Sample records for tc generators sintesis

  1. TC-1 observations of a flux rope: generation by multiple X line reconnection.

    NASA Astrophysics Data System (ADS)

    Trenchi, Lorenzo; Federica Marcucci, Maria; Rème, Henri; Carr, Christopher M.; Cao, Jinbin

    2010-05-01

    The Flux Transfer Events (FTE) are the manifestation of time-varying reconnection at the Earth magnetopause. The original Russell and Elphic (1978) FTE model predicts a pair of elbow shaped flux ropes of reconnected field lines generated by intermitted and localized reconnection. Alternatively, Lee and Fu (1985) proposes that multiple extended reconnection X lines generate flux ropes at the magnetopause, with the axis roughly aligned to the X lines themselves. On December 29, 2004 the Double Star TC-1 observes several reconnection flow reversals, indicating that the satellite stays close to a reconnection site for about 20 minutes. During the time of observations, TC-1 also detects a flux rope. Because TC-1 observations are made close to the reconnection site, it can be evaluated the direction of the X line as predicted by the component merging model (Sonnerup 1974, Gonzales and Mozer 1974). It is found that the flux rope axis is parallel to such an X line. This fact suggests that the flux rope is probably generated by multiple X lines. The time period under study is characterized by a large and negative Earth dipole tilt and the reconnection line close to TC-1 is found to follow the magnetic equator, passing northward of the subsolar/stagnation point. The interplanetary magnetic field is directed southward and dawnward. Although during the period under study only single point observations are available, the most likely interpretation is that the flux rope is generated when a secondary X line, which has approximately the same orientation of the primary X line near TC-1 and is located south of TC-1 location and passing through the subsolar/stagnation point, is activated.

  2. Generation of parametric images during routine Tc-99m PYP inhalation/Tc-99m MAA perfusion lung scintigraphy. Technical note.

    PubMed

    Miron, S D; Wiesen, E J; Feiglin, D H; Cohen, A M; Bellon, E M

    1991-07-01

    A simple technique is described for generating ventilation/perfusion ratio and perfusion/ventilation ratio images from the posterior Tc-99m PYP aerosol inhalation and Tc-99m MAA perfusion images obtained during routine lung scintigraphy. These images highlight areas of ventilation/perfusion incongruence--mismatch or reverse mismatch--that may sometimes be difficult to detect on conventional images. PMID:1834387

  3. Desorption of 99 Mo from spent 99 Mo\\/ 99m Tc generator

    Microsoft Academic Search

    A. Mushtaq

    1995-01-01

    A simple method for desorption and purification of99Mo from spent99Mo\\/99mTc generators is described. The alumina column was washed successively with 0.9% saline water, 35% H2O2, and then the99Mo was eluted with 2M NH4OH. Ammonia and residual H2O2 were removed by heating the eluate. Finally,99Mo solution was passed through a 0.2 m membrane filter to remove precipitated aluminium hydroxide.

  4. Magnesium-Molybate Compounds as Matrix for 99Mo/99mTc Generators

    PubMed Central

    Monroy-Guzman, Fabiola; Jimenez Martinez, Thania Susana; Arriola, Humberto; Longoria Gandara, Luis Carlos

    2011-01-01

    This work reports the preparation of a 99mTc generator based on conversion of 99Mo produced by neutron irradiation, into insoluble magnesium 99Mo-molybdates compounds as matrix. The effect of magnesium salt types and concentration, Mg:Mo molar ratios, pH of molybdate solutions, eluate volume as well as the addition order of molybdate and magnesium solutions' influences on the final 99mTc were evaluated. Polymetalates and polymolybdates salts either crystallized or amorphous were obtained depending on the magnesium salt and Mg:Mo molar ratio used in matrix preparation. 99Mo/99mTc generator production based on magnesium-99Mo molybdate compounds allow reduction of preparation time and eliminates the use of specialized installations. The best generator performances were attained using matrices prepared from 0.1 mol/L MgCl2·6H2O solutions, ammonium molybdate solutions at pH 7 and at a Mg:Mo molar ratio of 1:1.

  5. Computed tomography image using sub-terahertz waves generated from a high-Tc superconducting intrinsic Josephson junction oscillator

    NASA Astrophysics Data System (ADS)

    Kashiwagi, T.; Nakade, K.; Saiwai, Y.; Minami, H.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y.; Tsujimoto, M.; Yamamoto, T.; Markovi?, B.; Mirkovi?, J.; Klemm, R. A.; Kadowaki, K.

    2014-02-01

    A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-Tc superconductor Bi2Sr2CaCu2O8+? was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

  6. Method for generating a crystalline .sup.99 MoO.sub.3 product and the isolation .sup.99m Tc compositions therefrom

    DOEpatents

    Bennett, Ralph G. (Idaho Falls, ID); Christian, Jerry D. (Idaho Falls, ID); Kirkham, Robert J. (Blackfoot, ID); Tranter, Troy J. (Idaho Falls, ID)

    1998-01-01

    An improved method for producing .sup.99m Tc compositions. .sup.100 Mo metal is irradiated with photons in a particle (electron) accelerator to produce .sup.99 Mo metal which is dissolved in a solvent. A solvated .sup.99 Mo product is then dried to generate a supply of .sup.99 MoO.sub.3 crystals. The crystals are thereafter heated at a temperature which will sublimate the crystals and form a gaseous mixture containing vaporized .sup.99m TcO.sub.3 and vaporized .sup.99m TcO.sub.2 but will not cause the production of vaporized .sup.99 MoO.sub.3. The mixture is then combined with an oxidizing gas to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7. Next, the gaseous stream is cooled to a temperature sufficient to convert the vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing product. The product has high purity levels resulting from the use of reduced temperature conditions and ultrafine crystalline .sup.99 MoO.sub.3 starting materials with segregated .sup.99m Tc compositions therein which avoid the production of vaporized .sup.99 MoO.sub.3 contaminants.

  7. Can Based, Decentralised Payload TM/TC Architecture for Next Generation Satcoms

    NASA Astrophysics Data System (ADS)

    Gunes-Lasnet, S.

    2010-08-01

    This paper addresses the optimisation of telecom satellites payload through the use of efficient standard serial buses, together with decentralised and highly integrated units interfacing payload and local telemetry and telecommands. Such an upgraded architecture is under study and assessment through an extensive breadboarding activity including the prototyping of a CAN solution for telecom satellites. Enablers for such upgrade are available building blocks (CAN IP) and building blocks such as mixed ASIC which relevance is shared by numerous actors, allowing access to TM/TC optimised implementation in the near future.

  8. Enhanced electricity generation by triclosan and iron anodes in the three-chambered membrane bio-chemical reactor (TC-MBCR).

    PubMed

    Song, Jing; Liu, Lifen; Yang, Fenglin; Ren, Nanqi; Crittenden, John

    2013-11-01

    A three-chambered membrane bio-chemical reactor (TC-MBCR) was developed. The stainless steel membrane modules were used as cathodes and iron plates in the middle chamber served as the anode. The TC-MBCR was able to reduce fouling, remove triclosan (TCS) from a synthetic wastewater treatment and enhance electricity generation by ~60% compared with the cell voltage before TCS addition. The TC-MBCR system generated a relatively stable power output (cell voltage ~0.2V) and the corrosion of iron plates contributed to electricity generation together with microbes on iron anode. The permeation flow from anode to cathode chamber was considered important in electricity generation. In addition, the negatively charged cathode membrane and Fe(2+)/Fe(3+) released by iron plates mitigated membrane fouling by approximately 30%, as compared with the control. The removal of COD and total phosphorus was approximately 99% and 90%. The highest triclosan removal rate reached 97.9%. PMID:24001566

  9. (99m)Tc-MIBI imaging for prediction of therapeutic effects of second-generation MDR1 inhibitors in malignant brain tumors.

    PubMed

    Sasajima, Toshio; Shimada, Naoya; Naitoh, Yuichiro; Takahashi, Masataka; Hu, Yi; Satoh, Tomo; Mizoi, Kazuo

    2007-12-15

    The aim of this study was to explore whether (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) is suitable to elucidate multidrug resistance and prediction of potentiation of antitumor agents by second-generation MDR1 inhibitors (PSC833, MS-209) in malignant brain tumors in rat. Malignant tumor cells (RG2 and C6 gliomas, Walker 256 carcinoma) were incubated with low dose vincristine (VCR) to induce multidrug resistance. MTT assay demonstrated a significant increase of surviving fractions in VCR-resistant sublines compared to those of drug-naive cells. Reverse transcriptase polymerase chain reaction revealed higher expression of MDR1 mRNA in VCR-resistant cells than drug-naive cells in each line. Volume distribution (V(d)) of (99m)Tc-MIBI was negatively correlated with MDR1 mRNA expression among drug-naive and VCR-resistant cells. MDR1 inhibitors decreased surviving fractions and increased V(d) of (99m)Tc-MIBI significantly in VCR-resistant sublines, whereas MDR1 mRNA expression was unchanged. These findings indicate that (99m)Tc-MIBI efflux was functionally suppressed by MDR1 inhibitors. Autoradiographic images of (99m)Tc-MIBI revealed higher uptake in drug-naive cells at basal ganglia compared with VCR-resistant cells at the opposite basal ganglia of rats. Oral administration of the second-generation MDR1 inhibitors significantly increased (99m)Tc-MIBI accumulation of both tumors. Therapeutic effects of VCR with or without the MDR1 inhibitors were also evaluated autoradiographically using (14)C-methyl-L-methionine ((14)C-Met) and MIB-5 index. (14)C-Met uptake and MIB-5 index of both tumors treated with VCR following the MDR1 inhibitor treatment significantly decreased compared with tumors treated with VCR alone. Analysis of (99m)Tc-MIBI accumulation is considered informative for detecting MDR1-mediated drug resistance and for monitoring the therapeutic effects of MDR1 inhibitors in malignant brain tumors. PMID:17708555

  10. Sintesis Nanozarah Magnet Ferum (III) Oksida dengan Kaedah Acuan Mikroemulsi (Synthesis of Magnetic Nanoparticles of Ferum (III) Oxide by using Microemulsion System as Template)

    Microsoft Academic Search

    CHIU WEE SIONG; SHAHIDAN RADIMAN; R. ABD; M. H. ABDULLAH; KHIEW POI SIM; HUANG NAY MING

    ABSTRAK Sintesis nanozarah magnet ferum oksida secara acuan mikroemulsi dijalankan dalam kajian ini. Sistem mikroemulsi yang terdiri daripada ester sukrosa (SE1670S sebagai surfaktan), heptanol (sebagai ko-surfaktan), larutan akueus hidrazina hidrat (kepekatan yang berlainan) dan FeCl3.6H2O (0.5 M) disediakan. Setelah campuran tersebut dihomogenkan, kation Fe3+ akan diturunkan oleh hidrazina hidrat menjadi mendakan ferum dan pertumbuhan nanozarah ini dikawal oleh mikroemulsi yang

  11. 99Tc-MAS-NMR on a Cationic Framework Material for Trapping TcO{sub 4}{sup –}

    SciTech Connect

    Yu, P.; Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.; Phillips, Brian L.; Casey, William H.

    2010-08-09

    {sup 99}Tc?magic-angle spinning (MAS) NMR spectra show that TcO{sub 4}{sup ?} ions, which are generated by nuclear fission and can contaminate the environment, can be trapped within the channels and cavities of a cationic framework material (see picture). These spectra are among the first {sup 99}Tc?MAS?NMR spectra reported to date, and show that the TcO{sub 4}{sup ?} ions can be efficiently removed from simulated nuclear waste solutions.

  12. {sup 99m}Tc generators for clinical use based on zirconium molybdate gel and (n, gamma) produced {sup 99}Mo: Indian experience in the development and deployment of indigenous technology and processing facilities

    SciTech Connect

    Saraswathy, P.; Dey, A.C.; Sarkar, S.K.; Kothalkar, C.; Naskar, P.; Arjun, G.; Arora, S.S.; Kohli, A.K. [Board of Radiation and Isotope Technology (BRIT), BARC Vashi Complex, Navi Mumbai 400705 (India); Meera, V.; Venugopal, V. [Radiochemistry and Isotope Group, Bhabha Atomic Research Centre (BARC), Mumbai 400085 (India); Ramamoorthy, N. [Division of Physical and Chemical Sciences, International Atomic Energy Agency (IAEA), A-1400 Vienna (Austria)

    2008-07-15

    The Indian pursuit of gel generator technology for {sup 99m}Tc was driven mainly by three considerations, namely, (i) well-established and ease of reliable production of (n, gamma)-based {sup 99}Mo in several tens of GBq quantities in the research reactors in Trombay/Mumbai, India, (ii) need for relatively low-cost alternate technology to replace the solvent (MEK) extraction generator system in use in India since 1970s and (iii) minimize dependency on weekly import of fission-produced {sup 99}Mo raw material required for alumina column generator. Extensive investigations on process standardisation for zirconium molybdate gel (ZMG) led to a steady progress, achieved both in terms of process technology and final performance of {sup 99m}Tc gel generators. The {sup 99m}Tc final product purity from the Indian gel system was comparable to that obtained from the gold-standard alumina column generators. Based on the feasibility established for reliable small-scale production, as well as satisfactory clinical experience with a number of gel generators used in collaborating hospital radiopharmacies, full-fledged mechanised processing facilities for handling up to 150 g of ZMG were set up. The indigenous design and development included setting up of shielded plant facilities with pneumatic-driven as well as manual controls and special gadgets such as, microwave heating of the zirconium molybdate cake, dispenser for gel granules, loading of gel columns into pre-assembled generator housing etc. Formal review of the safety features was carried out by the regulatory body and stage-wise clearance for processing low and medium level {sup 99}Mo activity was granted. Starting from around 70 GBq {sup 99}Mo handling, the processing facilities have since been successfully operated at a level of 740 GBq {sup 99}Mo, twice a month. In all 18 batches of gel have been processed and 156 generators produced. The individual generator capacity was 15 to 30 GBq with an elution yield of nearly 75%. 129 generators were supplied to 11 user hospitals and the estimated number of clinical studies done is well over 5000. The salient aspects of the Indian experience have been reported in many a forum and shared with the IAEA through the on-going CRP. The detailed process know-how is available for technology transfer from BRIT, India. (author)

  13. What Tc tells

    NASA Astrophysics Data System (ADS)

    Geballe, Theodore H.; Hammond, Robert H.; Wu, Phillip M.

    2015-07-01

    Superconductivity has continued to be a fascinating phenomenon ever since its discovery in 1911. The magnitude of the transition temperature, Tc, provides valuable insight into the underlying physics. Here we provide select examples of the extensive research that has been done towards understanding Tc, and some cases where further investigation is called for. We believe that searching for new and enhanced Tc's remains a fertile frontier.

  14. Measurement of neutron activation cross sections for the [sup 99]Tc(n,p) [sup 99]Mo, [sup 99]Tc(n,[alpha]) [sup 96]Nb, [sup 99]Tc (n,n[prime][alpha]) [sup 95]Nb, and [sup 99]Tc(n,n[prime])[sup 99m]Tc reactions at 13. 5 and 14. 8 MeV

    Microsoft Academic Search

    Y. Ikeda; C. Konno; H. Maekawa; E. T. Cheng

    1994-01-01

    The activation cross sections for the [sup 99]Tc(n,p)[sup 99]Mo, [sup 99]Tc(n,[alpha])[sup 96]Nb, [sup 99]Tc(n,n[prime][alpha])[sup 95]Nb, and [sup 99]Tc(n,n[prime])[sup 99n]Tc reactions at 13.5 and 14.8 MeV have been measured by using the deuterium-tritium neutron generator (the Fusion Neutronics Source) at the Japan Atomic Energy Research Institute. The results were compared with experimental values form the literature, evaluated activation cross-section files, and

  15. Microwave oven drying of zirconium molybdate- 99Mo for use in 99mTc gel generator 1 Presented in part at the DAE\\/BRNS Symposium NUCAR-97, at Saha Institute of Nuclear Physics, Calcutta, India, in January, 1997. 1

    Microsoft Academic Search

    P. Saraswathy; S. K. Sarkar; D. V. S. Narasimhan; R. R. Patel; N. Ramamoorthy

    1999-01-01

    Microwave oven drying of zirconium molybdate-99Mo (Zr99Mo) was investigated for preparing a gel generator for 99mTc and compared with an earlier method standardised by us using hot air for drying. With a microwave frequency of 2.45GHz and power output of 385W, 30g ZrMo gel (i.e. 10g Mo) could be satisfactorily dried for use in a generator in only 35min compared

  16. Sustained availability of 99mTc: possible paths forward.

    PubMed

    Pillai, Maroor Raghavan Ambikalmajan; Dash, Ashutosh; Knapp, F F Russ

    2013-02-01

    The availability of (99m)Tc for single-photon imaging in diagnostic nuclear medicine is crucial, and current availability is based on the (99)Mo/(99m)Tc generator fabricated from fission-based molybdenum (F (99)Mo) produced using high enriched uranium (HEU) targets. Because of risks related to nuclear material proliferation, the use of HEU targets is being phased out and alternative strategies for production of both (99)Mo and (99m)Tc are being evaluated intensely. There are evidently no plans for replacement of the limited number of reactors that have primarily provided most of the (99)Mo. The uninterrupted, dependable availability of (99m)Tc is a crucial issue. For these reasons, new options being pursued include both reactor- and accelerator-based strategies to sustain the continued availability of (99m)Tc without the use of HEU. In this paper, the scientific and economic issues for transitioning from HEU to non-HEU are also discussed. In addition, the comparative advantages, disadvantages, technical challenges, present status, future prospects, security concerns, economic viability, and regulatory obstacles are reviewed. The international actions in progress toward evolving possible alternative strategies to produce (99)Mo or (99m)Tc are analyzed as well. The breadth of technologies and new strategies under development to provide (99)Mo and (99m)Tc reflects both the broad interest in and the importance of the pivotal role of (99m)Tc in diagnostic nuclear medicine. PMID:23255729

  17. The Tribolium castaneum cell line TcA: a new tool kit for cell biology

    PubMed Central

    Silver, Kristopher; Jiang, Hongbo; Fu, Jinping; Phillips, Thomas W.; Beeman, Richard W.; Park, Yoonseong

    2014-01-01

    The red flour beetle, Tribolium castaneum, is an agriculturally important insect pest that has been widely used as a model organism. Recently, an adherent cell line (BCIRL-TcA-CLG1 or TcA) was developed from late pupae of the red flour beetle. Next generation transcriptome sequencing of TcA cells demonstrated expression of a wide variety of genes associated with specialized functions in chitin metabolism, immune responses and cellular and systemic RNAi pathways. Accordingly, we evaluated the sensitivity of TcA cells to dsRNA to initiate an RNAi response. TcA cells were highly sensitive to minute amounts of dsRNA, with a minimum effective dose of 100?pg/mL resulting in significant suppression of gene expression. We have also developed a plasmid containing two TcA-specific promoters, the promoter from the 40S ribosomal protein subunit (TC006550) and a bi-directional heat shock promoter (TcHS70) from the intergenic space between heat shock proteins 68a and b. These promoters have been employed to provide high levels of either constitutive (TC006550) or inducible (TcHS70) gene expression of the reporter proteins. Our results show that the TcA cell line, with its sensitivity to RNAi and functional TcA-specific promoters, is an invaluable resource for studying basic molecular and physiological questions. PMID:25354547

  18. INFLUENCE OF NATURAL AND SYNTHETIC ORGANIC LIGANDS ON THE STABILITY AND MOBILITY OF REDUCED TC(IV)

    SciTech Connect

    Nathalie A. Wall; Baohua Gu

    2012-12-20

    The primary objectives were (1) to quantify the interactions of organic ligands with Tc(IV) through the generation of thermodynamic (complexation) and kinetic parameters needed to assess and predict the mobility of reduced Tc(IV) at DOE contaminated sites; and (2) to determine the impact of organic ligands on the mobility and fate of reduced Tc(IV) under field geochemical conditions.

  19. Superatom representation of high-TC superconductivity

    NASA Astrophysics Data System (ADS)

    Panas, Itai

    2012-10-01

    A “super-atom” conceptual interface between chemistry and physics is proposed in order to assist in the search for higher TC superconductors. The plaquettes generating the checkerboard superstructure in the cuprates, the C60 molecules in K3C60, and the Mo6S82- clusters in Chevrel phase materials offer such candidate super-atoms. Thus, in the present study high-TC superconductivity HTSC is articulated as the entanglement of two disjoint electronic manifolds in the vicinity of a common Fermi energy. The resulting HTSC ground state couples near-degenerate protected local super-atom states to virtual magnons in an antiferromagnetic AFM embedding. The composite Cooper pairs emerge as the interaction particles for virtual magnons mediated “self-coherent entanglement” of super-atom states. A Hückel type resonating valence bond RVB formalism is employed in order to illustrate the real-space Cooper pairs as well as their delocalization and Bose Einstein condensation BEC on a ring of super-atoms. The chemical potential ?BEC for Cooper pairs joining the condensate is formulated in terms of the super-exchange interaction, and consequently the TC in terms of the Neél temperature. A rationale for the robustness of the HTSC ground state is proposed: achieving local maximum “electron correlation entropy” at the expense of non-local phase rigidity.

  20. Evaluation of excitation functions of 100Mo(p,d+pn)99Mo and 100Mo (p,2n)99mTc reactions: Estimation of long-lived Tc-impurity and its implication on the specific activity of cyclotron-produced (99m)Tc.

    PubMed

    Qaim, S M; Sudár, S; Scholten, B; Koning, A J; Coenen, H H

    2014-02-01

    Excitation functions were calculated by the code TALYS for 10 proton-induced reactions on (100)Mo. For (100)Mo(p,d+pn)(99)Mo and (100)Mo(p,2n)(99m)Tc, calculations were also performed using the code STAPRE. Furthermore, for those two reactions and (nat)Mo(p,x)(96)Tc, evaluation of available experimental data was also carried out. The production of (99m)Tc via the (100)Mo(p,2n)-process is discussed. The ratio of atoms of long-lived (99g)Tc and (98)Tc to those of (99m)Tc is appreciably higher in cyclotron production than in generator production of (99m)Tc; this may adversely affect the preparation of (99m)Tc-chelates. PMID:24389533

  1. GASIFICATION TEST RUN TC06

    SciTech Connect

    Southern Company Services, Inc.

    2003-08-01

    This report discusses test campaign TC06 of the Kellogg Brown & Root, Inc. (KBR) Transport Reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). The Transport Reactor was operated as a pressurized gasifier during TC06. Test run TC06 was started on July 4, 2001, and completed on September 24, 2001, with an interruption in service between July 25, 2001, and August 19, 2001, due to a filter element failure in the PCD caused by abnormal operating conditions while tuning the main air compressor. The reactor temperature was varied between 1,725 and 1,825 F at pressures from 190 to 230 psig. In TC06, 1,214 hours of solid circulation and 1,025 hours of coal feed were attained with 797 hours of coal feed after the filter element failure. Both reactor and PCD operations were stable during the test run with a stable baseline pressure drop. Due to its length and stability, the TC06 test run provided valuable data necessary to analyze long-term reactor operations and to identify necessary modifications to improve equipment and process performance as well as progressing the goal of many thousands of hours of filter element exposure.

  2. Mental Health and the TC. Chapter 5.

    ERIC Educational Resources Information Center

    Acampora, Alfonso P., Ed.; Nebelkopf, Ethan, Ed.

    This document contains 19 papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with the interface between the mental health establishments and the TC. Papers include: (1) "Psychiatry and the TC" (Jerome Jaffe); (2) "The Chemical Brain" (Sidney Cohen); (3) "Where Does the TC Fail?" (Ab Koster); (4) "Psychiatric Severity…

  3. Technetium Removal Using Tc-Goethite Coprecipitation

    SciTech Connect

    Um, Wooyong; Wang, Guohui; Jung, Hun Bok; Peterson, Reid A.

    2013-11-18

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Low temperature waste forms coupled with technetium removal using an alternative immobilization process such as Fe(II) treated-goethite precipitation” to increase our understanding of 99Tc long-term stability in goethite mineral form and the process that controls the 99Tc(VII) reduction and removal by the final Fe (oxy)hydroxide forms. The overall objectives of this task were to 1) evaluate the transformation process of Fe (oxy)hydroxide solids to the more crystalline goethite (?-FeOOH) mineral for 99Tc removal and 2) determine the mechanism that limits 99Tc(IV) reoxidation in Fe(II)-treated 99Tc-goethite mineral and 3) evaluate whether there is a long-term 99Tcoxidation state change for Tc sequestered in the iron solids.

  4. /sup 99/Tc vegetation reference material

    SciTech Connect

    Feiner, M.S.

    1984-03-01

    For the past several years participants at the Oak Ridge National Laboratory - Department of Energy Conference on Analytical Chemistry in Energy Technology discussed the need for environmental standards/reference materials for /sup 99/Tc. Past efforts at interlaboratory comparisons of soil, water and vegetation samples for /sup 99/Tc have been unsuccessful. At the urging of many of our colleagues, the Environmental Measurements Laboratory agreed to prepare a /sup 99/Tc vegetation reference material. The sample preparation and the interlaboratory comparison to establish the /sup 99/Tc reference value of 6.55 +- 0.22 pCi/g are described in this report.

  5. Pressure dependence of Tc in superconducting cuprates

    NASA Astrophysics Data System (ADS)

    Tallon, J. L.; Lusk, J.; Presland, M. R.

    1991-03-01

    The pressure dependence of Tc in Tl 0.5Pb 0.5CaSr 2- xLa xCu 2O 7 was measured to 0.4 GPa for x=0 ( Tc=81 K), x=0.2 ( Tc=101 K) and x=0.4 ( Tc=90 K). These compositions span the peak in Tc versus carrier concentration and were chosen to examine the possible role of pressure-induced charge transfer to the superconducting planes. d Tc/d p passes through a minimum at Tc (max) in contrast to the simple charge transfer model for the 1-2-3 and 1-2-4 compositions of the Y/Ba/Cu/O systems for which d Tc/d p should pass through zero at Tc (max). A more complex charge transfer mechanism which allows for redistribution of charge on the CuO 2 plane is discussed in terms of bond valence sums.

  6. Giant electrocaloric effect around Tc.

    PubMed

    Rose, Maimon C; Cohen, R E

    2012-11-01

    We use molecular dynamics with a first-principles-based shell model potential to study the electrocaloric effect (ECE) in lithium niobate, LiNbO(3), and find a giant electrocaloric effect along a line passing through the ferroelectric transition. With an applied electric field, a line of maximum ECE passes through the zero field ferroelectric transition, continuing along a Widom line at high temperatures with increasing fields, and along the instability that leads to homogeneous ferroelectric switching below T(c) with an applied field antiparallel to the spontaneous polarization. This line is defined as the minimum in the inverse capacitance under an applied electric field. We investigate the effects of pressure, temperature and an applied electric field on the ECE. The behavior we observe in LiNbO(3) should generally apply to ferroelectrics; we therefore suggest that the operating temperature for refrigeration and energy scavenging applications should be above the ferroelectric transition region to obtain a large electrocaloric response. The relationship between T(c), the Widom line, and homogeneous switching should be universal among ferroelectrics, relaxors, multiferroics, and the same behavior should be found under applied magnetic fields in ferromagnets. PMID:23215332

  7. Tc-99 Ion Exchange Resin Testing

    SciTech Connect

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  8. Quantitative simultaneous In-111/Tc-99m planar imaging in a long-bone infection phantom

    NASA Astrophysics Data System (ADS)

    Zhu, Xuping; Park, Mi-Ae; Gerbaudo, Victor H.; Moore, Stephen C.

    2007-12-01

    In-111-white-blood-cell and Tc-99m-sulfur-colloid dual-radionuclide imaging are frequently utilized in the evaluation of patients with suspected osteomyelitis. We have developed a quantitative planar imaging method in which Tc-99m and In-111 scans are acquired simultaneously in accurate spatial registration. Long, thin tubes containing only In-111 or Tc-99m were first imaged in a list mode within a water bath inclined with respect to the water surface; from these, 12 energy spectra corresponding to different Tc/In ratios were synthesized. Triple-energy-window (TEW) parameters for scatter and radionuclide crosstalk correction, including scatter windows and weights, were optimized using 100 noise realizations of each of the spectra (1200 total). A long-bone phantom containing a simulated infection site was then imaged in water with five In/Tc ratios; 100 noise realizations of two conjugate-view images were generated from each acquisition (500 total). Two regions of interest (ROIs) were defined, and the ratio of In/Tc count ratios in these two ROIs was evaluated with and without the TEW scatter correction and geometric mean attenuation compensation. The average bias improved from 17.2% to 5.3%, with comparable precision. TEW corrections with non-optimized but practical energy windows also improved the bias to 6.4%. Compared with subjective visual assessment, quantitation of In-111/Tc-99m ratios may improve diagnostic accuracy and could eventually permit grading of osteomyelitis.

  9. VizieR Online Data Catalog: Tc IV, Tc V and Tc VI oscillator strengths (Werner+, 2015)

    NASA Astrophysics Data System (ADS)

    Werner, K.; Rauch, T.; Kucas, S.; Kruk, J. W.

    2015-01-01

    The discovery of technetium (Tc) in the atmospheres of red giants by Merrill (1952ApJ...116...21M) constituted convincing proof that s-process nucleosynthesis is indeed occurring in evolved stars. In principle, Tc should still be present in the atmospheres of hot post-AGB stars and (pre-) white dwarfs although, due to radioactive decay, it should be present in decreasing quantities along post-AGB evolution. The recent discovery of a large number of trans-iron group elements in hot white dwarfs with atomic numbers in the range A=30-56 (Zn to Ba) raises the prospect that Tc (A=43) may also be detected. However, this is currently not feasible because no atomic data exist for ionization stages beyond TcII. As an initial step, we calculated atomic energy levels and oscillator strengths of Tc IV-VI and used these data to compute non-local thermodynamic equilibrium (NLTE) model atmospheres to estimate at which minimum abundance level Tc could be detected. We show that Tc lines can be found in ultraviolet spectra of hot white dwarfs provided Tc is as abundant as other detected trans-Fe elements. We find that radiative levitation can keep Tc in large, easily detectable quantities in the atmosphere. A direct identification of Tc lines is still not feasible because wavelength positions cannot be computed with necessary precision. Laboratory measurements are necessary to overcome this problem. Our results suggest that such efforts are beneficial to the astrophysical community. (6 data files).

  10. Power Systems Development Facility Gasification Test Campaing TC14

    SciTech Connect

    Southern Company Services

    2004-02-28

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device (PCD), advanced syngas cleanup systems, and high pressure solids handling systems. This report details test campaign TC14 of the PSDF gasification process. TC14 began on February 16, 2004, and lasted until February 28, 2004, accumulating 214 hours of operation using Powder River Basin (PRB) subbituminous coal. The gasifier operating temperatures varied from 1760 to 1810 F at pressures from 188 to 212 psig during steady air blown operations and approximately 160 psig during oxygen blown operations.

  11. Tc-99m Labeled carrier for imaging

    DOEpatents

    Henze, Eberhard (Santa Monica, CA)

    1984-01-01

    Novel radionuclide imaging agents, having particular application for lymphangiography are provided by non-covalently binding Tc-99m to a pharmaceutically acceptable cross-linked polysaccharide. Upon injection of the Tc-99m labeled polysaccharide into the blood stream, optimum contrast can be obtained within one hour.

  12. Oxidative dissolution potential of biogenic and abiogenic TcO{sub 2} in subsurface sediments.

    SciTech Connect

    Fredrickson, J. K.; Zachara, J. M.; Plymale, A. E.; Heald, S. M.; McKinley, J. P.; Kennedy, D. W.; Liu, C.; Nachimuthu, P. (X-Ray Science Division); ( PSC-USR); (PNNL)

    2009-04-01

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O{sub 4}{sup -}] and less mobile in the reduced form [Tc(IV)O{sub 2} {center_dot} nH{sub 2}O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site on the Oak Ridge Site. Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Shewanella putrefaciens CN32 reduced Mn(III/IV) oxides and generated Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. After bioreduction and heat-killing, biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO{sub 2}-like phase in both sediments. The biogenic redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular scale speciation of Tc compared to RG. X-ray microprobe, electron microprobe, X-ray absorption spectroscopy, and micro X-ray diffraction were applied to the whole sediment and isolated Tc-containing particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 {micro}m-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass-transfer-limited migration of O{sub 2} into intra-aggregate and intraparticle domains where Tc(IV) existed; and the formation of unique, oxidation-resistant, intragrain Tc(IV)-Fe(III) molecular species.

  13. Isotope Effect in High-Tc Superconductors

    NASA Astrophysics Data System (ADS)

    Harshman, Dale; Dow, John; Fiory, Anthony

    2008-03-01

    For high-Tc superconductors in which transition temperatures, Tc, are reduced by doping, the oxygen isotope effect (OIE) coefficient in Tc is shown to increase systematically with the pair-breaking rate and with the valence difference between the substituted and native ions. Moreover, the OIE tends to zero as one approaches optimum (or ideal) stoichiometry at which the quality of the superconducting condensate is maximized. In materials with isovalent substitutions, e.g., Sr for Ba or Zn for Cu in YBCO, the small OIE of the parent compound is magnified, owing to pair-breaking disorder. In materials with heterovalent substitutions, e.g., La or Pr for Ba, where carrier densities are necessarily changed, pair breaking induces a much larger OIE. A seminal case is Pr-doped YBCO, where the decrease in Tc observed with Pr doping arises from pair-breaking caused by Pr-on-Ba-site defects. Without the defects, Tc is invariant, providing strong evidence against phononic mechanisms. The fact that Tc drops when Pr substitutes for Ba, but not for Y, indicates that the superconducting hole condensate resides in the BaO layers, where pair-breaking degrades Tc and dramatically increases the OIE. Superconductive pairing modeled on Coulomb coupling between the hole and the electron layers is shown to resolve the shortcomings in electron-phonon interactions.

  14. Transport coefficients of hadronic matter near Tc.

    PubMed

    Noronha-Hostler, Jacquelyn; Noronha, Jorge; Greiner, Carsten

    2009-10-23

    A hadron resonance gas model including all known particles and resonances with masses m < 2 GeV and an exponentially rising density of Hagedorn states for m > 2 GeV is used to obtain an upper bound on the shear viscosity to entropy density ratio, eta/s approximately 1/(4pi), of hadronic matter near Tc. We found a large trace anomaly and small speed of sound near Tc, which agree well with recent lattice calculations. We comment on the bulk viscosity to entropy density ratio close to Tc. PMID:19905750

  15. Isotope effect in high- Tc superconductors

    NASA Astrophysics Data System (ADS)

    Harshman, Dale R.; Dow, John D.; Fiory, Anthony T.

    2008-01-01

    For high- Tc superconductors in which transition temperatures Tc are reduced by doping, the oxygen isotope effect (OIE) coefficient in Tc is shown to increase systematically with the pair-breaking rate and with the valence difference between the substituted and native ions. Moreover, the OIE in Tc tends to zero as one approaches optimum (or ideal) stoichiometry at which the quality of the superconducting condensate is maximized. In materials with isovalent substitutions, e.g., Sr for Ba or Zn for Cu in YBa2Cu3O7-? , the small OIE of the parent (unsubstituted) compound is magnified owing to pair-breaking disorder. In materials with heterovalent substitutions, e.g., La or Pr for Ba, where carrier densities are necessarily changed, pair breaking induces a much larger OIE. A seminal case is Pr-doped YBa2Cu3O7-? , where data were previously misinterpreted owing to the false assumption that Pr substitutes only for Y. It is now clear, however, that the decrease in Tc observed with Pr doping actually arises from pair breaking caused by Pr-on-Ba-site defects introduced during crystal growth. When PrBa2Cu3O7-? is grown correctly without such defects, Tc remains unchanged (as in the case of most other rare-earth substitutions for Y). Invariance of Tc under a 60% rare-earth mass increase provides strong evidence against phononic pairing mechanisms. The fact that Tc drops when Pr substitutes for Ba but not for Y indicates that the superconducting hole condensate resides in the BaO layers, where pair breaking degrades Tc and dramatically increases the OIE. Superconductive pairing modeled on Coulomb coupling between the hole (BaO) and the electron (CuO2) layers is shown to resolve the serious shortcomings inherent in approaches based on electron-phonon interactions and is found to be generally applicable. Moreover, the OIE in the magnetic penetration depth in alloys is shown to be constant, with degradation of Tc up to 50%, and thus is unrelated to the OIE in Tc .

  16. New high- Tc benchmarks for organic and fullerene superconductors

    SciTech Connect

    Williams, J.M.; Wang, H.H.; Carlson, K.D.; Kini, A.M.; Geiser, U.; Schultz, A.J.; Kwok, W.K.; Welp, U.; Crabtree, G.W.; Fleshler, S. (Argonne National Lab., IL (United States)); Whangbo, M.H. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemistry); Schirber, J.E. (Sandia National Labs., Albuquerque, NM (United States))

    1991-01-01

    Superconductivity in the highest-{Tc} radical-cation ({kappa}-(ET){sub 2}Cu(N(CN){sub 2})X, X=Br ({Tc}=11.6K), X=Cl ({Tc}=12.8 K, 0.3 kbar)) and radical-anion (K{sub x}C{sub 60}({Tc}=18.0 K), Rb{sub x}C{sub 60} ({Tc}=28.6 K)) organic superconductors is discussed. 21 refs., 5 figs.

  17. Tc-Glutathione Complex (Tc -GSH) : Labelling, Chemical Characterization and Biodistribution in Rats

    PubMed Central

    Moretti, J. L.; Weinmann, P.; Senekowitsch-Schmidtke, R.; Ercan, M. T.

    1999-01-01

    The chemical structure of 99mTc-GSH has been estabilished using the 99Tc isotope. Labeling of glutathione with technetium in the presence of stanous chloride gave a high yield result. In a comparative study between 99Tc and 99Tc glutathione, the Tc-GSH complex obtained was purified and characterized by uv, visible spectroscopy, HPLC, Biogel chromatography, mass and NMR spectroscopy. Stoichiometric analysis showed a 2 : 1 molar ratio of GSH/Tc for the reaction. The molecular mass assessed by mass spectroscopy was 727 Da corresponding to an oxo(bis) glutathione technetate. NMR studies demonstrated that each glutathione molecule was coordinated to technetium via cysteinyl sulfur and nitrogen atoms. The biodistribution of the complex was studied in normal rats. Blood clearance was rapid during the first hour involving a biexponential curve ( t1/2 (1) : 50 min, t1/2 (2) : 400 min ). No radioactive accumulation was found in any specific organ except kidney and bladder. All the activity excreted was found unchanged in urine. In conclusion, Tc-GSH displayed an anionic dimer form as GSH-Tc-GSH. We assume that the complex is a tetradentate (2N,2S) complex containing a pentavalent technetium coordinated by two thiol and nitrogen atoms of both GSH ligands, and an apical oxo group. PMID:18475909

  18. Insights into Stabilization of the 99TcVO Core for Synthesis of 99TcVO Compounds

    SciTech Connect

    McGregor, Donna; Burton-Pye, Benjamin P.; Lukens, Wayne W.; Howell, Robertha C.; Francesconi, Lynn C.

    2014-01-01

    Synthesis of technetium-99 (99Tc; t1/2: 2.1 105 years, max: 253 keV) materials is of importance in studies of the nuclear fuel cycle where Tc is a major fission product (6percent thermal yield from 235U and 239Pu), in understanding radioactive tank waste composition, and in identifying 99mTc compounds for nuclear medicine imaging. One of the most useful synthetic starting materials, (NBu4)TcOCl4, is susceptible to disproportionation in water to form TcO4 and TcIV species, especially TcO2 2H2O. This unwanted reaction is especially problematic when working with ligands bearing hard donor atoms, such as oxygen, where the stability with the soft TcV=O3+ core may be low. Polyoxometalates (POMs) are such ligands. They possess defect sites with four hard oxygen atoms and show low (ca. 108) stability constants with transition metals. Tc complexes of POMs are molecular-level models for Tc metal oxide solid-state materials and can provide information on coordination and redox environments of metal oxides that stabilize low-valent Tc. In order to synthesize pure Tc POM complexes [TcVO(1-P2W17O61)]7 (TcVO-1) and [TcVO(2-P2W17O61)]7 (TcVO-2) from (NBu4)TcOCl4, we have identified strategies that minimize formation of TcIV species and optimize the formation of pure TcV species. The parameters that we consider are the amount of ethylene glycol, which is employed as a transfer ligand to prevent hydrolysis of (NBu4)TcOCl4, and the precipitating agent. The TcIV species that contaminates the non-optimized syntheses is likely a TcIV -oxido-bridged dimer [TcIV-(-O)2-TcIV]. We also employ a novel procedure where the 2 ligand is photoactivated and reduced (in the presence of a sacrificial electron donor) to subsequently reduce TcVIIO4 to an isolatable TcVO-2 product that is remarkably free of TcIV.

  19. Decontamination of Ru and Tc bearing effl uents by chemical treatment

    Microsoft Academic Search

    Dayamoy Banerjee; Manjula Anand Rao; Annie Joseph; Ajay Manjrekar; Inderjit Singh; Piaray Kishen Wattal

    2012-01-01

    Ion exchange separation of Cs and Sr from alkaline intermediate level waste (ILW) generated at back-end of nuclear fuel cycle results in downstream effluent containing substantial amounts of Ru and Tc activity. Efforts were made to develop suitable chemical treatment based processes for decontamination of these effluents. Feasibility of using various metal sulphides alone or in combination was examined for

  20. Half Life of {sup 101}Mo and {sup 101}Tc {beta}{sup -}-decay

    SciTech Connect

    Silva, Antonio Carlos O. da; Genezini, Frederico A.; Zamboni, Cibele B.; Zahn, Guilherme S. [Centro do Reator de Pesquisas (CRPq)-Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP). Av. Linneu Prestes, 2242-Cidade Universitaria, Sao Paulo, SP, 05507-000 (Brazil); Cruz, Manoel Tiago F. da [Instituto da Fisica da Universidade de Sao Paulo (IFUSP), Sao Paulo, SP (Brazil)

    2009-06-03

    In this work, the half-lives of the beta-unstable nuclei {sup 101}Mo and {sup 101}Tc were studied using neutron-irradiated samples of {sup 100}Mo to produce {sup 101}Mo which in its turn generates {sup 101}Tc by beta decay. The gamma activity of each sample was followed for 5 consecutive half-lives in steps of 5 minutes. A total of 22 sources were measured and checked for dead-time influence, and the half-lives were obtained by weighted average. The results are statistically incompatible with the tabulated values.

  1. The TM/TC processor study report

    NASA Astrophysics Data System (ADS)

    1984-03-01

    Requirements of a TM/TC Front End Equipment (FEE) for ESA spacecraft, particularly communications spacecraft using conventional and packet command and telemetry systems are specified. Parts necessary to form a comprehensive test system for checking operational spacecraft systems in conjunction with the master test processor and the checkout equipment are described. The use of TM/TC FEE at subsystem integration level, spacecraft system test level and as front end to a ground station operational control center is discussed. A self contained test system, including its digital handling capabilities, microwave measurements, the software, and self checking possibilities were examined.

  2. Radionuclide Generators

    NASA Astrophysics Data System (ADS)

    Rösch, F.; Knapp, F. F. (Russ)

    Radionuclide generator systems continue to play a key role in providing both diagnostic and therapeutic radionuclides for various applications in nuclear medicine, oncology, and interventional cardiology. Although many parent/daughter pairs have been evaluated as radionuclide generator systems, there are a relatively small number of generators, which are currently in routine clinical and research use. Essentially every conceivable approach has been used for parent/separation strategies, including sublimation, thermochromatographic separation, solvent extraction, and adsorptive column chromatography. The most widely used radionuclide generator for clinical applications is the 99Mo/99mTc generator system, but recent years have seen an enormous increase in the use of generators to provide therapeutic radionuclides, which has paralleled the development of complementary technologies for targeting agents for therapy and in the general increased interest in the use of unsealed therapeutic radioactive sources. More recently, use of the 68Ge/68Ga generator is showing great potential as a source of positron-emitting 68Ga for positron emission tomography (PET)/CT imaging. Key advantages for the use of radionuclide generators include reasonable costs, the convenience of obtaining the desired daughter radionuclide on demand, and availability of the daughter radionuclide in high specific activity, no-carrier added form.

  3. Use of Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) to determine hepatic blood flow

    SciTech Connect

    Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.; Hutak, D.P.; Ward, R.E.; Krohn, K.A.

    1984-01-01

    Tc-NGA is a new liver radiopharmaceutical which binds to a hepatocyte-specific membrane receptor. Three characteristics of Tc-NGA can be exploited in the measurement of hepatic blood flow (HBF): 1) ability to alter the affinity of Tc-NGA for its receptor by changing the galactose: albumin ratio; 2) ability to achieve a high specific activity with Tc-99m labeling; and 3) ability to administer a high molar dose of Tc-NGA without physiologic side effects. In addition, kinetic modeling of Tc-NGA dynamic data can provide estimates of hepatic receptor concentration. In experimental studies in young pigs, HBF was determined using two techniques: 1) kinetic modeling of dynamic data using moderate affinity, low specific activity Tc-NGA (Group A, n=12); and 2) clearance (CL) technique using high affinity, high specific activity Tc-NGA (Group B, n=4). In both groups, HBF was determined simultaneously by continuous infusion of indocyanine green (CI-ICG) with hepatic vein sampling. Regression analysis of HBF measurements obtained with the Tc-NGA kinetic modeling technique and the CI-ICG technique (Group A) revealed good correlation between the two techniques (r=0.802, p=0.02). Similarly, HBF determination by the clearance technique (Group B) provided highly accurate measurements when compared to the CI-ICG technique. Hepatic blood flow measurements by the clearance technique (CL-NGA) fell within one standard deviation of the error associated with each CI-ICG HBF measurement (all CI-ICG standard deviations were less than 10%).

  4. TcI/TcII co-infection can enhance Trypanosoma cruzi growth in Rhodnius prolixus

    PubMed Central

    2014-01-01

    Background Rhodnius prolixus is an obligate haematophagous insect and one of the most important vectors of Trypanosoma cruzi, the causative agent of Chagas disease in the Americas. T. cruzi is a highly variable parasite which is not transmitted in the same efficiency by the different triatomine vectors. Because different T. cruzi genotypes are aetiopathologically divergent, further elucidation of the transmission abilities of different Chagas disease vectors is extremely important. Findings In the present study, the growth behaviour of two T. cruzi isolates, MDID/BR/1993/C45 (TcI) and TBRA/BR/1999/JCA3 (TcII), sharing the same microhabitat (intestinal tract) in single and mixed infections, was examined. The distribution patterns and parasite population densities were evaluated at 7, 14 and 21 days after feeding (daf) by quantification of parasites using Neubauer haemocytometric measurements and mini-exon PCR to identify TcI and TcII subpopulations. Parasitic colonization in the small intestine was more successful in the mixed infection model than the single infection models at 21 daf. In the rectal lumen and wall, the growth behaviour of the mixed infection was similar to that of the TcI group, although the total parasite number was lower. In the TcII group, no metacyclic trypomastigote forms were found. PCR analysis of the contents of each dissected region showed different genotype fractions in the mixed infection model, in which TcI seemed to be the predominant isolate. Conclusion The different growth behaviour of the TcI and TcII isolates in single and mixed infection models demonstrated that possibly an intraspecific factor modulates parasitic development in the intestine of R. prolixus. PMID:24593987

  5. Telecom 2-B and 2-C (TC2B and TC2C)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Alvarez, H.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Telecom 2-B and 2-C (TC2B and TC2C) are summarized. These Telecom missions will provide high-speed data link applications, telephone, and television service between France and overseas territories as a follow-on to TC2A. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  6. Anomalous Interactions and Exact Tc in Superconductivity

    NASA Astrophysics Data System (ADS)

    Mattis, Daniel C.

    This theoretical study of superconductivity examines repulsive forces that, surprisingly, favor the BCS paired state. The value of Tc and the pairing symmetry (s-, p-, d-wave) are obtained exactly as eigenvalues in a given sector of a Fredholm integral equation of the second kind.

  7. An evolutionarily mobile antigen receptor variable region gene: Doubly rearranging NAR-TcR genes in sharks

    PubMed Central

    Criscitiello, Michael F.; Saltis, Mark; Flajnik, Martin F.

    2006-01-01

    Distinctive Ig and T cell receptor (TcR) chains define the two major lineages of vertebrate lymphocyte yet similarly recognize antigen with a single, membrane-distal variable (V) domain. Here we describe the first antigen receptor chain that employs two V domains, which are generated by separate VDJ gene rearrangement events. These molecules have specialized “supportive” TcR?V domains membrane-proximal to domains with most similarity to IgNAR V. The ancestral NAR V gene encoding this domain is hypothesized to have recombined with the TRD locus in a cartilaginous fish ancestor >200 million years ago and encodes the first V domain shown to be used in both Igs and TcRs. Furthermore, these data support the view that ?/? TcRs have for long used structural conformations recognizing free antigen. PMID:16549799

  8. Power Systems Development Facility Gasification Test Campaign TC22

    SciTech Connect

    Southern Company Services

    2008-11-01

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC22, the first test campaign using a high moisture lignite from Mississippi as the feedstock in the modified Transport Gasifier configuration. TC22 was conducted from March 24 to April 17, 2007. The gasification process was operated for 543 hours, increasing the total gasification operation at the PSDF to over 10,000 hours. The PSDF gasification process was operated in air-blown mode with a total of about 1,080 tons of coal. Coal feeder operation was challenging due to the high as-received moisture content of the lignite, but adjustments to the feeder operating parameters reduced the frequency of coal feeder trips. Gasifier operation was stable, and carbon conversions as high as 98.9 percent were demonstrated. Operation of the PCD and other support equipment such as the recycle gas compressor and ash removal systems operated reliably.

  9. Tc-99m PYP localization in calf muscle necrosis.

    PubMed

    Virupannavar, S; Shirazi, P H; Khedkar, N V; Kaplan, E

    1984-05-01

    Tc-99m pyrophosphate (PYP) can localize in an acute myocardial infarct and other extraosseous lesions, including soft tissue necrosis and severe cellular injury A case of Tc-99m PYP uptake in calf muscle necrosis following transfemoral cardiac catheterization is presented. This was incidentally detected on Tc-99m PYP imaging performed for an acute myocardial infarction. Repeat Tc-99m PYP imaging one month later was normal, implying resolution of the ischemic muscle necrosis. PMID:6086203

  10. Myocardial uptake of Tc-99m-tetrofosmin and Tc-99m-MIBI

    SciTech Connect

    Valkema, R.; Jong, M. de; Reijs, A. [University Hospital Dijkzigt, Rotterdam (Netherlands)] [and others

    1996-05-01

    Tc-99m-tetrofosmin is an alternative for Tc-99m-MIBI as myocardial perfusion tracer, with easier kit preparation and less liver activity. Dual isotope simultaneous acquisition (DISA) SPECT using Tc-99m-MIBI and 18-FDG is a promising technique for the assessment of myocardial viability. Disturbing scatter from 511 keV photons in the 140 keV channel can be minimized with an activity ratio 18-FDG to Tc-99m-MIBI for DISA, the relative myocardial uptake of both tracers was investigated in neonatal rat myocytes (in medium with 0.2% BSA at 37{degrees}C during 60 min, measurements in triplicate) and in 6 patients at rest, who underwent myocardial perfusion scintigraphy for the evaluation of coronary artery disease. Rest SPECT (high resolution parallel collimators, 360{degrees}, 3{degrees} per step of 30 sec) was performed at least 1 hr after the injection of 370 MBq Tc-99m-tetrofosmin. Rest SPECT with 370 MBq Tc-99m-MIBI was repeated 1 week later. Counts in a fixed circular ROI around the heart in the raw projection images from 40{degrees} RAO to 90{degrees} left lateral were compared for tetrofosmin and MIBI, while images with overlying intestinal or liver activity were omitted. In the rat myocytes the cell associated activity of Tc-99m- MIBI was 0.9 {plus_minus} 0.02% D/10 {mu}g protein after 5 min, 4.73 {plus_minus} 0.09% at 10 min, and 8.76 {plus_minus} 0.19% at 60 min. The cell activity of Tc-99m-tetrofosmin was 0.36 {plus_minus} 0.04% at 10 min, 1.96 {plus_minus} 0.22% at 30 min, and 3.89 {plus_minus} 0.47% at 60 min. The MIBI/tetrofosmin ratio was 2.3 {plus_minus} 0.1. In 3 patients all 41 projection images could be evaluated, in 2 patients 36 images, and in 1 patient only 22. The average counts per ROI ranges from 8577 to 16341 for MIBI and from 8088 to 15375 for tetrofosmin. The individual MIBI/tetrofosmin ratios ranges from 0.97 {plus_minus} 0.03 to 1.31 {plus_minus} 0.04. In vitro, the retention of Tc-99m-MIBI is twice that of Tc-99m-tetrofosmin.

  11. Shock compaction of high- Tc superconductors

    SciTech Connect

    Weir, S.T.; Nellis, W.J.; McCandless, P.C.; Brocious, W.F. (Lawrence Livermore National Lab., CA (USA)); Seaman, C.L.; Early, E.A.; Maple, M.B. (California Univ., San Diego, La Jolla, CA (USA). Dept. of Physics); Kramer, M.J. (Ames Lab., IA (USA)); Syono, Y.; Kikuchi, M. (Tohoku Univ., Sendai (Japan))

    1990-09-01

    We present the results of shock compaction experiments on high-{Tc} superconductors and describe the way in which shock consolidation addresses critical problems concerning the fabrication of high J{sub c} bulk superconductors. In particular, shock compaction experiments on YBa{sub 2}Cu{sub 3}O{sub 7} show that shock-induced defects can greatly increase intragranular critical current densities. The fabrication of crystallographically aligned Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} samples by shock-compaction is also described. These experiments demonstrate the potential of the shock consolidation method as a means for fabricating bulk high-{Tc} superconductors having high critical current densities.

  12. Velocity renormalization in high-{Tc} cuprates

    SciTech Connect

    Weger, M. [Hebrew Univ. of Jerusalem (Israel). Racah Inst. of Physics

    1994-12-31

    The authors consider a low-density electron-gas (r{sub s} {approx} 10--16) imbedded in a highly dispersive medium ({var_epsilon}{sub 0}/{var_epsilon}{sub {infinity}} > 10). They find that the Fermi velocity is greatly enhanced over the single-particle value. This enhancement occurs only very close to the Fermi surface, within an energy range smaller than {omega}{sub 0}, the characteristic frequency of the dispersion. This theory applies to high-{Tc} cuprates, as well as to several other systems. It accounts for the highly-anomalous transport properties in the normal state. They believe that it also accounts for the high value of {Tc}, based on the standard phonon-mediated interaction BCS theory. There exist some experimental indications for a greatly-enhanced Fermi velocity in YBa{sub 2}Cu{sub 3}O{sub 7}.

  13. Synthesis of trevorite to capture Tc

    SciTech Connect

    Tsui, Colin

    2011-09-02

    Spinel containing technetium can be used to prevent Tc volatilization during vitrification of radioactive waste. Spinel dissolves in glass at elevated temperatures. This study focuses on the synthesis of spinel and the retention of rhenium, a nonradioactive surrogate for Tc in the crystals. To produce trevorite, a nickel-iron spinel (NiFe2O4), Fe and Ni nitrates were mixed with alkali nitrates along with Al(OH)3 and heated to 500 to 800°C. The trevorite content in samples (up to 40 mass%) was measured with x-ray diffraction. Viable samples were rerun with KReO4. Scanning electron microscopy-energy dispersive spectroscopy detected that Re became partly immobilized in spinel-forming crystals.

  14. Theory of high-TC superconductivity: transition temperature

    NASA Astrophysics Data System (ADS)

    Harshman, Dale R.; Fiory, Anthony T.; Dow, John D.

    2011-07-01

    It is demonstrated that the transition temperature (TC) of high-TC superconductors is determined by their layered crystal structure, bond lengths, valency properties of the ions, and Coulomb coupling between electronic bands in adjacent, spatially separated layers. Analysis of 31 high-TC materials (cuprates, ruthenates, ruthenocuprates, iron pnictides, organics) yields the universal relationship for optimal compounds, kBTC0 = ?/??, where ? is related to the mean spacing between interacting charges in the layers, ? is the distance between interacting electronic layers, ? is a universal constant and TC0 is the optimal transition temperature (determined to within an uncertainty of ± 1.4 K by this relationship). Non-optimum compounds, in which sample degradation is evident, e.g. by broadened superconducting transitions and diminished Meissner fractions, typically exhibit reduced TC < TC0. It is shown that TC0 may be obtained from an average of the Coulomb interaction forces between the two layers.

  15. Telecom 2-A (TC2A)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Latour, J.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Telecom 2-A (TC2A) are summarized. The Telecom 2-A will provide high-speed data link applications, telephone, and television service between France and overseas territories. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  16. New Tc-99m brain imaging agents

    SciTech Connect

    Kung, H.F.; Yu, C.C.; Billings, J.; Molnar, M.; Wicks, R.; Blau, M.

    1984-01-01

    In developing new Tc-99m brain perfusion imaging agents for SPECT, a series of BAT (bis-aminoethanethiol) derivatives was prepared. These N/sub 2/S/sub 2/ ligands formed stable and neutral complexes with reduced Tc-99m, either by Sn(II)-PPi or sodium borohydride reduction. The purity of the Tc-99m complexes was >95% (HPLC reverse-phase column, acetonitrile: pH 7.0 buffer, 85:15). The biodistribution in rats was evaluated using I-125 iodoantipyrine (IAP), a free diffusible tracer, as the internal reference. Compounds with a free hydroxyl group (I and IV) showed lower brain uptake, inspite of high P.C.; this may be related to in vivo instability of the complexes. High initial brain uptake was observed for three compounds (II, III and V), however, only compound V (P.C.=384) showed significant brain retention. Planar imaging with compound V in a monkey demonstrated that the compound localized in brain and the retention time was T/sub 1/2/=35 min. Compounds of this type may be useful as brain imaging agent in themself or as a basis for further structural modification to improve brain uptake and retention.

  17. Mechanisms of conventional and high Tc superconductivity

    SciTech Connect

    Kresin, V.L.; Morawitz, H.; Wolf, S.A.

    1993-12-31

    This book gives a careful and objective review of theories of superconductivity in traditional superconductors, organics, and high Tc cuprates. Of course, the authors do still present their own theories of cuprate superconductivity, but only in the final chapter after other possibilities have been discussed. The book should be especially useful for researchers entering the field of high Tc superconductivity. The reviews of photon mediated pairing and strong coupling theory are very welcome, since much of this material has not been reviewed since the classic 1969 volume edited by Parks. In particular the authors dispel the various myths that phonon mediated pairing leads to upper bounds on Tc. In addition to phonon mediated pairing the book discussed in detail pairing due to exchange of acoustic (demon) plasmons, excitons, or magnetic fluctuations. There have been so many diverse mechanisms based on strong correlation and large U Hubbard models that a book like this can only discuss a limited selection of the main contenders. In particular here the emphasis on Fermi liquid based models no doubt reflects the authors` own point of view. A whole chapter discusses the concepts of induced superconductivity, in the proximity effect, and its application to materials with several different electronic subsystems.

  18. PRETREATMENT OF TC CONTAINING WASTE AND ITS EFFECT ON 99 TC LEACHING FROM GROUTS

    SciTech Connect

    Harbour, J

    2006-12-11

    A salt solution (doped with Tc-99), that simulates the salt waste stream to be processed at the Saltstone Production Facility, was immobilized in grout waste forms with and without (1) ground granulated blast furnace slag and (2) pretreatment with iron salts. The degree of immobilization of Tc-99 was measured through monolithic and crushed grout leaching tests. Although Fe (+2) was shown to be effective in reducing Tc-99 to the +4 state, the strong reducing nature of the blast furnace slag present in the grout formulation dominated the reduction of Tc-99 in the cured grouts. An effective diffusion coefficient of 4.75 x 10{sup -12} (Leach Index of 11.4) was measured using the ANSI/ANS-16.1 protocol. The leaching results show that, even in the presence of a concentrated salt solution, blast furnace slag can effectively reduce pertechnetate to the immobile +4 oxidation state. The measured diffusivity was introduced into a flow and transport model (PORFLOW) to calculate the release of Tc-99 from a Saltstone Vault as a function of hydraulic conductivity of the matrix.

  19. Pretreatment of Tc-Containing Waste and Its Effect on Tc-99 Leaching From Grouts

    SciTech Connect

    Aloy, Albert; Kovarskaya, Elena N. [RosAtom, 'V.G. Khlopin Radium Institute' (KRI), 2-nd Murinsky str., 28, Saint Petersburg, 194021 (Russian Federation); Harbour, John R.; Langton, Christine A.; Holtzscheiter, E. William [Savannah River National Laboratory, Washington Savannah River Company, Aiken, SC 29808 (United States)

    2007-07-01

    A salt solution (doped with Tc-99), that simulates the salt waste stream to be processed at the Saltstone Production Facility, was immobilized in grout waste forms with and without (1) ground granulated blast furnace slag and (2) pretreatment with iron salts. The degree of immobilization of Tc-99 was measured through monolithic and crushed grout leaching tests. Although Fe (+2) was shown to be effective in reducing Tc-99 to the +4 state, the strong reducing nature of the blast furnace slag present in the grout formulation dominated the reduction of Tc-99 in the cured grouts. An effective diffusion coefficient of 4.75 x 10{sup -12} (Leach Index of 11.4) was measured using the ANSI/ANS-16.1 protocol. The leaching results show that, even in the presence of a concentrated salt solution, blast furnace slag can effectively reduce pertechnetate to the immobile +4 oxidation state. The measured diffusivity was introduced into a flow and transport model (PORFLOW) to calculate the release of Tc-99 from a Saltstone Vault as a function of hydraulic conductivity of the matrix. (authors)

  20. Biogeochemical Coupling of Fe and Tc Speciation in Subsurface Sediments: Implications to Long-Term Tc Immobilization

    SciTech Connect

    Jim K. Fredrickson; C. I. Steefel; R. K. Kukkadapu; S. M. Heald

    2006-06-01

    The project has been focused on biochemical processes in subsurface sediments involving Fe that control the valence state, solubility, and effective mobility of 99Tc. Our goal has been to understand the Tc biogeochemistry as it may occur in suboxic and biostimulated subsurface environments. Two objectives have been pursued: (1) To determine the relative reaction rates of 99Tc(VII)O2(aq) with metal reducing bacteria and biogenic Fe(II); and to characterize the identity, structure, and molecular speciation of Tc(IV) products formed through reaction with both biotic and abiotic reductants. (2) To quantify the biogeochemical factors controlling the reaction rate of O2 with Tc(IV)O2?nH2O in sediment resulting from the direct enzymatic reduction of Tc(VII) by DIRB and/or the reaction of Tc(VII) with the various types of biogenic Fe(II) produced by DIRB.

  1. Interdecadal variation of TC frequency in Japan

    NASA Astrophysics Data System (ADS)

    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2014-07-01

    This study analyzed the climate regime shift using statistical change-point analysis on the time-series tropical cyclone (TC) frequency that affected Japan in July to September. The result showed that there was a significant change in 1995, and since then, it showed a trend of rapidly decreasing frequency. To determine the reason for this, differences between 1995 to 2012 (9512) period and 1978 to 1994 (7894) period were analyzed. First, regarding TC genesis, TCs during the 9512 period showed a characteristic of genesis from the southeast quadrant of the tropical and subtropical western North Pacific and TCs during the 7894 period showed their genesis from the northwest quadrant. Regarding a TC track, TCs in the 7894 period had a strong trend of moving from the far east sea of the Philippines via the East China Sea to the mid-latitude region in East Asia while TCs in the 9512 period showed a trend of moving from the Philippines toward the southern part of China westward. Thus, TC intensity in the 7894 period, which can absorb sufficient energy from the sea as they moved a long distance over the sea, was stronger than that of 9512. Large-scale environments were analyzed to determine the cause of such difference in TC activity occurred between two periods. During the 9512 period, anomalous cold and dry anticyclones were developed strongly in the East Asia continent. As a result, Korea and Japan were affected by the anomalous northerlies thereby preventing TCs in this period from moving toward the mid-latitude region in East Asia. Instead, anomalous easterlies (anomalous trade wind) were developed in the tropical western Pacific so that a high passage frequency from the Philippines to the south China region along the anomalous steering flows was revealed. The characteristics of the anomalous cold and dry anticyclone developed in the East Asia continent were also confirmed by the analysis of air temperature, relative humidity, and sensible heat net flux showing that most regions in East Asia had negative values.

  2. Fe(II)- and sulfide-facilitated reduction of 99Tc(VII)O4- in microbially reduced hyporheic zone sediments

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hoon; Zachara, John M.; Fredrickson, James K.; Heald, Steve M.; McKinley, James P.; Plymale, Andrew E.; Resch, Charles T.; Moore, Dean A.

    2014-07-01

    Redox-reactive, biogeochemical phases generated by reductive microbial activity in hyporheic zone sediments from a dynamic groundwater-river interaction zone were evaluated for their ability to reduce soluble pertechnetate [99Tc(VII)O4-] to less soluble Tc(IV). The sediments were bioreduced by indigenous microorganisms that were stimulated by organic substrate addition in synthetic groundwater with or without sulfate. In most treatments, 20 ?mol L-1 initial aqueous Tc(VII) was reduced to near or below detection (3.82 × 10-9 mol L-1) over periods of days to months in suspensions of variable solids concentrations. Native sediments containing significant lithogenic Fe(II) in various phases were, in contrast, unreactive with Tc(VII). The reduction rates in the bioreduced sediments increased with increases in sediment mass, in proportion to weak acid-extractable Fe(II) and sediment-associated sulfide (AVS). The rate of Tc(VII) reduction was first order with respect to both aqueous Tc(VII) concentration and sediment mass, but correlations between specific reductant concentrations and reaction rate were not found. X-ray microprobe measurements revealed a strong correlation between Tc hot spots and Fe-containing mineral particles in the sediment. However, only a portion of Fe-containing particles were Tc-hosts. The Tc-hot spots displayed a chemical signature (by EDXRF) similar to pyroxene. The application of autoradiography and electron microprobe allowed further isolation of Tc-containing particles that were invariably found to be ca 100 ?m aggregates of primary mineral material embedded within a fine-grained phyllosilicate matrix. EXAFS spectroscopy revealed that the Tc(IV) within these were a combination of a Tc(IV)O2-like phase and Tc(IV)-Fe surface clusters, with a significant fraction of a TcSx-like phase in sediments incubated with SO42-. AVS was implicated as a more selective reductant at low solids concentration even though its concentration was below that required for stoichiometric reduction of Tc(VII). These results demonstrate that composite mineral aggregates may be redox reaction centers in coarse-textured hyporheic zone sediments regardless of the dominant anoxic biogeochemical processes.

  3. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced 99mTc yields

    NASA Astrophysics Data System (ADS)

    Tanguay, J.; Hou, X.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2015-05-01

    Cyclotron production of 99mTc through the 100Mo(p,2n) 99mTc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional 99mTc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity 99mTc. However, variations in proton beam currents and the thickness and isotopic composition of enriched 100Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute 99mTc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including 100Mo target thicknesses and proton beam currents, and reproducibility of absolute 99mTc yields (defined as the end of bombardment (EOB) 99mTc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB 99mTc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in 99mTc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of 99mTc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average 1.2, 1.5 and 1.9 times the minimum daily activity requirement. The irradiation parameters that would be required to achieve these service rates are described. We believe the developed formalism will aid in the development of quality-control criteria required to ensure consistent supply of large quantities of high-radionuclidic-purity cyclotron-produced 99mTc.

  4. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced (99m)Tc yields.

