Sorption of radionuclide technetium on minerals

International Nuclear Information System (INIS)

Li Min; Fan Xianhua; Wei Liansheng; Zhang Yingjie; Jiao Haiyang

2004-01-01

The study on adsorption behavior of technetium on antimonial minerals is performed in batch experiments and the influence of adsorption time, mineral granularity, solid-liquid ratio, initial concentration, pH value and reducing ion. On technetium adsorption are considered according to adsorption ratios of hepta valent and quadrivalent technetium on stibnite and antimony ocher, the results show that reduction of technetium from heptavelence to quadrivalence could improve adsorption ratios, which provide reference data for selecting buffer-backfill materials in high level rad waste deep geological diplosal. (author)

Dynamic iodide trapping by tumor cells expressing the thyroidal sodium iodide symporter

International Nuclear Information System (INIS)

Dingli, David; Bergert, Elizabeth R.; Bajzer, Zeljko; O'Connor, Michael K.; Russell, Stephen J.; Morris, John C.

2004-01-01

The thyroidal sodium iodide symporter (NIS) in combination with various radioactive isotopes has shown promise as a therapeutic gene in various tumor models. Therapy depends on adequate retention of the isotope in the tumor. We hypothesized that in the absence of iodide organification, isotope trapping is a dynamic process either due to slow efflux or re-uptake of the isotope by cells expressing NIS. Iodide efflux is slower in ARH-77 and K-562 cells expressing NIS compared to a thyroid cell line. Isotope retention half times varied linearly with the number of cells expressing NIS. With sufficient NIS expression, iodide efflux is a zero-order process. Efflux kinetics in the presence or absence of perchlorate also supports the hypothesis that iodide re-uptake occurs and contributes to the retention of the isotope in tumor cells. Iodide organification was insignificant. In vivo studies in tumors composed of mixed cell populations confirmed these observations

Radionuclide Basics: Technetium-99

Science.gov (United States)

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

Recovery of technetium from nuclear fuel wastes

International Nuclear Information System (INIS)

Carlin, W.W.

1975-01-01

Technetium is removed from aqueous, acidic waste solutions. The acidic waste solution is mixed with a flocculant, e.g., an alkaline earth metal hydroxide or oxide, to precipitate certain fission products. Technetium remains in solution and in the resulting supernatant alkaline aqueous phase. The supernatant alkaline aqueous phase is made acidic and electrolyzed in an electrolytic cell under controlled cathodic potential conditions to deposit technetium on the cathode. Elemental technetium is removed from the cathode. Technetium is separated from other plated fission product metals by extraction from an alkaline solution with an organic extractant, such as pyridine, having affinity for technetium. Technetium is separated from the organic extractant by steam distillation and the resulting aqueous phase treated with ammoniacal reagent to precipitate technetium as ammonium pertechnetate. The precipitate may be acidified to form an aqueous acidic solution of fission product metal values and the solution electrolyzed in an electrolytic cell under controlled cathodic potential conditions and at a potential sufficiently negative to plate out from the solution those fission product metals desired. The metal deposit is stripped from the cathode and stored until its radioactivity has diminished. (U.S.)

Electrochemistry of technetium

International Nuclear Information System (INIS)

Russell, C.D.; Alabama Univ., Birmingham

1982-01-01

Recent work on the electrochemistry of technetium is reviewed, covering the period 1973-1980. Topics include polarographic studies of aqueous pertechnetate, coulometric studies of aqueous pertechnetate at mercury cathodes, and electrochemistry of pertechnetate at solid electrodes. A review is also given of electrochemistry of other technetium compounds, non-aqueous systems, chemical redox reactions, and substitution reactions. Consideration is also given to studies of electrochemistry at tracer concentrations, electrolytic syntheses, standard electrode potentials, and electroanalytical methods. (author)

Sample preparation and characterization of technetium metal

International Nuclear Information System (INIS)

Minato, Kazuo; Serizawa, Hiroyuki; Fukuda, Kousaku; Itoh, Mitsuo

1997-10-01

Technetium-99 is a long-lived fission product with a half-life of about 2.1 x 10 5 years, which decays by β-emission. For the transmutation of 99 Tc, research on solid technetium was started. Technetium metal powder purchased was analyzed by X-ray diffraction, γ-ray spectrometry, and inductively coupled plasma-atomic emission spectrometry and -mass spectrometry. The lattice parameters obtained were agreed with the reported values. The metallic impurity was about 15 ppm, where aluminum and iron contributed mainly. No impurity nuclide with γ-emission was found. Using the technetium metal powder, button-, rod-, and disk-shaped samples of technetium metal were prepared by arc-melting technique. Thermal diffusivity of technetium metal was measured on a disk sample from room temperature to 1173 K by laser flash method. The thermal diffusivity decreased with increasing temperature though it was almost constant above 600 K. (author)

Determination of technetium-99 in environmental and radioactive waste samples

International Nuclear Information System (INIS)

Ferencova, M.; Peter Tkac, P.

2007-01-01

Technetium is known for its high mobility in a soil-water system in non-reducing aerobic condition and also high bio-availability for plants, because the most stable form of technetium in natural surface environment is pertechnetate which is highly soluble. The chemical form of technetium changes with environmental conditions. Concentration of technetium in the environment is very low, therefore many separation steps are needed for technetium determination. It has been developed a method for the routine determination of technetium-99 from environmental matrices and radioactive wastes using technetium-99m as an internal yield monitor. Technetium-99 is extracted from the soil samples with nitric acid. Many contaminants are co-precipitated with ferric hydroxide and technetium in the supernatant is pre-concentrated and further purified using anion exchange chromatography. Final separation of technetium was achieved by extraction with tetraphenylarsonium chloride in chloroform from sulphuric acid or pure water. The chemical yield is determined through the measurement of technetium-99m by scintillation counting system and the technetium-99 activity is measured using proportional counter after decay of the technetium-99m activity. Typical recoveries for this method are in the order 50-60 % (authors)

Study of sorption of technetium on pyrrhotine

International Nuclear Information System (INIS)

Shen Dong; Fan Xianhua; Su Xiguang; Zeng Jishu

2001-01-01

The sorption behaviors of technetium on pyrrhotine are studied with batch experiment and dilute sulfuric acid is used to dissolve the technetium adsorbed on pyrrhotine. Sorption and desorption experiment are performed under aerobic and anaerobic conditions (inert gas box). The results show that a significant sorption of technetium on pyrrhotine is found under aerobic and anaerobic conditions, and the sorption on the mineral is supposed to be due to the reduction of TcO 4 - to insoluble TcO 2 ·nH 2 O. Desorption process of the sorbed technetium into dilute sulfuric acid is found to be different under aerobic and anaerobic conditions. On addition of H 2 O 2 to the leach solution a sudden increase of the technetium concentration is observed

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

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.

Technetium recovery from high alkaline solution

Energy Technology Data Exchange (ETDEWEB)

Nash, Charles A.

2016-07-12

Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

Sorption of radioactive technetium on pyrrhotine

International Nuclear Information System (INIS)

Shen, D.; Fan, X.H.; Su, X.G.; Zeng, J.S.; Dong, Y.

2002-01-01

The sorption behavior of technetium on pyrrhotine was studied with batch experiments and diluted sulfuric acid (less than 2.88 mol/l) was used to dissolve the technetium adsorbed on pyrrhotine. A significant sorption of technetium on pyrrhotine was observed under aerobic and anaerobic conditions, and the sorption on the mineral was supposed to be due to the reduction of TcO 4 - to insoluble TcO 2 x nH 2 O. Sorbed technetium on the mineral could be desorbed by diluted sulfuric acid. The maximum desorption ratio under aerobic conditions was much higher than that of under anaerobic conditions, meanwhile, the desorption rates under anaerobic conditions were higher than that of under aerobic conditions in the initial stage of the experiments. (author)

Barium iodide and strontium iodide crystals andd scintillators implementing the same

Science.gov (United States)

Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

2013-11-12

In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

Method of producing radioactive technetium-99M

International Nuclear Information System (INIS)

Karageozian, H.L.

1979-01-01

A chromatographic process of producing high purity and high yield radioactive Technetium-99m. A solution containing Molybdenum-99m and Technetium-99m is placed on a chromatographic column and eluted with a neutral solvent system comprising an organic solvent and from about 0.1 to less than about 10% of water or from about 1 to less than about 70% of a solvent selected from the group consisting of aliphatic alcohols having 1 to 6 carbon atoms. The eluted solvent system containing the Technetium-99m is then removed leaving the Technetium-99m as a dry, particulate residue

Technetium in the geologic environment - a literature survey

International Nuclear Information System (INIS)

Torstenfelt, B.; Allard, B.; Andersson, K.; Olofsson, U.

1981-07-01

The authors present a literature survey of technetium, discussing, in particular, the oxidation states, the chemistry of technetium in connection with spent nuclear fuel storage, the sorption of technetium in rock, clay, soil and sea bottom sediments. (G.T.H.)

Chemistry and structure of technetium complexes

International Nuclear Information System (INIS)

Baldas, J.; Boas, J.F.; Bonnyman, J.; Williams, G.A.

1983-01-01

The structures of tris(2-aminobenzenethiolato) technetium(VI) and dichlorobis(diethyldithiocarbamato) thionitrosyltechnetium(V) have been determined by single crystal x-ray diffraction analysis. The preparation and chemistry of thiocyanato complexes of technetium have been investigated

X-ray electron investigation of technetium compounds

International Nuclear Information System (INIS)

Gerasimov, V.N.; Kryuchkov, S.V.; Kuzina, A.F.; Kulakov, V.M.; Pirozhkov, S.V.; Spitsyn, V.I.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)

1982-01-01

Investigation results of a number of technetium compounds using the method of X-ray electron spectroscopy have been presented for the first time. Calculation of effective charge for compounds without Tc-Tc bond and cluster complexes with strong Tc-Tc bond is made. Strong interdependence of effective charge and properties of technetium clusters is shown. Binding energies for certain cluster complexes of technetium with halides are given

Environmental behavior of technetium-99

International Nuclear Information System (INIS)

Turcotte, M.D.S.

1982-12-01

This report presents a review of the literature on technetium-99. The chemical and physical properties of some technetium compounds are considered, and a discussion of possible source terms is included. Literature on the environmental behavior of technetium is presented, including its behavior in the bodies of animals and humans. The primary sources of Tc-99 in the environment are fallout from atomic detonations and releases from nuclear fuel reprocessing plants. The environmental behavior of technetium-99 has been studied predominantly with respect to movement in soil and accumulation in plants. There is a surprising scarcity of data on behavior of Tc-99 in the atmosphere and in aquatic systems. Additional work needs to be conducted in these two areas to determine behavior and to acquire baseline concentration data. Much of the soil work has produced contradictory results. In-depth studies of holdup mechanisms for Tc-99 in both geological repositories and soil need to be conducted. Since plants represent a potential bioaccumulation of Tc-99, plant uptake studies of Tc-99 under field conditions also need to be done

Technetium behaviour under deep geological conditions

International Nuclear Information System (INIS)

Kumata, M.; Vandergraaf, T.T.

1993-01-01

The migration behaviour of technetium under deep geological conditions was investigated by performing column tests using groundwater and altered granitic rock sampled from a fracture zone in a granitic pluton at a depth of about 250 m. The experiment was performed under a pressure of about 0.7 MPa in a controlled atmosphere glove box at the 240 m level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. The technetium was strongly sorbed on the dark mafic minerals in the column. With the exception of a very small unretarded fraction that was eluted with the tritiated water, no further breakthrough of technetium was observed. This strong sorption of technetium on the mineral surface was caused by reduction of Tc(VII), probably to Tc(IV) even though the groundwater was only mildly reducing. (author) 5 figs., 4 tabs., 15 refs

Technetium migration in natural clays

International Nuclear Information System (INIS)

Luebke, Maria

2015-01-01

The present work was performed within the joint research project ''Retention of repository relevant radionuclides in argillaceous rocks and saline systems'' (contract no.: 02E10981), funded by the Federal Ministry for Economic Affairs and Energy (BMWi). The aim was to obtain first insights into the interaction of the long-lived fission product technetium and natural clay with regard to a repository for high-level nuclear waste. For this purpose Opalinus Clay from Mont Terri (northern Switzerland) was used as a reference material. The nuclide technetium-99 will contribute to the radiotoxicity of spent nuclear fuel for more than thousand years due to its long half-live. In case of a leakage of the storage vessels, the geochemistry of technetium is determined by its oxidation state, at which only the oxidation states +IV and +VII are relevant. Because of the high solubility and low affinity to sorption on surfaces of minerals, Tc(VII) is considered to be very mobile and thus the most hazardous species. The focuses of this study therefore are diffusion experiments with this mobile species and investigations of the effect of ferrous iron on the mobility and speciation of technetium.rnThe interaction of technetium and Opalinus Clay was studied in sorption and diffusion experiments varying several parameters (pH value, addition of reducing agents, effect of oxygen, diffusion pathways). In the course of this study spatially resolved investigations of the speciation have been performed on Opalinus Clay thin sections and bore cores for the first time. In addition to the speciation, further information regarding elemental distributions and crystalline phases near technetium enrichments were obtained. Supplementary investigations of powder samples allowed determining the molecular structure of technetium on the clay surface.rnBoth the combination of sorption experiments with spectroscopic investigations and the diffusion experiment exhibit a reduction of Tc

Iodide transport and breast cancer.

Science.gov (United States)

Poole, Vikki L; McCabe, Christopher J

2015-10-01

Breast cancer is the second most common cancer worldwide and the leading cause of cancer death in women, with incidence rates that continue to rise. The heterogeneity of the disease makes breast cancer exceptionally difficult to treat, particularly for those patients with triple-negative disease. To address the therapeutic complexity of these tumours, new strategies for diagnosis and treatment are urgently required. The ability of lactating and malignant breast cells to uptake and transport iodide has led to the hypothesis that radioiodide therapy could be a potentially viable treatment for many breast cancer patients. Understanding how iodide is transported, and the factors regulating the expression and function of the proteins responsible for iodide transport, is critical for translating this hypothesis into reality. This review covers the three known iodide transporters - the sodium iodide symporter, pendrin and the sodium-coupled monocarboxylate transporter - and their role in iodide transport in breast cells, along with efforts to manipulate them to increase the potential for radioiodide therapy as a treatment for breast cancer. © 2015 Society for Endocrinology.

Complex crystals formed in the aqueous solution of copper(I) iodide and sodium iodide

International Nuclear Information System (INIS)

Sugasaka, Kazuhiko; Fujii, Ayako

1977-01-01

Crystals of different crystal habits were separated from the copper(I) iodide and sodium iodide solution and the thermal changes of the composition of copper(I) iodide and sodium iodide complexes were studied by chemical analysis, thermal analysis and X-ray diffractometry. Granular and columnar crystals were determined to be copper(I) iodide and sodium iodide dihydrate by X-ray diffraction analysis, respectively. Needle crystal (A) which was separated from the solution at 25 0 C was assumed to be Na 2 CuI 3 .6H 2 O. (A) was stable in its appearance in the air, but the X-ray diffraction pattern of (A) changed. Needle crystal (B) which was recrystallized at 10 0 C from mother liquor after the separation of crystal (A) was assumed to be NaCuI 2 .4H 2 O. (B) was hygroscopic and decomposed to precipitate copper(I) iodide with moisture in the air. (A) and (B) were found to change by heating and or drying, respectively, as follows: Na 2 CuI 3 .6H 2 O → (-2H 2 O, 80 0 C) → 2NaI.2H 2 O + CuI → (-4H 2 O, 160 0 C) → 2NaI + CuI → (+1/2O 2 , 450 0 C) → 2NaI + CuO + 1/2I 2 , NaCuI 2 .4H 2 O → (-4H 2 O, Dried) → NaI + CuI. (auth.)

Technetium discharges into the environment

International Nuclear Information System (INIS)

Luykx, F.

1986-01-01

Technetium-99 is the most important technetium isotope released to the environment because of its long life and its relatively high fission yield. Its release to date, mainly as a result of nuclear fuel reprocessing, is estimated to be of the order of 1000 TBq. The quantity from nuclear weapons testing would only be some 10-15% of this value. (author)

The regulation of technetium-99 discharges at Sellafield

International Nuclear Information System (INIS)

Mayall, A.

2002-01-01

The reprocessing of spent Magnox fuel at BNFL Sellafield produces a liquid waste concentrate containing technetium-99 and other, more radiotoxic, radionuclides such as plutonium and americium. The concentrate is known as medium active concentrate (MAC). Prior to 1981, MAC was discharged to sea untreated after several years' storage, during which short-lived radionuclides underwent radioactive decay. In the early 1980s, discharges of MAC were suspended and it was retained in storage tanks, pending the construction of a plant to remove the radionuclides of greatest radiological concern (these did not include technetium- 99). The Enhanced Actinide Removal Plant started operation in 1994 and began to clear the backlog of stored waste MAC, as well as current arisings from Magnox reprocessing. As a consequence technetium-99 was once more discharged to sea. Subsequently, concentrations of this radionuclide in the marine environment increased. In particular, there was a significant increase in the concentration of technetium-99 in lobster in the Irish Sea. An increase in technetium-99 has also been detected at locations far distant from Sellafield, e.g. in Scandinavian coastal waters, albeit at very low concentrations. This dispersal of technetium- 99 throughout the Irish Sea and further afield has therefore caused concern, although the radiological impact is low. This paper examines the nature and source of the technetium-99 in sea discharges at Sellafield and the levels of past and current discharges as well as their impact. It goes on to describe the Environment Agency's recent proposals on the future regulation of technetium-99 discharges and how these should lead to substantial reductions in not only technetium-99 discharges, but also of other radionuclides such as caesium-137 and strontium-90. (author)

Chemistry of technetium in the environment

International Nuclear Information System (INIS)

McFadden, K.M.

1980-08-01

Technetium release to the environment may occur during separation and recovery of spent nuclear fuels, or in disposal of aqueous waste from nuclear facilities, hospitals, or other users. The chemistry and sources of technetium are reviewed as a basis for prediction of its behavior in the environment

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)

Production of Molecular Iodine and Tri-iodide in the Frozen Solution of Iodide: Implication for Polar Atmosphere.

Science.gov (United States)

Kim, Kitae; Yabushita, Akihiro; Okumura, Masanori; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Blaszczak-Boxe, Christopher S; Min, Dae Wi; Yoon, Ho-Il; Choi, Wonyong

2016-02-02

The chemistry of reactive halogens in the polar atmosphere plays important roles in ozone and mercury depletion events, oxidizing capacity, and dimethylsulfide oxidation to form cloud-condensation nuclei. Among halogen species, the sources and emission mechanisms of inorganic iodine compounds in the polar boundary layer remain unknown. Here, we demonstrate that the production of tri-iodide (I3(-)) via iodide oxidation, which is negligible in aqueous solution, is significantly accelerated in frozen solution, both in the presence and the absence of solar irradiation. Field experiments carried out in the Antarctic region (King George Island, 62°13'S, 58°47'W) also showed that the generation of tri-iodide via solar photo-oxidation was enhanced when iodide was added to various ice media. The emission of gaseous I2 from the irradiated frozen solution of iodide to the gas phase was detected by using cavity ring-down spectroscopy, which was observed both in the frozen state at 253 K and after thawing the ice at 298 K. The accelerated (photo-)oxidation of iodide and the subsequent formation of tri-iodide and I2 in ice appear to be related with the freeze concentration of iodide and dissolved O2 trapped in the ice crystal grain boundaries. We propose that an accelerated abiotic transformation of iodide to gaseous I2 in ice media provides a previously unrecognized formation pathway of active iodine species in the polar atmosphere.

Final Report, Research Program to Investigate the Fundamental Chemistry of Technetium

International Nuclear Information System (INIS)

Lukens, Wayne W. Jr.; Fickes, Michael J.; Bucher, Jerome J.; Burns, Carol J.; Edelstein, Norman M.; Shuh, David K.

2000-01-01

The purpose is to increase the basic scientific understanding of technetium chemistry to better understand the behavior of technetium in chemical environments relevant to DOE. Two important areas in need of study are the behavior of technetium in highly alkaline solutions similar to high-level nuclear waste, and its behavior in different waste forms. This research program addressed these two needs. Two separate approaches were used in this program. The first focus was to understand the basic solution chemistry of technetium, which underlies its behavior in the highly alkaline environment of the nuclear waste tanks located at the Savannah River and Hanford Sites. The specific problems at these sites are related to the anomalous oxidation state of technetium (Schroeder 1995). Although, at high pH, technetium should exist in its highest oxidation state as TcO 4 - , soluble, lower-valent technetium species have been observed in certain wastes. The specific unknowns that this program sought to answer are the nature of lower valent technetium species that can be formed in highly alkaline solution and whether pertechnetate undergoes radiolytic reduction in highly alkaline solution when nitrate is present in excess. The second focus area is the behavior of technetium immobilized in various waste forms. The behavior of technetium in cement wastes was examined to gain information about its long-term stability. Specifically, this research examined the oxidation of reduced technetium species by components present in high-level waste that are incorporated into cement waste along with technetium

The performance of gel technetium-99m generator

International Nuclear Information System (INIS)

Liu Yishu

2004-01-01

Technetium-99m, as one of the important radionuclides in nuclear medical science, has been widely used for diseases diagnosis in both developed and developing countries for many years. Technetium-99m can be obtained from both fission-type and gel-type Tc-99m generator. Fission-type generator was prepared by Molybdenum-99 separated from fission products of uranium-235 and gel-type was prepared by irradiating nature MoO 3 in reactor, and a series of chemical and physical processes. This paper briefly describes the manufacturing technical process of gel-type Technetium-99 generator, including the preparation of target containing nature MoO 3 , the target irradiation in reactor, gel preparation, gel filtration and drying, dried gel cracking, generator loading and activity calibration of generator. The performances of gel-type Technetium-99m generator, such as elution efficiency, elution profile, the pH, Mo breakthrough, Zirconium content, radiochemical purity, radionuclidic purity, sterility and pyrogencity of eluate, are also expatiated in detail. Comparing with fission-type Technetium-99m generator, the defects of gel-type Technetium-99m generator are enumerated and their overcoming solutions are recommended in this paper. (author)

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).

Sources and behavior of technetium in the environment

International Nuclear Information System (INIS)

Schulte, E.H.; Scoppa, P.

1987-01-01

Technetium is a man-made element produced in increasing amounts during the last decades. The chemical and physical properties of some technetium compounds are considered, and a discussion of possible source terms is included. Literature on the environmental behavior of technetium is reviewed to evaluate its transfer and equilibrium distribution in aquatic and terrestrial ecosystems. Considerable effort has been expended in the last years in order to understand the biogeochemical processes responsible for the long-term behavior of technetium in the environment and its transfer through food chains as well as to identify critical pathways of the long-lived radioisotope Tc-99 from the environment to man. (Auth.)

Final Report, Research Program to Investigate the Fundamental Chemistry of Technetium

Energy Technology Data Exchange (ETDEWEB)

Lukens Jr., Wayne W.; Fickes, Michael J.; Bucher, Jerome J.; Burns, Carol J.; Edelstein, Norman M.; Shuh, David K.

2000-12-23

The purpose is to increase the basic scientific understanding of technetium chemistry to better understand the behavior of technetium in chemical environments relevant to DOE. Two important areas in need of study are the behavior of technetium in highly alkaline solutions similar to high-level nuclear waste, and its behavior in different waste forms. This research program addressed these two needs. Two separate approaches were used in this program. The first focus was to understand the basic solution chemistry of technetium, which underlies its behavior in the highly alkaline environment of the nuclear waste tanks located at the Savannah River and Hanford Sites. The specific problems at these sites are related to the anomalous oxidation state of technetium (Schroeder 1995). Although, at high pH, technetium should exist in its highest oxidation state as TcO{sub 4}{sup {minus}}, soluble, lower-valent technetium species have been observed in certain wastes. The specific unknowns that this program sought to answer are the nature of lower valent technetium species that can be formed in highly alkaline solution and whether pertechnetate undergoes radiolytic reduction in highly alkaline solution when nitrate is present in excess. The second focus area is the behavior of technetium immobilized in various waste forms. The behavior of technetium in cement wastes was examined to gain information about its long-term stability. Specifically, this research examined the oxidation of reduced technetium species by components present in high-level waste that are incorporated into cement waste along with technetium.

Iodide uptake by negatively charged clay interlayers?

International Nuclear Information System (INIS)

Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

2015-01-01

Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI (aq) ) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. - Highlights: • Iodide sorption experiments were completed with a diverse array of clay minerals. • Iodide uptake trended with CEC and swamping electrolyte identity and concentration. • Results can be explained by considering the formation of ion pairs in clay interlayers

Corrosion and antifouling characteristics of technetium 99 in seawater

International Nuclear Information System (INIS)

Spitsyn, V.I.; Strekalov, P.V.; Balakhovskij, O.A.; Mikhajlovskij, Yu.N.

1982-01-01

The results are presented of studying the corrosive and antifouling properties of metallic technetium-99 in the Barents Sea and the Sea of Japan. Foil of 99 Tc glued on acrylic plastic served as a sample. High corrosion resistance and antifouling properties exhibited by 99 Tc in seawater point to favorable prospects of further studies aimed at development of new methods for protection against corrosion and fouling of metallic structures and parts with the use of technetium. The antifouling properties of technetium would evidently be used most efficiently when coating materials of high corrosion resistance to seawater (titanium, stainless steels, special alloys, etc.) with layers of technetium. The use of technetium for coating low-alloyed or carbon steels employed in seawater is yet problematic

Research Program to Investigate the Fundamental Chemistry of Technetium

International Nuclear Information System (INIS)

Edelstein, Norman M.; Burns, Carol J.; Shuh, David D.; Lukens, Wayne

2000-01-01

Technetium (99Tc, half-life = 2.13x105 years, b-emitter) is one of the radionuclides of major concern for nuclear waste disposal. This concern is due to the long half-life of 99Tc, the ease with which pertechnetate, TcO4 -, migrates in the geosphere, and the corresponding regulatory considerations. The problem of mobility of pertechnetate in the environment is compounded by the fact that pertechnetate is the thermodynamically stable form of technetium in aerobic environments. These two factors present challenges for the safe, long term immobilization of technetium in waste forms. Because of the stability of pertechnetate, technetium has been assumed to exist as pertechnetate in the aqueous phase of nuclear waste tanks. However, recent studies indicate that a significant fraction of the technetium is in a different chemical form. This program addresses the fundamental solution chemistry of technetium in the waste tank environment, and in a second part, the stability of technetium in various waste forms. The chemistry of this element will be studied in aqueous solutions at high pH, with various added salts such as nitrate, nitrite, and organic complexants, and as a function of radiation dose, to determine whether radiolysis effects can reduce TcO4 -. A separate facet of this research is the search for chemical forms of technetium that may be thermodynamically and/or kinetically stable and may be incorporated in various waste forms for long term storage. This phase of the program will address the problem of the possible oxidation of lower valent technetium species in various waste form matrices and the subsequent leaching of the highly soluble TcO4 -

Technetium-aspirin molecule complexes

International Nuclear Information System (INIS)

El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M.

1993-01-01

Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

Measurement and behaviour of technetium in fast reactor fuel reprocessing

International Nuclear Information System (INIS)

Ferguson, C.; Kyffin, T.W.

1986-02-01

A method is described for the spectrophotometric measurement of technetium in plant solutions from the reprocessing of fast reactor fuel. The technetium is selectively extracted using tri-iso-octylamine. After back extraction, thiocyanate is added, in the presence of tetrabutyl-ammonium hydroxide, to form the red hexa-thiocyanato anionic complex in a chloroform medium. The concentration of the technetium is then calculated from the spectrophotometric measurement of this complex. This method was applied to bulk samples, collected during a PFR fuel reprocessing campaign, to identify the main routes followed by technetium through the reprocessing plant. In order to understand the probable behaviour of technetium in the process plant streams, an investigation into the influence of plutonium IV nitrate on the extraction of Tc (VII) into 20%v/v tributyl phosphate/odourless kerosene solution from nitric acid solutions, was initiated. The results of this investigation, along with the known distribution coefficient for the extraction of the uranyl/technetium complex U0 2 (N0 3 )(Tc0 4 ).2TBP and the redox chemistry of technetium, are used to predict the probable behaviour of technetium in the process plant streams. This predicted behaviour is compared with the experimental results and reasonable agreement is obtained between experiment and theory, considering the history of the samples analysed. (author)

Study of the synthesis of ammonia over technetium catalysts

International Nuclear Information System (INIS)

Spetsyn, V.I.; Mikhailenko, I.E.; Pokrovskaya, O.V.

1982-01-01

The catalytic properties of technetium in the synthesis of ammonia have been studied in the present work. Technetium catalysts according to specific yield surpass all know catalysts for the synthesis of ammonia. The enhanced catalytic activity of technetium compared to manganese and rhenium is apparently explained by the presence of the radioactivity of 99 Tc. The processes of adsorption, orientation of the adsorbed molecules, and their binding energies can differ during radiation action. Irradiation of the carrier, occurring through #betta#-emission of 99 Tc, with doses of 4-8 x 10 3 rad/day, increased the number of defects in the crystal structure where stabilization of technetium atoms was possible. The existence of charged centers can cause an increase in the dissociative chemisorption of nitrogen, which is the limiting stage of the process. Technetium catalysts possess a stable catalytic activity and do not require its restoration for several months. Results suggest that the use of technetium as a catalyst for the synthesis of ammonia has real advantages and potential possibilities

Iodide uptake by negatively charged clay interlayers?

Science.gov (United States)

Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

2015-09-01

Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study of the chemical behaviour of technetium during irradiated fuels reprocessing

International Nuclear Information System (INIS)

Zelverte, A.

1988-04-01

This paper deals with the preparation of the lower oxidation states +III +IV and +V of technetium in nitric acid and its behaviour during the reprocessing of nuclear fuels (PUREX process). The first part of this work is a bibliographical study of this element in solution without any strong ligand. By chemical and electrochemical technics, pentavalent, tetravalent and trivalent technetium species, were prepared in nitric acid. The following chemical reactions are studied: - trivalent and tetravalent technetium oxidation by nitrate ion. - hydrazine and tetravalent uranium oxidation catalysed by technetium: in those reactions, we point out unequivocally the prominent part of trivalent and tetravalent technetium, - technetium behaviour towards hydroxylamine. Technetium should not cause any disturbance in the steps where hydroxylamine is employed to destroy nitrous acid and hydrazine replacement by hydroxylamine in uranium-plutonium partition could contribute to a best reprocessing of nuclear fuels [fr

The chemical speciation of technetium in the environment: a literature survey

International Nuclear Information System (INIS)

Sparkes, S.T.; Long, S.E.

1987-07-01

This report reviews the current understanding of the chemical forms and behaviour of technetium in the environment. Technetium (VII) is the dominant species in most systems, however when reducing conditions arise technetium (IV) species predominate. Pertechnetate is a highly mobile ion in aqueous media and can exhibit significant environmental transfer. Technetium (IV) is readily sorbed by sediments and is able to complex with various ligands which subsequently determine its fate. Complexation with high molecular weight organic moieties reduces the availability of technetium although this is not necessarily the case with smaller molecules. In plants, technetium is absorbed as TcO 4 - and can become incorporated into organic molecules. The technetium present in such forms is generally considered less available for uptake by the ingesting animal than aqueous TcO 4 - , although significant transfer of this element has been reported from food into eggs. Areas of potential future interest are suggested. (author)

Supplemental Report: Application of Emission Spectroscopy to Monitoring Technetium

International Nuclear Information System (INIS)

Spencer, W.A.

2000-01-01

This report provides supplemental information to an earlier report BNF-98-003-0199, ''Evaluation of Emission Spectroscopy for the On-Line Analysis of Technetium''. In this report data is included from real Hanford samples as well as for solutions spiked with technetium. This supplemental work confirms the ability of ICP-ES to monitor technetium as it breaks through an ion exchange process

Synthesis and characterization of volatile technetium compound

International Nuclear Information System (INIS)

Childs, Bradley C.; Poineau, Frederic; Czerwinski, Ken R.

2013-01-01

Technetium-99 is an important fission (T 1/2 = 2.13.105 y) product of the nuclear industry. Technetium in its highest oxidation state (VII) is highly mobile and can represent a threat to the environment. There are over 55 million gallons of high level mixed waste located at the Hanford site. Waste tanks at the Hanford site contain Tc that could potentially leak, and in the context of management of technetium, a glass waste form was proposed to counteract the issue. In the process of synthesizing melt glass between the temperatures of 600°C and 1100°C, volatile technetium compounds were observed in the reaction tube. These compounds displayed characteristic colors based upon the reaction environments of either breathing air or nitrogen gas. A breathing air atmosphere produces a red compound that adheres to the walls of the reaction tube. An atmosphere of nitrogen gas produces a white compound that was observed on the walls of the reaction tube. (author)

Concentration of technetium by marine organisms

International Nuclear Information System (INIS)

Koyanagi, T.; Suzuki, Y.; Nakamura, R.; Nakahara, M.

1990-01-01

Accumulation and excretion of technetium by marine organisms were observed in radioisotope tracer experiments to determine concentration factors for estimating radiation dose to humans from radioactive pollution of marine environments. Marine fish, crustaceans, mollusks, echinoderms, and seaweeds were reared in sea water labeled with 95m Tc to observe uptake from sea water. The organisms were then transferred into unlabeled sea water for depuration experiments. Concentration factors were calculated from uptake and excretion rates. Also considered was the contribution of food-chain transfer of technetium, observed by administering labeled seaweeds to mollusks or echinoderms. Low accumulations were shown by fish, crustaceans, pelecypods and cephalopods, whereas high concentration factors were observed in gastropods and seaweeds. Species specificity or specific accumulation in special organs or tissues was not evident except in seaweed, where the difference was clearly species-associated. Relatively high rates of technetium retention were observed in the organisms administered labeled seaweed. The higher concentrations observed in gastropods, compared to those in pelecypods, were thought to result from different feed habits. The adaptability of some species as indicator organisms for monitoring 99 Tc in sea water was recognized, but the contribution of technetium to radiation dose was considered insignificant

Transfer of technetium from soil to paddy and upland rice

International Nuclear Information System (INIS)

Yanagisawa, Kei; Muramatsu, Yasuyuki

1995-01-01

Soil-plant transfer factors (concentration ratio between the plant and soil) of technetium in paddy and upland rice plants were obtained from laboratory experiments. The transfer factor is one of the most important parameters for environmental radiation dose assessment. Technetium tracer ( 95m TcO 4 - ) was added to the soil prior to rice cultivation. The transfer factor of technetium for the hulled grains (brown rice) of paddy rice (≤0.0002) was much lower than for that of upland rice (0.021). The transfer factors for both types of hulled grains were much lower than in the leaves. The technetium decontamination rate from hulled grains by polishing was 34%, the percentage of the weight decrease being 12%. The concentration of technetium in the soil solution collected from the paddy rice soil (flooded conditions) decreased rapidly with time due to its adsorption on the soil. In the upland rice soil (non-flooded) solution, the decrease in the technetium concentration was fairly slow. The low transfer factors for the paddy rice plants could be explained by the immobilization of technetium in the flooded soil. The oxidation-reduction potentials (Eh) in the flooded soil decreased rapidly with time. We conclude that technetium tracer added as TcO 4 - to flooded soil is readily transformed to an insoluble form (e.g.TcO 2 ) under the reducing conditions provided by flooding. (author)

Technetium complexation by macrocyclic compounds

International Nuclear Information System (INIS)

Li Fan Yu.

1983-01-01

Research in nuclear medicine are directed towards the labelling of biological molecules, however, sup(99m)Tc does not show sufficient affinity for these molecules. The aim of this study was to evaluate the ability of macrocyclic compounds to bind strongly technetium in order to be used as complexation intermediate. The reducing agents used were a stannous complex and sodium dithionite. Cryptates and polyesters are not good complexing agents. They form two complexes: a 2:1 sandwich complex or 3:2 and a 1:1 complex. Cyclams are good complexing agents for technetium their complexations strength was determined by competition with pyrophosphate, gluconate and DTPA. Using the method of ligand exchange, the oxidation state of technetium in the Tc-cyclam complex was IV or V. They are 1:1 cationic complexes, the complex charge is +1. The biodistribution in rats of labelling solutions containing (cyclam 14 ane N 4 ) C 12 H 25 shows a good urinary excretion without intoxication risks [fr

Process for producing radioactive technetium 99 m

International Nuclear Information System (INIS)

Karageozian, H.L.

1979-01-01

Active aluminium oxide containing Molybdenum 99 and technetium 99 m is treated with a neutral solvent consisting of water, methylethylketone and ethanol. Technetium 99 m remains on the chromatographic material after drying, in the form of a dry powder. Other aliphatic alcohols can also be utilised. (DG) [de

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.

Electrochemical reaction rates in a dye-sensitised solar cell - the iodide/tri-iodide redox system

DEFF Research Database (Denmark)

Bay, L.; West, K.; Winther-Jensen, B.

2006-01-01

The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide....../tri-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI)-all deposited onto fluorine-doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrodes in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

Electrochemical reaction rates in a dye sentisised solar cell - the iodide/tri-iodide redox system

DEFF Research Database (Denmark)

Bay, Lasse; West, Keld; Winter-Jensen, Bjørn

2006-01-01

The electrochemical reaction rate of the redox couple iodide / tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide / tri......-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI) - all deposited onto fluorine doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrode in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

Research program to investigate the fundamental chemistry of technetium

International Nuclear Information System (INIS)

Shuh, David K.; Lukens, Wayne W.; Burns, Carol J.

2003-01-01

The objective of this research is to increase the knowledge of the fundamental technetium chemistry that is necessary to address challenges to the safe, long-term remediation of high-level waste posed by this element. These challenges may be divided into two categories: unexpected behavior of technetium in high-level waste tanks at the Hanford and Savannah River Sites and the behavior of technetium in waste forms

Research program to investigate the fundamental chemistry of technetium

Energy Technology Data Exchange (ETDEWEB)

Shuh, David K.; Lukens, Wayne W.; Burns, Carol J.

2003-12-19

The objective of this research is to increase the knowledge of the fundamental technetium chemistry that is necessary to address challenges to the safe, long-term remediation of high-level waste posed by this element. These challenges may be divided into two categories: unexpected behavior of technetium in high-level waste tanks at the Hanford and Savannah River Sites and the behavior of technetium in waste forms.

A method for the determination of technetium in environmental waters

International Nuclear Information System (INIS)

Robb, P.; Warwick, P.; Malcolme-Lawes, D.J.

1985-01-01

A method is described which can be used to determine technetium-99 levels in a range of water types. Ruthenium isotopes which may interfere in the analysis are removed from the sample by precipitation before concentration of pertechnetate onto an ion-exchange column. Other nuclides can be removed from the column using NaOH before elution of the technetium using NaSCN. The technetium in the NaSNC eluent can then be extracted into butan-2-one which can be evaporated onto a planchette. Technetium-99m is used as a yield tracer and after this has decayed away to negligible levels. The amount of technetium on the planchette can be determined by measuring the rate of beta radiation emission from the final concentrate. (author)

Control of technetium at the Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Saraceno, A.J.

1981-01-01

Technetium-99 entered the gaseous diffusion complex as a volatile impurity in recycled uranium that was fed to the Paducah Gaseous Diffusion Plant. Subsequently, it entered the Oak Ridge and Portsmouth cascades as an impurity in Paducah product feed. Most of the technetium was adsorbed on cascade equipment in increasingly high concentrations as it moved up the cascade. Since the low energy beta radiation produced by technetium cannot penetrate cascade equipment, it presents no significant hazard to workers as long as it remains inside of equipment. However, when equipment that contains high concentrations of technetium is opened for maintenance or change-out, precautions are taken to ensure worker safety. Traps containing activated alumina are used at the plant vent streams to limit radioactive emissions as far as possible. Annual vent stream emissions have been well below DOE limits. To allow continued compliance, other potential trapping agents have been tested. Several that limit emissions more effectively than activated alumina have been found. Other traps containing magnesium fluoride are used in the upper cascade to reduce the technetium concentration. Waste solutions from decontamination can also contain technetium. These solutions must either be stored for controlled discharge or treated to remove the technetium. To allow the latter, an ion exchange facility is being installed for operation by the end of FY-1982. Liquid discharges at Portsmouth have usually been less than 5% of the DOE imposed limits

Some aspects of the assay of technetium in environmental waters

International Nuclear Information System (INIS)

Robb, P.

1983-09-01

Technetium, as 99 Tc, was rapidly concentrated from large sample volumes (> 500 cm 3 ) by use of an anion exchange column after removal of ruthenium isotopes by precipitation. The bulk of the technetium can be removed from the resin by elution with sodium thiocyanate followed by further concentration by extraction with butan-2-one. Evaporation of solvent onto a planchette followed by measurement of emitted beta radiation can determine technetium levels. Method is capable of removing between 10 -15 and 10 -6 g of technetium from 500 cm 3 of water. (author)

Fluorido complexes of technetium

International Nuclear Information System (INIS)

Mariappan Balasekaran, Samundeeswari

2013-01-01

Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The complex was isolated as alkali metal salts, and spectroscopic as well as structural features of the complexes are presented. Different salts of the trans

Enhanced iodide sequestration by 3-biphenyl-5,6-dihydroimidazo 2,1-b thiazole in sodium/iodide sym-porter (NIS)-expressing cells

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Ambroise, Y.

2008-01-01

The ability of the sodium/iodide sym-porter (NIS) to take up iodide has long provided the basis for cyto-reductive gene therapy and cancer treatment with radio-iodide. One of the major limitations of this approach is that radio-iodide retention in NIS-expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS-HEK293) and in the rat thyroid-derived cell line FRTL-5. In the presence of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b)thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5-fold. Our experiments indicate that the imidazo-thiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer. (authors)

Analysis for iodide in groundwater by x-ray fluorescence spectrometry after collection as silver iodide on activated charcoal

International Nuclear Information System (INIS)

Howe, P.T.

1980-01-01

The report describes the determination of microgram quantities of iodide in water by X-ray fluorescence spectrometry. The iodide is concentrated by precipitation as silver iodide on activated charcoal. If a 60-mL sample is available, a concentration of 0.12 mg/L can be detected. Precision (2σ) at the 1-mg/L level is +- 0.08 mg/L. (auth)

TESTING GUIDELINES FOR TECHNETIUM-99 ADSORPTION ON ACTIVATED CARBON

International Nuclear Information System (INIS)

Byrnes, M.E.

2010-01-01

CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs) will

TESTING GUIDELINES FOR TECHNETIUM-99 ABSORPTION ON ACTIVATED CARBON

Energy Technology Data Exchange (ETDEWEB)

BYRNES ME

2010-09-08

CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs

Ion exchange removal of technetium from salt solutions

International Nuclear Information System (INIS)

Walker, D.D.

1983-01-01

Ion exchange methods for removing technetium from waste salt solutions have been investigated by the Savannah River Laboratory (SRL). These experiments have shown: Commercially available anion exchange resins show high selectivity and capacity for technetium. In column runs, 150 column volumes of salt solution were passed through an ion exchange column before 50% 99 Tc breakthrough was reached. The technetium can be eluted from the resin with nitric acid. Reducing resins (containing borohydride) work well in simple hydroxide solutions, but not in simulated salt solutions. A mercarbide resin showed a very high selectivity for Tc, but did not work well in column operation

The radiopharmaceuticals labelled with technetium-99m and the radiopharmacy; Les radiopharmaceutiques marques au technetium-99m et la radiopharmacie

Energy Technology Data Exchange (ETDEWEB)

Bodenant, V

1998-10-01

In less than fifty years, the place of nuclear medicine is become primordial. Among all the radiopharmaceuticals used in nuclear medicine, the technetium-99m is the most used because of its physico-chemical properties and its great availability with the molybdenum-99m - technetium-99m generator. Since 1992, the radiopharmaceuticals, the packages, the generators are included in the pharmaceutic monopole. They are now under the reliability of the radio-pharmacist. This thesis has for object to introduce these different radiopharmaceuticals labelled with technetium-99m and to show the primordial place of the radio-pharmacist in a service of nuclear medicine. (N.C.)

Uptake and distribution of technetium in several marine algae

International Nuclear Information System (INIS)

Bonotto, S.; Gerber, G.B.; Garten, C.T. Jr.; Vandecasteele, C.M.; Myttenaere, C.; Van Baelen, J.; Cogneau, M.; van der Ben, D.

1983-01-01

The uptake or chemical form of technetium in different marine algae (Acetabularia, Cystoseira, Fucus) has been examined and a simple model to explain the uptake of technetium in the unicellular alga, Acetabularia, has been conceptualized. At low concentrations in the external medium, Acetabularia can rapidly concentrate technetium. Concentration factors in excess of 400 can be attained after a time of about 3 weeks. At higher mass concentrations in the medium, uptake of technetium by Acetabularia becomes saturated resulting in a decreased concentration factor (approximately 10 after 4 weeks). Approximately 69% of the total radioactivity present in /sup 95m/Tc labelled Acetabularia is found in the cell cytosol. In Fucus vesiculosus, labelled with /sup 95m/Tc, a high percentage of technetium is present in soluble ionic forms while approximately 40% is bound, in this brown alga, in proteins and polysaccharides associated with cell walls. In the algal cytosol of Fucus vesiculosus, about 45% of the /sup 95m/Tc appears to be present as anionic TcO - 4 and the remainder is bound to small molecules. 8 references, 5 figures, 1 table

Methyl Iodide Decomposition at BWR Conditions

International Nuclear Information System (INIS)

Pop, Mike; Bell, Merl

2012-09-01

Based on favourable results from short-term testing of methanol addition to an operating BWR plant, AREVA has performed numerous studies in support of necessary Engineering and Plant Safety Evaluations prior to extended injection of methanol. The current paper presents data from a study intended to provide further understanding of the decomposition of methyl iodide as it affects the assessment of methyl iodide formation with the application of methanol at BWR Plants. This paper describes the results of the decomposition testing under UV-C light at laboratory conditions and its effect on the subject methyl iodide production evaluation. The study as to the formation and decomposition of methyl iodide as it is effected by methanol addition is one phase of a larger AREVA effort to provide a generic plant Safety Evaluation prior to long-term methanol injection to an operating BWR. Other testing phases have investigated the compatibility of methanol with fuel construction materials, plant structural materials, plant consumable materials (i.e. elastomers and coatings), and ion exchange resins. Methyl iodide is known to be very unstable, typically preserved with copper metal or other stabilizing materials when produced and stored. It is even more unstable when exposed to light, heat, radiation, and water. Additionally, it is known that methyl iodide will decompose radiolytically, and that this effect may be simulated using ultra-violet radiation (UV-C) [2]. In the tests described in this paper, the use of a UV-C light source provides activation energy for the formation of methyl iodide. Thus is similar to the effect expected from Cherenkov radiation present in a reactor core after shutdown. Based on the testing described in this paper, it is concluded that injection of methanol at concentrations below 2.5 ppm in BWR applications to mitigate IGSCC of internals is inconsequential to the accident conditions postulated in the FSAR as they are related to methyl iodide formation

The molybdenum-technetium solar neutrino experiment

International Nuclear Information System (INIS)

Schroeder, N.C.; Wolfsberg, K.; Rokop, D.J.

1991-01-01

The authors are attempting to measure the time-averaged 8 B solar-neutrino flux over 10 Myr by measuring 98 Tc produced through the 98 Mo( nu ,e - ) reaction in a deeply buried molybdenum deposit. This will test the prediction of periodic mixing of the Sun's core over long time intervals. To separate technetium from 10,000-ton quantities of Henderson ore, the authors have taken advantage of the commercial processing of molybdenite. Technetium, volatilized during roasting of molybdenite to MoO 3 , was scrubbed from the gas stream and collected on anion exchange columns. After sample reduction and chemical separation and purification they measured technetium, as TcO 4 - , using negative thermal ionization mass spectrometry. Measurement of 99 Tc in spiked and 98 Tc in unspiked fractions from one sample gives an apparent solar neutrino production rate of 95.8 SNU. However, roaster memory probably invalidates this result

Kinetic Isotope Effects in the Reduction of Methyl Iodide

DEFF Research Database (Denmark)

Holm, Torkil

1999-01-01

a Grignard reagent to methyl iodide, and for reduction of methyl iodide with tributyltin hydride or with gaseous hydrogen iodide. Very small KIE's were found for electron transfer to methyl iodide from magnesium in ether or from sodium in ammonia. The reason may be that these reactions are transport...

Insolubilization of technetium by microorganisms in waterlogged soils

International Nuclear Information System (INIS)

Ishii, Nobuyoshi; Tagami, Keiko

2003-01-01

In order to clarify the technetium behavior in paddy field ecosystem, insolubilization of technetium in the water covering waterlogged soils was studied. Fourteen soils collected from paddy fields (9 samples) and upland fields (5 samples) were waterlogged for 7 days. After the collection of water covering the waterlogged soils, a radio tracer 95m TcO 4 - was added to the water. After 4 days incubation of the water, the tracer was separated into four fractions: insoluble, pertechnetate, cationic, and other forms of technetium. On an average, 13% of the 95m TcO 4 - changed to insoluble forms and the maximum ratio of the insolubilization was 76%. This result shows that insolubilization of technetium can occur in the water covering the waterlogged soils. Subsequently, mechanisms of Tc insolubilization were studied using the sample that showed the maximum insolubilization of Tc among the soil samples. When microorganisms were removed from the water by filtration, insoluble forms of Tc decreased to 3.6%. In contrast, the insolubilization ratio increased to 86% by the addition of organic substrates. The insolubilization, therefore, was caused by microorganisms. Furthermore, the addition of antibiotics on bacteria resulted in 23% of the insolubilization, while the antibiotic on fungi did not affect on the insolubilization. If the insolubilization were caused by biosorption, the insolubilization ratio would not decrease for the sample added antibiotics on bacteria. Therefore, these results suggest that the insolubilization of technetium is caused by bioaccumulation of living bacteria. Because the cultures with 95m TcO 4 - were incubated under aerobic conditions, technetium-insolubilizing microorganisms would presumably be aerobic bacteria. (author)

Experimental measurements of the solubility of technetium under near-field conditions

International Nuclear Information System (INIS)

Pilkington, N.J.; Wilkins, J.D.

1988-05-01

The solubility of technetium in contact with hydrated technetium dioxide under near-field conditions has been measured experimentally. The values obtained were changed little by a change in pH or in the filtration method used. The presence of organic degradation products increased slightly the solution concentration of technetium. (author)

Technetium sorption by stibnite from natural water

International Nuclear Information System (INIS)

Peretroukhine, V.; Sergeant, C.; Deves, G.; Poulain, S.; Vesvres, M.H.; Thomas, B.; Simonoff, M.

2006-01-01

The sorption of technetium by powdered and polished mineral stibnite Sb 2 S 3 has been investigated in simulated and natural underground waters from the Meuse/Haute-Marne region (France). The sorption by powdered stibnite has been found to be complete under both aerobic and anaerobic conditions in batch experiments. The sorption rate is higher in the absence of oxygen than under aerobic condition. Increasing the temperature from 30 C to 60 C results in a rise of the sorption rate by 9.1 and 27 times under anaerobic and aerobic conditions, respectively. The observed differences in sorption kinetics in the presence and in absence of oxygen are explained by the interaction of oxygen with sulfide ion in aerobic conditions and by the reduction of technetium(VII) by iron(II) and by other impurities present in natural water and in the mineral, and by the subsequent sorption of Tc(IV) on stibnite under anaerobic conditions. The sorption on a polished mineral surface resulted in the formation of a technetium film, probably Tc 2 S 7 , with a thickness of 1-3 μg Tc/cm 2 pH 3-6 and 4-12 μg Tc/cm 2 at 9-12. The simultaneous formation of stibnite colloids with adsorbed technetium occurs at pH 9-12. The study of the technetium film on the mineral by proton induced X-ray emission analysis showed it to be at least one order of magnitude thinner on the SiO 2 impurities than on the main Sb 2 S 3 component and the iron impurities. (orig.)

Sorption characteristics of technetium on crosslinked chitosan from aqueous solution

International Nuclear Information System (INIS)

Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

2014-01-01

Sorption of technetium on crosslinked chitosan was studied using batch techniques in static arrangement of experiment under aerobic conditions at laboratory temperature. The adsorption of technetium was rapid and the percentage of the technetium sorption was > 98 %. In the pH range of 3-11 adsorption of technetium on crosslinked chitosan was > 98 %. The competition effect of Fe 3+ towards TcO 4 - sorption on crosslinked chitosan was stronger than the competition effect of other observed cations. The selectivity of crosslinked chitosan for these cations in solution with the concentration above 1·10 -3 mol·dm -3 was in the order Fe 3+ > Ca 2+ > Na + > Fe 2+ . The competition effect of (ClO 4 ) - towards TcO 4 - sorption was stronger than the competition effect of (SO 4 ) 2 - ions. From these results it can be expected that crosslinked chitosan could be a suitable sorbent for the immobilization of technetium in the liquid radioactive waste. (authors)

Assessment of Technetium in the Savannah River Site Environment

International Nuclear Information System (INIS)

Carlton, W.H.; Denham, M.; Evans, A.G.

