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Sample records for dependent radiotracer study

  1. Radiotracer techniques in hydrological studies

    International Nuclear Information System (INIS)

    Oladipo, M.O.A.; Funtua, I.I.

    2000-07-01

    The use of radioactive tracers particularly short-lived radioisotopes frequently offers advantages over conventional methods of analyses. Applications of nuclear techniques in the field of hydrology constitute important and sometimes unique tools for obtaining critical information needed for water resources management. Essentially, radiotracer techniques offer a safe, cost effective and powerful tool in the assessment, management and protection of water resources. The Centre for Energy Research and Training, Ahmadu Bello University, Zaria of late has been offering consultancy services to some industries in the area of radiotracer technique. The first nuclear reactor in Nigeria, the MNSR, is expected to be commissioned in the Centre very soon. Many short-lived radioisotopes such as Cu-64, Ga-72, Br-82, Hg-197 etc which are very important in hydrological studies can be produced by the MNSR facility. This article reports on the basic principles of the technique and its roles in hydrology

  2. Radiotracer studies with abomasum

    International Nuclear Information System (INIS)

    Angelo, I.A.

    1979-01-01

    14 C-amino acid incorporation into the abomasal tissue proteins was studied in the presence of milk constituents and tissue extracts. Addition of either casein, α-lactalbumin or fresh milk in the assay system inhibited the incorporation phenomenon. Milk whey, boiled milk or tissue extracts from liver and kidney on the other hand, distinctly stimulated incorporation of amino acids. A 14 C-labelled prorennin preparation was obtained in vitro from kid abomassum. Sephadex G-100 gel filtration resolved it into two components. The first protein positive component was associated with radioactivity. (orig.) 891 AJ/orig. 892 MKO [de

  3. Application of radiotracers in environmental studies

    International Nuclear Information System (INIS)

    Rathore, V.S.

    1994-01-01

    An attempt has been made to present recently emerging trends in the applicability of radiotracers in environmental studies. Since the topic is of general interest and still in the infancy, basic aspects of sampling, instrumentation and methodology are also covered

  4. Radiotracer studies for coastal zone management

    International Nuclear Information System (INIS)

    Hughes, C.; Kluss, T.; Airey, P.

    2001-01-01

    Coastal engineers and coastal zone managers increasingly rely on numerical models of fluid, sediment and contaminant dynamics. These are used to underpin coastal structure design and to predict environmental response to specific events such as storms or pollutant spills, and gradual changes such as sea-level rise or changes in bathymetry. Radiotracer techniques can be used to provide dynamic data on the movement of a specific patch of water, sediment or pollutant over time, which can be compared with model predictions. Two case studies are presented where radiotracer studies were used to improve confidence in numerical models of: (1) 2D hydrodynamics and sediment transport at the Port of Songkhla, Thailand; and (2) 3D hydrodynamics and algal bloom transport in Manila Bay, Philippines

  5. Adsorption on smooth electrodes: A radiotracer study

    International Nuclear Information System (INIS)

    Rice-Jackson, L.M.

    1990-01-01

    Adsorption on solids is a complicated process and in most cases, occurs as the early stage of other more complicated processes, i.e. chemical reactions, electrooxidation, electroreduction. The research reported here combines the electroanalytical method, cyclic voltammetry, and the use of radio-labeled isotopes, soft beta emitters, to study adsorption processes at smooth electrodes. The in-situ radiotracer method is highly anion (molecule) specific and provides information on the structure and composition of the electric double layer. The emphasis of this research was on studying adsorption processes at smooth electrodes of copper, gold, and platinum. The application of the radiotracer method to these smooth surfaces have led to direct in-situ measurements from which surface coverage was determined; anions and molecules were identified; and weak interactions of adsorbates with the surface of the electrodes were readily monitored. 179 refs

  6. Species dependent radiotracer study of Cr(VI) and Cr(III) using an aqueous biphasic system

    Energy Technology Data Exchange (ETDEWEB)

    Roy, K.; Lahiri, S. [Chemical Sciences Div., Saha Inst. of Nuclear Physics, Kolkata (India)

    2008-07-01

    The speciation study of Cr(III) and Cr(VI) was carried out using a polyethylene glycol (PEG) based aqueous biphasic extraction system (ABS). Neutron activated Cr(III) and Cr(VI) salts were assayed in a HPGe detector before and after employing aqueous biphasic extraction. Different salts of various salting out abilities were taken as the salt rich phase. The best condition for extraction of Cr(VI) and the maximum differential attitude of ABS to Cr(VI) and Cr(III) was observed when 2 M Na{sub 2}SO{sub 4} and PEG 4000 (50% w/w) solutions were used. Cr(III) can also be extracted by the PEG with prior complexation with diphenylthiocarbazone (dithizone). The chromium dithizonate complex is quantitatively extracted by the PEG rich phase. (orig.)

  7. 3. Radiotracers

    International Nuclear Information System (INIS)

    Musilek, L.

    1992-01-01

    The chapter deals with basic characteristics of radiotracer methods, with demands placed on radiotracers, their assets and drawbacks, the applicability of the method to the study of laminar flows, and examples of radiotracer applications in biochemistry, metallurgy, in the investigation of the permeation and passage of gases and liquids, in the examination of wear of machine components, and in criminological practice. An overview of the major radionuclides and of radiotracer applications is given. (Z.S.). 3 tabs., 5 figs., 25 refs

  8. Use of Radiotracers to Study Surface Water Processes

    International Nuclear Information System (INIS)

    2015-03-01

    This publication represents a sound knowledge base for the conduct of radiotracer studies in the environment, with papers on radiotracer methodology, radiation protection and regulation, data analysis and modelling. Environmental case histories from five Member States - Australia, Brazil, France, the Republic of Korea and Sweden - provide information on conducting studies involving he use of radioactive tracers. These case histories are not meant as guidelines for preparing a field study but can rather serve as examples of the type, caution and extent of work involved in environmental studies using radiotracers. This publication can provide guidance for conducting potential future training events in the use of radioactive traces in the environment and can serve as a key reference to all concerned directly with surface water processes

  9. Use of radiotracers for studies of metal sorption behaviour

    International Nuclear Information System (INIS)

    McCubbin, D.; Leonard, K.S.

    1995-01-01

    Radiotracers provide a convenient tool to study the behaviour of metal ions and other contaminants in natural waters. Furthermore, the use of radiotracers in controlled laboratory experiments provides an ideal approach for investigating, in a systematic manner, the role of individual parameters on processes, at mass concentrations found in the environment. A simplistic procedure has been developed to produce a thorium radiotracer ( 234 Th), in a similar chemical form (non-acidic) to that of the aquatic medium under investigation, to determine the kinetics of sorption to marine particulate material. The benefit of this procedure is that the system is likely to be perturbed to a lesser extent by changes in pH and dissolved Th species following tracer addition. Results from filtering different tracer batches through membranes, to determine the sorption characteristics prior to use, indicate that the physico-chemical behaviour of individual batches was extremely variable. Not surprisingly, the amount of uptake immediately following tracer additions to solutions containing marine particulate material was also variable. It is suggested that the role of tracer may be underestimated if added in acid form. Nevertheless, having accounted for the initial sorption, the subsequent uptake between different batches was reasonably reproducible. The usefulness of radiotracers is discussed in the context of these observations

  10. Application of radiotracer technology to the study of coastal processes

    International Nuclear Information System (INIS)

    Airey, P.; Szymczak, R.; Zaw, M.; Tu, J.; Kluss, T.; Barry, J.

    1999-01-01

    Recent progress at ANSTO in the applications of radiotracer techniques to the study of coastal processes is reviewed. Tracers are used in detailed studies of specific components of complex environmental systems and are applied to the evaluation and extension of numerical models. Examples include studies of the aggregation of sewage particles following release from ocean outfalls. The use of tracers to study the impact of storm events on bedload transport at depth has also been demonstrated

  11. Applications of radiotracer techniques for the toxicology studies of nanomaterials

    International Nuclear Information System (INIS)

    Ma Yuhui; Zhang Zhiyong; Zhang Yuan; He Xiao; Zhang Haifeng; Chai Zhifang

    2008-01-01

    With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the toxicology studies of nanomaterials, it is essential to know the basic behaviors in vivo, that is absorption, distribution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and has got the chance to demonstrate its enchantment. In this presentation, studies on radiotracer techniques used in nanotoxicology will be reviewed and new progresses at Institute of High Energy Physics, including the label methods and behaviors of labeled nanomaterials, such as fullerene, carbon nanotubes, and nanometer metal oxide in animals and in aquatic environments will be reported. (authors)

  12. Radiotracer methodology

    International Nuclear Information System (INIS)

    Eng, R.R.

    1988-01-01

    In 1923, George Hevesy demonstrated the distribution of radioactive lead in the horsebean plant. This early demonstration of the potential use of radiotracers in biology was reinforced when J.G. Hamilton and colleagues used iodine-131 for diagnostic purposes in patients. Then in 1950 Cassen et al. designed the first scintillation counter for measuring radioiodine in the body, using calcium tungstate crystals coupled to a photomultiplier tube. This was followed by the development of the Anger camera, which permitted visualization of radiotracer distribution in biological systems. From these significant early discoveries to the present, many advances have been made. They include the discovery and production of many useful radioisotopes; the formulation of these radioisotopes into useful radiotracers; the advent of first- , and second-, and third-generation instrumentation for monitoring in vitro and in vivo distributions of new radiotracers; and the application of this knowledge to allow us to better understand physiological processes and treat disease states. Radiotracer techniques are integral to numerous techniques described in this volume. Autoradiography, nuclear scintigraphy, positron emission tomography, and single-photon emission computed tomography (SPECT) are all dependent on an understanding of radiotracer techniques to properly utilize these probe devices

  13. Study on industrial application of radiotracer

    International Nuclear Information System (INIS)

    Kim, Jae Rok; You, Young Soo; Jin, Joon Ha; Han, Hyeon Soo; Park, Choon Deuk

    1991-03-01

    Mixing rates of powdered raw materials of welding electrodes were measured using technetium-99m adsorbed raw material components as tracer. (1) Adsorbed technetium-99m was not detached during studies. (2) Taking more than 10 samples of the smallest possible but equal size at definite mixing stages were important in assuring reliability. (3) Mixing rates were independent on mixing ratio of the two components insofar as the specific gravity and grain size are same. (4) Mixing rates were inversely proportional to the specific gravity and grain size but proportional to mixing ratios in case of the specific gravity difference was more than 1.5. (Author)

  14. MONOAMINE OXIDASE: RADIOTRACER DEVELOPMENT AND HUMAN STUDIES.

    Energy Technology Data Exchange (ETDEWEB)

    FOWLER,J.S.; LOGAN,J.; VOLKOW,N.D.; WANG,G.J.; MACGREGOR,R.R.; DING,Y.S.

    2000-09-28

    PET is uniquely capable of providing information on biochemical transformations in the living human body. Although most of the studies of monoamine oxidase (MAO) have focused on measurements in the brain, the role of peripheral MAO as a phase 1 enzyme for the metabolism of drugs and xenobiotics is gaining attention (Strolin Benedetti and Tipton, 1998; Castagnoli et al., 1997.). MAO is well suited for this role because its concentration in organs such as kidneys, liver and digestive organs is high sometimes exceeding that in the brain. Knowledge of the distribution of the MAO subtypes within different organs and different cells is important in determining which substrates (and which drugs and xenobiotics) have access to which MAO subtypes. The highly variable subtype distribution with different species makes human studies even more important. In addition, the deleterious side effects of combining MAO inhibitors with other drugs and with foodstuffs makes it important to know the MAO inhibitory potency of different drugs both in the brain and in peripheral organs (Ulus et al., 2000). Clearly PET can play a role in answering these questions, in drug research and development and in discovering some of the factors which contribute to the highly variable MAO levels in different individuals.

  15. Study in flow rig by using radiotracer

    International Nuclear Information System (INIS)

    Widatalla, R. K.

    2012-06-01

    Application of radioisotope technology have proved itself to be effective techniques for troubleshooting and optimizing industrial process in petrochemical industry In this study gamma scanning technique has been employed for better understanding of malfunctions by using the flow rig system. The scanning were carried out using 9 9mT C gamma radiation source with activity of 1 mCi and quantity of 5 ml to measure the flow rate for the water flow rig The experiment was repeated by reducing the data interval time to get more precise result. The investigations were also carried out using 5 ml of 9 9mT C with activity of 0.3 mCi for measuring the Residence Time Distribution (RTD) inside the flow rig tank which enables calculating the effective volume for the operating tank and its dead volume. The results proved that the technique is sensitive, reliable and can be adopted to investigate industrial reactors. (Author)

  16. Recoil generated radiotracers in studies of molecular dynamics

    International Nuclear Information System (INIS)

    Spicer, L.D.

    1981-01-01

    This chapter summarizes many of the contributions that the recoil technique of generating excited radiotracer atoms in the presence of a thermal environment is making to the field of chemical dynamics. Specific topics discussed critically include characterization of the generation and behavior of excited molecules including fragmentation kinetics and energy transfer, measurement of thermal and hot kinetic parameters, and studies of reaction mechanisms and stereochemistry as a function of reaction energy. Distinctive features that provide unique approaches to dynamical problems are evaluated in detail and the complementarity with more conventional techniques is addressed. Prospects for future applications are also presented

  17. Radiotracer studies of fungicide residues in food plants

    International Nuclear Information System (INIS)

    1990-04-01

    Agricultural fungicides are chemicals used on seeds, crops and in soils throughout the growing season. Fungicide treatments may lead to various levels of chemical residues in food commodities. Primary emphasis has been placed on ethylenebisdithiocarbamates (EBDCs), an important group of agrofungicides used in preparations for spraying or dusting major crops such as apples, pears, broccoli, cabbages, egg plants, cauliflower, grapes, lettuce, peppers, celery, cucumbers and tomatoes. Treatments with EBDCs result in terminal residues containing ethylenthiourea (ETU). This is a toxicologically significant decomposition product which has attracted considerable attention in recent years due to indications of its potential goitrogenic and carcinogenic properties. In recognition of the need for a coordinated examination of ETU levels in food, particularly under tropical conditions, the program of radiotracer techniques as a tool for studying fungicide residue problems on food was initiated in 1984. In current studies, three EBDCs, maneb, zineb and mancozeb from different manufacturers in different countries were analysed. This report describes the model protocols (Annexes I, II and III) as they were set up for determination of residues in commodities and soil, using radiotracer and conventional chromatographic techniques . In the 16 papers presented in this report C 14 -labelled EBDCs are determined in plants, vegetables, and soils, before and after cooking, as a function of time and of other agricultural parameters. Refs, figs and tabs

  18. Radiotracers for per studies of neurotransmitter binding sites: Design considerations

    International Nuclear Information System (INIS)

    Kilbourn, M.R.

    1991-01-01

    Neurotransmitter binding sites, such as receptors, neuronal uptake systems, and vesicular uptake systems, are important targets for new radiopharmaceutical design. Selection of potential radioligands can be guided by in vitro laboratory data including such characteristics as selectivity and affinity for specific binding sites. However, development of PET radiotracers for use in vivo must include considerations of in vivo pharmacokinetics and metabolism. Introduction of potential radioligands is further narrowed by the demands of the radiochemical synthesis, which must produce radioligands of high chemical and radiochemical purity and of high specific activity. This paper will review examples of previous and current attempts by radiopharmaceutical chemists to meet these demands for new positron emitter-labeled radioligands for PET studies of a wide array of neurotransmitter binding sites

  19. Design of laboratory radiotracer studies in marine radioecology

    International Nuclear Information System (INIS)

    Schulte, E.H.

    1997-01-01

    A condensed description of methods used in laboratory radiotracer studies in marine radioecology is presented showing also the difficulties which may be encountered in order to obtain realistic and comparable information on the general behaviour of radionuclides in marine organisms. Practical guidance on the choice of the biological material and how to setup laboratory experiments and to control properly important experimental conditions are given. Key parameters like concentration factors and biological half-lives are defined and the theoretical estimation and practical determination of input, uptake, accumulation and loss of radionuclides in marine biota are formulated by the aid of mathematical equations. Examples of uptake and loss curves obtained in the laboratory are shown. The importance of some environmental factors (temperature, food, growth) on uptake and loss of radionuclides are demonstrated. Comparison of experimental and field data of concentration factors is reported to show the difficulty in extrapolating from laboratory experiments to nature. (author)

  20. Study of regional pulmonary gas exchange using radiotracers

    International Nuclear Information System (INIS)

    Hichwa, R.D.

    1981-01-01

    Respiration involves the exchange of gases between the environment and the blood across the alveolar membrane. Four processes characterize the dynamics of gas exchange: ventilation, diffusion, perfusion and chemical binding with hemoglobin. A study was undertaken to investigate each of these processes, utilizing accelerator production and high yield synthesis of four gaseous radiotracers (/sup 81m/Kr, Ch 3 18 F, 11 CO, 15 O 2 ). Conventional gamma camera images and ancillary physiological data were acquired. Mathematical models were developed to predict the tracer clearance from the lungs during a breath hold and during washout post breath hold. Images of the insoluble /sup 81m/Kr synchronized with the tidal breathing maneuver depict regional ventilation. Tracer bolus inhalation, relative compliance and regional phase information are obtained from krypton dCynamic studies. More soluble CH 3 18 F is used to determine regional pulmonary perfusion during a breath hold. Respiratory clearance of seven, inert, positron-emitting radiotracers define the tracer volume of distribution. The tight-binding of 11 CO to hemoglobin permits the regional measurement of carbon monoxide pulmonary diffusion capacity. A relative CO blood:gas partition coefficient is calculated from the washout of no-carrier-added levels of 11 CO and verified by in vitro radiometric measurements. Regional oxygen pulmonary diffusion capacity determined from 15 O 2 clearance during a breath hold reveals results similar to those obtained with CO. All experimental data are in good agreement with the predictions of a two-compartment open model. A more advanced oxygen model is presented that incorporates radioactive oxygen exchange with stable oxygen on the hemoglobin molecule and metabolic removal of the tracer at the tissues

  1. Radiotracer studies on radionuclide and trace element cycling in corals

    International Nuclear Information System (INIS)

    Fowler, S.W.; Teyssie, J.L.; Acosta, A.; Gattuso, J.P.; Jaubert, J.

    1999-01-01

    Microcosm experiments were designed in which microcolonies of three coral species were exposed to gamma-emitting radiotracers of trace metals and radionuclides ( 110 Am, 109 Cd. 57 Cocyanocobalamin, 110 Ag, 134 Cs, 65 Zn, 60 Co, 75 Se, 85 Sr, 133 Ba, 54 Mn) to determine uptake and loss as well as distribution in tissue, skeleton and zooxanthellae. Following a seven day exposure in seawater, the degree of uptake (CF = concentration factor) for a given element was highly dependent on species. The highest CF s , in whole colonies were found for 100m Ag(82-172), 57 Co (68-124) and 65 Zn (41-52); the lowest CF s , were noted for the soluble radionuclides Cs (1-2) and Sr (2-9). Low CF s , were recorded in skeleton and increased by roughly an order of magnitude between skeleton, tissue and zooxanthellae. 241 Am is readily taken up by dead skeleton (CF=31-49), whereas in living corals it is preferentially accumulated by the tissue (CF=51-120) which acts as a partial barrier against contamination of the internal skeleton (CF=6-10). The chemical species of the element can also affect uptake by corals, as evidenced by the order of magnitude greater bioaccumulation of organic cobalt compared to the inorganic form in tissues. Once accumulated, some of the elements tested (e.g. Cd, Co) are strongly retained with biological half-lives as long as several months

  2. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

  3. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    International Nuclear Information System (INIS)

    Rydberg, J.

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs

  4. Radiotracer application in bedload transport: case studies at Calcutta port

    International Nuclear Information System (INIS)

    Pendharkar, A.S.; Yelgoankar, V.N.; Pant, H.J.; Saravana Kumar, U.; Mendhekar, G.N.; Navada, S.V.

    1994-01-01

    Radioactive isotopes as tracers are widely used to study the dynamic behaviour of sediments in navigation channels in harbours, estuaries and in rivers. Four radioactive tracer experiments were carried out in Calcutta Port during 1985-1992, to investigate the suitability of the dumping sites for the dredged sediments. Two experiments were carried out off Sagar island and the other two were carried out off Haldia river buoy. For all the experiments radiotracers used was 46 Sc labelled 1% scandium glass powder having the same specific gravity and particle size distribution as the natural sediment in the areas of investigation. About 370 GBq (10 Ci) each off Sagar island and 185 GBq (5 Ci) each off Haldia river buoy was used. An extensive background survey of the area was carried out using waterproof scintillation detectors to measure the natural radiation level prior to the experiments. The tracer was released on to the sea bed and its movement was followed by waterproof scintillation detector. The studies indicate the general direction of movement of sediment in the area of interest and it is found to be away from the shipping channels. The velocity of transport is calculated from transport diagrams of two successive trackings. The transport thickness E, estimated for the experiments off Haldia river buoy, is about 2 to 3 cm. (author). 3 refs., 7 figs., 2 tabs

  5. Study of wastewater treatment plants efficiency using radiotracers

    International Nuclear Information System (INIS)

    Dawi, W. D. A.

    2010-11-01

    This study was performed to investigate and diagnose hydrodynamic behavior of the Military Hospital wastewater treatment plant. The plant comprises two units of treatment, each of them has a separate system. The investigation was carried out using ''1''3''1I as a radiotracer. The concept of residence time distribution (RTD) was used to investigate the efficiency of the aeration tanks, secondary clarifiers and chlorine tanks. Preliminary treatment and modeling of the trace data was performed using two software package applied by the International Atomic Energy Agency (IAEA) namely 4621 counter version 1.0.0 and RTD software. Plug flow pattern (parallel flow) was detected in the aeration tank and secondary clarifier of system 1 in one unit, while no homogeneous mixing was observed in the chlorine tank. Short - circuiting (by - passing) was evident in the aeration tank of system 2 in the other unit, which significantly reduced the operating efficiency. The percentage of dead volumes clearly suggests that the aeration tank and secondary clarifier were well utilized in the whole plant. (Author)

  6. Preliminary study of the use of radiotracers for leak detection in industrial applications

    International Nuclear Information System (INIS)

    Wetchagarun, S; Petchrak, A; Tippayakul, C

    2015-01-01

    One of the most widespread uses of radiotracers in the industrial applications is the leak detection of the systems. This technique can be applied, for example, to detect leak in heat exchangers or along buried industrial pipelines. The ability to perform online investigation is one of the most important advantages of the radiotracer technique over other non-radioactive leak detection methods. In this paper, a preliminary study of the leak detection using radiotracer in the laboratory scale was presented. Br-82 was selected for this work due to its chemical property, its suitable half-life and its on-site availability. The NH 4 Br in the form of aqueous solution was injected into the experimental system as the radiotracer. Three NaI detectors were placed along the pipelines to measure system flow rate and to detect the leakage from the piping system. The results obtained from the radiotracer technique were compared to those measured by other methods. It is found that the flow rate obtained from the radiotracer technique agreed well with the one obtained from the flow meter. The leak rate result, however, showed discrepancy between results obtained from two different measuring methods indicating further study on leak detection was required before applying this technique in the industrial system. (paper)

  7. Preliminary study of the use of radiotracers for leak detection in industrial applications

    Science.gov (United States)

    Wetchagarun, S.; Petchrak, A.; Tippayakul, C.

    2015-05-01

    One of the most widespread uses of radiotracers in the industrial applications is the leak detection of the systems. This technique can be applied, for example, to detect leak in heat exchangers or along buried industrial pipelines. The ability to perform online investigation is one of the most important advantages of the radiotracer technique over other non-radioactive leak detection methods. In this paper, a preliminary study of the leak detection using radiotracer in the laboratory scale was presented. Br-82 was selected for this work due to its chemical property, its suitable half-life and its on-site availability. The NH4Br in the form of aqueous solution was injected into the experimental system as the radiotracer. Three NaI detectors were placed along the pipelines to measure system flow rate and to detect the leakage from the piping system. The results obtained from the radiotracer technique were compared to those measured by other methods. It is found that the flow rate obtained from the radiotracer technique agreed well with the one obtained from the flow meter. The leak rate result, however, showed discrepancy between results obtained from two different measuring methods indicating further study on leak detection was required before applying this technique in the industrial system.

  8. Time-dependent recovery of in vivo binding sites after drug dosing: A method for radiotracer evaluation

    International Nuclear Information System (INIS)

    Kilbourn, Michael R.

    1997-01-01

    The recovery of in vivo binding sites for (±)-α-[ 11 C]methoxytetrabenazine, a radioligand for the monoamine vesicular transporter (VMAT2), was determined in mouse brain at various times following a pharmacological dose of tetrabenazine. Concentrations of in vivo radioligand binding sites progressively increased and had reached control values by 8.5 h, and this recovery was consistent with the pharmacokinetics of the competing drug tetrabenazine and its active metabolite, dihydrotetrabenazine. This study demonstrates a simple experimental protocol of using a single dose of a reversible competing drug and time-dependent measurements of in vivo binding of a radioligand. This protocol is suitable for testing the sensitivity of an in vivo radiotracer for measurement of varying concentrations of in vivo binding sites

  9. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    Science.gov (United States)

    Sugiharto, Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-06-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  10. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    International Nuclear Information System (INIS)

    Sugiharto; Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-01-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  11. Role of radiotracer in animal science

    International Nuclear Information System (INIS)

    Sivaprasad, N.

    2015-01-01

    Radiotracers have been used as radiopharmaceuticals for diagnosis and treatment of animal diseases in cattle and pet animals. In fact the veterinary nuclear medicine based on radiotracer as radiopharmaceuticals is established medical technique for functional studies and imaging of vital organs such as heart, lung, brain, spleen, liver, kidney etc for diagnosis as well as treatment of diseases such as cancers in animal. Besides, radiation from radioisotopes has been in use for radiation therapy of cancers in animals. The nuclear imaging using positron emitting radiotracer is gaining importance in the evolution of drug in small animals. In this respect, small animals have also contributed significantly in the development of radiopharmaceuticals particularly for biodistribution and bioscan studies. In fact, the quality control of radiopharmaceuticals in animals to test the safety is a mandatory requirement in the production of radiopharmaceuticals. In brief the animal science has contributed in various areas and facets of radiotracer techniques and its application vice versa the radiotracer techniques have contributed towards the progress of animal science. The animal science in combination with radiotracer has also contributed to the progress of other basic and applied sciences. Thus there exists a bond between radiotracer techniques and animal science. Some aspects of mutual dependence of animal science and radiotracer are elaborated

  12. FUEL CONTAMINATION IN A MARINE DIESEL ENGINE. A RADIOTRACER STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, B. E.

    1964-04-15

    A radiotracer method was applied to the problem of elucidating the mechanism of contamination of crankcase oil by fuel combustion products in a marine diesel engine. The method consisted of adding an oil soluble radioisotope to the fuel and tracing its route to the various lubricants used in the engine. It was found that of the total amount of combustion products and by-products which enter the crankcase oil, 65% enters by simple contamination via reintroduction of used cylinder lubricant and 35% by a condensation mechanism. (auth)

  13. Radiotracer study of phosphate exchange between whey and casein micelles in cow's milk

    International Nuclear Information System (INIS)

    Kolar, Z.I.; Verburg, T.G.; Dijk, H.J.M. van

    1998-01-01

    Radiotracer method has been applied to study exchange of calcium ions between the whey calcium salts and micellar calcium phosphate (MCP). The present paper deals with a similar study pertaining to phosphate ions. 32 P-labelled Na 2 HPO 4 was used as the radiotracer for inorganic phosphates of milk. After addition of the radiotracer to skimmed-milk, samples were taken regularly for 700 hours. In the samples casein micelles were separated from whey by ultracentrifugation and finally the radiotracer quantity i.e. 32 P-concentration in the whey samples was measured using a Liquid Scintillation Counter. Compartmental analysis and modelling were used to evaluate the thus obtained time curves for radiotracer quantity in whey. This analysis revealed the presence of three phosphate compartments i.e. exchangeable phosphate entities; one being the whey phosphate. The other two are associated with the exchangeable phosphates of MCP. The mean residence times of phosphate in the latter two compartment differ considerably pointing at two distinctly different embeddings of phosphate groups in the structure of the micellar calcium phosphate of the cow's milk casein. The obtained results are in fair agreement with the mentioned model of MCP

  14. A study of residence time distribution using radiotracer technique in the large scale plant facility

    Science.gov (United States)

    Wetchagarun, S.; Tippayakul, C.; Petchrak, A.; Sukrod, K.; Khoonkamjorn, P.

    2017-06-01

    As the demand for troubleshooting of large industrial plants increases, radiotracer techniques, which have capability to provide fast, online and effective detections to plant problems, have been continually developed. One of the good potential applications of the radiotracer for troubleshooting in a process plant is the analysis of Residence Time Distribution (RTD). In this paper, the study of RTD in a large scale plant facility using radiotracer technique was presented. The objective of this work is to gain experience on the RTD analysis using radiotracer technique in a “larger than laboratory” scale plant setup which can be comparable to the real industrial application. The experiment was carried out at the sedimentation tank in the water treatment facility of Thailand Institute of Nuclear Technology (Public Organization). Br-82 was selected to use in this work due to its chemical property, its suitable half-life and its on-site availability. NH4Br in the form of aqueous solution was injected into the system as the radiotracer. Six NaI detectors were placed along the pipelines and at the tank in order to determine the RTD of the system. The RTD and the Mean Residence Time (MRT) of the tank was analysed and calculated from the measured data. The experience and knowledge attained from this study is important for extending this technique to be applied to industrial facilities in the future.

  15. Radiotracer studies on protein metabolism in different focuses of growth in vivo

    International Nuclear Information System (INIS)

    Rapoport, E.A.; Konikova, A.S.

    1979-01-01

    The role of various components of protein turnover in the liver growth induced by partial hepatectomy or phenobarbital as well as in malignant tumours has been studied with a radiotracer method. The ratio of the utilized precursors of exo- and endogenous origin during the formation of protein in focuses of growth, is labile, depends on a number of factors and varies even in the subcellular structures of the cell nucleus. It is probable that due to their reutilization through transreactions the protein structural units have in some focuses of growth and during formation of some proteins a definite superiority over the free aminoacids. It is also shown that the release of proteins and their degradation products from Walker 256 carcinosarcoma and the reutilization of proteins and their degradation products by sarcoma M-1 contribute to the protein turnover in the tumours. 8author)

  16. Radiotracer study in a bubble column reactor (visbreaker)

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Gursharan Singh; Rohit Kulkarni; Pandit, A.B.; Kumar, M.M.; Berne, Ph.

    2004-01-01

    Radiotracer technique was used to measure residence time distribution (RTD) of fuel oil in a pilot-plant visbreaker with an objective to investigate hydrodynamic behaviour at different operating conditions. Bromine-82 as dibromobiphenyle was used as a tracer to measure RTD of the fuel oil. Mean residence times were determined from the measured RTD data. Tanks-in-series with backmixing model was used to simulate the measured RTD data. The results of simulation indicated that the visbreaker did not behave as a plug flow reactor as desired for visbreaking process. The presence of internals i.e. baffles inside the visbreaker decreases the mean residence time and backmixing. Thus, the designed internals have shown promising effect in terms of reduced backmixing in the visbreaker. (author)

  17. Estimation of tritium radiotracer activity for interconnection study in geothermal field

    International Nuclear Information System (INIS)

    Rasi Prasetio; Satrio

    2016-01-01

    Tritium radiotracer (3H) has been applied widely in many geothermal fields around the world. This application was done by injecting radiotracer with certain amount of activity into reinjection well in order to investigate interconnection between reinjection well with surrounding production wells. The activity of injected radiotracer must meets the field condition and the volume of reservoir, detection limit of instrument, as well as safety aspect for the workers and environment from radioactive hazard. The planning of injection process must consider the maximum permissible concentration (MPC) and minimum detection limit (MDL). Based on calculation, tritium radiotracer injection in Kamojang geothermal field can be done with minimal activity of 0.15 Ci and maximum 22100 Ci, while in Lahendong field minimum activity of 0.65 Ci and maximum 7230 Ci. In these two injection studies, tritium was detected in monitoring wells between MDL and MPC limit. By using this estimation calculation, the activity of tritium that released into the environment within safety limit, thus monitoring wells with undetectable tritium infer no connectivity between those wells with reinjection well. (author)

  18. Radiotracer in industry

    International Nuclear Information System (INIS)

    Jaafar Abdullah

    2005-01-01

    The use of radiotracers for troubleshooting and to investigate process phenomena in industrial plant equipment has specific advantages over conventional tracers. The main advantages of radiotracers owes to its physico-chemical compatibility, high detection sensitivity, ability of number of radiotracers for different phases, stability in harsh industrial environment and limited memory effects. This chapter covers the methodology which includes the selection of radiotracer, radioisotope generators, estimation of amount of radiotracer, injection systems, detection system and safety procedure. Leak detection, this topic discussed the detection by flowrate measurement, detection of RTD measurement, detection by direct tracer, detection in underground pipes using the static method and dynamic method. The topic namely Radiotracers for flowrate measurement discussed the following subjects: flowrate measurement, transit time methods, dilution methods, standards for flow measurement, multi-phase flow measurement. RTD measurement, this topic covers the basic flow concepts, the mathematical modelling, RTD software, bypassing or channelling, recirculation, trickle bed reactors studies, process diagnosis and analysis. Lastly, the topic cover other application of radiotracers in industry discussed the following subtopics: mixing and blending studies, measurement of volume, ventilation studies, oil field investigation, corrosion and wear studies, validation of CFD models

  19. The use of rare earth radiotracers in the study of solvent extraction kinetics

    International Nuclear Information System (INIS)

    Lim, T.M.; Tran, T.

    1993-01-01

    The suitability of rare earth radionuclides as tracers in research and industry are assessed. In general, the most desirable characteristics of radiotracers for process studies are a half-life in the range 5-200 days, a high yield, high energy γ-emission and low cost of production. The majority of rare earths have at least one radionuclide with acceptable characteristics. The application of radiotracers to the study of kinetics of rare earth solvent extraction have been studied using a modified Lewis cell. Terbium-160 was selected as the most suitable rare earth radionuclide for our experiments. Samples of both aqueous and organic phases were continuous withdrawn, monitored using an automated γ-counting system based on two sodium iodide detectors and then pumped back to the Lewis cell. Excellent results were obtained and the rate of extraction was shown to be first order with respect to the terbium concentration. 6 refs., 1 tab., 7 figs

  20. Principles of radiotracer methodology

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1975-06-01

    Information is presented on the properties of radioisotopes and radiations, methods and equipment for radiation detection, safety in handling radioactive materials, the biological effects of radiation, and the design of radiotracer studies. (LCL)

  1. Application of centrifuge modelling and radiotracers to migration studies of buried toxic waste

    International Nuclear Information System (INIS)

    Villar, H.P.

    1995-01-01

    A new technique to study the migration of souble waste components in soils, based on the application of centrifugue modelling and of selected short-lived radiotracers, is presented. The technique is based on the acceleration of the migration proceses of a specific tracer in a soil model, with simple and well-established scaling laws being used to interpret the results. The use of radiotracers allows geat flexibility and the adoption of a wide range of concentrations. Demosntrations of the technique have been carried out with two elements of radically distinct behaviour: iodine noted for its mobility in soils, and thallium, which tends to be strongly sorbed. Two different soil types have been used. The results semed to confirm what is known about the behaviour of both elements, so that the feasibility of the technique for such studies has been concluded. (author). 7 refs, 4 figs, 1 tab

  2. Uses and limits of radiotracers in the study of drugs and xenobiotics metabolism

    International Nuclear Information System (INIS)

    Cohen, Y.

    1980-01-01

    This review deals with scientific papers issued in 1977-1978, on labelling of drugs and xenobiotics and their metabolism. It is divided in five parts: site of label; in vivo metabolism in animals and human beings; in vitro metabolism on tissue slices, cells culture, microsomes, membrane receptors; metabolism of xenobiotics: nutrients, food additives, detergents, plastics and fabrics; discussion. Metabolic studies, nowadays, associate radiotracers, stable isotopes with high performing procedures for analytical separation [fr

  3. Sulfur and Iron Cycling in a Coastal Sediment - Radiotracer Studies and Seasonal Dynamics

    DEFF Research Database (Denmark)

    MOESLUND, L.; THAMDRUP, B.; JØRGENSEN, BB

    1994-01-01

    The seasonal variation in sulfate reduction and the dynamics of sulfur and iron geochemistry were studied throughout a year in sediment of Aarhus Bay, Denmark. A radiotracer method for measuring sulfate reduction rates was applied with incubation times down to 15 min and a depth resolution down...... to 2 mm in the oxidized surface layer of the sediment. The radiotracer data were analyzed by a mathematical model which showed that, due to partial, rapid reoxidation of radioactive sulfide during incubation, the actual reduction rates in this layer were probably underestimated 5-fold. In the deeper......, sulfidic zone, measured rates appeared to be correct. Sulfate reduction followed the seasonal variation in temperature with maximum activity at 1-2 cm depth in late summer. In spite of its rapid production, free H2S was detectable in the porewater only below the depth of free Fe2+ at 6-7 cm throughout...

  4. Studies on Se-Cr interactions in mungbean using radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Shanker, Karuna; Mishra, Seema; Srivastava, Shalini; Srivastava, Rohit; Dass, Sahab; Prakash, Satya; Srivastava, M M [Dayalbagh Educational Institute, Agra (India). Dept. of Chemistry

    1995-09-01

    The paper describes a preliminary report of hydroponic experiment on the effect of selenium (selenite and selenate) treatments on the absorption of trivalent and hexavalent chromium by mung bean (Phaseolus mungo) plant. The studies are mainly confined to animal system and little attention has been paid on Se-metal interactions, particularly with those of different oxidation states of selenium and chromium in plant system. (author). 8 refs., 1 tab.

  5. Radiotracer studies on molecular mechanisms of death and resuscitation

    International Nuclear Information System (INIS)

    Nikulin, V.J.; Pogossova, A.V.; Konikova, A.S.

    1980-01-01

    Tracer techniques and artificial circulation were applied to rabbits after death by anoxia and deep hypothermia in order to study molecular mechanisms. 60 min after death the biosynthesis and disintegration of protein RNA and DNA practically stopped in all organs. In animals cooled post mortem the process of biosynthesis and degradation of protein, RNA and DNA, as well as the physiological functions of the whole organism, were restored. (author)

  6. Studies on Se-Cr interactions in mungbean using radiotracers

    International Nuclear Information System (INIS)

    Shanker, Karuna; Mishra, Seema; Srivastava, Shalini; Srivastava, Rohit; Dass, Sahab; Prakash, Satya; Srivastava, M.M.

    1995-01-01

    The paper describes a preliminary report of hydroponic experiment on the effect of selenium (selenite and selenate) treatments on the absorption of trivalent and hexavalent chromium by mung bean (Phaseolus mungo) plant. The studies are mainly confined to animal system and little attention has been paid on Se-metal interactions, particularly with those of different oxidation states of selenium and chromium in plant system. (author). 8 refs., 1 tab

  7. Radiotracer and Sealed Source Applications in Sediment Transport Studies

    International Nuclear Information System (INIS)

    2014-01-01

    The investigation of sediment transport in seas and rivers is crucial for civil engineering and littoral protection and management. Coastlines and seabeds are dynamic regions, with sediments undergoing periods of erosion, transport, sedimentation and consolidation. The main causes for erosion in beaches include storms and human actions such as the construction of seawalls, jetties and the dredging of stream mouths. Each of these human actions disrupts the natural flow of sand. Current policies and practices are accelerating the beach erosion process. However, there are viable options available to mitigate this damage and to provide for sustainable coastlines. Radioactive methods can help in investigating sediment dynamics, providing important parameters for better designing, maintaining and optimizing civil engineering structures. Radioisotopes as tracers and sealed sources have been useful and often irreplaceable tools for sediment transport studies. The training course material is based on lecture notes and practical works delivered by many experts in IAEA supported activities. Lectures and case studies were reviewed by a number of specialists in this field

  8. Radiotracer studies of agrochemical residues in meat, milk and related products of livestock and poultry

    International Nuclear Information System (INIS)

    1987-01-01

    The joint FAO/IAEA programme was initiated in 1981 and terminates with this report. The specific objectives of the programme have been to evaluate the magnitude, fate and significance of agricultural chemical residues in edible tissues and by-products of livestock and poultry, aided by radiotracer techniques. It was anticipated that the data arising from studies conducted under this programme would be useful in assessing the toxicological significance of studied chemicals to exposed animals and to humans who may consume potentially polluted meat, milk or eggs. A separate abstract was prepared for each of the 13 papers in this report

  9. Radiotracer study of sorption of europium on Gorleben sand from aqueous solutions containing humic substances

    International Nuclear Information System (INIS)

    Benes, P.; Stamberg, K.; Siroky, L.; Mizera, J.

    2002-01-01

    The sorption of trace europium, as a trivalent actinide homologue, was studied in the system Gorleben sand - aqueous solution with the aim to elucidate its mechanism. Radiotracer method ( 152/154 Eu) and batch experiments were used. Simultaneously, the distribution of humic substances present in, or added to the system was measured. The evaluation of the sorption was complicated by the adsorption of Eu on the walls of polyethylene vials used for the experiments, which was rather high and had to be taken into consideration. It has been found that Eu sorption on Gorleben sand increases from pH 2 to pH 5-7 and then it decreases. The decrease is due to the complexation of Eu with humic substances leached from Gorleben sand at pH>7. The position of the sorption maximum depends on the composition of the solution and on the liquid-to-solid ratio. It is shifted to lower pH values in the presence of added humic acid (HA), which enhances Eu sorption at low PH values and suppresses it at pH values higher than 5. The regions of the enhancing/suppressing effects coincidence with the high/low adsorption of HA on Gorleben sand, respectively. The increasing ionic strength (from 0.01 to 0.1) and europium concentration (3.4 x 10 -8 to 9.3 x 10 -7 mol/l) suppress the relative sorption (expressed in %) at low pH values and enhance it at pH>6-8. Addition of carbonates (5 x 10 -3 mol/l) supports Eu sorption at pH>7.5 so that no decrease with pH is observed till pH 9. Alkaline leaching of the sand significantly changes most of the effects found. These results were qualitatively interpreted and conclusions were drawn on the mechanism of the sorption. (author)

  10. Radiotracer investigation to study residence time distribution in an evaporator system

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H J; Yelgaonkar, V N; Navada, S V [Isotope Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Determination of mean residence time, residence time distribution and evaluation of flow behavior in industrial process systems is of prime importance in order to control the process and to evaluate the performance of the process systems. This paper describes a case study carried out in an evaporator system in a sugar factory near Pune for determination of the mean residence time and residence time distribution using radiotracer technique. The mean residence time (MRT) was determined to be 4 seconds. The mathematical modelling of residence time distribution (RTD) data indicated the flow behaviour of the system to be a well mixed type. (author). 5 refs., 2 figs., 1 tab.

  11. Radiotracer study to investigate the dilution and dispersion of sewage off Worli coast

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Pendharkar, A.S.; Agashe, S.M.; Kumar, U.S.; Kulkarni, U.P.; Mendhekar, G.N.; Navada, S.V.

    1998-01-01

    Radiotracer experiments were carried out off Worli Coast, Mumbai to study the dilution and dispersion of sewage from the proposed out fall at 3000 m and existing out fall at 500 m from the shore. Dilutions observed were 2.3 x 10 7 at 3.3 km from the injection point for the disposal at 3,000 m and 6.9 x 10 5 at 5 km for the disposal at 500 m. Dispersion coefficients obtained from two dimensional advection dispersion model for the experiment off 500 m are Dx 15-18 m 2 /s and Dy = 0.5-2 m 2 /s. (author)

  12. Mixing studies at low grade vacuum pan using the radiotracer method

    International Nuclear Information System (INIS)

    Griffith, J.M

    1999-01-01

    In this paper, some preliminary results achieved in the evaluation of the homogenization time at a vacuum pan for massecuite b and seed preparation , using two approaches of the radiotracer method, are presented. Practically no difference between the o n line , using small size detector and the sampling methods, in mixing studies performed at the high-grade massecuite was detected. Results achieved during the trials performed at the vacuum station show that the mechanical agitation in comparison with normal agitation improves the performance of mixing in high-grade massecuite b and in seed preparation at the vacuum pan

  13. Mixing studies at low grade vacuum pan using the radiotracer method

    International Nuclear Information System (INIS)

    Griffith, J.M

    1999-01-01

    In this paper, some preliminary results achieved in the evaluation of the homogenization time at a Vacuum Pan for massecuite B and seed preparation , using two approaches of the radiotracer method, are presented. Practically no difference between the Ion Line , using small size detector and the sampling methods, in mixing studies performed at the high-grade massecuite was detected. Results achieved during the trials performed at the vacuum station show that the mechanical agitation in comparison with normal agitation improves the performance of mixing in high-grade massecuite b and in seed preparation at the vacuum pan

  14. A simple and efficient in vitro method for metabolism studies of radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Yoon; Choe, Yearn Seong E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Byung-Tae

    2001-05-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[{sup 18}F]fluoromethylbenzyl- ([{sup 18}F]1) and 4-[{sup 18}F]fluorobenzyl-piperidine moieties ([{sup 18}F]2) was studied and compared with the in vivo metabolism. Defluorination of the [{sup 18}F]1 mainly occurred to generate [{sup 18}F]fluoride ion both in vitro and in vivo. In contrast, the [{sup 18}F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[{sup 18}F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.

  15. A simple and efficient in vitro method for metabolism studies of radiotracers

    International Nuclear Information System (INIS)

    Lee, Sang-Yoon; Choe, Yearn Seong; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo; Kim, Byung-Tae

    2001-01-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[ 18 F]fluoromethylbenzyl- ([ 18 F]1) and 4-[ 18 F]fluorobenzyl-piperidine moieties ([ 18 F]2) was studied and compared with the in vivo metabolism. Defluorination of the [ 18 F]1 mainly occurred to generate [ 18 F]fluoride ion both in vitro and in vivo. In contrast, the [ 18 F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[ 18 F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers

  16. Bioaccumulation of arsenic and other heavy metals in the oyster crassostrea virginica: a radiotracer study

    International Nuclear Information System (INIS)

    Gomez Batista, M.; Alonso Hernandez, M. C.; Metian, A.; Buschiazzo, E.; Teyssie, J. L.; Cotret, O.; Fowler, S.W.; Warnau, M.

    2006-01-01

    Cienfuegos Bay, situated in the Southern part of Cuba, is a semi enclosed bay of important as natural resource for the country, due to industrial and artesian fishing activities, maritime transport, tourism industry and natural parks. During the last decade important economic and social development, around the bay has resulted in a significant increase in inputs of industrial and domestic wastes to its waters. Regarding arsenic, direct input occurred through the Nitrogen Fertilizer Factory, which was operating until 1989 and where two important accidental spills took place, in 1979 and 2001. Therefore, understanding the behaviour and fate of As in this region is of prime importance in order to be able to develop coastal zone monitoring programs and improve local marine resource protection and management. The objective of this work was to investigate the bioaccumulation behaviour of As and other co occurring metals in the edible oyster Crassostrea virginica, a specie that is abundant, widely distributed in the bay, and frequently eaten by local populations. Seven different metals (As, Ag, Cr, Co, Cd, Mn and Zn) were considered and their bioconcentration was studied using γ emitting radiotracers ( 73 As, 110m Ag, 51 Cr, 57 Co, 109 Cd, 54 Mn and 65 Zn). The organisms were exposed for 14 d to background concentrations of the seven metals via seawater and then held for 21 d under non contaminated conditions. During these periods, uptake and loss kinetics of the metal radiotracers were determined in whole body individuals. In addition, tissue distribution of the metals was determined at the end of both exposure and depuration periods. In another experiment, C. virginica was exposed to four increasing concentrations of As dissolved in seawater in order to determine possible differences in As bioaccumulation according to ambient contamination level. Uptake kinetics were expressed as the variation of the concentration factor (CF, ratio between radioactivity in the organism

  17. Novel in situ radiotracer methods for the direct and indirect study of chromate adsorption on alumina

    International Nuclear Information System (INIS)

    Gancs, L.; Nemeth, Z.; Horanyi, G.

    2002-01-01

    Radiotracer methods, particularly the radiotracer thin foil method, provide unique possibility of in situ monitoring of chromate adsorption on powdered adsorbents. Two different versions of the thin foil method can be distinguished. In the direct method, the species to be studied is labelled and the radiation measured gives direct information on the adsorption of this species. In the indirect method, a different labelled indicator species is added to the system and the adsorption of this species is followed and the adsorption of the species to be studied is determined based on analysis of the competitive adsorption processes. Both methods were used in the present study. In the in situ methods, the radiation measured consists of two main parts, one coming from the solution background, the other originating from the adsorption layer. In the case of the thin foil method using isotopes emitting soft β - radiation or low energy X-ray the solution background is governed and minimised by self-absorption of the radiation. In the direct study we applied an experimental methodology based on the energy selective measurement of the characteristic K α,β X-radiation emitted by the 51 Cr-labelled chromate species, whereas 35 S-labelled sulphate ions were used as the indicator species in the indirect study. (P.A.)

  18. Study of dilution of effluent discharged through a sea outfall near Mangalore using radiotracer technique

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.

    1987-01-01

    The fate of effluent discharged into water bodies is a matter of concern from the point of view of environmental pollution. Radiotracer techniques have been successfully used to study the change in concentration of effluents while being mixed with large water bodies. The technique used is to add a known concentration of radioactive tracer into the effluent stream and to measure the dilutions at different locations near the effluent discharge point with radiation detectors. M/s Mangalore Chemicals and Fertilizers Ltd (MCF) at Mangalore on the west coast of India disposes off the treated and initially diluted effluent at the rate of about 360 m 3 /h into the sea near by through an outfall extending about 100 meters into the sea. The effluent mainly contains ammonia in the range of 40-50 ppm as the pollutant. It was desired to measure the extent of dilution occurring to the effluent at a few locations of known distances along the sea shore from the discharge point of the effluent. Radiotracers 82 Br as ammonium bromide solution and tritium as tritiated water were employed for the study. The concentration measurement was done at site for 82 Br and by estimation of samples in the laboratory in the case of tritium. Dilution of the order of 1000 was obtained at about 100 meters distance for a continuous injection of about 4 hours. (author). 3 tables, 3 figures

  19. Radiotracer study on dispersion of sewerage off Mumbai Coast in Western India

    International Nuclear Information System (INIS)

    Kumar, U.S.; Yelgaonkar, V.N.; Navada, S.V.

    1997-01-01

    Municipal Corporation of Greater Mumbai discharges the treated sewage at various locations off Mumbai coast. One such discharge point is located near Colaba near South Mumbai. Screened, degritted and aerated sewage is discharged through a 1 m diameter steel pipe by gravity to the diffuser installed on the sea bed at 1.1 km away from the shore. A radiotracer study was carried out to evaluate the dilution and dispersion pattern of the sewage at different points from the disposal point. The experiment was carried out during high tide. About 110 GBq of 82 Br was used as the tracer. A dilution factor of about 5.5 x 10 3 was obtained at a distance of 4.3 km from the outfall. The dilution downshore was small even for a long distance due to strong unidirectional currents. Comparable dilution factors were also obtained by Brooks' model. Vertical tracer profiles showed that the waste plume was well mixed over a depth of 2 to 3 m from the surface. A 2-D advection simulation model was employed to simulate the spatial and temporal distribution of the radiotracer data. From the model simulation best fit was obtained for dispersion coefficients Dx = 15 m 2 .s -1 and Dy = 2m 2 .s -1 . The dispersion coefficients can be used for predicting the effluent dispersion under different outfall and disposal conditions. The tracer pattern at Colaba and Malad indicated no possibility of contamination of the beaches

  20. A radiotracer for In vivo studies of acetylcholinesterase: p-[{sup 18}F]fluorodonepezil

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. Y.; Choi, Y. S.; Choi, Y.; Kim, S. E.; Lee, K. H.; Kim, B. T. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, J. W. [Seoul National Univ., Seoul (Korea, Republic of)

    1999-05-01

    Alzheimer's disease (AD) is one of senile dementia caused by lack of acetylcholine in central nervous system, and in vivo studies of acetylcholinesterase (AChE) have been carried out using many radiolabeled AChE inhibitors (donepezil, tacrine, physostigmine, CP-126,998, etc). Donepezil, a FDA approved drug for AD is now in clinical use. Therefore, we synthesized and evaluated p-[{sup 18}F]fluorodonepezil in mice. Biodistribution studies demonstrated that p-[{sup 18}F]fluorodonepezil binds non-specifically in vivo and does not suffer from metabolism in mouse brain. This study suggests that radioligands with higher binding affinity may be required to visualize AChE in vivo and further studies are needed to develop better radiotracers.

  1. Study on the metabolic peculiarities of renal radiotracer 99mTc-PAHIDA and diagnostic use

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Wang Liuyi; Lun Mingyue

    1994-11-01

    The metabolic peculiarities of renal radiotracer 99m Tc-PAHIDA and diagnostic use were studied. The results of the radioactive tracing study showed that 99m Tc-PAHIDA was distributed predominantly in kidney, and then in heart, gastrointestinal tract, liver, spleen, musculus quadriceps femoris, adipose tissue, testes and brain. It should be noted that when smaller dose of this agent was given, more 99m Tc-PAHIDA was concentrated in kidney and, at the same time, the level of its binding to plasma protein was lower. The experimental results indicated that 99m Tc-PAHIDA was rapidly excreted in urine. Autoradiochromatographic examination of the urine showed a single radioactive peak corresponding to the authentic 99m Tc-PAHIDA, indicating that 99m Tc-PAHIDA was excreted in the unchanged form. (3 tabs.)

  2. Radiotracer studies in cavernous marble at Kamathikhairy Dam site, Pench Project (Maharashtra)

    International Nuclear Information System (INIS)

    Nath, Ravendra; Mahajan, N.M.; Vaidya, S.D.

    1982-01-01

    Radiotracer studies with tritiated water at Pench Project site conclusively proved that the cavernous marble upstream of the saddle dam is continuous with the marble occuring near the spillway portion of the main dam and that there is fast subterranean flow of water through the cavernous marble here. It is also established that this marble band upstream of the dam is interconnected with the marble band occuring in the vicinity of Pali village about 3 km downstream of the dam. Though big unclogged subterranean channels do not seem to exist in this region, which might have resulted in heavy leakage from the impounded reservoir, yet the possibility of some leakage of the water through the cavernous marble cannot be ruled out, due to the interconnection of the marble occuring upstream of the dam with the downstream marble band. (author)

  3. Challenges in the development of dopamine D2- and D3-selective radiotracers for PET imaging studies.

    Science.gov (United States)

    Mach, Robert H; Luedtke, Robert R

    2018-03-01

    The dopamine D2-like receptors (ie, D2/3 receptors) have been the most extensively studied CNS receptor with Positron Emission Tomography (PET). The 3 different radiotracers that have been used in these studies are [ 11 C]raclopride, [ 18 F]fallypride, and [ 11 C]PHNO. Because these radiotracers have a high affinity for both dopamine D2 and D3 receptors, the density of dopamine receptors in the CNS is reported as the D2/3 binding potential, which reflects a measure of the density of both receptor subtypes. Although the development of D2- and D3-selective PET radiotracers has been an active area of research for many years, this by and large presents an unmet need in the area of translational PET imaging studies. This article discusses some of the challenges that have inhibited progress in this area of research and the current status of the development of subtype selective radiotracers for imaging D3 and D2 dopamine receptors with PET. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Radiotracer Applications in Wastewater Treatment Plants

    International Nuclear Information System (INIS)

    2011-01-01

    Wastewater containing pollutants resulting from municipal and industrial activities are normally collected in wastewater treatment plants (WWTPs) for processing before discharge to the environment. The WWTPs are the last barrier against contamination of downstream surface waters such as rivers, lakes and sea. Treated wastewater is reused for irrigation, particularly in arid and semi-arid countries. Therefore, it is very important to maintain optimal operating conditions of WWTPs to eliminate or reduce environmental pollution. Wastewater treatment plants are complicated systems, where the processes of mixing, separation, aeration, biological and chemical reactions occur. A WWTP is basically a multiphase system, and the efficiency of an installation strongly depends on liquid, solid and gas phase flow structures and their residence time distributions (RTDs). However, the fluid dynamic properties of such systems are not yet completely understood, rendering difficult the theoretical prediction of important process parameters such as flow rates, phase distributions, mixing and sediment characteristics. Tracer techniques are very useful tools to investigate the efficiency of purification in WWTPs, aiding both their design and performance optimization. There are many kinds of tracers. Radioactive tracers are the most sensitive and are largely used for on-line diagnosis of various operations in WWTPs. The success of radiotracer applications rests upon their extremely high detection sensitivity, and the strong resistance against severe process conditions. During the last few decades, many radiotracer studies have been conducted worldwide for investigation of various installations for wastewater treatment, such as mixer, aeration tank, clarifiers, digester, filter, wetland and oxidation units. Various radiotracer methods and techniques have been developed by individual tracer groups. However, the information necessary for the preservation of knowledge and transfer of

  5. Radiotracer studies of the adsorption of surface active substances at aqueous surfaces, 6

    International Nuclear Information System (INIS)

    Tajima, Kazuo

    1976-01-01

    The surface tension and adsorption were observed by the Wilhelmy plate and radiotracer methods at the air-solution interface of an aqueous solution of urea and α-dodecyl-ω-hydroxyhexa(oxyethylene) (D(EO) 6 ). The adsorption of D(EO) 6 was dependent on the concentration of urea below the CMC values, but above the values it was independent of the concentration. Urea adsorption occurs positively for low-surface packing of the poly(oxyethylene) group of D(EO) 6 , but negatively for the closest packing of the group and high concentrations of urea. It was confirmed that D(EO) 6 adsorption took place at the solution surface according to the Gibbs adsorption isotherm, which was taken into account as an activity coefficient in an empirical equation for the interactions of D(EO) 6 and urea in solution. Urea adsorption for the adsorbed monolayer of D(EO) 6 above the CMC value was interpreted assuming that urea, as for the nonionic micelle, was nonpenetrating, which was examined by gel permeation. (auth.)

  6. Studies of soils erosion in Protected Areas of Cienfuegos, Cuba, using Cesium - 137 as radiotracer

    International Nuclear Information System (INIS)

    Sibello Hernandez, Rita Y.; Febles Gonzalez, Jose M.

    2011-01-01

    The large-scale nuclear explosions that had taken place due to the nuclear weapons tests or as a result of nuclear accidents are the main causes of the great dispersion of artificial radionuclides around the world. One of these radionuclides is Cesium-137, which is strongly fixed to the fine soils particles. This fact, together with its half-life of 30 years and its easy detection by gamma spectrometry have converted Cesium-137, in a good radiotracer of the soils movement. This technique has been widely used and validated in different landscapes throughout the world. Its effectiveness was also previously validated and proved in Cienfuegos province too. This research was aimed at using the Cesium-137 technique to study soil redistribution and quantify erosion in the called Protected Areas in Cienfuegos province, where soil loss and sediment transport are the main causes of deterioration of these ecosystems with the consequent economic and / or environmental losses. The results were represented in a map using the software gvSIG by kriging, achieving greater visibility of the soil redistribution in the plot studied. The methodology used in this study can be used in other places wherever it is necessary to know the magnitude of the erosion problems and to know the soil redistribution pattern in the landscape which can be very useful to draw the plans for reorganization of land use.(author)

  7. The study of Cr(III) complexation in the xylem sap using ion exchange and radiotracer

    International Nuclear Information System (INIS)

    Juneja, Shikha; Prakash, Satya

    2003-01-01

    Radiotracer was employed to carry out ion exchange experiments to study the chromium speciation in the in vitro samples of xylem sap of maize stem of 60 days old plants. Cr(III) radiolabelled with its radioactive isotope ( 51 Cr) was mixed with both the ion exchange fraction of the sap which represented the carboxylic acids, as well as the whole sap and was analysed for complexation after 10 and 30 days at 25 degC. Prior to this, the ion exchange elution chromatography of Cr(III), and the Cr(III) complexes with oxalic and citric acid were used to compare the complexes being formed in the in vitro studies. The in vitro Cr(III) complexation results indicated that Cr(III) was vitally present as anionic species. The elution curve trend was similar to that of citric acid complexation. Citric acid was also found to be the major complexing acid in the xylem sap as determined by HPLC. The results indicate the transportation of Cr(III) as a citrate complex in the xylem sap of maize plants. (author)

  8. Study of technological parameters influence on homogeneity of rubber mixings by means of radiotracer methods

    International Nuclear Information System (INIS)

    Koczorowska, E.

    1995-01-01

    The radiotracer methods have been worked out for analysis of physico-chemical phenomena. The analysis were carried out for rubber mixings in technological conditions and played a deciding role for quality of manufacturing assortment. The 35 S and 65 Zn have been used as radiotracers. Analysis of different technological parameters influence on behaviour of soluble and polymerized sulfur, zinc compounds as well as other components of the rubber mixing enables to formulate the conclusions important for rubber industry and technology from view point of quality of manufacturing products

  9. Biosorptive behavior of mango (Mangifera indica) and neem (Azadirachta indica) barks for 134Cs from aqueous solutions. A radiotracer study

    International Nuclear Information System (INIS)

    Mishra, S.P.; Tiwari, D.; Prasad, S.K.; Dubey, R.S.; Mishra, M.

    2007-01-01

    The role of dead biomasses viz., mango (Mangifera indica) and neem (Azadirachta indica) bark samples are assessed in the removal behavior of, one of important fission fragments, Cs(I) from aqueous solutions employing a radiotracer technique. The batch type studies were carried out to obtain various physico-chemical data. It is to be noted that the increase in sorptive concentration (from 1.0 x 10 -8 to 1.0 x 10 -2 mol x dm -3 ), temperature (from 298 to 328 K) and pH (2.6 to 10.3) apparently favor the uptake of Cs(I) by these two bark samples. The concentration dependence data obeyed Freundlich adsorption isotherm and the uptake follows first order rate law. Thermodynamic data evaluation and desorption experiments reveal the adsorption to be irreversible and endothermic in nature proceeding through ion-exchange and surface complexation for both dead biomasses. Both bark samples showed a fairly good radiation stability in respect of adsorption uptake of Cs(I) when irradiated with a 300 mCi (Ra- Be) neutron source having an integral neutron flux of ∼ 3.85 x 10 6 n x cm -2 x s -1 and associated with a nominal γ-dose of ∼ 1.72 Gy x h -1 . (author)

  10. Synthesis of new radiotracers

    International Nuclear Information System (INIS)

    Chahed, Ahlem

    2008-01-01

    The brain's sensibility besides to the rigorous selectivity of changes taking place on brain's barriers leads us to synthesis specifics radiotracers based on diamine ethylene and marked with technetium radioisotope to form a radiotracer able to pass these barriers and diagnose illnesses in an early stage. These radiotracers are tested by a biodistribution on a small animal to be ratified. (Author)

  11. Radiotracer technique to study pollutant behavior in the vadose zone for groundwater protection

    International Nuclear Information System (INIS)

    Kulkarni, U.P.; Sinha, U.K.; Navada, S.V.; Datta, P.S.; Sud, Y.K.; Kulkarni, K.M.; Aggrawal, P.; )

    2004-01-01

    Pollutants are generated either by industrial or agricultural activity. Pollutants produced due to industrial activities fall into point source category and those generated from agricultural are grouped into extended source category. Under an International Atomic Energy Agency/Coordinated Research Program study, emphasis has been given on transport of pollutants, generated from agricultural activities, in particular, due to the application of fertilizer inputs to a variety of crops. Pollutants take entry through the vadose zone and ultimately join the saturated zone. Once groundwater is polluted it is rather difficult or impossible to take remedial measures for groundwater protection. Groundwater being an important natural resource, it is important to protect it from getting polluted. It is hence essential to have a clear understanding of the complex processes (physical, biological and chemical etc.) undergoing in the unsaturated zone. Radiotracers give good insight about the pollutant behavior in the vadose zone. Tritiated water and 60 Co (a gamma emitting tracer in the cyanide complex form) were used as tracers and were injected at 60 cm depth in the vadose zone of IARI farm for pollutant transport study. Tritium and 60 Co tracer displacements were measured by liquid scintillation and sodium iodide scintillation method respectively. It was found that the tritium tracer moved up to 2.4 meters in six months and part of the tritium tracer was exchanged with immobile water in the soil, as three distinct peaks were observed in tritium profile. 60 Co and tritium tracers were found to move with the same velocity in the vadose zone. These tracer studies indicate that the pollutants may reach the groundwater in about three years. (author)

  12. Radiotracer study on the efficiency of a cylindrical 2-stage anaerobic sludge digester

    International Nuclear Information System (INIS)

    Sung-Hee Jung; Joon-Ha Jin; Jong-Bum Kim

    2004-01-01

    Radiotracer experiments were carried out on a cylindrical 2-stage anaerobic sludge digester in order to investigate the improvement of their efficiency by means of RTD (residence time distribution) measurements before and after cleaning up the inside of the digester. The tracer was scandium in an EDTA solution which forms such a stable complex compound to keep the isotope form being adsorbed onto the surface of the pipelines or the wall. It was injected into the digester by pressurized nitrogen gas and its movement was monitored by NaI(Tl) scintillation detectors installed around the digester and recorded for a month by a 24-channel data acquisition system specially developed for radiotracer experiments by the Korea Tracer Group of KAERI. The experimental data was analysed for the MRT (mean residence time) and other parameters characterizing the flow behaviour. (author)

  13. Applied radiotracer techniques for studying pollutant bioaccumulation in selected marine organisms (jellyfish, crabs and sea stars)

    International Nuclear Information System (INIS)

    Fowler, S.W.; Teyssie, J.-L.; Cotret, O.; Danis, B.; Warnau, M.; Rouleau, C.

    2004-01-01

    Obtaining specific information on contaminant biokinetics in marine biota is often necessary for properly interpreting monitoring data on trace contaminant levels in bioindicator species living under varying environmental conditions. Radiotracers have been employed in laboratory experiments to assess the uptake, distribution and retention of selected heavy metals and PCB congeners in three potential marine bioindicators occupying different ecological niches in the coastal zone. Pelagic and benthic jellyfish readily accumulated Co, Ag, Zn, Cd, 137 Cs and 241 Am from both water and food and retained them with biological half-lives (Tb1/2) ranging from a few days to several weeks. Zinc and silver were accumulated to the greatest degree (CF ∼ 4 · 10 2 ), with benthic jellyfish having a greater affinity for metals than the pelagic species. Results from light-dark experiments indicate that the enhanced metal uptake in the benthic jellyfish is due to the presence of endosymbiotic photosynthetic zooxanthellae situated in the arms of organisms. Shore crabs ingesting Ag, a sewage-related contaminant, readily accumulated the metal with male crabs assimilating some 71% and female crabs 51% of the Ag from their food. Moreover, the assimilated fraction of Ag remained virtually immobile in their tissues as evidenced by an extremely long Tb1/2 for depuration of 7.3 years. Sea stars exposed to 14 C-labelled PCB congener no. 153 in sea water accumulated the congener mainly in the body wall and podia reaching lipid weight CFs that ranged between approximately 2 · 10 5 to 4 · 10 5 . In contrast, following exposure in radiolabelled sediments, the corresponding PCB transfer factors in the same tissues were much lower, viz., 3 · 10 2 to 5 · 10 2 . Nevertheless, regardless of the exposure mode, CFs of PCB in the other tissues (digestive system, gonads, pyloric and rectal caeca) were consistently one to two orders of magnitude lower, an observation which suggests that sea star body

  14. Sulfur and Iron Cycling in a Coastal Sediment - Radiotracer Studies and Seasonal Dynamics

    DEFF Research Database (Denmark)

    MOESLUND, L.; THAMDRUP, B.; JØRGENSEN, BB

    1994-01-01

    to 2 mm in the oxidized surface layer of the sediment. The radiotracer data were analyzed by a mathematical model which showed that, due to partial, rapid reoxidation of radioactive sulfide during incubation, the actual reduction rates in this layer were probably underestimated 5-fold. In the deeper......, sulfidic zone, measured rates appeared to be correct. Sulfate reduction followed the seasonal variation in temperature with maximum activity at 1-2 cm depth in late summer. In spite of its rapid production, free H2S was detectable in the porewater only below the depth of free Fe2+ at 6-7 cm throughout...

  15. Study of water flowrate using time transient and cross-correlation techniques with 82Br radiotracer

    International Nuclear Information System (INIS)

    Salgado, William L.; Brandao, Luiz E.B.

    2013-01-01

    This paper aims to determinate the water flowrate using Time Transient and Cross-Correlation techniques. The detection system uses two NaI (T1) detectors adequately positioned on the outside of pipe and a gamma-ray source ( 82 Br radiotracer). The water flowrate measurements using Time Transient and Cross-Correlation techniques were compared to invasive conventional measurements of the flowrate previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowmeter previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowrate values were found to be less than 3% in relation to conventional ones. (author)

  16. Studies on sorption of cadmium (II) ions onto Haro river sand from aqueous media using radiotracer and voltammetric techniques

    International Nuclear Information System (INIS)

    Ahmed, R.; Hasany, S.M.; Yamin, T.; Ansari, M.S.