    PubMed

    Tanguay, J; Hou, X; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-05-21

    Cyclotron production of (99m)Tc through the (100)Mo(p,2n) (99m)Tc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional (99m)Tc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity (99m)Tc. However, variations in proton beam currents and the thickness and isotopic composition of enriched (100)Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute (99m)Tc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including (100)Mo target thicknesses and proton beam currents, and reproducibility of absolute (99m)Tc yields (defined as the end of bombardment (EOB) (99m)Tc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB (99m)Tc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in (99m)Tc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of (99m)Tc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average 1.2, 1.5 and 1.9 times the minimum daily activity requirement. The irradiation parameters that would be required to achieve these service rates are described. We believe the developed formalism will aid in the development of quality-control criteria required to ensure consistent supply of large quantities of high-radionuclidic-purity cyclotron-produced (99m)Tc. PMID:25909462

  5. Thiolato-technetium complexes. 5. Synthesis, characterization, and electrochemical properties of bis(o-phenylenebis(dimethylarsine))technetium(II) and -technetium(III) complexes with thiolato ligands. Single-crystal structural analyses of trans-(Tc(SCH sub 3 ) sub 2 (DIARS) sub 2 )PF sub 6 and trans-(Tc(SC sub 6 H sub 5 ) sub 2 (DIARS) sub 2 ) sup 0

    SciTech Connect

    Konno, Takumi; Heineman, W.R.; Deutsch, E.; Kirchhoff, J.R. (Univ. of Cincinnati, OH (United States)); Heeg, M.J.; Stuckey, J.A. (Wayne State Univ., Detroit, MI (United States))

    1992-04-01

    Three different thiols have been brought into reaction with trans-(Tc(OH)(O)(DIARS){sub 2}){sup 2+} to produce initially the Tc(II) complex, (Tc(SR){sub 2}(DIARS){sub 2}){sup 0}, which can be oxidized to the Tc(III) complex, (Tc(SR){sub 2}(DIARS){sub 2}){sup +} (DIARS = o-phenylenebis(dimethylarsine)). In the case of SR = SCH{sub 3} and SCH{sub 2}C{sub 6}H{sub 5}, the Tc(II) and Tc(III) products were found to be in the trans geometry, while for SR = SC{sub 6}H{sub 5}, both cis and trans isomers were generated. Two of the complexes were structurally characterized by X-ray diffraction. trans-(Tc(SCH{sub 3}){sub 2}(DIARS){sub 2})PF{sub 6}, chemical formula TcAs{sub 4}S{sub 2}PF{sub 6}C{sub 22}H{sub 38}, crystallizes in the monoclinic space group. The Tc atom occupies an inversion center. Representative elemental analyses, FAB mass spectra, and visible-UV spectra are reported. Electrochemical and spectroelectrochemical measurements were taken on trans-(Tc(SCH{sub 3}){sub 2}(DIARS){sub 2}){sup +}, trans-(Tc(SCH{sub 2}C{sub 6}H{sub 5}){sub 2}(DIARS){sub 2}){sup +}, and cis-(Tc(SC{sub 6}H{sub 5}){sub 2}(DIARS){sub 2}){sup +}, which exhibit a reversible Tc(III/II) redox couple in the range {minus}0.32 to {minus}0.47 V vs. Ag/AgCl. Another redox couple is present in the range {minus}1.22 to {minus}1.70 V; this is ascribed to Tc(II/I) and is reversible only for SR = SCH{sub 2}C{sub 6}H{sub 5} at 20C. At room temperature, chemically irreversible couples are exhibited at ca. +1.0 V for Tc(IV/III).

  6. Structural Investigation of Technetium-Diphosphonate Complex 99mTc-MDP

    Microsoft Academic Search

    Ling Qiu; Jian-guo Lin; Xue-hai Ju; Xue-dong Gong; Shi-neng Luo

    2011-01-01

    Density functional theory method has been employed to investigate the structures of the prototypical technetium-labeled diphosphonate complex 99mTc-MDP, where MDP represents methylenediphosphonic acid. A total of 14 trial structures were generated by allowing for the geometric, conformational, charge, and spin isomerism. Based on the optimized structures and calculated energies at the B3LYP\\/LANL2DZ level, two stable isomers were determined for the

  7. Magnetoencephalography based on high-Tc superconductivity: a closer look into the brain?

    E-print Network

    Öisjöen, F; Figueras, G A; Chukharkin, M L; Kalabukhov, A; Hedström, A; Elam, M; Winkler, D

    2011-01-01

    Magnetoencephalography (MEG) enables the study of brain activity by recording the magnetic fields generated by neural currents and has become an important technique for neuroscientists in research and clinical settings. Unlike the liquid-helium cooled low-Tc superconducting quantum interference devices (SQUIDs) that have been at the heart of modern MEG systems since their invention, high-Tc SQUIDs can operate with liquid nitrogen cooling. The relaxation of thermal insulation requirements allows for a reduction in the stand-off distance between the sensor and the room-temperature environment from a few centimeters to less than a millimeter, where MEG signal strength is significantly higher. Despite this advantage, high-Tc SQUIDs have only been used for proof-of-principle MEG recordings of well-understood evoked activity. Here we show high-Tc SQUID-based MEG may be capable of providing novel information about brain activity due to the close proximity of the sensor to the head. We have performed single- and two-...

  8. Episodic ataxia and hemiplegia caused by the 8993T->C mitochondrial DNA mutation.

    PubMed

    Craig, K; Elliott, H R; Keers, S M; Lambert, C; Pyle, A; Graves, T D; Woodward, C; Sweeney, M G; Davis, M B; Hanna, M G; Chinnery, P F

    2007-12-01

    The m.8993T-->C MTATP6 mutation of mitochondrial DNA (mtDNA) usually causes mitochondrial disease in childhood, but was recently described in a family with adult onset ataxia and polyneuropathy. Cytochrome c oxidase muscle histochemistry, which is the standard clinical investigation for mitochondrial disease in adults, is usually normal in patients with MTATP6 mutations. This raises the possibility that these cases have been missed in the past. We therefore studied 308 patients with unexplained ataxia and 96 patients with suspected Charcot-Marie-Tooth disease to determine whether the m.8993T-->C MTATP6 mutation is common in unexplained inherited ataxia and/or polyneuropathy. We identified a three-generation family with the m.8993T-->C mutation of mtDNA. One subject had episodic ataxia (EA) and transient hemipareses, broadening the phenotype. However, no further cases were identified in an additional cohort of 191 patients with suspected EA. In conclusion, m.8993T-->C MTATP6 should be considered in patients with unexplained ataxia, CMT or EA, but cases are uncommon. PMID:18055910

  9. High Tc superconducting materials and devices

    NASA Technical Reports Server (NTRS)

    Haertling, Gene H.

    1990-01-01

    The high Tc Y1Ba2Cu3O(7-x) ceramic materials, initially developed in 1987, are now being extensively investigated for a variety of engineering applications. The superconductor applications which are presently identified as of most interest to NASA-LaRC are low-noise, low thermal conductivity grounding links; large-area linear Meissner-effect bearings; and sensitive, low-noise sensors and leads. Devices designed for these applications require the development of a number of processing and fabrication technologies. Included among the technologies most specific to the present needs are tapecasting, melt texturing, magnetic field grain alignment, superconductor/polymer composite fabrication, thin film MOD (metal-organic decomposition) processing, screen printing of thick films, and photolithography of thin films. The overall objective of the program was to establish a high Tc superconductivity laboratory capability at NASA-LaRC and demonstrate this capability by fabricating superconducting 123 material via bulk and thin film processes. Specific objectives include: order equipment and set up laboratory; prepare 1 kg batches of 123 material via oxide raw material; construct tapecaster and tapecaster 123 material; fabricate 123 grounding link; fabricate 123 composite for Meissner linear bearing; develop 123 thin film processes (nitrates, acetates); establish Tc and Jc measurement capability; and set up a commercial use of space program in superconductivity at LaRC. In general, most of the objectives of the program were met. Finally, efforts to implement a commercial use of space program in superconductivity at LaRC were completed and at least two industrial companies have indicated their interest in participating.

  10. Positron annihilation in high-Tc superconductors

    Microsoft Academic Search

    David Singh; W. E. Pickett; R. E. Cohen; Henry Krakauer; Stephan Berko

    1989-01-01

    We report ab initio calculations of positron wave functions in the high-Tc superconductors YBa2Cu3O7, Bi2Sr2CaCu2O8, and Tl2Ba2CaCu2O8 using the general potential linearized augmented plane-wave method. The calculated positron wave functions are fairly insensitive to whether or not electron-positron correlation is included in the calculation for YBa2Cu3O7 and Tl2Ba2CaCu2O8, but the calculated positron density is quite sensitive to correlation in Bi2Sr2CaCu2O8.

  11. Electromagnetics in high-{Tc} superconductors

    SciTech Connect

    Ma, J.G.; Wolff, I. [Gerhard-Mercator Univ., Duisburg (Germany). Dept. of Electrical Engineering

    1996-04-01

    The behavior of electromagnetic fields in high-{Tc} superconductors (HTS`s) is studied in order to examine their effects in classical electromagnetic boundary value problems. It is shown that an HTS can not be simply treated as a low loss conductor and boundary conditions of HTS`s can not be considered as perfect conducting boundaries like conventional treatments. The electromagnetics of HTS are investigated in terms of complex conductivity, surface impedance with applied magnetic fields, and computational electrodynamics using the new proposed model in Ref. 1.

  12. Doped high- Tc superconductors under pressure

    NASA Astrophysics Data System (ADS)

    Orozco, S.; Ortiz, M. A.; Méndez-Moreno, R. M.; Moreno, M.

    2008-12-01

    Within the BCS framework generalized Fermi surface topologies, modeled with band overlapping, are proposed as a mechanism to enhance the electronic density of states at the Fermi level. This band overlapping allows the high- Tc values observed in cuprate superconductors at different pressures. With this approach the correlation between the critical temperature, the charge carrier density and the pressure is obtained in terms of the coupling constant and the band overlapping parameter. In order to obtain numerical results the model is applied to a Tl-based superconductor.

  13. sup 99m Tc renal tubular function agents: Current status

    SciTech Connect

    Eshima, D.; Fritzberg, A.R.; Taylor, A. Jr. (Emory Univ. School of Medicine, Atlanta, GA (USA))

    1990-01-01

    Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3. 61 references.

  14. Availability of 99Tc in undisturbed soil cores

    Microsoft Academic Search

    Sébastien Denys; Guillaume Echevarria; Louis Florentin; Elisabeth Leclerc-Cessac; Jean-Louis Morel

    2003-01-01

    Models for safety assessment of radioactive waste repositories need accurate values of the soil-to-plant transfer of radionuclides. In oxidizing environments, 99Tc is expected to occur as pertechnetate (99TcO4?). Due to its high mobility, leaching of this element in the field might be important, potentially affecting the reliability of estimated transfer parameters of 99Tc as measured in closed experimental systems such

  15. 99mTc-ciprofloxacin for diagnosis of bacterial infection

    NASA Astrophysics Data System (ADS)

    Aungurarat, A.; Ngamprayad, T.; Dangprasert, M.; Phumkem, S.; Jowanaridhi, B.

    2015-05-01

    Preparation of 99mTc-ciprofloxacin for diagnosis of bacterial infection was investigated by varying factors which affected this compound. The optimum conditions for preparation of 99mTc-ciprofloxacin and a lyophilized kit for Tc-99m labelling were studied. The results from biodistribution study showed that the percentages of the injected dose per gram tissues of infected area at 1 and 3 hours after injection were around 0.25-0.56. 99mTc-ciprofloxacin was found sterile, pyrogen-free and non-toxic. Radiochemical purity was greater than 90% with greater than 6 hours of stability.

  16. 99Tc Process Monitoring System In-Lab Performance Characterization

    SciTech Connect

    O'Hara, Matthew J.; Niver, Cynthia M.

    2014-01-01

    Executive Summary A 99Tc Process Monitoring (Tc-Mon) System has been designed and built for deployment at the recently constructed 200 West Pump & Treat (200W P&T) Plant in the 200 West Area ZP-1 Operable Unit of the Hanford Site. The plant is operated by CH2M Hill Plateau Remediation Company (CHPRC). The Tc-Mon system was created through collaboration between Pacific Northwest National Laboratory (PNNL) and Burge Environmental, Inc. The new system’s design has been optimized based on experience from an earlier field test (2011) of a prototype system at the 200W-ZP-1 Interim Pump & Treat Plant. A portion of the new 200W P&T Plant is dedicated to removal of 99Tc from contaminated groundwater in the 200 West Area. 99Tc, as the pertechnetate anion (99TcO4-), is remediated through delivery of water into two trains (Trains A and B) of three tandem extraction columns filled with Purolite A530E resin. The resin columns cannot be regenerated; therefore, once they have reached their maximum useful capacity, the columns must be disposed of as radioactive waste. The Tc-Mon system’s primary duty will be to periodically sample and analyze the effluents from each of the two primary extraction columns to determine 99Tc breakthrough. The Tc-Mon system will enable the CH2M Hill Plateau Remediation Company (CHPRC) to measure primary extraction column breakthrough on demand. In this manner, CHPRC will be able to utilize each extraction column to its maximum capacity. This will significantly reduce column disposal and replacement costs over the life of the plant. The Tc-Mon system was constructed by Burge Environmental, Inc. and was delivered to PNNL in June 2013 for setup and initial hardware and software performance testing in the 325 Building. By early July, PNNL had initiated an in-laboratory performance characterization study on the system. The objective was to fully calibrate the system and then evaluate the quality of the analytical outputs 1) against a series of clean groundwater samples prepared as 99Tc standards, and 2) on actual 200W P&T Plant grab samples containing 99Tc (and other radioactive and non-radioactive contaminants) at levels reported by the Waste Sampling and Characterization Facility. These grab samples included pre-treated (Pre-Resin) and post-treated (Post-Resin) 200W P&T Plant waters for May through August 2013. This report contains the following information: • The genesis of the 99Tc sensor and the Tc-Mon analytical system. • A description of the Tc-Mon system’s major hardware and software components. • A description of the operational principles behind the 99Tc sensor. • Results from the calibration of three components within the Tc-Mon system. The three systems requiring calibration are: 1. Sampling Chamber 2. Conductivity Sensor 3. 99Tc Sensor • Presentation of analytical results obtained on the fully calibrated Tc-Mon system. This includes a determination of the precision and accuracy of each system defined above. • Estimation of the 99Tc sensor’s minimum detectable activity and limit of quantification. • A brief discussion of potential chemical and radiological influences on the 99Tc sensor based on known contaminants in 200W P&T Plant water. • Observations regarding 99Tc sensor longevity.

  17. Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

    PubMed

    Lima, Valdirene Dos Santos; Xavier, Samanta Cristina das Chagas; Maldonado, Irene Fabíola Roman; Roque, André Luiz Rodrigues; Vicente, Ana Carolina Paulo; Jansen, Ana Maria

    2014-01-01

    Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs) of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i) two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii) five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI) in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil. PMID:25551227

  18. The role of Tc-99m IDA hepatobiliary and Tc-99m colloid hepatic imaging in primary biliary cirrhosis

    SciTech Connect

    Aburano, T.; Yokoyama, K.; Shuke, N.; Kinuya, S.; Takayama, T.; Tonami, N.; Hisada, K. (Kanazawa Univ. Hospital (Japan))

    1991-01-01

    To assess the presence of primary biliary cirrhosis, 15 patients at various histopathologic stages were studied by Tc-99m IDA hepatobiliary and/or Tc-99m colloid hepatic imaging. In the earlier stages (I and II), seven of eight patients (88%) showed uniform hepatic retention of Tc-99m IDA. Of seven patients in the same stage, however, four (57%) showed no abnormality on Tc-99m colliod imaging. In three of these four negative patients (75%), uniform hepatic retention of Tc-99m IDA was noted. In the later stages (III and IV), all seven patients showed decreased clearance with or without delayed tracer appearance in the intestine and prominent hepatic retention on Tc-99m IDA imaging; with Tc-99m colloid imaging there was enlargement of the spleen and increased activity in the spleen and bone marrow. Thus, Tc-99m IDA imaging is considered to be more useful in revealing this functional disorder at the earlier stage of primary biliary cirrhosis and in evaluating progression from an earlier to a later stage of disease. Tc-99m colloid imaging also effectively evaluated progression.

  19. High-Tc superconducting quantum interference device recordings of spontaneous brain activity: Towards high-Tc magnetoencephalography

    NASA Astrophysics Data System (ADS)

    Öisjöen, F.; Schneiderman, J. F.; Figueras, G. A.; Chukharkin, M. L.; Kalabukhov, A.; Hedström, A.; Elam, M.; Winkler, D.

    2012-03-01

    We have performed single- and two-channel high transition temperature (high-Tc) superconducting quantum interference device (SQUID) magnetoencephalography (MEG) recordings of spontaneous brain activity in two healthy human subjects. We demonstrate modulation of two well-known brain rhythms: the occipital alpha rhythm and the mu rhythm found in the motor cortex. We further show that despite higher noise-levels compared to their low-Tc counterparts, high-Tc SQUIDs can be used to detect and record physiologically relevant brain rhythms with comparable signal-to-noise ratios. These results indicate the utility of high-Tc technology in MEG recordings of a broader range of brain activity.

  20. Immobilization of separated Tc and Cs/Sr in Synroc

    SciTech Connect

    Hart, K.P.; Vance, E.R.; Day, R.A.; Begg, B.D.; Angel, P.J.; Jostsons, A. [ANSTO, Menai, New South Wales (Australia)

    1996-08-01

    In some radwaste applications, such as immobilization of Hanford Tank wastes using vitrification, Tc and Cs/Sr are likely to be separated out from HLW supernates. Simplified Synroc preparations can be devised for the immobilization of separated Tc and Cs/Sr, either together or individually. Under suitably reducing processing conditions, Tc can be immobilized as metal or Tc{sup 4}. The volatility of Tc and Cs/Sr in Synroc processing is very restricted. In Synroc-C, designed for Purex high-level reprocessing wastes, Tc exists as a metal alloy. In air-saturated water, normalized MCC-1 type total differential leach rates at 90 C decreased with leaching time and after 90 days were < 10{sup {minus}4} g/m{sup 2}/d, decreasing by a factor of {approximately} 100 in anoxic conditions. The corresponding results in a pH = 6.1 buffer solution were fairly similar to those in deionized water, but in anoxic conditions, the leach rates were higher in the buffer solution than in the deionized water. A single perovskite phase was loaded with ca 40 wt% of TcO{sub 2} to form CaTc{sub 0.5}Ti{sub 0.5}O{sub 3} by a combination of graphite-die hot-pressing and heating in argon. Rutile, intended to be doped with ca 35 wt% TcO{sub 2}, was fabricated by bellows hot-pressing at 1,200 C; approximately 75% of the Tc formed a solid solution with rutile, but some metallic Tc was also present due to imperfect redox control. Results of both MCC-1 and PCT-type leach tests are presented on a preparation containing 70 wt% hollandite + 20 wt% perovskite + 10 wt% rutile containing about 5 wt% of Cs and Sr respectively. Phase distributions resulting from incorporating Cs and Sr in Synroc-B precursor were studied.

  1. Germ-line transgenesis of the Tc1/mariner superfamily transposon Minos in Ciona intestinalis

    PubMed Central

    Sasakura, Yasunori; Awazu, Satoko; Chiba, Shota; Satoh, Nori

    2003-01-01

    The tadpole larva of the basal chordate Ciona intestinalis has the most simplified, basic body-plan of chordates. Because it has a compact genome with a complete draft sequence, a large quantity of EST/cDNA information, and a short generation time, Ciona is a suitable model for future genetics. We establish here a transgenic technique in Ciona that uses the Tc1/mariner superfamily transposon Minos. Minos was integrated efficiently into the genome of germ cells and transmitted stably to subsequent generations. In addition, an enhancer-trap line was obtained. This is a demonstration of efficient, Minos-mediated transgenesis in marine invertebrates. PMID:12788975

  2. Iron Oxide Waste Form for Stabilizing 99Tc

    SciTech Connect

    Um, Wooyong; Chang, Hyun-Shik; Icenhower, Jonathan P.; Lukens, Wayne W.; Serne, R. Jeffrey; Qafoku, Nikolla; Kukkadapu, Ravi K.; Westsik, Joseph H.

    2012-06-09

    Crystals of goethite were synthesized with reduced technetium [{sup 99}Tc(IV)] incorporated within the solid lattice. The presence of {sup 99}Tc(IV) as a substituting cation in the matrix and 'armoring' by an additional layer of precipitated goethite isolated the reduced {sup 99}Tc(IV) from oxidizing agents. These products were used to make monolithic pellets to quantify an effective diffusion coefficient for {sup 99}Tc from goethite waste form contacted with a synthetic Hanford IDF (integrated disposal facility) pore water solution (pH = 7.2, I = 0.05 M) at room temperature for up to 120 days in static reactors. XANES analysis of the goethite solids recovered post-run demonstrated that the {sup 99}Tc in the goethite crystals remains in the reduced {sup 99}Tc(IV) state. The slow release of pertechnetate concentration with time in the static experiments with the monolith followed a square root of time dependence, consistent with diffusion control for {sup 99}Tc release. An apparent diffusion coefficient of 6.15 x 10{sup -11} cm{sup 2}/s was calculated for the {sup 99}Tc-goethite pellet sample and the corresponding leaching index (LI) was 10.2. The results of this study indicate that technetium can be immobilized in a stable, low-cost Fe oxide matrix that is easy to fabricate and these findings can be useful in designing long-term solutions for nuclear waste disposal.

  3. Iron oxide waste form for stabilizing 99Tc

    NASA Astrophysics Data System (ADS)

    Um, Wooyong; Chang, Hyunshik; Icenhower, Jonathan P.; Lukens, Wayne W.; Jeffrey Serne, R.; Qafoku, Nik; Kukkadapu, Ravi K.; Westsik, Joseph H.

    2012-10-01

    Crystals of goethite were synthesized with reduced technetium [99Tc(IV)] incorporated within the solid lattice. The presence of 99Tc(IV) as a substituting cation in the matrix and "armoring" by an additional layer of precipitated goethite isolated the reduced 99Tc(IV) from oxidizing agents. These products were used to make monolithic pellets to quantify an effective diffusion coefficient for 99Tc from goethite waste form contacted with a synthetic Hanford IDF (Integrated Disposal Facility) pore water solution (pH = 7.2 and I = 0.05 M) at room temperature for up to 120 days in static reactors. XANES analysis of the goethite solids recovered post-run demonstrated that the 99Tc in the goethite crystals remains in the reduced 99Tc(IV) state. The slow release of pertechnetate concentration with time in the static experiments with the monolith followed a square root of time dependence, consistent with diffusion control for 99Tc release. An apparent diffusion coefficient of 6.15 × 10-11 cm2/s was calculated for the 99Tc-goethite pellet sample and the corresponding leaching index (LI) was 10.2. The results of this study indicate that technetium can be immobilized in a stable, low-cost Fe oxide matrix that is easy to fabricate and these findings can be useful in designing long-term solutions for nuclear waste disposal.

  4. Analysis of a Mutator Activity Necessary for Germline Transposition and Excision of Tc1 Transposable Elements in Caenorhabditis Elegans

    PubMed Central

    Mori, I.; Moerman, D. G.; Waterston, R. H.

    1988-01-01

    The Tc1 transposable element family of the nematode Caenorhabditis elegans consists primarily of 1.6-kb size elements. This uniformity of size is in contrast to P in Drosophila and Ac/Ds in maize. Germline transposition and excision of Tc1 are detectable in the Bergerac (BO) strain, but not in the commonly used Bristol (N2) strain. A previous study suggested that multiple genetic components are responsible for the germline Tc1 activity of the BO strain. To analyze further this mutator activity, we derived hybrid strains between the BO strain and the N2 strain. One of the hybrid strains exhibits a single locus of mutator activity, designated mut-4, which maps to LGI. Two additional mutators, mut-5 II and mut-6 IV, arose spontaneously in mut-4 harboring strains. This spontaneous appearance of mutator activity at new sites suggests that the mutator itself transposes. The single mutator-harboring strains with low Tc1 copy number generated in this study should be useful in investigations of the molecular basis of mutator activity. As a first step toward this goal, we examined the Tc1 elements in these low copy number strains for elements consistently co-segregating with mutator activity. Three possible candidates were identified: none was larger than 1.6 kb. PMID:2848746

  5. Feasibility studies towards future self-sufficient supply of the 99Mo-99mTc isotopes with Japanese accelerators

    PubMed Central

    NAKAI, Kozi; TAKAHASHI, Naruto; HATAZAWA, Jun; SHINOHARA, Atsushi; HAYASHI, Yoshihiko; IKEDA, Hayato; KANAI, Yasukazu; WATABE, Tadashi; FUKUDA, Mitsuhiro; HATANAKA, Kichiji

    2014-01-01

    In order to establish a self-sufficient supply of 99mTc, we studied feasibilities to produce its parent nucleus, 99Mo, using Japanese accelerators. The daughter nucleus, 99mTc, is indispensable for medical diagnosis. 99Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched 235U fuel. We investigated 99mTc production possibilities based on the following three scenarios: (1) 99Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) 99Mo production by the (p, pn) reaction at Ep = 50–80 MeV proton at the RCNP cyclotron; (3) 99mTc direct production with a 20 MeV proton beam from the PET cyclotron. Among these three scenarios, scenario (1) is for a scheme on a global scale, scenario (2) works in a local area, and both cases take a long time for negotiations. Scenario (3) is attractive because we can use nearly 50 PET cyclotrons in Japan for 99mTc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation. PMID:25504230

  6. Feasibility studies towards future self-sufficient supply of the (99)Mo-(99m)Tc isotopes with Japanese accelerators.

    PubMed

    Nakai, Kozi; Takahashi, Naruto; Hatazawa, Jun; Shinohara, Atsushi; Hayashi, Yoshihiko; Ikeda, Hayato; Kanai, Yasukazu; Watabe, Tadashi; Fukuda, Mitsuhiro; Hatanaka, Kichiji

    2014-01-01

    In order to establish a self-sufficient supply of (99m)Tc, we studied feasibilities to produce its parent nucleus, (99)Mo, using Japanese accelerators. The daughter nucleus, (99m)Tc, is indispensable for medical diagnosis. (99)Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched (235)U fuel. We investigated (99m)Tc production possibilities based on the following three scenarios: (1) (99)Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) (99)Mo production by the (p, pn) reaction at Ep = 50-80 MeV proton at the RCNP cyclotron; (3) (99m)Tc direct production with a 20 MeV proton beam from the PET cyclotron. Among these three scenarios, scenario (1) is for a scheme on a global scale, scenario (2) works in a local area, and both cases take a long time for negotiations. Scenario (3) is attractive because we can use nearly 50 PET cyclotrons in Japan for (99m)Tc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation. PMID:25504230

  7. (47171) 1999 TC36, A Transneptunian Triple

    NASA Astrophysics Data System (ADS)

    Benecchi, Susan D.; Noll, K. S.; Grundy, W. M.; Levison, H. F.

    2009-09-01

    We present new analysis of archival HST images of (47171) 1999 TC36 that confirm it as a triple system. Fits to the point-spread function consistently show that the apparent primary is itself composed of two similar-sized components, A1 and A2. These components can be consistently identified in each of nine epochs spread over seven years of time and observed with two instruments, STIS and ACS/HRC. The orbit of the central pair has a semi-major axis of a 867 km with a period of P 1.9 days. These orbital parameters yield a system mass that is consistent with Msys = 12.75±0.06 1018 kg derived from the orbit of the more distant secondary, component B. The diameters of the three components are dA1=281(+45,-38) km, dA2=258 (+41,-35) km, and dB=135 (+22,-18) km. The relative sizes of these components are more similar than in any other known multiple in the solar system. Taken together, the diameters and system mass yield a bulk density of ?=582 (+317,-211) kg m-3. Photometry shows that component B is variable with an amplitude of > 0.17 ± 0.05 magnitudes. Components A1 and A2 do not show variability larger than 0.02 ± 0.01 magnitudes consistent with the orientation of the mutual orbit plane and tidally-distorted equilibrium shapes. The high specific angular momentum, J/J'=0.92 of the (47171) 1999 TC36 system suggests that it formed by capture rather than collision as has been proposed for the two other multiple systems in the Kuiper Belt. This work was supported under NASA contract NAS 5-26555 and HST programs 11113 and 11178.

  8. Widespread occurrence of the Tc1 transposon family: Tc1-like transposons from teleost fish.

    PubMed

    Radice, A D; Bugaj, B; Fitch, D H; Emmons, S W

    1994-09-28

    We characterized five transposable elements from fish: one from zebrafish (Brachydanio rerio), one from rainbow trout (Salmo gairdneri), and three from Atlantic salmon (Salmo salar). All are closely similar in structure to the Tc1 transposon of the nematode Caenorhabditis elegans. A comparison of 17 Tc1-like transposons from species representing three phyla (nematodes, arthropods, and chordates) showed that these elements make up a highly conserved transposon family. Most are close to 1.7 kb in length, have inverted terminal repeats, have conserved terminal nucleotides, and each contains a single gene encoding similar polypeptides. The phylogenetic relationships of the transposons were reconstructed from the amino acid sequences of the conceptual proteins and from DNA sequences. The elements are highly diverged and have evidently inhibited the genomes of these diverse species for a long time. To account for the data, it is not necessary to invoke recent horizontal transmission. PMID:7969029

  9. Photoreduction of {sup 99}Tc Pertechnetate by Nanometer-Sized Metal Oxides: New Strategies for Formation and Sequestration of Low-Valent Technetium

    SciTech Connect

    Burton-Pye, Benjamin P.; Radivojevic, Ivana; McGregor, Donna; Mbomekalle, Israel M.; Lukens, Jr., Wayne W.; Francesconi, Lynn C.

    2011-07-04

    Technetium-99 ({sup 99}Tc) ({beta}{sup -}{sub max}: 293.7 keV; t{sub 1/2}: 2.1 x 10{sup 5} years) is a byproduct of uranium-235 fission and comprises a large component of radioactive waste. Under aerobic conditions and in a neutral- basic environment, the pertechnetate anion (TcO{sub 4}{sup -}) is stable. TcO{sub 4}{sup -} is very soluble, migrates easily through the environment and does not sorb well onto mineral surfaces, soils or sediments. This study moves forward a new strategy for the reduction of TcO4- and chemical incorporation of the reduced Tc into a metal oxide material. This strategy employs a single material, a polyoxometalate (POM), {alpha}{sub 2}-[P{sub 2}W{sub 17}O{sub 61}]{sup 10-}, that can be photoactivated in the presence of 2-propanol to transfer electrons to TcO{sub 4}{sup -}, and incorporate the reduced Tc covalently into the {alpha}2- framework to form the Tc{sup V}O species, Tc{sup V}O({alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 7-}. This occurs via the formation of an intermediate species that slowly converts to Tc{sup V}O({alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 7-}. EXAFS and XANES analysis and preliminary EPR analysis, suggests that the intermediate consists of a Tc(IV) {alpha}2- species where the Tc is likely bound to only 2 of the 4 W-O oxygen atoms in the {alpha}{sub 2}-[P{sub 2}W{sub 17}O{sub 61}]{sup 10-} defect. This intermediate then oxidizes and converts to the Tc{sup V}O({alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 7-} product. The reduction and incorporation of TcO{sub 4}{sup -} was accomplished in a "one pot" reaction using both sunlight and UV irradiation, and monitored as a function of time using multinuclear NMR and radio TLC. The process was further probed by the "step-wise" generation of reduced {alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}{sup 12-} through bulk electrolysis followed by the addition of TcO{sub 4}{sup -}. The reduction and incorporation of ReO{sub 4}{sup -}, as a non-radioactive surrogate for {sup 99}Tc, does not proceed through the intermediate species, and Re{sup V}O is incorporated quickly into the {alpha}{sub 2}-[P{sub 2}W{sub 17}O{sub 61}]{sup 10-} defect. These observations are consistent with the periodic trends of Tc and Re. Specifically, Tc is more easily reduced compared to Re. In addition to serving as models for metal oxides, POMs may also provide a suitable platform to study the molecular level dynamics and mechanisms of the reduction and incorporation of Tc into a material.

  10. IRES-driven expression of the capsid protein of the Venezuelan equine encephalitis virus TC-83 vaccine strain increases its attenuation and safety.

    PubMed

    Guerbois, Mathilde; Volkova, Eugenia; Forrester, Naomi L; Rossi, Shannan L; Frolov, Ilya; Weaver, Scott C

    2013-01-01

    The live-attenuated TC-83 strain is the only licensed veterinary vaccine available to protect equids against Venezuelan equine encephalitis virus (VEEV) and to protect humans indirectly by preventing equine amplification. However, TC-83 is reactogenic due to its reliance on only two attenuating point mutations and has infected mosquitoes following equine vaccination. To increase its stability and safety, a recombinant TC-83 was previously engineered by placing the expression of the viral structural proteins under the control of the Internal Ribosome Entry Site (IRES) of encephalomyocarditis virus (EMCV), which drives translation inefficiently in insect cells. However, this vaccine candidate was poorly immunogenic. Here we describe a second generation of the recombinant TC-83 in which the subgenomic promoter is maintained and only the capsid protein gene is translated from the IRES. This VEEV/IRES/C vaccine candidate did not infect mosquitoes, was stable in its attenuation phenotype after serial murine passages, and was more attenuated in newborn mice but still as protective as TC-83 against VEEV challenge. Thus, by using the IRES to modulate TC-83 capsid protein expression, we generated a vaccine candidate that combines efficient immunogenicity and efficacy with lower virulence and a reduced potential for spread in nature. PMID:23675542

  11. Measuring functioning hepatocytes using Tc-99m galactosylneoglycoalbumin (Tc-NGA)

    SciTech Connect

    Stadalnik, R.C.; Vera, D.R.; Quadro, R.E.; Krohn, K.A.; Scheibe, P.O.; O'Grady, L.F.

    1984-01-01

    Tc-NGA is a synthetic ligand which binds only to hepatic binding protein (HBP), a receptor found only in the liver. It exhibits the properties of high tissue specificity, affinity-dependent uptake, and dose-dependent uptake. Tc-NGA provides an opportunity to study the functioning hepatocyte. The authors evaluated the usefulness of this technique in patients with hepatitis and hepatoma. After intravenous administration of 5 mCi Tc-NGA, dynamic images were acquired for 30 minutes followed by static views. Estimates of HBP concentrations were obtained by kinetic analysis of blood and liver time-activity curves. Kinetic estimates (reduced chi-squares < 3.0) of HBP correlated well with the clinical course and histology. For example, a patient with hepatoma whose calculated receptor population (functioning hepatocytes) was 3.0 +- 0.9 x 10/sup -7/ mole, which is the normal range, is doing well undergoing chemotherapy. Liver biopsy demonstrated normal liver tissue except for the hepatoma. Another patient with hepatoma who had a severely depressed receptor population, 1.2 +- 0.2 x 10/sup -8/ mole, expired one week after the study. Liver biopsy demonstrated practically no normal tissue. Thus, by means of a complementary, receptor radiopharmaceutical and mathematical model, one should be able to quantitatively follow hepatocyte function and predict response to a therapeutic regimen.

  12. Tc and Re behavior in borosilicate waste glass vapor hydration tests II

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    Technetium (99Tc) is a significant environmental risk factor to consider for nuclear waste disposal repositories. Rhenium (Re), in the same column of the periodic table as Tc, is often used as a non-radioactive surrogate for Tc. Six waste glasses containing both Tc and Re were synthesized under a variety of redox conditions to produce different distributions of Tc and Re oxidation states. These glasses were exposed to vapor hydration tests (VHT) at 200 °C for 23 to 30 days; and the Tc and Re oxidation state, coordination environment, and spatial distribution within the altered coupons were determined. Compared with the original glasses, the corresponding VHT samples showed substantial reduction of Tc species, except where the original glass contained only reduced Tc (Tc4+). Similar to earlier findings, Tc is more sensitive to redox conditions than Re with respect to both glass synthesis conditions and VHT alteration processes. Glasses that originally contained more oxidized Tc (near 100% Tc7+) showed the most Tc enrichment in the altered VHT sample layers, where Tc was largely reduced to Tc4+. Re is generally more oxidized than Tc in the samples measured and has similar spatial distributions as Tc in some VHT samples, while having very different spatial distributions compared with Tc in others. Glasses that originally had a distribution of Tc oxidation states (approximately 1:1 Tc4+ to Tc7+), had Tc concentrations in the VHT altered layers that were approximately equal to or less than those found in the unaltered glass. However, in the same samples, Re concentrations were highest in the altered layers. Overall, with regard to spatial distributions within the altered VHT layers, the behavior of Re was not a good predictor of Tc behavior. Therefore, at least under VHT conditions, using Re as a non-radioactive surrogate for Tc in borosilicate waste glasses can provide misleading results.

  13. Power Systems Development Facility Gasification Test Campaign TC21

    SciTech Connect

    Southern Company Services

    2007-01-30

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coal. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device (PCD), advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of the first demonstration of gasification operation with lignite coal following the 2006 gasifier configuration modifications. This demonstration took place during test campaign TC21, occurring from November 7, 2006, through January 26, 2007. The test campaign began with low sodium lignite fuel, and after 304 hours of operation, the fuel was changed to high sodium lignite, for 34 additional hours of operation. Both fuels were from the North Dakota Freedom mine. Stable operation with low sodium lignite was maintained for extended periods, although operation with high sodium lignite was problematic due to agglomeration formation in the gasifier restricting solids circulation.

  14. Power Systems Development Facility Gasification Test Campaign TC17

    SciTech Connect

    Southern Company Services

    2004-11-30

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR (formerly Kellogg Brown & Root) Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results gasification operation with Illinois Basin bituminous coal in PSDF test campaign TC17. The test campaign was completed from October 25, 2004, to November 18, 2004. System startup and initial operation was accomplished with Powder River Basin (PRB) subbituminous coal, and then the system was transitioned to Illinois Basin coal operation. The major objective for this test was to evaluate the PSDF gasification process operational stability and performance using the Illinois Basin coal. The Transport Gasifier train was operated for 92 hours using PRB coal and for 221 hours using Illinois Basin coal.

  15. Tc-99m glucoheptonate in detection of lung tumors

    SciTech Connect

    Vorne, M.; Sakki, S.; Jaervi, K.; Vaehaetalo, S.

    1982-03-01

    Sixty-three patients aged 21-80 yr were examined. Tc-99m glucoheptonate (Tc-GH) scintigraphy was performed in 32 patients: 26 with primary lung carcinoma; six with metastases in lung, mediastinum, and pleura from carcinomas elsewhere; eight with benign pulmonary diseases; and 23 without known pulmonary disease. Tc-GH accumulated in 23 of 26 primary pulmonary carcinomas as active foci. The specificity of Tc-GH scans for neoplasm detection was higher than that of chest radiographs. The visualization of malignant tumors was much better in the late Tc-GH images (5-6 hr) than in the early (1 hr). Metastases from other carcinomas were positive in four of six patients, but they were considerably better detected in the radiographs, except in one patient with metastatic hepatocellular carcinoma. Neoplasms or their metastases in the hilar and mediastinal regions were better detected in the Tc-GH scans than in the chest radiographs. Only one of eight benign lung processes was visualized (as a weak diffuse accumulation of Tc-GH in hilar scar formation), and 23 patients without pulmonary disease had no pathological foci.

  16. Tc-NGA imaging in liver transplantation: preliminary clinical experience

    SciTech Connect

    Woodle, E.S.; Ward, R.E.; Stadalnik, R.C.; Vera, D.R.

    1989-03-01

    Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) is a new liver imaging agent that binds to hepatic-binding protein, a hepatocyte-specific membrane receptor. The purpose of this study was to determine the potential of Tc-NGA imaging in clinical liver transplantation. A total of 25 studies were performed in nine patients. Imaging studies performed in the early posttransplant period in patients with good hepatic allograft function revealed diffuse patchiness in tracer distribution, a manifestation of preservation damage. Left lobar infarction was demonstrated within a few hours of ischemic injury. Right posterior segmental infarction was seen in another patient. Comparison of kinetic, clinical, and biochemical data revealed good correlation between hepatic allograft function and Tc-NGA kinetics. Major kinetic alterations were noted during periods of preservation injury, hepatic infarction, and acute rejection. These studies indicate: (1) major alterations in Tc-NGA kinetics occur during preservation injury, hepatic infarction, and acute rejection, and (2) Tc-NGA kinetic data appear to provide an accurate reflection of hepatic allograft function. Tc-NGA imaging has the advantages of being noninvasive and of utilizing standard nuclear medicine instrumentation, including portable imaging devices. In conclusion, Tc-NGA imaging provides a promising noninvasive approach for evaluation of liver function in patients undergoing hepatic transplantation.

  17. Interactions of Tc(IV) with humic substances

    SciTech Connect

    Boggs, M. A. [Washington State University; Minton, Travis [Washington State University; Lomasney, Samuel [Washington State University; Islam, Mohammed [Washington State University; Dong, Wenming [ORNL; Gu, Baohua [ORNL; Wall, Nathalie [Washington State University

    2011-01-01

    To understand the key processes affecting 99Tc mobility in the subsurface and help with the remediation of contaminated sites, the binding constants of several humic substances (humic and fulvic acids) with Tc(IV) were determined, using a solvent extraction technique. The novelty of this paper lies in the determination of the binding constants of the complexes formed with the individual species TcO(OH)+ and TcO(OH)20. Binding constants were found to be 6.8 and between 3.9 and 4.3, for log 1, 1,1 and log 1,-2,1, respectively; these values were little modified by a change of ionic strength, in most cases, between 0.1 M to 1.0 M, nor were they by the nature and origin of the humic substances. Modeling calculations based on these show TcO(OH)-HA to be the predominant complex in a system containing 20 ppm HA and in the 4-6 pH range, while TcO(OH)20 and TcO(OH)2-HA are the major species, in the pH 6-8 range.

  18. 99mTc-labeled Therapeutic Inhaled Amikacin Loaded Liposomes

    PubMed Central

    Lee, Jae-Ho; Cheng, Kenneth T.; Malinin, Vladimir; Li, Zhili; Yao, Zhengsheng; Lee, Sung-Jin; Gould, Christine M.; Olivier, Kenneth N.; Chen, Clara; Perkins, Walter R.; Paik, Chang H.

    2014-01-01

    The radiolabeling of the liposome surface can be a useful tool for in vivo tracking of therapeutic drug loaded liposomes. We investigated radiolabeling therapeutic drug (i.e., an antibiotic, amikacin) loaded liposomes with 99mTc, nebulization properties of 99mTc-labeled liposomal amikacin for inhalation (99mTc-LAI), and its stability by size exclusion low pressure liquid chromatography (LPLC). LAI was reacted with 99mTc using SnCl2 dissolved in ascorbic acid as a reducing agent for 10 min at room temperature. The labeled products were then purified by anion exchange resin. The purified 99mTc-LAI in 1.5% NaCl solution was incubated at 4oC to assess its stability by LPLC. The purified 99mTc-LAI was subjected to studies with a clinically used nebulizer (PARI eFlow®) and the Anderson Cascade Impactor (ACI). The use of ascorbic acid at 0.91 mM resulted in a quantitative labeling efficiency. The LPLC profile showed that the liposomal peak of LAI detected by a UV monitor at both 200 nm and 254 nm overlapped with the radioactivity peak of 99mTc-LAI, indicating that 99mTc-LAI is suitable for tracing LAI. The ACI study demonstrated that the aerosol droplet size distribution determined gravimetrically was similar to that determined by radioactivity. The liposome surface labeling method using SnCl2 in 0.91mM ascorbic acid produced 99mTc-LAI with a high labeling efficiency and stability that are adequate to evaluate the deposition and clearance of inhaled LAI in the lung by gamma scintigraphy. PMID:23879241

  19. (99m)Tc-labeled therapeutic inhaled amikacin loaded liposomes.

    PubMed

    Lee, Jae-Ho; Cheng, Kenneth T; Malinin, Vladimir; Li, Zhili; Yao, Zhengsheng; Lee, Sung-Jin; Gould, Christine M; Olivier, Kenneth N; Chen, Clara; Perkins, Walter R; Paik, Chang H

    2013-12-01

    The radiolabeling of the liposome surface can be a useful tool for in vivo tracking of therapeutic drug loaded liposomes. We investigated radiolabeling therapeutic drug (i.e. an antibiotic, amikacin) loaded liposomes with (99m)Tc, nebulization properties of (99m)Tc-labeled liposomal amikacin for inhalation ((99m)Tc-LAI), and its stability by size exclusion low-pressure liquid chromatography (LPLC). LAI was reacted with (99m)Tc using SnCl2 dissolved in ascorbic acid as a reducing agent for 10?min at room temperature. The labeled products were then purified by anion exchange resin. The purified (99m)Tc-LAI in 1.5% NaCl solution was incubated at 4?°C to assess its stability by LPLC. The purified (99m)Tc-LAI was subjected to studies with a clinically used nebulizer (PARI eFlow®) and the Anderson Cascade Impactor (ACI). The use of ascorbic acid at 0.91?mM resulted in a quantitative labeling efficiency. The LPLC profile showed that the liposomal peak of LAI detected by a UV monitor at both 200?nm and 254?nm overlapped with the radioactivity peak of (99m)Tc-LAI, indicating that (99m)Tc-LAI is suitable for tracing LAI. The ACI study demonstrated that the aerosol droplet size distribution determined gravimetrically was similar to that determined by radioactivity. The liposome surface labeling method using SnCl? in 0.91?mM ascorbic acid produced (99m)Tc-LAI with a high labeling efficiency and stability that are adequate to evaluate the deposition and clearance of inhaled LAI in the lung by gamma scintigraphy. PMID:23879241

  20. Re-Search for Extinct 99Tc and 98Tc in the Early Solar System

    NASA Astrophysics Data System (ADS)

    Yin, Q.; Jagoutz, E.; Wanke, H.

    1992-07-01

    The recent advances in negative thermal ionization mass spectrometry (N-TIMS) of Re and Os (Creaser et al., 1991) offer a new chance to search for isotopic anomalies of ruthenium (Ru) (and possibly Mo) in meteorites. The Ru isotopes are particularly important since they contain two daughter decay products of technicium, ^98Tc (tau(sub)1/2=4.2x10^6 yr) and ^99Tc (tau(sub)1/2=2.1x10^5 yr). Natural Tc is now extinct on Earth due to their short half-life, but may have been present in the early solar system; Ru isotopes might also bear witness of the various processes of nucleosynthesis and of the imperfect mixing of their products in the pre-solar nebula; Ru isotopic composition in fission is drastically different from natural; ^99Tc is crucial because of its very short half-life and is observed directly for several half-lives in s-process-enriched stars during the thermally pulsing, AGB (asymptotic giant branch) phase of evolution. The probability of detecting ^99Tc in this type of stars is typically 70% (Smith and Lambert, 1988). The chemical similarities between Ru and Os yield correspondingly high ionization efficiency for Ru with N-TIMS. Ru is obtained as a byproduct of Os chemistry, as Ru co-distills with Os. This unique combination conveniently enables a survey for extinct Tc by determining isotopic composition of Ru on a wide range of samples together with extensive studies of Re-Os system in geochemical community in the years to come. These arguments prompted us to carry out a systematic re-search for Ru isotopic anomalies initiated by Herr and coworkers more than 30 years ago (Herr et al., 1958). We have measured Ru isotopic composition in one bulk sample and a magnetic fraction of Maralinga carbonaceous chondrite and one bulk sample of the iron meteorite Gibeon. The bulk sample of Maralinga is found to be isotopically indistinguishable from the terrestrial values within analytical uncertainties. In the magnetic fraction, however, a positive deviation (0.89+- 0.24epsilon) of the ^99Ru/^101Ru ratio from the terrestrial mean is observed, a first indication that ^99Tc was alive in the early solar system. With the production ratio of ^99Tc/^99Ru=0.75 (Kappeler et al., 1989), a 2.9+-0.2 m.y. time interval (delta) between the nucleosynthetic process and formation of Maralinga is calculated, assuming there is no significant Tc/Ru fractionation since their production. This time interval is consistent with delta>=1.8 m.y. set by ^41Ca (tau(sub)1/2=1.03x10^5 yr) result (Hutcheon et al., 1984) and delta<=~3 m.y. inferred from ^26Al (tau(sub)1/2=7.16x10^5 yr) result (Lee et al., 1977), and gives the most stringent control on delta for the related nucleosynthetic process. The ^99Ru/^101Ru ratio in Gibeon is within error of the laboratory standard value. Since the nucleosynthetic origins of ^107Pd and ^99Tc are similar, the absence of ^99Ru anomaly (^99Ru*) and the presence of ^107Ag* in Gibeon (Chen and Wasserburg, 1990) indicate that core-mantle differentiation in the parent body of Gibeon happened between 2 and 10 m.y. after the nucleosynthetic sources produced these two parent nuclides. In this time span ^26Al was still alive and thus supports the model of ^26Al being a heat source for early planetary differentiation. Chen, J. H. and Wasserburg, G. J. , Geochim. Cosmochim. Acta. (1990) 54, 1729-1743. Creaser, R. A., Papanastassiou, D. A. and Wasserburg, G. J. (1991) Geochim. Cosmochim. Acta. 55, 397-401. Herr, W., Merz, E., Eberhardt, P., Geiss, J., Lang, C. and Signer, P. (1958) Geochim. Cosmochim. Acta. 14, 158. Hutcheon, I. D., Armstrong, J. T., and Wasserburg, G. J. (1984) LPSC XV, 387-388 (abstract). Kappeler, F., Beer, H., and Wisshak, K. (1989) Rep. Prog. Phys. 52. 945-1013. Lee, T., Papanastassiou, D. A. and Wasserburg, G. J. (1977) Astrophys. J. (Letters) 211, L107-L110. Smith, V. V. and Lambert, D. L. (1988)t. Astrophys. J., 333, 219- 226.

  1. High Tc superconducting levitation motor with a laser commutator

    NASA Astrophysics Data System (ADS)

    Weeks, David E.

    1990-01-01

    A high Tc superconducting levitation bearing driven by an optically switched solenoid is described. The bearing uses flux pinning in the new high Tc superconductors for stability. A simple liquid nitrogen supply system is described that greatly improves the ease with which high Tc superconductors can be maintained at 77 K for extended periods of time in small styrofoam dishes. A force versus height curve is given and is used to determine the design limits of the levitation bearing. Alternate motor designs are discussed.

  2. Structural Investigation of Technetium-Diphosphonate Complex 99mTc-MDP

    NASA Astrophysics Data System (ADS)

    Qiu, Ling; Lin, Jian-guo; Ju, Xue-hai; Gong, Xue-dong; Luo, Shi-neng

    2011-06-01

    Density functional theory method has been employed to investigate the structures of the prototypical technetium-labeled diphosphonate complex 99mTc-MDP, where MDP represents methylenediphosphonic acid. A total of 14 trial structures were generated by allowing for the geometric, conformational, charge, and spin isomerism. Based on the optimized structures and calculated energies at the B3LYP/LANL2DZ level, two stable isomers were determined for the title complex. And they were further studied systematically in comparison with the experimental structure. The basis sets 6-31G*(LANL2DZ for Tc), 6-31G*(cc-pVDZ-pp for Tc), and DGDZVP have also been employed in combination with the B3LYP functional to study the basis set effect on the geometries of isomers. The optimized structures agree well with the available experimental data, and the bond lengths are more sensitive to the basis set than the bond angles. The charge distributions were studied by the Mulliken population analysis and natural bond orbital analysis. The results reflect a significant ligand-to-metal electron donation.

  3. Thermodynamic considerations and prediction of the primary coolant activity of 99Tc

    NASA Astrophysics Data System (ADS)

    Lewis, B. J.; Thompson, W. T.; Akbari, F.; Morrison, C.; Husain, A.

    2005-04-01

    A physical model has been developed to describe the coolant activity behaviour of 99Tc, during constant and reactor shutdown operations. This analysis accounts for the fission production of technetium and molybdenum, in which their chemical form and volatility is determined by a thermodynamic treatment using Gibbs-energy minimization. The release kinetics are calculated according to the rate-controlling step of diffusional transport in the fuel matrix and vaporization from the fuel-grain surface. Based on several in-reactor tests with defective fuel elements, and as supported by the thermodynamic analysis, the model accounts for the washout of molybdenum from the defective fuel on reactor shutdown. The model also considers the recoil release of both 99Mo and 99Tc from uranium contamination, as well as a corrosion source due to activation of 98Mo. The model has provided an estimate of the activity ratio 99Tc/ 137Cs in the ion-exchange columns of the Darlington Nuclear Generating Station, i.e., 6 × 10 -6 (following ˜200 days of steady reactor operation) and 4 × 10 -6 (with reactor shutdown). These results are consistent with that measured by the Battelle Pacific Northwest Laboratories with a mixed-bed resin-sampling device installed in a number of Pressurized Water Reactor and Boiling Water Reactor plants.

  4. Germline excision of the transposable element Tc1 in C. elegans.

    PubMed

    Moerman, D G; Kiff, J E; Waterston, R H

    1991-10-25

    We have examined eight germline revertants generated by the excision of Tc1 from a site within the unc-22 gene of Caenorhabditis elegans. A rich variety of rearrangements accompanied Tc1 excision at this site, including transposon 'footprints', deletions of sequences flanking the insertion site and direct nontandem duplications of flanking DNA. With only modest modification the double-strand gap repair model for transposition, recently proposed by Engles and coworkers (Cell 62: 515-525 1990), can explain even the most complex of these rearrangements. In light of this model rearrangements of the target site accompanying transposition/excision may not be the end result of imprecise excision of the element. Instead, these rearrangements may be the result of imprecise repair of the double-strand gap by the host replication and repair machinery. Sequences surrounding an insertion site influence the fidelity of gap repair by this machinery. This may lead to a number of possible resolutions of a double-strand gap as documented here for a Tc1 site in unc-22. PMID:1658738

  5. Applicability of plasmid calibrant pTC1507 in quantification of TC1507 maize: an interlaboratory study.

    PubMed

    Meng, Yanan; Liu, Xin; Wang, Shu; Zhang, Dabing; Yang, Litao

    2012-01-11

    To enforce the labeling regulations of genetically modified organisms (GMOs), the application of DNA plasmids as calibrants is becoming essential for the practical quantification of GMOs. This study reports the construction of plasmid pTC1507 for a quantification assay of genetically modified (GM) maize TC1507 and the collaborative ring trial in international validation of its applicability as a plasmid calibrant. pTC1507 includes one event-specific sequence of TC1507 maize and one unique sequence of maize endogenous gene zSSIIb. A total of eight GMO detection laboratories worldwide were invited to join the validation process, and test results were returned from all eight participants. Statistical analysis of the returned results showed that real-time PCR assays using pTC1507 as calibrant in both GM event-specific and endogenous gene quantifications had high PCR efficiency (ranging from 0.80 to 1.15) and good linearity (ranging from 0.9921 to 0.9998). In a quantification assay of five blind samples, the bias between the test values and true values ranged from 2.6 to 24.9%. All results indicated that the developed pTC1507 plasmid is applicable for the quantitative analysis of TC1507 maize and can be used as a suitable substitute for dried powder certified reference materials (CRMs). PMID:22148678

  6. Research on high Tc superconducting compounds

    NASA Technical Reports Server (NTRS)

    Oliver, Frederick W. (Principal Investigator)

    1996-01-01

    Mossbauer research using the 21.54 kev resonance radiation of Eu-151 on the high temperature superconductors Bi(2)Ca(0.5)Eu(0.5)Sr(2)CU2O(x), and EuBa(2)CU(3)O(7-x) is performed. For the Bismuth compound the Mossbauer measurements gave a weak signal at room temperature but improved at lower temperatures. Experimental data indicated that europium is located at only one crystallographic site. Isomer shift measurements were .69 + 0.02 mm/s with respect to EuF(3). The linewidth at room temperature was found to be 2.54 mm/s. This value falls within the values observed by other researchers on Eu based 1,2,3 high-Tc compounds. Our results also show the Eu to be trivalent with no trace of divalent europium present. Superconducting europium based 1,2,3 compounds were prepared and measurements completed. Our results show the Eu to be trivalent with no trace of divalent europium present. These compounds had an average isomer shift of .73 mm/s +/- O.02 for all samples made. One of these was irradiated with 3.5 X 10(exp 16) neutrons and a comparison made of the Mossbauer parameters for the irradiated and non-irradiated samples. Experimental results showed no difference between linewidths but a measurable effect was seen for the isomer shift.

  7. (??m)Tc-bisphosphonate-iron oxide nanoparticle conjugates for dual-modality biomedical imaging.

    PubMed

    Torres Martin de Rosales, Rafael; Tavaré, Richard; Glaria, Arnaud; Varma, Gopal; Protti, Andrea; Blower, Philip J

    2011-03-16

    The combination of radionuclide-based imaging modalities such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) with magnetic resonance imaging (MRI) is likely to become the next generation of clinical scanners. Hence, there is a growing interest in the development of SPECT- and PET-MRI agents. To this end, we report a new class of dual-modality imaging agents based on the conjugation of radiolabeled bisphosphonates (BP) directly to the surface of superparamagnetic iron oxide (SPIO) nanoparticles. We demonstrate the high potential of BP-iron oxide conjugation using (??m)Tc-dipicolylamine(DPA)-alendronate, a BP-SPECT agent, and Endorem/Feridex, a liver MRI contrast agent based on SPIO. The labeling of SPIOs with (??m)Tc-DPA-alendronate can be performed in one step at room temperature if the SPIO is not coated with an organic polymer. Heating is needed if the nanoparticles are coated, as long as the coating is weakly bound as in the case of dextran in Endorem. The size of the radiolabeled Endorem (??m)Tc-DPA-ale-Endorem) was characterized by TEM (5 nm, Fe?O? core) and DLS (106 ± 60 nm, Fe?O? core + dextran). EDX, Dittmer-Lester, and radiolabeling studies demonstrate that the BP is bound to the nanoparticles and that it binds to the Fe?O? cores of Endorem, and not its dextran coating. The bimodal imaging capabilities and excellent stability of these nanoparticles were confirmed using MRI and nanoSPECT-CT imaging, showing that (??m)Tc and Endorem co-localize in the liver and spleen In Vivo, as expected for particles of the composition and size of (??m)Tc-DPA-ale-Endorem. To the best of our knowledge, this is the first example of radiolabeling SPIOs with BP conjugates and the first example of radiolabeling SPIO nanoparticles directly onto the surface of the iron oxide core, and not its coating. This work lays down the basis for a new generation of SPECT/PET-MR imaging agents in which the BP group could be used to attach functionality to provide targeting, stealth/stability, and radionuclides to Fe?O? nanoparticles using very simple methodology readily amenable to GMP. PMID:21338098

  8. Separation of tc from Uranium and development of metallic Technetium waste forms

    NASA Astrophysics Data System (ADS)

    Mausolf, Edward John

    The isotope Technetium-99 (99Tc) is a major fission product of the nuclear industry. In the last decade, approximately 20 tons of 99Tc have been produced by the US nuclear industry. Due to its long half-life (t1/2 = 214,000 yr), beta radiotoxicity, and high mobility as pertechnetate [TcO4]-, Tc represents long-term concern to the biosphere. Various options have been considered to manage 99Tc. One of them is its separation from spent fuel, conversion to the metal and incorporation into a metallic waste form for long-term disposal. After dissolution of spent fuel in nitric acid and extraction of U and Tc in organic media, previously developed methods can be used to separate Tc from U, convert the separate Tc stream to the metal and reuse the uranium component of the fuel. A variety of metallic waste forms, ranging from pure Tc metal to ternary Tc alloys combined with stainless steel (SS) and Zr are proposed. The goal of this work was to examine three major questions: What is the optimal method to separate Tc from U? After separation, what is the most efficient method to convert the Tc stream to Tc metal? Finally, what is the corrosion behavior of Tc metal, Tc-SS alloys and Tc-Zr-SS alloys in 0.01M NaCl? The goal is to predict the long term behavior of Tc metallic waste in a hypothetical storage environment. In this work, three methods have been used to separate Tc from U: anionic exchange resin, liquid-liquid extraction and precipitation. Of the three methods studied, anionic exchange resins is the most selective. After separation of Tc from U, three different methods were studied to convert the Tc stream to the metal: thermal treatment under hydrogen atmosphere, electrochemical and chemical reduction of pertechnetate in aqueous media. The thermal treatment of the Tc stream under hydrogen atmosphere is the preferred method to produce Tc metal. After Tc metal is isolated, it will be incorporated into a metal host phase. Three different waste forms were produced for corrosion studies in this work: Pure Tc metal, SS(Tc 2 wt%)Zr and SS(Tc 1.34 wt%) alloys. Corrosion rate measurements indicate that both SS(Tc 2 wt%)Zr and SS(Tc 1.34 wt%) alloys corrode more slowly than metallic Tc in the solutions tested.

  9. Sorption of99mTc radiopharmaceutical compounds by soils

    USGS Publications Warehouse

    Jurisson, S.; Gawenis, J.; Landa, E.R.

    2004-01-01

    Study of the sorption of 99mTc radiopharmaceutical compounds by soils has assessed the fate of these compounds in the event of a surface spill and examined the potential of these compounds as hydrologic tracers. Sorption from deionized water, filtered Missouri River water, and artificial seawater by five surface soils was investigated. For all water types, the Tc radiopharmaceutical compounds showed greater sorption than the uncomplexed pertechnetate. The most lipophilic complexes showed the highest sorption on soils.

  10. Availability of 99Tc in undisturbed soil cores.

    PubMed

    Denys, Sébastien; Echevarria, Guillaume; Florentin, Louis; Leclerc-Cessac, Elisabeth; Morel, Jean-Louis

    2003-01-01

    Models for safety assessment of radioactive waste repositories need accurate values of the soil-to-plant transfer of radionuclides. In oxidizing environments, (99)Tc is expected to occur as pertechnetate ((99)TcO(4)(-)). Due to its high mobility, leaching of this element in the field might be important, potentially affecting the reliability of estimated transfer parameters of (99)Tc as measured in closed experimental systems such as hydroponics or pot experiments. The aim of this experiment was to measure the leaching of (99)Tc in undisturbed irrigated soil cores under cultivation as well as plant uptake and to study the possible competition between the two transfer pathways. Undisturbed soil cores (50 x 50 cm) were sampled from a Rendzic Leptosol (R), a colluvial Fluvic Cambisol (F) and a Dystric Cambisol (D) using PVC tubes (three cores sampled per soil type). Each core was equipped with a leachate collector at the bottom, allowing the monitoring of (99)Tc leaching through the cores. Cores were placed in a greenhouse and maize (Zea mays L., cv. DEA, Pioneer) was sown. After 135 d, maize was harvested and radioactivity determined in both plant and water samples. Results showed that during the growing period, leaching of (99)Tc was limited, due to the high evapotranspiration rate of maize. After harvest, leaching of (99)Tc went on because of the absence of evapotranspiration. Effective uptake (EU) of (99)Tc in leaves and grains was calculated. EU reached 70% of the input in the leaves and was not significantly different among soils. These results confirmed those obtained from pot experiments, even though leaching was allowed to occur in close-to-reality hydraulical conditions. As a consequence, it was concluded that pot experiments are an adequate surrogate for more complex "close-to-reality" experimental systems for measuring transfer factors. PMID:12915064

  11. Unusual extraosseous tumoral accumulation of 99m Tc-MDP

    Microsoft Academic Search

    I. Garty; J. Risescu; G. Rosen; I. Bar-Ilan

    1985-01-01

    Three cases (rhabdomyosarcoma, lymphoma, and metastatic malignant melanoma) of unexpected increased uptake of methylenediphosphonate labelled by technetium 99m sodium pertechnetate (99mTc-MDP) are described. The possible mechanisms of the extraosseous tumoral accumulation of 99mTc-MDP in these malignancies are discussed. The usefulness of this method for the diagnosis, localization, and follow-up of some extraosseous tumors is evaluated.

  12. Electron Microscopy Characterization of Tc-Bearing Metallic Waste Forms- Final Report FY10

    SciTech Connect

    Buck, Edgar C.; Neiner, Doinita

    2010-09-30

    The DOE Fuel Cycle Research & Development (FCR&D) Program is developing aqueous and electrochemical approaches to the processing of used nuclear fuel that will generate technetium-bearing waste streams. This final report presents Pacific Northwest National Laboratory (PNNL) research in FY10 to evaluate an iron-based alloy waste form for Tc that provides high waste loading within waste form processing limitations, meets waste form performance requirements for durability and the long-term retention of radionuclides and can be produced with consistent physical, chemical, and radiological properties that meet regulatory acceptance requirements for disposal.

  13. RSA and Elliptic Curve-ElGamal Threshold Cryptography (ECCEG-TC) Implementations for

    E-print Network

    Ertaull, Levent

    RSA and Elliptic Curve- ElGamal Threshold Cryptography (ECCEG-TC) Implementations for Secure Data a promise of securing these networks. In this paper, we discuss our RSA-based Threshold Cryptography (RSA explored possibility of using RSA-TC and ECCEG-TC in MANETs. Finally, we compare RSA-TC and ECCEG

  14. Power Systems Development Facility Gasification Test Run TC07

    SciTech Connect

    Southern Company Services

    2002-04-05

    This report discusses Test Campaign TC07 of the Kellogg Brown & Root, Inc. (KBR) Transport Reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). The Transport Reactor was operated as a pressurized gasifier during TC07. Prior to TC07, the Transport Reactor was modified to allow operations as an oxygen-blown gasifier. Test Run TC07 was started on December 11, 2001, and the sand circulation tests (TC07A) were completed on December 14, 2001. The coal-feed tests (TC07B-D) were started on January 17, 2002 and completed on April 5, 2002. Due to operational difficulties with the reactor, the unit was taken offline several times. The reactor temperature was varied between 1,700 and 1,780 F at pressures from 200 to 240 psig. In TC07, 679 hours of solid circulation and 442 hours of coal feed, 398 hours with PRB coal and 44 hours with coal from the Calumet mine, and 33 hours of coke breeze feed were attained. Reactor operations were problematic due to instrumentation problems in the LMZ resulting in much higher than desired operating temperatures in the reactor. Both reactor and PCD operations were stable and the modifications to the lower part of the gasifier performed well while testing the gasifier with PRB coal feed.

  15. Preservation of Long-Term Memory and Synaptic Plasticity Despite Short-Term Impairments in the Tc1 Mouse Model of Down Syndrome

    ERIC Educational Resources Information Center

    Morice, Elise; Andreae, Laura C.; Cooke, Sam F.; Vanes, Lesley; Fisher, Elizabeth M. C.; Tybulewicz, Victor L. J.; Bliss, Timothy V. P.

    2008-01-01

    Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of the human chromosome 21 (Hsa21). Recently, O'Doherty and colleagues in an earlier study generated a new genetic mouse model of DS (Tc1) that carries an almost complete Hsa21. Since DS is the most common genetic cause of mental retardation, we have undertaken a…

  16. Quaternary borocarbides: Relatively high Tc intermetallic superconductors and magnetic superconductors

    NASA Astrophysics Data System (ADS)

    Mazumdar, Chandan; Nagarajan, R.

    2015-07-01

    Discovery of superconductivity in Y-Ni-B-C (Tc ? 13 K) gave rise to the class of quaternary rare earth transition metal borocarbide superconductors. Before the discovery of Fe-based arsenide superconductors, this was the only class of materials containing a magnetic element, viz., Ni, yet exhibiting Tcs > 5 K. Many members of this class have high Tc (>10 K). Tc of ?23 K in Y-Pd-B-C system equaled the record Tc known then, for intermetallics. Another feature that sets this class apart, is the occurrence of the exotic phenomenon of coexistence of superconductivity and magnetism at temperatures >5 K. Availability of large and electronically 'clean' single crystals and large Ginzburg-Landau (G-L) parameter, ?, have enabled detailed investigation of nonlocal effects of superconductivity. Intermediate value of upper critical field Hc2, has enabled detailed investigation of superconductivity in this class, over the complete H-T plane. This has revealed details of anisotropy of superconductivity (e.g., a fourfold symmetry in the square a-b plane is found) and raised questions on the symmetry of order parameter. After a brief outline of the discovery, this article gives a summary of the materials and highlights of superconducting properties of this class of materials. Interesting results from studies, using various techniques, on YNi2B2C (Tc ? 15 K) and LuNi2B2C (Tc ? 16 K) are presented, including observation of unusual square vortex lattice and its structural transformation with H and T. With conduction electrons involved in the magnetic order of this class of superconductors, the interplay of superconductivity and magnetism is intimate in these magnetic superconductors. With Tc (?11 K) > TN (?6 K) in ErNi2B2C, Tc (?8 K) = TN (?8 K) in HoNi2B2C and Tc (?6 K) < TN (?11 K) in DyNi2B2C, and with other parameters being favorable as mentioned earlier, this class of magnetic superconductors have become ideal materials to investigate the coexistence phenomenon. A few major results on these are presented.

  17. Measurement of Tc distribution in Nb3Sn CICC

    NASA Astrophysics Data System (ADS)

    Calzolaio, Ciro; Bruzzone, Pierluigi; Uglietti, Davide

    2012-05-01

    Knowledge of the actual Nb3Sn filaments’ thermal strain, ?th, in a cable-in-conduit conductor (CICC) is essential to predict the CICC performance in operation starting from the strand scaling laws for the critical current density Jc(B,T,?). To obtain a measurement of ?th under relevant conditions, i.e. at low temperature and with the mechanical constraints of a long length section of CICC, the critical temperature as a function of the applied field, Tc(B), is measured by an inductive method for the CICC in situ and for the freestanding filaments used for the cable manufacture. To deduce the thermal strain in the CICC, the Tc(B) results are compared with the Tc(B,?) curve. Starting from the susceptibility curves measured for both the CICC and the filaments, it is possible to compute the Tc distribution in the CICC using a deconvolution algorithm. The first results of Tc measured on two CICCs in the SULTAN test facility suggest a broad distribution of thermal strain, peaked at negative strain, which remains almost constant during the cyclic loading. From the knowledge of both the thermal strain distribution and the actual CICC performances, it will be possible to discriminate between reversible and irreversible degradation in Nb3Sn CICC.