1993-07-01

Assessment of Technetium in the Savannah River Site Environment is the last in a series of eight documents on individual radioisotopes released to the environment as a result of SRS operations. The earlier documents describe the environmental consequences of tritium cesium, iodine, uranium plutonium, strontium, and carbon. Technetium transport and metabolism have been studied by the nuclear industry because it is a fission product of uranium, and by the medical community because 99m Tc commonly is used as a diagnostic imaging agent in nuclear medicine. Technetium has been produced at SRS during the operation of five production reactors. The only isotope with environmental significance is 99 Tc. Because of the small activities of 99 Tc relative to other fission products, such as 90 Sr and 137 Cs, no measurements were made of releases to either the atmosphere or surface waters. Dose calculations were made in this document using conservative estimates of atmospheric releases and from a few measurements of 99 Tc concentrations in the Savannah River. Technetium in groundwater has been found principally in the vicinity of the separation areas seepage basins. Technetium is soluble in water and follows groundwater flow with little retardation. While most groundwater samples are negative or show little technetium a few samples have levels slightly above the limits set by the EPA for drinking water. The overall radiological impact of SRS 99 Tc releases on the offsite maximally exposed individual during 38 years of operations can be characterized by maximum individual doses of 0.1 mrem (atmospheric) and 0.8 mrem (liquid), compared with a dose of 13,680 mrem from non-SRS sources during the same time period. Technetium releases have resulted in a negligible risk to the environment and the population it supports

Fluorido complexes of technetium

Energy Technology Data Exchange (ETDEWEB)

Mariappan Balasekaran, Samundeeswari

2013-07-04

Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The

Iodide adsorption on the surface of chemically pretreated clinoptilolite

International Nuclear Information System (INIS)

Chmielewska-Horvatova, E.; Lesny, J.

1995-01-01

The possibility to use the monoionic Ag +- form (eventually Hg +- and Hg 2+ -forms) of clinoptilolite of domestic origin for radioactive iodide elimination from waters has been studied. The capacity of the monoforms of clinoptilolite towards iodide exceeds many times that of the capacity of clinoptilolite in natural form. Due to the low solubility product of AgI, Hg 2 I 2 and HgI 2 iodides generate precipitates on the zeolite surface. Rtg analyses of the silver form of clinoptilolite after sorption of iodide demonstrate the formation of new crystals on the zeolite surface. The influence of interfering anions on the adsorption capacity of silver clinoptilolite towards iodide was investigated, too. Kinetic curves of iodide desorption from the surface of silver and mercury clinoptilolite were compared. Simultaneously, adsorption isotherms for the systems aqueous iodide solution/Ag-, Hg-clinoptilolite were determined. (author) 6 refs.; 7 figs.; 4 tabs

21 CFR 172.375 - Potassium iodide.

Science.gov (United States)

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be...

In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

OpenAIRE

Eleonore Haltner-Ukomadu; Svitlana Gureyeva; Oleksii Burmaka; Andriy Goy; Lutz Mueller; Grygorii Kostyuk; Victor Margitich

2018-01-01

An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility) of the antiviral compound enisamium iodide (4-(benzylcarbamoyl)-1-methylpyridinium iodide) were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp) of enisamium iodide was assessed using human colon carcinoma (Caco-2) cells at three concentrations. The solubility of enisamium iodide in ...

Nitrido-technetium(V) complexes with amino acids: Preparation and X-ray crystal structure of the L-cysteinate ethyl ester technetium(V) complex

International Nuclear Information System (INIS)

Marchi, A.; Rossi, R.; Marvelli, L.; Bertolasi, V.

1993-01-01

Technetium-99m is the radionuclide of choice in diagnostic nuclear medicine due to its ideal photon energy of 140 keV and half-life of 6 h. Neutral, stable, and lipophilic technetium complexes with diamino dithiol ligands (DADT) have been widely studied as potential brain perfusion agents and a 99m Tc complex of N,N'-1,2-ethylenediylbis(L-cysteine diethyl ester) (L,L-ECD) has been proposed as a marker of regional cerebral blood flow. It crosses the blood brain barrier (BBB) and is retained in the brain owing to enzymatic hydrolysis of one ester group yielding to a more polar species. More recently, 99m Tc-cysteine complex has been evaluated in animal distribution studies for tumor diagnosis, but its chemical structure has not been determined. A large number of transition metal complexes with amino acids and peptides have been synthesized and structurally characterized to understand their interactions with proteins and antibodies, as well as biocatalytic processes, but only a limited number of rhenium and technetium compounds have been reported. Up to now, the only technetium complex to be characterized by X-ray analysis that contains amino acids as ligand is [TcO(L,L-ECD)]. The author's interest in the nitrido-technetium chemistry is due to the discovery of a new method for preparing radiopharmaceuticals containing the [ 99m Tc triple-bond N] 2+ core. In this communication the authors report the synthesis and characterization of nitrido-technetium complexes with L-cysteine ethyl ester (CYS-OEt), L-cysteine (CYS) and cysteamine (CSA) and the first X-ray crystal structure of a [TcN] 2+ -amino acid complex

Flavonoid rutin increases thyroid iodide uptake in rats.

Directory of Open Access Journals (Sweden)

Carlos Frederico Lima Gonçalves

Full Text Available Thyroid iodide uptake through the sodium-iodide symporter (NIS is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO, the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH, and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function.

Potassium Iodide

Science.gov (United States)

... certain other liquids including low-fat white or chocolate milk, flat soda, orange juice, raspberry syrup, or ... Potassium iodide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: swollen glands metallic taste in the ...

Technetium-99m labeled radiodiagnostic agents and method of preparation

International Nuclear Information System (INIS)

Molinski, V.J.; Wilczewski, J.A.

1977-01-01

A method of preparing improved technetium-99m labeled radiodiagnostic agents by reducing technetium-99m with stannous tartrate is described. Such radiodiagnostic agents are useful in scintigraphic examinations of the bone and lung

Technetium removal from aqueous wastes

International Nuclear Information System (INIS)

Fletcher, P.A.; Jones, C.P.; Junkison, A.R.; Turner, A.D.; Kavanagh, P.R.

1992-03-01

The research discussed in this report has compared several ''state of the art'' techniques for the removal of traces of the radionuclide, technetium, from aqueous wastes. The techniques investigated were: electrochemical reduction to an insoluble oxide, electrochemical ion exchange, seeded ultrafiltration and chemical reduction followed by filtration. Each technique was examined using a simulant based upon the waste generated by the Enhanced Actinide Removal Plant (EARP) at Sellafield. The technique selected for further investigation was direct electrochemical reduction which offers an ideal route for the removal of technetium from the stream (DFs 10-100) and can be operated continuously with a low power consumption 25 kW for the waste generated by EARP. Cell designs for scale up have been suggested to treat the 1000m 3 of waste produced every day. Future work is proposed to investigate the simultaneous removal of other key radionuclides, such as ruthenium, plutonium and cobalt as well as scale up of the resulting process and to investigate the effect of these other radionuclides on the efficiency of the electrochemical reduction technique for the removal of technetium. Total development and full scale plant costs are estimated to be of the order of 5 pounds - 10M, with a time scale of 5 -8 years to realisation. (author)

Investigation on chemistry of model compounds of technetium radiopharmaceuticals

International Nuclear Information System (INIS)

Muenze, R.; Hartmann, E.

1983-01-01

The report summarized experimental and theoretical results concerning the chemical structures and the biodistribution of hydrophilic technetium chelates with hydroxycarboxylic and aminopolycarboxylic acids, thiol compounds and aliphatic and aromatic nitrogen compounds as ligands. Methods which are suitable for synthesizing and characterizing defined chelates of Tc(V), Tc(IV) and Tc(III) have been developed for crystlline substances and species in solution, respectively. For certain types of technetium chelates three dimensional structure models were calculated from atomic parameters. The electron energies and electron distribution of Tc(V) thiol compounds were calculated by quantum chemical methods in order to interprete physical properties of these substances. Biodistribution studies revealed relationships between the osteotropic behaviour and the structure of phosphorous and non-phosphorous technetium chelates and between the kidney uptake and ligand exchange ability of Tc(V) hydroxycarboxylates. Important parameters for the production of technetium-99m kits have been elaborated and used for the optimization of radiopharmaceuticals (bone-, kidney and hepatobiliaer agents). (author)

Technetium SPECT agents for imaging heart and brain

International Nuclear Information System (INIS)

Linder, K.E.

1990-01-01

One major goal of radiopharmaceutical research has been the development of technetium-based perfusion tracers for SPECT imaging of the heart and brain. The recent clinical introduction of the technetium complexes HM-PAO, ECD and DMG-2MP for brain imaging, and of CDO-MEB and MIBI for heart imaging promises to revolutionize the field of nuclear medicine. All of these agents appear to localize in the target tissue in proportion to blood flow, but their mechanisms of localization and/or retention may differ quite widely. In this talk, a survey of the new technetium SPECT agents will be presented. The inorganic and biological chemistry of these complexes, mechanisms of uptake and retention, QSAR studies, and potential clinical applications are discussed

Prevention of organic iodide formation in BWR's

International Nuclear Information System (INIS)

Karjunen, T.; Laitinen, T.; Piippo, J.; Sirkiae, P.

1996-01-01

During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR's as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs

Synthesis and Properties of Metallic Technetium and Technetium-Zirconium Alloys as Transmutation Target and Radioactive waste storage form in the UREX+1 Process

Energy Technology Data Exchange (ETDEWEB)

Hartmann, Thomas [Idaho State University/Idaho National Laboratory, 1776 Science Center Drive, Idaho Falls, ID 83402 (United States)]|[Harry Reid Center, University Nevada - Las Vegas, 4505 Maryland Parkway, Las Vegas, NV (United States); Poineau, Frederic; Czerwinski, Kenneth R. [Harry Reid Center, University Nevada - Las Vegas, 4505 Maryland Parkway, Las Vegas, NV (United States)

2008-07-01

In the application of UREX+1 process, technetium will be separated together with uranium and iodine within the first process step. After the separation of uranium, technetium and iodine must be immobilized by their incorporation in a suitable waste storage-form. Based on recent activities within the AFCI community, a potential candidate as waste storage form to immobilize technetium is to alloy the metal with excess zirconium. Alloys in the binary Tc-Zr system may act as potential transmutation targets in order to transmute Tc-99 into Ru-100. We are presenting first results in the synthesis of metallic technetium, and the synthesis of equilibrium phases in the binary Tc-Zr system at 1400 deg. C after arc-melting and isothermal annealing under inert conditions. Samples were analyzed using X-ray powder diffraction, Rietveld analysis, scanning electron microscopy, and electron probe micro-analysis, which allows us to construct the binary Tc-Zr phase diagram for the isothermal section at 1400 deg. C. (authors)

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

Kinetic method for determination of iodide ion ultramicroamounts. Kineticheskij sposob opredeleniya ul'tramikrokolichestv iodid-ionov

Energy Technology Data Exchange (ETDEWEB)

Barkauskas, Yu K; Ramanauskas, Eh I

1980-04-03

A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 ..mu..g iodide per 100 l of solution. More than 10/sup 5/-multiple amounts of K/sup +/, Na/sup +/, NH/sub 4//sup +/, Ba/sup 2 +/, Al/sup 3 +/, Cu/sup 2 +/, Mg/sup 2 +/, SO/sub 4//sup 2 -/, Cl/sup -/, MoO/sub 4//sup 2 -/, NO/sub 3//sup -/, ClO/sub 3//sup -/, IO/sub 3//sup -/, IO/sub 4//sup -/, ClO/sub 4//sup -/, BrO/sub 3//sup -/; 10/sup 5/-10/sup 3/-multiple amounts of Cr/sup 3 +/, Fe/sup 3 +/, Sn/sup 2 +/, S/sup 2 -/, MnO/sub 4//sup -/, NO/sub 2//sup -/ etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag/sup +/, Hg/sub 2//sup 2 +/ do.

Radiation decomposition of technetium-99m radiopharmaceuticals

International Nuclear Information System (INIS)

Billinghurst, M.W.; Rempel, S.; Westendorf, B.A.

1979-01-01

Technetium-99m radiopharmaceuticals are shown to be subject to autoradiation-induced decomposition, which results in increasing abundance of pertechnetate in the preparation. This autodecomposition is catalyzed by the presence of oxygen, although the removal of oxygen does not prevent its occurrence. The initial appearance of pertechnetate in the radiopharmaceutical is shown to be a function of the amount of radioactivity, the quantity of stannous ion used, and the ratio of /sup 99m/Tc to total technetium in the preparation

In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

Directory of Open Access Journals (Sweden)

Eleonore Haltner-Ukomadu

2018-01-01

Full Text Available An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility of the antiviral compound enisamium iodide (4-(benzylcarbamoyl-1-methylpyridinium iodide were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp of enisamium iodide was assessed using human colon carcinoma (Caco-2 cells at three concentrations. The solubility of enisamium iodide in four buffer solutions from pH 1.2 to 7.5 is about 60 mg/mL at 25 °C, and ranges from 130 to 150 mg/mL at 37 °C, depending on the pH. Based on these results, enisamium iodide can be classified as highly soluble. Enisamium iodide demonstrated low permeability in Caco-2 experiments in all tested concentrations of 10–100 μM with permeability coefficients between 0.2 × 10−6 cm s−1 and 0.3 × 10−6 cm s−1. These results indicate that enisamium iodide belongs to class III of the Biopharmaceutics Classification System (BCS due to its high solubility and low permeability. The bioavailability of enisamium iodide needs to be confirmed in animal and human studies.

Study of radiation formation of methyl-iodide Part 2

International Nuclear Information System (INIS)

Bartonicek, B.; Schweiner, Z.; Bednar, J.; Hladky, E.

1975-01-01

Purified methane, ethylene, iodine, methyl iodide, ethyl iodide and hydrogen iodide were irradiated and/or pyrolyzed in Pyrex ampoules by 60 Co-γ-radiation at temperatures between 150 and 450 deg C. The results on radiolysis and pyrolysis were as follows: 1., The most thermally stable product is hydrogen iodide in which already at 450 deg C essen-tially all originally present iodine appears. 2., The radiolytic formation of methyl iodide and hydrogen iodide is positively influenced by the rise in temperature, This and the absolute values of yields indicate a chain mechanism of radiolytic (and pyrolytic) decomposition of the mixture. 3., The ratio of equilibrium concentrations [HI]/[CH 3 I] increases with increasing temperature of pyrolysis showing that HI is the end product of the thermal chain reaction. Methyl iodide is likely to contribute (by its thermal decomposition) to the initiation and propagation of this chain reaction. 4., The negligible temperature dependence of G(H 2 ) and the absence of molecular hydrogen among the products of pyrolytic decomposition of methane-iodine mixtures shows, that (up to 450 deg C) H atoms do not play any role in the thermal chain decomposition of these mixtures. (K.A.)

Aqueous-gas phase partitioning and hydrolysis of organic iodides

International Nuclear Information System (INIS)

Glowa, G.A.; Wren, J.C.

2003-01-01

The volatility and decomposition of organic iodides in a reactor containment building are important parameters to consider when assessing the potential consequences of a nuclear reactor accident. However, there are few experimental data available for the volatilities (often reported as partition coefficients) or few rate constants regarding the decomposition (via hydrolysis) of organic iodides. The partition coefficients and hydrolysis rate constants of eight organic iodides, having a range of molecular structures, have been measured in the current studies. This data, and data accumulated in the literature, have been reviewed and discussed to provide guidelines for appropriate organization of organic iodides for the purpose of modelling iodine behaviour under postulated nuclear reactor accident conditions. After assessment of the partition coefficients and their temperature dependences of many classes of organic compounds, it was found that organic iodides could be divided into two categories based upon their volatility relative to molecular iodine. Similarly, hydrolysis rates and their temperature dependences are assigned to the two categories of organic iodides. (author)

Analysis of one thousand liver scans carried out using technetium phytate

Energy Technology Data Exchange (ETDEWEB)

Pasquier, J; de Laforte, C; Roux, F; Bisset, J P; Paulin, R [Centre Hospitalier Universitaire de la Timone, 13 - Marseille (France)

1977-10-01

One thousand liver scans were carried out using technetium phytate. This soluble compound is transformed in the circulating blood into a colloid by chelation of serum calcium, thereby forming a macromolecular phytate of calcium and technetium. The presenting symptoms are compared with the isotopic findings. This microcolloid has the advantages common to all technetium tracers and, in addition, is easy to prepare and has the advantage of a distribution between the liver, spleen, and bone of the same type as that seen with colloidal gold 198 without the dosimetric problems associated with the latter. Although it has a level of hepatic fixation which is less than that of certain sulphide complexes of technetium it appears to provide a better reflection of the colloidopexic function of the liver.

The incorporation of technetium into a representative low-activity waste glass

International Nuclear Information System (INIS)

Ebert, W.L.; Bakel, A.J.; Bowers, D.L.; Buck, E.C.; Emery, J.W.

1997-01-01

A glass that has been tested to understand the corrosion behavior of waste glasses with high soda contents for immobilizing Hanford incidental wastes has been made by melting crushed glass with either TcO 2 or NaTcO 4 at 1,100--1,300 C. Incorporation of technetium in the glass was affected by solubility or kinetic effects. Metallic technetium inclusions formed in all the TcO 2 -doped glasses. Inclusions also formed in glasses with added NaTcO 4 that were melted at 1,100 C, but a glass melted at 1,200 C did not contain detectable inclusions. The presence of Tc-bearing inclusions complicates the interpretation of results from dissolution tests because of the simultaneous release of technetium from more than one phase, the unknown surface areas of each phase, and the possible incorporation of technetium that is released from one phase into another phase. A glass containing about 0.15 mass % Tc dissolved in the glass is being used in dissolution tests to study the release behavior of technetium

Linking loss of sodium-iodide symporter expression to DNA damage

Energy Technology Data Exchange (ETDEWEB)

Lyckesvärd, Madeleine Nordén [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Kapoor, Nirmal [Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Ingeson-Carlsson, Camilla; Carlsson, Therese [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Karlsson, Jan-Olof [Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden); Postgård, Per; Himmelman, Jakob; Forssell-Aronsson, Eva [Department of Radiation Physics, University of Gothenburg, Göteborg (Sweden); Hammarsten, Ola [Department of Clinical Chemistry, University of Gothenburg, Göteborg (Sweden); Nilsson, Mikael, E-mail: mikael.nilsson@gu.se [Sahlgrenska Cancer Center, University of Gothenburg, Göteborg (Sweden); Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg (Sweden)

2016-05-15

Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (<1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. - Highlights: • DNA damage inhibits polarized iodide transport in normal thyroid cells. • Down-regulation of NIS expression is mediated by activation of the ATM kinase. • Long-term ATM inhibition also represses NIS-mediated iodide transport. • IGF-1 rescues NIS expression and iodide transport in DNA-damaged cells.

Linking loss of sodium-iodide symporter expression to DNA damage

International Nuclear Information System (INIS)

Lyckesvärd, Madeleine Nordén; Kapoor, Nirmal; Ingeson-Carlsson, Camilla; Carlsson, Therese; Karlsson, Jan-Olof; Postgård, Per; Himmelman, Jakob; Forssell-Aronsson, Eva; Hammarsten, Ola; Nilsson, Mikael

2016-01-01

Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (<1 nM) calicheamicin blocked NIS mRNA expression and transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. - Highlights: • DNA damage inhibits polarized iodide transport in normal thyroid cells. • Down-regulation of NIS expression is mediated by activation of the ATM kinase. • Long-term ATM inhibition also represses NIS-mediated iodide transport. • IGF-1 rescues NIS expression and iodide transport in DNA-damaged cells.

Bronchoalveolar lavage and technetium-99m glucoheptonate imaging in chronic eosinophilic pneumonia

International Nuclear Information System (INIS)

Lieske, T.R.; Sunderrajan, E.V.; Passamonte, P.M.

1984-01-01

A patient with chronic eosinophilic pneumonia was evaluated using bronchoalveolar lavage, technetium-99m glucoheptonate, and transbronchial lung biopsy. Bronchoalveolar lavage revealed 43 percent eosinophils and correlated well with results of transbronchial lung biopsy. Technetium-99m glucoheptonate lung imaging demonstrated intense parenchymal uptake. After eight weeks of corticosteroid therapy, the bronchoalveolar lavage eosinophil population and the technetium-99m glucoheptonate uptake had returned to normal. We suggest that bronchoalveolar lavage, with transbronchial lung biopsy, is a less invasive way than open lung biopsy to diagnose chronic eosinophilic pneumonia. The mechanism of uptake of technetium-99m glucoheptonate in this disorder remains to be defined

Accelerators for forming cationic technetium complexes useful as radiodiagnostic images

International Nuclear Information System (INIS)

Tweedle, M.F.

1985-01-01

This invention relates to compositions for making cationic radiodiagnostic agents and, in particular, to accelerator compounds for labelling such cationic radiodiagnostic agents, kits for preparing such 99m Tc-labelled cationic radiodiagnostic agents with technetium, and methods for labelling such cationic radiodiagnostic agents with technetium

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.

Absorption of technetium by plants in relation to soil type contamination level and time

Energy Technology Data Exchange (ETDEWEB)

Mousny, J.M.; Myttenaere, C. (Louvain Univ. (Belgium). Lab. de Physiologie Vegetale)

1981-01-01

Plants of Pisum sativum (var. Merveille de Kelvedon) were grown on seven typical european soils contaminated with different levels of /sup 99/Tc(0.17; 1.7 and 17 ..mu..Ci/kg). Added initially as pertechnetate, the technetium absorption has been studied for three successive cultures. The translocation of technetium from soil to plant leaves is high, but its transfer is reduced in soils rich in organic matter (Fen) or poorly drained (Braunerde). Aging reduces the technetium transfer and modify its relative distribution in plant (relatively more technetium is found in fruits); these results let suppose some modification of the technetium chemical form in soils with time.

Analysis of one thousand liver scans carried out using technetium phytate

International Nuclear Information System (INIS)

Pasquier, J.; Laforte, C. de; Roux, F.; Bisset, J.P.; Paulin, R.

1977-01-01

One thousand liver scans were carried out using technetium phytate. This soluble compound is transformed in the circulating blood into a colloid by chelation of serum calcium, thereby forming a macromolecular phytate of calcium and technetium. The presenting symptoms are compared with the isotopic findings. This microcolloid has the advantages common to all technetium tracers and, in addition, is easy to prepare and has the advantage of a distribution between the liver, spleen and bone of the same type as that seen with colloidal gold 198 without the dosimetric problems associated with the latter. Although it has a level of hepatic fixation which is less than that of certain sulphide complexes of technetium it appears to provide a better reflection of the colloidopexic function of the liver [fr

Binuclear complexes of technetium. Evidence for bis(terdentate)bidentate coordination by the bridging ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine to technetium(V)

International Nuclear Information System (INIS)

Du Preez, J.G.H.; Gerber, T.I.A.; Gibson, M.L.; Geyser, R.

1990-01-01

The authors have used the potentially bis(terdentate) nitrogen aromatic heterocyclic ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) to prepare mono- and bimetallic technetium(V) complexes bound to tppz. The stimulus for the development of the coordination chemistry of the man-made element technetium is provided by the use of complexes of this element as anatomical imaging agents in nuclear medicine. Although the chemistry of technetium(V) with nitrogen donor ligands is well understood, no complexes have been prepared using potentially terdentate neutral nitrogen donor ligands of this metal in the +5 oxidation state

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

Potassium iodide capsule treatment of feline sporotrichosis.

Science.gov (United States)

Reis, Erica G; Gremião, Isabella D F; Kitada, Amanda A B; Rocha, Raphael F D B; Castro, Verônica S P; Barros, Mônica B L; Menezes, Rodrigo C; Pereira, Sandro A; Schubach, Tânia M P

2012-06-01

Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

The quality control of technetium-99m radiopharmaceuticals produced at the AAEC Research Establishment

International Nuclear Information System (INIS)

Farrington, K.J.

1983-08-01

The methods of quality control used for technetium-99m radiopharmaceuticals produced at the AAEC Research Establishment are described for both non-fission and fission derived sources of sodium pertechnetate, technetium-99m labelled radipopharmaceuticals, and reagent kits produced for technetium-99m labelling

Prevention of organic iodide formation in BWR`s

Energy Technology Data Exchange (ETDEWEB)

Karjunen, T [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland); Laitinen, T; Piippo, J; Sirkiae, P [VTT Manufacturing Technology (Finland)

1996-12-01

During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR`s as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs.

The radiopharmaceuticals labelled with technetium-99m and the radiopharmacy

International Nuclear Information System (INIS)

Bodenant, V.

1998-01-01

In less than fifty years, the place of nuclear medicine is become primordial. Among all the radiopharmaceuticals used in nuclear medicine, the technetium-99m is the most used because of its physico-chemical properties and its great availability with the molybdenum-99m - technetium-99m generator. Since 1992, the radiopharmaceuticals, the packages, the generators are included in the pharmaceutic monopole. They are now under the reliability of the radio-pharmacist. This thesis has for object to introduce these different radiopharmaceuticals labelled with technetium-99m and to show the primordial place of the radio-pharmacist in a service of nuclear medicine. (N.C.)

Electrochemical preparation of technetium hydroxyethylidene diphosphonate radiopharmaceuticals

International Nuclear Information System (INIS)

Scott, R.B.

1984-01-01

This work describes the liquid chromatographic and electrochemical analysis of electrogenerated technetium hydroxyethylidene diphosphonate (HEDP) complexes, and studies the effectiveness of the resulting bone imaging agents. Anion exchange High Performance Liquid Chromatography is used to separate components, and γ emission is used as the detection mode. The reaction mixtures were prepared at a series of reduction potentials and pH values, at both carrier added and no carrier added technetium levels. The results indicate that all three parameters affect the final complex composition to varying degrees. By optimizing the conditions, a preparation was made which results in a high percentage of a Tc-HEDP complex thought to be a very good home imager. This component was isolated chromatographically and injected into female Sprague-Dawley rats. Comparisons were run on the uptake for seven tissue types at two incubation times. Mercury and Reticulated Vitreous Carbon were used as the working electrode materials, and it is shown how reduced technetium will significantly alter the electrode characteristics, where a conditioned electrode will produce different complexes from those produced at fresh electrode material. By employing coulometric analysis as the preparation was reduced, an n value of 4 was calculated for a particular complex. This procedure involved tracking the radioactive technetium species carefully to account for all electrons used in the system. Finally, an electrochemical detection method for HEDP was explored, utilizing the property of mercury complexation. Anodic sweep Differential Pulse Polarography gives an analytical signal for HEDP at +0.250 V vs Ag/AgCl

Determination of technetium-99 from complex matrix

International Nuclear Information System (INIS)

Lixiong Wang; Lei Tang; Tongzai Yang; Yanqiu Yang; Liang Yang

2013-01-01

This paper reports an approach that can be used for efficient separation and determination of 99 Tc (as pertechnetate) after contamination of the environment by nuclear materials. The samples were decomposed by fusion in a mixture of potassium hydroxide and potassium nitrate. After fusion, technetium remains as the pertechnetate anion (TcO 4 - ). The technetium was isolated from the sample by technique combining solvent extraction, anion exchange, then, again, solvent extraction. After separation, 99 Tc was measured by isotope-dilution mass spectrometry with 97 Tc as spike. This method yielded nanogram detection limits for 99 Tc. (author)

Kinetics of [123I]iodide uptake and discharge by perchlorate in studies of inhibition of iodide binding by antithyroid drugs

International Nuclear Information System (INIS)

McCruden, D.C.; Connell, J.M.C.; Alexander, W.D.; Hilditch, T.E.

1985-01-01

Thyroidal binding of iodide was studied by kinetic analysis of [ 123 ]iodide uptake and its discharge by perchlorate in 80 hyperthyroid subjects receiving antithyroid drug therapy. Five dosage regimens ranging from 5 mg carbimazole twice daily to 15 mg methimazole twice daily were studied. Binding inhibition was estimated at 5-7 h after drug as an index of the mean effect of the 12 hourly regimen. In all cases, except one in the lowest dose group, binding was found to be markedly reduced with mean binding rates ranging from 0.002 to 0.020 min -1 (normal > 0.15 min -1 ). The net clearance of iodide in the lowest dose group was reduced to a mean value near the upper limit of the euthyroid range, whereas in the highest dose group it lay at the lower limit of the euthyroid range. These results were reflected in the serum thyroid hormone response. There was a reducing incidence of inadequate control of hyperthyroidism and an increasing incidence of hypothyroidism with increasing thiourylene dose. The exit rate constant of free iodide for the various doses showed values from 0.048 to 0.055 min -1 . Correpsonding mean values for the discharge rate constant after perchlorate were 0.087 to 0.105 min -1 . This suggests that perchlorate increases the rate of iodide release from the thyroid gland. Studies at a later interval after drug (12-14 h) showed no change in discharge rate constant. This leads to the conclusion that perchlorate may further inhibit iodide binding in subjects receiving antithyroid drug therapy. (author)

Reduction And Sequestration Of Pertechnetate To Technetium Dioxide And Protection From Reoxidation

International Nuclear Information System (INIS)

Duncan, J. B.; Johnson, J. M.; Moore, R. C.; Hagerty, K.; Rhodes, R. N.; Huber, H. J.; Moore, W. P.

2012-01-01

This effort is part of the technetium management initiative and provides data for the handling and disposition of technetium. To that end, the objective of this effort was to challenge tin(lI)apatite (Sn(II)apatite) against double-shell tank 241-AN-105 simulant spiked with pertechnetate (TcO 4 ). The Sn(II)apatite used in this effort was synthesized on site using a recipe developed at and provided by Sandia National Laboratories; the synthesis provides a high quality product while requiring minimal laboratory effort. The Sn(ll)apatite reduces pertechnetate from the mobile +7 oxidation state to the non-mobile +4 oxidation state. It also sequesters the technetium and does not allow for re-oxidization to the mobile +7 state under acidic or oxygenated conditions within the tested period of time (6 weeks). Previous work indicated that the Sn(II) apatite can achieve an ANSI leachability index in Cast Stone of 12.8. The technetium distribution coefficient for Sn(lI)apatite exhibited a direct correlation with the pH of the technetium-spiked simulant media

Geochemistry of natural technetium and plutonium

International Nuclear Information System (INIS)

Curtis, D.B.; Cappis, J.H.; Perrin, R.E.; Rokop, D.J.

1987-01-01

Technetium and plutonium in unprocessed nuclear reactor wastes are major concerns with regard to their containment in the geologic environment. Both nuclides have long half-lives; therefore, they will exist long after engineered barriers can be considered reliable. Consequently, strategies for the containment of these two elements depend on their retention in the geologic barrier until they have decayed to innocuous levels. Because these are the rarest elements in nature, there have been few direct observations of their geochemical behavior; predictions concerning their fate in the repository are based on properties that can be observed in the laboratory. The authors are attempting to complement the laboratory work by studying the geochemistry of natural plutonium and technetium. Ratios of anthropogenic to naturally occurring isotopes are discussed

High pressure liquid chromatographic assay of technetium in solutions of sodium pertechnetate produced at the AAEC Research Establishment

International Nuclear Information System (INIS)

Farrington, K.J.

1985-12-01

High pressure liquid chromatography (HPLC) is used for the assay of nanogram quantities of technetium and to determine technetium in decayed pharmaceutical products, derived from three methods of manufacture. These methods of manufacture give comparably low levels of technetium-99, at the time of collection of the solution. However, when the solutions are used to produce ready-to-inject technetium-99m, high levels of technetium-99 are present at the time of calibration, which is the day after the collection date. Where sensitive reagent kits are to be labelled, freshly collected solutions of technetium-99m should be used. The HPLC assay is a valuable technique for the quality control of technetium-based radiopharmaceuticals, and for investigation of methods of manufacture of technetium-99m. Experimental studies confirmed the findings of previous workers

Determination of a method to inhibit technetium migration at the repository

International Nuclear Information System (INIS)

Statler, V.; Tulenko, J.; Cloke, P.

1990-01-01

The long-term migration of 99 Tc (213,000-yr half-life) must be considered when examining the disposal of spent nuclear fuel in a geologic repository. This report outlines an investigation of the effects of iron, tin, stannous chloride, copper, manganese, and vanadium as reactants added to a mixture of technetium and J-13 well water to cause technetium precipitation. The J-13 well water was chosen because it is representative of the groundwater located at Yucca Mountain. A state-of-the-art computer software package, EQ3/6, was developed at Lawrence Livermore National Laboratory and was utilized in this study to project the result when metallic iron, tin, copper, manganese, and vanadium and the compound stannous chloride are individually added to a mixture of metallic technetium and J-13 well water. The computer codes in this study indicate that the problems associated with technetium migration at the federal repository are not insurmountable if a reactant capable of producing reducing conditions to the incoming groundwater is integrated into the waste package. Further work will focus on the laboratory experimentation to validate the computer results and to determine the best materials and configurations to inhibit technetium migration at the repository

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer-A Review.

Science.gov (United States)

Gonçalves, Carlos F L; de Freitas, Mariana L; Ferreira, Andrea C F

2017-06-12

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer.

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer—A Review

Science.gov (United States)

Gonçalves, Carlos F. L.; de Freitas, Mariana L.; Ferreira, Andrea C. F.

2017-01-01

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer. PMID:28604619

Photoluminescence Enhancement in Formamidinium Lead Iodide Thin Films

NARCIS (Netherlands)

Fang, Hong-Hua; Wang, Feng; Adjokatse, Sampson; Zhao, Ni; Loi, Maria Antonietta

2016-01-01

Formamidinium lead iodide (FAPbI(3)) has a broader absorption spectrum and better thermal stability than the most famous methylammonium lead iodide, thus exhibiting great potential for photovoltaic applications. In this report, the light-induced photoluminescence (PL) evolution in FAPbI(3) thin

The Evaluation of Novel Tin Materials for the Removal of Technetium from Groundwater

Energy Technology Data Exchange (ETDEWEB)

Parker, Kent E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wellman, Dawn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-06-30

Technetium-99 (⁹⁹Tc) is present at several U.S. Department of Energy (DOE) facilities, including the Hanford, Oak Ridge, Paducah, Portsmouth, and Savannah River sites. Due to its mobility, persistence, and toxicity in the environment, developing means to immobilize and/or remove technetium from the environment is currently a top priority for DOE. However, there are currently very few approaches that effectively manage the risks of technetium to human health and the environment. The objective of this study is to evaluate novel synthetic materials that could enable direct removal of technetium from groundwater. The following report •assesses the viability of existing methodologies for synthesis of tin (II) apatite for in situ formation and remediation of ⁹⁹Tc within the subsurface environment •discusses the development of alternative methodologies for production of tin (II) apatite •evaluates nanoporous tin phosphate materials for removal of technetium from groundwater.

Method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions

Science.gov (United States)

Horwitz, E. Philip; Delphin, Walter H.

1979-07-24

A method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions containing these and other values by contacting the waste solution with an extractant of tricaprylmethylammonium nitrate in an inert hydrocarbon diluent which extracts the palladium and technetium values from the waste solution. The palladium and technetium values are recovered from the extractant and from any other coextracted values with a strong nitric acid strip solution.

Ligand-free, protein-bound technetium-99m. Evidence for tumour localisation

International Nuclear Information System (INIS)

Jakovljevic, A.C.; Pojer, P.M.

1984-11-01

An hypothesis that cations accumulate in tumours independent of ligand is tested. A preparation of technetium-99m known to be ligand-free (that is, the technetium is protein bound and no other ligand is injected) has been shown to accumulate in a T-cell lymphoma

ASSESSMENT OF TECHNETIUM LEACHABILITY IN CEMENT-STABILIZED BASIN 43 GROUNDWATER BRINE

International Nuclear Information System (INIS)

Duncan, J.B.; Cooke, G.A.; Lockrem, L.L.

2009-01-01

This report documents the effort to sequester technetium by the use of getters, reductants (tin(II) apatite and ferrous sulfate), sorbents (A530E and A532E ion exchange resins), and cementitious waste form. The pertechnetate form of technetium is highly soluble and mobile in aerobic (oxidizing) environments.

Technetium behaviour in Boom Clay - a laboratory and field study

International Nuclear Information System (INIS)

Baston, G.M.N.; Ilett, D.J.; Cowper, M.M.; Pilkington, N.J.; Tweed, C.J.; Williams, S.J.; Canniere, P.R. de; Wang, L.

2002-01-01

This paper describes a study of technetium solubility and migration under chemical conditions representative of those prevailing in a Boom Clay environment. Laboratory and in situ measurements yielded similar aqueous concentrations of technetium, of about 1 x 10 -8 mol dm -3 , close to the concentrations measured for hydrated technetium(IV) oxide TcO 2 .1.6H 2 O in the solubility studies. From fitting the curves of the Tc concentrations as function of time, distribution coefficient (K d ) values were estimated to lie between 0.8 cm 3 g -1 and 1.8 cm 3 g -1 . Exposure of the system at 80 C and to γ-radiation dose rates of several hundred Gy h -1 resulted in only minor differences in behaviour. (orig.)

Effect of nitrogen and oxygen on radiolysis of iodide solution

Energy Technology Data Exchange (ETDEWEB)

Karasawa, H; Endo, M [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

1996-12-01

The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

Research on solubility characteristics of gaseous methyl iodide

International Nuclear Information System (INIS)

Zhou Yanmin; Sun Zhongning; Gu Haifeng; Wang Junlong

2014-01-01

With the deionized water as the absorbent, the solubility characteristics of the gaseous methyl iodide were studied under different temperature and pressure conditions, using a dynamic measuring method. The results show that within the range of experiment parameters, namely temperature is below 80℃ and pressure is lower than 0.3 MPa, the physical dissolution process of gaseous methyl iodide in water obeys Henry's law. The solubility coefficient under different temperature and pressure conditions was calculated based on the measurement results. Further research indicates that at atmospheric pressure, the solubility coefficient of methyl iodide in water decreases exponentially with the increase of temperature. While the pressure changes from 0.1 MPa to 0.3 MPa with equal interval, the solubility coefficient also increases linearly. The variation of the solubility coefficient with temperature under different pressure conditions all decreases exponentially. An equation is given to calculate the solubility coefficient of methyl iodide under different pressure and temperature conditions. (authors)

Kinetic method for determination of iodide ion ultramicroamounts

International Nuclear Information System (INIS)

Barkauskas, Yu.K.; Ramanauskas, Eh.I.

1980-01-01

A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 μg iodide per 100 l of solution. More than 10 5 -multiple amounts of K + , Na + , NH 4+ , Ba 2 + , Al 3 + , Cu 2 + , Mg 2 + , SO 4 2 - , Cl - , MoO 4 2 - , NO 3- , ClO 3- , IO 3- , IO 4- , ClO 4- , BrO 3- ; 10 5 -10 3 -multiple amounts of Cr 3 + , Fe 3 + , Sn 2 + , S 2 - , MnO 4- , NO 2- etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag + , Hg 2 2 + do

Oscillator strengths for neutral technetium

International Nuclear Information System (INIS)

Garstang, R.H.

1981-01-01

Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations

Products of the reaction between methylene iodide and tertiary arsines

International Nuclear Information System (INIS)

Gigauri, R.D.; Arabuli, L.G.; Machaidze, Z.I.; Rusiya, M.Sh.

2005-01-01

Iodides of iodomethylenetrialkyl(aryl) arsonium were synthesized with high yields as a result of interaction between methylene iodide and tertiary arsines. Exchange reactions of the iodides prepared with lead(II) nitrate in water-alcohol solutions gave rise to formation of iodomethylenetrialkyl(aryl) arsonium nitrates. All the products prepared were characterized by data of elementary analysis, IR spectroscopy, conductometry and melting points measurements [ru

Thermal neutron cross section measurements for technetium-99

International Nuclear Information System (INIS)

Yates, M.A.; Schroeder, N.C.; Fowler, M.M.

1993-01-01

Technetium, because of its long half-like (213,000 years) and ability to migrate in the environment, is a primary contributor to the long-term radioactivity related risk associated with geologic nuclear waste disposal. One proposal for converting technetium to an environmentally benign element investigating transmutation with an accelerator-based system, (i.e., Accelerator Transmutation of Waste, ATW). Planning for efficient processing of technetium through the transmuter will require knowledge of the thermal neutron cross section for the 99 Tc (n,γ) 100 Tc reaction. The authors have recently remeasured this cross section. Weighed aliquots (19-205 μg) of a NIST traceable 99 Tc standard were irradiated for 30-150 sec using the pneumatic open-quotes rabbitclose quotes system of LANL's Omega West Reactor. The two gamma rays from the 15.7-sec half-life product were measured immediately after irradiation on a high-resolution Ge detector. Thermal fluxes were measured using gold foils and Cd wrapped gold foils. The observation cross section is 19 ± 1 b. This agrees well with the 1977 value but has half the uncertainty

Permeation of iodide from iodine-enriched yeast through porcine intestine.

Science.gov (United States)

Ryszka, Florian; Dolińska, Barbara; Zieliński, Michał; Chyra, Dagmara; Dobrzański, Zbigniew

2013-01-01

Iodine deficiency is a common phenomenon, threatening the whole global human population. Recommended daily intake of iodine is 150 μg for adults and 250 μg for pregnant and breastfeeding women. About 50% of human population can be at risk of moderate iodine deficiency. Due to this fact, increased iodine supplementation is recommended, through intake of iodized mineral water and salt iodization. The aim of this study was to investigate permeation and absorption of iodide from iodine bioplex (experimental group) in comparison with potassium iodide (controls). Permeation and absorption processes were investigated in vitro using a porcine intestine. The experimental model was based on a standard Franz diffusion cell (FD-Cell). The iodine bioplex was produced using Saccharomyces cerevisiae yeast and whey powder: iodine content - 388 μg/g, total protein - 28.5%, total fat - 0.9%., glutamic acid - 41.2%, asparaginic acid - 29.4%, lysine - 24.8%; purchased from: F.Z.N.P. Biochefa, Sosnowiec, Poland. Potassium iodide was used as controls, at 388 μg iodine concentration, which was the same as in iodine-enriched yeast bioplex. A statistically significant increase in iodide permeation was observed for iodine-enriched yeast bioplex in comparison with controls - potassium iodide. After 5h the total amount of permeated iodide from iodine-enriched yeast bioplex was 85%, which is ~ 2-fold higher than controls - 37%. Iodide absorption was by contrast statistically significantly higher in controls - 7.3%, in comparison with 4.5% in experimental group with iodine-enriched yeast bioplex. Presented results show that iodide permeation process dominates over absorption in case of iodine-enriched yeast bioplex.

Method of removing alkyl iodides or mixtures of iodine and alkyl iodides from a gas phase and an aqueous solution phase by utilizing ion exchange resins

International Nuclear Information System (INIS)

Shimizu, Hiroshi; Mizuuchi, Noboru; Yokoyama, Fumio.

1967-01-01

Alkyl iodides and mixtures of iodine and alkyl iodides are removed from a gas phase and an aquous solution phase by using solely an anion exchange resin containing a tertiary amine or together with an anion exchange resin containing quarternary ammonium compound. The resin containing the quarternary ammonium compound is employed mainly to remove iodine, and the resin containing the tertiary amine serves mainly to remove alkyl iodides. The method can be applied to collecting a majority of the methyl iodide as well as the radioactive iodine produced in the atmosphere of a reactor in case of a fuel accident. In embodiments, it is desirable to maintain the sufficient moisture content of the anion exchange resins at a sufficient moisture level so as not to reduce the migration speed of the iodine and alkyl iodides. The iodine and alkyl iodide can be produced with high efficiency and stability independently of the relative humidity of the gas phase. In examples, a solution which consists of 20.5 mg/l of iodine and 42.2mg/l of methyl iodide flew through a column of Amberite IRA-93 alone or blended with IRA-900 at a speed of 15 /hr. respectively. The resins were able to treat 400 times their equivalent in water. (Iwakiri, K.)

Laccase-catalyzed oxidation of iodide and formation of organically bound iodine in soils.

Science.gov (United States)

Seki, Miharu; Oikawa, Jun-ichi; Taguchi, Taro; Ohnuki, Toshihiko; Muramatsu, Yasuyuki; Sakamoto, Kazunori; Amachi, Seigo

2013-01-02

Laccase oxidizes iodide to molecular iodine or hypoiodous acid, both of which are easily incorporated into natural soil organic matter. In this study, iodide sorption and laccase activity in 2 types of Japanese soil were determined under various experimental conditions to evaluate possible involvement of this enzyme in the sorption of iodide. Batch sorption experiment using radioactive iodide tracer ((125)I(-)) revealed that the sorption was significantly inhibited by autoclaving (121 °C, 40 min), heat treatment (80 and 100 °C, 10 min), γ-irradiation (30 kGy), N(2) gas flushing, and addition of reducing agents and general laccase inhibitors (KCN and NaN(3)). Interestingly, very similar tendency of inhibition was observed in soil laccase activity, which was determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a substrate. The partition coefficient (K(d): mL g(-1)) for iodide and specific activity of laccase in soils (Unit g(-1)) showed significant positive correlation in both soil samples. Addition of a bacterial laccase with an iodide-oxidizing activity to the soils strongly enhanced the sorption of iodide. Furthermore, the enzyme addition partially restored iodide sorption capacity of the autoclaved soil samples. These results suggest that microbial laccase is involved in iodide sorption on soils through the oxidation of iodide.

Determination of technetium by graphite furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Kaye, J.H.; Ballou, N.E.

1978-01-01

A detection limit of 6 x 10 -11 g has been achieved for measurement of technetium by graphite furnace atomic absorption spectrometry. A commercially available, demountable, hollow cathode lamp was used and both argon and neon were used as fill gases for the lamp. The range of applicability of the method, when the unresolved 2614.23 to 2615.87 A doublet is used for analysis, is from 60 pg to at least 3 ng of technetium per aliquot analyzed. 3 figures, 1 table

Study of ammonia synthesis using technetium catalysts

International Nuclear Information System (INIS)

Spitsyn, V.I.; Mikhajlenko, I.E.; Pokrovskaya, O.V.

1982-01-01

A study was made on catalytic properties of technetium in ammonia synthesis reaction. The preparation of technetium catalysts on ν-Al 2 O 3 , BaTiO 3 , BaO-ν-Al 2 O 3 substrates is described. The investigation of catalytic activity of catalysts was carried out at a pressure of 1 atm. in vertical reactor with volume rate of 15000 h - 1 in the temperature range of 350-425 deg. The amount of catalyst was 0.5-1 g, the volume- 0.5 ml, the size of granules- 2-3 mm. Rate constants of ammonia synthesis reaction were calculated. Seeming activation energies of the process have meanings wihtin the limits of 40-50 kcal/mol. It was shown that with increase in concentration of Tc on BaTiO 3 the catalytic activity rises in comparison with pure Tc. The reduction of catalytic activity with increase of metal content on Al 2 O 3 begins in the limits of 3.5-6.7% Tc/ν-Al 2 O 3 . The catalyst of 5.3% Tc/4.1% Ba/ν -Al 2 O 3 compound has the maximum activity. Technetium catalysts possess the stable catalytic activity and don't requre its reduction during several months

Colorimetric sensing of iodide based on triazole-acetamide functionalized gold nanoparticles

International Nuclear Information System (INIS)

Lee, I-Lin; Sung, Yi-Ming; Wu, Shu-Pao; Wu, Chien-Hou

2014-01-01

We have modified gold nanoparticles (AuNPs) with triazole acetamide to obtain a material for the sensitive and selective colorimetric determination of iodide. The functionalized AuNPs were prepared by a reductive single chemical step using a Cu(I)-catalyzed click reaction. The presence of iodide ions induces the aggregation of these AuNPs and results in a color change from wine-red to purple. The iodide-induced aggregation can be detected visually with bare eyes, but also by photometry. The detection limit is as low as 15 nM. The method displays excellent selectivity for iodide over other anions due to the selective interaction with the amido groups of the triazole. The method was applied to the determination of iodide in spiked lake waters. (author)

Gentc99m, computational system for the technetium-99m generator

International Nuclear Information System (INIS)

Suparman, I.

1997-01-01

The technetium-99m generator is one of the main products of the PPR, as the continuity of the technetium-99m generator production is important for supporting the development of nuclear medicine. GENTC99M has been made for computational for the technetium-99m generator and includes data processing, documentation and information GENTC99M is also very useful in quality control application especially for the determinations of yield and radionuclidic impurities which consume much time. microsoft visual basic for MS-DOS and visual basic for windows have been used for making GENTC99M. Microsoft visual basic has several features that make it an ideal development language for both MS-DOS and Microsoft Windows. These features not only increase productivity, they also provide all the tools and hooks needed to develop some very sophisticated applications. for a production centre like PPR, GENTC99M is very useful to support the data processing, documentation and information system of the technetium-99m generator and it can also be modified for other products

Development of w/o microemulsion for transdermal delivery of iodide ions.

Science.gov (United States)

Lou, Hao; Qiu, Ni; Crill, Catherine; Helms, Richard; Almoazen, Hassan

2013-03-01

The objective of this study was to develop a water-in-oil (w/o) microemulsion which can be utilized as a transdermal delivery for iodide ions. Several w/o microemulsion formulations were prepared utilizing Span 20, ethanol, Capryol 90®, and water. The selected formulations had 5%, 10%, 15%, 20%, and a maximum of 23% w/w water content. Potassium iodide (KI) was incorporated in all formulations at 5% w/v. Physicochemical characterizations were conducted to evaluate the structure and stability. These studies included: mean droplet size, pH, viscosity, conductivity, and chemical stability tests. In vitro human skin permeation studies were conducted to evaluate the diffusion of the iodide ion through human skin. The w/o microemulsion formulations were stable and compatible with iodide ions with water content ranging from 5% to 23% w/w. The addition of KI influenced the physicochemical properties of microemulsion as compared to blank microemulsion formulations. In vitro human skin permeation studies indicated that selected formulations improved iodide ion diffusion significantly as compared to control (KI solution; P valuemicroemulsion. Span 20, ethanol and Capryol 90 protected the iodide ions against oxidation and formed a stable microemulsion. It is worth to note that according to Hofmeister series, iodide ions tend to lower the interfacial tension between water and oil and consequently enhance overall stability. This work illustrates that microemulsion system can be utilized as a vehicle for the transdermal administration of iodide.

Speciation and Oxidative Stability of Alkaline Soluble, Non-Pertechnetate Technetium

Energy Technology Data Exchange (ETDEWEB)

Levitskaia, Tatiana G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rapko, Brian M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Amity [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Peterson, James M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chatterjee, Sayandev [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walter, Eric D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cho, Herman M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Washton, Nancy M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-30

The long half-life, complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes, and high mobility in subsurface environments make technetium (Tc) one of the most difficult contaminants to dispose of and/or remediate. Technetium exists predominantly in the liquid tank waste phase as the relatively mobile form of pertechnetate, TcO₄^-. However, based on experimentation to date a significant fraction of the soluble Tc cannot be effectively separated from the wastes and may be present as a non- pertechnetate species. The presence of a non-pertechnetate species significantly complicates disposition of low-activity waste (LAW), and the development of methods to either convert them to pertechnetate or to separate directly is needed. The challenge is the uncertainty regarding the chemical form of the alkaline-soluble low-valent non-pertechnetate species in the liquid tank waste. This report summarizes work done in fiscal year (FY) 2014 exploring the chemistry of a low-valence technetium(I) species, [(CO)₃Tc(H₂O)₃]⁺, a compound of interest due to its implication in the speciation of alkaline-soluble technetium in several Hanford tank waste supernatants.

Radiolytic formation of organic iodides from organic compounds released from ripolin paint

International Nuclear Information System (INIS)

Attia, S.; Evans, G.J.

