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Sample records for metabolic tracer studies

  1. Skeletal scintigraphy and quantitative tracer studies in metabolic bone disease

    Science.gov (United States)

    Fogelman, Ignac

    Bone scan imaging with the current bone seeking radiopharmaceuticals, the technetium-99m labelled diphosphonates, has dramatically improved our ability to evaluate skeletal pathology. In this thesis, chapter 1 presents a review of the history of bone scanning, summarises present concepts as to the mechanism of uptake of bone seeking agents and briefly illustrates the role of bone scanning in clinical practice. In chapter 2 the applications of bone scan imaging and quantitative tracer techniques derived from the bone scan in the detection of metabolic bone disease are discussed. Since skeletal uptake of Tc-99m diphosphonate depends upon skeletal metabolism one might expect that the bone scan would be of considerable value in the assessment of metabolic bone disease. However in these disorders the whole skeleton is often diffusely involved by the metabolic process and simple visual inspection of the scan image may not reveal the uniformly increased uptake of tracer. Certain patterns of bone scan abnormality have, however, been reported in patients with primary hyperparathyroidism and renal osteo-dystrophy; the present studies extend these observations and introduce the concept of "metabolic features" which are often recognisable in conditions with generalised increased bone turnover. As an aid to systematic recognition of these features on a given bone scan image a semi-quantitative scoring system, the metabolic index, was introduced. The metabolic index allowed differentiation between various groups of patients with metabolic disorders and a control population. In addition, in a bone scan study of patients with acromegaly, it was found that the metabolic index correlated well with disease activity as measured by serum growth hormone levels. The metabolic index was, however, found to be a relatively insensitive means of identifying disease in individual patients. Patients with increased bone turnover will have an absolute increase in skeletal uptake of tracer. As a

  2. Aluminum metabolism studied by [sup 26]Al tracer using AMS technique

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Hotta, Masayoshi; Ohashi, Hideo

    1992-01-01

    By accelerator mass spectrometry (AMS), we studied aluminum metabolism using [sup 26]Al as a tracer. To investigate the role of aluminum toxicity in the etiology of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, aluminum incorporation into the rat cerebrum was studied. When healthy rats were injected intraperitoneally with [sup 26]Al, a considerable amount of the tracer was incorporated into the brain within only 5 days after the injection. This [sup 26]Al accumulation was apparently irreversible, since it persisted even after 75 days. (author).

  3. Choice of infusion-sampling mode for tracer studies of free fatty acid metabolism

    International Nuclear Information System (INIS)

    Jensen, M.D.; Rogers, P.J.; Ellman, M.G.; Miles, J.M.

    1988-01-01

    To determine the preferred infusion-sampling mode for isotopic studies of free fatty acid (FFA) metabolism, tracer [( 14 C]palmitate) was infused into the left ventricle of five anesthetized dogs, and tracee ([ 3 H]palmitate) was infused into three separate peripheral veins of each dog. The [ 14 C]palmitate specific activity (SA) was lower in mixed venous than arterial blood, and [ 3 H]palmitate SA was equal in both sites. The actual infusion rate of [ 3 H]palmitate [2.15 +/- 0.31 X 10(5) disintegrations/min (dpm).kg-1.min-1] could be accurately predicted (2.14 +/- 0.32 X 10(5) dpm.kg-1.min-1) using the known [ 14 C]palmitate infusion rate and the arterial plasma [ 14 C]-to-[ 3 H]palmitate ratio. In contrast, the mixed venous [ 14 C]-to-[ 3 H]palmitate ratio resulted in overestimates (P less than 0.05) of the actual [ 3 H]palmitate infusion rate. In summary, venous tracer infusion with arterial blood sampling for FFA tracer studies provides the most accurate estimates of tracee rate of appearance

  4. Multiple stable isotope tracer technique for studying the metabolic kinetics of amino acids in hepatic failure

    Energy Technology Data Exchange (ETDEWEB)

    Zongqin, Xia; Tengchang, Dai; Jianhua, Zhang; Yaer, Hu; Bingyao, Yu; Xingrong, Xu; Guanlu, Huang; Gengrong, Shen; Yaqiu, Zhou; Hong, Yu

    1987-08-01

    In order to study the mechanism of the imbalance of amino acid metabolism during hepatic failure, a stable isotope tracer method for observing simultaneously the metabolic kinetics of several amino acids has been established. /sup 15/N-L-Ala, (2,3-D/sub 3/)-Leu and (2,3-D/sub 3/)-Phe were chosen as nonessential, branched chain and aromatic amino acids. A single iv injection of 40 mg N-Ala, 20 mg deuterated Leu and 20 mg deuterated Phe was given to each human subject. Blood samples were taken just before and at different times (up to 60 min) after the injection. Total free amino acids were isolated from the plasma with a small dowex 50 x 8 column and converted to trifluoroacetyl derivatives. Their abundances were then analyzed with a GC-MS system and typical double exponential time course curves were found for all the three labelled amino acids. A two-pool model was designed and applied for compartmental analysis. Significant changes were found in the kinetic parameters of Phe and Leu in patients with fulminant hepatitis or heptic cirrhosis. The half-lives of both Phe pools were longer and the pool sizes were larger than normal subjects, while the half-lives and pool sizes of Leu changes in the opposite direction. No marked change was found in Ala. The significance of intracellular imbalance of Phe and Leu metabolism was discussed. It is evident that the combination of GCMS technique and multiple-tracers labelled with stable isotopes is of great potential for similar purposes.

  5. The use of tracer techniques in pesticide balance and metabolism studies

    International Nuclear Information System (INIS)

    Fuehr, F.

    1977-01-01

    The radioisotope tracing technique has been a useful tool in obtaining extensive information on the fate of pesticides in the soil-plant systems, including their uptake, transport and metabolism by plants; their photochemical, chemical and microbial degradation; their adsorption, desorption and translocation in soil; and their bioavailability to untreated crops. A pesticide balance study under practical field conditions using radio labelling can examine a number of factors affecting the fate of a compound at the same time and assess the magnitude of the major processes involved. On the basis of these results, more detailed studies are then formulated to be conducted under an exactly defined environment of a growth chamber or a laboratory. The use of tracer techniques in such studies is reported. (author)

  6. Clinical studies of bone metabolism using a simple model of calcium tracer kinetics

    International Nuclear Information System (INIS)

    Roncari, G.; Milan Univ., Varese

    1981-01-01

    Bone metabolism studies were performed in 44 subjects with and without bone disease using a calcium tracers kinetics model, the central feature of which is an expanding exchangeable calcium pool. In normal subjects the accretion rate and the exchangeable calcium pool ranged from 1.49 to 8.45 (mean 3.9 +- 2.05) mg.d -1 kg -1 and from 60 to 131 (mean 81.25 +- 18.11) mg.kg -1 , respectively. The patients with osteogenesis imperfecta, Pierre Marie's disease and one out of two cases of hypoparathyroidism had values which fell within the normal range. Both the accretion rate and the exchangeable calcium pool were significantly elevated in patients with Paget's disease and with hyperparathyroidism. Uremic patients with generalizated bone lesions had accretion rates or both parameters elevated. As far as patients with successful renal transplant are concerned, the results suggest that this method is a very poor means for detecting bone disorders with only focal lesions. In contrast, the method can be very useful when persistent renal osteodystrophy or secondary hyperparathyroidism are suspected. (orig.) [de

  7. Clinical studies of bone metabolism using a simple model of calcium tracer kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Roncari, G.

    1981-08-01

    Bone metabolism studies were performed in 44 subjects with and without bone disease using a calcium tracer kinetics model, the central feature of which is an expanding exchangeable calcium pool. In normal subjects the accretion rate and the exchangeable calcium pool ranged from 1.49 to 8.45 (mean 3.9 +- 2.05) mg.d/sup -1/kg/sup -1/ and from 60 to 131 (mean 81.25 +- 18.11) mg.kg/sup -1/, respectively. The patients with osteogenesis imperfecta, Pierre Marie's disease and one out of two cases of hypoparathyroidism had values which fell within the normal range. Both the accretion rate and the exchangeable calcium pool were significantly elevated in patients with Paget's disease and with hyperparathyroidism. Uremic patients with generalizated bone lesions had accretion rates or both parameters elevated. As far as patients with successful renal transplant are concerned, the results suggest that this method is a very poor means for detecting bone disorders with only focal lesions. In contrast, the method can be very useful when persistent renal osteodystrophy or secondary hyperparathyroidism are suspected.

  8. Historical and contemporary stable isotope tracer approaches to studying mammalian protein metabolism

    Science.gov (United States)

    2016-01-01

    Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward by the Nobel laureates JJ Thomson and FW Aston, enabling the accurate separation, identification, and quantification of the relative abundance of these isotopes. As a result, within a few years, the number of known isotopes both stable and radioactive had greatly increased and there are now over 300 stable or radioisotopes presently known. Unknown at the time, however, was the potential utility of these isotopes within biological disciplines, it was soon discovered that these stable isotopes, particularly those of carbon (13C), nitrogen (15N), oxygen (18O), and hydrogen (2H) could be chemically introduced into organic compounds, such as fatty acids, amino acids, and sugars, and used to “trace” the metabolic fate of these compounds within biological systems. From this important breakthrough, the age of the isotope tracer was born. Over the following 80 yrs, stable isotopes would become a vital tool in not only the biological sciences, but also areas as diverse as forensics, geology, and art. This progress has been almost exclusively driven through the development of new and innovative mass spectrometry equipment from IRMS to GC‐MS to LC‐MS, which has allowed for the accurate quantitation of isotopic abundance within samples of complex matrices. This historical review details the development of stable isotope tracers as metabolic tools, with particular reference to their use in monitoring protein metabolism, highlighting the unique array of tools that are now available for the investigation of protein metabolism in vivo at a whole body down to a single protein level

  9. Compartmental Modeling and Dosimetry of in Vivo Metabolic Studies of Leucine and Three Secretory Proteins in Humans Using Radioactive Tracers

    Science.gov (United States)

    Venkatakrishnan, Vaidehi

    1995-01-01

    Physical and mathematical models provide a systematic means of looking at biological systems. Radioactive tracer kinetic studies open a unique window to study complex tracee systems such as protein metabolism in humans. This research deals with compartmental modeling of tracer kinetic data on leucine and apolipoprotein metabolism obtained using an endogenous tritiated leucine tracer administered as a bolus, and application of compartmental modeling techniques for dosimetric evaluation of metabolic studies of radioiodinated apolipoproteins. Dr. Waldo R. Fisher, Department of Medicine, was the coordinating research supervisor and the work was carried out in his laboratory. A compartmental model for leucine kinetics in humans has been developed that emphasizes its recycling pathways which were examined over two weeks. This model builds on a previously published model of Cobelli et al, that analyzed leucine kinetic data up to only eight hours. The proposed model includes different routes for re-entry of leucine from protein breakdown into plasma accounting for proteins which turn over at different rates. This new model successfully incorporates published models of three secretory proteins: albumin, apoA-I, and VLDL apoB, in toto thus increasing its validity and utility. The published model of apoA-I, based on an exogenous radioiodinated tracer, was examined with data obtained using an endogenous leucine tracer using compartmental techniques. The analysis concludes that the major portion of apoA-I enters plasma by a fast pathway but the major fraction of apoA-I in plasma resides with a second slow pathway; further the study is suggestive of a precursor-product relationship between the two plasma apoA-I pools. The possible relevance of the latter suggestion to the aberrant kinetics of apoA-I in Tangier disease is discussed. The analysis of apoA-II data resulted in similar conclusions. A methodology for evaluating the dosimetry of radioiodinated apolipoproteins by

  10. 24-Hour protein, arginine and citrulline metabolism in fed critically ill children – a stable isotope tracer study

    Science.gov (United States)

    de Betue, Carlijn T.I.; Garcia Casal, Xiomara C.; van Waardenburg, Dick A.; Schexnayder, Stephen M.; Joosten, Koen F.M.; Deutz, Nicolaas E.P.; Engelen, Marielle P.K.J.

    2017-01-01

    Background & aims The reference method to study protein and arginine metabolism in critically ill children is measuring plasma amino acid appearances with stable isotopes during a short (4–8h) time period and extrapolate results to 24-hour. However, 24-hour measurements may be variable due to critical illness related factors and a circadian rhythm could be present. Since only short duration stable isotope studies in critically ill children have been conducted before, the aim of this study was to investigate 24-hour appearance of specific amino acids representing protein and arginine metabolism, with stable isotope techniques in continuously fed critically ill children. Methods In eight critically ill children, admitted to the pediatric (n=4) or cardiovascular (n=4) intensive care unit, aged 0–10 years, receiving continuous (par)enteral nutrition with protein intake 1.0–3.7 g/kg/day, a 24-hour stable isotope tracer protocol was carried out. L-[ring-2H5]-phenylalanine, L-[3,3-2H2]-tyrosine, L-[5,5,5-2H3]-leucine, L-[guanido-15N2]-arginine and L-[5-13C-3,3,4,4-2H4]-citrulline were infused intravenously and L-[15N]-phenylalanine and L-[1-13C]leucine enterally. Arterial blood was sampled every hour. Results Coefficients of variation, representing intra-individual variability, of the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline were high, on average 14–19% for intravenous tracers and 23–26% for enteral tracers. No evident circadian rhythm was present. The pattern and overall 24-hour level of whole body protein balance differed per individual. Conclusions In continuously fed stable critically ill children, the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline show high variability. This should be kept in mind when performing stable isotope studies in this population. There was no apparent circadian rhythm. PMID:28089618

  11. The choice of label and measurement technique in tracer studies of body protein metabolism in man

    International Nuclear Information System (INIS)

    James, W.P.T.; Sender, P.M.; Garlick, P.J.; Waterlow, J.C.

    1975-01-01

    The turnover of non-serum proteins in man has had limited study despite the physiological importance of maintaining the balance between synthesis and breakdown of body proteins. Body protein is usually considered as a single pool and breakdown rates are often measured by monitoring excreted label at intervals after pulse labelling with radioactive or 15 N amino acids. No label has yet been used for measuring tissue protein breakdown in man which is free from the major problem of label re-utilization. All measurements of breakdown rates, eg. with 75 Se-selenomethionine, 15 N- or 14 C-glycine, give rate constants which are too low. The heterogeneity of body proteins also means that an estimate of the weighted average breakdown rate can only be obtained after following the excretion of isotope for a long period, perhaps of the order of 3-4 half-lives which, for man, would be 100 days after labelling. We therefore use infusions with either 14 C- or 15 N-labelled amino acids to measure breakdown and synthesis rates: these values are less affected by problems of protein heterogeneity. Single injection techniques are subject to more error than constant infusions of label because of the difficulty of defining the precursor activity. 15 N labelling need not be confined to essential amino acids if total protein rather than amino acid turnover is studied: the latter involves measurements of the labelled amino acid itself which is difficult with 15 N because of the small amounts of free amino acid nitrogen available. Carbon labelling of non-essential amino acids is unsuitable for studies of protein turnover and the choice of the position of the label on the molecule is important when labelled essential amino acids are employed. Short-term changes in protein metabolism are evaluated better with amino acids with a small pool size; the equilibration time in the excretory bicarbonate pool is also shorter than in the urea pool so that 15 N is less useful than carbon labelling. We

  12. Carbon-14 tracer studies in the metabolism of isolated rat-liver parenchymal cells under conditions of gluconeogenesis from lactate and pyruvate

    International Nuclear Information System (INIS)

    Muellhofer, G.; Mueller, C.; Stetten, C. von; Gruber, E.

    1977-01-01

    In rat liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate, 14 C-labeling patterns of metabolites with (1- 14 C)-labeled and (2- 14 C)-labeled lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]octanoate as tracers have been obtained which do not agree with generally assumed reaction schemes. The experiments have been repeated with incubations of isolated rat-liver parenchymal cells. The results demonstrate that the discrepancies between expected and analysed 14 C-labeling patterns of metabolites were still existent. From this observation, it may be concluded that 14 C-labelling patterns of metabolites are indicative for the existence of still unknown metabolic relationships in liver parenchymal cells. Furthermore, the results of our experiments prove that conclusions based on the exclusive analysis of metabolite levels are of limited value for studying intracellular events, because of uncharacterized compartmentations, which become evident in 14 C-tracer studies. It cannot be answered by our studies whether the apparent existence of differently labelled species of citrate, oxoglutarate, or acetyl-CoA represent intracellular compartmentation, or whether it is the result of metabolic heterogeneity of liver parenchym cells. (orig.) [de

  13. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    International Nuclear Information System (INIS)

    Clerico, A.; Marastoni, M.; Del Chicca, M.G.; Giannessi, D.; Del Ry, S.; Andreassi, M.G.; Sabatino, L.; Iascone, M.R.; Biagini, A.; Donato, L.

    1995-01-01

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic α h 1-28 ANP and some hormone metabolites were iodinated with Na 125 I or Na 131 I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of 125 I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [ 125 I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs

  14. Evaluation of the protein metabolism during hepatic coma evidenced by 15N tracer data

    International Nuclear Information System (INIS)

    Matkowitz, R.; Hartig, W.; Junghans, P.; Jung, K.; Hirschberg, K.; Bornhak, H.

    1983-01-01

    In patients in coma hepaticum as well as in pigs with experimental hepatic coma the protein metabolism was studied under conditions of parenteral application of an amino acid diet using 15 N-glycine as tracer

  15. Two anti-angiogenic TKI-PET tracers, [11C]axitinib and [11C]nintedanib: Radiosynthesis, in vivo metabolism and initial biodistribution studies in rodents

    International Nuclear Information System (INIS)

    Slobbe, Paul; Poot, Alex J.; Haumann, Rianne; Schuit, Robert C.; Windhorst, Albert D.; Dongen, Guus A.M.S. van

    2016-01-01

    Introduction: Tyrosine kinase inhibitors (TKIs) are very attractive targeted drugs, although a large portion of patients remains unresponsive. PET imaging with EGFR targeting TKIs ([ 11 C]erlotinib and [ 18 F]afatinib) showed promise in identifying treatment sensitive tumors. The aim of this study was to synthesize two anti-angiogenic TKI tracers, [ 11 C]axitinib and [ 11 C]nintedanib, and to evaluate their potential for PET. Methods: Following successful tracer synthesis, biodistribution studies in VU-SCC-OE and FaDu xenograft bearing mice were performed. Furthermore, tracer stability studies in mice were performed employing (radio-)HPLC and LC–MS/MS techniques. For [ 11 C]nintedanib an LC–MS/MS method was developed to detect the primary carboxylic acid metabolite, resulting from methylester cleavage, in plasma and tumors, because this metabolite is postulated to be important for nintedanib efficacy. LC–MS/MS was also explored to assess the metabolic fate of [ 11 C]axitinib in vivo, since axitinib has an isomerizable double bond. Results: [ 11 C]axitinib and [ 11 C]nintedanib were successfully synthesized with 10.5 ± 2.6% and 25.6 ± 3.3% radiochemical yield (corrected for decay), respectively. Biodistribution studies only demonstrated tumor uptake of [ 11 C]nintedanib in FaDu xenografts of 1.66 ± 0.02% ID/g at 60 min p.i. In vivo stability analysis of [ 11 C]axitinib at 45 min p.i. revealed the formation of predominantly non-polar metabolites (36.6 ± 6.8% vs 47.1 ± 8.4% of parent tracer and 16.3 ± 2.1% of polar metabolites), while for [ 11 C]nintedanib mostly polar metabolites were found (70.9 ± 4.1 vs 26.7 ± 3.9% of parent tracer and only 2.4 ± 1.6 of a non-polar metabolites). No isomerization of [ 11 C]axtinib was observed in vivo; however, a sulfoxide metabolite could be detected using LC–MS/MS. For [ 11 C]nintedanib, LC–MS/MS revealed formation of the reported primary carboxylic acid metabolite when in vitro plasma incubations were performed

  16. Study on the metabolic characteristics of renal imaging agent 99mTc-PAHIDA with tracer experiment

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Wang Liuyi; Lun Mingyue

    1995-01-01

    Tracer experiment showed that 99m Tc-PAHIDA was distributed predominantly in kidney. The distribution in other tissue was in the following descending order: heart, gastrointestinal tract, liver, spleen, muscle, adipose tissue, testes, and brain. The smaller the intravenous dose, the lower the proportion of the drug was combined to plasma protein and the more the drug was distributed in kidney. Excretion of 99m Tc-PAHIDa via urine was rapid and was in its original form as shown by radiochromatography

  17. Study on the metabolism of physiological amounts of Cr(III) intragastrical administration in normal rats using activable enriched stable isotope Cr-50 compound as a tracer

    International Nuclear Information System (INIS)

    Feng, W.Y.; Ding, W.J.; Qian, Q.F.; Chai, Z.F.

    1998-01-01

    In order to study the metabolism of physiological amounts of 51 Cr (10μg/100 g of body wt.) intragastrically administered in rats, the activable enriched stable isotope Cr-50 compound Cr 2 O 3 was used as a tracer. The absorption and distribution of 51 Cr(III) in rats with time were studied. Significant 51 Cr contents were found in all the organs and tissues of interest. The kidney, liver and bone contain higher amounts of 51 Cr than others. The fact that specific activities of 51 Cr are notably high in kidney, bone, spleen and pancreas and decrease gradually with time suggests that there are tighter binding of chromium in these organs. The excretion of 51 Cr at various time intervals was also studied. Almost totally intragastrically administered dose was excreted in the feces. The increased urinary excretion of 51 Cr with time indicates that the urine-chromium is the metabolic derivative of organism. In view of the tissues distribution and excretion, it can be concluded that no more than 1% of the dose was absorbed from the gastrointestinal tract. (author)

  18. Study on the metabolic characteristics of renal imaging agent {sup 99m}Tc-PAHIDA with tracer experiment

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-05-01

    Tracer experiment showed that {sup 99m}Tc-PAHIDA was distributed predominantly in kidney. The distribution in other tissue was in the following descending order: heart, gastrointestinal tract, liver, spleen, muscle, adipose tissue, testes, and brain. The smaller the intravenous dose, the lower the proportion of the drug was combined to plasma protein and the more the drug was distributed in kidney. Excretion of {sup 99m}Tc-PAHIDa via urine was rapid and was in its original form as shown by radiochromatography.

  19. Development of a data acquisition system in form of an apparatus which is specially designed for the study of the cerebral metabolism employing radioactive tracers

    International Nuclear Information System (INIS)

    Ponchon, J.

    1988-03-01

    The subject of this thesis is the development of a data acquisition system in form of an apparatus which is specially designed for the study of cerebral metabolism employing radioactive tracers. Currently, the test is based on the continuous inhalation of gas identified with oxygen 15. After an inhalation period of 6 to 8 minutes the local brain radioactivity attains an equilibrium which corresponds to the parameters of brain metabolism. The constant measurement of the radioactivity facilitates the monitoring of the evolution of these parameters. The apparatus consists of an assemby of lead collimators in which are lodged 26 gamma ray detectors (INa probes), each one of which scans a particular brain region. For ease of use and the provision of numerous possibilities, each detector has been assigned a multichannel pulse height analyser which has been developed by ourselves in order to correspond to and to comply with the demands of our tests. They are equipped with a device which automatically corrects for dead time thereby permitting the analysis of random impulses of a rate greater than 50.000 per second with a loss of less than 1%. The multichannel analysers are connected to a central computer which by means of suitably adapted software allows the calibration of different channel of measurement, controls, the choice of the zone of interest to be integrated and the presentation of integrated results in form of graphs [fr

  20. Cardiac metabolism of 15 (p-I-123 phenyl-) pentadecanoic acid after intracoronary tracer application

    Energy Technology Data Exchange (ETDEWEB)

    Reske, S.N.; Reichmann, K.; Knopp, R.; Winkler, C.; Koischwitz, D.; Machulla, H.J.; Simon, H.

    1984-05-01

    Myocardial turnover of ..omega..-(p/sup 123/I-Phenyl-) pentadecanoic acid and release of its metabolites into the coronary sinus and peripheral blood has been studied in patients with coronary artery and valvular heart disease. After intracoronary tracer injection myocardial extraction fractions of 45-53% in control subjects were observed. In patients with coronary artery disease (CAD) normal to reduced values (34-61%) were established. Hydrophilic catabolites of I-PPA, probably p/sup 123/I-benzoic and -hippuric acid as well as small amounts of the non-metabolized tracer were found in coronary sinus and peripheral blood. Myocardial tracer uptake and clearance patterns were clearly different in normal myocardium when compared to that obtained in patients with CAD. Thus, evaluation of myocardial I-PPA metabolism might provide a new diagnostic tool for assessment of integrity of the heart's muscular metabolic function.

  1. Positron emitting tracers for studies of cocaine

    International Nuclear Information System (INIS)

    Fowler, J.S.; Gatley, S.J.; MacGregor, R.R.; Wolf, A.P.; Yu, D.W.; Dewey, S.L.; Schlyer, D.J.; Volkow, N.D.; Bendriem, B.; Logan, J.

    1990-01-01

    The use of PET to study the behavior and mechanism of action of therapeutic drugs and substances of abuse can be approached from a number of perspectives. The most common approach is to measure the effect of a drug on some aspect of metabolism and requires well characterized radiotracers whose behavior in vivo can be related to a discrete biochemical transformation. A second approach is to study the labeled drug itself. This provides information on the drug's regional distribution and kinetics as well as its pharmacological profile and metabolism. Cocaine has been labeled in different positions with carbon-11 and with fluorine-18 and the stereoisomers of cocaine have also been labeled to characterize its binding and metabolism in human and baboon brain. Regional cocaine binding as measured by PET is consistent with reversible binding to striatal dopamine reuptake sites and its time course parallels the behavioral activation of cocaine. The behaviorally inactive enantiomer (+)-cocaine is rapidly metabolized in serum preventing its entry into the brain. These PET tracers are useful in understanding the neurochemical basis of cocaine's action

  2. Tracer a application in marine outfall studies

    International Nuclear Information System (INIS)

    Genders, S.

    1979-01-01

    The applicability of radioactive and fluorescent tracers for field studies to predict or investigate waste water transport and dispersion from marine outfalls is evaluated. The application of either instantaneous or continuous tracer release, 'in situ' detection of tracers and data processing are considered. The necessity of a combined use of tracer techniques and conventional hydrographic methods for a statistical prediction of transport and dillution of waste water are pointed out. A procedure to determine an outlet distance from the coast, which satisfy bathing water criteria is outlined. (M.A.) [pt

  3. Ca-48 metabolism studies

    International Nuclear Information System (INIS)

    Van der Merwe, D.G.

    1987-03-01

    Calcium metabolism has been studied in depth physiologically and is a relatively well-understood element in biochemistry and medicine. There is still only restricted knowledge of the metabolic fate of calcium in normal and abnormal paediatric subjects. The latter is partially owing to inadequate techniques for tracing and modelling calcium pathways in children. The advent of radioactive tracers has unquestionably enhanced medical research and improved the quality of many metabolic studies. The present study was aimed at the development, promotion and justification of a new tracer technique using the stable isotope, calcium-48. The obvious advantages of such a technique are its harmlessness tothe subject, its applicability to both short- and long-term studies as well as its usefulness to the study for which it was originally motivated, viz research defining the actual relationship between a calcium-deficient diet and the occurrence of rickets in rural Black children in South Africa. Exploratory instrumental analyses were performed specifically with serum samples. This proved successful enough to develop a less specific pre-concentration technique which improved the sensitivity and reduces the cost of doing calcium-48 metabolism studies. The results of a simple metabolic study are presented whereby the scope of the technique is demonstrated in a real situation. The possibilities and limitations of double-isotope metabolic studies are discussed, particularly with regard to strontium as the second tracer

  4. Radioisotope tracers in industrial flow studies

    International Nuclear Information System (INIS)

    Easey, J.F.

    1987-01-01

    The scope of radioisotope tracer work carried out by ANSTO has involved most sectors of Australian industry including iron and steel coal, chemical, petrochemical, natural gas, metallurgical, mineral, power generation, liquified air plant, as well as port authorities, water and sewerage instrumentalities, and environmental agencies. A major class of such studies concerns itself with flow and wear studies involving industrial equipment. Some examples are discussed which illustrate the utility of radioisotope tracer techniques in these applications

  5. Tracer studies with aortic infusion result in improper tracer distribution

    International Nuclear Information System (INIS)

    Wisneski, J.A.; Brooks, G.A.; Neese, R.A.; Stanley, W.C.; Morris, D.L.; Gertz, E.W.

    1986-01-01

    It has been suggested that lactate turnover can be accurately assessed by infusing radioactive lactate tracer into the aorta and sampling blood in the vena cava. However, there may be streaming of newly infused tracer in the aorta, resulting in a nonuniform arterial specific activity (SA). Furthermore vena caval blood may not be representative of mixed venous blood. The authors examined this problem in 7 anesthetized dogs with sampling catheters in the pulmonary (PA), carotid (CA), and femoral (FA) arteries, and the superior (SVC) and inferior (IVC) vena cavi. [1- 14 C]lactate was continuously infused into the left ventricle through a catheter introduced through the femoral artery. The same SA (dpm/μmol) was found in the CA and FA, indicating adequate mixing of newly infused tracer with trace. Three dogs showed differences between SVC, IVC and PA, suggesting a mixed venous sample can not be obtained from the VC. When the catheter was moved into the aorta, wide differences in SA appeared between the CA and FA, clearly reflecting streaming of tracer. These differences also appeared in the SVC and IVC. In conclusion, adequate mixing does not occur between tracer and trace in arterial blood with aortic infusion. Further, VC sampling will not give a consistent mixed venous SA. Therefore, for practical reasons, aortic tracer infusion with vena caval sampling will lead to erroneous turnover values

  6. Study on the metabolism of 15 p-131iodine phenyl pentadecanoic acid [p-iodine phenyl pentadecanoic acid] as a tracer of free fatty acids in comparison to 1-14C-palmitic acid (C-palmitic acid)

    International Nuclear Information System (INIS)

    Sauer, J.W.

    1986-01-01

    In an animal experiment under identical metabolic influences the metabolism of a new radiopharmaceutical, 15 p- 131 iodine phenyl pentadecanoic acid (IPPA), was compared to the marked physiological fatty acid, 1- 14 C-palmitic acid (PA). The pharmacological kinetics of both tracers in tissues with widely varied turnover rates of fatty acids (heart, lung, liver, kidney, spleen, small intestine, skeletal muscle) was studied. By alkali extraction of the tissue lipids and then a chromatographic separation of the lipid fractions quantitatively comparable statements about the metabolism of PA and IPPA were made possible. The analyses of autoradiographs of the chromatographically separated lipids show a qualitatively congruous assimilation of both markers in the major lipid fractions. The quantitative evaluation shows minor differences as a result of a preferred assimilation of IPPA in triglycerides and of PA in phospholipids. The fractionated separation of tissue lipids which had been marked with PA and IPPA in vivo agrees very well with values which have been determined by other authors using 14 C- or 3 H-marked fatty acids. The close correlation of the tissue-specific metabolism kinetics of both markers makes it clear that both fatty acids are metabolized by similar, respectively, primarily identical metabolic pathyways. In conclusion, this study makes clear the extensive congruence of the metabolism kinetics of IPPA and the kinetics of the physiological palmitic acid. As a result of the presented results of the γ-radiating radiopharmaceutical IPPA as a free fatty acid analog new possibilities for the non-invasive external comprehension of lipid metabolism are opened up, whose use especially in the diagnostic of heart diseases promises success. (orig./MG) [de

  7. Inverse relationship between brain glucose and ketone metabolism in adults during short-term moderate dietary ketosis: A dual tracer quantitative positron emission tomography study.

    Science.gov (United States)

    Courchesne-Loyer, Alexandre; Croteau, Etienne; Castellano, Christian-Alexandre; St-Pierre, Valérie; Hennebelle, Marie; Cunnane, Stephen C

    2017-07-01

    Ketones (principally β-hydroxybutyrate and acetoacetate (AcAc)) are an important alternative fuel to glucose for the human brain, but their utilisation by the brain remains poorly understood. Our objective was to use positron emission tomography (PET) to assess the impact of diet-induced moderate ketosis on cerebral metabolic rate of acetoacetate (CMRa) and glucose (CMRglc) in healthy adults. Ten participants (35 ± 15 y) received a very high fat ketogenic diet (KD) (4.5:1; lipid:protein plus carbohydrates) for four days. CMRa and CMRglc were quantified by PET before and after the KD with the tracers, 11 C-AcAc and 18 F-fluorodeoxyglucose ( 18 F-FDG), respectively. During the KD, plasma ketones increased 8-fold ( p = 0.005) while plasma glucose decreased by 24% ( p = 0.005). CMRa increased 6-fold ( p = 0.005), whereas CMRglc decreased by 20% ( p = 0.014) on the KD. Plasma ketones were positively correlated with CMRa (r = 0.93; p < 0.0001). After four days on the KD, CMRa represented 17% of whole brain energy requirements in healthy adults with a 2-fold difference across brain regions (12-24%). The CMR of ketones (AcAc and β-hydroxybutyrate combined) while on the KD was estimated to represent about 33% of brain energy requirements or approximately double the CMRa. Whether increased ketone availability raises CMR of ketones to the same extent in older people as observed here or in conditions in which chronic brain glucose hypometabolism is present remains to be determined.

  8. Application of stable isotope tracer methods to studies of amino acid, protein, and energy metabolism in malnourished populations of developing countries. Report of an IAEA consultants' meeting held in Vienna, Austria, 14-16 December 1992

    International Nuclear Information System (INIS)

    1993-01-01

    A Consultants' Meeting convened by the IAEA in December 1992, made recommendations on the organization of a Co-ordinated Research Programme (CRP) using stable isotopic techniques for international comparative studies of amino acid, protein, and energy metabolism in chronically undernourished people. The CRP will use recent developments in stable isotope tracer techniques ( 13 C and 15 N) to assess the impact of infection in undernourished people on the kinetics of protein breakdown, protein synthesis, amino acid metabolism, and on the synthetic rates of selected plasma proteins. Studies will be conducted in developing countries, particularly in young children. The programme goals are to (i) elaborate methods and model protocols which can be implemented in developing countries to investigate the impact on protein metabolism of infection superimposed on chronic undernutrition; (ii) test they hypothesis that dietary requirements for protein and amino acids are related to the place of nutrition and are altered substantially when infection is superimposed on chronic undernutrition. When feasible, the primary focus on protein/amino acid metabolism will be extended to assessments of protein/energy interactions when H 2 18 O becomes more readily available and/or at research sites with indirect calorimetry equipment. The data generated should be appropriate as a basis for reevaluating amino acid/protein requirements in these populations. Refs

  9. Calcium metabolism in fluorosis and endemic genu valgum using radioactive tracer, whole body counting and radioimmunoassay

    International Nuclear Information System (INIS)

    Narasinga Rao, B.

    1979-11-01

    Endemic fluorosis with extensive skeletal changes has been reported from several parts of India. In recent years a new condition, endemic genu valgum, has been recognized in one of these areas. In both conditions osteosclerosis, particularly of the spine, has been observed, but in genu valgum the most distinctive pathology is osteoporosis in bones of the extremities and presumably as a result the ''knock knees'' that give the syndrome its name. In this project certain aspects of calcium metabolism were investigated in endemic fluorosis and genu valgum and in appropriate control subjects. Calcium kinetics were studied by intravenously injecting a tracer dose of 47 Ca and following for 10 days thereafter the concentration of the tracer in serum and excreta, as well as its total retention in the body (the latter measured by whole body counting). In addition calcium balance was measured on some of the subjects while resident in a metabolic ward. Statistical analysis of the results showed in general a higher metabolic activity of calcium in the fluorosis and genu valgum cases than in the controls (specifically, higher ''turnover'' of calcium in the blood pool and an apparently elevated bone mineralization rate). Whole body retention was somewhat greater in the patients than in the controls. Several measurements were also performed relative to blood chemistry, and in particular the serum concentration of 25-OHD 3 (a metabolite of vitamin D) was measured. There was no evidence that vitamin D deficiency played a significant role in the causation of genu valgum

  10. Structurally modified fatty acids - clinical potential as tracers of metabolism

    International Nuclear Information System (INIS)

    Dudczak, R.; Schmoliner, R.; Angelberger, P.; Knapp, F.F.; Goodman, M.M.

    1985-01-01

    Recently 15-p-iodophenyl-betamethyl-pentadecanoic acid (BMPPA) was proposed for myocardial scintigraphy, as possible probe of metabolic processes other than β-oxidation. In 19 patients myocardial scintigraphy was done after i.v. BMPPA (2 to 4 mCi). Data were collected (LAO 45 0 /14; anterior/5) for 100 minutes in the fasted patients. From heart (H) and liver (L) organ to background (BG) ratios were calculated, and the elimination (E) behavior was analyzed from BG (V. cava region) corrected time activity curves. In 10 patients plasma and urine were examined. By CHCl 3 /MeOH extraction of plasma samples (90 min. pi) both in water and in organic medium soluble catabolites were found. TLC fractionation showed that those were co-migrating, compared to standards, with benzoic acid, BMPPA and triglycerides. In urine (0 to 2h pi: 4.1% dose) hippuric acid was found. It is concluded that BMPPA is a useful agent for myocardial scintigraphy. Its longer retention in the heart compared to unbranched radioiodinated fatty acids may facilitate SPECT studies. Rate of elimination and plasma analysis indicate the metabolic breakdown of BMPPA. Yet, the complexity of the supposed mechanism may impede curve interpretation in terms of specific metabolic pathways. 19 refs., 5 tabs

  11. The use of 123I-labeled heptadecanoic acid (HDA) as metabolic tracer: preliminary report.

    Science.gov (United States)

    Dudczak, R; Kletter, K; Frischauf, H; Losert, U; Angelberger, P; Schmoliner, R

    1984-01-01

    The feasibility of using 123I-heptadecanoic acid (HDA) as a metabolic tracer was studied. Different administration routes of HDA were compared. An intracoronary bolus injection was given to calves (n = 3), and an intravenous injection was given to patients (n = 4). In addition, we examined the influence of 4-h halothane anesthesia in calves and in patients the impact of an insulin (1.5 IU/kg) + glucose (1.5 g/kg) infusion on the myocardial kinetics of HDA. Data were accumulated with a scintillation probe in calves (t = 50 min) and a gamma camera in patients (t = 70 min). In calves after an intracoronary bolus injection of HDA the myocardial time-activity curve could be described by two exponentials. The mean elimination half-time of the initial phase (ta 1/2) was 7.3 min and that of the second phase (tb 1/2) was 35 min. The ratio of the size of the initial and second component at to was 0.93. Halothane anesthesia prolonged the elimination half-times and reduced the component ratio. The biphasic behavior of the myocardial time-activity curve was maintained in patients after intravenous administration of HDA under basal conditions (initial ta 1/2 = 8.4 min). However, during infusion of insulin + glucose the decline in the myocardial activity was prolonged and monoexponential. This data shows that insulin glucose, interfering with fatty acid metabolism, influences the myocardial washout of HDA, and thus support its use as a metabolic tracer.

  12. Tracer kinetic studies of the low density lipoprotein metabolism in the fetal rat: An example for estimation of flux rates in the nonsteady state

    International Nuclear Information System (INIS)

    Plonne, D.; Schlag, B.; Winkler, L.; Dargel, R.

    1990-01-01

    To get insight into the low density lipoprotein (LDL)-apoB flux in the rat fetus near term and in the early postnatal period, homologous apoE-free 125I-labeled LDL was injected into the umbilical vein of the rat fetus immediately after Caesarean section. Since the serum LDL-apoB spontaneously declined after birth, a time-dependent two-pool model was used to calculate the flux rates in the neonate from the specific activities of LDL-apoB up to 15 h post partum. An approximate value of LDL-apoB flux in the fetus at birth was obtained by extrapolation of the kinetic data to the time of injection of the tracer. The data revealed that the turnover of LDL-apoB in the fetus (18.6 micrograms LDL-apoB/h per g body weight) exceeded that in the adult rat (0.4 microgram/h per g body weight) by at least one order of magnitude. Even 15 h after delivery, the LDL-apoB influx amounted to 2.5 micrograms/h per g body weight. The fractional catabolic rate of LDL-apoB in the fetus at term (0.39, h-1) slightly exceeded that in the adult animal (0.15, h-1) and reached the adult level within the first 3 h after birth and remained constant thereafter. In the rat fetus, LDL-apoB flux greatly exceeds that of VLDL-apoB. The data support the view of a direct synthesis and secretion of LDL, most probably by the fetal membranes

  13. Atmospheric tracer experiments for regional dispersion studies

    International Nuclear Information System (INIS)

    Heffter, J.L.; Ferber, G.J.

    1980-01-01

    Tracer experiments are being conducted to verify atmospheric transport and dispersion calculations at distances from tens to hundreds of km from pollutant sources. In one study, a 2 1/2 year sampling program has been carried out at 13 sites located 30 to 140 km from a source of 85 Kr at the Savannah River Plant in South Carolina. Average weekly concentrations as well as twice-daily concentrations were obtained. Sampling data and meteorological data, including surface, tower, and rawinsonde observations are available on magnetic tape for model verification studies. Some verification results for the Air Resources Laboratories Atmospheric Transort and Dispersion Model (ARL-ATAD) are shown for averaging periods from one week to two years

  14. Quantitative assessment of metabolic bone disease in rat models by dual tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Fumishige; Seto, Hikaru

    1989-05-01

    The usefulness of radionuclide techniques for early differential diagnosis of metabolic bone disease has been controversial. We tried to develop a new method to distinguish alterations in bone metabolism prior to radiologic changes, measuring 24-hr whole-body retention (WBR) and femoral uptake of two radiopharmaceuticals (/sup 47/Ca-chloride, /sup 99m/Tc-MDT). Control normal (C), osteoporosis (P), osteomalacia (M) and steroid-induced osteoporosis (S) were produced in 60 eight-week old Wistar male rats by means of dietary manipulation and steroid administration. Fine detail radiographs of the femurs and bone specimens were obtained over six weeks at two week intervals. Good correlation between WBR and femoral uptake of /sup 47/Ca was noted (r=0.86, p<0.01). WBR ratios of /sup 47/Ca were significantly higher in the M and S groups and were lower in the P group when compared to the C group throughout the study. WBR ratios of /sup 99m/Tc-MDP were significantly higher in the M group and were lower in the S group from the 2nd week. Fine detail radiographs analyzed by microdensitometry revealed significant osteopenia in the S, M and P groups from the 4th week. The dual tracer method was found to distinguish alterations in bone metabolism in the groups examined prior to detectable radiologic changes. (author).

  15. Analysis of metabolism of 6FDG: a PET glucose transport tracer

    Energy Technology Data Exchange (ETDEWEB)

    Muzic, Raymond F., E-mail: raymond.muzic@case.edu [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Chandramouli, Visvanathan [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Huang, Hsuan-Ming [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Wu Chunying; Wang Yanming [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Ismail-Beigi, Faramarz [Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2011-07-15

    Introduction: We are developing {sup 18}F-labeled 6-fluoro-6-deoxy-D-glucose ([{sup 18}F]6FDG) as a tracer of glucose transport. As part of this process it is important to characterize and quantify putative metabolites. In contrast to the ubiquitous positron emission tomography (PET) tracer {sup 18}F-labeled 2-fluoro-2-deoxy-D-glucose ([{sup 18}F]2FDG) which is phosphorylated and trapped intracellularly, the substitution of fluorine for a hydroxyl group at carbon-6 in [{sup 18}F]6FDG should prevent its phosphorylation. Consequently, [{sup 18}F]6FDG has the potential to trace the transport step of glucose metabolism without the confounding effects of phosphorylation and subsequent steps of metabolism. Herein the focus is to determine whether, and the degree to which, [{sup 18}F]6FDG remains unchanged following intravenous injection. Methods: Biodistribution studies were performed using 6FDG labeled with {sup 18}F or with the longer-lived radionuclides {sup 3}H and {sup 14}C. Tissues were harvested at 1, 6, and 24 h following intravenous administration and radioactivity was extracted from the tissues and analyzed using a combination of ion exchange columns, high-performance liquid chromatography, and chemical reactivity. Results: At the 1 h time-point, the vast majority of radioactivity in the liver, brain, heart, skeletal muscle, and blood was identified as 6FDG. At the 6-h and 24-h time points, there was evidence of a minor amount of radioactive material that appeared to be 6-fluoro-6-deoxy-D-sorbitol and possibly 6-fluoro-6-deoxy-D-gluconic acid. Conclusion: On the time scale typical of PET imaging studies radioactive metabolites of [{sup 18}F]6FDG are negligible.

  16. The use of Na-22 as a tracer for long-term bone mineral turnover studies

    International Nuclear Information System (INIS)

    Palmer, H.E.; Rieksts, G.A.; Palmer, R.F.; Gillis, M.F.

    1979-01-01

    Sodium-22 has been studied as a tracer for bone mineral metabolism in rats and dogs. When incorporated into bone during growth from birth to adulthood, the bone becomes uniformly tagged with Na-22, which is released through the metabolic turnover of the bone. The Na-22 not incorporated in the bone matrix is rapidly excreted within a few days when animals are fed high, but nontoxic levels of NaCl. The Na-22 tracer can be used to measure bone mineral loss in animals during space flight and in research on bone disease

  17. Nitrogen metabolism in plants using 15N as tracer. Part of a coordinated programme on the use of isotopes in fertilizer efficiency studies on grain legumes

    International Nuclear Information System (INIS)

    Pate, J.; Atkins, C.

    1978-01-01

    Techniques are described for studying the economy of carbon and nitrogen in annual nodulated legumes. Budgets for utilization of net photosynthate are constructed for cowpea (Vigna unguiculata (L) Walp.) and white lupin (Lupinus albus L.), including expenditure in respiration and dry matter accumulation of plant parts, carbon consumption in growth, respiration and export of fixed nitrogen by nodules, and the provision of recent photosynthate and earlier-fixed carbon to fruits. Sources of nitrogen to fruits are defined, and efficiencies of conversion of net photosynthate to protein of above-ground vegetative parts and of seeds are computed. Consideration is given to the timing of events associated with loss of symbiotic activity after flowering. Literature giving estimates of the respiratory requirements of nitrogen fixation by nodules is reviewed. Rates of respiration of nodules of cowpea, white lupin and pea (Pisum sativum L.) are assessed from a theoretical viewpoint, basing the estimates on ATP requirements for assimilation of N 2 into nitrogenous solutes, and published values for respiration costs in plant tissues. Expressed as CO 2 output per unit of nitrogen assimilated, these estimates greatly exceed the experimentally-observed CO 2 efflux of nodules of the species. This discrepancy is examined in relation to the capacity of nodules to fix CO 2 and the uncertainty of the in vivo requirement of nitrogenase for ATP

  18. Studies on the relationship between trace element (selenium, zinc) accumulation in hair and metabolism in body of rabbit by using 75Se and 65Zn tracer technique

    International Nuclear Information System (INIS)

    Cai Xuelin; Song Xuehua; Wu Suqiong

    1999-01-01

    In the study, the rabbit was used as experimental animal. After 2 months of feeding the diet with different levels of Se or Zn, five animals from each group were given an oral dose of Na 2 75 SeO 3 or 65 ZnSO 4 solution, respectively. The process of absorption, exertion, accumulation and transfer of isotopes to the hair were determined, and the tissues retention of 75 Se or 65 Zn were also examined at the end of the experiments. The results obtained from the measurement of radioactive change of back hair in each group animal after the oral intake of 75 Se or 65 Zn showed that the 75 Se or 65 Zn transfer to hair were fast. At the seventh and fifth day after dosing, the 75 Se or 65 Zn were determined in the down-end section and upper-end section of back hair, and the radioactivity increased with time. At the first, the radioactivity in down-end section was higher than that of the upper-end section. However, at the end of experiment the upper-end section was higher than the down-end section. The data obtained from the different measuring point indicated that the accumulation, distribution of trace element in hair was not even. there was extended process from the down-end to the upper-end of hair and accumulation in upper-end section. The content of 75 Se or 65 Zn in hair was related to the level of Se or Zn in diet. However, there were difference among the different trace elements

  19. National Biomedical Tracer Facility: Project definition study

    International Nuclear Information System (INIS)

    Heaton, R.; Peterson, E.; Smith, P.

    1995-01-01

    The Los Alamos National Laboratory is an ideal institution and New Mexico is an ideal location for siting the National Biomedical Tracer Facility (NBTF). The essence of the Los Alamos proposal is the development of two complementary irradiation facilities that combined with our existing radiochemical processing hot cell facilities and waste handling and disposal facilities provide a low cost alternative to other proposals that seek to satisfy the objectives of the NBTF. We propose the construction of a 30 MeV cyclotron facility at the site of the radiochemical facilities, and the construction of a 100 MeV target station at LAMPF to satisfy the requirements and objectives of the NBTF. We do not require any modifications to our existing radiochemical processing hot cell facilities or our waste treatment and disposal facilities to accomplish the objectives of the NBTF. The total capital cost for the facility defined by the project definition study is $15.2 M. This cost estimate includes $9.9 M for the cyclotron and associated facility, $2.0 M for the 100 MeV target station at LAMPF, and $3.3 M for design

  20. National Biomedical Tracer Facility: Project definition study

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R.; Peterson, E. [Los Alamos National Lab., NM (United States); Smith, P. [Smith (P.A.) Concepts and Designs (United States)

    1995-05-31

    The Los Alamos National Laboratory is an ideal institution and New Mexico is an ideal location for siting the National Biomedical Tracer Facility (NBTF). The essence of the Los Alamos proposal is the development of two complementary irradiation facilities that combined with our existing radiochemical processing hot cell facilities and waste handling and disposal facilities provide a low cost alternative to other proposals that seek to satisfy the objectives of the NBTF. We propose the construction of a 30 MeV cyclotron facility at the site of the radiochemical facilities, and the construction of a 100 MeV target station at LAMPF to satisfy the requirements and objectives of the NBTF. We do not require any modifications to our existing radiochemical processing hot cell facilities or our waste treatment and disposal facilities to accomplish the objectives of the NBTF. The total capital cost for the facility defined by the project definition study is $15.2 M. This cost estimate includes $9.9 M for the cyclotron and associated facility, $2.0 M for the 100 MeV target station at LAMPF, and $3.3 M for design.

  1. Sistem Pre Kompilasi Data Tracer Studi Online Ditjen Belmawa Ristekdikti (Studi Kasus: Politeknik Harapan Bersama

    Directory of Open Access Journals (Sweden)

    Very Kurnia Bakti

    2017-01-01

    Full Text Available Tracer studi merupakan salah satu upaya yang diharapkan dapat menyediakan informasi untuk mengevaluasi hasil pendidikan di Politeknik Harapan Bersama dari kuisioner yang diberikan kepada alumni. Kegiatan tracer studi ini sudah dilaksanakan secara online, namun masih terdapat kendala pada bagian sistem yang digunakan saat ini, hal tersebut menyebabkan Politeknik Harapan Bersama tidak dapat melaporkan / mengunggah hasil tracer studi kepada Ditjen Belmawa Ristekdikti, dimana form kuisioner dan data export tracer studi yang dihasilkan berbeda dengan kebutuhan seperti yang tercantum pada surat edaran No. 313/B/SE/2016 tentang pelaksanaan tracer studi di tingkat perguruan tinggi. Mengingat pentingnya tracer studi sebagai umpan balik bagi Politeknik Harapan Bersama, maka perlu solusi untuk mengatasi kekurangan sistem ini. Dengan merubah sistem yang ada dengan sistem tracer studi yang baru merupakan solusi yang tepat dalam permasalahan ini. Sistem tracer studi yang baru mampu menghasilkan data tracer studi alumni dan pengisian form kuisioner sesuai dengan standar Ditjen Belmawa Ristekdikti yang dapat diunggah sistem tracer studi ristekdikti.

  2. Rate tracer studies of heterogeneous catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Happel, J; Kiang, S

    1977-10-01

    An analysis is presented of the extent to which parameters involved in transient tracing of isotopic species in heterogeneous catalysis can be determined by experiments in which tracer concentrations are measured as a function of time. Different treatments for open and closed systems with the over-all reaction at equilibrium or irreversible were developed.

  3. Standardized 15N tracer method for the determination of parameters of the whole-body protein metabolism in clinical practice

    International Nuclear Information System (INIS)

    Junghans, P.; Jung, K.; Matkowitz, R.

    1984-01-01

    A standardized 15 N tracer method is described for the assessment of nitrogen and protein metabolism in healthy and pathological changed organisms. The method represents an isotope technical procedure for the application in clinical research and practice. The clinical preparation of the patient/proband by means of a standardized nutritional regime, the tracer administration (single dose) and the sampling (urine, blood), the 15 N tracer technique (sample chemistry, emissionsspectrometric isotope analysis) and the mathematical evaluation of 15 N tracer data are described. (author)

  4. National Biomedical Tracer Facility. Project definition study

    Energy Technology Data Exchange (ETDEWEB)

    Schafer, R.

    1995-02-14

    We request a $25 million government-guaranteed, interest-free loan to be repaid over a 30-year period for construction and initial operations of a cyclotron-based National Biomedical Tracer Facility (NBTF) in North Central Texas. The NBTF will be co-located with a linear accelerator-based commercial radioisotope production facility, funded by the private sector at approximately $28 million. In addition, research radioisotope production by the NBTF will be coordinated through an association with an existing U.S. nuclear reactor center that will produce research and commercial radioisotopes through neutron reactions. The combined facilities will provide the full range of technology for radioisotope production and research: fast neutrons, thermal neutrons, and particle beams (H{sup -}, H{sup +}, and D{sup +}). The proposed NBTF facility includes an 80 MeV, 1 mA H{sup -} cyclotron that will produce proton-induced (neutron deficient) research isotopes.

  5. National Biomedical Tracer Facility. Project definition study

    International Nuclear Information System (INIS)

    Schafer, R.

    1995-01-01

    We request a $25 million government-guaranteed, interest-free loan to be repaid over a 30-year period for construction and initial operations of a cyclotron-based National Biomedical Tracer Facility (NBTF) in North Central Texas. The NBTF will be co-located with a linear accelerator-based commercial radioisotope production facility, funded by the private sector at approximately $28 million. In addition, research radioisotope production by the NBTF will be coordinated through an association with an existing U.S. nuclear reactor center that will produce research and commercial radioisotopes through neutron reactions. The combined facilities will provide the full range of technology for radioisotope production and research: fast neutrons, thermal neutrons, and particle beams (H - , H + , and D + ). The proposed NBTF facility includes an 80 MeV, 1 mA H - cyclotron that will produce proton-induced (neutron deficient) research isotopes

  6. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers

    International Nuclear Information System (INIS)

    Russow, R.; Knappe, S.

    1999-01-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and 15 N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D 2 O, bromide and [ 15 N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers [de

  7. Concentration dynamics in lakes and reservoirs. Studies using radioactive tracers

    International Nuclear Information System (INIS)

    Gilath, Ch.

    1983-01-01

    The use of radioactive tracers for the investigation of concentration dynamics of inert soluble matter in lakes and reservoirs is reviewed. Shallow and deep stratified lakes are considered. The mechanism of mixing in lakes, flow pattern and input - output response are discussed. The methodology of the use of radioactive tracers for concentration dynamic studies is described. Examples of various investigations are reviewed. The dynamics of shallow lakes can be found and expressed in terms of transfer functions, axial dispersion models, residence time distributions and sometimes only semiquantitative information about the flow pattern. The dynamics of deep, stratified lakes is more complex and difficult to investigate with tracers. Flow pattern, horizontal and vertical eddy diffusivities, mass transfer between the hypolimnion and epilimnion are tools used for describing this dynamics. (author)

  8. 15N tracer kinetic studies on the validity of various 15N tracer substances for determining whole-body protein parameters in very small preterm infants

    International Nuclear Information System (INIS)

    Plath, C.; Heine, W.; Wutzke, K.D.; Krienke, L.; Toewe, J.M.; Massute, G.; Windischmann, C.

    1987-01-01

    Reliable 15 N tracer substances for tracer kinetic determination of whole-body protein parameters in very small preterm infants are still a matter of intensive research, especially after some doubts have been raised about the validity of [ 15 N]glycine, a commonly used 15 N tracer. Protein turnover, synthesis, breakdown, and further protein metabolism data were determined by a paired comparison in four preterm infants. Their post-conceptual age was 32.2 +/- 0.8 weeks, and their body weight was 1670 +/- 181 g. Tracer substances applied in this study were a [ 15 N]amino acid mixture (Ia) and [ 15 N]glycine (Ib). In a second group of three infants with a post conceptual age of 15 N-labeled 32.0 +/- 1.0 weeks and a body weight of 1,907 +/- 137 g, yeast protein hydrolysate (II) was used as a tracer substance. A three-pool model was employed for the analysis of the data. This model takes into account renal and fecal 15 N losses after a single 15 N pulse. Protein turnovers were as follows: 11.9 +/- 3.1 g kg-1 d-1 (Ia), 16.2 +/- 2.5 g kg-1 d-1 (Ib), and 10.8 +/- 3.0 g kg-1 d-1 (II). We were able to demonstrate an overestimation of the protein turnover when Ib was used. There was an expected correspondence in the results obtained from Ia and II. The 15 N-labeled yeast protein hydrolysate is a relatively cheap tracer that allows reliable determination of whole-body protein parameters in very small preterm infants

  9. Using isotopic tracers to assess the impact of tillage and straw management on the microbial metabolic network in soil

    Science.gov (United States)

    Van Groenigen, K.; Forristal, D.; Jones, M. B.; Schwartz, E.; Hungate, B. A.; Dijkstra, P.

    2013-12-01

    By decomposing soil organic matter, microbes gain energy and building blocks for biosynthesis and release CO2 to the atmosphere. Therefore, insight into the effect of management practices on microbial metabolic pathways and C use efficiency (CUE; microbial C produced per substrate C utilized) may help to predict long term changes in soil C stocks. We studied the effects of reduced (RT) and conventional tillage (CT) on the microbial central C metabolic network, using soil samples from a 12-year-old field experiment in an Irish winter wheat cropping system. Each year after harvest, straw was removed from half of the RT and CT plots or incorporated into the soil in the other half, resulting in four treatment combinations. We added 1-13C and 2,3-13C pyruvate and 1-13C and U-13C glucose as metabolic tracer isotopomers to composite soil samples taken at two depths (0-15 cm and 15-30 cm) from each treatment and used the rate of position-specific respired 13CO2 to parameterize a metabolic model. Model outcomes were then used to calculate CUE of the microbial community. We found that the composite samples differed in CUE, but the changes were small, with values ranging between 0.757-0.783 across treatments and soil depth. Increases in CUE were associated with a decrease in tricarboxylic acid cycle and reductive pentose phosphate pathway activity and increased consumption of metabolic intermediates for biosynthesis. Our results indicate that RT and straw incorporation promote soil C storage without substantially changing CUE or any of the microbial metabolic pathways. This suggests that at our site, RT and straw incorporation promote soil C storage mostly through direct effects such as increased soil C input and physical protection from decomposition, rather than by feedback responses of the microbial community.

  10. Metabolite-balancing techniques vs. 13C tracer experiments to determine metabolic fluxes in hybridoma cells.

    Science.gov (United States)

    Bonarius, H P; Timmerarends, B; de Gooijer, C D; Tramper, J

    The estimation of intracellular fluxes of mammalian cells using only mass balances of the relevant metabolites is not possible because the set of linear equations defined by these mass balances is underdetermined. In order to quantify fluxes in cyclic pathways the mass balance equations can be complemented with several constraints: (1) the mass balances of co-metabolites, such as ATP or NAD(P)H, (2) linear objective functions, (3) flux data obtained by isotopic-tracer experiments. Here, these three methods are compared for the analysis of fluxes in the primary metabolism of continuously cultured hybridoma cells. The significance of different theoretical constraints and different objective functions is discussed after comparing their resulting flux distributions to the fluxes determined using 13CO2 and 13C-lactate measurements of 1 - 13C-glucose-fed hybridoma cells. Metabolic fluxes estimated using the objective functions "maximize ATP" and "maximize NADH" are relatively similar to the experimentally determined fluxes. This is consistent with the observation that cancer cells, such as hybridomas, are metabolically hyperactive, and produce ATP and NADH regardless of the need for these cofactors. Copyright 1998 John Wiley & Sons, Inc.

  11. Beta-methyl[1-11C]heptadecanoic acid: a new myocardial metabolic tracer for positron emission tomography

    International Nuclear Information System (INIS)

    Livni, E.; Elmaleh, D.R.; Levy, S.; Brownell, G.L.; Strauss, W.H.

    1982-01-01

    We have tagged heptadecanoic acid with C-11 at the carboxyl group and have inserted a methyl radical in the beta position to inhibit beta oxidation of the fatty acid; we have then explored the tracer's potential as an indicator of myocardial metabolism for use with the positron tomograph. In this preliminary evaluation, biodistribution studies were made in rats and dogs, and imaging of normal and infarcted dogs was performed. At 30 min the tissue distribution studies in rats and dogs showed, respectively. 1.9% and 8.3% uptake in the heart. Sequential images of the canine heart exhibited a remarkable uptake, peaking at 16-18 min and retaining the same level of activity over the one-hour study period. Images of the heart after LAD ligation showed an area of diminished uptake corresponding to the region of infarction. Thus this agent has the basic properties required for potential use in the assessment and quantitation of free fatty-acid metabolism in the heart in a manner similar to the measurement of glucose metabolism in the brain with 2-[ 18 F]fluoro-2-deoxy-D-glucose

  12. Circulation of cerebrospinal fluid. Comparative study of various tracers

    International Nuclear Information System (INIS)

    Bok, B.; Thebault, B.; Cavailloles, F.; Aboulker, J.

    1977-01-01

    The dynamics of cerebrospinal fluid in the spinal subarachnoid space is studied by gammamyelography. There are still controversies about the ideal properties of the tracer to be used. The influence of the tracer's molecular weight on the kinetic of ascent in the medullar cerebrospinal fluid with a view to rating the criterias for choice of an available radiopharmaceutical was evaluated. Three compounds injected simultaneously through a lombar puncture were compared: indium 111 labelled transferrin, iodine 131 labelled human serum albumin and technetium 99m labelled diethylenetriaminepentaacetic acid. The individual stability of the compounds and a possible interference between them was investigated especially by electrophoretic technics. A spectrometric study showed that it is possible to simultaneously identify and count each of the isotopes included in the mixture on the detector device: an hybrid scanner. The comparison of linear activity profils collected on phantoms and on ten patients showed a similar fate of the three compounds during the first hours of the investigation studying the ascent of tracers into basal cisterns either in normal or pathological patients. It is therefore concluded that molecular weight does not influence in a detectable manner the spinal C.S.F. kinetics of the radiopharmaceuticals. This allows the use of the most convenient and best tolerated tracer from the dosimetric and toxicological stand point [fr

  13. Am-241 as a metabolic tracer for inhaled Pu nitrate in external chest counting

    International Nuclear Information System (INIS)

    Ishigure, Nobuhito; Nakano, Takashi; Enomoto, Hiroko

    2000-01-01

    The most difficult radionuclides to measure by extemal chest counting are the isotopes of plutonium (Pu). They are detected through weak emission of low energy L X-rays. The Pu treated in nuclear fuel cycle is usually accompanied with 241 Am produced from 241 Pu by β disintegration, which emits γ-rays of 60 keV with the emission rate of 0.36, being more penetrable than the L X-rays. The 241 Am could improve the detection limit of chest counting of Pu, if it being used as a metabolic tracer for Pu in lungs. It has already been shown that the 241 Am which would probably be embedded in a matrix of PuO 2 is cleared from the lungs at the same rate as the Pu for long time after intake (N. Ishigure, et al., Radiat, Prot. Dosim., 79, 133, 1998), which supports the validity of 241 Am as a tracer of inhaled Pu in external chest counting. In the present work another possible chemical form present in work places, Pu nitrate, has been investigated. The solution of Pu(NO 3 ) 4 was nebulized using a compressed-air operated nebulizer. The resultant droplets were passed through a tube with fresh air and conduced into a multi-port nose-only exposure chamber, which resulted in polydisperse aerosols of Pu(NO 3 ) 4 with 0.6 μm in AMAD. Young adult male Wistar rats, being 13 weeks old and weighing 230 g at the time of exposure were used. The exposed rats were periodically sacrificed and the radioactivity of 241 Am and 238/239/240 Pu in the autopsied lungs were measured by photon spectrometry with a NaI/CsI phoswich detector system. The activity ratio of 241 Am vs. Pu in lungs, 2.4% at the exposure, slowly decreased to 2.1% at 4 week and 2.0% at 24 weeks. However, from practical point of view, it could be concluded that 241 Am would be a valid metabolic tracer for inhaled Pu nitrate at least for half a year post inhalation, considering the detection limit for Pu in chest counting, which is much greater than the ALI of Pu and the large uncertainties due to the estimation of chest wall

  14. General circulation and tracers: studies in the Western Indian Ocean

    International Nuclear Information System (INIS)

    Jamous, Daniel

    1991-01-01

    The main question addressed in this thesis is how to best use the information obtained from hydro-biogeochemical tracer data, to study the oceanic general circulation in the Western Indian Ocean. First, a principal component analysis is performed on a historical data set. The tracers considered are temperature, salinity, density, oxygen, phosphate and silica. The method reduces the amount of data to be considered by a factor of 5. It reproduces correctly and efficiently the large-scale distributions of these oceanic properties. The analysed data are then used in a finite-difference nonlinear inverse model. The grid has a resolution of 4 deg. by 4 deg.. Dynamical as well as tracer conservation constraints are used. These constraints are well satisfied by the obtained solutions but the associated errors remain large. Additional constraints would be required in order to discuss the different solutions in more detail. Finally, a qualitative study is done on the deep distribution of helium-3. The data show several important features linked to hydrothermal input in the Gulf of Aden and on the Central Indian Ridge, and to the origin of water masses and deep circulation characteristics. However additional data are required in order to clarify the distribution of this tracer in other key areas. (author) [fr

  15. Radioisotope tracer study in an aniline production reactor

    International Nuclear Information System (INIS)

    Pant, H.J.; Yelgoankar, V.N.; Mendhekar, G.N.