    2006-01-01

    Sorption of Cd(II) ions on Haro river sand has been studied using radiotracer technique. The effects of pH and acid concentrations on the sorption were studied. The sorption increases with pH. reaches a maximum at pH 7 and decreases at higher pH values. With acids, it was found that sorption decreases with increasing acid concentration, and for more oxidizing acids sorption was less. Kinetic studies indicate that mostly intra particle diffusion occurs with first order rate constant of 18.45 x 10 -2 min -1 . The sorption data follow the Freundlich and Dubinin-Radushkevich (D-R) isotherms. In addition to the radiotracer method, voltammetric technique was applied and the results by the two techniques are in good agreement. The sorption free energy value indicates that adsorption process is chemisorption. The effect of temperature was studied and values of ΔH, ΔS and ΔG for Cd(II) have been calculated which are 20.15 kJ mol -1 , 74.04 J mol -1 K -1 and -1.754 kJ mol -1 . Adsorption of Cd(II) on Haro river sand is endothermic, spontaneous and entropy driven. The effect of different anions and cations at different concentrations was studied. Levels of cadmium have been monitored in water and sediments. (orig.)

  17. Radiotracer Generators for Industrial Applications

    International Nuclear Information System (INIS)

    2013-01-01

    Radiotracers have been widely used throughout industry to optimize processes, solve problems, improve product quality, save energy and reduce pollution. Their technical, economic and environmental benefits have been recognized by both the industrial and the environmental sectors. The most important radiotracer techniques have been transferred to many developing Member States through IAEA Technical Cooperation projects. However, in spite of their manifest benefits, radiotracer techniques continue to be underutilized, not only by developing countries but also by more industrialized nations. There are a number of factors that restrict the usage of the radioisotope techniques, but chief among them is the timely availability of suitable radiotracers. Ensuring timely availability of suitable radionuclides is a main hurdle to the use of radiotracer techniques in industry. For developing countries that do not possess radioisotope production facilities, the long time required for import of radionuclides not only completely rules out the use of short half-life nuclides, but also makes it impossible for the radioisotope applications teams to respond to problems of an urgent nature. Many possible radiotracer investigations are not being carried out in developing countries because of this problem. Even in industrialized countries, radionuclide supply is often a problem, as many of the former suppliers of industrial radionuclides have switched their production facilities to serve the more lucrative radiopharmaceuticals market. Obtaining continuity of supply of radionuclides with which to carry out extended studies in difficult-to-access locations, such as offshore oil platforms, is also a significant challenge. Making use of tracers from radionuclide generators can alleviate the difficulties associated with radioisotope supply. Two commercially available medical radionuclide generators, 99 Mo/ 99 mTc and 113 Sn/ 113 mIn, have been used for this purpose, but their use has been

  18. Radiotracer technique to study movement of pollutants in an alluvial aquifer

    International Nuclear Information System (INIS)

    Kulkarni, U.P.; Sharma, Suman

    2001-01-01

    Radioisotopes are being used as tracers in many research areas. Their use in determination of groundwater flow velocity is well known. They also provide insight into the understanding the hydrological systems. In this paper, pollutant movement in an alluvial aquifer in the Ganga basin near Kanpur is evaluated using radiotracer method. Radioactive 82 Br in the form of aqueous ammonium bromide was used as a tracer to measure filtration velocity of the groundwater in the vicinity of an effluent storage lagoon of a fertilizer plant at Kanpur, U.P. Point dilution technique in a single well was applied. Filtration velocity so obtained provided relevant information about the pollutant movement in the groundwater. (author)

  19. Radiotracer method for residence time distribution study in multiphase flow system

    International Nuclear Information System (INIS)

    Sugiharto, S.; Su'ud, Z.; Kurniadi, R.; Wibisono, W.; Abidin, Z.

    2009-01-01

    [ 131 I] isotope in different chemical compounds have been injected into 24 in hydrocarbon transmission pipeline containing approximately 95% water, 3% crude oil, 2% gas and negligible solid material, respectively. The system is operated at the temperature around 70 deg. C enabling fluids flow is easier in the pipeline. The segment of measurement was chosen far from the junction point of the pipeline, therefore, it was reasonably to assume that the fluids in such multiphase system were separated distinctively. Expandable tubing of injector was used to ensure that the isotopes were injected at the proper place in the sense that [ 131 I]Na isotope was injected into water layer and iodo-benzene, [131] IC 6 H 5, was injected into crude oil regime. The radiotracer selection was based on the compatibility of radiotracer with each of fluids under investigation. [ 131 I]Na was used for measuring flow of water while iodo-benzene, [131] IC 6 H 5, was used for measuring flow of crude oil. Two scintillation detectors were used and they are put at the distances 80 and 100 m, respectively, from injection point. The residence time distribution data were utilized for calculation water and crude oil flows. Several injections were conducted in the experiments. Although the crude oil density is lighter than the density of water, the result of measurement shows that the water flow is faster than the crude oil flow. As the system is water-dominated, water may act as carrier and the movement of crude oil is slowed due to friction between crude oil with water and crude oil with gas at top layer. Above of all, this result was able to give answer on the question why crude oil always arrives behind water as it is checked at gathering station. In addition, the flow patterns of the water in the pipeline calculated by Reynolds number and predicted by simple tank-in-series model is turbulence in character.

  20. Special aspects of the indirect radiotracer technique when used to study the adsorption and electrochemical reactions of organic substances at solid electrodes

    International Nuclear Information System (INIS)

    Andreev, V.N.; Horanyi, G.; Kazarinov, V.E.

    1986-01-01

    This paper analyzes the possibilities and special aspects of the indirect radiotracer technique with a number of examples. Data are presented concerning the effects of acetic and oxalic acid on chloride ion adsorption on platinized platinum electrodes at a potential E = 0.2 V. The effect on chloride ion adsorption is much larger in the case of oxalic acid, which is evidence for its higher adsorbability on platinum at E = 0.2 V. It is shown that the indirect radiotracer technique offers significant possibilities for studying the electrochemical properties of adsorption products of organic substances

  1. Novel methodology for the study of mercury methylation and reduction in sediments and water using 197Hg radiotracer

    International Nuclear Information System (INIS)

    Ribeiro Guevara, Sergio; Perez Catan, Soledad; Zizek, Suzana; Repinc, Urska; Jacimovic, Radojko; Horvat, Milena

    2007-01-01

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H 2 SO 4 or HCl were evaluated in freshwater sediments using 197 Hg radiotracer. Values obtained for the 197 Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of 197 Hg 2+ into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg 2+ contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg 2+ contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H 2 SO 4 method is recommended, since it is free from these interferences. 197 Hg radiotracer (T 1/2 = 2.673 d) has a production rate that is about 50 times higher than that of 203 Hg (T 1/2 46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to 203 Hg when it is used it in short-term experiments and produced by the irradiation of 196 Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the 196 Hg isotope is increased, the specific activity of the 197 Hg tracer can be significantly improved. In the present work, 197 Hg tracer was produced from mercury 51.58% enriched in the 196 Hg

  2. Study on the metabolic peculiarities of renal radiotracer {sup 99m}Tc-PAHIDA and diagnostic use

    Energy Technology Data Exchange (ETDEWEB)

    Shoupeng, Zhu; Liuyi, Wang; Mingyue, Lun [Suzhou Medical Coll., JS (China)

    1994-11-01

    The metabolic peculiarities of renal radiotracer {sup 99m}Tc-PAHIDA and diagnostic use were studied. The results of the radioactive tracing study showed that {sup 99m}Tc-PAHIDA was distributed predominantly in kidney, and then in heart, gastrointestinal tract, liver, spleen, musculus quadriceps femoris, adipose tissue, testes and brain. It should be noted that when smaller dose of this agent was given, more {sup 99m}Tc-PAHIDA was concentrated in kidney and, at the same time, the level of its binding to plasma protein was lower. The experimental results indicated that {sup 99m}Tc-PAHIDA was rapidly excreted in urine. Autoradiochromatographic examination of the urine showed a single radioactive peak corresponding to the authentic {sup 99m}Tc-PAHIDA, indicating that {sup 99m}Tc-PAHIDA was excreted in the unchanged form. (3 tabs.).

  3. Study of a new hepatobiliary radiotracer: sup(99m)Tc diethyl IDA. Its value in the diagnosis of cholestasis

    International Nuclear Information System (INIS)

    Roques, J.F.

    1979-01-01

    This work examines a new means of investigation: Technetium 99 (2,6 diethyl acetanilido) imino-diacetic acid, or HEPATOBIDA, hepatobiliary scintigraphy. A survey of different scintigraphic techniques is necessary. At first the kinetic study of hepatobiliary radiotracers was carried out with multiprobe systems giving quantitative information on the various organs or pools concerned. With the appearance of the scintillation camera it became possible to obtain not only quantitative data but also topographical and morphological information. Since 1976 the derivatives of iminodiacetic acid have been widely adopted, possessing features most closely resembling those of the ideal hepatobiliatropic molecules. Examinations have been performed at the Angers Radioisotopes Service with the diethyl derivative or HEPATOBIDA (Nuclear Solca Lab.) The results recorded in a group of cholestasis patients are studied, with normal data supplied by a set of 8 reference subjects free from hepatobiliary diseases [fr

  4. Development of Radiotracer Techniques in Industry

    International Nuclear Information System (INIS)

    Wardono

    2000-01-01

    Contribution of radiotracer techniques to solve problems in industrial process plants have been recognized since a long time. Radiotracer application was governed by three main components, namely radioisotopes, radiation detection and data interpretation of an experiment. The three main components mentioned above have been continually developed to overcome problems relating to the operation of industrial process plants. The availability of isotope generator is one of the development aspect in radiotracer technique. Radiation hazard in radiotracer experiment may be reduced by applying isotope generator and on the other hand the delivery of radiotracer to the plant site from the radioisotopes producer was made easier. The development of microprocessor in computer system has facilitated data recording, storing and retrieving. Development in mathematical model supported by radiotracer experiment enhance data interpretation and shed light on various phenomena of flow process. Generally a flow dynamic in a process plant in all kind of industries can be studied using radiotracer technique. However the main challenge coming from petroleum, petrochemical and mineral processing industries

  5. Development and applications of radiotracers technologies and gamma scanning

    International Nuclear Information System (INIS)

    Conejo, Mario; Chaverri, Oscar; Chine, Bruno; Vargas, Celso

    2008-01-01

    The radiotracers and gamma scanning technologies are very consolidated tools for studying, analyzing and evaluating of industrial processes. The development and the results of radiotracers and gamma scanning technologies applied in laboratory and more complex systems, are reported. The radiotracers technology was used to study boron diffusion during the curing process of the wood, to evaluate a lagoon of sewage treatment with aquatic iris plants and to carry out experimental work with controlled variables in a laboratory hydraulic circuit (flow rig). The gamma scanning technique was used to analyze a pilot tower in the laboratories. The main results achieved with the experiments were the following: 1) the boron absorption as a wood curing agent depends on the section of wood exposed to the curing solution; 2) during the tests effectuated with Iodine 131, the aquatic iris plants situated in the water treatment lagoon absorb part of the radiotracer, making difficult the residence time determination; 3) the sensibility of the system Cesium 137 source and detector is sufficiently high and can detect low radioactive absorption materials, situated inside columns with steel walls. (author) [es

  6. Radiotracers for medical applications

    International Nuclear Information System (INIS)

    Rayudu, G.A.S.

    1983-01-01

    This book discusses the medical applications of radiotracers. Diagnostic uses and pharmacokinetics of isotopes and radiopharmaceuticals is emphasized. The volume one covers the following topics: Radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; /sup 11/C, /sup 13/N, /sup 15/O, /sup 67/Ga. /sup 111/In, /sup 75/Se, /sup 123m/Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented. 272 pp., 7 x 10, 1983, ISBN-0-8493-6016-1

  7. Synthesis of new technetium brain radiotracers

    International Nuclear Information System (INIS)

    Ben Dhieb, Fatma

    2012-01-01

    The scintigraphic diagnosis is a major mean for detecting neuro degenerative diseases at early stage; this requires specific radiotracers to a particular class of brain receptors. Our goal was the synthesis of radiotracers, cytectrenes derivatives, which are specific to the 5-HT1A receptor, whose dysfunction is an indicator of neuro degeneration. The study of their biodistribution revealed for only one of them, a good brain retention and a retrieval adequate for diagnosis.

  8. Simulation study on the measurements of diffusion coefficients in solid materials by short-lived radiotracer beams

    CERN Document Server

    Jeong, S C; Kawakami, H

    2003-01-01

    We have examined, by a computer simulation, an on-line measurement of diffusion coefficients by using a short-lived alpha particle emitter, sup 8 Li (half life of 0.84s), as a radiotracer. The energy spectra of alpha particles emitted from diffusing sup 8 Li primarily implanted in the sample of LiAl ar simulated as a measure of the diffusion of sup 8 Li in the sample. As a possible time sequence for the measurement, a time cycle of 6s, i.e. the implantation of sup 8 Li for 1.5s and subsequent diffusion for 4.5s, is supposed. The sample is primarily set on a given temperature for the measurement. The time-dependent yields of alpha particles during the time cycle reveal the possibility to measure the diffusion coefficient with an accuracy of 10% if larger than 1 x 10 sup - sup 9 cm sup 2 /s, by the comparison with the experimental spectra measured at the temperature, i.e. at a certain diffusion coefficient. (author)

  9. Studies on the electrochemical behaviour of iron by the use of radio-tracer technique, 1. Studies on the electrodeposition and dissolution of iron by the use of radio-tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Moritani, Kimikazu; Ito, Yasuhiko; Kamata, Masahiro; Oishi, Jun

    1984-12-01

    To investigate whether radio-tracer techniques can augment conventional electrochemical techniques, offering useful information about the electrochemical behaviour of iron, the current efficiency of the electrodeposition of iron and the corrosion rate of metallic iron were measured by the radio-tracer method and the results were compared with the results measured by gravimetry and absorption photometry. Major conclusions obtained by the experiments are summarized as: 1) Between ordinary Fe and /sup 59/Fe, no isotope effect was observed. 2) Radiation from /sup 59/Fe had no effect on the electrode reaction. 3) While the use of a Ge semiconductor detector is undoubtedly preferable, Geiger-Mueller counter or NaI(Tl) scintillation counter gave fully satisfactory results. 4) Electrodeposited iron corrodes several times more rapidly than the iron base metal. These results suggests many other interesting applications of the radio-tracer technique when it is desired to obtain more detailed information on the electrochemical behaviour of iron. (author).

  10. Novel methodology for the study of mercury methylation and reduction in sediments and water using {sup 197}Hg radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Guevara, Sergio; Perez Catan, Soledad [Centro Atomico Bariloche, Laboratorio de Analisis por Activacion Neutronica, Bariloche (Argentina); Zizek, Suzana; Repinc, Urska; Jacimovic, Radojko; Horvat, Milena [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia)

    2007-03-15

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H{sub 2}SO{sub 4} or HCl were evaluated in freshwater sediments using {sup 197}Hg radiotracer. Values obtained for the {sup 197}Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of {sup 197}Hg{sup 2+} into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg{sup 2+} contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg{sup 2+} contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H{sub 2}SO{sub 4} method is recommended, since it is free from these interferences. {sup 197}Hg radiotracer (T{sub 1/2} = 2.673 d) has a production rate that is about 50 times higher than that of {sup 203}Hg (T{sub 1/2} = 46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to {sup 203}Hg when it is used it in short-term experiments and produced by the irradiation of {sup 196}Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the {sup 196}Hg isotope is increased, the specific activity of the {sup 197}Hg tracer can be significantly improved. In

  11. Novel methodology for the study of mercury methylation and reduction in sediments and water using 197Hg radiotracer.

    Science.gov (United States)

    Ribeiro Guevara, Sergio; Zizek, Suzana; Repinc, Urska; Pérez Catán, Soledad; Jaćimović, Radojko; Horvat, Milena

    2007-03-01

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H2SO4 or HCl were evaluated in freshwater sediments using 197Hg radiotracer. Values obtained for the 197Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of 197Hg2+ into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg2+ contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg2+ contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H2SO4 method is recommended, since it is free from these interferences. 197Hg radiotracer (T1/2=2.673 d) has a production rate that is about 50 times higher than that of 203Hg (T1/2=46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to 203Hg when it is used it in short-term experiments and produced by the irradiation of 196Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the 196Hg isotope is increased, the specific activity of the 197Hg tracer can be significantly improved. In the present work, 197Hg tracer was produced from mercury 51.58% enriched in the 196Hg isotope, and a 340-fold

  12. Radiotracers in the study of marine food chains. The use of compartmental analysis and analog modelling in measuring utilization rates of particulate organic matter by benthic invertebrates

    International Nuclear Information System (INIS)

    Gremare, A.; Amouroux, J.M.; Charles, F.

    1991-01-01

    The present study assesses the problem of recycling when using radiotracers to quantify ingestion and assimilation rates of particulate organic matter by benthic invertebrates. The rapid production of dissolved organic matter and its subsequent utilization by benthic invertebrates constitutes a major bias in this kind of study. However recycling processes may also concern POM through the production and reingestion of faeces. The present paper shows that compartmental analysis of the diffusion kinetics of the radiotracer between the different compartments of the system studied and the analog modelling of the exchanges of radioactivity between compartments may be used in order to determine ingestion and assimilation rates. This method is illustrated by the study of a system composed of the bacteria Lactobacillus sp. and the filter-feeding bivalve Venerupis decussata. The advantages and drawbacks of this approach relative to other existing methods are briefly discussed. (Author)

  13. Utility of radiotracer methodology in scientific research of industrial relevancy

    International Nuclear Information System (INIS)

    Kolar, Z.I.

    1990-01-01

    Utilization of radiotracer methodology in industrial research provides substantial scientific rather than directly demonstrable economic benefits. These benefits include better understanding of industrial processes and subsequently the development of new ones. Examples are given of the use of radiotracers in technological studies and the significance of the obtained results is put down. Creative application of radiotracer methodology may contribute to the economic development and technological advancement of all countries including the developing ones. (orig.) [de

  14. Some Examples of Residence-Time Distribution Studies in Large-Scale Chemical Processes by Using Radiotracer Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bullock, R. M.; Johnson, P.; Whiston, J. [Imperial Chemical Industries Ltd., Billingham, Co., Durham (United Kingdom)

    1967-06-15

    The application of radiotracers to determine flow patterns in chemical processes is discussed with particular reference to the derivation of design data from model reactors for translation to large-scale units, the study of operating efficiency and design attainment in established plant and the rapid identification of various types of process malfunction. The requirements governing the selection of tracers for various types of media are considered and an example is given of the testing of the behaviour of a typical tracer before use in a particular large-scale process operating at 250 atm and 200 Degree-Sign C. Information which may be derived from flow patterns is discussed including the determination of mixing parameters, gas hold-up in gas/liquid reactions and the detection of channelling and stagnant regions. Practical results and their interpretation are given in relation to an define hydroformylation reaction system, a process for the conversion of propylene to isopropanol, a moving bed catalyst system for the isomerization of xylenes and a three-stage gas-liquid reaction system. The use of mean residence-time data for the detection of leakage between reaction vessels and a heat interchanger system is given as an example of the identification of process malfunction. (author)

  15. Automated PET Radiotracer Manufacture on the BG75 System and Imaging Validation Studies of [18F]fluoromisonidazole ([18F]FMISO).

    Science.gov (United States)

    Yuan, Hong; Frank, Jonathan E; Merrill, Joseph R; Hillesheim, Daniel A; Khachaturian, Mark H; Anzellotti, Atilio I

    2016-01-01

    The hypoxia PET tracer, 1-[18F]fluoro-3-(2-nitro-1Himidazol- 1-yl)-propan-2-ol ([18F]FMISO) is the first radiotracer developed for hypoxia PET imaging and has shown promising for cancer diagnosis and prognosis. However, access to [18F]FMISO radiotracer is limited due to the needed cyclotron and radiochemistry expertise. The study aimed to develop the automated production method on the [18F]FMISO radiotracer with the novel fully automated platform of the BG75 system and validate its usage on animal tumor models. [18F]FMISO was produced with the dose synthesis cartridge automatically on the BG75 system. Validation of [18F]FMISO hypoxia imaging functionality was conducted on two tumor mouse models (FaDu/U87 tumor). The distribution of [18F]FMISO within tumor was further validated by the standard hypoxia marker EF5. The average radiochemical purity was (99±1) % and the average pH was 5.5±0.2 with other quality attributes passing standard criteria (n=12). Overall biodistribution for [18F]FMISO in both tumor models was consistent with reported studies where bladder and large intestines presented highest activity at 90 min post injection. High spatial correlation was found between [18F]FMISO autoradiography and EF5 hypoxia staining, indicating high hypoxia specificity of [18MF]FMISO. This study shows that qualified [18F]FMISO can be efficiently produced on the BG75 system in an automated "dose-on-demand" mode using single dose disposable cards. The possibilities of having a low-cost, automated system manufacturing ([18F]Fluoride production + synthesis + QC) different radiotracers will greatly enhance the potential for PET technology to reach new geographical areas and underserved patient populations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Radiotracer properties determined by high performance liquid chromatography: a potential tool for brain radiotracer discovery

    International Nuclear Information System (INIS)

    Tavares, Adriana Alexandre S.; Lewsey, James; Dewar, Deborah; Pimlott, Sally L.

    2012-01-01

    Introduction: Previously, development of novel brain radiotracers has largely relied on simple screening tools. Improved selection methods at the early stages of radiotracer discovery and an increased understanding of the relationships between in vitro physicochemical and in vivo radiotracer properties are needed. We investigated if high performance liquid chromatography (HPLC) methodologies could provide criteria for lead candidate selection by comparing HPLC measurements with radiotracer properties in humans. Methods: Ten molecules, previously used as radiotracers in humans, were analysed to obtain the following measures: partition coefficient (Log P); permeability (P m ); percentage of plasma protein binding (%PPB); and membrane partition coefficient (K m ). Relationships between brain entry measurements (Log P, P m and %PPB) and in vivo brain percentage injected dose (%ID); and K m and specific binding in vivo (BP ND ) were investigated. Log P values obtained using in silico packages and flask methods were compared with Log P values obtained using HPLC. Results: The modelled associations with %ID were stronger for %PPB (r 2 =0.65) and P m (r 2 =0.77) than for Log P (r 2 =0.47) while 86% of BP ND variance was explained by K m . Log P values were variable dependant on the methodology used. Conclusions: Log P should not be relied upon as a predictor of blood-brain barrier penetration during brain radiotracer discovery. HPLC measurements of permeability, %PPB and membrane interactions may be potentially useful in predicting in vivo performance and hence allow evaluation and ranking of compound libraries for the selection of lead radiotracer candidates at early stages of radiotracer discovery.

  17. UV-photochemical vapor generation of selenium for atomic absorption spectrometry: Optimization and 75Se radiotracer efficiency study

    Czech Academy of Sciences Publication Activity Database

    Rybínová, M.; Musil, Stanislav; Červený, J.; Vobecký, Miloslav; Rychlovský, P.

    2016-01-01

    Roč. 123, SEP (2016), s. 134-142 ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : UV-photochemical vapor generation * Selenium * 75Se radiotracer Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.241, year: 2016

  18. Absorption and retention studies of trace elements and minerals in rats using radiotracers and whole-body counting

    NARCIS (Netherlands)

    Berg, van den G.J.; Wolterbeek, H.Th.; de Goeij, J.J.M.; Beynen, A.C.

    1995-01-01

    A description is given of a whole-body counting technique using radiotracers, permitting the determination of true absorption and endogenous excretion of trace elements and minerals in the rat in vivo. This non-invasive counting method involves oral and intraperitoneal administration of tracer doses

  19. Development of equipment and radiotracer experiment using RI labelled sand in the coastal zone

    International Nuclear Information System (INIS)

    Choi, B. J.; Jung, S. H.; Kim, J. B.; Jin, J. H.

    2004-01-01

    On the basis of the radiotracer technology and the related equipments which have been developed for its industrial application through the nuclear long-term research project, a radiotracer study on sediment transport was carried out as a part of the development of the radiotracer technology for a coastal marine environment. The crystalline material doped with iridium having a similar composition and density as those of the bedload sand collected from the research area was produced by the oxide-route method. A radioisotope container was specially designed to inject the radiotracer from 1m above the sea bedload without radioactive contamination during the transport from the nuclear reactor at KAERI. The position data from the DGPS and the radiation measurement data are collected concurrently and stored by means of the application software programmed with the LabVIEW of the National Instrument. The position data is reprocessed to make it represent the real position of the radiation probe under water and not that of the DGPS antenna on board. In order to evaluate the influence of a breakwater on the deviation of the neighboring coastline, the time dependency of the spatial distribution of the sediment was studied in the area through three tracking measurements after the iridium glass was injected. This trial application showed the potential of the radiotracer technology as an important role for maintaining and developing the coastal marine environment in the future

  20. Radiotracers inside the system

    International Nuclear Information System (INIS)

    Savio, Eduardo

    2000-01-01

    The radioactive use of a tracer that you incorporated in a biological, physical or chemicals system can be an indicator of some of the following situations: of the system in general, of a property that is wanted to evaluate, of a biochemical, physiological or pathophysiological. One the radiotracers use inside the system presents the following advantages: 1. it is possible to detect them and to measure them with high precision and sensibility, 2. the radioactivity is independent of the pressure, the temperature, the physical or chemical state 3. the radiotracers do affect the system and they can be used as non destructive methods 4. In most of the cases they can be measured in independent form of the matrix, without necessity of a calibration curve

  1. Radiotracer injections through microfilters

    International Nuclear Information System (INIS)

    Huber, H.; Maschek, G.; Pichler, R.; Giesen, I.; Hatzl-Griesenhofer, M.; Maschek, W.

    2002-01-01

    Full text: Problems with the injection of radiotracers ( 99m Tc-HAMS, 99m Tc-DPD) to infants when administered through polar-filter-protected venous pathways caused us to get a closer look of what happens to a tracer in such a system. We simulated injections of the tracers mainly used at our institution in an in-vitro array and measured full and empty tracer syringes, filters (0.2 μm micropores) and the post-filter receptacle of the radioactivity. We calculated the percentage of filter-trapped activity and of activity in the receptacle. For several tracers we repeated this process with a neutral filter of the same pore size to get a comparison between the behavior in polarized and electrically inert filters. In general injection of a soluble radiotracer through a polar filter system means a dose loss in the filter of about 10 %, up to the tracer molecule size of IgG-antibodies. Suspended tracers, which consist of comparatively large particles, like RES- or pulmonary perfusion markers, are blocked by the filter, as can be foreseen with a particle size of >> 0.2 μm. DMSA and DPD (a biphosphonate), although both being soluble and rather small molecules, were blocked by the polar filter to a high extent, and by the neutral filter to a much lower, almost neglectable degree. The conclusions are: if possible avoid any use of a filter in your tracer injection pathway. Never use a filter with bone scan or DMSA applications. When doing uptake calculations you have to add the filter counts to the empty syringe value in the formula. If you cannot avoid to inject the radiotracer through a filter you have to replace the filter afterwards and treat the used filter as radioactive waste. The polarity of the filter material might severely affect retention of radiotracer in the filter. (author)

  2. Synthesis of new radiotracers based on aniline

    International Nuclear Information System (INIS)

    Ayari, Issra

    2008-01-01

    There are several possible applications of radioactivity, we cite: the study of the functional and neurochirnical aspects related to the brain. This study requires the synthesis of specific radiotracers able to cross their target tissue. The synthesis methods need to be constantly updated to respond to the big demand of this domain. The development of the chemistry of metal complexes helped us to find a stable radiotracer based on aniline and marked with technetium. This stability aI 10wed us to realize a possible biodistribution and to envisage to count the radioactivity and to valid the radiopharmaceutical. (Author)

  3. Radiotracer technique for studying the fate of methyl parathion in desert locust

    International Nuclear Information System (INIS)

    Garg, A.K.; Sethi, G.R.; Bhatia, Parvathy

    1988-01-01

    The present study, using 14 C-labelled methyl parathion was intended for standardising the procedure of analysis of the insecticide and its metabolites in the desert locust, Schistocerca gregaria Forskal. (author). 5 refs

  4. Lead-210 as a radiotracer of coastal processes in studies along the Brazil coastal

    International Nuclear Information System (INIS)

    Patchineelam, Sambasiva R.; Sanders, Christian J.; Smoak, Joseph M.

    2013-01-01

    In this work, we review environmental radioactivity studies, using 210 Pb, over the past 15 years along various areas of the Brazilian Coast. Included in these studies sediment accumulation rates, mixing zones, atmospheric fallout, sediment focusing and boundary scavenging have been studied. To validate, our 210 Pb geochronologies, we have measured artificially fallout nuclides such as 137 Cs, 239+240 Pu and recorded pollution records, such as with heavy metals, with known mining history and have been used to confirm our 210 Pb geochronologies. Activities reported are also in agreement with duplicate analyses taken at the USGS geochemistry laboratory. Sedimentary deposit in mangrove of the Ilha Grande have been compared with near by tide gauge record. Result indicated the accretion rates are keeping pace with sea level rise. This relation, between 210 Pb sediment accumulation rates at local sea level rise, has proven to be important in area where tide gauges are not available to determine local sea level rise

  5. [18F]Fallypride: Metabolism studies and quantification of the radiotracer and its radiometabolites in plasma using a simple and rapid solid-phase extraction method

    International Nuclear Information System (INIS)

    Peyronneau, Marie-Anne; Saba, Wadad; Goutal, Sébastien; Kuhnast, Bertrand; Dollé, Frédéric; Bottlaender, Michel; Valette, Héric

    2013-01-01

    Introduction: [ 18 F]Fallypride, a fluorinated and substituted benzamide with high affinity for D 2 /D 3 receptors, is a useful PET radioligand for the study of striatal/extrastriatal areas. Since [ 18 F]fallypride is extensively metabolized in vivo and since PET examinations are long lasting in humans, the rapid measurement of the unchanged radiotracer in plasma is essential for the quantification of images. The present study aims: i) to evaluate if the radiometabolites of [ 18 F]fallypride cross the blood–brain barrier in rodents, ii) to identify these radiometabolites in baboon plasma and iii) to develop a rapid solid phase extraction method (SPE) suitable for human applications to quantify both [ 18 F]fallypride and its radiometabolites in plasma. Methods: The metabolites P450-dependant in rat and human liver microsomes were characterized by LC–MS–MS and compared to those detected in vivo. Sequential solvent elution on Oasis®-MCX-SPE cartridges was used to quantify [ 18 F]fallypride and its radiometabolites. Result: In rat microsomal incubations, five metabolites generated upon N/O-dealkylation or hydroxylation at the pyrrolidine and/or at the benzamide moiety were identified. No radiometabolite was detected in the rat brain. N-dealkylated and hydroxylated derivatives were detected in human microsomal incubations as well as in baboon plasma. The use of SPE (total recovery 100.2% ± 2.8%, extraction yield 95.5% ± 0.3%) allowed a complete separation of [ 18 F]fallypride from its radiometabolites in plasma and evaluate [ 18 F]fallypride at 150 min pi to be 22% ± 5% of plasma radioactivity. Conclusions: The major in vivo radiometabolites of [ 18 F]fallypride were produced by N-dealkylation and hydroxylation. Allowing the rapid analysis of multiple plasma samples, SPE is a method of choice for the determination of [ 18 F]fallypride until late images required for quantitative PET imaging in humans

  6. Applicability and sensitivity of gamma transmission and radiotracer techniques for mineral scaling studies

    Energy Technology Data Exchange (ETDEWEB)

    Bjoernstad, Tor; Stamatakis, Emanuel

    2006-05-15

    Mineral scaling in petroleum and geothermal production systems creates a substantial problem of flow impairment. It is a priority to develop methods for scale inhibition. To study scaling rates and mechanisms in laboratory flow experiments under simulated reservoir conditions two nuclear methods have been introduced and tested. The first applies the principle of gamma transmission to measure mass increase. Here, we use a 30 MBq source of 133Ba. The other method applies radioactive tracers of one or more of the scaling components. We have used the study of CaC03-precipitation, as an example of the applicability of the method where the main tracer used is 47Ca2+. While the first method must be regarded as an indirect method, the latter is a direct method where the reactions of specific components may be studied. Both methods are on-line, continuous and non-destructive, and capable to study scaling of liquids with saturation ratios as low as SR=1.5 or lower. A lower limit of detection for the transmission method in sand-packed columns with otherwise reasonable experimental parameters is less than 1 mg CaC03 in a 1 cm section of the tube packed with silica sand SiO2. A lower limit of detection for the tracer method with reasonable experimental parameters is less than 1 microgram in the same tube section. (author) (tk)

  7. Applicability and sensitivity of gamma transmission and radiotracer techniques for mineral scaling studies

    International Nuclear Information System (INIS)

    Bjoernstad, Tor; Stamatakis, Emanuel

    2006-05-01

    Mineral scaling in petroleum and geothermal production systems creates a substantial problem of flow impairment. It is a priority to develop methods for scale inhibition. To study scaling rates and mechanisms in laboratory flow experiments under simulated reservoir conditions two nuclear methods have been introduced and tested. The first applies the principle of gamma transmission to measure mass increase. Here, we use a 30 MBq source of 133Ba. The other method applies radioactive tracers of one or more of the scaling components. We have used the study of CaC03-precipitation, as an example of the applicability of the method where the main tracer used is 47Ca2+. While the first method must be regarded as an indirect method, the latter is a direct method where the reactions of specific components may be studied. Both methods are on-line, continuous and non-destructive, and capable to study scaling of liquids with saturation ratios as low as SR=1.5 or lower. A lower limit of detection for the transmission method in sand-packed columns with otherwise reasonable experimental parameters is less than 1 mg CaC03 in a 1 cm section of the tube packed with silica sand SiO2. A lower limit of detection for the tracer method with reasonable experimental parameters is less than 1 microgram in the same tube section. (author) (tk)

  8. Studies of the radiolabeling and biodistribution of substance P using lutetium-177 as a radiotracer

    International Nuclear Information System (INIS)

    Lima, Clarice Maria de

    2011-01-01

    Malignant gliomas are primary brain tumors, resistant to various treatments, as chemotherapy, radiotherapy, induction of apoptosis and surgery. An alternative for the treatment of malignant gliomas is the radionuclide therapy. This technique apply radiolabeled molecules that selectively bind to tumor cells producing cytotoxic effect by dose irradiation, and resulting in death of tumor cells. Most protocols for radionuclide therapy of malignant brain tumors involve the administration of peptides labeled with β - emitting radioisotopes. The Substance P (SP) is an 11- amino acid neuropeptide, characterized by the C-terminal sequence Phe-X-Gly-Leu-Met-NH 2 . The use of SP labeled with different radionuclides including 177 Lu, have been proposed for in vivo treatment of tumors. SP is the most important target of neurokinin 1 receptors, over expressed in malignant gliomas. The objective of this work was to study conditions of radiolabeling DOTA-SP with 177 Lu, the stability of labeled compound and in vivo and in vitro, to develop a protocol production and evaluate the potential of the radiopharmaceutical in the therapy of gliomas. The labeling conditions were optimized varying the temperature, reaction time, activity of lutetium-177 chloride and mass of DOTA-SP. The radiochemical purity of preparations were analyzed by chromatographic techniques. The stability of 17L u -DOTA- SP radiolabeled with low activity of 177 Lu was evaluated for different time at 2-8 degree C or incubated in human serum. The stability of the labeled with high activity of 177 Lu was also analyzed in the presence of gentisic acid (6 mg / mL) added after the labeling reaction. The labeled conditions in low and high activity were subjected to evaluation for the ability to cause oxidation of methionine residue, adding the D-L- methionine amino acid to the reaction medium (6 mg / mL) and subsequent chromatographic evaluation. In vitro study with 177 Lu-DOTA-SP, radiolabeled in the absence and presence

  9. Biosorption studies on shelled Moringa oleifera seeds for chromium removal using radiotracer

    International Nuclear Information System (INIS)

    Sharma, Parul; Srivastava, M.M.; Prakash, Satya; Srivastava, Shalini

    2007-01-01

    Shelled Moringa oleifera seeds (SMOS) have been explored as an indigenous, inexpensive and effective sorbent for chromium removal from water bodies. Sorption studies (batch) result into the standardization of optimum conditions for removal of 81.02% Cr (III) and 88.15% Cr (VI) pH 6.5 and 2.5 respectively. Percent sorption in each case was computed on the basis of chromium estimation using planar NaI (TI) detector, coupled to 4K MCA (Canberra Accuspec Card with PC AT 386). (author)

  10. Application of radiotracers in environmental pollution studies - Dynamic evaluation of heavy metals in tropical coast lagoon

    International Nuclear Information System (INIS)

    Fernandes, H.M.; Oliveira, A.E.; Veiga, L.H.S.; Patchineelam, S.R.

    1991-01-01

    In order to access the relative relevance structures of the metal translocation process among the geochemical phases of the sediment, a pool of radionuclides - sup(54)Mn, sup(65)Zn, sup(210)Pb and sup(109)Cd - was added to Jacarepagua lagoon water samples which were put in contact with lagoonal oxidized sediment. Radionuclides sediment absorption was very rapid - 100% of initial activity after 15 minutes of contact - except for sup(54)Mn which showed a retention of 74% of its initial activity in the same time period. The reducible fraction was found to be the main metal support for the studied radionuclides except for sup(54)Mn which was preferentially incorporated in the exchangeable fraction - 60% of the total activity. The oxidizable fraction accounted for no more than 10% of added radionuclides. These results showed the evidence of Fe and Mn oxides dissolution in the anoxic environment of Jacarepagua lagoon. Some of the scavenged metals of this phase may be however recaptured by sulfides anions, becoming associated to the oxidizable fraction. (author)

  11. Cyclotron production, radiochemical separation and quality control of platinum radiotracers for toxicological studies

    International Nuclear Information System (INIS)

    Bonardi, M.; Birattari, C.; Groppi, F.; Arginelli, D.; Gini, L.; Gallorini, M.

    1998-01-01

    The increasing concentration of Pt, Pd and Rh in the environment is mainly due to the release of these elements from the catalytic converters of the motorvehicles. This situation makes it necessary to carry out metallotoxicological experiments on both cell cultures and laboratory animals, in order to assess their impact on living organisms after a Long Term and Low Level Exposure (LLE). Both nuclear reactions nat Ir(p,xn) and nat Os(α,xn) were investigated in the energy range up to 45 MeV for protons and 38 MeV for alpha-particles, in order to optimize the irradiation parameters for the production of 188,189,191 Pt. Several sets of thin- and thick-target excitation functions were determined experimentally by cyclotron irradiation at both Milano and Ispra cyclotrons. This paper reports the irradiation parameters studied and adopted and two radiochemical procedures for the separation of radio-Pt from an Os target, as well as from ruthenium, iridium and gold impurities. These procedures were used to obtain very high specific activity Pt radionuclides in No Carrier Added (NCA) form. Radionuclidic, radiochemical and chemical purity measurements were carried out by the use of several techniques like γ-spectrometry, ion-exchange radio-chromatography, atomic absorption spectrometry and neutron activation analysis. (author)

  12. Improving phosphorus availability from Patos phosphate rock for Eucalyptus: a study with 32P radiotracer

    International Nuclear Information System (INIS)

    Villanueva, Felipe Carlos Alvarez; Muraoka, Takashi; Trevizam, Anderson Ricardo

    2006-01-01

    Eucalyptus plantation in Brazil is generally set on low fertility soils, therefore phosphorus (P) fertilization is mandatory and increases the cost of plantation operation. Using species that more efficiently uptake phosphorus from less soluble sources is an interesting option. However, little is known about eucalyptus regarding its ability of using less soluble forms of phosphorus. The use of P by eucalyptus (E. urophylla, E. grandis, and E. urophylla E. grandis) was studied in greenhouse using a loamy-textured, hipodystrophic Typic Haplustox from the Cerrado region, and 32P isotopic method. The P sources tested were triple superphosphate (TSP), phosphate rock (PR) and the triple superphosphate mixed with PR (TSP+PR). The effectiveness of P sources in terms of increasing dry matter yield was TSP = (TSP + PR) > PR, and the P uptake followed the order (TSP + PR) > TSP > PR for both species plus the hybrid. The increase in P uptake from PR due to TSP influence was 217.3% for E. urophylla, 235.7% for E. grandis, and 28.7% for E. urophylla E. grandis, indicating an enhancement effect of TSP on the effectiveness of PR. The hybrid E. urophylla E. grandis was the most efficient genotype on P soil use and E. grandis most exigent in P fertilizer. (author)

  13. Studies of the magnitude and nature of pesticide residues in stored products, using radiotracer techniques

    International Nuclear Information System (INIS)

    1990-01-01

    Growing world population and food demand have dictated the introduction of intensive agricultural practices, including the use of an increasing range of agrochemicals. The utilization of these chemicals has a positive and often dramatic impact on agricultural production, but every effort has to be made to ensure safety in use. This is a dynamic challenge for many countries and necessitates the implementation of adequate monitoring programmes. Even when pesticide use conforms to currently adopted standards of good management practice, undesirable side effects may occur and could, at times, endanger public health. Nuclear techniques provide a valuable tool for studying pesticide residues in stored food commodities. Radioisotopes can be used to determine total quantities of residue present, the nature of the residue (i.e. both undecomposed parent material and reaction products), rates of breakdown and loss and distribution in the food material. All of this information is essential for health and regulatory authorities to establish and maintain comprehensive tolerance standards that will protect the health of the consumer. The use of 14 C labelled compounds constitutes a superior and unrivalled tool, in particular for the detection and quantification of grain bound residues. All pesticide residues remaining on or in food materials are of potential concern to human health. Surface residues that remain on commodities such as grain may present an occupational risk to workers exposed to dust emanating from the commodity; residues that remain in food may be a hazard to the consumer. The nature of the residue, the quantity present and its toxicological significance should be known so that tolerance levels can be established and complied with. Refs, figs and tabs

  14. Studies on the transfer of Cs, Sr, Co, Mn and Zn from soil to plants and from medium to mushrooms by using radiotracer

    International Nuclear Information System (INIS)

    Ban-nai, Tadaaki; Muramatsu, Yasuyuki; Yoshida, Satoshi; Yanagisawa, Kei

    1996-01-01

    Radiotracer experiments were carried out to study radionuclide uptake by plants and mushrooms. Transfer factors of radionuclides from soil to leaf vegetables (cabbage, Chinese cabbage, komatsuna, spinach and lettuce) have been determined by radiotracers. The transfer factors of radioactive Cs, Sr, Mn, Co and Zn for edible parts of vegetables were 0.11, 0.24, 0.61, 0.05 and 0.52, respectively. The transfer factors of Mn, Co and Zn for spinach were higher than those for the other vegetables. The transfer factors of Cs for different organs of the leaf vegetables were rather homogeneous. The transfer factors of Sr and Mn were higher for older (outer) leaves than younger (inner) ones. In contrast to Sr and Mn, transfer factors of Zn for younger leaves were higher than those for older ones. In order to study radionuclide uptake by mushrooms, cultivation experiments in flasks were carried out using radiotracers, 137 Cs, 85 Sr, 60 Co, 54 Mn and 65 Zn. Four mushroom species Hebeloma vinosophyllum, Flammulina velutipes, Agrocybe cylindracea and Coprinus phlyctidosporus were used. In addition, Medicago sativa was also tested. Mushrooms tended to accumulate Cs, although there was a large difference between mushroom species. The concentration ratio had the highest value of 21 for Cs in vinosophyllum. The value was much higher than that in the plant sample. The present findings agreed with our previous observations in which Hebeloma species collected in forests contained large amount of 137 Cs. The effects of stable elements in the medium on the accumulations were investigated. The concentration ratios of Cs, Sr and Co were not influenced highly by coexisting stable elements in the medium. However, the ratio of Mn decreased as the amount of coexisting stable elements in the medium was increased. (J.P.N.)

  15. Leak Detection in Heat Exchangers and Underground Pipelines Using Radiotracers. Material for Education and On-The-Job Training for Practitioners of Radiotracer Technology

    International Nuclear Information System (INIS)

    2009-01-01

    The International Atomic Energy Agency plays a major role in facilitating the transfer of radiotracer technology to developing Member States. The use of radiotracer techniques is well established in many Member States; some hundred radiotracer and end user specialists have been trained in radiotracer techniques and their applications; nearly 50 radiotracer laboratories have been working in this field. The training of radiotracer practitioners is vital for the provision of quality services to industry. Leak detection using radiotracer techniques is probably one of the most widespread applications of radiotracers in industrial troubleshooting. Radiotracer techniques are the most competitive for online leak inspection of heat exchangers and buried pipelines. Radiotracers help in early detection of leaks in heat exchangers and underground transporting pipelines, thus saving money, reducing shutdown time, ensuring safe operation and protecting the environment from pollution. The training course series on leak detection in heat exchangers and underground pipelines using radiotracers addresses the needs of the radiotracer groups and their end users. Besides training purposes, this material will assist radiotracer groups in establishing their quality control and accreditation systems. This training course material is based on lecture notes and practical work delivered by many experts in IAEA-supported activities. In particular, the Technical Cooperation Projects implemented under the Regional Cooperative Agreement (RCA) of the IAEA Member States in the Asia and the Pacific Region have been successful in transferring and implementing radiotracer techniques for leak detection to many end users from oil and gas production, oil refineries and the petrochemical industry. The experience obtained in the RCA Region is presented in the training material illustrated with many case studies carried out in several RCA Member States. Lectures and case studies were reviewed by a number

  16. Radiotracer design strategies for neurocardiology

    International Nuclear Information System (INIS)

    Wieland, D.M.; Hutchins, G.D.

    1991-01-01

    Nuclear cardiologists have expended an inordinate amount of effort studying the open-quotes plumbingclose quotes of the heart but very little effort on the open-quotes wiringclose quotes. L. Rossi declared in 1988, open-quotes today's desultory information about basic changes in the heart's innervation, if compared with current knowledge about diseases of cardiac muscle and vessels, is largely attributable to an aura of forbidding technical difficulty.close-quote During the past three years, radiotracers have been developed for use in studies of cardiac nerve function by positron emission tomography (PET). The first clinical PET studies in this area were reported in 1990. This chapter discusses the strategies that led to the tracers presently available and the possible nature of future neuronal markers

  17. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique.

    Science.gov (United States)

    Ghiyas Ud Din; Imran Rafiq Chughtai; Hameed Inayat, Mansoor; Hussain Khan, Iqbal

    2009-01-01

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and (99m)Tc in the form of sodium pertechnetate eluted from a (99)Mo/(99m)Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer (99m)Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  18. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique

    International Nuclear Information System (INIS)

    Ghiyas Ud Din; Imran Rafiq Chughtai; Mansoor Hameed Inayat; Iqbal Hussain Khan

    2009-01-01

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and 99m Tc in the form of sodium pertechnetate eluted from a 99 Mo/ 99m Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer 99m Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  19. The use of radiotracers in natural rubber research in Malaysia

    International Nuclear Information System (INIS)

    Lai, P.F.; Singh, M.M.

    1981-01-01

    Five main areas where radiotracers have been used in research on natural rubber are on studies on the uptake of plant nutrients by Hevea brasiliensis using 32 P, 86 Rb and 45 Ca as tracers; biosynthesis of Hevea rubber using 14 C or 3 H labelled intermediates; translocation and metabolism of 14 C. Ethephon in Hevea brasiliensis; use of radiotracers as analytical tools and adsorption of labelled fatty acid soaps on natural rubber lattices. These studies are discussed to show the powerful tool that radiotracers provide in agricultural, biochemical and chemical research on natural rubber. (author)

  20. Design and synthesis of enantiomerically enriched, radiolabeled MK-801 analogs as potential radiotracers for imaging and autoradiographic studies of the NMDA receptor-ion channel complex

    International Nuclear Information System (INIS)

    Eng, W.S.; Burns, H.D.; Gibson, R.E.; Ransom, R.W.; Thorpe, H.; Fioravanit, C.; Britcher, S.F.; Magill, C.A.; Solomon, H.F.; Dannals, R.F.; Wilson, A.A.; Ravert, H.T.; Wagner, H.N.

    1989-01-01

    MK-801 is a potent, non-competitive antagonist for the N-methyl-D-asspartate (NMDA) receptor-ion channel complex. This complex is though to be involved in nerve cell damage in stroke patients when excess calcium is released through the activated channel. A thorough understanding of drug interactions with the NMDA receptor complex could lead to improved therapy for reducing hypoxic-ischemic neuronal injuries in stroke patients. Based on the results of extensive structure-activity studies, the authors have developed several enantiomerically enriched, radiolabeled analogs of MK-801, including: 3-1231-MK-801 for Single Photon Emission Computed tomography (SPECT); 3-1251-MK-801 for in-vivo and in-vitro autoradiography; 8-11C-MeO-MK-801 for Positron Emission Tomography (PET). Details of the synthesis of these radiotracers and their application to both in-vitro and in-vivo studies are described

  1. Synthesis of new radiotracers based of Ethyl Ester

    International Nuclear Information System (INIS)

    Trabelsi, Donia

    2008-01-01

    The in vivo study of a biochemical or physiological process requires the synthesis of specific radiotracers but also the targeting of these compounds so that they can reach their target tissue. Methodologies original synthesis associated with radioisotopes used, the quantities and chemical forms often have to be available developed. The chemistry of metal complexes booming, we were able to use the ethyl ester combined with technetium, forming a stable radiotracer. Finally, a counting of radioactivity in different rat's organs completed our study. (Author)

  2. Use of low cost dead biomasses in the removal of heavy metal toxic/radiotoxic ions from aqueous wastes- a radiotracer study

    International Nuclear Information System (INIS)

    Mishra, Shuddhodan P.

    2005-01-01

    In an environmental context, accelerating pollution by toxic metal ions, metalloids, radionuclides and organometal (loid)s has provided the impetus for the research to look into the biotechnological potential of utilizing several low cost dead biomasses/agricultural byproducts to replace existing expensive technologies. Unlike organic pollutants which are biodegradable, these metallic contaminants tend to persist rather indefinitely in the environment, and are eventually accumulated through the food chain thus posing a serious threat to plants, animal and man. The use of radiotracer technique by several workers and ourselves in the study of adsorption uptake or ions (cations and anions) from aqueous solutions by metals/metals oxide surfaces at micro down to tracer level concentrations had been quite rewarding. In continuation of this work the present studies were directed to assess the uptake behaviour of abundantly available low cost dead biomasses [e.g. Rice hulls (oryza sativa L),] Mango (mangifera indica) and Neem (azadirachta indica)barks] towards some heavy metal (Hg 2+ , Cd 2+ , Cr 2+ , Zn 2+ and Ce 3+ ) toxic and radiotoxic (Sr 2+ and Cs l+ )ions from aqueous solutions at low ionic concentrations (10 -2 -10 -8 mol dm -3 ). In all these studies the adsorptive solution was labeled by a suitable radiotracer of the metal ion and the uptake of ions by the three biosorbents was assessed through monitoring of the decrease in radioactivity of the bulk. A parametric study through change of temperature, pH and addition of other co-ions/complexing agents has helped in deducing the thermodynamic parameters and mechanism of the uptake of the ions. The extent of removal of metal ions by these dead biomasses is quite high in most cases and the nature of the uptake appears to be exchange type. These findings show that the agricultural byproducts (dead biomasses) can be utilized in the development of waste water treatment technology for removal of heavy metal toxic and

  3. Report on second FAO/IAEA research coordination meeting on radiotracer studies of fungicide residues in food plants - Neuherberg, Germany, F.R., 4-8 May 1987

    International Nuclear Information System (INIS)

    1987-01-01

    In 1984, the FAO/IAEA Joint Division established the coordinated research programme on 'Radiotracer studies of fungicide residues in food plants'. The first FAO/IAEA research coordination meeting of the programme was held in Panama City, Panama in October 1985. It established a framework for experiments by the participating researchers to investigate metabolism and terminal residues of ethylenebisdithiocarbamates in food plants using 14 C-labelled materials with associated and other techniques. In this second report, progress made since the first report is presented and the further research needed to fulfill the objectives of the programme is outlined. The objectives of the meeting were as follows: To review progress within the coordinated research programme; To discuss problems pertinent to methodologies and labelled substrates; To prepare a report and recommendations with particular reference to future needs and priorities. The 12 papers presented at the meeting are given in summary form. (orig./MG)

  4. Radiotracer investigations in oil production and water injection wells

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.; Kirti

    1977-01-01

    Injection of gamma emitting radiotracers into oil wells followed by logging provides information on several aspects such as the identification of zones of seepage of water in the water injection wells and also the location of source of water entering oil producting wells. The experience gained in the application of bromine-82 and rubidium-86 as radiotracers in such studies at the Ankleshwar and Kalol oil fields in Gujarat and Nazira in Assam has been briefly reported. (author)

  5. Radiotracer investigations for sediment transport in ports of India

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Goswami, Sunil; Singh, Gursharan

    2013-01-01

    The knowledge of mixing and transport of sediments in coastal region is of vital importance for evaluating suitability of dumping site for dredged sediments produced during maintenance of shipping channels, expansion of existing projects and construction of new projects. Gamma-emitting radiotracers are commonly used for investigation of movement of sediments on seabed using Scandium-46 (scandium glass powder) as radiotracer. The radiotracer is injected on seabed at a desired location and its movement followed over a period of time using waterproof NaI(Tl) scintillation detectors. The recorded data is analyzed to obtain transport parameters and utilized for assessing the suitability of the dumping sites and optimization of the dredging operations. About 70 large-scale investigations have been carried out in different ports in India leading to significant economical benefits to the Ports. Present paper discusses various aspects of the radiotracer technique for sediment transport, methodology of data analysis and a specific case study. (author)

  6. Increased bone radiotracer uptake in renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    de Graaf, P.; Schicht, I.M.; de Graeff, J.; te Velde, J.; Kleiverda, K.; Pauwels, E.K.J.

    1982-04-01

    Bone radiotracer uptake in renal osteodystrophy was investigated in 35 dialysis patients by correlating the results of quantitative bone scintigraphy with those of biochemical and bone morphometric studies. There were highly significant correlations (P < 0.001) between the total skeletal activity and the biochemical (iPTH and alkaline phosphatase), and histologic parameters of hyperparathyroidism. These clinical results strongly suggest that increased bone turnover i.e. hyperparathyroidism, rather than osteomalacia is the major cause of increased skeletal uptake in renal osteodystrophy.

  7. Overview of radiotracer experiments for better understanding of wastewater and water treatment plants in Lima (Peru))

    International Nuclear Information System (INIS)

    Calvo, C.S.; Maghella, G.; Mamani, E.; Berne, P.; Brisset, P.; Leclerc, J.-P.

    2004-01-01

    The objectives of this paper are to present an overview of possible applications of the radiotracers for better understanding of water and waste water treatment plants. Numerous experiments have been carried out in different plants located in Lima. Four processes have been investigated: desanders, floculators, clarifiers and digesters. Depending on the studied process, the experimental results have been interpreted at different levels of complexity: from simple troubleshooting to the modelling of the flow behaviour inside the process. (author)

  8. Flow Rate Measurement in Multiphase Flow Rig: Radiotracer and Conventional

    International Nuclear Information System (INIS)

    Nazrul Hizam Yusoff; Noraishah Othman; Nurliyana Abdullah; Amirul Syafiq Mohd Yunos; Rasif Mohd Zain; Roslan Yahya

    2015-01-01

    Applications of radiotracer technology are prevalent throughout oil refineries worldwide, and this industry is one of the main users and beneficiaries of the technology. Radioactive tracers have been used to a great extent in many applications i.e. flow rate measurement, RTD, plant integrity evaluation and enhancing oil production in oil fields. Chemical and petrochemical plants are generally continuously operating and technically complex where the radiotracer techniques are very competitive and largely applied for troubleshooting inspection and process analysis. Flow rate measurement is a typical application of radiotracers. For flow measurements, tracer data are important, rather than the RTD models. Research is going on in refining the existing methods for single phase flow measurement, and in developing new methods for multiphase flow without sampling. The tracer techniques for single phase flow measurements are recognized as ISO standards. This paper presents technical aspect of laboratory experiments, which have been carried out using Molybdenum-99 - Mo99 (radiotracer) to study and determine the flow rate of liquid in multiphase flow rig. The multiphase flow rig consists of 58.7 m long and 20 cm diameter pipeline that can accommodate about 0.296 m 3 of liquid. Tap water was used as liquid flow in pipeline and conventional flow meters were also installed at the flow rig. The flow rate results; radiotracer and conventional flow meter were compared. The total count method was applied for radiotracer technique and showed the comparable results with conventional flow meter. (author)

  9. Panel discussion: Chemistry aspects of pet radiotracers

    International Nuclear Information System (INIS)

    Kilbourn, M.R.

    1991-01-01

    A panel discussion on the radiotracer development process opened with a question regarding the role of toxicological studies in the process of obtaining a physician-sponsored Investigational New Drug (IND) for a new radiopharmaceutical. Panel members were uniformly supportive of new radiotracer development, expressing their opinions that the regulatory hurdles were there but could be overcome. Several institutions are actively working with regulatory agencies to determine just what toxicology data are relevant to new radiopharmaceutical development in the PET field. The FDA is beginning to understand that the pharmacology of PET tracer doses may be completely different from what is usually important in drug trials. The second part of the panel discussion centered on the role, if any, of the pharmaceutical companies in new radiotracer development. It was pointed out that what the radiochemist is looking for in a radiopharmaceutical is different from what these companies are searching for in a therapeutic drug. Panel and audience members responded to the question: What would a pharmaceutical company gain from collaboration with radiopharmaceutical research laboratories? Several examples were given such as providing crucial data from humans rather than animals; determining individualized drug doses to maximize the therapeutic index of a new drug regimen; and replacing the large amounts of time and money currently invested by drug companies in the radiolabeling and evaluation of metabolites of new drugs

  10. Research reactors serving the radiotracer technique: An overlooked opportunity?

    International Nuclear Information System (INIS)

    Bode, P.

    2010-01-01

    The unique features of using radiotracers are not always fully explored at nuclear research reactor centers. The radiotracer method is a versatile and powerful tool in the study of a wide variety of applications in e.g. chemistry, biology, agriculture, medicine and (industrial) technology. The big advantage of radiotracers above e.g. stable isotope tracers, commonly applied in e.g. nutritional studies, is that radiotracers allow for non-invasive studies of both steady-state and dynamic systems, in equilibrium situations and for transport and exchange phenomena and thus provide information on the chemical and/or physical status of elements. The radiotracer method does not imply huge equipment investments but rather requires that the four interrelated aspects: experimental designs, data treatment including tracer kinetic analysis and data interpretation are careful considered. Radiotracer production with reactors often implies additional fundamental research to use smart nuclear reactions and chemical separations so as to obtain an almost no-carrier added tracer. Nuclear analytical groups, already equipped with gamma-ray spectrometers, can thus extend their research program. Using Ge-spectrometers, multi-labeling experiments are possible which allow for unique applications if different radionuclides exist for the same element, such as 65 Zn and 69m Zn or 64 Cu and 67 Cu. The developments in novel scintillation detectors, room-temperature semiconductor detectors (like CdZnTe) and position-sensitive detectors open the door for an entire new scope of radiotracer applications, such as SPECT. Once applied to in-vitro studies with cell cultures, the nuclear analytical group may position itself into the worlds of medical research, biochemistry and biotechnology. Radiotracers can be used to study the properties of drug-delivering compounds as used in e.g, cancer therapy. Radiotracers can be added as a label to solid particles, to liquids but may also be applied in the

  11. Radiotracer study of wash load movement in a drum-type fabric washing machine using a gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Balt, A.P.; Brekel, L.D.M. van den; Vandecasteele, C.; Kolar, Z.

    1987-01-01

    A study was made of the movement of the wash loads in a drum-type washing machine. For this purpose a sup(99m)Tc source was attached to one or two separate textile pieces and the subsequent source positions were determined by means of a gamma-camera. The wash load movement pattern appears to depend on the type of textile material and its amount, as well as on the volume of water present in the washing machine.

  12. Radiotracer study of wash load movement in a drum-type fabric washing machine using a gamma camera

    International Nuclear Information System (INIS)

    Balt, A.P.; Brekel, L.D.M. van den; Vandecasteele, C.; Kolar, Z.

    1987-01-01

    A study was made of the movement of the wash loads in a drum-type washing machine. For this purpose a sup(99m)Tc source was attached to one or two separate textile pieces and the subsequent source positions were determined by means of a gamma-camera. The wash load movement pattern appears to depend on the type of textile material and its amount, as well as on the volume of water present in the washing machine. (author)

  13. Imaging in hearing using radiotracers

    Directory of Open Access Journals (Sweden)

    Berding Georg

    2017-09-01

    Full Text Available Radiotracers offer unique options for brain imaging of functional and molecular processes related to hearing. Such imaging can be applied in a broad spectrum of situations from preclinical research to clinical patient care. Functional imaging to assess activation in brain regions and networks involved in auditory processing uses markers of blood flow or energy-metabolism in well-defined conditions with and without auditory stimulation. Molecular markers can be used in hearing research for example to study changes in inhibitory neurotransmission systems related to hearing loss. For imaging either positron emission tomography (PET or single-photon emission computed tomography (SPECT are employed. Data analysis can encompasses voxel-wise statistical analysis of activation and calculation of quantitative parameters like receptor binding-potentials based on bio-kinetic modeling. Functional imaging has been frequently used in the context of auditory implantation. Before implantation it aims to assess intactness of the central auditory pathway and prognosis. After implantation it is used to improve understanding of the outcome with respect to auditory function and finally speech understanding, e.g. by measuring correlates of central auditory processing and neuroplasticity.

  14. Fostering the local production and application of industrial radiotracers in developing countries - IAEA's role

    International Nuclear Information System (INIS)

    Mohammad Haji-Saeid, S.; Jin, Joon-Ha; Ramamoorthy, Natesan; )

    2006-01-01

    Radiotracer techniques provide fast and accurate information for solving various process problems in industrial plants. The IAEA is playing an important role in supporting the development and transfer of radiotracer techniques to developing countries. The IAEA has implemented 5 coordinated research projects (CRP), including two on-going projects, in the field of radiotracer and sealed source applications in industry. The CRPs facilitated the acquisition and dissemination of know-how and technology for wear/corrosion measurement, residence time: distribution (RTD) study, validation of computed fluid dynamics data, industrial process tomography and inter-well connectivity study. A number of technical cooperation projects have been executed to strengthen the capability of radiotracer groups in developing Member States and to create awareness in the industries about the technical and economical benefits of radiotracer technology. The IAEA's regional projects have strongly impacted the transfer and adoption of the techniques. The status of radiotracer use in developing countries reveals that the lack of timely availability of radiotracers as one of the major problems. Development of some radionuclide generators is a possible solution. Cooperation among the international radiotracer communities is necessary to enhance the availability and use of radiotracers in developing countries. (author)

  15. A radiotracer study on the volatilization and transport effects of thermochemical reagents used in the analysis of alumina powders by slurry electrothermal vaporization inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Peschel, Birgit U.; Herdering, Wilhelm; Broekaert, Jose A.C.

    2007-01-01

    A neutron-activated Al 2 O 3 powder SRM 699 (NIST) containing the γ-radiation emitting radionuclides 51 Cr, 59 Fe, 60 Co and 65 Zn has been used to study the influence of thermochemical reagents on the volatilization and transport efficiency for these trace elements in electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) of Al 2 O 3 powders. From the signals in the γ-spectra for the radiotracers it has been found that less than 2% of the elements Cr, Fe, Co and Zn is left back in a graphite furnace from Al 2 O 3 powders at 2200 deg. C even without addition of a thermochemical reagent and the latter even was found to decrease the volatilization efficiencies. The recovery for the radiotracers on filters at the end of the transport tube as measured from the signals in the γ-spectra, however, was found to increase in most cases (i.e. from about 10% to more than 20%) when Pd(NO 3 ) 2 , Pd(NO 3 ) 2 + Mg(NO 3 ) 2 , PdCl 2 , IrCl 3 , SnCl 2 , AgCl, NaF, NH 4 Cl and NH 4 F were added at amounts generally used in electrothermal vaporization inductively coupled plasma mass spectrometry. However, when adding higher amounts as stoichiometrically required for a complete halogenation of the sample matrix in the case of AgCl, C 8 F 15 O 2 Na, IrCl 3 or PdCl 2 the transport efficiencies considerably decrease again. As shown in the case of NH 4 Cl the amount of thermochemical reagent used has to be optimized so as to obtain maximum analyte transport efficiencies. A comparison of the influence of NH 4 Cl on the transport efficiencies with its influence on the ETV-ICP-MS signals for Fe demonstrates the importance of transport efficiency changes for the effects of thermochemical reagents in electrothermal vaporization inductively coupled plasma mass spectrometry

  16. Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse

    International Nuclear Information System (INIS)

    Gerasimov, Madina R.; Ferrieri, Richard A.; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding Yushin

    2005-01-01

    The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11 C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [ 11 C]toluene to include [ 11 C]acetone and [ 11 C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [ 11 C]toluene and [ 11 C]acetone were administered intravenously and [ 11 C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [ 11 C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane

  17. Radiotracer study in a distillation tower with Na-24; Estudio de radiotrazado en una torre de destilacion con Na-24

    Energy Technology Data Exchange (ETDEWEB)

    Vizuet G, J.; Molina, G.; Angeles C, A.; Garcia M, T.; Ruiz C, M. A.; Benitez S, J. A.; Flores M, J., E-mail: Jorge.vizuet@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The present summary describes the carried out work of the application of the techniques of gamma profiling in a distillation tower, for the oil industry in Mexico. The study consisted on the application of the gamma profiling technique. An arrangement detector source aligned in a horizontal way was collocated to make a vertical scanning along the tower, in such a way that the signal obtained by this technique allows see the interior of the same one, with the objective of being able to diagnose its operation conditions. According to the applied technique, the height of the signal obtained in the graphs depends on the attenuation of the source radiation, in such a way that if crosses areas of more or small density, the width of the signal decreases or is increased and starting from these results a diagnostic was interpreted. For the profiling service of the distillation tower, Na-24 source and radiation detection equipment coupled to a system of data acquisition was used. Relative to radiological protection a controlled area was defined where the radioactive source was used to avoid unnecessary exhibitions to the plant personnel. Relative to the technique use, in this case stands out the use of Na-24 like source since they required this way the conditions of thickness and diameter of the tower. At the end of the study satisfactory results were obtained. (Author)

  18. Radiotracer techniques in mineral processing

    International Nuclear Information System (INIS)

    Przewlocki, K.

    1991-01-01

    The value of the smelter metal content in currently exploited polymetallic ores mostly does not exceed 2%. Before metallurgical treatment, ore must pass through the concentration process. The benefication process usually starts from the comminution of excavated material and terminates at the flotation and drying of the concentrate. These operations consume vast quantities of energy. To be economically justified, the process requires optimization and, if possible, automatic control. Radioactive tracers were found to be useful in the identification of particular technological subsystems and their subsequent optimization. A great deal of experience has been gathered in this field so far. The industrial radiotracer test (RTT) is carried out using very sensitive multidetector recording systems which have digital data acquisition capabilities. The optimization strategy consists of periodically adjusting technological process and set points of controlled variables according to certain improvement procedures. If computer facilities are available, data interpretation and calibration of the mathematical models describing the technical process itself can be performed on the spot. This significantly accelerates the whole procedure as RTT may be repeated for particular system configurations. The procedure of plant optimization by means of RTT is illustrated in the paper using the example of the copper ore enrichment process, assuming that it is representative of the whole mineral industry. Identification by RTT of the three main operations involved in the ore enrichment process, such as comminution, flotation and granular classification, is discussed in detail as particular case studies. In reference to this, it is also shown how the technological process can be adjusted to be most efficient. (author). 14 refs, 7 figs

  19. Radiotracers for PETT: new developments and perspectives

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1983-01-01

    Radiotracer development with positron emitters has its major focus on problems in the neurosciences. Progress is reviewed for high-level isotope production and labelled precurser synthesis with the medical cyclotron. The study of regional brain glucose metabolism represented the first extension of one of the methods of neurochemical autoradiography to humans and the study of brain protein synthesis and neurotransmitter receptors followed. In a more general sense, one PETT instrumentation will provide resolution in the 5 mm range is already emerging. Research status is reviewed. 103 references

  20. Radiotracers for PETT: new developments and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1983-01-01

    Radiotracer development with positron emitters has its major focus on problems in the neurosciences. Progress is reviewed for high-level isotope production and labelled precurser synthesis with the medical cyclotron. The study of regional brain glucose metabolism represented the first extension of one of the methods of neurochemical autoradiography to humans and the study of brain protein synthesis and neurotransmitter receptors followed. In a more general sense, one PETT instrumentation will provide resolution in the 5 mm range is already emerging. Research status is reviewed. 103 references. (PSB)

  1. [{sup 11}C]A-69024: A potent and selective non-benzazepine radiotracer for in vivo studies of dopamine D1 receptors

    Energy Technology Data Exchange (ETDEWEB)

    Kassiou, Michael; Scheffel, Ursula; Ravert, Hayden T; Mathews, William B; Musachio, John L; Lambrecht, Richard M; Dannals, Robert F

    1995-02-01

    [{sup 11}C]A-69024, ({+-})-1-(2-bromo-4,5-dimethoxybenzyl)-7-hydroxy-6-methoxy-2-[{sup 11}C]methyl-1,2= ,3,4-tetrahydroisoquinoline, is a specific and selective dopamine D1 radiotracer. The in vivo biodistribution of this novel radioligand in mice showed a high uptake in the striatum (6.7% ID/g) at 5 min, followed by clearance with a half-life of 16.1 min. As a measure of specificity, the striatal/cerebellar ratio reached a maximum of 7.4 at 30 min post-injection. Radioactivity in the striatum was reduced to the level of the cerebellum by pre-administration of the D1 antagonist SCH 23390 (1 mg/kg). Pretreatment of mice with spiperone (D2), 7-hydroxydipropylaminotetralin (7-OH-DPAT) (D3), clozapine (D4), ketanserin (5-HT2/5-HT2C), mazindol (monoamine reuptake), prazosin ({alpha}{sub 1}), and haloperidol (D2/{sigma}) had no inhibitory effect on [{sup 11}C]A-69024 uptake in the striatum. The dextrotatory enantiomer of the dopamine antagonist butaclamol inhibited striatal uptake, while the less active isomer (-)-butaclamol did not. [{sup 11}C]A-69024 binding was inhibited by unlabeled A-69024 in a dose dependent manner (ED{sub 50} = 0.3 mg/kg) in the striatum while no change occurred in the cerebellum. [{sup 11}C]A-69024 warrants further investigation as a PET ligand for examination of central dopamine D1 receptors in humans.

