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Sample records for tc generators sintesis

  1. Rapamycin generates anti-apoptotic human Th1/Tc1 cells via autophagy for induction of xenogeneic GVHD

    PubMed Central

    Amarnath, Shoba; Flomerfelt, Francis A.; Costanzo, Carliann M.; Foley, Jason E.; Mariotti, Jacopo; Konecki, Daniel M.; Gangopadhyay, Anu; Eckhaus, Michael; Wong, Susan; Levine, Bruce L.; June, Carl H.; Fowler, Daniel H.

    2013-01-01

    Murine T cells exposed to rapamycin maintain flexibility towards Th1/Tc1 differentiation, thereby indicating that rapamycin promotion of regulatory T cells (Tregs) is conditional. The degree to which rapamycin might inhibit human Th1/Tc1 differentiation has not been evaluated. In the presence of rapamycin, T cell costimulation and polarization with IL-12 or IFN? permitted human CD4+ and CD8+ T cell differentiation towards a Th1/Tc1 phenotype; activation of STAT1 and STAT4 pathways essential for Th1/Tc1 polarity was preserved during mTOR blockade but instead abrogated by PI3 kinase inhibition. Such rapamycin-resistant human Th1/Tc1 cells: (1) were generated through autophagy (increased LC3BII expression; phenotype reversion by autophagy inhibition via 3-MA or siRNA for Beclin 1); (2) expressed anti-apoptotic bcl-2 family members (reduced Bax, Bak; increased phospho-Bad); (3) maintained mitochondrial membrane potentials; and (4) displayed reduced apoptosis. In vivo, type I polarized and rapamycin-resistant human T cells caused increased xenogeneic graft-versus-host disease (x-GVHD). Murine recipients of rapamycin-resistant human Th1/Tc1 cells had: (1) persistent T cell engraftment; (2) increased T cell cytokine and cytolytic effector function; and (3) T cell infiltration of skin, gut and liver. Rapamycin therefore does not impair human T cell capacity for type I differentiation. Rather, rapamycin yields an anti-apoptotic Th1/Tc1 effector phenotype by promoting autophagy. PMID:20404486

  2. 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.

  3. 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.

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

    DOEpatents

    Bennett, R.G.; Christian, J.D.; Kirkham, R.J.; Tranter, T.J.

    1998-09-01

    An improved method is described 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. 1 fig.

  5. Development and production of second generation high Tc superconducting tapes at SuperOx and first tests of model cables

    NASA Astrophysics Data System (ADS)

    Lee, S.; Petrykin, V.; Molodyk, A.; Samoilenkov, S.; Kaul, A.; Vavilov, A.; Vysotsky, V.; Fetisov, S.

    2014-04-01

    The SuperOx and SuperOx Japan LLC companies were founded with the goal of developing a cost-effective technology for second generation HTS (2G HTS) tapes by utilizing a combination of the most advanced chemical and physical deposition techniques, together with implementing original tape architectures. In this paper we present a brief overview of our production and experimental facilities and recent results of 2G HTS tape fabrication, and describe the first tests of the tapes in model cables for AC and DC power application.

  6. Study of the radiation effect of (99)Mo/(99m)Tc generator on Bacillus subtilis and Bacillus pumilus species.

    PubMed

    Fukumori, Neuza T O; Endo, Erica M M; Felgueiras, Carlos F; Matsuda, Margareth M N; Osso Junior, João A

    2016-01-01

    In this work, molybdenum-99 loaded columns were challenged with Bacillus subtilis vegetative cells and Bacillus pumilus spores inside and outside the alumina column, and microbial recovery and radiation effect were assessed. Alumina was a barrier for the passage of microorganisms regardless the species, whilst spores were more retained than vegetative cells with a lower microbial recovery, without significant differences between 9.25 and 74GBq generators. Bacillus pumilus biological indicator showed lower recoveries, suggesting a radiation inactivating effect on microorganisms. PMID:26408912

  7. 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.

  8. Nanoparticulas basadas en complejos de Fe(II) con transicion de espin: sintesis, caracterizacion y aplicaciones en electronica molecular

    NASA Astrophysics Data System (ADS)

    Monrabal Capilla, Maria

    Esta tesis doctoral esta organizada en 5 capitulos y esta destinada al estudio de sistemas de Fe (II) que presentan el fenomeno de la transicion de espin a escala nanometrica. El capitulo 1 contiene una introduccion general sobre materiales moleculares multifuncionales, destacando aquellos ejemplos mas importantes. Por otro lado, se explicara el fenomeno de la transicion de espin, tratando aspectos conceptuales, los antecedentes mas importantes y la situacion actual. En el capitulo 2 se describen los diferentes procesos existentes para la obtencion de diferentes tipos de nanoparticulas. Ademas, se presenta la sintesis y caracterizacion de nanoparticulas del polimero de coordinacion unidimensional [Fe(Htrz)2(trz)]BF4, obtenidas mediante el metodo de micelas inversas. Estas nanoparticulas, con una estrecha distribucion de tamanos centrada alrededor de los 11 nm, presentan una transicion de espin muy abrupta, con un ancho ciclo de histeresis termica de unos 40K. En el capitulo 3 se describe el proceso de modificacion del tamano de las nanoparticulas descritas en el capitulo anterior, llevado a cabo variando la proporcion de surfactante/H2O en el medio. Ademas, con el objetivo de modificar las propiedades magneticas de las nanoparticulas obtenidas en el capitulo 2, se lleva a cabo la sintesis de nanoparticulas de polimeros de la misma familia del [Fe(Htrz)2(trz)]BF4. En concreto se sintetizaron 3 nuevos tipos de nanoparticulas basadas en el polimero [Fe(Htrz)1-x(NH2trz)x](ClO4)2, siendo x = 0.05, 0.15 y 0.3, en cada caso. Estas nanoparticulas siguen presentando una estrecha distribucion de tamanos y una transicion de espin muy abrupta y con un ancho ciclo de histeresis. Ademas, se observa que este ciclo se desplaza a temperaturas mas proximas a la temperatura ambiente a medida que se aumenta el porcentaje de 4-amino-1, 2, 4- triazol en la muestra. Pero al mismo tiempo se produce una disminucion de la anchura de este ciclo. Por ultimo, en este capitulo se presenta la sintesis de otro nuevo tipo de nanoparticulas, obtenidas a partir de otro polimero de la misma familia, el [FeO8ZnO2(Htrz)3](BF4). Estas nanoparticulas se sintetizaron con el objetivo de estudiar el efecto de la dilucion del metal en la muestra. Como resultado se obtuvieron nanoparticulas que tambien presentan una estrecha distribucion de tamanos pero en este caso la transicion de espin no es tan abrupta como en los casos anteriores. Aunque sigue presentando un ciclo de histeresis termica bastante ancho y a temperaturas proximas a la temperatura ambiente. En el capitulo 4 se describiran las estrategias que se han seguido para mejorar la estabilidad y afinidad sobre diferentes sustratos de las nanoparticulas sintetizadas en el capitulo 2. Tambien se hablara de los intentos realizados parar depositarlas en superficies y embeberlas en diferentes matrices organicas e inorganicas. En el capitulo 5 presentaremos la obtencion de un interruptor molecular realizado poniendo en contacto nanoparticulas individuales sintetizadas en el capitulo 2, con unos electrodos separados varios nanometros. Este dispositivo exhibe "switching" y efecto memoria a temperaturas proximas a la temperatura ambiente como consecuencia de la biestabilidad intrinseca de las nanoparticulas. Ademas demostraremos que el estado magnetico de estas nanoparticulas puede ser controlado electricamente, ya que la transicion de espin en este nanodispositivo molecular puede ser inducida simplemente aplicando un voltaje, lo que puede ser de gran interes para la electronica molecular.

  9. Superconducting bolometers: High- Tc and low- Tc

    SciTech Connect

    Richards, P.L.

    1991-04-01

    A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-{Tc} superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Then, there are reports on the design and experimental performance of two different types of high-{Tc} bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-{Tc} microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory. 14 refs.

  10. High- Tc bolometers

    SciTech Connect

    Richards, P.L.; Clarke, J.; Hu, Q.; Leoni, R.; Lerch, Ph.; Nahum, M.; Verghese, S. . Dept. of Physics Lawrence Berkeley Lab., CA ); Beasley, M.R.; Geballe, T.H.; Hammond, R.H.; Rosenthal, P.; Spielman, S.R. . Dept. of Applied Physics); Char, K.; Cole, B.F.; Newman, N.; Sachtjen, S.A. (Conductus, Inc., Sunnyvale, C

    1991-06-01

    A description is given of recent work on high-{Tc} superconducting bolometers for infrared and millimeter wavelengths. The first report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Then, there are reports on the design and experimental performance of two different types of high-{Tc} bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna-coupled microbolometer. Finally, there is a description of the ultimate performance expected from high-{Tc} bolometers on Si and Si{sub 3}N{sub 4} membrane substrates, with comparisons to other detectors used for thermal imaging. 7 refs.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. Half Life of 101Mo and 101Tc ?--decay

    NASA Astrophysics Data System (ADS)

    da Silva, Antonio Carlos O.; Genezini, Frederico A.; Zamboni, Cibele B.; Zahn, Guilherme S.; da Cruz, Manoel Tiago F.

    2009-06-01

    In this work, the half-lives of the beta-unstable nuclei 101Mo and 101Tc were studied using neutron-irradiated samples of 100Mo to produce 101Mo which in its turn generates 101Tc 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.

  16. Power Systems Development Facility Gasification Test Campaign TC25

    SciTech Connect

    Southern Company Services

    2008-12-01

    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 TC25, the second test campaign using a high moisture lignite coal from the Red Hills mine in Mississippi as the feedstock in the modified Transport Gasifier configuration. TC25 was conducted from July 4, 2008, through August 12, 2008. During TC25, the PSDF gasification process operated for 742 hours in air-blown gasification mode. Operation with the Mississippi lignite was significantly improved in TC25 compared to the previous test (TC22) with this fuel due to the addition of a fluid bed coal dryer. The new dryer was installed to dry coals with very high moisture contents for reliable coal feeding. The TC25 test campaign demonstrated steady operation with high carbon conversion and optimized performance of the coal handling and gasifier systems. Operation during TC25 provided the opportunity for further testing of instrumentation enhancements, hot gas filter materials, and advanced syngas cleanup technologies. The PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane with syngas from the Transport Gasifier.

  17. PREFACE: 13th IMEKO TC17-TC7 Joint Symposium

    NASA Astrophysics Data System (ADS)

    Khan, Sanowar

    2010-04-01

    'Without Measurement No Science, Without Science No Measurement' The 13th IMEKO (International Measurement Confederation) TC1-TC7 Joint Symposium was held at City University London, UK from 1-3 September 2010. For the first time this Symposium also included the involvement of IMEKO Technical Committee 13 (TC13) - Measurements in Biology and Medicine. This brings an added dimension to the Symposium in London since the area of measurement science and technology in biology and medicine is an important and a fast growing one. The Symposium was organized by the City University London (www.city.ac.uk) in collaboration with the Institute of Physics (IOP), UK (www.iop.org). The work of this Symposium is reported in this volume. The scope of the Symposium included the main topics covered by the above Technical Committees - education and training in measurement and instrumentation (TC1), measurement science (TC7) and measurements in biology and medicine. These themes underpinned the strap line of the Symposium, 'Without Measurement No Science, Without Science No Measurement' with the highest number of contributions from the measurement science area. The thematic areas were led by invited presentations from each of the areas by eminent speakers. The Symposium provided a useful forum for experts working in these areas for sharing and exchanging their work and ideas. The Symposium attracted participants from many countries of the world including the United States, Japan, Russia and Ukraine. In total over sixty papers are included in the volume and they are presented under the above three key thematic areas. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The organizers of the Symposium, City University London have pioneered the establishment of measurement and instrumentation as an academic discipline in the UK through the work of Professor Ludwik Finkelstein who was for many years Chairman of TC1 and a founding member of TC7. We would like to take this opportunity to thank the members of the Symposium Organizing Committee and the Instrument Science and Technology Group of the Institute of Physics for their support and encouragement. Our thanks also go to the members of the Symposium Steering and International Programme Committees many of whom acted as reviewers of the papers presented here under a very short timescale. Special thanks go to Claire Garland and Dawn Stewart of the Meetings and Conferences Department of the IOP and to the events team at City University London for their hard work in the organization of various activities associated with the Symposium. Finally, we would like to thank our sponsors, the Institute of Measurement and Control and the Worshipful Company of Scientific Instrument Makers for their active support. The co-editors Kenneth Grattan, Ludwik Finkelstein, Panicos Kyriacou, and I hope that this volume is a useful contribution to enhancing the science, technology, education, and training in measurement and instrumentation. Editors Sanowar Khan (Conference Chairman) Kenneth Grattan Ludwik Finkelstein Panicos Kyriacou City University London School of Engineering and Mathematical Sciences Northampton Square London EC1V 0HB UK

  18. Mo-99/Tc-99m Separation: An Assessment of Technical Options

    SciTech Connect

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

    2013-01-01

    Several strategies for the effective separation of 99mTc from 99Mo have been developed and validated. Due to the success of column chromatographic separation using acidic alumina coupled with high specific activity fission 99Mo (F 99Mo) for production of 99Mo/99mTc generators, however, most technologies until recently have generated little interest. The reduced availability of F 99Mo and consequently the shortage of 99Mo/99mTc column generators in the recent past have resurrected interest in the production of 99Mo as well as 99mTc by alternate routes. Most of these alternative production processes require separation techniques capable of providing clinical grade 99mTc from low specific activity 99Mo or irradiated Mo targets. For this reason there has been renewed interest in alternate separation routes. This paper reviews the reported separation technologies which include column chromatography, solvent extraction, sublimation and gel systems that have been traditionally used for the fabrication of 99Mo/99mTc generator systems. The comparative advantage, disadvantage, and technical challenges toward adapting the emerging requirements are discussed. New developments such as solid-phase column extraction, electrochemical separation, extraction chromatography, supported liquid membrane (SLM) and thermochromatographic techniques are also being evaluated for their potential application in the changed scenario of providing 99mTc from alternate routes. Based on the analysis provided in this review, it appears that some proven separation technologies can be quickly resurrected for the separation of clinical grade 99mTc from macroscopic levels of reactor or cyclotron irradiated molybdenum targets. Furthermore, emerging technologies can be developed further to respond to the expected changing modes of 99mTc production.

  19. Hopping in high {Tc} cuprates

    SciTech Connect

    Forro, L.

    1994-03-30

    High temperature superconductors based on copper oxide are fascinating materials not only because of their high transition temperatures which reach values as high as 130K, but also because of the possibility of studying other phenomena such as low dimensional magnetism, two dimensional localization, weak localization and hopping. Many oxide families are now known with different maximum {Tc} values. All these systems have CuO{sub 2} planes as conducting units. At low carrier density the system is electrically insulating with a long range antiferromagnetic order below a Neel temperature of the order of 300 K, which falls strongly with increased carrier concentration. Above a critical carrier density superconductivity appears, {Tc} reaches maximum at an optimal carrier density and decreases on further doping. For the superconducting compositions the system is generally metallic above {Tc} but there is a common opinion that it is an unusual metal with strong electron-electron correlations. Studies of hopping can be made in the low carrier density range, where the samples are non-metallic and one hopes to gain insight into the density of states, electron correlations, dimensionality of the charge transport etc. by resistivity measurements. It is less commonly known that there is also hopping-like transport even for higher carrier concentrations. Namely this is the case for the transverse charge transport between the CuO{sub 2} planes in the metallic phase.

  20. Simulation of the direct production of 99mTc at a small cyclotron

    NASA Astrophysics Data System (ADS)

    Eslami, M.; Kakavand, T.

    2014-06-01

    Usually 99mTc is produced indirectly through generator 99Mo/99mTc. In the present study, the direct production of this radioisotope by charged particle irradiation was investigated using Monte Carlo method. After scouting of the reactions that produce 99mTc, excitation functions of these reactions were predicted by optical model components in the TALYS-1.6 code. Suitable energy range of projectile for this production was selected by spotting of maximum cross section and minimum impurity due to other emission channels. Then target geometry was designed based on stopping power calculation by the SRIM code. Thick target yield of 100Mo(p,2n)99mTc, 98Mo(p,?)99mTc and natMo(p,x)99mTc reactions was predicted by the result of excitation function and stopping power calculations. Finally, 100Mo(p,2n)99mTc reaction was selected as a primary reaction for the direct production of 99mTc and its process was simulated by employing the MCNPX code to calculate the energy distribution of proton in the 100Mo target body and estimation of residual nuclei during irradiation. Good agreement was obtained between the experimental, the theoretical, and the simulation-based (analytical and directly) production yields. This study demonstrated that Monte Carlo provides a method for the design and optimization of targets for the radionuclide production purposes.

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

    PubMed

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

    2007-01-15

    Technetium, found in some nuclear wastes (such as those generated from spent fuel reprocessing), is of particular concern with regard to long-term waste storage because of its long half-life (2.13 x 10(5) years) and high mobility in the environment. One method of stabilization of such waste is through vitrification to produce a durable borosilicate glass matrix. The fate of Tc under hydrothermal conditions in the vapor hydration test (VHT) was studied to assess and possibly predict the long-term rate of release of Tc from borosilicate waste glass. For comparison, the fate of rhenium, the preferred nonradioactive surrogate for Tc, was similarly studied. X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on each original borosilicate glass and the corresponding sample after the VHT. Tc K-edge XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, both corresponding VHT samples contain 100% Tc(IV). The Tc reduction within the VHT samples may be driven by the low-oxygen atmosphere compounded by oxygen depletion from corrosion of the surrounding stainless steel vessel. From SEM analyses, both of the Tc-containing VHT samples show complete alteration of the original glass, significant Tc enrichment near the sample surface, and nearly complete depletion of Tc toward the sample center. XAS indicates Tc(IV)O6 octahedra, possibly within gel-like amorphous silicates in both VHT samples, where Tc-Tc correlations are observed in the higher Tc-content VHT sample. Re L(II)-edge XAS and SEM indicate quite different behavior for Re under VHT conditions. The Re oxidation state appears to be invariant with respect to the VHT treatment, where perrhenate (Re(VII)) species are dominant in all Re-containing samples investigated; Re2O7 concentrations are low near the sample surface and increase to approach that of the unreacted glass toward the sample center. PMID:17310703

  2. Interdecadal changes in summer TC activity in East China Sea

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    The study analyzed the time series of the tropical cyclone (TC) frequencies which passed through the East China Sea between July and September from 1963 to 2012. The result of applying the statistical change-point analysis to this time series shows that a climate regime shift occurred in 1983 when the TC frequencies which pass the East China Sea area started increasing. The study then analyzed the average difference after 1983 (1984-2012) and before 1983 (1963-1983). The TC genesis frequency shows a tendency in mainly appearing in the tropical and subtropical Northwestern Pacific between 1963 and 1983 and the southern part between 1984 and 2012. The TC passage frequency shows a pattern that the TCs move from the far northeast sea of Philippines and change direction to Korea and Japan, passing through the East China Sea between 1984 and 2012. Meanwhile, the TC passage frequency shows a pattern which moves from the far southeast sea of the Philippines to southern China in the west direction in the previous period (1963-1983). These TC movement patterns coincide with the development status of the subtropical western North Pacific high (SWNPH) which averages for each period. It shows that the SWNPH in the second period stays away from the SWNPH in the second period from the northeast direction, but that the SWNPH in the first period expands to western Taiwan. This study analyzes the difference between the two periods in the 500-hPa streamline to understand the changes in such TC activities in the two groups. The anomalous anticyclonic circulations centered in the southern part of Japan are fortified in most of the subtropical Northwestern Pacific. The anomalous southerlies from the anomalous circulations are outstanding in the East China Sea area, Korea, and Japan. Therefore, the TCs generated in the tropical and subtropical Northwestern Pacific move along with the anomalous steering flow (anomalous southwesterlies) and up toward the East China Sea area, Korea, and Japan. The anomalous anticyclonic circulations are fortified in most of the subtropical Northwestern Pacific areas, but the anomalous cyclonic circulations are strengthened in the tropical Northwestern Pacific below 15° N, causing the generation of TCs mainly in the northwestern part of the tropical and subtropical Northwestern Pacific between 1963 and 1983, and in the southeastern part between 1984 and 2012.

  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. Development of a Luminex Bead Based Assay for Diagnosis of Toxocariasis Using Recombinant Antigens Tc-CTL-1 and Tc-TES-26

    PubMed Central

    Anderson, John P.; Rascoe, Lisa N.; Levert, Keith; Chastain, Holly M.; Reed, Matthew S.; Rivera, Hilda N.; McAuliffe, Isabel; Zhan, Bin; Wiegand, Ryan E.; Hotez, Peter J.; Wilkins, Patricia P.; Pohl, Jan; Handali, Sukwan

    2015-01-01

    The clinical spectrum of human disease caused by the roundworms Toxocara canis and Toxocara cati ranges from visceral and ocular larva migrans to covert toxocariasis. The parasite is not typically recovered in affected tissues, so detection of parasite-specific antibodies is usually necessary for establishing a diagnosis. The most reliable immunodiagnostic methods use the Toxocara excretory-secretory antigens (TES-Ag) in ELISA formats to detect Toxocara-specific antibodies. To eliminate the need for native parasite materials, we identified and purified immunodiagnostic antigens using 2D gel electrophoresis followed by electrospray ionization mass spectrometry. Three predominant immunoreactive proteins were found in the TES; all three had been previously described in the literature: Tc-CTL-1, Tc-TES-26, and Tc-MUC-3. We generated Escherichia coli expressed recombinant proteins for evaluation in Luminex based immunoassays. We were unable to produce a functional assay with the Tc-MUC-3 recombinant protein. Tc-CTL-1 and Tc-TES-26 were successfully coupled and tested using defined serum batteries. The use of both proteins together generated better results than if the proteins were used individually. The sensitivity and specificity of the assay for detecting visceral larval migrans using Tc-CTL-1 plus Tc-TES-26 was 99% and 94%, respectively; the sensitivity for detecting ocular larval migrans was 64%. The combined performance of the new assay was superior to the currently available EIA and could potentially be employed to replace current assays that rely on native TES-Ag. PMID:26485145

  5. Development of a Luminex Bead Based Assay for Diagnosis of Toxocariasis Using Recombinant Antigens Tc-CTL-1 and Tc-TES-26.

    PubMed

    Anderson, John P; Rascoe, Lisa N; Levert, Keith; Chastain, Holly M; Reed, Matthew S; Rivera, Hilda N; McAuliffe, Isabel; Zhan, Bin; Wiegand, Ryan E; Hotez, Peter J; Wilkins, Patricia P; Pohl, Jan; Handali, Sukwan

    2015-10-01

    The clinical spectrum of human disease caused by the roundworms Toxocara canis and Toxocara cati ranges from visceral and ocular larva migrans to covert toxocariasis. The parasite is not typically recovered in affected tissues, so detection of parasite-specific antibodies is usually necessary for establishing a diagnosis. The most reliable immunodiagnostic methods use the Toxocara excretory-secretory antigens (TES-Ag) in ELISA formats to detect Toxocara-specific antibodies. To eliminate the need for native parasite materials, we identified and purified immunodiagnostic antigens using 2D gel electrophoresis followed by electrospray ionization mass spectrometry. Three predominant immunoreactive proteins were found in the TES; all three had been previously described in the literature: Tc-CTL-1, Tc-TES-26, and Tc-MUC-3. We generated Escherichia coli expressed recombinant proteins for evaluation in Luminex based immunoassays. We were unable to produce a functional assay with the Tc-MUC-3 recombinant protein. Tc-CTL-1 and Tc-TES-26 were successfully coupled and tested using defined serum batteries. The use of both proteins together generated better results than if the proteins were used individually. The sensitivity and specificity of the assay for detecting visceral larval migrans using Tc-CTL-1 plus Tc-TES-26 was 99% and 94%, respectively; the sensitivity for detecting ocular larval migrans was 64%. The combined performance of the new assay was superior to the currently available EIA and could potentially be employed to replace current assays that rely on native TES-Ag. PMID:26485145

  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. 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.

  9. Technetium-99m generator system

    DOEpatents

    Mirzadeh, Saed (Knoxville, TN); Knapp, Jr., Furn F. (Oak Ridge, TN); Collins, Emory D. (Knoxville, TN)

    1998-01-01

    A .sup.99 Mo/.sup.99m Tc generator system includes a sorbent column loaded with a composition containing .sup.99 Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating .sup.99m Tc eluted from the sorbent column. A method of preparing a concentrated solution of .sup.99m Tc includes the general steps of: a. providing a sorbent column loaded with a composition containing .sup.99 Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; b. eluting the sorbent column with a salt solution to elute .sup.99m Tc from the sorbent and to trap and concentrate the eluted .sup.99m Tc on the ion-exchange column; and c. eluting the concentrated .sup.99m Tc from the ion-exchange column with a solution comprising a reductive complexing agent.

  10. Technetium-99m generator system

    DOEpatents

    Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

    1998-06-30

    A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

  11. 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.

  12. Scintillating 99Tc Selective Ion Exchange Resins

    SciTech Connect

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  13. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced (99m)Tc.

    PubMed

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

    2015-11-01

    Cyclotron production of [Formula: see text]Tc through the (100)Mo(p,2n)[Formula: see text]Tc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. Like most radioisotope production methods, cyclotron production of [Formula: see text]Tc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced [Formula: see text]Tc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (?) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of [Formula: see text]Tc and the count-rate limitations of ? spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring ? emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify (99)Mo breakthrough in generator-produced [Formula: see text]Tc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to ? emission rates from impurities per MBq of [Formula: see text]Tc over a large range of clinically-relevant production conditions. We show that estimates of the ? emission rates from Tc impurities per MBq of [Formula: see text]Tc can be used to estimate increases in radiation dose (relative to pure [Formula: see text]Tc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of [Formula: see text]Tc, [Formula: see text]Tc, [Formula: see text]Tc, [Formula: see text]Tc, [Formula: see text]Tc, [Formula: see text]Tc, and [Formula: see text]Tc, in addition to a number of non-Tc impurities. PMID:26449791

  14. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced 99mTc

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    Cyclotron production of {{}99\\text{m}} Tc through the 100Mo(p,2n){{}99\\text{m}} Tc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. Like most radioisotope production methods, cyclotron production of {{}99\\text{m}} Tc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced {{}99\\text{m}} Tc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (?) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of {{}99\\text{m}} Tc and the count-rate limitations of ? spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring ? emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify 99Mo breakthrough in generator-produced {{}99\\text{m}} Tc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to ? emission rates from impurities per MBq of {{}99\\text{m}} Tc over a large range of clinically-relevant production conditions. We show that estimates of the ? emission rates from Tc impurities per MBq of {{}99\\text{m}} Tc can be used to estimate increases in radiation dose (relative to pure {{}99\\text{m}} Tc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of {{}93\\text{g}} Tc, {{}93\\text{m}} Tc, {{}94\\text{g}} Tc, {{}94\\text{m}} Tc, {{}95\\text{m}} Tc, {{}95\\text{g}} Tc, and {{}96\\text{g}} Tc, in addition to a number of non-Tc impurities.

  15. Reexamination of cross sections of the 100Mo(p,2n)99mTc reaction

    NASA Astrophysics Data System (ADS)

    Takács, S.; Hermanne, A.; Ditrói, F.; Tárkányi, F.; Aikawa, M.

    2015-03-01

    The nuclear medicine community has been expressing concerns world wide regarding shortages of 99mTc supply based on fission production of 99Mo from highly enriched uranium (HEU) to prepare 99Mo/99mTc generators. As an alternative to reactor produced 99Mo/99mTc generator technology, the direct production of 99mTc on accelerators is considered. There are a number of methods of using accelerators to produce 99mTc and/or 99Mo. Direct production of 99mTc on highly enriched 100Mo target using cyclotrons is interesting for energies up to 20 MeV, so as to minimize the impurities from additional open reaction channels. To estimate the quality of the accelerator produced 99mTc all the possible reaction routes should be mapped which could be potentially involved in this technology. However, a well defined excitation function for the 100Mo(p,2n)99mTc primary reaction is needed, in order to achieve acceptable good results in assessing the quality of the accelerator-produced 99mTc by theoretical calculations. Most of the available experimental cross section data series for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. A large difference more than a factor of two may, indeed, be observed between the lowest and the highest datasets values. The aim of this study was therefore to get a new evaluation for the 100Mo(p,2n)99mTc cross section, through three independent experiments, aiming at a more confident estimation about the amplitude of the excitation function.

  16. 99mTC-Methylene diphosphonate uptake at injury site correlates with osteoblast differentiation and mineralization during bone healing in mice

    PubMed Central

    Zhong, Zhendong A; Peck, Anderson; Li, Shihong; VanOss, Jeff; Snider, John; Droscha, Casey J; Chang, Tingtung A; Williams, Bart O

    2015-01-01

    99mTc-Methylene diphosphonate (99mTc-MDP) is widely used in clinical settings to detect bone abnormalities. However, the mechanism of 99mTc-MDP uptake in bone is not well elucidated. In this study, we utilized a mouse tibia injury model, single-photon emission computed tomography (gamma scintigraphy or SPECT), ex vivo micro-computed tomography, and histology to monitor 99mTc-MDP uptake in injury sites during skeletal healing. In an ex vivo culture system, calvarial cells were differentiated into osteoblasts with osteogenic medium, pulsed with 99mTc-MDP at different time points, and quantitated for 99mTc-MDP uptake with a gamma counter. We demonstrated that 99mTc-MDP uptake in the injury sites corresponded to osteoblast generation in those sites throughout the healing process. The 99mTc-MDP uptake within the injury sites peaked on day 7 post-injury, while the injury sites were occupied by mature osteoblasts also starting from day 7. 99mTc-MDP uptake started to decrease 14 days post-surgery, when we observed the highest level of bony tissue in the injury sites. We also found that 99mTc-MDP uptake was associated with osteoblast maturation and mineralization in vitro. This study provides direct and biological evidence for 99mTc-MDP uptake in osteoblasts during bone healing in vivo and in vitro. PMID:26273540

  17. Behavior of reduced 99/Tc and 99/Tc organic complexes on Hanford soil

    SciTech Connect

    Franz, J.A.; Martin, L.Y.; Wiggins, D.J.

    1982-02-01

    Both synthetically and naturally derived organic complexing agents in soil have been found in other studies to accelerate the rate of migration of specific radionuclides. In an effort to aid in the development of comprehensive plans for the disposal of low-level waste, the effect of organic complexing agents on the transport properties of /sup 99/Tc, a long-lived constituent of radioactive waste, was examined. The effect of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and sodium citrate on the mobility of reduced Tc species was examined from two aspects: first, by techniques of desorption from soil in which reduced, sorbed Tc was exposed to solutions of organic ligands; and second, by exposure of synthetic Tc-organic complexes to soils. Only a slight desorption of reduced Tc from Hanford soil by EDTA was found to occur in 10-day desorption tests. However, when synthetic EDTA and DTPA complexes of reduced Tc were exposed to soil under similar conditions, only a slight amount of Tc was sorbed by the soil. This comparison clearly shows that at least one type of test did not reach equilibrium in the 10-day time period allowed. Although the effects of these complexants at equilibrium cannot be quantified from these data, it is obvious that they can have large effects on the mobility of reduced Tc. Desorption tests of reduced Tc from Hanford soil by citrate solutions showed definite indications of desorption only at a relatively high (0.01 M) citrate concentrations. Results with synthetic Tc(IV) and Tc(V) citrate complexes indicate the Tc(V) citrate complex to be strongly sorbed, while the Tc(IV) citrate complex was sorbed only slightly.

  18. Power Systems Development Facility Gasification Test Campaing TC18

    SciTech Connect

    Southern Company Services

    2005-08-31

    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 TC18 of the PSDF gasification process. Test campaign TC18 began on June 23, 2005, and ended on August 22, 2005, with the gasifier train accumulating 1,342 hours of operation using Powder River Basin (PRB) subbituminous coal. Some of the testing conducted included commissioning of a new recycle syngas compressor for gasifier aeration, evaluation of PCD filter elements and failsafes, testing of gas cleanup technologies, and further evaluation of solids handling equipment. At the conclusion of TC18, the PSDF gasification process had been operated for more than 7,750 hours.

  19. New Phenomenon Observed in Thermal Release of 99mTc from Molten 100MoO3

    NASA Astrophysics Data System (ADS)

    Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji; Sato, Nozomi; Ohta, Akio; Shiina, Takayuki; Kawauchi, Yukimasa

    2015-02-01

    99mTc for medical use can be separated by thermochromatography from molten 99MoO3. The effect of moist oxygen gas on the 99mTc release from molten 99MoO3 was investigated using a 99Mo/99mTc generator. 99Mo was produced from the reaction of 100Mo(n,2n)99Mo. A new phenomenon was observed: the release rate and the separation and the recovery efficiencies of 99mTc were higher in the moist oxygen gas than in the dry oxygen gas. The present result is a significant development towards the stable production of high quality 99mTc from molten MoO3 with high separation efficiency. The result also provides us a new insight into the interaction between the moist oxygen gas and the molten MoO3.

  20. Power Systems Development Facility Gasification Test Campaign TC24

    SciTech Connect

    Southern Company Services

    2008-03-30

    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 Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC24, the first test campaign using a bituminous coal as the feedstock in the modified Transport Gasifier configuration. TC24 was conducted from February 16, 2008, through March 19, 2008. The PSDF gasification process operated for about 230 hours in air-blown gasification mode with about 225 tons of Utah bituminous coal feed. Operational challenges in gasifier operation were related to particle agglomeration, a large percentage of oversize coal particles, low overall gasifier solids collection efficiency, and refractory degradation in the gasifier solids collection unit. The carbon conversion and syngas heating values varied widely, with low values obtained during periods of low gasifier operating temperature. Despite the operating difficulties, several periods of steady state operation were achieved, which provided useful data for future testing. TC24 operation afforded the opportunity for testing of various types of technologies, including dry coal feeding with a developmental feeder, the Pressure Decoupled Advanced Coal (PDAC) feeder; evaluating a new hot gas filter element media configuration; and enhancing syngas cleanup with water-gas shift catalysts. During TC24, the PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane.

  1. Secrets of Soil Survival Revealed by the Genome Sequence of Arthrobacter aurescens TC1

    PubMed Central

    Daugherty, Sean C; DeBoy, Robert T; Emerson, Joanne B; Shvartzbeyn, Alla; Radune, Diana; Vamathevan, Jessica; Riggs, Florenta; Grinberg, Viktoria; Khouri, Hoda; Wackett, Lawrence P; Nelson, Karen E; Sadowsky, Michael J

    2006-01-01

    Arthrobacter sp. strains are among the most frequently isolated, indigenous, aerobic bacterial genera found in soils. Member of the genus are metabolically and ecologically diverse and have the ability to survive in environmentally harsh conditions for extended periods of time. The genome of Arthrobacter aurescens strain TC1, which was originally isolated from soil at an atrazine spill site, is composed of a single 4,597,686 basepair (bp) circular chromosome and two circular plasmids, pTC1 and pTC2, which are 408,237 bp and 300,725 bp, respectively. Over 66% of the 4,702 open reading frames (ORFs) present in the TC1 genome could be assigned a putative function, and 13.2% (623 genes) appear to be unique to this bacterium, suggesting niche specialization. The genome of TC1 is most similar to that of Tropheryma, Leifsonia, Streptomyces, and Corynebacterium glutamicum, and analyses suggest that A. aurescens TC1 has expanded its metabolic abilities by relying on the duplication of catabolic genes and by funneling metabolic intermediates generated by plasmid-borne genes to chromosomally encoded pathways. The data presented here suggest that Arthrobacter's environmental prevalence may be due to its ability to survive under stressful conditions induced by starvation, ionizing radiation, oxygen radicals, and toxic chemicals. PMID:17194220

  2. PREFACE: 2014 Joint IMEKO TC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security

    NASA Astrophysics Data System (ADS)

    Sousa, João A.; Ribeiro, Álvaro S.; Filipe, Eduarda

    2015-02-01

    The 2014 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium was organized by RELACRE - Portuguese Association of Accredited Laboratories and the Portuguese Society for Metrology, on 3-5 September 2014. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: - TC1 Education and Training in measurement and Instrumentation - TC7 Measurement Science - TC13 Measurements in Biology and Medicine The effort towards excellence of previous events, in this well established series, is maintained. There has been a special focus on measurement science behind safety and security, with the aim of highlighting the interdisciplinary character of measurement science and the importance of metrology in our daily lives. The discussion was introduced by keynote lectures on measurement challenges in biometrics, health monitoring and social sciences, to promote useful interactions with scientists from different disciplines. The Symposium was attended by experts working in these areas from 18 countries, including USA, Japan and China, and provided a useful forum for them to share and exchange their work and ideas. In total over fifty papers are included in the volume, organized according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Funchal, capital of Madeira Islands, known as the Atlantic Pearl. This wonderful Atlantic archipelago, formed by Madeira and Porto Santo islands, discovered in the 14th century, was chosen to host the 2014 IMEKO TC1-TC7-TC13 Joint Symposium ''Measurement Science behind Safety and Security''. It was the first territory discovered by the Portuguese sailors, when set out to discover a new world, in an epic journey where instrumentation and quality of measurement played a central role in the success of the enterprise, and gave an important technological edge to those men. A fortunate analogy to the advances sought by the research undertaken in the areas covered by this event. We would like to take this opportunity to thank the members of the Symposium Steering and International Programme Committees, many of whom acted as reviewers of the papers presented here under a very short timescale, as well as our partner, SPMet - Portuguese Society for Metrology. The editors hope that this volume will provide a useful contribution to enhancing the science, technology, education, and training in measurement and instrumentation. João A. Sousa, Álvaro S. Ribeiro and Eduarda Filipe Editors

  3. High-frequency excision of transposable element Tc 1 in the nematode Caenorhabditis elegans is limited to somatic cells.

    PubMed

    Emmons, S W; Yesner, L

    1984-03-01

    Tc 1 transposable elements in the nematode Caenorhabditis elegans undergo excision at high frequency. We show here that this excision occurs primarily or entirely in the somatic tissues of the organism. Absence of germ-line excision is demonstrated by showing that Tc 1 elements are genetically stable; elements at particular genomic sites, as well as the overall number of elements in the genome, were stably maintained during a year of continuous, nonselective propagation. Somatic excision is demonstrated by showing that empty Tc 1 sites arise during a single generation of growth of a synchronous population and are not inherited by the next generation. These results suggest that excision of Tc 1 elements is under the control of tissue-specific factors. PMID:6321037

  4. 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.