    1995-01-01

    A radioisotope tracer study was carried out in an aniline production reactor to investigate the cause of poor heat transfer from tube side to shell side in an aniline production (ANPO) reactor. The results of the study indicated that more than 50% of the shell volume was reduced due to deposition of the process material (i.e. fouling) on the shell walls and may be the cause of poor heat transfer in the reactor. (author). 2 refs., 2 figs

  16. Hanford 100-N Area Tracer Study Final Report

    International Nuclear Information System (INIS)

    Kretzschmar, S.P.; Bedi, G.S.; Martinez, P.; Ervin, K.

    1996-09-01

    This document provides an engineering tracer study final report for the determination of contact time for the disinfection process at Group A Nontransient Noncommunity water treatment plant for the 100- N Water Plant (located on the Hanford Site in Richland, Washington). The purpose of this study is to determine the actual detention time within the plant clearwell, and the disinfection contact time at several clearwell effluent flow rates

  17. Mineral imbalances in farm animals and their study and diagnosis with isotopic tracers

    International Nuclear Information System (INIS)

    Underwood, E.J.

    1976-01-01

    Twenty-two mineral elements are known to be essential for animal life. These are calcium, phosphorus, sulphur, potassium, sodium, chlorine, magnesium, iron, iodine, copper, manganese, zinc, cobalt, molybdenum, selenium, chromium, tin, vanadium, fluorine, silicon, nickel and arsenic. Naturally occurring and man-made dietary imbalances of many of these elements and their interactions with other minerals are described and their functions and requirements by farm animals are outlined. The nature and importance of metabolic interactions among the mineral elements are discussed and the important concept stressed that there is no single minimum requirement or safe tolerance of a particular mineral, but a series of such minimum requirements and safe tolerances depending on the extent to which other minerals with which it interacts is present or absent from the diet. Radioactive tracer elements are shown to be of great value in the determination of mineral nutrient availability to the animal and for following mineral metabolic movements in the body. They are also shown to have considerable potential for the diagnosis of mineral imbalances. Various in vivo and in vitro techniques involving both radioactive and stable tracers developed for the early diagnosis of mineral deficiencies are described and the strengths and weaknesses of such techniques, in comparison with standard biochemical tests, are discussed. The need for further critical studies with isotopic tracers in the detection and diagnosis of mineral imbalances is emphasized. The main types of biochemical criteria used in the diagnosis of mineral deficiencies and excesses are given, with appropriate examples of their use. (author)

  18. TRACER STUDY FAKULTAS EKONOMI UNIVERSITAS NEGERI JAKARTA

    Directory of Open Access Journals (Sweden)

    Darma Rika Swaramarinda

    2014-03-01

    Full Text Available This study was conducted to identify the competencies of graduates FE UNJ waiting times based upon the profile of the work , the suitability of the first areas of work, salary and perceptions about the competence of the alumni corporation. This research is a qualitative study and the population are alumni of the Faculty of Economics who working in government agencies, private and entrepreneur and graduated from the period 2011/2012 to 2012/2013. Sample of the population is set at 10 % of the total population, and using a technique convenience sampling ( non probability sampling . The data used in this study is primary data obtained from interviews and use the questionnaire instrument. Data were analyzed using descriptive statistics by looking at the frequency distribution and the average of respondents answers regarding the competence of graduates of the Faculty of Economics UNJ. 92.8% of alumni of the Faculty of Economics working as employees of the company, 5.8 % be a teacher, others go to college and as entrepreneurs . The average waiting time for alumni FE UNJ only takes waited less than 6 months to get a job. The level of salary received at the time of the first alumni of work varies with an average of 2-3 million by 49 % and between 3 million and above by 23 % . The level of compliance competencies and job average amounted to 77 % of alumni and competence of alumni based on the user 's perception was expressed by 71 % of alumni FE UNJ have a good competence.

  19. Hanford facilities tracer study report (315 Water Treatment Facility)

    International Nuclear Information System (INIS)

    Ambalam, T.

    1995-01-01

    This report presents the results and findings of a tracer study to determine contact time for the disinfection process of 315 Water Treatment Facility that supplies sanitary water for the 300 Area. The study utilized fluoride as the tracer and contact times were determined for two flow rates. Interpolation of data and short circuiting effects are also discussed. The 315 Water Treatment Facility supplies sanitary water for the 300 Area to various process and domestic users. The Surface Water Treatment Rule (SWTR), outlined in the 1986 Safe Drinking Water Act Amendments enacted by the EPA in 1989 and regulated by the Washington State Department of Health (DOH) in Section 246-290-600 of the Washington Administrative Code (WAC), stipulates filtration and disinfection requirements for public water systems under the direct influence of surface water. The SWTR disinfection guidelines require that each treatment system achieves predetermined inactivation ratios. The inactivation by disinfection is approximated with a measure called CxT, where C is the disinfectant residual concentration and T is the effective contact time of the water with the disinfectant. The CxT calculations for the Hanford water treatment plants were derived from the total volume of the contact basin(s). In the absence of empirical data to support CxT calculations, the DOH determined that the CxT values used in the monthly reports for the water treatment plants on the Hanford site were invalid and required the performance of a tracer study at each plant. In response to that determination, a tracer study will be performed to determine the actual contact times of the facilities for the CxT calculations

  20. Studies of Tracer Dispersion and Fluid Flow in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Rage, T.

    1996-12-31

    This doctoral thesis explores the connection between the topology of a porous medium and its macroscopic transport properties and is based on computerized simulation. In porous media, both diffusion and convection contribute to the dispersion of a tracer and their combined effect is emphasized. The governing equations are solved numerically, using finite differences and Monte Carlo technique. The influence of finite Reynolds number on the outcome of echo-experiments is discussed. Comparing experiments and simulations it is found that nonlinear inertial forces lead to a visible deformation of a returned tracer at surprisingly small Reynolds numbers. In a study of tracer dispersion and fluid flow in periodic arrays of discs it is demonstrated that the mechanisms of mechanical dispersion in periodic media and in natural (non-periodic) porous media are essentially different. Measurements of the percolation probability distribution of a sandstone sample is presented. Local porosity theory predicts that this simple geometric function of a porous medium is of dominant importance for its macroscopic transport properties. It is demonstrated that many aspects of transport through fractures can be studied by using simple but realistic models and readily available computer resources. An example may be the transport of hydrocarbon fluids from the source rock to a reservoir. 165 refs., 44 figs., 1 table

  1. Studies of 15N transamination following application of various tracer substances. 1

    International Nuclear Information System (INIS)

    Schadereit, R.; Krawielitzki, K.; Herrmann, U.

    1986-01-01

    4 groups of 3 growing Wistar rats each were orally given 15 N-labelled methionine, lysine, glycine and ammonia sulphate, resp., over 10 days. Measuring the 15 N accumulation in the amino acids (AA) of the body protein, the transamination of the individual 15 N substances and thus their suitability as tracer substances for studies of N metabolism was determined. None of the tested 15 N-AA achieved a proportionate labelling of all AA of the body protein. The AA used as tracer in each case showed the highest 15 N labelling. Of the amino- 15 N detected in the animal body, about 19% were found in Met after 15 N Met application, 88% in Lys after 15 N Lys application and 50% in Gly after 15 N Gly application. After the application of 15 N-ammonia sulphate about 42% of the body amino- 15 N are apportioned to the essential and 58% to the non-essential AA. Thus, this substance produces a more proportional labelling of the essential and non-essential AA of the body protein than 15 N-Gly. The following quotas of the 15 N amounts applied were found in the AA of the animal bodies: tracer substance lysine 52%, glycine 32%, ammonia sulphate 24%, methionine 21%. After summing up the amino acid 15 N amounts in the animal body, eliminating in each case the tracer AA and taking into account the molecular weight of the AA, there was a good agreement of the intensity of the accumulation of 15 N in the individual AA, irrespective of the applied tracer substance. (author)

  2. A comparative study of the N metabolism of phytoplankton and periphyton communities in oligotrophic lakes. Part of a coordinated programme on isotopic-tracer-aided research and monitoring on agricultural residue - biological interactions in aquatic ecosystems

    International Nuclear Information System (INIS)

    Goldman, C.R.

    1982-08-01

    Limnological research at Castle Lake, CA, and Lake Tahoe, CA-NEV, USA, during the period 1977-1982 has emphasized the effects of nutrient enrichment and deficiency on primary producers. The low ambient pools of nitrogenous nutrients and their low rates of transformation have necessitated the use of isotope tracer methods ( 14 C, 15 N, 13 N). These techniques have been used in concert with physiological assays, growth bio-assays, and whole-ecosystem nitrogen enrichments. Our most significant results, to date, include: (1) Delineation of 5 algal communities which are spatially distinct yet occur in the same lake and which differ with regard to their principal sources of N; (2) Determination of the relative affinities of the above communities for the various sources of N; (3) Demonstration of the importance of internally regenerated N to phytoplankton productivity; (4) Development of sensitive methodology to utilize the short-lived radioisotope 13 N (t1/2=10 mins) for studies of denitrification and nitrate uptake in aquatic ecosystems; (5) Comparisons of a variety of physiological assays for N-deficiency in aquatic microorganisms, involving short-term and long-term experiments in containers and in an N-enriched lake. The controlled ecosystem manipulations were intended to simulate the effects of watershed disturbance on nitrogen loading in order to more accurately evaluate their potential impacts on inorganic carbon and nitrogen assimilation by natural algal communities. Our research is an experimental approach for contrasting the strategies of planktonic and benthic algae living in the same lake but differing with regard to their principal sources of nitrogen

  3. Five channel data acquisition system for tracer studies

    International Nuclear Information System (INIS)

    Narender Reddy, J.; Dhananjay Reddy, Y.; Dheeraj Reddy, J.

    2001-01-01

    Radioactive tracers are being used by many modern industries for trouble shooting, process control/quality control and optimization in the process plants. A five channel data acquisition system which has five independent scintillation detector based channels for data acquisition has been developed and made available. This system can be used for tracer studies involving Mean residence time, Resident time distribution and other similar parameters involving tracer movement. System developed can acquire data with dwell times ranging from 10 m sec to 100 sec into each channel and has a capacity to acquire data into 10K channels. Each channel electronics, has a 1x1 NaI Scintillation Detector probe, HV, AMP SCA, micro-controller based data acquisition card with independent dot matrix LCD display for visualization. Extensive use of serial bus (I 2 C, microwire) compatible devices has been incorporated in the design. Data acquisition is initiated simultaneously into all the channels. System design permits delayed/prompt data acquisition selectively. Dual counter switching technique has been employed to achieve faster dwell times for data acquisition. (author)

  4. Methods for conduct of atmospheric tracer studies at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Stone, D J.M.; Pascoe, J H [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Division

    2000-07-01

    A perfluorocarbon atmospheric tracer system has been developed to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. This report discusses the tracer release, sampling and analysis methods.

  5. Preparation of radioactive tracer for studying sediment movement

    International Nuclear Information System (INIS)

    Hussain, S.D.; Ghauri, G.A.; Qureshi, M.H.; Khan, N.A.

    1983-06-01

    In order to study the movement of sediment in harbours, estuaries and streams, artificial sediment in the form of glass is prepared. A preselected nuclide is added to the glass during its manufacture. The density and size distribution of the glass particles is method with that of the natural sediment. The activation of the artificial sediment in a reactor changes the nuclide into a radioactive isotope thereby tagging it and making it possible to trace its movement with suitable radiation detector. The method of tracer preparation is described with special reference to sadiment movement studies at Karachi harbour. (authors)

  6. 26Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi.

    1990-01-01

    Accelerator mass spectrometry (AMS) was applied for 26 Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26 Al as a tracer. When 26 Al was intraperitoneally injected into rats, a considerable amount of 26 Al was incorporated into the cerebrum after 5-35 days of the injection. (author)

  7. Study of transport in unsaturated sands using radioactive tracers

    International Nuclear Information System (INIS)

    Merritt, W.F.; Pickens, J.F.; Allison, G.B.

    1979-01-01

    A laboratory experiment was conducted to investigate the mixing that occurs as a series of labelled pulses of water are transported by gravity drainage down through a sand filled column having a water table imposed at the bottom. It also demonstrated the utility of gamma-ray emitting radioactive tracers in studying transport in unsaturated or saturated porous media. The motivation for pursuing this topic was developed from observing that the content of oxygen-18, deuterium and tritium in rainwater shows marked temporal variations whereas their concentrations below the water table in shallow ground water flow systems are generally found to show much less variation. (auth)

  8. A Comparative Uptake Study of Multiplexed PET Tracers in Mice with Turpentine-Induced Inflammation

    Directory of Open Access Journals (Sweden)

    Tingting Huang

    2012-11-01

    Full Text Available The potential value of multiplexed positron emission tomography (PET tracers in mice with turpentine-induced inflammation was evaluated and compared with 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG for glucose metabolism imaging. These PET tracers included [18F]fluoromethylcholine ([18F]FCH for choline metabolism imaging, (S-[11C]methyl-D-cysteine ([11C]DMCYS for amino acid metabolism imaging, [11C]bis(zinc(II-dipicolylamine ([11C]DPA-Zn2+ for apoptosis imaging, 2-(4-N-[11C]-methylaminophenyl-6-hydroxybenzothiazole ([11C]PIB for β amyloid binding imaging, and [18F]fluoride (18F− for bone metabolism imaging. In mice with turpentine-induced inflammation mice, the biodistribution of all the tracers mentioned above at 5, 15, 30, 45, and 60 min postinjection was determined. Also, the time-course curves of the tracer uptake ratios for inflammatory thigh muscle (IM to normal uninflammatory thigh muscle (NM, IM to blood (BL, IM to brain (BR, and IM to liver (LI were acquired, respectively. Moreover, PET imaging with the tracers within 60 min postinjection on a clinical PET/CT scanner was also conducted. [18F]FDG and 18F− showed relatively higher uptake ratios for IM to NM, IM to BL, IM to BR, and IM to LI than [18F]FCH, [11C]DPA-Zn2+, [11C]DMCYS and [11C]PIB, which were highly consistent with the results delineated in PET images. The results demonstrate that 18F− seems to be a potential PET tracer for inflammation imaging. [18F]FCH and [11C]DMCYS, with lower accumulation in inflammatory tissue than [18F]FDG, are not good PET tracers for inflammation imaging. As a promising inflammatory tracer, the chemical structure of [11C]DPA-Zn2+ needs to be further optimized.

  9. Tracer theory

    International Nuclear Information System (INIS)

    Margrita, R.

    1988-09-01

    Tracers are used in many fields of science to investigate mass transfer. The scope of tracers applications in Service of Applications Radioisotopes (S.A.R.-France) is large and concerns natural and industrial systems such as Sciences of earth: hydrology - civil engineering - Sedimentology - environmental studies. Industrial field: chemical engineering - mechanical engineering. A general tracer methodology has been developed in our laboratories from these different applications fields and this paper shows these different points of view in using tracers; our wish is that the methods used in an experimental field can be employed in an another one

  10. Coordinated programme on isotopic tracer-aided studies of the biological side effects of foreign chemical residues in food and agriculture. Study of sulfur dioxide effects on phosphorus metabolism in plants using 32-P as indicator

    International Nuclear Information System (INIS)

    Plesnicar, M.

    1977-07-01

    Exposure of bean plants to low sulphur dioxide concentrations (0.02-0.32 ppm, up to 72 hours) stimulated the incorporation of 32 P into RNA, DNA, phospholipids and the acid soluble fraction, without altering the total phosphorus content. Statistically significant 32 P increases were only observed with RNA. Uptake of 35 SO 2 (14 ppm) by bean leaves was shown to be fairly rapid and the radioactivity was translocated in the roots within 1 to 6 hours following exposure. Subcellular leaf fractions showed that the supernatant contained 60-90% of the absorbed radioactivity. The chloroplasts and microsomes showed higher 35 S content than the mitochondrial fraction. In vitro studies on pea-derived chloroplasts included photosynthetic phosphorylation and electron transport. Phosphorylation was found to be inhibited in presence of SO 2 (I 50 =3.7 mM). The nature of inhibition seems to be of the reversible-competitive type with an apparent inhibitor constant (Ki) of 1.5 mM. The electron transport system remained unaffected. It is maintained that the identification of some lesions in this study would contribute to a better understanding of the nature of the complex interactions between cultivated plants and sulphur dioxide

  11. Rate equations for tracer studies in recirculating reactors

    Energy Technology Data Exchange (ETDEWEB)

    Happel, J [Columbia Univ., New York (USA). Dept. of Chemical Engineering

    1974-10-01

    The employment of isotopic tracers is a useful technique for gaining insight into the rate controlling steps of a complex chemical reaction such as is frequently encountered in heterogeneous catalysis. An effective procedure has been to superpose tracer transfer on a reaction which is occurring under steady state conditions. If tracer transfer is employed in this fashion it is often possible to assess the individual step velocities in an assumed reaction mechanism. If transient transfer of tracer is now introduced it is possible in addition to estimate surface concentrations of chemisorbed species. The purpose of the present paper is to present the mathematical relationships involved when transfer of the tracer is not differential in the investigation. For this purpose a simple example is chosen to illustrate the various possibilities involved.

  12. Rate equations for tracer studies in recirculatinng reactors

    International Nuclear Information System (INIS)

    Happel, J.

    1974-01-01

    The employment of isotopic tracers is a useful technique for gaining insight into the rate controlling steps of a complex chemical reaction such as is frequently encountered in heterogeneous catalysis. An effective procedure has been to superpose tracer transfer on a reaction which is occurring under steady state conditions. If tracer transfer is employed in this fashion it is often possible to assess the individual step velocities in an assumed reaction mechanism. If transient transfer of tracer is now introduced it is possible in addition to estimate surface concentrations of chemisorbed species. The purpose of the present paper is to present the mathematical relationships involved when transfer of the tracer is not differential in the investigation. For this purpose a simple example is chosen to illustrate the various possibilities involved. (auth.)

  13. Integrating tracer-based metabolomics data and metabolic fluxes in a linear fashion via Elementary Carbon Modes.

    Science.gov (United States)

    Pey, Jon; Rubio, Angel; Theodoropoulos, Constantinos; Cascante, Marta; Planes, Francisco J

    2012-07-01

    Constraints-based modeling is an emergent area in Systems Biology that includes an increasing set of methods for the analysis of metabolic networks. In order to refine its predictions, the development of novel methods integrating high-throughput experimental data is currently a key challenge in the field. In this paper, we present a novel set of constraints that integrate tracer-based metabolomics data from Isotope Labeling Experiments and metabolic fluxes in a linear fashion. These constraints are based on Elementary Carbon Modes (ECMs), a recently developed concept that generalizes Elementary Flux Modes at the carbon level. To illustrate the effect of our ECMs-based constraints, a Flux Variability Analysis approach was applied to a previously published metabolic network involving the main pathways in the metabolism of glucose. The addition of our ECMs-based constraints substantially reduced the under-determination resulting from a standard application of Flux Variability Analysis, which shows a clear progress over the state of the art. In addition, our approach is adjusted to deal with combinatorial explosion of ECMs in genome-scale metabolic networks. This extension was applied to infer the maximum biosynthetic capacity of non-essential amino acids in human metabolism. Finally, as linearity is the hallmark of our approach, its importance is discussed at a methodological, computational and theoretical level and illustrated with a practical application in the field of Isotope Labeling Experiments. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. An experimental study of tracers for labelling of injection gas in oil reservoirs

    International Nuclear Information System (INIS)

    Dugstad, Oe.

    1992-01-01

    This work demonstrates the feasibility of the PMCP and PMCH as tracers in field experiments. These compounds have properties which make them as well suited for well to well studies as the more common tracers CH 3 T and 85 Kr. In an injection project carried out at the Gullfaks field in the North Sea the two PFCs verified communication between wells. This implies communication between different geological layers in the reservoir and also communication across faults within the same layers. Laboratory studies carried out have focused on the retention of the tracers in dynamic flooding experiments under conditions comparable with those in the petroleum reservoirs. Simultaneous injection of a variety of tracers has shown individual variations in tracer retention which are caused by important reservoir parameters as fluid saturation and rock properties. By proper design of field injection programs the tracers response may therefore be used to estimate fluid saturation if actual rock properties are known. 45 refs., 20 figs., 13 tabs

  15. Aligning Higher Education to Workforce Needs in Liberia: A Tracer Study of University Graduates in Liberia

    Science.gov (United States)

    Flomo, John S., Jr.

    2013-01-01

    This study investigated the congruence between higher education and the labor market from the perspectives of college graduates in Liberia. It specifically examined the alignment of the skills college students acquire in college to Liberia's labor market. The study employed a Tracer Study quantitative research methodology. Tracer study as a…

  16. Potential use of carbon-11 labeled alpha-aminoisobutyric acid (AIB) as an in vivo tracer of amino acid uptake in differing metabolic states

    International Nuclear Information System (INIS)

    Conti, P.S.; Starnes, H.F.; Brennan, M.F.

    1986-01-01

    AIB has been used as a model amino acid for the evaluation of alanine-preferring amino acid transport. Hormonal factors and starvation alter the tissue distribution of amino acids, particularly in liver and muscle. With positron emission tomography and labeling of biochemical tracers with C-11, (t1/2=20.4 min), it is now possible to study amino acid kinetics in vivo using external imaging. In order to investigate the utility of C-11 AIB as an in vivo tracer of altered tissue metabolism, C-14 AIB was studied in groups of rats with either streptozotocin-induced diabetes, insulin-induced hypoglycemia or starvation. The data suggest an increased amino acid uptake in liver in starvation, an increased uptake in muscle in response to insulin and associated hypoglycemia and decreased transport in muscle in starvation, as seen by other investigators. These results suggest that C-11 AIB may be useful as an in vivo monitor of metabolic changes in body tissues

  17. Co-ordinated research programme on application of stable isotope tracer methods to studies of amino acid, protein, and energy metabolism in malnourished populations of developing countries. Report on the second research co-ordination meeting

    International Nuclear Information System (INIS)

    1996-01-01

    The use of isotopes has revolutionized the field of human nutrition research, but has been of greatest benefit to industrialized countries. The International Atomic Energy Agency is sponsoring programmes using isotopic and related technologies in human nutrition research to address issues that are of priority to developing countries. Scientists participating in the Coordinated Research Programme (CRP) on ''Amino Acid and Protein Metabolism in Malnourished Populations of Developing Countries'' are conducting research on the interaction between infection and amino acid metabolism, particularly the potential diversion of substrates from anabolic pathways to fight infection in marginally nourished children during periods of infections. This topic is of great importance to the nutritional status of children in developing countries, who frequently or chronically have infections and who, as a consequence, may have alterations in nutrient requirements. The CRP has developed and implemented a standardized protocol for measuring leucine oxidation during infection in 8 different countries. The CRP is expected to contribute important new knowledge about interactions between protein utilization, the stresses of unhygienic environments, and infections in marginally nourished people. This information is expected to be applicable to efforts to increase efficient utilization of limited food resources in developing countries. Another highlight of the CRP is that it represents an international team of nutrition scientists who together are building nutritional biology research capabilities in developing countries. Refs, figs, tabs

  18. Co-ordinated research programme on application of stable isotope tracer methods to studies of amino acid, protein, and energy metabolism in malnourished populations of developing countries. Report on the second research co-ordination meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The use of isotopes has revolutionized the field of human nutrition research, but has been of greatest benefit to industrialized countries. The International Atomic Energy Agency is sponsoring programmes using isotopic and related technologies in human nutrition research to address issues that are of priority to developing countries. Scientists participating in the Coordinated Research Programme (CRP) on ``Amino Acid and Protein Metabolism in Malnourished Populations of Developing Countries`` are conducting research on the interaction between infection and amino acid metabolism, particularly the potential diversion of substrates from anabolic pathways to fight infection in marginally nourished children during periods of infections. This topic is of great importance to the nutritional status of children in developing countries, who frequently or chronically have infections and who, as a consequence, may have alterations in nutrient requirements. The CRP has developed and implemented a standardized protocol for measuring leucine oxidation during infection in 8 different countries. The CRP is expected to contribute important new knowledge about interactions between protein utilization, the stresses of unhygienic environments, and infections in marginally nourished people. This information is expected to be applicable to efforts to increase efficient utilization of limited food resources in developing countries. Another highlight of the CRP is that it represents an international team of nutrition scientists who together are building nutritional biology research capabilities in developing countries. Refs, figs, tabs.

  19. Plan for radionuclide tracer studies of the residence time distribution in the Wilsonville dissolver and preheater

    International Nuclear Information System (INIS)

    Jolley, R.L.; Begovich, J.M.; Brashear, H.R.

    1983-12-01

    Stimulus-response measurements using radiotracers to measure residence time distribution (RTD) and hydrodynamic parameters for the preheaters and dissolvers at the Ft. Lewis Solvent Refined Coal (SRC) and the Exxon Donor Solvent (EDS) coal conversion pilot plants are reviewed. A plan is also presented for a series of radioactive tracer studies proposed for the Advanced Coal Liquefaction Facility at Wilsonville, Alabama, to measure the RTD for the preheater and dissolvers in the SRC-I mode. The tracer for the gas phase will be 133 Xe, and 198 Au (on carbonized resin or as an aqueous colloidal suspension) will be used as the slurry tracer. Four experimental phases are recommended for the RTD tracer studies: (1) preheater; (2) dissolver with 100% takeoff; (3) dissolver with 100% takeoff and solids withdrawal; and (4) dissolver with 50% takeoff. Eighteen gas-tracer and 22 liquid-tracer injections are projected to accomplish the four experimental phases. Two to four tracer injections are projected for preliminary tests to ensure the capability of safe injection of the radiotracers and the collection of statistically significant data. A complete projected cost and time schedule is provided, including procurement of necessary components, preparation of the radiotracers, assembly and testing of tracer injection apparatus and detection systems, onsite work and tracer injections, laboratory experimentation, data analysis, and report writing

  20. Study on Radioecology and Tracer of Iodine-129

    International Nuclear Information System (INIS)

    Xiaolin, Hou

    2004-01-01

    Iodine-129 (15.7 Ma) is a naturally occurring radioisotope of iodine. The ratio of 129 I/ 127 I was estimated to be ∼ 10 -12 in the ocean and 10 -11 in the territorial environment in pre-nuclear era, releases from nuclear weapon tests have increased this ratio to ∼ 10 -10 . However, a large amount of iodine-129 was released from various nuclear facilities, and the greatest releases of 129 I are from two European reprocessing plants, especially in recent years. By 1998, 2600 Kg and 220 Kg 129 I have been discharged to the marine environment and atmosphere from La Hague (France) and Sellafield reprocessing plants, respectively. This amount is tens times larger than the total 129 I inventory in the pre-nuclear ocean and weapon test releases. Although there is no significant radiation risk for the human health at present level of 129 I, the continuously increasing production and release of 129 I make the accumulation of 129 I in the environment, immigration, cycle and long term radioecological risk should be give more attention due to its long half-life, high accumulation in human thyroid and high mobility. Iodine is a conservative element in the ocean, the large amount of iodine-129 discharged to the marine system can therefore be used as a oceanographic tracer to study the physical dispersion, mixing and circulative processes of water mass in the ocean. In Riso national laboratory, a radiochemical neutron activation analysis method was developed, using this method the radioecology and tracer of iodine-129 was studied. Some representative works are presented below. (1) Evaluation of radiation exposure of humans to iodine-129. The human and animal thyroids collected from different places, such as Tianjin in China, Gemol in Belarus, Ribe in Denmark, human urine in Denmark, seafood in China were analysed for iodine-129 concentration and 129 I/ 127 I ratio, the exposure level were compared with other places. (2) Reconstruction of radiation dose from I-131 in the

  1. Deuterium used as artificial tracer in column studies under saturated water flow conditions

    Science.gov (United States)

    Koeniger, P.; Geiges, M.; Leibundgut, Ch.

    2003-04-01

    In contrast to numerous investigations using deuterium as an environmental tracer, hydrological investigations with deuterium-labelled water are rather rare. Currently applications in groundwater studies are restricted due to increasing costs of spiking large water quantities but an application as intelligent tracer might be of advantage especially in combination with other tracers and under distinct environmental conditions. Therefore deuterium was applied as artificial tracer in column experiments that are well proved as a tool to characterise tracer behaviour in recent studies. Deuterium was tested in comparison to the more familiar conservative tracer fluorescein. Varying experimental conditions, e.g. column length (0.5, 1.0, 1.5 m), initial tracer concentration (0.01, 0.02, 0.2 mg) and flow velocity (1.5 to 6.0 m/d) were used to investigate tracer behaviour under saturated water flow conditions. Deuterium was analysed using an H/Device with chrome reduction connected to an isotope ratio mass spectrometer and expressed in relative concentrations [per mill V-SMOW]. Theoretical tracer breakthrough curves were calculated using a one dimensional dispersion model. The results indicate higher mean transport velocities and smaller dispersion for deuterium in all experiments. Due to different molecule properties that also determine the interaction of soil substrate and tracer, deuterium indicates a more conservative transport behaviour. Deuterium is non-toxic, completely soluble, chemically and biologically stable and not subject to light-influenced decay. Furthermore, it shows promise for investigations of water flow in the unsaturated zone, and of interactions of water in soil-plant-atmosphere systems. A further discussion of problems, together with possibilities for applying deuterium as an artificial tracer, will be presented.

  2. Project definition study for the National Biomedical Tracer Facility

    Energy Technology Data Exchange (ETDEWEB)

    Roozen, K.

    1995-02-15

    The University of Alabama at Birmingham (UAB) has conducted a study of the proposed National Biomedical Tracer Facility (NBTF). In collaboration with General Atomics, RUST International, Coleman Research Corporation (CRC), IsoMed, Ernst and Young and the advisory committees, they have examined the issues relevant to the NBTF in terms of facility design, operating philosophy, and a business plan. They have utilized resources within UAB, CRC and Chem-Nuclear to develop recommendations on environmental, safety and health issues. The Institute of Medicine Panel`s Report on Isotopes for Medicine and the Life Sciences took the results of prior workshops further in developing recommendations for the mission of the NBTF. The IOM panel recommends that the NBTF accelerator have the capacity to accelerate protons to 80 MeV and a minimum of 750 microamperes of current. The panel declined to recommend a cyclotron or a linac. They emphasized a clear focus on research and development for isotope production including target design, separation chemistry and generator development. The facility needs to emphasize education and training in its mission. The facility must focus on radionuclide production for the research and clinical communities. The formation of a public-private partnership resembling the TRIUMF-Nordion model was encouraged. An advisory panel should assist with the NBTF operations and prioritization.

  3. Project definition study for the National Biomedical Tracer Facility

    International Nuclear Information System (INIS)

    Roozen, K.

    1995-01-01

    The University of Alabama at Birmingham (UAB) has conducted a study of the proposed National Biomedical Tracer Facility (NBTF). In collaboration with General Atomics, RUST International, Coleman Research Corporation (CRC), IsoMed, Ernst and Young and the advisory committees, they have examined the issues relevant to the NBTF in terms of facility design, operating philosophy, and a business plan. They have utilized resources within UAB, CRC and Chem-Nuclear to develop recommendations on environmental, safety and health issues. The Institute of Medicine Panel's Report on Isotopes for Medicine and the Life Sciences took the results of prior workshops further in developing recommendations for the mission of the NBTF. The IOM panel recommends that the NBTF accelerator have the capacity to accelerate protons to 80 MeV and a minimum of 750 microamperes of current. The panel declined to recommend a cyclotron or a linac. They emphasized a clear focus on research and development for isotope production including target design, separation chemistry and generator development. The facility needs to emphasize education and training in its mission. The facility must focus on radionuclide production for the research and clinical communities. The formation of a public-private partnership resembling the TRIUMF-Nordion model was encouraged. An advisory panel should assist with the NBTF operations and prioritization

  4. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

    1999-02-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

  5. Environmental Tracers

    Directory of Open Access Journals (Sweden)

    Trevor Elliot

    2014-10-01

    Full Text Available Environmental tracers continue to provide an important tool for understanding the source, flow and mixing dynamics of water resource systems through their imprint on the system or their sensitivity to alteration within it. However, 60 years or so after the first isotopic tracer studies were applied to hydrology, the use of isotopes and other environmental tracers are still not routinely necessarily applied in hydrogeological and water resources investigations where appropriate. There is therefore a continuing need to promote their use for developing sustainable management policies for the protection of water resources and the aquatic environment. This Special Issue focuses on the robustness or fitness-for-purpose of the application and use of environmental tracers in addressing problems and opportunities scientifically, to promote their wider use and to address substantive issues of vulnerability, sustainability, and uncertainty in (groundwater resources systems and their management.

  6. Study of hydraulic parameters in leach mining using radioactive tracer

    International Nuclear Information System (INIS)

    Ahmad, M.; Tariq, J.A.; Iqbal, N.; Rafiq, M.

    2002-01-01

    Six radioactive tracer (/sup 131/I) experiments were carried out at in-situ leach mining site to study transit time of injected fluid from the injection wells to the production well along the dip, against the dip, along the diagonals and the strike. It was found that the dip of the host sandstone does not affect the movement of fluid as the same velocity was found along the dip (0.23 m/h) and against the dip (0.22 m/h). Along the diagonals, the breakthrough times for 13.75 m and 16.25 m were 54 hours and 155 hours respectively yielding velocities of 0.26 m/h and 0.1 m/h. The higher velocity is not only due to shorter distance but also due to higher porosity / injection rate. Along the strike, the breakthrough time was 29 hours (very short) for 9.25 m distance and 147 hours for 16.25 m distance. The unexpectedly high velocity along the strike for shorter distance was also due to higher injection rate in the well as the other well was accepting only small fraction of the total injection. At higher injection/production rate or higher hydraulic gradient, the breakthrough time is shorter and also the dispersion of fluid is less, consequently the leach area would be relatively small. Fluctuations of activity in some cases show the presence of fractures/cracks at certain places in the strata. The estimated porosity and hydraulic conductivity of the aquifer are 28% and 1.23 x 10-5 m/s respectively. (author)

  7. Effects of dietary nitrogen level on electrolyte and water metabolism in sheep. Part of a coordinated programme on tracer techniques in studies on the use of non-protein nitrogen in ruminants

    International Nuclear Information System (INIS)

    Juhasz, B.

    1976-05-01

    The distribution of 42 K between plasma and erythrocytes was studied in vitro, and indicated that in media containing ca. 600-900μg/100ml ammonia, the NH 4 -ion enhances the passive diffusion of K + from the erythrocytes but does not interfere with active k + influx. In vivo studies aimed to establish the factor responsible for the fall of potassium level with rising ammonia concentration in the blood. Slow intravenous infusion for 4 hrs of a dilute ammonium acetate solution caused the blood ammonia level to rise to 800μg/100ml average value, while the blood level of 42 K decreased significantly. Rise of blood ammonia was followed by decreased saliva secretion and markedly increased diuresis. The presence of ca. 800μg/100ml ammonia in the blood does not appear to interfere with the active ingression of K + into the cells but results in increased K + -elimination in urine and decreased discharge into the rumen with the saliva. The decrease in erthrocyte K + content may be considered a passive process, due to equalization of plasma and cellular concentration gradients

  8. Studies on groundwater transport in fractured crystalline rock under controlled conditions using nonradioactive tracers

    International Nuclear Information System (INIS)

    Gustafsson, E.; Klockars, C.-E.

    1981-04-01

    The purpose of the investigation has been study the following parameters along existing fractures between two boreholes: hydraulic properties of rock mass and fractures; adsorptive properties of some selected tracers during transport along fractures; dispersivity and dilution of tracers during transport in fractures; kinematic porosity of fractured bedrock. The procedure has been to determine the hydraulic properties of a rock mass by means of conventional hydraulic testing methods in 100 m deep boreholes, and to study transport mechanisms and properties of selected tracers in a selected fracture zone between two boreholes. (Auth.)

  9. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  10. Air pollution tracer studies in the lower atmosphere (citations from the NTIS data base). Report for 1964-Jan 80

    International Nuclear Information System (INIS)

    Cavagnaro, D.M.

    1980-02-01

    The cited reports cover research on the use of tracers to study lower atmospheric air pollution movements. The tracer used include sulfur hexafluoride, krypton 85, carbon 14, and other radioactive isotopes. The studies cite the results and techniques used, tracer movement from nuclear power plants, industrial stacks, urban areas, and the detectors used in their measurement

  11. sup 26 Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi

    1990-12-01

    Accelerator mass spectrometry (AMS) was applied for {sup 26}Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using {sup 26}Al as a tracer. When {sup 26}Al was intraperitoneally injected into rats, a considerable amount of {sup 26}Al was incorporated into the cerebrum after 5-35 days of the injection. (author).

  12. Tracer studies of flotation in laboratory and plant

    International Nuclear Information System (INIS)

    Niemi, A.J.; Thereska, J.; Plasari, E.; Kacaj, M.

    1992-01-01

    Froth flotation is used for the industrial extraction of valuable minerals from ores. Its progress depends on the properties of minerals being processed and on flotation practices. While flotation is basically a kinetic process, it functions industrially in continuous flow vessels whose flow patterns influence the separation effected. Radioisotope tracers have proven to be a necessary tool in the acquisition of both kinetic and flow pattern data

  13. Tracer Equivalent Latitude: A Diagnostic Tool for Isentropic Transport Studies.

    Science.gov (United States)

    Allen, Douglas R.; Nakamura, Noboru

    2003-01-01

    Area equivalent latitude based on potential vorticity (PV) is a widely used diagnostic for isentropic transport in the stratosphere and upper troposphere. Here, an alternate method for calculating equivalent latitude is explored, namely, a numerical synthesis of a PV-like tracer from a long-term integration of the advection-diffusion equation on isentropic surfaces. It is found that the tracer equivalent latitude (TrEL) behaves much like the traditional PV equivalent latitude (PVEL) despite the simplified governing physics; this is evidenced by examining the kinematics of the Arctic lower stratospheric vortex. Yet in some cases TrEL performs markedly better as a coordinate for long-lived trace species such as ozone. These instances include analysis of lower stratospheric ozone during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign and three-dimensional reconstruction of total column ozone during November-December 1999 from fitted ozone-equivalent latitude relationship. It is argued that the improvement is due to the tracer being free from the diagnostic errors and certain diabatic processes that affect PV. The sensitivity of TrEL to spatial and temporal resolution, advection scheme, and driving winds is also examined.

  14. Underground flux studies in waste basin of CIPC using natural and artificial tracers - v.1

    International Nuclear Information System (INIS)

    Minardi, P.S.P.

    1982-10-01

    Underground flux studies in waste basin of CIPC is presented, with the description of the regions and the wells, the techniques with artificial tracers and the results and conclusion, based in field campaign realized till february/82. (author)

  15. Underground flux studies in waste basin of CIPC using natural and artificial tracers - v.2

    International Nuclear Information System (INIS)

    Minardi, P.S.P.

    1982-10-01

    This report is a complement of the first volume and it has studies with natural tracers to be done on February and March/82, results and conclusions obtained with artificial tracers on March/82, every direction tests and flood course done up to october/82, besides mineralogical and complete qualitative analysis of soil obtained from sounding evidences done in mineral and industrial complex of Pocos de Caldas. (author)

  16. Tracer studies of flotation in the laboratory and in mineral processing plant

    International Nuclear Information System (INIS)

    Niemi, A.J.; Thereska, J.; Plasari, E.; Kacaj, M.

    1993-01-01

    Radioisotope tracers have a proven application for the extraction of residence time distributions and the evaluation of flotation rates in industry. This paper shows how values of the rate factor k are scaled up on the basis of flotation in the laboratory and tracer tests in plant. The procedure is illustrated by a theoretical study and by experimental data. The information obtained can be introduced into models of larger flotation systems. (author)

  17. A study plan for determining recharge rates at the Hanford Site using environmental tracers

    International Nuclear Information System (INIS)

    Murphy, E.M.; Szercsody, J.E.; Phillips, S.J.

    1991-02-01

    This report presents a study plan for estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, 36 Cl, 3 H, and 2 H/ 18 O. Atmospheric levels of 36 Cl and 3 H increased during nuclear bomb testing in the Pacific, and the resulting ''bomb pulse'' or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resulted in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, 129 I, and 99 Tc. Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Six tracer techniques (total chloride, 36 Cl, 3 H, nitrate, 129 I, and 99 Tc) will be tested on at least one site in the Quincy sand, one site in the Warden silt loam, and the background site, to determine which combination of tracers works best for a given soil type. In subsequent years, additional sites will be investigated. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial variability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other arid sites. 166 refs., 41 figs., 16 tabs

  18. Data volume of atmospheric tracer studies at Lucas Heights, NSW, Australia -1996-1997

    International Nuclear Information System (INIS)

    Clark, G.H.; Stone, D.J.M.; Pascoe, J.H.

    2000-01-01

    A perfluorocarbon atmospheric tracer system has been used to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. Tracers have been released from two locations: a laboratory vent near the ridge of the Woronora river valley and from the HIFAR research reactor ventilation system. Most studies have been conducted during the early to late morning periods when valley influences might be expected on dispersion of the tracer plume. This report summarises the meteorological and tracer air concentration data and makes comparisons with estimates from a simple gaussian dispersion model. It is intended that the data will also be used for evaluation of more elaborate wind field and atmospheric models

  19. An overview of application of bayesian classifier approach in radioactive tracer technology.case study

    International Nuclear Information System (INIS)

    El-Aseer, A.; Dawood, E.; Ben Ayad, S.; Alwerfalli, M.

    2015-01-01

    The usefulness of implementing a radioactive tracer techniques subjected to varied risk factors. Thus, the setup procedure for the application experimental techniques of radioactive tracer must be evaluated prior the decision action steps. One way of doing this, is to use Bay's theorem techniques. As there is a possibility of classifying the implemented parameters into certain catogries depending on their certainty to effect radioactive tracer technology. In this paper, the radioactive tracer experimental parameters classified accoring to Bayesian theory. Using this theory, one can study the proposed technical systems to determine the probabilities of the effectiveness of any selected parameter among the others. The classification of the applied experimental parameters into suitable or unsuitable in proposed theoretically. Ten parameters used in this experimental data were classified accordingly. The posterior is calculate from the prior and the likelihood previously determined by bayes rule.(author)

  20. Acupuncture meridians demythified. A study using the radioactive tracer method

    International Nuclear Information System (INIS)

    Simon, J.; Esquerre, J.P.; Guiraud, R.; Guiraud, G.; Lazorthes, Y.

    1988-01-01

    Radioactive trajectories can be visualized by injecting a radioactive tracer, technetium 99 m, at the site of acupuncture points. To determine the exact nature of these trajectories we performed several experiments on healthy volunteers, and our results may be summarized as follows. The target organs of technetium 99 m, and notably the thyroid gland, were always visualized. The circulating radioactivity, visible on scintiscans and confirmed by venous blood counts, was not negligible. The radioactive trajectories we observed were often divided at their starting point and did not extend along the whole length of the acupuncture meridians they might have made visible. The radioactive trajectories disappeared after venous blockade to reappear when the blockade was lifted. Finally, the radioactive trajectories obtained were very similar after injection at the acupuncture point and at a control point. These findings indicate a lymphatic and venous drainage of the radioactive tracer at the site of injection followed by transportation through the veins, rather than visualization of acupuncture meridians as suggested by some authors [fr

  1. Acupuncture meridians demythified. A study using the radioactive tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J.; Esquerre, J.P.; Guiraud, R.; Guiraud, G.; Lazorthes, Y.

    1988-07-01

    Radioactive trajectories can be visualized by injecting a radioactive tracer, technetium 99 m, at the site of acupuncture points. To determine the exact nature of these trajectories we performed several experiments on healthy volunteers, and our results may be summarized as follows. The target organs of technetium 99 m, and notably the thyroid gland, were always visualized. The circulating radioactivity, visible on scintiscans and confirmed by venous blood counts, was not negligible. The radioactive trajectories we observed were often divided at their starting point and did not extend along the whole length of the acupuncture meridians they might have made visible. The radioactive trajectories disappeared after venous blockade to reappear when the blockade was lifted. Finally, the radioactive trajectories obtained were very similar after injection at the acupuncture point and at a control point. These findings indicate a lymphatic and venous drainage of the radioactive tracer at the site of injection followed by transportation through the veins, rather than visualization of acupuncture meridians as suggested by some authors.

  2. Using biofuel tracers to study alternative combustion regimes

    International Nuclear Information System (INIS)

    Mack, J.H.; Flowers, D.L.; Buchholz, B.A.; Dibble, R.W.

    2007-01-01

    Interest in the use of alternative fuels and engines is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO 2 emissions are countered with higher nitrogen oxides (NO x ) and particulate matter (PM) emissions and higher noise. Adding oxygenated compounds to the fuel helps reduce PM emissions. However, relying on fuel alone to reduce PM is unrealistic due to economic constraints and difficult due to the emerging PM standards. Keeping peak combustion temperature below 1700 K inhibits NO x formation. Altering the combustion regime to burn at temperatures below the NO x threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous charge compression ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NO x and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to improve our combustion modeling

  3. Concentration dynamics in lakes and reservoirs, studies using radioactive tracers

    International Nuclear Information System (INIS)

    Gilath, C.

    1979-01-01

    The concentration dynamics in lakes and reservoirs through which water flows can be investigated by injecting a pulse of radioactive tracer and measuring the response at the outlet or any other point of interest inside the lake. The methodology developed for this Kind of investigation is presented. It was found that concentration dynamics in shallow reservoirs can be described by a model consisting of a time delay in series with one or two time constants. Procedures for the determination of the volumes of these regions are presented for reservoirs considered as either constant or variable parameter systems. The flow pattern in the reservoirs was investigated by measuring the response of the concentration through the lake and was analyzed in relation to the prevailing wind conditions. Wind induced currents have a dominant influence on the flow pattern. (Author) [pt

  4. Study on the flow state of groundwater by isotope tracer

    International Nuclear Information System (INIS)

    Lin Tong; Chen Jiansheng; Chen Liang

    2008-01-01

    Radioisotope logging technique is an effective method to evaluate groundwater movement. Moving with the water, the isotope tracer distributes differently in different flow states. According to the depth and time distribution of radioactivity, flow state of the groundwater can be determined. In this paper, different flow states, i.e. laminar flow, turbulent flow and mixing flow, are analyzed, and calculation of the flow velocity is discussed. Also, we discuss how to distinguish the laminar flow part and turbulent part in a mixing flow. If one judges the flow state incorrectly, the error of flow velocity will be huge, hence the importance of flow state analysis. Finally, some problems in the practical projects and measuring methods are concluded. (authors)

  5. Metabolism of diet urea in the rumen in vitro by 15N-tracer technique

    International Nuclear Information System (INIS)

    Gao Zhanfeng; Lu Lin; Wang Hongyun; Fu Cai; Huang Zhiguo; Liu Bin; Luo Xugang; Zhao Guangyong

    2011-01-01

    A completely randomized design involving 4 × 2 factorial arrangement of treatments was used to investigate effects of urea in diet (urea replaced diet CP of 0, 10%, 20% and 40%) and fermentation time (24 and 48 h) on rumen fermentation parameters and the metabolism of urea in the rumen in vitro. Results showed that different amendments of urea in diets and fermentation time had no significant effect on pH of rumen digesta (P>0.05); the concentration of NH 3 -N, however, was increased significantly from 24 to 48 h in each treatment (P undigested feed (27.83% ∼ 37.56%) > liquid-associated microbe (7.99% ∼ 10.18%) > particle-associated microbe (4.50% ∼ 6.17%). The quantity of urea in diets and fermentation time did not affect the trend of the distribution. (authors)

  6. The use of tracers in the study of the ionic permeability of the nerve

    International Nuclear Information System (INIS)

    Guinnebault, M.

    1961-01-01

    The use of the radioactive tracers 24 Na and 42 K, and the electrophysiological fine study carried out on the plant Cephalopods nervous cells have made it possible, during ten years, to study the relationships between the electrical phenomena observed during the propagation of the nervous impulse and the ionic movements which occur at the cell membrane between the intra- and extra-cellular media. In the state of rest, the nerve fibres present a certain permeability towards sodium and potassium, a permeability which allows the renewal, from the extra-cellular medium, of the cations contained in the cytoplasm. At the moment of the passage of the nervous impulse, it is possible to demonstrate a temporary increase in the permeability towards the sodium which causes the entry of Na + ions into the nerve fibre, whilst, a few milliseconds later, the increase in the potassium permeability causes the departure of an equivalent quantity of K + ions. A recovery phase follows the passage of the nervous impulse, during which the original ionic conditions are re-established. If the potassium movements can be considered as passive, the expulsion of Na + requires, on the part of the cell, the use of a part of the metabolic energy. (author) [fr

  7. Studies of radioisotope tracer technique and its applications to pesticide sciences in China

    International Nuclear Information System (INIS)

    Jia Minghong; Chen Qing; Zheng Ran

    1996-05-01

    The improper use of chemical pesticides has resulted in serious environmental problems and food pollutions, affecting the ecosystem balance and human being health. There are more and more scientists and research institutions being engaged in the area of radioisotope tracer techniques for pesticide sciences in China. So far, more than 80 labeled compounds, including insecticides, fungicides, acaricides, herbicides, metabolic intermediates, fertilizer and biological agents, etc. have been synthesized at the laboratory for application of isotopes in Institute for Application of Atomic Energy, Chinese Academy of Agricultural Sciences. Over past several years, the great achievements have been made in the researches of radioisotope tracer techniques and their applications to pesticide sciences in China, especially in the researches for isotopic labeling, residues, degradation and metabolism of pesticides in plant and animal, behavior and fate of pesticides in environment, and techniques for safe application of pesticide, and so on. The researches of radioisotope tracer techniques and their applications to pesticide sciences in China in the past years are briefly introduced. Some problems are put forward and the development in future is predicted. (1 tab.)

  8. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site characterization study

    International Nuclear Information System (INIS)

    Dombrowski, T.; Stetzenbach, K.

    1993-01-01

    This report is in two parts one for the fluorinated benzoic acids and one for the fluorinated aliphatic acids. The assumptions made in the report regarding the amount of tracer that will be used, dilution of the tracer during the test and the length of exposure (if any) to individuals drinking the water were made by the authors. These assumptions must really come from the USGS hydrologists in charge of the c-well tracer testing program. Accurate estimates of dilution of the tracer during the test are also important because of solubility limitations of some of the tracers. Three of the difluorobenzoic acids have relatively low solubilities and may not be usable if the dilution estimates are large. The toxicologist that reviewed the document agreed with our conclusion that the fluorinated benzoic and toluic acids do not represent a health hazard if used under the conditions as outlined in the report. We are currently testing 15 of these compounds, and if even if three difluorobenzoic acids cannot be used because of solubility limitations we will still have 12 tracers. The toxicologist felt that the aliphatic fluorinated acids potentially present more of a health risk than the aromatic. This assessment was based on the fact of a known allergic response to halothane anesthetic. This risk, although minimal, is known and he felt that was enough reason to recommend against their use. The authors feel that the toxicologists interpretation of this risk was overly conservative, however, we will not go against his recommendation at this time for the following reasons. First, without the aliphatic compounds we still have 12 to 15 fluorinated aromatic acids which, should be enough for the c-well tests. Second, to get a permit to use aliphatic compounds would undoubtedly require a hearing which could be quite lengthy

  9. Biodistribution of [11C] methylaminoisobutyric acid, a tracer for PET studies on system A amino acid transport in vivo

    International Nuclear Information System (INIS)

    Sutinen, E.; Jyrkkioe, S.; Groenroos, T.; Haaparanta, M.; Lehikoinen, P.; Naagren, K.

    2001-01-01

    [N-methyl- 11 C]α-Methylaminoisobutyric acid ( 11 C-MeAIB) is a potentially useful tracer for positron emission tomography (PET) studies on hormonally regulated system A amino acid transport. 11 C-MeAIB is a metabolically stable amino acid analogue specific for system A amino acid transport. We evaluated the biodistribution of 11 C-MeAIB in rats and humans to estimate the usefulness of the tracer for in vivo human PET studies, for example, on regulation of system A amino acid transport and on tumour imaging. Healthy Sprague-Dawley rats (n=14) were killed 5, 20, 40 or 60 min after the injection of 11 C-MeAIB, and the tissue samples were weighed and counted for 11 C radioactivity. Ten lymphoma patients with relatively limited tumour burden underwent whole-body (WB) PET imaging with 11 C-MeAIB. In addition, three other patients had dynamic PET scanning of the head and neck area, and the tracer uptake was quantitated by calculating the kinetic influx constants (K i values) for the tracer. In animal studies, the highest activity was detected in the kidney, pancreas, adrenal gland and intestines. In humans, the highest activity was found in the salivary glands, and after that in the kidney and pancreas, similar to the results in animal studies. Rapid uptake was also detected in the skeletal muscle. In the graphical analysis, linear plots were obtained, and the mean fractional tracer uptake values (K i ) of the parotid glands (n=3) and cervical muscles (n=3) were 0.039±0.008 min -1 and 0.013±0.006 min -1 , respectively. The K i value of the tumour (n=1) was 0.064 min -1 . Higher uptake of 11 C-MeAIB into the tumour tissue was encountered. These results encourage further 11 C-MeAIB PET studies in humans on the physiology and pathology of system A amino acid transport and on tumour detection. (orig.)

  10. The use of tracer techniques in the study of soil water flows and contaminant transport

    International Nuclear Information System (INIS)

    Reeves, A.D.; Beven, K.J.

    1990-04-01

    This report reviews the use of different types of tracers in the characterisation of soil water flows and the implications of tracer studies for modelling contaminant transport. The tracers considered are a number of different anions, stable isotopes, radioactive tracers, organic dyes, fluorocarbons, gases, solid particles and water temperature. The theoretical basis for modelling the results of tracer experiments in terms of the traditional convective-dispersion equation (CDE) is outlined. A number of alternative modelling strategies are reviewed: the mobile/immobile water extension of the CDE; the Jury Transfer Function Model (TFM); the Aggregated Mixing Zone (AMZ) model and Random Particle Tracking models. The first will form the basis of the Systeme Hydrologique Europeen (SHE) contaminant transport component. The Jury and AMZ models are both linear models and are consequently limited to applications in which the flows may be considered to be quasi-steady or repeatable. Random particle tracking models have the advantage of both flexibility and applicability to transient and spatially variable flow domains. A random particle model is being implemented on a transputer workstation at Lancaster and will be used to explore the effect of sub-grid scale complexities on effective grid-scale parameter values for distributed models such as SHE. (author)

  11. Fluctuation theorem for an optically trapped tracer in dense colloids. A simulation study

    Directory of Open Access Journals (Sweden)

    Puertas Antonio M.

    2013-03-01

    Full Text Available The work supplied by an external parabolic potential that traps one tracer in a colloidal system is studied in this work by computer simulations. The density of the bath is changed from zero up to values close to the glass transition, and the velocity varies over several decades from the linear behaviour in the low Peclet limit to the high Peclet limit. The work distributions are analyzed using the model for the isolated Brownian partice, where the friction coefficient and temperature of the medium have been fitted to reproduce the position distribution of the tracer in the trap. The overall agreement is good but not perfect. The region of negative works is studied in more detail using the predictions of the fluctuation theorem, finding good qualitative agreement with the model of the isolated Brownian particle. The present results indicate that the fluctuation theorem is of application in cases where the tracer dynamics is complex, as predicted by theoretical works.

  12. Field ionization mass spectrometry (FIMS) applied to tracer studies and isotope dilution analysis

    International Nuclear Information System (INIS)

    Anbar, M.; Heck, H.d'A.; McReynolds, J.H.; St John, G.A.

    1975-01-01

    The nonfragmenting nature of field ionization mass spectrometry makes it a preferred technique for the isotopic analysis of multilabeled organic compounds. The possibility of field ionization of nonvolatile thermolabile materials significantly extends the potential uses of this technique beyond those of conventional ionization methods. Multilabeled tracers may be studied in biological systems with a sensitivity comparable to that of radioactive tracers. Isotope dilution analysis may be performed reliably by this technique down to picogram levels. These techniques will be illustrated by a number of current studies using multilabeled metabolites and drugs. The scope and limitations of the methodology are discussed

  13. Stable nuclide tracer studies and human amino acid requirements. A summary

    International Nuclear Information System (INIS)

    Young, V.R.

    1994-01-01

    The nutritional requirements for proteins have been estimated for various age groups. The current status of knowledge concerning the quantitative needs for specific indispensable amino acids was reviewed and it was concluded that, except for infants, current values for pre-school children, school age children and healthy adults are based on limited experimental data and/or on results from nitrogen balance determinations which are open to serious question regarding their nutritional significance. A review of 13 C-labelled tracer studies carried out in MIT laboratories was undertaken to demonstrate the applicability of stable nuclide tracer studies for purposes of determining the amino acid requirements of humans. 5 refs

  14. A 82Br tracer study of coastal groundwater movement at Hat Head, NSW

    International Nuclear Information System (INIS)

    Hughes, C.; Stone, D.

    2003-01-01

    At Hat Head, NSW, on the eastern Australian coast, a radioisotope tracer study of groundwater flow in response to tidal forcing was conducted adjacent to a tidal creek. Using radiotracer, 82 Br, groundwater movement was tracked in-situ over 5 days on two occasions encompassing both neap and spring tide conditions. The tracer was injected into one borehole and gamma counts monitored from an adjacent borehole using NaI(Th) detectors. This technique maps the path of the slow moving tracer without sampling and allows the net groundwater movement to be distinguished from short term tidally driven fluxes. During the neap tide period net groundwater movement of 0.1 m/d was observed with horizontal tidal fluctuations in the order of 0.04 m. This contrasts with the tidally dominated spring tide period where net groundwater movement was negligible but tidally driven fluctuations of up to 0.13 m were observed

  15. Modelling and tracer studies of atmospheric dispersion and deposition in regions of complex topography

    International Nuclear Information System (INIS)

    Norden, C.E.

    1981-11-01

    An indium tracer aerosol generating apparatus based on an alcohol/oxygen burner, and an analytical procedure by which filter samples containing tracer material could be analysed quantitatively by means of neutron activation analysis, were developed for use in atmospheric dispersion and deposition studies. A number of series of atmospheric dispersion experiments were conducted in the Richards Bay and Koeberg- Cape Town areas. The results are given, comparing the airbone tracer concentrations measured at ground level with values predicted by means of a numerical model, utilising two to three schemes, varying in sophistication, for calculating the dispersion coefficients. Recommendations are given regarding a dispersion model and dispersion coefficients for regular use in the Koeberg area, and ways for estimating plume trajectories

  16. Potential study of bed filtration characteristics in impressed boreholes by radon tracer technique

    International Nuclear Information System (INIS)

    Litvinov, A.A.; Pinkenzon, D.B.; Makarov, M.S.; Vinarskij, M.S.

    1977-01-01

    Potential study of bed filtration characteristics in impressed boreholes by radon tracer method is shown. Effects recorded by radon tracer result from gamma radiation of short-living radon decay daughter products. During filtration of tracer through punched holes, cement stone, and rocks the products are deposited and cause a local effect for 2-3 hours. There is a shortage of short-living products in filtrated radon liquid and for some time (which is necessary for production of notable quantity of new decay products) it is practically not a gamma emitter. It is shown that the feature of effect formation governs the technique for well logging as well as interpretation of the results obtained

  17. Tumoral tracers

    International Nuclear Information System (INIS)

    Camargo, E.E.

    1979-01-01

    Direct tumor tracers are subdivided in the following categories:metabolite tracers, antitumoral tracers, radioactive proteins and cations. Use of 67 Ga-citrate as a clinically important tumoral tracer is emphasized and gallium-67 whole-body scintigraphy is discussed in detail. (M.A.) [pt

  18. Radiological safety methodology in radioactive tracer applications for hydrodynamics and environmental studies

    International Nuclear Information System (INIS)

    Suarez, R.; Badano, A.; Dellepere, A.; Artucio, G.; Bertolotti, A.

    1995-01-01

    The use of radioactive tracer techniques as control sewage disposal contamination in Montevideo Estuarine and Carrasco beach has been studied for the Nuclear Technology National Direction. Hydrodynamic models simulation has been introduced as work methodology. As well as radiological safety and radioactive material applications in the environmental studies has been evaluated mainly in the conclusions and recommendations in this report. maps

  19. Field studies of transport and dispersion of atmospheric tracers in nocturnal drainage flows

    Science.gov (United States)

    Paul H. Gudiksen; Gilbert J. Ferber; Malcolm M. Fowler; Wynn L. Eberhard; Michael A. Fosberg; William R. Knuth

    1984-01-01

    A series of tracer experiments were carried out as part of the Atmospheric Studies in Complex Terrain (ASCOT) program to evaluate pollutant transport and dispersion characteristics of nocturnal drainage flows within a valley in northern California. The results indicate that the degree of interaction of the drainage flows with the larger scale regional flows are...

  20. Regional glucose utilization and blood flow in experimental brain tumors studied by double tracer autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Kato, A.; Sako, K.; Diksic, M.; Yamamoto, Y.L.; Feindel, W.

    1985-01-01

    Coupling of regional glucose utilization (GLU) and blood flow (CBF) was examined in rats with implanted brain tumors (AA ascites tumor) by quantitative double tracer autoradiography using YF-2-fluorodeoxyglucose and 14C-iodoantipyrine. Four to 13 days after implantation, the animals were injected with the two tracers to obtain autoradiograms from the same brain section before and after the decay of YF. The autoradiograms were then analyzed by an image processor to obtain a metabolic coupling index (MCI = GLU/CBF). In the tumor, high GLU and low CBF were uncoupled to give a high MCI which implied anerobic glycolysis. In large tumors, the CBF was even lower. In the peri-tumoral region, GLU was reduced and reduction was lowest around the larger tumors. CBF in the peri-tumoral region was also reduced, but this reduction became less as the distance from the tumor margin increased. The GLU and CBF of white matter was little influenced by the presence of tumors except for some reduction in these values in relation to the larger tumors. The MCI in the tumor was higher than in the cortex of the same as well as the opposite hemisphere. These findings indicate that the metabolism and blood flow of the tumor and surrounding brain are variable and directly related to tumor size.

