Some radiation protection problems connected with the use of 186Re-HEDP and 153Sm-EDTMP for palliative therapy of of bone metastases

International Nuclear Information System (INIS)

Husak, V.; Myslivecek, M.

1995-01-01

The aim of this paper was to assess whether the ambulatory (outpatient) therapy with 186 Re-HEDP and 153 Sm-EDTMP is possible in the Czech Republic. Physical characteristics, administered activity, biokinetics of radiopharmaceuticals, radiation protection characteristics, irradiation of patients relatives as well as comparison with limits for rhenium-186 and samarium-153 radiopharmaceuticals are given. The outpatient administration of 186 Re-HEDP and 153 Sm-EDTMP with the subsequent keeping the patient for 6 hours in a department of nuclear medicine appears to be in compliance with regulations proposed in the Czech Republic as well as ICRP Recommendations. (J.K.) 1 tab., 12 refs

Some radiation protection problems connected with the use of 186Re-HEDP and 153Sm-EDTMP for palliative therapy of of bone metastases

Energy Technology Data Exchange (ETDEWEB)

Husak, V; Myslivecek, M [Univ. Hospital, Olomouc (Czech Republic). Department of Nuclear Medicine

1996-12-31

The aim of this paper was to assess whether the ambulatory (outpatient) therapy with {sup 186}Re-HEDP and {sup 153}Sm-EDTMP is possible in the Czech Republic. Physical characteristics, administered activity, biokinetics of radiopharmaceuticals, radiation protection characteristics, irradiation of patients relatives as well as comparison with limits for rhenium-186 and samarium-153 radiopharmaceuticals are given. The outpatient administration of {sup 186}Re-HEDP and {sup 153}Sm-EDTMP with the subsequent keeping the patient for 6 hours in a department of nuclear medicine appears to be in compliance with regulations proposed in the Czech Republic as well as ICRP Recommendations. (J.K.) 1 tab., 12 refs.

Rhenium Re

International Nuclear Information System (INIS)

Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

1978-01-01

The basic methods for determining rhenium in various objects are presented. The gravimetric determination of rhenium is based on a quantitative precipitation of ReO 4 - ions with tetraphenylarsonium chloride. The determination is not hindered by tungstates and molybdates. The potentiometric determination of rhenium in alloys (>=0.5% Re) is based on perrhenate ion reduction to Re(4) with the titrated solution of the Cr(2) salt. Re(7) is titrated in a hot sulfuric acid solution in the presence of KJ. The relative error of the method is 1 to 3%. The photometric determination of rhenium is performed by the rhodamide method in molybdenum-and tungsten-containing alloys and catalytically, in rocks, after it has been separated in the form of sulfide. The extraction-photometric determination of rhenium is carried out with the aid of methyl violet (analysis of a stock with a high content of Mo, W, Ta, Nb, Ti ahd Zr) and thio-oxine (the determination of Re is hindered by Au, Pt, Pd, Ru, Os, Rh, Ir). Also described are methods for differential-spectrophotometric determination of Re with the aid of thiocarbamide, as well as with the aid of dimethylglyoxime in the presence of SnCl 2 in an acid medium when Re is determined in its alloys with niobium and hafnium. It takes 2 hours to analyze the Hf-Re alloy and 3 hours to analyze the Nb-Re alloy, the standard deviation being 0.005 at 30-50% Re and 0.027 to 0.019 at 10-50% Re

Electrochemical behaviour of rhenium-graphite electrode

International Nuclear Information System (INIS)

Varypaev, V.N.; Krasikov, V.L.

1980-01-01

Electrochemical behaviour of combination electrode from graphite with electrodeposited thin coating of electrolytic rhenium is studied. Solution of 0.5 m NaCl+0.04 m AlCl 3 served as an electrolite. Polarization galvanostatic curves of hydrogen evolution upon electrodes with conditional rhenium thickness of 3.5 and 0.35 μm, 35 and 3.5 nm are obtained. Possibility of preparation of rhenium-graphite cathode with extremely low rhenium consume, electro-chemical properties of which are simu-lar to purely rhenium cathode is shown. Such electrode is characterized with stable in time low cathode potential of hydrogen evolution in chloride electrolyte and during cathode polarization it is not affected by corrosion

Pharmacokinetics and normal organ dosimetry following intraperitoneal rhenium-186-labeled monoclonal antibody

International Nuclear Information System (INIS)

Breitz, H.B.; Durham, J.S.; Fisher, D.R.

1995-01-01

Pharmacokinetics, biodistribution and radiation dose estimates following intraperitoneal administration of a 186 Re-labeled murine antibody, NR-LU-10, were assessed in 27 patients with advanced ovarian cancer. Quantitative gamma camera imaging and gamma counting of serum and intraperitoneal fluid radioactivity were used to obtain data for dosimetry estimation. The MIRD intraperitoneal model was used to estimate dose to normal organs from radioactivity within the peritoneal cavity. The absorbed dose to normal peritoneum was estimated in two ways: from the gamma camera activity and peritoneal fluid samples. Serum activity peaked at 44 hr and depended on the concentration of radioactivity in the peritoneal fluid. Mean cumulative urinary excretion of 186 Re was 50% by 140 hr. Estimates of radiation absorbed dose to normal organs in rad/mCi administered (mean ± s.d.) were whole body 0.7 ± 0.3; marrow 0.4 ±0.1; liver 1.9 ±0.9; lungs 1.3 ± 0.7; kidneys 0.2 ± 0.2; intestine 0.2 ±0.2. Peritoneal surface dose estimates varied depending on the volume of fluid infused and the method of dose determination. Using gamma camera data, the peritoneal dose ranged for 7 to 36 rad/mCi. Using peritoneal fluid sample data, the dose ranged from 2 to 25 rad/mCi. Significant myelosuppression was observed at marrow doses above 100 rad. Noninvasive methods of dose estimation for intraperitoneal administration of radioimmunoconjugates provide reasonable estimates when compared with previously described methods. 31 refs., 6 figs., 2 tabs

Rhenium Rocket Manufacturing Technology

Science.gov (United States)

1997-01-01

The NASA Lewis Research Center's On-Board Propulsion Branch has a research and technology program to develop high-temperature (2200 C), iridium-coated rhenium rocket chamber materials for radiation-cooled rockets in satellite propulsion systems. Although successful material demonstrations have gained much industry interest, acceptance of the technology has been hindered by a lack of demonstrated joining technologies and a sparse materials property data base. To alleviate these concerns, we fabricated rhenium to C-103 alloy joints by three methods: explosive bonding, diffusion bonding, and brazing. The joints were tested by simulating their incorporation into a structure by welding and by simulating high-temperature operation. Test results show that the shear strength of the joints degrades with welding and elevated temperature operation but that it is adequate for the application. Rhenium is known to form brittle intermetallics with a number of elements, and this phenomena is suspected to cause the strength degradation. Further bonding tests with a tantalum diffusion barrier between the rhenium and C-103 is planned to prevent the formation of brittle intermetallics.

Near-Net Shape Powder Metallurgy Rhenium Thruster

Science.gov (United States)

Leonhardt, Todd; Hamister, Mark; Carlen, Jan C.; Biaglow, James; Reed, Brian

2001-01-01

This paper describes the development of a method to produce a near-net shape (NNS) powder metallurgy (PM) rhenium combustion chamber of the size 445 N (100 lbf) used in a high performance liquid apogee engine. These engines are used in low earth Orbit and geostationary orbit for satellite positioning systems. The developments in near-net shape powder metallurgy rhenium combustion chambers reported in this paper will reduce manufacturing cost of the rhenium chambers by 25 percent, and reduce the manufacturing time by 30 to 40 percent. The quantity of rhenium metal powder used to produce a rhenium chamber is reduced by approximately 70 percent and the subsequent reduction in machining schedule and costs is nearly 50 percent.

Directed light fabrication of rhenium components

Energy Technology Data Exchange (ETDEWEB)

Milewski, J.O.; Thoma, D.J.; Lewis, G.K.

1997-02-01

Directed Light Fabrication (DLF) is a direct metal deposition process that fuses powder, delivered by gas into the focal zone of a high powered laser beam to form fully dense near-net shaped components. This is accomplished in one step without the use of molds, dies, forming, pressing, sintering or forging equipment. DLF is performed in a high purity inert environment free from the contaminants associated with conventional processing such as oxide and carbon pickup, lubricants, binding agents, cooling or cleaning agents. Applications using rhenium have historically been limited in part by its workability and cost. This study demonstrates the ability to fuse rhenium metal powder, using a DLF machine, into free standing rods and describes the associated parameter study. Microstructural comparisons between DLF deposited rhenium and commercial rhenium sheet product is performed. This research combined with existing DLF technology demonstrates the feasibility of forming complex rhenium, metal shapes directly from powder.

Thermal conduction and linear expansion of sintered rhenium and tungsten-rhenium alloys at a temperature up to 1000 K

International Nuclear Information System (INIS)

Pozdnyak, N.Z.; Belyaev, R.A.; Vavilov, Yu.V.; Vinogradov, Yu.G.; Serykh, G.M.

1978-01-01

Preparation technology (by powder metallurgy methods) of sintered rhenium and tungsten-rhenium VR-5, VR-10, and VR-20 alloys is described. Thermal conduction of rhenium and VR-20 alloy has been measured in the temperature range from 300 to 1000 K. The value obtained turned out to be considerably less than those published elsewhere, this testifies to the great thermal contact resistance between the material grains. Also measured is the mean linear expansion coefficient for the mentioned above materials in the same temperature range. Linear expansion increases with rhenium content increase

Rhenium-osmium geochemistry: method and applications

International Nuclear Information System (INIS)

Luck, J.M.

1982-03-01

Experimental methods for chemical separation and isotopic analysis of rhenium-osmium are described. Accurate determinations are obtained for a quantity ratio around 10 -6 -10 -7 g. Development as a geochemical tracer is examined. Study of rhenium-osmium in meteorites allows the determination of solar system chronology and age of the galaxy. Rhenium-osmium chronology in meteorites is improved and osmium isotopes are used as petrogenetic and geological tracers. Molybdenites are studied through 187 Re- 187 Os dating [fr

Crystallochemistry of rhenium compounds with metal-metal bonds

International Nuclear Information System (INIS)

Koz'min, P.A.; Surazhskaya, M.D.

1980-01-01

A review is presented including a brief description of atomic structure of 59 coordination rhenium compounds with metal-metal bond. The most important bond lengths and valent angles are presented for each compound. The dependence of rhenium-rhenium bond length on its multiplicity is discussed and possible causes of deviations from this dependence (namely, axial ligand presence, steric repulsion of ligands) are considered. On the basis of qualitative comparison of electronegativity of ligands in dimer compounds with quarternary bond of rhenium-rhenium a supposition is made on the influence of formal charge of atomic group and summary electro-negativity of ligands on the possibility of the metal-metal bond formation

Rhenium Nanochemistry for Catalyst Preparation

Directory of Open Access Journals (Sweden)

Vadim G. Kessler

2012-08-01

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.

Rhenium corrosion in chloride melts

International Nuclear Information System (INIS)

Stepanov, A.D.; Shkol'nikov, S.N.; Vetyukov, M.M.

1989-01-01

The results investigating rhenium corrosion in chloride melts containing sodium, potassium and chromium ions by a gravimetry potentials in argon atmosphere in a sealing quarth cell are described. Rhenium corrosion is shown to be rather considerable in melts containing CrCl 2 . The value of corrosion rate depending on temperature is determined

Thiocarbonyl complexes of rhenium. Pt. 1

International Nuclear Information System (INIS)

Abram, U.

1993-01-01

Novel rhenium complexes with terminal thiocarbonyl groups have been synthesized from ReCl 3 (Me 2 PhP) 3 and sodium diethyldithiocarbamate. mer-(Diethyldithiocarbamato)tris-(dimethylphenylphosphine)(thiocarbonyl)rhenium( I), mer-[Re(CS)(Me 2 PhP) 3 (Et 2 dtc)], and tris(diethyldithiocarbamato)(thiocarbonyl)rhenium(III), [Re(CS)(Et 2 dtc) 3 ] have been studied by infrared and NMR spectroscopy, mass spectrometry and X-ray diffraction. mer-[Re(CS)(Me 2 PhP) 3 (Et 2 dtc)] crystallizes orthorhombic in the space group P na 2 1 with a=1516.1(2), b=2189.8(2) and c=1035.6(1) pm. Structure solution and refinement converged at R=0.042. The coordination geometry is a distorted octahedron. The Re-C bond length is found to be 184(2) pm. [Re(CS)(Et 2 dtc) 3 ] crystallizes monoclinic in the space group P2 1 /c with a=962.2(6), b=1744.0(2), c=1537.4(6) pm and β=96.21(1) . The final R value is 0.028. In the monomeric complex the rhenium atom is seven-coordinate with an approximate pentagonal-bipyramidal coordination sphere and a rhenium-carbon distance of 181(1) pm. (orig.)

Near net shape of powder metallurgy rhenium parts

International Nuclear Information System (INIS)

Leonhardt, T.; Downs, J.

2001-01-01

In this paper, a description of the stages of processing necessary to produce a near-net shape (NNS) powder metallurgy (PM) rhenium component through the use of cold isostatic pressing (CIP) to form a complex shape will be explained. This method was primarily developed for the production of the 440 N and 490 N liquid apogee engine combustion chambers used in satellite positioning systems. The CIP to NNS process has been used in the manufacture and production of other rhenium aerospace components as well. Cold isostatic pressing (CIP) to a near net shape utilizing a one or two-part mandrel greatly reduces the quantity of rhenium required to produce the component, and also significantly reduces the number of secondary machining operations necessary to complete the manufacturing process. Further, the developments in near-net shape powder metallurgy rhenium manufacturing techniques have generated significant savings in the area of both time and budget. Overall, cost declined by as much as 35 % for the quantity of rhenium chambers, and manufacturing time was decreased by 30-40 %. The quantity of rhenium metal powder used to produce a rhenium chamber was reduced by approximately 70 %, with a subsequent reduction of nearly 50 % in secondary machining operation schedules. Thus, it is apparent that the overall savings provided by the production of near-net shape powder metallurgy rhenium components will be more than merely another aspect of any project involving high temperature applications, it will constitute significant benefit. (author)

Development of industrial hydrogenating catalyst on rhenium base

International Nuclear Information System (INIS)

Chistyakova, G.A.; Bat', I.I.; Rebrova, V.V.

1975-01-01

Processes for forming rhenium catalysts on carbon carrier and their catalytic properties in nitrobenzene (NB) reduction were studied. Application of an ammonia preparation to the carbon surface produced impregnated carbon saturated at room temperature with a water solution of the ammonia preparation, taken in a volume equal to the volumetric capacity of the carbon. With one impregnation, 2% rhenium was taken up. Catalysts containing more than 5% rhenium were obtained by impregnating the carbon with heating and use of more concentrated solutions. Catalysts made in this way and dried at 100 0 C had the composition Re 2 OH/carbon/. The most active catalysts were those reduced at 200-250 0 C; higher temperatures, up to 300-500 0 C, decreased the activity. Study of the catalytic properties of the rhenium catalysts in a liquid phase reduction of NB showed that the specific activity of rhenium depends only slightly on the content of the active component in the catalyst and is close to the specific activity of palladium and considerably exceeds that of nickel. Study of the effect of the NB concentration and hydrogen pressure on the activity and stability of the 5% rhenium catalyst indicated that with NB concentrations from 50 to 10% the process takes place at an essentially constant rate; the order of the reaction was close to zero with an apparent activation energy of about 7000 cal/mole. At pressures of 15-200 atm the yield with the 5% catalyst was proportional to the hydrogen pressure. A big advantage of the rhenium catalysts in the reduction of NB is their high selectivity. With a higher activity than palladium and nickel catalysts, 5% rhenium catalyst produces a high operating capacity in a wide range of contact charges, which has considerable significance for industrial use in contact apparatus of the column type. Comparison of the costs of rhenium catalysts and granular carbon carrier with those of nickel, platinum, and palladium showed that 5% rhenium catalyst can

Preparation of cyclotron-produced {sup 186}Re and comparison with reactor-produced {sup 186}Re and generator-produced {sup 188}Re for the labeling of bombesin

Energy Technology Data Exchange (ETDEWEB)

Moustapha, Moustapha E. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Ehrhardt, Gary J. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Smith, Charles J. [Department of Radiology, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Research Services, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Szajek, Lawrence P. [Positron Emission Tomography Department, National Institutes of Health, Bethesda, MD 20892-1180 (United States); Eckelman, William C. [Positron Emission Tomography Department, National Institutes of Health, Bethesda, MD 20892-1180 (United States); Jurisson, Silvia S. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States)]. E-mail: jurissons@missouri.edu

2006-01-15

The radioisotopes {sup 186}Re and {sup 188}Re have been extensively investigated for various forms of radiotherapy due to their useful and high-abundance {beta} particle emissions, low-abundance and imageable {gamma}-rays, and chemical resemblance to technetium. In addition, {sup 188}Re is available in no-carrier-added (NCA) form from long lived W-188 generators, whereas {sup 186}Re can be produced in large quantities from reactors, although not in NCA form. However, NCA {sup 186}Re can be produced on a cyclotron by a (p,n) reaction on {sup 186}W. The purpose of this study was to compare labeling of the peptide bombesin with these three forms of rhenium radioisotopes. Cyclotron-produced NCA {sup 186}Re was separated radiochemically from enriched {sup 186}W (96.9%) targets using high-purity methyl ethyl ketone (MEK). The resulting {sup 186}Re-MEK was then loaded onto a small alumina column to separate the resulting NCA {sup 186}Re from any remaining {sup 186}W. The experimental levels of impurities associated with {sup 186}Re at the end of the separation process were found to be 5.7x10{sup -6} Ci of {sup 182}Re (0.57%, t {sub 1/2}=12.7 h) and 1.283x10{sup -5} Ci of {sup 182m}Re (1.28%, t {sub 1/2}=2.67 days). The radionuclidic purity of the separated {sup 186}Re was found to be 99.6%, whereas the chemical identity was determined by reversed phase high-performance liquid chromatography (RP-HPLC) to be perrhenate ({sup 186}ReO{sub 4} {sup -}). Generator-produced {sup 188}ReO{sub 4} {sup -} from a {sup 188}W/{sup 188}Re generator (Oak Ridge National Laboratory) and CA {sup 186}ReO{sub 4} {sup -} produced from a {sup 185}Re(n,{gamma}){sup 186}Re reaction at the University of Missouri Research Reactor (MURR) were used for comparison with the NCA {sup 186}Re in subsequent studies. N{sub 3}S-5-Ava-BBN(7-14)NH{sub 2} conjugates provide flexibility for designing {sup 186,188}Re-labeled conjugates that retain high in vitro and in vivo specificity targeting of GRP receptor

Development of a 186Re-HEDP formulation and radio pharmacokinetics comparison with 153Sm-EDTMP

International Nuclear Information System (INIS)

Bribiesca C, A.I.

1998-01-01

Because of the growing interest in the use of the beta emitters radiopharmaceuticals applied to therapy in different cancer cases, we developed a formulation of 186 Re-HEDP (hydroxy ethylidene diphosphonate) as a pain palliative in osseous metastases. Besides serving like therapeutic agent, together with the 153 Sm-EDTMP (ethylene diamine tetra methylene phosphonate), which has already been synthesized and proved, labels EHDP could be very useful like a diagnostic agent in the pursuit of the illness. The irradiation conditions for Rhenium-186 were established by ORIGIN 2 codes for TRIGA reactors. A pharmaceutical formulation was developed employing a factorial experimental design obtaining a complex with a radiochemical purity over 90 %. The complexes 186 Re-HEDP 153 Sm-EDTMP were intravenous administered in BALB-C mice sacrifying them in several intervals of time in order to determine the cumulated activity in each organ to perform absorbed dose calculation by MIRD methodology (Medical Internal Radiation Dose). Radio pharmacokinetic data demonstrated that both complexes follow a biexponential kinetic of first order behavior. In the case of the 186 Re-HEDP the value of the α constant was 0.2789 and β 0.0006 with an effective dose of 2.56 (mSv)/MBq , while for the complex 153 Sm-EDTMP the values of α to and β were 0.9012 and and 0.616 respectively and the effective dose was 0.262 (mSv)/MBq. In conclusion, radiopharmaceutical 153 Sm-EDTMP, showed a greater bone uptake and a minor effective dose, for which it is a better radiopharmaceutical, respect to with the formulation of 186 Re-HEDP. (Author)

Development of a {sup 186}Re-HEDP formulation and radio pharmacokinetics comparison with {sup 153}Sm-EDTMP; Desarrollo de una formulacion de {sup 186}Re-HEDP y comparacion radiofarmacocinetica con el {sup 153}Sm-EDTMP

Energy Technology Data Exchange (ETDEWEB)

Bribiesca C, A I

1998-12-01

Because of the growing interest in the use of the beta emitters radiopharmaceuticals applied to therapy in different cancer cases, we developed a formulation of {sup 186} Re-HEDP (hydroxy ethylidene diphosphonate) as a pain palliative in osseous metastases. Besides serving like therapeutic agent, together with the {sup 153} Sm-EDTMP (ethylene diamine tetra methylene phosphonate), which has already been synthesized and proved, labels EHDP could be very useful like a diagnostic agent in the pursuit of the illness. The irradiation conditions for Rhenium-186 were established by ORIGIN 2 codes for TRIGA reactors. A pharmaceutical formulation was developed employing a factorial experimental design obtaining a complex with a radiochemical purity over 90 %. The complexes {sup 186} Re-HEDP {sup 153} Sm-EDTMP were intravenous administered in BALB-C mice sacrifying them in several intervals of time in order to determine the cumulated activity in each organ to perform absorbed dose calculation by MIRD methodology (Medical Internal Radiation Dose). Radio pharmacokinetic data demonstrated that both complexes follow a biexponential kinetic of first order behavior. In the case of the {sup 186} Re-HEDP the value of the {alpha} constant was 0.2789 and {beta} 0.0006 with an effective dose of 2.56 (mSv)/MBq , while for the complex {sup 153} Sm-EDTMP the values of {alpha} to and {beta} were 0.9012 and and 0.616 respectively and the effective dose was 0.262 (mSv)/MBq. In conclusion, radiopharmaceutical {sup 153} Sm-EDTMP, showed a greater bone uptake and a minor effective dose, for which it is a better radiopharmaceutical, respect to with the formulation of {sup 186} Re-HEDP. (Author)

First principles calculations of interstitial and lamellar rhenium nitrides

Energy Technology Data Exchange (ETDEWEB)

Soto, G., E-mail: gerardo@cnyn.unam.mx [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)

2012-02-15

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

First principles calculations of interstitial and lamellar rhenium nitrides

International Nuclear Information System (INIS)

Soto, G.; Tiznado, H.; Reyes, A.; Cruz, W. de la

2012-01-01

Highlights: ► The possible structures of rhenium nitride as a function of composition are analyzed. ► The alloying energy is favorable for rhenium nitride in lamellar arrangements. ► The structures produced by magnetron sputtering are metastable variations. ► The structures produced by high-pressure high-temperature are stable configurations. ► 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 3 N and Re 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 within binary nitride chemistry.

Concentration of rhenium from dilute sodium chloride solutions

Directory of Open Access Journals (Sweden)

DRAGOLJUB M. LUKIC

2008-03-01

Full Text Available The conditions for the desorption of rhenium from the anion exchange resin Dowex 1-x8 by HNO3, HCl, H2SO4 and NaOH were determined. The solution (5.0´10-3 mol dm-3 Re in 0.15 mol dm-3 NaCl was passed through a column containing 0.10 g of the resin. The total sorbed amount of rhenium was 0.20 g/g of the resin. It was then eluted by the corresponding eluent in the concentration range up to about 3.0 mol dm-3. The highest elution efficiency and the most favourable elution profile were found with 3.0 mol dm-3 HNO3. Over 77 % of the sorbed rhenium was found in the first 5 ml of the eluate. Practically all the rhenium was recovered with 20 ml of the acid. Under the given experimental conditions, HCl and H2SO4 were less favourable while NaOH was not applicable, due to very low efficiency of rhenium elution.

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

Directory of Open Access Journals (Sweden)

Joseph M. Mannion

2017-01-01

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

Linkable thiocarbamoylbenzamidines as ligands for bioconjugation of Rhenium and Technetium; Kopplungsfaehige Thiocarbamoylbenzamidine als Liganden zur Biokonjugation von Rhenium und Technetium

Energy Technology Data Exchange (ETDEWEB)

Castillo Gomez, Juan Daniel

2015-04-27

Bioconjugation reactions with Rhenium and Technetium are of high importance for the development of novel radiopharmaceuticals for nuclear medicine. In this thesis the possibilities for bioconjugation using linkable Thiocarmbamoylbenzamidines as ligands for the complexation of Rhenium and Technetium were examined.

The kinetics of anodic dissolution of rhenium in aqueous electrolyte solutions

International Nuclear Information System (INIS)

Atanasyants, A.G.; Kornienko, V.A.

1986-01-01

The kinetics of anodic rhenium dissolution was investigated by means of potentiodynamic and potentiostatic polarization curves recorded at temperature from 293 to 333 K in different media (NaOH, KOH, NaCl, NaBr, HCl, H 2 SO 4 ) using the rotating disc technique. It is shown that the kinetics of anodic rhenium dissolution and effective activation energy depend not only on the composition and pH value of the solutions but also on the structure of the dissolving rhenium surface. The investigation of the anodic behaviour of the rhenium monocrystal revealed the existence of anisotropy of the monocrystal electrochemical properties. The experimental results point to an important role of adsorption processes in anodic rhenium dissolution. Rhenium dissolution proceeds with formation of intermediate surface adsorption complexes between the metal and the components of the solution

Thermophysical measurements on solid and liquid rhenium

International Nuclear Information System (INIS)

Pottlacher, G.; Jager, H.; Neger, T.

1986-01-01

A fast resistive heating technique was used to measure such thermophysical data of solid and liquid rhenium as enthalpy, specific heat, thermal volume expansion, and electrical resistivity. The measurements are performed with heating rates of slightly more than 10 9 K s -1 up to states of superheated liquid rhenium (7500 K)

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

Directory of Open Access Journals (Sweden)

Widyastuti

2015-08-01

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.

Determination of rhenium in geologic samples of sandstone-type uranium deposit

International Nuclear Information System (INIS)

Li Yanan; Wang Xiuqin; Yin Jinshuang

1997-01-01

The thiourea colorimetry method suitable for the determination of samples with rhenium content higher than 5 μg/g is described. The method is characterized by many advantages: stability of analytical results, simplicity and cheapness of reagent, and wide range of analysed samples. The catalytic colorimetry is also applied to determine trace rhenium meeting the demand for comprehensive appraisal of prospecting and exploration, recovery and utilization of rhenium. This method can also be applied to analyse rhenium of other samples

Work function of carburized rhenium

International Nuclear Information System (INIS)

Pallmer, P.G. Jr.; Gordon, R.L.; Dresser, M.J.

1980-01-01

Variations of the electronic work function of carburized rhenium foils containing approximately 5 at.% carbon have been observed using the contact potential difference technique. Surface work function was observed to vary between 5.25 and 4.1 eV, with the work function of pure rhenium taken as 5.0 eV. Decrease in work function has been ascribed to the formation of graphitic layers on the surface at temperatures below the temperature of saturated solubility. The high work function surface was observed with all carbon in solution and has been ascribed to the presence of amorphous carbon near the surface

Electrocatalysis of the hydrogen evolution reaction by rhenium oxides electrodeposited by pulsed-current

International Nuclear Information System (INIS)

Vargas-Uscategui, Alejandro; Mosquera, Edgar; Chornik, Boris; Cifuentes, Luis

2015-01-01

Highlights: • Rhenium oxides were produced by means of pulsed current electrodeposition over ITO. • The electrocatalytic behavior of rhenium oxides electrodeposited over ITO was studied. • Electrodeposited rhenium oxides showed electrocatalytic behavior increasing the rate of the hydrogen evolution reaction. • The electrocatalysis behavior was explained considering the relative abundance of Re species on the surface of the electrodeposited material. - Abstract: Rhenium oxides are materials of interest for applications in the catalysis of reactions such as those occurring in fuel cells and photoelectrochemical cells. This research work was devoted to the production of rhenium oxide by means of pulsed current electrodeposition for the electrocatalysis of the hydrogen evolution reaction (HER). Rhenium oxides were electrodeposited over a transparent conductive oxide substrate (Indium Tin-doped Oxide – ITO) in an alkaline aqueous electrolyte. The electrodeposition process allowed the production of rhenium oxides islands (200–600 nm) with the presence of three oxidized rhenium species: Re"I"V associated to ReO_2, Re"V"I associated to ReO_3 and Re"V"I"I associated to H(ReO_4)H_2O. Electrodeposited rhenium oxides showed electrocatalytic behavior over the HER and an increase of one order of magnitude of the exchange current density was observed compared to the reaction taking place on the bare substrate. The electrocatalytic behavior varied with the morphology and relative abundance of oxidized rhenium species in the electrodeposits. Finally, two mechanisms of electrocatalysis were proposed to explain experimental results.

Rhenium: a rare metal critical in modern transportation

Science.gov (United States)

John, David A.

2015-01-01

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.

Liposomes as carriers of the beta-emitters rhenium-186 and rhenium-188 for use in radiotherapy

International Nuclear Information System (INIS)

Haefeli, U.

1989-01-01

The two radioisotopes Re-186 and Re-188 are highly favoured as therapeutic nuclides in nuclear medicine due to their unique radiation characteristics. For application in future (e.g. radiosynoviorthesis of the knee) we have chosen liposomes as biodegradable and non-irriting carriers. They were filled with radioactive Re in therapeutic doses of >370 MBq (10 mCi). 1. Small unilamellar liposomes (SUV's) of an average size of 28 nm were prepared by ultrasonic irradiation. They encapsulated only 0.64% of the perrhenate. 2. Liposomes carrying DTPA-SA in their bilayer (SA=octadecylamine) were produced in order to form a complex with Tc and Re. Technetium was complexed in high yield and the Tc-DTPA-liposome bindings were found to be stable when tested by dialysis. Similar attempts to complex Re were not successful because the amount of Sn(+II) required for the reduction was so high that the liposomes were destroyed. 3. Methylthiosemicarbazide (mts) was coupled covalently to aminomethylpolystyrene. These spheres were used as a very convenient and simple model for testing the labelling-yield and the stability of the Re-mts-complex. 4. Two isomers of the complex ReO(OEt)Cl 2 (PPh 3 ) 2 (Rephos) were characterized. These highly lipid-soluble inactive complexes were irradiated by neutrons and then used to prepare a mixed micelle with egg yolk lecithin and the detergent sodium deoxycholate. Liposomes were produced in a size of 60-80 nm in a very simple way by gelfiltration. Up to 53.5% of the radioactive Rephos was incorporated. Monitoring the stability by dialysis an initial loss of 10-15% and subsequent linear decrease were observed. The daily loss could be reduced to 1.0% by the addition of ascorbic acid. After 8 days, 82% of the initial activity still remained in the vesicles. 5. [ReO 2 (en) 2 ]Cl.2H 2 O and [ReO 2 (1,4,8,11-tetraazaundecane)]Cl were synthesized and characterized. 6. A direct enzymatic method to determine the remaining cholate in liposomes was developed

Effect of rhenium addition on tungsten fuzz formation in helium plasmas

Energy Technology Data Exchange (ETDEWEB)

Khan, Aneeqa, E-mail: aneeqa.khan-3@postgrad.manchester.ac.uk [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)

2016-06-15

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.

Effect of rhenium addition on tungsten fuzz formation in helium plasmas

International Nuclear Information System (INIS)

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

2016-01-01

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.

Determination of rhenium in ores of complex composition by the kinetic method

Energy Technology Data Exchange (ETDEWEB)

Pavlova, L G; Gurkina, T V [Kazakhskij Gosudarstvennyj Univ., Alma-Ata (USSR); Tsentral' naya Lab. Yuzhno-Kazakhstanskogo Geologicheskogo Upravleniya, Alma-Ata (USSR))

1979-09-01

The kinetic rhenium determination method is proposed based on rhenium catalytic effect in the reaction of malachite green with thiourea. The accompanying elements, excluding molybdenum, do not interfere with the rhenium determination at their concentration of up to 0.1 M. The interfering influence of molybdenum can be eliminated by addition of tartaric acid to the solution up to the concentration of 0.1 M. This enables to determine rhenium in presence of 1000-fold quantity of molybdenum. The method is applicable for the analysis of complex copper-zinc sulphide ores.

Method of stably radiolabeling antibodies with technetium and rhenium

International Nuclear Information System (INIS)

Paik, C.H.; Reba, R.C.; Eckelman, W.C.

1987-01-01

A method is described for labeling antibodies or antibody fragments with radionuclides of technetium or rhenium to obtain stable labeling, comprising: reacting a reduced radioisotope of technetium or rhenium with an antibody or antibody fragment, or a diethylenetriaminepentaacetic acid conjugated antibody or antibody fragment, in the presence of free or carrier-bound diethylenetriaminepentaacetic acid (DTPA). The amount of DTPA is sufficient to substantially completely inhibit binding of the reduced technetium or rhenium to nonstable binding sites of the antibody or antibody fragment, or the DTPA-conjugated antibody or antibody fragment. The resultant stably labeled antibody or antibody fragment, or DTPA[conjugated antibody or antibody fragment is recovered

Proton irradiation parameters and chemical separation procedure for the bulk production of high-specific-activity {sup 186g}Re using WO{sub 3} targets

Energy Technology Data Exchange (ETDEWEB)

Fassbender, M.E.; Ballard, B.; Birnbaum, E.R. [Los Alamos National Laboratory, Los Alamos, NM (United States). Chemistry Div.] [and others

2013-08-01

Rhenium-186g (T{sub 1/2} = 89.2 h) is a {beta}{sup -} emitter suitable for therapeutic applications. Current production methods rely on reactor production via {sup 185}Re(n,{gamma}) which results in low specific activities, thereby limiting its use. Production by p,d activation of enriched {sup 186}W results in a {sup 186g}Re product with a higher specific activity, allowing it to be used for targeted therapy with limited receptors. A test target consisting of pressed, sintered {sup nat}WO{sub 3} was proton irradiated at Los Alamos (LANL-IPF) to evaluate product yield and impurities, irradiation parameters and wet chemical Re recovery for proof-of-concept for bulk production of {sup 186g}Re. We demonstrated isolation of {sup 186g}Re in 97% yield from irradiated {sup nat}WO{sub 3} targets within 12 h of end of bombardment (EOB) via an alkaline dissolution followed by anion exchange. The recovery process has potential for automation, and WO{sub 3} can be easily recycled for recurrent irradiations. A {sup 186g}Re batch yield of 42.7 {+-} 2.2 {mu}Ci/{mu}Ah or 439 {+-} 23 MBq/C was obtained after 24 h in an 18.5 {mu}A proton beam. The target entrance energy was determined to be 15.6 MeV. The specific activity of {sup 186g}Re at EOB was measured to be 1.9 kCi (70.3 TBq) mmol{sup -1}, which agrees well with the result of a previous {sup 185,186m}Re co-production EMPIRE and TALYS modeling study assuming similar conditions. Utilizing enriched {sup 186}WO{sub 3}, we anticipate that a proton beam of 250 {mu}A for 24 h will provide batch yields of 256 mCi (9.5 GBq) of {sup 186g}Re at EOB with specific activities even higher than 1.9 kCi (70.3 TBq) mmol{sup -1}, suitable for therapy applications. (orig.)

Determination of rhenium in molybdenite by neutron-activation analysis.

Science.gov (United States)

Terada, K; Yoshimura, Y; Osaki, S; Kiba, T

1967-01-01

A neutron-activation method is described for the determination of rhenium in molybdenite. Radiochemical separation by a carrier technique was carried out very rapidly by means of successive liquid-liquid extraction processes. The recovery of rhenium, which was determined by a spectrophotometric method, was about 93%. About 10 samples could be analysed within 6 hr in parallel runs.

A comparative study of electrochemical and optical properties of rhenium deposited on gold and platinum

Energy Technology Data Exchange (ETDEWEB)

Zerbino, Jorge O.; Castro Luna, Ana M.; Martins, M. E. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina). Inst. de Investigaciones Fisico-Quimicas, Teoricas y Aplicadas (INIFTA)]. E-mail: mmartins@inifta.unlp.edu.ar; Zinola, Carlos F.; Mendez, Eduardo [Universidad de la Republica, Montevideo (Uruguay). Facultad de Ciencias. Lab. de Electroquimica Fundamental

2002-08-01

Rhenium-containing films were grown on gold and platinum after different potentiostatic and potentiodynamic polarizations in the - 0.20 V to 0.70 V range (vs rhe) in aqueous acid perrhenate. Experimental data were obtained using cyclic voltammetry and ellipsometry, from which the thickness and optical indices of the electrodeposited rhenium layer were calculated. Metallic rhenium deposition on gold takes place at potentials within the hydrogen evolution reaction. Rhenium oxide on platinum is formed in the hydrogen adatom potential domain, whereas metallic rhenium is deposited concurrently with the hydrogen adsorption and evolution reactions on the same metal. (author)

A comparative study of electrochemical and optical properties of rhenium deposited on gold and platinum

Directory of Open Access Journals (Sweden)

Zerbino Jorge O.

2002-01-01

Full Text Available Rhenium-containing films were grown on gold and platinum after different potentiostatic and potentiodynamic polarizations in the - 0.20 V to 0.70 V range (vs rhe in aqueous acid perrhenate. Experimental data were obtained using cyclic voltammetry and ellipsometry, from which the thickness and optical indices of the electrodeposited rhenium layer were calculated. Metallic rhenium deposition on gold takes place at potentials within the hydrogen evolution reaction. Rhenium oxide on platinum is formed in the hydrogen adatom potential domain, whereas metallic rhenium is deposited concurrently with the hydrogen adsorption and evolution reactions on the same metal.

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

Science.gov (United States)

Brink, Alice; Helliwell, John R

2017-05-01

Multiple possibilities for the coordination of fac -[Re(CO) 3 (H 2 O) 3 ] + 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 L I absorption edge with a selected X-ray wavelength of 0.9763 Å. At the Cu  K α 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.

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

Directory of Open Access Journals (Sweden)

Alice Brink

2017-05-01

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.

Monoclonal Antibodies Radiolabeling with Rhenium-188 for Radioimmunotherapy

Science.gov (United States)

Martini, Petra; Pasquali, Micol

2017-01-01

Rhenium-188, obtained from an alumina-based tungsten-188/rhenium-188 generator, is actually considered a useful candidate for labeling biomolecules such as antibodies, antibody fragments, peptides, and DNAs for radiotherapy. There is a widespread interest in the availability of labeling procedures that allow obtaining 188Re-labeled radiopharmaceuticals for various therapeutic applications, in particular for the rhenium attachment to tumor-specific monoclonal antibodies (Mo)Abs for immunotherapy. Different approaches have been developed in order to obtain 188Re-radioimmunoconjugates in high radiochemical purity starting from the generator eluted [188Re]ReO4−. The aim of this paper is to provide a short overview on 188Re-labeled (Mo)Abs, focusing in particular on the radiolabeling methods, quality control of radioimmunoconjugates, and their in vitro stability for radioimmunotherapy (RIT), with particular reference to the most important contributions published in literature in this topic. PMID:28951872

Manufacture and properties of molybdenum-rhenium alloys

International Nuclear Information System (INIS)

Fischer, B.; Freund, D.

2001-01-01

It is necessary to measure strength and creep behavior to guarantee the safe and reliable usage of refractory alloys at extremely high temperatures. In the literature there is very little information available about the properties of Mo-Re alloys at temperatures higher than 1000 C. A special test facility has been designed and built for stress-rupture testing at very high temperatures (up to 3000 C) of refractory metals and alloys in inert atmospheres. - The stress-rupture strength as well as the creep behavior of molybdenum-rhenium alloys with rhenium contents between 41 and 51 wt.% have been determined at temperatures ranging from 1200 to 2000 C, and rupture times of up to 10 hours using this facility. Previous measurements of stress-rupture strength and creep behavior of pure rhenium have been compared with the measurement results of Mo-Re alloys. - The discussion of the values measured is based on metallographic test results and scanning electron microscopy (SEM) images of Mo-Re alloy samples after stress-rupture testing. (orig.) [de

Effects of pancreatic intraductal injection of a radioisotope in dogs

International Nuclear Information System (INIS)

Devonec, M.; Faure, J.L.; Blanc-Brunat, N.; Dubernard, J.M.; Traeger, J.

1980-01-01

The effects on exocrine and endocrine pancreatic functions of local irradiation by the intraductal injection of Rhenium 186 were investigated as an alternative to neoprene for exocrine secretion suppression. The results indicate that Rhenium 186 irradiation suppressed exocrine secretion of the pancreas while conserving the endocrine function. Although some edema and fibrosis were observed, the effects were not excessive

Shape coexistence in 186Hg and the decay of 186Tl

International Nuclear Information System (INIS)

Cole, J.D.; Ramayya, A.V.; Hamilton, J.H.; Kawakami, H.; van Nooijen, B.; Nettles, W.G.; Riedinger, L.L.; Turner, F.E.; Bingham, C.R.; Carter, H.K.; Spejewski, E.H.; Mlekodaj, R.L.; Schmidt-Ott, W.D.; Zganjar, E.F.; Sastry, K.S.R.; Avignone, F.T. III; Toth, K.S.; Ijaz, M.A.

1977-01-01

Details of the identification of 186 Tl and its decay to 186 Hg as investigated with an isotope separator are presented. Conversion electrons, γ, γ-γ, and e-γ studies establish two bands in 186 Hg; one built on a near-spherical ground state and one on a more strongly deformed shape with a band head at 522 keV. The levels are discussed in the framework of recent theoretical calculations

Electrodialysis separation of rhenium from silicon

International Nuclear Information System (INIS)

Prasolova, O.D.; Borisova, L.V.; Ermakov, A.N.

1989-01-01

A method of separation of ruthenium from silicon by electrodialysis with heterogenuos ion-exchange membranes is developed. The effeciency of purification of rhenium from silicon depending on the number of dialyzer chambers, temperature and pH value of the dialyzate is studed. It is found that an addditional fourth chamber between the middle and anolytic ones causes the purification coefficient increase 50 times. It is necessary to cool the dialyzate in order to reduce silicon migration into the anolyte and reverse diffusion of perrhenate-ion from the anolyte into the dialyzate. The optimal pH value of diaizate is 5.5-6. The method developed has been used for separating rhenium from industrial solution of lead production with complex composition

Determination of rhenium in molybdenite by X-ray fluorescence: A combined chemical-spectrometric technique.

Science.gov (United States)

Solt, M W; Wahlberg, J S; Myers, A T

1969-01-01

Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 microg of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods.

Determination of rhenium in molybdenite by X-ray fluorescence. A combined chemical-spectrometric technique

Science.gov (United States)

Solt, M.W.; Wahlberg, J.S.; Myers, A.T.

1969-01-01

Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 ??g of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. ?? 1969.

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

Science.gov (United States)

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

2017-08-01

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.

Effect of rhenium addition on tungsten fuzz formation in helium plasmas

NARCIS (Netherlands)

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

2016-01-01

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

Electrodeposition of rhenium-tin nanowires

International Nuclear Information System (INIS)

Naor-Pomerantz, Adi; Eliaz, Noam; Gileadi, Eliezer

2011-01-01

Highlights: → Rhenium-tin nanowires were formed electrochemically, without using a template. → The nanowires consisted of a crystalline-Sn-core/amorphous-Re-shell structure. → The effects of bath composition and operating conditions were investigated. → A mechanism is suggested for the formation of the core/shell structure. → The nanowires may be attractive for a variety of applications. - Abstract: Rhenium (Re) is a refractory metal which exhibits an extraordinary combination of properties. Thus, nanowires and other nanostructures of Re-alloys may possess unique properties resulting from both Re chemistry and the nanometer scale, and become attractive for a variety of applications, such as in catalysis, photovoltaic cells, and microelectronics. Rhenium-tin coatings, consisting of nanowires with a core/shell structure, were electrodeposited on copper substrates under galvanostatic or potentiostatic conditions. The effects of bath composition and operating conditions were investigated, and the chemistry and structure of the coatings were studied by a variety of analytical tools. A Re-content as high as 77 at.% or a Faradaic efficiency as high as 46% were attained. Ranges of Sn-to-Re in the plating bath, applied current density and applied potential, within which the nanowires could be formed, were determined. A mechanism was suggested, according to which Sn nanowires were first grown on top of Sn micro-particles, and then the Sn nanowires reduced the perrhenate chemically, thus forming a core made of crystalline Sn-rich phase, and a shell made of amorphous Re-rich phase. The absence of mutual solubility of Re and Sn may be the driving force for this phase separation.

Neutron activation determination of rhenium in shales shales and molybdenites

International Nuclear Information System (INIS)

Zajtsev, E.I.; Radinovich, B.S.

1977-01-01

Described is the technique for neutron activation determination of rhenium in shales and molybdenites with its radiochemical extraction separation by methyl-ethyl ketone. The sensitivity of the analysis is 5x10 -7 %. Experimental checking of the developed technique in reference to the analysis of shales and molybdenites was carried out. Estimated is the possibility of application of X-ray gamma-spectrometer to instrumental determination of rhenium in molybdenites

Synthesis and study of rhenium (5) complexes with benzimidazole and rubeanic acid

Energy Technology Data Exchange (ETDEWEB)

Basitova, S M; Yurina, R D; Kotegov, K V; Amindzhanov, A A

1986-01-01

Mixed rhenium (5) oxohalide complex compounds with benzimidazole and rubeanic acid are synthesized. Composition of the compounds obtained is established by IR spectroscpy thermal and chemical analyses. It is shown that rhenium (5) chloride compound stability to pyrolysis is rather lower than that of the corresponding bromide derivatives.

Synthesis and study of rhenium (5) complexes with benzimidazole and rubeanic acid

International Nuclear Information System (INIS)

Basitova, S.M.; Yurina, R.D.; Kotegov, K.V.; Amindzhanov, A.A.

1986-01-01

Mixed rhenium (5) oxohalide complex compounds with benzimidazole and rubeanic acid are synthesized. Composition of the compounds obtained is established by IR spectroscpy thermal and chemical analyses. It is shown that rhenium (5) chloride compound stability to pyrolysis is rather lower than that of the corresponding bromide derivatives

{sup 186}Re-maSGS-Z{sub HER2:342}, a potential affibody conjugate for systemic therapy of HER2-expressing tumours

Energy Technology Data Exchange (ETDEWEB)

Orlova, Anna; Tran, Thuy A. [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Ekblad, Torun; Karlstroem, Amelie Eriksson [Royal Institute of Technology, School of Biotechnology, Division of Molecular Biotechnology, Stockholm (Sweden); Tolmachev, Vladimir [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Uppsala University, Division of Nuclear Medicine, Department of Medical Sciences, Uppsala (Sweden)

2010-02-15

Affibody molecules are a novel class of tumour-targeting proteins, which combine small size (7 kDa) and picomolar affinities. The Affibody molecule Z{sub HER2:342} has been suggested for imaging of HER2 expression in order to select patients for trastuzumab therapy. When optimizing chelators for {sup 99m}Tc-labelling, we have found that synthetic Z{sub HER2:342} conjugated with mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) and mercaptoacetyl-glycyl-seryl-glycyl (maGSG) chelators provides relatively low renal uptake of radioactivity and could be suitable for therapy. maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} were labelled with {sup 186}Re and their biodistribution was studied in normal mice. Dosimetric evaluation and tumour targeting to HER2-overexpressed xenografts (SKOV-3) by {sup 186}Re-maGSG-Z{sub HER2:342} were studied. Gluconate-mediated labelling of maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} with {sup 186}Re provided a yield of more than 95% within 60 min. The conjugates were stable and demonstrated specific binding to HER2-expressing SKOV-3 cells. Biodistribution in normal mice demonstrated rapid blood clearance, low accumulation of radioactivity in the kidney and other organs, accumulating free perrhenate. Both {sup 186}Re-maGGG-Z{sub HER2:342} and {sup 186}Re-maGSG-Z{sub HER2:342} demonstrated lower renal uptake than their {sup 99m}Tc-labelled counterparts. {sup 186}Re-maGSG-Z{sub HER2:342} provided the lowest uptake in healthy tissues. Biodistribution of {sup 186}Re-maGSG-Z{sub HER2:342} in nude mice bearing SKOV-3 xenografts showed specific targeting of tumours. Tumour uptake 24 h after injection (5.84{+-}0.54%ID/g) exceeded the concentration in blood by more than 500-fold, and uptake in kidneys by about 8-fold. Preliminary dosimetric evaluation showed that dose-to-tumour should exceed dose-to-kidney by approximately 5-fold. Optimization of chelators improves biodistribution properties of rhenium-labelled small scaffold proteins and enables

Rhenium Mechanical Properties and Joining Technology

Science.gov (United States)

Reed, Brian D.; Biaglow, James A.

1996-01-01

Iridium-coated rhenium (Ir/Re) provides thermal margin for high performance and long life radiation cooled rockets. Two issues that have arisen in the development of flight Ir/Re engines are the sparsity of rhenium (Re) mechanical property data (particularly at high temperatures) required for engineering design, and the inability to directly electron beam weld Re chambers to C103 nozzle skirts. To address these issues, a Re mechanical property database is being established and techniques for creating Re/C103 transition joints are being investigated. This paper discusses the tensile testing results of powder metallurgy Re samples at temperatures from 1370 to 2090 C. Also discussed is the evaluation of Re/C103 transition pieces joined by both, explosive and diffusion bonding. Finally, the evaluation of full size Re transition pieces, joined by inertia welding, as well as explosive and diffusion bonding, is detailed.

Mechanistic Study of Oxygen Atom Transfer Catalyzed by Rhenium Compounds

Energy Technology Data Exchange (ETDEWEB)

Shan, Xiaopeng [Iowa State Univ., Ames, IA (United States)

2003-01-01

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⁺3^- and mechanisms of ligand displacement and oxidation were proposed.

Lymph node scintigraphy with sup(99m)Tc-rhenium colloid

International Nuclear Information System (INIS)

Mitsuhata, Naoki; Suyama, Bunzo; Matsumura, Yosuke; Ohmori, Hiroyuki

1981-01-01

Lymph node scintigraphy with sup(99m)Tc-rhenium colloid in evaluation of nodal involvement by urological malignancy were performed on twelve cases (4 bladder cancer, 3 prostatic cancer, 2 penile cancer and 3 testicular tumor). These cases had been examined the extent of disease on the basis of findings at pedal lymphangiography, urography, computed tomography or laparotomy. sup(99m)Tc-rhenium colloid in a volume of 0.2 ml (2 mCi) was injected into the first interdigital webs of each foot without local anesthesia. In one case of penile cancer radioactive colloid was directly injected into the glans penis and prepuce including tumor area. Our clinical experience reported here reveals that lymph node scintigraphy with sup(99m)Tc-rhenium colloid can provide a useful method of investigating the lymphatic system. This technique is reproducible and can be performed in poor risk patients or pediatric patients readily and safely. (author)

Study of the electrodeposition of rhenium thin films by electrochemical quartz microbalance and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Schrebler, R.; Cury, P.; Suarez, C.; Munoz, E.; Vera, F.; Cordova, R.; Gomez, H.; Ramos-Barrado, J.R.; Leinen, D.; Dalchiele, E.A.

2005-01-01

Rhenium thin films were prepared by electrodeposition from an aqueous solution containing 0.1 M Na 2 SO 4 +H 2 SO 4 , pH 2 in presence of y mM HReO 4 . As substrates polycrystalline gold (y=0.75 mM HReO 4 ) and monocrystalline n-Si(100) (y=40 mM HReO 4 ) were used. The electrochemical growth of rhenium was studied by cyclic voltammetry and electrochemical quartz microbalance on gold electrodes. The results found in the potential region before the hydrogen evolution reaction (her) showed that ReO 3 , ReO 2 and Re 2 O 3 with different hydration grades can be formed. In the potential region where the her is occurring, either on gold or n-Si(100) the electrodeposition of metallic rhenium takes place. On both substrates, rhenium films were formed by electrolysis at constant potential and X-ray photoelectron spectroscopy technique was used to characterise these deposits. It was concluded that the electrodeposited films were of metallic rhenium and only the uppermost atomic layer contained rhenium oxide species

High-temperature extraction of rhenium from sulfuric acid solutions with trialkylamines

International Nuclear Information System (INIS)

Gladyhev, V.P.; Andreeva, N.N.; Kim, E.M.; Kovaleva, S.V.

1985-01-01

This paper attempts to determine the possibility of conducting high-temperature extraction of rhenium from sulfuric acid solutions with trialkylamines (TAA) using higher hydrocarbon-paraffin mixtures as the diluent of the extraction system. Substitution of kerosene by paraffin in the extraction system would permit decreasing the danger of fire and explosions during he extraction process. In extracting rhenium from industrial solutions with a melt of higher paraffins containing TAA and alcohols, the extraction system can be continously heated in heat exchangers through which washing sulfuric acid passes and then goes to the extractor. This permits utilizing the heat and decreases the temperature of the solutions for extraction to the optimum temperatures. Extraction of rhenium with a melt of trioctylamine in paraffin obeys the same mechanisms as high-temperature extraction of ruthenium (IV) by amines in kerosene and aromatic hydrocarbons

21 CFR 186.1557 - Tall oil.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tall oil. 186.1557 Section 186.1557 Food and Drugs... Substances Affirmed as GRAS § 186.1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap... consists mainly of tall oil resin acids and tall oil fatty acids. (b) In accordance with § 186.1(b)(1), the...

Influence of nano-cluster compounds of rhenium drugs on the activity of liver enzymes in a tumor model

Directory of Open Access Journals (Sweden)

J. V. Suponko

2010-06-01

Full Text Available Enzymes’ level in rat’s hepatocytes under Guerin's carcinoma T8 development as well as after injection of rhenium compounds and cis-platin has been studied. It has been determined that the decrease of enzymatic activity to the level of the animals of control group was observed at the simultaneous injection of cis-platin and cluster rhenium compounds in nanoliposomal and water-soluble forms. That confirms possible hepatoprotective properties of the rhenium compounds. It has been shown that hepatoprotective properties of rhenium cluster compounds mostly don’t depend on the form of their injection and are detected regardless of anticancer properties. Rhenium-platinum system with β-alanine ligand in aqueous solution, has been found. Its injection is accompanied by the hepatoprotective effect.

Reductive coupling of carbon monoxide in a rhenium carbonyl complex with pendant Lewis acids.

Science.gov (United States)

Miller, Alexander J M; Labinger, Jay A; Bercaw, John E

2008-09-10

Phosphinoborane ligands impart unique reactivity to a rhenium carbonyl cation relative to simple phosphine complexes. Addition of either triethylborohydride or a platinum hydride (that can be formed from H2) forms a rhenium boroxycarbene. This carbene, which crystallizes as a dimer, disproportionates over a period of days to afford the starting cation and a structurally unprecedented boroxy(boroxymethyl)carbene, in which a new C-C bond has been formed between two reduced CO ligands. This product of C-C bond formation can be independently synthesized by addition of 2 equiv of hydride to the rhenium carbonyl cation.

Use of cluster rhenium substances with alkyl ligands for inhibition of the Guerin carcinoma Growth

Directory of Open Access Journals (Sweden)

O. S. Voronkova

2007-04-01

Full Text Available Quantity and quality of erythrocytes, blood haemoglobin concentration, glucose levels in the erythrocytes and plasma, content of TBA-active products in blood plasma of rats were studied during development of the Guerin carcinoma, introduction of cis-platinum and cluster rhenium substances with organic ligands. It was shown that rhenium substances had essential antioxidant effects and changed the dynamic of tumour growth. The conclusion on perspectiveness of further investigations of rhenium substances with cluster fragment and organic ligands in experiments in vivo with changed redox-status of an organism was drawn.

A study of scandia and rhenium doped tungsten matrix dispenser cathode

Science.gov (United States)

Wang, Jinshu; Li, Lili; Liu, Wei; Wang, Yanchun; Zhao, Lei; Zhou, Meiling

2007-10-01

Scandia and rhenium doped tungsten powders were prepared by solid-liquid doping combined with two-step reduction method. The experimental results show that scandia was distributed evenly on the surface of tungsten particles. The addition of scandia and rhenium could decrease the particle size of doped tungsten, for example, the tungsten powders doped with Sc 2O 3 and Re had the average size of about 50 nm in diameter. By using this kind of powder, scandia and rhenium doped tungsten matrix with the sub-micrometer sized tungsten grains was obtained. This kind of matrix exhibited good anti-bombardment insensitivity at high temperature. The emission property result showed that high space charge limited current densities of more than 60 A/cm 2 at 900 °C could be obtained for this cathode. A Ba-Sc-O multilayer about 100 nm in thickness formed at the surface of cathode after activation led to the high emission property.

Characterization of rhenium compounds obtained by electrochemical synthesis after aging process

Energy Technology Data Exchange (ETDEWEB)

Vargas-Uscategui, Alejandro, E-mail: avargasuscat@ing.uchile.cl [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)

2014-12-15

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.

Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium alloys

International Nuclear Information System (INIS)

Mueller, A.J.; Bianco, R.; Buckman, R.W. Jr.

1999-01-01

Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C

Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

International Nuclear Information System (INIS)

Koeppel, B.J.; Subhash, G.

1999-01-01

The plastic response of two kinds of rhenium processed via powder metallurgy (PM) and chemical vapor deposition (CVD) were investigated under uniaxial compression over a range of strain rates. The PM rhenium, further cold rolled to 50 and 80 pct of the original thickness, was also investigated to assess the influence of cold work on the plastic behavior. A strong basal texture was detected in all the preceding materials as a result of processing and cold work. Both CVD and PM rhenium exhibited an increase in yield strength and flow stress with increasing strain rate. In PM rhenium, cold work resulted in an increase in hardness and yield strength and a decrease in the work hardening rate. The deformed microstructures revealed extensive twinning in CVD rhenium. At large strains, inhomogeneous deformation mode in the form of classical cup and cone fracture was noticed

Nanograined Net-Shaped Fabrication of Rhenium Components by EB-PVD

International Nuclear Information System (INIS)

Singh, Jogender; Wolfe, Douglas E.

2004-01-01

Cost-effective net-shaped forming components have brought considerable interest into DoD, NASA and DoE. Electron beam physical vapor deposition (EB-PVD) offers flexibility in forming net-shaped components with tailored microstructure and chemistry. High purity rhenium (Re) components including rhenium-coated graphite balls, Re- plates and tubes have been successfully manufactured by EB-PVD. EB-PVD Re components exhibited sub-micron and nano-sized grains with high hardness and strength as compared to CVD. It is estimated that the cost of Re components manufactured by EB-PVD would be less than the current CVD and powder-HIP Technologies

Effect of octanols structure on their extraction ability as regards to rhenium(VII) in sulfuric acid solutions

International Nuclear Information System (INIS)

Kasikov, A.G.; Petrova, A.M.

2007-01-01

It is established that extraction ability of octanols as regards to rhenium(VII) and sulfuric acid depends on the structure of alcohol, but if in passage from octanol-1 to octanol-3 as regard to rhenium(VII) it rises, then for H 2 SO 4 it falls. Dependence of the distribution function of rhenium from the concentration of the acid has maximums at 4-7 mol l 1- that the most distinctly it becomes apparent for secondary alcohols. Decreasing the extraction ability of octyl alcohols with the growth of H 2 SO 4 concentration more than 7 mol l 1- is connected with the change of extractant composition and forms of rhenium(VII) being in the solution [ru

Treatment of liver cancer with Rhenium-188 Lipiodol: Colombian experience

International Nuclear Information System (INIS)

Bernal, P.; Osorio, M.; Mendoza, M.; Esguerra, R.; Ucros, G.; Gutierrez, C.; Velez, O.; Cerquera, A.M.; Padhy, A.K.