2002-01-01

The impact of a serious nuclear reactor accident is governed to a large extent by the possible release of airborne organic iodides to the environment. This research examines the identification and behavior of organic iodides formed in the containment due to the release of organic compounds from Ripolin paint, into the aqueous phase, following a nuclear reactor accident. A bench scale apparatus installed in the irradiation chamber of a Gammacell was used to analyze the formation of organic iodides. Iodo-organics, transferred to the gas phase above irradiated aqueous samples, were analyzed using a Thermal Desorption method coupled with gas chromatography and mass spectrometry. Detailed studies of the identity of the organic compounds released and the organic iodides formed were conducted. The effects of parameters such as irradiation dose were also examined. All the organic iodides formed, under radiolytic conditions, were identified as iodo-alkanes. The organic compounds that were released from the Ripolin paint, such as methyl isobutyl ketone, were found to decompose, by a series of reactions, to produce the organic iodides. The precursor organic compounds and the organic iodides formed were observed to consist of the same alkyl group. These results indicate that organic compounds released from surface paints directly influence the formation of radiolytic organic iodide. (author)

Parametric Study on the Organic Iodide Behavior during a Severe Accident

International Nuclear Information System (INIS)

Ryu, Myung Hyun; Kim, Han Chul; Kim, Do Sam

2011-01-01

Iodine is a major contributor to the potential health risk for the public following a severe accident from a nuclear power plant. Most of metal-iodides, the major form of iodine that enters the containment, can be readily dissolved in the sump water and result in iodide ions. These will be oxidized to form volatile I 2 through a large number of reactions such as radiolysis and hydrolysis. The organic radicals, made from organics such as paint in the sump water, react with iodine to produce organic iodides. Volatile iodine moves from the sump water to the atmosphere mainly by diffusion and natural convection, and react with surfaces and air radiolysis products (ARPs). Painted surfaces act as a sink for I 2 and as a source for organic iodides through adsorption and desorption. ARPs react with I 2 to form iodine oxides, which leads to the decrease of I 2 and organic iodides. Among the large number of iodine species, organic iodides have been extensively studied recently due to their volatility and very low retention. Qualified tools for modeling these phenomena have been developed and validated by several experiments such as EPICUR, PARIS and OECD-BIP. While mechanistic codes model a large number of reactions and species, semiempirical codes such as IODE or IMOD treat major ones. KINS developed a simple iodine model, RAIM (Radio-active iodine chemistry model), based on the IMOD methodology in order to deal with organic iodides conveniently, coupling with an integrated severe-accident analysis code. There are a number of mechanisms that affect the behavior of organic iodides. In this study, effects of pH of the aqueous phase, temperature, radiation dose rate, surface area of organic paints, initial iodine loads that are known to be important to organic iodide formation were studied analytically with RAIM, and also theoretically

Parametric Study on the Organic Iodide Behavior during a Severe Accident

Energy Technology Data Exchange (ETDEWEB)

Ryu, Myung Hyun; Kim, Han Chul; Kim, Do Sam [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2011-10-15

Iodine is a major contributor to the potential health risk for the public following a severe accident from a nuclear power plant. Most of metal-iodides, the major form of iodine that enters the containment, can be readily dissolved in the sump water and result in iodide ions. These will be oxidized to form volatile I{sub 2} through a large number of reactions such as radiolysis and hydrolysis. The organic radicals, made from organics such as paint in the sump water, react with iodine to produce organic iodides. Volatile iodine moves from the sump water to the atmosphere mainly by diffusion and natural convection, and react with surfaces and air radiolysis products (ARPs). Painted surfaces act as a sink for I{sub 2} and as a source for organic iodides through adsorption and desorption. ARPs react with I{sub 2} to form iodine oxides, which leads to the decrease of I{sub 2} and organic iodides. Among the large number of iodine species, organic iodides have been extensively studied recently due to their volatility and very low retention. Qualified tools for modeling these phenomena have been developed and validated by several experiments such as EPICUR, PARIS and OECD-BIP. While mechanistic codes model a large number of reactions and species, semiempirical codes such as IODE or IMOD treat major ones. KINS developed a simple iodine model, RAIM (Radio-active iodine chemistry model), based on the IMOD methodology in order to deal with organic iodides conveniently, coupling with an integrated severe-accident analysis code. There are a number of mechanisms that affect the behavior of organic iodides. In this study, effects of pH of the aqueous phase, temperature, radiation dose rate, surface area of organic paints, initial iodine loads that are known to be important to organic iodide formation were studied analytically with RAIM, and also theoretically

Technetium behaviour in Boom Clay - a laboratory and field study

Energy Technology Data Exchange (ETDEWEB)

Baston, G.M.N.; Ilett, D.J.; Cowper, M.M.; Pilkington, N.J.; Tweed, C.J.; Williams, S.J. [AEA Technology plc, Harwell, Didcot, Oxfordshire (United Kingdom); Canniere, P.R. de; Wang, L. [SCK.CEN, Waste and Disposal Project, Boeretang, Mol (Belgium)

2002-07-01

This paper describes a study of technetium solubility and migration under chemical conditions representative of those prevailing in a Boom Clay environment. Laboratory and in situ measurements yielded similar aqueous concentrations of technetium, of about 1 x 10{sup -8} mol dm{sup -3}, close to the concentrations measured for hydrated technetium(IV) oxide TcO{sub 2}.1.6H{sub 2}O in the solubility studies. From fitting the curves of the Tc concentrations as function of time, distribution coefficient (K{sub d}) values were estimated to lie between 0.8 cm{sup 3} g{sup -1} and 1.8 cm{sup 3} g{sup -1}. Exposure of the system at 80 C and to {gamma}-radiation dose rates of several hundred Gy h{sup -1} resulted in only minor differences in behaviour. (orig.)

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)

Study of reduction and complexation of technetium in the presence of humate

International Nuclear Information System (INIS)

Tkac, P.

2003-06-01

Reduction of pertechnetate was studied by different reduction systems: Sn 2+ , Fe 2+ , ascorbic acid, mixture of ascorbic acid and Fe 3+ , and thiourea. Reduction of pertechnetate by Sn 2+ ions (5 · 10 -2 - 5 · 10 -7 mol.dm -3 ) was studied in pH range of 0.94-6.4. For effective reduction of Tc(VII) an acidic environment (pH 2+ ions higher than 1 · 10 -5 mol.dm-3 was necessary. Reduction of Tc(VII) by Fe 2+ (0.01 mol.dm -3 FeSO 4 ) was strongly dependent on pH and for reduction yield higher than 95 %, pH = 8 and higher was needed. In the presence of ascorbic acid (1 - 5 %) no significant reduction was observed. When a 5 % solution of ascorbic acid was prepared by dilution of ascorbic acid in 2 mol.dm -3 HCl, 60 % reduction after 30 minutes of reaction was observed. Reduction of Tc(VII) in the presence of ascorbic acid was most effectively observed in the presence of Fe 3+ ions. The yield of reduction was about 98 % after 20 minutes of reaction. Reduction of pertechnetate by thiourea was studied in acidic solution (HCl). Different conditions were used for reduction of 99m TcO 4 - and 99 TcO 4 - , respectively. The best yield for a routine preparation of [ 99 Tc(tu) 6 ] 3+ (tu = thiourea) was observed when 70 mg of thiourea was dissolved in 5 ml of 0.5 mol.dm -3 HCl and 0.2 - 0.5 ml of 6 · 10 -2 mol.dm -3 TcO 4 - was added. The mixture was allowed to react at least 20 hours. In the case of 99m Tc, 35 mg of thiourea was diluted in 5 ml of 2 mol.dm -3 HCl and 0.1 - 0.5 ml of pertechnetate generator solution was added. Reaction mixture was heated at 100 grad C for at least 30 minutes under nitrogen atmosphere. The yield of pertechnetate reduction for both preparation methods was about 99 %. The thiourea complex of technetium was chosen for preparation of technetium-humic complex, because it is well known as the most suitable precursor for preparation of new technetium complexes with Tc 3+ . Gel chromatography of natrium humate was carried out before preparation of

Coordination chemistry of technetium as related to nuclear medicine

International Nuclear Information System (INIS)

Srivastava, S.C.; Richards, P.

1982-01-01

Significant advances have been made in the area of technetium coordination chemistry during the last five years. The main driving force behind this recent surge of interest in the field has been due to the practical application of technetium-99m in the rapidly growing speciality of nuclear medicine. Technetium-99 is one of the products of nuclear fission reactions, but it was the development of the molybdenum-99-technetium-99m generator about two decades ago that provided the basis for the development of radiopharmaceuticals routinely used in modern diagnostic applications. The chemistry of this element has proven to be quite rich owing to its multiple oxidation states and variable geometry. This can be attributed to its position in the middle of the periodic table. Diagnostic radiopharmaceuticals comprise predominantly III, IV and V oxidation states of Tc and involve a variety of coordination complexes. Even though the chemistry of Tc has been slow to evolve, recent synthetic advances have provided a more scientific basis for the study of a number of compounds with diverse coordination geometries and structures. Ligands with oxygen, nitrogen and sulfur donor atoms have been utilized to elucidate various aspects of the coordination chemistry of Tc. Single crystal X-ray structural analysis has been extensively used to characterize Tc complexes and thus construct a firm foundation for the study of synthetic and mechanistic aspects of the chemistry of this element. (author)

Investigation of the interaction of hydroxyapatite with technetium in association with stannous pyrophosphate

International Nuclear Information System (INIS)

Billinghurst, M.W.; Jette, D.; Somers, E.

1981-01-01

The individual components of technetium-99m stannous pyrophosphate were studied with respect to their interaction with hydroxyapatite. It is demonstrated that the role of the pyrophosphate molecule is one of a solubilizing and transporting molecule to carry the technetium atom to the site of the hydroxyapatite where the chelate disassociates and both the pyrophosphate and the technetium individually bind to the hydroxyapatite. The stannous ion is shown to associate with the hydroxyapatite also and although also solubilized by the pyrophosphate appears to be less strongly associated with the pyrophosphate. (author)

Behavior of technetium in nuclear waste vitrification processes.

Science.gov (United States)

Pegg, Ian L

Nearly 100 tests were performed with prototypical melters and off-gas system components to investigate the extents to which technetium is incorporated into the glass melt, partitioned to the off-gas stream, and captured by the off-gas treatment system components during waste vitrification. The tests employed several simulants, spiked with 99m Tc and Re (a potential surrogate), of the low activity waste separated from nuclear wastes in storage in the Hanford tanks, which is planned for immobilization in borosilicate glass. Single-pass technetium retention averaged about 35 % and increased significantly with recycle of the off-gas treatment fluids. The fraction escaping the recycle loop was very small.

Analysis of Technetium Species and Fractions in Natural Seaweed Using Biochemical Separation and ICP-MS Measurement

DEFF Research Database (Denmark)

Shi, Keliang; Hou, Xiaolin; Qiao, Jixin

2016-01-01

An extremely high accumulation and retention of technetium in marine plants, especially brown seaweed, makes it a unique bioindicator of technetium. In the present work, a novel approach was developed for the speciation analysis of technetium in seaweed, wherein a series of biochemical separations....... Besides the inorganic species of TcO4-, most of technetium (>75%) combined with organic components of seaweed such as algin, cellulose, and pigment. This investigation could provide important fundamental knowledge for studying the processes and mechanisms of 99Tc accumulation in the natural seaweed....

Technetium-99 m generator safety simulation

International Nuclear Information System (INIS)

Kang, Sang Koo; Kim, Chong Yeal

2008-01-01

Technetium ( 99m Tc) is one of the most widely used radioactive isotopes for diagnosis in the world. In general, 99m Tc is produced inside the so called technetium generator where 99Mo decays to 99m Tc. And the generator is usually made out of lead to shield relatively high energy radiation from 99m Tc and 99 Mo. In this paper, a GEANT4 simulation is carried out to test the safety of the 99m Tc generators, taking domestic and Japanese products with radioactivity of 18.50 GBq (500 mCi) for example. According to the domestic regulation on radiation safety, the dose at 10 cm and 100 cm away from the surface of radiation shielder should not exceed 2 mSv∙h -1 and 0.02 mSv∙h -1 , respectively. The simulated dose turned out about only 10% of the limit, satisfying the domestic regulation

Thyroid iodide compartments and their implication in the rat thyroid iodine organification

International Nuclear Information System (INIS)

Bastiani, P.; Simon, C.

1982-01-01

To estimate the relative participation of transported and intrathyroidally generated iodide (internal iodide) in the iodination of newly synthesized and preexisting thyroglobulin (Tg) in the rat thyroid, the specific radioactivities (SRAs) of thyroid iodide, Tg, lysosomal iodine, and plasma hormones were followed for 92 h after radioactive iodide injection in intact or hypophysectomized rats. In control rats, the SRA of Tg and lysosomal iodine reached a maximum at 12 h. However, the SRA of lysosomal iodide was always smaller than that of Tg. In contrast, the SRA of hormonal iodide attained a maximum at 48 h. Thus, newly labeled iodine is endocytosed and mixed inside the lysosomes with older previously iodinated molecules; hormone secretion is mainly due to old labeled iodine (i.e. iodine with a high SRA from 48-96 h). These results are consistent with the presence of least two Tg compartments, with different turnover rates and hormone contents. On the other hand, in hypophysectomized rats, the SRA of Tg, lysosomes, and hormones showed only one maximum, at 24 h. Furthermore, the SRAs of Tg and lysosomes were similar at each time interval. It is inferred that in such rats, the old labeled iodine compartment is strongly reduced, and that inside the lysosomes, newly labeled iodine is predominant. Since in hypophysectomized rats, the recycling of iodide is abolished, it is concluded that in normal rats: 1) transported iodide is organified mainly by direct iodination of newly synthesized Tg, independently of TSH, and 2) internal iodide is organified mainly by delayed iodination of preexisting Tg, this process being TSH dependent

Study on gold concentrate leaching by iodine-iodide

Science.gov (United States)

Wang, Hai-xia; Sun, Chun-bao; Li, Shao-ying; Fu, Ping-feng; Song, Yu-guo; Li, Liang; Xie, Wen-qing

2013-04-01

Gold extraction by iodine-iodide solution is an effective and environment-friendly method. In this study, the method using iodine-iodide for gold leaching is proved feasible through thermodynamic calculation. At the same time, experiments on flotation gold concentrates were carried out and encouraging results were obtained. Through optimizing the technological conditions, the attained high gold leaching rate is more than 85%. The optimum process conditions at 25°C are shown as follows: the initial iodine concentration is 1.0%, the iodine-to-iodide mole ratio is 1:8, the solution pH value is 7, the liquid-to-solid mass ratio is 4:1, the leaching time is 4 h, the stirring intensity is 200 r/mim, and the hydrogen peroxide consumption is 1%.

Standard free energy of formation of iron iodide

Science.gov (United States)

Khandkar, A.; Tare, V. B.; Wagner, J. B., Jr.

1983-01-01

An experiment is reported where silver iodide is used to determine the standard free energy of formation of iron iodide. By using silver iodide as a solid electrolyte, a galvanic cell, Ag/AgI/Fe-FeI2, is formulated. The standard free energy of formation of AgI is known, and hence it is possible to estimate the standard free energy of formation of FeI2 by measuring the open-circuit emf of the above cell as a function of temperature. The free standard energy of formation of FeI2 determined by this method is -38784 + 24.165T cal/mol. It is estimated that the maximum error associated with this method is plus or minus 2500 cal/mol.

Non-Pertechnetate Technetium Sensor Research and Development

Energy Technology Data Exchange (ETDEWEB)

Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Crawford, Amanda D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heineman, William R. [Univ. of Cincinnati, OH (United States); Rapko, Brian M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Branch, Shirmir D. [Univ. of Cincinnati, OH (United States)

2014-09-01

There remain several significant uncertainties in the understanding and modeling of the fate and speciation of ⁹⁹Tc in Hanford waste tanks, glass, and low-temperature waste forms. A significant (2% to 25%) fraction of the ⁹⁹Tc in the water-soluble portion of the tank waste may be present as a non-pertechnetate species that has not been identified and, based on experimentation to date, cannot be effectively separated from the wastes. This task will provide a sensor specifically tuned to detect the Tc(I)-carbonyl species believed to constitute the main fraction of the non-pertechnetate form of technetium. By direct measurement of the non-pertechnetate species, such a sensor will help reduce the uncertainties in the modeling of the fate and speciation of ⁹⁹Tc in Hanford tanks and waste forms. This report summarizes work done in FY 2014 exploring the chemistry of a low-valence technetium species, [Tc(CO)₃(H₂O)₃]⁺, a compound of interest due to its implication in the speciation of alkaline-soluble technetium in several Hanford tank waste supernatants. Progress made in FY 2014 was sponsored by the Department of Energy’s Office of Environmental Management and is summarized in this report.

Determination of Technetium-99 in Environmental Samples by Solvent Extraction at Controlled Valence

DEFF Research Database (Denmark)

Chen, Q.J.; Aarkrog, A.; Dahlgaard, H.

1989-01-01

Distribution coefficients of technetium and ruthenium are determined under different conditions with CCl4, cyclohexanone, and 5% tri-isooctylamine (TIOA)/xylene. A method for analyzing 99Tc in environmental samples has been developed by solvent extraction in which the valences of technetium...

Behavior of radioactive organic iodide in an atmosphere of High Temperature Gas-cooled Reactor

International Nuclear Information System (INIS)

Saeki, Masakatsu; Nakashima, Mikio; Sagawa, Chiaki; Masaki, Nobuyuki; Hirabayashi, Takakuni; Aratono, Yasuyuki

1990-06-01

Formation and decomposition behavior of radioactive organic iodide have been studied in an atmosphere of High Temperature Gas-cooled Reactor (High Temperature Engineering Test Reactor, HTTR). Na 125 I was chosen for radioactive iodine source instead of CsI diffusing from coated fuel particles. Na 125 I adsorbed on graphite was heated in pure He and He containing O 2 or H 2 O atmosphere. The results obtained are as follows. It was proved that organic iodide was formed with organic radicals released from graphite even in He atmosphere. Thus, the interchange rate of inorganic iodide with organic iodide was remarkably decreased with prolonged preheat-treatment period at 1000degC. Organic iodide formed was easily decomposed by its recirculation into hot reaction tube kept at 900degC. When organic iodide was passed through powdered graphite bed, more than 70% was decomposed at 90degC. Oxygen and water vapour intermixed in He suppressed the interchange rate of inorganic iodide with organic iodide. These results suggest that organic iodide rarely exists in the pressure vessel under normal operating condition of HTTR, and, under hypothetical accident condition of HTTR, organic iodide fraction never exceeds the value used for a safety assessment of light water reactor. (author)

Separation, Concentration, and Immobilization of Technetium and Iodine from Alkaline Supernate Waste

Energy Technology Data Exchange (ETDEWEB)

James Harvey; Michael Gula

1998-12-07

Development of remediation technologies for the characterization, retrieval, treatment, concentration, and final disposal of radioactive and chemical tank waste stored within the Department of Energy (DOE) complex represents an enormous scientific and technological challenge. A combined total of over 90 million gallons of high-level waste (HLW) and low-level waste (LLW) are stored in 335 underground storage tanks at four different DOE sites. Roughly 98% of this waste is highly alkaline in nature and contains high concentrations of nitrate and nitrite salts along with lesser concentrations of other salts. The primary waste forms are sludge, saltcake, and liquid supernatant with the bulk of the radioactivity contained in the sludge, making it the largest source of HLW. The saltcake (liquid waste with most of the water removed) and liquid supernatant consist mainly of sodium nitrate and sodium hydroxide salts. The main radioactive constituent in the alkaline supernatant is cesium-137, but strontium-90, technetium-99, and transuranic nuclides are also present in varying concentrations. Reduction of the radioactivity below Nuclear Regulatory Commission (NRC) limits would allow the bulk of the waste to be disposed of as LLW. Because of the long half-life of technetium-99 (2.1 x 10 5 y) and the mobility of the pertechnetate ion (TcO 4 - ) in the environment, it is expected that technetium will have to be removed from the Hanford wastes prior to disposal as LLW. Also, for some of the wastes, some level of technetium removal will be required to meet LLW criteria for radioactive content. Therefore, DOE has identified a need to develop technologies for the separation and concentration of technetium-99 from LLW streams. Eichrom has responded to this DOE-identified need by demonstrating a complete flowsheet for the separation, concentration, and immobilization of technetium (and iodine) from alkaline supernatant waste.

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

Experimental studies on the uptake of technetium-99 to terrestrial crops

Energy Technology Data Exchange (ETDEWEB)

Brown, Joanne; Ewers, Leon [Centre for Radiation, Chemical and Environmental Hazards, Public Health England (United Kingdom)

2014-07-01

Technetium-99 has been dispersed in the environment from many sources such as nuclear weapons testing, releases from medical or industrial processes, nuclear power plants and nuclear fuel processing facilities. The pertechnetate ion, {sup 99}TcO{sub 4}{sup -} is the form produced during the nuclear fuel cycle and the most likely to be released into the environment. A recent review published by Public Health England (formerly the Health Protection Agency) found that the availability for the root uptake of technetium into crops depends on whether the technetium is in a chemically non-reduced more plant available form, such as TcO{sub 4}{sup -} or a chemically reduced less plant available form, such as TcO{sub 2}. Based on the review, generic soil to crop transfer factor (TF) values for use in non-site specific UK based radiological assessments were proposed, with the TF value for the reduced form of technetium in crops around a factor of 10 lower than that for the non-reduced form. The implications of the use of different TF values on the activity concentrations in crops and animal products predicted by PHE's food chain model, FARMLAND, for both routine and accidental release situations were explored. Recommendations on the best choice of TF values for use in the model have been given for a range of contamination scenarios. A small scale experimental study has been carried out to provide further evidence that the generic assumption made on the difference between soil-crop TF values for non-reduced and reduced forms of technetium is valid. The study was also designed to establish likely time periods over which the chemical reduction of technetium takes place and to provide additional soil-crop TF values for use in UK based radiological assessments. Soil to crop TFs for crops harvested from loam and peat soils up to 4 months after contamination are about a factor of 10 higher than those seen in soil contaminated more than a year previously, indicating that the

Transmutation of technetium into stable ruthenium in high flux conceptual research reactor

International Nuclear Information System (INIS)

Amrani, N.; Boucenna, A.

2007-01-01

The effectiveness of transmutation for the long lived fission product technetium-99 in high flux research reactor, considering its large capture cross section in thermal and epithermal region is evaluated. The calculation of Ruthenium concentration evolution under irradiation was performed using Chain Solver 2.20 code. The approximation used for the transmutation calculation is the assumption that the influence of change in irradiated materials structures on the reactor operator mode characteristics is insignificant. The results on Technetium transmutation in high flux research reactor suggested an effective use of this kind of research reactors. The evaluation brings a new concept of multi-recycle Technetium transmutation using HFR T RAN (High Flux Research Reactor for Transmutation)

Technetium 99-m labeled radio-diagnostic agents employing stannous tartrate and method of preparation

International Nuclear Information System (INIS)

Molinski, V.J.; Wilczewski, J.A.

1976-01-01

A method of preparing improved technetium-99m labeled radiodiagnostic agents by reducing technetium-99m with stannous tartrate. Such radiodiagnostic agents are useful in scintigraphic examinations of the bone and lung. 31 claims, no drawings

The radiochemical purity of technetium-99m-tin-diethylene-triamino-pentaacetic acid (DTPA) complex

International Nuclear Information System (INIS)

Besnard, M.; Costerousse, O.; Merlin, L.; Coehn, Y.

1975-01-01

The effect on radiochemical purity was studied as a function of the storage period of tin-DTPA solution and of the technetium-complex solution. The quantity of the pertechnetate ions present in the solution is determined by ascending paper chromatography, and an attempt was made to clarify the bond type of technetium by a spectrophotometric method. The tin-DTPA solutions for complexing of the reduced technetium are stable over a period of 8 weeks. The yield of the radiopharmaceutical product is better than 95%. (G.Gy.)

Preparation of a generator of technetium-99m

International Nuclear Information System (INIS)

Jimeno de Osso, F.

1981-01-01

Practical description is given of equipment and operations necessary in the preparation of an isotopic generator of technetium-99m. The preparation and application of the active solution and throughly washed of the chromatographic column have been studied in order to allow molibdenum-99 to be adsorbed on a small band, and the solution of tectium-99m to be eluted with high efficiency and purity. The equipment and accesories used are easy and safety to manage, simplifying operations to be carried out with the active product, eliminating the sterile environment in the shielded cell, and facilitating the preparation of the solution of technetium-99m in sterile and pyrogen-free conditions.(author) [es

Determination of nanogram amounts of iodide by electrochemical isotope dilution analysis

International Nuclear Information System (INIS)

Gabrielsson, A.-B.; Beronius, P.

1976-01-01

A known quantity of iodide in ethanol as solvent was labelled with 131 I-and subsequently diluted with a predetermined amount of inactive iodide. Specific activities before and after the isotope dilution were established by anodically depositing small fractions of the halide in each sample on rotating silver micro electrodes and determining the activities of the electrodeposits. The lowest concentration of iodide used in any analysis was 1.10 -5 M. Further deposition studies revealed that iodide can be deposited with 1 100% current efficiency on the rotating silver micro electrode for concentration down to 2.4.10 -6 M. Electrodeposition studies for still lower concentrations have not yet been undertaken. These results suggest that amounts of iodide ion down to about 10 ng, and possibly still smaller quantitites, might be determined with the method developed. Amounts from 42 ng to 1 μg can be determined with an error of 2.5%. (T.G.)

Method to remove methyl iodide131 gas

International Nuclear Information System (INIS)

Deitz, V.R.; Blachly, C.H.

1977-01-01

A two-stage impregnation process for charcoal is presented which is to be used for radioactive iodine or methyl iodide removal from the waste gas of a nuclear reactor. In the first stage, the coal is treated at pH 10 with an aqueous mixture of a salt of iodic acid (hypoiodite, iodate, or periodate) with iodine or iodide. In the second stage, impregnation with a tertiary amine occurs. The concentrations are chosen so that the charcoal will take up between 0.5 and 4% by weight of iodine. (UWI) [de

A glucose bio-battery prototype based on a GDH/poly(methylene blue) bioanode and a graphite cathode with an iodide/tri-iodide redox couple.

Science.gov (United States)

Wang, Jen-Yuan; Nien, Po-Chin; Chen, Chien-Hsiao; Chen, Lin-Chi; Ho, Kuo-Chuan

2012-07-01

A glucose bio-battery prototype independent of oxygen is proposed based on a glucose dehydrogenase (GDH) bioanode and a graphite cathode with an iodide/tri-iodide redox couple. At the bioanode, a NADH electrocatalyst, poly(methylene blue) (PMB), which can be easily grown on the electrode (screen-printed carbon paste electrode, SPCE) by electrodeposition, is harnessed and engineered. We find that carboxylated multi-walled carbon nanotubes (MWCNTs) are capable of significantly increasing the deposition amount of PMB and thus enhancing the PMB's electrocatalysis of NADH oxidation and the glucose bio-battery's performance. The choice of the iodide/tri-iodide redox couple eliminates the dependence of oxygen for this bio-battery, thus enabling the bio-battery with a constant current-output feature similar to that of the solar cells. The present glucose bio-battery prototype can attain a maximum power density of 2.4 μW/cm(2) at 25 °C. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

The iodine/iodide redox couple at a platinum electrode

NARCIS (Netherlands)

Dane, L.M.; Janssen, L.J.J.; Hoogland, J.G.

1968-01-01

The I/iodide redox couple was studied on Pt in 0.5M H2SO4 by measuring the impedance as a function of frequency. From these measurements, the exchange c.d. j0 was derived according to Sluyters. The dependence of j0 on the reversible potential and the I and the iodide concns. was established. By

Effect of humic acid on sorption of technetium by alumina

International Nuclear Information System (INIS)

Kumar, S.; Rawat, N.; Kar, A.S.; Tomar, B.S.; Manchanda, V.K.

2011-01-01

Highlights: → Tc sorption on alumina has been studied under aerobic as well anaerobic condition over pH 3-10. → Effect of humic acid on sorption of Tc by alumina has been investigated. → Linear additive modeling and surface complexation modeling were carried out to delineate the role of humic acid in Tc(IV) sorption in ternary system of Tc(IV)-humic acid-alumina. → Sorption of humic acid onto alumina and strong complexation of Tc(IV) with humic acid were found to govern the sorption of Tc(IV) in the ternary system. - Abstract: Sorption of technetium by alumina has been studied in absence as well as in presence of humic acid using 95 Tc m as a tracer. Measurements were carried out at fixed ionic strength (0.1 M NaClO 4 ) under varying pH (3-10) as well as redox (aerobic and reducing anaerobic) conditions. Under aerobic conditions, negligible sorption of technetium was observed onto alumina both in absence and in presence of humic acid. However, under reducing conditions (simulated with [Sn(II)] = 10 -6 M), presence of humic acid enhanced the sorption of technetium in the low pH region significantly and decreased at higher pH with respect to that in absence of humic acid. Linear additive as well as surface complexation modeling of Tc(IV) sorption in presence of humic acid indicated the predominant role of sorbed humic acid in deciding technetium sorption onto alumina.

Auger recombination in sodium iodide

Science.gov (United States)

McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

2014-03-01

Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

Chemical form of technetium in corn (Zea mays) and the gastrointestinal absorption of plant-incorporated Tc by laboratory rats

Energy Technology Data Exchange (ETDEWEB)

Garten, C.T. Jr.; Myttenaere, C.; Vandecasteele, C.M.; Kirchmann, R.; Van Bruwaene, R.

1984-01-01

The food chain availability of technetium incorporated into plant tissue, its chemical form in corn leaves, and the potential for gastrointestinal absorption of plant-incorporated technetium was investigated. Technetium-95m was incorporated into corn leaves via root uptake. Chemical fractionation of the /sup 95m/Tc in leaves showed that 60% was extractable with boiling ethanol and weak mineral acids. The remainder was associated with cell walls and was extractable by harsh chemical treatment. Gel permeation chromatography of the cytosol, indicated that 50% of the /sup 95m/Tc co-chromatographed with anionic pertechnetate; however, it was impossible to distinguish if this pure pertechnetate or technetium complexed with organic molecules. Technetium-95m was administered to laboratory rats in a single dose as: (1) intravenous injection of pertechnetate, (2) pertechnetate mixed with standard laboratory food, and (3) a meal containing /sup 95m/Tc biologically incorporated into corn leaves. High concentrations of /sup 95m/Tc were found in the thyroids, hair, kidneys, and liver of rats. Technetium rapidly disappeared from the liver, kidneys, and other tissues, but remained in the thyroids and hair. Urinary excretion of technetium decreased, and fecal excretion increased when technetium was fed to rats as a /sup 95m/Tc incorporated into corn leaves. The percent of the administered dose absorbed into thyroid gland and the kidneys was less when technetium was biologically incorporated into corn leaves than when pertechnetate was mixed with food. Biological incorporation of technetium into plants appears to reduce its potential for food chain transfer by decreasing its availability for gastrointestinal absorption. 5 references, 4 figures, 3 tables.

Chemical form of technetium in corn (Zea mays) and the gastrointestinal absorption of plant-incorporated Tc by laboratory rats

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Myttenaere, C.; Vandecasteele, C.M.; Kirchmann, R.; Van Bruwaene, R.

1984-01-01

The food chain availability of technetium incorporated into plant tissue, its chemical form in corn leaves, and the potential for gastrointestinal absorption of plant-incorporated technetium was investigated. Technetium-95m was incorporated into corn leaves via root uptake. Chemical fractionation of the /sup 95m/Tc in leaves showed that 60% was extractable with boiling ethanol and weak mineral acids. The remainder was associated with cell walls and was extractable by harsh chemical treatment. Gel permeation chromatography of the cytosol, indicated that 50% of the /sup 95m/Tc co-chromatographed with anionic pertechnetate; however, it was impossible to distinguish if this pure pertechnetate or technetium complexed with organic molecules. Technetium-95m was administered to laboratory rats in a single dose as: (1) intravenous injection of pertechnetate, (2) pertechnetate mixed with standard laboratory food, and (3) a meal containing /sup 95m/Tc biologically incorporated into corn leaves. High concentrations of /sup 95m/Tc were found in the thyroids, hair, kidneys, and liver of rats. Technetium rapidly disappeared from the liver, kidneys, and other tissues, but remained in the thyroids and hair. Urinary excretion of technetium decreased, and fecal excretion increased when technetium was fed to rats as a /sup 95m/Tc incorporated into corn leaves. The percent of the administered dose absorbed into thyroid gland and the kidneys was less when technetium was biologically incorporated into corn leaves than when pertechnetate was mixed with food. Biological incorporation of technetium into plants appears to reduce its potential for food chain transfer by decreasing its availability for gastrointestinal absorption. 5 references, 4 figures, 3 tables

Studies of selected transuranium and lanthanide tri-iodides under pressure using absorption spectrophotometry

International Nuclear Information System (INIS)

Haire, R.G.; Young, J.P.; Peterson, J.R.; Tennessee Univ., Knoxville; Benedict, U.

1987-01-01

The anhydrous tri-iodides of plutonium, americium and curium under pressure have been investigated using absorption spectrophotometry. These initial studies on plutonium and curium tri-iodides together with the published data for americium tri-iodide show that the rhombohedral form of these compounds (BiI 3 -type structure) can be converted to the orthorhombic form (PuBr 3 -type structure) by applying pressure at room temperature. Absorption spectrophotometry can often differentiate between two crystallographic forms of a material and has been used in the present high-pressure studies to monitor the effects of pressure on the tri-iodides. A complication in these studies of the tri-iodides is a significant shift of their absorption edges with pressure from the near UV to the visible spectral region. With curium tri-iodide this shift causes interference with the major f-f absorption peaks and precludes identification by absorption spectrophotometry of the high pressure phase of CmI 3 . (orig.)

A selective iodide ion sensor electrode based on functionalized ZnO nanotubes.

Science.gov (United States)

Ibupoto, Zafar Hussain; Khun, Kimleang; Willander, Magnus

2013-02-04

In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10-6 to 1 × 10-1 M) and excellent sensitivity of -62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10-7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

Directory of Open Access Journals (Sweden)

Magnus Willander

2013-02-01

Full Text Available In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M and excellent sensitivity of –62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10−7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

Evolution of technetium speciation in reducing grout

Energy Technology Data Exchange (ETDEWEB)

Lukens, Wayne W.; Bucher, Jerome J.; Shuh, David K.; Edelstein,Norman M.

2003-11-24

Cementitious waste forms (CWFs) are an important component of the strategy to immobilize high-level nuclear waste resulting from plutonium production by the U.S. Department of Energy (DOE). Technetium (99Tc) is an abundant fission product of particular concern in CWFs due to the high solubility and mobility of pertechnetate, TcO4-, the stable form of technetium in aerobic environments. CWFs can more effectively immobilize 99Tc if they contain additives that reduce mobile TcO4- to immobile Tc(IV) species. Leaching of 99Tc from reducing CWFs that contain Tc(IV) is much slower than for CWFs containing TcO4-. Previous X-ray absorption fine structure (XAFS) studies showed that the Tc(IV) species were oxidized to TcO4- in reducing grout samples prepared on a laboratory scale. Whether the oxidizer was atmospheric O2 or NO3- in the waste simulant was not determined. In actual CWFs, rapid oxidation of Tc(IV) by NO3- would be a concern, whereas oxidation by atmospheric O2 would be of less concern due to the slow diffusion and reaction of O2 with the reducing CWF. To address this uncertainty, two series of reducing grouts were prepared using TcO4- containing waste simulants with and without NO3-. In the first series of samples, the TcO4- was completely reduced using Na2S, and the samples were placed in containers that permitted O2 diffusion. In these samples, all of the technetium was initially present as aTc(IV) sulfide compound, TcSx, which was characterized using extended X-ray absorption fine structure (EXAFS) spectroscopy, and is likely Tc2S7. The TcSx initially present in the grout samples was steadily oxidized over 4 years. In the second series of samples, all of the TcO4- was not initially reduced, and the grout samples were placed in airtight containers. In these samples, the remaining TcO4- continued to be reduced as the samples aged, presumably due to the presence of reducing blast furnace slag. When samples in the second series were exposed to atmosphere, the

The iodide sym-porter (NIS): new perspectives in nuclear oncology

International Nuclear Information System (INIS)

Pourcher, Th.; Lindenthal, S.; Basquin, C.; Ferhat, O.; Marsault, R.; Carrier, P.; Koulibaly, M.; Bussiere, F.; Darcourt, J.

2005-01-01

The sodium iodide sym-porter (NIS) is the plasma membrane protein that mediates uptake of iodide in the thyroid and other organs such as the stomach and the salivary gland. The cloning of its cDNA allows the targeting of NIS expression into any cell using gene therapy. This enables iodide uptake and thus NIS can be used as reporter imaging for live animals. More intriguingly, this new technique has potential using radio-iodide therapy to selectively destroy tumour cells. These two approaches employ common techniques in nuclear medicine. Many experiments on cultured cells and on animals have been carried out; they established clearly the advantages of this genetically targeted radiotherapy. Recent studies employing this therapy on multiple myeloma cell lines implanted in mice or on hepato-carcinoma-bearing rats, resulted in important tumour remission. However, additional studies on NIS regulation and the use of alternative radioisotopes transported by NIS are required to further develop this promising approach. (author)

Sorption behaviour of radioactive technetium in soils

International Nuclear Information System (INIS)

Xia Deying

1996-01-01

The sorption behaviour of technetium in different soils has been studied by batch experiments under aerobic conditions. The soil samples have been taken to study the characteristics and to derive the pH-Eh values. In addition, the activated carbon and reduced iron powder have been selected as additives to the JAERI sand according to the former research work, so that the technetium sorption behaviour in the artificial soils can be studied under similar conditions. The experimental results show that all these soil samples except for the gluey soil have a very small distribution coefficient for Tc, while the artificial soils have a very large distribution coefficient for Tc. Besides, for artificial soils, the distribution coefficient (R d ) values will become larger and larger when more additive is added and more contact time is allowed. The physico-chemical fixation processes and possible sorption modes have been discussed as well

Technetium-labeled HM-PAO studies in patients with cerebrovascular disease

International Nuclear Information System (INIS)

Smith, F.W.; Sharp, P.F.; Gemmell, H.; Evans, N.T.; MacDonald, A.F.

1986-01-01

Technetium-labeled hexamethyl-propyleneamineoxime (HM-PAO) is a promising radiopharmaceutical for the demonstration of cerebral blood flow. Twenty-four patients who had experienced either acute stroke (AS) or transient ischemic attack (TIA) were studied by x-ray CT and SPECT using technetium-labeled HM-PAO total of 26 studies. HM-PAO has a cerebral distribution similar to that of iodoamphetamine, but labeling with technetium allows good SPECT imaging on demand in any nuclear medicine department. In ten of the 16 patients who had experienced AS, findings on HM-PAO and CT studies correlated well. In six patients reduced cortical perfusion was detected on HM-PAO imaging, but only small infarcts in the internal capsule were seen on CT. In four of the eight patients who had experienced TIA, neither study revealed any abnormality. In the remaining four, areas of cortical underperfusion were seen on HM-PAO imaging, whereas the CT examination was normal. The findings in this study suggest that HM-PAO imaging is a more sensitive method for demonstrating the extent of cerebral underperfusion in cases of cerebrovascular accident

Evaluating iodide recycling inhibition as a novel molecular initiating event for thyroid axis disruption

Science.gov (United States)

The enzyme iodotyrosine deiodinase (dehalogenase, IYD) catalyzes iodide recycling and promotes iodide retention in thyroid follicular cells. Loss of function or chemical inhibition of IYD reduces available iodide for thyroid hormone synthesis, which leads to hormone insufficiency...

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

International Nuclear Information System (INIS)

Sun, Zhuyu; Zhang, Chaojie; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-01-01

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k_1) of 0.60 ± 0.03 min"−"1. Hydrated electrons (e_a_q"−) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO_2"−) were formed as the main intermediate products, which completely converted to formate (HCOO"−), ammonium (NH_4"+) and nitrogen (N_2). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e_a_q"−. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO_2"−, thus effectively reducing the secondary pollution.

An investigation of the effect of the quantity of stannous ion on the quality of technetium-99m labelled albumin

International Nuclear Information System (INIS)

Billinghurst, M.W.; Rempel, S.; Westendorf, B.A.

1981-01-01

The importance of maintaining a low ratio of stannous ion to albumin molecules in order to obtain a high quality technetium-99m labelled albumin is demonstrated. It is further shown that the direct preparation of technetium-99m albumin by reduction of the technetium-99m pertechnetate with stannous ion inevitably leads to the contamination of the product with a certain amount of tin colloid which is also labelled with technetium-99m. It is demonstrated that this can be avoided by utilizing labelling techniques involving the initial formation of other technetium chelates which are less stable than the albumin complex under certain conditions, adding the albumin to that preparation, adjusting the conditions and thus allowing the albumin to become labelled with technetium-99m via an exchange with the original chelating agent. (author)

A method for the preparation of lipophilic macrocyclic technetium-99m complexes

International Nuclear Information System (INIS)

Troutner, D.E.; Volkert, W.A.

1991-01-01

A procedure for the preparation of technetium complexes applicable as diagnostic radiopharmaceuticals is suggested and documented with 27 examples. Technetium-99m is reacted with a suitable complexant selected from the class of alkylenamine oximes containing 2 or 3 carbon atoms in the alkylene group. The lipophilic macrocyclic complexes possess an amine, amide, carboxy, carboxy ester, hydroxy or alkoxy group or a suitable electron acceptor group. (M.D.). 7 tabs

Electro regeneration of iodide loaded resin. Contributed Paper RD-18

International Nuclear Information System (INIS)

Kumar, Ratnesh; Kumar, T.; Sree Kumar, B.; Seshadri, K.S.; Paul, Biplob

2014-01-01

Spent resins generated in the nuclear reactor contain essentially cationic activities due to Cesium, Strontium, Cobalt, and anionic activities due to Iodide, Iodate etc with activity loading to the extent of 0.1 Cim -3 and a surface dose of the order of 5 R. It is necessary to convert the spent resin into innocuous, reusable forms. An attempt has been made to regenerate Iodide containing spent resin into OH - electrolytically by using the OH - produced at the cathode compartment of an electrolytic cell. Results show that the regeneration of the spent resin containing Iodide could be completely accomplished electrolytically more efficiently than by addition of alkali. (author)

Measurement of glomerular filtration rate in children using technetium-99m diethylenetriamine penta-acetic acid

International Nuclear Information System (INIS)

Aaronson, I.A.; Mann, M.D.

1985-01-01

During the past 5 years, we have measured the glomerular filtration rate (GFR) by the slope-clearance method using technetium-99m diethylenetriamine penta-acetic acid technetium-99m-DTPA in 130 infants and children. The results in 22 children have been compared with inulin clearance, and a very good correlation between the two methods of measurement of GFR was demonstrated (r = 0,9616; P less than 0,0001). This study provides further evidence that technetium-99m-DTPA is a satisfactory agent for the clinical measurement of GFR in children

Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

Directory of Open Access Journals (Sweden)

Furlanetto T.W.

2001-01-01

Full Text Available Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 ± 0.370 to 2.085 ± 0.364 pmol I-/µg DNA at 1 ng/ml (P<0.02, to 1.970 ± 0.302 pmol I-/µg DNA at 10 ng/ml (P<0.003, and to 2.038 ± 0.389 pmol I-/µg DNA at 100 ng/ml (P<0.02. In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 ± 0.408 to 7.312 ± 0.506 pmol I-/µg DNA (P<0.02. A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.

Molybdenum and technetium cycle in the environment. Physical chemical evolution and mobility in soils and plants

International Nuclear Information System (INIS)

Saas, A.; Denardi, J.L.; Colle, C.; Quinault, J.M.

1980-01-01

Molybdenum 99 and technetium 99 from liquid discharges of base nuclear installations (reactors, reprocessing plants, UF 6 treatment, etc.) can reach the environment via irrigation waters and atmospheric deposits. The contribution to the soil by irrigation results in a physical-chemical transformation, the results of which, in the case of technetium 99, could be volatilization via microbes. The changes in the physical-chemical forms of technetium in different soils reveals the preponderant effect of the initial amount deposited. The determination of the rate of technetium and molybdenum assimilation shows a certain similarity in behaviour; yet the localization of these isotopes is not the same. The transfer of molybdenum and technetium via the root system is different in its intensity; this is mainly due to different physical-chemical forms. Finally, each isotope has an optimum assimilation threshold and a toxicity threshold. The study of the physical-chemical evolution and the mobility in the soil-plant-water table system of these two isotopes shows a new aspect with respect to certain transfer channels to the human being [fr

Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

International Nuclear Information System (INIS)

Gonzalez-Garcia, C.M.; Gonzalez, J.F.; Roman, S.

2011-01-01

Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

Study on interference of technetium in spectrophotometric estimation of uranium

International Nuclear Information System (INIS)

Revathi, P.; Saipriya, K.; Madhavan Kutty, V.K.; Srinivasa Rao, G.; Vijayakumar, N.; Kumar, T.

2015-01-01

Estimation of uranium is essential for process control purposes as well as to arrive optimum parameters for further waste management in reprocessing industry. Uranium estimation is done by spectrophotometry using ammonium thiocyanate, DBM, PAR and Br-PADAP as chromogenic reagents for colour development. Extractive spectrophotometry can also be used to eliminate some of the interfering ions. During inter method comparison, technetium was found to be interfering in the thiocyanate spectrophotometry. This study is an effort to find out the extent of technetium interference in the estimation of uranium by spectrophotometry using the above said chromogenic reagents. (author)

Performance testing of blast furnace slag for immobilization of technetium in grout

International Nuclear Information System (INIS)

Gilliam, T.M.; Spence, R.D.; Evans-Brown, B.S.; Morgan, I.L.; Shoemaker, J.L.; Bostick, W.D.

1988-01-01

This paper presents preliminary results of a grout development effort to identify grout formulas that can satisfactorily sequester 99 Tc contained in an existing Portsmouth Gaseous Diffusion Plant waste. Technetium is of particular concern to the US Nuclear Regulatory Commission (NRC) because of its mobility and biological activity. The mobility of technetium results in large part from the movement of the pertechnate anion [prevalent in low-level radioactive waste (LLW)] through soil and geologic strata with little or no interaction with the surrounding matrix. Ground blast furnace slag has been shown to improve the leach resistance of cement-based waste forms, particularly in regard to technetium. This improved performance has been attributed to fewer and smaller pores in the solidified slags (versus a neat cement paste) and to the reduction of the pertechnate ion to a less soluble form. 9 refs., 2 tabs

Obtention of scintillography images by low density lipoproteins labelled with technetium 99

International Nuclear Information System (INIS)

Silva, S.; Coelho, I.; Zanardo, E.; Pileggi, F.; Meneguethi, C.; Maranhao, R.C.

1992-01-01

The low density lipoproteins carry the most part of the cholesterol in the blood plasma. These lipoproteins are labelled with technetium-99-m and have been used for obtaining images in nuclear medicine. The introduction of this technique is presented, aiming futures clinical uses. Scintillographic images are obtained 25 minutes and 24 hours after the injection of 3 m Ci of low density lipoproteins - technetium-99 m in rabbits. (C.G.C.)

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhuyu; Zhang, Chaojie, E-mail: myrazh@tongji.edu.cn; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

2017-05-05

Highlights: • N-nitrosodimethylamine (NDMA) was effectively decomposed by UV/iodide process. • NDMA was completely converted to nontoxic end products by UV/iodide process. • The photoreductive process was mainly attributed to the attack of hydrated electrons on the photoexcited NDMA. • The elimination of toxic intermediates was greatly enhanced as pH increased, but its effect on NDMA removal was negligible. - Abstract: N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10 min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k{sub 1}) of 0.60 ± 0.03 min{sup −1}. Hydrated electrons (e{sub aq}{sup −}) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO{sub 2}{sup −}) were formed as the main intermediate products, which completely converted to formate (HCOO{sup −}), ammonium (NH{sub 4}{sup +}) and nitrogen (N{sub 2}). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of N−NO bond under the attack of e{sub aq}{sup −}. The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO{sub 2}{sup −}, thus effectively reducing the secondary pollution.

Technetium cyanide chemistry: synthesis and characterization of technetium(III) and -(V) cyanide complexes

International Nuclear Information System (INIS)

Trop, H.S.; Jones, A.G.; Davison, A.

1980-01-01

Several new technetium cyanide complexes have been prepared and characterized. The reaction of ammonium hexaiodotechnetate(IV) with potassium cyanide in refluxing aqueous methanol under nitrogen yields potassium heptacyanotechnetate(III) dihydrate, K 4 Tc(CN) 7 .2H 2 O (1). Infrared and Raman measurements indicate that 1 has a pentagonal bipyramidal structure (D/sub 5h/) in both solid and solution. Aqueous solutions of 1 are air sensitive, decomposing to potassium oxopentacyanotechnetate(V) tetrahydrate, K 2 TcO(CN) 5 .4H 2 O (2). This species can also be prepared from the reaction of TcO 2 .xH 2 O with hot aqueous potassium cyanide solutions. Hydrolysis of 2 in water yields potassium trans-dioxo-tetracyanotechnetate(V), K 3 TcO 2 (CN) 4 (3). Preparation of 3 can also be achieved from the treatment of [TcO 2 (Py) 4 ]ClO 4 .2H 2 O with aqueous potassium cyanide. Infrared and Raman measurements on 3 are consistent with the proposed trans-dioxo (D/sub 4h/) structure. Reaction of the oxotetrachlorotechnetate(V) anion, TcOCl 4 , with potassium cyanide in methanol produces trans-oxomethoxytetracyanotechnetate(V). [TcO(OMe)(CN) 4 ] (4). The full details of the synthesis and characterization of these interesting technetium(III) and -(V) complexes, as well as observations on the infrared and Raman spectra of trans-dioxo metal complexes and the hydrolysis of species 2, are presented

Oxygen-hydrogen fuel cell with an iodine-iodide cathode - A concept

Science.gov (United States)

Javet, P.

1970-01-01

Fuel cell uses a porous cathode through which is fed a solution of iodine in aqueous iodide solution, the anode is a hydrogen electrode. No activation polarization appears on the cathode because of the high exchange-current density of the iodine-iodide electrode.

Fluoridonitrosyl complexes of technetium(I) and technetium(II). Synthesis, characterization, reactions, and DFT calculations.

Science.gov (United States)

Balasekaran, Samundeeswari Mariappan; Spandl, Johann; Hagenbach, Adelheid; Köhler, Klaus; Drees, Markus; Abram, Ulrich

2014-05-19

A mixture of [Tc(NO)F5](2-) and [Tc(NO)(NH3)4F](+) is formed during the reaction of pertechnetate with acetohydroxamic acid (Haha) in aqueous HF. The blue pentafluoridonitrosyltechnetate(II) has been isolated in crystalline form as potassium and rubidium salts, while the orange-red ammine complex crystallizes as bifluoride or PF6(-) salts. Reactions of [Tc(NO)F5](2-) salts with HCl give the corresponding [Tc(NO)Cl4/5](-/2-) complexes, while reflux in neat pyridine (py) results in the formation of the technetium(I) cation [Tc(NO)(py)4F](+), which can be crystallized as hexafluoridophosphate. The same compound can be synthesized directly from pertechnetate, Haha, HF, and py or by a ligand-exchange procedure starting from [Tc(NO)(NH3)4F](HF2). The technetium(I) cation [Tc(NO)(NH3)4F](+) can be oxidized electrochemically or by the reaction with Ce(SO4)2 to give the corresponding Tc(II) compound [Tc(NO)(NH3)4F](2+). The fluorido ligand in [Tc(NO)(NH3)4F](+) can be replaced by CF3COO(-), leaving the "[Tc(NO)(NH3)4](2+) core" untouched. The experimental results are confirmed by density functional theory calculations on [Tc(NO)F5](2-), [Tc(NO)(py)4F](+), [Tc(NO)(NH3)4F](+), and [Tc(NO)(NH3)4F](2+).

Adsorption of technetium-99m tetrofosmin and technetium-99m furifosmin on plastic syringes

International Nuclear Information System (INIS)

Bartosch, R.; Granegger, S.; Sinzinger, H.

1998-01-01

Some groups have reported that adsorption of radiopharmaceuticals on disposable plastic syringes can reach levels of almost 50%. This high loss of radioactivity stimulated us to carry out similar studies. Our measurements were done in combination with patient studies. Therefore, we used 2-ml syringes, all of the same brand. The radioactivity in the syringe was measured immediately before and after injection. a total of 500-600 MBq technetium-99m labelled tetrofosmin or technetium-99m furifosmin was administered to 48 patients using four different injection techniques (n = 6 for each technique with each tracer): with needles, 1 min blood incubation at 22 C, 10 or 30 min after preparation of the tracer; with butterflies, 1 min blood incubation at 22 C, 10 or 30 min after preparation of the tracer. Neither in syringes nor in needles or butterflies did more than 7% of the initial radioactivity remain. The entire residual activity in syringe plus needle or syringe plus butterfly together never exceeded the 9% limit. Furthermore, in a pilot study we measured the remaining radioactivity in the vial; here, too, we found no more than 14% of total radioactivity. These findings indicate that total retention of radioactivity during elution and application of 99m Tc-tetrofosmin and 99m Tc-furifosmin with material used in our setting does not approach relevant amounts. (orig.)

Adsorption of methyl iodide on charcoal

International Nuclear Information System (INIS)

Hidajat, K.; Aracil, J.; Kenney, C.N.

1990-01-01

The adsorption of non-radioactive methyl iodide has been measured experimentally over a range of conditions of concentration, and temperature on an activated charcoal. This is of interest since methyl iodide is formed from iodine fission products in gas cooled nuclear reactors. A mathematical model has also been developed which describes the rate of adsorption, under isothermal and linear adsorption isotherm conditions in a recycle adsorber. This model takes into account the resistance to adsorption caused by the surface adsorption, as well as the external and internal mass transfer resistances. The solution to the model for the recycle adsorber was obtained using a semidiscretisation method to reduce the partial differential equations to a system of stiff ordinary differential equations, and the resulting differential equations solved by a standard numerical technique. (author)

FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

International Nuclear Information System (INIS)

Soelberg, Nicholas Ray; Watson, Tony Leroy

2015-01-01

Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO 3 and increased NO 2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO 2 , very low H 2 O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I 2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

Energy Technology Data Exchange (ETDEWEB)

Adamic, M.L., E-mail: Mary.Adamic@inl.gov [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Vockenhuber, C. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Watrous, M.G. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States)

2015-10-15

This paper presents an evaluation of an alternate method for preparing environmental samples for {sup 129}I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

International Nuclear Information System (INIS)

Adamic, M.L.; Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E.; Vockenhuber, C.; Watrous, M.G.