  1. Double-tracer autoradiographic study of protein synthesis and glucose consumption in rats with focal cerebral ischemia

    DEFF Research Database (Denmark)

    Christensen, Thomas; Balchen, T; Bruhn, T

    1999-01-01

    A double-tracer autoradiographic method for simultaneous measurement of regional glucose utilization (rCMRglc) and regional protein synthesis (PS) in consecutive brain sections is described and applied to study the metabolism of the ischemic penumbra 2 h after occlusion of the middle cerebral...... artery (MCAO) in rats. In halothane anesthesia, the left middle cerebral artery was permanently occluded. Two hours after MCAO an i.v. bolus injection of 14C-deoxyglucose and 3H-leucine was given and circulated for 45 min. Two sets of brain sections were processed for quantitative autoradiography....... Neighboring brain sections exposed an X-ray film (3H-insensitive), and a 3H-sensitive for determination of rCMRglc and PS, respectively. Sections for PS determination were washed in trichloroacetic acid (TCA) prior to film exposure in order to remove 14C-deoxyglucose and unincorporated 3H-leucine. Regional...

  2. Nested Tracer Studies In Catchment Hydrology: Towards A Multiscale Understanding of Runoff Generation and Catchment Funtioning

    Science.gov (United States)

    Soulsby, C.; Rodgers, P.; Malcolm, I. A.; Dunn, S.

    Geochemical and isotopic tracers have been shown to have widespread utility in catch- ment hydrology in terms of identifying hydrological source areas and characterising residence time distributions. In many cases application of tracer techniques has pro- vided insights into catchment functioning that could not be obtained from hydromet- ric and/or modelling studies alone. This paper will show how the use of tracers has contributed to an evolving perceptual model of hydrological pathways and runoff gen- eration processes in catchments in the Scottish highlands. In particular the paper will focus on the different insights that are gained at three different scales of analysis; (a) nested sub-catchments within a mesoscale (ca. 200 square kilometers) experimen- tal catchment; (b) hillslope-riparian interactions and (c) stream bed fluxes. Nested hydrometric and hydrochemical monitoring within the mesoscale Feugh catchment identified three main hydrological response units: (i) plateau peatlands which gener- ated saturation overland flow in the catchment headwaters, (ii) steep valley hillslopes which drain from the plateaux into (iii) alluvial and drift aquifers in the valley bottoms. End Member Mixing Analysis (EMMA) in 8 nested sub-catchments indicated that that stream water tracer concentrations can be modelled in terms of 2 dominant runoff pro- cesses; overland flow from the peat and groundwater from the drift aquifers. Ground- water contributions generally increased with catchment size, though this was moder- ated by the characteristics of individual sub-basins, with drift cover being particularly important. Hillslope riparian interactions were also examined using tracers, hydromet- ric data and a semi-distributed hydrological model. This revealed that in the glaciated, drift covered terrain of the Scottish highlands, extensive valley bottom aquifers effec- tively de-couple hillslope waters from the river channel. Thus, riparian groundwater appears to significantly

  3. Experimental design for estimating parameters of rate-limited mass transfer: Analysis of stream tracer studies

    Science.gov (United States)

    Wagner, Brian J.; Harvey, Judson W.

    1997-01-01

    Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or subsurface water where flow is stagnant or slow moving. We present a methodology for (1) evaluating and comparing alternative stream tracer experiment designs and (2) identifying those combinations of stream transport properties that pose limitations to parameter estimation and therefore a challenge to tracer test design. The methodology uses the concept of global parameter uncertainty analysis, which couples solute transport simulation with parameter uncertainty analysis in a Monte Carlo framework. Two general conclusions resulted from this work. First, the solute injection and sampling strategy has an important effect on the reliability of transport parameter estimates. We found that constant injection with sampling through concentration rise, plateau, and fall provided considerably more reliable parameter estimates than a pulse injection across the spectrum of transport scenarios likely encountered in high-gradient streams. Second, for a given tracer test design, the uncertainties in mass transfer and storage-zone parameter estimates are strongly dependent on the experimental Damkohler number, DaI, which is a dimensionless combination of the rates of exchange between the stream and storage zones, the stream-water velocity, and the stream reach length of the experiment. Parameter uncertainties are lowest at DaI values on the order of 1.0. When DaI values are much less than 1.0 (owing to high velocity, long exchange timescale, and/or short reach length), parameter uncertainties are high because only a small amount of tracer interacts with storage zones in the reach. For the opposite conditions (DaI ≫ 1.0), solute

  4. Tryptophan metabolism in breast cancers: molecular imaging and immunohistochemistry studies

    International Nuclear Information System (INIS)

    Juhász, Csaba; Nahleh, Zeina; Zitron, Ian; Chugani, Diane C.; Janabi, Majid Z.; Bandyopadhyay, Sudeshna; Ali-Fehmi, Rouba; Mangner, Thomas J.; Chakraborty, Pulak K.; Mittal, Sandeep; Muzik, Otto

    2012-01-01

    Introduction: Tryptophan oxidation via the kynurenine pathway is an important mechanism of tumoral immunoresistance. Increased tryptophan metabolism via the serotonin pathway has been linked to malignant progression in breast cancer. In this study, we combined quantitative positron emission tomography (PET) with tumor immunohistochemistry to analyze tryptophan transport and metabolism in breast cancer. Methods: Dynamic α-[ 11 C]methyl-L-tryptophan (AMT) PET was performed in nine women with stage II–IV breast cancer. PET tracer kinetic modeling was performed in all tumors. Expression of L-type amino acid transporter 1 (LAT1), indoleamine 2,3-dioxygenase (IDO; the initial and rate-limiting enzyme of the kynurenine pathway) and tryptophan hydroxylase 1 (TPH1; the initial enzyme of the serotonin pathway) was assessed by immunostaining of resected tumor specimens. Results: Tumor AMT uptake peaked at 5–20 min postinjection in seven tumors; the other two cases showed protracted tracer accumulation. Tumor standardized uptake values (SUVs) varied widely (2.6–9.8) and showed a strong positive correlation with volume of distribution values derived from kinetic analysis (P < .01). Invasive ductal carcinomas (n = 6) showed particularly high AMT SUVs (range, 4.7–9.8). Moderate to strong immunostaining for LAT1, IDO and TPH1 was detected in most tumor cells. Conclusions: Breast cancers show differential tryptophan kinetics on dynamic PET. SUVs measured 5–20 min postinjection reflect reasonably the tracer's volume of distribution. Further studies are warranted to determine if in vivo AMT accumulation in these tumors is related to tryptophan metabolism via the kynurenine and serotonin pathways.

  5. A Study Plan for Determining Recharge Rates at the Hanford Site Using Environmental Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E. M.; Szecsody, J. E.; Phillips, S. J.

    1991-02-01

    This report presents a study plan tor estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. The prediction of contaminant movement or transport is one aspect of performance assessment and an important step in the remedial investigation/feasibility study (RI/FS) process. In the past, recharge has been characterized by collecting lysimeter data. Although lysimeters can generate important and reliable data, their limitations include 1) fixed location, 2) fixed sediment contents, 3) edge effects, 4) low rates, and 5) relatively short duration of measurement. These limitations impact the ability to characterize the spatial distribution of recharge at the Hanford Site, and thus the ability to predict contaminant movement in the vadose zone. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, {sup 36}CI, {sup 3}H, and {sup 2}H/{sup 18}O. Atmospheric levels of {sup 36}CI and {sup 3}H increased during nuclear bomb testing in the Pacific, and the resulting "bomb pulse" or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resu~ed in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, {sup 129}I, and {sup 99}Tc. The radionuclides, in particular, reached a well-defined atmospheric peak in 1945. Atmospheric releases of {sup 129}I and {sup 99}Tc were greatly reduced by mid-1946, but nitrogen oxides continued to be released from the uranium separations facilities. As a result, the nitrate concentrations probably peaked in the mid-1950s, when the greatest number of separations facilities were operating

  6. Characterization of crushed tuff for the evaluation of the fate of tracers in transport studies in the unsaturated zone

    International Nuclear Information System (INIS)

    Polzer, W.L.; Fuentes, H.R.; Raymond, R.; Bish, D.L.; Gladney, E.S.; Lopez, E.A.

    1987-03-01

    Results of field-scale (caisson) transport studies under unsaturated moisture and steady and nonsteady flow conditions indicate variability and a lack of conservation of mass in solute transport. The tuff materials used in that study were analyzed for the presence of tracers and of freshly precipitated material to help explain the variability and lack of conservation of mass. Selected tuff samples were characterized by neutron activation analysis for tracer identification, by x-ray diffraction for mineral identification, by petrographic analysis for identification of freshly precipitated material, and by x-ray fluorescence analysis for identification of major and trace elements. The results of these analyses indicate no obvious presence of freshly precipitated material that would retard tracer movement. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of sorbing and nonsorbing tracers on the tuff at some locations (even cesium at the 415-cm depth) and not at others suggests variability in transport. 15 refs., 14 figs., 9 tabs

  7. Tracer techniques for the study of host-parasite relations

    International Nuclear Information System (INIS)

    Mendgen, K.

    1975-01-01

    Autoradiographic techniques have been used to study the interaction of many facultative and obligate parasites, including viruses. After feeding the host plant with labelled substrates, labelled material accumulates in the infected cells and seems to penetrate into structures of the parasite. After labelling the parasite, its influence on the host may be studied. We use this technique to study the interaction of host (bean) and parasite (bean rust) during the infection process. After infection with uredospores labelled with tritiated orotic acid, the radioactivity is retained almost completely within the young haustorium at 22 h after inoculation. This may indicate a very small influence of the parasite on its compatible host. In incompatible host-parasite combinations, the infection process proceeds in a different way. The use of autoradiographic techniques to compare combinations of varying compatibilities will be discussed. (author)

  8. Disinfection Contact Time study plan (100-N Area tracer protocol). Revision 1

    International Nuclear Information System (INIS)

    Kretzschmar, S.P.; Bedi, G.S.; Martinez, P.; Ervin, K.

    1996-07-01

    Bechtel Hanford, Inc. will prepare an Engineering Tracer Study Protocol for the determination of contact time for the disinfection process at Group A Non-transient Non-community water treatment plant for the 100-N Water Plant at the Hanford Site in Richland, Washington. Included in this report are the results of a study that determine the actual detention time within the plant clearwell, and thus the disinfection contact time at several clearwell effluent flow rates

  9. UKAEA code of practice for tracer and irradiation studies involving the use of volunteers

    International Nuclear Information System (INIS)

    Pritchard, J.N.; Morgan, A.

    1987-06-01

    The subject is discussed under the following headings: 1) General considerations in volunteer studies (informed consent, beneficial objectives, recruitment from within or without the workforce, records, compensation, codes of practice, confidentiality etc.) 2) Tracer and irradiation studies approval committee, (terms of reference, membership, dose limitations, assessment of chemical toxicity, procedure for submitting proposals) 3) Obtaining a project licence 4) Conduct of volunteer experiments 5) The use of non-authority volunteers. (U.K.)

  10. Carbon-14 tracer studies in rat-liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate

    International Nuclear Information System (INIS)

    Muellhofer, G.; Schwab, A.; Mueller, C.; Stetten, C. von; Gruber, E.

    1977-01-01

    The intracellular events in the metabolic pathway of gluconeogenesis from lactate and pyruvate in liver tissue were assumed to be understood. Nevertheless the results of several 14 C-tracer experiments gave rise to the postulation of still unknown intracellular interactions under this condition. A contribution was made to the solution of this problem by using different 14 C labelled tracers such as [1- 14 C]lactate or pyruvate and [2- 14 C]lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]-octanoate in perfusion experiments with livers from rats under conditions of gluconeogenesis from lactate and pyruvate. The 14 C labelling patterns of intracellular metabolities such as malate, citrate, phosphoenolpyruvate, phosphoglycerate and newly synthesized glucose were analysed under different conditions. A comparison with values calculated by using metabolic models based on the generally accepted concepts of intracellular interactions showed some fundamental discrepancies which justify the postulation. (orig./MG) [de

  11. Fallout Radionuclides as Tracers in Southern Alps Sediment Studies

    Science.gov (United States)

    Carey, A. E.; Karanovic, Z.; Dibb, J. E.

    2005-12-01

    The primary geologic processes shaping the landscape are physical and chemical weathering and the transport of solids by erosion. As part of our studies on the coupling between physical erosion and chemical weathering, we have determined depositional and erosional processes in New Zealand's tectonically active, rapidly uplifting Southern Alps, specifically focusing on the Hokitika River watershed. The South Island watersheds we are studying are subject to extreme orographic precipitation (as high as 7-12 m annually) and high landslide frequency, but have modest topography due to the rapid erosion. In concert with our studies of chemical weathering and physical erosion, we have used the atmospherically-delivered radionuclides of 7Be, 137Cs and 210Pbexcess to determine the relative magnitude of particle residence time in the high elevation Cropp and Whitcombe subwatersheds and the rates of sedimentation. One- and two-box modeling with 7Be and 210Pbexcess was used to determine soil and sediment residence times. Residence time of fine suspended particles is short and particles can travel the length of the river during a single storm, probably due to the short duration, high-intensity rainfalls which produce rapidly moving, steep flood waves. The readily detected peak of 137Cs activity in Cropp terrace and Hokitika gorge soils yielded sedimentation rates of 0.06-0.12 cm yr-1. At the Cropp terrace, inventory models of 210Pbexcess yield soil accumulation rates significantly less than those determined using the 137Cs activity peak. We attribute the differences to overestimation of 210Pbexcess in surface soils and to contrasting fallout fluxes, geochemical behavior and radionuclide contents of sedimenting materials. Total inventories of 210Pbexcess in soils greatly exceed the expected direct atmospheric deposition, suggesting that lateral transport of this nuclide occurs within the watershed. At the Hokitika gorge, all nuclides studied yielded similar sedimentation rates

  12. Study of the mineralization of coral implanted in vivo by radioactive tracers

    International Nuclear Information System (INIS)

    Irigaray, J.L.; Sauvage, T.; Oudadesse, H.; El Fadl, H.; Lefaivre, J.; Barlet, J.P.; Trevers, S.; Tixer, H.

    1993-01-01

    Coral has been used for the last ten years as bone substitution in the body because of its mechanical and osteoconductor properties. Primary studies have shown, for the first time, the quantitative behaviour of the atomic components. A biocoral implanted 'in vivo' was studied by some physical method of analysis. The natural biocorals used are the calcium carbonated exoskeletons built by Madrepian coral polyps. Neutron activation analysis showed that initial coral, essentially CaCO 3 , becomes a new material which has a mineral composition close to that of bone. The calcification mechanism of this implant was studied by using radioactive tracers. The tracer kinetics of calcium biomaterial have been established in the blood circuit and its use was shown by the organism for skeleton mineralization. (author) 8 refs.; 6 figs.; 4 tabs

  13. Isotopic tracer aided studies of fenvalerate residues in stored rice

    International Nuclear Information System (INIS)

    Varca, L.M.; Sanchez, T.E.; Magallona, E.D.

    1990-01-01

    Following application of 14 C-fenvalerate to milled rice and paddy rice at a concentration of 0.33 mg/kg, only insignificant losses were measured after 9 months. Distribution patterns in surface, methanol extractable and bound residues were studied. Paddy rice contained less extractable residues than milled rice, with the major part being found in the husk. Bound residues in both milled and paddy rice decreased also with length of storage; as much as 30% was found as bound residues after nine months. Cooking reduced the insecticide residues in milled rice by 33-40% and residues in paddy rice by 58%. (author). 8 refs, 1 fig., 4 tabs

  14. studies on iron availability in Egyptian soils using tracer technique

    International Nuclear Information System (INIS)

    Gad allah, A.M.A.

    1984-01-01

    four experiments were conducted to study the available fe in some egyptian soils, representing alluvial,, calcareous, and sandy soils, including the following:1) estimation of soil available iron using different chemical methods as well as E-value and evaluated against biological method. 2) differentiation of iron as Fe 2+ and Fe 2+ in some selected egyptian soils by using the modified method (charlot,1966). 3) determination of total Fe in soil using neutron activation analysis. 4) the relative importance of Fe-diffusion in egyptian soils under different treatments

  15. Radioactive tracer applications in the study of flow reactors. 4

    International Nuclear Information System (INIS)

    Thyn, J.; Hovorka, J.

    1975-01-01

    Response curves of gas streaming through the jet fluidized bed of a granular material in a rotary-jet pilot reactor were measured for a number of gas flow rates. A mathematical model of the gas residence time distribution was designed. Good agreement of the mathematical model with the experiments permits determining the ratio of streaming through the fluidized bed in form of bubbles of a different size. The measured values were evaluated as the distribution density of the gas residence time (age) at the outlet, the distribution function of the internal gas age in the device, and the so-called intensity function. The gas was labelled by a rapid injection of the radioactive 85 Kr and the response was studied by specially connected Geiger-Mueller counters placed inside the device, immediately above the granular material bed. (author)

  16. Ion exchange in ultramarine blue. Studies using radioactive tracers (1963)

    International Nuclear Information System (INIS)

    Goenvec, H.

    1963-05-01

    A study has been made of the exchange reaction between the constituent sodium in ultramarine blue, and silver in the form of a silver nitrate solution; an attempt hat been made to define the influence of the solvent of the silver nitrate on the kinetics of the exchange reaction. Five solvents have been used: water, methanol, ethanol, n-propanol and acetone. The reaction rates are controlled by a diffusion process inside the ultramarine grains, whatever the solvent used. It seems that the solvated ionic radius of the diffusing ion is one of the factors influencing the rate of reaction. Furthermore, the solvated ionic radius varies with temperature; this variation is different for each solvent and should explain the differences observed in the activation energies. (author) [fr

  17. National Biomedical Tracer Facility (NBTF). Project definition study: Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Lagunas-Solar, M.C.

    1995-02-15

    This report describes a five-year plan for the construction and commissioning of a reliable and versatile NBTF facility for the production of high-quality, high-yield radioisotopes for research, biomedical, and industrial applications. The report is organized in nine sections providing, in consecutive order, responses to the nine questions posed by the U.S. Department of Energy in its solicitation for the NBTF Project Definition Study. In order to preserve direct correspondence (e.g., Sec. 3 = 3rd item), this Introduction is numbered {open_quotes}0.{close_quotes} Accelerator and facility designs are covered in Section 1 (Accelerator Design) and Section 2 (Facility Design). Preliminary estimates of capital costs are detailed in Section 3 (Design and Construction Costs). Full licensing requirements, including federal, state, and local ordinances, are discussed in Section 4 (Permits). A plan for the management of hazardous materials to be generated by NBTF is presented in Section 5 (Waste Management). An evaluation of NBTF`s economic viability and its potential market impact is detailed in Section 6(Business Plan), and is complemented by the plans in Section 7 (Operating Plan) and Section 8 (Radioisotope Plan). Finally, a plan for NBTF`s research, education, and outreach programs is presented in Section 9 (Research and Education Programs).

  18. Joint DOE/NRC field study of tracer migration in the unsaturated zone

    International Nuclear Information System (INIS)

    Nyhan, J.; Polzer, W.; Essington, E.; Cokal, E.; Lane, L.; Lopez, E.; Stallings, E.; Walker, R.

    1986-03-01

    The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86

  19. Contribution of radioactive tracers to sediment transport study in fluvial flows

    International Nuclear Information System (INIS)

    Wilson Junior, G.

    1995-01-01

    The uses of radioactive tracers in sediment transport studies are presented in this report to evidence the importance of: Open channel researches, to describe field applications in waterways; Simultaneous utilization of classical methods and radiotracer techniques, in fluvial and estuarine environments; Development of radiotracers techniques applied in dynamic sedimentology. The report illustrated with some experiments carried out in Brazil and France, in open channel and natural flows. (author). 5 refs, 4 figs

  20. Determination of the lysosomal role in tumor accumulation of 67Ga by dual-tracer studies

    International Nuclear Information System (INIS)

    Ando, Atsushi; Ando, Itsuko; Hiraki, Tatsunosuke; Yamada, Norihisa; Hisada, Kinichi

    1989-01-01

    The lysosomal role in tumor accumulation of 67 Ga was determined by dual-tracer( 67 Ga and 46 Sc) studies. It became clear that 67 Ga essentially did not accumulate in the tumor lysosome, and that the lysosome did not play a major role in tumor accumulation of 67 Ga. In addition, it was revealed that tumor lysosome was hardly disrupted at all in some phases of fractionation procedures. (author)

  1. Dynamic study of an anaerobic reactor in pilot plant scale using radioactive tracer

    International Nuclear Information System (INIS)

    Pinto, A.M.F.; Moreira, R.M.; Chernicharo, C.A.L.

    1995-01-01

    The use of flow traces is a common practice in hydrodynamic studies. However chemical tracers have some shortcomings, such as the need of sampling, analysis and possible interferences with the delicate biological processes taking place within the reactor. Thus a radiotracer, Br 82 has been chosen for this purpose. The advantages of this radioisotope are its energetic gamma emission which can be easily detected outside the reactor walls, its solubility and lack of adsorption, besides having a convenient half-life and being easily produced is small nuclear reactors. The tracer responses to instantaneous injections at the reactor entrance were used to determine the resistance time and the mixing patterns of the reactors. The normalized residence time distributions were fitted to mathematical models by a least-squares subroutine. The axial dispersion model and the tanks-in-series model have been used, thus allowing the determination of the dispersion coefficient and the Peclet Number. (author). 5 refs, 4 figs, 1 tab

  2. Experiences of simulated tracer dispersal studies using effluent discharges at Tarapur aquatic environment

    International Nuclear Information System (INIS)

    Sudheendran, V.; Baburajan, A.; Sawane, Pratibha; Rao, D.D.; Hegde, A.G.

    2007-01-01

    The nuclear complex in Tarapur, Maharashtra is a multi facility nuclear site comprising of power reactors and research facilities. Each facility has independent liquid effluent discharge line to Arabian Sea. Experimental studies were conducted to evaluate dilution factors in the aquatic environment using liquid effluent releases as tracer from one of the facilities. 3 H and 137 Cs radioisotopes present in the routine releases were used as simulated tracer nuclides. The dilution factors(D.F) observed for tritium were in the range of 20-20000 in a distance range of 10 m to 1500 m respectively and for 137 Cs the D.F. were in the range of 50 to 900 over a distance range of 10-200 m. The paper describes the analytical methodology and sampling scenarios and the results of dilution factors obtained for Tarapur aquatic environment. (author)

  3. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    Energy Technology Data Exchange (ETDEWEB)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-05-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references.

  4. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    International Nuclear Information System (INIS)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-01-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references

  5. Study of the effect of Chinese medicine on calcium absorption with isotopic tracer technique

    International Nuclear Information System (INIS)

    Hu, S.M.; Mao, X.Y.; Feng, W.Y.; OY, H.; Wang, M.; Xu, D.D.; Zhang, F.; Chai, Z.F.

    2005-01-01

    The present work was undertaken to study the effect of Chinese medicine on calcium absorption. Female Wistar rats, 3 months old, weighing 250-275 g, were randomly divided into ten groups of 5 rats each. The rats were individually housed in stainless steel metabolic cages in an environmentally controlled room (temperature, 20 degree C; relative humidity, 30%-60%; reversed light : dark cycle, 12:12 hr). Isotopic tracer technique was conducted to study the absorption of calcium acetate and calcium acetate + Chinese medicine in rats. The two calcium supplements were irradiated in a nuclear reactor for 4.95 d at neutron flux of φ=6.1 x 10 13 n/cm 2 ·s. Then they were prepared from concentrated 47 Ca solution (10 mg/ml) with cyclodextrin. The animals received oral doses of 25 mg calcium as calcium acetate or calcium acetate + Chinese medicine via an intragastric gavage. The animals were fasted overnight preceding and food was resumed 3 hrs after the gavage. Blood, heart, lung, liver, spleen, stomach, kidney, small intestine, large intestine and femur samples of the rats were taken upon sacrifice at 0.5, 1, 2, 4, 12, 24, 48, 72, 120, 168 hrs after dosing and assayed for 47 Ca. Urine and feces samples were collected separately after dosing and assayed for 47 Ca. The radioactivity of the samples was counted with a high pure Ge detector and a PC-based Ortec MCA. Its energy resolution was l.85 keV at 1332.5 keV and the relative detection efficiency was 30 %. The dead time was controlled within 10 % to reduce the count loss. Weighed 47 CaCO 3 was used as reference materials. A big distance between the samples and detector was kept to overcome the geometric effect caused by different shape and size of the samples. The gamma energy spectra were analyzed with a multipurpose gamma ray spectrum analysis software package. The parameters were evaluated by means of general linear model, using analysis of covariance with SAS 6.12 for Windows. The results showed that peroral 47 Ca was

  6. STRATEGIES FOR QUANTIFYING PET IMAGING DATA FROM TRACER STUDIES OF BRAIN RECEPTORS AND ENZYMES.

    Energy Technology Data Exchange (ETDEWEB)

    Logan, J.

    2001-04-02

    A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.

  7. Metabolism of 3H- and 14C-labeled glutamate, proline, and alanine in normal and adrenalectomized rats using different sites of tracer administration and sampling

    International Nuclear Information System (INIS)

    Said, H.M.; Chenoweth, M.; Dunn, A.

    1989-01-01

    Alanine, glutamate and proline labeled with 14C and 3H were infused into fasted normal and adrenalectomized rats. Alanine was administered by the A-V mode (arterial administration-venous sampling), and glutamate and proline by both the A-V and V-A (venous administration-arterial sampling) modes. The kinetics of 14C alanine and 14C glutamate differed markedly from those of the tritium-labeled compounds, but there was little difference in the kinetics of 3H and 14C proline. The replacement rate calculated from the A-V mode for glutamate was about half that obtained in the V-A mode, but there was little difference with proline. The masses of the amino acids (total content of amino acids in the body) were calculated from the washout curves of the tritium-labeled compounds after the infusion of tracer was terminated. The masses for the normal rats were 407 mumol/kg for alanine, 578 mumol/kg for glutamate and 296 mumol/kg for proline. The so-called distribution spaces calculated conventionally from total masses and the amino acid concentrations in plasma are much greater than the volume of the body, reflecting the fact that amino acid concentrations in tissues greatly exceed those in plasma. Adrenalectomy markedly affected the kinetics of the three amino acids, and their replacement rates were greatly reduced. The proline and glutamate masses were reduced by at least one half, while that of alanine was unchanged. Adrenalectomy markedly reduced the conversion of proline to glutamate. The hydrocortisone regimen used in this study restored the metabolism of alanine and glutamate to normal, but had no effect on that of proline

  8. Application of tracer techniques in studies of sediment transport in Vietnam

    International Nuclear Information System (INIS)

    Hai, P.S.; Quang, N.H.; Xuan, N.M.; Chuong, P.N.; Hien, P.Z.

    1997-01-01

    As a consequence of intensive erosion processes typical of the humid tropical one, as well as of human activities destroying tropical forests, grasslands and protective mangrove swamps, etc, most navigable estuaries in Vietnam suffer seriously from sedimentation. In order to maintain the necessary depth for the 7.000 ton vessels entering and leaving ports, a large amount of money is spent annually on dredging operation. A lot of hydraulic and sedimentary surveys were carried out in the past by different groups of researchers. However, owing to the complexity of sediment processes in estuarine areas under the hydrometeorological conditions typical of the southwest Pacific, the use of just any modelling approach is not suitable. In many cases, the conclusions inferred from mathematical models have been the controversial matter. The tracer techniques, which have been employed in the country since 1991, have provided a very efficient tool to obtain a dynamic idea of sediment transport. Many investigations of bedload transport using Sc-46 labelled glass and Ir-192 glass as radioactive tracers were carried out from 1992 to 1996 at Haiphong harbour area. Bedload transport rates under effect of northeast monsoon and southeast monsoon at 5 zones located on both sides of the navigation channel were estimated. In bedload transport studies, apart from conventional methods for assessment of transport thickness, a new method using the ratio of photoelectric peak to Compton region of spectra acquired directly on the sea bed was put forward and applied. The influence of dredging materials at two dumping sites under different tidal phases on in fill rate in the access channel was assessed by radioactive tracers. The qualitative and quantitative information on sediment transport at some experimental sites given by tracers was used by modelling specialists who have undertaken hydraulic and sedimentary surveys in this region

  9. Circulation of the medullary cerebrospinal fluid. Comparative study of various tracers

    International Nuclear Information System (INIS)

    Bok, B.; Thebault, B.; Cavailloles, F.; Aboulker, J.

    Gammamyelography is used to study the circulation of the cerebrospinal fluid in the perimedullary sub-arachoid spaces. Many radioactive preparations have been proposed for this examination which is designed to show up all dynamic perturbations of the CSF flux. Of the criteria governing the choice of tracer some importance given has been to the molecular diffusion constant of the preparation, iodinated albumine seeming the most suitable in this respect. An attempt was made to estimate the influence of molecular weight on the tracer kinetics by comparing three preparations injected simultaneously: indium 111-labelled siderophilline of M.W. above 100,000; iodine 131-labelled human serum albumine of MW around 70,000; sup(99m)Tc-labelled DTPA, a chelate of low molecular weight. The results showed no detectable influence of the molecular weight of these preparations on their intraspinal kinetics in the time taken for the examination. In practice this work justifies the use of the preparation most convenient and least harmful from the dosimetric viewpoint for the isotope and from the antigenic toxicological viewpoint for the tracer, which means that the replacement of iodinated albumine by indium-111 DTPA for example should be possible at least at the medullary level [fr

  10. The use of bromine as a tracer for studying infiltrations in mining processes

    International Nuclear Information System (INIS)

    Diaz, F; Andonie, O; Rojas, X

    2003-01-01

    The impact of mining activity on underground water is becoming increasingly important because of the scarcity of the resource and due to the different use if there is water under the mining. Once the resource is affected the source of infiltration should be identified in all the processes and systems that are involved in the production system in order to take the appropriate preventive or remedial measures, which should also be the most efficient ones. Tracers play an important role in studying infiltration from mining processes to underground bodies of water. Natural chemical and isotopic tracers can identify the hydrogeological setting and help to establish supported hypotheses about the possible origin of the infiltrations. After the different ideas about the processes or systems that could be infiltrated are presented, the application of additional artificial tracers can resolve any doubts This work presents the use of bromine as a tracer for such studies, because of its specific characteristics as a good tracer in water with low interaction in porous surroundings, generally, and its determination by Neutron Activation Analyzers (NAA) due to its low limits of detection and the technique's precision and accuracy for use at reasonable costs. Given that for this type of study a large number of samples are necessary and that it should be carried out in a time period that does not surpass the duration of the process (a few months), a change had to be made in the methodology usually used for the NAA, which included taking a fraction of significantly less sample while meeting the power requirements for differentiating small changes in concentrations between samples. With this modification a larger number of samples can be irradiated in available positions for these purposes in the RECH-1 and the requirements for the number of samples and response time can be met. After the practical performance of this modification, a comparison between both methodologies was carried

  11. Studies of liver-specific metabolic reactions with 15N. 1

    International Nuclear Information System (INIS)

    Hirschberg, K.; Jung, K.; Faust, H.; Matkowitz, R.

    1987-01-01

    The 15 N tracer technique was used to investigate liver-specific reactions (urea and hippurate synthesis) for studying the metabolism in the healthy and damaged pig liver. After [ 15 N]ammonium chloride administration the tracer distribution on non-protein compounds of serum and urine was followed. Blood samplings before and after liver passage rendered possible a direct analysis of the [ 15 N]ammonium metabolism. The thioacetamide-induced liver damage was used as model for an acute liver intoxication. The capacity for urea synthesis was not influenced by means of this noxious substance, but the metabolism of amino acids and hippuric acid. The considerably depressed excretion of [ 15 N]hippurate seems to be a suitable indicator of liver disfunction. (author)

  12. Application of tracer techniques to the study of trematode infections: Pathological and epidemiological aspects

    International Nuclear Information System (INIS)

    Nansen, P.

    1976-01-01

    Liver fluke and blood fluke infections cause heavy losses in animal production. The infections are characterized by a concomitant anaemia and dysproteinaemia. A review is made of radioisotopic tracer studies which have contributed to an understanding of the dynamic processes underlying the blood changes. Such studies have provided important information about the activity of the parasites, for example, how they cause disease and how they influence animal production. Radioisotopic techniques have also been utilized in the study of free-living fluke larvae. A brief outline of principles and fields if investigations within this area is given. (author)

  13. Fifty years of radiochemical tracers

    International Nuclear Information System (INIS)

    Evans, E.A.

    1992-01-01

    During the past 50 years radiochemical tracers, usually in the form of isotopically labelled organic compounds, have been essential tools to further advance our knowledge at the frontiers of a great variety of scientific developments in the life sciences. This plenary lecture reviews necessarily selected highlights in the synthesis and applications of such radiochemical tracers. Included are examples where important advances, made possible by using radiochemicals, have contributed to improving the quality of life on this planet. The principal radioisotopes involved, 14 C, 3 H, 35 S, 32 P, 125 I, are all relatively safe to handle and are commercially available at maximum theoretical specific activity (carrier free). The compounds labeled with these radioisotopes are used in many fields of research which include biosynthesis and biotechnology studies, cell biology, drug metabolism, clinical research and environmental applications, and are briefly reviewed. (author). 55 refs

  14. Hydrophilic and lipophilic radiopharmaceuticals as tracers in pharmaceutical development: In vitro – In vivo studies

    International Nuclear Information System (INIS)

    Terán, Mariella; Savio, Eduardo; Paolino, Andrea; Frier, Malcolm

    2005-01-01

    Scintigraphic studies have been performed to assess the release, both in vitro and in vivo, of radiotracers from tablet formulations. Four different tracers with differing physicochemical characteristics have been evaluated to assess their suitability as models for drug delivery. In-vitro disintegration and dissolution studies have been performed at pH 1, 4 and 7. In-vivo studies have been performed by scintigraphic imaging in healthy volunteers. Two hydrophilic tracers, ( 99m Tc-DTPA) and ( 99m Tc-MDP), and two lipophilic tracers, ( 99m Tc-ECD) and ( 99m Tc-MIBI), were used as drug models. Dissolution and disintegration profiles, differed depending on the drug model chosen. In vitro dissolution velocity constants indicated a probable retention of the radiotracer in the formulation. In vivo disintegration velocity constants showed important variability for each radiopharmaceutical. Pearson statistical test showed no correlation between in vitro drug release, and in vivo behaviour, for 99m Tc-DTPA, 99m Tc-ECD and 99m Tc-MIBI. High correlation coefficients were found for 99m Tc-MDP not only for in vitro dissolution and disintegration studies but also for in vivo scintigraphic studies. Scintigraphic studies have made a significant contribution to the development of drug delivery systems. It is essential, however, to choose the appropriate radiotracers as models of drug behaviour. This study has demonstrated significant differences in release patterns, depending on the model chosen. It is likely that each formulation would require the development of a specific model, rather than being able to use a generic drug model on the basis of its physicochemical characteristics

  15. Seepage studies through hydraulic structures and their foundations by inactive and radio tracers

    International Nuclear Information System (INIS)

    Ansari, Azher; Mahajan, N.M.; Kamble, M.D.

    1977-01-01

    In the last ten years extensive efforts have been made by the Central Water and Power Research Station, Pune to study seepage by means of inactive and radiotracers. Various inactive tracers like electrolytes and organic dyes and radiotracers like 82 Br and 3 H in the form of tritiated water have been used for location of source of seepage. Different techniques like borehole dilution, in situ detection at various observation points and analysis of water samples in liquid scintillation spectrometer in the laboratory have been employed to suit the field conditions. Some typical studies at river valley projects indicating the techniques are enumerated. (author)

  16. Tracer Study Lulusan Program Studi Bimbingan dan Konseling Universitas Negeri Gorontalo

    Directory of Open Access Journals (Sweden)

    Maryam Rahim

    2018-01-01

    Full Text Available Penelitian ini diharapkan dapat memperbaiki dan meningkatkan kualitas pengelolaan program studi Bimbingan dan Konseling Universitas Negeri Gorontalo berdasarkan informasi yang diperoleh melalui tracer study. Secara khusus, penelitian ini dilakukan untuk memperoleh informasi tentang lulusan, yang meliputi (1 rata-rata masa tunggu lulusan, (2 jenis pekerjaan yang ditekuni, dan (3 tanggapan terhadap pengguna lulusan. Permasalahan penelitian ini adalah: (1 berapa rata-rata masa tunggu lulusan?, (2 jenis pekerjaan apa yang ditekuni lulusan?, dan (3 bagaimana tanggapan pengguna terhadap lulusan?. Anggota populasi dalam penelitian ini berjumlah 408 orang, dari jumlah tersebut 58% (238 orang dijadikan sebagai anggota sampel dengan menggunakan cluster sampling. Indikator penelitian meliputi: (1 rata-rata masa tunggu lulusan, (2 jenis pekerjaan yang ditekuni lulusan, dan (3 tanggapan pengguna terhadap lulusan. Pengumpulan data dilakukan dengan menggunakan instrumen tracer study. Data yang terkumpul dianalisis secara kuantitatif. Hasil penelitian menunjukkan: (1 rata-rata masa tunggu lulusan adalah 3 bulan; (2 jenis pekerjaan yang ditekuni lulusan terdiri dari 13 kategori yakni (a Guru BK (PNS sebanyak 27.31%; (b Guru BK (Non PNS sebanyak 50.00%; (c Guru PAUD sebanyak 0.84%; (d Guru TK sebanyak 5.04%; (e Guru SD sebanyak 4.20%; (f Guru SLB sebanyak 0.42%; (g Pegawai instansi pemerintah sebanyak 2.52%; (h Pegawai perusahaan sebanyak 0.84%; (i Dosen sebanyak 1.26%; (j Dosen luar biasa sebanyak 1.26%; (k Wirausaha sebanyak 3.78%; (l Anggota DPR sebanyak 0.42%; (m dan lain-lain sebanyak 2.10%; dan (3 tanggapan pengguna terhadap lulusan, yang menyangkut: (a  integritas (etika dan moral = 89.60 (sangat baik; (b keahlian berdasarkan bidang ilmu (profesionalisme = 82.92 (baik; (c bahasa Inggris = 67.89 (cukup; (d penggunaan teknologi informasi = 81.71 (baik; (e komunikasi = 84.06 (baik; (f kerjasama tim = 85.04 (sangat baik; dan (g pengembangan diri = 83.83 (baik

  17. Application of tracer gas studies in the optimal design of soil vapor extraction systems

    International Nuclear Information System (INIS)

    Marley, M.C.; Cody, R.J.; Polonsky, J.D.; Woodward, D.D.; Buterbaugh, G.J.

    1992-01-01

    In the design of an optimal, cost effective vapor extraction system (VE) for the remediation of volatile organic compounds (VOCs), it is necessary to account for heterogeneities in the vadose zone. In some cases, such as those found in relatively homogeneous sands, heterogeneities can be neglected as induced air flow through the subsurface can be considered uniform. The subsurface conditions encountered at many sites (soil/bedrock interfaces, fractured bedrock) will result in preferential subsurface-air flow pathways during the operation of the VES. The use of analytical and numerical compressible fluid flow models calibrated and verified from parameter evaluation tests can be utilized to determine vadose zone permeability tensors in heterogeneous stratifications and can be used to project optimal, full scale VES performance. Model-derived estimations of the effect of uniform and/or preferential air flow pathways on subsurface induced air flow velocities can be enhanced, confirmed utilizing tracer gas studies. A vadose zone tracer gas study entails the injection of an easily detected, preferably inert gas into differing locations within the vadose zone at distances away from the VES extraction well. The VES extraction well is monitored for the detection of the gas. This is an effective field methodology to qualify and quantify the subsurface air flow pathways. It is imperative to gain an understanding of the dynamics of the air flow in the soils and lithologies of each individual site, and design quick and effective methodologies for the characterization of the subsurface to streamline remediation costs and system operations. This paper focuses on the use of compressible fluid flow models and tracer gas studies in the enhancement of the design of vapor extraction systems

  18. Study of leak detection using tracers in a bottling plant in Mexico

    International Nuclear Information System (INIS)

    Vizuet Gonzalez, Jorge; Reyes Jimenez, Jose Luis; Molina, Gustavo

    2005-01-01

    The Instituto Nacional de Investigaciones Nucleares (ININ), Mexico, promoted the application of different techniques, involving the use of radioactive materials. Among them is the use of radioactive material as a medium tracer in the industry. Below is a study of locating leaks in ducts collectors of process water of a bottling plant which had several problems, one was not able to stop production, and most important, having to disassemble a large amount of machinery and equipment, in order to open the floor and locate the leak

  19. Study of the mineralization of coral implanted in vivo by radioactive tracers

    International Nuclear Information System (INIS)

    Irigaray, J.L.; Sauvage, T.; Oudadesse, H.; El Fadl, H.

    1993-01-01

    Coral may be used as a substitution biomaterial to the bone graft, due to its physico-chemical and architectural properties. The coral, after its implantation 'in vivo' reaches a mineral composition and crystalline structure comparable to those of a bone. The calcification mechanism of this implant is studied using 45 Ca as radioactive tracer. The atomic elements contained in the initial coral were analysed in function of the time spent in the body, by marking the calcium and the strontium contained in its structure. (K.A.) 8 refs.; 6 figs.; 4 tabs

  20. Studies of liver-specific metabolic reactions with /sup 15/N. 1. Metabolism of /sup 15/N-ammonium chloride in pigs

    Energy Technology Data Exchange (ETDEWEB)

    Hirschberg, K; Jung, K; Faust, H; Matkowitz, R

    1987-07-01

    The /sup 15/N tracer technique was used to investigate liver-specific reactions (urea and hippurate synthesis) for studying the metabolism in the healthy and damaged pig liver. After (/sup 15/N)ammonium chloride administration the tracer distribution on non-protein compounds of serum and urine was followed. Blood samplings before and after liver passage rendered possible a direct analysis of the (/sup 15/N)ammonium metabolism. The thioacetamide-induced liver damage was used as model for an acute liver intoxication. The capacity for urea synthesis was not influenced by means of this noxious substance, but the metabolism of amino acids and hippuric acid. The considerably depressed excretion of (/sup 15/N)hippurate seems to be a suitable indicator of liver disfunction.

  1. Simplification of complex kinetic models used for the quantitative analysis of nuclear magnetic resonance or radioactive tracer studies

    International Nuclear Information System (INIS)

    Schuster, R.; Schuster, S.; Holzhuetter, H.-G.

    1992-01-01

    A method for simplifying the mathematical models describing the dynamics of tracers (e.g. 13 C, 31 P, 14 C, as used in NMR studies or radioactive tracer experiments) in (bio-)chemical reaction systems is presented. This method is appropriate in the cases where the system includes reactions, the rates of which differ by several orders of magnitude. The basic idea is to adapt the rapid-equilibrium approximation to tracer systems. It is shown with the aid of the Perron-Frobenius theorem that for tracer systems, the conditions for applicability of this approximation are satisfied whenever some reactions are near equilibrium. It turns out that the specific enrichments of all of the labelled atoms that are connected by fast reversible reactions can be grouped together as 'pool variables'. The reduced system contains fewer parameters and can, thus, be fitted more easily to experimental data. Moreover, the method can be employed for identifying non-equilibrium and near-equilibrium reactions from experimentally measured specific enrichments of tracer. The reduction algorithm is illustrated by studying a model of the distribution of 13 C-tracers in the pentose phosphate pathway. (author)

  2. Fluorinated tracers for imaging cancer with positron emission tomography

    International Nuclear Information System (INIS)

    Couturier, Olivier; Chatal, Jean-Francois; Luxen, Andre; Vuillez, Jean-Philippe; Rigo, Pierre; Hustinx, Roland

    2004-01-01

    2-[ 18 F]fluoro-2-deoxy-d-glucose (FDG) is currently the only fluorinated tracer used in routine clinical positron emission tomography (PET). Fluorine-18 is considered the ideal radioisotope for PET imaging owing to the low positron energy (0.64 MeV), which not only limits the dose rate to the patient but also results in a relatively short range of emission in tissue, thereby providing high-resolution images. Further, the 110-min physical half-life allows for high-yield radiosynthesis, transport from the production site to the imaging site and imaging protocols that may span hours, which permits dynamic studies and assessment of potentially fairly slow metabolic processes. The synthesis of fluorinated tracers as an alternative to FDG was initially tested using nucleophilic fluorination of the molecule, as performed when radiolabelling with iodine-124 or bromide-76. However, in addition to being long, with multiple steps, this procedure is not recommended for bioactive molecules containing reactive groups such as amine or thiol groups. Radiochemical yields are also often low. More recently, radiosynthesis from prosthetic group precursors, which allows easier radiolabelling of biomolecules, has led to the development of numerous fluorinated tracers. Given the wide availability of 18 F, such tracers may well develop into important routine tracers. This article is a review of the literature concerning fluorinated radiotracers recently developed and under investigation for possible PET imaging in cancer patients. Two groups can be distinguished. The first includes ''generalist'' tracers, i.e. tracers amenable to use in a wide variety of tumours and indications, very similar in this respect to FDG. These are tracers for non-specific cell metabolism, such as protein synthesis, amino acid transport, nucleic acid synthesis or membrane component synthesis. The second group consists of ''specific'' tracers for receptor expression (i.e. oestrogens or somatostatin), cell

  3. Using rare earth element tracers and neutron activation analysis to study rill erosion process

    International Nuclear Information System (INIS)

    Li Mian; Li Zhanbin; Ding Wengfeng; Liu Puling; Yao Wenyi

    2006-01-01

    Spatially averaged soil erosion data provide little information on the process of rill erosion. The dynamically varied data on the temporal and spatial distributions in the rill erosion process are needed to better understand the erosion process and reveal its innate characteristics. The objectives of this study were to examine the feasibility and effectiveness of rare earth element (REE) tracers and the neutron activation analysis (NAA) method on the study of the rill erosion process and to reveal quantitatively the relationships and characteristics of temporal and spatial distributions of sediment yield in rill erosion. Four REEs were used to study the changeable process of rill erosion at 4 slope positions. Four water inflow rates were applied to a 0.3x5 m soil bed at 3 slopes of 10.5%, 15.8% and 21.2% in scouring experiments. All of the runoff was collected in the experiment. Each sample was air-dried and well mixed. Then 20 g of each sample was sieved through 100-mesh and about a 50 mg sample was weighed for analysis of the four elemental compositions by NAA. Results indicate that the REE tracers and NAA method can be used to not only quantitatively determine soil erosion amounts on different slope segments, but also to reveal the changeable process of rill erosion amount. All of the relative errors of the experimental results were less than 25%, which is considered satisfactory on the study of rill erosion process

  4. Using rare earth element tracers and neutron activation analysis to study rill erosion process

    Energy Technology Data Exchange (ETDEWEB)

    Li Mian [Yellow River Institute of Hydraulic Research, Yellow River Conservancy Commission, Key Laboratory of Yellow River Sediment Research of Ministry of Water Resources, Shunhelu 45, Zhengzhou, Henan 450003 (China)]. E-mail: hnli-mian@163.com; Li Zhanbin [Xi' an University of Technology, Xi' an, Shaanxi 710048 (China); Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100 (China); Ding Wengfeng [Institute of Soil and Water Conservation, Yangtse River' s Scientific Research Institute, Wuhan, Hubei 430010 (China); Liu Puling [Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100 (China); Yao Wenyi [Yellow River Institute of Hydraulic Research, Yellow River Conservancy Commission, Key Laboratory of Yellow River Sediment Research of Ministry of Water Resources, Shunhelu 45, Zhengzhou, Henan 450003 (China)

    2006-03-15

    Spatially averaged soil erosion data provide little information on the process of rill erosion. The dynamically varied data on the temporal and spatial distributions in the rill erosion process are needed to better understand the erosion process and reveal its innate characteristics. The objectives of this study were to examine the feasibility and effectiveness of rare earth element (REE) tracers and the neutron activation analysis (NAA) method on the study of the rill erosion process and to reveal quantitatively the relationships and characteristics of temporal and spatial distributions of sediment yield in rill erosion. Four REEs were used to study the changeable process of rill erosion at 4 slope positions. Four water inflow rates were applied to a 0.3x5 m soil bed at 3 slopes of 10.5%, 15.8% and 21.2% in scouring experiments. All of the runoff was collected in the experiment. Each sample was air-dried and well mixed. Then 20 g of each sample was sieved through 100-mesh and about a 50 mg sample was weighed for analysis of the four elemental compositions by NAA. Results indicate that the REE tracers and NAA method can be used to not only quantitatively determine soil erosion amounts on different slope segments, but also to reveal the changeable process of rill erosion amount. All of the relative errors of the experimental results were less than 25%, which is considered satisfactory on the study of rill erosion process.

  5. Emission tomography: quantitative aspects in metabolic and physiopathologic studies

    International Nuclear Information System (INIS)

    Yerouchalmi-Soussaline, F.

    1984-11-01

    This thesis presents instrumental and data processing studies developped in emission tomography in man, using gamma and positron emitting tracers. High contrast visualisation of volume distribution of tracers in the organs, kinetic studies and measurements of radioactive concentration or of other clinical parameters necessitate a detailed analysis of all physical factors limiting the accuracy of the measure; therefore, development of adapted imaging devices and data processing techniques, together with models describing correctly the phenomena under study are to be carried out. Thus, in single photon (gamma) emission tomography an image reconstruction strategy is elaborated, based on an analytical model for the ill-posed problem including the attenuation effect. In positron emission tomography, the time-of-flight information combined with the reconstruction technique is used in the design of a first prototype imaging device which performance is presented and evaluated in a clinical environment. Moreover, a priori or a posteriori techniques correcting for Compton diffusion events, limited statistics and limited resolutions, are proposed and discussed for the improvement of regional measurement accuracy, in metabolic and physiopathologic studies [fr

  6. Laboratory studies into the use of the scandium-46-EDTA complex as a tracer for groundwater flow

    International Nuclear Information System (INIS)

    Cheng, H.; Nixon, S.C.

    1988-01-01

    Gamma ray emitting metal radionuclides, when complexed with an appropriate complexing agent, provide a wide choice of water tracers particularly for groundwater studies where a radionuclide of appropriate half-life suited to the particular study can be selected. Scandium-46 has easily detectable gamma emission and a suitable half-life (84 days) for medium term studies. It has been widely and successfully used as a tracer in studies of sediment movement but has not yet been introduced as a groundwater tracer. In our experiments the chemical aspects of the preparation of Sc-46-EDTA were studied in some detail and its behaviour in various mineralogical environments was evaluated with reference to the standard tracer, tritiated water. The experimental results have shown that the scandium cation can be easily complexed with EDTA to form soluble SC-EDTA. The complex is very stable in a wide range of pH; the adsorptive properties of Sc-EDTA in the batch studies and the retardation and recovery in the column tests in comparison with tritiated water are quite satisfactory. In general Sc-46-EDTA is a promising tracer for groundwater studies. In the report the appropriate conditions, procedures and some rational and efficient methods for testing the purity of Sc-46-EDTA in the preparation of the tracer solution of Sc-46-EDTA are described. In addition, it has been found that the formation of the metal hydroxide colloids is the major reason for the great loss in groundwater aquifers of most trivalent metal nuclide tracers in the cationic form including scandium-46. (author). 29 refs, 11 figs, 12 tabs

  7. Comparative studies of the nitrogen metabolism of phytoplankton and periphyton in oligotrophic lakes

    International Nuclear Information System (INIS)

    Axler, R.P.; Goldman, C.R.; Reuter, J.E.; Loeb, S.L.; Priscu, J.C.; Carlton, R.G.

    1983-01-01

    This report presents the preliminary data of limnological research at the meso-oligotrophic Castle Lake, CA and at the ultratrophic Lake Tahoe, CA-NEV, USA, during 1980 to 1981. The areas of study were effects of nutrients enrichment and deficiency on primary producers; nitrogen cycling and nitrogen metabolism of benthic and planktonic algae and whole-epilimnion enrichment with ammonium nitrate. Tracer techniques using 14 C- and 15 N-labelled compounds were employed in the study

  8. Earth mechanisms (fluid and solid), life mechanisms and stable isotope tracers. Isotopes and biology, a great project

    International Nuclear Information System (INIS)

    Fromageot, P.

    1997-01-01

    Historical and recent review of the development and use of radioactive isotopes for biological studies in France: study of the intermediate metabolism with 14 C tracers in organic molecules; study and biosynthesis of macromolecules (DNA, RNA and polynucleotides) through the use of marked nucleotides; tracer proteins for use in NMR and protein engineering, use of tritium for the study of hormonal regulation

  9. The study of skeletal calcium metabolism with 41Ca and 45Ca

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Beck, Belinda; Bierman, June M.; Caffee, Marc W.; Heaney, Robert P.; Holloway, Leah; Marcus, Robert; Southon, John R.; Vogel, John S.

    2000-10-01

    The living skeleton can be labeled for life by the administration of radiologically trivial amounts of 41Ca tracer. After initial elimination of tracer from the readily exchangeable calcium pools subsequent skeletal calcium turnover maintains and modulates the urine 41Ca content. Uniquely, bone calcium metabolism may then be studied with tracer in near equilibrium with the body's calcium and resorbing calcium directly measured by accelerator mass spectrometry (AMS) of excreta. Our experiments with 25 41Ca labeled subjects demonstrate excellent diurnal stability and remarkable response to intervention of the urine signal. Thus the tracer method may prove a competitive means of measuring the effects of antiresorptive osteoporosis treatments, for therapy development or even clinical monitoring. Novel studies of long-term skeletal evolution are also possible. We realize that routinely administered short-lived calcium radiotracers contain 41Ca impurities and that thousands of experimental participants have been historically inadvertently 41Ca labeled. The 41Ca urine index might now rapidly further be characterized by contemporary measurements of these one-time subjects, and with their by now thoroughly skeleton-equilibrated tracer they might be ideal participants in other new experiments. We are also investigating 45Ca AMS. It may prove preferable to label the skeleton with this radiotracer already familiar to bioscientists, but new to AMS.

  10. Study of flow characteristics in a secondary clarifier by numerical simulation and radioisotope tracer technique

    International Nuclear Information System (INIS)

    Kim, H.S.; Shin, M.S.; Jang, D.S.; Jung, S.H.; Jin, J.H.

    2005-01-01

    Numerical simulation in a 2-D rectangular coordinate and experimental study have been performed to figure out the flow characteristics and concentration distribution of a large-scale rectangular final clarifier in wastewater treatment facility located in Busan, S. Korea. The purpose of numerical calculation is to verify the experimentally measured data by radioisotope tracer technique and further to understand the important physical feature occurring in a large-scale clarifier, in many cases which is not sufficient by the aid of limited number of experimental data. To this end, a comprehensive computer program is basically made by SIMPLE algorithm by Patankar with the special emphasis on the parametric evaluation of the various phenomenological models. Calculation results are successfully evaluated against experimental data obtained by the method of radioisotope tracer. Detailed comparison is made on the calculated residence time distribution (RTD) curves with measurement inside the clarifier as well as the exhaust. Further the calculation results predict well the well-known characteristics of clarifier flow such as the waterfall phenomenon at the front end of the clarifier, the bottom density current in the settling zone and the upward flow in the withdrawal zone. Thus it is believed that the flow calculation program and the data incorporation technique of radioisotope measurement employed in this study show the high possibility as a complementary tool of experiment in this area

  11. Multi-Tracer Approach for Shelf Water Mixing Studies in Brazilian Regions under Different Climates

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, L. D.; Marins, R. V.; Dias, F. J.S. [Instituto de Ciencias do Mar, Universidate Federal do Ceara, Fortaleza, CE (Brazil); Godoy, M. L.D.P. [Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear, Rio de Janeiro, RJ (Brazil); Godoy, J. M.; Souza, T. A. [Departamento de Quimica, Pontificia Universidade Catolica, Rio de Janeiro, RJ (Brazil); Rezende, C. E. [Centro de Biociencias e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ (Brazil)

    2013-07-15

    Fresh water and sediment supply at estuary and plume regions has dramatically changed due to land use changes, mostly damming, in river basins. The resulting impact, however, may vary significantly depending on climate and hydrology. The seasonal differences in shelf, plume, estuarine and river waters of two watersheds located under contrasting climates in the Brazilian coast are reported using a multi-tracer approach (salinity, barium, silica, uranium, deuterium and {sup 18}O) to characterize the mixing processes. At the Paraiba do Sul River, SE Brazil, in a wet tropical coast, all results showed similarity between dry and wet seasons; at the Jaguaribe river under semi arid climate in NE Brazil, the results showed a moving freshwater plume depending on season, with freshwater at the estuary in the rainy season and shelf water intrusion upstream in the estuary in the dry season. Most tracers used were able to consistently characterize water masses even in the wide range of latitudes studied, confirming their importance as a tool for modelling mixing processes at the continent-ocean boundary. Barium, however, still needs better studies on its seashore chemistry, since in the semi arid site, Ba distribution could not be directly related to conservative mixing behaviour, at least during the rainy season. (author)

  12. Recent progress of {sup 10}Be tracer studies in Chinese loess

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weijian, E-mail: weijian@loess.llqg.ac.cn [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China); Joint Center for Global Change Studies, Beijing 100875 (China); Xie, Xingjun [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Beck, Warren [NSF-Arizona AMS Facility, University of Arizona, Tucson, AZ 85721 (United States); Kong, Xianghui; Xian, Feng; Du, Yajuan; Wu, Zhenkun [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China)

    2015-10-15

    Studies of cosmogenic {sup 10}Be in Chinese loess began about twenty-five years ago and since then a number of research groups worldwide have contributed to a firm understanding of the production, transport, deposition and storage of {sup 10}Be in loess. The essential characteristics that make {sup 10}Be a useful isotopic tracer in loess, include: (1) dominant atmospheric production directly linked to the intensity of the Earth’s magnetic field; (2) climate-dependent deposition; and (3) subsequent immobility, so that as {sup 10}Be accumulates in a loess profile its stratigraphic integrity is preserved. This fact, combined with very high deposition rates in loess on the Chinese Loess Plateau, makes {sup 10}Be an especially valuable continental archive of paleoclimate and paleomagnetism, complementing marine and ice-core records. Here we provide in particular the most recent progress of {sup 10}Be tracer studies in Chinese loess, including the determination of the correct age of the Brunhes–Matuyama polarity reversal at 780 ± 3 ka B.P., in accord with marine and ice records, and quantitative reconstruction of 130-ka paleoprecipitation using {sup 10}Be from Chinese loess profiles.

  13. Natural radon as a limnological tracer for the study of vertical and horizontal eddy diffusion

    International Nuclear Information System (INIS)

    Imboden, D.M.

    1979-01-01

    Radon-222 (half-life 3.8 d) has been used successfully as a geochemical tracer for vertical near bottom mixing in the ocean. The parent nuclide radium-226 (half-life 1600 a) occurs in far greater quantities in sediments than in the water column, thus providing a boundary source for emanation of radon. Vertical mixing in lakes may be of central importance for the evolution of chemical and biological processes. Most lakes pass through a stagnation period during which the euphotic zone continuously loses nutrients by sedimentation of plankton through the thermocline. The return flux of nutrients from the sediments through the hypolimnion and thermocline to the euphotic layer can only be understood and quantified if vertical mixing processes are known. The traditional means by which vertical eddy diffusion is calculated is the temperature method. However, temperature changes near the bottom of deep lakes are often too small to be measured. Among various (natural or man-made) geochemical tracers radon-222 seems to be especially suitable for the study of vertical mixing since its 'memory' of about one week very often allows measured activities to be interpreted in terms of a relatively simple steady-state model

  14. On interpreting studies of tracer transport by deep cumulus convection and its effects on atmospheric chemistry

    Directory of Open Access Journals (Sweden)

    M. G. Lawrence

    2008-10-01

    Full Text Available Global chemistry-transport models (CTMs and chemistry-GCMs (CGCMs generally simulate vertical tracer transport by deep convection separately from the advective transport by the mean winds, even though a component of the mean transport, for instance in the Hadley and Walker cells, occurs in deep convective updrafts. This split treatment of vertical transport has various implications for CTM simulations. In particular, it has led to a misinterpretation of several sensitivity simulations in previous studies in which the parameterized convective transport of one or more tracers is neglected. We describe this issue in terms of simulated fluxes and fractions of these fluxes representing various physical and non-physical processes. We then show that there is a significant overlap between the convective and large-scale mean advective vertical air mass fluxes in the CTM MATCH, and discuss the implications which this has for interpreting previous and future sensitivity simulations, as well as briefly noting other related implications such as numerical diffusion.

  15. Magnitude of the Suess Effect in North Atlantic - a Study of Foraminifera and Transient Tracer Simulations

    Science.gov (United States)

    Zhou, Y.; Oppo, D.; Gebbie, G.; Thornalley, D. J.

    2016-02-01

    The Suess Effect is the decrease of δ 13C in the atmosphere due to the burning of fossil fuels. The recent decrease in δ 13C in the deep sea due to uptake of carbon has been measured in samples taken on hydrographic surveys, although these surveys only provide snapshots of deep sea δ 13C. The long-term decrease in δ 13C has been estimated using modern hydrographic properties, but there are no direct measurements. Here we present records of δ 13C from benthic and planktonic foraminifera, collected south of Iceland in the North Atlantic Ocean. The cores have high accumulation rates and, based on radiocarbon, modern core tops. We find a monotonic decreasing trend since 1850 that is significant in two out of the three benthic records we have generated. A tracer simulation, with Transit Time Distribution and Equilibrium Time Distribution generated from previous tracer modeling studies, predicts a trend that is similar to our observations at the core sites. The presence of the Suess Effect in some of the cores is consistent with previous estimates on the uptake of anthropogenic CO{}2 in the newly formed North Atlantic Deep Water.

  16. A novel double-tracer technique to characterize absorption, distribution, metabolism and excretion (ADME) of [14C]tofogliflozin after oral administration and concomitant intravenous microdose administration of [13C]tofogliflozin in humans.

    Science.gov (United States)

    Schwab, Dietmar; Portron, Agnes; Backholer, Zoe; Lausecker, Berthold; Kawashima, Kosuke

    2013-06-01

    observed CL(R) of 25.7 ± 5.0 ml/min was higher than the product of the estimated glomerular filtration rate (eGFR) and fraction unbound in plasma (f(u)) (eGFR × f(u) 15 ml/min), indicating the presence of net active tubular secretion in the renal elimination of tofogliflozin. However, CLR contributed only 15.5 % to the CL of tofogliflozin, suggesting that reductions in CLR by renal impairment won't significantly affect systemic exposure to tofogliflozin. Tofogliflozin and its metabolite M1 were the only major circulating entities accounting for 46 ± 8.6 and 50 ± 8.2 %, respectively, of total circulating drug-related material, while the metabolite M5 was a minor circulating metabolite accounting for 3.0 ± 0.3 % of total circulating drug-related material. Both the M1 and M5 metabolites were excreted into urine and the major metabolite M1 did not exhibit active tubular secretion. These results demonstrate the utility of the double-tracer approach to provide essential pharmacokinetic data and excretion data for drug-related material in one study at the same dosing occasion. The data obtained allowed the characterization of absorption, distribution, metabolism and excretion of tofogliflozin. Tofogliflozin exhibited highly favorable pharmacokinetic properties as demonstrated by its high F, low CL and a low V(ss. The presence of only one major circulating metabolite of tofogliflozin was unambiguously demonstrated. As a drug targeting the kidney, luminal exposure of the kidney is achieved by renal filtration and active tubular secretion.

  17. Quantifying the Contribution of Grape Hexoses to Wine Volatiles by High-Precision [U13C]-Glucose Tracer Studies

    Science.gov (United States)

    Nisbet, Mark A.; Tobias, Herbert J.; Brenna, J. Thomas; Sacks, Gavin L.; Mansfield, Anna Katharine

    2016-01-01

    Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision 13C/12C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01–1 APE) of uniformly labeled [U-13C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of 13C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor–product relationships. PMID:24960193

  18. Quantifying the contribution of grape hexoses to wine volatiles by high-precision [U¹³C]-glucose tracer studies.

    Science.gov (United States)

    Nisbet, Mark A; Tobias, Herbert J; Brenna, J Thomas; Sacks, Gavin L; Mansfield, Anna Katharine

    2014-07-16

    Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision (13)C/(12)C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01-1 APE) of uniformly labeled [U-(13)C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of (13)C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor-product relationships.

  19. Search for a non-metabolizable PET tracer for heart neuronal imaging

    International Nuclear Information System (INIS)

    Wieland, D.M.; Rosenspire, K.C.; Van Dort, M.E.; Haka, M.S.; Jung, Y.W.; Gildersleeve, D.L.