  18. Iron phosphate glass for immobilization of 99Tc

    NASA Astrophysics Data System (ADS)

    Xu, Kai; Hrma, Pavel; Um, Wooyong; Heo, Jong

    2013-10-01

    Technetium-99 (99Tc) can bring serious environmental threats because of its long half-life (?1/2 = ?2.1 × 105 years), high fission yield (?6%), and high solubility and mobility in the ground water. The high volatility makes it difficult to immobilize 99Tc in continuous melters vitrifying 99Tc-containing nuclear wastes in borosilicate glasses. This work explores a possibility of incorporating a high concentration of 99Tc, surrogated by the non-radioactive Re, in an iron phosphate glass by melting mixtures of iron phosphate glass frits with 1.5-6 mass% KReO4 at ?1000 °C. The retention of Re achieved was ?1.1 mass%. The normalized Re release by the 7-day Product Consistency Test was <10-2 g/m2. Surprisingly, the Re escaped from the melt within a short time of heating, especially when the temperature was increased. Therefore, 99Tc volatilization would still be a challenging task for its immobilization in iron phosphate glasses.

  19. Detection of 99Tc by accelerator mass spectrometry: preliminary investigations

    SciTech Connect

    McAninch, J. E., LLNL

    1997-04-01

    Accelerator mass spectrometry is an established technique for the detection of long-lived radionuclides at environmental levels. At LLNL, planned facility upgrades and advances in detection techniques are allowing us to explore the applicability of AMS to isotopes not previously pursued. One such isotope is technetium-99. We have performed a number of preliminary tests to examine the technical feasibility of AMS for the detection of {sup 99}Tc. The questions addressed were negative ion production in the cesium sputter source, transport efficiency for the ions through the spectrometer, and detection efficiency for {sup 99}Tc ions after the spectrometer. Based on the positive results of these tests, we have begun to develop a measurement protocol. Technetium is co-precipitated with rhodium, added as a carrier, which provides a sample form appropriate for sputtering and an isotope for AMS normalization. The {sup 99}Tc is determined from the measured {sup 99}Tc/{sup 103}Rh ratio. To reduce interference from the isobar {sup 99}Ru, an oxidation/distillation method was employed to lower ruthenium in the rhodium stock solution. Characteristic projectile L x-rays are used for ion detection to allow further subtraction of {sup 99}Ru. Results for a series of standards demonstrated linearity and reproducibility. A sensitivity of {approx}500 fg {sup 99}Tc was obtained in this preliminary work, and indications are that a sensitivity in the low femtogram range should be achievable.

  20. Tc Reductant Chemistry and Crucible Melting Studies with Simulated Hanford Low-Activity Waste

    SciTech Connect

    Kim, Dong-Sang; Soderquist, Chuck Z.; Icenhower, Jonathan P.; McGrail, B PETER.; Scheele, Randall D.; McNamara, Bruce K.; Bagaasen, Larry M.; Schweiger, Michael J.; Crum, Jarrod V.; Yeager, John D.; Matyas, Josef; Darnell, Lori P.; Schaef, Herbert T.; Owen, Antionette T.; Kozelisky, Anne E.; Snow, Lanee A.; Steele, Marilyn J.

    2005-03-30

    The FY 2003 risk assessment (RA) of bulk vitrification (BV) waste packages used 0.3 wt% of the technetium (Tc) inventory as a leachable salt and found it sufficient to create a significant peak in the groundwater concentration in a 100-meter down-gradient well. Although this peak met regulatory limits, considering uncertainty in the actual Tc salt fraction, peak concentrations could exceed the maximum concentration limit (MCL) under some scenarios so reducing the leachable salt inventory is desirable. The main objective of this study was to reduce the mobile Tc species available within a BV disposal package by reducing the oxidation state of the Tc in the waste feed and/or during melting because Tc in its reduced form of Tc(IV) has a much lower volatility than Tc(VII). Reduced Tc volatility has a secondary benefit of increasing the Tc retention in glass.

  1. Flux-flow behavior in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Raissi, F.; Hassani, F.

    2014-06-01

    We have been exploring flux-flow behavior in high temperature superconductor material by numerically solving Ginzburg-Landau (GL) equation and comparing it to experimental results. Surprisingly, without incorporating phenomenological activation energy and pinning force models and despite the approximate nature of GL equation, the power law IV curves with different exponents are obtained based on the relative magnitudes of normal conductivity ? and ?, the ratio between the London penetration depth (?) and the coherence length (?). Simulations demonstrate that, for typical ? and ? values, vortices of opposite magnetic field polarity are created at two boundaries of the high Tc material and when they reach the center, they pass through and are injected into opposite polarity sides. Injection and what it entails shed light on unexplained high Tc behavior, open ways for practical applications, eliminate the need for phenomenological models, help us to understand and predict high Tc flux-flow properties.

  2. QCD above Tc : Hadrons, partons, and the continuum

    NASA Astrophysics Data System (ADS)

    Biró, T. S.; Jakovác, A.

    2014-11-01

    In this paper we provide a physical picture for the QCD phase transition in terms of qualitative changes in the spectral functions. Our approach takes into account the crossover nature of this transition and counts for the observed strong correlation seen in higher-order susceptibilities. We demonstrate that the hadron resonance gas, which alone describes the thermodynamics at temperatures T <Tc, will appreciably contribute to the total pressure until T ?3 Tc . In this intermediate regime the QCD matter consists of strongly correlated excitations, interpretable as either hadrons or partons. As hadronic spectral peaks gradually vanish, the partonic excitations start to form a stand-alone quasiparticle gas. The conventional picture of a quark gluon plasma emerges only at T ?3 Tc .

  3. Bec Model of HIGH-Tc Superconductivity in Layered Cuprates

    NASA Astrophysics Data System (ADS)

    Lomnitz, M.; Villarreal, C.; de Llano, M.

    2013-11-01

    High-Tc superconductivity in layered cuprates is described in a BCS-BEC formalism with linearly-dispersive s- and d-wave Cooper pairs moving in quasi-2D finite-width layers around the CuO2 planes. This yields a closed formula for Tc involving the layer width, the Debye frequency, the pairing energy and the in-plane penetration depth. The new formula has no free parameters and reasonably reproduces empirical values of superconducting Tcs for 11 different layered superconductors over a wide doping regime including YBCO itself as well as other compounds like LSCO, BSCCO and TBCCO. In agreement with the London formalism, the formula also yields a fair description of the Tc dependence of the lower critical magnetic field in highly underdoped YBCO.

  4. 99mTcO4?-, Auger-Mediated Thyroid Stunning: Dosimetric Requirements and Associated Molecular Events

    PubMed Central

    Cambien, Béatrice; Franken, Philippe R.; Lamit, Audrey; Mauxion, Thibault; Richard-Fiardo, Peggy; Guglielmi, Julien; Crescence, Lydie; Mari, Bernard; Pourcher, Thierry; Darcourt, Jacques; Bardiès, Manuel; Vassaux, Georges

    2014-01-01

    Low-energy Auger and conversion electrons deposit their energy in a very small volume (a few nm3) around the site of emission. From a radiotoxicological point of view the effects of low-energy electrons on normal tissues are largely unknown, understudied, and generally assumed to be negligible. In this context, the discovery that the low-energy electron emitter, 99mTc, can induce stunning on primary thyrocytes in vitro, at low absorbed doses, is intriguing. Extrapolated in vivo, this observation suggests that a radioisotope as commonly used in nuclear medicine as 99mTc may significantly influence thyroid physiology. The aims of this study were to determine whether 99mTc pertechnetate (99mTcO4?) is capable of inducing thyroid stunning in vivo, to evaluate the absorbed dose of 99mTcO4? required to induce this stunning, and to analyze the biological events associated/concomitant with this effect. Our results show that 99mTcO4?–mediated thyroid stunning can be observed in vivo in mouse thyroid. The threshold of the absorbed dose in the thyroid required to obtain a significant stunning effect is in the range of 20 Gy. This effect is associated with a reduced level of functional Na/I symporter (NIS) protein, with no significant cell death. It is reversible within a few days. At the cellular and molecular levels, a decrease in NIS mRNA, the generation of double-strand DNA breaks, and the activation of the p53 pathway are observed. Low-energy electrons emitted by 99mTc can, therefore, induce thyroid stunning in vivo in mice, if it is exposed to an absorbed dose of at least 20 Gy, a level unlikely to be encountered in clinical practice. Nevertheless this report presents an unexpected effect of low-energy electrons on a normal tissue in vivo, and provides a unique experimental setup to understand the fine molecular mechanisms involved in their biological effects. PMID:24663284

  5. High Tc superconducting bolometric and nonbolometric infrared (IR) detectors

    NASA Technical Reports Server (NTRS)

    Lakeou, Samuel

    1994-01-01

    The original workplan for the first year of the project includes the following: establishment of a pilot superconductivity application laboratory at UDC to support the research component of the project; research on the source of electrical noise in High Tc superconducting films in order to optimize the film microstructure and lower the NEP; and lay the foundation of an academic support for exposing UDC students to the theory and application of High Tc superconductivity. Attached to this status report are abstracts and the course description for Introduction to Applications of Superconductivity.

  6. Rugged Low-Resistance Contacts To High-Tc Superconductors

    NASA Technical Reports Server (NTRS)

    Caton, Randall; Selim, Raouf; Byvik, Charles E.; Buoncristiani, A. Martin

    1992-01-01

    Newly developed technique involving use of gold makes possible to fabricate low-resistance contacts with rugged connections to high-Tc superconductors. Gold diffused into specimen of superconducting material by melting gold beads onto surface of specimen, making strong mechanical contacts. Shear strength of gold bead contacts greater than epoxy or silver paste. Practical use in high-current-carrying applications of new high-Tc materials, including superconducting magnets, long-wavelength sensors, electrical ground planes at low temperatures, and efficient transmission of power.

  7. Comparison of (99m)tc-tetrofosmin and (99m)tc-sestamibi uptake in glioma cell lines: the role of p-glycoprotein expression.

    PubMed

    Alexiou, George A; Xourgia, Xanthi; Vartholomatos, Evrysthenis; Tsiouris, Spyridon; Kalef-Ezra, John A; Fotopoulos, Andreas D; Kyritsis, Athanasios P

    2014-01-01

    (99m)Tc-Tetrofosmin ((99m)Tc-TF) and (99m)Tc-Sestamibi ((99m)Tc-MIBI) are SPECT tracers that have been used for brain tumor imaging. Tumor's multidrug resistance phenotype, namely, P-glycoprotein (p-gp), and the multidrug resistance related proteins (MRPs) expression have been suggested to influence both tracers' uptake. In the present study we set out to compare (99m)Tc-TF and (99m)Tc-MIBI uptake in high-grade glioma cell lines and to investigate the influence of gliomas p-gp expression on both tracers' uptake. We used four glioma cell lines (U251MG, A172, U87MG, and T98G). The expression of p-gp protein was evaluated by flow cytometry. Twenty ?Ci (7.4·10(5)?Bq) of (99m)Tc-TF and (99m)Tc-MIBI were used. The radioactivity in the cellular lysate was measured with a dose calibrator. P-gp was significantly expressed only in the U251MG cell line (P < 0.001). In all gliomas cell lines (U251MG, U87MG, A172, and T98G) the (99m)Tc-TF uptake was significantly higher than (99m)Tc-sestamibi. The U251MG cell line, in which significant p-gp expression was documented, exhibited the strongest uptake difference. (99m)Tc-TF uptake was higher than (99m)Tc-MIBI in all studied high-grade glioma cell lines. Thus, (99m)Tc-TF may be superior to (99m)Tc-MIBI for glioma imaging in vivo. PMID:25436147

  8. Comparison of 99mTc-Tetrofosmin and 99mTc-Sestamibi Uptake in Glioma Cell Lines: The Role of P-Glycoprotein Expression

    PubMed Central

    Alexiou, George A.; Xourgia, Xanthi; Vartholomatos, Evrysthenis; Kalef-Ezra, John A.; Fotopoulos, Andreas D.; Kyritsis, Athanasios P.

    2014-01-01

    99mTc-Tetrofosmin (99mTc-TF) and 99mTc-Sestamibi (99mTc-MIBI) are SPECT tracers that have been used for brain tumor imaging. Tumor's multidrug resistance phenotype, namely, P-glycoprotein (p-gp), and the multidrug resistance related proteins (MRPs) expression have been suggested to influence both tracers' uptake. In the present study we set out to compare 99mTc-TF and 99mTc-MIBI uptake in high-grade glioma cell lines and to investigate the influence of gliomas p-gp expression on both tracers' uptake. We used four glioma cell lines (U251MG, A172, U87MG, and T98G). The expression of p-gp protein was evaluated by flow cytometry. Twenty ?Ci (7.4·105?Bq) of 99mTc-TF and 99mTc-MIBI were used. The radioactivity in the cellular lysate was measured with a dose calibrator. P-gp was significantly expressed only in the U251MG cell line (P < 0.001). In all gliomas cell lines (U251MG, U87MG, A172, and T98G) the 99mTc-TF uptake was significantly higher than 99mTc-sestamibi. The U251MG cell line, in which significant p-gp expression was documented, exhibited the strongest uptake difference. 99mTc-TF uptake was higher than 99mTc-MIBI in all studied high-grade glioma cell lines. Thus, 99mTc-TF may be superior to 99mTc-MIBI for glioma imaging in vivo. PMID:25436147

  9. Effect of cyclophosphamide on the binding of 99mTcO-4 and 99mTc-MDP to blood cells and plasma proteins.

    PubMed

    Santos, J S; de-Paula, E F; Correa, T G; de-Freitas, L C; da-Fonseca, L M; Gutfilen, B; Bernardo-Filho, M

    1995-01-01

    Since the introduction of technetium-99m (99mTc) and its rapid acceptance as a tool in nuclear medicine, very little information is available about its biological action as 99mTc-radiopharmaceuticals. We have determined if cyclophosphamide, an alkylating agent, used in oncology as a chemotherapeutic drug, modifies the binding of 99mTcO-4 and 99mTc-MDP (99mTc-methylenediphosphonic acid) to blood cells and to plasma proteins. The radiopharmaceuticals were injected intravenously (iv) into SW-55 mice (male and female, weight 25 g) and samples of plasma and blood cells were separated. Cyclophosphamide (50 micrograms) was injected iv 1 h before the radiopharmaceuticals. Samples of plasma and blood cells were also precipitated with 5% trichloroacetic acid and soluble and insoluble fractions were isolated. The following results were obtained: 1) cyclophosphamide did not alter (0.25 to 8 h) percent radioactivity of 99mTcO-4 in plasma or blood cells but increased the binding of 99mTc-MDP to blood cells; 2) cyclophosphamide did not alter (0.25 to 8 h) the binding of 99mTcO-4 in insoluble fraction of plasma and decreased (1 to 4 h) percent radioactivity of 99mTc-MDP in the insoluble fraction of plasma; 3) cyclophosphamide increased (0.25 to 4 h) percent radioactivity of 99mTcO-4 in the insoluble fraction of blood cells but did not alter the binding of 99mTc-MDP. Cyclophosphamide and/or its metabolites modified the effective half-life of these radiopharmaceuticals (to 99mTcO-4 was increased 2.3 to 3.4 h and to 99mTc-MDP was decreased 3.3 to 2.1 h) and possibly increased the permeability of blood cells to 99mTcO-4. PMID:7581022

  10. Validation of an alternative radiochemical purity method for [99mTc]pentetate ([99mTc]DTPA).

    PubMed

    Borré, María Candela; Tesán, Fiorella C; Leonardi, Natalia M; Zubillaga, Marcela B; Salgueiro, M Jimena

    2013-12-01

    [(99m)Tc]pentetate ([(99m)Tc]DTPA) is the most commonly used radiopharmaceutical renography agent. The aim of this work was to validate an alternative method for assessing [(99m)Tc]DTPA radiochemical purity (RCP), according to the ICH Q2(R1) guidance: "Validation of Analytical Procedures". The proposed method is composed of two chromatographic systems. System A is a miniaturized system of thin layer chromatography (TLC) silica gel impregnated aluminum strips as stationary phase (SP) and distilled water as mobile phase (MP). System B consists of Whatman 1 paper strips as SP and methyl ethyl ketone as MP. Results indicate that the proposed RCP method has been validated, as it is specific, precise, accurate, linear and robust. Therefore, it can be used as an alternative method for RCP quality control purposes and as stability indicator as well. PMID:24140984

  11. Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results

    SciTech Connect

    Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 µg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests conducted to ascertain the effects of changing pH showed that at pH values of 6.5 and 7.5, no significant differences existed in Tc-adsorption performance for three of the carbons, but the fourth carbon performed better at pH 7.5. When the pH was increased to 8.5, a slight decline in performance was observed for all carbons. Tests conducted to ascertain the temperature effect on Tc-99 adsorption indicated that at 21 ºC, 27 ºC, and 32 ºC there were no significant differences in Tc-99 adsorption for three of the carbons. The fourth carbon showed a noticeable decline in Tc-99 adsorption performance with increasing temperature. The presence of volatile organic compounds (VOCs) in the source water did not significantly affect Tc-99 adsorption on either of two carbons tested. Technetium-99 adsorption differed by less than 15% with or without VOCs present in the test water, indicating that Tc-99 adsorption would not be significantly affected if VOCs were removed from the water prior to contact with carbon.

  12. Power Systems Development Facility Gasification Test Run TC09

    SciTech Connect

    Southern Company Services

    2002-09-30

    This report discusses Test Campaign TC09 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode of operation using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier during TC09 in air- and oxygen-blown modes. Test Run TC09 was started on September 3, 2002, and completed on September 26, 2002. Both gasifier and PCD operations were stable during the test run, with a stable baseline pressure drop. The oxygen feed supply system worked well and the transition from air to oxygen was smooth. The gasifier temperature varied between 1,725 and 1,825 F at pressures from 125 to 270 psig. The gasifier operates at lower pressure during oxygen-blown mode due to the supply pressure of the oxygen system. In TC09, 414 hours of solid circulation and over 300 hours of coal feed were attained with almost 80 hours of pure oxygen feed.

  13. Tc-99m PYP scanning following low voltage electrical injury.

    PubMed

    Spencer, R R; Williams, A G; Mettler, F A; Christie, J H; Rosenberg, R D; Weaver, W D

    1983-12-01

    An adolescent boy sustained low voltage electrical injury to his extremities when he inadvertently touched a low tension (440 volts) wire with a metal tube. Early in his hospital course, he was evaluated with Tc-99m pyrophosphate whole body scanning for the extent of his injuries. The scintigraphic findings correlated well with his subsequent clinical course. PMID:6317262

  14. Characterization of high-Tc superconducting tapes using Hall sensors

    Microsoft Academic Search

    Jaakko A. J. Paasi; Markku J. Lahtinen

    1993-01-01

    A new inductive method for the characterization of high-Tc superconducting tapes is proposed and tested. It is based on the measurement of the magnetic field profile produced by induced screening currents in a tape. The measurements are carried out using a movable miniature Hall sensor connected to a special electric circuit, allowing measurements of magnetic fields in the muT range

  15. Superconducting fluctuations and pseudogap in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Rullier-Albenque, F.; Alloul, H.

    2012-03-01

    Large pulsed magnetic fields up to 60 Tesla are used to suppress the contribution of superconducting fluctuations (SCF) to the ab-plane conductivity above Tc in a series of YBa2Cu3O6+x. These experiments allow us to determine the field Hc'(T) and the temperature Tc' above which the SCFs are fully suppressed. A careful investigation near optimal doping shows that Tc' is higher than the pseudogap temperature T*, which is an unambiguous evidence that the pseudogap cannot be assigned to preformed pairs. Accurate determinations of the SCF contribution to the conductivity versus temperature and magnetic field have been achieved. They can be accounted for by thermal fluctuations following the Ginzburg-Landau scheme for nearly optimally doped samples. A phase fluctuation contribution might be invoked for the most underdoped samples in a T range which increases when controlled disorder is introduced by electron irradiation. Quantitative analysis of the fluctuating magnetoconductance allows us to determine the critical field Hc2(0) which is found to be be quite similar to Hc' (0) and to increase with hole doping. Studies of the incidence of disorder on both Tc' and T* allow us to to propose a three dimensional phase diagram including a disorder axis, which allows to explain most observations done in other cuprate families.

  16. The RWTH 2007 TC-STAR Evaluation System for

    Microsoft Academic Search

    Ch. Gollan; S. Hahn; G. Heigold; B. Hoffmeister; Ch. Plahl; D. Rybach; H. Ney

    2007-01-01

    In this work, the RWTH automatic speech recognition systems developed for the third TC-STAR evaluation campaign 2007 are presented. The RWTH systems make systematic use of inter- nal system combination, combining systems with differences in feature extraction, adaptation methods, and training data used. To take advantage of this, novel feature extraction methods were employed; this year saw the introduction of

  17. /sup 99m/Tc-MDP uptake in nonsseous lesions

    SciTech Connect

    Desai, A.; Eymontt, M.; Alavi, A.; Schaffer, B.; Dalinka, M.K.

    1980-04-01

    A strikingly similar, massive, soft-tissue localization of /sup 99m/Tc-MDP is described in three patients who had tumoral calcinosis, milk-alkali syndrome, and chronic renal failure, respectively. Although the basic mechanism for this phenomenon is unknown, some derangement of calcium and phosphate metabolism was present in all three cases.

  18. GM=tc^3 Cosmology and the Moon

    Microsoft Academic Search

    Louise Riofrio

    2010-01-01

    Relativity suggests an expanding cosmology of scale R = ct, where t is age of the Universe. Gravitation would then require that c be further related to t by: GM = tc^3. Where G and M are mass and gravitational constant, this simple expression predicts data from the microwave background, including 4.507034% baryonic matter and a stable density phi= 1

  19. TC an intermediate language for programming chip multiprocessors

    E-print Network

    Jesshope, Chris

    . Ideally, a program written in µTC is a dynamic, concurrent control structure over small sequences of code in the MicroGrid project at the University of Amsterdam, which is designing chip multiprocessors based on the microthreaded model of concurrency [1]. It is also being adapted as a virtual system's architecture (SVM

  20. Development of a high-Tc superconducting levitation synchronous motor

    Microsoft Academic Search

    I. Murakami; Y. Mutsuura; S. Tomaru; Y. Goto; Y. Ando; K. Yamada

    2009-01-01

    In this research, it proposes the Hi-Tc superconducting levitation synchronous motor by using an outer field reversal about the levitation body. This levitation body is a permanent magnet magnetized in the thickness direction. The multipole field is given to outer by making this permanent magnet adsorb larger than the external radius of the magnet more sectorial magnetic material plate. The

  1. Light Dependent Reduction of Pertechnetate (99TcO4?) by Broken Chloroplasts 1

    PubMed Central

    Lembrechts, Johan F.; Desmet, Gilbert M.

    1986-01-01

    Arguments are given for a ferredoxin-mediated reduction of TcO4?, preponderantly into extractable Tc(V) complexes, by illuminated, broken chloroplasts. Photosynthetic O2- and NADP-reduction competitively inhibit Tc incorporation. As for O2, the reaction can be stimulated by the auto-oxidizable electron acceptor methyl viologen. Furthermore TcO4? can function as terminal acceptor in the diaphorase reaction, with NADPH as electron donor. PMID:16664933

  2. A promoter SNP (–1323T>C) in G-substrate gene (GSBS) correlates with hypercholesterolemia

    Microsoft Academic Search

    Shuji Ono; Yoichi Ezura; Mitsuru Emi; Yuko Fujita; Daisuke Takada; Keiko Sato; Tomoaki Ishigami; Satoshi Umemura; Kaneo Takahashi; Kouhei Kamimura; Hideaki Bujo; Yasushi Saito

    2003-01-01

    Factors predisposing to the phenotypic features of higher total cholesterol (TC) have not been clearly defined. Here we report an association between a promoter SNP (-1323T>C) in G-substrate gene ( GSBS) and TC levels in 368 adult individuals from an east-central area of Japan. Age and gender-adjusted levels of LDL-cholesterol, TG, TC, and HDL-cholesterol were analyzed. When we separate the

  3. Tc and Re Behavior in Borosilicate Waste Glass Vapor HydrationTests

    SciTech Connect

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

    2006-11-01

    Technetium (Tc), found in nuclear waste, is of particularconcern with regard to long-term waste storage because of its longhalf-life and high mobility in the environment. One method ofstabilization of such waste is through vitrification to produce a durableborosilicate glass matrix. The fate of Tc under hydrothermal conditionsin the Vapor Hydration Test (VHT) was studied to assess and possiblypredict the long-term rate of release of Tc from borosilicate wasteglass. For comparison, the fate of rhenium (Re), the preferrednon-radioactive surrogate for Tc, was similarly studied. X-ray absorptionspectroscopy (XAS) and scanning electron microscopy (SEM) measurementswere made on each original borosilicate glass and the correspondingsample after the VHT. Tc K-edge XAS indicates that, despite starting withdifferent Tc(IV) and Tc(VII) distributions in each glass, bothcorresponding VHT samples contain 100 percent Tc(IV). The Tc reductionwithin the VHT samples may be driven by simultaneous oxygen depletionfrom corrosion of the surrounding stainless steel vessel. From SEManalyses, both of the Tc-containing VHT samples show complete alterationof the original glass, significant Tc enrichment near the sample surface,and nearly complete depletion of Tc toward the sample center. XASindicates Tc(IV)O6 octahedra, possibly within gel-like amorphoussilicates in both VHT samples, where Tc-Tc correlations are observed inthe higher Tc-content VHT sample. Re LII-edge XAS and SEM indicate quitedifferent behavior for Re under VHT conditions. Re oxidation stateappears to be invariant with respect to the VHT treatment, whereperrhenate (Re(VII)) species are dominant in all Re-containing samplesinvestigated; Re2O7 concentrations are low NEAR the sample surface andincrease to approach the concentration of the un-reacted glass toward thesample center.

  4. Technetium Tc 99m plasmin in the diagnosis of inflammatory disease

    Microsoft Academic Search

    Azu Owunwanne; David A. Weber; Irving L. Spar; George A. Wilson; Robert E. O'Mara

    1987-01-01

    The localization characteristics of technetium Tc 99m plasmin were studied in experimental animals to investigate the use of99mTc-plasmin for imaging inflammatory processes. At various times after abscess induction using turpentine in rats, the in vivo distribution properties of99mTc-plasmin, gallium citrate Ga 67,125I-fibrinogen, and99mTc-human serum albumin (HSA) were studied by gamma-camera imaging. The in vivo binding of each radiopharmaceutical was also

  5. Text classification Naive Bayes NB theory Evaluation of TC naive bayes document claasification

    E-print Network

    Lu, Jianguo

    Text classification Naive Bayes NB theory Evaluation of TC naive bayes document claasification Most, 2014 naive bayes document claasification 1 / 52 #12;Text classification Naive Bayes NB theory Evaluation of TC Overview 1 Text classification 2 Naive Bayes 3 NB theory 4 Evaluation of TC naive bayes

  6. Folding and unfolding thermodynamics of the TC10b Trp-cage miniprotein.

    PubMed

    English, Charles A; García, Angel E

    2014-02-21

    We examine the folding-unfolding of a variant of the Trp-cage, known as TC10b, and compare structural stability, dynamics, and thermodynamics with that of the TC5b variant, using replica exchange molecular dynamics (REMD). The TC10b variant was designed to have larger helical stability by the substitution of amino acids with greater alpha helical propensities in the N-terminal region. Experiments have shown TC10b to possess larger overall stability than TC5b. Simulations starting from unbiased, unfolded initial conditions are run for 1 ?s per replica. The calculations show a higher melting temperature for TC10b than TC5b, and suggest a more ordered folded structure through the elimination of a substate found in the folded ensemble of TC5b. We model the difference in Gibbs free energy, ?G(P,T), of folding using the bootstrap statistical method, which is used to calculate uncertainties associated with the thermodynamic parameters for both variants of the Trp-cage. We find that while the shape of the area for which the protein is stability folded is elliptical for TC5b, there is a degree of uncertainty associated with that of TC10b, with one model suggesting elliptical and another suggesting hyperbolic. This model suggests that at high pressures, TC5b can experience pressure denaturation, but TC10b may not. PMID:24448113

  7. Dipole Magnet from High Tc Superconductor

    NASA Astrophysics Data System (ADS)

    Nielsen, Gunver; Zangenberg, Nikolaj; Hazelton, Drew; Hauge, Nils; Nielsen, Bjarne Roger; Møller, Søren Pape; Baurichter, Arnd

    The applicability of second-generation high-temperature superconductors (HTS) made from YBCO coated conductors in accelerator magnet technology was demonstrated by a consortium under the lead of Danfysik. A 3T demonstrator dipole magnet was designed, built and tested by the consortium. In total 2.5 km HTS tape was manufactured and tested by SuperPower. The tape was delivered in spool lengths 0varying from 93 m to 172 m and had a minimum Ic of 115 A or more. The tape was insulated with a 0.025 mm thin epoxy film before winding in total 14 saddle coils and 4 racetrack coils and subsequent impregnation with epoxy. All coils were azimuthally arranged in an ellipse configuration in order to achieve a cosine-theta-like current distribution around a circular good field with a diameter of 52 mm and a magnetic field length of 250 mm. The cold-mass consisting of the coil arrangement clamped in between a steel substrate and an aluminum collar and a surrounding laminated iron yoke, was mounted in a cryostat. The cold-mass is contact-cooled by two GM cryocoolers

  8. A possible explanation of pressure dependence of critical temperature Tc of alkali doped C60 superconductors

    NASA Astrophysics Data System (ADS)

    Pandey, Rajiv Kumar

    2015-10-01

    The pressure dependent changes in transition temperature (Tc) of alkali doped C60 superconductor has been studied theoretically considering the combination of phonon mediated mechanism and high energy electronic interaction mechanism. The latter mechanism involves bond polarization in interaction with conduction electrons. The expression for Tc, isotope effect coefficient (?) and (dTc/dP)P has been obtained to explain the observed experimental results of alkali doped C60. A good agreement has been found in experimental (Tc) and (dTc/dP)P = 0 values and calculated values.

  9. A Study of Cirrus Ice Particle Size Distribution Using TC4 Observations

    NASA Technical Reports Server (NTRS)

    Tian, Lin; Heymsfield, Gerald M.; Li, Lihua; Heymsfield, Andrew J.; Bansemer, Aaron; Twohy, Cynthia H.; Srivastava, Ramesh C.

    2010-01-01

    An analysis of two days of in situ observations of ice particle size spectra, in convectively generated cirrus, obtained during NASA s Tropical Composition, Cloud, and Climate Coupling (TC4) mission is presented. The observed spectra are examined for their fit to the exponential, gamma, and lognormal function distributions. Characteristic particle size and concentration density scales are determined using two (for the exponential) or three (for the gamma and lognormal functions) moments of the spectra. It is shown that transformed exponential, gamma, and lognormal distributions should collapse onto standard curves. An examination of the transformed spectra, and of deviations of the transformed spectra from the standard curves, shows that the lognormal function provides a better fit to the observed spectra.

  10. Tc-99m radioaerosol clearance as an index of pulmonary epithelial permeability

    SciTech Connect

    Waldman, D.L.

    1988-01-01

    This investigation examines radiopharmaceutical clearance as an index of alveolar-capillary membrane permeability and as an indicator of disease. Specific objectives include: evaluation of radiopharmaceutical chemical purity following aerosolization, investigation of a chemically related family of compounds to develop new radiopharmaceuticals with improved chemical properties, determination of reproducibility of the radiopharmaceutical clearance technique and the evaluation of the sensitivity of aerosolized solute clearance as an indicator of lung injury. The integrity of the radiopharmaceutical was examined prior to and following aerosol generation. The in vivo pharmacokinetics of a family of aerosolized solutes was evaluated in the beagle dog. The reproducibility of the biological response to radiopharmaceutical deposition was evaluated using dynamic functional imaging in humans and in the beagle. The sensitivity of the technique was evaluated using Tc-99m DTPA and an animal model for lung injury.

  11. High-energy anomalies in covalent high-Tc cuprates with large Hubbard Ud on copper

    NASA Astrophysics Data System (ADS)

    Bariši?, O. S.; Bariši?, S.

    2015-03-01

    A large Ud theory is constructed for the metallic state of high-Tc cuprates. The Emery three-band model, extended with Ox-Oy hopping tpp, and with Ud ? ?, is mapped on slave fermions. The Dyson time-dependent diagrammatic theory in terms of the Cu-O hopping tpd, starting from the nondegenerate unperturbed ground state, is translationally and asymptotically locally gauge invariant. The small parameter of the theory is the average hole occupation of Cu sites nd. The lowest order of the theory generates the single particle propagators of the hybridized pdp- and dpd-fermions with the exact covalent three band structure. The leading many-body effect is band narrowing, accompanied by Landau-like damping of the single particle propagation, due to incoherent local charge Cu-O fluctuations. The corresponding continuum is found below and above the Fermi level.

  12. Electrical and thermal transport properties in high Tc superconductors: effects of a magnetic field

    NASA Astrophysics Data System (ADS)

    Ausloos, M.

    2001-05-01

    Experimental studies of the electric and heat currents in the normal, superconducting and mixed states of high Tc superconductors (HTcS) lead to characterization, complementary to data obtained from equilibrium property based techniques. A magnetic field superimposed on the superconducting sample generates magneto-transport phenomena, from which an excess electrical resistivity, an excess thermoelectric power, the Hall or the Nernst effect. Different behavioural effects allow one to distinguish various dissipation mechanisms, like quasi-particle scattering, vortex motion dissipation and superconductivity fluctuations, in particular when the Corbino geometry is used. Moreover bulk measurements of the thermal conductivity and the electrothermal conductivity in a magnetic field give us sure indications of the order parameter symmetry. The location of the mixed state phase transition lines in the technological phase diagram of HTcS are briefly pointed out through precise measurements performed over broad temperature and magnetic field ranges. The results are mainly reviewed with the aim of defining further investigation lines.

  13. Decay study of {sup 114}Tc with a Penning trap

    SciTech Connect

    Rissanen, J.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Moore, I. D.; Karvonen, P.; Penttilae, H.; Rahaman, S.; Reponen, M.; Saastamoinen, A.; Weber, C.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FI-40014 Jyvaeskylae (Finland); Kurpeta, J.; Plochocki, A. [Faculty of Physics, University of Warsaw, ul. Hoza 69, 00-681 Warsaw (Poland); Prochniak, L. [Institute of Physics, Maria Curie-Sklodowska University, pl. Maria Curie-Sklodowskiej 1, 20-031 Lublin (Poland); Szerypo, J. [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Am Coulombwall 1, D-85748 Garching (Germany); Urban, W. [Faculty of Physics, University of Warsaw, ul. Hoza 69, 00-681 Warsaw (Poland); Institut Laue-Langevin, 6 rue J. Horowitz, F-38042 Grenoble (France)

    2011-01-15

    The level structure of {sup 114}Ru has been investigated via the {beta} decay of very neutron-rich {sup 114}Tc by means of Penning-trap-assisted {gamma} spectroscopy. The deduced {beta}-decay scheme suggests the existence of two {beta}-decaying states in {sup 114}Tc with I{sup {pi}}=1{sup +} and I{>=} 4, with half-lives of t{sub 1/2}(1{sup +})=90(20) ms and t{sub 1/2}(I{>=}4)=100(20) ms, respectively. The Q{sub {beta}} value, which covers a possible mixture of two states, has been determined to be Q{sub {beta}}=11 785(12) keV. The level energies in {sup 114}Ru are compared with theory by using a microscopic Bohr Hamiltonian approach with the Sly4 version of the Skyrme interaction.

  14. Multiband superconductivity in high Tc cuprates and diborides

    NASA Astrophysics Data System (ADS)

    Bianconi, Antonio

    2006-01-01

    The normal state of magnesium diboride, the simplest metallic system showing the macroscopic quantum coherence at high temperature (high Tc superconductivity HTcS), shows some features that are common with the cuprates, shedding light on the pairing mechanism for Tc amplification in HTcS: (1) the system is made of two or more electronic components associated with multiple Fermi surface portions; (2) the chemical potential is tuned where the Fermi level in one Fermi surface portion is near the crossing of an electronic topological transition (ETT) where the Fermi surface changes its topology; and (3) an optical phonon branch shows softening due to an extended Khon anomaly (EKA) over a large wave vector range.

  15. Enhanced dc spin pumping into a fluctuating ferromagnet near TC

    NASA Astrophysics Data System (ADS)

    Ohnuma, Yuichi; Adachi, Hiroto; Saitoh, Eiji; Maekawa, Sadamichi

    2014-05-01

    A linear-response formulation of the dc spin pumping, i.e., a spin injection from a precessing ferromagnet into an adjacent spin sink, is developed in view of describing many-body effects caused by spin fluctuations in the spin sink. It is shown that when an itinerant ferromagnet near TC is used as the spin sink, the spin pumping is largely increased owing to the fluctuation enhancement of the spin conductance across the precessing ferromagnet/spin sink interface. As an example, the enhanced spin pumping from yttrium iron garnet into nickel palladium alloy (TC?20 K) is analyzed by means of a self-consistent renormalization scheme, and it is predicted that the enhancement can be as large as tenfold.

  16. First Evaluation of a 99mTc Tricarbonyl Complex, 99mTc(CO)3(LAN), As a New Renal Radiopharmaceutical in Humans

    PubMed Central

    Lipowska, Malgorzata; He, Haiyang; Malveaux, Eugene; Xu, Xiaolong; Marzilli, Luigi G.; Taylor, Andrew

    2014-01-01

    99mTc-mercaptoacetyltriglycine (99mTc-MAG3), 99mTc-dd- and ll-ethylene-di-cysteine (99mTc-EC) and 99mTc-mercaptoacetamide-ethylene-cysteine (99mTc-MAEC) contain N3S or N2S2 ligands designed to accommodate the four ligating sites of the {99mTcO}3+ core; they are all excellent renal imaging agents but have renal clearances less than that of 131I-orthoiodohippurate (131I-OIH). To explore the potential of the newly accessible but less polar {99mTc(CO)3}+ core having three ligating sites, we decided to build on the success of 99mTc-EC with its N2S2 ligand and two dangling carboxylates and have chosen an N2S ligand that also has two dangling carboxyls, lanthionine (LANH2), to form 99mTc(CO)3(LAN), a new renal radiopharmaceutical. Methods Biodistribution studies were performed on Sprague-Dawley rats by using 99mTc(CO)3(LAN) isomers, meso-LAN and dd,ll-LAN (an enantiomeric mixture), coinjected with 131I-OIH. Human studies were also performed by coinjecting each 99mTc product (~74 MBq [~2 mCi]) and 131I-OIH (~ 7.4 MBq [~ 0.2 mCi]) into 3 normal volunteers with dual-isotope imaging performed by using a camera system fitted with a high-energy collimator. Blood samples were obtained from 3 to 90 min after injection, and urine samples were obtained at 30, 90 and 180 min. Results Biodistribution studies in rats revealed a rapid blood clearance as well as rapid renal extraction for both preparations, with the dose in urine at 60 min averaging 88% that of 131I-OIH. In humans, both agents provided excellent renal images, with the plasma clearance averaging 228 mL/min for 99mTc(CO)3(meso-LAN) and 176 mL/min for 99mTc(CO)3(dd,ll-LAN), respectively. At 3 hours, both 99mTc(CO)3(meso-LAN) and 99mTc(CO)3(dd,ll-LAN), showed good renal excretion, averaging 85% and 77% that of 131I-OIH, respectively. Plasma protein binding was minimal (10% and 2%), and red cell uptake was similar (24% and 21%) for 99mTc(CO)3(meso-LAN) and 99mTc(CO)3(dd,ll-LAN), respectively. Conclusion Although the plasma clearance and the rate of renal excretion of the 99mTc(CO)3(LAN) complexes are still less than those of 131I-OIH, the results of this first application of a 99mTc tricarbonyl complex as a renal radiopharmaceutical in humans demonstrate that 99mTc(CO)3(LAN) complexes are excellent renal imaging agents and support continued renal radiopharmaceutical development based on the 99mTc tricarbonyl core. PMID:16741314

  17. Bosonic high-Tc superconductivity in two dimensions

    Microsoft Academic Search

    W. Zhu; H. Kang; Y. C. Lee; Jin-Chang Chen

    1994-01-01

    The mixed boson-fermion model of superconductivity of Friedburg and Lee is adapted to two dimensions. Owing to the finite correlation length l(T), Bose-Einstein (BE) condensation can prevail only for a finite, but still macroscopic system. It is shown that for T<Tc~40 K, BE condensation of charged bosons that are converted from fermion (electron or hole) pairs leads not only to

  18. An Overview of ER2 Platform Science during TC4

    Microsoft Academic Search

    S. Platnick; P. A. Newman

    2007-01-01

    The NASA high-altitude ER-2 aircraft flew 11 science flight out of San Jose, Costa Rica during July and August 2007 as part of the NASA-sponsored Tropical Composition, Clouds and Climate Coupling Experiment (TC4). The ER-2 flew a remote sensing payload consisting of passive optical and microwave imagers (MAS\\/MASTER, CoSSIR, AMPR), a high spectral resolution IR imager (S-HIS), active sensors (CPL

  19. ''Hot'' spleen on Tc-99m sulfur colloid images

    SciTech Connect

    Lin, D.S.

    1983-06-01

    In routine Tc-99m sulfur colloid (SC) liver-spleen imaging, relatively increased splenic uptake when compared with liver uptake is frequently seen. Commonly this is due to decreased hepatic uptake secondary to liver disease, but often it is because of increased uptake in the hyperfunctioning spleen. Reported is a case of lymphoma of the tonsil, with a ''hot'' spleen which was free of tumor. Possible etiology of the ''hot'' spleen is discussed and the known causes listed according to their prevalence.

  20. Design of a 1 MVA high Tc superconducting transformer

    Microsoft Academic Search

    Woo-Seok Kim; Song-Yop Hahn; Kyeong-Dal Choi; Hyeong-Gil Joo; Kye-Won Hong

    2003-01-01

    A 1 MVA transformer using BSCCO-2223 high Tc superconducting (HTS) tapes was designed. The rated voltages of each sides of the transformer for primary and secondary are 22.9 kV and 6.6 kV respectively. Double pancake HTS windings, which have advantages of insulations and distribution of high voltage, were adopted. Four HTS tapes were wound in parallel for the windings of

  1. Test of a high Tc superconducting power transformer

    Microsoft Academic Search

    Kyeong Dal Choi; Hee Joon Lee; Gueesoo Cha; Kyung Woo Ryu; Woo Seok Kim; Song Yop Hahn

    2000-01-01

    A single-phase power transformer with windings made of Tc superconducting tapes was fabricated and tested. The tapes are made of Bi-2223 imbedded in a silver alloy matrix. The primary and secondary windings are made of double pancake coil. The rated voltages of the windings are 220\\/110 V. Four pancake type coil windings are stacked on the core. The inner two

  2. Rhenium Uptake as Analogue 96Tc by Steel Corrosion Products

    SciTech Connect

    K.M. Krupka, C.F. Brown, H. Todd Schaef, S. M. Heald, M. M. Valenta, B. W. Arey

    2006-04-30

    Static batch experiments were used to examine the sorption of dissolved perrhenate [Re(VII)], as a surrogate for pertechnetate [Tc(VII)], on corrosion products of A-516 carbon steel coupons contacted with synthetic groundwater or dilute water. After 109 days of contact time, the concentration of dissolved Re(VII) in the synthetic groundwater matrix decreased by approximately 26%; the dilute water matrix experienced a 99% decrease in dissolved Re(VII) over the same time period. Bulk x-ray diffraction (XRD) results for the corroded steel coupons showed that the corrosion products consisted primarily of maghemite, lepidocrocite, and goethite. Analyses of the coupons by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) indicated that Re was present with the morphologically complex assemblages of Fe oxide/hydroxide corrosion products for samples spiked with the highest dissolved Re(VII) concentration (1.0 mmol/L) used for these experiments. Analyses of corroded steel coupons contacted with solutions containing 1.0 mmol/L Re(VII) by synchrotron-based methods confirmed the presence of Re sorbed with the corrosion product on the steel coupons. Analyses showed that the Re sorbed on these corroded coupons was in the +7 oxidation state, suggesting that the Re(VII) uptake mechanism did not involve reduction of Re to a lower oxidation state, such as +4. The results of our studies using Re(VII) as an analogue for {sup 99}Tc(VII) suggest that {sup 99}Tc(VII) would also be sorbed with steel corrosion products and that the inventory of {sup 99}Tc(VII) released from breached waste packages would be lower than what is now conservatively estimated.

  3. Power Systems Development Facility Gasification Test Run TC08

    SciTech Connect

    Southern Company Services

    2002-06-30

    This report discusses Test Campaign TC08 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier in air- and oxygen-blown modes during TC08. Test Run TC08 was started on June 9, 2002 and completed on June 29. Both gasifier and PCD operations were stable during the test run with a stable baseline pressure drop. The oxygen feed supply system worked well and the transition from air to oxygen blown was smooth. The gasifier temperature was varied between 1,710 and 1,770 F at pressures from 125 to 240 psig. The gasifier operates at lower pressure during oxygen-blown mode due to the supply pressure of the oxygen system. In TC08, 476 hours of solid circulation and 364 hours of coal feed were attained with 153 hours of pure oxygen feed. The gasifier and PCD operations were stable in both enriched air and 100 percent oxygen blown modes. The oxygen concentration was slowly increased during the first transition to full oxygen-blown operations. Subsequent transitions from air to oxygen blown could be completed in less than 15 minutes. Oxygen-blown operations produced the highest synthesis gas heating value to date, with a projected synthesis gas heating value averaging 175 Btu/scf. Carbon conversions averaged 93 percent, slightly lower than carbon conversions achieved during air-blown gasification.

  4. Extraosseous localization of 99m Tc-MDP in ganglioneuroblastoma

    Microsoft Academic Search

    Wei-Jen Shih; Frank H. DeLand; Peggy A. Domstad; Edward H. Johnston

    1982-01-01

    A 21\\/2-year-old boy with a posterior mediastinal ganglioneuroblastoma was evaluated by bone scintigraphy using 99mTc-MDP and showed a marked increased uptake in the tumor mass. Although a routine chest X-ray and body CT scan failed to demonstrate calcification, X-ray examination of the removed tumor specimen revealed small scattered calcification. The proposed mechanisms of the radiopharmaceutical localization in benign and malignant

  5. Oxygen ‘disorder’ and the structures of high- Tc superconductors

    NASA Astrophysics Data System (ADS)

    Hewat, A. W.; Hewat, E. A.; Bordet, P.; Capponi, J. J.; Chaillout, C.; Chenavas, J.; Hodeau, J. L.; Marezio, M.; Strobel, P.; François, M.; Yvon, K.; Fischer, P.; Tholence, J. L.

    1989-01-01

    All of the high- Tc pervoskite superconductors appear to show disorder of certain oxygen atoms. In (La,Sr) 2CuO 4 and perhaps also in YBa 2Cu 3O 7 this is associated with a structural transition. The Bi and Tl superconductors, for which we now have structural data on four different phases, also show oxygen ‘disorder’. This may be related to valence fluctuations.

  6. Collective band structures in the 99Tc nucleus

    NASA Astrophysics Data System (ADS)

    Li, H. J.; Xiao, Z. G.; Zhu, S. J.; Patial, M.; Qi, C.; Cederwall, B.; Zhang, Z.; Wang, R. S.; Yi, H.; Yan, W. H.; Cheng, W. J.; Huang, Y.; Lyu, L. M.; Zhang, Y.; Wu, X. G.; He, C. Y.; Zheng, Y.; Li, G. S.; Li, C. B.; Li, H. W.; Liu, J. J.; Luo, P. W.; Hu, S. P.; Wang, J. L.; Wu, Y. H.

    2015-05-01

    Excited states in 99Tc with energies up to 6 MeV have been populated using the 96Zr(7Li,4 n )99Tc reaction with a laboratory beam energy of 35 MeV. Coincident ? rays from excited nuclei produced in the reactions were detected using an array of coaxial, planar, and clover-type high-purity germanium detectors. A total of 60 new ? -ray transitions and 21 new levels are identified and placed into a new level scheme. Two collective bands assigned to be built on the ? g9 /2 [422 ]5 /2 + and ? p1 /2 [301 ]1 /2 - Nilsson configurations have been extended with spins up to 35/2 and 33 /2 ? , respectively. Backbending and signature inversion have been observed in the yrast band. The large signature splitting of the positive-parity band in 99Tc may be caused by a triaxial deformation, which agrees well with the electromagnetic properties, theoretical calculations based on total Routhian surface, and triaxial particle-rotor model calculations.

  7. Irradiation of the TC255P CCD by Fast Neutrons

    E-print Network

    Hashemi, K S

    1998-01-01

    The TC255P is a CCD manufactured by Texas Instruments. We propose to use it in the ATLAS end-cap muon alignment system. To find out if it could operate for ten years in the ATLAS radiation environment, we exposed four TC255Ps to fast neutrons. The doses delivered to the CCDs varied from one to three times the highest expected ten-year ATLAS dose in the end-cap. We observed that the dark current in the CCDs increased dramatically. But we observed no other forms of damage. We believe we understand the means by which neutron bombardment causes an increase in the dark current, and we have an empirical model that describes the progress of the damage with accumulated dose. This model predicts that, once we have made a number of simple changes to the image retrieval procedure, the TC255P will be able to operate for one hundred and thirty years in the ATLAS radiation environment.

  8. Validation of a kinetic model for receptor-mediated uptake of Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA)

    SciTech Connect

    Vera, D.R.; Krohn, K.A.; Woodle, E.S.; Scheibe, P.O.; Stadalnik, R.C.

    1984-01-01

    Tc-NGA is a receptor-binding radiopharmaceutical which localizes specifically to the liver. The rate of uptake depends upon: 1) Tc-NGA-receptor affinity, k/sub b/, 2) molar dose, L/sub e/(O), and 3) hepatic blood flow, Q. The authors have proposed a kinetic model which describes hepatic uptake in terms of measurable physiochemical quantities: Q, k/sub b/, R, V/sub e/, V/sub h/ (systemic and liver blood volumes), and V/sub r/ (liver plasma volume). Computer simulations were compared to kinetic data (ROIs: precordium and liver, 420 data pts) resulting from injection into pigs (n=12) of Tc-NGAs of differing k/sub b/(0.6,1.2,1.8 x 10/sup 5/ M/sup -1/sec/sup -1/). Each pig was studied twice using different molar doses (0.5 - 10. x 10/sup -8/mole). Measurements of V/sub e/ (Tc-RBCs) and Q (indocyanine green extraction) were obtained during each study. Weights of excised livers were used to calculate V/sub h/ and r. With exception of the low-dose, low-affinity studies, all data was fit to within a reduced chi-square of 3 by adjustment of 1/sub e/, 1/sub h/, c, ..cap alpha../sub m/ and the sigmas. The authors conclude that this model is a valid description of a receptor-binding process, however competition by endogenous ligand may prevent its use at low molar doses of low-k/sub b/ NGA.

  9. [A new lymph node imaging agent--99mTc-polyphase liposome oleatis (99mTc-plo)].

    PubMed

    Yu, B F

    1988-07-01

    A new lymph node radio-imaging agent, technetium-99m polyphase liposome oleatis (99mTc-plo), has recently been developed. Polyphase liposome oleatis was labelled with radionuclide by stannous chloride method. The labelled rate was 90% or more as technically identified by thin layer chromatography, external gamma-camera imaging and radioautography. In animal experiment, 0.2-0.3 ml (0.2 mci) of the 99mTc-plo was injected subcutaneously into the toes web of rats. After half an hour, the regional lymph nodes of popliteal fossa were visualized very clearly. The imaging figures may keep their distinct shadow up to 24 hours. The tested rabbits were sacrificed 10 hours after 99mTc-plo injection for detecting various kinds of tissue and organ with a scintillation counter. The regional lymph nodes revealed the highest uptake rate of the new agent, 12,116; 1,303; 1,615 times higher than that of the adjacent muscles, liver and spleen, respectively. In clinical experiment, 0.2-0.3 ml (0.5-0.8 mci) of the 99mTc-plo was injected subcutaneously into the toes web of patients. Half an hour later, the lymph nodes of inguinal, external iliac and common iliac regions appeared in sequence. If the new agent is injected perianally, the internal iliac lymph nodes will be seen. No side effect was observed in both types of experiment. This new agent has been tried in rats, rabbits and dogs with similar positive results. The new lymph node imaging technique is simple, safe, reliable and reproducible. This agent, being directed toward the lymph nodes and possessing affinity to cancer cells, is expected to be supplementary method to CT and B-ultrasonography for detecting lymphoid malignancy and lymph node metastasis. PMID:3248482

  10. The endonuclease NL1Tc encoded by the LINE L1Tc from Trypanosoma cruzi protects parasites from daunorubicin DNA damage.

    PubMed

    Olivares, M; López, M C; García-Pérez, J L; Briones, P; Pulgar, M; Thomas, M C

    2003-04-15

    In the present paper we show that the overexpression of the NL1Tc protein, encoded by the L1Tc non-LTR retrotransposon from Trypanosoma cruzi, led to a reduction of about 60% of DNA damage caused by daunorubicin treatment. This repair effect is not observed in transfected parasites overexpressing the NL1Tc mutated in the aspartic acid located in the active site of the enzyme. In addition, NL1Tc overexpression protects the parasite from the negative effect that daunorubicin has on parasite's growth rate. Thus, parasites overexpressing NL1Tc show, after treatment with 4 microM of daunorubicin, growth rate two to three times higher than the growth rate observed in treated control parasites transformed with the empty vector or overexpressing the mutated NL1Tc. Likewise, parasites overexpressing the NL1Tc protein and irradiated with a single dose of gamma-radiation (6 or 9 Gy) show higher growth rates than the parasites overexpressing the mutated NL1Tc or the control transfected parasites. PMID:12697326

  11. Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up.

    PubMed

    Lisboa, Cristiane Varella; Monteiro, Rafael Veríssimo; Martins, Andreia Fonseca; Xavier, Samantha Cristina das Chagas; Lima, Valdirene Dos Santos; Jansen, Ana Maria

    2015-05-01

    Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI. PMID:25946156

  12. Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up

    PubMed Central

    Lisboa, Cristiane Varella; Monteiro, Rafael Veríssimo; Martins, Andreia Fonseca; Xavier, Samantha Cristina das Chagas; Lima, Valdirene dos Santos; Jansen, Ana Maria

    2015-01-01

    Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI. PMID:25946156

  13. Measurements of the absolute value of the penetration depth in high-Tc superconductors using a low-Tc superconductive coating

    E-print Network

    Prozorov, Ruslan

    Measurements of the absolute value of the penetration depth in high-Tc superconductors using a low September 2000 A method is presented to measure the absolute value of the London penetration depth, (T 0 with film of low-Tc material of known thickness and penetration depth. The method is applied to obtain (YBa2

  14. The determination of relative renal function in a pediatric population using Tc-99m DTPA and Tc-99m DMSA

    SciTech Connect

    Rosen, P.R.; Kuruc, A.; Treves, S.T.

    1985-05-01

    Three methods for evaluating relative renal function in a pediatric population were compared. The clinical and nuclear medicine data of 73 patients were reviewed. Pertinent data included patient age, serum creatinine and the referral diagnosis (reflux, hypertension, obstructive uropathy). Time activity curves for renal regions of interest (ROI) were obtained by renography with Tc-99m DTPA, and deconvolved by an externally detected blood pool curve Furosemide was then administered to evaluate the renal collecting system (if indicated). This was followed by DMSA administration. Relative function was determined in 3 ways: 1) Accumulated renal DTPA activity 60-120 sec. following injection. 2) Amplitude of the tubular phase of the deconvolved renal curve and, 3) Accumulated Tc-99m DMSA activity in renal ROI 4 or 24 hrs. post-injection. Regression analysis revealed: 1) The basic relationship of relative functional data obtained by all three methods was not affected by creatinine, age or other factors. 2) The relationship between the three methods is linear and highly correlated. 3) The DMSA values may be predicted from either method of analyzing the DTPA study using appropriate predictor equations. The authors conclude that Tc-99m DMSA, due to its higher cost and more radiation exposure should not be used for the routine evaluation of relative renal function.

  15. Tc and Re Behavior in Borosilicate Waste Glass Vapor Hydration Tests

    SciTech Connect

    McKeown, David A.; Buechele, Andrew C.; Pegg, Ian L. [Vitreous State Laboratory, Catholic University of America, 620 Michigan Ave., N.E., Washington, DC, 20064 (United States); Lukens, Wayne W.; Shuh, David K. [Actinide Chemistry Group, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 (United States)

    2007-07-01

    Technetium (Tc), found in some nuclear wastes, is of particular concern with regard to long-term storage, because of its long-lived radioactivity and high mobility in the environment. Tc and rhenium (Re), commonly used as a non-radioactive surrogate for Tc, were studied to assess their behavior in borosilicate glass under hydrothermal conditions in the Vapor Hydration Test (VHT). X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on the original Tc- and Re-containing glasses and their corresponding VHT samples, and show different behavior for Tc and Re under VHT conditions. XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, the VHT samples have 100% Tc(IV)O{sub 6} environments. SEM shows complete alteration of the original glass, Tc enrichment near the sample surface, and Tc depletion in the center. Perrhenate (Re(VII)O{sub 4}{sup -}) is dominant in both Re-containing samples before and after the VHT, where Re is depleted near the VHT sample surface and more concentrated toward the center. (authors)

  16. Tc And Re Behavior in Borosilicate Waste Glass Vapor Hydration Tests

    SciTech Connect

    McKeown, D.A.; Buechele, A.C.; Lukens, W.W.; Shuh, D.K.; Pegg, I.L.; /Catholic U. /LBL, Berkeley

    2007-07-10

    Technetium (Tc), found in some nuclear wastes, is of particular concern with regard to long-term storage, because of its long-lived radioactivity and high mobility in the environment. Tc and rhenium (Re), commonly used as a non-radioactive surrogate for Tc, were studied to assess their behavior in borosilicate glass under hydrothermal conditions in the Vapor Hydration Test (VHT). X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on the original Tc- and Re-containing glasses and their corresponding VHT samples, and show different behavior for Tc and Re under VHT conditions. XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, the VHT samples have 100% Tc(IV)O6 environments. SEM shows complete alteration of the original glass, Tc enrichment near the sample surface, and Tc depletion in the center. Perrhenate (Re(VII)O4) is dominant in both Re-containing samples before and after the VHT, where Re is depleted near the VHT sample surface and more concentrated toward the center.

  17. Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.

    PubMed

    Triantis, Charalampos; Tsotakos, Theodoros; Tsoukalas, Charalampos; Sagnou, Marina; Raptopoulou, Catherine; Terzis, Aris; Psycharis, Vassilis; Pelecanou, Maria; Pirmettis, Ioannis; Papadopoulos, Minas

    2013-11-18

    The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to ?-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, ?-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as ?-diketone provides a solid example of the pharmacological potential of this system. PMID:24199833

  18. Nucleic-acid-binding properties of the C2-L1Tc nucleic acid chaperone encoded by L1Tc retrotransposon.

    PubMed

    Heras, Sara R; Thomas, M Carmen; Macias, Francisco; Patarroyo, Manuel E; Alonso, Carlos; López, Manuel C

    2009-12-15

    It has been reported previously that the C2-L1Tc protein located in the Trypanosoma cruzi LINE (long interspersed nuclear element) L1Tc 3' terminal end has NAC (nucleic acid chaperone) activity, an essential activity for retrotransposition of LINE-1. The C2-L1Tc protein contains two cysteine motifs of a C2H2 type, similar to those present in TFIIIA (transcription factor IIIA). The cysteine motifs are flanked by positively charged amino acid regions. The results of the present study show that the C2-L1Tc recombinant protein has at least a 16-fold higher affinity for single-stranded than for double-stranded nucleic acids, and that it exhibits a clear preference for RNA binding over DNA. The C2-L1Tc binding profile (to RNA and DNA) corresponds to a non-co-operative-binding model. The zinc fingers present in C2-L1Tc have a different binding affinity to nucleic acid molecules and also different NAC activity. The RRR and RRRKEK [NLS (nuclear localization sequence)] sequences, as well as the C2H2 zinc finger located immediately downstream of these basic stretches are the main motifs responsible for the strong affinity of C2-L1Tc to RNA. These domains also contribute to bind single- and double-stranded DNA and have a duplex-stabilizing effect. However, the peptide containing the zinc finger situated towards the C-terminal end of C2-L1Tc protein has a slight destabilization effect on a mismatched DNA duplex and shows a strong preference for single-stranded nucleic acids, such as C2-L1Tc. These results provide further insight into the essential properties of the C2-L1Tc protein as a NAC. PMID:19751212

  19. Nucleic-acid-binding properties of the C2-L1Tc nucleic acid chaperone encoded by L1Tc retrotransposon

    PubMed Central

    Heras, Sara R.; Thomas, M. Carmen; Macias, Francisco; Patarroyo, Manuel E.; Alonso, Carlos; López, Manuel C.

    2009-01-01

    It has been reported previously that the C2-L1Tc protein located in the Trypanosoma cruzi LINE (long interspersed nuclear element) L1Tc 3? terminal end has NAC (nucleic acid chaperone) activity, an essential activity for retrotransposition of LINE-1. The C2-L1Tc protein contains two cysteine motifs of a C2H2 type, similar to those present in TFIIIA (transcription factor IIIA). The cysteine motifs are flanked by positively charged amino acid regions. The results of the present study show that the C2-L1Tc recombinant protein has at least a 16-fold higher affinity for single-stranded than for double-stranded nucleic acids, and that it exhibits a clear preference for RNA binding over DNA. The C2-L1Tc binding profile (to RNA and DNA) corresponds to a non-co-operative-binding model. The zinc fingers present in C2-L1Tc have a different binding affinity to nucleic acid molecules and also different NAC activity. The RRR and RRRKEK [NLS (nuclear localization sequence)] sequences, as well as the C2H2 zinc finger located immediately downstream of these basic stretches are the main motifs responsible for the strong affinity of C2-L1Tc to RNA. These domains also contribute to bind single- and double-stranded DNA and have a duplex-stabilizing effect. However, the peptide containing the zinc finger situated towards the C-terminal end of C2-L1Tc protein has a slight destabilization effect on a mismatched DNA duplex and shows a strong preference for single-stranded nucleic acids, such as C2-L1Tc. These results provide further insight into the essential properties of the C2-L1Tc protein as a NAC. PMID:19751212

  20. In vitro effect of cyclophosphamide on the binding of radiopharmaceuticals (99mTcO4- and 99mTc-MDP) to blood elements.

    PubMed

    Ripoll-Hamer, E; Freitas, L C; De-Paula, E F; Fonseca, L M; Gutfilen, B; Bernardo-Filho, M

    1995-02-01

    Sodium pertechnetate (99mTcO4-) and many 99mTc-products are the radiopharmaceuticals most frequently used in nuclear medicine. Using an in vitro model, we evaluated the effect of cyclophosphamide on percent radioactivity of 99mTcO4- and methylenediphosphonic acid (99mTc-MDP) bound to isolated blood elements. Blood samples were incubated with the two radiopharmaceuticals, plasma and blood cells were separated and precipitated, and soluble and insoluble fractions were separated. To evaluate the effect of cyclophosphamide, blood was incubated with this drug 1 h prior to the addition of the radiopharmaceuticals. The fraction of 99mTcO4- radioactivity was slightly higher in plasma (61.2 to 53.8%) than in blood cells (38.8 to 46.2%) up to 6 h and cyclophosphamide did not interfere with this distribution. The amount of 99mTc-MDP radioactivity was higher in plasma (91.1 to 87.2%) than in blood cells (8.9 to 12.8%) up to 24 h and cyclophosphamide did not modify it. The binding of 99mTcO4- to the insoluble fraction of plasma (4.9 to 6.1%) was low and cyclophosphamide did not interfere with it up to 6 h, but a small blockade (9.8 to 4.8%) was observed at 24 h. From 3 h on, cyclophosphamide slightly inhibited 99mTcO4- binding to blood cells (23.1 to 16.6%) and increased it at 24 h (31.2 to 14.3%). Cyclophosphamide did not alter 99mTc-MDP binding to the insoluble fraction of blood cells and slightly decreased 99mTc-MDP binding to the insoluble fraction of plasma (29.8 to 23.6%) up to 6 h.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7581051

  1. The reinvestigation of the kinetics of the metathesis reactions t-C4H9• + HBr (HI) ? i-C4H10 + Br• (I•) and of the t-C4H9• free radical thermochemistry.

    PubMed

    Leplat, N; Rossi, M J

    2014-07-17

    A reinvestigation of the absolute rate constant of the metathesis reactions t-C4H9• + HBr ? i-C4H10 + Br• (1) and t-C4H9• + HI ? i-C4H10 + I• (2) was performed thanks to a recently developed apparatus consisting of a Knudsen reactor coupled to detection based on single-photon (VUV) photoionization mass spectrometry (SPIMS). It enables the generation of thermalized hydrocarbon free radicals owing to a source upstream of and external to the Knudsen reactor. The following Arrhenius expressions were obtained: k1 = 5.6(±1.4) × 10(–12) exp(?6.76(±0.94)/(RT)) and k2 = 2.0(±0.6) × 10(–11) exp(?8.48(±0.94)/(RT)) with R = 8.314 J mol(–1) K(–1) over the range 293 to 623 K. The mass balance of the reaction system based on closed shell product detection (CSPD) was checked in order to ensure the accuracy of the used reaction mechanism and as an independent check of k1 and k2. The wall-loss rate constants of the t-butyl free radical, kw(C4H9), were measured and found to be low compared with the corresponding escape rate constant, ke(C4H9), for effusion of t-C4H9• out of the Knudsen reactor. On the basis of the present results, the free radical standard heat of formation ?fH298°(t-C4H9•) = 44.3 ± 1.7 kJ mol(–1) was obtained when combined with the kinetics of the inverse halogenation reaction taken from the literature and using S298°(t-C4H9•) = 322.2 J K(–1) mol(–1) following a “Third Law” evaluation method. The standard enthalpy for t-butyl free radical is consistent for both the bromination and iodination reactions within the stated uncertainties. PMID:24942181

  2. Reappraising the relationship between mitochondrial DNA variant m.16189T>C and type 2 diabetes mellitus in East Asian populations.

    PubMed

    Zhong, L; Tang, J; Kong, Q-P; Sun, C; Zhou, W-P; Yang, M; Yao, Y-G; Zhang, Y-P

    2014-01-01

    The role of mitochondrial DNA (mtDNA) variant 16189T>C in type 2 diabetes mellitus (T2DM) remains hotly debated in the past decade. If mutation 16189T>C indeed posed a risk to T2DM, as echoed by some recent studies, correlation between this mutation and disease should be observed when carrying out a systematical study using data and samples collected in a large geographic region in China. To test this hypothesis, we first performed a linear regression analysis between the prevalence of T2DM and the allele frequency of 16189C variant in 10 East Asian populations, and further genotyped this variant in two casecontrol cohorts from west Han Chinese (Kunming and Xining). Linear regression analysis showed that no significant correlation was observed (r(2)=0.211, P=0.181), and the genotyping results indicated that the m.16189T>C frequency difference between case and control was not significant in either populations (P=0.38 and 0.89 for Kunming and Xining, respectively). Matrilineal backgrounds constitution (in terms of haplogroups) analysis generated a similar haplogroup distribution in both populations (P>0.1). All results failed to substantiate that m.16189T>C may play an active role in the development of T2DM in East Asian populations. PMID:25470290

  3. Development and biological evaluation of ??mTc-sulfonamide derivatives for in vivo visualization of CA IX as surrogate tumor hypoxia markers.

    PubMed

    Akurathi, Vamsidhar; Dubois, Ludwig; Celen, Sofie; Lieuwes, Natasja G; Chitneni, Satish K; Cleynhens, Bernard J; Innocenti, Alessio; Supuran, Claudiu T; Verbruggen, Alfons M; Lambin, Philippe; Bormans, Guy M

    2014-01-01

    In vivo visualization of tumor hypoxia related markers, such as the endogenous transmembrane protein CA IX may lead to novel therapeutic and diagnostic applications in the management of solid tumors. In this study 4-(2-aminoethyl)benzene sulfonamide (AEBS, K(i) = 33 nM for CA IX) has been conjugated with bis(aminoethanethiol) (BAT) and mercaptoacetyldiglycine (MAG2) tetradendate ligands and the conjugates radiolabelled with (99m)Tc, to obtain anionic and neutral (99m)Tc-labeled sulfonamide derivatives, respectively. The corresponding rhenium analogues were also prepared and showed good inhibitory activities against hCA IX (K(i) = 59-66 nM). In addition, a second generation bis AEBS was conjugated with MAG2 and labeled with (99m)Tc, and the obtained diastereomers were also evaluated in targeting CA IX. Biodistribution studies in mice bearing HT-29 colorectal xenografts revealed a maximum tumor uptake of <0.5% ID/g at 0.5 h p.i for all the tracers. In vivo radiometabolite analysis indicated that at 1 h p.i. MAG? tetradendate ligands were more stable in plasma (>50% intact) compared to the neutral complex (28% intact). This preliminary data suggest that negatively charged (99m)Tc-labeled sulfonamide derivatives with modest lipophilicity and longer circulation time could be promising markers to target CA IX. PMID:24378650

  4. Simultaneous determination of radioactive halogen isotopes and 99Tc

    NASA Astrophysics Data System (ADS)

    Kabai, E.; Vajda, N.; Gaca, P.