  2. The early use of radiotracers in chemistry

    International Nuclear Information System (INIS)

    Grabowski, K.F.M.

    1986-01-01

    This article describes the historical background to the use of radiotracers, pioneered by de Hevesy and Paneth before World War I. It traces their early use in ion and metal interchange in electrolysis, self-diffusion rates, early biochemical experiments on lead uptake in plants, phosphorus metabolism in rats, through to their wider use with the production of artificial radioisotopes after World War II. Photosynthesis experiments using carbon-11 and carbon-14 are described and their present-day widespread use in kinetics, metabolic pathway studies and therapeutics is discussed. (UK)

  3. Investigation of liquid phase axial dispersion in Taylor bubble flow by radiotracer residence time distribution analysis

    Directory of Open Access Journals (Sweden)

    Jin J.H.

    2013-05-01

    Full Text Available A gas-liquid Taylor bubble flow occurs in small diameter channels in which gas bubbles are separated by slugs of pure liquid. This type of flow regime is well suited for solid catalyzed gas-liquid reactors in which the reaction efficiency is a strong function of axial dispersion in the regions of pure liquid. This paper presents an experimental study of liquid phase axial dispersion in a Taylor bubble flow developed in a horizontal tube using high speed photography and radiotracer residence time distribution (RTD analysis. A parametric dependence of axial dispersion on average volume fraction of gas phase was also investigated by varying the relative volumetric flow rates of the two phases. 137mBa produced from a 137Cs/137mBa radionuclide generator was used as radiotracer and measurements were made using the NaI(Tl scintillation detectors. Validation of 137mBa in the form of barium chloride as aqueous phase radiotracer was also carried out. Axial Dispersion Model (ADM was used to simulate the hydrodynamics of the system and the results of the experiment are presented. It was observed that the system is characterized by very high values of Peclet Number (Pe∼102 which reveals an approaching plug type flow. The experimental and model estimated values of mean residence times were observed in agreement with each other.

  4. Biosorptive behavior of Mango (Mangifera indica) and Neem (Azadirachta indica) barks for Cs-134 from aqueous solutions: A radiotracer study

    International Nuclear Information System (INIS)

    Mishra, Shuddhodan P.; Diwakar Tiwari; Prasad, S.K.; Dubey, R.S.; Manisha Mishra

    2005-01-01

    The role of dead biomasses in the removal of heavy metal toxic ions has received an increased attention due to their large abundance and low cost solids. In line with much interest we tried to employ such solids viz., Mango (Mangifera indica) and Neem (Azadirachta indica) bark samples in the removal of one of the important fission fragment viz., strontium and indeed these are found to be quite promishing for such studies. In addition to their good uptake behavior, these solids are also found to be fairly stable towards ionizing radiations. Here, an attempt has been made to study for the removal behavior of Mangifera indica and Azadirachta indica bark samples for 134 Cs. The barks of Mangifera indica and Azadirachta indica were obtained from the vast region of Banaras Hindu University campus. Bark samples were dried at room temperature and then crushed and washed repeatedly by double distilled water and again dried at room temperature. The sorption of Cs(I) on these bark samples were carried out as a function of sorptive concentration (1.0 x 10 -2 to 1.0 x 10 -8 mol dm -3 ) at constant temperature 298 K and pH∼6.0. Quantitatively, it was observed that the amount of Cs(I) adsorbed on these solids increased from 0.175 x 10 -9 to 0.051 x 10 -3 mol g -1 for Mangifera indica and from 0.310 x 10 -9 to 0.102 x 10 -3 mol g -1 for Azadirachta indica with the increase in sorptive concentration from 1.0 x 10 -8 to 1.0 x 10 -2 mol dm -3 . However, the percent sorption decreased from 17.5 to 5.1% for Magifera indica and from 31.0 to 10.2% for Azadirachta indica for the corresponding increase in sorptive concentration. This decrease in percent sorption is likely due to the lesser number of surface active sites, available for higher number of sorptive species. Further, the concentration dependence data were utilized for analysing the adsorption isotherm and it was found that these are fitted well for Freundlich adsorption isotherm to its linearized logarithmic form (Log a e

  5. Radiotracer techniques for measuring fluid flow and calibrating flow meters

    International Nuclear Information System (INIS)

    Cooper, E.L.

    1987-08-01

    Radiotracer techniques can be used to measure accurately both gas and liquid flow rates under operating conditions in a wide range of flow systems. They are ideally suited for calibrating flow meters as well as for measuring unmetered flows in industrial plants. Applications of these techniques range from measuring the flows of fuels and process fluids for energy and mass balance studies to measuring the flows of liquid and airborne effluents for pollution control. This report describes the various radiotracer techniques which can be used to measure fluid flows. The range of application and inherent accuracy of each technique is discussed

  6. Radiotracers in Swedish Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, I.; Erwall, L. G. [Isotope Techniques Laboratory, Stockholm (Sweden); Nyquist, O. [Surahammars Bruks AB, Surahammar (Sweden)

    1967-06-15

    Recent tracer investigations in Swedish steel plants have mainly dealt with problems concerning uon-metallic inclusions, slag weight determination and - labelling of special steel qualities for identification. Suspected inclusion sources, such as furnace slag, ladle-bottom mortar and some brick materials as stopper, nozzle.and channel bricks have been labelled radioactively in different ways. The labelling technique has been studied for the different systems and a new method was developed for brick materials. This includes vacuum impregnation with an aqueous solution of the inactive tracer, reheating to 1300 Degree-Sign C and neutron-irradiation in a reactor. A sufficiently homogeneous labelling of the material was obtained in this way. The tracer used was terbium, which was added as the nitrate and then decomposed to oxide during the heating process. The oxide is strongly bound to the ceramic material. The number of radioactive inclusions was determined by.autoradiography, and related to the total number pf inclusions, obtained by visual slag-counting, to give the percentage of inclusions originating from the labelled object. Some investigations have been made using simultaneous labelling of two or more sources. It seems to be difficult, however, to measure separately more than two tracers: one short-lived (e.g. 140La) and one long-lived (e.g. {sup 160}Tb). The slag weight determinations were made using the isotope dilution technique with {sup 131}Ba and {sup 140}La as tracers. A difference in slag weight is sometimes obtained. An attempt is made to explain these deviations. The material transport through a blast furnace has been followed by using a piece of graphite, labelled with {sup 140}La{sub 2}O{sub 3}, and measuring the radiation intensity outside the furnace walls and in the tuyere. Studies have been made to determine suitable radiotracers for labelling of steel for subsequent identification. Up to three different isotopes can be used simultaneously

  7. The heritage of radiotracers for PET

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1988-01-01

    The history of PET research clearly demonstrates that it is advances in chemistry coupled with a detailed examination of the biochemistry of new radiotracers which has allowed the PET method to be applied to new areas of biology and medicine. Radiotracers whose regional distribution reflects glucose metabolism, neutrotransmitter activity and enzyme activity have all required the development of rapid synthetic methods for the radiotracers themselves and the characterization of their biochemical behavior. This article traces some of the advances in the production of labeled precursors and in radiotracer synthesis and evaluation which have shaped the rapidly expanding application of PET to problems in the neurosciences, in cardiology and in oncology. 54 refs

  8. Mechanism of action in VIVO of some pet radiotracers

    International Nuclear Information System (INIS)

    Sachinidis, J.J.; Egan, G.F.; Berlangieri, S.U.; Scott, A.M.

    1998-01-01

    Full text: Position Emission Tomography (PET) is a technique that utilises position-emitting radiopharmaceuticals to map the physiology, biochemistry and pharmacology of the human body. PET studies range from standard image displays that provide indices of physiological function to complex kinetic analysis methods for absolute quantification. This paper will review some of the important PET radiopharmaceuticals currently produced at the Austin and Repatriation Medical Centre, Melbourne and discuss their mechanism of action in vivo. Depending on their mechanism of action, PET radiopharmaceuticals may be divided into two categories. The first category is non-specific radiotracers which follow a biochemical pathway. The second category is specific radioligands which are involved in an interaction with a receptor transporter or a receptor site. Radiopharmaceuticals from the first category may be assessed using a single or two compartmental plasma-tissue model and allow a measurement of tissue extraction or metabolism.[ 15 O] water is a freely diffusable inert which is used for cerebral blood flow measurement; [ 18 F] FDG which follows the initial phases of glucose metabolism but does not enter the Krebs cycle after phosphorylation and therefore is effectively trapped in the cells, can be used for tissue glucose metabolism measurement in oncology, cardiology and neurology; and [ 18 F]fluoromisonidazole which is a bio-reductive drug that in vivo follows an intracellular reduction pathway, can be used for hypoxic tissue measurement in stroke and tumour evaluation. Radiopharmaceuticals from the second category may be assessed using a three-compartment model: - unmetabolised free ligand in plasma, - free ligand in tissue, - and specially bound ligand in tissue. These radiotracers such as [ 11 C] flumazenil, which is an antagonist with high affinity and selectivity for a central benzodiazepine receptors, are used to study the changes in density or affinity of these receptors

  9. Study of the binding of {sup 114m}In radiotracer to human serum components by ultrafiltration and chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Hulle, M. van; De Cremer, K.; Cornelis, R. [Ghent Rijksuniversiteit (Belgium). Lab. for Analytical Chemistry

    2000-10-01

    The chemical speciation of indium in serum was studied. Ultrafiltration was used to investigate the influence of several buffer systems on the binding characteristics of indium in serum and to study the association of indium with transferrin and albumin. This was performed by means of batch incubation experiments with a {sup 114m}In tracer. Different buffer systems were investigated. A series of bicarbonate, Tris:HCl and HEPES buffers were found to fit for this purpose. Phosphate buffer was not suitable, as it is capable of disrupting the binding between indium and transferrin. Batch ultrafiltration experiments with {sup 114m}In incubated solutions of transferrin and albumin showed that both proteins are capable of binding indium to a high degree. Three chromatographic techniques (SEC, AEC, AC) were used to study the different chemically active species of indium in serum. It is concluded that next to transferrin, albumin is also responsible for the binding and transport of indium in serum. (orig.)

  10. Comparative study of phloem loading radiotracer techniques for in vivo sucrose translocation in non woody and woody plants

    International Nuclear Information System (INIS)

    Kulkarni, Pranav; Pandey, Manish; Suprasanna Penna; Ramteke, Sahadeo

    2017-01-01

    The application of radioisotopes for analysing the in vivo physiological responses in plants is a well known practical approach for the plant physiologists. Physiological difference in woody and non woody plants necessitates the need for universal way of application of radioisotopes to study in vivo sucrose translocation. In this study, grape vine (Vitis vinifera cv. Thomson seedless) and mustard (Brassica juncea cv. Pusa Bold) plants having active source and sink were used as representative system for woody and non woody plants. In present work we applied different strategies for radio activity loading in both boody and non woody plant viz. phloem loading via cut end, direct injection into phloem and activity incorporation through minor vein of leaves (gaseous CO 2 incorporation)

  11. Studies on In-situ Chelation/Supercritical Fluid Extraction of Lanthanides and Actinides Using a Radiotracer Technique

    International Nuclear Information System (INIS)

    Lin, Yuehe; Wu, Hong; Smart, Neil G.; Wai, Chien M.

    2001-01-01

    Radioisotope tracer techniques were used to study the process of in-situ chelation/supercritical fluid extraction(SFE) of La3+ and Lu3+ from solid matrix using mixed ligand hexafluoroacetylacetone (HFA) and tributylphosphate (TBP) as chelating agents. A lab-built SFE extactor was used in this study and the extractor design was optimized based on the experimental results. Quantitative recovery of La and Lu was achieved when the extrator design was optimized. Extraction of uranium from real world samples was also investigated to demonstrate the capability of this chelation/SFE technology for environmental remediation applications. A novel on-line back extraction technique for the recovery of metal ions and regeneration of ligands is also reported.

  12. Parametrisation and empirical model for bedload movement in the multibar coastal zone on the base of field radiotracer study

    International Nuclear Information System (INIS)

    Owczarczyk, A.; Wierzchnicki, R.; Pruszak, Z.

    1999-01-01

    The near-shore zone is the most interesting sea region is coastal engineering. In this region the most effective changes in coastal morphodynamic takes place due to intensive sediment transport generated by waves and currents. The processes occurring in this zone are of great importance for coast protection and hydrotechnic activities as well as recreation. They are extremely complicated due to their stochastic character in the time and space domain. The most valuable information concerning the dynamics of bedload transport and its local character is provided by the field surveys. Such investigations are carried out under natural conditions and take into account the characteristic properties of the region. The subject of the work was the study of bedload movement for the multibar conditions

  13. Chemical vapor generation of silver for atomic absorption spectrometry with the multiatomizer: Radiotracer efficiency study and characterization of silver species

    Energy Technology Data Exchange (ETDEWEB)

    Musil, Stanislav [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Charles University in Prague, Faculty of Science, Dept. of Analytical Chemistry, Albertov 8, 128 43 Prague 2 (Czech Republic); Kratzer, Jan; Vobecky, Miloslav [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Hovorka, Jan [Charles University in Prague, Faculty of Science, Institute for Environmental Studies, Benatska 2, 128 01 Prague 2 (Czech Republic); Benada, Oldrich [Institute of Microbiology of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Matousek, Tomas, E-mail: matousek@biomed.cas.c [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic)

    2009-11-15

    Volatile Ag species were generated in flow injection arrangement from nitric acid environment in the presence of surfactants (Triton X-100 and Antifoam B) and permanent Pd deposits as the reaction modifiers. Atomic absorption spectrometry (AAS) with multiple microflame quartz tube atomizer heated to 900 deg. C was used for atomization; evidence was found for thermal mechanism of atomization. Relative and absolute limits of detection (3sigma, 250 mul sample loop) measured under optimized conditions were: 1.4 mug l{sup -1} and 0.35 ng, respectively. The efficiency of chemical vapor generation (CVG) as well as spatial distribution of residual analyte in the apparatus was studied by {sup 111}Ag radioactive indicator (half-life 7.45 days) of high specific activity. It was found out that 23% of analyte was released into the gaseous phase. However, only 8% was found on filters placed at the entrance to the atomizer due to transport losses. About 40% of analyte remained in waste liquid, whereas the rest was found deposited over the CVG system. Presented study follows the hypothesis that the 'volatile' Ag species are actually metallic nanoparticles formed upon reduction in liquid phase and then released with good efficiency to the gaseous phase. Number/charge size distributions of dry aerosol were determined by Scanning Mobility Particle Sizer. Ag was detected in 40-45 nm particles holding 10 times more charge if compared to Boltzmann equilibrium. At the same time, Ag was also present on 150 nm particles, the main size mode of the CVG generator. The increase of Ag in standards was reflected by proportional increase in particle number/charge for 40-45 nm size particles only. Transmission electron microscopy revealed particles of 8 +- 2 nm sampled from the gaseous phase, which were associated in isolated clusters of few to few tens of nanometres. Ag presence in those particles was confirmed by Energy Dispersive X-ray Spectroscopy (EDS) analysis.

  14. MEMPELAJARI FISIOLOGI PENCEMARAN LINGKUNGAN DENGAN TEHNIK RADIOISOTOP (Study in the Physiology of Environment Pollution Using Radiotracer Method

    Directory of Open Access Journals (Sweden)

    Razak Achmad Hamzah

    2011-11-01

    Full Text Available ABSTRAK Penelitian ini bertujuan untuk mengetahui: 1. Perbedaan kemampuan daya serap tumbuhan air Hydrilla verticillata, Enceng gondok (Eichhomia crassipes dan Kangkung terhadap residu Malathion, menggunakan akuarium (diisi dengan air + Hydrilla Verticillata + Enceng Gondok + Kangkung + Malathion radioisotope 14C. 2. Perbandingan kadar malathion dalam jaringan ikan yang mendapat makanan Hydrilla verticilata dengan yang mendapat makanan kangkung, menggunakan: (akuarium pertama diisi air + Hydrilla Vericillata + ikan mas + Malathion radioisotope 14C; akuarium ke dua diisi air + kangkung + ikan mas + malathion radiisotop 14C. 3. Perbandingan ukuran penyerapan pada jaringan mammalia (tikus yang diberi makan jaringan ikan mas dengan yang diberi makan tumbuhan air (kangkung yang terkontaminasi. Jaringan ikan mas dan kangkung dilakukan pengabuan basah, lalu diberikan masing-masing kepada 30 ekor tikus. Kadar Malathion dari semua percobaan satu, dua dan tiga, diketahui dengan menggunakan alat pencacah Sintilator cair (Liquid Scintillation Spectrometer, LSC- 753 (ALOKA”. Hasil yang didapat dibandingkan dengan menggunakan uji-t Student. Hasil penelitian memperlihatkan bahwa: 1. Hydrilla Verticillata lebih efisien dari pada Enceng Gondok dan Kangkung dalam menyerap residu insektisida malathion dalam air. 2. Ikan yang diberi makan Hydrilla verticillata mengkonsentrasikan malathion lebih tinggi dari pada ikan yang diberi makan kangkung. 3. Mammalia (tikus yang mengkonsumsi daging ikan yang terkontaminasi akan mengkonsentrasikan malathion dalam tubuhnya lebih banyak dari pada tikus yang memakan sayuran (kangkung yang terkontaminasi. ABSTRACT The aim of this study is to determine: 1.The comparison of absorption by aquatic plants Hydrilla verticillata, water hyacinth and water spinach of Malathion insecticide residues in water, (aquarium filled with water + Hydrilla verticillata + water hyacinth + water spinach + 20 mci 14C malathion radioisotope; 2

  15. History and present status of field application of radiotracers, (2)

    International Nuclear Information System (INIS)

    Koyama, Takeo; Shimizu, Makoto.

    1988-01-01

    In the field of agriculture, radiotracers were first used in 1957 in studies for improvement in fertilizing techniques. Techniques were established for accurate measurement of extremely low radioactivity in crops and for the separate determination of the phosphorus in crops of the fertilizer origin and soil origin. Then, RI or stable isotope tracing test methods were developed using 32 P or 15 N to determine the flow and absorption of fertilizers. Other techniques using radiotracers developed in this period served for the construction of maps of the root activity of crops, investigation of the effects of different fertilizers in farms where double-cropping was practised, identification of suitable fertilizers for orange cultivation, development of new fertilizing techniques for Japanese persimmon cultivation, etc. Practically, no field use of radiotracers has been found since 1970. At present, it is prohibited and replaced by other techniques using stable isotopes, etc. In the field fishery, radiotracers have been used for studies of various dynamic phenomena including the flow of water and deposits in the sea, behaviors of fish, food, chain, circulation of chemical substances in the ecological system, etc. (Nogami, K.)

  16. The use of [18F]4-fluorobenzyl iodide (FBI) in PET radiotracer synthesis: model alkylation studies and its application in the design of dopamine D1 and D2 receptor-based imaging agents

    International Nuclear Information System (INIS)

    Mach, R.H.; Elder, S.T.; Morton, T.E.

    1993-01-01

    [ 18 F]4-Fluorobenzyl iodide ([ 18 F]FBI) was prepared, and a series of model alkylation studies were conducted to determine its chemical reactivity toward nitrogen and sulfur nucleophiles of varying nucleophilicities. [ 18 F]FBI was found to react rapidly with secondary amines and anilines to give the corresponding N-[ 18 F]4-fluorobenzyl analogue in high yield. Amides and thiol groups required the use of a base catalyst. The utility of [ 18 F]FBI was documented by investigation of dopamine D 1 and D 2 receptor-based radiotracers. (author)

  17. A philosophy for CNS radiotracer design.

    Science.gov (United States)

    Van de Bittner, Genevieve C; Ricq, Emily L; Hooker, Jacob M

    2014-10-21

    Decades after its discovery, positron emission tomography (PET) remains the premier tool for imaging neurochemistry in living humans. Technological improvements in radiolabeling methods, camera design, and image analysis have kept PET in the forefront. In addition, the use of PET imaging has expanded because researchers have developed new radiotracers that visualize receptors, transporters, enzymes, and other molecular targets within the human brain. However, of the thousands of proteins in the central nervous system (CNS), researchers have successfully imaged fewer than 40 human proteins. To address the critical need for new radiotracers, this Account expounds on the decisions, strategies, and pitfalls of CNS radiotracer development based on our current experience in this area. We discuss the five key components of radiotracer development for human imaging: choosing a biomedical question, selection of a biological target, design of the radiotracer chemical structure, evaluation of candidate radiotracers, and analysis of preclinical imaging. It is particularly important to analyze the market of scientists or companies who might use a new radiotracer and carefully select a relevant biomedical question(s) for that audience. In the selection of a specific biological target, we emphasize how target localization and identity can constrain this process and discuss the optimal target density and affinity ratios needed for binding-based radiotracers. In addition, we discuss various PET test-retest variability requirements for monitoring changes in density, occupancy, or functionality for new radiotracers. In the synthesis of new radiotracer structures, high-throughput, modular syntheses have proved valuable, and these processes provide compounds with sites for late-stage radioisotope installation. As a result, researchers can manage the time constraints associated with the limited half-lives of isotopes. In order to evaluate brain uptake, a number of methods are available

  18. Chemistry and biology of radiotracers that target changes in sympathetic and parasympathetic nervous systems in heart disease.

    Science.gov (United States)

    Eckelman, William C; Dilsizian, Vasken

    2015-06-01

    Following the discovery of the sympathetic and parasympathetic nervous system, numerous adrenoceptor drugs were radiolabeled and potent radioligands were prepared in order to image the β-adrenergic and the muscarinic systems. But the greatest effort has been in preparing noradrenaline analogs, such as norepinephrine, (11)C-metahydroxyephedrine, and (123)I-metaiodobenzylguanidine that measure cardiac sympathetic nerve varicosities. Given the technical and clinical challenges in designing and validating targeted adrenoceptor-binding radiotracers, namely the heavily weighted flow dependence and relatively low target-to-background ratio, both requiring complicated mathematic analysis, and the inability of targeted adrenoceptor radioligands to have an impact on clinical care of heart disease, the emphasis has been on radioligands monitoring the norepinephrine pathway. The chemistry and biology of such radiotracers, and the clinical and prognostic impact of these innervation imaging studies in patients with heart disease, are examined. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  19. Clinical variables in radiotracer biodistributions

    International Nuclear Information System (INIS)

    Lentle, B.C.; Scott, J.R.; Schmidt, R.P.; Noujaim, A.A.

    1981-01-01

    Numerous iatrogenic causes of altered radiotracer biodistributions have been described. Cancer chemotherapy is a particularly potent cause of changed biodistributions while even a trivial matter such as preparing the skin with an iodine containing antiseptic may cause displacement of technetium from its compounds. In the blocking of thyroid uptake of radioiodines, there is good precedent for the manipulation of regional tissue dosimetry. It is possible to go beyond the mere cataloguing of these effects to look creatively at the subject of comparative tissue biodistributions and hence comparative dosimetry. Effects such as the clinical observation of the interference by cis-platinum with the usual biodistribution of radio-gallium suggests that such compounds can be used as probes each to lead to a better understanding of the mechanism of action of the other

  20. Radiotracer injector: An Industrial Application (RIIA)

    International Nuclear Information System (INIS)

    Noraishah Othman; Mohd Arif Hamzah; Fadil Ismail; Nurliyana Abdullah

    2011-01-01

    The radiotracer injector is meant for transferring liquid radiotracer in the system for industrial radiotracer application with minimal radiation exposure to the operator. The motivation of its invention is coming from the experience of the workers who are very concern about the radiation safety while handling with the radioactive source. The idea ensuring the operation while handling the radioactive source is fast and safe without interrupting the efficiency and efficacy of the process. Thus, semi automated device assisting with pneumatic technology is applied for its invention. (author)

  1. Radiotracer residence time distribution method for industrial and environmental applications. Material for education and on-the-job training for practitioners of radiotracer technology

    International Nuclear Information System (INIS)

    2008-01-01

    The International Atomic Energy Agency (IAEA) plays a major role in facilitating the transfer of the radiotracer technology to developing Member States. The major radiotracer techniques have been implemented through IAEA technical cooperation projects and adopted by many Member States. The expertise and knowledge gained should be preserved. The sustainability of technology and knowledge preservation calls for creation of young specialists and for continuing good practices. As a part of its involvement in human resource development, the IAEA is aware of the important need to prepare standard syllabi and training course materials for the education of specialists in different fields of nuclear technologies. This training course material is intended for the cultivation of radiotracer specialists and for continuing technical education of radiotracer practitioners worldwide. The wide interest in radiotracer technology has created the need for high level professional education and training in this field, which are not necessarily covered by traditional university courses. Radiotracers are playing more and more important roles in industry. These roles will continue to expand, especially if students and engineers are exposed in their academic training to the many possibilities for using this tool in research, development and applications. Besides educational purposes, this publication will assist developing Member States in establishing their quality control and accreditation systems. This publication is based on lecture notes and practical works delivered by many experts in IAEA-supported activities. Lectures, papers, case studies and software were reviewed by a number of specialists in several meetings

  2. Quality control and analysis of radiotracer compounds

    International Nuclear Information System (INIS)

    Sheppard, G.; Thomson, R.

    1977-01-01

    Special emphasis was on the problems and errors possible in quality control and analysis. The principles underlying quality control were outlined, and analytical techniques applicable to radiotracers were described. Chapter concluded with a selection of examples showing the effects of impurities on the use of radiotracers. The subject of quality control and analysis was treated from the viewpoint of the user and those research workers who need to synthesize and analyze their own radiochemicals. The quality characteristics for radiotracers are of two kinds, valuable or attributive. These were discussed in the chapter. For counting low radioactive concentration, scintillation techniques are in general use, whereas ionization techniques are now used mainly for the measurement of high radioactive concentrations or large quantities of radioactivity, for scanning chromatograms, and a number of very specific purposes. Determination of radionuclidic purity was discussed. Use of radiotracers in pharmaceuticals were presented. 4 figures, 6 tables

  3. Impurity analysis in EC-99mTC radiotracer using chromatographic techniques

    International Nuclear Information System (INIS)

    Almeida, E.V.; Fukumori, N.T.O.; Mengatti, J.; Silva, C.P.G.; Matsuda, M.M.N.

    2008-01-01

    The objective of this study was to develop two chromatographic methods of impurity analysis in radiotracer 99m Tc-EC: the Thin Layer Chromatography (TLC) and the High Performance Liquid Chromatography Reversed Phase (HPLC-RP)

  4. Application of 99mTc-DTPA Radiotracer in Persian Cat's Renal ...

    African Journals Online (AJOL)

    Keywords: Kidney, Persian cat, Radiotracer, Scintigraphy, Technetium-99m diethylene triamine pentacaetic acid ... tracer can be detected in the body by medical equipment .... studies, such as kidney failure, allergic reactions and fatal side ...

  5. Current status and trends of cooperation on radiotracer and NCS technologies

    Energy Technology Data Exchange (ETDEWEB)

    Thereska, J. [International Atomic Energy Agency, Vienna (Austria). Industrial Applications and Chemistry Section

    1997-10-01

    Relevant target areas for radiotracer and neutronic control system (NCS) applications are defined. The petroleum and petrochemical industries, mineral processing and waste-water treatment sectors are identified as the most appropriate beneficiaries. The new CRP on `Radiotracer technology for engineering unit operations studies and unit process optimisation` aims to improve the radiotracer methodology, including new radiotracers, development of expert systems, new software for data processing with finite element techniques for flow structure visualisation, as well as to formulate guidelines for problem solving of complex processes. The organisation of a CRP on `Multibeam radiogauging for multi-phase systems studies` to further develop and refine nucleonic gauge methodology and technology, including development of expert systems for optimal design and calibration, quality control according to ISO standards, emerging new applications, and formulation of guidelines and software for on line measurement of multi-phase system parameters of complex processes will be discussed in the near future

  6. Current status and trends of cooperation on radiotracer and NCS technologies

    International Nuclear Information System (INIS)

    Thereska, J.

    1997-01-01

    Relevant target areas for radiotracer and neutronic control system (NCS) applications are defined. The petroleum and petrochemical industries, mineral processing and waste-water treatment sectors are identified as the most appropriate beneficiaries. The new CRP on 'Radiotracer technology for engineering unit operations studies and unit process optimisation' aims to improve the radiotracer methodology, including new radiotracers, development of expert systems, new software for data processing with finite element techniques for flow structure visualisation, as well as to formulate guidelines for problem solving of complex processes. The organisation of a CRP on 'Multibeam radiogauging for multi-phase systems studies' to further develop and refine nucleonic gauge methodology and technology, including development of expert systems for optimal design and calibration, quality control according to ISO standards, emerging new applications, and formulation of guidelines and software for on line measurement of multi-phase system parameters of complex processes will be discussed in the near future

  7. Clinical variables in radiotracer biodistributions

    International Nuclear Information System (INIS)

    Lentle, B.C.; Scott, J.R.; Schmidt, R.P.; Noujaim, A.A.

    1981-01-01

    Radionuclide dosimetry must, by its nature, define tissue irradiation in terms of mean exposure in a population of a statistically acceptable size. In the daily practice of clinical nuclear medicine there are, however, quite large variations in the biodistribution of tracers and thus in resulting radiation doses. Age is a variable, particularly in respect of bone-seeking tracers. Sex imposes variations in radiation dose on account of the differing anatomical configurations of the gonads. Breast uptake and excretion of certain tracers in women are additional variables. Activity and occupation are occasional variables. Numerous iatrogenic causes of altered radiotracer biodistributions have been described. Cancer chemotherapy is a particularly potent cause of changed biodistributions while even a trivial matter such as preparing the skin with an iodine containing antiseptic may cause displacement of technetium from its compounds. In the blocking of thyroid uptake of radioiodines, there is good precedent for the manipulation of regional tissue dosimetry. It is possible to go beyond the mere cataloguing of these effects to look creatively at the subject of comparative tissue biodistributions and hence comparative dosimetry. Effects such as the clinical observation of the interference by cis-platinum with the usual biodistribution of radio-gallium suggest that such compounds can be used as probes each to lead to a better understanding of the mechanism of action of the other

  8. Leak detection in a high-pressure heat exchanger system in a refinery using radiotracer technique

    International Nuclear Information System (INIS)

    Samantray, J.S.; Sunil Goswami; Sharma, V.K.; Jayashree Biswal; Pant, H.J.

    2014-01-01

    A radiotracer investigation was carried out in a diesel hydrotreater (DHDT) unit in a refinery for leak detection in a breech-lock heat exchanger system. The main objectives of the study were to identify the leaking heat exchanger in a system with six heat exchangers and estimate the leak rate. Bromine-82 as dibromobiphenyl was selected and used as radiotracer for the investigation. The radiotracer was instantaneously injected into the suction end of the feed pump line to the heat exchanger of the DHDT unit. The movement of the tracer was measured at strategically selected locations using NaI(Tl) scintillation detectors. Based upon the results of the radiotracer investigation, it was found that out of six heat exchangers, exchanger E-1F was leaking. (author)

  9. The uses of radiotracers in the life sciences

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Thomas J [TRIUMF, Vancouver (Canada)

    2009-01-15

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination.

  10. The uses of radiotracers in the life sciences

    Science.gov (United States)

    Ruth, Thomas J.

    2009-01-01

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination.

  11. The uses of radiotracers in the life sciences

    International Nuclear Information System (INIS)

    Ruth, Thomas J

    2009-01-01

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination

  12. Diagnosing plant pipeline system performance using radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kasban, H.; Ali, Elsayed H.; Arafa, H. [Engineering Department, Nuclear Research Center, Atomic Energy Authority, Inshas (Egypt)

    2017-02-15

    This study presents an experimental work in a petrochemical company for scanning a buried pipeline using Tc{sup 99m} radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, Tc{sup 99m} radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

  13. Radiotracers for SPECT imaging. Current scenario and future prospects

    International Nuclear Information System (INIS)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S.

    2012-01-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [ 123 I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [ 123 I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also makes them more

  14. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S. [GE Healthcare Medical Diagnostics, John F. Welch Technology Center, Bangalore (India).; Bhalla, R.; Pickett, R.; Luthra, S.K. [GE Healthcare Medical Diagnostics, The Grove Centre, Amersham (United Kingdom)

    2012-07-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [{sup 123}I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [{sup 123}I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also

  15. Hydrodynamic characteristics of high speed settling clarifiers by radiotracer method

    International Nuclear Information System (INIS)

    Griffith Martinez, Jose; Damera Martinez, A.; Ramos Espinosa, K.

    2003-01-01

    Results achieved in the evaluation of two high-speed settling cane juice Clarifiers, one denominated ICINAZ The Express and the other one a modified SRI, both located at the sugar factory Orlando Gonzalez employing the well established radiotracer method (Tc-99m) are presented Several trials performed simultaneously at the two Clarifiers demonstrated that the modified SRI was capable to assimilate the whole flow capacity of the factory with adequate characteristic of the pattern flux and residence time in the environment of 1 hour. In the other side, ICINAZ The Express Clarifier could only work at relative low flow capacity of the factory with residence time closely to the two hours and achieving occasionally a pattern flux seriously affected by fluctuations in the milling process. The non-availability of a flow meter did not allow to extract more information related to some pattern flux anomalies, nevertheless, the radiotracer method was able to detect certain differences between the two clear juice outlet of the modified SRI Clarifier, probably due some problems in the construction of this equipment. This fact so as other goals achieved in this work, show once more the potentiality of the radiotracer method for this type of study related to the hydrodynamic characteristics of industrial facilities. (Author)

  16. Biosorptive behaviour of Mango (Mangifera indica) and Neem (Azadirachta indica) bark for Hg2+, Cr3+ and Cd2+ toxic ions from aqueous solutions: a radiotracer study

    International Nuclear Information System (INIS)

    Tiwari, Diwakar; Mishra, Shuddhodan P.; Mishra, Manisha; Dubey, R.S.

    1999-01-01

    Biosorption of Hg 2+ and Cr 3+ on dead biomass Mango (Mangifera indica) and Neem (Azadirachta indica) bark has been assessed at micro to tracer level concentrations from aqueous solutions employing the 'radiotracer technique'. A high level of uptake of metal ions on these solid surfaces occurs within ca. 4 h of contact time reaching apparent saturation. The increase of sorptive concentration (10 -8 to 10 -2 mol dm -3 ), temperature (293-323 K) and pH (ca. 3 to 10) favoured the removal process of these ions; but in the case of Hg 2+ on Neem bark, there was seemingly no temperature effect. The uptake process follows first order rate law and obeys the Freundlich adsorption isotherm. Added anions and cations in the bulk solution inhibit to some extent the removal of these toxic ions. Similarly the inhibition in the uptake was also observed when both biomasses were irradiated by neutron and γ-rays prior to being employed as sorbents. No significant sorption of Cd 2+ was observed on these dead biomass solid surfaces under various physical-chemical conditions

  17. Industrial applications of radiotracers in Indonesia

    International Nuclear Information System (INIS)

    Wandowo

    1994-01-01

    Applications of isotopes and radiation have been developed since 1970 at the Centre for Application of Isotopes and Radiation, National Atomic Energy Agency or BATAN. The scope of applications cover various fields, namely, agriculture, medicine, hydrology, sedimentology and industry. The use of radiotracers prove to be very beneficial for problem solving in industrial process plants and this technique will continuously be promoted by BATAN to industries in Indonesia. Several examples of radiotracer applications in industries which have been carried out by the Group of Industry of the Centre for Application of Isotopes and Radiation are presented. (author). 7 refs., 4 figs., 1 tab

  18. Synthesis of new radiotracers for tuberculosis diagnosis

    International Nuclear Information System (INIS)

    Keskes, Badis

    2009-01-01

    Tuberculosis remains a worldwide health problem and its diagnosis presents a major challenge. The examinations currently employed are little appreciable and so far there is no reliable diagnosis test. These last years, the development of the new radiopharmaceuticals, referred to diagnosis, has revived interest in the search for new molecules with a tropism to a particular disease. Thanks to this field, which lies at the interface of organic and organometallic chemistry, nuclear medicine and biology, we have been led to synthesize a technetium radiotracer linked to isoniazid. For the identification of this radiotracer, we used its similar rhenium model. (Author)

  19. Radiotracer studies on the fate and transformation of pesticide residues in the environment and food chains. Part of a coordinated programme on isotopic-tracer-aided studies of chemical residues in cotton seed, feed, oil and related products

    International Nuclear Information System (INIS)

    Lee, S.R.

    1980-10-01

    The magnitude and fate of some pesticide chemicals in Korean foods were studied with particular reference to oil-bearing crops and related products. Application of the chemicals was made under conditions of actual agricultural practice. Analytical methodologies included nuclear activation, gas chromatographic, spectrophotometric and radiotracer techniques. Residues of benzene hexachloride, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin and DDT found in refined vegetable oil samples were below or within the tolerance limits set by international organizations and as such, these are unlikely to present any toxicological hazard to the consumer. Also, residues of the herbicides nitrogen, alachlor and butachlor applied to oil-bearing crops were not detected in the seeds. Studies on 14 C-BHC residues in rice revealed that polishing and washing play an important role in removing a considerable portion of the residue. Data on the arsenic-containing neoasozine residues suggest that the products consumed by the human (grain and oil) contained residues below the tolerance limit and are unlikely to present any toxicological hazard to the consumer. On the other hand, relatively high arsenic concentrations (2.2 mg/kg) were found in the cake (serving as animal feed) and should be carefully evaluated in the light of toxicological data

  20. Radiotracer applications in industry - A guidebook

    International Nuclear Information System (INIS)

    2004-01-01

    The objective of this guidebook is to provide the radiotracer practitioner with practical, experience based information about all the facets of an investigation: design, planning, implementation, data treatment and interpretation of results. It is aimed at clearly identifying the questions that need to be asked at each stage of the investigation and, as comprehensively as possible, to either provide the answers to those questions or identify appropriate works of reference. The primary focus is on the methodology of radio tracing. Discussed aspects of the methodology are: tracer selection and optimization, methods of tracer injection, detection and measurement of radiation, data treatment and filtering including identification of available software, data analysis, interpretation and modelling. An early consideration in designing an investigation is selection of the tracer. The criteria of critical importance are that (1) the tracer must be compatible with the stream to be traced and (2) its behaviour must be representative of that stream. The first decision to make is whether to use a radioactive tracer or some alternative type. Generally, if the objectives of the investigation can be achieved using a non-radioactive tracer and without incurring disproportionate costs, then that tracer should be used. However, as will become apparent from the case studies presented, there are many problems that can be investigated only by using a radiotracer. In these cases it is necessary to choose a tracer based on the following selection criteria: type of radiation emitted: alpha particle, beta particle or gamma ray, half-life of the radionuclide, energy of the emitted radiation and optimization of the activity injected. The methodology reviewed considers the most commonly used radioisotopes for tracing solid materials, aqueous solutions, organic liquids and gaseous phases. The main emphasis is on the practical aspects of the technology. Various types of injection system are

  1. Production of 41Ar and 79Kr gaseous radiotracers for industrial applications

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Jagadeesan, K.C.; Shivarudrappa, V.; Sharma, V.K.; Chitra, S.

    2007-01-01

    Radiotracers are extensively used in many industries for trouble shooting and optimization of process parameters leading to considerable savings in time and huge economic benefits. In chemical and petrochemical industries different gases and vapours flowing in the conversion reactors play a major role in the final production. Gaseous radiotracers are ideal to study hydrodynamics of gas phases in process vessels. 41 Ar and 79 Kr are the preferred gaseous radiotracers for such studies. Owing to the increase in demand from Indian industries for gas phase radiotracers, efforts have been made to produce 41 Ar and 79 Kr indigenously by irradiation of 40 Ar and enriched 78 Kr gaseous targets in research reactors. Prequalification of the containers used, safety aspects concerning accidental rupture and mandatory tests necessary for irradiation of gaseous targets in the reactors have been studied. The paper describes some of the important safety aspects involved and the results of trial irradiations on the production of 41 Ar and 79 Kr radiotracers. Standardization of suitable assay protocols for their regular production and supply for applications in industries is also described. (author)

  2. Radiotracer study of the fate and persistence of organic fungicides used as seed dressing on grain. Part of a coordinated programme of isotopic tracer aided studies of foreign chemical residues in food

    International Nuclear Information System (INIS)

    Raghu, K.

    1976-12-01

    Radiotracer-aided studies were made of the fate and persistence of Thiram, used as a seed dresser and Ziram used as a foliar spray and their effects on soil fertility and plant growth. Thiram applied as a seed dresser had no inhibitory effect on (a) seedling height and rhizosphere microflora of barley, (b) soil microflora, (c) nodulation of cowpea plants. The uptake of 35 S radioactivity at 20-day stage was 0.3% of the total applied as 35 S thiram. Thiram as such was not present in barley or maize plants at any of the growth stages up to grain formulation but was converted into DDC-glucoside, DDC-alamine, fungicide X and TTCA. The quantity of these decreased in barley and maize with time and were in negligible amounts at grain stage. The sulphur from thiram found its way into sulphur-containing metabolites like protein, amino acids, sulfolipids, etc. Ziram, a foliar spray fungicide was also converted into DDC-conjugates and the amounts of residue were negligible at harvest time both in rice and groundnut. Thiram degraded more rapidly in unsterilized soils than in sterilized soil, thus indicating biodegradation. The fungicide is more persistent in sandy than in laterite and alluvial soils. Microbial degradation of thiram was shown by comparing persistence of 35 S thiram in sterilized and unsterilized soils. A Pseudomonas sp. isolated from soil was capable of degrading thiram and ziram and DDC-aminobutyric acid was the major polar metabolite. The appearance of similar degradation products with these dialkyl dithiocarbamates indicated that they have some common metabolic pathway

  3. The application of radiotracer technique for preconcentration neutron activation analysis

    International Nuclear Information System (INIS)

    Wang Xiaolin; Chen Yinliang; Sun Ying; Fu Yibei

    1995-01-01

    The application of radiotracer technique for preconcentration neutron activation analysis (Pre-NAA) are studied and the method for determination of chemical yield of Pre-NAA is developed. This method has been applied to determination of gold, iridium and rhenium in steel and rock samples and the contents of noble metal are in the range of 1-20 ng·g -1 (sample). In addition, the accuracy difference caused by determination of chemical yield between RNAA and Pre-NAA are also discussed

  4. Green chemistry using radiotracers at SINP

    International Nuclear Information System (INIS)

    Lahiri, Susanta

    2006-01-01

    Green chemistry is utilization of set of principles, which restricts the use, or generation of hazardous substances. In this aim, it is necessary to develop alternative methods, or to find greener reagents for minimum utilization of environmentally hostile substances. Radiotracers can be effectively utilized for development of such methods. This article describes the current status of Green Chemistry research using accelerator/reactor produced radionuclides at Saha Institute of Nuclear Physics, Kolkata, India. (author)

  5. Regulatory requirements for fluorine 18-labelled radiotracers

    International Nuclear Information System (INIS)

    Prigent, A.

    2005-01-01

    Although European and French regulations define radiopharmaceuticals and their different conditions for use, there is no legal status of the radiotracer. Radiotracer is commonly known as a molecular entity administered in tracer doses, that means at very low masses (e.g., nano-mol amounts) and, consequently, without any pharmacological effect. A radiotracer can meet the specifications of either a radiochemical (usually restricted to research in animal models) or a radiopharmaceutical (human use for diagnostic imaging or research projects). Besides the 'proprietary medicinal product', different status have been defined to allow other uses in humans, referring to 'magistral formula' preparation, 'officinal formula' preparation, investigational medicinal product for clinical trials, or to a radiopharmaceutical with a 'patient named authorization'. However, because of the short half-life of fluorine 18 and expanding development of molecular imaging techniques using positron emission tomography (PET), the current regulation is sometimes considered as inappropriate with regard to the small-size production required for such on-site manufactured radiopharmaceuticals. It is often claimed that it could be very difficult to comply with the current Good Manufactured Practice (cGMP). As previously done for radiopharmaceuticals based on monoclonal antibodies, specific adjustments for PET radiopharmaceuticals are under discussion and the 'note for guidance on radiopharmaceuticals' will be soon revised by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMEA). In many cases, a status of 'magistral' product might be attributed to a PET radiopharmaceutical manufactured according with European Pharmacopoeia monographs. (author)

  6. Application of radiotracer methods in streamflow measurements

    International Nuclear Information System (INIS)

    Dincer, T.

    1967-01-01

    An attempt is made to evaluate methods using radiotracers in streamflow measurements. The basic principles of the tracer method are explained and background information given. Radiotracers used in stream discharge measurements are discussed and measurements made by different research workers are described. Problems such as adsorption of the tracer and the mixing length are discussed and the potential use of the radioisotopes as tracer in the routine stream-gauging work is evaluated. It is concluded that, at the present stage of development, radiotracer methods do not seem to be ready for routine use in stream-gauging work, and can only be used in some special cases. For gamma-emitting radioisotopes there are problems related to safety, transport and injection which should be solved. Tritium, though a very attractive tracer in some respects, has the disadvantages of having a relatively long half-life and of disturbing the natural tritium levels in the region. Finally, an attempt is made to define the objectives of the research in the field of application of radioisotopes in hydrometry. (author)

  7. Research of pharmacokinetics of L-threonate calcium with 45Ca radiotrace

    International Nuclear Information System (INIS)

    Tong Jian; Niu Huisheng; Li Huaifen

    2001-01-01

    The pharmacokinetics of calcium in L-threonate calcium is studied by radiotrace method. The results show the relationship between drug-time curve, pharmacokinetics parameters and dosage are positive correlation, and calcium distributes in important tissues such as stomach, intestines, blood and bone. In 24 hours, about 40% calcium is drained in urine, 30% calcium is evacuated in feces, 10%-20% calcium deposit in blood or bone. The radiotrace method is a kind of special, sensitive, accurate method of testing calcium metabolism

  8. [{sup 11}C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Alan A., E-mail: alan.wilson@camhpet.c [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Garcia, Armando; Parkes, Jun [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Houle, Sylvain [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Tong, Junchao [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8 (Canada); Vasdev, Neil [PET Centre, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2011-02-15

    Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([{sup 11}C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [{sup 11}C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [{sup 11}C]CURB was irreversibly bound to FAAH

  9. [11C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

    International Nuclear Information System (INIS)

    Wilson, Alan A.; Garcia, Armando; Parkes, Jun; Houle, Sylvain; Tong, Junchao; Vasdev, Neil

    2011-01-01

    Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([ 11 C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [ 11 C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [ 11 C]CURB was irreversibly bound to FAAH. Conclusions

  10. Radiotracer studies on the degradation and dissipation of lindane under Malaysian environment. Part of a coordinated programme on the fate of persistent pesticides in the tropics, using radioisotopes

    International Nuclear Information System (INIS)

    Jamaluddin, M.D.

    1983-11-01

    A protocol was designed to provide information on rates of dissipation and degradation of lindane (γ-isomer of 1,2,3,4,5,6-hexachlorocyclohexane), a chemical used in Malaysia for pest control in rice paddies. The parameters studied included adsorption to three Malaysian soils, volatilization, degradation, dissipation through leaching and terminal residues in the grain. 14 C-labelled lindane was used after mixing with appropriate concentrations of the cold chemical. Standard nuclear techniques such as liquid scintillation counting and radiochromatography were applied. Adsorption of lindane to soil decreased in the order clay>sandy clay>loam>sandy loam. Volatilization of lindane was proportional to the chemical concentration and was more rapid in non-flooded and sterilized flooded soils. Under flooding conditions, microorganismal activities seem to play a dominant role in the disappearance, possibly degradation, of lindane. The half-life of lindane in non-sterilized flooded soil ranged from 10.5 to 34.5 days depending on the type of soil. The chemical residue in the grain was well below the maximum residue level. This is part of a project designed to provide data on the degradation and dissipation of lindane in the Malaysian environment in an attempt to pass a realistic judgement as to its persistence

  11. Radiotracer aided optimization of batch mixing of solids

    International Nuclear Information System (INIS)

    Kolar, Z.I.; Bergh, W.J.B. van den; Scarlett, B.

    1989-01-01

    A method for the determination of mixing times has been developed and tested in a model Nauta mixer filled with sand. 128 I-labelled sand particles were used as radiotracer and the progress of mixing was monitored with two radiation detectors located externally. The variance of the radiation intensity decreases with time until a constant value is reached indicating an equilibrium mixture of tracer and sand. The time necessary to achieve this condition (mixing time) appears to be dependent on the rotational speed of the hopper as well as the screw of the mixer. Optimal mixing performance (shortest mixing time) corresponds to the maximal rotational speeds of both rotating parts of the mixer. (author)

  12. Synthesis of a new technetium brain radiotracer

    International Nuclear Information System (INIS)

    El Aissi, Radhia

    2009-01-01

    The radiological diagnosis of brain diseases, including neurodegenerative ones, is still difficult because of the absence of specific biological markers. These diseases are then increasingly the subject of researches and new experiments. The biodistribution of a new cytectrenes-aniline derivative, having a lipophilic character and low molecular weight, showed a prolonged brain retention and a specific tissue distribution of the hippocampus. This radiotracer could contribute to establish early diagnosis of neurodegenerative diseases thanks to its affinity with a serotonin receptors-rich region. (Author)

  13. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  14. Development of a system for real-time measurements of metabolite transport in plants using short-lived positron-emitting radiotracers

    Science.gov (United States)

    Kiser, Matthew R.

    Over the past 200 years, the Earth's atmospheric carbon dioxide (CO 2) concentration has increased by more than 35%, and climate experts predict that CO2 levels may double by the end of this century. Understanding the mechanisms of resource management in plants is fundamental for predicting how plants will respond to the increase in atmospheric CO 2. Plant productivity sustains life on Earth and is a principal component of the planet's system that regulates atmospheric CO2 concentration. As such, one of the central goals of plant science is to understand the regulatory mechanisms of plant growth in a changing environment. Short-lived positron-emitting radiotracer techniques provide time-dependent data that are critical for developing models of metabolite transport and resource distribution in plants and their microenvironments. To better understand the effects of environmental changes on resource transport and allocation in plants, we have developed a system for real-time measurements of rnetabolite transport in plants using short-lived positron-emitting radio-tracers. This thesis project includes the design, construction, and demonstration of the capabilities of this system for performing real-time measurements of metabolite transport in plants. The short-lived radiotracer system described in this dissertation takes advantage of the combined capabilities and close proximity of two research facilities at. Duke University: the Triangle Universities Nuclear Laboratory (TUNL) and the Duke University Phytotron, which are separated by approximately 100 meters. The short-lived positron-emitting radioisotopes are generated using the 10-MV tandem Van de Graaff accelerator located in the main TUNL building, which provides the capability of producing short-lived positron-emitting isotopes such as carbon-11 (11C: 20 minute half-life), nitrogen-13 (13N; 10 minute half-life), fluorine-18 (18F; 110 minute half-life), and oxygen-15 (15O; 2 minute half-life). The radioisotopes may

  15. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M., E-mail: anacamiqui@gmail.com, E-mail: egoncalves@con.ufrj.br, E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  16. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    International Nuclear Information System (INIS)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M.

    2017-01-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  17. The influence of molecular weight in radiotracers of inflamators processes

    International Nuclear Information System (INIS)

    Mesa Duennas, N.; Zayas Crespo, F.; Piedra Mazorra, J.; Diaz Barreto, M; Rodriguez Alfonso, M.E.; Perez Fuentes, A.

    2004-01-01

    Four 99mTc-radiopharmaceuticals (RPs) were compared as a radiotracers of inflammatory process. The RPs were divided in two groups according to their molecular weights and nature. One group included the human IgG and the ior t3 MoAb (anti-CD3), another included the Ciprofloxacine and the DMSA. The RPs were studied by different quality controls, and a biodistribution study in an aseptic inflammatory model made by steril Carragenin. The results obtained in the reduction of the immunoglobulins with 2-mercaptoethanol and sodium metabisulphite demonstrated that both reducing agents were equivalent, because the radiochemical purity obtained were similar and independent of the immunoglobulins. The biodistribution demonstrated a higher incorporation for the radiopharmaceuticals of high molecular weight, and the highest values were obtained with the 2-mercaptoethanol

  18. Vulnerability of positron emission tomography radiotracers to endogenous competition

    International Nuclear Information System (INIS)

    Laruelle, M.; Huang, Y.

    2001-01-01

    PET and SPECT neuro receptor imaging techniques combined with pharmacological challenges have been introduce to measure acute fluctuations of synaptic dopamine (DA) concentrations in the living human brain. Changes in the in vivo binding of radioligands following manipulation of transmitter levels are generally believed to be driven by binding competition between the radioligand and neurotransmitter. This imaging modality has been very successful in the study of DA transmission at D2 receptors. Yet, the extension of this technique to the study of other neurotransmitter systems has proven difficult. This paper reviews recent evidence suggesting that simple binding competition might not be the only phenomenon regulating transmitter-radioligand interactions in vivo, and examines emerging data indicating that receptor trafficking might also be involved. A better understanding of the mechanisms underlying these interactions should facilitate the development of PET and SPECT radiotracers suitable for the reporting of synaptic transmitter levels

  19. Vulnerability of positron emission tomography radiotracers to endogenous competition

    Energy Technology Data Exchange (ETDEWEB)

    Laruelle, M.; Huang, Y. [Columbia University College of Physicians and Surgeons and State Psychiatric Institute, Dept. of Psychiatry and Radiology, New York, NY (United States)

    2001-06-01

    PET and SPECT neuro receptor imaging techniques combined with pharmacological challenges have been introduce to measure acute fluctuations of synaptic dopamine (DA) concentrations in the living human brain. Changes in the in vivo binding of radioligands following manipulation of transmitter levels are generally believed to be driven by binding competition between the radioligand and neurotransmitter. This imaging modality has been very successful in the study of DA transmission at D2 receptors. Yet, the extension of this technique to the study of other neurotransmitter systems has proven difficult. This paper reviews recent evidence suggesting that simple binding competition might not be the only phenomenon regulating transmitter-radioligand interactions in vivo, and examines emerging data indicating that receptor trafficking might also be involved. A better understanding of the mechanisms underlying these interactions should facilitate the development of PET and SPECT radiotracers suitable for the reporting of synaptic transmitter levels.

  20. Comparison of two peptide radiotracers for prostate carcinoma targeting

    Directory of Open Access Journals (Sweden)

    Bluma Linkowski Faintuch

    2012-01-01

    Full Text Available OBJECTIVES: Scintigraphy is generally not the first choice treatment for prostate cancer, although successful studies using bombesin analog radiopeptides have been performed. Recently, a novel peptide obtained using a phage display library demonstrated an affinity for prostate tumor cells. The aim of this study was to compare the use of a bombesin analog to that of a phage display library peptide (DUP-1 radiolabeled with technetium-99m for the treatment of prostate carcinoma. The peptides were first conjugated to S-acetyl-MAG3 with a 6-carbon spacer, namely aminohexanoic acid. METHODS: The technetium-99m labeling required a sodium tartrate buffer. Radiochemical evaluation was performed using ITLC and was confirmed by high-performance liquid chromatography. The coefficient partition was determined, and in vitro studies were performed using human prostate tumor cells. Biodistribution was evaluated in healthy animals at various time points and also in mice bearing tumors. RESULTS: The radiochemical purity of both radiotracers was greater than 95%. The DUP-1 tracer was more hydrophilic (log P = -2.41 than the bombesin tracer (log P = -0.39. The biodistribution evaluation confirmed this hydrophilicity by revealing the greater kidney uptake of DUP-1. The bombesin concentration in the pancreas was greater than that of DUP-1 due to specific gastrin-releasing peptide receptors. Bombesin internalization occurred for 78.32% of the total binding in tumor cells. The DUP-1 tracer showed very low binding to tumor cells during the in vitro evaluation, although tumor uptake for both tracers was similar. The tumors were primarily blocked by DUP1 and the bombesin radiotracer primarily targeted the pancreas. CONCLUSION: Further studies with the radiolabeled DUP-1 peptide are recommended. With further structural changes, this molecule could become an efficient alternative tracer for prostate tumor diagnosis.

  1. Preclinical acute toxicity studies and rodent-based dosimetry estimates of the novel sigma-1 receptor radiotracer [18F]FPS

    International Nuclear Information System (INIS)

    Waterhouse, Rikki N.; Stabin, Michael G.; Page, John G.

    2003-01-01

    [ 18 F]1-(Fluoropropyl)-4-[(4-cyanophenoxy)methyl]piperidine ([ 18 F]FPS) is a novel high affinity (KD = 0.5 nM) sigma receptor radioligand that exhibits saturable and selective in vivo binding to sigma receptors in rats, mice and non-human primates. In order to support an IND application for the characterization of [ 18 F]FPS through PET imaging studies in humans, single organ and whole body radiation adsorbed doses associated with [ 18 F]FPS injection were estimated from distribution data obtained in rats. In addition, acute toxicity studies were conducted in rats and rabbits and limited toxicity analyses were performed in dogs. Radiation dosimetry estimates obtained using rat biodistribution analysis of [ 18 F]FPS suggest that most organs would receive around 0.012-0.015 mGy/MBq. The adrenal glands, brain, kidneys, lungs, and spleen would receive slightly higher doses (0.02-0.03 mGy/MBq). The adrenal glands were identified as the organs receiving the greatest adsorbed radiation dose. The total exposure resulting from a 5 mCi administration of [ 18 F]FPS is well below the FDA defined limits for yearly cumulative and per study exposures to research participants. Extended acute toxicity studies in rats and rabbits, and limited acute toxicity studies in beagle dogs suggest at least a 175-fold safety margin in humans at a mass dose limit of 2.8 μg per intravenous injection. This estimate is based on the measured no observable effect doses (in mg/m 2 ) in these species. These data support the expectation that [ 18 F]FPS will be safe for use in human PET imaging studies at a maximum administration of 5 mCi and a mass dose equal to or less than 2.8 μg FPS per injection

  2. Preclinical acute toxicity studies and rodent-based dosimetry estimates of the novel sigma-1 receptor radiotracer [(18)F]FPS.

    Science.gov (United States)

    Waterhouse, Rikki N; Stabin, Michael G; Page, John G

    2003-07-01

    [(18)F]1-(Fluoropropyl)-4-[(4-cyanophenoxy)methyl]piperidine ([(18)F]FPS) is a novel high affinity (KD = 0.5 nM) sigma receptor radioligand that exhibits saturable and selective in vivo binding to sigma receptors in rats, mice and non-human primates. In order to support an IND application for the characterization of [(18)F]FPS through PET imaging studies in humans, single organ and whole body radiation adsorbed doses associated with [(18)F]FPS injection were estimated from distribution data obtained in rats. In addition, acute toxicity studies were conducted in rats and rabbits and limited toxicity analyses were performed in dogs. Radiation dosimetry estimates obtained using rat biodistribution analysis of [(18)F]FPS suggest that most organs would receive around 0.012-0.015 mGy/MBq. The adrenal glands, brain, kidneys, lungs, and spleen would receive slightly higher doses (0.02-0.03 mGy/MBq). The adrenal glands were identified as the organs receiving the greatest adsorbed radiation dose. The total exposure resulting from a 5 mCi administration of [(18)F]FPS is well below the FDA defined limits for yearly cumulative and per study exposures to research participants. Extended acute toxicity studies in rats and rabbits, and limited acute toxicity studies in beagle dogs suggest at least a 175-fold safety margin in humans at a mass dose limit of 2.8 microg per intravenous injection. This estimate is based on the measured no observable effect doses (in mg/m(2)) in these species. These data support the expectation that [(18)F]FPS will be safe for use in human PET imaging studies at a maximum administration of 5 mCi and a mass dose equal to or less than 2.8 microg FPS per injection.

  3. Preclinical acute toxicity studies and rodent-based dosimetry estimates of the novel sigma-1 receptor radiotracer [{sup 18}F]FPS

    Energy Technology Data Exchange (ETDEWEB)

    Waterhouse, Rikki N. E-mail: rn27@columbia.edu; Stabin, Michael G.; Page, John G

    2003-05-01

    [{sup 18}F]1-(Fluoropropyl)-4-[(4-cyanophenoxy)methyl]piperidine ([{sup 18}F]FPS) is a novel high affinity (KD = 0.5 nM) sigma receptor radioligand that exhibits saturable and selective in vivo binding to sigma receptors in rats, mice and non-human primates. In order to support an IND application for the characterization of [{sup 18}F]FPS through PET imaging studies in humans, single organ and whole body radiation adsorbed doses associated with [{sup 18}F]FPS injection were estimated from distribution data obtained in rats. In addition, acute toxicity studies were conducted in rats and rabbits and limited toxicity analyses were performed in dogs. Radiation dosimetry estimates obtained using rat biodistribution analysis of [{sup 18}F]FPS suggest that most organs would receive around 0.012-0.015 mGy/MBq. The adrenal glands, brain, kidneys, lungs, and spleen would receive slightly higher doses (0.02-0.03 mGy/MBq). The adrenal glands were identified as the organs receiving the greatest adsorbed radiation dose. The total exposure resulting from a 5 mCi administration of [{sup 18}F]FPS is well below the FDA defined limits for yearly cumulative and per study exposures to research participants. Extended acute toxicity studies in rats and rabbits, and limited acute toxicity studies in beagle dogs suggest at least a 175-fold safety margin in humans at a mass dose limit of 2.8 {mu}g per intravenous injection. This estimate is based on the measured no observable effect doses (in mg/m{sup 2}) in these species. These data support the expectation that [{sup 18}F]FPS will be safe for use in human PET imaging studies at a maximum administration of 5 mCi and a mass dose equal to or less than 2.8 {mu}g FPS per injection.

  4. Synthesis, characterization, and first successful monkey imaging studies of metabotropic glutamate receptor subtype 5 (mGluR5) PET radiotracers.

    Science.gov (United States)

    Hamill, Terence G; Krause, Stephen; Ryan, Christine; Bonnefous, Celine; Govek, Steve; Seiders, T Jon; Cosford, Nicholas D P; Roppe, Jeffrey; Kamenecka, Ted; Patel, Shil; Gibson, Raymond E; Sanabria, Sandra; Riffel, Kerry; Eng, Waisi; King, Christopher; Yang, Xiaoqing; Green, Mitchell D; O'Malley, Stacey S; Hargreaves, Richard; Burns, H Donald

    2005-06-15

    Three metabotropic glutamate receptor subtype 5 (mGluR5) PET tracers have been labeled with either carbon-11 or fluorine-18 and their in vitro and in vivo behavior in rhesus monkey has been characterized. Each of these tracers share the common features of high affinity for mGluR5 (0.08-0.23 nM vs. rat mGluR5) and moderate lipophilicity (log P 2.8-3.4). Compound 1b was synthesized using a Suzuki or Stille coupling reaction with [11C]MeI. Compounds 2b and 3b were synthesized by a SNAr reaction using a 3-chlorobenzonitrile precursor. Autoradiographic studies in rhesus monkey brain slices using 2b and 3b showed specific binding in cortex, caudate, putamen, amygdala, hippocampus, most thalamic nuclei, and lower binding in the cerebellum. PET imaging studies in monkey showed that all three tracers readily enter the brain and provide an mGluR5-specific signal in all gray matter regions, including the cerebellum. The specific signal observed in the cerebellum was confirmed by the autoradiographic studies and saturation binding experiments that showed tracer binding in the cerebellum of rhesus monkeys. In vitro metabolism studies using the unlabeled compounds showed that 1a, 2a, and 3a are metabolized slower by human liver microsomes than by monkey liver microsomes. In vivo metabolism studies showed 3b to be long-lived in rhesus plasma with only one other more polar metabolite observed. (c) 2005 Wiley-Liss, Inc.

  5. Radiotracer methods for effluent transport studies. A possibility of application for coastal sea waters and underground waters in near-sea region; Metody znacznikowe w badaniach transportu zanieczyszczen

    Energy Technology Data Exchange (ETDEWEB)

    Strzelecki, M.; Owczarczyk, A. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1994-12-31

    The surface and ground waters are a final receivers of industrial, agriculture and municipal effluents. The observation of their transport and deposition in environmental waters can be the expansion measure for ecological hazard estimation. The tracer methods are one of more convenient tools for studying the number of problems connecting with environmental waters protection. Among them the topics are described in the paper: transport of effluents in big water reservoirs and rivers as well as the effluent transport in aquifers. 9 refs.

  6. Biodistribution of gyroxin using 125I as radiotracer

    International Nuclear Information System (INIS)

    Alves da Silva, J.A.; Ribela, M.T.C.P.; Rogero, J.R.; Camillo, M.A.P.; Muramoto, E.

    2006-01-01

    The use of radiotracers in the research of animal venom has been scarce, although it allows an excellent approach to follow the process of bioavailability, biodistribution and kinetics of toxins. The purpose of this study was to assess gyroxin action mechanism, transport, compartments and action sites. This toxin is a thrombin-like and causes the barrel rotation syndrome. The gyroxin was labeled with 125 I and used as a tracer for the in vivo assay in mice. Blood samples and organs were collected at different time intervals, weighed and analyzed in a gamma-counter. The data was related with tissues distribution of protease activated receptor (PAR). Biodistribution assay allowed dividing the organs into three groups. The first one with the organs that followed the blood kinetics, the second with the organs related to metabolisms and elimination, and the third with the organs in which the gyroxin concentration increased during the observation period. (author)

  7. Studies of the radiolabeling and biodistribution of substance P using lutetium-177 as a radiotracer; Estudo da marcacao e biodistribuicao da substancia P utilizando lutecio-177 como radiotracador

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Clarice Maria de

    2011-07-01

    Malignant gliomas are primary brain tumors, resistant to various treatments, as chemotherapy, radiotherapy, induction of apoptosis and surgery. An alternative for the treatment of malignant gliomas is the radionuclide therapy. This technique apply radiolabeled molecules that selectively bind to tumor cells producing cytotoxic effect by dose irradiation, and resulting in death of tumor cells. Most protocols for radionuclide therapy of malignant brain tumors involve the administration of peptides labeled with {beta}{sup -} emitting radioisotopes. The Substance P (SP) is an 11- amino acid neuropeptide, characterized by the C-terminal sequence Phe-X-Gly-Leu-Met-NH{sub 2}. The use of SP labeled with different radionuclides including {sup 177}Lu, have been proposed for in vivo treatment of tumors. SP is the most important target of neurokinin 1 receptors, over expressed in malignant gliomas. The objective of this work was to study conditions of radiolabeling DOTA-SP with {sup 177}Lu, the stability of labeled compound and in vivo and in vitro, to develop a protocol production and evaluate the potential of the radiopharmaceutical in the therapy of gliomas. The labeling conditions were optimized varying the temperature, reaction time, activity of lutetium-177 chloride and mass of DOTA-SP. The radiochemical purity of preparations were analyzed by chromatographic techniques. The stability of {sup 17L}u -DOTA- SP radiolabeled with low activity of {sup 177}Lu was evaluated for different time at 2-8 degree C or incubated in human serum. The stability of the labeled with high activity of {sup 177}Lu was also analyzed in the presence of gentisic acid (6 mg / mL) added after the labeling reaction. The labeled conditions in low and high activity were subjected to evaluation for the ability to cause oxidation of methionine residue, adding the D-L- methionine amino acid to the reaction medium (6 mg / mL) and subsequent chromatographic evaluation. In vitro study with {sup 177}Lu

  8. Investigation of 3′-debenzoyl-3′-(3-([124I]-iodobenzoyl))paclitaxel analog as a radio-tracer to study multidrug resistance in vivo

    International Nuclear Information System (INIS)

    Sajjad, M.; Riaz, U.; Yao, R.; Bernacki, R.J.; Abouzied, M.; Erb, D.A.; Chaudhary, N.D.; Veith, J.M.; Georg, G.I.; Nabi, H.A.