    1990-01-01

    The tracer (1R,2S)-(-)-[ 11 C]-meta-hydroxyephedrine (MHED) is used successfully at the authors' institution to study neuronal heart diseases and neuroendocrine tumors. However, MHED is rapidly metabolized in humans, most likely to alpha-methylepinephrine and its 3-O-methyl ether by the initial action of liver microsomal hydroxylase. This presentation will describe efforts to develop a [ 11 C]-labelled neuronal tracer that is completely resistant to metabolism on the PET-imaging time scale

  20. Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

    International Nuclear Information System (INIS)

    Scofield, P.A.

    1986-01-01

    The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

  1. The metabolism of the human brain studied with positron emission tomography

    International Nuclear Information System (INIS)

    Greitz, T.; Ingvar, D.H.; Widen, L.

    1985-01-01

    This volume presents coverage of the use of positron emission tomography (PET) to study the human brain. The contributors assess new developments in high-resolution positron emission tomography, cyclotrons, radiochemistry, and tracer kinetic models, and explore the use of PET in brain energy metabolism, blood flow, and protein synthesis measurements, receptor analysis, and pH determinations, In addition, they discuss the relevance and applications of positron emission tomography from the perspectives of physiology, neurology, and psychiatry

  2. Tracer sorption and macroscopic transport in clay nano-pores: a lattice-Boltzmann study

    International Nuclear Information System (INIS)

    Levesque, Maximilien; Rotenberg, Benjamin; Duvail, Magali; Benichou, Olivier; Voituriez, Raphael; Pagonabarraga, Ignacio; Frenkel, Daan

    2012-01-01

    Document available in extended abstract form only. The Agence Nationale pour la gestion des Dechets Radioactifs (ANDRA) has been entrusted to find a safe solution for disposing of existing and future nuclear wastes. A prototype site has been considered for the waste disposal in a deep underground sedimentary geological formation. It is composed of clay minerals chosen, among other reasons, for their remarkable ability to limit radionuclide transport. Clay minerals are complex charged porous media characterized by heterogeneities at several length scales. They naturally occur as an assembly of few nano-meter-sized particles connected to form 10 to 100 nm interparticle pores containing water and ions. This intrinsically multi-scale structure, that gives the material its remarkable properties, makes the description of sorption and transport phenomena of transported ions particularly challenging. Experimental studies of water and ion transport through clays mostly consist in evaluating macroscopic effective transport coefficients like permeability or conductivity. They showed that the main transport mechanism is an effective diffusion that not only depends on particle charge but also on its chemical nature, or specificity. The goal of assessing the performance of clays as confinement barriers, particularly in the context of the geological disposal of nuclear waste, requires not only quantitative prediction of the retention and transport of species but also an understanding of the microscopic mechanisms underlying them. A successful approach has been to use numerical simulations via the Lattice-Boltzmann method (LB). It consists in making evolve populations describing the fluid at a level which is consistent with time and length-scales involved in transport properties, while still including a microscopic description of the phenomena. The transport of charged ions at the pore scale has recently been included in LB. In this method, the evolution of a tracer population is

  3. Study of sensitivity and application of some tracers of use in hydrologic works

    International Nuclear Information System (INIS)

    Aguilar, M.C.

    1980-05-01

    Inside the Industrial Applications Management, particularly in the Hydrology department, in the ININ outlined diverse problems are had in the study of underground waters and surface waters that either in a particular way, or in inter institutional collaboration (SARH, CFE, UNAM) it seen the necessity to solve this problem in the interconnection aspects in aquifer, expenses and contamination. One of the medullary parts that are had in this study is the applied evaluation of the tracer one that it presents two general aspects: a) determination method and b) Applicability depending on the land type that one has in the current to be applied. This study seeks according to: the sensibility reached with each one, and the evaluation of some other parameters like used time, cost and mainly realization feasibility at field level, to present some alternative for the use of them. (Author)

  4. Influence of nutrition on protein synthesis and 15N tracer data in man

    International Nuclear Information System (INIS)

    Faust, H.

    1984-01-01

    Quantitative studies and measurements of parameters of the protein metabolism in vivo require the isotope methodology. Different 15 N tracer methods with special modifications are available which can be used depending on clinical problems. The oral single pulse application of [ 15 N]glycine is equal to other isotope tracer techniques provided that the basic assumptions of the application are fullfilled. The protein metabolism is clearly influenced by the nutritional status whereby the protein synthesis is more sensitive than the breakdown to altered dietary intakes of protein and energy. The importance of standardized experimental conditions is emphasized for studies with 15 N and the interpretation of tracer data. (author)

  5. Studies of the calcium metabolism of subjects with renal dysfunction

    International Nuclear Information System (INIS)

    Kotler, L.H.

    1983-01-01

    In order to perform a detailed study of calcium metabolism, it is necessary to differentiate between intestinal absorption and its subsequent behaviour in terms of either uptake onto the bone or excretion. The measurement of calcium absorption involved two separate intakes of the tracer 47 Ca. Each subject ingested a known activity. Measurements on blood samples were made after 5 hours and a smoothed curve describing the appearance of the activity in the plasma was determined. About 4 weeks after oral ingestion a known activity was injected into the subject and the procedure repeated. A curve describing the differential transfer of calcium from the intestine to the blood stream was derived by performing a deconvolution procedure on the two curves

  6. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  7. 15N tracer techniques in pediatric research

    International Nuclear Information System (INIS)

    Heine, W.; Richter, I.; Plath, C.; Wutzke, K.; Stolpe, H.J.; Tiess, M.; Toewe, J.

    1983-01-01

    The main topics of the review comprise mathematical fundamentals of the determination of N metabolism parameters using the 3-pool method, the value of different 15 N tracer substances for the determination of whole-body protein parameters, the utilization of parenterally applied D-amino acids, studies on the influence of different diets on the N metabolism of premature infants with the 15 N tracer technique, the application of the 15 N-glycine-STH-test for the evaluation of the therapeutic effect of STH in children suffering from hypothalamico-hypophyseal dwarfism, in vivo studies on urea utilization by the infant intestinal flora under various dietary regimens as well as in vitro investigations on the utilization of 15 N-labelled urea and NH 4 Cl, resp., by the intestinal flora

  8. A Preliminary Study on the Measurement of Sediment Concentration in Hill-Slope Runoff with an Electrolyte Tracer

    Directory of Open Access Journals (Sweden)

    Xiaonan Shi Fan Zhang

    2012-01-01

    Full Text Available Sediment concentration in hill-slope runoff is an important index for soil erosion. Developing a reliable and portable measuring system of sediment concentration is a core issue for soil and water conservation study, especially for the Tibetan Plateau under unfavorable climate and terrain conditions for field investigation. Challenges include uneven distribution of sediment across a runoff section as well as difficulty in detecting a wide range of particle sizes. An electrolyte tracer, with the advantage of uniform distribution and its widely used electric-conductivity sensor, can avoid the problems of direct measurement of sediment. A new measurement method of sediment concentration in runoff with an electrolyte tracer is proposed based on a premise that sediment concentration is closely correlated with hydrodynamic dispersion coefficient of solute in runoff. In this study, an experiment system of hill-slope runoff with an electrolyte tracer and sediments is first designed. Second, two model parameters in the advective-dispersive equation of solute transport, flow velocity and diffusion coefficient, are inversely estimated by calibrating the observed concentrations of an electrolyte tracer. And third, the relationship between sediment concentrations and hydrodynamic dispersion coefficients are defined through specified regression. As a result, a measurement system of sediment concentration in hill-slope runoff with an electrolyte tracer is primarily established by integrating the relationship of variables, experiment system, and model theory.

  9. Hydrodynamics of a commercial scale CFB boiler-study with radioactive tracer particles

    DEFF Research Database (Denmark)

    Lin, Weigang; Hansen, Peter F.B.; Dam-Johansen, Kim

    1999-01-01

    This paper presents the experimental results with radioactive tracer particles in an 80 MWth circulating fluidized-bed boiler. Batches of gamma-ray emitting tracer particles were injected into the standpipe. The response curves of the impulse injection were measured by a set of successive scintil...

  10. Isotopic and geochemical tracers for fingerprinting process-affected waters in the oil sands industry: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.J.; Birks, S.J.; Moncur, M.; Yi, Y.; Tattrie, K.; Jasechko, S.; Richardson, K.; Eby, P. [Alberta Innovates - Technology Futures (Canada)

    2011-04-15

    During 2009 and 2010, Alberta Innovates - Technology Futures carried out a pilot study for Alberta Environment to examine the possibility of labeling process affected water from oil sands operations with isotropic and geochemical tracers. For the study, 3 oil sands operators furnished logistical support and personnel, 39 samples were gathered and several isotope tracers were measured. In addition, geotechnical analyses were performed and the presence of organic compounds in the samples was scanned using Fourier transform ion cyclotron resonance mass spectrometry. Results showed that the selected tracers were able to label water sources in some locations, however they cannot be used as a universal method and a case by case approach needs to be adopted. This study pointed out that Fourier transform ion cyclotron resonance mass spectrometry is the best way to construct a dataset for use in identification of process affected waters.

  11. Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131

    International Nuclear Information System (INIS)

    Wibagiyo

    2004-01-01

    Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131, carried out in 2002, the similar studies was also conducted in 2000 from subsurface river in Jurang Jero sinkhole, where the radioactivity appeared at Bribin cave 4 hours and 8 hours at Ngreneng cave. There is a question whether a subsurface river is flowing from Jurang Jero sinkhole to Bribin cave and then to Ngreneng cave, or from Jurang Jero sinkhole there is junction to Bribin and to Ngreneng. in 2002 a Germany team founded junction on up stream of river in Bribin cave, from the junction was carried out tracing which monitoring in Ngreneng cave. Where the result a junction connecting with Ngreneng cave, but the main stream in Bribin not connecting with Ngreneng. (author)

  12. Studies of deep water formation and circulation in the Weddell Sea using natural and anthropogenic tracers

    International Nuclear Information System (INIS)

    Schlosser, Peter; Bayer, Reinhold

    1991-01-01

    The application of natural and anthropogenic trace substances in oceanographic studies of the Weddell Sea is reviewed. The potential of some steady-state and transient tracers (tritium, CFC-11 and CFC-12, 18 O, and helium isotopes) for studies of deep water formation and circulation is discussed on the basis of data sets collected mainly on cruises of R/V 'Polastern' to the Weddell Sea during the 1980s. CFC/ tritium ratio dating of young water masses is applied to estimate mean age and transit times of water involved in Weddell Sea Bottom Water formation. The history of the CFC-11/tritium ratio through time is derived for Weddell Sea shelf waters. (author). 36 refs.; 18 figs

  13. Use of 65 Zn as radioactive tracer in the bioaccumulation study of zinc by aquatic organisms

    International Nuclear Information System (INIS)

    Malagrino, W.

    1992-01-01

    The present work has as main objective to emphasize the importance of using radioactive tracers as well as to establish a methodology for the utilization of 65 Zn in the bioaccumulation study of zinc by Poecilia reticulata. The exposure time varied from 5 days (short term experiments) to 30 days (long term experiments). The bioaccumulation of zinc from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 65 Zn which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behaviour of the stable zinc since the radionuclide used is an isotope of the same element and therefore presents the same chemical properties. (author)

  14. Using isoelectric focussing and neutron activation analysis to study protein-bound tracer elements

    International Nuclear Information System (INIS)

    Schmelzer, W.

    1976-01-01

    A method to determine protein-bound tracer elements was determined by combining a protein separation method with neutron activation analysis. Gel filtration, disk electrophoresis, and isoelectric focussing were studied with regard to their suitability as separation methods. Using isoelectric focussing, human serum protein could be separated with good resolution on a preparative scale. The Se, Cr, Ag, Sc, Fe, Zn, Co, Br, Na, Rb, and Cs contents of the various protein fractions were determined by instrumental neutron activation analysis and by gamma-spectroscopic identification of their long-lived nuclides. Particular attention was paid to the main source of error with this method, i.e. contamination of the proteins in the course of the separation process. Information on the binding of the elements to protein was obtained by comparing the contents in the serum and in the protein separated by gel chromatography. For example, 75% of the Se and 30% of the Cs are bound to protein. Contamination of the protein fractions was studied by means of tracer elements with the element Se, errors due to contamination could be ruled out. The method was modified for the special imvestigation of Se-protein complexes in the serum. The Se content was determined by activation analysis via the short-lived radionuclide sup(77m)Se, this considerably reducing the duration of analysis. With regard to focussing, discrimination was improved in the pH region in which specific Se complexes were found. The activity distribution in fractionated serum protein labelled in vitro with 75 Se in the presence of erythrocytes showed that specific labelling is possible in this way. It is thus possible to study the distribution of Se carrier proteins with the aid of a radiotracer technique. (orig./RB) [de

  15. Study of the migration of metallic micropollutants in the soils by means of radioactive tracers

    International Nuclear Information System (INIS)

    Jacquemet, P.

    1995-01-01

    The aim of this work was to study the migration of metallic micropollutants using radioactive tracers. Three experimental techniques were employed to show the interaction phenomena linked to these migrations. First, a simple batch characterization allows the qualitative and quantitative evaluation of the sorption-desorption of the micropollutants on the soils. Next, an elution technique applied to soil columns was introduced to study the behavior of the pollutants in hydrodynamic conditions. Finally, a series of lysimetric pots were prepared to extend the experiment to systems which mimic a natural environment. The tests were conducted in a hot laboratory with five agricultural soils and seven pollutants ( 57 Co, 134 Cs, 123m Te, 109 Cd, 144 Ce, 85 Sr and 110m Ag). The batch measurements (kinetics, K d sorption ratio at equilibrium and isothermal measurements according to the Langmuir or Freundlich models) allowed for a better understanding of the sorption-desorption mechanisms of the micropollutants. Their migration on continuously percolated columns (breakthrough curves and determination of the radioactive profiles in the soils) was evaluated and expounded together with the results obtained from the batch characterization. The profiles of the radioactive tracers in the soils of the lysimeters (with or without vegetation) were also determined. All these observations were used to characterize the migration properties of the micropollutants in the investigated soils. A simple simulation model of the migration of interactive solutes in porous media based on dispersion and convection was also applied to the experimental data. The calculated profiles showed fairly good agreement with the experimental ones, especially in the case of unplanted systems. Several parametric adjustments were, however, necessary. It was shown, finally, that simulations, as perfect as they could be, can seldom replace the experimental studies of the behaviour of micropollutants in the

  16. Experimental study of ventilation efficiency with a gaseous tracer (He and SF6)

    International Nuclear Information System (INIS)

    Roussel, Claude

    1982-01-01

    When it is desired to test the efficiency of a ventilation system in a nuclear installation in normal working conditions or in an accidental situation, it is possible to avoid having recourse to the direct use of contaminating, toxic or explosive substances, by carrying out a simulation by atmospheric tracing. The study of the scattering shows that the dispersion of substances in the atmosphere that is met in a nuclear plant is practically independent of the nature of the substance emitted, whether it be an aerosol, a gas of ''heavy'' molecular mass or low molecular mass. To show the scattering phenomena a tracer can be employed that is not dangerous in use, is easy to use and for which there is a simple and transportable instrumentation [fr

  17. Application of isotope tracer technique on the study of the filling and release behavior of carbon nanotubes

    International Nuclear Information System (INIS)

    Wu Shengwei; Guo Jinxue; Li Yan; Li Yulan; Li Wenxin; Liu Shiyuan

    2004-01-01

    The behaviors of washing and release of 110 Ag m -AgNO 3 from carbon nanotubes (CNTs), following soak of opened CNTs in 110 Ag m -AgNO 3 solutions are investigated with the isotope tracer technique. The filled CNTs samples are characterized by HREM, SEM, XRD and EDS. The amount of filled materials is also estimated by the isotope tracer technique. It shows that there are silver materials filled in the CNTs and would not release from the cavities. The results indicate that radioactive tracer is an effective and powerful technique to be applied into study of filling and release behaviors of CNTs as well as estimating the amount of filled materials. (authors)

  18. Tritium as tracer of groundwater pollution extension: case study of Andralanitra landfill site, Antananarivo-Madagascar

    Science.gov (United States)

    Ramaroson, Voahirana; Rakotomalala, Christian Ulrich; Rajaobelison, Joel; Fareze, Lahimamy Paul; Razafitsalama, Falintsoa A.; Rasolofonirina, Mamiseheno

    2018-05-01

    This study aims to understand the extension of groundwater pollution downstream of a landfill, Andralanitra-Antananarivo-Madagascar. Twenty-one samples, composed of dug well waters, spring waters, river, and lake, were measured in stable isotopes ( δ 2H, δ 18O) and tritium. Results showed that only two dug well waters, collected at the immediate vicinity of the landfill, have high tritium activities (22.82 TU and 10.43 TU), probably of artificial origin. Both upstream and further downstream of the landfill, tritium activities represent natural source, with values varying from 0.17 TU to 1.46 TU upstream and from 0.88 TU to 1.88 TU further downstream. Stable isotope data suggest that recharge occurs through infiltration of slightly evaporated rainfall. Using the radioactive decay equation, the calculated tracer ages related to two recent ground water samples collected down gradient of the landfill lay between [8-15] years and [4-7] years, taking into account the uncertainty of tritium measurements. For the calculation, a value of 2.36 TU was taken as A o. The latter was estimated based on similarity between stable isotope compositions of nearby spring and dug well waters as well as tritium activities of the local precipitation. Calculation of the tritium activities from the contaminated water point having 22.82 TU to further downstream using the calculated tracer ages showed values of one order of magnitude higher than the measured values. The absence of hydrological connection from the contaminated water point to further downstream the landfill would explain the lower tritium activities measured. Groundwater pollution seems to be limited to the closest proximity of the landfill.

  19. Predictive value of tracer studies for 131I treatment in hyperthyroid cats

    International Nuclear Information System (INIS)

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

    1988-01-01

    In 76 cats with hyperthyroidism, peak thyroidal radioiodine ( 131 I) uptakes and effective half-lives were determined after administration of tracer and therapeutic activities of 131 I. In 6 additional hyperthyroid cats, only peak thyroidal uptakes after administration of tracer and therapeutic activities of 131 I were determined. Good correlation was found between peak thyroidal uptakes of tracer and therapeutic 131 I; however, only fair correlation was observed between effective half-lives. In 79% of the cats, the effective half-life for therapeutic 131 I was longer than that for tracer 131 I. After administration of therapeutic activity of 131 I, monoexponential and biphasic decay curves were observed in 51 and 16 cats, respectively. Using therapeutic kinetic data, radiation doses to the thyroid gland were calculated retrospectively on the basis of 2 methods for determining the activity of 131 I administered: (1) actual administration of tracer-compensated activity and (2) hypothetic administration of uniform activity (3 mCi). Because of the good predictive ability of tracer kinetic data for the therapeutic kinetic data, the tracer-compensated radiation doses came significantly (P = 0.008) closer to the therapeutic goal than did the uniform-activity doses. In addition, the use of tracer kinetic information reduced the extent of the tendency for consistently high uniform-activity doses. A manual method for acquiring tracer kinetic data was developed and was an acceptable alternative to computerized techniques. Adoption of this method gives individuals and institutions with limited finances the opportunity to characterize the iodine kinetics in cats before proceeding with administration of therapeutic activities of 131 I

  20. Study of movement of fly ash by radioactive tracer studies at Ennore Thermal Power Station (Tamil Nadu)

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, L K; Dange, A P

    1982-01-01

    This paper presents a study of the movement of fly ash from the Thermal Power Station at Ennore dumped in the ocean. The purpose of the study was to ensure that the ash dumped in the sea does not find its way to intake of the power station through the mouth of the river situated at a distance of 2 kms north. In such situations the use of radioactive tracer studies is found to be very effective and these studies indicated the necessity of dumping the fly ash beyond 6 m depth in the sea.

  1. Study of movement of fly ash by radioactive tracer studies at Ennore Thermal Power Station (Tamil Nadu)

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, L K; Dange, A P [Central Water and Power Research Station, Pune (India)

    1982-01-01

    This paper presents a study of the movement of fly ash from the Thermal Power Station at Ennore dumped in the ocean. The purpose of the study was to ensure that the ash dumped in the sea does not find its way to intake of the power station through the mouth of the river situated at a distance of 2 kms north. In such situations the use of radioactive tracer studies is found to be very effective and these studies indicated the necessity of dumping the fly ash beyond 6m depth in the sea.

  2. Towards tracer dose reduction in PET studies: Simulation of dose reduction by retrospective randomized undersampling of list-mode data.

    Science.gov (United States)

    Gatidis, Sergios; Würslin, Christian; Seith, Ferdinand; Schäfer, Jürgen F; la Fougère, Christian; Nikolaou, Konstantin; Schwenzer, Nina F; Schmidt, Holger

    2016-01-01

    Optimization of tracer dose regimes in positron emission tomography (PET) imaging is a trade-off between diagnostic image quality and radiation exposure. The challenge lies in defining minimal tracer doses that still result in sufficient diagnostic image quality. In order to find such minimal doses, it would be useful to simulate tracer dose reduction as this would enable to study the effects of tracer dose reduction on image quality in single patients without repeated injections of different amounts of tracer. The aim of our study was to introduce and validate a method for simulation of low-dose PET images enabling direct comparison of different tracer doses in single patients and under constant influencing factors. (18)F-fluoride PET data were acquired on a combined PET/magnetic resonance imaging (MRI) scanner. PET data were stored together with the temporal information of the occurrence of single events (list-mode format). A predefined proportion of PET events were then randomly deleted resulting in undersampled PET data. These data sets were subsequently reconstructed resulting in simulated low-dose PET images (retrospective undersampling of list-mode data). This approach was validated in phantom experiments by visual inspection and by comparison of PET quality metrics contrast recovery coefficient (CRC), background-variability (BV) and signal-to-noise ratio (SNR) of measured and simulated PET images for different activity concentrations. In addition, reduced-dose PET images of a clinical (18)F-FDG PET dataset were simulated using the proposed approach. (18)F-PET image quality degraded with decreasing activity concentrations with comparable visual image characteristics in measured and in corresponding simulated PET images. This result was confirmed by quantification of image quality metrics. CRC, SNR and BV showed concordant behavior with decreasing activity concentrations for measured and for corresponding simulated PET images. Simulation of dose

  3. Metabolic flux analysis of the phenylpropanoid pathway in wound-healing potato tuber tissue using stable isotope-labeled tracer and LC-MS spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Fumio; Morino, Keiko; Miyashita, Masahiro; Miyagawa, Hisashi [Kyoto Univ. (Japan). Department of Agriculture

    2003-05-01

    The metabolic flux of two phenylpropanoid metabolites, N-p-coumaroyloctopamine (p-CO) and chlorogenic acid (CGA), in the wound-healing potato tuber tissue was quantitatively analyzed by a newly developed method based upon the tracer experiment using stable isotope-labeled compounds and LC-MS. Tuber disks were treated with aqueous solution of L-phenyl-d{sub 5}-alanine, and the change in the ratio of stable isotope-labeled compound to non-labeled (isotope abundance) was monitored for p-CO and CGA in the tissue extract by LC-MS. The time-dependent change in the isotope abundance of each metabolite was fitted to an equation that was derived from the formation and conversion kinetics of each compound. Good correlations were obtained between the observed and calculated isotope abundances for both p-CO and CGA. The rates of p-CO formation and conversion (i.e. fluxes) were 1.15 and 0.96 nmol (g FW){sup -1}h{sup -1}, respectively, and for CGA, the rates 4.63 and 0.42 nmol (g FW){sup -1}h{sup -1}, respectively. This analysis enabled a direct comparison of the biosynthetic activity between these two compounds. (author)

  4. Case study: evaluation of the performance of water treatment units by the use of tracer techniques

    International Nuclear Information System (INIS)

    Sebastian, C.; Maghella, G.; Mamani, E.

    2000-12-01

    Very often, water treatment systems do not reach the expected performance due to disturbances of hydraulic order, which cause malfunctioning in the flow through such systems. Tracer techniques have proved to be very useful to obtain information on the system or a part of it, by means of observation of the released tracer or observation of the released tracer during its progress into the system or at the output of the same. This paper is a report of the behavior of a set of both sand settlement unit and hydraulic flocculators in a potable water plant, through the analysis of radiotracers response curves or residence time distribution curves. The tracers released into the system consists in an aqueous solution of Iodine-131 with very low activity, in order to get a dynamic behave similar to the one of the fluid under investigation

  5. Oxygen tracer studies of ferroelectric fatigue in Pb(Zr,Ti)O3 thin films

    International Nuclear Information System (INIS)

    Schloss, Lawrence F.; McIntyre, Paul C.; Hendrix, Bryan C.; Bilodeau, Steven M.; Roeder, Jeffrey F.; Gilbert, Stephen R.

    2002-01-01

    Long-range oxygen motion has been observed in Pt/Pb(Zr,Ti)O 3 /Ir thin-film structures after electrical fatigue cycling at room temperature. Through an exchange anneal, isotopic 18 O was incorporated as a tracer into bare Pb(Zr,Ti)O 3 (PZT) films, allowing secondary ion mass spectrometry measurements of the tracer profile evolution as a function of the number of polarization reversals. Observation of 18 O tracer redistribution during voltage cycling, which is presumably mediated by oxygen vacancy motion, was found to be strongly dependent upon the thermal history of the film. However, there was no strong correlation between the extent of 18 O tracer redistribution and the extent of polarization suppression induced by voltage cycling. Our results suggest that oxygen vacancy motion plays, at most, a secondary role in ferroelectric fatigue of PZT thin films

  6. The field tracer test study of atmospheric dispersion in Fujian Huian Nuclear Power Plant site

    International Nuclear Information System (INIS)

    Hu Erbang; Xin Cuntian; Yan Jiangyu; Ren Zhiqiang; Xuan Yiren; Jia Peirong

    2003-01-01

    The SF 6 tracer tests and its main results completed in site of Fujian Huian Nuclear Power Plant during summer, 2002, are described. A total of 15 times of SF 6 tracer tests were done in the July, in which the time of atmospheric stability B, C, D, E is respectively 3, 2, 9, 1 based on ΔT-U method and the time of B, D, E is respectively 1, 11, 3 based on ΔT method. About 50 samples were collected in each SF 6 tracer tests, the maximum of sample distance from the tower in which the SF 6 tracer was released is about 15 km. The values of p y , p z , q y , q z in the formula of diffusion parameters is determined. Finally the above diffusion parameters are compared with P-G curve, Briggs diffusion parameters and those obtained from turbulence observation and wind tunnel simulation test done in the past time. (authors)

  7. An evaluation of an improved method for computing histograms in dynamic tracer studies using positron-emission tomography

    International Nuclear Information System (INIS)

    Ollinger, J.M.; Snyder, D.L.

    1986-01-01

    A method for computing approximate minimum-mean-square-error estimates of histograms from list-mode data for use in dynamic tracer studies is evaluated. Parameters estimated from these histograms are significantly more accurate than those estimated from histograms computed by a commonly used method

  8. Using radioactive tracer technique in municipal hygiene

    International Nuclear Information System (INIS)

    Yurasova, O.I.

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology

  9. Using radioactive tracer technique in municipal hygiene

    Energy Technology Data Exchange (ETDEWEB)

    Yurasova, O I [Institut Obshchej i Kommunal' noj Gigieny, Moscow (USSR)

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology.

  10. In vivo trace element speciation study by using enriched stable isotopic tracer technique

    International Nuclear Information System (INIS)

    Feng Weiyue; Chai Zhifang; Shi Junwen; Ding Wenjun

    2005-01-01

    In contrast to the radioactive tracer method, the enriched stable isotopic technique used in life sciences will not cause radiation damage to cells and its operation will be no radioactive risk, In our laboratory, the enriched stable isotopes Cr-50, Hg-196 and Hg-198 combined with biochemical separation, neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP-IVIS) have been used to investigate the element speciation in vivo. Chromium (Cr) is proposed to act as a potentiator of insulin action in animals and human beings. Its deficiency induces the symptoms resembling diabetes and its supplement can alleviate these symptoms. However, as the concentration of Cr in vivo is usually at ultratrace level(- ng/g), its speciation study is usually difficult, since it is almost impossible to avoid the exogenous Cr contamination caused by separation and determination processes. Therefore, in this study, 50 Cr 2 O 3 with 94.2% 50 Cr was used as a tracer combined with gel chromatography to study the Cr speciation in serum, liver, urine and other tissues of healthy and diabetic rats. The Cr concentrations can be determined via 50 Cr(n, γ) 51 Cr by NAA, which is ideally suited for the ultratrace element analyses due to its high precision, accuracy and sensitivity. Such research have found that the most quantity of chromium in vivo is mainly combined with high molecular weight proteins, which is later identified as transferrin and low molecular weight protein is mainly excreted from urine. Mercury is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the global environment. Mercury compounds in the environment are often difficult to degrade. However, the mechanism on mercury toxicity to developing children following long term and low dose of mercury exposure is still not clear. Therefore, high sensitive method in vivo needs to be developed to study such low level mercury toxicity to fetus In this

  11. [1-11C]octanoate as a PET tracer for studying ischemic stroke. Evaluation in a canine model of thromboembolic stroke with positron emission tomography

    International Nuclear Information System (INIS)

    Kuge, Yuji; Kawashima, Hidefumi; Minematsu, Kazuo

    2000-01-01

    Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after β-oxidation. Consequently, [1- 11 C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1- 11 C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1- 11 C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2, 3, 5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1- 11 C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1- 11 C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1- 11 C]octanoate relative to CBF takes place in these regions. In conclusion, [1- 11 C]octanoate accumulated in ischemic but vital regions, indicating that [1- 11 C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. (author)

  12. Measurement of open streams by using tracers

    International Nuclear Information System (INIS)

    Ramos, German F.; Tarquino, W.; Curcuy, H.; Orozco, C.

    1999-01-01

    This paper presents an intercomparison study to be carried out between flux measurements by using tracers and moulinet. This intercomparison is scheduled to be performed at the measurement station belonging to the National Service of Meteorology and Hydrology (SENAMHI). Two techniques of tracer dilution are outstanded: total evaluation with tracer punctual injection and punctual evaluation with tracer continuous injection. Total evaluation with tracer punctual injection has been used since this technique is considered to be more suitable for hydrology purposes

  13. A double-tracer technique to characterize absorption, distribution, metabolism and excretion (ADME) of [14C]-basimglurant and absolute bioavailability after oral administration and concomitant intravenous microdose administration of [13C6]-labeled basimglurant in humans.

    Science.gov (United States)

    Guerini, Elena; Schadt, Simone; Greig, Gerard; Haas, Ruth; Husser, Christophe; Zell, Manfred; Funk, Christoph; Hartung, Thomas; Gloge, Andreas; Mallalieu, Navita L

    2017-02-01

    1. The emerging technique of employing intravenous microdose administration of an isotope tracer concomitantly with an [ 14 C]-labeled oral dose was used to characterize the disposition and absolute bioavailability of a novel metabotropic glutamate 5 (mGlu5) receptor antagonist under clinical development for major depressive disorder (MDD). 2. Six healthy volunteers received a single 1 mg [ 12 C/ 14 C]-basimglurant (2.22 MBq) oral dose and a concomitant i.v. tracer dose of 100 μg of [ 13 C 6 ]-basimglurant. Concentrations of [ 12 C]-basimglurant and the stable isotope [ 13 C 6 ]-basimglurant were determined in plasma by a specific LC/MS-MS method. Total [ 14 C] radioactivity was determined in whole blood, plasma, urine and feces by liquid scintillation counting. Metabolic profiling was conducted in plasma, urine, blood cell pellet and feces samples. 3. The mean absolute bioavailability after oral administration (F) of basimglurant was ∼67% (range 45.7-77.7%). The major route of [ 14 C]-radioactivity excretion, primarily in form of metabolites, was in urine (mean recovery 73.4%), with the remainder excreted in feces (mean recovery 26.5%). The median t max for [ 12 C]-basimglurant after the oral administration was 0.71 h (range 0.58-1.00) and the mean terminal half-life was 77.2 ± 38.5 h. Terminal half-life for the [ 14 C]-basimglurant was 178 h indicating presence of metabolites with a longer terminal half-life. Five metabolites were identified with M1-Glucuronide as major and the others in trace amounts. There was minimal binding of drug to RBCs. IV pharmacokinetics was characterized with a mean ± SD CL of 11.8 ± 7.4 mL/h and a Vss of 677 ± 229 L. 4. The double-tracer technique used in this study allowed to simultaneously characterize the absolute bioavailability and disposition characteristics of the new oral molecular entity in a single study.

  14. Chemical Tracer Methods: Chapter 7

    Science.gov (United States)

    Healy, Richard W.

    2017-01-01

    Tracers have a wide variety of uses in hydrologic studies: providing quantitative or qualitative estimates of recharge, identifying sources of recharge, providing information on velocities and travel times of water movement, assessing the importance of preferential flow paths, providing information on hydrodynamic dispersion, and providing data for calibration of water flow and solute-transport models (Walker, 1998; Cook and Herczeg, 2000; Scanlon et al., 2002b). Tracers generally are ions, isotopes, or gases that move with water and that can be detected in the atmosphere, in surface waters, and in the subsurface. Heat also is transported by water; therefore, temperatures can be used to trace water movement. This chapter focuses on the use of chemical and isotopic tracers in the subsurface to estimate recharge. Tracer use in surface-water studies to determine groundwater discharge to streams is addressed in Chapter 4; the use of temperature as a tracer is described in Chapter 8.Following the nomenclature of Scanlon et al. (2002b), tracers are grouped into three categories: natural environmental tracers, historical tracers, and applied tracers. Natural environmental tracers are those that are transported to or created within the atmosphere under natural processes; these tracers are carried to the Earth’s surface as wet or dry atmospheric deposition. The most commonly used natural environmental tracer is chloride (Cl) (Allison and Hughes, 1978). Ocean water, through the process of evaporation, is the primary source of atmospheric Cl. Other tracers in this category include chlorine-36 (36Cl) and tritium (3H); these two isotopes are produced naturally in the Earth’s atmosphere; however, there are additional anthropogenic sources of them.

  15. Development of radioisotope tracer technology

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee; Park, Soon Chul; Lim, Dong Soon; Kim, Jae Ho; Lee, Jae Choon; Lee, Doo Sung; Cho, Yong Suk; Shin, Sung Kuan

    2000-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by proton beam and the correlation between the measured activity loss and the amount of wear was established. The equipment was developed to adjust the energy of proton which collides with the surface of tappet. The tracer project team has participated into the tracer test for estimating the efficiency of RFCC system in SK cooperation. From the experiment the tracer team has obtained the primary elements to be considered for judging the efficiency of RFCC unit. By developing the tracer techniques to test huge industrial units like RFCC, the tracer team will be able to support the local industries that require technical services to solve any urgent trouble. (author)

  16. Radioisotope techniques in the study of protein metabolism

    International Nuclear Information System (INIS)

    1965-01-01

    The International Atomic Energy Agency (IAEA) held a panel meeting on June 1-5, 1964. The purpose of the panel was to discuss the present status of radioactive tracer techniques for the study of protein metabolism and to suggest ways of extending an co-ordinating the Agency's research programme in this field. The meeting was attended by 13 invited experts from ten different countries, and three representatives of the World Health Organization (WHO). Sessions of the panel were devoted to methods of preparation of labelled proteins and protein-like substances, to techniques of measurement of gastro-intestinal protein absorption and loss and to the clinical applications of these techniques. At each session, working papers were presented by various participants and then discussed in detail. This report gives the full texts of the working papers together with extensive summaries of the discussions and provides a detailed picture of the present situation and likely future developments in this field of work. It is hoped that its publication will be of interest to all concerned with problems of protein metabolism, whether in clinical medicine or the basic medical sciences. 349 refs, figs and tabs

  17. 11C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies

    International Nuclear Information System (INIS)

    Herlin, G.; Persson, B.; Laangstroem, B.; Aspelin, P.; Bergstroem, M.

    2003-01-01

    Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with 11 C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of 11 C-harmine in 13, and 3 samples did not give a significant level of specific binding of 11 C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of 11 C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary. (orig.)

  18. Positional enrichment by proton analysis (PEPA). A one-dimensional "1H-NMR approach for "1"3C stable isotope tracer studies in metabolomics

    International Nuclear Information System (INIS)

    Vinaixa, Maria; Yanes, Oscar; Rodriguez, Miguel A.; Capellades, Jordi; Aivio, Suvi; Stracker, Travis H.; Gomez, Josep; Canyellas, Nicolau

    2017-01-01

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of "1"3C-satellite peaks using 1D-"1H-NMR spectra. In comparison with "1"3C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of "1"3C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of "1H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  19. Positional enrichment by proton analysis (PEPA). A one-dimensional {sup 1}H-NMR approach for {sup 13}C stable isotope tracer studies in metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Vinaixa, Maria; Yanes, Oscar [Department of Electronic Engineering-Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Rodriguez, Miguel A.; Capellades, Jordi [Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Aivio, Suvi; Stracker, Travis H. [Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (Spain); Gomez, Josep; Canyellas, Nicolau [Department of Electronic Engineering-, Universitat Rovira i Virgili, Tarragona (Spain)

    2017-03-20

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of {sup 13}C-satellite peaks using 1D-{sup 1}H-NMR spectra. In comparison with {sup 13}C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of {sup 13}C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of {sup 1}H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  20. Green River air quality model development: meteorological and tracer data, July/August 1982 field study in Brush Valley, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Whiteman, C.D.; Lee, R.N.; Orgill, M.M.; Zak, B.D.

    1984-06-01

    Meteorological and atmospheric tracer studies were conducted during a 3-week period in July and August of 1982 in the Brush Creek Valley of northwestern Colorado. The objective of the field experiments was to obtain data to evaluate a model, called VALMET, developed at PNL to predict dispersion of air pollutants released from an elevated stack located within a deep mountain valley in the post-sunrise temperature inversion breakup period. Three tracer experiments were conducted in the valley during the 2-week period. In these experiments, sulfur hexafluoride (SF/sub 6/) was released from a height of approximately 100 m, beginning before sunrise and continuing until the nocturnal down-valley winds reversed several hours after sunrise. Dispersion of the sulfur hexafluoride after release was evaluated by measuring SF/sub 6/ concentrations in ambient air samples taken from sampling devices operated within the valley up to about 8 km down valley from the source. An instrumented research aircraft was also used to measure concentrations in and above the valley. Tracer samples were collected using a network of radio-controlled bag sampling stations, two manually operated gas chromatographs, a continuous SF/sub 6/ monitor, and a vertical SF/sub 6/ profiler. In addition, basic meteorological data were collected during the tracer experiments. Frequent profiles of vertical wind and temperature structure were obtained with tethered balloons operated at the release site and at a site 7.7 km down the valley from the release site. 10 references, 63 figures, 50 tables.

  1. Study of seepage losses from irrigation canals using radioactive tracer technique

    International Nuclear Information System (INIS)

    Ahmad, M.; Tariq, J.A.; Rashid, A.; Rafiq, M.; Iqbal, N.

    2004-06-01

    wetted area of the canal. The radiotracer (/sup 99m/Tc) having very short half-life (6 hrs) poses no health hazards as it decays in one day after traveling a very short distance, at the most a few meters. A very small quantity of the tracer required for a test can be met from the leftover activity of /sup 99m/ Tc imported for medical centers. However ECNEC has approved a project produce. /sup 99m/Tc locally at PINSTECH which will ensure its availability at competitive cost. In this study it has been proven that radioactive tracer technique can be used to determine seepage losses from distributaries to biggest canal either unlined or lined in running condition without its closure or disturbing flow. Cost per test based on few tests is about Rs. 100,000/-which could be reduced to Rs. 60,000/-per test for the large scale investigations by creating facilities for drilling and fabrication of filters. The seepage tests can be repeated at the same locations using the existing wells at a cost of Rs. 15000/-. Therefore, this technique is also useful to evaluate the effectiveness of the lining or any other remedial measure. Considering the accuracy of the radiotracer technique and availability of facilities at reasonable cost, this novel technique may be applied at national level. (author)

  2. Biological and Clinical Study of 6-Deoxy-6-Iodo-D-Glucose: a iodinated tracer of glucose transport and of insulin-resistance in human

    International Nuclear Information System (INIS)

    Barone-Rochette, Gilles

    2013-01-01

    Insulin resistance (IR), characterized by a depressed cellular sensitivity to insulin in insulin-sensitive organs, is a central feature to obesity, the metabolic syndrome, and diabetes mellitus and leads to increase cardiovascular diseases, particularly heart failure. All these events are today serious public health problems. But actually, there is no simple tool to measure insulin resistance. The gold standard technique remains the hyperinsulinemic euglycemic clamp. However, the complexity and length of this technique render it unsuitable for routine clinical use. Many methods or index have been proposed to assess insulin resistance in human, but none have shown enough relevance to be used in clinical use. The U1039 INSERM unit previously has validated a new tracer of glucose transport, radiolabelled with 123 iodine and has developed a fast and simple imaging protocol with a small animal gamma camera, which allows the obtaining of an IR index for each organ, showing more discriminating for the heart. The project of my thesis was the human transfer of this measurement technique, perfectly validated in animal. The first part of this thesis evaluated to tolerance, in vivo kinetics, distribution and dosimetry of novel tracer of glucose transport, the [ 123 I]-6DIG. The safeties of new tracer and measurement technique were adequate. There were no adverse effects with excellent tolerance of the whole protocol. 6DIG eliminating was fast, primarily in the urine and complete within 72 h. The effective whole-body absorbed dose for a complete scan with injection of 92.5 * 2 MBq was between 3 to 4 mSv. The second part of this thesis evaluated in human feasibility and reproducibility of the measurement technique validated in animal. The third part showed techniques used to allow human transfer of this method. The study protocol was applied on 12 subjects (healthy volunteers (n=6) and type 2 diabetic patients (n=6)). With a method adapted to measure in humans, we determined an

  3. Study of phenomena of tracer transport and dispersion in fractured media

    International Nuclear Information System (INIS)

    Ippolito, Irene

    1993-01-01

    The objective of this research thesis is to present some transport phenomena according to two different approaches: firstly, the study of flows and tracing in a natural crack within a granitic site, and secondly, the study of flows of different geometries in model cracks, mainly by using techniques of tracer dispersion. The author first presents some properties of fractured media and elements of the theory of the phenomenon of dispersion. She notably discusses the reversibility of the Taylor dispersion which is the prevailing mechanism for simply connected geometries such as in the case of a flow between two continuous solid surfaces limiting a fracture. In the next chapters, the author reports the analysis of characteristics of local structures (mouths, roughnesses) of a single fracture by using echo dispersion. She reports experiments as well as Monte Carlo simulations performed on well defined geometries. In a parallel way, some characteristics measurements (rate-pressure, distribution of flows and tracing in transmission) and mechanical measurements of fracture deformation have been performed on a natural fracture in a granitic site [fr

  4. A pilot study of the behavior of gas- and particle-phase ETS tracers in residences

    International Nuclear Information System (INIS)

    Apte, Michael; Gundel, Lara; Dod, Raymond; Chang, Gee-Min; Sextro, Richard

    2002-01-01

    Our previous study of environmental tobacco smoke (ETS) in a three-room environmental chamber showed that smoking history significantly influenced inter-room ETS transport, particularly of gas-phase nicotine. We conducted a three-home pilot study where smoking was limited to one room. Single-smoker residences were monitored during five one-week periods while the smoker participated in a smoking cessation program. Nicotine traced ETS particles were detected reliably in the smoking rooms (SRs) and unreliably in the non-smoking rooms (NSRs). On average, the ventilation- and volume-normalized smoking rate, 0.1 Cigarette-h(sup -1) m(sup -3), added about 17 and 4(micro)g m(sup -3) of ETS particles into the SR and NSR, while average nicotine concentration increases were 2 and 0.06(micro)g m(sup -3), respectively. Thus, nicotine tracers may underestimate ETS particle exposure in a NSR (e.g., a child's bedroom) by a factor of 2 to 8. In other words, ETS exposure predicted from nicotine concentrations could be almost an order of magnitude lower than actual exposure

  5. Techniques necessary for multiple tracer quantitative small-animal imaging studies

    International Nuclear Information System (INIS)

    Sharp, Terry L.; Dence, Carmen S.; Engelbach, John A.; Herrero, Pilar; Gropler, Robert J.; Welch, Michael J.

    2005-01-01

    Introduction: An increasing number and variety of studies on rodent models are being conducted using small-animal positron emission tomography scanners. We aimed to determine if animal handling techniques could be developed to perform routine animal imaging in a timely and efficient manner and with minimal effect on animal physiology. These techniques need to be reproducible in the same animal while maintaining hemodynamic and physiological stability. Methods: The necessary techniques include (a) the use of inhalant anesthesia, (b) arterial and venous cannulation for multiple tracer administrations and blood sampling, (c) development of small-volume analytic columns and techniques and (d) measurement of the physiological environment during the imaging session. Results: We provide an example of a cardiac imaging study using four radiotracers ( 15 O-water, 1-[ 11 C]-acetate, 1-[ 11 C]-palmitate and 1-[ 11 C]-glucose) injected into normal rats. Plasma substrates, CO 2 production and total metabolites were measured. The animals remained anesthetized over the entire imaging session, and their physiological state was maintained. Conclusion: The intrastudy stability of the physiological measurements and substrate levels and interstudy reproducibility of the measurements are reported

  6. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

    International Nuclear Information System (INIS)

    Stetzenbach, K.; Farnham, I.

    1996-01-01

    Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test

  7. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stetzenbach, K.; Farnham, I.

    1996-06-01

    Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test.

  8. Geostatistical and Stochastic Study of Flow and Tracer Transport in the Unsaturated Zone at Yucca Mountain

    International Nuclear Information System (INIS)

    Ye, Ming; Pan, Feng; Hu, Xiaolong; Zhu, Jianting

    2007-01-01

    Yucca Mountain has been proposed by the U.S. Department of Energy as the nation's long-term, permanent geologic repository for spent nuclear fuel or high-level radioactive waste. The potential repository would be located in Yucca Mountain's unsaturated zone (UZ), which acts as a critical natural barrier delaying arrival of radionuclides to the water table. Since radionuclide transport in groundwater can pose serious threats to human health and the environment, it is important to understand how much and how fast water and radionuclides travel through the UZ to groundwater. The UZ system consists of multiple hydrogeologic units whose hydraulic and geochemical properties exhibit systematic and random spatial variation, or heterogeneity, at multiple scales. Predictions of radionuclide transport under such complicated conditions are uncertain, and the uncertainty complicates decision making and risk analysis. This project aims at using geostatistical and stochastic methods to assess uncertainty of unsaturated flow and radionuclide transport in the UZ at Yucca Mountain. Focus of this study is parameter uncertainty of hydraulic and transport properties of the UZ. The parametric uncertainty arises since limited parameter measurements are unable to deterministically describe spatial variability of the parameters. In this project, matrix porosity, permeability and sorption coefficient of the reactive tracer (neptunium) of the UZ are treated as random variables. Corresponding propagation of parametric uncertainty is quantitatively measured using mean, variance, 5th and 95th percentiles of simulated state variables (e.g., saturation, capillary pressure, percolation flux, and travel time). These statistics are evaluated using a Monte Carlo method, in which a three-dimensional flow and transport model implemented using the TOUGH2 code is executed with multiple parameter realizations of the random model parameters. The project specifically studies uncertainty of unsaturated flow

  9. Application of Stable Isotope-Assisted Metabolomics for Cell Metabolism Studies

    Science.gov (United States)

    You, Le; Zhang, Baichen; Tang, Yinjie J.

    2014-01-01

    The applications of stable isotopes in metabolomics have facilitated the study of cell metabolisms. Stable isotope-assisted metabolomics requires: (1) properly designed tracer experiments; (2) stringent sampling and quenching protocols to minimize isotopic alternations; (3) efficient metabolite separations; (4) high resolution mass spectrometry to resolve overlapping peaks and background noises; and (5) data analysis methods and databases to decipher isotopic clusters over a broad m/z range (mass-to-charge ratio). This paper overviews mass spectrometry based techniques for precise determination of metabolites and their isotopologues. It also discusses applications of isotopic approaches to track substrate utilization, identify unknown metabolites and their chemical formulas, measure metabolite concentrations, determine putative metabolic pathways, and investigate microbial community populations and their carbon assimilation patterns. In addition, 13C-metabolite fingerprinting and metabolic models can be integrated to quantify carbon fluxes (enzyme reaction rates). The fluxome, in combination with other “omics” analyses, may give systems-level insights into regulatory mechanisms underlying gene functions. More importantly, 13C-tracer experiments significantly improve the potential of low-resolution gas chromatography-mass spectrometry (GC-MS) for broad-scope metabolism studies. We foresee the isotope-assisted metabolomics to be an indispensable tool in industrial biotechnology, environmental microbiology, and medical research. PMID:24957020

  10. Tracer-based quantification of individual frac discharge in single-well multiple-frac backflow: sensitivity study

    Science.gov (United States)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2014-05-01

    Within the deep-geothermal research project at GroßSchönebeck in the NE German Basin, targeting volcanic rocks (Lower Rotliegend) and siliciclastics (Upper Rotliegend) in the Lower Permian by means of a well doublet with several screening intervals between 3815 and 4247 m b.s.l., several artificial fractures with different geometric and hydraulic characteristics were created at each well, aiming to increase reservoir performance [1], [2]. It could not be told a priori which of the various fracturing treatments was to prove as most promising in terms of future reservoir productivity. At the intended-production well (GS-4), one large-area waterfrac was created in the low-permeability volcanic rocks, and two gel-proppant fractures in selected sandstone layers. Each fracturing treatment was accompanied by the injection of a water-dissolved tracer slug, followed by a defined volume of tracer-free ('chaser') fluid [3]. Each frac received a different species of a sulfonated aromatic acid salt, as a conservative water tracer. During subsequent backflow tests (either gas-based lifting, or production by means of a downhole submersible pump), each frac can contribute a certain (more or less constant) amount to the measured total discharge (also depending on whether and when each frac 'starts' contributing, and which effective aperture and area it actually 'manifests' during the process). Since these individual-frac discharge amounts cannot be measured directly, it was endeavoured to indirectly determine ('resolve') them from tracer signals as detectable in the overall backflow discharge. Therefore, we need to examine how these tracer signals depend on local discharge values and on local hydrogeologic parameters (matrix porosity, permeability distribution; frac transmissivity, thickness, effective area and aperture), and to what extent hydrogeological uncertainty will impede the inversion of local discharge values. To this end, a parameter sensitivity study was conducted on

  11. Study on chromium speciation in rats by the isotope tracer technique

    International Nuclear Information System (INIS)

    Feng Weiyue; Qian Qinfang; Ding Wenjun; Chai Zhifang

    1999-01-01

    The chromium speciation in the liver cytosol fraction, serum and urine of both normal and diabetic rats are studied by the enriched stable isotope tracer technique combined with the get chromatography and the neutron activating analysis (NAA). The results are as follows: (1) When Cr(III) enters the animal body, it is most likely to be combined with serum proteins. The chromium-protein compound acts as a carrier to transport Cr to the whole body. In the liver cytosol fraction, Cr (III) is also mainly combined with the high molecular weight protein and retains as chromium-protein substance in the liver. (2) A low molecular weight chromium-containing compound is found in all the liver cell cytosol fraction, serum and urine of the two group rats. (3) The diabetic rats lose more amount of low molecular weight of chromium compound in urine than the normal rats do. This might be a main reason to explain why the diabetic rats retain lower Cr in their bodies than the normal group

  12. A study of the behavior of a cathode film formed in chromium plating with radioactive tracers

    International Nuclear Information System (INIS)

    Yoshida, Katsuyoshi; Suzuki, Akihira; Doi, Kazuyuki; Arai, Katsutoshi

    1979-01-01

    The behavior and composition of a cathode film formed on a steel cathode during chromium plating were studied with radioactive tracers. A special cell with a rapid washing compartment was used for preventing the cathode film from dissolving in electrolyte after plating. The cathode film was composed of two layers. The outer layer facing to the electrolyte had a loose structure and contained more sulfuric anions than the inner layer, for sulfuric acid probably concentrated in the outer layer. This outer layer is called L-film in this paper. The L-film was easily dissolved in the electrolyte solution. The inner layer (called C-film, compact film) was stable against electrolytes and contained less anions than that of L-film. The C-film had a thickness equivalent to 5 mg/m 2 and the concentration of anions unaffected by the composition of electrolytes. The C-film was not reduced to metallic chromium, but it remained in the cathode film during and after plating. This suggests that chromic acid in the cathode film is not reduced to metallic chromium, that metallic chromium is deposited from chromium complexes reaching the cathode surface through the cathode film, and that the complexes do not play a role on the construction of the cathode film. (author)

  13. Electron microscopic studies on ameloblast using /sup 45/Ca as tracer

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K [Gifu Univ. (Japan). Faculty of Medicine

    1974-02-01

    In order to study the functional role of ameloblast on inorganic substance, electron microscopic autoradiography was prepared from dental germ of incisor and molar teeth of young rats using /sup 45/Ca as the tracer and following results were obtained. At 15 minutes after /sup 45/Ca administration, /sup 45/Ca appeared in cells of each stage of development, reaching the peak after 30 minutes and gradually shifting from the inside of cells to matrix. /sup 45/Ca was localized in the cells in the nuclear substance, rough surfaced endoplasmic reticulum, Golgi area and mitochondria. Especially in the mitochondria, silver grains are accumulated in high concentration, suggesting a major role in the storage and accumulation of Ca. /sup 45/Ca passed through the mature ameloblasts rapidly. After 15 minutes, silver grains were noted in the matrix formation. After 2 hours, scarcely any silver grains were noted in the cells, most of them being shifted to calcifing area from the matrix formation. As the pathway of transport of /sup 45/Ca, intracellular passage is mainly adopted in the stage of matrix formation, without transport through the intercellular space. Even if a considerable separation occurred between each cell in the mature stage, no silver grains were noted in this area. These results would indicate an important role of ameloblast in the transport and storage of inorganic substances through the movement of Ca.

  14. Lead isotope ratios as a tracer for lead contamination sources: A lake Andong case study

    Directory of Open Access Journals (Sweden)

    Kim Y. H

    2013-04-01

    Full Text Available The objective of this study was to evaluate stable Pb isotope signatures as a tracer for Pb contamination in Lake Andong. For Pb isotope analysis, we collected water and sediment from Lake Andong, particles in the air, soils, and stream water, mine tailings, sludge and wastewater from zinc smelting around lake Andong watershed. The results showed that Pb isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for zinc concentrate were 18.809 ± 0.322, 15.650 ± 0.062, and 38.728 ± 0.421, respectively. In wastewater, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb were 17.363 ± 0.133, 15.550 ± 0.025, and 37.217 ± 0.092, respectively. Additionally, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for sludge were 17.515 ± 0.155, 15.537 ± 0.018, and 37.357 ± 0.173, respectively. These values were similar to those in zinc and lead concentrate originated from Canada and South America. In contrast, Pb isotope ratios of soil, tailings and sediment from Lake Andong were similar to those of Korean ore. Atmospheric particles showed different patterns of Pb isotope ratios from sediments, soils, and zinc smelting and this needs further investigation in order to identify atmospheric Pb sources.

  15. Fate of thymic lymphocytes. [/sup 125/IudR and /sup 3/HTdR tracer studies in mice

    Energy Technology Data Exchange (ETDEWEB)

    Laissue, J A; Chanana, A D; Cronkite, E P; Joel, D D

    1976-01-01

    Data are summarized from a number of studies on the fate of thymic lymphocytes. Results are reported from studies in mice in which /sup 125/IudR and /sup 3/HTdR were used as tracers to study the production, maturation, migration, and life span of thymic lymphocytes. It is pointed out that thymus-derived cells constitute the majority of recirculating lymphocytes and that peripheral, differentiated thymus-derived lymphocytes exhibit a number of immunological functions. 114 references.

  16. Application of radioisotope tracer techniques in studies on host-parasite relationships, with special reference to larval trematodes. A review

    International Nuclear Information System (INIS)

    Christensen, N.Oe.

    1981-01-01

    The application of radioisotope tracer techniques in studies on various host-parasite relationships between larval trematodes and their intermediate and definite hosts is reviewed. Such studies comprise, for example, the reproduction and nutrition of various developmental stages of trematodes in relation to host and environment. The preparation and application of radiolabelled larvae are also discussed with special emphasis on their use in studies on free-living ecology and migration in hosts. (author)

  17. Local study of pollutants dispersion by a real time tracer method

    International Nuclear Information System (INIS)

    Faivre-Pierret, R.X.; Sestier-Carlin, R.; Berne, P.

    1992-01-01

    It is possible to use a Gaussian mathematical model of atmospheric dispersion for calculating atmospheric transfer coefficient (ATC) in long range model, but for proximity models, an experimental model using a tracer technic has to take in account ground effects and natural or artificial obstacles. SF 6 tracer method gives the true plume ground trace in real time. The measured ATC shows a larger ground trace, lower concentration in the axis, and a displacement of the maximum concentration with regard to wind axis in comparison with the calculated ATC. (A.B.). 14 refs., 4 figs., 1 tab

  18. Using Temperature as a Tracer to Study Fluid Flow Patterns On and Offshore Taiwan

    Science.gov (United States)

    Chi, W. C.

    2017-12-01

    Fluid flows are a dynamic system in the crust that affect crustal deformation and formation of natural resources. It is difficult to study fluid flow velocity instrumentally, but temperature data offers a quantitative tool that can be used as a tracer to study crustal hydrogeology. Here we present numerical techniques we have applied to study the fluid migration velocity along conduits including faults in on and offshore settings. Offshore SW Taiwan, we use a bottom-simulating reflector (BSR) from seismic profiles to study the temperature field at several hundred meters subbottom depth. The BSR is interpreted as the base of a gas hydrate stability zone under the seabed. Gas hydrates are solid-state water with gas molecules enclosed, which can be found where the temperature, pressure, and salinity conditions allow hydrates to be stable. Using phase diagrams and hydro pressure information we can derive the temperature at the BSR. BSRs are widespread in the study area, providing very dense temperature field information which shows upward bending of the BSR near faults. We have quantitatively estimated the 1D and 2D fluid flow patterns required to fit the BSR-based temperature field. This shows that fault zones can act as conduits with high permeability parallel to the fault planes. On the other hand, fault zones can also act as barriers to fluid flow, as demonstrated in our onland temperature data. We have collected temperature profiles at several bore holes onland that are very close together. The preliminary results show that the fault zones separate the ground water systems, causing very different geothermal gradients. Our results show that the physical properties of fault zones can be anisotropic, as demonstrated in previous work. Future work includes estimating the regional water expulsion budget offshore SW Taiwan, in particular for several gas hydrate sites.

  19. Teacher Education Graduate Tracer Study from 2010 to 2014 in One State University in Batangas, Philippines

    Directory of Open Access Journals (Sweden)

    Anania B. Aquino

    2015-12-01

    Full Text Available Teacher Education institutions primarily aim of producing competent and highly qualified graduates employable here and abroad. Tracer studies on graduates can appropriately provide valuable information for evaluating the results of the education and training of a specific institution of higher education. It collects essential information concerning the employment profile of graduates, their undergraduate experience, the first and current jobs of graduates and the relevance of their educational background and skills required in their job. The main objective of this study was to trace the employment profile of the graduates after they obtained their teacher education degree. The descriptive survey method of research was applied to this research with a survey questionnaire as the main data gathering instrument. It analyzed data from 129 respondents characterized by a preponderance of females over male as females and unmarried or single graduates as opposed to those who were married. The study found that there were more respondents who finished Bachelor of Secondary Education (BSED over Bachelor of Elementary Education. They obtained this degree as they believed that teaching is a rewarding and challenging profession, Majority are Licensure Examination for Teachers (LET passers and are employed in public schools at the time of the study. Their present job, mostly professional in nature, was also their first job and relevant to their degree. It took only a moderate period of time for most graduates to land a job. Most stay in their job for economic reason, finding communication skills and human relation skills as part of their teacher education preparation very relevant to their jobs.

  20. Metabolic imaging using SPECT

    International Nuclear Information System (INIS)

    Taki, Junichi; Matsunari, Ichiro

    2007-01-01

    In normal condition, the heart obtains more than two-thirds of its energy from the oxidative metabolism of long chain fatty acids, although a wide variety of substrates such as glucose, lactate, ketone bodies and amino acids are also utilised. In ischaemic myocardium, on the other hand, oxidative metabolism of free fatty acid is suppressed and anaerobic glucose metabolism plays a major role in residual oxidative metabolism. Therefore, metabolic imaging can be an important technique for the assessment of various cardiac diseases and conditions. In SPECT, several iodinated fatty acid traces have been introduced and studied. Of these, 123 I-labelled 15-(p-iodophenyl)3-R, S-methylpentadecanoic acid (BMIPP) has been the most commonly used tracer in clinical studies, especially in some of the European countries and Japan. In this review article, several fatty acid tracers for SPECT are characterised, and the mechanism of uptake and clinical utility of BMIPP are discussed in detail. (orig.)

  1. Development and evaluation of a tracer-injection hydrothermal technique for studies of waste package interactions

    International Nuclear Information System (INIS)

    Jones, T.E.; Coles, D.G.; Britton, R.C.; Burnell, J.R.

    1986-11-01

    A tracer-injection system has been developed for use in characterizing reactions of waste package materials under hydrothermal conditions. High-pressure liquid chromatographic instrumentation has been coupled with Dickson-type rocking autoclaves to allow injection of selected components into the hydrothermal fluid while maintaining run temperature and pressure. Hydrothermal experiments conducted using this system included the interactions of depleted uranium oxide and Zircaloy-4 metal alloy discs with trace levels of 99 Tc and non-radioactive Cs and I in a simulated groundwater matrix. After waste-package components and simulated waste forms were pre-conditioned in the autoclave systems (usually 4 to 6 weeks), known quantities of tracer-doped fluids were injected into the autoclaves' gold reaction bag at run conditions. Time-sequenced sampling of the hydrothermal fluid providing kinetic data on the reactions of tracers with waste package materials. The injection system facilitates the design of experiments that will better define ''steady-state'' fluid compositions in hydrothermal reactions. The injection system will also allow for the formation of tracer-bearing solid phases in detectable quantities

  2. Tracer element studies on deep water formation and circulation in the European Artic Sea

    International Nuclear Information System (INIS)

    Boenisch, G.

    1991-01-01

    Tracer element investigations (tritium, helium 3, carbon 14, argon 39, krypton 85 and fluorohydrocarbons) were carried out in the European Arctic Sea. The findings are discussed with a view to their validity in the case of deep water formation and circulation. The data cover the period of 1972 through 1989. (BBR) [de

  3. Studies applications through tracers techniques and effluent contaminants dispersing in Montevideo coastal waters and east beaches

    International Nuclear Information System (INIS)

    Suarez, R.; Dellepere, A.; Pintos, A.; Barreiro, M.; Odino, R.; Souto, B.; Badano, A.; Crosignani, L.; Moreno, S.

    1995-01-01

    With the purpose to define or not the contamination influence in Montevideo coastal waters, uranine and tritium tracers were injected in outlet river. A higher grade of contamination was found in the Montevideo Bay, and several recommendations were given for the future

  4. Stable isotope tracers and exercise physiology: past, present and future.

    Science.gov (United States)

    Wilkinson, Daniel J; Brook, Matthew S; Smith, Kenneth; Atherton, Philip J

    2017-05-01

    Stable isotope tracers have been invaluable assets in physiological research for over 80 years. The application of substrate-specific stable isotope tracers has permitted exquisite insight into amino acid, fatty-acid and carbohydrate metabolic regulation (i.e. incorporation, flux, and oxidation, in a tissue-specific and whole-body fashion) in health, disease and response to acute and chronic exercise. Yet, despite many breakthroughs, there are limitations to 'substrate-specific' stable isotope tracers, which limit physiological insight, e.g. the need for intravenous infusions and restriction to short-term studies (hours) in controlled laboratory settings. In recent years significant interest has developed in alternative stable isotope tracer techniques that overcome these limitations, in particular deuterium oxide (D 2 O or heavy water). The unique properties of this tracer mean that through oral administration, the turnover and flux through a number of different substrates (muscle proteins, lipids, glucose, DNA (satellite cells)) can be monitored simultaneously and flexibly (hours/weeks/months) without the need for restrictive experimental control. This makes it uniquely suited for the study of 'real world' human exercise physiology (amongst many other applications). Moreover, using D 2 O permits evaluation of turnover of plasma and muscle proteins (e.g. dynamic proteomics) in addition to metabolomics (e.g. fluxomics) to seek molecular underpinnings, e.g. of exercise adaptation. Here, we provide insight into the role of stable isotope tracers, from substrate-specific to novel D 2 O approaches, in facilitating our understanding of metabolism. Further novel potential applications of stable isotope tracers are also discussed in the context of integration with the snowballing field of 'omic' technologies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  5. Sample size calculation in metabolic phenotyping studies.