2015-01-01

This paper presents an evaluation of an alternate method for preparing environmental samples for "1"2"9I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

Comparison between hemosiderin and Technetium-99 in sentinel lymph node biopsy in human breast cancer

International Nuclear Information System (INIS)

Vasques, Paulo Henrique Diogenes; Aquino, Ranniere Gurgel Furtado de; Pinheiro, Luiz Gonzaga Porto; Torres, Roberto Vitor Almeida; Bezerra, Jose Lucas Martins; Brasileiro, Luis Porto

2015-01-01

Purpose: To assess the safety and potential equivalence of the use of hemosiderin compared to the Technetium-99 in sentinel lymph node biopsy in human breast cancer. Methods: Non-random sample of 14 volunteer women diagnosed with breast cancer with primary tumors (T1/T2) and clinically tumor-free axilla were submitted to the identification of sentinel lymph node using hemosiderin obtained from autologous blood injected in the periareolar region 24h before surgery on an outpatient basis. Patients received preoperative subareolar intradermal injection of Technetium-99 in the immediate preoperative period. Patients were submitted to sentinel lymph node biopsy, with incision in the axillary fold guided by Gamma-Probe, dissection by planes until the identification of the point of maximum uptake of Technetium-99, identifying the marked nodes and their colors. All surgical specimens were sent for pathological and immunohistochemical study. Results: The results showed no evidence of side effects and/or allergic and non-allergic reactions in patients submitted to SLNB with hemosiderin. The SLN identification rate per patient was 100%. SLNB identification rate per patient with hemosiderin was the same as that of Technetium, with a concordance rate of 100% between the methods. Conclusion: Hemosiderin is a safe dye that is equivalent to Technetium in breast sentinel lymph node biopsy. (author)

Comparison between hemosiderin and Technetium-99 in sentinel lymph node biopsy in human breast cancer

Energy Technology Data Exchange (ETDEWEB)

Vasques, Paulo Henrique Diogenes; Aquino, Ranniere Gurgel Furtado de; Pinheiro, Luiz Gonzaga Porto, E-mail: luizgporto@uol.com.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Departamento de Cirurgia; Alves, Mayara Maia [Rede Nordeste de Biotecnologia (RENORBIO/UFC), Fortaleza, CE (Brazil); Torres, Roberto Vitor Almeida; Bezerra, Jose Lucas Martins [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Faculdade de Medicina; Brasileiro, Luis Porto [Faculdades INTA, Sobral, CE (Brazil). Faculdade de Medicina

2015-11-15

Purpose: To assess the safety and potential equivalence of the use of hemosiderin compared to the Technetium-99 in sentinel lymph node biopsy in human breast cancer. Methods: Non-random sample of 14 volunteer women diagnosed with breast cancer with primary tumors (T1/T2) and clinically tumor-free axilla were submitted to the identification of sentinel lymph node using hemosiderin obtained from autologous blood injected in the periareolar region 24h before surgery on an outpatient basis. Patients received preoperative subareolar intradermal injection of Technetium-99 in the immediate preoperative period. Patients were submitted to sentinel lymph node biopsy, with incision in the axillary fold guided by Gamma-Probe, dissection by planes until the identification of the point of maximum uptake of Technetium-99, identifying the marked nodes and their colors. All surgical specimens were sent for pathological and immunohistochemical study. Results: The results showed no evidence of side effects and/or allergic and non-allergic reactions in patients submitted to SLNB with hemosiderin. The SLN identification rate per patient was 100%. SLNB identification rate per patient with hemosiderin was the same as that of Technetium, with a concordance rate of 100% between the methods. Conclusion: Hemosiderin is a safe dye that is equivalent to Technetium in breast sentinel lymph node biopsy. (author)

Non-pertechnetate Technetium Sensor Research and Development

Energy Technology Data Exchange (ETDEWEB)

Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rapko, Brian M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Branch, Shirmir D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Univ. of Cincinnati, OH (United States); Lines, Amanda M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heineman, William R. [Univ. of Cincinnati, OH (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-03-24

Several significant uncertainties remain regarding the understanding and modeling of the fate and speciation of technicium-99 (⁹⁹Tc) in Hanford waste tanks, glass, and low-temperature waste forms. A significant (2% to 25%) fraction of the 99Tc in the water-soluble portion of the tank waste may be present as one or more non pertechnetate species that have not been identified and to date, cannot be effectively separated from the wastes. This task will provide a sensor specifically tuned to detect the Tc(I)-carbonyl species believed to constitute the main fraction of the non-pertechnetate form of technetium. By direct measurement of the non-pertechnetate species, such a sensor will help reduce the uncertainties in the modeling of the fate and speciation of ⁹⁹Tc in Hanford tanks and waste forms. This report summarizes work performed in FY2016 that was sponsored by the Department of Energy’s Office of Environmental Management and demonstrates the protocol for using fluorescent Tc(I)-tricarbonyl complex as a means to detect the non-pertechnetate species within tank waste solutions. The protocol was optimized with respect to ligand concentration, solvent choice, reaction temperature and time. This work culminated in the quantitation of Tc(I)-tricarbonyl within a waste simulant, using a standard addition method for measurement. This report also summarizes the synthesis and high-yield preparation of the low-valence technetium species, [Tc(CO)₃(H₂O)₃]⁺, which will be used as the technetium standard material for the demonstration of the non-pertechnetate species in actual wastes.

Method for radiolabeling proteins with technetium-99m

International Nuclear Information System (INIS)

Crockford, D.R.; Rhodes, B.A.

1984-01-01

In accordance with this invention, a substrate to be radiolabeled with technetium-99m is admixed with a buffered stannous chloride composition having a pH between about 4.5 and about 8.5 wherein the stannous chloride is produced from a non-oxidized tin source, the buffered stannous chloride is purged of oxygen and the buffer comprises a mixture of alkali metal biphthalate and an alkali metal tartrate. Alternatively, the buffer may include alkali metal borate or gentisate. The stannous chloride solution is admixed with the buffer and the resultant mixture is neutralized with sodium hydroxide. The neutralized solution then is admixed with the substrate eventually to be radiolabeled with technetium-99m. This solution is allowed to incubate for several hours (usually over 15 hours) in the absence of oxygen and at room temperature

Physics of the missing atoms: technetium and promethium

International Nuclear Information System (INIS)

Aspden, H.

1987-01-01

Technetium (Z = 43) and promethium (Z = 61) are by far the least abundant of all atoms below the radioactive elements (Z = 84 onwards). Their scarcity confirms theoretical predictions emerging from a theory of the photon derived from synchronous lattice electrodynamics. This theory has given precise theoretical values for the fine-structure constant and the constant of gravitation G and is now shown in this paper to indicate resonant interactions between the vacuum lattice oscillations and technetium and promethium. In the case of promethium there is strong reason for believing that this atom can assume supergravitational or antigravitational properties, accounting for its scarcity. This paper not only adds support to the earlier theoretical work on the photon and gravitation, but suggests a research route that might lead to new technology based on controlled interactions with gravity fields

Autoradiolytic decomposition and reductant-free sodium sup 124 I- and sup 123 I-iodide

Energy Technology Data Exchange (ETDEWEB)

Sajjad, M.; Lambrecht, R.M.; Bakr, S.A. (King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Radionuclide and Cyclotron Operations)

1990-01-01

The presence of salts and metal cations in {sup 124}I- and {sup 123}I-sodium iodide solutions separated from {sup 124}Te targets promots autoradiolytic decomposition of iodide to several different iodine species dependent upon the chemical environment. The stabilization of the radioiodine as iodide by removal of trace salts and trace metal cations and in the absence of reducing agents is described. The high specific activity {sup 123}I- and {sup 124}I-iodide is suitable for labeling antibodies, proteins and radiopharmaceuticals. (orig.).

An investigation of sodium iodide solubility in sodium-stainless steel systems

International Nuclear Information System (INIS)

Sagawa, Norihiko; Tashiro, Suguru

1996-01-01

Sodium iodide and major constituents of stainless steel in sodium are determined by using the steel capsules to obtain a better understanding on contribution of the constituents to the apparent iodide solubility in sodium. The capsule loaded with 20 g sodium and 0.1 - 0.3 g powder of sodium iodide is heated at its upper part in a furnace and cooled at its bottom on brass plates to establish a large temperature gradient along the capsule tube. After a given period of equilibration, the iodide and constituents are fixed in solidified sodium by quick quenching of the capsules. Sodium samples are taken from the sectioned capsule tube and submitted to sodium dissolution by vaporized water for determination of the iodine and to vacuum distillation for determination of the metal elements. Iron and nickel concentrations are observed to be lower in the samples at higher iodine concentrations. Chromium and manganese concentrations are seen to be insensitive to the iodine concentrations. The observations can be interpreted by a model that sodium oxide combines with metal iodide in sodium to form a complex compound and with consideration that the compound will fall and deposit onto the bottom of the capsule by thermal diffusion. (author)

Preparation and quality control of technetium-99m radiopharmaceuticals

International Nuclear Information System (INIS)

Samuels, D.L.

1978-11-01

Appropriate procedures for the production and quality control of technetium-99m based radiopharmaceuticals in hospital radiopharmacy consistent with the recently published Australian Code of Good Manufacturing Practice are discussed

Evaluation of quaternary ammonium halides for removal of methyl iodide from flowing air streams

International Nuclear Information System (INIS)

Freeman, W.P.; Mohacsi, T.G.; Kovach, J.L.

1985-01-01

The quaternary ammonium halides of several tertiary amines were used as impregnants on activated carbon and were tested for methyl iodide penetration in accordance with test Method A, ASTM D3803, 1979, ''Standard Test Methods for Radio-iodine Testing of Nuclear Grade Gas Phase Adsorbents''. The results suggest that the primary removal mechanism for methyl iodide-131 is isotopic exchange with the quaternary ammonium halide. For example, a 5 wt% impregnation of each of the tetramethyl, tetraethyl, tetrapropyl and tetrabutyl ammonium iodides on activated carbon yielded percent penetrations of 0.47, 0.53, 0.78, and 0.08 respectively when tested according to Method A of ASTM D3803. A sample impregnated with 5% tetramethyl ammonium hydroxide gave a methyl iodide penetration of 64.87%, thus supporting the isotopic exchange mechanism for removal. It has been a generally held belief that the success of tertiary amines as impregnants for radioiodine removal is a result of their ability to complex with the methyl iodide. The results of the work indicates that the superiority of the tertiary amines similar to triethylene diamine and quinuclidine, when compared to their straight chain analogs, is a result of their ease in reacting with methyl iodide-127 to form the quaternary ammonium iodide followed by isotopic exchange

LABORATORY REPORT ON THE REDUCTION AND STABILIZATION (IMMOBILIZATION) OF PERTECHNETATE TO TECHNETIUM DIOXIDE USING TIN(II)APATITE

Energy Technology Data Exchange (ETDEWEB)

DUNCAN JB; HAGERTY K; MOORE WP; RHODES RN; JOHNSON JM; MOORE RC

2012-06-01

This effort is part of the technetium management initiative and provides data for the handling and disposition of technetium. To that end, the objective of this effort was to challenge tin(II)apatite (Sn(II)apatite) against double-shell tank 241-AN-105 simulant spiked with pertechnetate (TcO{sub 4}{sup -}). The Sn(II)apatite used in this effort was synthesized on site using a recipe developed at and provided by Sandia National Laboratories; the synthesis provides a high quality product while requiring minimal laboratory effort. The Sn(II)apatite reduces pertechnetate from the mobile +7 oxidation state to the non-mobile +4 oxidation state. It also sequesters the technetium and does not allow for re-oxidization to the mo bile +7 state under acidic or oxygenated conditions within the tested period oftime (6 weeks). Previous work (RPP-RPT-39195, Assessment of Technetium Leachability in Cement-Stabilized Basin 43 Groundwater Brine) indicated that the Sn(II)apatite can achieve an ANSI leachability index in Cast Stone of 12.8. The technetium distribution coefficient for Sn(II)apatite exhibits a direct correlation with the pH of the contaminated media. Table A shows Sn(II)apatite distribution coefficients as a function of pH. The asterisked numbers indicate that the lower detection limit of the analytical instrument was used to calculate the distribution coefficient as the concentration of technetium left in solution was less than the detection limit. The loaded sample (200 mg of Sn(II)apatite loaded with O.311 mg of Tc-99) was subjected to different molarities of nitric acid to determine if the Sn(II)apatite would release the sequestered technetium. The acid was allowed to contact for 1 minute with gentle shaking ('1st wash'); the aqueous solution was then filtered, and the filtrate was analyzed for Tc-99. Table B shows the results ofthe nitric acid exposure. Another portion of acid was added, shaken for a minute, and filtered ('2nd wash'). The

FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

Energy Technology Data Exchange (ETDEWEB)

Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-30

Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO₃ and increased NO₂ concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO₂, very low H₂O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I₂ using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Discovery of aryl-tri-fluoroborates as potent sodium/iodide sym-porter (NIS) inhibitors

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Ambroise, Y.

2008-01-01

The structure-based design of sodium/iodide sym-porter (NIS) inhibitors identified new active compounds. The organo-tri-fluoroborate shown was found to inhibit iodide uptake with an IC50 value of 0.4 μM on rat-derived thyroid cells. The biological activity is rationalized by the presence of the BF3 - ion as a minimal binding motif for substrate recognition at the iodide binding site. (authors)

Discovery of aryl-tri-fluoroborates as potent sodium/iodide sym-porter (NIS) inhibitors

Energy Technology Data Exchange (ETDEWEB)

Lecat-Guillet, N.; Ambroise, Y. [CEA, DSV, Dept Bioorgan Chem and Isotop Labelling, Inst Biol and Technol, iBiTecS, F-91191 Gif Sur Yvette (France)

2008-07-01

The structure-based design of sodium/iodide sym-porter (NIS) inhibitors identified new active compounds. The organo-tri-fluoroborate shown was found to inhibit iodide uptake with an IC50 value of 0.4 {mu}M on rat-derived thyroid cells. The biological activity is rationalized by the presence of the BF3{sup -} ion as a minimal binding motif for substrate recognition at the iodide binding site. (authors)

Early effects of external gamma irradiation on iodide metabolism in rat thyroid

International Nuclear Information System (INIS)

Niatsetskaya, Z.; Nadolnik, L.

2006-01-01

Full text of publication follows: The exposure of the thyroid gland to therapeutic doses of external gamma irradiation is frequently associated with thyroid dysfunction. Although late irradiation effects are well documented, little is still known about the early functional alterations in the thyroid subjected to radiation therapy. The aim of this study was to examine the early effect of single external gamma irradiation on iodide metabolism in the thyroid. The Wistar female rats were irradiated using a 60 Co installation with a constant capacity of 0.64 Gy/min. The doses used were 0.25, 0.5, 1, 2, 5 Gy. The animals were sacrificed after 24 hours following the irradiation. T he thyroid organ culture was cultivated during 24 h and than was irradiated with a single dose of 5 Gy. The thyroid tissue was assayed for thyro-peroxidase activity and concentrations of total, free and protein -binding iodide. It was shown that the 0.25 Gy irradiation depressed thyroid iodide uptake, which was manifested in decreasing total iodide by 25%. The same tendency was observed after the 0.5 Gy irradiation. In the 1, 2, 5 Gy groups, the concentrations of total and free iodide increased by 26 -34% and 50-68%, accordingly. The level of protein-binding iodide in these groups was within the control values. However, protein-binding/total iodide and protein binding/ free iodide ratios decreased by 17 -41%, suggesting inhibition of thyroglobulin iodination. Thyro-peroxidase (T.P.O.) plays a key role in thyroid hormone synthesis by catalyzing both the iodination of thyroglobulin and the coupling some of the iodo-tyrosyl residues. After 24 hours on irradiation, a 31.5-54% dose-dependent inhibition of T.P.O. activity was shown in the 1, 2 and 5 Gy groups. The irradiation of the rat thyroid organ culture with a single dose of 5 Gy also led to significant inhibition of T.P.O. by 56.91% after 2 hours. We compared the enzyme kinetics of thyro-peroxidase from thyroid microsomal fraction control and

Quantitative radiocardiography by single-probe counting using sup(99m)technetium albumin

International Nuclear Information System (INIS)

Man in 't Veld, A.J.; Wenting, G.J.; Verhoeven, R.P.; Schalekamp, M.A.D.H.

1978-01-01

Quantitative radiocardiography with sup(99m)Technetium albumin, using a single probe for percordial counting of radioactivity is a non-invasive technique to measure cardiac output. sup(99m)Technetium pertechnetate is bound to albumin by electrolytic complexation. Preparations of sup(99m)Technetium albumin showed small percentages of free radioactivity. In-vivo stability of the complex was confirmed by comparison with distribution volumes of 131 Iodine albumin and sup(113m)Indium transferrin. The isotope dilution cardiac output technique was validated by comparison with a classical indocyanine green dilution method. Results obtained by peripheral intravenous injection of the isotope were not different from those after intracardiac injection. Exact localization of the collimator over the heart was not critical. Duplicate measurements showed good reproducibility. Examples of serial measurements in patients with hyperthyroidism, primary aldosteronism and essential hypertinsion are given. The method is reliable, accurate and safe and causes no discomfort to the patient. (C.F.)

Linearity and Reversibility of Iodide Adsorption on Sediments from Hanford, Washington Under Water Saturated Conditions

International Nuclear Information System (INIS)

Um, Wooyong; Serne, R. Jeffrey; Krupka, Kenneth M.

2004-01-01

A series of adsorption and desorption experiments were completed to determine the linearity of iodide adsorption, as a function of concentration, and its reversibility onto sediment for geochemical conditions germane to the proposed disposal of low-level radioactive waste by the U.S. Department of Energy's Immobilized Low Activity Waste (ILAW) program at the Hanford Site in southeastern Washington. Iodine-129 is predicted to be one of the top three long-term risk drivers based on past performance assessment conducted for the eventual disposal of the low-level portion of radioactive wastes currently stored in underground storage tanks at Hanford, because iodide exhibits little adsorption affinity to mineral surfaces resulting in high mobility in the subsurface environment. Adsorption experiments, conducted with Hanford formation sediments and groundwater spiked with dissolved 125I (as an analog tracer for 129I), indicated that iodide adsorption was very low at pH 7.5 and could be represented by a linear isotherm up to a total concentration of 100 mg/L dissolved iodide. The linearity of iodide adsorption up to concentrations of 100 mg/L validates the use of the linear Kd construct in transport models to predict the fate and transport of 129I in subsurface systems at Hanford. The results of desorption experiments indicated that up to 60% of adsorbed iodide was readily desorbed after 14 days by the same groundwater solution. Iodide adsorption was considered to be partially reversible or weakly binding on the sediments. Even though small amount of initial iodide is retarded by adsorption reactions at mineral-water interfaces, the weak adsorption affinity results in release of iodide when iodide free pore waters and ground waters contact the contaminated sediments in the vadose zone and aquifer systems

Sodium iodide symporter: Its role in nuclear oncology

International Nuclear Information System (INIS)

Chung, June-Key

2004-01-01

Full text: Thyroid iodide uptake is basic to the clinical applications of radioiodine in diagnosis and therapy. Iodide uptake occurs across the membrane of thyroid follicular cells via an active transporter process mediated by the sodium/iodide symporter (NIS). The recent cloning of the gene encoding NIS enabled better characterization of the molecular mechanisms underlying the iodide transport, thus opening the way to clarify and expand its role in medicine. NIS contains 13 transmembrane segments, and its gene encodes a glycoprotein of 643 amino acids. Decreased NIS expression levels account for the reduced iodide uptake in thyroid carcinomas. We found that thyroid cancer patients with positive immunostaining for NIS responded to I-131 therapy better than did the patients with negative immunostaining. Thus, NIS gene can be used for radionuclide gene therapy. Targeted expression of functional NIS in cancer cells would enable these cells to concentrate iodide from plasma and would, therefore, offer the possibility of radioiodine therapy. We and others have shown that gene transfer of NIS into a variety of cell types confers increased radioiodine uptake up to several hundred-fold that of controls. There is great interest in exploring the possibility of NIS gene transfer to facilitate radioiodine therapy for non-thyroidal human cancers including hepatoma, prostate, breast, colon cancers as well as thyroid cancer. Recently, several approaches such as, targeted gene transfer, thyroid peroxidase gene co-transfection, retinoic acid treatment and Re-188 therapy instead of I-131, have been tried to improve this novel gene therapy. Imaging reporter gene is useful in non-invasively determining the location, duration and magnitude of transgene expression in living animal. Conventionally, HSV-tk and dopaminergic receptor (D2R) genes have been presented as possible imaging reporter genes. We proved that NIS could serve as an alternative imaging reporter gene. NIS has many

ASSESSMENT OF TECHNETIUM LEACHABILITY IN CEMENT STABILIZED BASIN 43 GROUNDWATER BRINE

International Nuclear Information System (INIS)

COOKE GA; DUNCAN JB; LOCKREM LL

2008-01-01

This report is an initial report on the laboratory effort executed under RPP-PLAN-33338, Test Plan for the Assessment of Technetium Leachability in Cement-Stabilized Basin 43 Groundwater Brine. This report delineates preliminary data obtained under subcontract 21065, release 30, from the RJ Lee Group, Inc., Center for Laboratory Sciences. The report is predicated on CLS RPT-816, Draft Report: Assessment of Technetium Leachability in Cement Stabilized Basin 43 Groundwater Brine. This document will be revised on receipt of the final RJ Lee Group, Inc., Center for Laboratory Sciences report, which will contain data subjected to quality control and quality assurance criteria

Iodine K-edge EXAFS analysis of iodide ion-cyclodextrin inclusion complexes in aqueous solution

International Nuclear Information System (INIS)

Kaneko, T; Ueda, M; Nagamatsu, S; Konishi, T; Fujikawa, T; Mizumaki, M

2009-01-01

We study the structure of inclusion complexes of α-, β-, γ-cyclodextrin with mono-iodide ion in aqueous solution by means of iodine K-edge EXAFS spectroscopy. The analysis is based on the assumption that two kinds of iodide ions exist in KI-cyclodextrin aqueous solution i.e. hydrated mono-iodide ions and one-one mono-iodide-cyclodextrin inclusion complexes. In KI-α-cyclodextrin system, iodine K-edge EXAFS analyse show that the average coordination number of the oxygen atoms in water molecules in the first hydration shell decreases as the fraction of included ions increases. This result suggests that dehydration process accompanies the formation of the inclusion complex. This is not found in the case of β-cyclodextrin, indicating that in this case the iodide ions are included together with the whole first hydration shell.

Chemistry of rhenium and technetium. II. Schiff base complexes with polyfunctional amino acids

International Nuclear Information System (INIS)

Du Preez, J.G.H.; Gerber, T.I.A.; Fourie, P.J.; Van Wyk, A.J.

1984-01-01

Amino acid Schiff base technetium(V) complexes of salicylaldehyde with l-cysteine, l-serine, l-histodine, l-threonine, l-glutamic acid and l-tryptophan have been preapred by direct reaction and by constituent combination. The amino acid part of the ligands coordinates to the technetium through the carboxylate group, while the other available functional group of the amino acids plays a more minor role as blocking group or in intramolecular bonding. 3 tables

Adsorption of technetium-99m tetrofosmin and technetium-99m furifosmin on plastic syringes

Energy Technology Data Exchange (ETDEWEB)

Bartosch, R.; Granegger, S.; Sinzinger, H. [Department of Nuclear Medicine, University of Vienna (Austria)

1998-09-01

Some groups have reported that adsorption of radiopharmaceuticals on disposable plastic syringes can reach levels of almost 50%. This high loss of radioactivity stimulated us to carry out similar studies. Our measurements were done in combination with patient studies. Therefore, we used 2-ml syringes, all of the same brand. The radioactivity in the syringe was measured immediately before and after injection. a total of 500-600 MBq technetium-99m labelled tetrofosmin or technetium-99m furifosmin was administered to 48 patients using four different injection techniques (n = 6 for each technique with each tracer): with needles, 1 min blood incubation at 22 C, 10 or 30 min after preparation of the tracer; with butterflies, 1 min blood incubation at 22 C, 10 or 30 min after preparation of the tracer. Neither in syringes nor in needles or butterflies did more than 7% of the initial radioactivity remain. The entire residual activity in syringe plus needle or syringe plus butterfly together never exceeded the 9% limit. Furthermore, in a pilot study we measured the remaining radioactivity in the vial; here, too, we found no more than 14% of total radioactivity. These findings indicate that total retention of radioactivity during elution and application of {sup 99m}Tc-tetrofosmin and {sup 99m}Tc-furifosmin with material used in our setting does not approach relevant amounts. (orig.) With 4 figs., 1 tab., 7 refs.

Contributions to the coordination chemistry of technetium

International Nuclear Information System (INIS)

Lorenz, B.

1989-08-01

New types of technetium complexes were synthesized and analyzed by IR-, 1 H- and 99 Tc nmr as well as EPR spectra. They were tested for their potential catalytic activity in special organic reactions and their relevance to catalytic reactions, for example as intermediate compounds, is discussed in depth. 317 refs., 20 figs. (BBR) [de

Nature`s uncommon elements: Plutonium and technetium

Energy Technology Data Exchange (ETDEWEB)

Curtis, D.; Fabryka-Martin, J.; Dixon, P. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.; Cramer, J. [Atomic Energy of Canada Ltd., Pinawa, Manitoba (Canada). Whiteshell Lab.

1998-01-06

The authors have taken advantage of the extremely sensitive method of thermal ionization mass spectrometry to measure technetium and plutonium concentrations in sample masses that are smaller by as much as three orders of magnitude than those used in the early research efforts. The work reported in this paper extends the understanding of the geochemistry of plutonium and technetium by developing detailed descriptions of their associations in well characterized geologic samples, and by using modern neutron-transport modeling tools to better interpret the meaning of the results. Analyses were conducted on samples from three uranium ore deposits selected for their contrasting geochemical environments. The Cigar Lake deposit is an unweathered, unaltered primary ore in a reducing environment which is expected to closely approximate a system that is closed with respect to uranium and its products. The Koongarra deposit is a shallow system, both altered and weathered, subject to active ground water flow. Finally, a sample from the Beaverlodge deposit is included because it is a commercially-available uranium ore standard that allows demonstration of the precision of the analytical results.

Fundamental chemistry, characterization, and separation of technetium complexes in Hanford waste. 1998 annual progress report

International Nuclear Information System (INIS)

Ashley, K.R.; Blanchard, D.L. Jr.; Schroeder, N.C.

1998-01-01

'The ultimate goal of this proposal is to separate technetium from Hanford tank waste. The recent work has shown that a large portion of the technetium is not pertechnetate (TcO 4 - ) and is not easily oxidized. This has serious repercussions for technetium partitioning schemes because they are designed to separate this chemical form. Rational attempts to oxidize these species to TcO 4 - for processing or to separate the non-pertechnetate species themselves would be facilitated by knowing the identity of these complexes and understanding their fundamental chemistry. Tank characterization work has not yet identified any of the non-pertechnetate species. However, based on the types of ligands available and the redox conditions in the tank, a reasonable speculation can be made about the types of species that may be present. Thus, this proposal will synthesize and characterize the relevant model complexes of Tc(III), Tc(IV), and Tc(V) that may have formed under tank waste conditions. Once synthesized, these complexes will be used as standards for developing and characterizing the non-pertechnetate species in actual waste using instrumental techniques such as capillary electrophoresis electrospray mass spectrometry (CE-MS), x-ray absorbance spectroscopy (EXAFS and XANES), and multi-nuclear NMR (including 99 Tc NMR). The authors study the redox chemistry of the technetium complexes so that more efficient and selective oxidative methods can be used to bring these species to TcO 4 - for processing purposes. They will also study their ligand substitution chemistry which could be used to develop separation methods for non-pertechnetate species. Understanding the fundamental chemistry of these technetium complexes will enable technetium to be efficiently removed from the Hanford tank waste and help DOE to fulfill its remediation mission. This report summarizes the first 8 months of a 3-year project.'

Technical problems associated with the production of technetium Tc 99m tin(II) pyrophosphate kits

International Nuclear Information System (INIS)

Kowalsky, R.J.; Dalton, D.R.

1981-01-01

The amount of tin(II) required for adequate reduction, complexation, and stability of technetium Tc 99m pertechnetate in radiopharmaceutical kits, and methods of preventing the loss of tin(II) during formulation of these lyophilized kits are investigated. Tin(II) loss from stannous chloride solutions was studied under several conditions, including room air versus nitrogen atmospheres, during vial filling in a laminar-flow hood with samples frozen on dry ice versus samples at room temperature, during lyophilization, and during storage under refrigerated, ambient, and elevated temperatures. Various amounts of stannous chloride, ranging from 5 to 1000 microgram/ml, were used in formulating sodium pertechnetate Tc 99m kits containing 100 mCi technetium Tc 99m and 0.4 microgram total technetium. Samples were removed at various times; hydrolyzed technetium, pertechnetate, and technetium Tc 99m pyrophosphate were isolated on instant thin-layer chromatography-silica gel and quantified with a scintillation counter. The time necessary to deoxygenate distilled water by nitrogen purging was measured. Several sources of stannous chloride were assayed for tin(II) content. Tin(II) loss occurs rapidly in solution (15% in one hour) unless continuously protected with nitrogen, and during vial filling in a laminar-flow hood unless frozen with dry ice. No substantial loss of tin(II) was detected during lyophilization or during storage of lyophilized product at any of the three temperatures. A minimum of 400 microgram tin(II) was required to provide 90% technetium Tc 99m pyrophosphate at six hours after preparation. Adequate deoxygenation of small quantities (450 ml) of water was accomplished in less than one hour. Some stannous chloride salts were highly oxidized in the dry state, and only high-purity elemental tin wire gave acceptable yields of tin

Clinical value of sodium iodide symporter

International Nuclear Information System (INIS)

Li Qian

2003-01-01

The sodium iodide symptorter (NIS) is a membrane glycoprotein that mediates iodide uptake in the thyroid gland and several extrathyroidal tissues. In addition to thyroid tissues, the expression of NIS is found in stomach, prostate, placenta and so on. Radioiodine-concentrating activity in thyroid tissues has allowed the use of radioiodine as a diagnostic and therapeutic agent for patients with thyroid disorders. However, some extrathyroid tissues also take up radioiodine, contributing to unwanted side effects of radioiodine therapy. Now that the molecule of NIS has been cloned and characterized, it may be possible to develop novel strategies to differentially modulate NIS expression and activity, enhancing it in target tissues and impeding it in others. It is also important to explore the use of NIS as an imaging reporter gene to monitor the expression profile of the transgene in transgenic mouse animal models and in patients undergoing gene therapy clinical trials

Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma

Energy Technology Data Exchange (ETDEWEB)

Yoshinari, M.; Tokuyama, T.; Okamura, K.; Sato, K.; Kusuda, K.; Fujishima, M.

1988-04-15

An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate /sup 131/I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of /sup 131/I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved.

Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma

International Nuclear Information System (INIS)

Yoshinari, M.; Tokuyama, T.; Okamura, K.; Sato, K.; Kusuda, K.; Fujishima, M.

1988-01-01

An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate 131 I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of 131 I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved

The origins of Technetium in the environment

International Nuclear Information System (INIS)

Scoppa, P.

1986-01-01

The origins of Technetium in the environment are briefly illustrated, taking into account its main sources represented by same plants of nuclear fuel cycle and by fallout fallowing nuclear explosion in atmosphere. An evaluation is also made of the TC-99 quantitees deriving from the production of nuclear power present in radioactive wastes before their final disposal

The value of iodide as a parameter in the chemical characterisation of groundwaters

Science.gov (United States)

Lloyd, J. W.; Howard, K. W. F.; Pacey, N. R.; Tellam, J. H.

1982-06-01

Brackish and saline groundwaters can severely constrain the use of fresh groundwaters. Their chemical characterisation is important in understanding the hydraulic conditions controlling their presence in an aquifer. Major ions are frequently of limited value but minor ions can be used. Iodide in groundwater is particularly significant in many environments due to the presence of soluble iodine in aquifer matrix materials. Iodide is found in groundwaters in parts of the English Chalk aquifer in concentrations higher than are present in modern seawater. Its presence is considered as a indication of groundwater residence and is of use in the characterisation of fresh as well as saline waters. Under certain circumstances modern seawater intrusion into aquifers along English estuaries produces groundwaters which are easily identified due to iodide enrichment from estuarine muds. In other environments iodide concentrations are of value in distinguishing between groundwaters in limestones and shaly gypsiferous rocks as shown by a study in Qatar, while in an alluvial aquifer study in Peru iodide has been used to identify groundwaters entering the aquifer from adjacent granodiorites.

Physical chemical quality control of the molybdenum technetium generator

International Nuclear Information System (INIS)

Olive, E.; Cruz, J.; Isaac, M.; Gamboa, R.; D'Alessandro, K.; Desdin, L.F.

1995-01-01

Comparative operational procedure imported molybdenum technetium generators have been made. Procedures for determination of chemical, radiochemical and radionuclidic purities that may be applied in Hospital's laboratories and in the quality control of generators production are developed

Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation

International Nuclear Information System (INIS)

Hermon, H.; James, R.B.; Lund, J.

1998-01-01

In this study the authors report on the results of the investigation of lead iodide material properties. The effectiveness of a zone refining purification method on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. They show that this zone refining method is very efficient in removing impurities from lead iodide, and they also determine the segregation coefficient for some of these impurities. Triple axis X-ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was much improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier-phonon scattering. The results for the electrical properties were in good agreement with the experimental data

Structural templating in a nonplanar phthalocyanine using single crystal copper iodide

OpenAIRE

Rochford, L. A. (Luke A.); Ramadan, Alexandra J.; Keeble, Dean S.; Ryan, Mary P.; Heutz, Sandrine; Jones, T. S. (Tim S.)

2015-01-01

Solution-grown copper iodide crystals are used as substrates for the templated growth of the nonplanar vanadyl phthalocyanine using organic molecular beam deposition. Structural characterization reveals a single molecular orientation produced by the (111) Miller plane of the copper iodide crystals. These fundamental measurements show the importance of morphology and structure in templating interactions for organic electronics applications.

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

Energy Technology Data Exchange (ETDEWEB)

Holm, J.; Ekberg, C. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT, Espoo (Finland)); Glaenneskog, H. (Vattenfall Power Consultant, Goeteborg (Sweden))

2011-05-15

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment, was started. During year 2008 (NROI-1) the radiolytic oxidation of elemental iodine was investigated and during 2009 (NROI-2), the radiolytic oxidation of organic iodine was studied. This project (NROI-3) is a continuation of the investigation of the oxidation of organic iodine. The project has been divided into two parts. 1. The aims of the first part were to investigate the effect of ozone and UV-radiation, in dry and humid conditions, on methyl iodide. 2. The second project was about gamma radiation (approx20 kGy/h) and methyl iodide in dry and humid conditions. 1. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UV-radiation intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. The particle formation was instant and extensive when methyl iodide was exposed to ozone and/or radiation at all temperatures. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-200 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine oxides (I{sub xO{sub y}). However, the correct speciation of the formed particles was difficult to obtain because the particles melted and fused together under the electron beam. 2. The results from this sub-project are more inconsistent and hard to interpret. The particle formation was significant lesser than corresponding experiments when ozone/UV-radiation was used instead of gamma radiation. The transport of gaseous methyl iodide through the facility was

Gravimetric determination of cadmium with o-phenanthroline and iodide

International Nuclear Information System (INIS)

Yoshida, Hitoshi; Mizuno, Kazunori; Taga, Mitsuhiko; Hikime, Seiichiro

1976-01-01

Cadmium forms insoluble mixed ligand complex with o-phenanthroline and iodide ions. By using the complex a new gravimetric method for the determination of cadmium was investigated. The recommended analytical procedure is as follows: Adjust pH value of a solution containing 5 to 45 mg cadmium to 4 with 3 M acetic acid-sodium acetate buffer solution. Add over threefold moles of potassium iodide to the solution and heat to just before boiling. To the solution add 0.1% ascorbic acid solution and then 0.1 M o-phenanthroline solution drop by drop in excess with stirring, and cool the mixture to room temperature. Filter the precipitates and wash first with 0.01% potassium iodide solution and then with water. Dry the precipitates at 110 0 C for two hours and weigh as Cd(o-phen) 2 I 2 (I). The gravimetric factor of the complex for cadmium is 0.1547. Chemical composition of the precipitate is variable when o-phenanthroline is added less than twofold moles to cadmium. Adding the o-phenanthroline solution 2.4-fold moles against cadmium, the ternary complex (I) precipitates quantitatively. Though a large excess of iodide ion in the solution contaminated the precipitate, the contamination was avoided when precipitation was carryed out at high temperature and in the presence of ascorbic acid. By the presented procedure 5 to 45 mg of cadmium are determined with a standard deviation of 0 C. (JPN)

Trapping radiodine, in the form of methyl iodide, on nuclear carbon

Energy Technology Data Exchange (ETDEWEB)

Nacapricha, D. [Mahidol Univ., Bangkok (Thailand); Taylor, C. [John Moores Univ., Liverpool (United Kingdom)

1996-12-31

Studies have been performed on potassium-iodide-impregnated charcoals of the type used in the nuclear industry for trapping radioiodine released during nuclear fission. The effects of various parameters on the trapping efficiency of methyl iodide have been investigated. A variation in particle size within a bulk charcoal caused poor precision in K value measurements because of differences in surface area, pore volume, and bed density, leading to differences in the deposition of the impregnant. Precision is improved by sieving the charcoal to a narrower size because smaller particles have a higher porosity. This finding is supported by surface area and pore measurements. Two methods of impregnation are compared by measuring K values and the deposition of potassium iodide. Charcoal impregnated by rotary evaporation exhibits both higher K values and higher potassium iodide contents than sprayed charcoal. Two designs of spraying drum are compared: a drum with helical vanes allows more efficient deposition and more uniform distribution of impregnant than a drum with axial vanes. A decrease in the K value with increasing humidity correlates with the available surface area. A similar correlation exists between water content and available pore volume. Aging of potassium-iodide-impregnated charcoal, caused by the formation of oxygen complexes on the surface, is associated with significant falls in K value. K values of charcoals also can be restored to at least their original values by heat treatment in the absence of air. 12 refs., 6 figs., 1 tab.

Functional activity of human sodium/iodide symporter in tumor cell lines

International Nuclear Information System (INIS)

Petrich, T.; Knapp, W.H.; Poetter, E.

2003-01-01

Aim: The sodium/iodide symporter (NIS) actively transports iodide into thyrocytes. Thus, NIS represents a key protein for diagnosis and radioiodine therapy of differentiated thyroid cancer. Additionally, in the future the NIS gene may be used for cancer gene therapy of non-thyroid-derived malignancies. In this study we evaluated the functionality of NIS with respect to iodide uptake in a panel of tumor cell lines and compared this to gene transfer efficiency. Methods: A human NIS-containing expression vector and reporter-gene vectors encoding and beta;-Galactosidase- or EGFP were used for transient transfection of 13 tumor cell lines. Following transfection measurements of NIS-mediated radioiodide uptake using Na 125 I and of transfection efficiency were performed. The latter included β;-Galactosidase activity measurements using a commercial kit and observation by fluorescence microscopy for EGFP expression. Results: In contrast to respective parental cells, most NIS-transfected cell lines displayed high, perchlorate-sensitive radioiodide uptake. Differences in radioiodide uptake between cell lines apparently corresponded to transfection efficiencies, as judged from reporter-gene assays. Conclusion: With respect to iodide uptake we provide evidence that NIS is functional in different cellular context. As iodide uptake capacity appears to be well correlated to gene transfer efficiency, cell type-specific actions on NIS (e. g. post-translational modification such as glycosylation) are not inhibitory to NIS function. Our data support the promising role of NIS in cancer gene therapy strategies. (orig.)

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)

Experimental studies of caesium iodide aerosol condensation: theoretical interpretation

International Nuclear Information System (INIS)

Beard, A.M.; Benson, C.G.; Horton, K.D.; Buckle, E.R.

1990-07-01

Caesium iodide is predicted to be a significant source of fission product aerosols during the course of a severe accident in a pressurised water reactor (PWR). The nucleation and growth of caesium iodide aerosols have been studied using a plume chamber and the results compared with theoretical values calculated using the approach developed by Buckle for aerosol nucleation. The morphology of the particles was studied using scanning electron microscopy (SEM) and transmission optical microscopy (TOM), whilst the particle size distributions were determined from differential mobility (DMPS) and aerodynamic (APS) measurements. (author)

Method of preparation of technetium-99m labelled radio-diagnostic agents and a stable non radio-active carrier

International Nuclear Information System (INIS)

1975-01-01

A method of preparing improved technetium-99m labeled radiodiagnostic agents is described by reducing technetium-99m with stannous tartrate. Such radiodiagnostic agents are useful in scintigraphic examinations of the bone and lung

Determination of technetium-99 in environmental samples: A review

DEFF Research Database (Denmark)

Shi, Keliang; Hou, Xiaolin; Roos, Per

2012-01-01

Due to the lack of a stable technetium isotope, and the high mobility and long half-life, 99Tc is considered to be one of the most important radionuclides in safety assessment of environmental radioactivity as well as nuclear waste management. 99Tc is also an important tracer for oceanographic...... research due to the high technetium solubility in seawater as TcO4−. A number of analytical methods, using chemical separation combined with radiometric and mass spectrometric measurement techniques, have been developed over the past decades for determination of 99Tc in different environmental samples....... This article summarizes and compares recently reported chemical separation procedures and measurement methods for determination of 99Tc. Due to the extremely low concentration of 99Tc in environmental samples, the sample preparation, pre-concentration, chemical separation and purification for removal...

Technetium and neptunium reactions in basalt/groundwater systems

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.

1985-01-01

Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/l Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to 10 -6 mol/l and 8 x 10 -7 mol/l under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 references, 6 figures

Technetium and neptunium reactions in basalt/groundwater systems

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.; Florida State Univ., Tallahassee)

1984-01-01

Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/L Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to approx. 10 -6 mol/L and 8 x 10 -7 mol/L under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 refs., 6 tabs

An introduction to technetium-99m generators

International Nuclear Information System (INIS)

Abrashkin, S.

1984-02-01

The role played by technetium-99m generators in diagnostic medicine, their physical and chemical fundamentals and their main technical characteristics are discussed. This report is intended as a general introduction to a group of reports which summarize the work done on the development and production of the generators, and research on the chemical and physical aspects of the generator systems

Technetium removal: preliminary flowsheet options

International Nuclear Information System (INIS)

Eager, K.M.

1995-01-01

This document presents the results of a preliminary investigation into options for preliminary flowsheets for 99Tc removal from Hanford Site tank waste. A model is created to show the path of 99Tc through pretreatment to disposal. The Tank Waste Remediation (TWRS) flowsheet (Orme 1995) is used as a baseline. Ranges of important inputs to the model are developed, such as 99Tc inventory in the tanks and important splits through the TWRS flowsheet. Several technetium removal options are discussed along with sensitivities of the removal schemes to important model parameters

Immobilization of technetium and nitrate in cement-based materials

International Nuclear Information System (INIS)

Tallent, O.K.; McDaniel, E.W.; Del Cul, G.D.; Dodson, K.E.; Trotter, D.R.

1987-01-01

The leachabilities of technetium and nitrate wastes immobilized in cement-based grouts have been investigated. Factors found to affect the leachabilities include grout mix ratio, grout fluid density, dry solid blend composition, and waste concentration. 10 refs., 7 figs., 3 tabs

Monitoring of fluoride and iodide levels in drinking water using ion selective electrodes

International Nuclear Information System (INIS)

Ahmed, R.; Viqar-Un-Nisa; Hussain, M.; Tanwir, R.; Qureshi, S.A.

2004-01-01

Fluoride and iodide, the most important constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion-selective electrodes, spectrophotometry, titrimetry and coulometry etc; have been used and literature has been briefly reviewed. Ion-selective electrodes offer an efficient method for the measurement of the two halides and were mostly used during this work. Fabrication of these electrodes is briefly described. Comparison of results obtained by ion selective electrode and coulometry is given. Recoveries of the added fluoride ions from the samples were good. A large number of water samples from Rawalpindi-Islamabad area were analyzed for fluoride and iodide. Levels of fluoride and iodide from two main water reservoirs of Rawalpindi and Islamabad are reported before and after treatment. Both surface and ground water samples were analyzed and results are compared and discussed. Some samples from northern areas were also analyzed for iodide and fluoride and compared. Intake of fluoride and iodide from water of different areas is also compared. Water samples, which caused bone deformation in certain areas in Punjab due to excess fluoride, were also analyzed for fluoride and results are presented. (author)

Stable iodide doping induced by photonic curing for carbon nanotube transparent conductive films

Science.gov (United States)

Wachi, Atsushi; Nishikawa, Hiroyuki; Zhou, Ying; Azumi, Reiko

2018-06-01

Doping has become crucial for achieving stable and high-performance conductive transparent carbon nanotube (CNT) films. In this study, we systematically investigate the doping effects of a few materials including alkali metal iodides, nonmetal iodide, and metals. We demonstrate that photonic curing can enhance the doping effects, and correspondingly improve the conductivity of CNT films, and that such iodides have better doping effects than metals. In particular, doping with a nonmetal compound (NH4I) shows the largest potential to improve the conductivity of CNT films. Typically, doping with metal iodides reduces the sheet resistance (R S) of CNT films with 70–80% optical transmittances at λ = 550 nm from 600–2400 to 250–440 Ω/square, whereas doping with NH4I reduces R S to 57 and 84 Ω/square at 74 and 84% optical transmittances, respectively. Interestingly, such a doped CNT film exhibits only a slight increase in sheet resistance under an extreme environment of high temperature (85 °C) and high relative humidity (85%) for 350 h. The results suggest that photonic-curing-induced iodide doping is a promising approach to producing high-performance conductive transparent CNT films.

Vapor pressure of selected organic iodides

Czech Academy of Sciences Publication Activity Database

Fulem, M.; Růžička, K.; Morávek, P.; Pangrác, Jiří; Hulicius, Eduard; Kozyrkin, B.; Shatunov, V.

2010-01-01

Roč. 55, č. 11 (2010), 4780-4784 ISSN 0021-9568 R&D Projects: GA ČR GA203/08/0217 Institutional research plan: CEZ:AV0Z10100521 Keywords : vapor pressure * static method * organic iodides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.089, year : 2010

21 CFR 184.1265 - Cuprous iodide.

Science.gov (United States)

2010-04-01

... the following specific limitations: Category of food Maximum treatment level in food Functional use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cuprous iodide. 184.1265 Section 184.1265 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

Energy Technology Data Exchange (ETDEWEB)

Isherwood, D.

1985-04-01

Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10{sup -16} M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO{sub 4}{sup -}) when constrained by RuO{sub 2} is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10{sup -11} vs 4.5 x 10{sup -11} M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10{sup -8} M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO{sub 2}.2H{sub 2}O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10{sup -12} to 10{sup -16} M were apparently based on a technetium data base that did not include aqueous species other than TcO{sub 4}{sup -}. When TcO(OH){sub 2}{sup 0} is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code.

Application of the ruthenium and technetium thermodynamic data bases used in the EQ3/6 geochemical codes

International Nuclear Information System (INIS)

Isherwood, D.

1985-04-01

Based on a critical review of the available thermodynamic data, computerized data bases for technetium and ruthenium were created for use with the EQ3/6 geochemical computer codes. The technetium data base contains thermodynamic data for 8 aqueous species and 15 solids; 26 aqueous species and 9 solids were included in the ruthenium data base. The EQ3NR code was used to calculate solubility limits for ruthenium (8 x 10 -16 M) in ground water from Yucca Mountain, a potential nuclear waste repository site near the Nevada Test Site (NTS). The code confirmed the essentially unlimited solubility of technetium in oxidizing conditions, such as those that are believed to exist in the unsaturated zone at Yucca Mountain and the Cambric Nuclear event site at the NTS. Ruthenium migration observed from the Cambric site was evaluated. The solubility limit for ruthenium (as the aqueous species RuO 4 - ) when constrained by RuO 2 is approximately equal to the concentration of ruthenium found in the cavity ground water (i.e., 2.1 x 10 -11 vs 4.5 x 10 -11 M). Differences in ruthenium solubility limits between Yucca Mountain and Cambric are primarily due to differences in ground-water pH. Technetium solubility (3 x 10 -8 M) for moderately reducing conditions (Eh = -0.1 V) using the metastable oxide, TcO 2 .2H 2 O, as the solubility constraint is within the range of experimental values recently published in a study of technetium sorption on basalt. Previously published technetium solubilities of 10 -12 to 10 -16 M were apparently based on a technetium data base that did not include aqueous species other than TcO 4 - . When TcO(OH) 2 0 is included in the data base, the calculated values are much closer to the experimental results. Eh-pH diagrams were also generated for a variety of conditions using the SOLUPLOT code

Technetium: The First Radioelement on the Periodic Table

Science.gov (United States)

Johnstone, Erik V.; Yates, Mary Anne; Poineau, Frederic; Sattelberger, Alfred P.; Czerwinski, Kenneth R.

2017-01-01

The radioactive nature of technetium is discussed using a combination of introductory nuclear physics concepts and empirical trends observed in the chart of the nuclides and the periodic table of the elements. Trends such as the enhanced stability of nucleon pairs, magic numbers, and Mattauch's rule are described. The concepts of nuclear binding…

Tris(1,2-dimethoxyethane-κ2O,O′iodidocalcium iodide

Directory of Open Access Journals (Sweden)

Siou-Wei Ou

2012-02-01

Full Text Available In the title complex, [CaI(C4H10O23]I, the CaII atom is seven-coordinated by six O atoms from three 1,2-dimethoxyethane (DME ligands and one iodide anion in a distorted pentagonal–bipyramidal geometry. The I atom and one of the O atoms from a DME ligand lie in the axial positions while the other O atoms lie in the basal plane. The other iodide anion is outside the complex cation.

Technetium-99m labeled radiodiagnostic agents for liver and bone marrow scanning and method of preparation

International Nuclear Information System (INIS)

Molinski, V.J.; Peacock, F.R.

1977-01-01

An improved technetium-99m labeled colloid and method of preparation comprising reducing technetium-99m with stannous oxalate and stabilizing with sodium phytate are described. This radiodiagnostic agent is useful in the scintigraphic examination of the reticuloendothelial system, particularly the liver. In addition, by autoclaving this product with saline, it becomes a superior bone marrow scanning agent

Leaching of actinides and technetium from simulated high-level waste glass

International Nuclear Information System (INIS)

Bradley, D.J.; Harvey, C.O.; Turcotte, R.P.

1979-08-01

Leach tests were conducted using a modified version of the IAEA procedure to study the behavior of glass waste-solution interactions. Release rates were determined for Tc, U, Np, Pu, Am, Cm, and Si in the following solutions: WIPP B salt brine, NaCl (287 g/l), NaCl (1.76 g/1), CaCl 2 (1.66 g/l), NaHCO 3 (2.52 g/l), and deionized water. The leach rates for all elements decreased an order of magnitude from their initial values during the first 20 to 30 days leaching time. The sodium bicarbonate solution produced the highest elemental release rates, while the saturated salt brine and deionized water in general gave the lowest release. Technetium has the highest initial release of all elements studied. The technetium release rates, however, decreased by over four orders of magnitude in 150 days of leaching time. In the prepared glass, technetium was phase separated, concentrating on internal pore surfaces. Neptunium, in all cases except CaCl 2 solution, shows the highest actinide release rate. In general, curium and uranium have the lowest release rates. The range of actinide release rates is from 10 -5 to 10 -8 g/cm 2 /day. 25 figures, 7 tables

Potentiometric sensing of iodide using polymeric membranes of microwave stabilized β-AgI

International Nuclear Information System (INIS)

James, Dhanya; Rao, T. Prasada

2012-01-01

Highlights: ► Stable β-phase was obtained by post MW irradiation of AgI precipitate. ► Constructed ISEby dispersing stable β-AgI crystals in polyvinyl chloride. ► Designed iodide ISE exhibited wide linear range and fast response. ► Highly selective with selectivity factors less than 10 −6 . ► Successfully applied to natural waters, table salt and human urine samples. - Abstract: A polymer based heterogeneous ion selective electrode (ISE) membrane was fabricated for the potentiometric sensing of iodide. The sensing element used for the preparation of the ISE membrane was microwave stabilized β-AgI. Because microwave energy was found to be beneficial for causing hysteresis at the phase transition temperature of AgI, an attempt has been made to prepare stable and conductive β-AgI crystals by post microwave irradiation under high pressure. A conventionally precipitated AgI based ISE was also fabricated for comparative studies. The β-AgI based ISE could respond to a wide range of iodide concentrations (1 × 10 −8 to 1 M) within 60 s with a detection limit of 10 nM. The ISE gave stable response to iodide ions in a pH range of 2.0–8.0 and was highly selective in the presence of various interfering ions. The performance of the proposed iodide ISE in the analysis of natural and seawater samples was encouraging, and the determination of iodide in table salt and human urine samples was explained using the developed sensor.

Potentiometric determination of iodides in urine

International Nuclear Information System (INIS)

Gikolaev, B.A.; Primakova, L.N.; Rakhman'ko, E.M.

1996-01-01

Variants of potentiometric method: determination using a calibrations plot, the Gran method, and the double addition method are considered. The method of double additions of the test solution to the reference one is suggested as the most favorable method of determining iodides in urine under clinical laboratory conditions. Refs. 5, tabs. 2

Inclusion complexation of tetrabutylammonium iodide by cyclodextrins

Indian Academy of Sciences (India)

Biswajit Datta

Host-guest inclusion complex of an ionic solid (tetrabutyl ammonium iodide) with α- and β- cyclodextrin has been ... tions.2 CDs are cyclic oligomer of α-D-glucose having numerous of ... of locating at the interface of two phases (liquid–liquid.

Labelling of biological structures with technetium 99 m

International Nuclear Information System (INIS)

Bernardo Filho, M.