  5. Uptake, biotransformation, and elimination of 99Tc in duckweed.

    PubMed

    Hattink, Jasper; Harms, Arend V; de Goeij, Jeroen J M

    2003-08-01

    Aquatic plants may play an important role in the environmental fate of the long-lived radioactive waste product 99Tc. Aquatic plants show a strong accumulation and retention of Tc, even after they have died. This study focuses on possible bio-organic Tc compounds formed in the water dwelling plant duckweed to possibly explain the accumulation and retention. Moreover, a change in chemical speciation often implies a different fate and behaviour in the biosphere. A mild separation technique was used to distinguish between reduced Tc species and TcO(4)(-). Accumulation experiments suggested that reduction of Tc(VII)O(4)(-) and subsequent complexation are responsible for the accumulation of Tc in duckweed. A steady state concentration of TcO(4)(-) in duckweed was reached within 24 h, but the total concentration of Tc increased continuously. Only a small part (Tc was present as TcO(4)(-). Elimination experiments showed that TcO(4)(-) is the only mobile species. Other Tc species are responsible for the retention of Tc in duckweed. It is known that these species are not bio-available and only slowly re-oxidise to pertechnetate, resulting in a longer residence time in ecosystems. PMID:12873399

  6. Density-functional computation of (99)Tc NMR chemical shifts.

    PubMed

    Bühl, Michael; Golubnychiy, Volodymyr

    2008-01-01

    99Tc chemical shifts of TcO4(-), TcH9(2-), TcOF5, TcO2F4(-), TcOCl4(-), Tc2(CO)10, and Tc(CO)3L3(+) (L = CO, MeCN, H2O) are computed using geometries optimized with the gradient-corrected BP86 and hybrid B3P86 density functionals, at the gauge-including atomic orbitals (GIAO), -BPW91 and -B3LYP levels. For this set of compounds, substituent effects on delta(99Tc) are better described with the pure BPW91 functional than with B3LYP, in contrast to most other transition-metal chemical shifts studied so far. A rough, qualitative correlation is found between computed electric-field gradients at the Tc nuclei and the corresponding 99Tc NMR line widths. Thermal and solvation effects on magnetic shielding constants of aqueous TcO4(-), as assessed by averaging these properties over trajectories from Car-Parrinello molecular dynamics simulations, are indicated to be small and comparable to those of MnO4(-). Complexation to aqueous uranyl, UO2(2+), is predicted to affect delta(99Tc) of TcO4(-) only slightly; somewhat larger complexation shifts are obtained for the oxygen nuclei of pertechnetate, suggesting that 17O NMR could be a useful probe for the extent of association between both radionuclides in solution. PMID:18855338

  7. CTLA-4 (CD152) enhances the Tc17 differentiation program.

    PubMed

    Pick, Jonas; Arra, Aditya; Lingel, Holger; Hegel, J Kolja; Huber, Magdalena; Nishanth, Gopala; Jorch, Gerhard; Fischer, Klaus-Dieter; Schlüter, Dirk; Tedford, Kerry; Brunner-Weinzierl, Monika C

    2014-07-01

    Although CD8(+) T cells that produce IL-17 (Tc17 cells) have been linked to host defense, Tc17 cells show reduced cytotoxic activity, which is the characteristic function of CD8(+) T cells. Here, we show that CTLA-4 enhances the frequency of IL-17 in CD8(+) T cells, indicating that CTLA-4 (CD152) specifically promotes Tc17 differentiation. Simultaneous stimulation of CTLA-4(+/+) and CTLA-4(-/-) T cells in cocultures and agonistic CTLA-4 stimulation unambiguously revealed a cell-intrinsic mechanism for IL-17 control by CTLA-4. The quality of CTLA-4-induced Tc17 cells was tested in vivo, utilizing infection with the facultative intracellular bacterium Listeria monocytogenes (LM). Unlike CTLA-4(+/+) Tc17 cells, CTLA-4(-/-) were nearly as efficient as Tc1 CTLA-4(+/+) cells in LM clearance. Additionally, adoptively transferred CTLA-4(-/-) Tc17 cells expressed granzyme B after rechallenge, and produced Tc1 cytokines such as IFN-? and TNF-?, which strongly correlate with bacterial clearance. CTLA-4(+/+) Tc17 cells demonstrated a high-quality Tc17 differentiation program ex vivo, which was also evident in isolated IL-17-secreting Tc17 cells, with CTLA-4-mediated enhanced upregulation of Tc17-related molecules such as IL-17A, ROR?t, and IRF-4. Our results show that CTLA-4 promotes Tc17 differentiation that results in robust Tc17 responses. Its inactivation might therefore represent a central therapeutic target to enhance clearance of infection. PMID:24723371

  8. A comparison of rat SPECT images obtained using 99mTc derived from 99Mo produced by an electron accelerator with that from a reactor

    NASA Astrophysics Data System (ADS)

    Galea, R.; Wells, R. G.; Ross, C. K.; Lockwood, J.; Moore, K.; Harvey, J. T.; Isensee, G. H.

    2013-05-01

    Recent shortages of molybdenum-99 (99Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce 99Mo from which technetium-99m (99mTc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced 99mTc with those obtained using 99mTc from a commercial generator were compared. Disks of 100Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of 99Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the 99mTc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using 99mTc from a standard reactor 99Mo generator. The efficiency of 99Mo-99mTc separation was typically greater than 90%. This study demonstrated the delivery of 99mTc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced 99mTc were comparable. High-power electron accelerators are an attractive option for producing 99Mo on a national scale.

  9. A comparison of rat SPECT images obtained using (99m)Tc derived from 99Mo produced by an electron accelerator with that from a reactor.

    PubMed

    Galea, R; Wells, R G; Ross, C K; Lockwood, J; Moore, K; Harvey, J T; Isensee, G H

    2013-05-01

    Recent shortages of molybdenum-99 ((99)Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce (99)Mo from which technetium-99m ((99m)Tc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced (99m)Tc with those obtained using (99m)Tc from a commercial generator were compared. Disks of (100)Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of (99)Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the (99m)Tc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using (99m)Tc from a standard reactor (99)Mo generator. The efficiency of (99)Mo-(99m)Tc separation was typically greater than 90%. This study demonstrated the delivery of (99m)Tc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced (99m)Tc were comparable. High-power electron accelerators are an attractive option for producing (99)Mo on a national scale. PMID:23552053

  10. 99mTc: Labeling Chemistry and Labeled Compounds

    NASA Astrophysics Data System (ADS)

    Alberto, R.; Abram, U.

    This chapter reviews the radiopharmaceutical chemistry of technetium related to the synthesis of perfusion agents and to the labeling of receptor-binding biomolecules. To understand the limitations of technetium chemistry imposed by future application of the complexes in nuclear medicine, an introductory section analyzes the compulsory requirements to be considered when facing the incentive of introducing a novel radiopharmaceutical into the market. Requirements from chemistry, routine application, and market are discussed. In a subsequent section, commercially available 99mTc-based radiopharmaceuticals are treated. It covers the complexes in use for imaging the most important target organs such as heart, brain, or kidney. The commercially available radiopharmaceuticals fulfill the requirements outlined earlier and are discussed with this background. In a following section, the properties and perspectives of the different generations of radiopharmaceuticals are described in a general way, covering characteristics for perfusion agents and for receptor-specific molecules. Technetium chemistry for the synthesis of perfusion agents and the different labeling approaches for target-specific biomolecules are summarized. The review comprises a general introduction to the common approaches currently in use, employing the N x S4-x , [3+1] and 2-hydrazino-nicotinicacid (HYNIC) method as well as more recent strategies such as the carbonyl and the TcN approach. Direct labeling without the need of a bifunctional chelator is briefly reviewed as well. More particularly, recent developments in the labeling of concrete targeting molecules, the second generation of radiopharmaceuticals, is then discussed and prominent examples with antibodies/peptides, neuroreceptor targeting small molecules, myocardial imaging agents, vitamins, thymidine, and complexes relevant to multidrug resistance are given. In addition, a new approach toward peptide drug development is described. The section has a focus on coordination and labeling chemistry, but biological results are briefly summarized as well. The last (and shortest) section finally intends to give a (subjective) outlook for the future role of 99mTc-based radiopharmaceuticals. Critical comments are spread over the whole article but are concentrated in this section. Despite the increasing competition of diagnostic radiopharmacy by other commonly applied methods in medicine such as magnetic resonance imaging (MRI) or ultrasound, the authors are convinced that 99mTc will play a key role also in future if novel approaches are added and the requirements from chemistry biology and the market considered in research to a stronger extent.

  11. New technique for measuring the microwave penetration depth in high- Tc superconducting thin films

    NASA Astrophysics Data System (ADS)

    Durusoy, H. Z.; Akta?, B.; Yilgin, R.; Terada, N.; Ichikawa, M.; Kaneda, T.; Tagirov, L. R.

    2000-07-01

    The ferromagnetic resonance (FMR) technique has been used to obtain the microwave (MW) penetration depth in high-temperature superconductor (HTSC) thin film. An FMR-signal-generating thin permalloy film was sandwiched in between of two YBa 2Cu 3O 7 films to probe the MW field penetrating through the films. Below the superconducting transition temperature Tc the HTSC films started to screen the marker inside the sandwich. The low-temperature saturation value ? ab?1250 Å at 25 K has been deduced for our c-axis films from the temperature dependence of the FMR signal intensity below Tc.

  12. 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.

  13. Women, Family Systems & the TC. Chapter 8.

    ERIC Educational Resources Information Center

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

    This document contains 11 papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with women's issues, family systems, and the TC. Papers include: (1) "Families in the Eighties" (Cecil Williams); (2) "Women, Work & Substance Abuse" (Lois Morris); (3) "The National Federation of Parents" (Shirley Colletti); (4) "The…

  14. Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Potential application in liver transplantation

    SciTech Connect

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

    1984-01-01

    Tc-NGA is a hepatocyte receptor-specific imaging agent whose uptake by the liver has been shown to be dependent upon blood flow and receptor concentration. The combination of anatomic and physiologic information obtained with Tc-NGA may provide a new tool for studying hepatic function in liver transplant recipients. To evaluate the potential role of Tc-NGA in liver transplant recipients, studies were performed in four groups of pigs: controls (n=18); common bile duct (CBD) ligation (n=8); orthotopic liver transplant (n=9); and acute hepatic artery ligation (n=1). Serial studies performed in two animals with CBD ligation demonstrated normal imaging anatomy with minor changes in the hepatic time-activity curves when compared to control studies. Studies in liver-transplanted animals showed significant changes in the hepatic time-activity curves during acute rejection and in preservation-related ischemic injury. Tc-NGA also demonstrated focal areas of hepatic infarction in a hepatic allograft within 24 hours of transplantation. The hepatic artery ligation study showed massive changes in the hepatic time-activity curve within two hours after ligation, with a diffuse decrease in hepatic activity. These results indicate that: (1) extrahepatic biliary tract obstruction causes only minor changes in Tc-NGA uptake; (2) Tc-NGA uptake by the liver is very sensitive to acute hepatic ischemia; (3) Tc-NGA may indicate the presence of preservation damage in the early postoperative period; and (4) Tc-NGA hepatic time-activity curves demonstrate significant changes during acute rejection.

  15. 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.

  16. Power Systems Development Facility Gasification Test Campaign TC16

    SciTech Connect

    Southern Company Services

    2004-08-24

    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 discusses Test Campaign TC16 of the PSDF gasification process. TC16 began on July 14, 2004, lasting until August 24, 2004, for a total of 835 hours of gasification operation. The test campaign consisted of operation using Powder River Basin (PRB) subbituminous coal and high sodium lignite from the North Dakota Freedom mine. The highest gasifier operating temperature mostly varied from 1,760 to 1,850 F with PRB and 1,500 to 1,600 F with lignite. Typically, during PRB operations, the gasifier exit pressure was maintained between 215 and 225 psig using air as the gasification oxidant and between 145 and 190 psig while using oxygen as the oxidant. With lignite, the gasifier operated only in air-blown mode, and the gasifier outlet pressure ranged from 150 to 160 psig.

  17. TC Research: State of the Art. Chapter 3.

    ERIC Educational Resources Information Center

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

    This document contains six papers from the ninth World Conference of Therapeutic Communities that highlight research on therapeutic communities (TC) and discuss how to apply research findings in practical ways. Papers include: (1) "TC Research: Overview & Implications" (George De Leon); (2) "Emerging Cross-Cultural TC Research" (D. Vincent Biase…

  18. Vertical distributions of (99)Tc and the (99)Tc/(137)Cs activity ratio in the coastal water off Aomori, Japan.

    PubMed

    Nakanishi, Takahiro; Zheng, Jian; Aono, Tatsuo; Yamada, Masatoshi; Kusakabe, Masashi

    2011-08-01

    Using a sector-field ICP-MS the vertical distributions of the (99)Tc concentration and (99)Tc/(137)Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The (99)Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m(3), no greater than the estimated background level. Relatively high (99)Tc/(137)Cs activity ratios (10-12 × 10(-4)) would be caused by the inflow of the high-(99)Tc/(137)Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The (99)Tc concentration and the (99)Tc/(137)Cs activity ratio in water column showed gradual decreases with depth. Our results implied that (99)Tc behaves in a more conservative manner than (137)Cs in marine environments. PMID:21555170

  19. Reactivity of Tc at the Groundwater-Surface Water Interface

    NASA Astrophysics Data System (ADS)

    Zachara, J. M.; Fredrickson, J.; McKinley, J.

    2014-12-01

    Technetium-99 (t1/2 =211,000y) is environmentally mobile as the pertechnetate oxyanion [99Tc(VII)O4-(aq)]. Tc(VII) may react to less soluble Tc(IV) at intermediate redox potentials (Eo = -0.36 V) through heterogeneous reduction with solid-phase biogenic reaction products. 99Tc is forecast to migrate through groundwater to the Columbia River at the U.S. DOE Hanford site in Washington State. Discharge to surface water will occur through a groundwater-surface water interaction zone with complex hydrogeology and biogeochemistry that is stimulated by the overlapping nutrient regimes of groundwater and surface water. The reactivity of pertechnetate in reduced sediments from this zone was investigated to determine effects of biogenic ferrous-Fe and sulfide-S on Tc(VII) reduction rate; and the resulting speciation, mineral association, and physical location of Tc(IV). 99Tc(VII) was reduced to near detection (<10-9 Mol/L) over periods of days to months. Tc(VII) reduction rate was first order in [Tc(VII)]aq and sediment mass, but correlations with specific biogenic reductant concentrations [(Fe(II), ferrous mono-sulfide] were not found. Tc(IV) was isolated to fine-grained aggregates (0.1 to 0.5 mm) of "mud", consisting of primary mineral material embedded within a phyllosilicate or clay matrix. EXAFS revealed that product Tc(IV) existed as combinations of a Tc(IV)O2-like phase ,Tc(IV)-Fe surface clusters, and/or TcSx. Ferrous mono-sulfide was implicated as a more selective reductant. Migration of Tc(VII) through the interaction zone will be controlled by water residence time and the density and spatial distribution of fine-grained aggregates that host reductive biogeochemical processes in otherwise coarse-textured, partially oxygenated sediments.

  20. PREFACE: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences

    NASA Astrophysics Data System (ADS)

    Battista Rossi, Giovanni; Crenna, Francesco; Belotti, Vittorio

    2013-09-01

    The 2013 Joint IMEKO (International Measurement Confederation) TC1-C7-TC13 was organised by the University of Genova - DIME/MEC, Measurement Laboratory, Italy, on 4-6 September 2013. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: TC1 Education and Training in Measurement and Instrumentation TC7 Measurement Science TC13 Measurements in Biology and Medicine This is in keeping with the tradition set by the previous events of this well established series. There has been a special focus on measurement across physical and behavioural sciences, with the aim of highlighting the interdisciplinary character of measurement science and of promoting constructive interactions with scientists in other disciplines. The discussion was introduced by keynote lectures on measurement challenges in psychophysics, psychometrics and quantum physics. The symposium was attended by experts working in these areas from 18 countries, including USA, Australia and Japan, and provided a useful forum for them to share and exchange their work and ideas. In total over sixty papers are included in the volume, organised according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Genova, which was the European Capital of Culture in 2004, and took place in Palazzo Ducale, an important historical building whose construction started in the 13th century, and that has been the house of the Duke of Genova from the 14th century. Genova, whose name comes from the Latin word 'Janua' (meaning 'door', as January is the door month of the year), has been regarded over the centuries as a door connecting Europe with the different countries and cultures of the Mediterranean basin and thus was an appropriate site for an international symposium involving different and new scientific visions and approaches to measurement, focused on a common objective: the human being. We would like to take this opportunity to thank the members of the Symposium Steering and International Programme Committees, many of whom acted as reviewers of the papers presented here under a very short timescale, as well as our sponsor, National Instruments. The editors hope that this volume will provide a useful contribution to enhancing the science, technology, education, and training in measurement and instrumentation. Giovanni Battista Rossi, Francesco Crenna and Vittorio Belotti Editors Università degli Studi di Genova - DIME/MEC Laboratorio di Misure Via all'Opera Pia 15 a I - 16145 Genova Italy LogoLogoLogo

  1. 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.

  2. Shock compaction of high- Tc superconductors

    SciTech Connect

    Weir, S.T.; Nellis, W.J.; McCandless, P.C.; Brocious, W.F. ); Seaman, C.L.; Early, E.A.; Maple, M.B. . Dept. of Physics); Kramer, M.J. ); Syono, Y.; Kikuchi, M. )

    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.

  3. 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.

  4. 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.

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

    SciTech Connect

    Aloy, Albert; Kovarskaya, Elena N.; Harbour, John R.; Langton, Christine A.; Holtzscheiter, E. William

    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)

  6. 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.

  7. Method for the production of {sup 99m}Tc compositions from {sup 99}Mo-containing materials

    DOEpatents

    Bennett, R.G.; Christian, J.D.; Grover, S.B.; Petti, D.A.; Terry, W.K.; Yoon, W.Y.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions from {sup 99}Mo compounds. {sup 100}Mo metal or {sup 100}MoO{sub 3} is irradiated with photons in a particle (electron) accelerator to ultimately produce {sup 99}MoO{sub 3}. This composition is then heated in a reaction chamber to form a pool of molten {sup 99}MoO{sub 3} with an optimum depth of 0.5--5 mm. A gaseous mixture thereafter evolves from the molten {sup 99}MoO{sub 3} which contains vaporized {sup 99}MoO{sub 3}, vaporized {sup 99m}TcO{sub 3}, and vaporized {sup 99m}TcO{sub 2}. This mixture is then combined with an oxidizing gas (O{sub 2(g)}) to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7} and vaporized {sup 99}MoO{sub 3}. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized {sup 99}MoO{sub 3}. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing reaction product which is collected. 1 fig.

  8. Method for the production of .sup.99m Tc compositions from .sup.99 Mo-containing materials

    DOEpatents

    Bennett, Ralph G. (Idaho Falls, ID); Christian, Jerry D. (Idaho Falls, ID); Grover, S. Blaine (Idaho Falls, ID); Petti, David A. (Idaho Falls, ID); Terry, William K. (Idaho Falls, ID); Yoon, Woo Y. (Idaho Falls, ID)

    1998-01-01

    An improved method for producing .sup.99m Tc compositions from .sup.99 Mo compounds. .sup.100 Mo metal or .sup.100 MoO.sub.3 is irradiated with photons in a particle (electron) accelerator to ultimately produce .sup.99 MoO.sub.3. This composition is then heated in a reaction chamber to form a pool of molten .sup.99 MoO.sub.3 with an optimum depth of 0.5-5 mm. A gaseous mixture thereafter evolves from the molten .sup.99 MoO.sub.3 which contains vaporized .sup.99 MoO.sub.3, vaporized .sup.99m TcO.sub.3, and vaporized .sup.99m TcO.sub.2. This mixture is then combined with an oxidizing gas (O.sub.2(g)) to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7 and vaporized .sup.99 MoO.sub.3. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized .sup.99 MoO.sub.3. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing reaction product which is collected.

  9. Interdecadal variation of TC frequency in Japan

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    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.

  10. Physicochemical studies of the reaction of 99mTc with 5,5?-diethyl barbituric acid, adenine, D-glucose and thiobarbituric acid at different temperatures

    NASA Astrophysics Data System (ADS)

    Masoud, M. S.; El-Shahat, M. F.; Elkholany, A. S.

    2014-06-01

    The reaction of 99mTc pertechnetate with 5,5?-diethyl barbituric acid, adenine, D-glucose and thiobarbituric acid at different temperatures was studied. The solvent effect on the electronic absorption spectra of the reactions was recorded. The reaction mixtures have been analyzed at different times using TLC and a radiodetctor to show the peaks at the plates. 99mTc pertechnetate is obtained from the Mo generators. It is difficult to separate the complexes in the solid state. The percentage of 99mTc involved in the complexes can be determined. Characterization of the 99mTc complexes as well as the determination of the extent of radiolabeling was done by thin layer chromatography using 0.9% NaCl solution as a solvent. The Rf value of 99TcO4- is (?1). The solvatochromism for the reaction of 99mTc with D-glucose was mainly affected by solute permanent dipole-solvent permanent dipole interaction, the dipolar interaction for the reaction of 99mTc with of 5,5?-diethyl barbituric acid and for the reaction of 99mTc with adenine and thiobarbituric was solute-solvent hydrogen bonding.

  11. Retention of 99mTc-DMSA(III) and 99mTc-nanocolloid in different syringes affects imaging quality.

    PubMed

    Bauwens, Matthias; Pooters, Ivo; van der Pol, Jochen; Mottaghy, Felix M; van Kroonenburgh, Marinus

    2014-04-01

    (99m)Tc-dimercaptosuccinic acid [DMSA(III)] and colloidal human serum albumin ((99m)Tc-nanocolloid) are widely used radiopharmaceuticals. Recently, in our institution we encountered image quality problems in DMSA scans after changing the brand of syringes we were using, which triggered us to look into the adsorption properties of syringes from different brands for (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid. We also describe a clinical case in which adsorption of (99m)Tc-DMSA(III) caused inferior imaging quality. DMSA and nanocolloid were labeled with (99m)Tc following manufacturer guidelines. After synthesis, syringes with (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid were stored for 15, 30, 60, and 120 min. We evaluated Luer Lock syringes manufactured by different brands such as Artsana, Henke-Sass-Wolf, B. Braun Medical N.V., CODAN Medizinische Geräte GmbH & Co KG, Becton Dickinson and Company, and Terumo Europe. Adsorption of (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid was acceptably low for all syringes (<13%), except for two brands with (99m)Tc-DMSA(III) adsorption rates of 36 and 30%, respectively, and for one brand with a (99m)Tc-nanocolloid adsorption rate of 27%. Adsorption of (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid reaches critical levels in syringes produced by two brands, potentially causing poor image quality--for example, in DMSA scans using pediatric radiopharmaceutical doses. It is advised to check the compatibility of any radiopharmaceutical with syringes as an integral part of the quality assurance program. PMID:24569706

  12. Preparation, characterization and biological evaluation of cationic 99Tc/99mTc-dioxime complexes.

    PubMed

    Schwochau, K; Linse, K H; Steinmetz, H J; Astheimer, L

    1993-04-01

    New cationic 99Tc/99Tc complexes formed with various symmetrical and asymmetrical vicinal dioximes of different carbon chain length (C5-C8) were synthesized by reduction of pertechnetate with BH4-, separated by HPLC and characterized by i.r./u.v./vis. spectroscopy, FAB mass spectrometry and electrophoresis. All complexes studied are trisdioximes containing boron as a constituent. Their lipophilicity, as assessed by the octanol/saline partition coefficient, ranges over almost four orders of magnitude. The myocardial uptake of the 99mTc complexes in mice proves to be lower than expected. The organ distributions are distinctly affected by the lipophilicity, the position of the dioxime group and the introduction of a terminal methoxy group. PMID:8485491

  13. Light composite scalar boson from a see-saw mechanism in two-scale TC models

    NASA Astrophysics Data System (ADS)

    Doff, A.; Natale, A. A.

    2015-09-01

    We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can be generated when the TC theory features two technifermions species in different representations, R1 and R2, under a single technicolor gauge group, with characteristic scales ?1 and ?2. We determine the final composite scalar fields, ?1 and ?2, effective theory using the effective potential for composite operators approach. To generate a light composite scalar it is enough to have a walking (or quasi-conformal) behavior just for one of the technifermions representations.

  14. Light composite scalar boson from a see-saw mechanism in two-scale TC models

    E-print Network

    A. Doff; A. A. Natale

    2015-06-25

    We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can be generated when the TC theory features two technifermions species in different representations, $R_1$ and $R_2$, under a single technicolor gauge group, with characteristic scales $\\Lambda_1$ and $\\Lambda_2$. We determine the final composite scalar fields, $\\Phi_1$ and $\\Phi_2$, effective theory using the effective potential for composite operators approach. To generate a light composite scalar it is enough to have a walking (or quasi-conformal) behavior just for one of the technifermions representations.

  15. Light composite scalar boson from a see-saw mechanism in two-scale TC models

    E-print Network

    Doff, A

    2015-01-01

    We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can be generated when the TC theory features two technifermions species in different representations, $R_1$ and $R_2$, under a single technicolor gauge group, with characteristic scales $\\Lambda_1$ and $\\Lambda_2$. We determine the final composite scalar fields, $\\Phi_1$ and $\\Phi_2$, effective theory using the effective potential for composite operators approach. To generate a light composite scalar it is enough to have a walking (or quasi-conformal) behavior just for one of the technifermions representations.

  16. 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

  17. 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.

  18. TcDJ1, a putative mitochondrial DnaJ protein in Trypanosoma cruzi.

    PubMed

    Carreira, M A; Tibbetts, R S; Olson, C L; Schuster, C; Renz, M; Engman, D M; Goldenberg, S

    1998-09-01

    A full length cDNA encoding a novel Trypanosoma cruzi DnaJ protein was cloned and characterized. The 324 amino acid protein encoded by the cDNA (TcDJ1) displays a characteristics J-domain, but lacks the Gly-Phe and zinc finger regions present in some other DnaJ proteins. Relative to four other T. cruzi DnaJ proteins, TcDJ1 has an amino terminal extension containing basic and hydroxylated resides characteristic of mitochondrial import peptides. A T. cruzi transfectant expressing epitope-tagged TcDJ1 was generated and subcellular fractions were produced. Western blot analysis revealed that the protein has a molecular mass of 29 kDa and is found in the mitochondrial fraction. The expression of TcDJ1 is developmentally regulated since the levels of both mRNA and protein are much higher in epimastigotes (replicative form) than in metacyclic trypomastigotes (infective form). Thus it may participate in mitochondrial biosynthetic processes in this organism. PMID:9741092

  19. A numerical study of orographic forcing on TC Dina (2002) in South West Indian Ocean

    NASA Astrophysics Data System (ADS)

    Jolivet, S.; Chane-Ming, F.; Barbary, D.; Roux, F.

    2013-01-01

    Using the French non-hydrostatic mesoscale numerical model Méso-NH, intense tropical cyclone (TC) Dina (2002) is simulated to investigate the forcing caused by the steep orography of Réunion island (20.8° S, 55.5° E) in the southwest Indian Ocean. The model initialised by a bogus vortex derived from Doppler radar observations reproduces quite well the dynamical characteristics of TC Dina approaching the island and provides some clues on the orographic influence on the structure and the evolution of the TC. The presence of the island is observed to stabilise the cyclonic circulation by damping the natural elliptical eyewall rotation and forcing the flow circulation. Initially, the cyclonic flow is blocked upwind of the orography which induces a convergence associated with upward vertical velocities, intense precipitation and maximum horizontal winds along the upwind slopes of the island. A mountain wave, generated over the highest terrains, is associated with downward motions on the lee side. When the strongest winds reach the island, the flow changes its behaviour from passing around to over the island. Non-dimensional flow parameters in agreement with recent theories are calculated to explain TC track.

  20. Accumulation of 99Tc in duckweed Lemna minor L. as a function of growth rate and 99Tc concentration.

    PubMed

    Hattink, J; Wolterbeek, H T

    2001-01-01

    This study focuses on the question of whether short-term studies can be used to forecast the accumulation of the long-lived fission product 99Tc in duckweed, Lemna minor L., grown in the field; in other words, are the accumulation parameters independent of changing growth rates typical of natural populations of duckweed. Two processes determine the 99Tc accumulation: (i) uptake and release of 99TcO4-, characterised by a concentration factor, Kd, and (ii) first-order reduction and complexation of TcVII, characterised by kred. At various 99Tc concentrations, the growth, total Tc and TcO4- accumulation were monitored over 10 days; parameters were fitted and compared with earlier results. Both Kd and kred turn out to be independent of time, concentration and growth rate up to a concentration of 10(-6)mol l(-1) 99TcO4-. Concentrations above this level result in toxic effects. The Tc accumulation in field populations of duckweed at Tc concentrations which generally occur in the environment can be forecasted by using the results from short-term experiments. PMID:11545380

  1. 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.

  2. Radioactive equilibrium: 99Mo/99mTc decay characteristics.

    PubMed

    Chechev, Valery P; Bé, Marie-Martine

    2014-05-01

    Within the Decay Data Evaluation Project, as an example of a radioactive equilibrium with isomer, the (99)Mo/(99m)Tc equilibrium mixture decay characteristics are examined. The results of a new decay data evaluation are presented for (99)Mo/(99m)Tc decay to nuclear levels in (99)Tc. These evaluated data have been obtained using information published up to 2013. PMID:24309009

  3. Preoperative localization of parathyroid carcinoma using Tc-99m MIBI.

    PubMed

    Kitapçi, M T; Tastekin, G; Turgut, M; Caner, B; Kars, A; Barista, I; Bekdik, C

    1993-03-01

    A patient with parathyroid cancer is presented who underwent Tc-99m MIBI scintigraphy. The Tc-99m MIBI image demonstrated increased accumulation of activity at the lower pole of the left thyroid lobe which was later confirmed as a parathyroid cancer. Uptake by parathyroid cancer must be kept in mind as a cause of increased Tc-99m MIBI accumulation when a disease is in question in the thyroid or parathyroid gland. PMID:8462212

  4. Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by analytical characterization of radiopharmaceutical mixtures. Progress report, May 1, 1981-April 30, 1982

    SciTech Connect

    Heineman, W.R.; Deutsch, E.A.

    1981-12-01

    The objectives of this year's research were to develop a method for rapidly determining TcO/sub 4//sup -/ in /sup 99/Mo//sup 99m/Tc generator eluates, to improve the ability to chromatographically determine individual Tc-HEDP complexes in radiopharmaceuticals, and to investigate the effects of TcO/sub 4//sup -/ concentration and electrochemical reduction on the types and relative amounts of Tc-HEDP complexes present in a radiopharmaceutical formulation. A rapid and sensitive high performance liquid chromatographic (HPLC) method for the quantitative determination of pertechnetate (TcO/sub 4//sup -/) was developed. This HPLC-based analysis may be of considerable utility in assessing the history and function of /sup 99/MO/sup 99m/Tc generators as well as in the routine analysis of reduced technetium radiopharmaceuticals for the presence of undesired TcO/sub 4//sup -/. Encouraging results were obtained on a dimethyl amine column using aqueous (NH/sub 4/)/sub 2/SO/sub 4/ as the mobile phase. The preparation of Tc(NaBH/sub 4/) HEDP radiopharmaceutical analogues using varying concentrations of total TcO/sub 4//sup -/ shows a dramatic effect in the number and distribution of Tc-HEDP complexes over a TcO/sub 4//sup -/ concentration range of 10/sup -2/ to 10/sup -8/M. These results suggest that total TcO/sub 4//sup -/ concentration is an important parameter to be considered in the preparation of a specific Tc-HEDP complex to improve skeletal imaging. The preparation of Tc(electrode) HEDP radiopharmaceutical analogues by using electrochemical reduction was explored. The resulting solutions contain Tc-HEDP complexes that are tentatively identified as being the same complexes formed by NaBH/sub 4/ reduction, although the relative concentrations of these complexes are quite different with the two modes of reduction. Thus, electrochemical reduction shows promise as a viable route to the preparation of specific Tc-HEDP complexes for improved skeletal imaging.

  5. 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.

  6. 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.

  7. Expanding the Knowledge of the Geographic Distribution of Trypanosoma cruzi TcII and TcV/TcVI Genotypes in the Brazilian Amazon

    PubMed Central

    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

  8. 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. )

    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.

  9. 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.

    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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. RILEM TC ISR Summer 2015 Activity Report

    SciTech Connect

    Le Pape, Yann

    2015-08-01

    With aging infrastructures, instances of Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF), broadly covered under the term Internal Swelling Reaction (ISR), are increasingly being detected. They have been observed in bridges, dams, and most recently in nuclear power plants. Concrete swelling may result in bridge partial failure, dams with structural cracks and misaligned turbine shafts, and locked slice gates. For nuclear reactors micro-cracks may cause increased gas permeability which will jeopardize the containment integrity and may decrease the residual structural resistance under accidental loading. This TC, which limits its activity to structures with known expansive concrete, seeks to address two complementary but fundamental questions: a) What is the kinetics of the reaction and b) How would it affect the integrity of the structure (serviceability and strength) and thus establish a science based prognostic to the structure owner.

  15. Photoreduction of 99Tc pertechnetate by nanometer-sized metal oxides: new strategies for formation and sequestration of low-valent technetium.

    PubMed

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

    2011-11-23

    Technetium-99 ((99)Tc) (?(-)(max): 293.7 keV; t(1/2): 2.1 × 10(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 ((99)TcO(4)(-)) is stable. (99)TcO(4)(-) 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 (99)TcO(4)(-) and the chemical incorporation of the reduced (99)Tc into a metal oxide material. This strategy employs a single material, a polyoxometalate (POM), ?(2)-[P(2)W(17)O(61)](10-), that can be photoactivated in the presence of 2-propanol to transfer electrons to (99)TcO(4)(-) and incorporate the reduced (99)Tc covalently into the ?(2)-framework to form the (99)Tc(V)O species, (99)Tc(V)O(?(2)-P(2)W(17)O(61))(7-). This occurs via the formation of an intermediate species that slowly converts to (99)Tc(V)O(?(2)-P(2)W(17)O(61))(7-). Extended X-ray absorption fine structure and X-ray absorption near-edge spectroscopy analysis suggests that the intermediate consists of a (99)Tc(IV) ?(2)- species where the (99)Tc is likely bound to two of the four W-O oxygen atoms in the ?(2)-[P(2)W(17)O(61)](10-) defect. This intermediate then oxidizes and converts to the (99)Tc(V)O(?(2)-P(2)W(17)O(61))(7-) product. The reduction and incorporation of (99)TcO(4)(-) was accomplished in a "one pot" reaction using both sunlight and UV irradiation and monitored as a function of time using multinuclear nuclear magnetic resonance and radio thin-layer chromatography. The process was further probed by the "step-wise" generation of reduced ?(2)-P(2)W(17)O(61)(12-) through bulk electrolysis followed by the addition of (99)TcO(4)(-). The reduction and incorporation of ReO(4)(-), as a nonradioactive surrogate for (99)Tc, does not proceed through the intermediate species, and Re(V)O is incorporated quickly into the ?(2)-[P(2)W(17)O(61)](10-) defect. These observations are consistent with the periodic trends of (99)Tc and Re. Specifically, (99)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 the mechanisms of the reduction and incorporation of (99)Tc into a material. PMID:21985281

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. High Tc Superconducting Magnet Excited by a Semiconductor Thermoelectric Element

    NASA Astrophysics Data System (ADS)

    Kuriyama, T.; Ono, M.; Tabe, S.; Oguchi, A.; Okamura, T.

    2006-04-01

    A high Tc superconducting (HTS) magnet excited by a thermal electromotive force of a thermoelectric element is studied. This HTS magnet has the advantages of compactness, lightweight and continuous excitation in comparison with conventional HTS magnets, because this HTS magnet does not need a large external power source. In this system, a heat input into the cryogenic environment is necessary to excite the thermoelectric element for constant operation. This heat generation, however, causes a rise in temperature of an HTS coil and reduces the system performance. In this paper, a newly designed magnet system which adopted a two-stage GM cryocooler was investigated. It enabled us to control the temperature of a thermoelectric element and that of an HTS coil independently. The temperature of the HTS coil could be kept at 10-20 K at the second stage of the GM cryocooler, while the thermoelectric element could be excited at higher temperature in the range of 50-70 K at the first stage, where the performance of the thermoelectric element was higher. The experimental results on this HTS magnet are shown and the possibility of the thermoelectric element as a main power source of the HTS magnets is discussed.

  2. Tc1-like transposable elements in plant genomes

    PubMed Central

    2014-01-01

    Background The Tc1/mariner superfamily of transposable elements (TEs) is widespread in animal genomes. Mariner-like elements, which bear a DDD triad catalytic motif, have been identified in a wide range of flowering plant species. However, as the founding member of the superfamily, Tc1-like elements that bear a DD34E triad catalytic motif are only known to unikonts (animals, fungi, and Entamoeba). Results Here we report the identification of Tc1-like elements (TLEs) in plant genomes. These elements bear the four terminal nucleotides and the characteristic DD34E triad motif of Tc1 element. The two TLE families (PpTc1, PpTc2) identified in the moss (Physcomitrella patens) genome contain highly similar copies. Multiple copies of PpTc1 are actively transcribed and the transcripts encode intact full length transposase coding sequences. TLEs are also found in angiosperm genome sequence databases of rice (Oryza sativa), dwarf birch (Betula nana), cabbage (Brassica rapa), hemp (Cannabis sativa), barley (Hordium valgare), lettuce (Lactuta sativa), poplar (Populus trichocarpa), pear (Pyrus x bretschneideri), and wheat (Triticum urartu). Conclusions This study extends the occurrence of TLEs to the plant phylum. The elements in the moss genome have amplified recently and may still be capable of transposition. The TLEs are also present in angiosperm genomes, but apparently much less abundant than in moss. PMID:24926322

  3. 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.