    2012-01-01

    A study was carried out to identify a suitable radioactive paclitaxel analog and to use it to investigate tumor multidrug resistance in vivo. 3′-Debenzoyl-3′-(3-([ 124 I]-iodobenzoyl))paclitaxel was prepared by aromatic iodination of 3′-debenzoyl-3′-(3-trimethylstannylbenzoyl)paclitaxel. Uptake of the labeled paclitaxel analog in nude mice bearing tumor with the paclitaxel sensitive cancer cell lines MCF7 and MDA-435/LCC6(WT), and multidrug resistant cell lines NCI/ADR-RES and MDA-435/LCC6(MDR), was studied. There was no difference in drug level between the sensitive and resistant MDA-435/LCC6 tumors at 6 h post-injection. However, at 6 h, there was a significant increase in drug level for the MCF7 tumor as compared with the NCI/ADR-RES tumor, presumably due to increased drug retention. At 24 h, drug uptake/retention was significantly higher in both sensitive tumor cell lines as compared to their drug resistant counterparts. Pretreatment of mice with MDR transport modulators, Cyclosporine or tRA 96029, did not increase the level of labeled paclitaxel analog in the drug resistant MDA-435/LCC6(MDR) tumor. On the other hand, at 24 h Cyclosporine apparently increased analog level in the drug sensitive MDA-435/LCC6(WT) tumor, aiding drug imaging studies. - Highlights: ► 3′-Debenzoyl-3′-(3-iodobenzoyl)paclitaxel cytotoxicity was comparable to paclitaxel. ► 3′-Debenzoyl-3′-(3-([ 124 I]-iodobenzoyl)paclitaxel was synthesized. ► Uptake of the drug was higher in sensitive tumor compared to the resistant tumor. ► The Pgp-modulators had a positive effect on drug-sensitive tumor. ► The sensitive tumor was visible in images obtained using micoPET.

  9. Drug uptake (DAPI) of trypanosomes (T. brucei) and antitrypanosomal activity in vitro, in culture and in vivo studied by microscope fluorometry, chromatogram spectrophotometry and radiotracer techniques

    International Nuclear Information System (INIS)

    Kratzer, R.D.

    1982-01-01

    The present study had the following objectives: 1) Investigation of the specific binding and location of the diamidine DAPI within trypanosomes by fluorescence microscopy. 2) Development and standardization of a microscope fluorometry technique for measuring DAPI uptake of single trypanosomes. 3) Determination of the effect of incubation media, exposure time, and drug concentration on DAPI uptake of single trypanosomes. 4) Development of a technique applicable for quantitative fluorescence chemical analysis of DAPI uptake of trypanosomes. 5) Determination of drug uptake of trypanosomes using 14 C labelled DAPI. 6) Comparison of the values obtained by the three methods. (orig./MG)

  10. Radiotracer study of the adsorption of Fe(III), Cr(III) and Cd(II) on natural and chemically modified Slovak zeolite

    International Nuclear Information System (INIS)

    Foeldesova, M.; Dillinger, P.; Lukac, P.

    1998-01-01

    In order to minimize the contamination of environment with metals in ionic form the more types of natural and chemically modified zeolites were examined to their uptake of Fe(III), Cr(III) and Cd(II) from water solutions by batch radio-exchange equilibration method. In this study was used zeolitic tuff from deposit Nizny Hrabovec (content of clinoptilolite 50-70%) with the grain size from 1.2 to 2.2 mm. The granules of zeolite were modified with the following NaOH solutions: ).5, 1, 2 and 4 mol.l -1 at 80 grad C for 4 hours. The sorption of Fe, Cr and Cd ions on all types of zeolites was studied by radio-exchange method and the sorption of Fe and Cr also flame atomic absorption method. From sorption curves the sorption coefficients were calculated. The results obtained in this work show that zeolites modified with NaOH solution are suitable for adsorption of Fe(III), Cr(III) and Cd(II) from underwater, waste water, feed water and coolant water from nuclear plants. The adsorbed zeolites can be solidified by conventional way

  11. Leakage investigation in an underground cooling water pipeline at a thermal power station using radiotracer technique

    International Nuclear Information System (INIS)

    Khan, I.H.; Din, U.G.; Gul, S.; Farooq, M.; Qureshi, R.M.

    2004-05-01

    The objective of this study was to locate the leakage point(s) in an underground cooling water pipeline of a Thermal Power Station for pre-shutdown planning purposes. The internal diameter of the pipeline was 2240 mm with 12 mm with 12 (mild steel) wall thickness and it was buried under 1.0 meter reinforced concrete and 0.5-1.0 meter soil/sand cover. The volume flow rate of the pipeline was 29043 m/sup 3/hour at 2kg/cm/sup 2/ pressure. The linear speed of water flowing inside the pipeline was around 2 m/sec. This gave rise to a very high volume fast moving system. Radiotracer technique was used to investigate the problem under investigation. About 50 mCi of /sup 131/I radiotracer, in the form of NaI solution, was injected into the system and radiotracer evolution near suspected leakage point(s) was monitored using radiation detectors (NaI, 2 x 2 inch crystal size). Seven detectors were installed around three teeing off pipes (leakage area) inside the plant building and one at the injection point near the pump outlet. On line data acquisition system was used to acquire the radiotracer data. The leakage water was exiting from the floor just along the pipes carrying main flow of water. The time lag between the arrival, at detectors, of radiotracer flowing inside the pipeline and that present in the leakage water (outside the pipeline) was exploited to identify the position of leakage. The tracer test revealed that there was leakage at two points. The leakage at one point was small as compared at the other points. (author)

  12. A method based on Monte Carlo simulations and voxelized anatomical atlases to evaluate and correct uncertainties on radiotracer accumulation quantitation in beta microprobe studies in the rat brain

    Science.gov (United States)

    Pain, F.; Dhenain, M.; Gurden, H.; Routier, A. L.; Lefebvre, F.; Mastrippolito, R.; Lanièce, P.

    2008-10-01

    The β-microprobe is a simple and versatile technique complementary to small animal positron emission tomography (PET). It relies on local measurements of the concentration of positron-labeled molecules. So far, it has been successfully used in anesthetized rats for pharmacokinetics experiments and for the study of brain energetic metabolism. However, the ability of the technique to provide accurate quantitative measurements using 18F, 11C and 15O tracers is likely to suffer from the contribution of 511 keV gamma rays background to the signal and from the contribution of positrons from brain loci surrounding the locus of interest. The aim of the present paper is to provide a method of evaluating several parameters, which are supposed to affect the quantification of recordings performed in vivo with this methodology. We have developed realistic voxelized phantoms of the rat whole body and brain, and used them as input geometries for Monte Carlo simulations of previous β-microprobe reports. In the context of realistic experiments (binding of 11C-Raclopride to D2 dopaminergic receptors in the striatum; local glucose metabolic rate measurement with 18F-FDG and H2O15 blood flow measurements in the somatosensory cortex), we have calculated the detection efficiencies and corresponding contribution of 511 keV gammas from peripheral organs accumulation. We confirmed that the 511 keV gammas background does not impair quantification. To evaluate the contribution of positrons from adjacent structures, we have developed β-Assistant, a program based on a rat brain voxelized atlas and matrices of local detection efficiencies calculated by Monte Carlo simulations for several probe geometries. This program was used to calculate the 'apparent sensitivity' of the probe for each brain structure included in the detection volume. For a given localization of a probe within the brain, this allows us to quantify the different sources of beta signal. Finally, since stereotaxic accuracy is

  13. Blood circulation of the inner ear under the influence of medications. Radiotracer experiments using guinea pig cochlea

    International Nuclear Information System (INIS)

    Neumeier, A.

    1987-01-01

    The dependence of the blood circulation in the inner ear on various medications is discussed. By means of a radiotracer clearance technique the cochlear clearance curves for the guinea pig cochlea after the administration of various circulation stimulants were determined. (MBC) [de

  14. Study on physical and electrostatic interactions of counterions in poly(perfluorosulfonic) acid matrix: Characterization of diffusion properties of membrane using radiotracers

    International Nuclear Information System (INIS)

    Suresh, G.; Sodaye, Suparna; Scindia, Y.M.; Pandey, A.K.; Goswami, A.

    2007-01-01

    The self-diffusion coefficients of water and ions were used to study the physical (tortuosity) and electrostatic interactions of counterions in poly(perfluorosulfonic) acid membrane (Nafion-117) matrix. The self-diffusion coefficients of water (D H 2 O m ) were measured in the water swollen Nafion-117 membrane with Zn 2+ , Ca 2+ , Sr 2+ , and Fe 2+ counterions by analyzing the experimental exchange rates between tritium tagged water (HTO) in membrane and equilibrating water. In order to study the effects of equilibrating solution, the HTO-desorption rate profiles between the membrane samples in H + or Cs + forms and equilibrating solution containing CsCl or HCl (0.25mol/L) were measured. It was observed that the HTO-exchange rate profile was slower in case of membrane sample in Cs + -from equilibrated with salt/acid solution than that equilibrated with deionized water in same ionic form. However, HTO-exchange rate profile did not alter in case of H + -form of membrane on equilibration with salt or acid solution. The variation of lnD H 2 O m with polymer volume function V p /(1-V p ), where V p is polymer volume fraction, indicated that: (i) D H 2 O m in the membrane with multivalent counterions was lower than that reported for membrane with monovalent counterions at same V p , and (ii) the linear trends observed in variation of lnD H 2 O m with V p /(1-V p ) for multivalent and monovalent counterions were significantly different. The values of D H 2 O m in membrane normalized with D H 2 O m at V p =0 were taken as an estimate of the tortuosity factor for self-diffusion of ions in the membrane matrix. The self-diffusion coefficients of ions reported in the literature along with tortuosity factor obtained from D H 2 O m in the corresponding ionic forms of the membrane were analyzed to obtain the charge (Z i ) independent electrostatic interaction parameter g(φ) of monovalent and divalent ions in the membrane. This analysis indicated that g(φ) also vary

  15. Double radio-tracer tagging of mud in the Gironde: an experimental study of the behaviour of a metallic pollutant in an estuary

    International Nuclear Information System (INIS)

    Etcheber, H.; Jouanneau, J.M.; Latouche, C.; Azoeuf, P.; Caillot, A.; Hoslin, R.

    1980-01-01

    In order to understand the behaviour of metals accidentally introduced into an estuarine system, an experiment using radioactive tracers was conducted in the Gironde estuary. Based on the preliminary laboratory studies on the reactivity of radioisotopes 65 Zn and 175+181 Hf with different physicochemical agents, they were proved to be suitable for the experiment designed. A quantity of sediment contaminated by these two isotopes was introduced in the upstream part of the Gironde. During transport downstream, it was observed that the Zn/Hf couple on the sediment decreased from an initial ratio of 0.7 to 0.07-0.05 in the fluid mud lenses and in the bottom sediment of the lower estuary at the end of the experiment (3 months). It was lower than 0.2 in the suspended sediments. This is considered to indicate that a part of the zinc is dissociated from the hafnium and released from its particulate support; this signifies a solubilization of the zinc. These experimental data give a new insight into the problem concerning the decrease of stable zinc associated with suspended sediment at the fresh water/salt water interface [fr

  16. Radiotracers in medical applications, vols 1-2

    International Nuclear Information System (INIS)

    Rayudu, G.V.S.

    1983-01-01

    These volumes will serve as a basis for instruction and reference for professionals such as radiopharmaceutical chemists, radiopharmacologists, radiopharmacists, radiobiochemists, and others involved in the medical applications of radiotracers. Vol. I: Topics include radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; 11 C, 13 N, 15 O, 67 Ga. 111 In, 75 Se, /SUP 123m/ Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented

  17. Radiological protection in the use of radiotracers in industrial process

    International Nuclear Information System (INIS)

    Costa, M.L L.; Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C.; Thomé, Z.D.

    2017-01-01

    The use of radiotracers plays an important role to provide methods to optimize industrial process and improve product quality. An increase in the use of radiotracers investigations has been observed in Brazil, however, as there is no specific standard for the licensing of these facilities, generic radiation protection regulations have been used, but these are not comprehensive or technically suitable for this purpose. Regulatory inspections in radiotracer facilities have reported failures in disagreement with best practices for radiological safety, mainly in radioactive waste management and in the control of workplaces during radiotracer injections. In this work, an assessment of radiological protection aspects of radioactive tracers is performed, based on the licensing process of radiotracers facilities, as well as the experience of regulatory inspections and a review of international standards, pointing out relevant radiation safety aspects for working practices, procedures and protective measures before, during and after injections of radioactive tracers, in order to contribute to the future development of specific safety regulations on radiotracers in Brazil. (author)

  18. Radiological protection in the use of radiotracers in industrial process

    Energy Technology Data Exchange (ETDEWEB)

    Costa, M.L L.; Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C., E-mail: mara@cnen.gov.br, E-mail: rogeriog@cnen.gov.br, E-mail: jlopes@cnen.gov.br, E-mail: evaldo@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Diretoria de Radioproteção e Segurança Nuclear; Thomé, Z.D., E-mail: zielithome@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Seção de Engenharia Nuclear

    2017-07-01

    The use of radiotracers plays an important role to provide methods to optimize industrial process and improve product quality. An increase in the use of radiotracers investigations has been observed in Brazil, however, as there is no specific standard for the licensing of these facilities, generic radiation protection regulations have been used, but these are not comprehensive or technically suitable for this purpose. Regulatory inspections in radiotracer facilities have reported failures in disagreement with best practices for radiological safety, mainly in radioactive waste management and in the control of workplaces during radiotracer injections. In this work, an assessment of radiological protection aspects of radioactive tracers is performed, based on the licensing process of radiotracers facilities, as well as the experience of regulatory inspections and a review of international standards, pointing out relevant radiation safety aspects for working practices, procedures and protective measures before, during and after injections of radioactive tracers, in order to contribute to the future development of specific safety regulations on radiotracers in Brazil. (author)

  19. Assessing of bulk materials mixing and sorting by radiotracer methods

    International Nuclear Information System (INIS)

    Thyn, J.

    1983-01-01

    Various applications are indicated of tracer techniques for the evaluation of mixing and sorting of mixtures of solid particles. The evaluation of the process of mixing, i.e., the determination of the homogenization time is done by labelling of the entire volume of the monitored component of the mixture and continuous detection of radiation through the walls of the mixer using one or several detectors. The evaluation of the character of the flow and the evacuation of solid particles from the bin is done by labelling with a radiotracer the material which is spread out on the top along the whole cross-section of the bin, and the concentration is monitored of the tracer in the material outflow. The evaluation of material sorting in bins which takes place during the filling and emptying is done on the basis of significance tests or using self-correlation functions and frequency characteristics. Also monitored was the dependence of the equalizing ability of the continuous gravity mixer at the vertex angle of the tip. (M.D.)

  20. Radiotracer investigation in gold leaching tanks

    Energy Technology Data Exchange (ETDEWEB)

    Dagadu, C.P.K., E-mail: dagadukofi@yahoo.co.uk [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Akaho, E.H.K.; Danso, K.A. [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Stegowski, Z.; Furman, L. [Faculty of Physics and Applied Computer Science, AGH-UST, 30-059 Krakow (Poland)

    2012-01-15

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: Black-Right-Pointing-Pointer I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. Black-Right-Pointing-Pointer Online data collection is more convenient method for tracer monitoring in industrial process systems. Black-Right-Pointing-Pointer The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. Black-Right-Pointing-Pointer The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  1. Radiotracer investigation in gold leaching tanks

    International Nuclear Information System (INIS)

    Dagadu, C.P.K.; Akaho, E.H.K.; Danso, K.A.; Stegowski, Z.; Furman, L.

    2012-01-01

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: ► I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. ► Online data collection is more convenient method for tracer monitoring in industrial process systems. ► The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. ► The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  2. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    International Nuclear Information System (INIS)

    Sugiharto, S.; Kurniadi, R.; Abidin, Z.; Stegowski, Z.; Furman, L.

    2013-01-01

    Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT) having an inner diameter of 24 in (60,96 m). The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD) curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD) simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct. (author)

  3. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    S. Sugiharto1

    2013-04-01

    Full Text Available Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT having an inner diameter of 24 in (60,96 m. The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct

  4. New-generation radiotracers for nAChR and NET

    Energy Technology Data Exchange (ETDEWEB)

    Ding Yushin [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)]. E-mail: ding@bnl.gov; Fowler, Joanna [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2005-10-01

    Advances in radiotracer chemistry and instrumentation have merged to make positron emission tomography (PET) a powerful tool in the biomedical sciences. Positron emission tomography has found increased application in the study of drugs affecting the brain and whole body, including the measurement of drug pharmacokinetics (using a positron-emitter-labeled drug) and drug pharmacodynamics (using a labeled tracer). Thus, radiotracers are major scientific tools enabling investigations of molecular phenomena, which are at the heart of understanding human disease and developing effective treatments; however, there is evidently a bottleneck in translating basic research to clinical practice. In the meantime, the poor ability to predict the in vivo behavior of chemical compounds based on their log P's and affinities emphasizes the need for more knowledge in this area. In this article, we focus on the development and translation of radiotracers for PET studies of the nicotinic acetylcholine receptor (nAChR) and the norepinephrine transporter (NET), two molecular systems that urgently need such an important tool to better understand their functional significance in the living human brain.

  5. Uptake of heavy metals by the marine algae Padina gymnospora from Sepetiba Bay (RJ, Brazil) through radiotracers

    International Nuclear Information System (INIS)

    Magalhaes, V.F. de.

    1991-01-01

    The accumulation and the loss of 210 Pb, 51 Cr and 65 Zn by the alga Padina gymnospora is studied through radiotracer experiments. The evaluation of the alga as a bio indicator of these heavy metals pollution is presented. The use of this seaweed species to study the transfer of Pb, Cr, and Zn through the food chain is discussed. (M.A.C.)

  6. CFD simulation of homogenisation time measured by radiotracers

    International Nuclear Information System (INIS)

    Thyn, J.; Novy, M.; Zitny, R.; Mostik, M.; Jahoda, M.

    2004-01-01

    A methodology for CFD (Computational Fluid Dynamics) simulation of radiotracer experiments was suggested. The most important parts of the methodology for validation of CFD results by radiotracers are: a) successful simulation of tracer experiment by CFD code (numerical solution of tracer dispersion in a stirred tank), which results in tracer concentration field at several time intervals; b) post-process data treatment, which uses detection chain description and which enables to simulate the detector measurement of homogenisation time from the tracer concentration field evaluated by CFD code. (author)

  7. Radiotracer technique for leakage detection under simulated conditions

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Sharma, V.K.; Tapase, A.S.

    2001-01-01

    Radiotracer techniques are often used to locate leaks in underground pipelines. An attempt was made to standardize radiotracer pulse migration in terms of minimum detectable limit. For this purpose a 6 inch diameter 1200 long steel pipe was used. Two leak rates viz. 10 litres per minute and 1 litre per minute with an accuracy of ± 10% were simulated. The experiments on this pipeline showed that this method could be used to locate a leak of the order of 1 litre per minute in a 6 inch diameter isolated underground pipeline. (author)

  8. Radiotracer technology as applied to industry. Final report of a co-ordinated research project 1997-2000

    International Nuclear Information System (INIS)

    2001-12-01

    The Co-ordinated Research Project (CRP) on Radiotracer Technology for Engineering Unit Operation Studies and Unit Process Optimization was carried out by the International Atomic Energy Agency (IAEA) from December 1997 until December 2000. The project developed and validated procedures and protocols for investigation of major industrial processes, including fluidized beds, sugar crystallizers, trickle bed reactors, cement rotary kilns, flotation cells, grinding mills, incinerators, wastewater treatment units and interwell communications in oil fields. This publication is the output of the above mentioned CRP. It provides the principles and state of the art of radiotracer methodology and technology as applied to industry and environment. It is expected to provide wider interest for further development of skills and confidence prior to carrying out field work. It facilitates transfer of technology from developed to developing countries and from nuclear research institutions to industrial end users. The publication could be a suitable guide for radiotracer applications in almost all types of process investigations. The case studies described in this publication deal with typical problems in industry and environment common to all countries. It is intended for radiotracer groups as well as for end engineers and managers from chemical and petrochemical industries, mineral ore and raw material processing, wastewater treatment plants, and other industrial sectors

  9. Research and development in radiotracer methodology and technology

    Energy Technology Data Exchange (ETDEWEB)

    Thereska, J. [International Atomic Energy Agency (IAEA), Vienna (Austria)

    2001-07-01

    An IAEA Coordinated Research Project (CRP) has promoted further the radiotracer technology, in particular has validated the residence time distribution (RTD) function in investigating many chemical engineering reactors, such as grinding mill and flotation cell, incinerator, crystallizer trickle bed reactor and waste water treatment units. (authors)

  10. Research and development in radiotracer methodology and technology

    International Nuclear Information System (INIS)

    Thereska, J.

    2001-01-01

    An IAEA Coordinated Research Project (CRP) has promoted further the radiotracer technology, in particular has validated the residence time distribution (RTD) function in investigating many chemical engineering reactors, such as grinding mill and flotation cell, incinerator, crystallizer trickle bed reactor and waste water treatment units. (authors)

  11. Biosorptive behaviour of Mango (Mangifera indica) and Neem (Azadirachta indica) bark for Hg{sup 2+}, Cr{sup 3+} and Cd{sup 2+} toxic ions from aqueous solutions: a radiotracer study

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Diwakar; Mishra, Shuddhodan P. [Nuclear and Radiochemistry Laboratory, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi (India); Mishra, Manisha; Dubey, R.S. [Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi (India)

    1999-04-01

    Biosorption of Hg{sup 2+} and Cr{sup 3+} on dead biomass Mango (Mangifera indica) and Neem (Azadirachta indica) bark has been assessed at micro to tracer level concentrations from aqueous solutions employing the 'radiotracer technique'. A high level of uptake of metal ions on these solid surfaces occurs within ca. 4 h of contact time reaching apparent saturation. The increase of sorptive concentration (10{sup -8} to 10{sup -2} mol dm{sup -3}), temperature (293-323 K) and pH (ca. 3 to 10) favoured the removal process of these ions; but in the case of Hg{sup 2+} on Neem bark, there was seemingly no temperature effect. The uptake process follows first order rate law and obeys the Freundlich adsorption isotherm. Added anions and cations in the bulk solution inhibit to some extent the removal of these toxic ions. Similarly the inhibition in the uptake was also observed when both biomasses were irradiated by neutron and {gamma}-rays prior to being employed as sorbents. No significant sorption of Cd{sup 2+} was observed on these dead biomass solid surfaces under various physical-chemical conditions.

  12. Radiotracers For Lipid Signaling Pathways In Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S. J. [Northeastern Univ., Boston, MA (United States)

    2016-09-26

    The primary focus of this project continues to be the development of radiotracers and radiotracer methodology for studying physiology and biochemistry. The compounds that have been labeled areacylethanolamines and acylglycerols that are, as classes, represented in both in plants and in animals. In the latter, some of these act as ligands for cannabinoid receptors and they are therefore known as endocannabinoids. Cannabinoid receptors are not found in plant genomes so that plants must contain other receptors and signaling systems that use acylethanolamines. Relatively little work has been done on that issue, though acylethanolamines do modulate plant growth and stress resistance, thus possessing obvious relevance to agriculture and energy production. Progress has been described in five peer-reviewed papers and seven meeting abstracts. Preparation of 2-acylglycerol lipid messengers in high purity. A novel enzymatic synthesis was developedthat gave pure 2-acylglycerols free of any rearrrangement to the thermodynamically more stable 1(3)-acylglycerol byproducts. The method utilized 1,3-dibutyryl-2-acylglycerol substrate ethanolysis by a resinimobilized lipase. Thus, pure radiolabeled 2-acylglycerols can now be conveniently prepared just prior to their utilization. These synthetic studies were published in the Journal of Medicinal Chemistry, 2011. Diacylglycerol lipase assay methodology. Diacylglycerol lipases (DAGLs) generate 2- acylglycerols, and are thus potential targets for disease- or growth-modifying agents, by means of reducing formation of 2-acylglycerols. A radioTLC assay of the hydrolysis of radiolabeled diglyceride substrate [1''-carbon-14]2-arachidonoyl-1-stearoyl-sn-glycerol has been implemented, and used to validate a novel, potentially highthroughput fluorescence resonance energy transfer (FRET) based assay. A number of new DAGL inhibitors that have selectivity for DAGLs were synthesized and screened. This work was very recently published in

  13. Dose-on-demand production of diverse 18F-radiotracers for preclinical applications using a continuous flow microfluidic system.

    Science.gov (United States)

    Matesic, Lidia; Kallinen, Annukka; Greguric, Ivan; Pascali, Giancarlo

    2017-09-01

    The production of 18 F-radiotracers using continuous flow microfluidics is under-utilized due to perceived equipment limitations. We describe the dose-on-demand principle, whereby the back-to-back production of multiple, diverse 18 F-radiotracers can be prepared on the same day, on the same microfluidic system using the same batch of [ 18 F]fluoride, the same microreactor, the same HPLC column and SPE cartridge to obtain a useful production yield. [ 18 F]MEL050, [ 18 F]Fallypride and [ 18 F]PBR111 were radiolabeled with [ 18 F]fluoride using the Advion NanoTek Microfluidic Synthesis System. The outlet of the microreactor was connected to an automated HPLC injector and following the collection of the product, SPE reformulation produced the 18 F-radiotracer in productions for [ 18 F]MEL050 and [ 18 F]Fallypride were performed at total flow rates of 20μL/min, resulting in 40±13% and 25±13% RCY respectively. [ 18 F]PBR111 was performed at 200μL/min to obtain 27±8% RCY. Molar activities for each 18 F-radiotracer were >100GBq/μmol and radiochemical purities were >97%, implying that the cleaning procedure was effective. Using the same initial solution of [ 18 F]fluoride, microreactor, HPLC column and SPE cartridge, three diverse 18 F-radiotracers could be produced in yields sufficient for preclinical studies in a back-to-back fashion using a microfluidic system with no detectable cross-contamination. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  14. Comparison of In Vitro Assays in Selecting Radiotracers for In Vivo P-Glycoprotein PET Imaging

    Directory of Open Access Journals (Sweden)

    Renske M. Raaphorst

    2017-09-01

    Full Text Available Positron emission tomography (PET imaging of P-glycoprotein (P-gp in the blood-brain barrier can be important in neurological diseases where P-gp is affected, such as Alzheimer´s disease. Radiotracers used in the imaging studies are present at very small, nanomolar, concentration, whereas in vitro assays where these tracers are characterized, are usually performed at micromolar concentration, causing often discrepant in vivo and in vitro data. We had in vivo rodent PET data of [11C]verapamil, (R-N-[18F]fluoroethylverapamil, (R-O-[18F]fluoroethyl-norverapamil, [18F]MC225 and [18F]MC224 and we included also two new molecules [18F]MC198 and [18F]KE64 in this study. To improve the predictive value of in vitro assays, we labeled all the tracers with tritium and performed bidirectional substrate transport assay in MDCKII-MDR1 cells at three different concentrations (0.01, 1 and 50 µM and also inhibition assay with P-gp inhibitors. As a comparison, we used non-radioactive molecules in transport assay in Caco-2 cells at a concentration of 10 µM and in calcein-AM inhibition assay in MDCKII-MDR1 cells. All the P-gp substrates were transported dose-dependently. At the highest concentration (50 µM, P-gp was saturated in a similar way as after treatment with P-gp inhibitors. Best in vivo correlation was obtained with the bidirectional transport assay at a concentration of 0.01 µM. One micromolar concentration in a transport assay or calcein-AM assay alone is not sufficient for correct in vivo prediction of substrate P-gp PET ligands.

  15. A dynamic approach to dependability studies

    International Nuclear Information System (INIS)

    Labeau, P.E.

    2008-01-01

    Dependability studies have now become an important part of the performance management of industrial plants. These last decades, several methods have been proposed and widely used for the analysis of systems of components subject to degradation and failure. These methods are based either on Boolean representations (for example, event trees/fault trees), or on discrete-state models (Markovian reliability, Petri nets, Bayesian networks...). However, the underlying, inherently continuous, physical processes have scarcely been accounted for, at least in an integrated fashion, in dependability studies. This paper first describes, through simple cases, the limitations of discrete approaches and the need of hybrid, discrete-continuous methods. It then summarizes the main concepts of dynamic reliability. Finally, some possible application domains are presented, as well as challenges that still need to be tackled to favour the diffusion of this approach among industrial circles. (author)

  16. Radiotracer and sealed source techniques for sediment management. Report of the consultants meeting

    International Nuclear Information System (INIS)

    2008-01-01

    Radioisotopes as tracers and sealed sources have been a useful and often irreplaceable tool for sediment transport studies. Gamma scattering and transmission gauges are used for sediment monitoring. Computational fluid dynamics (CFD) modelling is now an essential tool for the management of the natural systems and are increasingly used to study the fate and behaviour of particulates and contaminants. Radiotracer techniques are often employed to validate CFD models to enhance confidence in the predictive value of the models. Experimental tracing and numerical modelling are complementary methods of studying complex systems. During the last few decades, many radiotracer studies for the investigation of sediment transport in natural systems have been conducted worldwide, and various techniques for tracing and monitoring sediment have been developed by individual tracer groups. However, the developed techniques and methods for sediment tracing have not been compiled yet as a technical document, which is essential for the preservation of the knowledge and transfer of the technology to developing countries. Standard procedures or guidelines for the tracer experiments, which are vital for the reliability of the experiments and the acceptance of end-users, have not been established by the international tracer community either. The use of radiotracers in sediment transport studies demands the additional attention of the community to further develop these techniques and to ensure their transfer to developing countries. The Consultants' Meeting on 'Radiotracer and sealed source techniques for sediment management' was convened at the headquarters of the International Atomic Energy Agency (IAEA) in Vienna, Austria, from 21 to 25 April 2008. Experts from Argentina, Brazil, France, India, Republic of Korea and United Kingdom have been invited to discuss the current status of the tracer and nucleonic gauge technologies as applied for sediment transport investigations and to evaluate

  17. Radiotracer and sealed source techniques for sediment management. Report of the consultants meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Radioisotopes as tracers and sealed sources have been a useful and often irreplaceable tool for sediment transport studies. Gamma scattering and transmission gauges are used for sediment monitoring. Computational fluid dynamics (CFD) modelling is now an essential tool for the management of the natural systems and are increasingly used to study the fate and behaviour of particulates and contaminants. Radiotracer techniques are often employed to validate CFD models to enhance confidence in the predictive value of the models. Experimental tracing and numerical modelling are complementary methods of studying complex systems. During the last few decades, many radiotracer studies for the investigation of sediment transport in natural systems have been conducted worldwide, and various techniques for tracing and monitoring sediment have been developed by individual tracer groups. However, the developed techniques and methods for sediment tracing have not been compiled yet as a technical document, which is essential for the preservation of the knowledge and transfer of the technology to developing countries. Standard procedures or guidelines for the tracer experiments, which are vital for the reliability of the experiments and the acceptance of end-users, have not been established by the international tracer community either. The use of radiotracers in sediment transport studies demands the additional attention of the community to further develop these techniques and to ensure their transfer to developing countries. The Consultants' Meeting on 'Radiotracer and sealed source techniques for sediment management' was convened at the headquarters of the International Atomic Energy Agency (IAEA) in Vienna, Austria, from 21 to 25 April 2008. Experts from Argentina, Brazil, France, India, Republic of Korea and United Kingdom have been invited to discuss the current status of the tracer and nucleonic gauge technologies as applied for sediment transport investigations and to evaluate

  18. Dynamic PET scanning and compartmental model analysis to determine cellular level radiotracer distribution in vivo

    International Nuclear Information System (INIS)

    Smith, G.T.; Hubner, K.F.; Goodman, M.M.; Stubbs, J.B.

    1992-01-01

    Positron emission tomography (PET) has been used to measure tissue radiotracer concentration in vivo. Radiochemical distribution can be determined with compartmental model analysis. A two compartment model describes the kinetics of N-13 ammonia ( 13 NH 3 ) in the myocardium. The model consists of a vascular space, Q 1 and a space for 13 NH 3 bound within the tissue, Q 2 . Differential equations for the model can be written: X(t) = AX(t) + BU( t), Y(t)= CX(t)+ DU(t) (1) where X(t) is a column vector [Q 1 (t); Q 2 (t)], U(t) is the arterial input activity measured from the left ventricular blood pool, and Y(t) is the measured tissue activity using PET. Matrices A, B, C, and D are dependent on physiological parameters describing the kinetics of 13 NH 3 in the myocardium. Estimated parameter matrices in Equation 1 have been validated in dog experiments by measuring myocardial perfusion with dynamic PET scanning and intravenous injection of 13 NH 3 . Tracer concentrations for each compartment can be calculated by direct integration of Equation 1. If the cellular level distribution of each compartment is known, the concentration of tracer within the intracellular and extracellular space can be determined. Applications of this type of modeling include parameter estimation for measurement of physiological processes, organ level dosimetry, and determination of cellular radiotracer distribution

  19. Radiotracer experiments and CFD simulation for industrial hydrocyclone performance

    International Nuclear Information System (INIS)

    Stegowski, Z.; Nowak, E.

    2007-01-01

    Hydrocyclone is a device for solid concentration or selection of solid particles from a liquid-solid mixture. It is widely used in the mineral industry for selection of solid particles from a few to a few hundred micrometers. This paper presents a radiotracer experiment and computational simulation of selection of solid particles in a hydrocyclone of Φ-500 μm, which is used in the industrial copper ore concentration process. The simulation, based on computational fluid dynamics (CFD) techniques, allowed obtaining the velocity and concentration distribution for a real mixture flowing in the hydrocyclone. The mixture was composed of water and nine solid phases of different grain sizes. Finally, the selection curve of solid grains was obtained and compared with the experimental radiotracer results. (author)

  20. Hydrodynamic characteristics of high speed settling clarifiers by radiotracer method

    International Nuclear Information System (INIS)

    Griffith Martinez, J.; Flores Juan, P.; Cuesta Borges, J.; Damera Martinez, A.; Ramos Espinosa, K. A

    2005-01-01

    Results achieved in the evaluation of two high-speed settling cane juice Clarifiers, one denominated ICINAZ The Express and the other one with Low Residence Time (BTR), both located at the sugar factory Orlando Gonzalez employing the well established radiotracer method (Tc-99m) are presented. Several trials performed at the two Clarifiers demonstrated that the one identified as BTR was capable to assimilate the whole flow capacity of the factory with adequate characteristic of the pattern flux and residence time in the environment of 1 hour. In the other side, ICINAZ The Express Clarifier could only work at relative low flow capacity of the factory with residence time closely to the two hours and achieving occasionally a pattern flux seriously affected by fluctuations in the milling process. The radiotracer method was able to detect certain differences between the two clear juice outlet of the BTR Clarifier, probably due some problems in the construction of this equipment

  1. Application of analogue computers to radiotracer data processing

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    1979-01-01

    Some applications of analogue computers for processing the flow-system radiotracer-investigation data are presented. Analysis of the impulse response shaped to obtain the frequency response of the system under consideration can be performed on the basis of an estimated transfer function. Furthermore, simulation of the system behaviour for other excitation functions is discussed. Simple approach is made for estimating the model parameters in situations where the input signal is not approximated by the unit impulse function. (author)

  2. Radiotracer technique to predict irritation potential of soap

    International Nuclear Information System (INIS)

    Castaneda, S.S.; Garcia, T.Y.; Santos, F.L.

    1990-01-01

    The application of a radiotracer technique using tritiated water to predict the irritation potentials of some soap products is demonstrated. Collagen films are treated with 0.5% and 1.0% soap solutions and tritiated water then incubated at 50 degrees centigrade for 24 hours. After incubation, the uptake of tritiated water by the collagen films was measured by liquid scintillation counting. (Auth.). 6 refs., 2 tabs

  3. [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine receptors using single photon emission computer tomography; [{sup 123}I]-3-Iodcytisin als moeglicher Radiotracer fuer die Darstellung der nikotinergen Acetylcholin Rezeptoren mittels Single-Photon-Emissions-Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, Dagmar Julia

    2015-03-06

    For the synthesis of [{sup 123}I]-3-Iodcytisin as possible radiotracer for the imaging of nicotinic acetylcholine (nACh) receptors using SPECT two different technologies were used: the radio-iodination with iodogen and the radio-iodination with nitric acid. The latter one showed higher efficiency. The radiotracer will allow to detect degenerative processes and other nACh-depending diseases in the brain (Alzheimer, Parkinson) and to observe the progress. The autoradiography is aimed to the imaging of the nACh receptors in the brain bypassing the brain-blood barrier. The highest activity was measured in the thalamus of mice and rat brains.

  4. Iodine-123-labeled radiotracers for cardiovascular and testicular imaging studies: labeling of phenyl fatty acids for myocardial studies, fibronectin for thrombus localization, and human chorionic gonadotropin for testicular studies

    International Nuclear Information System (INIS)

    Kulkarni, P.V.; Lewis, S.E.; McConnell, J.; Buja, L.M.; Wilson, J.E. III; Willerson, J.T.; Parkey, R.W.

    1985-01-01

    Development and evaluation of iodine-123-labeled compounds for potential applications in certain imaging studies are described. A new method utilizing an organothallium intermediate has been developed to radioiodinate phenyl fatty acids. The method is simple, and consistently high yields (80 to 90%) can be obtained on a routine basis. The biodistribution patterns of the product prepared by this method were found to be very similar to those produced by the direct electrophilic substitution method. Radioiodinated fibronectin (FN) localized in experimental thrombi and pulmonary emboli. In dogs the deep-vein thrombi could be visualized within 3 hr of postinjection of the tracer. Radioiodinated human chorionic gonadotropin (HCG) localized in rat testes which permitted the scintigraphic visualization of scrotal as well as abdominal testes in rats. The localization appears to be receptor mediated

  5. Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis

    International Nuclear Information System (INIS)

    Wiebe, L.I.

    1984-01-01

    Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use. (author)

  6. Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis

    Science.gov (United States)

    Wiebe, Leonard I.

    Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and (approved) medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use.

  7. Intra-operative nuclear imaging based on positron-emitting radiotracers

    International Nuclear Information System (INIS)

    Shakir, Dzhoshkun Ismail

    2014-01-01

    Positron-emitting radiotracers are an important part of nuclear medical imaging processes. Besides the very famous glucose analog [ 18 F]FDG, many not so well known ones exist, among them the particularly interesting amino acid-based tracers like [ 18 F]FET. Although peri-operative imaging with positron-emitting radiotracers has become state-of- the-art in cases of many types of cancer, their capability is not fully exploited in the operating room yet. In this thesis we explore two intra-operative nuclear imaging modalities exploiting different aspects of positron radiation towards quality assurance in challenging surgical treatment scenarios. The first modality freehand PET provides a tomographic image of a volume of interest and aims at minimizing invasiveness by assisting the surgeon in pinpointing target structures marked with a radiotracer. The second imaging modality epiphanography generates an image of the radiotracer distribution on a surface of interest and aims at providing a means for improving the control of tumor resection margins. The word epiphanography is a compound of the Greek words επιφανεια (epiphaneia) for surface and ζωγραφια (ographia) for image, and hence means the image of the surface similar to the compound τομοζ (tomos) for slice/volume and ζωγραφια (ographia) for image, meaning the image of the volume, i.e. tomography. To our knowledge this is the first use of the word epiphanography in the context of nuclear medical imaging. In this thesis we present our approach to modeling, developing and calibrating these two novel imaging modalities. In addition, we present our work towards their clinical integration. In the case of freehand PET, we have already acquired the first intra-operative datasets of a patient. We present this first experience in the operating room together with our phantom studies. In the case of epiphanography, we present our phantom studies with neurosurgeons towards the integration of this

  8. Calcium carbonate scaling kinetics determined from radiotracer experiments with calcium-47

    International Nuclear Information System (INIS)

    Turner, C.W.; Smith, D.W.

    1998-01-01

    The deposition rate of calcium carbonate on a heat-transfer surface has been measured using a calcium-47 radiotracer and compared to the measured rate of thermal fouling. The crystalline phase of calcium carbonate that precipitates depends on the degree of supersaturation at the heat-transfer surface, with aragonite precipitating at higher supersaturations and calcite precipitating at lower supersaturations. Whereas the mass deposition rates were constant with time, the thermal fouling rates decreased throughout the course of each experiment as a result of densification of the deposit. It is proposed that the densification was driven by the temperature gradient across the deposit together with the retrograde solubility of calcium carbonate. The temperature dependence of the deposition rate yielded an activation energy of 79 ± 4 kJ/mol for the precipitation of calcium carbonate on a heat-transfer surface. (author)

  9. Helium/solid powder O-ring leakage correlation experiments using a radiotracer

    International Nuclear Information System (INIS)

    Bild, R.W.; Leisher, W.B.; Weissman, S.H.; Seya, M.

    1984-01-01

    UO 2 definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or end of a test. The radiotracer method involves less labor and is much less susceptible to contamination than the previous method. Future work will investigate leakage past lubricated O-rings and time dependence of leakage. 1 reference, 1 table

  10. Effects of flow changes on radiotracer binding: Simultaneous measurement of neuroreceptor binding and cerebral blood flow modulation.

    Science.gov (United States)

    Sander, Christin Y; Mandeville, Joseph B; Wey, Hsiao-Ying; Catana, Ciprian; Hooker, Jacob M; Rosen, Bruce R

    2017-01-01

    The potential effects of changes in blood flow on the delivery and washout of radiotracers has been an ongoing question in PET bolus injection studies. This study provides practical insight into this topic by experimentally measuring cerebral blood flow (CBF) and neuroreceptor binding using simultaneous PET/MRI. Hypercapnic challenges (7% CO 2 ) were administered to non-human primates in order to induce controlled increases in CBF, measured with pseudo-continuous arterial spin labeling. Simultaneously, dopamine D 2 /D 3 receptor binding of [ 11 C]raclopride or [ 18 F]fallypride was monitored with dynamic PET. Experiments showed that neither time activity curves nor quantification of binding through binding potentials ( BP ND ) were measurably affected by CBF increases, which were larger than two-fold. Simulations of experimental procedures showed that even large changes in CBF should have little effect on the time activity curves of radiotracers, given a set of realistic assumptions. The proposed method can be applied to experimentally assess the flow sensitivity of other radiotracers. Results demonstrate that CBF changes, which often occur due to behavioral tasks or pharmacological challenges, do not affect PET [ 11 C]raclopride or [ 18 F]fallypride binding studies and their quantification. The results from this study suggest flow effects may have limited impact on many PET neuroreceptor tracers with similar properties.

  11. Radiotracer experiments on the uptake of radionuclides by mushrooms and vegetables

    International Nuclear Information System (INIS)

    Ban-Nai, Tadaaki; Muramatsu, Yasuyuki; Yoshida, Satoshi; Yanagisawa, Kei

    1996-01-01

    Radiotracer experiments were performed to study radionuclide uptake by mushrooms and plants. Four mushroom species, Hebeloma vinosophyllum, Flammulina velutipes, Agrocybe cylindracea and Coprinus phlyctidosporus were cultivated in a flask containing medium with the radiotracers 137 Cs, 85 Sr, 54 Mn, 60 Co and 65 Zn. Mushrooms tended to accumulate Cs, Mn and Zn. The concentration ratio of Cs between mushroom and medium ranged from 2.6 to 21. The highest was observed in H. vinospohyllum. The concentration ratio of Mn was about 10, while the ratio of Zn ranged from 15 to 30. No noticeable accumulations were found for Sr or Co. Transfer factors (TFs) of radionuclides from soil to leaf vegetables (cabbage, Chinese cabbage, komatsuna, spinach and lettuce) were also studied using Andosol (a representative Japanese soil). The TFs of 137 Cs, 85 Sr, 54 Mn, 60 Co and 65 Zn for edible parts of these vegetables were (mean value) 0.11, 0.24, 0.61, 0.05 and 0.52, respectively. The TFs of Mn, Co and Zn for spinach were higher than those for the other vegetables. The distributions of Cs in different organs of the leaf vegetables were rather uniform. The TFs of Sr and Mn were higher for older (outer) leaves than younger (inner) ones. In contrast to Sr and Mn, TFs of Zn for younger leaves were higher than those for older ones

  12. Combination of sealed source and radiotracer technique to understand malfunctioning in a chemical plant

    Energy Technology Data Exchange (ETDEWEB)

    Yelgaonkar, V.N. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)], E-mail: vivekyel@rediffmail.com; Jayakumar, T.K.; Singh, Sudhir; Sharma, M.K. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)

    2009-07-15

    Pure terphthalic acid (PTA) is produced by the oxidation of paraxylene in an oxidation reactor of a PTA plant. Since the reaction is exothermic, the temperature rises above 210 deg. C. Vapours formed in the reactor are passed through a series of heat exchangers and the cooled liquid is fed back to the reactor, which flows to the reactor by gravity. In one of the heat exchangers, improper flow distribution in the inlet and outlet pipelines was suspected. Maldistribution of flow in the heat exchanger was also suspected. Gamma scanning of the pipelines and a radiotracer experiment were carried out in the heat exchanger to study the malfunctioning. A specially fabricated pipe scanner was used to scan both 24 in diameter and 16 in diameter pipelines. From gamma scanning of the pipelines mostly on the bends, absence of the full bore flow of the liquid was observed. Presence of vapours along with the liquid could be obstructing the liquid flow, thereby causing the malfunctioning. A radiotracer experiment was also carried out to study the flow pattern in the heat exchanger. From the experiment, mean residence time of the heat exchanger was estimated as 470 s, which theoretically should be about 102 s. It indicated that the flow is decelerated in the heat exchanger because of the presence of vapour lock in the tube side.

  13. Measurement of residence time distribution of liquid phase in an industrial-scale continuous pulp digester using radiotracer technique.

    Science.gov (United States)

    Sheoran, Meenakshi; Goswami, Sunil; Pant, Harish J; Biswal, Jayashree; Sharma, Vijay K; Chandra, Avinash; Bhunia, Haripada; Bajpai, Pramod K; Rao, S Madhukar; Dash, A

    2016-05-01

    A series of radiotracer experiments was carried out to measure residence time distribution (RTD) of liquid phase (alkali) in an industrial-scale continuous pulp digester in a paper industry in India. Bromine-82 as ammonium bromide was used as a radiotracer. Experiments were carried out at different biomass and white liquor flow rates. The measured RTD data were treated and mean residence times in individual digester tubes as well in the whole digester were determined. The RTD was also analyzed to identify flow abnormalities and investigate flow dynamics of the liquid phase in the pulp digester. Flow channeling was observed in the first section (tube 1) of the digester. Both axial dispersion and tanks-in-series with backmixing models preceded with a plug flow component were used to simulate the measured RTD and quantify the degree of axial mixing. Based on the study, optimum conditions for operating the digester were proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Determination of Radiotracer Stability of Tritium-Labelled Compounds in Biological Studies; Determination de la Stabilite des Composes Trities Employes comme Indicateurs en Biologie; 041e 043f 0440 0435 0434 0414 043b ; Determinacion de la Estabilidad de los Compuestos Tritiados en los Estudios Biologicos Mediante Indicadores

    Energy Technology Data Exchange (ETDEWEB)

    Okita, G. T.; Spratt, J. L. [Argonne Cancer Research Hospital and Department of Pharmacology, University of Chicago, Chicago, IL (United States)

    1962-02-15

    The recent extensive use of tritium-labelled compounds in biological studies makes it imperative that investigators verify the radiotracer stability of tritiated compounds. Even purification of labelled compounds to constant specific activity does not preclude the possibility of the tritium atom exchanging with hydrogen within a biological system. Radiotracer stability can be demonstrated by various methods once, meticulous radiochemical purification of the labelled material has been effected. In this report three different methods for establishing radiotracer stability of tritiated compounds are described. One approach is to compare the biological half-life of a H{sup 3}-compound to that of a similar compound labelled with C{sup 14}. This method is especially applicable to endogenous substances which undergo isotopic dilution when administered to animals. Stability of exogenous compounds can be verified by a second method. Here it is only necessary to demonstrate no diminution in specific activity when the labelled material is re-isolated from biological samples. A third method, less time-consuming than the first, and applicable to both endogenous and exogenous material is the determination of H{sup 3} to C{sup 14} isotope ratio in a mixture of the same compound labelled with both isotopes. Identical isotope ratios before administration of the double-labelled material and after re-isolation from organs or excreta demonstrate radiotracer stability. This method is particularly applicable where isolation of minute amounts of material necessitates the use of non-radioactive carrier. Data demonstrating the use of these methods for the verification of radiotracer stability will be presented with special reference to labelled cholesterol, morphine and digitoxin as examples for the three respective methods. (author) [French] L'emploi, repandu depuis peu, de composes trities dans les etudes biologiques, impose aux chercheurs la necessite de verifier la stabilite de ces

  15. Characterization of a radiotracer-based 3-hydroxy-1-methyl peridine by its analogue Rhene

    International Nuclear Information System (INIS)

    Zitouni, Zeineb

    2010-01-01

    Since the discovery of artificial radioactivity in 1934, nuclear doctors have a variety of radioactive isotopes as indicators and markers. With these radioactive isotopes, it is possible to trace an atom or a chemical species without disrupting the physical behavior, chemical or biological. The branch of medicine and medical specialty now devoted to the use of radioactive elements for examination or treatment of patients, particularly the brain. Having a close relationship with radiobiology, radiation protection and Radiopharmacy, Nuclear Medicine Specialist is empowered to handle potentially dangerous isotope, observing precautions and regulations designed to reduce their risks. These radionuclides are used for exploration of cell kinetics, pharmacokinetics or for scans. Activities under this project led to the synthesis of N-methylferrocene, its characterization and its labeling with technetium 99 m. For the characterization of the radiotracer synthesized, we used to study the properties of complex similar models, labeled with rhenium. To verify and confirm this work, we propose the following perspectives: - Confirm the structure of N-methyl rhenium by nuclear magnetic resonance and single crystal X ray crystallography. - Develop and characterize new radiotracers brain.

  16. In vitro kinetic studies on the mechanism of oxygen-dependent cellular uptake of copper radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Jason P; Bell, Stephen G; Wong, Luet-Lok; Dilworth, Jonathan R [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA (United Kingdom); Giansiracusa, Jeffrey H [Department of Mathematics, Mathematical Institute, University of Oxford, 24-29 St Giles' , Oxford, OX1 3LB (United Kingdom)], E-mail: hollanj3@mskcc.org, E-mail: jasonpholland@gmail.com

    2009-04-07

    The development of hypoxia-selective radiopharmaceuticals for use as therapeutic and/or imaging agents is of vital importance for both early identification and treatment of cancer and in the design of new drugs. Radiotracers based on copper for use in positron emission tomography have received great attention due to the successful application of copper(II) bis(thiosemicarbazonato) complexes, such as [{sup 60/62/64}Cu(II)ATSM] and [{sup 60/62/64}Cu(II)PTSM], as markers for tumour hypoxia and blood perfusion, respectively. Recent work has led to the proposal of a revised mechanism of hypoxia-selective cellular uptake and retention of [Cu(II)ATSM]. The work presented here describes non-steady-state kinetic simulations in which the reported pO{sub 2}-dependent in vitro cellular uptake and retention of [{sup 64}Cu(II)ATSM] in EMT6 murine carcinoma cells has been modelled by using the revised mechanistic scheme. Non-steady-state (NSS) kinetic analysis reveals that the model is in very good agreement with the reported experimental data with a root-mean-squared error of less than 6% between the simulated and experimental cellular uptake profiles. Estimated rate constants are derived for the cellular uptake and washout (k{sub 1} = 9.8 {+-} 0.59 x 10{sup -4} s{sup -1} and k{sub 2} = 2.9 {+-} 0.17 x 10{sup -3} s{sup -1}), intracellular reduction (k{sub 3} = 5.2 {+-} 0.31 x 10{sup -2} s{sup -1}), reoxidation (k{sub 4} = 2.2 {+-} 0.13 mol{sup -1} dm{sup 3} s{sup -1}) and proton-mediated ligand dissociation (k{sub 5} = 9.0 {+-} 0.54 x 10{sup -5} s{sup -1}). Previous mechanisms focused on the reduction and reoxidation steps. However, the data suggest that the origins of hypoxia-selective retention may reside with the stability of the copper(I) anion with respect to protonation and ligand dissociation. In vitro kinetic studies using the nicotimamide adenine dinucleotide (NADH)-dependent ferredoxin reductase enzyme PuR isolated from the bacterium Rhodopseudomonas palustris have

  17. Radiotracer laboratory for agricultural research at the Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    Nashriyah Mat; Misman Sumin; Maizatul Akmam Mhd Nasir

    2007-01-01

    Radiotracer Laboratory for agricultural research at the Malaysian Nuclear Agency was established since 1990. It accommodates three laboratories, three chemical temporary storage compartments plus one compartment for storage of pressurized gas. This facility is situated in ground floor of Block 44, Agrotechnology and Biosciences Division, Dengkil Complex. Currently it houses a liquid scintillation counter, sample oxidizer, gas liquid chromatography, high performance liquid chromatography and auxiliary equipments. A road map for this laboratory will be discussed in relation with present scenario i.e. R and D service, training and consultancy provided by this laboratory; and future requirements and direction. (Author)

  18. Determination of mating frequency by radiotracer technique

    International Nuclear Information System (INIS)

    Hamid Miah, M.A.

    1978-01-01

    Radioisotope ( 32 P) was used to study the frequency of mating of an insect. The radioactivity counts correlated positively with the number of matings. Radioactivity was also detected from the eggs and excised embryos. This work suggests that radioisotope like ( 32 P) may be conveninently used to detect virginity and mating frequency of female insects without killing them. (author)

  19. Synthesis and characterization of a cerebral radiotracer

    International Nuclear Information System (INIS)

    Ben hamouda, Salem

    2010-01-01

    The development of nuclear medicine is based on research of new radiopharmaceuticals, in particular, relying on technetium-99m, the most used radioisotope in terms of availability and low cost. A similar study on Rhenium (185/187Re) is essential for monitoring physico-chemical studies due to the high specific activity of technetium-99m. During this work, we have synthesized and labeled with technetium the N-methyl-4-hydroxy piperidinyl ferrocenyl carboxylate. The marking is done by exchange of ligands between the iron group of ferrocene and tricabonyl technetium core. We have succeeded to synthesis the N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl rhenium (the molecular analogue of the technetium). We characterized it by MS, IR and NMR (1H, 13C) The structure of N-methyl-4-hydroxy piperidinyl carboxyl cyclopentadienyl tricarbonyl technetium is well justified.

  20. Measurement of residence time distribution of liquid phase in an industrial-scale continuous pulp digester using radiotracer technique

    International Nuclear Information System (INIS)

    Sheoran, Meenakshi; Goswami, Sunil; Pant, Harish J.; Biswal, Jayashree; Sharma, Vijay K.; Chandra, Avinash; Bhunia, Haripada; Bajpai, Pramod K.; Rao, S. Madhukar; Dash, A.

    2016-01-01

    A series of radiotracer experiments was carried out to measure residence time distribution (RTD) of liquid phase (alkali) in an industrial-scale continuous pulp digester in a paper industry in India. Bromine-82 as ammonium bromide was used as a radiotracer. Experiments were carried out at different biomass and white liquor flow rates. The measured RTD data were treated and mean residence times in individual digester tubes as well in the whole digester were determined. The RTD was also analyzed to identify flow abnormalities and investigate flow dynamics of the liquid phase in the pulp digester. Flow channeling was observed in the first section (tube 1) of the digester. Both axial dispersion and tanks-in-series with backmixing models preceded with a plug flow component were used to simulate the measured RTD and quantify the degree of axial mixing. Based on the study, optimum conditions for operating the digester were proposed. - Highlights: • Radiotracer experiments were conducted to measure RTD of liquid phase in a pulp digester • Mean residence times of white liquor were measured • Axial dispersion and tanks-in-series models were used to investigate flow patterns • Parallel flow paths were observed in first section of the digester • Optimized flow rates of biomass and liquor were obtained

  1. Chemical fate of the nicotinic acetylcholinergic radiotracer [123I]5-IA-85380 in baboon brain and plasma

    International Nuclear Information System (INIS)

    Baldwin, Ronald M.; Zoghbi, Sami S.; Staley, Julie K.; Brenner, Eric; Al-Tikriti, Mohammed S.; Amici, Louis; Fujita, Masahiro; Innis, Robert B.; Tamagnan, Gilles

    2006-01-01

    The fate of the nicotinic acetylcholinergic receptor radiotracer [ 123 I]5-IA-85380 ([ 123 I]5-IA) was studied in baboon by analyzing the chemical composition of brain tissue and plasma after intravenous administration of the tracer. Acetonitrile denaturation and high-performance liquid chromatography (HPLC) analysis showed predominantly unchanged (91-98%) parent tracer in all brain tissues examined, compared to significant metabolism (23% parent) in the plasma at 90 min postinjection, and control tissue recovery of 95-98%. [ 123 I]5-IA was distributed to the thalamus with a standardized uptake value of 9.2 (0.04% dose/g) or a concentration 5.8 times higher than that of the cerebellum. The HPLC behavior of a synthesized sample of one hypothesized metabolite, 5-iodo-3-pyridinol (5-IP), was consistent with plasma radiometabolite fraction. Since only parent radiotracer compound was found in brain tissue, these results add confidence that information derived from single photon emission computed tomography images of 123 I activity in the brain after [ 123 I]5-IA administration can be interpreted as distribution of an intact radiotracer

  2. Affective Dependence and Aggression: An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Filippo Petruccelli

    2014-01-01

    Full Text Available Introduction. Emotionally dependent subjects may engage in controlling, restrictive, and aggressive behaviours, which limit their partner’s autonomy. The underlying causes of such behaviours are not solely based on levels of aggression, but act as a mean of maintaining the subject’s own sense of self-worth, identity, and general functioning. Objective. The aim of the paper is to explore the correlation between affective dependency and reactive/proactive aggression and to evaluate individual differences as predisposing factors for aggressive behaviour and emotional dependency. Methods. The Spouse-Specific Dependency Scale (SSDS and the Reactive Proactive Questionnaire (RPQ were administered to a sample of 3375 subjects. Results. In the whole sample, a positive correlation between emotional dependency and proactive aggression was identified. Differences with regard to sex, age group, and geographical distribution were evidenced for the scores of the different scales. Conclusion. A fundamental distinction between reactive and proactive aggression was observed, anchoring proactive aggression more strictly to emotional dependency. Sociocultural and demographical variables, together with the previous structuring of attachment styles, help to determine the scope, frequency, and intensity of the demands made to the partner, as well as to feed the fears of loss, abandonment, or betrayal.

  3. Affective dependence and aggression: an exploratory study.

    Science.gov (United States)

    Petruccelli, Filippo; Diotaiuti, Pierluigi; Verrastro, Valeria; Petruccelli, Irene; Federico, Roberta; Martinotti, Giovanni; Fossati, Andrea; Di Giannantonio, Massimo; Janiri, Luigi

    2014-01-01

    Emotionally dependent subjects may engage in controlling, restrictive, and aggressive behaviours, which limit their partner's autonomy. The underlying causes of such behaviours are not solely based on levels of aggression, but act as a mean of maintaining the subject's own sense of self-worth, identity, and general functioning. The aim of the paper is to explore the correlation between affective dependency and reactive/proactive aggression and to evaluate individual differences as predisposing factors for aggressive behaviour and emotional dependency. The Spouse-Specific Dependency Scale (SSDS) and the Reactive Proactive Questionnaire (RPQ) were administered to a sample of 3375 subjects. In the whole sample, a positive correlation between emotional dependency and proactive aggression was identified. Differences with regard to sex, age group, and geographical distribution were evidenced for the scores of the different scales. A fundamental distinction between reactive and proactive aggression was observed, anchoring proactive aggression more strictly to emotional dependency. Sociocultural and demographical variables, together with the previous structuring of attachment styles, help to determine the scope, frequency, and intensity of the demands made to the partner, as well as to feed the fears of loss, abandonment, or betrayal.

  4. Radiotracer experiments on lignin reactions, 2

    International Nuclear Information System (INIS)

    Terashima, Noritsugu; Araki, Hiroshi; Suganuma, Nobuo.

    1977-01-01

    The behavior of the specific carbon atoms of lignin during the cooking process was studied. Pine wood meal containing the protolignin labelled with 14-C was prepared, and treated under sulfate cooking conditions. The incorporation and distribution of radioactivity were traced in three fractions separated from the black liquor according to their solubilities and molecular weights. The gamma position carbon at the end of side chain of phenylpropane unit in lignin was eliminated easily from the high molecular weight portion in considerable extent during the cooking process, and a part of the eliminated carbon condenses again with the aromatic ring. However, a large portion of the eliminated gamma-carbon was found in the low molecular fraction of water soluble part of the black liquor. The radioactivity of alpha-carbons in the side chains adjacent to aromatic rings was found to be distributed in three fractions similarly to that of beta-carbons, except that the incorporation of radioactivity of alpha-carbons was slightly low in high molecular fraction, and slightly high in low molecular water soluble fraction as compared with that of beta-carbons and aromatic ring carbons. The number of residual carbon atoms per one monomer unit in high molecular kraft lignin was calculated from the specific incorporation ratio of radioactivity. The carbon skelton was estimated and the molecular formula was given by the elementary analysis and molecular weight determination. (Iwakiri, K.)

  5. Determination of oil reservoir radiotracer (S14CN−) in a single step using a plastic scintillator extractive resin

    International Nuclear Information System (INIS)

    Bagán, H.; Tarancón, A.; Stavsetra, L.; Rauret, G.; García, J.F.

    2012-01-01

    Highlights: ► A new procedure for S 14 CN − radiotracer determination using PS resin was established. ► The minimum detectable activity for a 100 mL sample is 0.08 Bq L −1 . ► The minimum quantifiable activity for a 100 mL sample is 0.31 Bq L −1 . ► PS resin is capable to quantify S 14 CN − radiotracer samples with errors lower than 5%. ► PS resin is also capable to quantify complex matrices obtained from oil reservoirs. - Abstract: The analysis of radiotracers is important in the study of oil reservoir dynamics. One of the most widely used radiotracer is S 14 CN − . Prior to activity measurements by Liquid Scintillation (LS), routine determinations require the pretreatment steps of purification and concentration of the samples using anion exchange columns. The final elution media produces samples with high salt concentration that may lead to problems with phase separation during the LS measurement. Plastic Scintillation (PS) is an alternative technique that provides a solid surface that can be used as a platform for the immobilisation of selective extractants to obtain a PS resin. The proposed procedure unifies chemical separation and sample measurement preparation in a single step, serving to reduce the number of reagents needed and manpower required for the analysis while also avoiding mixed waste production by LS. The objective of this study is to develop a PS resin for the determination of 14 C-labelled thiocyanate radiotracer in water samples. For this purpose, the immobilisation procedure was optimised, including optimisation of the proportion of PS microspheres:extractant and the use of a control blank to monitor the PS resin immobilisation process. The breakthrough volume was studied and the detection and quantification limits for 100 mL of sample were determined to be 0.08 Bq L −1 and 0.31 Bq L −1 , respectively. The established procedure was applied to active samples from oil reservoirs and errors lower than 5% in the sample

  6. The extraction of low-concentrations of gold(I) with 198Au as a radiotracer

    International Nuclear Information System (INIS)

    Jianzhun Jiang; Chunli Liu; Weijin Zhou; Hongcheng Gao

    2002-01-01

    The solvent extraction of gold from alkaline cyanide solution was studied by using 198 Au as a radiotracer. The influence of several variables on the gold extraction, including the concentration of gold, the molar ratio of extractants to gold(I), the volume percentage of cosolvent and the pH value of the aqueous phase, was investigated. The results indicated that the radioactive tracer technique is a quick, accurate, and convenient tool to investigate the extraction behavior of an element existing in low concentrations. The experimental results indicated that the studied amines, tetradecyldimethylbenzylammonium chloride, N1923 and tri-n-octylamine, could be used as extractants for the recovery of gold from aqueous alkaline cyanide solutions. (author)

  7. Deposition of heavy metals in rat hair and organs using radiotracers

    International Nuclear Information System (INIS)

    Tykva, R.; Votruba, I.; Vesely, J.; Merta, A.; Hanzlik, J.

    1993-01-01

    The basic scope of this Project consisted in the investigation of binding of individual radiometals to soluble proteins isolated form rat hair, epidermis, blood plasma, kidney and liver and in the study of putative specific transport proteins. Several types of substances, labelled with 210 Pb, 203 Hg or 109 Cd, were administered to adult Wistar A male rats kept in metabolic cages. The protein extract was subject to PAGE in the presence of SDS. It was found that lead, mercury and cadmium is tightly bound to soluble proteins from fair, plasma and tissues. The 210 Pb distribution patterns in proteins were estimated. Lead in hair has high affinity towards sulphur-rich proteins, while covalent binding of mercury via sulphhydryl groups corresponds to our analysis. The established and verified methods including investigation of binding of different elements to proteins without radiotracers represents a reliable basis for further studies. (author). 18 refs, 4 figs, 5 tabs

  8. Characterization of electrochemical cell for production of radiotracer in organic medium

    International Nuclear Information System (INIS)

    Kenup-Hernandes, Hericka O.; Brandão, Luís Eduardo B.; Silva, Ademir X. da; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    In a petrochemical plant, precise knowledge of the flow of the compounds that flow inside the pipelines that carry oil and these derivatives is crucial. To perform these controls a series of flow meters are installed inside ducts in direct contact with the fluid to be monitored. This invasive method presents a great limitation because the oil aggressive proprieties that require these measurement devices are subjected to frequent calibrations which, in turn, cause the stoppage of the plant and low productivity. In this sense, radiotracers has been used in conjunction with the time transient method, by configuring a precise and non-invasive measurement technique. This work presents the study of the characterization of an electrolytic cell model for the production of petroleum derivatives labeled with Iodine-123 for use as radiotracer in the measurement of flow in ducts and the time transient method. Labelling of organic compounds usually a sequence of solvent separation and extraction steps which, when used for labeling oil and oil derivatives it causes high gamma exposition for the operator at considerable dose rates due to the need for direct interaction with the marking system. The objective of this work is to develop a cell model that is part of a compact, automatically operated labelling system with physics and chemistry parameters defined to optimize the organic phase labelling processes of petroleum derivatives. The labelling cell is composed of a cylindrical reaction vessel where the aqueous medium containing the iodine-123 in the form of sodium iodide (NaI-I123) is inserted with about 2 mCi of activity and the organic medium. In the system are introduced, two Platinum electrodes where a voltage of 0. 8 V is applied. This system allows the production of radiotracer for a rapid pulse injection. The results show that there was no significant variation of the stability of the system in the temperature range of 25 °C to 40 °C and showed a labelling efficiency

  9. Characterization of electrochemical cell for production of radiotracer in organic medium

    Energy Technology Data Exchange (ETDEWEB)

    Kenup-Hernandes, Hericka O.; Brandão, Luís Eduardo B.; Silva, Ademir X. da, E-mail: hkenup@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-11-01

    In a petrochemical plant, precise knowledge of the flow of the compounds that flow inside the pipelines that carry oil and these derivatives is crucial. To perform these controls a series of flow meters are installed inside ducts in direct contact with the fluid to be monitored. This invasive method presents a great limitation because the oil aggressive proprieties that require these measurement devices are subjected to frequent calibrations which, in turn, cause the stoppage of the plant and low productivity. In this sense, radiotracers has been used in conjunction with the time transient method, by configuring a precise and non-invasive measurement technique. This work presents the study of the characterization of an electrolytic cell model for the production of petroleum derivatives labeled with Iodine-123 for use as radiotracer in the measurement of flow in ducts and the time transient method. Labelling of organic compounds usually a sequence of solvent separation and extraction steps which, when used for labeling oil and oil derivatives it causes high gamma exposition for the operator at considerable dose rates due to the need for direct interaction with the marking system. The objective of this work is to develop a cell model that is part of a compact, automatically operated labelling system with physics and chemistry parameters defined to optimize the organic phase labelling processes of petroleum derivatives. The labelling cell is composed of a cylindrical reaction vessel where the aqueous medium containing the iodine-123 in the form of sodium iodide (NaI-I123) is inserted with about 2 mCi of activity and the organic medium. In the system are introduced, two Platinum electrodes where a voltage of 0. 8 V is applied. This system allows the production of radiotracer for a rapid pulse injection. The results show that there was no significant variation of the stability of the system in the temperature range of 25 °C to 40 °C and showed a labelling efficiency

  10. Experimental observation of silver and gold penetration into dental ceramic by means of a radiotracer technique

    International Nuclear Information System (INIS)

    Moya, F.; Payan, J.; Bernardini, J.; Moya, E.G.