1988-01-01

The labelling of red blood cells (RBC) with technetium 99m ( 99m Tc) depends on several factors, as the stannous ion (Sn ++ ) concentration, the time and temperature of incubation, the anticoagulant utilized, the presence of plasma proteins (PP) and others. Although the blinding of 99m Tc with hemoglobin and PP are similar, they appear to have specific characteristics as demonstrated by precipitation with alcohol, acetone, trichloroacetic acid, hydrochloric acid and mercury chloride. The bacterial cultures labeled with Technetium- 99m , at optimal Sn ++ ion concentration, presents a large stability and their viability is not altered by this treatment. The electrophoretic mobility, the hydrophobicity, the cationized ferritin distribution and the adherence to human buccal epithelial cells are not modified either. The possibility of labelling with 99m Tc of planaria and cercariae of Schistossoma mansoni evaluative cycle increases the utilization of this radionuclide to an experimental level. The results described with the labelling of these biological structures with 99m Tc demonstrated that stable labeled and viable operations are obtained. (author)

Iodide behaviour in hard clay rocks under controlled physico-chemical conditions at different concentrations

International Nuclear Information System (INIS)

Frasca, B.; Savoye, S.; Wittebroodt, C.; Leupin, O.X.; Descostes, M.; Grenut, B.; Meier, P.; Michelot, J.L.

2010-01-01

Document available in extended abstract form only. With a half-life of 1.6 10 7 years, its high mobility and its potential to accumulate in the biosphere, iodine-129 is considered, from safety assessment calculations for radioactive waste repositories, to be one of the main radiological dose contributors. Based on the findings of previous studies, iodide, especially at low concentrations, seems to be migrating at a slower rate in clay rock than Cl-36. The cause of this retardation regarding the diffusion of iodide versus chloride is not yet understood but several hypotheses are point towards sorption on natural organic matter (NOM), pyrite or redox reactions. Oxidation of iodide would form IO 3 - which is known to have a higher sorption affinity on several soils and sediment samples than iodide. The present project aims at exploring the effect on the iodide behaviour of two parameters: (i) the initial concentration of iodide and (ii) the amount of NOM contained in the argillite samples. Such an investigation is carried out on Tournemire argillite by means of both batch and through-diffusion experiments. The main challenge is to exclude as much as possible the occurrence of any experimental artefact that could induce iodide uptake (oxygen contamination, dissolution/precipitation of carbonate phases). Regarding redox conditions and rock equilibrium, all the experiments were carried out under physico-chemical conditions as close as possible to those prevailing in field. Using a glove box with an atmosphere of N 2 /CO 2 (respectively 99.6% and 0.4%), we preserved the experiments from oxygen and maintained the calculated in-situ carbonate equilibrium. At first, four through-diffusion experiments with the non-sorbing tracers HTO and Cl-36 were performed to allow the diffusive parameters of each sample to be defined. Afterwards, iodide was injected in the diffusion cells at four different concentrations (10 -6 M to 10 -3 M). Thus, the comparison of the incoming fluxes of

Evaluation of optimal silver amount for the removal of methyl iodide on silver-impregnated adsorbents

International Nuclear Information System (INIS)

Park, G.I.; Cho, I.H.; Kim, J.H.; Oh, W.Z.

2001-01-01

The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver-impregnated zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver impregnation amount for the removal of methyl iodide at temperatures up to 300 deg. C. The degree of adsorption efficiency of methyl iodide on silver-impregnated adsorbent is strongly dependent on impregnation amount and process temperature. A quantitative comparison of adsorption efficiencies on three adsorbents in a fixed bed was investigated. The influence of temperature, methyl iodide concentration and silver impregnation amount on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It shows that the effective impregnation ratio was about 10wt%, based on the degree of silver utilization for the removal of methyl iodide. The practical applicability of silver-impregnated zeolite for the removal of radioiodine generated from the DUPIC process was consequently proposed. (author)

Transfer across the human gut of environmental technetium in lobsters (Homarus gammarus L.) from the Irish Sea

Energy Technology Data Exchange (ETDEWEB)

Hunt, G.J. [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT (United Kingdom)]. E-mail: g.j.hunt@cefas.co.uk; Young, A.K.; Bonfield, R.A. [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT (United Kingdom)

2001-03-01

Few data are available on the uptake by the human gut of the element technetium. Of current radiological interest in connection with discharges of technetium-99 in liquid discharges from BNFL, Sellafield, is uptake from European lobsters (Homarus gammarus), whose edible parts are known to concentrate technetium. In this study, a group of eight adult volunteers (six males and two females) ate samples of edible flesh from lobsters caught off the west Cumbrian coast and provided 24 h samples of urine and faeces for analysis. Detection of uptake from the gut by difference between intake and faecal measurements proved insensitive, suggesting a low value of the gut transfer factor (f{sub 1} value) of up to 0.1 with a maximum (two standard deviations) level of about 0.3. In urine, technetium was detectable at a relatively low level compared with the intakes, consistent with a low absorption across the gut. Values for f{sub 1} were derived with the aid of literature data for excretion following intravenous administration of technetium-95m as pertechnetate, and gave averaged data for f{sub 1} in the range 0.046 to 0.23. These results are in broad conformity with those derived from the faecal measurements, and suggest a lower value than the 0.5 used by ICRP. (author)

Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

Science.gov (United States)

Gong, Tingting; Zhang, Xiangru

2013-11-01

The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 μg/L as I for a 40 mL water sample (or 2.5 μg/L as I for an 80 mL water sample, or 1.25 μg/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared. Copyright © 2013 Elsevier Ltd. All rights reserved.

Behaviour of organic iodides under pwr accident conditions

International Nuclear Information System (INIS)

Alm, M.

1982-01-01

Laboratory experiments were performed to study the behaviour of radioactive methyl iodide under PWR loss-of-coolant conditions. The pressure relief equipment consisted of an autoclave for simulating the primary circuit and of an expansion vessel for simulating the conditions after a rupture in the reactor coolant system. After pressure relief, the composition of the CH 3 sup(127/131)I-containing steam-air mixture within the expansion vessel was analysed at 80 0 C over a period of 42 days. On the basis of the values measured and of data taken from the literature, both qualitative and quantitative assessments have been made as to the behaviour of radioactive methyl iodide in the event of loss-of-coolant accidents. (author)

Biogeochemical Controls on Technetium Mobility in Biogeochemical Controls on Technetium Mobility in FRC Sediments

International Nuclear Information System (INIS)

Lloyd, J.R.; McBeth, J.M.; Livens, F.R.; Bryan, N.D.; Ellis, B.; Sharma, H.; Burke, I.T.; Morris, K.

2004-01-01

Technetium-99 is a priority pollutant at numerous DOE sites, due to its long half-life (2.1 x 10 5 years), high mobility as Tc(VII) in oxic waters, and bioavailability as a sulfate analog. 99 Tc is far less mobile under anaerobic conditions, forming insoluble Tc(IV) precipitates. As anaerobic microorganisms can reduce soluble Tc(VII) to insoluble Tc(IV), microbial metabolism may have the potential to treat sediments and waters contaminated with Tc. Baseline studies of fundamental mechanisms of Tc(VII) bioreduction and precipitation (reviewed by Lloyd et al, 2002) have generally used pure cultures of metal-reducing bacteria, in order to develop conceptual models for the biogeochemical cycling of Tc. There is, however, comparatively little known about interactions of metal-reducing bacteria with environmentally relevant trace concentrations of Tc, against a more complex biogeochemical background provided by mixed microbial communities in the subsurface. The objective of this new NABIR project is to probe the site specific biogeochemical conditions that control the mobility of Tc at the FRC (Oak Ridge, TN). This information is required for the rational design of in situ bioremediation strategies for technetium-contaminated subsurface environments. We will use a combination of geochemical, mineralogical, microbiological and spectroscopic techniques to determine the solubility and phase associations of Tc in FRC sediments, and characterize the underpinning biogeochemical controls. A key strength of this project is that many of the techniques we are using have already been optimized by our research team, who are also studying the biogeochemical controls on Tc mobility in marine and freshwater sediments in the UK in a NERC funded companion study.

EPR investigations on technetium compounds

International Nuclear Information System (INIS)

Abram, U.; Munze, R.; Kirmse, R.; Stach, J.

1986-01-01

Stimulated by the widespread use of the isotope /sup 99m/Tc in the field of nuclear medicine, there has been a substantial growth of interest in the chemistry of this man-made element. A particular need emerges for analytical methods allowing solution investigations of coordination compounds of technetium with low substance use. Considering these facts, Electron Paramagnetic Resonance Spectroscopy (EPR) appears to be a very suitable method because only very small amounts of the compounds are needed (lower than 1 mg). The resulting spectra give information regarding the valence state, symmetry and bonding properties of the compounds under study

Immobilization and Limited Reoxidation of Technetium-99 by Fe(II)-Goethite

Energy Technology Data Exchange (ETDEWEB)

Um, Wooyong; Chang, Hyun-shik; Icenhower, Jonathan P.; Qafoku, Nikolla; Smith, Steven C.; Serne, R. Jeffrey; Buck, Edgar C.; Kukkadapu, Ravi K.; Bowden, Mark E.; Westsik, Joseph H.; Lukens, Wayne W.

2010-09-30

This report summarizes the methodology used to test the sequestration of technetium-99 present in both deionized water and simulated Hanford Tank Waste Treatment and Immobilization Plant waste solutions.

Preliminary study of the migration of technetium in soil under hydrous conditions

International Nuclear Information System (INIS)

Sisson, D.H.; MacLean, S.C.; Schulz, R.K.; Borg, R.J.

1979-01-01

The sorption of technetium compared to sodium, cesium, and strontium by a common agricultural soil was measured using a column method. As expected, no sorption of Tc occurred under conditions that substantially removed Na + , Cs + , and Sr ++ . High radioactivity levels were used to establish absorption profiles over six orders of magnitude of tracer concentration. Behavior of initially dry columns was compared with that of initially water-saturated columns; the results were not quantitatively different although there was a qualitative difference in the appearance of the profiles. Technetium tracked the moisture content of the column and hence migrated at the veloccity of the aqueous medium

Technetium and diazotrophic organisms: toxicity, localization, transfer factors

International Nuclear Information System (INIS)

Vandecasteele, C.M.; Delmotte, A.; Roucoux, P.; Hove, C. van

1982-01-01

Three diazotrophic organisms, together with one leguminous organism in symbiosis with one of them, were cultivated in the presence of various quantities of technetium, of which the localization, transfer factors and toxicity were studied in relation to the age of the organisms and their type of metabolism. The paper discusses the biochemical aspects of the results. (author)

Assessment of the Cast Stone Low-Temperature Waste Form Technology Coupled with Technetium Removal - 14379

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Rapko, Brian M.; Serne, R. Jeffrey; Westsik, Joseph H.; Cozzi, Alex; Fox, Kevin M.; Mccabe, Daniel J.; Nash, C. A.; Wilmarth, William R.

2014-03-03

The U.S. Department of Energy Office of Environmental Management (EM) is engaging the national laboratories to provide the scientific and technological rigor to support EM program and project planning, technology development and deployment, project execution, and assessment of program outcomes. As an early demonstration of this new responsibility, Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) were chartered to implement a science and technology program addressing low-temperature waste forms for immobilization of DOE aqueous waste streams, including technetium removal as an implementing technology. As a first step, the laboratories examined the technical risks and uncertainties associated with the Cast Stone waste immobilization and technetium removal projects at Hanford. Science and technology gaps were identified for work associated with 1) conducting performance assessments and risk assessments of waste form and disposal system performance, and 2) technetium chemistry in tank wastes and separation of technetium from waste processing streams. Technical approaches to address the science and technology gaps were identified and an initial sequencing priority was suggested. A subset of research was initiated in 2013 to begin addressing the most significant science and technology gaps. The purpose of this paper is to report progress made towards closing these gaps and provide notable highlights of results achieved to date.

Radiolysis of cesium iodide solutions at 35 and 85 deg C

International Nuclear Information System (INIS)

Lucas, M.

1981-09-01

An aqueous solution of cesium iodide was irradiated by the gamma rays from a cobalt 60 source with a dose rate of 0.4 Mrad/hr. At 35 deg C the iodide I - is oxidized in molecular iodine I 2 but at 85 deg C the iodate IO 3 - is obtained. The aim of this work is the study of aerosols behaviour released in accidental situation of a PWR in presence of steam [fr

The retention mechanism of technetium-99m-HM-PAO

DEFF Research Database (Denmark)

Neirinckx, R D; Burke, J F; Harrison, R C

1988-01-01

Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the b......Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation....... This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data...

Environmental behavior of technetium in soil and vegetation: implications for radiological impact assessment

International Nuclear Information System (INIS)

Hoffman, F.O.

1982-04-01

Significant radiological exposures have been estimated for hypothetical atmospheric releases of Tc-99 from gaseous diffusion facilities when vegetation-to-soil concentration ratios representative of laboratory experiments are substituted for generic default values assumed in current regulatory models. To test the relevancy of these laboratory ratios, field investigations were conducted to obtain measurements of the vegetation-to-soil concentration ratio for Tc-99 in samples collected near operating gaseous diffusion facilities and to observe the dynamic behavior of technetium in soil and vegetation following a single application of a sprayed solution of /sup 95m/TcO 4 - Comparison of observed field concentration ratios and calculated steady-state concentration ratios with ratios obtained from previous laboratory experiments indicates that concentration ratios obtained from field data are one to two orders of magnitude less than those obtained from the laboratory. Furthermore, a substantial accumulation of technetium in soil and vegetation may not occur over long periods of time, since concentrations of technetium in both environmental media were observed to decrease with time subsequent to initial application of /sup 95m/TcO 4 -

Review of technetium behavior in relation to nuclear waste disposal

International Nuclear Information System (INIS)

Paquette, J.; Reid, J.A.K.; Rosinger, E.L.J.

1992-05-01

This report contains available information which determine possible methods of the transfer of technetium element from waste disposal facilities to the biosphere. It also includes possible effects upon human beings and environment. 65 refs., 4 tabs., 3 figs

Carbamazepine (Tegretol) inhibits in vivo iodide uptake and hormone synthesis in rat thyroid glands

International Nuclear Information System (INIS)

Villa, S.M.; Alexander, N.M.

1987-01-01

Decreased serum concentrations of T3 and T4 occur in patients treated with the anticonvulsant drug carbamazepine (CBZ), but with rare exception, these patients remain euthyroid. The mechanism that accounts for diminished hormone levels is unknown, and our objective was to study the direct effect of CBZ on iodide uptake and hormone synthesis in thyroid glands of CBZ-treated and pair-fed control rats. Chronic ingestion (per os) of CBZ in male rats reduced the four hour thyroid 131I-iodide uptake by approximately 60%. This inhibition occurred after the animals had received sufficient CBZ to attain plasma CBZ concentrations of 0.8 microgram/ml. Continued treatment with CBZ ranging from 560 to 800 mg/kg/day for 14 days did not result in further inhibition of iodide uptake even though the plasma CBZ concentrations had increased 6-20 fold. No inhibition of iodide uptake was apparent when the animals initially received CBZ ranging from 40 to 152 mg/kg body weight for 22 days when there were no detectable levels of plasma CBZ. Overall growth rates of CBZ-treated rats were slightly (6-10%) less than the pair-fed control animals. Plasma T4 concentrations were reduced by 18% (p less than 0.05) in the CBZ-fed animals, while T3 concentrations were diminished by 53% (p less than 0.01). CBZ appeared to alter thyroidal iodide transport because the thyroid:plasma iodide ratios were decreased by 26% in the drug-treated rats. The distribution of radioiodine in thyroidal iodoamino acids was essentially the same in both groups of rats but the absolute quantities of radioiodine were more than 2.5 times greater in the control rats. CBZ failed to inhibit peroxidase-catalyzed iodide and guaiacol oxidation in vitro

Technetium-99 in lobsters from the western Irish sea

International Nuclear Information System (INIS)

Fegan, Mary

1999-05-01

Technetium-99, the most important radionuclide of technetium release to the environment, is a pure beta emitter with a half-life of 2.13 x 10(5) years. It behaves conservatively in seawater and is likely to remain available to biota for a long time. The dominant and most stable form of technetium in oxygenated seawater is the pertechnetate ion, Tco4. The principle source of radionuclide contamination of the Irish Sea has been the liquid waste discharges of low level radionuclide effluent from the spent nuclear fuel reprocessing plant at Sellafield on the Cumbria Coast. In 1994 the annual discharge authorization limit for 99Tc was increased from 10 TBq to 200 TBq. Lobster concentrates 99Tc to a high degree with concentration factors of 1x 10(3) reported in the literature. The mean 99Tc activity concentrations in lobsters caught close to Sellafield were reported to have risen by a factor of 20 in 2 years from 390 Bq/kg (wet weight) in 1993 to 8300 Bq/kg (wet weight) in 1995. This study was undertaken to determine the 99Tc activity concentration in lobsters from the western Irish Sea. Lobsters were collected from the east and north east coasts of Ireland over the period June 1997 to July 1998 and analysed using a radioanalytical method which was based on the anion-exchange seperation of technetium as pertechnetate. A gas-flow proportional counter was used to measure to 99Tc activity concentration in each sample. Technetium-99 activity concentrations were measured in the muscle from the tail, the right and the left claws and also in the green gland, the hepatopancreas and the cardiac fore-gut. The results of the measurements showed, as expected, that the 99Tc activity concentrations were not as high as those in the samples from the Cumbrian coast. The mean 99Tc activity concentrations, over the sampling period, in the tail, right and left claw muscles were 214, 124 and 136 BQ/kg (wet weight) respectively. The mean 99Tc activity concentrations in the green gland

One column method to prepare 11C-labelled methyl iodide

International Nuclear Information System (INIS)

Kovacs, Z.; Priboczki, E.

1999-01-01

A new method in which the [ 11 C]methyl iodide is prepared on one alumina column is presented. A high specific surface alumina column, previously impregnated with lithium aluminium hydride solution, was used for direct trapping from the target gas and reduction into radiocomplex. The complex was then reacted on this column with HI to form [ 11 C]methyl iodide. The use of one alumina column, instead of a freezing trap, reaction vessel and separate unit for iodination, simplifies the apparatus, shortens the synthesis time and is well suitable for automation. (K.A.)

Iodide-trapping defect of the thyroid

International Nuclear Information System (INIS)

Pannall, P.R.; Steyn, A.F.; Van Reenen, O.

1978-01-01

We describe a grossly hypothyroid 50-year-old woman, mentally retarded since birth. On the basis of her history of recurrent goitre, absence of 131 I neck uptake and a low saliva/plasma 131 I ratio, congenital hypothyroidism due to a defect of the iodide-trapping mechanism was diagnosed. Other family members studied did not have the defect

Preclinical evaluation of technetium 99m-labeled P1827DS for infection imaging and comparison with technetium 99m IL-8.

NARCIS (Netherlands)

Krause, S.; Rennen, H.J.J.M.; Boerman, O.C.; Baumann, S.; Cyr, J.E.; Manchanda, R.; Lister-James, J.; Corstens, F.H.M.; Dinkelborg, L.M.

2007-01-01

BACKGROUND: The technetium 99 m (99mTc)-radiolabeled, leukocyte-avid peptide-glycoseaminoglycan complex, [99mTc]P1827DS, has been synthesized as an improved infection/inflammation imaging agent to [99mTc]P483H (LeukoTect, Diatide). In a phase I/II clinical trail, [99mTc]P483H images were equivalent

Electrosorption of tetraalkylammonium ions on silver iodide

NARCIS (Netherlands)

Keizer, de A.

1981-01-01

The object of the present investigations was to study the ef fect of the adsorption of charged organic ions on electrically charged, solid-liquid interfaces. To that end, symmetrical quater nary ammonium ions were adsorbed on a silver iodide-electrolyte interface at various

21 CFR 520.763b - Dithiazanine iodide powder.

Science.gov (United States)

2010-04-01

... therapy for adult worms. (2) The drug is contraindicated in animals sensitive to dithiazanine iodide and...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

Energy Technology Data Exchange (ETDEWEB)

Holm, J.; Glaenneskog, H.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland))

2010-05-15

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

International Nuclear Information System (INIS)

Holm, J.; Glaenneskog, H.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.

2010-05-01

An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

Automation drying unit molybdenum-zirconium gel radioisotope production technetium-99M for nuclear medicine

International Nuclear Information System (INIS)

Chakrova, Y.; Khromushin, I.; Medvedeva, Z.; Fettsov, I.

2014-01-01

Full text : Since 2001 the Institute of Nuclear Physics of the Republic of Kazakhstan has began production of radiopharmaceutical based on technetium-99m from irradiated reactor WWR-K of natural molybdenum, which allows to obtain a solution of technetium-99m of the required quality and high volume activity. In 2013 an automated system is started, which is unique and urgent task is to develop algorithms and software in Python, as well as the manufacture of certain elements of technological systems for automated production

Behavior of technetium in paddy soils

International Nuclear Information System (INIS)

Yanagisawa, K.; Muramatsu, Y.; Ban-Nai, T.

1997-01-01

In order to understand the chemical form of soluble technetium in paddy soil and its availability to a rice plant, soil incubation and uptake experiments have been carried out using 95m Tc as a tracer. The chemical form of the soluble Tc was observed by gel chromatography and found not to be pertechnetate, but rather to be associated with soluble organic matter. An uptake experiment with rice seedlings using nutrient solution showed that this Tc-organic matter complex was less available than pertechnetate. (author)

Technetium-99 in the Irish marine environment

Energy Technology Data Exchange (ETDEWEB)

Smith, V.; Fegan, M.; Pollard, D.; Long, S.; Hayden, E.; Ryan, T.P

2001-07-01

Technetium-99 activity concentrations in seawater and biota from Irish coastal waters are presented. Time series measurements of {sup 99}Tc in seawater and Fucus vesiculosus from the western Irish Sea show that activity concentrations have increased in line with the increase in discharges of {sup 99}Tc from Sellafield. The peak in activity concentrations in both seawater and Fucus vesiculosus occurred in 1997 approximately two years after the peak in {sup 99}Tc discharges. The highest activity concentration recorded in Fucus vesiculosus showed a 29-fold increase over the mean concentration for the period 1988-1993. Technetium-99 activity concentrations were measured in fish, lobsters, prawns, mussels and oysters landed at major fishing ports on the east and northeast coasts of Ireland between 1996 and 1998. Concentration factors for {sup 99}Tc in the brown seaweed Fucus vesiculosus and certain species of fish, crustaceans and molluscs from the Irish Sea were estimated. In general, these concentration factors were higher than those in the literature which were derived from laboratory studies, but agreed well with values which were based on field studies. The mean committed effective doses to Irish typical and heavy seafood consumers due to {sup 99}Tc in the period 1996-1998 were 0.061 and 0.24 {mu}Sv, respectively.

Processes of adsorption/desorption of iodides and cadmium cations onto/from Ag(111

Directory of Open Access Journals (Sweden)

VLADIMIR D. JOVIĆ

2011-02-01

Full Text Available In this work, the adsorption/desorption processes of iodides and cadmium cations in the presence of iodides onto/from Ag(111 were investigated. It was shown that both processes were complex, characterized by several peaks on the cyclic voltammograms (CVs. By PeakFit analysis of the recorded CVs and subsequent fitting of the obtained peaks by the Frumkin adsorption isotherm, the interaction parameter (f and the Gibbs energy of adsorption (DGads for each adsorbed phase were determined. In the case of iodide adsorption, four peaks were characterized by negative values of f, indicating attractive lateral interaction between the adsorbed anions, while two of them possessed value of f < –4, indicating phase transition processes. The adsorption/desorption processes of cadmium cations (underpotential deposition – UPD of cadmium in the presence of iodide anions was characterized by two main peaks, each of them being composed of two or three peaks with negative values of f. By the analysis of charge vs. potential dependences obtained either from the CVs or current transients on potentiostatic pulses, it was concluded that adsorbed iodides did not undergo desorption during the process of Cd UPD, but became replaced by Cd ad-atoms and remained adsorbed on top of a Cd layer and/or in between Cd the ad-atoms.

Studies on the solvent extraction of technetium from thiocyanate solutions in mineral acids

International Nuclear Information System (INIS)

Ejaz, M.; Mamoon, A.M.

1988-01-01

Technetium-99m, separated from fission molybdenum-99 was studied as a component of liquid-liquid phase distribution equilibria. 5-(4-Pyridyl)nonane in a carrier diluent, benzene, was used to study the distribution of the nuclide from thermodynamically suitable aqueous phases of electrolytes with and without sterically receptive thiocyanate ions. Efficient extraction of the metal can be accomplished in a variety of aqueous phase compositions. The separation factors with respect to molybdenum, under certain experimental conditions, are fairly high. The data have been utilized to effect clean separations of technetium from molybdenum. (author) 39 refs.; 11 figs

Electrochemistry of silver iodide the capacity of the double layer at the silver iodide-water interface

NARCIS (Netherlands)

Lyklema, J.; Overbeek, J.Th.G.

1961-01-01

A method is described for obtaining differential double layer capacities on silver iodide. Especially the influence of the nature and concentration of indifferent electrolytes was investigated, viz., the nitrates of Li·, K·, Rb·, NH4·, H·, Tl·, Mg··, Ba··, Co··, Cd··, Pb··, La···, Th····, the

Diagnostic usefulness of technetium-99m (V) DMSA scintigraphy in cases of soft tissue tumors; In comparison with that of Ga-67 citrate scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Hisataka; Kotoura, Yoshihiko; Hanbara, Harumi; Hosono, Makoto; Yamamuro, Takao; Konishi, Junji (Kyoto Univ. (Japan). Faculty of Medicine)

1994-05-01

Technetium-99m (V) DMSA scintigraphy was performed in 76 patients with pathologically confirmed soft tissue diseases. In 56 patients, gallium-67 citrate scintigraphy was performed within two weeks after technetium-99m (V) DMSA scintigraphy. Significant uptake of technetium-99m (V) DMSA was found in all cases of sarcoma, metastatic carcinoma, progressive benignancy (extra-abdominal desmoid etc.) and granulomatous lesions, but was not found in cases of benign, solid tumors in the soft tissue (leiomyoma, neurinoma, lipoma etc.). In conclusion, it is not necessary to treat patients with soft tissue tumors in which technetium-99m (V) DMSA did not accumulate. Therefore, it can be stated that technetium-99m (V) DMSA scintigraphy is useful for the screening of malignant tumors. (author).

Electronic and optical properties of lead iodide

DEFF Research Database (Denmark)

Ahuja, R.; Arwin, H.; Ferreira da Silva, A.

2002-01-01

The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...

Recognition of reversible and irreversible myocardial injury by technetium pyrophosphate extraction kinetics

International Nuclear Information System (INIS)

Silva, R.; Chen, Y.F.; Sell, T.L.; Lowe, J.E.; Jones, R.H.

1987-01-01

The need for a more accurate method of detecting episodes of myocardial ischemia during cardiac operations, particularly during the ischemic arrest interval, prompted us to investigate the usefulness of measuring the active extraction of technetium pyrophosphate in identifying and quantitating ischemic injury. Twenty-four adult mongrel dogs were subjected to cardiopulmonary bypass, and normothermic global ischemia was induced by cross-clamping the proximal aorta. Technetium pyrophosphate (1 mCi) was injected through a standard cardioplegia line with normal saline, simulating administration of cardioplegic solution, upon placement of the aortic cross-clamp (time 0), at 15, 30, 45, and 60 minutes of global ischemia, and with the onset and completion of ischemic contracture. Radioactive counts were recorded over the heart at 1 second intervals, and the extraction fraction and half-time of clearance were calculated. The extraction fraction increased from 0.22 at time 0 to 0.58 at 15 minutes, 0.82 at 30 minutes, 0.85 at 45 minutes, and 0.91 at 60 minutes. The halftime increased from a baseline of 114 seconds (time 0) to a maximum of 321 seconds at 60 minutes of ischemia. The onset and completion of ischemic contracture showed a return toward baseline of both the extraction fraction and halftime of clearance, with an extraction fraction of 0.44 and 0.46 and a halftime of 135 and 133 seconds, respectively. These data clearly show that reversible myocardial injury increased the extraction and reduced the clearance of technetium pyrophosphate and that the magnitude of change related to the extent of injury. The progression to irreversible myocardial injury decreased the active extraction of technetium pyrophosphate. This simple procedure for real-time documentation of myocardial injury promises to provide easily obtainable endpoints of injury for use during cardiac operations in humans

Detection of pulmonary hemorrhage with technetium-labeled red cells

International Nuclear Information System (INIS)

Winzelberg, G.G.; Laman, D.; Sachs, M.; Miller, W.H.

1981-01-01

Noninvasive techniques to aid in the diagnosis of massive pulmonary hemoptysis would be helpful in guiding more-invasive procedures such as bronchial artery angiography, which carries a risk of transverse myelitis. A patient was studied with technetium-labeled red cells and successfully detected a site of intermittent hemorrhage from the lung

FY-2016 Methyl Iodide Higher NOx Adsorption Test Report

Energy Technology Data Exchange (ETDEWEB)

Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2016 under the Department of Energy (DOE) Fuel Cycle Technology (FCT) Program Offgas Sigma Team to further research and advance the technical maturity of solid sorbents for capturing iodine-129 in off-gas streams during used nuclear fuel reprocessing. Adsorption testing with higher levels of NO (approximately 3,300 ppm) and NO2 (up to about 10,000 ppm) indicate that high efficiency iodine capture by silver aerogel remains possible. Maximum iodine decontamination factors (DFs, or the ratio of iodine flowrate in the sorbent bed inlet gas compared to the iodine flowrate in the outlet gas) exceeded 3,000 until bed breakthrough rapidly decreased the DF levels to as low as about 2, when the adsorption capability was near depletion. After breakthrough, nearly all of the uncaptured iodine that remains in the bed outlet gas stream is no longer in the form of the original methyl iodide. The methyl iodide molecules are cleaved in the sorbent bed, even after iodine adsorption is no longer efficient, so that uncaptured iodine is in the form of iodine species soluble in caustic scrubber solutions, and detected and reported here as diatomic I2. The mass transfer zone depths were estimated at 8 inches, somewhat deeper than the 2-5 inch range estimated for both silver aerogels and silver zeolites in prior deep-bed tests, which had lower NOx levels. The maximum iodine adsorption capacity and silver utilization for these higher NOx tests, at about 5-15% of the original sorbent mass, and about 12-35% of the total silver, respectively, were lower than for trends from prior silver aerogel and silver zeolite tests with lower NOx levels. Additional deep-bed testing and analyses are recommended to expand the database for organic iodide adsorption and increase the technical maturity if iodine adsorption processes.

Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

International Nuclear Information System (INIS)

Perry, C. C.; Faradzhev, N. S.; Madey, T. E.; Fairbrother, D. H.

2007-01-01

The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons

Studies in technetium chemistry, Project 1: Evaluation of technetium acetylacetonates as potential cerebral blood flow agents, Project 2

International Nuclear Information System (INIS)

Jones, A.G.; Packard, A.B.; Treves, S.; Davison, A.

1990-01-01

Although the emphasis in our original submission was on N 2 S 2 and N 3 S coordinating ligands in technetium(V), we have now broadened the chemistry studies into areas that encompass new systems that allow the generation of neutral complexes. This change was based upon developments that have taken place in our basic chemistry studies that could bear on one of the original aims of this work, i.e., the design of complexes designed to penetrate cellular membranes and to remain trapped in target tissues. Among these topics are oxotechnetium(V) complexes containing amine and alcoholate ligands, coordination compounds containing the alternative technetium(V) nitrido core and the synthesis at macroscopic levels of a tetradentate ''umbrella'' ligand that successfully binds the metal. Basic studies with the original bisamide-bisthiol ligand system have continued with the identification of the products formed when aqueous solutions of the complex [TcO(ema)] - are acidified. This material is isolatable as yellow/brown crystals when HCl is added to the tetraphenylarsonium salt of the complex synthesized according to published procedures. Elemental analysis, FAB(+) mass spectrometry and 1 H NMR results were consistent with the formulation TcO(ema)H. Infrared spectra showed a dramatic shift in the Tc = O stretch to 966 cm -1 , as distinct from 945 cm -1 in the original complex

An iodine supplementation of tomato fruits coated with an edible film of the iodide-doped chitosan.

Science.gov (United States)

Limchoowong, Nunticha; Sricharoen, Phitchan; Techawongstien, Suchila; Chanthai, Saksit

2016-06-01

In general, the risk of numerous thyroid cancers inevitably increases among people with iodine deficiencies. An iodide-doped chitosan (CT-I) solution was prepared for dipping tomatoes to coat the fresh surface with an edible film (1.5 μm), thereby providing iodine-rich fruits for daily intake. Characterisation of the thin film was conducted by FTIR and SEM. Stability of the CT-I film was studied via water immersion at various time intervals, and no residual iodide leached out due to intrinsic interactions between the cationic amino group of chitosan and iodide ions. Moreover, the iodide supplement exhibited no effect on the antioxidant activity of tomatoes. The iodine content in the film-coated tomato was determined by ICP-OES. The tomato coating with 1.5% (w/v) CT-I contained approximately 0.4 μg iodide per gram fresh weight. In addition, the freshness and storability of iodine-doped tomatoes were also maintained for shelf-life concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

The sorption of uranium and technetium on bentonite, tuff and granodiorite

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Cowper, M.M.; Heath, T.G.; Tweed, C.J.

1995-01-01

A combined experimental and modeling study of the sorption of uranium and technetium on geological materials has been carried out as part of the PNC program to increase confidence in the performance assessment for a high-level radioactive waste (HLW) repository in Japan. Batch sorption experiments have been performed in order to study the sorption of uranium and technetium onto bentonite, tuff and granodiorite from both equilibrated seawater and de-ionized water under strongly-reducing and non-reducing conditions. A preliminary study of the sorption of uranium on mineral surfaces in granodiorite has also been undertaken using a nuclear microprobe. Mathematical modeling using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database has been carried out in order to interpret the results of the sorption experiments

Clinical usefulness of scintigraphy with 99mTechnetium phosphates in rhabdomyolysis

International Nuclear Information System (INIS)

Aizawa, Nobuyuki; Hara, Yoshikuni; Suzuki, Yutaka; Akashi, Tsunehiro; Kamei, Tetsumasa; Uchiyama, Fujio; Mitsui, Tamito; Yamazaki, Yuki.

1990-01-01

We performed bone scans with 99m Technetium phosphates in 15 cases of clinically suspected rhabdomyolysis admitted to Chigasaki Tokushukai Hospital. Whole body scans were performed within 5 days from the onset of illness or admission. Accumulation of the radioactivity in the skeletal muscle was revealed in 13 of the 15 cases and the involved muscle groups were visualized vividly. Etiologies of rhabdomyolysis were diverse, ranging from malignant syndrome to sepsis. Myocardial concentration was absent in all of the cases. Renal concentration of the isotope was seen in cases where the degree of rhabdomyolysis was higher and renal impairment was present. We conclude that 99m Technetium phosphate bone scan is useful in clinically suspected rhabdomyolysis as a diagnostic test and as a test to localize and quantitate the muscular involvement. (author)

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps.

Science.gov (United States)

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J; Han, Yu; Li, Jing

2017-09-07

Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH 3 I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag 0 @MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps

KAUST Repository

Li, Baiyan

2017-09-01

Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH3I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag0@MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

Energy Technology Data Exchange (ETDEWEB)

Palmer, C J, E-mail: carl.j.palmer@gmail.co [Department of Oceanography, University of Cape Town, 7701 (South Africa)

2010-08-15

Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

International Nuclear Information System (INIS)

Palmer, C J

2010-01-01

Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

Simultaneous detection of iodine and iodide on boron doped diamond electrodes.

Science.gov (United States)

Fierro, Stéphane; Comninellis, Christos; Einaga, Yasuaki

2013-01-15

Individual and simultaneous electrochemical detection of iodide and iodine has been performed via cyclic voltammetry on boron doped diamond (BDD) electrodes in a 1M NaClO(4) (pH 8) solution, representative of typical environmental water conditions. It is feasible to compute accurate calibration curve for both compounds using cyclic voltammetry measurements by determining the peak current intensities as a function of the concentration. A lower detection limit of about 20 μM was obtained for iodide and 10 μM for iodine. Based on the comparison between the peak current intensities reported during the oxidation of KI, it is probable that iodide (I(-)) is first oxidized in a single step to yield iodine (I(2)). The latter is further oxidized to obtain IO(3)(-). This technique, however, did not allow for a reasonably accurate detection of iodate (IO(3)(-)) on a BDD electrode. Copyright © 2012 Elsevier B.V. All rights reserved.

Sorption of technetium on composite chitosan-hydroxyapatite from aqueous solutions

International Nuclear Information System (INIS)

Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

2013-01-01

Biomaterials such as natural polymers (chitosan) and hydroxyapatite have an important application in material for bone replacement. Most of chitosan/hydroxyapatite composites are prepared by mixing hydroxyapatite particles with chitosan matrices. Another method of preparation of chitosan/hydroxyapatite composite is in-situ generation of nano-hydroxyapatite in chitosan matrix. The most common biomaterial used in the past years in hard tissue regeneration was hydroxyapatite, owing to its properties as biocompatibility, bioactivity, non-toxicity, non-immunogenicity etc. Chitosan is a polyaminosacharide, partially deacetylated product of chitin. Chitosan can be used in combination with other materials to enhance bone growth such as bone filling paste. The aims of this work were: the influence of the contact time on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of pH on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of foreign ions on sorption of pertechnate anions on chitosan/hydroxyapatite composites. The author concluded: the percentage of technetium sorption after 1 hour of contact time was > 97 %. In the initial pH range of 2.9-10.2, the percentage of technetium sorption on chitosan/hydroxyapatite composites CH/HA(A), CH/HA(B), CH/HA 30:70, ZCH was > 98 % and on CH/HA 50:50 was > 94%. The competition effect of Fe 2+ towards TcO 4 :- sorption is stronger than competition effect of other observed cations for all examined composites with the same weight ratio. The percentage of the technetium sorption was the same for all composites with the weight ratio of 30:70. (authors)

Investigation of antimony extraction from nitric acid solutions by tributyl phosphate

International Nuclear Information System (INIS)

Lakaev, V.S.; Smelov, V.S.

1988-01-01

The effect of iodide, hydrogen and pertechnetate ions on antimony extraction by tri-n-butyl phosphate (TBP) from aqueous nitric acid solutions under irradiated nuclear fuel processing is investigated at room temperature. The coefficients of antimony distribution are shown to increase at the presence of technetium ions 2-3 times and iodine ions - 100 and more times. Variation of hydrogen ion concentration does not affect antimony extraction. The schemes of the mechanism of antimony extraction at the pressence of iodide and pertechnetate ions are presented. Compositions of the formed compounds are given

Effects of concurrent drug therapy on technetium /sup 99m/Tc gluceptate biodistribution

International Nuclear Information System (INIS)

Hinkle, G.H.; Basmadjian, G.P.; Peek, C.; Barker, K.K.; Ice, R.D.

1982-01-01

Drug interactions with /sup 99m/Tc gluceptate resulting in altered biodistribution were studied using chart review and animal tests. Charts of nine patients who had abnormal gallbladder uptake of technetium /sup 99m/Tc gluceptate during a two-year period were reviewed to obtain data such as concurrent drug therapy, primary diagnosis, and laboratory values. Adult New Zealand white rabbits were then used for testing the biodistribution of technetium /sup 99m/Tc gluceptate when administered concurrently with possibly interacting drugs identified in the chart review--penicillamine, penicillin G potassium, penicillin V potassium, acetaminophen, and trimethoprim-sulfamethoxazole. Chart review revealed no conclusive patterns of altered biodistribution associated with other factors. The data did suggest the possibility that the five drugs listed above might cause increased hepatobiliary clearance of the radiopharmaceutical. Animal tests showed that i.v. penicillamine caused substantial distribution of radioactivity into the gallbladder and small bowel. Minimally increased gallbladder radioactivity occurred when oral acetaminophen and trimethoprim-sulfamethoxazole were administered concurrently. Oral and i.v. penicillins did not increase gallbladder activity. Penicillamine may cause substantial alteration of the biodistribution of technetium /sup 99m/Tc gluceptate

Determination of technetium-99 in environmental samples: A review

International Nuclear Information System (INIS)

Shi Keliang; Hou Xiaolin; Roos, Per; Wu Wangsuo

2012-01-01

Highlights: ► The source term, physicochemical properties, environmental distribution and behaviour of 99 Tc are presented. ► Various sample pre-treatment and pre-concentration techniques of technetium are discussed. ► Chemical separation and purification techniques for 99 Tc in environmental samples are reviewed. ► Measurement techniques for 99 Tc in environmental level and automated analytical methods are reviewed. ► The reported analytical methods of 99 Tc are critically compared to provide overall information. - Abstract: Due to the lack of a stable technetium isotope, and the high mobility and long half-life, 99 Tc is considered to be one of the most important radionuclides in safety assessment of environmental radioactivity as well as nuclear waste management. 99 Tc is also an important tracer for oceanographic research due to the high technetium solubility in seawater as TcO 4 − . A number of analytical methods, using chemical separation combined with radiometric and mass spectrometric measurement techniques, have been developed over the past decades for determination of 99 Tc in different environmental samples. This article summarizes and compares recently reported chemical separation procedures and measurement methods for determination of 99 Tc. Due to the extremely low concentration of 99 Tc in environmental samples, the sample preparation, pre-concentration, chemical separation and purification for removal of the interferences for detection of 99 Tc are the most important issues governing the accurate determination of 99 Tc. These aspects are discussed in detail in this article. Meanwhile, the different measurement techniques for 99 Tc are also compared with respect to advantages and drawbacks. Novel automated analytical methods for rapid determination of 99 Tc using solid extraction or ion exchange chromatography for separation of 99 Tc, employing flow injection or sequential injection approaches are also discussed.

Modelling iodide – iodate speciation in atmospheric aerosol: Contributions of inorganic and organic iodine chemistry

Directory of Open Access Journals (Sweden)

S. Pechtl

2007-01-01

Full Text Available The speciation of iodine in atmospheric aerosol is currently poorly understood. Models predict negligible iodide concentrations but accumulation of iodate in aerosol, both of which is not confirmed by recent measurements. We present an updated aqueous phase iodine chemistry scheme for use in atmospheric chemistry models and discuss sensitivity studies with the marine boundary layer model MISTRA. These studies show that iodate can be reduced in acidic aerosol by inorganic reactions, i.e., iodate does not necessarily accumulate in particles. Furthermore, the transformation of particulate iodide to volatile iodine species likely has been overestimated in previous model studies due to negligence of collision-induced upper limits for the reaction rates. However, inorganic reaction cycles still do not seem to be sufficient to reproduce the observed range of iodide – iodate speciation in atmospheric aerosol. Therefore, we also investigate the effects of the recently suggested reaction of HOI with dissolved organic matter to produce iodide. If this reaction is fast enough to compete with the inorganic mechanism, it would not only directly lead to enhanced iodide concentrations but, indirectly via speed-up of the inorganic iodate reduction cycles, also to a decrease in iodate concentrations. Hence, according to our model studies, organic iodine chemistry, combined with inorganic reaction cycles, is able to reproduce observations. The presented chemistry cycles are highly dependent on pH and thus offer an explanation for the large observed variability of the iodide – iodate speciation in atmospheric aerosol.

Biomedical tracers: technetium-99 m complexing sulfur polydentate ligands

International Nuclear Information System (INIS)

Bendennoune, A.

1994-01-01

Cyclic and acyclic tetra sulfur ligands have been synthesized and some of them have been labelled with technetium-99m. These works have two different aims: 1- Development of methods permitting to obtain easily potential technetium complexing sulfur polydentate chelates. 2- Research of positive and neutral complexes of this metal likely to replace thalium-201 in the coronary flow estimation and [TcO-HMPAO] sup 0 complex in the cerebral scintigraphy, respectively. In this work, first, different ways for obtaining dithioetherdithiols and cyclic tetrathioethers containing functional groups have been carried out, then complexation of the core of nitrutechnetium (TcN) sup 2+ at tracers scale, by dithioetherdithiols, using exchange reaction with [sup 9 sup 9 sup m TcNCl sub 4 ] sup - ion complex or sup 99 sup m TcN Cl sub 2 [P(CH sub 2 CH sub 2 CN) sub 3 ] sub 2 has been studied. Finally, biological distribution in swiss mouse of these technetiated complexes has been studied. 135 refs., 30 figs., 13 tabs. (F.M.)

Analysis of americium, plutonium and technetium solubility in groundwater

International Nuclear Information System (INIS)

Takeda, Seiji

1999-08-01

Safety assessments for geologic disposal of radioactive waste generally use solubilities of radioactive elements as the parameter restricting the dissolution of the elements from a waste matrix. This study evaluated americium, plutonium and technetium solubilities under a variety of geochemical conditions using the geochemical model EQ3/6. Thermodynamic data of elements used in the analysis were provided in the JAERI-data base. Chemical properties of both natural groundwater and interstitial water in buffer materials (bentonite and concrete) were investigated to determine the variations in Eh, pH and ligand concentrations (CO 3 2- , F - , PO 4 3- , SO 4 2- , NO 3 - and NH 4 + ). These properties can play an important role in the complexation of radioactive elements. Effect of the groundwater chemical properties on the solubility and formation of chemical species for americium, plutonium and technetium was predicted based on the solubility analyses under a variety of geochemical conditions. The solubility and speciation of the radioactive elements were estimated, taking into account the possible range of chemical compositions determined from the groundwater investigation. (author)

Solvent effect on the rate and equilibrium of reaction between 10-phenylphenoxarsine and methyl iodide

International Nuclear Information System (INIS)

Gavrilov, V.I.; Gumerov, N.S.; Rakhmatullin, R.R.

1990-01-01

Effect of solvent nature on nucleophilic capacity of three-coordinated arsenic and the equilibrium state of 10-phenylphenoxarsine (PA) reaction with methyl iodide are studied. Kinetic investigations are carried out by the conductometry at 24,35,45 deg C. It is established that quaternization of PA with methyl iodide when substituting a solvent (ketone for alcohol) increases 3-14 times with simultaneous growth of the activation energy value. When transforming from aprotic solvents to protic ones PA interaction equilibrium with methyl iodide shifts to the side of arsonic salt formation

Synthesis and evaluation of iodide uptake inhibitors in thyroid gland

International Nuclear Information System (INIS)

Lacotte, Pierre

2012-01-01

This work was intended to discover small organic molecules acting as iodide uptake inhibitors in thyroid cells. These compounds can indeed be derivatized into biochemical probes for further characterization of proteins involved in iodide transport mechanisms. On the long term, these inhibitors also appear as attractive drug candidates for treatment of thyroid pathologies or radioprotection against iodine isotopes. A similar strategy was adopted for both of the two inhibitor families. First, we synthesized a chemical library of around 100 analogues; we measured their IC50 against iodide uptake in FRTL-5 cells to get structure-activity relationships. Absolute configuration of stereo-genic centers was also investigated, and a preferential stereochemistry was found to be responsible for activity. From this basis, around twenty 'second-generation' analogues were synthesized by combining fragments contributing to biological activity. Biological evaluation indicated that nine were very potent inhibitors, with IC50 ≤ 6 nM and satisfying physicochemical properties required for drug candidates. Finally, one photoactivatable biotinylated probe was developed in each family and used for photoaffinity labeling. Several specifically labeled proteins are still under identification and constitute new potential therapeutic targets. (author)

The method of determination of micro quantities of labelled iodide in Na125 I carrier free solution

International Nuclear Information System (INIS)

Kholbaev, A.Kh.; Shilin, E.A.

1996-01-01

The analytical method was elaborated with the purpose to increase detection limit and radiation safety of labelled iodide determination. The method includes oxidation of iodide by iodate in diluted sulphur acid solution with molar concentration 0,03-0,04/moles/litre at molar ratio of iodide to iodate I - :IO - 3 1:12,5. The extraction of I 2 produced is done by toluene. (author)

Evaluation of reflux oesophagitis with technetium-99m-labelled ...

African Journals Online (AJOL)

Sucralfate binds with denuded protein to form a stable complex to protect the damaged mucosa. By utilising this property, technetium-99m-labelled sucraJfate can be used to demonstrate ulceration in the upper gastro-intestinal tract. Aim: The aim of this study was to evaluate 99mTc-labelled sucralfate in the diagnosis of ...

Membrane-based separation technologies for cesium, strontium, and technetium

International Nuclear Information System (INIS)

Kafka, T.

1996-01-01

This work is one of two parallel projects that are part of an ESP task to develop high-capacity, selective, solid extractants for cesium, strontium, and technetium from nuclear wastes. In this subtask, Pacific Northwest National Laboratory (PNNL) is collaborating with 3M, St. Paul, Minnesota, working in cooperation with IBC Advanced Technologies, American Fork, Utah

Study on the Electrochemical Behavior of Iodide at Platinum Electrode in Potassium Chlorate Solution

Energy Technology Data Exchange (ETDEWEB)

Jung, Sang Hyuk; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Radioactive iodine-131, is one of the most hazardous fission products which could be released from fuels of nuclear reactors during the severe accident of nuclear power plants. Due to its high radioactivity, high fission yield (2.8%) and hazardous biological effects, the behavior of iodine has been taken interests in many research groups. Iodine is known to be released from the fuels as a cesium iodide form, CsI. And, as nuclear fuels are mostly placed in the water pool, it is easily dissolved in the water after released from the fuels. In water, iodide anion could be oxidized into molecular iodine. As the molecular iodine is a volatile species and the oxidizing rate is affected by many environmental facts such as pH, radiolysis products and temperature, the oxidation reaction of the iodide ion has been considered as an important chemical reaction related to the severe accident of nuclear power plants In present work, the electrochemical behavior of iodide anion was observed by using cyclic voltammetric technique in potassium chlorate solutions. We observed two different oxidation waves in the oxidation potential region. From the comparison with the previous reported results, one is regarded as the oxidation of iodide into molecular iodine. The other is evaluated to be the formation of high-valent iodine-containing compounds

Gamma-ray radiolysis of methyl iodide in air, in presence of water vapor

International Nuclear Information System (INIS)

Aubert, F.

2002-03-01

This work aims at modelling the processes involved in gamma-radiolysis of methyl iodide diluted in air in presence of steam. It is to determine quantitative and qualitative information, to quantify the importance of the organic iodides destruction in case of a nuclear reactor accident. The main data for radiochemistry and iodine compounds (I x O y and INO x ) formation were reviewed and analysed. Literature data about air products radiolysis reactivity towards I 2 and CH 3 I were used to develop a mechanistic model for methyl iodide destruction in the gas phase under gamma irradiation. An ab initio study was realised for a better understanding of atomic nitrogen ( 4 S and 2 D) reactivity towards CH 3 I. The model was tested on the available experimental data and constitute a way to investigate the main processus involved in methyl iodide destruction. For the low CH 3 I concentrations, about 10 -7 - 10 -8 mol.dm -3 , N and e - are mainly responsible for the destruction. I 2 O 4 (highest iodine oxide in the model) and IONO 2 are the main resulting iodinated' compounds. (author)

A portable multi-syringe flow system for spectrofluorimetric determination of iodide in seawater.

Science.gov (United States)

Frizzarin, Rejane M; Aguado, Enrique; Portugal, Lindomar A; Moreno, Daniel; Estela, José M; Rocha, Fábio R P; Cerdà, Victor

2015-11-01

A miniaturized analyzer encompassing a poly(methyl methacrylate) chip with integrated spectrofluorimetric detection and solutions propelling by a multi-syringe module is proposed. Iodide was determined through its catalytic effect on the reaction between Ce(IV) and As(III). Matrix isopotential synchronous fluorescence was explored to set the excitation and emission wavelengths. A two-level full factorial design allowed to evaluate the significance of variables (Ce(IV), As(III) and H2SO4 concentrations) and their interaction effects in the experimental domain. A Doehlert Matrix was applied to identify the critical values. The optimized procedure showed a linear response from 1 to 100 μg L(-1) (S=53.7+2.61C, in which S is the net fluorescence and C is iodide concentration in μg L(-1)). Detection limit, coefficient of variation (n=6) and sampling rate were estimated at 0.3 μg L(-1), 0.8% and 20 h(-1), respectively. Recoveries within 90-117% were estimated for iodide spiked to seawater samples. The proposed procedure stands out because of the portability, robustness, and simplicity for in-field analysis of iodide in seawater. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of iodide on glucose oxidation and 32P incorporation into phospholipids stimulated by different agents in dog thyroid slices

International Nuclear Information System (INIS)

Tseng, F.Y.; Rani, C.S.; Field, J.B.