  4. High -Tc superlight bipolarons in novel superconductors

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sasha

    2003-03-01

    Over the last decade, several competing models of high-temperature superconductivity (HTSC) have been proposed, none of which have succeeded to explain high values of the superconducting critical temperature Tc without adjustable parameters. Most of the proposed models are based on the short-range electron-electron correlations or/and on a short-range electron-phonon interaction. However, in the cuprates the screening is poor due to the low carrier density, layered crystal structure, and high ionicity of the lattice. Here we develop further a model of HTSC, which explicitly takes into account the long-range origin of both types of interaction [1]. The long-range electron-phonon (Froehlich) interaction binds carriers into real space pairs-small bipolarons with surprisingly low mass but sufficient binding energy, while the long-range Coulomb repulsion keeps them from forming larger clusters. We analytically solve this multi-polaron "Froelich-Coulomb" model of oxides for a zigzag ladder and a perovskite layer [2]. The model numerically explains high Tc values in the cuprates without any fitting parameters. It describes other key features of the cuprates such as the isotope effect on the effective mass, pseudogap, the normal state diamagnetism, anomalous upper critical field, and spectral functions measured in tunnelling and photoemission. We argue that strong coupling of carriers with high-frequency phonons and low Fermi energies is the cause of high critical temperatures of novel superconductors. [1] A.S. Alexandrov, in Models and Phenomenology for Conventional and High-temperature Superconductivity (Course CXXXVI of the International School of Physics`Enrico Fermi'), eds. G. Iadonisi, J.R. Schrieffer and M.L. Chiofalo, (IOS Press, Amsterdam), p. 309 (1998). [2] A.S. Alexandrov and P.E. Kornilovitch, J. Phys.: Condens. Matter 14 (2002) 5337. * Mailing address: Department of Physics, Loughborough University, Loughborough LE11 3TU, United Kingdom; E-mail: a.s.alexandrov@lboro.ac.uk; Phone: (44) 1509 223303; Fax: (44) 1509 223986.

  5. 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.

  6. STATISTICAL INFERENCE FOR TUMOR GROWTH INHIBITION T/C RATIO

    PubMed Central

    Wu, Jianrong

    2015-01-01

    The tumor growth inhibition T/C ratio is commonly used to quantify treatment effects in drug screening tumor xenograft experiments. The T/C ratio is converted to an antitumor activity rating using an arbitrary cutoff point and often without any formal statistical inference. Here, we applied a nonparametric bootstrap method and a small sample likelihood ratio statistic to make a statistical inference of the T/C ratio, including both hypothesis testing and a confidence interval estimate. Furthermore, sample size and power are also discussed for statistical design of tumor xenograft experiments. Tumor xenograft data from an actual experiment were analyzed to illustrate the application. PMID:20721784

  7. 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.

  8. 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

  9. (47171) 1999 TC36, A Transneptunian Triple

    E-print Network

    Benecchi, S D; Grundy, W M; Levison, H F

    2009-01-01

    We present new analysis of 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. The two central components, A1 and A2, can be consistently identified in each of nine epochs spread over seven years of time. In each instance the component separation, ranging from 0.023+/-0.002 to 0.031+/-0.003 arcsec, is roughly one half of the Hubble Space Telescope's diffraction limit at 606 nm. 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 10^18 kg derived from the orbit of the more distant secondary, component B. The diameters of the three components are dA1= 286(+45,-38) km, dA2= 265(+41,-35 km and dB= 139(+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 ...

  10. 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.

  11. Point nodes persisting far beyond Tc in Bi2212.

    PubMed

    Kondo, Takeshi; Malaeb, W; Ishida, Y; Sasagawa, T; Sakamoto, H; Takeuchi, Tsunehiro; Tohyama, T; Shin, S

    2015-01-01

    In contrast to a complex feature of antinodal state, suffering from competing orders, the pairing gap of cuprates is obtained in the nodal region, which therefore holds the key to the superconducting mechanism. One of the biggest question is whether the point nodal state as a hallmark of d-wave pairing collapses at Tc like the BCS-type superconductors, or it instead survives above Tc turning into the preformed pair state. A difficulty in this issue comes from the small magnitude of the nodal gap, which has been preventing experimentalists from solving it. Here we use a laser ARPES capable of ultrahigh-energy resolution, and detect the point nodes surviving far beyond Tc in Bi2212. By tracking the temperature evolution of spectra, we reveal that the superconductivity occurs when the pair-breaking rate is suppressed smaller than the single-particle scattering rate on cooling, which governs the value of Tc in cuprates. PMID:26158431

  12. Point nodes persisting far beyond Tc in Bi2212

    PubMed Central

    Kondo, Takeshi; Malaeb, W.; Ishida, Y.; Sasagawa, T.; Sakamoto, H.; Takeuchi, Tsunehiro; Tohyama, T.; Shin, S.

    2015-01-01

    In contrast to a complex feature of antinodal state, suffering from competing orders, the pairing gap of cuprates is obtained in the nodal region, which therefore holds the key to the superconducting mechanism. One of the biggest question is whether the point nodal state as a hallmark of d-wave pairing collapses at Tc like the BCS-type superconductors, or it instead survives above Tc turning into the preformed pair state. A difficulty in this issue comes from the small magnitude of the nodal gap, which has been preventing experimentalists from solving it. Here we use a laser ARPES capable of ultrahigh-energy resolution, and detect the point nodes surviving far beyond Tc in Bi2212. By tracking the temperature evolution of spectra, we reveal that the superconductivity occurs when the pair-breaking rate is suppressed smaller than the single-particle scattering rate on cooling, which governs the value of Tc in cuprates. PMID:26158431

  13. Point nodes persisting far beyond Tc in Bi2212

    NASA Astrophysics Data System (ADS)

    Kondo, Takeshi; Malaeb, W.; Ishida, Y.; Sasagawa, T.; Sakamoto, H.; Takeuchi, Tsunehiro; Tohyama, T.; Shin, S.

    2015-07-01

    In contrast to a complex feature of antinodal state, suffering from competing orders, the pairing gap of cuprates is obtained in the nodal region, which therefore holds the key to the superconducting mechanism. One of the biggest question is whether the point nodal state as a hallmark of d-wave pairing collapses at Tc like the BCS-type superconductors, or it instead survives above Tc turning into the preformed pair state. A difficulty in this issue comes from the small magnitude of the nodal gap, which has been preventing experimentalists from solving it. Here we use a laser ARPES capable of ultrahigh-energy resolution, and detect the point nodes surviving far beyond Tc in Bi2212. By tracking the temperature evolution of spectra, we reveal that the superconductivity occurs when the pair-breaking rate is suppressed smaller than the single-particle scattering rate on cooling, which governs the value of Tc in cuprates.

  14. A search for technetium (Tc II) in barium stars

    NASA Technical Reports Server (NTRS)

    Little-Marenin, Irene R.; Little, Stephen J.

    1987-01-01

    The authors searched without success for the lines of Tc II at 2647.02, 2610.00 and 2543.24 A in IUE spectra of the barium stars HR 5058, Omicron Vir, and Zeta Cap. The lack of Tc II implies that the observed s-process enhancements were produced more than half a million years ago and supports the suggestion that the spectral peculiarities of barium stars are probably related to the binary nature of the stars.

  15. Tc-99m white cell scintigraphy in suspected acute infection

    SciTech Connect

    Southee, A.E.; Lee, K.J.; McLaughlin, A.F.; Borham, P.W.; Bautovich, G.J.; Morris, J.G. )

    1990-02-01

    The usefulness of In-111 labeled white cells in acute infection is well documented but the role of Tc-99m labeled white cell scintigraphy (WCS) has not been as clearly established. Using stannous fluoride colloid and a simple labelling procedure with 20 ml of autologous whole blood, three cases are presented in which Tc-99m WCS established unexpected diagnoses in patients who had remained undiagnosed despite extensive investigation.

  16. Trypanosoma cruzi TcSRPK, the first protozoan member of the SRPK family, is biochemically and functionally conserved with metazoan SR protein-specific kinases.

    PubMed

    Portal, Daniel; Lobo, Guillermo S; Kadener, Sebastián; Prasad, Jayendra; Espinosa, Joaquín M; Pereira, Claudio A; Tang, Zhaohua; Lin, Ren-Jang; Manley, James L; Kornblihtt, Alberto R; Flawiá, Mirtha M; Torres, Héctor N

    2003-03-01

    A novel SR protein-specific kinase (SRPK) from the SRPK family was identified for the first time in a protozoan organism. The primary structure of the protein, named TcSRPK, presents a significant degree of identity with other metazoan members of the family. In vitro phosphorylation experiments showed that TcSRPK has the same substrate specificity relative to other SRPKs. TcSRPK was able to generate a mAb104-recognized phosphoepitope, a SRPK landmark. Expression of TcSRPK in different Schizosaccharomyces pombe strains lead to conserved phenotypes, indicating that TcSRPK is a functional homologue of metazoan SRPKs. In functional alternative splicing assays in vivo in HeLa cells, TcSRPK enhanced SR protein-dependent inclusion of the EDI exon of the fibronectin minigene. When tested in vitro, it inhibited splicing either on nuclear extracts or on splicing-deficient S100 extracts complemented with ASF/SF2. This inhibition was similar to that observed with human SRPK1. This work constitutes the first report of a member of this family of proteins and the existence of an SR-network in a protozoan organism. The implications in the origins and control of splicing are discussed. PMID:12615332

  17. 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.

  18. Cross-sections for formation of 99mTc through natRu(n,x) 99mTc reaction induced by neutrons at 13.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Luo, Junhua; Han, Jiuning; Tuo, Fei; Kong, Xiangzhong; Liu, Rong; Jiang, Li

    2012-05-01

    The cross-sections for formation of metastable state of 99Tc (99mTc, 140.511 keV, 6.01 h) through natRu(n,x)99mTc reaction induced by 13.5 MeV and 14.8 MeV neutrons were measured. Fast neutrons were produced via the 3H(d,n)4He reaction on the K-400 neutron generator. Induced gamma activities were measured by a high-resolution gamma-ray spectrometer with a high-purity germanium (HpGe) detector. Measurements were corrected for gamma-ray attenuations, dead time and fluctuation of neutron flux. Data for natRu(n,x)99mTc reaction cross sections are reported to be 9.6±1.5 and 9.2±1.1 mb at 13.5±0.2 and 14.8±0.2 MeV incident neutron energies, respectively. Results were compared with the data by other anthors.

  19. 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.

  20. Electroweak Chiral Lagrangian from TC2 Model with nontrivial TC fermion condensation and walking

    E-print Network

    Feng-Jun Ge; Shao-Zhou Jiang; Qing Wang

    2011-04-29

    The electroweak chiral Lagrangian for the topcolor assisted technicolor model proposed by K. Lane, which uses nontrivial patterns of techniquark condensation and walking, was investigated in this study. We found that the features of the model are qualitatively similar to those of Lane's previous natural TC2 prototype model, but there is no limit on the upper bound of the Z' mass. We discuss the phase structure and possible walking behavior of the model. We obtained the values of all coefficients of the electroweak chiral Lagrangian up to an order of p4. We show that although the walking effect reduces the S parameter to half its original value, it maintains an order of 2. Moreover, a special hyper-charge arrangement is needed to achieve further reductions in its value.

  1. 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.

  2. Development of Tc-99m Imaging Agents for Abeta Plaques

    SciTech Connect

    Zhi-Ping, Zhuang; Mei-Ping Kung; Catherihne Hou; Hank F. Kung

    2008-09-26

    Development of SPECT imaging agents based on Tc-99m targeting A? plaques is useful for diagnosis of Alzheimer’s disease (AD). A stilbene derivative, [11C]SB-13, showing promise in detecting senile plaques present in AD patients has been reported previously1,2. Based on the 4’-amino-stilbene core structure we have added substituted groups through which a chelating group, N2S2, was conjugated. We report herein a series of Tc-99m labeled stilbene derivative conjugated with a TcO[N2S2] core. The syntheses of stilbenes containing a N2S2 chelating ligand are achieved by a scheme shown. Lipophilic 99mTc stilbene complexes were successfully prepared and purified through HPLC. Preliminary results of in vitro labeling of brain sections from transgenic mice showed very promising plaque labeling. These 99mTc stilbene derivatives are warranted for further evaluations as potential imaging agents targeting amyloid plaques.

  3. Iron phosphate glass for immobilization of 99Tc

    SciTech Connect

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

    2013-06-15

    Technetium-99 (99Tc) can bring serious environmental threats because of its long half-life (t1/2 = ~2.1 x 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.

  4. 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.

  5. 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.

  6. 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…

  7. 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.

  8. Topological susceptibility near Tc in SU(3) gauge theory

    NASA Astrophysics Data System (ADS)

    Xiong, Guang-Yi; Zhang, Jian-Bo; Chen, Ying; Liu, Chuan; Liu, Yu-Bin; Ma, Jian-Ping

    2016-01-01

    Topological charge susceptibility ?t for pure gauge SU(3) theory at finite temperature is studied using anisotropic lattices. The over-improved stout-link smoothing method is utilized to calculate the topological charge. Near the phase transition point we find a rapid declining behavior for ?t with values decreasing from (188 (1) MeV) 4 to (67 (3) MeV) 4 as the temperature increased from zero temperature to 1.9Tc which demonstrates the existence of topological excitations far above Tc. The 4th order cumulant c4 of topological charge, as well as the ratio c4 /?t is also investigated. Results of c4 show step-like behavior near Tc while the ratio at high temperature agrees with the value as predicted by the diluted instanton gas model.

  9. Leukocyte labeling with isonitrile complexes of Tc-99m

    SciTech Connect

    Van den Abbeele, A.D.; Solorzano, C.; Jones, A.G.; Beardsley, D.S.; Treves, S.; Davison, A.

    1985-05-01

    Leukocyte labelling with Tc-99m may result in a useful method for the detection and localization of active inflammatory processes in patients, particularly in the pediatric population. Previous studies qin this laboratory have shown that hexakis(alkylisonitrile)technetium(I) complexes readily label V79 lung fibroblasts in vitro, and this work is now being extended to isolated human white blood cells (WBC). Two lipophilic water-soluble technetium cations, the t-butyl (Tc-99m(TBI)) and cyclohexyl (Tc-99m(CHI)) analogs, were prepared essentially ligand-free at no-carrier-added levels in aqueous media and introduced in 10% propylene glycol/90% normal saline solution to WBC at room temperature. The cells were isolated from whole blood via sedimentation, centrifugation, and hypotonic hemolysis of the red blood cells. The labeling yield was studied as a function of incubation time (10-45 min), amount of activity (0.35-8.0 mCi), and total WBC (2.5 x 10/sup 7/-1.3 x 10/sup 8/). After 10 min incubation using 10/sup 8/ cells, the initial uptake of Tc-99m(TBI) was 40%, of which 50% remained bound after one saline wash. By contrast, the labeling efficiency with Tc-99m(CHI) was 85%, with 90% of the label still bound after washing. The labeling yield was unrelated to activity levels of incubation time, but was proportional to the number of WBC present. The entire process could be complemented in approximately one hour. The labeling yields with Tc-99m-(CHI) are comparable to those now obtained with the clinically available In-111 oxine.

  10. Superfluid Stiffness and Tc Enhancement in Cuprate Heterostructures

    NASA Astrophysics Data System (ADS)

    Goren, Lilach

    The basic electronic correlations underlying the effect of high Tc superconductivity in cuprates, still elude a complete and unified theoretical description. This thesis deals with several central open questions regarding the crucial aspects that determine superconductivity in cuprates. A key question concerns the nature of the phase which is formed when superconductivity is destroyed. The origin of the 'pseudogap' in the density of states above Tc is not clear to this day. We address this question by investigating the destruction of superconductivity at T = 0 as current is applied. We design novel Gutzwiller projected variational states, that incorporate supercurrent in a d-wave BCS wave-function. We identify two different mechanisms which determine the critical current at which superconductivity is destroyed: at high hole doping [special characters omitted] it occurs when quasiparticle pockets completely destroy the gap in a BCS-like mechanism. In the underdoped regime the mechanism is bosonic, whereby the critical current is set by a maximal phase twist which destroys the superfluid stiffness with pairing still intact. This result is indicative of a pseudogapped 'normal' state which retains pairing correlations. Moreover, we find a dome shaped critical current as a function of doping, similar to Tc. A second question concerns the determination of Tc and in particular possible ways to increase it in cuprate heterostructures. We investigate two possible scenarios that are aimed at profiting from proximity between a largegap underdoped and a large carrier density overdoped cuprate material. In the first scenario we consider an underdoped-overdoped bilayer and find a possible Tc enhancement, assuming a relatively high interlayer coupling. In the second case, we investigate underdoped-overdoped in-plane inhomogeneity. There, the coupling is naturally high, and the proximity effect can be strong. For a microscopic doping inhomogeneity we find an enhancement of Tc beyond its maximal value in the uniform superconductors.

  11. Radionuclide imaging of myocardial infarction using Tc-99m TBI

    SciTech Connect

    Holman, B.L.; Campbell, S.; Kirshenbaum, J.M.; Lister-James, J.; Jones, A.G.; Davison, A.; Antman, E.

    1985-05-01

    The cationic complex Tc-99m t-butylisonitrile (TBI) concentrates in the myocardial tissue of several animal species. Its myocardial distribution is proportional to blood flow both in zones of ischemia and in normal myocardium at rest. Planar, tomographic, and gated myocardial images have been obtained using Tc-99m TBI in the human. The authors investigated the potential application of Tc-99m TBI imaging to detect and localize myocardial infarction. Four subjects without clinical evidence of cardiovascular disease and five patients with ECG evidence of previous myocardial infarction were studied. Tc-99m TBI (10mCi) was injected intravenously with the patient in a resting state with planar imaging in the anterior, 30 and 70 degree LAO projections beginning one hr after injection. The distribution of the tracer was homogeneous throughout the left ventricular wall in the normal subjects. Regional perfusion defects were present in 4/5 of the patients with myocardial infarction. Location of the defects corresponded to the location of the infarct using ECG criteria (2 inferoposterior and 2 anterior). The patient in whom the Tc-99m TBI image appeared normal had sustained a subendocardial myocardial infarct which could not be localized by ECG; the other 4 pts had transmural infarcts. Anterior and 30 degree LAO images were of excellent quality in all cases; there was overlap of the liver on the inferior wall of the left ventricle on the 70 degree LAO views. The authors conclude that accurate perfusion imaging may be possible using Tc-99m TBI in patients with transmural myocardial infarction.

  12. Tc-99m-labeled RGD-conjugated alpha-melanocyte stimulating hormone hybrid peptides with reduced renal uptake.

    PubMed

    Yang, Jianquan; Hu, Chien-An A; Miao, Yubin

    2015-04-01

    The purpose of this study was to examine whether the replacement of the positively-charged Lys or Arg linker with a neutral linker could reduce the renal uptake of Arg-Gly-Asp (RGD)-conjugated alpha-melanocyte stimulating hormone (?-MSH) hybrid peptide. The RGD motif {cyclic(Arg-Gly-Asp-DTyr-Asp)} was coupled to [Cys(3,4,10), D-Phe(7), Arg(11)]?-MSH3-13 {(Arg(11))CCMSH} through the neutral ?Ala or Ahx {aminohexanoic acid} linker (replacing the Lys or Arg linker) to generate novel RGD-?Ala-(Arg(11))CCMSH and RGD-Ahx-(Arg(11))CCMSH hybrid peptides. The receptor-binding affinity and cytotoxicity of RGD-?Ala-(Arg(11))CCMSH and RGD-Ahx-(Arg(11))CCMSH were determined in B16/F1 melanoma cells. The melanoma targeting and imaging properties of (99m)Tc-RGD-?Ala-(Arg(11))CCMSH and (99m)Tc-RGD-Ahx-(Arg(11))CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The replacement of the Lys or Arg linker with the ?Ala or Ahx linker retained nanomolar receptor-binding affinities and remarkable cytotoxicity of RGD-?Ala-(Arg(11))CCMSH and RGD-Ahx-(Arg(11))CCMSH. The receptor-binding affinities of RGD-?Ala-(Arg(11))CCMSH and RGD-Ahx-(Arg(11))CCMSH were 0.8?±?0.05 and 1.3?±?0.1 nM. Three-hour incubation with 0.1 µM of RGD-?Ala-(Arg(11))CCMSH and RGD-Ahx-(Arg(11))CCMSH decreased the survival percentages of B16/F1 cells by 71 and 67 % as compared to the untreated control cells 5 days post the treatment. The replacement of the Arg linker with the ?Ala or Ahx linker reduced the non-specific renal uptake of (99m)Tc-RGD-?Ala-(Arg(11))CCMSH and (99m)Tc-RGD-Ahx-(Arg(11))CCMSH by 62 and 61 % at 2 h post-injection. (99m)Tc-RGD-?Ala-(Arg(11))CCMSH displayed higher melanoma uptake than (99m)Tc-RGD-Ahx-(Arg(11))CCMSH at 0.5, 2, 4, and 24 h post-injection. Enhanced tumor to kidney uptake ratio of (99m)Tc-RGD-?Ala-(Arg(11))CCMSH warranted the further evaluation of (188)Re-labeled RGD-?Ala-(Arg(11))CCMSH as a novel MC1 receptor-targeting therapeutic peptide for melanoma treatment in the future. PMID:25557051

  13. 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

  14. 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.

  15. The Problem of Mass: Mesonic Bound States Above Tc

    E-print Network

    H. -J. Park; C. -H. Lee; G. E. Brown; M. Rho

    2005-09-12

    By extending the Bielefeld LGS (Lattice Gauge Simulation) color singlet interaction, we find that the masses of pi, sigma, rho and a_1 excitations, 32 degrees of freedom in all, go to zero (in the chiral limit) as T -> T_c. This result indicates a smooth phase transition at T_c, at which from above the masses and couplings of mesons vanish `a la Brown-Rho scaling. We discuss that our scenario successfully explains the STAR (STAR Collaboration) rho^0/pi^- ratio in Au-Au peripheral collisions at RHIC.

  16. trans-K3[TcO2(CN)4

    SciTech Connect

    Chatterjee, Sayandev; Del Negro, Andrew S.; Edwards, Matthew K.; Twamley, Brendan; Krause, Jeanette A.; Bryan, Samuel A.

    2010-07-14

    The dioxotetracyanotechnetate anion, [TcO2(CN)4]3-, of the title complex has octahedral symmetry. The technetium is located on a center of inversion and is bound by two oxygen atoms and four cyano ligands. The Tc?O bond distance of 1.7721 (12) Å is consistent with double bond character. The potassium cations [located on special (1/2,0,1) and general positions] reside in octahedral or tetrahedral environments; interionic K···O and K···N interactions occur in the 2.7877 (19)-2.8598 (15) Å range.

  17. 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.

  18. Mathematics and Science: Female Students and LEGO TC Logo.

    ERIC Educational Resources Information Center

    Hutchinson, Elaine J.; Whalen, Mary T.

    1995-01-01

    Describes a three-week workshop involving 20 teachers and 40 female students, grades 3 through 8, who worked in small groups to use the LEGO TC logo program, an approach that integrates mathematics and science instruction. Discussion includes the impact of single-sex, small group work on student attitudes toward mathematics and science. (six…

  19. DOT/FAA/TC-14/49 Federal Aviation Administration

    E-print Network

    Koopman, Philip

    DOT/FAA/TC-14/49 Federal Aviation Administration William J. Hughes Technical Center Aviation. U.S. Department of Transportation Federal Aviation Administration #12;NOTICE This document as to its use. This report is available at the Federal Aviation Administration William J. Hughes Technical

  20. TcBA-AR VII 2004 A DENDROCHRONOLOGICAL FRAMEWORK

    E-print Network

    Manning, Sturt

    TcBA-AR VII 2004 A DENDROCHRONOLOGICAL FRAMEWORK FOR THE ASSYRIAN COLONY PERIOD IN ASIA MINOR: Dendrochronology, radiocarbon, Middle Bronze Age, Assyrian Colony Period, wiggle-matching Anahtar sbzcukler: Agas Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology, Cornell University, Ithaca, N

  1. 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.

  2. Universitt Rostock Affine Image Matching is TC0

    E-print Network

    Lonardi, Stefano

    An and let p = (a1, . . . , a6)T , p = (a1, . . . , a6)T Christian Hundt Affine Image Matching is TC0.5-1.5 1.5 -1.5 Theorem Let An and let p = (a1, . . . , a6)T , p = (a1, . . . , a6)T represent f and f

  3. Simultaneous ??m?Tc-MDP/¹²³I-MIBG imaging of neuroblastoma using SPECT-CT

    E-print Network

    Pérez-Gutiérrez, José P. (José Pablo Andrés)

    2011-01-01

    Simultaneous ??m??Tc-MDP/ ¹²³I-MIBG SPECT has the potential to replace current clinical sequential acquisitions of ??m?Tc-MDP and ¹²³-MIBG SPECT studies, and therefore has great potential to reduce imaging time, sedation ...

  4. 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.

  5. Vibration reduction using autoparametric resonance in a high-Tc superconducting levitation system

    NASA Astrophysics Data System (ADS)

    Yamasaki, Hiroshi; Takazakura, Toyoki; Sakaguchi, Ryunosuke; Sugiura, Toshihiko

    2014-05-01

    High-Tc superconducting levitation systems have very small damping and enable stable levitation without control. Therefore, they can be applied to various kinds of application. However, there are some problems that small damping produces large vibration and nonlinearity of magnetic force can generate complicated phenomena. Accordingly, analysis of these phenomena and reduction of vibration occurring in the system are important. In this study, we examined reduction of vibration without using any absorbers, but utilizing autoparametric resonance caused by nonlinear coupling between vertical oscillation and horizontal oscillation. We conducted numerical analysis and experiments in order to investigate motions of a rigid bar levitated by the electromagnetic force from high-Tc superconductors. As a result, if the ratio of the natural frequency of vertical oscillation and that of horizontal oscillation is two to one, the vertical oscillation decreases while the horizontal oscillation is excited. Thus, it was confirmed that the amplitude of a primary resonance can be reduced by occurrence of autoparametric resonance without using any absorbers.

  6. Synthesis, characterization and biodistribution of a new technetium-99m complex with trimethylsilylmethylisonitrile. Comparison with 99mTc-TBI and 99mTc-MIBI.

    PubMed

    Bouquillon, S; Coulais, Y; Dartiguenave, M; Tafani, J A; Guiraud, R

    1995-07-01

    An isonitrile ligand with a silicium component was synthesized and a copper salt of this ligand was then used to form a 99mTc complex. We evaluated the physicochemical characteristics of the complex and its biodistribution in rat. The chemical properties, i.e. lipophilic affinity and charge, were comparable to those of other 99mTc complexes formed with similar isonitrile compounds (99mTc-MIBI and 99mTc-TBI). In contrast, the tissue biodistribution of this new technetium complex differed markedly, as it was mainly taken up in the liver and not at all in the heart. PMID:7581167

  7. 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.

  8. The production of patient dose level 99mTc medical radioisotope using laser-driven proton beams

    NASA Astrophysics Data System (ADS)

    Clarke, R.; Dorkings, S.; Neely, D.; Musgrave, I.

    2013-05-01

    The medical isotope 99mTc (technetium) is used in over 30 million nuclear medical procedures annually, accounting for over 80% of the worldwide medical isotope usage. Its supply is critical to the medical community and a worldwide shortage is expected within the next few decades as current fission reactors used for its generation reach their end of life. The cost of build and operation of replacement reactors is high and as such, alternative production mechanisms are of high interest. Laser-accelerated proton beams have been widely discussed as being able to produce Positron Emission Tomography (PET) isotopes once laser architecture evolved to high repetition rates and energies. Recent experimental results performed on the Vulcan Laser Facility in the production of 99mTc through 100Mo (p,2n) 99mTc demonstrate the ability to produce this critical isotope at the scales required for patient doses using diode pumped laser architecture currently under construction. The production technique, laser and target requirements are discussed alongside a timeline and cost for a prototype production facility.

  9. 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.

  10. Highly Oxidizing Excited States of Re and Tc Complexes

    SciTech Connect

    Del Negro, Andy S.; Seliskar, Carl J.; Heineman, William R.; Hightower, Sean E.; Bryan, Samuel A.; Sullivan, Brian P.

    2006-12-27

    Like the Re analog, the ligand-to-metal charge transfer (LMCT) excited state of [Tc(dmpe)3]2+* (dmpe is bis-1,2-(dimethylphosphino)ethane) is luminescent in solution at room temperature. Surprisingly, both [M(dmpe)3]2+* species have extremely oxidizing excited state potentials (ESPs)-the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M=Re(Tc); E1/2*=+2.61(2.52)V vs. SCE; ?max =526(585) nm). Using a Rehm-Weller analysis with a series of aromatic hydrocarbons as electron transfer quenchers, E1/2(Re2+*/Re+) has been determined to be 2.58 V, in good agreement with the calculated value. Both [M(dmpe)3]2+* species are quenched by chloride ion and both can function as excited state oxidants in water solution.

  11. Pharmacokinetics of intravenously injected Tc-99m labeled ferrite nanobeads

    NASA Astrophysics Data System (ADS)

    Fu, Chao-Ming; Wang, Yuh-Feng; Guo, Yu-Feng; Wang, Li-Shin; Chuang, May-Haw; Cham, Thau-Ming

    2009-04-01

    We study the time varying biodistribution of ferrite (Fe3O4) nanoparticles upon in vivo injection. For this purpose, a novel process of directly labeling radioactive Tc-99m with ferrite nanoparticles was developed. The radiobeads serve as a tracer to provide information on the uptake of injected particles by organs. In the course of our study, Tc-99m labeled ferrite beads were intravenously injected into the tail vein of rats. The time course of changes in the radio-intensity of heart, lung, and liver could be achieved by real-time scintigraphic images. It was observed that the particle uptake by organs is very fast and completed within the first few minutes after intravenous injection. The pharmacokinetic behavior of the radiobead uptake was quantitatively described by a two-compartment model.

  12. Focal uptake of Tc-99m MDP in a gossypiboma.

    PubMed

    Thomas, Bejoy G; Silverman, Eugene D

    2008-04-01

    A 51-year-old Korean woman with a history of breast cancer underwent screening bone scintigraphy, which revealed minimal soft tissue uptake of Tc-99m methylene diphosphonate (MDP) in the right lower quadrant. CT and plain films confirmed that the uptake was due to a retained surgical sponge or gossypiboma. The incidence of gossypibomas has been reported at high as 1 in 1000 to 15,000 intra-abdominal operations. The natural progression of an aseptic gossypiboma is a foreign body reaction and granuloma formation. This inflammatory granulomatous reaction is the most likely cause of the extraosseous accumulation of Tc-99m MDP. This entity should be added to the already extensive list of etiologies of extraosseous MDP accumulation. PMID:18356674

  13. NMR/MRI with hyperpolarized gas and high Tc SQUID

    DOEpatents

    Schlenga, Klaus (Eggenstein, DE); de Souza, Ricardo E. (Recife, BR); Wong-Foy, Annjoe (Berkeley, CA); Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA)

    2000-01-01

    A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

  14. 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.

  15. ''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.

  16. Tc-99m pyrophosphate myocardial scanning in Chagas' disease

    SciTech Connect

    Goncalves da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

    1981-04-01

    Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas's disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

  17. Tc-99m pyrophosphate myocardial scanning in Chagas' disease

    SciTech Connect

    da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

    1981-04-01

    Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas' disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

  18. 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.

  19. New routes for production of proton-rich Tc isotopes

    SciTech Connect

    Maiti, Moumita; Lahiri, Susanta

    2010-02-15

    Proton-rich Tc radionuclides have been identified as potential candidates for specific clinical and biological applications in the last decade. So far, these radionuclides have been produced either by proton-induced reaction on Mo targets or {alpha}-particle-induced reaction on Nb targets. This article lightens two heavy-ion-induced production routes of {sup 93,94,95,96}Tc radionuclides through {sup 7}Li+{sup nat}Zr and {sup 9}Be+{sup nat}Y reactions and provides important cross-sectional information in the projectile energy ranges 37-45 MeV and 30-48 MeV, respectively. Excitation functions of those reactions have been measured using the stacked-foil technique followed by the off-line {gamma}-spectrometric studies. Measured cross-sectional data have been interpreted comparing theoretical predictions of the two nuclear reaction model codes PACE-II and ALICE91. Experimental cross sections agreed with the theory. Measured production cross sections of {sup 94,95}Tc have been compared with those produced from the {alpha}+{sup 93}Nb reaction.

  20. [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

  1. Fiscal Year 2010 Summary Report on the Epsilon-Metal Phase as a Waste Form for 99 Tc

    SciTech Connect

    Strachan, Denis M.; Crum, Jarrod V.; Buck, Edgar C.; Riley, Brian J.; Zumhoff, Mac R.

    2010-09-30

    Epsilon metal (?-metal) is generated in nuclear fuel during irradiation. This metal consists of Pd, Ru, Rh, Mo, and some Te. These accumulate at the UO2 grain boundaries as small (ca 5 µm) particles. These metals have limited solubility in the acid used to dissolve fuel during reprocessing and in typical borosilicate glass. These must be treated separately to improve overall waste loading in glass. This low solubility and their survival in 2 Gy-old natural reactors led us to investigate them as a waste form for the immobilization of 99Tc and 107Pd, two very long-lived isotopes.

  2. 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

  3. 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

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

    SciTech Connect

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

    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)

  5. Nuclear shape and structure in neutron-rich {sup 110,111}Tc

    SciTech Connect

    Luo, Y. X.; Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Gore, P. M.; Jones, E. F.; Fong, D.; Rasmussen, J. O.; Lee, I. Y.; Stefanescu, I.; Che, X. L.; Zhu, S. J.; Wu, S. C.; Ginter, T. N.; Ma, W. C.; Ter-Akopian, G. M.; Daniel, A. V.; Stoyer, M. A.; Donangelo, R.; Gelberg, A.

    2006-08-15

    The high-spin nuclear structure of Tc isotopes is extended to more neutron-rich regions based on the measurements of prompt {gamma} rays from the spontaneous fission of {sup 252}Cf at the Gammasphere. The high-spin level scheme of N=67 neutron-rich {sup 110}Tc (Z=43) is established for the first time, and that of {sup 111}Tc is extended and expanded. The ground band of {sup 111}Tc reaches the band-crossing region, and the new observation of the weakly populated {alpha}=-1/2 member of the band provides important information on signature splitting. The systematics of band crossings in the isotopic and isotonic chains and a CSM calculation suggest that the band crossing of the ground band of {sup 111}Tc is due to alignment of a pair of h{sub 11/2} neutrons. The best fit to signature splitting, branching ratios, and excitations of the ground band of {sup 111}Tc by the rigid triaxial rotor plus particle model calculations result in a shape of {epsilon}{sub 2}=0.32 and {gamma}=-26 deg. for this nucleus. Its triaxiality is larger than that of {sup 107,109}Tc, which indicates increasing triaxiality in Tc isotopes with increasing neutron number. The identification of the weakly populated K+2 satellite band provides strong evidence for the large triaxiality of {sup 111}Tc. In {sup 110}Tc, the four lowest-lying levels observed are very similar to those in {sup 108}Tc. At an excitation of 478.9 keV above the lowest state observed, ten states of a {delta}I=1 band are observed. This band of {sup 110}Tc is very analogous to the {delta}I=1 bands in {sup 106,108}Tc, but it has greater and reversal signature splitting at higher spins.

  6. Isostructural Re(I)/(99m)Tc(I) tricarbonyl complexes for cancer theranostics.

    PubMed

    Nunes, Patrique; Morais, Goreti Ribeiro; Palma, Elisa; Silva, Francisco; Oliveira, Maria Cristina; Ferreira, Vera F C; Mendes, Filipa; Gano, Lurdes; Vicente Miranda, Hugo; Outeiro, Tiago F; Santos, Isabel; Paulo, António

    2015-05-14

    Merging classical organic anticancer drugs with metal-based compounds in one single molecule offers the possibility of exploring new approaches for cancer theranostics, i.e. the combination of diagnostic and therapeutic modalities. For this purpose, we have synthesized and biologically evaluated a series of Re(I)/(99m)Tc(I) tricarbonyl complexes (Re1–Re4 and Tc1–Tc4, respectively) stabilized by a cysteamine-based (N,S,O) chelator and containing 2-(4?-aminophenyl)benzothiazole pharmacophores. With the exception of Re1, all the Re complexes have shown a moderate cytotoxicity in MCF7 and PC3 cancer cells (IC50 values in the 15.9–32.1 ?M range after 72 h of incubation). The cytotoxic activity of the Re complexes is well correlated with cellular uptake that was quantified using the isostructural (99m)Tc congeners. There is an augmented cytotoxic effect for Re3 and Re4 (versusRe1 and Re2), and the highest cellular uptake for Tc3 and Tc4, which display a long ether-containing linker to couple the pharmacophore to the (N,S,O)-chelator framework. Moreover, fluorescence microscopy clearly confirmed the cytosolic accumulation of the most cytotoxic compound (Re3). Biodistribution studies of Tc1–Tc4 in mice confirmed that these moderately lipophilic complexes (logDo/w = 1.95–2.32) have a favorable bioavailability. Tc3 and Tc4 presented a faster excretion, as they undergo metabolic transformations, in contrast to complexes Tc1 and Tc2. In summary, our results show that benzothiazole-containing Re(I)/(99m)Tc(I) tricarbonyl complexes stabilized by cysteamine-based (N,S,O)-chelators have potential to be further applied in the design of new tools for cancer theranostics. PMID:25849043

  7. Differential Lung Uptake of 99mTc-HMPAO and 99mTc-Duramycin in the Chronic Hyperoxia Rat Model

    PubMed Central

    Clough, Anne V.; Audi, Said H.; Haworth, Steven T.; Roerig, David L.

    2015-01-01

    Noninvasive radionuclide imaging has the potential to identify and assess mechanisms involved in particular stages of lung injury which occur with acute respiratory distress syndrome, for example. Lung uptake of 99mTc-hexamethylpropyleneamine oxime (HMPAO) is reported to be partially dependent on the redox status of the lung tissue while 99mTc-duramycin, a new marker of cell injury, senses cell death via apoptosis and/or necrosis. Thus, we investigated changes in lung uptake of these agents in rat exposed to hyperoxia for prolonged periods, a common model of acute lung injury. Methods Male Sprague-Dawley rats were pre-exposed to either normoxia (21% O2) or hyperoxia (85% O2) for up to 21 days. For imaging, the rats were anesthetized, injected i.v. with either 99mTc-HMPAO or 99mTc-duramycin (37-74 MBq) and planar images were acquired using a high sensitivity modular gamma camera. Subsequently, 99mTc-macroagreggated albumin (37 MBq, diam=10-40 ?m) was injected i.v., imaged, and used to define a lung region-of-interest. The lung to background ratio was used as a measure of lung uptake. Results Hyperoxia exposure resulted in a 74% increase in 99mTc-HMPAO lung uptake, which peaked at 7 days and persisted for the 21 days of exposure. 99mTc-duramycin lung uptake was also maximal at 7 days of exposure but decreased to near control levels by 21 days. The sustained elevation of 99mTc-HMPAO uptake suggests ongoing changes in lung redox status whereas cell death appears to have subsided by 21 days. Conclusion These results suggest the potential use of 99mTc-HMPAO and 99mTc-duramycin as redox and cell-death imaging biomarkers, respectively, for in vivo identification and assessment of different stages of lung injury. PMID:23086010

  8. Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by analytical characterization of radiopharmaceutical mixtures

    SciTech Connect

    Heineman, W.R.