    Science.gov (United States)

    Billoir, Elise; Navratil, Vincent; Blaise, Benjamin J

    2015-09-01

    The number of samples needed to identify significant effects is a key question in biomedical studies, with consequences on experimental designs, costs and potential discoveries. In metabolic phenotyping studies, sample size determination remains a complex step. This is due particularly to the multiple hypothesis-testing framework and the top-down hypothesis-free approach, with no a priori known metabolic target. Until now, there was no standard procedure available to address this purpose. In this review, we discuss sample size estimation procedures for metabolic phenotyping studies. We release an automated implementation of the Data-driven Sample size Determination (DSD) algorithm for MATLAB and GNU Octave. Original research concerning DSD was published elsewhere. DSD allows the determination of an optimized sample size in metabolic phenotyping studies. The procedure uses analytical data only from a small pilot cohort to generate an expanded data set. The statistical recoupling of variables procedure is used to identify metabolic variables, and their intensity distributions are estimated by Kernel smoothing or log-normal density fitting. Statistically significant metabolic variations are evaluated using the Benjamini-Yekutieli correction and processed for data sets of various sizes. Optimal sample size determination is achieved in a context of biomarker discovery (at least one statistically significant variation) or metabolic exploration (a maximum of statistically significant variations). DSD toolbox is encoded in MATLAB R2008A (Mathworks, Natick, MA) for Kernel and log-normal estimates, and in GNU Octave for log-normal estimates (Kernel density estimates are not robust enough in GNU octave). It is available at http://www.prabi.fr/redmine/projects/dsd/repository, with a tutorial at http://www.prabi.fr/redmine/projects/dsd/wiki. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  6. An improved method for analysis of In-EDTA, I- and Br- used as active tracers in hydrological studies

    International Nuclear Information System (INIS)

    Stanescu, S.P.; Spiridon, S.

    1992-01-01

    Neutron activation analysis combined with chemical preconcentration of the elements in water samples can give a high sensitivity in the determination of concentrations for In-EDTA, I - and Br - used as active tracers in hydrological studies. The authors have developed an improved method of analysis which is sensitive, selective and applicable to a wide range of underground and surface water samples including those having a high concentration of manganese ions. (author) 6 refs.; 2 figs.; 1 tab

  7. Use of radon-222 as a tracer in the study of atmospheric diffusion

    International Nuclear Information System (INIS)

    Ikebe, Y.; Yamada, H.; Nishimura, T.; Kojima, S.; Shimo, M.; Yamanishi, H.; Tojyo, K.; Iida, T.; Chino, M.

    1991-01-01

    222 Rn is one of the most useful tracer for studying the atmospheric diffusion. In this report, first we report analytical treatments about temporal variation of Rn concentration in the atmosphere to clarify origin and transport of Rn. Secondly we report the numerical simulation of the behavior of Rn. The results is compared with the observed Rn concentration for confirming the validity of the simulation. Based on the results of numerical analysis of a diffusion equation, we assumed that Rn concentration measured at Nagoya can be divided into the following two components: (I) Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. For this, it was shown that the measured temporal variation can be explained by using ordinary non-steady state one dimensional diffusion equation. (II) Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose a one layer transport model using air mass trajectory technique. By this model we can explain well the temporal variation of back-ground component and seasonal variation of Rn at Nagoya. A numerical simulation of the temporal variation of Rn was carried out for meso-regional scale (200kmx200kmx1km). The results was compared with the continuous measurements of Rn concentration at Nagoya, and fairly good agreements was obtained. We have obtained horizontal distributions of Rn around Nagoya (150kmx150km) for each season by using a passive method. The linear relationship between Rn concentration and measured Rn exhalation rate supports the transport model mentioned above and gives us other interesting informations. (author)

  8. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    International Nuclear Information System (INIS)

    Schmidt, Axel

    2008-01-01

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies

  9. Two dimensional model study of atmospheric transport using carbon-14 and strontium-90 as inert tracers

    International Nuclear Information System (INIS)

    Kinnison, D.E.; Wuebbles, D.J.; Johnston, H.S.

    1992-02-01

    This study tests the transport processes in the LLNL two-dimensional chemical-radiative-transport model using recently reanalyzed carbon-14 and strontium-90 data. These radioactive tracers were produced bythe atmospheric nuclear bomb tests of 1952--58 and 1961--62, and they were measured at a few latitudes up to 35 kilometers over the period 1955--1970. Selected horizontal and vertical eddy diffusion coefficients were varied in the model to test their sensitivity to short and long term transpose of carbon-14. A sharp transition of K zz and K yy through the tropopause, as opposed to a slow transition between the same limiting values, shows a distinct improvement in the calculated carbon-14 distributions, a distinct improvement in the calculated seasonal and latitudinal distribution of ozone columns (relative to TOMS observations), and a very large difference in the calculated ozone reduction by a possible fleet of High Speed Civil Transports. Calculated northern hemisphere carbon-14 is more sensitive to variation of K yy than are global ozone columns. Strontium-90 was used to test the LLNL tropopause height at four different latitudes. Starting with the 1960 background distribution of carbon-14, we calculate the input of carbon-14 as the sum of each nuclear test of the 1961--62 series, using two bomb-cloud rise models. With the Seitz bomb-rise formulation in the LLNL model, we find good agreement between calculated and observedcarbon-14 (with noticeable exceptions at the north polar tropopause and the short-term mid-latitude mid-stratosphere) between 1963 and 1970

  10. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Axel

    2008-06-27

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies.

  11. You are not always what we think you eat. Selective assimilation across multiple whole-stream isotopic tracer studies

    International Nuclear Information System (INIS)

    Dodds, W. K.; Collins, S. M.; Hamilton, S. K.; Johnson, S.; Webster, J. R.; Simon, K. S.; Whiles, M. R.; Rantala, H. M.; McDowell, W. H.; Peterson, S. D.; Riis, T.; Crenshaw, C. L.; Thomas, S. A.; Kristensen, P. B.; Cheever, B. M.; Flecker, A. S.; Griffiths, N. A.; Crowl, T.; Rosi-Marshall, E. J.; El-Sabaawi, R.; Marti, E.

    2014-01-01

    Analyses of 21 15 N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33-50% of the N available in sampled food sources such as decomposing leaves, epilithon, and fine particulate detritus over feeding periods of weeks or more. Thus, common methods of sampling food sources consumed by animals in streams do not sufficiently reflect the pool of N they assimilate. Lastly, Isotope tracer studies, combined with modeling and food separation techniques, can improve estimation of N pools in food sources that are assimilated by consumers

  12. Study on bioavailability of zinc for children's diet by using activable isotopic tracer 70Zn and neutron activation analysis techniques

    International Nuclear Information System (INIS)

    Zhang Yangmei; Ni Bangfa; Wang Pingsheng; Tian Weizhi; Cao Lei

    2001-01-01

    Bioavailability of zinc for three groups (low amount of diet zinc, balance amount of diet zinc and high amount of diet zinc) of children's diet is studied by using activable isotopic tracer 70 Zn and neutron activation analysis techniques. The results indicate that the fractional absorption of zinc from balance diet zinc group is the highest, up to 33.9%. A procedure of pre-irradiation concentration zinc for fecal samples using anion exchanger is developed, and the enriched 70 Zn with isotopic abundance of 18.3% is used for tracer. The mass ratios between 70 Zn and 68 Zn or 64 Zn and their contents between natural zinc and enriched zinc are used to calculate the bioavailability of zinc. Instrumental neutron activation analysis of 64 Zn of each original fecal samples and pre-irradiation concentrated zinc samples are used to normalize the chemical yield in order to reduce the uncertainty during the chemical separation procedure

  13. Delayed clearance of cerebrospinal fluid tracer from entorhinal cortex in idiopathic normal pressure hydrocephalus: A glymphatic magnetic resonance imaging study.

    Science.gov (United States)

    Eide, Per K; Ringstad, Geir

    2018-01-01

    The glymphatic system plays a key role for clearance of waste solutes from the rodent brain. We recently found evidence of glymphatic circulation in the human brain when using magnetic resonance imaging (MRI) contrast agent as cerebrospinal fluid (CSF) tracer in conjunction with multiple MRI acquisitions (gMRI). The present study explored the hypothesis that reduced glymphatic clearance in entorhinal cortex (ERC) may be instrumental in idiopathic normal pressure hydrocephalus (iNPH) dementia. gMRI acquisitions were obtained over a 24-48 h time span in cognitively affected iNPH patients and non-cognitively affected patients with suspected CSF leaks. The CSF tracer enrichment was determined as changes in normalized MRI T1 signal units. The study included 30 patients with iNPH and 8 individuals with suspected CSF leaks (i.e. reference individuals). Compared to reference individuals, iNPH patients presented with higher medial temporal lobe atrophy score and Evan's index and inferior ERC thickness. We found delayed clearance of the intrathecal CSF tracer gadobutrol from CSF, the ERC and adjacent white matter, suggesting impaired glymphatic circulation. Reduced clearance and accumulation of toxic waste product such as amyloid-β may be a mechanism behind dementia in iNPH. Glymphatic MRI (gMRI) may become a tool for assessment of early dementia.

  14. Bottom sediment transport study at Haiphong port using radioactive scandium as tracer

    International Nuclear Information System (INIS)

    Pham Ngoc Chuong; Phan Son Hai; Pham Duy Hien

    1993-01-01

    A radioisotope tracer experiment was performed for investigating the bedload movement at the site near the access channel to Haiphong port, North Vietnam. The scandium glass and a number of mechanical devices were manufactured locally for the experiment. Simple and safe procedures were adopted for the production, transportation and injection of radioactive tracer materials. Five tracking experiments were carried out covering the period of 84 days in winter 1992-1993. The experimental results provide a firm basis for elaborating appropriate measures against the siltation problem at Haiphong port, especially for the design of a new access channel with a better orientation with respect to the directions of the water flow and bedload transport, as proposed recently by the Port Authority. (Author). 2 refs, 4 figs

  15. Study on development of evaluation technique of in-situ tracer test in Horonobe Underground Research Laboratory project (Contract research)

    International Nuclear Information System (INIS)

    Yokota, Hideharu; Amano, Kenji; Maekawa, Keisuke; Kunimaru, Takanori; Naemura, Yumi; Ijiri, Yuji; Motoshima, Takayuki; Suzuki, Shunichi; Teshima, Kazufumi

    2013-06-01

    In the Horonobe Underground Research Laboratory Project, in-situ tracer tests are valuable and important as the investigations to obtain the mass transportation data of fractures in hostrock. However, it is difficult that the in-situ tests are executed under various conditions due to long test period and the tests results are evaluated about permeable heterogeneity in a fracture and/or scale effects. In this study, a number of tracer tests are simulated in a fictitious single plate fracture generated on computer. And the transport parameters are identified by fitting one- and two-dimensional models to the breakthrough curves obtained from the simulations in order to investigate the applicability of these models to the evaluation of in-situ tracer test. As a result, one-dimensional model yields larger longitudinal dispersion length than two-dimensional model in the both cases of homogeneous and heterogeneous hydraulic conductivity fields of the fictitious fracture. This is because that the effect of transverse dispersion has to be included in the longitudinal dispersion length parameter in the one-dimensional model. It is also found that the larger dipole ratio and the larger natural groundwater flow crossing the flow generated between two boreholes make the identified longitudinal dispersion length larger. And, the longitudinal dispersion length identified from a tracer test is smaller and/or larger than the macroscopic longitudinal dispersion length identified from whole fracture. It is clarified that these are occurred by shorter or longer distance between boreholes compare to the correlation length of geostatistical heterogeneity of fictitious fracture. (author)

  16. The Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRA*CER) trial: study design and rationale.

    Science.gov (United States)

    2009-09-01

    The protease-activated receptor 1 (PAR-1), the main platelet receptor for thrombin, represents a novel target for treatment of arterial thrombosis, and SCH 530348 is an orally active, selective, competitive PAR-1 antagonist. We designed TRA*CER to evaluate the efficacy and safety of SCH 530348 compared with placebo in addition to standard of care in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and high-risk features. TRA*CER is a prospective, randomized, double-blind, multicenter, phase III trial with an original estimated sample size of 10,000 subjects. Our primary objective is to demonstrate that SCH 530348 in addition to standard of care will reduce the incidence of the composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization compared with standard of care alone. Our key secondary objective is to determine whether SCH 530348 will reduce the composite of cardiovascular death, MI, or stroke compared with standard of care alone. Secondary objectives related to safety are the composite of moderate and severe GUSTO bleeding and clinically significant TIMI bleeding. The trial will continue until a predetermined minimum number of centrally adjudicated primary and key secondary end point events have occurred and all subjects have participated in the study for at least 1 year. The TRA*CER trial is part of the large phase III SCH 530348 development program that includes a concomitant evaluation in secondary prevention. TRA*CER will define efficacy and safety of the novel platelet PAR-1 inhibitor SCH 530348 in the treatment of high-risk patients with NSTE ACS in the setting of current treatment strategies.

  17. Study of solid and liquid behavior in large copper flotation cells (130 m2) using radioactive tracers

    International Nuclear Information System (INIS)

    Diaz, F.; Jimenez, O.; Yianatos, J.; Contreras, F.

    2013-01-01

    The behavior of the solid and liquid phases, in large flotation cells, was characterized by means of the radioactive tracer technique. The use of radioactive tracers enabled the identification of the Residence Time Distribution, of floatable and non-floatable solid, from continuous (on-line) measuring at the output streams of the flotation cells. For this study, the proper radioactive tracers were selected and applied in order to characterize the different phases; i.e. for liquid phase Br-82 as Ammonium Bromide, for floatable solid recovered in the concentrate Cu-64, and for non-floatable solid in three particle size classes (coarse: >150 μm, intermediate: 45 μm, and fine: <45 μm), Na-24. The experimental results confirmed the strong effect of particle size on the Residence Time Distribution, and mean residence time of solids in larger flotation cells, and consequently in flotation hydrodynamics. From a hydrodynamic point of view, the experimental data confirmed that a single mechanical flotation cells, of large size, can deviate significantly from perfect mixing. The experimental work was developed in a 130 m3 industrial flotation cell of the rougher circuit at El Teniente Division, Codelco-Chile. (authors)

  18. Prospect of radon as a tracer in studying of landslide forecast

    International Nuclear Information System (INIS)

    Zhang Huifeng; Ding Dexin

    2004-01-01

    Radon, as a chemical element of radioactivity, is widely used in the fields of earth-quake monitoring, prospecting mine and exploring resource. This paper discussed the theory of radon's separating out from the soil and the theory and means of surveying radon. It also relates the radon anomaly in the measuring process of soil radon, caused by the interferring of the environmental factors in measurement results. It further clarifies the wilde application of radon as a tracer in landslide forecast. (authors)

  19. Application of 123I-labelled long-chained fatty acids for the study of myocardial metabolism

    International Nuclear Information System (INIS)

    Freundlieb, C.; Hoeck, A.; Vyska, F.; Feinendegen, L.E.; Machulla, H.J.; Stoecklin, G.

    1978-01-01

    Radioiodine-labelled fatty acids are useful tracers for myocardial imaging. The present study extends myocardial scintigraphy with ω-123-I-heptadecanoic acid to measuring myocardial metabolism. 4 normal individuals and 6 patients with cardiac disease received i.v. 1-2 mCi ω-123-I-heptadecanoic acid. Immediately fast serial scintigrams of the myocardium were taken for 30 minutes. Disappearance of the tracer, and appearance of anorganic 123-I, was measured in the peripheral blood. The myocardial images were of high quality later than 5 minutes after injection. By correcting for anorganic 123-I in the peripheral blood and the interstitium, the turnover of tracer in the myocardial cells could be measured. Activity was lost from the myocardium with a half time between 14 and 32 minutes. Within regions of old myocardials infarctions the half time of tracer loss was prolonged. The data clearly indicate the feasibility of using ω-123-I-heptadecanoic acid for measuring myocardial metabolism. (author)

  20. A comparative modeling study of a dual tracer experiment in a large lysimeter under atmospheric conditions

    Science.gov (United States)

    Stumpp, C.; Nützmann, G.; Maciejewski, S.; Maloszewski, P.

    2009-09-01

    SummaryIn this paper, five model approaches with different physical and mathematical concepts varying in their model complexity and requirements were applied to identify the transport processes in the unsaturated zone. The applicability of these model approaches were compared and evaluated investigating two tracer breakthrough curves (bromide, deuterium) in a cropped, free-draining lysimeter experiment under natural atmospheric boundary conditions. The data set consisted of time series of water balance, depth resolved water contents, pressure heads and resident concentrations measured during 800 days. The tracer transport parameters were determined using a simple stochastic (stream tube model), three lumped parameter (constant water content model, multi-flow dispersion model, variable flow dispersion model) and a transient model approach. All of them were able to fit the tracer breakthrough curves. The identified transport parameters of each model approach were compared. Despite the differing physical and mathematical concepts the resulting parameters (mean water contents, mean water flux, dispersivities) of the five model approaches were all in the same range. The results indicate that the flow processes are also describable assuming steady state conditions. Homogeneous matrix flow is dominant and a small pore volume with enhanced flow velocities near saturation was identified with variable saturation flow and transport approach. The multi-flow dispersion model also identified preferential flow and additionally suggested a third less mobile flow component. Due to high fitting accuracy and parameter similarity all model approaches indicated reliable results.

  1. Microbial Metabolism and Inhibition Studies of Phenobarbital ...

    African Journals Online (AJOL)

    Purpose: Screening scale studies were performed with eight cultures for their ability to metabolize phenobarbital, an antiepileptic, sedative, hypnotic and substrate for CYP 2C9 and 2C19. Methods: The transformation of phenobarbital was confirmed and characterized by fermentation techniques, high performance liquid ...

  2. Microbial Metabolism and Inhibition Studies of Phenobarbital

    African Journals Online (AJOL)

    Erah

    techniques, high performance liquid chromatography (HPLC), mass spectrometry (MS) ... Keywords: Microbial metabolism, Phenobarbital, Inhibition studies, Rhizopus stolonifer, CYP 2C9, .... 24 h of incubation 0.5 ml of drug solution was ... mode, positive: spray voltage, 3.5 KV: ... Rhizopus stolonifer showed an extra peak at.

  3. A radiogenic isotope tracer study of transatlantic dust transport from Africa to the Caribbean

    Science.gov (United States)

    Kumar, A.; Abouchami, W.; Galer, S.J.G.; Garrison, V.H.; Williams, E.; Andreae, M.O.

    2014-01-01

    Many studies have suggested that long-range transport of African desert dusts across the Atlantic Ocean occurs, delivering key nutrients and contributing to fertilization of the Amazon rainforest. Here we utilize radiogenic isotope tracers – Sr, Nd and Pb – to derive the provenance, local or remote, and pathways of dust transport from Africa to the Caribbean. Atmospheric total suspended particulate (TSP) matter was collected in 2008 on quartz fibre filters, from both sides of the Atlantic Ocean at three different locations: in Mali (12.6°N, 8.0°W; 555 m a.s.l.), Tobago (11.3°N, 60.5°W; 329 m a.s.l.) and the U.S. Virgin Islands (17.7°N, 64.6°W; 27 m a.s.l.). Both the labile phase, representative of the anthropogenic signal, and the refractory detrital silicate fraction were analysed. Dust deposits and soils from around the sampling sites were measured as well to assess the potential contribution from local sources to the mineral dust collected. The contribution from anthropogenic sources of Pb was predominant in the labile, leachate phase. The overall similarity in Pb isotope signatures found in the leachates is attributed to a common African source of anthropogenic Pb, with minor inputs from other sources, such as from Central and South America. The Pb, Sr and Nd isotopic compositions in the silicate fraction were found to be systematically more radiogenic than those in the corresponding labile phases. In contrast, Nd and Sr isotopic compositions from Mali, Tobago, and the Virgin Islands are virtually identical in both leachates and residues. Comparison with existing literature data on Saharan and Sahelian sources constrains the origin of summer dust transported to the Caribbean to mainly originate from the Sahel region, with some contribution from northern Saharan sources. The source regions derived from the isotope data are consistent with 7-day back-trajectory analyses, demonstrating the usefulness of radiogenic isotopes in tracing dust provenance and

  4. A radiogenic isotope tracer study of transatlantic dust transport from Africa to the Caribbean

    Science.gov (United States)

    Kumar, A.; Abouchami, W.; Galer, S. J. G.; Garrison, V. H.; Williams, E.; Andreae, M. O.

    2014-01-01

    Many studies have suggested that long-range transport of African desert dusts across the Atlantic Ocean occurs, delivering key nutrients and contributing to fertilization of the Amazon rainforest. Here we utilize radiogenic isotope tracers - Sr, Nd and Pb - to derive the provenance, local or remote, and pathways of dust transport from Africa to the Caribbean. Atmospheric total suspended particulate (TSP) matter was collected in 2008 on quartz fibre filters, from both sides of the Atlantic Ocean at three different locations: in Mali (12.6°N, 8.0°W; 555 m a.s.l.), Tobago (11.3°N, 60.5°W; 329 m a.s.l.) and the U.S. Virgin Islands (17.7°N, 64.6°W; 27 m a.s.l.). Both the labile phase, representative of the anthropogenic signal, and the refractory detrital silicate fraction were analysed. Dust deposits and soils from around the sampling sites were measured as well to assess the potential contribution from local sources to the mineral dust collected. The contribution from anthropogenic sources of Pb was predominant in the labile, leachate phase. The overall similarity in Pb isotope signatures found in the leachates is attributed to a common African source of anthropogenic Pb, with minor inputs from other sources, such as from Central and South America. The Pb, Sr and Nd isotopic compositions in the silicate fraction were found to be systematically more radiogenic than those in the corresponding labile phases. In contrast, Nd and Sr isotopic compositions from Mali, Tobago, and the Virgin Islands are virtually identical in both leachates and residues. Comparison with existing literature data on Saharan and Sahelian sources constrains the origin of summer dust transported to the Caribbean to mainly originate from the Sahel region, with some contribution from northern Saharan sources. The source regions derived from the isotope data are consistent with 7-day back-trajectory analyses, demonstrating the usefulness of radiogenic isotopes in tracing dust provenance and

  5. A Metabolic Study of Huntington's Disease.

    Directory of Open Access Journals (Sweden)

    Rajasree Nambron

    Full Text Available Huntington's disease patients have a number of peripheral manifestations suggestive of metabolic and endocrine abnormalities. We, therefore, investigated a number of metabolic factors in a 24-hour study of Huntington's disease gene carriers (premanifest and moderate stage II/III and controls.Control (n = 15, premanifest (n = 14 and stage II/III (n = 13 participants were studied with blood sampling over a 24-hour period. A battery of clinical tests including neurological rating and function scales were performed. Visceral and subcutaneous adipose distribution was measured using magnetic resonance imaging. We quantified fasting baseline concentrations of glucose, insulin, cholesterol, triglycerides, lipoprotein (a, fatty acids, amino acids, lactate and osteokines. Leptin and ghrelin were quantified in fasting samples and after a standardised meal. We assessed glucose, insulin, growth hormone and cortisol concentrations during a prolonged oral glucose tolerance test.We found no highly significant differences in carbohydrate, protein or lipid metabolism markers between healthy controls, premanifest and stage II/III Huntington's disease subjects. For some markers (osteoprotegerin, tyrosine, lysine, phenylalanine and arginine there is a suggestion (p values between 0.02 and 0.05 that levels are higher in patients with premanifest HD, but not moderate HD. However, given the large number of statistical tests performed interpretation of these findings must be cautious.Contrary to previous studies that showed altered levels of metabolic markers in patients with Huntington's disease, our study did not demonstrate convincing evidence of abnormalities in any of the markers examined. Our analyses were restricted to Huntington's disease patients not taking neuroleptics, anti-depressants or other medication affecting metabolic pathways. Even with the modest sample sizes studied, the lack of highly significant results, despite many being tested, suggests that

  6. 2007 California Aerosol Study: Evaluation of δ15N as a Tracer Of NOx Sources and Chemsitry

    Science.gov (United States)

    Katzman, T. L.

    2017-12-01

    Although stable isotopes of N are commonly used as a source tracer, how this tracer is applied is a point of contention. The "source" hypothesis argues that the δ15N value of NO3- reflects the δ15N value of NOx source inputs into the environment, and any observed variation is solely the result of differences in source contributions. Conversely, the "chemistry" hypothesis argues that N isotopes are influenced by chemical reactions, atmospheric or biologic processing, and post-depositional effects. Previous studies often apply the source hypothesis, writing off the chemistry hypothesis as "minor," but others have noted the impact chemistry should has on δ15N values. Given the known complications, this work seeks to assess the use of stable isotopes as tracers, specifically, the assumption that the δ15N value is a tracer of source alone without significant influence from chemical reactions. If the "source" hypothesis is correct, source emission data, known source δ15N values, and isotope mass balance should be able to approximate measured δ15NNO3 values and determine the δ15N value associated with wildfire derived NOx, which is currently unknown. Significant deviations from observed values would support the significance of equilibrium and kinetic isotope effects associated with chemical reactions and processing in the atmosphere. Aerosols collected in during 2007, emission data, and isotopic analysis were utilized to determine the utility of δ15N as tracer of NOx sources. San Diego, California is a coastal urban area influenced by sea salt aerosols, anthropogenic combustion emissions, and seasonal wildfires. Wildfires also have a significant influence on local atmospheric chemistry and 2007 was notable for being one of the worst fire seasons in the San Diego region on record. Isotopic analysis of collected NO3- has suggested that source δ15N values are likely not conserved as NOx is oxidized into NO3-. Given known source contributions and known δ15N values

  7. Isotope pattern deconvolution as a tool to study iron metabolism in plants.

    Science.gov (United States)

    Rodríguez-Castrillón, José Angel; Moldovan, Mariella; García Alonso, J Ignacio; Lucena, Juan José; García-Tomé, Maria Luisa; Hernández-Apaolaza, Lourdes

    2008-01-01

    Isotope pattern deconvolution is a mathematical technique for isolating distinct isotope signatures from mixtures of natural abundance and enriched tracers. In iron metabolism studies measurement of all four isotopes of the element by high-resolution multicollector or collision cell ICP-MS allows the determination of the tracer/tracee ratio with simultaneous internal mass bias correction and lower uncertainties. This technique was applied here for the first time to study iron uptake by cucumber plants using 57Fe-enriched iron chelates of the o,o and o,p isomers of ethylenediaminedi(o-hydroxyphenylacetic) acid (EDDHA) and ethylenediamine tetraacetic acid (EDTA). Samples of root, stem, leaves, and xylem sap, after exposure of the cucumber plants to the mentioned 57Fe chelates, were collected, dried, and digested using nitric acid. The isotopic composition of iron in the samples was measured by ICP-MS using a high-resolution multicollector instrument. Mass bias correction was computed using both a natural abundance iron standard and by internal correction using isotope pattern deconvolution. It was observed that, for plants with low 57Fe enrichment, isotope pattern deconvolution provided lower tracer/tracee ratio uncertainties than the traditional method applying external mass bias correction. The total amount of the element in the plants was determined by isotope dilution analysis, using a collision cell quadrupole ICP-MS instrument, after addition of 57Fe or natural abundance Fe in a known amount which depended on the isotopic composition of the sample.

  8. Isotope pattern deconvolution as a tool to study iron metabolism in plants

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Castrillon, Jose A.; Moldovan, Mariella; Garcia Alonso, J.I. [University of Oviedo, Department of Physical and Analytical Chemistry, Oviedo (Spain); Lucena, Juan J.; Garcia-Tome, Maria L.; Hernandez-Apaolaza, Lourdes [Autonoma University of Madrid, Department of Agricultural Chemistry, Madrid (Spain)

    2008-01-15

    Isotope pattern deconvolution is a mathematical technique for isolating distinct isotope signatures from mixtures of natural abundance and enriched tracers. In iron metabolism studies measurement of all four isotopes of the element by high-resolution multicollector or collision cell ICP-MS allows the determination of the tracer/tracee ratio with simultaneous internal mass bias correction and lower uncertainties. This technique was applied here for the first time to study iron uptake by cucumber plants using {sup 57}Fe-enriched iron chelates of the o,o and o,p isomers of ethylenediaminedi(o-hydroxyphenylacetic) acid (EDDHA) and ethylenediamine tetraacetic acid (EDTA). Samples of root, stem, leaves, and xylem sap, after exposure of the cucumber plants to the mentioned {sup 57}Fe chelates, were collected, dried, and digested using nitric acid. The isotopic composition of iron in the samples was measured by ICP-MS using a high-resolution multicollector instrument. Mass bias correction was computed using both a natural abundance iron standard and by internal correction using isotope pattern deconvolution. It was observed that, for plants with low {sup 57}Fe enrichment, isotope pattern deconvolution provided lower tracer/tracee ratio uncertainties than the traditional method applying external mass bias correction. The total amount of the element in the plants was determined by isotope dilution analysis, using a collision cell quadrupole ICP-MS instrument, after addition of {sup 57}Fe or natural abundance Fe in a known amount which depended on the isotopic composition of the sample. (orig.)

  9. Whole-body biodistribution, dosimetry and metabolite correction of [11C]palmitate: A PET tracer for imaging of fatty acid metabolism

    DEFF Research Database (Denmark)

    Christensen, Nana Louise; Jakobsen, Steen; Schacht, Anna Christina

    2017-01-01

    INTRODUCTION: Despite the decades long use of [11C]palmitate positron emission tomography (PET)/computed tomography in basic metabolism studies, only personal communications regarding dosimetry and biodistribution data have been published. METHODS: Dosimetry and biodistribution studies were...... performed in 2 pigs and 2 healthy volunteers by whole-body [11C]palmitate PET scans. Metabolite studies were performed in 40 participants (healthy and with type 2 diabetes) under basal and hyperinsulinemic conditions. Metabolites were estimated using 2 approaches and subsequently compared: Indirect [11C]CO2...

  10. Application of accelerator mass spectrometry in aluminum metabolism studies

    International Nuclear Information System (INIS)

    Meirav, O.; Vetterli, D.; Johnson, R.R.; Sutton, R.A.L.; Walker, V.R.; Halabe, A.; Fink, D.; Middleton, R.; Klein, J.

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic patients and may be associated with Alzheimer's disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope 26 Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as humans. (Author) (24 refs., 3 figs.)

  11. Application of accelerator mass spectrometry in aluminum metabolism studies

    Energy Technology Data Exchange (ETDEWEB)

    Meirav, O; Vetterli, D; Johnson, R R [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Sutton, R A.L.; Walker, V R; Halabe, A [British Columbia U.iv., Vancouver, BC (Canada). Dept. of Medicine; Fink, D; Middleton, R; Klein, J [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Physics

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic patients and may be associated with Alzheimer`s disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope {sup 26}Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as humans. (Author) (24 refs., 3 figs.).

  12. Collection and processing of information in biological kinetics studies with radioactive tracers

    International Nuclear Information System (INIS)

    Remy, J.; Lafuma, J.

    1968-01-01

    The authors present an automatic method for the collection and treatment of information in biological kinetics experiments using radioactive tracers. The recording are made without any time constant on magnetic tape. The information recorded is sampled by a 400 channel multi-scale analyzer and transferred to punched cards. The digital analysis is done by an I.B.M. computer. The method is illustrated by an example: the hepatic fixation of colloidal gold in the pig. Its advantages and requirements are discussed. In the appendix are given the FORTRAN texts for two programmes used in treating the example presented. (authors) [fr

  13. Study of solid phase kinetics during cyanidation using the 198 Au radioactive tracer

    International Nuclear Information System (INIS)

    Barbus, A.; Pop, I.I.; Gaspar, E.

    1995-01-01

    During cyanidation, the various gold bearing pyrite sorts exhibit different behaviour, that sometimes cause increased cyanidation times influencing the reagent and power consumption, in the same time generating fluctuations in the recovery efficiencies. The introduction of the 198 Au radioactive tracer into the cyanidation circuit enabled us to follow several parameters of the cyanidation kinetics: the average residence time of the gold bearing pyrite in the technological equipment, information about the homogenization process, dispersion of solids and gold dissolution efficiency on each technological stage. (author)

  14. Metabolic cartography: experimental quantification of metabolic fluxes from isotopic labelling studies.

    Science.gov (United States)

    O'Grady, John; Schwender, Jörg; Shachar-Hill, Yair; Morgan, John A

    2012-03-01

    For the past decade, flux maps have provided researchers with an in-depth perspective on plant metabolism. As a rapidly developing field, significant headway has been made recently in computation, experimentation, and overall understanding of metabolic flux analysis. These advances are particularly applicable to the study of plant metabolism. New dynamic computational methods such as non-stationary metabolic flux analysis are finding their place in the toolbox of metabolic engineering, allowing more organisms to be studied and decreasing the time necessary for experimentation, thereby opening new avenues by which to explore the vast diversity of plant metabolism. Also, improved methods of metabolite detection and measurement have been developed, enabling increasingly greater resolution of flux measurements and the analysis of a greater number of the multitude of plant metabolic pathways. Methods to deconvolute organelle-specific metabolism are employed with increasing effectiveness, elucidating the compartmental specificity inherent in plant metabolism. Advances in metabolite measurements have also enabled new types of experiments, such as the calculation of metabolic fluxes based on (13)CO(2) dynamic labelling data, and will continue to direct plant metabolic engineering. Newly calculated metabolic flux maps reveal surprising and useful information about plant metabolism, guiding future genetic engineering of crops to higher yields. Due to the significant level of complexity in plants, these methods in combination with other systems biology measurements are necessary to guide plant metabolic engineering in the future.

  15. Tracer research in process engineering

    International Nuclear Information System (INIS)

    Iller, E.

    1992-01-01

    The book is a review of modern applications of tracer techniques in chemical and process engineering studies. The next topics have been extensively presented: 1) media flow through apparatus; 2) the tracers in the study of media flow dynamics through apparatus; 3) mathematical interpretation of experimental data from impulse-response method; 4) the models of media flow through chemical reactors and apparatus; 5) radiotracers in mass transport study; 6) examples of practical applications of tracer methods in industrial objects. 84 refs, 96 figs, 31 tabs

  16. Assessment of myocardial metabolic flexibility and work efficiency in human type 2 diabetes using 16-[18F]fluoro-4-thiapalmitate, a novel PET fatty acid tracer.

    Science.gov (United States)

    Mather, K J; Hutchins, G D; Perry, K; Territo, W; Chisholm, R; Acton, A; Glick-Wilson, B; Considine, R V; Moberly, S; DeGrado, T R

    2016-03-15

    Altered myocardial fuel selection likely underlies cardiac disease risk in diabetes, affecting oxygen demand and myocardial metabolic flexibility. We investigated myocardial fuel selection and metabolic flexibility in human type 2 diabetes mellitus (T2DM), using positron emission tomography to measure rates of myocardial fatty acid oxidation {16-[(18)F]fluoro-4-thia-palmitate (FTP)} and myocardial perfusion and total oxidation ([(11)C]acetate). Participants underwent paired studies under fasting conditions, comparing 3-h insulin + glucose euglycemic clamp conditions (120 mU·m(-2)·min(-1)) to 3-h saline infusion. Lean controls (n = 10) were compared with glycemically controlled volunteers with T2DM (n = 8). Insulin augmented heart rate, blood pressure, and stroke index in both groups (all P work efficiency was lower in T2DM (P = 0.006) and decreased in both groups with the insulin-induced increase in work and shift in fuel utilization (P = 0.01). Augmented fatty acid oxidation is present under baseline and insulin-treated conditions in T2DM, with impaired insulin-induced shifts away from fatty acid oxidation. This is accompanied by reduced work efficiency, possibly due to greater oxygen consumption with fatty acid metabolism. These observations suggest that improved fatty acid suppression, or reductions in myocardial fatty acid uptake and retention, could be therapeutic targets to improve myocardial ischemia tolerance in T2DM. Copyright © 2016 the American Physiological Society.

  17. Kajian Profil Lulusan STAIN Samarinda Program Studi Pendidikan Agama Islam (PAI Tahun 2009 – 2013 dengan Pendekatan Tracer Study

    Directory of Open Access Journals (Sweden)

    Wahdatunnisa Wahdatunnisa

    2014-06-01

    Full Text Available Islamic higher education is targeted to create a high qualified human resources. A tracer study could be used to gain a data about the flaws, both of the process of education and the process of learning, of the quality of Islamic higher educations. by knowing the flaws, it can be used to make a better planning in the future. The problem of this study are: 1 How is the appropriateness of the work-field of the alumnae and the study program of Islamic education program of IAIN Samarinda?, 2 How is the contributions of the curriculum of Islamic education program of IAIN Samarinda to the work-field?, 3 How is the improvement of curriculum of Islamic education program of IAIN Samarinda to create a high qualified alumnae? This is and evaluative research design which is objected to describe the profil of alumnae and the curriculum relevance at Islamic education program at IAIN Samarinda. In this study, the researcher used interview and documentation to collect the data. The researcher used interview guide and recording tools as the instruments. The result of the study shows that: firstly, most of alumnae work in the schools as teachers or administration staff. Secondly, curriculum of PAI at STAIN Samarinda proves in supporting the work of alumnae. Thirdly, the improvement of curriculum can be done by adjusting the content of curriculum with the work field, improving lecturers’ qualification, erlarging the practicum, empowering the alumnae with some competencies, and strengthening the subjects of teachers and educational content.

  18. Whole-body biodistribution, dosimetry and metabolite correction of [11C]palmitate: A PET tracer for imaging of fatty acid metabolism

    DEFF Research Database (Denmark)

    Christensen, Nana Louise; Jakobsen, Steen; Schacht, Anna Christina

    2017-01-01

    release and parent [11C]palmitate measured by a solid-phase extraction (SPE) method. Finally, myocardial fatty acid uptake was calculated in a patient cohort using input functions derived from individual metabolite correction compared with population-based metabolite correction. RESULTS: In humans, mean......INTRODUCTION: Despite the decades long use of [11C]palmitate positron emission tomography (PET)/computed tomography in basic metabolism studies, only personal communications regarding dosimetry and biodistribution data have been published. METHODS: Dosimetry and biodistribution studies were...

  19. Study on lead transportation in air-water-paddy system with 210Pb as tracer

    International Nuclear Information System (INIS)

    Li Shuding; Zhang Hairong; Ma Xuejun

    1987-08-01

    With 210 PbCl 2 as tracer, a research into lead sources in brown rice, lead distribution in soil and rice, lead chemical forms in soil and their change with time, availability of soil for rice and effect of soil pH on the Pb adsorption was carried out in air-water-paddy system near cities and towns located upper and middle reaches of Liaohe River, northeastern China. Test soil was light acid meadow brown soil. The Pb proportions in rice grain derived from the soil, airborne dust and irrigation water and the transportation pathway to brown rice were investigated. Transportation coefficients of Pb in the system were determined by tracer experiment. It was indicated that the Pb concentration in rice root, the Pb concentration and its distribution in the soil are main factors effecting Pb transportation to rice. Based on the simulation test, mathematical model for computing soil environmental capacity of Pb in the system is put forward. The soil environmental capacity of Pb computed is 1600 - 1700 ppm, i.e. 3.6 - 3.8 t/ha. The computed result was in agreement with the observed. The mathematical model was also used to compute soil enviromental capacity of those heavy metal corresponding respectively with 203 Hg, 115+115m Cd, 65 Zn, 51 Cr, 65 Ni, 60 Co etc

  20. Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

    Science.gov (United States)

    Paul, J H; Rose, J B; Brown, J; Shinn, E A; Miller, S; Farrah, S R

    1995-06-01

    Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

  1. 18O isotopic tracer studies of silicon oxidation in dry oxygen

    International Nuclear Information System (INIS)

    Han, C.J.

    1986-01-01

    Oxidation of silicon in dry oxygen has been an important process in the integrated circuit industry for making gate insulators on metal-oxide-semiconductory (MOS) devices. This work examines this process using isotopic tracers of oxygen to determine the transport mechanisms of oxygen through silicon dioxide. Oxides were grown sequentially using mass-16 and mass-18 oxygen gas sources to label the oxygen molecules from each step. The resulting oxides are analyzed using secondary ion mass spectrometry (SIMS). The results of these analyses suggest two oxidant species are present during the oxidation, each diffuses and oxidizes separately during the process. A model from this finding using a sum of two linear-parabolic growth rates, each representing the growth rate from one of the oxidants, describes the reported oxidation kinetics in the literature closely. A fit of this relationship reveals excellent fits to the data for oxide thicknesses ranging from 30 A to 1 μm and for temperatures ranging from 800 to 1200 0 C. The mass-18 oxygen tracers also enable a direct observation of the oxygen solubility in the silicon dioxide during a dry oxidation process. The SIMS profiles establish a maximum solubility for interstitial oxygen at 1000 0 C at 2 x 10 20 cm -3 . Furthermore, the mass-18 oxygen profiles show negligible network diffusion during an 1000 0 C oxidation

  2. Studies on the distribution of 2,4 D herbicide in soil-plant ecosystem using isotope tracer techniques

    International Nuclear Information System (INIS)

    Onal, G.

    1986-01-01

    In this study, distribution of 2,4 Diclorophenoxyacetic acid (2,4 D) herbicide in soil-plant ecosystems under greenhouse conditions were investigated by using isotope tracer techniques. For this purpose barley, wheat and oat plants were grown in two different kinds of soil taken from surrounding of Ankara and the distribution of the herbicide between soil and plants were investigated. In the research 14 C-2,40 D was used and the radioactivity was measured in a liquid scintillation counter. (author)

  3. Study on bioavailability of dietary iron of women by using activable isotopic tracer and neutron activation analysis techniques

    International Nuclear Information System (INIS)

    Zhang Yangmei; Ni Bangfa; Tian Weizhi; Wang Pingsheng; Cao Lei

    2002-01-01

    The bioavailability of diet iron of 10 healthy young women in Beijing area is studied by using two enriched isotopes 54 Fe and 58 Fe, and neutron activation analysis techniques. The abundance of 54 Fe and 58 Fe is 61.4% and 23.4%, respectively. In additional, the atomic absorption spectrometry is employed to measure total iron in fecal samples. Dysprosium, rarely absorbed by human body, is used to monitor the residence time of tracer isotopes in order to collect the fecal samples completely. The results show that the bioavailability of dietary iron in young women is (14.9 +- 3.9)%

  4. Reactivity of hydrogen contained in Raney nickel for ethylene hydrogenation studied by means of a tritium tracer

    International Nuclear Information System (INIS)

    Miyatani, Daisaku; Takeuchi, Toyosaburo.

    1979-01-01

    Reactivity of hydrogen contained in Raney nickel with ethylene was studied by using a tritium tracer. Hydrogen in Raney nickel was previously labeled with tritium and distinguished from hydrogen introduced during the hydrogenation reaction. The reactivity of the contained hydrogen was determined by measurement of the radioactivity of ethane produced in the hydrogenation. Ethylene reacted with hydrogen in Raney nickel for no supply of hydrogen during the hydrogenation. However, when ethylene was hydrogenated by both hydrogen in Raney nickel and introduced hydrogen, over 99% of the ethylene reacted with the introduced hydrogen and hardly reacted with the contained hydrogen. (author)

  5. Kinetic and Related Determinants of Plasma Triglyceride Concentration in Abdominal Obesity: Multicenter Tracer Kinetic Study.

    Science.gov (United States)

    Borén, Jan; Watts, Gerald F; Adiels, Martin; Söderlund, Sanni; Chan, Dick C; Hakkarainen, Antti; Lundbom, Nina; Matikainen, Niina; Kahri, Juhani; Vergès, Bruno; Barrett, P Hugh R; Taskinen, Marja-Riitta

    2015-10-01

    Patients with obesity and diabetes mellitus have increased risk of cardiovascular disease. A major cause is an atherogenic dyslipidemia related primarily to elevated plasma concentrations of triglyceride-rich lipoproteins. The aim of this study was to clarify determinants of plasma triglyceride concentration. We focused on factors that predict the kinetics of very-low density lipoprotein 1 (VLDL1) triglycerides. A multicenter study using dual stable isotopes (deuterated leucine and glycerol) and multicompartmental modeling was performed to elucidate the kinetics of triglycerides and apoB in VLDL1 in 46 subjects with abdominal obesity and additional cardiometabolic risk factors. Results showed that plasma triglyceride concentrations were dependent on both the secretion rate (r=0.44, Ptriglycerides and VLDL1-apoB. Liver fat mass was independently and directly associated with secretion rates of VLDL1-triglycerides (r=0.56, Ptriglycerides (r=0.48, Ptriglyceride concentrations in abdominal obesity are determined by the kinetics of VLDL1 subspecies, catabolism being mainly dependent on apoC-III concentration and secretion on liver fat content. Reduction in liver fat and targeting apoC-III may be an effective approach for correcting triglyceride metabolism atherogenic dyslipidemia in obesity. © 2015 American Heart Association, Inc.

  6. Particle integrity, sampling, and application of a DNA-tagged tracer for aerosol transport studies

    Energy Technology Data Exchange (ETDEWEB)

    Kaeser, Cynthia Jeanne [Michigan State Univ., East Lansing, MI (United States)

    2017-07-21

    Aerosols are an ever-present part of our daily environment and have extensive effects on both human and environmental health. Particles in the inhalable range (1-10 μm diameter) are of particular concern because their deposition in the lung can lead to a variety of illnesses including allergic reactions, viral or bacterial infections, and cancer. Understanding the transport of inhalable aerosols across both short and long distances is necessary to predict human exposures to aerosols. To assess the transport of hazardous aerosols, surrogate tracer particles are required to measure their transport through occupied spaces. These tracer particles must not only possess similar transport characteristics to those of interest but also be easily distinguished from the background at low levels and survive the environmental conditions of the testing environment. A previously-developed DNA-tagged particle (DNATrax), composed of food-grade sugar and a DNA oligonucleotide as a “barcode” label, shows promise as a new aerosol tracer. Herein, the use of DNATrax material is validated for use in both indoor and outdoor environments. Utilizing passive samplers made of materials commonly found in indoor environments followed by quantitative polymerase chain reaction (qPCR) assay for endpoint particle detection, particles detection was achieved up to 90 m from the aerosolization location and across shorter distances with high spatial resolution. The unique DNA label and PCR assay specificity were leveraged to perform multiple simultaneous experiments. This allowed the assessment of experimental reproducibility, a rare occurrence among aerosol field tests. To transition to outdoor testing, the solid material provides some protection of the DNA label when exposed to ultraviolet (UV) radiation, with 60% of the DNA remaining intact after 60 minutes under a germicidal lamp and the rate of degradation declining with irradiation time. Additionally, exposure of the DNATrax material using

  7. Tracer dating and ocean ventilation

    International Nuclear Information System (INIS)

    Thiele, G.; Sarmiento, J.L.

    1990-01-01

    The interpretation of transient tracer observations depends on difficult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. The authors use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. The authors define an idealized ventilation age tracer that is conservative with respect to mixing, and they explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters

  8. Meteorological tracers in regional planning

    International Nuclear Information System (INIS)

    Mueller, K.H.

    1974-11-01

    Atmospheric tracers can be used as indicators to study both the ventilation of an urban region and its dispersion meteorology for air pollutants. A correlation analysis applied to the space-time dependent tracer concentrations is able to give transfer functions, the structure and characteristic parameters of which describe the meteorological and topographical situation of the urban region and its surroundings in an integral manner. To reduce the number of persons usually involved in a tracer experiment an automatic air sampling system had to be developed

  9. Validation of [1-11C]acetate as a tracer for noninvasive assessment of oxidative metabolism with positron emission tomography in normal, ischemic, postischemic, and hyperemic canine myocardium

    International Nuclear Information System (INIS)

    Armbrecht, J.J.; Buxton, D.B.; Schelbert, H.R.

    1990-01-01

    Extraction and clearance kinetics of [1-11C]acetate were examined in 65 experiments in 30 open-chest dogs. Twenty-nine studies were performed at control, 13 during ischemia, eight after reperfusion, 13 during dipyridamole-induced hyperemia, and two during alteration of cardiac workload. [1-11C]acetate was injected directly into the left anterior descending coronary artery, and myocardial tissue-time activity curves were recorded with a gamma probe. The single-pass extraction fraction averaged 64.2 +/- 9.7% in control, 65.3 +/- 9.1% in ischemia, 70.0 +/- 4.4% in reperfusion, and 46.5 +/- 7.4% in dipyridamole-induced hyperemia groups. 11C clearance was biexponential in all cases. The rate constant k1 for the first rapid clearance phase correlated closely with myocardial oxygen consumption (r = 0.94) in control, ischemia, reperfusion, and dipyridamole-induced hyperemia groups. Monoexponential fitting of only the first linear part of the clearance curve yielded the rate constant kmono, which also correlated with myocardial oxygen consumption (r = 0.96). Arterial lactate concentrations and the amount of free fatty acid oxygen equivalents consumed by the myocardium were shown to have a small but statistically significant impact on the relation between [1-11C]acetate clearance rate constants and myocardial oxygen consumption. The fraction of 14CO2 activity contributing to overall 14C activity leaving the myocardium after simultaneous injection of [1-14C]acetate (n = 24) was relatively high in all cases , indicating that externally measured 11C clearance corresponds to CO2 production and thus to tricarboxylic acid cycle activity. In conclusion, the results validate the use of [1-11C]acetate as a tracer of oxidative myocardial metabolism for use with positron emission tomography

  10. Measuring SSRI occupancy of SERT using the novel tracer [{sup 123}I]ADAM: a SPECT validation study

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Kjell; Lui, Dominic; Townsend, Caroline E.; Ell, Peter J. [Middlesex Hospital, Institute of Nuclear Medicine, University College London, London (United Kingdom); Sivananthan, Tharani; Mu, Song; Lucas, Richard [Lilly Research Centre, Eli Lilly and Company, Windlesham, Surrey (United Kingdom); Spezzi, Andrea; Warrington, Steven [Central Middlesex Hospital, Hammersmith Medicines Research, London (United Kingdom)

    2005-11-01

    Serotonergic brain regions play a crucial role in the modulation of emotion, and serotonergic dysfunction may contribute to several neurological disorders. [{sup 123}I]ADAM is a novel SPECT tracer which binds with high affinity to serotonin transporters (SERT). The objective of this study was to compare different methods for the quantification of tracer binding and to develop a simplified single-scan protocol for this tracer, as well as to investigate its potential for characterisation of the transporter occupancy versus plasma concentration curve of a selective serotonin re-uptake inhibitor (SSRI). Dynamic SPECT scans were performed on 16 healthy volunteers after administration of {proportional_to}150 MBq [{sup 123}I]ADAM. Data were acquired from the time of injection until {proportional_to}5.5 h after injection in 30- or 45-min sessions. Each subject was scanned twice: with and without pre-treatment with the SSRI citalopram in various dosage regimens. The plasma concentration of citalopram (C{sub p}) was determined from venous samples. Images were reconstructed by filtered back-projection with scatter and attenuation correction. Tracer binding was quantified for midbrain, striatum and thalamus using cerebellum as a reference region. Quantification was done by kinetic modelling, graphical analysis and multi-linear regression, as well as by the ratio method, with binding potential (BP{sub 2}) as the outcome measure. The SERT occupancy by citalopram was determined relative to the baseline scan for each subject, and the occupancy versus C{sub p} curve was fitted with the E{sub max} model. The highest binding of [{sup 123}I]ADAM was in midbrain (mean baseline BP{sub 2}{+-}SD=1.31{+-}0.29), with lower binding in thalamus (0.79{+-}0.16) and striatum (0.66{+-}0.13). There was good agreement between BP{sub 2} values obtained by different quantification methods. Using the ratio method, the best agreement with kinetic modelling was obtained with data from the time interval

  11. Measuring SSRI occupancy of SERT using the novel tracer [123I]ADAM: a SPECT validation study

    International Nuclear Information System (INIS)

    Erlandsson, Kjell; Lui, Dominic; Townsend, Caroline E.; Ell, Peter J.; Sivananthan, Tharani; Mu, Song; Lucas, Richard; Spezzi, Andrea; Warrington, Steven

    2005-01-01

    Serotonergic brain regions play a crucial role in the modulation of emotion, and serotonergic dysfunction may contribute to several neurological disorders. [ 123 I]ADAM is a novel SPECT tracer which binds with high affinity to serotonin transporters (SERT). The objective of this study was to compare different methods for the quantification of tracer binding and to develop a simplified single-scan protocol for this tracer, as well as to investigate its potential for characterisation of the transporter occupancy versus plasma concentration curve of a selective serotonin re-uptake inhibitor (SSRI). Dynamic SPECT scans were performed on 16 healthy volunteers after administration of ∝150 MBq [ 123 I]ADAM. Data were acquired from the time of injection until ∝5.5 h after injection in 30- or 45-min sessions. Each subject was scanned twice: with and without pre-treatment with the SSRI citalopram in various dosage regimens. The plasma concentration of citalopram (C p ) was determined from venous samples. Images were reconstructed by filtered back-projection with scatter and attenuation correction. Tracer binding was quantified for midbrain, striatum and thalamus using cerebellum as a reference region. Quantification was done by kinetic modelling, graphical analysis and multi-linear regression, as well as by the ratio method, with binding potential (BP 2 ) as the outcome measure. The SERT occupancy by citalopram was determined relative to the baseline scan for each subject, and the occupancy versus C p curve was fitted with the E max model. The highest binding of [ 123 I]ADAM was in midbrain (mean baseline BP 2 ±SD=1.31±0.29), with lower binding in thalamus (0.79±0.16) and striatum (0.66±0.13). There was good agreement between BP 2 values obtained by different quantification methods. Using the ratio method, the best agreement with kinetic modelling was obtained with data from the time interval [200,260] min after injection. The fitting of the midbrain occupancy curve

  12. Cobalt and tantalum tracers measured by activation analysis in sediment transport studies

    Energy Technology Data Exchange (ETDEWEB)

    Groot, A.J. de [Institute for Soil Fertility, Haren (Netherlands); Allersma, E [Delft Hydraulics Laboratory, Delft (Netherlands); Bruin, M de; Houtman, J P.W. [Reactor Institute, Delft (Netherlands)

    1970-09-15

    The paper proposes certain principles of research to be used in investigating the origin and transport of fine-grained sediments in rivers and sea arms in connection with siltation problems of harbours and navigation channels. An element, which either does not occur in the sediment or only occurs in minute quantities, is fixed to the mud from the river or sea arm. After the material is marked it is returned to the water course where it mixes with the solids moving naturally. At specified points throughout the water course sediment samples are taken to determine the marking element by activation analysis. This gives an insight into the flow path of the suspended matter. The selection and successful application of tracers that can be measured by activation analysis depends on the sensitivity of detection, the natural occurrence of the relevant elements in the sediments under investigation and the fixation capacity of the tracer to the various grain size fractions. Further, the influence of the added element on the sedimentation behaviour of the mud in suspension and on the desorption properties must be considered. The irradiation of Co and Ta with thermal neutrons gives rise to a very sensitive evaluation of the original elements present. The fixation process of Co is restricted to sediments with special characteristics; Ta, however, can adhere tightly to any sediment. Tantalum also has the advantage that its natural content in sediments is very low. Large quantities (several per cent by weight) can adhere to the sediment without changing the sedimentation properties to an appreciable extent. Hardly any losses occur during leaching experiments simulating natural conditions. A detailed treatment is given of the chemical aspects of the method, including the behaviour of the elements used in the light of the general environmental processes of sediment constituents in deltaic systems. Finally, the scope and limits of the method are discussed. (author)

  13. Cobalt and Tantalum Tracers Measured by Activation Analysis in Sediment Transport Studies

    Energy Technology Data Exchange (ETDEWEB)

    Groot, A.J. de [Institute for Soil Fertility, Haren (Netherlands); Allersma, E. [Delft Hydraulics Laboratory, Delft (Netherlands); Bruin, M. de; Houtman, J. P.W. [Reactor Institute, Delft (Netherlands)

    1970-09-15

    The paper proposes certain principles of research to be used in investigating the origin and transport of fine-grained sediments in rivers and sea arms in connection with siltation problems of harbours and navigation channels. An element, which either does not occur in the sediment or only occurs in minute quantities, is fixed to the mud from the river or sea arm. After the material is marked it is returned to the water course where it mixes with the solids moving naturally. At specified points throughout the water course sediment samples are taken to determine the marking element by activation analysis. This gives an insight into the flow path of the suspended matter. The selection and successful application of tracers that can be measured by activation analysis depends on the sensitivity of detection, the natural occurrence of the relevant elements in the sediments under investigation and the fixation capacity of the tracer to the various grain size fractions. Further, the influence of the added element on the sedimentation behaviour of the mud in suspension and on the desorption properties must be considered. The irradiation of Co and Ta with thermal neutrons gives rise to a very sensitive evaluation of the original elements present. The fixation process of Co is restricted to sediments with special characteristics; Ta, however, can adhere tightly to any sediment. Tantalum also has the advantage that its natural content in sediments is very low. Large quantities (several per cent by weight) can adhere to the sediment without changing the sedimentation properties to an appreciable extent. Hardly any losses occur during leaching experiments simulating natural conditions. A detailed treatment is given of the chemical aspects of the method, including the behaviour of the elements used in the light of the general environmental processes of sediment constituents in deltaic systems. Finally, the scope and limits of the method are discussed. (author)

  14. [{sup 18}F]FE rate at SUPPY: a suitable PET tracer for the adenosine A3 receptor? An in vivo study in rodents

    Energy Technology Data Exchange (ETDEWEB)

    Haeusler, Daniela; Zeilinger, Markus; Wadsak, Wolfgang; Hacker, Marcus; Mitterhauser, Markus [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Kuntner, Claudia; Wanek, Thomas; Langer, Oliver [AIT Austrian Institute of Technology GmbH, Biomedical Systems, Health and Environment Department, Seibersdorf (Austria); Nics, Lukas [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); University of Vienna, Department of Nutritional Sciences, Vienna (Austria); Savli, Markus; Lanzenberger, Rupert R. [Medical University of Vienna, Department of Psychiatry and Psychotherapy, Vienna (Austria); Karagiannis, Panagiotis [King' s College London, Cutaneous Medicine and Immunotherapy, St. John' s Institute of Dermatology, Division of Genetics and Molecular Medicine King' s College London School of Medicine, Guy' s Hospital, London (United Kingdom); Shanab, Karem; Spreitzer, Helmut [University of Vienna, Department of Drug and Natural Product Synthesis, Vienna (Austria)

    2015-04-01

    The adenosine A{sub 3} receptor (A3R) is involved in cardiovascular, neurological and tumour-related pathologies and serves as an exceptional pharmaceutical target in the clinical setting. A3R antagonists are considered antiinflammatory, antiallergic and anticancer agents, and to have potential for the treatment of asthma, COPD, glaucoma and stroke. Hence, an appropriate A3R PET tracer would be highly beneficial for the diagnosis and therapy monitoring of these diseases. Therefore, in this preclinical in vivo study we evaluated the potential as a PET tracer of the A3R antagonist [{sup 18}F]FE rate at SUPPY. Rats were injected with [{sup 18}F]FE rate at SUPPY for baseline scans and blocking scans (A3R with MRS1523 or FE rate at SUPPY, P-gp with tariquidar; three animals each). Additionally, metabolism was studied in plasma and brain. In a preliminary experiment in a mouse xenograft model (mice injected with cells expressing the human A3R; three animals), the animals received [{sup 18}F]FE rate at SUPPY and [{sup 18}F]FDG. Dynamic PET imaging was performed (60 min in rats, 90 min in xenografted mice). In vitro stability of [{sup 18}F]FE rate at SUPPY in human and rat plasma was also evaluated. [{sup 18}F]FE rate at SUPPY showed high uptake in fat-rich regions and low uptake in the brain. Pretreatment with MRS1523 led to a decrease in [{sup 18}F]FE rate at SUPPY uptake (p = 0.03), and pretreatment with the P-gp inhibitor tariquidar led to a 1.24-fold increase in [{sup 18}F]FE rate at SUPPY uptake (p = 0.09) in rat brain. There was no significant difference in metabolites in plasma and brain in the treatment groups. However, plasma concentrations of [{sup 18}F]FE rate at SUPPY were reduced to levels similar to those in rat brain after blocking. In contrast to [{sup 18}F]FDG uptake (p = 0.12), the xenograft model showed significantly increased uptake of [{sup 18}F]FE rate at SUPPY in the tissue masses from CHO cells expressing the human A3R (p = 0.03). [{sup 18}F

  15. [18F]FE rate at SUPPY: a suitable PET tracer for the adenosine A3 receptor? An in vivo study in rodents

    International Nuclear Information System (INIS)

    Haeusler, Daniela; Zeilinger, Markus; Wadsak, Wolfgang; Hacker, Marcus; Mitterhauser, Markus; Kuntner, Claudia; Wanek, Thomas; Langer, Oliver; Nics, Lukas; Savli, Markus; Lanzenberger, Rupert R.; Karagiannis, Panagiotis; Shanab, Karem; Spreitzer, Helmut

    2015-01-01

    The adenosine A 3 receptor (A3R) is involved in cardiovascular, neurological and tumour-related pathologies and serves as an exceptional pharmaceutical target in the clinical setting. A3R antagonists are considered antiinflammatory, antiallergic and anticancer agents, and to have potential for the treatment of asthma, COPD, glaucoma and stroke. Hence, an appropriate A3R PET tracer would be highly beneficial for the diagnosis and therapy monitoring of these diseases. Therefore, in this preclinical in vivo study we evaluated the potential as a PET tracer of the A3R antagonist [ 18 F]FE rate at SUPPY. Rats were injected with [ 18 F]FE rate at SUPPY for baseline scans and blocking scans (A3R with MRS1523 or FE rate at SUPPY, P-gp with tariquidar; three animals each). Additionally, metabolism was studied in plasma and brain. In a preliminary experiment in a mouse xenograft model (mice injected with cells expressing the human A3R; three animals), the animals received [ 18 F]FE rate at SUPPY and [ 18 F]FDG. Dynamic PET imaging was performed (60 min in rats, 90 min in xenografted mice). In vitro stability of [ 18 F]FE rate at SUPPY in human and rat plasma was also evaluated. [ 18 F]FE rate at SUPPY showed high uptake in fat-rich regions and low uptake in the brain. Pretreatment with MRS1523 led to a decrease in [ 18 F]FE rate at SUPPY uptake (p = 0.03), and pretreatment with the P-gp inhibitor tariquidar led to a 1.24-fold increase in [ 18 F]FE rate at SUPPY uptake (p = 0.09) in rat brain. There was no significant difference in metabolites in plasma and brain in the treatment groups. However, plasma concentrations of [ 18 F]FE rate at SUPPY were reduced to levels similar to those in rat brain after blocking. In contrast to [ 18 F]FDG uptake (p = 0.12), the xenograft model showed significantly increased uptake of [ 18 F]FE rate at SUPPY in the tissue masses from CHO cells expressing the human A3R (p = 0.03). [ 18 F]FE rate at SUPPY was stable in human plasma. Selective and

  16. Nuclear magnetic resonance studies of metabolic regulation

    International Nuclear Information System (INIS)

    Sillerud, L.O.; Han, C.H.; Whaley, T.W.

    1983-01-01

    Nuclear magnetic resonance (NMR) techniques for the detection of the metabolic transformations of biological compounds labeled with stable isotopes, particularly carbon-13 have been explored. We have studied adipose tissue in the intact rat, the exteriorized epididymal fat pad, and the isolated adipocyte. Triacylglycerol metabolism in adipose tissue is regulated by lipogenic factors (insulin, corticosterone, thyroxine, and growth hormone) and lipolytic factors (glucagon and catecholamines). The synthesis of triglyceride from 5.5 mM glucose was stimulated by about 4-fold by 10 nM insulin. Triglyceride synthesis from glucose in the presence of insulin occurred at a rate of 330 nmol/hr/10 6 cells. Since the NMR signals from free and esterified fatty acids and glycerol are distinct, we could directly measure the rate of hormone-stimulated lipolysis. Epinephrine (10 μM) gave a lipolytic rate of 0.30 μmol/hr/10 6 cells as monitored by free-glycerol appearance in the medium. 13 C NMR provides a superior method for the measurement of triglyceride metabolism since it directly measures the changes in the substrates and products in situ

  17. Physical oceanographic characteristics influencing the dispersion of dissolved tracers released at the sea floor in selected deep ocean study areas

    International Nuclear Information System (INIS)

    Kupferman, S.L.; Moore, D.E.