    1987-01-01

    A radiotracer technique was used to study silver and gold diffusion into dental porcelain under experimental conditions close to the real conditions in prosthetic laboratories for porcelain bakes. It was clearly shown that these non-oxidizable elements were able to diffuse into the ceramic as well as oxidizable ones. The penetration depth varied widely according to the element. The ratio DAg/DAu was about 10(3) around 850 degrees C. In contrast to gold, the silver diffusion rate was high enough to allow silver, from the metallic alloy, to be present at the external ceramic surface after diffusion into the ceramic. Hence, the greening of dental porcelains baked on silver-rich alloys could be explained mainly by a solid-state diffusion mechanism

  11. Flow Rate Measurement Using 99mTc Radiotracer Method in a Pipe Installation

    International Nuclear Information System (INIS)

    Sipaun, S. M.; Bakar, A. Q. Abu; Othman, N.; Shaari, M. R.; Adnan, M. A. K.; Yusof, J. Mohd; Demanah, R.

    2010-01-01

    Flow rate is a significant parameter for managing processes in chemical processing plants and water processing facility. Accurate measurement of the flow rate allows engineers to monitor the delivery of process material, which in turn impacts a plant's capacity to produce their products. One of the available methods for determining the flow rate of a process material is by introducing a radiotracer to the system that mimics the material's flow pattern. In this study, a low activity Technetium-99m radioisotope was injected into a water piping setup and the 2'' x 2'' NaI (Tl) detectors were calibrated to detect spectrum peaks at specific points of the pipe installation. Using pulse velocity method, water flow rate was determined to be 11.3 litres per minute. For the sampling method, at different pump capacity, the flow rate was 15.0 litres per minute.

  12. Development of radiotracer technology and nucleonic control systems - Development of leakage monitoring system using radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Choon; Lee, Doon Sung [Seoil College, Seoul (Korea); Cho, Yong Suk [Konyang University, Nonsan (Korea); Shin, Seung Kwon [Sungkyunkwan University, Seoul (Korea)

    1999-04-01

    This is the equipment to find out the leakage of an oil pipeline and a water pipe reclaimed from the underground, using a Radioisotopes. For this purpose, small sized, light weight and water proofed Detection Pig in high voltage is to be designed and produced as to develope a radiation detector, high voltage power supply circuit, measurement circuit, data storage circuit, and a remote on/off function, etc. In this study, high-voltage producing circuit, an amplifier, count rate circuit, processing circuit, and radiosignal treatment part will be used as a basic material to develope a radiotracer, a radiation measuring and using equipment. And it will promote the localization of the radiation applied measuring system. As the results, domestic equipment industry will be improved a great deal. 22 refs., 22 figs., 8 tabs. (Author)

  13. Design and evaluation of radiotracers for determination of regional cerebral blood flow with PET

    International Nuclear Information System (INIS)

    Lambrecht, R.M.; Duncan, C.C.; Shiue, C.Y.

    1982-01-01

    The tracer kinetics of 4-Fluoro( 18 F)-, 4-Bromo( 82 Br)- and 4-Iodo( 125 I)-antipyrine and 15 O-water were compared in a cat or baboon animal model. First-pass cerebral extraction and clearance with alterations in PaCO 2 were measured for whole brain. The Renkin/Crone model was used to evaluate brain capillary permeability-surface area product for 4- 18 FAP in cats. Positron-emission-tomographic measurements required development of an instrument and technique for control of the arterial concentration of the radiotracer as a ramp function, so that tracer concentration changes due to radioactive decay or altered physiological processes could be accurately described with PET. Pharmacokinetic and tissue-distribution studies in cats were used to determine dosimetry for 4- 18 FAP. 4-Bromoantipyrine labeled with 78 Br (t = 6.5 m) is suggested as a tracer for determination of rCBF with PET

  14. Radiotracer diffusion in semiconductors and metallic compounds using short-lived isotopes

    CERN Multimedia

    Deicher, M; Kronenberg, J; Wagner, F E

    The transport of atoms in solids is of central importance for solid state physics, chemistry, metallurgy, and material sciences. Since the mobility of atoms in solids contributes to many physical phenomena the study of diffusion processes is of fundamental interest for solid state physics. Diffusion processes were frequently investigated using radioactive isotopes (radiotracers). The application of short-lived isotopes delivered at ISOLDE extends substantially the possibilities of investigating diffusion processes in solids. In particular, a new experimental set-up to be installed at ISOLDE in this year will enable the use of radioactive isotopes with half-lives down to minutes. Alternatively, in special cases diffusion processes can be investigated with help of hyperfine techniques on an atomic scale, like by perturbed $\\gamma \\gamma$-angular correlation (PAC). Here, the motion of the atom of interest becomes visible directly via characteristic changes in the measured PAC spectra.

  15. Systemic catechol-O-methyl transferase inhibition enables the D1 agonist radiotracer R-[11C]SKF 82957

    International Nuclear Information System (INIS)

    Palner, Mikael; McCormick, Patrick; Parkes, Jun; Knudsen, Gitte M.; Wilson, Alan A.

    2010-01-01

    Introduction: R-[ 11 C]-SKF 82957 is a high-affinity and potent dopamine D 1 receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway, facilitating the use of R-[ 11 C]-SKF 82957 to image the high-affinity state of the dopamine D 1 receptor with PET. Methods: R-[ 11 C]SKF 82957 was administered to untreated and COMT inhibitor-treated conscious rats, and the radioactive metabolites present in the brain and plasma were quantified by HPLC. Under optimal conditions, cerebral uptake and dopamine D 1 binding of R-[ 11 C]SKF 82957 were measured ex vivo. In addition, pharmacological challenges with the receptor antagonist SCH 23390, amphetamine, the dopamine reuptake inhibitor RTI-32 and the dopamine hydroxylase inhibitor α-methyl-p-tyrosine were performed to study the specificity and sensitivity of R-[ 11 C]-SKF 82957 dopamine D 1 binding in COMT-inhibited animals. Results: Treatment with the COMT inhibitor tolcapone was associated with a dose-dependent (EC 90 5.3±4.3 mg/kg) reduction in the lipophilic metabolite. Tolcapone treatment (20 mg/kg) also resulted in a significant increase in the striatum/cerebellum ratio of R-[ 11 C]SKF 82957, from 15 (controls) to 24. Treatment with the dopamine D 1 antagonist SCH 23390 reduced the striatal binding to the levels of the cerebellum, demonstrating a high specificity and selectivity of R-[ 11 C]SKF 82957 binding. Conclusions: Pre-treatment with the COMT inhibitor tolcapone inhibits formation of an interfering metabolite of R-[ 11 C]SKF 82957. Under such conditions, R-[ 11 C]SKF 82957 demonstrates high potential as the first agonist radiotracer for imaging the dopamine D 1 receptor by PET.

  16. Amyloid PET imaging in Alzheimer's disease: a comparison of three radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Landau, S.M.; Jagust, W.J. [University of California, Berkeley, Helen Wills Neuroscience Institute, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Thomas, B.A. [University College London, Institute of Nuclear Medicine, London (United Kingdom); Thurfjell, L. [GE Healthcare, Uppsala (Sweden); Schmidt, M. [Janssen Pharmaceutica, NV, Beerse (Belgium); Margolin, R. [Janssen Alzheimer Immunotherapy, South San Francisco, CA (United States); Mintun, M.; Pontecorvo, M. [Avid Radiopharmaceuticals, Inc., Philadelphia, PA (United States); Baker, S.L. [Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Collaboration: The Alzheimer' s Disease Neuroimaging Initiative

    2014-07-15

    The increasing use of amyloid PET in Alzheimer's disease research and clinical trials has motivated efforts to standardize methodology. We compared retention of the {sup 11}C radiotracer Pittsburgh Compound B (PiB) and that of two {sup 18}F amyloid radiotracers (florbetapir and flutemetamol) using two study populations. We also examined the feasibility of converting between tracer-specific measures, using PiB as the common link between the two {sup 18}F tracers. One group of 40 subjects underwent PiB and flutemetamol imaging sessions and a separate group of 32 subjects underwent PiB and florbetapir imaging sessions. We compared cortical and white matter retention for each {sup 18}F tracer relative to that of PiB, as well as retention in several reference regions and image analysis methods. Correlations between tracer pairs were used to convert tracer-specific threshold values for amyloid positivity between tracers. Cortical retention for each pair of tracers was strongly correlated regardless of reference region (PiB-flutemetamol, ρ = 0.84-0.99; PiB-florbetapir, ρ = 0.83-0.97) and analysis method (ρ = 0.90-0.99). Compared to PiB, flutemetamol had higher white matter retention, while florbetapir had lower cortical retention. Two previously established independent thresholds for amyloid positivity were highly consistent when values were converted between tracer pairs. Despite differing white and grey matter retention characteristics, cortical retention for each {sup 18}F tracer was highly correlated with that of PiB, enabling conversion of thresholds across tracer measurement scales with a high level of internal consistency. Standardization of analysis methods and measurement scales may facilitate the comparison of amyloid PET data obtained using different tracers. (orig.)

  17. [67Ga]Gallium-complex with 2-acetylpyridine N4-ortho fluorophenylthiosemicarbazone as a radiotracer for brain tumor diagnosis

    International Nuclear Information System (INIS)

    Pesquero, Jorge L.

    2011-01-01

    The aim of this work was to develop a 67 Ga-based SPECT imaging agent derived from 2-acetylpyridine N4-orthofluorophenyl - thiosemicarbazone (PhoF). For this purpose, PhoF was radiolabeled using 67 Ga as radiotracer, and after quality control analysis its biodistribution and SPECT imaging were evaluated on Swiss mice and Nude mice bearing glioblastoma multiform tumor (U87-MG). The labelling of PhoF with 67 GaCl 3 was performed in methanol for 30 minutes at room temperature. Radiochemical analyses were done by HPLC with radioactivity detection. 67 Ga- PhoF was successful produced with 97.5 ± 0.6% of radiochemical purity and high specific activity (1.0 TBq /mmol). 67 Ga- PhoF showed to be a stable compound keeping its stability, when stored at 2-4 deg C. In biodistribution studies, 67 Ga- PhoF displayed not only a significant tumor uptake, but also rapid blood clearance (T 1/2 fast phase = 3.7 min. and T 1/2 slow phase = 127.2 min.) and low accumulations in non target tissues, resulting in high target-to-non target ratios. Scintigraphic images of 67 Ga- PhoF in nude mice bearing U87-MG tumor showed a significant activity in tumor (∼ 7% of total activity) and tumor-to-normal tissue ratio was more than 10-fold higher depending on the organ. Our results suggest that 67 Ga-PhoF possess indispensable characteristics for a good radiopharmaceutical for brain tumor diagnosis. (author)

  18. [{sup 67}Ga]Gallium-complex with 2-acetylpyridine N4-ortho fluorophenylthiosemicarbazone as a radiotracer for brain tumor diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Pesquero, Jorge L. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisiologia e Biofisica; Pujatti, Priscilla B.; Araujo, Elaine B. de [Instituto de Pesquisas Energeticas Nucleares (DIRF/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia; Lessa, Josane A.; Beraldo, Heloisa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Soares, Marcella A.; Santos, Raquel G. dos, E-mail: santosr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The aim of this work was to develop a {sup 67}Ga-based SPECT imaging agent derived from 2-acetylpyridine N4-orthofluorophenyl - thiosemicarbazone (PhoF). For this purpose, PhoF was radiolabeled using {sup 67}Ga as radiotracer, and after quality control analysis its biodistribution and SPECT imaging were evaluated on Swiss mice and Nude mice bearing glioblastoma multiform tumor (U87-MG). The labelling of PhoF with {sup 67}GaCl{sub 3} was performed in methanol for 30 minutes at room temperature. Radiochemical analyses were done by HPLC with radioactivity detection. {sup 67}Ga- PhoF was successful produced with 97.5 {+-} 0.6% of radiochemical purity and high specific activity (1.0 TBq /mmol). {sup 67}Ga- PhoF showed to be a stable compound keeping its stability, when stored at 2-4 deg C. In biodistribution studies, {sup 67}Ga- PhoF displayed not only a significant tumor uptake, but also rapid blood clearance (T{sub 1/2} {sub fast} {sub phase}= 3.7 min. and T{sub 1/2} {sub slow} {sub phase}= 127.2 min.) and low accumulations in non target tissues, resulting in high target-to-non target ratios. Scintigraphic images of {sup 67}Ga- PhoF in nude mice bearing U87-MG tumor showed a significant activity in tumor ({approx} 7% of total activity) and tumor-to-normal tissue ratio was more than 10-fold higher depending on the organ. Our results suggest that {sup 67}Ga-PhoF possess indispensable characteristics for a good radiopharmaceutical for brain tumor diagnosis. (author)

  19. Preparation and study of thickness dependent electrical ...

    Indian Academy of Sciences (India)

    Unknown

    there are only a few reports on ZnS by CBD where the main objective is the study of ZnxCd1–xS thin films (Padam et al 1988; Lokhande 1991). Chemical deposition of ZnS thin films has been reported earlier using different zinc ion releasing sources such as zinc sulphate, zinc chloride etc. In the present case, ZnS films ...

  20. Status and perspective on radiotracer technology and development of its equipment in Korea

    International Nuclear Information System (INIS)

    Kim, Jong Bum; Jung, Sung Hee; Jin, Joon Ha

    2003-01-01

    The Korean tracer team was organized under the regular research project in the middle of 1990s. The objective of the project is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems. The Korean tracer team started with basic tracer technologies and basic tools for radiotracer experiment. Under the research project, various equipments and skills for radiotracer have been developed. With these skill and equipment, there have been several demonstration experiments in petrochemical industry and waste water treatment facilities. The direction of research using radiotracer technology is highly reflected by each country's industrial situation. There is overview on how the tracer technology has applied to the industries in Korea in this paper. And the case on the application of radiotracer technology and the development of its equipment in Korea are also introduced in this paper

  1. Studies of vitamin K-dependent carboxylase

    International Nuclear Information System (INIS)

    Wood, G.M.

    1986-01-01

    Carboxylase was studied in detergent solubilized rat liver microsomes, using the peptide substrate Phe-Leu-[γ- 3 H]-Glu-Glu-Leu. Cleavage of the γ-C-H bond in Glu was measured as the release of 3 H from this peptide to water, carboxylation was measured as the incorporation of H 14 CO 3 -into the peptide, and KO formation was measured by an HPLC assay. All three products could be measured simultaneously, and this system was used to examine the effects of cyanide, manganese, tetrachloropyridinol, and Boc-SerP-SerP-Leu-OMe on the separate steps of the carboxylase reaction. Vitamin K-epoxide formation was studied separately from the other reactions, and it was found that in the absence of a Glu-containing substrate, carboxylase catalyzed the uncoupled formation of KO from KH 2 and O 2 . The stoichiometry of product formation (GLa, KO, and γ-protons) was measured, and the results obtained were all in agreement with the values predicted from the proposed mechanism. When all of the substrates were saturating, the stoichiometry of γ-C-H bond cleavage, carboxylation, and KO formation was 1:1:1

  2. Radioimmunoassay kit formulation and its validation for serum progesterone using progesterone radiotracer purified by gel filtration

    International Nuclear Information System (INIS)

    Karir, T.; Pal, N.; Sivaprasad, N.

    2003-01-01

    Purification of the radioiodinated progesterone tyrosine methyl ester conjugate by gel filtration and the development, optimization and clinical validation of a direct radioimmunoassay (RIA) of progesterone using this radiotracer are described. High purity radiotracer is essential for the error free performance of any RIA. Progesterone 11α hemisuccinate was conjugated to tyrosine methyl ester (TME) by the mixed anhydride method and this conjugate was then radioiodinated by the chloramine-T method. Purification of the radioiodinated product was carried out by gel filtration. About 12 batches of the radiotracer were prepared and purified. The purification by gel filtration gave reproducible elution pattern and purity. The radiotracer thus purified was found to have consistent quality as compared to that of any other purification methods. Non-specific binding of the radiotracer was found to be 95% as checked by paper electrophoresis. The stability (retention of the immunoreactivity) of the radiotracer was two to three months. No appreciable changes in the assay characteristics were observed during this period. The assay involved 3 hours incubation of progesterone antibody with individual standards or sample and radiotracer at room temperature. The optimized assay was then validated for internal and external quality control parameters. A RIA kit was then formulated with this radiotracer for estimation of progesterone in serum. The assay kit consisted of lyophilized individual standards ranging from 0.25 to 50 ng/ml. The clinical performance of the developed kit was compared with that of a commercial ELISA kit and a correlation of 0.94 was observed. (author)

  3. A comparative study of self-regulation in substance dependent and non-dependent individuals.

    Science.gov (United States)

    Bakhshani, Nour Mohammad; Hosseinbor, Mohsen

    2013-08-05

    Several factors influence the beginning and maintenance of substance use. The purpose of this study was to examine as well as to compare 'self-regulation' in both substance dependent and non-substance dependent individuals. In a cross-sectional study 228 (118 substance dependent and 110 with no history of using substance) participants aged 16-55 were recruited. All of the participants were asked to complete the Self-Regulation Inventory (SRI-25) and a demographic characteristics data checklist. Data was analyzed using descriptive statistics (frequency, mean and standard deviation) and the t-test. The results showed significant differences between substance dependent and non- substance dependent groups in all the scales of the self-regulation inventory including positive actions, controllability, expression of feelings and needs, assertiveness, and well-being seeking (p<0.01). Self-regulation and self-control skills in drug dependent individuals are lower than those without substance dependence individuals. It is concluded that substance use may related to a deficiency in self-control and regulation of feelings. Therefore, for prevention and treatment of substance dependence disorder, it is necessary to work out and exploit strategies that include the improvement of self-regulation.

  4. Study of translocation of photosynthate in grapes with radiotracers with the dual purpose of increasing grape production and improving the technology required for the evaluation of the photosynthetic yield of other crops

    International Nuclear Information System (INIS)

    Balcar, J.

    1984-05-01

    Using [ 14 C]-CO 2 to label the products of photosynthesis formed at each leaf on developing, fruiting grape stems the pattern of translocation of sugar to competing ''sinks'' was determined. The studies, which used four economically important Uruguayan wine-grape varieties in field trials, established that the upper parts of the stems were 'parasitic' in that their leaves did not contribute sugars to grape cluster growth. From these results a technique was developed for shortening shoots which resulted in increased sugar content of clusters. Further research on ''source-sink'' relationships in grape will emphasis the role of plant growth regulators and their possible use in agronomic practice

  5. Reactor and /or accelerator: general remarks on strategic considerations in sourcing/producing radiopharmaceuticals and radiotracer for the Philippines

    International Nuclear Information System (INIS)

    Nazarea, A.D.

    1996-01-01

    The most important sources of radionuclides in the world are particle accelerators and nuclear reactors. Since the late 1940's many radiotracers and radiopharmaceuticals have been innovated and conceived, designed, produced and applied in important industrial and clinical/ biomedical settings. For example in the health area, reactor-produced radionuclides have become indispensable for diagnostic imaging involving, in its most recent and advanced development, radioimmunoscintigraphy, which exploits the exquisite ligand-specificity of monoclonal antibodies, reagents which in turn are the products of advances in biotechnology. Thus far, one of the most indispensable radiopharmaceuticals has been 99m Tc, which is usually obtained as a daughter decay product of 99 Mo. In January 1991, some questions about the stability of the worldwide commercial supply of 99 Mo became highlighted when the major commercial world producer of 99 Mo, Nordion International, shut down its facilities temporarily in Canada due to contamination in its main reactor building (see for instance relevant newsbrief in J. Nuclear Medicine (1991): 'Industry agrees to join DOE study of domestic moly-99 production'). With the above background, my remarks will attempt to open discussions on strategic considerations relevant to questions of 'self reliance' in radiotracers/radiopharmaceutical production in the Philippines. For instance, the relevant question of sourcing local radionuclide needs from a fully functioning multipurpose cyclotron facility within the country that will then supply the needs of the local industrial, biomedical (including research) and health sectors; and possibly, eventually acquiring the capability to export to nearby countries longer-lived radiotracers and radiopharmaceuticals

  6. Development of [11C]-α-aminoisobutyric acid and [18F]-haloperidol as substrate-specific radiotracers

    International Nuclear Information System (INIS)

    Zanzonico, P.B.

    1982-01-01

    In light of the emergence of positron emission tomography (PET), two new substrate-specific radiotracers have been synthesized and evaluated as potential agents for the study of specific physiological processes: [1- 11 C]-α-aminoisobutyric acid ([1- 11 C]-AIB), a transport system-specific radiotracer for tumor localization and for the assessment of amino acid transport in vivo; and [ 18 F]-haloperidoll, a receptor-binding radiotracer for the assessment of brain dopamine receptors in vivo. AIB, a non-metabolized amino acid, accumulates in cells, particularly malignant cells, via the A type, or ''alanine-preferring'', amino acid transport system [1- 11 C]-AIB in normal and in treated and untreated tumor-bearing rats, in tumor-bearing dogs, and in a tumor-bearing patient indicate rapid blood clearance and, concomitantly, rapid tissue localization, with slow net redistribution. Generally, there was selective localization in the kidney, in the liver, and in the pancreas, as well as in various tumors. The canine tumors and the human tumor were well visualized by external scintigraphy, especially when utilizing PET. [ 18 F]-Haloperidol, a dopamine receptor-binding neuroleptic of the butyrophenone series widely used in the management of schizophrenia was prepared via the Balz-Schiemann reaction. As the haloperdol dose administered to mice was increased from 0.01 to 1000 μg/kg, the relative concentration (μCi found per gm tisue sample/μCi injected per gm body mass) of [ 18 F]-haloperidol at 1 hr decreased from 30 to 1.0 in the striatum and from 8.0 to 1.0 in the cerebellum. The decrease in striatum radioactivity reflects competition between labeled and unlabeled haloperidol for dopamine receptors

  7. Improving phosphorus availability from Patos phosphate rock for Eucalyptus: a study with 32P radiotracer; Melhorando a disponibilidade de fosforo da rocha fosforica de Patos para eucalipto: um estudo com radiotracador 32P

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, Felipe Carlos Alvarez [Instituto de Investigaciones Fundamentales en Agriculturea Tropical (INIFAT), Santiago de las Vegas, La Habana (Cuba)]. E-mail: falvarez@cena.usp.br; Muraoka, Takashi; Trevizam, Anderson Ricardo [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Fertilidade do Solo; Franzini, Vinicius Ide [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Programa de Pos-graduacao em Solos e Nutricao de Plantas; Rocha, Alexandre Prado [Escola de Engenharia de Piracicaba, SP (Brazil)

    2006-01-15

    Eucalyptus plantation in Brazil is generally set on low fertility soils, therefore phosphorus (P) fertilization is mandatory and increases the cost of plantation operation. Using species that more efficiently uptake phosphorus from less soluble sources is an interesting option. However, little is known about eucalyptus regarding its ability of using less soluble forms of phosphorus. The use of P by eucalyptus (E. urophylla, E. grandis, and E. urophylla E. grandis) was studied in greenhouse using a loamy-textured, hipodystrophic Typic Haplustox from the Cerrado region, and 32P isotopic method. The P sources tested were triple superphosphate (TSP), phosphate rock (PR) and the triple superphosphate mixed with PR (TSP+PR). The effectiveness of P sources in terms of increasing dry matter yield was TSP = (TSP + PR) > PR, and the P uptake followed the order (TSP + PR) > TSP > PR for both species plus the hybrid. The increase in P uptake from PR due to TSP influence was 217.3% for E. urophylla, 235.7% for E. grandis, and 28.7% for E. urophylla E. grandis, indicating an enhancement effect of TSP on the effectiveness of PR. The hybrid E. urophylla E. grandis was the most efficient genotype on P soil use and E. grandis most exigent in P fertilizer. (author)

  8. The host plant Pinus pinaster exerts specific effects on phosphate efflux and polyphosphate metabolism of the ectomycorrhizal fungus Hebeloma cylindrosporum: a radiotracer, cytological staining and 31 P NMR spectroscopy study.

    Science.gov (United States)

    Torres-Aquino, Margarita; Becquer, Adeline; Le Guernevé, Christine; Louche, Julien; Amenc, Laurie K; Staunton, Siobhan; Quiquampoix, Hervé; Plassard, Claude

    2017-02-01

    Ectomycorrhizal (ECM) association can improve plant phosphorus (P) nutrition. Polyphosphates (polyP) synthesized in distant fungal cells after P uptake may contribute to P supply from the fungus to the host plant if they are hydrolyzed to phosphate in ECM roots then transferred to the host plant when required. In this study, we addressed this hypothesis for the ECM fungus Hebeloma cylindrosporum grown in vitro and incubated without plant or with host (Pinus pinaster) and non-host (Zea mays) plants, using an experimental system simulating the symbiotic interface. We used 32 P labelling to quantify P accumulation and P efflux and in vivo and in vitro nuclear magnetic resonance (NMR) spectroscopy and cytological staining to follow the fate of fungal polyP. Phosphate supply triggered a massive P accumulation as newly synthesized long-chain polyP in H. cylindrosporum if previously grown under P-deficient conditions. P efflux from H. cylindrosporum towards the roots was stimulated by both host and non-host plants. However, the host plant enhanced 32 P release compared with the non-host plant and specifically increased the proportion of short-chain polyP in the interacting mycelia. These results support the existence of specific host plant effects on fungal P metabolism able to provide P in the apoplast of ectomycorrhizal roots. © 2016 John Wiley & Sons Ltd.

  9. Radiotracer investigation of phosphoric acid and phosphatic fertilizers production process

    International Nuclear Information System (INIS)

    Ben Abdelouahed, H.; Reguigui, N.

    2011-01-01

    In the phosphoric acid production process, the time a particle spends inside the chemical reactor (residence time) is of paramount importance to process engineers. Residence time distribution (RTD) gives information on the efficiency of the chemical reactor, on the efficiency of the process, and also the availabilities of the reactive volume for the reaction (active volume vs. dead volume). Traditionally, chemical engineers used chemical tracer to determine the RTD. However, first disadvantage is that the chemical tracer could not allow an online diagnosis: the samples containing chemical tracer have to go to a lab for analysis, second disadvantage is that the chemical tracer is less sensitive than radioactive ones because of its adsorption onto strata or its retention in rocks. Consequently, chemical tracer results are not always precise and cannot convincingly explain the multiple flow-path model. Radioactive tracers are the only tracers capable of measuring the active RTD with high degree of precision and give information on the internal recirculation rate. In this work, we will describe the application of radiotracer method for RTD measurement in the phosphoric acid production process and give results and discussion of each case encountered. (author)

  10. Characterizing root activity of guava trees by radiotracer technique

    International Nuclear Information System (INIS)

    Purohit, A.G.; Mukherjee, S.K.

    1974-01-01

    The distribution pattern of root activity of 12-year-old trees of guava (Psidium guajava L.) was determined by radiotracer technique. 32 P soloution was injected into the soil at lateral distances of 120, 240 and 360 cm from the tree trunk at depths of 15,30,60 and 90 cm. The 32 P uptake by the tree was determined by leaf analysis. In the rainy season the root activity or 32 P uptake was greater near the soil surface and midway between the trunk and the drip-line. The root activity decreased with an increase in the depth and distance from trunk. These results compared well with the actual distribution of feeder roots as determined by the soil-auger method. In summer the roots near the surface become less active in 32 P absorption with a drcrease in surface soil moisture. A decrease in the root activity in the surface soil was accompanied by an increase in 32 P uptake from lower depths. (author)

  11. A dispersion model of transport media in radiotracer investigations on selected chemical installations

    International Nuclear Information System (INIS)

    Iller, E.

    1999-01-01

    Tracer investigations of media transport through chemical reactors play a significant role in the chemical technology. They provide the basis for the determination of some important process parameters, such as flow character of the transported medium, degree of utilisation of the reactor volume during chemical transitions of substrates or even indicate possible mechanisms of chemical reactions. Determination of the medium flow characteristics is closely connected with the mathematical description of the process - a mathematical model of transport. The method of assessment of radiotracers suitability for the investigation of distillation processes presented in this paper allows to determine, in a simple manner, the parameters of distillation characteristics of the radionuclides, the average distillation temperature, the range of distillation temperatures, a suitable radiochemical purity. These parameters precisely determine the behavior of tracers to be expected in a wide range of variable conditions of the distillation process. Applications of tracer tested in such a manner to the investigations of dynamics of media in the industrial rectification columns has resulted in obtaining a dependable evaluation of the performance of these columns in a wide range of changes of their operational parameters. Particular attention has been paid to dynamics of the liquid [phase on the column plate. A dispersion model of liquid flow with hold-up zones has been proposed for the description of the liquid phase transport in the plate - overall assembly.The model consists of a number of flow and stagnant zones, with mass transfer between them. Another example of practical application of results from radiotracer investigation is an analysis of of phase dynamics in the installations designed for the process of liquefaction of Polish coals by means of their catalytic hydrogenation. For the analysis of phase transport in a reaction vessel various mathematical models were applied with

  12. A reliability and utility study of the Care Dependency Scale

    NARCIS (Netherlands)

    Dijkstra, A.; Buist, G.; Moorer, P.; Dassen, T.

    2000-01-01

    The purpose of this study was to examine the reliability and utility of the Care Dependency Scale (CDS). This 15-item scale has been developed recently for assessing the care dependency of demented or menially handicapped inpatients. Data for this study were collected from 153 demented and 139

  13. Radiotracer studies of maneb residues in lettuce plants

    International Nuclear Information System (INIS)

    Sennaoui, Z.; Meguenni, H.; Bennaceur, M.

    1990-11-01

    Lettuce plants have received different treatments of 14C-maneb at variable time. A cleaning is made to determine the foliar surface residues. The analysis of CS2 showed relatively important amount especially for lots which have received 4 treatments (10,3ppm and 6,49ppm). The amounts found after combustion have showed increasing amounts, proportionally to the number of treatments. The analysis of ETU revealed a presence only for lots which have received several treatments (3 and 4). The analysis by TLC showed many metabolites. Two of them have been identified (ETU, EU). Interfoliar migration of 14C product occurred between treated leaves and untreated leaves of the same plant

  14. A radiotracer study of the sensitivity of bacteria to antibiotics

    International Nuclear Information System (INIS)

    Nagy, E.J.

    1975-01-01

    In the developed measuring apparatus the test bacterium E.coli was dissolved in 25 ml of the synthetic medium M9 (pH=7.0) and 2 μCi of D-glucose- 14 C (80 μg of glucose) was added to the solution. The test material was incubated at 37+-0.2 degC. In closed system the quantity of developing 14 CO 2 have been proportional to the multiplication rate of bacterium. The radioactive CO 2 have been absorbed in the box containing the liquid scintillation material. The absorption capacity of the toluene-base scintillation liquid was increased by adding diethanolamine (pH=10) and the multiplication was promoted by constant mixing. The sensitivity of the given bacterium to antibiotics like Penicillin G, Tetracyclin, Ampicillin, Polymycin B can be given in 60-120 min. (K.A.)

  15. Development of a fluidized-bed method for on-line evaluation of radiotracers in vitro; Entwicklung einer Fliessbettechnik zur Bewertung von Radiopharmaka an Zellkulturen

    Energy Technology Data Exchange (ETDEWEB)

    Noll, T.

    1999-05-01

    This study presents the development of a continuously operating fluidized-bed bioreactor for on-line evaluation of radiotracers in vitro, which combines tissue-like three-dimensional cell cultivation in open porous microcarriers with a technique for on-line radioactivity detection. The long time stability of steady-state permits a large number of experiments using the same culture. All relevant parameters (O{sub 2}, pH, T, etc.) can be adjusted according to the experimental requirements. The flux of the circulating medium can be adapted to the blood flow of the corresponding organism, while the input function of the radiotracer is freely adjustable for simulation of in vivo conditions. Sampling and examination of the immobilized cells care possible at any time. Using this system, the kinetics of 2-[{sup 18}F]fluoro-2-deoxyglucose (FDG) in human glioma cells (86HG39) were studied and it was shown that the dependence of the lumped constant (LC) for FDG on the medium glucose concentration is similar to that obtained in the rat brain. For normoglycemic concentrations the LC was determined to be in the range of 0.7, while in hypoglycemia it increased progressively up to a value of 1.22 at a glucose concentration of 3 mM. The rate constants in the three compartment model were found to be similar to those obtained in vivo using PET; indicating the validity of the system for tracer evaluation. Furthermore the kinetics of both diastereomeric forms of 4-[{sup 18}F]fluoro-proline was investigated and found that both diastereomeres were not metabolized and reached an identical intracellular steady state concentration. The trans-form was transported three times faster than the cis-diastereomere, indicated by the rate constants. (orig.) [German] Diese Arbeit beschreibt die Entwicklung eines kontinuierlich betriebenen Wirbelschichtreaktors zur on-line Bewertung von Radiotracern an Zellkulturen. Der Bioreaktor kombiniert eine gewebeaehnliche, dreidimensionale Zellkultivierung in

  16. Extraction of the mixture 99mTcO4- tributilfosfato- 30% 16% trioctylamine in cyclohexane evaluation of radiotracer obtained

    International Nuclear Information System (INIS)

    Ortega Pijeira, Martha Sahyli; Dominguez Catasus, Judith; Martinez Baez, Ernesto; Borroto Portela, Jorge

    2014-01-01

    Tracer technology plays an important role in industry development and has been widely used to optimize process, solve problems and improve product quality. In the last years Cuban scientific have studied the 99m TcO 4 - , eluted from 99 Mo/ 99m Tc generator, extraction with the mixture 30 % tributylphosphate -16 % trioctylamine in cyclohexane, in order to get an organic radiotracer. In this paper, the influence on 99m TcO 4 - extraction of stirring speed, contact time and NaCl concentration were studied. The extractant's role was also studied and, the tracer's homogeneity in diesel, special gasoline and Venezuelan oils was evaluated to normal pressure and temperature. The obtained outcomes showed that the NaCl concentration only influences on the extraction process when it is less than 0.17 %. Furthermore, the employed mixture's synergism was noticed and, could be conclude that, the obtained tracer is a physical radiotracer for the used industrial supports to 95 % trustworthy

  17. A built-in radiotracer (24Na) for measuring circulation catalyst rates

    International Nuclear Information System (INIS)

    Domondon, D.B; Berbano, M.C.

    1975-01-01

    A local petroleum refinery intended to calibrate its catalyst flow measuring instrument (propeller blade) using the radioactive tracer technique (RTT). For this purpose, a method of incorporating a suitable radiotracer in commercial catalyst beads had to be found. Two methods of labelling are described. One method involved the incorporation of the radiotracer in a gel of the same composition as the commercial catalyst and subsequent conversion of the gel into a from like that of the commercial catalyst beads. Another method utilized the strong adsorptive properties of the commercial catalyst beads for the chosen isotopes, e.g., 144 Cs, 46 Sc. To effect quantitative adsorption, commercial catalyst beads were simply stirred in a slightly acidic (pH4) chloride solution of the radiotracers for some time. The radiotracers were found to distribute almost uniformly over the entire catalyst surface and no evidence of volatilization of the isotopes from the catalyst surface under condition of use in commercial units was observed. Another probable method was suggested by the Research and Development Division, Philippine Atomic Energy Commission. Aluminium is a major component of the ceramic catalyst beads and sodium is present as impurity. Hence, a radiotracer ( 24 Na) can be formed in the beads by the reaction 23 Na (n,gamma) 24 Na, 27 Al (n,alpha) 24 Na. This possible method of simply irradiating the commercial catalyst beads in the reactor thereby inducing the radiotracer. 24 Na in situ fulfils all the criteria for the selection of an appropriate radiotracer. The method is very simple but reliable

  18. Physical and psychological nicotine dependence in Greeks: an epidemiological study.

    Science.gov (United States)

    Margaritis, Vasileios; Mamai-Homata, Eleni

    2010-01-01

    Smoking is the most widespread addictive behaviour in the world, as it causes physical and psychological dependence on nicotine. The objective of the present study was to discern the prevalence and the relative risks of nicotine dependence of adult people in Athens, Greece, as this country holds first place in cigarette consumption in the European Union. A random sample of 202 current smokers (82 men and 120 women) was drawn from residents aged v 18 years in Athens, the capital of Greece. A questionnaire on the physical (Fagerstrom Test of Nicotine Dependence) and psychological (American Psychiatric Association's diagnostic criteria of nicotine abuse) nicotine dependence was used. According to the results of the present study, 12.4% of the sample reported null physical nicotine dependence, and 31.7% had low, 25.7% had moderate and 30.2% had high nicotine dependence. Multiple logistic regression analysis revealed that younger people (aged 18 to 24 and 25 to 34, odds ratio [OR] = 0.047, P physical dependence. Women tended to be systematically less dependent than men (25% and 37.8% high dependence, respectively). Furthermore, 75.7% of the sample had psychological nicotine dependence. Binary logistic regression analysis and chi-square test revealed that younger people (18- to 24-year-olds, OR = 0.081, P dependence. In addition, women showed a higher percentage of withdrawal symptoms compared with men (80% and 68%, respectively). The results of the present study provided compelling evidence that physical and, in particular, psychological nicotine dependence of adult people in Athens, Greece, was significant, and this calls for a course of action that should be taken by public health policy-makers to reduce smoke consumption.

  19. Comparison of Amino Acid Positron Emission Tomographic Radiotracers for Molecular Imaging of Primary and Metastatic Brain Tumors

    Directory of Open Access Journals (Sweden)

    Csaba Juhász

    2014-08-01

    Full Text Available Positron emission tomography (PET is an imaging technology that can detect and characterize tumors based on their molecular and biochemical properties, such as altered glucose, nucleoside, or amino acid metabolism. PET plays a significant role in the diagnosis, prognostication, and treatment of various cancers, including brain tumors. In this article, we compare uptake mechanisms and the clinical performance of the amino acid PET radiotracers (L-[methyl-11C]methionine [MET], 18F-fluoroethyl-tyrosine [FET], 18F-fluoro-L- dihydroxy-phenylalanine [FDOPA], and 11C-alpha-methyl-L-tryptophan [AMT] most commonly used for brain tumor imaging. First, we discuss and compare the mechanisms of tumoral transport and accumulation, the basis of differential performance of these radioligands in clinical studies. Then we summarize studies that provided direct comparisons among these amino acid tracers and to clinically used 2-deoxy-2[18F]fluoro-D-glucose [FDG] PET imaging. We also discuss how tracer kinetic analysis can enhance the clinical information obtained from amino acid PET images. We discuss both similarities and differences in potential clinical value for each radioligand. This comparative review can guide which radiotracer to favor in future clinical trials aimed at defining the role of these molecular imaging modalities in the clinical management of brain tumor patients.

  20. Online gaming dependency: a preliminary study in China.

    Science.gov (United States)

    Peng, Wei; Liu, Ming

    2010-06-01

    Based on theories and previous studies on problematic Internet use, we propose a model to better understand the contributors to and consequences of online gaming dependency. A preliminary study was conducted through a survey of online gamers in China. The results of path analysis found that maladaptive cognitions, shyness, and depression are positively related to online gaming dependency. Online gaming dependency was also positively related to different types of negative life outcomes. The findings of this study have implications for the prevention and treatment of addictive online gaming.

  1. The Study of early maladaptive Schemas in Men Dependent on Drugs and those Not Dependent

    Directory of Open Access Journals (Sweden)

    MR Firoozi

    2015-11-01

    Full Text Available Introduction and Objectives of the Study Dependence on drugs is a prevalent problem throughout the world, in general and in Iran, in particular. Such a phenomenon is associated with numerous negative consequences. Given the changes in the consumption patterns in different countries, especially in Iran, and the abuse of drugs, identifying the factors which may pave the way for drug abuse is absolutely essential, which can be taken into account in setting the objectives of therapy programs. Cognizant of this, the present study has sought to study early maladaptive schemas in men dependent on drugs and those that are not. Materials and Method: The research design adopted in the present study was causal-comparative. The populaiton of interest was all the men dependent on drugs in the city of Yasouj, who had presented to recovery centers affiliated to welfare organization and Yasouj University of Medical Sciences in the year 2014 and were undergoing treatment. Using multi-stage cluster sampling, initially out of 23 centers for recovery programs, four centers were randomly chosen. Following that, out of each center, 20 and in total, 80 clients were chosen as the sample through convenience sampling. In addition, 80 men not dependent on drugs were chosen through matching with the sample dependent on drugs in terms of age, gender and locality. For the purpsoe of measuing early maladaptive schemas, we made use of the short version of Young’s early maladaptive Schemas Questionnaire. In order to determine the prevalent schemas in men dependent on drugs and those not dependent and the difference between the two groups, use was made of independent-sample t-test and effect size (d. Findings: The findings suggest that mean values of those dependent on drugs in all the schemas in quesiton were significantly higher than those of men not dependent. Although the difference in effect size of all schemas fell in the domain of the large effect, the largest

  2. Estimative of dilution factor for radioactive liquid effluents employing the H-3 and Cs-137 radiotracers present as pollutant

    International Nuclear Information System (INIS)

    Nisti, Marcelo Bessa; Santos, Adir Janete Godoy dos

    2011-01-01

    It was estimated the dilution factor for liquid effluents at the discharge points of the IPEN, Sao Paulo, Brazil, employing as radiotracers the radioisotope routinely liberated for the sewage of 'Cidade Universitaria Armando de Salles Oliveira' - CUASO 3 H and 137 Cs, not generating either monetary or environmental cost associated to the estimation. The 137 Cs was determined by gamma spectrometry and the 3 H was determined liquid phase scintillation. The results showed that the dilution factor varied according to the employed radiotracer in a crescent order of 3 H and 137 Cs according to the characteristics of each element. The average of dilution factors obtained at the first and second liberation day were 4.3 and 7.4 respectively for the 3 H and 6.2 and 13.9 for the 137 Cs. The ratio of dilution factors of calculated 3 H and 137 Cs were coherent with the ratio verified at the twelve hydrometers distributed by the IPEN campus. The dilution factors were estimated in operational and laboratory study, in a single controlled discharge of the TR1 tank

  3. Marking an antibacterial agent by Tc-99m: development of a radiotracer for the detection of infectious foci

    International Nuclear Information System (INIS)

    Ghali, Wafa

    2009-01-01

    Nuclear imaging is a non-invasive exploration technique, used for rapid diagnostic of infections disease thus, for osteoarticular infection scintigraphic techniques were proposed to ameliorate the diagnostic sensibility and the use of radiolabeled antibiotics as imaging agents of infectious loci become more ana more recognized. In this work, a new sulfanilamide derivative, The N-sulfanilamide-ferrocene-carboxamide (SFC) was chemically synthesized then labeled with technetium-99m, with a radiochemical yield, >87 pour cent. In vitro investigations were conducted, and the label's stability in serum was found as more than 20 hours at 37 degree. then uptake of labeled compound was determined by counting radioactivity in bacterial pellet of about 69 pour cent for the E.coli strain and 61,9 pour cent for S. Aureus strain, was estimated. A biodistribution study of technetium-99m - SFC allowed the comprehension of radiotracer kinetics and ways of biotransformation. And a significantly higher (p<0.05) accumulation of technetium-99m - SFC was seen at sites of S. aureus-infected animals (T/NT ratio, 2.88±0.5) compared with others radiotracers. So with all those founded results could establish that SFC may be a bacterial infection-seeking agent in staphylococcus aureus-induced infections.

  4. In vitro characterization of [18F]-florbetaben, an Aβ imaging radiotracer

    International Nuclear Information System (INIS)

    Fodero-Tavoletti, Michelle T.; Brockschnieder, Damian; Villemagne, Victor L.; Martin, Lucas; Connor, Andrea R.; Thiele, Andrea; Berndt, Mathias; McLean, Catriona A.; Krause, Sabine; Rowe, Christopher C.; Masters, Colin L.; Dinkelborg, Ludger; Dyrks, Thomas; Cappai, Roberto

    2012-01-01

    Purpose: Amyloid-β (Aβ) plaques are a major pathological hallmark of Alzheimer's disease (AD). The noninvasive detection of Aβ plaques may increase the accuracy of clinical diagnosis as well as monitor therapeutic interventions. While [ 11 C]-PiB is the most widely used Aβ positron emission tomography (PET) radiotracer, due to the short half-life of 11 C (20 min), its application is limited to centers with an on-site cyclotron and 11 C radiochemistry expertise. Therefore, novel [ 18 F] (half-life 110 min)-labeled Aβ PET tracers have been developed. We have demonstrated that [ 18 F]-florbetaben-PET can differentiate individuals diagnosed with AD from healthy elderly, Parkinson's disease and frontotemporal lobe dementia (FTLD-tau) patients. While [ 18 F]-florbetaben-PET retention matched the reported postmortem distribution of Aβ plaques, the nature of [ 18 F]-florbetaben binding to other pathological lesions comprising misfolded proteins needs further assessment. The objective of this study was to determine whether Florbetaben selectively binds to Aβ plaques in postmortem tissue specimens containing mixed pathological hallmarks (i.e., tau and α-synuclein aggregates). Method: Human AD, FTLD-tau and dementia with Lewy bodies (DLB) brain sections were analyzed by [ 18 F]-florbetaben autoradiography and [ 3 H]-florbetaben high-resolution emulsion autoradiography and [ 19 F]-florbetaben fluorescence microscopy. Results: Both autoradiographical analyses demonstrated that Florbetaben exclusively bound Aβ plaques in AD brain sections at low nanomolar concentrations. Furthermore, at concentrations thousand-folds higher than those during a PET scan, [ 19 F]-florbetaben did not bind to α-synuclein or tau aggregates in DLB and FTLD-tau brain sections, respectively. Detection of [ 19 F]-florbetaben staining by fluorescence microscopy in several AD brain regions demonstrated that Florbetaben identified Aβ plaques in all brain regions examined. Conclusion: This study

  5. Study of Cu-Al-Zn alloys hardness temperature dependence

    International Nuclear Information System (INIS)

    Kurmanova, D.T.; Skakov, M.K.; Melikhov, V.D.

    2001-01-01

    In the paper the results of studies for the Cu-Al-Zn ternary alloys hardness temperature dependence are presented. The method of 'hot hardness' has been used during study of the solid state phase transformations and under determination of the hot stability boundaries. Due to the samples brittleness a hardness temperature dependence definition is possible only from 350-400 deg. C. Sensitivity of the 'hot hardness' method is decreasing within high plasticity range, so the measurements have been carried out only up to 700-800 deg. C. It is shown, that the alloys hardness dependence character from temperature is close to exponential one within the certain structure modification existence domain

  6. Analysis of dependent failures in the ORNL precursor study

    International Nuclear Information System (INIS)

    Ballard, G.M.

    1985-01-01

    The study of dependent failures (or common cause/mode failures) in the safety assessment of potentially hazardous plant is one of the significant areas of uncertainty in performing probabilistic safety studies. One major reason for this uncertainty is that data on dependent failures is apparently not readily available in sufficient quantity to assist in the development and validation of models. The incident reports that were compiled for the ORNL study on Precursors to Severe Core Damage Accidents (NUREG/CR-2497) provide an opportunity to look at the importance of dependent failures in the most significant incidents of recent reactor operations, to look at the success of probabilistic risk assessment (PRA) methods in accounting for the contribution of dependent failures, and to look at the dependent failure incidents with the aim of identifying the most significant problem areas. In this paper an analysis has been made of the incidents compiled in NUREG/CR-2497 and events involving multiple failures which were not independent have been identified. From this analysis it is clear that dependent failures are a very significant contributor to the precursor incidents. The method of enumeration of accident frequency used in NUREG-2497 can be shown to take account of dependent failures and this may be a significant factor contributing to the apparent difference between the precursor accident frequency and typical PRA frequencies

  7. Application of Radiotracer Technology on Solving the Unsolved Leak in Lift Pit

    International Nuclear Information System (INIS)

    Mohd Fitri Abdul Rahman; Jaafar Abdullah; Hearie Hassan

    2016-01-01

    Radiotracers have been used in many fields to optimize processes, solve problems, improve product quality, save energy and reduce pollution. The radiotracer technology is a proven reliable technique and recognized by many sectors such as medical, industrial and environmental. In this work, an unsolved leak problem was present in lift pit within a building in Malaysia. Many techniques have applied such as dye techniques, chemical analyses and engineering plaster to overcome the problem. Unfortunately, none of the techniques solve the problem. Radiotracer was used to find the unidentified source of leak. Basically, Technetium (Tc-99m) has been injected to the several injection points and flow of the tracer was monitored with radiation detectors that have been placed at various locations. The results were successful and pinpoint the problems. (author)

  8. Indepth diagnosis of a secondary clarifier by the application of radiotracer technique and numerical modeling.

    Science.gov (United States)

    Kim, H S; Shin, M S; Jang, D S; Jung, S H

    2006-01-01

    To make an indepth diagnosis of a full-scale rectangular secondary clarifier, an experimental and numerical study has been performed in a wastewater treatment facility. Calculation results by the numerical model with the adoption of the SIMPLE algorithm of Patankar are validated with radiotracer experiments. Emphasis is given to the prediction of residence time distribution (RTD) curves. The predicted RTD profiles are in good agreement with the experimental RTD curves at the upstream and center sections except for the withdrawal zone of the complex effluent weir structure. The simulation results predict successfully the well-known flow characteristics of each stage such as the waterfall phenomenon at the front of the clarifier, the bottom density current and the surface return flow in the settling zone, and the upward flow in the exit zone. The detailed effects of density current are thoroughly investigated in terms of high SS loading and temperature difference between influent and ambient fluid. The program developed in this study shows the high potential to assist in the design and determination of optimal operating conditions to improve effluent quality in a full-scale secondary clarifier.

  9. Models and methods for derivation of in vivo neuroreceptor parameters with PET and SPECT reversible radiotracers

    International Nuclear Information System (INIS)

    Slifstein, Mark; Laruelle, Marc

    2001-01-01

    The science of quantitative analysis of PET and SPECT neuroreceptor imaging studies has grown considerably over the past decade. A number of methods have been proposed in which receptor parameter estimation results from fitting data to a model of the underlying kinetics of ligand uptake in the brain. These approaches have come to be collectively known as model-based methods and several have received widespread use. Here, we briefly review the most frequently used methods and examine their strengths and weaknesses. Kinetic modeling is the most direct implementation of the compartment models, but with some tracers accurate input function measurement and good compartment configuration identification can be difficult to obtain. Other methods were designed to overcome some particular vulnerability to error of classical kinetic modeling, but introduced new vulnerabilities in the process. Reference region methods obviate the need for arterial plasma measurement, but are not as robust to violations of the underlying modeling assumptions as methods using the arterial input function. Graphical methods give estimates of V T without the requirement of compartment model specification, but provide a biased estimator in the presence of statistical noise. True equilibrium methods are quite robust, but their use is limited to experiments with tracers that are suitable for constant infusion. In conclusion, there is no universally 'best' method that is applicable to all neuroreceptor imaging studies, and carefully evaluation of model-based methods is required for each radiotracer

  10. Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

    Science.gov (United States)

    Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

  11. Distributed microprocessor automation network for synthesizing radiotracers used in positron emission tomography

    International Nuclear Information System (INIS)

    Russell, J.A.G.; Alexoff, D.L.; Wolf, A.P.

    1984-01-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. 20 refs. (DT)

  12. Synthesis and marking with technetium and rhenium of a new radiotracer from para-toluidine

    International Nuclear Information System (INIS)

    Laouini, Emna

    2011-01-01

    The development of nuclear medicine is based on the research of new radiotracers especially those which target the neuro degenerative diseases. In fact, the precocious diagnostic of these diseases using the radiopharmaceuticals is the only mean to defeat it. The biodistribution of a new cytectrene derivative from para-toluidine, having a lipophilic character and a low molecular weight, showed a new radiotracer which is able to clear the blood brain barrier and characterised with prolonged brain retention. The features of this complex contribute to make it a radiopharmaceutical to diagnostic aim in clinical use.

  13. Industrial applications of radiotracer and sealed source technology promoted by IAEA

    International Nuclear Information System (INIS)

    Joon-Ha Jin; Thereska, J.

    2004-01-01

    Great technical and economical benefits can be obtained by applying radioisotope technologies to various industries. The International Atomic Energy Agency (IAEA) has contributed to the development of radiotracer and sealed source technology as applied to industry and environment through coordinated research projects (CRPs). The mature and competitive techniques have been transferred and implemented to developing countries through the Agency's technical co-operation (TC) projects. The paper presents the main achievements in radiotracer and sealed source technology promoted by IAEA as well as the perspective of the technology transfer to developing countries. (author)

  14. Viability and proliferation potential of adipose-derived stem cells following labeling with a positron-emitting radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Elhami, Esmat [University of Manitoba, Department of Radiology, Winnipeg (Canada); University of Winnipeg, Department of Physics, Winnipeg, MB (Canada); Goertzen, Andrew L.; Mzengeza, Shadreck [University of Manitoba, Department of Radiology, Winnipeg (Canada); Xiang, Bo; Deng, Jixian; Stillwell, Chris; Tian, Ganghong [National Research Council Canada, Cardiac Studies Group, Institute for Biodiagnostics, Winnipeg (Canada); Arora, Rakesh C.; Freed, Darren [St. Boniface General Hospital, Cardiac Science Program, Winnipeg (Canada)

    2011-07-15

    Adipose-derived stem cells (ASCs) have promising potential in regenerative medicine and cell therapy. Our objective is to examine the biological function of the labeled stem cells following labeling with a readily available positron emission tomography (PET) tracer, {sup 18}F-fluoro-2-deoxy-D-glucose (FDG). In this work we characterize labeling efficiency through assessment of FDG uptake and retention by the ASCs and the effect of FDG on cell viability, proliferation, transdifferentiation, and cell function in vitro using rat ASCs. Samples of 10{sup 5} ASCs (from visceral fat tissue) were labeled with concentrations of FDG (1-55 Bq/cell) in 0.75 ml culture medium. Label uptake and retention, as a function of labeling time, FDG concentration, and efflux period were measured to determine optimum cell labeling conditions. Cell viability, proliferation, DNA structure damage, cell differentiation, and other cell functions were examined. Non-labeled ASC samples were used as a control for all experimental groups. Labeled ASCs were injected via tail vein in several healthy rats and initial cell biodistribution was assessed. Our results showed that FDG uptake and retention by the stem cells did not depend on FDG concentration but on labeling and efflux periods and glucose content of the labeling and efflux media. Cell viability, transdifferentiation, and cell function were not greatly affected. DNA damage due to FDG radioactivity was acute, but reversible; cells managed to repair the damage and continue with cell cycles. Over all, FDG (up to 25 Bq/cell) did not impose severe cytotoxicity in rat ASCs. Initial biodistribution of the FDG-labeled ASCs was 80% + retention in the lungs. In the delayed whole-body images (2-3 h postinjection) there was some activity distribution resembling typical FDG uptake patterns. For in vivo cell tracking studies with PET tracers, the parameter of interest is the amount of radiotracer that is present in the cells being labeled and consequent

  15. Screening crops for efficient phosphorus acquisition in a low phosphorus soil using radiotracer technique

    International Nuclear Information System (INIS)

    Meena, S.; Malarvizhi, P.; Rajeswari, R.

    2017-01-01

    Deficiency of phosphorus (P) is the major limitation to agricultural production. Identification of cultivars with greater capacity to grow in soils having low P availability (phosphorus efficiency) will help in P management in a sustainable way. Green house experiment with maize (CO 6) and cotton (MCU 13) as test crops with four levels of phosphorus (0, 3.75, 7.50 and 15 mg P kg -1 soil) was conducted in a P deficient soil (7.2 kg ha -1 ) to study the phosphorus acquisition characteristics and to select efficient crop using 32 P radiotracer technique. Carrier free 32 P obtained as orthophosphoric acid in dilute hydrochloric acid medium from the Board of Radiation and Isotope Technology, Mumbai was used for labeling the soil @ 3200 kBq pot -1 . After 60 days the crops were harvested and the radioactivity was measured in the plant samples using Liquid scintillation counter (PerkinElmer - Tricarb 2810 TR). Different values of specific radioactivity and Isotopically Exchangeable Phosphorus for maize and cotton indicated that chemically different pools of soil P were utilized and maize accessing a larger pool than cotton. Maize having recorded high Phosphorus Use Efficiency, Phosphorus Efficiency and low Phosphorus Stress Factor values, it is a better choice for P deficient soils. Higher Phosphorus Acquisition Efficiency of maize (59 %) than cotton (48%) can be related to the ability of maize to take up P from insoluble inorganic P forms. (author)

  16. Design of a serotonin 4 receptor radiotracer with decreased lipophilicity for single photon emission computed tomography.

    Science.gov (United States)

    Fresneau, Nathalie; Dumas, Noé; Tournier, Benjamin B; Fossey, Christine; Ballandonne, Céline; Lesnard, Aurélien; Millet, Philippe; Charnay, Yves; Cailly, Thomas; Bouillon, Jean-Philippe; Fabis, Frédéric

    2015-04-13

    With the aim to develop a suitable radiotracer for the brain imaging of the serotonin 4 receptor subtype (5-HT4R) using single photon emission computed tomography (SPECT), we synthesized and evaluated a library of di- and triazaphenanthridines with lipophilicity values which were in the range expected to favour brain penetration, and which demonstrated specific binding to the target of interest. Adding additional nitrogen atoms to previously described phenanthridine ligands exhibiting a high unspecific binding, we were able to design a radioiodinated compound [(125)I]14. This compound exhibited a binding affinity value of 0.094 nM toward human 5-HT4R and a high selectivity over other serotonin receptor subtypes (5-HTR). In vivo SPECT imaging studies and competition experiments demonstrated that the decreased lipophilicity (in comparison with our previously reported compounds 4 and 5) allowed a more specific labelling of the 5-HT4R brain-containing regions. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. Estimation of portal-systemic shunting by rectal infusion of radiotracer

    International Nuclear Information System (INIS)

    Piga, M.; Satta, L.; Loviselli, A.; Taglieri, G.; Balestrieri, A.; Cossu, L.; Madeddu, G.

    1986-01-01

    Spontaneous portal anastomoses develop as a consequence of an increased portal pressure gradient. This report presents a new method for evaluating portal-systemic shunts by rectal infusion of a radiotracer. Five patients affected by primary haemorrhoidal syndrome, 15 with chronic liver disease (CLD), 40 with liver cirrhosis (C), 4 with surgical portal anastomoses (PCA) and 9 healty controls were studied. All patients underwent oesophagogastroscopy and 12 wedged hepatic vein pressure determination. After rectal infusion of 99m TcO 4 - by a microclister, scintigraphic images were recorded at the acquisition rate of 1 per 20 seconds for 10 minutes. Two regions of interest, corresponding to the heart (H) and the liver (L), were traced on the display images and the H/L activity ratio a the 4th minute was determined. In controls, the mean H/L ratio was 0.61±0.09, in CLD 0.76±0.18, in C 1.79±0.31 and in PCA 2.00±0.14. Differences between control H/L ratios and those of the groups of patients were statistically significant (p<0.025, 0.0005 and 0.005, respectively). Significant correlations between H/L ratio and wedged hepatic vein pressure (r=-0.61; p<0.001) were found. This rapid, noninvasive procedure, well tolerated by patients, seems to be suitable for the evaluation of portal haemodynamics and for the prediction of portal pressure values

  18. Phosphorus use efficiency of maize: an investigation using radiotracer phosphorus (32P)

    International Nuclear Information System (INIS)

    Meena, S.

    2017-01-01

    A better understanding on the nutrient uptake and utilization by plants is essential for developing better nutrient efficient cultivars suited for optimal production. Precise information on the PUE of crops and P dynamics can be obtained with the help of radiotracer technique. To study the phosphorus acquisition and phosphorus use efficiency of added sources in maize using 32 P, a pot culture experiment was conducted in a medium P soil (21.26 kg ha -1 ). The treatments were P as Single Superphosphate, Enriched FYM with Single Superphosphate (EFYM), DAP, Nutriseed pack (SSP), Nutriseed pack (DAP). The above treatments were applied along with phosphobacteria. Totally there were ten treatments replicated four times. Phosphorus sources were tagged with 32 P (obtained as 32 P in orthophosphoric medium from the Board of Radiation and Isotope Technology) and applied as per the treatments. Radioactive 32 P in the grain and stover sample was determined using Liquid Scintillation Counter (Perkin Elmer Tricarb 2810 R). Using the data, per cent phosphorus derived from fertilizer (%Pdff), per cent phosphorus derived from soil (%Pdfs), Phosphorus Use Efficiency (PUE) and A value were determined. Application of Phosphorus (SSP, DAP, enriched FYM with SSP, Nutriseed pack (SSP) and Nutriseed pack (DAP)) along with PB increased the per cent phosphorus derived from fertilizer (% Pdff), P uptake from fertilizer and PUE. The highest PUE of 25.38 was recorded in the treatment where enriched FYM with SSP was applied along with PB. (author)

  19. Determination of oil reservoir radiotracer (S{sup 14}CN{sup -}) in a single step using a plastic scintillator extractive resin

    Energy Technology Data Exchange (ETDEWEB)

    Bagan, H.; Tarancon, A. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Stavsetra, L. [Department for Reservoir and Exploration Technology, Institute for Energy Technology (IFE), Instituttveien 18, N-2027 Kjeller (Norway); Rauret, G. [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Garcia, J.F., E-mail: jfgarcia@ub.edu [Departament de Quimica Analitica, Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain)

    2012-07-29

    Highlights: Black-Right-Pointing-Pointer A new procedure for S{sup 14}CN{sup -} radiotracer determination using PS resin was established. Black-Right-Pointing-Pointer The minimum detectable activity for a 100 mL sample is 0.08 Bq L{sup -1}. Black-Right-Pointing-Pointer The minimum quantifiable activity for a 100 mL sample is 0.31 Bq L{sup -1}. Black-Right-Pointing-Pointer PS resin is capable to quantify S{sup 14}CN{sup -} radiotracer samples with errors lower than 5%. Black-Right-Pointing-Pointer PS resin is also capable to quantify complex matrices obtained from oil reservoirs. - Abstract: The analysis of radiotracers is important in the study of oil reservoir dynamics. One of the most widely used radiotracer is S{sup 14}CN{sup -}. Prior to activity measurements by Liquid Scintillation (LS), routine determinations require the pretreatment steps of purification and concentration of the samples using anion exchange columns. The final elution media produces samples with high salt concentration that may lead to problems with phase separation during the LS measurement. Plastic Scintillation (PS) is an alternative technique that provides a solid surface that can be used as a platform for the immobilisation of selective extractants to obtain a PS resin. The proposed procedure unifies chemical separation and sample measurement preparation in a single step, serving to reduce the number of reagents needed and manpower required for the analysis while also avoiding mixed waste production by LS. The objective of this study is to develop a PS resin for the determination of {sup 14}C-labelled thiocyanate radiotracer in water samples. For this purpose, the immobilisation procedure was optimised, including optimisation of the proportion of PS microspheres:extractant and the use of a control blank to monitor the PS resin immobilisation process. The breakthrough volume was studied and the detection and quantification limits for 100 mL of sample were determined to be 0.08 Bq L{sup -1

  20. Evaluation of bone-seeking novel radiotracer {sup 68}Ga-NO2AP-Bisphosphonate for the detection of skeletal metastases in carcinoma breast

    Energy Technology Data Exchange (ETDEWEB)

    Passah, Averilicia; Tripathi, Madhavi; Ballal, Sanjana; Yadav, Madhav Prasad; Kumar, Rajeev; Chakraborty, Partha Sarathi; Bal, Chandrasekhar [All India Institute of Medical Sciences, Department of Nuclear Medicine, Ansari Nagar, New Delhi (India); Roesch, Frank; Meckel, Marian [Johannes-Gutenberg-University, Nuclear Chemistry, Mainz (Germany)

    2017-01-15

    The successful labelling of bisphosphonates (BP) with {sup 68}Ga using macrocyclic chelators such as the based triazacyclononane (NO2AP) is a step forward in the in-house availability of a novel bone-seeking PET radiopharmaceutical with dual advantage of PET/CT imaging and generator production. In this study, we compared the novel generator-based skeletal radiotracer {sup 68}Ga-1,4,7-triazacyclonone-1,4-diacetic acid ({sup 68}Ga-NO2AP-BP) with sodium fluoride ({sup 18}F-NaF) for the detection of skeletal metastases in breast cancer patients. In addition, dosimetric analysis of {sup 68}Ga-NO2AP-BP was performed in a subset of patients. This was a prospective study of histopathologically proven cases of breast cancer patients who were referred for bone scintigraphy and underwent positron emission tomography/computed tomography (PET/CT) with {sup 18}F-NaF and {sup 68}Ga-NO2AP-BP within a week in random order. The scans of each patient were compared both qualitatively for image quality and quantitatively for number of lesions and SUVmax of lesions. Dosimetric analysis was performed in five patients. Their PET/CT scans were acquired at multiple time points and urine and blood samples were collected. Dosimetric calculations were performed using OLINDA/EXM 1.1 software. Statistical analysis was done using Stata 13 (StataCorp) software package. An agreement analysis regarding number of lesions detected with the two skeletal radiotracers was carried out. The image quality of {sup 68}Ga-NO2AP-BP PET/CT scans were comparable to that of {sup 18}F-NaF. There was no statistically significant difference in the SUVmax of lesions, normal bone and lesion to background ratio between the two skeletal radiotracers. There was good agreement in the number of lesions detected by both skeletal radiotracers. The mean whole body effective dose for {sup 68}Ga-NO2AP-BP was 0.00583 mSv/MBq and the effective dose equivalent was 0.0086 mSv/MBq. The excellent lesion detection agreement between

  1. Preparation and bioevaluation of 99Tcm-HYNIC-Annexin B1 as a novel radiotracer for apoptosis detection

    International Nuclear Information System (INIS)

    Luo Quanyong; Luo Qiong; Lu Hankui; Zhu Ruisen; Wang Fang; Zhang Yi; Sun Shuhan; Zhang Zhiyong; Liu Xingfeng

    2008-01-01

    Objective: Annexin B1, a novel Ca 2+ -dependent phosphatidylserine (PS)-binding protein, has been shown to have a high affinity for PS exposed on the surface of apoptotic cells or activated platelets. The aim of this study was to develop and bioevaluate an Annexin B1 based PS-targeting radiotracer labeled with 99 Tc m . Methods: Annexin B1 was indirectly labeled with 99 Tc m using hydrazinonicotinamide (HYNIC) as a bifunctional chelator agent. Binding assay with human activated platelets was used to evaluate the biological activity of 99 Tc m -HYNIC-Annexin B1 in vitro. The potential of 99 Tc m -HYNIC-Annexin B1 to detect apoptosis in vivo was evaluated in mice models with dexamethasone-inducecd thymus apoptosis and anti-Fas antibody induced liver apoptosis. The paired t-test was used to analyse the data. Results: The labeling procedure yielded a compound with radiochemical purity higher than 96% and good in vitro stability. Plate- lets binding assay indicated that 99 Tc m -HYNIC-Annexin B1 retained their PS binding activity in vitro. The percentage activity of injection dose per gram of tissue (% ID/g) of mouse thymus showed a 3.50-fold increase at 18 h after administration of dexamethasone compared with control mice (t=5.234, P 99 Tc m -HYNIC-Annexin B1 in the liver of anti-Fas antibody treated mice. The %ID/g of apoptotic murine liver showed a 2.02-fo1d increase at 2 h after the administration of anti-Fas antibody compared with control mice (t=6.178, P 99 Tc m -HYNIC-Annexin B1 can be prepared with high radiochemical purity and in vitro stability. These da- ta also suggest that 99 Tc m -HYNIC-Annexin B1 retains its in vitro and in vivo biological activities. It may therefore be useful as a novel radioligand for the noninvasive imaging of PS externalization associated with apoptosis. (authors)

  2. Study of excitation energy dependence of nuclear level density parameter

    International Nuclear Information System (INIS)

    Mohanto, G.; Nayak, B.K.; Saxena, A.