    1992-01-24

    The long-range objective of this research program is the development of more efficacious technetium-99m radiopharmaceuticals for use as imaging agents in diagnostic nuclear medicine. We seek to isolate and develop distinct site imaging agents, each of which has properties optimized to provide diagnostic information concerning a given pathological condition. The specific objectives during the period (9/1/89 to 8/31/92) include: (1) Development of strategies for improving yields of specific Tc-diphosphonate complexes with optimum imaging properties; (2) Development of electrodes for rapid in situ electrochemical generation of skeletal imaging agents; (3) Development of electrochemical sensors for {Tc} and Re imaging agents; (4) Characterization of stable {Tc}- and Re-diphosphonate complexes obtainable in high yield by structural studies with techniques such as NMR, EXAFS, and Raman spectroscopy; (5) Development of improved separation techniques for the characterization of diphosphonate skeletal imaging agents; (6) Evaluation of the effect of the biological milieu on {Tc}-diphosphonate complexes; and (7) Electrochemical studies of technetium and rhenium complexes synthesized by Professor Deutsch's research group for heart and brain imaging.

  9. High-Tc superconductivity at the interface between the CaCuO2 and SrTiO3 insulating oxides

    DOE PAGESBeta

    Di Castro, D.; Cantoni, C.; Ridolfi, F.; Aruta, C.; Tebano, A.; Yang, N.; Balestrino, G.

    2015-09-28

    At interfaces between complex oxides it is possible to generate electronic systems with unusual electronic properties, which are not present in the isolated oxides. One important example is the appearance of superconductivity at the interface between insulating oxides, although, until now, with very low Tc. We report the occurrence of high Tc superconductivity in the bilayer CaCuO2/SrTiO3, where both the constituent oxides are insulating. In order to obtain a superconducting state, the CaCuO2/SrTiO3 interface must be realized between the Ca plane of CaCuO2 and the TiO2 plane of SrTiO3. Only in this case can oxygen ions be incorporated in themore »interface Ca plane, acting as apical oxygen for Cu and providing holes to the CuO2 planes. In addition, a detailed hole doping spatial profile can be obtained by scanning transmission electron microscopy and electron-energy-loss spectroscopy at the O K edge, clearly showing that the (super)conductivity is confined to about 1–2 CaCuO2 unit cells close to the interface with SrTiO3. The results obtained for the CaCuO2/SrTiO3 interface can be extended to multilayered high Tc cuprates, contributing to explaining the dependence of Tc on the number of CuO2 planes in these systems.« less

  10. 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

  11. High-Tc Superconductivity at the Interface between the CaCuO2 and SrTiO3 Insulating Oxides

    NASA Astrophysics Data System (ADS)

    Di Castro, D.; Cantoni, C.; Ridolfi, F.; Aruta, C.; Tebano, A.; Yang, N.; Balestrino, G.

    2015-10-01

    At interfaces between complex oxides it is possible to generate electronic systems with unusual electronic properties, which are not present in the isolated oxides. One important example is the appearance of superconductivity at the interface between insulating oxides, although, until now, with very low Tc . We report the occurrence of high Tc superconductivity in the bilayer CaCuO2/SrTiO3 , where both the constituent oxides are insulating. In order to obtain a superconducting state, the CaCuO2/SrTiO3 interface must be realized between the Ca plane of CaCuO2 and the TiO2 plane of SrTiO3 . Only in this case can oxygen ions be incorporated in the interface Ca plane, acting as apical oxygen for Cu and providing holes to the CuO2 planes. A detailed hole doping spatial profile can be obtained by scanning transmission electron microscopy and electron-energy-loss spectroscopy at the O K edge, clearly showing that the (super)conductivity is confined to about 1-2 CaCuO2 unit cells close to the interface with SrTiO3 . The results obtained for the CaCuO2/SrTiO3 interface can be extended to multilayered high Tc cuprates, contributing to explaining the dependence of Tc on the number of CuO2 planes in these systems.

  12. Reduction of Tc(VII) by Fe(II) Sorbed on Al (hydr)oxides

    SciTech Connect

    Peretyazhko, Tetyana; Zachara, John M.; Heald, Steve M.; Kukkadapu, Ravi K.; Liu, Chongxuan; Plymale, Andrew E.; Resch, Charles T.

    2008-08-01

    Technetium speciation, solubility and sorption behavior is strongly dependent on its valence state. Under oxic conditions, Tc exists as the soluble, weakly-sorbing pertechnetate [TcO4-] anion. The reduced form of technetium, Tc(IV), is stable in anoxic environments and is sparingly soluble as TcO2·xH2O(s). Here we investigate the heterogeneous reduction of Tc(VII) by Fe(II) sorbed on Al (hydr)oxides [diaspore (?-AlOOH) and corundum (?-Al2O3)]. Experiments were performed to study the kinetics of Tc(VII) reduction, examine changes in Fe surface speciation during Tc(VII) reduction (Mössbauer spectroscopy), and identify the nature of Tc(IV)-containing reaction products (X-ray absorption spectroscopy). We found that Tc(VII) was completely reduced by adsorbed Fe(II) within 11d (diaspore suspension) and 4d (corundum suspension). Mössbauer measurements revealed that the Fe(II) signal became less intense with Tc(VII) reduction, and was accompanied by increase in Fe(III) doublet and magnetically-ordered Fe(III) sextet signals, with latter parameters close to those for hematite. Formation of magnetically ordered Fe(III) did not depend on the oxidant nature, as both Tc(VII) or O2 lead to the formation of a virtually identical hematite-like phase. The Fe(II) doublet displayed no differences in Mössbauer parameters before and after Tc(VII) reduction, likely due to Fe(II) adsorption to similar sites and no Fe(II) sorption to or precipitation within solid phases formed. Tc-EXAFS spectroscopy revealed that the final heterogeneous redox product on corundum was similar to Tc(IV) oxyhydroxide, TcO2?xH2O. The formation of precursor polymeric TcnOy (4n-2y)+ chains prior to TcO2?xH2O precipitation might explain the formation of the separate TcO2-like phase on corundum without coprecipitated Fe.

  13. 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.

  14. Rotational dynamics of passive high Tc superconducting bearings

    NASA Astrophysics Data System (ADS)

    Weeks, David E.

    1991-08-01

    The rotational dynamics of passive high Tc superconducting bearings are discussed. Rotor deceleration as a function of time is measured using a bare rotor, a rotor with paddles, and a rotor with a small magnetic chip used to induce magnetic asymmetry. All three cases are fit to within experimental error using solutions to a first order differential equation where the decelerating torque is given by a constant term described by the critical-state Bean model, plus a term linear in the rotational frequency described by the Stokes ``slow flow'' approximation to the Navier-Stokes equations in the limit of small Reynolds number.

  15. TC-Investigator: A Matlab Program to Explore Pseudosections

    NASA Astrophysics Data System (ADS)

    Pearce, Mark; Gazley, Michael; White, Alistair

    2014-05-01

    Forward modelling of bulk rock compositions to constrain pressures and temperatures of metamorphism based on mineral assemblage is a commonly used technique. The pseudosections produced contain a wealth of information about predicted mineral compositions and abundances that goes far beyond variations in mineral assemblage. A grid of these variations can be contoured using Gibbs free energy minimisation software (such as Theriak-Domino) or precise isopleths calculated for specific quantities in THERMOCALC. We have produced a new piece of software called TC-Investigator that amalgamates these approaches to provide a relatively quick and user friendly way to contour all compositional parameters and mineral modes across a THERMOCALC pseudosection. TC-Investigator takes the postscript pseudosection diagram and creates a grid of points at a user-specified resolution. THERMOCALC is then used to calculate the equilibrium mineral assemblage at each point using an initial starting guess provided by the user (this can be calculated during initial pseudosection calculation). Once all points have been tried, any that failed to calculate are re-tried using interpolated starting guess values from the surrounding points. This procedure is iterated until no more solutions are found. Any remaining unsolved points are then interpolated numerically from surrounding solutions to produce a fully quantified set of mineral modes and compositions. Following calculation, the dataset can be contoured and output as figures, output as a Matlab readable binary structure or selected compositions written to an ASCII text file. Compositional maps created by TC-Investigator have the power to inform the user about compositional variables that are not conventionally considered. The automated calculation method makes it easy to investigate all variables in one go. For example, in metapelitic rocks, garnet shows the variations in composition that are usually contoured, however, these couple to variations in composition within many other minerals all of which can be seen using TC-Investigator. Plots of water content reveal zones in P-T space where there is extremely rapid water production as hydrous minerals breakdown. As new P-T conditions and bulk compositions are explored using improved thermodynamic datasets this software will provide a quick and simple way to identify key compositional and modal variations in the newly modelled mineral systems.

  16. 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.

  17. 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.

  18. A torsion balance to measure hysteretic levitation forces in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Weeks, David E.

    1990-01-01

    A simple torsion balance is described which is used to measure the levitation force on a magnet as a function of height above bulk samples of new high-Tc superconductors. Results are presented for the YBa2Cu3O(x) (Tc about 90 K) and the Tl-Ba-Ca-Cu-O (Tc about 120 K) superconducting systems. Possible uses for the balance are discussed.

  19. Preparation of (99m)Tc labeled vitamin C (ascorbic acid) and biodistribution in rats.

    PubMed

    Yigit, Ugur Sezai; Lambrecht, Fatma Yurt; Unak, Perihan; Biber, Fazilet Zümrüt; Medine, Emin Ilker; Cetinkaya, Berkan

    2006-01-01

    The aim of this study was to label ascorbic acid with (99m)Tc and to investigate its radiopharmaceutical potential in rats. Ascorbic acid was labeled with (99m)Tc using the stannous chloride method. The radiochemical purity of [(99m)Tc]ascorbic acid ((99m)Tc-AA) was determined by RTLC, paper electrophoresis, and RHPLC methods. The labeling yield was found to be 93+/-5.0%. The maximum labeling yield of (99m)Tc-AA was determined at pH 5 and 25 degrees C. The biodistribution studies related to (99m)Tc-AA were done in male albino Wistar rats. (99m)Tc-AA, which has a specific activity of 13.02 GBq/mmol, was administered into the tail vein of the rats. The rats were sacrificed at 15, 30, 60, and 120 min after the injection by heart puncture under ether anaesthesia. The organs were weighed after removal. Their activities were counted using a Cd(Te) detector equipped with a RAD 501 count system. The %ID/g (% of injected dose per gram of tissue weight) in each organ and in blood was calculated. Maximum uptake of (99m)Tc-AA was observed in prostate and kidneys at the 60th min. (99m)Tc-AA may be a promising radiopharmaceutical for the imaging of prostate and kidneys. PMID:16394539

  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. )

    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. Pentachlorooxotechnetate(VI) anion, (TcOCl/sub 5/): an EPR study

    SciTech Connect

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

    1985-07-03

    The anion pentachlorooxotechnetate(VI), TcOCl/sub 5//sup -/, has been prepared by reduction of TcO/sub 4//sup -/ with HCl in concentrated H/sub 2/SO/sub 4/ and investigated by means of the EPR technique. The axial symmetric spectrum suggests an in-plane ..pi..-type ground state of the MO of the unpaired electron. The Tc-Cl/sub eq/ bonding properties have been discussed in terms of MO theory, and a comparison has been given to the bonding properties in likely complexes of neighboring elements of Tc.

  2. 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.

  3. Origin of nonmonotonic Tc behavior in ferromagnet/superconductor structures

    NASA Astrophysics Data System (ADS)

    Khusainov, Mansur; Izyumov, Yurii A.; Proshin, Yurii N.

    2000-07-01

    The original theory of proximity effect in the layered ferromagnetic metal/superconductor (FM/S) structures taking into account a finite transparency of FM/S interface as well as a competition between 1D and 3D Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) states is developed. It is shown that the oscillatory dependence of critical temperature Tc on the FM layer thickness df is due to oscillations of the Cooper pairs flux at the FM/S boundary. This effect is possible not only in the FM/S multilayers, but in the FM/S bilayers as well. The phenomena of reentrant and periodically reentrant superconductivity in the FM/S bilayers and superlattices are predicted. The competition between 1D and 3D LOFF states leads to significant smoothing of the Tc( df) dependence, so that in the most cases one maximum of this dependence is realized as this has been observed in Gd/Nb and Fe/Nb/Fe.

  4. Structural investigations of recently discovered high Tc superconductors.

    PubMed

    van Tendeloo, G; Krekels, T; Amelinckx, S; Babu, T G; Greaves, C; Hervieu, M; Michel, C; Raveau, B

    1995-02-01

    A short overview is given of the possibilities of electron microscopy in the determination of the local, atomic scale structure of high Tc superconducting materials. Examples include the detection of weak oxygen ordering, description and characterization of deformation modulations in layered superconductors, and analysis of very long period superstructures. The ordering principles for tetrahedral chains in Ga-, Co-, or Al-substituted YBCO are discussed and their complex defect structures are described. The incommensurate modulation in YBCO-based materials containing SO4-tetrahedra, centered on the Cu(1) sites of the CuO-chain plane, is attributed to the ordering of b-oriented SO4-rich chains in the Cu(1)-S-O layer; the structure is described in terms of an SO4-concentration wave. As examples of the new mercury-based superconducting family we discuss Y0.6Ca0.4Ba2Hg1-xMxCu2O6+y, which crystallizes in the space group P4/mmm with a = 0.3870(1) nm, c = 1.2537(1) nm. This cuprate belongs to the 1212 series; susceptibility measurements show a Tc (onset) of 90K, with a diamagnetic volume fraction of 27% at 4.2K to be reached. A second example is related to the compound Tl2HgBa4Cu2O10+y, in which ordering between single Hg layers and double Tl layers is observed. PMID:7711324

  5. Power Systems Development Facility Gasification Test Run TC11

    SciTech Connect

    Southern Company Services

    2003-04-30

    This report discusses Test Campaign TC11 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). Test run TC11 began on April 7, 2003, with startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until April 18, 2003, when a gasifier upset forced the termination of the test run. Over the course of the entire test run, gasifier temperatures varied between 1,650 and 1,800 F at pressures from 160 to 200 psig during air-blown operations and around 135 psig during enriched-air operations. Due to a restriction in the oxygen-fed lower mixing zone (LMZ), the majority of the test run featured air-blown operations.

  6. 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.

  7. Nuclear shape and structure in neutron-rich 110,111Tc

    SciTech Connect

    Luo, Y.X.; Hamilton, J.H.; Rasmussen, J.O.; Ramayya, A.V.; Stefanescu, I.; Hwang, J.K.; Zhu, S.J.; Gore, P.M.; Jones, E.F.; Fong,D.; Wu, S.C.; Lee, I.Y.; Ginter, T.N.; Ter-Akopian, G.M.; Daniel, A.V.; Stoyer, M.A.; Donangelo, R.; Gelberg, A.

    2006-02-02

    The structure of Tc nuclei is extended to the moreneutron-rich regions based on measurements of prompt gamma rays from thespontaneous fission of 252Cf at Gammasphere. The level scheme of N=67neutron-rich (Z=43) 110Tc is established for the first time and that of111Tc is expanded. The ground-state band of 111Tc reaches theband-crossing region and the new observation of the weakly populatedalpha = -1/2 member of the band provides important information ofsignature splitting. The systematics of band crossings in the isotopicand isotonic chains and a CSM calculation suggest that the band crossingof the gs band of 111Tc is due to alignment of a pair of h11/2 neutrons.The best fit to signature splitting, branching ratios, and excitations ofthe ground-state band of 111Tc by RTRP model calculations result in ashape of epsilon2 = 0.32 and gamma = -26 deg. for this nucleus. Itstriaxiality is larger than that of 107Tc, to indicate increasingtriaxiality with increasing neutron number. The identification of theweakly-populated "K+2 satellite" band provides strong evidence for thelarge triaxiality of 111Tc. In 110Tc the four lowest-lying levelsobserved are very similar to those in 108Tc. At an excitation of 478.9keV above the lowest state observed, ten states of a delta I = 1 band areobserved. This band is very analogous to the delta I = 1 bands in106,108Tc, but it has greater signature splitting at higherspins.

  8. 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.

    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.

  9. 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.

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

    PubMed

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

    2011-03-01

    The isotope (99)Tc (?(max), 293.7; half-life, 2.1 × 10(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 (99)Tc is important in identifying tunable strategies to separate (99)Tc from spent fuel and from waste tanks and, once separated, to identify and develop an appropriately stable waste form for (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 (99)Tc. In this study, (99)Tc complexes of the (?(2)-P(2)W(17)O(61))(10-) and (?(1)-P(2)W(17)O(61))(10-) isomers were prepared. Ethylene glycol was used as a "transfer ligand" to minimize the formation of TcO(2)·xH(2)O. The solution structures, formulations, and purity of Tc(V)O(?(1)/?(2)-P(2)W(17)O(61))(7-) were determined by multinuclear NMR. X-ray absorption spectroscopy of the complexes is in agreement with the formulation and structures determined from (31)P and (183)W NMR. Preliminary electrochemistry results are consistent with the EXAFS results, showing a facile reduction of the Tc(V)O(?(1)-P(2)W(17)O(61))(7-) species compared to the Tc(V)O(?(2)-P(2)W(17)O(61))(7-) analog. The ?(1) defect is unique in that a basic oxygen atom is positioned toward the ?(1) site, and the Tc(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 Re(V) analogs are about 200 mV more difficult to reduce in accordance with periodic trends. PMID:21268605

  11. TcCYPR04, a Cacao Papain-Like Cysteine-Protease Detected in Senescent and Necrotic Tissues Interacts with a Cystatin TcCYS4

    PubMed Central

    Cardoso, Thyago Hermylly Santana; Freitas, Ana Camila Oliveira; Andrade, Bruno Silva; de Sousa, Aurizangela Oliveira; Santiago, André da Silva; Koop, Daniela Martins; Gramacho, Karina Peres; Alvim, Fátima Cerqueira; Micheli, Fabienne; Pirovani, Carlos Priminho

    2015-01-01

    The interaction amongst papain-like cysteine-proteases (PLCP) and their substrates and inhibitors, such as cystatins, can be perceived as part of the molecular battlefield in plant-pathogen interaction. In cacao, four cystatins were identified and characterized by our group. We identified 448 proteases in cacao genome, whereof 134 were cysteine-proteases. We expressed in Escherichia coli a PLCP from cacao, named TcCYSPR04. Immunoblottings with anti-TcCYSPR04 exhibited protein increases during leaf development. Additional isoforms of TcCYSPR04 appeared in senescent leaves and cacao tissues infected by Moniliophthora perniciosa during the transition from the biotrophic to the saprophytic phase. TcCYSPR04 was induced in the apoplastic fluid of Catongo and TSH1188 cacao genotypes, susceptible and resistant to M. perniciosa, respectively, but greater intensity and additional isoforms were observed in TSH1188. The fungal protein MpNEP induced PLCP isoform expression in tobacco leaves, according to the cross reaction with anti-TcCYSPR04. Several protein isoforms were detected at 72 hours after treatment with MpNEP. We captured an active PLCP from cacao tissues, using a recombinant cacao cystatin immobilized in CNBr-Sepharose. Mass spectrometry showed that this protein corresponds to TcCYSPR04. A homology modeling was obtained for both proteins. In order to become active, TcCYSPR04 needs to lose its inhibitory domain. Molecular docking showed the physical-chemical complementarities of the interaction between the cacao enzyme and its inhibitor. We propose that TcCYSPR04 and its interactions with cacao cystatins are involved in the senescence and necrosis events related to witches’ broom symptoms. This molecular interaction may be the target for future interventions to control witches' broom disease. PMID:26641247

  12. Reductive sequestration of pertechnetate (??TcO??) by nano zerovalent iron (nZVI) transformed by abiotic sulfide.

    PubMed

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

    2013-05-21

    Under anoxic conditions, soluble pertechnetate (??TcO??) can be reduced to less soluble TcO?·nH?O, 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 zerovalent iron (nZVI). nZVI was pre-exposed to increasing concentrations of sulfide in simulated Hanford groundwater for 24 h to mimic the onset of aquifer biotic sulfate reduction. 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 0 and 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 TcO?? for FeS than 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, the pathway for Tc(IV) formation shifted from TcO?·nH2? to Tc sulfide phases. The most substantial change of Tc speciation occurred at low S/Fe, coinciding with the rapid increase in Tc removal rate. This agreement further confirms the importance of FeS in Tc sequestration. PMID:23611018

  13. The Heavy Quark Free-Energy at T<Tc in AdS/QCD

    E-print Network

    K. Veshgini; E. Megias; J. Nian; H. J. Pirner

    2009-11-09

    Starting with the modified AdS/QCD metric developed in Ref.[1] we use the Nambu-Goto action to obtain the free energy of a quark-antiquark pair at T<Tc, for which we show that the effective string tension goes to zero at Tc=154MeV.

  14. 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

  15. Preparation of (99m)tc-clomiphene citrate as a novel agent for breast cancer imaging.

    PubMed

    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 (99m)Tc-labelled derivative based on triphenylethylene for breast cancer imaging. (99m)Tc-Clomiphene was obtained with a radiochemical yield of 94.4% by adding (99m)Tc to 1.5?mg Clomiphene citrate in the presence of 10??g SnCl(2) at pH 7. The optimization of the labeling yield of Clomiphene citrate, with (99m)Tc, 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 (99m)Tc-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 (99m)Tc-Clomiphene complex was found to be 5.5 ± 0.4 which was higher than that of the commercially available (99m)Tc-MIBI. This data revealed the localization of tracer in tumor tissue with high percent sufficient to use (99m)Tc-Clomiphene as a promising tool for the diagnosis of breast cancer. PMID:23213567

  16. (99)Tc(VII) Retardation, Reduction, and Redox Rate Scaling in Naturally Reduced Sediments.

    PubMed

    Liu, Yuanyuan; Liu, Chongxuan; Kukkadapu, Ravi K; McKinley, James P; Zachara, John; Plymale, Andrew E; Miller, Micah D; Varga, Tamas; Resch, Charles T

    2015-11-17

    An experimental and modeling study was conducted to investigate pertechnetate (Tc(VII)O4(-)) retardation, reduction, and rate scaling in three sediments from Ringold formation at U.S. Department of Energy's Hanford site, where (99)Tc is a major contaminant in groundwater. Tc(VII) was reduced in all the sediments in both batch reactors and diffusion columns, with a faster rate in a sediment containing a higher concentration of HCl-extractable Fe(II). Tc(VII) migration in the diffusion columns was reductively retarded with retardation degrees correlated with Tc(VII) reduction rates. The reduction rates were faster in the diffusion columns than those in the batch reactors, apparently influenced by the spatial distribution of redox-reactive minerals along transport paths that supplied Tc(VII). X-ray computed tomography and autoradiography were performed to identify the spatial locations of Tc(VII) reduction and transport paths in the sediments, and results generally confirmed the newly found behavior of reaction rate changes from batch to column. The results from this study implied that Tc(VII) migration can be reductively retarded at Hanford site with a retardation degree dependent on reactive Fe(II) content and its distribution in sediments. This study also demonstrated that an effective reaction rate may be faster in transport systems than that in well-mixed reactors. PMID:26469942

  17. Imaging endocarditis with Tc-99m-labeled antibody--an experimental study: concise communication

    SciTech Connect

    Wong, D.W.; Dhawan, V.K.; Tanaka, T.; Mishkin, F.S.; Reese, I.C.; Thadepalli, H.

    1982-03-01

    The sensitivity and specificity of Tc-99m-labeled antibacterial antibody (Tc-99m Ab) for detecting bacterial endocarditis were evaluated in an experimental model. Rabbit-produced antistaphylococcal antibody was extracted using Rivanol and chemically labeled with Tc-99m. This Tc-99m Ab was injected intravenously in New Zealand rabbits 24 hr after producing Staphylococcus aureus endocarditis of the aortic valve. Imaging and tissue analyses were performed on the following day. All 11 animals developed S. aureus aortic-valve vegetations and showed increased uptake of Tc-99m Ab at the aortic valve, 118 times higher than at the uninfected tricuspid valve. Although high hepatic radioactivity and anatomic uncertainties interfered with in vivo delineation of these lesions, images of the excised hearts showed all affected valves. Two rabbits inoculated with Escherichia coli did not develop endocarditis and had little uptake of Tc-99m Ab, while six rabbits with enterococcal endocarditis had no uptake of the Tc-99m Ab in their vegetations. The findings suggest potential value of Tc-99m Ab on the rapid diagnosis of endocarditis.

  18. Quantized massive collective modes and massive spin fluctuations in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Kanazawa, I.; Sasaki, T.

    2015-10-01

    We have analyzed angle-resolved photoemission spectra of the single- and double-layered Bi-family high-Tc superconductors by using quantized massive gauge fields, which might contain effects of spin fluctuations, charge fluctuations, and phonons. It is suggested strongly that the quantized massive gauge fields might be mediating Cooper pairing in high-Tc cuprates.

  19. Diophantine Generation,

    E-print Network

    Shlapentokh, Alexandra

    Diophantine Generation, Horizontal and Vertical Problems, and the Weak Vertical Method Alexandra Shlapentokh Diophantine Sets, Definitions and Generation Diophantine Sets Diophantine Generation Properties of Diophantine Generation Diophantine Family of Z Diophantine Family of a Polynomial Ring Going Down Horizontal

  20. 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.

  1. Spectral properties of rf emission from high Tc films

    SciTech Connect

    Jung, G.; Konopka, J.; Vitale, S. )

    1990-09-15

    Spectral properties of rf radiation from intrinsic Josephson junctions in high {Tc} Y-Ba-Cu-O thin film have been measured in the frequency range up to 1.5 GHz. Narrow emission lines with the 3 dB bandwidth of the order of 20 MHz were detected indicating that Josephson clusters radiate coherently. Synchronization conditions are determined by dc current and external magnetic field bias. Frequency locking of radiation to external resonant circuit was also observed. Spectral line narrowing due to resonant lock was distinguished from the coherence-induced narrowing by different tuning properties of the emission line. Noncoherent Josephson radiation manifests itself as a broadband background noise increase. A pronounced 1/{ital f}-like tail sensitive to dc bias and magnetic field was observed in a low frequency part of the spectrum.

  2. 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.

  3. Doping dependence of fluctuation diamganetism in High Tc superconductors

    NASA Astrophysics Data System (ADS)

    Mukerjee, Subroto; Sarkar, Kingshuk; Banerjee, Sumilan; Ramakrishnan, T. V.

    2015-03-01

    Using a recently proposed Ginzburg-Landau-like energy functional due to, we calculate the fluctuation diamagnetism of high-Tc su- perconductors as a function of doping x in addition to the magnetic field H and temperature T by employing classical Monte-Carlo simulations. We explicitly show that the doping dependence of our diamagnetism results are in good qualitative agreement and reasonable quantitative agreement with experimental data. Our calculations show that a model where the pairing scale increases and superfluid density decreases with underdoping produces features of the observed magnetization in the pseudogap region. In particular we show that the magnetization tracks the superconducting dome instead of the pseudogap temperature as seen in experiment and also comment on the determination of doping dependence of the upper-critical field.

  4. High-{Tc} superconducting antenna-coupled microbolometer on silicon

    SciTech Connect

    Rice, J.P.; Grossman, E.N.; Borcherdt, L.J.; Rudman, D.A.

    1994-12-31

    A process is described for fabricating antenna-coupled resistive-edge microbolometers based on the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) on silicon. The YBCO and a buffer layer of yttria-stabilized zirconia (YSZ) were grown epitaxially on silicon to minimize excess electrical noise. A silicon-micromachined YBCO/YSZ air-bridge was incorporated to minimize the thermal conductance and the heat capacity. The thermal conductance of the air-bridge was measured to be 3 {times} 10{sup {minus}6} W/K at a temperature of 100 K. At an operating temperature of 89 K, the detector is estimated to have a response time of 2 {micro}s, a responsivity in the 1,000 V/W range, and a noise-equivalent power (NEP) in the 10{sup {minus}12} W/Hz{sup 1/2} range at 1,000 Hz.

  5. GM=tc^3 in The Year of Light

    NASA Astrophysics Data System (ADS)

    Riofrio, Louise

    2015-08-01

    2015 is the International Year of Light. With the lack of evidence for primordial gravitational waves, light is an alternative to the darkness of untestable ideas. We may test a hypothesis GM=tc^3, where G is Newton's constant and M, t represent mass and age in the universe. This provides a precise fit to redshifts of Type Ia supernovae and explains the "Faint Young Sun" paradox of astrophysics. A 12-sigma anomaly in laser measurements of lunar orbital evolution can be predicted to 1/10 of a standard deviation, a precise test of theory. Starting in 2016, the Atomic Clock Ensemble in Space (ACES) aboard the International Space Station will search for anisotropies in the speed of light. Growing evidence may indicate a "c change" in physics.

  6. Collective band structures in neutron-rich {sup 106,107}Tc

    SciTech Connect

    Gu, L.; Wang, J. G.; Che, X. L.; Ding, H. B.; Xu, Q.; Yang, Y. Y.; Zhu, S. J.; Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Liu, S. H.; Li, K.; Luo, Y. X.; Rasmussen, J. O.; Lee, I. Y.; Ma, W. C.

    2009-05-15

    The high spin states of neutron-rich {sup 106,107}Tc nuclei have been reinvestigated by observing prompt {gamma} rays from the spontaneous fission of {sup 252}Cf. In {sup 106}Tc, a previously known collective band is expanded, and a new collective band is identified. In {sup 107}Tc, a collective band based on the {pi}5/2{sup -}[303] orbital is confirmed and extended. Inconsistencies in the configuration assignments for positive parity bands in {sup 105,107}Tc in the previous reports are clarified. The spins and parities as well as the configurations for the two bands in {sup 106}Tc are assigned according to the angular momentum alignments and g-factor calculations. Other characteristics for the observed bands are discussed.

  7. Passport, a native Tc1 transposon from flatfish, is functionally active in vertebrate cells

    PubMed Central

    Clark, Karl J.; Carlson, Daniel F.; Leaver, Michael J.; Foster, Linda K.; Fahrenkrug, Scott C.

    2009-01-01

    The Tc1/mariner family of DNA transposons is widespread across fungal, plant and animal kingdoms, and thought to contribute to the evolution of their host genomes. To date, an active Tc1 transposon has not been identified within the native genome of a vertebrate. We demonstrate that Passport, a native transposon isolated from a fish (Pleuronectes platessa), is active in a variety of vertebrate cells. In transposition assays, we found that the Passport transposon system improved stable cellular transgenesis by 40-fold, has an apparent preference for insertion into genes, and is subject to overproduction inhibition like other Tc1 elements. Passport represents the first vertebrate Tc1 element described as both natively intact and functionally active, and given its restricted phylogenetic distribution, may be contemporaneously active. The Passport transposon system thus complements the available genetic tools for the manipulation of vertebrate genomes, and may provide a unique system for studying the infiltration of vertebrate genomes by Tc1 elements. PMID:19136468

  8. Temperature evolution of correlation strength in the superconducting state of high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Kudo, S.; Yoshida, T.; Ideta, S.; Takashima, K.; Anzai, H.; Fujita, T.; Nakashima, Y.; Ino, A.; Arita, M.; Namatame, H.; Taniguchi, M.; Kojima, K. M.; Uchida, S.; Fujimori, A.

    2015-11-01

    We have performed an angle-resolved photoemission study of the nodal quasiparticle spectra of the high-Tc cuprate trilayer Bi2Sr2Ca2Cu3O10 +? (Tc˜110 K). The spectral weight Z of the nodal quasiparticle increases with decreasing temperature across Tc. Such a temperature dependence is qualitatively similar to that of the coherence peak intensity in the antinodal region of various high-Tc cuprates, although the nodal spectral weight remains finite and large above Tc. We attribute this observation to the reduction of electron correlation strength in going from the normal metallic state to the superconducting state, a characteristic behavior of a superconductor with strong electron correlation.

  9. Dynamics of an Ising ferromagnet at T<= Tc from the droplet model approach

    NASA Astrophysics Data System (ADS)

    Shneidman, Vitaly A.

    1992-11-01

    We consider a Fokker-Planck type kinetic equation for the cluster distribution, similar to the one used in nucleation theory. From the asymptotic solution of this equation at T < Tc we show that transition to equilibrium takes place through propagation of a “shock-wave” in the space of cluster sizes. This leads to a stretched-exponential magnetization time-dependence. At T = Tc an exact solution to the kinetic equation is derived. The results are compared to simulation data by Stauffer and Kertesz for cluster population in a 2D Ising ferromagnet driven by Glauber dynamics. While for T < Tc analytic and computer results correspond to each other with very few matching parameters, at T = Tc a strong deviation is observed which could mean the necessity of generalization of the kinetic equation. Inherent limitations of the droplet model which may be important even below Tc are also discussed.

  10. Multiple myeloma showing increased accumulation of Tc-99m hexamethylpropylene amine oxime on brain SPECT.

    PubMed

    Takeshita, T; Kaminaga, T; Kikuchi, Y; Furui, S

    2000-06-01

    The authors report a case of multiple myeloma with increased accumulation of Tc-99m hexamethylpropylene amine oxime (HMPAO) on brain SPECT. Tc-99m HMPAO is a lipophilic compound that freely passes through the intact blood-brain barrier and cell membrane and is rapidly converted to a hydrophilic form by glutathione and then retained in the neuron for several hours. In general, Tc-99m HMPAO shows decreased accumulation in brain tumors. However, some reports of increased accumulation in brain tumors, such as meningioma, glioblastoma multiforme, high-grade astrocytoma, pituitary adenoma, and multiple myeloma, have been published. The Tc-99m HMPAO uptake in these tumors has been attributed to tumor blood flow or glutathione contents within the tumor. With regard to uptake to Tc-99m HMPAO in multiple myeloma, the tumor size is considered to be an additional factor. PMID:10836712

  11. The uptake of TcO-4 by plants: A mathematical description

    SciTech Connect

    Van Loon, L.R.; Desmet, G.M.; Cremers, A. )

    1989-08-01

    A model describing the uptake of TcO-4 by spinach plants was developed. The equation relates both plant and soil parameters (e.g., growth, metabolism, concentration of TcO-4 and composition of the growth medium) to the concentration of Tc in the shoot of the plant. As the soil solution is the medium from which plants obtain nutrients and non-nutrients, the modeling parameters have been obtained from uptake experiments using nutrient solutions (= simulated soil solutions) as the growth medium. Two important model assumptions are: (1) that an equilibrium exists between TcO-4 in the plant and the growth medium and (2) that the leaf TcO-4 metabolism is a pseudofirst order reaction occurring in a non-constant volume.

  12. Submillimeter residual losses in high-{Tc} superconductors

    SciTech Connect

    Miller, D.

    1993-09-01

    Bolometry was used obtain accurate submillimeter residual loss data for epitaxial films of YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO), Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10}, Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8} (TCBCO), and Ba{sub 0.6}K{sub 0.4}BiO{sub 3} (BKBO). We were able to fit the absorptivity measured for Nb films to an Eliashberg strong coupling calculation; excellent agreement resulted between parameters from best fits and measured Residual Resistivity Ratio. Microwave surface resistance measurements made on the same YBCO and TCBCO films are in excellent agreement with submillimeter measurements. Absorptivities for all YBCO films studied are qualitatively similar, increasing smoothly with frequency, with no gap-like features below the well known absorption edge at 450 cm{sup {minus}1}. Losses in YBCO films were fit to a weakly coupled grain model for the a-b plane conductivity. Strong phonon structure was observed in TCBCO films between 60 and 700 cm{sup {minus}1} (2 THz and 23 THz); these losses could not be fitted to the simple weakly coupled grain model, in contrast to the case for other high-{Tc} superconductors where phonon structure observed in ceramics are is absent in epitaxial oriented films and crystals because of electronic screening due to high conductivity of a-b planes. Absorptivity data for the BKBO films all show a strong absorption onset near the BCS tunneling gap of 3.5 k{sub B}{Tc}. Comparison with strong coupling Eliashberg predictions and of a Kramers-Kronig analysis indicate that the absorption onset is consistent with a superconducting energy gap. Effects of magnetic field on residual losses in YBCO films show a resonant absorption feature in vicinity of predicted

  13. 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.

    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.