    2003-01-01

    The purpose of this study was to develop a simplified method for simultaneous determination of radiologically important halogen isotopes and 99Tc from different types of samples like environmental, biological and waste samples. Due to their long half-lives (longer than 105 years) they play important role in the nuclear cycle, especially in environmental monitoring and protection. For a rapid response in the evaluation of 129I, 36Cl and 99Tc contamination levels of these samples it is advantageous to combine the existing individual methods. According to the present procedure, iodine, chlorine and technetium are separated selectively from the same sample aliquot followed by the ß-spectrometry of the purified fractions. Increased sensitivities can be achieved by neutron activation (NA) especially in the case of 129I. Our work intends to solve the problem by combining the well-known hot acidic distillation method for iodine separation with the organic extraction process characteristic for technetium separation. The major objective of the work was to separate the disturbing halides from iodine. For this purpose a selective oxidant was applied. For the sample destruction and fractionated distillation an air flow-through installation was used with hot concentrated sulphuric and nitric acids. The trap for iodine contained 3 M NaOH solution. After iodine separation the trap was exchanged for a new one containing the same solution for trapping chlorine or bromine with an addition of 0.01 M KMnO4 solution as an oxidative agent. As expected, the main part of technetium was contained in the acidic residue after distillation. Tc purification was performed by organic extraction with TBP and TEVA column.

  5. Comparative metabolic behavior and interrelationships of Tc and S in soybean plants

    SciTech Connect

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.; Fellows, R.J. (Pacific Northwest Lab., Richland, WA (USA))

    1989-08-01

    The comparative behavior of sulfur (S) and technetium (Tc) in soybean seedlings shows gross subcellular distributions to be similar for these oxyanions. More than 75% of the tissue-deposited Tc remains soluble and extractable. Differences in Tc fixation/incorporation were noted for the nuclear and chloroplast fractions of leaf and root cells. Pulse studies showed that soluble protein and nitrate reductase levels rose in response to Tc accumulation by sink leaves but not source leaves. In vitro assay of chloroplast-based S reduction and incorporation systems showed Tc to be reduced and incorporated into amino nitrogen-containing products. A hypothesis related to the metabolic behavior of Tc in plants is presented.

  6. Tc-99m glucoheptonate is poor man's fluorodeoxyglucose

    PubMed Central

    Lele, Ramchandra D

    2011-01-01

    While fluoro-deoxy-glucose (FDG) has emerged as an important radiotracer for imaging tumors, myocardial viability and infection, the role of other glucose analogues should also be explored. Tc-99m Glucoheptonate (GHA) has been used for imaging brain tumors and lung tumors. The uptake mechanism may be linked to GLUT-1 (Glucose transporter) and GLUT-4 expression similar to FDG. GHA is easily available and cheap. With the availability of single photon emission computed tomography/computed tomography (SPECT/CT), GHA imaging should be re-explored as a tumor agent and also for imaging myocardial viability. PMID:23559709

  7. Surface impedance of the high-Tc oxide superconductors

    SciTech Connect

    Hylton, T.L.; Beasley, M.R.; Kapitulnik, A.; Carini, J.P.; Drabeck, L.

    1988-01-01

    We review briefly our results on measurements of the millimeter wave surface impedance of ceramic, thin film and single crystal samples of the high-Tc oxide superconductors. The observed losses and temperature dependences do not agree with BCS theory. We discuss our recent measurements of single crystal Bi(2)CaSr(2)Cu(2)O(x) and the effect of the application of a perpendicular magnetic field. We consider the possibilities of intrinsic and defect mechanisms to explain our observations. In particular, we discuss the effects of weakly coupled granular films on surface impedance.

  8. A new radiative heater for high Tc thin film growth

    NASA Astrophysics Data System (ADS)

    Badaye, M.; Gardner, M.; Wong, A.; Dosanjh, P.; Bonn, D.; Hardy, W. N.

    1998-09-01

    The design of a new radiative heater for the growth of oxide thin films is presented. A blackbody cavity approach has been used to eliminate the large temperature variations usually observed during the growth of high Tc (HTC) superconducting thin films. Results show that this simple and inexpensive design enables one to work without the need for in situ monitoring and constant adjustment of the substrate temperature. The performance of the new heater is demonstrated by the growth of excellent quality HTC thin films.

  9. Microstructures and critical currents in high-{Tc} superconductors

    SciTech Connect

    Suenaga, Masaki

    1998-11-01

    Microstructural defects are the primary determining factors for the values of critical-current densities in a high {Tc} superconductor after the electronic anisotropy along the a-b plane and the c-direction. A review is made to assess firstly what would be the maximum achievable critical-current density in YBa{sub 2}Cu{sub 3}O{sub 7} if nearly ideal pinning sites were introduced and secondly what types of pinning defects are currently introduced or exist in YBa{sub 2}Cu{sub 3}O{sub 7} and how effective are these in pinning vortices.

  10. Power Systems Development Facility Gasification Test Run TC10

    SciTech Connect

    Southern Company Services

    2002-12-30

    This report discusses Test Campaign TC10 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode of operation using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier during TC10 in air- (mainly for transitions and problematic operations) and oxygen-blown mode. Test Run TC10 was started on November 16, 2002, and completed on December 18, 2002. During oxygen-blown operations, gasifier temperatures varied between 1,675 and 1,825 F at pressures from 150 to 180 psig. After initial adjustments were made to reduce the feed rate, operations with the new fluidized coal feeder were stable with about half of the total coalfeed rate through the new feeder. However, the new fluidized-bed coal feeder proved to be difficult to control at low feed rates. Later the coal mills and original coal feeder experienced difficulties due to a high moisture content in the coal from heavy rains. Additional operational difficulties were experienced when several of the pressure sensing taps in the gasifier plugged. As the run progressed, modifications to the mills (to address processing the wet coal) resulted in a much larger feed size. This eventually resulted in the accumulation of large particles in the circulating solids causing operational instabilities in the standpipe and loop seal. Despite problems with the coal mills, coal feeder, pressure tap nozzles and the standpipe, the gasifier did experience short periods of stability during oxygenblown operations. During these periods, the syngas quality was high. During TC10, the gasifier gasified over 609 tons of Powder River Basin subbituminous coal and accumulated a total of 416 hours of coal feed, over 293 hours of which were in oxygen-blown operation. No sorbent was used during the run.

  11. Investigation of TC-1 flight failure using power spectral analysis

    NASA Technical Reports Server (NTRS)

    Lorenzo, C. F.

    1976-01-01

    During the Titan Centaur 1 test flight a failure involving at least one of the Centaur propellant boost pumps occurred. Also, neither of the boost pump speed instruments indicated pump rotation. Accelerometer data from the Titan Centaur 1 flight failure were analyzed using power spectral density methods to determine boost pump speed during attempted starts of the Centaur. The technique was demonstrated on a reference flight. The hydrogen boost pump speed transient was determined for the TC-1 flight. Other trends are seen in the data. However, these are not believed to be the oxygen boost pump. Discussion of data enhancement techniques is also presented.

  12. Synthesis, Radiolabeling and Biological Evaluation of 99mTc-labeled Deoxyglucose Derivatives for Molecular Imaging

    PubMed Central

    Sadeghzadeh, Masoud; Charkhlooiea, Ghorbanali; Johari Daha, Fariba

    2013-01-01

    Two deoxyglucose (DG) derivatives, (?,?)-2-deoxy-2-amino(ethylcarbamate)-D-glucose (ECB-DG) and (?,?)-2-deoxy-2-amino(1,2-dihydroxypropyl)-D-glucose (DHP-DG), were synthesized and radiolabeled successfully with [99mTc(H2O)3(CO)3]+ complex. [99mTc]-ECB-DG and [99mTc]-DHP-DG complexes were prepared (96% and 93% radiochemical purities respectively) by using 46 mCi of Na99mTcO4 in 1 mL saline. Radio-HPLC analysis of [99mTc]- ECB-DG at pH = 7.4, revealed that labeling with 99mTc leads to formation of one radiochemical species with tR = 381 second. Three radiochemical species, Na99mTcO4, [99mTc]-DHP-DG and [99mTc(H2O)3(CO)3]+ complexes with tR = 342 sec, tR = 567 sec and tR = 1586 sec respectively, were obtained when [99mTc]-DHP-DG complex evaluated by HPLC. Biodistribution of two complexes were studied on normal mice at 10, 30 and 60 min post-injections. Compared to the 18F-FDG, [99mTc]-ECB-DG displayed a 2.8-fold reduction in brain uptake (1.7 ± 0.2 versus 0.61% ± 0.09) ,whereas [99mTc]-DHP-DG just showed 1.9-fold reduction in heart uptake (2.2 ± 0.05 towards 1.16±0.10) at 1 h post-injection. On the basis of our results, it seems that ECB-DG and DHP-DG analogues could be used as brain and heart imaging agent respectively. PMID:24250633

  13. Renal dysplasia in infants: Apperance on 99m Tc DMSA scintigraphy

    Microsoft Academic Search

    P. J. Roach; H. J. Paltiel; A. Perez-Atayde; R. J. Tello; R. T. Davis; S. T. Treves

    1995-01-01

    Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy.99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than99mTc DTPA. We reviewed the ultrasound studies and99mTc DMSA scintigrams of 42 infants (age range 1–12 months) with known or suspected MCDK.

  14. Complexes of technetium(I) ( 99Tc, 99mTc) pentacarbonyl core with ?-acceptor ligands ( tert-butyl isocyanide and triphenylphosphine): Crystal structures of [Tc(CO) 5(PPh 3)]OTf and [Tc(CO) 5(CNC(CH 3) 3)]ClO 4

    Microsoft Academic Search

    A. E. Miroslavov; A. A. Lumpov; G. V. Sidorenko; E. M. Levitskaya; N. I. Gorshkov; D. N. Suglobov; R. Alberto; H. Braband; V. V. Gurzhiy; S. V. Krivovichev; I. G. Tananaev

    2008-01-01

    A procedure was developed for preparing [99mTcX(CO)5] (X=Cl, Br, I) in a reasonable yield by high-pressure carbonylation with CO of 99mTcO4? in aqueous solutions. In the synthesis, the substantial part of the target product is accumulated in the gas phase and can be transferred from the autoclave into various solvents when relieving the pressure. Compounds [99mTcX(CO)5] (X=Cl?, Br?, I?) are

  15. Incidental Detection of Intracranial Tuberculomas on 99mTc-TRODAT-1 SPECT/CT.

    PubMed

    Tripathi, Madhavi; Arora, Geetanjali; Das, Chandan J; Grover, Tripti; Gupta, Ranjan; Bal, Chandrasekhar

    2015-06-01

    Tc-TRODAT-1 has high affinity and specificity for dopamine transporters and is useful for the evaluation of presynaptic dopaminergic function, especially in parkinsonism. There have been a few reports of extrastriatal pathological accumulation of Tc-TRODAT-1. We report a patient with intracranial tuberculomas that were incidentally detected when he underwent Tc-TRODAT-1 scintigraphy for an unrelated indication. PMID:25608162

  16. Development of 99mTc-N4-NIM for Molecular Imaging of Tumor Hypoxia

    PubMed Central

    Ali, Mohammad S.; Kong, Fan-Lin; Rollo, Alex; Mendez, Richard; Kohanim, Saady; Smith, Daniel Lee; Yang, David J.

    2012-01-01

    The nitro group of 2-nitroimidazole (NIM) enters the tumor cells and is bioreductively activated and fixed in the hypoxia cells. 1,4,8,11-tetraazacyclotetradecane (N4) has shown to be a stable chelator for 99mTc. The present study was aimed to develop 99mTc-cyclam-2-nitroimidazole (99mTc-N4-NIM) for tumor hypoxia imaging. N4-NIM precursor was synthesized by reacting N4-oxalate and 1,3-dibromopropane-NIM, yielded 14% (total synthesis). Cell uptake of 99mTc-N4-NIM and 99mTc-N4 was obtained in 13762 rat mammary tumor cells and mesothelioma cells in 6-well plates. Tissue distribution of 99mTc-N4-NIM was evaluated in breast-tumor-bearing rats at 0.5–4?hrs. Tumor oxygen tension was measured using an oxygen probe. Planar imaging was performed in the tumor-bearing rat and rabbit models. Radiochemical purity of 99mTc-N4-NIM was >96% by HPLC. Cell uptake of 99mTc-N4-NIM was higher than 99mTc-N4 in both cell lines. Biodistribution of 99mTc-N4-NIM showed increased tumor-to-blood and tumor-to-muscle count density ratios as a function of time. Oxygen tension in tumor tissue was 6–10?mmHg compared to 40–50?mmHg in normal muscle tissue. Planar imaging studies confirmed that the tumors could be visualized clearly with 99mTc-N4-NIM in animal models. Efficient synthesis of N4-NIM was achieved. 99mTc-N4-NIM is a novel hypoxic probe and may be useful in evaluating cancer therapy. PMID:22719210

  17. Early Detection of Infarct in Reperfused Canine Myocardium Using 99mTc-Glucarate

    Microsoft Academic Search

    David R. Okada; Gerald Johnson III; Zhonglin Liu; Sonia D. Hocherman; Ban-An Khaw; Robert D. Okada

    99mTc-Glucarate is an infarct-avid imaging agent with the poten- tial for very early detection of myocardial infarction. The pur- poses of this study using a canine model were to determine (a) the time course of 99mTc-glucarate uptake and clearance from necrotic and normal myocardium; (b) the 99mTc-glucarate ne- crotic-to-normal activity ratio over time; (c) the time course of detectable scan

  18. Comparison of 99mTc-N-DBODC5 and 99mTc-MIBI of Myocardial Perfusion Imaging for Diagnosis of Coronary Artery Disease

    PubMed Central

    Ma, Haiyan; Li, Sijin; Wu, Zhifang; Liu, Jianzhong; Liu, Haiyan; Guo, Xiaoshan

    2013-01-01

    Despite recent advances in therapeutic and diagnostic approaches, coronary artery disease (CAD) and its related cardiac disorders represent the most common cause of death in the United States. Nuclear myocardial perfusion imaging (MPI) technologies play a pivotal role in the diagnosis and treatment design for CAD. Recently, in order to develop improved MPI agents for diagnosis of CAD, 99mTc-[bis(dimethoxypropylphosphinoethyl)-ethoxyethyl-amine(PNP5)]-[bis(N-ethoxyethyl)dithiocarbamato(DBODC)]nitride(N-DBODC5)(99mTc-N-DBODC5) with a faster liver clearance than conventional single-photon emission computed tomography (SPECT) imaging agents (technetium 99m sestamibi (99mTc-MIBI) or technetium 99m tetrofosmin) has been introduced. In preclinical and phase I studies, 99mTc-N-DBODC5 has shown characteristics of an essentially ideal MPI tracer. Importantly, however, there is no data to support the use of 99mTc-N-DBODC5 to evaluate myocardial ischemia in patients with suspected CAD. The present study was designed to assess the clinical value of this agent; the findings of stress and rest MPI after the administration of this agent were compared to those of stress and rest 99mTc-MIBI, as well as those of coronary angiography, with respect to the detection of CAD. Our findings indicated the usefulness of 99mTc-N-DBODC5 as a promising MPI agent. PMID:23841052

  19. Effective synthesis of 99mTc tricarbonyl complexes by microwave heating

    Microsoft Academic Search

    Naoya Harada; Hiroyuki Kimura; Masahiro Ono; Daisuke Mori; Yoshiro Ohmomo; Tetsuya Kajimoto; Hidekazu Kawashima; Hideo Saji

    2011-01-01

    Technetium-99m (99mTc) is one of the most frequently used nuclides for single-photon emission computed tomography (SPECT) imaging because of its radiochemical characteristics, such as gamma emission of suitable energy (141 keV) and adequate half-life (6.01 h). Although triaquatricarbonyl 99mTc cation ([99mTc(CO)3(H2O)3]+) has several advantages as a 99mTc-labeling agent, e.g., compact chelate size, chelate stability, and simplicity of preparation, its synthetic protocols should

  20. Toxicity of sup 99 Tc: Can it represent a risk to man

    SciTech Connect

    Gerber, G.B.; Hegela, M.; Vankerkom, J.; Kirchmann, R.; Maisin, J.R.; Lambiet-Collier, M. (Centre d'Etude de l'Energie Nucleaire CEN-SCK (Belgium))

    1989-08-01

    The movement through the environment and the toxicity to plants of {sup 99}Tc have been studied. However, information is scanty on {sup 99}Tc toxicity to mammals even though this is the decisive criterion for assessing the consequences of releases of Tc. A critical tissue could be the thyroid because of its preferential accumulation of Tc and the developing organism because of its greater radiosensitivity; moreover, this toxicity might be enhanced under conditions of a low iodine (I) diet. These questions were studied in rats given large amounts of {sup 99}Tc in either a normal or an I-deficient diet for several months starting 2 wk before mating. Newborns were continued on these diets after weaning. The parameters determined were: occurrence of pregnancy and litter size, triiodothyronine and thyroxin in serum, uptake of {sup 131}I by the thyroid 24 h after injection, histology of the thyroid and concentration of Tc in tissues of the mothers and their decendants. Thyroid damage, as well as the effects on pregnancy, could be observed after amounts of 10 micrograms Tc g-1 food. Iodine deficiency only slightly influences the {sup 99}Tc toxicity. The chemical and radiological toxicity of {sup 99}Tc to rats is small. Consequently, it seems unlikely that contamination levels in the environment would ever reach levels that could lead to serious non-stochastic effects, even in the developing organism.

  1. Lightning-Generated NO(x) Seen By OMI during NASA's TC-4 Experiment: First Results

    NASA Technical Reports Server (NTRS)

    Bucsela, Eric; Pickering, Kenneth E.; Huntemann, Tabitha; Cohen, Ronald; Perring, Anne; Gleason, James; Blakeslee, Richard; Navarro, Dylana Vargas; Segura, Ileana Mora; Hernandez, Alexia Pacheco; Laporte-Molina, Sadi

    2009-01-01

    We present here case studies identifying upper-tropospheric NO2 produced in convective storms during NASA's Tropical Composition, Cloud and Climate Coupling Experiment (TCi)n July and August 2007. DC8 aircraft missions, flown from the mission base in Costa Rica, recorded in situ NO2 profiles near active storms and in relatively quiet areas. We combine these data with measurements from the Ozone Monitoring Instrument (OMI) on the Aura satellite to estimate the amount of NO2 produced by lightning (LN02) above background levels in the regions influenced by storms. In our analysis, improved off-line processing techniques are employed to minimize known artifacts in the OM1 data. Information on lightning flashes (primarily CG) observed by the surface network operated by the Instituto Costarricense de Electricidad are examined upwind of regions where OM1 indicates enhanced LNO2. Comparisons of the observed flash data with measurements by the TRMM/LIS satellite instrument are used to obtain the lightning detection efficiency for total flashes. Finally, using the NO/NO2 ratio estimated from DC-8 observations, we estimate the average NO(x) production per lightning flash for each case in this study. The magnitudes of the measured NO(x) enhancements are compared with those observed by the DC-8 and with similar OM1 measurements analyzed in mid-latitude experiments.

  2. Moderately shielded high-Tc SQUID system for rat MCG

    NASA Astrophysics Data System (ADS)

    Bechstein, S.; Kim, I.-S.; Drung, D.; Novikov, I.; Schurig, Th

    2010-06-01

    Recently, we have developed a 5-channel high-Tc SQUID system with one signal channel intended for rat magnetocardiography (MCG) in moderately shielded or "quiet" real environment. This system is an adapted version of a human MCG system which has been improved with respect to user-friendliness and stability. A dewar with a cold-warm distance of 7 mm and a refill cycle time of up to one week is utilized. The implemented high-Tc SQUIDs are single-layer devices with grain boundary junctions fabricated at KRISS with laser ablation on 10 mm × 10 mm STO substrates. In order to cancel environmental magnetic noise, three of the five SQUIDs are arranged to build an axial software first-order or second-order gradiometer with a base line of 35 mm. The other two SQUIDs are used for balancing. To overcome previous system instabilities, we have implemented an Earth field compensation for each SQUID. For this, the SQUIDs were mounted in capsules containing integrated field compensation coils. The three Earth field components are measured with an additional triaxial fluxgate, and compensated at the SQUID locations using the low-noise current source of the SQUID readout electronics. This way, the SQUIDs can be cooled and operated in a low residual field that improves system stability and reduces low-frequency SQUID noise. It is even possible to slowly move the dewar in the Earth field (dynamic field compensation). Different noise cancellation procedures were optimized and compared employing a periodic signal source.

  3. Stereoscopic myocardial infarct imaging with Tc-99m pyrophosphate

    SciTech Connect

    Juni, J.E.; Meyers, L.J.; Nicholas, J.; Brown, G.

    1985-05-01

    Infarct-avid imaging of the heart with Tc-99m-pyrophosphate (PYP) has been shown to be highly sensitive for detection of transmural infarction. It's poor sensitivity for non-transmural infarcts has limited its clinical applicability. Recent reports of tomographic PYP imaging have demonstrated a marked improvement in sensitivity due to the ability to separate cardiac from overlying rib activity. Unfortunately, SPECT imaging is not yet universally available. The authors have investigated the use of stereoscopic PYP imaging from multiple planar views to enhance this three-dimensional separation of heart and ribs without requiring special equipment. The patient is given i.v. Tc-PYP followed by a standard 3 hour delay. Planar images of 500-1000K counts are obtained on a standard gamma camera and computer at 10/sup 0/ intervals extending from the anterior to the left lateral view. In addition to analog images, the data is stored digitally in a 128x128 image matrix. Similar results may be obtained by displaying black and white images side by side on screen or film and viewing them through a pair of lenses adjusted such that each eye sees only one image. Stereoscopic PYP imaging makes the differentiation of cardiac and rib activity much clearer than planar images alone and requires a minimal investment in time or materials. It may be useful when SPECT imaging is not available.

  4. Nonlinear vibration of a coupled high- Tc superconducting levitation system

    NASA Astrophysics Data System (ADS)

    Sugiura, T.; Inoue, T.; Ura, H.

    2004-10-01

    High- Tc superconducting levitation can be applied to electro-mechanical systems, such as flywheel energy storage and linear-drive transportation. Such a system can be modeled as a magnetically coupled system of many permanent magnets and high- Tc superconducting bulks. It is a multi-degree-of-freedom dynamical system coupled by nonlinear interaction between levitated magnets and superconducting bulks. This nonlinearly coupled system, with small damping due to no contact support, can easily show complicated phenomena of nonlinear dynamics. In mechanical design, it is important to evaluate this nonlinear dynamics, though it has not been well studied so far. This research deals with forced vibration of a coupled superconducting levitation system. As a simple modeling of a coupled system, a permanent magnet levitated above a superconducting bulk is placed between two fixed permanent magnets without contact. Frequency response of the levitated magnet under excitation of one of the fixed magnets was examined theoretically. The results show typical nonlinear vibration, such as jump, hysteresis, and parametric resonance, which were confirmed in our numerical analyses and experiments.

  5. TcNPR3 from Theobroma cacao functions as a repressor of the pathogen defense response

    PubMed Central

    2013-01-01

    Background Arabidopsis thaliana (Arabidopsis) NON-EXPRESSOR OF PR1 (NPR1) is a transcription coactivator that plays a central role in regulating the transcriptional response to plant pathogens. Developing flowers of homozygous npr3 mutants are dramatically more resistant to infection by the pathogenic bacterium Pseudomonas syringae, suggesting a role of NPR3 as a repressor of NPR1-mediated defense response with a novel role in flower development. Results We report here the characterization of a putative NPR3 gene from the tropical tree species Theobroma cacao (TcNPR3). Like in Arabidopsis, TcNPR3 was constitutively expressed across a wide range of tissue types and developmental stages but with some differences in relative levels compared to Arabidopsis. To test the function of TcNPR3, we performed transgenic complementation analysis by introducing a constitutively expressing putative TcNPR3 transgene into an Arabidopsis npr3 mutant. TcNPR3 expressing Arabidopsis plants were partially restored to the WT pathogen phenotype (immature flowers susceptible to bacterial infection). To test TcNPR3 function directly in cacao tissues, a synthetic microRNA targeting TcNPR3 mRNA was transiently expressed in cacao leaves using an Agrobacterium-infiltration method. TcNPR3 knock down leaf tissues were dramatically more resistance to infection with Phytophthora capsici in a leaf bioassay, showing smaller lesion sizes and reduced pathogen replication. Conclusions We conclude that TcNPR3 functions similar to the Arabidopsis NPR3 gene in the regulation of the cacao defense response. Since TcNPR3 did not show a perfect complementation of the Arabidopsis NPR3 mutation, the possibility remains that other functions of TcNPR3 remain to be found. This novel knowledge can contribute to the breeding of resistant cacao varieties against pathogens through molecular markers based approaches or biotechnological strategies. PMID:24314063

  6. {sup 99}Tc bioassay: A direct comparison of liquid scintillation radiation detection and ICP-MS mass detection of the {sup 99}Tc isotope

    SciTech Connect

    Lewis, L.A. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States). Analytical Services Organization; Schweitzer, G.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry

    1998-12-31

    A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max.} beta decay product by liquid scintillation or gas flow proportional counting. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard manual quench correction and an automatic quench curve correction method are compared with results obtained by ICP-MS. Each method produced accurate results; however, the precision of the ICP-MS results is superior to that of liquid scintillation results.

  7. 99mTc-3P4-RGD2 Scintimammography in the Assessment of Breast Lesions: Comparative Study with 99mTc-MIBI

    PubMed Central

    Gao, Shi; Ji, Tiefeng; Wen, Qiang; Song, Yan; Zhu, Lei; Xu, Zheli; Liu, Lin

    2014-01-01

    Purpose To compare the potential application of 99mTc-3P-Arg-Gly-Asp (99mTc-3P4-RGD2) scintimammography (SMM) and 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SMM for the differentiation of malignant from benign breast lesions. Method Thirty-six patients with breast masses on physical examination and/or suspicious mammography results that required fine needle aspiration cytology biopsy (FNAB) were included in the study. 99mTc-3P4-RGD2 and 99mTc-MIBI SMM were performed with single photon emission computed tomography (SPECT) at 60 min and 20 min respectively after intravenous injection of 738±86 MBq radiotracers on a separate day. Images were evaluated by the tumor to non-tumor localization ratios (T/NT). Receiver operating characteristic (ROC) curve analysis was performed on each radiotracer to calculate the cut-off values of quantitative indices and to compare the diagnostic performance for the ability to differentiate malignant from benign diseases. Results The mean T/NT ratio of 99mTc-3P4-RGD2 in malignant lesions was significantly higher than that in benign lesions (3.54±1.51 vs. 1.83±0.98, p<0.001). The sensitivity, specificity, and accuracy of 99mTc-3P4-RGD2 SMM were 89.3%, 90.9% and 89.7%, respectively, with a T/NT cut-off value of 2.40. The mean T/NT ratio of 99mTc-MIBI in malignant lesions was also significantly higher than that in benign lesions (2.86±0.99 vs. 1.51±0.61, p<0.001). The sensitivity, specificity and accuracy of 99mTc-MIBI SMM were 87.5%, 72.7% and 82.1%, respectively, with a T/NT cut-off value of 1.45. According to the ROC analysis, the area under the curve for 99mTc-3P4-RGD2 SMM (area?=?0.851) was higher than that for 99mTc-MIBI SMM (area?=?0.781), but the statistical difference was not significant. Conclusion 99mTc-3P4-RGD2 SMM does not provide any significant advantage over the established 99mTc-MIBI SMM for the detection of primary breast cancer. The T/NT ratio of 99mTc-3P4-RGD2 SMM was significantly higher than that of 99mTc-MIBI SMM. Both tracers could offer an alternative method for elucidating non-diagnostic mammograms. PMID:25250628

  8. Synthesis, structure elucidation and redox properties of 99Tc complexes of lacunary Wells Dawson polyoxometalates: insights into molecular 99Tc - metal oxide interactions

    SciTech Connect

    McGregor, Donna; Burton-Pye, Benjamin P.; Howell, Robertha C.; Mbomekalle, Israel M.; Lukens Jr, Wayne W.; Bian, Fang; Mausolf, Edward; Poineau, Frederic; Czerwinski, Kenneth R; Francesconi, Lynn C.

    2011-01-10

    The isotope 99Tc (beta max: 250 keV, half-life: 2 x 105 year) is an abundant product of uranium-235 fission in nuclear reactors and is present throughout the radioactive waste stored in underground tanks at Hanford and Savannah River. Understanding and controlling the extensive redox chemistry of 99Tc is important to identify tunable strategies to separate 99Tc from spent fuel and from waste tanks and once separated, to identify and develop an appropriately stable waste-form for 99Tc. Polyoxometalates (POMs), nanometer sized models for metal oxide solid-state materials, are used in this study to provide a molecular level understanding of the speciation and redox chemistry of incorporated 99Tc. In this study, 99Tc complexes of the (alpha 2-P2W17O61)10- and (alpha 1-P2W17O61)10- isomers were prepared. Ethylene glycol was used as a"transfer ligand" to minimize the formation of TcO2 cdot xH2O. The solution structures, formulations, and purity of TcVO(alpha 1/alpha 2-P2W17O61)7- were determined by multinuclear NMR. X-ray Absorption Spectroscopy of the complexes are in agreement with the formulation and structures determined from 31P and 183W NMR. Preliminary electrochemistry results are consistent with the EXAFS results, showing a facile reduction of the TcVO(alpha 1-P2W17O61)7- species compared to the TcVO(alpha 2-P2W17O61)7- analog. The alpha1- defect is unique in that a basic oxygen atom is positioned toward the alpha1- site and the TcVO center appears to form a dative metal-metal bond with a framework W site. These attributes may lead to the assistance of protonation events that facilitate reduction. Electrochemistry comparison shows that the ReV analogs are about 200 mV more difficult to reduce in accordance with periodic trends.

  9. Synthesis, Structure Elucidation, and Redox Properties of [superscript 99]Tc Complexes of Lacunary Wells-Dawson Polyoxometalates: Insights into Molecular [superscript 99]Tc-Metal Oxide Interactions

    SciTech Connect

    McGregor, Donna; Burton-Pye, Benjamin P.; Howell, Robertha C.; Mbomekalle, Israel M.; Lukens, Jr., Wayne W.; Bian, Fang; Mausolf, Edward; Poineau, Frederic; Czerwinski, Kenneth R.; Francesconi, Lynn C. (UNLV); (City U/NY)

    2011-11-17

    The isotope {sup 99}Tc ({beta}{sub max}, 293.7; half-life, 2.1 x 10{sup 5} years) is an abundant product of uranium-235 fission in nuclear reactors and is present throughout the radioactive waste stored in underground tanks at the Hanford and Savannah River sites. Understanding and controlling the extensive redox chemistry of {sup 99}Tc is important in identifying tunable strategies to separate {sup 99}Tc from spent fuel and from waste tanks and, once separated, to identify and develop an appropriately stable waste form for {sup 99}Tc. Polyoxometalates (POMs), nanometer-sized models for metal oxide solid-state materials, are used in this study to provide a molecular level understanding of the speciation and redox chemistry of incorporated {sup 99}Tc. In this study, {sup 99}Tc complexes of the ({alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 10-} and ({alpha}{sub 1}-P{sub 2}W{sub 17}O{sub 61}){sup 10-} isomers were prepared. Ethylene glycol was used as a 'transfer ligand' to minimize the formation of TcO{sub 2} {center_dot} xH{sub 2}O. The solution structures, formulations, and purity of TcVO({alpha}{sub 1}/{alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 7-} were determined by multinuclear NMR. X-ray absorption spectroscopy of the complexes is in agreement with the formulation and structures determined from {sup 31}P and {sup 183}W NMR. Preliminary electrochemistry results are consistent with the EXAFS results, showing a facile reduction of the TcVO({alpha}{sub 1}-P{sub 2}W{sub 17}O{sub 61}){sup 7-} species compared to the TcVO({alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}){sup 7-} analog. The {alpha}{sub 1} defect is unique in that a basic oxygen atom is positioned toward the {alpha}{sub 1} site, and the Tc{sup V}O center appears to form a dative metal-metal bond with a framework W site. These attributes may lead to the assistance of protonation events that facilitate reduction. Electrochemistry comparison shows that the ReV analogs are about 200 mV more difficult to reduce in accordance with periodic trends.

  10. Negative correlation between therapeutic success in radioiodine therapy and TcTUs: are TcTUs-adapted dose concepts the only possible answer?

    Microsoft Academic Search

    Martin Gotthardt; Miriam Nowack; Martin P. Béhé; Meike L. Schipper; Anja Schlieck; Helmut Höffken; Thomas M. Behr

    2003-01-01

    Calculation of iodine-131 activities for radioiodine treatment (RIT) in patients with disseminated thyroid autonomy may be difficult because of uncertainties in the determination of the autonomous volume (vol aut). The algorithm established by Emrich is used for calculation of the vol aut based on the TcTUs (technetium thyroid uptake under TSH suppression) (vol aut= 5×TcTUs+0.6). Clinical experience using this approach

  11. 99 m Tc-sulphur-colloid and heat-denatured 99 m Tc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy

    Microsoft Academic Search

    P.-F. Kao; Kai-Yuan Tzen; Ming-Fong Tsai; Jer-Nan Lin

    2001-01-01

    A 17 × 12 × 5-cm giant intrapelvic mass in a 14-year-old girl is reported. This mass developed 6 years after a splenectomy\\u000a for splenic torsion. The heat-denatured 99 mTc-labelled red cell scan and 99 mTc- sulphur-colloid scan confirmed the specific red cell sequestration function and reticuloendothelial activity in the giant\\u000a intrapelvic spleen. The size and development of the giant

  12. Magnetic and thermal properties of high Tc superconductors

    SciTech Connect

    Lee, Wonchoon.

    1990-09-21

    Measurements of the normal state magnetic susceptibility {chi}(T) of YBa{sub 2}Cu{sub 3}O{sub 7}, Bi{sub 1.8}Pb{sub 0.2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}, and Bi{sub 2{minus}x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{delta}} (x = 0.2 and 0.25) were carried out. All {chi}(T) data show negative curvature below {approximately}2{Tc}. The data for YBa{sub 2}Cu{sub 3}O{sub 7} are in excellent agreement with a new calculation of the superconducting fluctuation diamagnetism. From the analysis, we infer s-wave pairing and microscopic parameters are obtained. For {chi}(T) of YBa{sub 2}Cu{sub 3}O{sub 7}, part of the negative curvature is inferred to arise from the normal state background. We find a strong temperature dependent anisotropy {delta}{chi} {equivalent to} {chi}{sub c} {minus} {chi}{sub ab} and estimate the normal state spin contributions to {chi}(T). The heat capacity C(T) of YBa{sub 2}Cu{sub 3}O{sub 7} is reported for 0.4 K < T < 400 K in zero and 70 kG magnetic fields. In addition to the feature associated with the onset of the superconductivity at {Tc}, two anomalies in C(T) were observed near 74 K and 330 K, with another possible anomaly near 102 K; the temperatures at which they occur correlate with anomalies in {chi}(T) and ultransonic measurements. The occurrence of the anomaly at {approx equal} 330 K is found to be sample-dependent. The influences of a magnetic field and the thermal and/or magnetic field treatment history dependence of a pellet sample on C(T), the entropy and the influence of superconducting fluctuations on C(T) near {Tc}, and the possible source of the observed intrinsic nonzero {gamma}(0) at low T are discussed.

  13. Reductive Sequestration Of Pertechnetate (99TcO4–) By Nano Zerovalent Iron (nZVI) Transformed By Abiotic Sulfide

    SciTech Connect

    Fan, Dimin; Anitori, Roberto; Tebo, Bradley M.; Tratnyek, Paul G.; Lezama Pacheco, Juan S.; Kukkadapu, Ravi K.; Engelhard, Mark H.; Bowden, Mark E.; Kovarik, Libor; Arey, Bruce W.

    2013-04-24

    Under anoxic conditions, soluble 99TcO4– can be reduced to less soluble TcO2•nH2O, but the oxide is highly susceptible to reoxidation. Here we investigate an alternative strategy for remediation of Tc-contaminated groundwater whereby sequestration as Tc sulfide is favored by sulfidic conditions stimulated by nano zero-valent iron (nZVI). nZVI was pre-exposed to increasing concentrations of sulfide in simulated Hanford groundwater for 24 hrs to mimic the stages of aquifer sulfate reduction and onset of biotic sulfidogenesis. Solid-phase characterizations of the sulfidated nZVI confirmed the formation of nanocrystalline FeS phases, but higher S/Fe ratios (>0.112) did not result in the formation of significantly more FeS. The kinetics of Tc sequestration by these materials showed faster Tc removal rates with increasing S/Fe between S/Fe = 0–0.056, but decreasing Tc removal rates with S/Fe > 0.224. The more favorable Tc removal kinetics at low S/Fe could be due to a higher affinity of TcO4– for FeS (over iron oxides), and electron microscopy confirmed that the majority of the Tc was associated with FeS phases. The inhibition of Tc removal at high S/Fe appears to have been caused by excess HS–. X-ray absorption spectroscopy revealed that as S/Fe increased, Tc speciation shifted from TcO2•nH2O to TcS2. The most substantial change of Tc speciation occurred at low S/Fe, coinciding with the rapid increase of Tc removal rate. This agreement further confirms the importance of FeS in Tc sequestration.

  14. Recap Text classification Naive Bayes NB theory Evaluation of TC Introduction to Information Retrieval

    E-print Network

    Nejdl, Wolfgang

    Recap Text classification Naive Bayes NB theory Evaluation of TC Introduction to Information Retrieval http://informationretrieval.org IIR 13: Text Classification & Naive Bayes Hinrich Sch¨utze Center Bayes 1 / 58 #12;Recap Text classification Naive Bayes NB theory Evaluation of TC Overview 1 Recap 2

  15. A new mechanism for high-[Tc]: Electron scattering from interacting tunneling units

    SciTech Connect

    Klein, M.W.; Simanovsky, S.B. (Worcester Polytechnic Inst., MA (United States). Dept. of Physics)

    1998-12-20

    A theoretical model for high-[Tc] superconductivity is presented based on electron pairing due to their interaction with two-level or multi-level tunneling units (TU's) present in high-[Tc] materials. TU's were found experimentally in YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta

  16. Preparation of 99mTc-Clomiphene Citrate as a Novel Agent for Breast Cancer Imaging

    PubMed Central

    Ibrahim, Ismail Taha; Elkolally, Mohamed Taha; Abd Elgany, Ibrahim Yousof; Abd Albary, Ahmed; Hodhod Elsayed, Mohamed

    2012-01-01

    The aim of this work was to develop a novel 99mTc-labelled derivative based on triphenylethylene for breast cancer imaging. 99mTc-Clomiphene was obtained with a radiochemical yield of 94.4% by adding 99mTc to 1.5?mg Clomiphene citrate in the presence of 10??g SnCl2 at pH 7. The optimization of the labeling yield of Clomiphene citrate, with 99mTc, is described. The reaction parameters that affect the labeling yield were studied to optimize the labeling conditions. Radiochemical purity of the final product has been verified by means of paper chromatography and paper electrophoresis. Ehrlich Ascites Carcinoma (EAC) as a model of breast cancer cells was injected intraperitoneally (IP) to produce ascites and intramuscularly (IM) to produce solid tumor. Biodistribution study was carried out by the injecting solution of 99mTc-Clomiphene in normal and tumor bearing mice. The uptake in ascites was over 12.5 % injected dose per gram tissue body weight, at 1hr after injection and above 12% in solid tumor. The T/NT value for 99mTc-Clomiphene complex was found to be 5.5 ± 0.4 which was higher than that of the commercially available 99mTc-MIBI. This data revealed the localization of tracer in tumor tissue with high percent sufficient to use 99mTc-Clomiphene as a promising tool for the diagnosis of breast cancer. PMID:23213567

  17. Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids

    E-print Network

    Zare, Richard N.

    Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids Hassan SABBAH1* , Amy L. MORROW1 , Peter JENNISKENS2 , Muawia H. SHADDAD3 , and Richard N. ZARE1. Among the predominantly polymict ureilite meteorites collected from the impact of asteroid 2008 TC3

  18. Double Star TC1 observations of component reconnection at the dayside magnetopause: a preliminary study

    Microsoft Academic Search

    Z. Y. Pu; C. J. Xiao; X. G. Zhang; Z. Y. Huang; S. Y. Fu; Z. X. Liu; M. W. Dunlop; Q. G. Zong; C. M. Carr; H. Réme; I. Dandouras; A. Fazakerley; T. Phan; T. L. Zhang; H. Zhang; X. G. Wang

    2005-01-01

    In spring 2004 Double Star TC-1 measured a number of reconnection signatures at the dayside low-latitude magnetopause (MP) when there was a notable By component in the magnetosheath. In a number of events we can show that reconnection was operating nearby TC-1 in the subsolar MP region. In this paper we describe three representative events: (a) event on 21 March

  19. M(^\\/71\\ Ris-M-2739 3 Determination of "Tc in

    E-print Network

    . The evaporation rates of Ru04 and Tc04~ are determined at 100°C in 0.1 N H2S04. A higher decontamination factor 2/xylene extraction at controlled valence are used for decontamination of ruthenium, »°n>Ag and other nuclides Experimental S Procedure 6 Principle 6 Determination of die chemical yield of"Tc and decontamination factor for

  20. 99mTc-HMDP accumulation in a phyllodes tumor of the breast, a case report.

    PubMed

    Ohta, H; Komibuchi, T; Adachi, R; Otani, H; Takeda, H; Hamazaki, K; Shimizu, K; Taniguchi, T; Irie, K; Yamamoto, K

    1993-02-01

    In a patient with breast tumor, 99mTc-HMDP accumulation in the tumor was recognized in evaluating bone metastasis. Surgery and histopathology revealed that the tumor was a phyllodes tumor. This scintigraphic finding was thought to be rare and phyllodes tumor should be included in differential diagnosis when 99mTc-HMDP accumulation in the breast was recognized. PMID:8384869

  1. Use of combustion apparatus for low-level ⁹⁹Tc separations from soil samples

    Microsoft Academic Search

    Keiko Tagami; Shigeo Uchida

    1999-01-01

    Analysis data of global fallout ⁹⁹Tc in environmental samples should give useful information for predicting the nuclide's behavior. However, due to its low concentration and analytical difficulties with environmental samples, there are not many data. The authors improved a simple separation method, which had been previously reported for Tc in soil samples and used a combustion apparatus. In this study,

  2. [Evaluation of liver function in carbon tetrachloride-damaged rabbits by dynamic SPECT: comparison of 99mTc-GSA and 99mTc-Sn colloid].

    PubMed

    Kiuchi, T; Kawasaki, Y; Hino, I; Kojima, K; Ohkawa, M; Tamai, T; Tanabe, M

    1994-09-25

    Technetium-99m-DTPA-galactosyl human serum albumin (99mTc-GSA) is a new ligand that binds specifically to asialoglycoprotein receptors in hepatocytes. We performed liver dynamic SPECT using 99mTc-GSA and 99mTc-Sn colloid in nine normal control rabbits and 17 chronically CCI4-damaged rabbits (total 29 examinations), and also performed liver function tests (ICGR15, Alb, etc). Using the obtained dynamic SPECT data, we analyzed the liver kinetics of 99mTc-Sn colloid using a one-compartment model (hepatic blood flow [K]) and 99mTc-GSA using a two-compartment model (hepatic blood flow and receptor binding [K1], catabolism [K2]). As the CCl4-treated period increased, K1 decreased most significantly. K1 showed the most significant statistical correlation with the results of liver function tests, ICGR15 (p < 0.0001), Alb, PT, HP, Bil and GPT. Further, only K1 showed a correlation with the hepatic fibrosis of the HAI score. From the present results, liver dynamic SPECT using 99mTc-GSA may be said to provide a novel method for the evaluation of hepatic functional reserve. PMID:7971180

  3. Heterogeneous Reduction of Tc(VII) by Fe(II) at the Solid-Water Interface

    SciTech Connect

    Peretyazhko, Tetyana; Zachara, John M.; Heald, Steve M.; Jeon, Byong Hun; Kukkadapu, Ravi K.; Liu, Chongxuan; Moore, Dean A.; Resch, Charles T.

    2008-03-15

    Technetium-99 is a byproduct of uranium fission. It exists in two stable valence states (IV/VII) and exhibits a half-cell potential of intermediate value (Eo = 0.748 V). The oxidized form of 99Tc [pertechnetate, TcO4-] is an oxyanion that sorbs poorly to amphoteric surfaces and forms few solid phases with geochemically relevant cations. It is consequently highly mobile in oxic water-rock systems. The reduced valence state [Tc(IV)] is relatively insoluble (<10-8 mol L-1), and, hence immobile as an oxyhydroxide precipitate [TcO2•nH2O(s)]. In spite of favorable thermodynamics, Tc(VII) reacts slowly with Fe2+(aq) under anoxic conditions. Experiments were performed herein to investigate the rates and products of heterogeneous reduction of Tc(VII) by Fe(II) sorbed to hematite and goethite, and by structural Fe(II) in a dithionite-citrate-bicarbonate (DCB) reduced natural phyllosilicate mixture containing vermiculite, illite, and muscovite. The heterogeneous reduction of Tc(VII) by Fe(II) sorbed to the Fe(III) oxides increased with increasing pH and was coincident with a second event of Fe2+(aq) adsorption. The reaction was almost instantaneous above pH 7. In contrast, the reduction rates of Tc(VII) by structural Fe(II) in the DCB-reduced phyllollsilicates, were not sensitive to pH or the concentration of ion-exchangeable Fe(II), and were orders of magnitude slower than observed for the Fe(III) oxides. Tc-EXAFS spectroscopy revealed that the reduction products were virtually identical on hematite and goethite that were comprised primarily of sorbed octahedral TcO2 monomers and dimers with significant Fe(III) in the second coordination shell. The nature of heterogeneous Fe(III) resulting from the redox reaction was ambiguous as probed by Tc-EXAFS spectroscopy, although Mössbauer spectroscopy applied to an experiment with 56Fe-goethite with adsorbed 57Fe(II) implied that redox product Fe(III) was goethite-like. The Tc(IV) reduction product formed on the DCB-reduced phyllosilicates was different from the Fe(III) oxides, and was more similar to Tc(IV) oxyhydroxide in its second coordination shell. The heterogeneous reduction of Tc(VII) to less soluble forms by sorbed and structural Fe(II) in anoxic environments may be a very important geochemical process that will proceed at very different rates and that will yield different surface species depending subsurface pH and mineralogy.

  4. Buffer layers for high-Tc thin films on sapphire

    NASA Technical Reports Server (NTRS)

    Wu, X. D.; Foltyn, S. R.; Muenchausen, R. E.; Cooke, D. W.; Pique, A.; Kalokitis, D.; Pendrick, V.; Belohoubek, E.

    1992-01-01

    Buffer layers of various oxides including CeO2 and yttrium-stabilized zirconia (YSZ) have been deposited on R-plane sapphire. The orientation and crystallinity of the layers were optimized to promote epitaxial growth of YBa2Cu3O(7-delta) (YBCO) thin films. An ion beam channeling minimum yield of about 3 percent was obtained in the CeO2 layer on sapphire, indicating excellent crystallinity of the buffer layer. Among the buffer materials used, CeO2 was found to be the best one for YBCO thin films on R-plane sapphire. High Tc and Jc were obtained in YBCO thin films on sapphire with buffer layers. Surface resistances of the YBCO films were about 4 mOmega at 77 K and 25 GHz.

  5. Growth of high Tc superconducting thin films for microwave applications

    SciTech Connect

    Wu, X.D.; Foltyn, S.R.; Muenchausen, R.E.; Dye, R.C.; Cooke, D.W.; Rollett, A.D.; Garcia, A.R.; Nogar, N.S. (Los Alamos National Lab., NM (USA)); Pique, A.; Edwards, R. (Neocera, New Brunswick, NJ (USA))

    1991-01-01

    High-{Tc} superconducting thin films of YBa{sub 2}Cu{sub 3}O{sub 7 {minus}{delta}} (YBCO) were deposited on sapphire substrates with buffer layers of yttria-stabilized zirconia and cerium oxide by using pulsed laser deposition (PLD) technique. The epitaxial relationship between the substrate and buffer layers as well as the buffer layer and the superconducting film was established. Furthermore, using the same thin film technique, YBCO superconducting thin films were deposited on both sides of substrates of up to 5 cm in diameter. The superconducting properties of the films on both the sapphire with buffer layers and large-area substrates were comparable to the ones of the best YBCO films. 8 refs., 6 figs.

  6. Reply to ``Comment on `Isotope effect in high- Tc superconductors' ''

    NASA Astrophysics Data System (ADS)

    Harshman, Dale R.; Dow, John D.; Fiory, Anthony T.

    2009-10-01

    Our paper on the isotope effect in high-temperature superconductors with cation substitutions presents a comprehensive analysis rooted completely in the experimental evidence. In this Reply we show that pair-breaking disorder, isotope effects, doping-induced variations in Tc and in the magnetic penetration depth, Coulomb’s law, and Anderson’s theorem are treated with correct physical and mathematical fundamentals. In contrast, the theory fostered in the Comment by Alexandrov and Zhao contradicts several specific experimental facts, eight of which are briefly discussed. Their Comment also uncritically repeats a previously discredited assertion of an isotope effect in the superconducting carrier mass, incorrectly assumes that cation doping continuously varies intrinsic superconducting parameters, unjustifiably assigns importance to data from samples with serious quality problems, and renders a false estimate of the pair-breaking strength.

  7. Inhomogeneous Electronic Distribution in High-Tc Cuprates

    NASA Astrophysics Data System (ADS)

    Koikegami, Shigeru; Kato, Masaru; Yanagisawa, Takashi

    2015-05-01

    We theoretically investigate the doping evolution of the electronic state of high-Tc cuprate on both sides of the half-filling on the basis of the three-dimensional three-band Hubbard model with a layered structure using the Hartree-Fock approximation. Once a small amount of holes or electrons are doped into the half-filled state, our model exhibits the charge-transfer insulator-to-metal transition along with a chemical potential jump. At the same time, the doped holes or electrons are inhomogeneously distributed, and they tend to form clusters in the vicinity of the half-filling. This suggests the possibility of microscopic phase separation with the separation between the metallic and the insulating regions.

  8. Origin of the high Néel temperature in SrTcO3.

    PubMed

    Mravlje, Jernej; Aichhorn, Markus; Georges, Antoine

    2012-05-11

    We investigate the origin of the high Néel temperature recently found in Tc4+ perovskites. The electronic structure in the magnetic state of SrTcO3 and its 3d analogue SrMnO3 is calculated within a framework combining band-structure and many-body methods. In agreement with experiment, for SrTcO3 a smaller magnetic moment and 4 times larger Néel temperature are found. We show that this is because the Tc compound lies on the verge of the itinerant-to-localized transition, while the Mn compound lies deeper into the localized side. For SrTcO3 we predict that the Néel temperature depends weakly on applied pressure, in clear violation of Bloch's rule, signaling the complete breakdown of the localized picture. PMID:23003080

  9. Massively Parallel Sequencing Reveals the Complex Structure of an Irradiated Human Chromosome on a Mouse Background in the Tc1 Model of Down Syndrome

    PubMed Central

    Clayton, Stephen; Prigmore, Elena; Langley, Elizabeth; Yang, Fengtang; Maguire, Sean; Fu, Beiyuan; Rajan, Diana; Sheppard, Olivia; Scott, Carol; Hauser, Heidi; Stephens, Philip J.; Stebbings, Lucy A.; Ng, Bee Ling; Fitzgerald, Tomas; Quail, Michael A.; Banerjee, Ruby; Rothkamm, Kai; Tybulewicz, Victor L. J.; Fisher, Elizabeth M. C.; Carter, Nigel P.

    2013-01-01

    Down syndrome (DS) is caused by trisomy of chromosome 21 (Hsa21) and presents a complex phenotype that arises from abnormal dosage of genes on this chromosome. However, the individual dosage-sensitive genes underlying each phenotype remain largely unknown. To help dissect genotype – phenotype correlations in this complex syndrome, the first fully transchromosomic mouse model, the Tc1 mouse, which carries a copy of human chromosome 21 was produced in 2005. The Tc1 strain is trisomic for the majority of genes that cause phenotypes associated with DS, and this freely available mouse strain has become used widely to study DS, the effects of gene dosage abnormalities, and the effect on the basic biology of cells when a mouse carries a freely segregating human chromosome. Tc1 mice were created by a process that included irradiation microcell-mediated chromosome transfer of Hsa21 into recipient mouse embryonic stem cells. Here, the combination of next generation sequencing, array-CGH and fluorescence in situ hybridization technologies has enabled us to identify unsuspected rearrangements of Hsa21 in this mouse model; revealing one deletion, six duplications and more than 25 de novo structural rearrangements. Our study is not only essential for informing functional studies of the Tc1 mouse but also (1) presents for the first time a detailed sequence analysis of the effects of gamma radiation on an entire human chromosome, which gives some mechanistic insight into the effects of radiation damage on DNA, and (2) overcomes specific technical difficulties of assaying a human chromosome on a mouse background where highly conserved sequences may confound the analysis. Sequence data generated in this study is deposited in the ENA database, Study Accession number: ERP000439. PMID:23596509

  10. Technegas: A medical application of {sup 99m}Tc for the study of buckyballs, blood clots, lung disease and AIDS

    SciTech Connect

    Willett, G.D.; Dance, I.G.; Fisher, K.J. [Univ. of NSW, Sidney (Australia); Burch, W.M.; Dasaklis, C. [Australian National Univ., Canberra (Australia); Mackey, D.W.J. [Prince of Wales Hospital, Randwick (Australia)

    1994-12-31

    Radionuclide studies of lung disease have been greatly enhanced by the introduction of an Australian invention; the Technegas generator. The properties of the {open_quotes}dry radio-aerosols{close_quotes} produced by this device ensure lung images superior to those from true radio-gases such as {sup 133}Xe with the additional advantage of employing {sup 99m}Tc, the most widespread radionuclide agent. A Technegas lung scan can enable identification of pulmonary mebolism (an immediately life threatening condition) emphysema and chronic obstructive lung disease. A simple modification to the generator gas mixture produces Pertechnegas an agent useful in studies of the integrity of the alveolar epithelial membrane in immunosuppressed patients such as transplants and AIDS. Although these agents are now common in Australia and Europe, little has been proven of their chemical composites. Technegas is formed by the initial evaporation of ({sup 99m}Tc) sodium pertechnetate with the subsequent sublimation of carbon from a disposable graphite crucible at {approximately}2500{degrees}C in an atmosphere of 100% argon. {sup 99m}Tc atoms are lifted off with the crystalline layers of graphite during the vaporization. Technegas then possibly consists of {sup 99m}Tc based metallo-fullerenes and fullerenes. Technegas has an effective half life in the lung very similar to the physical half life of Technetium (6 hours) regardless of clinical condition; a result which suggests that Technegas contains endohedral fullerenes. Pertechnegas is created in an atmosphere of 97% Ar 3% O{sub 2} and has an effective half life in the lung of less than 15 minutes.

  11. The recovery of asteroid 2008 TC[subscript 3

    SciTech Connect

    Shaddad, Muawia H.; Jenniskens, Peter; Numan, Diyaa; Kudoda, Ayman M.; Elsir, Saadia; Riyad, Ihab F.; Ali, Awad Elkareem; Alameen, Mohammed; Alameen, Nada M.; Eid, Omer; Osman, Ahmed T.; AbuBaker, Mohamed I.; Yousif, Mohamed; Chesley, Steven R.; Chodas, Paul W.; Albers, Jim; Edwards, Wayne N.; Brown, Peter G.; Kuiper, Jacob; Friedrich, Jon M. (CIT); (Juba); (RNMI-Netherlands); (Khartoum); (UWO); (SETI); (Fordham)

    2011-09-06

    On October 7, 2008, asteroid 2008 TC{sub 3} impacted Earth and fragmented at 37 km altitude above the Nubian Desert in northern Sudan. The area surrounding the asteroid's approach path was searched, resulting in the first recovery of meteorites from an asteroid observed in space. This was also the first recovery of remains from a fragile 'cometary' PE = IIIa/b type fireball. In subsequent searches, over 600 mostly small 0.2-379 g meteorites (named 'Almahata Sitta') with a total mass 10.7 kg were recovered from a 30 x 7 km area. Meteorites fell along the track at 1.3 kg km{sup -1}, nearly independent of mass between 1 and 400 g, with a total fallen mass of 39 {+-} 6 kg. The strewn field was shifted nearly 1.8 km south from the calculated approach path. The influence of winds on the distribution of the meteorites, and on the motion of the dust train, is investigated. The majority of meteorites are ureilites with densities around 2.8 g cm{sup -3}, some of an anomalous (porous, high in carbon) polymict ureilite variety with densities as low as 1.5 g cm{sup -3}. In addition, an estimated 20-30% (in mass) of recovered meteorites were ordinary, enstatite, and carbonaceous chondrites. Their fresh look and matching distribution of fragments in the strewn field imply that they were part of 2008 TC{sub 3}. For that reason, they are all referred to as 'Almahata Sitta.' No ureilite meteorites were found that still held foreign clasts, suggesting that the asteroid's clasts were only loosely bound.

  12. Brain Single-photon Emission CT Studies Using 99mTc-HMPAO and 99mTc-ECD Early after Recanalization by Local Intraarterial Thrombolysis in Patients with Acute Embolic Middle Cerebral Artery Occlusion

    Microsoft Academic Search

    Kuniaki Ogasawara; Akira Ogawa; Masayuki Ezura; Hiromu Konno; Michiyasu Suzuki; Takashi Yoshimoto

    BACKGROUND AND PURPOSE: The brain distribution of 99mTc-hexamethylpropyleneam- ine oxime (HMPAO) correlates with regional brain perfusion, whereas 99mTc-ethyl cysteinate dimer (ECD) reflects not only perfusion but also the metabolic status of brain tissue. We compared 99mTc-ECD single-photon emission CT (SPECT) with 99mTc-HMPAO SPECT early after recanalization by local intraarterial thrombolysis (LIT) in patients with acute embolic middle cerebral artery occlusion.

  13. Relationship between SST in the equatorial Eastern Pacific and TC frequency that affects Korea

    NASA Astrophysics Data System (ADS)

    Choi, K. S.; Kim, B. J.

    2014-12-01

    This study analyzed that there was a strong negative correlation between sea surface temperature (SST) in the equatorial eastern Pacific and tropical cyclone (TC) frequency that affects Korea in summer season in 1951 to 2012. Then, 12 years that had the highest region-averaged SST values in the equatorial eastern Pacific (warm SST years) and 12 years that had the lowest SST values (cold SST years) were selected followed by analyzing average difference between two groups to identify any causes of possible correlation between SST in the equatorial eastern Pacific and TC frequency.In the warm SST years, not only TC frequency that affected Korea but also TC genesis frequency was low as well as TC intensity. A difference of 500 hPa and 850 hPa streamlines between two groups showed that anomalous northwesterlies were strengthened in Korea due to anomalous cyclonic circulations developed in the mid-latitude region in East Asia so that such anomalous steering flows played a role in preventing TCs from moving to Korea. Furthermore, anomalous anticyclonic circulations were strengthened in the east of Taiwan, which was related to weakening of the monsoon trough thereby causing lowering TC genesis frequency in the warm SST years. In addition, as anomalous cyclonic circulations were strengthened in the southeast quadrant of the tropical and subtropical western North Pacific, it created high TC genesis frequency in the sea in the warm SST years. Low TC frequency, low TC genesis frequency, and low TC intensity that affected Korea in the warm SST years were clearly seen by the analysis of differences between two groups with respect to 500 hPa and 850 hPa air temperature, 600 hPa relative humidity, precipitable water, 200-850 hPa vertical wind shear and sea surface temperature.

  14. Relationship between SST in the equatorial Eastern Pacific and TC frequency that affects Korea

    NASA Astrophysics Data System (ADS)

    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2014-07-01

    This study analyzed that there was a strong negative correlation between sea surface temperature (SST) in the equatorial Eastern Pacific and tropical cyclone (TC) frequency that affects Korea in summer season in 1951 to 2012. Then, 12 years that had the highest region-averaged SST values in the equatorial Eastern Pacific (warm SST years) and 12 years that had the lowest SST values (cold SST years) were selected, followed by analyzing average difference between two groups to identify any causes of possible correlation between SST in the equatorial Eastern Pacific and TC frequency. In the warm SST years, not only TC frequency that affected Korea but also TC genesis frequency was low, as well as TC intensity. A difference of 500 and 850 hPa streamlines between two groups showed that anomalous northwesterlies were strengthened in Korea due to anomalous cyclonic circulations developed in the mid-latitude region in East Asia, so that such anomalous steering flows played a role in preventing TCs from moving to Korea. Furthermore, anomalous anticyclonic circulations were strengthened in the east of Taiwan, which was related to weakening of the monsoon trough, thereby causing lowering TC genesis frequency in the warm SST years. In addition, as anomalous cyclonic circulations were strengthened in the southeast quadrant of the tropical and subtropical western North Pacific, it created high TC genesis frequency in the sea in the warm SST years. Low TC frequency, low TC genesis frequency, and low TC intensity that affected Korea in the warm SST years were clearly seen by the analysis of differences between two groups with respect to 500 and 850 hPa air temperature, 600 hPa relative humidity, precipitable water, 200-850 hPa vertical wind shear, and sea surface temperature.

  15. {sup 99m}Tc DTPA aerosol clearances in the assessment of radiation injury top the lung

    SciTech Connect

    Halkar, R.K.; Raghab, A.; Higazi, E. [Kuwait Univ. (Kuwait)] [and others

    1994-05-01

    In a prospective study, 36 patients with inoperable lung Ca. (sq. cells-24, adeno-5, largecell-2, unknown-5) underwent pre and post radiation {sup 99m}Tc DTPA aerosol clearance studies. The aim was to evaluate the value of aerosol clearance in the prediction of radiation injury to the regions other than the radiation field. Aerosol study was done using a commercially available nebulizer, dynamic images were obtained (30 sec/frame) in the posterior projection for a duration of 45 min. ROIs were drawn on upper, mid and lower zones on either lung, and time activity curves were generated. Using a linear fit, clearance half time (t{sub 1/2}) was calculated, for all six curves. The difference between pre and post radiation (t{sub 1/2}) was compared to the clinical follow up of each patient and a difference of more than 15 minutes was considered positive. Of the 36 patients 12 had a t{sub 1/2} difference of more than 15 minutes. Of these 5 patients had radiation pulmonlitis and the remaining 7 had respiratory failure due to infection and uremia. 24 patients had a t{sub 1/2} difference of less than 15 minutes and their clinical follow-up did not reveal any evidence of pulmonary radiation injury during this period. The results indicate that the clearance of Tc-99m DTPA aerosols is effective for excluding radiation pulmonlitis.

  16. Ascophyllan Purified from Ascophyllum nodosum Induces Th1 and Tc1 Immune Responses by Promoting Dendritic Cell Maturation

    PubMed Central

    Zhang, Wei; Du, Jiang-Yuan; Jiang, Zedong; Okimura, Takasi; Oda, Tatsuya; Yu, Qing; Jin, Jun-O

    2014-01-01

    Marine-derived sulfated polysaccharides have been shown to possess certain anti-virus, anti-tumor, anti-inflammatory and anti-coagulant activities. However, the in vivo immunomodulatory effects of marine-derived pure compounds have been less well characterized. In this study, we investigated the effect of ascophyllan, a sulfated polysaccharide purified from Ascophyllum nodosum, on the maturation of mouse dendritic cells (DCs) in vitro and in vivo. Ascophyllan induced up-regulation of co-stimulatory molecules and production of pro-inflammatory cytokines in bone marrow-derived DCs (BMDCs). Moreover, in vivo administration of ascophyllan promotes up-regulation of CD40, CD80, CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-? in spleen cDCs. Interestingly, ascophyllan induced a higher degree of co-stimulatory molecule up-regulation and pro-inflammatory cytokine production than fucoidan, a marine-derived polysaccharide with well-defined effect for promoting DC maturation. Ascophyllan also promoted the generation of IFN-?-producing Th1 and Tc1 cells in the presence of DCs in an IL-12-dependent manner. Finally, myeloid differentiation primary response 88 (MyD88) signaling pathway was essential for DC maturation induced by ascophyllan. Taken together, these results demonstrate that ascophyllan induces DC maturation, and consequently enhances Th1 and Tc1 responses in vivo. This knowledge could facilitate the development of novel therapeutic strategies to combat infectious diseases and cancer. PMID:25026264

  17. Sorption coefficients and molecular mechanisms of Pu, U, Np, Am and Tc to Fe (hydr)oxides: a review.

    PubMed

    Li, Dien; Kaplan, Daniel I

    2012-12-01

    Pu, U, Np, Am and Tc are among the major risk drivers at nuclear waste management facilities throughout the world. Furthermore, uranium mining and milling operations have generated an enormous legacy of radioactively contaminated soils and groundwater. The sorption process of radionulcides onto ubiquitous Fe (hydr)oxides (FHOs; hematite, magnetite, goethite and ferrihydrite) is one of the most vital geochemical processes controlling the transport and fate of radionuclides and nuclear wastes in the subsurface zones. Meanwhile, understanding molecular-level chemical speciation of radionuclides onto FHOs is crucial to model their behavior in subsurface environments, and to develop new technologies for nuclear waste treatment and long-term remediation strategies for contaminated soils and groundwater. This review article aims (1) to provide risk or performance assessment modelers with macroscopic distribution coefficient (K(d)) data of Pu, U, Np, Am and Tc onto FHOs under different conditions (pH, radionuclide concentration, solution ion strength, sorbent loading, partial pressure of CO(2) (P CO(2)), equilibrium time) pertinent to environmental and engineered systems, and (2) to provide a microscopic or molecular-level understanding of the chemical speciation and sorption processes of these radionuclides to FHOs. PMID:23141377

  18. Competitive Reduction of Pertechnetate (99TcO4?) by Dissimilatory Metal Reducing Bacteria and Biogenic Fe(II)

    SciTech Connect

    Plymale, Andrew E.; Fredrickson, Jim K.; Zachara, John M.; Dohnalkova, Alice; Heald, Steve M.; Moore, Dean A.; Kennedy, David W.; Marshall, Matthew J.; Wang, Chong M.; Resch, Charles T.; Nachimuthu, Ponnusamy

    2011-02-01

    The fate of pertechnetate (99Tc(VII)O4 -) during bioreduction was investigated in the presence of 2-line ferrihydrite (Fh) and various dissimilatory metal reducing bacteria (DMRB) (Geobacter, Anaeromyxobacter, Shewanella) in comparison with TcO4 - bioreduction in the absence of Fh. In the presence of Fh, Tc was present primarily as a fine-grained Tc(IV)/Fe precipitate that was distinct from the Tc(IV)O2 ·nH2O solids produced by direct biological Tc(VII) reduction. Aqueous Tc concentrations (<0.2 ?m) in the bioreduced Fh suspensions (1.7 to 3.2 × 10-9 mol L-1) were over 1 order of magnitude lower than when TcO4 - was biologically reduced in the absence of Fh (4.0 × 10-8 to 1.0 × 10-7 mol L-1). EXAFS analyses of the bioreduced Fh-Tc products were consistent with variable chain length Tc-O octahedra bonded to Fe-O octahedra associated with the surface of the residual or secondary Fe(III) oxide. In contrast, biogenic TcO2 ·nH2O had significantly more Tc-Tc second neighbors and a distinct long-range order consistent with small particle polymers of TcO2. In Fe-rich subsurface sediments, the reduction of Tc(VII) by Fe(II) may predominate over direct microbial pathways, potentially leading to lower concentrations of aqueous 99Tc(IV).

  19. Technetium bis(. mu. -oxo) dimers of 1,4,7-triazacyclononane-N,N prime N, double prime -triacetate (TCTA). Synthesis and characterization of (TCTA)Tc(. mu. -O) sub 2 Tc(TCTA) sup n- (n = 2,3) and the crystal structure of Ba sub 2 (TCTA)Tc(. mu. -O) sub 2 Tc(TCTA)(ClO sub 4 )ter dot 9H sub 2 O

    SciTech Connect

    Linder, K.E.; Dewan, J.C.; Davison, A. (Massachusetts Institute of Technology, Cambridge (USA))

    1989-10-04

    The mixed-valence technetium(III/IV) bis({mu}-oxo) dimer ((TCTA)Tc({mu}-O){sub 2}Tc(TCTA)){sup 3{minus}} (1; TCTA = 1,4,7-triazayclononane-N,N{prime},N{double prime}-triacetate) has been prepared as its sodium and barium salts. This complex undergoes a reversible on-electron oxidation with potassium persulfate to form ((TCTA)Tc({mu}-O){sub 2}Tc(TCTA)){sup 2{minus}} (2). Both complexes have been characterized by elemental analysis, infrared, UV/visible, and resonance Raman spectroscopy, and fast atom bombardment mass spectrometry. A crystal structure analysis of the Tc(III/IV) dimeter Ba{sub 2}((TCTA)Tc({mu}O){sub 2}Tc(TCTA))(ClO{sub 4}){center dot}9H{sub 2}O (1c) reveals that the two Tc atoms are linked by a planar Tc({mu}-O){sub 2}Tc ring. One TCTA ligand binds to each Tc through an N{sub 3}O donor set, and one of the acetate groups from each ligand bridges the two metal atoms. Resonance Raman spectra of complexes 1 and 2 were obtained by irradiation at 514.5 nm; strong bands assigned to the four-membered Tc({mu}-O){sub 2}Tc ring and the metal-metal multiple bond were seen. The aqueous electrochemistry of the compounds confirms that they are related by a reversible one-electron wave. The Tc(III/IV) dimer 1 represents the first fully characterized Tc-(amino carboxylate) complex in an oxidation state lower than +4. Evidence for the existence of other Tc(III/IV) bis({mu}-oxo) dimers of this type with amino carboxylate ligands such as EDTA and NTA is presented. 23 refs., 3 figs., 4 tabs.