    2016-01-01

    In the present study, we have populated CN by fusion reaction and excitation energy of the intermediate nuclei is determined after first chance α-emission to investigate excitation energy dependence of the NLD parameter. Evaporated neutron spectra were measured following alpha evaporation for obtaining NLD parameter for the reaction 11 B + 197 Au, populating CN 208 Po. This CN after evaporating an α-particle populates intermediate nucleus 204 Pb. The 204 Pb has magic number of Z=82. Our aim is to study the excitation energy dependence of NLD parameter for closed shell nuclei

  3. Development of new folate-based PET radiotracers: preclinical evaluation of 68Ga-DOTA-folate conjugates

    International Nuclear Information System (INIS)

    Fani, Melpomeni; Maecke, Helmut R.; Wang, Xuejuan; Nicolas, Guillaume; Medina, Christelle; Raynal, Isabelle; Port, Marc

    2011-01-01

    A number of 111 In- and 99m Tc-folate-based tracers have been evaluated as diagnostic agents for imaging folate receptor (FR)-positive tumours. A 68 Ga-folate-based radiopharmaceutical would be of great interest, combining the advantages of PET technology and the availability of 68 Ga from a generator. The aim of the study was to develop a new 68 Ga-folate-based PET radiotracer. Two new DOTA-folate conjugates, named P3026 and P1254, were synthesized using the 1,2-diaminoethane and 3-{2-[2-(3-amino-propoxy)-ethoxy]-ethoxy}-propylamine as a spacer, respectively. Both conjugates were labelled with 67/68 Ga. Binding affinity, internalization and externalization studies were performed using the FR-positive KB cell line. Biodistribution and PET/CT imaging studies were performed in nude mice, on a folate-deficient diet, bearing KB and HT1080 (FR-negative) tumours, concurrently. The new radiotracers were evaluated comparatively to the reference molecule 111 In-DTPA-folate ( 111 In-P3139). The K d values of 67/68 Ga-P3026 (4.65 ± 0.82 nM) and 67/68 Ga-P1254 (4.27 ± 0.42 nM) showed high affinity for the FR. The internalization rate followed the order 67/68 Ga-P3026 > 67/68 Ga-P1254 > 111 In-P3139, while almost double cellular retention was found for 67/68 Ga-P3026 and 67/68 Ga-P1254, compared to 111 In-P3139. The biodistribution data of 67/68 Ga-DOTA-folates showed high and receptor-mediated uptake on the FR-positive tumours and kidneys, with no significant differences compared to 111 In-P3139. PET/CT images, performed with 68 Ga-P3026, showed high uptake in the kidneys and clear visualization of the FR-positive tumours. The DOTA-folate conjugates can be efficiently labelled with 68 Ga in labelling yields and specific activities which allow clinical application. The characteristics of the 67/68 Ga-DOTA-folates are comparable to 111 In-DTPA-folate, which has already been used in clinical trials, showing that the new conjugates are promising candidates as PET radiotracers

  4. Application of radiotracers in the assessment of prophylactic role of zinc in experimental model of colon carcinogenesis

    International Nuclear Information System (INIS)

    Dani, Vijayata; Vaiphei, K.; Dhawan, D.K.

    2010-01-01

    Full text: The present study elucidated the modulatory effects of zinc in 1,2 dimethylhydrazine (DMH) induced colon carcinogenesis using radiotracer techniques. Rats were segregated into four groups viz., untreated control, DMH treated, zinc treated, DMH+zinc treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/Kg body weight) for 16 weeks. Zinc was supplemented to rats at a dose level of 227mg/L in drinking water, ad libitum. The prophylactic role of zinc was assessed by following radiotracer techniques viz: whole body biological half life of 65 Zn and 65 Zn biodistribution, subcellular distribution, uptake of 3 H-Thymidine to assess rate of DNA synthesis, radiorespirometric determination of 14 C-D-Glucose metabolism and in-vitro uptake of labeled aminoacids. The statistical significance of the data has been determined by using one way analysis of variance (ANOVA) followed by multiple post - hoc test. The carcinogenic state in the animals was confirmed by histopathological examination, whereby, well-differentiated signs of dysplasia were evident in colonic tissue sections of DMH treated rats. The biokinetics study of zinc revealed a significant decrease in the biological half life of 65 Zn. Also, DMH treatment caused a significant increase in the percent uptake values of 65 Zn in the colon, small intestine, kidney and blood, whereas a significant decrease was observed in the liver. The uptake rates of amino acids viz: 14 C-glycine, 14 C-alanine and 14 C-lysine were significantly higher in the DMH treated colons. Moreover, a significant increase in the uptake and turnover of 14 C-D-Glucose was also observed after DMH treatment. A significant increase in the ( 3 H)-thymidine uptake was observed following 16 weeks DMH treatment. However, supplementation of zinc significantly reversed the proliferative effect of DMH as evidenced by ameliorating the altered parameters. Radiotracer techniques play an important role in assessing

  5. Application of 140La and 24Na as intrinsic radiotracers for investigating catalyst dynamics in FCCUs.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Nair, A G C; Tomar, B S; Nathaniel, T N; Reddy, A V R; Singh, Gursharan

    2009-09-01

    Instrumental neutron activation analysis (INAA) of fluid catalytic cracking (FCC) catalyst samples was carried out with an objective to identify activable elements and evaluate its suitability for use as an intrinsic radiotracer for tracing catalyst itself in Fluid Catalytic Cracking Units (FCCUs) used in petroleum refining. Two catalyst samples obtained from two different refineries were analyzed. Twelve different elements were identified in each catalyst sample and their respective concentrations were determined. From the recorded gamma-ray spectra, it was found that lanthanum-140 ((140)La) and sodium-24 ((24)Na) were the predominantly present and suitable radionuclides that could be used as radiotracers for tracing catalyst in FCCUs. Lanthanum being present in much higher concentration forms the major component of the radiotracer after irradiation. Based on the results of INAA, appropriate quantities of the catalyst samples were irradiated with neutrons to produce the desired amount of activity of lanthanum-140 and sodium-24 to be used as radiotracers for tracing the catalyst itself in a pilot as well as an industrial-scale FCCU. The residence time distribution (RTD) of catalyst was measured and analyzed to determine mean residence time (MRT). The axial dispersion model (ADM) was used to simulate the measured RTD data and investigate the degree of axial mixing. The results of the experiments were used to improve the design of pilot-scale FCCU and optimize the performance of the industrial-scale FCCU.

  6. Determination of retention period of sewage in a filtration plant using radiotracer technique

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.; Kirti

    1979-01-01

    A radiotracer investigation was carried out at Dadar sewage purification plant, Bombay, for measuring the retention period of a trickling filter unit. The method is based on the addition of 82 Br tracer in the form of NH 4 Br solution at the inlet and continuous recording of the tracer at the flow stream. Results obtained in the actual investigation are also given. (auth.)

  7. The radiochemical purity of radiotracers as the criterion of their usefulness in investigations of hydrocarbons distillation

    International Nuclear Information System (INIS)

    Kolaczkowski, M.

    1976-01-01

    Among numerous analytic techniques of separation and analysis of radioactive products gas radiochromatography has proved to be particularly suitable. Organic bromides labelled with 82 Br-radionuclide are investigated. The analytic gas chromatographs equipped with appropriately constructed radiochromatographic attachments are used. The results of radiochemical purity determination of radiotracers are compared for various techniques. (author)

  8. Radiotracer investigation of the cold-vapour atomic absorption method of analysis for trace mercury

    International Nuclear Information System (INIS)

    Stuart, D.C.

    1978-01-01

    Because of certain problems found in application of the atomic absorption method for trace analysis of mercury, a careful check of the procedures used was undertaken, with radiotracer mercury to facilitate the investigation. The results obtained, in conjunction with those of sample ashing procedures, indicate that the method is less straightforward than its simplicity suggests. (Auth.)

  9. Persistent cannabis dependence and alcohol dependence represent risks for midlife economic and social problems: A longitudinal cohort study

    Science.gov (United States)

    Cerdá, Magdalena; Moffitt, Terrie E.; Meier, Madeline H.; Harrington, HonaLee; Houts, Renate; Ramrakha, Sandhya; Hogan, Sean; Poulton, Richie; Caspi, Avshalom

    2016-01-01

    With the increasing legalization of cannabis, understanding the consequences of cannabis use is particularly timely. We examined the association between cannabis use and dependence, prospectively assessed between ages 18–38, and economic and social problems at age 38. We studied participants in the Dunedin Longitudinal Study, a cohort (n=1,037) followed from birth to age 38. Study members with regular cannabis use and persistent dependence experienced downward socioeconomic mobility, more financial difficulties, workplace problems, and relationship conflict in early midlife. Cannabis dependence was not linked to traffic-related convictions. Associations were not explained by socioeconomic adversity, childhood psychopathology, achievement orientation, or family structure; cannabis-related criminal convictions; early onset of cannabis dependence; or comorbid substance dependence. Cannabis dependence was associated with more financial difficulties than alcohol dependence; no difference was found in risks for other economic or social problems. Cannabis dependence is not associated with fewer harmful economic and social problems than alcohol dependence. PMID:28008372

  10. PET imaging of HSV1-tk mutants with acquired specificity toward pyrimidine- and acycloguanosine-based radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Likar, Yury; Dobrenkov, Konstantin; Olszewska, Malgorzata; Shenker, Larissa; Hricak, Hedvig; Ponomarev, Vladimir [Memorial Sloan-Kettering Cancer Center, Molecular Imaging Laboratory, Department of Radiology, New York, NY (United States); Cai, Shangde [Memorial Sloan-Kettering Cancer Center, Radiochemistry/Cyclotron Core Facility, New York, NY (United States)

    2009-08-15

    The aim of this study was to create an alternative mutant of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene with reduced phosphorylation capacity for acycloguanosine derivatives, but not pyrimidine-based compounds that will allow for successful PET imaging. A new mutant of HSV1-tk reporter gene, suitable for PET imaging using pyrimidine-based radiotracers, was developed. The HSV1-tk mutant contains an arginine-to-glutamine substitution at position 176 (HSV1-R176Qtk) of the nucleoside binding region of the enzyme. The mutant-gene product showed favorable enzymatic characteristics toward pyrimidine-based nucleosides, while exhibiting reduced activity with acycloguanosine derivatives. In order to enhance HSV1-R176Qtk reporter activity with pyrimidine-based radiotracers, we introduced the R176Q substitution into the more active HSV1-sr39tk mutant. U87 human glioma cells transduced with the HSV1-R176Qsr39tk double mutant reporter gene showed high {sup 3}H-FEAU pyrimidine nucleoside and low {sup 3}H-penciclovir acycloguanosine analog uptake in vitro. PET imaging also demonstrated high {sup 18}F-FEAU and low {sup 18}F-FHBG accumulation in HSV1-R176Qsr39tk+ xenografts. The feasibility of imaging two independent nucleoside-specific HSV1-tk mutants in the same animal with PET was demonstrated. Two opposite xenografts expressing the HSV1-R176Qsr39tk reporter gene and the previously described acycloguanosine-specific mutant of HSV1-tk, HSV1-A167Ysr39tk reporter gene, were imaged using a short-lived pyrimidine-based {sup 18}F-FEAU and an acycloguanosine-based {sup 18}F-FHBG radiotracer, respectively, administered on 2 consecutive days. We conclude that in combination with acycloguanosine-specific HSV1-A167Ysr39tk reporter gene, a HSV1-tk mutant containing the R176Q substitution could be used for PET imaging of two different cell populations or concurrent molecular biological processes in the same living subject. (orig.)

  11. Study of nuclear level density parameter and its temperature dependence

    International Nuclear Information System (INIS)

    Nasrabadi, M. N.; Behkami, A. N.

    2000-01-01

    The nuclear level density ρ is the basic ingredient required for theoretical studies of nuclear reaction and structure. It describes the statistical nuclear properties and is expressed as a function of various constants of motion such as number of particles, excitation energy and angular momentum. In this work the energy and spin dependence of nuclear level density will be presented and discussed. In addition the level density parameter α will be extracted from this level density information, and its temperature and mass dependence will be obtained

  12. Spin-Dependent Transport through Chiral Molecules Studied by Spin-Dependent Electrochemistry

    Science.gov (United States)

    2016-01-01

    Conspectus Molecular spintronics (spin + electronics), which aims to exploit both the spin degree of freedom and the electron charge in molecular devices, has recently received massive attention. Our recent experiments on molecular spintronics employ chiral molecules which have the unexpected property of acting as spin filters, by way of an effect we call “chiral-induced spin selectivity” (CISS). In this Account, we discuss new types of spin-dependent electrochemistry measurements and their use to probe the spin-dependent charge transport properties of nonmagnetic chiral conductive polymers and biomolecules, such as oligopeptides, L/D cysteine, cytochrome c, bacteriorhodopsin (bR), and oligopeptide-CdSe nanoparticles (NPs) hybrid structures. Spin-dependent electrochemical measurements were carried out by employing ferromagnetic electrodes modified with chiral molecules used as the working electrode. Redox probes were used either in solution or when directly attached to the ferromagnetic electrodes. During the electrochemical measurements, the ferromagnetic electrode was magnetized either with its magnetic moment pointing “UP” or “DOWN” using a permanent magnet (H = 0.5 T), placed underneath the chemically modified ferromagnetic electrodes. The spin polarization of the current was found to be in the range of 5–30%, even in the case of small chiral molecules. Chiral films of the l- and d-cysteine tethered with a redox-active dye, toludin blue O, show spin polarizarion that depends on the chirality. Because the nickel electrodes are susceptible to corrosion, we explored the effect of coating them with a thin gold overlayer. The effect of the gold layer on the spin polarization of the electrons ejected from the electrode was investigated. In addition, the role of the structure of the protein on the spin selective transport was also studied as a function of bias voltage and the effect of protein denaturation was revealed. In addition to

  13. Synthesis of a new technetium radiotracer containing para-toluidine by tridentate chelation (N,N,O)

    International Nuclear Information System (INIS)

    Makhloufi, Amel

    2011-01-01

    Neuro degenerative diseases (Alzheimer, Parkinson, Creutzfeld-Jacob. and others) have an increasingly important impact as well on the economic plan as social. The diagnosis procedure and current therapies remain expensive and the assumption of responsibility of the patient is seldom assured. These last years, the development of new radiopharmaceuticals with aiming diagnosis procedure started again the interest for the search for new molecules. The asset of the synthesis of our technetium radiotracer, a tridentate chelate complex (N, N, O) resides in the facility of its obtaining; marking with the kit Alberto is done at a temperature about 90 degree approximately and this could consequently facilitate its implementation in the units of radiodiagnosis. Of lipophilic nature, neutral and of suitable molecular weight, the main challenge for this molecule would be to check its capacity to cross the blood-brain barrier by studying its cerebral extraction.

  14. Delineation of heavy metal contamination pathways (seawater, food and sediment) in tropical oysters from New Caledonia using radiotracer techniques

    International Nuclear Information System (INIS)

    Hedouin, Laetitia; Metian, Marc; Teyssie, Jean-Louis; Fichez, Renaud; Warnau, Michel

    2010-01-01

    Bioaccumulation of Ag, Cd, Co, Cr and Zn was studied in the oysters Isognomon isognomon and Malleus regula, using highly sensitive radiotracer techniques. Metals were readily bioconcentrated from the dissolved phase. Sediment exposures indicated a low bioavailability of sediment-bound metals (3-5 orders of magnitude lower than dissolved metals). In both seawater and sediment experiments, the two oysters displayed similar bioaccumulation behaviour towards all metals but Ag. Indeed, Ag was much more efficiently incorporated and retained in I. isognomon. Metals ingested with food (phytoplankton) were efficiently assimilated (34-77%) and strongly retained in oyster tissues (T b1/2 ≥ 20 d). Estimation of the relative contribution of each exposure pathway indicated that for both species sediment was the dominant pathway for Co and Cd, whereas food was the major source of Zn. Regarding Ag, seawater was the main source for I. isognomon (86%), whereas sediment was the predominant route for M. regula (92%).

  15. A radiotracer technique for the migration of inorganic contaminants into dry food from packaging made from recycled paper and board

    International Nuclear Information System (INIS)

    Aston, D.S.J.; Parry, S.J.

    2005-01-01

    A radiotracer method, initially developed to analyze migration from retail plastic food packaging into food simulants, has been developed to assess the measurement of inorganic contaminants migrating from recycled paper and board into real food. This new radiotracer method has been applied to the study of 10 food samples and their corresponding recycled paper and board packaging. Samples of paper and board were irradiated in a thermal neutron flux of 1.26 x 10 16 n x m -2 x s -1 for 15 hours to activate elements of interest. After a decay period of 10 days the paper and board was placed in contact with the corresponding foodstuff. The food was analyzed for any radioactivity migrating from the packaging by gamma-ray spectrometry. Samples were analyzed regularly during the 90 days contact time. Detection limits for the determination of migration was as low as a few μg/kg in the food. Results from the migration study have shown that, of the 60 elements measured, only Zn and Fe were detected in food, at concentrations of 0.012-0.25, and 0.045-0.11 mg/kg, respectively. This was despite the recycled paper and board samples being highly elevated in many other elements such as Cr (0.9-15.1 mg/kg) and Ba (3.3-75.4 mg/kg). The level of migration of Zn and Fe into food from packaging was insignificant compared to the UK recommended daily allowances of 15 mg, and, therefore, represented no hazard to human health. (author)

  16. SU-E-I-80: Beta-Minus Emitting Radiotracers Improves Molecular Endoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, C; Ma, X; Sun, C; Pratx, G; Cheng, Z; Xing, L [Stanford University, Stanford, CA (United States)

    2014-06-01

    Purpose: Molecular Endoscopy using Cerenkov Luminescence can be used to monitor the distribution of many clinically-available PET and SPECT probes for endoscopic applications. A main limitation of Cerenkov is its limited sensitivity to small concentrations of radiotracer when using light guides s. Herein we demonstrate that the use of a high energy beta emitting radioisotope, exemplified here with 90Y provides superior sensitivity to 18F because of its higher light output and its lack of corresponding gamma emission. Methods: A series of phantom experiments were performed to compare the sensitivity and noise of the CLE system for imaging 90Y and 18F. Three vials of known concentrations of 90Y (0.008 μCi, 0.08 μCi, 1 μCi) were placed in centrifuge tubes and isolated from each other. One vial of 18F (100 μCi) was placed in the imaging chamber and imaged over the course of decay (19 hours, 43 minutes, or ∼10 half-lives). Image time-points were formed from 5-minute integrations. Results: Using an SNR of 10 to define the noise-floor, the 90Y minimum detectable activity was 0.056 μCi. To the contrast, the minimum detectable activity for 18F was 11.63 μCi. These data demonstrate a 207-fold improvement in SNR of 90Y compared to 18F, when controlled for activity. Conclusion: This study demonstrated that a pure β- radionuclide such as 90Y be used is superior to 18F for Cerenkov Endoscopy. Further study is needed to demonstrate its utility in preclinical studies, endoscopic applications, intraoperative, and radiotherapy applications.

  17. Production of gaseous radiotracers CH3I and I2 through Na123I salt

    International Nuclear Information System (INIS)

    Candeiro, R.E.M.; Pereira, W.P.

    2011-01-01

    The objective of the present work was to develop, separately, methodology for production of two gaseous tracers through the sodium iodide NaI marked with 123 I. Found in the nature in form different, the iodine has been used in diverse works in the area of the industry and health. These two forms of the gaseous iodine, the methyl iodide, CH 3 I, and molecular iodine, I 2 , are very unstable and volatile in the ambient temperature and presents different problems in clean-up and monitoring systems. The syntheses were processed with sodium iodide (NaI) 1M aqueous solution marked with 1 23I . The production of gas I 2 was realized with in chlorine acid (HCl) and sodium iodate salt (NaIO 3 ) and the CH 3 I was used, the salt of NaI and the reagent (CH 3 ) 2 SO 4 . The production of gases was initially realized through in unit in glass with an inert material and the purpose was to study the kinetic of reaction and to determine the efficiency of production. The two synthesis occurs in the reaction bottle and after of produced, the gas is stored in the collect bottle that contains a starch solution for fixed the I 2 , and in syntheses of CH 3 I contains a silver nitrate solution for your fixation. To determine the efficiency of production of gases, analytic tests were realized, where the consumption of iodide ions of the bottle of reaction are measured. The optimization of production of the each gaseous tracer was studied varying parameter as: concentration of iodide, concentration of acid and temperature. After, the syntheses of the radiotracers were realized in the compact unit, having been used as main reagent the salt radiated of sodium iodide, Na 123 I. The transportation of elementary iodine and methyl iodine was studied by a scintillation detector NaI (2 x 2)' positioned in the reaction bottle. (author)

  18. SPECT imaging with the serotonin transporter radiotracer [123I]p ZIENT in nonhuman primate brain

    International Nuclear Information System (INIS)

    Cosgrove, Kelly P.; Staley, Julie K.; Baldwin, Ronald M.; Bois, Frederic; Plisson, Christophe; Al-Tikriti, Mohammed S.; Seibyl, John P.; Goodman, Mark M.; Tamagnan, Gilles D.

    2010-01-01

    Introduction: Serotonin dysfunction has been linked to a variety of psychiatric diseases; however, an adequate SPECT radioligand to probe the serotonin transporter system has not been successfully developed. The purpose of this study was to characterize and determine the in vivo selectivity of iodine-123-labeled 2β-carbomethoxy-3β-(4'-((Z)-2-iodoethenyl)phenyl)nortropane, [ 123 I]p ZIENT, in nonhuman primate brain. Methods: Two ovariohysterectomized female baboons participated in nine studies (one bolus and eight bolus to constant infusion at a ratio of 9.0 h) to evaluate [ 123 I]p ZIENT. To evaluate the selectivity of [ 123 I]p ZIENT, the serotonin transporter blockers fenfluramine (1.5, 2.5 mg/kg) and citalopram (5 mg/kg), the dopamine transporter blocker methylphenidate (0.5 mg/kg) and the norepinephrine transporter blocker nisoxetine (1 mg/kg) were given at 8 h post-radiotracer injection. Results: In the bolus to constant infusion studies, equilibrium was established by 4-8 h. [ 123 I]p ZIENT was 93% and 90% protein bound in the two baboons and there was no detection of lipophilic radiolabeled metabolites entering the brain. In the high-density serotonin transporter regions (diencephalon and brainstem), fenfluramine and citalopram resulted in 35-71% and 129-151% displacement, respectively, whereas methylphenidate and nisoxetine did not produce significant changes ( 123 I]p ZIENT is a favorable compound for in vivo SPECT imaging of serotonin transporters with negligible binding to norepinephrine and dopamine transporters.

  19. Al18F-NODA-butyric acid: Biological evaluation of a new PET renal radiotracer

    International Nuclear Information System (INIS)

    Lipowska, Malgorzata; Klenc, Jeffrey; Shetty, Dinesh; Nye, Jonathon A.; Shim, Hyunsuk; Taylor, Andrew T.

    2014-01-01

    Introduction: Renal scintigraphy is an important imaging modality for the diagnosis and management of a variety of renal diseases including obstruction and renovascular hypertension as well as the evaluation of absolute and relative kidney function. The goal of this work was to evaluate Al 18 F-NODA-butyric acid (Al 18 F-1) as a potential PET tracer to image the kidneys and monitor renal function by comparing its pharmacokinetic properties with those of 131 I-o-iodohippurate ( 131 I-OIH), the radioactive standard for the measurement of effective renal plasma flow. Methods: Al 18 F-1 was prepared in aqueous conditions using a one-pot Al 18 F-radiofluorination method and its radiochemical purity was determined by HPLC. Biodistribution studies, using 131 I-OIH as an internal control, were performed in normal rats and in rats with renal pedicle ligation. In vitro stability and metabolism of Al 18 F-1 were analyzed by HPLC. Dynamic microPET/CT studies were conducted in normal rats. Results: Al 18 F-1 showed excellent stability in vitro and in vivo. Biodistribution studies in normal rats and in rats with simulated renal failure confirmed that Al 18 F-1 was exclusively cleared through the renal–urinary pathway and that the hepatic/gastrointestinal activity was less for Al 18 F-1 than for 131 I-OIH both at 10 and 60 min. Dynamic PET showed a rapid transit of Al 18 F-1 through the kidneys into the bladder. Conclusion: These results suggest that the easily labeled Al 18 F-based compounds provide a highly promising approach for the development of a PET renal radiotracer that combines superior imaging qualities with a reliable measure of effective renal plasma flow

  20. EXECUTIVE DYSFUNCTION IN ALCOHOL DEPENDENT INDIVIDUALS: A CASE CONTROL STUDY

    Directory of Open Access Journals (Sweden)

    Neethi Valsan

    2016-06-01

    Full Text Available BACKGROUND The use of alcohol is increasingly prevalent in our country. Being a neurotoxin, it tends to affect elective mental capacities. Frontal lobe is found to be most affected by chronic alcohol use. AIM To study the executive functions in alcohol dependent individuals and to determine any relationship with alcohol intake variables. MATERIALS AND METHODS 30 recently detoxified alcohol dependent individuals attending the De-addiction Clinic of Medical College, Kottayam, was compared to 30 controls on four tests of executive functions, namely, Controlled Word Association Test, Trail Making Test, Stroop Test, and Wisconsin Card Sorting Test. Statistical analysis of the data has been done using the Statistical Package for Social Sciences (SPSS Windows version 10. RESULTS Executive function was significantly impaired in the alcohol dependent individuals when compared to normal controls in all the four tests. On analysing the effect of drinking variables on executive functioning, the performance of patients is seen to improve with abstinence in Stroop. Those with a positive family history of ADS in the first degree relatives produced fewer words in verbal fluency. CONCLUSION As the executive impairment remains more or less stable irrespective to the chronicity or amount of alcohol use, it could be assumed that the executive dysfunction observed is a trait marker rather than a state dependent variable.

  1. Is there a relationship between Internet dependence and eating disorders? A comparison study of Internet dependents and non-Internet dependents.

    Science.gov (United States)

    Tao, Z L; Liu, Y

    2009-01-01

    Several studies have examined the underlying psychopathology in overuse of the Internet, including depression, social anxiety, and substance dependence. A relationship between these psychological disorders appears to exist. No links have been established between Internet dependence and eating disorders. Fifty-four Internet dependents were compared with a control group concerning symptomatic aspects of eating disorders and psychological characteristics related to eating disorders. They all belonged to 1199 respondents of Chinese secondary school and college students between the ages of 12 and 25 years old. A Mann-Whitney U-test was used to determine the difference between Internet dependent groups and non-Internet dependent groups concerning Eating Attitudes Test and Eating Disorder Inventory scores. Females and male Internet dependents rated themselves with significantly higher symptomatic aspects of eating disorders than control groups. Female and male Internet dependents showed significantly higher psychological characteristics related to eating disorders than control groups. A relationship between Internet dependence and eating disorders appears to exist.

  2. {sup 99m}Tc-Novobiocin: a novel radiotracer for infection imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shah, S.Q. [Univ. of Peshawar, Nuclear Medicine Research Lab. (NMRL), Peshawar (Pakistan); Khan, M.R. [Univ. of Peshawar, Phyotopharmaceutical and Neutraceuticals Research Lab. (PNRL), Peshawar (Pakistan); Khan, A.U. [Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad (Pakistan)

    2011-07-01

    The radiosynthesis of {sup 99m}Tc-Novobiocin ({sup 99m}Tc-NBN) complex and its suitability as a radiotracer for infection imaging was assessed. The radiochemical purity (RCP) of the {sup 99m}Tc-NBN complex was determined using radio-TLC and radioactive HPLC and biodistribution was studied in artificially infected (A.I.) rats and rabbit, using single well gamma counter (SWGRC) interface with scalar count rate meter (SCRM) and Gamma Camera ({gamma}-CM). The maximum RCP observed for the preparation having 2 mg of NBN, 111 MBq of sodium pertechnetate (Na{sup 99m}TcO{sub 4}) and 125 {mu}L of SnF{sub 2} (1 {mu}g/{mu}L in 0.01 N HCl) at a pH 5.6 was 98.97{+-}0.40% and remained stable >90% up to 120 min. The activity of the {sup 99m}Tc-NBN in the infected muscle (TI) was significantly increased from 6.50{+-}0.15 to 19.00{+-}0.17% and decreased in the inflamed muscle (TII), normal muscle (NT), blood, liver, spleen, stomach and intestine within 120 min. The TI/NT and TII/NT ratios were 7.60{+-}1.08 and 1.60{+-}1.14. The Whole Body Static (WBS) images of A.I. rabbit were obtained at 30, 40, 50 and 60 min after the I.V. administration of 111 MBq of {sup 99m}Tc-NBN to the A.I. rabbit. The stability in saline and serum, higher TI/NT, lower TII/NT ratios and WBS images confirmed the feasibility of the {sup 99m}Tc-NBN complex as an infection imaging agent. (orig.)

  3. 99mTc-Novobiocin: a novel radiotracer for infection imaging

    International Nuclear Information System (INIS)

    Shah, S.Q.; Khan, M.R.; Khan, A.U.

    2011-01-01

    The radiosynthesis of 99m Tc-Novobiocin ( 99m Tc-NBN) complex and its suitability as a radiotracer for infection imaging was assessed. The radiochemical purity (RCP) of the 99m Tc-NBN complex was determined using radio-TLC and radioactive HPLC and biodistribution was studied in artificially infected (A.I.) rats and rabbit, using single well gamma counter (SWGRC) interface with scalar count rate meter (SCRM) and Gamma Camera (γ-CM). The maximum RCP observed for the preparation having 2 mg of NBN, 111 MBq of sodium pertechnetate (Na 99m TcO 4 ) and 125 μL of SnF 2 (1 μg/μL in 0.01 N HCl) at a pH 5.6 was 98.97±0.40% and remained stable >90% up to 120 min. The activity of the 99m Tc-NBN in the infected muscle (TI) was significantly increased from 6.50±0.15 to 19.00±0.17% and decreased in the inflamed muscle (TII), normal muscle (NT), blood, liver, spleen, stomach and intestine within 120 min. The TI/NT and TII/NT ratios were 7.60±1.08 and 1.60±1.14. The Whole Body Static (WBS) images of A.I. rabbit were obtained at 30, 40, 50 and 60 min after the I.V. administration of 111 MBq of 99m Tc-NBN to the A.I. rabbit. The stability in saline and serum, higher TI/NT, lower TII/NT ratios and WBS images confirmed the feasibility of the 99m Tc-NBN complex as an infection imaging agent. (orig.)

  4. Conduction disturbances after TAVR: Electrophysiological studies and pacemaker dependency.

    Science.gov (United States)

    Makki, Nader; Dollery, Jenn; Jones, Danielle; Crestanello, Juan; Lilly, Scott

    Permanent pacemaker (PPM) placement occurs in 5-20% of patients after transcatheter aortic valve replacement (TAVR). Although predictors of pacemaker implantation have been established, features that predispose patients to pacemaker utilization on follow up have not been widely reported. We performed a retrospective review of patients undergoing commercial TAVR between 2011 and 2016. We collated patients that underwent in-hospital PPM implantation and had a follow up of at least 3months. Data abstraction was performed for electrophysiological studies (EPS), pacemaker indication, timing, and device interrogation for pacemaker dependency on follow up. A total of 24 patients received in-hospital PPM post-TAVR (14% of total cohort), and mean follow up was 22months. Indications for PPM included resting complete heart block (CHB; 15/24, 63%), left bundle branch block and abnormal electrophysiological study (EPS; 7/24, 29%), alternating bundle branch block (1/24, 4%) and tachy-brady syndrome (1/24, 4%). Pacemaker dependency (underlying ventricular asystole, complete heart block, or >50% pacing) occurred in 8/24 patients (33%) during follow-up, 7 of whom had resting CHB, and one with CHB invoked during EPS. Pacemaker dependency after TAVR is common among those that exhibited CHB, but not among those with a prolonged HV delay during EPS. Although preliminary, these observations are relevant to management of rhythm disturbances after TAVR, and may inform the practice of EPS-based PPM implantation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Studying the Complex Expression Dependences between Sets of Coexpressed Genes

    Directory of Open Access Journals (Sweden)

    Mario Huerta

    2014-01-01

    Full Text Available Organisms simplify the orchestration of gene expression by coregulating genes whose products function together in the cell. The use of clustering methods to obtain sets of coexpressed genes from expression arrays is very common; nevertheless there are no appropriate tools to study the expression networks among these sets of coexpressed genes. The aim of the developed tools is to allow studying the complex expression dependences that exist between sets of coexpressed genes. For this purpose, we start detecting the nonlinear expression relationships between pairs of genes, plus the coexpressed genes. Next, we form networks among sets of coexpressed genes that maintain nonlinear expression dependences between all of them. The expression relationship between the sets of coexpressed genes is defined by the expression relationship between the skeletons of these sets, where this skeleton represents the coexpressed genes with a well-defined nonlinear expression relationship with the skeleton of the other sets. As a result, we can study the nonlinear expression relationships between a target gene and other sets of coexpressed genes, or start the study from the skeleton of the sets, to study the complex relationships of activation and deactivation between the sets of coexpressed genes that carry out the different cellular processes present in the expression experiments.

  6. Radiosynthesis and ex vivo evaluation of [{sup 11}C]-SIB-1553A as a PET radiotracer for {beta}4 selective subtype nicotinic acetylcholine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Sobrio, Franck [CEA, DSV, I2BM, CINAPS, LDMTEP, Caen, F-14074 (France); Universite de Caen Basse-Normandie, UMR CEA E2, Centre Cyceron, Caen, F-14074 (France)], E-mail: sobrio@cyceron.fr; Quentin, Thomas; Dhilly, Martine; Bourdier, Thomas; Tymciu, Sylvie; Debruyne, Daniele; Barre, Louisa [CEA, DSV, I2BM, CINAPS, LDMTEP, Caen, F-14074 (France); Universite de Caen Basse-Normandie, UMR CEA E2, Centre Cyceron, Caen, F-14074 (France)

    2008-04-15

    [{sup 11}C]-SIB-1553A (({+-})-4-[2-((N-[{sup 11}C]-methyl)-2-pyrrolidinyl)ethyl]thiophenol) was labelled with carbon-11 (t{sub 1/2}=20.4 min) and evaluated in vivo as potential radiotracer for noninvasive assessment of the {beta}4 subunit nicotinic acetylcholine neurotransmission system with positron emission tomography (PET). The labelling precursor was obtained within five steps from N-Boc-prolinal in 45-56% overall yields. The radiosynthesis of [{sup 11}C]-SIB-1553A was achieved by a selective N-[{sup 11}C]-methylation in 32 min with a radiochemical purity greater than 97%, 7.5-30 GBq/{mu}mol of specific radioactivity and 55-65% radiochemical yield (decay corrected, based on [{sup 11}C]methyl iodide). The ex vivo pharmacological profile of [{sup 11}C]-SIB-1553A was evaluated in rats with biodistribution studies in organs and in brain structures by autoradiography. The radiotracer uptake in the brain reached 0.49 %ID/g at 10 min and no brain radiometabolite was detected 40 min after intravenous injection. The quantification of radioactivity in various cerebral structures indicated a significantly higher radioactivity level at 15 min than at 30 min. Among the {beta}4 nAChR subunit-rich structures studied in the rat brain, only the thalamus at 15 and 30 min and the hippocampus at 30 min showed significantly higher uptake. Moreover, competition studies performed with SIB-1553A (15 min before the radiotracer injection) revealed only a low specific binding estimated to 7% of the total binding at 15 min and 13% at 30 min.

  7. Radiopharmacological evaluation of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose as a radiotracer for PET imaging of GLUT5 in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Melinda, E-mail: mwuest@ualberta.c [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Trayner, Brendan J. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Grant, Tina N. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); Jans, Hans-Soenke; Mercer, John R.; Murray, David [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); West, Frederick G. [Department of Chemistry, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada); McEwan, Alexander J.B.; Wuest, Frank [Department of Oncology, University of Alberta - Cross Cancer Institute, Edmonton, AB-T6G 1Z2 (Canada); Cheeseman, Chris I. [Department of Physiology, University of Alberta, Edmonton, AB-T6G 1Z2 (Canada)

    2011-05-15

    Introduction: Several clinical studies have shown low or no expression of GLUT1 in breast cancer patients, which may account for the low clinical specificity and sensitivity of 2-deoxy-2-[{sup 18}F]fluoro-D-glucose ([{sup 18}F]FDG) used in positron emission tomography (PET). Therefore, it has been proposed that other tumor characteristics such as the high expression of GLUT2 and GLUT5 in many breast tumors could be used to develop alternative strategies to detect breast cancer. Here we have studied the in vitro and in vivo radiopharmacological profile of 6-deoxy-6-[{sup 18}F]fluoro-D-fructose (6-[{sup 18}F]FDF) as a potential PET radiotracer to image GLUT5 expression in breast cancers. Methods: Uptake of 6-[{sup 18}F]FDF was studied in murine EMT-6 and human MCF-7 breast cancer cells over 60 min and compared to [{sup 18}F]FDG. Biodistribution of 6-[{sup 18}F]FDF was determined in BALB/c mice. Tumor uptake was studied with dynamic small animal PET in EMT-6 tumor-bearing BALB/c mice and human xenograft MCF-7 tumor-bearing NIH-III mice in comparison to [{sup 18}F]FDG. 6-[{sup 18}F]FDF metabolism was investigated in mouse blood and urine. Results: 6-[{sup 18}F]FDF is taken up by EMT-6 and MCF-7 breast tumor cells independent of extracellular glucose levels but dependent on the extracellular concentration of fructose. After 60 min, 30{+-}4% (n=9) and 12{+-}1% (n=7) ID/mg protein 6-[{sup 18}F]FDF was found in EMT-6 and MCF-7 cells, respectively. 6-deoxy-6-fluoro-D-fructose had a 10-fold higher potency than fructose to inhibit 6-[{sup 18}F]FDF uptake into EMT-6 cells. Biodistribution in normal mice revealed radioactivity uptake in bone and brain. Radioactivity was accumulated in EMT-6 tumors reaching 3.65{+-}0.30% ID/g (n=3) at 5 min post injection and decreasing to 1.75{+-}0.03% ID/g (n=3) at 120 min post injection. Dynamic small animal PET showed significantly lower radioactivity uptake after 15 min post injection in MCF-7 tumors [standard uptake value (SUV)=0

  8. Regional wall thickening in gated myocardial perfusion SPECT in a Japanese population: effect of sex, radiotracer, rotation angles and frame rates

    Energy Technology Data Exchange (ETDEWEB)

    Akhter, Nasima; Nakajima, Kenichi; Okuda, Koichi; Matsuo, Shinro; Yoneyama, Tatsuya; Taki, Junichi; Kinuya, Seigo [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa, Ishikawa (Japan)

    2008-09-15

    Gated single-photon emission computed tomography (SPECT) imaging of myocardium by {sup 99m}Tc and {sup 201}Tl is used extensively to measure quantitative cardiac functional parameters. However, factors affecting normal values for myocardial functional parameters and population-specific standards have not yet been established. The aim of the study was to determine the effect of sex, radiotracer, rotation angles and frame rates on resting myocardial wall thickening (WT) and to develop a Japanese standard of normal values for WT. Data from a total of 202 patients with low possibility of having cardiac problems were collected from nine hospitals throughout Japan. Patients were divided into five groups according to study protocol, and WT was evaluated according to the 17-segment and four-region (basal, mid and apical regions and the apex) polar map distribution. WT was generally higher in women than in men irrespective of the use of radiotracers, rotation angles or frame rates, and the difference was highly significant in the mid and apical regions. In any protocol used, resting myocardial thickening in the apex was higher than in the mid and apical regions, and thickening was lowest in the basal region, suggesting heterogeneous regional myocardial thickening (%) in normal subjects. Different rotation angles showed no significant change on WT, but different frame rates and tracers showed significant WT change in both sexes. Percent thickening of the myocardium was significantly higher in imaging by {sup 99m}Tc-labelled tracers than in {sup 201}Tl. Sex, radiotracers and frame rates had a significant effect on myocardial thickening, and the importance of population-specific standards should be emphasized. A normal database can serve as a standard for gated SPECT evaluation of myocardial thickening in a Japanese population and might be applicable to Asian populations having a similar physique. (orig.)

  9. Evaluation of Fluorine-18-Labeled α1(I-N-Telopeptide Analogs as Substrate-Based Radiotracers for PET Imaging of Melanoma-Associated Lysyl Oxidase

    Directory of Open Access Journals (Sweden)

    Manuela Kuchar

    2018-04-01

    Full Text Available Accumulating evidence suggests an unequivocal role of lysyl oxidases as key players of tumor progression and metastasis, which renders this enzyme family highly attractive for targeted non-invasive functional imaging of tumors. Considering their function in matrix remodeling, malignant melanoma appears as particularly interesting neoplasia in this respect. For the development of radiotracers that enable PET imaging of the melanoma-associated lysyl oxidase activity, substrates derived from the type I collagen α1 N-telopeptide were labeled with fluorine-18 using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB as prosthetic reagent. With regards to potential crosslinking to tumor-associated collagen in vivo, their interaction with triple-helical type I collagen was studied by SPR. A mouse model of human melanoma was established on the basis of the A375 cell line, for which the expression of the oncologically relevant lysyl oxidase isoforms LOX and LOXL2 was demonstrated in Western blot and immunohistochemical experiments. The radiopharmacological profiles of the peptidic radiotracers were evaluated in normal rats and A375 melanoma-bearing mice by ex vivo metabolite analysis, whole-body biodistribution studies and dynamic PET imaging. Out of three 18F-labeled telopeptide analogs, the one with the most favorable substrate properties has shown favorable tumor uptake and tumor-to-muscle ratio. Lysyl oxidase-mediated tumor uptake was proven by pharmacological inhibition using β-aminopropionitrile and by employing negative-control analogs of impeded or abolished targeting capability. The latter were obtained by substituting the lysine residue by ornithine and norleucine, respectively. Comparing the tumor uptake of the lysine-containing peptide with that of the non-functional analogs indicate the feasibility of lysyl oxidase imaging in melanoma using substrate-based radiotracers.

  10. Evaluation of Fluorine-18-Labeled α1(I)-N-Telopeptide Analogs as Substrate-Based Radiotracers for PET Imaging of Melanoma-Associated Lysyl Oxidase.

    Science.gov (United States)

    Kuchar, Manuela; Neuber, Christin; Belter, Birgit; Bergmann, Ralf; Lenk, Jens; Wodtke, Robert; Kniess, Torsten; Steinbach, Jörg; Pietzsch, Jens; Löser, Reik

    2018-01-01

    Accumulating evidence suggests an unequivocal role of lysyl oxidases as key players of tumor progression and metastasis, which renders this enzyme family highly attractive for targeted non-invasive functional imaging of tumors. Considering their function in matrix remodeling, malignant melanoma appears as particularly interesting neoplasia in this respect. For the development of radiotracers that enable PET imaging of the melanoma-associated lysyl oxidase activity, substrates derived from the type I collagen α1 N-telopeptide were labeled with fluorine-18 using N -succinimidyl 4-[ 18 F]fluorobenzoate ([ 18 F]SFB) as prosthetic reagent. With regards to potential crosslinking to tumor-associated collagen in vivo , their interaction with triple-helical type I collagen was studied by SPR. A mouse model of human melanoma was established on the basis of the A375 cell line, for which the expression of the oncologically relevant lysyl oxidase isoforms LOX and LOXL2 was demonstrated in Western blot and immunohistochemical experiments. The radiopharmacological profiles of the peptidic radiotracers were evaluated in normal rats and A375 melanoma-bearing mice by ex vivo metabolite analysis, whole-body biodistribution studies and dynamic PET imaging. Out of three 18 F-labeled telopeptide analogs, the one with the most favorable substrate properties has shown favorable tumor uptake and tumor-to-muscle ratio. Lysyl oxidase-mediated tumor uptake was proven by pharmacological inhibition using β-aminopropionitrile and by employing negative-control analogs of impeded or abolished targeting capability. The latter were obtained by substituting the lysine residue by ornithine and norleucine, respectively. Comparing the tumor uptake of the lysine-containing peptide with that of the non-functional analogs indicate the feasibility of lysyl oxidase imaging in melanoma using substrate-based radiotracers.

  11. Spectrum analysis of radiotracer residence time distribution for industrial and environmental applications

    International Nuclear Information System (INIS)

    Kasban, H.; Ashraf Hamid

    2014-01-01

    Radiotracer signal analysis and recognition still represents challenges in industrial and environmental applications specially in residence time distribution (RTD) measurement. This paper presents a development for the RTD signal recognition method that is based on power density spectrum (PDS). In this development, the features are extracted from the signals and/or from their higher-orders statistics (HOS) (Bispectrum and Trispectrum) instead of PDS. The HOS are estimated using direct, indirect and parametric estimations. The recognition results are analyzed and compared for different HOS estimation in order to select the best HOS estimation method for the purpose of RTD signal recognition. The artificial neural networks are used for training and testing of the proposed method. The proposed method is tested using RTD signals obtained from the measurements carried out using radiotracer technique. The simulation results show that the parametric estimation of the Trispectrum gives the higher recognition rate and is the most reliable for the RTD signal recognition. (author)

  12. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of /sup 11/C, /sup 18/F and /sup 13/N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume.

  13. Estimation of shell thickness in a continuously cast steel billet using radiotracers

    International Nuclear Information System (INIS)

    Prasad, A.S.; Pandey, J.C.; Kaur, G.

    1994-01-01

    In the continuous casting of steel, one of the factors which limits the rate of faster withdrawal of the casting from the mould is the thickness of the solid shell below the mould. If the shell can not contain the liquid pool, breakouts occur and process of casting disrupts. Estimates of shell thickness have been made on the basis of heat- transfer considerations. The shell thickness could also be delineated, to some extent, by adding radiotracers during casting and subsequently determining the dispersion of radioactivity by autoradiography. The paper presents the results of the estimation of shell thickness based on the heat-transfer model and validation of the model by plant trials using radiotracers. (author). 11 refs., 5 figs., 1 tab

  14. The applicability of radiotracers for the investigation of the distillation of hydrocarbons

    International Nuclear Information System (INIS)

    Graczyk, J.; Iller, E.

    1976-01-01

    The use of radioactive tracers provide valuable methods for the investigation of distillation processes and have been applied to determine the characteristics of material streams, the dynamics of flowing phases and the composition in various parts of the distillation equipment. A method is proposed for testing individual radiotracers emplozemployed for the investigation of the distillation of hydrocarbons. The method consists in laboratory-scale distillation of a tracer together with a multicomponent hydrocarbon mixture, namely a gasoline fraction. The purification efficiency, distillation characteristics, and effective radiochemical purity of several tracers (reactor activated bromobenzene and synthesized C 3 H 7 82 Br, C 4 H 9 82 Br, C 5 H 11 82 Br) have been investigated. The distillation characteristics of bromohydrocarbons labelled with 82 Br and selected hydrocarbons tagged with 14 C (benzene and cumene) have been compared. The radiotracers investigated were employed for the determination of the hydrodynamic parameters of hydrocarbon distillation in laboratory packed columns and a commercial distillation tower. (author)

  15. A radiotracer method for the dynamic measurement of the in-process inventory of dissolved materials

    International Nuclear Information System (INIS)

    Iqbal, M.N.; Gardner, R.P.; Verghese, K.

    1990-01-01

    A radioactive tracer method and the associated mathematical models have been developed to determine the in-process inventory of zirconium in a pulse column from the counting rate data taken at the exits of the aqueous and organic phases after an impulse injection of the radiotracer at the aqueous-phase inlet. Model parameters were obtained by applying a nonlinear least-squares fitting of the models to the experimental data. The total inventory of zirconium present in the pulse column under different operating conditions was determined by calculating the average residence time of zirconium in the system using these model parameters. The results indicate that the radiotracer technique provides a viable means of on-line determination of solute mass holdup. (author)

  16. Application of radiotracers in an exotic field of botany. How to feed carnivorous plants

    International Nuclear Information System (INIS)

    Steinhauser, G.; Musilek, A.; Sterba, J.H.; Bichler, M.; Adlassnig, W.; Peroutka, M.; Lichtscheidl, I.K.

    2007-01-01

    In this paper, methods for the application of radiotracers in the Cobra Lily (Darlingtonia californica), a carnivorous pitcher plant, are described. The uptake of radiotracers such as 42 K and 54 Mn into the pitcher trap in aqueous solution could be proven, whereas uptake of 59 Fe ions could not be observed. No-carrier-added 54 Mn was taken up by the plants, regardless of extremely low concentrations. In contrast to earlier experiments using 14 C and 15 N-based tracers, the methodology presented allows quick, simple and reliable quantification of the nutrient uptake. The results of our experiments lead to a deeper biological understanding concerning the trace element household of this carnivorous plant and the absorption of micro- and macronutrients from trapped prey. (author)

  17. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of 11 C, 18 F and 13 N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume

  18. Study of heavy quarkonium with energy dependent potential

    International Nuclear Information System (INIS)

    Gupta, Pramila; Mehrotra, I

    2009-01-01

    It is well known that charmonium and bottonium states can be calculated by using a nonrelativistic Schrodinger equation. The basic reasons are: 1) the mass of charm and bottom quarks is much larger than QCD scale, which makes this system free of strong normalization effects and 2) the binding energy is small compared to the mass energy ψ and γ states in terms of nonrelativistic qq system governed by more or less phenomenological potentials. In the present work we have studied mass spectra of charmonium and bottonium using the following energy dependent model in the framework of nonrelativistic Schrodinger equation

  19. Structural study of surfactant-dependent interaction with protein

    Energy Technology Data Exchange (ETDEWEB)

    Mehan, Sumit; Aswal, Vinod K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, Joachim [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2015-06-24

    Small-angle neutron scattering (SANS) has been used to study the complex structure of anionic BSA protein with three different (cationic DTAB, anionic SDS and non-ionic C12E10) surfactants. These systems form very different surfactant-dependent complexes. We show that the structure of protein-surfactant complex is initiated by the site-specific electrostatic interaction between the components, followed by the hydrophobic interaction at high surfactant concentrations. It is also found that hydrophobic interaction is preferred over the electrostatic interaction in deciding the resultant structure of protein-surfactant complexes.

  20. Dose-dependent transitions in mechanisms of toxicity: case studies

    International Nuclear Information System (INIS)

    Slikker, William; Andersen, Melvin E.; Bogdanffy, Matthew S.; Bus, James S.; Cohen, Steven D.; Conolly, Rory B.; David, Raymond M.; Doerrer, Nancy G.; Dorman, David C.; Gaylor, David W.; Hattis, Dale; Rogers, John M.; Setzer, R. Woodrow; Swenberg, James A.; Wallace, Kendall

    2004-01-01

    Experience with dose response and mechanisms of toxicity has shown that multiple mechanisms may exist for a single agent along the continuum of the full dose-response curve. It is highly likely that critical, limiting steps in any given mechanistic pathway may become overwhelmed with increasing exposures, signaling the emergence of new modalities of toxic tissue injury at these higher doses. Therefore, dose-dependent transitions in principal mechanisms of toxicity may occur, and could have significant impact on the interpretation of reference data sets for risk assessment. To illustrate the existence of dose-dependent transitions in mechanisms of toxicity, a group of academic, government, and industry scientists, formed under the leadership of the ILSI Health and Environmental Sciences Institute (HESI), developed a series of case studies. These case studies included acetaminophen, butadiene, ethylene glycol, formaldehyde, manganese, methylene chloride, peroxisome proliferator-activated receptor (PPAR), progesterone/hydroxyflutamide, propylene oxide, vinyl acetate, vinyl chloride, vinylidene chloride, and zinc. The case studies formed the basis for technical discourse at two scientific workshops in 2003

  1. Quality control for measurement of soil samples containing 237Np and 241Am as radiotracer

    International Nuclear Information System (INIS)

    Sha Lianmao; Zhang Caihong; Song Hailong; Ren Xiaona; Han Yuhu; Zhang Aiming; Chu Taiwei

    2003-01-01

    This paper reports quality control (QC) for the measurement of soil samples containing 237 Np and 241 Am as radiotracers in migration test of transuranic nuclides. All of the QC were done independently by the QA members of analytical work. It mainly included checking 5%-10% of the total analyzed samples; preparing blank samples, blind replicate sample and spiked samples used as quality control samples to check the quality of analytical work

  2. Abnormal gastrointestinal accumulation of radiotracer by gastric bleeding during 99mTc-MDP bone scintigraphy

    International Nuclear Information System (INIS)

    Chun, Kyung A.; Lee, Sang Woo; Lee, Jae Tae; Lee, Kyu Bo

    1998-01-01

    We present a case in which a patient with acute hemorrhagic gastritis demonstrated abnormal gastrointestinal accumulation of radiotracer during 99m Tc-methylene diphosphonate (MDP) skeletal scintigraphy. A hemorrhagic gastritis was subsequently demonstrated by endoscopy. The mechanism for the intestinal localization of 99m Tc-MDP in this patients is not clear, but we guess that the extravasated blood containing the radiopharmaceutical cannot recirculate and stays at the bleeding site, so we can see the intestinal activity

  3. Instrumental neutron activation analysis of human hair and related radiotracer experiments on washing and leaching

    International Nuclear Information System (INIS)

    Das, H.A.; Hoede, D.; Sloot, H.A. van der; Herber, R.F.M.

    1981-11-01

    The work done under the IAEA-contract 2440/RB is summarized. The aim was to develop a fast and reliable system for the determination of tracer elements in human head hair by instrumental neutron activation analysis (INAA) and radiotracer washing experiments. The standardized procedure for INAA was applied to hair samples collected by the Coronel Laboratory of the University of Amsterdam. The correlation between trace element contents is considered

  4. A radiotracer technique for testing a high pressure gas compressor for oil leakage

    International Nuclear Information System (INIS)

    Eapen, A.C.; Kirti; Jain, S.K.; Gupta, P.P.

    1979-01-01

    The radiotracer investigations carried out at NOCIL, Bombay, to measure the amount of lubrication oil present in the gas being compressed in a 1000 H.P. centrifugal compressor are described. By injecting a few mCi 131 I labelled glyceryl trioleate tracer and monitoring the radioactivity of the outlet gas for about 20 hours, the extent of the oil present in the gas could be determined. (auth.)

  5. Residence time distribution measurements in a pilot-scale poison tank using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Goswami, Sunil; Samantray, J S; Sharma, V K; Maheshwari, N K

    2015-09-01

    Various types of systems are used to control the reactivity and shutting down of a nuclear reactor during emergency and routine shutdown operations. Injection of boron solution (borated water) into the core of a reactor is one of the commonly used methods during emergency operation. A pilot-scale poison tank was designed and fabricated to simulate injection of boron poison into the core of a reactor along with coolant water. In order to design a full-scale poison tank, it was desired to characterize flow of liquid from the tank. Residence time distribution (RTD) measurement and analysis was adopted to characterize the flow dynamics. Radiotracer technique was applied to measure RTD of aqueous phase in the tank using Bromine-82 as a radiotracer. RTD measurements were carried out with two different modes of operation of the tank and at different flow rates. In Mode-1, the radiotracer was instantaneously injected at the inlet and monitored at the outlet, whereas in Mode-2, the tank was filled with radiotracer and its concentration was measured at the outlet. From the measured RTD curves, mean residence times (MRTs), dead volume and fraction of liquid pumped in with time were determined. The treated RTD curves were modeled using suitable mathematical models. An axial dispersion model with high degree of backmixing was found suitable to describe flow when operated in Mode-1, whereas a tanks-in-series model with backmixing was found suitable to describe flow of the poison in the tank when operated in Mode-2. The results were utilized to scale-up and design a full-scale poison tank for a nuclear reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Preparation of the Nanostructured Radioisotope Metallic Oxide by Neutron Irradiation for Use as Radiotracers

    Directory of Open Access Journals (Sweden)

    Sang-Ei Seo

    2017-10-01

    Full Text Available Metallic oxides manganese dioxide (MnO2, samarium oxide (Sm2O3, and dysprosium oxide (Dy2O3 with nanorod-like structures were synthesized by the hydrothermal synthesis method, respectively. Subsequently, the nanostructured radioisotopes MnO2 with Mn-56, Sm2O3 with Sm-153, and Dy2O3 with Dy-165 were prepared by neutron irradiation from the HANARO research reactor, respectively. The three different elements, Mn, Sm, and Dy, were selected as radiotracers because these elements can be easily gamma-activated from neutrons (activation limits: 1 picogram (Dy, 1–10 picogram (Mn, 10–100 picogram (Sm. Furthermore, the synthesized radioisotopes can be used as radiotracers in Prompt Gamma Neutron Activation Analysis as the rare earth metals Dy and Sm were not present in the Korean environment. The successful synthesis of the radioisotope metallic oxides was confirmed by Transmission Electron Microscopy (TEM, Energy Dispersive X-ray Spectrometry (EDS, X-ray Diffraction (XRD analysis, and gamma spectroscopy analysis. The synthesized nanostructured radioisotope metallic oxides may be used as radiotracers in scientific, environmental, engineering, and industrial fields.

  7. Comparison of biological properties of 99mTc-labeled cyclic RGD Peptide trimer and dimer useful as SPECT radiotracers for tumor imaging

    International Nuclear Information System (INIS)

    Zhao, Zuo-Quan; Yang, Yong; Fang, Wei; Liu, Shuang

    2016-01-01

    Introduction: This study sought to evaluate a 99m Tc-labeled trimeric cyclic RGD peptide ( 99m Tc-4P-RGD 3 ) as the new radiotracer for tumor imaging. The objective was to compare its biological properties with those of 99m Tc-3P-RGD 2 in the same animal model. Methods: HYNIC-4P-RGD 3 was prepared by reacting 4P-RGD 3 with excess HYNIC-OSu in the presence of diisopropylethylamine. 99m Tc-4P-RGD 3 was prepared using a kit formulation, and evaluated for its tumor-targeting capability and biodistribution properties in the BALB/c nude mice with U87MG human glioma xenografts. Planar and SPECT imaging studies were performed in athymic nude mice with U87MG glioma xenografts. For comparison purpose, 99m Tc-3P-RGD 2 (a α v β 3 -targeted radiotracer currently under clinical evaluation for tumor imaging in cancer patients) was also evaluated in the same animal models. Blocking experiments were used to demonstrate the α v β 3 specificity of 99m Tc-4P-RGD 3 . Results: 99m Tc-4P-RGD 3 was prepared with > 95% RCP and high specific activity (~ 200 GBq/μmol). 99m Tc-4P-RGD 3 and 99m Tc-3P-RGD 2 shared almost identical tumor uptake and similar biodistribution properties. 99m Tc-4P-RGD 3 had higher uptake than 99m Tc-3P-RGD 2 in the intestines and kidneys; but it showed better metabolic stability. The U87MG tumors were clearly visualized by SPECT with excellent contrast with 99m Tc-4P-RGD 3 and 99m Tc-3P-RGD 2 . Conclusion: Increasing peptide multiplicity from 3P-RGD 2 to 4P-RGD 3 offers no advantages with respect to the tumor-targeting capability. 99m Tc-4P-RGD 3 is as good a SPECT radiotracer as 99m Tc-3P-RGD 2 for imaging α v β 3 -positive tumors. -- Graphical abstract: This report presents evaluations of a 99m Tc-labeled cyclic RGD peptide trimer ( 99m Tc-4P-RGD 3 ) as the new SPECT radiotracer for tumor imaging. It was found that 99m Tc-4P-RGD 3 was able to accumulate in the xenografted U87MG tumors with high specificity. Display Omitted

  8. Spin-dependent Nucleon Structure Studies at MIT/Bates

    International Nuclear Information System (INIS)

    Botto, T.

    2005-01-01

    We present preliminary results from recent measurements of the proton, neutron and deuterium electro-magnetic form factors obtained by the BLAST collaboration at the MIT/Bates Linear Accelerator Facility. BLAST (Bates Large Acceptance Spectrometer Toroid) is a large-acceptance multi-purpose detector dedicated to studies of exclusive spin-dependent electron scattering from internal polarized targets. BLAST makes use of stored electron beam currents in excess of 150 mA with a 60-70% polarization. The electron beam is let through a 15 mm diameter, 60 cm long open-ended storage cell which is fed with ultra-pure, high-polarization H1,D1 gas from an Atomic Beam Source. The target polarization can be rapidly reversed between different vector and tensor target states, thus minimizing systematic uncertainties. The target spin can be oriented to any in-plane direction via a set of Helmholtz coils. Target polarizations in the storage cell of up to 80% (vector) and 70% (tensor) have been routinely achieved over a period of several months. Our data on the D-vector(e-vector,e'n) reaction off vector polarized deuterium allow for a unique extraction of the neutron charge form factor G E n . At same time, complementary measurements of G M n , T20 and the spin-dependent nucleon momentum distributions in deuterium are obtained via the D-vector(e-vector,e'), D (e-vector,e'd) and D (e-vector,e'p) reactions. In addition, BLAST data on vector polarized hydrogen will provide novel measurements of the GE/GM form-factor ratio on the proton as well as of the spin-dependent electro-excitation of the Δ(1232) resonance. Such comprehensive program on few body physics is now well underway and preliminary data will be presented

  9. A control study on treatment for benzodiazepine dependence with trazodone

    Directory of Open Access Journals (Sweden)

    ZHANG Hong-ju

    2013-05-01

    Full Text Available Objective To determine the efficacy and safety of trazodone in the treatment of benzodiazepine dependence. Methods Forty insomnia patients who met the Classification and Diagnostic Criteria of Mental Disorders in China Third Edition (CCMD-3 of dependence syndrome due to benzodiazepine were involved in the study. Patients were randomly assigned to trazodone group and placebo group for 3 months. The efficacy were assessed by Withdrawal Symptoms Checklist, Hamilton Anxiety Rating Scale (HAMA and polysomnography (PSG. Adverse events were assessed by Treatment Emergent Symptom Scale (TESS. Results The Withdrawal Symptoms Checklist of trazodone group was significantly lower after 7 d treatment than that of placebo group (P = 0.000, and HAMA score of the trazodone group was also significantly lower after 15 d treatment than that of placebo group (P = 0.000. There were no difference in Withdrawal Symptoms Checklist and HAMA of placebo group before and after treatment. Withdrawal Symptoms Checklist and HAMA of the trazodone group were decreased after treatment (P = 0.000. In comparison with placebo group, sleep parameters of the trazodone, including total sleep time (TST, sleep efficiency (SE, sleep latency (SL and slow wave sleep (SWS time presented improvement after 7 d treatment (P = 0.000, for all. After trazodone treatment, total sleep time, slow wave sleep time, sleep efficiency and sleep latency were improved (P = 0.000, for all. No obvious adverse reaction occurred. There were no significant differences in TESS scores between pre? and post?treatment in both groups (P > 0.05. Conclusion Trazodone is markedly effective and safe in the treatment for benzodiazepine dependence.

  10. Modeling the temperature dependence of thermophysical properties: Study on the effect of temperature dependence for RFA.

    Science.gov (United States)

    Watanabe, Hiroki; Kobayashi, Yo; Hashizume, Makoto; Fujie, Masakatsu G

    2009-01-01

    Radio frequency ablation (RFA) has increasingly been used over the past few years and RFA treatment is minimally invasive for patients. However, it is difficult for operators to control the precise formation of coagulation zones due to inadequate imaging modalities. With this in mind, an ablation system using numerical simulation to analyze the temperature distribution of the organ is needed to overcome this deficiency. The objective of our work is to develop a temperature dependent thermophysical liver model. First, an overview is given of the development of the thermophysical liver model. Second, a simulation to evaluate the effect of temperature dependence of the thermophysical properties of the liver is explained. Finally, the result of the simulation, which indicated that the temperature dependence of thermophysical properties accounts for temperature differences influencing the accuracy of RFA treatment is described.

  11. Scale dependence of acoustic velocities. An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Gotusso, Angelamaria Pillitteri

    2001-06-01

    Reservoir and overburden data (e.g. seismic, sonic log and core data) are collected at different stages of field development, at different scales, and under different measurement conditions. A more precise reservoir characterization could be obtained by combining all the collected data. Reliable data may also be obtained from drill cuttings. This methodology can give data in quasi-real time, it is easily applicable, and cheap. It is then important, to understand the relationship between results obtained from measurements at different scales. In this Thesis acoustic velocities measured at several different laboratory scales are presented. This experimental study was made in order to give the base for the development of a model aiming to use/combine appropriately the data collected at different scales. The two main aspects analyzed are the experimental limitations due to the decrease in sample size and the significance of measurements in relation to material heterogeneities. Plexiglas, an isotropic, non-dispersive artificial material, with no expected scale effect, was used to evaluate the robustness of the measurement techniques. The results emphasize the importance of the wavelength used with respect to the sample length. If the sample length (L) is at least 5 time bigger than wavelength used ({lambda}), then the measured velocities do not depend on sample size. Leca stone, an artificial isotropic material containing spherical grains was used to evaluate the combined effects of technique, heterogeneities and sample length. The ratio between the scale of the heterogeneities and the sample length has to be taken in to account. In this case velocities increase with decreasing sample length when the ratio L/{lambda} is smaller than 10-15 and at the same time the ratio between sample length and grain size is greater than 10. Measurements on natural rocks demonstrate additional influence of grain mineralogy, shape and orientation. Firenzuola sandstone shows scale and

  12. Longitudinal Studies of Angiogenesis in Hormone-Dependent Shionogi Tumors

    Directory of Open Access Journals (Sweden)

    Trevor P. Wade

    2007-07-01

    Full Text Available Vessel size imaging was used to assess changes in the average vessel size of Shionogi tumors throughout the tumor growth cycle. Changes in R2 and R2* relaxivities caused by the injection of a superparamagnetic contrast agent (ferumoxtran-10 were measured using a 2.35-T animal magnetic resonance imaging system, and average vessel size index (VSI was calculated for each stage of tumor progression: growth, regression, and relapse. Statistical analysis using Spearman rank correlation test showed no dependence between vessel size and tumor volume at any stage of the tumor growth cycle. Paired Student's t test was used to assess the statistical significance of the differences in average vessel size for the three stages of the tumor growth cycle. The average VSI for regressing tumors (15.1 ± 6.6 wm was significantly lower than that for growing tumors (35.2 ± 25.5 μm; P < .01. Relapsing tumors also had an average VSI (45.4 ± 41.8 μm higher than that of regressing tumors, although the difference was not statistically significant (P = .067. This study shows that VSI imaging is a viable method for the noninvasive monitoring of angiogenesis during the progression of a Shionogi tumor from androgen dependence to androgen independence.

  13. Investigation of sediment transport and optimization of dredging operations in Indian ports using radiotracer technique

    International Nuclear Information System (INIS)

    Pant, H.J.

    2012-01-01

    India has a long coastline of about 7,515 km and there are twelve major ports situated on the coastline. Out of them, six are situated on the West Coast whereas other six are situated on the East Coast. In addition to this, there are more than 140 minor ports and other marine establishments situated along the coastline. Each port and marine project has a navigation channel and depth of this navigation channel needs to be maintained to a level of at least 12-15 meters for smooth sailing of ships. Sediments continuously move along the coast due to alongshore currents generated by the waves and tides; and get deposited in navigation channels. For maintaining the required depth of the channels, the dredging operation is carried out. throughout the year or as and when required. Development of a new port or harbour also involves huge capital dredging. The dredged sediments generated during maintenance or capital dredging needs to be dumped at a suitable location, so that it does not find its way back to the channel and obstruct sailing of ships. Moreover the selected site should be such that the turn around time of the dredger is kept minimum to economize the dredging operation. In order to meet the above requirements, the knowledge of transport parameters such as the general direction of movement, extent of lateral and longitudinal movement, transport velocity, transport thickness and bed load movement rate is required. Radiotracer techniques are commonly used to investigate sediment transport on seabed and evaluate the suitability of the proposed dumping sites. Scandium-46 (half-life: 84 days, Gamma energies: 0.89 MeV (100%), 1.12 MeV (100%)) in the form of scandium glass powder is the most suitable radiotracer for tracing sediments on seabed. The activity used in an investigation ranges from 75-300 GBq (2-8 Ci). The suitably prepared particulate radiotracer is injected on seabed at the proposed site using a specially designed injection system and its movement is

  14. Study of calculated and measured time dependent delayed neutron yields

    International Nuclear Information System (INIS)

    Waldo, R.W.

    1980-05-01

    Time-dependent delayed neutron emission is of interest in reactor design, reactor dynamics, and nuclear physics studies. The delayed neutrons from neutron-induced fission of 232 U, 237 Np, 238 Pu, 241 Am, /sup 242m/Am, 245 Cm, and 249 Cf were studied for the first time. The delayed neutron emission from 232 Th, 233 U, 235 U, 238 U, 239 Pu, 241 Pu, and 242 Pu were measured as well. The data were used to develop an empirical expression for the total delayed neutron yield. The expression gives accurate results for a large variety of nuclides from 232 Th to 252 Cf. The data measuring the decay of delayed neutrons with time were used to derive another empirical expression predicting the delayed neutron emission with time. It was found that nuclides with similar mass-to-charge ratios have similar decay patterns. Thus the relative decay pattern of one nuclide can be established by any measured nuclide with a similar mass-to-charge ratio. A simple fission product yield model was developed and applied to delayed neutron precursors. It accurately predicts observed yield and decay characteristics. In conclusion, it is possible to not only estimate the total delayed neutron yield for a given nuclide but the time-dependent nature of the delayed neutrons as well. Reactors utilizing recycled fuel or burning actinides are likely to have inventories of fissioning nuclides that have not been studied until now. The delayed neutrons from these nuclides can now be incorporated so that their influence on the stability and control of reactors can be delineated. 8 figures, 39 tables

  15. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging

    Directory of Open Access Journals (Sweden)

    Ahmed Haider

    2016-07-01

    Full Text Available Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well characterized. The cannabinoid receptor type 1 (CB1 is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2 in the brain and spinal cord of healthy individuals are relatively low. However, recent studies demonstrated a CB2 upregulation on activated microglia upon neuroinflammation, an indicator of neurodegeneration. Our research group aims to develop a suitable positron emission tomography (PET tracer to visualize the CB2 receptor in patients suffering from neurodegenerative diseases. Herein we report two novel thiophene-based 11C-labeled PET ligands designated [11C]AAT-015 and [11C]AAT-778. The reference compounds were synthesized using Gewald reaction conditions to obtain the aminothiophene intermediates, followed by amide formation. Saponification of the esters provided their corresponding precursors. Binding affinity studies revealed Ki values of 3.3 ± 0.5 nM (CB2 and 1.0 ± 0.2 µM (CB1 for AAT-015. AAT-778 showed similar Ki values of 4.3 ± 0.7 nM (CB2 and 1.1 ± 0.1 µM (CB1. Radiosynthesis was carried out under basic conditions using [11C]iodomethane as methylating agent. After semi-preparative HPLC purification both radiolabeled compounds were obtained in 99% radiochemical purity and the radiochemical yields ranged from 12 to 37%. Specific activity was between 96 - 449 GBq/µmol for both tracers. In order to demonstrate CB2 specificity of [11C]AAT-015 and [11C]AAT-778, we carried out autoradiography studies using CB2-positive mouse/rat spleen tissues. The obtained results revealed unspecific binding in spleen tissue that was not blocked by an excess of CB2-specific ligand GW402833. For in vivo analysis, [11C]AAT-015 was administered to healthy rats via tail

  16. Sample holder for studying temperature dependent particle guiding

    International Nuclear Information System (INIS)

    Bereczky, R.J.; Toekesi, K.; Kowarik, G.; Aumayr, F.