    1981-02-01

    Scenarios which follow the development in space and time of the concentration field of a dissolved tracer released at the sea floor are presented for a Pacific and two Atlantic study areas. The scenarios are closely tied to available data by means of simple analytical models and proceed in stages from short time and space scales in the immediate vicinity of a release point to those scales characteristic of ocean basins. The concepts of internal mixing time and residence time in the benthic mixed layer, useful for developing an intuitive feeling for the behavior of a tracer in this feature, are introduced and discussed. We also introduce the concept of domain of occupation, which is useful in drawing distinctions between mixing and stirring in the ocean. From this study it is apparent that reliable estimation of mixing will require careful consideration of the dynamics of the eddy fields in the ocean. Another area in which more information is urgently needed is in the relation of deep isopycnal structure and bottom topography to local near-bottom circulation

  18. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov

    2006-01-01

    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  19. Methodologic Considerations for Quantitative 18F-FDG PET/CT Studies of Hepatic Glucose Metabolism in Healthy Subjects.

    Science.gov (United States)

    Trägårdh, Malene; Møller, Niels; Sørensen, Michael

    2015-09-01

    PET with the glucose analog (18)F-FDG is used to measure regional tissue metabolism of glucose. However, (18)F-FDG may have affinities different from those of glucose for plasma membrane transporters and intracellular enzymes; the lumped constant (LC) can be used to correct these differences kinetically. The aims of this study were to investigate the feasibility of measuring human hepatic glucose metabolism with dynamic (18)F-FDG PET/CT and to determine an operational LC for (18)F-FDG by comparison with (3)H-glucose measurements. Eight healthy human subjects were included. In all studies, (18)F-FDG and (3)H-glucose were mixed in saline and coadministered. A 60-min dynamic PET recording of the liver was performed for 180 min with blood sampling from catheters in a hepatic vein and a radial artery (concentrations of (18)F-FDG and (3)H-glucose in blood). Hepatic blood flow was determined by indocyanine green infusion. First, 3 subjects underwent studies comparing bolus administration and constant-infusion administration of tracers during hyperinsulinemic-euglycemic clamping. Next, 5 subjects underwent studies comparing fasting and hyperinsulinemic-euglycemic clamping with tracer infusions. Splanchnic extraction fractions of (18)F-FDG (E*) and (3)H-glucose (E) were calculated from concentrations in blood, and the LC was calculated as ln(1 - E*)/ln(1 - E). Volumes of interest were drawn in the liver tissue, and hepatic metabolic clearance of (18)F-FDG (mL of blood/100 mL of liver tissue/min) was estimated. For bolus versus infusion, E* values were always negative when (18)F-FDG was administered as a bolus and were always positive when it was administered as an infusion. For fasting versus clamping, E* values were positive in 4 of 5 studies during fasting and were always positive during clamping. Negative extraction fractions were ascribed to the tracer distribution in the large volume of distribution in the prehepatic splanchnic bed. The LC ranged from 0.43 to 2

  20. Rapid dual-tracer PTSM+ATSM PET imaging of tumour blood flow and hypoxia: a simulation study

    International Nuclear Information System (INIS)

    Rust, T C; Kadrmas, D J

    2006-01-01

    Blood flow and hypoxia are interrelated aspects of physiology that affect cancer treatment and response. Cu-PTSM and Cu-ATSM are related PET tracers for blood flow and hypoxia, and the ability to rapidly image both tracers in a single scan would bring several advantages over conventional single-tracer techniques. Using dynamic imaging with staggered injections, overlapping signals for multiple PET tracers may be recovered utilizing information from kinetics and radioactive decay. In this work, rapid dual-tracer PTSM+ATSM PET was simulated and tested as a function of injection delay, order and relative dose for several copper isotopes, and the results were compared relative to separate single-tracer data. Time-activity curves representing a broad range of tumour blood flow and hypoxia levels were simulated, and parallel dual-tracer compartment modelling was used to recover the signals for each tracer. The main results were tested further using a torso phantom simulation of PET tumour imaging. Using scans as short as 30 minutes, the dual-tracer method provided measures of blood flow and hypoxia similar to single-tracer imaging. The best performance was obtained by injecting PTSM first and using a somewhat higher dose for ATSM. Comparable results for different copper isotopes suggest that tracer kinetics with staggered injections play a more important role than radioactive decay in the signal separation process. Rapid PTSM+ATSM PET has excellent potential for characterizing both tumour blood flow and hypoxia in a single, fast scan, provided that technological hurdles related to algorithm development and routine use can be overcome

  1. Study of particle movement in conical fluidized beds using the tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Penkalla, H. J.; Gyarmati, E.; Nickel, H.

    1976-01-15

    In the work reported here, a method is described which enables the path and speed of the particles during fluidization to be measured using a tracer particle technique. Using statistical methods, it is then possible to determine the path-time diagram, the rate of circulation of the particles, the transport capacity, the extent of mixing and the relative residence time of the particles in a given zone of the bed. Measurements were made at room temperature in a 3'' model fluidized bed as a first step in evaluating the feasibility of the test method. Criteria for the type of coating, the growth rate of the coatings and the coating potential of the coating as were correlated with the relative dwell time of the particles and the dwell-time spectrum of the coating gases in a given part of the bed. It was therefore necessary to know the streaming behavior of the fluidizing gas, and so such an analysis was first carried out.

  2. Study of cation diffusion in Zn O using 65Zn as radioactive tracer

    International Nuclear Information System (INIS)

    Ferraz, Wilmar B.; Correa, Ricardo F.; Nogueira, Maria A.N.; Ramos, Marcelo; Sabioni, Antonio C.S.

    2000-01-01

    Zinc self-diffusion coefficient were measured in polycrystalline Zn O of high purity (99,999%) prepared by conventional sintering at 1393 deg C, 4 h, in oxygen atmosphere. The Zn O samples had high density (>99% of the theoretical density) and grain size of 20 μm. These samples were resintered for 72 h at 1400 deg C in order to increase the grain-size higher than 50 μ m. Samples of 15 x 15 x 2 mm 3 were polished with diamond paste, and pre-annealed under the same conditions of temperature and atmosphere of the diffusion annealing. A thin film of 65 Zn - radioactive tracer - applied to the polished surface was oxidized in oxygen atmosphere for a short time before diffusion annealing. The diffusion experiments were performed between 1002 and 1201 deg C in oxygen atmosphere. The 65 Zn diffusion profiles were measured by sectioning in conjunction with residual-activity measurements. The results of the determination of the zinc in Zn O diffusion coefficients in function of temperature are presented and a comparison of these results obtained by the two radioactive method is showed. (author)

  3. Enhanced oil recovery methods studied by gamma tracer scanning at simulated reservoir conditions

    International Nuclear Information System (INIS)

    Eriksen, D.O.; Haugen, O.B.; Bjornstad, T.

    2009-01-01

    During recovery (production) of hydrocarbons pressure is maintained by injecting prepared sea water and recycled gas (lean gas) into dedicated injection wells. In one well at the Snorre field in the North Sea the injected gas was recycled too fast to enable support of pressure and squeezing of oil. To plug this high-permeable area the operator wanted to inject foam as a test of its possibilities to decrease gas permeability. As part of the project laboratory tests were included. In these tests we could for the first time map the foam inside the sandstone sample at simulated reservoir conditions. The tracers used were 22 Na + for the γ-scanning of the aqueous brine, tritiated water for permeability measurements, and 35 S-labeled organic sulfonic acid of the same compound as the surfactant. This method resulted in a 'negative' mapping of the foam, i.e. measurements of the absence or exclusion of the aqueous phase by the foam. This method was new and showed that radiotracer-based γ-scanning could give much more accurate measurements of the position of the foam than the standard method using measurements of pressure drops over parts of the core. (author)

  4. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  5. Metabolic studies of oxyguno in horses

    International Nuclear Information System (INIS)

    Wong, April S.Y.; Ho, Emmie N.M.; Wan, Terence S.M.; Lam, Kenneth K.H.; Stewart, Brian D.

    2015-01-01

    Oxyguno (4-chloro-17α-methyl-17β-hydroxy-androst-4-ene-3,11-dione) is a synthetic oral anabolic androgenic steroid commercially available without a prescription. Manufacturers of oxyguno claim that its anabolic effect in metabolic enhancement exceeds that of the classic anabolic steroid testosterone by seven times, but its androgenic side-effects are only twelve percent of testosterone. Like other anabolic androgenic steroids, oxyguno is prohibited in equine sports. The metabolism of oxyguno in either human or horse has not been reported and therefore little is known about its metabolic fate. This paper describes the in vitro and in vivo metabolic studies of oxyguno in racehorses with an objective to identify the most appropriate target metabolites for detecting oxyguno administration. In vitro studies of oxyguno were performed using horse liver microsomes. Metabolites in the incubation mixtures were isolated by liquid–liquid extraction and analysed by gas chromatography-mass spectrometry in the EI mode after trimethylsilylation. In vitro metabolites identified include the stereoisomers of 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β-diol (M1a & M1b); 20-hydroxy-oxyguno (M2); and 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β,20-triol (M3). These novel metabolites were resulted from hydroxylation at C20, and/or reduction of the keto group at C11. For the in vivo studies, two geldings were each administered orally with a total dose of 210 mg oxyguno (52.5 mg twice daily for 2 days). Pre- and post-administration urine and blood samples were collected for analysis. The parent drug oxyguno was detected in both urine and blood, while numerous novel metabolites were detected in urine. The stereoisomers (M1a & M1b) observed in the in vitro studies were also detected in post-administration urine samples. Three other metabolites (M4 - M6) were detected. M4, 4-chloro-17α-methyl-androstane-11-keto-3,17β-diol, was resulted from reductions of the olefin

  6. Metabolic studies of oxyguno in horses

    Energy Technology Data Exchange (ETDEWEB)

    Wong, April S.Y., E-mail: april.sy.wong-rl@hkjc.org.hk [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Ho, Emmie N.M. [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Wan, Terence S.M., E-mail: terence.sm.wan@hkjc.org.hk [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Lam, Kenneth K.H.; Stewart, Brian D. [Veterinary Regulation & International Liaison, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T, Hong Kong (China)

    2015-09-03

    Oxyguno (4-chloro-17α-methyl-17β-hydroxy-androst-4-ene-3,11-dione) is a synthetic oral anabolic androgenic steroid commercially available without a prescription. Manufacturers of oxyguno claim that its anabolic effect in metabolic enhancement exceeds that of the classic anabolic steroid testosterone by seven times, but its androgenic side-effects are only twelve percent of testosterone. Like other anabolic androgenic steroids, oxyguno is prohibited in equine sports. The metabolism of oxyguno in either human or horse has not been reported and therefore little is known about its metabolic fate. This paper describes the in vitro and in vivo metabolic studies of oxyguno in racehorses with an objective to identify the most appropriate target metabolites for detecting oxyguno administration. In vitro studies of oxyguno were performed using horse liver microsomes. Metabolites in the incubation mixtures were isolated by liquid–liquid extraction and analysed by gas chromatography-mass spectrometry in the EI mode after trimethylsilylation. In vitro metabolites identified include the stereoisomers of 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β-diol (M1a & M1b); 20-hydroxy-oxyguno (M2); and 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β,20-triol (M3). These novel metabolites were resulted from hydroxylation at C20, and/or reduction of the keto group at C11. For the in vivo studies, two geldings were each administered orally with a total dose of 210 mg oxyguno (52.5 mg twice daily for 2 days). Pre- and post-administration urine and blood samples were collected for analysis. The parent drug oxyguno was detected in both urine and blood, while numerous novel metabolites were detected in urine. The stereoisomers (M1a & M1b) observed in the in vitro studies were also detected in post-administration urine samples. Three other metabolites (M4 - M6) were detected. M4, 4-chloro-17α-methyl-androstane-11-keto-3,17β-diol, was resulted from reductions of the olefin

  7. Tracer transport in fractured rocks

    International Nuclear Information System (INIS)

    Tsang, C.F.; Tsang, Y.W.; Hale, F.V.

    1988-07-01

    Recent interest in the safety of toxic waste underground disposal and nuclear waste geologic repositories has motivated many studies of tracer transport in fractured media. Fractures occur in most geologic formations and introduce a high degree of heterogeneity. Within each fracture, the aperture is not constant in value but strongly varying. Thus for such media, tracer tends to flow through preferred flowpaths or channels within the fractures. Along each of these channels, the aperture is also strongly varying. A detailed analysis is carried out on a 2D single fracture with variable apertures and the flow through channels is demonstrated. The channels defined this way are not rigidly set pathways for tracer transport, but are the preferred flow paths in the sense of stream-tubes in the potential theory. It is shown that such variable-aperture channels can be characterized by an aperture probability distribution function, and not by the exact deterministic geometric locations. We also demonstrate that the 2D tracer transport in a fracture can be calculated by a model of a system of 1D channels characterized by this distribution function only. Due to the channeling character of tracer transport in fractured rock, random point measurements of tracer breakthrough curves may give results with a wide spread in value due to statistical fluctuations. The present paper suggests that such a wide spread can probably be greatly reduced by making line/areal (or multiple) measurements covering a few spatial correlation lengths. 13 refs., 11 figs., 1 tab

  8. Evaluation of short-term tracer fluctuations in groundwater and soil air in a two year study

    Science.gov (United States)

    Jenner, Florian; Mayer, Simon; Aeschbach, Werner; Weissbach, Therese

    2016-04-01

    The application of gas tracers like noble gases (NGs), SF6 or CFCs in groundwater studies such as paleo temperature determination requires a detailed understanding of the dynamics of reactive and inert gases in the soil air with which the infiltrating water equilibrates. Due to microbial gas consumption and production, NG partial pressures in soil air can deviate from atmospheric air, an effect that could bias noble gas temperatures estimates if not taken into account. So far, such an impact on NG contents in groundwater has not been directly demonstrated. We provide the first long-term study of the above mentioned gas tracers and physical parameters in both the saturated and unsaturated soil zone, sampled continuously for more than two years near Mannheim (Germany). NG partial pressures in soil air correlate with soil moisture and the sum value of O2+CO2, with a maximal significant enhancement of 3-6% with respect to atmospheric air during summer time. Observed seasonal fluctuations result in a mass dependent fractionation of NGs in soil air. Concentrations of SF6 and CFCs in soil air are determined by corresponding fluctuations in local atmospheric air, caused by industrial emissions. Arising concentration peaks are damped with increasing soil depth. Shallow groundwater shows short-term NG fluctuations which are smoothed within a few meters below the water table. A correlation between NG contents of soil air and of groundwater is observable during strong recharge events. However, there is no evidence for a permanent influence of seasonal variations of soil air composition on shallow groundwater. Fluctuating NG contents in shallow groundwater are rather determined by variations of soil temperature and water table level. Our data gives evidence for a further temperature driven equilibration of groundwater with entrapped air bubbles within the topmost saturated zone, which permanently occurs even some years after recharge. Local subsurface temperature fluctuations

  9. Radioisotope tracer study in a pilot-scale trickle bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H.J.; Pendharkar, A.S. [Bhabha Atomic Research Centre, Isotope Applications Div, Bombay (India); Prasad, J.S.; Maiti, R.N.; Chawla, R.; Lahri, R.N.; Ram Babu, D. [Engineers India Limited, Gurgaon, Haryana (India); Berne, Ph. [CEA Grenoble, DTEN/SAT, 38 (France)

    2001-07-01

    Trickle bed reactor (TBR) is a reactor in which a liquid and a gas phase flow concurrently downwards through a fixed bed of catalyst particles while the reaction takes place. The trickle bed reactors find a number of applications in petroleum refining, chemical. petro-chemical and bio-chemical processes due to their suitability for hydro-processing operations.The knowledge of radial distribution, mean residence time (MRT). liquid holdup and degree of axial mixing is a basic requirement to evaluate the reactor performance of a TBR, its optimal size, the physical and chemical interactions and the pumping requirements. Measurement and analysis of residence time distribution (RTD) of liquid phase facilitate the determination of these parameters. This paper describes the measurement of RTD of liquid phase in a pilot-scale trickle bed reactor operating at high pressure. Kerosene and nitrogen were used as liquid and gas phase, respectively. Porous alumina catalyst particles were used as packing. Bromine-82 as para-di-bromo benzene was used as a tracer to measure RTD of organic liquid phase. The RTD of kerosene was measured as a function of liquid and gas flow rates and pressure. The axial dispersion model with exchange between active and dead zones was proposed and used to simulate the measured RTD data and model parameters i.e mean residence time ({tau}), Peclet Number (Pe), dynamic fraction of the liquid ({phi}) and the number of transfer units (N) were obtained. The results of the simulations indicated intermediate degree of axial mixing of liquid phase. The RTD predicted by the axial dispersion model with exchange between active and dead zones fits well to the experimentally measured RTD data and thus is a suitable model to describe the dynamics of the liquid phase in TBRs filled with porous catalyst particles. (authors)

  10. Application of tracer isotope in kinetic study of first order ion exchange reaction

    International Nuclear Information System (INIS)

    Lokhande, R.S.; Singare, P.U.

    1998-01-01

    Analysis of first order ion exchange reaction rates at different temperatures (27 deg- 48 degC) and particularly at low concentration of potassium iodide solution (electrolyte) ranging from 0.005 M to 0.040 M is carried out by application of radioactive tracer isotope 131 I. With increase in concentration of electrolyte, amount of iodide ion exchanged in millimoles increases. Specific reaction rates of ion exchange reaction are calculated for different temperatures and for different amount of ion exchange resins. It is observed that with increase in temperature, reaction rate increases but the increase is more pronounced for increase in amount of ion exchange resins. For 0.005 M solution of electrolyte, the reaction rate increases from 0.121 min -1 at 27 degC to 0.178 min -1 at 48 degC. For 0.005 M solution of electrolyte the reaction rate increases from 0.121 min -1 at 27 degC to 0.178 min 1 at 48 degC. For 0.005 M solution of electrolyte at 27 degC the reaction rate increases from 0.121 min -1 for 1.0 g of resin to 0.368 min -1 for 5.0 g of resin. From the reaction rates calculated at different temperatures, energy of activation in kJ/mole is calculated. It is observed that for 0.005 M solution of electrolyte, energy of activation is 4.62 kJ/mole which decreases to 2.87 kJ/mole for increase in concentration of electrolyte to 0.100 M. (author)

  11. When tractography meets tracer injections: a systematic study of trends and variation sources of diffusion-based connectivity.

    Science.gov (United States)

    Aydogan, Dogu Baran; Jacobs, Russell; Dulawa, Stephanie; Thompson, Summer L; Francois, Maite Christi; Toga, Arthur W; Dong, Hongwei; Knowles, James A; Shi, Yonggang

    2018-04-16

    Tractography is a powerful technique capable of non-invasively reconstructing the structural connections in the brain using diffusion MRI images, but the validation of tractograms is challenging due to lack of ground truth. Owing to recent developments in mapping the mouse brain connectome, high-resolution tracer injection-based axonal projection maps have been created and quickly adopted for the validation of tractography. Previous studies using tracer injections mainly focused on investigating the match in projections and optimal tractography protocols. Being a complicated technique, however, tractography relies on multiple stages of operations and parameters. These factors introduce large variabilities in tractograms, hindering the optimization of protocols and making the interpretation of results difficult. Based on this observation, in contrast to previous studies, in this work we focused on quantifying and ranking the amount of performance variation introduced by these factors. For this purpose, we performed over a million tractography experiments and studied the variability across different subjects, injections, anatomical constraints and tractography parameters. By using N-way ANOVA analysis, we show that all tractography parameters are significant and importantly performance variations with respect to the differences in subjects are comparable to the variations due to tractography parameters, which strongly underlines the importance of fully documenting the tractography protocols in scientific experiments. We also quantitatively show that inclusion of anatomical constraints is the most significant factor for improving tractography performance. Although this critical factor helps reduce false positives, our analysis indicates that anatomy-informed tractography still fails to capture a large portion of axonal projections.

  12. Tracer Study of Dentistry Graduates of one Higher Education Institution in the Philippines from 2008 to 2012

    Directory of Open Access Journals (Sweden)

    Jennifer D. Maderazo

    2016-08-01

    Full Text Available This tracer study determines the employment status of the graduates of Doctor of Dental Medicine of Lyceum of the Philippines University (LPU from 2008-2012. It assessed the relevance of the Dentistry curriculum, knowledge, skills and attitude acquired by the graduates deemed to be relevant for their employment; identify the personal and professional characteristics and job placement of Dentistry graduates and the school related factors associated with their employment. This tracer study used a descriptive research design. The study described the experiences of the graduates before and after employment. The graduates conveyed their personal observations regarding the situations they faced after graduation. The findings showed that majority of the Dentistry graduate-respondents are presently employed except for one whose primary reason is family concern and decided not to find a job. Most of the graduates had their first job as associate dentist with recommendation from the department or alumni of the college and opted to put up their own private practice after 6 months. Rewarding salaries and benefits are the main reason for staying on the job and are all enjoying a professional career in dentistry with initial gross income of 25,000 pesos and above. The following school related factors for job placement such as curriculum and instruction for the general education and professional subjects, student services and faculty instruction were found to be relevant in meeting the demands of the graduates’ dental profession. And the following are the work related values gained by the graduates such a love for God, honesty and truth, professional integrity and leadership. These values were found to be very relevant in the practice of the profession.

  13. On the use of flow-storage repartitions derived from artificial tracer tests for geothermal reservoir characterization in the Malm-Molasse basin: a theoretical study

    Science.gov (United States)

    Dewi, Dina Silvia; Osaigbovo Enomayo, Augustine; Mohsin, Rizwan; Karmakar, Shyamal; Ghergut, Julia; Sauter, Martin

    2016-04-01

    needed to calculate FSR. Looking at the Sauerlach example, we find that premature interruption of tracer sampling systematically leads to overestimating the reservoir's storage capacity and underestimating its flow capacity, with misestimation generally increasing as the bedded/reef interfacial area per volume is increased. It is interesting to correlate these findings with the tracer-based approach to facies identification for the shallower Malm aquifers of the Southern Franconian Alb, proposed by Seiler et al. (1989, 1995) and with expectations from the direct (i. e., distributed-parameter) modeling of matrix-diffusive effects (Maloszewski and Zuber 1985) on measured tracer signals. References: Maloszewski P, Zuber A (1985) On the theory of tracer experiments in fissured rocks with a porous matrix, Journal of Hydrology, 79, 333-358 Seiler K-P, Behrens H, Wolf M (1995) Use of artificial and environmental tracers to study storage and drainage of groundwater in the Franconian Alb, Germany, and the consequences for groundwater protection, Proc Isotopes in Water Resources Management, 2, 135-146 (IAEA, Vienna) Seiler K-P, Maloszewski P, Behrens H (1989) Hydrodynamic dispersion in karstified limestones and dolomites in the Upper Jurassic of the Franconian Alb, FRG, Journal of Hydrology, 108, 235-247 Shook G M (2003) A Simple, Fast Method of Estimating Fractured Reservoir Geometry from Tracer Tests, Geothermal Resources Council Transactions, 27, 407-411 Financial support from the German Federal Ministry for Economic Affairs and Energy is gratefully acknowledged. - Gefördert durch BMWi aufgrund eines Beschlusses des Deutschen Bundestages (FKZ 0325515 "TRENDS").

  14. Metabolic and improved organ scan studies. III. 13N-ammonia metabolic studies in hepatic encephalopathy

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Results are reported from an investigation into the nature of hepatic encephalopathy, through study of the uptake and metabolism of 13 N-labeled ammonia by the brain in relation to liver function, in order to develop improved methods for the management of patients with this condition

  15. A pilot study of the feasibility of long-term human bone balance during perimenopause using a 41Ca tracer

    International Nuclear Information System (INIS)

    Hui, S.K.; Prior, J.; Gelbart, Z.; Johnson, R.R.; Lentle, B.C.; Paul, M.

    2007-01-01

    The mechanisms governing calcium fluxes during bone remodeling processes in perimenopausal women are poorly known. Despite higher, albeit erratic, estradiol levels in perimenopause, spine bone loss is greater than during the first five years past the final menstrual flow when estradiol becomes low. Understanding changes during this dynamic transition are important to prevent fragility fractures in midlife and older women. The exploration of long-lived 41 Ca (T 1/2 = 1.04 x 10 5 yrs) tracer measurements using accelerator mass spectrometry (AMS) leads to the possibility of monitoring bone remodeling balance. With this new technology, we explored a pilot long-term feasibility study of bone health by measuring the 41 Ca trace element in urine for six years from premenopausal to later perimenopausal phases in one midlife woman. We measured bone mineral density in parallel

  16. Preparation of 19-iodocholestrol labelled with I-125 and its study as a 'tracer' of plasma lipoprotein

    International Nuclear Information System (INIS)

    Rodriquez Barquero, L.

    1988-01-01

    A technique of synthesis of the 19-iodocholesterol labelled with I-125, modified in some steps from other methods published previously, is described. We have obtained a product with high chemical (96%) and radiochemical (99,9%) purities. The yield was higher and the time necessary to prepare it was lower than other methods reported. The study of thermal and radiolytic stability showed that the 19-iodocholesterol-I-125 was not broken by autoradiolysis whereas the I-125 was separated from the molecule when the temperature was increased. The use of this 19-iodocholesterol-I-125 as a tracer of cholesterol of plasma lipoprotein showed some properties of LCAT and CETP and also showed the different capacity of VLDL and LDL to transport cholesteryl esters. (author) 105 refs

  17. Transient tracers in the ocean (TTO) program: the North Atlantic study, 1981: the Tropical Atlantic study, 1983

    International Nuclear Information System (INIS)

    Brewer, P.G.; Sarmiento, J.L.; Smethie, W.M. Jr.

    1985-01-01

    The two parts of this major geochemical and physical oceanographic expedition took place on the research vessel Knorr of the Woods Hole Oceanographic Institution. The expeditions were designed to observe the passage of man-made geochemical tracers into the interior of the ocean. A systematic survey revealed the penetration into the thermocline and deep ocean of the products of man's military/industrial activities, principally tritium and carbon-14 resulting from atmospheric testing of nuclear weapons. The passage of these tracers documents as nothing else can the manner and time scale of ocean mixing and provides a fundamental calibration for models of ocean circulation. Maps showing the cruise routes are presented. 1 figure, 1 table

  18. Emission tomography: quantitative aspects in metabolic and physio-pathologic studies

    International Nuclear Information System (INIS)

    Yerouchalmi-Soussaline, F.

    1984-01-01

    This thesis presents instrumental and data processing studies developed in emission tomography in man, using gamma and positron emitting tracers. High contrast visualisation of volume distribution of tracers in the organs, kinetic studies and measurements of radioactive concentration or of other clinical parameters necessitate a detailed analysis of all physical factors limiting the accuracy of the measure; therefore, development of adapted imaging devices and data processing techniques, together with models describing correctly the phenomena under study are to be carried out. Thus, in single photon (gamma) emission tomography an image reconstruction strategy is elaborated, based on an analytical model for the ill-posed problem including the attenuation effect. In positron emission tomography, the time-of-flight information combined with the reconstruction technique is used in the design of a first prototype imaging device which performance is presented and evaluated in a clinical environment. Moreover, a priori or a posteriori techniques correcting for Compton diffusion events, limited statistics and limited resolution, are proposed and discussed for the improvement of regional measurement accuracy, in metabolic and physio-pathologic studies. (author) [fr

  19. Radioactive tracers in the sea

    International Nuclear Information System (INIS)

    Jenkins, W.J.; Livingston, H.D.

    1980-01-01

    Artificial radionuclides introduced to the oceans during the last four decades have proved invaluable tools for study of many processes in marine water columns and sediments. Both global and close-in fallout of radioactivity from atmospheric nuclear weapons testing have distributed these radionuclides widely, and in amounts sufficient to be useful as tracers. An additional source of considerable significance and tracer potential comes from coastal discharges of European nuclear fuel reprocessing wastes. The nature of these sources, types and amounts of radionuclides introduced and the time histories of their introduction generate a variety of tracer distributions which illuminate a broad spectrum of physical and chemical processes active over a wide range of timescales. Depending on their respective chemistries, artificial radionuclides have been demonstrated to exhibit both conservative and non-conservative properties in the oceans. Some examples are given of the uses made of soluble, conservative tracers for the study of oceanic transport processes and of non-conservative tracers for studies of processes which move them to, and mix them within, marine sediments. Sampling and measurement techniques which have been used in these studies are described

  20. Prediction of iodine-131 biokinetics and radiation doses from therapy on the basis of tracer studies: an important question for therapy planning in nuclear medicine.

    Science.gov (United States)

    Willegaignon, José; Pelissoni, Rogério A; Lima, Beatriz C G D; Sapienza, Marcelo T; Coura-Filho, George B; Buchpiguel, Carlos A

    2016-05-01

    This study aimed to present a comparison of iodine-131 (I) biokinetics and radiation doses to red-marrow (rm) and whole-body (wb), following the administration of tracer and therapeutic activities, as a means of confirming whether I clearance and radiation doses for therapy procedures can be predicted by tracer activities. Eleven differentiated thyroid cancer patients were followed after receiving tracer and therapeutic I activity. Whole-body I clearance was estimated using radiation detectors and OLINDA/EXM software was used to calculate radiation doses to rm and wb. Tracer I activity of 86 (±14) MBq and therapeutic activity of 8.04 (±1.18) GBq were administered to patients, thereby producing an average wb I effective half-time and residence time of, respectively, 13.51 (±4.05) and 23.13 (±5.98) h for tracer activities and 13.32 (±3.38) and 19.63 (±4.77) h for therapy. Radiation doses to rm and wb were, respectively, 0.0467 (±0.0208) and 0.0589 (±0.0207) mGy/MBq in tracer studies and 0.0396 (±0.0169) and 0.0500 (±0.0163) mGy/MBq in therapy. Although the differences were not considered statistically significant between averages, those between the values of effective half-times (P=0.906), residence times (P=0.145), and radiation doses to rm (P=0.393) and to wb (P=0.272), from tracer and therapy procedures, large differences of up to 80% in wb I clearance, and up to 50% in radiation doses were observed when patients were analyzed individually, thus impacting on the total amount of I activity calculated to be safe for application in individual therapy. I biokinetics and radiation doses to rm and wb in therapy procedures are well predicted by diagnostic activities when average values of a group of patients are compared. Nonetheless, when patients are analyzed individually, significant differences may be encountered, thus implying that nuclear medicine therapy-planning requires due consideration of changes in individual patient-body status from

  1. Relationships among personality traits, metabolic syndrome, and metabolic syndrome scores: The Kakegawa cohort study.

    Science.gov (United States)

    Ohseto, Hisashi; Ishikuro, Mami; Kikuya, Masahiro; Obara, Taku; Igarashi, Yuko; Takahashi, Satomi; Kikuchi, Daisuke; Shigihara, Michiko; Yamanaka, Chizuru; Miyashita, Masako; Mizuno, Satoshi; Nagai, Masato; Matsubara, Hiroko; Sato, Yuki; Metoki, Hirohito; Tachibana, Hirofumi; Maeda-Yamamoto, Mari; Kuriyama, Shinichi

    2018-04-01

    Metabolic syndrome and the presence of metabolic syndrome components are risk factors for cardiovascular disease (CVD). However, the association between personality traits and metabolic syndrome remains controversial, and few studies have been conducted in East Asian populations. We measured personality traits using the Japanese version of the Eysenck Personality Questionnaire (Revised Short Form) and five metabolic syndrome components-elevated waist circumference, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose-in 1322 participants aged 51.1±12.7years old from Kakegawa city, Japan. Metabolic syndrome score (MS score) was defined as the number of metabolic syndrome components present, and metabolic syndrome as having the MS score of 3 or higher. We performed multiple logistic regression analyses to examine the relationship between personality traits and metabolic syndrome components and multiple regression analyses to examine the relationship between personality traits and MS scores adjusted for age, sex, education, income, smoking status, alcohol use, and family history of CVD and diabetes mellitus. We also examine the relationship between personality traits and metabolic syndrome presence by multiple logistic regression analyses. "Extraversion" scores were higher in those with metabolic syndrome components (elevated waist circumference: P=0.001; elevated triglycerides: P=0.01; elevated blood pressure: P=0.004; elevated fasting glucose: P=0.002). "Extraversion" was associated with the MS score (coefficient=0.12, P=0.0003). No personality trait was significantly associated with the presence of metabolic syndrome. Higher "extraversion" scores were related to higher MS scores, but no personality trait was significantly associated with the presence of metabolic syndrome. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Principles and techniques of gamma ray tracers

    International Nuclear Information System (INIS)

    Claxton, K.T.

    1978-01-01

    Radioactive tracer techniques provide a very sensitive means of studying physical and chemical processes in a whole variety of different media. Some of the techniques and principles of radioactive tracers and their application to practical engineering systems are discussed. Information which has been found useful in the design of high temperature liquid sodium facilities employing radio-tracers, is presented. The report deals solely with the use of gamma-emitting species as the tracer. These find particular application for in-situ studies on engineering systems where the highly penetrating properties of gamma rays are needed for detection through strongly absorbent media such as stainless steel pepe walls. (author)

  3. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  4. Tracer gas dispersion in ducts-study of a new compact device using arrays of sonic micro jets

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.R. [Instituto Nacional de Engenharia e Tecnologia Industrial (INETI), Lisboa (Portugal); Afonso, C.F. [Faculdade de Engenharia, Universidade do Porto Departmento de Mecanica e Gestao Industrial, Porto (Portugal)

    2004-07-01

    One of the most feasible ways to measure duct airflows is by tracer gas techniques, especially for complex situations when the duct lengths are short as well as their access, which makes extremely difficult or impossible other methods to be implemented. One problem associated with the implementation of tracer gas technique when the ducts lengths are short is due to the impossibility of achieving complete mixing of the tracer with airflow and its sampling. In this work, the development of a new device for the injection of tracer gas in ducts is discussed as well as a new tracer-sampling device. The developed injection device has a compact tubular shape, with magnetic fixation to be easy to apply in duct walls. An array of sonic micro jets in counter current direction, with the possibility of angular movement according to its main axle ensures a complete mixing of the tracer in very short distances. The tracer-sampling device, with a very effective integration function, feeds the sampling system for analysis. Both devices were tested in a wind tunnel of approximately 21 m total length. The tests distances between injection and integration device considered were: X/Dh = 22; X/Dh = 4; X/Dh 2; and X/Dh = 1. For very short distances of X/Dh = 2 and X/Dh = 1, semi-empirical expressions were needed. A good reproducibility of airflow rate values was obtained. These preliminary tests showed that the practical implementation of tracer gas techniques in HVAC systems for measuring airflow rates with a very short mixing distance is possible with the devices developed. (author)

  5. Present stage of the use of radioactive tracers in studies carried out at Companhia de Tecnologia de Saneamento Ambiental, SP, Brazil, in the field of environmental engineering

    International Nuclear Information System (INIS)

    Sanchez, W.; Agudo, E.G.

    1979-01-01

    Studies using radioactive tracers in the field of environmental engineering, carried out at Companhia de Tecnologia de Saneamento Ambiental, SP, Brazil, from 1975 to 1978 are presented. Future research to be developed in this area is also discussed. (M.A.) [pt

  6. Study on adsorption of activated carbon fiber to background-level xenon in air by the method of 133Xe tracer

    International Nuclear Information System (INIS)

    Zhang Haitao; Wang Yalong; Zhang Lixing; Wang Xuhui; Zhang Xiaolin

    2001-01-01

    The adsorption behaviors of the different activated carbon fibers to ultra-trace xenon in air are studied using the method of 133 Xe as tracer. The efficiency equation of adsorption columns are determined. The comparison of adsorptive capacity between activated carbon fibers and activated carbon indicates that activated carbon fibers are better than activated carbon under low temperature

  7. Fundamental study on the response analysis of liquid tracer in gas-liquid, two-phase steady flow in porous media; Takoshitsu sonai kieki niso teijoryu ni okeru ekiso tracer no oto kaiseki ni kansuru kisoteki kento

    Energy Technology Data Exchange (ETDEWEB)

    Haga, D; Niibori, Y; Chida, T [Tohoku University, Sendai (Japan)

    1998-10-25

    Fluids in geothermal reservoirs are not necessarily in the single phase but is occasionally in the gas-liquid double phase. This study aims to collect fundamental knowledge about the analysis of tracer responses in a gas-liquid two-phase flow, with special attention paid to the movement of substances in the liquid-phase portion of the two-phase flow. A tracer test is conducted in a glass bead-filled layer, and then it is found that the conventional mixture-diffusion model fails to explain the outcome of the test conducted using the said very simple apparatus. The failure is attributed to the coexistence of high-saturation and low-saturation layers throughout the glass bead-filled layer, and a mathematical model is formulated, which is a development from the two-fractured-layer (TFL) model. It turns out that the mathematical model excellently describes the test result that the mixture-diffusion model fails to explain. In the numerical solution of this problem, the validity is confirmed of the use of the SIMPLEX method for the estimation of the effect of the numerical dispersion term of the third-order accurate finite upstream difference method, and of unknown parameters. 31 refs., 7 figs., 1 tab.

  8. Doublet Tracer Testing in Klamath Falls, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, J.S.; Johnson, S.E.; Horne, R.N.; Jackson, P. B. [Pet. Eng. Dept., Stanford University; Culver, G.G. [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

    0001-01-01

    A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

  9. Doublet Tracer Testing in Klamath Falls, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, J S; Johnson, S E; Horne, R N; Jackson, P B [Pet. Eng. Dept., Stanford University; Culver, G G [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

    0000-12-30

    A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

  10. Generalized decrease in brain glucose metabolism during fasting in humans studied by PET

    International Nuclear Information System (INIS)

    Redies, C.; Hoffer, L.J.; Beil, C.

    1989-01-01

    In prolonged fasting, the brain derives a large portion of its oxidative energy from the ketone bodies, beta-hydroxybutyrate and acetoacetate, thereby reducing whole body glucose consumption. Energy substrate utilization differs regionally in the brain of fasting rat, but comparable information has hitherto been unavailable in humans. We used positron emission tomography (PET) to study regional brain glucose and oxygen metabolism, blood flow, and blood volume in four obese subjects before and after a 3-wk total fast. Whole brain glucose utilization fell to 54% of control (postabsorptive) values (P less than 0.002). The whole brain rate constant for glucose tracer phosphorylation fell to 51% of control values (P less than 0.002). Both parameters decreased uniformly throughout the brain. The 2-fluoro-2-deoxy-D-glucose lumped constant decreased from a control value of 0.57 to 0.43 (P less than 0.01). Regional blood-brain barrier transfer coefficients for glucose tracer, regional oxygen utilization, blood flow, and blood volume were unchanged

  11. Radiochemical tracers in marine biology

    International Nuclear Information System (INIS)

    Petrocelli, S.R.; Anderson, J.W.; Neff, J.M.

    1977-01-01

    Tracers have been used in a great variety of experimentation. More recently, labeled materials have been applied in marine biological research. Some of the existing tracer techniques have been utilized directly, while others have been modified to suit the specific needs of marine biologists. This chapter describes some of the uses of tracers in marine biological research. It also mentions the problems encountered as well as offering possible solutions and discusses further applications of these techniques. Only pertinent references are cited and additional information may be obtained by consulting these references. Due to their relative ease of maintenance, freshwater species are also utilized in studies which involve radiotracer techniques. Since most of these techniques e directly applicable to marine species, some of these studies will also be included

  12. Radioisotope tracer applications in industry

    International Nuclear Information System (INIS)

    Rao, S.M.

    1987-01-01

    Radioisotope tracers have many advantages in industrial trouble-shooting and studies on process kinetics. The applications are mainly of two types: one leading to qualitative (Yes or No type) information and the other to quantitative characterisation of flow processes through mass balance considerations and flow models. ''Yes or No'' type methods are mainly used for leakage and blockage locations in pipelines and in other industrial systems and also for location of water seepage zones in oil wells. Flow measurements in pipelines and mercury inventory in electrolytic cells are good examples of tracer methods using the mass balance approach. Axial dispersion model and Tanks-in-Series model are the two basic flow models commonly used with tracer methods for the characterisation of kinetic processes. Examples include studies on flow processes in sugar crystallisers as well as in a precalcinator in a cement plant. (author). 18 figs

  13. Quadratic tracer dynamical models tobacco growth

    International Nuclear Information System (INIS)

    Qiang Jiyi; Hua Cuncai; Wang Shaohua

    2011-01-01

    In order to study the non-uniformly transferring process of some tracer dosages, we assume that the absorption of some tracer by tobacco is a quadratic function of the tracer quantity of the tracer in the case of fast absorption, whereas the exclusion of the tracer from tobacco is a linear function of the tracer quantity in the case of slow exclusion, after the tracer is introduced into tobacco once at zero time. A single-compartment quadratic dynamical model of Logistic type is established for the leaves of tobacco. Then, a two-compartment quadratic dynamical model is established for leaves and calms of the tobacco. Qualitative analysis of the models shows that the tracer applied to the leaves of the tobacco is excluded finally; however, the tracer stays at the tobacco for finite time. Two methods are also given for computing the parameters in the models. Finally, the results of the models are verified by the 32 P experiment for the absorption of tobacco. (authors)

  14. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  15. Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations

    International Nuclear Information System (INIS)

    Helfer, Andreas

    2013-01-01

    With the growing importance of positron emission tomography (PET) for in vivo imaging in diagnostic medicine there is great interest of developing new labelling methods for the positron emitter selenium-73. As attractive application an examination of a no-carrier-added (n.c.a.) preparation of the analogous tracer Sulindac Selenid and of the selenium containing compound Ebselen was examined with 73,75 Se. First of all a labelling strategy for Sulindac Selenid based on a protected precursor was developed. This precursor should further be transformed into the corresponding standard compound for chomatographic identification of the n.c.a. product. This, however, was not possible. An alternative synthesis method also did not result in a product. Thus, a radioactive labelling in case of Sulindac Selenid was not indicated in spite of a successful synthesis of a precursor. The preparation of Ebselen was performed as earlier described by a sequential one-pot synthesis with a yield of 46 %. An adaption of the reaction parameters to a radiosynthesis with 75 Se failed on the n.c.a. state and also after adding carrier to the reaction mixture. The desired product could, however, be prepared in a copper catalysed one-pot radiosynthesis for the first time under carrier-added conditions. Here, optimized conditions resulted in radiochemical yields of 60 ± 18 %. A no-carrier-added product could finally be achieved using sulphur as nonisotopic carrier in the reaction mixture. After optimisation of reaction parameters n.c.a. [ 75 Se]Ebselen could be synthesized with radiochemical yields of 55 ± 7 % within 4 h. Furthermore the desired product could be separated by RHPL-chromatography from its co-produced sulfur-analogue. After transferring the conditions to radiosyntheses with the positron emitter 73 Se, n.c.a. [ 73 Se]Ebselen could be achieved with a radiochemical yield of 22 ± 1 % and can now be used as a potential radiotracer in preclinical evaluation studies with respect to

  16. Longitudinal study on osteoarthritis and bone metabolism

    Directory of Open Access Journals (Sweden)

    L. Postiglione

    2011-09-01

    Full Text Available Objective: The relationship between Osteoarthritis (OA and Osteoporosis (OP is not well defined due to lacking in longitudinal data, mainly regarding correlations between biochemical factors and OA incidence. Aim of this paper was to investigate the predictive value for OA incidence of bone mass variations and of selected biochemical markers in healthy women participating in a population-based longitudinal study carried out in Naples (Italy. Subjects and Methods: High completion rate (85.2% and statistically adequate sample size were obtained: 139 women (45 to 79 years of age were examined and follow up visit was performed after two years (24±2 months, following the same protocol. Patients underwent medical examination, questionnaire, anthropometric measurements, blood sampling and urine collection. Bone mineral density (BMD measurement was performed by dual energy X-ray absorptiometry (DEXA at the lumbar spine (L1-L4 and femoral neck. Radiographs of dorsal and lumbar spine in lateral view were performed at basal and at 24 months visits; a team of three experts scored radiographs using Kellegren and Lawrence grading. Results: The score was calculated for two individual radiographic features (narrowing of the joint space, presence of osteophytes and as a global score. Results show a relevant percentage, 23% up, of subjects presenting both OA and OP. In the cross-sectional study the presence of osteophytosis correlates with anthropometric variables and PTH levels. In the longitudinal study results show a correlation between serum vitamin D and delta score for osteophytosis (β=0.02 p<0.05. Conclusions: Data obtained outline the importance of further studies on the pathogenetic link between OA and bone metabolism.

  17. 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).

  18. Open and Distance Education Systems: do they enhance Graduates' Soft Skills? The results from 2009 Universitas Terbuka Tracer Study

    Directory of Open Access Journals (Sweden)

    Dewi Juliah Ratnaningsih

    2013-11-01

    Full Text Available The vision and mission of Universitas Terbuka (UT is to become a highly qualified open and distance education institution and to provide higher education access to all communities. Graduates of UT are expected to acquire adequate knowledge, hard skills and soft skills. Soft skills play important roles in the world of work. The aim of this article is to describe: (1 whether the open and distance education systems are capable of providing graduates with soft skills, (2 how soft skills are acquired during the period of study, and (3 how are the range of soft skills acquired by graduates and required by stakeholders at work. This article uses 2009 UT tracer study, which employed survey and in-depth interviews to selected respondents and stakeholders. 2.417 pairs data (graduates and stakeholders were analysed. The rating scales were from 1 (very poor to 4 (excellent. The attributes analysed were personal, interpersonal and situational skills. The results show that learning systems that are based on individual learning and tutorial did provide graduates with soft skills. Graduates and stakeholders perceived interpersonal skills as fair. In general, soft skills required at work were time management, self-confidence, problem solving, creativity and team-work.

  19. Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

    International Nuclear Information System (INIS)

    Barot, N.S.; Bagla, H.K.

    2012-01-01

    The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing 51 Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R 2 value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as ΔG = -2.837 kJ/mol, ΔH = -4.757 kJ/mol and ΔS = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin. (orig.)

  20. Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Barot, N.S.; Bagla, H.K. [Kishinchand Chellaram College, Mumbai (India). Nuclear and Radiochemistry Dept.

    2012-07-01

    The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing {sup 51}Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R{sup 2} value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as {Delta}G = -2.837 kJ/mol, {Delta}H = -4.757 kJ/mol and {Delta}S = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin. (orig.)

  1. In vitro metabolism and permeation studies in rat jejunum

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jensen, K; Steffansen, B

    1999-01-01

    The purpose of these studies was to compare the in vitro absorption of two inorganic chromium(III) compounds: chromium chloride and chromium nitrate, with organic chromium(III)-picolinate; and to investigate if any in vitro metabolism of chromium(VI) takes place. The in vitro metabolism studies...

  2. Study of ketone body kinetics in children by a combined perfusion of 13C and 2H3 tracers

    International Nuclear Information System (INIS)

    Bougneres, P.F.; Ferre, P.

    1987-01-01

    Ketone body kinetics were quantified in six children (3-5 yr old), who were fasted for 13-22 h, by a combined perfusion of [3- 13 C]acetoacetate ([ 13 C]AcAc) and D-(-)-beta-[4,4,4- 2 H3]hydroxybutyrate (beta-[ 2 H3]OHB) and gas chromatography-mass spectrometry analysis. Results were analyzed according to the single-pool (combined enrichments) or the two-accessible pools models. After 20-22 h of fasting, ketone body turnover rate was 30-50 mumol.kg-1.min-1, a rate achieved after several days of fasting in adults. At low ketosis, acetoacetate was the ketone body preferentially synthesized de novo and utilized irreversibly. When ketosis increased, acetoacetate irreversible disposal was not enhanced, since it was largely converted into beta-OHB, whereas beta-OHB irreversible disposal was very much increased. The single-pool and two-pool models gave similar ketone body turnover rates when [ 13 C]AcAc was the tracer, whereas the use of beta-[ 2 H3]OHB gave some more divergent results, especially at low ketosis. These studies demonstrate that ketogenesis is very active in short-term fasted children and that the use of a combined infusion of [ 13 C]AcAc and beta-[ 2 H3]OHB is a convenient way to give insight into individual ketone body kinetics

  3. Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques

    International Nuclear Information System (INIS)

    Sebastian, C.; Maghella, G.; Mamani, E.

    2000-12-01

    Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving

  4. Advances in computer applications in radioactive tracer studies of the circulation

    International Nuclear Information System (INIS)

    Wagner, H.N. Jr.; Klingensmith, W.C. III; Knowles, L.G.; Lotter, M.G.; Natarajan, T.K.

    1977-01-01

    Advances in computer technology since the last IAEA symposium on medical radionuclide imaging have now made possible a new approach to the study of physiological processes that promise to improve greatly our perception of body functions and structures. We have developed procedures, called ''compressed time imaging'' (CTI), that display serial images obtained over periods of minutes and hours at framing rates of approximately 16 to 60 per minute. At other times, ''real'' or ''expanded time imaging'' is used, depending on the process under study. Designed initially to study the beating heart, such multidimensional time studies are now being extended to the cerebral and other regional circulations, as well as to other organ systems. The improved imaging methods provide a new approach to space and time in the study of physiology and are supplemented by quantitative analysis of data displayed on the television screen of the computer. (author)

  5. Protocols to Study Growth and Metabolism in Drosophila.

    Science.gov (United States)

    Strassburger, Katrin; Teleman, Aurelio A

    2016-01-01

    Signaling pathways such as the insulin/insulin-like growth factor pathway concurrently regulate organismal growth and metabolism. Drosophila has become a popular model system for studying both organismal growth and metabolic regulation. Care must be taken, however, when assessing such phenotypes because they are quantitative in nature, and influenced by environment. This chapter first describes how to control animal age and nutrient availability, since growth and metabolism are sensitive to these parameters. It then provides protocols for measuring tissue growth, cell size, and metabolic parameters such as stored lipids and glycogen, and circulating sugars.

  6. Exogenous cycilc AMP and cycilc GMP influence the metabolism of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... well with the metabolic dynamics of exogenous 3H-glycerol within 30 h after injection. Moreover, ... low molecular weight that exist widely in organism and exhibit very ... endogenous tracers for the study of protein and lipid metabolism ..... DM (1998). SAAM ⁄: simulation, analysis, and modeling software for.

  7. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  8. Application of Radionuclide Tracer Techniques in Research on Bio-Effects of Carbon Nanoparticles

    International Nuclear Information System (INIS)

    Zhu Ying; Ran Tiecheng; Li Qingnuan; Xu Jingying; Li Wenxin

    2010-01-01

    There are few effective means to detect and analyze nanomaterials, therefore, radionuclide labeling and tracing techniques play an important role in the studies of interaction between nanoparticles and living systems. This paper briefly summarizes the main results from the application of radionuclide tracer techniques in the studies of interaction between carbon nanoparticles (fullerenes, carbon nanotubes and nano-carbon blacks) and animals and mammalian cells, cites the experimental information on absorption, distribution, metabolism and excretion of nanomaterials, and indicates the signification of these information in the drug development and bio-safety studies of nanomaterials. Based on the novel properties of carbon nanoparticles, the superiority of radionuclide tracer techniques over fluorescent labeling techniques is stressed. It is expected that the radionuclide tracer techniques have an increasing application prospect in the interdisciplinary fields of nanoscience and life science. (authors)

  9. The kinetics of multi-compartmentalized systems, studied by radioactive tracers

    International Nuclear Information System (INIS)

    Gouveia, A.S. de.

    1978-01-01

    The use of compartmental models to investigate kinetic problems is presented. This use is restricted, however, to linear models. As an application of different methods, the kinetic behaviour of haemaccel labelled with iodine 131 is studied, the interval of the physically viable solutions being established. The existence of a class of solutions is explained as a result of lack of knowledge of a complete data set. The possibility of obtaining a single solution is also discussed. The formalism of the program SAAM (Simulation, Analysis and modelling) now judged very important for the study of multi-compartimental analysis is presented. (I.C.R) [pt

  10. Underground flux studies in waste basin of CIPC using natural and artificial tracers (volume I)

    International Nuclear Information System (INIS)

    Minardi, P.S.P.

    1982-10-01

    This report presents studies to be done in wastes basin of CIPC in order to verify the contamination possibility of Rio das Antas basin, by infiltration in subsoil, of liquid wastes proceeding from mineral and industrial complex of Pocos de Caldas to be done up to February/82. (author) [pt

  11. Coupling Cover Crops with Alternative Swine Manure Application Strategies: Manure-15N Tracer Studies

    Science.gov (United States)

    Integration of rye cover crops with alternative liquid swine (Sus scrofa L.) manure application strategies may enhance retention of manure N in corn (Zea mays L.) - soybean [Glycine max (L.) Merr] cropping systems. The objective of this study was to quantify uptake of manure derived-N by a rye (Seca...

  12. Carbon-14 tracer study of polyacrylate polymer in a wastewater plant

    International Nuclear Information System (INIS)

    Martin, J.E.; King, L.W.; Hylko, J.M.

    1990-01-01

    A highly absorbent consumer-product, polyacrylate-polymer material tagged with carbon-14 ( 14 C), was dosed to a standard on-site aerobic wastewater treatment plant which contained a settling chamber, an aeration chamber, and an effluent chamber. Operation of the test plant was essentially the same as that of a control plant even under exaggerated conditions. About 97% of the polymer material was retained in solids deposited in the primary and aeration chambers, and effluent releases were minimal. The use of a 14 C tagging procedure proved to be a successful method for studying the behavior of these complex materials. It may be useful to conduct a further study on retained solids to determine whether microbial decomposition of the polymer material occurs while they remain in typical plants. (author)

  13. Kinetic modeling of receptor-ligand binding applied to positron emission tomographic studies with neuroleptic tracers

    Energy Technology Data Exchange (ETDEWEB)

    Logan, J; Wolf, A P; Shiue, C Y; Fowler, J S

    1987-01-01

    Positron emission tomography (PET) with labeled neuroleptics has made possible the study of neurotransmitter-receptor systems in vivo. In this study we investigate the kinetics of the 3,4-dihydroxyphenylethylamine (dopamine) receptor-ligand binding using PET data from a series of experiments in the baboon with the /sup 18/F-labeled drugs spiperone, haloperidol, and benperidol. Models used to describe these systems are based on first-order kinetics which applies at high specific activity (low receptor occupancy). The parameters governing the uptake and loss of drug from the brain were found by fitting PET data from regions with little or no receptor concentration (cerebellum) and from experiments in which specific binding was blocked by pretreatment with the drug (+)-butaclamol. Receptor constants were determined by fitting data from receptor-containing structures. Correcting the arterial plasma activities (the model driving function) for the presence of drug metabolites was found to be important in the modeling of these systems.

  14. Tracer study on sulphur use efficiency in potato-barley sequence on acid soil of Shimla

    International Nuclear Information System (INIS)

    Sud, K.C.; Sharma, R.C.; Sharma, N.K.

    1999-01-01

    Controlled studies were conducted on acidic soil of Fagu (Shimla) to study the efficiency of labelled ammonium sulphate as effected by farmyard manure (FYM) on potato (Solanum tuberosum L.) and its residual effect on succeeding barley (Hordeum vulgare L.). The direct and residual effects of FYM and sulphur on dry matter yield and S concentration in potato and barley plants were significant. Applied FYM had a positive effect on radioassay values i.e. % Sdff and % S utilization by potato from labelled S carrier, whereas, the residual effect of applied S on barley was more than its direct effect on potato. Results indicate that combined application of S and FYM resulted in 3.4 per cent more S contribution to barley crop and was reflected in % S utilization values. (author)

  15. A study on the cycling of phosphorus in wheat (T. alstivum L.) by tracer technique

    International Nuclear Information System (INIS)

    Dwivedi, R.S.

    1974-01-01

    The cycling of phosphorus was studied in relation to its uptake, retention, release and mineralization during the growth period of wheat crop (S. 308) in pure stand (PS) and mixed stand (MS) by using carrier free 32 P. It was estimated that about 60 kg P 2 O 5 /ha was added to the soil through litter by growing two such crops in a year. The mineralization of phosphorus from the litter was to be two times faster at 6 inches soil depth at semi-saturated soil moisture than surface litter. The dry matter production and re-absorption of litter phosphorus by maize plant growing at the bassal dose of decomposed litter were insignificantly different from those of fertilized soils. All the parameters of phosphorus cycling determined by both the techniques did not differ markedly. For mineralization and especially reabsorption studies, only the radiotracer technique appeared to be most sensitive, easy, reliable and quicker. (author)

  16. Contribution to the study of the behavior of tetravalent technetium at tracer amounts in aqueous media

    International Nuclear Information System (INIS)

    Guennec, J.Y.

    The behavior of /sup 99m/Tc was studied first in perchloric media. Reduction of TcO 4 - by BH 4 - at pH 7 in perchloric medium leads to Tc(IV) as a radiocolloid (20 percent) and soluble TcO 2 (50 percent). Acidification of the medium oxidizes the soluble Tc(IV) fraction. Acid solutions containing only the IV species and free of radiocolloids can be studied using back extraction. Tc(IV) is extracted by the organic phases, containing or not containing TTA or HDEHP from solutions of Tc(VII) reduced by BH 4 - at pH 7. These organic phases are then contacted with aqueous phases 5 x 10 -2 to 3 M HClO 4 , and the variation of the distribution coefficient was studied as a function of the chelating agent content and of the pH. In the absence of a chelating agent, the extracted species is TcO 2 . In the presence of chelating agents, the cation TcO(OH) + is extracted in the forms TcO(OH)A and TcO(OH)A 2 H respectively with TTA and HDEHP. Hydrolysis of this cation leads to TcO 2 . Study of the reduction of Tc(VII) in hydrochloric medium is complicated by the oxychlorinated forms of Tc(IV). The hexachlorotechnetate ion, TcCl 6 , exists in HCl 12 M down to 1 M and is very inert. Addition of chloride ions to solutions containing only TcO 2 and TcO(OH) + , when [Cl - ] is less than 1 M, leads to a neutral extractable species, which could be TcOCl 2 . When the Cl - concentration is greater than 1 M, there is formation of a species with one more chlorine atoms; this could be TcOCl 3 . The behavior of technetium during the formation of the complex ''Tc-Iron-Ascorbic Acid'' used in medical scintigraphy was also studied. Ascorbic acid alone or divalent iron alone slightly reduce the pertechnetate. Addition of Fe 2+ (or BH 4 - ) to Tc(VII) and ascorbic acid produces a high percentage of Tc(IV). So it is the ascorbate of iron which reduces the Tc(VII) and the excess ascorbic acid maintains the technetium in its reduced state by formation of a weak complex

  17. Radioassay of granulocyte chemotaxis. Studies of human granulocytes and chemotactic factors. [/sup 51/Cr tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Gallin, J I

    1974-01-01

    The above studies demonstrate that the /sup 51/Cr radiolabel chemotactic assay is a relatively simple and objective means for studying leukocyte chemotaxis in both normal and pathological conditions. Application of this method to studies of normal human chemotaxis revealed a relatively narrow range of normal and little day-to-day variability. Analysis of this variability revealed that there is more variability among the response of different granulocytes to a constant chemotactic stimulus than among the chemotactic activity of different sera to a single cell source. Utilizing the /sup 51/Cr radioassay, the abnormal granulocyte chemotactic behavior reported in Chediak-Higashi syndrome and a patient with recurrent pyogenic infections and mucocutaneous candidiasis has been confirmed. The /sup 51/Cr chemotactic assay has also been used to assess the generation of chemotactic activity from human serum and plasma. The in vitro generation of two distinct chemotactic factors were examined; the complement product (C5a) and kallikrein, an enzyme of the kinin-generating pathway. Kinetic analysis of complement-related chemotactic factor formation, utilizing immune complexes or endotoxin to activate normal sera in the presence or absence of EGTA as well as kinetic analysis of activation of C2-deficient human serum, provided an easy means of distinguishing the classical (antibody-mediated) complement pathway from the alternate pathway. Such kinetic analysis is necessary to detect clinically important abnormalities since, after 60 min of generation time, normal chemotactic activity may be present despite complete absence or inhibition of one complement pathway. The chemotactic factor generated by either pathway of complement activation appears to be predominately attributable to C5a.

  18. Synthesis of high specific activity carbon-11 labeled tracers for neuroreceptor studies

    International Nuclear Information System (INIS)

    Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Wagner, H.N. Jr; Johns Hopkins Medical Institutions, Baltimore, MD

    1989-01-01

    The use of short-lived positron-emitting radiotracers together with positron emission tomography (PET) has allowed scientists to acquire previously inaccessible information regarding problems in physiology, biochemistry, and pharmacology in the living human body. In the past five years, successes in the application of PET to the non-invasive determination of the spatial distribution and regional concentration of a variety of neurotransmitter binding sites within the living brain often followed the successful selections and syntheses of appropriately radiolabeled ligands. This presentation concentrates on the synthesis of these high specific activity radiotracers for neuroreceptor PET studies labeled specifically with carbon-11. (author). 15 refs.; 1 fig

  19. The biokinetics of Rhuthenium and Zirconium radionuclides in humans studied with stable tracers

    International Nuclear Information System (INIS)

    Veronese, I.; Cantone, M.C.; Giussani, A.

    2002-01-01

    The assessment of the internal radiation dose delivered by radionuclides incorporated in the human body after accidental release into the environment requires the use of suitable biokinetic models. These models describe the absorption of radionuclides into the blood circulation, their distribution and retention in various organs and tissues, and the excretion routes. Biokinetic models are also employed for interpreting bioassay measurements in exposed subjects, like activity concentration measurements in body fluids (e.g. urine, blood), in order to estimate the incorporated amount of radioactive substances. The reliability of a biokinetic model is closely linked to the available experimental data used to develop the model itself. Biokinetic data for human subjects are available for most essential elements, as well as for some important non-essential elements such as caesium, lead, radium, uranium, americium and plutonium. For many other radionuclides, either very little or no information is available from human studies, and the respective models must be derived from other sources. These may include results from studies in animals, comparative data on the behaviour of similar radionuclides or chemical analogues in vitro. Biokinetic models developed from such a variety of data sources can be applied to humans only with a limited degree of confidence. The availability of data directly obtained on human subjects is therefore fundamental to set up more reliable and realistic models. Ruthenium and zirconium are among the elements characterised by a serious lack of reliable data in humans

  20. Isotope tracers in global water and climate studies of the past and present

    International Nuclear Information System (INIS)

    Edwards, T.W.D.; Birks, S.J.; Gibson, J.J.

    2002-01-01

    To date the global distribution of isotopes in modern precipitation has been characterized almost exclusively from the IAEA/WMO GNIP database, although patchiness of GNIP station records in both time and space has limited the potential of isotope hydrology and climate applications in some areas. Herein, we discuss the prospect of utilizing GCMs for simulating global isotope distributions as a supplementary tool for modern and paleoclimate isotope studies to bridge this gap. Such models currently generate reliable zonal isotope fields, and it is anticipated that future enhancements in finescale resolution of GCMs, and incorporation of land-surface feedbacks and topography will allow for future development of a global reanalysis data set ground-truthed by GNIP. Compilation of time-slice maps of past isotope distribution in precipitation from archival records of meteoric waters also offers significant potential to ground-truth paleoclimate simulations extending back tens to hundreds of thousands of years. (author)

  1. Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

    Science.gov (United States)

    Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

    2017-11-01

    Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

  2. pH dependence and unsuitability of fluorescein dye as a tracer for pesticide mobility studies in acid soil

    Science.gov (United States)

    Chris Peterson

    2009-01-01

    The mobility of fluorescein and bromide used as tracers in packed soil columns was investigated.Five different soils were used in two application methods: soil surface application and soil incorporation, both of which simulate accepted methods of soil application of termiticides to prevent structural infestation. The...