  20. Accumulation and release of 99 Tc by a macrophyte of the Yenisei River ( Elodea canadensis ) in laboratory experiments

    Microsoft Academic Search

    A. Bolsunovsky; L. Bondareva

    2008-01-01

    The study addresses 99Tc accumulation and release by Elodea canadensis, one of the abundant species of submerged plants in the Yenisei River 99Tc in water samples of the “Elodea-Yenisei River water” model system and in the biomass fractions was measured using a liquid scintillatio analyzer. Experiments\\u000a on accumulation of 99Tc by Elodea showed that 99Tc activity concentration can reach 120±6

  1. Two crucial experimental tests of the resonating valence bond--Luttinger liquid interlayer tunneling theory of high- Tc superconductivity

    SciTech Connect

    Anderson, P.W. (Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ (USA))

    1990-08-01

    The resonating valence bond--Luttinger liquid theory for the high-{Tc} normal state permits some predictions about the effect of superconductivity on two measures of the one-particle Green's function: angle-resolved photoemission and tunneling for a high-{Tc}--insulator--high-{Tc} junction. These are compared to preliminary experimental data.

  2. Hydrogen Isotope Measurements of Organic Acids and Alcohols by Pyrolysis-GC-MS-TC-IRMS

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2011-01-01

    One possible process responsible for methane generation on Mars is abiotic formation by Fischer-Tropsch-type (FTT) synthesis during serpentinization reactions. Measurement of carbon and hydrogen isotopes of intermediary organic compounds can help constrain the origin of this methane by tracing the geochemical pathway during formation. Of particular interest within the context of this work is the isotopic composition of organic intermediaries produced on the surfaces of mineral catalysts (i.e. magnetite) during hydrothermal experiments, and the ability to make meaningful and reproducible hydrogen isotope measurements. Reported here are results of experiments to characterize the hydrogen isotope composition of low molecular weight organic acids and alcohols. The presence of these organic compounds has been suggested by others as intermeadiary products made during mineral surface catalyzed reactions. This work compliments our previous study characterizing the carbon isotope composition of similar low molecular weight intermediary organic compounds (Socki, et al, American Geophysical Union Fall meeting, Abstr. #V51B-2189, Dec., 2010). Our hydrogen isotope measurements utilize a unique analytical technique combining Pyrolysis-Gas Chromatograph-Mass Spectrometry-High Temperature Conversion-Isotope Ratio Mass Spectrometry (Py-GC-MS-TC-IRMS). Our technique is unique in that it carries a split of the pyrolyzed GC-separated product to a Thermo DSQ-II? quadrupole mass spectrometer as a means of making qualitative and semi-quantitative compositional measurements of separated organic compounds, therefore both chemical and isotopic measurements can be carried out simultaneously on the same sample.

  3. Effects of mutant Ran/TC4 proteins on cell cycle progression.

    PubMed Central

    Ren, M; Coutavas, E; D'Eustachio, P; Rush, M G

    1994-01-01

    Ran/TC4, a member of the RAS gene superfamily, encodes an abundant nuclear protein that binds and hydrolyzes GTP. Transient expression of a Ran/TC4 mutant protein deficient in GTP hydrolysis blocked DNA replication, suggesting a role for Ran/TC4 in the regulation of cell cycle progression. To test this possibility, we exploited an efficient transfection system, involving the introduction of cDNAs in the pMT2 vector into 293/Tag cells, to analyze phenotypes associated with mutant and wild-type Ran/TC4 expression. Expression of a Ran/TC4 mutant protein deficient in GTP hydrolysis inhibited proliferation of transfected cells by arresting them predominantly in the G2, but also in the G1, phase of the cell cycle. Deletion of an acidic carboxy-terminal hexapeptide from the Ran/TC4 mutant did not alter its nuclear localization but did block its inhibitory effect on cell cycle progression. These data suggest that normal progression of the cell cycle is coupled to the operation of a Ran/TC4 GTPase cycle. Mediators of this coupling are likely to include the nuclear regulator of chromosome condensation 1 protein and the mitosis-promoting factor complex. Images PMID:8196659

  4. Impact of Mobile-Immoble Water on the Transport of Technetium (Tc-99) in Unsaturated Sediments

    NASA Astrophysics Data System (ADS)

    Jansik, D. P.; Wellman, D. M.; Cordova, E.; Wildenschild, D.

    2010-12-01

    Technetium has been released to the environment through nuclear power production and nuclear fuel processing; as a result, further spreading of Tc-99 is a concern at DOE sites across the US. The current body of work conducted on Tc-99 has provided a wealth of information regarding the redox relationships, sorption, solubility, and stability of the mineral phases, however little work has been conducted on the physical transport of the highly soluble pertechnetate oxyanion, in the subsurface. Current conceptual models do not explain the presence and persistence of the anion in deep vadose zone environments such as the Hanford, WA site. As new in situ remediation technologies are developed and remediation continues; it is necessary to understand implications for Tc-99 transport and mobilization in unsaturated systems. Specifically, foam and gas phase remediation could potentially alter established flow regimes by changing moisture content, flow paths, and surface reactivity of sediments; therefore, it is imperative to understand fundamental transport properties of Tc-99 in the context of physical and chemical constraints. Using an Unsaturated Flow Apparatus (UFA) we have conducted a series of experiments to examine the impact of mobile-immobile domains on the transport of Tc-99. By varying sand/silt ratios and saturations we examined how changes in pore morphology and moisture content impact the transport of Tc-99 within our experimental system. Results demonstrating the impact of sediment texture, pore morphology and soil moisture content on Tc-99 transport will be presented.

  5. Demonstrating alcoholic cirrhosis of the liver by Tc-99m BIDA scintigram

    SciTech Connect

    Shih, W.J.; DeLand, F.H.; Domstad, P.A.

    1984-08-01

    Six patients with decompensated cirrhosis of the liver underwent Tc-99m BIDA studies. All demonstrated 1) persistently high blood pool activity in the heart, lung, and soft tissue, 2) slow hepatic tracer uptake, 3) prolonged liver-to-bowel transit time, and 4) visualization of an enlarged spleen. Four of the six patients demonstrated evidence of ascites and in one patient there were visible collateral veins of the abdomen. These findings are due primarily to hepatic dysfunction and retaining Tc-99m BIDA in blood pool because of Tc-99m BIDA exclusively hepatic excretion and little or no alternative renal excretion. All six Tc-99m sulfur colloid studies were performed concomitantly. Except for bone marrow uptake and reversal of the normal liver-spleen ratio of radioactivity, the imaging abnormalities observed with Tc-99m BIDA were similar to those seen by Tc-99m SC. It is concluded that with Tc-99m BIDA studies, three of six abnormal findings, as described, suggest a decompensated stage of cirrhosis of the liver.

  6. Theory of high-TC superconductivity: transition temperature

    NASA Astrophysics Data System (ADS)

    Harshman, Dale R.; Fiory, Anthony T.; Dow, John D.

    2010-12-01

    After reading over our published manuscript, we noticed that the discussion concerning the determination of ? for the ruthenate Ba2YRu0.9Cu0.1O6 in section 2.3.1 (3rd paragraph) is somewhat terse. Herein we provide an expanded analysis which better explains our estimate of ? (and thus ?) for this compound. All numbers, figures and conclusions remain unaltered. The ruthenate compounds A2YRu1-xCuxO6 (with A = Ba or Sr; x = 0.05-0.15) are double-perovskites containing no cuprate planes and with ? = ? = 1 [1] (reference [82] in the paper). The determination of ? follows from equation (2.5b), wherein rule 1b introduces the factor 1/2. In the lower limit, one expects a minimum of ~2 charges per Cu dopant, which are shared between two charge reservoirs of each layer type (AO and 1/2 (YRu1-xCuxO4)), producing a net factor of unity. Thus, for Ba2YRu0.9Cu0.1O6 (with TC0 ~ 30-40 K), we estimate ? = (1/2)(1) = 1/2, yielding ? = 0.05 as stated by equation (2.5c) in the paper. While one may expect an average effective charge state for Ru near +5, and that of Cu to be between +2 and +3 (post anneal) [2], the lower-limit estimation provided, which places the corresponding data point in figure 2 to the left of the line, appears sufficient to include the ruthenates with the other high-TC compounds found to follow equation (2.6) so far. Owing to the uncertainty in the experimental values for TC0, as well as the Ru and Cu valence states, however, this compound was excluded in the data analyses presented. Future research will attempt a more accurate determination of the charge per doped Cu, and thus ?. We would also like to point out a typographical correction in the definition of the corresponding ruthenate type II reservoir in the last column of table 1, which should read 1/2 (YRu0.9Cu0.1O4). An unrelated item is found in the fourth line of section 2.3.3, where Tb(O0.80F0.20)FeAs should read Tb(O0.80-yF0.20)FeAs. Additionally, reference [132] is now known and has the form: [132] Harshman D R and Fiory A T 2011 J. Phys.: Condens. Matter 23 315702 References [1] Parkinson N G, Hatton P D, Howard J A K, Ritter C, Chien F Z and Wu M-K 2003 J. Mater. Chem. 13 1468 [2] Rao S M, Wu M-K, Ren H C, Chen C L, Guo J-H, Hsu F C, Chen S Y, Chen Y Y, Chang C L and Liu H L 2011 in preparation

  7. 99mTc(CO)3(NTA): A 99mTc Renal Tracer with Pharmacokinetic Properties Comparable to Those of 131I-OIH in Healthy Volunteers

    PubMed Central

    Taylor, Andrew T.; Lipowska, Malgorzata; Marzilli, Luigi G.

    2010-01-01

    Objectives Studies in rats showed that the pharmacokinetics of the tricarbonyl core radiopharmaceutical 99mTc(CO)3-nitrilotriacetic acid, 99mTc(CO)3(NTA), were essentially identical to those of 131I ortho-iodohippuran (131I-OIH), the clinical gold standard for the measurement of effective renal plasma flow. Our objective was to compare the pharmacokinetics of these two tracers in healthy volunteers. Methods 99mTc(CO)3(NTA) was prepared with commercially available NTA and a commercially available IsoLink kit (Covidien) and isolated by reversed-phased high-performance liquid chromatography. Approximately 74 MBq (2.0 mCi) of 99mTc(CO)3(NTA) were coinjected with 9.25 MBq (250 ?Ci) of 131I-OIH in nine volunteers, and simultaneous imaging of each tracer was performed for 24 min. Plasma clearances were determined from 8 blood samples obtained 3–90 min after injection using the single-injection, two-compartment model. Plasma protein binding, red cell uptake, and percentage injected dose in the urine at 30 and 180 minutes were determined. Results There was no difference in the plasma clearances of 99mTc(CO)3(NTA) and 131I-OIH, 475 ± 105 mL/min versus 472 ± 108 mL/min, respectively. The plasma protein binding and red cell uptake of 99mTc(CO)3(NTA) were 43 ± 5% and 9 ± 6%, respectively; both values were significantly lower (P < 0.001) than the plasma protein binding (75 ± 3%) and red cell uptake (17 ± 5%) of 131I-OIH. There was no significant difference in the percent injected dose recovered in the urine at 30 min and at 3 h; for comparison, the percent dose in the urine at 3 h was 91 ± 4% for 99mTc(CO)3(NTA) and 91 ± 6% for 131I-OIH (P = 0.96). Image quality with 99mTc(CO)3(NTA) was excellent, and the renogram parameters were similar to those of 131I-OIH. Conclusions Preliminary results in healthy volunteers suggest that the pharmacokinetic behavior of 99mTc(CO)3(NTA) is comparable to that of 131I-OIH. PMID:20150248

  8. Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism

    PubMed Central

    Sager, Sait; Shafipour, Hojjat; Asa, Sertac; Y?lmaz, Sabire; Teksöz, Serkan; Önsel, Çetin

    2014-01-01

    Background: The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions. Materials and Methods: In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated. Results: Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results. Conclusion: As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images. PMID:25143912

  9. Infrared two-color multicycle laser field synthesis for generating an intense attosecond pulse.

    PubMed

    Takahashi, Eiji J; Lan, Pengfei; Mücke, Oliver D; Nabekawa, Yasuo; Midorikawa, Katsumi

    2010-06-11

    We propose and demonstrate the generation of a continuum high-order harmonic spectrum by mixing multicycle two-color (TC) laser fields with the aim of obtaining an intense isolated attosecond pulse. By optimizing the wavelength of a supplementary infrared pulse in a TC field, a continuum harmonic spectrum was created around the cutoff region without carrier-envelope phase stabilization. The obtained harmonic spectra clearly show the possibility of generating isolated attosecond pulses from a multicycle TC laser field, which is generated by an 800 nm, 30 fs pulse mixed with a 1300 nm, 40 fs pulse. Our proposed method enables us not only to relax the requirements for the pump pulse duration but also to reduce ionization of the harmonic medium. This concept opens the door to create an intense isolated attosecond pulse using a conventional femtosecond laser system. PMID:20867240

  10. Crystal and molecular structure of tetrameric technetium tricarbonyl iodide [Tc(CO)âI]â

    Microsoft Academic Search

    A. E. Miroslavov; G. V. Sidorenko

    1995-01-01

    The structure of (Tc(CO)âI)â has been studied by single-crystal X-ray diffraction. Crystal data: monoclinic, a =18.125(12), b= 9l741(6), c=16.577(9) â«, β = 118.50(4)°, V=2572(3) â«Â³, space group C2\\/c, Z=4, d{sub calc} = 3.191 g cm⁻³, μ(MoK{sub α}) = 67 cm⁻¹. The crystal structure consists of isolated tetrameric molecules (Tc(CO)âI)â having a cubane-like structure. The Tc(CO)â moieties are linked via bridging

  11. Etiology of amyloidosis determines myocardial 99mTc-DPD uptake in amyloidotic cardiomyopathy.

    PubMed

    Longhi, Simone; Bonfiglioli, Rachele; Obici, Laura; Gagliardi, Christian; Milandri, Agnese; Lorenzini, Massimiliano; Guidalotti, Pier Luigi; Merlini, Giampaolo; Rapezzi, Claudio

    2015-05-01

    Tc-DPD (Tc-3,3-diphosphono-1,2-propanodicarboxylic acid) has a high affinity for transthyretin (TTR)-infiltrated myocardium, allowing a differential diagnosis with light chain cardiac amyloidosis and other nonamyloidotic cardiomyopathies with a hypertrophic phenotype, in which myocardial tracer uptake is low or absent. Myocardial bone tracer uptake in the rarer forms of amyloidosis (eg, apolipoprotein-related) has been rarely studied. We present 4 cases of cardiac amyloidosis that underwent Tc-DPD scintigraphy; myocardial DPD uptake was present in patients with ATTR, wtTTR and apolipoprotein AI and negative in cases with AL and apolipoprotein AII-related disease. PMID:25742226

  12. Monoclonal antibodies (MAb) made against insect-derived metacyclic trypomastigotes (IMT) of Trypanosoma cruzi (TC) cross-react with other parasite forms

    SciTech Connect

    Kirchhoff, L.V.; Gilliam, F.C.

    1986-03-05

    Considerable information has been generated in recent years about stage-specific surface membrane antigens of a number of protozoa, and this phenomenon has been observed among several stages of TC as well. However, little is known about the surface antigens of IMT, the true infective stage of TC, because of the difficulty of obtaining sufficient numbers of these organisms for analysis. The Tulahuen strain of TC was maintained in the reduviid vector Dipetalogaster maximus by repeated feeding on mice with high parasitemias. IMT collected with insect urine were irradiated (150 krad) and used to immunize a BALB/c mouse for hybridoma production. Supernatants were screened by immunofluorescence assay for the presence of IgG MAb that react with methanol-fixed IMT, epimastogotes (EPI) and culture-derived metacyclic trypomastigoes (CMT). Of 41 MAb obtained, 40 reacted with IMT, 37 with EPI and 38 with CMT. Four MAb immunoprecipitated radioiodinated proteins or protein conjugates of M/sub r/ 80, 72, 45 and 45 from lysates of /sup 125/I surface-labeled EPI. These results indicate that, at least at the epitopic level, there is considerable overlap among IMT, EPI and CMT surface antigens. This finding suggests that analysis of surface proteins of the latter 2 parasite forms may lead to identification of molecules useful for vaccine development.

  13. Pharmacokinetic analysis of blood distribution of intravenously administered 153Gd-labeled Gd(DTPA)2- and 99mTc(DTPA) in rats.

    PubMed

    Wedeking, P; Eaton, S; Covell, D G; Nair, S; Tweedle, M F; Eckelman, W C

    1990-01-01

    Rat plasma distribution data obtained following IV administration of 99mTc(DTPA) alone or after co-administration of 99mTc(DTPA) and 153Gd-labeled Gd(DTPA)2- at 0.001, 0.1, and 1.0 mmol Gd/kg were evaluated using compartmental modeling techniques. A three-compartment open model was found to fit the data significantly better (P less than 0.01) than a two- or four-compartment open model. This model incorporates and links the plasma and urine data and includes a delay to account for the transit time through the kidneys/ureters. The two nonplasma compartments of the model were assumed to be related to rapidly and slowly equilibrating tissues. Tc(DTPA) and Gd(DTPA)2- had nearly identical pharmacokinetic profiles in plasma and the rate constants were essentially the same. No significant dose dependent pharmacokinetic differences were found for the range of Gd(DTPA)2- doses tested. Simulations of the proposed three-compartment model were used to generate concentration-time curves for each of the three compartments. PMID:2082126

  14. Thermoelectric Generators 1. Thermoelectric generator

    E-print Network

    Lee, Ho Sung

    1 Thermoelectric Generators HoSung Lee 1. Thermoelectric generator 1.1 Basic Equations In 1821 of a thermoelectric generator module, and (b) a p-type and n-type thermocouple. #12;3 Consider a steady-state one-dimensional thermoelectric generator module as shown in Figure 2a. The module consists of many p-type and n

  15. Forward scattering from phonons as a pathway to increasing Tc in quasi-two-dimensional unconventional superconductors

    NASA Astrophysics Data System (ADS)

    Johnston, Steven

    2015-03-01

    One of the primary goals of superconductivity research is engineering materials that become superconducting at high temperatures. To this end, I will examine forward scattering from phonons as a general means to increase Tc in unconventional superconductors. First I will introduce the mechanisms for generating electron-lattice interactions in quasi-two-dimensional correlated systems that are peaked in the forward scattering direction. Then I will present case studies comparing theory to angle-resolved photoemission spectroscopy data for the Bi-family of cuprate superconductors and the recently discovered FeSe monolayer in SrTiO3 substrates [2]. These studies demonstrate the general principle of using particular electron-phonon interactions for enhancing superconductivity in unconventional pairing channels.

  16. Fast Monte Carlo based joint iterative reconstruction for simultaneous {sup 99m}Tc/{sup 123}I SPECT imaging

    SciTech Connect

    Ouyang Jinsong; El Fakhri, Georges; Moore, Stephen C. [Department of Radiology, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts 02115 (United States)

    2007-08-15

    Simultaneous {sup 99m}Tc/{sup 123}I SPECT allows the assessment of two physiological functions under identical conditions. The separation of these radionuclides is difficult, however, because their energies are close. Most energy-window-based scatter correction methods do not fully model either physical factors or patient-specific activity and attenuation distributions. We have developed a fast Monte Carlo (MC) simulation-based multiple-radionuclide and multiple-energy joint ordered-subset expectation-maximization (JOSEM) iterative reconstruction algorithm, MC-JOSEM. MC-JOSEM simultaneously corrects for scatter and cross talk as well as detector response within the reconstruction algorithm. We evaluated MC-JOSEM for simultaneous brain profusion ({sup 99m}Tc-HMPAO) and neurotransmission ({sup 123}I-altropane) SPECT. MC simulations of {sup 99m}Tc and {sup 123}I studies were generated separately and then combined to mimic simultaneous {sup 99m}Tc/{sup 123}I SPECT. All the details of photon transport through the brain, the collimator, and detector, including Compton and coherent scatter, septal penetration, and backscatter from components behind the crystal, were modeled. We reconstructed images from simultaneous dual-radionuclide projections in three ways. First, we reconstructed the photopeak-energy-window projections (with an asymmetric energy window for {sup 123}I) using the standard ordered-subsets expectation-maximization algorithm (NSC-OSEM). Second, we used standard OSEM to reconstruct {sup 99m}Tc photopeak-energy-window projections, while including an estimate of scatter from a Compton-scatter energy window (SC-OSEM). Third, we jointly reconstructed both {sup 99m}Tc and {sup 123}I images using projection data associated with two photopeak energy windows and an intermediate-energy window using MC-JOSEM. For 15 iterations of reconstruction, the bias and standard deviation of {sup 99m}Tc activity estimates in several brain structures were calculated for NSC-OSEM, SC-OSEM, and MC-JOSEM, using images reconstructed from primary (unscattered) photons as a reference. Similar calculations were performed for {sup 123}I images for NSC-OSEM and MC-JOSEM. For {sup 123}I images, dopamine binding potential (BP) at equilibrium and its signal-to-noise ratio (SNR) were also calculated. Our results demonstrate that MC-JOSEM performs better than NSC- and SC-OSEM for quantitation tasks. After 15 iterations of reconstruction, the relative bias of {sup 99m}Tc activity estimates in the thalamus, striata, white matter, and gray matter volumes from MC-JOSEM ranged from -2.4% to 1.2%, while the same estimates for NSC-OSEM (SC-OSEM) ranged from 20.8% to 103.6% (7.2% to 41.9%). Similarly, the relative bias of {sup 123}I activity estimates from 15 iterations of MC-JOSEM in the striata and background ranged from -1.4% to 2.9%, while the same estimates for NSC-OSEM ranged from 1.6% to 10.0%. The relative standard deviation of {sup 99m}Tc activity estimates from MC-JOSEM ranged from 1.1% to 4.8% versus 1.2% to 6.7% (1.2% to 5.9%) for NSC-OSEM (SC-OSEM). The relative standard deviation of {sup 123}I activity estimates using MC-JOSEM ranged from 1.1% to 1.9% versus 1.5% to 2.7% for NSC-OSEM. Using the {sup 123}I dopamine BP obtained from the reconstruction produced by primary photons as a reference, the result for MC-JOSEM was 50.5% closer to the reference than that of NSC-OSEM after 15 iterations. The SNR for dopamine BP was 23.6 for MC-JOSEM as compared to 18.3 for NSC-OSEM.

  17. Simulations of high-Tc superconductors using the DCA+ algorithm

    NASA Astrophysics Data System (ADS)

    Staar, Peter

    2015-03-01

    For over three decades, the high Tc-cuprates have been a gigantic challenge for condensed matter theory. Even the simplest representation of these materials, i.e. the single band Hubbard model, is hard to solve quantitatively and its phase-diagram is therefore elusive. In this talk, we present the recent algorithmic and implementation advances to the Dynamical Cluster Approximation (DCA). The algorithmic advances allow us to determine self-consistently a continuous self-energy in momentum space, which in turn reduces the cluster-shape dependency of the superconducting transition temperature and thus accelerates the convergence of the latter versus cluster-size. Furthermore, the introduction of the smooth self-energy suppresses artificial correlations and thus reduces the fermionic sign-problem, allowing us to simulate larger clusters at much lower temperatures. By combining these algorithmic improvements with a very efficient GPU accelerated QMC-solver, we are now able to determine the superconducting transition temperature accurately and show that the Cooper-pairs have indeed a d-wave structure, as was predicted by Zhang and Rice.

  18. GM=tc^3 Cosmology and the Moon

    NASA Astrophysics Data System (ADS)

    Riofrio, Louise

    2010-10-01

    Relativity suggests an expanding cosmology of scale R = ct, where t is age of the Universe. Gravitation would then require that c be further related to t by: GM = tc^3. Where G and M are mass and gravitational constant, this simple expression predicts data from the microwave background, including 4.507034% baryonic matter and a stable density ?= 1 . The non-linear increase in Type 1a supernova redshifts may be precisely predicted without repulsive energies. (Riofrio, 2004) Prediction of a changing c may be tested with modern lanterns and the distant hilltop of the Moon. Our Lunar Laser Ranging Experiment has measured the Moon's semimajor axis increasing at 3.82 ± .07 cm/yr, anomalously high. The Mansfield sediment (Bills, Ray 2000) measures lunar recession at 2.9 ± 0.6 cm/yr. More recent work accurately measures a recession rate of 2.88 ± 0.05 cm/yr. LLRE differs from independent experiments by 10 ?. If the speed of laser light were decaying, the Moon's apparent distance is predicted to increase by 0.935 cm/yr. An anomaly in the Moon's orbit is precisely accounted for. This interesting result may have importance for cosmology, shedding light on puzzles of ``dark energy.'' In Planck units, this may be summarised as: M = R = t.

  19. Substrates for microwave applications of high Tc superconductors

    SciTech Connect

    Bhalla, A.S.; Guo, R. [Pennsylvania State Univ., University Park, PA (United States)

    1996-12-31

    Systematic studies on low {kappa} oxide substrate materials suitable for epitaxial deposition of high Tc superconducting (HTSC) yttrium barium cuprate (YBCO) films and their microwave applications have been carried out. Several promising new hosts such as Sr(Al{sub 1/2}Ta{sub {1/2}})O{sub 3}, Sr(Al{sub {1/2}}Nb{sub {1/2}})O{sub 3}, and Ba(Mg{sub 1/3}Ta{sub 2/3})O{sub 3} in complex oxide perovskite family have been developed. The crystals of these compositions and their associated solid solutions with LaAlO{sub 3} and NdGaO{sub 3} provide new options for twin free, ultra low loss, low permittivity substrates with close structural and thermal properties matching to the YBCO. The unique capabilities of a laser heated pedestal growth (LBPG) system have been utilized for test-growth of candidate materials in single crystal fiber form to determine structure, thermal, and dielectric properties and to make positive identification of twin free systems.

  20. Charge segregation model for superconducting correlations in cuprates above Tc

    NASA Astrophysics Data System (ADS)

    de Mello, E. V. L.; Sonier, J. E.

    2014-12-01

    We present a theoretical framework for understanding recent transverse field muon spin rotation (TF-µSR) experiments on cuprate superconductors in terms of localized regions of phase-coherent pairing correlations above the bulk superconducting transition temperature Tc. The local regions of phase coherence are associated with a tendency toward charge ordering, a phenomenon found recently in hole-doped cuprates. We use the Cahn–Hilliard equation as a means to phenomenologically model the inhomogeneous charge distribution of the electron system observed experimentally. For this system we perform self-consistent superconducting calculations using the Bogoliubov–deGennes method. Within this context we explore two possible scenarios: (i) the magnetic field is diamagnetically screened by the sum of varying shielding currents of isolated small-sized superconducting domains. (ii) These domains become increasingly correlated by Josephson coupling as the temperature is lowered and the main response to the applied magnetic field is from the sum of all varying tunneling currents. The results indicate that these two approaches may be used to simulate the TF-µSR data but case (ii) yields better agreement.

  1. ??mTc pyrene derivative complex causes double-strand breaks in dsDNA mainly through cluster-mediated indirect effect in aqueous solution.

    PubMed

    Chung, Wei-Ju; Cui, Yujia; Huang, Feng-Yun J; Tu, Tzu-Hui; Yang, Tzu-Sen; Lo, Jem-Mau; Chiang, Chi-Shiun; Hsu, Ian C

    2014-01-01

    Radiation therapy for cancer patients works by ionizing damage to nuclear DNA, primarily by creating double-strand breaks (DSB). A major shortcoming of traditional radiation therapy is the set of side effect associated with its long-range interaction with nearby tissues. Low-energy Auger electrons have the advantage of an extremely short effective range, minimizing damage to healthy tissue. Consequently, the isotope ??mTc, an Auger electron source, is currently being studied for its beneficial potential in cancer treatment. We examined the dose effect of a pyrene derivative ??mTc complex on plasmid DNA by using gel electrophoresis in both aqueous and methanol solutions. In aqueous solutions, the average yield per decay for double-strand breaks is 0.011±0.005 at low dose range, decreasing to 0.0005±0.0003 in the presence of 1 M dimethyl sulfoxide (DMSO). The apparent yield per decay for single-strand breaks (SSB) is 0.04±0.02, decreasing to approximately a fifth with 1 M DMSO. In methanol, the average yield per decay of DSB is 0.54±0.06 and drops to undetectable levels in 2 M DMSO. The SSB yield per decay is 7.2±0.2, changing to 0.4±0.2 in the presence of 2 M DMSO. The 95% decrease in the yield of DSB in DMSO indicates that the main mechanism for DSB formation is through indirect effect, possibly by cooperative binding or clustering of intercalators. In the presence of non-radioactive ligands at a near saturation concentration, where radioactive Tc compounds do not form large clusters, the yield of SSB stays the same while the yield of DSB decreases to the value in DMSO. DSBs generated by ??mTc conjugated to intercalators are primarily caused by indirect effects through clustering. PMID:25244160

  2. 99mTc Pyrene Derivative Complex Causes Double-Strand Breaks in dsDNA Mainly through Cluster-Mediated Indirect Effect in Aqueous Solution

    PubMed Central

    Chung, Wei-Ju; Cui, Yujia; Huang, Feng-Yun J.; Tu, Tzu-Hui; Yang, Tzu-Sen; Lo, Jem-Mau; Chiang, Chi-Shiun; Hsu, Ian C.

    2014-01-01

    Radiation therapy for cancer patients works by ionizing damage to nuclear DNA, primarily by creating double-strand breaks (DSB). A major shortcoming of traditional radiation therapy is the set of side effect associated with its long-range interaction with nearby tissues. Low-energy Auger electrons have the advantage of an extremely short effective range, minimizing damage to healthy tissue. Consequently, the isotope 99mTc, an Auger electron source, is currently being studied for its beneficial potential in cancer treatment. We examined the dose effect of a pyrene derivative 99mTc complex on plasmid DNA by using gel electrophoresis in both aqueous and methanol solutions. In aqueous solutions, the average yield per decay for double-strand breaks is 0.011±0.005 at low dose range, decreasing to 0.0005±0.0003 in the presence of 1 M dimethyl sulfoxide (DMSO). The apparent yield per decay for single-strand breaks (SSB) is 0.04±0.02, decreasing to approximately a fifth with 1 M DMSO. In methanol, the average yield per decay of DSB is 0.54±0.06 and drops to undetectable levels in 2 M DMSO. The SSB yield per decay is 7.2±0.2, changing to 0.4±0.2 in the presence of 2 M DMSO. The 95% decrease in the yield of DSB in DMSO indicates that the main mechanism for DSB formation is through indirect effect, possibly by cooperative binding or clustering of intercalators. In the presence of non-radioactive ligands at a near saturation concentration, where radioactive Tc compounds do not form large clusters, the yield of SSB stays the same while the yield of DSB decreases to the value in DMSO. DSBs generated by 99mTc conjugated to intercalators are primarily caused by indirect effects through clustering. PMID:25244160

  3. Bioreduction of Fe-bearing clay minerals and their reactivity toward pertechnetate (Tc-99)

    SciTech Connect

    Bishop, Michael E.; Dong, Hailiang; Kukkadapu, Ravi K.; Liu, Chongxuan; Edelmann, Richard E.

    2011-07-01

    99Technetium (99Tc) is a fission product of uranium-235 and plutonium-239 and poses a high environmental hazard due to its long half-life (t1/2 = 2.13 x 105 y), abundance in nuclear wastes, and environmental mobility under oxidizing conditions [i.e., Tc(VII)]. Under reducing conditions, Tc(VII) can be reduced to insoluble Tc(IV). Ferrous iron [Fe(II)], either in aqueous form or in mineral form, has been used to reduce Tc(VII) to Tc(IV). However, the reactivity of Fe(II) from clay minerals, other than nontronite, toward immobilization of Tc(VII) and its role in retention of reduced Tc(IV) have not been investigated. In this study the reactivity of a suite of clay minerals toward Tc(VII) reduction and immobilization was evaluated. The clay minerals chosen for this study included five members in the smectite-illite (S-I) series, (montmorillonite, nontronite, rectorite, mixed layered I-S, and illite), chlorite, and palygorskite. Fe-oxides were removed from these minerals with a modified dithionite-citrate-bicarbonate (DCB) procedure. The total Fe content of these clay minerals, after Fe-oxide removal, ranged from 0.7 to 30.4% by weight, and the Fe(III)/Fe(total) ratio ranged from 44.9 to 98.5%. X-ray diffraction (XRD) and Mössbauer spectroscopy results showed that after Fe oxide removal the clay minerals were free of Fe-oxides. Scanning electron microscopy (SEM) revealed that little dissolution occurred during the DCB treatment. Bioreduction experiments were performed in bicarbonate buffer (pH-7) with Fe(III) in the clay minerals as the sole electron acceptor, lactate as the sole electron donor, and Shewanella Putrifaciens CN32 cells as mediators. In select tubes, anthraquinone-2,6-disulfate (AQDS) was added as electron shuttle to facilitate electron transfer. The extent of Fe(III) bioreduction was the highest for chlorite (~43 wt%) and the lowest for palygorskite (~4.17 wt%). In the S-I series, NAu-2 was the most reducible (~31 %) and illite the least (~0.4 %). The extent and initial rate of bioreduction were positively correlated with the percent smectite in the S-I series (i.e., layer expandability). Fe(II) in the bioreduced clay minerals subsequently was used to reduce Tc(VII) to Tc(IV) in PIPES buffer. Similar to the trend of bioreduction, in the S-I series, reduced smectite showed the highest reactivity toward Tc(VII), and reduced illite exhibited the least. The initial rate of Tc(VII) reduction, after normalization to clay and Fe(II) concentrations, was positively correlated with the percent smectite in the S-I series. Fe(II) in chlorite and palygorskite was also reactive toward Tc(VII) reduction. These data demonstrate that crystal chemical parameters (layer expandability, Fe and Fe(II) contents, and surface area etc.) play important roles in controlling the extent and rate of bioreduction and the reactivity toward Tc(VII) reduction. Reduced Tc(IV) resides within clay mineral matrix, and this association could minimize any potential of reoxidation over long term.

  4. Ocean-wave coupled modeling in COAMPS-TC: A study of Hurricane Ivan (2004)

    NASA Astrophysics Data System (ADS)

    Smith, Travis A.; Chen, Sue; Campbell, Timothy; Martin, Paul; Rogers, W. Erick; Gaberšek, Saša; Wang, David; Carroll, Suzanne; Allard, Richard

    2013-09-01

    Tropical cyclone ocean-wave model interactions are examined using an ESMF - (Earth System Modeling Framework) based tropical cyclone (TC) version of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®

  5. Influence of pair breaking and phase fluctuations on disordered high Tc cuprate superconductors.

    PubMed

    Rullier-Albenque, F; Alloul, H; Tourbot, R

    2003-07-25

    Electron irradiation has been used to introduce point defects in a controlled way in underdoped and optimally doped YBa(2)Cu(3)O(7-delta) crystals. This technique allows us to perform very accurate measurements of T(c) and of the ab plane resistivity in a wide range of defect contents x(d) down to T(c)=0. The variation of T(c) and of the transition width with x(d) do not follow current predictions of pair-breaking theories. The data are rather compatible, at least for the highly damaged regime, with the expected influence of phase fluctuations. These results open new questions about the evolution of the defect induced T(c) depression over the phase diagram of the cuprates. PMID:12906689

  6. Aerosol characteristics of 99mTc-pentetic acid (DTPA) and synthetic surfactant (Exosurf).

    PubMed

    Coleman, R E; MacIntyre, N; Snyder, G; Pattishall, E; Zaccardelli, D

    1994-06-01

    This study evaluated the feasibility of using 99mTc-pentetic acid (DTPA) as a radioactive tracer for aerosolized synthetic surfactant (DPPC, cetyl alcohol, tyloxapol). The 99mTc-DTPA was admixed with surfactant and aerosolized using a nebulizer system interfaced to a ventilator with a cascade impactor attached to the endotracheal tube. Particle size distribution for DPPC, cetyl alcohol, and 99mTc-DTPA were almost identical during the 0- to 15-, 15- to 30-, and 0- to 30-min collection periods. Tyloxapol exhibited a unique distribution pattern with increased deposition in large (> 10 microns) and small (0.65 to 1.1 microns) particles. The mass median aerodynamic diameter for all aerosolized components was in the respirable range of 2.1 to 2.5 microns. A mixture of 99mTc-DTPA with synthetic surfactant appears to be a reasonable method to evaluate surfactant deposition. PMID:8205874

  7. The Ideal Liquid Discovered by RHIC, Infrared Slavery Above and Hadronic Freedom Below $T_c$

    E-print Network

    Gerald E. Brown; Chang-Hwan Lee; Mannque Rho

    2005-07-05

    We construct the nature of the matter found in RHIC when its temperature has dropped down close to, and below, $T_c$. Just above $T_c$ it is composed of extremely strongly bound quark-antiquark pairs forming chirally restored mesons of the quantum numbers of the $\\pi, S, \\rho$ and $a_1$ with very small size and zero energy and just below $T_c$, it is composed of mesons of the same quantum numbers with zero mass. We invoke infrared slavery for the former and the vector manifestation (VM) of hidden local symmetry for the latter. As the temperature drops below $T_c$, the strongly bound quark-antiquark pairs are ejected into what is basically a region of "hadronic freedom" in which the interactions are zero. Experimental evidences for this are seen in the STAR data.

  8. The Ideal Liquid Discovered by RHIC, Infrared Slavery Above and Hadronic Freedom Below $T_c$

    E-print Network

    Brown, G E; Rho, M; Brown, Gerald E.; Lee, Chang-Hwan; Rho, Mannque

    2005-01-01

    We construct the nature of the matter found in RHIC when its temperature has dropped down close to, and below, $T_c$. Just above $T_c$ it is composed of extremely strongly bound quark-antiquark pairs forming chirally restored mesons of the quantum numbers of the $\\pi, S, \\rho$ and $a_1$ with very small size and zero energy and just below $T_c$, it is composed of mesons of the same quantum numbers with zero mass. We invoke infrared slavery for the former and the vector manifestation (VM) of hidden local symmetry for the latter. As the temperature drops below $T_c$, the strongly bound quark-antiquark pairs are ejected into what is basically a region of "hadronic freedom" in which the interactions are zero. Experimental evidences for this are seen in the STAR data.

  9. High temperature magnetic ordering in the 4d perovskite SrTcO3

    SciTech Connect

    Rodriguez, Efrain E. [National Institute of Standards and Technology (NIST), Gaithersburg, MD; Poineau, Frederic [University of Nevada, Las Vegas; Llobet, Anna [Los Alamos National Laboratory (LANL); Kennedy, Brendan J. [University of Technology Sydney; Avdeev, Maxim [Bragg Institute, ANSTO; Thorogood, Gordon J. [Bragg Institute, ANSTO; Carter, Melody L. [ANSTO; Seshadri, Ram [University of California, Santa Barbara; Singh, David J [ORNL; Cheetham, Anthony K. [University of Cambridge

    2011-01-01

    We present evidence for possibly the highest magnetic ordering temperature in any compound without 3d transition elements. Neutron powder diffraction measurements, at both time-of-flight and constant wavelength sources, were performed on two independently prepared SrTcO{sub 3} powders. SrTcO{sub 3} adopts a distorted perovskite structure with G-type antiferromagnetic ordering and has a moment of 1.87(4){mu}{sub B} per Tc cation at room temperature with an extraordinarily high Neel point close to 750 C. Electronic structure calculations reveal extensive mixing between the technetium 4d states and oxygen states proximal to the Fermi level. This hybridization leads to a close relationship between magnetic ordering temperature and moment formation in SrTcO{sub 3}.

  10. Excited states of 102Tc: A study of the proton-neutron interaction

    NASA Astrophysics Data System (ADS)

    de Gelder, P.; de Frenne, D.; Jacobs, E.; Heyde, K.; Fortier, S.; Maison, J. M.; Rao, M. N.; Massolo, C. P.

    1982-01-01

    Levels in 102Tc up to an excitation energy of 1 MeV were studied by means of the 100Mo(3He,p)102Tc and 104Ru(d,?)102Tc reactions at incident energies of 25 and 20 MeV, respectively. Tentative spin assignments were deduced from distorted-wave Born approximation analyses of the proton angular distributions. The results are discussed in the framework of the shell model. NUCLEAR REACTIONS 100Mo(3He,p), E3He=25 MeV; measured ?(Ep,?), ?=5°-40°. 104Ru(d,?), Ed=20 MeV; measured E? at ?=15°. Enriched targets. Split-pole spectrograph. 102Tc deduced levels, tentative Lnp,J?. DWBA analysis. Calculated: ?1g92?1g72 proton-neutron multiplet structure.

  11. TcSNP: a database of genetic variation in Trypanosoma cruzi

    PubMed Central

    Ackermann, Alejandro A.; Carmona, Santiago J.; Agüero, Fernán

    2009-01-01

    The TcSNP database (http://snps.tcruzi.org) integrates information on genetic variation (polymorphisms and mutations) for different stocks, strains and isolates of Trypanosoma cruzi, the causative agent of Chagas disease. The database incorporates sequences (genes from the T. cruzi reference genome, mRNAs, ESTs and genomic sequences); multiple sequence alignments obtained from these sequences; and single-nucleotide polymorphisms and small indels identified by scanning these multiple sequence alignments. Information in TcSNP can be readily interrogated to arrive at gene sets, or SNP sets of interest based on a number of attributes. Sequence similarity searches using BLAST are also supported. This first release of TcSNP contains nearly 170 000 high-confidence candidate SNPs, derived from the analysis of annotated coding sequences. As new sequence data become available, TcSNP will incorporate these data, mapping new candidate SNPs onto the reference genome sequences. PMID:18974180

  12. Identification of the non-pertechnetate species in Hanford waste tanks, Tc(I) carbonyl complexes

    SciTech Connect

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

    2003-10-16

    Immobilization of the high-level nuclear waste stored at the Hanford Reservation has been complicated by the presence of soluble, lower-valent technetium species. Previous work by Schroeder and Blanchard has shown that these species cannot be removed by ion-exchange and are difficult to oxidize. The Tc-K edge XANES spectra of the species in Tanks SY-101 and SY-103 were reported by Blanchard, but they could not be assigned to any known technetium complex. We report that the XANES spectra are most likely those of Tc(I) carbonyl species, especially fac-Tc(CO){sub 3}(gluconate){sup 2-}. This is further supported by EXAFS and {sup 99}Tc-NMR studies in nonradioactive simulants of these tank wastes.

  13. Involvement of phosphatidylinositol 3-kinase, but not RalGDS, in TC21/R-Ras2-mediated transformation.

    PubMed

    Murphy, Gretchen A; Graham, Suzanne M; Morita, Staeci; Reks, Sarah E; Rogers-Graham, Kelley; Vojtek, Anne; Kelley, Grant G; Der, Channing J

    2002-03-22

    Oncogenic Ras and activated forms of the Ras-related protein TC21/R-Ras2 share similar abilities to alter cell proliferation. However, in contrast to Ras, we found previously that TC21 fails to activate the Raf-1 serine/threonine kinase. Thus, TC21 must utilize non-Raf effectors to regulate cell function. In this study, we determined that TC21 interacts strongly with some (RalGDS, RGL, RGL2/Rlf, AF6, and the phosphatidylinositol 3-kinase (PI3K) catalytic subunit p110delta), and weakly with other Ras small middle dotGTP-binding proteins. In addition, library screening identified novel TC21-interacting proteins. We also determined that TC21, similar to Ras, mediates activation of phospholipase Cepsilon. We then examined if RalGDS, a RalA guanine nucleotide exchange factor, or PI3K are effectors for TC21-mediated signaling and cell proliferation in murine fibroblasts. We found that overexpression of full-length RalGDS reduced the focus forming activity of activated TC21. Furthermore, expression of activated Ras, but not TC21, enhanced GTP loading on RalA. In fact, TC21 attenuated insulin-stimulated RalA small middle dotGTP formation. In contrast, like Ras, expression of activated TC21 resulted in membrane translocation and an increase in the PI3K-dependent phosphorylation of Akt, and inhibition of PI3K activity interfered with TC21 focus formation. Finally, unlike Ras, TC21 did not activate the Rac small GTPase, indicating that Ras may not activate Rac by PI3K. Taken together, these results suggest that PI3K, but not RalGDS, is an important mediator of cell proliferation by TC21. PMID:11788587

  14. Ibogaine labeling with 99mTc-tricarbonyl: synthesis and transport at the mouse blood-brain barrier.

    PubMed

    Tournier, Nicolas; André, Pascal; Blondeel, Sandy; Rizzo-Padoin, Nathalie; du Moulinet d'Hardemarre, Amaury; Declèves, Xavier; Scherrmann, Jean-Michel; Cisternino, Salvatore

    2009-12-01

    The (99m)Tc-tricarbonyl core may be used as an ideal tool for gamma-labeling ligands in noninvasive SPECT imaging. However, most (99m)Tc-tricarbonyl-labeled agents have difficulty crossing the blood-brain barrier (BBB). We radiolabeled the neuroactive indole ibogaine with (99m)Tc-tricarbonyl and measured its transport into the mouse brain by in situ brain perfusion. We measured the interactions of [(99m)Tc(CO)(3)-ibogaine](+) and (99m)Tc-tricarbonyl with the main BBB efflux transporters P-gp and BCRP in vitro and in vivo. Ibogaine was radiolabeled (yield: over 95%). [(99m)Tc(CO)(3)-ibogaine](+) entered the brain (K(in)) poorly (0.18 microL/g/s), at about the same rate as (99m)Tc-tricarbonyl (0.16 microL/g/s) and [(99m)Tc-sestamibi](+) (0.10 microL/g/s). The CNS tracer [(99m)Tc-HMPAO](0) entered the brain approximately 70-times higher than [(99m)Tc(CO)(3)-ibogaine](+). In vitro studies revealed that neither [(99m)Tc(CO)(3)-ibogaine](+) nor (99m)Tc-tricarbonyl ion were substrates for P-gp or BCRP. But lowering the membrane dipole potential barrier with phloretin enhanced the brain transport of [(99m)Tc(OH(2))(3)(CO)(3)](+) approximately 3-fold. Thus, ibogaine directly labeled with (99m)Tc-tricarbonyl is not suitable for CNS imaging because of its poor uptake. Brain transport is not restricted by efflux transporters but is reduced by its lipophilicity and interaction with the membrane-positive dipole potential. PMID:19492342

  15. Chart Generation

    Microsoft Academic Search

    Martin Kay

    1996-01-01

    Charts constitute a natural uniform architecture for parsing and generation provided string position is replaced by a notion more appropriate to logical forms and that measures are taken to curtail generation paths containing semantically incomplete phrases.

  16. Tc 1Like Transposable Elements in the Genome of Lake Trout ( Salvelinus namaycush )

    Microsoft Academic Search

    Kent M. Reed

    1999-01-01

    .   This study reports on the DNA sequence of a Tc1-like transposable element Tsn1 from lake trout (Salvelinus namaycush). Tc1-like elements were amplified by PCR using an oligonucleotide primer based on the Tdr1 element of zebrafish. One full-length and two partial-length copies of the transposon were sequenced. In addition, partial\\u000a Tsn1 elements were recovered from PCR reactions run with primers

  17. Forensic validation of the STR systems SE 33 and TC 11

    Microsoft Academic Search

    P. Wiegand; B. Budowle; S. Rand; B. Brinkmann

    1993-01-01

    Summary Population studies on Caucasians from northwest Germany were carried out using the short tandem repeat (STR) systems SE 33 (Locus: ACTBP2) and TC 11 (Locus: 11p15.5). After electrophoresis in PAG 26 alleles could be identified for SE 33 in a sample size of 180 unrelated individuals and 6 alleles were found for TC 11 in 110 individuals. The combined

  18. Differential concentration of Technetium99 ( 99Tc) in common intertidal molluscs with different food habits

    Microsoft Academic Search

    K. Sjøtun; H. E. Heldal; D. S. Brakstad

    2011-01-01

    Concentration of 99Tc has been measured in fucoids and molluscs, sampled in a sheltered intertidal at the southwest coast of Norway from February to November 2006. The concentrations of 99Tc in molluscs differed significantly between species. The filtering bivalve Mytilus edulis had the lowest concentrations with averages of 2.3–5.9Bqkg?1d.w., while the herbivorous gastropods Littorinalittorina, Littorina obtusata and Patella vulgata had

  19. /sup 99m/Tc-fibrinogen scanning in adult respiratory distress syndrome

    SciTech Connect

    Quinn, D.A.; Carvalho, A.C.; Geller, E.; Khaw, B.A.; Barlaikovach, M.; Zielonka, J.; Greene, R.; Strauss, H.W.; Zapol, W.M.

    1987-01-01

    Fibrin is often seen occluding the lung vessels of patients dying from ARDS and is surrounded by regions of lung necrosis. To learn if we could observe increased or focal fibrin deposition and assess the kinetics of plasma fibrinogen turnover during severe acute respiratory failure, we injected technetium 99m-labeled human purified fibrinogen (Tc-HF) and used gamma camera scanning for as long as 12 h in 13 sequential patients as soon as possible after ICU admission. The fibrinogen uptake rates were determined by calculating the lung:heart radioactivity ratios at each time point. Slopes of the lung:heart ratio versus time were compared between ARDS and mild acute respiratory failure (ARF). The slope of the lung:heart Tc-HF ratio of the 9 patients with ARDS (2.9 +/- 0.4 units) was markedly higher (p less than 0.02) than the slope of the 4 patients with mild ARF (1.1 +/- 0.4) and the 3 patients studied 5 to 9 months after recovery from respiratory failure (0.7 +/- 0.07). In the 1 patient with ARDS and the 2 patients with mild ARF studied both during acute lung injury and after recovery, the lung:heart Tc-HF ratio had decreased at recovery. To compare the pulmonary uptake of Tc-HF to /sup 99m/Tc-labeled human serum albumin (Tc-HSA), 5 patients were injected with 10 mCi of Tc-HSA, and scanning of the thorax was performed with a similar sequential imaging protocol 24 h after conclusion of the Tc-HF study.

  20. TcVac3 induced control of Trypanosoma cruzi infection and chronic myocarditis in mice.

    PubMed

    Gupta, Shivali; Garg, Nisha Jain

    2013-01-01

    We characterized the immune responses elicited by a DNA-prime/MVA-boost vaccine (TcVac3) constituted of antigenic candidates (TcG2 and TcG4), shown to be recognized by B and T cell responses in Trypanosoma cruzi (Tc) infected multiple hosts. C57BL/6 mice immunized with TcVac3 elicited a strong antigen-specific, high-avidity, trypanolytic antibody response (IgG2b>IgG1); and a robust antigen- and Tc-specific CD8(+)T cell response with type-1 cytokine (IFN-?(+)TNF-?>IL-4(+)IL-10) and cytolytic effector (CD8(+)CD107a(+)IFN-?(+)Perforin(+)) phenotype. The vaccine-induced effector T cells significantly expanded upon challenge infection and provided >92% control of T. cruzi. Co-delivery of IL-12 and GMCSF cytokine adjuvants didn't enhance the TcVac3-induced resistance to T. cruzi. In chronic phase, vaccinated/infected mice exhibited a significant decline (up to 70%) in IFN-?(+)CD8(+)T cells, a predominance of immunoregulatory IL-10(+)/CD4(+)T and IL10(+)/CD8(+)T cells, and presented undetectable tissue parasitism, inflammatory infiltrate, and fibrosis in vaccinated/infected mice. In comparison, control mice responded to challenge infection by a low antibody response, mixed cytokine profile, and consistent activation of pro-inflammatory CD8(+)T cells associated with parasite persistence and pathologic damage in the heart. We conclude that TcVac3 elicited type-1 effector T cell immunity that effectively controlled T. cruzi infection, and subsequently, predominance of anti-inflammatory responses prevented chronic inflammation and myocarditis in chagasic mice. PMID:23555672

  1. Direct Pen Writing of High-Tc , Flexible Magnesium Diboride Superconducting Arrays.

    PubMed

    Xue, Mianqi; Chen, Dong; Long, Yujia; Wang, Peipei; Zhao, Lingxiao; Chen, Genfu

    2015-06-01

    High-Tc , flexible MgB2 -nanowire-based superconducting arrays are fabricated via a direct pen writing method on both copper foils and poly(dimethylsiloxane) (PDMS) substrates. Such superconducting arrays constitute a new approach for fabricating superconducting devices. The realization of a PDMS-based device demonstrates the potential for expanding this material into other high-Tc superconductor systems, which may lead to novel ways of driving the development of "real-life" applications. PMID:25974155

  2. 99mTc-MIBI SPECT in Distinguishing Neoplastic from Nonneoplastic Intracerebral Hematoma

    Microsoft Academic Search

    Fabio Minutoli; Filippo F. Angileri; Sebastiano Cosentino; Giorgio Restifo Pecorella; Salvatore Cardali; Oreste De Divitiis; Sergio Baldari

    Distinguishing neoplastic from nonneoplastic intracerebral hema- toma has great clinical relevance for the appropriate management of patients. Imaging is not always able to clearly identify a tumor- related intraparenchymal cerebral hemorrhage (ICH), especially in the acute phase, the diagnosis being frequently based on evolution patterns. The aim of this study was to test the value of 99mTc- methoxyisobutylisonitrile (99mTc-MIBI) SPECT

  3. Extraction of Am, Eu, Tc, and Pd from nitric acid solutions with phosphorylated calixarenes

    Microsoft Academic Search

    I. V. Smirnov; M. D. Karavan; T. I. Efremova; V. A. Babain; S. I. Miroshnichenko; S. A. Cherenok; V. I. Kal’chenko

    2007-01-01

    Extraction of Am, Eu, Pd, and Tc from 0.1–3.0 M HNO3 with solutions of phosphorylated calix[n]arenes in m-nitrobenzotrifluoride (NBTF) was studied. The ring size and position of phosphoryl groups (in the upper or lower rim) affect\\u000a the extraction of Am and Eu significantly and that of Tc and Pd only slightly. Calix[4]arenes phosphorylated at the upper\\u000a rim extract Am and

  4. DC and AC Shielding Properties of Bulk High-Tc Superconducting Tubes

    Microsoft Academic Search

    Jean-Francois Fagnard; Samuel Denis; Gregory Lousberg; Michel Dirickx; Marcel Ausloos; Benoit Vanderheyden; Philippe Vanderbemden

    2009-01-01

    We have studied numerically and experimentally the magnetic flux penetration in high-Tc superconducting tube subjected to a uniform magnetic field parallel to its long axis. This study is carried in view of designing low-frequency magnetic shields by exploiting the diamagnetic properties of high-Tc superconducting ceramics. We have measured the field attenuation for applied magnetic fields in the frequency range 5

  5. Evaluation of polyethylene glycol coated liposomes labeled with Tc-99m as a blood pool agent

    SciTech Connect

    Phillips, W.T.; Klipper, R.; Goins, B. [Univ. of Texas Health Science Center, San Antonio, TX (United States)

    1994-05-01

    This investigation evaluated Tc-99m liposomes coated with polyethylene glycol (PEG) as a blood pool agent in comparison with Tc-99m liposomes carrying no surface charge (Neutral) and with Tc-99m autologous red cells. Liposomes (135 nm diameter) encapsulating glutathione were labeled with Tc-99m using the lipophilic chelator, HMPAO as previously described. Autologous red cells were labeled using an Ultratag kit. Labeling efficiencies averaged 66%, 52%, and 97% for the PEG liposomes. Neutral liposomes, and red cells, respectively. Rabbits (3-3.5 Kg) were injected IV via ear vein with 2.0 mls of PEG liposomes (2 mCi, 17 mg phospholipid/Kg body weight, n=5). Neutral liposomes (1.3 mCi, 17 mg phospholipid/Kg body weight, n=4), or red cells (2.6 mCi, n=2). Gamma camera images were acquired at 5,22, and 45 minutes, and 2,20,and 44 hours post-injection. Blood samples were obtained at each time point to determine clearance kinetics. Circulation half lives of both Tc-99m liposome formulations were longer than Tc-99m red cells (8 hrs), with the half life of PEG liposomes (35 hrs) 1.6 times longer than Neutral liposomes (22 hrs). In vivo stability of the Tc-99m label was excellent for the liposomes with only 3.5-4% bladder activity at 45 minutes compared to 12% bladder activity for the red cells. Excellent blood pool images were obtained for the PEG liposomes in the rabbit. Heart/liver ratios calculated from region of interest analysis of 45 minutes images were 1.9, 1.5, and 1.7 for PEG liposomes, Neutral liposomes and red cells. This study demonstrates the feasibility of using Tc-99m PEG liposomes to perform gated cardiac blood pool and rapid gastrointestinal bleeding studies.

  6. Development and study of high-Tc superconductor conductive polymer assemblies

    Microsoft Academic Search

    Steen Brian Schougaard

    2002-01-01

    This dissertation presents the development and study of organic polymeric conductor\\/High-Tc superconductor bilayers, for exploration of the superconductor proximity effect. A major obstacle to this research is the instability of the High-Tc superconductor towards H2O and CO2 as it is necessary to create hybrid structures where the two conductors have intimate contact. For this reason, a study of the corrosion

  7. Three-Component Spectroelectrochemical Sensor Module for the Detection of Pertechnetate (TcO4-)

    SciTech Connect

    Chatterjee, Sayandev; Bryan, Samuel A.; Seliskar, Carl J.; Heineman, William R.

    2013-07-01

    This review looks at the advancements in the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the vadose zone and associated subsurface water. Subsurface contamination by Tc is of particular concern for two reasons: the extremely long lifetime of its most common isotope 99Tc (half-life = 2 x 105 years) and the fast migration in soils of pertechnetate (TcO4–) which is considered to be the dominant 99Tc species in ground water. TcO4– does not have a characteristic spectral signature which prevents its rapid, sensitive, and economic in-situ detection. To address this problem, a novel spectroelectrochemical sensor has been designed that combines three modes of selectivity (electrochemistry, spectroscopy, and selective partitioning) into a single sensor to substantially improve specificity which is critical in the specific detection of an analyte in the presence of potential interfering species. The sensor consists of a basic spectroelectrochemical configuration: a waveguide with an optically transparent electrode (OTE) that is coated with a thin chemically-selective film that preconcnetrates the analyte. The key to adapting this generic sensor to detect TcO4– and Tc complexes lies in the development of chemically-selective films that preconcentrate the analyte and, when necessary, chemically convert it into a complex with electrochemical and spectroscopic properties appropriate for sensing. This review focuses on the general concept of the sensor and the rationale for the selection of the specific components of choice, the development and characterization of the sensor for the different detection modules, the synthesis and characterization of complexes relevant in the detection of technetium, and the progress in the utilization of the sensor module for the effective detection of these complexes.

  8. Tc99m-MIBI scintigraphy for recurrent hyperparathyroidism after total parathyroidectomy with autograft

    Microsoft Academic Search

    Kazuo Itoh; Reiki Ishizuka

    2003-01-01

    The aim of this study is to assess the sensitivity of Tc-99m-MIBI for the pre-operative localization of hyperfunctioning parathyroid\\u000a glands in patients with persistent or recurrent hyperparathyroidism (HPT) after total parathyroidectomy (PTX) with autograft.Patients and Methods: Tc-99m-MIBI scintigraphy was performed on 7 patients (3 men and 4 women; aged 32 to 62) on hemodialysis with persistent\\u000a or recurrent HPT after

  9. Problems in the scintigraphic detection of osteomyelitis in children. [/sup 99m/Tc-pyrophosphate

    SciTech Connect

    Sullivan, D.C.; Rosenfield, N.S.; Ogden, J.; Gottschalk, A.

    1980-06-01

    /sup 99m/Tc pyrophosphate studies in 21 children with acute hematogenous osteomyelitis were compared with radiographic, clinical and surgical findings. Eleven /sup 99m/Tc studies revealed obvious abnormalities, four showed subtle abnormalities, two were misleading, and four were normal. No consistent explanation for the lack of positive radionuclide findings was found. We concluded that pediatric osteomyelitis presents a spectrum of scintigraphic appearances and interpretation is often difficult.

  10. Scintigraphic detection of osteomyelitis with Tc-99m MDP and Ga-67 citrate: concise communication. [Rabbits

    SciTech Connect

    Graham, G.D.; Lundy, M.M.; Frederick, R.J.; Hartshorne, M.F.; Berger, D.E.

    1983-11-01

    Using both Tc-99m methylene diphosphonate and gallium-67 citrate, images of the lower extremities in New Zealand white rabbits were obtained on sequential days after inoculation of tibias with Staphylococcus aureus. Gallium-67 scintigraphy was positive earlier in the course of infection than Tc-99m MDP scintigraphy. In addition to 4-hr Ga-67 scintigrams, 24-hr and 48-hr scintigrams were obtained contributing substanitally to interpretation. However, 72-hr Ga-67 scintigrams contributed little additional information.

  11. High spin shell model states in the isotope [sub 43][sup 90]Tc[sub 47

    Microsoft Academic Search

    D. Rudolph; C. J. Gross; M. K. Kabadiyski; K. P. Lieb; M. Weiszflog; H. Grawe; J. Heese; K. Maier; J. Eberth

    1993-01-01

    High spin states in the nucleus [sup 90]Tc have been identified for the first time via the fusion evaporation reaction [sup 58]Ni([sup 36]Ar,3[ital pn])[sup 90]Tc, at 149 MeV beam energy. The OSIRIS spectrometer with an additional high purity Ge detector at 162[degree] and several particle detectors were used to measure [gamma][gamma] and particle-[gamma][gamma] coincidences, directional correlations of oriented states (DCO's),

  12. High spin shell model states in the isotope 9043Tc47

    Microsoft Academic Search

    D. Rudolph; C. J. Gross; M. K. Kabadiyski; K. P. Lieb; M. Weiszflog; H. Grawe; J. Heese; K.-H. Maier; J. Eberth

    1993-01-01

    High spin states in the nucleus 90Tc have been identified for the first time via the fusion evaporation reaction 58Ni(36Ar,3pn)90Tc, at 149 MeV beam energy. The OSIRIS spectrometer with an additional high purity Ge detector at 162° and several particle detectors were used to measure gammagamma and particle-gammagamma coincidences, directional correlations of oriented states (DCO's), and line shapes due to

  13. 99m Tc-HMDP accumulation in a phyllodes tumor of the breast, a case report

    Microsoft Academic Search

    Hitoya Ohta; Tomoo Komibuchi; Ryuichiro Adachi; Hiroshi Otani; Hideyo Takeda; Kanji Hamazaki; Kazuyo Shimizu; Toshikatsu Taniguchi; Kunikatsu Irie; Kazutaka Yamamoto

    1993-01-01

    In a patient with breast tumor,99mTc-HMDP accumulation in the tumor was recognized in evaluating bone metastasis. Surgery and histopathology revealed that the\\u000a tumor was a phyllodes tumor. This scintigraphic finding was thought to be rare and phyllodes tumor should be included in differential\\u000a diagnosis when99mTc-HMDP accumulation in the breast was recognized.

  14. Adsorption of 99mTc-Radiopharmaceuticals onto Injection Vials and Syringes

    Microsoft Academic Search

    Ahmad Mushtaq; Muhammad Safdar Mansur; Mustanser Jehangir

    2008-01-01

    Many groups have reported the adsorption or retention of 99mTc- radiopharmaceuticals on injection vials and disposable plastic syringes. Such an enormously high loss of radioactivity would re- sult in poor images, radiation exposure, waste, and economic burdens. We therefore decided to investigate the extent of ad- sorption or retention of several 99mTc-radiopharmaceuticals on injection vials,rubber stoppers, and plastic syringes. These

  15. Chemical Manipulation of High-TC Ferromagnetism in ZnO Diluted Magnetic Semiconductors

    Microsoft Academic Search

    Kevin R. Kittilstved; Nick S. Norberg; Daniel R. Gamelin

    2005-01-01

    We report the use of targeted p- and n-type chemical perturbations to manipulate high-TC ferromagnetism in Mn2+:ZnO and Co2+:ZnO in predictable and reproducible ways. We demonstrate a clear correlation between nitrogen and high-TC ferromagnetism for Mn2+:ZnO and an inverse correlation for Co2+:ZnO, both as predicted by recent theoretical models. These chemical perturbations reveal rich possibilities for exerting external control over

  16. Characterization of reverse transcriptase activity of the L1Tc retroelement from Trypanosoma cruzi.

    PubMed

    García-Pérez, J L; González, C I; Thomas, M C; Olivares, M; López, M C

    2003-12-01

    The recombinant protein RTL1Tc, encoded by the non-LTR (long terminal repeat) retrotransposon L1Tc from Trypanosoma cruzi, has been shown to have reverse transcriptase (RT) activity using poly(rA)/oligo(dT) and poly(rC)/oligo(dG) homopolymers as template/primers. The optimal RT activity was detected at a concentration of 5 mM Mg2+, pH 8 and between 28 and 37% degrees C. Site-directed mutagenesis in the RT catalytic site proved that substitution of aspartic acid 313 for isoleucine (RT D313IL1Tc) practically abolishes the RT activity of the RTL1Tc protein. RT-polymerase chain reaction assays revealed that the RTL1Tc protein has the ability to use both homologous and heterologous RNA templates. Also, it is shown that the RTL1Tc protein is capable of synthesizing complementary DNA molecules by consecutive switching of the oligo molecule, which the protein uses as a template. This template switching may be involved in the retroelement integration process. PMID:14685692

  17. Dopamine Transporter Imaging Using 99mTc-TRODAT-1 SPECT in Parkinson’s Disease

    PubMed Central

    Bor-Seng-Shu, Edson; Felicio, Andre C.; Braga-Neto, Pedro; Batista, Ilza Rosa; Paiva, Wellingson Silva; de Andrade, Daniel Ciampi; Teixeira, Manoel Jacobsen; de Andrade, Luiz Augusto Franco; Barsottini, Orlando Graziani Povoas; Shih, Ming Chi; Bressan, Rodrigo A.; Ferraz, Henrique Ballalai

    2014-01-01

    Background Although the decrease in striatal dopamine transporter (DAT) density has been described in North American, European, and Asian Parkinson’s disease (PD) patients, studies on this issue are required in the rest of the world. This study examined the diagnostic utility of DAT imaging in Brazilian PD patients. Material/Methods Twenty PD patients (13 males, 7 females, median age: 62 years, median age at disease onset: 56 years, median disease duration: 5 years, and median UPDRS-III score: 29) and 9 age- and sex-matched healthy subjects underwent single-photon emission computerized tomography (SPECT) using 99mTc-TRODAT-1. Results PD patients showed a significant decrease in the striatum, caudate nucleus, and putamen DAT densities compared with data from healthy subjects. Striatal 99mTc-TRODAT-1 bindings had the highest diagnostic accuracy compared to those estimates from caudate nucleus and putamen. For the diagnosis of PD, a striatal 99mTc-TRODAT-1 binding cut-off value of 0.90 was associated with a sensitivity of 100% and a specificity of 89%. There was no significant difference between striatal 99mTc-TRODAT-1 binding values provided by different readers, contrary to 99mTc-TRODAT-1 binding estimates in the caudate nucleus. Conclusions Striatal DAT imaging using 99mTc-TRODAT-1 can be considered a marker for differentiating PD patients from healthy individuals, with a good interobserver reproducibility. PMID:25109468

  18. Controlling factors of Tc dome structure in 1111-type iron arsenide superconductors

    NASA Astrophysics Data System (ADS)

    Matsuishi, Satoru; Maruyama, Takuya; Iimura, Soshi; Hosono, Hideo

    2014-03-01

    We investigated the effects of phosphorus substitution on the shape of the Tc(x ) dome in 1111-type SmFeAs1 -yPyO1 -xHx (0 < x < 0.5). Hydride ion substitution of oxide sites (O2 - ? H-) exerts a chemical pressure effect, i.e., a structural reduction of the Pn-Fe-Pn angle ? (Pn = P, As) and also dopes electrons into the FePn layer to induce superconductivity. Isovalent phosphorus substitution (P3 - ? As3 -) can induce only a chemical pressure effect, i.e., an increase of ? for La substitution of Sm sites. As y increases from 0.0 to 0.5, the single Tc dome gradually splits into two domes, similar to those of LaFeAsO1 -xHx with a Tc valley at x ? 0.16. We found that the Tc valley is located around (x , ?) ? (0.16, 113°) for both of the SmFeAs1 -yPyO1 -xHx and LaFeAsO1 -xHx series, irrespective of changes in the Pn anion and Ln cation species. This result suggests that suppression of Tc leads to the emergence of a Tc valley when both the shape of FeP n4 tetrahedra represented by ? and electron-doping level of x meet the above criterion in 1111-type iron oxypnictide superconductors.

