminoethyl)(3-aminopropyl)amine with C(6)F(6) and K(2)CO(3) in DMSO yields unsymmetrical [(C(6)F(5))HNCH(2)CH(2)](2)NCH(2)CH(2)CH(2)NH(C(6)F(5)) ([N(3)N]H(3)). The tetraamine acts as a tridentate ligand in complexes of the type H[N(3)N]Re(O)X (X = Cl 1, Br 2) prepared by reacting Re(O)X(3)(PPh(3))(2) with [N(3)N]H(3) and an excess of NEt(3) in THF. Addition of 1 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 1 gives the dimeric compound H[N(3)N]ClReOReBrCl[N(3)N]H (3) in quantitative yield that contains a Re(V)[double bond]O[bond]Re(IV) core with uncoordinated aminopropyl groups in each ligand. Addition of 2 equiv of TaCH(CMe(2)Ph)Cl(3)(THF)(2) to 1 leads to the chloro complex [N(3)N]ReCl (4) with all three amido groups coordinated to the metal, whereas by addition of 2 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 2 the dibromo species H[N(3)N]ReBr(2) (5) with one uncoordinated amino group is isolated. Reduction of 4 under an atmosphere of dinitrogen with sodium amalgam gives the dinitrogen complex [N(3)N]Re(N(2)) (6). Single-crystal X-ray structure determinations have been carried out on complexes 1, 3, 5, and 6.

  6. Adsorption properties of technetium and rhenium for hybrid microcapsules enclosing Toa extractant

    Wu, Y.; Mimura, H.; Niibori, Y. [Tohoku University, Graduate School of Engineering, Department of Quantum Science and Energy Engineering, Aramaki-Aza-Aoba 6-6-01-2, Aoba-ku, Sendai-shi, Miyagi-ken, 980-8579 Japan (Japan); Koyama, S.; Ohnishi, T., E-mail: [Japan Atomic Energy Agency, O-arai Research and Development Center, Fuels and Materials Department, Alpha-Gamma Section, Narita-cho 4002, O-arai-machi, Ibaraki, 311-1393 Japan (Japan)


    Special attention has been given to the separation and recovery of the VII-group elements Tc and Re, in relation to the partitioning of high-level liquid waste (HLLW) generated from the nuclear fuel reprocessing process. In this study, a tertiary amine (tri-n-octylamine Toa), which is effective for the extraction of oxo anions, was encapsulated in a calcium alginate gel polymer (CaALG), and the adsorption behaviours of TcO{sub 4} and ReO{sub 4}{sup -} in the presence of nitric acid and hydrochloric acid were examined by using calcium alginate microcapsules (M Cs) enclosing Toa extractant (Toa-CaALG M Cs). The order of the distribution coefficient K{sub d} for different oxo anions at 0.1 M HNO{sub 3} was ReO{sub 4}{sup -}> WO{sub 4}{sup 2-}> CrO{sub 4}{sup 2-} {approx} MoO{sub 4}{sup 2-}>> SeO{sub 3}{sup 2-}. Toa-CaALG still exhibited high uptake ability for ReO{sub 4}{sup -} even after irradiation with {sup 60}Co {gamma}-rays (dose: 17.6 kGy). Uptake of TcO{sub 4}{sup -} in the presence of 1 M HNO{sub 3} was readily attained within 3 h. Relatively large K{sub d} values above 10{sup 2} cm{sup 3}/g were obtained for Toa-CaALG in the presence of 0.01 {approx} 1 M HNO{sub 3}. All of the TcO{sub 4}{sup -} was successfully adsorbed by Toa-CaALG from the simulated HLLW. The adsorbed TcO{sub 4}{sup -} was then effectively eluted with 5 M or 7 M HNO{sub 3} solution. Further, the selective uptake of ReO{sub 4}{sup -} (a chemical analogue of TcO{sub 4}{sup -}) was confirmed by using actual HLLW (Fbr, Joyo, JAEA), and uptake (%) above 99% was obtained. Toa-CaALG was thus effective for the selective separation and recovery of TcO{sub 4}{sup -} and ReO{sub 4}{sup -} from waste solutions containing highly concentrated HNO{sub 3} and NaNO{sub 3}. Microencapsulation techniques with alginate gel polymer can be applied to other ion exchangers and extractants, and the M Cs immobilizing these adsorbents are effective for the advanced separation of various radionuclides, rare metals and toxic elements. (Author)

  7. fac-Bromidotricarbonyl[2-(diisopropylphosphanylbenzaldehyde-κ2O,P]rhenium(I

    Christos Apostolidis


    Full Text Available The structure of the title complex, [ReBr(C13H19OP(CO3], displays a facial coordination of the three CO ligands and a κ2O,P coordination mode of the 2-diisopropylphosphinobenzaldehyde ligands. The Re—C bond distance for the CO ligand trans to the P atom is, due to its trans influence, elongated to 1.943 (3 Å, showing that this CO ligand is more weakly bound to the Re centre than the other two.

  8. Impact of triaxiality on the rotational structure of neutron-rich rhenium isotopes

    M.W. Reed


    Full Text Available A number of 3-quasiparticle isomers have been found and characterised in the odd-mass, neutron-rich, 187Re, 189Re and 191Re nuclei, the latter being four neutrons beyond stability. The decay of the isomers populates states in the rotational bands built upon the 9/2−[514] Nilsson orbital. These bands exhibit a degree of signature splitting that increases with neutron number. This splitting taken together with measurements of the M1/E2 mixing ratios and with the changes observed in the energy of the gamma-vibrational band coupled to the 9/2−[514] state, suggests an increase in triaxiality, with γ values of 5°, 18° and 25° deduced in the framework of a particle-rotor model.

  9. Embrittlement of molybdenum-rhenium welds under low and high temperature neutron irradiation

    Krajnikov, A. V.; Morito, F.; Danylenko, M. I.


    The effect of low- and high-temperature neutron irradiation on the tensile strength, microhardness, and fracture mode has been studied for a series of Mo-Re welds with various Re concentrations. Radiation-induced hardening and concurrent ductility reduction are the key after-effects of neutron exposure. Low-temperature irradiation usually leads to a very hard embrittlement. The hardening effect is rather limited and unstable because of the lack of ductility. Irradiated specimens fail by brittle intergranular or transgranular fracture. The damaging effect of neutrons is less pronounced after high-temperature irradiation. The hardening of the matrix is rather high, but irradiated specimens still keep residual plasticity. High-temperature irradiation intensifies homogeneous nucleation of Re-rich phases, and this effect equalises the difference in mechanical properties between the different weld zones. A characteristic ductility loss exposure temperature was found to separate the temperature fields of absolutely brittle and relatively ductile behaviour. It usually varies between 850 K and 1000 K depending on the alloy composition and irradiation conditions.

  10. Analysis of the Nuclear Structure of Rhenium-186 Using Neutron-Induced Reactions


    MeV. In one possible radioisotope power source design, the energetic electrons could produce scintillation light in a crystal that could in turn...scale deflection occurs at E = 4.0 MeV. Because of neutron damage to the semiconductor crystals, some detectors failed to produce usable spectra

  11. Pentavalent rhenium-188 dimercaptosuccinic acid for targeted radiotherapy: synthesis and preliminary animal and human studies

    Blower, P.J. [Nuclear Medicine Department, Kent and Canterbury Hospital, Canterbury (United Kingdom)]|[Department of Biosciences, University of Kent, Canterbury (United Kingdom); Lam, A.S.K. [Department of Biosciences, University of Kent, Canterbury (United Kingdom); O`Doherty, M.J.; Kettle, A.G.; Coakley, A.J. [Nuclear Medicine Department, Kent and Canterbury Hospital, Canterbury (United Kingdom); Knapp, F.F. Jr. [Nuclear Medicine Group, Oak Ridge National Laboratory (ORNL), Oak Ridge, Tenn. (United States)


    The aim of this study was to develop the kit-based synthesis of the agent on a therapeutic scale, to assess its stability in vivo, and to obtain preliminary biodistribution and dosimetry estimates, prior to evaluation of its potential as a targeted radiotherapy agent. The organ distribution of {sup 188}Re in mice was determined 2 h after injection of 3 MBq {sup 188}Re(V)DMSA prepared from eluate from a {sup 188}W/{sup 188}Re generator. Three patients with cancer of the prostate and three with cancer of the bronchus, all with bone metastases, were given 370 MBq {sup 188}Re(V)DMSA and imaged at 3 h and 24 h using the 155-keV {gamma}-photon (15%). Blood and urine samples were collected to determine clearance and to analyse the speciation of {sup 188}Re. Organ residence times were estimated from the scans, and used to estimate radiation doses using MIRDOSE 3. In mice, {sup 188}Re(V)DMSA was selective for bone and kidney. In patients, it showed selectivity for bone metastases (particularly those from prostate carcinoma) and kidney, but uptake in normal bone was not significantly greater than in surrounding soft tissues. Of the normal tissues the kidneys received the highest radiation dose (0.5-1.3 mGy/MBq). The images were strongly reminiscent of {sup 99m}Tc(V)DMSA scans in similar patients. High-performance liquid chromatography analysis of blood and urine showed no evidence of {sup 188}Re in any chemical form other than {sup 188}Re(V)DMSA up to 24 h. In conclusion, {sup 188}Re(V)DMSA and its {sup 186}Re analogue warrant further clinical assessment as generator/kit-derived agents for treatment of painful bone metastases. These agents should also be assessed in medullary thyroid carcinoma and other soft tissue tumours which have been shown to accumulate {sup 99m}Tc(V)DMSA.(orig./MG) (orig.) With 10 figs., 1 tab., 34 refs.

  12. Effect of catalyst pretreatment on the olefin metathesis catalyzed by alumina-supported (9%) rhenium oxide

    Hsu, J.C.


    A kinetic model was developed to express the time-on-stream profile of the activity during catalyst break-in and deactivation. The catalyst surface is in geometric and energetic heterogeneity. Partial catalyst reduction is a prerequisite step for olefin metathesis. The metathesis activity may be affected by the coordination number and the type of ligands associated with the sites on the catalyst. The deactivation is proposed due to deposition of residues on the active sites, and to sintering, etc. A dispersion pretreatment increased activity. Oxygen is an activator. The hydrogen reduction at 500/sup 0/C causes partial but permanent loss of activity.

  13. Towards cancer cell-specific phototoxic organometallic rhenium(I) complexes

    Leonidova, Anna; Pierroz, Vanessa; Rubbiani, Riccardo; Heier, Jakob; Ferrari, Stefano; Gasser, Gilles


    Over the recent years, several Re(i) organometallic compounds have been shown to be toxic to various cancer cell lines. However, these compounds lacked sufficient selectivity towards cancer tissues to be used as novel chemotherapeutic agents. In this study, we probe the potential of two known N,N-bis(quinolinoyl) Re(i) tricarbonyl complex derivatives, namely Re(i) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-4-butane-1-amine () and Re(i) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-5-va...

  14. Towards cancer cell-specific phototoxic organometallic rhenium(I) complexes.

    Leonidova, Anna; Pierroz, Vanessa; Rubbiani, Riccardo; Heier, Jakob; Ferrari, Stefano; Gasser, Gilles


    Over the recent years, several Re(I) organometallic compounds have been shown to be toxic to various cancer cell lines. However, these compounds lacked sufficient selectivity towards cancer tissues to be used as novel chemotherapeutic agents. In this study, we probe the potential of two known N,N-bis(quinolinoyl) Re(I) tricarbonyl complex derivatives, namely Re(I) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-4-butane-1-amine (Re-NH₂) and Re(I) tricarbonyl [N,N-bis(quinolin-2-ylmethyl)amino]-5-valeric acid (Re-COOH), as photodynamic therapy (PDT) photosensitizers. Re-NH₂ and Re-COOH proved to be excellent singlet oxygen generators in a lipophilic environment with quantum yields of about 75%. Furthermore, we envisaged to improve the selectivity of Re-COOH via conjugation to two types of peptides, namely a nuclear localization signal (NLS) and a derivative of the neuropeptide bombesin, to form Re-NLS and Re-Bombesin, respectively. Fluorescent microscopy on cervical cancer cells (HeLa) showed that the conjugation of Re-COOH to NLS significantly enhanced the compound's accumulation into the cell nucleus and more specifically into its nucleoli. Importantly, in view of PDT applications, the cytotoxicity of the Re complexes and their bioconjugates increased significantly upon light irradiation. In particular, Re-Bombesin was found to be at least 20-fold more toxic after light irradiation. DNA photo-cleavage studies demonstrated that all compounds damaged DNA via singlet oxygen and, to a minor extent, superoxide production.

  15. Electronic structure and superconductivity of hcp-bcc binary systems based on titanium and rhenium

    Prekul, A.F.; Volkenshtein, N.V.


    The similarity of hcp--bcc binary systems of transition metals of groups IV--V and VI--VII is shown on the basis of a joint analysis of the kinetic, superconducting, and structural properties. Under the assumption that there is a singularity (a pseudo-gap) in the electronic structure of hardened alloys, a model is proposed for the change in the critical temperature of superconductivity with alloy concentration. According to the model, the two peaks in the functions T/sub c/(x) are due to the partial dielectrization of the electron spectrum and do not belong to the equilibrium solid solutions based on the initial metals, as had earlier been assumed.

  16. Suppression of radiation-induced point defects by rhenium and osmium interstitials in tungsten

    Suzudo, Tomoaki; Hasegawa, Akira


    Modeling the evolution of radiation-induced defects is important for finding radiation-resistant materials, which would be greatly appreciated in nuclear applications. We apply the density functional theory combined with comprehensive analyses of massive experimental database to indicate a mechanism to mitigate the effect of radiation on W crystals by adding particular solute elements that change the migration property of interstitials. The resultant mechanism is applicable to any body-centered-cubic (BCC) metals whose self-interstitial atoms become a stable crowdion and is expected to provide a general guideline for computational design of radiation-resistant alloys in the field of nuclear applications.

  17. Suppression of radiation-induced point defects by rhenium and osmium interstitials in tungsten

    Suzudo, Tomoaki; Hasegawa, Akira


    Modeling the evolution of radiation-induced defects is important for finding radiation-resistant materials, which would be greatly appreciated in nuclear applications. We apply the density functional theory combined with comprehensive analyses of massive experimental database to indicate a mechanism to mitigate the effect of radiation on W crystals by adding particular solute elements that change the migration property of interstitials. The resultant mechanism is applicable to any body-centered-cubic (BCC) metals whose self-interstitial atoms become a stable crowdion and is expected to provide a general guideline for computational design of radiation-resistant alloys in the field of nuclear applications. PMID:27824134

  18. Rhenium Uptake, as Analogue for Tc-99, by Steel Corrosion Products

    Krupka, Kenneth M.; Brown, Christopher F.; Schaef, Herbert T.; Heald, Steve M.; Valenta, Michelle M.; Arey, Bruce W.