1989-01-01

Since iodide (I-) inhibits TSH stimulation of cAMP formation, which mediates most of the effects of the hormone, it has been assumed that this accounts for the inhibitory action of iodide on the thyroid. However, TSH stimulation of 32P incorporation into phospholipids and stimulation of thyroid metabolism by other agonists, such as carbachol, phorbol esters, and ionophore A23187, is not cAMP mediated. The present studies examined the effect of iodide on stimulation of glucose oxidation and 32P incorporation into phospholipids by TSH and other agonists to determine if the inhibition of cAMP formation was responsible for the action of iodide. Preincubation of dog thyroid slices for 1 h with iodide (10(-4) M) inhibited TSH-, (Bu)2cAMP-, carbachol-, methylene blue-, 12-O-tetradecanoyl phorbol-13-acetate-, ionophore A23187-, prostaglandin E1-, and cholera toxin-stimulated glucose oxidation. I- also inhibited the stimulation by TSH, 12-O-tetradecanoyl phorbol-13-acetate, carbachol, and ionophore A23187 of 32P incorporation into phospholipids. The inhibition was similar whether iodide was added 2 h before or simultaneously with the agonist. I- itself sometimes stimulated basal glucose oxidation, but had no effect on basal 32P incorporation into phospholipids. The effects of iodide on basal and agonist-stimulated thyroid metabolism were blocked by methimazole (10(-3) M). When dog thyroid slices were preloaded with 32PO4 or [1-14C]glucose, the iodide inhibition of agonist stimulation disappeared, suggesting that the effect of iodide involves the transport process. In conclusion, I- inhibited stimulation of glucose oxidation and 32P incorporation into phospholipids by all agonists, indicating that the effect is independent of the cAMP system and that iodide autoregulation does not only involve this system. Oxidation and organification of iodide are necessary for the inhibition

Diffusion of iodine and Technetium-99 through waste encasement concrete and unsaturated soil fill material

International Nuclear Information System (INIS)

Mattigod, Shas V.; Whyatt, Greg A.; Serne, R. JEFFREY; Wood, Marcus I.; Hanchar, John M.; Stores-Gascoyne, Simcha; Lauren Browning

2004-01-01

An assessment of long-term performance of low level waste-enclosing cement grouts requires diffusivity data for radionuclide species such as, 129I and 99Tc. The diffusivity of radionuclides in soil and concrete media was collected by conducting soil-soil and concrete-soil half-cell experiments. The soil diffusivity coefficients for iodide were 7.03 x 10-8 cm2/s and 2.42 x 10-7 cm2/s for soils at 4% and 7% moisture contents, respectively. Iodide diffusivity in soil is a function of moisture content and is about an order of magnitude slower at lower moisture content. The soil diffusivity coefficients for 99Tc were 5.89 ± 0.80 x 10-8 cm2/s (4% moisture content) and 2.04 ± 0.57 x 10-7 cm2/s (7% moisture content), respectively. The soil diffusivity of iodide and 99Tc were similar in magnitude at both water contents, indicating that these ions have similar diffusion mechanisms in unsaturated coarse-textured Hanford soil. The diffusivity of iodide in concrete ranged from 2.07 x 10-14 cm2/s (4% soil moisture content) to 1.31 x 10-12 cm2/s (7% soil moisture content), indicating that under unsaturated soil moisture conditions, iodide diffusivity is highly sensitive to changing soil moisture conditions. Depending on the soil moisture content, the diffusivity of 99Tc in concrete ranged from 4.54 x 10-13 cm2/s to 8.02 x 10-12 cm2/s. At 4% soil moisture content, iodide diffused about 20 times more slowly than 99Tc, and at 7% soil moisture content, iodide in concrete diffused about 6 times slower than 99Tc

Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model.

Science.gov (United States)

Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming

2015-05-01

Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n = 12). Rabbits in the control group were injected with sterile saline (n = 12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4 hours after injection of technetium-99m-labeled annexin V (150 MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ± 0.29 in the early phase and 2.19 ± 0.34 in the delay phase, both of which were significantly higher than those of the control group (P = 0.03 and P = 0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.

3.2. Antibacterial activity of ethynyl-piperidol polymers and their three-iodides

International Nuclear Information System (INIS)

Khalikov, D.Kh.

2012-01-01

The antibacterial activity of ethynyl-piperidol polymers and their three-iodides was studied. The antibacterial films based on iodine with copolymer N-vinyl pyrrolidone, methylmethacrylate and butyl acrylate were obtained. It was found that samples containing 9-10% of iodine in copolymer have the antiseptic properties. The antibacterial properties of three-iodides grafted nitrogen containing polymers with cellulose fibrous materials were considered. The membrane-active properties of homo- and copolymers of ethynyl piperidol derivatives were considered as well.

3. Congress of the SA Society of nuclear medicine: Technetium-99m technology

International Nuclear Information System (INIS)

Beyers, M.

1988-08-01

The Atomic Energy Corporation of SA Limited have been engaged in the manufacture of radioisotopes since 1967, shortly after the SAFARI-1 reactor at Pelindaba was commissioned. Since then the use of radioisotopes in South Africa has grown rapidly and at present 95% of the in vivo diagnostic radioisotopes (radiopharmaceuticals) utilized in nuclear medicine are manufactured locally. Because radioisotopes are applied mainly in sophisticated chemically or mechanically processed forms, production requires not only a skilled production team, but also the appropriate facilities for the manufacture of high-quality products which comply with the necessary safety standards. Compliance with such standards is especially important for the routine production of radiopharmaceuticals for use in nuclear medicine. Over the past 20 years technetium-99m has achieved a dominant position among the diagnostic tools in modern nuclear medicine.The scope of nuclear medicine is expanding continuously and its future lies primarily in the development of new organspecific technetium-99m radiodiagnostic agents. Many improvements and changes have been made to Tc-99m generators, the major source of Tc-99m, since they were introduced to nuclear medicine in the late 1950's. The new Peltek-F sterile Tc-99m generator developed by the Isotope Production Centre is a symbol of progress made. In order to commemorate the launching of the new Peltek-F technetium-99m generator during August 1988 it was decided to publish six papers that were presented at the Third Congress of the Society of Nuclear Medicine held at Bloemfontein during the period 15 - 17 August 1988 by members of the Isotope Production Centre. This will serve as a useful reference on various aspects of technetium-99m technology and will stimulate the use of this product as well as new research in this field

Mechanistic aspects of ingested chlorine dioxide on thyroid function: impact of oxidants on iodide metabolism

International Nuclear Information System (INIS)

Bercz, J.P.; Jones, L.L.; Harrington, R.M.; Bawa, R.; Condie, L.

1986-01-01

Toxicological studies dealing with recent findings of health effects of drinking water disinfectants are reviewed. Experiments with monkeys and rodents indicate that the biological activity of ingested disinfectants is expressed via their chemical interaction with the mucosal epithelia, secretory products, and nutritional contents of the alimentary tract. Evidence exists that a principal partner of this redox interaction is the iodide of nutritional origin that is ubiquitous in the gastrointestinal tract. Thus the observation that subchronic exposure to chlorine dioxide (ClO 2 ) in drinking water decreases serum thyroxine levels in mammalian species can be best explained with changes produced in the chemical form of the bioavailable iodide. Ongoing and previously reported mechanistic studies indicate that oxidizing agents such as chlorine-based disinfectants oxidize the basal iodide content of the gastrointestinal tract. The resulting reactive iodine species readily attaches to organic matter by covalent bonding. Evidence suggests that the extent to which such iodinated organics are formed is proportional to the magnitude of the electromotive force and stoichiometry of the redox couple between iodide and the disinfectant. Because the extent of thyroid uptake of the bioavailable iodide does not decrease during ClO 2 ingestion, it seems that ClO 2 does not cause iodide deficiency of sufficient magnitude to account for the decease in hormonogenesis. Absorption of one or more of iodinated molecules, e.g., nutrient, hormones, or cellular constituents of the alimentary tract having thyromimetic or thyroid inhibitory properties, is a better hypothesis for the effects seen

Horizontal Ampoule Growth and Characterization of Mercuric Iodide at Controlled Gas Pressures for X-Ray and Gamma Ray Spectrometers

International Nuclear Information System (INIS)

Douglas, S.; McGregor Elsa; Ariesanti Bridget Corcoran

2004-01-01

The project developed a new method for producing high quality mercuric iodide crystals of x-ray and gamma spectrometers. Included are characterization of mercuric iodide crystal properties as a function of growth environment and fabrication and demonstration of room-temperature-operated high-resolution mercuric iodide spectrometers

Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

Energy Technology Data Exchange (ETDEWEB)

Hays, M.T.; Broome, M.R.; Turrel, J.M.

1988-06-01

A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in the euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4.

Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

International Nuclear Information System (INIS)

Hays, M.T.; Broome, M.R.; Turrel, J.M.

1988-01-01

A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in the euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4

Electronic properties and Compton profiles of silver iodide

Indian Academy of Sciences (India)

We have carried out an extensive study of electronic properties of silver iodide in - and -phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented ...

Developments in mercuric iodide gamma ray imaging

Energy Technology Data Exchange (ETDEWEB)

Patt, B E; Beyerle, A G; Dolin, R C; Ortale, C [EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations

1989-11-01

A mercuric iodide (HgI{sub 2}) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented. (orig.).

Preoperative localization of parathyroid adenomas by technetium and thallium double-labeling scintigraphy. Difficulties linked to associated thyroid lesions

International Nuclear Information System (INIS)

Valensi, P.; Attali, J.R.; Sebaoun, J.; Bedig, G.; Paycha, F.; Tellier, P.; Vulpillat, M.; Sarfati, E.; Dubost, C.

1989-01-01

Technetium and thallium double-labeling scintigraphy with image subtraction was carried out on 63 patients suspected of having primary hyperparathyroidism, with or without thyroid involvement. Forty-four patients had a normal thyroid image with technetium. The positive foci located by double-labeling in patients who were to undergo surgery always coincided with parathyroid adenoma. In the 16 cases where the initial diagnosis of hyperparathyroidism was not substantiated, the double-labeling test was normal. Thus for these 44 patients, scintigraphy sensitivity was 75% and specificity was 100%. Nineteen patients had an abnormal thyroid image with technetium. In 7 cases, image subtraction following double-labeling yielded uninterpretable data. In 12 other patients, the positive foci located outside the thyroid by double-labeling coincided with a parathyroid adenoma, whereas this was true for only one patient whose positive foci were located inside the thyroid; a parathyroid adenoma was not detected preoperatively in 4 patients. This double-labeling test is thus useful in locating parathyroid adenomas when technetium scintigraphy of the thyroid is normal; when it is abnormal, double-labeling is advantageous only in cases of extrathyroid foci [fr

Synergistic Effect of Azadirachta Indica Extract and Iodide Ions on the Corrosion Inhibition of Aluminium in Acid Media

Energy Technology Data Exchange (ETDEWEB)

Arab, S. T.; Al- Turkustani, A. M.; Al- Dhahiri, R. H. [King Abd El- Aziz University, Jeddah (Saudi Arabia)

2008-06-15

The synergistic action caused by iodide ions on the corrosion inhibition of aluminium (Al) in 0.5 M HCl in the presence of Azadirachta Indica (AZI) plant extract has been investigated using potintiodynamic polarization and impedance techniques. It is found that AZI extract inhibits the corrosion of aluminium in 0.5 M HCl. The inhibition efficiency increases with the increase in AZI extract concentration, until 24% v/v of AZI extract, then Inh.% is decreased with father increase in AZI extract concentration. The adsorption of this extract in the studied concentration is found to obey Frewendlish adsorption isotherm. The addition of iodide ions enhances the inhibition efficiency to a considerable extent. The increase in Inh.% values in presence of fixed concentration of iodide ions indicates that AZI extract forms an insoluble complex at lower AZI extract concentrations by undergoing a joint adsorption. But at higher concentrations of AZI extract, competitive adsorption is found between iodide ions and the formed complex leading to less Inh.%. The Inh.% decreased in presence of iodide ions with AZI extract than in presence of AZI extract alone at all studied iodide concentrations. The synergism parameter S {sub θ} is defined and calculated from surface coverage values. This parameter in the case of AZI extract is found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of iodide ions.

99m Technetium pyrophosphate myocardium scintigraphy. First results

International Nuclear Information System (INIS)

Toussaint, Paul.

1976-01-01

99m technetium pyrophosphate myocardium scintigraphy is a very recent examination technique. This work gives the results obtained on 61 patients. As a vector of the isotope, pyrophosphate has the advantage over polyphosphate of a fast bone uptake there it should be stressed that a 90 minute pause is necessary between the intraveinous injection of the isotope and the photographic recording so that the reading is not troubled by the labelled intracardiac blood pool image, an image quality criterion being the estimation of a good costal fixation which in fact appears sooner or later according to the subject. The role of pyrophosphate, chelator of calcium in fixation of the isotope on the myocardium, could be explained by the fast appearance of 'dense bodies', made up of calcium hydroxyapathice crystals, in the mitochondria of myocardium cells having undergone an irreversible necrotic process. The choice of 99 m technetium is based on its ease of use: 6 hour half-life, high-energy pure gamma emission at 140 keV. The fixed image studied under two incidences, front and left anterior oblique, is obtained from mobile images given by the scintillation camera used in connection with a data processing system. Several facts are underlined, explaining the disadvantages, advantages and indications of the method [fr

A neutral lipophilic technetium-99m complex for regional cerebral blood flow imaging

International Nuclear Information System (INIS)

Narra, R.K.; Nunn, A.D.; Kuczynski, B.L.; DiRocco, R.J.; Feld, T.; Silva, D.A.; Eckelman, W.C.

1990-01-01

Technetium-99m-DMG-2MP (Chloro[bis[2,3-butanedionedioxime(1-)-0][2,3- butanedionedioximato (2-)-N,N',N double-prime,N'double-prime,N double-prime double-prime,N'double-prime double-prime] (2-methylpropyl borato (2-))technetium]), also known as SQ 32097 is a member of a family of neutral lipophilic compounds generally known as boronic acid adducts of technetium dioxime complexes (BATOs). After i.v. administration, the concentration of [ 99m Tc]DMG-2MP in various regions of the brain appears to be proportional to blood flow. In rats, 1.1% ID was in the brain at 5 min postinjection when the blood contained less than 3% ID. Over 24 hr excretion was 59% in the feces and 23% in the urine. The activity in monkey brain at 5 min was 2.8% ID and it cleared with a t1/2 of 86 min. Autoradiographs of monkey brain sections showed excellent regional detail with a gray/white ratio of 3.6 at 10 min. The distribution of [ 99m Tc]DMG-2MP in the monkey brain corresponds to the known cytoarchitectural pattern of cerebral glucose metabolism. The properties of [ 99m Tc]DMG-2MP make it a potentially useful agent for cerebral perfusion imaging in man

Technetium-99m labeled radiodiagnostic agents and method of preparation

International Nuclear Information System (INIS)

1976-01-01

A method of preparing improved technetium-99m labelled radiodiagnostic agents by reducing sup(99m)Tc-pertechnetate with stannous tartrate is given. Human serum albumine (HSA) and 1-hydroxyethylidene-1,1-disodiumphosphonate (HEDSPA), which are useful in scintigraphic examinations of the lung and bone, were labelled in this way

The method of determination of micro quantities of labeled iodide in carrier free Na125 solution

International Nuclear Information System (INIS)

Kholbaev, A.Kh.; Shilin, E.A.

1996-01-01

The method of determination of microquantities of labelled iodide in Na 125 carrier-free solution was elaborated. This method permits to increase the sensitivity and radiation protection of the determination of labeled iodide. It includes oxidation of iodide by iodate in diluted sulphuric acid with molar concentration 0,03-0,04 mole/l. The extraction of I 2 is made by toluene. The coloured solution is made and optical density is measured at λ=640 nm at the 10 mm optical path .(A.A.D.)

Photochemical versus biological production of methyl iodide during Meteor 55

Science.gov (United States)

Richter, U.; Wallace, D.

2003-04-01

The flux of methyl iodide from sea to air represents the largest flux of iodine from the ocean to the atmosphere. Surface water concentrations and hence fluxes are particularly high in tropical regions. This flux may be responsible for the enrichment of iodine in the marine aerosol and may contribute to important processes in the marine boundary layer, including particle formation. Methyl iodide is commonly referred to as a biogenic gas, with both macroalgae and phytoplankton identified as important sources. On the other hand experimental and field data have shown the importance of photochemical production that is not necessarily associated directly with biological activity. During the Meteor cruise 55 along 11°N in the tropical Atlantic Ocean, a series of experiments were conducted to examine the biological vs. photochemical production of methyl iodide. A total of eight separate experiments were conducted. Production of CH3I in quartz glass flasks during 24 hour incubations (dark and natural sunlight) was measured under three experimental treatments: untreated seawater, filtered seawater (0.1 um pore size filter to exclude most phytoplankton and bacteria), and seawater that was poisoned with mercuric chloride. There were two clear findings from these experiments: (1) methyl iodide production was significantly higher in all the incubations that were exposed to the light than in the dark incubations; (2) there was no significant difference between CH3I production under the three experimental treatments. These results argue very strongly for the primary importance of photochemical production of CH3I as opposed to biogenic production at least for the tropical open ocean surface waters. Further experiments are required to investigate the reactants involved, their sources, the wavelength and depth dependence of production, etc. as well as (possibly related) sink processes.

Fast technetium Eigen-colloid determination: preparative CPC combined with suspension liquid scintillation

International Nuclear Information System (INIS)

Breynaert, E.; Maes, A.

2005-01-01

Full text of publication follows: Both medical and environmental studies concerned with the solubility and the complexation chemistry of technetium have encountered colloidal Tc(IV)-forms. Although the existence of the Tc colloids has been proven by various techniques [1-6], their determination still remains an issue. Recently a Column Precipitation Chromatography (CPC) technique was developed which enabled the quantitative determination of technetium Eigen-colloids. Based on this technique, a solid phase extraction (SPE)-like methodology was developed that can be used in combination with suspension liquid scintillation to provide a fast analysis of the Eigen-colloid content of a sample. The CPC technique is a thorough analysis methodology for the quantitative determination of the Eigen-colloid content of a sample containing reduced technetium species. This technique requires a relative long elution scheme and fractionation of the eluate. The fractionation also implies a relatively long counting time to determine the Eigen-colloid activity of a sample. Currently an SPE-like analysis methodology was developed which combines a good estimate of the Eigen-colloid content with fast analysis times. To construct a methodology providing both features a specialized extraction apparatus was constructed and a quantitative suspension liquid scintillation technique was developed. This combination enables the Eigen-colloid determination within a short experimental time (15 min) and a limited counting time (60 min). The authors acknowledge a grant from KULeuven University and financial support from the KULeuven Geconcerteerde Onderzoeksacties (GOA2000/007). We also kindly acknowledge NIRAS/ONDRAF for financial support from Contract CCHO 20004004862 [1] Grossmann, B. and R. Muenze, Relationship between complex formation by 99 Tc(IV) and the chemical structure of aliphatic carboxylic acid ligands. The International Journal of Applied Radiation and Isotopes, 1982. 33(3): p. 189

A model for additive transport in metal halide lamps containing mercury and dysprosium tri-iodide

NARCIS (Netherlands)

Beks, M.L.; Haverlag, M.; Mullen, van der J.J.A.M.

2008-01-01

The distribution of additives in a metal halide lamp is examined through numerical modelling. A model for a lamp containing sodium iodide additives has been modified to study a discharge containing dysprosium tri-iodide salts. To study the complex chemistry the method of Gibbs minimization is used

Detection of unstable angina by /sup 99m/technetium pyrophosphate myocardial scintigraphy

International Nuclear Information System (INIS)

Abdulla, A.M.; Canedo, M.I.; Cortez, B.C.; McGinnis, K.D.; Wilhelm, S.K.

1976-01-01

/sup 99m/Technetium stannous pyrophosphate has been shown to accumulate in acutely infarcted myocardium. To determine if the isotope is also taken up by severely ischemic, but not necrotic myocardium, we performed myocardial scintigraphic studies in 17 patients with chest pains. Seven of the patients satisfied conventional clinical, electrocardiographic, and laboratory criteria for the diagnosis of unstable angina and showed no electrocardiographic or enzymatic evidence of myocardial necrosis. Five of these seven patients with unstable angina demonstrated abnormal localized patterns, and one showed a borderline picture. Myocardial scintiscans were normal in all of a control group of ten patients with stable angina. Thus, scanning with /sup 99m/technetium stannous pyrophosphate is shown to be of value in the objective demonstration of myocardial abnormality in unstable angina

Clinical usefulness of scintigraphy with sup 99m Technetium phosphates in rhabdomyolysis

Energy Technology Data Exchange (ETDEWEB)

Aizawa, Nobuyuki; Hara, Yoshikuni (Shonan Kamakura Hospital, Kanagawa (Japan)); Suzuki, Yutaka; Akashi, Tsunehiro; Kamei, Tetsumasa; Uchiyama, Fujio; Mitsui, Tamito; Yamazaki, Yuki

1990-08-01

We performed bone scans with {sup 99m}Technetium phosphates in 15 cases of clinically suspected rhabdomyolysis admitted to Chigasaki Tokushukai Hospital. Whole body scans were performed within 5 days from the onset of illness or admission. Accumulation of the radioactivity in the skeletal muscle was revealed in 13 of the 15 cases and the involved muscle groups were visualized vividly. Etiologies of rhabdomyolysis were diverse, ranging from malignant syndrome to sepsis. Myocardial concentration was absent in all of the cases. Renal concentration of the isotope was seen in cases where the degree of rhabdomyolysis was higher and renal impairment was present. We conclude that {sup 99m}Technetium phosphate bone scan is useful in clinically suspected rhabdomyolysis as a diagnostic test and as a test to localize and quantitate the muscular involvement. (author).

Interaction of simple indium iodides with silver- and aluminium iodides

International Nuclear Information System (INIS)

Denisov, Yu.N.; Halova, N.S.; Fedorov, P.I.

1976-01-01

Fusibility diagrams of the systems InI-AlI 3 , InI-AgI, InI 2 -AgI, and InI 2 -AlI 3 have been studied. In the system InI-AlI 3 a compound InAlI 4 has been detected having a melting point 194 deg C and two lamination regions. In the system InI-AgI two compounds In 2 AgI 3 and InAgI 2 are formed which melt incongruently at 272 deg and 220 deg C, respectively. The formation of the compounds has been confirmed by X-ray phase analysis. Specific electroconductivity of a number of alloys of the system InI-AlI 3 has been studied. The systems of eutectic type formed by diiodide of indium with iodides of silver and aluminium have been studied by thermal and X-ray analysis and by measuring electroconductivity

Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

Directory of Open Access Journals (Sweden)

Viroj Wiwanitkit

2011-01-01

Full Text Available The recent nuclear disaster at Japan has raised global concerns about effects of radioactive leakage in the environment, associated hazards, and how they can be prevented. In this article, we have tried to explain about the guidelines laid down by World Health Organization for a potassium iodide prophylaxis following a nuclear disaster, and its mechanism of action in preventing thyroid cancer. Data was collected mainly from the studies carried out during the Chernobyl disaster of Russia in 1986 and the hazardous effects especially on the thyroid gland were studied. It was seen that radioactive iodine leakage from the nuclear plants mainly affected the thyroid gland, and especially children were at a higher risk at developing the cancers. Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster. However, one has to be cautious while giving it, as using it without indication has its own risks.

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray...

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray spectrometers. Two...

Advances in technetium chemistry towards 99mTc receptor imaging agents

International Nuclear Information System (INIS)

Johannsen, B.; Spies, H.

1997-01-01

The development of the chemistry of technetium and its non-radioactive surrogate rhenium has been prompted by the trends and needs of nuclear medicine, which predominantly uses 99m Tc radiopharmaceuticals for a broad range of diagnostics. Technetium-99m is the ideal radioisotope for tomographic single-photon emission tomography (SPECT) imaging due to its nuclear properties (6.2 h, E γ 140 keV) and ready availability through generator systems. Transition metals offer many opportunities for designing molecules by modifying the environment around the core, allowing certain biological properties to be imposed upon the molecule. Whereas research in the past was mainly concerned with biological properties that allow relatively unspecific functional imaging, as in brain or myocardium perfusion studies, nuclear medicine is now requiring more and more biochemical information on low capacity, high specificity targets. Many research groups have become involved in the search for new technetium-based compounds, called the third generation of 99m Tc radiopharmaceuticals, that employ the principles of modern pharmacology to achieve biochemical specificity. There has been considerable interest in imaging CNS and other receptors with 99m Tc receptor-binding ligands. Such a 99m Tc CNS receptor-imaging agent is currently not yet in use because of the significant hurdles to be overcome in attaining this ambitious goal. However, some Tc and Re complexes of remarkable affinity in vitro, and the first high-affinity 99m Tc probes able to label the dopamine transporter in the brain by SPECT imaging prove the feasibility of this approach. (Author)

Technetium-99m-Sestamibi in the diagnosis of acute chest pain

International Nuclear Information System (INIS)

Gilleece, T.; Salehi, N.; Better, N.

1998-01-01

Full text: A 45-year-old male was admitted to coronary care with a two-day history of recurrent chest pain. Despite maximal medical therapy, pain persisted. Examination and ECG with pain, were normal, suspicion of ischaemia was moderately high but coronary angiography was not immediately available. Technetium-99m-Sestamibi was prepared at the start of the day according to the standard preparation protocol (Du Pont). Coronary Care informed the Nuclear Medicine Department immediately the patient experienced a further episode of chest pain. Technetium-99m-Sestamibi was administered in coronary care, 4.30 minutes after being advised of the onset of further chest pain. Images were acquired 60 minute post-injection; 15 minutes after the patient had been given 200 mL of milk. A triple-headed gamma camera was used to acquire SPECT images over a 1200 arc, 30 frames of 30 seconds using a 64 x 64 matrix. The patient was laying prone with arms raised out of the field of view. Images showed a normal distribution of technetium-99m -Sestamibi throughout the myocardium. Due to ongoing clinical suspicion by the treating physician, coronary angiography was subsequently performed. This showed normal coronary arteries. Medical therapy was ceased and the patient discharged the next day. We concluded that the chest pain at the time of injection was not ischaemic. Previous trials had shown a 95% sensitivity for this method of diagnosing ischaemia. This method permits a novel and simple technique for diagnosing myocardial ischaemia and obviating the need for cardiac catheterization in this group of patients

Grotthuss Transport of Iodide in EMIM/I3 Ionic Crystal.

Science.gov (United States)

McDaniel, Jesse G; Yethiraj, Arun

2018-01-11

Highly ionic environments can mediate unusual chemical reactions that would otherwise be considered impossible based on chemical intuition. For example, the formation of a chemical bond between two iodide anions to form a divalent polyiodide anion is seemingly prohibited due to Coulombic repulsion. Using ab initio molecular dynamics simulations, we show that in the 1-ethyl-3-methylimidazolium (EMIM)/I 3 ionic crystal, the reactive formation of divalent and even trivalent polyiodide anions occurs with extremely small energetic barriers, due to the electrostatic field of the ionic lattice. A practical consequence of this anomalous reactivity is that iodide anions are efficiently transported within the crystal through a "Grotthuss-exchange" mechanism involving bond-breaking and forming events. We characterize two distinct transport pathways, involving both I 4 2- and I 7 3- intermediates, with fast transport of iodide resulting from the release of an I - anion on the opposite side of the intermediate species from the initial bond formation. The ordered cation arrangement in the crystal provides the necessary electrostatic screening for close approach of anions, suggesting a new counterintuitive approach to obtain high ionic conductivity. This new design principle could be used to develop better solid-state electrolytes for batteries, fuel cells, and supercapacitors.

Sorption of microamount of colloidal silver iodide on hydrated iron(III) oxide

International Nuclear Information System (INIS)

Kepak, F.; Nova, J.

1975-01-01

Sorption of a microamount of colloidal silver iodide labelled with 131 I on hydrated iron/III/ oxide suspension was studied. The sorption dependence upon pH, sorbent amount, and inert electrolyte concentration has revealed that sorption of silver iodide reaches no more than 63%. The sorption lasted one hour during which the maximum value was reached. Desorption time was one hour, as well. Except for measuring the sorption dependence on pH, the sorption pH was 7.0, temperature 24+-2 0 C. (F.G.)

Determination of technetium by total reflection x-ray fluorescence

International Nuclear Information System (INIS)

Bermudez, J.I.; Greaves, E.D.; Nemeth, P.

2000-01-01

We describe a technique using total reflection x-ray fluorescence (TXRF) for determination of Technetium produced by elution of chromatography generators with physiological saline solutions. The analysis with the 18.41 keV K α line of Technetium was accomplished with monochromatized K α radiation from a silver anode x-ray tube operated at 45 keV and 20 mA. This radiation at 22.104 keV is efficiently coupled to the 21.054 keV absorption edge of Tc. It is also of advantage in the direct analysis of organic and saline properties of the Tc-bearing samples. Quantification was accomplished by internal standard addition of Ga and using an interpolated value of the sensitivity for Tc between Molybdenum and Rhenium. Data processing was carried out with the QXAS-AXIL software package. System sensitivity was found adequate for direct Tc determination of eluted saline solutions. The interest and advantages of the use of the technique as an auxiliary in the synthesis and characterization of Tc-labeled radiopharmaceuticals used for diagnosis in nuclear medicine are discussed. Detection limits in the matrices analyzed are reported. (author)

Determination of degradation conditions of exchange resins containing technetium

International Nuclear Information System (INIS)

Rivera S, A.; Monroy G, F.; Quintero P, E.

2014-10-01

The quantification of Tc-99 in spent exchange resins, coming from nuclear power plants, is indispensable to define their administration. The Tc-99 is a pure beta emitter of 210000 years of half-life, volatile and of a high mobility in water and soil. For this reason, the objective of this work is to establish a digestion method of ionic exchange resins containing technetium that retains more than 95% of this radioisotope. Mineralization tests were carried out of a resin Amberlite IRN-150 by means of an oxidation heat, in acid medium, varying the resin mass, the medium volume, the media type, the temperature and the digestion time. The digested samples were analyzed by gas chromatography to estimate the grade of their degradation. The 99m Tc was used as tracer to determine the technetium percentage recovered after mineralizing the resin. The digestion process depends on the temperature and the resin mass. At higher temperature better mineralization of samples and to greater resin mass to a constant temperature, less degradation of the resin. The spectra beta of the 99m Tc and 99 Tc are presented. (Author)

Potassium iodide stockpiling

International Nuclear Information System (INIS)

Krimm, R.W.

1983-01-01

After examination by the Federal Emergency Management Agency (FEMA) and other federal agencies of federal policy on the use and distribution of potassium iodide (KI) as a thyroid-blocking agent for use in off-site preparedness around commercial nuclear powerplants, FEMA believes the present shelf life of KI is too short, that the minimum ordering quantities are an obstacle to efficient procurement, and that the packaging format offered by the drug industry does not meet the wishes of state and local government officials. FEMA has asked assistance from the Food and Drug Administration in making it possible for those states wishing to satisfy appropriate requirements to do so at the minimum cost to the public. Given an appropriate packaging and drug form, there appears to be no reason for the federal government to have further involvement in the stockpiling of KI

Technetium compounds

International Nuclear Information System (INIS)

Murphy, C.A. de; Ferro F, G.

2003-01-01

The first radiopharmaceuticals of 99m Tc, also call of 'first generation' as colloids, aggregates and simple complexes were developed with relative easiness without it was necessary a wide understanding of its chemical structure. In the radiopharmaceuticals of 'second generation' were included those derived of the HIDA for hepatobiliary images, MAG3 and EC for images of tubular renal de purification, HMPAO and ECD for images of cerebral perfusion and MIBI and tetrofosmin for images of heart perfusion, that which implies a bigger demand in terms of the chemical knowledge. At the moment, we can affirm that the future of the radiopharmaceuticals of 99m Tc is based on the use of small and relevant biomolecules with high biological activity that allow the visualization in vivo of specific receiving sites and/or its expression in diverse pathologies. It is for it that with the 'third generation' is necessary a wide one knowledge of the chemistry of the technetium that allows the design and characterization of highly specific bio complexes. In this book, although focused mainly to the chemistry of the Tc, a brief revision is also presented on the main biologically active molecules that, coordinated the 99m Tc, present a high recognition In vivo for specific receivers. (Author)

Detection of apoptotic cells using propidium iodide staining

NARCIS (Netherlands)

Newbold, Andrea; Martin, Ben P.; Cullinane, Carleen; Bots, Michael

2014-01-01

Flow cytometry assays are often used to detect apoptotic cells in in vitro cultures. Depending on the experimental model, these assays can also be useful in evaluating apoptosis in vivo. In this protocol, we describe a propidium iodide (PI) flow cytometry assay to evaluate B-cell lymphomas that have

Technetium-99m-human fibrinogen

International Nuclear Information System (INIS)

Wong, D.W.; Mishkin, F.S.

1975-01-01

Exogenous fibrinogen has been successfully labeled with /sup 99m/Tc using a modified electrolytic method. The exact labeling mechanism has not been determined. Experimental data suggest that the labeling process of /99m/Tc-fibrinogen is quite similar to that of /sup 99m/Tc-human serum albumin as reported earlier by Benjamin. Technetium-99m-fibrinogen is stable in human plasma or in 1 percent buffered human serum albumin. A binding efficiency of 76 percent has been achieved with approximately 25 percent clottable protein. The entire labeling procedure requires less than 1 hr of preparation time. This short labeling time in a closed system may allow development of a practical method for labeling autologous fibrinogen, thus eliminating the risk of hepatitis transmission. (U.S.)

Effects of Potassium Iodide on Low Avid Immunological Reactions ...

African Journals Online (AJOL)

In identical test conditions keeping appropriate control, the following ... Abstract. Background: Selective in‑vivo anti‑fungal action of potassium iodide (KI) is an enigma, but .... mechanism of action of the drug against selective infections. In fact, if ...

Alpha-lipoic acid induces sodium iodide symporter expression in TPC-1 thyroid cancer cell line

International Nuclear Information System (INIS)

Choi, Hyun-Jeung; Kim, Tae Yong; Ruiz-Llorente, Sergio; Jeon, Min Ji; Han, Ji Min; Kim, Won Gu; Shong, Young Kee; Kim, Won Bae

2012-01-01

Introduction: Patients with metastatic thyroid cancers that do not uptake iodine need effective therapeutic option. Differentiation-inducing agents have been tried to restore functional expression of sodium iodide symporter (NIS) without success. Our objective was to assess the effect of alpha-lipoic acid (ALA), known as potential antioxidant, on expression of sodium iodide symporter in thyroid cancer cells. Methods: Human thyroid cancer-derived cell lines, TPC-1, were treated with ALA, and changes in NIS mRNA and protein expression were measured. ALA's effect on NIS gene promoter was evaluated, and functional NIS expression was assessed by iodide uptake assay. Results: Treatment with ALA increased NIS mRNA expression up to ten folds of control dose-dependently after 24 h of exposure. ALA increased NIS promoter activity, and increased iodide uptake by 1.6 fold. ALA induced expression of NIS protein, but had no significant effect on the plasma membrane trafficking. ALA increased phosphorylation of CREB and nuclear translocation of pCREB, and co-treatment of ALA and trichostatin A increased iodide uptake by three folds in TPC-1 cells. Conclusions: ALA is a potential agent to increase NIS transcription in TPC-1. It could be used as an adjunctive agent to increase efficacy of radioiodine therapy if combined with a strategy to increase NIS protein trafficking to cell membrane.

Removal of technetium from alkaline nuclear-waste media by a solvent-extraction process using crown ethers

International Nuclear Information System (INIS)

Bonnesen, P.V.; Presley, D.J.; Haverlock, T.J.; Moyer, B.A.

1995-01-01

Crown ethers dissolved in suitably modified aliphatic kerosene diluents can be employed to extract technetium as pertechnetate anion (TcO 4 - ) with good extraction ratios from realistic simulants of radioactive alkaline nitrate waste. The modifiers utilized are non-halogenated and non-volatile, and the technetium can be removed from the solvent by stripping using water. The crown ethers bis-4,4'(5')[(tert-butyl)cyclohexano]-18-crown-6 (di-t-BuCH18C6) and dicyclohexano-18-crown-6 (DCH18C6) provide stronger TcO 4 - extraction than dicyclohexano-21-crown-7 and 4-tert-butylcyclohexano 15-crown-5. Whereas DCH18C6 provides somewhat higher TcO 4 - extraction ratios than the more lipophilic di-t-BuCH18C6 derivative, the latter was selected for further study owing to its lower distribution to the aqueous phase. Particularly good extraction and stripping results were obtained with di-t-BuCH 18C6 at 0.02 M in a 2:1 vol/vol blend of tributyl phosphate and Isopar reg-sign M. Using this solvent, 98.9% of the technetium contained (at 6 x 10 -5 M) in a Double-Shell Slurry Feed (DSSF) Hanford tank waste simulant was removed following two cross-current extraction contacts. Two cross-current stripping contacts with deionized water afforded removal of 99.1% of the technetium from the organic solvent

Small-molecule inhibitors of sodium iodide sym-porter function

International Nuclear Information System (INIS)

Lecat-Guillet, N.; Merer, G.; Lopez, R.; Rousseau, B.; Ambroise, Y.; Pourcher, T.

2008-01-01

The Na + /l - sym-porter (NIS) mediates iodide uptake into thyroid follicular cells. Although NIS has been cloned and thoroughly studied at the molecular level, the biochemical processes involved in post-translational regulation of NIS are still unknown. The purpose of this study was to identify and characterize inhibitors of NIS function. These small organic molecules represent a starting point in the identification of pharmacological tools for the characterization of NIS trafficking and activation mechanisms. screening of a collection of 17020 drug-like compounds revealed new chemical inhibitors with potencies down to 40 nM. Fluorescence measurement of membrane potential indicates that these inhibitors do not act by disrupting the sodium gradient. They allow immediate and total iodide discharge from preloaded cells in accord with a specific modification of NIS activity, probably through distinct mechanisms. (authors)

Small-molecule inhibitors of sodium iodide sym-porter function

Energy Technology Data Exchange (ETDEWEB)

Lecat-Guillet, N.; Merer, G.; Lopez, R.; Rousseau, B.; Ambroise, Y. [CEA, DSV, Dept Bioorgan Chem et Isotop Labelling, Inst Biol et Biotechnol iBiTecS, F-91191 Gif Sur Yvette (France); Pourcher, T. [Univ Nice Sophia Antipolis, Dept Biochem et Nucl Toxicol, F-06107 Nice (France)

2008-07-01

The Na{sup +}/l{sup -} sym-porter (NIS) mediates iodide uptake into thyroid follicular cells. Although NIS has been cloned and thoroughly studied at the molecular level, the biochemical processes involved in post-translational regulation of NIS are still unknown. The purpose of this study was to identify and characterize inhibitors of NIS function. These small organic molecules represent a starting point in the identification of pharmacological tools for the characterization of NIS trafficking and activation mechanisms. screening of a collection of 17020 drug-like compounds revealed new chemical inhibitors with potencies down to 40 nM. Fluorescence measurement of membrane potential indicates that these inhibitors do not act by disrupting the sodium gradient. They allow immediate and total iodide discharge from preloaded cells in accord with a specific modification of NIS activity, probably through distinct mechanisms. (authors)

Extraosseous uptake of 99sup(m)technetium methylene diphosphonate

International Nuclear Information System (INIS)

Sty, J.R.; Kun, L.; Casper, J.; Babbitt, D.P.

1980-01-01

A child with a ganglioneuroblastoma and tumor uptake of 99 sup(m)technetium methylene diphosphate ( 99 sup(m)Tc-MDP) is presented. After surgical removal of an encapsulated tumor and radiation therapy, an interval bone scan demonstrated the same presurgical abnormality. Awareness of abnormal uptake of 99 sup(m)Tc-MDP in irradiated renal tissue prevents interpreting radiation nephritis as recurrent tumor. (orig.) [de

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

Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

International Nuclear Information System (INIS)

Friedrich, V.; Lux, I.

1991-01-01

A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties - Final Report

International Nuclear Information System (INIS)

Mallouk, Thomas E.; Ponder, S.M.

2000-01-01

This research is a three year project involving close collaboration between chemists at Pennsylvania State University and materials scientists at Pacific Northwest National Laboratory (PNNL). The goal of the project is the development and characterization of supported reducing agents, and solid waste forms derived from them, which will be effective in remediation of aqueous wastes. The work follows the recent discovery that zero-valent metals, such as iron, are effective decontaminants for waste streams containing chlorinated hydrocarbons. Preliminary data, obtained at Penn State and elsewhere, have shown that the same strategy will be effective in reducing soluble compounds containing toxic metals (technetium, lead, mercury, and chromium) to insoluble forms. The Penn State group has prepared a new class of powerful reducing agents, called Ferragels, which consist of finely divided zero-valent metals on high surface area supports. Because the rate of the surface oxidation-reduction reaction depends on available surface area, Ferragels are more effective in every case tested to date than unsupported metals. The project will further develop and investigate the application of these composite materials to problems relevant to the DOE-EM mission, namely the detoxification of waste streams containing technetium, carbon tetrachloride, and toxic metal ions. The Penn State group will work closely with the PNNL group to prepare materials that are compatible with the highly corrosive liquid fraction of Hanford site tank waste, to conduct tests with waste simulants containing technetium, and to formulate and characterize vitrified waste forms derived from these materials

Extraction method for the determination of inorganic iodides in Rose Bengal labelled with 131I

International Nuclear Information System (INIS)

Lengyel, J.; Krtil, J.; Vecernik, J.

1982-01-01

An extraction method for the determination of inorganic iodides in Rose Bengal preparations labelled with 131 I is described. The method is based on the quantitative extraction of Rose Bengal into chloroform from acidic medium while the inorganic iodides remain in the aqueous phase. The method is simple, rapid, and reproducible. (author)

Multi-organ technetium complexes production and use thereof

International Nuclear Information System (INIS)

Koehler, G.A.; Pestel, G.M.

1976-01-01

Chemical complexes, useful as radiopharmaceuticals, are formed by reacting technetium-99m with substituted or unsubstituted alkyl monophosphonic acids and certain ester derivatives thereof. The complexes are formed by reducing pertechnetate ion chemically or electrolytically in the presence of the phosphonic acid. By chemical modification of the phosphonic acid complexing agent, it is possible to ''tailor'' complexes for kidney, liver or bone imaging. The complexes are normally used in a physiologically acceptable aqueous medium. 20 Claims, No Drawings

Uptake of Iodide From Water in Atlantic Halibut Larvae (Hippoglossus Hippoglossus L.)

DEFF Research Database (Denmark)

Moren, Mari; Sloth, Jens Jørgen; Hamre, Kristin

2008-01-01

The natural diet of marine fish larvae, copepods, contain 60-350 mg I kg(-1), while live feed used in commercial hatcheries have iodine concentrations in the range of 1 mg kg(-1). Seawater is also considered to be an important source of iodine for marine fish. The question asked in this study is ......M. The uptake was partly blocked by perchlorate (ClO3-) which is a known inhibitor of the sodium iodide symporter. This indicates that the Atlantic halibut larvae accumulate iodide through both specific and non-specific uptake pathways....

Method for removing radioactive iodine and radioactive organic iodides from effluent gases

International Nuclear Information System (INIS)

1975-01-01

A method and composition for removing radioactive and organic iodides from an 131 I-containing off-gas stream is provided. The composition for removal by adsorption is a ceramic material with a surface area of from about 5 m 2 /g to about 250 m 2 /g impregnated with a metallic salt. The method for removing the iodine or iodide is accomplished by passing the off-gas stream over the ceramic material impregnated with the metallic salt. It finds special application in air filters for nuclear power plants

The impact of technetium-99m-radiopharmaceuticals' design on their biological behavior

International Nuclear Information System (INIS)

Jankovic, D.Lj.; Djokic, D.Dj. . E-mail address of corresponding author: drinaj@vin.bg.ac.yu; Jankovic, D.)

2005-01-01

The coordination has a great and not always predictable impact on the in-vivo behaviour of the small molecule into which the technetium-bearing chelate units is integrated. The different valence state of technetium in the complexes with some ligands changes the properties of these complexes, such as physico-chemical parameters and biological behaviour. The change of their biological behaviour has a great impact on quality of imaging study and on radiation dose to the patient. The results of the labelling of DPD and EHIDA with 99mTc(I) and their biological behaviour, in comparison with the same one for 99mTc(III)-DPD and 99mTc(III)-EHIDA complexes, confirmed that different oxidation state of 99mTc make possible forming variety of complexes with quite a different and unexpected biological behaviour. (author)

Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

Science.gov (United States)

Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

2013-03-01

Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

PREDICTION OF RELAPSE FROM HYPERTHYROIDISM FOLLOWING ANTITHYROID MEDICATION WITHDRAWAL USING TECHNETIUM THYROID UPTAKE SCANNING.

Science.gov (United States)

Nakhjavani, Manouchehr; Abdollahi, Soraya; Farzanefar, Saeed; Abousaidi, Mohammadtagi; Esteghamati, Alireza; Naseri, Maryam; Eftekhari, Mohamad; Abbasi, Mehrshad

2017-04-02

Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement. Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic. Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3). TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal. ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

Confinement Effects in Low-Dimensional Lead Iodide Perovskite Hybrids

NARCIS (Netherlands)

Kamminga, Machteld E.; Fang, Honghua; Filip, Marina R.; Giustino, Feliciano; Baas, Jacobus; Blake, Graeme R.; Loi, Maria Antonietta; Palstra, Thomas T. M.

2016-01-01

We use a layered solution crystal growth technique to synthesize high-quality single crystals of phenylalkylammonium lead iodide organic/inorganic hybrid compounds. Single-crystal X-ray diffraction reveals low-dimensional structures consisting of inorganic sheets separated by bilayers of the organic

Fast iodide-SAD phasing for high-throughput membrane protein structure determination.

Science.gov (United States)

Melnikov, Igor; Polovinkin, Vitaly; Kovalev, Kirill; Gushchin, Ivan; Shevtsov, Mikhail; Shevchenko, Vitaly; Mishin, Alexey; Alekseev, Alexey; Rodriguez-Valera, Francisco; Borshchevskiy, Valentin; Cherezov, Vadim; Leonard, Gordon A; Gordeliy, Valentin; Popov, Alexander

2017-05-01

We describe a fast, easy, and potentially universal method for the de novo solution of the crystal structures of membrane proteins via iodide-single-wavelength anomalous diffraction (I-SAD). The potential universality of the method is based on a common feature of membrane proteins-the availability at the hydrophobic-hydrophilic interface of positively charged amino acid residues with which iodide strongly interacts. We demonstrate the solution using I-SAD of four crystal structures representing different classes of membrane proteins, including a human G protein-coupled receptor (GPCR), and we show that I-SAD can be applied using data collection strategies based on either standard or serial x-ray crystallography techniques.

Validation of measurements of Fourier phase and amplitude analysis of technetium99 gated cardiac scans using artificial hearts

International Nuclear Information System (INIS)

Yiannikas, J.; Takatani, S.; MacIntyre, W.J.; Underwood, D.A.; Cook, S.A.; Go, R.T.; Napoli, C.; Nose, Y.

1982-01-01

The use of artificial hearts, developed for total heart replacement programs, allows assessment of the accuracy of measuring the first Fourier component phase and amplitude when applied to gated cardiac technetium 99 scans. In the extreme example of asynchrony of ventricular contraction in coronary artery disease that of ventricular aneurysms, the first Fourier component measurements of amplitude were highly correlated to volume increases suggesting that the calculated amplitude accurately reflects volume changes. The calculated asynchrony using Fourier analysis of the gated technetium 99 studies of two artificial hearts was highly accurate when compared to the predetermined calculation of phase angle difference and hence degree of asynchrony. The studies suggest that measurement of phase and amplitude using the first Fourier component of time-activity waves of gated cardiac technetium 99 studies accurately measure degree of asynchrony and volume changes respectively

Precipitation process for the removal of technetium values from nuclear waste solutions

Science.gov (United States)

Walker, D.D.; Ebra, M.A.

1985-11-21

High efficiency removal of techetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

Simulation of technetium extraction behavior in UO2 (NO3)2-TcO4--HNO3-H2O/TBP-kerosene system

International Nuclear Information System (INIS)

Zhang Chunlong; He Hui; Chen Yanxin; Tang Hongbin

2012-01-01

By comparing and analyzing lots of reported data of technetium with the computing results, a modification function P(c 0 (U), t) was introduced to the existing distribution coefficient model of technetium, and a new mathematical model for simulating technetium extraction behavior in the system of UO 2 (NO 3 ) 2 -TcO 4 -HNO 3 -H 2 O/TBP- kerosene was established, as well as a computer program. The reliability of the program was verified by 179 sets of distribution coefficient data, and the results were found to agree well with experimental data. By comparing the reported data of technetium with the computing results, an evaluation was made to test the performance of the revised model. It turned out that the calculation results of the new model were more reliable than that of the one reported previously. The revised model and program can be the foundation to simulating technetium extraction behavior in the system of UO 2 (NO 3 ) 2 - TcO 4 - -HNO 3 -H 2 O/TBP-kerosene with the temperature scope from 10 to 60℃, U concentration from 0 to 280 g/L, and nitric acid concentration from 0.1 to 5 mol/L. (authors)

Synthesis, libelling and bio-distribution of cerebral radiopharmaceuticals with Technetium 99

International Nuclear Information System (INIS)

Malek Saied, Nadia

2013-01-01

The prevalence of brain pathologies especially neurodegenerative diseases still increasing due to longer life expectancy and the age pyramid evolution that shows an increase in the proportion of the old persons. So, we count currently more than 30 million persons affected by a neuro-degenerative disease. It is estimated that this number will reach 100 million at 2050. Generally, these diseases are not fatal, but the intellectual handicap and/or the progressive physical deterioration which causes some of them (Alzheimer, Parkinson), may lead to the death. Despite the screening efforts, it remains difficult to establish an early and differential diagnosis. It is proposed that research provides new solutions for diagnostic to reduce the risk of mortality associated with these diseases and improve patient comfort. The first part of this presentation is dedicated to some definitions of the radiopharmaceuticals, the chemistry of technetium and rhenium and the strategies of labeling with Technetium. We propose first to give an overview concerning the target vectors and criteria for crossing of the hemato-encephalic barrier. In the second part we will present our results concerning the synthesis and the physico-chemical characterization of some ferrocenic ligands, radio-complex of the technetium-99 and their "rhenisted" analogues. We will expose some bio-distributions as well as the biochemical studies of certain cytectrenic molecules which showed a very interesting affinity for 5HT1A serotonergic receptors such as Tc-MP associated to the molecule of piperazine (2 - methoxyphenyl) as a vector of choice. This molecule allows an exceptional kinetic of extraction around (2.47 pou cent DI / g) in 5min pi. (Author)

Methyl iodide tests on used adsorbents

International Nuclear Information System (INIS)

Kovach, J.L.

1993-01-01

This paper discusses the history of events leading to the current problems in radioiodine test conditions. These radioiodine tests are performed in the adsorbent media from both safety and non-safety related Nuclear Air Treatment Systems (NATS). The main problem addressed is that currently there are still numerous plant technical specifications for NATS which reference outdated test protocols for the surveillance testing of the radioactive methyl iodide performance of the adsorbents. Recommendations for correcting the test condition problems are presented. 7 refs

Adsorption behavior of calcined layered double hydroxides towards removal of iodide contaminants

International Nuclear Information System (INIS)

Lu Liang; He Jing; Wei Min; Evans, D.G.; Duan Xue

2005-01-01

Layered double hydroxides (LDHs), are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions giving positively-charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. The general formula is EM 2+ 1-x M 3+ x (OH) 2 ] x+ (A n- ) x/n · mH 2 O, where M 2+ and M 3+ are metal cations for example Mg 2+ and Al 3+ , that occupy octahedral sites in the hydroxide layers, A n- is an exchangeable anion, and x is the ratio M 3+ /(M 2+ + M 3+ ) and the layer charge will depend on the M 2+ /M 3+ ratio. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDH is based on a very interesting property of these materials, the so-called memory effect: Calcination of LDHs produces intermediate non-stoichiometric oxides (CLDH) which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Radioactive iodide is widely used in biological experiments, medical treatments and in diagnosis. During fission of uranium several iodine species are produced. All the short lived isotopes of iodine, including 1311 (half life 8.04 days), decay and only 127 I (stable) and 129 I (half life 1.59 x 10 7 years) remain as a problem. 129 I is especially considered as one of the key radionuclides that dominate the long-term radiation in underground radioactive waste stores. Iodine is one of the nuclides causing most concern among radioactive anions. Different adsorbents such as zeolites, silica gel, anion exchange paper membrane, activated carbon and activated carbon fibers, have been investigated as potential materials for elimination of iodide from liquid wastes. In this work

Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process.

Science.gov (United States)

Sun, Zhuyu; Zhang, Chaojie; Chen, Pei; Zhou, Qi; Hoffmann, Michael R

2017-12-15

Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (e aq - ) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I - and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I - and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of e aq - due to the reduction of I 2 , HOI, IO 3 - and I 3 - back to I - ; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I - and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces e aq - . The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

The sodium iodide symporter: its implications for imaging and therapy

International Nuclear Information System (INIS)

Spitzweg, C.

2007-01-01

The sodium iodide symporter (NIS) is an intrinsic plasma membrane glycoprotein that mediates the active transport of iodide in the thyroid gland and a number of extrathyroidal tissues, in particular lactating mammary gland. In addition to its key function in thyroid physiology, NIS-mediated iodide accumulation allows diagnostic thyroid scintigraphy as well as therapeutic radioiodine application in benign and malignant thyroid disease. NIS therefore represents one of the oldest targets for molecular imaging and therapy. Based on the effective administration of radioiodine that has been used for over 60 years in the management of follicular cell-derived thyroid cancer, cloning and characterization of the NIS gene has paved the way for the development of a novel cytoreductive gene therapy strategy based on targeted NIS expression in thyroidal and nonthyroidal cancer cells followed by therapeutic application of 131 I or alternative radionuclides, including 188 Re and 211 At. In addition, the possibility of direct and non-invasive imaging of functional NIS expression by 123 I- and 99m Tc-scintigraphy or 124 I-PET-imaging allows the application of NIS as a novel reporter gene. In conclusion, the dual role of NIS as diagnostic and therapeutic gene and the detection of extra-thyroidal endogenous NIS expression in breast cancer open promising perspectives in nuclear medicine and molecular oncology for diagnostic and therapeutic application of NIS outside the thyroid gland. (orig.)