  19. SOLVENT EXTRACTION OF 99Tc FROM RADIOACTIVE INTERMEDIATE LIQUID WASTE BY DIBENZO-18-CROWN-6

    SciTech Connect

    Paviet-Hartmann, P.

    2002-02-25

    Technetium is one of the most prominent problems since its most stable specie in the environment, the pertechnetate ion, is highly mobile and considered as a long-term hazard in nuclear waste disposal. Because of the small activities of 99Tc relative to other fission products 137Cs or 90Sr, and its long half-life time (t1/2 = 2.1 x 105 yrs), 99Tc is one of the key isotopes that should always be analyzed in the radioactive liquid waste streams from the reprocessing industry where the largest concentrations are to be expected. Furthermore, as a pure beta-emitter, 99Tc has to be isolated from the intermediate level waste (ILW) stream prior to any measurement in such complex media. We have developed a method for 99Tc extraction providing recommendations that will be useful for extracting it from acid and basic ILW. The extraction of 99Tc from ILW by dibenzo-18-crown-6 (DB18C6) has been investigated and a simplex optimization of key parameters involved in the procedure has allowed us to set u p their best values. Experiments have been carried out on synthetic and real effluents from La Hague reprocessing plant, France, and results show that DB18C6 is highly selective towards 99Tc. The application of this procedure has been successfully demonstrated through the analysis of actual waste streams coming from two reprocessing plants at La Hague and Marcoule, France.

  20. Solvent extraction of 99Tc from radioactive intermediate liquid waste by dibenzo-18-crown-6.

    SciTech Connect

    Paviet-Hartmann, P. (Patricia)

    2001-01-01

    Technetium is one of the most prominent problems since its most stable specie in the environment, the pertechnetate ion, is highly mobile and considered as a long-term hazard in nuclear waste disposal. Because of the small activities of 99Tc relative to other fission products 137Cs or 90Sr, and its long half-life time (t1/2 = 2.1x10{sup 5} yrs), 99Tc is one of the key isotopes that should always be analyzed in the radioactive liquid waste streams from the reprocessing industry where the largest concentrations are to be expected. Furthermore, as a pure betaemitter, 99Tc has to be isolated from the intermediate level waste (ILW) stream prior to any measurement in such complex media. We have developed a method for 99Tc extraction providing recommendations that will be useful for extracting it from acid and basic ILW. The extraction of 99Tc from ILW by dibenzo-18-crown-6 (DB18C6) has been investigated and a simplex optimization of key parameters involved in the procedure has allowed us to set up their best values. Experiments have been carried out on synthetic and real effluents from La Hague reprocessing plant, France, and results show that DB18C6 is highly selective towards 99Tc. The application of this procedure has been successfully demonstrated through the analysis of actual waste streams coming from two reprocessing plants at La Hague and Marcoule, France.

  1. Functional Characterization of Human Tc0, Tc1 and Tc2 CD8+ T Cell Clones: Control of X4 and R5 HIV Strain Replication

    Microsoft Academic Search

    Michèle Février; Sylviele Borgne; Christian Marty; Antoine Talarmin; Yves Rivière

    2004-01-01

    CD8+ T lymphocytes have the potential ability to inhibit human immunodeficiency virus (HIV) replication, by secreting soluble(s) factor(s) known as CD8+ T lymphocyte antiviral factor (CAF). A panel of CD8+ and CD4+ T cell clones from HIV1-infected and uninfected donors were generated to better define the phenotype of CAF-producing cells. We first verified that the different CD4+ T cell subsets

  2. Towards universal code generator generation

    Microsoft Academic Search

    Timothy Richards; Edward K. Walters II; J. Eliot B. Moss; Trek S. Palmer; Charles C. Weems

    2008-01-01

    One of the most difficult tasks a compiler writer faces is the construction of the code generator. The code generator is that part of the compiler that translates compiler intermediate representation (IR) into instructions for a target machine. Unfortunately, implementing a code generator \\

  3. Distribution of orally administered and chronically fed /sup 95m/Tc in Japanese quail tissues and eggs

    SciTech Connect

    Thomas, J.M.; Cadwell, L.L.; Garland, T.R.; Cataldo, D.A.

    1984-10-01

    Previous coefficients for transfer of technetium from feed to poultry have utilized default values. These investigations examined the uptake and distribution of /sup 95m/Tc in male and female Japanese quail following their ingestion of Tc incorporated into alfalfa during growth. Approximately 8% of the daily ingested Tc was transferred to eggs. Biological half-time was one to two days. After 10 days of feeding, 80% of the Tc was in yolk, 20% in albumin, and less than 1% in shell and associated membranes. The Tc levels in albumin reached a maximum between three and five days, compared to six to seven days for yolk. Laying female quail contained 27% of the daily-ingested Tc compared to 5% for males. However, approximately 23% of the daily female Tc intake was contained in the developing ova and reproductive organs. The highest Tc concentrations were in oocytes of laying hens, followed by the fully formed unlaid egg and the ovaries. The uterine shelled egg contained five times the amount of Tc present in other edible tissues combined. For males, the gizzard contained about 53% of the Tc in other edible tissues, followed by muscle (25%), liver (19%), and hea

  4. High-Tc nodeless s±-wave superconductivity in (Y,La)FeAsO(1-y) with Tc=50 K:75As-NMR study.

    PubMed

    Mukuda, H; Furukawa, S; Kinouchi, H; Yashima, M; Kitaoka, Y; Shirage, P M; Eisaki, H; Iyo, A

    2012-10-12

    We report on an (75)As-NMR study on the Fe-pnictide high-T(c) superconductor Y(0.95)La(0.05)FeAsO(1-y) (Y(0.95)La(0.05)1111) with T(c)=50 K that includes no magnetic rare-earth elements. The measurement of the nuclear-spin lattice-relaxation rate (75)(1/T(1)) has revealed that the nodeless bulk superconductivity takes place at T(c)=50 K while antiferromagnetic spin fluctuations develop moderately in the normal state. These features are consistently described by the multiple fully gapped s(±)-wave model based on the Fermi-surface nesting. Incorporating the theory based on band calculations, we propose that the reason that T(c)=50 K in Y(0.95)La(0.05)1111 is larger than T(c)=28 K in La1111 is that the Fermi-surface multiplicity is maximized, and hence the Fermi-surface nesting condition is better than that in La1111. PMID:23102353

  5. Quantitative analysis by digital computer of Tc-99m N-pyridoxyl-5-methyltryptophan (Tc-99m PMT) hepatogram in diffuse parenchymal liver diseases

    SciTech Connect

    Narabayashi, I.; Ishido, N.; Sugimura, K.; Nabeshima, K.; Sugimura, C.; Matsuo, M.; Kimura, S.; Kajita, A.

    1984-01-01

    Tc-99m N-pyridoxyl-5 methyltryptophan (Tc-99m PMT) hepatograms were analyzed to provide information about the liver and bile duct. Calculations were based on a 4 compartmental model and included corrections for blood, tissue, liver and bile backgrounds. The time-activity curves for Tc-99m PMT in the cardiac region were described as the sum of 2 exponential functions, while curves for the hepatic region were described as the sum of 3 exponential components. The measured hepatograms were compared with simulated hepatograms and good agreement between the two curves showed that the compartmental model adequately described the blood and bile activities in vivo. Hepatic excretion rates were 0.179 +- 0.028 in 3 normal subjects. 0.102 +- 0.012 in 4 patients of chronic hepatitis and 0.116 +- 0.061 in 6 patients of liver cirrhosis. In the cases of diffuse parenchyal liver diseases, there were lower rate constants for the excretion from the liver to the bile ducts than in normals and the relative distribution values also larger than normal. Prior to the development of this compartmental model, no useful kinetic model had been found which could satisfactorily explain the time-activity curves. Experience in human studies proves this method to be accurate in determining the rate constants for hepatobiliary transport of Tc-99m PMT.

  6. Biogeochemistry of Fe and Tc Reduction and Oxidation in FRC Sediment

    SciTech Connect

    John M. Zachara; James K. Fredrickson; Ravi K. Kukkadapu; Steven C. Smith; David W. Kennedy

    2004-03-17

    The objectives are: (1) To rigorously characterize the distribution of Fe(II) and Fe(III) in FRC sediment. (2) To identify changes to Fe(II)/Fe(III) distribution and concentration resulting from DIRB activity. (3) To determine the dependence of Tc(VII) reduction rate on biogenic Fe(II) and it's forms. (4) To establish tendency of Tc(IV) and biogenic Fe(II) to oxidize and their effects on Tc immobilization. The mineralogic and chemical properties of the pristine, bioreduced, and chemically extracted FRC sediments were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray microscopy (XRM, at the PNC-CAT beamline at APS), Moessbauer spectroscopy, and scanning and transmission electron microscopy with lattice fringe imaging. Chemical extraction included dithionite-citrate-bicarbonate (DCB), acid ammonium oxalate (AAO), and hydroxylamine hydrochloride (HAH). The FRC sediment was incubated under anoxic conditions with the facultative dissimilatory metal-reducing bacterium Shewanella putrefaciens, strain CN32 in defined aqueous solutions/media with bicarbonate and PIPES buffers for time periods exceeding 75 d. Lactate was used as the electron donor. Aqueous and sorbed Fe(II) (ferrozine assay and 0.5 N HCl extraction) and Mn(II) (ICP-MS and 10 mM CuSO{sub 4} extraction), and pH were monitored to define the reduction progress and extent. The bioreduced materials were characterized using the abovementioned techniques. Bioreduced (pasteurized) sediment or chemically extracted/reduced sediment spiked with Fe(II) was washed with a PIPES buffer/electrolyte solution, and spiked with NaTc(VII)O{sub 4} to yield a concentration of 20 {micro}M. The Tc(VII)-spiked samples were agitated and equilibrated at 25 C and sampled over time to assess the Tc(VII) reduction rate. Selected sediment samples containing 20 {micro}M of reduced Tc [Tc(IV)] were subjected to oxidation by: (1) successive headspace replacements of air, and (2) open system equilibration with air. Removed aqueous samples were filtered (< 2 {micro}m) and counted to determine the Tc(VII) concentration. Thin sections of the bioreduced/chemically reduced Tc(VII) reacted/oxidized sediments were analyzed by backscattered electron microscopy and X-ray microspectroscopy.

  7. Heterogeneous reduction of Tc(VII) by Fe(II) at the solid water interface

    NASA Astrophysics Data System (ADS)

    Peretyazhko, T.; Zachara, J. M.; Heald, S. M.; Jeon, B.-H.; Kukkadapu, R. K.; Liu, C.; Moore, D.; Resch, C. T.

    2008-03-01

    Experiments were performed herein to investigate the rates and products of heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to hematite and goethite, and by Fe(II) associated with a dithionite-citrate-bicarbonate (DCB) reduced natural phyllosilicate mixture [structural, ion-exchangeable, and edge-complexed Fe(II)] containing vermiculite, illite, and muscovite. The heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to the Fe(III) oxides increased with increasing pH and was coincident with a second event of Fe2+(aq) adsorption. The reaction was almost instantaneous above pH 7. In contrast, the reduction rates of Tc(VII) by DCB-reduced phyllosilicates were not sensitive to pH or to added Fe2+(aq) that adsorbed to the clay. The reduction kinetics were orders of magnitude slower than observed for the Fe(III) oxides, and appeared to be controlled by structural Fe(II). The following affinity series for heterogeneous Tc(VII) reduction by Fe(II) was suggested by the experimental results: aqueous Fe(II) ˜ adsorbed Fe(II) in phyllosilicates [ion-exchangeable and some edge-complexed Fe(II)] ? structural Fe(II) in phyllosilicates ? Fe(II) adsorbed on Fe(III) oxides. Tc-EXAFS spectroscopy revealed that the reduction products were virtually identical on hematite and goethite that were comprised primarily of sorbed octahedral TcO 2 monomers and dimers with significant Fe(III) in the second coordination shell. The nature of heterogeneous Fe(III) resulting from the redox reaction was ambiguous as probed by Tc-EXAFS spectroscopy, although Mössbauer spectroscopy applied to an experiment with 56Fe-goethite with adsorbed 57Fe(II) implied that redox product Fe(III) was goethite-like. The Tc(IV) reduction product formed on the DCB-reduced phyllosilicates was different from the Fe(III) oxides, and was more similar to Tc(IV) oxyhydroxide in its second coordination shell. The heterogeneous reduction of Tc(VII) to less soluble forms by Fe(III) oxide-adsorbed Fe(II) and structural Fe(II) in phyllosilicates may be an important geochemical process that will proceed at very different rates and that will yield different surface species depending on subsurface pH and mineralogy.

  8. Genetic mapping in maize with hybrid progeny across testers and generations: plant height and flowering

    Microsoft Academic Search

    D. F. Austin; M. Lee; L. R. Veldboom

    2001-01-01

    DNA markers were used to identify quantitative trait loci (QTLs) for plant height, ear height, and three flowering traits\\u000a in hybrid progeny of two generations (F2:3, F6:8) of lines from a Mo17×H99 maize population. For both generations, testcross (TC) progeny were developed by crossing the lines\\u000a to three inbred testers (B91, A632, B73). The hybrid progeny from the two generations

  9. Substrate Specificity and Colorimetric Assay for Recombinant TrzN Derived from Arthrobacter aurescens TC1

    PubMed Central

    Shapir, Nir; Rosendahl, Charlotte; Johnson, Gilbert; Andreina, Marco; Sadowsky, Michael J.; Wackett, Lawrence P.

    2005-01-01

    The TrzN protein, which is involved in s-triazine herbicide catabolism by Arthrobacter aurescens TC1, was cloned and expressed in Escherichia coli as a His-tagged protein. The recombinant protein was purified via nickel column chromatography. The purified TrzN protein was tested with 31 s-triazine and pyrimidine ring compounds; 22 of the tested compounds were substrates. TrzN showed high activity with sulfur-substituted s-triazines and the highest activity with ametryn sulfoxide. Hydrolysis of ametryn sulfoxide by TrzN, both in vitro and in vivo, yielded a product(s) that reacted with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl) to generate a diagnostic blue product. Atrazine chlorohydrolase, AtzA, did not hydrolyze ametryn sulfoxide, and no color was formed by amending those enzyme incubations with NBD-Cl. TrzN and AtzA could also be distinguished by reaction with ametryn. TrzN, but not AtzA, hydrolyzed ametryn to methylmercaptan. Methylmercaptan reacted with NBD-Cl to produce a diagnostic yellow product having an absorption maximum at 420 nm. The yellow color with ametryn was shown to selectively demonstrate the presence of TrzN, but not AtzA or other enzymes, in whole microbial cells. The present study was the first to purify an active TrzN protein in recombinant form and develop a colorimetric test for determining TrzN activity, and it significantly extends the known substrate range for TrzN. PMID:15870302

  10. Assessment of the role in protection and pathogenesis of the Chlamydia muridarum V-type ATP synthase subunit A (AtpA) (TC0582)

    PubMed Central

    Pal, Sukumar; Tifrea, Delia; Sun, Guifeng; Teng, Andy A.; Liang, Xiaowu; Felgner, Philip L.; de la Maza, Luis M.

    2014-01-01

    A novel Chlamydia muridarum antigen (TC0582) was used to vaccinate BALB/c mice. Mice were also immunized with other components of the ATP synthase complex (TC0580, TC0581, and TC0584), or with the major outer membrane protein (MOMP). TC0582 was also formulated in combination with TC0580, TC0581 or MOMP. TC0582 alone, or in combination with the other antigens, elicited strong Chlamydia-specific humoral and cellular immune responses. Vaccinated animals were challenged intranasally and the course of the infection was followed for 10 days. Based on percentage change in body weight, lung weight, and number of Chlamydia inclusion forming units recovered from the lungs, mice immunized with TC0582, TC0581 or MOMP, as single antigens, showed significant protection. Mice immunized with combinations of two antigens were also protected but the level of protection was not additive. TC0582 has sequence homology with the eukaryotic ATP synthase subunit A (AtpA). Therefore, to determine if immunization with TC0582, or with Chlamydia, elicited antibodies that cross-reacted with the mouse AtpA, the two proteins were printed on a microarray. Sera from mice immunized with TC0582 and/or live Chlamydia, strongly reacted with TC0582 but did not recognize the mouse AtpA. In conclusion, TC0582 may be considered as a Chlamydia vaccine candidate. PMID:24161793

  11. Transgenic maize event TC1507: Global status of food, feed, and environmental safety.

    PubMed

    Baktavachalam, Gajendra B; Delaney, Bryan; Fisher, Tracey L; Ladics, Gregory S; Layton, Raymond J; Locke, Mary Eh; Schmidt, Jean; Anderson, Jennifer A; Weber, Natalie N; Herman, Rod A; Evans, Steven L

    2015-04-01

    Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7-1) or the Herculex®(#) I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001. A science-based safety assessment was conducted on TC1507 prior to commercialization. The safety assessment addressed allergenicity; acute oral toxicity; subchronic toxicity; substantial equivalence with conventional comparators, as well as environmental impact. Results from biochemical, physicochemical, and in silico investigations supported the conclusion that Cry1F and PAT proteins are unlikely to be either allergenic or toxic to humans. Also, findings from toxicological and animal feeding studies supported that maize with TC1507 is as safe and nutritious as conventional maize. Maize with TC1507 is not expected to behave differently than conventional maize in terms of its potential for invasiveness, gene flow to wild and weedy relatives, or impact on non-target organisms. These safety conclusions regarding TC1507 were acknowledged by over 20 regulatory agencies including United States Environment Protection Agency (US EPA), US Department of Agriculture (USDA), Canadian Food Inspection Agency (CFIA), and European Food Safety Authority (EFSA) before authorizing cultivation and/or food and feed uses. A comprehensive review of the safety studies on TC1507, as well as some benefits, are presented here to serve as a reference for regulatory agencies and decision makers in other countries where authorization of TC1507 is or will be pursued. PMID:26018138

  12. A New Mechanism for High-Tc:. Electron Scattering from Interacting Tunneling Units

    NASA Astrophysics Data System (ADS)

    Klein, Michael W.; Simanovsky, Sergey B.

    A theoretical model for high-Tc superconductivity is presented based on electron pairing due to their interaction with two-level or multi-level tunneling units (TU's) present in high-Tc materials. TU's were found experimentally in YBa2Cu3O7-?, Bi2CaSr2Cu2O8, Tl2CaBa2Cu2O8 and in Tl2CaBa2CuO6. The TU's have specific directions of orientation with respect to the crystal axis and hence cause a strongly anisotropic scattering of the conduction electrons and a strongly anisotropic gap function ?(k) with wave vector k. For the weak coupling case we obtain, (i) an analytically derived ?(k) which has a linear combination of s-wave and dx2-y2-wave symmetry with nodes in ?(k), (ii) a high-Tc determined by the elastic interaction potential between the TU's, (iii) an isotope effect consistent with experiment, (iv) a large uniaxial pressure p dependence of Tc for YBa2Cu3O7-? close to optimal oxygen doping and (dTc/dpa) ? -(dTc/dpb) where Pa and Pb are the pressures in the a and b directions, (v) a quantitative agreement with experiment for dTc/dPi (i = a, b) when we use the elastic constant. The recently observed d ± s wave pairing in twinned YBa2Cu3O7-?, with a reversal of the sign of s-wave component across the twin boundary, is also in agreement with our model.

  13. Protein profiles in Tc1 mice implicate novel pathway perturbations in the Down syndrome brain

    PubMed Central

    Ahmed, Md. Mahiuddin; Dhanasekaran, A. Ranjitha; Tong, Suhong; Wiseman, Frances K.; Fisher, Elizabeth M.C.; Tybulewicz, Victor L.J.; Gardiner, Katheleen J.

    2013-01-01

    Tc1 mouse model of Down syndrome (DS) is functionally trisomic for ?120 human chromosome 21 (HSA21) classical protein-coding genes. Tc1 mice display features relevant to the DS phenotype, including abnormalities in learning and memory and synaptic plasticity. To determine the molecular basis for the phenotypic features, the levels of 90 phosphorylation-specific and phosphorylation-independent proteins were measured by Reverse Phase Protein Arrays in hippocampus and cortex, and 64 in cerebellum, of Tc1 mice and littermate controls. Abnormal levels of proteins involved in MAP kinase, mTOR, GSK3B and neuregulin signaling were identified in trisomic mice. In addition, altered correlations among the levels of N-methyl-D-aspartate (NMDA) receptor subunits and the HSA21 proteins amyloid beta (A4) precursor protein (APP) and TIAM1, and between immediate early gene (IEG) proteins and the HSA21 protein superoxide dismutase-1 (SOD1) were found in the hippocampus of Tc1 mice, suggesting altered stoichiometry among these sets of functionally interacting proteins. Protein abnormalities in Tc1 mice were compared with the results of a similar analysis of Ts65Dn mice, a DS mouse model that is trisomic for orthologs of 50 genes trisomic in the Tc1 plus an additional 38 HSA21 orthologs. While there are similarities, abnormalities unique to the Tc1 include increased levels of the S100B calcium-binding protein, mTOR proteins RAPTOR and P70S6, the AMP-kinase catalytic subunit AMPKA, the IEG proteins FBJ murine osteosarcoma viral oncogene homolog (CFOS) and activity-regulated cytoskeleton-associated protein (ARC), and the neuregulin 1 receptor ERBB4. These data identify novel perturbations, relevant to neurological function and to some seen in Alzheimer's disease, that may occur in the DS brain, potentially contributing to phenotypic features and influencing drug responses. PMID:23349361

  14. Expression of an endoglucanase from Tribolium castaneum (TcEG1) in Saccharomyces cerevisiae.

    PubMed

    Shirley, Derek; Oppert, Cris; Reynolds, Todd B; Miracle, Bethany; Oppert, Brenda; Klingeman, William E; Jurat-Fuentes, Juan Luis

    2014-10-01

    Insects are a largely unexploited resource in prospecting for novel cellulolytic enzymes to improve the production of ethanol fuel from lignocellulosic biomass. The cost of lignocellulosic ethanol production is expected to decrease by the combination of cellulose degradation (saccharification) and fermentation of the resulting glucose to ethanol in a single process, catalyzed by the yeast Saccharomyces cerevisiae transformed to express efficient cellulases. While S. cerevisiae is an established heterologous expression system, there are no available data on the functional expression of insect cellulolytic enzymes for this species. To address this knowledge gap, S. cerevisiae was transformed to express the full-length cDNA encoding an endoglucanase from the red flour beetle, Tribolium castaneum (TcEG1), and evaluated the activity of the transgenic product (rTcEG1). Expression of the TcEG1 cDNA in S. cerevisiae was under control of the strong glyceraldehyde-3 phosphate dehydrogenase promoter. Cultured transformed yeast secreted rTcEG1 protein as a functional ?-1,4-endoglucanase, which allowed transformants to survive on selective media containing cellulose as the only available carbon source. Evaluation of substrate specificity for secreted rTcEG1 demonstrated endoglucanase activity, although some activity was also detected against complex cellulose substrates. Potentially relevant to uses in biofuel production rTcEG1 activity increased with pH conditions, with the highest activity detected at pH 12. Our results demonstrate the potential for functional production of an insect cellulase in S. cerevisiae and confirm the stability of rTcEG1 activity in strong alkaline environments. PMID:24318365

  15. An evaluation of /sup 99m/Tc-TMP as a myocardial imaging agent

    SciTech Connect

    Jehangir, M.; Subramanian, G.; McAfee, J.G.; Thomas, F.D.; Gagne, G.; Zapf-Longo, C.; Ritter-Hrncirik, C.

    1985-05-01

    Based on the recent report (JNM 25:P15,'84) that cationic /sup 99m/Tc-TMP localized well in animal myocardium, the authors evaluated it for possible clinical use. It was prepared by heating dry /sup 99m/TcO/sub 4/ with 50 mg of TMP in <0.5 ml of methanol or DMSO at 98/sup 0/C for 30'. This reaction also produced 6-10% of an anionic complex impurity (RPTLC, KC/sub 18/F plate, 2% dimethyl phosphite in methanol). This impurity and unreacted TMP were removed by passing the complex through 3x1cm BIOSIL A column and washing with saline. Carrier free /sup 99m/Tc-TMP was eluted with 0.5 ml ethanol, diluted with saline and injected intravenously to rats, rabbits, cats, dogs and rhesus monkey for gamma camera imaging. Excellent myocardial localization was seen in all animals. The quantitative myocardial uptake of /sup 99m/Tc-TMP in rats was comparable to that of /sup 201/Tl. A normal male volunteer was injected with 6.6 mCi of /sup 99m/Tc TMP and gamma camera images were obtained. By 24 hrs, 16% of the injected dose was recovered in the urine. The /sup 99m/Tc-TMP in plasma was not protein bound as determined by gel chromatography and electrophoresis. There seems to be a wide species difference between man and animals in the pharmacokinetics and localization of /sup 99m/Tc-TMP.

  16. Lemma 3 Let C be any set, and suppose x C, then FC(x) TC(x). If C convex, then C -x FC(x), FC(x) is convex, and TC(x) = cl FC(x).

    E-print Network

    Ferris, Michael C.

    Lemma 3 Let C be any set, and suppose ¯x C, then FC(¯x) TC(¯x). If C convex, then C - ¯x FC(¯x), FC(¯x) is convex, and TC(¯x) = cl FC(¯x). Proof The first statement follows from the definitions. FC(¯x) is convex by direct argument. For the final statement of the lemma, suppose that w TC(¯x

  17. The trajectory and impact circumstances of asteroid 2008 TC3

    NASA Astrophysics Data System (ADS)

    Chodas, Paul; Chesley, S.; Yeomans, D.

    2010-05-01

    On October 6, 2008, the small newly discovered near-Earth asteroid 2008 TC3 was found to be on an Earth-impacting trajectory, with impact less than 20 hours away. This was the first ever predicted impact of a near-Earth object. Fortunately, it was immediately clear that the object was only a few meters in size and would therefore almost certainly break up when it entered the Earth's atmosphere. We review the pre-impact orbit computations and predictions, the post-impact reconstructions of the trajectory, and the trajectory geometry. The first prediction of impact was made by the Minor Planet Center (MPC), which quickly made the discovery and subsequent follow-up observations available to the astronomical community and contacted us at the NASA/JPL Near-Earth Object Program Office. Our impact predictions indicated that the atmospheric entry would occur over northern Sudan around 02:46 UT on October 7. Over the course of the day, the number of observations sky-rocketed to several hundred, and the impact prediction uncertainty shrank to ±3 km. Topocentric parallax up to 15 degrees is present in the data and the rates of motion approached 13.4 arcsec/s prior to the object's disappearance into the Earth's umbra. Detections of the actual atmospheric impact event suggested that it was an airburst explosion at an altitude of 37 km with an energy equivalent of about one kiloton of TNT. The airburst occurred at 02:45:45 UT at about 32.2 East longitude and 20.8 North latitude, matching the final impact predictions to within 0.2 s in time and 1.5 km in position. We compute Monte Carlo clones of the final orbit to investigate possible source orbits. Trajectory dispersions remain fairly compact as far back as 1961 , when an Earth close approach at 0.18 ± 0.12 AU scatters the predictions. Only statistical characterizations of the earlier trajectory are possible.

  18. Biokinetics and dosimetry in patients of 99mTc-EDDA\\/HYNIC-Tyr 3-octreotide prepared from lyophilized kits

    Microsoft Academic Search

    Armando González-Vázquez; Guillermina Ferro-Flores; Consuelo Arteaga de Murphy; Zohar Gutiérrez-García

    2006-01-01

    99mTc-EDDA\\/HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for 99mTc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients

  19. Superconducting Arrays: Direct Pen Writing of High-Tc , Flexible Magnesium Diboride Superconducting Arrays (Adv. Mater. 24/2015).

    PubMed

    Xue, Mianqi; Chen, Dong; Long, Yujia; Wang, Peipei; Zhao, Lingxiao; Chen, Genfu

    2015-06-01

    The booming growth of superconducting technology has been hampered by limited processing technologies to achieve high-Tc superconductor-based flexible arrays. On page 3614, M. Q. Xue, G. F. Chen, and co-workers demonstrate a direct pen writing method for fabricating high-Tc , flexible MgB2 superconducting arrays, which paves the way to real applications of high-Tc superconductors. PMID:26085398

  20. Febrile neutropenia in adjuvant docetaxel and cyclophosphamide (TC) with prophylactic pegfilgrastim in breast cancer patients: a retrospective analysis

    Microsoft Academic Search

    Nuttapong Ngamphaiboon; Tracey L. O’Connor; Pooja P. Advani; Ellis G. Levine; Ellen B. Kossoff

    US Oncology Research Trial 9735 reported that TC improved overall survival when compared to doxorubicin and cyclophosphamide\\u000a in early-stage breast cancer. Despite 61% grades 3–4 neutropenia in the TC arm, only 5% of patients developed febrile neutropenia\\u000a (FN) without primary prophylactic GCSF (ppGCSF). TC has risen in popularity, particularly in older patients or in those where\\u000a an anthracycline is contraindicated.

  1. 99m Tc-glucarate imaging for the early detection of infarct in partially reperfused canine myocardium

    Microsoft Academic Search

    Gerald Johnson; Christine C. Okada; Sonia D. Hocherman; Zhonglin Liu; Curtis Hart; Ban-An Khaw; Robert D. Okada

    2006-01-01

    Purpose  99mTc-glucarate is an imaging agent developed for the detection of acutely infarcted myocardium. The purposes of the current study were to (1) determine whether 99mTc-glucarate can detect acute infarct in the setting of only partial minimal reperfusion, (2) study the persistence and time course of scan positivity following coronary occlusion and intravenous tracer injection, (3) assess the ability of 99mTc-glucarate

  2. An evaluation of the mediastinal lymphoscintigram for carcinoma of the esophagus studied with 99m Tc rhenium sulfur colloid

    Microsoft Academic Search

    Shoji Terui; Hoichi Kato; Toshio Hirashima; Toshifumi Iizuka; Hiyoshimaru Oyamada

    1982-01-01

    Lymphoscintigraphies of esophageal carcinoma in nine patients were studied with the aid of 99mTc-labeled rhenium sulfur colloid (99mTc-Re). 99mTc-Re was injected into the submucosal layer of the esophagus (just above the oral side of the tumor) using an esophagoendoscope, 1 or 2 days before operation. Lymphoscintigraphies at intervals of 1, 3, and 20 h after the injection were performed. After

  3. Observation of the Nernst signal generated by fluctuating Cooper pairs

    Microsoft Academic Search

    A. Pourret; H. Aubin; J. Lesueur; C. A. Marrache-Kikuchi; L. Bergé; L. Dumoulin; K. Behnia

    2006-01-01

    Long-range order is destroyed in a superconductor warmed above its critical temperature (Tc). However, amplitude fluctuations of the superconducting order parameter survive and lead to a number of well-established phenomena, such as paraconductivity: an excess of charge conductivity due to the presence of short-lived Cooper pairs in the normal state. According to theory, these pairs generate a transverse thermoelectric (Nernst)

  4. Transcranial cerebellar direct current stimulation (tcDCS): motor control, cognition, learning and emotions.

    PubMed

    Ferrucci, Roberta; Priori, Alberto

    2014-01-15

    The neurological manifestations of cerebellar diseases range from motor to cognitive or behavioral abnormalities. Experimental data in healthy subjects extend the cerebellar role to learning, emotional and mood control. The need for a non-invasive tool to influence cerebellar function in normal and pathological conditions led researchers to develop transcranial cerebellar direct current stimulation (tcDCS). tcDCS, like tDCS, depends on the principle that weak direct currents delivered at around 2mA for minutes over the cerebellum through surface electrodes induce prolonged changes in cerebellar function. tcDCS modulates several cerebellar skills in humans including motor control, learning and emotional processing. tcDCS also influences the cerebello-brain interactions induced by transcranial magnetic stimulation (TMS), walking adaptation, working memory and emotional recognition. Hence tcDCS is a simple physiological tool that can improve our physiological understanding of the human cerebellum, and should prove useful also in patients with cerebellar dysfunction or psychiatric disorders and those undergoing neurorehabilitation to enhance neuroplasticity. PMID:23664951

  5. Tc-99m macro aggregated albumin scintigraphy – indications other than pulmonary embolism: A pictorial essay

    PubMed Central

    Gandhi, Sunny J; Babu, Sanjay; Subramanyam, Padma; Shanmuga Sundaram, Palaniswamy

    2013-01-01

    Introduction: Tc-99m macro aggregated albumin (MAA) is synonymous for lung perfusion scintigraphy and is part of the study in the evaluation of pulmonary thromboembolism. We wanted to highlight the utilities of Tc-99m MAA other than pulmonary embolism as a pictorial assay. Materials and Methods: Patients referred for Tc-99m MAA scintigraphy under various indications were included in this pictorial essay. Commercially available TechneScan LyoMAA cold kit from Mallinckrodt Medical B.V., Holland was used. Acquisition protocols for different indications are described in this article. Different clinical indications (e.g., pulmonary artery stenosis, hepatopulmonary syndrome, FEV1 calculation in lung surgery planning, selective internal radiation therapy planning, venography for deep venous thrombosis, left to right cardiac shunts, etc.) where Tc-99m MAA scintigraphy was asked for; how it helped in different clinical scenarios and how it can be used clinically is explained with unique and interesting case examples and images. We also reviewed the literature to look for certain remote indications of MAA imaging for the sake of completion like – (shunt scintigraphy, peritoneopleural communication, etc.) Conclusion: Tc-99m MAA is a very useful radiopharmaceutical, which can be used for many other indications apart from the commonly used indication of lung perfusion scan in pulmonary embolism. It can provide useful clinical information in other indications, which we try to highlight in this article. PMID:24250023

  6. Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Application in liver transplantation

    SciTech Connect

    Woodle, E.S.; Ward, R.E.; Vera, D.R.; Stadalnik, R.C.

    1985-05-01

    Tc-NGA is a new liver imaging agent which binds to hepatic binding protein (HBP), a hepatocyte-specific membrane receptor. The purpose of the present study was to evaluate the potential role of Tc-NGA imaging in liver transplantation. The molar Tc-NGA dose was standardized according to patient weight (0.7 nmole/kg). After a 30 minute dynamic imaging study (5 mCi, IV), kinetic analysis of time activity data (heart, liver), provided values for receptor concentration, (HBP), and hepatic blood flow, Q. Eleven Tc-NGA imaging studies were performed in transplant candidates and 22 studies were performed in seven transplant recipients. Preservation damage was manifested by diffuse patchiness in tracer distribution which resolved during the following two weeks. Histologically proven, localized hepatic infarcts were demonstrated in three recipients. Lobar infarction was demonstrated in one recipient. Hepatic regeneration was later demonstrated in this patient after hepatic lobectomy. Hepatic blood flow was markedly decreased in the early postoperative period, but improved with time. Increased (HBP) was demonstrated with regeneration. Markedly decreased (HBP) and Q were obtained in several candidates who died awaiting transplantation. These studies indicate that TC-NGA liver imaging provides a valuable new means for: (1) evaluation of preservation damage, (2) early demonstration of hepatic infarction, (3) evaluation of hepatic rejection, and (4) selection of patients for hepatic transplantation.

  7. High Tc phase of (H2S)2H2 at high pressures

    NASA Astrophysics Data System (ADS)

    Cui, Tian

    2015-03-01

    Hydrogen was predicted to metalize at high pressures and believed to be a room-temperature superconductor. However, metallization of hydrogen is still under debates. As an alternative, hydrogen dominated materials were extensively explored because of their lower metallization pressure. Here I present the high-pressure studies on structures, metallization, and superconductivity of (H2S)2H2 from ab initio calculations. At lower pressures, two phases containing H2 units are stable with P1 (<37 GPa) and Cccm (37-111 GPa) symmetries, which are still insulators. Upon further compression, H2 units disappear and two intriguing metallic structures with R3m and Im-3 m symmetries are reconstructive above 111 GPa and 180 GPa, respectively. Remarkably, the estimated Tc of Im-3 m phase at 200 GPa achieves a very high value of 191 ~ 204 K. Moreover, Tc decreases with pressure at an approximate rate (dTc/dP) of -0.12 K/GPa. Our predicted high Tc and its pressure dependence in Im-3 m phase are subsequently verified by recent experiments. Our findings support the conjecture that hydrogen-rich materials are a way to achieve a metallic phase with high Tc at accessibly experimental pressures and represent a significant step toward the understanding of high-pressure behavior of metallic hydrogen.

  8. Chemical aspects of labeling sucralfate with /sup 99m/TcO/sub 4/

    SciTech Connect

    Billinghurst, M.W.; Abrams, D.N.; Lawson, M.S.

    1989-04-01

    Two formulations of (/sup 99m/Tc)sucralfate have been used to image gastric and duodenal ulcers and inflammatory bowel disease. One formulation is a complexation of (/sup 99m/Tc)HSA with sucralfate. The second is prepared by directly labeling sucralfate with (/sup 99m/Tc)pertechnetate in the presence of stannous ion. An in vitro study of the factors affecting the production and stability of these labeled sucralfate preparations was conducted. Both formulations were stable at the acidic pH likely encountered in the stomach. However, at pH greater than 6 the albumin-sucralfate complex began to dissociate while directly labeled sucralfate was stable to a pH of 9. Conversely it was shown that directly labeled sucralfate was more susceptible to loss of /sup 99m/Tc to other chelating species. Sucralfate complexed with (/sup 99m/Tc)HSA was radiochemically stable up to a specific activity of 26 GBq (700 mCi) per gram while directly labeled sucralfate showed decreased 24-hr stability at specific activities greater than 837 mCi (31 GBq) per gram.

  9. Solvent extraction of [sup 99]Tc from radioactive intermediate liquid waste by dibenzo-18-crown-6.

    SciTech Connect

    Paviet-Hartmann, P. (Patricia)

    2001-01-01

    Technetium is one of the most prominent problems since its most stable specie in the environment, the pertechnetate ion, is highly mobile and considered as a long-term hazard in nuclear waste disposal. Because of the small activities of 99Tc relative to other fission products 137Cso r 90Sr,a nd its long half-life time (t1/2 = 2.1{center_dot}10{sup 5} yrs), 99Tci s one of the key isotopes that should always be analyzed in the radioactive liquid waste streams from the reprocessing industry where the largest concentrations are to be expected. Furthermore, as a pure beta-emitter, Tc has to be isolated from the intermediate level waste (ILW) stream prior to any measurement in such complex media. We have developed a method for 99Tc extraction providing recommendations that will be useful for extracting it from acid and basic ILW. The extraction of 99Tc from L W by dibenzo-18-crown-6 (DB18C6) has been investigated and a simplex optimization of key parameters involved in the procedure has allowed us to set up their best values. Experiments have been carried out on synthetic and real effluents from La Hague reprocessing plant, France, and results show that DB18C6 is highly selective towards 99Tc. The application of this procedure has been successfully demonstrated through the analysis of actual waste streams coming from two reprocessing plants at La Hague and Marcoule, France.

  10. Heat generation in lithium-thionyl chloride and lithium-SO2 cells

    NASA Astrophysics Data System (ADS)

    Cohen, R.; Melman, A.; Livne, N.; Peled, E.

    1992-09-01

    The effects of current density, temperature, depth of discharge (DOD), and storage on the heat generation rate and faradaic efficiency of Li/Tc and Li/SO2 cells have been determined. Several C-size commercial cells from different manufacturers have been tested. The faradaic efficiency for both systems was found to be very high, typically 96-100 percent even at high current density and high temperatures (55 C). It does not change much with DOD and decreases only slightly with the increase of current density and high temperature (tested up to 4.5 mA/sq cm at 50 percent DOD and 55 C). A performance degradation problem was found for some Li/TC cells. The heat factor, the ratio between the useful electric power and the thermal power generated by the cell, is about the same for fresh Li/TC cells and Li/SO2 cells. However, some Li/TC cells stored for 3 years showed a poor heat factor. It was confirmed that the maximum thermoneutral voltage for the Li/TC and Li/SO2 cells is 3.80 and 3.22 V, respectively.

  11. Majority of TcRbeta+ T-lymphocytes located in thymus and midgut of the bony fish, Dicentrarchus labrax (L.).

    PubMed

    Romano, Nicla; Rossi, Francesca; Abelli, Luigi; Caccia, Elisabetta; Piergentili, Rita; Mastrolia, Lucia; Randelli, Elisa; Buonocore, Francesco

    2007-09-01

    Real-time polymerase chain reaction (PCR) and in situ hybridization analyses were performed to investigate the occurrence and distribution of T-lymphocytes expressing TcRbeta in intestine and lymphoid tissues of the bony fish, Dicentrarchus labrax (sea bass). Immunohistochemistry with the monoclonal antibody DLT15 (pan-T-cell marker) was carried out to compare the cytology, distribution and number of T-cells and TcRbeta+ cells in the various sampled lymphoid organs. The highest TcRbeta expression was revealed by real-time PCR in the thymus, with high levels also being found in the gut. In the thymus, DLT15+ and TcRbeta+ cell populations were concentrated in the cortex and TcRbeta+ cells were notably reactive at the cortical-medullary border, suggesting a specialized role of this region in thymocyte selection. The density of DLT15+ T-cells increased from the anterior to posterior intestine, whereas TcRbeta+ lymphocytes were more numerous in the middle intestine compared with other segments. The existence, in fish thymus, of a medulla and a cortex comparable with those of mammals is revealed by this study. The concentration of TcRbeta+ cells in the sea bass midgut also strongly suggests a special role of this intestinal segment in antigen-specific cellular immunity. The large population of TcRbeta(-)/DLT15+ T-cells in the posterior gut can probably be ascribed to the TcRgammadelta phenotype fraction. PMID:17549519

  12. Size Control of (99m)Tc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection.

    PubMed

    Kim, Eun-Mi; Lim, Seok Tae; Sohn, Myung-Hee; Jeong, Hwan-Jeong

    2015-06-01

    Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a (99m)Tc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with (99m)Tc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid ((99m)Tc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid ((99m)Tc-BPTC-50) were chosen for in vitro and in vivo studies. (99m)Tc-BPTC-50 (<20 nm) was primarily located in bone marrow and was then secreted through the kidneys, and (99m)Tc-PPTC-30 (>100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of (99m)Tc-PPTC-30 decreased over time, while (99m)Tc-BPTC-50 increased. Therefore, (99m)Tc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP. PMID:26028937

  13. In Situ and Remote Measurements of Ice Particles in TC4

    NASA Astrophysics Data System (ADS)

    Lawson, P.; Baker, B.; Jensen, E.; Pilson, B.; Mo, Q.; Mitchell, D.; D'Entremont, R.

    2007-12-01

    In situ microphysical measurements using cloud particle imager (CPI) and 2D-S probes were collected on both the NASA DC-8 and WB-57F during the recent TC4 field campaign. Additional data were collected using a CAPS cloud particle probe and other devices that measured cloud particle mass, including a CVI. When appropriate, these measurements are combined or compared in maritime and continental cirrus as a result of outflows from tropical convection near Costa Rica. The results, in terms of particle size distribution, extinction coefficient, optical depth, ice water content, ice water path and particle habit are compared with similar measurements in outflows from continental convection and synoptic cirrus observed over various regions in the United States. Particle shapes observed in the (cirrus) outflows from convection are distinctly different than cirrus formed in situ, whether it is formed at mid-latitudes or in the tropics. Cirrus formed in situ is characterized by ice particles with rosette shapes, whereas the outflow from convection contains mostly irregular shapes, plates and columns. However, once the outflow has aged for several hours, if it encounters regions with high ambient relative humidity (e.g., > 120% with respect to ice), then rosette ice shapes may be generated. Ice particles generated over the ocean do not appear to form "chains" of small ice crystals, such has been observed in strong convection with high electric fields over land. From radiation and modeling perspectives, it appears that particle shapes in synoptic cirrus and convective outflows can be predicted to first order if the life history of the particles is known; i.e., where the ice particles were formed and the history of their exposure to temperature and relative humidity. The issue of small ice crystals is considered in conjunction with a new remote sensing technique for determining the contribution of small ice in cirrus clouds. The principle of photon tunneling in anomalous diffraction theory is applied to the brightness temperature difference (BTD) between 10.8 and 12 microns. Since anomalous diffraction theory predicts an abrupt change in absorption efficiency factor between 10.8 and 12 microns when small ice particles are present, this signal can be used to remotely assess the contribution of small ice. Comparisons between in situ measurements and new 10.8 - 12 micron BTD remote sensing retrieval technique are presented and discussed.

  14. Thermodynamic Model for the Solubility of TcO2•xH2O(am) in the Aqueous Tc(IV) - Na+ - Cl- - H+ - OH- - H2O System

    SciTech Connect

    Hess, Nancy J.; Xia, Yuanxian; Rai, Dhanpat; Conradson, Steven D.

    2004-02-01

    Solubility studies of TcO2•xH2O(am) have been conducted as a function of H+ concentration from 1 x 10-5 to 6 M HCl and as function of chloride concentration from 1 x 10-3 to 5 M NaCl. These experiments were conducted under carefully controlled reducing conditions such that the preponderance of Tc is present in solution is in the reduced oxidation state and was determined to be Tc(IV) by XANES analysis. The aqueous species and solid phases were characterized using a combination of techniques including thermodynamic analyses of solubility data, XRD, and XANES, EXAFS, and UV-Vis spectroscopies. Chloride was found to significantly affect Tc(IV) concentrations through 1) the formation of Tc(IV) chloro complexes [i.e., TcCl4(aq) and TcCl62-] and a stable compound [data suggests this compound to be TcCl4(am)] in highly acidic and relatively concentrated chloride solutions, and 2) its interactions with the positively charged hydrolyzed Tc(IV) species in solutions of relatively low acidity and high chloride concentrations. A thermodynamic model was developed, which included hitherto unavailable chemical potentials of Tc(IV)-chloro species and Pitzer ion-interaction parameters for Tc(IV) hydrolyzed species with bulk electrolyte ions used in this study. The thermodynamic model presented in this paper is consistent with the extensive data reported in this study and with the reliable literature data, and is applicable to a wide range in H+ and Cl- concentrations and ionic strengths.

  15. Energy generator

    SciTech Connect

    Krisko, P.

    1989-08-01

    The patent describes a power booster. It comprises: at least one pendulum means suspended at one end to oscillate about the point of suspension; power generating means; mass means connected to one end of the pendulum means; spring means disposed in operative cooperation with the mass means to impart energy into the pendulum means and assist the pendulum means in oscillating about the point of suspension; and energy transfer linkage means between the pendulum means and the power generating means for transferring energy between the pendulum means and the power generating means.

  16. NMR investigation of iron-selenide and iron-arsenide high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Imai, Takashi

    2012-02-01

    We have investigated the electronic, magnetic, and superconducting properties of the iron-selenide high Tc superconductor KxFe2-ySez (Tc=33 K) with ^77Se NMR [1]. We will compare the results with those observed for FeSe in ambient and applied pressures (Tc>9 K) [2], and with iron-arsenides [3]. Similarities and dissimilarities will be pointed out, with primary focus on the anomalous normal state properties. Our latest work on KxFe2-ySez was carried out in collaboration with D. Torchetti, M. Fu, D. Christensen, K. Nelson (McMaster), H. Lei, and C. Petrovic (Brookhaven National Lab).[4pt] [1] D. Torchetti et al., PR B83, 104508 (2011).[0pt] [2] T. Imai et al. PRL 102, 177005 (2009).[0pt] [3] F.L. Ning et al., PRL 104, 037001 (2010); JPSJ 78, 103711 (2009).

  17. (He-3,d) Reaction to Bound and Quasibound Levels in Tc-93 

    E-print Network

    Kozub, R. L.; Youngblood, David H.

    1971-01-01

    distributions having shapes characteristic of L~ =2 transfers are shown I.O 1.0 O.l IO. E ~? E ci I Ce b MeV = 1.0 eV MeY = LO MeV- I.O eV 0.1 =?? 9 MeV g =I Pp=2 1.0 MeV Mp( He, d) ~Tc 4p = 2 (UN BOUND) Mo( He, d) Tc i)' I- j ~ Q.... W. Nestor, Jr. , T. C. Tucker, and F. B. Malik, Phys. Rev. 169, 27 (1968). PHYSICAL REVIEW C VOLUME 4, NUMBER 2 AUGUST 1971 ( He, d) Reaction to Bound and Quasibound Levels in Tc~ R. L. Kozub and D. H. Youngblood Cyclotron Institute, Texas A 5 M...

  18. Acquiring a novel constitutive equation of a TC6 alloy at high-temperature deformation

    NASA Astrophysics Data System (ADS)

    Li, Miaoquan; Cheng, Shenhui; Xiong, Aiming; Wang, Hairong; Su, Shaobo; Sun, Lichuang

    2005-04-01

    The TC6 alloy produced in Baoji nonferrous metals work, Xian, China, is one of the best titanium alloys with good resistance against heat and corrosion and is widely used in the aviation and aerospace industries. In this paper, isothermal compression tests were conducted on the TC6 alloy in the Thermecmastor Z simulator, at temperatures between 800 and 1040 °C at strain rates between 0.001 and 50 s-1 to a 50% height reduction. The experimental results are presented as variations of flow stress with deformation temperature, strain rate, and strain. On the basis of the present experimental results and deformation behavior, a constitutive equation for the TC6 alloy was proposed by employing an Arrhenius-type equation. The activation energy of deformation (Q) and work-hardening index (n) are found to be a function of strain. The present equation is in good agreement with the experimental data.

  19. Tc-99m galactosyl-neoglycoalbumin: in vitro characterization of receptor-mediated binding

    SciTech Connect

    Vera, D.R.; Krohn, K.A.; Stadalnik, R.C.; Scheibe, P.O.

    1984-07-01

    Hepatic binding protein (HBP) is a membrane receptor that binds and transports plasma glycoproteins from hepatic blood to hepatocellular lysosomes. The authors have characterized the in vitro binding of Tc-99m galactosyl-neoglycoalbumin (Tc-NGA), a synthetic HBP ligand, to liver membrane. Membrane displacement studies, using carrier ligands in contrast to previously bound Tc-NGA or I-NGA, correlated with the binding characteristics of a native HBP ligand, asialo-orosomucoid. They used computer simulation to study the detectibility of the changes in HBP concentration at different values of k/sub b/. The simulations indicated that radiopharmacokinetic sensitivity to alterations in (HBP) should be possible using a neoglycoalbumin preparation with a carbohydrate density within the range of 15 to 25 galactose units per albumin molecule.

  20. False positive GI bleed on Tc-99m RBC scintigraphy due to ileal varices.

    PubMed

    Chen, Paul Ning-Chuan; Brown, Richard Kevin

    2012-02-01

    Tc-99m labeled RBC scintigraphy is commonly employed in the evaluation of acute gastrointestinal bleeding. On Tc-99m RBC studies gastrointestinal bleeding is seen as an initial focus of increased radiotracer activity that on subsequent images increases in intensity and changes position in a pattern that conforms to segments of bowel. We report a case of a patient with multiple episodes of hematochezia that presented with lower gastrointestinal hemorrhage. A Tc-99m labeled RBC scan was performed and the findings suggested a GI bleed. However, subsequent angiography revealed prominent ileal varices simulating an acute bleed. Although most varices fill promptly and should not be misinterpreted as a focus of hemorrhage, slow filling varices can simulate an acute bleed and lead to a false positive interpretation. PMID:22690283

  1. SPECT measurements with /sup 99m/Tc-HM-PAO in focal epilepsy

    SciTech Connect

    Ryding, E.; Rosen, I.; Elmqvist, D.; Ingvar, D.H.

    1988-12-01

    The ability of SPECT measurements with (/sup 99m/Tc)-HM-PAO (Ceretec) to find the location of the epileptic focus was studied in patients under consideration for neurosurgical treatment for therapy-resistant focal epilepsy. The location of low (/sup 99m/Tc)-HM-PAO uptake regions found at interictal measurements, and of high (/sup 99m/Tc)-HM-PAO uptake regions found at ictal measurements, was compared to the findings of extensive ictal and interictal EEG examinations, and to the results of CT and MRT. While EEG revealed focal epileptic activity in all of the 14 patients, SPECT showed regional abnormalities in 13 (93%). CT and MRT showed abnormal findings in 30%.

  2. Chemical Equilibration and Transport Properties of Hadronic Matter near $T_c$

    E-print Network

    J. Noronha-Hostler; J. Noronha; H. Ahmad; I. Shovkovy; C. Greiner

    2009-09-28

    We discuss how the inclusion of Hagedorn states near $T_c$ leads to short chemical equilibration times of proton anti-proton pairs, $K\\bar{K}$ pairs, and $\\Lambda\\bar{\\Lambda}$ pairs, which indicates that hadrons do not need to be "born" into chemical equilibrium in ultrarelativistic heavy ion collisions. We show that the hadron ratios computed within our model match the experimental results at RHIC very well. Furthermore, estimates for $\\eta/s$ near $T_c$ computed within our resonance gas model are comparable to the string theory viscosity bound $\\eta/s=1/4\\pi$. Our model provides a good description of the recent lattice results for the trace anomaly close to $T_c=196$ MeV.

  3. Diagnosis of hepatobiliary disease in infants and children with Tc-99m-diethyl-IDA imaging

    SciTech Connect

    Ohi, R.; Klingensmith, W.C.; Lilly, J.R.

    1981-07-01

    Thirteen infants and children from 42 days to 14 years old with hepatobiliary disease underwent Tc-99m-diethyl-IDA hepatobiliary imaging. Five patients had biliary atresia, four had biliary hypoplasia, two had neonatal hepatitis, and there were single examples of alpha-1-antitrypsin deficiency and congenital hepatic fibrosis. Tc-99m-diethyl-IDA imaging accurately differentiated biliary atresia (complete bile duct obstruction) from other forms of childhood hepatobiliary disease by demonstrating no intestinal radioactivity in the former and the presence of intestinal radioactivity in the latter. In addition, two of four patients with biliary hypoplasia had nonhomogeneous parenchymal transit, and the one patient with congenital hepatic fibrosis showed possible intrahepatic cysts. In conclusion, these preliminary data indicate that Tc-99m-diethyl-IDA provides information not previously available with I-131-rose bengal; this information is likely to be useful in the noninvasive evaluation of childhood hepatobiliary disease.

  4. Abdominal and hepatic uptake of /sup 99m/Tc-pyrophosphate in neonatal necrotizing enterocolitis

    SciTech Connect

    Caride, V.J.; Touloukian, R.J.; Ablow, R.C.; Lange, R.C.; Matthews, T.

    1981-04-01

    Abdominal /sup 99m/Tc-pyrophosphate (/sup 99m/Tc-PYP) scans were obtained in 15 neonates: 12 with neonatal necrotizing enterocolitis (NEC), two with osteomyelitis, and one with myocarditis. Ten of the babies with NEC had at least one positive scan; of these 10 studies, seven (Group A) showed both diffuse abdominal uptake and localized hepatic activity, two (Group B) showed abdominal uptake and questionable hepatic uptake, and one (Group C) demonstrated diffuse abdominal uptake only. The other two babies with NEC had normal scans (Group D). All NEC patients had normal scans. A patient with myocarditis had hepatic uptake of /sup 99m/Tc-PYP while the abdominal scan in the two infants with osteomyelitis was normal. These preliminary observations suggest that further study of a relationship between abdominal scan findings and the course of NEC is warranted.

  5. Photo-production of (99)Mo/(99m)Tc with electron linear accelerator beam.

    PubMed

    Avagyan, R; Avetisyan, A; Kerobyan, I; Dallakyan, R

    2014-09-01

    We report on the development of a relatively new method for the production of (99)Mo/(99m)Tc. The method involves the irradiation of natural molybdenum using high-intensity bremsstrahlung photons from the electron beam of the LUE50 linear electron accelerator located at the Yerevan Physics Institute (YerPhi). The production method has been developed and shown to be successful. The linear electron accelerator at YerPhi was upgraded to allow for significant increases of the beam intensity and spatial density. The LUE50 was also instrumented by a remote control system for ease of operation. We have developed and tested the (99m)Tc extraction from the irradiation of natural MoO3. This paper reports on the optimal conditions of our method of (99)Mo production. We show the success of this method with the production and separation of the first usable amounts of (99m)Tc. PMID:24929962

  6. Generation Wrecked.

    ERIC Educational Resources Information Center

    Watson, Noshua

    2002-01-01

    Young adults in Generation X are facing financial problems. Because of their college and credit card debt, many in worse financial shape than anyone since the Depression and have little or no retirement savings. (JOW)

  7. CGRP 4218T/C polymorphism correlated with postoperative analgesic effect of fentanyl

    PubMed Central

    Yi, Yusheng; Zhao, Mingqiang; Xu, Fenghe; Liu, Chuansheng; Yin, Yanwei; Yu, Junmin

    2015-01-01

    Purpose: Our study aimed at evaluating the association between ?-calcitonin gene-related peptide (CGRP) 4218T/C polymorphism and the patient-controlled analgesic (PCA) effect of fentanyl on Chinese Han population. Methods: 98 patients were involved in the experiment, but only 92 patients completed the experiment. 0.1 mg/kg fentanyl was given to the patients through intravenous injection ten minutes before the ending of surgery. The patients achieved PCA by controlling the fentanyl infusion pump and a single dose was 1 mg. The CGRP 4218T/C polymorphism was genotyped with polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The fentanyl consumption within the 72 hours after the surgery was recorded and the pain was assessed with numeric rating scale (NRS) method. Results: The patients were divided into three groups of wild homozygote (T/T), heterozygote (T/C), and mutant homozygote (C/C). At the 6th hour and the 12th hour after the surgery, the fentanyl consumption for PCA of the T/C group was significantly higher than the T/T group (P<0.05). Meanwhile, the fentanyl consumption of the C/C group was much higher than the T/T group (P<0.05) at the 12th hour and the 24th hour. Besides, the fentanyl consumption of the C/C group was more than the T/C group (P<0.05) at the 24th hour. The differences in NRS scores, Ramsey scores, and postoperative adverse reactions between each group at all time points were not statistically significant. Conclusions: CGRP 4218T/C polymorphism may be associated with the postoperative fentanyl consumption for analgesia. PMID:26191294

  8. Evaluation of 99mTc-LDL for studying lipoprotein metabolism and imaging atherosclerotic lesions in vivo

    SciTech Connect

    Vallabhajosula, S.; Ginsberg, H.N.; Badimon, J.J.; Brown, C.; Lipszyc, H.; Fuster, V.; Goldsmith, S.J.

    1985-05-01

    Radioiodinated low density lipoprotein (LDL) used for studying LDL kinetics is not suitable for nuclear scintigraphy. /sup 99m/Tc-LDL, (Tc-LDL) with ideal physical imaging characteristics is being evaluated for the noninvasive identification of atherosclerotic lesions. LDL was labeled with Tc-99m and purified by gel chromatography (labeling efficiency 28 +- 8%). Human LDL labeled with Tc-99m and I-131 were injected simultaneously into a normal cynomolgus monkey. The plasma decay curves of the two tracers were identical (T1/2:4.5hrs) indicating that Tc-LDL is stable in plasma and is similar to /sup 131/I-LDL. Gamma camera images obtained at 30 min post injection showed that 40% of the activity of both tracers was in the liver. Over the next 4-8 hours, I-131 activity in the liver diminished and appeared in the lower abdomen and thyroid (representing deiodination) while Tc-99m activity in the liver remained stable indicating higher stability of Tc-LDL within hepatocytes. Tc-LDL (rabbit) was injected into normal rabbits and rabbits fed on an atherogenic 0.5% cholesterol diet for 3 months (ATR). 24 hour images showed significant uptake of Tc-LDL in the aorta of ART only. The isolated aorta from ATR showed Tc-LDL uptake in the lesions identified as ''fatty streaks'' by Sudan IV staining. These results suggest that Tc-LDL is stable in vivo and appears to be an efficient agent to identify sites of normal catabolism of LDL as well as uptake of LDL by fatty vascular lesions.

  9. Unusual isotope effects on the pseudogap in high-Tc cuprate superconductors as support for the BCS-like pairing theory of large polarons above Tc

    NASA Astrophysics Data System (ADS)

    Dzhumanov, S.; Baimatov, P. J.; Djumanov, Sh. S.

    2015-06-01

    The BCS-like pairing theory is extended to the intermediate coupling regime and to the cases of exotic cuprate superconductors with large and small Fermi surfaces, so as to describe the pairing correlations above Tc , the opening of a pseudogap (PG) at a mean-field temperature T? >Tc and the unusual isotope effects on the PG in these materials within the large polaron model and two different BCS-like approaches. We argue that unconventional electron-phonon interactions are responsible for the polaron formation and the separation between temperatures T? (the onset of precursor Cooper pairing) and Tc (the onset of the superconducting transition) in exotic cuprate superconductors. Using the extended BCS-like approaches, we calculate the PG formation temperature T? , isotope shifts ?T? , oxygen and copper isotope exponents and show that isotope effects on the PG basically depend on strengths of Coulomb and electron-phonon interactions, doping levels and dielectric constants of the cuprates. The new BCS-like pairing theory of polaronic carriers predicts the existence of small and sizable positive oxygen isotope effect and very large negative oxygen and copper isotope effects on the PG in the cuprates with large Fermi surfaces. The calculated results for T? , isotope shifts and exponents are compared with experimental data on various cuprate superconductors. For all the considered cases, a good quantitative agreement was found between theory and experimental data. We also predict the existence of small and sizable negative isotope effects on T? in deeply underdoped cuprates with small Fermi surfaces. Further, we find that the isotope effects on T? (=Tc) in heavily overdoped cuprates just like in some metals are relatively small positive or become even negative.

  10. P-glycoprotein versus MRP1 on transport kinetics of cationic lipophilic substrates: a comparative study using [99mTc]sestamibi and [99mTc]tetrofosmin.

    PubMed

    Gomes, Célia M F; Abrunhosa, Antero J; Pauwels, Ernest K J; Botelho, M Filomena

    2009-04-01

    The multidrug resistance (MDR) phenotype in cancer is closely related with the overexpression of P-glycoprotein (Pgp) and multidrug resistance protein-1 (MRP1). Although conferring resistance to a similar spectrum of drugs, these proteins present distinct transport mechanisms and have their own substrates. In this work, we compared the functional properties of Pgp and MRP1 in the transport kinetics of two cationic lipophilic tracers, [(99m)Tc]sestamibi and [(99m)Tc]tetrofosmin, in cellular models of resistance. Cellular transport kinetics of both tracers was evaluated in Small-cell lung cancer cell line H69 and in its drug-resistant sublines, H69LX4 and H69AR, overexpressing Pgp and MRP1, respectively. Studies were performed in the absence and in the presence of MDR modulators. Kinetic parameters extracted from time-activity curves were analyzed through receiver-operating characteristics curve analysis. The uptake and the efflux rate of both radiotracers were significantly higher (p < 0.05) in sensitive cells. However, MRP1 was more effective than Pgp in removing tracers from the intracellular medium. The addition of verapamil and PSC833 significantly reduced the efflux rate and restored the accumulation of both tracers in H69LX4 cells. Only verapamil was effective in the inhibition of MRP1; however, the effects were more pronounced with [(99m)Tc]sestamibi, when compared to [(99m)Tc]tetrofosmin. Outward transport of radiotracers by MRP1 was dependent on the intracellular glutathione levels. We concluded that both tracers can detect Pgp- and MRP1-mediated drug resistance, based on transport kinetics; however, MRP1 is more effective than Pgp on outward transport of radiotracers. We postulate that this finding can be useful to distinguish between the two resistance mechanisms. PMID:19409044

  11. Constituents of the Quasiparticle Spectrum Along the Nodal Direction of High-Tc Cuprates

    NASA Astrophysics Data System (ADS)

    Kordyuk, A. A.; Borisenko, S. V.; Zabolotnyy, V. B.; Geck, J.; Knupfer, M.; Fink, J.; Büchner, B.; Lin, C. T.; Keimer, B.; Berger, H.; Pan, A. V.; Komiya, Seiki; Ando, Yoichi

    2006-07-01

    Applying the Kramers-Kronig consistent procedure, developed earlier, we investigate in detail the formation of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. The heavily discussed “70 meV kink” on the renormalized dispersion exhibits a strong temperature and doping dependence when purified from structural effects such as bilayer splitting, diffraction replicas, etc. This dependence is well understood in terms of fermionic and bosonic constituents of the self-energy. The latter follows the evolution of the spin-fluctuation spectrum, emerging below some doping dependent temperature and sharpening below Tc, and is mainly responsible for the formation of the kink in question.

  12. Failure to diagnose cardiac treatment rejection with Tc99m-PYP images.

    PubMed

    McKillop, J H; McDougall, I R; Goris, M L; Mason, J W; Reitz, B A

    1981-08-01

    The possibility of diagnosing transplant rejection using Tc-99m-PYP imaging was examined in 12 cardiac transplant recipients. Two patients were studied on two occasions. The presence or absence of active rejection was established by endomyocardial biopsy. The intensity and pattern of myocardial uptake of the tracer did not differ significantly in the two patients studied at the time of rejection compared to the remainder. It is concluded that a single Tc-99m-PYP study cannot be used to diagnose cardiac transplant rejection. PMID:6266731

  13. Tc-99m-galactosyl-neoglycoalbumin: in vivo characterization of receptor-mediated binding to hepatocyctes

    SciTech Connect

    Vera, D.R.; Krohn, K.A.; Stadalnik, R.C.; Scheibe, P.O.

    1984-04-01

    The biodistribution and kinetics of a receptor-binding hepatic radiopharmaceutical, Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA), were investigated using mammalian and avian models. The radiopharmaceutical exhibited four significant features associated with receptor-mediated binding at the hepatocyte membrane in mammals: (a) high tissue specificity, (b) high molecular specificity, (c) affinity-dependent uptake, and (d) dose-dependent uptake. Diminished hepatic uptake by the avian model illustrated low nonspecific binding. The kinetic sensitivity to ligand-receptor affinity and stoichiometry illustrated the principal feature of receptor-binding radiopharmaceuticals, namely, quantitative assessment of tissue function based upon the biochemical interaction of a ligand and its specific receptor.

  14. Magnetization-Dependent Tc Shift in F/S/F Trilayers with a Strong Ferromagnet

    E-print Network

    Fominov, Yakov

    effect with triplet SC #12;Experimental Geometry I+ I­ V+ V­ 4.3 mm 1.6 mm Ni 7 nm Nb dNb Ni 7 nm FeMn 8(dNb)Ni(8)FeMn(8)Nb(2) #12;M vs. H -1.0 -0.5 0.0 0.5 -3 -2 -1 0 1 2 3 Magnetization(10 -4 emu) Applied FieldNb (nm) Ni(8)Nb(dNb)Ni(8)FeMn(8)Nb(2) #12;Theory of Tc P vs. Tc AP in F/S/F Tagirov, PRL 83, 2058 (1999

  15. 99mTc-HIDA cholescintigraphy in Dubin-Johnson and Rotor syndromes

    SciTech Connect

    Bar-Meir, S.; Baron, J.; Seligson, U.; Gottesfeld, F.; Levy, R.; Gilat, T.

    1982-03-01

    99mTc-HIDA cholescintigraphy was performed in 6 patients with Dubin-Johnson syndrome and 1 patient with Rotor syndrome. In the patients with Dubin-Johnson syndrome, the cholescintigrams had a characteristic pattern of delayed visualization or nonvisualization of the gallbladder and bile ducts in the presence of intense, homogeneous, and prolonged visualization of the liver. In the patient with Rotor syndrome, the hepatobiliary system was not visualized at all. It is concluded that 99mTc-HIDA cholescintigraphy may be helpful in the diagnosis of Dubin-Johnson syndrome and Rotor syndrome and in the differential diagnosis between these two conditions.

  16. /sup 99m/Tc-HIDA cholescintigraphy in Dubin-Johnson and Rotor syndromes

    SciTech Connect

    Bar-Meir (Tel-Aviv Univ., Israel); Baron, J.; Seligson, U.; Gottesfeld, F.; Levy, R.; Gilat, T.

    1982-03-01

    /sup 99m/Tc-HIDA cholescintigraphy was performed in 6 patients with Dubin-Johnson syndrome and 1 patient with Rotor syndrome. In the patients with Dubin-Johnson syndrome, the cholescintigrams had a characteristic pattern of delayed visualization or nonvisualization of the gallbladder and bile ducts in the presence of intense, homogeneous, and prolonged visualization of the liver. In the patient with Rotor syndrome, the hepatobiliary system was not visualized at all. It is concluded that /sup 99m/Tc-HIDA cholescintigraphy may be helpful in the diagnosis of Dubin-Johnson syndrome and Rotor syndrome and in the differential diagnosis between these two conditions.