    Static batch experiments were used to examine the sorption of dissolved perrhenate [Re(VII)], as a surrogate for pertechnetate [Tc(VII)], on corrosion products of A-516 carbon steel coupons contacted with synthetic groundwater or dilute water. After 109 days of contact time, the concentration of dissolved Re(VII) in the synthetic groundwater matrix decreased by approximately 26%; the dilute water matrix experienced a 99% decrease in dissolved Re(VII) over the same time period. Bulk XRD results for the corroded steel coupons showed that the corrosion products consisted primarily of maghemite, lepidocrocite, and goethite. Analyses of the coupons by SEM/EDS indicated that Re was present with the morphologically complex assemblages of Fe oxide/hydroxide corrosion products for samples spiked with the highest dissolved Re(VII) concentration (1.0 mmol/L) used for these experiments. Analyses of corroded steel coupons contacted with solutions containing 1.0 mmol/L Re(VII) by synchrotron-based methods confirmed the presence of Re sorbed with the corrosion product on the steel coupons. Analyses showed that the Re sorbed on these corroded coupons was in the +7 oxidation state, suggesting that the Re(VII) uptake mechanism did not involve reduction of Re to a lower oxidation state, such as +4. The results of our studies using Re(VII) as an analogue for Tc(VII)-99 suggest that Tc(VII)-99 would also be sorbed with steel corrosion products and that the inventory of Tc(VII)-99 released from breached waste packages would be lower than what is now conservatively estimated.

  19. Rhenium-mediated coupling of acetonitrile and pyrazoles. New molecular clefts for anion binding.

    Arroyo, Marta; Miguel, Daniel; Villafañe, Fernando; Nieto, Sonia; Pérez, Julio; Riera, Lucía


    The reaction of fac-[ReBr(CO)3(NCMe)2] (1) with either pyrazole (Hpz) or 3,5-dimethylpyrazole (Hdmpz) in a 1:2 Re/pyrazole ratio affords the known complexes fac-[ReBr(CO)3(Hpz)2] (2) and [ReBr(CO)3(Hdmpz)2] (3). Using a 1:1 ratio, MeCN as solvent, and longer reaction times led to a mixture in which the major components are the pyrazolylamidino complexes fac-[ReBr(CO)3(HN=C(CH3)pz-kappa2N,N)] (4) and fac-[ReBr(CO)3(HN=C(CH3)dmpz-kappa2N,N)] (5). The complexes fac-[ReBr(CO)3(Hpz)(NCMe)] (6) and fac-[ReBr(CO)3(Hdmpz)(NCMe)] (7) (along with 2 and 3) were found to be minor components of these reactions. Analogous reactions of fac-[Re(OClO3)(CO)3(NCMe)2] yielded fac-[Re(NCCH3)(CO)3(HN=C(CH3)pz-kappa2N,N)]ClO4 (8), fac-[Re(NCCH3)(CO)3(HN=C(CH3)dmpz-kappa2N,N)]ClO4 (9), fac-[Re(Hpz)(CO)3(HN=C(CH3)pz-kappa2N,N)]ClO4 (10), and fac-[Re(Hdmpz)(CO)3(HN=C(CH3)dmpz-kappa2N,N)]ClO4 (11). The X-ray structure of 11 showed the perchlorate anion to be hydrogen-bonded by the N-H groups of the pyrazole and pyrazolylamidino ligands. The behavior of the compound fac-[Re(Hdmpz)(CO)3(HN=C(CH3)dmpz-kappa2N,N)]BAr'4 (13) (synthesized by reaction of [ReBr(CO)3(Hdmpz)2] (3) with (i) AgOTf and (ii) NaBAr'(4)/MeCN) as an anion receptor has been studied in CD3CN solution. In addition, the structure of the supramolecular adduct fac-[Re(CO)3(Hdmpz)(HN=C(CH3)dmpz-kappa2N,N)].Cl (14), featuring chloride binding by the two N-H groups, was determined by X-ray diffraction.

  20. Luminescent rhenium(I) tricarbonyl complexes with pyrazolylamidino ligands: photophysical, electrochemical, and computational studies.

    Gómez-Iglesias, Patricia; Guyon, Fabrice; Khatyr, Abderrahim; Ulrich, Gilles; Knorr, Michael; Martín-Alvarez, Jose Miguel; Miguel, Daniel; Villafañe, Fernando


    New pyrazolylamidino complexes fac-[ReCl(CO)3(NH[double bond, length as m-dash]C(Me)pz*-κ(2)N,N)] (pz*H = pyrazole, pzH; 3,5-dimethylpyrazole, dmpzH; indazole, indzH) and fac-[ReBr(CO)3(NH[double bond, length as m-dash]C(Ph)pz*-κ(2)N,N)] are synthesized via base-catalyzed coupling of the appropriate nitrile with pyrazole, or via metathesis by halide abstraction with AgBF4 from a bromido pyrazolylamidino complex and the subsequent addition of LiCl. In order to study both the influence of the substituents present at the pyrazolylamidino ligand, and that of the "sixth" ligand in the complex, photophysical, electrochemical, and computational studies have been carried out on this series and other complexes previously described by us, of the general formula fac-[ReL(CO)3(NH[double bond, length as m-dash]C(R')pz*-κ(2)N,N)](n+) (L = Cl, Br; R' = Me, Ph, n = 0; or L = NCMe, dmpzH, indzH, R' = Me, n = 1). All complexes exhibit phosphorescent decays from a prevalently (3)MLCT excited state with quantum yields (Φ) in the range between 0.007 and 0.039, and long lifetimes (τ∼ 8-1900 ns). The electrochemical study reveals irreversible reduction for all complexes. The oxidation of the neutral complexes was found to be irreversible due to halido-dissociation, whereas the cationic species display a reversible process implying the ReI/ReII couple. Density functional and time-dependent density functional theory (TD-DFT) calculations provide a reasonable trend for the values of emission energies in line with the experimental photophysical data, supporting the (3)MLCT based character of the emissions.

  1. Pyridine ring opening at room temperature at a rhenium tricarbonyl bipyridine complex.

    Huertos, Miguel A; Pérez, Julio; Riera, Lucía


    Pyridine ring opening occurs in the reaction of [Re(CO)3(MeIm)(bipy)]OTf with KN(SiMe3)2 followed by double methylation with methyl trifluoromethanesulfonate. Analogues of the neutral product of the initial deprotonation and of the product of the first methylation were isolated by using mesitylimidazole (MesIm) in place of methylimidazole (MeIm) and/or 1,10-phenanthroline (phen) instead of 2,2'-bipyridine (bipy).

  2. Imidazole-nitrile or imidazole-isonitrile C-C coupling on rhenium tricarbonyl complexes.

    Viguri, Maialen Espinal; Huertos, Miguel A; Pérez, Julio; Riera, Lucía


    Ligand activation: Deprotonation of the nitrile or isonitrile complexes [Re(CO)3(N-RIm)2(L)](+) (N-RIm = N-alkylimidazole; L = N≡CtBu, C≡NtBu) selectively afforded alkylidenamido or iminoacyl derivatives, respectively, in which C-C coupling has occurred. Protonation of the latter complex leads to aminocarbene products.

  3. Influence of Yttrium and Ytterbium on Reaction Performance of Platinum-Rhenium Reforming Catalyst


    The influence of yttrium and ytterbium on the catalytic performance of Pt-Re reforming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit. Theresults of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Recatalysts for the conversion ofn-heptane as well as MCP into aromatics, but also suppressed their activityas well. Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity ofPt-Re catalysts for naphtha reforming. Yttrium showed more improvement than ytterbium. The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement ofcatalytic stability of yttrium or ytterbium modified Pt-Re catalysts. Yttrium and ytterbium improved thecoking resistance of yttrium or ytterbium modified Pt-Re catalysts. TEM determination results indicatedthat both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.

  4. Nuclear Structure of Rhenium-186 Revealed by Neutron-Capture Gamma Rays


    the non-forbidden transition probabilities, are assumed to follow a Porter -Thomas distribution [21] and its center lies on a mean value given by...rectangles are processing steps and the amber diamond is the conditional or decision point. The remainder of this section will briefly elaborate on...C. E. Porter and R. G. Thomas, "Fluctuations of Nuclear Reaction Widths," Phys. Rev., vol. 104, no. 2, p. 483, 1956. [22] S. Hilaire, "Level

  5. Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

    Knapp, F.F. Jr.; Lisic, E.C.; Mirzadeh, S.; Callahan, A.P.


    A generator system has been invented for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form. 1 figure.

  6. Tungsten-zirconium carbide-rhenium alloys with extraordinary thermal stability

    Yang, X.D. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xie, Z.M.; Miao, S. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Liu, R.; Jiang, W.B. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhang, T., E-mail: [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, X.P., E-mail: [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Fang, Q.F. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Liu, C.S., E-mail: [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, X. [Southwest Institute of Plasma Physics, Chengdu (China)


    The low recrystallization temperature (1200 °C) of pure W is a serious limitation for application as facing plasma materials in fusion reactor. In this paper, W-0.5wt.%ZrC-1wt.%Re (WZR) alloy with recrystallization temperature up to 1800 °C was prepared by mechanical milling and spark plasma sintering. The grain size of WZR alloy is about 2.6 μm, smaller than that of pure W (4.4 μm), which keeps unchanged until the annealing temperature increases to 1800 °C. Tensile tests indicate that the WZR alloys exhibit excellent comprehensive properties: the ductile to brittle transition temperature of WZR is in the range from 400 °C to 500 °C, about 200 °C lower than that of pure W prepared by the same process; the total elongation (TE) of WZR at 600 °C is above 30%, which is about 2 times that of pure W (at 700 °C). Meanwhile its tensile strength keeps ∼450 MPa before and after 1800 °C annealing as well as its TE increases after annealing. WZR alloy exhibits higher hardness (489HV) than that of pure W (453HV) at room temperature. Microstructure analysis indicates that the strengthening of nano-sized ZrC particles dispersion and Re solid solution improve tensile properties and thermal stability of WZR alloy.

  7. High Temperature Corrosion of Fe-C-S Cast Irons in Oxidizing and Sulfidizing Atmospheres

    Thuan-Dinh NGUYEN; Dong-Bok LEE


    The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Feo.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.

  8. Portal vein thrombosis with protein C-S deficiency in a noncirrhotic patient

    Gustavo; A; Rodríguez-Leal; Segundo; Morán; Roberto; Corona-Cedillo; Rocío; Brom-Valladares


    There are several conditions that can lead to portal vein thrombosis(PVT), including including infection, malignancies, and coagulation disorders. Anew condition of interest is protein C and S deficiencies, associated with hypercoagulation and recurrent venous thromboembolism. We report the case of a non-cirrhotic 63-year-old male diagnosed with acute superior mesenteric vein thrombosis and PVT and combined deficiencies in proteins C and S, recanalized by short-term low molecular heparin plus oral warfarin therapy.

  9. Science and technique in the anti-science fiction of C. S. *Lewis

    Campo Ricardo Burgos López


    Full Text Available The article analyzes the image of Western science and technology (and by extension of civilization in which they are prominent, that put CS Lewis’s Cosmic Trilogy (classic of fantasy literature and religion of the twentieth century. In the scientific-technical culture now prevailing in these three novels, Lewis proposes a civilization rooted in Christianity. Faced with a scientific-technical culture to promote the dehumanization just the discrimination of humans and nonhumans, new forms of alienation and, ultimately, opposed to wisdom, Lewis bet the alternative of a return to Christ. Such a return to Christ is also the return to wisdom, and thus opting for a path leading to full humanization.

  10. Pärt: Fratres in sechs Versionen. Festina lente. Summa / C. S.

    C. S.


    Uuest heliplaadist "Pärt: Fratres in sechs Versionen. Festina lente. Summa. Cantus in memoriam Benjamin Britten. Orchester der Ungarischen Staatsoper, Tamas Benedek". Naxos CD 8 553 750 (WD:79'06") DDD

  11. The China Studies Programs of U.B.C.'s Center for Continuing Education

    Woodsworth, K. C.


    Program will cover Contemporary Chinese History, Society, and Politics; Chinese Language; Doing Business with China; A China Educational Travel Program. The program combines professional and general public areas. (NL)

  12. New Leaders for Troubled Schools: Jacquelyn Davis Works with D.C.'s Education Bureaucracy

    Currie, Tyler


    In this article the author presents Jacquelyn Davis, the executive director of the Washington office of New Leaders for New Schools (NLNS), a nonprofit dedicated to training recruits drawn from a range of sectors for leadership in failing school systems. Davis is overseeing a rapidly expanding crop of new principals who are promising to revitalize…

  13. Musical listening and abductive reasoning: Contributions of C.S. Peirce’s

    Oliveira, L.F.; Haselager, W.F.G.; Manzolli, J.; Gonzalez, M.E.Q.


    Background in music philosophy. Questions about musical meaning are usually discussed within the area of philosophy of music. These questions gained particular urgencyin the Modern Age, when music had lost its connection with the old cosmologies that assured its position among the other disciplines

  14. Pastoreo del microzooplancton en la Ensenada de la Paz, B.C.S., México

    Gabriela María Esqueda-Escárcega


    Full Text Available Se analizó el crecimiento de fitoplancton y la tasa de pastoreo del microzooplancton in situ, en una estación fija de muestreo de octubre de 2007 a agosto de 2008, en la Ensenada de La Paz, México, utilizando el método de dilución. La tasa aparente de crecimiento de fitoplancton fue mayor en diciembre con 1,33 d-1 y menor en octubre con 0,35 d-1. La tasa de pastoreo fue máxima en abril con 0,86 d-1 y mínima en febrero y agosto con 0,38 d-1. La presión de pastoreo, medida como el porcentaje de la producción potencial removida (%PPR fluctuó entre 28 y 76%. La relación entre crecimiento de fitoplancton y la tasa de pastoreo indica que la producción de clorofila-α es consumida aproximadamente en un 50%, implicando otros procesos causantes de mortalidad del fitoplancton, como la tasa de sedimentación y pastoreo por mesozooplancton. El hallazgo de pastoreo moderado en otoño y un evidente crecimiento, y consumo en el invierno son características que requieren de monitoreo en escalas temporales y espaciales de mayor envergadura.

  15. Consciousness and C. S. Peirce’s Answer to the Riddle of the Sphinx

    Brier, Søren


    Husserl wrote that the beginning of Galilean science where models are related to a mathematical ideal world changed the role of philosophy as the queen of all sciences fundamentally. Positivism and analytical philosophy later tried to get rid of all traditional metaphysical thinking of the meaning...... definition of information. But this physicalist and informationalist paradigm is theoretically unable to encompass the conscious experience and existential meaning that are the basic requirements for producing science. Thus a scientific explanation of consciousness that is not partially based...... some of the first to integrate Eastern philosophy in their thinking). But there was a split between the empiricist and intuitionist view of knowledge among them. Peirce through his pragmaticist semiotics suggested a way to unite these two hostile epistemologies. Peirce attempts a new way of answering...