2002-01-01

Aim:Trans-arterial Radio-conjugate therapy plays an important role in the palliative treatment of inoperable liver cancer. It also helps in reduction of the tumor to an operable state from an inoperable one. As a part of an IAEA sponsored coordinated research project, a new radiopharmaceutical, Rhenium-188 Lipiodol has been developed. The aim of this study was to establish the safety of the radiopharmaceutical and to find out the efficacy of treatment. Materials and Methods: Eight patients suffering from various forms of liver cancer (Hepatocellular carcinoma-4, Metastases from carcinoma of colon-3 and Carcinoid- 1) were treated with Rhenium -188 Lipiodol. Seven out of the eight patients were classified as ECOG- 1 and one as ECOG- 3. Labelling of Rhenium-188 with Lipiodol was carried out according to a protocol developed under the CRP and standardized in our service. Rhenium-188 Lipiodol was administered through the trans-arterial route by either selective (75%) or ultra selective (25%) hepatic arteriography. Administered therapeutic doses ranged between 170 MBq and 4181 MBq. Dosimetric evaluations were made using the IAEA developed dosimetry spreadsheet. All patients were followed up (1-5 months, average = 2 months) after treatment by clinical examination, liver function tests, haematological examinations and CT scans of liver to determine the size of hepatic tumor. Results: Rhenium-188 Lipiodol treatment was well tolerated by all patients. No immediate systemic complications were noted in any of the patients within 72 hrs. following therapy. Only two patients had mild rise in temperature in the immediate post-therapy period, which subsided subsequently. One patient who was classified as Child B and ECOG 3, developed encephalopathy on the seventh day after treatment. He died of hepatic failure. Another one present depressive syndrome, didn't accept food and died Follow-up CT scans in all the surviving (6/8) patients revealed significant reduction of the tumours

21 CFR 186.1555 - Japan wax.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan...

THE SYNTHESIS OF BIOCONJUGATE BASED ON RHENIUM(I CARBONYL COMPLEX FOR VISUALIZATION OF PATHOLOGICAL PROCESS

Directory of Open Access Journals (Sweden)

K. O. Piletska

2017-03-01

Full Text Available Tricarbonyl rhenium(I complexes have a great potential like biomarkers. It is caused their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. Rhenium tricarbonyl complexes fac-[Re(CO3(N^N], where N^N is a ligand with low π* orbitals are excellent candidates as imaging dyes. The method of obtaining potential biomarkers based on tricarbonyl rhenium(I complex with a 4-methyl-2,2’-bipyridine-4’-carboxylate by the addition of biomolecules by peptide synthesis was developed. The new complex [Re(CO3MebpyCOOHBr] was synthesized, composition and structure of which were established by mass spectrometry, IR and NMR spectroscopy. A selective attachment of receptor peptide enkephalin to complex [Re(CO3(MebpyCOOHBr] was performed. The formation of a new compound and its structure has been confirmed by HPLC and mass spectral analysis. The method which has been developed allows to connect various peptides to rhenium(I complex in the solution.

21 CFR 186.1256 - Clay (kaolin).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain...

21 CFR 186.1316 - Formic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and is...

21 CFR 186.1093 - Sulfamic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfamic acid. 186.1093 Section 186.1093 Food and... Substances Affirmed as GRAS § 186.1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble and...

21 CFR 186.1374 - Iron oxides.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron oxides. 186.1374 Section 186.1374 Food and... Substances Affirmed as GRAS § 186.1374 Iron oxides. (a) Iron oxides (oxides of iron, CAS Reg. No. 1332-37-2) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron (III...

Structure and x-ray density of electrochemically deposited rhenium films

International Nuclear Information System (INIS)

Petrovich, V.A.; Fedenkov, A.L.; Shepurev, S.Yu.

1988-01-01

The electrodeposition of rhenium was carried out at a constant cathode-current density and room temperature. The backing was grade KEF-0.02 single-crystal silicon. The absorption coefficient μ of the film was determined for the K α radiation of the copper line. The investigation enabled us to conclude that electrochemically deposited rhenium films can be used as a material for the masking coatings of x-ray patterns, since the absorption coefficients of the x-ray radiation of the resultant films are superior to the similar parameters of traditionally employed materials, and surpass these materials in terms of corrosion resistance and simplicity of production

Determination coefficient distribution rhenium and tungsten using method extraction with solvent methyl ethyl ketone

International Nuclear Information System (INIS)

Riftanio Natapratama Hidayat; Maria Christina Prihatiningsih; Duyeh Setiawan

2015-01-01

Determination of the distribution coefficient (K d ) of the rhenium and tungsten conducted for the purpose of knowing the value of K d of the two elements. K d value determination is applied to the process of separation rhenium-188 from target of tungsten-188 for the purposes purification of radioisotopes that are made to meet the radionuclide and radiochemical purity. The K d value determination using solvent extraction with methyl ethyl ketone (MEK). Prior to the determination of K d values, determined beforehand the optimum conditions of extraction process based on the effect of agitation time, the volume of MEK, and the pH of the solution. Confirmation the results of the extraction was conducted using UV-Vis spectrophotometer with a complexing KSCN under acidic conditions and reductant SnCl 2 . The results showed that the optimum condition extraction process to feed each of 10 ppm is when the agitation for 10 minutes, the volume of MEK in 20 ml, and the pH below 5. Obtained the maximum recovery of rhenium are drawn to the organic phase as much as 9.545 ppm. However, the condition of the extraction process does not affect the migration of tungsten to the organic phase. Then the maximum K d values obtained at 2.7566 rhenium and tungsten maximum K d is 0.0873. Optimum conditions of extraction process can be further tested on radioactive rhenium and tungsten as an alternative to the separation of radioisotopes. (author)

Synthesis, reactivity, and properties of N-fused porphyrin rhenium(I) tricarbonyl complexes.

Science.gov (United States)

Toganoh, Motoki; Ikeda, Shinya; Furuta, Hiroyuki

2007-11-12

The thermal reactions of N-fused tetraarylporphyrins or N-confused tetraarylporphyrins with Re2(CO)10 gave the rhenium(I) tricarbonyl complexes bearing N-fused porphyrinato ligands (4) in moderate to good yields. The rhenium complexes 4 are characterized by mass, IR, 1H, and 13C NMR spectroscopy, and the structures of tetraphenylporphynato complex 4a and its nitro derivative 15 are determined by X-ray single crystal analysis. The rhenium complexes 4 show excellent stability against heat, light, acids, bases, and oxidants. The aromatic substitution reactions of 4 proceed without a loss of the center metal to give the nitro (15), formyl (16), benzoyl (17), and cyano derivatives (19), regioselectively. In the electrochemical measurements for 4, one reversible oxidation wave and two reversible reduction waves are observed. Their redox potentials imply narrow HOMO-LUMO band gaps of 4 and are consistent with their electronic absorption spectra, in which the absorption edges exceed 1000 nm. Theoretical study reveals that the HOMO and LUMO of the rhenium complexes are exclusively composed of the N-fused porphyrin skeleton. Protonation of 4 takes place at the 21-position regioselectively, reflecting the high coefficient of the C21 atom in the HOMO orbital. The skeletal rearrangement reaction from N-confused porphyrin Re(I) complex (8) to N-fused porphyrin Re(I) complex (4) is suggested from the mechanistic study as well as DFT calculations.

L-Reactor 186-basin cleaning alternatives

International Nuclear Information System (INIS)

Turcotte, M.D.S.

1983-01-01

Operation of L Reactor will necessitate annual cleaning of the L Area 186 basins. Alternatives are presented for sediment discharge due to 186-basin cleaning activities as a basis for choosing the optimal cleaning method. Current cleaning activities (i.e. removal of accumulated sediments) for the P, C and K-Area 186 basins result in suspended solids concentrations in the effluent waters above the NPDES limits, requiring an exemption from the NPDES permit for these short-term releases. The objective of mitigating the 186-basin cleaning activities is to decrease the suspended solids concentrations to within permit limits while continuing satisfactory operation of the basins

Active and passive vectorization of technetium99m and 188rhenium radiopharmaceuticals for medical imaging and radiotherapy

International Nuclear Information System (INIS)

Lepareur, N.

2003-11-01

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 186 Re and 188 Re, owing to their ideal properties and their similitude with 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 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 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 188 Re-SSS lipiodol and of its analogue 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)

Extraction of rhenium(VII) by phosphorylated podands

International Nuclear Information System (INIS)

Turanov, A.N.; Karandashev, V.K.; Baulin, V.E.

2006-01-01

Interphase distribution of ReO 4 - between aqueous solutions of H 2 SO 4 and solutions of phosphoryl-containing podands in organic solvents is studied. Stoichiometry of the complexes extracted is determined. Effect of extractant structure and nature of organic solvent on efficiency of rhenium extraction into organic phase is determined [ru

Chromatographic separation of rhenium in alumina-methanol/sulfuric acid system

International Nuclear Information System (INIS)

Oguma, Koichi

1983-01-01

The adsorption behavior of a number of metals on alumina was surveyed in a methanol-(0.005 -- 0.5) M H 2 SO 4 (3 : 1 v/v) developing solvent by thin-layer chromatography. Over the acid concentration range tested, Re(VII) does not favor the alumina phase to any great extent while the most other metals are strongly adsorbed on alumina. These findings allowed to establish a column chromatographic technique for selective separation of rhenium in a methanol-0.05 M H 2 SO 4 (3 : 1 v/v) eluent. The separation technique thus established was applied to molybdenite analysis for rhenium. About 100-mg powdered sample containing ca. 100 ppm rhenium was decomposed with HNO 3 and then evaporated nearly to dryness. The residue was dissolved in NH 4 OH and the excess NH 4 OH was expelled by evaporation to dryness. The residue was dissolved in 2.5-ml 0.5 M H 2 SO 4 and 10-ml water, the insoluble materials filtered off, and the filtrate diluted to exactly 25 ml with water. A 10-ml aliquot of this solution was mixed with 30-ml methanol and the mixture was passed through a column (diameter 15 mm, bed height 30 mm) containing 5 g of alumina. The column was then washed with 20 ml of a methanol-0.05 M H 2 SO 4 (3 : 1 v/v) mixture. Rhenium was recovered from the loaded solution and the subsequent washings, and was determined spectrophotometrically with Methylene Blue as a chromogenic reagent. The values obtained from four samples of molybdenite are in good agreement with those obtained by neutron activation analysis. The relative standard deviation (n = 4; calculated from the range) was between 2.0 and 5.2 %. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Lepareur, N

2003-11-15

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)

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

Energy Technology Data Exchange (ETDEWEB)

Lepareur, N

2003-11-15

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)

12 CFR 18.6 - Signature and attestation.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Signature and attestation. 18.6 Section 18.6 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY DISCLOSURE OF FINANCIAL AND OTHER INFORMATION BY NATIONAL BANKS § 18.6 Signature and attestation. A duly authorized officer of the...

Electrodeposition of rhenium from chloride melts: Electrochemical nature, structure and applied aspects

Directory of Open Access Journals (Sweden)

Vinogradov-Zhabrov O.N.

2003-01-01

Full Text Available Processes involved in the electrodeposition of rhenium from chloride melts have been studied over the temperature interval from 680 to 970 0C at a cathodic current density of 5 to 250 mA/cm2. It has been found that rhenium is deposited in the form of continuous layers. In addition to that the growth of deposits as separate single-crystal needles has also been noticed. Continuous layers had axial growth textures. The crystallographic direction of the textures is due to electrolysis conditions, such as concentration of oxygen-containing impurities, temperature, melt composition and cathodic current density. When the concentration of oxygen-containing impurities in the melt decreased, electrolysis temperature increased, the average radius of the supporting electrolyte cations became smaller, or cathodic current density diminished, the direction of the growth textures was changing as follows: (1010 →(1120 →(101L →(0001 →(0001needles. The microhardness of the deposits in this series is 900 to 250 kg/mm2. The growth of deposits on textured rhenium substrates and single crystals having different orientations, including bent substrates, was studied. It has been found that the epitaxial growth is virtually unlimited in depth if the orientation of the substrate coincides with the growth texture under given conditions. If the substrate orientation deviated from the growth texture, the epitaxial growth was nearly absent. Kinetic parameters were measured using the galvanostatic method. The exchange current density was determined over the interval of (0.01-0.1 A/cm2 depending on the concentration of oxygen-containing impurities, cation composition, type of the surface and its condition. The parameter α⋅Z, which was estimated by two methods, was equal to 2.1-3.1. The diffusion coefficient of rhenium ions has been found to be 2.8 ⋅10 −5 cm2/s at 790 0C and 3.5 ⋅10 −5 cm2/s at 840 0C. Galvanoplastic production of rhenium products, such as

Study of technetium behaviour in radiopharmaceuticals. Characterization of sup(99m)Tc-pyrophosphate, sup(99m)Tc-dimercaptosuccinate, sup(99m)Tc-diethylenetriaminepentaacetate complexes and sup(99m)Tc-colloidal rhenium sulphide

International Nuclear Information System (INIS)

Saccavini, J.-C.

1980-12-01

The chemistry of technetium in extremely dilute solution was approached through the study of three complexing agents and a colloid. By the application of high-performance chromatographic techniques to the analysis of (Tc-pyro), (Tc-DTPA), (Tc-DMSA) complexes it was possible to isolate one or more chelates from a single complexing agent. Addition of pertechnetates to a solution of sodium pyrophosphates and stannous chloride at neutral pH leads to the formation of two complexes, both highly osteotropic. By the use of sup(117m)Sn it was shown that tin employed as reducing agent enters into the composition of one of the two complexes, either of which may be obtained preferentially by varying the (Sn)/(pyro) ratio. With technetium at acid pH (2.5) DMSA gives one or more chelates according to the concentration of the reagents present. DTPA with technetium at neutral pH gives a single complex for which a structure is proposed. The addition of calcium, indispensable for DTPA injection, leads to the appearance of a second bimetallic complex in very much smaller proportions than the first. The size distribution of some colloids was studied by ultrafiltration and permeation on gel. The preparation of colloidal rhenium sulphide and the technetium labelling conditions needed to obtain a very fine colloid were developed. The behaviour of technetium in the presence of colloidal rhenium sulphide and tin pyrophosphate was followed by sup(99m)Tc - sup(186)Re and sup(99m)Tc - sup(117m)Sn double-labelling tests. One reduced technetium fraction associates with the hydrolysed tin, the other follows the rhenium sulphide [fr

21 CFR 186.1551 - Hydrogenated fish oil.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogenated fish oil. 186.1551 Section 186.1551... Listing of Specific Substances Affirmed as GRAS § 186.1551 Hydrogenated fish oil. (a) Hydrogenated fish oil (CAS Reg. No. 91078-95-4) is a class of oils produced by partial hydrogenation of oils expressed...

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

Energy Technology Data Exchange (ETDEWEB)

Nahama, F.

1996-11-30

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)

Development of unified X-ray fluorescent analysis to determine rhenium content in multicomponent oxide compositions

International Nuclear Information System (INIS)

Drobot, D.V.; Belyaev, A.V.; Kutvitskij, V.A.; Rysev, A.P.

1999-01-01

A procedure to prepare rhenium-containing glass-like specimens on the basis of bismuth and boron oxides is proposed. The glasses produced are studied by X-ray fluorescent analysis and routine spectrometric thiocyanate analysis. The results make it possible to determine rhenium in oxide mixtures in the range of its content 0.01 - 10% with S r = 0.03 [ru

A Study on the Trapping Characteristics of Rhenium Oxide Using Ca(OH)_2

International Nuclear Information System (INIS)

Lee, Tae-Kyo; Eun, Hee-Chul; Choi, Jung-Hoon; Lee, Ki-Rak; Han, Seung-Youb; Park, Hwan-Seo

2017-01-01

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)_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_4)_2 and Ca_5Re_2O_1_2. The conversion to Ca_5Re_2O_1_2 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.

Tungsten-rhenium composite tube fabricated by CVD for application in 18000C high thermal efficiency fuel processing furnace

International Nuclear Information System (INIS)

Svedberg, R.C.; Bowen, W.W.; Buckman, R.W. Jr.

1980-04-01

Chemical Vapor Deposit (CVD) rhenium was selected as the muffle material for an 1800 0 C high thermal efficiency fuel processing furnace. The muffle is exposed to high vacuum on the heater/insulation/instrumentation side and to a flowing argon-8 V/0 hydrogen gas mixture at one atmosphere pressure on the load volume side. During operation, the muffle cycles from room temperature to 1800 0 C and back to room temperature once every 24 hours. Operational life is dependent on resistance to thermal fatigue during the high temperature exposure. For a prototypical furnace, the muffle is approximately 13 cm I.D. and 40 cm in length. A small (about one-half size) rhenium closed end tube overcoated with tungsten was used to evaluate the concept. The fabrication and testing of the composite tungsten-rhenium tube and prototypic rhenium muffle is described

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

Directory of Open Access Journals (Sweden)

I. V. Leus

2009-11-01

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.

21 CFR 133.186 - Sap sago cheese.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Sap sago cheese. 133.186 Section 133.186 Food and... Products § 133.186 Sap sago cheese. (a) Description. (1) Sap sago cheese is the food prepared by the... method described in § 133.5. Sap sago cheese is not less than 5 months old. (2) One or more of the dairy...

Determination of rhenium (7) trace amounts by spectrophotometric titration in medium of mixed solvents

International Nuclear Information System (INIS)

Kuznetsov, V.V.; Samorukova, O.L.

1978-01-01

The method has been proposed of determining rhenium (7) microamounts by spectrophotometric titration in the medium water-dimethyl-sulphoxide with the reagent nitrochromazo. The method is based on the formation of ionic pairs K + ReO 4 - in water-organic solvents. The results of rhenium determination are satisfactory in a wide concentration range up to 0.3 mkg in 15 ml which makes the method proposed close in sensitivity to photometric methods and much better in reproducibility

Reductive Coupling of Carbon Monoxide in a Rhenium Carbonyl Complex with Pendant Lewis Acids

OpenAIRE

Miller, Alexander J. M.; Labinger, Jay A.; Bercaw, John E.

2008-01-01

Phosphinoborane ligands impart unique reactivity to a rhenium carbonyl cation relative to simple phosphine complexes. Addition of either triethylborohydride or a platinum hydride (that can be formed from H2) forms a rhenium boroxycarbene. This carbene, which crystallizes as a dimer, disproportionates over a period of days to afford the starting cation and a structurally unprecedented boroxy(boroxymethyl)carbene, in which a new C−C bond has been formed between two reduced CO ligands. This prod...

Tungsten - rhenium alloys wire: overview of thermomechanical processing and properties data

International Nuclear Information System (INIS)

Bryskin, B.

2001-01-01

The scope of this study encompasses the compositional modifications of the tungsten-rhenium dual system (W-3/5 Re up to W-27 Re) as well as some of the tungsten-molybdenum-rhenium ternary system. The alloys of interest are considered with a specific representation of powder metallurgy route based on doped or undoped tungsten vs. vacuum melted materials. This paper constitutes an in-depth review of structural and mechanical properties and systematic compilation of challenges necessary to provide the quality consistency of severely drawn filaments. The issue of thermomechanical processing trends is addressed as an important part of W-Re fabrication technology to achieve further improvement in design properties of rod and wire. (author)

Noncontact surface tension and viscosity measurements of rhenium in the liquid and undercooled states

International Nuclear Information System (INIS)

Ishikawa, Takehiko; Paradis, Paul-Francois; Yoda, Shinichi

2004-01-01

Surface tension and viscosity of liquid rhenium, which have hardly been measured due to the extremely high melting temperature of rhenium, were measured using an electrostatic levitation method combined with the oscillation drop technique. Sample position instability problems caused by the photon pressure of the heating lasers and by sample evaporation were solved by modifying the electrodes design. Good sample stability allowed the measurements of the surface tension and the viscosity over wide temperature ranges including the undercooled states. Over the 2800-3600 K interval, the surface tension of rhenium was measured as σ(T)=2.71x10 3 -0.23(T-T m ), where T m is the melting temperature, 3453 K. At T m , the datum agrees well with the literature values. Similarly, on the same temperature range, the viscosity was determined as η(T)=0.08 exp[1.33x10 5 /(RT)] (mPa s)

Dosimetry for the treatment of cystic craniopharyngioma through radiocolloids with {sup 186} Re; Dosimetria para el tratamiento de craneofaringiomas quisticos mediante radiocoloide con {sup 186} Re

Energy Technology Data Exchange (ETDEWEB)

Rojas, E.L.; Al-dweri, F.M.O.; Lallena, A.M. [Depto. de Fisica Moderna, Universidad de Granada (Spain); Bodineau, C.; Galan, P. [Servicio de Radiofisica Hospitalaria, Hospital Regional Universitario ' Carlos Haya' , 29010 Malaga (Spain)

2003-07-01

The cystic craniopharyngioma (CQ) are histologically benign tumors that can affect important organs, as the hypothalamus or the optic nerve. They are treated introducing, inside the cyst, a radioactive colloid. The wall constitutes the white volume and the dosimetry is usually carried out starting from analytic formulas that only are valid in the case of an homogeneous media, uniform and infinite. In this work it is studied the dosimetry of the CQ by means of Monte Carlo simulation (MC), taking in account the different materials and interfaces that conform them. We present the obtained results for the radionuclide {sup 186} Re. We have used the Monte Carlo code Penelope and we follow 5x10{sup 6} histories in each simulation. We supposed a size of CQ of 1.75 cm of radio and a wall thickness of 1 mm and we have varied the constituent materials of the interior of the cyst and of the wall. The analytic calculations that we carry out show an excellent agreement with the MC results for an unique media (water), as much for the beta radiation as for those originated of the Rhenium disintegration. However, when it takes in account the gel that is introduced in the tumor for the treatment and we vary the constituent material of the wall, we find important differences. Of the analysis of our results we can conclude that the dosimetry for the treatment of CQ based in the usual analytic formulas overestimates the doses really deposited in the wall of the CQ. (Author)

Monte Carlo criticality analysis of simple geometries containing tungsten-rhenium alloys engrained with uranium dioxide and uranium mononitride

International Nuclear Information System (INIS)

Webb, Jonathan A.; Charit, Indrajit

2011-01-01

Highlights: → The addition of rhenium to the tungsten matrix within W-UO 2 and W-UN CERMET materials can help reduce the risk of submersion criticality accidents while increasing the strength and ductility of tungsten based nuclear fuel elements. → The addition of rhenium up to 30 at.% to simple geometries containing W-UO 2 mixtures can increase the critical mass by 65 kg. → The addition of rhenium up to 30 at.% to simple geometries containing W-UN mixtures can increase the critical mass by 22 kg. → The addition of rhenium by up to 30 at.% to simple geometries containing W-UO 2 mixtures can reduce the change in reactivity change due to water submersion by $5.07. → The addition of rhenium by up to 30 at.% to simple geometries containing W-UN mixtures can reduce the change in reactivity due to water submersion by $3.24. - Abstract: The critical mass and dimensions of simple geometries containing highly enriched uranium dioxide (UO 2 ) and uranium mononitride (UN) encapsulated in tungsten-rhenium alloys are determined using MCNP5 criticality calculations. Spheres as well as cylinders with length to radius ratios of 1.82 are computationally built to consist of 60 vol.% fuel and 40 vol.% metal matrix. Within the geometries, the uranium is enriched to 93 wt.% uranium-235 and the rhenium content within the metal alloy was modeled over the range of 0-30 at.%. The spheres containing UO 2 were determined to have a critical radius of 18.29-19.11 cm and a critical mass ranging from 366 kg to 424 kg. The cylinders containing UO 2 were found to have a critical radius ranging from 17.07 cm to 17.84 cm with a corresponding critical mass of 406-471 kg. Spheres engrained with UN were determined to have a critical radius ranging from 14.82 cm to 15.19 cm and a critical mass between 222 kg and 242 kg. Cylinders which were engrained with UN were determined to have a critical radius ranging from 13.81 cm to 14.15 cm and a corresponding critical mass of 245-267 kg. The critical

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

Science.gov (United States)

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

2012-11-20

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.

Effect of rhenium irradiations on the mechanical properties of tungsten for nuclear fusion applications

Energy Technology Data Exchange (ETDEWEB)

Khan, Aneeqa, E-mail: aneeqa.khan-3@postgrad.manchester.ac.uk [School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL (United Kingdom); Elliman, Robert; Corr, Cormac [Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia); Lim, Joven J.H.; Forrest, Andrew [School of Materials, The University of Manchester, M13 9PL (United Kingdom); Mummery, Paul [School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL (United Kingdom); Evans, Llion M. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

2016-08-15

As-received and annealed tungsten samples were irradiated at a temperature of 400 °C with Re and W ions to peak concentrations of 1600 appm (atomic parts per million) and damage levels of 40 dpa (displacements per atom). Mechanical properties were investigated using nanoindentation, and the orientation and depth dependence of irradiation damage was investigated using Electron Back Scatter Diffraction (EBSD). Following irradiation there was a 13% increase in hardness in the as received sheet and a 23% increase in the annealed material for both tungsten and rhenium irradiation. The difference between the tungsten and rhenium irradiated samples was negligible, suggesting that for the concentrations and damage levels employed, the presence of rhenium does not have a significant effect on the hardening mechanism. Energy dependent EBSD of annealed samples provided information about the depth distribution of the radiation damage in individual tungsten grains and confirmed that the radiation damage is orientation dependant.

Biomolecule labelling by 186 Re

International Nuclear Information System (INIS)

Lungu, Valeria Viorica; Mihailescu, Gabriela; Dumitrescu, Gabriela

1998-01-01

The aim of this study is to develop and improve the existing radiolabelling techniques of peptides and monoclonal antibodies with 186 Re and 188 Re as potential agents for cancer targeted radiotherapy. We selected the following methods and techniques for direct labelling of peptides and monoclonal antibody: 1. Prereduction of -S-S- bridges of biomolecule to sulfhydryls using reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The prereduction reactions are controlled by massic ratios of reduction agents/biomolecule, pH, temperature and time of incubation; 2. Reduction of 186 Re O 4 - stannous chloride in acid and alkaline pH; 3. Coupling reaction of 186 Re (red) with the biomolecule controlled by the time and temperature of incubation, the influence of pH regarding the binding of 186 Re to the biomolecules. The quality control was effected by chromatography techniques (paper and elution gel chromatography) on labeled biomolecule before and after purification. The elution gel chromatography was spectrophotometricaly monitored at 280 nm. In the same time the radioactivity of samples was measured using a gamma counter. All the results confirm in vitro stability of labeled biomolecule. The biological evaluation studies regarding accumulation and biological affinity will be controlled by scintigraphy method. Biodistribution studies will be effected to Walker tumor bearing animals at 4 and 24 hours after injections. (authors)

Decoloration studies of some fluorescent dye solutions

International Nuclear Information System (INIS)

Zafar-uz-Zaman, M.; Ditta, A.

1997-01-01

Rhenium-186-(Sn)-l, l hydroxy ethylene diphosphonate (/sup 186/Re-HEDP) has been used for the palliation of metastatic bone pain. /sup 186/Re- has excellent physical properties that may be useful for the formulation of radiotherapeutic agents. It has a short half-life (90.6 hrs) with moderate energy particles (E /sub max/=1.07 MeV) that penetrate over a short range of tissue and gamma ray of 137 keV which is well suited to image. A number of samples of natural rhenium (metal) power were irradiated in PARR-I research reactor at a thermal neutrons flux of the order lx10/sup 14/ n.cm /sup -2/.s/sup -1/ for various time intervals in order to optimize the production yield of /sup 186/Re. The data indicated that 60 mCi/mg of radioactivity could be obtained for an irradiation time of 24 hours. The irradiated target was converted to its ammonium salt which was used for preparation of /sup 186/Re-HEDP complex. Labeling studies of dissolution salt of HEDP with /sup 186/Re were performed by varying the amounts of rhenium, HEDP and Sn. These studies were also carried out at different pH of the solutions. The quality control of /sup 186/Re-HEDP complex was checked by radio chromatographic techniques. These investigations indicated that the complex of optimum yield (approx. 95%) could be obtained by using amounts of Re (0.15 mg), HEDP (10 mg), stannous chloride dihydrate (4mg) and pH range of 4-6. The effect of antioxidant genetic acid was studied on the stability of the complex which was found to be stable up to five days in the presence of 3 mg of genetic acid. The biodistribution studies in rats showed optimum uptake by bone after 2.5 hours. (author)

Submersion criticality safety of tungsten-rhenium urania cermet fuel for space propulsion and power applications

Energy Technology Data Exchange (ETDEWEB)

Craft, A.E., E-mail: aaron.craft@inl.gov [Center for Space Nuclear Research (CSNR), INL, Idaho Falls, ID (United States); O’Brien, R.C., E-mail: Robert.OBrien@inl.gov [Center for Space Nuclear Research (CSNR), INL, Idaho Falls, ID (United States); Howe, S.D., E-mail: Steven.Howe@inl.gov [Center for Space Nuclear Research (CSNR), INL, Idaho Falls, ID (United States); King, J.C., E-mail: kingjc@mines.edu [Nuclear Science and Engineering Program, Metallurgical and Materials Engineering Department, Colorado School of Mines, Golden, CO 80401 (United States)

2014-07-01

Highlights: • Criticality safety studies consider a generic space nuclear reactor in reentry scenarios. • Describes the submersion criticality behavior for a reactor fueled with a tungsten cermet fuel. • Study considers effects of varying fuel content, geometry, and other conditions. - Abstract: Nuclear thermal rockets are the preferred propulsion technology for a manned mission to Mars, and tungsten–uranium oxide cermet fuels could provide significant performance and cost advantages for nuclear thermal rockets. A nuclear reactor intended for use in space must remain subcritical before and during launch, and must remain subcritical in launch abort scenarios where the reactor falls back to Earth and becomes submerged in terrestrial materials (including seawater, wet sand, or dry sand). Submersion increases reflection of neutrons and also thermalizes the neutron spectrum, which typically increases the reactivity of the core. This effect is typically very significant for compact, fast-spectrum reactors. This paper provides a submersion criticality safety analysis for a representative tungsten/uranium oxide fueled reactor with a range of fuel compositions. Each submersion case considers both the rhenium content in the matrix alloy and the uranium oxide volume fraction in the cermet. The inclusion of rhenium significantly improves the submersion criticality safety of the reactor. While increased uranium oxide content increases the reactivity of the core, it does not significantly affect the submersion behavior of the reactor. There is no significant difference in submersion behavior between reactors with rhenium distributed within the cermet matrix and reactors with a rhenium clad in the coolant channels. The combination of the flooding of the coolant channels in submersion scenarios and the presence of a significant amount of spectral shift absorbers (i.e. high rhenium concentration) further decreases reactivity for short reactor cores compared to longer cores.

Separation of tungsten and rhenium on alumina

Directory of Open Access Journals (Sweden)

MILOVAN SM. STOILJKOVIC

2004-09-01

Full Text Available The conditions for the efficient separation of tungsten(VI and rhenium (VII on alumina were established. The distribution coefficients Kd for tungstate and perrhenate anions, as well as the separation factors a (a = KdWO42-/Kd ReO4- were determined using hydrochloric or nitric acid as the aqueous media. A solution of sodium chloride in the pH range 2–6 was also examined. Under all the tested experimental conditions, alumina is a much better adsorbent for tungsten than for rhenium. The obtained results indicated that the best separation of these two elements is achieved when 0.01– 0.1 mol dm-3 HCl or 1.0 mol dm-3 HNO3 are used as the aqueous media. If NaCl is used as the aqueous phase, the best separation is achieved with 0.20 mol dm-3 NaCl, pH 4–6. Under these experimental conditions, the breakthrough and saturation capacities of alumina for tungsten at pH 4 are 17 and 26 mg W/g Al2O3, respectively. With increasing pH, these values decrease. Thus, at pH 6 they are only 4 and 13 mg W/g Al2O3, respectively.

Separation of Rhenium from Lead-Rich Molybdenite Concentrate via Hydrochloric Acid Leaching Followed by Oxidative Roasting

Directory of Open Access Journals (Sweden)

Guanghui Li

2016-11-01

Full Text Available Lead-rich molybdenite is a typical rhenium-bearing molybdenum resource in China, which has not been efficiently utilized due to its high contents of lead and gangue minerals. In this study, hydrochloric acid was used for preliminarily removing lead and calcite from a lead-rich molybdenite concentrate. Oxidative roasting-ammonia leaching was then carried out for separation of rhenium and extraction of molybdenum. The hydrochloric acid leaching experiments revealed that 93.6% Pb and 97.4% Ca were removed when the leaching was performed at 95 °C for 10 min with HCl concentration of 8 wt. % and liquid-solid ratio of 5 (mL/g. The results of direct oxidative roasting indicated that 89.3% rhenium was volatilized from the raw concentrate after roasting at 600 °C for 120 min in air. In contrast, the rhenium volatilization was enhanced distinctly to 98.0% after the acid-leached concentrate (leaching residue was roasted at 550 °C for 100 min. By the subsequent ammonia leaching, 91.5% molybdenum was leached out from the calcine produced from oxidative roasting of the acid-leached concentrate, while only 79.3% Mo was leached from the calcine produced by roasting molybdenite concentrate without pretreatment.

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

Directory of Open Access Journals (Sweden)

Mostafa Hosseinzadeh

2014-06-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

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)

2017-01-15

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.

Dosimetry for the treatment of cystic craniopharyngioma through radiocolloids with 186 Re

International Nuclear Information System (INIS)

Rojas, E.L.; Al-dweri, F.M.O.; Lallena, A.M.; Bodineau, C.; Galan, P.

2003-01-01

The cystic craniopharyngioma (CQ) are histologically benign tumors that can affect important organs, as the hypothalamus or the optic nerve. They are treated introducing, inside the cyst, a radioactive colloid. The wall constitutes the white volume and the dosimetry is usually carried out starting from analytic formulas that only are valid in the case of an homogeneous media, uniform and infinite. In this work it is studied the dosimetry of the CQ by means of Monte Carlo simulation (MC), taking in account the different materials and interfaces that conform them. We present the obtained results for the radionuclide 186 Re. We have used the Monte Carlo code Penelope and we follow 5x10 6 histories in each simulation. We supposed a size of CQ of 1.75 cm of radio and a wall thickness of 1 mm and we have varied the constituent materials of the interior of the cyst and of the wall. The analytic calculations that we carry out show an excellent agreement with the MC results for an unique media (water), as much for the beta radiation as for those originated of the Rhenium disintegration. However, when it takes in account the gel that is introduced in the tumor for the treatment and we vary the constituent material of the wall, we find important differences. Of the analysis of our results we can conclude that the dosimetry for the treatment of CQ based in the usual analytic formulas overestimates the doses really deposited in the wall of the CQ. (Author)

Spectroscopy of 186 Pb with mass identification

International Nuclear Information System (INIS)

Baxter, A.M.; Byrne, A.P.; Australian National Univ., Canberra, ACT; Dracoulis, G.D.; Janssens, R.V.F.; Bearden, I.G.; Henry, R.G.

1993-10-01

Transitions in the very neutron-deficient isotope 186 Pb have been identified in mass-gated, recoil-γ and recoil-γ-γ coincidence data obtained with a Fragment Mass Analyser and Compton-suppressed Ge-detector array. The results of the present work confirm and extend a band of levels tentatively proposed in earlier work done elsewhere, and provide a definitive mass assignment of the observed transitions. The band observed in 186 Pb bears a very close resemblance to the yrast band in the isotones 184 Hg, supporting the view that the 186 Pb band is built upon a prolate structure. 11 refs., 4 figs., 1 tab

sup(99m)Tc-sulfur-rhenium-colloid and 111In-indiumcitrate in the bone marrow scintigraphy

International Nuclear Information System (INIS)

Glaubitt, D.; Haberland, K.; Knoch, K.; Fejer, F.L.; Zachariah, S.; Staedtische Krankenanstalten Krefeld

1975-01-01

Bone marrow scintigraphy using 111 In-Indium-citrate and sup(99m)Tc-sulfur rhenium colloid was compared with each other in 6 male and 3 female patients. Our results in all patients were in favour of 111 In-citrate which caused a better delineation of morphological details than sup(99m)Tc-sulfur rhenium colloid did. In the first days after intravenous administration of 111 In-citrate, radioindium accumulated markedly in the pudendal region, this finding being more distinct in male patients than in female ones. On account of these results a considerable radiation dose has to be assumed in bone marrow scintigraphy using 111 In-citrate as long as the absorbed dose from 111 In has not been estimated under consideration of the radioindium accumulation in the pudendal region. 111 In-citrate should be applied in bone marrow scanning only exceptionally and sup(99m)Tc-sulfur rhenium colloid be preferred in the routine diagnostics of bone marrow. (orig.) [de

Therapeutic applications of Rhenium-188 in nuclear medicine and oncology - Current status and expected future perspectives

International Nuclear Information System (INIS)

Knapp, F. F. Jr.

2005-01-01

Full text: The increasing use of unsealed radioactive targeting agents for cancer treatment requires the routine availability of cost-effective radioisotopes. Rhenium-188 (Re-188; half-life 16.9 hours) is a high-energy beta-emitter (E max 2.12 MeV), readily available no- max carrier-added from the alumina-based tungsten-188 (half-life 69 days)/rhenium-188 generator system. Rhenium-188 also emits a 155 keV (15%) gamma photon, permitting gamma camera imaging for biodistribution and dosimetry evaluation. The versatile chemistry of rhenium allows attachment to a wide variety of targeting molecules for Re-188 applications in nuclear oncology for both palliative metastatic treatment and targeted tumor therapy - radionuclide synovectomy, and coronary restenosis therapy. The long parent half-life and consistent performance provide an indefinite generator shelf-life of several months with high Re-188 elution yields (75-85 %) and consistently low W-188 parent breakthrough ( -6 ). Simple post-elution concentration methods have been developed which provide very high specific volume solution of Re-188 for radiolabeling (> 700 mCi/mL saline/1 Ci generator). Over 60 physician-sponsored clinical trials are currently in progress worldwide with applications in nuclear medicine, nuclear oncology and interventional cardiology. A variety of Re-188-labeled therapeutic radiopharmaceuticals and devices are being developed for clinical trials currently in progress for treatment of both benign and metastatic oncological disorders. Palliation of metastatic bone pain with Re-188-HEDP - prepared from a simple 'kit' - has been demonstrated as a cost-effective alternative to similar agents. Recent studies have in fact demonstrated the enhancement of progression-free interval and survival time by repeated Re-188-HEDP injections to patients with metastatic disease from prostate cancer. The use of the Re-188-labeled antiNCA95 (CD66) antibody in conjunction with external beam irradiation is an

Effect of deformation and annealing on mechanical properties of nickel-rhenium alloys

International Nuclear Information System (INIS)

Mashkova, V.M.

1978-01-01

Studied have been the mechanical properties of nickel-rhenium alloys, depending on the extent of deformation and heat treatment leading to softening. The mechanical properties of the alloys have been estimated by the results of the tensile tests of wire samples. The softening of the alloy at different temperatures is judged about by the variation in hardness. The results of the study indicate that the most abrupt reduction in the hardness of the cold-hardened metal occurs at 900-1,000 deg C and the hold-time of 1 min. Increase in the hold-time at such temperature almost does not reduce the hardness. It is established that in order to soften nickel-rhenium alloys in the process of the cold-deformation at brief annealings in the air the hold-time should not exceed 5 min at 800-900 deg C

Highvalent and organometallic technetium and rhenium compounds

International Nuclear Information System (INIS)

Oehlke, Elisabeth

2010-01-01

Diagnostic methods in nuclear medicine allow a detailed description of morphological organ structures and their function. The beta emitting isotope Tc-99 has optimal physical properties (140 keV gamma rays, half-life 6 h) and is therefore used for radiopharmaceuticals. The thesis is concerned with the search for new technetium complexes and their reproducible production. The (TcO3) core is of main interest. The second part of the thesis deals with organometallic technetium and rhenium complexes with carbonyl ligands and N-heterocyclic carbenes that show stability in aerobic aqueous solutions.

Scale-up of high specific activity {sup 186g}Re production using graphite-encased thick {sup 186}W targets and demonstration of an efficient target recycling process

Energy Technology Data Exchange (ETDEWEB)

Balkin, Ethan R.; Gagnon, Katherine; Dorman, Eric [Washington Univ., Seattle, WA (United States). Dept. of Radiation Oncology; and others

2017-07-01

Production of high specific activity {sup 186g}Re is of interest for development of theranostic radiopharmaceuticals. Previous studies have shown that high specific activity {sup 186g}Re can be obtained by cyclotron irradiation of enriched {sup 186}W via the {sup 186}W(d,2n){sup 186g}Re reaction, but most irradiations were conducted at low beam currents and for short durations. In this investigation, enriched {sup 186}W metal targets were irradiated at high incident deuteron beam currents to demonstrate production rates and contaminants produced when using thick targets. Full-stopping thick targets, as determined using SRIM, were prepared by uniaxial pressing of powdered natural abundance W metal or 96.86% enriched {sup 186}W metal encased between two layers of graphite flakes for target material stabilization. An assessment of structural integrity was made on each target preparation. To assess the performance of graphite-encased thick {sup 186}W metal targets, along with the impact of encasing on the separation chemistry, targets were first irradiated using a 22 MeV deuteron beam for 10 min at 10, 20, and 27 μA, with an estimated nominal deuteron energy of 18.7 MeV on the {sup 186}W target material (after energy degradation correction from top graphite layer). Gamma-ray spectrometry was performed post EOB on all targets to assess production yields and radionuclidic byproducts. The investigation also evaluated a method to recover and recycle enriched target material from a column isolation procedure. Material composition analyses of target materials, pass-through/wash solutions and recycling process isolates were conducted with SEM, FTIR, XRD, EDS and ICP-MS spectrometry. To demonstrate scaled-up production, a graphite-encased {sup 186}W target made from recycled {sup 186}W was irradiated for ∝2 h with 18.7 MeV deuterons at a beam current of 27 μA to provide 0.90 GBq (24.3 mCi) of {sup 186g}Re, decay-corrected to the end of bombardment. ICP-MS analysis of the

31 CFR 103.186 - Special measures against Burma.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Special measures against Burma. 103.186 Section 103.186 Money and Finance: Treasury Regulations Relating to Money and Finance FINANCIAL RECORDKEEPING AND REPORTING OF CURRENCY AND FOREIGN TRANSACTIONS Anti-Money Laundering Programs Law Enforcement...

Study on the application of crown ether for neutron activation analysis of rubidium and rhenium in rock samples

International Nuclear Information System (INIS)

Wang Xiaolin; Fu Yibei; Liu Yinong; Xiong Zonghua; Hao Fanhua

1996-01-01

The extraction behaviour of rubidium and rhenium with 18-crown-6 (18C6) and benzo-15-crown-5 (B15C5) in nitrobenzene from picric acid or potassium hydroxide solution are studied and methods for separation and determination are developed. The molar ratio of 18C6 to Rb and B15C5 to Re in the extracted species is probably 2:1. Rubidium and rhenium in rock samples are satisfactorily determined by neutron activation method

Femtosecond Fluorescence and Intersystem Crossing in Rhenium(I) Carbonyl-Bipyridine Complexes

Czech Academy of Sciences Publication Activity Database

Cannizzo, A.; Blanco-Rodríguez, A. M.; Nahhas, A. E.; Šebera, Jakub; Záliš, Stanislav; Vlček, Antonín; Chergui, M.

2008-01-01

Roč. 130, č. 28 (2008), s. 8967-8974 ISSN 0002-7863 R&D Projects: GA MŠk 1P05OC068 Institutional research plan: CEZ:AV0Z40400503 Keywords : rhenium(I) * carbonyl-bipyridine * intersystem crossing Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.091, year: 2008

Molecular Engineering of Technetium and Rhenium Based Radiopharmaceuticals

International Nuclear Information System (INIS)

Zubieta, J.

2003-01-01

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 2 S 2 and N 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

Rhenium(V) complexing with benzimidazole in acidic media

International Nuclear Information System (INIS)

Zakaeva, R.Sh.; Gagieva, S.Ch.; Kaloev, N.I.; Bukov, N.N.; Panyushkin, V.T.

2003-01-01

Coordination compounds of rhenium(V) with 1H-benzimidazole (L) separated from acid media: (HL) 2 [ReOX 5 ](H 2 O) n and [ReOL x X y (H 2 O) z ](H 2 O) n (HL and L - protonated and deprotonated forms of benzimidazole; X = Cl - , Br - ) were studied by the methods of IR spectroscopy, 1 H NMR spectroscopy and thermal gravimetric analysis. Methods of ligand coordination in the complexes are discussed on the basis of data obtained [ru

Fabrication and use of zircaloy/tantalum-sheathed cladding thermocouples and molybdenum/rhenium-sheathed fuel centerline thermocouples

International Nuclear Information System (INIS)

Wilkins, S.C.; Sepold, L.K.

1985-01-01

The thermocouples described in this report are zircaloy/tantalum-sheathed and molybdenum/rhenium alloy-sheathed instruments intended for fuel rod cladding and fuel centerline temperature measurements, respectively. Both types incorporate beryllium oxide insulation and tungsten/rhenium alloy thermoelements. These thermocouples, operated at temperatures of 2000 0 C and above, were developed for use in the internationally sponsored Severe Fuel Damage test series in the Power Burst Facility. The fabrication steps for both thermocouple types are described in detail. A laser-welding attachment technique for the cladding-type thermocouple is presented, and experience with alternate materials for cladding and fuel therocouples is discussed

Rhenium(V) complexes with sulfur-containing amino acids

International Nuclear Information System (INIS)

Gagieva, S.Ch.; Tautieva, M.A.; Tsaloev, A.T.; Galimov, Yu.B.; Gagieva, L.Ch.; Belyaeva, T.N.

2007-01-01

Rhenium(V) complexes with 2-amino-4-(methylthio)butanoic acid (methionine, Met) and 2-amino-3-sulfopropionic acid (cysteine, Cys) have been synthesized. Depending on the initial reagent ratio, the resulting complexes contain one or two ligand molecules. On heating the compounds with one amino acid molecule, two hydrogen halide molecules are removed at 128-132 deg C to form a molecular complex. The composition, structure, and thermal stability of the complexes have been studied by elemental analysis, conductometry, IR spectroscopy, NMR, and mass spectrometry [ru

Preparation of 186Re complexes of dimercaptosuccinic acid hydroxy ethylidine diphosphonate

International Nuclear Information System (INIS)

Kothari, K.; Pillai, M.R.A.; Unni, P.R.; Mathakar, A.R.; Shimpi, H.H.; Noronha, O.P.D.; Samuel, A.M.

1998-01-01

99m Tc(V)-DMSA and 99m Tc-HEDP are widely used for imaging medullary carcinoma and bone, respectively. 186 Re-HEDP is now well established as a therapeutic radiopharmaceutical for palliation of pain due to bone metastases. It is expected that 186/188 Re(V)-DMSA could find application for treating medullary carcinoma. In the present paper we report the work carried out for the preparation of 186 Re complexes of DMSA and HEDP and their bio-distribution studies in Wistar rats. 186 Re was prepared by irradiation of natural Re metal at a flux of 3x10 13 neutrons/cm 2 /s for seven days and processed after a cooling period of four days. The specific activity of 186 Re formed was ∼35 mCi/mg. Complexes with RC purity >98% could be prepared in both the cases by carefully optimizing the reaction conditions. Bio-distribution studies carried out in rats revealed that pharmacological behaviour of 186 Re(V)-DMSA was similar to that of 99m Tc(V)-DMSA. 186 Re-HEDP showed a bone uptake of ∼ 30% at 3 h post injection which remained almost constant for 48 h. (author)

40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

Science.gov (United States)

2010-07-01

... Trading Program. 96.186 Section 96.186 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual Trading...

Study on the pharmacal of 186,188Re-SZ39

International Nuclear Information System (INIS)

Zu Jianhua; Wu Yuanfang; Dong Mo; Li Huiyuan; ZhangYulong

2000-01-01

The stability, immunocompetence and cytotoxicity in tumor as well as tumor inhibiting rate of 186,188 Re-SZ39 are investigated. The results indicate that 186,188 Re-SZ39 is stable in vivo by imaging and the volume of tumor of nude mice reduced obviously. So 186,188 Re-SZ39 has a strong cytotoxicity effect against glioma cells and is of good prospect as immuno-radiotherapeutic agent

40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

Science.gov (United States)

2010-07-01

... Trading Program. 97.186 Section 97.186 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided...

THERMIONIC EMISSION ENHANCEMENT FROM CESIUM COATED RHENIUM IN ELECTRIC FIELDS

Energy Technology Data Exchange (ETDEWEB)

de Steese, J. G.; Zollweg, R. J.

1963-04-15

The plasma-anode technique was used to observe anomalously high thermionic emission from a rhenium surface with small cesium coverage, where the work function of the composite surface is greater than the ionization potential of cesium. Data suggest that emission enhancement is caused by increased cesium coverage because of cesiumion trapping near the emitter surface under the influence of an ion-rich sheath. (auth)

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

International Nuclear Information System (INIS)

Duffy, Thomas S.; Shen, Guoyin; Heinz, Dion L.; Shu, Jinfu; Ma, Yanzhang; Mao, Ho-Kwang; Hemley, Russell J.; Singh, Anil K.

1999-01-01

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 α, 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 ψ 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 ψ, 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

27 CFR 53.186 - Accounting procedures for like articles.

Science.gov (United States)

2010-04-01

... like articles. 53.186 Section 53.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Accounting procedures for like articles. (a) Identification of manufacturer. In applying section 6416 of the Code and the regulations thereunder, a person who has purchased like articles from various...

Intracellular distribution and stability of a luminescent rhenium(I) tricarbonyl tetrazolato complex using epifluorescence microscopy in conjunction with X-ray fluorescence imaging

International Nuclear Information System (INIS)

Wedding, Jason L.; Harris, Hugh H.; Bader, Christie A.; Plush, Sally E.; Mak, Rachel

2016-01-01

Optical fluorescence microscopy was used in conjunction with X-ray fluorescence microscopy to monitor the stability and intracellular distribution of the luminescent rhenium(I) complex fac-[Re(CO) 3 (phen)L], where phen = 1,10-phenathroline and L = 5-(4-iodophenyl)tetrazolato, in 22Rv1 cells. The rhenium complex showed no signs of ancillary ligand dissociation, a conclusion based on data obtained via X-ray fluorescence imaging aligning iodine and rhenium distributions. A diffuse reticular localisation was detected for the complex, in the nuclear/perinuclear region of cells, by either optical or X-ray fluorescence techniques. Furthermore, X-ray fluorescence also showed that the Re-I complex disrupted the homeostasis of some biologically relevant elements, such as chlorine, potassium and zinc.

Preparation and quality control of 186Re compounds

International Nuclear Information System (INIS)

Noto, M.G.; Amor, R.A.; Caviglia, D.A.; Ratner, M.T.; Schroder, A.M.; Rocco, J.C.; Mancini, A.C.

1987-01-01

The optimal conditions were investigated in order to label the methylendiphosphonate (MDP), hydroxyethylendiphosphonate (HEDP), pyrophosphonate (PYP) and ethylendiaminotetramethylenphosphoric (EDTMP) with 186 Re. The biodistribution of these compounds in experimental animals were studied to determine the most suitable therapeutic agent for its eventual use as pain palliative in patients with bone metastases. The biodistribution assays were performed in Wistar rats, and the 186 Re HEDP was finally chosen. (M.E.L.) [es

Developing the 186 Re radiolabelling procedures of peptides and monoclonal antibodies

International Nuclear Information System (INIS)

Lungu, V.; Mihailescu, G.

1999-01-01

Mono and poli-clonal antibodies are the most recent candidate molecules for the radiopharmaceutical preparation used in radioimmunotherapy and radiodiagnostic. Our study presents results in 186 Re direct labelling of HIgG (Human Immunoglobulin G) poli-clonal antibody. The steps in labelling process are: 1. pre-reduction -S-S- bridges of HIgG molecule with ascorbic acid in pH = 3.5 - 4.5; 2. preparation of the reducing system for 186 ReO 4 - in presence of Sn 2+ ions excess and 3. coupling 186 Re (red) to -SH groups of biomolecules. The specific reactions of each step above are controlled by: incubation time and temperature, pH, molar ratio 186 Re: HIgG. 186 Re-HIgG samples were purified by gel elution chromatography method and the quality control was performed by chromatography techniques. To labelled of HIgG we effected the pre-reduction of -S-S- bridges of biomolecules to sulfhydryls using the following reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The pre-reduction reactions are controlled by mass ratios of reduction agent/biomolecule, pH, temperature and time of incubation. HIgG was the biomolecule used in the pre-reduction reactions. The specific parameters for each systems are presented. The stannous chloride was used as reducing agent in two systems, SnCl 2 : 0.05 N HCl and SnCl 2 : 20 mg/ml citric acid. The coupling reaction of 186 Re (red) with the biomolecule has been controlled by time and incubation temperature and the influence of pH regarding the binding of 186 Re to the biomolecule. 186 Re-HIgG was obtained by: i) incubation at the room temperature, 1 hour time of HIgG in thiol form and 186 Re in reducing form and ii) incubation of HIgG in thiol form, at 37 deg C and 22 hours time, with adding after pre-reduction of SnCl 2 and Na 186 ReO 4 . Quality control was effected by chromatography techniques (paper and gel chromatography) on labelled biomolecule before and after purification. The elution gel chromatography

Effect of the method for rhenium neptasulfide preparation on its catalytic properties in hydrogenation of nitrobenzene and m-nitrobenzoic acid

International Nuclear Information System (INIS)

Pal'chevskaya, T.A.; Bogutskaya, L.V.; Belousov, V.M.

1988-01-01

The effect of conditions of rhenium heptasulfide synthesis by thiosulfate method on its physicochemical and catalytic properties during hydrogenation of nitrobenzene and m-nitrobenzoic acid has been studied. It is shown that the maximum yield of m-aminobenzoic acid can be attained on insoluble sulfide rhenium contacts, containing excessive amount of sulfur (3.5 %). Under certain conditions of catalyst synthesis particles of Re 2 S 7 soluble in dimethylformamide are formed, which possess selectivity towards amine

Studies of technetium chemistry. Pt.8. The regularities of the bond length and configuration of rhenium and technetium complexes in crystals

International Nuclear Information System (INIS)

Liu Guozheng; Liu Boli

1995-01-01

Some bond length regularities in MO 6 , MO-4, MX 5 α and MX 4 αβ moieties of technetium and rhenium compounds are summarized and rationalized by cavity model. The chemical properties of technetium and rhenium are so similar that their corresponding complexes have almost the same configuration and M-X bond lengths when they are in cavity-controlled state. Technetium and Rhenium combine preferably with N, O, F, S, Cl and Br when they are in higher oxidation states (>3), but preferably with P, Se etc. when they are in lower oxidation states ( 4 αβ is approximately constant; (2) the average M-X bond length of MX 6 varies moderately with the oxidation state of M; (3) the bond length of M-X trans to M-α in MX 5 α has a linear relationship with the angle

miR-186 inhibits cell proliferation in multiple myeloma by repressing Jagged1

International Nuclear Information System (INIS)

Liu, Zengyan; Zhang, Guoqiang; Yu, Wenzheng; Gao, Na; Peng, Jun

2016-01-01

MicroRNAs (miRNAs) are small, noncoding ribonucleic acids that regulate gene expression by targeting mRNAs for translational repression and degradation. Accumulating experimental evidence supports a causal role of miRNAs in hematology tumorigenesis. However, the specific functions of miRNAs in the pathogenesis of multiple myeloma (MM) remain to be established. In this study, we demonstrated that miR-186 is commonly downregulated in MM cell lines and patient MM cells. Ectopic expression of miR-186 significantly inhibited cell growth, both in vitro and in vivo, and induced cell cycle G_0/G_1 arrest. Furthermore, miR-186 induced downregulation of Jagged1 protein expression by directly targeting its 3′-untranslated region (3′-UTR). Conversely, overexpression of Jagged1 rescued cells from miR-186-induced growth inhibition. Our collective results clearly indicate that miR-186 functions as a tumor suppressor in MM, supporting its potential as a therapeutic target for the disease. - Highlights: • miR-186 expression is decreased in MM. • miR-186 inhibits MM cell proliferation in vitro and in vivo. • Jagged1 is regulated by miR-186. • Overexpression of Jagged1 reverses the effects of miR-186.

miR-186 inhibits cell proliferation in multiple myeloma by repressing Jagged1

Energy Technology Data Exchange (ETDEWEB)

Liu, Zengyan [Department of Hematology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong 250012 (China); Department of Hematology, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Zhang, Guoqiang [Department of Thyroid and Breast Surgery, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Yu, Wenzheng; Gao, Na [Department of Hematology, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Peng, Jun, E-mail: junpeng885@sina.com [Department of Hematology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong 250012 (China)

2016-01-15

MicroRNAs (miRNAs) are small, noncoding ribonucleic acids that regulate gene expression by targeting mRNAs for translational repression and degradation. Accumulating experimental evidence supports a causal role of miRNAs in hematology tumorigenesis. However, the specific functions of miRNAs in the pathogenesis of multiple myeloma (MM) remain to be established. In this study, we demonstrated that miR-186 is commonly downregulated in MM cell lines and patient MM cells. Ectopic expression of miR-186 significantly inhibited cell growth, both in vitro and in vivo, and induced cell cycle G{sub 0}/G{sub 1} arrest. Furthermore, miR-186 induced downregulation of Jagged1 protein expression by directly targeting its 3′-untranslated region (3′-UTR). Conversely, overexpression of Jagged1 rescued cells from miR-186-induced growth inhibition. Our collective results clearly indicate that miR-186 functions as a tumor suppressor in MM, supporting its potential as a therapeutic target for the disease. - Highlights: • miR-186 expression is decreased in MM. • miR-186 inhibits MM cell proliferation in vitro and in vivo. • Jagged1 is regulated by miR-186. • Overexpression of Jagged1 reverses the effects of miR-186.

Neutron activation determination of rhenium in mineral raw materials of complex composition

International Nuclear Information System (INIS)

Shiryaeva, M.B.; Lyubimova, L.N.; Salmin, Yu.P.; Ryumina, K.N.; Tatarkin, M.A.

1984-01-01

The method of neutron-activation rhenium determination in mineral raw material of complex composition is developed, according to which easily hydrolized elements: scandium, iron, lanthanum, ytterbium, protactinium, hafnium and partially ruthenium and osmium are isolated in the form of hydroxides after smelting of a sample, which has been previously irradiated in nuclear reactor (thermal neutron flux 1.2x10 13 n/cm 2 xs for 22 hr) with sodium peroxide and leaching of the melt by water. To separate Re from other interfering elements extraction of perrhenate-ion by methylethylketone from alkali solution is used. Interfering effect of gold is eliminated by its extraction with TBP 30% solution in toluence or benzene from 1 M HNO 3 . Activity of rhenium preparations, singled out from samples of comparison, is measured, using multichannel γ-spectrometer with Ge(Li)-coaxial detector of high resolution (approximately 2.0-2.2 keV over the line 122 keV 5+ Co). Relative standard deviation in Re content range 5x10 -7 -5x10 -2 % does not exceed 0.3

Liquid kit for preparation of 188rhenium-etidronate

International Nuclear Information System (INIS)

Marczewski, Barbara; Dias, Carla Roberta; Moraes, Vanessa; Osso Junior, Joao Alberto

2005-01-01

The aim of this study was the preparation of a liquid kit for radiolabeling of 188 Re-HEDP (hydroxyethylidene diphosphonate). 188 Re was obtained from alumina based 188 W/ 188 Re generators. This paper reports the efficacy of a cold kit stored for more than two weeks, determined by the dependence of the radiolabeling yields of 188 Re-HEDP on the incubation time, reducing agent concentration, the effects of concentration of ligand, the p H of the reaction and the temperature. The cold kits showed a good stability when carrie-free rhenium-188 was added in the reaction mixture. (author)

Cermets based on rhenium and rare earth element oxides

International Nuclear Information System (INIS)

Varfolomeev, M.B.; Velichko, A.V.; Zajtseva, L.L.; Shishkov, N.V.

1977-01-01

The reduction of perrhenates of rare earth elements and of yttrium by hydrogen and the subsequent sintering have yielded cermets based on rhenium and rare earth element oxides inherent in which are more disperse and homogeneous structures than those of the ''molecular'' rare earth element-Tc cermets. The dispersity of cermets increases in the rare earth elements series from La to Lu. The microhardness of the Re phase in cermets is 490 kgf/mm 2 ; the total microhardness of a cermet is substantially higher

Excitation functions and yields for cyclotron production of radiorhenium via deuteron irradiation. {sup nat}W(d,xn){sup 181,182,(A+B),183,184(m+g),186g}Re nuclear reactions and tests on the production of {sup 186g}Re using enriched {sup 186}W

Energy Technology Data Exchange (ETDEWEB)

Manenti, Simone; Persico, Elisa; Bonardi, Mauro L.; Gini, Luigi; Groppi, Flavia [LASA, Univ. degli Studi di Milano, Segrate (Italy); INFN Milano (Italy); Abbas, Kamel; Holzwarth, Uwe; Simonelli, Federica [Institute for Health and Consumer Protection, IHCP, JRC-Ispra, Ispra (Italy)

2014-10-01

Excitation functions, thin- and thick-target yields for the {sup 181-186g}Re and {sup 187}W radionuclides were measured by the activation stacked-foil technique on natural tungsten foils for deuteron energies up to 18.0 MeV. These cross sections were validated by comparing the experimental results for thick-target yields with those calculated by integration of the thin-target yields. It was found that the maximum {sup 186g}Re content by irradiation of natural tungsten is about 55%, a higher value compared with the one found for proton beam, but not sufficient to use natural tungsten for medical purposes yet. Thus, in order to have a higher specific activity A{sub S} of {sup 186g}Re, the use of enriched {sup 186}W target is necessary. Therefore the irradiation of a thick target of enriched {sup 186}W by accelerated deuterons was studied and the results for the production of {sup 186g}Re were compared with those obtained from the irradiation of the same target by accelerated protons. It was found that the deuteron irradiation is preferable for three reasons: larger yield, less contamination by tantalum radioisotopes and smaller required amount of the target, which simplify the separation of the {sup 186g}Re from the target itself.