  3. You are not always what we think you eat: selective assimilation across multiple whole-stream isotopic tracer studies

    Science.gov (United States)

    W. K. Dodds; S. M. Collins; S. K. Hamilton; J. L. Tank; S. Johnson; J. R. Webster; K. S. Simon; M. R. Whiles; H. M. Rantala; W. H. McDowell; S. D. Peterson; T. Riis; C. L. Crenshaw; S. A. Thomas; P. B. Kristensen; B. M. Cheever; A. S. Flecker; N. A. Griffiths; T. Crowl; E. J. Rosi-Marshall; R. El-Sabaawi; E. Martí

    2014-01-01

    Analyses of 21 15N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33–50% of the N...

  4. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer

    International Nuclear Information System (INIS)

    Di Tullo, Pamela; Pannier, Florence; Thiry, Yves; Le Hécho, Isabelle; Bueno, Maïté

    2016-01-01

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for "7"7Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas "7"7Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on K_d distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium.

  5. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer

    Energy Technology Data Exchange (ETDEWEB)

    Di Tullo, Pamela, E-mail: pamela.ditullo@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Pannier, Florence, E-mail: florence.pannier@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Thiry, Yves, E-mail: yves.thiry@andra.fr [Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Le Hécho, Isabelle, E-mail: isabelle.lehecho@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Bueno, Maïté, E-mail: maite.bueno@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France)

    2016-08-15

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for {sup 77}Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas {sup 77}Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on K{sub d} distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium.

  6. Study on hydrogen transfer in coal liquefaction by tritium and carbon-14 tracers

    International Nuclear Information System (INIS)

    Nitoh, Osamu; Kabe, Toshiaki; Kabe, Yaeko.

    1985-01-01

    For the analysis of mechanism of hydrogenation and cracking of coal, the liquefaction of Taiheiyo coal using tritium labeled gaseous hydrogen and tritium labeled tetralin with small amounts of carbon-14 labeled naphthalene has been studied. Taiheiyo coal(25g) was thermally decomposed in tetralin or naphthalene solvent(75g) at 400--440 0 C under the initial hydrogen pressure of 5.9MPa for 30min with Ni-Mo-Al 2 O 3 catalyst(0--5g). The reaction mixture in an autoclave was separated by filtration, distillation and solvent extraction. Produced gas, oils and the solvent were analyzed by gas chromatography. The tritium and carbon-14 contents of separated reaction products were measured with a liquid scintilation counter to study the hydrogen transfer mechanism. The distribution of reaction products and the amount of hydrogen transfer from gas or solvent to the products were also determined. In hydrogen donor solvent such as tetralin, the coal liquefaction yield was independent from the catalyst, but the catalyst was effective in hydrocracking of preasphaltene and asphaltene. In naphthalene solvent, the coal liquefaction reaction hardly occured in the absence of the catalyst, because hydrogen transfer from both the solvent and gaseous hydrogen was scarce. Tritium distribution in the reaction products showed that complicated hydrogen exchange reactions between gaseous hydrogen, coal liquids and solvent came out by the presence of coal liquids and catalyst. The very small amounts of carbon-14 transferred to the liquefaction products showed that carbon exchange or transfer between solvent and coal did not take place. (author)

  7. Tracer filamentation at an unstable ocean front

    Science.gov (United States)

    Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

    2017-11-01

    A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

  8. Studies on photosynthate distribution and root exudates of cinesische by 14C tracer technique

    International Nuclear Information System (INIS)

    Chen Junwei; Ni Zhuru; Liu Zhihong; Fu Zhijian

    1994-01-01

    Cinesische (Cunninghamia sinesis R. Br.) plants grown in nutrient solution were exposed to 14 CO 2 for 24 hours to study the photosynthate distribution and root exudates. One day after feeding 14 CO 2 , the majority of 14 C assimilate was remained in leaves, only 27.38% of 14 C assimilate was translocated into new shoots, main branches, lateral branches and roots. 3 days after feeding 14 CO 2 , the distribution rate of 14 C photosynthate in leaves was still the highest, but the percentage decreased and it correspondingly increased in other plant parts. 22 days after feeding 14 CO 2 , the distribution rate in new shoots became the highest, roots ranked the second, main branches were the third, leaves and lateral branches were the lowest. The photosynthate in the root could rapidly convert into root exudates. The amount of root exudates reached a peak after 4 days of feeding 14 CO 2 , afterward the amount of 14 C root exudates decreased rapidly. The amount of sugar was the highest among all kinds of root exudates, the amount of organic acid was the second, the content of amino acid was much lower than that of the other two root exudates

  9. Organotin persistence in contaminated marine sediments and porewaters: In situ degradation study using species-specific stable isotopic tracers

    Energy Technology Data Exchange (ETDEWEB)

    Furdek, Martina; Mikac, Nevenka [Division for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, Zagreb (Croatia); Bueno, Maite; Tessier, Emmanuel; Cavalheiro, Joana [Laboratoire de Chimie Analytique Bio-inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l’Environnement et les Matériaux, CNRS UMR 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau Pyrénées, 2, Av. P. Angot, 64053 Pau Cedex 9 (France); Monperrus, Mathilde, E-mail: mathilde.monperrus@univ-pau.fr [Laboratoire de Chimie Analytique Bio-inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l’Environnement et les Matériaux, CNRS UMR 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau Pyrénées, 2, Av. P. Angot, 64053 Pau Cedex 9 (France)

    2016-04-15

    Highlights: • Limiting step in OTC degradation in sediments is their desorption into porewater. • TBT persistence in contaminated sediments increases in sediments rich in organic matter. • DBT does not accumulate in sediments as degradation product of TBT. • TBT and DBT degradation in porewaters occurs with half-lives from 2.9 to 9.2 days. • PhTs degradation is slower than BuTs degradation in oxic porewaters. - Abstract: This paper provides a comprehensive study of the persistence of butyltins and phenyltins in contaminated marine sediments and presents the first data on their degradation potentials in porewaters. The study’s aim was to explain the different degradation efficiencies of organotin compounds (OTC) in contaminated sediments. The transformation processes of OTC in sediments and porewaters were investigated in a field experiment using species-specific, isotopically enriched organotin tracers. Sediment characteristics (organic carbon content and grain size) were determined to elucidate their influence on the degradation processes. The results of this study strongly suggest that a limiting step in OTC degradation in marine sediments is their desorption into porewaters because their degradation in porewaters occurs notably fast with half-lives of 9.2 days for tributyltin (TBT) in oxic porewaters and 2.9 ± 0.1 and 9.1 ± 0.9 days for dibutyltin (DBT) in oxic and anoxic porewaters, respectively. By controlling the desorption process, organic matter influences the TBT degradation efficiency and consequently defines its persistence in contaminated sediments, which thus increases in sediments rich in organic matter.

  10. Organotin persistence in contaminated marine sediments and porewaters: In situ degradation study using species-specific stable isotopic tracers

    International Nuclear Information System (INIS)

    Furdek, Martina; Mikac, Nevenka; Bueno, Maite; Tessier, Emmanuel; Cavalheiro, Joana; Monperrus, Mathilde

    2016-01-01

    Highlights: • Limiting step in OTC degradation in sediments is their desorption into porewater. • TBT persistence in contaminated sediments increases in sediments rich in organic matter. • DBT does not accumulate in sediments as degradation product of TBT. • TBT and DBT degradation in porewaters occurs with half-lives from 2.9 to 9.2 days. • PhTs degradation is slower than BuTs degradation in oxic porewaters. - Abstract: This paper provides a comprehensive study of the persistence of butyltins and phenyltins in contaminated marine sediments and presents the first data on their degradation potentials in porewaters. The study’s aim was to explain the different degradation efficiencies of organotin compounds (OTC) in contaminated sediments. The transformation processes of OTC in sediments and porewaters were investigated in a field experiment using species-specific, isotopically enriched organotin tracers. Sediment characteristics (organic carbon content and grain size) were determined to elucidate their influence on the degradation processes. The results of this study strongly suggest that a limiting step in OTC degradation in marine sediments is their desorption into porewaters because their degradation in porewaters occurs notably fast with half-lives of 9.2 days for tributyltin (TBT) in oxic porewaters and 2.9 ± 0.1 and 9.1 ± 0.9 days for dibutyltin (DBT) in oxic and anoxic porewaters, respectively. By controlling the desorption process, organic matter influences the TBT degradation efficiency and consequently defines its persistence in contaminated sediments, which thus increases in sediments rich in organic matter.

  11. Electron microscopic studies on odontoblasts using 45Ca as the tracer

    International Nuclear Information System (INIS)

    Okamoto, Eiji

    1980-01-01

    In order to study the relationship between odontoblasts and inorganic salts, odontoblasts of 10-day old rats' incisions and molars were used. The animals were sacrificed 15 minutes, 30 minutes, 1 hour or 2 hours after 45 Ca administration to obtain the specimen. The specimens were processed for electron microscopic autoradiography. 15 minutes after 45 Ca administration, silver grains indicated 45 Ca uptake was already noted within the cells. 45 Ca was localized in the mitochondria, Golgi area, rough surfaced endoplasmic reticulum and partially within the karyoplasm. After 30 minutes' administration, the number of silver grains were generally increased as compared with the findings obtained after 15 minutes' administration. The localization was similar with those after 15 minutes' administration but some were found in the ribosomes and smooth surfaced endoplasmic reticulum with numerous silver grains within small vesicles derived from the Golgi apparatus as well. A movement of 45 Ca from the protruding part to the stroma was also noted. 1 hour after the administration, the number of silver grains were generally decreased, with a more pronounced movement towards stroma from the protruding part. The marked movement of silver grains was obtained onto the collagen fibers in the stroma. In the mitochondria, however, considerable number of silver grains were still seen. In this section, on the other hand, numerous silver grains were seen in the intercellular space, in addition to the pathway of intracellular route, indicating the Ca shift from outside of the cells. After 2 hours' 45 Ca administration, the tendency towards the decrease of the silver grains became more remarkable, the movement of 45 Ca via the extracellular pathway described above was also frequently found. (author)

  12. Nuclear heart function diagnostics. Studies during the first tracer passage and on the distribution equilibrium

    International Nuclear Information System (INIS)

    Feistel, H.

    1982-01-01

    The author attempted to establish a method of evaluation for gated blood pool scintiscanning. The necessary hardware for this purpose was installed, and a method of evaluation for the image sequences was developed on the basis of the medicine-specific GAMMA-11 routines. In addition, the inflow phase directly after the injection was observed. Two different images were possible, i.e. left-oblique in 45 0 projection or right-oblique in 30 0 projection. The findings were evaluated by an analysis of the cyclic heart action and by a quantitative determination of global parameters of the heart function, e.g. ejection fraction, rate of volume change etc. The regional myocardial motility can be assessed after orthogonal transformation into an amplitude image and a phase image. A new type of transformation is presented, i.e. the ''quantized sine/cosine transformation'' which allows fast calculation without a floating-point processor. States of akinesia and dyskinesia are well imaged. The first-passage technique gives a general picture of the cardiopulmonary situation. The algorithms described were used in 26 cardiac examinations of 24 patients. Ten further patients were examined by angiography. Except for one case of hypokinesia of the back wall, all disturbances of motility were detected. The angiographic and scintigraphic ejection fractions are correlated with r = 0.98, the rates between first-pass and gated study with r = 0.92, and the rates between 12-picture and 48-picture sequences with r = 0.98. (orig./MG) [de

  13. Tracer attenuation in groundwater

    Science.gov (United States)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  14. Suitability of tracers

    International Nuclear Information System (INIS)

    Klotz, D.

    1999-01-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other [de

  15. New radioactive tracers can help find cause of jaundice

    International Nuclear Information System (INIS)

    Carrard, G.

    1987-01-01

    Radioactive tracers for the investigation of a condition known as persistent jaundice of the newborn, have been designed, prepared and tested at ANSTO. The tracers are chemical compounds of the radioactive elements gallium-67 and indium-111. They given lower radiation doses than the conventional radioactive tracer, iodine-131, used in these studies

  16. Study of weathering velocity of rocks with uranium as a natural tracer. Application to two drainage basins of the north-east of Brazil

    International Nuclear Information System (INIS)

    Costa Pinto Moreira Nordemann, L.M. da.

    1977-01-01

    Study on rock weathering rate, i.e. rock-soil interface formation, by measuring the elements dissolved in river waters. These elements are used as natural tracers. This work has been carried out in the drainage basin of Preto and Salgado Rivers, in Brazil. Conventional elements, sodium, potassium, calcium and magnesium have been utilized first and all dissolved salts have been used as natural tracers to allow comparison with other scientific works. Then, uranium has been used because it is not found in rain waters so that corrections are not necessary and because its abundance can be measured by α and γ spectrometry, and the 234 U/ 238 U ratio obtained, 234 U being more rapidly dissolved during weathering. Another reason is that no interaction occurs between uranium and the biomass. It is then possible to find a geochemical balance for this area [fr

  17. A comparative study on androgen metabolism in three invertebrate species.

    Science.gov (United States)

    Janer, G; LeBlanc, G A; Porte, C

    2005-09-15

    A comparative approach was taken in this study to evaluate androgen (androstenedione and testosterone) metabolism in three invertebrate species: the gastropod Marisa cornuarietis, the amphipod Hyalella azteca, and the echinoderm Paracentrotus lividus. The existence of 17beta/3beta-hydroxysteroid dehydrogenase (HSD) and 5alpha-reductase catalyzed reactions was demonstrated in all three species. Androstenedione was primarily converted to 5alpha-androstanedione in M. cornuarietis, while it was primarily metabolized to testosterone in P. lividus and H. azteca. In addition, and consistent with vertebrate findings, tissue specific pathways and sexual dimorphism in androgen metabolism were observed. Namely, testosterone was metabolized to dihydrotestosterone in P. lividus gonads (via 5alpha-reductase), and metabolized to 4-androstene-3beta,17beta-diol in the digestive tube (via 3beta-hydroxysteroid dehydrogenase). Furthermore, the synthesis of 17beta-reduced metabolites of androstenedione (testosterone and dihydrotestosterone) was 3- to 4-fold higher in males of M. cornuarietis than in females. Organotin compounds, which have been shown to interfere with some aspects of androgen metabolism, had no major effect on testosterone metabolism in any of the three species. Fenarimol enhanced 5alpha-reductase-mediated catalysis in gonads of P. lividus. Overall, results demonstrate the ubiquity of some androgen biotransformation processes in invertebrates and reveals interphyla differences in androgen metabolic pathways, and different sensitivity of these pathways to some xenobiotics.

  18. The use of tracers in the study of the ionic permeability of the nerve; Utilisation des indicateurs nucleaires dans l'etude de la permeabilite ionique du nerf

    Energy Technology Data Exchange (ETDEWEB)

    Guinnebault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The use of the radioactive tracers {sup 24}Na and {sup 42}K, and the electrophysiological fine study carried out on the plant Cephalopods nervous cells have made it possible, during ten years, to study the relationships between the electrical phenomena observed during the propagation of the nervous impulse and the ionic movements which occur at the cell membrane between the intra- and extra-cellular media. In the state of rest, the nerve fibres present a certain permeability towards sodium and potassium, a permeability which allows the renewal, from the extra-cellular medium, of the cations contained in the cytoplasm. At the moment of the passage of the nervous impulse, it is possible to demonstrate a temporary increase in the permeability towards the sodium which causes the entry of Na{sup +} ions into the nerve fibre, whilst, a few milliseconds later, the increase in the potassium permeability causes the departure of an equivalent quantity of K{sup +} ions. A recovery phase follows the passage of the nervous impulse, during which the original ionic conditions are re-established. If the potassium movements can be considered as passive, the expulsion of Na{sup +} requires, on the part of the cell, the use of a part of the metabolic energy. (author) [French] L'utilisation des indicateurs radioactifs {sup 24}Na et {sup 42}K, et l'etude electrophysiologique fine realisee sur des cellules nerveuses geantes de Cephalopodes a permis, depuis une dizaine d'annees, d'etudier les rapports entre les phenomenes electriques observes lors de la propagation de l'influx nerveux et les mouvements ioniques qui s'effectuent au niveau de la membrane cellulaire entre milieux intracellulaire et extracellulaire. A l'etat de repos, les fibres nerveuses possedent pour le sodium et le potassium, une permeabilite qui permet le renouvellement, a partir du milieu extracellulaire des cations contenus dans le cytoplasme. Au moment du passage de l'influx nerveux, on peut mettre en evidence une

  19. Application of the multi-rate diffusion approach in tracer test studies at Aespoe HRL. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, R. [Oregon State Univ., Corvallis, OR (United States). Dept. of Geosciences

    1999-11-01

    This report summarizes an investigation into heterogeneous diffusivity and associated parameters within granitic rocks at the Aespoe Hard Rock Laboratory (HRL). Our tasks for this investigation were: (1) to assess the potential for either anomalous or multi-rate diffusion within Aespoe rocks; (2) to evaluate existing data relating to anomalous and multi-rate diffusion within Aespoe rocks; (3) to perform scoping calculations in support of a Long Term Diffusion Experiment (LTDE) design; and (4) to begin developing a mathematical and computer model for solute advection in the presence of anomalous matrix diffusion. In addition to carrying out these tasks, we also report on (5) the late-time behavior of breakthrough curves. First, in regard to the potential for anomalous and multi-rate diffusion and analyses of existing data, we find that (1) in a literature review of 100 column experiments in various types of rock and sediment, rate coefficients decrease with experimental observation time. This is precisely what would be expected of both multi-rate and anomalous diffusion. (2) Three sets of through-diffusion experiments in Fenno-Scandian granitic rock found decreasing effective diffusivity, D{sub e}, with sample length, while one set did not. (3) Based on diffusivity and sorption data, and speculation on matrix block size variability, the total variability of D{sub a}/a{sup 2} may reasonably be expected to exceed 4 orders of magnitude. (4) Analyses of two-well tracer data completed to date are ambiguous with respect to multi-rate diffusion. Analyses of TRUE data are currently underway and may support multi-rate diffusion. Second, in regard to the potential consequences of multi-rate and anomalous diffusion on nuclear waste disposal, we found the following key points: (1) No single value of diffusivity can represent the diffusion process at all time- or length-scales if diffusion is truly anomalous, while a single value of diffusivity will represent diffusion

  20. Application of the multi-rate diffusion approach in tracer test studies at Aespoe HRL. Final report

    International Nuclear Information System (INIS)

    Haggerty, R.

    1999-11-01

    This report summarizes an investigation into heterogeneous diffusivity and associated parameters within granitic rocks at the Aespoe Hard Rock Laboratory (HRL). Our tasks for this investigation were: (1) to assess the potential for either anomalous or multi-rate diffusion within Aespoe rocks; (2) to evaluate existing data relating to anomalous and multi-rate diffusion within Aespoe rocks; (3) to perform scoping calculations in support of a Long Term Diffusion Experiment (LTDE) design; and (4) to begin developing a mathematical and computer model for solute advection in the presence of anomalous matrix diffusion. In addition to carrying out these tasks, we also report on (5) the late-time behavior of breakthrough curves. First, in regard to the potential for anomalous and multi-rate diffusion and analyses of existing data, we find that (1) in a literature review of 100 column experiments in various types of rock and sediment, rate coefficients decrease with experimental observation time. This is precisely what would be expected of both multi-rate and anomalous diffusion. (2) Three sets of through-diffusion experiments in Fenno-Scandian granitic rock found decreasing effective diffusivity, D e , with sample length, while one set did not. (3) Based on diffusivity and sorption data, and speculation on matrix block size variability, the total variability of D a /a 2 may reasonably be expected to exceed 4 orders of magnitude. (4) Analyses of two-well tracer data completed to date are ambiguous with respect to multi-rate diffusion. Analyses of TRUE data are currently underway and may support multi-rate diffusion. Second, in regard to the potential consequences of multi-rate and anomalous diffusion on nuclear waste disposal, we found the following key points: (1) No single value of diffusivity can represent the diffusion process at all time- or length-scales if diffusion is truly anomalous, while a single value of diffusivity will represent diffusion adequately for some

  1. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  2. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  3. Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations; Untersuchungen zur Darstellung traegerarm 73,75Se-markierter Tracer fuer in vivo Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Helfer, Andreas

    2013-04-03

    studies with respect to tracer application with PET. First in vitro distributions studies with slices of rat brain were already performed by autoradiography.

  4. Tracer techniques in microelectronics

    International Nuclear Information System (INIS)

    Flachowsky, J.; Freyer, K.

    1981-01-01

    Tracer technique and neutron activation analysis are capable of measuring impurities in semiconductor material or on the semiconductor surface in a very low concentration range. The methods, combined with autoradiography, are also suitable to determine dopant distributions in silicon. However, both techniques suffer from certain inherent experimental difficulties and/or limitations which are discussed. Methods of tracer technique practicable in the semiconductor field are described. (author)

  5. The development of in vivo tracer methods to obtain new information about human disease: a study of the hallucinating brain

    International Nuclear Information System (INIS)

    Jones, T.; Silbersweig, D.A.; Stern, E.; Schnorr, L.; Seaward, J.; Clark, J.C.; Lammertsma, A.A.; Grootoonk, S.

    1996-01-01

    An outline is provided of the development of methodological strategies to address the question of focal cerebral activation during hallucinations in schizophrenic patients. In so doing, the innovation and diligence required to tailor in vivo tracer procedures to specific clinical research issues are highlighted. Attention is drawn to the complexity of methodological advances and the way in which they are based upon close scientific and technical collaboration between clinical scientists, and non-clinical scientists and research support staff. (orig.). With 1 fig

  6. Study of preparation and survey of radioisotopes tracer applications of gold nanoparticles in the multi-phase industrial processes

    International Nuclear Information System (INIS)

    Huynh Thai Kim Ngan; Trinh Cong Son; Duong Thi Bich Chi; Tran Tri Hai; Nguyen Huu Quang; Bui Trong Duy; Le Trong Nghia; Ngo Duc Tin

    2014-01-01

    Gold nanoparticles (AuNPs) were prepared by Turkevich and Brust method. The labeled gold in liquids is the colloidal form with nano size particle of gold. This particles is of high dispersity in the liquid phase that makes them a good physical tracer. The stability and dissolve of AuNPs in solvents such as water, toluene are hereafter discussed. The size of AuNPs was determined through UV-Visible spectroscopy (UV-Vis) and transmission electron microscope (TEM). (author)

  7. Methodology Measuring Rare Earth Elements in High TDS Reservoir Brines Application as Natural Tracers in CCUS Studies

    Science.gov (United States)

    Smith, W.; Mcling, T. L.; Smith, R. W.; Neupane, H.

    2013-12-01

    In recent years rare earth elements (REE) have been demonstrated to be useful natural tracers for geochemical processes in aqueous environments. The application of REE's to carbon dioxide utilization and storage (CCUS) could provide researchers with a sensitive, inexpensive tool for tracking the movement of CO2 and displaced formation brines. By definition, geologic reservoirs that have been deemed suitable for carbon capture and storage contain formation brine with total dissolved solids (TDS) greater than 10,000 ppm and often these formation brines exceed 75,000 ppm TDS. This high TDS water makes it very difficult to measure REE, which typically occur at part per trillion concentrations. Critical to the use of REE for CCUS studies is the development of a procedure, which allows for the pre-concentration of REE's across a wide range of water quality. Additionally, due to the large number of samples that will need analysis, any developed procedure must be inexpensive, reproducible, and quick to implement. As part of the Big Sky Carbon Sequestration Project the INL's Center for Advance Energy Studies is developing REE pre-concentration procedures based on methods reported in the literature. While there are many REE pre-concentration procedures in the literature, our tests have shown these methods have difficulty at TDS greater than seawater (roughly 35,000 ppm TDS). Therefore, the ability to quantitatively measure REE's in formation brines with very high TDS has required the modification of an already developed procedure. After careful consideration and testing we selected methods modified after those described by Kingston et al., 1978 and Strachan et al., 1989 utilizing chelating media for very high TDS waters and ion-exchange media as detailed by Crock et al., 1984; Robinson et al., 1985; and Stetzenbach et al., 1994 for low TDS (tested in our laboratory and have proven effective in greatly reducing interfering monovalent and divalent cation concentrations (e

  8. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  9. Tracer-aided studies on the fate and effects of sulphur dioxide in Spinacia oleracea L. and Triticum vulgare. Part of a coordinated programme on isotopic-tracer-aided studies of atmospheric sulphur pollutant - plant interactions

    International Nuclear Information System (INIS)

    Plesnicar, M.

    1982-06-01

    Wheat, Triticum vulgare and spinach, Spinacia oleracea plants were exposed to two different concentrations of 35 SO 2 - released by lactic acid from Na 2 35 SO 3 - for 45 minutes, and distribution of radioactivity was studied in leaves, stem and roots. After 24 hours, the specific activity of the leaves of both plants was reduced while that of the roots was increased, suggesting 35 S translocation from leaves to roots. Translocation to the stem and roots of 35 S products was much higher in wheat than in spinach. In leaves of both plant species, ethanol-soluble products were much higher than the ethanol-insoluble fraction during the first 6 hours of exposure. The ethanol-soluble fraction contained sulphate, sulphite and unidentified material. The study suggests that SO 2 is metabolized in preference to endogenous S, that the wheat plant is more susceptible to SO 2 , and that tolerance is related to the capacity of converting SO 2 to sulphate and reducing its further conversion. Uptake of 35 SO 2 by young and old wheat and spinach plants was studied with a view to determining susceptibility to SO 2 exposure as a function of the developmental stage of the plant. In wheat, young plants metabolize endogenous sulphur in preference to absorbed SO 2 while older plants are active in converting absorbed sulphur into organic (ethanol-insoluble) form. In spinach, young plants are more active in transporting 35 S products from leaves to roots and older plants show higher incorporation percentage of 35 S into the organic fraction of leaves. Uptake of 1- 14 C-acetate by lipids of leaf discs from spinach and wheat was investigated in normal and SO 2 -stressed plants. The incorporation of radioacetate into lipids of leaf tissues of both plants was strongly inhibited in SO0 plants. Also U- 14 C-lysine incorporation into proteins of leaf tissue was significantly inhibited by 0.2-2.0 ppm aqueous SO 2

  10. 99mTcO(BAT-NI), a novel nitroimidazole tracer: in vivo uptake studies in ischaemic myocardium

    International Nuclear Information System (INIS)

    Hoffend, J.; Linke, G.; Mohammed, A.; Haberkorn, U.; Tiefenbacher, C.P.; Eisenhut, M.

    2003-01-01

    Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or 99m Tc have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates 99m TcO(BAT-NI), a new 99m Tc complex comprising the nitroimidazole ligand, 2,10-dimercapto-2, 10-dimethyl-4, 8-diaza-6-[4-(2-nitroimidazolyl)butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [ 99m TcO(BAT-I)], (b) the 2-nitroimidazole functionality was replaced by a Br atom [ 99m TcO(BAT-Br)] and (c) the 99m TcO(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ( 125 IP-NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for 99m TcO(BAT-NI), 99m TcO(BAT-I) and 99m TcO(BAT-Br), respectively. In contrast, 125 IP-NI was not preferentially taken up by ischaemic myocardium. Accumulation of 99m TcO(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of 99m TcO(BAT-NI) in ischaemic tissue and an I/N of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for 99m TcO(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of 99m TcO(BAT-NI) in ischaemic myocardium does not depend on the nitroimidazole moiety but is intrinsic to the BAT complex

  11. Brain glucose metabolism during hypoglycemia in type 1 diabetes: insights from functional and metabolic neuroimaging studies.

    Science.gov (United States)

    Rooijackers, Hanne M M; Wiegers, Evita C; Tack, Cees J; van der Graaf, Marinette; de Galan, Bastiaan E

    2016-02-01

    Hypoglycemia is the most frequent complication of insulin therapy in patients with type 1 diabetes. Since the brain is reliant on circulating glucose as its main source of energy, hypoglycemia poses a threat for normal brain function. Paradoxically, although hypoglycemia commonly induces immediate decline in cognitive function, long-lasting changes in brain structure and cognitive function are uncommon in patients with type 1 diabetes. In fact, recurrent hypoglycemia initiates a process of habituation that suppresses hormonal responses to and impairs awareness of subsequent hypoglycemia, which has been attributed to adaptations in the brain. These observations sparked great scientific interest into the brain's handling of glucose during (recurrent) hypoglycemia. Various neuroimaging techniques have been employed to study brain (glucose) metabolism, including PET, fMRI, MRS and ASL. This review discusses what is currently known about cerebral metabolism during hypoglycemia, and how findings obtained by functional and metabolic neuroimaging techniques contributed to this knowledge.

  12. Applications of deuterium labeling in studies of drug metabolism: metabolism of trideuteroaniline mustard

    International Nuclear Information System (INIS)

    Cox, P.J.; Farmer, P.B.; Foster, A.B.; Jarman, M.

    1977-01-01

    In a continuation of a study of aniline mustard, the metabolism of 2,4,6-trideuteroaniline mustard [N-N-di-(2-chloroethyl)-2,4,6-trideuteroaniline] was investigated. Measurements of the ratios of deuterated to nondeuterated species in p-hydroxyaniline mustard and N-(2-chloroethyl)-4-hydroxyaniline isolated following in vitro metabolism of a mixture of aniline mustard and aniline mustard-d 3 enabled a determination both of the kinetic isotope effect and of the extents of NIH shifts and indicated the probable metabolite sequence

  13. Tracer techniques in food industry

    International Nuclear Information System (INIS)

    Pertsovskij, E.S.; Sakharov, Eh.V.; Dolinin, V.A.

    1980-01-01

    The appicability of radioactive tracer techniques to process control in food industry are considered. Investigations in the field of food industry carried out using the above method are classified. The 1 class included investigations with preliminary preparation of a radioactive indicator and its following introduction in the system studied. The 2 class includes investigations based on the introduction in the system studied of a non-active indicator which is activated in a neutron flux being in samples selected in or after the process investigated. The 3 class includes studies based on investigations of natural radioactivity of certain nuclides in food stuff. The application of tracer techniques to the above classes of investigations in various fields of food industry and the equipment applied are considered in detail [ru

  14. Isotopic studies of urea metabolism in rabbits

    Science.gov (United States)

    Regoeczi, E.; Irons, L.; Koj, A.; McFarlane, A. S.

    1965-01-01

    1. The half-life of [15N]urea was found to be significantly longer than that of [14C]urea injected at the same time, the differences being due to endogenous catabolism of urea, which is accompanied by little or no reutilization of 14C but is approx. 20% for 15N. [15N]Urea therefore appears to be valueless as an indicator of nitrogen metabolism unless the extents of endogenous catabolism of urea and of fractional reutilization of 15N can be separately estimated. 2. Though measurements of the radioactivity of expired 14CO2 confirmed the existence of considerable urea catabolism these could not be used for quantitative assessments. 3. Alternative graphical methods based on [14C]urea specific activities in plasma and urine samples were used to calculate the fraction of urea production that is excreted. Values by the two methods were in good agreement and showed that some animals excrete less than half the urea that they produce. 4. Specific activity differences between simultaneous samples of urinary and plasma urea reflect the presence of a pool of urea in the kidney that is not in equilibrium with the body urea pool. Calculations indicate the presence of urea in the kidney that in some cases may represent as much as 15% of the body pool, and in two animals in which post-mortem renal analyses were performed the masses of urea found agreed closely with the calculated values. 5. A model for urea metabolism is proposed that includes this pool in the excretory pathway. The related theory is shown to be adequate to explain the shape of the specific activity curves of urinary urea from the time of injection and the constant delay of the specific activity of urinary urea, relative to that of plasma urea, that is observed after a short preliminary equilibration period. 6. The body urea pool was calculated from the activity retained at 1·5hr. by excluding renal activity and the corrected specific activity of plasma urea at the same time. The urea pool was calculated to be

  15. Vinasse labelling with sup(15)N: use in mineral plants fertilization studies and the potential of the isotopic technique in studies of fermentative nitrogen metabolism of wine

    International Nuclear Information System (INIS)

    Lara C, W.A.; Trivelin, P.C.O.; Basso, L.C.

    1991-01-01

    A methodology for vinasse sup(15)N enrichment was developed under laboratory conditions through a fermentative process. Direct addition of sup(15)N-(NH sub(4)) sub(2)SO sub(4) 90.39 atoms % to the vintage tub (FESA procedure) was compared to the use of a previously enrichment sup(15)N yeast (FELE procedure) by the addition of the label to the multiplicative medium. The mean metabolic recovery of the tracer from the vinasse after fermentation was 4.2 and 11.1% per cycle and accumulated recovery was 3.4 and 33.3%, respectively for the FESA and FELE procedures. The potential of the use of sup(15)N label in studies of fermentative nitrogen metabolism is illustrated by the quantification of sup(15)N distribution among recycled yeast and wine. (author)

  16. Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-08-01

    This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

  17. Genetic and environmental relationships of metabolic and weight phenotypes to metabolic syndrome and diabetes: the healthy twin study.

    Science.gov (United States)

    Song, Yun-Mi; Sung, Joohon; Lee, Kayoung

    2015-02-01

    We aimed to examine the relationships, including genetic and environmental correlations, between metabolic and weight phenotypes and factors related to diabetes and metabolic syndrome. Participants of the Healthy Twin Study without diabetes (n=2687; 895 monozygotic and 204 dizygotic twins, and 1588 nontwin family members; mean age, 42.5±13.1 years) were stratified according to body mass index (BMI) (metabolic syndrome categories at baseline. The metabolic traits, namely diabetes and metabolic syndrome, metabolic syndrome components, glycated hemoglobin (HbA1c) level, and homeostasis model assessment of insulin resistance (HOMA-IR), were assessed after 2.5±2.1 years. In a multivariate-adjusted model, those who had metabolic syndrome or overweight phenotypes at baseline were more likely to have higher HbA1C and HOMA-IR levels and abnormal metabolic syndrome components at follow-up as compared to the metabolically healthy normal weight subgroup. The incidence of diabetes was 4.4-fold higher in the metabolically unhealthy but normal weight individuals and 3.3-fold higher in the metabolically unhealthy and overweight individuals as compared with the metabolically healthy normal weight individuals. The heritability of the metabolic syndrome/weight phenotypes was 0.40±0.03. Significant genetic and environmental correlations were observed between the metabolic syndrome/weight phenotypes at baseline and the metabolic traits at follow-up, except for incident diabetes, which only had a significant common genetic sharing with the baseline phenotypes. The genetic and environmental relationships between the metabolic and weight phenotypes at baseline and the metabolic traits at follow-up suggest pleiotropic genetic mechanisms and the crucial role of lifestyle and behavioral factors.

  18. Nitrate movement and removal along a shallow groundwater flow path in a riparian wetland within a sheep-grazed pastoral catchment : result of a tracer study

    International Nuclear Information System (INIS)

    Burns, D.A.; Nguyen, L.

    2002-01-01

    The movement and removal of nitrate (NO 3 ) along a groundwater flow path within a riparian wetland was investigated during a 24-day period in late autumn-early winter, using a lithium bromide (LiBr)-potassium nitrate (KNO 3 ) tracer solution containing 19 200 mg/litre as Br - and 193.8 mg/litre as NO 3 -N. The tracer solution was added as an instantaneous dose of tracer solution at a depth of 10-20 cm to four injection wells in two 1 m 2 plots within a sheep-grazed pastoral catchment at the Whatawhata Agricultural Research Centre near Hamilton, New Zealand. Bromide and NO 3- N concentrations were measured periodically in: (1) wetland groundwater samples from piezometers installed at 15 and 30 cm depths and located at 30, 60, and 100 cm down gradient from the injection wells; and (2) surface flow samples. Peak concentrations of 50-250 mg/litre of Br - and 0.2-1.1 mg/litre of NO 3 -N were reached within 1-2 days after application at most piezometers. Nitrate concentrations decreased thereafter more sharply than did those of Br - , resulting in decreased NO 3 -N/Br - ratios from Days 2 through 7. More than 99% of groundwater samples collected after the tracer application had NO 3 -N/Br - less than the value in the tracer solution indicating removal of NO 3 -N during transport. Mass flux estimates indicated removal of >90% of added NO 3 -N along the 100 cm flow path from the injection, with essentially all of the NO 3 - removed within the first 30 cm of transport. On Days 10 and 24, just after rain events, surface flow from the experimental plots had greatly elevated NO 3 -N concentrations that were not accompanied by correspondingly elevated Br - concentrations, indicating that NO 3 -N originating from the surrounding catchment was transported over the wetland surface with little penetration or mixing with wetland groundwater. Despite a significant capacity for NO 3 -N removal from shallow groundwater equivalent to an annualised value of 50 kg/ha in these wetland

  19. Statistically Based Morphodynamic Modeling of Tracer Slowdown

    Science.gov (United States)

    Borhani, S.; Ghasemi, A.; Hill, K. M.; Viparelli, E.

    2017-12-01

    Tracer particles are used to study bedload transport in gravel-bed rivers. One of the advantages associated with using of tracer particles is that they allow for direct measures of the entrainment rates and their size distributions. The main issue in large scale studies with tracer particles is the difference between tracer stone short term and long term behavior. This difference is due to the fact that particles undergo vertical mixing or move to less active locations such as bars or even floodplains. For these reasons the average virtual velocity of tracer particle decreases in time, i.e. the tracer slowdown. In summary, tracer slowdown can have a significant impact on the estimation of bedload transport rate or long term dispersal of contaminated sediment. The vast majority of the morphodynamic models that account for the non-uniformity of the bed material (tracer and not tracer, in this case) are based on a discrete description of the alluvial deposit. The deposit is divided in two different regions; the active layer and the substrate. The active layer is a thin layer in the topmost part of the deposit whose particles can interact with the bed material transport. The substrate is the part of the deposit below the active layer. Due to the discrete representation of the alluvial deposit, active layer models are not able to reproduce tracer slowdown. In this study we try to model the slowdown of tracer particles with the continuous Parker-Paola-Leclair morphodynamic framework. This continuous, i.e. not layer-based, framework is based on a stochastic description of the temporal variation of bed surface elevation, and of the elevation specific particle entrainment and deposition. Particle entrainment rates are computed as a function of the flow and sediment characteristics, while particle deposition is estimated with a step length formulation. Here we present one of the first implementation of the continuum framework at laboratory scale, its validation against

  20. Use of geochemical and isotope tracers to assess groundwater dependency of a terrestrial ecosystem: case study from southern Poland

    Science.gov (United States)

    Zurek, Anna J.; Witczak, Stanislaw; Kania, Jaroslaw; Rozanski, Kazimierz; Dulinski, Marek; Wachniew, Przemyslaw

    2015-04-01

    The presented study was aimed at better understanding of the functioning of groundwater dependent terrestrial ecosystem (GDTE) located in the south of Poland. The studied GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Bloto fen). It relies not only on shallow, unconfined aquifer but indirectly also on groundwater originating from the deeper confined aquifer, underlying the Quaternary cover and separated from it by an aquitard of variable thickness. The main objective of the study was to evaluate the contribution of groundwater to the water balance of the studied GDTE and thereby assess the potential risk to this system associated with intense exploitation of the deeper aquifer. The Wielkie Błoto fen area and the adjacent parts of Niepolomice Forest are drained by the Dluga Woda stream with 8.2 km2 of gauged catchment area. Hydrometric measurements, carried out on the Dluga Woda stream over two-year period (August 2011 - August 2013) were supplemented by chemical and isotope analyses of stream water, monitored on monthly basis. Physico-chemical parameters of the stream water (SEC, pH, Na content, Na/Cl molar ratio) and isotope tracers (deuterium, oxygen-18 and tritium) were used to quantify the expected contribution of groundwater seepage from the deeper aquifer to the water balance of the Dluga Woda catchment. The mean transit time of water through the catchment, derived from temporal variations of δ18O and tritium content in the Dluga Woda stream, was in the order of three months. This fast component of the total discharge of Dluga Woda stream is associated surface runoff and groundwater flow paths through the Quaternary cover. The slow component devoid of tritium and probably originated from the deeper Neogene aquifer is equal to approximately 30% of the total discharge. The relationships between the physico-chemical parameters of the stream water and the flow rate of Dluga Woda clearly indicate that the monitored

  1. Impurity transport studies by means of tracer-encapsulated solid pellet injection in neutral beam heated plasmas on LHD

    International Nuclear Information System (INIS)

    Tamura, N; Sudo, S; Khlopenkov, K V; Kato, S; Sergeev, V Yu; Muto, S; Sato, K; Funaba, H; Tanaka, K; Tokuzawa, T; Yamada, I; Narihara, K; Nakamura, Y; Kawahata, K; Ohyabu, N; Motojima, O

    2003-01-01

    The quantitative properties of impurity transport in large helical device (LHD) plasmas heated by neutral beam injection have been investigated by means of tracer-encapsulated solid pellet (TESPEL) injection. In the case of a titanium (Ti) tracer, the behaviour of the emission lines from the highly ionized Ti impurity, Ti Kα(E He-like ∼ 4.7 keV) and Ti XIX (λ = 16.959 nm), has been observed clearly by a soft x-ray pulse height analyzer and a vacuum ultraviolet spectrometer, respectively. A fairly longer decay time of the Ti Kα emission lines is obtained above the value of a line-averaged electron density, 3.0x10 19 m -3 . The dependence of the behaviour of the Ti tracer impurity on the line-averaged electron density below the value of that, 3.5x10 19 m -3 is in qualitative agreement with the characteristics obtained from the observation of the behaviour of an intrinsic metallic impurity in neutral beam heated plasmas on LHD. In order to estimate the properties of the Ti impurity transport quantitatively, the one-dimensional impurity transport code, MIST has been used. As a result of the transport analysis with the MIST code, even an small inward convection should be necessary to account for the experimental results with the value of the line-averaged electron density, 3.5x10 19 m -3 . In order to examine the experimentally obtained transport coefficients, neoclassical analysis with respect to the radial impurity flux has been performed. The inferred rise of the inward convection cannot be explained solely by neoclassical impurity transport. Therefore, in order to account for the inward convection, the effect of a radial electric field and/or some other effect must be taken into account additionally

  2. Potential Use of Tracer Methods, Especially Autoradiography, in the Study of the Relation of Herbicides to Soil Biology

    Energy Technology Data Exchange (ETDEWEB)

    Grossbard, E. [Grassland Research Institute, Hurley, Maidenhead, Berks (United Kingdom)

    1966-05-15

    Several tracer methods, designed originally for the study of general soil processes, are described. Their possible adaptation to investigations of the interaction of herbicides with soil biology (especially the soil microflora) is discussed. Rapid disposal of the herbicide-treated vegetation before replanting (minimal tillage) is essential. In comparing the efficiency of herbicidal destruction of vegetation with conventional ploughing, and also when evaluating the effect of various herbicides on the rate of decay of the treated crops, a method is required to measure the rate of the microbial decomposition of the plant residues. A technique based on autoradiography is described which makes possible the study of the progressive decay of herbage grasses and rye uniformly labelled with carbon-14, placed on the surface of soil and incubated for various periods of time. Photoelectric measurements of the density of images of autoradiographs prepared before the start of the experiment and at intervals during incubation show a statistically significant decrease in density with time of incubation. This progressive loss of carbon is an estimate of the rate of decomposition of the residues. The utilization of breakdown products of herbicides by micro-organisms has been demonstrated in pure culture using labelled herbicides but not directly in the soil. A method based on the stripping film technique demonstrates the incorporation of carbon-14 atoms into the cell material of fungi which decomposed {sup 14}C-labelled plant residues mixed with soil. This technique could be adapted to study the uptake of labelled atoms after the microbial decomposition of radioactive herbicides in the soil. Herbicides inhibit and under,certain conditions may also stimulate the growth of micro-organisms in the soil. The evolution of CO{sub 2} is frequently used as an index of microbial activity. It is, however, also a function of the carbon content of the soil. Soils not treated with herbicides will

  3. Wairakei tracer tests 1983

    International Nuclear Information System (INIS)

    McCabe, W.J.; Barry, B.J.

    1984-05-01

    Tracer tests, with and without, hot water reinjection into WK213 showed returns of tracer iodine-131; in wells in both the Waiora Valley and the eastern end of the field. The effect of reinjection at a rate of 200 cu. m/h was to reduce the arrived time from 15 to 7 days. Increasing the rate of reinjection into WK62 from 30 cu. m/h to 200 cu. m/h seemed to increase the initial velocity of the tracer wave and the distance it moved. However, returns were recorded only in the adjacent wells WK61 and WK63 with a very small, and three days delayed, response in WK43

  4. NMR-Metabolic Methodology in the Study of GM Foods

    Science.gov (United States)

    The 1H NMR methodology used in the study of genetically modified (GM) foodstuff is discussed. The study of transgenic lettuce (Lactuca sativa cv "Luxor") over-expressing the KNAT1 gene from Arabidopsis is presented as a novel study-case. The 1H NMR metabolic profiling was carried out. Twenty-two wat...

  5. Study of lag time of river chenab between marala barrage and khanki headworks using radioactive tracer technique

    International Nuclear Information System (INIS)

    Ahmed, A.; Tariq, J.A.; Ahmad, N.; Iqbal, N.

    2001-05-01

    During the flood season, sometimes discharge peaks in two tributaries of the Indus River System coincide at the point of confluence and their cumulative effect threatens the downstream barrage/headworks. Reasonably accurate lag time (transit time) between different control points in relation to discharge helps mange flood routing more safely. As a part of S tudy of Lag Time of the Indus River Suystem , radioactive tracer experiment was conducted to determine the lag time between Marala Barrage and Khanki Headworks at the river Chenab. Discharge data shows that the maximum flood peak appears in August. In the monsoon period of the year 1999 the floods were low. So the radiotracer experiment was carried out at low discharge of about 538 m/sup 3/ sec/sup-1/ (19000 cusecs). An activity of about 2 Ci of /sup 82/Br radioactive tracer was injected instantaneously in the river at Marala on 1st September 1999 at 0640 hours. Monitoring of radioactivity by scintillation detectors (sodium iodide) was done at Khanki Headworks. The peak value of activity was found on September 2, 1999 at 0005 hours. The lag time was determined as 17 hours and 25 minutes. At this discharge level the river water travelled with the average speed of 3.69 km/hr. (author)

  6. Preliminary evaluation of [1-11C]octanoate as a PET tracer for studying cerebral ischemia. A PET study in rat and canine models of focal cerebral ischemia

    International Nuclear Information System (INIS)

    Kuge, Yuji; Kawashima, Hidefumi; Hashimoto, Tadatoshi

    2000-01-01

    Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the tricarboxylic acid (TCA) cycle after β-oxidation. We speculate that [1- 11 C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1- 11 C]octanoate and compared it with cerebral blood flow (CBF) by using rat and canine models of middle cerebral artery (MCA) occlusion and a high resolution PET. In rats brain distribution of [ 15 O]H 2 O measured 1-2 h and 5-6 h after insult was compared with that of [1- 11 C]octanoate measured 3-4 h after insult. Radioactivity ratios of lesioned to normal hemispheres determined with [ 15 O]H 2 O were lower than those determined with [1- 11 C]octanoate. These results were confirmed by a study on a canine model of MCA-occlusion. Twenty-four hours after insult, CBF decreased in the MCA-territory of the occluded hemisphere, whereas normal or higher accumulation of [1- 11 C]octanoate was observed in the ischemic regions. The uptake of [1- 11 C]octanoate-derived radioactivity therefore increased relative to CBF in the ischemic regions, indicating that [1- 11 C]octanoate provides functional information different from CBF. In conclusion, we found that [1- 11 C]octanoate is a potential radiopharmaceutical for studying the pathophysiology of cerebral ischemia. (author)

  7. Proposal for a coordination research programme (CRP) of the International Atomic Energy Agency (IAEA) on stable isotope tracer techniques for studies on protein-energy interactions

    International Nuclear Information System (INIS)

    Shetty, P.; James, W.P.T.

    1993-01-01

    This Report provides a rationale and justification for the initiation of a Coordinated Research programme to support studies using stable isotopic tracer techniques to address priority areas of human protein-energy interactions with special emphasis on the problems of human nutrition in developing countries. The Report suggests a modus for establishing such a practically oriented Coordinated Research Programme under the aegis of the International Atomic Energy Agency with concrete suggestions for its organization and the identification of probable participants in such a programme. The likely sources of additional funding to sustain such an activity viable for a period of 4 to 5 years are also indicated. 8 refs

  8. 2H, 3H and 18O Tracers used for a preliminary study of groundwaters vulnerability to contaminants in the South-West of Madagascar

    International Nuclear Information System (INIS)

    Rajaobelison, J.; Ramaroson, V.; Randrianasolo, A.; Randrianarisoa, H.; Mamifarananahary, E.; Ranaivoarisoa, A.

    2004-01-01

    Fresh water access is one of the main issues in the South-West of Madagascar. Most people in this area draw water from surface water which is usually of bad quality and source of stomach diseases. The only reliable water resource is groundwater. However, the latter is more or less vulnerable to geogenic and anthropogenic contaminants. Use of 2 H, 3 H and 18 O environmental tracers has contributed to localize and estimate the active and potential focuses of contamination in shallower and deeper aquifers, within the frame of a preliminary study of ground waters vulnerability to contaminants.

  9. Tissue-specific differences in 2-fluoro-2-deoxyglucose metabolism beyond FDG-6-P: a 19F NMR spectroscopy study in the rat.

    Science.gov (United States)

    Southworth, Richard; Parry, Craig R; Parkes, Harold G; Medina, Rodolfo A; Garlick, Pamela B

    2003-12-01

    2-Fluoro-[(18)F]-2-deoxy-glucose (FDG) is a positron-emitting analogue of glucose used clinically in positron emission tomography (PET) to assess glucose utilization in diseased and healthy tissue. Originally developed to measure local cerebral glucose utilization rates, it has now found applications in tumour diagnosis and in the study of myocardial glucose uptake. Once taken up into the cell, FDG is phosphorylated to FDG-6-phosphate (FDG-6-P) by hexokinase and was originally believed to be trapped as a terminal metabolite. This 'metabolic trapping' of FDG-6-P forms the basis of the analysis of PET data. In this study, we have used (19)F NMR spectroscopy to investigate FDG metabolism following the injection of a bolus of the glucose tracer into the rat (n=6). Ninety minutes after the (19)FDG injection, the brain, heart, liver and kidneys were removed and the (19)FDG metabolites in each were extracted and quantified. We report that significant metabolism of FDG occurs beyond FDG-6-P in all organs examined and that the extent of this metabolism varies from tissue to tissue (degree of metabolism beyond FDG-6-P, expressed as percentage of total organ FDG content, was brain 45 +/- 3%; heart 29 +/- 2%; liver 22+/-3% and kidney 17 +/- 3%, mean +/- SEM n=6). Furthermore, we demonstrate that the relative accumulation of each metabolite was tissue-dependent and reflected the metabolic and regulatory characteristics of each organ. Such inter-tissue differences may have implications for the mathematical modelling of glucose uptake and phosphorylation using FDG as a glucose tracer. Copyright 2003 John Wiley & Sons, Ltd.

  10. Dating of young groundwater using tritium and gaseous tracers (SF6, SF5CF3, CFC-12, H-1301): case study from southern Poland

    Science.gov (United States)

    Rozanski, Kazimierz; Bartyzel, Jakub; Dulinski, Marek; Kuc, Tadeusz; Sliwka, Ireneusz; Mochalski, Pawel; Kania, Jaroslaw; Witczak, Stanislaw

    2013-04-01

    Groundwater is an important source of potable water in many countries. While it covers ca. 50% of the global drinking water needs, in Europe this share is even higher, reaching approximately 70%. Nowadays, this strategic resource is at risk due to anthropogenic pollutants of various nature entering shallow aquifers. Proper management of groundwater resources requires thorough understanding of groundwater dynamics on time scales characteristic for the history of pollutant input to groundwater. The bomb-tritium has been used for several decades now as a tracer of choice to detect recent recharge and to quantify groundwater residence times on time scales extending from several years to several decades. The lumped-parameter modeling was the most often employed approach in this context. Since nowadays atmospheric concentrations of tritium are approaching natural levels in most parts of the world, the usage of this tracer has become more problematic. Therefore, there is a growing interest in alternative indicators of groundwater age in shallow aquifers. Anthropogenic trace gases present in the atmosphere, such as freons (CFC-11, CFC-12, CFC-113) and sulfur hexafluoride (SF6), have been applied in numerous case studies as substitutes of tritium. Here we present the results of a comprehensive study aimed at quantifying mean residence time of groundwater in the recharge area of porous sandy aquifer system located in the southern Poland. The principal economic role of the aquifer, consisting of two water-bearing strata, is to provide potable water for public and private users. The yield of the aquifer is insufficient to meet all the needs and, as a consequence, licensing conflicts arise between water supply companies and industry on the amount of water available for safe exploitation. To quantify residence time distribution (RTD) functions of water parcels arriving at the production wells located in the recharge area of the aquifer, tritium along with several gaseous tracers

  11. Exploring Hydrofluorocarbons as Groundwater Age Tracers (Invited)

    Science.gov (United States)

    Haase, K. B.; Busenberg, E.; Plummer, L. N.; Casile, G.; Sanford, W. E.

    2013-12-01

    Groundwater dating tracers are an essential tool for analyzing hydrologic conditions in groundwater systems. Commonly used tracers for dating post-1940's groundwater include sulfur hexafluoride (SF6), chlorofluorocarbons (CFCs), 3H-3He, and other isotopic tracers (85Kr, δ2H and δ18O isotopes, etc.). Each tracer carries a corresponding set of advantages and limitations imposed by field, analytical, and interpretive methods. Increasing the number available tracers is appealing, particularly if they possess inert chemical properties and unique temporal emission histories from other tracers. Atmospherically derived halogenated trace gases continue to hold untapped potential for new tracers, as they are generally inert and their emission histories are well documented. SF5CF3, and CFC-13 were previously shown to have application as dating tracers, though their low mixing ratios and low solubility require large amounts of water to be degassed for their quantification. Two related groups of compounds, hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are hypothesized to be potential age tracers, having similar mixing ratios to the CFCs and relatively high solubility. However, these compounds yield gas chromatography electron capture detector (GC-ECD) responses that are 10-2 -10-5 less than CFC-12, making purge and trap or field stripping GC-ECD approaches impractical. Therefore, in order to use dissolved HCFCs and HFCs as age tracers, different approaches are needed. To solve this problem, we developed an analytical method that uses an atomic emission detector (GC-AED) in place of an ECD to detect fluorinated compounds. In contrast to the ECD, the AED is a universally sensitive, highly linear, elementally specific detector. The new GC-AED system is being used to measure chlorodifluoromethane (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), and other fluorinated compounds in one liter water samples to study their potential as age dating tracers. HCFC-22 is a

  12. Studies in iodine metabolism: Progress report, July 1968-July 1969

    Energy Technology Data Exchange (ETDEWEB)

    Van Middlesworth, L.

    1987-01-01

    This document describes research on iodine metabolism conducted at the University of Tennessee, Memphis between July 1968 and July 1969. The author and his research team prepared autoradiographs of rat thyroids from individuals exposed to Iodine 125 in utero. Additional studies were conducted to determine the effect on hypothalamic lesions on iodide metabolism in rats; to evaluate an iodide-specific electrode for measuring iodide levels in blood or urine; and to study the amount of thyroxine absorption from the intestine. An analysis of bovine and sheep thyroids from eight locations provided additional information on global fallout levels. 21 figs., 2 tabs.

  13. Radioactive tracers as a tool for the study of in situ meiofaunal-microbial trophic interactions in marine sediments

    International Nuclear Information System (INIS)

    Carman, K.R.

    1989-01-01

    Three methods of delivering labeled substrates to natural cores of sediments were compared. Slurried sediments disrupted the sedimentary structure and significantly altered uptake of labeled substrates by copepod species. Thus, disruption of sedimentary structure can significantly alter microbial-meiofaunal interactions and influence the results of grazing studies. The [ 3 H]-thymidine technique for measuring bacterial production was evaluated. The metabolic fate of labeled thymidine in a coastal marine sediment was not consistent with assumptions necessary for measuring bacterial production or its consumption by meiofauna. Microautoradiography was used to demonstrate the sedimentary microalgae and heterotrophic bacteria can be selectively labeled with [ 14 C]bicarbonate and labeled organic substrates, respectively. A study was performed to determine if radioactivity measured in copepods from grazing experiments was the result of ingestion of labeled microorganisms or the result of uptake by non-feeding processes. Uptake of label by copepods from [ 14 C]-bicarbonate was due almost exclusively to grazing on microalgae. Uptake of label by copepods from [ 14 C]-acetate, however, resulted from activity by epicuticular bacteria and was not due to ingestion of labeled bacteria

  14. Justice at work and metabolic syndrome: the Whitehall II study.

    Science.gov (United States)

    Gimeno, David; Tabák, Adám G; Ferrie, Jane E; Shipley, Martin J; De Vogli, Roberto; Elovainio, Marko; Vahtera, Jussi; Marmot, Michael G; Kivimäki, Mika

    2010-04-01

    Growing evidence shows that high levels of justice are beneficial for employee health, although biological mechanisms underlying this association are yet to be clarified. We aim to test whether high justice at work protects against metabolic syndrome. A prospective cohort study of 20 civil service departments in London (the Whitehall II study) including 6123 male and female British civil servants aged 35-55 years without prevalent coronary heart disease at baseline (1985-1990). Perceived justice at work was determined by means of questionnaire on two occasions between 1985 and 1990. Follow-up for metabolic syndrome and its components occurring from 1990 to 2004 was based on clinical assessments on three occasions over more than 18 years. Cox proportional hazard models adjusted for age, ethnicity and employment grade showed that men who experienced a high level of justice at work had a lower risk of incident metabolic syndrome than employees with a low level of justice (HR 0.75; 95% CI 0.63 to 0.89). There was little evidence of an association between organisational justice and metabolic syndrome or its components in women (HR 0.88; 95% CI 0.67 to 1.17). Our prospective findings provide evidence of an association between high levels of justice at work and the development of metabolic syndrome in men.

  15. Tracer monitoring of enhanced oil recovery projects

    Directory of Open Access Journals (Sweden)

    Kleven R.

    2013-05-01

    Full Text Available In enhanced oil recovery (EOR, chemicals are injected into the oil reservoir, either to increase macroscopic sweep efficiency, or to reduce remaining oil saturation in swept zones. Tracers can be used to identify reservoirs that are specifically suited for EOR operations. Injection of a selection of partitioning tracers, combined with frequent sample analysis of produced fluids, provides information suited for estimation of residual oil saturation. Tracers can also be used to evaluate and optimize the application of EOR chemicals in the reservoir. Suitable tracers will follow the EOR chemicals and assist in evaluation of retention, degradation or trapping. In addition to field applications, tracers also have a large potential as a tool to perform mechanistic studies of EOR chemicals in laboratory experiments. By labelling EOR chemicals with radioactive isotopes of elements such as H, C and S, detailed studies of transport mechanisms can be carried out. Co-injection of labelled compounds in dynamic flooding experiments in porous media will give information about retention or separation of the unique compounds constituting the chemical formulation. Separation of such compounds may be detrimental to obtaining the EOR effect expected. The paper gives new information of specific methods, and discusses current status for use of tracers in EOR operations.

  16. Models for tracer flow

    International Nuclear Information System (INIS)

    Zuber, A.

    1983-01-01

    A review and discussion is given of mathematical models used for interpretation of tracer experiments in hydrology. For dispersion model, different initial and boundary conditions are related to different injection and detection modes. Examples of applications of various models are described and commented. (author)

  17. A contribution to the study of radioactive waste dilution in the Rhone involving tests with a rhodamine B tracer

    International Nuclear Information System (INIS)

    Rodier, J.; Marichal, M.

    1961-01-01

    The process whereby waste from the Marcoule plant mixes with the water in the Rhone was followed in tests with rhodamine as a chemical tracer. Satisfactory dispersion was noted less than 4 km downstream from the waste discharge duct outlet, and the degree of homogeneity was considered to be satisfactory at the bridge of Roquemaure, und perfect at Avignon. This investigation not only revealed a complete absence of any preferential flow paths containing high radioactive waste concentrations, but it also enabled the most representative points to be selected at which to take Rhone water samples during future radioactive waste discharges. Reprint of a paper published in 'La Houille Blanche' N. 5 - Aug 196, p. 636-641 [fr

  18. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

    International Nuclear Information System (INIS)

    Crossley, D.A. Jr.

    1979-01-01

    Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one

  19. Applications of isotopes. [Need and cost of stable iotopes for use as tracers in biomedical and environmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Kirby-Smith, J.S.

    1976-01-01

    Current and potential applications of stable isotopes as tracers in a number of biomedical and environmental areas are discussed. It is pointed out that a wide variety of problems exist in these fields whose solutions in principle are amenable to the isotopic approach. The number and diversity of these problems as well as the unique role stable isotopes can play in their solution illustrate the importance of achieving and maintaining a broad inventory of isotopic species. Experience has demonstrated unequivocally an additional overriding requirement for widespread exploration of stable isotopes by the scientific and technical community, i.e., the need for low cost availability of the materials in quantity. Some representative applications of /sup 12/C, /sup 13/C, /sup 14/N, /sup 15/N, /sup 16/O, /sup 17/O, and /sup 18/O are discussed.

  20. Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Crossley, Jr, D A

    1979-07-15

    Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one (drought).

  1. Radioactive Lysine in Protein Metabolism Studies

    Science.gov (United States)

    Miller, L. L.; Bale, W. F.; Yuile, C. L.; Masters, R. E.; Tishkoff, G. H.; Whipple,, G. H.

    1950-01-09

    Studies of incorporation of DL-lysine in various body proteins of the dog; the time course of labeled blood proteins; and apparent rate of disappearance of labeled plasma proteins for comparison of behavior of the plasma albumin and globulin fractions; shows more rapid turn over of globulin fraction.

  2. NMR studies of cerebral metabolism in vivo

    International Nuclear Information System (INIS)

    Prichard, J.W.

    1986-01-01

    The nature and extent of the potential synergism between PET and NMR methods is not yet well appreciated in the biomedical community. The long-range interest of medical neurobiology will be well served by efforts of PET and NMR scientists to follow each others' work so that opportunities for productive interchange can be efficiently exploited. Appreciation of the synergism by the rest of the biomedical community will follow naturally. PET is said by the people doing it to be still in its infancy, for they are more concerned with advancing their discipline than with admiring its already impressive achievements. On the scale of the same developmental metaphor, many NMR methods for studying the living human brain are still in utero. The best way to provide the reader a sense of the current status and future course of NMR research in medical neurobiology is by discussion of published in vivo studies. Such a discussion, adapted from another article is what follows

  3. Analysis of blood clearance and labeled metabolites for the estrogen receptor tracer [F-18]-16α-fluorestradiol (FES)

    International Nuclear Information System (INIS)

    Mankoff, David A.; Tewson, Timothy J.; Eary, Janet F.

    1997-01-01

    [F-18] 16α-Fluoroestradiol (FES) has been shown to be a tracer of estrogen receptor content in breast tumors; however, quantitative analysis of FES images is complicated by the rapid metabolism of the tracer in vivo. To optimize FES PET imaging studies and to provide an input function for the quantitative analysis of the tracer FES uptake in breast tumors, we studied the clearance and metabolism of FES in 15 breast cancer patients. FES clearance, protein binding, and metabolite production and limited assays to determine the identity of labeled metabolites were performed. These studies show that FES was rapidly cleared from the blood and metabolized; at 20 min only 20% of the circulating radioactivity was unmetabolized FES, and much of this was protein bound. The detectable metabolites in either blood or urine are conjugation products, largely the glucuronide and the sulfate of FES, and these are excreted through the kidneys at a rate comparable to their introduction into the circulation. After 20 min postinjection the blood levels of radioactivity remain fairly constant. Our results, the first report on human metabolites, are in close agreement with previous animal studies of FES metabolism. These studies show that because FES clearance is rapid and metabolite background is nearly constant, imaging starting at 20 to 30 min after injection may provide good visualization of estrogen-containing tissues. Labeled metabolites need to be accounted for in quantifying FES uptake

  4. Study of collagen metabolism after β radiation injury

    International Nuclear Information System (INIS)

    Zhou Yinghui; Xulan; Wu Shiliang; Zhang Xueguang; Chen Liesong

    2000-01-01

    Objective: To investigate the change of collagen metabolism and it's regulation after β radiation. Method: The animal model of β radiation injury was established by the β radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 was tested. The contents of TGF-β 1 , IL-6 were also detected. Results: After exposure to β radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-β 1 , IL-6 increased. Conclusion: The changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-β 1 and IL-6 may be essential in the regulation of the collagen metabolism

  5. Xanthine tracers and their preparation

    International Nuclear Information System (INIS)

    Groman, E.V.; Cabelli, M.D.