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

Preparation and characterisation of a sorbent suitable for technetium separation from environmental matrices

International Nuclear Information System (INIS)

Bartosova, A.; Rajec, P.; Reich, M.

2003-01-01

A sorbent based on Aliquat 336 anchored on hydrophobised silica gel support as an ion exchanger was prepared. Prepared sorbent was suitable for separation of technetium-99 from environmental matrices. The sorbent properties, sorption characteristic and distribution coefficient of 99 mTcO 4 - in various medium was studied. The chemical yield of Tc during separation process was determined using 99m Tc tracer and gamma measurement. Typical sorption recoveries of Tc for this sorbent from 0.1 M HNO 3 were more than 98 %. Typical desorption recoveries using 8 M HNO 3 were in the range 92 - 96 %. The commercial TEVA Spec resin from Eichrom Industries for comparison purpose was used as well. It was found that the prepared sorbent is suitable for separation of technetium from environmental matrices. (authors)

Review of technetium chemistry research conducted at the University of Nevada Las Vegas

International Nuclear Information System (INIS)

Poineau, F.; Weck, P.F.; Forster, P.; Hartmann, T.; Mausolf, E.; Silva, G.W.C.; Czerwinski, K.R.; Rodriguez, E.E.; Sattelberger, A.P.; Jarvinen, G.D.; Cheetham, A.K.

2009-01-01

The chemistry of technetium is being explored at the University of Nevada Las Vegas. Our goal is to investigate both the applied and fundamental aspects of technetium chemistry, with a special emphasis on synthesis, separations, and materials science. The synthetic chemistry focuses on metal-metal multiple bonding, oxides and halides. Synthesis and characterizations of (n-Bu 4 N) 2 Tc 2 X 8 , Tc 2 (O 2 CCH 3 ) 4 X 2 (X = Cl, Br), TcO 2 , Bi 2 Tc 2 O 7 , Bi 3 TcO 8 , TcBr 3 and TcBr 4 have been performed. The applied chemistry is related to the behavior of Tc in the UREX process. Separation of U/Tc has been conducted using anion exchange resin and metallic Tc waste form synthesized and characterized. (author)

High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide.

Science.gov (United States)

Dastidar, Subham; Egger, David A; Tan, Liang Z; Cromer, Samuel B; Dillon, Andrew D; Liu, Shi; Kronik, Leeor; Rappe, Andrew M; Fafarman, Aaron T

2016-06-08

Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.

Performance of iodide vapour absorption in the venturi scrubber working in self-priming mode

International Nuclear Information System (INIS)

Zhou, Yanmin; Sun, Zhongning; Gu, Haifeng; Miao, Zhuang

2016-01-01

Highlights: • The absorption performance for iodide vapour was studied under different conditions. • A mathematical model was developed to describe the iodide absorption process. • The venturi scrubber can ensure absorption efficiiency and reduce pressure loss. - Abstract: The self-priming venturi scrubber is the key component of filtered containment venting systems for the removal of radioactive products during severe accidents in nuclear power plants. This paper is focused on the absorption performance of iodide vapour in the venturi scrubber, based on experiment and mathematical calculation. The results indicate that the absorption efficiency is closely related to solution flow rate, gas flow rate and temperature, but is not sensitive to iodide inlet concentration. When solution flow rate is low, the absorption efficiency increases rapidly with increasing the solution flow rate, and when the solution is excessive, the absorption efficiency remains around 99% stably; the influence of gas flow rate on absorption efficiency is mainly reflected in the variation of gas and liquid contacting time; when the solution flow rate is low, the increase of gas flow rate will led to an obvious decrease in absorption efficiency; temperature is not important when gas flow rate in constant but becomes effective for improving the absorption efficiency when gas velocity is constant. The proposed mathematical model can predict the iodide absorption process well in the range of experimental conditions. Especially, in the condition of lower gas flow rate and higher solution flow rate, the prediction accuracy is more satisfactory; however the accuracy of prediction will decrease at higher gas flow rates and lower solution flow rates because of neglecting the transverse exchange between gas and liquid phase.

The 11C-radioisotopic study of methanol conversion on V-MCM-41; the influence of methyl iodide on the transformation

International Nuclear Information System (INIS)

Sarkadi-Priboczki, E.; Szelecsenyi, F.; Kovacs, Z.; Solmaz, A.; Balci, S.; Dogu, T.

2007-01-01

Complete text of publication follows. The MCM-41 mesoporous material has Lewis and even Bronsted acid sites to produce dimethyl ether with some hydrocarbons, while over metal modified MCM-41 mostly formaldehyde and dimethoxy methane (i.e. methylal) or methyl formate are produced. In present experiments V incorporated basically mild acid sites of MCM-41 was prepared by low temperature direct synthesis. The V-MCM-41 has enough main active Lewis sites (by V-) to form formaldehyde and also light Bronsted acid sites to let the adsorbed formaldehyde eliminate and afterwards, with methanol, to form dimethoxy methane in nonoxidative environment. This V-MCM-41 has been tested by ethanol conversion in non-oxidative environments too and diethoxy methane as main product was detected. In present work the methanol conversion, as well as the methanol co-reaction with methyl iodide are studied from the same V-MCM-41 sample using 11 C-technique. The 11 C-labelled radioactive methanol has been already applied for determination of methanol conversion rates on Cu-modified MCM-41. The V-MCM-41 was prepared by direct hydrothermal synthesis method. The adsorption rate of 11 C-methanol and, after the reaction, the desorption rate of the remaining 11 C-derivatives on catalyst were continuously detected by gamma detectors. The derivatives were analyzed by radio-gas chromatography (gas chromatograph with FID coupled on-line with a radioactivity detector). Both dimethyl ether and hydrocarbon formation are also in slight degrees according to weak Lewis and Bronsted acidities. Since the conversion was carried out without added oxygen gas, only the frame oxygen can take part into catalysis. In presence of non-radioactive methyl iodide, the radioactive methanol is converted to radioactive methyl iodide on V-MCM-41. The radio-GC analysis confirmed that the iodide induced change of the reaction performance was reversible i.e. the radioactive methyl iodide was regenerated to non-radioactive methyl

New Microporous Polymer Electrolyte Based on Polysiloxane Grafted with Imidazolium Iodide Moieties for DSSC

Directory of Open Access Journals (Sweden)

Yan Yang

2011-01-01

Full Text Available Two types of polysiloxane grafted with different ratio of imidazolium iodide moieties (IL-SiO2 have been synthesized to develop a micro-porous polymer electrolyte for quasi-solid-state dye-sensitized solar cells. The samples were characterized by 1HNMR, FT-IR spectrum, XRD, TEM and SEM, respectively. Moreover, the ionic conductivity of the electrolytes was measured by electrochemical workstation. Nanostructured polysiloxane containing imidazolium iodide showed excellent compatibility with organic solvent and polymer matrix for its ionic liquid characteristics. Increasing the proportion of imidazolium iodide moieties in polysiloxane improved the electrochemical behavior of the gel polymer electrolyte. A dye-sensitized solar cell with gel polymer electrolyte yielded an open-circuit voltage of 0.70 V, short-circuit current of 11.19 mA cm−2, and the conversion efficiency of 3.61% at 1 sun illumination.

Behavior of technetium in alkaline solution: Identification of non-pertechnetate species in high-level nuclear waste tanks at the Hanford reservation

International Nuclear Information System (INIS)

Lukens, Wayne W. Jr.; Shuh, David K.; Schroeder, Norman C.; Ashley, Kenneth R.

2003-01-01

Technetium is a long-lived (99Tc: 213,000 year half-life) fission product found in nuclear waste and is one of the important isotopes of environmental concern. The known chemistry of technetium suggests that it should be found as pertechnetate, TcO4-, in the extremely basic environment of the nuclear waste tanks at the Hanford site. However, other chemical forms of technetium are present in significant amounts in certain tanks, and these non-pertechnetate species complicate the treatment of the waste. The only spectroscopic characterization of these non-pertechnetate species is a series of X-ray absorption near edge structure (XANES) spectra of actual tank waste. To better understand the behavior of technetium under these conditions, we have investigated the reduction of pertechnetate in highly alkaline solution in the presence of compounds found in high-level waste. These results and the X-ray absorption fine structure (XAFS) spectra of these species are compared to the chemical behavior and XANES spectra of the actual non-pertechnetate species. The identity of the nonpertechnetate species is surprising

Labelling of metaiodobenzylguanidine (MIBG) with Technetium-99m radionuclide

International Nuclear Information System (INIS)

Maula Eka Sriyani; Dini Natanegara; Aang Hanafiah Ws

2015-01-01

Various neuroendocrine tumors and their metastases are able to localized and staged by Metaiodobenzylguanidine (MIBG). MIBG is a molecule that has a chemical structure similarities with noradrenaline in the adrenal. The research on 131 I-MIBG has been successfully conducted in the tumor imaging. This research of preparing 99m Tc-MIBG that will be used as a diagnostic agent for adrenal tumors was carried out. MIBG labeling activities with technetium-99m radionuclide were carried out through labeling of MIBG with technetium-99m and radiochemical purity analysis. The labeling of MIBG was carried out using both direct and indirect methods with diethylene triamine pentaacetic acid (DTPA) as a co-ligand. Determination of 99m Tc-MIBG labeling efficiency was performed using paper chromatography with Whatman 3MM/dried acetone and Whatman 31ET/acetonitrile 50%. The results of labeling efficiency using the indirect method with DTPA as a co-ligand was obtained 93.44 ± 1.93%, which the concentration of MIBG was 2 mg/0.5 mL H 2 O, concentration of co-ligand was 37,5 μg of SnCl 2 .2H 2 O and DTPA of 1,125 mg at pH 6.5 for 15 minutes incubation in the room temperature ( 25 °C). (author)

Parallel critical magnetic fields of superconducting hyperthin films of vanadium and technetium

International Nuclear Information System (INIS)

Teplov, A.A.; Mikheeva, M.N.

1980-01-01

The nature of limiting parallel magnetic fields Hsub(c parallel) destroying a superconducting state in films of vanadium and technetium is found out. A dependence of Hsub(c parallel) on the thickness of films up to d approximately 60 A is studied. The |dHsub(c parallel)sup(2)/dT|sub(Tsub(c)) derivative, which increases in the region of large d with the increase of 1/d and achieves the maximum va;ue at d approximately 100 A, was determined, using the experimental data. For the most thin films this derivative tends to drop (the value of the derivative changes from 16 up to 20.00 kOe 2 /k and for technetium and from 4 up to 2100 kOe 2 /k for vanadium). Such stop at |dHsub(c11)sup(2)/ dT|sub(Tsub(c)) growth during the decrease of d is not explained in the framework of the theory taking into account only orbital effects. An account of the additional paramagnetic effect (spin effects) leads to a good agreement of the experiment with the theory in the whole range of thicknesses for vanadium. For technetium films in the d range <=110 A the value of Hsub(c parallel) exceeds several times Hsub(c parallel) calculated with provision of spin effects. For d approximately 80 A and d approximately 55 A this increase achieves the triple value. This effect is explained qualitatively by the spin-orbital scattering appearing with the increase of the atomic number

Technetium /sup 99m/Tc macroaggregated albumin lung scans. Use in chronic childhood asthma

International Nuclear Information System (INIS)

Hyde, J.S.; Koch, D.F.; Isenberg, P.D.; Werner, P.

1976-01-01

Serial roentgenograms and technetium /sub 99m/Tc macroaggregated albumin lung scans were done simultaneously in 30 bronchodilator-dependent asthmatic children and young adults during both relative remission and attacks of status asthmaticus. When chest roentgenograms showed air trapping and increased peribronchial vascular markings associated with persistent perfusion defects, the children benefited from further laboratory studies and continuous comprehensive therapy. Serial scans provided information about underperfusion that was not discernible either by roentgenograms or by usual blood gas studies. Also, lung scans are easier to obtain in children with long-standing asthma than are detailed pulmonary tests. In our study, technetium /sup 99m/Tc macroaggregated albumin scans showed persistent regional perfusion defects in 20 children with chronic asthma during relative remission and exacerbations

Peculiarities of the introduction of technetium isotopes into protein molecules - of human serum albumin as an example

International Nuclear Information System (INIS)

Stanko, V.I.; Ovsyannikov, N.N.; Zuykova, N.P.; Gouskov, A.F.; Kovalchouk, N.D.

1978-07-01

Pecularities of the introduction of the radioisotope technetium 99m into the molecules of human serum albumin have been investigated. Tin not only participates in the Tc(V11) reduction process, but is incorporated into the originating Tc albumin complex. It is shown that no more than four technetium atoms enter into bond with an albumin molecule. The authors express their opinion that in order to produce high-quality protein preparations, the albumin has to be modified through a polyfunctional complexing agent which forms an entirely saturated coordination complex with Tc(IV)

Pecularities of the introduction of technetium isotopes into protein molecules using human serum albumin as an example

International Nuclear Information System (INIS)

Stanko, V.I.; Ovsyannikov, N.N.; Sujkova, N.P.; Gus'kov, A.F.; Koval'chuk, N.D.

1978-01-01

Pecularities of the introduction of the radioisotope technetium 99m into the molecules of human serum albumin have been investigated. Tin not only participates in the Tc(VII) reduction process, but is incorporated into the originating Tc albumin complex. It is shown that no more than four technetium atoms enter into bond with an albumin molecule. The authors express their opinion that in order to produce high-quality protein preparations, the albumin has to be modified through a polyfunctional complexing agent which forms an entirely saturated coordination complex with Tc(IV). (author)

Development of Assessment Methodology of Chemical Behavior of Volatile Iodide under Severe Accident Conditions Using EPICUR Experiments

International Nuclear Information System (INIS)

Oh, Jae Yong; Yun, Jong Il; Kim, Do Sam; Han Chul

2011-01-01

Iodine is one of the most important fission products produced in nuclear power plants. Under severe accident condition, iodine exists as a variety of species in the containment such as aqueous iodide, gaseous iodide, iodide aerosol, etc. Following release of iodine from the reactor, mostly in the form of CsI aerosol, volatile iodine can be generated from the containment sump and release to the environment. Especially, volatile organic iodide can be produced from interaction between nonvolatile iodine and organic substances present in the containment. Volatile iodide could significantly influence the alienated residents surrounding the nuclear power plant. In particular, thyroid is vulnerable to radioiodine due to its high accumulation. Therefore, it is necessary for the Korea Institute of Nuclear Safety (KINS) to develop an evaluation model which can simulate iodine behavior in the containment following a severe accident. KINS also needs to make up its methodology for radiological consequence analysis, based on MELCOR-MACCS2 calculation, by coupling a simple iodine model which can conveniently deal with organic iodides. In the long term, such a model can contribute to develop an accident source term, which is one of urgent domestic needs. Our strategy for developing the model is as follows: 1. Review the existing methodologies, 2. Develop a simple stand-alone model, 3. Validate the model using ISTP-EPICUR (Experimental Program on Iodine Chemistry under Radiation) and OECD-BIP (Behavior of Iodine Project) experimental data. In this paper we present the context of development and validation of our model named RAIM (Radio-active iodine chemistry model)

Development of Assessment Methodology of Chemical Behavior of Volatile Iodide under Severe Accident Conditions Using EPICUR Experiments

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae Yong; Yun, Jong Il [KAIST, Daejeon (Korea, Republic of); Kim, Do Sam; Han Chul [Korea Institue of Nuclear Safety, Daejeon (Korea, Republic of)

2011-05-15

Iodine is one of the most important fission products produced in nuclear power plants. Under severe accident condition, iodine exists as a variety of species in the containment such as aqueous iodide, gaseous iodide, iodide aerosol, etc. Following release of iodine from the reactor, mostly in the form of CsI aerosol, volatile iodine can be generated from the containment sump and release to the environment. Especially, volatile organic iodide can be produced from interaction between nonvolatile iodine and organic substances present in the containment. Volatile iodide could significantly influence the alienated residents surrounding the nuclear power plant. In particular, thyroid is vulnerable to radioiodine due to its high accumulation. Therefore, it is necessary for the Korea Institute of Nuclear Safety (KINS) to develop an evaluation model which can simulate iodine behavior in the containment following a severe accident. KINS also needs to make up its methodology for radiological consequence analysis, based on MELCOR-MACCS2 calculation, by coupling a simple iodine model which can conveniently deal with organic iodides. In the long term, such a model can contribute to develop an accident source term, which is one of urgent domestic needs. Our strategy for developing the model is as follows: 1. Review the existing methodologies, 2. Develop a simple stand-alone model, 3. Validate the model using ISTP-EPICUR (Experimental Program on Iodine Chemistry under Radiation) and OECD-BIP (Behavior of Iodine Project) experimental data. In this paper we present the context of development and validation of our model named RAIM (Radio-active iodine chemistry model)

Tandem on-line continuous separations for atomic spectroscopic indirect analysis: iodide determination by ICP-AES

International Nuclear Information System (INIS)

Garcia, A.M.; Sanchez Uria, J.E.; Sanz-Medel, A.; Quintero Ortega, M.C.; Bautista, J.C.

1992-01-01

A sensitive and selective indirect determination of iodide by inductively coupled plasma emission spectrometry (ICP-AES) based on the principle of tandem on-line continuous separations as an alternative means of introducing samples into plasmas is proposed. Iodide is continuously extracted as an ion-pair into xylene by mixing the sample with Hg(II) and dipyridil solutions. The organic phase (containing the analyte in [Hg(Dipy) 2 ]I 2 form) is on-line continuously mixed with NaBH 4 (in DMF) and acetic acid solutions. Mercury vapour continuously generated from this organic phase is separated in a classical U-type gas-liquid separation device. The system has been optimized for the continuous extraction of KI, for the direct generation of cold mercury vapour from xylene and for the final ICP-AES determination of mercury. The optimised method has been applied to the determination of iodide (detection limit 20 ng/ml of iodide) in table salt and in synthetic samples. Very good agreement between found and certified results was observed. The usefulness and convenience of such alternative sample chemical pretreatment/presentation to the ICP is thus demonstrated for indirect determinations to be carried out by atomic spectroscopy methods. (authors)

A highly sensitive PVC membrane iodide electrode based on complexes of mercury(II) as neutral carrier.

Science.gov (United States)

Chai, Y-Q; Yuan, R; Xu, L; Xu, W-J; Dai, J-Y; Jiang, F

2004-09-01

A novel solvent polymeric membrane electrode based on bis(1,3,4-thiadiazole) complexes of Hg(II) is described which has excellent selectivity and sensitivity toward iodide ion. The electrode, containing 1,4-bis(5-methyl-1,3,4-thiadiazole-2-yl-thio)butanemercury(II) [Hg(II)BMTB(NO3)4], has a Nernstian potentiometric response from 2.0 x 10(-8) to 2.0 x 10(-2) mol L(-1) with a detection limit of 8.0 x 10(-9) mol L(-1) and a slope of -59.0+/-0.5 mV/decade in 0.01 mol L(-1) phosphate buffer solution (pH 3.0, 20 degrees C). The selectivity sequence observed is iodide>bromide>thiocyanate>nitrite>nitrate>chloride>perchlorate>acetate>sulfate. The selectivity behavior is discussed in terms of the UV-Vis spectrum, and the process of transfer of iodide across the membrane interface is investigated by use of the AC impedance technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains, with satisfactory results.

Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect

Directory of Open Access Journals (Sweden)

Wakako Jo

2010-01-01

Full Text Available Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD. Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although 123I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

Forefront of PUREX system engineering. Chemistry and engineering of ruthenium, technetium and neptunium

International Nuclear Information System (INIS)

2004-07-01

The paper reports the activity of the research committee organized by the Atomic Energy Society of Japan on 'Ruthenium and Technetium Chemistry in the PUREX System', with focusing on basic behaviors of ruthenium, technetium and neptunium in the PUREX process, the principles of plant design, and behaviors during the final waste treatment. The scope of the work includes the following major topics: (1) basic solution and solid-state chemistry; (2) basic solution and solid-state chemistry of minor actinides in particular, Np; (3) partitioning chemistry in the PUREX system and environmental behavior of the components; (4) processes of recovery, purification, and utilization of rare metal fission products; (5) field data on plant design, operation, decontamination, and decommissioning; (6) numerical process simulations and process control technologies; (7) compilation of a data base for process chemistry and plant engineering. (S. Ohno)

Stripping voltammetry of technetium using a TOA modified carbon paste electrode

International Nuclear Information System (INIS)

Ruf, H.; Schorb, K.

1989-10-01

Low concentrations of technetium have been measured DP-stripping-voltammetrically using a carbon paste electrode modified with tri-n-octylamine (TOA-CPE). Preconcentration of the metal ion on the electrode surface accomplished by dipping of the latter in the sample solution which is 2M in HCl, relies on the chemical reaction with the amine acting as a liquid anion exchanger. Both, Tc-IV occurring as the TcCl 6 2- ion in chloride solutions as well as Tc-VII hereby are deposited. Measurements following deposition yield voltammograms of essentially different shapes for the two Tc species. With Tc-IV a characteristic curve with a prominent current signal at -280 mV (vs. Ag/AgCl) is obtained which can be evaluated for Tc quantitation. However, starting from Tc-VII, complex voltammograms are registered not allowing direct technetium assays. Nevertheless, after reduction to Tc-IV, e.g. by means of ascorbic acid, also Tc-VII can be quantified reliably by the method described, the lower detection limit for both oxidation states being about 4x10 -8 M. (orig.) [de

Diagnostic value of technetium pyrophosphate bone scintigraphy. Study of 277 patients

International Nuclear Information System (INIS)

Sainte-Croix, Annick.

1975-01-01

277 bone scintigraphs were carried out with 99m technetium pyrophosphate and an attempt was made, on the basis of this experience, to define the advantages and limits of the technique. 99m technetium pyrophosphate seems to be the isotope most suitable for bone scintigraphy. The scintillation camera bone scintigraphic examination is simple, allowing the whole skeleton to be explored in a relatively short time, and above all harmless since the total irradiation to which the organism is exposed throughout is no more than 0.07 rad. The broadest field of application of bone scintigraphy appears to be cancer: in 45 cases out of 66 it revealed bone metastases invisible radiologically and in 28 cases out of 90 the number of metastases observed was greater than that shown by X-rays. In 11 cases however radiologically visible bone metastases were not detected by scintigraphy. In spite of this reservation we consider bone scintigraphy to be a valuable technique, more sensitive than X-ray examinations in the detection of bone metastases of cancers [fr

Determination of microamounts of potassium in sodium iodide by atomic absorption spectrometry

International Nuclear Information System (INIS)

Ogasawara, Ken; Ohta, Masatoshi; Abe, Kenzo

1980-01-01

Microdetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30% hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 0 -- 1 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 0 -- 2 mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of +-(20 -- 3)% in the range (1.7 -- 32.5) ppm. (author)

Removal of technetium, carbon tetrachloride, and metals from DOE properties. 1998 annual progress report

International Nuclear Information System (INIS)

Darab, J.G.; Mallouk, T.E.; Ponder, S.M.

1998-01-01

'The objective of the project is to develop and characterize supported reducing agents, and solid waste forms derived from them, which will be effective in the removal of transition metal ions, chlorinated organic molecules, and technetium from aqueous mixed wastes. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (chromium, mercury, and lead) and rhenium (as a surrogate for technetium) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for the supported iron aggregates that will optimize their selectivity for the contaminants of interest. The support composition is of particular interest in the case of technetium (Tc) separation and stabilization in the Hanford tank wastes. While it is expected that pertechnetate will be reduced insoluble TcO 2 , the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes. This report summarizes progress in the first 8 months of a 3-year collaborative project involving Penn State and Pacific Northwest National Laboratory (PNNL).'

Comparison of two novel in-syringe dispersive liquid-liquid microextraction techniques for the determination of iodide in water samples using spectrophotometry.

Science.gov (United States)

Kaykhaii, Massoud; Sargazi, Mona

2014-01-01

Two new, rapid methodologies have been developed and applied successfully for the determination of trace levels of iodide in real water samples. Both techniques are based on a combination of in-syringe dispersive liquid-liquid microextraction (IS-DLLME) and micro-volume UV-Vis spectrophotometry. In the first technique, iodide is oxidized with nitrous acid to the colorless anion of ICl2(-) at high concentration of hydrochloric acid. Rhodamine B is added and by means of one step IS-DLLME, the ion-pair formed was extracted into toluene and measured spectrophotometrically. Acetone is used as dispersive solvent. The second method is based on the IS-DLLME microextraction of iodide as iodide/1, 10-phenanthroline-iron((II)) chelate cation ion-pair (colored) into nitrobenzene. Methanol was selected as dispersive solvent. Optimal conditions for iodide extraction were determined for both approaches. Methods are compared in terms of analytical parameters such as precision, accuracy, speed and limit of detection. Both methods were successfully applied to determining iodide in tap and river water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

129I- and 99TcO4-scavengers for low level radioactive waste backfills

International Nuclear Information System (INIS)

Balsley, S.D.; Brady, P.V.; Krumhansl, J.L.; Anderson, H.L.

1997-03-01

Minimization of 129 I - and 99 TcO 4 - transport to the biosphere is critical to the success of low level radioactive waste (LLRW) storage facilities. Here we experimentally identify and classify optimal sorbent materials for inclusion in LLRW backfills. For low pH conditions (pH 4-5), Cu-sulfides and possibly imogolite-rich soils provide K d 's (surface-solution partition coefficients) of roughly 10 3 ml g -1 for iodide, and 10 2 ml g -1 for technetium. At near neutral pH, hydrotalcites, Cu-oxides, Cu-sulfides and lignite coal possess K d 's on the order of 10 2 ml g -1 for both iodine and technetium. At high pH (pH > 10), such as might occur in a cementitious LLRW facility, calcium monosulfate aluminate K d 's are calculated to be roughly 10 2 ml g -1 for both iodine and technetium

Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-102

International Nuclear Information System (INIS)

Hassan, N.M.

2000-01-01

The pretreatment process for BNFL, Inc.'s Hanford River Protection Project is to provide decontaminated low activity waste and concentrated eluate streams for vitrification into low and high activity waste glass, respectively. The pretreatment includes sludge washing, filtration, precipitation, and ion exchange processes to remove entrained solids, cesium, transuranics, technetium, and strontium. The cesium (Cs-137) and technetium (Tc-99) ion exchange removal is accomplished by using SuperLig 644, and 639 resins from IBC Advanced Technologies, American Fork, Utah. The resins were shown to selectively remove cesium and technetium (as anionic pertechnetate ) from alkaline salt solutions. The efficiency of ion exchange column loading and elution is a complex function involving feed compositions, equilibrium and kinetic behavior of ion exchange resins, diffusion, and the ionic strength and pH of the aqueous solution. A previous experimental program completed at the Savannah River Tech nology Center2 demonstrated the conceptualized flow sheet parameters with an Envelope C sample from Hanford Tank 241-AN-107. Those experiments also included determination of Cs and Tc batch distribution coefficients by SuperLig 644 and 639 resins and demonstration of small-scale column breakthrough and elution. The experimental findings were used in support of preliminary design bases and pretreatment flow sheet development by BNFL, Inc

76 FR 16770 - Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide...

Science.gov (United States)

2011-03-25

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0541; FRL-8841-7] Petition To Suspend and Cancel... Earthjustice requesting that all uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is... uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is posting this petition for...

Environmental behavior of technetium-99 and iodine-129

International Nuclear Information System (INIS)

Garland, T.R.; Schreckhise, R.G.

1982-01-01

The environmental behavior of technetium-99 and iodine-129 was once thought to be similar, particularly with respect to their soil solubility and biological interactions. Over the past several years, the comparative behavior of these two anions has been studied with respect to their fate in natural environments (both aquatic and terrestrial). The mechanisms studied include physical, chemical and biological parameters that account for differences in soil behavior, cycling between soil and/or air to vegetation, adsorption and metabolism in plants, and their availability and fate following ingestion by animals

Preparation of L-asparagine complex with technetium

International Nuclear Information System (INIS)

Persano, S.C.M.

1981-01-01

The preparation of technetium chelated to L-asparagine is aimed at for obtention of potentially useful radiopharmaceutical in nuclear medicine. The reduction of pertechnetate anion ( 99 TcO - 4 and sup(99m) TcO - 4 ) using hydrazine as a reducing agent is studied with use of polarographic spectrophotometric and chromatographic methods. Spectrophotometric determination shows that the aqueous solution of amonium sup(-99m) Tc pertechnetate absorbs at 244, 248 and 290 nm. After reduction the species absorbs at 330 and near 495-530 nm. Polarographic measurements with 0,1 N NaOH electrolyte show a half-wave potential E sub(1/2 = -0,82 V for technetium +VII. After the addition of increasing amounts of hydrazine into a solution containing Tc+VII, the half wave potential shifts to more positives values, indicating the reduction of Tc+VII. Chromatographic determinations are in good agreement with polarographic analysis, emphatizing reduction of Tc+IV by hydrazine. The reduced 99 Tc shows ability of being incorporated into L-asparagine forming a cristalline compound with melting point 118.6 0 C. Infrared absorption spectrometry shows that amino and carboxyl groups are bound to the metal in this complex. The yield of sup(99m) Tc incorporation into L-asparagine at 60 0 C in 30 minutes is up to 95%. The labeled complex can be presented as a radiopharmaceutical product. Tissue distribution performed in groups of normal and bearing lymphoma Walker 256 Wistar rats (50-60) shows that the radiopharmaceutical concentrates seletively in the tumor and is fastly excreted by the kidney and it doesn't have significant affinity for any organ, being so adequate for the formation of tumoral images. (Authors) [pt

Anionic sorbents for arsenic and technetium species

International Nuclear Information System (INIS)

Lucero, Daniel A.; Moore, Robert Charles; Bontchev, Ranko Panayotov; Hasan, Ahmed Ali Mohamed; Zhao, Hongting; Salas, Fred Manuel; Holt, Kathleen Caroline

2003-01-01

Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption

Theoretical and experimental investigations on the behaviour of iodine during severe accidents: organic iodide, iodine/silver reaction, iodine/iron reaction. Pt. 4: organic iodide. Final report

International Nuclear Information System (INIS)

Hellmann, S.; Greger, G.U.; Funke, F.; Bleier, A.; Zeeh, W.

1995-11-01

Analysis of the consequences of severe accidents in nuclear power plants requires knowledge of the behaviour of radionuclides relevant from the radiological viewpoint. The role played by radioiodine is particularly important. In the current modelling of iodine behaviour the heterogeneous formation of organic iodide is not adequately taken into consideration owing to a lack of data or insufficient accuracy of data. This project is intended to eliminate some gaps in critical areas. This final report, part 4, describes the tests carried out in the two relevant areas - heterogeneous formation of organic coatings in the gas phase (containment atmosphere) - heterogeneous formation of organic iodide at organic coatings in aqueous phase (containment sump). Moreover, modelling suggestions how to include the resulting knowledge in the iodine accident behaviour code IMPAIR are given. (orig.) [de

Effect of radioiodine irradiation of thyroid gland in vitro with a dose of 4-5 Gy on iodide transport in thyrocytes

International Nuclear Information System (INIS)

Paster, Yi.P.

2000-01-01

We study the influence of ouabain on the basal and thyrotropin-stimulated iodide uptake in thyroid gland preliminarily irradiated by radioiodine (absorbed dose: 4-5 Gy) in vitro. Newborn pig thyroid tissue was incubated in a medium, containing 37 kBq/ml of 131-iodine (absorbed dose: 4-5 Gy), washed and achieved by collagenase dissociation. Thyrocytes were incubated with thyrotropin (100.0 mE/ml), ouabain (0.1 mol/l), and 125-iodide (0.4 kBq/ml). Then cells were washed, stored at 4 degree C for 60 days, and the 125-iodide uptake was assessed. Ouabain depressed both the basal and thyrotropin-stimulated iodide uptakes by thyrocytes in vitro. After preliminary radioiodine irradiation of the thyroid tissue (absorbed dose: 4-5 Gy), ouabain stimulated both the basal and thyrotropin-stimulated iodide uptakes by thyrocytes

Under used technetium-99m generators

International Nuclear Information System (INIS)

Mushtaq, A.

2001-01-01

Health care reform truly has become a global issue and it will undoubtedly have a dramatic impact on the future of nuclear medicine business in particular. A bigger concern within the nuclear medicine community is its competitiveness with other modalities and cost effectiveness.Technetium-99m and its generators are playing key role for the majority of diagnostic scans performed in the world today. Availability of ''9''9''mTc can be increased if it is separated from ''9''9Mo after much shorter growth times. After proper planning with the extra ''9''9''mTc, a significant number of scans can be performed or we would be able to order approximately 30% low activity ''9''9Tc generators to fulfill our requirements

Epidemiology of thyroid disorders and valuation of effects of iodide administration in the Sejny community (Poland) after Chernobyl accident

International Nuclear Information System (INIS)

Zimnicki, P.

1993-01-01

The epidemiology of thyroid disorders was studied and the effect of potassium iodide administration was evaluated in citizens of Sejny (Poland) community four years after Chernobyl accident. The endemic goiter was observed in this area. The elevated levels of anti-human thyroid membrane antibodies and anti-human thereoglobuline antibody were found in 5.5% of children that had undergone iodide administration after Chernobyl accident. It may result from iodide administration or from endemic goiter. (author). 127 refs, 9 figs, 16 tabs

Synthesis and antimicrobial activity of guanylhydrazones. Synthesis of 2-(2-methylthio-2-aminovinyl)-1-methylpyridinium iodides and 2-(2-methylthio-2-aminovinyl)-1-methylquinolinium iodides as potential radioprotective and anticancer agents

International Nuclear Information System (INIS)

Almassian, B.

1985-01-01

The finding of appreciable antileukemic activity in a series of 2-(2-methylthio-2-amino)vinyl-1-methylquinolinium iodides (Foye et al., 1980, 1983) suggested that greater basicity, as compared with the corresponding dithioacetic acids, was contributing to the increase in activity. The addition of a greater degree of basicity in the design of anticancer possibilities in this series was considered worth investigation, particularly in view of the activity of a series of bis(quanylhydrazones) synthesized at Lederle Laboratories. Accordingly, a series of guanylhydrazones of 4-pyridine-,2-pyridine- and 4-quinolinecarboxyaldehydes was synthesized for anticancer as well as antibacterial screening. Also, substitution of additional basic functions in the 2-(2-methylthio-2-amino) vinyl-1-methylquinolinium and pyridinium iodide series has been made. Appreciable antimicrobial activities have been found with both 2-pyridine and 4-quinolinealdehyde guanylhydrazones, as well as with 2-(2-methylthio-2-amino)vinyl-1-methyl-pyridinium iodides. The overall approach to the synthesis of potential anticancer agents in this project is thus to observe the effect of increasing basicity of these compounds on DNA binding and anticancer activity

Evaluation of experimental studies on technetium transfers to sediments and benthic marine species, and comparison with in situ data

Energy Technology Data Exchange (ETDEWEB)

Aprosi, G [Electricite de France, 78 - Chatou; Masson, M [Commisariat a l' Energie Atomique, Institut de Protection et de Surete Nucleaire, 50 - Cherbourg (France)

1984-01-01

To obtain basic information for the evaluation of the radiological impact of technetium (Tc) on the marine environment, investigations are performed by different laboratories. Technetium is not a natural element and the main source of production is the nuclear fuel cycle. Under anoxic conditions, in presence of reducing sediments, the distribution coefficients are very high (Ksub(D)=10/sup 3/). Concentration factors from water to species are mostly very low (FC 1 to 10); however, concentration factors up to 1000 have been observed for a few species such as macrophytic brown algae, worms and lobster. Biochemical analysis shows that Tc is bound with protein. The transfer factors between sediment and species are very low (FT<0,5). The biological half-life (Tb) was determined in some marine organisms which had accumulated the radionuclide from water-contamined food or from sediments. The loss is biphasic in storage organs (liver and kidney); uptake in the edible parts is low. Among the parameters studied (light for algae, physico-chemical form of Tc, salinity and temperature) only light and the physico-chemical forms have an effect on the accumulation of technetium. Analyses of /sup 99/Tc concentrations in species collected near the La Hague and Windscale (Sellafield) reprocessing plants confirm the experimental studies. Since sea water is likely to be an oxidant environment, technetium appears as a conservative element.

Monoclonal anti-elastin antibody labelled with technetium-99m

International Nuclear Information System (INIS)

Oliveira, Marcia B.N. de; Silva, Claudia R. da; Araujo, Adriano C. de; Bernardo Filho, Mario; Porto, Luis Cristovao M.S.; Gutfilen, Bianca; Souza, J.E.Q.; Frier, Malcolm

1999-01-01

Technetium-99m ( 99m Tc) is widely employed in nuclear medicine due to its desirable physical, chemical and biological properties. Moreover, it is easily available and normally is inexpensive. A reducing agent is necessary to label cells and molecules with 99m Tc and stannous chloride (Sn C L 2 ) is usually employed. Elastin is the functional protein component of the elastic fiber and it is related with some diseases such as arteriosclerosis, pulmonary emphysema and others. The present study refers to the preparation of the 99m Tc labeled monoclonal anti-elastin antibody. The monoclonal antibody was incubated with an excess of 2-iminothiolane. The free thiol groups created, were capable of binding with the reduced technetium. Labeling was an exchange reaction with 99m Tc-glucoheptonate. The labeled preparation was left at 4 deg C for one hour. Then, it was passed through a Sephadex G50 column. Various fractions were collected and counted. A peak corresponding to the radiolabeled antibody was obtained. Stability studies of the labelled anti-elastin were performed at 0,3 6, 24 hours, at both 4 deg C or room temperature. The biodistribution pattern of the 99m Tc-anti-elastin was studied in healthy male Swiss mice. The immunoreactivity was also determined. An useful labeled-anti-elastin was obtained to future immunoscintigraphic investigations. (author)

Temperature Dependent Charge Carrier Dynamics in Formamidinium Lead Iodide Perovskite

NARCIS (Netherlands)

Gelvez Rueda, M.C.; Renaud, N.; Grozema, F.C.

2017-01-01

The fundamental opto-electronic properties of organic-inorganic hybrid perovskites are strongly affected by their structural parameters. These parameters are particularly critical in formamidinium lead iodide (FAPbI₃), in which its large structural disorder leads to a non-perovskite

Relaxation of the silver/silver iodide electrode in aqueous solution

NARCIS (Netherlands)

Peverelli, K.J.

1979-01-01

The aim of this study is to detect and characterize relaxation processes on silver/silver iodide electrodes in aqueous electrolyte solution. The information obtained is to be used for an estimation of the consequences of similar processes on colloidal AgI

Growth of mercuric iodide single crystals from dimethylsulfoxide

International Nuclear Information System (INIS)

Carlston, R.C.

1976-01-01

Dimethylsulfoxide is used as a solvent for the growth of red mercuric iodide (HgI 2 ) crystals for use in radiation detectors. The hygroscopic property of the solvent allows controlled amounts of water to enter into the solvent phase and diminish the large solubility of HgI 2 so that the precipitating solid collects as well-defined euhedral crystals which grow into a volume of several cc

Study of adsorption properties of impregnated charcoal for airborne iodine and methyl iodide

International Nuclear Information System (INIS)

Qi-dong, L.; Sui-yuang, H.

1985-01-01

The adsorption characteristics of airborne radioiodine and methyl iodide on impregnated charcoal were investigated. The activated charcoal tested was made from home-made oil-palm shells, and KI and TEDA were used as impregnants. A new technique was used to plot the dynamic partial adsorption isotherm at challenge concentrations (concentration range of iodine: 1-20 ppm v/v). Some adsorption properties of the impregnated charcoal were estimated with the dynamic partial adsorption isotherm. The dependences of the adsorption capacity and penetration behavior for airborne iodine and methyl iodide on the ambient conditions (temperature, relative humidity, and superficial velocity) were studied

Overview of nuclear medicine and the role of technetium

International Nuclear Information System (INIS)

Eckelman, W.C.

1987-01-01

One of the driving forces for the elucidation of the chemistry of 99 Tc was the discovery of the Molybdenum Technetium generator. Since this generator system produces no-carrier-added 99 Tc, these studies at the nanomolar level mostly involve chromatography, and that analytical tool is then used to link the no-carrier added and carrier chemistry. These well-defined 99 Tc compounds are used in vivo to measure perfusion, but biochemical probes offer an exciting target for further exploration

Analysis of perchlorate, thiocyanate, nitrate and iodide in human amniotic fluid using ion chromatography and electrospray tandem mass spectrometry

International Nuclear Information System (INIS)

Blount, Benjamin C.; Valentin-Blasini, Liza

2006-01-01

Because of health concerns surrounding in utero exposure to perchlorate, we developed a sensitive and selective method for quantifying iodide, as well as perchlorate and other sodium-iodide symporter (NIS) inhibitors in human amniotic fluid using ion chromatography coupled with electrospray ionization tandem mass spectrometry. Iodide and NIS inhibitors were quantified using a stable isotope-labeled internal standards (Cl 18 O 4 - , S 13 CN - and 15 NO 3 - with excellent assay accuracy of 100%, 98%, 99%, 95% for perchlorate, thiocyanate, nitrate and iodide, respectively, in triplicate analysis of spiked amniotic fluid sample). Excellent analytical precision (<5.2% RSD for all analytes) was found when amniotic fluid quality control pools were repetitively analyzed for iodide and NIS-inhibitors. Selective chromatography and tandem mass spectrometry reduced the need for sample cleanup, resulting in a rugged and rapid method capable of routinely analyzing 75 samples/day. Analytical response was linear across the physiologically relevant concentration range for the analytes. Analysis of a set of 48 amniotic fluid samples identified the range and median levels for perchlorate (0.057-0.71, 0.18 μg/L), thiocyanate (<10-5860, 89 μg/L), nitrate (650-8900, 1620 μg/L) and iodide (1.7-170, 8.1 μg/L). This selective, sensitive, and rapid method will help assess exposure of the developing fetus to low levels of NIS-inhibitors and their potential to inhibit thyroid function

Interruption with the Migration of Iodide by GR(CT)

International Nuclear Information System (INIS)

Min, J. H.; Lee, J. K.; Jeong, J. T.

2012-01-01

The purpose of this study is to understand the influence of green rust on the migration of iodide. GR(CT) would be major corrosion product of iron near the seawater or saline layer in underground. The GR(CT) may play an important role in the retardation of the iodide migration in a deep geological environment due to it's anionic exchange reaction. In underground radioactive waste repository, the corrosion of iron canisters would be proceed as follows; Fe(II) and/or Fe(III) dissolved from iron containers → Fe(II)(OH) 2 and/or Fe(III)(OH) 3 → Green rust → Lepidocrocite or Magnetite → Goetite etc. Generally, the green rust has known to exist in environments close to the Fe(Π)/Fe(ΠΙ) transition zone or between the oxidized layer and reduced layer in the underground. As anion exchanger and strong reducer, the green rusts can affect the migration of anions, reactions involving green rusts were poorly studied in relation to the safety assessment of radioactive waste repository

The aqueous corrosion behavior of technetium - Alloy and composite materials

International Nuclear Information System (INIS)

Jarvinen, G.; Kolman, D.; Taylor, C.; Goff, G.; Cisneros, M.; Mausolf, E.; Poineau, F.; Koury, D.; Czerwinski, K.

2013-01-01

Metal waste forms are under study as possible disposal forms for technetium and other fission products. The alloying of Tc is desirable to reduce the melting point of the Tc-containing metal waste form and potentially improve its corrosion resistance. Technetium-nickel composites were made by mixing the two metal powders and pressing the mixture to make a pellet. The as-pressed composite materials were compared to sintered composites and alloys of identical composition in electrochemical corrosion tests. As-pressed samples were not robust enough for fine polishing and only a limited number of corrosion tests were performed. Alloys and composites with 10 wt% Tc appear to be more corrosion resistant at open circuit than the individual components based on linear polarization resistance and polarization data. The addition of 10 wt% Tc to Ni appears beneficial at open circuit, but detrimental upon anodic polarization. Qualitatively, the polarizations of 10 wt% Tc alloys and composites appear like crude addition of Tc plus Ni. The 1 wt% Tc alloys behave like pure Ni, but some effect of Tc is seen upon polarization. Cathodic polarization of Tc by Ni appears feasible based on open circuit potential measurements, however, zero resistance ammetry and solution measurements are necessary to confirm cathodic protection

The aqueous corrosion behavior of technetium - Alloy and composite materials

Energy Technology Data Exchange (ETDEWEB)

Jarvinen, G.; Kolman, D.; Taylor, C.; Goff, G.; Cisneros, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mausolf, E.; Poineau, F.; Koury, D.; Czerwinski, K. [Department of Chemistry, University of Nevada, Las Vegas, Las Vegas, NV 89154 (United States)

2013-07-01

Metal waste forms are under study as possible disposal forms for technetium and other fission products. The alloying of Tc is desirable to reduce the melting point of the Tc-containing metal waste form and potentially improve its corrosion resistance. Technetium-nickel composites were made by mixing the two metal powders and pressing the mixture to make a pellet. The as-pressed composite materials were compared to sintered composites and alloys of identical composition in electrochemical corrosion tests. As-pressed samples were not robust enough for fine polishing and only a limited number of corrosion tests were performed. Alloys and composites with 10 wt% Tc appear to be more corrosion resistant at open circuit than the individual components based on linear polarization resistance and polarization data. The addition of 10 wt% Tc to Ni appears beneficial at open circuit, but detrimental upon anodic polarization. Qualitatively, the polarizations of 10 wt% Tc alloys and composites appear like crude addition of Tc plus Ni. The 1 wt% Tc alloys behave like pure Ni, but some effect of Tc is seen upon polarization. Cathodic polarization of Tc by Ni appears feasible based on open circuit potential measurements, however, zero resistance ammetry and solution measurements are necessary to confirm cathodic protection.

Stripping voltammetric behavior of technetium at various chemically modified electrodes

International Nuclear Information System (INIS)

Dick, R.

1990-09-01

In monitoring of nuclear processing plants and storage facilities the necessity arises of assaying traces of the artificial radioactive element technetium. The oxidation states IV and VII are of particular interest. Stripping voltammetry is among the methods of assay which are suited for this purpose. It allows an enhanced selectivity to be achieved by preconcentration of the analyte and of an oxidation state of the analyte, respectively, at the electrode used. This specific enrichment is successful after appropriate chemical modification of the electrode through immobilization of a Tc-specific reagent. When various approaches of chemical modification of a glassy carbon electrode were examined, the tetraphenylarsonium chloride extractant, which is highly selective with respect to technetium, proved to be the best suited reagent, capable of fixation both by ionic and by covalent bonding on an electrodeposited polymer film. For ionic immobilization the reagent was reacted to m-sulfophenyltriphenyl arsonium and then bound to a copolymer of vinylferrocene and vinylpyridine, which had been provided with cations. It was possible to enrich Tc(VII) at such an electrode and to determine it by stripping voltammetry down to a concentration of 1x10 -8 M after 5 minutes enrichment time. (orig./EF) [de

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

Osteomyelitis and infarction in sickle cell hemoglobinopathies: differentiation by combined technetium and gallium scintigraphy

International Nuclear Information System (INIS)

Amundsen, T.R.; Siegel, M.J.; Siegel, B.A.

1984-01-01

Clinical records and scintigrams were reviewed of 18 patients with sickle cell hemoglobinophaties who had undergone combined technetium and gallium scintigraphy during 22 separate episodes of suspected osseous infection. The combined scintigrams were correctly interpreted as indicating osteomyelitis in four studies. Of 18 studies in patients with infarction, the combined scintigrams were correctly interpreted in 16 and showed either no local accumulation of Ga-67 or less accumulation than that of Tc-99m MDP at symptomatic sites. In the other two studies, the scintigrams were falsely interpreted as indicating osteomyelitis and showed congruent, increased accumulation of both Tc-99, MDP and Ga-67. This pattern must be considered indeterminate. Overall, the results indicate that the combination of technetium and gallium scintigraphy is an effective means to distinguish osteomyelitis from infarction in patients with sickle cell hemoglobinopathies

Candidate Low-Temperature Glass Waste Forms for Technetium-99 Recovered from Hanford Effluent Management Facility Evaporator Concentrate

Energy Technology Data Exchange (ETDEWEB)

Ding, Mei [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tang, Ming [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rim, Jung Ho [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chamberlin, Rebecca M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-07-24

Alternative treatment and disposition options may exist for technetium-99 (99Tc) in secondary liquid waste from the Hanford Direct-Feed Low-Activity Waste (DFLAW) process. One approach includes development of an alternate glass waste form that is suitable for on-site disposition of technetium, including salts and other species recovered by ion exchange or precipitation from the EMF evaporator concentrate. By recovering the Tc content from the stream, and not recycling the treated concentrate, the DFLAW process can potentially be operated in a more efficient manner that lowers the cost to the Department of Energy. This report provides a survey of candidate glass formulations and glass-making processes that can potentially incorporate technetium at temperatures <700 °C to avoid volatilization. Three candidate technetium feed streams are considered: (1) dilute sodium pertechnetate loaded on a non-elutable ion exchange resin; (2) dilute sodium-bearing aqueous eluent from ion exchange recovery of pertechnetate, or (3) technetium(IV) oxide precipitate containing Sn and Cr solids in an aqueous slurry. From the technical literature, promising candidate glasses are identified based on their processing temperatures and chemical durability data. The suitability and technical risk of three low-temperature glass processing routes (vitrification, encapsulation by sintering into a glass composite material, and sol-gel chemical condensation) for the three waste streams was assessed, based on available low-temperature glass data. For a subset of candidate glasses, their long-term thermodynamic behavior with exposure to water and oxygen was modeled using Geochemist’s Workbench, with and without addition of reducing stannous ion. For further evaluation and development, encapsulation of precipitated TcO2/Sn/Cr in a glass composite material based on lead-free sealing glasses is recommended as a high priority. Vitrification of pertechnetate in aqueous anion exchange eluent solution

The distribution of radioiodine administrated to pregnant mice and the effect of non radioactive iodide

International Nuclear Information System (INIS)

Okui, Toyo; Kobayashi, Satoshi

1987-01-01

Radioiodine, 131 I, which has a high fission yield in the nuclear reactor, is easily taken into the human body, accumilating in the thyroid gland, when released to the environment. 131 I was administrated orally to pregnant mice, and its transportation to the tissues, particularly the fetus, was examined closely. And further, the non-radioactive iodide, i.e., KI, was administrated to see its radiation protection effect. The transportation of 131 I to the fetus is the second highest, following the thyroid gland in the mother mouse. This transportation to the fetus becomes the higher, the larger the gestation period at which the 131 I administration is made. The administration of the non-radioactive iodide has large radiation protection effect in the thyroid gland of the mother mouse and of the fetus. But, depending on its concentration, the non-radioactive iodide may conversely increase overall exposure of the fetus. (Mori, K.)

Technetium scanning in Kaposi's sarcoma and its simulators

International Nuclear Information System (INIS)

Gunnoe, R.; Kalivas, J.

1982-01-01

The clinical picture of ulcerated purple plaques on the legs often suggests several diagnoses: Kaposi's sarcoma, stasis dermatitis, atrophie blanche (livedoid vasculitis), and a poorly understood condition called acroangiodermatitis of Favre-Chaix (pseudo-Kaposi's sarcoma). Even the skin biopsy may not always be conclusive. We describe our experience with three patients with pseudo-Kaposi's sarcoma, one with true Kaposi's sarcoma and two with atrophie blanche. Clinical and histopathologic similarities among these three conditions pointed up the need for additional confirmatory studies, i.e., isotope scanning. The technetium scan was positive in both Kaposi's sarcoma and pseudo-Kaposi's sarcoma but negative in atrophie blanche

Functionalized metal organic frameworks for effective capture of radioactive organic iodides

KAUST Repository

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Shi, Zhan; Chabal, Yves J.; Han, Yu; Li, Jing

2017-01-01

Highly efficient capture of radioactive organic iodides (ROIs) from off-gas mixtures remains a substantial challenge for nuclear waste treatment. Current materials utilized for ROI sequestration suffer from low capacity, high cost (e.g. use of noble

Doses to nurses by the technetium-99m, in private and public sector

International Nuclear Information System (INIS)

Bied, J.Ch.; Philippon, B.

1999-01-01

The global body dose due to the technetium is 1.2 and 1.9 mSv for the two nurses of the private sector. In the public sector, the level reached by the personnel is 0.75 mSv for the global body dose, and the only technetium (global body dose 1.4 and 2.1 mSv for the private sector, 0.95 for the public sector and for the whole of radiations measured by the O.P.R.I. film dosemeter. The doses received at the fingers level present higher levels in the private sector. But these values, 15.2 and 10.7 mSv by month, that is to say 180 mSv by year are the 2/5 of the maximum permissible value. The two persons of the private sector received whole body doses, higher that the doses of the public sector. These doses are about 1.2 to 1.9 these ones received in the public sector. (N.C.)