Diverse roles of hydrogen in rhenium carbonyl chemistry: hydrides, dihydrogen complexes, and a formyl derivative.

Science.gov (United States)

Li, Nan; Xie, Yaoming; King, R Bruce; Schaefer, Henry F

2010-11-04

Rhenium carbonyl hydride chemistry dates back to the 1959 synthesis of HRe(CO)₅ by Hieber and Braun. The binuclear H₂Re₂(CO)₈ was subsequently synthesized as a stable compound with a central Re₂(μ-H)₂ unit analogous to the B₂(μ-H)₂ unit in diborane. The complete series of HRe(CO)(n) (n = 5, 4, 3) and H₂Re₂(CO)(n) (n = 9, 8, 7, 6) derivatives have now been investigated by density functional theory. In contrast to the corresponding manganese derivatives, all of the triplet rhenium structures are found to lie at relatively high energies compared with the corresponding singlet structures consistent with the higher ligand field splitting of rhenium relative to manganese. The lowest energy HRe(CO)₅ structure is the expected octahedral structure. Low-energy structures for HRe(CO)(n) (n = 4, 3) are singlet structures derived from the octahedral HRe(CO)₅ structure by removal of one or two carbonyl groups. For H₂Re₂(CO)₉ a structure HRe₂(CO)₉(μ-H), with one terminal and one bridging hydrogen atom, lies within 3 kcal/mol of the structure Re₂(CO)₉(η²-H₂), similar to that of Re₂(CO)₁₀. For H₂Re₂(CO)(n) (n = 8, 7, 6) the only low-energy structures are doubly bridged singlet Re₂(μ-H)₂(CO)(n) structures. Higher energy dihydrogen complex structures are also found.

Complexes of technetium, rhenium, and rhodium with sexidentate Schiff-base ligands

International Nuclear Information System (INIS)

Hunter, G.; Kilcullen, N.

1989-01-01

The monocationic technetium (IV) and rhenium (IV) complexes with the sexidentate Schiff-base ligands tris[2-(2'-hydroxybenzylideneethyl)]amine and its substituted derivatives have been prepared and their electrochemical properties studied. The variable-temperature 90.6 MHz 13 C-{ 1 H} n.m.r. spectrum of the rhodium (III) complex of tris[2-(2-hydroxy-5'-isopropylbenzylideneethyl)-amine] has been observed, indicating fluxionality at temperatures above 218 K. (author)

Formation, tidal evolution, and habitability of the Kepler-186 system

International Nuclear Information System (INIS)

Bolmont, Emeline; Raymond, Sean N.; Selsis, Franck; Hersant, Franck; Von Paris, Philip; Quintana, Elisa V.; Barclay, Thomas

2014-01-01

The Kepler-186 system consists of five planets orbiting an early M dwarf. The planets have physical radii of 1.0-1.50 R ⊕ and orbital periods of 4-130 days. The 1.1 R ⊕ Kepler-186f with a period of 130 days is of particular interest. Its insolation of roughly 0.32 S ⊕ places it within the surface liquid water habitable zone (HZ). We present a multifaceted study of the Kepler-186 system, using two sets of parameters which are consistent with the data and also self-consistent. First, we show that the distribution of planet masses can be roughly reproduced if the planets were accreted from a high surface density disk presumably sculpted by an earlier phase of migration. However, our simulations predict the existence of one to two undetected planets between planets e and f. Next, we present a dynamical analysis of the system including the effect of tides. The timescale for tidal evolution is short enough that the four inner planets must have small obliquities and near-synchronous rotation rates. The tidal evolution of Kepler-186f is slow enough that its current spin state depends on a combination of its initial spin state, its dissipation rate, and the stellar age. Finally, we study the habitability of Kepler-186f with a one-dimensional climate model. The planet's surface temperature can be raised above 273 K with 0.5-5 bars of CO 2 , depending on the amount of N 2 present. Kepler-186f represents a case study of an Earth-sized planet in the cooler regions of the HZ of a cool star.

Formation, tidal evolution, and habitability of the Kepler-186 system

Energy Technology Data Exchange (ETDEWEB)

Bolmont, Emeline; Raymond, Sean N.; Selsis, Franck; Hersant, Franck [Univ. Bordeaux, Laboratoire d' Astrophysique de Bordeaux, UMR 5804, F-33270 Floirac (France); Von Paris, Philip [Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Rutherfordstrasse 2, D-12489 Berlin (Germany); Quintana, Elisa V. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Barclay, Thomas, E-mail: bolmont@obs.u-bordeaux1.fr [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2014-09-20

The Kepler-186 system consists of five planets orbiting an early M dwarf. The planets have physical radii of 1.0-1.50 R {sub ⊕} and orbital periods of 4-130 days. The 1.1 R {sub ⊕} Kepler-186f with a period of 130 days is of particular interest. Its insolation of roughly 0.32 S {sub ⊕} places it within the surface liquid water habitable zone (HZ). We present a multifaceted study of the Kepler-186 system, using two sets of parameters which are consistent with the data and also self-consistent. First, we show that the distribution of planet masses can be roughly reproduced if the planets were accreted from a high surface density disk presumably sculpted by an earlier phase of migration. However, our simulations predict the existence of one to two undetected planets between planets e and f. Next, we present a dynamical analysis of the system including the effect of tides. The timescale for tidal evolution is short enough that the four inner planets must have small obliquities and near-synchronous rotation rates. The tidal evolution of Kepler-186f is slow enough that its current spin state depends on a combination of its initial spin state, its dissipation rate, and the stellar age. Finally, we study the habitability of Kepler-186f with a one-dimensional climate model. The planet's surface temperature can be raised above 273 K with 0.5-5 bars of CO{sub 2}, depending on the amount of N{sub 2} present. Kepler-186f represents a case study of an Earth-sized planet in the cooler regions of the HZ of a cool star.

40 CFR 61.186 - Reporting requirements.

Science.gov (United States)

2010-07-01

...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... at least 30 days prior notice of each reference opacity level determination required in § 61.183(a...

Rhenium-catalyzed dehydrogenative olefination of C(sp(3))-H bonds with hypervalent iodine(III) reagents.

Science.gov (United States)

Gu, Haidong; Wang, Congyang

2015-06-07

A dehydrogenative olefination of C(sp(3))-H bonds is disclosed here, by merging rhenium catalysis with an alanine-derived hypervalent iodine(III) reagent. Thus, cyclic and acyclic ethers, toluene derivatives, cycloalkanes, and nitriles are all successfully alkenylated in a regio- and stereoselective manner.

Fisiognomica a Qumran: a proposito di 4Q186

Directory of Open Access Journals (Sweden)

Catastini, Alessandro

2010-06-01

Full Text Available In a previous study, the Author singled out physiognomonic practice by Essenes according to Flavius Josephus’ source in Ant II, 119-161. In this article, the research is extended to the Qumranic manuscript 4Q186, a parchment carrying a text whose content is manifestly physiognomonic. In consequence of a comparison between this text and the so-called Two Spirits Treatise of 1QS, the Author argues that the expression רוח לו, utilised in 4Q186, points out the “typology” of the spirit of the individuals that are considered in this text.

En un estudio previo, el autor había estudiado la práctica fisiognómica de los esenios a partir de la evidencia recogida por Flavio Josefo (Ant II, 119-161. En esta ocasión, la investigación se extiende al manuscrito 4Q186, cuyo texto tiene un contenido claramente fisiognómico. La comparación entre este texto y el denominado Tratado de los Dos Espíritus (1QS, lleva al autor a señalar que la expresión רוח לו utilizada en 4Q186 muestra la «tipología» del espíritu de los individuos de los que trata este texto.

Probing intruder configurations in $^{186, 188}$Pb using Coulomb excitation

CERN Multimedia

Columb excitation measurements to study the shape coexistence, mixing and quadrupole collectivity of the low-lying levels in neutron-deficient $^{188}$Pb nuclei are proposed with a view to extending similar studies to the $^{186}$Pb midshell nucleus. The HIE-ISOLDE beam of $^{186,188}$Pb nuclei will be delivered to MINIBALL+SPEDE set-up for simultaneous in-beam $\\gamma$-ray and conversion electron spectroscopy. The proposed experiment will allow the sign of the quadrupole deformation parameter to be extracted for the two lowest 2$^{+}$ states in $^{188}$Pb. Moreover, the advent of SPEDE will allow probing of the bandhead 0$^{+}$ states via direct measurements of E0 transitions. Beam development is requested to provide pure and instense $^{186}$Pb beam.

New extraction chromatographic material for rhenium separation

International Nuclear Information System (INIS)

Lucanikova, M.; Czech Technical University, Prague; Kucera, J.; Czech Technical University, Prague; Sebesta, F.

2008-01-01

Three types of the extraction chromatographic materials, composed from Aliquat R 336 deposited in the polyacrylonitrile (PAN) beads and prepared by different procedures, were compared for extraction of rhenium. The best properties were exhibited when the solid extractant was prepared by impregnation of the ready-made PAN beads. Solid extractant prepared by direct coagulation of the beads from the suspension of Aliquat R 336 in solution of PAN in nitric acid differs only by lower capacity in dynamic conditions. Material prepared from the PAN solution in dimethylsulfoxide was the worst because Aliquat R 336 was washed out from the beads during coagulation of the polymer and the extraction capacity was low. As it is shown, the first two solid extractants are fully comparable with the commercial TEVA Resin. (author)

Synthesis and physicochemical characterization of rhenium (V) complexes with bisbenzoylthiosemicarbazones

International Nuclear Information System (INIS)

Gagieva, S.Ch.; Gutnova, N.A.; Tsaloev, A.T.; Khubulov, A.B.; Arutyunyants, A.A.; Galimov, Yu.B.

2003-01-01

Rhenium (V) complexing with mono- and bis-benzoylthiosemicarbazones is studied in dependence on hydrohalic acids concentration changes. It is determined that in media with high concentration of hydrohalic acids (6 mol/l HCl, 7 mol/l HBr) in dependence on reaction conditions stable complexes with bi- and tridentate coordination of thiosemicarbazone are formed. In the case of hydrohalic acid concentration decreasing stable binuclear and oxohydroxycomplexes are formed. Composition and structure of the compounds obtained are determined by the methods of element analysis, IR spectroscopy, conductometry. Thermal investigations of the compounds obtained are done [ru

The process development of laser surface modification of commercially pure titanium (Grade 2) with rhenium

Science.gov (United States)

Kobiela, K.; Smolina, I.; Dziedzic, R.; Szymczyk, P.; Kurzynowski, T.; Chlebus, E.

2016-12-01

The paper presents the results of the process development of laser surface modification of commercially pure titanium with rhenium. The criterion of the successful/optimal process is the repetitive geometry of the surface, characterized by predictable and repetitive chemical composition over its entire surface as well as special mechanical properties (hardness and wear resistance). The analysis of surface geometry concluded measurements of laser penetration depth and heat affected zone (HAZ), the width of a single track as well as width of a clad. The diode laser installed on the industrial robot carried out the laser treatment. This solution made possible the continuous supply of powder to the substrate during the process. The aim of an investigation is find out the possibility of improving the tribological characteristics of the surface due to the rhenium alloying. The verification of the surface properties (tribological) concluded geometry measurements, microstructure observation, hardness tests and evaluation of wear resistance.

Effect of S186 for decoporated radiostrontium compared with BADE in rats

International Nuclear Information System (INIS)

Zhang Meizhen; Luo Meichu; Chen Guibao; Liu Shijing; Tong Shungao; Sun Meizhen

1995-01-01

The efficacy of S186 for decorporated radiostrontium compared with BADE in rats was studied. The experimental results showed that administered S186 (in 100∼800 mg/kg) increased the 85+89 Sr excretion in urine and reduced 85+89 Sr retention in body being distinctly superior to that of the equal dose BADE (P<0.05). When administered the dose of S186 that was the half dose of BADE could produce the same effect of BADE for removing radiostrontium

Pox 186: A Nearby Protogalaxy?

Science.gov (United States)

Corbin, Michael

1999-07-01

Blue Compact Dwarf Galaxies {BCDGs} typically consist of clusters of early-type stars embedded in older, evolved stellar populations similar in size and shape to normal dwarf ellipticals. However, deep ground-based CCD images of one faint BCDG, Pox 186, reveal a very compact { 5" diameter} structure with no evidence of an underlying older population. Optical spectroscopy of this object also indicates that a large number of Wolf-Rayet stars are present, which implies that a burst of star formation must have occurred very recently {Pox 186 is a protogalaxy, forming its very first generation of stars. Further investigation of this possibility requires the high angular resolution and ultraviolet spectral coverage that only HST can provide. Using WFPC2, we propose to image the galaxy in the U, V, and I bands, in order to better test for the presence of an underlying evolved population and to reveal any substructure in its star-forming regions. Using STIS, we will obtain low-resolution ultraviolet spectra of the galaxy for combination with ground-based spectra covering the optical through near infrared. This will allow us to determine its spectral energy distribution, metallicity, and dust content, which will in turn constrain its age and star formation history.

POX 186: A Dwarf Galaxy Under Construction?

Science.gov (United States)

Corbin, M. R.; Vacca, W. D.

2000-12-01

We have obtained deep images of the ultracompact ( ~ 3'') blue compact dwarf galaxy POX 186 in the F336W, F555W, and F814W filters of the Planetary Camera of the Hubble Space Telescope. We have additionally obtained a low-resolution near ultraviolet spectrum of the object with STIS and combine this with a ground-based spectrum covering the visible continuum and emission lines. Our images confirm this object to be highly compact, with a maximum projected size of only ~ 240 pc, making it one of the smallest galaxies known. We also confirm that the outer regions of the galaxy consist of an evolved stellar population, ruling out earlier speculations that POX 186 is a protogalaxy. However, the PC images reveal the galaxy to have a highly irregular morphology, with a pronounced tidal arm on its western side. This morphology is strongly suggestive of a recent collision between two smaller components which has in turn triggered the central starburst. The F336W image also shows that the material in this tidal stream is actively star forming. Given the very small ( ~ 100 pc) sizes of the colliding components, POX 186 may be a dwarf galaxy in the early stages of formation, which would be consistent with current ``downsizing'' models of galaxy formation in which the least massive objects are the last to form. This work is supported by NASA and the Space Telescope Science Institute.

Liquid kit for preparation of {sup 188}rhenium-etidronate

Energy Technology Data Exchange (ETDEWEB)

Marczewski, Barbara; Dias, Carla Roberta; Moraes, Vanessa; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Centro de Radiofarmacia]. E-mail: baszot@gmail.com

2005-10-15

The aim of this study was the preparation of a liquid kit for radiolabeling of {sup 188} Re-HEDP (hydroxyethylidene diphosphonate). {sup 188} Re was obtained from alumina based {sup 188} W/{sup 188} Re generators. This paper reports the efficacy of a cold kit stored for more than two weeks, determined by the dependence of the radiolabeling yields of {sup 188} Re-HEDP on the incubation time, reducing agent concentration, the effects of concentration of ligand, the p H of the reaction and the temperature. The cold kits showed a good stability when carrie-free rhenium-188 was added in the reaction mixture. (author)

Kinetics and mechanism of nitrobenzene hydrogenation to phenylhydroxylamine in rhenium thiocomplexes solutions

International Nuclear Information System (INIS)

Korenyako, G.I.; Belousov, V.M.

1985-01-01

A study was made on kinetics of nitrobenzene hydrogenation to phenylhydroxylamine in dimethylformamide solutions of rhenium thiocomplexes. The mechanism of hydrogenation was suggested. Formation of hydride catalyst complex represents the first stage of the process. Kinetic equation derived on the basis of suggested mechanism corresponds satisfactorily with experimental results. Thermodynamic parameters of separate process stages calculated on the basis of equilibrium constant values testify as well to the benefit of suggested mechanism

Formamidine sulfinic acid as reducing agent in technetium-99m rhenium sulfide labelling

Energy Technology Data Exchange (ETDEWEB)

Neves, M; Patricio, L [Laboratorio Nacional de Engenharia e Technologia Industrial, Sacavem (Portugal). Dept. de Radioisotopes; Ferronha, H [Laboratorio Nacional de Investigacao Veterinaria, Lisboa (Portugal)

1989-08-01

Labelling kinetic studies, radiochemical characterization and particle size evaluation of {sup 99m}Tc rhenium sulfide colloid using formamidine sulfinic acid as reducing agent are described. Comparison with the same colloid which makes use of Sn-sodium pyrophosphate complex as reducing agent showed higher labelling yields, simplification of labelling procedure and a longer shelf life when formamidine sulfinic acid was used. (author) 15 refs.; 7 figs.

187Os-186Os and He Isotope Systematics of Iceland Picrites

Science.gov (United States)

Brandon, A. D.; Brandon, A. D.; Graham, D.; Gautason, B.

2001-12-01

Iceland is one of the longest-lived modern plumes, and seismic imaging supports a model where the roots of this plume are at the base of the lower mantle. Hence, Os isotopic data for lavas from this plume are ideal for further testing the role of core-mantle chemical exchange at the site of plume generation in the lower mantle, and for addressing the origin of Os-He isotopic variation in plumes. Recent work has shown that lavas from some plume systems (Hawaii, Noril'sk-Siberia, Gorgona) show coupled enrichments in 186Os/188Os and 187Os/188Os, not observed in upper mantle materials including abyssal peridotites. Picrites from Hawaii display a positive correlation between 186Os/188Os and He isotopes (R/Ra), where range in 186Os/188Os of 0.119834+/-28 to 0.1198475+/-29 and corresponding R/Ra from +7 to +25. These systematics are consistent with a lower mantle source for the radiogenic 186Os signal in the Hawaiian plume. The coupled Os enrichments in these plumes has been attributed to core-mantle chemical exchange, consistent with generation of the Hawaiian plume at the base of the lower mantle in D". Other potentially viable models await additional scrutiny. New He isotope and high precision 186Os/188Os and 187Os/188Os measurements for Iceland picrites show unique systematics compared to Hawaii. These picrites have 187Os/188Os ranging from 0.1297 to 0.1381 and R/Ra of +9 to +18, with generally higher R/Ra correlating with higher 187Os/188Os. Unlike the Hawaiian picrites from Hualalai and Loihi, which have coupled enrichments in 186Os/188Os and 187Os/188Os, the Iceland picrites show no enrichment 186Os/188Os - 0.1198363+/-28 (2s, n=14). Such Os-He isotopic variations require one end-member source that has high R/Ra, coupled with a long term elevated Re/Os and Pt/Os similar to that of the upper mantle. These systematics are inconsistent with either known upper mantle materials or those purported for ancient recycled slabs and may be a previously unidentified component

Use of new tandem cation/anion exchange system with clinical-scale generators provides high specific volume solutions of technetium-99m and rhenium-188

International Nuclear Information System (INIS)

Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Guhlke, S.

1998-01-01

In this paper we describe the first application of our simple and inexpensive post-elution tandem cation/anion exchange column system which is based on generator elution with salts of weak acids such as ammonium acetate instead of saline solution to provide very high specific volume solutions of technetium-99m and rhenium-188 from clinical-scale molybdenum-99/technetium-99m generator prepared from low specific activity (n,y) molybdenum-99, and tungsten-188/rhenium-188 generators, respectively. Initial passage of the bolus through a strong cation exchange cartridge converts the ammonium acetate to acetic acid which is essentially not ionized at the acidic pH, allowing specific subsequent amine-type (QMA SepPak TM ) anion exchange cartridge column trapping of the microscopic levels of the pertechnetate or perrhenate. Subsequent elution of the anion cartridge with a small volume ( 500 mCi/mL) from the alumina-based tungsten-188/rhenium-188 generator. (author)

Combined in-beam electron and γ-ray spectroscopy of 184,186Hg

International Nuclear Information System (INIS)

Scheck, M.; Butler, P. A.; Gaffney, L. P.; Carrol, R. J.; Cox, D.; Joss, D. T.; Herzberg, R.-D.; Page, R. D.; Papadakis, P.; Watkins, H. V.; Bree, N.; Huyse, M.; Van Duppen, P.; Grahn, T.; Greenlees, P. T.; Herzan, A.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.

2011-01-01

By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and γ rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei 184,186 Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of 40 Ar and 148,150 Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in 184,186 Hg. Additional information on the E0 component of the 2 2 + →2 1 + transition in 186 Hg was obtained.

Combined in-beam electron and gamma-ray spectroscopy of (184,186)Hg

CERN Document Server

Scheck, M; Rahkila, P; Butler, P A; Larsen, A C; Sandzelius, M; Scholey, C; Carrol, R J; Papadakis, P; Jakobsson, U; Grahn, T; Joss, D T; Watkins, H V; Juutinen, S; Bree, N; Cox, D; Huyse, M; Uusitalo, J; Leino, M; Ruotsalainen, P; Nieminen, P; Srebrny, J; Van Duppen, P; Herzan, A; Greenlees, P T; Julin, R; Herzberg, R D; Hauschild, K; Pakarinen, J; Page, R D; Peura, P; Gaffney, L P; Kowalczyk, M; Rinta-Antila, S; Saren, J; Lopez-Martens, A; Sorri, J; Ketelhut, S

2011-01-01

By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and gamma rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei (184,186)Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of (40)Ar and (148,150)Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in (184,186)Hg. Additional information on the E0 component of the 2(2)(+) -> 2(1)(+) transition in (186)Hg was obtained.

Thermal decomposition of rhenium (5) complexes with 1,2,4-triazole

International Nuclear Information System (INIS)

Amindzhanov, A.A.; Gagieva, S.Ch.; Kotegov, K.V.

1991-01-01

Processes of thermal decomposition of rhenium (5) complexes with 1,2,4-triazole were studied. Thermolysis products were identified on the basis of data of the element analysis, IR spectra, conductometry and other methods. It is ascertained that at the first stage of thermolysis of hydroxyl-containing monomer complexes removal of water molecules occurs, and at the second one - dimerization process with formation of Re-O-Re group. It is shown that the nature of halide ion practically does not affect the temperature of the start of intensive thermal decomposition of the complexes

The analysis of mechanism of rhenium-coated tools' wear-resistance rising

Directory of Open Access Journals (Sweden)

Daniel Petrosyan

2017-06-01

Full Text Available It is proposed to obtain wear-resistant layers on the hard-alloy materials by thermochemical treatment. In the different field of production – mechanical engineering, metallurgy and military technologies, with machine parts demanding high wearproof and corrosion-proof machinery parts on the surfaces of syntheses of diamonds, with metal surface thermal-diffusion with rhenium, to receive diffusion wearing layers for the first time. A method for thermochemical treatment of hard alloy plates has been investigated, allowing to raise the wear-resistance of cutting and mining tools.

Oxidation of iridium coating on rhenium coated graphite at elevated temperature in stagnated air

International Nuclear Information System (INIS)

Huang, Yongle; Bai, Shuxin; Zhang, Hong; Ye, Yicong

2015-01-01

Highlights: • Continuous and dense Ir coatings were prepared on graphite by electrodepostion. • The purification of the as-prepared Ir coating was higher than about 99.98%. • The Ir/Re/C specimen kept integrity without significant failures after oxidation. • The average oxidation rate of the Ir coating was about 0.219 mg/(cm 2 min). • Penetrating holes at gains boundaries resulted in the failure of the Ir coating. - Abstract: Continuous and dense iridium coatings were prepared on the rhenium coated graphite specimens by electrodeposition. The iridium/rhenium coated graphite (Ir/Re/C) specimens were oxidized at elevated temperatures in stagnated air for 3600 s. The purification of the as-prepared Ir coating was higher than about 99.98% with the main impurity elements Si, Al, Fe and Ru. After oxidation, the Ir/Re/C specimens kept integrity without significant failures and the average oxidation rate was about 0.219 mg/(cm 2 min). Pores were found at the grain boundaries and concentrated to penetrating holes with the growth of Ir grains, which resulted in disastrous failures of the Ir coating

Oxidation of iridium coating on rhenium coated graphite at elevated temperature in stagnated air

Energy Technology Data Exchange (ETDEWEB)

Huang, Yongle; Bai, Shuxin, E-mail: NUDT_MSE_501@163.com; Zhang, Hong; Ye, Yicong

2015-02-15

Highlights: • Continuous and dense Ir coatings were prepared on graphite by electrodepostion. • The purification of the as-prepared Ir coating was higher than about 99.98%. • The Ir/Re/C specimen kept integrity without significant failures after oxidation. • The average oxidation rate of the Ir coating was about 0.219 mg/(cm{sup 2} min). • Penetrating holes at gains boundaries resulted in the failure of the Ir coating. - Abstract: Continuous and dense iridium coatings were prepared on the rhenium coated graphite specimens by electrodeposition. The iridium/rhenium coated graphite (Ir/Re/C) specimens were oxidized at elevated temperatures in stagnated air for 3600 s. The purification of the as-prepared Ir coating was higher than about 99.98% with the main impurity elements Si, Al, Fe and Ru. After oxidation, the Ir/Re/C specimens kept integrity without significant failures and the average oxidation rate was about 0.219 mg/(cm{sup 2} min). Pores were found at the grain boundaries and concentrated to penetrating holes with the growth of Ir grains, which resulted in disastrous failures of the Ir coating.

High-resolution metallic magnetic calorimeters for β-spectroscopy on 187rhenium and position resolved X-ray spectroscopy

International Nuclear Information System (INIS)

Porst, Jan-Patrick

2011-01-01

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 β-endpoint spectroscopy on 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 μs 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 ΔE FWHM <5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

Studies of the structures of rhenium complexes with sulphur-containing amino acids: cysteine and homocysteine

International Nuclear Information System (INIS)

Arkowska, A.; Wojciechowski, W.

1979-01-01

Two rhenium compounds have been synthesized: compound 1 with cysteine HS-CH 2 -CH-NH 2 -COOH and compound 2 with homocysteine HS-CH 2 -CH 2 -CH-NH 2 -COOH. On the basis of spectroscopic measurements (IR, far IR, Raman, VIS and UV spectra) and magnetic susceptibility measurements their probable electronic and molecular structures have been determined. (author)

Use of a new tandem cation/anion exchange system with clinical-scale generators provides high specific volume solutions of technetium-99m and rhenium-188

International Nuclear Information System (INIS)

Knapp, F.R. Jr.; Beets, A.L.; Mirzadeh, S.; Guhlke, S.; Univ. of Bonn

1998-03-01

In this paper the authors describe the first application of a simple and inexpensive post elution tandem cation-anion exchange column system which is based on generator elution with salts of weak acids such as ammonium acetate instead of saline solution to provide very high specific volume solutions of technetium-99m and rhenium-188 from clinical scale molybdenum-99/technetium-99m generator prepared from low specific activity (n,y) molybdenum-99, and tungsten-188/rhenium-188 generators, respectively. Initial passage of the bolus through a strong cation exchange cartridge converts the ammonium acetate to acetic acid which is essentially not ionized at the acidic pH, allowing specific subsequent amine type (QMA SepPak trademark) anion exchange cartridge column trapping of the microscopic levels of the pertechnetate or perrhenate. Subsequent elution of the anion cartridge with a small volume ( 500 mCi/mL) from the alumina-based tungsten-188/rhenium-188 generator

Rhenium (5) and molybdenum (5) complexes with 4',4''(5'')-ditretbutyldibenzo-24-crown-8

International Nuclear Information System (INIS)

Ashurova, N.Kh.; Yakubov, K.G.; Basitova, S.M.; Tashmukhamedova, A.K.; Sajfullina, N.Zh.

1989-01-01

Rhenium and molybdenum complexes in +5 oxidation degree with 4',4''(5'')-ditretbutyldibenzo-24-crown-8 (L) are synthesized with 75-95 % yield. Composition and structure of compounds produced are investigated using element analysis, conductometry, IR spectroscopy, thermogravimetry methods. Oxidation degree of complexer metal is determined. It is ascertained that the compound composition corresponds to the MOLX 3 formula, where M-Re, Mo; X-Cl - , Br -

47 CFR 0.186 - Emergency Relocation Board.

Science.gov (United States)

2010-10-01

..., Defense and Emergency Preparedness Functions § 0.186 Emergency Relocation Board. (a) As specified in the... functions of the Commission. Relocation may be required to accommodate a variety of emergency scenarios... require the evacuation of FCC headquarters with little or no advance notice, but for only a short duration...

Chalcogenhalide cluster rhenium- and molybdenum complexes

International Nuclear Information System (INIS)

Fedin, V.P.; Gubin, S.P.; Mishchenko, A.V.; Fedorov, V.E.

1984-01-01

The interaction of rhenium- and molybdenum chalcogenhalides with n-donor ligands (L) is studied. At heating Re 3 X 2 Hal 5 complexes up to 100 deg in DMSO in the L presence obtained are the complexes of the 1-6 composition Re 3 X 2 Hal 5 -x Lx DMSO (X=Se, Hal=Cl, L=Et 3 N(1); X=Se, Hal=Cl, L=Bipy(2); X=Se, Hal=Br, L=Et 3 N(3); X=Se, Hal=Br, L=Bipy(4); X=Te, Hal=Br, L=Et 3 N(5); X=Te, Hal=Br, L=(Me 2 NCH 2 ) 2 (6). In the course of boiling of Mo 3 S 7 Hal 4 with PPh 3 in MeCN the Mo 3 S 7 Hal 4 2PPh 3 complexes (Hal=Cl(7); Br(8)) are obtained. For 1 through 8 complexes the chemical analysis data and IR spectra are given. For 4 and 8 complexes the molecular mass is measured. A possible method of obtaining molecular trinuclear clusters from polymer clusters is discussed

Convenient synthesis of bis(alkoxy)rhenium(VII) complexes

Energy Technology Data Exchange (ETDEWEB)

Zhu, Z.; Al-Ajlouni, A.M.; Espenson, J.H. [Iowa State Univ., Ames, IA (United States)

1996-02-28

The study of high-oxidation-state organorhenium compounds has been a field of continuing activity, thanks to the success of methylrhenium trioxide (CH{sub 3}ReO{sub 3} or MTO) in catalytic processes. This catalyst is effective in oxidations, olefin metathesis, the olefination of aldehydes, and the preparation of other compounds with three-membered rings. The syntheses of some rhenium compounds derived form MTO have been reported. Epoxide formation is a key reaction, and it bears directly on these findings reported here. Re(VII) complexes containing a chelated bis(diolate) ligand can be synthesized by refluxing MTO with 2,3-dimethyl-2,3-diol. Here, the authors report a more convenient method for this preparation. A different series of related compounds consists of chelated bis(diolates) of the Cp*Re-oxo series, Cp*ReO-(diolate).

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

Energy Technology Data Exchange (ETDEWEB)

Porst, Jan-Patrick

2011-02-01

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.)

RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

Energy Technology Data Exchange (ETDEWEB)

AA KRUGER; A GOEL; CP RODRIGUEZ; JS MCCLOY; MJ SCHWEIGER; WW LUKENS; JR, BJ RILEY; D KIM; M LIEZERS; P HRMA

2012-08-13

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.

Chromatographic 188W →188Re generator

International Nuclear Information System (INIS)

Khujaev, S.

2005-01-01

Full text: The main purpose of the generator - reception of daughter radioisotope Rhenium-188 from it by periodic elution for a long period of time (more than half-year). It is generally known that Rhenium-188, in the form of its complex connections, is applied in nuclear medicine in treatment and removal of painful syndromes. The generator possesses convenient nuclear-physical characteristics of a daughter radioisotope Rhenium-188. It is a source of (Irradiation with energy 2.12 MeV (98 %) with small contribution soft γ-radiation with energy 0.155 MeV (15 %). The Period of half-life destruction of radioisotope is 17 hours. The 188 W parent radioisotope for the generator is formed by irradiation of 186 W neutrons based on the following reaction: 186 W (n,γ) 187 W (n,γ) 188 W (69 days) → 188 Re (17 hours) + β The following were used as targets for irradiation: 1) Metal Tungsten (powder) of natural structure; 2) Metal Tungsten (plate) of natural structure; 3) Metal Tungsten (wire) of natural structure, d = 12 mm; 4) Metal Tungsten (powder) with enrichment on isotope 186 W - 99.79 %. The irradiated material was exposed to chemical processing with reception of radioactive solution of tungsten-188, from which sorption Tungsten was carried out onto sorbent as poly-wolframate-ions. It is established that Tungsten sorption depends on many factors as there are various chemical forms of Tungsten (VI) in water solutions, ratio of which depends on pH of the solution, concentration of Tungsten in the solution and presence of foreign ions. Tungsten sorption was carried out in static and in dynamic regimes. At dynamic regime the sorbent was placed directly in the generating column. The generator consisted of chromatographic columns with sorbent and radioisotope 188 W, eluting system and radiation protection. Rhenium-188 was taken from the generator as perrhenate sodium by elution of 0.9 % solution of chloride sodium in 10 ml. Technical characteristics of the generator

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

Science.gov (United States)

Halpern, Jeffrey M; Martin, Heidi B

2014-02-01

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.

Comment: 186 [Taxonomy Icon

Lifescience Database Archive (English)

Full Text Available keru Nakazato (Database Center for Life Science) アゲハチョウ（ナミアゲハ） Papilio xuthus 標本風の写真もあるかと思うので探してみます。 （もしくは撮り直す） nakazato 2008/12/22 09:47:51 2010/01/14 19:54:38 ... ...Asian Swallowtail Papilio xuthus Papilio_xuthus_L.png 186.png Takeru Nakazato (Database Center for Life Scie...nce) licensed under CC Attribution2.1 Japan 撮影:仲里猛留（ライフサイエンス統合データベースセンター） Photo: Ta

Influence of S186 on trace elements in organs of dogs

International Nuclear Information System (INIS)

Luo Meichu; Li Landi; Chen Guibao; Zhang Meizhen

1993-01-01

The authors report the influence of a radiostrontium de-cooperating agents, S186 (calcium sodium N-acetylproplysmine 1, 1-diphosphonate), on trace elements in internal organs of dogs. The trace elements contents were determined with a PE-3030 atomic absorption spectrophotometer. Compared with the control group, the trace elements (Cu, Zn and Mn) contents and the Cu/Zn ratio in organs of Beagle dogs after intramuscular injection of S186 for 30 days did not change obviously except the Cu content in the liver increased

Epitaxial growth of rhenium with sputtering

Energy Technology Data Exchange (ETDEWEB)

Oh, Seongshik [National Institute of Standards and Technology, Boulder, CO 80305 (United States) and Department of Physics, University of Illinois, Urbana, IL 61801 (United States)]. E-mail: soh@boulder.nist.gov; Hite, Dustin A. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Cicak, K. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Osborn, Kevin D. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Simmonds, Raymond W. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); McDermott, Robert [University of California, Santa Barbara, CA 93106 (United States); Cooper, Ken B. [University of California, Santa Barbara, CA 93106 (United States); Steffen, Matthias [University of California, Santa Barbara, CA 93106 (United States); Martinis, John M. [University of California, Santa Barbara, CA 93106 (United States); Pappas, David P. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

2006-02-21

We have grown epitaxial Rhenium (Re) (0001) films on {alpha}-Al{sub 2}O{sub 3} (0001) substrates using sputter deposition in an ultra high vacuum system. We find that better epitaxy is achieved with DC rather than with RF sputtering. With DC sputtering, epitaxy is obtained with the substrate temperatures above 700 deg. C and deposition rates below 0.1 nm/s. The epitaxial Re films are typically composed of terraced hexagonal islands with screw dislocations, and island size gets larger with high temperature post-deposition annealing. The growth starts in a three dimensional mode but transforms into two dimensional mode as the film gets thicker. With a thin ({approx}2 nm) seed layer deposited at room temperature and annealed at a high temperature, the initial three dimensional growth can be suppressed. This results in larger islands when a thick film is grown at 850 deg. C on the seed layer. We also find that when a room temperature deposited Re film is annealed to higher temperatures, epitaxial features start to show up above {approx}600 deg. C, but the film tends to be disordered.

Alkene-glycol interconversion with technetium and rhenium oxo complexes

International Nuclear Information System (INIS)

Pearlstein, R.M.; Davison, Alan

1988-01-01

The trioxotechnetium(VII) complexes TcO 3 Cl(AA) (AA = phen, bpy, 5-NO 2 -phen, 3,4,7,8-Me 4 -phen) cleanly oxidize olefins (C 2 R 4 ) in solution at 22 0 C, forming in high yields the corresponding oxotechnetium(V) diolate complexes, TcOCl(OCR 2 CR 2 O)(AA). The complexes have been characterized by 1 H NMR, IR, elemental analysis, and fast atom bombardment mass spectrometry. The free diols isolated by hydrolysis of these diolate complexes with HCl were shown by capillary gas chromatography to represent syn addition of the two hydroxyl groups across the double bond. The related rhenium complex, ReOCl(OCH 2 CH 2 O)(phen) undergoes the reverse reaction when thermalized, releasing ethylene and producing ReO 3 Cl(phen). (author)

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

Science.gov (United States)

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

2016-08-01

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). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of sedimentation of tungsten on copper substrate for production of {sup 186g}Re via {sup 186}W(p,n) nuclear reaction: Feasibility of using high current, long irradiation

Energy Technology Data Exchange (ETDEWEB)

Kakavand, T., E-mail: Tayeb@znu.ac.ir [Department of Physics, Faculty of Science, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Mirzaii, M.; Khaleghi, M. [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, AEOI, Karaj (Iran, Islamic Republic of); Eslami, M. [Department of Physics, Faculty of Science, University of Zanjan, Zanjan (Iran, Islamic Republic of)

2016-01-01

Highlights: • Optimization of tungsten sedimentation for bulk production of {sup 186}Re. • Influence of targetry parameters on stress-bearing of the target during proton irradiation. • Activity measurement for {sup 186}Re produced via {sup nat}W(p,xn) reaction. - Abstract: Tungsten is recognized as one of the important metals used in cyclotron targets for production of several vital radioisotopes. Adequate adhesion of the prepared targets to its substrate is a significant parameter that makes them optimized for high current beam collisions. The target morphology should be paid special attention as another important parameter. In this work, a rather thick layer of tungsten is deposited on a copper substrate by sedimentation technique to produce {sup 186g}Re radionuclide via {sup 186}W(p,n) reaction. Consecutive sedimentation experiments are carried out to determine the best suspension solution. The prepared targets are evaluated in morphology by scanning electron microscope. A mixture of 1 g tungsten powder, 250 mg ethyl cellulose and 5 mL acetone is concluded for desirable target adhesion. Irradiation of the targets by 20 μA proton current (15 MeV energy) for 5 h shows that they can withstand the proton beam.

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

Science.gov (United States)

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

2009-03-01

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.

Design criteria for rhenium-reduced nickel-based single-crystal alloys. Identification and computer-assisted conversion

International Nuclear Information System (INIS)

Goehler, Thomas

2016-01-01

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 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 tungsten

27 CFR 25.186 - Record of beer transferred.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY LIQUORS BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred between...

The Influence of Cobalt and Rhenium on the Behaviour of MCrAlY Coatings

OpenAIRE

Täck, Ulrike

2009-01-01

Superalloys are widely applied as materials for components in the hot section of gas turbines. As superalloys have a limited oxidation life, the application of a coating is vital. The most commonly applied coatings in stationary gas turbines are MCrAlY coatings. Since the turbine components are exposed to high cyclic thermal stresses, MCrAlY coatings must also show a high thermal fatigue resistance. In this thesis, the effect of Cobalt and Rhenium on microstructure, oxidation and thermal fati...

77 FR 21538 - Announcing DRAFT Revisions to Federal Information Processing Standard (FIPS) 186-3, Digital...

Science.gov (United States)

2012-04-10

...-01] Announcing DRAFT Revisions to Federal Information Processing Standard (FIPS) 186-3, Digital... Technology (NIST) requests comments on revisions to Federal Information Processing Standard (FIPS) 186-3... 25, 2012. ADDRESSES: Written comments may be sent to: Chief, Computer Security Division, Information...

Country report: United Kingdom. Bifunctional bisphosphonate complexes with {sup 99m}Tc and {sup 188}Re for the diagnosis and therapy of bone metastases

Energy Technology Data Exchange (ETDEWEB)

Torres Martin de Rosales, Rafael; Blower, P.J., E-mail: rafael.torres@kcl.ac.uk, E-mail: philip.blower@kcl.ac.uk [Division of Imaging Sciences, King' s College London, 4th Floor, Lambeth Wing, St. Thomas Hospital, London (United Kingdom)

2010-07-01

1,1-Bisphosphonates (BPs) are a family of compounds extensively used in the management of disorders of bone metabolism.{sup 1} They accumulate in areas of high bone metabolism, such as bone metastases, and consequently have been receiving increasing attention as molecular imaging probes and pain palliation treatments.{sup 2} Imaging bone metastases with BPs using single photon emission computed tomography (SPECT) or planar scintigraphy is one of the most often-performed clinical imaging procedures. Beta-emitting analogues capable of producing a therapeutic effect have also been developed.{sup 3} In particular, the rhenium compounds {sup 186/188}Re-hydroxyethylidene-1,1-diphosphonate ({sup 186/188}Re-HEDP) have shown promise as palliative agents for bone metastases in recent clinical trials.{sup 4} The radiochemicals consist of a complex of a BP (e.g. methylene diphosphonate, MDP) with gamma- ({sup 99m}Tc) or beta- ({sup 186/186}Re) emitters.

Fate of rhenium in the environment as a chemical analogue of technetium

International Nuclear Information System (INIS)

Tagami, Keiko; Uchida, Shigeo

2007-01-01

Concentrations of rhenium, a chemical analogue of Tc, were measured in various environmental samples by ICP-MS to obtain information values on long-lived 99 Tc mobility in the environment. From the results, it was assumed that Re was removed from the rock and soil by water due to weathering and transport to the sea through rivers. The element would be retained in seawater for a long time, i.e., 2 x 10 5 to 7.5 x 10 5 y. The reservoirs of Re in the sea would be seaweeds, and anoxic and suboxic sediments, especially slightly below the water-sediment interface. (author)

Hot rocket plume experiment - Survey and conceptual design. [of rhenium-iridium bipropellants

Science.gov (United States)

Millard, Jerry M.; Luan, Taylor W.; Dowdy, Mack W.

1992-01-01

Attention is given to a space-borne engine plume experiment study to fly an experiment which will both verify and quantify the reduced contamination from advanced rhenium-iridium earth-storable bipropellant rockets (hot rockets) and provide a correlation between high-fidelity, in-space measurements and theoretical plume and surface contamination models. The experiment conceptual design is based on survey results from plume and contamination technologists throughout the U.S. With respect to shuttle use, cursory investigations validate Hitchhiker availability and adaptability, adequate remote manipulator system (RMS) articulation and dynamic capability, acceptable RMS attachment capability, adequate power and telemetry capability, and adequate flight altitude and attitude/orbital capability.

Issues associated with the use of the Tungsten-188/Rhenium188 generator and concentrator system and preparation of Re-188 HDD: A report

International Nuclear Information System (INIS)

Knapp, F.F.Jr.; Turner, J.H.; Jeong, J.-M.; Padhy, A.K.

2004-01-01

The ready availability of no-carrier-added Rhenium-188 from the Tungsten-188/Rhenium-188 generator represents an important source of a therapeutic radioisotope for a broad range of therapeutic applications in nuclear medicine, oncology, rheumatology and interventional cardiology. The International Atomic Energy Agency (IAEA) is coordinating a clinical trial involving the use of Rhenium188-Lipiodol for therapy of hepatocellular carcinoma. This report summarizes the experience of investigators at ten participating centres associated with the use and performance of the Tungsten-188/Rhenium-188 generators and the preparation and handling of the Re-188 HDD agent. This evaluation has demonstrated the cost effective provision of on-site therapeutic activities of Rhenium-188 and recommendations are made for further development of the next generator prototype in light of this international experience. The high bolus volumes (20-40 ml) of the ORNL generator requires post elution concentration of the Re-188 bolus by passage through the tandem silver cation/anion column system. The high back pressure often encountered during generator elution through the silver cation/anion concentrator system has been identified as a potential problem. The details of a method involving in house preparation of the silver cation columns were provided and implementation of this method for Re-188 bolus concentration is recommended. It is also recommended that ORNL investigators reassess the possibility of increasing Tungsten generator loading capacity and the use of higher specific activity Tungsten-188, with a view to reducing the generator bolus volume. The Re-188 HDD/Lipiodol conjugate?;ate is used in this IAEA trial for radioembolytic therapy of primary liver cancer, and methods for preparation of Re-188 HDD and its extraction into Lipiodol are discussed. Since Re-188 HDD binds to glass surfaces, the recovery yields are variable and can be as low as 40-45%. In an effort to maximize the

Structure of the Kπ = 4+ bands in 186,188Os

Science.gov (United States)

Phillips, A. A.; Garrett, P. E.; Bettermann, L.; Braun, N.; Burke, D. G.; Demand, G. A.; Faestermann, T.; Finlay, P.; Green, K. L.; Hertenberger, R.; Krü; cken, R.; Leach, K. G.; Schumaker, M. A.; Svensson, C. E.; Wirth, H.-F.; Wong, J.

2009-01-01

The structures of 3+ states in Os have been debated over several decades. Based on measured B(E2) values they were interpreted in 186-192Os as Kπ = 4+ two-phonon vibrations, whereas inelastic scattering, and (t,α) work imply a hexadecapole phonon description. To clarify the nature of these Kπ = 4+ bands in 186,188Os, we performed a (3He,d) reaction on 185,187Re targets using 30 MeV 3He beams and a Q3D spectrograph. Absolute cross sections were obtained for excited states up to 3 MeV at 9 angles from 5° to 50°. Results indicate a significant 5/2+[402]π+3/2+[402]π component in agreement with quasiparticle phonon model predictions for a single hexadecapole phonon structure.

Elementary steps of the catalytic oxidation of CO in a gas phase in the presence of rhenium cations with carbonyl and oxygen ligands: a comparison with heterogeneous catalysis

International Nuclear Information System (INIS)

Goncharov, V.B.; Fialko, E.F.; Shejnin, D.Eh.; Kikhtenko, A.V.

1997-01-01

Reactivity in a gaseous phase o rhenium (Re + ) and rhenium monocarbonyl (ReCO + ) in the reaction of CO oxidation in oxygen-containing reagents (NO, O 2 , H 2 O) is studied through the method of the ionic cyclotron resonance. It is shown that presence of carbonyl ligand essentially influences the ion reactivity. The effective channel of the metal monocarbonyl ions oxidation through molecular oxygen is found. Accounting for this stage makes of possible to explain the low-temperature activity of a number of oxide catalyzer Mo, W in the reaction of CO oxidation by molecular oxygen

TEM microstructural analysis of creep deformed CM186LC single crystal Ni-base superalloy

Energy Technology Data Exchange (ETDEWEB)

Dubiel, B.; Czyrska-Filemonowicz, A. [AGH Univ. of Science and Technology, Krakow (Poland); Blackler, M. [Howmet Ltd., Exeter (United Kingdom); Barnard, P.M. [ALSTOM Power Turbo-Systems Technology Centre, Rugby (United Kingdom)

2006-07-01

The nickel based single crystal superalloy CM186LC was extensively investigated as a potential low cost material for industrial gas turbine vanes within the COST522 programme. The alloy exhibits inhomogeneous structure consisting of dendritic regions and eutectic colonies. In the present work attention is focused on microstructural changes observed in single crystal CM186LC following creep deformation at 750 C. Creep tests were conducted at 750 C with an applied stress of 560 or 675 MPa for up to 11440 hours. The microstructure o ruptured and terminated specimens was investigated by scanning (SEM) and transmission (TEM) electron microscopy. TEM analysis revealed the microstructural changes in the CM186LC at primary and secondary creep as well as after creep rupture. (orig.)

Mass spectrometry of rhenium complexes: a comparative study by using LDI-MS, MALDI-MS, PESI-MS and ESI-MS.

Science.gov (United States)

Petroselli, Gabriela; Mandal, Mridul Kanti; Chen, Lee Chuin; Ruiz, Gustavo T; Wolcan, Ezequiel; Hiraoka, Kenzo; Nonami, Hiroshi; Erra-Balsells, Rosa

2012-03-01

A group of rhenium (I) complexes including in their structure ligands such as CF(3)SO(3)-, CH(3)CO(2)-, CO, 2,2'-bipyridine, dipyridil[3,2-a:2'3'-c]phenazine, naphthalene-2-carboxylate, anthracene-9-carboxylate, pyrene-1-carboxylate and 1,10-phenanthroline have been studied for the first time by mass spectrometry. The probe electrospray ionization (PESI) is a technique based on electrospray ionization (ESI) that generates electrospray from the tip of a solid metal needle. In this work, mass spectra for organometallic complexes obtained by PESI were compared with those obtained by classical ESI and high flow rate electrospray ionization assisted by corona discharge (HF-ESI-CD), an ideal method to avoid decomposition of the complexes and to induce their oxidation to yield intact molecular cation radicals in gas state [M](+·) and to produce their reduction yielding the gas species [M](-·). It was found that both techniques showed in general the intact molecular ions of the organometallics studied and provided additional structure characteristic diagnostic fragments. As the rhenium complexes studied in the present work showed strong absorption in the UV-visible region, particularly at 355 nm, laser desorption ionization (LDI) mass spectrometry experiments could be conducted. Although intact molecular ions could be detected in a few cases, LDI mass spectra showed diagnostic fragments for characterization of the complexes structure. Furthermore, matrix-assisted laser desorption ionization (MALDI) mass spectra were obtained. Nor-harmane, a compound with basic character, was used as matrix, and the intact molecular ions were detected in two examples, in negative ion mode as the [M](-·) species. Results obtained with 2-[(2E)-3-(4-tert-buthylphenyl)-2-methylprop-2-enylidene] malononitrile (DCTB) as matrix are also described. LDI experiments provided more information about the rhenium complex structures than did the MALDI ones. Copyright © 2012 John Wiley & Sons, Ltd.

Rhenium(5) and molybdenum(5) complexes with 4',4(5)-divaleryldibenzo-18-crown-6

International Nuclear Information System (INIS)

Ashurova, N.Kh.; Yakubov, K.G.; Tashmukhamedova, A.K.; Basitova, S.M.

1993-01-01

Methods for synthesizing oxohalide complexes of rhenium and molybdenum with +5 oxidation degree with 4',4 (5) -divaleryldibenzo-18-crown-6 were developed. Content and composition of prepared compounds were investigated by the methods of element analysis, crystal optics, conductometry, IR spectroscopy in the near and far regions, thermogravimetry. Oxidation degree of the complex-forming metal was determined. It was established that composition of the compounds coressponded to the general formula MOLX · H 2 O, where M - Re, Mo; L -4',4 (5) -divaleryldibenzo-18-crown-6; X -Cl - , Br -

Mechanical properties of tungsten following rhenium ion and helium plasma exposure

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C.S. Corr

2017-08-01

Full Text Available Mechanical properties of Tungsten (W samples irradiated with 2 MeV Rhenium (Re ions and helium (He plasma were investigated using nanoindentation. It was found that there was an increase in hardness for all samples following separate irradiation with both Re ion and He plasma. A slight increase in hardness was obtained for combined exposures. A comparable increase in hardness was observed for a pure He plasma with a sample temperature of 473 K and 1273 K. Optical interferometry was employed to compare surface modification of the samples. Grazing incidence small angle x-ray scattering confirmed He nano-bubble formation of approximately 1 nm diameter in the higher temperature sample, which was not observed with samples at the lower temperatures.

Rhenium Dichalcogenides: Layered Semiconductors with Two Vertical Orientations.

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Hart, Lewis; Dale, Sara; Hoye, Sarah; Webb, James L; Wolverson, Daniel

2016-02-10

The rhenium and technetium diselenides and disulfides are van der Waals layered semiconductors in some respects similar to more well-known transition metal dichalcogenides (TMD) such as molybdenum sulfide. However, their symmetry is lower, consisting only of an inversion center, so that turning a layer upside-down (that is, applying a C2 rotation about an in-plane axis) is not a symmetry operation, but reverses the sign of the angle between the two nonequivalent in-plane crystallographic axes. A given layer thus can be placed on a substrate in two symmetrically nonequivalent (but energetically similar) ways. This has consequences for the exploitation of the anisotropic properties of these materials in TMD heterostructures and is expected to lead to a new source of domain structure in large-area layer growth. We produced few-layer ReS2 and ReSe2 samples with controlled "up" or "down" orientations by micromechanical cleavage and we show how polarized Raman microscopy can be used to distinguish these two orientations, thus establishing Raman as an essential tool for the characterization of large-area layers.

Superhard Rhenium/Tungsten Diboride Solid Solutions.

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Lech, Andrew T; Turner, Christopher L; Lei, Jialin; Mohammadi, Reza; Tolbert, Sarah H; Kaner, Richard B

2016-11-02

Rhenium diboride (ReB 2 ), containing corrugated layers of covalently bonded boron, is a superhard metallic compound with a microhardness reaching as high as 40.5 GPa (under an applied load of 0.49 N). Tungsten diboride (WB 2 ), which takes a structural hybrid between that of ReB 2 and AlB 2 , where half of the boron layers are planar (as in AlB 2 ) and half are corrugated (as in ReB 2 ), has been shown not to be superhard. Here, we demonstrate that the ReB 2 -type structure can be maintained for solid solutions of tungsten in ReB 2 with tungsten content up to a surprisingly large limit of nearly 50 atom %. The lattice parameters for the solid solutions linearly increase along both the a- and c-axes with increasing tungsten content, as evaluated by powder X-ray and neutron diffraction. From micro- and nanoindentation hardness testing, all of the compositions within the range of 0-48 atom % W are superhard, and the bulk modulus of the 48 atom % solid solution is nearly identical to that of pure ReB 2 . These results further indicate that ReB 2 -structured compounds are superhard, as has been predicted from first-principles calculations, and may warrant further studies into additional solid solutions or ternary compounds taking this structure type.

Coliphage 186 replication is delayed when the host cell is UV irradiated before infection

International Nuclear Information System (INIS)

Hooper, I.; Woods, W.H.; Egan, B.

1981-01-01

In contrast to results with injections by lambda and P2, the latent period for infection by coliphage 186 is extended when the host cell is UV irradiated before infection. We find that 186 replication is significantly delayed in such a cell, even though the phage itself has not been irradiated. In contrast, replication of the closely related phage P2 under the same conditions is not affected

Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

Czech Academy of Sciences Publication Activity Database

Kučera, Jan; Byrne, A. R.; Mizera, Jiří; Lučaníková, M.; Řanda, Zdeněk

2006-01-01

Roč. 269, č. 2 (2006), s. 251-257 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA203/04/0943 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiochemical neutron activation analysis * rhenium * biological and environmental samples Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.509, year: 2006

Photocatalytic Conversion of CO2 to CO using Rhenium Bipyridine Platforms Containing Ancillary Phenyl or BODIPY Moieties

Science.gov (United States)

Andrade, Gabriel A.; Pistner, Allen J.; Yap, Glenn P.A.; Lutterman, Daniel A.; Rosenthal, Joel

2013-01-01

Harnessing of solar energy to drive the reduction of carbon dioxide to fuels requires the development of efficient catalysts that absorb sunlight. In this work, we detail the synthesis, electrochemistry and photophysical properties of a set of homologous fac-ReI(CO)3 complexes containing either an ancillary phenyl (8) or BODIPY (12) substituent. These studies demonstrate that both the electronic properties of the rhenium center and BODIPY chromophore are maintained for these complexes. Photolysis studies demonstrate that both assemblies 8 and 12 are competent catalysts for the photochemical reduction of CO2 to CO in DMF using triethanolamine (TEOA) as a sacrificial reductant. Both compounds 8 and 12 display TOFs for photocatalytic CO production upon irradiation with light (λex ≥ 400 nm) of ~5 hr−1 with TON values of approximately 20. Although structural and photophysical measurements demonstrate that electronic coupling between the BODIPY and fac-ReI(CO)3 units is limited for complex 12, this work clearly shows that the photoactive BODIPY moiety is tolerated during catalysis and does not interfere with the observed photochemistry. When taken together, these results provide a clear roadmap for the development of advanced rhenium bipyridine complexes bearing ancillary BODIPY groups for the efficient photocatalytic reduction of CO2 using visible light. PMID:24015374

Palliative effect of Re-186 HEDP in different cancer patients with bone metastases

International Nuclear Information System (INIS)

Kucuk, N.O.; Ibis, E.; Aras, G.; Soylu, A.; Baltaci, S.; Beduk, Y.; Ozalp, G.; Canakci, N.

2001-01-01

The clinical picture of bone metastases is manifested by pain and loss of mechanical stability. Standard treatment options for bone metastases include external beam radiotherapy and the use of analgesics. Due to a large number of lesions in many patients, the use of radionuclide therapy with beta emitters may be preferable. Re-186 hydroxyethydilene diphosphonate (Re-186 HEDP) is one of the radiopharmaceuticals suitable for palliative treatment of metastatic bone pain. The aim of this study was to investigate palliative and side effects of Re-186 HEDP in pts with different type of cancers. Material and method: Thirty one (17 male, 14 female) patients with cancer (10 prostate, 10 breast, 4 rectum, 5 lung, 2 nasopharynx) and bone metastases were included in the study. Therapy was started with a fixed dose of 1295 MBq of Re-186 HEDP. If necessary, the same dose was repeated at least 3 times after an interval of 10-12 weeks A total of 40 standard doses (1295 MBq Re HEDP, Mallinckrodt, Holland) were given; 6 pts received repeated doses (3 doses in 3 pts, 2 doses in 3 pts). The pts with bone marrow suppression were excluded from the study. The pain relief was assessed with ECOG and Karnofsky status index. All pts were evaluated with standard evaluation forms filled daily a maximum of 10 weeks. Results: The respond rate was found as 87.5% in pts with breast and prostate Ca, 75% in pts with rectum Ca, 50% in pts with nasopharynx Ca and 20% in pts with lung Ca. The overall response rate was 67.5%. The palliation period varied between 6 to 10 weeks. The mean palliation period was 8.1 ± 1.3 weeks. Maximal palliation effect was observed between the 3 rd and the 7 th weeks. Any serious side effects were not seen except mild haematologic toxicity. Discussion and conclusion: It is concluded that Re-186 HEDP is a highly effective agent in the palliation of metastatic bone pain in pts with prostate, breast, rectum cancer, mildly effective in pts with nasopharynx cancer, but not

Rhenium and technetium complexes with phenylbis(2-pyridyl)phosphine and tris(2-pyridyl)phosphine

Energy Technology Data Exchange (ETDEWEB)

Saucedo A, S. A. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Hagenbach, A.; Abram, U., E-mail: ssaucedo@uaz.edu.m [Institut fur Chemie und Biochemie, Freie Universitat Berlin, Fabeckstr. 34-36, D-14195, Berlin (Germany)

2010-10-15

Reactions of common technetium and rhenium precursors with 2-pyridyl phosphines produce novel, air stable tricarbonyl and oxo complexes. (NEt{sub 4}){sub 2}[Re(CO){sub 3}Br{sub 3}] or (NEt{sub 4}){sub 2}[Tc(CO){sub 3}Cl{sub 3}] react with phenylbis(2-pyridyl)phosphine (PPhpy{sub 2}) or tris(2-pyridyl)phosphine (Ppy{sub 3}) under formation of neutral tricarbonyl complexes of the composition [M(CO){sub 3}X(L)] (M = Re, X = Br; M = Tc, X = Cl, L = PPhpy{sub 2} or Ppy{sub 3}), where the ligands coordinate only with two for their nitrogen atoms. Removal of the bromo ligands from (NEt{sub 4}){sub 2}[Re(CO){sub 3}(Br){sub 3}] with AgNO{sub 3}, to force a tripodal coordination, and the subsequent reaction with the Ppy{sub 3} results in the formation of the complex [Re(CO){sub 3}(NO{sub 3})(Ppy{sub 3}{sup -}N,N{sup '})] with a monodentate coordinated nitrato ligand. (NBu{sub 4})[ReOCl{sub 4}] reacts with PPhpy{sub 2} to give the asymmetric, oxo-bridged rhenium (V) dimer (NBu{sub 4})[Re{sub 2}O{sub 2}Cl{sub 5}({mu}-PPhpy{sub 2}{sup -}P,N,N,N{sup '})({mu}-O)], while a similar reaction with (ReOCl{sub 3}(PPh{sub 3}){sub 2}] in boiling Thf results in reduction of the metal and gives (ReCl{sub 3}(OPPhpy{sub 2})(PPh{sub 3})]. The products have been characterized spectroscopically and by X-ray structure analyses. (Author)

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

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Thomas L. Mindt

2013-03-01

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.