    2011-01-01

    Complete text of publication follows. The so called guiding effect is a complex process involving the interplay of a large number of charged particles with a solid. Although many research groups joined this field and carried out various experiments with insulator capillaries many details of the interactions are still unknown. We investigated the temperature dependence of the guiding since it opens new possibilities both for a fundamental understanding of the guiding phenomenon and for applications. For the temperature dependent guiding experiments a completely new heatable sample holder was designed. We developed and built such a heatable sample holder to make accurate and reproducible studies of the temperature dependence of the ion guiding effect possible. The target holder (for an exploded view see Fig. 1) consists of two main parts, the front and the back plates. The two plates of the sample holder, which function as an oven, are made of copper. These parts surround the capillary in order to guarantee a uniform temperature along the whole tube. The temperature of the copper parts is monitored by a K-Type thermocouple. Stainless steel coaxial heaters surrounding the oven are used for heating. The heating power up to a few watts is regulated by a PID controller. Cooling of the capillary is achieved by a copper feed-through connected to a liquid nitrogen bath outside the UHV chamber. This solution allows us to change the temperature of the sample from -30 deg C up to 90 deg C. Our experiments with this newly developed temperature regulated capillary holder show that the glass temperature (i.e. conductivity) can be used to control the guiding properties of the glass capillary and adjust the conditions from guiding at room temperature to simple geometrical transmission at elevated temperatures. This holds the promise to investigate the effect of conductivity on particle transport (build-up and removal of charge patches) through capillaries in more details

  17. Mercury methylation and reduction potentials in marine water: An improved methodology using {sup 197}Hg radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Koron, Neza [National Institute of Biology, Marine Biology Station, Fornace 41, 6330 Piran (Slovenia); Bratkic, Arne [Department of Environmental Sciences, ' Jozef Stefan' Institute, Jamova 39, 1000 Ljubljana (Slovenia); Ribeiro Guevara, Sergio, E-mail: ribeiro@cab.cnea.gov.ar [Laboratorio de Analisis por Activacion Neutronica, Centro Atomico Bariloche, Av. Bustillo km 9.5, 8400 Bariloche (Argentina); Vahcic, Mitja; Horvat, Milena [Department of Environmental Sciences, ' Jozef Stefan' Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2012-01-15

    A highly sensitive laboratory methodology for simultaneous determination of methylation and reduction of spiked inorganic mercury (Hg{sup 2+}) in marine water labelled with high specific activity radiotracer ({sup 197}Hg prepared from enriched {sup 196}Hg stable isotope) was developed. A conventional extraction protocol for methylmercury (CH{sub 3}Hg{sup +}) was modified in order to significantly reduce the partitioning of interfering labelled Hg{sup 2+} into the final extract, thus allowing the detection of as little as 0.1% of the Hg{sup 2+} spike transformed to labelled CH{sub 3}Hg{sup +}. The efficiency of the modified CH{sub 3}Hg{sup +} extraction procedure was assessed by radiolabelled CH{sub 3}Hg{sup +} spikes corresponding to concentrations of methylmercury between 0.05 and 4 ng L{sup -1}. The recoveries were 73.0{+-}6.0% and 77.5{+-}3.9% for marine and MilliQ water, respectively. The reduction potential was assessed by purging and trapping the radiolabelled elemental Hg in a permanganate solution. The method allows detection of the reduction of as little as 0.001% of labelled Hg{sup 2+} spiked to natural waters. To our knowledge, the optimised methodology is among the most sensitive available to study the Hg methylation and reduction potential, therefore allowing experiments to be done at spikes close to natural levels (1-10 ng L{sup -1}). - Highlights: Black-Right-Pointing-Pointer Inorganic mercury methylation and reduction in marine water were studied. Black-Right-Pointing-Pointer High specific activity {sup 197}Hg was used to label Hg{sup 2+} spikes at natural levels. Black-Right-Pointing-Pointer Methylmercury extraction had 73% efficiency for 0.05-4 ng L{sup -1} levels. Black-Right-Pointing-Pointer High sensibility to assess methylation potentials, below 0.1% of the spike. Black-Right-Pointing-Pointer High sensibility also for reduction potentials, as low as 0.001% of the spike.

  18. Investigation of hydrodynamic behaviour of a pilot-scale trickle bed reactor packed with hydrophobic and hydrophilic packings using radiotracer technique

    International Nuclear Information System (INIS)

    Rajesh Kumar; Sadhana Mohan; Pant, H.J.; Sharma, V.K.; Mahajani, S.M.

    2012-01-01

    A radiotracer study was carried out in a trickle bed reactor (TBR) independently filled with two different types of packing i.e., hydrophobic and hydrophilic. The study was aimed at to estimate liquid holdup and investigate the dispersion characteristics of liquid phase with both types of packing at different operating conditions. Water and H2 gas were used as aqueous and gas phase, respectively. The liquid and gas flow rates used ranged from 0.83 x 10 -7 -16.67 x 10 -7 m 3 /s and 0-3.33 x 10 -4 m 3 (std)/s, respectively. Residence time distribution (RTD) of liquid phase was measured using 82 Br as radiotracer and about 10 MBq activity was used in each run. Mean residence time (MRT) and holdup of liquid phase were estimated from the measured RTD data. An axial dispersion with exchange model was used to simulate the measured RTD curves and model parameters (Peclet number and MRT) were obtained. At higher liquid flow rates, the TBR behaves as a plug flow reactor, whereas at lower liquid flow rates, the flow was found to be highly dispersed. The results of investigation indicated that the dispersion of liquid phase is higher in case of hydrophobic packing, whereas holdup is higher in case of hydrophilic packing. (author)

  19. In Vivo Imaging of Experimental Melanoma Tumors using the Novel Radiotracer 68Ga-NODAGA-Procainamide (PCA).

    Science.gov (United States)

    Kertész, István; Vida, András; Nagy, Gábor; Emri, Miklós; Farkas, Antal; Kis, Adrienn; Angyal, János; Dénes, Noémi; Szabó, Judit P; Kovács, Tünde; Bai, Péter; Trencsényi, György

    2017-01-01

    The most aggressive form of skin cancer is the malignant melanoma. Because of its high metastatic potential the early detection of primary melanoma tumors and metastases using non-invasive PET imaging determines the outcome of the disease. Previous studies have already shown that benzamide derivatives, such as procainamide (PCA) specifically bind to melanin pigment. The aim of this study was to synthesize and investigate the melanin specificity of the novel 68 Ga-labeled NODAGA-PCA molecule in vitro and in vivo using PET techniques. Procainamide (PCA) was conjugated with NODAGA chelator and was labeled with Ga-68 ( 68 Ga-NODAGA-PCA). The melanin specificity of 68 Ga-NODAGA-PCA was tested in vitro , ex vivo and in vivo using melanotic B16-F10 and amelanotic Melur melanoma cell lines. By subcutaneous and intravenous injection of melanoma cells tumor-bearing mice were prepared, on which biodistribution studies and small animal PET/CT scans were performed for 68 Ga-NODAGA-PCA and 18 FDG tracers. 68 Ga-NODAGA-PCA was produced with high specific activity (14.9±3.9 GBq/µmol) and with excellent radiochemical purity (98%PCA uptake of B16-F10 cells was significantly ( p ≤0.01) higher than Melur cells. Ex vivo biodistribution and in vivo PET/CT studies using subcutaneous and metastatic tumor models showed significantly ( p ≤0.01) higher 68 Ga-NODAGA-PCA uptake in B16-F10 primary tumors and lung metastases in comparison with amelanotic Melur tumors. In experiments where 18 FDG and 68 Ga-NODAGA-PCA uptake of B16-F10 tumors was compared, we found that the tumor-to-muscle (T/M) and tumor-to-lung (T/L) ratios were significantly ( p ≤0.05 and p ≤0.01) higher using 68 Ga-NODAGA-PCA than the 18 FDG accumulation. Our novel radiotracer 68 Ga-NODAGA-PCA showed specific binding to the melanin producing experimental melanoma tumors. Therefore, 68 Ga-NODAGA-PCA is a suitable diagnostic radiotracer for the detection of melanoma tumors and metastases in vivo .

  20. A simple microfluidic platform for rapid and efficient production of the radiotracer [18F]fallypride.

    Science.gov (United States)

    Zhang, Xin; Liu, Fei; Knapp, Karla-Anne; Nickels, Michael L; Manning, H Charles; Bellan, Leon M

    2018-05-01

    Herein, we report the development of a simple, high-throughput and efficient microfluidic system for synthesizing radioactive [18F]fallypride, a PET imaging radiotracer widely used in medical research. The microfluidic chip contains all essential modules required for the synthesis and purification of radioactive fallypride. The radiochemical yield of the tracer is sufficient for multiple animal injections for preclinical imaging studies. To produce the on-chip concentration and purification columns, we employ a simple "trapping" mechanism by inserting rows of square pillars with predefined gaps near the outlet of microchannel. Microspheres with appropriate functionality are suspended in solution and loaded into the microchannels to form columns for radioactivity concentration and product purification. Instead of relying on complicated flow control elements (e.g., micromechanical valves requiring complex external pneumatic actuation), external valves are utilized to control transfer of the reagents between different modules. The on-chip ion exchange column can efficiently capture [18F]fluoride with negligible loss (∼98% trapping efficiency), and subsequently release a burst of concentrated [18F]fluoride to the reaction cavity. A thin layer of PDMS with a small hole in the center facilitates rapid and reliable water evaporation (with the aid of azeotropic distillation and nitrogen flow) while reducing fluoride loss. During the solvent exchange and fluorination reaction, the entire chip is uniformly heated to the desired temperature using a hot plate. All aspects of the [18F]fallypride synthesis were monitored by high-performance liquid chromatography (HPLC) analysis, resulting in labelling efficiency in fluorination reaction ranging from 67-87% (n = 5). Moreover, after isolating unreacted [18F]fluoride, remaining fallypride precursor, and various by-products via an on-chip purification column, the eluted [18F]fallypride is radiochemically pure and of a sufficient

  1. Ibuprofen induces reduction of the proliferation-seeking radiotracer 99mTc-(V)DMSA uptake in severe epithelial breast hyperplasia without atypia.

    Science.gov (United States)

    Papantoniou, Vassilios; Tsaroucha, Angeliki; Valsamaki, Pipitsa; Tsiouris, Spyridon; Sotiropoulou, Evangelia; Karianos, Theodore; Marinopoulos, Spyridon; Fothiadaki, Athina; Sotiropoulou, Maria; Archontaki, Aikaterini; Syrgiannis, Konstantinos; Dimitrakakis, Konstantinos; Antsaklis, Aris

    2010-10-01

    The purpose of this study was to investigate if ibuprofen intake can influence mammary uptake of the proliferation-seeking radiotracer technetium 99m-pentavalent dimercaptosuccinic acid (99mTc-(V)DMSA) in women with severe epithelial and atypical epithelial breast hyperplasia. Eight patients with histologically confirmed severe epithelial breast hyperplasia with (n  =  4) and without atypia (n  =  4) were submitted prospectively to 99mTc-(V)DMSA scintimammography before and after a 4-week course of 400 mg ibuprofen daily oral intake. Lesion to background ratios 60 minutes postinjection were calculated and compared (t-test) before and after ibuprofen administration. Prior to ibuprofen, the patients with severe epithelial hyperplasia displayed a significantly higher 99mTc-(V)DMSA uptake ratio compared to those with atypical epithelial hyperplasia (2.40 ± 0.32 vs 1.67 ± 0.09, respectively; p  =  .003). They also exhibited a more substantial percent decline in tracer uptake postibuprofen compared to women with atypical epithelial hyperplasia (62.0 ± 7.1 vs 15.0 ± 0.2, respectively; p  =  .001). Ibuprofen induces significant uptake reduction of the proliferation-seeking radiotracer 99mTc-(V)DMSA in severe epithelial breast hyperplasia without atypia. This agent could therefore constitute a potential imaging tool for monitoring chemoprophylaxis effectiveness in women at the early stages of malignant transformation.

  2. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  3. Abandonment of nicotine dependence treatment: A cohort study

    Directory of Open Access Journals (Sweden)

    Maritza Muzzi Cardozo Pawlina

    Full Text Available CONTEXT AND OBJECTIVE: Non-adherence to treatment is one of the hindering factors in the process of smoking cessation. This study aimed to compare sociodemographic characteristics, smoking status and motivation among smokers who maintained or abandoned treatment to stop smoking, and to analyze associations between sociodemographic factors and smoking. DESIGN AND SETTING: Cohort study on 216 smokers who were attended at healthcare units in Cuiabá, Mato Grosso. METHODS: The instruments used were the Fagerström, URICA and CAGE questionnaires. Data from the initial evaluation was analyzed using the two-proportion test (α < 0.05. The patients were monitored for six months and those who abandoned treatment were accounted for. Bivariate analysis was conducted, using crude prevalence ratios and 5% significance level (P < 0.05, with abandonment of treatment as the outcome variable. Associations with P < 0.20 were selected for multiple robust Poisson regression (RPa. RESULTS: The abandonment rate was 34.26%. Males and individuals in the 20-39 age group, in employment, with low motivation, with shorter time smoking and lower tobacco intake predominated in the dropout group. In the final model, gender (RPa 1.47; 95% CI: 1.03-2.10 and age group (RPa 3.77; 95% CI: 1.47-9.67 remained associated with abandonment. CONCLUSION: Males and individuals in the 20-39 age group, in employment, with low motivation, with shorter time smoking and lower tobacco intake more frequently abandoned the treatment. Male gender and younger age group were associated with abandonment of nicotine dependence treatment.

  4. Investigation of hydrodynamic behaviour of membranes using radiotracer techniques

    Directory of Open Access Journals (Sweden)

    Zakrzewska-Trznadel G.

    2013-05-01

    Full Text Available The aim of the work was to study membrane devices using short-lived radioisotopes like Ba-137m and Ga-68 as tracers. These radioisotopes were obtained from radionuclide generators: Cs-137/Ba-137m and Ge-68/Ga-68. The first radionuclide, namely Ba-137m with a half-life of 2.55 minutes was applied as a liquid phase tracer for studying hydrodynamic conditions inside the membrane apparatus. The membrane module with ceramic membranes was tested by using Ba-137m. The experiments showed that this radionuclide with a short half-life is a perfect tracer for liquid phase, whereas Ga-68 with longer half-life equal to 68 minutes was considered as a solid phase (bentonite tracer. Ga-68 was used to gain more knowledge about the phenomena occurring in the membrane boundary layer. After kinetic studies of isotope adsorption into the carrier material, the growth rate of the deposit layer as well as deposit's thickness on the flat-sheet membrane were studied. The influence of such process parameters like pressure, linear velocity of liquid and feed concentration on formation of the bentonite layer on the membrane surface was studied.

  5. Evaluation of [11C]metergoline as a PET radiotracer for 5HTR in nonhuman primates

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, J.M.; Hooker, J.M.; Kim, S.W.; Reibel, A.T.; Alexoff, D.; Xu, Y.; Shea, C.

    2010-04-20

    Metergoline, a serotonin receptor antagonist, was labeled with carbon-11 in order to evaluate its pharmacokinetics and distribution in non-human primates using positron emission tomography. [{sup 11}C]Metergoline had moderate brain uptake and exhibited heterogeneous specific binding, which was blocked by pretreatment with metergoline and altanserin throughout the cortex. Non-specific binding and insensitivity to changes in synaptic serotonin limit its potential as a PET radiotracer. However, the characterization of [{sup 11}C]metergoline pharmacokinetics and binding in the brain and peripheral organs using PET improves our understanding of metergoline drug pharmacology.

  6. Determination of the hydrodynamic and morphological parameters of the Luyano River using radiotracer techniques

    International Nuclear Information System (INIS)

    Valcarcel, Lino; Alberro, Nancy; Rodriguez, Maydel; Herrero, Zahily; Borroto, Jorge; Hernandez, Anel; Dominguez, Judith; Derivet, Milagros; Flores, Pedro; Cuesta, Jaime; Griffith, Jose

    2011-01-01

    The hydrodynamic and morphological parameters (the times of travel, velocities and flowrates of the waters, and the average widths, cross sections and depths) in the middle segment of the river Luyano were determined combining the employment of sodium pertechnectate (Na 99m TcO 4 ) as radiotracer with other conventional techniques. The results were used for the calibration of the expanded Streeter and Phelps model of the river. In the work, the methodology and the main results obtained during the journey realized between the second fortnight of March and the first of April 2009 are presented. (Author)

  7. TO THE QUESTION ON THE CHOICE OF RADIOTRACER FOR THE DINAMIC NEPHROSCINTIGRAPHY WITH FUNCTIONAL TESTS

    Directory of Open Access Journals (Sweden)

    D.K. Fomin

    2008-01-01

    Full Text Available The comparison of quality of the images at various stages complex dynamic nephroscintigraphy of the urinary tract received with use of various types of radiotracers. To all patients has been executed dynamic nephroscintigraphy with orthostatic sign and indirect radionuclide cystography, also the analysis of quality of images is lead by a method of expert estimations. It was established, that the best opportunities of a visual estimation of a condition of collective system of kidneys and ureters are provided with application tubular radiotraceres, and for an estimation parenchymatous phases of research — glomerular traceres.Key words: vesicoureteral reflux, secretory function of kidneys, excretory function of kidneys, dinamic scintigraphy, radionuclide cystography.

  8. Accumulation of TC-Methylene Diphosphonate Radiotracer in Rat's ...

    African Journals Online (AJOL)

    (99mTc-MDP), and molybdenum-technetium generator used in the study were prepared and confirmed by the Atomic Energy Organization of. Iran. Animals. Seven healthy Wistar rats ... veins were detected by surgery in standard methods. The radioisotope ... laboratory and on small animals [9-11]. Scintigraphy is one of the ...

  9. Radiotracer investigation of cement raw meal homogenizers. Pt. 2

    International Nuclear Information System (INIS)

    Baranyai, L.

    1983-01-01

    Based on radioisotopic tracer technique a method has been worked out to study the homogenization and segregation processes of cement-industrial raw meal homogenizers. On-site measurements were carried out by this method in some Hungarian cement works to determine the optimal homogenization parameters of operating homogenizers. The motion and distribution of different raw meal fractions traced with 198 Au radioisotope was studied in homogenization processes proceeding with different parameters. In the first part of the publication the change of charge homogenity in time was discussed which had been measured as the resultant of mixing and separating processes. In the second part the parameters and types of homogenizers influencing the efficiency of homogenization have been detailed. (orig.) [de

  10. Radiotracer investigation of cement raw meal homogenizers. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Baranyai, L

    1983-12-01

    Based on radioisotopic tracer technique a method has been worked out to study the homogenization and segregation processes of cement-industrial raw meal homogenizers. On-site measurements were carried out by this method in some Hungarian cement works to determine the optimal homogenization parameters of operating homogenizers. The motion and distribution of different raw meal fractions traced with /sup 198/Au radioisotope was studied in homogenization processes proceeding with different parameters. In the first part of the publication the change of charge homogenity in time was discussed which had been measured as the resultant of mixing and separating processes. In the second part the parameters and types of homogenizers influencing the efficiency of homogenization have been detailed.

  11. Sequence-dependent DNA deformability studied using molecular dynamics simulations.

    Science.gov (United States)

    Fujii, Satoshi; Kono, Hidetoshi; Takenaka, Shigeori; Go, Nobuhiro; Sarai, Akinori

    2007-01-01

    Proteins recognize specific DNA sequences not only through direct contact between amino acids and bases, but also indirectly based on the sequence-dependent conformation and deformability of the DNA (indirect readout). We used molecular dynamics simulations to analyze the sequence-dependent DNA conformations of all 136 possible tetrameric sequences sandwiched between CGCG sequences. The deformability of dimeric steps obtained by the simulations is consistent with that by the crystal structures. The simulation results further showed that the conformation and deformability of the tetramers can highly depend on the flanking base pairs. The conformations of xATx tetramers show the most rigidity and are not affected by the flanking base pairs and the xYRx show by contrast the greatest flexibility and change their conformations depending on the base pairs at both ends, suggesting tetramers with the same central dimer can show different deformabilities. These results suggest that analysis of dimeric steps alone may overlook some conformational features of DNA and provide insight into the mechanism of indirect readout during protein-DNA recognition. Moreover, the sequence dependence of DNA conformation and deformability may be used to estimate the contribution of indirect readout to the specificity of protein-DNA recognition as well as nucleosome positioning and large-scale behavior of nucleic acids.

  12. CO ICE PHOTODESORPTION: A WAVELENGTH-DEPENDENT STUDY

    International Nuclear Information System (INIS)

    Fayolle, Edith C.; Linnartz, Harold; Bertin, Mathieu; Romanzin, Claire; Michaut, Xavier; Fillion, Jean-Hugues; Oeberg, Karin I.

    2011-01-01

    UV-induced photodesorption of ice is a non-thermal evaporation process that can explain the presence of cold molecular gas in a range of interstellar regions. Information on the average UV photodesorption yield of astrophysically important ices exists for broadband UV lamp experiments. UV fields around low-mass pre-main-sequence stars, around shocks and in many other astrophysical environments are however often dominated by discrete atomic and molecular emission lines. It is therefore crucial to consider the wavelength dependence of photodesorption yields and mechanisms. In this work, for the first time, the wavelength-dependent photodesorption of pure CO ice is explored between 90 and 170 nm. The experiments are performed under ultra high vacuum conditions using tunable synchrotron radiation. Ice photodesorption is simultaneously probed by infrared absorption spectroscopy in reflection mode of the ice and by quadrupole mass spectrometry of the gas phase. The experimental results for CO reveal a strong wavelength dependence directly linked to the vibronic transition strengths of CO ice, implying that photodesorption is induced by electronic transition (DIET). The observed dependence on the ice absorption spectra implies relatively low photodesorption yields at 121.6 nm (Lyα), where CO barely absorbs, compared to the high yields found at wavelengths coinciding with transitions into the first electronic state of CO (A 1 Π at 150 nm); the CO photodesorption rates depend strongly on the UV profiles encountered in different star formation environments.

  13. A dependence modelling study of extreme rainfall in Madeira Island

    Science.gov (United States)

    Gouveia-Reis, Délia; Guerreiro Lopes, Luiz; Mendonça, Sandra

    2016-08-01

    The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.

  14. Current Molecular Imaging Positron Emitting Radiotracers in Oncology

    International Nuclear Information System (INIS)

    Zhu, Aizhi; Shim, Hyunsuk

    2011-01-01

    Molecular imaging is one of the fastest growing areas of medical imaging. Positron emission tomography has been widely used in the clinical management of patients with cancer. Nuclear imaging provides biological information at the cellular, subcellular, and molecular level in living subjects with noninvasive procedures. In particular, PET imaging takes advantage of traditional diagnostic imaging techniques and introduces positron emitting probes to determine the expression of indicative molecular targets at different stages of cancer. 18F fluorodeoxyglucose ( 18F FDG), the only FDA approved oncological PET tracer, has been widely utilized in cancer diagnosis, staging, restaging, and even monitoring response to therapy; however, 18F FDG is not a tumor specific PET tracer. Over the last decade, many promising tumor specific PET tracer. Over the last decade, many promising tumor specific PET tracers have been developed and evaluated in preclinical and clinical studies. This review provides an overview of the current non 18F FDG PET tracers in oncology that have been developed based on tumor characteristics such as increased metabolism, hyperproliferation, angiogenesis, hypoxia, apoptosis, and tumor specific antigens and surface receptors

  15. A-dependence study of inclusive phi production

    International Nuclear Information System (INIS)

    Daum, C.; Rijk, G. de; Dijkstra, H.; Hardwick, C.; Hoogland, W.; Tiecke, H.; Wiggers, L.; Boehringer, T.; Bosman, M.; Chabaud, V.; Hyams, B.; Koetz, U.; Weilhammer, P.; Rozanska, M.; Rybicki, K.; Turala, M.; Belau, E.; Hajduk, Z.; Klanner, R.; Luetjens, G.; Lutz, G.; Maenner, W.; Neugebauer, E.; Seebrunner, H.; Stierlin, U.; Waltermann, G.; Wylie, A.; Zeludziewicz, T.; Bailey, R.; Damerell, C.; Gill, S.; Gillman, A.; Watts, S.; Wickens, F.

    1983-10-01

    The mass-number dependence of the inclusive phi-meson cross section is measured using two target materials, beryllium and tantalum, in the kinematic range 0 2 . Parametrizing the cross section with sigma(A) + and p-beams respectively. (Auth.)

  16. Radio-tracing 'without' radioactivity: accelerator mass spectrometry in biomedicine

    International Nuclear Information System (INIS)

    Vogel, J.S.

    2005-01-01

    to study changes in bone remodeling due to illness, diet, or age. The decay of 41 Ca is especially benign because the internal electron capture transfers most of the decay energy to the non-interacting neutrino. The pattern of calcium absorption and equilibration in individuals are remarkably similar among healthy people but are distinctive in some illness. Finally, AMS reduces the radioactive waste generated by an experimental program. The spectrometers are also becoming much smaller and more affordable. At least one major drug company now owns two spectrometers. AMS is becoming a necessary tool in biochemical tracing for environmental, nutritional, and therapeutic research.

  17. Dependence of Substorm Evolution on Solar Wind Condition: Simulation Study

    Science.gov (United States)

    Kamiyoshikawa, N.; Ebihara, Y.; Tanaka, T.

    2017-12-01

    A substorm is one of the remarkable disturbances occurring in the magnetosphere. It is known that the substorm occurs frequently when IMF is southward and solar wind speed is high. However, the physical process to determine substorm scale is not well understood. We reproduced substorms by using global MHD simulation, calculated auroral electrojet (ionospheric Hall current) flowing in the ionosphere to investigate the dependence of substorm evolution on solar wind condition. Solar wind speed of 372.4 km/s and IMF Bz of 5.0 nT were imposed to, obtain the quasi-stationary state of the magnetosphere. Then the solar wind parameters were changed as a step function. For the solar wind speed, we assumed 300 km/s, 500 km/s and 700 km/s. For IMF, we assumed -1.0 nT, -3.0 nT, -5.0 nT, -7.0 nT and -9.0 nT. In total, 15 simulation runs were performed. In order to objectively evaluate the substorm, the onset was identified with the method based on the one proposed by Newell et al. (2011). This method uses the SME index that is an extension of the AE index. In this study, the geomagnetic variation induced by the ionospheric Hall current was obtained every 1 degree from the magnetic latitude 40 degrees to 80 degrees and in every 0.5 hours in the magnetic region direction. The upper and the lower envelopes of the geomagnetic variation are regarded as SMU index and SML index, respectively. The larger the solar wind speed, the larger the southward IMF, the more the onset tends to be faster. This tendency is consistent with the onset occurrence probability indicated by Newell et al. (2016). Moreover, the minimum value of the SML index within 30 minutes from the beginning of the onset tends to decrease with the solar wind speed and the magnitude of the southward IMF. A rapid decrease of the SML index can be explained by a rapid increase in the field-aligned currents flowing in and out of the nightside ionosphere. This means that electromagnetic energies flowing into the ionosphere

  18. Systemic catechol-O-methyl transferase inhibition enables the D{sub 1} agonist radiotracer R-[{sup 11}C]SKF 82957

    Energy Technology Data Exchange (ETDEWEB)

    Palner, Mikael, E-mail: mikael.palner@nru.d [Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen (Denmark); Center for Integrated Molecular Brain Imaging, Rigshospitalet (Denmark); McCormick, Patrick; Parkes, Jun [PET Center, Center for Addiction and Mental Health, Toronto, Ontario (Canada); Knudsen, Gitte M. [Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen (Denmark); Center for Integrated Molecular Brain Imaging, Rigshospitalet (Denmark); Wilson, Alan A. [PET Center, Center for Addiction and Mental Health, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, Ontario (Canada)

    2010-10-15

    Introduction: R-[{sup 11}C]-SKF 82957 is a high-affinity and potent dopamine D{sub 1} receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway, facilitating the use of R-[{sup 11}C]-SKF 82957 to image the high-affinity state of the dopamine D{sub 1} receptor with PET. Methods: R-[{sup 11}C]SKF 82957 was administered to untreated and COMT inhibitor-treated conscious rats, and the radioactive metabolites present in the brain and plasma were quantified by HPLC. Under optimal conditions, cerebral uptake and dopamine D{sub 1} binding of R-[{sup 11}C]SKF 82957 were measured ex vivo. In addition, pharmacological challenges with the receptor antagonist SCH 23390, amphetamine, the dopamine reuptake inhibitor RTI-32 and the dopamine hydroxylase inhibitor {alpha}-methyl-p-tyrosine were performed to study the specificity and sensitivity of R-[{sup 11}C]-SKF 82957 dopamine D{sub 1} binding in COMT-inhibited animals. Results: Treatment with the COMT inhibitor tolcapone was associated with a dose-dependent (EC{sub 90} 5.3{+-}4.3 mg/kg) reduction in the lipophilic metabolite. Tolcapone treatment (20 mg/kg) also resulted in a significant increase in the striatum/cerebellum ratio of R-[{sup 11}C]SKF 82957, from 15 (controls) to 24. Treatment with the dopamine D{sub 1} antagonist SCH 23390 reduced the striatal binding to the levels of the cerebellum, demonstrating a high specificity and selectivity of R-[{sup 11}C]SKF 82957 binding. Conclusions: Pre-treatment with the COMT inhibitor tolcapone inhibits formation of an interfering metabolite of R-[{sup 11}C]SKF 82957. Under such conditions, R-[{sup 11}C]SKF 82957 demonstrates high potential as the first agonist radiotracer for imaging the dopamine D{sub 1} receptor by PET.

  19. Determination of the particle size distribution in a powder using radiotracers

    International Nuclear Information System (INIS)

    Revilla D, R.

    1974-01-01

    To determine experimentally the particle size distribution in a powder the meshed method is generally used. This method has the disadvantage that in the obtained distribution is not observed at detail the fine structure of such distribution. In this work, a method for obtaining the distribution of particle size using radiotracers is presented. In the obtained distribution by this method it is observed with more detail the fine structure of the distribution, comparing with the obtained results by the classical method of meshed. The radiotracer method has major resolution for the experimental determination mentioned. In the chapter 1, it is done a brief analysis about theoretical aspects related with the method. In the first part it is analysed the particle behavior (sedimenting) in a fluid. The second part treats the relating with the radioactivity of an activated material as well as its detection. In the chapter 2, a description of the method is done also the experimental problems to applying to the alumina crystals sample are discussed. In the chapter 3 the obtained results and the mistake calculations in such results are showed. Finally, in the chapter 4 the conclusions and recommendations are given which is possible to obtain better results and improve to those in this work were obtained. (Author)

  20. Employment of the technique of radiotracers for analysis of industrial filters

    International Nuclear Information System (INIS)

    Ramos, Vitor Santos; Crispim, Verginia Reis

    2007-01-01

    The main aim of this work is to develop a methodology to evaluate the characteristics of porous media in filter using the radio-tracing technique. To do this, an experimental prototype filter made up of an acrylic cylinder, vertically mounted and supported on the lower side by a controlled leaking valve was developed. Two filters (spheres of acrylic and silica crystals) were used to check the movement of the water through the porous media using 123 I in its MIBG (iodine-123-meta-iodo benzyl-guanidine) form. Further up the filter an instantaneous injection of the substance makes it possible to see the passage of radioactive clouds through the two scintillatory detectors NaI (2x2) ' ' positioned before and immediately after the cylinder with the filtering element (porous media). The are caused by the detectors on the passage of the radioactive cloud are analyzed through statistical functions using the weighted moment method which makes it possible to calculate the Residence-Time (the amount of time the tracer takes to thoroughly pass through the filter) per the equation of dispersion in tubular flow and the one-directional flow of the radiotracer in the porous media. (author)

  1. Evaluation of radiotracers for the detection of atherosclerotic vulnerable plaque and myocardial angiogenesis

    International Nuclear Information System (INIS)

    Dimastromatteo, Julien

    2010-01-01

    Cardiovascular diseases are the leading cause of mortality worldwide. Coronary events are mainly caused by coronary plaque rupture or erosion. However, at present, there is no noninvasive tool available for the detection of vulnerable plaques. The first part of thesis is about evaluation of new radiotracers for the detection of atherosclerotic vulnerable plaques. 99m Tc-B2702p, 20 derivatives, 99m Tc-VP and 99m Tc-VINP28 were evaluated in an experimental model of atherosclerosis (ApoE-/- mice with left carotid artery ligation). 99m Tc- B2702p1 is a potentially useful radiotracer for the in vivo molecular imaging of VCAM-1 expression in atherosclerotic plaques. Myocardial angiogenesis is an important post infarction phenomenon. Angiogenic therapy improves experimentally cardiac parameters. However, clinical trials using the same therapy are more controversial. At present, clinical imaging tools don't allow us to assess angiogenesis therapy. The second part of thesis is about validation of 99m Tc-RAFT-RGD in the detection of myocardial angiogenesis. 99m Tc-RAFT-RGD allow us to perform noninvasive molecular imaging of myocardial angiogenesis in an experimental model. (author)

  2. Investigation of leaching of an antifouling agent from marine paint formulations using radiotracer technique

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Gursharan Singh; Kalgutkar, D.B.; Patil, S.P.; Jayachandran, N.; Unni, V.K.P.

    2012-01-01

    A radiotracer technique was used to investigate the leaching of an antifouling agent from different marine paint formulations with an objective to select the best paint formulation for bulk production. The antifouling agent (Diuron) itself was labeled with carbon-14 (half-life: 5,730 years, β-energy: 156 keV) and used as a radiotracer. The different paint formulations added with radiolabeled Diuron were applied onto suitably selected substrates and measured for initial intensity of β-radiation using a Geiger-Muller detector connected to a ratemeter. The painted substrates were subjected to shower tests for a pre-decided time and subsequently measured for β-radiations. The comparison of intensity of β-radiations in substrates prior and post shower tests provides information about leaching of antifouling agent Diuron from the paint formulation. The high leaching percentage of antifouling agent Diuron post shower tests indicates non-suitability of paint formulation for marine and civil structures. However, low leaching rate of Diuron will make a paint formulation more efficient and suitable. Based on the results of investigation, a paint formulation with minimum leaching rate was identified and selected for bulk production by a paint company. (author)

  3. Development of gold nanoparticle radiotracers for investigating multiphase system in process industries

    International Nuclear Information System (INIS)

    Mohd Amirul Syafiq Mohd Yunos; Jaafar Abdullah; Engku Fahmi Engku Chik; Noraishah Othman

    2010-01-01

    This paper describes the development of colloidal 197 Au-SiO 2 with core-shell structure nanoparticle radiotracers. Using conventional citrate-reduction method, gold nanoparticles were prepared from its corresponding metal salts in aqueous solution then coated with uniform shells of amorphous silica via a sol-gel reaction. This target material of radiotracer application used to investigate multiphase system in process industries without disturbing the system operation. The citrate-reduction-based method provides gold nanoparticles with higher concentration and narrow size distribution. By using transmission electron microscopy (TEM), the resultant of particle size and silica coatings could be varied from tens to several hundred of nanometers by controlling the catalyzer and precipitation time. 197 Au-SiO 2 core-shell nano structure is good to prevent the particles from getting conglomerate resulting in a big mass. In addition, silica surface offer very good chances that make the hydrophobicity behavior on the gold nanoparticles. EDXRF spectrum has proven that 197 Au-SiO 2 core-shell nanoparticles sample consists purely of a gold and silica particles. (author)

  4. Synthesis of n. c. a. PET-radiotracers with carbon-11. Zur Synthese traegerarme PET-Radiotracer mit Kohlenstoff-11

    Energy Technology Data Exchange (ETDEWEB)

    Schirbel, A.

    1998-11-01

    Carbon-11 offers the unique possibility of authentic labelling of molecules as radioindicators for non invasive and quantitative determination of physiological functions via positron emission tomography (PET). Therefore, the goal of this thesis was to synthesize of different n.c.a. [sup 11]C-labelled pharmaceuticals for in vivo distribution studies with PET. For the determination of the pharmacokinetics of [1-[sup 11]C]acetate in porcine myocardium during prolonged ischemia, n.c.a. [1-[sup 11]C]acetate was synthesized via carboxylation of methylmagnesium bromide with in target produced n.c.a. [[sup 11]C]CO[sub 2] with a radiochemical yield (RCY) of 68 [+-] 7%. The fast (18 min) and reliable radiosynthesis allowed for repeated tracer administration at short intervals (<20 min). In order to study the pharmacokinetics and metabolism of acetylsalicylic acid (Aspirin[sup R]c) in humans, [1-[sup 11]C]acetylsalicylic acid, acetyl-[carboxy-[sup 11]C]salicylic acid and [carboxy-[sup 11]C]salicylic acid were prepared. N.c.a. [1-[sup 11]C]acetylsalicylic acid was synthesized via the reaction of [1-[sup 11]C]acetylchloride with salicylic acid salts. The use of the silver salt proved to be superior to the sodium salt and resulted in radiochemical yields of 32 [+-] 5%. Base-line (clean) separation of the labelled product was achieved using radio-HPLC. With regard to the preparation of n.c.a. [carboxy-[sup 11]C]salicylic acid, several protected and unprotected phenol derivates were metallated and subsequently carboxylated using n.c.a. [[sup 11]C]CO[sub 2]. Best results (87 [+-] 3% RCY) could be achieved with 2-(methoxymethoxy)-phenylmagnesium iodide as a precursor and subsequent quantitative cleavage of the MOM-group. Acetylation of n.c.a. [carboxy-[sup 11]C]salicylic acid to acetyl-[carboxy-[sup 11]C]salicylic acid was performed using acetylchloride in CH[sub 2]Cl[sub 2] with a radiochemical yield of 65 [+-] 4%. (orig.)

  5. Predicting the transition from frequent cannabis use to cannabis dependence: a three-year prospective study.

    NARCIS (Netherlands)

    van der Pol, P.; Liebregts, N.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.

    2013-01-01

    Background Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent

  6. Predicting the transition from frequent cannabis use to cannabis dependence: a three-year prospective study

    NARCIS (Netherlands)

    van der Pol, Peggy; Liebregts, Nienke; de Graaf, Ron; Korf, Dirk J.; van den Brink, Wim; van Laar, Margriet

    2013-01-01

    Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent cannabis users. A

  7. Prescription Pain Reliever Abuse and Dependence among Adolescents: A Nationally Representative Study

    Science.gov (United States)

    Wu, Li-Tzy; Ringwalt, Christopher L.; Mannelli, Paolo; Patkar, Ashwin A.

    2008-01-01

    The study investigates the prevalence, patterns, and correlates of adolescents' abuse, sub-threshold dependence, and dependence on prescription pain relievers (PPRs) in a nationally representative sample. Results show dependence on PPRs can take place without abuse and that sub-threshold dependence could have implications for major diagnostic…

  8. Studies in the renormalization-prescription dependence of perturbative calculations

    International Nuclear Information System (INIS)

    Celmaster, W.; Sivers, D.

    1981-01-01

    Now that the quantitative testing of perturbative quantum chromodynamics (QCD) has become a major experimental and theoretical effort, it is important to understand the renormalization-prescription dependence of perturbative calculations. We stress the phenomenological importance of finding a definition of the QCD expansion parameter which reduces the magnitude of high-order corrections. We give explicit arguments suggesting that a choice of coupling based on momentum-space subtraction can be phenomenologically useful. Examples from QCD and QED are used to illustrate these arguments, and we also discuss possibilities for refining them

  9. Experimental study of angular dependence in double photon Compton scattering

    International Nuclear Information System (INIS)

    Sandhu, B.S.; Dewan, R.; Saddi, M.B.; Singh, B.; Ghumman, B.S.

    2000-01-01

    The collision differential cross-section and energy of one of the final photons for double photon Compton scattering have been measured as a function of scattering angle θ 1 . The incident photon energy is 0.662 MeV and thin aluminium foils are used as a scatterer. The two simultaneously emitted photons in this higher order process are detected in coincidence using two NaI(Tl) scintillation spectrometers and 30 ns timing electronics. The measured values for energy and collision differential cross-section agree with theory within experimental estimated error. The present data provide information of angular dependence in this higher order process

  10. Investigation of flow behaviour of coal particles in a pilot-scale fluidized bed gasifier (FBG) using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Kamudu, M Vidya; Prakash, S G; Krishanamoorthy, S; Anandam, G; Rao, P Seshubabu; Ramani, N V S; Singh, Gursharan; Sonde, R R

    2009-09-01

    Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process.

  11. Non-destructive investigation of technical plants and processes and natural processes by short-lived radionuclides (radiotracer)

    International Nuclear Information System (INIS)

    Jentsch, Thorsten; Zeuner, Albert

    2009-01-01

    Short lived open radionuclides are very suitable to investigate transport and mixing processes. They do not pollute the product. After decay of the radionuclide, the product can be used without any restrictions. Examples are showed for technical processes investigation by aid of radiotracer. (orig.)

  12. Study of Time-Dependent Properties of Thermoplastics

    Directory of Open Access Journals (Sweden)

    Bolchoun A.

    2010-06-01

    Full Text Available Simple tests carried out with a common tension/compression testing machine are used to obtain timedependent properties of non-reinforced thermoplastics. These tests include ramp loadings as well as relaxation and creep tests. Two materials (PBT Celanex 2002-2 and POM Hostaform C9021, Ticona GmbH, Kelsterbach were taken for the experiments. The experiments show that an adequate description of the long-term material properties can be obtained from the short-time tests, namely from tests with constant traverse speed $L^.$. Below a model for the time-dependent mechanical behavior is presented and fitted to the obtained measured data. For the evaluation of the fitting quality long-term tests are used. Especially creep and relaxation tests with ”jumps”, i.e. rapid change of loading, are important for this purpose.

  13. History-dependent friction and slow slip from time-dependent microscopic junction laws studied in a statistical framework.

    Science.gov (United States)

    Thøgersen, Kjetil; Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Malthe-Sørenssen, Anders; Scheibert, Julien

    2014-05-01

    To study how macroscopic friction phenomena originate from microscopic junction laws, we introduce a general statistical framework describing the collective behavior of a large number of individual microjunctions forming a macroscopic frictional interface. Each microjunction can switch in time between two states: a pinned state characterized by a displacement-dependent force and a slipping state characterized by a time-dependent force. Instead of tracking each microjunction individually, the state of the interface is described by two coupled distributions for (i) the stretching of pinned junctions and (ii) the time spent in the slipping state. This framework allows for a whole family of microjunction behavior laws, and we show how it represents an overarching structure for many existing models found in the friction literature. We then use this framework to pinpoint the effects of the time scale that controls the duration of the slipping state. First, we show that the model reproduces a series of friction phenomena already observed experimentally. The macroscopic steady-state friction force is velocity dependent, either monotonic (strengthening or weakening) or nonmonotonic (weakening-strengthening), depending on the microscopic behavior of individual junctions. In addition, slow slip, which has been reported in a wide variety of systems, spontaneously occurs in the model if the friction contribution from junctions in the slipping state is time weakening. Next, we show that the model predicts a nontrivial history dependence of the macroscopic static friction force. In particular, the static friction coefficient at the onset of sliding is shown to increase with increasing deceleration during the final phases of the preceding sliding event. We suggest that this form of history dependence of static friction should be investigated in experiments, and we provide the acceleration range in which this effect is expected to be experimentally observable.

  14. A multiwell platform for studying stiffness-dependent cell biology.

    Science.gov (United States)

    Mih, Justin D; Sharif, Asma S; Liu, Fei; Marinkovic, Aleksandar; Symer, Matthew M; Tschumperlin, Daniel J

    2011-01-01

    Adherent cells are typically cultured on rigid substrates that are orders of magnitude stiffer than their tissue of origin. Here, we describe a method to rapidly fabricate 96 and 384 well platforms for routine screening of cells in tissue-relevant stiffness contexts. Briefly, polyacrylamide (PA) hydrogels are cast in glass-bottom plates, functionalized with collagen, and sterilized for cell culture. The Young's modulus of each substrate can be specified from 0.3 to 55 kPa, with collagen surface density held constant over the stiffness range. Using automated fluorescence microscopy, we captured the morphological variations of 7 cell types cultured across a physiological range of stiffness within a 384 well plate. We performed assays of cell number, proliferation, and apoptosis in 96 wells and resolved distinct profiles of cell growth as a function of stiffness among primary and immortalized cell lines. We found that the stiffness-dependent growth of normal human lung fibroblasts is largely invariant with collagen density, and that differences in their accumulation are amplified by increasing serum concentration. Further, we performed a screen of 18 bioactive small molecules and identified compounds with enhanced or reduced effects on soft versus rigid substrates, including blebbistatin, which abolished the suppression of lung fibroblast growth at 1 kPa. The ability to deploy PA gels in multiwell plates for high throughput analysis of cells in tissue-relevant environments opens new opportunities for the discovery of cellular responses that operate in specific stiffness regimes.

  15. A multiwell platform for studying stiffness-dependent cell biology.

    Directory of Open Access Journals (Sweden)

    Justin D Mih

    Full Text Available Adherent cells are typically cultured on rigid substrates that are orders of magnitude stiffer than their tissue of origin. Here, we describe a method to rapidly fabricate 96 and 384 well platforms for routine screening of cells in tissue-relevant stiffness contexts. Briefly, polyacrylamide (PA hydrogels are cast in glass-bottom plates, functionalized with collagen, and sterilized for cell culture. The Young's modulus of each substrate can be specified from 0.3 to 55 kPa, with collagen surface density held constant over the stiffness range. Using automated fluorescence microscopy, we captured the morphological variations of 7 cell types cultured across a physiological range of stiffness within a 384 well plate. We performed assays of cell number, proliferation, and apoptosis in 96 wells and resolved distinct profiles of cell growth as a function of stiffness among primary and immortalized cell lines. We found that the stiffness-dependent growth of normal human lung fibroblasts is largely invariant with collagen density, and that differences in their accumulation are amplified by increasing serum concentration. Further, we performed a screen of 18 bioactive small molecules and identified compounds with enhanced or reduced effects on soft versus rigid substrates, including blebbistatin, which abolished the suppression of lung fibroblast growth at 1 kPa. The ability to deploy PA gels in multiwell plates for high throughput analysis of cells in tissue-relevant environments opens new opportunities for the discovery of cellular responses that operate in specific stiffness regimes.

  16. Social policy and drug dependence: an historical case study.

    Science.gov (United States)

    Smart, C

    1985-11-01

    A detailed examination is presented of the background to the reports and policy developments concerning drug dependence which emerged in Britain during the 1960s. Analysis of documents and interviews with policy makers, officials and doctors involved in the events of the period, reveal that explanatory models in terms of 'moral panic' or 'power struggle' tend to oversimplify the complex processes involved. The role in policy formation of the media, government departments and groups within the medical profession is considered. The patterns of conflict and convergence are seen to overlap simple lines of 'interest'--we find conflict within the medical profession, convergence between the Home Office (legal) and elements of the medical professions (medical). The resulting legal and institutional framework involved only loose guidelines from the centre about treatment, and the shape of policy was determined by individual doctors in the new hospital treatment centres. The apparent re-run of the 1960s being staged in the 1980s will require detailed research in the future in order to avoid superficial comparisons.

  17. Radiotracers for the in vivo PET imagine of acetylcholinesterase in the brain

    International Nuclear Information System (INIS)

    Kilbourn, M.R.; Snyder, S.E.; Nguyen, T.; Koeppe, R.A.; Frey, K.A.; Kuhl, D.E.

    1997-01-01

    Regional brain pharmacokinetics of the piperidinyl esters have been determined in the primate brain, using Positron Emission Tomographic (PET) imaging. The propionate ester shows a faster and more complete rate of hydrolysis in regions of AChE, such as the striatum and the cortex. Regional hydrolysis rates (combined forward rate constants, k3) for these radiotracers can be calculated using a simplified analysis of tissue-time activity curves, without a need for determining metabolite-corrected plasma levels. In the striatum of the monkey, the propionate ester shows a reaction rate with the enzyme that is almost two-fold faster than the isobutyrate ester. These radiolabeled esters form a new approach to the measurement of in vivo function of AChE in the mammalian brain, including humans, and provide a method to assess changes in such enzyme activity as a result of disease or pharmacological intervention

  18. Determination of the filtration velocities and mean velocity in ground waters using radiotracers

    International Nuclear Information System (INIS)

    Duran P, Oscar; Diaz V, Francisco; Heresi M, Nelida

    1994-01-01

    An experimental method to determine filtration, or, Darcy velocity and mean velocity in underground waters using radiotracers, is described. After selecting the most appropriate tracers, from 6 chemical compounds, to measure water velocity, a method to measure filtration velocity was developed. By fully labelling the water column with 2 radioisotopes, Br and tritium, almost identical values were obtained for the aquifer filtration velocity in the sounding S1. This value was 0.04 m/d. Field porosity was calculated at 11% and mean velocity at 0.37 m.d. With the filtration velocity value and knowing the hydraulic variation between the soundings S1 and S2 placed at 10 meters, field permeability was estimated at 2.4 x 10 m/s. (author)

  19. Radiotracers for the in vivo PET imagine of acetylcholinesterase in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Kilbourn, M.R.; Snyder, S.E.; Nguyen, T.; Koeppe, R.A.; Frey, K.A.; Kuhl, D.E. [University of Michigan Medical School, An Arbor (United States). Division of Nuclear Medicine

    1997-10-01

    Regional brain pharmacokinetics of the piperidinyl esters have been determined in the primate brain, using Positron Emission Tomographic (PET) imaging. The propionate ester shows a faster and more complete rate of hydrolysis in regions of AChE, such as the striatum and the cortex. Regional hydrolysis rates (combined forward rate constants, k3) for these radiotracers can be calculated using a simplified analysis of tissue-time activity curves, without a need for determining metabolite-corrected plasma levels. In the striatum of the monkey, the propionate ester shows a reaction rate with the enzyme that is almost two-fold faster than the isobutyrate ester. These radiolabeled esters form a new approach to the measurement of in vivo function of AChE in the mammalian brain, including humans, and provide a method to assess changes in such enzyme activity as a result of disease or pharmacological intervention 10 refs., 5 figs.

  20. Receptor binding radiotracers for the angiotensin II receptor: radioiodinated [Sar1, Ile8]angiotensin II

    International Nuclear Information System (INIS)

    Gibson, R.E.; Beauchamp, H.T.; Fioravanti, C.; Brenner, N.; Burns, H.D.

    1994-01-01

    The potential for imaging the angiotensin II receptor was evaluated using the radioiodinated peptide antagonist [ 125 I][Sar 1 , Ile 8 ]angiotensin II. The radioligand provides a receptor-mediated signal in several tissues in rat (kidneys, adrenal and liver). The receptor-mediated signal of 3% ID/g kidney cortex should be sufficient to permit imaging, at least via SPECT. The radiotracer is sensitive to reductions in receptor concentration and can be used to define in vivo dose-occupancy curves of angiotensin II receptor ligands. Receptor-mediated images of [ 123 I][Sar 1 , Ile 8 ]angiotensin II were obtained in the rat kidney and Rhesus monkey liver. (author)

  1. Advanced CFD and radiotracer techniques - A complementary technology - for industrial multiphase applications

    International Nuclear Information System (INIS)

    Tu, J.Y.

    2004-01-01

    A CFD and RTD Education Package was developed, in which lecture notes, tutorials and computer softwares for both CFD and RTD are included. A user-friendly web-based interface has been prepared to allow lecturers more effectively conducting their training courses or workshops, and to provide students or users more easily learning the CFD and RTD knowledge and practising computer softwares. This report gives an overview of the advances in development and use of CFD models and codes for industrial, particularly multiphase processing applications. Experimental needs for validation and improvement of CFD models and softwares are highlighted. Integration of advanced CFD modelling with radiotracer techniques as a complementary technology for future research and industrial applications is discussed. The features and examples of the developed CFD and RTD Education package are presented. (author)

  2. Radiotracer investigations of the shaft processes in Polish zinc and lead metallurgy. 2

    International Nuclear Information System (INIS)

    Michalik, J.S.; Bazaniak, Z.; Palige, J.

    1990-01-01

    The conditions and the physico-chemical processes occurring in the ISP furnace cause the possibility of partial reoxidation of vapourized zinc escaping from the furnace counter-current to the batch material. In order to determine the reoxidation degree and localize the active zone the radiotracer method was applied. The method of solving the convolution integral was used. The experimental part resulted indetermination of impulse characteristics of the zinc condenser; in the next step, the curves of zinc concentration distribution at the ISP furnace outlet were found by calculations. 65 Zn was used as tracer for the industrial experiments. About 25-30% of total amount of zinc obtained as a result of zinc oxides reduction processes undergoes reoxidation in the surface layer of the bath in the furnace shaft. The method of tracer preparation for investigating the behaviour of zinc occurring in the form of silicates and ferrates in the shaft has been proposed. (author)

  3. Radioiodinated 2-hydroxy-3-(4-iodophenyl)-1-(4-phenylpiperidinyl)propane: potential radiotracer for mapping central cholinergic innervation in vivo

    International Nuclear Information System (INIS)

    Efange, S.M.N.; Dutta, A.K.; Michelson, R.H.; Thomas, J.R.; Boudreau, R.J.; Kung, H.F.; Billings, J.

    1992-01-01

    Radioiodinated 2-hydroxy-3-(4-iodophenyl)-1-(4-phenylpiperidinyl)propane, (4-HIPP), was synthesized and evaluated as a simple vesamicol-like radiotracer for mapping cholinergic pathways in the brain. Both enantiomers of 4-HIPP exhibit significant accumulation (approx. 2% of injected dose) and prolonged retention (t 1/2 > 3h) within the rat brain. The accumulation of radioiodinated 4-HIPP in the rat brain was reduced by up to 70% in the presence of vesamicol and its analogs. The levorotary isomer (-)-4-[ 123 I]HIPP exhibits significant accumulation in the monkey brain, with a half-life of about 9 h. Radioiodinated 4-HIPP may therefore be a useful tool for studying cholinergic pathways in the brain. (author)

  4. Technetium-99 behavior in the terrestrial environment. Field observations and radiotracer experiments

    International Nuclear Information System (INIS)

    Tagami, Keiko

    2003-01-01

    Obtaining data on 99 Tc in the rice paddy field environment is important because Tc is a redox sensitive element. The behavior of Tc is expected to be different under upland field and rice paddy field conditions since the redox conditions in the soil environment differ. However, most of the data on the nuclide behavior in soil were obtained under upland field conditions. To understand the global fallout 99 Tc distributions in soil samples collected in Japan, a simple and rapid separation method was developed in order to determine low-levels of 99 Tc in soil samples by an inductively coupled plasma mass spectrometry. Also, radiotracer experiments using soils under aerobic and anaerobic conditions were carried out to clarify the Tc behavior under paddy field conditions. The results of determination of global fallout 99 Tc in Japanese soils indicated that the radionuclide had been accumulating in rice paddy fields. The mechanisms can be explained by the immobilization of Tc in soil under anaerobic conditions. From the radiotracer experiments, it was clear that under waterlogged conditions, the highly mobile TcO 4 - in soil was readily changed to other immobilized forms, such as TcO 2 , TcS 2 and organically bound forms. To this immobilization, the microbial activity seemed to have an important role in Tc sorption reactions. When the soil, which was once kept in anaerobic conditions, was air-dried again and kept in aerobic conditions, the chemical forms of immobilized Tc did not change remarkably. Interestingly, the similar Tc behavior was observed in a real wet forest near the Chernobyl Reactor. (author)

  5. SPECT imaging with the serotonin transporter radiotracer [{sup 123}I]p ZIENT in nonhuman primate brain

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, Kelly P., E-mail: kelly.cosgrove@yale.ed [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Staley, Julie K.; Baldwin, Ronald M.; Bois, Frederic [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Plisson, Christophe [Emory University School of Medicine, Atlanta, GA 30322 (United States); Al-Tikriti, Mohammed S. [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Seibyl, John P. [Institute for Neurodegenerative Disorders, New Haven, CT 06510 (United States); Goodman, Mark M. [Emory University School of Medicine, Atlanta, GA 30322 (United States); Tamagnan, Gilles D. [Yale University School of Medicine, VA Connecticut HCS (116A6), West Haven, CT 06516 (United States); Institute for Neurodegenerative Disorders, New Haven, CT 06510 (United States)

    2010-07-15

    Introduction: Serotonin dysfunction has been linked to a variety of psychiatric diseases; however, an adequate SPECT radioligand to probe the serotonin transporter system has not been successfully developed. The purpose of this study was to characterize and determine the in vivo selectivity of iodine-123-labeled 2{beta}-carbomethoxy-3{beta}-(4'-((Z)-2-iodoethenyl)phenyl)nortropane, [{sup 123}I]p ZIENT, in nonhuman primate brain. Methods: Two ovariohysterectomized female baboons participated in nine studies (one bolus and eight bolus to constant infusion at a ratio of 9.0 h) to evaluate [{sup 123}I]p ZIENT. To evaluate the selectivity of [{sup 123}I]p ZIENT, the serotonin transporter blockers fenfluramine (1.5, 2.5 mg/kg) and citalopram (5 mg/kg), the dopamine transporter blocker methylphenidate (0.5 mg/kg) and the norepinephrine transporter blocker nisoxetine (1 mg/kg) were given at 8 h post-radiotracer injection. Results: In the bolus to constant infusion studies, equilibrium was established by 4-8 h. [{sup 123}I]p ZIENT was 93% and 90% protein bound in the two baboons and there was no detection of lipophilic radiolabeled metabolites entering the brain. In the high-density serotonin transporter regions (diencephalon and brainstem), fenfluramine and citalopram resulted in 35-71% and 129-151% displacement, respectively, whereas methylphenidate and nisoxetine did not produce significant changes (<10%). Conclusion: These findings suggest that [{sup 123}I]p ZIENT is a favorable compound for in vivo SPECT imaging of serotonin transporters with negligible binding to norepinephrine and dopamine transporters.

  6. Investigation of sorption of Hg(II) ions onto coconut husk from aqueous solution using radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Hasany, S.M.; Ahmad, R.; Chaudhary, M.H. [Nuclear Chemistry Div., Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan)

    2003-07-01

    The sorption of Hg(II) ions onto coconut (Cocos nucifera) husk has been studied using radiotracer technique. Maximum sorption (96%) of Hg(II) ions (7.39 x 10{sup -6} M) onto sorbent surface is achieved from 10{sup -3} M HNO{sub 3} solution in 30 min agitation time using 100 mg of coconut husk. The sorption data follow the Freundlich and Dubinin-Radushkevich (D-R) isotherms. Sorption capacity (6.84{+-}0.45 mmol g{sup -1}) and sorption energy (10.6{+-}0.13 kJ mol{sup -1}) have been evaluated using these isotherms. Among the ions tested to monitor their influence on the sorption, Ba(II), fluoride and tartarate increased the sorption, while thiosulfate, bromide and thiocyanate reduced (< 63 > 26%) the sorption. The cations K(I), Ce(III), Cr(III), Fe(III) and Zr(IV) partially suppressed the sorption. The variation of sorption with temperature yields thermodynamic parameters {delta}H = -37.4{+-}2 kJ mol{sup -1} {delta}S = -105{+-}7 J mol{sup -1} K{sup -1} and {delta}G = -2.58{+-}0.05 kJ mol{sup -1} at 298 K. The negative values of enthalpy and free energy reflect the spontaneous and exothermic nature of sorption, respectively. The selectivity studies of sorbent show that the coconut husk column can be used to separate Hg(II) ions from Se(IV), Zn(II), I(I) and Tc (VII). The sorbent has a potential in radiochemistry to separate gamma energies of {sup 203}Hg (279 keV) from {sup 75}Se (265 and 280 keV). (orig.)

  7. Investigation of sorption of Hg(II) ions onto coconut husk from aqueous solution using radiotracer technique

    International Nuclear Information System (INIS)

    Hasany, S.M.; Ahmad, R.; Chaudhary, M.H.

    2003-01-01

    The sorption of Hg(II) ions onto coconut (Cocos nucifera) husk has been studied using radiotracer technique. Maximum sorption (96%) of Hg(II) ions (7.39 x 10 -6 M) onto sorbent surface is achieved from 10 -3 M HNO 3 solution in 30 min agitation time using 100 mg of coconut husk. The sorption data follow the Freundlich and Dubinin-Radushkevich (D-R) isotherms. Sorption capacity (6.84±0.45 mmol g -1 ) and sorption energy (10.6±0.13 kJ mol -1 ) have been evaluated using these isotherms. Among the ions tested to monitor their influence on the sorption, Ba(II), fluoride and tartarate increased the sorption, while thiosulfate, bromide and thiocyanate reduced ( 26%) the sorption. The cations K(I), Ce(III), Cr(III), Fe(III) and Zr(IV) partially suppressed the sorption. The variation of sorption with temperature yields thermodynamic parameters ΔH = -37.4±2 kJ mol -1 ΔS = -105±7 J mol -1 K -1 and ΔG = -2.58±0.05 kJ mol -1 at 298 K. The negative values of enthalpy and free energy reflect the spontaneous and exothermic nature of sorption, respectively. The selectivity studies of sorbent show that the coconut husk column can be used to separate Hg(II) ions from Se(IV), Zn(II), I(I) and Tc (VII). The sorbent has a potential in radiochemistry to separate gamma energies of 203 Hg (279 keV) from 75 Se (265 and 280 keV). (orig.)

  8. In vivo PET/CT in a human glioblastoma chicken chorioallantoic membrane model: a new tool for oncology and radiotracer development.

    Science.gov (United States)

    Warnock, Geoff; Turtoi, Andrei; Blomme, Arnaud; Bretin, Florian; Bahri, Mohamed Ali; Lemaire, Christian; Libert, Lionel Cyrille; Seret, Alain E J J; Luxen, André; Castronovo, Vincenzo; Plenevaux, Alain R E G

    2013-10-01

    For many years the laboratory mouse has been used as the standard model for in vivo oncology research, particularly in the development of novel PET tracers, but the growth of tumors on chicken chorioallantoic membrane (CAM) provides a more rapid, low cost, and ethically sustainable alternative. For the first time, to our knowledge, we demonstrate the feasibility of in vivo PET and CT imaging in a U87 glioblastoma tumor model on chicken CAM, with the aim of applying this model for screening of novel PET tracers. U87 glioblastoma cells were implanted on the CAM at day 11 after fertilization and imaged at day 18. A small-animal imaging cell was used to maintain incubation and allow anesthesia using isoflurane. Radiotracers were injected directly into the exposed CAM vasculature. Sodium (18)F-fluoride was used to validate the imaging protocol, demonstrating that image-degrading motion can be removed with anesthesia. Tumor glucose metabolism was imaged using (18)F-FDG, and tumor protein synthesis was imaged using 2-(18)F-fluoro-l-tyrosine. Anatomic images were obtained by contrast-enhanced CT, facilitating clear delineation of the tumor, delineation of tracer uptake in tumor versus embryo, and accurate volume measurements. PET imaging of tumor glucose metabolism and protein synthesis was successfully demonstrated in the CAM U87 glioblastoma model. Catheterization of CAM blood vessels facilitated dynamic imaging of glucose metabolism with (18)F-FDG and demonstrated the ability to study PET tracer uptake over time in individual tumors, and CT imaging improved the accuracy of tumor volume measurements. We describe the novel application of PET/CT in the CAM tumor model, with optimization of typical imaging protocols. PET imaging in this valuable tumor model could prove particularly useful for rapid, high-throughput screening of novel radiotracers.

  9. CASE STUDY ON RE-ADJUSTMENTS DEPENDING ON PRICE MODIFICATION

    Directory of Open Access Journals (Sweden)

    Cozma Ighian Diana

    2011-01-01

    Full Text Available Inflationary moments, characterized by significant price rises, have proved that accountingsystems based on historical costs provide a distorted image of the reality: the elements ofthe balance sheet are under-valuated, and the stock-related expenses and amortization in theprofit and loss account are also under-valuated. Under these circumstances, the result isover-valuated, and its distribution leads to allotments from the company’s capital. In thispaper we draw up a case study with regards to the methods used for adjusting pricemodification, clearly outlining, through a comparative analysis, the main differencesbetween the accounting system based on historical cost and inflation accounting.

  10. Water Balance Study of a Groundwater-dependent Oak Forest

    Directory of Open Access Journals (Sweden)

    MÓRICZ, Norbert

    2010-01-01

    Full Text Available The objectives of this study were (1 to estimate the water balance components of an oak standby calibrating a Hydrus 1-D model, (2 to determine the groundwater consumption by the water tablefluctuation method and (3 to compare the results of the modelling with a remote-sensing based estimation.Model simulation described the observed soil moisture and groundwater level relatively well, theroot mean square errors varied between 12.0 and 14.9% for the soil moisture measurements and 5.0%for the groundwater level. Groundwater consumption was estimated also by the water table fluctuationmethod, which provided slightly different groundwater consumption rates than estimated by theHydrus model simulation. The simulated evapotranspiration was compared with results of a remotesensingbased estimation using the surface temperature database of MODIS.According to the Hydrus model, the estimated evapotranspiration resulted from transpiration(73%, interception loss (23% and soil surface evaporation (4% in the two-year study period. Theproportion of groundwater consumption was 58% of the total transpiration. During the dry growingseason of 2007 the groundwater consumption was significant with 66% of the total transpiration.Water supply from groundwater was found to be less important in the wet growing season of 2008with 50%. The remote-sensing based estimation of evapotranspiration was about 4% lower than themodel based results of nearby comparable sites.

  11. Synthesis and in vivo evaluation of novel radiotracers for the in vivo imaging of the norepinephrine transporter

    International Nuclear Information System (INIS)

    Wilson, Alan A.; Patrick Johnson, David; Mozley, David; Hussey, Doug; Ginovart, Nathalie; Nobrega, Jose; Garcia, Armando; Meyer, Jeffery; Houle, Sylvain

    2003-01-01

    The (R,R) and (S,S) enantiomers of 2-[(2-methoxyphenoxy)phenylmethyl]morpholine (MeNER) have been radiolabelled with carbon-11 in good yield and at high specific activity. These radiotracers are close analogues of reboxetine, a potent and selective ligand for the norepinephrine transporter (NET). They were examined as potential ligands for imaging NET in vivo by positron emission tomography (PET). The in vivo brain distribution of both [ 11 C]-labeled enantiomers were evaluated in rats. Following tail-vein injection of the (R,R)-enantiomer regional brain uptake and washout of radioactivity was homogeneous at all time points examined (5-60 min). In contrast, administration of the (S,S)-enantiomer produced a heterogeneous distribution of radioactivity in brain with highest uptake in the hypothalamus, a NET rich region, and lowest uptake in the striatum, a brain region devoid of NET. Hypothalamus to striatum ratios of 2.5 to one were achieved at 60 min post injection of (S,S)-[ 11 C]-MeNER. Pre-injection of the norepinephrine reuptake inhibitors, reboxetine or desipramine, reduced hypothalamus to striatum ratios to near unity while reuptake inhibitors of dopamine and serotonin had no significant effect on binding. In vitro autoradiography studies (rat brain slices) with (S,S)-[ 11 C]-MeNER produced a regional distribution pattern that was consistent with the reported distribution of NET. (S,S)-[ 11 C]-MeNER has the potential to be the first successful PET ligand to image NET

  12. Synthesis and in vivo evaluation of novel radiotracers for the in vivo imaging of the norepinephrine transporter

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Alan A. E-mail: aaw@camhpet.on.ca; Patrick Johnson, David; Mozley, David; Hussey, Doug; Ginovart, Nathalie; Nobrega, Jose; Garcia, Armando; Meyer, Jeffery; Houle, Sylvain

    2003-02-01

    The (R,R) and (S,S) enantiomers of 2-[(2-methoxyphenoxy)phenylmethyl]morpholine (MeNER) have been radiolabelled with carbon-11 in good yield and at high specific activity. These radiotracers are close analogues of reboxetine, a potent and selective ligand for the norepinephrine transporter (NET). They were examined as potential ligands for imaging NET in vivo by positron emission tomography (PET). The in vivo brain distribution of both [{sup 11}C]-labeled enantiomers were evaluated in rats. Following tail-vein injection of the (R,R)-enantiomer regional brain uptake and washout of radioactivity was homogeneous at all time points examined (5-60 min). In contrast, administration of the (S,S)-enantiomer produced a heterogeneous distribution of radioactivity in brain with highest uptake in the hypothalamus, a NET rich region, and lowest uptake in the striatum, a brain region devoid of NET. Hypothalamus to striatum ratios of 2.5 to one were achieved at 60 min post injection of (S,S)-[{sup 11}C]-MeNER. Pre-injection of the norepinephrine reuptake inhibitors, reboxetine or desipramine, reduced hypothalamus to striatum ratios to near unity while reuptake inhibitors of dopamine and serotonin had no significant effect on binding. In vitro autoradiography studies (rat brain slices) with (S,S)-[{sup 11}C]-MeNER produced a regional distribution pattern that was consistent with the reported distribution of NET. (S,S)-[{sup 11}C]-MeNER has the potential to be the first successful PET ligand to image NET.