  17. Corrosive Fretting Wear Behavior of a Titanium Alloy TC11 in Artificial Seawater

    Microsoft Academic Search

    H. Y. Ding; Z. D. Dai; Y. Zhang; G. H. Zhou

    \\u000a By using the ball-on-flat configuration at 30Hz frequency in SRV tribo-tester with various normal loads and amplitudes, the\\u000a corrosive fretting wear behavior of a titanium alloy TC11 flat against a high carbon bearing steel counter ball was investigated\\u000a in artificial seawater and distilled water respectively at room temperature for 1h. The worn surfaces of TC11 were observed\\u000a by scanning electron

  18. Could 99m Tc-glucarate be used to evaluate tumour necrosis?

    Microsoft Academic Search

    Nathalie Perek; Odile Sabido; Nathalie Le Jeune; Nathalie Prevot; Jean-Michel Vergnon; Anthony Clotagatide; Francis Dubois

    2008-01-01

    Purpose  The aim of this study was to determine whether 99mTc-glucarate (99mTc-GLA) is a powerful and discriminant tumour necrosis marker.\\u000a \\u000a \\u000a \\u000a Materials and methods  The induction of apoptosis and secondary necrosis (by a chemotherapeutic agent) and necrosis (by intense hyperthermia) was\\u000a studied on an in vitro and in vivo leukaemic cell line model (U937). The percentage of apoptosis\\/necrosis in vitro was determined\\u000a by

  19. Trypanosoma cruzi TcI and TcII transmission among wild carnivores, small mammals and dogs in a conservation unit and surrounding areas, Brazil.

    PubMed

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; Arrais, Ricardo Corassa; Santos, Jean Pierre; Lima, Valdirene dos Santos; Xavier, Samanta Cristina das Chagas; Cordeir-Estrela, Pedro; D'Andrea, Paulo Sérgio; Jansen, Ana Maria

    2013-02-01

    Aiming to better understand the ecological aspects of Trypanosoma cruzi transmission cycles, wild carnivores, small mammals and dogs were examined for T. cruzi infection in the Serra da Canastra National Park region, Brazil. Isolates were genotyped using mini-exon gene and PCR-RFLP (1f8 and H3) genomic targets. Trypanosoma cruzi transmission was well established in the area and occurred in both wild and peridomestic environments. Dog seroprevalence was 29·4% (63/214) and TcI and TcII genotypes, besides mixed infections were observed. Only TcI was detected in wild mammals. Marsupials displayed lower relative abundance, but a high prevalence of positive haemocultures (4/22), whereas rodents displayed positive haemocultures (9/113) mainly in the abundant Akodon montensis and Cerradomys subflavus species. The felid Leopardus pardalis was the only carnivore to display positive haemoculture and was captured in the same region where the small mammal prevalence of T. cruzi infection was high. Two canid species, Chrysocyon brachyurus and Cerdocyon thous, were serologically positive for T. cruzi infection (4/8 and 8/39, respectively), probably related to their capacity to exploit different ecological niches. Herein, dog infection not only signals T. cruzi transmission but also the genotypes present. Distinct transmission strategies of the T. cruzi genotypes are discussed. PMID:23062278

  20. Sustained neuronal activity generated by glial plasticity

    PubMed Central

    Pirttimaki, Tiina M.; Hall, Stephen D.; Parri, H. Rheinallt

    2011-01-01

    Astrocytes release gliotransmitters, notably glutamate, that can affect neuronal and synaptic activity. In particular, astrocytic glutamate release results in the generation of N-methyl D-aspartate receptor (NMDA-R) mediated slow inward currents (SICs) in neurons. However, factors underlying the emergence of SICs, and their physiological roles are largely unknown. Here we show that, in acute slices of rat somatosensory thalamus, stimulation of Lemniscal or cortical afferents results in a sustained increase of SICs in thalamocortical (TC) neurons that outlasts the duration of the stimulus by an hour. This long term enhancement (LTE) of astrocytic glutamate release is induced by group I metabotropic glutamate receptors (mGluRs), and is dependent on astrocytic intracellular calcium ([Ca2+]i). Neuronal SICs are mediated by extrasynaptic NR2B subunit-containing NMDA-Rs and are capable of eliciting bursts. These are distinct from T-type Ca2+ channel dependent bursts of action potentials, and are synchronized in neighboring TC neurons. These findings describe a previously unrecognized form of excitatory, non-synaptic plasticity in the central nervous system (CNS) that feeds forward to generate local neuronal firing long after stimulus termination. PMID:21613477

  1. {beta}-Decay Half-Lives of Very Neutron-Rich Kr to Tc Isotopes on the Boundary of the r-Process Path: An Indication of Fast r-Matter Flow

    SciTech Connect

    Nishimura, S.; Li, Z.; Watanabe, H.; Kurata-Nishimura, M.; Baba, H.; Doornenbal, P.; Isobe, T.; Sakurai, H.; Scheit, H.; Steppenbeck, D. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Sumikama, T.; Miyashita, Y.; Chiba, J.; Nakano, T.; Sugimoto, K.; Takano, S. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Tachibana, T. [4 Senior High School of Waseda University, Nerima Tokyo 177-0044 (Japan); Yamaguchi, K.; Odahara, A. [Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043 (Japan)

    2011-02-04

    The {beta}-decay half-lives of 38 neutron-rich isotopes from {sub 36}Kr to {sub 43}Tc have been measured; the half-lives of {sup 100}Kr, {sup 103-105}Sr, {sup 106-108}Y, {sup 108-110}Zr, {sup 111,112}Nb, {sup 112-115}Mo, and {sup 116,117}Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A{approx_equal}110 region. A revised model based on the second generation gross theory of {beta} decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted.

  2. ?-decay half-lives of very neutron-rich Kr to Tc isotopes on the boundary of the r-process path: an indication of fast r-matter flow.

    PubMed

    Nishimura, S; Li, Z; Watanabe, H; Yoshinaga, K; Sumikama, T; Tachibana, T; Yamaguchi, K; Kurata-Nishimura, M; Lorusso, G; Miyashita, Y; Odahara, A; Baba, H; Berryman, J S; Blasi, N; Bracco, A; Camera, F; Chiba, J; Doornenbal, P; Go, S; Hashimoto, T; Hayakawa, S; Hinke, C; Ideguchi, E; Isobe, T; Ito, Y; Jenkins, D G; Kawada, Y; Kobayashi, N; Kondo, Y; Krücken, R; Kubono, S; Nakano, T; Ong, H J; Ota, S; Podolyák, Zs; Sakurai, H; Scheit, H; Steiger, K; Steppenbeck, D; Sugimoto, K; Takano, S; Takashima, A; Tajiri, K; Teranishi, T; Wakabayashi, Y; Walker, P M; Wieland, O; Yamaguchi, H

    2011-02-01

    The ?-decay half-lives of 38 neutron-rich isotopes from (36)Kr to (43)Tc have been measured; the half-lives of (100)Kr, (103-105)Sr, (106-108)Y, (108-110)Zr, (111,112)Nb, (112-115)Mo, and (116,117)Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A?110 region. A revised model based on the second generation gross theory of ? decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted. PMID:21405387

  3. BaFe2Se3: A High TC Magnetic Multiferroic with Large Ferrielectric Polarization Shuai Dong,1

    E-print Network

    Tennessee, University of

    and multiferroicity, the search for high TC superconductors (SCs) can help the magnetoelectric (ME) community of their superconducting properties [6]. However, to our knowledge the possibility of multiferroic behavior has not beenBaFe2Se3: A High TC Magnetic Multiferroic with Large Ferrielectric Polarization Shuai Dong,1 J

  4. Novel cyclopentadienyl tricarbonyl (99m)tc complexes containing 1-piperonylpiperazine moiety: potential imaging probes for sigma-1 receptors.

    PubMed

    Wang, Xia; Li, Dan; Deuther-Conrad, Winnie; Lu, Jie; Xie, Ying; Jia, Bing; Cui, Mengchao; Steinbach, Jörg; Brust, Peter; Liu, Boli; Jia, Hongmei

    2014-08-28

    We report the design, synthesis, and evaluation of a series of novel cyclopentadienyl tricarbonyl (99m)Tc complexes as potent ?1 receptor radioligands. Rhenium compounds 3-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)propylcarbonylcyclopentadienyl tricarbonyl rhenium (10a) and 4-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)butylcarbonylcyclopentadienyl tricarbonyl rhenium (10b) possessed high in vitro affinity for ?1 receptors and moderate to high selectivity for ?2 receptors and the vesicular acetylcholine transporter. Biodistribution studies in mice demonstrated high initial brain uptake for corresponding (99m)Tc derivatives [(99m)Tc]23 and [(99m)Tc]24 of 2.94 and 2.13% injected dose (ID)/g, respectively, at 2 min postinjection. Pretreatment of haloperidol significantly reduced the radiotracer accumulation of [(99m)Tc]23 or [(99m)Tc]24 in the brain. Studies of the cellular uptake of [(99m)Tc]23 in C6 and DU145 tumor cells demonstrated a reduction of accumulation by incubation with haloperidol, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine (SA4503), or 1,3-di-o-tolyl-guanidine (DTG). Furthermore, blocking studies in C6 glioma-bearing mice confirmed the specific binding of [(99m)Tc]23 to ?1 receptors in the tumor. PMID:25073047

  5. On the MAX\\/TC criterion for code acquisition and its application to DS-SSMA systems

    Microsoft Academic Search

    Giovanni Emanuele Corazza

    1996-01-01

    We analyze in depth the MAX\\/TC criterion for code acquisition in spread-spectrum transmissions. The uncertainty region is divided into sectors: inside each sector, the cell with associated maximum test variable is selected (MAX criterion), and sectors are serially tested according to the threshold crossing (TC) criterion. The most commonly used analysis tools for code acquisition, namely the direct and the

  6. Antilymphocyte autoantibodies generate T cell-C4d signatures in systemic lupus erythematosus.

    PubMed

    Liu, Chau-Ching; Manzi, Susan; Ahearn, Joseph M

    2014-12-01

    T cells bearing C4d, a complement activation product (CAP), have been shown to be highly sensitive and specific as diagnostic biomarkers for systemic lupus erythematosus (SLE). T cells bearing C4d are also functionally abnormal, suggesting a role for cell-bound CAPs in lupus pathogenesis. However, the mechanism responsible for generation of T-C4d has not been determined. The purpose of this cross-sectional and prospective study was to investigate the potential role of anti-T-cell autoantibodies in the generation of the T cell-bound C4d (T-C4d) signatures in SLE. Briefly, T cells from patients with SLE (n = 326), patients with other inflammatory diseases (n = 185), and healthy controls (n = 48) were characterized for surface deposition of either or both of C4d and immunoglobulin (Ig) by flow cytometry. In vitro phenotype transfer experiments were performed to characterize Ig from patients with SLE for the capacity to generate T-C4d signatures in vitro. The results demonstrate that individual patients with SLE harbor specific signatures reflecting the presence of either or both of C4d and Ig on their T cells and T-cell subsets. In addition, SLE patient-specific signatures can be transferred in vitro to normal T cells by exposure to Ig purified from the signature donor. Complement activation does not proceed through the generation of C5b-9 (membrane attack complex) or cellular lysis, and T-C4d does not correlate with lymphopenia. In conclusion, these results suggest that patient-specific T-C4d signatures are generated by anti-T-cell autoantibodies that trigger sublytic complement activation, a previously unrecognized pathway in lupus pathogenesis. PMID:25168018

  7. Detection of gastrointestinal blood loss with 99mTc-labeled, heat-treated red blood cells. [Dogs

    SciTech Connect

    Som, P.; Oster, Z.H. Atkins, H.L.; Goldman, A.G.; Sacker, D.F.; Harold, W.H.; Fairchild, R.G.; Richards, P.; Brill, A.B.

    1981-01-01

    Studies in dogs showed that heat-treated 99mTc-labeled red blood cells (HT/RBC) afford a highly sensitive means of detecting gastrointetinal bleeding as low as 0.12 ml/min., which could not be seen with unheated 99mTc-RBC, 99mTc-sulfur colloid, or 99mTc-DTPA. In addition, as the right upper quadrant and epigastrium remained free of activity, only one fifth to one tenth of the dose of 99mTc was needed. The safety of HT/RBC in humans has been documented, and the experiments in dogs suggest that it may have advantages over other agents in detecting gastrointestinal bleeding.

  8. Detection of gastrointestinal blood loss with /sup 99m/Tc-labeled, heat-treated red blood cells

    SciTech Connect

    Som, P. (Brookhaven National Lab., Upton, NY); Oster, Z.H.; Atkins, H.L.; Goldman, A.G.; Sacker, D.F.; Harold, W.H.; Fairchild, R.G.; Richards, P.; Brill, A.B.

    1981-01-01

    Studies in dogs showed that heat-treated /sup 99m/Tc-labeled red blood cells (HT/RBC) afford a highly sensitive means of detecting gastrointestinal bleeding as low as 0.12 ml/min, which could not be seen with unheated /sup 99m/Tc-RBC, /sup 99m/Tc-sulfur colloid, or /sup 99m/Tc-DTPA. In addition, as the right upper quadrant and epigastrium remained free of activity, only one fifth to one tenth of the dose of /sup 99m/Tc was needed. The safety of HT/RBC in humans has been documented, and the experiments in dogs suggest that it may have advantages over other agents in detecting gastrointestinal bleeding.

  9. Solar Generator

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The Vanguard I dish-Stirling module program, initiated in 1982, produced the Vanguard I module, a commercial prototype erected by the Advanco Corporation. The module, which automatically tracks the sun, combines JPL mirrored concentrator technology, an advanced Stirling Solar II engine/generator, a low cost microprocessor-controlled parabolic dish. Vanguard I has a 28% sunlight to electricity conversion efficiency. If tests continue to prove the system effective, Advanco will construct a generating plant to sell electricity to local utilities. An agreement has also been signed with McDonnell Douglas to manufacture a similar module.

  10. Interplay of 3 d-5 d interactions in high-TC osmium-based double perovskites

    NASA Astrophysics Data System (ADS)

    Taylor, A. E.; Calder, S.; Morrow, R.; Woodward, P. M.; Yan, J. Q.; Winn, B.; Lumsden, M. D.; Christianson, A. D.

    2015-03-01

    In 3d-5d systems the strongly magnetic 3d orbitals and extended 5d orbitals with enhanced spin-orbit coupling lead to a range of high TC magnetic states and novel behavior not present in systems consisting solely of 3d or 5d ions. The two distinct octahedral sites in double perovskites A2 BB 'O6 allow an ordered 3d-5d structure to form, providing a variety of systems to be investigated. Unravelling the interactions controlling these systems, however, is an open challenge. The highest known TC in such a system, 725K, is found in insulator Sr2CrOsO6. This questions the theory for high-TCs in systems such as TC=400K Sr2FeReO6 which relies on half-metallic behavior. To unravel the nature of the interactions in 3d-5d systems, we have studied the series of compounds Sr2 X OsO6. We have utilized elastic and inelastic neutron scattering to probe the spin states in the systems, and therefore test predictions that the magnetic interactions are controlled by a frustrated AFM Heisenberg model. By studying the series, we are able to relate changes in the spin wave spectrum to dramatic changes in the magnetic order from TN = 95 K antiferromagnetism to TC = 725 K ferrimagnetism.

  11. A comparison of tc and tp for magnitude estimation in earthquake

    E-print Network

    Wu, Yih-Min

    A comparison of tc and tp max for magnitude estimation in earthquake early warning Jang-Tian Shieh-NET strong motion records of 16 earthquakes in Japan with moment magnitude (Mw) ranging from 6.0 to 8.3. A 0 in magnitude determination. Our results show that using two poles in the filters results in the best magnitude

  12. Ulcerative colitis and a bleeding polyp detected on Tc-99m-pertechnetate abdominal scintigraphy

    SciTech Connect

    Howman-Giles, R.

    1981-10-01

    Two children with rectal bleeding were diagnosed as having ulcerative colitis and a bleeding colonic polyp respectively using abdominal scanning with Tc-99m pertechnetate. Early flow studies are recommended with careful attention paid to the amount of time abnormal areas of activity are seen on the abdominal scan.

  13. Contactless measurement of the transition temperature for large area high Tc films

    Microsoft Academic Search

    J. G. Fang; Y. C. Yang; Wenwei Mao; Z. Gao; M. L. Liu

    1994-01-01

    The noncontact electromagnetic induction method for measuring the transition temperature of large area high Tc films is described. This technique rely on the variation of the mutual inductance between two coils. Our designed system can detect the large area samples which diameter more than 10 mm. In addition, the apparatus can measure many positions on same sample simultaneously by a

  14. Acute subendocardial infarction with diffuse intense Tc-99m PYP uptake and minimal Tl-201 abnormality.

    PubMed

    Taki, J; Taki, S; Ichiyanagi, K; Akashi, Y; Hisada, K

    1992-08-01

    Tc-99m PYP scintigraphy performed on a patient with severe anterior chest pain showed diffuse intense uptake with central decreased activity corresponding to the left ventricular cavity. Tl-201 myocardial perfusion scintigraphy at rest revealed a minimal perfusion abnormality with decreased apical uptake in the lateral view. Because of these findings, diffuse subendocardial infarction was suggested. PMID:1387053

  15. [A case of stunned myocardium with marked 99mTc-PYP accumulation].

    PubMed

    Aoki, T; Nishikawa, H; Motoyasu, M; Shimizu, Y; Fukui, A; Ono, N; Kakuta, Y; Konishi, T; Nakano, T

    1993-01-01

    A 71-year-old woman with unstable angina was admitted to our department. Upon admission, electrocardiography revealed a QS pattern in Leads V1-V3. Left ventriculography disclosed akinesis of the anterior wall and the septum. Myocardial scintigraphy with 99mTc-pyrophosphate (PYP) revealed marked accumulation (Parkey's grade III) in the anterior wall, septum and apical region. Coronary arteriography revealed stenosis (99% with delay) in the LAD #6. Based on these findings, we performed percutaneous transluminal coronary angioplasty (PTCA) on this patient. About 3 months later, the patient underwent PTCA again because stenosis had recurred. The resting 201Tl myocardial scintigram, taken immediately after the first PTCA, demonstrated complete defects in the anterior wall, septum and apical region. After the second PTCA, no stenosis was observed. About 1 year later, the wall motion returned to normal (except in part of the apical region), suggesting that this was a case of stunned myocardium. On the same occasion, the 201Tl uptake was normal except in the apical region. The present case was regarded as stunned myocardium which demonstrated marked radioactivity accumulation when examined by 99mTc-PYP myocardial scintigraphy. In the past, 99mTc-PYP has been thought to be incorporated into irreversibly impaired myocardium (e.g., in cases of acute myocardial infarction). The uptake of 99mTc-PYP into stunned myocardium has not been reported before. Thus, this case is rare and noteworthy. PMID:8455342

  16. Differential concentration of Technetium-99 (99Tc) in common intertidal molluscs with different food habits.

    PubMed

    Sjøtun, K; Heldal, H E; Brakstad, D S

    2011-11-01

    Concentration of 99Tc has been measured in fucoids and molluscs, sampled in a sheltered intertidal at the southwest coast of Norway from February to November 2006. The concentrations of 99Tc in molluscs differed significantly between species. The filtering bivalve Mytilus edulis had the lowest concentrations with averages of 2.3-5.9 Bq kg(-1) d.w., while the herbivorous gastropods Littorinalittorina, Littorina obtusata and Patella vulgata had higher concentrations. P. vulgata and L. obtusata had the highest concentrations, 40-47 and 26-30 Bq kg(-1)d.w., respectively. L. obtusata has a specialized habit of living, and prefers to feed on fucoids. P. vulgata can graze extensively on the fucoid Ascophyllum nodosum when available. Fucoids are known to have very high uptake of 99Tc, and this was also found in the present study. The high 99Tc-concentrations of L. obtusata and P. vulgata are most likely due to their habit of feeding on fucoids. PMID:21925686

  17. Measurement of pulmonary epithelial permeability with /sup 99m/Tc-DTPA aerosol

    SciTech Connect

    Coates, G.; O'Brodovich, H.

    1986-10-01

    The rate at which inhaled aerosol of /sup 99m/Tc-diethylenetriamine pentaacetate (DTPA) leaves the lung by diffusion into the vascular space can be measured with a gamma camera or simple probe. In normal humans, /sup 99m/Tc-DTPA clears from the lung with a half time of about 80 minutes. Many acute and chronic conditions that alter the integrity of the pulmonary epithelium cause an increased clearance rate. Thus cigarette smoking, alveolitis from a variety of causes, adult respiratory distress syndrome (ARDS), and hyaline membrane disease (HMD) in the infant have all been shown to be associated with rapid pulmonary clearance of /sup 99m/Tc-DTPA. Rapid clearance is also promoted by increased lung volume and decreased surfactant activity. Although the mechanism of increased clearance in pathological states is not known, the /sup 99m/Tc-DTPA lung-clearance technique has great potential clinically, particularly in patients at risk from ARDS and HMD and in the diagnosis and follow-up of alveolitis. 58 references.

  18. MYELOID NEOPLASIA Perturbed hematopoiesis in the Tc1 mouse model of Down syndrome

    E-print Network

    Li, Zhe

    mutation in GATA1 resulting in exclusive synthesis of a truncated protein (GATA1s), suggest- ing that both trisomy 21 and GATA1 muta- tions are required for leukemogenesis. To gain further understanding of how Hsa- matopoiesis. Introduction of GATA1s into Tc1 mice resulted in a synergistic in- crease in megakaryopoiesis

  19. Measurement of Tc suppression in tungsten using magnetic impurities B. A. Younga)

    E-print Network

    California at Berkeley, University of

    parameters and specific vacuum chamber condi- tions. The variability in Tc from one batch of devices quantities of various residual impurities present in our vacuum chamber during deposition. Because film interacting massive particle WIMP dark matter rely on collecting thermal phonons using overlapping thin films

  20. Current sensing noise thermometry using a low Tc DC SQUID preamplifier

    Microsoft Academic Search

    C. P. Lusher; Junyun Li; V. A. Maidanov; M. E. Digby; H. Dyball; A. Casey; J. Nyéki; V. V. Dmitriev; B. P. Cowan; J. Saunders

    2001-01-01

    We describe here the design and performance of a current sensing noise thermometer using a low Tc DC SQUID as the front end amplifier. The DC SQUID is used to measure the thermal noise current in a resistor and the temperature is then obtained from the Nyquist formula. The thermometer is fast, absolute and precise and is usable over a

  1. Complete genome sequence of Alicyclobacillus acidocaldarius strain Tc-4-1.

    PubMed

    Chen, Yaping; He, Yongzhi; Zhang, Bing; Yang, Jin; Li, Wenjie; Dong, Zhiyang; Hu, Songnian

    2011-10-01

    Alicyclobacillus acidocaldarius strain Tc-4-1 was initially isolated from a hot spring in Tengchong, China. This organism is both thermophilic and acidophilic. It can produce heat- and acid-stable enzymes, such as amylase and esterase, which may be important in industry. Here we report the whole genome sequence of the strain. PMID:21914900

  2. Complete Genome Sequence of Alicyclobacillus acidocaldarius Strain Tc-4-1

    PubMed Central

    Chen, Yaping; He, Yongzhi; Zhang, Bing; Yang, Jin; Li, Wenjie; Dong, Zhiyang; Hu, Songnian

    2011-01-01

    Alicyclobacillus acidocaldarius strain Tc-4-1 was initially isolated from a hot spring in Tengchong, China. This organism is both thermophilic and acidophilic. It can produce heat- and acid-stable enzymes, such as amylase and esterase, which may be important in industry. Here we report the whole genome sequence of the strain. PMID:21914900

  3. Text classification Naive Bayes NB theory Evaluation of TC Web Search and Text Mining

    E-print Network

    Gray, Alexander

    Text classification Naive Bayes NB theory Evaluation of TC Web Search and Text Mining http://www.cc.gatech.edu/~agray/6240spr11 IIR 13: Text Classification & Naive Bayes Alexander Gray Georgia Institute of Technology, College of Computing 2011 Gray: Text Classification & Naive Bayes 1 / 52 #12;Text classification Naive

  4. Optimizing Cr(VI) and Tc(VII) remediation through nano-scale biomineral engineering

    E-print Network

    Cutting, R. S.

    2010-01-01

    in order to reduce 1 equivalent of Cr(VI), and that theCr(VI) and Tc(VII) when compared to inorganic equivalents.Cr(VI) that should have been reduced by the ferrihydrite-derived magnetite suspension is equivalent

  5. SYMPOSIUM PAPER TC7.1 -DOMESTIC REFRIGERATORS AND FOOD FREEZERS

    E-print Network

    Oak Ridge National Laboratory

    #12;SYMPOSIUM PAPER FOR TC7.1 - DOMESTIC REFRIGERATORS AND FOOD FREEZERS THE ENGINEERING) Freezer Compartment Fresh Food Compartment Side 3.00 Side 2.25 Front 2.50 Front 2.50 Back 3.00 Back 2 & door hardware) Overall Depth: 33(including " " " " ) Adjusted Volume (ft3) Freezer 4.39 Fresh Food 13

  6. Characteristics of Model Windings of High-TC Superconducting Transformer for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Kamijo, H.; Hata, H.; Fujimoto, H.; Bohno, T.; Sakaki, K.; Yamada, H.; Iwakuma, M.; Funaki, K.

    2004-06-01

    We investigated the possibility of applying high-TC superconducting traction transformer to a rolling stock. In order to achieve a lightweight design, the traction transformer needs to have a special winding structure unlike the experimental high-TC superconducting power transformers fabricated so far. The windings of the traction transformer need to be arranged as closely as possible in a high magnetic field. Then, we fabricated two high-TC superconducting coils that simulated the winding of a high-TC superconducting traction transformer. One is a multi-layer solenoid coil that simulated the primary winding of the transformer. This coil has five layers of a single Bi2Sr2Ca2Cu3Ox (Bi2223) superconducting tape. The other is a close solenoid coil that simulated the secondary winding of the transformer. This coil has one layer of eight parallel Bi2223 superconducting tapes. In this study, we measured the voltage-current, AC loss, current sharing and over current characteristics of these coils cooled by saturated and subcooled liquid nitrogen.

  7. Arthrobacter aurescens TC1 Metabolizes Diverse s-Triazine Ring Compounds

    PubMed Central

    Strong, Lisa C.; Rosendahl, Charlotte; Johnson, Gilbert; Sadowsky, Michael J.; Wackett, Lawrence P.

    2002-01-01

    Arthrobacter aurescens strain TC1 was isolated without enrichment by plating atrazine-contaminated soil directly onto atrazine-clearing plates. A. aurescens TC1 grew in liquid medium with atrazine as the sole source of nitrogen, carbon, and energy, consuming up to 3,000 mg of atrazine per liter. A. aurescens TC1 is metabolically diverse and grew on a wider range of s-triazine compounds than any bacterium previously characterized. The 23 s-triazine substrates serving as the sole nitrogen source included the herbicides ametryn, atratone, cyanazine, prometryn, and simazine. Moreover, atrazine substrate analogs containing fluorine, mercaptan, and cyano groups in place of the chlorine substituent were also growth substrates. Analogs containing hydrogen, azido, and amino functionalities in place of chlorine were not growth substrates. A. aurescens TC1 also metabolized compounds containing chlorine plus N-ethyl, N-propyl, N-butyl, N-s-butyl, N-isobutyl, or N-t-butyl substituents on the s-triazine ring. Atrazine was metabolized to alkylamines and cyanuric acid, the latter accumulating stoichiometrically. Ethylamine and isopropylamine each served as the source of carbon and nitrogen for growth. PCR experiments identified genes with high sequence identity to atzB and atzC, but not to atzA, from Pseudomonas sp. strain ADP. PMID:12450818

  8. arXiv:cond-mat/0103255v112Mar2001 Why high Tc is exciting.

    E-print Network

    Zaanen, Jan

    in transition metal oxides, especially so in the copper-oxide (high Tc) superconductors. Here I will present everything. Also in modern fields like mesoscopic- and nano physics it is taken as the omnipotent physical be completely neglected? In conventional systems, like copper wire, silicon chips and neutron stars, the answer

  9. Iron Arsenides--The New Family of High TC Magnetic Superconductors

    E-print Network

    Weston, Ken

    (Superconductivity) = 35 K · T(Gd) = 2.5 K · J. W. Lynn, B. Keimer, C. Ulrich, C. Bernhard, and J. L. Tallon, Phys. Rev. B61, 14964 (2000) #12;Cuprate (High TC) Superconductors #12;Single Layer Double Layer Nd2CuO4La2CuO4

  10. Optimal Geometry in Nature, Art, and Mathematics TC 310: Modes of Reasoning --Unique Number 42970

    E-print Network

    Knopf, Dan

    Optimal Geometry in Nature, Art, and Mathematics TC 310: Modes of Reasoning -- Unique Number 42970. The hexagonal packing system used by bees in their honeycombs is the most efficient (least perimeter) way: mathematics provides tools by which we can find rigorous meaning in what might otherwise be fuzzy concepts

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

    SciTech Connect

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

    1982-11-01

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

  12. TcRho1, a Farnesylated Rho Family Homologue from Trypanosoma cruzi

    E-print Network

    Gelb, Michael

    TcRho1, a Farnesylated Rho Family Homologue from Trypanosoma cruzi CLONING, TRANS. We report the molecular identification in trypanosomatids (Trypano- soma cruzi) of the first member Q-Sepharose chromatography frac- tions from T. cruzi cytosol, was shown to be efficiently

  13. The effect of average A-site cation radius on TC in perovskite manganites

    NASA Astrophysics Data System (ADS)

    Wang, Z. M.; Ni, G.; Sang, H.; Du, Y. W.

    2001-09-01

    Three series of samples Ln 0.7T 0.3MnO 3 (I), Ln 0.7T 0.3Mn 0.9Cr 0.1O 3 (II), and Ln 0.7T 0.3Mn 0.9Fe 0.1O 3 (III) (Ln=La, (La, Nd), (La, Y), T=Ca, CaSr, Sr) were prepared by sol-gel technique. The effect of the average A-site cation radius < rA> on the ferromagnetic transition temperature TC has been investigated. TC was obtained from M- T curves measured by vibrating sample magnetometer. For a little Nd 3+ doped at the A-site, the TC of Ln 0.7T 0.3MnO 3 (I) drops linearly with decreasing < rA> (1.18 Å<< rA><1.25 Å). Similar behavior has been observed in series II and III, which have lower TC values than series I due to the weakening of the influence of double-exchange interactions upon substituting Fe and Cr for Mn.

  14. Synthesis of a 99mTc Flutamide System for Imaging Androgen Expression in

    E-print Network

    Collins, Gary S.

    Synthesis of a 99mTc Flutamide System for Imaging Androgen Expression in Prostate Cancer K. Tace Rand, Adam Moore, Paul Benny Washington State University, Department of Chemistry, Pullman, WA 99164 ReceptorFlutamide Structural design of targeted radiopharmaceuticals #12;

  15. Crystal growth of a high-Tc SmBCO superconductor in 1 atm oxygen pressure

    NASA Astrophysics Data System (ADS)

    Cai, Y. Q.; Yao, X.; Hu, A.; Wu, X. J.; Jirsa, M.; Xu, S.; Jin, G.

    2006-07-01

    Sm1+xBa2-xCu3Oz (SmBCOss) single crystals with Tc = 95 K and a sharp transition were grown by top-seeded solution growth in 1 atm oxygen pressure. Compositional analysis by the inductively coupled plasma (ICP) technique and Tc measurement with a superconducting quantum interference device (SQUID) indicate that a nearly stoichiometric SmBCO phase with a high Tc value can be reached in a rather wide range of liquid compositions and oxygen partial pressures. Specific features of the SmBCO system phase diagram were elucidated that explain why the SmBCO single crystals grow more easily than YBa2Cu3Oz (YBCO) or Nd1+xBa2-xCu3Oz (NdBCO) ones. The surface morphology of nanostripes was investigated by atomic force microscopy (AFM). The nanostripes were thought to act as an effective pinning medium, due to the comparable scale with the vortex core. Furthermore, two SmBCO samples with typical Tc values were analysed by energy-dispersive spectroscopy (EDS) and the composition fluctuations along their stripes were studied.

  16. Green functions in t-J model of high-[Tc] superconductivity

    SciTech Connect

    Nguyen, V.H. (National Centre for Natural Science and Technology, Hanoi (Viet Nam))

    1994-10-10

    The explicit expressions of the imaginary time normal and anomalous two-point Green functions in the t-J model of high-[Tc] superconductivity without the single occupation constraint as well as those of the real time ones at a finite temperature are derived in the mean field approximation. The possible applications of these results are outlined.

  17. TC10 controls human myofibril organization and is activated by the sarcomeric RhoGEF obscurin.

    E-print Network

    Boyer, Edmond

    a novel signaling pathway in human skeletal muscle that involves obscurin and the Rho GTPase TC10 and skeletal muscle, but also on a continuous basis during the physiological turnover of muscle. The thousands). In cardiac myocytes and muscle cell lines, the suppression of titin expression was associated

  18. Abnormal Tc-99m-MDP/GA-67 scan patterns in association with active chronic osteomyelitis

    SciTech Connect

    Tumeh, S.S.; Aliabadi, P.; Weissman, B.; McNeil, B.J.

    1985-05-01

    In this study the authors reviewed data from 136 patients (pts) in order to refine the interpretive criteria used to diagnose active osteomyelitis (AOM) in patients with previous bone disease (e.g., old osteomyelitis, fractures, orthopedic devices excluding prostheses). They evaluated bone (Tc-99mMDP) and gallium 67 studies and obtained followup in all pts. AOM was diagnosed by surgery or biopsy and culture in 49 pts and was excluded by the same criteria in 16 pts. An additional 71 pts had the diagnosis excluded by followup clinical criteria. Five patterns were found. T1: abnormal Tc-99m-MDP, normal Ga-67. T2: diffuse increased uptake of both radiopharmaceuticals with Tc-99m-MDP greater than Ga-67. T3: different geographic distribution, but similar intensities of uptake of both. T4: very similar uptake and distribution of both. T5: Ga-67 exceeded Tc-99m-MDP. The authors conclude that T5 is diagnostic of AOM, T3 and T4 raise the probability of AOM than before scanning, T1 and T2 decrease it.

  19. /sup 99m/Tc-methylene diphosphonate accumulation in ascitic fluid due to neoplasm

    SciTech Connect

    Gordon, L.; Schabel, S.I.; Holland, R.D.; Cooper, J.F.

    1981-06-01

    /sup 99m/Tc-methylene diphosphonate (MDP) was found to accumulate in the abdomen in 7 patients with ascites due to a primary tumor of the ovary, testis, stomach, or urethra, leukemia, or lymphoma. This finding should strongly suggest malignancy.

  20. Current Outlook for 99mTc Distribution Based on Electron Accelerator Production

    SciTech Connect

    Benjamin L. Nelson; W. David Bence; John R. Snyder

    2007-07-01

    In 1999 a practical example illustrating the economical and reliable production of 99mTc from an accelerator was developed. It included the realistic costs involved in establishing and operating the accelerator facility and the distribution of the 99mTc to regions in Florida. However, the technology was never commercialized. Recent political and economic developments prompted this second look at accelerator produced 99mTc. The practicality of this system in 2007 dollars was established to account for inflation and current demand. The same distribution model and production schedule from the Global ‘99 study were used. Numbers were found using current rates and costs where possible and indexed estimations when necessary. Though several of the costs increased significantly and the sale price remains at approximately 35¢/mCi, the unit cost of 99mTc throughput only increased from 12.8¢/mCi to 15.0¢/mCi or approximately 17.2% from 1999 to 2007 thus continuing to be economically viable. This study provides ground work for creating business development models at additional locations within the U.S.

  1. Trypanosoma cruzi strain TcI is associated with chronic Chagas disease in the Brazilian Amazon

    PubMed Central

    2014-01-01

    Background Chagas disease in the Amazon region is considered an emerging anthropozoonosis with a predominance of the discrete typing units (DTUs) TcI and TcIV. These DTUs are responsible for cases of acute disease associated with oral transmission. Chronic disease cases have been detected through serological surveys. However, the mode of transmission could not be determined, or any association of chronic disease with a specific T. cruzi DTU’s. The aim of this study was to characterize Trypanosoma cruzi in patients with chronic Chagas disease in the State of Amazonas, Brazil. Methods Blood culture and xenodiagnosis were performed in 36 patients with positive serology for Chagas disease who participated in a serological survey performed in urban and rural areas of Manaus, Amazonas. DNA samples were extracted from the feces of triatomines used for xenodiagnosis, and the nontranscribed spacer of the mini-exon gene and the mitochondrial gene cytochrome oxidase subunit II (COII) were amplified by PCR and sequenced. Results Blood culture and xenodiagnosis were negative in 100% of samples; however, molecular techniques revealed that in 13 out of 36 (36%) fecal samples from xenodiagnosis, T. cruzi was characterized as the DTU TcI, and different haplotypes were identified within the same DTU. Conclusion The DTU TcI, which is mainly associated with acute cases of Chagas disease in the Amazon region, is also responsible for chronic infection in patients from a region in the State of Amazonas. PMID:24916362

  2. New method for the selective labeling of erythrocytes in whole blood with Tc-99m

    DOEpatents

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1984-01-27

    Method and kit are described for the preparation of /sup 99m/Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for the reduction of technetium.

  3. Kit for the selective labeling of red blood cells in whole blood with [sup 99]Tc

    DOEpatents

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1992-05-26

    Disclosed herein are a method and kit for the preparation of [sup 99m]Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium. No Drawings

  4. Kit for the selective labeling of red blood cells in whole blood with .sup.9 TC

    DOEpatents

    Srivastava, Suresh C. (Setauket, NY); Babich, John W. (Redhill Surrey, GB2); Straub, Rita (Brookhaven, NY); Richards, Powell (New Bern, NC)

    1992-01-01

    Disclosed herein are a method and kit for the preparation of .sup.99m Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium.

  5. Role of 99mTc-ECD SPECT in the Management of Children with Craniosynostosis

    PubMed Central

    Barik, Mayadhar; Bajpai, Minu; Das, Rashmi Ranajn; Malhotra, Arun; Panda, Shasanka Shekhar; Sahoo, Manas Kumar; Dwivedi, Sadanand

    2014-01-01

    Purpose of the Report. There is a paucity of data on correlation of various imaging modalities with clinical findings in craniosynostosis. Moreover, no study has specifically reported the role of 99mTc-ECD SPECT in a large number of subjects with craniosynostosis. Materials and Methods. We prospectively analyzed a cohort of 85 patients with craniosynostosis from year 2007 to 2012. All patients underwent evaluation with 99mTc-ECD SPECT and the results were correlated with radiological and surgical findings. Results. 99mTc-ECD SPECT revealed regional perfusion abnormalities in the cerebral hemisphere corresponding to the fused sutures preoperatively that disappeared postoperatively in all the cases. Corresponding to this, the mean mental performance quotient (MPQ) increased significantly (P?Tc-ECD SPECT study) are beneficial, as theylead to improved MPQ after surgery. PMID:24987670

  6. A Rice Tc1/Mariner-Like Element Transposes in Yeast Guojun Yang,a Clifford F. Weil,b and Susan R. Wesslera,1

    E-print Network

    Wessler, Susan

    identified. Nearly identical copies of a rice (Oryza sativa) Tc1/mariner element called Osmar5 in the genome plant Tc1/mariner elements were identified from soybean (Glycine max) (Soymar1) and rice (Oryza sativa

  7. Detection of pulmonary metastases with the novel radiolabeled molecular probe, 99mTc-RRL

    PubMed Central

    Yao, Ning; Yan, Ping; Wang, Rong-Fu; Zhang, Chun-Li; Ma, Chao; Chen, Xue-Qi; Zhao, Qian; Hao, Pan

    2015-01-01

    Background: To improve the detection of pulmonary metastases, experimental blood-borne pulmonary metastasis mouse models were established using three intravenously administered cell lines. In a previous study we demonstrated that 99mTc-radiolabeled arginine-arginine-leucine (RRL) could be used to non-invasively image malignant tumors. Methods: 99mTc-RRL was prepared and injected intravenously in mice with pulmonary metastases that arose from the intravenous injection of HepG2, B16, and Hela cells. The bio-distribution and imaging of 99mTc-RRL were determined in different pulmonary metastases mouse models and in normal mice. Results: 99mTc-RRL exhibited higher uptake values in the lungs of pulmonary metastatic mice compared to normal mice (P<0.05; 3.92±0.48% ID/g 2 h post-injection and 3.89±0.36% ID/g 4 h post-injection in metastatic hepatic carcinoma [HepG2]-bearing lungs; 5.49±0.84% ID/g 2 h post-injection and 5.11±0.75% ID/g 4 h post-injection in metastatic melanoma [B16]-bearing lungs; 3.72±0.52% ID/g 2 h post-injection and 3.51±0.35% ID/g 4 h post-injection in metastatic cervical carcinoma [Hela]-bearing lungs; 2.38±0.20% ID/g 2 h post-injection and 2.11±0.24% ID/g 4 h post-injection in normal lungs). The pulmonary metastatic lesions were clearly visualized using 99mTc-RRL. Conclusions: 99mTc-RRL exhibited favorable metastatic tumor targeting and imaging properties, thus highlighting its potential as an effective imaging probe for detection of pulmonary metastases. 99mTc-RRL can be used as a reasonable supplement to 18F-FDG imaging in the non-invasive imaging of tumor angiogenesis. PMID:25932101

  8. Field-Scale Migration of 99Tc and 129I at the Nevada Test Site

    SciTech Connect

    Hu, Q; Smith, D K

    2003-10-16

    As a result of 828 underground nuclear weapons tests conducted between 1951 and 1992 at the Nevada Test Site (NTS), more than 1E+6 TBq of long-lived radionuclides (actinide device residuals, fission and activation products, etc.) are residual. Included in the radiologic inventory are {sup 99}Tc (technetium) and {sup 129}I (iodine) that are presumably mobile in groundwater and potentially toxic to down-gradient receptors. Understanding the controls of radionuclide mobility associated with these nuclear tests provides insights into the behavior of these same radionuclides in groundwater associated with the proposed Yucca Mountain high-level nuclear waste repository as well as the fidelity of numerical predictions of long-term repository performance. We synthesize a substantial body of data collected on the distribution of {sup 99}Tc and {sup 129}I associated with radionuclide migration studies at NTS, at field scales over distances of hundreds of meters and for durations up to forty years, under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results show that Tc does not necessarily exist as a mobile and conservative species TcO{sub 4}{sup -}, as commonly assumed. This is not unexpected as the speciation and migration behavior of {sup 99}Tc will be significantly controlled by the redox conditions of the nuclear test-induced cavity (initial distribution) and surrounding groundwater (subsequent migration). Numerous lines of evidence suggest that the chemical environment of a nuclear test cavity is likely to have a reducing nature immediately following a detonation. These conditions may persist for decades after a test. Recent in situ redox potential measurements indicated that groundwaters at multiple locations of the NTS are not oxidizing as previously believed. Mobility of Tc species (TcO{sub 2} {center_dot} nH{sub 2}O) is greatly reduced in non-oxidizing environment. Speciation of iodine and the reactivity and mobility of {sup 129}I species is also complex in the groundwater at the NTS.

  9. Biodistribution pharmacokinetics and radiation dosimetry of Tc-99m D-glucaric acid in humans

    SciTech Connect

    Molea, N.; Bodei, L.; Lazzeri, E. [Univ. of Pisa (Italy)]|[Univ. of Genoa (Italy)]|[Northeastern Univ., Boston, MA (United States)]|[Molecular Targeting Technology, Inc., Malvern, PA (United States)]|[Stanford Univ., CA (United States)] [and others

    1995-05-01

    Previous experimental studies have shown the high targeting potential of Tc-99m-labeled D-glucaric acid (TcGLA, a six-carbon dicarboxylic acid partly competing in vitro with fructose/glucose uptake) in animal models of acute ischemia/early necrosis of the heart or brain, and in human tumor xenografts. This study evaluated the biodistribution pharmacokinetics and radiation dosimetry of TcGLA in cancer patients. TcGLA (900 MBq) was injected i.v. as a bolus into 12 patients with breast (n=9) or colon (n=3) cancer. Whole-body scans were recorded at 0.5, 1,2,4,6, 10,24,32,46 hr while blood samples were taken at frequent intervals and urines were collected at 6-hr intervals. The MIRD approach was employed for radiation dosimetry estimates. No early or delayed adverse reactions of any type were observed. TcGLA showed an important, early and persistent accumulation in the kidneys (plateau at about 8-10% I.D.), combined with a slow hepatobiliary clearance. The TcGLA plasma disappearance curve was three-exponential, with average T {sub 1 2} values equal to 36.8, 1.4 and 0.4 hr, respectively. Urinary excretion was 45.8 {plus_minus} 7.4% I.D. from 0-6 hr, with a cumulative plateau of about 57% I.D. at 46 hr. while the cumulative extra-renal excretion was 15-30% I.D. The initial and total distribution volumes (12.5 {plus_minus} 0.9 and 47.9 {plus_minus} 81) corresponded to the extracellular and, respectively, the total body water. The main radiation dosimetry estimates (expressed as Gy/MBq) were 0.037 (kidneys), 0.065 (bladder), 0.002 (liver), 0.0035 (red marrow), 0.007 (ovaries) 0.005 (testes) and 0.003 (whole body). The favourable pharmacokinetic pattern and very low radiation dosimetry estimates obtained in this study enable further investigations on the imaging potential of TcGLA in various disease conditions.

  10. {sup 99}Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)

    SciTech Connect

    Lewis, L.A.

    1998-05-01

    A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max} beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of{sup 99}Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc{sub 2}O{sub 7} or during radiation detection due to color or chemical quenching. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the {sup 99}Tc isotope by ICP-MS is 2.175 x 10{sup {minus}7} {+-} 8.990 x 10{sup {minus}9} and by liquid scintillation is 7.434 x 10{sup {minus}14} {+-} 7.461 x 10{sup {minus}15}. A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD.

  11. Generational Myth

    ERIC Educational Resources Information Center

    Vaidhyanathan, Siva

    2008-01-01

    College students in America are not as "digital" as one might wish to pretend. And even at elite universities, many are not rich enough. All the mystical talk about a generational shift and all the claims that kids won't read books are not true. In this article, the author challenges the notion of "digital natives." The author argues that the term…

  12. TOPICAL REVIEW: Current status of high-Tc wire

    NASA Astrophysics Data System (ADS)

    Vase, Per; Flükiger, René; Leghissa, Martino; Glowacki, Bartek

    2000-07-01

    This paper is the result of the work of a SCENET (The European Network for Superconductivity) material working group's efforts on giving values for present and future expected performance of high-temperature superconducting (HTS) wires and tapes. The purpose of the work is to give input to the design of HTS applications like power cables, motors, current leads, magnets, transformers and generators. The current status performance values are supposed to be used in the design of today's prototypes and the future values for the design of fully commercial HTS applications of the future. We focus on what is expected to be the relevant parameters for HTS application design. The most successful technique by far for making HTS tapes has been on the (Bi, Pb)2Sr2Ca2Cu3Ox (Bi-2223) material by the powder-in-tube (PIT) technique and this paper therefore focuses on giving the current status and expected future performance for Bi-2223 tapes.

  13. [Assessment of left ventricular function with the solid-state digirad 2020tc Imager].

    PubMed

    Kumita, S; Cho, K; Nakajo, H; Toba, M; Akiyama, K; Oshina, T; Uwamori, M; Kosuge, Y; Mizumura, S; Kumazaki, T; Sano, J; Tanaka, K; Kishida, H; Takano, T

    2001-05-01

    Multigated equilibrium radionuclide ventriculography from best septal position (LAO view) was performed in 17 patients with cardiac disease with a single detector Anger-type gamma camera (GCA 602A, Toshiba), then immediately imaged with a solid-state, multi-crystal gamma camera (Digirad 2020tc Imager). Acquisition times were the same of 10 minutes. The solid-state gamma camera uses CsI(Tl) as the scintillation material and a Si photodiode. CsI(Tl) has a higher density and higher atomic number than NaI(Tl), so that its efficiency for detecting gamma rays is higher. To confirm this, total acquisition counts in 17 patients obtained from the 2020tc Imager were significantly higher than those obtained from the Anger-type camera (7847 +/- 2061 K vs. 4427 +/- 1162 K counts, p < 0.0001). In comparing left ventricular ejection fractions obtained from the Anger-type camera and the 2020tc Imager data, an excellent correlation was revealed with a correlation coefficient of 0.97 (p < 0.0001). Again, peak ejection rate and peak filling rate obtained from the 2020tc Imager data correlated well with those obtained from the Anger-type camera data (r = 0.93, p < 0.0001 and r = 0.80, p < 0.001, respectively). These data reveal that the 2020tc Imager has an excellent data collection efficiency and a high reliability in assessment of left ventricular function. Thus, the solid-state gamma camera was thought to be a useful hardware in nuclear cardiology. PMID:11452492

  14. Imaging Thromboembolism with Fibrin-Avid 99mTc-Peptide: Evaluation in Swine

    PubMed Central

    Aruva, Mohan R.; Daviau, Judy; Sharma, Shubh S.; Thakur, Mathew L.

    2006-01-01

    A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for ?-chain-fibrin was labeled with 99mTc (99mTc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE). Methods Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. 99mTc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, 99mTc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue. Results The affinity for human fibrin was 10?9 mol/L and there were >1015 receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9–22.6), DVT/muscle (31.1–89.4), PE/blood (1–155), and PE/lung (0.8–245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the ?-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms. Conclusion 99mTc-TP850 with its modest affinity (10?9 mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis. PMID:16391200

  15. Magnetism in EuBCO and YBCO vortex states near and below Tc

    NASA Astrophysics Data System (ADS)

    Schwartz, R.; Browne, M. C.; Boekema, C.

    2012-02-01

    By means of MaxEnt-?SR [1] analysis, we investigate transverse field ?SR data [2] of EuBa2Cu3O7-?gEuBCO; Tc = 93 K). Our focus is on a temperature interval near Tc to search for precursor effects, [3] and for predicted [4a] pseudogap loop currents above and below Tc, already observed [4b] above Tc for GdBCO. Further, we continue to study the field-direction dependence of the predicted [5a] and observed [5b] antiferromagnetism (AF) below 0.5Tc for the vortex states in c-axis-oriented YBCO. This AF in and near the vortex cores is likely three-dimensional. In sum, magnetic roots of cuprate superconductivity are well plausible. Research is supported by LANL-DOE, REU-NSF and AFC. [4pt] [1] C Boekema and MC Browne, AIP Conf Proc #1073 (2008) 260.[0pt] [2] DW Cooke et al, Phys Rev B 39 (1989) 2748.[0pt] [3] B Aguilar, C Boekema et al, Bull Am Phys Soc 37 (1992).[0pt] [4a] CM Varma, Phys Rev Lett 83 (1999) 3538.[0pt] [4b] T Songatikamas et al, J Supercond & Novel Magn 23 (2010) 793.[0pt] [5a] S-C Zhang, Science 275 (1997) 1089; H-D Chen et al, Phys Rev B70 (2004) 024516.[0pt] [5b] C. Boekema et al, J Phys Conf Series, 150 (2009) 052022. http://jpcs.iop.org/LT25

  16. TC1121-2 10/12/98 2001 Microchip Technology Inc. DS21358A s Optional High-Frequency Operation Allows Use of

    E-print Network

    Berns, Hans-Gerd

    from OSC (pin 7) to ground. The TC1121 also can be driven from an external clock connected OSC. Typical to +85°C TC1121EPA 8-Pin PDIP ­ 40°C to +85°C TC1121EUA 8-Pin MSOP ­ 40°C to +85°C SHDN TC1121 OSC CONTROL FC OSC GND VDD VOUT SWITCH MATRIX RC OSCILLATOR LOGIC CIRCUITS C2 C1+ C1 C1­ 1 2 3 4 8 7 6 5 FC

  17. Accumulation, solid partitioning and remobilisation of 99Tc in subtidal and intertidal sediments in the Irish Sea

    NASA Astrophysics Data System (ADS)

    Finegan, Paul; Vintró, Luis León; Mitchell, Peter I.; Boust, Dominique; Gouzy, Aurélien; Kershaw, Peter J.; Lucey, Julie A.

    2009-09-01

    Recent studies have shown that accumulation of 99Tc in seabed sediments labelled by authorised radioactive liquid discharges into the NE Irish Sea from the Sellafield reprocessing complex is greater than previously thought. In this paper, new data on 99Tc concentration profiles in subtidal and intertidal sediments from the eastern and western Irish Sea are provided with a view to elucidating the processes responsible for the incorporation and retention of 99Tc in the seabed. The data show that substantial amounts of 99Tc have accumulated in the fine-grained subtidal sediments off the Cumbrian coast, particularly after increased releases from Sellafield following the commissioning of the Enhanced Actinide Removal Plant (EARP) in 1994. In all the cores taken in this area, 99Tc has been found to be present to depths in excess of 30 cm. Analysis of 137Cs and 241Am profiles, together with other supporting geochemical data, show a high degree of homogenisation of the sediments down to these depths as a result of physical and biological processes, and confirm that incorporation of 99Tc into the sediment compartment is actually the result of mixing and reworking, rather than active sediment accumulation. In contrast, active deposition of material transported from this mixed pool of sediment appears to be the dominant mechanism controlling 99Tc profiles in intertidal areas close to the Sellafield discharge outfall. Data obtained from the analysis of subtidal sediment cores from the western Irish Sea mud basin suggest that similar mixing processes to those occurring in the subtidal sediments of the eastern Irish Sea are also active in this area. Time-series data on 99Tc concentrations in surficial sediments from this basin, gathered in the period 1988-2004, inclusive, show a clear increase in concentrations, by a factor of ˜2, between samples collected pre-EARP and post-EARP. The constancy of 99Tc concentrations in surface sediments throughout the 1980s and the early-1990s suggests that little redissolution and export of 99Tc occurred over this extended period. A similar observation applies to the post-EARP period, when concentrations remained relatively constant despite the reported steady decrease in 99Tc concentrations in the overlying waters. This apparent lack of remobilisation is consistent with data from sequential extraction analyses, which indicate that the bulk of the 99Tc is strongly bound to non-labile geochemical phases, with only a small proportion associated with exchangeable and acido-soluble phases. Further, these analyses show that 99Tc is not associated with oxygen-sensitive and highly-reactive acid-volatile sulphides (AVS) to any significant extent.

  18. New high Tc multiferroics KBiFe2O5 with narrow band gap and promising photovoltaic effect

    PubMed Central

    Zhang, Ganghua; Wu, Hui; Li, Guobao; Huang, Qingzhen; Yang, Chongyin; Huang, Fuqiang; Liao, Fuhui; Lin, Jianhua

    2013-01-01

    Intrinsic polarization of ferroelectrics (FE) helps separate photon-generated charge carriers thus enhances photovoltaic effects. However, traditional FE with transition-metal cations (M) of d0 electron in MO6 network typically has a band gap (Eg) exceeding 3.0?eV. Although a smaller Eg (2.6?eV) can be obtained in multiferroic BiFeO3, the value is still too high for optimal solar energy applications. Computational “materials genome” searches have predicted several exotic MO6 FE with Eg < 2.0?eV, all thus far unconfirmed because of synthesis difficulties. Here we report a new FE compound with MO4 tetrahedral network, KBiFe2O5, which features narrow Eg (1.6?eV), high Curie temperature (Tc ~ 780?K) and robust magnetic and photoelectric activities. The high photovoltage (8.8?V) and photocurrent density (15??A/cm2) were obtained, which is comparable to the reported BiFeO3. This finding may open a new avenue to discovering and designing optimal FE compounds for solar energy applications. PMID:23405279

  19. Splinter generator

    NASA Astrophysics Data System (ADS)

    Held, Manfred

    A splinter generator was designed, built and tested for the study of the synergistic effects in shooting at target structures with splinter-effect ammunition. The design of the generator and the test stand are described. Due to the possibility to correlate the positions of the hit encounters on the target plate, the angle of jump in elevation and azimuthal direction and hence the real paths between the detonation of the bursting charge and the X-ray flash pictures could be determined. This allows a precise determination of the velocities of the single splinters. In spite of the large scattering of the splinter penetration depths in the soft-iron target plate, a correlation between impact speed and working depth was deduced.

  20. Cluster generator

    DOEpatents

    Donchev, Todor I. (Urbana, IL); Petrov, Ivan G. (Champaign, IL)

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  1. Electric generator

    DOEpatents

    Foster, Jr., John S. (Pleasanton, CA); Wilson, James R. (Livermore, CA); McDonald, Jr., Charles A. (Danville, CA)

    1983-01-01

    1. In an electrical energy generator, the combination comprising a first elongated annular electrical current conductor having at least one bare surface extending longitudinally and facing radially inwards therein, a second elongated annular electrical current conductor disposed coaxially within said first conductor and having an outer bare surface area extending longitudinally and facing said bare surface of said first conductor, the contiguous coaxial areas of said first and second conductors defining an inductive element, means for applying an electrical current to at least one of said conductors for generating a magnetic field encompassing said inductive element, and explosive charge means disposed concentrically with respect to said conductors including at least the area of said inductive element, said explosive charge means including means disposed to initiate an explosive wave front in said explosive advancing longitudinally along said inductive element, said wave front being effective to progressively deform at least one of said conductors to bring said bare surfaces thereof into electrically conductive contact to progressively reduce the inductance of the inductive element defined by said conductors and transferring explosive energy to said magnetic field effective to generate an electrical potential between undeformed portions of said conductors ahead of said explosive wave front.

  2. Tc(IV)Cl 4(PPh 3) 2 and Tc(III)Cl 3(CH 3CN)(PPh 3) 2 as precursors of trans dioxo technetium(V) complexes with chelating amines and tetraazamacrocycles

    Microsoft Academic Search

    Françoise Riché; Michel Vidal; Cristina Bolzati; Licia Uccelli; Andrea Marchi; Adriano Duatti

    1995-01-01

    The trans dioxo complexes [TcO2(L)]+ (L = 1,4,8,11-tetraazacyclotetradecane (cyclam), 1,4,8,11-tetraazacyclotetradecane-5-one, 1,4,8,11-tetraazacyclotetradecane-5,7-dione) have been prepared through a new alternative route involving the reaction of excess of the appropriate ligand with the complexes [TcCl4(PPh3)2] and [TcCl3(CH3CN)(PPh3)2] in CH3CN solution, at room temperature. The yields of formation of the final products obtained through this new synthetic method (30–55%) are significantly higher than that

  3. [Evaluation of efficiency of a multi-crystal scintillation camera Digirad 2020tc Imager using a solid-state detectors].

    PubMed

    Narita, H; Kawaida, Y; Ooshita, T; Itoh, T; Tsuchida, D; Fukumitsu, N; Mori, Y; Makino, M

    2001-07-01

    Digirad 2020tc Imager is the movable scintillation camera, consisting of combining multi-crystal scintillators (CsI(Tl)) and photo-diodes. Total numbers of element are 4096, which are further divided into 16 x 16 modules. Each module contains 4 x 4 elements. We have examined Digirad 2020tc according to NEMA (National Electrical Manufactures Association), and the following results are obtained; the maximum count rate; 221 kcps, total system uniformity; 1.3% (integral uniformity), 0.9% (differential uniformity), system spatial resolution; 6.97 +/- 0.72 mm (the LEHR collimator to 99mTc source at 10 cm), intrinsic energy resolution; 12.8%, total system sensitivity; 3270.8 cpm/MBq (with LEHR collimator using 99mTc source at 10 cm). Further more, we determined the contrast of an imaging using the pin-hole (100 microns phi) 99mTc source in order to know the signal per noise (S/N) ratio among the pixels (S/N; 93.4 +/- 46.2 (first pixels)). Although the physical dimension of the camera has a smaller field of view, comparing with the standard camera, Digirad 2020tc has the equivalent characteristics as well as that of the standard camera and its field view is enough to measure the adult lung perfusion using a diverging collimator. We will further examine Digirad 2020tc with its movable portability and expect applications in nuclear medicine. PMID:11530383

  4. Effects of prenatal AZT+3TC treatment on open field behavior and responsiveness to scopolamine in adult mice.

    PubMed

    Calamandrei, G; Venerosi, A; Valanzano, A; Alleva, E

    2000-11-01

    Treatment of pregnant seropositive women and their neonates with the nucleoside analogs (reverse transcriptase inhibitors) zidovudine (AZT), lamivudine (3TC) and their combination has become a standard of care in industrialized countries to prevent transmission of the HIV-1 virus. Animal studies indicated limited but significant behavioral changes in AZT or 3TC-prenatally exposed offspring, whereas data on the potential neurobehavioral outcomes of AZT+3TC combination are still lacking. The aim of the present study was to assess in mice prenatally exposed to AZT+3TC the functional state of cholinergic muscarinic neuroregulation at adulthood. Pregnant CD-1 mice received per orem twice daily AZT+3TC (160 and 500 mg/kg, respectively) or vehicle solution (NaCl 0.9%) from gestational day (GD) 10 to delivery (GD 19). Locomotor activity, exploratory behavior and responsiveness to the muscarinic cholinergic blocker scopolamine (2 mg/kg) were analyzed at adulthood (PND 70) in offspring of both sexes in an open field test. Results indicated that prenatal AZT+3TC exposure does not influence responsiveness to the muscarinic cholinergic antagonist as measured by analysis of the drug's effects on locomotor and exploratory activity and different behavioral items. However, AZT+3TC-treated mice displayed higher frequency of rearing, and lower frequency and duration of self-grooming behavior, consistent with an effect on dopaminergic neurotransmission. However, this would need confirmatory experiments. PMID:11164081

  5. Products of pertechnetate radiolysis in highly alkaline solution: structure of TcO2 x xH2O.

    PubMed

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

    2002-03-01

    The chemistry of technetium in certain high-level nuclear waste (HLW) tanks at the Hanford Site complicates the treatment and vitrification of HLW. A major problem is the presence, in certain tanks, of unidentified, lower-valent technetium species, which are difficult to remove from the waste by current separation processes. Radiolytic reduction of TcO4- in alkaline solutions containing selected organic compounds, approximating the conditions in HLW, was investigated to determine the classes of compounds that can be formed under these conditions. Insoluble TcO2 x xH2O is the primary radiolysis product with the majority of organic compounds investigated, including citrate, dibutyl phosphate, and aminopolycarboxylates. X-ray absorption fine structure (XAFS) measurements show that TcO2 x xH2O has a one-dimensional chain structure consisting of edge-sharing TcO6 octahedra with bridging oxide and trans water ligands. When diols, such as ethylene glycol, are present, only soluble, Tc(IV) alkoxide compounds are produced. The XAFS and UV-visible spectra of these compounds provide evidence for a binuclear structure similar to (H2EDTA)2Tc2(mu-O)2. The properties of the Tc(IV) alkoxide complexes were determined and are consistent with those observed for the soluble, lower-valent technetium complexes that complicate the treatment of HLW at the Hanford site. PMID:11918000

  6. Preparation and Crystal Structure of a Rhenium Analogue of the Cationic Renal Agent, Tc-99m Diaminocyclohexane

    PubMed Central

    Hansen, Lory; Taylor, Andrew; Lachicotte, Rene

    2000-01-01

    We report here a chemical study on a Re analogue of one of the few cationic Tc-99m tracers previously investigated as an agent for effective renal plasma flow (ERPF) measurement. Cationic Tc-99m tracers have the potential for overcoming problems associated with common anionic Tc-99m tracers in patients who have developed a uremic state. The Tc-99m-DACH tracer, prepared from 1,2-diaminocyclohexane (1,2-DACH), is the only cationic renal agent tested in humans and has seven possible isomers. The complex isolated from the reaction of the racemic mixture, (±)-trans-1,2-DACH, and ReIO2(PPh3)2 after conversion to the BPh4- salt was found by X-ray crystallography to be the meso isomer, trans-[ReO2 (trans-R,R-1,2-DACH)(trans-S,S-l,2-DACH)][BPh4]·MeOH·2H2O (1). The structural parameters for 1 are normal. The complex is highly symmetrical, suggesting that the analogous meso Tc-99m-DACH agent is also symmetrical. Studies of other Tc-99m-DACH agents that were made from cis-1,2-DACH or individual trans-1,2-DACH enantiomers show that the biodistribution is not very dependent on the starting 1,2-DACH ligand stereochemistry; these agents must be less symmetrical than the meso Tc-99m-DACH agent analogue of 1. Thus, the overall charge and lipophilicity (similar for all Tc-99m-DACH isomers) exert a greater influence on biodistribution than the specific structural features of the different Tc-99m-DACH isomers. PMID:18475937

  7. 99mTc-Labeled Cystine Knot Peptide Targeting Integrin ?v?6 for Tumor SPECT Imaging

    PubMed Central

    2015-01-01

    Integrin ?v?6 is overexpressed in a variety of cancers, and its expression is often associated with poor prognosis. Therefore, there is a need to develop affinity reagents for noninvasive imaging of integrin ?v?6 expression since it may provide early cancer diagnosis, more accurate prognosis, and better treatment planning. We recently engineered and validated highly stable cystine knot peptides that selectively bind integrin ?v?6 with no cross-reactivity to integrins ?v?5, ?5?1, or ?v?3, also known to be overexpressed in many cancers. Here, we developed a single photon emission computed tomography (SPECT) probe for imaging integrin ?v?6 positive tumors. Cystine knot peptide, S02, was first conjugated with a single amino acid chelate (SAAC) and labeled with [99mTc(H2O)3(CO)3]+. The resulting probe, 99mTc-SAAC-S02, was then evaluated by in vitro cell uptake studies using two ?v?6 positive cell lines (human lung adenocarcinoma cell line HCC4006 and pancreatic cancer cell line BxPC-3) and two ?v?6 negative cell lines (human lung adenocarcinoma cell line H838 and human embryonic kidney cell line 293T). Next, SPECT/CT and biodistribution studies were performed in nude mice bearing HCC4006 and H838 tumor xenografts to evaluate the in vivo performance of 99mTc-SAAC-S02. Significant differences in the uptake of 99mTc-SAAC-S02 were observed in ?v?6 positive vs negative cells (P < 0.05). Biodistribution and small animal SPECT/CT studies revealed that 99mTc-SAAC-S02 accumulated to moderate levels in antigen positive tumors (?2% ID/g at 1 and 6 h postinjection, n = 3 or 4/group). Moreover, the probe demonstrated tumor-to-background tissue ratios of 6.81 ± 2.32 (tumor-to-muscle) and 1.63 ± 0.18 (tumor-to-blood) at 6 h postinjection in ?v?6 positive tumor xenografts. Co-incubation of the probe with excess amount of unlabeled S02 as a blocking agent demonstrated significantly reduced tumor uptake, which is consistent with specific binding to the target. Renal filtration was the main route of clearance. In conclusion, knottin peptides are excellent scaffolds for which to develop highly stable imaging probes for a variety of oncological targets. 99mTc-SAAC-S02 demonstrates promise for use as a SPECT agent to image integrin ?v?6 expression in living systems. PMID:24524409

  8. 99mTc-labeled cystine knot peptide targeting integrin ?v?6 for tumor SPECT imaging.

    PubMed

    Zhu, Xiaohua; Li, Jinbo; Hong, Yeongjin; Kimura, Richard H; Ma, Xiaowei; Liu, Hongguang; Qin, Chunxia; Hu, Xiang; Hayes, Thomas R; Benny, Paul; Gambhir, Sanjiv Sam; Cheng, Zhen

    2014-04-01

    Integrin ?v?6 is overexpressed in a variety of cancers, and its expression is often associated with poor prognosis. Therefore, there is a need to develop affinity reagents for noninvasive imaging of integrin ?v?6 expression since it may provide early cancer diagnosis, more accurate prognosis, and better treatment planning. We recently engineered and validated highly stable cystine knot peptides that selectively bind integrin ?v?6 with no cross-reactivity to integrins ?v?5, ?5?1, or ?v?3, also known to be overexpressed in many cancers. Here, we developed a single photon emission computed tomography (SPECT) probe for imaging integrin ?v?6 positive tumors. Cystine knot peptide, S02, was first conjugated with a single amino acid chelate (SAAC) and labeled with [(99m)Tc(H2O)3(CO)3](+). The resulting probe, (99m)Tc-SAAC-S02, was then evaluated by in vitro cell uptake studies using two ?v?6 positive cell lines (human lung adenocarcinoma cell line HCC4006 and pancreatic cancer cell line BxPC-3) and two ?v?6 negative cell lines (human lung adenocarcinoma cell line H838 and human embryonic kidney cell line 293T). Next, SPECT/CT and biodistribution studies were performed in nude mice bearing HCC4006 and H838 tumor xenografts to evaluate the in vivo performance of (99m)Tc-SAAC-S02. Significant differences in the uptake of (99m)Tc-SAAC-S02 were observed in ?v?6 positive vs negative cells (P < 0.05). Biodistribution and small animal SPECT/CT studies revealed that (99m)Tc-SAAC-S02 accumulated to moderate levels in antigen positive tumors (?2% ID/g at 1 and 6 h postinjection, n = 3 or 4/group). Moreover, the probe demonstrated tumor-to-background tissue ratios of 6.81 ± 2.32 (tumor-to-muscle) and 1.63 ± 0.18 (tumor-to-blood) at 6 h postinjection in ?v?6 positive tumor xenografts. Co-incubation of the probe with excess amount of unlabeled S02 as a blocking agent demonstrated significantly reduced tumor uptake, which is consistent with specific binding to the target. Renal filtration was the main route of clearance. In conclusion, knottin peptides are excellent scaffolds for which to develop highly stable imaging probes for a variety of oncological targets. (99m)Tc-SAAC-S02 demonstrates promise for use as a SPECT agent to image integrin ?v?6 expression in living systems. PMID:24524409

  9. Bulk superconductivity at an elevated temperature (Tc~=12 K) in a nickel containing alloy system Y-Ni-B-C

    Microsoft Academic Search

    R. Nagarajan; Chandan Mazumdar; Zakir Hossain; S. K. Dhar; K. V. Gopalakrishnan; L. C. Gupta; C. Godart; B. D. Padalia; R. Vijayaraghavan

    1994-01-01

    We report here our discovery of bulk superconductivity at rather high Tc in samples having nominal compositions YNi4BO0.2 (Tc~=12.5 K) and YNi2B3O0.2 (Tc~=13.5 K). While YNi4BC0.2 seems to be a single phase material, YNi2B3C0.2 is a multiphase system. Our experimental results show that the two materials are distinct superconductors. Discovery of superconductivity in these materials is of significance since not

  10. Tide generator

    SciTech Connect

    Feltenberger, B.D.