Catalytic transformation of functionalized carboxylic acids using multifunctional rhenium complexes.

Science.gov (United States)

Naruto, Masayuki; Agrawal, Santosh; Toda, Katsuaki; Saito, Susumu

2017-06-13

Carboxylic acids (CAs) are one of the most ubiquitous and important chemical feedstocks available from biorenewable resources, CO 2 , and the petrochemical industry. Unfortunately, chemoselective catalytic transformations of CH n CO 2 H (n = 1-3) groups into other functionalities remain a significant challenge. Herein, we report rhenium V complexes as extremely effective precatalysts for this purpose. Compared to previously reported heterogeneous and homogeneous catalysts derived from high- or low-valent metals, the present method involves a α-C-H bond functionalization, a hydrogenation, and a hydrogenolysis, which affords functionalized alcohols with a wide substrate scope and high chemoselectivity under relatively mild reaction conditions. The results represent an important step toward a paradigm shift from 'low-valent' to 'high-valent' metal complexes by exploring a new portfolio of selective functional group transformations of highly oxygenated organic substrates, as well as toward the exploitation of CAs as a valuable biorenewable feedstock.

Contactin-1 and Neurofascin-155/-186 Are Not Targets of Auto-Antibodies in Multifocal Motor Neuropathy.

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Kathrin Doppler

Full Text Available Multifocal motor neuropathy is an immune mediated disease presenting with multifocal muscle weakness and conduction block. IgM auto-antibodies against the ganglioside GM1 are detectable in about 50% of the patients. Auto-antibodies against the paranodal proteins contactin-1 and neurofascin-155 and the nodal protein neurofascin-186 have been detected in subgroups of patients with chronic inflammatory demyelinating polyneuropathy. Recently, auto-antibodies against neurofascin-186 and gliomedin were described in more than 60% of patients with multifocal motor neuropathy. In the current study, we aimed to validate this finding, using a combination of different assays for auto-antibody detection. In addition we intended to detect further auto-antibodies against paranodal proteins, specifically contactin-1 and neurofascin-155 in multifocal motor neuropathy patients' sera. We analyzed sera of 33 patients with well-characterized multifocal motor neuropathy for IgM or IgG anti-contactin-1, anti-neurofascin-155 or -186 antibodies using enzyme-linked immunosorbent assay, binding assays with transfected human embryonic kidney 293 cells and murine teased fibers. We did not detect any IgM or IgG auto-antibodies against contactin-1, neurofascin-155 or -186 in any of our multifocal motor neuropathy patients. We conclude that auto-antibodies against contactin-1, neurofascin-155 and -186 do not play a relevant role in the pathogenesis in this cohort with multifocal motor neuropathy.

UV induction of coliphage 186: Prophage induction as an SOS function

Energy Technology Data Exchange (ETDEWEB)

Lamont, I.; Brumby, A.M.; Egan, J.B.

1989-07-01

Our results show that UV induction of the 186 prophage depends upon the phage function Tum, with the mutant phenotype of turbid plaques on mitomycin plates and the expression of which is controlled by the host LexA protein. Tum function, encoded near the right-hand end of the coliphage 186 chromosome, is under the control of promoter p95. This promoter is overlapped by a sequence closely related to the consensus sequence of the LexA-binding site. It is proposed that inactivation of LexA after UV irradiation (or by genetic means) leads to prophage induction by permitting expression of Tum which, by unknown means, induces prophage. This mechanism is basically different from that seen with the UV-inducible lambdoid coliphages, which are not regulated by LexA.

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

Science.gov (United States)

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

2013-03-25

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.

Post-hoc analysis of MCI186-17, the extension study to MCI186-16, the confirmatory double-blind, parallel-group, placebo-controlled study of edaravone in amyotrophic lateral sclerosis.

Science.gov (United States)

Takahashi, Fumihiro; Takei, Koji; Tsuda, Kikumi; Palumbo, Joseph

2017-10-01

In the 24-week double-blind study of edaravone in ALS (MCI186-16), edaravone did not show a statistically significant difference versus placebo for the primary efficacy endpoint. For post-hoc analyses, two subpopulations were identified in which edaravone might be expected to show efficacy: the efficacy-expected subpopulation (EESP), defined by scores of ≥2 points on all 12 items of the ALS Functional Rating Scale-Revised (ALSFRS-R) and a percent predicted forced vital capacity (%FVC) ≥80% at baseline; and the definite/probable EESP 2 years (dpEESP2y) subpopulation which, in addition to EESP criteria, had definite or probable ALS diagnosed by El Escorial revised criteria, and disease duration of ≤2 years. In the 36-week extension study of MCI186-16, a 24-week double-blind comparison followed by 12 weeks of open-label edaravone (MCI186-17; NCT00424463), analyses of ALSFRS-R scores of the edaravone-edaravone group and edaravone-placebo group for the full analysis set (FAS) and EESP, as prospectively defined, were reported in a previous article. Here we additionally report results in patients who met dpEESP2y criteria at the baseline of MCI186-16. In the dpEESP2y, the difference in ALSFRS-R changes from 24 to 48 weeks between the edaravone-edaravone and edaravone-placebo groups was 2.79 (p = 0.0719), which was greater than the differences previously reported for the EESP and the FAS. The pattern of adverse events in the dpEESP2y did not show any additional safety findings to those from the earlier prospective study. In conclusion, this post-hoc analysis suggests a potential effect of edaravone between 24 and 48 weeks in patients meeting dpEESP2y criteria at baseline.

Experimental determination of the hydrothermal solubility of ReS2 and the Re–ReO2 buffer assemblage and transport of rhenium under supercritical conditions

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Wood Scott A

2002-01-01

Full Text Available To understand the aqueous species important for transport of rhenium under supercritical conditions, we conducted a series of solubility experiments on the Re–ReO2 buffer assemblage and ReS2. In these experiments, pH was buffered by the K–feldspar–muscovite–quartz assemblage; in sulfur-free systems was buffered by the Re–ReO2 assemblage; and and in sulfur-containing systems were buffered by the magnetite–pyrite–pyrrhotite assemblage. Our experimental studies indicate that the species ReCl40 is dominant at 400°C in slightly acidic to near-neutral, and chloride-rich (total chloride concentrations ranging from 0.5 to 1.0 M environments, and ReCl3+ may predominate at 500°C in a solution with total chloride concentrations ranging from 0.5 to 1.5 M. The results also demonstrate that the solubility of ReS2 is about two orders of magnitude less than that of ReO2. This finding not only suggests that ReS2 (or a ReS2 component in molybdenite is the solubility-controlling phase in sulfur-containing, reducing environments but also implies that a mixing process involving an oxidized, rhenium-containing solution and a solution with reduced sulfur is one of the most effective mechanisms for deposition of rhenium. In analogy with Re, TcS2 may be the stable Tc-bearing phase in deep geological repositories of radioactive wastes.

Tracing oxidative weathering from the Andes to the lowland Amazon Basin using dissoved rhenium

Science.gov (United States)

Dellinger, M.; Hilton, R. G.; West, A. J.; Torres, M.; Burton, K. W.; Clark, K. E.; Baronas, J. J.

2016-12-01

Over long timescales (>105 yrs), the abundance of carbon dioxide (CO2) in the atmosphere is determined by the balance of the major carbon sources and sinks. Among the major carbon sources, the oxidation of organic carbon contained within sedimentary rocks ("petrogenic" carbon, or OCpetro) is thought to result in CO2 emission of similar magnitude to that released by volcanism. Rhenium (Re) has been proposed as a proxy for tracing OCpetro oxidation. Here we investigate the source, behavior and flux of dissolved and particulate rhenium (Re) in the Madre de Dios watershed (a major Andean tributary of the Amazon River) and the lowlands, aiming to characterize the behavior of Re in river water and quantify the flux of CO2 released by OCpetro oxidation. Measured Re concentrations in Andean rivers range from 0.07 to 1.55 ppt. In the Andes, Re concentration do not change significantly with water discharge, whereas in the lowlands, Re concentration decrease at high water discharge. Mass balance calculation show that more than 70% of the dissolved Re is sourced from the oxidation of OCpetro the Andes-floodplain system. We calculate dissolved Re flux over a hydrological year to estimate the rates of oxidative weathering, and the associated CO2 release from OCpetro. Rates are high in the Andean headwaters, consistent with estimates from other mountain rivers with similar rates of physical erosion. We find evidence that a significant amount of additional oxidation (Re flux) happens during floodplain transport. These results have important implications for improving our understanding of the source and processes controlling Re in rivers, and allowing us to quantify long-term OCpetro cycling in large river basins.

19 CFR 18.6 - Short shipments; shortages; entry and allowance.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Short shipments; shortages; entry and allowance...; DEPARTMENT OF THE TREASURY TRANSPORTATION IN BOND AND MERCHANDISE IN TRANSIT General Provisions § 18.6 Short shipments; shortages; entry and allowance. (a) When there has been a short shipment and the short-shipped...

Effect of rhenium and osmium on mechanical properties of a 9Cr-2W-0.25V-0.07Ta-0.1C steel

International Nuclear Information System (INIS)

Klueh, R.L.; Alexander, D.J.; Sokolov, M.A.

2000-01-01

The nuclear transmutation of tungsten to rhenium and osmium in a tungsten-containing steel irradiated in a fission or fusion reactor will change the chemical composition of the steel. To determine the possible consequences of such compositional changes on the mechanical properties, tensile and Charpy impact properties were measured on five 9Cr-2W-0.25V-0.07Ta-0.1C steels that contained different amounts of rhenium, osmium, and tungsten. The mechanical properties changes caused by these changes in composition were minor. Observations were also made on the effect of carbon concentration. The effect of carbon on tensile behavior was minor, but there was a large effect on Charpy properties. Several of the steels showed little effect of tempering temperature on the Charpy transition temperature, a behavior that was tentatively attributed to the low silicon and/or manganese concentration of the experimental steels

Absorption behavior of technetium and rhenium through plant roots

International Nuclear Information System (INIS)

Tagami, K.; Uchida, S.

2004-01-01

The absorption behavior of technetium (Tc) and rhenium (Re) through plant roots was studied using nutrient solution culture. Radish samples, grown in culture solutions for 20-30 days in a green house, were transferred into plastic vessels containing nutrient solutions contaminated with multi-tracer solutions including Tc-95m and Re-183. The plant samples were grown individually for 1-7 days under laboratory conditions. The activities of radionuclides in nutrient solutions and oven-dried plant parts (roots, fleshy roots and leaves) were measured with Ge detecting systems. The concentrations of Tc-95m and Re-183 in the nutrient solutions after harvesting the plants were almost the same as those in the initial solution. Possibly, the radionuclides were taken up with water through plant roots. The distributions of Tc and Re in the plants showed no differences, thus, soluble Tc and Re absorption by plant samples were the same. It is suggested that Re could be used as a geochemical tracer of Tc in the soil environment. (author)

A tungsten-rhenium interatomic potential for point defect studies

Science.gov (United States)

Setyawan, Wahyu; Gao, Ning; Kurtz, Richard J.

2018-05-01

A tungsten-rhenium (W-Re) classical interatomic potential is developed within the embedded atom method interaction framework. A force-matching method is employed to fit the potential to ab initio forces, energies, and stresses. Simulated annealing is combined with the conjugate gradient technique to search for an optimum potential from over 1000 initial trial sets. The potential is designed for studying point defects in W-Re systems. It gives good predictions of the formation energies of Re defects in W and the binding energies of W self-interstitial clusters with Re. The potential is further evaluated for describing the formation energy of structures in the σ and χ intermetallic phases. The predicted convex-hulls of formation energy are in excellent agreement with ab initio data. In pure Re, the potential can reproduce the formation energies of vacancies and self-interstitial defects sufficiently accurately and gives the correct ground state self-interstitial configuration. Furthermore, by including liquid structures in the fit, the potential yields a Re melting temperature (3130 K) that is close to the experimental value (3459 K).

Pox 186: An ultracompact galaxy with dominant ionized gas emission

Science.gov (United States)

Guseva, N. G.; Papaderos, P.; Izotov, Y. I.; Noeske, K. G.; Fricke, K. J.

2004-07-01

We present a ground-based optical spectroscopic and HST U, V, I photometric study of the blue compact dwarf (BCD) galaxy Pox 186. It is found that the emission of the low-surface brightness (LSB) component in Pox 186 at radii ⪉3 arcsec (⪉270 pc in linear scale) is mainly gaseous in origin. We detect Hα emission out to radii as large as 6 arcsec. At radii ⪆3 arcsec the light of the LSB component is contaminated by the emission of background galaxies complicating the study of the outermost regions. The surface brightness distribution in the LSB component can be approximated by an exponential law with a scale length α ⪉ 120 pc. This places Pox 186 among the most compact dwarf galaxies known. The derived α is likely to be an upper limit to the scale length of the LSB component because of the strong contribution of the gaseous emission. The oxygen abundance in the bright H II region derived from the 4.5 m Multiple Mirror Telescope (MMT) and 3.6 m ESO telescope spectra are 12 + log (O/H) = 7.76 ± 0.02 and 7.74 ± 0.01 (˜Z⊙/15), respectively, in accordance with previous determinations. The helium mass fractions found in this region are Y = 0.248 ± 0.009 (MMT) and Y = 0.248 ± 0.004 (3.6 m) suggesting a high primordial helium abundance. The MMT Observatory is a joint facility of the Smithsonian Institution and the University of Arizona. Based on observations collected at the European Southern Observatory, Chile, ESO program 71.B-0032(A). 12+\\log(O/H)⊙ = 8.92 (Anders & Grevesse \\cite{Anders89}).

Determination of (187)Os in molybdenite by ICP-MS with neutron-induced (186)Os and (188)Os spikes.

Science.gov (United States)

Qu, W; Du, A; Zhao, D

2001-10-31

The article describes a method for the determination of (187)Os in molybdenite by isotope dilution inductively coupled plasma-mass spectrometry (ID-ICP-MS) with neutron-induced (186)Os and (188)Os spike. The spike used in the present work was prepared in line with the principle by which artificial nuclides are produced in a nuclear reaction. The concentration and isotopic composition of osmium in the prepared spike were evaluated accurately with the isotope dilution method, using negative thermal ion mass spectrometry (N-TIMS). The advantage of this method is that using (186)Os and (188)Os double spikes can effectively compensate for the mass discrimination effects of ICP-MS. Thus, the common correction practice for mass bias in the isotope dilution method with a single spike is unnecessary. In addition, the method enables one to reduce the determined error arising from instrumental instability. The precision for the (187)Os/((186)Os+(188)Os) ratio was approximately 2% (2sigma, RSD), but in the case of (187)Os/(186)Os, (187)Os/(188)Os and (186)Os/(188)Os, precision ranged from 2.0 to 8% (2sigma, RSD). The results for (187)Os concentration in a molybdenite sample determined with this method showed good agreement with reference values.

Rhenium(V) and technetium(V) complexes of bis(o-hydroxyphenyl)phenylphosphine (PO22-) and (o-hydroxyphenyl)diphenylphosphine (PO-) ligands

International Nuclear Information System (INIS)

Luo, Hongyan; Setyawati, Ika; Rettig, S.J.; Orvig, C.

1995-01-01

The synthesis of several phosphine-based chelating compounds and chelates formed between these compounds and rhenium or technetium is discussed. Four categories of products result, (i) bis-(o-hydroxyphenyl) diphenylphosphine (PO) complexes, (ii) mono- (PO) complexes, (iii) bis-bis(o-hydroxyphenyl)-phenylphosphine (PO 2 ) complexes, and mixed-(PO) and (PO 2 ) complexes. Molecular structures of these compounds (including isomers) were probed by NMR, MS, and IR spectroscopies and by X-ray crystallography

Ultrafast Excited-State Dynamics of Rhenium(I) Photosensitizers [Re(Cl)(CO)3(N,N)] and [Re(imidazole)(CO)3(N,N)]+: Diimine Effects

Czech Academy of Sciences Publication Activity Database

Nahhas, A. E.; Consani, C.; Blanco-Rodríguez, A. M.; Lancaster, K. M.; Braem, O.; Cannizzo, A.; Towrie, M.; Clark, I. P.; Záliš, Stanislav; Chergui, M.; Vlček, Antonín

2011-01-01

Roč. 50, č. 7 (2011), s. 2932-2943 ISSN 0020-1669 R&D Projects: GA MŠk(CZ) ME10124; GA MŠk(CZ) LD11082 Institutional research plan: CEZ:AV0Z40400503 Keywords : rhenium * photosynthesis * diimine effects Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.601, year: 2011

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

International Nuclear Information System (INIS)

Pillai, M.R.A.; Dash, A.; Knapp, Russ F. Jr.

2012-01-01

Rhenium-188 is one of the most readily available generator derived and useful radionuclides for therapy emitting β-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.

186Re-HEDP for metastatic bone pain in breast cancer patients

International Nuclear Information System (INIS)

Lam, Marnix G.E.H.; Rijk, Peter P. van; Klerk, John M.H. de

2004-01-01

Two-thirds of patients with metastatic cancer suffer from pain. Pain originating from skeletal metastases is the most common form of cancer-related pain. Bone pain, often exacerbated by pressure or movement, limits the patient's autonomy and social life. Pain palliation with bone-seeking radiopharmaceuticals has proven to be an effective treatment modality in patients with metastatic bone pain. These bone-seeking radiopharmaceuticals are extremely powerful in treating scattered painful bone metastases, for which external beam radiotherapy is impossible because of the large field of irradiation. 186 Re-hydroxyethylidene diphosphonate (HEDP) is a potentially useful radiopharmaceutical for this purpose, having numerous advantageous characteristics. Bone marrow toxicity is limited and reversible, which makes repetitive treatment safe. Studies have shown encouraging clinical results of palliative therapy using 186 Re-HEDP, with an overall response rate of ca. 70% in painful bone metastases. It is effective for fast palliation of painful bone metastases from various tumours and the effect tends to last longer if patients are treated early in the course of their disease. 186 Re-HEDP is at least as effective in breast cancer patients with painful bone metastases as in patients with metastatic prostate cancer. It is to be preferred to radiopharmaceuticals with a long physical half-life in this group of patients, who tend to have more extensive haematological toxicity since they have frequently been pretreated with bone marrow suppressive chemotherapy. This systemic form of radionuclide therapy is simple to administer and complements other treatment options. It has been associated with marked pain reduction, improved mobility in many patients, reduced dependence on analgesics, and improved performance status and quality of life. (orig.)

Synthesis, characterization, and photophysical properties of a thiophene-functionalized bis(pyrazolyl) pyridine (BPP) tricarbonyl rhenium(I) complex.

Science.gov (United States)

Lytwak, Lauren A; Stanley, Julie M; Mejía, Michelle L; Holliday, Bradley J

2010-09-07

A bromo tricarbonyl rhenium(I) complex with a thiophene-functionalized bis(pyrazolyl) pyridine ligand (L), ReBr(L)(CO)(3) (1), has been synthesized and characterized by variable temperature and COSY 2-D (1)H NMR spectroscopy, single-crystal X-ray diffraction, and photophysical methods. Complex 1 is highly luminescent in both solution and solid-state, consistent with phosphorescence from an emissive (3)MLCT excited state with an additional contribution from a LC (3)(pi-->pi*) transition. The single-crystal X-ray diffraction structure of the title ligand is also reported.

Evaluation of a new component used for isotopic lymphography: colloidal rhenium sulfide sup(99m)Tc labelled

International Nuclear Information System (INIS)

Pecking, A.; Le Mercier, N.; Gobin, R.; Bardy, A.; Najean, Y.

1978-01-01

We have studied for lymphatic scintigraphy a new radiopharmaceutical, sup(99m)Tc-labelled rhenium sulfocolloid. This preliminary study includes 20 adults patients with lymphomas and lymphoedemas. The principal advantage of this drug is its absence of toxicity and local pain, so that a rapid sub-cutaneous injection without local anesthesia is made possible. Good results have been obtained, as well in morphological studies of para-aortic and mammary lymph nodes as for kinetic studies of lymphatic flow in lymphoedemas. No liver and spleen uptake of radio-isotope was observed after foot injection [fr

TUG1 mediates methotrexate resistance in colorectal cancer via miR-186/CPEB2 axis.

Science.gov (United States)

Li, Changfeng; Gao, Yongjian; Li, Yongchao; Ding, Dayong

2017-09-16

Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. Methotrexate (MTX) is one of the earliest cytotoxic drugs and serves as an anti-metabolite and anti-folate chemotherapy for various types of cancer. However, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the efficacy of MTX therapies in clinics. Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years. More and more evidences have shown that lncRNAs play regulatory roles in various biological activities and disease progression including drug resistance in cancer cells. Here, we observed lncRNA TUG1 was associated to the MTX resistant in colorectal cancer cells. Firstly, quantitative analysis indicated that TUG1 was significantly increased in tumors which were resistant to MTX treatment. TUG1 knockdown re-sensitized the MTX resistance in colorectal cancer cells, which were MTX-resistant colorectal cell line. Furthermore, bioinformatics analysis showed that miR-186 could directly bind to TUG1, suggesting TUG1 might worked as a ceRNA to sponge miR-186. Extensively, our study also showed that CPEB2 was the direct target of miR-186 in colorectal cancer cells. Taken together, our study suggests that lncRNA TUG1 mediates MTX resistance in colorectal cancer via miR-186/CPEB2 axis. Copyright © 2017. Published by Elsevier Inc.

The evaluation and calculation of production cross sections of {sup 18}F, {sup 77}Br and {sup 186}Re medical radioisotopes from {sup 18}O, {sup 77}Se and {sup 186}W(p,n) reactions up to 80 MeV

Energy Technology Data Exchange (ETDEWEB)

Youxiang, Zhuang [Chinese Nuclear Data Center, Beijing, BJ (China)

1996-06-01

The medical radioisotopes are used for diagnostic and therapeutic purposes, as well as metabolism and physiological function researches in modern medicine. The major applications are of functional imaging using PET agents for {sup 18}F, various therapeutic pharmaceuticals via auger electrons for {sup 77}Br, cancers diagnosis and therapy for {sup 186}Re. The evaluations of experimental data and theoretical calculations for {sup 18}O, {sup 77}Se, {sup 187}W(p,n) reactions up to 80 MeV are presented and analysed. The recommended values for {sup 18}O(p,n){sup 18}F, {sup 77}Se(p,n){sup 77}Br and {sup 186}W(p,n){sup 186}Re reaction cross sections are given. (6 figs.).

Polymer Photovoltaic Cells with Rhenium Oxide as Anode Interlayer.

Science.gov (United States)

Wei, Jinyu; Bai, Dongdong; Yang, Liying

2015-01-01

The effect of a new transition metal oxide, rhenium oxide (ReO3), on the performance of polymer solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend as buffer layer was investigated. The effect of the thickness of ReO3 layer on electrical characteristics of the polymer solar cells was studied. It is found that insertion of ReO3 interfacial layer results in the decreased performance for P3HT: PCBM based solar cells. In order to further explore the mechanism of the decreasing of the open-circuit voltage (Voc), the X-ray photoelectron spectroscopy (XPS) is used to investigate the ReO3 oxidation states. Kelvin Probe method showed that the work function of the ReO3 is estimated to be 5.13eV after thermal evaporation. The results indicated the fact that a portion of ReO3 decomposed during thermal evaporation process, resulting in the formation of a buffer layer with a lower work function. As a consequence, a higher energy barrier was generated between the ITO and the active layer.

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

Directory of Open Access Journals (Sweden)

I. V. Klenina

2007-12-01

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.

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

Directory of Open Access Journals (Sweden)

Dewi Tristantini

2016-03-01

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: http://dx.doi.org/10.9767/bcrec.11.1.424.84-92

188Rhenium-HEDP in the treatment of pain in bone metastases

International Nuclear Information System (INIS)

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

2001-01-01

Systemic use of radiopharmaceuticals is a recognised alternative method for the treatment of pain in patients with multiple bone metastases. A new option, 188 Re-HEDP is proposed, using generator-obtained 188 Rhenium (β energy = 2.1 MeV, γ 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 metastases 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. (author)

188Rhenium-HEDP in the Treatment of Pain in Bone Metastases

International Nuclear Information System (INIS)

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

1999-01-01

Systemic use of radiopharmaceuticals is a recognized alternative method for the treatment of pain in patients with multiple bone metastasis. A new option, 188 Re-HEDP is proposed, using generator-obtained 188 Rhenium (β energy = 2.1 MeV, γ 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

Why the 18.6 year tide cannot explain the change of sign observed in j2

Directory of Open Access Journals (Sweden)

F. Deleflie

2003-01-01

Full Text Available Recent studies show a change, starting in 1998, in the behavior of the variation of the dynamical flattening of the Earth (J2, supposed to be constant (secular, and mainly due to the post glacial rebound effect. In this paper, we study to what extent this behavior can be correlated or not with the 18.6 year tide: with more than twenty years of tracking data on LAGEOS-1, that is to say more than a period of 18.6 years, this effect can now be separated from the secular variation. We use our theory of mean orbital motion, dedicated to studies of the long period effects on the orbital motion. We build one single arc of LAGEOS-1 from 1980 to 2002, which provides a continuous description of the orbital parameters. This is the great originality of our approach. We focus our attention on the ascending node of LAGEOS-1, and we show that the change observed in j2 cannot be attributed to a statistical error due to a correlation, in short arcs results, between the secular variation of J2 and the 18.6 year tide. The proof is based on the adjustment of amplitudes and phases of the long period tides, and on the shape of the residuals.Key words. secular variation of J2, 18.6 year tide, mean orbital motione

Synthesis, structural characterization and photoluminescence properties of rhenium(I) complexes based on bipyridine derivatives with carbazole moieties.

Science.gov (United States)

Li, Hong-Yan; Wu, Jing; Zhou, Xin-Hui; Kang, Ling-Chen; Li, Dong-Ping; Sui, Yan; Zhou, Yong-Hui; Zheng, You-Xuan; Zuo, Jing-Lin; You, Xiao-Zeng

2009-12-21

Three N,N-bidentate ligands, 5,5'-dibromo-2,2-bipyridine (L1) and two carbazole containing ligands of 5-bromo-5'-carbazolyl-2,2-bipyridine (L2), 5,5'-dicarbazolyl-2,2'-bipyridine (L3), and their corresponding rhenium Re(CO)3Cl(L) complexes (ReL1-ReL3) have been successfully synthesized and characterized by elemental analysis, 1H NMR and IR spectra. Their photophysical properties and thermal analysis, along with the X-ray crystal structure analysis of L3 and complexes ReL1 and ReL3 are also described. In CH2Cl2 solution at room temperature, all complexes display intense absorption bands at ca. 220-350 nm, which can be assigned to spin-allowed intraligand (pi-->pi*) transitions, and the low energy broad bands in the 360-480 nm region are attributed to the metal to ligand charge-transfer d(Re)-->pi* (diimine) (MLCT). The introduction of carbazole moieties improves the MLCT absorption and molar extinction coefficient of these complexes. Upon excitation at the peak maxima, all complexes show strong emissions around 620 nm, which are assigned to d(Re)-->pi* (diimine) MLCT phosphorescence. The photoluminescence lifetime decay of Re(I) complexes were measured and the quantum efficiencies of the rhenium(I) complexes were calculated by using air-equilibrated [Ru(bpy)3]2+ x 2 Cl- aqueous solution as standard (phi(std) = 0.028). The complexes with appended carbazole moieties exhibit enhanced luminescence performances relative to ReL1.

Chemistry and radiochemistry of As, Re and Rh isotopes relevant to radiopharmaceutical applications: high specific activity radionuclides for imaging and treatment.

Science.gov (United States)

Feng, Yutian; Phelps, Tim E; Carroll, Valerie; Gallazzi, Fabio; Sieckman, Gary; Hoffman, Timothy J; Barnes, Charles L; Ketring, Alan R; Hennkens, Heather M; Jurisson, Silvia S

2017-10-31

The chemistry and radiochemistry of high specific activity radioisotopes of arsenic, rhenium and rhodium are reviewed with emphasis on University of Missouri activities over the past several decades, and includes recent results. The nuclear facilities at the University of Missouri (10 MW research reactor and 16.5 MeV GE PETtrace cyclotron) allow research and development into novel theranostic radionuclides. The production, separation, enriched target recovery, radiochemistry, and chelation chemistry of 72,77 As, 186,188 Re and 105 Rh are discussed.

Determination of rhenium traces in river water by Q-ICP-MS and HR-ICP-MS

International Nuclear Information System (INIS)

Uchida, S.; Tagami, K.; Saito, M.

2003-01-01

A simple separation method was applied to determine rhenium in river water using Q-ICP-MS and HR-ICP-MS. Re was concentrated from 420-925 ml river water using a TEVA resin minicolumn. Such extraction using a resin could separate Re from most sample matrices and trace elements. Almost 100% recovery was found throughout the method as determined with radioactive multitracers. The HR-ICP-MS was also used for the direct determination because of its low detection limit for Re (0.007 pg/ml). The Re concentration in the river water samples ranged from 0.9 to 6.5 pg/ml and the three analysis results showed good agreement with each other. (author)

186Os- 187Os systematics of Gorgona Island komatiites: implications for early growth of the inner core

Science.gov (United States)

Brandon, Alan D.; Walker, Richard J.; Puchtel, Igor S.; Becker, Harry; Humayun, Munir; Revillon, Sidonie

2003-02-01

The presence of coupled enrichments in 186Os/ 188Os and 187Os/ 188Os in some mantle-derived materials reflects long-term elevation of Pt/Os and Re/Os relative to the primitive upper mantle. New Os data for the 89 Ma Gorgona Island, Colombia komatiites indicate that these lavas are also variably enriched in 186Os and 187Os, with 186Os/ 188Os ranging between 0.1198397±22 and 0.1198470±38, and with γOs correspondingly ranging from +0.15 to +4.4. These data define a linear trend that converges with the previously reported linear trend generated from data for modern Hawaiian picritic lavas and a sample from the ca. 251 Ma Siberian plume, to a common component with a 186Os/ 188Os of approximately 0.119870 and γOs of +17.5. The convergence of these data to this Os isotopic composition may imply a single ubiquitous source in the Earth's interior that mixes with a variety of different mantle compositions distinguished by variations in γOs. The 187Os- and 186Os-enriched component may have been generated via early crystallization of the solid inner core and consequent increases in Pt/Os and Re/Os in the liquid outer core, with time leading to suprachondritic 186Os/ 188Os and γOs in the outer core. The presence of Os from the outer core in certain portions of the mantle would require a mechanism that could transfer Os from the outer core to the lower mantle, and thence to the surface. If this is the process that generated the isotopic enrichments in the mantle sources of these plume-derived systems, then the current understanding of solid metal-liquid metal partitioning of Pt, Re and Os requires that crystallization of the inner core began prior to 3.5 Ga. Thus, the Os isotopic data reported here provide a new source of data to better constrain the timing of inner core formation, complementing magnetic field paleo-intensity measurements as data sources that constrain models based on secular cooling of the Earth.

Determination of rhenium in biological and environmental samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Kucera, J.; Mizera, J.; Randa, Z.; Byrne, A.R.; Lucanikova, M.

2006-01-01

Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1 M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1 M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng.g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng.g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of approx. 10 ng.g -1 was found. Significantly elevated values of Re, up to 90 ng.g -1 , were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggest possible competition between Re and Tc in the accumulation process. (author)

Calculation and evaluation of the activation cross sections for 187Re(n,2n)186m,gRe reactions

International Nuclear Information System (INIS)

Huang Xiaolong; Lu Hanlin; Zhou Chunmei

1998-01-01

The activation cross sections for 187 Re(n,2n) 186m,g Re reactions are calculated using UNF code. The calculations are in good agreement with the re-evaluated measured data. Finally the excitation function for 187 Re(n,2n) 186m,g Re reactions are evaluated and recommended based on present calculations and evaluated decay data

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-01-18

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.

Biodistribution and dosimetric evaluation of 186Re hydroxy ethylen diphosphate

International Nuclear Information System (INIS)

Noto, M.G.; Manzini, Alberto

1987-01-01

The pharmacokinetics and the dose of radiation absorbed in different body tissues by the administration of 186 Re HEDP (hydroxyethylendiphosphate). The radiation dose in the standard man was established between 5,5 and 25 rad/mCi for red marrow, and red marrow and bone respectively; the radiation dose in metastases would be of 125 rad/mCi. It is concluded that this radiopharmaceutical is suitable for palliative treatment for pain with the mentioned patollogy. (M.E.L.) [es

186 Etude théorique du transport électronique par la simulation ...

African Journals Online (AJOL)

youness

Choukria SAYAH et al. 186. Etude théorique du ... For that we carried out the microscopic simulations, based on the Monte. Carlo method. ... intervalles, piezoelectric as well as the interactions of alloy and on ionized impurities. ..... SAYA et al. 198. [5] - R. W. Hockney, J. W. Eastwood, "Computer simulation using particles",.

Identification of rhenium donors and sulfur vacancy acceptors in layered MoS{sub 2} bulk samples

Energy Technology Data Exchange (ETDEWEB)

Brandão, F. D., E-mail: fdbrand@fisica.ufmg.br; Ribeiro, G. M.; Vaz, P. H.; González, J. C.; Krambrock, K. [Departamento de Física, Universidade Federal de Minas Gerais, CP 702, 30.123-970 Belo Horizonte, MG (Brazil)

2016-06-21

MoS{sub 2} 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 MoS{sub 2} 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 MoS{sub 2} monolayers. By EPR at low temperatures, rhenium donors and sulfur vacancy acceptors are identified as the main impurities in bulk MoS{sub 2} with a corresponding donor concentration of about 10{sup 8–12} defects/cm{sup 2} for MoS{sub 2} 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 × 10{sup 15 }cm{sup −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 × 10{sup 19 }cm{sup −3} and net acceptor concentration of 5 × 10{sup 18 }cm{sup −3} related to sulfur vacancies.

A novel copper(II) coordination at His186 in full-length murine prion protein

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yasuko [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Hiraoka, Wakako [Laboratory of Biophysics, School of Science and Technology, Meiji University, Kawasaki 214-8571 (Japan); Igarashi, Manabu; Ito, Kimihito [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Shimoyama, Yuhei [Soft-Matter Physics Laboratory, Graduate School of Emergent Science, Muroran Institute of Technology, Muroran 050-8585 (Japan); Horiuchi, Motohiro [Laboratory of Prion Diseases, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Yamamori, Tohru; Yasui, Hironobu; Kuwabara, Mikinori [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Inagaki, Fuyuhiko [Laboratory of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812 (Japan); Inanami, Osamu, E-mail: inanami@vetmed.hokudai.ac.jp [Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan)

2010-04-09

To explore Cu(II) ion coordination by His{sup 186} in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP{sup C}.

A novel copper(II) coordination at His186 in full-length murine prion protein

International Nuclear Information System (INIS)

Watanabe, Yasuko; Hiraoka, Wakako; Igarashi, Manabu; Ito, Kimihito; Shimoyama, Yuhei; Horiuchi, Motohiro; Yamamori, Tohru; Yasui, Hironobu; Kuwabara, Mikinori; Inagaki, Fuyuhiko; Inanami, Osamu

2010-01-01

To explore Cu(II) ion coordination by His 186 in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP C .

Hydrodeoxygenation of vicinal OH groups over heterogeneous rhenium catalyst promoted by palladium and ceria support.

Science.gov (United States)

Ota, Nobuhiko; Tamura, Masazumi; Nakagawa, Yoshinao; Okumura, Kazu; Tomishige, Keiichi

2015-02-02

Heterogeneous ReOx-Pd/CeO2 catalyst showed excellent performance for simultaneous hydrodeoxygenation of vicinal OH groups. High yield (>99%), turnover frequency (300 h(-1)), and turnover number (10,000) are achieved in the reaction of 1,4-anhydroerythritol to tetrahydrofuran. This catalyst can be applied to sugar alcohols, and mono-alcohols and diols are obtained in high yields (≥85%) from substrates with even and odd numbers of OH groups, respectively. The high catalytic performance of ReOx-Pd/CeO2 can be assigned to rhenium species with +4 or +5 valence state, and the formation of this species is promoted by H2/Pd and the ceria support. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Science.gov (United States)

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

2016-08-01

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.

Effect of heat-treatment on microstructure and high-temperature deformation behavior of a low rhenium-containing single crystal nickel-based superalloy

International Nuclear Information System (INIS)

Sun, Nairong; Zhang, Lanting; Li, Zhigang; Shan, Aidang

2014-01-01

A low rhenium-containing [001] oriented single crystal nickel-based superalloy with different γ′ morphologies induced by various aging treatments was compressed from room temperature to 1000 °C. All the single crystal samples with different γ′ morphologies exhibit anomalous yield behavior. The sample first aged at 1180 °C has the widest anomalous temperature domain and highest yield strengths. The sample first aged at 1000 °C has the highest anomalous peak stress temperature

A Fluorine-18 Radiolabeling Method Enabled by Rhenium(I) Complexation Circumvents the Requirement of Anhydrous Conditions.

Science.gov (United States)

Klenner, Mitchell A; Pascali, Giancarlo; Zhang, Bo; Sia, Tiffany R; Spare, Lawson K; Krause-Heuer, Anwen M; Aldrich-Wright, Janice R; Greguric, Ivan; Guastella, Adam J; Massi, Massimiliano; Fraser, Benjamin H

2017-05-11

Azeotropic distillation is typically required to achieve fluorine-18 radiolabeling during the production of positron emission tomography (PET) imaging agents. However, this time-consuming process also limits fluorine-18 incorporation, due to radioactive decay of the isotope and its adsorption to the drying vessel. In addressing these limitations, the fluorine-18 radiolabeling of one model rhenium(I) complex is reported here, which is significantly improved under conditions that do not require azeotropic drying. This work could open a route towards the investigation of a simplified metal-mediated late-stage radiofluorination method, which would expand upon the accessibility of new PET and PET-optical probes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shape mixing in sup(184,186)Hg

International Nuclear Information System (INIS)

Baba, C.V.K.

1976-01-01

Recent potential energy calculations on even Hg isotopes have shown that sup(184,186)Hg are possibly deformed with two energy minima one each for oblate (β 2 =-0.14) and prolate (β 2 =0.28) shapes. The quasi-rotational levels in these nuclei have been studied by heavy ion reactions at Berley and Chalk River. The salient features of these studies are: a deviation of the energy levels from a rotational sequence for I + →2 + and 2 + →0 + , E2 transition rates from the rotational value with β 2 =0.28. These features of the spectra are explained on the basis of mixing of bands based on the oblate and prolate shapes. The results of a simple band mixing calculation are presented and they reproduce the observed level spacings and B(E2) values. (author)

Shape coexistence in neutron-deficient Hg isotopes studied via lifetime measurements in $^{184,186}$Hg and two-state mixing calculations

CERN Document Server

Gaffney, L P; Page, R.D.; Grahn, T.; Scheck, M.; Butler, P.A.; Bertone, P.F.; Bree, N.; Carroll, R.J.; Carpenter, M.P.; Chiara, C.J.; Dewald, A.; Filmer, F.; Fransen, C.; Huyse, M.; Janssens, R.V.F.; Joss, D.T.; Julin, R.; Kondev, F.G.; Nieminen, P.; Pakarinen, J.; Rigby, S.V.; Rother, W.; Van Duppen, P.; Watkins, H.V.; Wrzosek-Lipska, K.; Zhu, S.

2014-01-01

The neutron-deficient mercury isotopes, $^{184,186}$Hg, were studied with the Recoil Distance Doppler Shift (RDDS) method using the Gammasphere array and the K\\"oln Plunger device. The Differential Decay Curve Method (DDCM) was employed to determine the lifetimes of the yrast states in $^{184,186}$Hg. An improvement on previously measured values of yrast states up to $8^{+}$ is presented as well as first values for the $9_{3}$ state in $^{184}$Hg and $10^{+}$ state in $^{186}$Hg. $B(E2)$ values are calculated and compared to a two-state mixing model which utilizes the variable moment of inertia (VMI) model, allowing for extraction of spin-dependent mixing strengths and amplitudes.

In-situ field-ion microscope study of the recovery behavior of heavy metal ion-irradiated tungsten, tungsten (rhenium) alloys and molybdenum

International Nuclear Information System (INIS)

Nielsen, C.H.

1977-06-01

Three field ion microscope (FIM) experiments were carried out to study the annealing behavior of heavy ion irradiated tungsten, tungsten (rhenium) alloys and molybdenum. The first experiment dealt with the stage I long-range migration of tungsten self interstitial atoms (SIAs) in high purity tungsten of resistivity ratio, R = 24,000 (R = rho 300 /rho 4 . 2 , where rho 300 and rho 4 . 2 are the room temperature and 0 0 C resistivities). The FIM specimens were irradiated in situ at 18 K with 30 keV W + ions to an average dose of 5 x 10 12 ions cm -2 and subsequently examined by the pulsed-field evaporation technique. The second experiment dealt with the phenomenon of impurity atom trapping of SIAs during long-range migration. It was shown that rhenium atoms in a tungsten matrix tend to capture tungsten SIAs and remain bound up to temperatures as high as 390 K. The final experiment was concerned with the low temperature annealing kinetics of irradiated molybdenum. High purity molybdenum of resistivity ratio R = 5700 was irradiated at 10 K with 30 keV Mo + ions to a dose of approximately 5 x 10 12 ions cm -2 . The results indicated that the electric field has only a minimal effect on the SIA annealing kinetics. This tends to strengthen the contention that the molybdenum SIA becomes mobile at 32 K

A randomised, phase II study of repeated rhenium-188-HEDP combined with docetaxel and prednisone versus docetaxel and prednisone alone in castration-resistant prostate cancer (CRPC) metastatic to bone; the Taxium II trial

Energy Technology Data Exchange (ETDEWEB)

Dodewaard-de Jong, Joyce M. van [VU University Medical Centre, Department of Medical Oncology, Amsterdam (Netherlands); Meander Medical Centre, Department of Medical Oncology, Amersfoort (Netherlands); Klerk, John M.H. de [Meander Medical Centre, Department of Nuclear Medicine, Amersfoort (Netherlands); Bloemendal, Haiko J. [Meander Medical Centre, Department of Medical Oncology, Amersfoort (Netherlands); University Medical Centre Utrecht, Department of Medical Oncology, Utrecht (Netherlands); Oprea-Lager, Daniela E.; Hoekstra, Otto S. [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Berg, H.P. van den [Tergooi Medical Hospital, Department of Medical Oncology, Hilversum (Netherlands); Los, Maartje [St Antonius Hospital Utrecht, Department of Medical Oncology, Utrecht (Netherlands); Beeker, Aart [Spaarne Gasthuis, Department of Medical Oncology, Hoofddorp (Netherlands); Jonker, Marianne A. [VU University Medical Centre, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); O' Sullivan, Joe M. [Queen' s University Belfast, Centre for Cancer Research and Cell Biology, Belfast, Northern Ireland (United Kingdom); Verheul, Henk M.W.; Eertwegh, Alfons J.M. van den [VU University Medical Centre, Department of Medical Oncology, Amsterdam (Netherlands)

2017-08-15

Rhenium-188-HEDP is a beta-emitting radiopharmaceutical used for palliation of metastatic bone pain. We investigated whether the addition of rhenium-188-HEDP to docetaxel/prednisone improved efficacy of chemotherapy in patients with CRPC. Patients with progressive CRPC and osteoblastic bone metastases were randomised for first-line docetaxel 75 mg/m{sup 2} 3-weekly plus prednisone with or without 2 injections of rhenium-188-HEDP after the third (40 MBq/kg) and after the sixth (20 MBq/kg) cycle of docetaxel. Primary endpoint was progression-free survival (PFS), defined as either PSA, radiographic or clinical progression. Patients were stratified by extent of bone metastases and hospital. Forty-two patients were randomised for standard treatment and 46 patients for combination therapy. Median number of cycles of docetaxel was 9 in the control group and 8 in the experimental group. Median follow-up was 18.4 months. Two patients from the experimental group did not start treatment after randomisation. In the intention to treat analysis no differences in PFS, survival and PSA became apparent between the two groups. In an exploratory per-protocol analysis median overall survival was significantly longer in the experimental group (33.8 months (95%CI 31.75-35.85)) than in the control group (21.0 months (95%CI 13.61-28.39); p 0.012). Also median PFS in patients with a baseline phosphatase >220U/L was significantly better with combination treatment (9.0 months (95%CI 3.92-14.08) versus 6.2 months (95%CI 3.08-9.32); log rank p 0.005). As expected, thrombocytopenia (grade I/II) was reported more frequently in the experimental group (25% versus 0%). Combined treatment with rhenium-188-HEDP and docetaxel did not prolong PFS in patients with CRPC. The observed survival benefit in the per-protocol analysis warrants further studies in the combined treatment of chemotherapy and radiopharmaceuticals. (orig.)

Biodistribution, pharmacokinetic, and imaging studies with 186Re-labeled NR-LU-10 whole antibody in LS174T colonic tumor-bearing mice

International Nuclear Information System (INIS)

Goldrosen, M.H.; Biddle, W.C.; Pancook, J.; Bakshi, S.; Vanderheyden, J.L.; Fritzberg, A.R.; Morgan, A.C. Jr.; Foon, K.A.

1990-01-01

Biodistribution, pharmacokinetic, and radioimaging studies were performed with 186Re-labeled NR-LU-10 whole antibody in athymic nude mice bearing the LS174T tumor growing either s.c. or in an experimental hepatic metastasis model. NR-LU-10 is an IgG2b murine monoclonal antibody (MAb) that reacts with virtually all human tumors of epithelial origin. NR-BC-1, a IgG2b murine MAb that reacts with normal human B-cell and B malignancies, was used as an isotype-matched control. These MAbs were radiolabeled with 186Re by a preformed chelate approach by using the triamide thiolate ligand system. 186Re-labeled NR-LU-10 (50 microCi) was injected into nude mice bearing LS174T tumors growing s.c. Biodistribution studies revealed that the LS174T tumor retained the highest concentration of 186Re-labeled NR-LU-10 at day 6. The tumor:blood ratio ranged from 0.1:1 to 10.8:1 by day 6, the last day of analysis. In contrast the tumor:blood ratio of 186Re-labeled NR-BC-1, the isotype-matched MAb control, was 1:1 on day 6. Pharmacokinetic analysis indicated that the t1/2 beta of NR-LU-10 for blood and other tissues ranged from 21 to 25 h, while the t1/2 beta for the LS174T tumor averaged 52 h. The area under the curve for tumor compared to blood was 2.8- to 5.7-fold higher than the area under the curve for all other tissues and organs. The mean residence time for NR-LU-10 in blood and all other organs ranged from 23 to 26 h, while the mean residence time for NR-LU-10 in the LS174T tumor was 72 h. Scintigraphic images revealed selective uptake of the 186Re-labeled NR-LU-10, but not of the 186Re-labeled NR-BC-1, at the LS174T tumor site. Studies in an experimental model of hepatic metastasis revealed a similar selective pattern of 186Re-labeled NR-LU-10 accumulation. Scintigraphic images of the LS174T tumor growing within the athymic nude mouse liver were obtained

Obliquity Variations of Habitable Zone Planets Kepler-62f and Kepler-186f

Science.gov (United States)

Shan, Yutong; Li, Gongjie

2018-06-01

Obliquity variability could play an important role in the climate and habitability of a planet. Orbital modulations caused by planetary companions and the planet’s spin axis precession due to the torque from the host star may lead to resonant interactions and cause large-amplitude obliquity variability. Here we consider the spin axis dynamics of Kepler-62f and Kepler-186f, both of which reside in the habitable zone around their host stars. Using N-body simulations and secular numerical integrations, we describe their obliquity evolution for particular realizations of the planetary systems. We then use a generalized analytic framework to characterize regions in parameter space where the obliquity is variable with large amplitude. We find that the locations of variability are fine-tuned over the planetary properties and system architecture in the lower-obliquity regimes (≲40°). As an example, assuming a rotation period of 24 hr, the obliquities of both Kepler-62f and Kepler-186f are stable below ∼40°, whereas the high-obliquity regions (60°–90°) allow moderate variabilities. However, for some other rotation periods of Kepler-62f or Kepler-186f, the lower-obliquity regions could become more variable owing to resonant interactions. Even small deviations from coplanarity (e.g., mutual inclinations ∼3°) could stir peak-to-peak obliquity variations up to ∼20°. Undetected planetary companions and/or the existence of a satellite could also destabilize the low-obliquity regions. In all cases, the high-obliquity region allows for moderate variations, and all obliquities corresponding to retrograde motion (i.e., >90°) are stable.

Chemical Abundances of M-Dwarfs from the Apogee Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186

Energy Technology Data Exchange (ETDEWEB)

Souto, D.; Cunha, K. [Observatório Nacional, Rua General José Cristino, 77, 20921-400 São Cristóvão, Rio de Janeiro, RJ (Brazil); García-Hernández, D. A.; Zamora, O.; Prieto, C. Allende; Jönsson, H.; Pérez, A. E. García [Instituto de Astrofísica de Canarias (IAC), Vía Lactea S/N, E-38205, La Laguna, Tenerife (Spain); Smith, V. V. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Mahadevan, S. [Department of Astronomy and Astrophysics, The Pennsylvania State University (United States); Blake, C. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Johnson, J. A.; Pinsonneault, M. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Holtzman, J. [New Mexico State University, Las Cruces, NM 88003 (United States); Majewski, S. R.; Sobeck, J. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Shetrone, M. [University of Texas at Austin, McDonald Observatory (United States); Teske, J. [Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015 (United States); Nidever, D. [Department of Astronomy, University of Michigan, Ann Arbor, MI, 48104 (United States); Schiavon, R. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF (United Kingdom); and others

2017-02-01

We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution ( R ∼ 22,500) H -band spectra from the SDSS-IV–APOGEE survey. Chemical abundances of 13 elements—C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe—are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H{sub 2}O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: [Fe/H]{sub Kepler-138} = −0.09 ± 0.09 dex and [Fe/H]{sub Kepler-186} = −0.08 ± 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1–0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55±0.10 for Kepler-138 and 0.52±0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced [Si/Fe] ratio.

Radiochemical study of Re/W adsorption behavior on a strongly basic anion exchange resin

International Nuclear Information System (INIS)

Gott, Matthew D.; Missouri Univ., Columbia, MO; Ballard, Beau D.; Redman, Lindsay N.

2014-01-01

Rhenium-186g is a radionuclide with a high potential for therapeutic applications. It emits therapeutic β - particles accompanied by low energy γ-rays, which allows for in-vivo tracking of the radiolabeled compound and dosimetry estimates. The current reactor production pathway 185 Re(n,γ) 186g Re produces low specific activity 186g Re, thereby limiting its therapeutic application. Work is underway to develop an accelerator-based, charged particle induced production method for high specific activity 186g Re from targets of enriched 186 W. To optimize the chemical 186g Re recovery method, batch studies have been performed to characterize the adsorption behavior of Re and W on a strongly basic anion exchange resin. An in-depth physicochemical profile was developed for the interaction of Re with resin material, which showed the reaction to be endothermic and spontaneous. Basic (NaOH) and acidic (HNO 3 ) matrices were used to determine the equilibrium distribution coefficients for Re and W. The resin exhibits the best affinity for Re at slightly basic conditions and little affinity above moderately acidic concentrations. Tungsten has low affinity for the resin above moderately basic concentrations. A study was performed to examine the effect of W concentration on Re adsorption, which showed that even a high ionic WO 4 2- strength of up to 1.9 mol kg -1 does not significantly compromise ReO 4 - retention on the resin. (orig.)

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

International Nuclear Information System (INIS)

Mullice, L.A.; Buurma, N.J.; Pope, S.J.A.; Laye, R.H.; Harding, L.P.

2008-01-01

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) 3 core. The ligands L 1 1-[bis(pyridine-2-yl-methyl)amino]methyl-pyrene and L 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 1 H NMR, MS, IR and UV-Vis studies. X-Ray crystallographic data were obtained for fac-{Re(CO) 3 (L 1 )}(BF 4 ), C 34 H 26 BF 4 N 4 O 3 Re: monoclinic, P2(1)/c, a 18.327(2) Angstroms, α = 90.00 degrees, b 14.1537(14) Angstroms, β96.263(6) degrees, c = 23.511(3) Angstroms, γ 90.00 Angstroms, 6062.4(11) (Angstroms) 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-{Re(CO) 3 (L 1 )}(BF 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-{Re(CO) 3 (L 1 )}(BF 4 ) were undertaken and revealed that fac-{Re(CO) 3 (L 1 )}(BF 4 ) binding to fish sperm DNA (binding constant 1.5 ± 0.2 * 10 5 M -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 -1 ) also agrees favourably with values as typically found for intercalators. (authors)

Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic

Science.gov (United States)

Shim, Jaewoo; Oh, Seyong; Kang, Dong-Ho; Jo, Seo-Hyeon; Ali, Muhammad Hasnain; Choi, Woo-Young; Heo, Keun; Jeon, Jaeho; Lee, Sungjoo; Kim, Minwoo; Song, Young Jae; Park, Jin-Hong

2016-01-01

Recently, negative differential resistance devices have attracted considerable attention due to their folded current–voltage characteristic, which presents multiple threshold voltage values. Because of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative differential resistance device based on a phosphorene/rhenium disulfide (BP/ReS2) heterojunction that is formed by type-III broken-gap band alignment, showing high peak-to-valley current ratio values of 4.2 and 6.9 at room temperature and 180 K, respectively. Also, the carrier transport mechanism of the BP/ReS2 negative differential resistance device is investigated in detail by analysing the tunnelling and diffusion currents at various temperatures with the proposed analytic negative differential resistance device model. Finally, we demonstrate a ternary inverter as a multi-valued logic application. This study of a two-dimensional material heterojunction is a step forward toward future multi-valued logic device research. PMID:27819264

Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic

Science.gov (United States)

Shim, Jaewoo; Oh, Seyong; Kang, Dong-Ho; Jo, Seo-Hyeon; Ali, Muhammad Hasnain; Choi, Woo-Young; Heo, Keun; Jeon, Jaeho; Lee, Sungjoo; Kim, Minwoo; Song, Young Jae; Park, Jin-Hong

2016-11-01

Recently, negative differential resistance devices have attracted considerable attention due to their folded current-voltage characteristic, which presents multiple threshold voltage values. Because of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative differential resistance device based on a phosphorene/rhenium disulfide (BP/ReS2) heterojunction that is formed by type-III broken-gap band alignment, showing high peak-to-valley current ratio values of 4.2 and 6.9 at room temperature and 180 K, respectively. Also, the carrier transport mechanism of the BP/ReS2 negative differential resistance device is investigated in detail by analysing the tunnelling and diffusion currents at various temperatures with the proposed analytic negative differential resistance device model. Finally, we demonstrate a ternary inverter as a multi-valued logic application. This study of a two-dimensional material heterojunction is a step forward toward future multi-valued logic device research.

Thermal transformations of oxohalide complexes of rhenium(5) and molybdenum(5) with diazo-18-crown-6 in solid phase

International Nuclear Information System (INIS)

Ashurova, N.Kh.; Yakubov, K.G.

1992-01-01

Methods for synthesis and separation in solid state of the rhenium(5) and molybdenum(5) onium complexes with diaza-18-crown-6(L), the content of which according to the data of elementary analysis, IRS in the close and remote areas, thermogravimetry, conductometry and potentiometry corresponds to the (H 2 L)[EOX 5 ], where E = Re, Mo; X = Cl - , Br - . Thermotransformation of onium compounds is studied by methods of thermal methods (TG-DTG-DTA combined study). Their avility to be affected by solid-phase dehydrohalogenization, e.i. anderson regrouping. The thermolysis products, corresponding to the general formula (EOLX 3 ), are separated and studied

Curcumin Promoted the Apoptosis of Cisplain-resistant Human Lung Carcinoma Cells A549/DDP through Down-regulating miR-186*

Directory of Open Access Journals (Sweden)

Jian ZHANG

2010-04-01

Full Text Available Background and objective Curcumin, a natural compound, is derived from the rthizom of Curcuma longa. In vitro and in vivo preclinical studies have shown its anti-inflammatory, antioxidant, anticancer activities and so on. miR-186*, which was found by microarray technology, was highly expressed in lung carcinoma cells A549/DDP. The aim of this study is to illustrate whether Curcumin could promote the apoptosis of A549/DDP cells through regulating the expression of miR-186*. Methods An oligonucleotide microarray chip was used to profile microRNA (miRNA expressions in A549/DDP cells treated with and without Curcumin. The significantly differentially expressed miRNA, which was selected from microarray chip, validated by quantitative real-time PCR. Ultimately, the remarkably expressed miRNA modulated the apoptosis assaying by flow cytometry expriments and the survival rate was measured by MTT method. Results The microarray chip results demonstrated: Curcumin altered the expression level of miRNAs compared with untreated control in A549/DDP cell line, miR-186* was significantly down-regulated after Curcumin treatment, which confirmed by quantitative real-time PCR. Downregulation of miR-186* expression by curcumin elevated the apoptosis, and the survival rate of A549/DDP cells decreased; but up-regulation of miR-186* expression by transfection its mimics restrained the apoptosis, the survival rate of A549/DDP cells increased, which were assayed by flow cytometry expriments and MTT method. Conclusion Modulation of miRNAs expression may be an important mechanism underlying the biological roles of Curcumin.

Eradication of colon cancer cells before tumour formation in the peritoneal cavity of mice treated with intraperitoneal Re-186 radioimmunotherapy

International Nuclear Information System (INIS)

Kinuya, S.; Hiramatsu, T.; Michigishi, T.

2006-01-01

A treatment adjuvant to surgical resection of the primary lesion has been proven to be beneficial in improving the prognosis of patients with high risks of peritoneal dissemination of colon cancer. This study was performed to determine the comparative efficacy of intraperitoneal radioimmunotherapy (RIT) using Re-186 or I-131 labeled murine antibodies in the extermination of cancer cells. A murine anti-colorectal IgG1, A7 monoclonal antibody, was radio-labeled either with I-131 (by the chloramine-T method) or Re-186 (by the MAG3 pre-chelated method). A total number of 16 mice were subjected to RIT with Re-186 A7 (N=8) or I-131 A7 (N=8) at equitoxic doses in Balb/c bu/nu mice 10 min after intraperitoneal injection of LS180 human colon cancer cells. A third group of mice were subjected to chemotherapy with 5-fluorouracil at 30 mg/kg for 4 consecutive days following the intraperitoneal injection of the same LS180 human colon cancer cells. There were 19 mice in the control group who were not subjected to any form of therapy. The results revealed that the mean survival of mice in the control (N-19), I-131 A7 RIT (N=8) and Chemotherapy (N=6) groups were 33.8 ± 1.0, 80.1 ± 2.5 and 49.3 ± 5.3 days respectively. The eight mice who were subjected to Re-186 A7 RIT showed much better survival compared to the other groups. Two of the eight mice from this group died at 105 and 111 days following Re-186 A7 RIT. Other six mice were sacrificed at 172 days, and autopsy revealed no macroscopic peritoneal tumor growth. Based on this pilot study we concluded that individual tumor cells in the peritoneal cavity would be effectively exterminated by intraperitoneal RIT with Re-186 A7. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Goehler, Thomas

2016-06-17

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

Thermal decomposition of rhenium (5) complexes with 1,2,4-triazole. Termicheskoe razlozhenie kompleksov reniya (5) s 1,2,4-triazolom

Energy Technology Data Exchange (ETDEWEB)

Amindzhanov, A A; Gagieva, S Ch; Kotegov, K V [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

1991-01-01

Processes of thermal decomposition of rhenium (5) complexes with 1,2,4-triazole were studied. Thermolysis products were identified on the basis of data of the element analysis, IR spectra, conductometry and other methods. It is ascertained that at the first stage of thermolysis of hydroxyl-containing monomer complexes removal of water molecules occurs, and at the second one - dimerization process with formation of Re-O-Re group. It is shown that the nature of halide ion practically does not affect the temperature of the start of intensive thermal decomposition of the complexes.

POX 186: A Dwarf Galaxy in the Process of Formation?

Science.gov (United States)

Corbin, Michael R.; Vacca, William D.