  14. Noninvasive imaging of radiolabeled exosome-mimetic nanovesicle using (99m)Tc-HMPAO.

    PubMed

    Hwang, Do Won; Choi, Hongyoon; Jang, Su Chul; Yoo, Min Young; Park, Ji Yong; Choi, Na Eun; Oh, Hyun Jeong; Ha, Seunggyun; Lee, Yun-Sang; Jeong, Jae Min; Gho, Yong Song; Lee, Dong Soo

    2015-01-01

    Exosomes known as nano-sized extracellular vesicles attracted recent interests due to their potential usefulness in drug delivery. Amid remarkable advances in biomedical applications of exosomes, it is crucial to understand in vivo distribution and behavior of exosomes. Here, we developed a simple method for radiolabeling of macrophage-derived exosome-mimetic nanovesicles (ENVs) with (99m)Tc-HMPAO under physiologic conditions and monitored in vivo distribution of (99m)Tc-HMPAO-ENVs using SPECT/CT in living mice. ENVs were produced from the mouse RAW264.7 macrophage cell line and labeled with (99m)Tc-HMPAO for 1?hr incubation, followed by removal of free (99m)Tc-HMPAO. SPECT/CT images were serially acquired after intravenous injection to BALB/c mouse. When ENVs were labeled with (99m)Tc-HMPAO, the radiochemical purity of (99m)Tc-HMPAO-ENVs was higher than 90% and the expression of exosome specific protein (CD63) did not change in (99m)Tc-HMPAO-ENVs. (99m)Tc-HMPAO-ENVs showed high serum stability (90%) which was similar to that in phosphate buffered saline until 5?hr. SPECT/CT images of the mice injected with (99m)Tc-HMPAO-ENVs exhibited higher uptake in liver and no uptake in brain, whereas mice injected with (99m)Tc-HMPAO showed high brain uptake until 5?hr. Our noninvasive imaging of radiolabeled-ENVs promises better understanding of the in vivo behavior of exosomes for upcoming biomedical application. PMID:26497063

  15. Noninvasive imaging of radiolabeled exosome-mimetic nanovesicle using 99mTc-HMPAO

    PubMed Central

    Hwang, Do Won; Choi, Hongyoon; Jang, Su Chul; Yoo, Min Young; Park, Ji Yong; Choi, Na Eun; Oh, Hyun Jeong; Ha, Seunggyun; Lee, Yun-Sang; Jeong, Jae Min; Gho, Yong Song; Lee, Dong Soo

    2015-01-01

    Exosomes known as nano-sized extracellular vesicles attracted recent interests due to their potential usefulness in drug delivery. Amid remarkable advances in biomedical applications of exosomes, it is crucial to understand in vivo distribution and behavior of exosomes. Here, we developed a simple method for radiolabeling of macrophage-derived exosome-mimetic nanovesicles (ENVs) with 99mTc-HMPAO under physiologic conditions and monitored in vivo distribution of 99mTc-HMPAO-ENVs using SPECT/CT in living mice. ENVs were produced from the mouse RAW264.7 macrophage cell line and labeled with 99mTc-HMPAO for 1?hr incubation, followed by removal of free 99mTc-HMPAO. SPECT/CT images were serially acquired after intravenous injection to BALB/c mouse. When ENVs were labeled with 99mTc-HMPAO, the radiochemical purity of 99mTc-HMPAO-ENVs was higher than 90% and the expression of exosome specific protein (CD63) did not change in 99mTc-HMPAO-ENVs. 99mTc-HMPAO-ENVs showed high serum stability (90%) which was similar to that in phosphate buffered saline until 5?hr. SPECT/CT images of the mice injected with 99mTc-HMPAO-ENVs exhibited higher uptake in liver and no uptake in brain, whereas mice injected with 99mTc-HMPAO showed high brain uptake until 5?hr. Our noninvasive imaging of radiolabeled-ENVs promises better understanding of the in vivo behavior of exosomes for upcoming biomedical application. PMID:26497063

  16. Incorporation and retention of 99-Tc(IV) in magnetite under high pH conditions.

    PubMed

    Marshall, Timothy A; Morris, Katherine; Law, Gareth T W; Mosselmans, J Frederick W; Bots, Pieter; Parry, Stephen A; Shaw, Samuel

    2014-10-21

    Technetium incorporation into magnetite and its behavior during subsequent oxidation has been investigated at high pH to determine the technetium retention mechanism(s) on formation and oxidative perturbation of magnetite in systems relevant to radioactive waste disposal. Ferrihydrite was exposed to Tc(VII)(aq) containing cement leachates (pH 10.5-13.1), and crystallization of magnetite was induced via addition of Fe(II)aq. A combination of X-ray diffraction (XRD), chemical extraction, and X-ray absorption spectroscopy (XAS) techniques provided direct evidence that Tc(VII) was reduced and incorporated into the magnetite structure. Subsequent air oxidation of the magnetite particles for up to 152 days resulted in only limited remobilization of the incorporated Tc(IV). Analysis of both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data indicated that the Tc(IV) was predominantly incorporated into the magnetite octahedral site in all systems studied. On reoxidation in air, the incorporated Tc(IV) was recalcitrant to oxidative dissolution with less than 40% remobilization to solution despite significant oxidation of the magnetite to maghemite/goethite: All solid associated Tc remained as Tc(IV). The results of this study provide the first direct evidence for significant Tc(IV) incorporation into the magnetite structure and confirm that magnetite incorporated Tc(IV) is recalcitrant to oxidative dissolution. Immobilization of Tc(VII) by reduction and incorporation into magnetite at high pH and with significant stability upon reoxidation has clear and important implications for limiting technetium migration under conditions where magnetite is formed including in geological disposal of radioactive wastes. PMID:25236360

  17. Bioaccumulation and distribution of /sup 95m/Tc in an experimental freshwater pond

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.

    1981-01-01

    An acute release of /sup 95m/Tc was made to a small experimental freshwater pond to determine the behavior of technetium in a freshwater ecosystem. The objectives of the study were (1) to determine the distribution of /sup 95m/Tc in the components of the ecosystem and (2) to determine the concentration in freshwater biota. Prior to the release of /sup 95m/Tc, the pond was stocked with aquatic macrophytes, fish, and invertebrates. All components of the pond were sampled for a period of 37 d. Analyses of filtered and unfiltered water samples showed that /sup 95m/Tc did not sorb significantly to particulates suspended in the water but remained dissolved. Sediments accumulated /sup 95m/Tc slowly as the experiment progressed. In the biota, periphyton accumulated /sup 95m/Tc rapidly, reaching the highest concentration (3482 dpm/g dry wt) 4 h after the release and maintaining a relatively high concentration throughout the experiment. Fish and invertebrates accumulated /sup 95m/Tc gradually. Elimination studies and tissue analyses showed that a large percentage of the body burden was in the digestive system of all fish, suggesting that fish were accumulating /sup 95m/Tc through the food chain. Biological half-lives determined from elimination studies for carp (Cyprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 2.5, 4.3, and 21.3 d, respectively. Calculated concentration factors for the same species were 11 for carp, 75 for mosquito fish, and 121 for snails. The estimated size of the biomass components in the ecosystem in descending order were: periphyton, macrophytes, invertebrates, fish, and algae. Based on biomass estimates and concentrations of the /sup 95m/Tc in the aquatic biota, approximately 1% of the /sup 95m/Tc accumulated in the biota.

  18. 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.; Burch, W.M.; Dasaklis, C.; Mackey, D.W.J.

    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.

  19. Reverse discordant behavior and progressive filling of a cold nodule on Tc-99m pertechnetate thyroid imaging

    SciTech Connect

    Huot, D.; Ton-That, Q.T.; Le Bel, L.; Carrier, L.; Picard, M. )

    1990-01-01

    The authors report on a patient with reverse discordant behavior between Tc-99m pertechnetate and I-131 associated with progressive filling of a cold nodule on the Tc-99m pertechnetate thyroid scan. Possible mechanisms are discussed.

  20. Jasmonate-responsive expression of paclitaxel biosynthesis genes in Taxus cuspidata cultured cells is negatively regulated by the bHLH transcription factors TcJAMYC1, TcJAMYC2, and TcJAMYC4

    PubMed Central

    Lenka, Sangram K.; Nims, N. Ezekiel; Vongpaseuth, Kham; Boshar, Rosemary A.; Roberts, Susan C.; Walker, Elsbeth L.

    2015-01-01

    Taxus cell suspension culture is a sustainable technology for the industrial production of paclitaxel (Taxol®), a highly modified diterpene anti-cancer agent. The methyl jasmonate (MJ)-mediated paclitaxel biosynthetic pathway is not fully characterized, making metabolic engineering efforts difficult. Here, promoters of seven genes (TASY, T5?H, DBAT, DBBT, PAM, BAPT, and DBTNBT), encoding enzymes of the paclitaxel biosynthetic pathway were isolated and used to drive MJ-inducible expression of a GUS reporter construct in transiently transformed Taxus cells, showing that elicitation of paclitaxel production by MJ is regulated at least in part at the level of transcription. The paclitaxel biosynthetic pathway promoters contained a large number of E-box sites (CANNTG), similar to the binding sites for the key MJ-inducible transcription factor AtMYC2 from Arabidopsis thaliana. Three MJ-inducible MYC transcription factors similar to AtMYC2 (TcJAMYC1, TcJAMYC2, and TcJAMYC4) were identified in Taxus. Transcriptional regulation of paclitaxel biosynthetic pathway promoters by transient over expression of TcJAMYC transcription factors indicated a negative rather than positive regulatory role of TcJAMYCs on paclitaxel biosynthetic gene expression. PMID:25767476

  1. Cationic lipophilic complexes of /sup 99/ /SUP m/ Tc and their use for myocardial and hepatobiliary imaging

    SciTech Connect

    Deutsch, E. A.; Glavan, K. A.

    1984-12-18

    A method of imaging organs with /sup 99/ /SUP m/ Tc radiopharmaceuticals, especially of hepatobiliary imaging and negative myocardial infarct imaging in a mammal which comprises administering to the mammal a hepatobiliary or myocardial imaging amount of a cationic lipophilic complex of Tc-99m and detecting the Tc-99m complex in the mammal. A method for the preparation of cationic lipophilic complexes of Tc-99m.

  2. Infected knee prosthesis: diagnosis with In-111 leukocyte, Tc-99m sulfur colloid, and Tc-99m MDP imaging

    SciTech Connect

    Palestro, C.J.; Swyer, A.J.; Kim, C.K.; Goldsmith, S.J. )

    1991-06-01

    Forty-one possible cases of infected total knee prostheses studied with indium-111-labeled leukocyte scintigraphy were retrospectively reviewed. Twenty-four of the prostheses were studied with technetium-99m methylene diphosphonate bone scintigraphy and 19 with Tc-99m sulfur colloid marrow scintigraphy. Nine prostheses were infected, and 32 were uninfected. The accuracy of combined labeled leukocyte and sulfur colloid marrow imaging (95%) was higher than that of labeled leukocyte scintigraphy alone (78%), bone scintigraphy alone (74%), or combined labeled leukocyte and bone scintigraphy (75%). The authors conclude that combined labeled leukocyte and sulfur colloid imaging is an accurate method for diagnosis of infected knee prostheses. In this series, this technique was superior to labeled leukocyte and bone imaging, alone or in combination.

  3. 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

  4. 78 FR 7395 - Foreign-Trade Zone 129-Bellingham, WA; Notification of Proposed Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ...; T.C. Trading Company, Inc. (Eyeglass Assembly and Kitting); Blaine, WA The Port of Bellingham, grantee of FTZ 129, submitted a notification of proposed production activity on behalf of T.C. Trading Company, Inc. (T.C. Trading), located in Blaine, Washington. The notification conforming to...

  5. Focal 99mTc-DMSA Uptake in Lung Parenchyma Without Structural Alterations on SPECT/CT.

    PubMed

    Nursal, Gül Nihal; Reyhan, Mehmet; Yapar, Ali Fuat

    2015-11-01

    Static renal scintigraphy with Tc-DMSA is commonly used for the evaluation of renal morphology and function. Extrarenal uptake of Tc-DMSA is a rare finding described previously on sites such as bone metastasis, hemangioma, and splenic amyloidosis. We report a case with Tc-DMSA activity in the lungs. PMID:26053717

  6. 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.

  7. Somatostatin with 99mTc and biodistribution studies in rats.

    PubMed

    Acar, Cigdem; Teksöz, Serap; Unak, Perihan; Müftüler, F Zümrüt Biber; Medine, E Ilker

    2007-12-01

    Somatostatin (SST) is a short-lived peptide hormone that regulates the endocrine system. The main use of the derivatives of SST is to diagnose diseases related to growth hormone and to use against some forms of cancer that involve growth hormone. Also, SST suppresses gastric acid secretion, gallbladder contractions, and pancreatic enzyme secretion. In this study, two different bifunctional chelating agents were used to examine the changes in the biologic half-life of SST. For this purpose, first D-penicillamine (D-PA) and diethylene triaminepentaacetic acid (DTPA) were used to label SST with (99m)Tc and then radiopharmaceutical potential of three (99m)Tc-labeled complexes, (99m)Tc-D-PA, (99m)Tc-D-PA-SST, and (99m)Tc-DTPA-SST, were compared with each other. Quality control for each labeled complex was established by using radiochromatographic methods. The radiolabeled complexes maintained their stabilities for 5 hours. Then, biodistribution studies were performed on Albino Wistar rats independently for three complexes. The results demonstrated that (99m)Tc-D-PA-SST exhibited long-term uptake in organs, and its clearance took longer than the (99m)Tc-DTPA-SST complex. PMID:18158765

  8. 99mTc-d-penicillamine-glucuronide: synthesis, radiolabeling, in vitro and in vivo evaluation.

    PubMed

    Teksöz, Serap; Içhedef, Ci?dem Acar; Ozyüncü, Seniha; Müftüler, Fazilet Zümrüt Biber; Unak, Perihan; Medine, Ilker Emin; Ertay, Türkan; Eren, Mine ?encan

    2011-10-01

    The current study was aimed at synthesizing a glucuronide derivative of D-penicillamine (D-PA) to be used for imaging purposes. First of all, D-PA-glucuronide (D-PA-Glu) was synthesized by experimental treatments starting with uridine 5'-diphospho-glucuronosyltransferase enzyme rich microsome preparate. Then, the synthesized compound was labeled with technetium ((99m)Tc) by using a reduction method with stannous chloride. Quality controls were performed by using high-performance liquid chromatography and thin-layer radio chromatography (TLRC). Radiolabeling yield of (99m)Tc-D-PA-Glu was more than 98% according to TLRC results. In vitro evaluations of radiolabeled complexes were investigated on PC-3 human prostate cancer cells. (99m)Tc-D-PA-Glu exhibited more accumulation on PC-3 cells versus (99m)Tc-D-PA at 240 minutes. In order to determine its radiopharmaceutical potential, biodistribution studies were carried out in male Albino Wistar rats. The biodistribution results of (99m)Tc-D-PA-Glu, showed the highest uptake in prostate at 120 minutes postinjection with the main excretion route being through kidneys and bladder. (99m)Tc-D-PA-Glu and (99m)Tc-D-PA have exhibited different biodistribution results. PMID:21950558

  9. Identification and Characterization of the Trypanosoma cruzi B-cell Superantigen Tc24.

    PubMed

    Gunter, Sarah M; Jones, Kathryn M; Zhan, Bin; Essigmann, Heather T; Murray, Kristy O; Garcia, Melissa N; Gorchakov, Rodion; Bottazzi, Maria Elena; Hotez, Peter J; Brown, Eric L

    2016-01-01

    Trypanosoma cruzi causes life-long disease after infection and leads to cardiac disease in 30% of infected individuals. After infection, the parasites are readily detectable in the blood during the first few days before disseminating to infect numerous cell types. Preliminary data suggested that the Tc24 protein that localizes to the T. cruzi membrane during all life stages possesses B-cell superantigenic properties. These antigens facilitate immune escape by interfering with antibody-mediated responses, particularly the avoidance of catalytic antibodies. These antibodies are an innate host defense mechanism present in the naive repertoire, and catalytic antibody-antigen binding results in hydrolysis of the target. We tested the B-cell superantigenic properties of Tc24 by comparing the degree of Tc24 hydrolysis by IgM purified from either Tc24 unexposed or exposed mice and humans. Respective samples were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, silver stained, and the degree of hydrolysis was measured. Data presented in this report suggest that the T. cruzi Tc24 is a B-cell superantigen based on the observations that 1) Tc24 was hydrolyzed by IgM present in serum of unexposed mice and humans and 2) exposure to Tc24 eliminated catalytic activity as early as 4 days after T. cruzi infection. PMID:26598565

  10. The photoinduced transformation of fluorescent DNA base analogue tC triggers DNA melting.

    PubMed

    Preus, Søren; Jønck, Søren; Pittelkow, Michael; Dierckx, Anke; Karpkird, Thitinun; Albinsson, Bo; Wilhelmsson, L Marcus

    2013-08-01

    While fluorescent analogues of the canonical nucleobases have proven to be highly valuable in a large number of applications, up until today, fluorescent DNA base analogues remain virtually inapplicable for single-molecule fluorescence experiments which require extremely bright and photostable dyes. Insight into the photodegradation processes of these fluorophores is thus a key step in the continuous development towards dyes with improved performances. Here, we show that the commercially available fluorescent nucleobase analogue tC under intense long-term illumination and in the presence of O2 is degraded to form a single photoreaction product which we suggest to be the sulfoxide form of tC. The photoproduct is characterized by a blue-shifted absorption and a less intense fluorescence compared to that of tC. Interestingly, when tC is positioned inside double-stranded DNA this photodriven conversion of tC to its photoproduct greatly reduces the duplex stability of the overall double helix in which the probe is positioned. Since tC can be excited selectively at 400 nm, well outside the absorption band of the natural DNA bases, this observation points towards the application of tC as a general light-triggered switch of DNA duplex stability. PMID:23689311

  11. 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.

  12. 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

  13. Interdecadal changes in TC activities that affect Korea

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    The present study elucidated the fact that remarkable interdecadal variation exists in the time series of the tropical cyclone (TC) frequency that affects Korea during June-October. These variations were identified through statistical change-point analysis, and the results showed that significant variation existed in 1983 and 2004. Therefore, data in 2005 and thereafter were excluded and differences in TC activities during the period after 1983 (1984-2004) and a period before 1983 (1968-1983), as well as differences in large-scale environments were analyzed. During the period of 1984-2004, TCs mainly occurred in the northwest quadrant of the subtropical western North Pacific (SWNP). The TCs move from the east sea of Philippines, pass the East China Sea, recurved, and moved to Korea and Japan. During the period of 1968-1983, TCs occurred in the southeast quadrant of the SWNP and showed a characteristic westward movement from the southeast of Philippines toward the southern coast of China and the Indochina Peninsula. Therefore, the intensity of TCs during the former period, which were supplied with greater heat and water vapor from the sea, were stronger, while TCs during the latter period quickly dissipated after landing in the southern coast of China and the Indochina Peninsula due to the effects of topography. Thus, the lifetimes of the TCs were short and their intensities were weak. The cause of these differences in TC activities between the two periods was identified through differences in stream flows between the 850 hPa level and the 500 hPa level. At the 850 hPa level, anomalous cyclonic (anticyclonic) circulations are reinforced in most waters north (south) to 10° N, and thus, more (fewer) TCs occur in the northwest (southeast) quadrant of the SWNP during the period of 1984-2004 (1968-2003). At the 500 hPa level, since the center of anomalous cyclonic circulation is located in the southeastern region of China southeast to the east sea of the Philippines, anomalous southerlies from the east sea of Philippines to Korea and Japan are predominant. Due to the anomalous steering flows of these anomalous southerlies, the TCs during the period of 1984-2004 show the aforementioned paths. On the other hand, anomalous northerlies or northeasterlies are reinforced in regions in the west of the center of these anomalous cyclonic circulations, and thus, these anomalous steering flows serve the role of preventing TCs from moving toward the southern coast of China the Indochina Peninsula during the period of 1984-2004. During the period of 1984-2004, vertical wind shears and sea surface temperatures are high and low, respectively, in most waters of the SWNP. Therefore, more TCs occur and are reinforced during this period.

  14. Labeling, Stability and Biodistribution Studies of 99mTc-cyclized Tyr3-octreotate Derivatives

    PubMed Central

    Bigott-Hennkens, Heather M.; Dannoon, Shorouk F.; Noll, Samantha M.; Ruthengael, Varyanna C.; Jurisson, Silvia S.; Lewis, Michael R.

    2010-01-01

    Introduction To probe the interplay between radiotracer stability and somatostatin receptor affinity, Tyr3-octreotate and six variations of its peptide sequence, for which the Re-cyclized products were previously reported, were radiolabeled with 99mTc and investigated for their in vitro stability. Methods Radiolabeling of the peptides was effected by ligand exchange from 99mTc-glucoheptonate, and the desired products were purified by radio-RP-HPLC. The in vitro stability in phosphate-buffered saline, mouse serum, and cysteine solutions at physiological temperature and pH for all seven 99mTc-cyclized peptides was determined by radio-RP-HPLC and radio-TLC. Normal CF-1 mouse biodistribution studies were performed for three of the 99mTc-cyclized peptides. Results Based on the fully characterized Re-cyclized peptide analogues, four 99mTc-coordination motifs were proposed for the 99mTc-cyclized peptides. Technetium-99m-cyclized Tyr3-octreotate derivatives with N2S2 metal coordination modes and large metal ring sizes were susceptible to oxidation and loss of 99mTc in the form of 99mTcO4?, as evidenced by their instability in the various solutions under physiological conditions (15–58% intact at 24 h). As anticipated, the addition of a third cysteine to the sequence stabilized the 99mTc metal coordination, and peptides with NS3 coordination modes remained >85% intact out to 24 h. No significant differences were observed in the biodistribution studies performed with three peptides of varying stabilities. Conclusions Improvements in stability were not sufficient to outweigh the low somatostatin receptor affinity for the peptides in this study. Further improvements in the peptide sequence and/or metal coordination are needed to result in a radiodiagnostic/radiotherapeutic pair for targeting the somatostatin receptor. PMID:21531292

  15. Activity measurements of the radionuclide 99mTc for the NMIJ, Japan, in the ongoing comparison BIPM.RI(II)-K4.Tc-99m

    NASA Astrophysics Data System (ADS)

    Michotte, C.; Sato, Y.; Unno, Y.; Yunoki, A.

    2012-01-01

    In September 2011, the third comparison of activity measurements of 99mTc using the Transfer Instrument of the International Reference System (SIRTI) took place at the National Metrology Institute of Japan (NMIJ). An ampoule containing about 38 kBq of 99mTc traceable to the NMIJ primary standard was measured in the SIRTI for more than three half-lives. No 99Mo impurity had been identified in the solution. The comparison, identifier BIPM.RI(II)-K4.Tc-99m, is linked to the BIPM.RI(II)-K1.Tc-99m comparison, and the degrees of equivalence with the key comparison reference value and between the present NMIJ result, the other K4 participants and the six participants in the K1 comparison have been evaluated. World-wide consistency of activity measurements of 99mTc is demonstrated. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. Trypanosoma cruzi DTU TcII presents higher blood parasitism than DTU TcI in an experimental model of mixed infection.

    PubMed

    Sales-Campos, Helioswilton; Kappel, Henrique Borges; Andrade, Cristiane Pontes; Lima, Tiago Pereira; de Castilho, Alessandra; Giraldo, Luis Eduardo Ramirez; Lages-Silva, Eliane

    2015-09-01

    Trypanosoma cruzi (Tc), the causative agent of Chagas disease, affects millions of people worldwide. One of the major characteristics of T. cruzi is related to its heterogeneity due to the variability of its biological properties, parasite growth rates, infectivity, tissue tropism, morbidity and virulence among different isolates observed during experimental or human infection. Moreover, presence of mixed infections in the same host in endemic areas is a matter of study due to its impact on clinical manifestations and disease progression. In this study, we evaluated the biological behavior of two Tc I strains AQ1-7 (AQ) and MUTUM (MT) and one Tc II strain (JG) during the acute phase of infection, in unique and mixed infections. A patent blood parasitism was detected only in mice inoculated with JG strain . In addition blood parasitism parameters (peak and average blood parasitism) were positively associated when JG and AQ strains were combined. In contrast, a negative association was observed in the JG+MUTUM group. The predominance of TcII strain over TcI strains was highlighted using the LSSP-PCR technique, which was performed in samples from hemoculture. Thus, this study showed important biological differences between different T. cruzi strains and discrete typing units (DTUs) in acute phase. Finally, we observed that blood parasitism during early period of infection seems to be more related to DTU than to a specific strain. PMID:26204180

  17. Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

    PubMed

    Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

    2015-01-01

    This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,?) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo. PMID:25537991

  18. 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

  19. Sternal Uptake of 99mTc-MAA in Thoracic Outlet Syndrome.

    PubMed

    Matsusaka, Yohji; Nakahara, Tadaki; Iwabuchi, Yu; Kameyama, Masashi; Murakami, Koji

    2015-12-01

    Tc-macroaggregated albumin (MAA) uptake in the vertebrae has been reported in central vein occlusion, although its sternal uptake is rarely seen. We present a case in which Tc-MAA SPECT/CT showed spotty uptake in the sternum. Contrast-enhanced CT revealed marked narrowing of the left subclavian vein at the thoracic outlet with a developed collateral vein running, in the left anterior chest subcutaneous tissue, between the sternum and left axilla. In this case, IV injection of Tc-MAA from the left forearm probably led to bone marrow uptake in the sternum due to retrograde venous flow through the collateral vein. PMID:26359574

  20. Barium and Tc-poor S stars: Binary masqueraders among carbon stars

    E-print Network

    A. Jorissen; S. Van Eck

    1997-08-06

    The current understanding of the origin of barium and S stars is reviewed, based on new orbital elements and binary frequencies. The following questions are addressed: (i) Is binarity a necessary condition to produce a barium star? (ii) What is the mass transfer mode (wind accretion or RLOF?) responsible for their formation? (iii) Do barium stars form as dwarfs or as giants? (iv) Do barium stars evolve into Tc-poor S stars? (v) What is the relative frequency of Tc-rich and Tc-poor S stars?

  1. 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.

  2. 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.

    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.

  3. High-Tc superconducting microbolometer for terahertz applications

    NASA Astrophysics Data System (ADS)

    Ulysse, C.; Gaugue, A.; Adam, A.; Kreisler, A. J.; Villégier, J.-C.; Thomassin, J.-L.

    2002-05-01

    Superconducting hot electron bolometer mixers are now a competitive alternative to Schottky diode mixers in the terahertz frequency range because of their ultra wideband (from millimeter waves to visible light), high conversion gain, and low intrinsic noise level. High Tc superconductor materials can be used to make hot electron bolometers and present some advantage in term of operating temperature and cooling. In this paper, we present first a model for the study of superconducting hot electron bolometers responsivity in direct detection mode, in order to establish a firm basis for the design of future THz mixers. Secondly, an original process to realize YBaCuO hot electron bolometer mixers will be described. Submicron YBaCuO superconducting structures are expitaxially sputter deposited on MgO substrates and patterned by using electron beam lithography in combination with optical lithography. Metal masks achieved by electron beam lithography are insuring a good bridge definition and protection during ion etching. Finally, detection experiments are being performed with a laser at 850 nm wavelength, in homodyne mode in order to prove the feasibility and potential performances of these devices.

  4. The impact and recovery of asteroid 2008 TC(3).

    PubMed

    Jenniskens, P; Shaddad, M H; Numan, D; Elsir, S; Kudoda, A M; Zolensky, M E; Le, L; Robinson, G A; Friedrich, J M; Rumble, D; Steele, A; Chesley, S R; Fitzsimmons, A; Duddy, S; Hsieh, H H; Ramsay, G; Brown, P G; Edwards, W N; Tagliaferri, E; Boslough, M B; Spalding, R E; Dantowitz, R; Kozubal, M; Pravec, P; Borovicka, J; Charvat, Z; Vaubaillon, J; Kuiper, J; Albers, J; Bishop, J L; Mancinelli, R L; Sandford, S A; Milam, S N; Nuevo, M; Worden, S P

    2009-03-26

    In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections. PMID:19325630

  5. Experimental constraints on the theory of high-tc superconductivity.

    PubMed

    Anderson, P W

    1992-06-12

    Analysis of the many experiments on high-temperature superconductivity indicate several essential aspects of any theory. The conductivity and other transport properties as a function of disorder, temperature, and frequency point to a non-Fermi liquid-like behavior, whereas photoemission experiments and magnetic properties indicate the presence of a Fermi surface in momentum space. To reconcile this apparent contradiction, a new type of electron liquid, called a Luttinger liquid, has been postulated, and the present article aims to show the need for this postulate. Theory and experiment indicate that the suitable phenomenological electronic structure model of the CuO layers is that of the one-band Hubbard model. It is also argued that experiment clearly indicates that interlayer interactions strongly affect the superconducting transition temperature, T(c), consistent with the fact that no theoretical calculations on two-dimensional Hubbard models have resulted in the prediction of high transition temperatures, and that anyon models are not favored by experiment. PMID:17836318

  6. Lunar Orbit Anomaly and GM=tc^3 Cosmology

    NASA Astrophysics Data System (ADS)

    Riofrio, Louise

    2011-03-01

    Studies of the Moon at Johnson Space Center have confirmed a large anomaly in lunar orbital distance, with possible applications to Relativity. Our Lunar Laser Ranging Experiment has reported the Moon's semimajor axis increasing at 3.82 ± .07 cm/yr, anomalously high. If the Moon were gaining angular momentum at this rate, it would have coincided with Earth less than 2 Gyr ago. The Mansfield sediment (Bills, Ray 2000) measures lunar recession at 2.9 ± 0.6 cm/yr. Additional observations independently measure a recession rate of 2.82 ± .08 cm/yr. LLRE differs from independent experiments by 10 sigma. A cosmology where speed of light c is related to time t by GM=tc^3 has been suggested to predict the redshifts of Type Ia supernovae, and a 4.507034% proportion of baryonic matter (Riofrio 2004). If c were changing in the amount predicted, lunar orbital distance would appear to increase by an additional 0.935 cm/yr. An anomaly in the lunar orbit may be precisely accounted for, shedding light on puzzles of "dark energy." In Planck units this may be summarised as M=R=t.

  7. The Effect of Morphine on Regional Cerebral Blood Flow Measured by 99mTc-ECD SPECT in Dogs

    PubMed Central

    Adriaens, Antita; Peremans, Kathelijne; Waelbers, Tim; Vandermeulen, Eva; Croubels, Siska; Duchateau, Luc; Dobbeleir, André; Audenaert, Kurt; Eersels, Jos; Vermeire, Simon; De Spiegeleer, Bart; Polis, Ingeborgh

    2014-01-01

    To gain insights into the working mechanism of morphine, regional cerebral blood flow (rCBF) patterns after morphine administration were assessed in dogs. In a randomized cross-over experimental study, rCBF was estimated with 99mTc-Ethylcysteinate Dimer single photon emission computed tomography in 8 dogs at baseline, at 30 minutes and at 120 minutes after a single bolus of morphine. Perfusion indices (PI) in the frontal, parietal, temporal and occipital cortex and in the subcortical and cerebellar region were calculated. PI was significantly decreased 30 min after morphine compared to baseline in the right frontal cortex. The left parietal cortex and subcortical region showed a significantly increased PI 30 min after morphine compared to baseline. No significant differences were noted for the other regions or at other time points. In conclusion, a single bolus of morphine generated a changing rCBF pattern at different time points. PMID:25295733

  8. Effect of Co-Ligands on Chemical and Biological Properties of 99mTc(III) Complexes [99mTc(L)(CDO)(CDOH)2BMe] (L = Cl, F, SCN and N3; CDOH2 = Cyclohexanedione Dioxime)

    PubMed Central

    Zheng, Yumin; Ji, Shundong; Tomaselli, Elena; Ernest, Carley; Freiji, Tom; Liu, Shuang

    2015-01-01

    Introduction 99mTc-Teboroxime ([99mTcCl(CDO)(CDOH)2BMe]) is a member of the BATO (boronic acid adducts of technetium dioximes) class of 99mTc(III) complexes. This study sought to explore the impact of co-ligands on solution stability, heart uptake and myocardial retention of [99mTc(L)(CDO)(CDOH)2BMe] (99mTc-Teboroxime: L = Cl; 99mTc-Teboroxime(F): L = F; 99mTc-Teboroxime(SCN): L = SCN; and 99mTc-Teboroxime(N3): L = N3). Methods Radiotracers 99mTc-Teboroxime(L) (L = F, SCN and N3) were prepared by reacting 99mTc-Teboroxime with NaF, NaSCN and NaN3, respectively. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their heart retention and liver clearance kinetics. Results Complexes 99mTc-Teboroxime(L) (L = F, SCN and N3) were prepared in high yield with high radiochemical purity. All new radiotracers were stable for >6 h in the kit matrix. In its HPLC chromatogram, 99mTc-Teboroxime showed one peak at ~15.5 min, which was shorter than that of 99mTc-Teboroxime(F) (~16.4 min). There were two peaks for 99mTc-Teboroxime(SCN) at 16.5 and 18.3 min. 99mTc-Teboroxime(N3) appeared as a single peak at 18.4 min. Their heart retention and liver clearance curves were best fitted to the bi-exponential decay function. The half-times of fast/slow components were 1.6 ± 0.4/60.7±8.9 min for 99mTc-Teboroxime, 0.8±0.2/101.7±20.7 min for 99mTc-Teboroxime(F), 1.2±0.3/84.8±16.6 min for 99mTc-Teboroxime(SCN), and 2.9±0.9/51.6±5.0 min for 99mTc-Teboroxime(N3). The 2-min heart uptake followed the order of 99mTc-Teboroxime (3.00±0.37%ID/g) > 99mTc-Teboroxime(N3) (2.66±0.01 %ID/g) ? 99mTc-Sestamibi (2.55±0.46 %ID/g) > 99mTcN-MPO (2.38±0.15 %ID/g). 99mTc-Teboroxime remains the best in first-pass extraction. The best image acquisition window is 0 – 5 min for 99mTc-Teboroximine and 0 – 15 min for 99mTc-Teboroximine(N3). Conclusion Co-ligands had significant impact on the heart uptake and myocardial retention of complexes [99mTc(L)(CDO)(CDOH)2BMe] (L = Cl, F, SCN and N3). Future studies should be directed towards minimizing the liver uptake and radioactivity accumulation in the blood vessels while maintaining their high heart uptake. PMID:25169135

  9. Tc-cAPX, a cytosolic ascorbate peroxidase of Theobroma cacao L. engaged in the interaction with Moniliophthora perniciosa, the causing agent of witches' broom disease.

    PubMed

    Camillo, Luciana Rodrigues; Filadelfo, Ciro Ribeiro; Monzani, Paulo Sérgio; Corrêa, Ronan Xavier; Gramacho, Karina Peres; Micheli, Fabienne; Pirovani, Carlos Priminho

    2013-12-01

    The level of hydrogen peroxide (H2O2) in plants signalizes the induction of several genes, including that of ascorbate peroxidase (APX-EC 1.11.1.11). APX isoenzymes play a central role in the elimination of intracellular H2O2 and contribute to plant responses to diverse stresses. During the infection process in Theobroma cacao by Moniliophthora perniciosa oxidative stress is generated and the APX action recruited from the plant. The present work aimed to characterize the T. cacao APX involved in the molecular interaction of T. cacao-M. perniciosa. The peroxidase activity was analyzed in protein extracts from cocoa plants infected by M. perniciosa and showed the induction of peroxidases like APX in resistant cocoa plants. The cytosolic protein of T. cacao (GenBank: ABR68691.2) was phylogenetically analyzed in relation to other peroxidases from the cocoa genome and eight genes encoding APX proteins with conserved domains were also analyzed. The cDNA from cytosolic APX was cloned in pET28a and the recombinant protein expressed and purified (rTc-cAPX). The secondary structure of the protein was analyzed by Circular Dichroism (CD) displaying high proportion of ?-helices when folded. The enzymatic assay shows stable activity using ascorbate and guaiacol as an electron donor for H2O2 reduction. The pH 7.5 is the optimum for enzyme activity. Chromatographic analysis suggests that rTc-cAPX is a homodimer in solution. Results indicate that the rTc-cAPX is correctly folded, stable and biochemically active. The purified rTc-cAPX presented biotechnological potential and is adequate for future structural and functional studies. PMID:24161755

  10. Intrinsic MyD88-Akt1-mTOR Signaling Coordinates Disparate Tc17 and Tc1 Responses during Vaccine Immunity against Fungal Pneumonia

    PubMed Central

    Nanjappa, Som Gowda; Hernández-Santos, Nydiaris; Galles, Kevin; Wüthrich, Marcel; Suresh, M.; Klein, Bruce S.

    2015-01-01

    Fungal infections have skyrocketed in immune-compromised patients lacking CD4+ T cells, underscoring the need for vaccine prevention. An understanding of the elements that promote vaccine immunity in this setting is essential. We previously demonstrated that vaccine-induced IL-17A+ CD8+ T cells (Tc17) are required for resistance against lethal fungal pneumonia in CD4+ T cell-deficient hosts, whereas the individual type I cytokines IFN-?, TNF-? and GM-CSF, are dispensable. Here, we report that T cell-intrinsic MyD88 signals are crucial for these Tc17 cell responses and vaccine immunity against lethal fungal pneumonia in mice. In contrast, IFN-?+ CD8+ cell (Tc1) responses are largely normal in the absence of intrinsic MyD88 signaling in CD8+ T cells. The poor accumulation of MyD88-deficient Tc17 cells was not linked to an early onset of contraction, nor to accelerated cell death or diminished expression of anti-apoptotic molecules Bcl-2 or Bcl-xL. Instead, intrinsic MyD88 was required to sustain the proliferation of Tc17 cells through the activation of mTOR via Akt1. Moreover, intrinsic IL-1R and TLR2, but not IL-18R, were required for MyD88 dependent Tc17 responses. Our data identify unappreciated targets for augmenting adaptive immunity against fungi. Our findings have implications for designing fungal vaccines and immune-based therapies in immune-compromised patients. PMID:26367276

  11. Infrared Two-Color Multicycle Laser Field Synthesis for Generating an Intense Attosecond Pulse

    SciTech Connect

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

    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.

  12. Vertebral Hemangiolymphangioma Mimics Bone Metastases on 99mTc-MDP SPECT/CT.

    PubMed

    Zhang, Yiqiu; Li, Beilei; Shi, Hongcheng; Cai, Liang; Hou, Jun

    2016-01-01

    Hemangiolymphangioma is a very rare, congenital malformation of both lymphatic and blood vessels. In the present study, we report a case of vertebral hemangiolymphangioma that was misdiagnosed as bone metastasis on Tc-MDP SPECT/CT. PMID:26359559

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    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 × 10 5 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, either in aqueous form (Fe 2+) or in mineral form [Fe(II)], 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) has 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. Surface Fe-oxides were removed from these minerals with a modified dithionite-citrate-bicarbonate (DCB) procedure. The total structural Fe content of these clay minerals, after surface Fe-oxide removal, ranged from 0.7% to 30.4% by weight, and the structural Fe(III)/Fe(total) ratio ranged from 45% to 98%. 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 structural Fe(III) in the clay minerals as the sole electron acceptor, lactate as the sole electron donor, and Shewanella putrefaciens CN32 cells as a mediator. In select tubes, anthraquinone-2,6-disulfate (AQDS) was added as electron shuttle to facilitate electron transfer. In the S-I series, smectite (montmorillonite) was the most reducible (18% and 41% without and with AQDS, respectively) and illite the least (1% for both without and with AQDS). 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 NAu-2 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.

  18. Tc-99m labeled leukocytes: preparation and use in identification of abscess and tissue rejection

    SciTech Connect

    Farid, N.A.; White, S.M.; Heck, L.L.; Van Hove, E.D.

    1983-09-01

    A simple and reproducible method for the preparation and labeling of leukocytes with Tc-99m has been developed. Leukocytes were separated from blood, incubated with stannous pyrophosphate, and then with 20-30 mCi (740-1110 MBq) of /sup 99m/TcO-4. In leukocytes separated from human blood, the labeling efficiency was 81% +/- 6% (n . 4). Experiments on dogs with abscesses showed accumulation of the Tc-99m-labeled leukocytes in the infected sites, indicating the viability of the labeled leukocytes. Additional studies showed that rat lymphocytes that were labeled with Tc-99m, using the same technique, localized in heart transplant tissue that was being rejected.