    1981-06-16

    A tidewater power system consisting of a high tide reservoir and a low tide reservoir. The high tide reservoir has an inlet adapted to be supported at high tide level and an outlet with a water wheel and generator between the outlet of the high tide reservoir and the low tide reservoir. The low tide reservoir has an outlet at the low tide level. The outlet from the high tide reservoir is adjustable to control the flow rate and the high tide reservoir can be closed at high tide to retain water for use over a period of time.

  11. In vitro and in vivo study of 99m Tc-MIBI encapsulated in PEG-liposomes: a promising radiotracer for tumour imaging

    Microsoft Academic Search

    Hayet Belhaj-Tayeb; Dominique Briane; Jackie Vergote; Suchart Kothan; Gérard Léger; Saad-Eddine Bendada; Mojdeh Tofighi; Feyzi Tamgac; An Cao; Jean-Luc Moretti

    2003-01-01

    Encapsulation of technetium-99m sestamibi (99mTc-MIBI) in polyethyleneglycol-liposomes (99mTc-MIBI-PEG-liposomes) could extend the duration of its circulation in blood and alter its biodistribution, enabling its concentration in tumours to be increased. An original method to encapsulate 99mTc-MIBI in PEG-liposomes is described. The 99mTc-MIBI-PEG-liposomes were compared with free 99mTc-MIBI with respect to (a) tumour availability (b) ability to distinguish between chemotherapy-sensitive and -resistant

  12. The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs.

    PubMed

    Duz, Ana Luiza Cassin; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Aguiar-Soares, Rodrigo Dian Oliveira; Cardoso, Jamille Mirelle de Oliveira; Oliveira, Flávia Carvalho Bitencourt de; Reis, Levi Eduardo Soares; Tafuri, Washington Luiz; Veloso, Vanja Maria; Reis, Alexandre Barbosa; Carneiro, Cláudia Martins

    2014-12-01

    Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8+ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4+/CD8+ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-? by CD4+ and CD8+ T-lymphocytes and IL-4 by CD8+ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host. PMID:25591108

  13. Preclinical evaluation of 99mTc(CO)3-aspartic-N-monoacetic acid, 99mTc(CO)3(ASMA), a new renal radiotracer with pharmacokinetic properties comparable to 131I-OIH

    PubMed Central

    Lipowska, Malgorzata; Klenc, Jeffrey; Marzilli, Luigi G.; Taylor, Andrew T.

    2014-01-01

    In an ongoing effort to develop a renal tracer with pharmacokinetic properties comparable to PAH and superior to those of both 99mTc-MAG3 and 131I-OIH, we evaluated a new renal tricarbonyl radiotracer based on the aspartic-N-monoacetic acid ligand, 99mTc(CO)3(ASMA). The ASMA ligand features two carboxyl groups and an amine function for the coordination of the {99mTc(CO)3}+ core as well as a dangling carboxylate to facilitate rapid renal clearance. Methods rac-ASMA and L-ASMA were labeled with a 99mTc-tricarbonyl precursor and radiochemical purity of the labeled products was determined by HPLC. Using 131I-OIH as an internal control, we evaluated biodistribution in normal rats with 99mTc(CO)3(ASMA) isomers and in rats with renal pedicle ligation with 99mTc(CO)3(rac-ASMA). Clearance studies were conducted in 4 additional rats. In vitro radiotracer stability was determined in PBS buffer pH 7.4 and in challenge studies with cysteine and histidine. 99mTc(CO)3(ASMA) metabolites in urine were analyzed by HPLC. Results Both 99mTc(CO)3(ASMA) preparations had > 99% radiochemical purity and were stable in PBS buffer pH 7.4 for 24 h. Challenge studies on both revealed no significant displacement of the ligand. In normal rats, % injected dose in urine at 10 and 60 min for both preparations averaged 103% and 106% that of 131I-OIH, respectively. The renal clearances of 99mTc(CO)3(rac-ASMA) and 131I-OIH were comparable (P = 0.48). The tracer was excreted unchanged in the urine, proving its in vivo stability. In pedicle-ligated rats, 99mTc(CO)3(rac-ASMA) had less excretion into the bowel (P < 0.05) and was better retained in the blood (P < 0.05) than 131I-OIH. Conclusion Both 99mTc(CO)3(ASMA) complexes have pharmacokinetic properties in rats comparable to or superior to those of 131I-OIH, and human studies are warranted for their further evaluation. PMID:22717977

  14. Quasiparticle mass enhancement approaching optimal doping in a high-Tc superconductor

    NASA Astrophysics Data System (ADS)

    Ramshaw, B. J.; Sebastian, S. E.; McDonald, R. D.; Day, James; Tan, B. S.; Zhu, Z.; Betts, J. B.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Harrison, N.

    2015-04-01

    In the quest for superconductors with higher transition temperatures (Tc), one emerging motif is that electronic interactions favorable for superconductivity can be enhanced by fluctuations of a broken-symmetry phase. Recent experiments have suggested the existence of the requisite broken-symmetry phase in the high-Tc cuprates, but the impact of such a phase on the ground-state electronic interactions has remained unclear. We used magnetic fields exceeding 90 tesla to access the underlying metallic state of the cuprate YBa2Cu3O6+? over a wide range of doping, and observed magnetic quantum oscillations that reveal a strong enhancement of the quasiparticle effective mass toward optimal doping. This mass enhancement results from increasing electronic interactions approaching optimal doping, and suggests a quantum critical point at a hole doping of pcrit ? 0.18.

  15. Transfer of /sup 131/I and /sup 95m/Tc from pasture to goat milk

    SciTech Connect

    Bondietti, E.A.; Garten, C.T. Jr.

    1984-01-01

    Field measurements were made in 1983 on the transfer of /sup 131/I and /sup 95m/Tc from spray-contaminated pasture to goat's milk. The transfer of /sup 131/I to milk was similar to that used for mathematical models in US Nuclear Regulatory Commission Regulatory Guide 1.109, which was derived from stall-feeding experiments using capsulized doses. Compared to /sup 131/I, the /sup 95m/Tc transferred to milk was about 5600 times less. The lower transfer resulted from both immobilization of technetium on pasture prior to ingestion as well as reduced gastrointestinal absorption. The results show that the food chain transfer of technetium to milk is much less than that previously expected based on inferences made from metabolism studies. 6 references, 4 figures, 1 table.

  16. Evaluation of Nasal Mucociliary Transport Rate by99mTc-Macroaggregated Albumin Rhinoscintigraphy in Woodworkers

    PubMed Central

    Dostbil, Zeki; Polat, Cahit; Uysal, ?smail Önder; Bak?r, Salih; Karaku?, Askeri; Alt?nda?, Serdar

    2011-01-01

    Woodworkers in the furniture industry are exposed to wood dust in their workplaces. The aim of this study is to investigate the effect of occupational wood dust exposure on the nasal mucociliary transport rates (NMTRs) in woodworkers. Twenty five woodworkers and 30 healthy controls were included in this study. Wood dust concentration in workplaces was measured using the sampling device. 99m Tc-macroaggregated albumin (99mTc-MAA) rhinoscintigraphy was performed, and NMTR was calculated in all cases. In statistical analysis, an independent samples t-test was used to compare NMTR of woodworkers and control subjects. We found that the mean NMTR of the woodworkers was lower than that of the healthy controls. However, there was not a statistically significant difference between them (P = 0.066). In conclusion, our findings suggested that wood dust exposure may not impair nasal mucociliary transport rate in woodworkers employed in joinery workshops. PMID:21804940

  17. New separations technologies for TcO{sub 4}: Applications from nuclear medicine to nuclear waste

    SciTech Connect

    Rogers, R.D. [Univ. of Alabama, Tuscaloosa, AL (United States); Bond, A.H.; Bauer, C.B. [Northern Illinois Univ., DeKalb, IL (United States)

    1996-12-31

    Aqueous biphasic systems (ABS) are formed when aqueous polyethylene glycols (PEGs) are salted-out by specific aqueous salt solutions providing two immiscible aqueous layers. We have shown that chaotropic ions prefer the PEG-rich phase and thus partition to this phase. Recently, we have prepared PEG-bound resins that exhibit AB S behavior and have demonstrated their ability to selectively separate TcO{sub 4}{sup -}. This presentation will highlight two areas where ABS may find utility in separations of the pertechnetate anion: high ionic strength solutions such as those found in the Westinghouse Hanford radioactive waste storage tanks, and in the isolation of {sup 99m}Tc for radiopharmacy.

  18. Dynamics of Chemical Equilibrium of Hadronic Matter Close to $T_c$

    E-print Network

    J. Noronha-Hostler; M. Beitel; C. Greiner; I. Shovkovy

    2009-09-16

    Quick chemical equilibration times of hadrons (specifically, $p\\bar{p}$, $K\\bar{K}$, $\\Lambda\\bar{\\Lambda}$, and $\\Omega\\bar{\\Omega}$ pairs) within a hadron gas are explained dynamically using Hagedorn states, which drive particles into equilibrium close to the critical temperature. Within this scheme, we use master equations and derive various analytical estimates for the chemical equilibration times. We compare our model to recent lattice results and find that for both $T_c=176$ MeV and $T_c=196$ MeV, the hadrons can reach chemical equilibrium almost immediately, well before the chemical freeze-out temperatures found in thermal fits for a hadron gas without Hagedorn states. Furthermore the ratios $p/\\pi$, $K/\\pi$, $\\Lambda/\\pi$, and $\\Omega / \\pi $ match experimental values well in our dynamical scenario.

  19. Space-time interface-tracking with topology change (ST-TC)

    NASA Astrophysics Data System (ADS)

    Takizawa, Kenji; Tezduyar, Tayfun E.; Buscher, Austin; Asada, Shohei

    2014-10-01

    To address the computational challenges associated with contact between moving interfaces, such as those in cardiovascular fluid-structure interaction (FSI), parachute FSI, and flapping-wing aerodynamics, we introduce a space-time (ST) interface-tracking method that can deal with topology change (TC). In cardiovascular FSI, our primary target is heart valves. The method is a new version of the deforming-spatial-domain/stabilized space-time (DSD/SST) method, and we call it ST-TC. It includes a master-slave system that maintains the connectivity of the "parent" mesh when there is contact between the moving interfaces. It is an efficient, practical alternative to using unstructured ST meshes, but without giving up on the accurate representation of the interface or consistent representation of the interface motion. We explain the method with conceptual examples and present 2D test computations with models representative of the classes of problems we are targeting.

  20. Simulation of the initial response of a high Tc thin film submitted to a voltage source

    NASA Astrophysics Data System (ADS)

    Reymond, Serge; Antognazza, Louis; Decroux, Michel; Fischer, Oystein

    2004-03-01

    HTC thin films are one of the systems currently being investigated for the realization of a resistive fault current limiter. Upon testing, different groups have observed a very similar initial switching, that occurs during the first few microseconds following the connection to a voltage source: the current density flowing into the limiting device peaks up to a well defined value and then quickly decreases and stabilizes to approximately the half of the peak value. To understand this behavior, we propose a model based on the existence of a critical current density j(T), above which a highly dissipative state is established in the films. This model contrasts with the usual explanation of hot spots heating beyond T_c. Using this model, we have numerically simulated the response of a high Tc superconducting film connected to a voltage source. Our calculation exhibits the main observed features and can provide some guidelines for the design of superconducting thin film fault current limiters.

  1. Localization of human brain tumors by Tc-99m labelled P-280 synthetic peptide

    SciTech Connect

    Muto, P.; Varrella, P.; Vergara, E. [Univ. Federico II Napoli (Italy)] [and others

    1994-05-01

    A preliminary study in humans, using a 3021D molecular weight synthetic peptide (26 amino acids) which includes the RGD sequence that binds to the IIb/IIIa receptor expressed by activated platelets as well as by neoplasm cells, is reported. P-280 labelled with Tc-99M, via a chelator fused to the peptide, allows external gamma imaging. We have studied 21 patients (8 M/ 13 F, 21 to 80 years) with various diseases to define the pharmacokinetic and diagnostic accuracy of this probe. Imaging was performed as follows: dynamic, 0-15 min; planar 0.5, 2 and 4hrs; SPET 3 hrs. p.i. Doses ranged between 17.5-28 mCi of Tc-99m P-280 (0.2-0.4 mg).

  2. Fabrication and electrical properties of a high-Tc superconducting layered conductor

    NASA Astrophysics Data System (ADS)

    Noji, H.

    1999-08-01

    A high-Tc superconducting layered conductor designed for a small cross-section and a relatively low current capacity is fabricated by Bi-2212 tapes and interlayer insulation. The Bi-2212 tapes are prepared by the screen-printing method and the melt-solidification process with slow cooling under monotonically reduced oxygen partial pressure. Fifteen tapes with Tc valueicons/Journals/Common/cong" ALT="cong" ALIGN="TOP"/>90 K and Jc value icons/Journals/Common/cong" ALT="cong" ALIGN="TOP"/>1 × 104 A cm-2 at 77 K and 0 T are selected to construct the conductor. Dc and ac transport measurements of the conductor show that the Ic value is 250 A which is decreased by 17% from an estimation, and the ac loss is described by the Norris equation in the elliptical approximation at the normalized current i < 0.7 even though the cross-section is a rectangle.

  3. Large enhancement of Tc of Sr2RuO4 under uni-axial strain

    NASA Astrophysics Data System (ADS)

    Brodsky, Daniel O.; Hicks, Clifford W.; Yelland, Edward A.; Gibbs, Alexandra S.; Bruin, Jan A. N.; Barber, Mark E.; Edkins, Stephen D.; Nishimura, Keigo; Yonezawa, Shingo; Maeno, Yoshiteru; MacKenzie, Andrew P.

    2014-03-01

    We present AC magnetic susceptibility data taken on samples of the spin-triplet superconductor Sr2RuO4 under uni-axial strain. To do this, we built a probe that enables us to vary the strain applied to our samples continuously from compression to tension, whilst at cryogenic temperatures. We found that Tc changes dramatically with in-plane strain: strain along the crystallographic [100] direction leads to a strong strain-symmetric response of Tc, which is pushed up from 1.35 K to 1.9 K for 0.23% strain. Conversely, the response along the [110] direction is weak and mostly linear in strain. We discuss these results in the context of the predicted px + i py topological order parameter.

  4. Immobilization of {sup 99}Tc in low-temperature phosphate ceramic waste forms

    SciTech Connect

    Singh, D.; Mandalika, V.; Wagh, A.; Strain, R.; Tlustochowicz, M. [Argonne National Lab., IL (United States). Energy Technology Div.

    1997-05-01

    Radionuclides such as {sup 99}Tc are by-products of fission reactions in high-level wastes. Technetium poses a serious environmental threat because it is easily oxidized into its highly leachable pertechnetate form. Magnesium potassium phosphate ceramics have been developed to treat {sup 99}Tc that has been separated and eluted from simulated high-level tank wastes by sorption processes. Dense and hard ceramic waste forms were fabricated by acid-base reactions between mixtures of magnesium oxide powders and wastes, and acid phosphate solutions. Standard leaching tests, such as ANS 16.1 and the Product Consistency Test, were conducted on the final waste forms to establish their performance. The fate of the contaminants in the final waste forms was established with scanning electron microscopy techniques. In addition, stability of the waste forms in aqueous environments was evaluated by long-term water immersion tests.

  5. In vivo pH imaging with 99mTc-pHLIP

    PubMed Central

    Macholl, Sven; Morrison, Matthew S.; Iveson, Peter; Arbo, Bente E.; Andreev, Oleg A.; Reshetnyak, Yana K.; Engelman, Donald M.; Johannesen, Edvin

    2014-01-01

    Purpose A novel molecular imaging agent has been developed recently which stains tissues of low extracellular pH (pH (low) insertion peptide, pHLIP®). A pH-dependent process of peptide folding and insertion into cell membranes has been found in vitro. Targeting of acidic solid tumours has been demonstrated in vivo using fluorescence and PET labels. Here we present proof of feasibility studies of pHLIP with a SPECT label, 99mTc-AH114567, with focus on preclinical efficacy and imageability. Procedures LLC, LNCaP and PC-3 tumour xenografts were grown in mice and characterised by the angiogenesis marker 99mTc-NC100692 and by extracellular pH measurements with 31P-MRS of 3-aminopropyl phosphonate. Biodistribution was assessed and CT/SPECT imaging performed. Oral administration of bicarbonate served as control. Results and Conclusion 99mTc-AH114567 can be obtained via a robust synthesis with good radiolabelling profile and improved formulation. The tracer retains the pH-dependent ability to insert into membranes and to target tumours with similar pharmacokinetics and efficacy that had been demonstrated earlier for pHLIP with optical or 64Cu PET labels. Despite the inherent challenges of SPECT compared to optical and PET imaging e.g. in terms of lower sensitivity, 99mTc-AH114567 shows adequate image quality and contrast. The main development need for transitioning SPECT labelled pHLIP into the clinic is more rapid background signal reduction which will be the focus of a subsequent optimization study. PMID:22371188

  6. Diffusely increased Tc-99m-MDP uptake in both kidneys

    SciTech Connect

    Koizumi, K.; Tonami, N.; Hisada, K.

    1981-08-01

    Patients with diffusely increased uptake in both kidneys (often referred to as ''host kidneys'') on Tc-99m-MDP bone imaging were evaluated. Among 2056 patients reviewed, this finding was seen in 13 patients (0.63%): four with liver cirrhosis, two with lung cancer, one each with primary hepatoma, Hodgkin's disease, malignant lymphoma, thyroid cancer, leukemia, sideroblastic anemia and diabetes mellitus. Renal vascular disease and iron overload are considered to be the major causes of this finding.

  7. Effective single-band models for the high-Tc cuprates. I. Coulomb interactions

    Microsoft Academic Search

    L. F. Feiner; J. H. Jefferson; R. Raimondi

    1996-01-01

    Starting with the three-band extended Hubbard model (or d-p model) widely used to represent the CuO2 planes in the high-Tc cuprates, we make a systematic reduction to an effective single-band model using a previously developed cell-perturbation method. The range of parameters for which this mapping is a good approximation is explored in the full Zaanen-Sawatzky-Allen diagram (copper Coulomb repulsion Ud

  8. Review of the state of the art of high-Tc superconducting technology. Final report

    SciTech Connect

    Tauritz, J.L.

    1990-06-01

    Phenomenological aspects of superconductivity are summarized, particularly with respect to use at microwave frequencies. Bulk and thin-film methods of fabrication of high T(c) materials are described, and recent experimental results are reported. Applicability to microwave component design is considered, and a number of device demonstrators are reviewed. Representative European and non-European activities of relevance to future space vehicle borne microwave systems are discussed.

  9. Prophylactic Efficacy of TcVac2 against Trypanosoma cruzi in Mice

    Microsoft Academic Search

    Shivali Gupta; Nisha Jain Garg

    2010-01-01

    BackgroundChagas disease is a major health problem in Latin America, and an emerging infectious disease in the US. Previously, we have screened the Trypanosoma cruzi sequence database by a computational\\/bioinformatics approach, and identified antigens that exhibited the characteristics of vaccine candidates.MethodologyWe investigated the protective efficacy of a multi-component DNA-prime\\/protein-boost vaccine (TcVac2) constituted of the selected candidates and cytokine (IL-12 and

  10. High-Tc superconducting surface coil for 2 tesla magnetic resonance imaging of small animals

    Microsoft Academic Search

    J. Wosik; F. Wang; L.-M. Xie; M. Strikovski; M. Kamel; K. Nesteruk; M. Bilgen; P. A. Narayana

    2001-01-01

    The performance of small-volume Magnetic Resonance Imaging (MRI) depends on the system noise determined by noise of a probe and\\/or of a preamplifier (not by the body noise). Several demonstrations confirmed that, for selected applications, high-Tc superconductor MRI receiver coils have superior properties to those of comparable copper coils. We report on the outstanding performance of modified twin horseshoe YBCO

  11. Total absorption study of the ? decay of 102,104,105Tc

    NASA Astrophysics Data System (ADS)

    Jordan, D.; Algora, A.; Taín, J. L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A. B.; Molina, F.; Caballero, L.; Nácher, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyás, J.; Vitéz, A.; Csatlós, M.; Csige, L.; Äysto, J.; Penttilä, H.; Moore, I. D.; Eronen, T.; Jokinen, A.; Nieminen, A.; Hakala, J.; Karvonen, P.; Kankainen, A.; Saastamoinen, A.; Rissanen, J.; Kessler, T.; Weber, C.; Ronkainen, J.; Rahaman, S.; Elomaa, V.; Hager, U.; Rinta-Antila, S.; Sonoda, T.; Burkard, K.; Hüller, W.; Batist, L.; Gelletly, W.; Nichols, A. L.; Yoshida, T.; Sonzogni, A. A.; Peräjärvi, K.; Petrovici, A.; Schmid, K. W.; Faessler, A.

    2013-04-01

    The ?-feeding probabilities for three important contributors to the decay heat in nuclear reactors, namely 102,104,105Tc, have been measured using the total absorption spectroscopy technique. For the measurements, sources of very high isobaric purity have been obtained using a Penning trap (JYFLTRAP). A detailed description of the data analysis is given and the results are compared with high-resolution measurements and theoretical calculations.

  12. Attenuation of atomic-field bremsstrahlung from 204Tl and 99Tc in a thick target

    Microsoft Academic Search

    E. E. Abdel-Hady; A. M. A. El-Sayed; N. Nagy; A. A. Ahmed

    1996-01-01

    Attenuation of the atomic-field bremsstrahlung, which is known as the external bremsstrahlung (EB), excited by 204Tl and 99Tc ?-emitters in Al, Cu, Cd and Pb targets has been studied. The ? stopper technique is employed to measure the integral intensities above 100 keV energy in different absorber thicknesses. The calculated values were obtained from the bremsstrahlung spectra recorded with different

  13. CCK2\\/gastrin receptor-targeted tumor imaging with (99m)Tc-labeled minigastrin analogs

    Microsoft Academic Search

    Berthold A. Nock; Theodosia Maina; Martin Behe; Anastasia Nikolopoulou; Martin Gotthardt; J. S. Schmitt; Thomas M. Behr; Helmut R. Macke

    2005-01-01

    The aim of this study was to evaluate 3 new (99m)Tc-labeled minigastrin analogs modified with open chain tetraamines at the N-terminus for their suitability in the CCK-2\\/gastrin-R-targeted imaging of tumors (CCK-2\\/gastrin-R = cholecystokinin subtype 2\\/gastrin receptor). METHODS: The [(D)Glu(1)]minigastrin sequence was assembled on the solid support and the respective tetraamine precursors coupled at the N-terminus. Purified peptide conjugates were labeled

  14. Rhenium Uptake, as Analogue for Tc-99, by Steel Corrosion Products

    SciTech Connect

    Krupka, Kenneth M.; Brown, Christopher F.; Schaef, Herbert T.; Heald, Steve M.; Valenta, Michelle M.; Arey, Bruce W.

    2006-04-30

    Static batch experiments were used to examine the sorption of dissolved perrhenate [Re(VII)], as a surrogate for pertechnetate [Tc(VII)], on corrosion products of A-516 carbon steel coupons contacted with synthetic groundwater or dilute water. After 109 days of contact time, the concentration of dissolved Re(VII) in the synthetic groundwater matrix decreased by approximately 26%; the dilute water matrix experienced a 99% decrease in dissolved Re(VII) over the same time period. Bulk XRD results for the corroded steel coupons showed that the corrosion products consisted primarily of maghemite, lepidocrocite, and goethite. Analyses of the coupons by SEM/EDS indicated that Re was present with the morphologically complex assemblages of Fe oxide/hydroxide corrosion products for samples spiked with the highest dissolved Re(VII) concentration (1.0 mmol/L) used for these experiments. Analyses of corroded steel coupons contacted with solutions containing 1.0 mmol/L Re(VII) by synchrotron-based methods confirmed the presence of Re sorbed with the corrosion product on the steel coupons. Analyses showed that the Re sorbed on these corroded coupons was in the +7 oxidation state, suggesting that the Re(VII) uptake mechanism did not involve reduction of Re to a lower oxidation state, such as +4. The results of our studies using Re(VII) as an analogue for Tc(VII)-99 suggest that Tc(VII)-99 would also be sorbed with steel corrosion products and that the inventory of Tc(VII)-99 released from breached waste packages would be lower than what is now conservatively estimated.

  15. EANM procedure guideline for brain perfusion SPECT using 99m Tc-labelled radiopharmaceuticals, version 2

    Microsoft Academic Search

    Özlem L. Kapucu; Flavio Nobili; Andrea Varrone; Jan Booij; Thierry Vander Borght; Kjell Någren; Jacques Darcourt; Klaus Tatsch; Koen J. Van Laere

    2009-01-01

    These guidelines summarize the current views of the European Association of Nuclear Medicine Neuroimaging Committee (ENC).\\u000a The purpose of the guidelines is to assist nuclear medicine practitioners when making recommendations, performing, interpreting,\\u000a and reporting the results of brain perfusion single photon emission computed tomography (SPECT) studies using 99mTc-labelled radiopharmaceuticals. The aim is to achieve a high quality standard for brain

  16. Microstructural zones and tensile characteristics of friction stir welded joint of TC4 titanium alloy

    Microsoft Academic Search

    Hui-jie LIU; Li ZHOU

    2010-01-01

    TC4 titanium alloy was friction stir welded using a W-Re pin tool, and the defect-free weld was produced with proper welding parameters. The joint consists of stir zone, heat affected zone and base material. The stir zone is characterized by equiaxed dynamically recrystallized a phases and transformed ? phases with fine a+? lamellar microstructure. The microstructure of the heat-affected zone

  17. Improved high-Tc superconductor sampler circuits using Josephson transmission line buffers

    Microsoft Academic Search

    Michitaka Maruyama; Mutsuo Hidaka; Tetsuro Satoh

    2003-01-01

    We report on an increase of the measurement bandwidth of a high-Tc superconductor sampler circuit. The circuit composes a waveform measurement system, in which it is cooled by a compact single-stage cryocooler and operates at a temperature of 35-40 K. In the sampler circuit, there exists a sampling jitter due to thermal fluctuation in the critical current of the pulse

  18. Direct angle resolved photoemission spectroscopy and superconductivity of strained high-Tc films

    NASA Astrophysics Data System (ADS)

    Pavuna, Davor; Ariosa, Daniel; Cloetta, Dominique; Cancellieri, Claudia; Abrecht, Mike

    2008-02-01

    Since 1997 we systematically perform direct angle resolved photoemission spectroscopy (ARPES) on in-situ grown thin (<30 nm) cuprate films. Specifically, we probe low-energy electronic structure and properties of high-T_{c} superconductors (HTSC) under different degrees of epitaxial ({compressive vs. tensile}) strain. In overdoped and underdoped in-plane compressed (the strain is induced by the choice of substrate) ?15 nm thin La_{2-x}Sr_{x}CuO_{4} (LSCO) films we almost double T_{c} to 40 K, from 20 K and 24 K, respectively. Yet the Fermi surface (FS) remains essentially two-dimensional. In contrast, ARPES data under {tensile} strain exhibit the dispersion that is three-dimensional, yet T_{c} drastically decreases. It seems that the in-plane compressive strain tends to push the apical oxygen far away from the CuO_{2} plane, enhances the two-dimensional character of the dispersion and increases T_{c}, while the tensile strain acts in the opposite direction and the resulting dispersion is three-dimensional. We have established the shape of the FS for both cases, and all our data are consistent with other ongoing studies, like EXAFS. As the actual lattice of cuprates is like a `Napoleon-cake', i.e. rigid CuO_{2 } planes alternating with softer `reservoir', that distort differently under strain, our data rule out all oversimplified two-dimensional (rigid lattice) mean field models. The work is still in progress on optimized La-doped Bi-2201 films with enhanced T_{c}.

  19. Search for high Tc in layered structures: The case of LiB Matteo Calandra

    E-print Network

    Curtarolo, Stefano

    Search for high Tc in layered structures: The case of LiB Matteo Calandra Institut de Minéralogie devised superconductor MS1-LiB LiB . We calculate the electron-phonon coupling =0.62 and the phonon fre- quency logarithmic average log=54.6 meV and show that the LiB critical temperature is in the range of 10

  20. Deep vein thrombosis detection by 99m TC-MDP scanning

    SciTech Connect

    Moallem, A.; Lichsztral, R.

    1984-08-01

    A new observation is reported wherein 99m Tc-MDP is incorporated into recanalizing thrombophlebitis. In one patient with subacute disease, inflammatory vascularity is appreciated during the first one to two minutes after injection. Both patients showed evidence of late phosphate uptake in their greater saphenous veins two hours later. Intravenous isotope injections may be given in an arm vein: foot injections are not required.

  1. Host responses to live-attenuated Venezuelan equine encephalitis virus (TC-83)

    PubMed Central

    Erwin-Cohen, Rebecca A.; Porter, Aimee I.; Pittman, Phillip R.; Rossi, Cynthia A.; DaSilva, Luis

    2012-01-01

    Venezuelan equine encephalitis virus (VEEV) is a positive-strand RNA Alphavirus endemic in Central and South America, and the causative agent of fatal encephalitis in humans. In an effort to better understand the mechanisms of infection, including differences between people who produce a neutralizing antibody response to the vaccine and those who do not, we performed whole genome transcriptional analysis in human PBMCs exposed in vitro to the live-attenuated vaccine strain of VEEV, TC-83. We compared the molecular responses in cells from three groups of individuals: naïve; previously vaccinated individuals who developed a neutralizing antibody response to the vaccine (responders); and those who did not develop a neutralizing antibody response to the vaccine (nonresponders). Overall, the changes in gene expression were more intense for the naïve group after TC-83 challenge and least potent in the nonresponder group. The main canonical pathways revealed the involvement of interferon and interferon-induced pathways, as well as toll-like receptors TLR- and interleukin (IL)-12-related pathways. HLA class II genotype and suppression of transcript expression for TLR2, TLR4 and TLR8 in the nonresponder group may help explain the lack of vaccine response in this study group. Because TL3 and TLR7 transcripts were elevated in all study groups, these factors may be indicators of the infection and not the immunological state of the individuals. Biomarkers were identified that differentiate between the vaccine responder and the vaccine nonresponder groups. The identified biomarkers were contrasted against transcripts that were unique to the naïve population alone upon induction with TC-83. Biomarker analysis allowed for the discernment between the naïve (innate) responses; the responder (recall) responses; and the nonresponder (alternative) changes to gene transcription that were caused by infection with TC-83. The study also points to the existence of HLA haplotypes that may discriminate between vaccine low- and high-responder phenotypes. PMID:22617845

  2. First results of low frequency electromagnetic wave detector of TC2\\/Double Star program

    Microsoft Academic Search

    J. B. Cao; Z. X. Liu; J. Y. Yang; C. X. Yian; Z. G. Wang; X. H. Zhang; S. R. Wang; S. W. Chen; W. Bian; W. Dong; Z. G. Zhang; F. L. Hua; L. Zhou; N. Cornilleau-Wehrlin; B. de Laporte; M. Parrot; H. Alleyne; K. Yearby; O. Santolík; C. Mazelle

    2005-01-01

    LFEW is a low frequency electromagnetic wave detector mounted on TC-2, which can measure the magnetic fluctuation of low frequency electromagnetic waves. The frequency range is 8 Hz to 10 kHz. LFEW comprises a boom-mounted, three-axis search coil magnetometer, a preamplifier and an electronics box that houses a Digital Spectrum Analyzer. LFEW was calibrated at Chambon-la-Forêt in France. The ground

  3. Cross Domain Automatic Transcription on the TC-STAR EPPS Corpus

    Microsoft Academic Search

    Christian Gollan; Maximilian Bisani; Stephan Kanthak; R. Schluter; Hermann Ney

    2005-01-01

    This paper describes the ongoing development of the British English European Parliament Plenary Session corpus. This corpus will be part of the speech-to-speech translation evaluation infrastructure of the European TC-STAR project. Furthermore, we present first recognition results on the English speech recordings. The transcription system has been derived from an older speech recognition system built for the North-American broadcast news

  4. CROSS DOMAIN AUTOMATIC TRANSCRIPTION ON THE TC-STAR EPPS CORPUS

    Microsoft Academic Search

    Christian Gollan; Maximilian Bisani; Stephan Kanthak; Ralf Schl; Hermann Ney

    1998-01-01

    This paper describes the ongoing development of the British English European Parliament Plenary Session corpus. This corpus will be part of the speech-to-speech translation evaluation infrastructure of the European TC-STAR project. Furthermore, we present first recognition results on the English speech recordings. The transcription system has been derived from an older speech recognition system built for the North-American broadcast news

  5. Single photon emission tomography using 99mTc-HM-PAO in the investigation of dementia

    Microsoft Academic Search

    D Neary; J S Snowden; R A Shields; A W Burjan; B Northen; N MacDermott; M C Prescott; H J Testa

    1987-01-01

    Single photon emission tomographic imaging of the brain using 99mTc HM-PAO was carried out in patients with a clinical diagnosis of Alzheimer's disease, non-Alzheimer frontal-lobe dementia, and progressive supranuclear palsy. Independent assessment of reductions in uptake revealed posterior hemisphere abnormalities in the majority of the Alzheimer group, and selective anterior hemisphere abnormalities in both other groups. The findings were consistent

  6. How to make superconducting-anisotropy least in high-Tc cuprate superconductors

    Microsoft Academic Search

    H. Ihara; A. Iyo; K. Tanaka; K. Tokiwa; K. Ishida; N. Terada; M. Tokumoto; Y. Sekita; T. Tsukamoto; T. Watanabe; M. Umeda

    1997-01-01

    The guiding principles to reduce superconducting-anisotropy were derived for high-Tc cuprate superconductors. Based on the principles, we have attained the least superconducting-anisotropy ?=1.6 for a Cu-based CuBa2Ca3Cu4O12?y (Cu-1234) superconductor. Further lower superconducting-anisotropy has been proposed for Cu-1245 (?=1.3) and Cu-1256 (??1.0) Cu-based superconductors.

  7. Assessing the Potential for In Situ Bioimmobilization of ⁹⁹Tc at the Hanford Site

    Microsoft Academic Search

    Philip E. Long; James K. Fredrickson; Thomas M. Gihring; Shu-mei W. Li; Andres E. Plymale; John M. Zachara

    2004-01-01

    Microorganisms, either directly or indirectly, can alter the oxidation states of uranium and technetium resulting in their precipitation as sparingly soluble solid-phases. This process, in concept, can render these contaminants immobile for long time periods. ⁹⁹Tc is a radionuclide that contributes significantly to estimates of future human health risk at the Hanford Site because of its longevity and mobility in

  8. Enhanced Fidelity of 3TC-Selected Mutant HIV1 Reverse Transcriptase

    Microsoft Academic Search

    Mark A. Wainberg; William C. Drosopoulos; Horacio Salomon; Mayla Hsu; Gadi Borkow; Michael A. Parniak; Zhengxian Gu; Qingbin Song; Jayanthi Manne; Sabina Islam; Gino Castriota; Vinayaka R. Prasad

    1996-01-01

    Monotherapy with (-)2',3'-dideoxy-3'-thiacytidine (3TC) leads to the appearance of a drug-resistant variant of human immunodeficiency virus-type 1 (HIV-1) with the methionine-184 --> valine (M184V) substitution in the reverse transcriptase (RT). Despite resulting drug resistance, treatment for more than 48 weeks is associated with a lower plasma viral burden than that at baseline. Studies to investigate this apparent contradiction revealed the

  9. Myocardial kinetics of Tc99m glucarate in low flow, hypoxia, and aglycemia

    Microsoft Academic Search

    D. R. Okada; G. Johnson III; Z. Liu; S. D. Hocherman; B. A. Khaw; K. Y. Pak; R. D. Okada

    2003-01-01

    Background  Technetium-99m glucarate is a myocardial infarct-avid imaging agent. Recent conflicting and inconclusive reports have suggested\\u000a that the agent may be taken up by ischemic but viable myocardium. The purposes of this study were (1) to determine conclusively\\u000a whether there is Tc-99m glucarate uptake in ischemic viable myocardium and (2) to investigate the potential mechanisms for\\u000a such uptake by studying components

  10. Hall effect and resistivity in high-Tc superconductors: The conserving approximation

    Microsoft Academic Search

    Hiroshi Kontani; Kazuki Kanki; Kazuo Ueda

    1999-01-01

    The Hall coefficient RH in high-Tc cuprates in the normal state shows the striking non-Fermi-liquid behavior: RH follows a Curie-Weiss type temperature dependence and \\\\|RH\\\\|>>1\\/\\\\|ne\\\\| at low temperatures in the underdoped compounds. Moreover, RH is positive for hole-doped compounds and negative for electron-doped ones, although each of them has a similar holelike Fermi surface. In this paper, we give the

  11. Active brazing carbon\\/carbon composite to TC4 with Cu and Mo composite interlayers

    Microsoft Academic Search

    Youqiong Qin; Jicai Feng

    2009-01-01

    Active filler metal (TiZrNiCu) was used to increase the wettability and Cu and Mo composite interlayers were added to release residual stress and increase the mechanical properties of TC4–C\\/C composite joints. The mechanical properties of the brazed joints were measured by shear strength testing. The effects of brazing parameters on the microstructures of the brazed joint were investigated by SEM,

  12. Topology of SU(N) gauge theories at T=0 and T=Tc

    E-print Network

    Biagio Lucini; Michael Teper; Urs Wenger

    2004-01-20

    We calculate the topological charge density of SU(N) lattice gauge fields for values of N up to N=8. Our T=0 topological susceptibility appears to approach a finite non-zero limit at N=infinity that is consistent with earlier extrapolations from smaller values of N. Near the deconfining temperature Tc we are able to investigate separately the confined and deconfined phases, since the transition is quite strongly first order. We find that the topological susceptibility of the confined phase is always very similar to that at T=0. By contrast, in the deconfined phase at larger N there are no topological fluctuations except for rare, isolated and small instantons. This shows that as N->infinity the large-T suppression of large instantons and the large-N suppression of small instantons overlap, even at T=Tc, so as to suppress all topological fluctuations in the deconfined phase. In the confined phase by contrast, the size distribution is much the same at all T, becoming more peaked as N grows, suggesting that D(rho) is proportional to a delta function at N=infinity, centered on rho close to 1/Tc.

  13. Evaluation of peritoneovenous shunt patency with Tc-99m labeled microspheres

    SciTech Connect

    Madeddu, G.; D'Ovidio, N.G.; Casu, A.R.; Mura, R.; Costanza, C.; Lai, N.; LeVeen, H.H.

    1983-04-01

    The LeVeen peritoneovenous shunt (PVS) was investigated in 40 cirrhotic patients with refractory ascites. Five millicuries of Tc-99m-tagged human albumin microspheres (15-36 microns) were injected into the peritoneal cavity between the umbilicus and the left anterior superior iliac spine. The radiotracer was always detectable by scintigram in the lungs when the shunt was patent. In case of malfunction, by contrast, the radioactivity was either restricted to the venous tube or confined below the diaphragm for at least 4 hr. In the presence of complete obstruction, whereas the tube was not visualized after peritoneal injection, it was outlined by direct injection of 2 mCi of Tc-99m albumin microspheres into its subcutaneous tract, where it crossed the 12th rib, immediately above the valve. This technique sufficed to establish whether the site of obstruction was at the valve or in the tubing itself. In one patient, poor visualization of the tube and a delayed image of the lungs was caused by partial occlusion of the valve with fibrinoid debris. This radiotracer method proved simple, quick, and led to an immediate selective replacement when the shunt was not patent. Therefore, the use of this test is recommended for a definitive diagnosis, since there were neither false negatives nor false positives. No complications such as embolism or bacterial infection were encountered with Tc-99m human albumin microspheres, which are excellent tracers.

  14. Effect of raised thoracic pressure and volume on 99mTc-DTPA clearance in humans

    SciTech Connect

    Nolop, K.B.; Maxwell, D.L.; Royston, D.; Hughes, J.M.

    1986-05-01

    Although positive airway pressure is often used to treat acute pulmonary edema, the effects on epithelial solute flux are not well known. We measured independently the effect of 1) positive pressure and 2) voluntary hyperinflation on the clearance of inhaled technetium-99m-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc-DTPA) in six nonsmokers and six smokers. Lung volumes were monitored by inductance plethysmography. Each subject was studied in four situations: 1) low end-expiratory volume (LO-), 2) low volume plus 9 cmH2O continuous positive airway pressure (LO+), 3) high end-expiratory volume (HI-), and 4) high volume plus continuous positive airway pressure (HI+). The clearance half time of 99mTc-DTPA for the nonsmokers decreased from 64.8 +/- 7.0 min (mean +/- SE) at LO- to 23.2 +/- 5.3 min at HI- (P less than 0.05). Positive pressure had no synergistic effect. The mean clearance half time for the smokers was faster than nonsmokers at base line but unaffected by similar changes in thoracic volume and pressure. We conclude that, in nonsmokers, positive airway pressure increases /sup 99m/Tc-DTPA clearance primarily through an increase in lung volume and that smokers are immune to these effects.

  15. Tc-99m galactosyl-neoglycoalbumin: in vitro characterization of receptor-mediated binding

    SciTech Connect

    Vera, D.R.; Krohn, K.A.; Stadalnik, R.C.; Scheibe, P.O.

    1984-07-01

    Hepatic binding protein (HBP) is a membrane receptor that binds and transports plasma glycoproteins from hepatic blood to hepatocellular lysosomes. A characterization is made of the in vitro binding of Tc-99m galactosyl-neoglycoalbumin (Tc-NGA), a synthetic HBP ligand, to liver membrane. Structural modifications of NGA resulted in the alteration of the equilibrium constant, KA, and the forward-binding rate constant, kb. Binding was second-order; the relative amount of membrane-bound NGA depended on the initial concentrations of ligand and membrane. Membrane displacement studies, using carrier ligands in contrast to previously bound Tc-NGA or I-NGA, correlated with the binding characteristics of a native HBP ligand, asialo-orosomucoid. Computer simulation was used to study the detectability of the changes in HBP concentration at different values of kb. The simulations indicated that radiopharmacokinetic sensitivity to alterations in (HBP) should be possible using a neoglycoalbumin preparation with a carbohydrate density within the range of 15 to 25 galactose units per albumin molecule.

  16. Separation, isolation and partial characterization of Tc(Sn) MDP complexes

    SciTech Connect

    McCullough, R.W.; Sheff, M.F.; Tyson, I.B.; Campbell, M.L.

    1984-01-01

    Heretofore only HPLC has been used to successfully separate commercial Tc(Sn)MDP complexes with high resolution. Using two alternate chromatographic systems, hydroxyapatite (Biogel HTP) and polyarcylamide gels (Biogel P2, P4, P10) at various temperatures (5/sup 0/, 25/sup 0/, 35/sup 0/C), the authors are able to reproducibly demonstrate the presence of 10 different Tc-labelled complexes. Their approximate MW sizes based on column calibration with water soluble organic dyes, are as follows: I,1250; II,1160; III,1060; IV,960; V,860; VI,820; VII,790; VIII,610; IX,510; X,450; XI,350. These complexes were related in a series of temperature-dependent equilibria. That these components are associated with MDP as a ligand was borne out by the fact that base hydrolysis with NaOH yielded products having IR and NMR spectra identical to the similarly treated MDP ligand. Ongoing efforts to isolate and characterize these complexes include coordination compound complexation reactions, derivative formation experiments and a variety of precipitation studies. Successful completion of this work would advance the understanding of the chemistry of Tc complexes and thereby assist in formulating the conditions under which specific complexes can be prepared for imaging bone.

  17. Magnetic interaction in hole-doped high- Tc superconductors observed by angle-resolved photoemission spectroscopy

    NASA Astrophysics Data System (ADS)

    Sato, T.; Matsui, H.; Terashima, K.; Takahashi, T.; Ding, H.; Yang, H.-B.; Wang, S.-C.; Fujii, T.; Watanabe, T.; Matsuda, A.; Terashima, T.; Kadowaki, K.

    2004-10-01

    We have performed a high-resolution angle-resolved photoemission spectroscopy (ARPES) on high- Tc superconductors (HTSCs) Bi 2Sr 2Ca n-1 Cu nO 2 n+4 ( n=1-3) to study the systematics of the electronic structure and the origin of many-body interactions responsible for superconductivity. We find that a large hole-like Fermi surface and d-wave superconducting gap are generic features of Bi-based HTSCs. For n=2 and 3, a sudden change in the energy dispersion, so-called “kink”, becomes pronounced on approaching (?,0) in the superconducting state, while a kink appears only around the nodal direction in the normal state. The kink around (?,0) disappears at Tc. For n=1, the kink shows no significant temperature dependence even across Tc. This could suggest that the coupling of electrons with Q=(?,?) magnetic mode is dominant in the superconducting state for multi-layered cuprates, while the interaction at the normal state and that of single-layered cuprates have a different origin.

  18. The value of 99m-Tc-HMPAO Diamox SPECT in carotid artery stenosis

    SciTech Connect

    Rehmann, C.J.; Limburg, M.; Blok, L.M. [Univ. of Amsterdam (Netherlands)] [and others

    1994-05-01

    In this prospective study, brain perfusion reserve was evaluated by Acetazolamide (Diamox) 99m-Tc-HMPAO SPECT in patients clinically suspected for carotid artery stenosis. Consecutive 99m-Tc-HMPAO brain-SPECT investigations were obtained within one hour before and after a dose of 1000 mg Acetazolamide i.v. Studies were performed with a SME 810 multidetector neuroSPECT system. After reconstruction mean counts in the parieto-temporal region were calculated on fixed regions of interest (ROI`s) in two slices. The calculated activity was corrected for injected dose 99m-Tc-HMPAO and decay. The corrected counts of the baseline study were subtracted from the post-Diamox study. The increase of perfusion was expressed as a percentage of the baseline results in the same ROI. Fifteen studies were performed in 14 patients, 3 women and 11 men, mean age 67 years, range 44-78 years. One patient was excluded because the quality of labelling was not assessed. The results of 14 studies (28 carotid arteries) were used for statistical analysis. A carotid stenosis was considered to be significant above 70% (Duplex sonography of angiography).

  19. Hydrostatic pressure induced transition from ?TC to ?? pinning mechanism in MgB2

    NASA Astrophysics Data System (ADS)

    Shabbir, Babar; Wang, X. L.; Ghorbani, S. R.; Dou, S. X.; Xiang, Feixiang

    2015-05-01

    The impact of hydrostatic pressure up to 1.2 GPa on the critical current density (Jc) and the nature of the pinning mechanism in MgB2 have been investigated within the framework of the collective theory. We found that the hydrostatic pressure can induce a transition from the regime where pinning is controlled by spatial variation in the critical transition temperature (? {{T}c}) to the regime controlled by spatial variation in the mean free path (? \\ell ). Furthermore, critical temperature (Tc) and low field Jc are slightly reduced, although the Jc drops more quickly at high fields than at ambient pressure. We found that the pressure raises the anisotropy and reduces the coherence length, resulting in weak interaction of the vortex cores with the pinning centres. Moreover, the hydrostatic pressure can reduce the density of states [Ns(E)], which, in turn, leads to a reduction in the Tc from 39.7 K at P = 0 GPa to 37.7 K at P = 1.2 GPa.

  20. Synthesis and identification of the monocation Tc(CPI) sub 6 sup + in Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and its hydrolysis products. [Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and monocation Tc(CPI) sub 6 sup +

    SciTech Connect

    Kronauge, J.F.; Davison, A.; Roseberry, A.M.; Costello, C.E.; Maleknia, S. (Massachusetts Inst. of Tech., Cambridge (United States)); Jones, A.G. (Harvard Medical School and Brigham and Women's Hospital, Boston, MA (United States))

    1991-10-30

    The complex Tc(CNC(CH{sub 3}){sub 2}COOCH{sub 3}){sub 6}Cl (cation designated as Tc(CPI){sub 6}{sup +}) is one of a series of isonitrile-coordinated technetium complexes being investigated as a prototype radiopharmaceutical to evaluate myocardial perfusion. It has been prepared from the pertechnetate ion by aqueous Na{sub 2}S{sub 2}O{sub 4} reduction in the presence of the functionalized isocyanide ligand. The octahedral compound with its relatively reactive ester substituents is stable under aqueous aerobic conditions within the pH range 5-7. At high pH, however, the ester moieties undergo random, base-catalyzed hydrolysis while the six ligands remain coordinated in a fixed geometry to the central metal. The nine predicted carboxylic acid containing species were separated and identified by RP-HPLC, FAB-MS, IR, and {sup 99}Tc NMR methods. Specific k' values obtained from the RP-HPLC of these characterized compounds were used to identify technetium containing metabolites of the radiopharmaceutical. Varying rates of in vitro enzymatic hydrolysis at the terminal ester moieties of the coordinated ligands were shown to occur when this compound was incubated with blood serum from different animal species.

  1. Automation of ??Tc extraction by LOV prior ICP-MS detection: application to environmental samples.

    PubMed

    Rodríguez, Rogelio; Leal, Luz; Miranda, Silvia; Ferrer, Laura; Avivar, Jessica; García, Ariel; Cerdà, Víctor

    2015-02-01

    A new, fast, automated and inexpensive sample pre-treatment method for (99)Tc determination by inductively coupled plasma-mass spectrometry (ICP-MS) detection is presented. The miniaturized approach is based on a lab-on-valve (LOV) system, allowing automatic separation and preconcentration of (99)Tc. Selectivity is provided by the solid phase extraction system used (TEVA resin) which retains selectively pertechnetate ion in diluted nitric acid solution. The proposed system has some advantages such as minimization of sample handling, reduction of reagents volume, improvement of intermediate precision and sample throughput, offering a significant decrease of both time and cost per analysis in comparison to other flow techniques and batch methods. The proposed LOV system has been successfully applied to different samples of environmental interest (water and soil) with satisfactory recoveries, between 94% and 98%. The detection limit (LOD) of the developed method is 0.005 ng. The high durability of the resin and its low amount (32 mg), its good intermediate precision (RSD 3.8%) and repeatability (RSD 2%) and its high extraction frequency (up to 5 h(-1)) makes this method an inexpensive, high precision and fast tool for monitoring (99)Tc in environmental samples. PMID:25435232

  2. /sup 99m/Tc RBC scintigraphy: correlation of gastrointestinal bleeding rates with scintigraphic findings

    SciTech Connect

    Smith, R.; Copely, D.J.; Bolen, F.H.

    1987-05-01

    In 62 consecutive patients, /sup 99m/Tc RBC studies were reviewed and the scintigraphic findings were characterized to determine the ability of /sup 99m/Tc RBC scintigraphy to estimate bleeding rates in patients with active gastrointestinal hemorrhage. Of the 62 scans, 10 showed early positivity (less than 1 hr) with a strongly intense bleeding focus relative to hepatic activity (group 1), four showed delayed positivity (greater than 1 hr) with a strong focus (group 2), five showed early positivity with a weak focus (group 3), 12 showed delayed positivity with a weak focus (group 4), and 31 studies were negative (group 5). The mean bleeding rates were then calculated by dividing the blood transfusion volume requirements by the duration of active bleeding for each patient, as recorded in the patients' charts. The mean bleeding rates for these groups were 0.4, 0.3, 0.2, 0.15, and 0.1 ml/min, respectively. Group 1 patients had the greatest mean blood-volume loss, longest duration of active bleeding, and highest mean bleeding rate, and they required more aggressive therapy than the other groups. The minimum mean bleeding rate detectable by scintigraphy was 0.1 ml/min. Our results suggest that /sup 99m/Tc RBC scintigraphy can estimate bleeding rates and identify those patients who are at higher risk for developing massive gastrointestinal hemorrhage requiring more aggressive therapy.

  3. Synthesis and biological evaluation of bisphosphonate compound labeled with (99m)Tc(CO)3(+).

    PubMed

    ?enocak, Kamile; Teksöz, Serap; ?çhedef, Çi?dem; Uçar, Eser

    2015-03-01

    In this study, radiolabeling of a bisphosphonate, alendronate (Alendronate sodium), was performed with the help of a bifunctional chelating agent. For that purpose, DTPA-NHS (Diethylenetriaminepentaacetic acid dianhydride-N-hydroxysuccinimide) was synthesized with an esterification between DTPA and NHS. Combining the DTPA-NHS ester with alendronate yields the DTPA-Alendronate compound. The structure of synthesized compound was analyzed by (1) H/(13) C/(31) P-NMR and HPLC. After then, the labeling with [(99m) Tc(CO)3 ](+) core of synthesized compound was provided. Performing quality controls of newly synthesized [(99m) Tc(CO)3 -DTPA-Alendronate] complex with thin layer radiochromatography (TLRC) and high-performance liquid radiochromatography (HPLRC), the labeling yield was found as 99%. It was observed that the compound conserves its stability for 24 h in serum media. Biodistribution of the radiolabeled complex was performed on Wistar Albino rats to determine radiopharmaceutical potential of the [(99m) Tc(CO)3 -DTPA-Alendronate] complex. It is thought that the data gained from this study will contribute to the development of complexes with bisphosphonate. PMID:25092179

  4. Hall effect and resistivity in high-Tc superconductors: The conserving approximation

    NASA Astrophysics Data System (ADS)

    Kontani, Hiroshi; Kanki, Kazuki; Ueda, Kazuo

    1999-06-01

    The Hall coefficient RH in high-Tc cuprates in the normal state shows the striking non-Fermi-liquid behavior: RH follows a Curie-Weiss type temperature dependence and \\|RH\\|>>1/\\|ne\\| at low temperatures in the underdoped compounds. Moreover, RH is positive for hole-doped compounds and negative for electron-doped ones, although each of them has a similar holelike Fermi surface. In this paper, we give the explanation of this long-standing problem from the standpoint of the nearly antiferromagnetic (AF) Fermi liquid. We consider seriously the vertex corrections for the current which are indispensable to satisfy the conservation laws, which are violated within the conventional Boltzmann transport approximation. The obtained total current J-->k takes an enhanced value and is no longer perpendicular to the Fermi surface due to the strong AF fluctuations. By virtue of this mechanism, the anomalous behaviors of RH in high-Tc cuprates are naturally explained. Both the temperature and the (electron, hole) doping dependences of RH in high-Tc cuprates are reproduced well by numerical calculations based on the fluctuation-exchange approximation, applied to the single-band Hubbard model with a holelike Fermi surface. We also discuss the singular temperature dependence of RH in other nearly AF metals, e.g., V2O3, ?-BEDT-TTF organic superconductors, and heavy fermion systems close to the AF phase boundary.

  5. Novel Approach to Prepare {sup 99m}Tc-Based Multivalent RGD Peptides

    SciTech Connect

    Shuang Liu

    2012-10-24

    This project presents a novel approach to prepare the {sup 99m}Tc-bridged multivalent RGD (arginine-glycine-aspartate) peptides. This project will focus on fundamentals of {sup 99m}Tc radiochemistry. The main objective of this project is to demonstrate the proof-of-principle for the proposed radiotracers. Once a kit formulation is developed for preparation of the {sup 99m}Tc-bridged multivalent RGD peptides, various tumor-bearing animal models will be used to evaluate their potential for SPECT (single photon-emission computed tomography) imaging of cancer. We have demonstrated that (1) multimerization of cyclic RGD peptides enhances the integrin {alpha}{sub v}{beta}{sub 3} bonding affinity and radiotracer tumor uptake; (2) addition of G{sub 3} or PEG{sub 4} linkers makes it possible for two RGD motifs in 3P-RGD{sub 2} and 3G-RGD{sub 2} to achieve simultaneous integrin {alpha}{sub v}{beta}{sub 3} binding; and (3) multimers are actually bivalent (not multivalent), the presence of extra RGD motifs can enhance the tumor retention time of the radiotracer.

  6. Characteristics of Tc and ?(T) of polycrystalline (In2O3)-(ZnO) films with low carrier density

    NASA Astrophysics Data System (ADS)

    B, Shinozaki; S, Takada; N, Kokubo; K, Makise; T, Asano; K, Yamada; K, Yano; H, Nakamura

    2012-12-01

    For the polycrystalline (In2O3)-(ZnO) prepared by annealing in air, we investigated the relation among superconductivity, ?(T) characteristics and preparation conditions. To clarify the distribution of elements, we studied the microstructure by scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). It was found that 1) The films annealed at restricted regions of annealing temperature Ta and time ta show the superconductivity. Transition temperature TC and carrier density n are Tc<3.3K and n asymp1025/m3~1026/m3, respectively. 2) The data on EELS spectra mapping of indium plasmon indicate that droplets of the pure indium phase distribute discretely on grain boundaries and near the interface between the film and the glass substrate. 3) Although data in the Tc - Ta relation are scattered, the TC shows relatively good correlation with n, taking a convex form.

  7. Infrared detection with high-[Tc] bolometers and response of Nb tunnel junctions to picosecond voltage pulses

    SciTech Connect

    Verghese, S.

    1993-05-01

    Oxide superconductors with high critical temperature [Tc] make sensitive thermometers for several types of infrared bolometers. The authors built composite bolometers with YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta

  8. PUBLISHED ONLINE: 21 DECEMBER 2008 DOI: 10.1038/NPHYS1159 Energy gaps in the failed high-Tc superconductor

    E-print Network

    Loss, Daniel

    ,4 , Masaki Fujita5 , Tadashi Adachi6 , Norman Mannella1,2 *, Kazuyoshi Yamada5 , Yoji Koike6 , Zahid Hussain2 high-Tc superconductor that involves a possible precursor-pairing energy scale around the node

  9. Technetium Tc 99m diphosphonate bone scan. False-normal findings in elderly patients with hematogenous vertebral osteomyelitis

    SciTech Connect

    Schlaeffer, F.; Mikolich, D.J.; Mates, S.M.

    1987-11-01

    Hematogenous osteomyelitis is usually diagnosed by an abnormal technetium Tc 99m diphosphonate bone scan in symptomatic patients who have positive blood cultures. False-normal 99mTc bone scans have been described recently in neonates with biopsy-proved osteomyelitis. This phenomenon seems to be extremely rare in adults. Two elderly patients with hematogenous vertebral osteomyelitis had normal technetium Tc 99m diphosphonate bone scans when first evaluated. In both cases the bone scans became abnormal four to six weeks after onset of symptoms and two to four weeks after the initial normal results of the study. When suggested by the clinical picture, hematogenous osteomyelitis cannot be ruled out by a normal 99mTc bone scan at any age. Gallium scan, computed tomographic scan, or bone biopsy can be helpful in such cases.

  10. (99m)Tc-amitrole as a novel selective imaging probe for solid tumor: In silico and preclinical pharmacological study.

    PubMed

    Essa, B M; Sakr, T M; Khedr, Mohammed A; El-Essawy, F A; El-Mohty, A A

    2015-08-30

    Lactoperoxidase (LPO) inhibitors are very selective for solid tumor due to their high binding affinity to the LPO enzyme. A computational study was used to select top-ranked LPO inhibitor (alone and in complex with (99m)Tc) with high in silico affinity. The novel prepared (99m)Tc-amitrole complex demonstrated both in silico and in vivo high affinity toward solid tumors.(99m)Tc-amitrole was radio-synthesized with a high radiochemical yield (89.7±3.25). It showed in vitro stability for up to 6h. Its preclinical evaluation in solid tumor-bearing mice showed high retention and biological accumulation in solid tumor cells with a high Target/Non-Target (T/NT) ratio equal to 4.9 at 60min post-injection. The data described previously could recommend (99m)Tc-amitrole as potential targeting scintigraphic probe for solid tumor imaging. PMID:25956074

  11. Saving the "Lost Generation"

    ERIC Educational Resources Information Center

    Beebe, Anthony E.

    2007-01-01

    Since the beginning of the American experience, labels have been used to describe generations. Among them are the "Puritan generation," the "greatest generation," the "baby boomer generation" and the "MTV generation." Today, people are creating a new generation--the "lost generation." The lost generation represents a large and growing population…

  12. Nonenzymatic Direct Assay of Hydrogen Peroxide at Neutral pH Using the Eu 3 Tc Fluorescent Probe

    Microsoft Academic Search

    Axel Dürkop; Otto S. Wolfbeis

    2005-01-01

    A detailed study is presented on the use of an easily accessible probe (the europium–tetracycline 3:1 complex; referred to\\u000a as Eu3Tc) for determination of hydrogen peroxide (HP). Eu3Tc undergoes a 15-fold increase in luminescence intensity on exposure to an excess of HP. Data are given on the time dependence\\u000a of the reaction, on the pH dependence of the absorption and

  13. Molecular characterization of Cyclophilin (TcCyP19) in Trypanosoma cruzi populations susceptible and resistant to benznidazole.

    PubMed

    Rêgo, Juciane Vaz; Duarte, Ana Paula; Liarte, Daniel Barbosa; de Carvalho Sousa, Francirlene; Barreto, Humberto Medeiros; Bua, Jacqueline; Romanha, Alvaro José; Rádis-Baptista, Gandhi; Murta, Silvane Maria Fonseca

    2015-01-01

    Cyclophilin (CyP), a peptidyl-prolyl cis/trans isomerase, is a key molecule with diverse biological functions that include roles in molecular chaperoning, stress response, immune modulation, and signal transduction. In this respect, CyP could serve as a potential drug target in disease-causing parasites. Previous studies employing proteomics techniques have shown that the TcCyP19 isoform was more abundant in a benznidazole (BZ)-resistant Trypanosoma cruzi population than in its susceptible counterpart. In this study, TcCyP19 has been characterized in BZ-susceptible and BZ-resistant T.?cruzi populations. Phylogenetic analysis revealed a clear dichotomy between Cyphophilin A (CyPA) sequences from trypanosomatids and mammals. Sequencing analysis revealed that the amino acid sequences of TcCyP19 were identical among the T.?cruzi samples analyzed. Southern blot analysis showed that TcCyP19 is a single-copy gene, located in chromosomal bands varying in size from 0.68 to 2.2?Mb, depending on the strain of T.?cruzi. Northern blot and qPCR indicated that the levels of TcCyP19 mRNA were twofold higher in drug-resistant T.?cruzi populations than in their drug-susceptible counterparts. Similarly, as determined by two-dimensional gel electrophoresis immunoblot, the expression of TcCyP19 protein was increased to the same degree in BZ-resistant T.?cruzi populations. No differences in TcCyP19 mRNA and protein expression levels were observed between the susceptible and the naturally resistant T.?cruzi strains analyzed. Taken together, these data indicate that cyclophilin TcCyP19 expression is up-regulated at both transcriptional and translational levels in T.?cruzi populations that were in vitro-induced and in vivo-selected for resistance to BZ. PMID:25450774

  14. The discovery of robust magnetism in a technetium oxide: The structure of CaTcO3

    SciTech Connect

    Avdeev, Maxim [Bragg Institute, ANSTO; Thorogood, Gordon J. [Bragg Institute, ANSTO; Carter, Melody L. [ANSTO; Kennedy, Brendan J. [University of Technology Sydney; Ting, Jimmy [University of Sydney, Australia; Singh, David J [ORNL; Wallwork, Kia S. [Australian Synchrotron

    2011-01-01

    The technetium perovskite CaTcO{sub 3} has been synthesized. Combining synchrotron X-ray and neutron diffraction, we found that CaTcO{sub 3} is an antiferromagnetic with a surprisingly high Neel temperature of 800 K. The transition to the magnetic state does not involve a structural change, but there is obvious magnetostriction. Electronic structure calculations confirm the experimental results.

  15. 99m Tc(CO) 3 -tosufloxacin dithiocarbamate complexation and radiobiological evaluation in male Wister rat model

    Microsoft Academic Search

    Syed Qaiser Shah; Muhammad Rafiullah Khan

    2011-01-01

    In the current investigation tosufloxacin (TSN) was derivatized to its dithiocarbamate (TSND) derivative and its radiolabeling\\u000a with technetium-99m using [99mTc(CO)3(H2O)3]+ precursor. The labeled TSND (99mTc(CO)3-TSND) was radiochemically characterized in saline and serum and biologically its in vitro binding with Proteus mirabilis (P. mirabilis) and biodistribution in male Wister rats (MWR) artificially infected with live and heat killed P. mirabilis. Radiochemically

  16. Distribution of 99 Tc and 129 I in the vicinity of underground nuclear tests at the Nevada Test Site

    Microsoft Academic Search

    P. Zhao; Q. Hu; T. P. Rose; G. J. Nimz; M. Zavarin

    2008-01-01

    99Tc and 129I are important contributors to risk assessment due to their long half-lives and high mobility as aqueous anionic species.\\u000a We analyzed 99Tc and 129I in groundwater samples in and near 11 underground nuclear tests and in melt glass and rock samples retrieved from the Chancellor\\u000a test cavity, Nevada Test Site. The 129I\\/127I ratio ranges from 10?3 to 10?6

  17. 99m Tc-Tagged chicken liver as a marker of solid food in the human stomach

    Microsoft Academic Search

    J. H. Meyer; I. L. MacGregor; R. Gueller; P. Martin; R. Cavalieri

    1976-01-01

    Past measurement of gastric emptying of solid food in man has depended on external counting of surface-absorbed isotopes without verification that isotopic labels remain attached to solid food in the stomach. In this study chicken liver was isotopically labeled with99mTc incorporated uniformly and intracellularly throughout the liver substance.In vitro studies showed less than 10% loss of99mTc from liver incubated with

  18. Early assessment of skeletal muscle damage after ischaemia-reperfusion injury using Tc99m-glucarate

    Microsoft Academic Search

    A. M Wiersema; W. J. G Oyen; R Dirksen; A. A. J Verhofstad; F. H. M Corstens; J. A van der Vliet

    2000-01-01

    Purpose: After acute arterial obstruction of the lower extremity, muscle damage is the critical determinant for clinical outcome. The extent of muscle damage and limb viability are currently assessed by clinical examination, which is inaccurate. Tc-99m-pyrophosphate (PYP) has been applied for imaging ischaemia-reperfusion damage. More recently, a new imaging agent, Tc-99m-glucarate (GLUC), was introduced for delineating early myocardial infarction after

  19. New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

    SciTech Connect

    Rogers, R.D.; Bond, A.H.; Zhang, Jianhua [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Horwitz, P. [Argonne National Lab., IL (United States)

    1995-12-31

    Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.

  20. Can Indian Ocean SST variability impact TC activity in the South Pacific? A Spatial Analysis

    NASA Astrophysics Data System (ADS)

    Magee, Andrew D.; Verdon-Kidd, Danielle C.; Kiem, Anthony S.

    2015-04-01

    Tropical Cyclones (TCs) represent a significant natural hazard to the 15 island nations and 2.7 million inhabitants of the South Pacific, accounting for 76% of reported disasters in the region since 1950. This vast area, dominated by the coupled ocean-atmosphere interactions of the South Pacific fuels the highly variable nature of TCs (both spatially and temporally), leading to difficulties in planning for and responding to these extreme events. While it is well known that the El Niño/Southern Oscillation (ENSO) plays a significant role in modulating the background state on which TCs form, there are other large-scale climate drivers operating on annual timescales or longer within the South Pacific (e.g. ENSO Modoki and the Interdecadal Pacific Oscillation) and outside the Pacific Basin (e.g. the Indian Ocean Dipole and the Southern Annular Mode) that may also influence TC formation. In response to this issue, the impact of these large-scale climate drivers upon the spatial characteristics of tropical cyclogenesis is assessed for the South Pacific region (5o-35oS, 145oE-130oW) over a 67-year period (1945-2011). It is shown, that in addition to the impact of 'Pacific-centric' climate drivers, eastern Indian Ocean sea surface temperatures significantly impact the spatial characteristics of tropical cyclogenesis in the South Pacific. In particular, warming (cooling) in the eastern Indian Ocean is found to result in an eastward (westward) shift in the average location of tropical cyclogenesis in the South Pacific (up to 712km between extreme phases). One mechanism that may account for this east/west modulation of TC activity in the South Pacific is the propagation of warmer water from the Timor Sea through the Coral Sea to the Pacific, resulting in a strengthening of the Pacific Warm Pool and associated meteorological characteristics connected with tropical cyclogenesis. Understanding how other large-scale climate modes interact with Indian Ocean processes is important in producing a 'real-life' climatology of TCs for the region. As such, when Indian Ocean SST variability is coupled with other drivers, for example, ENSO, significant amplification of TC activity is found; up to 1540km to the east of the overall mean centre of cyclogenesis. Given the extreme impacts of TCs, any improvements in the understanding of what causes the spatial variability of TC formation may help TC forecasting methods for the region, in turn improving disaster risk management and preparedness for the nations of the South Pacific.