2002-12-01

We present deep U-, V-, and I-band images of the ``ultracompact'' blue dwarf galaxy POX 186 obtained with the Planetary Camera 2 of the Hubble Space Telescope. We have also obtained a near-ultraviolet spectrum of the object with the Space Telescope Imaging Spectrograph and combine this with a new ground-based optical spectrum. The images confirm the galaxy to be extremely small, with a maximum extent of only 300 pc, a luminosity of ~10-4L*, and an estimated mass of ~107 Msolar. Its morphology is highly asymmetric, with a tail of material on its western side that may be tidal in origin. The U-band image shows this tail to be part of a stream of material in which stars have recently formed. Most of the star formation in the galaxy is, however, concentrated in a central, compact (d~10-15 pc) star cluster. We estimate this cluster to have a total mass of ~105 Msolar, to be forming stars at a rate of less than 0.05 yr-1, and to have a maximum age of a few million years. The outer regions of the galaxy are significantly redder than the cluster, with V-I colors consistent with a population dominated by K and M stars. From our analysis of the optical spectrum we find the galaxy to have a metallicity Z~=0.06 Zsolar and to contain a significant amount of internal dust [E(B-V)~=0.28] both values agree with previous estimates. While these results rule out earlier speculation that POX 186 is a protogalaxy, its morphology, mass, and active star formation suggest that it represents a recent (within ~108 yr) collision between two clumps of stars of subgalactic size (~100 pc). POX 186 may thus be a very small dwarf galaxy that, dynamically speaking, is still in the process of formation. This interpretation is supported by the fact that it resides in a void, so its morphology cannot be explained as the result of an encounter with a more massive galaxy. Clumps of stars this small may represent the building blocks required by hierarchical models of galaxy formation, and these results

12 CFR 303.186 - Exemptions from insurance requirements for a state branch of a foreign bank.

Science.gov (United States)

2010-01-01

... availability of credit to all sectors of the United States economy, including the international trade finance... CORPORATION PROCEDURE AND RULES OF PRACTICE FILING PROCEDURES International Banking § 303.186 Exemptions from...

Laser-induced breakdown spectroscopy measurement of a small fraction of rhenium in bulk tungsten

Science.gov (United States)

Nishijima, D.; Ueda, Y.; Doerner, R. P.; Baldwin, M. J.; Ibano, K.

2018-03-01

Laser-induced breakdown spectroscopy (LIBS) of bulk rhenium (Re) and tungsten (W)-Re alloy has been performed using a Q-switched Nd:YAG laser (wavelength = 1064 nm, pulse width ∼4-6 ns, laser energy = 115 mJ). It is found that the electron temperature, Te, of laser-induced Re plasma is lower than that of W plasma, and that Te of W-Re plasma is in between Re and W plasmas. This indicates that material properties affect Te in a laser-induced plasma. For analysis of W-3.3%Re alloy, only the strongest visible Re I 488.9 nm line is found to be used because of the strong enough intensity without contamination with W lines. Using the calibration-free LIBS method, the atomic fraction of Re, cRe, is evaluated as a function of the ambient Ar gas pressure, PAr. At PAr 10 Torr due to spectral overlapping of the Re I 488.9 nm line by an Ar II 488.9 nm line.

Prototype commercial electrooxidation cell for the recovery of molybdenum and rhenium from molybdenite concentrates

International Nuclear Information System (INIS)

Scheiner, B.J.; Pool, D.L.; Lindstrom, R.E.; McCleland, G.E.

1979-01-01

As part of the goal to maximize minerals and metals recovery from primary domestic resources, design factors associated with minimizing current leakage in bipolar cell configurations were studied as a means of improving the efficiency of bipolar electrooxidation cells. Initial studies that were conducted in a small bipolar cell operating at 140 to 145 volts and 15.4 A indicated how design factors could be employed to minimize current leakage around adjacent electrodes during cell operation. Based on these results, a 40-electrode, 108-kVA prototype of an industrial-sized cell was constructed and tested for extracting metal values from offgrade molybdenite concentrates. The feasibility of recovering molybdenum and rhenium from the oxidized pulp also was determined. Feed to the process sequence consisted of flotation concentrates containing 16 to 35% Mo as molybdenite and 6 to 15% Cu. Electrooxidation in the prototype cell results in 84 to 97% Mo and Re extraction with a corresponding energy consumption of 9 to 13 kWh/lb Mo extracted

The Long Non-Coding RNA XIST Controls Non-Small Cell Lung Cancer Proliferation and Invasion by Modulating miR-186-5p

Directory of Open Access Journals (Sweden)

Haoyou Wang

2017-04-01

Full Text Available Background/Aims: Long non-coding RNAs (lncRNAs are key players in the development and progression of human cancers. The lncRNA XIST (X-inactive specific transcript has been shown to be upregulated in human non-small cell lung cancer (NSCLC; however, its role and molecular mechanisms in NSCLC cell progression remain unclear. Methods: qRT-PCR was conducted to assess the expression of XIST and miR-186. Cell proliferation was detected using MTT assay. Cell invasion and migration were evaluated using transwell assay. Cell cycle distribution and apoptosis rates were analyzed by flow cytometry. Luciferase reporter assay was used to identify the direct regulation of XIST and miR-186. A RNA immunoprecipitation was used to analyze whether XIST was associated with the RNA-induced silencing complex (RISC. Results: We confirmed that XIST was upregulated in NSCLC cell lines and tissues. Functionally, XIST knockdown inhibited cancer cell proliferation and invasion, and induced apoptosis in vitro, and suppressed subcutaneous tumor growth in vivo. Mechanistic investigations revealed a reciprocal repressive interaction between XIST and miR-186-5p. Furthermore, we showed that miR-186-5p has a binding site for XIST. Our data also indicated that XIST and miR-186-5p are likely in the same RNA induced silencing complex. Conclusion: Together, our data revealed that XIST knockdown confers suppressive function in NSCLC and XIST may be a novel therapeutic marker in this disease.

78 FR 43145 - Announcing Approval of Federal Information Processing Standard 186-4, Digital Signature Standard

Science.gov (United States)

2013-07-19

...-01] Announcing Approval of Federal Information Processing Standard 186-4, Digital Signature Standard.... SUMMARY: This notice announces the Secretary of Commerce's approval of Federal Information Processing... changes are effective on July 19, 2013. FOR FURTHER INFORMATION CONTACT: Elaine Barker (301) 975-2911...

Radiochemical study of Re/W adsorption behavior on a strongly basic anion exchange resin

Energy Technology Data Exchange (ETDEWEB)

Gott, Matthew D. [Los Alamos National Laboratory, Los Alamos, NM (United States). Chemistry Div.; Missouri Univ., Columbia, MO (United States). Dept. of Chemistry; Ballard, Beau D.; Redman, Lindsay N. [Los Alamos National Laboratory, Los Alamos, NM (United States). Chemistry Div.; and others

2014-07-01

Rhenium-186g is a radionuclide with a high potential for therapeutic applications. It emits therapeutic β{sup -} particles accompanied by low energy γ-rays, which allows for in-vivo tracking of the radiolabeled compound and dosimetry estimates. The current reactor production pathway {sup 185}Re(n,γ){sup 186g}Re produces low specific activity {sup 186g}Re, thereby limiting its therapeutic application. Work is underway to develop an accelerator-based, charged particle induced production method for high specific activity {sup 186g}Re from targets of enriched {sup 186}W. To optimize the chemical {sup 186g}Re recovery method, batch studies have been performed to characterize the adsorption behavior of Re and W on a strongly basic anion exchange resin. An in-depth physicochemical profile was developed for the interaction of Re with resin material, which showed the reaction to be endothermic and spontaneous. Basic (NaOH) and acidic (HNO{sub 3}) matrices were used to determine the equilibrium distribution coefficients for Re and W. The resin exhibits the best affinity for Re at slightly basic conditions and little affinity above moderately acidic concentrations. Tungsten has low affinity for the resin above moderately basic concentrations. A study was performed to examine the effect of W concentration on Re adsorption, which showed that even a high ionic WO{sub 4}{sup 2-} strength of up to 1.9 mol kg{sup -1} does not significantly compromise ReO{sub 4}{sup -} retention on the resin. (orig.)

AdVEGF-B186 and AdVEGF-DΔNΔC induce angiogenesis and increase perfusion in porcine myocardium.

Science.gov (United States)

Nurro, Jussi; Halonen, Paavo J; Kuivanen, Antti; Tarkia, Miikka; Saraste, Antti; Honkonen, Krista; Lähteenvuo, Johanna; Rissanen, Tuomas T; Knuuti, Juhani; Ylä-Herttuala, Seppo

2016-11-01

Coronary heart disease remains a significant clinical problem, and new therapies are needed especially for patients with refractory angina for whom the current therapies do not provide sufficient relief. The aim of this study was to find out if angiogenic gene therapy using new members of the vascular endothelial growth factor (VEGF) family, VEGF-B 186 and VEGF-D ΔNΔC , increase myocardial perfusion as measured by the positron emission tomography (PET) 15 O-imaging, and whether there would be coronary steal effect to the contralateral side. Furthermore, safety of intramyocardial angiogenic adenoviral gene transfer was evaluated. Intramyocardial adenoviral (Ad) VEGF-B 186 or AdVEGF-D ΔNΔC gene transfers were given endovascularly into the porcine posterolateral wall of the left ventricle (n=34). Six days later, PET 15 O-imaging for myocardial perfusion and coronary angiography were performed. AdVEGF-B 186 and AdVEGF-D ΔNΔC induced angiogenesis and increased total microvascular area 1.8-fold (95% CI 0.2 to 3.5) and 2.8-fold (95% CI 1.4 to 4.3), respectively. At rest, perfusion was maintained at normal levels, but at stress, relative perfusion was increased 1.4-fold (95% CI 1.1 to 1.7) for AdVEGF-B 186 and 1.3-fold (95% CI 1.0 to 1.7) for AdVEGF-D ΔNΔC , without causing coronary steal effect in the control area. The therapy was well tolerated and did not lead to any significant changes in laboratory safety parameters. Both AdVEGF-B 186 and AdVEGF-D ΔNΔC gene transfers induced efficient angiogenesis in the myocardium resulting in an increased myocardial perfusion measured by PET. Importantly, local perfusion increase did not induce any coronary steal effect. As such, both treatments seem suitable new candidates for the induction of therapeutic angiogenesis for the treatment of refractory angina. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

SPS Fabrication of Tungsten-Rhenium Alloys in Support of NTR Fuels Development

International Nuclear Information System (INIS)

Webb, Jonathan A.; Charit, Indrajit; Sparks, Cory; Butt, Darryl P.; Frary, Megan; Carroll, Mark

2011-01-01

Tungsten metal slugs were fabricated via Spark Plasma Sintering (SPS) of powdered metals at temperatures ranging from 1575 K to 1975 K and hold times of 5 minutes to 30 minutes, using powders with an average diameter of 7.8 ?m. Sintered tungsten specimens were found to have relative densities ranging from 83 % to 94 % of the theoretical density for tungsten. Consolidated specimens were also tested for their Vickers Hardness Number (VHN), which was fitted as a function of relative density; the fully consolidated VHN was extrapolated to be 381.45 kg/mm2. Concurrently, tungsten and rhenium powders with average respective diameters of 0.5 ?m and 13.3 ?m were pre-processed either by High-Energy-Ball-Milling (HEBM) or by homogeneous mixing to yield W-25at.%Re mixtures. The powder batches were sintered at temperatures of 1975 K and 2175 K for hold times ranging from 0 minutes to 60 minutes yielding relative densities ranging from 94% to 97%. The combination of HEBM and sintering showed a significant decrease in the inter-metallic phases compared to that of the homogenous mixing and sintering.

Rhenium 188 labelling of peptide conjugates

International Nuclear Information System (INIS)

Melendez-Alafort, Laura

2001-01-01

Many human tumours express high levels, of somatostatin receptors. In order to make possible a radiotherapeutic treatment of this kind for tumour a series of somatostatin analogues that can tightly chelate beta emitting isotopes have been developed in recent years. The work carried out for this thesis has been aimed towards development of a new therapeutic radiopharmaceutical for treatment of somatostatin receptor positive tumours. The first chapters describe work with technetium-99m to establish the labelling and analytical conditions for a somatostatin analogue, [Tyr 3 ]-octreotide (TOC), as a precursor to undertaking labelling studies with the beta emitter rhenium-188. 6-Hydrazinopyridine-3-carboxylic acid (HYNIC) was conjugated to TOC and labelled with 99m using different coligands. Then the stability, receptor binding and biodistribution of each complex were assessed. 99m Tc-HYNIC-TOC using EDDA as coligand showed the best characteristics, and was superior for tumour imaging in humans than the commercially available 111 In-DTPA-octreotide. The conditions for labelling the HYNIC-TOC conjugate with 188 Re were then optimised using tricine as a co-ligand. A labelling yield of ∼80% was achieved. After purification however, the stability of the complex was low. The use of other coligand systems which had proved useful for 99m Tc labelling was explored, but yields were very poor. Other chelators such as diethylenetriamine pentaacetic acid (DTPA), dimercaptosuccinic acid (DMSA) and mercaptoacetyltriglycine (MAG 3 ) were studied as potential co-ligand agents to label the HYNIC-TOC conjugate with 188 Re but, again low yields of the labelled peptide complexes were achieved. A novel 188 Re-HYNIC complex was prepared in high yields using N-N-disubstituted dithiocarbamates as coligands. However to date, the specific activities achieved with this system are relatively low. The use of the [ 99m Tc(CO) 3 (H 2 O) 3 ] complex to label the HYNIC-TOC conjugate was investigated

Predictive implications of bone turnover markers after palliative treatment with 186Re-HEDP in hormone-refractory prostate cancer patients with painful osseous metastases

International Nuclear Information System (INIS)

Zafeirakis, Athanasios; Papatheodorou, Georgios; Arhontakis, Athanasios; Gouliamos, Athanasios; Vlahos, Lambros; Limouris, Georgios S.

2010-01-01

To prospectively evaluate the predictive value of various bone formation and resorption markers in patients with bone metastases from prostate cancer after palliative treatment with 186 Re-1,1-hydroxyethylidene diphosphonate ( 186 Re-HEDP). Included in the study were 36 men with prostate cancer, suffering from painful osseous metastases and treated with 186 Re-HEDP. None had received any treatment that would have interfered with bone metabolism before 186 Re-HEDP treatment or throughout the follow-up period. For each patient, pretreatment and posttreatment serum levels of osteocalcin (OC), bone alkaline phosphatase (BALP), aminoterminal (PINP) and carboxyterminal (PICP) propeptides of type I collagen, amino-terminal (NTx) and carboxyterminal (CTx) telopeptides of type I collagen and their combinations were compared with the level and duration of pain response to radionuclide treatment. Pain response was correlated only with pretreatment ΝΤx/PINP, PICP/PINP and NTx/CTx ratios and posttreatment decrease in baseline NTx and PICP values (p=0.0025-0.035). According to multivariate and ROC analyses, the best marker-derived predictors of better and longer duration of response to 186 Re-HEDP treatment were a posttreatment decrease in NTx of ≥20% (RR=3.44, p=0.0005) and a pretreatment NTx/PINP ratio of ≥1.2 (RR=3.04, p=0.036) NTx, a potent collagenous marker of bone resorption, along with the novel NTx/PINP ratio provide useful cut-off values for identifying a group of patients suffering from painful osseous metastases from hormone-refractory prostatic carcinoma who do not respond to palliative treatment with 186 Re-HEDP. This information could help avoid an inefficient and expensive radionuclide treatment. Also, in the cohort of patients who will eventually undergo such treatment, the medium-term posttreatment changes in NTx offer valuable predictive information regarding long-term palliative response. (orig.)

Design of a formulation for the preparation of {sup 99m} Tc-(V)-Dmsa and {sup 186} Re-(V)-Dmsa; Diseno de una formulacion para la obtencion de {sup 99m} Tc-(V)-DMSA y {sup 186} Re-(V)-DMSA

Energy Technology Data Exchange (ETDEWEB)

Marquez L, M B [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

1998-06-01

Among the radiopharmaceuticals used for neoplasia, we can find the dimercaptosuccinic acid (Dmsa) labelled with {sup 99m} Tc and {sup 186/188} Re. Initially, the {sup 99m} Tc-(III)-Dmsa was employed as a renal image agent. Nevertheless, when it is prepared into a basic solution, the {sup 99m} Tc-(V)-Dmsa complex is produced in high yield being cumulated by cells with a great metabolic activity. This property makes it a useful radiopharmaceutical for the detection of medullary thyroid carcinoma (MTC), soft-tissue tumors and other head and neck tumors. On the other hand, the renewed interest in {beta} - emitting radionuclides, suggests that the {sup 186} Re-(V)-Dmsa complex could be used as antineoplastic agent in therapy. However, the techniques reported for the preparation of these compounds lack of stability studies and they are still in process of investigation, compromising to continue on the development of the radiopharmaceuticals by introducing new possibilities for better products already known, obtaining in this way, the approximation to the ideal radiopharmaceutical. The objective of this work is to design a freeze dried kit formulation for the instant preparation of {sup 99m} Tc-(V)-Dmsa and {sup 186} Re-(V)-Dmsa complexes useful in the diagnostic and therapy of soft-tissue tumors and other head and neck tumors. We obtained a freeze dried stable formulation for the preparation of {sup 99m} Tc-(V)-Dmsa kit with a radiochemical purity higher than 90 %, which fulfills with the quality control of radiopharmaceuticals. Furthermore, we developed analytical techniques for the determination of the different chemical compounds into the lyophilized kit. On the other hand, we obtained the optimum conditions for preparation of {sup 186} Re-(V)-Dmsa complex in high radiochemical yields (>90%). (Author).

Phase stability, physical properties of rhenium diboride under high pressure and the effect of metallic bonding on its hardness

International Nuclear Information System (INIS)

Zhong, Ming-Min; Kuang, Xiao-Yu; Wang, Zhen-Hua; Shao, Peng; Ding, Li-Ping; Huang, Xiao-Fen

2013-01-01

Highlights: •The transition pressure P t between the ReB 2 –ReB 2 and MoB 2 –ReB 2 phases is firstly determinate. •The single-bonded B–B feather remains in ReB 2 compounds. •A semiempirical method to evaluate the hardness of crystals with partial metallic bond is presented. •The large hardness (39.1 GPa) of ReB 2 –ReB 2 indicate that it is a superhard material. •The zigzag interconnected B–Re and B–B covalent bonds underlie the ultraincompressibilities. -- Abstract: Using first-principles calculations, the elastic constants, thermodynamic property and structural phase transition of rhenium diboride under pressure are investigated by means of the pseudopotential plane-waves method, as well as the effect of metallic bond on its hardness. Eight candidate structures of known transition-metal compounds are chosen to probe for rhenium diboride ReB 2 . The calculated lattice parameters are consistent with the experimental and theoretical values. Based on the third order Birch–Murnaghan equation of states, the transition pressure P t between the ReB 2 –ReB 2 and MoB 2 –ReB 2 phases is firstly determinate. Elastic constants, shear modulus, Young’s modulus, Poisson’s ratio and Debye temperature are derived. The single-bonded B–B feather remains in ReB 2 compounds. Furthermore, according to Mulliken overlap population analysis, a semiempirical method to evaluate the hardness of multicomponent crystals with partial metallic bond is presented. Both strong covalency and a zigzag topology of interconnected bonds underlie the ultraincompressibilities. In addition, the superior performance and large hardness (39.1 GPa) of ReB 2 –ReB 2 indicate that it is a superhard material

Low energy excitations in superconducting La1.86Sr0.14CuO4

DEFF Research Database (Denmark)

Mason, T.E.; Aeppli, G.; Hayden, S.M.

1993-01-01

We present magnetic neutron scattering and specific heat data on the high-T(c) superconductor La1.86Sr0.14CuO4. Even when the samples are superconducting and the magnetic response, chi'', is suppressed, there are excitations with energies well below 3.5k(B)T(c). The wave-vector dependence of chi...

Design of a formulation for the preparation of 99m Tc-(V)-Dmsa and 186 Re-(V)-Dmsa

International Nuclear Information System (INIS)

Marquez L, M.B.

1998-01-01

Among the radiopharmaceuticals used for neoplasia, we can find the dimercaptosuccinic acid (Dmsa) labelled with 99m Tc and 186/188 Re. Initially, the 99m Tc-(III)-Dmsa was employed as a renal image agent. Nevertheless, when it is prepared into a basic solution, the 99m Tc-(V)-Dmsa complex is produced in high yield being cumulated by cells with a great metabolic activity. This property makes it a useful radiopharmaceutical for the detection of medullary thyroid carcinoma (MTC), soft-tissue tumors and other head and neck tumors. On the other hand, the renewed interest in β - emitting radionuclides, suggests that the 186 Re-(V)-Dmsa complex could be used as antineoplastic agent in therapy. However, the techniques reported for the preparation of these compounds lack of stability studies and they are still in process of investigation, compromising to continue on the development of the radiopharmaceuticals by introducing new possibilities for better products already known, obtaining in this way, the approximation to the ideal radiopharmaceutical. The objective of this work is to design a freeze dried kit formulation for the instant preparation of 99m Tc-(V)-Dmsa and 186 Re-(V)-Dmsa complexes useful in the diagnostic and therapy of soft-tissue tumors and other head and neck tumors. We obtained a freeze dried stable formulation for the preparation of 99m Tc-(V)-Dmsa kit with a radiochemical purity higher than 90 %, which fulfills with the quality control of radiopharmaceuticals. Furthermore, we developed analytical techniques for the determination of the different chemical compounds into the lyophilized kit. On the other hand, we obtained the optimum conditions for preparation of 186 Re-(V)-Dmsa complex in high radiochemical yields (>90%). (Author)

Preliminary measurements of k{sub 0} values for W-186

Energy Technology Data Exchange (ETDEWEB)

Barros, Lívia F.; Dias, Mauro S.; Koskinas, Marina F.; Yamazaki, Ione M.; Semmler, Renato, E-mail: lfbarros@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

2017-07-01

There are various methods of neutron activation analysis, one of these is the k{sub 0} Method for quantitative reactor Neutron Activation Analysis (NAA). The k{sub 0}-NAA procedure is nowadays widely used in numerous laboratories performing NAA all over the world. Among these reactions, {sup 186}W(n, γ){sup 187}W can be considered important because it can be used for a W concentration measurements. The irradiations were performed at position 24A, near the core of the IEA-R1 4.5 MW swimming-pool nuclear research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP - Nuclear and Energy Research Institute), in Sao Paulo, Brazil. Two irradiations were carried out in sequence, using two sets of samples: the first with a cadmium cover around the samples and the second without, in a total of three data sets with and without Cd cover performed in 2014 and 2015. The activity measurements were carried out in an HPGe gamma-ray spectrometer. Standard sources of {sup 152}Eu, {sup 133}Ba, {sup 60}Co and {sup 137}Cs supplied by the IAEA were used in order to obtain the HPGe gamma-ray peak efficiency as a function of the energy. The covariance matrix methodology was applied to all uncertainties involved. The preliminary values of k{sub 0} for {sup 186}W(n, γ){sup 187}W reaction for the gamma transition energy of 479.53 keV was 3.17 x 10{sup -2}(5), for 618.77 keV was 9.08 x 10{sup -3}(15) and for 685.77 keV was 3.88x10{sup -2}(6). These preliminary values for k{sub 0} have been compared with the literature. (author)

Improving accuracy and reliability of 186-keV measurements for unattended enrichment monitoring

International Nuclear Information System (INIS)

Ianakiev, Kiril D.; Boyer, Brian D.; Swinhoe, Martyn T.; Moss, Cal E.; Goda, Joetta M.; Favalli, Andrea; Lombardi, Marcie; Paffet, Mark T.; Hill, Thomas R.; MacArthur, Duncan W.; Smith, Morag K.

2010-01-01

Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants (GCEPs), whilst reducing the inspection effort, is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One aspect of this measurement is a simple, reliable and precise passive measurement of the 186-keV line from 235 U. (The other information required is the amount of gas in the pipe. This can be obtained by transmission measurements or pressure measurements). In this paper we describe our research efforts towards such a passive measurement system. The system includes redundant measurements of the 186-keV line from the gas and separately from the wall deposits. The design also includes measures to reduce the effect of the potentially important background. Such an approach would practically eliminate false alarms and can maintain the operation of the system even with a hardware malfunction in one of the channels. The work involves Monte Carlo modeling and the construction of a proof-of-principle prototype. We will carry out experimental tests with UF 6 gas in pipes with and without deposits in order to demonstrate the deposit correction.

Predictive implications of bone turnover markers after palliative treatment with {sup 186}Re-HEDP in hormone-refractory prostate cancer patients with painful osseous metastases

Energy Technology Data Exchange (ETDEWEB)

Zafeirakis, Athanasios [401 Army Hospital of Athens, Department of Nuclear Medicine, Athens (Greece); Papatheodorou, Georgios [401 Army Hospital of Athens, Clinical Research Unit, Athens (Greece); Arhontakis, Athanasios [401 Army Hospital of Athens, Department of Urology, Athens (Greece); Gouliamos, Athanasios; Vlahos, Lambros [Aretaieion University Hospital, Athens Medical School, Department of Radiology, Athens (Greece); Limouris, Georgios S. [Aretaieion University Hospital, Athens Medical School, Department of Nuclear Medicine, Athens (Greece)

2010-01-15

To prospectively evaluate the predictive value of various bone formation and resorption markers in patients with bone metastases from prostate cancer after palliative treatment with {sup 186}Re-1,1-hydroxyethylidene diphosphonate ({sup 186}Re-HEDP). Included in the study were 36 men with prostate cancer, suffering from painful osseous metastases and treated with {sup 186}Re-HEDP. None had received any treatment that would have interfered with bone metabolism before {sup 186}Re-HEDP treatment or throughout the follow-up period. For each patient, pretreatment and posttreatment serum levels of osteocalcin (OC), bone alkaline phosphatase (BALP), aminoterminal (PINP) and carboxyterminal (PICP) propeptides of type I collagen, amino-terminal (NTx) and carboxyterminal (CTx) telopeptides of type I collagen and their combinations were compared with the level and duration of pain response to radionuclide treatment. Pain response was correlated only with pretreatment {nu}{tau}x/PINP, PICP/PINP and NTx/CTx ratios and posttreatment decrease in baseline NTx and PICP values (p=0.0025-0.035). According to multivariate and ROC analyses, the best marker-derived predictors of better and longer duration of response to {sup 186}Re-HEDP treatment were a posttreatment decrease in NTx of {>=}20% (RR=3.44, p=0.0005) and a pretreatment NTx/PINP ratio of {>=}1.2 (RR=3.04, p=0.036) NTx, a potent collagenous marker of bone resorption, along with the novel NTx/PINP ratio provide useful cut-off values for identifying a group of patients suffering from painful osseous metastases from hormone-refractory prostatic carcinoma who do not respond to palliative treatment with {sup 186}Re-HEDP. This information could help avoid an inefficient and expensive radionuclide treatment. Also, in the cohort of patients who will eventually undergo such treatment, the medium-term posttreatment changes in NTx offer valuable predictive information regarding long-term palliative response. (orig.)

Measurement of 230Pa and 186Re Production Cross Sections Induced by Deuterons at Arronax Facility

Science.gov (United States)

Duchemin, Charlotte; Guertin, Arnaud; Metivier, Vincent; Haddad, Ferid; Michel, Nathalie

2014-02-01

A dedicated program has been launched on production of innovative radionuclides for PET imaging and for β- and α targeted radiotherapy using proton or α particles at the ARRONAX cyclotron. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Two isotopes dedicated to targeted therapy have been considered: 226Th, a decay product of 230Pa, and 186Re. The production cross sections of 230Pa and 186Re, as well as those of the contaminants created during the irradiation, have been determined by the stacked-foil technique using deuteron beams. Experimental values have been quantified using a referenced cross section. The measured cross sections have been used to determine expected production yields and compared with the calculated values obtained using the Talys code with default parameters.

3.3.1. Synthesis, Spectroscopy and Structural Analysis of Technetium and Rhenium Nitrosyl Complexes

Directory of Open Access Journals (Sweden)

Terrence\tNicholson*,\tEsther\tChunb, Ashfaq\tMahmood,\tPeter\tMueller,\tAlan\tDavisona\tand\tAlun\tG.\tJones

2015-11-01

Full Text Available Here we report an overview of our synthetic, spectroscopic and structural studies of technetium and rhenium nitrosyl complexes. We review the results from various notes and short papers reported over the past 15 years and discuss their significance in terms of radiopharmaceutical design.A single new complex is reported, the ReI-NO complex [ReICl2(NO(py-N(Et-py], in which the tridentate ligand di-(2-picolyl(N-ethylamine, (py-N(Et-py, is coordinated in a meridional manner. This complex was synthesized from the reaction of the ReI-nitrosyl complex ReCl2(NO(NCMe3] and the neutral tri-amine ligand py-N(Et-py in methylene chloride under argon. The bright red species was isolated chromatographically and recrystallized from CH2Cl2/MeOH under diethylether.A review of literature values for nitrosyl complexes with various ligands bound to the coordination sitetrans- to the nitrosyl group shows only minor variations in the M-N-O bond angle.

76 FR 22160 - Fifty-Fourth Meeting: RTCA Special Committee 186: Automatic Dependent Surveillance-Broadcast (ADS-B)

Science.gov (United States)

2011-04-20

... Rooms, 1828 L Street, NW., Suite 805, Washington, DC 20036. FOR FURTHER INFORMATION CONTACT: RTCA Secretariat, 1828 L Street, NW., Suite 805, Washington, DC, 20036, (202) 833-9339; fax (202) 833-9434; Web.... 035-11/SC186-307 FAA Surveillance and Broadcast Services (SBS) Program Status Traffic Situation...

Rhenium (5) and molybdenum (5) complexes with 4',4''(5'')-ditretbutyldibenzo-24-crown-8. Kompleksnye soedineniya reniya (5) i molibdena (5) s 4',4''(5'')-ditretbutildibenzo-24-kraun-8

Energy Technology Data Exchange (ETDEWEB)

Ashurova, N Kh; Yakubov, K G; Basitova, S M; Tashmukhamedova, A K; Sajfullina, N Zh [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (USSR)

1989-10-01

Rhenium and molybdenum complexes in +5 oxidation degree with 4',4''(5'')-ditretbutyldibenzo-24-crown-8 (L) are synthesized with 75-95 % yield. Composition and structure of compounds produced are investigated using element analysis, conductometry, IR spectroscopy, thermogravimetry methods. Oxidation degree of complexer metal is determined. It is ascertained that the compound composition corresponds to the MOLX{sub 3} formula, where M-Re, Mo; X-Cl{sup -}, Br{sup -}.

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source

International Nuclear Information System (INIS)

White, Shane A.; Landry, Guillaume; Reniers, Brigitte; Fonseca, Gabriel Paiva; Holt, Randy; Rusch, Thomas; Beaulieu, Luc; Verhaegen, Frank

2014-01-01

Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy ( w,m ) and dose to medium (D m,m ), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D 90 to PTV was reduced by between ∼4% and ∼40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%–15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. Conclusions: TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources

Structure of the Kπ=4+ bands in Os186,188

Science.gov (United States)

Phillips, A. A.; Garrett, P. E.; Lo Iudice, N.; Sushkov, A. V.; Bettermann, L.; Braun, N.; Burke, D. G.; Demand, G. A.; Faestermann, T.; Finlay, P.; Green, K. L.; Hertenberger, R.; Leach, K. G.; Krücken, R.; Schumaker, M. A.; Svensson, C. E.; Wirth, H.-F.; Wong, J.

2010-09-01

The (He3,d) single-proton stripping reaction has been performed on targets of Re185,187 to investigate the structures of the 43+ states in Os186,188. The experiment employed 30 MeV He3 beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between 5° and 50° for states up to approximately 3 MeV in excitation energy. Large (5)/(2)+[402]π+(3)/(2)+[402]π two-quasiparticle components are deduced for the 43+ levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, γ-γ component in the 43+.

Laparoscopic finding of female infertility-a study of 186 cases at a tertiary care hospital

International Nuclear Information System (INIS)

Yasir, N.; Fatima, A.; Parveen, S.; Tariq, H.

2014-01-01

Objective: To study the various causes of female infertility, diagnosed at laparoscopy. Study Design: Descriptive study. Place and Duration of Study: The study was conducted at Military Hospital Rawalpindi, Pakistan from April 2008 to December 2010. Patients and Methods: A series of 186 patients, having either primary or secondary infertility admitted through gynae outpatient department undergoing diagnostic laparoscopy and meeting inclusion criteria were studied. The data was collected prospectively and analysed in the form of frequency and percentages by using SPSS version 10. Results: Amongst the cohort of 186 patients, 148 (79.6%) had primary and 38 (20.4%) had secondary infertility. Their ages ranged from 20 to 43 years. Mean age of study participants was 30.14 +- 4.04 years. Mean duration of infertility was 9.5 years. No laparoscopic abnormality was found in 51 (27.9%), while there were abnormal findings in 135 (72.6%) patients. Conclusion: Commonest etiological factor was tubal blockade in both types of infertility. Other factors were endometriosis, pelvic adhesions and fibroids. Laparoscopy is minimally invasive yet a reliable procedure for visualization of internal architecture of the female pelvis. (author)

The effectiveness of different interventional methods for partial fallopian tube obstruction: an analysis of 186 cases

International Nuclear Information System (INIS)

Tan Yiqing; Wang Yase; Dai Hongxiu; Li Haitao; Deng Yi; Xiong Liqin

2011-01-01

Objective: To evaluate selective salpingo-catheterization recanalization therapy in treating partial fallopian tube obstruction through comparing its clinical effectiveness with that of non-interventional radiology methods. Methods: During the period from January 2008 to October 2010, a total of 186 infertility women with partial fallopian tube obstruction, which was confirmed with hysterosalpingography, were encountered in authors' hospital. This study protocol was approved by our hospital ethics committee, and informed consent was obtained from all patients. According of different treatment methods, 186 patients were divided into two groups. Patients (n=78) in group A received non-interventional radiology methods, including hydrotubation, enema, laparoscopy, physical therapy and traditional Chinese medication, while patients (n=108) in group B received selective salpingo-catheterization recanalization therapy. All 186 patients were followed up for more than six months. Close observation on the pregnancy incidence after different treatments and fallopian tube patency was carried out. The clinical findings were documented. The results were statistically analyzed by using paired 'x2' test. Results: Half a year after different procedures, in group A the pregnancy rate was 12.82% (n=10), and different degrees of fallopian tube obstruction were found in 31.58% patients. Whereas in group B, during the same period of observation, the pregnancy rate was 58.33% (n=63), and partial occlusion in cornual region was seen in one patient (0.47%). Significant difference in both pregnancy rate and fallopian tube occlusion rate existed between two groups (P<0.05). Conclusion: Because of its minimal invasiveness, high effectiveness and safety, the selective salpingography together with fallopian tube recanalization procedures are well accepted by the patients. The selective salpingo-catheterization recanalization therapy is superior to non-interventional radiology methods in

Comparative study of skeletal dosimetry methods in therapeutic schemes with Re186 HEDP and Sm153 EDTMP

International Nuclear Information System (INIS)

Papanikolos, G.; Lyra, M.; Kontogeorgakos, D.; Jordanou, J.; Vlahos, L.; Limouris, G.

2005-01-01

Full text: Optimum therapeutic management of patients suffering from metastatic bone pain, requires accurate calculations concerning absorbed dose by metastatic lesions and other critical organs, such as red marrow. Mean absorbed dose, which is the current parameter used to predict the efficacy of the treatment, can either overestimate or underestimate, actual doses delivered in these organs/tissues of interest (TOIs). This study presents differences in dosimetric calculations derived utilizing parameters from different sources (MIRDOSE3, MIRD Pamphlet No 11 and S values published by Bouchet et al.), in therapeutic schemes with Re186HEDP and Sm153EDTMP. A set of planar scintigraphic images for 2 groups of patients (1 for Re 186 patients and the other for Sm153 patients) were obtained in the following sequence: 2 during the first 24h post injection (the last of which at 24h post injection) and 2 more from 24h 7d post injection. Processing of the obtained images utilizing ROI quantitative methods, previously calibrated with waterphantom measurements, determine residence times and radionuclide uptakes not only by TOIs but by specific skeletal sites as well. Dosimetric calculations were performed using MIRDOSE3 computer code, S values from MIRD Pamphlet No 11 and site specific Re 186 and Sm 153 S values for several source target combinations within trabecular and cortical bone, reported by Bouchet et al. (J Nucl Med 2000; 41:189 212), along with cumulative site specific activities derived from values obtained by image processing. Skeletal averaged Re 186 and Sm 153 S values were also used from the aforementioned study by Bouchet et al. Time activity curves for various skeletal sites were generated for both groups of patients. Absorbed dose distributions along with time dose rate curves were derived for both red marrow and different regions of the skeleton. Comparisons are made between these parameters and mean absorbed doses calculated using skeletal averaged S values

Thermal transformations of oxohalide complexes of rhenium(5) and molybdenum(5) with diazo-18-crown-6 in solid phase. Termicheskie prevrashcheniya oksogalogenidnykh kompleksov reniya(5) i molibdena(5) s diaza-18-kraun-6 v tverdoj faze

Energy Technology Data Exchange (ETDEWEB)

Ashurova, N Kh; Yakubov, K G [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

1992-11-01

Methods for synthesis and separation in solid state of the rhenium(5) and molybdenum(5) onium complexes with diaza-18-crown-6(L), the content of which according to the data of elementary analysis, IRS in the close and remote areas, thermogravimetry, conductometry and potentiometry corresponds to the (H[sub 2]L)[EOX[sub 5

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

International Nuclear Information System (INIS)

Chen, JianQing.

1997-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Chen, JianQing

1997-01-01

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.

Diphosphonic Acid (HEDP) Complex As A, Bone Pain Palliative Agent

International Nuclear Information System (INIS)

H G, Adang; Mutalib, A; Bagiawati, Sri; S, Evi; Aguawarini, Sri; Abidin

2003-01-01

Bone pain is a common complication for patient with bone metastases from prostate, breasts, lung and renal cancers. The systemic treatment of metastatic bone cancers can be done by using analgesic drug therapy, hormonal therapy, chemotherapy, narcotic (morphine) and radiopharmaceuticals. Samarium-153 EDTMP is one of the most widely used radiopharmaceutical for the treatment of metallics bone pain. Preparation and quality control of 186 Re-HEDP have been carried out. Radiochemical purity was analysed using paper chromatography and resulted in maximum yields more than 90 % . Complexes quite were stable for 3 days when stored at 4 o C. Rhenium-186 HEDP complex contents in the blood reach optimum activity after 5 minutes and decrease drastically at 24 hours post injection. The complex showed major renal clearance up to 41 % as perrhenate ion within 24 hours after injection, Biodistribution pattern of the injected complex in mice indicates that the accumulated optimum activity in the bone was obtained between 2 - 24 hours post injection, Sterility and pyrogenicity test indicated that the complex were sterile and pyrogen free

Trinuclear rhenium(III) halide clusters with carboxylate ligands

Science.gov (United States)

Dougan, Jeffrey Steven

Four mono(carboxylato)trirhenium complexes and three bis(carboxylato)trirhenium complexes have been synthesized and characterized, principally by mass spectrometry, with supporting evidence from X-ray diffraction. These compounds represent the first trinuclear rhenium carboxylate complexes. The reactions generally proceed readily under comparatively mild conditions. Mass spectrometry has again proved its usefulness as a technique in the field of metal cluster chemistry, having provided the initial identification of the products of the reactions studied. These compounds provide a further base to which future mass spectra of metal cluster compounds can be compared. Re-examination of a reaction reported by Taha and Wilkinson has also cast considerable doubt onto the validity of a conversion widely reported in the literature that transforms (Re3Cl9) x into [Re2(O2CCH3)4Cl 2]. We believe that the literature result is a consequence of the purity of the metal precursor, and suggest that the starting material in the earlier work may have contained ReCl4 or ReCl5. The importance of mass spectrometry in the characterization of the new compounds synthesized in this project has led to a thorough study of calculated isotopic distributions. The information gathered suggests that for isotopically simple molecules, the choice of algorithm for computing an isotopic distribution is unimportant. However, it is important to compute the mass spectrum of an isotopically complex molecule using an algorithm that can, if desired, show the underlying isotopic fine structure of a peak of interest. In the last chapter of this thesis, the results of a project in chemistry education research are presented. Predicting the success of students in general chemistry has long been of interest to the chemistry education community, and several factors have been identified as contributing factors. An off-hand comment by a student inspired an examination of whether continuity with the same instructor for

Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

Science.gov (United States)

Wu, Tao; Higashiguchi, Takeshi; Li, Bowen; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Dunne, Padraig; O'Reilly, Fergal; Sokell, Emma; Liu, Luning; O'Sullivan, Gerry

2015-08-01

Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1-7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 1014 W cm-2 for the former and 5.5 × 1012 W cm-2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3-6.3 nm and 1.5-4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5-4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p64dN-4p54dN+1 + 4p64dN-14f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7-5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3-4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified.

Sorption of technetium and its analogue rhenium on bentonite material under aerobic conditions

International Nuclear Information System (INIS)

Koudelkova, M.; Vinsova, H.; Konirova, R.; Ernestova, M.; Jedinakova-Krizova, V.; Tereesha, M.

2003-01-01

The uptake of technetium on bentonite materials has been studied from the point of view of characterization of long-term radioactive elements behavior in nuclear waste repository. Bentonite R (locality Rokle, Czech Republic) and two types of model groundwater (granitic and bentonite) were selected for the sorption experiments. The aim of our research has been to find out the conditions suitable for the technetium sorption on selected bentonite under oxidizing condition. The sorption experiments with Tc-99 on bentonite have been carried out by batch method. The influence of the addition of different materials (e.g. activated carbon, graphite, Fe 2+ ) with bentonite, the effect of solid: aqueous phase ratio and a pH value on the percentage of technetium uptake and on the K d values were tested. Perrhenate was selected as an analogue of pertechnetate in non-active experiments of capillary electrophoresis (CE) and isotachophoresis (ITP). The percentage of rhenium sorbed on bentonite material was determined from the decrease of perrhenate peak area (CE) and from the shortening of the ITP zone corresponding to perrhenate. Both electromigration methods provided comparable results. The results obtained in this study with non-active material were compared to those of technetium acquired by radiometry and polarography. The 8 days kinetics of the perrhenate and pertechnetate sorption on bentonite was described mathematically with a tendency to predict long-term behavior of studied systems. (authors)

Clinical studies on the lymph flow of the esophagus by injecting sup(99m)Tc-rhenium colloid into the esophageal wall

International Nuclear Information System (INIS)

Baba, Masamichi; Tanabe, Gen; Nishi, Mitsumasa

1985-01-01

Using 29 operative cases lymph flow of the esophagus was investigated by injecting endoscopically sup(99m)Tc-Rhenium colloid. Rhenium colloid lymphoscintigraphy was made, and 30 -- 32 hours after injection RI up take (cpm/g) of resected lymph nodes was counted by scintillation counter. 1. RI up take of resected lymph nodes correspond with the lymphoscintigraphy of resected lymph nodes therefore, RI up take count was available to study the extra-mural lymph flow of the esophagus. 2. In the cases injected at upper part of the esophagus, the high counted RI up take was noted in bifurcation lymph nodes, upper mediastinal lymph nodes and bilateral supraclavicular lymph nodes. In the cases injected at middle part of the esophagus, bilateral supraclavicular lymph nodes, upper mediastinal lymph nodes and left gastric artery lymph nodes revealed the high RI up takes. In the cases injected at lower part of the esophagus, RI up take was highly noted in bifurcation lymph nodes, left gastric artery lymph nodes and celiac axis lymph nodes. In the cases injected at esophago-gastric junction, the high counted RI up take was noted in left gastric artery lymph nodes, celiac axis lymph nodes and the lymph nodes around the left renal vein. 3. In the cases injected at upper, middle parts of the esophagus, bilateral supraclavicular lymph nodes revealed the high RI up take. Some of these lymph nodes are regarded as directly connected with the extra-mural lymph vessls of the esophagus. Therefore, it was suggested that existence of ''direct lymph flow'' from which upper, middle intrathoracic esophagus directly connected to right supraclavicular lymph nodes. 4. It is important to perform bilateral modified neck dissection in case of upper, middle intrathoracic esophageal cancer and is important to dissect the lymph nodes around the left renal vein in case of esophago-gastric cancer and lower intrathoracic esophageal cancer. (J.P.N.)

Safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized monoclonal antibody BIWA 4 (Bivatuzumab) in patients with early-stage breast cancer.

Science.gov (United States)

Koppe, Manuel; Schaijk, Frank van; Roos, Jan; Leeuwen, Paul van; Heider, Karl-Heinz; Kuthan, Hartmut; Bleichrodt, Robert

2004-12-01

The aim of this prospective study was to evaluate the safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized anti-CD44v6 monoclonal antibody (MAb( BIWA 4 (Bivatuzumab( in 9 patients with early-stage breast cancer. Radioimmunoscintigraphy (RIS( was performed within 1, 24, and 72 hours after administration. BIWA 4 concentration in plasma (ELISA and radioactivity measurements( and the development of human antihuman antibody (HAHA( responses was determined. The biodistribution of (186)Re-BIWA 4 was determined by radioactivity measurements in tumor and normal tissue biopsies obtained during surgery 1 week after administration. Administration of (186)Re-BIWA 4 was well tolerated by all patients and no HAHA responses were observed. The mean t(1/2) in plasma of BIWA 4 (ELISA( was 81 hours (range, 67-97(, whereas the mean radioactivity t(1/2) tended to be longer, at 105 hours (range, 90-114(. RIS unmistakably showed the tumor in 3 patients. Less clear identifications were established in 3 additional patients. In 2 patients, the tumor was wrongly identified in the contralateral breast. Median tumor CD44v6 expression, as determined by immunohistochemistry, was 70% (range, 10-90%). Mean tumor uptake was 2.96% ID/kg (range, 0.92-6.27(, with no apparent correlation with either tumor CD44v6 expression, tumor-cell cellularity, or tumor diameter. Tumor-to-nontumor ratios were unfavorable for blood, bone marrow, mammary gland tissue, and skin. The (186)Re-labeled humanized MAb BIWA 4 can safely be administered to patients with early-stage breast cancer. Tumorto- nontumor ratios were unfavorable, with no apparent correlation with CD44v6 expression, tumor-cell cellularity, or tumor diameter. BIWA 4, therefore, appears to have limitations as a vehicle for radioimmunotherapy in patients with breast cancer.

Resistin facilitates VEGF-C-associated lymphangiogenesis by inhibiting miR-186 in human chondrosarcoma cells.

Science.gov (United States)

Su, Chen-Ming; Tang, Chih-Hsin; Chi, Meng-Ju; Lin, Chih-Yang; Fong, Yi-Chin; Liu, Yueh-Ching; Chen, Wei-Cheng; Wang, Shih-Wei

2018-05-03

Chondrosarcoma is a common primary malignant tumor of the bone that can metastasize through the vascular system to other organs. A key step in the metastatic process, lymphangiogenesis, involves vascular endothelial growth factor-C (VEGF-C). However, the effects of lymphangiogenesis in chondrosarcoma metastasis remain to be clarified. Accumulating evidence shows that resistin, a cytokine secreted from adipocytes and monocytes, also promotes tumor pathogenesis. Notably, chondrosarcoma can easily metastasize. In this study, we demonstrate that resistin enhances VEGF-C expression and lymphatic endothelial cells (LECs)-associated lymphangiogenesis in human chondrosarcoma cells. We also show that resistin triggers VEGF-C-dependent lymphangiogenesis via the c-Src signaling pathway and down-regulating micro RNA (miR)-186. Overexpression of resistin in chondrosarcoma cells significantly enhanced VEGF-C production and LECs-associated lymphangiogenesis in vitro and tumor-related lymphangiogenesis in vivo. Resistin levels were positively correlated with VEGF-C-dependent lymphangiogenesis via the down-regulation of miR-186 expression in clinical samples from chondrosarcoma tissue. This study is the first to evaluate the mechanism underlying resistin-induced promotion of LECs-associated lymphangiogenesis via the upregulation of VEGF-C expression in human chondrosarcomas. We suggest that resistin may represent a molecular target in VEGF-C-associated tumor lymphangiogenesis in chondrosarcoma metastasis. Copyright © 2018 Elsevier Inc. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

Knappschneider, Arno

2014-10-13

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.

186Re-1,4,8,11-tetraaza cyclotetradecyl-1,4,8,11-tetramethylene phosphonic acid: a novel agent for possible use in metastatic bone-pain palliation

International Nuclear Information System (INIS)

Kothari, Kanchan; Samuel, Grace; Banerjee, Sharmila; Unni, P.R.; Sarma, H.D.; Chaudhari, P.R.; Unnikrishnan, T.P.; Pillai, M.R.A.

2001-01-01

In connection with our work on the development of 186 Re-tetra-phosphonates with optimum properties for use in bone pain palliation, a novel cyclic tetraphosphonate derivative, has been synthesized, complexed with 186 Re and evaluated with promising results. The ligand, which consists of a cyclic array of tetra-aminomethylphosphonate groups, was synthesized using orthophosphorus acid, 1,4,8,11-tetraazacyclotetradecane and formaldehyde. The labeling conditions with 186 Re have been standardized under varying reaction conditions to give maximum yield. In a reaction volume of 1 mL, maximum complexation yield of 98% was observed at pH 2 using 0.1 mg Re (37-370 MBq) for a ligand concentration at 9x10 -2 M/L, under heating at 100 deg. C for 30 min with 2 mg of stannous chloride. The complex was found to be stable for 6 days with RC purity remaining ∼97%. The complex was characterized by paper chromatography in saline and acetone, wherein the R f exhibited were 0.9 and 0, respectively. Biodistribution studies of the complex were performed in male Wistar rats. Activity in femur which was observed to be 1.8%/g (equivalent to about 23% of the injected activity in skeleton) at 3 h post injection remained almost constant up to 48 h. Minimum activity was observed in blood and other soft tissues. The complex showed major renal clearance. Scintigraphic images in rabbits after injecting 70-100 MBq of 186 Re-CTMP and using a dual head gamma camera were observed to be superior to 186 Re-HEDP, prepared by a procedure standardized by us. Insignificant activity was observed in other vital organs. The results suggest the suitability of the complex for further evaluation in higher animals for bone pain palliation

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

International Nuclear Information System (INIS)

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

2017-01-01

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 188 Re-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 188 Re-nanoporous composites can be promising radionuclide delivery systems for cancer treatment. (paper)

Assessment of the MELCOR 1.8.6 condensation heat transfer model under the presence of noncondensable gases

Energy Technology Data Exchange (ETDEWEB)

Yoo, Ji Min; Lee, Dong Hun; Jeong, Jae Jun [Pusan National University, Busan (Korea, Republic of)

2016-05-15

Condensation heat transfer under the presence of noncondensable gases (NCGs) is an important issue in nuclear safety because the presence of even a small quantity of NC gases in the vapor largely reduces the condensation rate. The extensive assessment of the condensation model of the safety analysis codes has been also performed. When NCGs are present, the condensation phenomenon is largely reduced by accumulated NCGs near the condensing surface. Since the total pressure remains constant, the partial pressure of vapor at the liquid-vapor interface is lower than that in the bulk mixture, providing the driving force for vapor diffusion towards the liquid-vapor interface. The main objective of the present study is the assessment of the condensation heat transfer model of the severe accident code MELCOR 1.8.6 under the presence of NCGs. In this study, the condensation heat transfer model of the MELCOR 1.8.6 is assessed using various experiments which have 4 different types of geometry. Through the comparison of the results, it was shown that the MELCOR code generally under-predicts the condensation heat transfer except the condensation on outer surface of vertical pipes and improvement is needed for other geometries.

Syntheses and structures of technetium(V) and rhenium(V) oxo complexes of peptide having KYC-sequence

International Nuclear Information System (INIS)

Takayama, T.; Suzuki, K.; Sekine, T.; Kudo, H.

2000-01-01

Technetium(V) and rhenium(V) oxo complexes of a peptide having a KYC-sequence such as KYCAR (H 3 L 5 ) and KYCAREPPTRTNAYQGQG-NH 2 (H 3 L 18 ) were synthesized, and structures of the complexes were characterized by spectroscopic techniques. All of the complexes were synthesized by the ligand exchange reaction of [(n-C 4 H 9 ) 4 N][MOCl 4 ] (M = 99 Tc, Re) with peptide in methanol or dimethylformamide solution. These complexes have a square pyramidal structure with an oxo ligand at the apical position. The peptide is coordinated to a metal atom through N amine of lysine. S thiol of cysteine, and N amide of tyrosine and cysteine in the equatorial plane. A lysine (CH 2 ) 4 NH 2 group of the L 5 ligand has the syn conformation with respect to metal-oxo bonding in the complex. The syn isomer was selectively formed in the ligand exchange reaction. The conversion of the syn isomer to the anti isomer was observed only for syn-[ReO(L 5 )], in which the coordination of water to the trans position of the oxo ligand was involved. (orig.)

Fusion and quasifission studies for the 40Ca+186W,192Os reactions

Science.gov (United States)

Prasad, E.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; Palshetkar, C. S.; Rafferty, D. C.; Ramachandran, K.; Simenel, C.; Wakhle, A.

2017-09-01

Background: All elements above atomic number 113 have been synthesized using hot fusion reactions with calcium beams on statically deformed actinide target nuclei. Quasifission and fusion-fission are the two major mechanisms responsible for the very low production cross sections of superheavy elements. Purpose: To achieve a quantitative measurement of capture and quasifission characteristics as a function of beam energy in reactions forming heavy compound systems using calcium beams as projectiles. Methods: Fission fragment mass-angle distributions were measured for the two reactions 40Ca+186W and 40C+192Os, populating 226Pu and 232Cm compound nuclei, respectively, using the Heavy Ion Accelerator Facility and CUBE spectrometer at the Australian National University. Mass ratio distributions, angular distributions, and total fission cross sections were obtained from the experimental data. Simulations to match the features of the experimental mass-angle distributions were performed using a classical phenomenological approach. Results: Both 40Ca+186W and 40C+192Os reactions show strong mass-angle correlations at all energies measured. A maximum fusion probability of 60 -70 % is estimated for the two reactions in the energy range of the present study. Coupled-channels calculations assuming standard Woods-Saxon potential parameters overpredict the capture cross sections. Large nuclear potential diffuseness parameters ˜1.5 fm are required to fit the total capture cross sections. The presence of a weak mass-asymmetric quasifission component attributed to the higher angular momentum events can be reproduced with a shorter average sticking time but longer mass-equilibration time constant. Conclusions: The deduced above-barrier capture cross sections suggest that the dissipative processes are already occurring outside the capture barrier. The mass-angle correlations indicate that a compact shape is not achieved for deformation aligned collisions with lower capture barriers

POX 186: the ultracompact blue compact dwarf galaxy reveals its nature

Science.gov (United States)

Doublier, V.; Kunth, D.; Courbin, F.; Magain, P.

2000-01-01

High resolution, ground based R and I band observations of the ultra compact dwarf galaxy POX 186 are presented. The data, obtained with the ESO New Technology Telescope (NTT), are analyzed using a new deconvolution algorithm which allows one to resolve the innermost regions of this stellar-like object into three Super-Star Clusters (SSC). Upper limits to both masses (M ~ 105 Msun) and physical sizes (<=60pc) of the SSCs are set. In addition, and maybe most importantly, extended light emission underlying the compact star-forming region is clearly detected in both bands. The R-I color rules out nebular Hα contamination and is consistent with an old stellar population. This casts doubt on the hypothesis that Blue Compact Dwarf Galaxies (BCDG) are young galaxies. based on observations carried out at NTT in La Silla, operated by the European Southern Observatory, during Director's Discretionary Time.

Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

International Nuclear Information System (INIS)

Kucera, J.; Lucanikova, M.; Czech Technical Univ., Prague

2006-01-01

Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng x g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng x g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of ∼ 10 ng x g -1 was found. Significantly elevated values of Re, up to 90 ng x g -1 were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggested possible competition between Re and Tc in the accumulation process. (author)

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

Directory of Open Access Journals (Sweden)

M. Klein

2013-01-01

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.

Structure of the 4^+3 States in ^186,188Os

Science.gov (United States)

Phillips, A. A.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Schumaker, M. A.; Svensson, C. E.; Wong, J.; Hertenberger, R.; Faestermann, T.; Krücken, R.; Wirth, H.-F.; Bettermann, L.; Braun, N.; Burke, D. G.

2007-10-01

The structures of 4^+3 states in the Os nuclei have been the subject of debate for the past several decades. Based on measured B(E2) values, they were interpreted in ^186-192Os as K^π=4^+ two-phonon γ vibrations, whereas inelastic scattering results, and single-proton transfer (d,^3He) and (t,α) imply a hexadecapole phonon description. Uncertainties in the (t,α) reaction mechanism, however, were cited as preventing a firm conclusion based on those data. To help clarify the nature of these K^π=4^+ bands, we have performed a (^3He,d) stripping reaction on targets of ^185,187Re using 30 MeV ^3He beams provided by the MP-tandem facility of the LMU/TUM in Garching. With an energy resolution of 13 keV, the deuterons were analyzed at 9 angles ranging from 5^o to 50^o with the Q3D spectrograph, and absolute cross sections were obtained for levels up to 3 MeV in excitation energy. Preliminary results will be presented.

Rhenium(5) and molybdenum(5) complexes with 4',4[sup (]5[sup )]-divaleryldibenzo-18-crown-6. Kompleksnye soedineniya reniya(5) i molibdena(5) s 4',4[sup (]5[sup )]-divalerildibenzo-18-kraun-6

Energy Technology Data Exchange (ETDEWEB)

Ashurova, N Kh; Yakubov, K G; Tashmukhamedova, A K; Basitova, S M [Tadzhikskij Gosudarstvennyj Univ., Dushanbe (Tajikistan)

1993-02-01

Methods for synthesizing oxohalide complexes of rhenium and molybdenum with +5 oxidation degree with 4',4[sup (5)]-divaleryldibenzo-18-crown-6 were developed. Content and composition of prepared compounds were investigated by the methods of element analysis, crystal optics, conductometry, IR spectroscopy in the near and far regions, thermogravimetry. Oxidation degree of the complex-forming metal was determined. It was established that composition of the compounds coressponded to the general formula MOLX [sub [center dot

Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

International Nuclear Information System (INIS)

Pigni, Marco T; Leal, Luiz C

2015-01-01

Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186 W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten - namely, 182 W(26.5%), 183 W(14.31%), 184 W(30.64%), and 186 W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

Detection of endotoxins in radiopharmaceutical preparations. III. Limulus test assessment using radiopharmaceutical preparations; correlation with the rabbit pyrogen test

Energy Technology Data Exchange (ETDEWEB)

Cohen, Y; Bahri, F; Bruneau, J; Dubuis, M; Dubuis, N; Merlin, L; Michaud, T; Peysson, S

1986-01-01

Experiments using 17 radiopharmaceuticals containing known amounts of added endotoxin show that none of them inhibits the pyrogenic reaction of the rabbit. Gelation of the Limulus amoebocyte lysate (LAL) is inhibited by 4 of them: colloidal erbium 169Er citrate, colloidal rhenium 186Re sulfide, colloidal technetium /sup 99m/Tc (Re) sulfide for liver scintigraphy and the colloidal technetium /sup 99m/Tc (Re) sulfide for lymphography. This inhibition is cancelled, either by dilution or after neutral pH adjustment. Both controls were performed on 313 batches of various radiopharmaceuticals, 95% of results were identical (93% negative, 2% positive). The remaining 5% correspond to positive LAL tests vs negative rabbit tests on the same batches. No negative LAL test vs positive rabbit test was observed.

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

Directory of Open Access Journals (Sweden)

ALBANA VESELI

2012-11-01

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.

Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

International Nuclear Information System (INIS)

Wu, Tao; Dunne, Padraig; O’Reilly, Fergal; Sokell, Emma; Liu, Luning; O’Sullivan, Gerry; Higashiguchi, Takeshi; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Li, Bowen

2015-01-01

Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1–7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 10 14 W cm −2 for the former and 5.5 × 10 12 W cm −2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3–6.3 nm and 1.5–4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5–4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re 23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p 6 4d N -4p 5 4d N+1  + 4p 6 4d N−1 4f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7–5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3–4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified. (paper)

Physico-chemical characterisation and biological evaluation of 188-Rhenium colloids for radiosynovectomy

International Nuclear Information System (INIS)

Ures, Ma Cristina; Savio, Eduardo; Malanga, Antonio; Fernández, Marcelo; Paolino, Andrea; Gaudiano, Javier

2002-01-01

Radiosynovectomy is a type of radiotherapy used to relieve pain and inflammation from rheumatoid arthritis. In this study, 188-Rhenium ( 188 Re) colloids were characterized by physical and biological methodologies. This was used to assess which parameters of the kit formulation would be the basis in the development of a more effective radiopharmaceutical for synovectomy. Intraarticular injection in knees of rabbits assessed cavity leakage of activity. The physical characteristics of tin (Sn) and sulphur (S) colloids were determined to assess the formulation with suitable properties. Particles were grouped in three ranges for analyzing their distribution according to their number, volume and surface. The ideal particle size range was considered to be from 2 to 10 microns. Membrane filtration and laser diffraction characterization methodologies were used. While membrane filtration could give misleading data, laser diffraction proportions more reliable results. The Sn colloid showed a better distribution of particle volume and surface than S colloid, in the 2 to 10 microns range. The 188 Re-Sn colloid was obtained with a radiochemical purity higher than 95% after 30 minutes of autoclaving. While Sn colloid kit stability was verified for 60 days, the 188 Re-Sn preparation was stable in the first 24 hrs. No significant intrabatch variability (n = 3) was detected. Biodistribution and scintigraphic studies in rabbits after intraarticular injection showed relevant activity only in knee, being 90% at 48 hours. The 188 Re-Sn colloid is easy to prepare, is stable for 24 hours and shows minimal cavity leakage after intraarticular injection into rabbit knees, suggesting this radiotherapeutical agent has suitable physical properties for evaluation for joint treatment in humans

Glass microspheres for medical applications

Science.gov (United States)

Conzone, Samuel David

microspheres containing 3.7 GBq of 186Re and 8.5 GBq of 188Re could be used to deliver a 100 Gy dose to a cancerous tumor, while limiting the total body dose caused by rhenium dissolution to approximately 1 mGy.