  19. Crossed Fused Renal Ectopia: Presentations on 99mTc-MAG3 Scan, 99mTc-DMSA SPECT, and Multidetector CT.

    PubMed

    Moon, Eun Ha; Kim, Min-Woo; Kim, Young Jun; Sun, In O

    2015-10-01

    Crossed renal ectopia is an uncommon developmental anomaly in which both kidneys are located on the same side of the body. The present case describes a 20-year-old man who underwent the military entrance physical examination. The ultrasound showed the right kidney in normal site with slightly increased size, but the left kidney was not identified. Tc-MAG3 scan showed a single kidney with 2 ureters, and the orifices of the ureters were connected at both sides of bladder. Tc-DMSA SPECT and contrast-enhanced multidetector CT were performed and revealed crossed fused renal ectopia. PMID:26252333

  20. TcVac3 Induced Control of Trypanosoma cruzi Infection and Chronic Myocarditis in Mice

    PubMed Central

    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. /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.

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

    SciTech Connect

    Phillips, W.T.; Klipper, R.; Goins, B.

    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.

  3. 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.

  4. Investigation of Tc Migration Mechanism During Bulk Vitrification Process Using Re Surrogate

    SciTech Connect

    Kim, Dong-Sang; Bagaasen, Larry M.; Crum, Jarrod V.; Fluegel, Alex; Gallegos, Autumn B.; Martinez, Baudelio; Matyas, Josef; Meyer, Perry A.; Paulsen, Dan; Riley, Brian J.; Schweiger, Michael J.; Stewart, Charles W.; Swoboda, Robert G.; Yeager, John D.

    2006-12-04

    As a part of Bulk vitrification (BV) performance enhancement tasks, Laboratory scoping tests were performed in FY 2004-2005 to explore possible ways to reduce the amount of soluble Tc in the BV waste package. Theses scoping tests helped identify which mechanisms play an important role in the migration of Tc in the BV process (Hrma et al. 2005 and Kim et al. 2005). Based on the results from these scoping tests, additional tests were identified that will improve the understanding of Tc migration and to clearly identify the dominant mechanisms. The additional activities identified from previous studies were evaluated and prioritized for planning for Tasks 29 and 30 conducted in FY2006. Task 29 focused on the improved understanding of Tc migration mechanisms, and Task 30 focused on identifying the potential process changes that might reduce Tc/Re migration into the castable refractory block (CRB). This report summarizes the results from the laboratory- and crucible-scale tests in the lab for improved Tc migration mechanism understanding utilizing Re as a surrogate performed in Task 29.

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

    SciTech Connect

    Paviet-Hartmann, P.

    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.

  6. 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.

  7. Synthesis of several tetraaza macrocyclic amine ligands and the biodistribution of their Tc-complexes

    SciTech Connect

    Ketring, A.R.

    1982-01-01

    Several macrocyclic tetraaza ligands were synthesized and their /sup 99m/Tc-complexes prepared. The biological distribution of these complexes was examined to determine their possible utility as radiodiagnostic agents. The simplest of the macrocyclic tetraaza ligands studied, cyclam, forms a very stable cationic complex with Tc when pertechnetate is reduced with stannous ion in an aqueous solution of the ligand. When injected intravenously into mice Tc-cyclam was excreted predominantly by the urinary system. Derivatives of cyclam which were synthesized contained aromatic or aliphatic substituents and formed more lipophilic complexes with Tc. The complexes were formed in high yield as determined by paper chromatography, thin layer chromatography, electrophoresis and/or high performance liquid chromatography. Relative lipophilicities were determined for the complexes by octanol-to-water extractions. Animal studies using mice indicated there was an inverse relationship between the octanol-to-water extraction ratio and urinary excretion. Two of the complexes having relatively high octanol-to-water extraction ratios were significantly excreted by the hepatobiliary system with localization in the gall bladder. The complex having the highest octanol-to-water ratio was not excreted significantly by the hepatobiliary system, but cleared very slowly from the blood and localized in the liver, lungs, spleen and to some extent the heart. Derivatization of cyclam can be performed without greatly reducing its ability to complex Tc but greatly influencing the biological distribution of its Tc complex. This indicates that there is a potential for preparing radiodiagnostic agents using macrocyclic tetraaza ligands.

  8. Possible influence of western North Pacific monsoon on TC activity in mid-latitudes of East Asia

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    This study analyzed the correlation between tropical cyclone (TC) frequency and the Western North Pacific monsoon index (WNPMI), which have both been influential in East Asia's mid-latitude regions during the summer season over the past 37 years (1977-2013). A high positive correlation existed between these two variables, which was not reduced even if El Niño-Southern Oscillation (ENSO) years were excluded. To determine the cause of this positive correlation, the highest (positive WNPMI phase) and lowest WNPMIs (negative WNPMI phase) during a nine-year period were selected to analyze the mean difference between them, excluding ENSO years. In the positive WNPMI phase, TCs were mainly generated in the eastern seas of the tropical and subtropical western North Pacific, passing through the East China Sea and moving northward toward Korea and Japan. In the negative phase, TCs were mainly generated in the western seas of the tropical and subtropical western North Pacific, passing through the South China Sea and moving westward toward China's southern regions. Therefore, TC intensity in the positive phase was stronger due to the acquisition of sufficient energy from the sea while moving a long distance up to East Asia's mid-latitude. Additionally, TCs occurred more in the positive phase. Regarding the difference of the two phases between the 850 and 500-hPa streamlines, anomalous cyclones were strengthened in the tropical and subtropical western North Pacific, whereas anomalous anticyclones were strengthened in East Asia's mid-latitude regions. Due to these two anomalous pressure systems, anomalous southeasterlies developed in East Asia's mid-latitude regions, which played a role in the anomalous steering flows that moved TCs into these regions. Furthermore, due to the anomalous cyclones that developed in the tropical and subtropical western North Pacific, more TCs could be generated in the positive phase. Both the lower and upper tropospheric layers had warm anomalies in most regions of the Western North Pacific, while relative humidity in the middle tropospheric layer showed a positive anomaly in the tropical and subtropical western North Pacific, which provided a better environment to strengthen TC intensity in the positive WNPMI phase. Furthermore, a negative anomaly was manifested not only in the tropical and subtropical western North Pacific, but also in East Asia's mid-latitude regions, with 200-850-hPa vertical wind shear, while a warm sea surface temperature anomaly was shown in East Asia's mid-latitude seas, which further strengthened TC intensity in the positive phase. The analysis on the global-scale atmospheric circulations showed that converged air in the lower layer of the subtropical western Pacific during the positive phase diverged in the upper layer, which moved westward and converged in the upper layer of the equatorial Indian Ocean and then diverged in its lower layer.

  9. Activity measurements of the radionuclide 99mTc for the NIM, China in the ongoing comparison BIPM.RI(II)-K4.Tc-99m

    NASA Astrophysics Data System (ADS)

    Michotte, C.; Nonis, M.; Liang, J. C.; Chen, J.; Liu, H. R.; Zhang, M.; Zhao, Q.; Yang, Y. D.

    2013-01-01

    In 2012, the fourth comparison of activity measurements of 99mTc using the Transfer Instrument of the International Reference System (SIRTI) took place at the Chinese National Institute of Metrology (NIM). An ampoule containing about 70 kBq of 99mTc traceable to the NIM primary standard was measured in the SIRTI for more than three half-lives. The comparison, identifier BIPM.RI(II)-K4.Tc-99m, is linked to the BIPM.RI(II)-K1.Tc-99m comparison and the degrees of equivalence with the key comparison reference value and between the present NIM result, the other K4 participant and the six participants in the K1 comparison have been evaluated. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. Activity measurements of the radionuclide 99mTc for the IFIN-HH, Romania in the ongoing comparison BIPM.RI(II)-K4.Tc-99m

    NASA Astrophysics Data System (ADS)

    Michotte, C.; Sahagia, M.; Ioan, M. R.; Antohe, A.; Luca, A.

    2014-01-01

    In 2013, a comparison of activity measurements of 99mTc using the Transfer Instrument of the International Reference System (SIRTI) took place at the Institutul National de Cercetare - Dezvoltare in Fizica si Inginerie Nucleara - 'Horia Hulubei' (IFIN-HH, Romania). Ampoules containing about 21 kBq and 40 kBq of a 99mTc solution were measured in the SIRTI for, respectively, one and three half-lives. The comparison, identifier BIPM.RI(II)-K4.Tc-99m, is linked to the BIPM.RI(II)-K1.Tc-99m comparison and the degrees of equivalence with the key comparison reference value and between the present IFIN-HH result, the other K4 participants and the six participants in the K1 comparison have been evaluated. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  11. 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.

  12. Overexpression of Cytoplasmic TcSIR2RP1 and Mitochondrial TcSIR2RP3 Impacts on Trypanosoma cruzi Growth and Cell Invasion

    PubMed Central

    Ritagliati, Carla; Alonso, Victoria L.; Manarin, Romina; Cribb, Pamela; Serra, Esteban C.

    2015-01-01

    Background Trypanosoma cruzi is a protozoan pathogen responsible for Chagas disease. Current therapies are inadequate because of their severe host toxicity and numerous side effects. The identification of new biotargets is essential for the development of more efficient therapeutic alternatives. Inhibition of sirtuins from Trypanosoma brucei and Leishmania ssp. showed promising results, indicating that these enzymes may be considered as targets for drug discovery in parasite infection. Here, we report the first characterization of the two sirtuins present in T. cruzi. Methodology Dm28c epimastigotes that inducibly overexpress TcSIR2RP1 and TcSIR2RP3 were constructed and used to determine their localizations and functions. These transfected lines were tested regarding their acetylation levels, proliferation and metacyclogenesis rate, viability when treated with sirtuin inhibitors and in vitro infectivity. Conclusion TcSIR2RP1 and TcSIR2RP3 are cytosolic and mitochondrial proteins respectively. Our data suggest that sirtuin activity is important for the proliferation of T. cruzi replicative forms, for the host cell-parasite interplay, and for differentiation among life-cycle stages; but each one performs different roles in most of these processes. Our results increase the knowledge on the localization and function of these enzymes, and the overexpressing T. cruzi strains we obtained can be useful tools for experimental screening of trypanosomatid sirtuin inhibitors. PMID:25875650

  13. Solubility Control of Technetium Release from Saltstone by Tc02•xH20

    SciTech Connect

    Cantrell, Kirk J.; Williams, Benjamin D.

    2013-11-12

    Saltstone leaching experiments were conducted using a modified single-pass flow-through method under anoxic conditions. The analytical results of leachates collected from these experiments were evaluated using thermodynamic modeling to determine if the data were consistent with potential solubility controlling phases. The results demonstrate that technetium concentrations in water in contact with Saltstone under anoxic conditions is controlled by the solubility of TcO2•xH2O (likely TcO2•1.6H2O). In our system equilibrium solubility appears to have been reached within two weeks at a concentration of approximately 1.5 x 10-6 M. This concentration is likely to vary as the composition of Saltstone pore fluid evolves over time. As the pH goes from the initial high values (~12.5-13) to lower values, the solubility of technetium will decrease significantly. The thermodynamic data used to determine the solubility of TcO2•1.6H2O were taken from the tabulation of critically selected thermodynamic data determined by the Nuclear Energy Agency. Solid phase characterization to demonstrate the presence of TcO2•xH2O was not possible due to the low concentrations of technetium in our samples. Previous solid phase characterization studies with cementitious waste forms that were very similar to our Saltstone samples as well as reaction products derived from reductive immobilization of TcO4- by amorphous FeS clearly indicate the presence of TcO2 with varying degrees of hydration. Although, the presence of TcSx or other reduced technetium sulfide phases in our samples cannot be ruled out, release of technetium from Saltstone will be controlled by TcO2•1.6H2O because of its higher solubility. Our results clearly demonstrate that the release mechanism of technetium from Saltstone under reducing conditions is solubility controlled by TcO2•xH2O (likely TcO2•1.6H2O); however, distribution coefficients (Kds), that describe sorption and not solubility, were calculated for comparison with past literature values. After 84 days of reaction under anoxic conditions, the average Kd value for technetium was determined to be 610 mL/g. This value is similar to a value determined previously for a similar saltstone sample under reducing conditions at 56 days (712 ± 81 mL/g).

  14. Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by analytical characterization of radiopharmaceutical mixtures. Progress report, September 1, 1989--January 31, 1992

    SciTech Connect

    Heineman, W.R.

    1992-01-24

    The long-range objective of this research program is the development of more efficacious technetium-99m radiopharmaceuticals for use as imaging agents in diagnostic nuclear medicine. We seek to isolate and develop distinct site imaging agents, each of which has properties optimized to provide diagnostic information concerning a given pathological condition. The specific objectives during the period (9/1/89 to 8/31/92) include: (1) Development of strategies for improving yields of specific Tc-diphosphonate complexes with optimum imaging properties; (2) Development of electrodes for rapid in situ electrochemical generation of skeletal imaging agents; (3) Development of electrochemical sensors for {Tc} and Re imaging agents; (4) Characterization of stable {Tc}- and Re-diphosphonate complexes obtainable in high yield by structural studies with techniques such as NMR, EXAFS, and Raman spectroscopy; (5) Development of improved separation techniques for the characterization of diphosphonate skeletal imaging agents; (6) Evaluation of the effect of the biological milieu on {Tc}-diphosphonate complexes; and (7) Electrochemical studies of technetium and rhenium complexes synthesized by Professor Deutsch`s research group for heart and brain imaging.

  15. Central role of Th2/Tc2 lymphocytes in pattern II multiple sclerosis lesions

    PubMed Central

    Planas, Raquel; Metz, Imke; Ortiz, Yaneth; Vilarrasa, Nuria; Jel?i?, Ilijas; Salinas-Riester, Gabriela; Heesen, Christoph; Brück, Wolfgang; Martin, Roland; Sospedra, Mireia

    2015-01-01

    Objective Multiple sclerosis (MS) is a disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Based on infiltrating immune cells, deposition of humoral factors and loss of oligodendrocytes and/or myelin proteins, four lesion patterns have been described. Pattern II is characterized by antibody and complement deposition in addition to T-cell infiltration. MS is considered a T-cell-mediated disease, but until now the study of pathogenic T cells has encountered major challenges, most importantly the limited access of brain-infiltrating T cells. Our objective was to identify, isolate, and characterize brain-infiltrating clonally expanded T cells in pattern II MS lesions. Methods We used next-generation sequencing to identify clonally expanded T cells in demyelinating pattern II brain autopsy lesions, subsequently isolated these as T-cell clones from autologous cerebrospinal fluid and functionally characterized them. Results We identified clonally expanded CD8+ but also CD4+ T cells in demyelinating pattern II lesions and for the first time were able to isolate these as live T-cell clones. The functional characterization shows that T cells releasing Th2 cytokines and able to provide B cell help dominate the T-cell infiltrate in pattern II brain lesions. Interpretation Our data provide the first functional evidence for a putative role of Th2/Tc2 cells in pattern II MS supporting the existence of this pathogenic phenotype and questioning the protective role that is generally ascribed to Th2 cells. Our observations are important to consider for future treatments of pattern II MS patients. PMID:26401510

  16. Evaluating {sup 99m}Tc Auger electrons for targeted tumor radiotherapy by computational methods

    SciTech Connect

    Tavares, Adriana Alexandre S.; Tavares, Joao Manuel R. S.

    2010-07-15

    Purpose: Technetium-99m ({sup 99m}Tc) has been widely used as an imaging agent but only recently has been considered for therapeutic applications. This study aims to analyze the potential use of {sup 99m}Tc Auger electrons for targeted tumor radiotherapy by evaluating the DNA damage and its probability of correct repair and by studying the cellular kinetics, following {sup 99m}Tc Auger electron irradiation in comparison to iodine-131 ({sup 131}I) beta minus particles and astatine-211 ({sup 211}At) alpha particle irradiation. Methods: Computational models were used to estimate the yield of DNA damage (fast Monte Carlo damage algorithm), the probability of correct repair (Monte Carlo excision repair algorithm), and cell kinetic effects (virtual cell radiobiology algorithm) after irradiation with the selected particles. Results: The results obtained with the algorithms used suggested that {sup 99m}Tc CKMMX (all M-shell Coster-Kroning--CK--and super-CK transitions) electrons and Auger MXY (all M-shell Auger transitions) have a therapeutic potential comparable to high linear energy transfer {sup 211}At alpha particles and higher than {sup 131}I beta minus particles. All the other {sup 99m}Tc electrons had a therapeutic potential similar to {sup 131}I beta minus particles. Conclusions: {sup 99m}Tc CKMMX electrons and Auger MXY presented a higher probability to induce apoptosis than {sup 131}I beta minus particles and a probability similar to {sup 211}At alpha particles. Based on the results here, {sup 99m}Tc CKMMX electrons and Auger MXY are useful electrons for targeted tumor radiotherapy.

  17. 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

    2015-01-01

    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

  18. ISO TC211 standards on Provenance for Earth science

    NASA Astrophysics Data System (ADS)

    Di, L.; Deng, M.

    2014-12-01

    Data provenance, also called lineage, records the derivation history of a data product. The history could include the algorithms used, the process steps taken, the computing environment run, data sources input to the processes, the organization/person responsible for the product, etc. Provenance provides important information to data users for them to determine the usability and reliability of the product. In the science domain, the data provenance is especially important since scientists need to use the information to determine the scientific validity of a data product and to decide if such a product can be used as the basis for further scientific analysis. Provenance is a kind of metadata. In Earth science domain, the International Organization for Standardization (ISO) Technical Committee 211 (ISO TC 211) have set geospatial metadata standards for geospatial data, including ISO 19115:2003-Metadata, ISO 19115-2:2009-Metadata-Part 2: Extensions for imagery and gridded data, and ISO 19115-1:2014 - Metadata -- Part 1: Fundamentals. ISO 19115 and ISO 19115-1 define the fundamental metadata for documenting geospatial data products, and ISO 19115-2 provides additional metadata classes for imagery and gridded data. ISO 19115-1:2014 is the revised version of ISO 19115:2003. ISO 19115 and ISO 19115-1 define fundamental lineage information classes and subclasses. They miss some key information classes needed for documenting the provenance in the Web service environment, such as the running environment, the algorithms, and software executables. However, ISO 19115-2 extends the lineage model in ISO 19115 and provides additional metadata classes needed for documenting provenance information. The combination of lineage models in ISO 19115 and ISO 19115-2 provides a comprehensive provenance information model needed for the web service environment. Currently the ISO Provence standard is not compatible with W3C Prov standard. The revision of ISO 19115-2 will be started in November 2014. The revision process will provide the opportunity for harmonizing the ISO provenance model with the W3C Prov standard and for the Earth science community to provide inputs for improving the ISO provenance model.

  19. Diagnostic Performance of an Expert System for Interpretation of 99mTc MAG3 Scans in Suspected Renal Obstruction

    PubMed Central

    Taylor, Andrew; Garcia, Ernest V.; Binongo, Jose Nilo G.; Manatunga, Amita; Halkar, Raghuveer; Folks, Russell D.; Dubovsky, Eva

    2011-01-01

    The purpose of the study was to compare diuresis renography scan interpretation generated by a renal expert system with the consensus interpretation of 3 expert readers. Methods The expert system was evaluated in 95 randomly selected furosemide-augmented patient studies (185 kidneys) obtained for suspected obstruction; there were 55 males and 40 females with a mean age ± SD of 58.6 ± 16.5 y. Each subject had a baseline 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) scan followed by furosemide administration and a separate 20-min acquisition. Quantitative parameters were automatically extracted from baseline and furosemide acquisitions and forwarded to the expert system for analysis. Three experts, unaware of clinical information, independently graded each kidney as obstructed/probably obstructed, equivocal, and probably nonobstructed/nonobstructed; experts resolved differences by a consensus reading. These 3 expert categories were compared with the obstructed, equivocal, and nonobstructed interpretations provided by the expert system. Agreement was assessed using weighted ?, and the predictive accuracy of the expert system compared with expert readers was assessed by the area under receiver-operating-characteristic (ROC curve) curves. Results The expert system agreed with the consensus reading in 84% (101/120) of nonobstructed kidneys, in 92% (33/36) of obstructed kidneys, and in 45% (13/29) of equivocal kidneys. The weighted ? between the expert system and the consensus reading was 0.72 and was comparable with the weighted ? between experts. There was no significant difference in the areas under the ROC curves when the expert system was compared with each expert using the other 2 experts as the gold standard. Conclusion The renal expert system showed good agreement with the expert interpretation and could be a useful educational and decision support tool to assist physicians in the diagnosis of renal obstruction. To better mirror the clinical setting, algorithms to incorporate clinical data must be designed, implemented, and tested. PMID:18199609

  20. Immune Protection against Trypanosoma cruzi Induced by TcVac4 in a Canine Model

    PubMed Central

    Aparicio-Burgos, José E.; Zepeda-Escobar, José A.; de Oca-Jimenez, Roberto Montes; Estrada-Franco, José G.; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Alejandre-Aguilar, Ricardo; Rivas, Nancy; Peñuelas-Rivas, Giovanna; Val-Arreola, Margarita; Gupta, Shivali; Salazar-García, Felix; Garg, Nisha J.; Vázquez-Chagoyán, Juan C.

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GM-CSF-encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs. We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines. PMID:25853654

  1. 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.

  2. Solvent extraction of [sup 99]Tc from radioactive intermediate liquid waste by dibenzo-18-crown-6.

    SciTech Connect

    Paviet-Hartmann, P.

    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.

  3. 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.

  4. Transforming properties of TC-1 in human breast cancer: interaction with FGFR2 and beta-catenin signaling pathways.

    PubMed

    Yang, Zeng-Quan; Moffa, Allison B; Haddad, Ramsi; Streicher, Katie L; Ethier, Stephen P

    2007-09-15

    Breast cancer development is associated with gene amplification and over expression that is believed to have a causative role in oncogenesis. Previous studies have demonstrated that over expression of TC-1(C8orf4) mRNA occurs in approximately 50% of breast cancer cell lines and primary tumor specimens. Here, we show that TC-1 has transforming properties in human mammary epithelial (HME) cells and its expression is mechanistically linked to FGFR signaling cascades. In vitro experiments demonstrate that TC-1 over expression mediates both anchorage-independent and growth factor-independent proliferation of HME cells. TC-1 was down regulated by the FGFR inhibitor PD173074 in the breast cancer cell line SUM-52 that also has an FGFR2 gene amplification and over expression. Furthermore, forced expression of FGFR2 in HME cells increased the level of expression of endogenous TC-1 mRNA. TC-1 has been implicated as a modulator of Wnt/beta-catenin signaling in 293 cells and in gastric cancer cells. However, while we did find increased expression of a subset of beta-catenin target genes in TC-1 over expressing cells, we did not find an association of TC-1 with global expression of beta-catenin target genes in our cells. Taken together, our data suggest that TC-1 over expression is transforming and may link with the FGFR pathway in a subset of breast cancer. PMID:17520678

  5. A Novel Phthalimide Derivative, TC11, Has Preclinical Effects on High-Risk Myeloma Cells and Osteoclasts

    PubMed Central

    Matsushita, Maiko; Ozaki, Yoshie; Hasegawa, Yuka; Terada, Fukiko; Tabata, Noriko; Shiheido, Hirokazu; Yanagawa, Hiroshi; Oikawa, Tsukasa; Matsuo, Koichi; Du, Wenlin; Yamada, Taketo; Hozumi, Masashi; Ichikawa, Daiju; Hattori, Yutaka

    2015-01-01

    Despite the recent advances in the treatment of multiple myeloma (MM), MM patients with high-risk cytogenetic changes such as t(4;14) translocation or deletion of chromosome 17 still have extremely poor prognoses. With the goal of helping these high-risk MM patients, we previously developed a novel phthalimide derivative, TC11. Here we report the further characterization of TC11 including anti-myeloma effects in vitro and in vivo, a pharmacokinetic study in mice, and anti-osteoclastogenic activity. Intraperitoneal injections of TC11 significantly delayed the growth of subcutaneous tumors in human myeloma-bearing SCID mice. Immunohistochemical analyses showed that TC11 induced apoptosis of MM cells in vivo. In the pharmacokinetic analyses, the Cmax was 2.1 ?M at 1 h after the injection of TC11, with 1.2 h as the half-life. TC11 significantly inhibited the differentiation and function of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts in mouse osteoclast cultures using M-CSF and RANKL. We also revealed that TC11 induced the apoptosis of myeloma cells accompanied by ?-tubulin fragmentation. In addition, TC11 and lenalidomide, another phthalimide derivative, directly bound to nucleophosmin 1 (NPM1), whose role in MM is unknown. Thus, through multiple molecular interactions, TC11 is a potentially effective drug for high-risk MM patients with bone lesions. The present results suggest the possibility of the further development of novel thalidomide derivatives by drug designing. PMID:25617756

  6. Tc-99m-labeled red blood cells for the measurement of red cell mass in newborn infants: concise communication

    SciTech Connect

    Linderkamp, O.; Betke, K.; Fendel, H.; Klemm, J.; Lorenzen, K.; Riegel, K.P.

    1980-07-01

    In vitro and in vivo investigations were performed to examine the binding of Tc-99m to neonatal red blood cells (RBC). Labeling efficiency was about 90%, and unbound Tc-99m less than 3% after one washing, in premature and full-term newborns and in children. Thus presence of high percentages of fetal hemoglobin (Hb F) did not influence the labeling of RBCs with Tc-99m. RBCs of 11 newborns were hemolysed and the distribution of Tc-99m on RBC components was analyzed. Although Hb F percentage averaged (60.0 +- 8.10)% (s.d.), only (11.9 +- 3.7)% of Tc-99m was bound by Hb F, whereas (45.0 +- 6.1)% was associated with Hb A. RBC membranes bound (13.7 +- 4.3)% and (29.3 +- 4.0)% were found unbound in hemolysates. These results indicate that Tc-99m preferentially binds to beta chains. In vivo equilibration of Tc-99m RBCs and of albumin labeled with Evans blue was investigated in five newborn infants. Tc-99m RBCs were stable in each case during the first hour after injection. Elution of Tc-99m from RBCs was (3.4 +- 1.5)% per h. Body-to-venous hematocrit ratio averaged 0.86 +- 0.03.

  7. Exact calculation of the time convolutionless master equation generator: Application to the nonequilibrium resonant level model.

    PubMed

    Kidon, Lyran; Wilner, Eli Y; Rabani, Eran

    2015-12-21

    The generalized quantum master equation provides a powerful tool to describe the dynamics in quantum impurity models driven away from equilibrium. Two complementary approaches, one based on Nakajima-Zwanzig-Mori time-convolution (TC) and the other on the Tokuyama-Mori time-convolutionless (TCL) formulations provide a starting point to describe the time-evolution of the reduced density matrix. A key in both approaches is to obtain the so called "memory kernel" or "generator," going beyond second or fourth order perturbation techniques. While numerically converged techniques are available for the TC memory kernel, the canonical approach to obtain the TCL generator is based on inverting a super-operator in the full Hilbert space, which is difficult to perform and thus, nearly all applications of the TCL approach rely on a perturbative scheme of some sort. Here, the TCL generator is expressed using a reduced system propagator which can be obtained from system observables alone and requires the calculation of super-operators and their inverse in the reduced Hilbert space rather than the full one. This makes the formulation amenable to quantum impurity solvers or to diagrammatic techniques, such as the nonequilibrium Green's function. We implement the TCL approach for the resonant level model driven away from equilibrium and compare the time scales for the decay of the generator with that of the memory kernel in the TC approach. Furthermore, the effects of temperature, source-drain bias, and gate potential on the TCL/TC generators are discussed. PMID:26696049

  8. Measuring Thermal Diffusivity Of A High-Tc Superconductor

    NASA Technical Reports Server (NTRS)

    Powers, Charles E.; Oh, Gloria; Leidecker, Henning

    1992-01-01

    Technique for measuring thermal diffusivity of superconductor of high critical temperature based on Angstrom's temperature-wave method. Peltier junction generates temperature oscillations, which propagate with attenuation up specimen. Thermal diffusivity of specimen calculated from distance between thermocouples and amplitudes and phases of oscillatory components of thermocouple readings.

  9. 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.

  10. Wind Generators

    NASA Technical Reports Server (NTRS)

    1989-01-01

    When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.

  11. Tc-99m glucoheptonate estimation of glomerular filtration rate. Correlation with endogenous creatinine clearance

    SciTech Connect

    Long, S.E.; Thompson, W.L.; Sonnemaker, R.E.; Pounds, B.K.; Burdine, J.A.

    1984-05-01

    Estimation of glomerular filtration rate (GFR) using radioisotope techniques has been successfully accomplished with I-125 iothalamate, Cr-51 EDTA, and Tc-99m DTPA. However, the techniques have required up to several hours to complete with blood and/or urine sampling. A method introduced by Schlegel and modified by Gates provides a simple and rapid technique of GFR quantitation that obviates the need for blood and urine sampling. In the present study an evaluation of Tc-99m GHA was undertaken to assess its ability to reflect GRF using a modification of Gates technique. When the GFR determinations were compared with a current 24-hour CrC1, a correlation coefficient of 0.91 was obtained. Tc-99m GHA-derived GFR appears to closely correlate with endogenous CrC1 over a wide range of renal function.

  12. Critical Exponents and Pressure Dependence of Tc of La(Ca)MnO3

    NASA Astrophysics Data System (ADS)

    Souza, Jose A.; White, B. D.; Neumeier, J. J.; Yu, Y.-K.; Dos Santos, C. A. M.

    2007-03-01

    Measurements of heat capacity and thermal expansion for La1- xCaxMnO3 with x = 0, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, and 1 are reported. Using a model proposed previously (Souza et al. Phys. Rev. Lett. 94, 207209 (2005)), which utilizes both heat capacity (CP) and thermal expansion coefficient (?) data, the pressure dependencies of Tc, dTc/dP, are obtained for all samples. dTc/dP decreases as the Ca doping increases. Critical behavior using both CP and ? is evaluated for the samples. The critical exponent ? increases from 0.13, for LaMnO3 to 0.97 for x = 0.30. As Ca content is increased further, ? drops reaching 0.11, for CaMnO3.

  13. Antiferromagnetic Order as the Competing Ground State in electron-doped high-Tc superconductors

    NASA Astrophysics Data System (ADS)

    Dai, Pengcheng

    2004-03-01

    Superconductivity in the high-transition-temperature (high-T_c) copper oxides competes with other possible ground states. The physical explanation for superconductivity can be constrained by determining the nature of the closest competing ground state, and establishing if that state is universal among all high-Tc materials. Antiferromagnetism has been theoretically predicted to be the competing ground state. A competing ground state is revealed when superconductivity is destroyed by the application of a magnetic field, and antiferromagnetism has been observed in hole-doped materials under the influence of modest fields. Here we report the results of transport and neutron-scattering experiments on several electron-doped high-Tc superconductors. The applied field reveals a static, commensurate, anomalously conducting long-range order antiferromagnetic state. This and previous experiments on the hole-doped materials therefore establishes antiferromagnetic order as the competing ground state in high-Tc copper oxides materials, irrespective of electron or hole-doping.

  14. Bone accumulation of the Tc-99m complex of carbamyl phosphate and its analogs.

    PubMed

    Hosain, P; Spencer, R P; Ahlquist, K J; Sripada, P K

    1978-05-01

    Carbamyl phosphate, an organic molecule containing a single phosphate group, has been used in the therapy of sickle-cell disease. Carbamyl phosphate bound Tc-99m and achieved bone uptake in mice, rabbits, and a human volunteer. By examination of the structural formula, a working hypothesis was developed that predicted that the Tc-99m complexes of the analogous compounds acetyl phosphate, propionyl phosphate, and butyryl phosphate, each carrying single phosphate and carbonyl groups, would also show bone specificity. This was confirmed experimentally. Phosphonoacetic acid is a structural analog of these compounds. The structural analysis also predicted that aminomethylphosphonic acid and phosphoenolpyruvate would not have as avid bone affinity, and this was also confirmed. These compounds represent a new class of bone-seeking agents that have the common properties of a lone phosphate and a carbonyl function. Such agents may permit the synthesis of additional analogs in an effort to obtain optimal affinity in the Tc-99m complexes. PMID:641577

  15. 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.

  16. Stannous glucoheptonate: An effective tinning agent for Tc-99m labeling of blood cells

    SciTech Connect

    Straub, R.F.; Meinken, G.E.; Srivastava, S.C.

    1986-01-01

    Of the various tin compounds studied, stannous glucoheptonate proved to be the most effective tinning agent for labelling blood cells with technetium 99. Much less tin was needed to achieve a rapid and satisfactory intracellular Sn(II) content. Less Sn(II) remained extracellular, facilitating its removal by oxidation or washing. Highest /sup 99m/Tc-labeling efficiencies are obtained for RBC, leukocytes, and platelets. Label stability in vitro was higher (2 to 3% washout from /sup 99m/Tc-RBC, and approx. 10% from /sup 99m/Tc-leukocytes and platelets, upon prolonged incubation with saline or plasma). The order of effectiveness for the tinning agents tested is glucoheptonate > citrate >> DTPA > PYP. 4 refs., 6 figs.

  17. 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%.

  18. Tc(VII) Reduction Kinetics by Titanomagnetite (Fe3-xTixO4) Nanoparticles

    SciTech Connect

    Liu, Juan; Pearce, Carolyn I.; Qafoku, Odeta; Arenholz, Elke; Heald, Steve M.; Rosso, Kevin M.

    2012-09-01

    Technetium contamination remains a major environmental problem at nuclear reprocessing sites, such as at the Hanford nuclear reservation, Washington, U.S.A. Here we investigate the heterogeneous reduction of the highly soluble pertechnetate anion [Tc(VII)O4-] to sparingly soluble Tc(IV)-bearing solids by a novel and well-characterized set of mixed-valent titanium-doped magnetite nanoparticles, structurally and chemically analogous to titanomagnetites naturally present in Hanford sediments. Titanomagnetite (Fe3 xTixO4) nanoparticles (10-12 nm) with varying Ti content (0 ? x ? 0.53) were synthesized in aqueous suspension. Reaction with 10 and 30 ?M Tc(VII) solution yielded fast exponentially decaying reduction kinetics with rates that increased with increasing solid-state Fe(II)/Fe(III) ratio in the nanoparticles, a characteristic systematically controlled by the Ti-content. Nanoparticles before and after reduction experiments and surface-associated products of Tc(VII) reduction were characterized using transmission electron microscopy (TEM), X-ray absorption nearedge spectroscopy (XANES), extended X-ray absorption fine structure spectroscopy (EXAFS), micro Xray diffraction (?-XRD), X-ray absorption (XA) and X-ray magnetic circular dichroism (XMCD). A mechanistic reaction model was developed involving reduction of Tc(VII) to form Tc(IV)/Fe(III) solids by structural Fe(II) enriched at the nanoparticle surface, a reactive Fe(II) pool that during reaction is resupplied and sustained by outward migration of Fe(II) from the particle interior with concurrent inward migration of charge-balancing cationic vacancies in a ratio of 3:1. The reaction process was quantitatively linked to mass and electron balanced changes in the Fe3-xTixO4 nanoparticles, and the accessibility of structural Fe(II) from these phases was determined.

  19. 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

  20. Tc(VII) reduction kinetics by titanomagnetite (Fe3-xTixO4) nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, J.; Pearce, C. I.; Qafoku, O.; Arenholz, E.; Heald, S. M.; Rosso, K. M.

    2012-09-01

    Technetium contamination remains a major environmental problem at nuclear reprocessing sites, such as at the Hanford nuclear reservation, Washington, USA. Here we investigate the heterogeneous reduction of the highly soluble pertechnetate anion [Tc(VII)O4-] to sparingly soluble Tc(IV)-bearing solids by a novel and well-characterized set of mixed-valent titanium-doped magnetite nanoparticles, structurally and chemically analogous to titanomagnetites naturally present in Hanford sediments. Titanomagnetite (Fe3-xTixO4) nanoparticles (10-12 nm) with varying Ti content (0 ? x ? 0.53) were synthesized in aqueous suspension. Reaction with 10 and 30 ?M Tc(VII) solution yielded fast exponentially decaying reduction kinetics with rates that increased with increasing solid-state Fe(II)/Fe(III) ratio in the nanoparticles, a characteristic systematically controlled by the Ti-content. Nanoparticles before and after reduction experiments and surface-associated products of Tc(VII) reduction were characterized using transmission electron microscopy (TEM), X-ray absorption near-edge spectroscopy (XANES), extended X-ray absorption fine structure spectroscopy (EXAFS), micro X-ray diffraction (?-XRD), X-ray absorption (XA) and X-ray magnetic circular dichroism (XMCD). A mechanistic reaction model was developed involving reduction of Tc(VII) to form Tc(IV)/Fe(III) solids by structural Fe(II) enriched at the nanoparticle surface, a reactive Fe(II) pool that during reaction is resupplied and sustained by outward migration of Fe(II) from the particle interior with concurrent inward migration of charge-balancing cationic vacancies in a ratio of 3:1. The reaction process was quantitatively linked to mass and electron balanced changes in the Fe3-xTixO4 nanoparticles, and the accessibility of structural Fe(II) from these phases was determined.

  1. 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.

  2. Renal accumulation of /sup 99m/Tc-DMSA in the artificially perfused isolated rat kidney

    SciTech Connect

    Goldraich, N.P.; Alvarenga, A.R.; Goldraich, I.H.; Ramos, O.L.; Sigulem, D.

    1985-12-01

    In order to investigate aspects of the renal handling of /sup 99m/Tc-DMSA, 68 isolated rat kidneys were artificially perfused. The experimental groups were: Group 1 (no. = 32)-oxygenated filtering kidneys; Group 2 (no. = 29)-oxygenated non-filtering kidneys; Group 3 (no. = 7)-anaerobic non-filtering kidneys. The authors conclude that the /sup 99m/Tc-DMSA complex is strongly bound to albumin, is not filtered and is removed from perfusion fluid through the renal peritubular capillary route and that this occurs by an active process which depends upon aerobic metabolism. This process has a high capacity and is not inhibited by probenecid.

  3. Tank 16 Annulus Cleanout Analysis Doses at Seepline from Transport of Residual Tc-99 Wastes

    SciTech Connect

    Collard, L.B.

    1999-03-31

    An analysis of residual Tc-99 in the Tank 16 annulus was conducted to assess the potential benefit from cleaning the annulus. One analysis was performed for the as-is case to determine seepline doses if no clean out occurs. Another analysis was performed assuming that ninety percent of existing contaminants are removed. Characterization data for samples retrieved from the annulus were used in the analysis. Only Tc-99 was analyzed because preliminary modeling identified it as the highest dose contributor. The effect of residual waste in piping was not analyzed.