  16. Pärt: Fratres in sechs Versionen. Festina lente. Summa / C. S.

    C. S.


    Uuest heliplaadist "Pärt: Fratres in sechs Versionen. Festina lente. Summa. Cantus in memoriam Benjamin Britten. Orchester der Ungarischen Staatsoper, Tamas Benedek". Naxos CD 8 553 750 (WD:79'06") DDD

  17. C.S. 211 Bilingual Gifted and Talented Program. Final Evaluation Report, 1979-80.

    Brumberg, Stephan F.; Toledo, Victor

    This Title VII Bilingual Gifted and Talented Program was conducted in a community school district in New York City in 1979-80. The program served Hispanic students in grades K-6. A description of the school and the rationale for the program are presented, and program objectives are discussed. These are grouped in three major areas: (1) the…

  18. Understanding Knowledge through the Example of C. S. Peirce’s Cosmology

    Enn Kasak


    Full Text Available In the era of Charles Sanders Peirce, cosmology was similar to philosophy that was still aspiring to be scientific. Peirce, having worked as an astrophysicist, supported cosmology’s strive towards science. In cosmology, one often relies on knowledge different from everyday knowledge: such knowledge is very general and is situated on the boundaries of what is known; it is very difficult to ascertain it empirically. After Karl Popper, a realist may distinguish between subjective and objective knowledge but this distinction does not suffice for cosmology. A pragmaticist following Peirce could distinguish knowledge about real ideas, which could be termed i-knowledge. This could mean being made party to or being grasped by real ideas functioning outside ourselves. Expressing all i-knowledge as propositional knowledge is difficult. However, non-propositional i-knowledge can sometimes be expressed as principles or paradoxically.

  19. Embarazo en adolescentes caso del S.C.S. de Mulalillo enero a julio 2014

    De La Vega Espín, Angélica Carolina


    El embarazo en adolescentes es un tema que requiere más educación y apoyo para alentar a las niñas a retrasar la maternidad hasta que estén preparadas. Existen factores determinantes que influyen en la presencia de altos índices de embarazos en adolescente en cada país. Se estima que 16 millones de niñas de edades comprendidas entre los 15 y los 19 años dan a luz cada año, y un 95% de esos nacimientos se producen en países en desarrollo, según el estudio realizado por Rosen. Esto represent...

  20. Musical listening and abductive reasoning: Contributions of C.S. Peirce’s

    Oliveira, L.F.; Haselager, W.F.G.; Manzolli, J.; Gonzalez, M.E.Q.


    Background in music philosophy. Questions about musical meaning are usually discussed within the area of philosophy of music. These questions gained particular urgencyin the Modern Age, when music had lost its connection with the old cosmologies that assured its position among the other disciplines

  1. Research of Efficient C/S Model Based File Transfer Method

    Li, Xubin; Zou, Quan; Jiang, Yi

    The one-to-multiple file transfer problem has not been solved under the Linux system. In this paper, we take socket programming to accomplish Client/Server model based file transfer system and develop efficient software which not only support multiple clients and files transferring simultaneously, but also support transmission resuming from breakpoint. Our research focuses on solving the multi-thread concurrency, transmission resuming from breakpoint, thread pool, buffer queue and other aspects of problem. Our work is the basic foundation of FTP servers, file transfer software in local area network and large-scale examination system, etc.

  2. Role of TBATB in nano indium oxide catalyzed C-S bond formation

    Gogoi, Prasanta; Hazarika, Sukanya; Barman, Pranjit


    Nano sized indium oxide is found to be an efficient catalyst for the conversion of thiols to sulfides using Na2CO3 as base and TBATB as reagent in DMSO at 110 °C. Here in situ generation of bromo intermediate by TBATB takes place through indium surface. A variety of aryl sulfides can be synthesized in excellent yields from less reactive chlorides, boronic acids and thiols.

  3. Creep of a C-S-H gel: a micromechanical approach

    Julien Sanahuja


    Full Text Available Both clays and calcium silicate hydrates(the main hydration products of Portland cements exhibit a microstructure made up of lamellar particles. The microscopic mechanism responsible for the macroscopic creep of such materials is often described as the relative sliding of the sheets. This paper proposes a micromechanical approach to estimate the macroscopic creep behavior rising from this microscopic mechanism. The asymptotic evolution of creep at both short- and long-term is especially investigated. More precisely, a non-vanishing initial elastic strain is retrieved. At long-term, a threshold on porosity appears. At lower porosities, the creep evolution admits an asymptotic strain. At higher porosities, it admits an asymptotic strain rate.Argilas e hidratos de cálcio (principal produto de cimentos ambos exibem microestrutura composta por partículas em forma de lamelas. O principal mecanismo responsável pelo fenômeno de fluência macroscópico é frequentemente descrito pelo deslizamento entre as lamelas. O artigo propõe uma abordagem micromecânica para estimar a fluência macroscópica que surge a partir do mecanismo microscópico. A evolução assintótica da fluência para tempos curtos e longos é especialmente investigada. Mais precisamente uma tensão inicial não nula é derivada. Para tempos longos um limiar de porosidade surge da modelagem. Na faixa de porosidades mais baixas a evolução da fluência admite deformação assintótica. Para porosidades altas o problema admite taxa de deformação assintótica.

  4. Systemic application of rhenium-186 hydroxyethylidenediphosphonate ({sup 186}Re HEDP) as an option for the treatment of chronic arthritis and arthropathy[Radiosynoviorthesis]; Systemische Applikation von Rhenium-186 Hydroxyethylidendiphosphonat ({sup 186}Re HEDP) als Therapieoption bei chronischen Arthritiden und Arthropathien

    Bucerius, J.; Biersack, H.J.; Palmedo, H. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Bonn (Germany); Wallny, T. [Orthopaedische Klinik l, Klinik fuer Orthopaedische Chirurgie, St. Bernhard-Hospital Kamp-Lintfort (Germany); Klinik und Poliklinik fuer Orthopaedie, Universitaetsklinikum Bonn (Germany); Brackmann, H.H. [Inst. fuer experimentelle Haematologie und Transfusionsmedizin, Universitaetsklinikum Bonn (Germany)


    Chronic arthritis is very common and is associated with a variety of systemic diseases whereas hemophilic arthropathy is one of the most common clinical manifestations of hemophilia, mainly of hemophilia type A. All of these polyarticular diseases are associated with progressive pain and increasing lack of mobility. Therapy is based on conservative treatment such as medication with non-steroidal anti-inflammatory drugs, selective therapy strategies such as intraarticular injections of e.g. radioactive substances (radiosynoviorthesis) or surgical interventions. However, in some cases, the disease does not respond to one of these treatment options or cannot be continued due to important side-effects. Systemic application of radioisotopes like {sup 186}Re HEDP has been successfully administered for pain palliation of osseous metastases. Today, only few data exist for systemic therapy with {sup 186}Re HEDP in patients suffering from benign polyarticular disease. In a prospective study with patients suffering from chronic arthritis a single systemic application of {sup 186}Re HEDP led to a reduction of disease activity in six of eight and to a reduction of the number of painful or swollen joints in five of eight included patients. In a further prospective study with 12 patients with hemophilic arthropathy, 19 of 36 (52.7%) most painful joints could be successfully treated with one systemic {sup 186}Re HEDP therapy. Furthermore, a reduction of global pain could be observed in those patients. However, further randomized studies with larger study populations are necessary in order to confirm this promising results. (orig.)

  5. Electron Tunneling Studies of MOLYBDENUM(1-X) Rhenium(x): Enhancement of Superconductivity by a Resonance Mode.

    Shum, Danny Pak-Chum

    It is well-known that a heavy impurity atom in a lattice of light atoms induces a lower frequency in-band resonance mode in the vibrational spectrum. The exact effect of such a mode on the lat- tice spectrum has not previously been reported and effects of such modes on superconductivity have not previously been described. Sputtered thin films of bcc Mo(,1-x)Re(,x), 0.2 0. (delta) increases with (lamda)(,R), the Re contribution to the electron-phonon coupling con- stant (lamda). The dependences of the anomalous softening and width of the resonance mode on (lamda)(,R) fit the Yu-Anderson theory of local pho- non screening by a Fermi gas of electrons treated as Tomonago. bosons. These results explain the low N(0), high T(,c) behavior of Mo(,.6)Re(,.4). *DOE Report IS-T-1246. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy.

  6. Quantum chemical interpretation of ultrafast luminescence decay and intersystem crossings in rhenium(I) carbonyl bipyridine complexes.

    Gourlaouen, Christophe; Eng, Julien; Otsuka, Miho; Gindensperger, Etienne; Daniel, Chantal


    Ultrafast luminescence decay and intersystem crossing processes through the seven low-lying singlet and triplet excited states of [Re (X)(CO)3(bpy)] (X = Cl, Br, I; bpy = 2,2'-bipyridine) are interpreted on the basis of time-dependent density functional theory (TD-DFT) electronic structure calculations performed in acetonitrile and including spin-orbit coupling (SOC) effects within the zeroth-order approximation. It is shown that the red shift of the lowest part of the spectra by SOC increases from X = Cl (0.06 eV) to X = Br (0.09 eV) and X = I (0.18 eV) due to the participation of the triplet sublevels to the absorption. The six lowest "spin-orbit" states remain largely triplet in character and the maximum of absorption is not drastically affected by SOC. While the energy of the excited states is affected by SOC, the character of these states is not significantly modified: SOC mixes states of the same nature, namely metal-to-ligand-charge-transfer/halide-to-ligand-charge-transfer (MLCT/XLCT). This mixing can be large, however, as illustrated by the S1/T2 (a(1)A″/a(3)A') mixing that amounts to about 50:50 within the series Cl > Br > I. On the basis of the optimized structures of the six lowest excited states an interpretation of the emission signals detected by ultrafast luminescence spectroscopy is proposed. It is shown that whereas the experimental Stokes shift of 6000 cm(-1) observed for the three complexes is well reproduced without SOC correction for the Cl and Br complexes, SOC effects have to be taken into account for the iodide complex. The early signal of ultrafast luminescence detected immediately after absorption at 400 nm to the S2 state, covering the 500-550 nm energy domain and characterized by a decay τ1 = 85 fs (X = Cl) and 128 fs (X = Br), is attributed to S2 calculated at 505 and 522 nm, respectively, and to some extend to T3 by SOC. The intermediate band observed at longer time-scale between 550 and 600 nm with emissive decay time τ2 = 340 fs (X = Cl) and 470 fs (X = Br) can be assigned to T2 calculated at 558 and 571 nm, respectively. The S1 state could also participate to this band by SOC. In both complexes the long-lived emission at 600-610 nm is attributed to the lowest T1 state calculated at 596 and 592 nm for the chloride and bromide complexes, respectively, and shifted to ∼610 nm by SOC. Important SOC effects characterize the luminescence decay of [Re (I)(CO)3(bpy)], the mechanism of which differs significantly of the one proposed for the two other complexes. The A' spin-orbit sublevel of T3 state calculated at 512 nm with an oscillator strength of 0.17 × 10(-1) participates to the first signal characterized by a rapid decay (τ1 = 152 fs) with a maximum at 525 nm. The intermediate band covering the 550-600 nm region with a decay time τ2 = 1180 fs is assigned to the "spin-orbit" S1 state calculated at 595 nm. The S2 absorbing state calculated at 577 nm could contribute to these two signals. According to the spin-orbit sublevels calculated for T1 and T2, both states contribute to the long-lived emission detected at 600-610 nm, T1 with two sublevels A' of significant oscillator strengths of ∼10(-1) being the main contributor. In order to follow the evolution of the excited states energy and SOC as a function of the Re-X stretching normal mode their potentials have been calculated without and with SOC as a function of the mass and frequency weighted Re-X stretching mode displacement from the Franck-Condon geometries. Exploratory wavepacket propagations show that SOC alone cannot account for the whole ISC process. Vibronic effects should play an important role in the ultrafast luminescence decay observed experimentally.

  7. Cyclopentadienyl-based Trioxo-rhenium Complexes for the Catalytic Deoxydehydration of Diols and Bio-based Polyols to Olefins

    Raju, S.


    Renewable sources like biomass, which mainly consists of materials derived from trees and plants, are currently considered as a key and future feedstock in the chemical industry for the sustainable production of chemicals. After the pre-treatment of biomass, lignocellulosic biomass is obtained as th

  8. Rhenium(IV)-copper(II) heterobimetallic complexes with a bridge malonato ligand. Synthesis, crystal structure, and magnetic properties.

    Cuevas, Alicia; Chiozzone, Raúl; Kremer, Carlos; Suescun, Leopoldo; Mombrú, Alvaro; Armentano, Donatella; De Munno, Giovanni; Lloret, Francesc; Cano, Juan; Faus, Juan


    The Re(IV) complex [ReCl4(mal)]2-, in the form of two slightly different salts, (AsPh4)1.5(HNEt3)0.5[ReCl4(mal)] (1a) and (AsPh4)(HNEt3)[ReCl4(mal)] (1b), and the Re(IV)-Cu(II) bimetallic complexes [ReCl4(mu-mal)Cu(phen)2].CH3CN (2), [ReCl4(mu-mal)Cu(bpy)2] (3), and [ReCl4(mu-mal)Cu(terpy)] (4) (mal=malonate dianion, AsPh4=tetraphenylarsonium cation, HNEt3=triethylammonium cation, phen=1,10-phenanthroline, bpy=2,2'-bipyridine and terpy=2,2':6',2' '-terpyridine) have been synthesized and the structures of 1a, 1b, 2, and 3 determined by single-crystal X-ray diffraction. The structures of 1a and 1b are made up of discrete [ReCl4(mal)]2- anions and AsPh4+ and HNEt3+ cations, held together by electrostatic forces and hydrogen bonds. The Re(IV) atom is surrounded by four chloride anions and a bidentate malonate group, in a distorted octahedral environment. The structure of 2 consist of neutral dinuclear units [ReCl4(mu-mal)Cu(phen)2], with the metal ions united through a bridge carboxilato. The environment of Re(IV) is nearly identical to that in the mononuclear complex, and Cu(II) is five coordinate, being surrounded by four nitrogen atoms of two bidentate phen ligands and one oxygen atom of the malonato ligand. In 3, there are also dinuclear units, [ReCl4(mu-mal)Cu(bpy)2], but the Cu(II) ions complete a distorted octahedral coordination by binding with the free malonato oxygen atom of a neighbor unit, resulting in an infinite chain. The magnetic properties of 1-4 were also investigated in the temperature range 2.0-300 K. The magnetic behavior of 1a and 1b is as expected for a Re(IV) complex with a large value of the zero-field splitting (2D ca. 110 cm(-1)). For the bimetallic complexes, the magnetic coupling between Re(IV) and Cu(II) is antiferromagnetic in 2 (J=-0.39 cm(-1)), ferromagnetic in 4 (J=+1.51 cm(-1)), and nearly negligible in 3 (J=-0.09 cm(-1)).

  9. Temperature dependent emission properties of rhenium(I) tricarbonyl complexes containing alkyl- and aryl-substituted phenanthrolines as ligands

    Wallace, L.; Jackman, D.C.; Rillema, D.P.; Merkert, J.W. [Univ. of North Carolina, Charlotte, NC (United States)


    The results of the temperature dependence in fluid solution of the emission behavior of a series of [Re(L-L)-(CO){sub 3}py]{sup +} complexes (L-L = 3,4,7,8-Me{sub 4}phen, 4,7-Ph{sub 2}phen, 2,9-Me{sub 2}-4,7-Ph{sub 2}phen, 4,7-Me{sub 2}phen, 5,6-Me{sub 2}phen, 5-Phphen, 2,9-Me{sub 2}phen, and phen) are presented along with an interpretation which assigns the lowest excited state as {sup 3}MLCT, with a contribution from a higher-energy, shorter-lived state of unknown character. The emission lifetime of [Re(3,4,7,8-Me{sub 4}phen)(CO){sub 3}py]{sup +} actually increases with temperature, reaches a maximum at approximately 230 K, and then decreases in the usual manner. This behavior is attributed to population of the lowest {sup 3}LC state, which in this complex lies just above the {sup 3}MLCT emitting state and below the upper state.