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source.

Science.gov (United States)

White, Shane A; Landry, Guillaume; Fonseca, Gabriel Paiva; Holt, Randy; Rusch, Thomas; Beaulieu, Luc; Verhaegen, Frank; Reniers, Brigitte

2014-06-01

The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (Dw,m) and dose to medium (Dm,m), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D90 to PTV was reduced by between ~4% and ~40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%-15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study

Syntheses and structures of technetium(V) and rhenium(V) oxo complexes of peptide having KYC-sequence

Energy Technology Data Exchange (ETDEWEB)

Takayama, T.; Suzuki, K.; Sekine, T.; Kudo, H. [Dept. of Chemistry, Tohoku Univ., Sendai (Japan)

2000-07-01

Technetium(V) and rhenium(V) oxo complexes of a peptide having a KYC-sequence such as KYCAR (H{sub 3}L{sup 5}) and KYCAREPPTRTNAYQGQG-NH{sub 2} (H{sub 3}L{sup 18}) were synthesized, and structures of the complexes were characterized by spectroscopic techniques. All of the complexes were synthesized by the ligand exchange reaction of [(n-C{sub 4}H{sub 9}){sub 4}N][MOCl{sub 4}] (M = {sup 99}Tc, Re) with peptide in methanol or dimethylformamide solution. These complexes have a square pyramidal structure with an oxo ligand at the apical position. The peptide is coordinated to a metal atom through N{sub amine} of lysine. S{sub thiol} of cysteine, and N{sub amide} of tyrosine and cysteine in the equatorial plane. A lysine (CH{sub 2}){sub 4}NH{sub 2} group of the L{sup 5} ligand has the syn conformation with respect to metal-oxo bonding in the complex. The syn isomer was selectively formed in the ligand exchange reaction. The conversion of the syn isomer to the anti isomer was observed only for syn-[ReO(L{sup 5})], in which the coordination of water to the trans position of the oxo ligand was involved. (orig.)

SU-F-T-22: Clinical Implications When Using TG-186 (ACE) Heterogeneity Software

Energy Technology Data Exchange (ETDEWEB)

Likhacheva, A; Grade, E; Sadeghi, A; Sokolowski, T [Arizona Cancer Specialists, Mesa, AZ (United States)

2016-06-15

Purpose: The purpose of this study is to compare dosimetric calculations using traditional TG-43 formalism and Oncentra Brachy Advanced Collapsed cone Engine (ACE) TG-186 calculation algorithm in clinical setting. Methods: We analyzed dosimetry of four patients treated with accelerated partial breast irradiation using a multi-channel intracavitary device (SAVI). All patients were treated to 34 Gy in 10 fractions using a high-dose-rate (192) Ir source. The plans were designed and treated using the TG-43 model. ACE was used to assess the effect heterogeneity correction on various dosimetric parameters. Mass density was estimated using Hounsfield units. Results: Compared to TG-43 formalism, ACE estimated lower doses to targets and organs at risk. The mean difference was 19.8% (range 15.3–24.1%) for PTV-eval V200, 12.0% (range 9.7–17.7%) for PTV-eval V150, 4.3% (range 3.3–6.5%) for PTV-eval D95, 3.3% (range 1.4–5.4%) for PTV-eval D90, 5.4% (range 2.9–9.9%) for maximum rib dose, and 5.7% (2.4–7.4%) for maximum skin dose. There was no correlation between the magnitude of the difference and the PTV-eval volume, air volume, or tissue-applicator conformance. Conclusion: Based on our preliminary study, the TG-43 algorithm appears to overestimate the dose to targets and organs at risk when compared to the ACE TG-186 software. We hypothesize that air adjacent to the SAVI struts contributes to lack of scatter thereby contributing a significant difference in dose calculation when using ACE. We believe that ACE calculation provides a more realistic isodose distribution than TG-43. We plan to further investigate the impact of heterogeneity correction on brachytherapy planning for a wide variety of clinical scenarios, include skin, cervix/uterus, prostate, and lung.

National Ignition Facility subsystem design requirements target area auxiliary subsystem SSDR 1.8.6

International Nuclear Information System (INIS)

Reitz, T.

1996-01-01

This Subsystem Design Requirement (SSDR) establishes the performance, design, development, and test requirements for the Target Area Auxiliary Subsystems (WBS 1.8.6), which is part of the NIF Target Experimental System (WBS 1.8). This document responds directly to the requirements detailed in NIF Target Experimental System SDR 003 document. Key elements of the Target Area Auxiliary Subsystems include: WBS 1.8.6.1 Local Utility Services; WBS 1.8.6.2 Cable Trays; WBS 1.8.6.3 Personnel, Safety, and Occupational Access; WBS 1.8.6.4 Assembly, Installation, and Maintenance Equipment; WBS 1.8.6.4.1 Target Chamber Service System; WBS 1.8.6.4.2 Target Bay Service Systems

Post-hoc analysis of randomised, placebo-controlled, double-blind study (MCI186-19) of edaravone (MCI-186) in amyotrophic lateral sclerosis.

Science.gov (United States)

Takei, Koji; Takahashi, Fumihiro; Liu, Shawn; Tsuda, Kikumi; Palumbo, Joseph

2017-10-01

Post-hoc analyses of the ALS Functional Rating Scale-Revised (ALSFRS-R) score data, the primary endpoint in the 24-week double-blind placebo-controlled study of edaravone (MCI186-19, NCT01492686), were performed to confirm statistical robustness of the result. The previously reported original analysis had used a last observation carried forward (LOCF) method and also excluded patients with fewer than three completed treatment cycles. The post-hoc sensitivity analyses used different statistical methods as follows: 1) including all patients regardless of treatment cycles received (ALL LOCF); 2) a mixed model for repeated measurements (MMRM) analysis; and 3) the Combined Assessment of Function and Survival (CAFS) endpoint. Findings were consistent with the original primary analysis in showing superiority of edaravone over placebo. We also investigated the distribution of change in ALSFRS-R total score across all patients in the study as well as which ALSFRS-R items and domains may have contributed to the overall efficacy findings. The distribution of changes in ALSFRS-R total score from baseline to the end of cycle 6 (ALL LOCF) shifted in favour of edaravone compared to placebo. Edaravone was descriptively favoured for each ALSFRS-R item and each of the four ALSFRS-R domains at the end of cycle 6 (ALL LOCF), suggesting a generalised effect of edaravone in slowing functional decline across all anatomical regions. The effect of edaravone appeared to be similar in patients with bulbar onset and limb onset. Together, these observations would be consistent with its putative neuroprotective effects against the development of oxidative damage unspecific to anatomical regions.

Safety, Pharmacokinetics, Immunogenicity, and Biodistribution of (186)Re-Labeled Humanized Monoclonal Antibody BIWA 4 (Bivatuzumab( in Patients with Early-Stage Breast Cancer.

NARCIS (Netherlands)

Koppe, M.; Schaijk, F. van; Roos, J.C.; Leeuwen, P.; Heider, K.H.; Kuthan, H.; Bleichrodt, R.P.

2004-01-01

The aim of this prospective study was to evaluate the safety, pharmacokinetics, immunogenicity, and biodistribution of (186)Re-labeled humanized anti-CD44v6 monoclonal antibody (MAb( BIWA 4 (Bivatuzumab( in 9 patients with early-stage breast cancer. Radioimmunoscintigraphy (RIS( was performed within

Testing of electroformed deposited iridium/powder metallurgy rhenium rockets

Science.gov (United States)

Reed, Brian D.; Dickerson, Robert

1996-01-01

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

God's punishment and public goods : A test of the supernatural punishment hypothesis in 186 world cultures.

Science.gov (United States)

Johnson, Dominic D P

2005-12-01

Cooperation towards public goods relies on credible threats of punishment to deter cheats. However, punishing is costly, so it remains unclear who incurred the costs of enforcement in our evolutionary past. Theoretical work suggests that human cooperation may be promoted if people believe in supernatural punishment for moral transgressions. This theory is supported by new work in cognitive psychology and by anecdotal ethnographic evidence, but formal quantitative tests remain to be done. Using data from 186 societies around the globe, I test whether the likelihood of supernatural punishment-indexed by the importance of moralizing "high gods"-is associated with cooperation.

Dosimetric comparison of {sup 90}Y, {sup 32}P, and {sup 186}Re radiocolloids in craniopharyngioma treatments

Energy Technology Data Exchange (ETDEWEB)

Sadeghi, Mahdi; Karimi, Elham; Hosseini, S. Hamed [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, P.O. Box 31485/498, Karaj (Iran, Islamic Republic of); Faculty of Engineering, Research and Science Campus, Islamic Azad University, P.O. Box 14155/4933, Tehran (Iran, Islamic Republic of)

2009-11-15

Purpose: In the radionuclide treatment of some forms of brain tumors such as craniopharyngiomas, the selection of the appropriate radionuclide for therapy is a key element in treatment planning. The aim was to study the influence by considering the beta-emitter radionuclide dose rate in an intracranial cyst. Methods: Dosimetry was performed using the MCNP4C radiation transport code. Analytical dosimetry was additionally performed using the Loevinger and the Berger formulas in the MATLAB software. Each result was compared under identical conditions. The advantages and disadvantages of using {sup 90}Y versus {sup 32}P and {sup 186}Re were investigated. Results: The dose rate at the inner surface of the cyst wall was estimated to be 400 mGy/h for a 1 MBq/ml concentration of {sup 90}Y. Under identical conditions of treatment, the corresponding dose rates were 300 mGy/h for {sup 32}P and 160 mGy/h for {sup 186}Re. For a well-defined cyst radius and identical wall thickness, higher dose rates resulted for {sup 90}Y. Conclusions: To achieve the same radiological burden, the required amount of physical activity of injectable solution is lower for {sup 32}P. This is found to be a consequence of both the radionuclide physical half-life and the pattern of energy deposition from the emitted radiation. According to the half-life and dose-rate results, {sup 90}Y would be a good substitute for {sup 32}P.

Coulomb excitation of /sup 182/ /sup 184/ /sup 186/W and /sup 166/Er with /sup 4/He and /sup 16/O ions

Energy Technology Data Exchange (ETDEWEB)

McGowan, F K; Milner, W T; Sayer, R O; Robinson, R L; Stelson, P H [Oak Ridge National Lab., Tenn. (USA)

1977-10-10

The Coulomb excitation reaction induced by /sup 4/He ions selectively excites 2/sup +/ and 3/sup -/ states by direct E2 and E3 Coulomb excitation. In this paper, new results are presented from ..gamma..-ray spectroscopy with 15 MeV /sup 4/He ions on a natural abundance target of W. In particular, a 3/sup -/ state in each isotope, /sup 182/ /sup 184/ /sup 186/W, was observed by direct E3 excitation. In addition to obtaining B(Elambda, 0 ..-->.. J = lambda for excitation of each state, information on the reduced transition probabilities for the different decay modes of these states is given. The Coulomb excitation probabilities of the 2'/sup +/ states at 786 keV in /sup 166/Er and at 737 keV in /sup 186/W were measured with /sup 16/O and /sup 4/He ions by the backscattered particle-gamma coincidence method in order to determine the static electric quadrupole moment Qsub(2'). For /sup 166/Er, Qsub(2')=2.11+-0.37 e.b which is in agreement with (Qsub(2'))sub(rot) and for /sup 186/W, Qsub(2')=1.17+-0.30 e.b which is in agreement with Kumar-Baranger model calculations and is significantly smaller than (Qsub(2'))sub(rot). This deviation of the measured Qsub(2') from (Qsub(2'))sub(rot) implies in the framework of the Kumar-Baranger calculations a strong coupling between ..beta..- and ..gamma..-vibrational bands. On the other hand, the observed upper limit for B(E2, 2'' ..-->.. 2') does not confirm this implication.

Sorption of technetium and its analogue rhenium on bentonite material under aerobic conditions

International Nuclear Information System (INIS)

Vinsova, H.; Koudelkova, M.; Konirova, R.; Vecernik, P.; Jedinakova-Krizova, V.

2003-01-01

The uptake of technetium on bentonite materials has been studied from the point of view of characterization of long-term radioactive elements behavior in nuclear waste repository. Bentonite R (locality Rokle, Czech Republic) and two types of model groundwater (granitic and bentonite) were selected for the sorption experiments. It is generally known that bentonite materials show an excellent cation-exchange capacity and, on the other hand, a poor uptake of anions. Technetium occurs under aerobic conditions in its most stable oxidation state (+VII) as pertechnetate, which makes a question of its sorption on bentonite more complex when compared with e.g. Cs + or Sr 2+ . To increase the K d values for technetium sorption on bentonite, it is necessary to carry out the experiments under anaerobic conditions in the presence of reducing agent, which is capable to lower the oxidation state of technetium which enables its successful immobilization. The aim of our research has been to find out the conditions suitable for the technetium sorption on selected bentonite under oxidizing conditions. The sorption experiments with Tc-99 on bentonite have been carried out by batch method. The influence of the addition of different materials (e.g. activated carbon, graphite, Fe 2+ , Fe) with bentonite, the effect of solid:aqueous phase ratio and a pH value on the percentage of technetium uptake and on the K d values were tested. Perrhenate was selected as an analogue of pertechnetate in non-active experiments of capillary electrophoresis (CE) and isotachophoresis (ITP). The percentage of rhenium sorbed on bentonite material was determined from the decrease of perrhenate peak area (CE) and from the shortening of the ITP zone corresponding to perrhenate. Both electromigration methods provided comparable results. The results obtained in this study with non-active material were compared to those of technetium acquired by radiometry and polarography. (authors)

Comparative study of the anchorage and the catalytic properties of nanoporous TiO2 films modified with ruthenium (II) and rhenium (I) carbonyl complexes

Science.gov (United States)

Oyarzún, Diego P.; Chardon-Noblat, Sylvie; Linarez Pérez, Omar E.; López Teijelo, Manuel; Zúñiga, César; Zarate, Ximena; Shott, Eduardo; Carreño, Alexander; Arratia-Perez, Ramiro

2018-02-01

In this article we study the anchoring of cis-[Ru(bpyC4pyr)(CO)2(CH3CN)2]2+, cis-[Ru(bpy)2(CO)2]2+ and cis-[Ru(bpyac)(CO)2Cl2], onto nanoporous TiO2 employing electropolymerization, electrostatic interaction and chemical bonding. Also, the [Re(bpyac)(CO)3Cl] rhenium(I) complex for chemical anchorage was analyzed. The characterization of TiO2/Ru(II) and TiO2/Re(I) nanocomposite films was performed by field emission scanning electron microscopy (FESEM), electron dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. In addition, for the more stable nanocomposites obtained, the catalytic properties (solar energy conversion and CO2 reduction) were evaluated. The efficiency improvement in redox process derived from the (photo)electrochemical evidence indicates that modified nanoporous TiO2 structures enhance the rate of charge transfer reactions.

Half-life measurements in doubly-odd sup(186,188,190)Au nuclei and the 188Hg -> Au decay

International Nuclear Information System (INIS)

Abreu, M.C.; Berg, V.; Fransson, K.; Hoeglund, A.; Oms, J.; Porquet, M.G.

1985-01-01

A level scheme has been established for 188 Hg -> Au decay which was studied with the online isotope separator ISOCELE. Precise conversion-electron measurements were performed with a semicircular magnetic spectrograph. The half-lives of the 16.0, 82.7 and 114.8 keV levels in 188 Au were measured with a lens electron spectrometer and reduced transition rates were deduced. Similarly the half-lives of the 36.1, 113.9, 227.7, 251.5, 288.0 and 363.6 keV levels in 186 Au and of the 28.9 and 171.5 keV levels in 190 Au were measured. Comparison of the reduced e.m. transition rates shows that a 1 + and a 2 - state have respectively the same structure in sup(186,) sup(188,) sup(190,) 192 Au, the same conclusion holding for the 1 - sub(g.s.) of sup(188,) sup(190,) 192 Au. Additional measurements in 189 , 191 Hg and 185 , 187 Au together with data from the literature enable us to interpret them as a coupling of certain quasiparticle states of neighbouring odd-A nuclei corresponding to oblate shapes. Indications are given that some other negative- and positive-parity states in 188 Au also belong to an oblate system. The nucleus 188 Au appears as the last of a series of doubly-odd gold nuclei where no shape coexistence has, as yet, been observed. (orig.)

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source

Energy Technology Data Exchange (ETDEWEB)

White, Shane A.; Landry, Guillaume; Reniers, Brigitte, E-mail: brigitte.reniers@maastro.nl [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands); Fonseca, Gabriel Paiva [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil); Holt, Randy; Rusch, Thomas [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States); Beaulieu, Luc [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada); Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

2014-06-15

Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. Methods: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (D{sub w,m}) and dose to medium (D{sub m,m}), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D{sub 90} to PTV was reduced by between ∼4% and ∼40%, depending on the

What can (^3He,d) tell us about the structure of ^186,188Os

Science.gov (United States)

Phillips, A. A.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Schumaker, M. A.; Svensson, C. E.; Wong, J.; Hertenberger, R.; Faestermann, T.; Krücken, R.; Wirth, H.-F.; Bettermann, L.; Braun, N.; Burke, D. G.

2008-10-01

The structure of Os nuclei are of interest for a number of reasons including a debate over the vibrational nature of the K^π=4^+ bands, and a shape transition from well-deformed prolate to γ-soft oblate as the number of neutrons increases. In order to investigate the structure of ^186,188Os, we have performed a (^3He,d) reaction on targets of ^185,187Re. The 30 MeV ^3He beams were obtained from the LMU/TUM Tandem Accelerator facility, and the Q3D spectrometer was used to analyze deuterons with 13 keV energy resolution. The absolute cross sections were measured at 9 angles from 5^o to 50^o up to ˜3 MeV in excitation energy. Fingerprint patterns are used to identify orbitals coupled to the 5/2^+[402]π target configuration.

Thermal neutron radiative capture cross-section of 186W(n, γ)187W reaction

International Nuclear Information System (INIS)

Tan, V H; Son, P N

2016-01-01

The thermal neutron radiative capture cross section for 186 W(n, γ) 187 W reaction was measured by the activation method using the filtered neutron beam at the Dalat research reactor. An optimal composition of Si and Bi, in single crystal form, has been used as neutron filters to create the high-purity filtered neutron beam with Cadmium ratio of R cd = 420 and peak energy E n = 0.025 eV. The induced activities in the irradiated samples were measured by a high resolution HPGe digital gamma-ray spectrometer. The present result of cross section has been determined relatively to the reference value of the standard reaction 197 Au(n, γ) 198 Au. The necessary correction factors for gamma-ray true coincidence summing, and thermal neutron self-shielding effects were taken into account in this experiment by Monte Carlo simulations. (paper)

Residency of rhenium and osmium in a heavy crude oil

Science.gov (United States)

DiMarzio, Jenna M.; Georgiev, Svetoslav V.; Stein, Holly J.; Hannah, Judith L.

2018-01-01

Rhenium-osmium (Re-Os) isotope geochemistry is an emerging tool for the study of oil formation and migration processes, and a new technology for petroleum exploration. Little is known, however, about the residency of Re and Os within asphaltene and maltene sub-fractions of crude oil. This information is crucial for understanding the 187Re-187Os radiometric clock held in petroleum systems and for interpreting geochronology for key processes such as oil formation, migration, and biodegradation. In this study, a heavy crude oil was separated into soluble (maltene, MALT) and insoluble (asphaltene, ASPH) fractions using n-heptane as the asphaltene-precipitating agent. The asphaltenes were separated sequentially into sub-fractions using two different solvent pairs (heptane-dichloromethane and acetone-toluene), and the bulk maltenes were separated into saturate, aromatic, and resin (SAR) fractions using open column chromatography. Each asphaltene and maltene sub-fraction was analyzed for Re and Os. The asphaltene sub-fractions and the bulk ASPH, MALT, and crude oil were analyzed for a suite of trace metals by ICP-MS. Our results show that Re and Os concentrations co-vary between the asphaltene sub-fractions, and that both elements are found mostly in the more polar and aromatic sub-fractions. Significant Re and Os are also present in the aromatic and resin fractions of the maltenes. However, each asphaltene and maltene sub-fraction has a distinct isotopic composition, and sub-fractions are not isochronous. This suggests that asphaltene sub-fractionation separates Re-Os complexes to the point where the isotopic integrity of the geochronometer is compromised. The mobility of individual Re and Os isotopes and the decoupling possibilities between radiogenic 187Os produced from 187Re remain elusive, but their recognition in this study is a critical first step. Re and Os correlate strongly with Mo and Cd in the asphaltene sub-fractions, suggesting that these metals occupy

Shape effects in the vicinity of the Z=82 line: study of the $\\beta$-decay of $^{182,184,186}$Hg

CERN Multimedia

This proposal is aimed at the study of the $\\beta$-decay of the neutron-­deficient $^{182,184,186}$Hg nuclei using the total absorption technique. Recent theoretical results show that, from measurements of the Gamow-­Teller strength distribution, the shapes of the ground states of the decaying Hg nuclei can be inferred. This study offers an independent way to study the phenomenon of shape coexistence in a region of particular interest.

Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA

International Nuclear Information System (INIS)

Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Alexander, C.W.; Hobbs, R.L.

1998-01-01

The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-11-05

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-11-09

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.

Electronic structures and properties of the rhenium alkoxy derivatives Re2O3(OMe)6, Re4O6(OMe)12, and ReMoO2(OMe)7

International Nuclear Information System (INIS)

Ermakov, A.I.; Belousov, V.V.; Drobot, D.V.; Shcheglov, P.A.

2006-01-01

The geometrical structures, charge distributions, dipole moments, frequencies of normal vibrations, NMR spectra, and total energies of the chemical bonds for the rhenium alkoxy derivatives Re 2 O 3 (OMe) 6 , Re 4 O 6 (OMe) 12 , and ReMoO 2 (OMe) 7 were calculated by the DFT-B3LYP and Hartree-Fock ab initio methods based on the effective core potential theory (LANL2DZ approximation) and the semiempirical PM3(tm) method. Two optimized structures of Re 2 O 3 (OMe) 6 with close energies were found to substantially differ in geometry, 1 H, 13 C, and 17 O NMR spectra, and dipole moment. Various characteristics of the electronic structures and the trans-effect of the ligands in the compounds under consideration were discussed [ru

Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

International Nuclear Information System (INIS)

Guerra Liberal, Francisco D. C.; Tavares, Adriana Alexandre S.; Tavares, João Manuel R. S.

2014-01-01

Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ( 32 P), strontium-89 ( 89 Sr), yttrium-90 ( 90 Y ), tin-117 ( 117m Sn), samarium-153 ( 153 Sm), holmium-166 ( 166 Ho), thulium-170 ( 170 Tm), lutetium-177 ( 177 Lu), rhenium-186 ( 186 Re), rhenium-188 ( 188 Re), and radium-223 ( 223 Ra). Results: 223 Ra alpha particles, 177 Lu beta minus particles, and 170 Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by 89 Sr and 153 Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than 177 Lu beta minus particles and 223 Ra alpha particles. Conclusions: 223 Ra and 177 Lu hold the highest potential for palliative treatment of bone metastases of all radioisotopes compared in this study. Data reported here may prompt future in vitro and in vivo

Determination of rhenium content in molybdenite by ICP-MS after separation of the major matrix by solvent extraction with N-benzoyl-N-phenylhydroxalamine.

Science.gov (United States)

Li, Jie; Zhong, Li-feng; Tu, Xiang-lin; Liang, Xi-rong; Xu, Ji-feng

2010-05-15

A simple and rapid analytical method for determining the concentration of rhenium in molybdenite for Re-Os dating was developed. The method used isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) after the removal of major matrix elements (e.g., Mo, Fe, and W) from Re by solvent extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform solution. The effect on extraction efficiency of parameters such as pH (HCl concentration), BPHA concentration, and extraction time were also assessed. Under the optimal experimental conditions, the validity of the separation method was accessed by measuring (187)Re/(185)Re values for a molybdenite reference material (JDC). The obtained values were in good agreement with previously measured values of the Re standard. The proposed method was applied to replicate Re-Os dating of JDC and seven samples of molybdenite from the Yuanzhuding large Cu-Mo porphyry deposit. The results demonstrate good precision and accuracy for the proposed method. The advantages of the method (i.e., simplicity, efficiency, short analysis time, and low cost) make it suitable for routine analysis.

The kinetics of hydrogen absorption/desorption within nanostructured composite Ni79.1Co18.6Cu2.3 alloy using resistometry

International Nuclear Information System (INIS)

Spasojević, M.; Maričić, A.; Ribić Zelenović, L.; Krstajić, N.; Spasojević, P.

2013-01-01

Highlights: ► Nanostructured Ni 79.1 Co 18.6 Cu 2.3 powder was obtained by electrochemical deposition. ► Correlation observed between electrical conductivity and absorbed hydrogen amount. ► Hydrogen absorption/desorption mechanism was determined. - Abstract: Ni 79.1 Co 18.6 Cu 2.3 powder was obtained by electrochemical deposition from an ammonium sulfate bath. The structure and surface morphology of the powder were detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The electrochemically obtained Ni 79.1 Co 18.6 Cu 2.3 alloy contained an amorphous phase and nanocrystals with an average size of 6.8 nm of FCC phase of the solid solution of cobalt and copper in nickel. Nanocrystals were characterized by a high average microstrain value and high minimum density of chaotically distributed dislocations. X-ray analysis also showed that powder hydrogenation at an elevated temperature of up to 200 °C did not change unit cell parameters and mean crystallite size value. SEM images show the formation of two shapes of powder particles: large cauliflower-like particles and small dendritic ones. Powder pressing at 10 MPa and at 25 °C gave samples that were analyzed for hydrogen absorption/desorption within the temperature range of 160–200 °C. Changes in electrical resistivity during absorption/desorption were monitored. The reciprocal value of resistivity (electrical conductivity) was found to increase linearly with increasing amount of absorbed hydrogen. The experimental results were used to propose an absorption/desorption mechanism. The adsorbed hydrogen molecule dissociates on alloy surface, forming adsorbed atoms. Adatoms penetrate and diffuse into the bulk of the alloy, simultaneously donating their electrons to the conduction band of the alloy. The increase in the concentration of free electrons induces a decrease in electrical resistivity. The overall absorption rate during initial absorption is determined by the

Evaluation of technetium-99m/rhenium labelled nucleoside analogues as potential radiotracers in oncology

International Nuclear Information System (INIS)

Desbouis, D.

2007-01-01

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 [ 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) 3 -core (M = 99m Tc, Re). The rhenium complex was found to be a selective competitive inhibitor of HSV1-TK (K i = 4.56 ± 0.11 μM). 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. [ 18 F]Fluorothymidine [ 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 [ 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 substrate activity with respect to recombinant hTKl. The phosphorylation rates of neutral and negative complexes were found to be similar, ranging between 15-16% with respect to thymidine

Os{sup 187}-isotope abundances in terrestrial and meteoritic osmium and an attempt to determine Re/Os-ages of iron meteorites; Anomalies dans l'abondance isotopique de l'osmium-187 dans l'osmium terrestre et meteoritique - Essai de determination de l'age des meteorites de fer au moyen du rapport Re/Os; Anomalii v rasprostranennosti izotopa osmiya-187 v zemnom i meteoritnom osmie i popytka opredeleniya vozrastov reniya/osmiya v zheleznykh meteoritakh; Anomalias en la abundancia isotopica del {sup 187}Os en el osmio terrestre y meteoritico. Ensayo para determinar la edad de los meteoritos de hierro por medio de la razon Re Os

Energy Technology Data Exchange (ETDEWEB)

Herr, W; Hoffmeister, W; Langhoff, J [Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut) Mainz, Federal Republic of Germany (Germany); Geiss, J; Hirt, B; Houtermans, F G [Physikalisches Institut der Universitaet Bern (Switzerland)

1962-01-15

The isotopic composition of a large number of Os-samples from terrestrial platinum ores and from iron meteorites has been investigated by mass-spectrometry. The observed isotope-ratios Os{sup 187}:Os{sup 186} in Os/Ir-ores and in Os-samples, extracted quantitatively from iron meteorites, vary in limit from 0.88 to 1.41. These variations may be explained by the production of radiogenic Os following the decay of Re{sup 187}, a natural {beta}-emitter with the lowest known {beta}-energy. Neutron activation analysis proves that Re and Os are common trace elements in iron meteorites. As dating of these bodies by conventional methods suffers from enormous difficulties, the application of the Re/Os method has been studied. From our experiments a primordial Os{sup 187}:Os{sup 186} ratio is assumed and 'minimum ages' are discussed. They differ widely and are found presumably in the range from 3.7 to 5.6x10{sup 9} yr. (author) [French] Les auteurs ont etudie au moyen de la spectrometrie de masse la composition isotopique d'un grand nombre d'echantillons d'osmium provenant de minerais terrestres de platine et d'holosideres. Le rapport isotopique osmium-187/ osmium-186 observe dans l'osmiure d'iridium et dans les echantillons d'osmium extraits en quantite mesurable des holosideres varie entre 0,88 et 1,41. Ces variations peuvent etre expliquees par la production d'osmium radiogenicjue resultant de la desintegration du rhenium-187, emetteur naturel de rayonnements beta connu comme ayant la plus faible energie beta. L'analyse par activation des neutrons montre que le rhenium et l'osmium se trouvent communement a l'etat de traces dans les holosideres. Comme il est extremement difficile d'evaluer l'age de ces corps en recourant aux methodes classiques, les auteurs du memoire ont examine la possibilite d'utiliser le rapport Re/Os. Apres avoir assume de leurs experiences le rapport osmium-187/osmium-186, ils examinent la question des . Ceux-ci different sensiblement et

Preliminary results of transarterial Rhenium-188 HDD Lipiodol in treatment of inoperable primary hepatocellular carcinoma

International Nuclear Information System (INIS)

Sundram, Felix

2004-01-01

Full text: In this paper we present our early experience with a new radio-conjugate, namely rhenium-188 HDD Lipiodol (Re-188 lipiodol). Imported radiopharmaceuticals are generally expensive, particularly for developing countries. A Tungsten (W-188-Re 188) generator obtained from ORNL (Oak Ridge National Laboratory, Tennessee, USA) allows us on-site production of a beta emitting therapeutic isotope (Re-188) for up to 6 months from a single generator. The objectives of this study were to establish the safety of trans-arterial Re-188 lipiodol in patients with inoperable HCC, and determine the adverse effects and efficacy for this radio-conjugate treatment in a multi-center study of patients with advanced HCC. A multi-center study was sponsored by the International Atomic Energy Agency (Vienna) to assess the safety and efficacy of trans-arterial Re-188 HDD conjugated lipiodol (radio-conjugate) in the treatment of patients with inoperable hepatocellular carcinoma (HCC), The radio-conjugate was prepared by using a HDD (4-hexadecyl 1-2, 9, 9-tetramethyl-4, 7-diaza-1, 10-decanethiol) kit developed in Korea, and lipiodol. Over a period of eighteen months seventy patients received at least one treatment of radio-conjugate. Some patients were re-treated if there was no evidence of disease progression. The level of radio-conjugate administered was based on radiation-absorbed dose to critical normal organs, calculated following a 'scout' dose of radio-conjugate. The organs at greatest risk for radiation toxicity are the normal liver, the lung and the bone marrow. A specially designed spreadsheet was used to determine maximum tolerated activity (MTA), defined as the amount of radioactivity calculated to deliver no more than 12 Gray (Gy) to lungs, or 30 Gy to liver, or 1.5 Gy to bone marrow. These doses have been found to be safe in multiple trials using external beam therapy and systemically administered radiopharmaceuticals. Patients were followed for at least twelve weeks

A phase 2 study of high-activity {sup 186}Re-HEDP with autologous peripheral blood stem cell transplant in progressive hormone-refractory prostate cancer metastatic to bone

Energy Technology Data Exchange (ETDEWEB)

O' Sullivan, J.M. [Queen' s University Belfast/Belfast City Hospital, Department of Oncology, Belfast (United Kingdom); Norman, A.R. [Royal Marsden Foundation NHS Trust, Department of Computing, Sutton, Surrey (United Kingdom); McCready, V.R.; Flux, G.; Buffa, F.M. [Royal Marsden Foundation NHS Trust, Department of Physics, Sutton, Surrey (United Kingdom); Johnson, B. [Royal Marsden Foundation NHS Trust, Bob Champion Unit, Sutton, Surrey (United Kingdom); Coffey, J.; Horwich, A.; Huddart, R.A.; Parker, C.C.; Dearnaley, D.P. [Royal Marsden Foundation NHS Trust, Academic Unit of Urology, Sutton, Surrey (United Kingdom); Cook, G. [Royal Marsden Foundation NHS Trust, Department of Nuclear Medicine, Sutton, Surrey (United Kingdom); Treleaven, J. [Royal Marsden Foundation NHS Trust, Department of Haematology, Sutton, Surrey (United Kingdom)

2006-09-15

We investigated the potential for improvement in disease control by use of autologous peripheral blood stem cell transplant (PBSCT) to permit administration of high activities of {sup 186}Re-hydroxyethylidene diphosphonate (HEDP) in patients with progressive hormone-refractory prostate cancer (HRPC). Eligible patients had progressive HRPC metastatic to bone, good performance status and minimal soft tissue disease. Patients received 5,000 MBq of {sup 186}Re-HEDP i.v., followed 14 days later by PBSCT. Response was assessed using PSA, survival, pain scores and quality of life. Thirty-eight patients with a median age of 67 years (range 50-77) and a median PSA of 57 ng/ml (range 4-3,628) received a median activity of 4,978 MBq {sup 186}Re-HEDP (range 4,770-5,100 MBq). The most serious toxicity was short-lived grade 3 thrombocytopenia in 8 (21%) patients. The median survival of the group is 21 months (95%CI 18-24 months) with Kaplan-Meier estimated 1- and 2-year survival rates of 83% and 40% respectively. Thirty-one patients (81%, 95% CI 66-90%) had stable or reduced PSA levels 3 months post therapy while 11 (29%, 95% CI 15-49%) had PSA reductions of >50% lasting >4 weeks. Quality of life measures were stable or improved in 27 (66%) at 3 months. We have shown that it is feasible and safe to deliver high-activity radioisotope therapy with PBSCT to men with metastatic HRPC. Response rates and survival data are encouraging; however, further research is needed to define optimal role of this treatment approach. (orig.)

Pyrazole complexes of rhenium. Synthesis and crystal structure of trans-[Re(O)(OMe)L4]Br2 · L · 4H2O (L - 3,5-dimethylpyrazole)

International Nuclear Information System (INIS)

Sokolov, M.N.; Fedorova, N.Eh.; Fedorov, V.E.; Virovets, A.V.; Nun'es, P.

2002-01-01

The first rhenium (V) mononuclear complex featuring composition [Re(O)(OMe)L 4 ]Br 2 (L = 3,5-dimethylpyrazole), which is resistant to hydrolysis in neutral aqueous solution, along with its molecular adduct of the composition [Re(O)(OMe)L 4 ]Br 2 · L · 4H 2 O were synthesized. The reaction products were characterized by the methods of elementary analysis, absorption spectroscopy in visible, UV and IR ranges, mass spectrometry. Besides, the adduct structure was studied by the method of X-ray diffraction analysis. It was ascertained that the adduct is crystallized in tetragonal crystal system with unit cell parameters as follows: a = 14.912 (3), c = 17.108 (4) A, sp. gr. I4/m, Z = 4. In the complex molecule linear grouping Re(O)(OMe)] 2+ (Re-O-C angle being equal to 180 deg) is coordinated by four L ligand molecules [ru

Differentiation of human induced pluripotent stem cells into insulin-like cell clusters with miR-186 and miR-375 by using chemical transfection.

Science.gov (United States)

Shaer, Anahita; Azarpira, Negar; Karimi, Mohammad Hosein

2014-09-01

Diabetes mellitus is characterized by either the inability to produce insulin or insensitivity to insulin secreted by the body. Islet cell replacement is an effective approach for diabetes treatment; however, it is not sufficient for all the diabetic patients. MicroRNAs (miRNAs) are a class of small noncoding RNAs that play an important role in mediating a broad and expanding range of biological activities, such as pancreas development. The present study aimed to develop a protocol to efficiently differentiate human induced pluripotent stem (iPS) cells into islet-like cell clusters (ILCs) in vitro by using miR-186 and miR-375. The human iPS colonies were transfected with hsa-miR-186 and hsa-miR-375 by using siPORT™ NeoFX™ Transfection Agent, and the differentiation was compared to controls. Total RNA was extracted 24 and 48 h after transfection. The gene expressions of insulin, NGN3, GLUT2, PAX4, PAX6, KIR6.2, NKX6.1, PDX1, Glucagon, and OCT4 were then evaluated through real-time qPCR. On the third day, the potency of the clusters was assessed in response to high glucose levels. Dithizone (DTZ) was used to identify the existence of the β-cells. Besides, the presence of insulin and NGN3 proteins was investigated by immunocytochemistry. Morphological changes were observed on the first day after the chemical transfection, and cell clusters were formed on the third day. The expression of pancreatic specific transcription factors was increased on the first day and significantly increased on the second day. The ILCs were positive for insulin and NGN3 proteins in the immunocytochemistry. Besides, the clusters were stained with DTZ and secreted insulin in glucose challenge test. Overexpression of miR-186 and miR-375 can be an alternative strategy for producing ILCs from the iPS cells in a short time. This work provides a new approach by using patient-specific iPSCs for β-cell replacement therapy in diabetic patients.

Analysis of a rhenium-osmium solid-solution spike by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Richardson, J.M.; Dickin, A.P.; McNutt, R.H.; McAndrew, J.I.; Beneteau, S.B.

1989-01-01

The rhenium-osmium decay scheme ( 187 Re → 187 Os) offers a unique opportunity to investigate the genesis of, and directly date, ultramafic rock, sulphide and platinum ore deposits. Inductively coupled plasma mass spectrometry (ICP-MS) is a viable method for Os isotopic analysis as it provides the high temperatures necessary to ionise Os. The sample can be introduced into the ICP mass spectrometer either by conventional nebulisation or by distillation using an Os ''generator''. Generator-mode analysis is superior to nebulisation because (i) the total number of counts is two orders of magnitude higher for a given sample size and (ii) Os oxidises readily to volatile OsO 4 , which has a boiling-point lower than most Re compounds, so that Os can be efficiently separated from 187 Re. The importance of Os loss during sample preparation was minimised by combining the sample powder with a powdered Re-Os isotopic spike prior to any chemical treatment. The spike is in a nickel sulphide matrix and was made by a thioacetamide co-precipitation of Os, Re and Ni followed by a fire assay. The 190 Os/ 192 Os ratio in this preparation is 51.5 ± 0.9, the 187 Os 188 Os ratio is 0.063 ± 0.006 and the 185 Re/ 187 Re ratio is 17.04 - + 0.41. These values are within the error limits quoted by the Oak Ridge National Laboratory and Techsnabexport, the suppliers of the metallic spikes. Parameters that significantly influence the Os analyses include the oxidising agent and the run temperature. The oxidising agent H 5 IO 6 is preferred to H 2 O 2 or HNO 3 as it has the highest electrode potential, provides a prolonged, consistent reaction and is more stable when stored. Chilling the sample and the H 5 IO 6 , initially retards uncontrolled OsO 4 emission. Heat applied later in the run releases OsO 4 and helps maintain a high count rate. Thus, OsO 4 can be generated in a steady, controllable and reproducible manner. (author)

Constraints on The Coupled Thermal Evolution of the Earth's Core and Mantle, The Age of The Inner Core, And The Origin of the 186Os/188Os Core(?) Signal in Plume-Derived Lavas

Science.gov (United States)

Lassiter, J. C.

2005-12-01

Thermal and chemical interaction between the core and mantle has played a critical role in the thermal and chemical evolution of the Earth's interior. Outer core convection is driven by core cooling and inner core crystallization. Core/mantle heat transfer also buffers mantle potential temperature, resulting in slower rates of mantle cooling (~50-100 K/Ga) than would be predicted from the discrepancy between current rates of surface heat loss (~44 TW) and internal radioactive heat production (~20 TW). Core/mantle heat transfer may also generate thermal mantle plumes responsible for ocean island volcanic chains such as the Hawaiian Islands. Several studies suggest that mantle plumes, in addition to transporting heat from the core/mantle boundary, also carry a chemical signature of core/mantle interaction. Elevated 186Os/188Os ratios in lavas from Hawaii, Gorgona, and in the 2.8 Ga Kostomuksha komatiites have been interpreted as reflecting incorporation of an outer core component with high time-integrated Pt/Os and Re/Os ( Brandon et al., 1999, 2003; Puchtel et al., 2005). Preferential partitioning of Os relative to Re and Pt into the inner core during inner core growth may generate elevated Re/Os and Pt/Os ratios in the residual outer core. Because of the long half-life of 190Pt (the parent of 186Os, t1/2 = 489 Ga), an elevated 186Os/188Os outer core signature in plume lavas requires that inner core crystallization began early in Earth history, most likely prior to 3.5 Ga. This in turn requires low time-averaged core/mantle heat flow (<~2.5 TW) or large quantities of heat-producing elements in the core. Core/mantle heat flow may be estimated using boundary-layer theory, by measuring the heat transported in mantle plumes, by estimating the heat transported along the outer core adiabat, or by comparing the rates of heat production, surface heat loss, and secular cooling of the mantle. All of these independent methods suggest time-averaged core/mantle heat flow of ~5

Development of methods for activity determination for radionuclides with double decay emission β- β+ / electron capture - application to the standardization of 192Ir, 152Eu and 186 Re

International Nuclear Information System (INIS)

Hilario, Katia Aparecida Fonseca

2002-01-01

In the present work alternative procedures have been developed for standardization of radionuclides with double decay, β - β + / electron capture using the 4πβ-γ coincidence technique, applying different systems. Two 4πβ-γ coincidence systems were used: one with a 4π gas-flow proportional counter coupled to a pair of NaI(Tl) scintillators and the other one with the same type of proportional counter coupled to HPGe detector. The radionuclides selected for this standardization, due to great interest in nuclear medicine, detector calibration and industrial radiography, were 192 Ir, 152 Eu and 186 Re. The first and the second were part of international comparisons sponsored by the Bureau International des Poids et Mesures (BIPM), France, who supplied the radioactive solution. For 186 Re, the gamma-ray emission probability per decay was measured by means REGe spectrometer system, previously calibrated with standard ampoules. All the uncertainties involved were treated rigorously, by means of covariance analysis. (author)

Improved radioimmunotherapy of hematologic malignancies

International Nuclear Information System (INIS)

Press, O.W.

1992-01-01

This research project proposes to develop novel new approaches of improving the radioimmunodetection and radioimmunotherapy of malignancies by augmenting retention of radioimmunoconjugates by tumor cells. The approaches shown to be effective in these laboratory experiments will subsequently be incorporated into out ongoing clinical trials in patients. Specific project objectives include: to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclonal antibodies targeting tumor-associated antigens on human leukemia and lymphoma cells; To examine the effects of lysosomotropic amines (e.g. chloroquine, amantadine), carboxylic ionophores (monensin, nigericin), and thioamides (propylthiouracil), on the retention of radiolabeled MoAbs by tumor cells; to examine the impact of newer radioiodination techniques (tyramine cellobiose, paraiodobenzoyl) on the metabolic degradation of radioiodinated antibodies; to compare the endocytosis, intracellular routing, and degradation of radioimmunoconjugates prepared with different radionuclides ( 131 Iodine, 111 Indium, 90 Yttrium, 99m Technetium, 186 Rhenium); and to examine the utility of radioimmunoconjugates targeting oncogene products for the radioimmunotherapy and radioimmunoscintigraphy of cancer

Radiosynoviorthesis: Radiochemical synovectomy in the treatment of rheumatoid arthritis

International Nuclear Information System (INIS)

Bandilla, K.

1981-01-01

Radioactive substances are used increasingly in the local treatment of chronic arthritis. Yttrium-90, beta-emitter, is used mainly for the knee joints, rhenium-186 for shoulder, elbows, hips and ankle joints and erbium-169 for the small joints of the hands. It is mandatory that the radioactive material is injected stricly interarticulary and the joint should be splinted for 4 days without weight bearing to avoid leakage. The success rate for knee joints is 55%. Patients with an early state of arthritis have a higher chance of improvement. Complications are reported as 2%, one third of the cases develop a symphatic effusion for 3 days after the injection. The use of radionuclides can lead to chromosome aberrations and the use of such materials should be limited to patients not younger than 40 years of age. Based on the current experience radiosynoviorthesis seems to be a true alternative for surgical synovectomy especially for the knee joints. (orig.) [de

New measurements of excitation functions of {sup 186}W(p,x) nuclear reactions up to 65 MeV. Production of a {sup 178}W/{sup 178m}Ta generator

Energy Technology Data Exchange (ETDEWEB)

Tárkányi, F.; Ditrói, F.; Takács, S. [Institute of Nuclear Research (ATOMKI), Debrecen (Hungary); Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Department, Vrije Universiteit Brussel, (VUB), Brussels (Belgium)

2017-01-15

New experimental excitation functions for proton induced reactions on {sup nat}W are presented in the 32–65 MeV energy range. The cross-sections for {sup nat}W(p,xn){sup 186,184m,184g,183,} {sup 182m,182g,181}Re, {sup nat}W(p,x){sup 178}W{sup ,} {sup nat}W(p,x){sup 183,182,} {sup 180m,} {sup 177,176,175}Ta, {sup 175}Hf and {sup 177}Lu were measured via an activation method by using a stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. The results were compared with predicted values obtained with the nuclear reaction code TALYS (results taken from the TENDL 2014 and TENDL 2015 on-line libraries). Production routes of the medically relevant radionuclides {sup 186}Re, the {sup 178}W → {sup 178}Ta generator and {sup 181}W are discussed.

Neutron capture cross section measurements and theoretical calculation for the {sup 186}W(n,γ){sup 187}W reaction

Energy Technology Data Exchange (ETDEWEB)

Al-abyad, Mogahed; Mohamed, Gehan Y. [Atomic Energy Authority, Cairo (Egypt). Experimental Nuclear Physics Dept.

2017-08-01

Neutron capture cross section (σ{sub 0}) and resonance integral (I{sub 0}) of the reaction {sup 186}W(n,γ){sup 187}W were measured experimentally using the research reactor (ETRR-2) and an Am-Be neutron source, also calculated using TALYS-1.6 code. The present results of σ{sub 0} are (39.08±2.6, 38.75±0.98 and 38.33 barn) and I{sub 0} are (418.5±74, 439.3±36 and 445.5 barn) by using the reactor, neutron source and TALYS-1.6, respectively. The present results are in acceptable agreement with most of the previous experimental and evaluated data as well as the theoretical calculations.

Rhenium-188 - advantages and clinical potential for use of a readily available, cost effective therapeutic radioisotope for applications in nuclear medicine, oncology and interventional cardiology

International Nuclear Information System (INIS)

Knapp, F.F. jr.

2002-01-01

Full text: Carrier-free rhenium-188 (Re-188) is readily available from the alumina-based tungsten-188/rhenium-188 generator system and has many attractive properties for a wide variety of therapeutic applications. The 16.9 h half-life, emission of the 2.2 MeV beta particle and versatile chemistry make Re-188 an important candidate for applications where high radiation penetration is required. In addition, emission of a gamma photon (155 KeV, 15 %) permits evaluation of biodistribution, pharmacokinetics and dosimetry estimates. The long physical half-life of the tungsten-188 (W-188) parent (t 1/2 69 days) and consistent generator performance - with high Re-188 yields and low W-188 parent breakthrough - result in an indefinite shelf-life of several months, dependent on the levels of Re-188 required. Post generator elution in-growth of 62 % of Re-188 after 24 hours in combination with high elution yields (75-85 %) result in 50 % daily yields of the maximal Re-188 available. In addition to research being conducted for the development of a wide variety of new therapeutic radiopharmaceuticals and devices, Re-188 is also being evaluated in physician-sponsored clinical trials in over 15 countries, with applications in nuclear medicine, oncology and interventional cardiology. One major current clinical application involves post-angiographic treatment of arterial segments following PTCA using Re-188 perrhenate or MAG3 liquid-filled balloons as an effective and cost-effective approach for inhibition of the hyperplastic response to vessel damage, which delivers uniform dose to the vessel wall. Re-188-HEDP is being used for palliation of metastatic bone pain palliation. This agent is readily prepared from a simple 'kit' and provides pain palliation as effective as other commercially available agents. The use of the Re-188-labeled Anti-NCA-95 antibody (BW 50/183; CD66 a,b,c,e) in conjunction which external beam irradiation and chemotherapy is an effective method for

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

Energy Technology Data Exchange (ETDEWEB)

Desbouis, D

2007-07-01

}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

Re4As6S3, a thio-spinel-related cluster system

DEFF Research Database (Denmark)

Besnard, Celine; Svensson, Christer; Ståhl, Kenny

2003-01-01

. The rhenium atoms form tetrahedral clusters linked via tetrahedral arsenic clusters to produce an NaCl-type arrangement. The oxidation state of rhenium is IV and the number of electrons shared by the rhenium atoms in the cluster is 12. The structure is based on an ordered defect thio-spinel A((1-x))B(2)X(4......) where the B-type atoms form tetrahedral clusters....

Phytoextraction of rhenium by lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) from alkaline soils amended with coal fly ash.

Science.gov (United States)

He, Honghua; Dong, Zhigang; Pang, Jiayin; Wu, Gao-Lin; Zheng, Jiyong; Zhang, Xingchang

2018-07-15

Coal fly ash (CFA) is an industrial waste generated in huge amounts worldwide, and the management of CFA has become an environmental concern. Recovery of valuable metals from CFA is one of the beneficial reuse options of CFA. Rhenium (Re) is one of the rarest metals in the Earth's crust and one of the most expensive metals of strategic significance in the world market. A CFA at the Jungar Thermal Power Plant, Inner Mongolia, China, contains more Re than two alkaline soils in the surrounding region. Pot experiments were undertaken to grow lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) in a loessial soil and an aeolian sandy soil amended with different rates (5%, 10%, 20%, and 40%) of CFA. The results show that plant growth was considerably enhanced and Re concentration in plants was significantly increased when CFA was applied to the alkaline soils at rates of ≤20%; while in some cases plant growth was also markedly enhanced by the 40% CFA treatment, which increased plant Re concentration the most of all treatments. Both lucerne and erect milkvetch showed potential for phytoextracting Re from CFA-amended alkaline soils. Using CFA for soil amendment not only offers a potential solution for the waste disposal problem of CFA, but the phytoextraction of Re by both lucerne and erect milkvetch may also bring an economic profit in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

Energy Technology Data Exchange (ETDEWEB)

Guerra Liberal, Francisco D. C., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, Adriana Alexandre S., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, João Manuel R. S., E-mail: tavares@fe.up.pt [Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

2014-11-01

Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ({sup 32}P), strontium-89 ({sup 89}Sr), yttrium-90 ({sup 90}Y ), tin-117 ({sup 117m}Sn), samarium-153 ({sup 153}Sm), holmium-166 ({sup 166}Ho), thulium-170 ({sup 170}Tm), lutetium-177 ({sup 177}Lu), rhenium-186 ({sup 186}Re), rhenium-188 ({sup 188}Re), and radium-223 ({sup 223}Ra). Results: {sup 223}Ra alpha particles, {sup 177}Lu beta minus particles, and {sup 170}Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by {sup 89}Sr and {sup 153}Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than {sup 177}Lu beta minus particles and {sup 223}Ra alpha particles. Conclusions: {sup 223}Ra and {sup 177}Lu hold the highest potential for palliative treatment of bone metastases of all

Investigation into complexing in Re7-H3O+-SO42--H2O system

International Nuclear Information System (INIS)

Sinyakova, G.S.

1979-01-01

Using the methods of spectrophotometry and conductometry it is shown, that in the ReO 4 - -H 3 O + -SO 4 2- -H 2 O system interaction between rhenium (7) and sulfuric acid takes place in a wide concentration range. In low-acid solutions at pH 2.0-0.9 rhenium(7) complex with proton is formed at the ratio of 1:1 with lgK 1 =3.30+-0.02. In 1-10 mol. sulfuric acid observed is consecutive complexing at the rhenium(7) - sulfuric acid ratio in the complex of 1:1 and 1:2 respectively with lgK 2 =0.93+-0.13 and lgK 3 =0.34+-0.03. At the background of concentrated perchloric acid rhenium (7) and sodium sulfate form two complex compounds at rhenium (7) - sodium sulfate ratio of 1:1 and 1:2 with lgK 1 =1.86+-0.02 and lgK 2 =2.35+-0.03

Functional activity of the rats’ hepatocytes under cancerogenesis

Directory of Open Access Journals (Sweden)

V. V. Ivchuk

2007-10-01

Full Text Available Enzymatic activity in rat’s hepatocytes under carcinoma Geuren T8 development as well as after introduction of rhenium compounds and cis-platin were studied. It has been determined that the decrease of enzymatic activity contrary to the control animals has been observed under simultaneous injection of cis-platin and cluster rhenium compounds in a liposome form. That confirms possible hepatoprotective properties of the rhenium compounds.

Rhenium-188 Lipiodol Therapy of Hepatocellular Carcinoma: Results of a multicentre-multinational study

International Nuclear Information System (INIS)

Padhy, A.K.; Bernal, P.; Buscombe, R.J.

2007-01-01

Full text: A multi-centre study was sponsored by the IAEA to assess the safety and efficacy of trans-arterial Rhenium-188 HDD Lipiodol in the treatment of inoperable Hepatocellular Carcinoma. The radioconjugate was prepared by using an HDD kit and Lipiodol. Over three years, 185 patients received at least one treatment. The dose administered was based on radiation absorbed dose to critical normal organs, calculated following a ''scout'' dose (approximately 4 mCi) of radioconjugate. The organs at greatest risk for radiation toxicity are the liver, the lung and the bone marrow. An Excel spreadsheet was used to determine maximum tolerated activity, defined as the amount of radioactivity calculated to deliver no more than 12 Gy to lungs, 30 Gy to liver, or 1.5 Gy to bone marrow. A single treatment was given to 134 patients, 42 patients received two doses, 8 received three and one patient received four treatments. The total injected activity including the scout dose during the first treatment ranged from 21 to 364 mCi (average 108 mCi). Patients were followed for at least l2 weeks after therapy. The clinical parameters evaluated included toxicity, response as determined objectively by contrast enhanced computed tomography, palliation of symptoms, overall survival, performance status (Karnofsky), and hepatic function (Child's classification). Liver function tests, serum alpha-fetoprotein (AFP) levels and complete blood counts were done at each follow-up visit. Side effects were minimal and usually presented as loss of appetite, right hypochondrial discomfort and low-grade fever. Liver function tests at 24 and 72 hours showed no significant changes and complete blood counts at 1 week, 4 weeks and 12 weeks showed no changes (no bone marrow suppression). Data on largest tumour diameter after therapy and/or tumour response as evaluated from CT scans are available for 88 patients. Complete disappearance of tumour was recorded in 3 (3%), partial response in 19 (22%), stable

Challenging fission dynamics around the barrier: The case of {sup 34}S + {sup 186}W

Energy Technology Data Exchange (ETDEWEB)

Kozulin, E.M.; Itkis, I.; Knyazheva, G.; Novikov, K.; Bogachev, A.; Dmitriev, S.; Loktev, T. [Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna (Russian Federation); Vardaci, E. [Dipartamento di Scienze Fisiche, Napoli (Italy); INFN, Napoli (Italy); Harca, I.M. [Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna (Russian Federation); Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Bucharest - Magurele (Romania); Universitatea din Bucuresti, Facultatea de Fizica, Bucharest (Romania); Schmitt, C.; Piot, J. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, Caen (France); Azaiez, F.; Matea, I.; Verney, D.; Gottardo, A. [Universite Paris-Saclay, IPN, CNRS/IN2P3, Orsay (France); Dorvaux, O. [Universite de Strasbourg, IPHC, CNRS/IN2P3, Strasbourg (France); Chubarian, G. [Texas A and M University, Cyclotron Institute, College Station, TX (United States); Trzaska, W.H. [Accelerator Laboratory of University of Jyvaskyla (JYFL), Jyvaskyla (Finland); Hanappe, F. [Universite Libre de Bruxelles (ULB), Bruxelles (Belgium); Borcea, C.; Calinescu, S.; Petrone, C. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Bucharest - Magurele (Romania)

2016-09-15

The current status of fission dynamics studies in heavy-ion collisions around the Coulomb barrier is illustrated with the {sup 34}S + {sup 186}W reaction. The fission-fragment mass and total kinetic energy were measured at the ALTO facility at IPN Orsay, France, with a dedicated set-up using the (v, E) approach. The measurement reveals the presence of an asymmetric fission component on top of a predominantly symmetric distribution. The asymmetric structure, pointed out for the first time, is discussed along with results of previous experiments studying the same reaction. While these analyses suggested the contribution from either quasi-fission or pre-equilibrium fission, we offer an alternative interpretation, in terms of shell-driven compound-nucleus fission. The present measurement demonstrates the critical influence of resolution when addressing puzzling cases, situated at the crossroads of the various channels opened in a heavy-ion collision. Current status in the field clearly calls for innovative measurements involving manifold correlations and new observables. The outcome of the attempt done in this work in this direction, based on the coincident measurement of prompt γ-rays is reported, and encouraging perspectives are discussed. (orig.)

Blood superoxiddismutase and catalase: enzymes activity under oxidative stress conditions

OpenAIRE

Каріна Леонідівна Шамелашвілі; Інга Володимирівна Леус; Тетяна Іванівна Сергієнко; Марина Вячеславівна Горіла; Наталія Іванівна Штеменко

2015-01-01

The activity of catalase and superoxide dismutase depends not only on the used compounds of rhenium, and also on their dimensional structure and form of applying. It is established that the cis- and trans-isomers of complex compounds of rhenium did countervailing effect on superoxide dismutase and catalase activities. Cis-isomers of Rhenium dycarboxylats agreed increased activity of superoxide dismutase and catalase. While under the action of trans-isomers, where increased activity of superox...

Bimetallic Catalysts and Platinum Surfaces Studied by X-ray Absorption Spectroscopy and Scanning Tunnelling Microscopy

Energy Technology Data Exchange (ETDEWEB)

Roenning, Magnus

2000-07-01

Bimetallic catalyst systems used in Fischer-Tropsch synthesis (Co-Re/Al{sub 2}O{sub 3}) and in the naphtha reforming process (Pt-Re/Al{sub 2}O{sub 3}) have been studied in situ using X-ray absorption spectroscopy (EXAFS). Additionally, the adsorption of ethene on platinum single crystal surfaces has been investigated using scanning tunnelling microscopy. In situ EXAFS at the cobalt K absorption edge have been carried out at 450{sup o}C on the hydrogen reduction of a rhenium-promoted Co{sub 3}O{sub 4}/Al{sub 2}O{sub 3} catalyst. Reductions carried out using 100% hydrogen and 5% hydrogen in helium gave different results. Whereas the reduction using dilute hydrogen leads to bulk-like metallic cobalt particles (hcp or fcc), reaction with pure hydrogen yields a more dispersed system with smaller cobalt metal particles (< 40 A). The results are rationalised in terms of different degrees of reoxidation of cobalt by the higher and lower concentrations of water generated during the reduction of cobalt oxide by 100% and 5% hydrogen, respectively. Additionally, in both reduction protocols a small fraction (3 -4 wt%) of the cobalt content is randomly dispersed over the tetrahedral vacancies of the alumina support. This dispersion occurs during reduction and not calcination. The cobalt in these sites cannot be reduced at 450 {sup o}C. The local environments about the rhenium atoms in Co-Re/{gamma}-A1{sub 2}O{sub 3} catalyst after different reduction periods have been studied by X-ray absorption spectroscopy. A bimetallic catalyst containing 4.6 wt% cobalt and 2 wt% rhenium has been compared with a corresponding monometallic sample with 2 wt% rhenium on the same support. The rhenium L{sub III} EXAFS analysis shows that bimetallic particles are formed after reduction at 450{sup o}C with the average particle size being 10-15 A. Rhenium is shown to be reduced at a later stage than cobalt. The fraction of cobalt atoms entering the support obstructs the access to the support for the

Probing surface sites of TiO2: reactions with [HRe(CO)5] and [CH3Re(CO)5].