  4. Chiral symmetry breaking and confinement effects on dilepton and photon production around Tc

    NASA Astrophysics Data System (ADS)

    Satow, Daisuke; Weise, Wolfram

    2015-09-01

    Production rates of dileptons and photons from the quark-gluon (QGP) phase are calculated taking into account effects of confinement and spontaneous chiral symmetry breaking (? SB ) not far from the transition temperature Tc. We find that the production rates of dileptons with large momenta and of photons originating from the QGP around Tc are suppressed by the ? SB effect. We also discuss to what extent information about details of the chiral transition, such as its characteristic temperature range and the steepness of the crossover, are reflected in these quantities.

  5. Magnetic study in high-Tc superconducting oxides by AC-complex magnetic susceptibility

    NASA Astrophysics Data System (ADS)

    Okuda, K.; Noguchi, S.; Yoshikawa, M.; Imanaka, N.; Imai, H.; Adachi, G.

    1990-08-01

    Magnetic properties of high-Tc superconducting oxides were investigated by ac-complex magnetic susceptibility ? = ?? - j?. The magnetic penetration depth ?(T) obtained f om ?? was analyzed by the term of BCS gap parameter. A strong correlation between Tc and ?(O) -2 was found. The loss peak of ??(T) in the bulk sample of Bi(Pb)SrCaCuO-Au composites system was measured as a function of field amplitude and frequency. The activation energy of flux was obtained as a function of field amplitude by applying the flux-creep model.

  6. Preliminary dosimetry investigation of Tc-99m diagnostic radionuclide by NIPAM gel dosimeter

    NASA Astrophysics Data System (ADS)

    Huang, You-Ruei; Chang, Yuan-Jen; Hsieh, Ling-Ling; Yu, Bi-Wei; Chu, Chien-Hau; Hsieh, Bor-Tsung

    2013-06-01

    The N-isopropylacrylamide (NIPAM) gel dosimeter was investigated as a suitable material for measuring absorbed doses from radionuclide sources. In this study, NIPAM gel dosimeter was used to evaluate the dose distributions of the Tc-99m radionuclide in NIPAM gel. The accumulated radioactivity range of the Tc-99m NIPAM gel is from approximately 0 MBq to 13.6 MBq (about 0.37 mCi). The NIPAM gel dosimeter with high stability and high-dose linear and non-energy dependent properties can provide various radiopharmaceutical activity intensities in the conduct of dose assessment in nuclear medicine, thereby producing the most promising dose verification tools.

  7. Extrarenal abnormalities in Tc-99m-DTPA renal blood flow studies

    SciTech Connect

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

    1985-01-01

    The authors observed extrarenal abnormalities during renal flow scintigraphy and retrospectively reviewed 90 patient studies to determine the types and frequencies of such abnormal findings. For each routine Tc-99m-DTPA renal flow study, they obtained nine 2-second sequential images, which included the heart, abdominal aorta, spleen and kidneys. Eighty abnormalities, observed in 62 patients, were divided into three categories: aortic, 37 cases; splenic, 40 cases; and miscellaneous, 3 cases. Other correlative studies including Tc-99m sulfur colloid-spleen scintigraphy, ultrasonography (US), CT, aortography, and surgical and/or autopsy findings were available for corroboration in 56 of 80 lesions.

  8. Nonintrusive photoacoustic characterization of critical properties in high Tc superconducting materials. Phase 1

    SciTech Connect

    Sarrafzadeh, A.D.

    1990-09-29

    The objective of the project includes the use of noncontacting laser-based photoacoustic measurement as a means of accurate, non-intrusive measurement of the electronic, vibrational, and optical properties of new high Tc superconducting materials. The non-intrusive measurement instrumentation is integrated for both continuous modulation and pulsed photoacoustic signal (PAS) measurements associated with bulk superconducting plate samples of rough and opaque surfaces. The overall results, the methods evaluated, and the experimental observations presented show that the laboratory proof-of-concept laser-based instrument can provide photoacoustic-related properties of high Tc superconducting materials using innovative fiberoptic/acoustic detection technology.

  9. [Differential expression of DTSsa4 Tc1-like transposons in closely related populations of Baikal ciscoes].

    PubMed

    Bychenko, O S; Sukhanova, L V; Azhikina, T L; Sverdlov, E D

    2009-01-01

    Two representatives of Baikal ciscoes - lake cisco and omul - diverged from a common ancestor as recently as 10-20 thousand years ago. We have found an increasing expression level of DTSsa4 Tc1-like DNA transposons in cisco and omul brains. The mapping of the sequences of these transposons from Salmo salar and Danio rerio genomes has shown that in some cases, these transposons are located in the 5' and 3' regions, as well as in the promoter regions of various genes. Probably, Tc1-like transposons affect the activity of neighboring genes, providing the adaptive divergence of the cisco population. PMID:20208586

  10. Mechanical resonance characteristics of a high-{Tc} superconducting levitation system

    SciTech Connect

    Sugiura, Toshihiko; Fujimori, Hideki

    1996-05-01

    This research deals with dynamic response of a permanent magnet freely levitated above an excited high-{Tc} superconductor. Evaluation of dynamic characteristics is required in mechanical design of high-{Tc} superconducting levitation systems. Their dynamics is coupled with Type-II superconducting phenomena. By a numerical approach based on some macroscopic models they evaluate mechanical resonance characteristics of a superconducting levitation system. Numerical results show some nonlinear properties and effect of the flux flow in Type-II superconductor, which are observed in experiments or predicted by analyses.

  11. Numerical analyses of levitation force and flux creep on high [Tc] superconductor

    SciTech Connect

    Tsuchimoto, M.; Kojima, T.; Takeuchi, H.; Honma, T. . Dept. of Electrical Engineering)

    1993-11-01

    Large levitation force and a stable equilibrium are obtained with a permanent magnet and a bulk high [Tc] superconductor (HTSC). Evaluation of the levitation force is important for many applications, such as magnetically levitated vehicles, magnetic bearing, flywheel and linear drive. Levitation force between a permanent magnet and a high [Tc] superconductor is examined by using two numerical methods. The levitation force to vertical direction is calculated by using the critical state model. Stiffness of restoring force to horizontal direction is calculated by using a frozen-in field model. Numerical solutions agree well with experimental results. Dynamic properties of the levitation force are also analyzed by combining the two methods.

  12. Origin and Dynamical Evolution of Ureilites and 2008TC3/Almahata Sitta.

    NASA Astrophysics Data System (ADS)

    Goodrich, Cyrena

    In October, 2008, a small asteroid with an F-type reflectance spectrum, 2008 TC3, exploded over the Nubian desert and deposited material in a strewn field in Northern Sudan. Searches to-date have led to collection of >600 stones thought to be derived from 2008 TC3. These materials are named Almahata Sitta (AHS), and represent the first recovered meteorite from a spectrally observed asteroid. The discovery, tracking, spectral analysis and recovery of material from 2008 TC3/AHS was a remarkable series of events, and a testament to the benefits of cross-disciplinary and international cooperation. But the list of remarkable things about this object does not end there. The first AHS samples studied showed an anomalous type of material belonging to the class of ureilite meterorites. Ureilites are one of the least understood classes of primitive achondrites, and arguably one of the most important for understanding early solar system processes that bridge the chondrite-to-achondrite transition. Thus, the advent of a new type of ureilite, potentially providing new information in the form of fresh, unweathered material, is certainly welcome. Ensuing studies of more samples showed a great diversity of ureilite materials, leading to classification of AHS as an anomalous polymict ureilite. Even more remarkably, however, ~20-30% of the recovered clasts were found to be non- ureilitic, instead representing a variety of different chondrite types. Thus, 2008 TC3/AHS appears to be a new type of breccia, unlike any meteorite known to date. Nevertheless, there are strong indications that 2008 TC3/AHS, "normal" polymict ureilites, and main group ureilites share a common lineage. We hypothesize that the immediate parent of 2008 TC3/AHS was also the immediate parent of all ureilitic material that has been sampled in recent times by meteorites on Earth, and that using 2008 TC3/AHS as a starting point, we can trace the history of this material back through many stages of Solar System history to accretion of the original ureilite parent body. The goal of the proposed research is to bring our combined expertise in ureilite petrology and geochemistry, accretion modeling, asteroid dynamics, and cratering and regolith evolution to bear on 4 major stages in the history of ureilitic material in the Solar System: 1) accretion and early differentiation; 2) parent body breakup and formation of offspring bodies; 3) dynamical evolution of ureilitic asteroids; and 4) development of a complex regolith on the 2008 TC3 parent.

  13. Generative Semantics.

    ERIC Educational Resources Information Center

    King, Margaret

    The first section of this paper deals with the attempts within the framework of transformational grammar to make semantics a systematic part of linguistic description, and outlines the characteristics of the generative semantics position. The second section takes a critical look at generative semantics in its later manifestations, and makes a case…

  14. Generative Semantics

    ERIC Educational Resources Information Center

    Bagha, Karim Nazari

    2011-01-01

    Generative semantics is (or perhaps was) a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of…

  15. Piezoelectrostatic Generator

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1989-01-01

    High voltage generated by compact, lightweight equipment. Improved variable-capacitance electrostatic generator relies on piezoelectric effort to convert mechanical energy directly into electrical energy and contains neither transformers nor bulky high-voltage rectifiers. Requires neither external power supply to charge, nor vacuum to insulate electrodes.

  16. Manipulating attentional load in sequence learning through random number generation.

    PubMed

    Wierzcho?, Micha?; Gaillard, Vinciane; Asanowicz, Dariusz; Cleeremans, Axel

    2012-01-01

    Implicit learning is often assumed to be an effortless process. However, some artificial grammar learning and sequence learning studies using dual tasks seem to suggest that attention is essential for implicit learning to occur. This discrepancy probably results from the specific type of secondary task that is used. Different secondary tasks may engage attentional resources differently and therefore may bias performance on the primary task in different ways. Here, we used a random number generation (RNG) task, which may allow for a closer monitoring of a participant's engagement in a secondary task than the popular secondary task in sequence learning studies: tone counting (TC). In the first two experiments, we investigated the interference associated with performing RNG concurrently with a serial reaction time (SRT) task. In a third experiment, we compared the effects of RNG and TC. In all three experiments, we directly evaluated participants' knowledge of the sequence with a subsequent sequence generation task. Sequence learning was consistently observed in all experiments, but was impaired under dual-task conditions. Most importantly, our data suggest that RNG is more demanding and impairs learning to a greater extent than TC. Nevertheless, we failed to observe effects of the secondary task in subsequent sequence generation. Our studies indicate that RNG is a promising task to explore the involvement of attention in the SRT task. PMID:22723816

  17. Institute of Computer Science IV, University of Bonn, Germany IPonAir Next Generation Wireless Routing

    E-print Network

    Clausen, Michael

    Institute of Computer Science IV, University of Bonn, Germany IPonAir ­ Next Generation Wireless Project homepage: http://www.iponair.de/ Institute of Computer Science IV, University of Bonn, Germany, Germany Nokia IPonAir Activities: Topics Link Stability Route Stability Cooperative TC algorithm

  18. Rhenium and technetium tricarbonyl, {M(CO)3} (+) (M = Tc, Re), binding to mammalian metallothioneins: new insights into chemical and radiopharmaceutical implications.

    PubMed

    Lecina, Joan; Palacios, Òscar; Atrian, Sílvia; Capdevila, Mercè; Suades, Joan

    2015-04-01

    This paper deals with the binding of the four mammalian metallothioneins (MTs) to the organometallic metal fragment {fac-M(CO)3}(+) (M = (99)Tc, Re), which is highly promising for the preparation of second-generation radiopharmaceuticals. The study of the transmetallation reaction between zinc and rhenium in Zn7-MT1 by means of UV-vis and CD spectroscopy demonstrated the incorporation of the {fac-Re(CO)3}(+) fragment to the MTs. This reaction should be performed at 70 °C to accelerate the reaction rate, a result that is consistent with the reported reactivity of the rhenium fragment. ESI-TOF MS demonstrated the formation of mixed-metal species as Zn6,{Re(CO)3}-MT, Zn6,{Re(CO)3}2-MT, and Zn5,{Re(CO)3}3-MT, as well as the different reactivity of the four MT isoforms. Hence, Zn-MT3 showed the highest reactivity, in agreement with its high Cu-thionein character, whereas Zn-MT2 exhibited the lowest reactivity, in line with its high Zn-thionein character. The reactivity of the Zn-loaded forms of MT1 and MT4 is intermediate between those of MT3 and MT2. The study of the binding of the {fac-(99)Tc(CO)3}(+) fragment to MTs showed a significant and very interesting different reactivity in relation to rhenium. The transmetallation reaction is much more effective with technetium than with rhenium and significant amounts of mixed Zn x ,{(99)Tc(CO)3} y -MT species were formed with the four MT isoforms whereas only MT3 rendered similar amounts of rhenium derivatives. The results obtained in this study support the possible use of technetium for labelling mammalian metallothioneins and also for possible radiopharmaceutical applications. PMID:25511253

  19. 78 FR 30269 - Foreign-Trade Zone 129-Bellingham, Washington; Authorization of Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... 400), including notice in the Federal Register inviting ] public comment (78 FR 7395, 02/01/2013). The...; T.C. Trading Company, Inc. (Eyeglass Assembly and Kitting), Blaine, WA On January 17, 2013, the Port... Foreign-Trade Zones (FTZ) Board on behalf of T.C. Trading Company, Inc., within Subzone 129B, in...

  20. Development of Tyrosine-Based Radiotracer 99mTc-N4-Tyrosine for Breast Cancer Imaging

    PubMed Central

    Kong, Fan-Lin; Ali, Mohammad S.; Rollo, Alex; Smith, Daniel L.; Zhang, Yinhan; Yu, Dong-Fang; Yang, David J.

    2012-01-01

    The purpose of this study was to develop an efficient way to synthesize 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]-tyrosine (99mTc-N4-Tyrosine), a novel amino acid-based radiotracer, and evaluate its potential in breast cancer gamma imaging. Precursor N4-Tyrosine was synthesized using a 5-step procedure, and its total synthesis yield was 38%. It was successfully labeled with 99mTc with high radiochemical purity (>95%). Cellular uptake of 99mTc-N4-Tyrosine was much higher than that of 99mTc-N4 and the clinical gold standard 18F-2-deoxy-2-fluoro-glucose (18F-FDG) in rat breast tumor cells in vitro. Tissue uptake and dosimetry estimation in normal rats revealed that 99mTc-N4-Tyrosine could be safely administered to humans. Evaluation in breast tumor-bearing rats showed that although 99mTc-N4-Tyrosine appeared to be inferior to 18F-FDG in distinguishing breast tumor tissue from chemical-induced inflammatory tissue, it had high tumor-to-muscle uptake ratios and could detect breast tumors clearly by planar scintigraphic imaging. 99mTc-N4-Tyrosine could thus be a useful radiotracer for use in breast tumor diagnostic imaging. PMID:22496612

  1. Synthesis and Evaluation of Amino Acid-Based Radiotracer 99mTc-N4-AMT for Breast Cancer Imaging

    PubMed Central

    Kong, Fan-Lin; Ali, Mohammad S.; Zhang, Yinhan; Oh, Chang-Sok; Yu, Dong-Fang; Chanda, Mithu; Yang, David J.

    2011-01-01

    Purpose. This study was to develop an efficient synthesis of 99mTc-O-[3-(1,4,8,11-tetraazabicyclohexadecane)-propyl]-?-methyl tyrosine (99mTc-N4-AMT) and evaluate its potential in cancer imaging. Methods. N4-AMT was synthesized by reacting N4-oxalate and 3-bromopropyl AMT (N-BOC, ethyl ester). In vitro cellular uptake kinetics of 99mTc-N4-AMT was assessed in rat mammary tumor cells. Tissue distribution of the radiotracer was determined in normal rats at 0.5–4?h, while planar imaging was performed in mammary tumor-bearing rats at 30–120 min. Results. The total synthesis yield of N4-AMT was 14%. Cellular uptake of 99mTc-N4-AMT was significantly higher than that of 99mTc-N4. Planar imaging revealed that 99mTc-N4-AMT rendered greater tumor/muscle ratios than 99mTc-N4. Conclusions. N4-AMT could be synthesized with a considerably high yield. Our in vitro and in vivo data suggest that 99mTc-N4-AMT, a novel amino acid-based radiotracer, efficiently enters breast cancer cells, effectively distinguishes mammary tumors from normal tissues, and thus holds the promise for breast cancer imaging. PMID:21541217

  2. A Lipid-modified Phosphoinositide-specific Phospholipase C (TcPI-PLC) Is Involved in Differentiation of Trypomastigotes to

    E-print Network

    Singer, Randall

    A Lipid-modified Phosphoinositide-specific Phospholipase C (TcPI-PLC) Is Involved C (PI- PLC) is an important component of the inositol phos- phate/diacylglycerol signaling pathway. A newly discov- ered Trypanosoma cruzi PI-PLC (TcPI-PLC) is lipid modified in its N terminus, targeted

  3. Identification of proteins important for tetracycline (TC) binding to ribosomes by single protein omission reconstitution (SPORE) experiments

    SciTech Connect

    Buck, M.; Cooperman, B.S.

    1987-05-01

    TC inhibits protein synthesis in E. coli by interfering with aminoacyl-tRNA binding to the ribosomal A site, and there is strong evidence that such inhibition results from TC binding to a high affinity site on the 30S subunit. The SPORE approach has been used to define those 30S proteins that are potentially important for high affinity TC binding, measured as the (/sup 3/H)-TC co-sedimenting with the reconstitution particle through a sucrose density gradient. Reverse phase-HPLC has been used both to prepare ribosomal proteins and to analyze the protein content of reconstituted particles. The results obtained so far show that protein S7, as well as some proteins linked to S7 in the 30S assembly map, are important for TC binding, whereas other ribosomal proteins are not. These results are in very good accord with their earlier photoaffinity labeling studies that strongly implicated S7 as forming part of the TC binding site. Interestingly, protein S18, which is photolabeled by TC to a high extent but in a non-site specific manner, appears to be unimportant for TC binding.

  4. Surface expression of CD3 in the absence of T cell receptor (TcR): evidence for sorting of partial TcR/CD3 complexes in a post-endoplasmic reticulum compartment.

    PubMed

    Ley, S C; Tan, K N; Kubo, R; Sy, M S; Terhorst, C

    1989-12-01

    The T cell receptor (TcR) for antigen, on the majority of T cells, is a disulfide-linked heterodimer composed of the alpha and beta chains, noncovalently associated with the CD3 complex of polypeptides (gamma, delta, epsilon and zeta). In this report, two murine thymoma cell lines are described which synthesized incomplete TcR/CD3 complexes and expressed low levels of CD3 on their surface in the absence of the TcR chains. The partial TcR/CD3 complexes were composed primarily of the inherently metabolically stable CD3 gamma and epsilon subunits. These results were in contrast to previous studies, which suggested that synthesis of all of the component chains of the TcR/CD3 complex is required for the successful transport of any of the chains to the cell surface. The efficiency of transport of the partial TcR/CD3 complexes from the endoplasmic reticulum (ER) to medial Golgi in the two thymomas was similar to complete complexes. However, the transport of the incomplete receptors was impaired at some point between the medial Golgi and the plasma membrane. Taken together with previous studies, these results suggested that T cells have mechanisms to retain partial TcR/CD3 complexes intracellularly both in the ER and in an undefined post-ER compartment. However, the transport of low levels of partial TcR/CD3 complexes to the cell surface in some T cell lines implied that the retention mechanisms may not always be completely efficient. Cross-linking of the surface, partial TcR/CD3 complexes with anti-CD3 epsilon antibodies did not stimulate interleukin 2 (IL 2) production. It is possible, however, that the partial TcR/CD3 complexes have some function which is unrelated to the stimulation of IL 2 production. PMID:2532601

  5. {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.; Yoshinaga, K.; Sumikama, T.; Miyashita, Y.; Chiba, J.; Nakano, T.; Sugimoto, K.; Takano, S.; Tachibana, T.; Yamaguchi, K.; Odahara, A.

    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.

  6. 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.

  7. NextGenerationSequencing A TCG A G A C G A G A G A T G C A

    E-print Network

    Manstein, Dietmar J.

    RCU NextGenerationSequencing A TCG A G A C G A G A G A T G C A TC C GT C AT C C T G C A T GA A G A G G GT ATC CT C T G AA TAG AAGA G GT T CTC T T RCU NextGenerationSequencing A TCG A G A C G A G A G A T G C A TC C GT C AT C C T G C A T GA A G A G G GT ATC CT C T G AA TAG AAGA G GT T CTC T T A TCG A G

  8. Strain effect on the Néel temperature of SrTcO3 from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Lan; Dai, Cheng-Min; Chen, Gao-Yuan; Chen, Da; Zang, Tao-Cheng; Ge, Li-Juan; Zhou, Wei; Zhu, Yan

    2015-10-01

    Generalized gradient approximation with on-site Coulomb corrections (GGA+U) method is used to investigate the effect of biaxial strain on the Néel temperature of SrTcO3. A series of hypothetical strains on SrTcO3 are considered to simulate its being applied in SrTcO3-based devices. It is found that a tensile strain will decrease TN, while a compressive strain less than 6.6% will increase TN. At a compressive strain between 5.5% and 6.7%, a highest TN which is about 26.6% higher than that of the bulk material can be obtained. The higher TN can be experimentally achieved by growing SrTcO3 on the common substrate STO/LSAT/NGO/LAO. Our work provides a theoretical basis for the application of high-TN SrTcO3 in small devices.

  9. Migrating data from TcSE to DOORS : an evaluation of the T-Plan Integrator software application.

    SciTech Connect

    Post, Debra S.; Manzanares, David A.; Taylor, Jeffrey L.

    2011-02-01

    This report describes our evaluation of the T-Plan Integrator software application as it was used to transfer a real data set from the Teamcenter for Systems Engineering (TcSE) software application to the DOORS software application. The T-Plan Integrator was evaluated to determine if it would meet the needs of Sandia National Laboratories to migrate our existing data sets from TcSE to DOORS. This report presents the struggles of migrating data and focuses on how the Integrator can be used to map a data set and its data architecture from TcSE to DOORS. Finally, this report describes how the bulk of the migration can take place using the Integrator; however, about 20-30% of the data would need to be transferred from TcSE to DOORS manually. This report does not evaluate the transfer of data from DOORS to TcSE.

  10. Generalized London free energy for high-Tc vortex lattices Ian Affleck

    E-print Network

    Franz, Marcel

    Generalized London free energy for high-Tc vortex lattices Ian Affleck Department of Physics-1829 97 50402-4 The London free energy provides a very simple way of studying the vortex lattice that this effect can arise from additional quartic derivative terms in the Ginzburg-Landau GL free energy4­7 or

  11. Tc-99m antifibrin Fab' fragments for imaging venous thrombi: Evaluation in a canine model

    SciTech Connect

    Knight, L.C.; Maurer, A.H.; Ammar, I.A.; Epps, L.A.; Dean, R.T.; Pak, K.Y.; Berger, H.J. )

    1989-10-01

    An antifibrin antibody (T2G1s) Fab' fragment labeled with technetium-99m was tested for its ability to produce images of fresh thrombi in dogs. In gamma camera images, all thrombi were evident by 2-4 hours after injection. Mean thrombus-to-blood and thrombus-to-muscle ratios averaged 4.0 and 69 at four hours after injection and increased to 24 and 270, respectively, by 24 hours after injection. When compared with I-125 fibrinogen injected into the same dogs, Tc-99m-antifibrin Fab' had lower absolute uptake in thrombus but higher thrombus-to-blood ratios due to a faster rate of disappearance from the blood. The primary route of excretion was through the kidneys. Tc-99m-antifibrin Fab' was highly stable in vivo, with an average of 82% of the circulating radioactivity able to bind to fibrin at 4 hours after injection. When compared with an In-111-labeled Fab fragment of antifibrin antibody 59D8, thrombus-to-blood and thrombus-to-muscle ratios were slightly higher for the Tc-99m-labeled antibody, and the blood disappearance rate was slightly faster. The absolute uptake in thrombus, however, was not significantly different, and the thrombus was visualized at about the same time after injection. These studies suggest that Tc-99m T2G1s Fab' is a potential agent for detecting thrombi in a clinical setting.

  12. Modification of both d33 and TC in a potassium-sodium niobate ternary system.

    PubMed

    Wu, Bo; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo

    2015-12-28

    In this work, we simultaneously achieved a giant d33 and a high TC in a lead-free piezoelectric ternary system of (1 -x-y)K0.48Na0.52NbO3-xBiFeO3-yBi0.5Na0.5ZrO3 {(1 -x-y)KNN-xBF-yBNZ}. Owing to the rhombohedral-orthorhombic-tetragonal (R-O-T) phase coexistence and the enhanced dielectric and ferroelectric properties, the ceramics with a composition of (x = 0.006, y = 0.04) show a giant d33 of ?428 pC N(-1) together with a TC of ?318 °C, thereby proving that the design of ternary systems is an effective way to achieve both high d33 and high TC in KNN-based materials. In addition, a good thermal stability for piezoelectricity was also observed in these ceramics (e.g., d33 > 390 pC N(-1), T ? 300 °C). This is the first time such a good comprehensive performance in potassium-sodium niobate materials has been obtained. As a result, we believe that this type of material system with both giant d33 and high TC is a promising candidate for high-temperature piezoelectric devices. PMID:26598931

  13. Tc-99m colloid lung uptake in a rare case of toxoplasmosis with liver involvement

    SciTech Connect

    Garty, I.; Tal, I.; Kaynan, A.

    1984-06-01

    Intensive lung accumulation of colloid (Tc-99m phytate) was demonstrated in a child suffering from acquired toxoplasmosis with a rare manifestation of severe liver damage. The possible mechanism and clinical importance of colloid lung concentration in this case is briefly discussed, including a review of the literature on this subject.

  14. Uptake of 99mTc-DTPA in Bone Metastases from Renal Cancer.

    PubMed

    Wang, Taisong; Zhao, Jinhua; Xing, Yan

    2015-10-01

    A 67-year-old man with left renal cell carcinoma underwent Tc-DTPA renal scintigraphy to evaluate the kidney function. The images incidentally identified a large focus of abnormal activity in the right pelvic region, which corresponded to the site of metastasis in the right ilium revealed on CT image. PMID:26018713

  15. Magnetic Microscopy and Imaging II Taras Pokhil , Chairman Determination of Tc , vortex creation and vortex imaging

    E-print Network

    Grütter, Peter

    have also imaged vortices as a function of applied magnetic field, and have observed the expected of superconducting samples. Several groups have re- ported work in the literature on both high-Tc and conven- tional by magnetron sputtering onto a silicon substrate. Two commercially avail- able silicon nitride cantilevers were

  16. Effect of ketamine, pentobarbital, and morphine on Tc-99m-DISIDA hepatobiliary kinetics

    SciTech Connect

    Durakovic, A.; Dubois, A.

    1985-05-01

    The purpose of this study was to evaluate hapatobiliary kinetics of Tc-99m-DISIDA in dogs after administration of anesthetic sedative or narcotic agents. Four groups of six male Beagle dogs were studied as a non-treated control group and after parenteral administration of ketamine (30 mg/kg IM), pentobarbital (25 mg/kg IV) or morphine (1 mg/kg IV). Each animal was injected with 4 mCi Tc-99m-DISIDA and hepatobiliary scintigraphic studies were obtained using a gamma camera with parallel hole multipurpose collimator and an A/sup 3/ MDS computer. The authors determined; peak activity of Tc-99m-DISIDA in the liver, visualization and peak activity of gallbladder, and intestinal visualization of Tc-99m-DISIDA. Total bilirubin, LDH, SGOT and SGPT were not modified significantly after any drug compared to control. The results showed that two commonly used anesthetics and sedatives (ketamine and pentobarbital) have dramatic and opposite effects on extrahepatic biliary kinetics. Furthermore, ketamine, but not pentobarbital, significantly accelerates intrahepatic biliary kinetics. Finally, as expected, morphine delayed extrahepatic biliary kinetics. Thus, studies of biliary kinetics should be interpreted with caution when measurements are made after administration of anesthetic, sedative or narcotic agents.

  17. TO: Frank Allgower, VP Technical Activities, CSS FROM: Ljubo Vlacic, Chair, TC on Control Education, CSS

    E-print Network

    Pasik-Duncan, Bozenna

    TO: Frank Allgower, VP Technical Activities, CSS FROM: Ljubo Vlacic, Chair, TC on Control Education and enjoy a full leadership role over it. All the essential decisions will be a team-based while each Deputy in conjunction with the AUCC 2013. Bonnie H Ferri will initiate: · annual invited sessions on control education

  18. 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

  19. 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.

  20. 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

  1. TC-Star: Cross-Language Voice Conversion Revisited David Sundermann1,2

    E-print Network

    Suendermann, David

    V T L T speech V T L S voice conversion speech synthesis text translation speech recognition FigureTC-Star: Cross-Language Voice Conversion Revisited David S¨undermann1,2 , Harald H¨oge1 , Antonio tasks is cross-language voice conver- sion. In the recent second evaluation campaign, five participants

  2. ARTICLE doi:10.1038/nature13015 Mechanism of Tc toxin action revealed in

    E-print Network

    Just, Armin

    into the host4,5 . This damages and ultimately kills the target cells. Tcs with specificity for insects weight of 1.41 MDa--at a resolution of 4.0 A° (Fig. 1a and Supplementary Video 1). The TcA protomer

  3. 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.

  4. Pharmacologic alterations in Tc-99m binding by red blood cells: concise communication

    SciTech Connect

    Lee, H.B.; Wexler, J.P.; Scharf, S.C.; Blaufox, M.D.

    1983-05-01

    The effect of two antihypertensive agents (captopril and prazosin) and of digoxin on the efficiency of Tc-99m binding to RBCs was evaluated in the rat. RBCs were labeled with Tc-99m in vivo in six groups of rats: I-normotensive controls Wistar rat (WR), II-prazosin treated WR, III-spontaneously hypertensive rat (SHR), IV-prazosin-treated SHR, V-digoxin-treated WR, and VI-captopril-treated WR. The percentage of intravascular Tc-99m bound to RBC (%T) and the percentage of injected dose remaining intravascular 5 min after injection (%i.v.) were determined. Mean %T was 94.2, 83.8, 94.9, 86.1, 79.7, and 93.3 for groups I-VI respectively. Mean %I.V. was 96.4, 74.6, 94.9, 79.0, 74.4, and 87.4 for groups I-VI respectively. The findings demonstrate a significant reduction of RBC tagging with Tc-99m in rats treated with prazosin and digoxin but not with captopril. The data suggest a potential interference by patient medication with the performance of blood-pool studies.

  5. IEEE TRANSACTIONS ON COMPUTERS, TC-2011-04-0261 1 A Parallel Neuromorphic Text Recognition

    E-print Network

    Qiu, Qinru

    IEEE TRANSACTIONS ON COMPUTERS, TC-2011-04-0261 1 A Parallel Neuromorphic Text Recognition System intelligence has entered a new era. In this paper, we present a HPC-based context-aware Intelligent Text increases? What is the bottle- neck of current HPC architectures when applied to cogni- tive computing

  6. Single electron effects and Bloch oscillations in high-TC superconductive tunneling junctions

    E-print Network

    and a Rutherford backscattering spectrometer RBS . Transmission electron microscopy TEM show quasihomoepitaxialSingle electron effects and Bloch oscillations in high-TC superconductive tunneling junctions G. A. Alvarez,a X. L. Wang, and S. X. Dou Institute for Superconducting & Electronic Materials, University

  7. MYELOID NEOPLASIA Perturbed hematopoiesis in the Tc1 mouse model of Down syndrome

    E-print Network

    Li, Zhe

    MYELOID NEOPLASIA Perturbed hematopoiesis in the Tc1 mouse model of Down syndrome Kate A. Alford,1 Kingdom Trisomy of human chromosome 21 (Hsa21) results in Down syndrome (DS), a disorder that affects many(14):2928-2937) Introduction Down syndrome (DS) results from trisomy of human chromosome 21 (Hsa21, trisomy 21) and is the most

  8. 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.

  9. Frostbite with rhabdomyolysis and renal failure: radionuclide study. [/sup 99m/Tc

    SciTech Connect

    Rosenthall, L.; Kloiber, R.; Gagnon, R.; Damtew, B.; Lough, J.

    1981-08-01

    There is a growing list of muscle lesions exhibiting concentration of bone-seeking /sup 99m/Tc-labeled phosphate complexes; however, rhabdomyolysis due to cold injury has not been included. We performed a multiradiopharmaceutical study that yielded interesting results on a patient who sustained frostbite injury of the legs that led to rhabdomyolysis and acute renal failure.

  10. Congenital Tracheobiliary Fistula Shown on 99mTc-EHIDA Hepatobiliary Scintigraphy.

    PubMed

    Yuan, Leilei; Yang, Haiming; Yang, Jigang; Ma, Daqing

    2016-02-01

    A 1-year 5-month-old male patient had a history of recurrent cough and pneumonia, which required antibiotics and bronchodilators. CT suggested the possibility of congenital tracheobiliary fistula. However, a diagnosis could not be made based on CT alone. A Tc-EHIDA hepatobiliary scintigraphy was then performed, which led to a definite diagnosis of tracheobiliary fistula. PMID:26447371

  11. Localization of Tc-99m MDP in epiphyseal growth plates of rats

    SciTech Connect

    Christensen, S.B.; Krogsgaard, O.W.

    1981-03-01

    The distribution and localization of Tc-99m methylene diphosphonate (Tc-MDP) in the epiphyseal growth plates of the rat were elucidated by contact and microautoradiography. The uptake of the tracer was found to be especially high in the calcified cartilage bars at the end of the vascular loops. In addition to areas of mineralization, increased uptake was found in the Howship's lacunae on the resorbing surfaces. This labeling corresponded with the fluorescence of tetracycline, which labeled both forming and resorbing surfaces, when given with short labeling interval. Distribution of Tc-MDP did not coincide with new production of collagen, as judged by H-3 proline labeling; nor was the uptake localized within cells with high alkaline phosphatase activity. The affinity of the tracer for the mineral phase was confirmed by decalcification of in vivo labeled sections with EDTA, whic showed loss of radioactivity in contrast to sections incubated in water. By chromatography the activity in the decalcification medium could not be distinguished from that of Tc-MDP.

  12. 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

  13. 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.

  14. 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.

  15. Evaluation of Tc-99m leukocyte scan in the diagnosis of acute appendicitis

    SciTech Connect

    Butler, J.A.; Marcus, C.S.; Henneman, P.L.; Inkelis, S.H.; Wilson, S.E.

    1987-05-01

    A new /sup 99m/Tc Microlite leukocyte scan was performed in 38 patients to assess its value in the diagnosis of acute appendicitis. Autologous leukocytes are labeled with /sup 99m/Tc by inducing phagocytosis of /sup 99m/Tc albumin microcolloid particles. The advantages of this test over the standard indium-111 scan include superior imaging capability, a marked reduction (greater than 75%) in the radiation dose, and performance of the test including labeling, in less than 3 hr. Imaging is performed at 5-90 min postinjection of labeled cells. There were 19 male and 19 female patients with ages ranging from 10 to 80 years, in whom the diagnosis of appendicitis was indeterminate on clinical examination. Of the 13 of the 38 patients (34%) who came to surgery 12 had acute appendicitis. The WBC scan correctly identified 10 of the 12 cases of appendicitis. There were two false-negative studies. In the nonoperative group of 25 patients admitted for observation, 21 studies were reported as negative and four identified other sites of inflammation. All patients with a negative study have remained asymptomatic on follow-up. With a sensitivity of 83% (10/12) and a specificity of 100% (26/26) the /sup 99m/Tc leukocyte scan provides a rapid and highly accurate method for diagnosis of appendicitis in this preliminary study of patients with equivocal clinical exams.

  16. CrowdTC: Crowdsourced Taxonomy Construction Rui Meng, Yongxin Tong, Lei Chen, Caleb Chen Cao

    E-print Network

    Liu, Yunhao

    CrowdTC: Crowdsourced Taxonomy Construction Rui Meng, Yongxin Tong, Lei Chen, Caleb Chen Cao University, China {rmeng,leichen,caochen}@cse.ust.hk yxtong@buaa.edu.cn Abstract--Recently, taxonomy has-based approaches and human computation (the crowd) to construct a more complete and accurate taxonomy. Specifically

  17. CrowdTC: Crowdsourced Taxonomy Construction Rui Meng, Yongxin Tong, Lei Chen, Caleb Chen Cao

    E-print Network

    Liu, Yunhao

    CrowdTC: Crowdsourced Taxonomy Construction Rui Meng, Yongxin Tong, Lei Chen, Caleb Chen Cao University, China {rmeng,leichen,caochen}@cse.ust.hk yxtong@buaa.edu.cn Abstract--Taxonomy, which is widely. Clearly, the automatic methods for taxonomy acquisition have the advantage of good scalability and high

  18. Green functions in t-J model of high-[Tc] superconductivity

    SciTech Connect

    Nguyen, V.H. )

    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.

  19. (He-3,d) Reaction to Bound and Quasibound Levels in Tc-93 

    E-print Network

    Kozub, R. L.; Youngblood, David H.

    1971-01-01

    , 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 University, College Station, Texas...

  20. 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

  1. Liquid scintillation counting methodology for (99)Tc analysis: a remedy for radiopharmaceutical waste.

    PubMed

    Khan, Mumtaz; Um, Wooyong

    2015-09-01

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 ((99g)Tc) analysis with significant savings in analysis cost and time. The method was developed to quantify (99g)Tc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11?900 ppm total dissolved solids. The resultant quench curve proved to be effective for quantifying spiked (99g)Tc activity in deionized water, tap water, groundwater, seawater, and urine samples. Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked (99g)Tc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A preconcentration factor of 1000 was achieved at 100 °C for 100% chemical recovery. PMID:26270580

  2. Proceedings Generation,

    E-print Network

    Kan, Min-Yen

    way of helping a user discriminate between several documents returned by a search engine. Traditional on the healthcare topic of ``Angina''. The generated in­ dicative summary in the bottom half categorizes documents

  3. 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)

  4. Understanding the in vivo uptake kinetics of a phosphatidylethanolamine-binding agent 99mTc-Duramycin

    PubMed Central

    Audi, Said; Li, Zhixin; Capacete, Joseph; Liu, Yu; Fang, Wei; Shu, Laura G.; Zhao, Ming

    2013-01-01

    Introduction 99mTc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between 99mTc-Duramycin and the target tissue. Methods High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague Dawley rats. Target binding and biodistribution of 99mTc-duramycin was captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of 99mTc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of 99mTc-Duramycin in normal and ischemic myocardial tissue. Results 99mTc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to 99mTc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for 99mTc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9 fold reduction in binding affinity. Conclusion 99mTc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of 99mTc-Duramycin as a novel PE-binding agent. PMID:22534031

  5. Luminescence-Based Spectroelectrochemical Sensor for [Tc(dmpe)3]2+/+ (dmpe = 1,2-bis(dimethylphosphino)ethane) within a Charge-Selective Polymer Film

    SciTech Connect

    Chatterjee, Sayandev; Del Negro, Andrew S.; Edwards, Matthew K.; Bryan, Samuel A.; Kaval, Necati; Pantelic, Nebojsa; Morris, Laura K.; Heineman, W. R.; Seliskar, Carl J.