  10. Ductile Tungsten-Rhenium Coating for Long-Term Protection of Nuclear-Thermal Rocket Fuel Project

    National Aeronautics and Space Administration — In conjunction with Sandia National Laboratories, Ultramet previously demonstrated the feasibility of using low-density, high specific stiffness open-cell foams for...

  11. Solid state molecular device based on a rhenium(I) polypyridyl complex immobilized on TiO2 films.

    Patrocinio, Antonio Otavio T; Frin, Karina P M; Murakami Iha, Neyde Y


    The photochemical and photophysical behaviors of fac-[Re(CO)3(phen)(trans-stpyCOOH)](+) (phen = 1,10-phenanthroline, trans-stpyCOOH = 4-[trans-(pyridin-4-yl-vinyl)]benzoic acid) in acetonitrile solution and adsorbed on a TiO2 film have been investigated. The trans-to-cis photoisomerization at 404 nm irradiation of coordinated stpyCOOH occurs efficiently in fluid solution as shown by quantum yield determined spectrophotometrically (Φ(UV-vis) = 0.37 ± 0.04) and, more accurately, by (1)H NMR (Φ(NMR) = 0.48 ± 0.04), following the photoproduct signals in the distinct region of the reactant. For the first time, the trans-to-cis isomerization is also reported for the complex adsorbed on the TiO2 surface (Φ(UV-vis) = 0.23 ± 0.03). The photoproduct, fac-[Re(CO)3(phen)(cis-stpyCOOH)](+), is emissive in acetonitrile (ϕ = 0.032), but its radiative decay is highly quenched on the oxide surface by electron photoinjection into the semiconductor, leading to an increasing photocurrent as the trans-to-cis isomerization takes place. Therefore, the photoinduced trans-to-cis isomerization of coordinated ligand immobilized on TiO2 films acts as a trigger for the electron injection process. This system exemplifies the use of photoinduced molecular motion to yield electrical current, which can be used as a "proof of concept" for molecular machines/devices.

  12. Accuracy of Rhenium-188 SPECT/CT activity quantification for applications in radionuclide therapy using clinical reconstruction methods

    Esquinas, Pedro L.; Uribe, Carlos F.; Gonzalez, M.; Rodríguez-Rodríguez, Cristina; Häfeli, Urs O.; Celler, Anna


    The main applications of 188Re in radionuclide therapies include trans-arterial liver radioembolization and palliation of painful bone-metastases. In order to optimize 188Re therapies, the accurate determination of radiation dose delivered to tumors and organs at risk is required. Single photon emission computed tomography (SPECT) can be used to perform such dosimetry calculations. However, the accuracy of dosimetry estimates strongly depends on the accuracy of activity quantification in 188Re images. In this study, we performed a series of phantom experiments aiming to investigate the accuracy of activity quantification for 188Re SPECT using high-energy and medium-energy collimators. Objects of different shapes and sizes were scanned in Air, non-radioactive water (Cold-water) and water with activity (Hot-water). The ordered subset expectation maximization algorithm with clinically available corrections (CT-based attenuation, triple-energy window (TEW) scatter and resolution recovery was used). For high activities, the dead-time corrections were applied. The accuracy of activity quantification was evaluated using the ratio of the reconstructed activity in each object to this object’s true activity. Each object’s activity was determined with three segmentation methods: a 1% fixed threshold (for cold background), a 40% fixed threshold and a CT-based segmentation. Additionally, the activity recovered in the entire phantom, as well as the average activity concentration of the phantom background were compared to their true values. Finally, Monte-Carlo simulations of a commercial γ -camera were performed to investigate the accuracy of the TEW method. Good quantification accuracy (errors  activity concentration and for objects in cold background segmented with a 1% threshold. However, the accuracy of activity quantification for objects segmented with 40% threshold or CT-based methods decreased (errors  >15%), mostly due to partial-volume effects. The Monte-Carlo simulations confirmed that TEW-scatter correction applied to 188Re, although practical, yields only approximate estimates of the true scatter.

  13. Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

    Steinborn, Christian Martin


    As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

  14. Comparision of {sup 188}Rhenuim-tin colloid and {sup 188}Rhenium-sulfur colloid as a radiation synovectomy agent

    Lee, Y. J.; Jung, J. M.; Kim, Y. J.; Jang, Y. S.; Lee, D. S.; Jung, J. K.; Song, Y. W.; Lee, M. C. [KAERI, Taejon (Korea, Republic of)


    Beta-emitting radiocolloids have been used for the treatment of rheumatoid arthritis. As a generator produced beta-emitting radionuclide, the importance of Re-188 for radionuclide therapy is increasing rapidly. We compared the radiochemistry of two {sup 188}Re labeled radiocolloids: {sup 188}Re-tin colloid and {sup 188}Re-sulfur colloid. {sup 188}Re-tin colloid was obtained by reacting 10 mg SnCl{sub 2}{center_dot}H{sub 2}O and {sup 188}Re perrhenate. {sup 188}Re-sulfur colloid was labeled by boiling 40 mg sodium thiosulfate, 0.8 mg Na{sub 2}{center_dot}EDTA, and 0.8 mg potassium perrhenate with {sup 188}Re perrhenate. Radiochemical purity was checked by ITLC-SG/ saline. Labeling efficiencies reached >98% for tin colloid at 2 hr and 89{approx}94% for sulfur colloid at 3 hr. All the preparations were stable for 72 hr in water, serum, and synovial fluid. If labeled at higher temperature, particle size of tin colloid increased. Remained radioactivity of {sup 188}Re-sulfur colloid in disposable polypropylene syringe after injecting to mice was high (62.0{+-}7.0%) due to its hydrophobic nature, although, tin colloid did not show high remained radioactivity (2.9{+-}1.6%). Biodistribution in Antigen induced arthratitis model rabbit after synovial space injection showed that {sup 188}Re-tin colloid was well retained in synovial space for 48 hr. Although, both {sup 188}Re-tin colloid and {sup 188}Re-sulfur colloid might be useful for radionuclide therapy, we concluded that {sup 188}Re-tin colloid is more adventageous over {sup 188}Re-sulfur colloid, due to higher labeling efficency, size-controllable property, and lower residual activity in syringe.

  15. Rhenium- and molybdenum-catalyzed dehydration reactions. A fundamental step in the conversion of bio-based alcohols to olefins

    Korstanje, T.J.|info:eu-repo/dai/nl/314841008


    As the supply of fossil feedstocks is diminishing, and the consequences thereof are increasing, also the urgency for research into alternative feedstocks is increasing. To provide building blocks for the chemical industry in sufficient amounts and in a sustainable manner, only one alternative resour

  16. Structure and composition of higher-rhenium-content superalloy based on La-alloyed Ni-Al-Cr

    Kozlov, Eduard V.; Koneva, Nina A. [Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation); Nikonenko, Elena L., E-mail: [Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Popova, Natalya A.; Fedorischeva, Marina V. [Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation); Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)


    The paper presents the transmission and scanning electronic microscope investigations of Ni-Al-Cr superalloy alloyed with additional Re and La elements. This superalloy is obtained by a directional solidification method. It is shown that such additional elements as Re and La result in formation of new phases in Ni-Al-Cr accompanied by considerable modifications of quasi-cuboid structure in its γ’-phase.

  17. Structure and reactivities of rhenium and technetium bis-arene sandwich complexes [M(η(6)-arene)2]().

    Meola, Giuseppe; Braband, Henrik; Jordi, Sara; Fox, Thomas; Blacque, Olivier; Spingler, Bernhard; Alberto, Roger


    Sandwich complexes are important building blocks in medicinal inorganic chemistry for group 6 and 8 elements but are almost unknown for the manganese triad. We present the syntheses and full characterization of the mixed-arene (99)Tc sandwich complexes [(99)Tc(η(6)-hmbz)(η(6)-C6H5-NH3)](PF6)2 and [(99)Tc(η(6)-hmbz)(η(6)-C6H5-Br)](PF6). Both comprise functionalities for conjugation to targeting molecules or for being included as substructures in pharmaceutically active lead compounds. Since η(6)-benzene ligands are too stably bound to be replaced with incoming ligands, we prepared naphthalene complexes [Re(η(6)-C6H6)(η(6)-napht)](+) and [Re(η(6)-napht)2](+). Their reactivities towards substitution are increased and one or both naphthalene ligands can be replaced with mono- or multi-dentate ligands. Combining the features of (99)Tc and Re may lead to a molecule-based theranostic approach.

  18. Patient effective doses during intracoronary irradiation with a Rhenium 188 full filled balloon catheter after percutaneous transluminal coronary artery

    Ponce V, L.; Peix G, A.; Llerena R, L.; Santana V, L. [Instituto de Cardiologia, La Habana (Cuba); Lopez D, A. [Hospital Hermanos Amejeiras, La Habana (Cuba)


    Intracoronary irradiation with a full filled Re188 balloon catheter treatment technique (IRT) after Percutaneous Transluminal Coronary Artery (PTCA) should represent an addition patient exposure dose with respect to common PTCA procedure. Our proposes were determinate the absorbed doses and estimate the risk for fatal cancer in 25 patients (15 males, mean age: 559 years old) treated during an IRT randomized clinical trial carried out in our institution as part of IAEA technical cooperation project. 20 Gy was always the prescribed doses for each patient. The average Re188 concentrated activity used and treatment time were 5256{+-}2371 MBq/ml in 1.5-2 ml and 466{+-}195 seconds, respectively. Two thermoluminescent dosimeters were attached in the chest and pelvis for each patient treated. Calibration for attenuation and scattered radiations was done. The maximal and mean value effective dose obtained for chest patient region were 18 mSv and 15{+-}6 mSv, respectively and for pelvis patient region the results were 10 mSv and 8{+-}3 mSv, respectively. The total risk to develop fatal cancer was 0.084% for patient treated. The patient effective doses is slightly superior to those reported for common procedures as PTCA. The IRT is considered a quite safe procedure, but in order to exposure radiation level optimization the continuous review of procedure should be constantly done. (Author)

  19. Direct intratumoral infusion of liposome encapsulated rhenium radionuclides for cancer therapy: Effects of nonuniform intratumoral dose distribution

    Hrycushko, Brian A.; Li Shihong; Goins, Beth; Otto, Randal A.; Bao, Ande [Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States); Department of Otolaryngology-Head and Neck Surgery, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States); Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 and Department of Otolaryngology-Head and Neck Surgery, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States)


    Purpose: Focused radiation therapy by direct intratumoral infusion of lipid nanoparticle (liposome)-carried beta-emitting radionuclides has shown promising results in animal model studies; however, little is known about the impact the intratumoral liposomal radionuclide distribution may have on tumor control. The primary objective of this work was to investigate the effects the intratumoral absorbed dose distributions from this cancer therapy modality have on tumor control and treatment planning by combining dosimetric and radiobiological modeling with in vivo imaging data. Methods: {sup 99m}Tc-encapsulated liposomes were intratumorally infused with a single injection location to human head and neck squamous cell carcinoma xenografts in nude rats. High resolution in vivo planar imaging was performed at various time points for quantifying intratumoral retention following infusion. The intratumoral liposomal radioactivity distribution was obtained from 1 mm resolution pinhole collimator SPECT imaging coregistered with CT imaging of excised tumors at 20 h postinfusion. Coregistered images were used for intratumoral dosimetric and radiobiological modeling at a voxel level following extrapolation to the therapeutic analogs, {sup 186}Re/{sup 188}Re liposomes. Effective uniform dose (EUD) and tumor control probability (TCP) were used to assess therapy effectiveness and possible methods of improving upon tumor control with this radiation therapy modality. Results: Dosimetric analysis showed that average tumor absorbed doses of 8.6 Gy/MBq (318.2 Gy/mCi) and 5.7 Gy/MBq (209.1 Gy/mCi) could be delivered with this protocol of radiation delivery for {sup 186}Re/{sup 188}Re liposomes, respectively, and 37-92 MBq (1-2.5 mCi)/g tumor administered activity; however, large intratumoral absorbed dose heterogeneity, as seen in dose-volume histograms, resulted in insignificant values of EUD and TCP for achieving tumor control. It is indicated that the use of liposomes encapsulating radionuclides with higher energy beta emissions, dose escalation through increased specific activity, and increasing the number of direct tumor infusion sites improve tumor control. For larger tumors, the use of multiple infusion locations was modeled to be much more efficient, in terms of activity usage, at improving EUD and TCP to achieve a tumoricidal effect. Conclusions: Direct intratumoral infusion of beta-emitting radionuclide encapsulated liposomes shows promise for cancer therapy by achieving large focally delivered tumor doses. However, the results of this work also indicate that average tumor dose may underestimate tumoricidal effect due to substantial heterogeneity in intratumoral liposomal radionuclide distributions. The resulting intratumoral distribution of liposomes following infusion should be taken into account in treatment planning and evaluation in a clinical setting for an optimal cancer therapy.

  20. fac-Acetonitriletricarbonyl(dimethylcarbamodithioato-κ2S,S′rhenium(I: crystal structure and Hirshfeld surface analysis

    Sang Loon Tan


    Full Text Available The title compound, [Re(C3H6NS2(C2H3N(CO3], features an octahedrally coordinated ReI atom within a C3NS2 donor set defined by three carbonyl ligands in a facial arrangement, an acetonitrile N atom and two S atoms derived from a symmetrically coordinating dithiocarbamate ligand. In the crystal, dithiocarbamate-methyl-H...O(carbonyl interactions lead to supramolecular chains along [36-1]; both dithiocarbamate S atoms participate in intramolecular methyl-H...S interactions. Further but weaker acetonitrile-C—H...O(carbonyl interactions assemble molecules in the ab plane. The nature of the supramolecular assembly was also probed by a Hirshfeld surface analysis. Despite their weak nature, the C—H...O contacts are predominant on the Hirshfeld surface and, indeed, on those of related [Re(CO3(C3H6NS2L] structures.

  1. Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst

    Qingde Zhang


    Full Text Available Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs were selected as support to prepare a Re-based catalyst for dimethyl ether (DME direct oxidation to polyoxymethylene dimethyl ethers (DMMx. The catalyst performance was tested in a continuous flow type fixed-bed reactor. H3PW12O40 (PW12 was used to modify Re/CNTs to improve its activity and selectivity. The effects of PW12 content, reaction temperature, gas hourly space velocity (GHSV and reaction time on DME oxidation to DMMx were investigated. The results showed that modification of CNT-supported Re with 30% PW12 significantly increased the selectivity of DMM and DMM2 up to 59.0% from 6.6% with a DME conversion of 8.9%; besides that, there was no COx production observed in the reaction under the optimum conditions of 513 K and 1800 h−1. The techniques of XRD, BET, NH3-TPD, H2-TPR, XPS, TEM and SEM were used to characterize the structure, surface properties and morphology of the catalysts. The optimum amount of weak acid sites and redox sites promotes the synthesis of DMM and DMM2 from DME direct oxidation.