Science.gov (United States)

Lobo-Lapidus, Rodrigo J; Gates, Bruce C

2010-10-04

Two carbonyl complexes of rhenium, [HRe(CO)(5)] and [CH(3)Re(CO)(5)], were used to probe surface sites of TiO(2) (anatase). These complexes were adsorbed from the gas phase onto anatase powder that had been treated in flowing O(2) or under vacuum to vary the density of surface OH sites. Infrared (IR) spectra demonstrate the variation in the number of sites, including Ti(+3)-OH and Ti(+4)-OH. IR and extended X-ray absorption fine structure (EXAFS) spectra show that chemisorption of the rhenium complexes led to their decarbonylation, with formation of surface-bound rhenium tricarbonyls, when [HRe(CO)(5)] was adsorbed, or rhenium tetracarbonyls, when [CH(3)Re(CO)(5)] was adsorbed. These reactions were accompanied by the formation of water and surface carbonates and removal of terminal hydroxyl groups associated with Ti(+3) and Ti(+4) ions on the anatase. Data characterizing the samples after adsorption of [HRe(CO)(5)] or [CH(3)Re(CO)(5)] determined a ranking of the reactivity of the surface OH sites, with the Ti(+3)-OH groups being the more reactive towards the rhenium complexes but the less likely to be dehydroxylated. The two rhenium pentacarbonyl probes provided complementary information, suggesting that the carbonate species originate from carbonyl ligands initially bonded to the rhenium and from hydroxyl groups of the titania surface, with the reaction leading to the formation of water and bridging hydroxyl groups on the titania. The results illustrate the value of using a family of organometallic complexes as probes of oxide surface sites.

The health benefits of secondary education in adolescents and young adults: An international analysis in 186 low-, middle- and high-income countries from 1990 to 2013

OpenAIRE

Russell M. Viner; Dougal S. Hargreaves; Joseph Ward; Chris Bonell; Ali H. Mokdad; George Patton

2017-01-01

Background: The health benefits of secondary education have been little studied. We undertook country-level longitudinal analyses of the impact of lengthening secondary education on health outcomes amongst 15-24 year olds. Methods: Exposures: average length of secondary and primary education from 1980 to 2013. Data/Outcomes: Country level adolescent fertility rate (AFR), HIV prevalence and mortality rate from 1989/90 to 2013 across 186 low-, middle- and high-income countries. Analysi...

Non-carrier-added 186,188Re labeled 17α-ethynylestradiol: a potential breast cancer imaging and therapy agent

International Nuclear Information System (INIS)

Fassbender, M.E.; Phillips, Dennis R.; Peterson, E.J.; Ott, K.C.; Arterburn, J.B.

2001-01-01

Receptor-targeted radiopharmaceuticals constitute potential agents for the diagnosis and therapy of cancer. Breast cancer is the most prevalent form of diagnosed cancer in women in the United States, and it accounts for the second highest number of cases of cancer fatalities (1). In Approximately two-thirds of the breast tumors, estrogen and progesterone steroid hormone receptors can be found. Such tumors can often be treated successfully with anti-estrogen hormone therapy (2). Hence, the ability to determine the estrogen receptor (ER) contend of the breast tumor is essential for making the most appropriate choice of treatment for the patient. Along with this diagnostic aspect, steroid-based radiopharmaceuticals with high specific activity offer an encouraging prospect for therapeutic applications: 186,188 Re labeled steroids binding to receptors expressed by cancer cells appear to be potential agents for the irradiation of small to medium-sized tumors. 186 Re has been regarded as an ideal radionuclide for radiotherapy due to its appropriate half-live of 90 h and β-energy of 1.07 MeV. Moreover, the γ-emission of 137 keV that allows in vivo imaging while in therapy is an additional bonus. 188 Re is obtained from a 188 W/ 188 Re radionuclide generator system, representing an advantage for availability at radiopharmacy laboratory by daily elution. In addition, 188 Re emits high energy beta particles with an average energy of 769 keV, and the emission of the 155 keV allows simultaneous imaging for biodistribution evaluation in vivo. In order to avoid competitive saturation of the binding sites of the ligand receptor, Re labeled steroids with high specific activity are required, and the removal of all excess unlabeled ligands is mandatory. 188 Re is eluted from a 188 W/ 188 Re generator produced and provided by Oak Ridge National Laboratory (3). This paper outlines the solid phase-supported preparation of an n.c.a. ( 188 Re)Re-imido estradiol compound. The

The kinetics of hydrogen absorption/desorption within nanostructured composite Ni{sub 79.1}Co{sub 18.6}Cu{sub 2.3} alloy using resistometry

Energy Technology Data Exchange (ETDEWEB)

Spasojevic, M., E-mail: ljiljana.spasojevic51@yahoo.com [Joint Laboratory for Advanced Materials of the Serbian Academy of Science and Arts, Section for Amorphous Systems, Svetog Save 65, 32000 Cacak, Republic of Serbia (Serbia); Faculty of Agronomy Cacak, University of Kragujevac, Cara Dusana 34, 32000 Cacak, Republic of Serbia (Serbia); Maricic, A. [Joint Laboratory for Advanced Materials of the Serbian Academy of Science and Arts, Section for Amorphous Systems, Svetog Save 65, 32000 Cacak, Republic of Serbia (Serbia); Ribic Zelenovic, L. [Joint Laboratory for Advanced Materials of the Serbian Academy of Science and Arts, Section for Amorphous Systems, Svetog Save 65, 32000 Cacak, Republic of Serbia (Serbia); Faculty of Agronomy Cacak, University of Kragujevac, Cara Dusana 34, 32000 Cacak, Republic of Serbia (Serbia); Krstajic, N.; Spasojevic, P. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Republic of Serbia (Serbia)

2013-02-25

Highlights: Black-Right-Pointing-Pointer Nanostructured Ni{sub 79.1}Co{sub 18.6}Cu{sub 2.3} powder was obtained by electrochemical deposition. Black-Right-Pointing-Pointer Correlation observed between electrical conductivity and absorbed hydrogen amount. Black-Right-Pointing-Pointer Hydrogen absorption/desorption mechanism was determined. - Abstract: Ni{sub 79.1}Co{sub 18.6}Cu{sub 2.3} powder was obtained by electrochemical deposition from an ammonium sulfate bath. The structure and surface morphology of the powder were detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The electrochemically obtained Ni{sub 79.1}Co{sub 18.6}Cu{sub 2.3} alloy contained an amorphous phase and nanocrystals with an average size of 6.8 nm of FCC phase of the solid solution of cobalt and copper in nickel. Nanocrystals were characterized by a high average microstrain value and high minimum density of chaotically distributed dislocations. X-ray analysis also showed that powder hydrogenation at an elevated temperature of up to 200 Degree-Sign C did not change unit cell parameters and mean crystallite size value. SEM images show the formation of two shapes of powder particles: large cauliflower-like particles and small dendritic ones. Powder pressing at 10 MPa and at 25 Degree-Sign C gave samples that were analyzed for hydrogen absorption/desorption within the temperature range of 160-200 Degree-Sign C. Changes in electrical resistivity during absorption/desorption were monitored. The reciprocal value of resistivity (electrical conductivity) was found to increase linearly with increasing amount of absorbed hydrogen. The experimental results were used to propose an absorption/desorption mechanism. The adsorbed hydrogen molecule dissociates on alloy surface, forming adsorbed atoms. Adatoms penetrate and diffuse into the bulk of the alloy, simultaneously donating their electrons to the conduction band of the alloy. The increase in the concentration of free

Regulation of salt marsh mosquito populations by the 18.6-yr lunar-nodal cycle.

Science.gov (United States)

Rochlin, Ilia; Morris, James T

2017-08-01

The 18.6-yr lunar-nodal cycle drives changes in tidal amplitude globally, affecting coastal habitat formation, species and communities inhabiting rocky shores, and salt marsh vegetation. However, the cycle's influence on salt marsh fauna lacked sufficient long-term data for testing its effect. We circumvented this problem by using salt marsh mosquito records obtained over a period of over four decades in two estuaries in the northeastern USA. Salt marsh mosquito habitat is near the highest tide level where the impact of the nodal cycle on flood frequency is greatest. Wavelet spectral and cross-correlation analyses revealed periodicity in salt marsh mosquito abundance that was negatively correlated with tidal amplitude. Tidal amplitude was a significant predictor of salt marsh mosquito abundance with the cycle maxima coinciding with lower mosquito populations, possibly due to access by predatory fish. However, these effects were detected only at the location with extensive salt marsh habitat and astronomical tides and were weakened or lacked significance at the location with small microtidal salt marshes and wind-driven tides. Mosquitoes can serve as proxy indicators for numerous invertebrate species on the salt marsh. These predictable cycles and their effects need to be taken into consideration when investigating, restoring, or managing intertidal communities that are also facing sea-level rise. © 2017 by the Ecological Society of America.

Investigation into complexing in Re/sup 7/-H/sub 3/O/sup +/-SO/sub 4//sup 2 -/-H/sub 2/O system

Energy Technology Data Exchange (ETDEWEB)

Sinyakova, G S [AN Latvijskoj SSR, Riga. Inst. Neorganicheskoj Khimii

1979-10-01

Using the methods of spectrophotometry and conductometry it is shown, that in the ReO/sub 4//sup -/-H/sub 3/O/sup +/-SO/sub 4//sup 2 -/-H/sub 2/O system interaction between rhenium (7) and sulfuric acid takes place in a wide concentration range. In low-acid solutions at pH 2.0-0.9 rhenium(7) complex with proton is formed at the ratio of 1:1 with lgK/sub 1/=3.30+-0.02. In 1-10 mol. sulfuric acid observed is consecutive complexing at the rhenium(7) - sulfuric acid ratio in the complex of 1:1 and 1:2 respectively with lgK/sub 2/=0.93+-0.13 and lgK/sub 3/=0.34+-0.03. At the background of concentrated perchloric acid rhenium (7) and sodium sulfate form two complex compounds at rhenium (7) - sodium sulfate ratio of 1:1 and 1:2 with lgK/sub 1/=1.86+-0.02 and lgK/sub 2/=2.35+-0.03.

Materials and fabrication processes for operation in hot hydrogen

International Nuclear Information System (INIS)

Tuffias, R.H.; Duffy, A.J.; Arrieta, V.M.; Abrams, W.M.; Benander, R.E.

1997-01-01

Operation in hot (2500 endash 3000 K) hydrogen severely limits the choice of structural materials. Rhenium is nonreactive with and has low permeability to hydrogen, and has sufficient strength up to 2800 K. Carbon, in the form of graphite or carbon composites, has excellent high temperature strength but reacts with hydrogen to form methane at a rapid rate above 2000 K. The carbides of zirconium, niobium, hafnium, and tantalum are nonreactive with and have low permeability to hydrogen, but they can be reliably fabricated only in the form of coatings. In order to demonstrate the Integrated Solar Upper Stage (ISUS) solar-thermal propulsion concept, rhenium and rhenium-coated graphite were chosen as the structural materials for the receiver-absorber-converter (RAC) component of the ISUS system. Several methods were investigated for fabricating the rhenium parts and coatings, with chemical vapor deposition (CVD) and Ultramet chosen as the most likely process and company for success. The CVD or rhenium and other refractory materials were thus applied to the ISUS program for fabrication of the RAC subsystem. copyright 1997 American Institute of Physics

Hydrocarbon conversion with an attenuated superactive multimetallic catalytic composite

International Nuclear Information System (INIS)

Antos, G.J.

1981-01-01

Hydrocarbons are converted by contacting them at hydrocarbon conversion conditions with a novel attenuated superactive multimetallic catalytic composite comprising a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of a platinum group component, which is maintained in the elemental metallic state during the incorporation and pyrolysis of the rhenium carbonyl component, and of an iron component. In a highly preferred embodiment, this novel catalytic composite also contains a catalytically effective amount of a halogen component. The platinum group component, pyrolyzed rhenium carbonyl component, iron component and optional halogen component are preferably present in the multimetallic catalytic composite in amounts, calculated on an elemental basis, corresponding to about 0.01 to about 2 wt. % platinum group metal, about 0.01 to about 5 wt. % rhenium, about 0.005 to about 4 wt. % iron and about 0.1 to about 5 wt. % halogen. A key feature associated with the preparation of the subject catalytic composite is reaction of a rhenium carbonyl complex with a porous carrier material containing a uniform dispersion of an iron component and of a platinum group component maintained in the elemental state, whereby the interaction of the rhenium moiety with the platinum group moiety is maximized due to the platinophilic (i.e., platinum-seeking) propensities of the carbon monoxide ligands associated with the rhenium reagent. A specific example of the type of hydrocarbon conversion process disclosed herein is a process for the catalytic reforming of a low octane gasoline fraction wherein the gasoline fraction and a hydrogen stream are contacted with the attenuated superactive multimetallic catalytic composite at reforming conditions

Blood superoxiddismutase and catalase: enzymes activity under oxidative stress conditions

Directory of Open Access Journals (Sweden)

Каріна Леонідівна Шамелашвілі

2015-05-01

Full Text Available The activity of catalase and superoxide dismutase depends not only on the used compounds of rhenium, and also on their dimensional structure and form of applying. It is established that the cis- and trans-isomers of complex compounds of rhenium did countervailing effect on superoxide dismutase and catalase activities. Cis-isomers of Rhenium dycarboxylats agreed increased activity of superoxide dismutase and catalase. While under the action of trans-isomers, where increased activity of superoxide dismutase, catalase activity decreased

Constraints on the coupled thermal evolution of the Earth's core and mantle, the age of the inner core, and the origin of the 186Os/188Os “core signal” in plume-derived lavas

Science.gov (United States)

Lassiter, J. C.

2006-10-01

The possibility that some mantle plumes may carry a geochemical signature of core/mantle interaction has rightly generated considerable interest and attention in recent years. Correlated 186Os- 187Os enrichments in some plume-derived lavas (Hawaii, Gorgona, Kostomuksha) have been interpreted as deriving from an outer core with elevated Pt/Os and Re/Os ratios due to the solidification of the Earth's inner core (c.f., [A.D. Brandon, R.J. Walker, The debate over core-mantle interaction, Earth Planet. Sci. Lett. 232 (2005) 211-225.] and references therein). Conclusive identification of a "core signal" in plume-derived lavas would profoundly influence our understanding of mantle convection and evolution. This paper reevaluates the Os-isotope evidence for core/mantle interaction by examining other geochemical constraints on core/mantle interaction, geophysical constraints on the thermal evolution of the outer core, and geochemical and cosmochemical constraints on the abundance of heat-producing elements in the core. Additional study of metal/silicate and sulfide/silicate partitioning of K, Pb, and other trace elements is needed to more tightly constrain the likely starting composition of the Earth's core. However, available data suggest that the observed 186Os enrichments in Hawaiian and other plume-derived lavas are unlikely to derive from core/mantle interaction. 1) Core/mantle interaction sufficient to produce the observed 186Os enrichments would likely have significant effects on other tracers such as Pb- and W-isotopes that are not observed. 2) Significant partitioning of K or other heat-producing elements into the core would produce a "core depletion" pattern in the Silicate Earth very different from that observed. 3) In the absence of heat-producing elements in the core, core/mantle heat flow of ˜ 6-15 TW estimated from several independent geophysical constraints suggests an inner core age (< ˜ 2.5 Ga) too young for the outer core to have developed a significant

Probing the remarkable thermal kinetics of visual rhodopsin with E181Q and S186A mutants

Science.gov (United States)

Guo, Ying; Hendrickson, Heidi P.; Videla, Pablo E.; Chen, Ya-Na; Ho, Junming; Sekharan, Sivakumar; Batista, Victor S.; Tully, John C.; Yan, Elsa C. Y.

2017-06-01

We recently reported a very unusual temperature dependence of the rate of thermal reaction of wild type bovine rhodopsin: the Arrhenius plot exhibits a sharp "elbow" at 47 °C and, in the upper temperature range, an unexpectedly large activation energy (114 ± 8 kcal/mol) and an enormous prefactor (1072±5 s-1). In this report, we present new measurements and a theoretical model that establish convincingly that this behavior results from a collective, entropy-driven breakup of the rigid hydrogen bonding networks (HBNs) that hinder the reaction at lower temperatures. For E181Q and S186A, two rhodopsin mutants that disrupt the HBNs near the binding pocket of the 11-cis retinyl chromophore, we observe significant decreases in the activation energy (˜90 kcal/mol) and prefactor (˜1060 s-1), consistent with the conclusion that the reaction rate is enhanced by breakup of the HBN. The results provide insights into the molecular mechanism of dim-light vision and eye diseases caused by inherited mutations in the rhodopsin gene that perturb the HBNs.

Alpha Particle Therapy in Metastatic Prostate Cancer

International Nuclear Information System (INIS)

O’Sullivan, Joe

2013-01-01

Metastatic castrate resistant prostate cancer (CRPC) is a leading cause of cancer mortality among men in western countries. Although nearly 85% of patients present with localised disease, up to 40% will eventually develop metastatic disease during the course of illness. Of men dying from prostate cancer, more than 90% have bone metastases many with no other significant metastatic sites. Symptoms related to bone metastases and skeletal related events (SREs) account for the major cause of morbidity in these patients. Bone-seeking radionuclides have been used in the treatment of prostate cancer bone metastases for many years. The first bone seeking radionuclide drug approved by the FDA was Strontium-89. Other agents have also been used including Samarium-153 EDTMP, Rhenium-186 (-188)-HEDP. These radionuclides are all emit shortrange therapeutic beta radiation with bone marrow as the dose limiting toxicity. There is strong clinical trial evidence of benefit for these radionuclides in reducing pain in advanced prostate cancer; however, none of the drugs has been shown to improve survival, albeit none of the clinical trials were powered to detect differences in survival

In-house Preparation of 188W/188Re Generators

International Nuclear Information System (INIS)

Sriwiang, Wiranee; Minsakorn, Napharat; Wardwilai, Charudej; Yindirum, Chareon; Sangsuriyan, Jatupol

2007-08-01

Full text: Low activity 188W/188Re generators were developed for the purpose of routinely supplying rhenium-188 for laboratory experiments and research works. Chromatography technology was applied in the construction of the generators. The chromatography columns containing 1.74 g alumina (Al2O3) were housed in plastic (PE) shielding inside the 30mm thick lead shield. Three generators were loaded with three different 188W activities; 25mCi (RG1), 25 mCi (RG2) and 50 mCi (RG3). Generator performances were determined in terms of elution yields, radiochemical purity, Al-breakthrough, 188W-breakthrough, and radionuclidic purity of the eluted products. These generators can be used for more than 6 months with average elution yields greater than 90 %. Radiochemical purity of 188ReO4- was high (> 99.7 % by ITLC), low level of 188W -breakthrough and low contamination of 192Ir and 191Os. There were only less than 1 ppm of 186W carrier and less than 3 ppm of Al-breakthrough. Key words: 188W/188Re, Generator, 188Re, Radionuclide

Radionuclides and the normal bone scan

International Nuclear Information System (INIS)

Mettler, F.A. Jr.; Monsein, L.; Rosenberg, R.D.

1988-01-01

Recently, Eisenhut and co-workers have described development of iodine-131 labeled diphosphonates for palliative treatment of bone metastases. The compound labeled was alpha-amino (4-hydroxybenzylidene) diphosphonate (BDP3). Other beta-emitting radionuclides have been used for treatment of intractable pain secondary to bone metastases. These include strontium-89, which has some difficulties, particularly in terms of disposal of the excretions due to the long physical half-life of the life of the radionuclide. Yttrium-90 has also been used but has a relatively high hepatic uptake. Phosphorus-32 labeled compounds have also been used. Although palliation has been described, bone marrow depression has also occurred. Rhenium-186 also has been suggested, however, high renal uptake is a problem. At present, the iodine-131 labeled BDP3 appears to be the best of the available therapeutic radiopharmaceuticals. One of the major disadvantages in use of this compound is the production of gamma photons. While undesirable from a dosimetry viewpoint, gamma photons do, however, permit imaging if desired

Improved radioimmunotherapy of hematologic malignancies. [Final report

Energy Technology Data Exchange (ETDEWEB)

Press, O.W.

1992-03-24

This research project proposes to develop novel new approaches of improving the radioimmunodetection and radioimmunotherapy of malignancies by augmenting retention of radioimmunoconjugates by tumor cells. The approaches shown to be effective in these laboratory experiments will subsequently be incorporated into out ongoing clinical trials in patients. Specific project objectives include: to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclonal antibodies targeting tumor-associated antigens on human leukemia and lymphoma cells; To examine the effects of lysosomotropic amines (e.g. chloroquine, amantadine), carboxylic ionophores (monensin, nigericin), and thioamides (propylthiouracil), on the retention of radiolabeled MoAbs by tumor cells; to examine the impact of newer radioiodination techniques (tyramine cellobiose, paraiodobenzoyl) on the metabolic degradation of radioiodinated antibodies; to compare the endocytosis, intracellular routing, and degradation of radioimmunoconjugates prepared with different radionuclides ({sup 131}Iodine, {sup 111}Indium, {sup 90}Yttrium, {sup 99m}Technetium, {sup 186}Rhenium); and to examine the utility of radioimmunoconjugates targeting oncogene products for the radioimmunotherapy and radioimmunoscintigraphy of cancer.

Improved radioimmunotherapy of hematologic malignancies

Energy Technology Data Exchange (ETDEWEB)

Press, O.W.

1992-03-24

This research project proposes to develop novel new approaches of improving the radioimmunodetection and radioimmunotherapy of malignancies by augmenting retention of radioimmunoconjugates by tumor cells. The approaches shown to be effective in these laboratory experiments will subsequently be incorporated into out ongoing clinical trials in patients. Specific project objectives include: to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclonal antibodies targeting tumor-associated antigens on human leukemia and lymphoma cells; To examine the effects of lysosomotropic amines (e.g. chloroquine, amantadine), carboxylic ionophores (monensin, nigericin), and thioamides (propylthiouracil), on the retention of radiolabeled MoAbs by tumor cells; to examine the impact of newer radioiodination techniques (tyramine cellobiose, paraiodobenzoyl) on the metabolic degradation of radioiodinated antibodies; to compare the endocytosis, intracellular routing, and degradation of radioimmunoconjugates prepared with different radionuclides ({sup 131}Iodine, {sup 111}Indium, {sup 90}Yttrium, {sup 99m}Technetium, {sup 186}Rhenium); and to examine the utility of radioimmunoconjugates targeting oncogene products for the radioimmunotherapy and radioimmunoscintigraphy of cancer.

Spatial heterogeneity of tungsten transmutation in a fusion device

Science.gov (United States)

Gilbert, M. R.; Sublet, J.-Ch.; Dudarev, S. L.

2017-04-01

Accurately quantifying the transmutation rate of tungsten (W) under neutron irradiation is a necessary requirement in the assessment of its performance as an armour material in a fusion power plant. The usual approach of calculating average responses, assuming large, homogenised material volumes, is insufficient to capture the full complexity of the transmutation picture in the context of a realistic fusion power plant design, particularly for rhenium (Re) production from W. Combined neutron transport and inventory simulations for representative spatially heterogeneous high-resolution models of a fusion power plant show that the production rate of Re is strongly influenced by the surrounding local spatial environment. Localised variation in neutron moderation (slowing down) due to structural steel and coolant, particularly water, can dramatically increase Re production because of the huge cross sections of giant resolved resonances in the neutron-capture reaction of 186W at low neutron energies. Calculations using cross section data corrected for temperature (Doppler) effects suggest that temperature may have a relatively lesser influence on transmutation rates.

Crystal structures of a manganese(I and a rhenium(I complex of a bipyridine ligand with a non-coordinating benzoic acid moiety

Directory of Open Access Journals (Sweden)

Sheri Lense

2018-05-01

Full Text Available The structures of two facially coordinated Group VII metal complexes are reported, namely: fac-bromido[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylmanganese(I tetrahydrofuran monosolvate, [MnBr(C17H12N2O2(CO3]·C4H8O, I, and fac-[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylchloridorhenium(I tetrahydrofuran monosolvate, [ReCl(C17H12N2O2(CO3]·C4H8O, II. In both complexes, the metal ion is coordinated by three carbonyl ligands, a halide ion, and a 2-(2,2′-bipyridin-6-ylbenzoic acid ligand, in a distorted octahedral geometry. In manganese complex I, the tetrahydrofuran (THF solvent molecule could not be refined due to disorder. The benzoic acid fragment is also disordered over two positions, such that the carboxylic acid group is either positioned near to the bromide ligand or to the axial carbonyl ligand. In the crystal of I, the complex molecules are linked by a pair of C—H...Br hydrogen bonds, forming inversion dimers that stack up the a-axis direction. In the rhenium complex II, there is hydrogen bonding between the benzoic acid moiety and a disordered co-crystallized THF molecule. In the crystal, the molecules are linked by C—H...Cl hydrogen bonds, forming layers parallel to (100 separated by layers of THF solvent molecules.

Therapeutic efficacy and dosimetric aspects of Rhenium-188-HEDP in bone pain palliation

International Nuclear Information System (INIS)

Liepe, Knut

2005-01-01

Full text: Bone metastases are a frequent complication of cancer, occurring in up 70% of patients suffering from advanced breast or prostate cancer and often present with severe bone pain. In this purpose the radionuclide therapy is a useful option for cancer patients. Different radionuclides are described, such as 89 Sr, 32 P, 153 Sm-EDTMP, 186 Re-HEDP, 131 I-BDP3, 90 Y, 117mSn-DTPA, 188 Re-HEDP and 188 Re-DMSA. The most experiences are available for 89 Sr. An indication for the treatment are patients with osteoblastic metastases, bone pain, sufficient bone marrow function and at least of three bone metastases visualized in bone scan. A bisphosphonate therapy, a chemotherapy with lower bone marrow toxicity or a local field external beam radiotherapy represent no contraindications, especially because the reported synergistic effects to the systemic radionuclide therapy. In 33 treated patients (breast and prostate cancer) we investigated the effect of 188 Re-HEDP on pain relief, analgesic intake and impairment of bone marrow function. There were an improvement on the Karnofsky performance scale from 74 7% to 85 9% 12 weeks after therapy (p= 0.001). The pain score showed a maximum decrease from 44 ± 18% to 27 ± 20% in the 3rd to the 8th week after therapy (p = .009) and 76% had a pain relief (20% were pain free). The maximal differences between the values of platelets and leukocytes before and after therapy were not statistically significant (p = 0.021 and p = 0.094). In 105 investigated patients treated with different radionuclides ( 89 Sr, 153 Sm-EDTMP, 186 Re-HEDP, 188 Re-HEDP and 89 Sr in combination with chemotherapy) no different therapeutic efficacy of the treatments were observed. In dose calculation of 188 Re-HEDP a radiation dose of 3.83 ± 2.01 mGy/MBq (12.6 Gy for 3300 MBq) for bone metastases and 0.61 ± 0.21 mGy/MBq (2 Gy for 3300 MBq) were found. With the introducing of radionuclide treatments with chemotherapy and repeated treatments, the

Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor

Science.gov (United States)

Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy

2013-01-01

Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited

Absorbed dose distributions in patients with bone metastases from hormone refractory prostate cancer treated with Re-186 HEDP

International Nuclear Information System (INIS)

Denis Bacelar, A.M.; Dearnaley, D.P.; Divoli, A.; Chittenden, S.; Du, Y.; Flux, G.D.; O'Sullivan, J.M.

2015-01-01

Full text of publication follows. Aim: intravenous administration of Re-186 hydroxyethylidene-diphosphonate (HEDP) is used for metastatic bone pain palliation in hormone refractory prostate cancer patients. Dosimetry for bone seeking radionuclides is challenging due to the complex structure with osteoblastic, osteolytic and mixed lesions. The aim of this study was to perform image-based patient-specific 3D convolution dosimetry to obtain a distribution of the absorbed doses to each lesion and estimate inter- and intra-patient variations. Materials and methods: 28 patients received a fixed 5 GBq activity of Re-186 HEDP followed by peripheral blood stem cell rescue at 14 days in a phase II trial. A FORTE dual-headed gamma camera was used to acquire sequential Single-Photon-Emission Computed Tomography (SPECT) data of the thorax and pelvis area at 1, 4, 24, 48 and 72 hours following administration. The projection data were reconstructed using filtered-back projection and were corrected for attenuation and scatter. Voxelised cumulated activity distributions were obtained with two different methods. First, the scans were co-registered and the time-activity curves were obtained on a voxel-by-voxel basis. Second, the clearance curve was obtained from the mean number of counts in each individual lesion and used to scale the uptake distribution taken at 24 hours. The calibration factors required for image quantification were obtained from a phantom experiment. An in-house developed EGSnrc Monte Carlo code was used for the calculation of dose voxel kernels for soft-tissue and cortical/trabecular bone used to perform convolution dosimetry. Cumulative dose-volume histograms were produced and mean absorbed doses calculated for each spinal and pelvic lesion. Results: preliminary results show that the lesion mean absorbed doses ranged from 25 to 55 Gy when the medium was soft tissue and decreased by 40% if bone was considered. The use of the cumulated activity distribution

Analysis of femtogram-sized plutonium samples by thermal ionization mass spectrometry

International Nuclear Information System (INIS)

Smith, D.H.; Duckworth, D.C.; Bostick, D.T.; Coleman, R.M.; McPherson, R.L.; McKown, H.S.

1994-01-01

The goal of this investigation was to extend the ability to perform isotopic analysis of plutonium to samples as small as possible. Plutonium ionizes thermally with quite good efficiency (first ionization potential 5.7 eV). Sub-nanogram sized samples can be analyzed on a near-routine basis given the necessary instrumentation. Efforts in this laboratory have been directed at rhenium-carbon systems; solutions of carbon in rhenium provide surfaces with work functions higher than pure rhenium (5.8 vs. ∼ 5.4 eV). Using a single resin bead as a sample loading medium both concentrates the sample nearly to a point and, due to its interaction with rhenium, produces the desired composite surface. Earlier work in this area showed that a layer of rhenium powder slurried in solution containing carbon substantially enhanced precision of isotopic measurements for uranium. Isotopic fractionation was virtually eliminated, and ionization efficiencies 2-5 times better than previously measured were attained for both Pu and U (1.7 and 0.5%, respectively). The other side of this coin should be the ability to analyze smaller samples, which is the subject of this report

Research program to investigate the fundamental chemistry of technetium

Energy Technology Data Exchange (ETDEWEB)

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

2007-10-12

The objective of this research is to increase the knowledge of the fundamental technetium chemistry necessary to address challenges to the safe, long-term disposal of high-level nuclear waste posed by this element. The primary issues examined during the course of this project were the behavior of technetium and its surrogate rhenium during waste vitrification and glass corrosion. Since the redox behavior of technetium can play a large role in determining its volatility, one goal of this research was to better understand the behavior of technetium in glass as a function of the redox potential of the glass melt. In addition, the behavior of rhenium was examined, since rhenium is commonly used as a surrogate for technetium in waste vitrification studies. A number of glasses similar to Hanford Low Activity Waste (LAW) glasses were prepared under controlled atmospheres. The redox state of the glass was determined from the Fe(II)/Fe(III) ratio in the cooled glass, and the speciation of technetium and rhenium was determined by x-ray absorption fine structure (XAFS) spectroscopy. The behavior of rhenium and technetium during glass alteration was also examined using the vapor hydration test (VHT).

Synthesis and characterization of organohydrazino complexes of technetium, rhenium, and molybdenum with the [M(η1-HxNNR)(η2-HyNNR)] core and their relationship to radiolabeled organohydrazine-derivatives chemotactic peptides with diagnostic applications

International Nuclear Information System (INIS)

Rose, D.J.; Maresca, K.P.; Nicholson, T.

1998-01-01

In this paper, the authors present the details of the preparation of the imaging agent and its imaging properties. In order to define some structural possibilities for the coordination chemistry relevant to these reagents, they also present the results of investigations of the syntheses and structures of Tc, Mo, and Re complexes with hydrazinopyridine, which not only establish the formation of the robust unit, but also implicate chelate formation through the pyridine nitrogen as a significant structural determinant. The structures of the parent (bis)hydrazino-trichlorometalate core compounds are presented, allowing analysis of structural changes that occur when (2) protonation sites on the ligand change, (2) a different metal is employed, and (3) a different chelating hydrazine is utilized. The structures of the thiolate substitution products of these parent compounds are also presented. These derivatives demonstrate that rhenium and technetium have analogous substitution chemistry

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

Science.gov (United States)

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

2016-12-01

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. Copyright © 2016 Elsevier Inc. All rights reserved.

The chemistry on a subnanometer scale of radiation-induced precipitation and segregation in fast-neutron irradiated tungsten-rhenium alloys

International Nuclear Information System (INIS)

Hershitz, R.; Seidman, D.N.

1984-01-01

The phenomena of radiation-induced precipitation and segregation have been investigated in W-10 at.% Re and W-25 at.% Re alloys, employing the atom-probe field-ion-microscope technique. The specimens had been irradiated to a fast-neutron fluence of approx.4x10 22 neutrons cm -2 (e>0.1 MeV) at 575, 625 and 675 deg C. This corresponds to 8.6 dpa and an average displacement rate, for the two year irradiation time of 1.4x10 -7 dpa s -1 . In the W-10 at.% Re alloy, coherent, semicoherent and possibly incoherent precipitates with the composition approx.WRe and a disc-shaped morphology -- one or two atomic planes thick -- were detected at a number density of approx.10 16 cm -3 , and a mean diameter of approx.57 A. In the W-25 at.% Re alloy the same precipitates with the composition approx.WRe 3 were detected at a number density of approx.10 17 cm -3 and a mean diameter of 40 A. The semicoherent WRe 3 precipitates were associated with 4 He atoms; that is, they may have been heterogeneously nucleated. None of the other precipitates were associated with either line or planar defects or with any impurity atoms. Therefore, a true homogeneous radiation-induced precipitation occurs in these alloys. In the W-25 at.% Re alloy a two dimensional WRe 3 phase has been observed at a grain boundary. The nucleation of both precipitates in the vicinity of displacement cascades might be produced by primary knock-on atoms. In both cases, the first step in the nucleation is due to the formation of tightly-bound mobile mixed dumbbells which react to form an immobile di-rhenium cluster. Point-defect mechanisms for all the other observations are also discussed

Isolation and activity determination of 99Tc in nuclear waste by liquid scintillation counting

International Nuclear Information System (INIS)

Reis Junior, Aluisio S.; Temba, Eliane S.C.; Kastner, Geraldo F.; Monteiro, Roberto P.G.

2011-01-01

A radiochemical separation and purification for technetium was proposed for radioactive waste in which rhenium is to be used as a yield monitor. The separation was performed by anion exchange chromatography and the purification was performed by extraction chromatography using a TEVA resin.The determination of 99 Tc was by liquid scintillation counting and rhenium was activated by Triga Mark 1 research reactor and measured by gamma spectrometry. Some real samples of nuclear waste such as evaporator concentrate and filter were analysed. The chemical recovery determined using rhenium as tracer was around 90 %. (author)

Monte Carlo and analytical calculations of dose distributions in craniopharyngioma cysts treated with radiocolloids containing {sup 32}P or {sup 186}Re

Energy Technology Data Exchange (ETDEWEB)

Sadeghi, Mahdi [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, P.O. Box 31485/498, Karaj (Iran, Islamic Republic of)], E-mail: msadeghi@nrcam.org; Karimi, Elham; Sardari, Darush [Faculty of Engineering, Research and Science Campus, Islamic Azad University, Tehran (Iran, Islamic Republic of)

2009-09-15

In radiation treatments of some types of brain tumors, such as craniopharyngiomas, selection of an appropriate radionuclide is critical. The aim of this work was to calculate distributions of dose rates from {sup 32}P and {sup 186}Re in radiocolloids injected into craniopharyngioma cysts. The calculations were performed with the MCNP4C radiation transport code. Analytical calculations based on the Loevinger formula were also performed for {sup 32}P with the MATLAB software. The results of the two techniques for identical models were compared. The effects of the cyst wall type and of the density of the cyst inner fluid were investigated. The {sup 32}P activities required for providing 200, 250, and 300 Gy to cysts of different sizes were calculated.

Structure of Os - Pt nuclei and g factors of 186-192Os isotopes at low spins

International Nuclear Information System (INIS)

Ansari, A.

1987-10-01

Employing a pairing + quadrupole model interaction, especially suitable for the Os - Pt region, the ground state structure of these nuclei is investigated following a selfconsistent Hartree-Fock-Bogolyubov (HFB) approach. Effects of the inclusion of hexadecapole degrees of freedom in the Hamiltonian are also studied. All the osmium isotopes considered here come out to be prolate in shape in the ground state. 186 Pt is triaxial with γ=12 deg. and with the increasing mass number they gradually go over to the oblate shape at A=190 itself. In view of recent experimental data on g factors of osmium isotopes which show interesting variations as a function of mass number as well as spin, we have calculated these following the methods of variation after exact angular momentum projection of axial HFB wave functions and the cranked HFB theory. The observed trend of the variation of g factor at I=2 with the mass number is reproduced with very minor adjustments of the force constants of the Hamiltonian in both the approaches. However, the variation of g factor with spin, which is sensitive to the interplay between collective and the single particle degrees of freedom, can be understood only in the cranking approach. (author). 52 refs, 8 figs, 6 tabs

Adsorption and Diffusion of Lithium and Sodium on Defective Rhenium Disulfide: A First Principles Study.

Science.gov (United States)

Mukherjee, Sankha; Banwait, Avinav; Grixti, Sean; Koratkar, Nikhil; Singh, Chandra Veer

2018-02-14

Single-layer rhenium disulfide (ReS 2 ) is a unique material with distinctive, anisotropic electronic, mechanical, and optical properties and has the potential to be used as an anode in alkali-metal-ion batteries. In this work, first principles calculations were performed to systematically evaluate the potential of monolayer pristine and defective ReS 2 as anodes in lithium (Li)- and sodium (Na)-ion batteries. Our calculations suggest that there are several potential adsorption sites for Li and Na on pristine ReS 2 , owing to its low-symmetry structure. Additionally, the adsorption of Li and Na over pristine ReS 2 is very strong with adsorption energies of -2.28 and -1.71 eV, respectively. Interestingly, the presence of point defects causes significantly stronger binding of the alkali-metal atoms with adsorption energies in the range -2.98 to -3.17 eV for Li and -2.66 to -2.92 eV for Na. Re single vacancy was found to be the strongest binding defect for Li adsorption, whereas S single vacancy was found to be the strongest for Na. The diffusion of these two alkali atoms over pristine ReS 2 is anisotropic, with an energy barrier of 0.33 eV for Li and 0.16 eV for Na. The energy barriers associated with escaping a double vacancy and single vacancy for Li atoms are significantly large at 0.60 eV for the double-vacancy case and 0.51 eV for the single-vacancy case. Similarly, for Na, they are 0.59 and 0.47 eV, respectively, which indicates slower migration and sluggish charging/discharging. However, the diffusion energy barrier over a Re single vacancy is found to be merely 0.42 eV for a Li atom and 0.28 eV for Na. Overall, S single and double vacancies can reduce the diffusion rate by 10 3 -10 5 times for Li and Na ions, respectively. These results suggest that monolayer ReS 2 with a Re single vacancy adsorbs Li and Na stronger than pristine ReS 2 , with negligible negotiation with the charging/discharging rate of the battery, and therefore they can be used as an anode

Studying Angular Distribution of Neutron for (p,n) Reaction from 0.5 GeV to 1.5 GeV on some Heavy Targets 238U, 206Pb, 197Au, 186W

International Nuclear Information System (INIS)

Nguyen Mong Giao; Tran Thanh Dung; Nguyen Thi Ai Thu; Huynh Thi Xuan Tham

2010-08-01

The angular distributions of neutron are calculated for a spallation reaction induced by proton energy from 0.5 GeV to 1.5 GeV on target nuclei 206 Pb, 197 Au, 238 U, 186 W. In this report, we use nuclear data of JENDL-HE with evaluated proton induced cross-sections up to 3 GeV. The obtained results have been discussed in detail. (author)

Catalyst for disproportionation/double-bond isomerization of olefins

International Nuclear Information System (INIS)

Hughes, W.; Reusser, R.

1980-01-01

An activated calcined homogenous catalyst composition consists essentially of a support uranium and at least one of tungsten and rhenium, wherein said composition contains about 0.1 to 25 weight percent total uranium, tungsten, and rhenium, each calculated as the metal; and a weight ratio of uranium:at least one of tungsten and rhenium of about 2:1 to 1:1. The activated catalyst composition is prepared by steps which comprise forming a homogenous composite, calcining said homogenous composite in a molecular oxygen-containing atmosphere at elevated temperatures, and subsequently activating said calcined homogenous composite under reducing conditions at elevated temperatures. The catalyst composition according to claim 1 is one in which the total of uranium, tungsten, and rhenium is about 1 to 15 weight percent. The catalyst composition according to claim 2 is one in which the ratio of uranium to at least one of tungsten and rhenium is about 2:1 to 0.5:1. The catalyst composition according to claim 3 is one in which the support is alumina, silica, silica-alumina, zirconia, titania, thoria, aluminum phosphate, magnisium silicate, zinc aluminate, or mixture. The catalyst composition according to claim 4is one in which support is silica

Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

Science.gov (United States)

de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

2010-09-01

Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Rhenium(V) oxo complexes relevant to technetium renal imaging agents derived from mercaptoacetylglycylglycylaminobenzoic acid isomers. Structural and molecular mechanics studies

International Nuclear Information System (INIS)

Hansen, L.; Taylor, A. Jr; Marzilli, L.G.; Cini, R.

1992-01-01

The synthesis and characterization of three rhenium(V) oxo complexes derived from isomers of mercaptoacetylglycylglycylaminobenzoic acid (MAG 2 -ABAH 5 ) are reported. The isomers were synthesized from o-, m- and p-aminobenzoic acid and differed in the position of the terminal carboxyl group. The anions of 8-10, [ReO(MAG 2 -*ABAH)] - (* = para (8), meta (9), ortho (10)), contained the tetraanionic form of the ligands with the carboxyl group protonated. Compounds 8,9, and 10 were synthesized by exchange reactions of ReOCl 3 (Me 2 SO)(Ph 3 P) under moderate conditions and were isolated as [Ph 4 P] + , [Bu 4 N] + , and [Ph 4 P] + salts, respectively. The structures of 8 and 10 were determined by X-ray diffraction methods; except for the location of the carboxyl group, the structures are similar. The coordination geometry is pseudo square pyramidal, with nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The orientation of the carboxyl group in 10 is anti to the Re double-bond O group. Since the carboxyl groups are protonated in 8 and 10 and in other relevant structures from this class of radiopharmaceuticals including [Ph 4 As][TcO(MAG 3 H)] (MAG 3 H = tetraanionic form of mercaptoacetyltriglycine), the authors developed molecular mechanics parameters that allowed them to calculate the structures of 8, 10, and [TcO(MAG 3 H)] - . They then extended the calculations to all three isomeric complexes in their deprotonated forms and to [TcO(MAG 3 )] 2- in order to approximate their solution phase structures. They conclude that the [TcO(MAG 3 )] 2- species is conformationally flexible, and they have made an initial assessment of structures vs renal clearance

Magnetic interactions in rhenium-containing rare earth double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths)

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, Atsuhide; Doi, Yoshihiro; Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.jp

2017-04-15

The perovskite-type compounds containing both rare earth and rhenium Sr{sub 2}LnReO{sub 6} (Ln=Y, Tb-Lu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Re{sup 5+} ions are structurally ordered at the B site of the perovskite SrBO{sub 3}. Magnetic anomalies are found in their magnetic susceptibility and specific heat measurements at 2.6–20 K for Ln=Y, Tb, Dy, Yb, Lu compounds. They are due to magnetic interactions between Re{sup 5+} ions. The results of the magnetic hysteresis and remnant magnetization measurements for Sr{sub 2}YReO{sub 6} and Sr{sub 2}LuReO{sub 6} indicate that the antiferromagnetic interactions between Re{sup 5+} ions below transition temperatures have a weak ferromagnetic component. The analysis of the magnetic specific heat data for Sr{sub 2}YbReO{sub 6} shows that both the Yb{sup 3+} and Re{sup 5+} ions magnetically order at 20 K. For the case of Sr{sub 2}DyReO{sub 6}, magnetic ordering of the Re{sup 5+} moments occurs at 93 K, and with decreasing temperature, the moments of Dy{sup 3+} ferromagnetically order at 5 K from the measurements of magnetic susceptibility and specific heat. - Graphical abstract: Crystal structure of double perovskite Sr{sub 2}LnReO{sub 6}. Red and black lines show cubic and monoclinic unit cells, respectively. - Highlights: • Double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths) were prepared. • They show an antiferromagnetic transition at 2.6–20 K. • In Sr{sub 2}DyReO{sub 6}, Dy and Re moments magnetically order at 5 and 93 K, respectively.

188Re(V) Nitrido Radiopharmaceuticals for Radionuclide Therapy.

Science.gov (United States)

Boschi, Alessandra; Martini, Petra; Uccelli, Licia

2017-01-19

The favorable nuclear properties of rhenium-188 for therapeutic application are described, together with new methods for the preparation of high yield and stable 188 Re radiopharmaceuticals characterized by the presence of the nitride rhenium core in their final chemical structure. 188 Re is readily available from an 188 W/ 188 Re generator system and a parallelism between the general synthetic procedures applied for the preparation of nitride technetium-99m and rhenium-188 theranostics radiopharmaceuticals is reported. Although some differences between the chemical characteristics of the two metallic nitrido fragments are highlighted, it is apparent that the same general procedures developed for the labelling of biologically active molecules with technetium-99m can be applied to rhenium-188 with minor modification. The availability of these chemical strategies, that allow the obtainment, in very high yield and in physiological condition, of 188 Re radiopharmaceuticals, gives a new attractive prospective to employ this radionuclide for therapeutic applications.

188Re(V) Nitrido Radiopharmaceuticals for Radionuclide Therapy

Science.gov (United States)

Boschi, Alessandra; Martini, Petra; Uccelli, Licia

2017-01-01

The favorable nuclear properties of rhenium-188 for therapeutic application are described, together with new methods for the preparation of high yield and stable 188Re radiopharmaceuticals characterized by the presence of the nitride rhenium core in their final chemical structure. 188Re is readily available from an 188W/188Re generator system and a parallelism between the general synthetic procedures applied for the preparation of nitride technetium-99m and rhenium-188 theranostics radiopharmaceuticals is reported. Although some differences between the chemical characteristics of the two metallic nitrido fragments are highlighted, it is apparent that the same general procedures developed for the labelling of biologically active molecules with technetium-99m can be applied to rhenium-188 with minor modification. The availability of these chemical strategies, that allow the obtainment, in very high yield and in physiological condition, of 188Re radiopharmaceuticals, gives a new attractive prospective to employ this radionuclide for therapeutic applications. PMID:28106830

The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

Energy Technology Data Exchange (ETDEWEB)

Harca, I. M. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna, Russia and Faculty of Physics, University of Bucharest - P.O. Box MG 11, RO 77125, Bucharest-Magurele (Romania); Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna (Russian Federation); Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D. [IPN, CNRS/IN2P3, Univ. Paris-Sud, 91405 Orsay (France); Chubarian, G. [Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); Hanappe, F. [Universite Libre de Bruxelles (ULB), Bruxelles (Belgium); Piot, J.; Schmitt, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Trzaska, W. H. [Accelerator Laboratory of University of Jyväskylä (JYFL), Jyväskylä (Finland); Vardaci, E. [Dipartamento di Scienze Fisiche and INFN (INFN-Na), Napoli (Italy)

2015-02-24

The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

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

Energy Technology Data Exchange (ETDEWEB)

Clavaud, C

2006-02-15

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.)

RULINGS OF THE NATIONAL COURTS FOLLOWING THE CURIA DECISION IN CASE C-186/16, ANDRICIUC AND OTHERS VS BANCA ROMANEASCA

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Monica CALU

2018-05-01

Full Text Available The CJEU's judgment in Andriciuc and Others vs Banca Românească Case C-186/16 that came in September 2017 is an addition to a growing body of case law on procedural obstacles to consumer protection under Directive 93/13/EEC. According to the Court, a contractual term must be drafted in plain intelligible language, the information obligations should be performed by the bank in a manner to make the well-informed and reasonably observant and circumspect consumer aware of both possibility of a rise or fall in the value of the foreign currency and also enabling estimation of the significant economic consequences of repayment of the loan in the same currency as the currency in which the loan was taken out. Following a succession of consumer-friendly preliminary rulings from European Court of Justice (Case C-26/13, Árpád Kásler, Hajnalka Káslerné Rábai v OTP Jelzálogbank Zrt and Case C-186/16 Andriciuc and Others v Banca Românească, bank customers across the European Union are increasingly taking their banks to court. However, there are still a lot provisions in the national legislations which made the judicial review of unfair contract terms difficult and reveals the limits of consumer protection under Directive 93/13. Also, we focus on the powers of the national court when dealing with a term considered to be unfair (civil courts and the availability of legal remedies in ensuring the effectiveness of the Directive. Although the CJEU provides interpretation of EU law, the national court alone has jurisdiction to find and assess the facts in the case before it and to interpret and apply national law. The ruling issued by the Court of Justice of the European Union (CJUE in the Andriciuc versus Banca Românească case represents a great advantage for some of the European debtors. In this paper, we intend to examine, starting from the theory of abusive clauses and referring to the jurisprudence of the European Court of Justice in the matter, to

Neutron capture cross section measurements of 109Ag, 186W and 158Gd on filtered neutron beams of 55 and 144 keV

International Nuclear Information System (INIS)

Vuong Huu Tan; Nguyen Canh Hai; Pham Ngoc Son; Tran Tuan Anh

2004-12-01

The neutron capture cross sections of the 109 Ag(n, γ) 110 mAg, 186 W(n, γ) 187 W and 158 Gd(n, γ) 159 Gd have been measured at 55 and 144 keV by the activation method with filtered neutron beams of the Dalat nuclear research reactor. The cross sections were determined relative to the standard capture cross sections of 197 Au using highly purity metallic foils of Ag, W, Gd and Au. The high efficient HPGe detector was used for the gamma rays measurement from the samples, and absolute efficiency calibration was performed by using a set of standard radioisotope sources and a multi-nuclides standard solution. The present results were compared with the previous measurements listed in EXFOR-CINDA, and the evaluated data of ENDF/B-VI. (author)

Comparison Of The MWCNTs-Rh And MWCNTs-Re Carbon-Metal Nanocomposites Obtained In High-Temperature

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Dobrzańska-Danikiewicz A.D.

2015-09-01

Full Text Available Carbon-metal nanocomposites consisting of multiwalled carbon nanotubes coated with rhodium or rhenium nanoparticles by the high-temperature method were fabricated during the research undertaken. Multiwalled carbon nanotubes fabricated by Catalytic-Chemical Vapour Deposition (CCVD were used in the investigations. Multiwalled carbon nanotubes functionalisation in acid or in a mixture of acids was applied to deposit rhodium or rhenium nanoparticles onto the surface of carbon nanotubes, and then the material was placed in a solution being a precursor of metallic nanoparticles. The material prepared was next subjected to high-temperature reduction in the atmosphere of argon and/or hydrogen to deposit rhodium or rhenium nanoparticles onto the surface of multiwalled carbon nanotubes. The investigations performed include, respectively: fabrication of a CNT-NPs (Carbon NanoTube-NanoParticles nanocomposite material; the characterisation of the material produced including examination of the structure and morphology, and the assessment of rhodium and/or rhenium nanoparticles distribution on the surface of carbon nanotubes. Micro- and spectroscopy techniques were employed to characterise the structure of the nanocomposites obtained.

A model for the oceanic mass balance of rhenium and implications for the extent of Proterozoic ocean anoxia

Science.gov (United States)

Sheen, Alex I.; Kendall, Brian; Reinhard, Christopher T.; Creaser, Robert A.; Lyons, Timothy W.; Bekker, Andrey; Poulton, Simon W.; Anbar, Ariel D.

2018-04-01

Emerging geochemical evidence suggests that the atmosphere-ocean system underwent a significant decrease in O2 content following the Great Oxidation Event (GOE), leading to a mid-Proterozoic ocean (ca. 2.0-0.8 Ga) with oxygenated surface waters and predominantly anoxic deep waters. The extent of mid-Proterozoic seafloor anoxia has been recently estimated using mass-balance models based on molybdenum (Mo), uranium (U), and chromium (Cr) enrichments in organic-rich mudrocks (ORM). Here, we use a temporal compilation of concentrations for the redox-sensitive trace metal rhenium (Re) in ORM to provide an independent constraint on the global extent of mid-Proterozoic ocean anoxia and as a tool for more generally exploring how the marine geochemical cycle of Re has changed through time. The compilation reveals that mid-Proterozoic ORM are dominated by low Re concentrations that overall are only mildly higher than those of Archean ORM and significantly lower than many ORM deposited during the ca. 2.22-2.06 Ga Lomagundi Event and during the Phanerozoic Eon. These temporal trends are consistent with a decrease in the oceanic Re inventory in response to an expansion of anoxia after an interval of increased oxygenation during the Lomagundi Event. Mass-balance modeling of the marine Re geochemical cycle indicates that the mid-Proterozoic ORM with low Re enrichments are consistent with extensive seafloor anoxia. Beyond this agreement, these new data bring added value because Re, like the other metals, responds generally to low-oxygen conditions but has its own distinct sensitivity to the varying environmental controls. Thus, we can broaden our capacity to infer nuanced spatiotemporal patterns in ancient redox landscapes. For example, despite the still small number of data, some mid-Proterozoic ORM units have higher Re enrichments that may reflect a larger oceanic Re inventory during transient episodes of ocean oxygenation. An improved understanding of the modern oceanic Re

Radiological assessment and remedial action report for the ''Son of Lansdowne'' property, 186 North Lansdowne Avenue, Lansdowne, Pennsylvania

International Nuclear Information System (INIS)

Smith, W.H.; Wynveen, R.A.

1987-08-01

This document reports the results of a radiological assessment and remedial action program conducted by Argonne National Laboratory personnel at a radioactively contaminated private residence in Lansdowne, Pennsylvania. The program was conducted on the residence at 186 Lansdowne Avenue. The survey conducted by the ANL personnel indicated that several dozen areas or spots of contamination were present on all floors and the basement of the three-story house. Contamination was found on furniture, carpeting, walls, floors, woodwork, and ceilings. Remedial action undertaken to remove the contamination ranged from scrubbing, to scraping, to shaving of wood, to removal and disposal of items and material that could not be adequately decontaminated. Outdoors, contaminated soil was removed from the backyard, and the driveway was dug up so the contaminated subsurface material could be removed. The remedial action generated quantities of radioactive waste, including four 55-gallon drums and one M-III bin (120 ft 3 ) containing floor tile, concrete, personal items, furniture, floor scrapings, vermiculite absorbed scrub water, and other items. In addition, there were 24 M-III bins containing approximately 112 tons of contaminated soil and rock from the two contaminated areas in the backyard and from the contaminated subsurface of the driveway. 2 refs., 39 figs., 12 tabs

Systematics of flux jumps and the stabilizing effect of flux creep in a La1.86Sr0.14CuO4 single crystal

International Nuclear Information System (INIS)

McHenry, M.E.; Lessure, H.S.; Maley, M.P.; Coulter, J.Y.; Tanaka, I.; Kojima, H.

1992-01-01

Flux jumps have been observed in a large (138 mg) single crystal of La 1.86 Sr 0.14 CuO 4 . Both complete and incomplete flux jumps are observed with the energy dissipated by complete flux jumps consistent with temperature rises to nearly Tc. The systematics of these flux jumps with respect to field history, temperature and the time duration of the hysteresis measurements are reported. The field at which flux jumps first occur and their subsequent spacing are not consistent with a simple adiabatic theory of flux jumps for our experimental conditions. Instead, the crystal is observed to be stabilized against flux jumps by flux creep which occurs during the time interval over which field steps are accomplished as well as during imposed time intervals between field steps. (orig.)

Improved creep strength of nickel-base superalloys by optimized γ/γ′ partitioning behavior of solid solution strengthening elements

International Nuclear Information System (INIS)

Pröbstle, M.; Neumeier, S.; Feldner, P.; Rettig, R.; Helmer, H.E.; Singer, R.F.; Göken, M.

2016-01-01

Solid solution strengthening of the γ matrix is one key factor for improving the creep strength of single crystal nickel-base superalloys at high temperatures. Therefore a strong partitioning of solid solution hardening elements to the matrix is beneficial for high temperature creep strength. Different Rhenium-free alloys which are derived from CMSX-4 are investigated. The alloys have been characterized regarding microstructure, phase compositions as well as creep strength. It is found that increasing the Titanium (Ti) as well as the Tungsten (W) content causes a stronger partitioning of the solid solution strengtheners, in particular W, to the γ phase. As a result the creep resistance is significantly improved. Based on these ideas, a Rhenium-free alloy with an optimized chemistry regarding the partitioning behavior of W is developed and validated in the present study. It shows comparable creep strength to the Rhenium containing second generation alloy CMSX-4 in the high temperature / low stress creep regime and is less prone to the formation of deleterious topologically close packed (TCP) phases. This more effective usage of solid solution strengtheners can enhance the creep properties of nickel-base superalloys while reducing the content of strategic elements like Rhenium.

The Efficacy of Magnetic Resonance Imaging and X-Ray in the Evaluation of Response to Radiosynovectomy in Patients with Hemophilic Arthropathy

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Tamer Özülker

2011-08-01

Full Text Available Objective: We aimed to assess the role of Magnetic Resonance Imaging (MRI and X-Ray in the evaluation of response to radiosynovectomy (RS in patients with hemophilic arthropathy. Material and Methods: Eleven patients who suffered from hemophilic arthropathy with a mean age of 11.7 (range between 7-15 were included in this study. 148-185 MBq Yttrium 90 silicate (Y-90 was administered intraarticularly to ten knee joints and one patient was treated with intraarticular 74 MBq Rhenium 186 (Re-186 injection into his ankle. Before radiosynovectomy, plain anteroposterior and lateral X-rays of the target joints were obtained by standard technique. The follow-up MRI and X-ray studies of the patients were done 6 months after RS. Pettersson hemophilic arthropathy scales were utilized to stage the condition of the joints on plain X-ray and classification of the investigated joints on MRI were done according to Denver score. The clinical assessment of the efficacy of the RS was made with the comparison of the average bleedings before and after the intervention. Results: During the 6-month follow-up period after RS, an improvement in number of hemarthrosis 75% or greater compared with the prior six months occurred in six joints (54.5%. The Pettersson scores worsened in 1/11 (9%, remained unchanged in 9/11 (81.8%, and improved in 1/11 (9% joints. At the 6-month follow-up, the MRI score worsened in one (9% and was unchanged in 10/11 joints (90.9%. Conclusion: MRI is a more sensitive tool than plain radiography for evaluating and follow-up of joint disease in persons with hemophilia, but both methods don’t show correlation with the therapeutic response. (MIRT 2011;20:38-44

Substitution reactions of technetium complexes

International Nuclear Information System (INIS)

Omori, T.

1997-01-01

Substitution reactions of a series of technetium complexes are considered in comparison with corresponding reactions of rhenium. Rhenium and technetium complexes are rather inert in substitution reactions, the latter are characterized by greater rate constants when they proceed according to dissociative mechanism. In rare cases when k Tc /k Re id little it is assumed that the reaction proceeds according to the associative mechanism. (author)

Mew organometallic complexes of technetium in different oxidation states

International Nuclear Information System (INIS)

Joachim, J.E.