Kit development for labelling erythrocytes or leukocytes with technetium-99m in vitro

International Nuclear Information System (INIS)

Wang Xuebin; Han Quansheng; Wang Jingcheng; Mi Hongzhi

1996-01-01

This study developed a modified pre tinning method for labeling erythrocytes with technetium-99m in vitro using a kit which contains stannous chloride stabilized with geneticist acid (GA) in lyophilized form. This GA-kit a sterile closed system that does not require centrifugation,washing and separation of the RBCs. The kit is simple to use and labeling takes ∼ 30 min with a typical labeling efficiency of 97.3% ± 1.2% for 60 determinations. Imaging studies were performed in rabbit using GA-kit in vitro labeling procedure and PYP-kit in vivo labeling. It shows that the heart-to-background ratio with GA in vitro labeling were significantly higher than with in vivo labeling. Leukocytes labeling with technetium-99m using the same GA kit also was studied. The labeling efficiency was 20 ∼ 41%. Thus, the GA kit is versatile and cost-effective. (author). 21 refs., 5 figs., 2 tabs

Selenium-75 and technetium-95m biokinetics in rats at different physiological states

International Nuclear Information System (INIS)

Archimbaud, Yves; Grillon, Gerard; Poncy, Jean-Luc; Masse, Roland

1992-06-01

Selenium 79 ( 79 Se) and technetium ( 99 Tc), beta emitters, components of nuclear wastes, may increase the dose equivalent to members of the public. Data used by ICRP show that there is relatively little information on Te and Se biokinetics at different physiologic stages. Retention was almost equivalent for young, male adult and pregnant rat. Selenium was concentrated in the testis, the kidneys, the liver and the spleen as technetium was in the skin, the thyroid and the kidneys. The biological half-time for Se and Te was respectively 20 and 41 days for pregnant rats, 33 and 15 days for young rats. Placental transfer per one fetus was 0.56% of the initial activity for Te and 1.27% for Se. These data point out the eventually high doses delivered to the skin for Te and to the testis for Se. They may be taken into consideration in estimating risk by humans at different stages of life [fr

Environmental fate and distribution of technetium-99 in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Tucker, C.S.; Walton, B.T.

1986-01-01

The uptake of 99 Tc by trees intercepting contaminated groundwater from a radioactive waste storage site was measured to identify the major 99 Tc pools within the woodland ecosystem and to assess the relative mobility of 99 Tc in the existing element cycle. The highest average 99 Tc concentrations in vegetation were found in herbaceous plants. Tree wood was the major above-ground pool for 99 Tc because of the high concentrations in wood as well as the large amount of wood relative to other biomass at the site. Technetium was not easily leached from the trees by rainfall and was not readily extractable from forest floor leaf litter by water. The relative importance of return pathways for 99 Tc to the forest floor was leaf fall > stemflow > throughfall, indicating that 99 Tc was conserved by the trees. Snails and millipedes from the leaf litter layer concentrated technetium 20- and 16-fold, respectively, above levels found in the soil. Pertechnetate was rendered less bioavailable after ingestion by a leaf litter macroinvertebrate (Porcellio sp.) common to the study site. (author)

Technetium electrodeposition from aqueous formate solutions: electrolysis kinetics and material balance study

International Nuclear Information System (INIS)

Maslennikov, A.; Peretroukhine, V.

1998-01-01

The kinetics of the Tc electrodeposition and the material balance of potentiostatic electrolysis of formate buffer solutions (pH = 1.79-8.5) containing 5*10 -4 - 1*10 -2 M Tc(VII) at graphite cathode has been studied. The deposition of Tc from the solution was found to become possible at E x *y H 2 O (x ≤ 2, 1.5 cath. ) towards more negative values and the augmentation of the electrolyte surface/volume ratio (S/V) were found to increase the yield of the electrolysis and the rate of the electrodeposition process. A maximum technetium recovery of 92-95% has been observed in the electrolysis of neutral HCOONa solutions (pH = 6.0-7.5, μ = 1.0) containing up to 5*10 -1 M Tc(VII) at potentials of the graphite cathode E 2 . A starting Tc concentration in the solution of [Tc(VII)] > 5 *10 -1 M and the presence of more than 0.05 M NO 3 - in the electrolyte were found to suppress the recovery of technetium from the solution. (orig.)

Optical power limiting and transmitting properties of cadmium iodide single crystals: Temperature dependence

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)] [Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)] [Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2009-09-14

Optical limiting properties of the single crystals of cadmium iodide are investigated using ns laser pulses. It is found that the transmissions in the crystals increase with increasing temperature. However, they limit the transmissions at high input powers. The limiting power is found to be higher at higher temperature. From the measured transmission data, the photon absorption coefficients are estimated. The temperature dependence of the coefficients shows a decrease in magnitude with increasing temperature. This might be due to the temperature-dependent bandgap shift of the material. The results demonstrate that the cadmium iodide single crystals are promising materials for applications in optical power limiting devices.

Optical power limiting and transmitting properties of cadmium iodide single crystals: Temperature dependence

International Nuclear Information System (INIS)

Miah, M. Idrish

2009-01-01

Optical limiting properties of the single crystals of cadmium iodide are investigated using ns laser pulses. It is found that the transmissions in the crystals increase with increasing temperature. However, they limit the transmissions at high input powers. The limiting power is found to be higher at higher temperature. From the measured transmission data, the photon absorption coefficients are estimated. The temperature dependence of the coefficients shows a decrease in magnitude with increasing temperature. This might be due to the temperature-dependent bandgap shift of the material. The results demonstrate that the cadmium iodide single crystals are promising materials for applications in optical power limiting devices.

Methyl iodide retention on charcoal sorbents at parts-per-million concentrations

International Nuclear Information System (INIS)

Wood, G.O.; Vogt, G.J.; Kasunic, C.A.

1978-01-01

Breakthrough curves for charcoal beds challenged by air containing parts-per-million methyl iodide ( 127 I) vapor concentrations were obtained and analyzed. A goal of this research is to determine if sorbent tests at relatively high vapor concentrations give data that can be extrapolated many orders of magnitude to the region of interest for radioiodine retention and removal. Another objective is to identify and characterize parameters that are critical to the performance of a charcoal bed in a respirator cartridge application. Towards these ends, a sorbent test system was built that allows experimental variations of the parameters of challenge vapor concentration, volumetric flow rate, bed depth, bed diameter, and relative humidity. Methyl iodide breakthrough was measured at a limit of 0.002 ppM using a gas chromatograph equipped with a linearized electron capture detector. Several models that have been proposed to describe breakthrough curves were tested against experimental data. A variety of charcoals used or proposed for use in radioiodine air filtration systems have been tested against 25.7 ppM methyl iodide to obtain these parameters and protection (decomtamination) factors. Effects of challenge concentration, relative humidity, and bed diameter were also investigated. Significant challenge concentration dependence was measured (more efficiency at lower concentration) for two types of charcoals. Increased relative humidity greatly decreased breakthrough times for a given protection factor. Increased bed diameter greatly increased breakthrough times for a given protection factor. Implications of these effects for a test method are discussed

Method for ion exchange purification of sodium iodide solution from heavy metals and potassium microimpurities

International Nuclear Information System (INIS)

Smirnov, G.I.; Kachur, N.Ya.; Kostromina, O.N.; Ogorodnikova, A.A.; Khajnakov, S.A.

1990-01-01

A method of deep ion exchange purification of sodium iodide solution from heavy metals (iron, nickel, copper, lead) and potassium microimpurities is developed. The method includes multiple sorption of microimpurities on titanium phosphate with their subsequent desorption by sorbent processing with a solution with a solution of 3-6 N nitric acid, first, and then with a neutral solution of 2 % sodium thiosulfate. The given method permits to increase the purification degree of sodium iodide solution by 25-30 %. 2 tabs

Silver-Assisted Synthesis of Gold Nanorods: the Relation between Silver Additive and Iodide Impurities.

Science.gov (United States)

Jessl, Sarah; Tebbe, Moritz; Guerrini, Luca; Fery, Andreas; Alvarez-Puebla, Ramon A; Pazos-Perez, Nicolas

2018-04-17

Seed-mediated methods employing cetyltrimethylammonium bromide (CTAB) as a surfactant, and silver salts as additives, are the most common synthetic strategies for high-yield productions of quality Au nanorods. However, the mechanism of these reactions is not yet fully understood and, importantly, significant lab-to-lab reproducibility issues still affect these protocols. In this study, the direct correlation between the hidden content of iodide impurities in CTAB reagents, which can drastically differ from different suppliers or batches, and the optimal concentration of silver required to maximize the nanorods yield is demonstrated. As a result, high-quality nanorods are obtained at different iodide contents. These results are interpreted based on the different concentrations of CTAB and cetyltrimethylammonium iodide (CTAI) complexes with Ag + and Au + metal ions in the growth solution, and their different binding affinity and reduction potential on distinct crystallographic planes. Notably, the exhaustive conversion of CTAI-Au + to CTAI-Ag + appears to be the key condition for maximizing the nanorod yield. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Anion retention in soil: Possible application to reduce migration of buried technetium and iodine

International Nuclear Information System (INIS)

Gu, B.; Schulz, R.K.

1991-10-01

This report summarizes a literature review of our present knowledge of the anion exchange properties of a number of soils and minerals, which may potentially be used as anion exchangers to retard migration of such anions as iodide (I - ), iodate (IO 3 - ) and pertechnetate (TcO 4 - ) away from disposal site. The amorphous clays allophane and imogolite, are found to be among the most important soil components capable of developing appreciable amounts of positive charge for anion exchange even at about neutral pH. Decreases in the SiO 2 /Al 2 O 3 ratio and soil pH result in an increase in soil AEC. Allophane and imogolite rich soils have an AEC ranging from 1 to 18 meq/100g at pH about 6. Highly weathered soils dominated by Fe and Al oxides and kaolinite may develop a significant amount of AEC as soil pH falls. The retention of iodine (I) and technetium (T c ), by soils is associated with both soil organic matter, and Fe and Al oxides, whereas sorption on layer silicate minerals in negligible. Fe and Al oxides become more important in the retention of anionic I - , IO 3 - , and TcO 4 - as pH falls, since more positive charge is developed on the oxide surfaces. Although few studies, if any, have been conducted on I and T c sorption by soil allophane and imogolite, it is estimated that a surface plough soil (2 million pounds soil per acre) with 5 meq/100g AEC, as is commonly found in andisols, shall retain approximately 5900 kg I and 4500 kg T c . It is conceivable that an anion exchanger such as an andisol could be used to modify the near field environment of a radioactive waste disposal facility. This whole disposal system would then offer similar migration resistance to anions as is normally afforded to cations by usual and normal soils. 93 refs., 10 figs., 7 tabs

Anion retention in soil: Possible application to reduce migration of buried technetium and iodine

Energy Technology Data Exchange (ETDEWEB)

Gu, B.; Schulz, R.K. (California Univ., Berkeley, CA (United States). Dept. of Soil Science)

1991-10-01

This report summarizes a literature review of our present knowledge of the anion exchange properties of a number of soils and minerals, which may potentially be used as anion exchangers to retard migration of such anions as iodide (I{sup {minus}}), iodate (IO{sub 3}{sup {minus}}) and pertechnetate (TcO{sub 4}{sup {minus}}) away from disposal site. The amorphous clays allophane and imogolite, are found to be among the most important soil components capable of developing appreciable amounts of positive charge for anion exchange even at about neutral pH. Decreases in the SiO{sub 2}/Al{sub 2}O{sub 3} ratio and soil pH result in an increase in soil AEC. Allophane and imogolite rich soils have an AEC ranging from 1 to 18 meq/100g at pH about 6. Highly weathered soils dominated by Fe and Al oxides and kaolinite may develop a significant amount of AEC as soil pH falls. The retention of iodine (I) and technetium ({Tc}), by soils is associated with both soil organic matter, and Fe and Al oxides, whereas sorption on layer silicate minerals in negligible. Fe and Al oxides become more important in the retention of anionic I{sup {minus}}, IO{sub 3}{sup {minus}}, and TcO{sub 4}{sup {minus}} as pH falls, since more positive charge is developed on the oxide surfaces. Although few studies, if any, have been conducted on I and {Tc} sorption by soil allophane and imogolite, it is estimated that a surface plough soil (2 million pounds soil per acre) with 5 meq/100g AEC, as is commonly found in andisols, shall retain approximately 5900 kg I and 4500 kg {Tc}. It is conceivable that an anion exchanger such as an andisol could be used to modify the near field environment of a radioactive waste disposal facility. This whole disposal system would then offer similar migration resistance to anions as is normally afforded to cations by usual and normal soils. 93 refs., 10 figs., 7 tabs.

Silver iodide reduction in aqueous solution: application to iodine enhanced separation during spent nuclear fuels reprocessing

International Nuclear Information System (INIS)

Badie, Jerome

2002-01-01

Silver iodide is a key-compound in nuclear chemistry either in accidental conditions or during the reprocessing of spent nuclear fuel. In that case, the major part of iodine is released in molecular form into the gaseous phase at the time of dissolution in nitric acid. In French reprocessing plants, iodine is trapped in the dissolver off-gas treatment unit by two successive steps: the first consists in absorption by scrubbing with a caustic soda solution and in the second, residual iodine is removed from the gaseous stream before the stack by chemisorption on mineral porous traps made up of beds of amorphous silica or alumina porous balls impregnated with silver nitrate. Reactions of iodine species with the impregnant are assumed to lead to silver iodide and silver iodate. Enhanced separation policy would make necessary to recover iodine from the filters by silver iodide dissolution during a reducing treatment. After a brief silver-iodine chemical bibliographic review, the possible reagents listed in the literature were studied. The choice has been made to use ascorbic acid and hydroxylamine. An experimental work on silver iodide reduction by this two compounds allowed us to determinate reaction products, stoichiometry and kinetics parameters. Finally, the process has been initiated on stable iodine loaded filters samples. (author) [fr

Towards a biochemical and structural characterisation of the sodium-iodide sym-porter (Nis)

International Nuclear Information System (INIS)

Darrouzet, E.; Marcellin, D.; Huc, S.; Quemeneur, E.; Pourcher, T.

2006-01-01

Iodide is essential for thyroid hormone biosynthesis in mammals, and therefore for the control of cell metabolism and the development of the central nervous system in the foetus and newborns, but is relatively scarce element in the environment. To ensure its accumulation, the thyroid gland has evolved a remarkably efficient system, the sodium-iodide sym-porter (NIS), that was first characterized at the molecular level 10 years ago (1). NIS is an intrinsic protein mainly located in the basolateral membrane of thyroid follicular cells where it actively transports iodide ions using the sodium gradient as a driving force (2,3). In addition, this transporter has been found in lactating mammary gland, stomach, and salivary glands, and its mRNA was detected in brain, ovaries, testis. To date, the physiological role of NIS in these organs is not yet identified (3,4).The capacity of NIS to mediate the accumulation of radioactive iodide has been exploited for many years in the diagnosis of thyroid cancer as well as for the detection and radiotherapy of derived metastases. Moreover, the presence of NIS in some breast tumours and the possibility to express it by targeted gene therapy in tumour cells where it is not naturally present could also widen its medical application (4-7). In case of accidental contamination, NIS would also be responsible for accumulation of radioisotopes in the thyroid and for their transfer to the milk and the newborn, eventually causing thyroid cancers. This has motivated our research program in the perspective of designing novel specific therapeutics. During the last decade, the gene encoding the thyroid NIS has been identified and sequenced in various species including rat, mouse and human (1, 8). It was also demonstrated that the protein expression and activity are highly regulated both at the transcriptional and post-translational levels (3). A preliminary topological mode could be drawn from the protein sequence. It proposes a general

1-(3-Iodopropyl-4-methylquinolin-1-ium Iodide

Directory of Open Access Journals (Sweden)

Todor Deligeorgiev

2015-11-01

Full Text Available A solvent-free “one-pot” synthetic approach to 1-(3-iodopropyl-4-methylquinolin-1-ium iodide is reported in the present work. The title compound is derived from N-alkylation of 4-methylquinoline with 1,3-diiodopropane proceeded at room temperature. The target quinolinium salt is obtained in a highly pure form. It’s structure was evaluated by 1H-NMR, 13C-NMR, and DEPT135 spectra.

Expedient Method for Samarium(II) Iodide Preparation Utilizing a Flow Approach

Czech Academy of Sciences Publication Activity Database

Voltrová, Svatava; Šrogl, Jiří

2013-01-01

Roč. 24, č. 3 (2013), s. 394-396 ISSN 0936-5214 R&D Projects: GA MŠk LH12013 Institutional support: RVO:61388963 Keywords : flow * samarium * iodide * reduction Subject RIV: CC - Organic Chemistry Impact factor: 2.463, year: 2013

Technetium labelled plasminogen activator - a potential reagent for thrombus detection

Energy Technology Data Exchange (ETDEWEB)

Paulsma-De Waal, J.H.; Boer, A.C. de; Cox, P.H.; Pillay, M.; Stassen, J.H.; Collen, D.

1987-12-01

The preparation of a technetium labelled plasminogen activator complex using a solid phase labelling technique is described. The labelled complex showed no significant loss of fibrinolytic activity in vitro and showed in vivo a rapid uptake in thrombi in an animal model and in human volunteer patients with known thrombi when injected into a vein draining to the thrombotic region. Systemic injection showed no uptake in the thrombi probably due to rapid sequestration of the complex by the liver.

Evaluation of perturbations in serum thyroid hormones during human pregnancy due to dietary iodide and perchlorate exposure using a biologically based dose-response model.

Science.gov (United States)

Lumen, Annie; Mattie, David R; Fisher, Jeffrey W

2013-06-01

A biologically based dose-response model (BBDR) for the hypothalamic pituitary thyroid (HPT) axis was developed in the near-term pregnant mother and fetus. This model was calibrated to predict serum levels of iodide, total thyroxine (T4), free thyroxine (fT4), and total triiodothyronine (T3) in the mother and fetus for a range of dietary iodide intake. The model was extended to describe perchlorate, an environmental and food contaminant, that competes with the sodium iodide symporter protein for thyroidal uptake of iodide. Using this mode-of-action framework, simulations were performed to determine the daily ingestion rates of perchlorate that would be associated with hypothyroxinemia or onset of hypothyroidism for varying iodide intake. Model simulations suggested that a maternal iodide intake of 75 to 250 µg/day and an environmentally relevant exposure of perchlorate (~0.1 µg/kg/day) did not result in hypothyroxinemia or hypothyroidism. For a daily iodide-sufficient intake of 200 µg/day, the dose of perchlorate required to reduce maternal fT4 levels to a hypothyroxinemic state was estimated at 32.2 µg/kg/day. As iodide intake was lowered to 75 µg/day, the model simulated daily perchlorate dose required to cause hypothyroxinemia was reduced by eightfold. Similarly, the perchlorate intake rates associated with the onset of subclinical hypothyroidism ranged from 54.8 to 21.5 µg/kg/day for daily iodide intake of 250-75 µg/day. This BBDR-HPT axis model for pregnancy provides an example of a novel public health assessment tool that may be expanded to address other endocrine-active chemicals found in food and the environment.

Voltammetric assay of extremely low technetium concentrations following enrichment at the HMDE after reaction with Thiocyanate

International Nuclear Information System (INIS)

Friedrich, M.; Ruf, H.

1984-12-01

It is known that in sulfuric acid solution pertechnetate is reduced by thiocyanate to form thiocyanate complexes. After this reaction the technetium acquires the capability of being adsorbed at the hanging mercury drop electrode (HMDE) provided that a potential of -0,40 V (vs. Ag/AgCl) has been applied to the electrode. If, by application of the differential pulse voltammetry after the phase of deposition the potential at the electrode is scanned cathodically, traces of technetium can be determined very sensitively by evaluation of the peak current recorded at minus 1,27 V (Ag/AgCl). The effect is still being enhanced by the presence of not interfering small perrhenate amounts. The reproducibility of the measured values is excellent. (orig.) [de

Mass spectral analysis of cationic and neutral technetium complexes

International Nuclear Information System (INIS)

Unger, S.E.; McCormick, T.J.; Nunn, A.N.; Treher, E.N.

1986-01-01

Cationic and neutral technetium compounds have been characterized by mass spectrometry using a variety of ionization methods. These compounds include octahedral cationic complexes containing phosphorous and arsenic ligands such as DIPHOS and DIARS and neutral complexes containing PnAO and dimethylglyoxime, DMG, or cyclohexanedione dioxime, CDO, ligands. Boronate esters incorporating methyl and butyl derivatives of the DMG and CDO dioximes represent a new class of seven-coordinate Tc radiopharmaceuticals whose characterization by mass spectrometry has not previously been described. These complexes show promise as myocardial imaging agents. (author)

Role of endoplasmic reticulum stress-induced apoptosis in rat thyroid toxicity caused by excess fluoride and/or iodide.

Science.gov (United States)

Liu, Hongliang; Hou, Changchun; Zeng, Qiang; Zhao, Liang; Cui, Yushan; Yu, Linyu; Wang, Lingzhi; Zhao, Yang; Nie, Junyan; Zhang, Bin; Wang, Aiguo

2016-09-01

Excess fluoride and iodide coexist in drinking water in many regions, but few studies have investigated the single or interactive effects on thyroid in vivo. In our study, Wistar rats were exposed to excess fluoride and/or iodide through drinking water for 2 or 8 months. The structure and function of the thyroid, cells apoptosis and the expression of inositol-requiring enzyme 1 (IRE1) pathway-related factors were analyzed. Results demonstrated that excess fluoride and/or iodide could change thyroid follicular morphology and alter thyroid hormone levels in rats. After 8 months treatment, both single and co-exposure of the two microelements could raise the thyroid cells apoptosis. However, the expressions of IRE1-related factors were only increased in fluoride-alone and the combined groups. In conclusion, thyroid structure and thyroid function were both affected by excess fluoride and/or iodide. IRE1-induced apoptosis were involved in this cytotoxic process caused by fluoride or the combination of two microelements. Copyright © 2016 Elsevier B.V. All rights reserved.

New colorimetric and fluorometric sensing strategy based on the anisotropic growth of histidine-mediated synthesis of gold nanoclusters for iodide-specific detection.

Science.gov (United States)

Wang, Yifeng; Zhu, Haiyan; Yang, Xiaoming; Dou, Yao; Liu, Zhongde

2013-04-07

Iodide, as a biologically important anion, it remains a worthwhile yet challenging undertaking to find a sensitive and specific approach to provide a technically simple iodide detection. In this article, it was found that no other ions than iodide-induced anisotropic growth of gold nanocrystals (AuNCs) originated from a small molecule, histidine-mediated synthesis of AuNCs, were observed. Simultaneously, it is accompanied by the fluorescence quenching of AuNCs and the naked-eye visible color change. Therefore, a new colorimetric and fluorometric sensing strategy was developed for the iodide-specific detection. Compared with currently reported methods, the present one displays the advantages of the visual detection and simplicity. The quenched fluorescence and enhanced surface plasmon resonance absorbance were found to be proportional to the iodide concentration over the range of 0.8-60 and 1.2-50 μM with a detection limit (3σ) of 118 nM and 215 nM, respectively.

Investigation of space-occupying lesions in the liver with technetium-99m tin colloid and indium-113m-chloride

International Nuclear Information System (INIS)

Nelson, M.J.; Klopper, J.F.

1985-01-01

Liver scanning with radiocolloids is an important method to determine the presence, the position and the size of space-occupying lesions in the liver. Unfortunately, this information is nonspecific and it is not possible to distinguish between tumours, abscesses or cysts. Thirty-six patients in whom a definite diagnosis of hepatoma, amoebic liver abscess or echinococcus cyst had been made were examined with technetium-99m tin colloid and indium-113m chloride. The amoebic liver abscesses were avascular, showed a hyperaemic area surrounding the abscess and appeared smaller on the indium than on the technetium scan. The hepatomas showed greater vascularity and absence of the hyperaemic area. Cysts were avascular, did not show a hyperaemic rim and the size was equal on both scans. The experience of the observers had an influence on the accuracy of interpretation of the scans; experienced observers made a correct diagnosis in 73% of cases. It is suggested that simultaneous technetium-99m tin colloid and indium 113m-chloride scans provide additional specificity in the differential diagnosis between hepatoma, amoebic liver abscess and echinococcus cysts

Investigation of space-occupying lesions in the liver with technetium-99m tin colloid and indium-113m-chloride

Energy Technology Data Exchange (ETDEWEB)

Nelson, M.J. (Provincial Hospital, Port Elizabeth (South Africa). Dept. of Nuclear Medicine); Klopper, J.F. (Stellenbosch Univ. (South Africa). Dept. of Nuclear Medicine)

1985-01-26

Liver scanning with radiocolloids is an important method to determine the presence, the position and the size of space-occupying lesions in the liver. Unfortunately, this information is nonspecific and it is not possible to distinguish between tumours, abscesses or cysts. Thirty-six patients in whom a definite diagnosis of hepatoma, amoebic liver abscess or echinococcus cyst had been made were examined with technetium-99m tin colloid and indium-113m chloride. The amoebic liver abscesses were avascular, showed a hyperaemic area surrounding the abscess and appeared smaller on the indium than on the technetium scan. The hepatomas showed greater vascularity and absence of the hyperaemic area. Cysts were avascular, did not show a hyperaemic rim and the size was equal on both scans. The experience of the observers had an influence on the accuracy of interpretation of the scans; experienced observers made a correct diagnosis in 73% of cases. It is suggested that simultaneous technetium-99m tin colloid and indium 113m-chloride scans provide additional specificity in the differential diagnosis between hepatoma, amoebic liver abscess and echinococcus cysts.

Electrokinetic properties and conductance relaxation of polystyrene and silver iodide plugs

NARCIS (Netherlands)

Hoven, van den J.J.

1984-01-01

This thesis describes an experimental study on the electrokinetic and electrical properties of concentrated polystyrene and silver iodide dispersions. The purpose of the study is to obtain information on the structure of the electrical double layer at the solid-liquid interface. Special

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)

Feasibility Study for the Reduction of Perchlorate, Iodide, and Other Aqueous Anions

National Research Council Canada - National Science Library

Clewell, Rebecca A; Tsui, David T; Mattie, David R

1999-01-01

Cyclic Voltammetry (CV) was used as a technique to determine the feasibility of the use of a coulometric detector in the determination of perchlorate, iodide, and various other anions commonly found in drinking water...

Iodide Residues in Milk Vary between Iodine-Based Teat Disinfectants

NARCIS (Netherlands)

French, Elizabeth A; Mukai, Motoko; Zurakowski, Michael; Rauch, Bradley; Gioia, Gloria; Hillebrandt, Joseph R; Henderson, Mark; Schukken, Ynte H; Hemling, Thomas C

Majority of iodine found in dairy milk comes from the diet and teat disinfection products used during milking process. The objective of this study was to evaluate the effects of 4 iodine-based teat dips on milk iodide concentrations varying in iodine level (0.25% vs. 0.5%, w/w), normal low viscosity

PI3K activation is associated with intracellular sodium/iodide symporter protein expression in breast cancer

International Nuclear Information System (INIS)

Knostman, Katherine AB; McCubrey, James A; Morrison, Carl D; Zhang, Zhaoxia; Capen, Charles C; Jhiang, Sissy M

2007-01-01

The sodium/iodide symporter (NIS) is a membrane glycoprotein mediating active iodide uptake in the thyroid gland and is the molecular basis for radioiodide imaging and therapeutic ablation of thyroid carcinomas. NIS is expressed in the lactating mammary gland and in many human breast tumors, raising interest in similar use for diagnosis and treatment. However, few human breast tumors have clinically evident iodide uptake ability. We previously identified PI3K signaling as important in NIS upregulation in transgenic mouse models of breast cancer, and the PI3K pathway is commonly activated in human breast cancer. NIS expression, subcellular localization, and function were analyzed in MCF-7 human breast cancer cells and MCF-7 cells stably or transiently expressing PI3K p110alpha subunit using Western blot of whole cell lysate, cell surface biotinylation Western blot and immunofluorescence, and radioiodide uptake assay, respectively. NIS localization was determined in a human breast cancer tissue microarray using immunohistochemical staining (IHC) and was correlated with pre-existing pAkt IHC data. Statistical analysis consisted of Student's t-test (in vitro studies) or Fisher's Exact Test (in vivo correlational studies). In this study, we demonstrate that PI3K activation in MCF-7 human mammary carcinoma cells leads to expression of underglycosylated NIS lacking cell surface trafficking necessary for iodide uptake ability. PI3K activation also appears to interfere with cell surface trafficking of exogenous NIS as well as all-trans retinoic acid-induced endogenous NIS. A correlation between NIS expression and upregulation of PI3K signaling was found in a human breast cancer tissue microarray. Thus, the PI3K pathway likely plays a major role in the discordance between NIS expression and iodide uptake in breast cancer patients. Further study is warranted to realize the application of NIS-mediated radioiodide ablation in breast cancer

Non-radioactive determination of the penetration of methyl iodide through impregnated charcoals during dosing and purging

International Nuclear Information System (INIS)

Romans, J.B.; Deitz, V.R.

1979-01-01

A laboratory procedure is described using methyl iodide-127 which had the same linear flow of air (12.2 m/min) and contact time (0.25 sec.) as the RDT M16 Test Procedure. Only one-fourth of the charcoal was used (in a bed 2.54 cm diameter and 5.08 cm high) and the required dose of methyl iodide-127 was reduced from 5.25 to 1.31 mg. The inlet concentrations were determined with a gas chromatograph and the effluent concentrations with a modified microcoulombmeter. Two calibration procedures were used: (1) known vapor pressure of iodine crystals, and (2) quantitative pyrolysis of the methyl iodide-127 delivered from certified permeation tubes. Five charcoals and three impregnations were used in this study. Typical behaviors are given in 90% RH air with the charcoals either prehumidified for 16 hours at 90% RH or without the prehumidification. The breakthrough curves, concentration versus time, rose very slowly for the first 120 minutes and then more rapidly for an additional time. The lack of a dependence on the magnitude of the dose is compatible with a catalytic trapping mechanism. In the case of KI/sub x/ impregnations, there was excess emission of iodine during purging over that introduced as methyl iodide-127 which must have originated in the reservoir of iodine contained in the impregnation

Polymeric membrane sensors based on Cd(II) Schiff base complexes for selective iodide determination in environmental and medicinal samples.

Science.gov (United States)

Singh, Ashok Kumar; Mehtab, Sameena

2008-01-15

The two cadmium chelates of schiff bases, N,N'-bis(salicylidene)-1,4-diaminobutane, (Cd-S(1)) and N,N'-bis(salicylidene)-3,4-diaminotoluene (Cd-S(2)), have been synthesized and explored as ionophores for preparing PVC-based membrane sensors selective to iodide(I) ion. Potentiometric investigations indicate high affinity of these receptors for iodide ion. Polyvinyl chloride (PVC)-based membranes of Cd-S(1) and Cd-S(2) using as hexadecyltrimethylammonium bromide (HTAB) cation discriminator and o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), acetophenone (AP) and tributylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as iodide-selective sensors. The best performance was shown by the membrane of composition (w/w) of (Cd-S(1)) (7%):PVC (31%):DBP (60%):HTAB (2%). The sensor works well over a wide concentration range 5.3x10(-7) to 1.0x10(-2)M with Nernstian compliance (59.2mVdecade(-1) of activity) within pH range 2.5-9.0 with a response time of 11s and showed good selectivity for iodide ion over a number of anions. The sensor exhibits adequate life (3 months) with good reproducibility (S.D.+/-0.24mV) and could be used successfully for the determination of iodide content in environmental water samples and mouth wash samples.

Preliminary Design of Molecular Sieve for Removing Organic Iodide in Containment Filtered Venting System

Energy Technology Data Exchange (ETDEWEB)

Park, Tong Kyu; Shin, So Eun; Lee, Byung Chul [Heungdeok IT Valley Bldg., Yongin (Korea, Republic of); Kim, Hong Hyun; Lee, Kyung Jun [Gemvax and KAEL Inc., Daejeon (Korea, Republic of)

2014-05-15

In this paper, to increase the DF for gaseous iodine species, especially organic iodide, molecular sieve filled by silver exchanged zeolites is proposed and designed preliminarily. Its aerodynamic analysis is also performed and presented. In order to increase the DF for gaseous organic iodide, deep-bed type molecular sieve was proposed and designed preliminarily. Total 1,620kg of silver exchanged zeolites were filled evenly in 10 beds of the molecular sieve. The safety factor in the case of 20m{sup 3}/s will be smaller than the counterpart of the standard case (6m{sup 3}/s). However, if the adsorption capacity of the zeolites is larger than 3.09mg/g when the residence time is 0.09 second, the designed molecular sieve can be used at 20m3/s of volumetric flow rate. The removal efficiency for organic iodide should be considered as well as economical aspects in the design of molecular sieve. In the event of nuclear power plant (NPP) severe accident, the nuclear reactor containment might suffer damage resulting from overpressure caused by decay heat. In order to prevent this containment damage, containment venting has been considered as one of effective methods. However, since vented gases contain radioactive fission products, they should be filtered to be released to environment. Generally, containment filtered venting system (CFVS) is installed on NPP to achieve this aim. Even though great amount of efforts have been devoted to developing the CFVS using various filtering methods, the decontaminant factor (DF) for radioactive gaseous iodide is still unsatisfactory while DFs for radioactive aerosols and elemental iodine are very high.

Selective gettering of hydrogen in high pressure metal iodide lamps

International Nuclear Information System (INIS)

Kuus, G.

1976-01-01

One of the main problems in the manufacture of high pressure gas discharge lamps is the elimination of gaseous impurities from their arc tubes. Long degassing processes of all the lamp components are necessary in order to produce lamps with a low ignition voltage and good maintenance of the radiation properties. The investigation described deals with a selective getter place in the arc tube which can replace the long degassing process. The getter consists of a piece of yttrium encapsulated in thin tantalum foil. By this way it is possible to use the gettering action of tantalum and yttrium without having reaction between the metal iodide of the arc tube and yttrium. Yttrium is used because this metal can adsorb a large quantity of hydrogen even at a temperature of 1000 0 C. Hydrogen forms the main gaseous impurity in the high pressure metal iodide lamp. For this reason the adsorption properties like adsorption rate and capacity of the tantalum--yttrium getter for hydrogen are examined, and the results obtained from lamp experiments are given

Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

Science.gov (United States)

Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

2014-10-21

Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

Iodide Sorption to Clays and the Relationship to Surface Charge and Clay Texture - 12356

Energy Technology Data Exchange (ETDEWEB)

Miller, Andrew; Kruichiak, Jessica; Tellez, Hernesto; Wang, Yifeng [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

2012-07-01

Iodine is assumed to behave conservatively in clay barriers around nuclear waste repositories and in natural sediments. Batch experiments tend to show little to no sorption, while in column experiments iodine is often retarded relative to tritiated water. Current surface complexation theory cannot account for negatively charged ion sorption to a negatively charged clay particle. Surface protonation and iodide sorption to clay minerals were examined using surface titrations and batch sorption experiments with a suite of clay minerals. Surface titrations were completed spanning a range of both pH values and ionic strengths. For reference, similar titrations were performed on pure forms of an Al-O powder. The titration curves were deconvoluted to attain the pKa distribution for each material at each ionic strength. The pKa distribution for the Al-O shows two distinct peaks at 4.8 and 7.5, which are invariant with ionic strength. The pKa distribution of clays was highly variable between the different minerals and as a function of ionic strength. Iodide sorption experiments were completed at high solid:solution ratios to exacerbate sorption properties. Palygorskite and kaolinite had the highest amount of iodide sorption and montmorillonite had the least. (authors)

Technetium(V)-nitrido complexes of dithiocarbazic acid derivatives. Reactivity of [Tc≡N]2+ core towards Schiff bases derived from S-methyl dithiocarbazate. Crystal structures of [S-methyl 3-(2-hydroxyphenyl-methylene) dithiocarbazato]intrido(triphenylphosphine)technetium(V) and bis(S-methyl 3-isopropylidenedithiocarbazato)nitridotechnetium(V)

International Nuclear Information System (INIS)

Marchi, A.; Duatti, A.; Rossi, R.; Magon, L.; Bertolasi, V.; Ferretti, V.; Gilli, G.; Pasqualini, R.

1988-01-01

As a potential alternative approach to lipophilic square-pyramidal technetium complexes, we investigate here the synthesis of new Tcsup(V) complexes, containing the [Tc''ident to''N] 2+ core, with bi- and tri-dentate Schiff bases derived from S-methyl dithiocarbazate, NH 2 NHC(=S)SCH 3 . Square-pyramidal complexes having an apical Tcsup(V) ≡ N group, with bis(quinoline-8-thiolato), [TcN(C 9 H 6 NS) 2 ], and bis(diethyldithiocarbamate), [TcN(S 2 CNEt 2 ) 2 ], have been reported. In this paper, we report the synthesis and characterization of a series of technetium(V)-nitrido complexes with the ligands illustrated, obtained by reduction of the technetium(VI) complex [TcNCl 4 ] - or by ligand substitution of the Tcsup(V) complex [TcNCl 2 (PPh 3 ) 2 ]. We discuss also the crystal structures of the complexes [TcNL 1 (PPh 3 )] [H 2 L 1 = S-methyl 3-(2-hydroxy-phenylmethylene)dithiocarbazate] and [TcN(L 12 ) 2 ] (HL 12 S-methyl 3-isopropylidenedithiocarbazate. (author)

PRELIMINARY ASSESSMENT OF THE LOW-TEMPERATURE WASTE FORM TECHNOLOGY COUPLED WITH TECHNETIUM REMOVAL

Energy Technology Data Exchange (ETDEWEB)

Fox, K.

2014-05-13

The U.S. Department of Energy Office of Environmental Management (EM) is engaging the national laboratories to provide the scientific and technological rigor to support EM program and project planning, technology development and deployment, project execution, and assessment of program outcomes. As an early demonstration of this new responsibility, Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) have been chartered to implement a science and technology program addressing low-temperature waste forms for immobilization of DOE aqueous waste streams, including technetium removal as an implementing technology. As a first step, the laboratories examined the technical risks and uncertainties associated with the Cast Stone waste immobilization projects at Hanford. Science and technology needs were identified for work associated with 1) conducting performance assessments and risk assessments of waste form and disposal system performance, and 2) technetium chemistry in tank wastes and separations of technetium from waste processing streams. Technical approaches to address the science and technology needs were identified and an initial sequencing priority was suggested. The following table summarizes the most significant science and technology needs and associated approaches to address those needs. These approaches and priorities will be further refined and developed as strong integrated teams of researchers from national laboratories, contractors, industry, and academia are brought together to provide the best science and technology solutions. Implementation of a science and technology program that addresses these needs by pursuing the identified approaches will have immediate benefits to DOE in reducing risks and uncertainties associated with near-term decisions regarding supplemental immobilization at Hanford. Longer term, the work has the potential for cost savings and for providing a strong technical foundation for future

Organic iodide capture using a zeolite dry filtration

International Nuclear Information System (INIS)

Park, Sanggil; Sung, Joonyoung; Kim, Gi-ppeum; Lee, Jaeyoung

2017-01-01

An organic iodide, especially, methyl iodide (CH 3 I) would generated non-negligibly from a severe accident in a nuclear power plant. This CH 3 I will be dangerous for human when it was inhaled, it is highly toxic and causes a serious nerve disorder. Even it is a major contributor to a thyroid cancer. In order to prevent its environmental release, it is required to decontaminate using a filtration system. For the removal of CH 3 I from the release gases, wet-type is not ideal due to a high re-volatile characteristics of CH 3 I. It may become volatile after dissolving in a pool and forms CH 3 I again at the surface of water pool. Therefore, a dry-filtration should be installed to remove the CH 3 I. In this study, we preliminary investigate the characteristics of zeolite filtration methods for the removal of CH 3 I. We used both silver ion exchanged ZSM-5-zeolite (Ag+-ZSM-5) to study the effect of silver ion for the removal of iodine from CH 3 I. In summary, the CH 3 I capture tests using a silver ion exchanged zeolite was conducted in the coupled TGAGC test set-up. The mass change of the sample and concentration of CH 3 I were measured. The samples were investigated by the SEM/EDS to see its surface characteristics.

Labeling of thymine with 99m technetium: a suggestion of a chemical model

International Nuclear Information System (INIS)

Gutfilen, Bianca; Silva, Claudia Ribeiro da; Bernardo Filho, Mario; Ribeiro, Barbara Luzia Almeida; Mattos, Maura Ferreira

1996-01-01

Successful targeting of diagnose but also to stage cancer. It has been shown that certain tumor cells are permeable to low level of exogenous adenosine-diphosphate and adenosine-triphosphate nucleotides, that are incorporated into intracellular pools. We present the labeling of a nucleotide precursor, a base, thymine technetium-99m ( 99m Tc). (author)

Technetium(I) complexes Tc(CO)3BrL2 (L = phosphine, pyridine, isocyanide)

International Nuclear Information System (INIS)

Lorenz, B.; Findeisen, M.; Olk, B.; Schmidt, K.

1988-01-01

Technetium pentacarbonyl bromide reacts with π-acceptor ligands L (L = phosphine, pyridine, isocyanide) to form disubstituted compounds of the type Tc(CO) 3 BrL 2 . The stereochemistry of the complexes was established by infrared and 1 H-NMR measurement. Chemical shifts and the half-widths of the 99 Tc-NMR signals are discussed. (author)

Mixed-ligand complexes of technetium-III. Synthesis and characterization of [bis(diphenylphosphino)ethane]tetrakis(trimethylphosphite)tech netium(I) hexafluorophosphate, [Tc(DPPE)(TMP)4]PF6

International Nuclear Information System (INIS)

Abram, U.; Beyer, R.; Muenze, R.; Stach, J.; Kaden, L.; Lorenz, B.; Findeisen, M.

1989-01-01

The diamagnetic technetium(I) complex [Tc(DPPE)(TMP) 4 ]PF 6 was prepared from [Tc(N 2 )H(DPPE) 2 ] and characterized by elemental analysis. 1 H- and 99 Tc-NMR spectroscopy and fast atom bombardment mass spectrometry. [Tc(DPPE)(TMP) 4 ]PF 6 is a prototype compound for technetium complexes with mixed phosphine-phosphite coordination spheres. (author)

An investigation into the technical feasibility of cyclotron production of technetium-99m

International Nuclear Information System (INIS)

Egan, G.F.; Lagunas-Solar, M.C.

1994-01-01

The role of technetium-99m in nuclear medicine is well established with 80 per cent to 90 per cent of all nuclear medicine studies utilising this isotope. Technetium-99m is currently produced from nuclear reactors via production of the parent radionuclide molybdenum-99. The reactor production of 99m Tc has both significant financial and environmental costs, with unresolved problems in the areas of radioactive waste disposal and reactor decommissioning. Recent scientific publications have indicated that medical quality 99m Tc may be produced using cyclotrons without having the associated problems of waste disposal and decommissioning. Further scientific research is now required to demonstrate the feasibility of this cyclotron production technique. A collaboration between the Cyclotron and PET Centre, Austin Hospital, the National Medical Cyclotron, ANSTO, Sydney, and the Crocker Nuclear Laboratory, University of California, Davis, USA has been proposed. The general objective of the proposed collaboration is to acquire additional scientific data to evaluate the 99m Tc cyclotron production method and to determine the feasibility of cyclotron technology for Australian nuclear medicine. 16 refs., 2 tabs

Studying the iodine leaching from the compositions based on epoxide resin and lead iodide

International Nuclear Information System (INIS)

Kalinin, N.N.; Elizarova, A.N.

1988-01-01

When studying iodine leaching, the possibility to use solid compositions, produced by incorporation of dry powdered lead iodide and its aqueous suspension into epoxide resin for long-term immobilization of iodine-129 under conditions of monitored storage, is evaluated. Analysis of the results obtained has shown that leaching rate in the first 4 days has the maximum value and constitutes (4.2 - 2700.0) x 10 -6 cm/day. Then the process of leaching is determined by diffusion mechanism. For samples, prepared by wet lead iodide incorporation the rate of leaching is higher than that of the corresponding samples prepared by dry compound incorporation

Sorption of iodine, chlorine, technetium and cesium in soil

International Nuclear Information System (INIS)

Soederlund, M.; Lusa, M.; Lehto, J.; Hakanen, M.; Vaaramaa, K.

2011-01-01

The safety assessment of final disposal of spent nuclear fuel will include an estimate for the behavior of waste nuclides in the biosphere. As a part of this estimate also the sorption of radioactive iodine, chlorine, technetium and cesium in soil is to be considered. The chemistry and the sorption of these radionuclides in soils are described in this literature survey. Behavior of I-129, Cl-36 and Tc-99 in the environment is of great interest because of their long half-lives and relatively high mobilities. The importance of Cs-135 arises from its high content in spent nuclear fuel and long physical half-life, even though it is considered relatively immobile in soil. Factors affecting the migration and sorption of radionuclides in soils can be divided into elemental and soil specific parameters. The most important elemental factor is the speciation of the element, which is influenced by the soil redox potential, pH and complex forming ligands. Soil micro-organisms can either serve as sorbents for radionuclides or affect their speciation by altering the prevailing soil redox conditions. Soil organic matter content and mineral properties have a marked influence on the retention of radionuclides. The sorption of anionic radionuclides such as I-, Cl- and TcO 4 - is pronounced in the presence of organic matter. Clay minerals are known to bound cesium effectively. The effect of speciation of radioactive iodine, chlorine, technetium and cesium in soil is considered in this study, as well as the effect of soil micro-organisms, organic matter and mineral properties. (orig.)

Enthalpies of potassium iodide dissolution in dimethyl acetamide mixtures with water

International Nuclear Information System (INIS)

Privalova, N.M.; Gritsenko, S.I.; Vorob'ev, A.F.

1986-01-01

Enthalpies of potassium iodide dissolution in mixed dimethyl acetamide - water solvent at 298.15 K in the whole range of dimethyl acetamide compositions are measured by the calorimetric method. From the plots of KI dissolution enthalpy dependence and dependence of experimental ΔH p∞ 0 value deviations from calculational ones on solvent composition, as well as from the results of calculation of solvate shell composition of potassium iodide ions in the mixed solvent, it is obvious that in the region of 0-15 mol% concentrations of dimethyl acetamide insufficient enrichment of solvate ion shells by dimethyl acetamide (DMAA) occurs, in the region of 15-40 mol% DMAA compositions enrichment of solvate shells of ions by water occurs, in the region of 40-100 mol% DMAA enrichment of solvate ion shells by the organic component in comparison with mixture compostion occurs. Maximum enrichment of solvate ion shells by mixture components in three above mentioned regions of the mixed solvent occurs at 10, 30 and 80 mol% DMAA concentrations

Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

Science.gov (United States)

Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

2016-01-01

A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

Rapid, specific determination of iodine and iodide by combined solid-phase extraction/diffuse reflectance spectroscopy

Science.gov (United States)

Arena, Matteo P.; Porter, Marc D.; Fritz, James S.

2002-01-01

A new, rapid methodology for trace analysis using solid-phase extraction is described. The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse reflectance spectroscopy of the amount of analyte extracted on the disk surface. This method, which is adaptable to a wide range of analytes, has been used for monitoring ppm levels of iodine and iodide in spacecraft water. Iodine is used as a biocide in spacecraft water. For these determinations, a water sample is passed through a membrane disk by means of a 10-mL syringe that is attached to a disk holder assembly. The disk, which is a polystyrene-divinylbenzene composite, is impregnated with poly(vinylpyrrolidone) (PVP), which exhaustively concentrates iodine as a yellow iodine-PVP complex. The amount of concentrated iodine is then determined in only 2 s by using a hand-held diffuse reflectance spectrometer by comparing the result with a calibration curve based on the Kubelka-Munk function. The same general procedure can be used to determine iodide levels after its facile and exhaustive oxidation to iodine by peroxymonosulfate (i.e., Oxone reagent). For samples containing both analytes, a two-step procedure can be used in which the iodide concentration is calculated from the difference in iodine levels before and after treatment of the sample with peroxymonosulfate. With this methodology, iodine and iodide levels in the 0.1-5.0 ppm range can be determined with a total workup time of approximately 60 s with a RSD of approximately 6%.

High Photon-to-Current Conversion in Solar Cells Based on Light-Absorbing Silver Bismuth Iodide.

Science.gov (United States)

Zhu, Huimin; Pan, Mingao; Johansson, Malin B; Johansson, Erik M J

2017-06-22

Here, a lead-free silver bismuth iodide (AgI/BiI 3 ) with a crystal structure with space group R3‾ m is investigated for use in solar cells. Devices based on the silver bismuth iodide deposited from solution on top of TiO 2 and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) as a hole-transport layer are prepared and the photovoltaic performance is very promising with a power conversion efficiency over 2 %, which is higher than the performance of previously reported bismuth-halide materials for solar cells. Photocurrent generation is observed between 350 and 700 nm, and the maximum external quantum efficiency is around 45 %. The results are compared to solar cells based on the previously reported material AgBi 2 I 7 , and we observe a clearly higher performance for the devices with the new silver and bismuth iodides composition and different crystal structure. The X-ray diffraction spectrum of the most efficient silver bismuth iodide material shows a hexagonal crystal structure with space group R3‾ m, and from the light absorption spectrum we obtain an indirect band gap energy of 1.62 eV and a direct band gap energy of 1.85 eV. This report shows the possibility for finding new structures of metal-halides efficient in solar cells and points out new directions for further exploration of lead-free metal-halide solar cells. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Sterol regulatory element-binding proteins are regulators of the sodium/iodide symporter in mammary epithelial cells.

Science.gov (United States)

Wen, G; Pachner, L I; Gessner, D K; Eder, K; Ringseis, R

2016-11-01

The sodium/iodide symporter (NIS), which is essential for iodide concentration in the thyroid, is reported to be transcriptionally regulated by sterol regulatory element-binding proteins (SREBP) in rat FRTL-5 thyrocytes. The SREBP are strongly activated after parturition and throughout lactation in the mammary gland of cattle and are important for mammary epithelial cell synthesis of milk lipids. In this study, we tested the hypothesis that the NIS gene is regulated also by SREBP in mammary epithelial cells, in which NIS is functionally expressed during lactation. Regulation of NIS expression and iodide uptake was investigated by means of inhibition, silencing, and overexpression of SREBP and by reporter gene and DNA-binding assays. As a mammary epithelial cell model, the human MCF-7 cell line, a breast adenocarcinoma cell line, which shows inducible expression of NIS by all-trans retinoic acid (ATRA), and unlike bovine mammary epithelial cells, is widely used to investigate the regulation of mammary gland NIS and NIS-specific iodide uptake, was used. Inhibition of SREBP maturation by treatment with 25-hydroxycholesterol (5 µM) for 48h reduced ATRA (1 µM)-induced mRNA concentration of NIS and iodide uptake in MCF-7 cells by approximately 20%. Knockdown of SREBP-1c and SREBP-2 by RNA interference decreased the mRNA and protein concentration of NIS by 30 to 50% 48h after initiating knockdown, whereas overexpression of nuclear SREBP (nSREBP)-1c and nSREBP-2 increased the expression of NIS in MCF-7 cells by 45 to 60%, respectively, 48h after initiating overexpression. Reporter gene experiments with varying length of NIS promoter reporter constructs revealed that the NIS 5'-flanking region is activated by nSREBP-1c and nSREBP-2 approximately 1.5- and 4.5-fold, respectively, and activation involves a SREBP-binding motif (SRE) at -38 relative to the transcription start site of the NIS gene. Gel shift assays using oligonucleotides spanning either the wild-type or the

Technetium-99m Sestamibi in Multiple Myeloma

International Nuclear Information System (INIS)

Saber, R.A.

2002-01-01

Technetium-99m 2-methoxy - isobutyl - isonitrile (99mTc-MIBI) has been reported to be useful in evaluating patients with multiple myeloma. The aim of this study is to evaluate the role of technetium-99m sestamibi (99mTc-MIBI) scintigraphy in the diagnosis. staging and follow-up of patients with multiple myeloma. Methods and Materials: twenty-five consecutive patients with multiple myeloma were studied using 99mTc- MIBI. Of the 25 patients included in this study, 6 were in stage I, II in stage II and 8 in stage III. Anterior and posterior whole-body imaging were obtained 20 min after I.V. injection of 740 MBq of 99mTc-MIBI. Four different MIBI patterns could be described in our patients: physiological (P), diffuse (D), focal (F) and combined diffuse and focal (D+F). All patients in stages II and III as well as 3 patients in stage I were treated with chemotherapy (cyclophosphamide and prednisone) then 99mTc-MlBI scans were repeated after 6 courses. Results: in comparison to conventional X-ray skeletal survey, 99mTc-MIBI scans showed a higher number of myeloma bone disease at diagnosis. All patients with stage II and III multiple myeloma were positive with 99mTc-MlBl scans at diagnosis. The pattern of positive MIBI accumulation was diffuse in 13 (52%) patients, focal in 4 (16%) and combined focal and diffuse in 6 (24%) patients. The intensity of 99mTc-MIBI correlated with disease activity as determined by lactate dehydrogenase (LDH), number of plasma cells in bone marrow and serum electrophoresis. There was a direct correlation between 99mTc-MIBI scan result and clinical outcome of patients following 6 courses of chemotherapy. Sensitivity and specificity of 99mTc-MIBI scintigraphy in detecting myeloma bone lesions were 92% and 90% respectively. Conclusion: 99mTc-MIBI scintigraphy is a reliable method to evaluate bone marrow activity in patients with multiple myeloma and follow-up of myeloma bone lesions