  2. Preparation and Mechanical and Tribological Properties of W-C-S-Mo Composite Films%W-C-S-Mo复合薄膜的制备及力学和摩擦学性能∗

    杨旭红; 周晖; 杨拉毛草; 郑军; 万志华; 张延帅


    The composite films including four⁃component W⁃C⁃S⁃Mo different bias substrate voltage were deposited on Si substrate by a hybrid of magnetron sputtering and DC filtered cathodic vacuum arc (MS/FCVA) technology.Impacts of bi⁃as substrate voltage on mechanical properties as hardness,elastic modulus and adhesion force of these different nano⁃films were analyzed by nano⁃hardness tester and nano⁃scratch tester,and impacts of bias substrate voltage on tribological proper⁃ties in different environments ranging from humid air to vacuum of space were studied by CSM ball⁃on⁃disk tester.The re⁃sults show that hardness,elastic modulus and adhesion force of the film is tend to increase first and then decrease along with increasing of the bias substrate voltage,and the films under substrate bias voltage of -100 V have the best mechanical properties.The W⁃C⁃S⁃Mo films prepared under-100 V bias voltage have excellent tribological properties in both humid air and vacuum environment.Raman test results show that the lubrication of W⁃C⁃S⁃Mo films is significantly supported by DLC in humid air environment,furthermore,the MoS2 crystal particles in soft phases of the film have lubrication function in vac⁃uum environment.%利用磁控溅射与磁过滤阴极真空电弧( MS/FCVA)复合沉积法,在不同偏压下在单晶Si基体上制备W⁃C⁃S⁃Mo四元复合薄膜;分析沉积偏压对薄膜纳米硬度、弹性模量和膜基结合力等力学性能的影响;在潮湿大气、真空环境下研究偏压对薄膜摩擦学性能的影响。结果表明,薄膜硬度、弹性模量和附着力随着沉积负偏压的增大呈现先增大后减小的趋势,在偏压-100 V时薄膜力学性能最好;负偏压-100 V下制备的W⁃C⁃S⁃Mo四元复合薄膜样品在潮湿大气和真空环境下均具有较好的摩擦学性能,拉曼测试发现, W⁃C⁃S⁃Mo复合薄膜在潮湿大气环境中的润滑作用主要由DLC提供,而在真空环境中薄膜中的软质相MoS2晶粒起润滑作用。

  3. Radionuclides retention in C-S-H, main phases of cement matrices for low and intermediate-level wastes; Retencion de radionuclidos en C-S-H, principales fases de matrices de cemento para desechos de bajo y medio nivel

    Badillo A, V. E.; Lopez R, C.; Vidal M, J. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Gutierrez B, O., E-mail: [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Exrancho La Virgen, Metepec, Estado de Mexico (Mexico)


    Knowing that the behavior of cementitious materials based on hydraulic binder called cement is essentially determined by the physicochemical evolution of the cement paste (water + cement) which constitutes it, the evolution of the cement paste in contact with different aqueous solutions is studied since one of the main risks in safety of systems is composed of surface and groundwater, which contribute to the alteration of the different barriers and represent the main way of radionuclides transport. The calcium silicates CSH are the main phases that compose the systems based on Portland cement. The hydrates calcium silicates possess a high degree of structural complexity which includes crystalline, partially crystalline and amorphous phases. In this study the microstructures of the CSH phases as well as the retention of radionuclide Sr (II) are studied through the {sup 87m}Sr in formulations of water/cement w/c = 0.55; experimental values of K d low around 20 ml g{sup -1} are obtained in function of hydration time of the cement paste in equilibrium with aqueous solutions. (Author)

  4. Variación diaria de la abundancia del zooplancton en Bahía Magdalena, B.C.S. México Daily cycle of zooplankton abundance in Magdalena Bay, B.C.S. Mexico

    Sergio Hernández-Trujillo


    Full Text Available Se presenta la variación diaria de la abundancia de zooplancton en Bahía Magdalena, México a partir de muestreos en una estación fija durante 10 días en febrero de 2002. De 112 taxa identificados, los nauplios de balanos y los cladóceros Penilia avirostris y Pseudevadne tergestina fueron los más comunes y abundantes y con niveles de variación diaria de más del 100%. Los copépodos constituyeron una quinta parte de la abundancia del zooplancton y 7 de las 80 especies encontradas se registran por vez primera en la zona de estudio. La abundancia del zooplancton fue parcialmente coherente con la hidrografía de la bahía, así como con un modelo de retención de partículas. Las 3 especies de copépodos más abundantes fueron más numerosas a inicio de la serie pero tendieron a reducir su densidad hacia el fin del lapso de estudio. La hidrodinámica invernal en la zona se identificó como un factor de concentración de zooplancton, quizá de importancia mayor que la temperatura o la concentración de clorofila a, aún no estimada en la estructura de la comunidad ni en la intensidad de las relaciones interespecíficas.This paper presents the daily variation of the abundance of zooplankton in Magdalena Bay, Mexico from sampling in a fixed-station for 10 days of February 2002. From 112 taxa identified barnacles nauplii and cladocerans Penilia avirostris and Pseudevadne tergestina were the most common and abundant with daily variation levels more than 100%. The copepods constituted one fifth of zooplankton abundance and 7 of the 80 species found were recorded for the first time in the study area. Zooplankton abundance showed partially coherent pattern with the hidrography of the bay as well as particles retention model. The 3 species of copepods more abundant were more numerous at the beginning of the time series but tended to reduce its density toward the end of the time of study. Winter hydrodynamics was identified as a factor of zooplankton concentration, perhaps more important than the temperature or the concentration of chlorophyll a, with a weight still not estimated in the structure of the community or the intensity of the interspecific relationships.

  5. Integrative molecular and microanalytical studies of syntrophic partnerships linking C, S, and N cycles in anoxic environments

    Orphan, Victoria [California Inst. of Technology (CalTech), Pasadena, CA (United States)


    Syntrophy and other forms of symbiotic associations between microorganisms are central to carbon and nutrient cycling in the environment. However, the inherent interdependence of these interactions, dynamic behavior, and frequent existence at thermodynamic limits has hindered our ability to both recognize syntrophic partnerships in nature and effectively study their behavior in the laboratory. To characterize and understand the underlying factors influencing syntrophic associations within complex communities requires a suite of tools that extend beyond basic molecular identification and cultivation. This specifically includes methods that preserve the natural spatial relationships between metabolically interdependent microorganisms while allowing downstream geochemical and/or molecular analysis. With support from this award, we have developed and applied new combinations of molecular, microscopy, and stable isotope-based methodologies that enable the characterization of fundamental links between phylogenetically-identified microorganisms and their specific metabolic activities and interactions in the environment. Through the coupling of fluorescence in situ hybridization (FISH) with cell capture and targeted metagenomics (Magneto-FISH), and FISH + secondary ion mass spectrometry (i.e. FISH-SIMS or FISH-nanoSIMS), we have defined new microbial interactions and the ecophysiology of anaerobic microorganisms involved in environmental methane cycling.

  6. Determination of the bond dissociation energies of FeX and NiX (X = C, S, Se)

    Matthew, Daniel J.; Tieu, Erick; Morse, Michael D.


    The bond dissociation energies of FeC, NiC, FeS, NiS, FeSe, and NiSe have been measured by the observation of a predissociation threshold in their resonant two-photon ionization spectra. Because the lowest separated atom limits generate a vast number of potential energy curves, it is thought that the molecules dissociate as soon as the ground separated atom limit is exceeded in energy. From the observed thresholds, dissociation energies have been measured as D0(FeC) = 3.961(19), D0(NiC) = 4.167(3), D0(FeS) = 3.240(3), D0(NiS) = 3.651(3), D0(FeSe) = 2.739(6), and D0(NiSe) = 3.218(3) eV. Through the use of thermochemical cycles, these values have been combined with other precisely known values to improve the accuracy of other quantities, providing: D0(Fe+-C) = 4.270(19) eV, D0(Ni+-C) = 3.435(3) eV, IE(FeS) = 8.06(4) eV, IE(NiS) = 8.82(4) eV, and D0 (Fe-S-) = 2.92(10) or 2.89(10) eV, depending on the reference employed for EA(FeS-). Comparisons to previous values are noted, when available. The periodic trends observed are discussed in terms of a molecular orbital diagram for these species. Finally, these results have also been used to calculate 0 K enthalpies of formation of the gaseous MX molecules.

  7. cs of abrasive-reactive nanocomposite powder synthesis in the SiO2 − C/S system

    Faryt Urakaev


    Full Text Available In this study, the syntheses of cementite (Fe3C and pyrite (FeS2 have been performed by mechanical activation of a mixture of graphite or sulfur with amorphous or crystalline silica in a planetary ball mill AGO-2 with steel fittings. XRD analysis was used to record products and changes of systems components after mechanical activation of the studied systems. The formation of nanocomposites based on cementite (or pyrite has been recorded and the quantitative characteristics of abrasive-reactive wear of steel milling tools have been evaluated. It has been demonstrated the possibility of steel material reaction of milling tools for direct mechanochemical preparation of composite based on cementite using abrasive properties of silica modifications. It has obtained nanocomposites based on pyrite and glass matrix during mechanical activation of quartz glass and sulfur in a time of 1-2 orders of magnitude lower than traditional mechanical alloying powders of iron and sulfur. It can be noted that any scrap metal and ceramic products can be used as milling tools. This significantly enhances the ability of the proposed method of abrasive-reactive nanowear of milling tools materials of mechanochemical reactors and processed materials.

  8. Antonio Quilis, La concodancia gramatiaal en Za Zengua espanola hablada en Madrid, C. S. I. C., Madrid 1983, pags. 128

    Mitja Skubic


    Full Text Available El libra de Antonio Quilis, de poco más de cien páginas, nos ofrece los resultados de las encuestas sabre la concordancia sintáctica en el habla de Madrid. El Autor que es también cultivador y conocedor de la fonética del español­ pensemos en su importante trabajo sobre la fonética acústica de la lengua española (Gredos, Madrid 1981 - vuelve aqué a su vocacion de sintáctico, visible en sus trabajos sabre la estructura del español la edición de la Gramática de Nebri­ja y en el amor con que cuidó la presentación al mundo de habla castellana de las obras de B. Pottier.

  9. A compact and low cost TT&C S-Band Ground Station for low orbit satellites

    Pacola, Luiz C.; Ferrari, Carlos A.

    Instituto Nacional de Pesquisas Espaciais (INPE's) S-Band Ground Station for satellite control and monitoring is revised consdiering the current software and hardware technology. A Ground Station concept for low orbit satellites is presented. The front-end uses a small antenna and low cost associated equipment without loss of performance. The baseband equipment is highly standardized and developed on a personal computer IBM compatible using extensively Digital Signal Processing (DSP). A link budget for ranging, telecommand and telemetry is also presented.

  10. Reid's Read-Alouds 2: Modern-Day Classics from C.S. Lewis to Lemony Snicket

    Reid, Rob


    Need a one-stop resource for jumpstarting sleepy library visitors? Ready to add punch to classroom discussions? In this companion to his best-selling book "Reid's Read-Alouds", children's lit guru Reid dips back into the classics to highlight outstanding titles published between 1950 and 1999 that continue to connect with kids and teens today.…

  11. El trabajo colaborativo en redes. Análisis de una experiencia en la R.A.C.S.

    Román Graván, Pedro


    Los españoles se incorporan a Internet a un ritmo constante. Ya en los meses de abril y mayo del año 2000, 3.900.000 personas utilizaron la red habitualmente, aunque el universo de personas con acceso a la misma, alcanza 4.600.000 personas (13,4% de la población mayor de 14 años). Los internautas son ahora un millón más que a finales de 1999, según los datos del Estudio General de Medios. La mayoría entra ahora en la red desde el hogar...

  12. Habit as a Connection Between Nature, Mind and Culture in C.S. Peirce’s Semiotic Pragmaticism

    Brier, Søren

    theories and models. The end of research in a certified truth is an ideal far away in the future. Furthermore he was not a physicalistic material mechanists but a process philosopher and an evolutionary synechist. This means that he thought that mind and matter was connected in a continuum and that matter......’s theory of motion was reversible. Time had no arrow. But in Peirce’s cosmogony change is at the basis as Firstness is imbued with the tendency to take habits and time therefore has an arrow and is irreversible and therefore what the laws manifested as the universe develop. This was unthinkable from...

  13. Coupled C-S-Fe geochemistry in a rapidly accumulating marine sedimentary system: Diagenetic and depositional implications

    Peketi, A.; Mazumdar, A.; Joao, H; Patil, D.J.; Usapkar, A.; Dewangan, P.

    on sulfidization Coupled occurrence of 34S-enriched iron sulfide (pyrite) with 12C-enriched authigenic carbonate zones is the possible records of paleo-sulfate methane transition zones where AOM-driven-focused sulfate reduction was likely...


    José Renato Salatiel


    Full Text Available Em Empirismo e Filosofia da Mente, de 1956, Wilfrid Sellars criticou a teoria do “mitodo dado”, quer dizer, a ideia de que o conhecimento empírico repousa sobre a fundação de saberesnão-inferenciais. Ao lado de trabalhos de W.V.O. Quine e do “segundo” Wittgenstein, o texto deSellars foi responsável por colocar a filosofia analítica num estágio adiante de suas origens nopositivismo lógico, e também por cultivar o diálogo com o pragmatismo, sobretudo com osfilósofos neopragmatistas. Contudo, quase noventa anos antes do clássico de Sellars, CharlesSanders Peirce, considerado o fundador do pragmatismo, elaborou uma epistemologia póscartesianana qual negava, de modo semelhante, que o conhecimento intuitivo pode servir de basepara crenças. O presente artigo objetiva investigar a proximidade destas teorias, contribuindo paraestreitar as relações entre filosofia analítica e pragmatismo. Conclui-se que Peirce, diferente deSellars, mantém uma forma “saudável” de empirismo “fraco”, que serve de atrito para a elaboraçãoconceitual, ainda que sobre experiências futuras.

  15. Challenging the Objectivist Paradigm: Teaching Biblical Theology with J. R. R. Tolkien, C. S. Lewis, and Guillermo del Toro

    Lief, Jason


    The dissimilarity that exists between the historical and cultural situation of North American college students and the world described by the biblical authors poses a problem for theological and religious education. While the biblical authors tell fantastic stories of miracle and magic, the scientific and technological paradigm prevalent in…

  16. Cambio estacional de clorofila en la Bahía de la Paz, B. C. S., México

    Martinez Lopez, Aida; Cervantes Duarte, Rafael; Reyes Salina, A.; Valdez Hoguin, J.E.


    En el período abril de 1993 a marzo de 1995 se analizaron datos diarios de intensidad y dirección del viento, datos mensuales de temperatura hasta 25 metros, profundidad del disco de Secchi y la concentración de clorofila a, en superficie, 10 y 25 metros, en 5 estaciones ubicadas en la Bahía de La Paz. Los vientos presentaron una componente norte durante los meses de octubre a marzo y vientos dominantes del sur de abril a septiembre. Las temperaturas más altas ocurrieron durante julio-octubre...

  17. Copper-mediated C-H activation/C-S cross-coupling of heterocycles with thiols

    Ranjit, Sadananda


    We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2′-bipyridine and Na 2CO 3. We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimental results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bidentate ligand such as 2,2′-bipyridine; R: aryl or alkyl group) is the first reactive intermediate responsible for the observed organic transformation. Furthermore, our computational studies suggest a stepwise reaction mechanism based on a hydrogen atom abstraction pathway, which is more energetically feasible than many other possible pathways including β-hydride elimination, single electron transfer, hydrogen atom transfer, oxidative addition/reductive elimination, and σ-bond metathesis. © 2011 American Chemical Society.