  13. Optimizing the mercury mass measurement in industrial electrolytic cells by the radio-tracer method at ININ

    International Nuclear Information System (INIS)

    Valle R, J.; Angeles C, A.

    2014-10-01

    One method used in the production of chlorine and sodium is the use of electrolytic cells for the separation of chlorine and sodium from the brine; the industries apply very intense electromagnetic fields in this process. The electrolytic cells use mercury as electrode. In a chlorine production plant inventories are determined by total amount of mercury in the plant annually, since mercury losses are large and a very important parameter is to control the mass of mercury for it is necessary to measure with great precision the losses made. There are several methods to determine the mass of mercury ranging from take samples and weigh, but this involves continuous interruption of the process creating downtimes which in turn represent economic losses giving a result delimiting productivity for the industrial sector. An alternative and attractive method is to use a radioactive tracer whose principle has a similar behavior to study objective. The inert mercury has to be neutron activated in a nuclear reactor to having the characteristics of a tracer; the result makes one of the isotopes of mercury. The tracer is transported taking into account the recommendations of the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexico), then it is injected into the electrolytic cells mixing with the mercury in the system. By a relative radioactivity measurement and one sample by gamma spectrometry per interest cell, the mass of mercury without stopping the process is obtained. For optimal use of radio-tracer method must be taken into account as important features: irradiation time of mercury, counting conditions, vial geometry, sample volume, sample cells, mixing time and half-life of the tracer. (Author)

  14. Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, W R; Watson, G M; DeVan, J H; Evans, R B [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-15

    When Inconel or Inor-8 alloys are exposed to a molten fluoride mixture containing reducible material, chromium is selectively oxidized and removed from the alloy. By the use of radio-tracer Cr{sup 51}, the self-diffusion coefficients for chromium in Inconel and Inor-8 and the applicability of these values to alloys under corrosive conditions have been evaluated. Overall coefficients have been obtained (1) by measuring depletion of Cr{sup 51} (charged as CrF{sub 2}) for non-corrosive fluoride melts in alloy capsules and (2) by comparison of measured total radioactivity of exposed alloy specimens with that of the salt to which they were exposed. In addition, coefficients were obtained from measurement of tracer concentration profiles through successive electropolishings of the specimens. The overall coefficients and those obtained from electropolishing experiments agree very well for Inconel at high temperatures and for Inor-8 at all temperatures. For temperatures below 750{sup o}C, coefficients obtained by electropolishing Inconel specimens are higher than the overall values; the bulk diffusion process is not uniform for this case. In all cases, good agreement was found between the overall diffusion coefficients and those extrapolated from published data at higher temperature with generally similar Cr-Ni alloys. Duplicate, polythermal loops of Inor-8 were used to circulate a non-corrosive fluoride melt containing Cr{sup 51} (as CrF{sub 2}). One of these loops was sacrificed to evaluate take-up of Cr{sup 51} by the alloy; the second was used to circulate a melt containing FeF{sub 2} to obtain measurable removal of Cr from the alloy. Good agreement between observed behaviour and that predicted from the measured diffusion coefficients was obtained; this agreement suggests that the self-diffusion coefficient for Cr is insensitive to changes in chromium content of the Inor-8 alloy. (author) [French] Lorsqu'on soumet les alliages Inconel ou Inor-8 a l'action d'un melange

  15. Radial dependence of foreshock cavities: a case study

    Directory of Open Access Journals (Sweden)

    D. G. Sibeck

    2004-12-01

    Full Text Available We present a case study of Geotail, Interball-1, IMP-8, and Wind observations of density and magnetic field strength cavities excavated by the enhanced pressures associated with bursts of energetic ions in the foreshock. Consistent with theoretical predictions, the pressure of the energetic ions diminishes rapidly with upstream distance due to a decrease in the flux of energetic ions and a transition from near-isotropic to streaming pitch angle distributions. Consequently, the cavities can only be observed immediately upstream from the bow shock. A comparison of conditions upstream from the pre- and post-noon bow shock demonstrates that foreshock cavities introduce perturbations into the oncoming solar wind flow with dimensions smaller than those of the magnetosphere. Dayside geosynchronous magnetic field strength variations observed by GOES-8 do not track the density variations seen by any of the spacecraft upstream from the bow shock in a one-to-one manner, indicating that none of these spacecraft observed the precise sequence of density variations that actually struck the subsolar magnetopause. Key words. Interplanetary physics (energetic particles; planetary bow shocks – Magnetospheric physics (solar wind-magnetosphere interactions

  16. Radial dependence of foreshock cavities: a case study

    Directory of Open Access Journals (Sweden)

    D. G. Sibeck

    2004-12-01

    Full Text Available We present a case study of Geotail, Interball-1, IMP-8, and Wind observations of density and magnetic field strength cavities excavated by the enhanced pressures associated with bursts of energetic ions in the foreshock. Consistent with theoretical predictions, the pressure of the energetic ions diminishes rapidly with upstream distance due to a decrease in the flux of energetic ions and a transition from near-isotropic to streaming pitch angle distributions. Consequently, the cavities can only be observed immediately upstream from the bow shock. A comparison of conditions upstream from the pre- and post-noon bow shock demonstrates that foreshock cavities introduce perturbations into the oncoming solar wind flow with dimensions smaller than those of the magnetosphere. Dayside geosynchronous magnetic field strength variations observed by GOES-8 do not track the density variations seen by any of the spacecraft upstream from the bow shock in a one-to-one manner, indicating that none of these spacecraft observed the precise sequence of density variations that actually struck the subsolar magnetopause.

    Key words. Interplanetary physics (energetic particles; planetary bow shocks – Magnetospheric physics (solar wind-magnetosphere interactions

  17. Development of gamma emitting receptor binding radiotracers for imaging the brain and pancreas. Final technical progress report, March 1, 1988--May 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This document give paragraph synopses of results in research on brain and pancreas imaging, using radiotracers. General catagories of research included chemistry, pharmacology, imaging physics, and kinetic modeling. A list of publications is included

  18. Synthesis and preclinical characterization of 1-(6'-deoxy-6'-[18F]fluoro-β-d-allofuranosyl)-2-nitroimidazole (β-6'-[18F]FAZAL) as a positron emission tomography radiotracer to assess tumor hypoxia.

    Science.gov (United States)

    Wanek, Thomas; Kreis, Katharina; Križková, Petra; Schweifer, Anna; Denk, Christoph; Stanek, Johann; Mairinger, Severin; Filip, Thomas; Sauberer, Michael; Edelhofer, Patricia; Traxl, Alexander; Muchitsch, Viktoria E; Mereiter, Kurt; Hammerschmidt, Friedrich; Cass, Carol E; Damaraju, Vijaya L; Langer, Oliver; Kuntner, Claudia

    2016-11-01

    Positron emission tomography (PET) using fluorine-18 ( 18 F)-labeled 2-nitroimidazole radiotracers has proven useful for assessment of tumor oxygenation. However, the passive diffusion-driven cellular uptake of currently available radiotracers results in slow kinetics and low tumor-to-background ratios. With the aim to develop a compound that is actively transported into cells, 1-(6'-deoxy-6'-[ 18 F]fluoro-β-d-allofuranosyl)-2-nitroimidazole (β-[ 18 F]1), a putative nucleoside transporter substrate, was synthetized by nucleophilic [ 18 F]fluoride substitution of an acetyl protected labeling precursor with a tosylate leaving group (β-6) in a final radiochemical yield of 12±8% (n=10, based on [ 18 F]fluoride starting activity) in a total synthesis time of 60min with a specific activity at end of synthesis of 218±58GBq/μmol (n=10). Both radiolabeling precursor β-6 and unlabeled reference compound β-1 were prepared in multistep syntheses starting from 1,2:5,6-di-O-isopropylidene-α-d-allofuranose. In vitro experiments demonstrated an interaction of β-1 with SLC29A1 and SLC28A1/2/3 nucleoside transporter as well as hypoxia specific retention of β-[ 18 F]1 in tumor cell lines. In biodistribution studies in healthy mice β-[ 18 F]1 showed homogenous tissue distribution and excellent metabolic stability, which was unaffected by tissue oxygenation. PET studies in tumor bearing mice showed tumor-to-muscle ratios of 2.13±0.22 (n=4) at 2h after administration of β-[ 18 F]1. In ex vivo autoradiography experiments β-[ 18 F]1 distribution closely matched staining with the hypoxia marker pimonidazole. In conclusion, β-[ 18 F]1 shows potential as PET hypoxia radiotracer which merits further investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Simpler and More Accurate: Weighing the Mercury in Electrolytic Cells by Radiotracer Dilution Method

    Directory of Open Access Journals (Sweden)

    Sugiharto

    2010-08-01

    Full Text Available Weight of mercury in electrolytic cell of soda industry is usually measured gravimetrically, which is typical labor work in character. Error sources of the gravimetric method might have come from the fact that some mercury’s are usually trapped in the cell due to complicated structure of electrolytic cell. This cause unknown errors. In addition, formation of amalgam at the cathode may cause a further uncertainty in the measurement. Total error from gravimetric method is 4% on average. Radiotracer dilution method provides advantages either for simplification of procedure and reduction of measurement error. In this experiment radioisotope mercury 203Hg, which was prepared in nuclear reactor was used to examine 13 of 14 electrolytic cells of soda plant. Each electrolytic cell was designed containing approximately 700 kg inactive mercury. Before injection, the radioisotope mercury was mixed with non radioisotope mercury in a bath to obtain a suitable injection aliquots and standard references. Calibration curve, which was derived from two stage dilution processes taken from standard references, was used to examine degree of mixing between radioisotope and non radioisotope mercury and it was also used in weight calculation of non radioisotope mercury in electrolytic cell. Injection was carried out simply by pouring the injection aliquots into the flowing mercury at the inlet side of the cell. Mercury samples from the cells were extracted at regular time intervals and filled into vials for counting. This was done for the primary conformation of the completeness of mixing of the tracer with the non radioisotope mercury in each cell. When complete mixing is achieved, the unknown quantity of mercury in each cell was calculated based on mass balance principle. From the calculation the weight of mercury in each electrolytic cell was not the same and maximum error of measurement obtained from this method is 2.48 %. Compared to gravimetrically error

  20. Simpler and More Accurate: Weighing the Mercury in Electrolytic Cells by Radiotracer Dilution Method

    International Nuclear Information System (INIS)

    Sugiharto; Santoso, S.B.; Santoso, G.B.

    2010-01-01

    Weight of mercury in electrolytic cell of soda industry is usually measured gravimetrically, which is typical labor work in character. Error sources of the gravimetric method might have come from the fact that some mercury's are usually trapped in the cell due to complicated structure of electrolytic cell. This cause unknown errors. In addition, formation of amalgam at the cathode may cause a further uncertainty in the measurement. Total error from gravimetric method is 4% on average. Radiotracer dilution method provides advantages either for simplification of procedure and reduction of measurement error. In this experiment radioisotope mercury 203 Hg, which was prepared in nuclear reactor was used to examine 13 of 14 electrolytic cells of soda plant. Each electrolytic cell was designed containing approximately 700 kg inactive mercury. Before injection, the radioisotope mercury was mixed with non radioisotope mercury in a bath to obtain a suitable injection aliquots and standard references. Calibration curve, which was derived from two stage dilution processes taken from standard references, was used to examine degree of mixing between radioisotope and non radioisotope mercury and it was also used in weight calculation of non radioisotope mercury in electrolytic cell. Injection was carried out simply by pouring the injection aliquots into the flowing mercury at the inlet side of the cell. Mercury samples from the cells were extracted at regular time intervals and filled into vials for counting. This was done for the primary conformation of the completeness of mixing of the tracer with the non radioisotope mercury in each cell. When complete mixing is achieved, the unknown quantity of mercury in each cell was calculated based on mass balance principle. From the calculation the weight of mercury in each electrolytic cell was not the same and maximum error of measurement obtained from this method is 2.48 %. Compared to gravimetrically error mentioned above, it was

  1. Semi-automated lab-on-a-chip for dispensing GA-68 radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, Irving [Weinberg Medical Physics LLC, Bethesda, MD (United States)

    2014-03-12

    We solved a technical problem that is hindering American progress in molecular medicine, and restricting US citizens from receiving optimal diagnostic care. Specifically, the project deals with a mother/daughter generator of positron-emitting radiotracers (Ge-68/Ga-68). These generator systems are approved in Europe but cannot be used in the USA, because of safety issues related to possible breakthrough of long-lived Ge-68 (mother) atoms. Europeans have demonstrated abilities of Ga-68-labeled radiotracers to image cancer foci with high sensitivity and specificity, and to use such methods to effectively plan therapy.The USA Food and Drug Administration (FDA) and Nuclear Regulatory Commission (NRC) have taken the position that every patient administration of Ga-68 should be preceded by an assay demonstrated that Ge-68 breakthrough is within acceptable limits. Breakthrough of parent elements is a sensitive subject at the FDA, as evidenced by the recent recall of Rb-82 generators due to inadvertent administrations of Sr-82. Commercially, there is no acceptable rapid method for assaying breakthrough of Ge-68 prior to each human administration. The gamma emissions of daughter Ga-68 have higher energies than the parent Ge-68, so that the shielding assays typically employed for Mo-99/Tc-99m generators cannot be applied to Ga-68 generators. The half-life of Ga-68 is 68 minutes, so that the standard 10-half-life delay (used to assess breakthrough in Sr-82/Rb-82 generators) cannot be applied to Ga-68 generators. As a result of the aforementioned regulatory requirements, Ga-68 generators are sold in the USA for animal use only.The American clinical community’s inability to utilize Ga-68 generators impairs abilities to treat patients domestically, and puts the USA at a disadvantage in developing exportable products. The proposed DOE project aimed to take advantage of recent technological advances developed for lab-on-a-chip (LOC) applications. Based on our experiences

  2. Abnormal gastrointestinal accumulation of radiotracer by gastric bleeding during {sup 99m}Tc-MDP bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kyung A.; Lee, Sang Woo; Lee, Jae Tae; Lee, Kyu Bo [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of)

    1998-06-01

    We present a case in which a patient with acute hemorrhagic gastritis demonstrated abnormal gastrointestinal accumulation of radiotracer during {sup 99m}Tc-methylene diphosphonate (MDP) skeletal scintigraphy. A hemorrhagic gastritis was subsequently demonstrated by endoscopy. The mechanism for the intestinal localization of {sup 99m}Tc-MDP in this patients is not clear, but we guess that the extravasated blood containing the radiopharmaceutical cannot recirculate and stays at the bleeding site, so we can see the intestinal activity.

  3. In Vivo Metabolic Trapping Radiotracers for Imaging Monoamine Oxidase-A and –B Enzymatic Activity

    Science.gov (United States)

    Brooks, Allen F.; Shao, Xia; Quesada, Carole A.; Sherman, Phillip; Scott, Peter J.H.; Kilbourn, Michael R.

    2017-01-01

    The isozymes of monoamine oxidase (MAO-A and MAO-B) are important enzymes involved in the metabolism of numerous biogenic amines, including the neurotransmitters serotonin, dopamine and norepinephrine. Recently, changes in concentrations of MAO-B have been proposed as an in vivo marker of neuroinflammation associated with Alzheimer’s disease. Previous developments of in vivo radiotracers for imaging changes in MAO enzyme expression or activity have utilized the irreversible propargylamine-based suicide inhibitors, or high-affinity reversibly-binding inhibitors. As an alternative approach, we have investigated 1-[11C]methyl-4-aryloxy-1,2,3,6-tetrahydropyridines as metabolic trapping agents for the monoamine oxidases. MAO-mediated oxidation and spontaneous hydrolysis yields 1-[11C]methyl-2,3-dihydro-4-pyridinone as a hydrophilic metabolite that is trapped within brain tissues. Radiotracers with phenyl, biphenyl and 7-coumarinyl ethers were evaluated using microPET imaging in rat and primate brain. No isozyme selectivity for radiotracer trapping was observed in the rat brain for any compound, but in the monkey brain the phenyl ether demonstrated MAO-A selectivity, and the coumarinyl ether showed MAO-B selectivity. These are lead compounds for further development of 1-[11C]methyl-4-aryloxy-1,2,3,6-tetrahydropyridines with optimized brain pharmacokinetics and isozyme selectivity. PMID:26393369

  4. Treatment of system dependencies and human interactions in PRA studies: a review and sensitivity study

    International Nuclear Information System (INIS)

    Orvis, D.D.; Joksimovich, V.; Worledge, D.H.

    1985-01-01

    The Electric Power Research Institute sponsored the review and comparison of five PRA studies: Arkansas Nuclear One - Unit 1, Big Rock Point, Grand Gulf, Limerick, and Zion - Unit 1. The review has been conducted in two phases. The Phase I review may be characterized as a qualitative look into many aspects of a PRA study. The Phase II review was performed to quantify the extent that differences in analytical techniques or key assumptions in these areas affect the differences in study results. In each of the PRA studies reviewed, the general descriptions of analytical approaches and descriptions of the analyses of event tree, fault tree and human interaction analyses that affected the dominant core damage sequences were reviewed. When these descriptions aroused interest because of seeming inconsistencies within the study or with other studies, they were pursued in some depth. The approaches or assumptions were contrasted to similar elements from other studies, and sensitivity analyses were performed in many cases to test the significance of results to the analytical models or assumptions. Inferences were drawn from the results regarding significance of the item to plant-specific results and, where possible, were generalized to other PRAs. This paper describes the results of the review of system dependencies and human interactions

  5. Study of energetic dependence of LiF TLDs for photons

    International Nuclear Information System (INIS)

    Cavalieri, Tassio A.; Antunes, Paula C.G.; Paiva, Fabio; Branco, Isabela S.; Sena, Michelle K.S.; Siqueira, Paulo T.D.; Yoriyaz, Helio

    2015-01-01

    The LiF TLDs are widely used for photon dosimetry. However, in the most case the energetic dependence of these TLDs are not taken into account. This work is a preliminary study of energetic photon dependence in LiF TLD (TLD 700, enriched with 7 Li). For this study it was utilized a methodology already used in others works that seek understand the dependence energetic of TLD. It was utilized three different X-ray spectrum and a 137 Cs source; Beyond the calculus utilized in previous works, it was built the calibration curve for each spectrum to see the difference in dosimetry that the energetic dependence could cause. (author)

  6. Influence of depression and early adverse experiences on illicit drug dependence: a case-control study.

    Science.gov (United States)

    Ferigolo, Maristela; Stein, Airton T; Fuchs, Flavio D; Barros, Helena M T

    2009-06-01

    The purpose of this study was to investigate the association between depression and illicit drug dependence among a Latin-American population. illicit drug dependent patients (n = 137) and controls (n = 274) were interviewed using the Diagnostic Interview for Genetic Studies, in order to detect lifetime and current depressive disorder and illicit (cocaine, cannabis or inhalants) substance dependence. A regression analysis was used to estimate the odds ratio for drug dependence according to the diagnosis of depression. The lifetime diagnosis of depression (p = 0.001; OR = 4.9; 95% CI, 1.9-12.7) predicts illegal drugs dependence. Sociodemographic variables such as male gender (p drug dependence. Additional influent factors detected were having parents (p = 0.006; OR = 18.9; 95% CI, 2.3-158) or friends (p illicit drugs dependents. although a causal relationship between dependence on illicit drugs and depression cannot be determined, comparison of the sequence of events point to the occurrence of depression later in life than dependence. It remains to be determined whether depression is a comorbidity of dependence, sharing etiological factors, or a consequence of drug abuse and/or abstinence.

  7. Radiotracer investigations on dispersion of low level effluents discharged into Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Jacob, Noble; Mendhekar, G.N.; Singh, Sanjay

    2015-01-01

    Two radiotracer investigations (using radioactive 82 Br) were carried out near the CIRUS jetty in the Mumbai Harbour Bay (MHB) to evaluate the dilution and dispersion of low level liquid effluents discharged from the BARC Effluent Treatment Plant (ETP). The first experiment was conducted during an ebb tide while the second was conducted during a flood tide. In both the experiments, about 1.55Ci (57 GBq) of 82 Br was injected into one of the aeration tanks of the ETP. The labelled effluent was discharged into the bay and the movement of the plume in the coastal water was monitored using underwater γ-scintillation detectors. Contour map depicting the spread of the radioactive plume was prepared and dilution factors were estimated. The extent of spread of the tracer was comparatively higher during the ebb tide than in flood tide. A 2-D advection dispersion (analytical) model was used to obtain the system parameters D x and D y (for the ebb tide D x is ∼ 5 m 2 s -1 and D y : 0.7 m 2 s -1 ; for flood tide D x is 5 m 2 s -1 and D y : 0.15 m 2 s -1 ). (author)

  8. Differential zinc uptake of rice genotypes as established by radiotracer technique

    International Nuclear Information System (INIS)

    Sudhalakshmi, C.; Krishnasamy, R.; Meena, S.

    2017-01-01

    Rice is a sensitive crop to zinc (Zn 2+ ) deficiency and its uptake, transport and metabolism is imperative in bio-fortification process. A pot culture experiment was conducted at Tamil Nadu Agricultural University, Coimbatore to establish the differential zinc use efficiency of rice genotypes viz., Zn efficient Norungan and Zn inefficient PMK 3 and to assess the partitioning of Zn in shoot and root of genotypes employing radiotracer technique. Graded levels of Zn (0, 12.5, 25.0, 37.5 and 50 kg ha -1 of ZnSO 4 ) as 65 Zn labeled ZnSO 4 were applied. Zinc uptake from fertilizer increased with increased dose of applied zinc up to 37.5 kg ha -1 for PMK 3 whereas in Norungan, it was up to 25 kg ZnSO 4 ha -1 and thereafter it declined. The per cent zinc derived from fertilizer (% Zndff) was the highest in PMK 3 which apparently implies its inability to mobilize soil nutrient reserve and respond to elevated doses of applied zinc. The % Zndfs was higher in Norungan. In both the genotypes, the 'A value' showed a conspicuous increase with increased dose of applied zinc. Norungan registered a higher 'A value' than PMK 3 irrespective of the stages of sampling. Zn efficient Norungan had better Zn translocation to the shoots whereas in Zn inefficient PMK 3, vacuolar sequestration in root cells was higher. (author)

  9. Process and installation for producing tomographic images of the distribution of a radiotracer

    International Nuclear Information System (INIS)

    Fonroget, Jacques; Brunol, Jean.

    1977-01-01

    The invention particularly concerns a process for obtaining tomographic images of an object formed by a radiotracer distributed spacially over three dimensions. This process, using a detection device with an appreciably plane detection surface and at least one collimation orifice provided in a partition between the detection surface and the object, enables tomographic sections to be obtained with an excellent three-dimensional resolution of the images achieved. It is employed to advantage in an installation that includes a detection device or gamma camera on an appreciably plane surface, a device having a series of collimation apertures which may be used in succession, these holes being appreciably distributed over a common plane parallel to the detection surface, and a holder for the object. This holder can be moved in appreciably parallel translation to the common plane. The aim of this invention is, inter alia, to meet two requirements: localization in space and obtaining good contrasts. This aim is achieved by the fact that at least one tomographic image is obtained from a series of intermediate images of the object [fr

  10. Bioavailability and distribution and of ceria nanoparticles in simulated aquatic ecosystems, quantification with a radiotracer technique

    International Nuclear Information System (INIS)

    Zhang Zhiyong; Zhang Peng; He Xiao; Ma Yuhui; Lu Kai; Zhao Yuliang

    2014-01-01

    Although the presence of manufactured nanoparticles in the aquatic environment is still largely undocumented, their release could certainly occur in the future, particularly via municipal treatment plant effluents of cities supporting nano-industries. To get an initial estimate of the environmental behavior of nanomaterials, we investigated the distribution and accumulation of ceria nanoparticles in simulated aquatic ecosystems which included aquatic plant, shellfish, fish, water, and sediment using a radiotracer technique. Radioactive ceria ( 141 CeO 2 ) nanoparticles with a diameter of ca. 7 nm were synthesized by a precipitation method and added to the simulated aquatic ecosystems. The results indicate that the concentration of ceria nanoparticles in water decreased to a steady-state value after 3 days; meanwhile, the concentrations of ceria nanoparticles in the aquatic plant and sediment increased to their highest values. The distribution and accumulation characteristics of ceria nanoparticles in various aquatic organisms were different. Ceratophyllum demersum showed a high ability of accumulation of ceria nanoparticles from water. (authors)

  11. Reduction of exposure of pet staff by computer-aided injection of radiotracers

    International Nuclear Information System (INIS)

    Balduyck, S.; Sarracanie, M.; Trevisan, L.

    2006-01-01

    Full text of publication follows: Positron Emission Tomograph y (PET) is now widely used, and everyday employment of positron emitters have brought new needs for radiation protection. Analysing the dosimetry of PET staff in the course of medical examinations, it was shown that the injection step is the most irradiating part. The necessity to monitor the safety of the patient during the injection of the radiotracer prevents us from reducing exposure time or to insert a complete shielding between the source and the operator. To lower the dose by increasing the distance, we designed a system based on two syringe pumps: one for the tracer and one for saline solution. Both a re remotely controlled by computer. The exposure of staff during the injection step is thus reduced to the five seconds necessary to place the shielded syringe in the pump. The sequence of injection is fully automatic, but all relevant parameters (such as pressure, volume, flow, occlusion detection, etc...) are continuously monitored and the operator can safely interrupt the sequence at any time. A visual, dialogue-based, interface has been designed to provide a convenient full monitoring service even for non-familiar computer users, without lowering the security of the patient. With this computer-aided injection system, the mean dose of exposure to PET staff was divided by eight. Such a system can be used in all radiopharmaceutical injections encountered in nuclear medicine or radiotherapy facilities, by adapting the injection sequence and the number of syringe pumps. (authors)

  12. Corneal backscatter in insulin-dependent and non-insulin-dependent diabetes mellitus patients: a pilot study

    Directory of Open Access Journals (Sweden)

    Ana M Calvo-Maroto

    Full Text Available ABSTRACT Purpose: To compare central corneal backscatter obtained from Scheimpflug images between patients with insulin-dependent and non-insulin-dependent diabetes mellitus (IDDM and NIDDM, respectively and healthy controls. Methods: Seven patients with IDDM (7 eyes, eleven patients with NIDDM (11 eyes, and sixteen healthy subjects (16 eyes were included in this pilot study. Scheimpflug imaging system (Pentacam, Oculus Inc., Germany was used to obtain optical sections of the cornea. Seven meridians were analyzed for each eye, oriented from 70° to 110°. Optical density values for the central 3-mm and 5-mm zones of the cornea were obtained by image analysis using external software. Results: Corneal backscatter was significantly higher in the diabetic patients than in the controls for the central 3-mm (p=0.016 and 5-mm (p=0.014 zones. No significant differences in corneal backscatter were found between the IDDM and NIDDM groups for either zone (both p>0.05. In the NIDDM group, significant correlations were observed for both central zones between corneal backscatter and age (3 mm: r=0.604, p=0.025; 5 mm: r=0.614, p=0.022 and central corneal thickness (3 mm: r=0.641, p=0.017; 5 mm: r=0.671, p=0.012; this was not found in the IDDM group (p>0.05. The presence of diabetes showed a significant effect on central corneal backscatter (Kruskal-Wallis test, p<0.001. Conclusions: Diabetic patients showed higher values of corneal light backscatter than healthy subjects. Corneal optical density analysis may be a useful tool for monitoring and assessing the ocular changes caused by diabetes.

  13. Age-dependent mixing of deep-sea sediments

    International Nuclear Information System (INIS)

    Smith, C.R.; Maggaard, L.; Pope, R.H.; DeMaster, D.J.

    1993-01-01

    Rates of bioturbation measured in deep-sea sediments commonly are tracer dependent; in particular, shorter lived radiotracers (such as 234 Th) often yield markedly higher diffusive mixing coefficients than their longer-lived counterparts (e.g., 210 Pb). At a single station in the 1,240-m deep Santa Catalina Basin, the authors document a strong negative correlation between bioturbation rate and tracer half-life. Sediment profiles of 234 Th (half-life = 24 days) yield an average mixing coefficient (60 cm 2 y -1 ) two orders of magnitude greater than that for 210 Pb (half-life = 22 y, mean mixing coefficient = 0.4 cm 2 y -1 ). A similar negative relationship between mixing rate and tracer time scale is observed at thirteen other deep-sea sites in which multiple radiotracers have been used to assess diffusive mixing rates. This relationship holds across a variety of radiotracer types and time scales. The authors hypothesize that this negative relationship results from age-dependent mixing, a process in which recently sedimented, food-rich particles are ingested and mixed at higher rates by deposit feeders than are older, food-poor particles. Results from an age-dependent mixing model demonstrate that this process indeed can yield the bioturbation-rate vs. tracer-time-scale correlations observed in deep-sea sediments. Field data on mixing rates of recently sedimented particles, as well as the radiotracer activity of deep-sea deposit feeders, provide strong support for the age-dependent mixing model. The presence of age-dependent mixing in deep-sea sediments may have major implications for diagenetic modeling, requiring a match between the characteristic time scales of mixing tracers and modeled reactants. 102 refs., 6 figs., 5 tabs

  14. Demoralization in Opioid Dependent Patients: A Comparative Study with Cancer Patients and Community Subjects

    NARCIS (Netherlands)

    Jong, C.A.J. de; Kissane, D.W.; Geessink, R.J.; Velden, D. van der

    2008-01-01

    Aim: To study existential distress or demoralization expressed as meaninglessness and helplessness in opioid dependent patients. xxx Method: Comparison of existential distress between opioid dependent patients (n=131), patients with advanced cancer (n=100) and a community based sample without severe

  15. Change in Care Dependency of Stroke Patients: A Longitudinal and Multicenter Study

    Directory of Open Access Journals (Sweden)

    Nursiswati Nursiswati, MN

    2017-06-01

    Conclusions: Based on the findings of this study, we recommend that hospital-based and community-based services should include continual care dependence monitoring using this comprehensive instrument. Care dependency is subject to change over time, therefore nurses have to plan and tailor adequate nursing care measures to patient needs in the different stages, especially with respect to the aspect of mobility.

  16. Correlates of benzodiazepine dependence in the Netherlands Study of Depression and Anxiety

    NARCIS (Netherlands)

    Manthey, L.; Lohbeck, M.; Giltay, E.J.; van Veena, T.; Zitman, F.G.; Penninx, B.W.J.H.

    2012-01-01

    Aims: Benzodiazepines (BZDs) are effective in the short term against anxiety and insomnia. However, some BZD users develop BZD dependence after a relatively short period of time. Therefore, we aimed to identify the risk factors of BZD dependence. Design: An observational cohort study. Setting: The

  17. The use of radiotracer techniques to study lubrication and wear in large diesel engines; Emploi des indicateurs radioactifs pour l'etude de la lubrification et de l'usure dans les moteurs diesel de grande puissance; Ispol'zovanie metodov radioaktivnykh indikatorov dlya izucheniya smazki i iznosa bol'shikh dizel'nykh motorov; Aplicacion de los indicadores radiactivos al estudio de la lubricacion y desgaste de los motores diesel de gran potencia

    Energy Technology Data Exchange (ETDEWEB)

    Howes, Jr, J E; Braun, W J; Sunderman, D N [Battelle Memorial Institute, Columbus, OH (United States)

    1962-01-15

    Radiotracer techniques have been applied to the study of lubrication and wear in large diesel engines on a scale not before considered practical, with perfect safety and with unique technological results. Both lubricating-oil consumption and cylinderliner wear have been evaluated as a function of operating conditions on diesel engines in the 1000 HP range. Techniques were developed for tapping 200 gal (US) of lubricating oil with 60 mc of zinc-65 and determining oil consumption by sampling exhaust gas during operation under a variety of conditions. Measurement of the rate of lubeoil consumption could be made in 10 min rather than the 24 to 48 h previously required. Irradiation techniques were developed for neutron activation of the lower cylinder portion of a 48-in long, 8-in diam. cylinder liner. Suitable thermal-neutron shielding allowed production of 300-d manganese-54 which resulted in extending the useful life of the liner for wear studies by a factor of six to eight over that of a comparable liner thermally activated to produce iron-59. The fact that studies with such large quantities of radioactive material can be carried out in standard research facilities in the diesel engine field opens an entirely new area to tracer applications. Selective activation and judicious use of thermalneutron shielding increases the versatility of the tracer technique in localizing measurement to areas of interest, reducing the total quantity of radioactive material required in wear studies of large parts, and facilitating simultaneous wear-measurement on engine parts of identical chemical composition. (author) [French] On s'est servi d'indicateurs radioactifs pour l'etude de la lubrification et de l'usure des moteurs diesel de grande puissance, et cela a une echelle qui jusqu'a present n'etait pas consideree comme pratiquement realisable, avec m e securite parfaite et des resultats technologiques sans precedent. La consommation de l'huile de graissage et l'usure des chemises

  18. Vascular risk factor burden, atherosclerosis, and functional dependence in old age: a population-based study.

    Science.gov (United States)

    Welmer, Anna-Karin; Liang, Yajun; Angleman, Sara; Santoni, Giola; Yan, Zhongrui; Cai, Chuanzhu; Qiu, Chengxuan

    2014-08-01

    Vascular risk factors such as hypertension and obesity have been associated with physical limitations among older adults. The purpose of this study is to examine whether individual and aggregated vascular risk factors (VRFs) are associated with functional dependence and to what extent carotid atherosclerosis (CAS) or peripheral artery disease (PAD) may mediate the possible associations of aggregated VRFs with functional dependence. This cross-sectional study included 1,451 community-living participants aged ≥60 years in the Confucius Hometown Aging Project of China. Data on demographic features, hypertension, high total cholesterol, obesity, smoking, physical inactivity, diabetes, CAS, PAD, and cardiovascular diseases (CVDs) were collected through an interview, a clinical examination, and laboratory tests. Functional dependence was defined as being dependent in at least one activity in the personal or instrumental activities of daily living. Data were analyzed using multiple logistic models controlling for potential confounders. We used the mediation model to explore the potential mediating effect of CAS and PAD on the associations of aggregated VRFs with functional dependence. Of the 1,451 participants, 222 (15.3%) had functional dependence. The likelihood of functional dependence increased linearly with increasing number of VRFs (hypertension, high total cholesterol, abdominal obesity, and physical inactivity) (p for trend dependence with clustering VRFs was mediated by CAS and PAD. Aggregation of multiple VRFs is associated with an increased likelihood of functional dependence among Chinese older adults; the association is partially mediated by carotid and peripheral artery atherosclerosis independently of CVDs.

  19. A cross-sectional study on tobacco use and dependence among women: Does menthol matter?

    Science.gov (United States)

    Rosenbloom, Judith; Rees, Vaughan W; Reid, Kathleen; Wong, Jeannie; Kinnunen, Taru

    2012-11-27

    The question of whether mentholation of cigarettes enhances tobacco dependence has generated conflicting findings. Potential mediating factors in a putative relationship between menthol use and tobacco dependence may include race and gender. While an association between menthol use and dependence is mixed, research on the role of race solely among women smokers is scarce. This study examined whether women menthol smokers have higher tobacco use and dependence than non-menthol smokers. Further, the study investigated differences between White and African American smokers. A cross-sectional study was conducted among 928 women seeking tobacco dependence treatment in Boston, Massachusetts. Measures obtained included preferred brand and menthol content, dependence markers (cigarettes per day (CPD); time to first cigarette in the morning; number of and longest previous quit attempts) and smoking history (age of initiation; years smoking; menthol or non-menthol cigarette preference). Analysis of variance (ANOVA) was used to detect interactions between menthol preference by race for continuous variables, and Pearson's chi-squared test was used for analyses with dichotomous variables. A greater proportion of menthol smokers smoked their first cigarette within five minutes of waking (p preferences. However, African American smokers smoked fewer CPD (pbrand for longer (p= .04). Women menthol smokers showed signs of greater tobacco dependence than non-menthol smokers. African Americans smoked fewer CPD but nevertheless had evidence of greater dependence.

  20. [{sup 11}C]d-threo-Methylphenidate, a new radiotracer for the dopamine transporter. Characterization in baboon and human brain

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y.S.; Volkow, N.D.; Fowler, J.S. [Brookhaven National Laboratory, Upton, NY (United States)] [and others

    1995-05-01

    dl-threo Methylphenidate (MP, Ritalin) is a psychostimulant drug which binds to the dopamine transporter (DAT). We evaluated [{sup 11}C]d-threo-methylphenidate ([{sup 11}C]d-MP), the more active enantiomer, as a radiotracer for the DAT in baboons and human brain. Stereoselectivity, saturability and pharmacological specificity and reproducibility were examined. Stereoselectivity was examined in baboons by comparing [{sup 11C}]d-MP,[{sup 11}C]l-MP and [{sup 11}C]dl-MP. Unlabeled MP was used to assess the reversibility and saturability of the binding. GBR 12909,{beta}-(4-iodophenyl)tropane-2-carboxylic acid methyl ester ({beta}-CIT), tomoxetine and citalopram were used to assess the specificity of the binding. The ratios between the radioactivity in the striatum to that in cerebellum (ST/CB) were 3.3,2.2 and 1.1 for [{sup 11}C]d-MP,[{sup 11}C]dl-MP and [{sup 11}C]l-MP respectively. Most of the striatal binding of [{sup 11}C]d-threo-MP was displaced by injection of nonradioactive MP demonstrating reversibility. Pretreatment with MP (0.5 mg/kg), GBR12909 (1.5 mg/kg) or {beta}-CIT (0.3 mg/kg) reduced ST/CB by about 60% and the ratios of distribution volumes at the steady-state for the triatum to cerebellum (DV{sub st/}DV{sub cb}) by about 50%. Pretreatment with tomoxetine (3.0 mg/kg) or citalopram (2.0 mg/kg), inhibitors of the norepinephrine and serotonin transporter, had no effect. Studies of [{sup 11}C]d-MP in the human brain showed highest uptake in basal ganglia with a half clearance time of about 60 minutes. Repeated studies in 6 normal human subjects showed differences in DV{sub st/}DV{sub cb} between -7% and 8%. MP pretreatment decreased BG but no cortical or cerebellar binding and reduced Bmax/Kd by 91%.

  1. What about getting physiological information into dynamic gamma camera studies

    International Nuclear Information System (INIS)

    Kiuru, A.; Nickles, R. J.; Holden, J. E.; Polcyn, R. E.

    1976-01-01

    A general technique has been developed for the multiplexing of time dependent analog signals into the individual frames of a gamma camera dynamic function study. A pulse train, frequency-modulated by the physiological signal, is capacitively coupled to the preamplifier servicing anyone of the outer phototubes of the camera head. These negative tail pulses imitate photoevents occuring at a point outside of the camera field of view, chosen to occupy a data cell in an unused corner of the computer-stored square image. By defining a region of interest around this cell, the resulting time-activity curve displays the physiological variable in temporal synchrony with the radiotracer distribution. (author)

  2. Age at onset typology in opioid dependent men: an exploratory study.

    Science.gov (United States)

    De, Biswajit; Mattoo, Surendra K; Basu, Debasish

    2002-04-01

    This study attempted to apply age at onset typology in ICD-10 diagnosed opioid dependence. The sample comprised 80 men seeking treatment at an addiction clinic. The measures included socio-demographic and clinical profile, Severity of Opioid Dependence Questionnaire, Modified Sensation Seeking Scale, Multiphasic Personality Questionnaire (MPQ) and Family History Assessment Module. A cut-off age of 20/21 years for an early-onset late-onset typology of opioid dependence was obtained using two methods - the modal age at onset method and one-third sample by age at onset method. The early onset group showed significant differences in terms of it being more often younger, urban, unmarried, wage earning or students, using oral opioids (not heroin or injectables), showing higher lifetime use and dependence of sedatives, earlier onset of use and dependence of sedatives and tobacco, and higher global psychopathology in terms of MPQ. The early onset group also showed statistically insignificant trends for lesser use and dependence of alcohol, higher severity of opioid dependence, more legal and less social complications, higher sensation seeking (except boredom susceptibility), and more frequent substance dependence in first degree relatives. The age at onset typology in opioid dependence appears to be feasible and having some similarities to similar typology in alcoholism.

  3. Application of tritium-labeled complex technical mixture of PCB congeners as radiotracer in ecological investigations

    International Nuclear Information System (INIS)

    Kim, A.A.

    2005-01-01

    The quantitative analysis of PCBs (polychlorinated biphenyls) is enough difficult analytical task. According to IUPAC nomenclature it is described more than 200 possible PCB congeners from which about 150 congeners are present at an environment. At the same time in environment PCBs are present as complex technical mixes of congeners (trade names include Apirolio, Aroclor, Clophen, Fenchlor, Kanechlor, Phenoclor, Pyralene, Pyranol, Pyroclor, Santotherm FR, and Sovol). In routine practice of gas chromatography analysis the quantitative measurement of PCB marker congeners is applied. In the most samples containing PCBs, there are often several dozens of different congeners. For practical reasons, all of them are not always measured, but the most important congeners are used as indicators. In Belgian chicken incident, only seven abundant congeners were usually measured: congeners with IUPAC numbers 28, 52, 101, 118, 138, 153, and 180 (2,4,4 '-TriCB, 2,2 ', 5,5 '-TCB, 2,2 ', 4,5,5 '-PeCB, 2,3 ', 4,4 ', 5-PeCB, 2,2 ', 3,4,4 ', 5 '-HxCB, 2,2 ', 4,4 ', 5,5 '-HxCB, 2,2 ', 3,4,4 ', 5,5 '-HpCB, respectively). The seven congeners are estimated to constitute about one third of all PCBs in the contaminated feed. Such measurement can give the big error in a quantitative estimation of PCBs contents in a sample. As alternative method of quantitative measurement PCBs the radiochemical method with use radioactive labeled PCBs as radiotracer can be used. We had been developed a method of synthesis of labeled by thermally activated tritium a complex technical mixture of PCBs congeners - Sovol. We had been showed a basic opportunity of receiving of uniformly tritium labeled mixture of PCBs congeners without structural failure of mixture. The tritium labeled preparation of complex technical mixture of PCBs congeners (Sovol) has been received. On the basis of received tritium labeled preparation of PCBs (Sovol) we had been developed the following quantitative and qualitative radiochemical

  4. Synthesis and radiolabelling of AG957 a potential tyrphostin PET radiotracer

    International Nuclear Information System (INIS)

    Ackermann, U.; Tochon-Danguy, H.J.; Sachinidis, J.; Burgess, A.W.; Scott, A.M.

    2000-01-01

    Full text: Signalling of tyrosine kinases is a critical component of intracellular regulation of growth and function. AG957 is an inhibitor of the c-ABL tyrosine kinase found in chronic myeloid leukemia, and the labelling of AG957 with a PET radiotracer would allow for the in vivo mapping of this receptor-kinase. Synthesis of the normethyl precursor of the tyrosine kinase inhibitor AG957 has been achieved by condensation of p-amino benzoic acid with 2,6 dihydroxy benzaldehyde and subsequent reduction of the imino function with sodium cyanoborohydride. The radiolabeling of this precursor using 11 C-methyliodide in basic conditions gave unsatisfactory yields because of decomposition of the starting material. We have therefore investigated the formation of 11 C-methyl esters using 11 Cmethanol and free carboxylic acids in the presence of either trimethylsilylchloride or boron trifluoride etherate as catalyst. P-amino benzoic acid, benzoic acid and salicylic acid were used as model compounds. Boron trifluoride etherate proved to be superior to trimethylsilylchloride giving good yields of the esters of the respective carboxylic acids when reacted with 11 C-methanol at 150 deg C. However, when this method was applied to desmethyl AG957, none of the desired product was obtained due to decomposition of the precursor at high temperatures. In light of these results we are planning to investigate the irreversible transesterification of enol esters with 11 C-methanol in the presence of a tin catalyst. This reaction is known to proceed smoothly at lower temperatures and should enable us to radiolabel the tyrosine kinase inhibitor 11 C-AG957. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. Change in Care Dependency of Stroke Patients: A Longitudinal and Multicenter Study.

    Science.gov (United States)

    Nursiswati, Nursiswati; Halfens, Ruud J G; Lohrmann, Christa

    2017-06-01

    The study was conducted to investigate the change of care dependency in stroke patients from inpatient wards and outpatient units in Indonesia. This study is longitudinal and multicentered. One hundred and nine patients were included from four hospitals on the island of Java. Care dependency was assessed using the Indonesian version of the 15-item Care Dependency Scale (CDS) at five points in time: at inpatient wards for admission and discharge and at outpatient units after discharge in the 1st week, the 5th week, and the 13th week. Most of the patients were male (65.1%), and diagnosed with ischemic stroke (71.5%). The results showed that care dependency in stroke patients decreased significantly from admission to discharge, as well as from the 5th to the 13th week as measured by the CDS. At admission, 23.0% of the patients were completely dependent on care, and at the 13th week about 1.0% were. Patients' care dependency decreased significantly in all care dependency items of the CDS in the inpatient ward, but five care dependency items of the CDS did not significantly decrease in the outpatient unit. Based on the findings of this study, we recommend that hospital-based and community-based services should include continual care dependence monitoring using this comprehensive instrument. Care dependency is subject to change over time, therefore nurses have to plan and tailor adequate nursing care measures to patient needs in the different stages, especially with respect to the aspect of mobility. Copyright © 2017. Published by Elsevier B.V.

  6. Studies of frequency dependent C-V characteristics of neutron irradiated p+-n silicon detectors

    International Nuclear Information System (INIS)

    Li, Zheng; Kraner, H.W.

    1990-10-01

    Frequency-dependent capacitance-voltage fluence (C-V) characteristics of neutron irradiated high resistivity silicon p + -n detectors have been observed up to a fluence of 8.0 x 10 12 n/cm 2 . It has been found that frequency dependence of the deviation of the C-V characteristic (from its normal V -1/2 dependence), is strongly dependent on the ratio of the defect density and the effective doping density N t /N' d . As the defect density approaches the effective dopant density, or N t /N' d → 1, the junction capacitance eventually assumes the value of the detector geometry capacitance at high frequencies (f ≤ 10 5 Hz), independent of voltage. A two-trap-level model using the concept of quasi-fermi levels has been developed, which predicts both the effects of C-V frequency dependence and dopant compensation observed in this study

  7. Women, drug dependency and consequences: a study from a developing country.

    Science.gov (United States)

    Khajedaluee, Mohammad; Dadgarmoghaddam, Maliheh; Erfanian, Majidreza; Alipourtabrizi, Arash; Khadem-Rezaiyan, Majid

    2015-01-01

    Introduction. Addiction in women can expose them to malnutrition, high blood pressure, cancer, and some other dangerous diseases like hepatitis, AIDS, or other sexual transmitted diseases. The aim of this study was to assess illegal sexual relations in three groups of women. Methods. This is a cross-sectional study that was done on 236 girls and young women aged 16-25 years in 2012 in three groups: vulnerable women who have substance dependency (crimes that had made women incarcerated were considered as vulnerability in this study), invulnerable women who have substance dependency (substance dependent women without a history of incarceration), and a control group (women with no history of substance dependency or being in prison). Results. 43.8% of vulnerable women who have substance dependency had extramarital sexual relations; this percentage was 55.8% in invulnerable women who have substance dependency and 1.4% in the control group. Crystal and methamphetamine abuse was higher in addicts who had extramarital sexual relations and alcohol abuse was correlated with unsafe sexual intercourse (r = 0.36, P = 0.001). There was a statistically significant difference in extramarital sexual relation based on marital status (P Poverty, drug dependency, divorce, and alcohol consumption make women prone to other high risk behaviors that need more attention.

  8. Women, Drug Dependency and Consequences: A Study from a Developing Country

    Directory of Open Access Journals (Sweden)

    Mohammad Khajedaluee

    2015-01-01

    Full Text Available Introduction. Addiction in women can expose them to malnutrition, high blood pressure, cancer, and some other dangerous diseases like hepatitis, AIDS, or other sexual transmitted diseases. The aim of this study was to assess illegal sexual relations in three groups of women. Methods. This is a cross-sectional study that was done on 236 girls and young women aged 16–25 years in 2012 in three groups: vulnerable women who have substance dependency (crimes that had made women incarcerated were considered as vulnerability in this study, invulnerable women who have substance dependency (substance dependent women without a history of incarceration, and a control group (women with no history of substance dependency or being in prison. Results. 43.8% of vulnerable women who have substance dependency had extramarital sexual relations; this percentage was 55.8% in invulnerable women who have substance dependency and 1.4% in the control group. Crystal and methamphetamine abuse was higher in addicts who had extramarital sexual relations and alcohol abuse was correlated with unsafe sexual intercourse (r=;0.36, P=0.001. There was a statistically significant difference in extramarital sexual relation based on marital status (P<0.001. Conclusions. Poverty, drug dependency, divorce, and alcohol consumption make women prone to other high risk behaviors that need more attention.

  9. Cigarette smoking, nicotine dependence and anxiety disorders: a systematic review of population-based, epidemiological studies

    Directory of Open Access Journals (Sweden)

    Moylan Steven

    2012-10-01

    Full Text Available Abstract Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective, the population assessed (random sample versus clinical population and diagnostic instrument utilized. Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM or International Classification of Diseases (ICD for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders. Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder, although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified. Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as

  10. Estimative of dilution factor for radioactive liquid effluents employing the H-3 and Cs-137 radiotracers present as pollutant; Estimativa do fator de diluicao para efluentes radioativos liquidos empregando os radiotracadores H-3 e Cs-137 presentes como poluentes

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo Bessa; Santos, Adir Janete Godoy dos, E-mail: mbnisti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    It was estimated the dilution factor for liquid effluents at the discharge points of the IPEN, Sao Paulo, Brazil, employing as radiotracers the radioisotope routinely liberated for the sewage of 'Cidade Universitaria Armando de Salles Oliveira' - CUASO {sup 3}H and {sup 137}Cs, not generating either monetary or environmental cost associated to the estimation. The {sup 137}Cs was determined by gamma spectrometry and the {sup 3}H was determined liquid phase scintillation. The results showed that the dilution factor varied according to the employed radiotracer in a crescent order of {sup 3}H and {sup 137}Cs according to the characteristics of each element. The average of dilution factors obtained at the first and second liberation day were 4.3 and 7.4 respectively for the {sup 3}H and 6.2 and 13.9 for the {sup 137}Cs. The ratio of dilution factors of calculated {sup 3}H and {sup 137}Cs were coherent with the ratio verified at the twelve hydrometers distributed by the IPEN campus. The dilution factors were estimated in operational and laboratory study, in a single controlled discharge of the TR1 tank

  11. Preliminary investigations to assess the usefulness of Be-7 as a radiotracer in soil covered by vegetation [Activities of the Soil and Water Management and Crop Nutrition Laboratory, Seibersdorf

    International Nuclear Information System (INIS)

    Iurian, Andra-Rada; Dercon, Gerd; Adu-Gyamfi, Joseph; Mabit, Lionel; Kis-Benedek, Gyula; Ceccatelli, Alessia; Tarjan, Sandor; Blake, William

    2014-01-01

    Different factors may affect the extent of radionuclides’ interception by plants and therewith their inventories in soil covered areas. In particular, there is interest in assessing the impact of the vegetation factor for different soil coverage conditions, when using 7 Be as radiotracer of soil redistribution in cropped farmland. Our results suggest that 7 Be foliar interception of bean plants is likely to affect the radionuclide inventories and their spatial uniformity in covered soil. Reliable results on short-term erosion using 7 Be can be obtained in cropped farmland with limited cover, but only when taking into account the interception factor. The impact of the interception factor is highly dependent on rainfall intensity and duration, crop species and the growing stage of the plants. Further investigations into these variables are required

  12. Preliminary investigations to assess the usefulness of Be-7 as a radiotracer in soil covered by vegetation [Activities of the Soil and Water Management and Crop Nutrition Laboratory, Seibersdorf

    Energy Technology Data Exchange (ETDEWEB)

    Iurian, Andra-Rada [Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca (Romania); Dercon, Gerd; Adu-Gyamfi, Joseph; Mabit, Lionel [Soil and Water Management and Crop Nutrition Laboratory, Joint FAO/IAEA Division for Nuclear Techniques in Food and Agriculture, Seibersdorf (Austria); Kis-Benedek, Gyula; Ceccatelli, Alessia; Tarjan, Sandor [3Terrestrial Environment Laboratory, IAEA Environment Laboratories, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Seibersdorf (Austria); Blake, William [School of Geography, University of Plymouth, Plymouth (United Kingdom); others, and

    2014-07-15

    Different factors may affect the extent of radionuclides’ interception by plants and therewith their inventories in soil covered areas. In particular, there is interest in assessing the impact of the vegetation factor for different soil coverage conditions, when using {sup 7}Be as radiotracer of soil redistribution in cropped farmland. Our results suggest that {sup 7}Be foliar interception of bean plants is likely to affect the radionuclide inventories and their spatial uniformity in covered soil. Reliable results on short-term erosion using {sup 7}Be can be obtained in cropped farmland with limited cover, but only when taking into account the interception factor. The impact of the interception factor is highly dependent on rainfall intensity and duration, crop species and the growing stage of the plants. Further investigations into these variables are required.

  13. Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies.

    Science.gov (United States)

    Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W; Tremlett, Helen

    2018-06-01

    In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

  14. Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Shenoy, K.T.; Sreenivas, T.

    2015-01-01

    An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40–60 MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. - Highlights: • Radiotracer technique was applied for evaluation of design of a pilot-scale continuous leaching reactor. • Mean residence time and dead volume were estimated. Dead volume was found to be ranging from 4% to 15% at different operating conditions. • Tank-in-series model was used to simulate the measured RTD data and was found suitable to describe the flow in the reactor. • No flow abnormality was found and the reactor behaved as a well-mixed system. The design of the reactor was validated

  15. Assessment of abstract reasoning abilities in alcohol-dependent subjects: an fMRI study

    International Nuclear Information System (INIS)

    Bagga, Deepika; Singh, Namita; Singh, Sadhana; Modi, Shilpi; Kumar, Pawan; Bhattacharya, D.; Garg, Mohan L.; Khushu, Subash

    2014-01-01

    Chronic alcohol abuse has been traditionally associated with impaired cognitive abilities. The deficits are most evident in higher order cognitive functions, such as abstract reasoning, problem solving and visuospatial processing. The present study sought to increase current understanding of the neuropsychological basis of poor abstract reasoning abilities in alcohol-dependent subjects using functional magnetic resonance imaging (fMRI). An abstract reasoning task-based fMRI study was carried out on alcohol-dependent subjects (n = 18) and healthy controls (n = 18) to examine neural activation pattern. The study was carried out using a 3-T whole-body magnetic resonance scanner. Preprocessing and post processing was performed using SPM 8 software. Behavioral data indicated that alcohol-dependent subjects took more time than controls for performing the task but there was no significant difference in their response accuracy. Analysis of the fMRI data indicated that for solving abstract reasoning-based problems, alcohol-dependent subjects showed enhanced right frontoparietal neural activation involving inferior frontal gyrus, post central gyrus, superior parietal lobule, and occipito-temporal gyrus. The extensive activation observed in alcohol dependents as compared to controls suggests that alcohol dependents recruit additional brain areas to meet the behavioral demands for equivalent task performance. The results are consistent with previous fMRI studies suggesting decreased neural efficiency of relevant brain networks or compensatory mechanisms for the execution of task for showing an equivalent performance. (orig.)

  16. Assessment of abstract reasoning abilities in alcohol-dependent subjects: an fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Bagga, Deepika; Singh, Namita; Singh, Sadhana; Modi, Shilpi; Kumar, Pawan [Institute of Nuclear Medicine and Allied Sciences (INMAS), NMR Research Centre, Delhi (India); Bhattacharya, D. [Base Hospital, Department of Psychiatry, Delhi Cantt (India); Garg, Mohan L. [Panjab University, Department of Biophysics, Chandigarh (India); Khushu, Subash [Institute of Nuclear Medicine and Allied Sciences (INMAS), NMR Research Centre, Delhi (India); INMAS, DRDO, NMR Research Centre, Delhi (India)

    2014-01-15

    Chronic alcohol abuse has been traditionally associated with impaired cognitive abilities. The deficits are most evident in higher order cognitive functions, such as abstract reasoning, problem solving and visuospatial processing. The present study sought to increase current understanding of the neuropsychological basis of poor abstract reasoning abilities in alcohol-dependent subjects using functional magnetic resonance imaging (fMRI). An abstract reasoning task-based fMRI study was carried out on alcohol-dependent subjects (n = 18) and healthy controls (n = 18) to examine neural activation pattern. The study was carried out using a 3-T whole-body magnetic resonance scanner. Preprocessing and post processing was performed using SPM 8 software. Behavioral data indicated that alcohol-dependent subjects took more time than controls for performing the task but there was no significant difference in their response accuracy. Analysis of the fMRI data indicated that for solving abstract reasoning-based problems, alcohol-dependent subjects showed enhanced right frontoparietal neural activation involving inferior frontal gyrus, post central gyrus, superior parietal lobule, and occipito-temporal gyrus. The extensive activation observed in alcohol dependents as compared to controls suggests that alcohol dependents recruit additional brain areas to meet the behavioral demands for equivalent task performance. The results are consistent with previous fMRI studies suggesting decreased neural efficiency of relevant brain networks or compensatory mechanisms for the execution of task for showing an equivalent performance. (orig.)

  17. Study of energetic dependence of LiF TLDs for photons

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, Tassio A.; Antunes, Paula C.G.; Paiva, Fabio; Branco, Isabela S.; Sena, Michelle K.S.; Siqueira, Paulo T.D.; Yoriyaz, Helio, E-mail: tcavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The LiF TLDs are widely used for photon dosimetry. However, in the most case the energetic dependence of these TLDs are not taken into account. This work is a preliminary study of energetic photon dependence in LiF TLD (TLD 700, enriched with {sup 7}Li). For this study it was utilized a methodology already used in others works that seek understand the dependence energetic of TLD. It was utilized three different X-ray spectrum and a {sup 137}Cs source; Beyond the calculus utilized in previous works, it was built the calibration curve for each spectrum to see the difference in dosimetry that the energetic dependence could cause. (author)

  18. Motivation and exercise dependence: a study based on self-determination theory.

    Science.gov (United States)

    González-Cutre, David; Sicilia, Alvaro

    2012-06-01

    The objective of this study was to use self-determination theory to analyze the relationships of several motivational variables with exercise dependence. The study involved 531 exercisers, ranging in age from 16 to 60 years old, who responded to differentquestionnaires assessing perception of motivational climate, satisfaction of basic psychological needs, motivation types, and exercise dependence. The results of multiple mediation analysis revealed that ego-involving climate and perceived competence positively predicted exercise dependence in a directed and mediated manner through introjected and external regulation. Gender and age did not moderate the analyzed relationships. These results allow us to better understand the motivational process explaining exercise dependence, demonstrating the negative influence of the ego-involving climate in the context of exercise.

  19. Diffuse pulmonary uptake of bone-seeking radiotracer in bone scintigraphy of a rare case of pulmonary alveolar microlithiasis

    International Nuclear Information System (INIS)

    Fallahi, Babak; Ghafary, Bahar Moasses; Fard-Esfahani, Armaghan; Eftekhari, Mohammad

    2005-01-01

    Pulmonary alveolar microlithiasis (PAM) is a rare diffuse pulmonary disease representing microliths formed by deposition of calcium phosphonate in the alveolar airspaces. PAM is often diagnosed incidentally during chest X-ray imaging. Most of them are asymptomatic. We present a 39-year-old man referring for a bone scan due to a complaint of right leg pain. Bone scan showed diffuse uptake of bone-seeking radiotracer on both lung fields predominantly in basal regions. The bronchoalveolar lavage test confirmed the diagnosis of PAM

  20. The Dutch Cannabis Dependence (CanDep) study on the course of frequent cannabis use and dependence: objectives, methods and sample characteristics

    NARCIS (Netherlands)

    van der Pol, P.; Liebregts, N.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.

    2011-01-01

    This paper presents an overview of the prospective cohort design of the Dutch Cannabis Dependence (CanDep) study, which investigates (i) the three-year natural course of frequent cannabis use (≥ three days per week in the past 12 months) and cannabis dependence; and (ii) the factors involved in the

  1. Oppositional defiant disorder (ODD), the forerunner of alcohol dependence: a controlled study.

    Science.gov (United States)

    Ghosh, Abhishek; Malhotra, Savita; Basu, Debasish

    2014-10-01

    There are common genetic, neurobiological and psycho-social substrates for oppositional defiant disorder (ODD) and substance dependence. ODD can be regarded as the mildest and earliest form of disruptive behavioral disorder and also represents the threshold of vulnerability for substance dependence. But it is a less researched area. The aim of this research was to study any possible association between childhood ODD and adult alcohol dependence. Data are presented from a non probability sample of 100 adult alcohol dependent subjects and equal number of biologically unrelated control subjects. Assessment was conducted by the instrument Semi-Structured Assessment for the Genetics of Alcoholism for both the assessment of ODD and alcohol dependence. The results of this study demonstrated significant association between childhood ODD and adult alcohol dependence. The association remained significant even after the exclusion of the possible confounding effects of the presence of conduct disorder and attention deficit hyperactivity disorder. Our study should encourage further research in this area and is expected to open up an opportunity for preventive research. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Nuclear matter studies with density-dependent meson-nucleon coupling constants

    International Nuclear Information System (INIS)

    Banerjee, M.K.; Tjon, J.A.; Banerjee, M.K.; Tjon, J.A.

    1997-01-01

    Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the g σNN , as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified σN coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for E/A and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered. copyright 1997 The American Physical Society

  3. A Study of Daily Living Dependency Status among Elderly in an Urban Slum area of Dehradun

    Directory of Open Access Journals (Sweden)

    Puneet Ohri

    2014-12-01

    Full Text Available Background: Population aging is observed world-wide. As per Census 2011, elderly constitutes 7.4% population of India. It is expected to increase to 20% in 2050. This segment of population faces multiple medical and psychological problems. To address and solve these problems great effort from the country and the community is required. Objective: To assess the daily living dependency status among elderly. Method:  A cross sectional study was conducted in Dehradun, among 215 elderly people, using a pre-structured questionnaire. Their activities of daily living (ADL and Instrumental activities of daily living (IADL were recorded by observation and interviewing them with their families. Results: Out of total, 93% individuals were independent in their ADLs, with more dependence in the very old elderly. Maximum inability was found in Bathing and dressing. 70.7% elderly were dependent on one or more IADLs, female elderly being more dependent than male (p<0.05. However there was no significant difference of dependence in the male and female elderly in performing ADLs. Education and socio-economic status had a positive effect on independence in IADLs. Among all IADLs male elderly showed a maximum dependency for cooking and laundry while females showed a greater dependency in using telephone, managing money and travelling.

  4. A Study of Daily Living Dependency Status among Elderly in an Urban Slum area of Dehradun

    Directory of Open Access Journals (Sweden)

    Puneet Ohri

    2014-12-01

    Full Text Available Background: Population aging is observed world-wide. As per Census 2011, elderly constitutes 7.4% population of India. It is expected to increase to 20% in 2050. This segment of population faces multiple medical and psychological problems. To address and solve these problems great effort from the country and the community is required. Objective: To assess the daily living dependency status among elderly. Method:  A cross sectional study was conducted in Dehradun, among 215 elderly people, using a pre-structured questionnaire. Their activities of daily living (ADL and Instrumental activities of daily living (IADL were recorded by observation and interviewing them with their families. Results: Out of total, 93% individuals were independent in their ADLs, with more dependence in the very old elderly. Maximum inability was found in Bathing and dressing. 70.7% elderly were dependent on one or more IADLs, female elderly being more dependent than male (p<0.05. However there was no significant difference of dependence in the male and female elderly in performing ADLs. Education and socio-economic status had a positive effect on independence in IADLs. Among all IADLs male elderly showed a maximum dependency for cooking and laundry while females showed a greater dependency in using telephone, managing money and travelling.

  5. Depression and care-dependency in Parkinson's disease: results from a nationwide study of 1449 outpatients.

    Science.gov (United States)

    Riedel, O; Dodel, R; Deuschl, G; Klotsche, J; Förstl, H; Heuser, I; Oertel, W; Reichmann, H; Riederer, P; Trenkwalder, C; Wittchen, H-U

    2012-06-01

    Parkinson's disease (PD) is frequently compounded by neuropsychiatric complications, increasing disability. The combined effect of motor and mental status on care-dependency in PD outpatients is not well characterized. We conducted a cross-sectional study of 1449 PD outpatients. The assessment comprised the Montgomery-Asberg Depression Rating Scale (MADRS) and the diagnostic criteria for dementia. PD severity and treatment complications were rated using Hoehn and Yahr staging and the Unified Parkinson's Disease Rating Scale (UPDRS) IV. The acknowledged level of care-dependency was documented. Care-dependency was present in 18.3% of all patients. A total of 13.9% had dementia, 18.8% had depression, and 14.3% had both. Regression analyses revealed increasing effects of age, PD duration, and PD severity on care-dependency in all three mental-disorder subgroups with the strongest effects in patients with depression only. Depressed patients with antidepressive treatment still had significantly higher PD severity, higher MADRS and UPDRS-IV scores but were not more likely to be care-dependent than non-depressed patients. Older age, longer duration and increased severity of PD contribute to care-dependency in patients with untreated depression. Treatment of depression is associated with lower rates of care-dependency. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. A Preliminary Study of Sexual Dysfunction in Male Opioid-Dependants under Methadone Maintenance Treatment

    Directory of Open Access Journals (Sweden)

    Masoudeh Babakhanian

    2011-08-01

    Full Text Available Introduction: Sexual dysfunction is one of the prevalent problems of opiate-dependent patients. The current preliminarily study examines sexual dysfunction in a group of opiate-dependent patients before and after 6 months of MMT. Methods: The current study is a cross-sectional study. The numbers of 30 opiate-dependent patients were selected of Cheraghiyan clinic in Damghan, Iran. Demographics questionnaire and the International Index of Erectile Function were administered before and after treatment. Results: Erectile function showed an increase and intercourse satisfactions completely improved. Sexual desire and overall satisfaction increased, showing slight improvement while orgasmic function increased showing no improvement. Discussion: The findings revealed the prevalence of sexual dysfunction and improvement of some component in patients after treatment. Future studies are needed to explore the roles of other factors.

  7. Radiotracer studies of pesticide residues in edible oil seeds and related products

    International Nuclear Information System (INIS)

    1979-01-01

    Ten papers were presented in which chemical pollution due to insecticides was examined in edible oil seeds and their products. They include hexachlorocyclohexane residues in groundnut; carbaryl in groundnut; maize and cotton seed products, and in lactating goats; propoxur in cocoa beans; and leptophos residues in cotton seed and its products and in lactating goats. Eight of these papers constitute separate INIS entries. Egypt, Ghana, India, Korea, Lebanon, Pakistan, the Philippines, Poland, and the Sudan participated under the coordinated research programme. The progress of the programme is reviewed, and problems and priorities for future development of the programme are identified. A number of recommendations are addressed to the Joint FAO/IAEA Secretariat

  8. Study of solutions flow in a pilot copper leaching pile, using tritium as radiotracer

    International Nuclear Information System (INIS)

    Diaz V, Francisco; Duran P, Oscar

    1997-01-01

    The general objective of this work is featuring the flow of a solution in a pilot cooper leaching pile. The irrigating solutions were labeled with Tritium in the form of tritiated water, and the solution flow path is determined in a duct which recover all the solution at the outlet of the pile. This work is an important tool for describing the pipe's hydrodynamic behavior.It also provide experimental semi-industrial data profitable for defining parameters for the calibration or validation of models. The pile has 3788 tons of mineral ore with a high of 6 meters and upper and l