1993-09-01

New organometallic compounds of Tc(I), Tc(III) and Tc(VII) were synthesized and their properties examined. These compounds were correlated with their homologous compounds of manganese and rhenium, which were also synthesized by the same route. The molecular and crystal structures of most technetium complexes and of the homologous complexes of manganese and rhenium were determined by single crystal X-ray diffraction. (orig.) [de

Emission property of scandia and Re doped tungsten matrix dispenser cathode

International Nuclear Information System (INIS)

Wang Jinshu; Wang Yanchun; Liu Wei; Li Lili; Wang Yiman; Zhou Meiling

2008-01-01

Scandia and rhenium doped tungsten powders have been prepared by solid-liquid doping combined with two-step reduction method. The experimental results show that scandia distributes evenly in the doped tungsten powder. Moreover, the addition of scandia and rhenium could decrease the particle size of tungsten. By using this kind of powder, scandia and rhenium doped tungsten matrix with sub-micrometer sized tungsten grains and a uniform distribution of Sc 2 O 3 together with high pore density has been obtained. The emission property result shows that high space charge limited current density of more than 30 A/cm 2 at 850 deg. C has been obtained for this cathode. This excellent emission capability results from an active layer uniformly covering the sub-micron structure framework of the cathodes

Circulating forms of immunoreactive parathyroid hormone-related protein for identifying patients with humoral hypercalcemia of malignancy. A comparative study with C-terminal (109-141)- and N-terminal (1-86)-region-specific PTHrP radioassay

International Nuclear Information System (INIS)

Suehiro, Mitsuko; Murakami, Minoru; Fukuchi, Minoru

1994-01-01

We evaluated the circulating forms of immunoreactive parathyroid hormone-related protein(PTHrP) in 115 healthy subjects and 122 patients with malignant diseases by using radioassay systems (RAS) specific for the C-terminal (109-141) fragment of PTHrP (C-RAS) and for the N-terminal(1-86) (N-RAS). PTHrP levels in healthy controls ranged from 1.5 to 38.2 (mean: 24.5) pmol/L with the C-RAS and from 0.9 to 2.5 (mean: 1.7) pmol/L with the N-RAS. The ratio of circulating N-terminal fragment (N) to C-terminal fragment (C) of PTHrP was calculated to be about 1 : 14.4 in the healthy subjects. Of the 122 patients with malignant diseases, 40 (32.8%) had circulating PTHrP levels undetectable with the N-RAS, but only 11 (9.0%) patients had levels undetectable with the C-RAS. Of the former 122 patients, 41 (33.6%) had high PTHrP as determined with the C-RAS, and 10 (8.2%) had high PTHrP as determined with the N-RAS. The former of these included only 8 (19.5%) humoral hypercalcemia malignancy(HHM) patients, while the latter included 8 (80.0%) HHM patients. The circulating N to C ratio was about 1 : 70.7 in the HHM patients. The N and C obtained with the different RASs showed a close correlation (r=0.86). The values also showed a close correlation with serum Ca; r=0.75 for C-RAS and r=0.81 for N-RAS. In addition, the correlation between the PTHrP reading obtained with the different RASs and serum Cr were: r=0.42 with C-RAS and r=0.26 with N-RAS. The circulating form of immunoreactive PTHrP fragments is therefore comprised mainly of PTHrP (109-141). In contrast, circulating concentrations of the PTHrP (1-86) fragment are very low, but detection of the PTHrP (1-86) fragment with the N-RAS is a more useful indicator of HHM with fewer false positive results and is less likely to be influenced by renal function than the detection of the PHPrP (109-141) fragment with C-RAS. (author)

Association between in-hospital mortality and renal dysfunction in 186,219 patients hospitalized for acute stroke in the Emilia-Romagna region of Italy.

Science.gov (United States)

Fabbian, Fabio; Gallerani, Massimo; Pala, Marco; De Giorgi, Alfredo; Salmi, Raffaella; Dentali, Francesco; Ageno, Walter; Manfredini, Roberto

2014-11-01

Using a regional Italian database, we evaluated the relationship between renal dysfunction and in-hospital mortality (IHM) in patients with acute stroke (ischemic/hemorrhagic). Patients were classified on the basis of renal damage: without renal dysfunction, with chronic kidney disease (CKD), and with end-stage renal disease (ESRD). Of a total of 186,219 patients with a first episode of stroke, 1626 (0.9%) had CKD and 819 (0.4%) had ESRD. Stroke-related IHM (total cases) was independently associated with CKD, ESRD, atrial fibrillation (AF), age, and Charlson comorbidity index (CCI). In patients with ischemic stroke (n=154,026), IHM remained independently associated with CKD, ESRD, AF, and CCI. In patients with hemorrhagic stroke (n=32,189), variables that were independently associated with IHM were CKD, ESRD, and AF. Renal dysfunction is associated with IHM related to stroke, both ischemic and hemorrhagic, with even higher odds ratios than those of other established risk factors, such as age, comorbidities, and AF. © The Author(s) 2013.

Iodine chemistry effect on source term assessments. A MELCOR 186 YT study of a PWR severe accident sequence

International Nuclear Information System (INIS)

Herranz, Luis E.; Garcia, Monica; Otero, Bernadette

2009-01-01

Level-2 Probabilistic Safety Analysis has demonstrated to be a powerful tool to give insights into multiple aspects concerning severe accidents: phenomena with the greatest potential to lead to containment failure, safety systems performance and, even, to identify any additional accident management that could mitigate the consequences of such an even, etc. A major result of level-2 PSA is iodine content in Source Term since it is the main responsible for the radiological impact during the first few days after a hypothetical severe accident. Iodine chemistry is known to considerably affect iodine behavior and although understanding has improved substantially since the early 90's, a thorough understanding is still missing and most PSA studies do not address it when assessing severe accident scenarios. This paper emphasizes the quantitative and qualitative significance of considering iodine chemistry in level-2 PSA estimates. To do so a cold leg break, low pressure severe accident sequence of an actual pressurized water reactor has been analyzed with the MELCOR 1.8.6 YT code. Two sets of calculations, with and without chemistry, have been carried out and compared. The study shows that iodine chemistry could result in an iodine release to environment about twice higher, most of which would consist of around 60% of iodine in gaseous form. From these results it is concluded that exploratory studies on the potential effect of iodine chemistry on source term estimates should be carried out. (author)

The specific features of Guillain–Barré syndrome in Russia: Analysis of 186 cases

Directory of Open Access Journals (Sweden)

N. A. Suponeva

2014-01-01

Full Text Available The medical records of 186 patients diagnosed with Guillain-Barré syndrome (GBS who had been followed up at the Research Center of Neurology, Russian Academy of Medical Sciences, in 2000 to 2011 were retrospectively analyzed. Most (65 % of the patients had severe GBS; 19 % of the patients were on mechanical ventilation (MV for an average of 21 (13; 48 days. The forms of GBS, such as acute inflammatory demyelinating polyneuropathy (AIDP (n = 141; 78 %, and axonal variants, such as acute motor axonal neuropathy (AMAN, acute sensorimotor axonal neuropathy (AMSAN, i. e. AMAN / AMSAN (n = 39; 22 %, were studied separately. There was a significant difference in the seasonal revalence (p < 0.05. AIDP was encountered evenly throughout the year; AMAN / AMSAN occurred in 46 % of cases in summer. AIDP was followed by acute respiratory viral infection in 35 % of cases; diarrhea wasby the axonal forms in 36 % (p < 0.05. The axonal forms ran a severer course than AIDP: MV was performed twice more frequently (33 and 15 %, respectively; its duration was 6‑fold longer: 90 (46; 102 and 15 (10; 21 days (p < 0.05. AMAN / AMSAN was characterized by a severer neurological status and disability in the acute period, as shown by the NIS, MRCss, INCAT, R-ODS, and Barthel scales; these patients showed a poorer response to pathogenetic therapy (p < 0.05: 59 % with an insufficient effect; 15 % of those with AIDP. After six years, the majority (84 % of the patients with AIDP walked alone and only 16 % were assisted. In the same period, less than half of the patients (40 % with AMAN / AMSAN walked alone and a third (29 % could move with assistance and almost the same percentage (31 % could not walk.Thus, a number of specific features of GBS were found in a Russian population (equal age and sex distribution; a larger percentage of the axonal forms than in European countries and the United States; however, the most characteristics did not differ from the global

175 - 186 Galadanchi

African Journals Online (AJOL)

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ABSTRACT. In this work, a 120 capacity automobile parking control system was designed and simulated. The .... LATCHES. A latch is a type of bistable logic device (memory unit) ..... The mode of operation is based on the working principle of ...

186 ORIGINAL ARTICLE

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Boaz

Background: Cocoa, Tea, and Coffee products are consumed worldwide; they are ... market and benchmark it with standard specifications, to determine the products safety for human consumption and ...... American Public Health Association.

ORIGINAL ARTICLE 186

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boaz

such as cell appearance, cell shape, size, pigmentation. [11-13]. ... able to detect bacterial species that were omitted by culture-based ..... Wound Repair and Regeneration,. 19: 532-541. 33. ... pneumoniaein a rabbit ear wound model. BMC.

186 - 189_Modibbo

African Journals Online (AJOL)

DR. AMINU

2013-06-01

Jun 1, 2013 ... Keywords: Hausa, Birth Weight, Hand Length, Hand Breadth, Foot Length, Foot Breadth. ... (Nigeria inclusive), where most newborns die at home ... and longitude 9.4º East with the Kano city as the capital of the State. The State at present is the most populous in Nigeria, with over 9,000,000 people.

Incidence and management of infusion reactions to infliximab in 186 italian patient’s with rheumatoid arthritis: the Padua experience

Directory of Open Access Journals (Sweden)

S. Todesco

2011-09-01

Full Text Available Objective: We report the incidence and treatment of infusion reactions to infliximab, a chimeric monoclonal IgG1 antibody against tumor necrosis factor a, in a large cohort of patients with rheumatoid arthritis. Patients and methods: One hundred eighty six patients with rheumatoid arthritis treated with infliximab for a total of 216.6 patient years were retrospectively evaluated. Patients received 2160 infliximab infusions at the Division of Rheumatology at the University Hospital of Padua from May, 2000 to April, 2004. Specific treatment protocols for initial and subsequent acute infusion reactions were followed and the outcomes documented. Results: The overall incidence of infusion reactions to infliximab was 0.8% (19 out of 2160 of infusions, affecting 10.2% of patients (19 out of 186. Mild, moderate, or severe acute reactions occurred in 0.1% (3 of 2160, 0.6% (13 of 2160, and 0.04% (1 of 2160 of infliximab infusions, respectively. Delayed infusion reactions occurred in 0.09% (2 of 2160 of infusions. Use of specific treatment protocols resulted in rapid resolution of all acute reactions to infliximab. With a prophylaxis protocol, all patients who experienced an initial mild acute reaction were able to receive additional infusions. Conclusions: Using appropriate treatment protocols, infliximab infusion reactions were effectively treated and prevented in patients with mild acute reactions upon retreatment. In the case of moderate to severe infusion reactions, the risks and the benefits of the continuation of infliximab therapy need to be carefully considered.

Processing of Refractory Metal Alloys for JOYO Irradiations

International Nuclear Information System (INIS)

RF Luther; ME Petrichek

2006-01-01

This is a summary of the refractory metal processing experienced by candidate Prometheus materiats as they were fabricated into specimens destined for testing within the JOYO test reactor, ex-reactor testing at Oak Ridge National Laboratory (ORNL), or testing within the NRPCT. The processing is described for each alloy from the point of inception to the point where processing was terminated due to the cancellation of Naval Reactor's involvement in the Prometheus Project. The alloys included three tantalum-base alloys (T-111, Ta-10W, and ASTAR-811C), a niobium-base alloy, (FS-85), and two molybdenum-rhenium alloys, one containing 44.5 w/o rhenium, and the other 47.5 w/o rhenium. Each of these alloys was either a primary candidate or back-up candidate for cladding and structural applications within the space reactor. Their production was intended to serve as a forerunner for large scale production ingots that were to be procured from commercial refractory metal vendors such as Wah Chang

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

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Awatef Ayadi

2015-08-01

Full Text Available The synthesis and full characterization of two tetrathiafulvalene-appended azine ligands, namely 2-([2,2’-bi(1,3-dithiolylidene]-4-yl-6-((2,4-dinitrophenylhydrazonomethylpyridine (L1 and 5-([2,2’-bi(1,3-dithiolylidene]-4-yl-2-((2,4-dinitrophenylhydrazonomethylpyridine (L2 are described. The crystal structure of ligand L1 indicates that the ligand is completely planar with the presence of a strong intramolecular N3–H3···O1 hydrogen bonding. Titration experiments with inorganic anions showed that both ligands are suitable candidates for the sensing of fluoride anions. Ligand L2 was reacted with a Re(I cation to yield the corresponding rhenium tricarbonyl complex 3. In the crystal structure of the newly prepared electroactive rhenium complex the TTF is neutral and the rhenium cation is hexacoordinated. The electrochemical behavior of the three compounds indicates that they are promising for the construction of crystalline radical cation salts.

Six-year clinical follow-up after treatment of diffuse in-stent restenosis with cutting balloon angioplasty followed by intracoronary brachytherapy with liquid rhenium-188-filled balloon via transradial approach

International Nuclear Information System (INIS)

Hang Chiling; Wu Chiungjen; Hsieh Bortsung

2010-01-01

Long-term follow-up studies revealed a significant decline in the benefits of intracoronary radiation for in-stent restenosis. A total of 25 study and 25 contemporaneous control patients with diffuse in-stent restenosis who underwent cutting balloon angioplasty (CBA) transradially, followed by subsequent intracoronary irradiation with a liquid β-emitter Rhenium-188 ( 188 Re)-filled balloon were enrolled in the study. The mean clinical follow-up durations were 64.9±13.0 and 66.3±13.8 months for the irradiated and control patients, respectively. Six-month angiographic restenosis was observed in 16% (4 of 25) of the patients in the irradiated group and 48% (12 of 25) of the patients in the control groups (P=0.03). The 6-month major adverse cardiac events (MACE) rate was 12% and 44%, respectively (P=0.025). The 3-year follow-up angiography was performed in 16 of 21 (76%) irradiated patients and in 4 of 13 (31%) control patients who had no significant restenosis at the 6-month angiographic follow-up. Restenosis occurred in 1 of 16 (7%) irradiated patients and 2 of 4 (50%) control patients. Late target lesion revascularization was performed in 1 irradiated and 2 control patients. The MACE rate within 6 years was significantly reduced in the irradiated group (20% vs. 56%, P=0.019). Brachytherapy using 188 Re-filled balloon following CBA for diffuse in-stent restenotic native coronary arteries is effective in reducing target lesion restenosis and improving long-term outcomes. (author)

SPECT/CT: can it be helpful in the evaluation of the distribution of the radionuclide in the joint following radio-synovectomy?

International Nuclear Information System (INIS)

Ozulker, F.; Kucukoz Uzun, A.; Ozulker, T.

2015-01-01

Full text of publication follows. Planar control scintigraphies have been used for the detection of any possible extra articular leakage after radio-synovectomy in patients with haemophilic arthropathy. In this study we aimed at assessing whether utilization of SPECT-CT for the same purpose can provide additional information. Patients who fulfilled the following prerequisites were included for radio synovectomy application: (1) more than four hemorrhagic episodes in six months, (2) at least a Stage II haemophilic arthropathy according to the classification of Arnold and Haltering, and (3) persistent synovitis. Six male patients (5 hemophilia A, 1 hemophilia B) who suffered from haemophilic arthropathy with a mean age of 10.5 (range between 8-15) were included in this study. We administered 148-185 MBq Yttrium 90 silicate (Y-90) to 5 knee joints, 74 MBq Rhenium 186 (Re-186) to 1 elbow joint and 74 MBq Re-186 to two ankle joints of these patients. The median number of bleedings into the target joints was 10.1 ± 1.4 in the six months prior to the procedure. All patients were admitted to the hospital and treated with factor replacement so as to raise the factor level of the patient to 80% the following morning and 50% for three days thereafter. The effusion in the joint was evacuated before the injection of the radiocolloid. Intra-articular injections in ankle and elbow joints were done under fluoroscopic guidance. The joint was moved rapidly a few times to distribute the radiocolloid, after which a plaster of paris cast was applied for 72 hours. One hour after the RS, planar images of the treated joints and the regional lymph nodes were obtained with gamma camera and SPECT-BT acquisitions were obtained from treated joints to confirm the appropriate distribution of the radionuclide in the joint. Distribution of the radionuclide in joint spaces was normal and we haven't encountered any extra articular leakage. In one patient there was loculation at activity in

Metal extraction by amides of carboxylic acids

International Nuclear Information System (INIS)

Skorovarov, D.I.; Chumakova, G.M.; Rusin, L.I.; Ul'anov, V.S.; Sviridova, R.A.; Sviridov, A.L.

1988-01-01

Extraction ability of various amides was studied. Data on extraction of rare earths, vanadium, molybdenum, rhenium, uranium, niobium, tantalum by N,N-dibutyl-amides of acetic, nonanic acids and fatly synthetic acids of C 7 -C 9 fractions are presented. Effect of salting-out agents, inorganic acid concentrations on extraction process was studied. Potential ability of using amides of carboxylic acids for extractional concentration of rare earths as well as for recovery and separation of iron, rhenium, vanadium, molybdenum, uranium, niobium, and tantalum was shown

Formation of a Six-Coordinate fac-[Re(Co)3]+ Complex by the N-C bond cleavage of a potentially tetradentate ligand

International Nuclear Information System (INIS)

Booysen, I.; Gerber, T. I. A.; Hosten, E.; Mayer, P.

2008-01-01

The rhenium(I) compound fac-[Re(CO) 3 (daa)]. Hpab.H 2 O (Hpab N,N'-(l,2-phenylene)bis(2'-aminobenzamide); Hdaa 2-amino-N-(2-aminophenyl)benzamide) was synthesized from the reaction of [Re(CO) 5 ,Br] with two equivalent of Hpab in toluene. The monoanionic tridentate ligand daa was formed by the rhenium-mediated cleavage of an amido N-C bond of the potentially tetradentate ligand Hpab. The compound was characterized by IR spectroscopy and X-ray crystallography, and daa is coordinated as a diamino amide via three nitrogen-donor atoms

Evaluation of molybdenum and its alloys

International Nuclear Information System (INIS)

Lundberg, L.B.

1981-01-01

The choice of pure molybdenum as the prime candidate material for space reactor core heat pipes is critically examined. Pure molybdenum's high ductile-brittle transition temperature appears to be its major disadvantage. The candidate materials examined in detail for this application include low carbon arc-cast molybdenum, TZM-molybdenum alloy, and molybdenum-rhenium alloys. Published engineering properties are collected and compared, and it appears that Mo-Re alloys with 10 to 15% rhenium offer the best combination. Hardware is presently being made from electron beam melted Mo-13Re to test this conclusion

Radianttrademark Liquid Radioisotope Intravascular Radiation Therapy System

International Nuclear Information System (INIS)

Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F. Jr.; Litvack, F.

1998-01-01

RADIANTtrademark is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid β-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid β-source is Rhenium-188 in the form of sodium perrhenate (NaReO 4 ), Rhenium-188 is primarily a β-emitter with a physical half-life of 17.0 hours. The maximum energy of the β-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Championtrademark over-the-wire, and TNTtrademark rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors

Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System

Energy Technology Data Exchange (ETDEWEB)

Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F., Jr.; Litvack, F.

1998-01-16

RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Champion{trademark} over-the-wire, and TNT{trademark} rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors.

188Re-microspheres of albumin - the potential preparation for radiotherapy

International Nuclear Information System (INIS)

Dyomin, D.N.; Petriev, V.M.

2000-01-01

In this paper author describe preparation the albumin microspheres labelled with rhenium-188. We undertake an attempt to develop kits to the generator of rhenium-188 on the basis of albumin microspheres for radiotherapy of both oncological and non-oncological diseases. Microspheres, rhenium-188 with sizes 1 0-20 micron for treatment of rheumatoid arthritis (damage of large and intermediate joints), intraperitoneal administration and intrapleural administration at metastases covering a cavity. Microspheres, Re-188 with sizes 40-60 micron for treatment of disseminated kidney cancer (intraarterial, selectively), intratumoral administration to damaged nodules less than 2-3 cm. Microspheres, Re-188 with sizes 80-100 micron for large neoplasms and metastases of liver (intraarterial, selectively), intratumoral administration to damaged nodules with sizes over 3 cm. Preparation of albumin microspheres is carried out by thermal denaturation of protein in vegetable oil. Microspheres are obtained with the necessary range of sizes by ultrasonic fractionation. At our laboratory the method of preparation of albumin microspheres with any sizes of particles (from 5 -10 up to 800 -1000 microns) has been developed. (authors)

Rhenium–platinum antitumor systems

Directory of Open Access Journals (Sweden)

A. V. Shtemenko

2017-04-01

Full Text Available This review provides an overlook of design (in short, antitumor and other biological activity of quadruple-bonded cluster dirhenium(III compounds and their synergism with cisplatin. In particular, we describe the work of the rhenium-platinum antitumor system (introduction of rhenium and platinum compounds. Among known metal-based anticancer drugs and drug candidates dirhenium(III compounds differ profoundly due to their strong antiradical and antioxidant properties determined by quadruple bond unsaturation. Such advantages of metal complexes as more expressed redox chemical propertie should be exploited for creating more efficient anticancer drugs. Combination of drugs leads to synergistic effects and/or to lowe­ring toxicity of platinides and is very promising in cancer chemotherapy. The review covers the follo­wing items: design of quadruple bonded dirhenium(III clusters, their spectral and antiradical properties (in short; interaction of the dirhenium(III compounds with lipids and formation of liposomes; interaction of the dirhenium(III compounds with erythrocytes and their antihemolytic activity in the models of hemolytic anemia; anticancer activity of dirhenium clusters and work of the rhenium-platinum antitumor system; antianemic and antioxidant properties of the dirhenium(III compounds in the model of tumor growth; interaction of the dirhenium(III compounds with nucleobases and DNA. Some modern trends in the field of bioinorganic and medicinal chemi­stry are also considered regarding their connection to the rhenium-platinum system efficiency: use of combinational therapy and nanomaterials; involvement of some biologically active ligands and redox-activation strategy, etc.

Coulomb-nuclear interference measurements of 168Yb, 176Hf, 178Hf, and 180Hf and lifetime measurements in 186Hg

International Nuclear Information System (INIS)

Nettles, W.G.

1979-01-01

Alpha scattering measurements were performed at center-of-mass energies near the Coulomb barrier. These energies allow for nuclear as well as pure Coulomb forces to play a significant role in the excitation process. The interference of these two forces is very sensitive to the sign of the E4 ground-state moment, whereas pure Coulomb excitation is not. Systematics of the E4 moments of the rare earth mass region indicate a transition in the magnitude and sign of the reduced matrix element of the M(E4) operator between 0 + and 4 + states from small and positive to large and negative between Yb and W. Previous Coulomb-nuclear interference measurements show that this reduced matrix element for 180 Hf is large and negative. The present results agree with that conclusion. It is also shown that the above reduced matrix element for 178 Hf, like that of 180 Hf, is large and negative. The small and positive moment (matrix element) for 168 Yb is seen to be consistent with the experimental data. No conclusions are drawn for the E4 moment in 176 Hf. The measurement of nuclear lifetimes shorter than 500 ps requires the use of plastic scintilltor detectors. These detectors, however have very poor energy resolution. A system is described that uses plastic scintillators with a magnetic lens spectrometer for energy selection. The system was used to measure the lifetime of the 522-keV 0 + sate in 186 Hf. A data analysis method using higher-order distribution moments is also presented

Evaluation of VVER-1200/V-491 reactor pressure vessel integrity during large break LOCA along with SBO using MELCOR 1.8.6

International Nuclear Information System (INIS)

Bui Thi Hoa; Tran Chi Thanh

2015-01-01

After Fukushima accident and stress test recommended by IAEA for existing reactors, higher safety requirements are enforced upon nuclear power plants during design extension and severe accident conditions. Based on those arguments, Vietnam Government requests a lot of effective safety solutions, in designs proposed for the nuclear power plants in Ninh Thuan province of Vietnam, which can prevent the accident progression toward severe accidents and mitigate severe accident consequences. One of safety requirements is related to delay time of core melt during design extension condition. Especially, if the worst case of accidents occurs, the reactor vessel integrity must be maintained at least 24 hours from the beginning of the accident. With the aim at investigation of Reactor Pressure Vessel (RPV) integrity, in this study, MELCOR 1.8.6 code is used to evaluate the integrity of RPV lower head for VVER-1200/V-491 reactor during a Large Break Loss of Coolant Accident (LBLOCA) in combination with Station Blackout (SBO) event. The study figures out several parameters related to melt down progress such as: rupture position and rupture timing, the amount of hydrogen generated. Availability of the second stage hydro-accumulators (HA2) in the VVER-1200/V-491 is assumed as an additional improvement to delay the timing of core melt as well as to maintain the vessel integrity for long-term. (author)

Platinum-group elements and gold in base metal sulfides, platinum-group minerals, and Re-Os isotope compositions of the Uitkomst complex, South Africa

Czech Academy of Sciences Publication Activity Database

Trubač, Jakub; Ackerman, Lukáš; Gauert, Ch.; Ďurišová, Jana; Hrstka, Tomáš

2018-01-01

Roč. 113, č. 2 (2018), s. 439-461 ISSN 0361-0128 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : binary alloys * copper compounds * economic geology * gold * iridium * isotopes * ore deposits * osmium * palladium * platinum * platinum metals * pyrites * Rhenium * rhenium alloys * ruthenium * solid solutions * sulfur compounds * crustal materials * mass-balance calculations * massive sulfides * mineralized zone * monosulfide solid solutions * platinum group elements * platinum group elements (PGEs) * platinum group minerals Subject RIV: DB - Geology ; Mineralogy; AC - Archeology, Anthropology, Ethnology (ARUB-Q) OBOR OECD: Geology; Archaeology (ARUB-Q) Impact factor: 2.519, year: 2016

Production of nanocrystalline metal powders via combustion reaction synthesis

Science.gov (United States)

Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.; Kim, Jin Yong

2017-10-31

Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

The therapeutic threesome, Iodine 131, Lutetium-111 and Rhenium-188 Radionuclide Trifecta

International Nuclear Information System (INIS)

Turner, J.H.

2007-01-01

intervals of 7 - 11 weeks, in 10 patients at Fremantle Hospital and 7 patients at Erasmus Medical Centre. A multicentre international physician-sponsored randomised controlled trial of 177 Lu octreotate with or without capecitabine will commence in 2008, given that toxicity of combined chemotherapy and radiopeptide therapy is no greater than 177 Lu octreotate alone. 3. Rhenium-188 Lipiodol Hepatocellular carcinoma is the cancer which kills more people in Asia than any other malignancy and if unresectable is incurable. Effective palliation, which may increase survival, has been demonstrated with intrahepatic arterial administration of 131 I-lipiodol (6) and there are even greater potential benefits with 188 Re-lipiodol (7). We are currently testing a commercial prototype of semiautomated shielded synthesis box (Comecer, Castel- bolognese, Italy) for preparation of sterile 188 Re-lipiodol, for eventual installation in radiopharmacies throughout Asia, to provide cost-effective, safe treatment of hepatocellular carcinoma. Given the advent of the 188 W/ 188 Re generator, other therapeutic radio-pharmaceuticals such as 188 Re- HEDP for bone pain palliation of skeletal metastases, 188 Re colloid for radiation synovectomy and 188 Re antibodies for internalizing radioimmunotherapy would be available in-house in radiopharmacies throughout the world, to facilitate cost-effective incorporation of therapeutic nuclear oncology into mainstream clinical management of cancer. (author)

Phase I/II trials of {sup 186}Re-HEDP in metastatic castration-resistant prostate cancer: post-hoc analysis of the impact of administered activity and dosimetry on survival

Energy Technology Data Exchange (ETDEWEB)

Denis-Bacelar, Ana M.; Chittenden, Sarah J.; Divoli, Antigoni; Flux, Glenn D. [The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, Joint Department of Physics, London (United Kingdom); Dearnaley, David P.; Johnson, Bernadette [The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, Division of Radiotherapy and Imaging, London (United Kingdom); O' Sullivan, Joe M. [Queen' s University Belfast, Centre for Cancer Research and Cell Biology, Belfast (United Kingdom); McCready, V.R. [Brighton and Sussex University Hospitals NHS Trust, Department of Nuclear Medicine, Brighton (United Kingdom); Du, Yong [The Royal Marsden Hospital NHS Foundation Trust, Department of Nuclear Medicine and PET/CT, London (United Kingdom)

2017-04-15

To investigate the role of patient-specific dosimetry as a predictive marker of survival and as a potential tool for individualised molecular radiotherapy treatment planning of bone metastases from castration-resistant prostate cancer, and to assess whether higher administered levels of activity are associated with a survival benefit. Clinical data from 57 patients who received 2.5-5.1 GBq of {sup 186}Re-HEDP as part of NIH-funded phase I/II clinical trials were analysed. Whole-body and SPECT-based absorbed doses to the whole body and bone lesions were calculated for 22 patients receiving 5 GBq. The patient mean absorbed dose was defined as the mean of all bone lesion-absorbed doses in any given patient. Kaplan-Meier curves, log-rank tests, Cox's proportional hazards model and Pearson's correlation coefficients were used for overall survival (OS) and correlation analyses. A statistically significantly longer OS was associated with administered activities above 3.5 GBq in the 57 patients (20.1 vs 7.1 months, hazard ratio: 0.39, 95 % CI: 0.10-0.58, P = 0.002). A total of 379 bone lesions were identified in 22 patients. The mean of the patient mean absorbed dose was 19 (±6) Gy and the mean of the whole-body absorbed dose was 0.33 (±0.11) Gy for the 22 patients. The patient mean absorbed dose (r = 0.65, P = 0.001) and the whole-body absorbed dose (r = 0.63, P = 0.002) showed a positive correlation with disease volume. Significant differences in OS were observed for the univariate group analyses according to disease volume as measured from SPECT imaging of {sup 186}Re-HEDP (P = 0.03) and patient mean absorbed dose (P = 0.01), whilst only the disease volume remained significant in a multivariable analysis (P = 0.004). This study demonstrated that higher administered activities led to prolonged survival and that for a fixed administered activity, the whole-body and patient mean absorbed doses correlated with the extent of disease, which, in turn, correlated

Search for technetium in natural tin metallurgical residues

Energy Technology Data Exchange (ETDEWEB)

Parker, C.W.

1996-07-01

Possible instability of baryons inside the nuclei might result in accumulation of rare isotopes in natural ores. In this respect, isotopes of technetium have certain advantages that can be useful in the search for technetium in nonradioactive ores by chemical methods. In this paper, we review the history of technetium research and discuss a new approach to the search for natural technetium associated with tin ores which appears to offer a rare possibility of discovering a smelting operation by-product such as flue dust, in which the volatile technetium heptoxide (Tc{sub 2}O{sub 7}), like rhenium heptoxide (Re{sub 2}O{sub 7}), would be expected to concentrate. Our concept of a search for technetium in these materials would be based on the assumption that traces of rhenium could occur in the ore and could be traced most easily by neutron activation of small samples. Such a procedure would confirm that an enrichment from the ore to the flue dust actually occurs with the rhenium and therefore should occur with technetium. Furthermore, this occurrence should identify the best location to search for technetium.

Nuclear medicine program progress report for quarter ending December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Knapp, F.F. Jr.; Beets, A.L.; Boll, R.; Luo, H.; McPherson, D.W.; Mirzadeh, S.

1997-03-20

In this report the authors describe the use of an effective method for concentration of the rhenium-188 bolus and the results of the first Phase 1 clinical studies for bone pain palliation with rhenium-188 obtained from the tungsten-188/rhenium-188 generator. Initial studies with therapeutic levels of Re-188-HEDP at the Clinic for Nuclear Medicine at the University of Bonn, Germany, have demonstrated the expected good metastatic uptake of Re-188-HEDP in four patients who presented with skeletal metastases from disseminated prostatic cancer with good pain palliation and minimal marrow suppression. In addition, skeletal metastatic targeting of tracer doses of Re-188(V)-DMSA has been evaluated in several patients with metastases from prostatic cancer at the Department of Nuclear Medicine at the Canterbury and Kent Hospital in Canterbury, England. In this report the authors also describe further studies with the E-(R,R)-IQNP ligand developed in the ORNL Nuclear Medicine Program as a potential imaging agent for detection of changes which may occur in the cerebral muscarinic-cholinergic receptors (mAChR) in Alzheimer`s and other diseases.

Radiosynovectomy in the treatment of arthritis

International Nuclear Information System (INIS)

Liepe, K.

2007-01-01

Full text: Radiosynovectomy is a useful therapeutic option that involves radiopharmaceutical injections into joints, especially to treat rheumatoid arthritis. The indications included different kinds of arthritis, such as rheumatoid arthritis, psoriatic arthritis, Bechterew's disease, hemophiliac arthritis, osteoarthritis, but also patients with joint prosthesis and synovial effusion. There are three commercial available radiopharmaceuticals for the treatment: yttrium-90 for the knee (185 to 250 MBq), rhenium-186 for larger joints (shoulder and hip with 111 MBq; elbow, wrist, ankle joint with 74 MBq) and erbium- 169 for smaller joints (acromioclavicular joint with 37 MBq, thumb base and MTP I with 30 MBq, MCP and MTP II-V with 22 MBq, PIP with 18.5 MBq, and DIP with 15 MBq, respectively). Decisive for the treatment is a positive sign for arthritis in the two-phase bone scan with 99mTc- HMDP (high uptake in the blood pool phase). Only for radiosynovectomy in the knee an ultrasound with an evidence of effusion is sufficient. Side effects by the treatment are rare, such as temporary radiation or crystal synovitis, tissue necrosis (extra-articular fraction or intraarticular), joint infection (1 of 35,000 joints) or effects due to the immobilization (thrombosis, pulmonary embolism (immobilization of the knee), lymph edema or loss of motion. In the treatment of the knee, a prophylaxis with heparin is necessary to protect the patients for pulmonary embolism. The radiation absorbed dose to the patients are low because a low leakage rate from the treated joint (lymphogenic uptake of 1.8%ID (0.45 to 4.78). These leads to a radiation exposure to the testis of 0.1mSv (0.05 to 0.18) and to the ovary of 0.2 mSv (0.1 to 0.38). Significantly is the radiation exposure of the physician, here especially at the finger pulp. A high beta dose of 22.1 μSv/MBq for the forefinger was observed using only a syringe protection in treatments of knees ( 90 Y), this resulted in a annual

Friction stir weld tools having fine grain structure

Science.gov (United States)

Grant, Glenn J.; Frye, John G.; Kim, Jin Yong; Lavender, Curt A.; Weil, Kenneth Scott

2016-03-15

Tools for friction stir welding can be made with fewer process steps, lower cost techniques, and/or lower cost ingredients than other state-of-the-art processes by utilizing improved compositions and processes of fabrication. Furthermore, the tools resulting from the improved compositions and processes of fabrication can exhibit better distribution and homogeneity of chemical constituents, greater strength, and/or increased durability. In one example, a friction stir weld tool includes tungsten and rhenium and is characterized by carbide and oxide dispersoids, by carbide particulates, and by grains that comprise a solid solution of the tungsten and rhenium. The grains do not exceed 10 micrometers in diameter.

Thermolysis of salts of [ReCl6]2- and [ReBr6]2- anions

International Nuclear Information System (INIS)

Gubanov, A.I.; Korenev, S.V.; Gromilov, S.A.; Shubin, Yu.V.

2003-01-01

Thermal decomposition of the [Pd(NH 3 ) 4 ][ReG 6 ], [Pt(NH 3 ) 4 ][ReG 6 ], (NH 4 ) 2 [ReG 6 ] complexes, where G = Cl, Br, was studied in the inert atmosphere. Certain regularities of the thermolysis were established. Finished products of the thermolysis of binary complexes in the inert atmosphere were demonstrated to be two-phase systems containing two solid solutions - one on the basis of the platinum (palladium) fcc-lattice, another - on the basis of the rhenium hcp lattice. One-phase solid palladium - rhenium solutions were established to be obtained during reduction of the studied complexes in the hydrogen atmosphere [ru

Two structure types based on Si6O15 rings: synthesis and structural and spectroscopic characterisation of Cs1.86K1.14DySi6O15 and Cs1.6K1.4SmSi6O15

International Nuclear Information System (INIS)

Wierzbicka-Wieczorek, Maria; Goeckeritz, Martin; Kolitsch, Uwe; Lenz, Christoph; Giester, Gerald

2015-01-01

The silicate Cs 1.86 K 1.14 DySi 6 O 15 represents a mixed tetrahedral-octahedral framework structure type based on roughly circular Si 6 O 15 rings and isolated DyO 6 octahedra. The silicate Cs 1.6 K 1.4 SmSi 6 O 15 has a layered atomic arrangement built from corrugated Si 6 O 15 layers containing four-, six- and eight-membered rings. The layers are connected by isolated SmO 6 octahedra to form a mixed tetrahedral-octahedral framework. This structure shows a close structural relationship to β-K 3 NdSi 6 O 15 and a less close one to dehydrated elpidite (Na 2 ZrSi 6 O 15 ). In both structures, Cs/K atoms occupy large voids. The silicates were obtained through high-temperature flux syntheses. Their crystal structures have been determined from single-crystal X-ray diffraction data. Cs 1.86 K 1.14 DySi 6 O 15 crystallises in R32 (no. 155) with a = 13.896(2), c = 35.623(7) Aa and V = 5957.2(17) Aa 3 , whereas Cs 1.6 K 1.4 SmSi 6 O 15 crystallises in Cmca (no. 64) with a = 14.474(3), b = 14.718(3), c = 15.231(3) Aa and V = 3244.7(11) Aa 3 . The Dy 3+ and Sm 3+ cations present in the silicates cause PL emission bands in the visible yellow-to-orange spectral range. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

THE INTERPRETATION TO BE ACCORDED TO THE TERM "BENEFITS" IN SECTION 186(2(a OF THE LRA CONTINUES: APOLLO TYRES SOUTH AFRICA (PTY LIMITED V CCMA (DA1/11 [2013] ZALAC 3

Directory of Open Access Journals (Sweden)

Shamier Ebrahim

2014-04-01

Full Text Available The interpretation to be accorded to the term benefits in section 186(2(a of the Labour Relations Act 66 of 1995 (the "LRA" has come before the Courts on several occasions. In terms of section 186(2(a of the LRA any unfair act or omission by an employer relating to the provision of benefits to an employee falls within the ambit of an unfair labour practice. In Schoeman v Samsung Electronics SA (Pty Ltd the Labour Court (the "LC" held that the term benefit could not be interpreted to include remuneration. It stated that a benefit is something extra from remuneration. In Gaylard v Telkom South Africa Ltd the LC endorsed the decision in Samsung and held that if benefits were to be interpreted to include remuneration then this would curtail strike action with regard to issues of remuneration. In Hospersa v Northern Cape Provincial Administration the issue regarding the interpretation of the term benefits did not relate to whether or not it included remuneration but rather to whether it included a hope to create new benefits which were non-existent. The Labour Appeal Court (the "LAC" held that the term benefits refers only to benefits which exist ex contractu or ex lege but does not include a hope to create new benefits. The LAC adopted this approach in order to maintain the separation between a dispute of interest and one of mutual interest, the latter being subject to arbitration whilst the former is subject to the collective bargaining process (strike action. In Protekon (Pty Ltd v CCMA the LC disagreed with the reasoning in Samsung and held that the term remuneration as defined in section 213 of the LRA is wide enough to include payment to employees, which may be described as benefits. The LC remarked that the statement in Samsung to the effect that a benefit is something extra from remuneration goes too far. It further remarked that the concern that the right to strike would be curtailed if remuneration were to fall within the ambit of benefits

Ternary self-assemblies in water

DEFF Research Database (Denmark)

Hill, Leila R.; Blackburn, Octavia A.; Jones, Michael W.

2013-01-01

The self-assembly of higher order structures in water is realised by using the association of 1,3-biscarboxylates to binuclear meta-xylyl bridged DO3A complexes. Two dinicotinate binding sites are placed at a right-angle in a rhenium complex, which is shown to form a 1 : 2 complex with α,α'-bis(E......The self-assembly of higher order structures in water is realised by using the association of 1,3-biscarboxylates to binuclear meta-xylyl bridged DO3A complexes. Two dinicotinate binding sites are placed at a right-angle in a rhenium complex, which is shown to form a 1 : 2 complex with α...

Critical evaluation of molybdenum and its alloys for use in space reactor core heat pipes

International Nuclear Information System (INIS)

Lundberg, L.B.

1981-01-01

The choice of pure molybdenum as the prime candidate material for space reactor core heat pipes is examined, and the advantages and disadvantages of this material are brought into focus. Even though pure molybdenum heat pipes have been built and tested, this metal's high ductile-brittle transition temperature and modest creep strength place significant design restrictions on a core heat pipe made from it. Molybdenum alloys are examined with regard to their promise as potential replacements for pure molybdenum. The properties of TZM and molybdenum-rhenium alloys are examined, and it appears that Mo-Re alloys with 10 to 15 wt % rhenium offer the most advantage as an alternative to pure molybdenum in space reactor core heat pipes

Perspectives of 99mTc chemistry and radiopharmacy: strategies, building blocks and targets

International Nuclear Information System (INIS)

Alberto, R.

2007-01-01

Technetium chemistry, both fundamental and applied are required to a larger extent in order to keep the essential role of this element in radiopharmacy alive. After an introduction, highlighting the situation in general from research and market aspects, new strategies will be proposed in which technetium and rhenium play an essential role which can not be taken over by other radionuclides such as 11 C or 18 F. Furthermore, currently available and potential future building blocks in technetium chemistry and their relationship to the new strategies as well as characteristics of new precursors will be discussed and compared to each other. Targets and targeting molecules, again in the context of strategies unique for technetium (and rhenium) are in the focus of the last part. With respect of retaining a unique role, it is obvious that any future technetium or rhenium labelled biomolecule should have potential to therapy or be applied in the immediate context of therapy, as e.g. for the early assessment of success in chemotherapy. All these aspects emphasize a role of inorganic technetium chemistry which goes far beyond simple labelling strategies. To underline the importance of fundamental chemistry, we will present and discuss some examples with nuclear targeting agents, amino acids and vitamin B12. (author)

Final Report Technetium Monitor

International Nuclear Information System (INIS)

Spencer, W.A.

2003-01-01

The Hanford River Protection Project Waste Treatment Plant (WTP) is required by the current contract to remove radioactive technetium FR-om stored caustic nuclear waste solutions. The Savannah River Technology Center (SRTC) has worked with typical envelopes of these wastes to optimize the removal process. To support the studies, SRTC developed a rapid on-line remote analyzer to monitor technetium and rhenium levels in solutions as well as track other metals in the solutions through the process operations. Rhenium was used as a non-radioactive substitute for technetium in process development studies. The remote monitor was based on inductively coupled plasma emission spectroscopy (ICPES). Fiber optic cable and extended RF cabling removed the plasma source FR-om the spectrometer and instrument electronics

A systematic chemical separation for thermal neutron activation analysis of seven noble metals in rock

International Nuclear Information System (INIS)

Ayabe, Muneo

1980-01-01

A method for the systematic activation analysis of seven noble metals - ruthenium, silver, rhenium, osmium, iridium, platinum and gold - in rocks were developed and examined with radiotracers and irradiated rock samples. After the fusion of the irradiated rock sample with sodium hydroxide and sodium peroxide, 10% sodium sulfide solution is added and rhenium is extracted with pyridine-benzene mixture from 6N sodium hydroxide solution. From the hydroxide-sulfide precipitate fraction, ruthenium and osmium are distilled as tetroxides, silver is precipitated as chloride, gold is extracted with ethyl acetate, and iridium and platinum are extracted with diantipyrylmethane. Each fraction is purified and subjected to the γ-ray spectrometry. Chemical yields for the elements are more than 60%. Determination limits are given for the seven elements. (author)

A new ion source for fission-yield measurements of rare-earth isotopes

International Nuclear Information System (INIS)

Pilzer, E.H.; Engler, G.

1987-01-01

A new integrated target-ion source for fission-yield measurements of rare-earth isotopes has been developed for the Soreq on-line isotope separator (SOLIS). The source is heated by electron bombardment to a temperature of 2400 0 C and ionization takes place in a rhenium hot cavity. To overcome the problem of impurities which reduce the ionization efficiency, a ZrC disk was inserted in the cavity. Calculations show that because of its high thermionic emission, ZrC enhances ionization performance considerably. For example, in the presence of 10 -5 mbar of cesium impurity, the ionization efficiency of a rhenium hot cavity for the rare-earth terbium is 6%. However, with a ZrC disk, the efficiency increases to 97%. (orig.)

[Management of Uninhabitable Homes - Investigation of 186 Cases of Hoarding, Domestic Neglect and Squalor in Dortmund (Germany)].

Science.gov (United States)

Lenders, T; Kuster, J; Bispinck, R

2015-12-01

To develop an intervention concept for the management of uninhabitable homes. Retrospective analysis of 186 cases of the community mental health service in Dortmund (Germany) presenting with a destitute situation of the domestic environment as core problem. All patients suffered from psychiatric illnesses, mainly from addiction (F1: 41 %), psychosis (F2: 17 %), depression (F3: 17 %), and hoarding disorder (F63.8: 12 %). Main socio-demographic characteristics of our sample are: middle age (45-65 years, 48 %), male gender (73 %), isolated situation (only 7 % married, 84 % living alone), normal schooling (only 4 % without completion of schooling, 7 % attended a school for special needs), after initial integration into employment nearly all patients suffered vocational disintegration (5 % employed, 44 % unemployment benefit, 7 % welfare, 39 % pension or invalidity benefit).Psychosocial interventions differed between the 4 main diagnostic groups: F1: treatment of dependence (rehab) and treatment of concomitant somatic diseases; F2: admission to a psychiatric hospital and implementation of guardianship; F3: mediation of conflicts with neighbours/landlords and implementation of guardianship; F63.8: direct practical help by members of the community mental health team and organisation of home help/waste disposal. In all diagnostic groups, acceptance of help was impaired due to social withdrawal, resistance and psychiatric symptoms. At 13 %, compliance with help and interventions was lowest in the hoarder group (F1: 27 %, F2: 26 %, F3: 38 %). Consequently, in this group the poor outcome categories "nothing accomplished" and "lost flat/eviction" were more frequent (44 %, F1: 27 %, F2: 26 %, F3: 38 %). Concurrent to the deterioration of the domestic situation, patients suffer vocational disintegration as well as family and social isolation. Uninhabitable homes occur in the course of various severe and chronic psychiatric diseases

36 CFR 223.186 - Definitions.

Science.gov (United States)

2010-07-01

... refers to the geographic area within which logs from any origin have neither been exported nor..., association, or other legal entity and includes any subsidiary, subcontractor, parent company, and business... factors, including but not limited to common ownership, common management, common facilities, and...

186 | P a g e

African Journals Online (AJOL)

Fr. Ikenga

pollution. This disorder apparently manifests in the damage of the auricle as an initial sign. Experts contend that noise is one of the most dangerous and silent environmental pollutions as its effects on human body system could ..... or integrity. …16 ... Noise Directives empowered EU to identity noise pollution levels and to.

30 CFR 18.6 - Applications.

Science.gov (United States)

2010-07-01

... meet existing requirements for minimum bolt size and spacing and for minimum wall, cover, and flange... wall, they shall be of explosion-proof construction. Insulated bushings or studs shall not be installed...

Nuclear Structure of 186Re

Science.gov (United States)

2016-12-24

equipotential surfaces defining the shapes of quadrupole-deformed nuclei are shown in Figure 3, in which the e↵ects of varying and are... equipotential surfaces in deformed nuclei, with the axis of nuclear symmetry identified as the z axis. The spherical shape has = 0, while the oblate...Equation (11) are seen to represent the mass-energy contained in the volume of the nucleus, adjusted for the surface tension and the Coulomb

Placental weight in the first pregnancy and risk for preeclampsia in the second pregnancy: A population-based study of 186 859 women.

Science.gov (United States)

Dypvik, Johanne; Larsen, Sandra; Haavaldsen, Camilla; Jukic, Anne M; Vatten, Lars J; Eskild, Anne

2017-07-01

To study whether placental weight in the first pregnancy is associated with preeclampsia in the second pregnancy. In this population-based study, we included all women with two consecutive singleton pregnancies reported to the Medical Birth Registry of Norway during 1999-2012 (n=186 859). Placental weight in the first pregnancy was calculated as z-scores, and the distribution was divided into five groups of equal size (quintiles). We estimated crude and adjusted odds ratios with 95% confidence intervals for preeclampsia in the second pregnancy according to quintiles of placental weight z-scores in the first pregnancy. The 3rd quintile was used as the reference group. Among women without preeclampsia in the first pregnancy, 1.4% (2507/177 149) developed preeclampsia in the second pregnancy. In these women, the risk for preeclampsia in the second pregnancy was associated with placental weight in the first pregnancy in both lowest (crude odds ratio (cOR) 1.30, 95% confidence interval (CI); 1.14-1.47) and highest quintile (cOR 1.20, 95% CI; 1.06-1.36). The risk associated with the highest quintile of placental weight was confined to term preeclampsia. Among women with preeclampsia in the first pregnancy, 15.7% (1522/9710) developed recurrent preeclampsia, and the risk for recurrent preeclampsia was associated with placental weight in lowest quintile in the first pregnancy (cOR 1.30, 95% CI; 1.10-1.55). Adjustment for interval between pregnancies, maternal diabetes, age, and smoking in the first pregnancy did not alter these estimates notably. Placental weight in the first pregnancy might help to identify women who could be at risk for developing preeclampsia in a second pregnancy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Use of a Tantalum Liner to Reduce Bore Erosion and Increase Muzzle Velocity in Two-Stage Light Gas Guns

Science.gov (United States)

Bogdanoff, David W.

2015-01-01

Muzzle velocities and gun erosion predicted by earlier numerical simulations of two stage light gas guns with steel gun tubes were in good agreement with experimental values. In a subsequent study, simulations of high performance shots were repeated with rhenium (Re) gun tubes. Large increases in muzzle velocity (2 - 4 km/sec) were predicted for Re tubes. In addition, the hydrogen-produced gun tube erosion was, in general, predicted to be zero with Re tubes. Tantalum (Ta) has some mechanical properties superior to those of Re. Tantalum has a lower modulus of elasticity than Re for better force transmission from the refractory metal liner to an underlying thick wall steel tube. Tantalum also has greater ductility than Re for better survivability during severe stress/strain cycles. Also, tantalum has been used as a coating or liner in military powder guns with encouraging results. Tantalum has, however, somewhat inferior thermal properties to those of rhenium, with a lower melting point and lower density and thermal conductivity. The present study was undertaken to see to what degree the muzzle velocity gains of rhenium gun tubes (over steel tubes) could be achieved with tantalum gun tubes. Nine high performance shots were modeled with a new version of our CFD gun code for steel, rhenium and tantalum gun tubes. For all except the highest velocity shot, the results with Ta tubes were nearly identical with those for Re tubes. Even for the highest velocity shot, the muzzle velocity gain over a steel tube using Ta was 82% of the gain obtained using Re. Thus, the somewhat inferior thermal properties of Ta (when compared to those of Re) translate into only very slightly poorer overall muzzle velocity performance. When this fact is combined with the superior mechanical properties of Ta and the encouraging performance of Ta liners/coatings in military powder guns, tantalum is to be preferred over Re as a liner/coating material for two stage light gas guns to increase muzzle

Expedient multi-step synthesis of organometallic complexes of Tc and Re in high effective specific activity. A new platform for the production of molecular imaging and therapy agents.

Science.gov (United States)

Causey, Patrick W; Besanger, Travis R; Schaffer, Paul; Valliant, John F

2008-09-15

For over thirty years, instant labeling kits which involve no purification steps have been the only method used to prepare (99m)Tc radiopharmaceuticals for clinical studies. To address the limitations imposed by instant kits, which is hindering the development of molecularly targeted Tc- and Re-based imaging and therapy agents, a new strategy for the rapid multistep synthesis and purification of organometallic technetium-based molecular probes and corresponding rhenium-based therapeutic analogues was developed. Beginning with MO4(-) (M = (99m)Tc, (186/188)Re), the carbonyl precursor [M(CO)3(H2O)3](+) was synthesized in 3 min in quantitative yield in a microwave reactor. A dipicolyl ligand was added and the chelate complex was formed in high yield in 2 min using microwave heating at 150 degrees C. This was followed by a new purification strategy to remove unlabeled ligand which entailed using a copper resin/C18 solid phase extraction protocol giving the desired product in greater than 78% decay corrected yield (dcy). Conversion to the corresponding succinimidyl active ester was achieved following a 5 min microwave irradiation at 120 degrees C and C18 solid phase extraction purification in 60% dcy. A series of amides were prepared subsequently by microwave heating at 120 degrees C for 5 min producing the desired targets in greater than 86% dcy. The reported method represents a move away from traditional instant kits toward more versatile platform synthesis and purification technologies that are better suited for producing modern molecular imaging and therapy agents.

The oxidation of ReCl_5 with oleum: synthesis and crystal structure of Re_2O_4Cl_4(SO_4)

International Nuclear Information System (INIS)

Betke, Ulf; Wickleder, Mathias S.

2012-01-01

The reaction of ReCl_5 and fuming sulfuric acid (25 % SO_3) in a sealed glass tube at 200 C led to red, needle shaped single crystals of Re_2O_4Cl_4(SO_4) (monoclinic, C2/c, a = 1501.8(2) pm, b = 1545.9(2) pm, c = 945.18(8) pm, β = 98.761(9) , Z = 8). In the crystal structure the [ReO_2] moieties are linked by [SO_4]"2"- tetrahedra to chains along the [101] direction. Each sulfate ion connects four rhenium atoms, additional two chloride ions complete the octahedral coordination sphere of each rhenium atom according to "1_∞[ReO_2_/_1Cl_2_/_1(SO_4)_2_/_4]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Diffusion of 99-technetium in bentonite under aerobic and anaerobic conditions

International Nuclear Information System (INIS)

Vecernik, P.; Jedinakova-Krizova, V.; Vokal, A.

2006-01-01

Diffusion experiments were performed with 99 Tc and Re (a model of technetium) in the form of pertechnetate and perrhenate in bentonite from the Rokle locality (Czech Republic). The through diffusion method was used, and the apparent diffusion coefficients (D a ) were evaluated. The effects of the particle mesh-size, bulk densities, and aerobic or anaerobic conditions on the diffusion were studied in view of the fact that oxidizing or reducing conditions influence the chemical forms of technetium and rhenium. In the presence of oxygen, technetium and rhenium occur in oxidation state VII, as anions which are soluble and mobile in the environment, whereas in reducing conditions they occur in lower oxidation states, mainly as insoluble oxides or hydroxides. Aerobic experiments were carried out in common laboratory conditions, anaerobic experiments were performed under nitrogen

Particle fuel bed tests

International Nuclear Information System (INIS)

Horn, F.L.; Powell, J.R.; Savino, J.M.

1985-01-01

Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

new polythiophenes with oligo(oxyethylene) side chains

African Journals Online (AJOL)

USER

2Department of Chemistry, University of Port Elizabeth, P.O. Box 1600, 6000 Port ... applications of rhenium radiopharmaceuticals in nuclear medicine[5, 6]. ... This report deals with the synthesis of complexes II, and their reactions with 2-.

Beta decay and rhenium cosmochronology

International Nuclear Information System (INIS)

Ashktorab, K.

1992-01-01

Among the problems which limit the use of the 187 Re/ 187 Os isobaric pair as a cosmochronometer for the age of the galaxy and the universe are the uncertainties in the partial half-lives of the continuum and bound state decays of 187 Re. While the total half-life of the decay is well established, the partial half-life for the continuum decay is uncertain, and several measurements are not compatible. A high temperature quartz proportional counter was used in this work to remeasure the continuum β - decay of 187 Re. The β endpoint energy for the decay of neutral 187 Re to singly ionized 187 Os of 2.75 ± 0.06 keV agrees with the earlier results. The corresponding half-life of (45 ± 3) x 10 9 years improves and agrees with the earlier measurement of Payne and Drever and refutes other measurements. Based on the new half-life for the continuum decay and a total half-life of (43.5 ± 1.3) x 10 9 years reported by Linder et al., the branching ratio for the bound state decay into discrete atomic states is estimated to be (3 ± 6)% in agreement with the most recent calculated theoretical branching ratio of approximately 1%. Anomalies in beta spectra reported by J.J. Simpson and others have been attributed to a 17 keV heavy-neutrino admixture. If confirmed, the implications from the existence of such a neutrino for particle and astrophysics would be significant. A multiwire open-quotes wall-lessclose quotes stainless steel proportional counter has been used in the present work to investigate the spectral shape of the β decay of 63 Ni. No anomalies in the spectral shape were observed which could be attributed to the presence of 17 keV heavy neutrino

Molybdenum-rhenium superconducting suspended nanostructures

Energy Technology Data Exchange (ETDEWEB)

Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio [Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom)

2014-06-09

Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50 nm and length 3 μm have a critical temperature of ≈6.5 K, which can increase by 0.5 K upon annealing at 400 °C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

1996 GRAMME activity report

International Nuclear Information System (INIS)

1997-01-01

This note draws a balance of the activities made at CEA-DEM within the frame of GRAMME collaboration. Results in six interest fields are presented: solidification, Mephisto program, transport phenomena, isothermal diffusion, rhenium alloys and instrumentation. (A.C.)

Tungsten wire and tubing joined by nickel brazing

Science.gov (United States)

1965-01-01

Thin tungsten wire and tungsten tubing are brazed together using a contacting coil of nickel wire heated to its melting point in an inert-gas atmosphere. This method is also effective for brazing tungsten to tungsten-rhenium parts.

Synthesis and characterization of a cerebral radiotracer

International Nuclear Information System (INIS)

Ben hamouda, Salem

2010-01-01

The development of nuclear medicine is based on research of new radiopharmaceuticals, in particular, relying on technetium-99m, the most used radioisotope in terms of availability and low cost. A similar study on Rhenium (185/187Re) is essential for monitoring physico-chemical studies due to the high specific activity of technetium-99m. During this work, we have synthesized and labeled with technetium the N-methyl-4-hydroxy piperidinyl ferrocenyl carboxylate. The marking is done by exchange of ligands between the iron group of ferrocene and tricabonyl technetium core. We have succeeded to synthesis the N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl rhenium (the molecular analogue of the technetium). We characterized it by MS, IR and NMR (1H, 13C) The structure of N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl technetium is well justified.

Directed light fabrication of refractory metals

International Nuclear Information System (INIS)

Lewis, G.K.; Thoma, D.J.; Nemec, R.B.; Milewski, J.O.

1997-01-01

Directed Light Fabrication (DLF) is a metal, rapid fabrication process that fuses metal powders to full density into a solid replica of a computer modeled component. It has been shown feasible for forming nearly any metal and also intermetallics to near net shape with a single process. DLF of refractory pure metals is feasible, bypassing the extensive series of conventional processing steps used for processing these high melting point materials. Tungsten, tantalum, and rhenium were processed and show a continuous resolidified microstructure. Porosity was a problem for the tantalum and rhenium powders produced by chemical reduction processes but not for the tungsten powder spherodized in a plasma arc. Chemical analysis of powder compared to the DLF deposit showed reductions in carbon, oxygen and hydrogen, indicating that process parameters may also be optimized for evolution of residual gases in the deposits

Synthesis of fluorinated ReCl(4,4'-R2-2,2'-bipyridine)(CO)3 complexes and their photophysical characterization in CH3CN and supercritical CO2.

Science.gov (United States)

Doherty, Mark D; Grills, David C; Fujita, Etsuko

2009-03-02

Two new CO(2)-soluble rhenium(I) bipyridine complexes bearing the fluorinated alkyl ligands 4,4'-(C(6)F(13)CH(2)CH(2)CH(2))(2)-2,2'-bipyridine (1a), and 4,4'-(C(8)F(17)CH(2)CH(2)CH(2))(2)-2,2'-bipyridine (1b) have been prepared and their photophysical properties investigated in CH(3)CN and supercritical CO(2). Electrochemical and spectroscopic characterization of these complexes in CH(3)CN suggests that the three methylene units effectively insulate the bipyridyl rings and the rhenium center from the electron-withdrawing effect of the fluorinated alkyl chains. Reductive quenching of the metal-to-ligand charge-transfer excited states with triethylamine reveals quenching rate constants in supercritical CO(2) that are only 6 times slower than those in CH(3)CN.

Volatility literature of chlorine, iodine, cesium, strontium, technetium, and rhenium; technetium and rhenium volatility testing

International Nuclear Information System (INIS)

Langowski, M.H.; Darab, J.G.; Smith, P.A.

1996-03-01

A literature review pertaining to the volatilization of Sr, Cs, Tc (and its surrogate Re), Cl, I and other related species during the vitrification of Hanford Low Level Waste (LLW) streams has been performed and the relevant information summarized. For many of these species, the chemistry which occurs in solution prior to the waste stream entering the melter is important in dictating their loss at higher temperatures. In addition, the interactive effects between the species being lost was found to be important. A review of the chemistries of Tc and Re was also performed. It was suggested that Re would indeed act as an excellent surrogate for Tc in non-radioactive materials testing. Experimental results on Tc and Re loss from sodium aluminoborosilicate melts of temperatures ranging from 900--1350 degrees C performed at PNL are reported and confirm that Re behaves in a nearly identical manner to that of technetium