  18. en el mar y en el desierto: Reserva de la Biosfera El Vizcaíno, B.C.S.

    Denise Soares


    Full Text Available This article analyzes El Vizcaíno Bioreserve in terms of gender relations and their interconnections with its environmental reality. An attempt is made to contribute elements that could serve as inputs for implementing programs and actions might allow the region to become an area where development would not be at variance with resource conservation and where women would constitute the crux of an equitable and sustainable economic growth process. The article begins by explaining the conceptual and the methodological framework on which the analysis is based. Then, El Vizcaíno bioreserve, as a protected natural environment, is briefly introduced. Gender relations in the bioreserve´s various microregions are analyzed as are their interconnections with the microregion´s environmental dynamics. Finally, the study´s conclusions are offered

  19. A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway.

    Liu, Jinyong; Han, Mengwei; Wu, Dimao; Chen, Xi; Choe, Jong Kwon; Werth, Charles J; Strathmann, Timothy J


    Rapid reduction of aqueous ClO4(-) to Cl(-) by H2 has been realized by a heterogeneous Re(hoz)2-Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx(-) intermediates formed during reactions with concentrated ClO4(-) promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4(-) reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2(-) intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4(-) reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx(-) scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significantly mitigate Re complex decomposition by slightly lowering the OAT activity when immobilized in Pd/C. Further stability enhancement is then obtained by switching the nanoparticles from Pd to Rh, which exhibits high reactivity with ClOx(-) intermediates and thus prevents their deactivating reaction with the Re complex. Compared to Re(hoz)2-Pd/C, the new Re(hoz)(htz)-Rh/C catalyst exhibits similar ClO4(-) reduction activity but superior stability, evidenced by a decrease of Re leaching from 37% to 0.25% and stability of surface Re speciation following the treatment of a concentrated "challenge" solution containing 1000 ppm of ClO4(-). This work demonstrates the pivotal roles of coordination chemistry control and tuning of individual catalyst components for achieving both high activity and stability in environmental catalyst applications.

  20. In vitro and in vivo evaluation of direct rhenium-188-labeled anti-CD52 monoclonal antibody alemtuzumab for radio immunotherapy of B-cell chronic lymphocytic leukemia

    De Decker, Mario; Bacher, Klaus; Thierens, Hubert; Slegers, Guido; Dierckx, Rudi A.; De Vos, Filip


    Alemtuzumab (Campath, Berlex) is a humanized IgG1 rat monoclonal antibody directed against the cell surface CD52 antigen, found on lymphocytes and monocytes. It is being developed for the treatment of chronic lymphocytic leukemia (CLL), autoinumme disease and for the prevention of transplant rejecti

  1. In vitro and in vivo evaluation of direct rhenium-188-labeled anti-CD52 monoclonal antibody alemtuzumab for radioimmunotherapy of B-cell chronic lymphocytic leukemia

    Decker, Mario de [Department of Radiopharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent (Belgium); Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, Groningen (Netherlands)], E-mail:; Bacher, Klaus; Thierens, Hubert [Department of Medical Physics and Radiation Protection, Ghent University, Ghent (Belgium); Slegers, Guido [Department of Medical Imaging of Domestic Animals, Ghent University, Ghent (Belgium); Dierckx, Rudi A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, Groningen (Netherlands); Vos, Filip de [Department of Radiopharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent (Belgium)


    Alemtuzumab (Campath, Berlex) is a humanized IgG1 rat monoclonal antibody directed against the cell surface CD52 antigen, found on lymphocytes and monocytes. It is being developed for the treatment of chronic lymphocytic leukemia (CLL), autoimmune disease and for the prevention of transplant rejection. This study focused on synthesis, quality control, in vitro evaluation and biodistrubution of {sup 188}Re-labeled alemtuzumab for radioimmunotherapy of B-cell CLL. {sup 188}Re-alemtuzumab was synthesized using a direct radiolabeling method. Reduction of the intramolecular disulfide bonds of the antibody was performed with tris-(carboxyethyl)-phosphine (Pierce), using a 1:60 molar excess. Reaction took place at room temperature for 20 min. A PD-10 desalting column was used to purify the reduced antibody from excess phospine. Complexation and transchelation of {sup 188}ReO{sub 4}{sup -} was achieved using sodium gluconate as weak chelator and SnCl{sub 2} as reducing agent. Quality control was done using instant thin-layer chromatography. Binding assays were performed on a CD52-positive cell line (HuT-78). Female NMRI mice were injected intravenously with 20 {mu}g radiolabeled alemtuzumab and killed at preset time intervals for biodistribution studies. Tissues were dissected, weighed and counted for determination of radioactivity. Data were expressed as percentage injected activity per gram of tissue (% IA/g tissue) or as percentage injected activity (% IA). {sup 188}Re-alemtuzumab was prepared achieving high radiochemical yields. Labeling efficiency of more than 95% can be obtained using optimal reaction conditions. {sup 188}Re-alemtuzumab showed good in vitro stability, remaining intact at 24 h after radiolabeling. In mice, {sup 188}Re-alemtuzumab showed high uptake in the blood (25.10{+-}1.36% IA at 1 h p.i.), followed by a biexponential clearance (t{sub 1/2{alpha}}=4.790 h and t{sub 1/2{beta}}=55.45 h). Increased uptake was observed in kidneys and heart (9.29{+-}0.46% IA/g in kidneys and 6.10{+-}1.82% IA/g in heart at 1 p.i.). The highest absorbed radiation dose was received by the kidneys (0.159-3.26 mGy/MBq) and heart wall (0.0705-0.132 mGy/MBq). The predicted radiation dose for the total body was in the range of 0.0459-0.0529 mGy/MBq. The effective dose for the human reference adult was estimated to be approximately 0.0486-0.195 mSv/MBq. {sup 188}Re-alemtuzumab can be prepared with high radiochemical yield and purity and showed good in vitro behavior and favorable biodistribution. Therefore, {sup 188}Re-alemtuzumab would be an ideal candidate for radioimmunotherapy of chronic lymphocytic leukemia.

  2. Interdiffusion behavior of tungsten or rhenium and group 5 and 6 elements and alloys of the periodic table, part 1. [at dissimilar metal joints

    Arcella, F. G.


    Arc cast W, CVD W, CVD Re, and powder metallurgy Re materials were hot isostatically pressure welded to ten different refractory metals and alloys (Cb, Cb-1Zr, Ta, Ta-10W, T-111, ASTAR-811C, W-25Re, Mo-50Re, W-30Re-20Mo, ect.) and thermally aged at 10 to the minus 8th power torr at 1200, 1500, 1630, 1800, and 2000 C for 100 to 2000 hours. Electron beam microprobe analysis was used to characterize the interdiffusion zone width of each couple system as a function of age time and temperature. Extrapolations of interdiffusion zone thickness to 10,000 hours were made. Classic interdiffusion analysis was performed for several of the systems by Boltzmann-Matano analysis. A method of inhibiting Kirkendall voids from forming during thermal ageing of dissimilar metal junctions was devised and experimentally demonstrated. An electron beam weld study of Cb-1Zr to Re and W-25Re demonstrated the limited acceptability of these welds.

  3. Interdiffusion behavior of tungsten or rhenium and group 5 and 6 elements and alloys of the periodic table. Part 2A: Appendices A-G

    Arcella, F. G.


    Arc cast W, CVD, W, CVD Re, and powder metallurgy Re materials were hot isostatically pressure welded to ten different refractory metals and alloys and thermally aged at 10 to the minus 8th power torr at 1200 C, 1500 C, 1630 C, 1800 C, and 2000 C for 100 hours to 2000 hours. Electron beam microprobe analysis was used to characterize the interdiffusion zone width of each couple system as a function of age time and temperature. Each system was least squares fitted to the equation: In (delta X sq/t) = B/T + A, where delta X is net interdiffusion zone width, t is age time, and T is age temperature. Detailed descriptions of experimental and analytical procedures utilized in conducting the experimental program are provided. For Vol. 1, see N74-34046.


    马高峰; 雷宁; 郭金亮; 王子川; 谢亚宁; 孙宝莲; 白宏斌; 冯宝奇



  5. A Model gamma-Alumina-Supported Rhenium-Platinum Catalyst Prepared from [Re2Pt(CO)12]: 1. Synthesis and Spectroscopic Characterization.

    Koningsberger, D.C.; Fung, A.S.; McDeVitt, M.R.; Tooley, P.A.; Kelley, M.J.; Gates, B.C.


    Catalysts supported on -Al2O3 were prepared from [Re2Pt(CO)12], and from Pt (NH3)4(NO3)2 and NH4ReO4. The former samples were characterized by infrared and X-ray photoelectron spectroscopies (XPS) and by temperature-programmed reduction (TPR); the latter were characterized by TPR. [Re2Pt(CO)12] was

  6. Rhenium-osmium isotope constraints on the age and source of the platinum mineralization in the Lower Cambrian black rock series of Hunan-Guizhou provinces, China

    李胜荣; 肖启云; 申俊峰; 孙丽; 刘波; 阎柏琨; 江永宏


    The shale at the bottom of the Lower Cambrian black series in South China is rich in nonferrous metals, noble metals, rare and dispersed elements and radioactive elements, known as "polyelement-rich bed". In order to date and trace the source of the platinum group elements, 6 samples were collected from the Zhongnan region of Guizhou Province, and the Ganzi- ping-Sancha region of Hunan Province. The contents and isotopes of Re and Os were measured. Re and Os are positively correlated with each other and the correlation coefficient between 187Os/188Os and 187Re/188Os is 0.99856. On the 187Os/188Os-187Re/188Os diagram, 6 sample points are well-distributed along the (542±11) Ma fitting isochron in high coincidence and with 0.84±0.12 as the initial 187Os/188Os value. The result displays that the age value of the major mineralization of Re, Os and other platinum group elements is (542±11) Ma, which is identical with the stratigraphical age of the wall rocks; the 'polyelement beds' in Hunan and Guizhou provinces bear high isochroneity; the differences of the forming times of different materials in the 'polyelement bed' of the same area do not surpass the error limit permissible for Re-Os date fitting; there exists no distinct time interval between the formation of the diagenetic veinlets and that of the 'polyelement bed', or the Re-Os isotope composition has not been distinctly changed by the former process; basaltic crust might be the major source of Re, Os, other platinum group and trace elements in the Lower Cambrian 'polyelement bed' of Hunan and Guizhou provinces.

  7. fac-[1,2-Bis(pyridin-4-ylethane-κN]tricarbonyl(1,10-phenanthroline-κ2N,N′rhenium(I hexafluoridophosphate acetonitrile monosolvate

    Silvana Guilardi


    Full Text Available The asymmetric unit of the title compound, [Re(C12H8N2(C12H12N2(CO3]PF6.·CH3CN, contains one cation, one hexafluoridophosphate anion and one acetonitrile solvent molecule. The ReI ion is coordinated by two N atoms from the 1,10-phenanthroline ligand and one N atom from the 1,2-bis(pyridin-4-ylethane ligand [mean Re—N = 2.191 (15 Å] and by three carbonyl ligands [mean Re—C = 1.926 (3 Å] in a distorted octahedral geometry. The electrostatic forces and weak C—H...F(O hydrogen bonds pack cations and anions into the crystal with voids of 82 Å3, which are filled by solvent molecules. The crystal packing exhibits short intermolecular O...O distance of 2.795 (5 Å between two cations related by inversion.

  8. Intracoronary {beta}-brachytherapy using a rhenium-188 filled balloon catheter in restenotic lesions of native coronary arteries and venous bypass grafts

    Woehrle, Jochen; Nusser, Thorsten; Habig, Thomas; Kochs, Matthias; Hombach, Vinzenz [University of Ulm, Department of Internal Medicine II (Germany); Krause, Bernd J.; Mottaghy, Felix M.; Reske, Sven N. [University of Ulm, Department of Nuclear Medicine (Germany); Kotzerke, Joerg [University of Dresden, Department of Nuclear Medicine (Germany); Hoeher, Martin [Klinikum Bayreuth, Department of Internal Medicine II (Germany)


    We have previously demonstrated the efficacy of intracoronary {beta}-brachytherapy using a liquid{sup 188}Re-filled balloon in a randomised trial including de novo lesions. Percutaneous coronary interventions in restenotic lesions and in stenoses of venous bypass grafts are characterised by a high recurrence rate for restenosis and re-interventions. Against this background, we wanted to assess the impact of intracoronary {beta}-brachytherapy using a liquid{sup 188}Re-filled balloon in restenotic lesions in native coronary arteries and venous bypass grafts. In 243 patients, {beta}-brachytherapy with 22.5 Gy was applied at a tissue depth of 0.5 mm. Patients were followed up angiographically after 6 months and clinically for 12 months. The primary clinical endpoint was the incidence of MACE (death, myocardial infarction, target vessel revascularisation). Secondary angiographic endpoints were late loss and binary restenosis rate in the total segment. All irradiation procedures were successfully performed. A total of 222 lesions were in native coronary arteries; 21 were bypass lesions. Mean irradiation length was 41.6{+-}17.3 mm (range 20-150 mm) in native coronary arteries and 48.1{+-}33.9 mm (range 30-180 mm) in bypass lesions; the reference diameter was 2.57{+-}0.52 mm and 2.83{+-}0.76 mm, respectively. There was no vessel thrombosis during antiplatelet therapy. Angiographic/clinical follow-up rate was 84%/100%. MACE rate was 17.6% in the native coronary artery group and 38.1% in the CABG group (p<0.03). Binary restenosis rate was 22.5% and 55.6% (p<0.01), and late loss was 0.38{+-}0.72 mm and 1.33{+-}1.11 mm (p<0.001), respectively. We conclude that intracoronary {beta}-brachytherapy with a liquid{sup 188}Re-filled balloon using 22.5 Gy at a tissue depth of 0.5 mm in restenotic lesions is safe. It is associated with a low binary restenosis rate, resulting in a low occurrence rate of MACE within 12 months in restenotic lesions in native coronary arteries but not in vein grafts. (orig.)