    1980-01-01

    Compounds useful as tracers in the radioimmunoassay of xanthine derivatives such as theophylline and pharmacologically related drugs are described. They are substituted xanthines in which at least one substituted radical contains radioiodine. The tracers are made by linking radioiodinatable or preradioiodinated radicals to the xanthine derivative which is to be assayed. The tracers may be employed in known radioimmunoassay techniques. (author)

  6. Preliminary study of metabolic radiotherapy with 188Re via small animal imaging

    International Nuclear Information System (INIS)

    Antoccia, A.; Baldazzi, G.; Bello, M.

    2006-01-01

    188 Re is a β - (Emax=2.12 MeV) and γ (155 keV) emitter. Since its chemistry is similar to that of the largely employed tracer, 99m Tc, molecules of hyaluronic acid (HA) have been labelled with 188 Re to produce a target specific radiopharmaceutical. The radiolabeled compound, i.v. injected in healthy mice, is able to accumulate into the liver after a few minutes. To study the effect of metabolic radiotherapy in mice, we have built a small gamma camera based on a matrix of YAP:Ce crystals, with 0.6x0.6x10 mm 3 pixels, read out by a R2486 Hamamatsu PSPMT. A high-sensitivity 20 mm thick lead parallel-hole collimator, with hole diameter 1.5 mm and septa of 0.18 mm, is placed in front of the YAP matrix. Preliminary results obtained with various phantoms containing a solution of 188 Re and with C57 black mice injected with the 188 Re-HA solution are presented. To increase the space resolution and to obtain two orthogonal projections simultaneously we are building in parallel two new cameras to be positioned at 90 degrees. They use a CsI(Tl) matrix with 1x1x5 mm 3 pixels read out by H8500 Hamamatsu Flat panel PMT

  7. Nuclear medicine studies for the detection and metabolism of fibrinopeptide A

    International Nuclear Information System (INIS)

    Stehle, G.

    1982-01-01

    A modified method of the double antibody radioimmunoassay for the detection of Fibrinopeptide A (FPA) is presented. The change is primarily a shortening in time needed for this method from 15 to 4 hours by means of the substitution of the second antibody donkey for the second antibody goat with a simultaneous improvement of the specificity and an optimization of the conformity of the measured FPA concentrations. The second part of this work reports on the behaviour of FPA in vitro and in vivo in rabbits. The in vitro studies with 125I-FPA showed that there is no definite affinity of the peptide for blood components, that as a result of losses during the preparation the immunoreactivity of only 60% of the FPA can be determined with the IRA, and that 125I-FPA only loosely accumulates on proteins. The effective half-lives in blood of 25'' (α), 7' (β), 30' (γ) and 180' (δ) were determined. Weak metabolic reactions result in the indicator substance being stably present in the circ evenuation after 60', but it is quickly eliminated from the blood. An activity maximum was detected through scintigraphy shortly after the tracer dose in the heart, liver and kidneys, but after that it dropped exponentially and there was an increased concentration in the bladder after glomerular siltration in the kidneys. As a result of enzymatic processes in the tubulus of the kidney there is a higher portion of fragmented peptide in the urin than simultaneously in the plasma. (TRV) [de

  8. Association of sleep quality components and wake time with metabolic syndrome: The Qazvin Metabolic Diseases Study (QMDS), Iran.

    Science.gov (United States)

    Zohal, Mohammadali; Ghorbani, Azam; Esmailzadehha, Neda; Ziaee, Amir; Mohammadi, Zahrasadat

    2017-11-01

    The aim of this study was to determine the association of sleep quality and sleep quantity with metabolic syndrome in Qazvin, Iran. this cross sectional study was conducted in 1079 residents of Qazvin selected by multistage cluster random sampling method in 2011. Metabolic syndrome was defined according to the criteria proposed by the national cholesterol education program third Adult treatment panel. Sleep was assessed using the Pittsburgh sleep quality index (PSQI). A logistic regression analysis was used to examine the association of sleep status and metabolic syndrome. Mean age was 40.08±10.33years. Of 1079, 578 (52.2%) were female, and 30.6% had metabolic syndrome. The total global PSQI score in the subjects with metabolic syndrome was significantly higher than subjects without metabolic syndrome (6.30±3.20 vs. 5.83±2.76, P=0.013). In logistic regression analysis, sleep disturbances was associated with 1.388 fold increased risk of metabolic syndrome after adjustment for age, gender, and body mass index. Sleep disturbances component was a predictor of metabolic syndrome in the present study. More longitudinal studies are necessary to understand the association of sleep quality and its components with metabolic syndrome. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  9. Direct comparison of radiation dosimetry of six PET tracers using human whole-body imaging and murine biodistribution studies

    International Nuclear Information System (INIS)

    Sakata, Muneyuki; Oda, Keiichi; Toyohara, Jun; Ishii, Kenji; Nariai, Tadashi; Ishiwata, Kiichi

    2013-01-01

    We investigated the whole-body biodistributions and radiation dosimetry of five 11 C-labeled and one 18 F-labeled radiotracers in human subjects, and compared the results to those obtained from murine biodistribution studies. The radiotracers investigated were 11 C-SA4503, 11 C-MPDX, 11 C-TMSX, 11 C-CHIBA-1001, 11 C-4DST, and 18 F-FBPA. Dynamic whole-body positron emission tomography (PET) was performed in three human subjects after a single bolus injection of each radiotracer. Emission scans were collected in two-dimensional mode in five bed positions. Regions of interest were placed over organs identified in reconstructed PET images. The OLINDA program was used to estimate radiation doses from the number of disintegrations of these source organs. These results were compared with the predicted human radiation doses on the basis of biodistribution data obtained from mice by dissection. The ratios of estimated effective doses from the human-derived data to those from the mouse-derived data ranged from 0.86 to 1.88. The critical organs that received the highest absorbed doses in the human- and mouse-derived studies differed for two of the six radiotracers. The differences between the human- and mouse-derived dosimetry involved not only the species differences, including faster systemic circulation of mice and differences in the metabolism, but also measurement methodologies. Although the mouse-derived effective doses were roughly comparable to the human-derived doses in most cases, considerable differences were found for critical organ dose estimates and pharmacokinetics in certain cases. Whole-body imaging for investigation of radiation dosimetry is desirable for the initial clinical evaluation of new PET probes prior to their application in subsequent clinical investigations. (author)

  10. California GAMA Special Study: Analysis of Carbamazepine, Oxcarbazepine and Metabolites as Wastewater Tracers in Water Resource Studies

    Energy Technology Data Exchange (ETDEWEB)

    Owens, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vu, A. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, B. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-08-20

    The Groundwater Ambient Monitoring and Assessment (GAMA) Program is a comprehensive groundwater quality monitoring program managed by the California State Water Resources Control Board (SWRCB). The GAMA Special Studies project provides analyses and interpretation of constituents of concern that allow assessment of current groundwater conditions. In addition, the Special Studies project develops analyses that will enhance the monitoring and assessment effort by focusing on specific constituents of concern and water quality parameters, such as disinfection byproducts (DBP), wastewater indicators, and redox conditions, as it relates to irrigation and groundwater management. This study developed a robust analytical method for the quantitation of CBZ, OXC, CBZ-E, CBZ-DiOH, and CBZ-10-OH in wastewater treatement plant (WWTP) effluent and in groundwater in the parts per trillion range.

  11. Linking the formation of molecular clouds and high-mass stars: a multi-tracer and multi-scale study

    International Nuclear Information System (INIS)

    Nguyen-Luong, Quang

    2012-01-01

    Star formation is a complex process involving many physical processes acting from the very large scales of the galaxy to the very small scales of individual stars. Among the highly debated topics, the gas to star-formation-rate (SFR) relation is an interesting topic for both the galactic and extragalactic communities. Although it is studied extensively for external galaxies, how this relation behaves with respect to the molecular clouds of the Milky Way is still unclear. The detailed mechanisms of the formation of molecular clouds and stars, especially high-mass stars, are still not clear. To tackle these two questions, we investigate the molecular cloud formation and the star formation activities in the W43 molecular cloud complex and the G035.39-00.33 filament. The first goal is to infer the connections of the gas-SFR relations of these two objects to those of other galactic molecular clouds and to extragalactic ones. The second goal is to look for indications that the converging flows theory has formed the W43 molecular cloud since it is the first theory to explain star formation self-consistently, from the onset of molecular clouds to the formation of seeds of (high-mass) stars. We use a large dataset of continuum tracers at 3.6--870 μm extracted from Galaxy-wide surveys such as HOBYS, EPOS, Hi-GAL, ATLASGAL, GLIMPSE, and MIPSGAL to trace the cloud structure, mass and star formation activities of both the W43 molecular cloud complex and the G035.39-00.33 filament. To explore the detailed formation mechanisms of the molecular cloud in W43 from low-density to very high-density gas, we take advantage of the existing H_I, "1"3CO 1-0 molecular line data from the VGPS and GRS surveys in combination with the new dedicated molecular line surveys with the IRAM 30 m. We characterise the W43 molecular complex as being a massive complex (M(total) ∼ 7.1 *10"6 M. over spatial extent of ∼ 140 pc), which has a high concentration of dense clumps (M(clumps) ∼ 8.4*10"5 M

  12. Development of new technology for the use of stable isotopic tracers in the study of human health and disease

    International Nuclear Information System (INIS)

    Hacyey, D.L.; Klein, P.D.; Szczepanik, P.A.; Niu, W.; Stellaard, F.; Tserng, K.Y.

    1977-01-01

    This program has five major aspects: first, the development of analytical instrumentation of requisite sensitivity, stability, and simplicity to conduct stable isotope measurements in a routine manner; second, the development of appropriately labeled compounds for metabolic investigations, initially through custom syntheses but eventually through commercial sources; third, development of analytical methodology to isolate, purify, and determine the isotopic content of specific organic compounds reflecting metabolic processes or disease states; fourth, collaborative development of clinical applications and testing on a routine basis, through a network of clinical centers around the country; and finally, the collection and dissemination of stable isotope information on an international scale through survey publications and conferences

  13. In vivo {sup 13}C MRS studies of carbohydrate metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, Jane

    2003-07-01

    The work described in this thesis was performed by the author, except where indicated, within the Magnetic Resonance Centre at the University of Nottingham during the period between October 1999 and October 2002. Although much is known about the major pathways of carbohydrate metabolism, there is still much to be learnt about the exact mechanisms of many of these pathways. Of particular interest is how these pathways are modified under different physiological conditions and in diseased states. {sup 13}C NMR spectroscopy provides a non-invasive means for studying carbohydrate metabolism in vivo, and the work presented within this thesis gives two such examples of this in human subjects. Natural abundance {sup 13}C NMR spectroscopy was used to measure glycogen levels in gastrocnemius muscle. The diurnal changes in response to mixed meals were measured in both type 2 diabetic subjects and age and weight matched controls. Metabolic studies were performed to complement the NMR measurements. The data obtained in these studies show the effect of the failure of muscle glucose storage upon post-prandial hyperglycaemia despite a supra-normal increase in plasma insulin in type 2 diabetes. {sup 13}C NMR spectroscopy was also used to study cerebral metabolism. Accumulation of {sup 13}C label into glutamate and glutamine following infusion of [1{sup 13}C] glucose allows the determination of the rates of the TCA cycle (F{sub TCA}) and neurotransmitter cycling (F{sub cyc}). These rates were measured in the visual cortex under control and activated conditions. The increases seen in F{sub TCA} upon activation, together with the lack of label accumulation in lactate, suggest that cerebral glucose metabolism is oxidative, even during strong activation. No conclusion can be made as to whether or not a similar increase is seen in F{sub cyc} due to the large associated errors in these values. (author)

  14. In vivo 13C MRS studies of carbohydrate metabolism

    International Nuclear Information System (INIS)

    Halliday, Jane

    2003-01-01

    The work described in this thesis was performed by the author, except where indicated, within the Magnetic Resonance Centre at the University of Nottingham during the period between October 1999 and October 2002. Although much is known about the major pathways of carbohydrate metabolism, there is still much to be learnt about the exact mechanisms of many of these pathways. Of particular interest is how these pathways are modified under different physiological conditions and in diseased states. 13 C NMR spectroscopy provides a non-invasive means for studying carbohydrate metabolism in vivo, and the work presented within this thesis gives two such examples of this in human subjects. Natural abundance 13 C NMR spectroscopy was used to measure glycogen levels in gastrocnemius muscle. The diurnal changes in response to mixed meals were measured in both type 2 diabetic subjects and age and weight matched controls. Metabolic studies were performed to complement the NMR measurements. The data obtained in these studies show the effect of the failure of muscle glucose storage upon post-prandial hyperglycaemia despite a supra-normal increase in plasma insulin in type 2 diabetes. 13 C NMR spectroscopy was also used to study cerebral metabolism. Accumulation of 13 C label into glutamate and glutamine following infusion of [1 1 3 C] glucose allows the determination of the rates of the TCA cycle (F TCA ) and neurotransmitter cycling (F cyc ). These rates were measured in the visual cortex under control and activated conditions. The increases seen in F TCA upon activation, together with the lack of label accumulation in lactate, suggest that cerebral glucose metabolism is oxidative, even during strong activation. No conclusion can be made as to whether or not a similar increase is seen in F cyc due to the large associated errors in these values. (author)

  15. Tracer tests Wairakei

    International Nuclear Information System (INIS)

    McCabe, W.J.; Manning, M.R.; Barry, B.J.

    1980-07-01

    The report summarises the radioactive tracer tests, using iodine-131 and bromine-82, made in the Wairakei geothermal field over the period 1978-80. Injection of tracer into three wells with strong cool water downflows at about 300-400m below ground level, produced strong rapid responses from the only deep wells feeding from about 800-1000m and lying in the south-westerly direction from the injection wells, i.e. parallel to the fault planes. Shallower wells, even though in some cases much closer to the injection well, reacted much more slowly. Velocities, as measured by peak arrival times, as high as 22m/h over 200m and 11m/h over 650m, were found. The flow patterns for the cool water feeds to the production area are discussed

  16. Radioactive tracers in Sedimentology

    International Nuclear Information System (INIS)

    Rodrigues, H.T.

    1973-01-01

    First is given a broad description of the uses of radioactive tracers in Sedimentology. The general method is established, including determinations of probability and standard deviation. Following are determined: the response law of the detector, the minimum mass for statistical detection, and the minimum mass for dynamic detection. The granularity is an important variable in these calculations. Final conclusions are given, and results are compared with existing theories

  17. Study of ternary-component bismuth molybdate catalysts by 18O2 tracer in the oxidation of propylene to acrolein

    International Nuclear Information System (INIS)

    Ueda, W.; Moro-oka, Y.; Ikawa, T.

    1981-01-01

    Participation of lattice oxide ions of ternary-component bismuth molybdate catalysts M-Bi-Mo-O (M = Ni, Co, Mg, Mn, Ca, Sr, Ba, and Pb) was investigated using the 18 O 2 tracer in the selective oxidation of propylene to acrolein. The participation of the lattice oxide ions in the oxidation is prominent on every catalyst but the extent of the participation varies significantly depending on the structure of the catalyst. Only lattice oxide ions in the bismuth molybdate phase are incorporated into the oxidized products on the catalysts (M = Ni, Co, Mg, and Mn) where M have smaller ionic radius than Bi 3+ ; catalyst particles are composed of a shell of bismuth molybdates and a core of MMoO 4 . On the other hand, whole oxide ions in the active particles are involved in the oxidation on catalysts having a scheelite-type structure (M = Ca, Sr, Ba, and Pb) where M has a comparable ionic radius to Bi 3+

  18. Study of sensitivity and application of some tracers of use in hydrologic works; Estudio de sensibilidad y aplicacion de algunos trazadores de empleo en trabajos hidrologicos

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, M C [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1980-05-15

    Inside the Industrial Applications Management, particularly in the Hydrology department, in the ININ outlined diverse problems are had in the study of underground waters and surface waters that either in a particular way, or in inter institutional collaboration (SARH, CFE, UNAM) it seen the necessity to solve this problem in the interconnection aspects in aquifer, expenses and contamination. One of the medullary parts that are had in this study is the applied evaluation of the tracer one that it presents two general aspects: a) determination method and b) Applicability depending on the land type that one has in the current to be applied. This study seeks according to: the sensibility reached with each one, and the evaluation of some other parameters like used time, cost and mainly realization feasibility at field level, to present some alternative for the use of them. (Author)

  19. Journal: Efficient Hydrologic Tracer-Test Design for Tracer ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed to facilitate the design of tracer tests by root determination of the one-dimensional advection-dispersion equation (ADE) using a preset average tracer concentration which provides a theoretical basis for an estimate of necessary tracer mass. The method uses basic measured field parameters (e.g., discharge, distance, cross-sectional area) that are combined in functional relatipnships that descrive solute-transport processes related to flow velocity and time of travel. These initial estimates for time of travel and velocity are then applied to a hypothetical continuous stirred tank reactor (CSTR) as an analog for the hydrological-flow system to develop initial estimates for tracer concentration, tracer mass, and axial dispersion. Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to be necessary for descri

  20. Metabolic imaging using PET

    International Nuclear Information System (INIS)

    Kudo, Takashi

    2007-01-01

    There is growing evidence that myocardial metabolism plays a key role not only in ischaemic heart disease but also in a variety of diseases which involve myocardium globally, such as heart failure and diabetes mellitus. Understanding myocardial metabolism in such diseases helps to elucidate the pathophysiology and assists in making therapeutic decisions. As well as providing information on regional changes, PET can deliver quantitative information about both regional and global changes in metabolism. This capability of quantitative measurement is one of the major advantages of PET along with physiological positron tracers, especially relevant in evaluating diseases which involve the whole myocardium. This review discusses major PET tracers for metabolic imaging and their clinical applications and contributions to research regarding ischaemic heart disease and other diseases such as heart failure and diabetic heart disease. Future applications of positron metabolic tracers for the detection of vulnerable plaque are also highlighted briefly. (orig.)

  1. Nuclear magnetic resonance studies of epithelial metabolism and function

    International Nuclear Information System (INIS)

    Balaban, R.S.

    1982-01-01

    Nuclear magnetic resonance (NMR) is a noninvasive technique for studying cellular metabolism and function. In this review the general applications and advantages of NMR will be discussed with specific reference to epithelial tissues. Phosphorus NMR investigations have been performed on epithelial tissues in vivo and in vitro; however, other detectable nuclei have not been utilized to date. Several new applications of phosphorus NMR to epithelial tissues are also discussed, including studies on isolated renal tubules and sheet epithelia

  2. Metabolic studies in older mentally retarded patients: significance of metabolic testing and correlation with the clinical phenotype.

    NARCIS (Netherlands)

    Buggenhout, G.J.C.M. van; Trijbels, J.M.F.; Wevers, R.A.; Trommelen, J.C.M.; Hamel, B.C.J.; Brunner, H.G.; Fryns, J.P.

    2001-01-01

    In 471 adult mentally retarded adult patients (mean age 46 years; 92.6% males) living in an institution for the mentally retarded, a clinical examination, cytogenetic and molecular studies were done. 306 patients were screened for metabolic disorders. In 7 additional patients a metabolic disorder

  3. Atmospheric Gas Tracers in Groundwater: Theory, Sampling. Measurement and Interpretation

    International Nuclear Information System (INIS)

    Bayari, C.S.

    2002-01-01

    Some of the atmospheric gasses posses features that are sought in an environmental tracer of hydrogeologic interest. Among these, chlorofluorocarbons, sulfur hegzafluoride, carbon tetrachloride, methyl chloroform, krypton-85 etc. have found increasing use in groundwater age dating studies during the last ten years. This paper explains the theory of their use as tracer and discusses the major concerns as related to their sampling and analyses. Factors affecting their applicability and the approach to interpret tracer gas data is briefly outlined

  4. Tracers and Tracer Testing: Design, Implementation, Tracer Selection, and Interpretation Methods

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Shook; Shannon L.; Allan Wylie

    2004-01-01

    Conducting a successful tracer test requires adhering to a set of steps. The steps include identifying appropriate and achievable test goals, identifying tracers with the appropriate properties, and implementing the test as designed. When these steps are taken correctly, a host of tracer test analysis methods are available to the practitioner. This report discusses the individual steps required for a successful tracer test and presents methods for analysis. The report is an overview of tracer technology; the Suggested Reading section offers references to the specifics of test design and interpretation.

  5. The method of radioactive tracer for measuring the amount of inorganic nanoparticles in biological samples

    Science.gov (United States)

    Buzulukov, Yu; Antsiferova, A.; Demin, V. A.; Demin, V. F.; Kashkarov, P.

    2015-11-01

    The method to measure the mass of inorganic nanoparticles in biological (or any other samples) using nanoparticles labeled with radioactive tracers is developed and applied to practice. The tracers are produced in original nanoparticles by radioactive activation of some of their atomic nuclei. The method of radioactive tracers demonstrates a sensitivity, specificity and accuracy equal or better than popular methods of optical and mass spectrometry, or electron microscopy and has some specific advantages. The method can be used for study of absorption, distribution, metabolism and excretion in living organism, as well as in ecological and fundamental research. It was used in practice to study absorption, distribution, metabolism and excretion of nanoparticles of Ag, Au, Se, ZnO, TiO2 as well as to study transportation of silver nanoparticles through the barriers of blood-brain, placenta and milk gland of rats. Brief descriptions of data obtained in experiments with application of this method included in the article. The method was certified in Russian Federation standard system GOST-R and recommended by the Russian Federation regulation authority ROSPOTREBNADZOR for measuring of toxicokinetic and organotropy parameters of nanoparticles.

  6. Measurements of waste tank passive ventilation rates using tracer gases

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Olsen, K.B.; Sklarew, D.S.; Evans, J.C.; Remund, K.M.

    1997-09-01

    This report presents the results of ventilation rate studies of eight passively ventilated high-level radioactive waste tanks using tracer gases. Head space ventilation rates were determined for Tanks A-101, AX-102, AX-103, BY-105, C-107, S-102, U-103, and U-105 using sulfur hexafluoride (SF 6 ) and/or helium (He) as tracer gases. Passive ventilation rates are needed for the resolution of several key safety issues. These safety issues are associated with the rates of flammable gas production and ventilation, the rates at which organic salt-nitrate salt mixtures dry out, and the estimation of organic solvent waste surface areas. This tracer gas study involves injecting a tracer gas into the tank headspace and measuring its concentration at different times to establish the rate at which the tracer is removed by ventilation. Tracer gas injection and sample collection were performed by SGN Eurisys Service Corporation and/or Lockheed Martin Hanford Corporation, Characterization Project Operations. Headspace samples were analyzed for He and SF 6 by Pacific Northwest National Laboratory (PNNL). The tracer gas method was first demonstrated on Tank S-102. Tests were conducted on Tank S-102 to verify that the tracer gas was uniformly distributed throughout the tank headspace before baseline samples were collected, and that mixing was sufficiently vigorous to maintain an approximately uniform distribution of tracer gas in the headspace during the course of the study. Headspace samples, collected from a location about 4 in away from the injection point and 15, 30, and 60 minutes after the injection of He and SF 6 , indicated that both tracer gases were rapidly mixed. The samples were found to have the same concentration of tracer gases after 1 hour as after 24 hours, suggesting that mixing of the tracer gas was essentially complete within 1 hour

  7. Metabolic and inflammatory profiles of biomarkers in obesity, metabolic syndrome, and diabetes in a Mediterranean population. DARIOS Inflammatory study.

    Science.gov (United States)

    Fernández-Bergés, Daniel; Consuegra-Sánchez, Luciano; Peñafiel, Judith; Cabrera de León, Antonio; Vila, Joan; Félix-Redondo, Francisco Javier; Segura-Fragoso, Antonio; Lapetra, José; Guembe, María Jesús; Vega, Tomás; Fitó, Montse; Elosua, Roberto; Díaz, Oscar; Marrugat, Jaume

    2014-08-01

    There is a paucity of data regarding the differences in the biomarker profiles of patients with obesity, metabolic syndrome, and diabetes mellitus as compared to a healthy, normal weight population. We aimed to study the biomarker profile of the metabolic risk continuum defined by the transition from normal weight to obesity, metabolic syndrome, and diabetes mellitus. We performed a pooled analysis of data from 7 cross-sectional Spanish population-based surveys. An extensive panel comprising 20 biomarkers related to carbohydrate metabolism, lipids, inflammation, coagulation, oxidation, hemodynamics, and myocardial damage was analyzed. We employed age- and sex-adjusted multinomial logistic regression models for the identification of those biomarkers associated with the metabolic risk continuum phenotypes: obesity, metabolic syndrome, and diabetes mellitus. A total of 2851 subjects were included for analyses. The mean age was 57.4 (8.8) years, 1269 were men (44.5%), and 464 participants were obese, 443 had metabolic syndrome, 473 had diabetes mellitus, and 1471 had a normal weight (healthy individuals). High-sensitivity C-reactive protein, apolipoprotein B100, leptin, and insulin were positively associated with at least one of the phenotypes of interest. Apolipoprotein A1 and adiponectin were negatively associated. There are differences between the population with normal weight and that having metabolic syndrome or diabetes with respect to certain biomarkers related to the metabolic, inflammatory, and lipid profiles. The results of this study support the relevance of these mechanisms in the metabolic risk continuum. When metabolic syndrome and diabetes mellitus are compared, these differences are less marked. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  8. Technetium and rhenium complexes with modified fatty acid ligands 4. Evaluation of two new classes of 99mTc-labelled fatty acids as potential tracers for myocardial metabolism imaging

    International Nuclear Information System (INIS)

    Heintz, A.; Kropp, J.; Deussen, A.; Jung, C.M.; Spies, H.

    2002-01-01

    99m Tc-labelled fatty acids were synthesized according to the '3+1' mixed-ligand approach and investigated as potential tracers for myocardial SPECT diagnostics on the model of the isolated guinea pig heart. The results indicate a low but specific myocardial uptake of the 99m Tc fatty acid derivatives subject to chain length and structure. (orig.)

  9. Application of radioisotopes to studies of pesticide metabolism

    International Nuclear Information System (INIS)

    Shishido, Takashi

    1977-01-01

    Metabolic form and structural change of pesticides in the living body were mentioned. In the early stage of the study, 14 C, 35 S, 36 Cl, and 32 P were used, and 32 P was used mainly. At present, specimen labelled with 14 C or 3 H can be traced easily with liquid scintillation counter, and metabolic study is performed by using gaschromatography, nuclear magnetism resonant together with mass, and infrared spectrum analysis. Generally, pesticides are fat-soluble compounds. They convert into water-soluble compounds through the changes such as oxidation, reduction, and hydrolysis. Furthermore, they combine with ingredients in the living body, and are taken in. In animals, they are excreted outside the body, and in plants, they are stored after detoxication. Microorganisms break molecules into parts. They are used as energy source, and perform oxidative cleavage of nucleus of aromatic pesticides. (Kanao, N.)

  10. NMR-Metabolic Methodology in the Study of GM Foods

    Directory of Open Access Journals (Sweden)

    Irene D’Amico

    2010-01-01

    Full Text Available The 1H-NMR methodology used in the study of genetically modified (GM foods is discussed. Transgenic lettuce (Lactuca sativa cv "Luxor" over-expressing the Arabidopsis KNAT1 gene is presented as a case study. Twenty-two water-soluble metabolites (amino acids, organic acids, sugars present in leaves of conventional and GM lettuce were monitored by NMR and quantified at two developmental stages. The NMR spectra did not reveal any difference in metabolite composition between the GM lettuce and the wild type counterpart. Statistical analyses of metabolite variables highlighted metabolism variation as a function of leaf development as well as the transgene. A main effect of the transgene was in altering sugar metabolism.

  11. 15N tracer technique for studying efficiency of deep placed fertilizer through nutriseed holder in direct seeded rice

    International Nuclear Information System (INIS)

    Asha, V.S.; Arulmozhiselvan, K.

    2006-01-01

    In order to estimate N use efficiency in deep placement of NPK straight fertilizers, two pot experiments were conducted in high clay soil with direct seeded rice. 15 N urea was used as a tracer. A newly designed 'Nutriseed Holder' was used for simultaneous deep placement of fertilizers and sowing of seeds. Each holder had two cavities, one on top for holding seed and another one at bottom for holding fertilizer material. By implanting a holder in puddled soil, a rice hill was established. The length (5 or 10 cm) and width (8 or 12 mm) of nutriseed holder was standardized while evaluating the effect of Azolla, neem and seed inoculants. Appreciably, deep placement of plain NPK fertilizer in 12 mm holder placed at 5 cm depth recorded the highest grain yield with a yield increase of 81.8 per cent during rabi 2002 (cv CO 43) and 84.8 per cent during summer 2003 (cv CO 47) over broadcast application. Further, it increased recovery of added JSN in grain + straw to the tune of 57.1 per cent in rabi and 54.7 per cent in summer as compared to broadcast application (26.1% in rabi, 34.2 in summer). Deep placement enhanced more retention in soil (up to 9.0% in rabi, 14.6% in summer) whereas broadcast application enhanced more retention in Azolla biomass that was grown in floodwater (up to 2.3 % in rabi, 4.3 % in summer). Use of 12 mm width nutriseed holder aiding deep placement at 5 cm depth was found suitable for deriving high yield and N use efficiency. (author)

  12. 15N tracer studies on N supply from different N fertilizer forms and on localization and losses of fertilizer N - pot experiment in Haplic Chernozem

    International Nuclear Information System (INIS)

    Schulz, E.

    1988-01-01

    In a pot experiment with Haplic Chernozem differing in total carbon content (Static Experiment at Lauchstaedt, 1983), studies were made into N supply from various forms of fertilizers and fertilizer N localization in the plant-soil system. In general, the percentage of fertilizer N in the total N amount taken up by maize was very high (60 to 90%). Both the variate difference method and the tracer technique identified almost equal percentages of fertilizer N in plants after application of pig urine and ammonium nitrate. However, mineralization of soil-borne N after application of sugar beet leaves was overestimated when using the variate difference method. There was no evidence of an additional mobilization of soil-borne N due to fertilization (priming effect). (author)

  13. A pilot study of the feasibility of long-term human bone balance during perimenopause using a {sup 41}Ca tracer

    Energy Technology Data Exchange (ETDEWEB)

    Hui, S.K. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel) and Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota, 420 Delaware Street SE, Mayo Mail Code 494, Minneapolis, MN 55455 (United States)]. E-mail: huixx019@umn.edu; Prior, J. [Deparment of Medicine/Endocrinology, University of British Columbia, Vancouver, B.C., V5Z 1C6 (Canada); Gelbart, Z. [TRIUMF, Vancouver, B.C., V6T2A3 (Canada); Johnson, R.R. [TRIUMF, Vancouver, B.C., V6T2A3 (Canada); Lentle, B.C. [Department of Radiology, University of British Columbia, British Columbia, V8M 1V4 (Canada); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

    2007-06-15

    The mechanisms governing calcium fluxes during bone remodeling processes in perimenopausal women are poorly known. Despite higher, albeit erratic, estradiol levels in perimenopause, spine bone loss is greater than during the first five years past the final menstrual flow when estradiol becomes low. Understanding changes during this dynamic transition are important to prevent fragility fractures in midlife and older women. The exploration of long-lived {sup 41}Ca (T {sub 1/2} = 1.04 x 10{sup 5} yrs) tracer measurements using accelerator mass spectrometry (AMS) leads to the possibility of monitoring bone remodeling balance. With this new technology, we explored a pilot long-term feasibility study of bone health by measuring the {sup 41}Ca trace element in urine for six years from premenopausal to later perimenopausal phases in one midlife woman. We measured bone mineral density in parallel.

  14. Study and development recuperation of Thallium-203 from bombarded targets of this metal in production of Thallium-201 via addition of Thallium-201 radioisotope as a tracer

    International Nuclear Information System (INIS)

    Shirazi, B.

    2006-01-01

    Thallium-203 is the main material for 201 TlCl 3 radiopharmaceutical. It is very important to recover the remaining enriched Thallium-203 in every stage of the process to be reused in the production loop. In this research, the recuperation of Thallium-203 was studied with Dowex 50 WΧ8 ion exchange resin and Thallium-201 as a tracer. The results based on filling of ( 1 8 X 1.5) cm columns with this resin showed that the best flow rate of eluent is 2 ml/min. Also the most suitable volumes are 200 mL (HNO 3 0.05 M), 400 mL (solution of Thallium-203), 100 mL (H 2 O), 500 mL (Citric acid), 100 mL (H 2 0), 100 mL (EDTA 0.5 M and pH∼12.5). 60 mL (H 2 0), respectively

  15. Application of INAA in the characterisation and quantification of Dy-labeled ceramic spheres and their use as inert tracers in soil studies

    International Nuclear Information System (INIS)

    Duke, M.J.M.; Plante, A.F.; McGill, W.B.

    2000-01-01

    An inert, activated tracer method, using sized ceramic spheres custom labeled with ∼15% Dy 2 O 3 manufacture, has been developed to study soil aggregation. Instrumental neutron activation analysis (INAA) with a Slowpoke reactor, using 165m Dy (T 1/2 = 1.26 min), provides an extremely rapid means with which to characterise the Dy-content of the various size fractions of labeled spheres from different production runs. In contrast, the Dy-content (and hence number of spheres) of 5-8 g soil/sphere mixtures is determined using the longer-lived 165 Dy (T 1/2 = 2.33 hrs) following a ∼30-minute decay period during which the otherwise interfering 28 Al (T 1/2 = 2.24 min) preferentially decays. The method is expected to find many applications. (author)

  16. Beach sediments drift study by means of radioactive tracers; L'etude du transport littoral par la methode des traceurs radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The present state of the sediments drift studies by means of radioactive tracers is exposed. Various processes of labelling, immersion and detection, used in France and other countries, are reviewed. A more extended analysis of some aspects of the problem by the same authors can be found in 'La Houille Blanche', number 3, may-june 1959 (Rapport C.E.A. number 1269). (author) [French] L'etude du transport littoral des sediments et galets par la methode des traceurs radioactifs est en plein developpement. Le present rapport precise l'etat actuel de la question. Les techniques de marquage, d'immersion et de detection utilisees en France et a l'etranger sont decrites; une analyse plus detaillee de certains aspects de la question est presentee par les memes auteurs dans 'La Houille Blanche', numero 3, mai-juin 1959 (Rapport C.E.A. numero 1269). (auteur)

  17. Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten; van Heel, Ton; Shan, Chao

    2004-05-12

    A key parameter governing the performance and life-time of a Hot Fractured Rock (HFR) reservoir is the effective heat transfer area between the fracture network and the matrix rock. We report on numerical modeling studies into the feasibility of using tracer tests for estimating heat transfer area. More specifically, we discuss simulation results of a new HFR characterization method which uses surface-sorbing tracers for which the adsorbed tracer mass is proportional to the fracture surface area per unit volume. Sorption in the rock matrix is treated with the conventional formulation in which tracer adsorption is volume-based. A slug of solute tracer migrating along a fracture is subject to diffusion across the fracture walls into the adjacent rock matrix. Such diffusion removes some of the tracer from the fluid in the fractures, reducing and retarding the peak in the breakthrough curve (BTC) of the tracer. After the slug has passed the concentration gradient reverses, causing back-diffusion from the rock matrix into the fracture, and giving rise to a long tail in the BTC of the solute. These effects become stronger for larger fracture-matrix interface area, potentially providing a means for estimating this area. Previous field tests and modeling studies have demonstrated characteristic tailing in BTCs for volatile tracers in vapor-dominated reservoirs. Simulated BTCs for solute tracers in single-phase liquid systems show much weaker tails, as would be expected because diffusivities are much smaller in the aqueous than in the gas phase, by a factor of order 1000. A much stronger signal of fracture-matrix interaction can be obtained when sorbing tracers are used. We have performed simulation studies of surface-sorbing tracers by implementing a model in which the adsorbed tracer mass is assumed proportional to the fracture-matrix surface area per unit volume. The results show that sorbing tracers generate stronger tails in BTCs, corresponding to an effective

  18. Neurotoxicity after intracarotid 1,3-bis(2-chloroethyl)-1-nitrosourea administration in the rat: Hemodynamic changes studied by double-tracer autoradiography

    International Nuclear Information System (INIS)

    Nagahiro, S.; Yamamoto, Y.L.; Diksic, M.; Mitsuka, S.; Sugimoto, S.; Feindel, W.

    1991-01-01

    Changes in blood-brain (BBB) permeability and local cerebral blood flow after intracarotid administration of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) were examined quantitatively in rats with double-tracer autoradiography using [14C]alpha-amino-isobutyric acid and [18F]fluoroantipyrine. Forty-eight female Wistar rats were divided into four groups. The control group (Group 1) received 1 ml of 5% dextrose. The other three groups received three different doses of BCNU dissolved in 5% dextrose: Group 2 rats received 1 mg, Group 3 3 mg, and Group 4 10 mg. The tracer study was performed on Day 1 or Days 4 to 12 after intracarotid administration of BCNU. In 11 rats in Group 2, there were no changes of BBB permeability. Transient BBB permeability changes were seen in the striatum or hippocampus in 3 of the 5 rats (60%) in Group 3 within 24 hours. In 8 of 9 rats (89%) in the same group, late BBB permeability changes were observed in the hypothalamus with or without histological changes. BBB permeability changes were seen in all rats of Group 4. Focal increase of local cerebral blood flow on the infused side compared with the non-infused side of the brain was observed, although not at a significant level, in 5 of 25 rats examined with [18F]fluoroantipyrine. The results of BBB permeability and histological examinations and study of heterogenous distribution by [18F]fluorodeoxyglucose indicated that the ipsilateral subcortical structures such as the hypothalamus, amygdala, internal capsule, and caudate putamen have the highest incidence of neurotoxicity, which are closely related to histopathological damage seen in human BCNU leucoencephalopathy

  19. Tracers of air-sea gas exchange

    International Nuclear Information System (INIS)

    Liss, P.S.

    1988-01-01

    The flux of gas across the air-sea interface is determined by the product of the interfacial concentration difference driving the exchange and a rate constant, often termed the transfer velocity. The concentration-difference term is generally obtained by direct measurement, whereas more indirect approaches are required to estimate the transfer velocity and its variation as a function of controlling parameters such as wind and sea state. Radioactive tracers have proved particularly useful in the estimation of air-sea transfer velocities and, recently, stable purposeful tracers have also started to be used. In this paper the use of the following tracers to determine transfer velocities at the sea surface is discussed: natural and bomb-produced 14 C, dissolved oxygen, 222 Rn and sulphur hexafluoride. Other topics covered include the relation between transfer velocity and wind speed as deduced from tracer and wind-tunnel studies, and the discrepancy between transfer velocities determined by using tracers and from eddy correlation measurements in the atmosphere. (author)

  20. Study of collagen metabolism and regulation after β radiation injury

    International Nuclear Information System (INIS)

    Zhou Yinghui; Xu Lan; Wu Shiliang; Qiu Hao; Jiang Zhi; Tu Youbin; Zhang Xueguang

    2001-01-01

    The animal model of β radiation injury was established by the β radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 were tested. The contents of TGF-β 1 , IL-6 were also detected. The results showed that after exposure to β radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-β 1 , IL-6 increased. The results suggest that changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-β 1 , IL-6 may be essential in the regulation of the collagen metabolism

  1. Study of collagen metabolism and regulation after {beta} radiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Yinghui, Zhou; Lan, Xu; Shiliang, Wu; Hao, Qiu; Zhi, Jiang; Youbin, Tu; Xueguang, Zhang [Suzhou Medical College (China)

    2001-04-01

    The animal model of {beta} radiation injury was established by the {beta} radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 were tested. The contents of TGF-{beta}{sub 1}, IL-6 were also detected. The results showed that after exposure to {beta} radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-{beta}{sub 1}, IL-6 increased. The results suggest that changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-{beta}{sub 1}, IL-6 may be essential in the regulation of the collagen metabolism.

  2. The progress on researching method and metabolism of positron radiopharmaceutical

    International Nuclear Information System (INIS)

    Gan Hongmei; Qiao Jinping; Kong Aiying; Zhu Lin

    2010-01-01

    Positron radiopharmaceuticals are mainly used for PET studies, which are used in the field of nuclear medicine as tracers in the diagnosis and treatment of many diseases. They have important position and function in the clinical diagnosis and treatment. Metabolism or biotransformation will happen when PET radio-pharmaceuticals enter into the body. Understanding the metabolic fate of radiopharmaceutical probes is essential for an accurate analysis and interpretation of positron emission tomography imaging. The recent research progress on PET radiopharmaceuticals metabolism was reviewed in this paper, including the metabolism characteristics, research methods, analytical techniques and so on. (authors)

  3. 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

  4. Use of radioactive tracers in dynamic sedimentology

    International Nuclear Information System (INIS)

    Tola, Francois.

    1982-01-01

    In the first part, developments in the use of radioactive tracers in sedimentology are recalled together with the corresponding fields of application and the identities of the main users. The state-of-the-art in France is also discussed; The main characteristics of the method are then described and compared with those of more classical methods. The results that can be obtained with tracer methods are then outlined. The criteria employed to establish the granulometry characteristics of the tracer, the particular radioisotope to be used, and the masses and activities involved, are treated. A list is then given of the main isotopes available in France and their characteristics. The various different labelling techniques employed are studied together with their respective advantages and disadvantages. The special case of pelitic sediments is mentioned. The use of reduced model isotope generators, double labelling and applications to studies of the mud plug in the Gironde Estuary are also discussed. The methods and materials used for injecting and detecting tracers are described, emphasis being given to the economic factors associated with the use of radioactive tracers in sedimentology. The second part of the report contains two chapters: - studies of transport by driftage: presentation and analysis of results and the application of the Count Rate Balance method to obtain quantitative information on transport; - studies of in-suspension transport of fine sediments in the sea: the procedures adopted from the moment when the tracer is introduced up to the time when the results are analyzed and interpreted, enables the trajectories and mean velocities of the transported sediments to be determined together with their degree of dilution and their settling speeds and rates; it is also possible to investigate the evolution and horizontal dispersion of the sediments in this way. Results from recent experiments are presented in both parts of the report

  5. Delineation and segmentation of cerebral tumors by mapping blood-brain barrier disruption with dynamic contrast-enhanced CT and tracer kinetics modeling-a feasibility study

    International Nuclear Information System (INIS)

    Bisdas, S.; Vogl, T.J.; Yang, X.; Koh, T.S.; Lim, C.C.T.

    2008-01-01

    Dynamic contrast-enhanced (DCE) imaging is a promising approach for in vivo assessment of tissue microcirculation. Twenty patients with clinical and routine computed tomography (CT) evidence of intracerebral neoplasm were examined with DCE-CT imaging. Using a distributed-parameter model for tracer kinetics modeling of DCE-CT data, voxel-level maps of cerebral blood flow (F), intravascular blood volume (v i ) and intravascular mean transit time (t 1 ) were generated. Permeability-surface area product (PS), extravascular extracellular blood volume (v e ) and extraction ratio (E) maps were also calculated to reveal pathologic locations of tracer extravasation, which are indicative of disruptions in the blood-brain barrier (BBB). All maps were visually assessed for quality of tumor delineation and measurement of tumor extent by two radiologists. Kappa (κ) coefficients and their 95% confidence intervals (CI) were calculated to determine the interobserver agreement for each DCE-CT map. There was a substantial agreement for the tumor delineation quality in the F, v e and t 1 maps. The agreement for the quality of the tumor delineation was excellent for the v i , PS and E maps. Concerning the measurement of tumor extent, excellent and nearly excellent agreement was achieved only for E and PS maps, respectively. According to these results, we performed a segmentation of the cerebral tumors on the base of the E maps. The interobserver agreement for the tumor extent quantification based on manual segmentation of tumor in the E maps vs. the computer-assisted segmentation was excellent (κ = 0.96, CI: 0.93-0.99). The interobserver agreement for the tumor extent quantification based on computer segmentation in the mean images and the E maps was substantial (κ = 0.52, CI: 0.42-0.59). This study illustrates the diagnostic usefulness of parametric maps associated with BBB disruption on a physiology-based approach and highlights the feasibility for automatic segmentation of

  6. The use of stable isotopes as minerals tracers in human nutrition research

    International Nuclear Information System (INIS)

    Sajet, A. S.

    2007-01-01

    The idea of using stable isotopes as tracers in metabolic studies of vital systems started when it was noted that stable isotopes have the ability to unite with biomolecules.The article aims to review the methods used to measure quantities of tracer in doses given to donors orally or via intravenous injection, determinants of detection and their estimation as well as the use of mass spectrometer and other devices to measure different stable isotopes. In fact, the use of stable isotopes in nutrition research is an essential technique in order to understand many of the processes related to minerals absorption and the human body composition of water, fat and bones, transportation of food components within the body and estimation of the ages of red blood cells. It is possible to use the secretion of stable isotopes taken by injection to determine the paths of excretion or estimate self-retaining material by the intestine. The stable isotope technology helps to know the mechanics of minerals absorption and excretion in the body. It was possible to find out metabolic reactions of metals using mathematical models based on the measurement of tracers amount in biological fluids in order to know the absorbance situation of metals in the body.

  7. Radiological safety methodology in radioactive tracer applications for hydrodynamics and environmental studies; Metodologia de la seguridad radiologica en el empleo de trazadores radiactivos en estudios hidrodinamicos e ingenieria ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, R; Badano, A; Dellepere, A; Artucio, G; Bertolotti, A [Nuclear Technology National Direction, Montevideo (Uruguay)

    1995-07-01

    The use of radioactive tracer techniques as control sewage disposal contamination in Montevideo Estuarine and Carrasco beach has been studied for the Nuclear Technology National Direction. Hydrodynamic models simulation has been introduced as work methodology. As well as radiological safety and radioactive material applications in the environmental studies has been evaluated mainly in the conclusions and recommendations in this report. maps.

  8. NMR spectroscopy applied to the eye: Drugs and metabolic studies

    Energy Technology Data Exchange (ETDEWEB)

    Saether, Oddbjoern

    2005-07-01

    NMR spectroscopy has been extensively applied in biomedical research during the last decades. It has proved to be an analytical tool of great value. From being mainly used in chemistry, technological developments have expanded the application of NMR spectroscopy to a great wealth of disciplines. With this method, biochemical information can be obtained by analysing tissue extracts. Moreover, NMR spectroscopy is increasingly employed for pharmacokinetic studies and analysis of biofluids. Technological progress has provided increased sensitivity and resolution in the spectra, which enable even more of the complexity of biological samples to be elucidated. With the implementation of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy in biomedicine, intact tissue samples or biopsies can be investigated. Thus, NMR spectroscopy has an ever-increasing impact in metabolic screening of human samples and in animal models, and methods are also increasingly realised in vivo. The present work, NMR spectroscopy applied to eye research, consists of two main parts. Firstly, the feasibility to monitor fluorinated ophthalmic drugs directly in the eye was assessed. Secondly, HR-MAS H1 NMR spectroscopy was applied for metabolic profiling of the anterior eye segment, specifically to analyse metabolic changes in intact corneal and lenticular samples after cataractogenic insults. This work included metabonomics with the application of pattern recognition methods to analyse HR-MAS spectra of eye tissues. Optimisation strategies were explored for F19 NMR detection of fluorinated drugs in a phantom eye. S/N gains in F19 NMR spectroscopy were achieved by implementing time-share H1 decoupling at 2.35 T. The method is advantageous for compounds displaying broad spectral coupling patterns, though detection of drugs at concentrations encountered in the anterior eye segment after topical application was not feasible. Higher magnetic fields and technological improvements could enable

  9. NMR spectroscopy applied to the eye: Drugs and metabolic studies

    International Nuclear Information System (INIS)

    Saether, Oddbjoern

    2005-01-01

    NMR spectroscopy has been extensively applied in biomedical research during the last decades. It has proved to be an analytical tool of great value. From being mainly used in chemistry, technological developments have expanded the application of NMR spectroscopy to a great wealth of disciplines. With this method, biochemical information can be obtained by analysing tissue extracts. Moreover, NMR spectroscopy is increasingly employed for pharmacokinetic studies and analysis of biofluids. Technological progress has provided increased sensitivity and resolution in the spectra, which enable even more of the complexity of biological samples to be elucidated. With the implementation of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy in biomedicine, intact tissue samples or biopsies can be investigated. Thus, NMR spectroscopy has an ever-increasing impact in metabolic screening of human samples and in animal models, and methods are also increasingly realised in vivo. The present work, NMR spectroscopy applied to eye research, consists of two main parts. Firstly, the feasibility to monitor fluorinated ophthalmic drugs directly in the eye was assessed. Secondly, HR-MAS H1 NMR spectroscopy was applied for metabolic profiling of the anterior eye segment, specifically to analyse metabolic changes in intact corneal and lenticular samples after cataractogenic insults. This work included metabonomics with the application of pattern recognition methods to analyse HR-MAS spectra of eye tissues. Optimisation strategies were explored for F19 NMR detection of fluorinated drugs in a phantom eye. S/N gains in F19 NMR spectroscopy were achieved by implementing time-share H1 decoupling at 2.35 T. The method is advantageous for compounds displaying broad spectral coupling patterns, though detection of drugs at concentrations encountered in the anterior eye segment after topical application was not feasible. Higher magnetic fields and technological improvements could enable

  10. Genome-wide association studies of obesity and metabolic syndrome.

    Science.gov (United States)

    Fall, Tove; Ingelsson, Erik

    2014-01-25

    Until just a few years ago, the genetic determinants of obesity and metabolic syndrome were largely unknown, with the exception of a few forms of monogenic extreme obesity. Since genome-wide association studies (GWAS) became available, large advances have been made. The first single nucleotide polymorphism robustly associated with increased body mass index (BMI) was in 2007 mapped to a gene with for the time unknown function. This gene, now known as fat mass and obesity associated (FTO) has been repeatedly replicated in several ethnicities and is affecting obesity by regulating appetite. Since the first report from a GWAS of obesity, an increasing number of markers have been shown to be associated with BMI, other measures of obesity or fat distribution and metabolic syndrome. This systematic review of obesity GWAS will summarize genome-wide significant findings for obesity and metabolic syndrome and briefly give a few suggestions of what is to be expected in the next few years. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  11. Radionuclides as tracers

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Importance of radioisotopes in medicine is because of their two characteristics: their biological behaviour is identical to their stable counterparts, and because they are radioactive their emissions can be detected by a suitable instrument. All isotopes of iodine will behave in the same way and will concentrate in the thyroid gland. There is no way of detecting the stable, natural iodine in the thyroid gland, but the presence of radioactive iodine can be detected externally in vivo by a detector. Thus, the radioactive iodine becomes a tracer, a sport of a spy, which mimics the behaviour of natural iodine and relays information to a detector. The radioactive tracers are popular because of the ease with which they can be detected in vivo and the fact that the measurement of their presence in the body can be in quantitative terms. The measurement can be very accurate and sensitive. Whenever the measurements can be done in vivo, the information is obtained in dynamic terms, as it is happening, as if the physiological events become transparent

  12. Development of [18F]afatinib as new TKI-PET tracer for EGFR positive tumors

    International Nuclear Information System (INIS)

    Slobbe, Paul; Windhorst, Albert D.; Walsum, Marijke Stigter-van; Schuit, Robert C.; Smit, Egbert F.; Niessen, Heiko G.; Solca, Flavio; Stehle, Gerd; Dongen, Guus A.M.S. van; Poot, Alex J.

    2014-01-01

    Introduction: Afatinib is an irreversible ErbB family blocker that was approved for the treatment of EGFR mutated non-small cell lung cancer in 2013. Positron emission tomography (PET) with fluorine-18 labeled afatinib provides a means to obtain improved understanding of afatinib tumor disposition in vivo. PET imaging with [ 18 F]afatinib may also provide a method to select treatment responsive patients. The aim of this study was to label afatinib with fluorine-18 and evaluate its potential as TKI-PET tracer in tumor bearing mice. Methods: A radiochemically novel coupling, using peptide coupling reagent BOP, was explored and optimized to synthesize [ 18 F]afatinib, followed by a metabolite analysis and biodistribution studies in two clinically relevant lung cancer cell lines, xenografted in nude mice. Results: A reliable [ 18 F]afatinib radiosynthesis was developed and the tracer could be produced in yields of 17.0 ± 2.5% calculated from [ 18 F]F − and >98% purity. The identity of the product was confirmed by co-injection on HPLC with non-labeled afatinib. Metabolite analysis revealed a moderate rate of metabolism, with >80% intact tracer in plasma at 45 min p.i. Biodistribution studies revealed rapid tumor accumulation and good retention for a period of at least 2 hours, while background tissues showed rapid clearance of the tracer. Conclusion: We have developed a method to synthesize [ 18 F]afatinib and related fluorine-18 labeled 4-anilinoquinazolines. [ 18 F]Afatinib showed good stability in vivo, justifying further evaluation as a TKI-PET tracer

  13. Novel tracer for radiation treatment planning

    International Nuclear Information System (INIS)

    Schwarzenboeck, S.; Krause, B.J.; Herrmann, K.; Gaertner, F.; Souvatzoglou, M.; Klaesner, B.

    2011-01-01

    PET and PET/CT with innovative tracers gain increasing importance in diagnosis and therapy management, and radiation treatment planning in radio-oncology besides the widely established FDG. The introduction of [ 18 F]Fluorothymidine ([ 18 F]FLT) as marker of proliferation, [ 18 F]Fluoromisonidazole ([ 18 F]FMISO) and [ 18 F]Fluoroazomycin-Arabinoside ([ 18 F]FAZA) as tracer of hypoxia, [ 18 F]Fluoroethyltyrosine ([ 18 F]FET) and [ 11 C]Methionine for brain tumour imaging, [ 68 Ga]DOTATOC for somatostatin receptor imaging, [ 18 F]FDOPA for dopamine synthesis and radioactively labeled choline derivatives for imaging phospholipid metabolism have opened novel approaches to tumour imaging. Some of these tracers have already been implemented into radio-oncology: Amino acid PET and PET/CT have the potential to optimise radiation treatment planning of brain tumours through accurate delineation of tumour tissue from normal tissue, necrosis and edema. Hypoxia represents a major therapeutic problem in radiation therapy. Hypoxia imaging is very attractive as it may allow to increase the dose in hypoxic tumours potentially allowing for a better tumour control. Advances in hybrid imaging, i.e. the introduction of MR/PET, may also have an impact in radio-oncology through synergies related to the combination of molecular signals of PET and a high soft tissue contrast of MRI as well as functional MRI capabilities. (orig.)

  14. Technetium and rhenium complexes with modified fatty acid ligands 4. Evaluation of two new classes of {sup 99m}Tc-labelled fatty acids as potential tracers for myocardial metabolism imaging

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, A.; Kropp, J.; Deussen, A. [TU Dresden, Medizinische Fakultaet Carl Gustav Carus (Germany); Jung, C.M.; Spies, H.

    2002-01-01

    {sup 99m}Tc-labelled fatty acids were synthesized according to the '3+1' mixed-ligand approach and investigated as potential tracers for myocardial SPECT diagnostics on the model of the isolated guinea pig heart. The results indicate a low but specific myocardial uptake of the {sup 99m}Tc fatty acid derivatives subject to chain length and structure. (orig.)

  15. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

  16. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

  17. Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

    International Nuclear Information System (INIS)

    Watanabe, Y.W.

    1997-01-01

    Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO 2 in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO 2 released from human activities after the industrial era. (author)

  18. Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Y.W. [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

    1997-02-01

    Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO{sub 2} in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO{sub 2} released from human activities after the industrial era. (author)

  19. Use of K360Co(CN)6 and 114mInEDTA tracers determined by liquid scintillators method in hydrogeologic studies

    International Nuclear Information System (INIS)

    Lebecka, J.; Tomza, I.; Trzebicka, B.; Soltyk, W.

    1986-01-01

    The sensitive methods of K 3 60 Co(CN) 6 and 114m InEDTA tracers detection using the measurements by liquid scintillators method were elaborated to broaden the range of their use. The radiochemical separation of radioisotopes from investigated water samples and the measurement of their activity as well as double labelled samples are described. The practical uses of tracers are given. (A.S.)

  20. A Quantitative Study of Oxygen as a Metabolic Regulator

    Science.gov (United States)

    Radhakrishnan, Krishnan; LaManna, Joseph C.; Cabrera, Marco E.

    1999-01-01

    An acute reduction in oxygen (O2) delivery to a tissue is generally associated with a decrease in phosphocreatine, increases in ADP, NADH/NAD, and inorganic phosphate, increased rates of glycolysis and lactate production, and reduced rates of pyruvate and fatty acid oxidation. However, given the complexity of the human bioenergetic system and its components, it is difficult to determine quantitatively how cellular metabolic processes interact to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). Of special interest is the determination of mechanisms relating tissue oxygenation to observed metabolic responses at the tissue, organ, and whole body levels and the quantification of how changes in tissue O2 availability affect the pathways of ATP synthesis and the metabolites that control these pathways. In this study, we extend a previously developed mathematical model of human bioenergetics to provide a physicochemical framework that permits quantitative understanding of O2 as a metabolic regulator. Specifically, the enhancement permits studying the effects of variations in tissue oxygenation and in parameters controlling the rate of cellular respiration on glycolysis, lactate production, and pyruvate oxidation. The whole body is described as a bioenergetic system consisting of metabolically distinct tissue/organ subsystems that exchange materials with the blood. In order to study the dynamic response of each subsystem to stimuli, we solve the ordinary differential equations describing the temporal evolution of metabolite levels, given the initial concentrations. The solver used in the present study is the packaged code LSODE, as implemented in the NASA Lewis kinetics and sensitivity analysis code, LSENS. A major advantage of LSENS is the efficient procedures supporting systematic sensitivity analysis, which provides the basic methods for studying parameter sensitivities (i.e., changes in model behavior due to parameter variation

  1. Nutritional and metabolic changes due the abdominal radiation: experimental study

    International Nuclear Information System (INIS)

    Mucerino, Donato R.; Waitzberg, Dan L.; Campos, Fabio G. de; Melo Auricchio, Maria T. de; Gama-Rodrigues, Joaquim J.; Lima-Goncalves, Ernesto L.

    1995-01-01

    In this study the effects on nutritional status and energetic metabolism due the abdominal irradiation were analysed. Adult male wistar rats (48), were divided in two groups Control (C) and radiated (R). The rats were maintained all time in metabolic cages. the study was done in two periods: period 1 begun at 0 day, were rats adapted to cages and oral diet, had food and water ad libitum. At the day four indirect calorimetric measurements were performed (calorimetry 1). At period 2, group R rats abdominal radiation at a 300 c Gy/day rate, for 5 consecutive days, and group C started a pair-feeding process linked individually to R rats and suffered application to simulated-irradiation. Two other calorimetric measurements (II,III) were performing during period 2. After radiation the last calorimetry was performed (IV). At sacrifice (day 14) blood was collected for determination of hemoglobin, hematocrit, albumin and transferrin. There were no statistical differences among groups C and R during period 1 (p < 0.05). Great reduction in food intake and weight variation were found in period 2, but weight loss was significantly higher in R rats. Nitrogen balance decrease in period 2, but without difference among the groups (p < 0.05). Serum albumin was significantly lower in R rats. Respiratory quotient decreased in both groups during period 2, but rats kept it lower (p < 0.05). The energy expenditure level decreased after radiation in group R. During period 2 total substrate oxidation decreased in R rats. Radiation decrease glucose and protein oxidation. In conclusion, in this study's conditions, radiation produced malnutrition by reducing food intake by bringing weight loss, hypoalbuminemia and decrease nitrogen balance. Radiation was also responsible for a reduction of metabolism, by promoting the fall of energy expenditure. These changes are not only due the anorexia, undoubtful a main factor. (author)

  2. Metabolic Syndrome among Women: A Study from Bursa Turkey

    Directory of Open Access Journals (Sweden)

    Hasan Orhan

    2011-08-01

    Full Text Available AIM: Obesity is one of the risk factors of metabolic syndrome (MetS and its prevalence is rapidly increasing in Turkey. The purpose of this study was to assess the prevalence of MetS and obesity among women aged 20 years and older. METHOD: This is a cross- sectional study, undergone in a primary health care setting in Bursa /Turkey in the year 2008. A total of 807 women were included in the study. Body weight, height, waist circumference, blood pressure, total and HDL cholesterol, fasting plasma glucose and triglyceride levels were measured. Metabolic Syndrome definition was made according to the International Diabetes Federation (IDF criteria. RESULTS: The mean age was 42.713.2 years, 96.4% were married, 50.7% had education of less than 8 years, 93.7% were housewives and 85.3% had a monthly family income of $650 or less. The prevalence of MetS and abdominal obesity were 17.5 % and 87.7% respectively. Those with diabetes mellitus and elevated plasma lipids had increased risk of developing MetS 11.3 and 4.5 times more than those without these situations respectively. The risk of MetS increases with age and increasing BMI. CONCLUSION: Obesity is an alarming risk factor for the development of MetS in our study group. [TAF Prev Med Bull 2011; 10(4.000: 421-432

  3. Measuring serotonin synthesis: from conventional methods to PET tracers and their (pre)clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Anniek K.D.; Waarde, Aren van; Willemsen, Antoon T.M. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Bosker, Fokko J. [University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Luiten, Paul G.M. [University of Groningen, Center for Behavior and Neurosciences, Department of Molecular Neurobiology, Haren (Netherlands); Boer, Johan A. den [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Kema, Ido P. [University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Dierckx, Rudi A.J.O. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

    2011-03-15

    The serotonergic system of the brain is complex, with an extensive innervation pattern covering all brain regions and endowed with at least 15 different receptors (each with their particular distribution patterns), specific reuptake mechanisms and synthetic processes. Many aspects of the functioning of the serotonergic system are still unclear, partially because of the difficulty of measuring physiological processes in the living brain. In this review we give an overview of the conventional methods of measuring serotonin synthesis and methods using positron emission tomography (PET) tracers, more specifically with respect to serotonergic function in affective disorders. Conventional methods are invasive and do not directly measure synthesis rates. Although they may give insight into turnover rates, a more direct measurement may be preferred. PET is a noninvasive technique which can trace metabolic processes, like serotonin synthesis. Tracers developed for this purpose are {alpha}-[{sup 11}C]methyltryptophan ([{sup 11}C]AMT) and 5-hydroxy-L-[{beta}-{sup 11}C]tryptophan ([{sup 11}C]5-HTP). Both tracers have advantages and disadvantages. [{sup 11}C]AMT can enter the kynurenine pathway under inflammatory conditions (and thus provide a false signal), but this tracer has been used in many studies leading to novel insights regarding antidepressant action. [{sup 11}C]5-HTP is difficult to produce, but trapping of this compound may better represent serotonin synthesis. AMT and 5-HTP kinetics are differently affected by tryptophan depletion and changes of mood. This may indicate that both tracers are associated with different enzymatic processes. In conclusion, PET with radiolabelled substrates for the serotonergic pathway is the only direct way to detect changes of serotonin synthesis in the living brain. (orig.)

  4. Voriconazole metabolism is influenced by severe inflammation : a prospective study

    NARCIS (Netherlands)

    Veringa, Anette; ter Avest, Mendy; Span, Lambert F. R.; van den Heuvel, Edwin R.; Touw, Daan J.; Zijlstra, Jan G.; Kosterink, Jos G. W.; van der Werf, Tjip S.; Alffenaar, Jan-Willem C.

    Background: During an infection or inflammation, several drug-metabolizing enzymes in the liver are downregulated, including cytochrome P450 iso-enzymes. Since voriconazole is extensively metabolized by cytochrome P450 iso-enzymes, the metabolism of voriconazole can be influenced during inflammation

  5. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  6. Radon as geological tracer

    International Nuclear Information System (INIS)

    Lacerda, T.; Anjos, R.M.; Silva, A.A.R. da; Yoshimura, E.M.

    2012-01-01

    Full text: This work presents measurements of 222 Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of 40 K, 232 Th and 23 '8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using 222 Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m -3 recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  7. Fractal tracer distributions in turbulent field theories

    DEFF Research Database (Denmark)

    Hansen, J. Lundbek; Bohr, Tomas

    1998-01-01

    We study the motion of passive tracers in a two-dimensional turbulent velocity field generated by the Kuramoto-Sivashinsky equation. By varying the direction of the velocity-vector with respect to the field-gradient we can continuously vary the two Lyapunov exponents for the particle motion and t...