  9. Rhenium(V) and technetium(V) nitrido complexes with mixed tridentate π-donor and monodentate π-acceptor ligands.

    Boschi, Alessandra; Cazzola, Emiliano; Uccelli, Licia; Pasquali, Micol; Ferretti, Valeria; Bertolasi, Valerio; Duatti, Adriano


    Mixed-ligand [M(N)(SNS)(PPh(3))] complexes (M = Tc, Re) (1, 2) were prepared by reaction of the precursor [M(N)Cl(2)(PPh(3))(2)] with ligand 2,2'-dimercaptodiethylamine [H(2)SNS = NH(CH(2)CH(2)SH)(2)] in refluxing dichloromethane/ethanol mixtures. In these compounds, 2,2'-dimercaptodiethylamine acts as a dianionic tridentate chelating ligand bound to the [M≡N](2+) group through the two π-donor deprotonated sulfur atoms and the protonated amine nitrogen atom. Triphenylphosphine completes the coordination sphere, acting as a monodentate ligand. [M(N)(NS(2))(PPh(3))] complexes can assume two different isomeric forms depending on the syn and anti orientations of the hydrogen atom bound to the central nitrogen atom of the SNS ligand with respect to the M≡N moiety. X-ray crystallography of the syn isomer of complex 2 demonstrated that it has a distorted trigonal bipyramidal geometry with the nitrido group and the two sulfur atoms defining the equatorial plane, the phosphorus atom of the monophosphine and the protonated amine nitrogen of the tridentate ligand spanning the two reciprocal trans positions along the axis perpendicular to the trigonal plane. Synthesis of the analogous Tc derivatives with tris(2-cyanoethyl)phosphine, [Tc(N)(SNS)(PCN)] [(PCN = P(CH(2)CH(2)CN)(3)], required the preliminary preparation of the new precursor [Tc(N)(PCN)(2)Cl(2)](2) (3), which was prepared by reacting [n-NBu(4)][Tc(N)Cl(4)] with a high excess of PCN. The crystal structure of compound 3 consists of a noncrystallographic centrosymmetric dimer of Tc(V) nitrido complexes having an octahedral geometry. In this arrangement, the apical positions are occupied by two tris(2-cyanoethyl)phosphine groups and the equatorial positions by the nitrido group whereas the two Cl(-) anions and one cyano ligand belong to the other octahedral component of the dimer. By reacting the new precursor [Tc(N)(PCN)(2)Cl(2)](2) with the ligand H(2)SNS the complex [Tc(N)(SNS)(PCN)] (5) was finally obtained in acetonitrile solution. The new Tc(III) complex trans-[Tc(PCN)(2)Cl(4)][n-NBu(4)] (4) was also isolated from the reaction solution used for preparing complex 3 as side product and characterized by X-ray diffraction. The crystal structure of 4 consists of independent trans-[TcCl(4)(PCN)(2)](-) anions situated on crystallographic centers of symmetry and tetrabutylammonium cations in general positions.

  10. Surface morphology and deuterium retention in tungsten and tungsten–rhenium alloy exposed to low-energy, high flux D plasma

    Alimov, V.Kh., E-mail: [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Hatano, Y. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Sugiyama, K.; Balden, M. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany); Oyaidzu, M. [Fusion Research and Development Directorate, International Fusion Energy Research Center, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Akamaru, S. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Tada, K. [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579 (Japan); Kurishita, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Hayashi, T. [Fusion Research and Development Directorate, International Fusion Energy Research Center, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Matsuyama, M. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan)


    Highlights: • W and W–5%Re were exposed to low-energy, high flux D plasma at various temperatures. • The temperature dependences of the D retention in these two materials diverged. • It is suggested that ductility of W and W–5%Re materials influences the D retention. - Abstract: Surface topography and deuterium retention in polycrystalline hot-rolled W and W–5%Re have been examined after exposure to a low-energy (76 eV), high flux (around 10{sup 22} D/m{sup 2} s) deuterium plasma to an ion fluence of 10{sup 26} D/m{sup 2} at various temperatures. The methods used were confocal laser scanning microscopy and the D({sup 3}He, p){sup 4}He nuclear reaction at {sup 3}He energies varied from 0.69 to 4.0 MeV. During exposure to the D plasma at temperatures in the range from 348 to 673 K, small blisters of size in the range from about 1 to about 15 μm, depending on the exposure temperature, are formed on the W and W–5%Re surfaces. In the W–5%Re, the deuterium retention demonstrates its maximum at exposure temperature of 463 K, while in the W this maximum is shifted to 523 K. A difference in the temperature dependence of the D retention for the W and W–5%Re is explained, as a rough approximation, by temperature dependences of the ductility of these materials.

  11. Reactions during melting of low-activity waste glasses and their effects on the retention of rhenium as a surrogate for technetium-99

    Jin, Tongan; Kim, Dong-Sang; Tucker, Abigail E.; Schweiger, Michael J.; Kruger, Albert A.


    Volatile loss of radioactive 99Tc to offgas is a concern with processing the low-activity waste (LAW) at Hanford site. We investigated the partitioning and incorporation of Re (a nonradioactive surrogate for 99Tc) into the glass melt during crucible melting of two simulated LAW feeds that resulted in a large difference in 99mTc/Re retention in glass from the small-scale melter tests. Each feed was prepared from a simulated liquid LAW and chemical and mineral additives (boric acid, silica sand, etc.). The as-mixed slurry feeds were dried at 105°C and heated to 600–1100°C at 5 K/min. The dried feeds and heat treated samples were leached with deionized water for 10 min at room temperature followed by 24-h leaching at 80°C. Chemical compositions of the resulting solutions and insoluble solids were analyzed. Volume expansion measurement and X-ray diffraction were performed on dried feeds and heat treated samples to characterize the progress of feed-to-glass conversion reactions. It was found that the incorporation of Re into glass melt virtually completed during the major feed-to-glass conversion reactions were going on at ≤ 700°C. The present results suggest that the different composition of the salt phase is responsible for the large difference in Re incorporation into glass melt during early stages of glass melting at ≤ 700°C. Additional studies with modified and simplified feeds are underway to understand the details on how the different salt composition affects the Re incorporation.


    electron beam melting into a 1.5-in.-diam ingot. The cast ingot had an average hardness of 317 VHN. The ingot was machined by grinding to remove surface...heliarc welded to orm an electrode for electron beam melting into a 1.5-in.-diam ingot. The cast ingot had an average hardness of 317 VHN. The ingot was

  13. Accumulation of the $^{178m2}Hf$ Isomeric Nuclei Through Spallation with Intermediate-Energy Protons of Tantalum and Rhenium Targets

    Karamian, S A; Adam, J; Filossofov, D V; Henzlova, D; Henzl, V; Kalinnikov, V G; Lebedev, N A; Novgorodov, A F; Collins, C B; Popescu, I I; Ur, C A


    The productivity of the spallation reactions at proton energies of 100-660 MeV for accumulation of the radioactive isotopes and isomers has been studied experimentally. Spectra of Ta and Re targets activated at Dubna synchrocyclotron were measured using the methods of radiochemistry and gamma-spectroscopy. Many radioactive products of the spallation and fission reactions are identified, and their yields are compared with the LAHET code simulations. Cross sections, \\sigma_m and isomer-to-ground state ratios, \\sigma_m/\\sigma_g are deduced for nuclear isomers, in particular, for high-spin isomers, as ^{179m2}Hf, ^{179m2}Hf and ^{177m2}Lu. Spin distributions for the spallation-residue nuclei are estimated to understand the \\sigma_m/\\sigma_g ratios. Possibilities to optimize the methods for the long-lived isomers production are discussed, and it would be a necessary step on the way to accumulate such exotic radionuclides in milligram amount under reasonable cost and radiation safety conditions.

  14. Effect of alloying by lanthanum and high rhenium superalloys on the basis of Ni-Al-Cr on the structure and phase composition

    Kozlov, Eduard, E-mail:; Tsedrik, Elena, E-mail:; Koneva, Nina, E-mail: [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Popova, Natalya, E-mail: [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Institute of Strength Physics and Materials Science, SB RAS, 2/4, Academicheskii Av., 634055, Tomsk (Russian Federation); Nikonenko, Elena, E-mail: [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Av., 634050, Tomsk (Russian Federation); Fedoricheva, Marina, E-mail: [Institute of Strength Physics and Materials Science, SB RAS, 2/4, Academicheskii Av., 634055, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Av., 634050, Tomsk (Russian Federation)


    This paper presents transmission and scanning electronic microscope investigations of Ni-Al-Cr superalloy alloyed with additional Re and La elements. This superalloy is obtained by the directional solidification method and subsequently is subjected to two-stage high-temperature annealing: 1) at T = 1150°C, the test time is 1 hour; 2) at T = 1100°C, the testing time is 1430 hours. It was found that the γ- and γ′-phases are the main phases in the two states on the basis of fcc lattice. Where γ is the disordered fcc solid solution and γ′-phase is the main phase with an ordered arrangement of atoms having the L1{sub 2} superstructure. It is shown that such additional elements as Re and La result in the formation of new phases in Ni-Al-Cr accompanied by considerable modifications of quasi-cuboid structure in its γ′-phase. The phase composition and morphology of the phases are studied.

  15. Development of high-specific-activity (68)Ga-labeled DOTA-rhenium-cyclized alpha-MSH peptide analog to target MC1 receptors overexpressed by melanoma tumors.

    Cantorias, Melchor V; Figueroa, Said D; Quinn, Thomas P; Lever, John R; Hoffman, Timothy J; Watkinson, Lisa D; Carmack, Terry L; Cutler, Cathy S


    A previous report on (68)Ga-1,4,7,10-tetraazacyclodedecane-N,N',N'',N'''-tetraacetic acid (DOTA)-Re(Arg(11))CCMSH was shown to indicate the imaging agent's potency for early detection of metastatic melanoma. However, the main limiting factor to developing high-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH is the short half-life of (68)Ga, which precludes further purification of the agent. To circumvent this problem, we incorporated the microwave technique to rapidly radiolabel the peptide with (68)Ga, thereby allowing enough time to include high-performance liquid chromatography (HPLC) purification in the overall procedure. DOTA-Re(Arg(11))CCMSH was radiolabeled with (68)Ga in 68)Ga-DOTA-Re(Arg(11))CCMSH was then administered on B16/F1 murine melanoma-bearing C57 mice to study its biodistribution and positron emission tomography (PET) imaging capability. The production of high-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH resulted in an improved tumor uptake [6.93+/-1.11%ID/g at 30 min postinjection (p.i.) and 6.27+/-1.60%ID/g at 1 h p.i.] and tumor retention (5.85+/-1.32%ID/g at 4 h p.i.). Receptor-mediated tumor uptake was verified by blocking studies. Furthermore, high-resolution PET images of the tumor were obtained, owing to high tumor-to-nontarget organ ratios at an early time point (i.e., at 1 h biodistribution: tumor/blood, 14.3; tumor/muscle, 89.6; tumor/skin, 12.3) and fast clearance of the labeled peptide from kidney and other healthy tissues. High-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH may have a potential role in the early diagnosis of metastasized melanoma.

  16. New Rhenium-Doped SrCo1−xRexO3−δ Perovskites Performing as Cathodes in Solid Oxide Fuel Cells

    Loreto Troncoso


    Full Text Available In the aim to stabilize novel three-dimensional perovskite oxides based upon SrCoO3−δ, we have designed and prepared SrCo1−xRexO3−δ phases (x = 0.05 and 0.10, successfully avoiding the competitive hexagonal 2H polytypes. Their performance as cathode materials in intermediate-temperature solid oxide fuel cells (IT-SOFC has been investigated. The characterization of these oxides included X-ray (XRD and in situ temperature-dependent neutron powder diffraction (NPD experiments for x = 0.10. At room temperature, SrCo1−xRexO3−δ perovskites are defined in the P4/mmm space group, which corresponds to a subtle tetragonal perovskite superstructure with unit-cell parameters a = b ≈ ao, c = 2ao (ao = 3.861 and 3.868 Å, for x = 0.05 and 0.10, respectively. The crystal structure evolves above 380 °C to a simple cubic perovskite unit cell, as observed from in-situ NPD data. The electrical conductivity gave maximum values of 43.5 S·cm−1 and 51.6 S·cm−1 for x = 0.05 and x = 0.10, respectively, at 850 °C. The area specific resistance (ASR polarization resistance determined in symmetrical cells is as low as 0.087 Ω·cm2 and 0.065 Ω·cm2 for x = 0.05 and x = 0.10, respectively, at 850 °C. In single test cells these materials generated a maximum power of around 0.6 W/cm2 at 850 °C with pure H2 as a fuel, in an electrolyte-supported configuration with La0.8Sr0.2Ga0.83Mg0.17O3−δ (LSGM as the electrolyte. Therefore, we propose the SrCo1−xRexO3−δ (x = 0.10 and 0.05 perovskite oxides as promising candidates for cathodes in IT-SOFC.

  17. Metodo integrado para la gestion de Universidades basado en el Balanced Scorecard (bsc y el modelo europeo de calidad (efqm: caso U.C.S.M.

    Horacio Vicente Barreda Tamayo


    Full Text Available El presente Trabajo realiza la propuesta de un Método Integrado que permite mejorar la competitividad en la Gestión de las Universidades, este método se basa: En una herramienta de Gestión Estratégica: el Balanced Scorecard (BSC, que fue creada por Kaplan y Norton en 1992; y En el Modelo Europeo de Calidad (EFQM, que fue desarrollado como un Modelo de Excelencia en 1991. La metodología utilizada consiste en analizar las características, ventajas y limitaciones del BSC y el EFQM para aplicarlos simultáneamente en la gestión de Tomando como base los 9 criterios del EFQM, se desarrolla un Mapa Estratégico del BSC, para que se alineen todas las perspectivas hacia el logro de los Objetivos Estratégicos de la Organización. El método integrado planteado se aplica en el caso de la Universidad Católica de Santa María (Arequipa- Perú, donde se analiza las ventajas que implicaría la implementación del mismo.

  18. C/S与B/S混合软件体系结构模型%C/S and B/S Mixed Software Architecture Model

    张友生; 陈松乔



  19. Program Efficiency of Database Application with C/S Model%C/S模式数据库应用的程序效率研究

    张兴亮; 姚进; 董军辉



  20. Intelligence upgrade of management information system with C/S model%C/S模式管理信息系统的智能升级

    刘俊; 张智光



  1. C/S模式信息系统的安全性控制策略%A Security Strategy of Information System Based on C/S Model

    唐成华; 陈新度; 何圣华



  2. C/S模式下电子白板系统的设计与实现%Design and Implementation of Whiteboard in C/S Model

    顾俊杰; 曹宁



  3. MVC架构模式在C/S系统中的应用%Apply MVC Architecture Pattern to C/S System

    曹爽; 贾素玲



  4. Cistatina C sérica: uma alternativa prática para avaliação de função renal?

    Ivana Cláudia Gabriel


    Full Text Available A taxa de filtração glomerular é o principal indicador de função renal em indivíduos saudáveis e doentes. Apesar de todo o desenvolvimento da medicina em nossos dias, ainda há dificuldade para definir-se essa taxa com precisão na prática diária. Marcadores precoces de lesão renal são importantes, porque a taxa de filtração glomerular se reduz antes do aparecimento dos sintomas ou sinais de insuficiência renal. A cistatina C tem sido apontada como uma alternativa, mas ainda não foi testada em muitas condições. Vantagens e desvantagens desse marcador foram aqui discutidas. Embora a determinação sérica da cistatina C comece a ser usada na prática clínica em todo o mundo, ainda não foram completamente esclarecidas suas limitações ou as situações em que está de fato indicada sua aplicação; por outro lado, a creatinina sérica (e sua depuração é um marcador laboratorial facilmente acessível, de baixo custo, cujas limitações são bem conhecidas, que pode ser usado de forma rotineira para avaliação de função renal.

  5. Effect of Material Ion Exchanges on the Mechanical Stiffness Properties and Shear Deformation of Hydrated Cement Material Chemistry Structure C-S-H Jennit - A Computational Modeling Study


    performance. Journal of Advanced Concrete Technology , 2003. 1(2): p. 91-126. 11. Martín-Sedeño, M.C., et al., Aluminum-rich belite sulfoaluminate cements...85 33. Bussi , G. and M. Parrinello, Stochastic thermostats: comparison of local and global schemes. Computer Physics Communications, 2008. 179

  6. Study C ++ 's Reference and its Applications in the Object- Oriented Programming%C++面向对象程序设计中引用的使用




  7. Inventario de creencias del supervisor (I.C.S: un instrumento para estudiar los diferentes estilos de supervisión



    Full Text Available RESUMEN: El objetivo de este trabajo es presentar un inventario acerca de las creencias y opiniones de los profesores que asumen papeles de ayuda, guía y orientación de profesores principiantes como parte importante de los programas de formación para estos profesores noveles. El Inventario nos permite conocer qué estilo de supervisión predomina en estos profesores mentores cuando trabajan con profesores que se encuentran en sus primeros años de docencia. El documento asume que los profesores mentores creen y actúan de acuerdo con una de las tres orientaciones de supervisión: Directiva, Colaborativa y No Directiva. El artículo describe el Inventario de Creencias del Supervisor así como el proceso de validación y los hallazgos obtenidos tras su aplicación a un grupo de profesores con experiencia que participaron en un curso de Formación en Estrategias de Supervisión.ABSTRACT: The aim of this work is to offer an inventory of the beliefs and opinions of teachers who act as supervisors, guides and orientors for novice teachers as an important aspect in the training programs for such professionals. The inventory discloses the predominant supervisory styles of such mentor teachers when they are working with teachers in the first years of their duties. The work assumes that mentor teachers hold beliefs and act in accordance with one of three supervisory orientations: Directive, Collaborative and Non-Directive The paper describes the I.S.B. and the process of validation and the findings obtained after application to a group of teachers with experience who participated in a course on Training in Supervisory Strategies.RÉSUMÉ: L'objectif de ce travail est de dresser un inventaire -á l'intérieur des programmes de formation- des croyances et des opinions des professeurs assumant le role d'aide, de guide et d'orientation envers les professeurs débutants . I/inventaire nous permet de savoir quel type d'inspection predomine chez ees professeurs mentors lorsqu'ils travaillent avec de jeunes enseignants. Le document atteste que les professeurs mentors croient et agissent suivant Tune de ees trois orientations de controle: Directive, Collaboration et Non Directive. L'article décrit Llnventaire des Croyances du Contróleur ainsi que le processus de validation et les résultats obtenus aprés son application á un groupe de professeurs experimentes qui participérent a un cours de Formation en Stratégies de Controle.

  8. The phylogeny of C/S1 bZIP transcription factors reveals a shared algal ancestry and the pre-angiosperm translational regulation of S1 transcripts

    Peviani, Alessia; Lastdrager, Jeroen; Hanson, Johannes; Snel, Berend


    Basic leucine zippers (bZIPs) form a large plant transcription factor family. C and S1 bZIP groups can heterodimerize, fulfilling crucial roles in seed development and stress response. S1 sequences also harbor a unique regulatory mechanism, termed Sucrose-Induced Repression of Translation (SIRT). Th

  9. Design and implementation of WMS based on C/S structure%基于C/S结构的WMS的设计与实现

    张兰华; 吴耀华; 张健



  10. Effect of three cooking methods on nutrient components and antioxidant capacities of bamboo shootPhyllostachys praecox C.D.Chu et C.S.Chao

    Jin-jie ZHANG; Rong JI; Ya-qin HU; Jian-chu CHEN; Xing-qian YE


    Three cooking methods,namely boiling,steaming,and stir-frying for 5 to 10 min,were used to evaluate the effect on nutrient components,free amino acids,L-ascorbic acid,total phenolic contents,and antioxidant capacities of bamboo shoots (Phyllostachys praecox).Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents of protein,soluble sugar,and ash,and caused a great loss in the total free amino acids (decreased by 38.35% and 34.86%,respectively).Significant differences (P<0.05) in free amino acids were observed in the samples cooked by different methods.Stir-fried bamboo shoots had a high fat content which increased by 528.57% because of the addition of edible oil.After boiling,the L-ascorbic acid and total phenolic contents were significantly reduced,while steaming increased total phenolic content by 3.98% and stir-frying well-preserved L-ascorbic acid (78.87% of its previous content).Results of the antioxidative property study showed that stir-frying could increase antioxidant capacities of bamboo shoots.It is concluded that stir-frying is more suitable for bamboo shoots because it could obtain the maximum retention of antioxidant capacities.

  11. Design and Realization of Multimedia Classroom MIS on C/S%基于C/S模式的多媒体教室MIS的设计与实现



    多媒体教室管理是高校现代教育技术部管理中的重要环节,管理的质量直接关系到高校多媒体教室为高校教学服务的效率.结合高校多媒体教室管理的实际需求,分析多媒体教室管理平台的基本框架,给出该平台的设计思路.采用PHP作为开发平台,以PHP+MySQL为其开发技术,设计基于B/S结构的高校多媒体教室管理平台.%Multimedia classroom management is one of the import segments in modern educational technologydepartment in university. The quality management relates to the efficiency that university multimediaclassroom to serve the education in colleges and universities. Based on the Physical demand of multimediaclassroom management,this paper aims to analyze basic framework of multimedia classroom management,to give the layout idea about the platform,to use PHP as development platform,to use PHP+MySQL asdevelopment technique,to design the university multimedia classroom platform of B/S

  12. Design and Implementation of N -Tier C/S Database of Delphi%Delphi的N-Tier数据库的设计与实现

    王晓鹏; 王晓蒲



  13. Seismic activity at the Las Tres Virgenes, B. C. S, Mexico, geothermal field. Actividad sismica del campo geotermico de Las Tres Virgenes, Baja California Sur, Mexico

    Guerrero Guadarrama, Jose Luis (Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico))


    A study of the seismic activity at Las Tres Virgenes Geothermal field in Baja California Sur (Baja California Sur), Mexico is presented. Four monitoring periods are comprised: 28 January to 12 May 1993; 5 January to 24 April 1994; 25 May to 19 August 1995 and 30 August to 02 November 1995. The influence of the geological structure on the seismic activity of the field was considered by means of: a velocities model based on field geology, borehole data, a reflection seismic profile, considerations on the thermal gradient in the zone, and local and regional geophysical models. Site corrections that were considered necessary to improve the velocities model were determined trough simulation runs of seismic events at 4 km depth with reference to sea level and to a mean topographic height of 400 m. Main interpretation consists in the correlation of epicenters with the volcanic edifices and tectonics, identifying the maximum activity zones related with geothermal interest areas. Registered seismic information constitutes a framework for the study of the future seismic activity during reservoir exploitation.

  14. Over taalkwesties in de Europese Unie en de kunst van het juridisch vertalen : en beschouwing naar aanleiding van I. Sumner and H.C.S. Warendorf

    X.E. Kramer (Xandra)


    textabstractIn deze bijdrage wordt naar aanleiding van het verschijnen van een Engelse vertaling van Boek I BW en aanverwante wetten (Sumner en Warendorf, 2003) en Boek IV BW en aanverwante wetten (Sumner en Warendorf, 2005) aandacht besteed aan de rol van taal en vertalingen bij de harmonisatie van

  15. 基于C/S架构的电子教室管理系统%Management System of Electronic Classroom Based on C/S Architecture

    杨帆; 沈来信


    In order to implement electronic management of laboratory and computer room,an electronic classroom system is developed, which can manage students, devices and teaching process. The system can also supervise the student class situation, and urge teacher teaching,and monitor PC machine condition,and manage electric equipment. The teaching monitoring network is constructed to obtain check-in data of students in class,assessment data of teachers’ teaching quality,and damage data of computer hardware. The system im-plements main functions including screen broadcast,remote assistance,command execute,client lock,information publishing,computer re-start,auto check,group session,document transfer,assignment and submiting,and equipment monitoring. Multicast techniques are used to finish the communication between server and multi-clients,and the connector number of TCP can be used to verify client online. MVC layered structure is utilized to realize the 3-layers architecture and data interaction,which can efficiently improve the security of data and reusability of module. The system can be extended to large-scale experimental environments,effectively improving the scientific manage-ment level of electronic classroom.%为实现实验室、机房的电子化管理而开发的电子教室系统,可以对学生、设备和教学过程进行管理,系统还可以用于学生上课情况监督、教师教学督促、PC机状态监控、电子设备运用管理等。构建教学监控网络获取学生上课的考勤数据、教师教学质量的评估数据、机房硬件的损坏数据等。系统主要功能有屏幕广播、远程协助、执行命令、锁定客户端、信息发布、机器重启、自动签到、群组会话、文件传送、作业发布与上交、客户端屏幕监控、设备监控等。使用组播技术完成服务器与多客户端的通信,通过TCP连接数完成客户端在线验证等。利用MVC分层结构完成系统三层架构和数据交互实现,有效提高了数据的安全性和模块的可复用性。系统可以高效地扩展到大规模的实验环境,有效提高电子教室的科学化管理水平。

  16. Evaluación del efecto del grano de soya crudo (C.S.C. suministrado por 42-28 o 14 semanas a aves en postura

    López G. Arnobio


    Full Text Available An experiment was conducted with 144 middle weight Dekalb-Warren laying hens (28 to 70 weeks age, to evaluate the effects on feed consumption, % egg production, egg weight feed conversion per dozen and kilogram of egg produced, weight change, and pancreas size and weight due to the feeding of who le raw soybean (WRSB replacing soybean bean (SBM as a protein source in the diet in three feeding periods (42,28 and 14 weeks. There were no differences (P<0.05 due to protein sources used on egg weight, feed conversion per dozen and kilogram of egg produced and pancreas size. However, there were differences on egg production, weight change, feed consumption by hen per day and pancreas weight. Also there on differences (P < 0.05 due to feeding period on egg weight, feed conversion by dozen and kilograms of egg produced and pancreas weight, but there were differences (P<0.05 on egg production and pancreas size. In a similar way, there where no differences (P<0.05 to the interaction of protein sources feeding periods for any of the variables considerated.Un experimento se llevó a cabo con 144 gallinas Dekalb-Warren semipesadas en postura (28 a 70 semanas para evaluar los efectos de reemplazar la torta de soya por el grano de soya crudo (G.S.C suministrada por tres períodos de tiempo diferentes(42, 28 y 14 semanas. No hubo diferencias (P <0.05 por efecto de la fuente de proteína para las variables peso de huevo, eficiencia de conversión por docena y kilogramo de huevo producido y tamaño de pancreas. Sin embargo si hubo diferencias (P < 0.05 para el porcentaje de producción, cambio de peso en las aves, consumo de alimento por ave día y peso del páncreas. Tampoco se encontraron diferencias (P<0.05 por efecto del período de tiempo de suministro para las variables cambio de peso en las aves, peso de huevo, eficiencia de conversión por docena y kilogramo de huevo producido y peso del páncreas. Pero si hubo diferencias (P< Q05 para las variables porcentaje de producción y tamaño del páncreas. No se observaron diferencias (P< 0.05 por efecto de la interacción fuente de proteína por período de tiempo de suministro para ninguna de las variables consideradas.

  17. A study on the influence of trace elements (C, S, B, Al, N) on the hot ductility of the high purity austenitic alloy Fe-Ni 36% (INVAR)

    Simonetta-Perrot, M.T.


    In order to study the damage mechanisms leading to the ductility decrease of the Invar alloy at 600 C, a high-purity Fe-Ni 36% sample has been doped with trace elements with the purpose of identifying the role of sulfur, sulfur with Al N or B N precipitates and sulfur with boron, on the ductility, the failure modes, the intergranular damage and the plastic deformation mechanisms prior to failure. A new AES segregation quantification method has been used to study the kinetics and thermodynamics of intergranular and surface segregations and determine the relation between sulfur segregation and grain joint fragility. refs., figs., tabs.

  18. 基于C/S的视频车辆检测系统设计%Design of video vehicle detection system based on C/S



    The detection and tracking of vehicles in video streaming,can accurately count traffic information,timely give an alarm for traffic and make accurate analysis of traffic congestion to alleviate traffic jam.The real-time analysis of the traffic transportation vehicle data,it can help to adjust the vehicle through the intersection of time,increase the traffic flow in a section of the road, to alleviate traffic pressure.%通过对视频流中的车辆进行检测和跟踪,可以准确地统计交通信息,及时的对交通事件报警,对交通路段拥堵情况做出准确的分析,有效缓解交通堵塞。实时分析交通路段通行车辆的数据,有助于调整车辆通过路口时间,加大某路段的通行流量,缓解道路交通压力。


    morteza rezaee


    Full Text Available Abstract One of the most important purposes of any organization is to attract customer satisfaction and service recipients through offering services with high quality. Organizations by different ways to obtain the reasonable demand and legal requirements, then due to these service demands, response appropriately (Ziviar Farzad, 1390. Factors such as accelerating office works associated with suitable/ healthy behavior and accuracy in customer demands has a great importance, While it cause the clients to be satisfied. The administrative system of Iran, however, the religious matters are included in all organizations and offices according to our Islamic leader command. These overall policies have been notified to administrative system and upstream documentation like development plan regulation and civil service management code. Thus, the main principle is that the employees consider clients and customers like their own self, which means act and behave like what they expect for themselves. This survey is a field study. The research method is descriptive – analytic as well as inferential. In fact, samples have chosen from the clients attending to Isfahan department of physical education during the years, 1384 to 1390. Data collected through filling out the questionnaire by the clients. So the satisfaction was evaluated through six years. Sample selection was completely random from men and women attending to the department. All the required data analyzed and categorized by SPSS techniques. Therefore, this study is done descriptively to explain the objective and accurate systematic of facts happen in our sample. Findings of this survey show that the satisfaction of clients in the department of physical education has decreasing trend during the years, 1385 to 1390. the average satisfaction during these years is 76,25 that is less than the average satisfaction in Isfahan province in the same year. Statistics also show that the top rated ( or high score belongs to the quality of employees ' behavior in dealing with customers and the lowest score belongs to lack of physical equipments and enough space. Key words: functional evaluation, satisfaction, Isfahan department of physical education, csm model (customer satisfaction measurement.

  20. Leer en áreas de conocimiento: la experiencia en la Facultad de C s. Médicas, U.N.C .

    Daniela Moyetta


    Full Text Available En el contexto universitario los alumnos ingresantes se confrontan con géneros discursivos que suponen prácticas de lectura específicas, no siempre explícitas (Carlino, 2005. De ahí que interpretar correctamente los contenidos de los textos de especialidad requiera competencias estratégicas, léxico- gramaticales y discursivas, de las que los estudiantes podrán apropiarse si son acompañados por docentes que modelen e incentiven los modos de lectura esperados en el nivel superior y, particularmente, del objeto de estudio. Este ensayo presenta y describe el proyecto llevado a cabo durante el Ciclo de Nivelación en la Facultad de Cs. Médicas (Universidad Nacional de Córdoba para implementar modos de ayudar a los aspirantes a leer en el contexto universitario en forma comprensiva y reflexiva. La experiencia contempló cuatro momentos: capacitación docente, clase a los aspirantes, diseño de actividades de lectocomprensión e integración de contenidos curriculares con actividades que propiciaron modos de lectura propios del contexto académico. Este artículo de reflexión basado en investigación argumenta en favor de que los profesores expliciten los saberes que la cultura académica presupone, para lo que precisan, a su vez, el apoyo de las instituciones.