    2011-03-01

    A spectroelectrochemical sensor consisting of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS) was developed for [Tc(dmpe)3]+.. [Tc(dmpe)3]+ preconcentrated by ion-exchange into the SSEBS film after 20 min exposure to aqueous [Tc(dmpe)3]+ solution, resulting in a 14-fold increase in cathodic peak current compared to a bare OTE. Colorless [Tc(dmpe)3]+ was reversibly oxidized to colored [Tc(dmpe)3]2+ by cyclic voltammetry. Detection of [Tc(dmpe)3]2+ was accomplished by electrochemically cycling the complex between non-emissive [Tc(dmpe)3]+ and emissive [Tc(dmpe)3]2+ and monitoring the modulated emission (?exc = 532 nm; ?em = 660 nm). The sensor gave a linear response over the range of 0.16 to 340.0 µM.

  6. An Exploratory Study on 99mTc-RGD-BBN Peptide Scintimammography in the Assessment of Breast Malignant Lesions Compared to 99mTc-3P4-RGD2

    PubMed Central

    Chen, Qianqian; Ma, Qingjie; Chen, Minglong; Chen, Bin; Wen, Qiang; Jia, Bing; Wang, Fan; Sun, Butong; Gao, Shi

    2015-01-01

    Purpose This study aimed to explore the diagnostic performance of single photon emission computed tomography / computerized tomography (SPECT/CT) using a new radiotracer 99mTc-RGD-BBN for breast malignant tumor compared with 99mTc-3P4-RGD2. Methods 6 female patients with breast malignant tumors diagnosed by fine needle aspiration cytology biopsy (FNAB) who were scheduled to undergo surgery were included in the study. 99mTc-3P4-RGD2 and 99mTc-RGD-BBN were performed with single photon emission computed tomography (SPECT) at 1 hour after intravenous injection of 299 ± 30 MBq and 293 ± 32 MBq of radiotracers respectively at separate day. The results were evaluated by the Tumor to non-Tumor ratios (T/NT). 99mTc-RGD-BBN and 99mTc-3P4-RGD2 SPECT/CT images were interpreted independently by 3 experienced nuclear medicine physicians using a 3-point scale system. All of the samples were analyzed immunohistochemically to evaluate the integrin ?v?3 and gastrin-releasing peptide receptor (GRPR) expression. The safety, biodistribution and radiation dosimetry of 99mTc-RGD-BBN were also evaluated in the healthy volunteers. Results No serious adverse events were reported in any of the patients during the study. The effective radiation dose entirely conformed to the relevant standards. A total of 6 palpable malignant lesions were detected using 99mTc-RGD-BBN SPECT/CT with clear uptake. All malignant lesions were also detected using 99mTc-3P4-RGD2 SPECT/CT. The results showed that five malignant lesions were with clear uptake and the other one with barely an uptake. 4 malignant cases were found with both ?v?3 and GRPR expression, 1 case with only GRPR positive expression (integrin ?v?3 negative) and 1 case with only integrin ?v?3 positive expression (GRPR negative). Conclusion 99mTc-RGD-BBN is a safe agent for detecting breast cancer. 99mTc-RGD-BBN may have the potential to make up for the deficiency of 99mTc-3P4-RGD2 in the detection of breast cancer with only GRPR positive expression (integrin ?v?3 negative). The preliminary application of 99mTc-RGD-BBN has demonstrated its powerful potential in breast cancer diagnosis and therapy. PMID:25849333

  7. {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.

  8. Nano Liposomes Labeled with 99mTc-HMPAO, a Novel Agent for Blood Pool Imaging

    PubMed Central

    Sadri, Kayvan; Momenypoor, Salimeh; Dabbagh Kakhki, Vahid Reza; Sadeghi, Ramin; Aryana, Kamran; Johari Daha, Fariba; Zakavi, Seyed Rasoul; Jaafari, Mahmoud Reza

    2015-01-01

    In-vitro labeling of RBC with 99mTc is an intricate procedure and there is always a need for an alternate blood pool imaging agent. The aim of this study was to prepare an effective nano sized liposome (NLs) similar to human RBC for blood pool scintigraphy. This study formulates PEG-NLs and non-PEG-NLs using film method plus high pressure homogenization technique. Biodistribution studies were performed on BALB/C mice 1, 4 and 24 h after tail vein injection of labeled NLs with 99mTc hexamethylpropylene-amine-oxime (99mTc-HMPAO). Planar images were acquired using a 256 × 256 matrix following99m Tc-HMPAO-NLs injection into ear vein of rabbits 1, 2 and 24 h later. SPECT images were obtained 15 minutes after the injection (64 slices, 30 second/projection). The mean diameter, zeta potential and polydispersity index (PDI) of the PEG-NLs and the NLs were (80.88 ± 0.594 nm, -12.5 ± 0.56 mv, 0.158 ± 0.025) and (94.14 ± 0.114 nm, -35.5 ± 0.67 mv and 0.198 ± 0.007), respectively. 99mTc-HMPAO-PEG-NLs showed a significant circulation tracer activity (7.74 ± 1.63%ID/g at 1 h and 4.9 ± 0.77 %ID/g at 4 h), with low liver accumulation (12.07 ± 3.66 %ID/g at 1 h and 14.85 ± 1.3 %ID/g at 4 h). Heart to liver, spleen and background ROIs (region of interests) for 99m Tc-HMPAO-PEG-NLs were 1.25, 4 and 4.28 respectively at 2 h which changed to 1.06, 1.75 and 2.51 respectively at 24 h. The 99mTc-HMPAO-PEG-NLs with a prolonged blood circulation time could be an excellent RBC alternative for scintigraphy and gastrointestinal bleeding.

  9. Window generator

    NASA Astrophysics Data System (ADS)

    Johnson, William K.; May, Roger A.

    1989-03-01

    The present invention relates generally to video target recognition systems and more specifically to a window generator which receives a field of video data and applies an identification code to rectangular subregions to identify distinct target areas within a given background area. The present invention comprises a window generator which provides a 6 bit target identification number for up to 63 target areas and one background area in a frame of serially scanned data. The window generator receives a field of video data from an image data source. This video data consists of digitized frames of serially scanned data similar to a conventional television screen image, which is divided horizontally in pixels, and vertically in lines. The window generator permits any given frame to be subdivided into specific rectangular subregions, which may be located anywhere on the video picture. By allowing statistics to be collected on the individual subregions (or target areas) the window generator permits local processing of video data within the specified target areas as opposed to processing of video data over the entire video field. One embodiment of the window generator is composed of: a microprocessor, a random access memory (RAM), a comparator, a line memory, two counters, an OR gate, a frame initialization circuit, and a buffer. These elements function as described below.

  10. Physical phantom evaluation of simultaneous 99mTc/ 123I SPECT imaging

    NASA Astrophysics Data System (ADS)

    Yang, Bang-Hung; Wang, Shyh-Jen; Lee, Jhih-Shian; Jan, Meei-Ling; Chang, Chia-Jung; Chen, Jyh-Cheng

    2011-10-01

    Simultaneous dual-isotope imaging from two different energy gamma rays such as 99mTc and 123I is a promising technology in nuclear medicine. Its advantages are to abbreviate the acquisition procedure with an identical geometrical registration of the different isotope images, the same physiological condition without motion artifacts, and help patient throughput and comfort. However, the energy photopeaks of 99mTc and 123I radionuclides are very close. We had developed a new approach for accurate cross-talk and scatter corrections in simultaneous 99mTc/ 123I based on independent components analysis (ICA). Nevertheless, a large number of input energy windows are required as ICA input components, which is not useful in clinical application because commercial cameras have only 3-8 energy windows. The aim of this work was to design a new method through wavelet transformation followed by ICA with multiple energy windows (W_eICA) for cross-talk and scatter correction using a smaller number of energy windows in clinical use. There were three cylinders (A-C) with identical volume of 20 ml. Cylinder A was filled with 99mTc solution of 18.5 MBq, cylinder B with 123I solution of 18.5 MBq, and cylinder C with 99mTc solution of 55.5 MBq. The Image matrix size was 128×128 and pixel size was 3.9 mm. Three kinds of images were acquired by energy window setting. (1) For single-isotope imaging only, energy windows of 20% centered at 140 keV for 99mTc and at 159 keV for 123I were used. (2) In the asymmetric energy window method (AEW), energy window of 15% centered at 140 keV for 99mTc in conjunction with 10% asymmetric energy window in an upper bound at 159 keV for 123I was acquired. (3) Then we set six energy windows with 15 keV width ranging from 83 to 173 keV to form six images as input components of ICA. After the W_eICA method derived 99mTc/ 123I images alone, we compared the images from the W_eICA approach and the AEW method. In the results, the recovery rate of 99mTc was 1.03 and that of 123I was 1.07 from the W_eICA method. Besides, the recovery rate of 99mTc was 0.84 and that of 123I was 1.05 from the AEW approach. According to our results, the W_eICA method not only decreased the number of energy windows but also separated dual-isotope photopeaks successfully. The results have demonstrated that the W_eICA method improved the quantitative accuracy and might be an effective tool for simultaneous dual-isotope SPECT imaging.

  11. Tumour angiogenesis is reduced in the Tc1 mouse model of Down's syndrome.

    PubMed

    Reynolds, Louise E; Watson, Alan R; Baker, Marianne; Jones, Tania A; D'Amico, Gabriela; Robinson, Stephen D; Joffre, Carine; Garrido-Urbani, Sarah; Rodriguez-Manzaneque, Juan Carlos; Martino-Echarri, Estefanía; Aurrand-Lions, Michel; Sheer, Denise; Dagna-Bricarelli, Franca; Nizetic, Dean; McCabe, Christopher J; Turnell, Andrew S; Kermorgant, Stephanie; Imhof, Beat A; Adams, Ralf; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Hart, Ian R; Hodivala-Dilke, Kairbaan M

    2010-06-10

    Down's syndrome (DS) is a genetic disorder caused by full or partial trisomy of human chromosome 21 and presents with many clinical phenotypes including a reduced incidence of solid tumours. Recent work with the Ts65Dn model of DS, which has orthologues of about 50% of the genes on chromosome 21 (Hsa21), has indicated that three copies of the ETS2 (ref. 3) or DS candidate region 1 (DSCR1) genes (a previously known suppressor of angiogenesis) is sufficient to inhibit tumour growth. Here we use the Tc1 transchromosomic mouse model of DS to dissect the contribution of extra copies of genes on Hsa21 to tumour angiogenesis. This mouse expresses roughly 81% of Hsa21 genes but not the human DSCR1 region. We transplanted B16F0 and Lewis lung carcinoma tumour cells into Tc1 mice and showed that growth of these tumours was substantially reduced compared with wild-type littermate controls. Furthermore, tumour angiogenesis was significantly repressed in Tc1 mice. In particular, in vitro and in vivo angiogenic responses to vascular endothelial growth factor (VEGF) were inhibited. Examination of the genes on the segment of Hsa21 in Tc1 mice identified putative anti-angiogenic genes (ADAMTS1and ERG) and novel endothelial cell-specific genes, never previously shown to be involved in angiogenesis (JAM-B and PTTG1IP), that, when overexpressed, are responsible for inhibiting angiogenic responses to VEGF. Three copies of these genes within the stromal compartment reduced tumour angiogenesis, explaining the reduced tumour growth in DS. Furthermore, we expect that, in addition to the candidate genes that we show to be involved in the repression of angiogenesis, the Tc1 mouse model of DS will permit the identification of other endothelium-specific anti-angiogenic targets relevant to a broad spectrum of cancer patients. PMID:20535211

  12. Rapid diagnosis of occult abscesses using sup 99m Tc-labeled monoclonal antibodies

    SciTech Connect

    Coons, T.A.; Rhodes, B.A. ); Thakur, M.L. ); Marcus, C.S. ); Ballou, B. )

    1991-01-01

    Acute infections, such as appendicitis and occult infections in AIDS patients, can be diagnosed within two hours by gamma scintigraphy after i.v. administration of {sup 99m}Tc labeled antibodies reactive with human granulocytes. The antibody, murine IgM anti-SSEA-1, is partially reduced using Sn(II) to expose and protect reactive sulfide groups. The antibody is then purified, stannous tartrate and stabilizers are added, and the mixture is lyophilized. To label, sodium pertechnetate is added. After a 15 minute incubation the tracer drug is injected. The rate of accumulation and degree of concentration at the site of infection is presumptively determinative of the severity of the infection. Acceptance criteria and tests for the {sup 99m}Tc labeled antibody product have been established and validated. Greater than 93% of the {sup 99m}Tc is firmly bound to the protein as determined by quantitative HPLC. Radiochemical impurities, colloidal {sup 99m}Tc and free pertechnetate are together less than 4% as determined by thin layer chromatography. The immunoreactive fraction, measured by binding to solid phase antigen, and affinity measured be ELISA, are unchanged by the {sup 99m}Tc-direct labeling process. Two hour blood clearance in rats is within 90% of the value of the {sup 125}I labeled analog. The immunoreactive fraction decreases less than 10% when incubated in human plasma for 24 hours. This method has been compared to other direct labeling methods, and found to give higher radiochemical yields. 5 figs.

  13. Successful Labeling of \\text{99mTc-MDP Using \\text{99mTc Separated from 99Mo Produced by 100Mo(n,2n)99Mo

    NASA Astrophysics Data System (ADS)

    Nagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi; Kawauchi, Yukimasa; Sato, Norihito; Ohta, Akio; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Teranaka, Tomoyuki; Takeuchi, Nobuhiro; Igarashi, Takashi

    2011-08-01

    We have for the first time succeeded in separating \\text{99mTc from a MoO3 sample irradiated with accelerator neutrons free from any radioactive impurities and in formulating \\text{99mTc-methylene diphosphonate (\\text{99mTc-MDP). 99Mo, the mother nuclide of \\text{99mTc, was produced by the 100Mo(n,2n)99Mo reaction using about 14 MeV neutrons provided by the 3H(d,n)4He reaction at the Fusion Neutronics Source of Japan Atomic Energy Agency. The \\text{99mTc was separated from 99Mo by sublimation and its radionuclide purity was confirmed to be higher than 99.99% by ?-spectroscopy. The labeling efficiency of \\text{99mTc-MDP was shown to be higher than 99% by thin-layer chromatography. These values exceed the United States Pharmacopeia requirements for a fission product, 99Mo. Consequently, a \\text{99mTc radiopharmaceutical preparation formed by using the mentioned 99Mo can be a promising substitute for the fission product 99Mo, which is currently produced using a highly enriched uranium target in aging research reactors. A longstanding problem to ensure a reliable and constant supply of 99Mo in Japan can be partially mitigated.

  14. Two jasmonate-responsive factors, TcERF12 and TcERF15, respectively act as repressor and activator of tasy gene of taxol biosynthesis in Taxus chinensis.

    PubMed

    Zhang, Meng; Li, Shutao; Nie, Lin; Chen, Qingpu; Xu, Xiangping; Yu, Longjiang; Fu, Chunhua

    2015-11-01

    Methyl jasmonate (MeJA) is one of the most effective inducers of taxol biosynthetic genes, particularly the tasy gene. However, the mechanism underlying the regulation of tasy by MeJA is still unknown. In this study, a 550-bp 5'-flanking sequence was obtained and confirmed as the promoter of the tasy gene. Deletion analysis revealed that the fragment containing a GCC-box from -150 to -131 was the crucial jasmonate (JA)-responsive element, designated as JRE. Using JRE as bait, two binding proteins, namely TcERF12 and TcERF15, were discovered. Sequence alignment and phylogenetic analysis showed that TcERF12 was related to the repressor AtERF3, while TcERF15 was more related to the activator ORA59; these are typical GCC-box-binding ethylene-responsive factors. Both could significantly respond to MeJA for 10 and 4.5 times, respectively, in 0.5 h. When the two TcERFs were overexpressed in Taxus cells, tasy gene expression decreased by 2.1 times in TcERF12-overexpressing cells, but increased by 2.5 times in TcERF15-overexpressing cells. Results indicated that TcERF12 and TcERF15 were negative and positive regulators, respectively, in the JA signal transduction to the tasy gene by binding the GCC-box in the JRE of the tasy promoter. Our results promote further research on regulatory mechanisms of taxol biosynthesis. PMID:26445975

  15. 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

  16. New high T(c) multiferroics KBiFe?O? with narrow band gap and promising photovoltaic effect.

    PubMed

    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 d? electron in MO? network typically has a band gap (E(g)) exceeding 3.0?eV. Although a smaller E(g) (2.6?eV) can be obtained in multiferroic BiFeO?, the value is still too high for optimal solar energy applications. Computational "materials genome" searches have predicted several exotic MO? FE with E(g) < 2.0?eV, all thus far unconfirmed because of synthesis difficulties. Here we report a new FE compound with MO? tetrahedral network, KBiFe?O?, which features narrow E(g) (1.6?eV), high Curie temperature (T(c) ~ 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 BiFeO?. This finding may open a new avenue to discovering and designing optimal FE compounds for solar energy applications. PMID:23405279

  17. Kinetics of reactions of technetium. VIII. Reduction of Tc(VII) by ascorbic acid in HC1 solution

    SciTech Connect

    Koltunov, V.S.; Gomonova, T.V.; Shapovalov, M.P.; Abramova, I.G.

    1988-03-01

    The reduction of Tc(VII) by ascorbic acid in HCl solution proceeds according to the equation 2TcO/sub 4//sup -/ + 3C/sub 6/H/sub 8/O/sub 6/ + 10HCl = 2TcCl/sub 5//sup -/ + 3C/sub 6/H/sub 6/O/sub 6/ + 8H/sub 2/O. The reaction is characterized by an induction period, after the conclusion of which its rate is equal to -d(Tc(VII))/dt = k(Tc(VII)) x (C/sub 6/H/sub 8/O/sub 6/) (H/sup +/)/sup 1.6/, where k = 0.898 + 0.064 liter/sup 2.6//mole/sup 2.6./min at 25/sup 0/C and ..mu.. = 2. The reaction mechanism includes a slow step of interaction of TcO/sub 3//sup +/ ions with C/sub 6/H/sub 8/O/sub 6/ molecules and ascorbate complexes of Tc(IV). The full kinetic equation describing the course of the reaction, including the induction period, is obtained.

  18. 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

  19. Adsorption between TC-stabilized AuNPs and the phosphate group: application of the PTP1B activity assay.

    PubMed

    Lv, Jun; Wang, Xiaonan; Zhang, Yuanyuan; Li, Defeng; Zhang, Juan; Sun, Lizhou

    2015-12-01

    Based on the adsorption between tetracycline (TC) and phosphate groups, a general colorimetric method is explored in this work by using TC-stabilized gold nanoparticles (TC/AuNPs) and 4-aminophenyl phosphate-functionalized Fe3O4 magnetic nanoparticles (APP/MNPs). Taking protein tyrosine phosphatase 1B (PTP1B) as an example, 4-aminophenyl phosphate (APP) can be hydrolyzed into 4-aminophenol (AP) by PTP1B, resulting in the disappearance of the phosphate group on the outer layer of MNPs and the loss of corresponding adsorptive ability. Upon addition of TC/AuNP solution, TC/AuNPs will remain in the supernatant solution after magnetic separation and a high absorbance value can be observed. So PTP1B activity is related to the concentrations of TC/AuNPs in the supernatant solution. In this work, the enzyme activity can be determined at levels as low as 0.0885 U mL(-1) and over a linear detection range as wide as 0.1 U mL(-1) to 0.9 U mL(-1). Moreover, using the proposed method, the inhibition effect of betulinic acid (BA) and sodium orthovanadate (Na3VO4) on PTP1B activity can be tested with IC50 values of 30 ?M and 4 ?M, respectively. Therefore, a universal platform for the accurate colorimetric analysis of kinase and phosphatase activities can be established through the adsorption between TC and phosphate groups. PMID:26523458

  20. Trypanosoma cruzi TcSMUG L-surface Mucins Promote Development and Infectivity in the Triatomine Vector Rhodnius prolixus

    PubMed Central

    Gonzalez, Marcelo S.; Souza, Marcela S.; Garcia, Eloi S.; Nogueira, Nadir F. S.; Mello, Cícero B.; Cánepa, Gaspar E.; Bertotti, Santiago; Durante, Ignacio M.; Azambuja, Patrícia; Buscaglia, Carlos A.

    2013-01-01

    Background TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector. Methodology and Principal Findings Here, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy. Conclusion and Significance Together, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus. PMID:24244781

  1. Improved synthesis and biological evaluation of Tc-99m radiolabeled AMO for miRNA imaging in tumor xenografts.

    PubMed

    Kang, Lei; Fan, Zhongyi; Sun, Hongwei; Feng, Yingying; Ma, Chao; Yan, Ping; Zhang, Chunli; Ma, Huan; Hao, Pan; Chen, Xueqi; Zheng, Zhibing; Xu, Xiaojie; Wang, Rongfu

    2015-11-01

    MicroRNAs (miRNAs) have been considered as important biomarkers for malignant tumors. In this study, we introduced an improved (99m) Tc labeling method for noninvasive visualization of overexpressed miRNAs in tumor-bearing mice. Anti-miRNA-21 oligonucleotide (AMO) with partial 2'-O-methyl and phosphorothioate modification was designed and chemically synthesized. After conjugated with NHS-MAG3, AMO was labeled with (99m) Tc. Optimization was made to shorten reaction time and to improve labeling efficiency. Labeling efficiency was 97%, and specific activity was 2.78?MBq/ng. During 12?h, (99m) Tc-AMO showed no significant degradation by gel electrophoresis. Its radiochemical purity was stable, between 95.8% and 99.1%. Further, (99m) Tc-AMO decreased the level of miR-21 and increased the expression of PTEN protein at cellular level, shown by qRT-PCR and Western blot. Fluorescent protein labeled AMO displayed specific distribution and good stability in tumor cells. After the administration in tumor-bearing mice, (99m) Tc-AMO showed more radioactive uptake in the miR-21 over-expressed tumors than scramble control. Biodistribution results further proved the significant difference of tumor uptake between (99m) Tc-AMO and (99m) Tc-control. Therefore, this study presents an improved method with shorten time to prepare a (99m) Tc radiolabeled AMO. In addition, it supports the role of (99m) Tc-AMO for noninvasive visualization of miR-21 in malignant tumors. PMID:26503645

  2. Tribolium castaneum RR-1 Cuticular Protein TcCPR4 Is Required for Formation of Pore Canals in Rigid Cuticle

    PubMed Central

    Noh, Mi Young; Muthukrishnan, Subbaratnam; Kramer, Karl J.; Arakane, Yasuyuki

    2015-01-01

    Insect cuticle is composed mainly of structural proteins and the polysaccharide chitin. The CPR family is the largest family of cuticle proteins (CPs), which can be further divided into three subgroups based on the presence of one of the three presumptive chitin-binding sequence motifs denoted as Rebers-Riddiford (R&R) consensus sequence motifs RR-1, RR-2 and RR-3. The TcCPR27 protein containing the RR-2 motif is one of the most abundant CPs present both in the horizontal laminae and in vertical pore canals in the procuticle of rigid cuticle found in the elytron of the red flour beetle, Tribolium castaneum. Depletion of TcCPR27 by RNA interference (RNAi) causes both unorganized laminae and pore canals, resulting in malformation and weakening of the elytron. In this study, we investigated the function(s) of another CP, TcCPR4, which contains the RR-1 motif and is easily extractable from elytra after RNAi to deplete the level of TcCPR27. Transcript levels of the TcCPR4 gene are dramatically increased in 3 d-old pupae when adult cuticle synthesis begins. Immunohistochemical studies revealed that TcCPR4 protein is present in the rigid cuticles of the dorsal elytron, ventral abdomen and leg but not in the flexible cuticles of the hindwing and dorsal abdomen of adult T. castaneum. Immunogold labeling and transmission electron microscopic analyses revealed that TcCPR4 is predominantly localized in pore canals and regions around the apical plasma membrane protrusions into the procuticle of rigid adult cuticles. RNAi for TcCPR4 resulted in an abnormal shape of the pore canals with amorphous pore canal fibers (PCFs) in their lumen. These results support the hypothesis that TcCPR4 is required for achieving proper morphology of the vertical pore canals and PCFs that contribute to the assembly of a cuticle that is both lightweight and rigid. PMID:25664770

  3. Loss of Tc-arrow and canonical Wnt signaling alters posterior morphology and pair-rule gene expression in the short-germ insect, Tribolium castaneum.

    PubMed

    Bolognesi, Renata; Fischer, Tamara D; Brown, Susan J

    2009-07-01

    Wnt signaling has been implicated in posterior patterning in short-germ insects, including the red flour beetle Tribolium castaneum (Bolognesi et al. Curr Biol 18:1624-1629, 2008b; Angelini and Kaufman Dev Biol 283:409-423, 2005; Miyawaki et al. Mech Dev 121:119-130, 2004). Specifically, depletion of Wnt ligands Tc-Wnt1 and Tc-WntD/8 produces Tribolium embryos lacking abdominal segments. Similar phenotypes are produced by depletion of Tc-porcupine (Tc-porc) or Tc-pangolin (Tc-pan), indicating that the signal is transmitted through the canonical Wnt pathway (Bolognesi et al. Curr Biol 18:1624-1629, 2008b). Here we show that RNAi for the receptor Tc-arrow produced similar truncated phenotypes, providing additional evidence supporting canonical signal transduction. Furthermore, since in Tribolium segments are defined sequentially by a pair-rule gene circuit that, when interrupted, produces truncated phenotypes (Choe et al. Proc Natl Acad Sci U S A 103:6560-6564, 2006), we investigated the relationship between loss of Wnt signaling and this pair-rule gene circuit. After depletion of the receptor Tc-arrow, expression of Tc-Wnt1 was noticeably absent from the growth zone, while Tc-WntD/8 was restricted to a single spot of expression in what remained of the posterior growth zone. The primary pair-rule genes Tc-runt (Tc-run) and Tc-even-skipped (Tc-eve) were expressed normally in the anterior segments, but were reduced to a single spot in the remnants of the posterior growth zone. Thus, expression of pair-rule genes and Tc-WntD/8 are similarly affected by depletion of Wnt signal and disruption of the posterior growth zone. PMID:19705150

  4. Generation Next

    ERIC Educational Resources Information Center

    Hawkins, B. Denise

    2010-01-01

    There is a shortage of accounting professors with Ph.D.s who can prepare the next generation. To help reverse the faculty deficit, the American Institute of Certified Public Accountants (CPAs) has created the new Accounting Doctoral Scholars program by pooling more than $17 million and soliciting commitments from more than 70 of the nation's…

  5. A clinical study of /sup 99m/Tc dimercaptosuccinic acid uptake in obstructed kidneys: comparison with the creatinine clearance

    SciTech Connect

    De Maeyer, P.; Simons, M.; Oosterlinck, W.; De Sy, W.A.

    1982-07-01

    We studied 17 hydronephrotic kidneys owing to stenosis of the pyeloureteral junction. Preoperative uptake of /sup 99m/Tc dimercaptosuccinic acid was compared to early postoperative unilateral creatinine clearance, measured by urine collection from the nephrostomy tube. An excellent correlation was found. Therefore, uptake of /sup 99m/Tc dimercaptosuccinic acid represents a reliable parameter of renal function even in the presence of severe urinary tract obstruction. However, /sup 99m/Tc dimercaptosuccinic acid uptake should be measured more than 24 hours after injection of the tracer.

  6. The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs

    PubMed Central

    Duz, Ana Luiza Cassin; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Aguiar-Soares, Rodrigo Dian Oliveira; Cardoso, Jamille Mirelle de Oliveira; de Oliveira, Flávia Carvalho Bitencourt; Reis, Levi Eduardo Soares; Tafuri, Washington Luiz; Veloso, Vanja Maria; Reis, Alexandre Barbosa; Carneiro, Cláudia Martins

    2014-01-01

    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

  7. Labelling, biodistribution and compartmental analysis of N-acetylcysteine labelled with Tc-99m. Comparative investigation with with sup 9 sup 9 sup m Tc-MIBI in an in vivo tumoral model

    E-print Network

    Faintuch, B L

    1997-01-01

    Labelling and biodistribution studies were done with two different ligands, respectively Methoxy isobutyl isonitrile (MIBI) and N-acetylcysteine (NAC), employing Tc-99m as a tracer. The main objective was to assess the pharmacokinetic properties of the second substance, aiming at its possible application in cancer diagnosis. To this purpose an in vivo investigation was done using healthy and tumor-bearing rats with experimental cancer. Images of tumor-bearing rats registered in a scintillation camera indicated that with sup 9 sup 9 sup m Tc-MIBI none of the two selected times was adequate for visualization of the cancer mass. In contrast, sup 9 sup 9 sup m Tc-NAC permitted clear identification of the humor, four hours after injection. The results have demonstrated that sup 9 sup 9 sup m Tc-NAC is a radiopharmaceutical with affinity for cancer tissue and promising for further investigation concerning imaging diagnosis of tumors.

  8. 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

  9. Solid targets for 99mTc production on medical cyclotrons

    NASA Astrophysics Data System (ADS)

    Hanemaayer, V.; Zeisler, S. K.; Buckley, K. R.; Klug, J.; Kovacs, M.; Bérnard, F.; Ruth, T. J.; Schaffer, P.

    2012-12-01

    A method to produce solid 100Mo metal targets capable of withstanding proton irradiation with a power density of up to 1.1 kW/cm2 has been developed. The method of choice involves the electrodeposition of enriched 100Mo powder onto a tantalum backing, followed by high-temperature sintering in order to afford a coating that is sufficient to withstand bombardment for extended periods of time, yet reactive enough to allow for oxidative dissolution in seconds. This method is amenable to high-throughput techniques to allow for the production of 99mTc via the 100Mo(p,2n)99mTc reaction on small medical cyclotrons.

  10. 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.

  11. 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.

  12. Multi-Channel High-Tc SQUID Detection System for Metallic Contaminants

    NASA Astrophysics Data System (ADS)

    Kitamura, Yoshihiro; Hatsukade, Yoshimi; Tanaka, Saburo; Ohtani, Takeyoshi; Suzuki, Shuichi

    Finding ultra-small metallic contaminants is a big issue for manufacturers of lithium-ion batteries nowadays. Therefore, we have developed high-Tc SQUID systems for detection of such fine magnetic metallic contaminants. In this paper, we constructed an eight channel high-Tc SQUID gradiometer system for inspection of a sheet electrode of a lithium ion battery with width of about 70 mm. By this system, a small iron ball of about 30 ?m in diameter was successfully detected. It is shown that this system has a detectable range of 70 mm in width. These results suggest that the system is a promising tool for the detection of the contaminants in lithium ion batteries.

  13. Enhancement of Tc in the atomic phase of iodine-doped hydrogen at high pressures.

    PubMed

    Duan, Defang; Tian, Fubo; Liu, Yunxian; Huang, Xiaoli; Li, Da; Yu, Hongyu; Ma, Yanbin; Liu, Bingbing; Cui, Tian

    2015-12-01

    The high-pressure structures and superconductivity of iodine-doped hydrogen have been studied by ab initio calculations. Above 100 GPa, we discover a stable phase with Pnma symmetry in the H2I stoichiometry that consists of a monatomic iodine tube trapping hydrogen molecular units. Interestingly, H2 molecular units dissociate and form a novel atomic phase with R3[combining macron]m symmetry at 246 GPa. Further electron-phonon coupling calculations predict the critical temperature of superconductivity Tc to be 3.8 K for the Pnma phase and 33 K for the R3[combining macron]m phase at 240 GPa. Significantly, the Tc of the R3[combining macron]m phase is enhanced approximately 8 times that of the Pnma phase, which is mainly attributed to the reason that H2 molecules are broken exhibiting an atomic character in the R3[combining macron]m phase. PMID:26583809

  14. A computerized compact module for separation of (99m)Tc-radionuclide from molybdenum.

    PubMed

    Chattopadhyay, Sankha; Barua, Luna; De, Anirban; Saha Das, Sujata; Kuniyil, Remashan; Bhaskar, Partha; Pal, Sasanka Shekhar; Sarkar, Sishir Kumar; Das, Malay Kanti

    2012-11-01

    An automated closed cycle module for the separation and recovery of various isotopes, radioactive or non-radioactive, using solvent extraction and column chromatography techniques, and in particular, for separation and recovery of (99m)Tc from low-medium specific activity (99)Mo, is described. The module may also be applicable for separation of (99m)Tc produced in a cyclotron. The module is safe and reliable to avoid human interference and hazards posed by handling of radioactive and hazardous chemicals. The entire system of automation includes a user-friendly PC based graphical user interface (GUI) that actually supervises the process via an embedded system based electronic controller. PMID:22954519

  15. Preliminary investigation of PAGAT polymer gel radionuclide dosimetry of Tc-99m

    NASA Astrophysics Data System (ADS)

    Braun, Kelly; Bailey, Dale; Hill, Brendan; Baldock, Clive

    2009-05-01

    PAGAT polymer gel was investigated as a suitable dosimeter materials for measuring absorbed dose from the unsealed source radionuclide Tc-99m. Differing amounts of Tc-99m over the range of 25-5000 MBq were introduced into a normoxic polymer gel mixture (PAGAT) in sealed nitrogen-filled P6 glass vials. After irradiation the gels were evaluated using MRI more than 48 hours after preparation to allow for radioactive decay. The dose delivered to the vial was also calculated empirically. R2 versus total activity curves were obtained over a number of experiments and these were used to evaluate the relationship between the amount of gel polymerization and the dose deposited by the radionuclide. A linear response up to 1000 MBq (corresponding to 20Gy) was displayed and was still behaving monotonically at 5000 MBq. Polymer gels offer the potential to measure radiation dose three-dimensionally using MRI.

  16. Preparation, biodistribution and scintigraphic evaluation of (99m)Tc-lincomycin.

    PubMed

    Bokhari, Tanveer Hussain; Rizvi, Faheem Askari; Roohi, Samina; Hina, Saira; Ahmad, Mushtaq; Khalid, Muhammad; Iqbal, Munawar

    2015-11-01

    A complex of lincomycin was synthesized with technetium-99m. The synthesis was carried out by using SnCl2.2H2O as reducing agent and ascorbic acid as stabilizer. The effect of various parameters such as amount of ligand/reducing agent, pH value and reaction time on radio labeling process was studied. The characterization of the (99m)Tc-Lincomycin was performed by HPLC and electrophoresis Biodistribution studies were carried out by analyzing the model of bacterial infectious rats (Sprague-Dawley). The uptake of infectious lesions at different time interval was also studied by using scintigraphic technique. The complex showed effective target to non-target ratio for various inflammatory or infectious lesions. The (99m)Tc-Lincomycin effective binding to living bacteria and could be used successfully as an infection imaging agent. PMID:26639473

  17. TC and H NMR studies of PQQ and selected derivatives. [Pyrroloquinoline quinone

    SciTech Connect

    Houck, D.R.; Unkefer, C.J.

    1988-01-01

    The ortho-quinone structure of pyrroloquinoline quinone (PQQ) is famous for its reactivity with nucleophilic species of carbon, nitrogen, and oxygen(Duine et. al. 1987). In fact, the crystal structure of PQQ was solved in the form of the C-5 acetone adduct(Salisbury et. al 1979). The propensity of the ortho-quinone to accept nucleophiles is the chemical basis of the function of PQQ at enzyme active sites. The present study focuses on the NMR of PQQ and various derivatives formed with oxygen and nitrogen nucleophiles. Our goals are to assign the H, TC, and VN NMR spectra and to rigorously confirm the structures of the adducts. Once the NMR data of the relevant adducts are well defined, we will use TC and VN labeled substrates to probe the active sites of PQQ containing enzymes. 7 refs., 2 figs., 1 tab.

  18. Feasibility of far-infrared radiation modulators using high-{Tc} superconductors

    SciTech Connect

    Zhang, Z.M.

    1996-12-31

    The potential of using high-{Tc} superconductors as intensity modulators for far-infrared radiation is investigated in this work. Reflectance and transmittance for several design structures are computed using the published optical constants of the superconductor YBa{sub 2}Cu{sub 3}O{sub 7} and substrate materials. Notable differences in the reflectance and transmittance between the superconducting state and the normal state are illustrated. The best results are obtained based on the reflectance of thin films (10 nm--50 nm thick) on thin substrates (less than 100 {micro}m thick) and for radiation incident on the substrate. This study demonstrates that high-{Tc} superconductive thin films can be used to build far-infrared radiation modulators. Future experimental study is recommended in order to materialize this promising thermooptical device.

  19. Incidentally detected diaphragmatic hernia mimicking angina pectoris with Tc-99m MIBI myocardial perfusion imaging

    PubMed Central

    C?nar, Alev; Sad?c, Murat; Dem?rel, Koray; Korkmaz, Meliha

    2013-01-01

    In recent years 99mTechnetium methoxy-isobutyl-isonitrile (99mTc MIBI) is widely used in the evaluation of myocardial perfusion imaging (MPI). In this imaging protocol besides the cardiac evaluation, numerous other organs are included in the field of view. 99mTechnetium MIBI is taken up in all metabolically active tissue in the body except for the brain. Extracardiac uptake patterns as benign or serious conditions can be revealed during the MPI. In the imaging protocol, we should be aware of distribution of this radiotracer in order to recognize the abnormal uptake. Here in, we present a large diaphragmatic hernia, seemed as a mirror vision of myocardium that was determined incidentally during the MPI with 99mTc MIBI. PMID:24379540

  20. Magnetocumulative generator

    DOEpatents

    Pettibone, J.S.; Wheeler, P.C.

    1981-06-08

    An improved magnetocumulative generator is described that is useful for producing magnetic fields of very high energy content over large spatial volumes. The polar directed pleated magnetocumulative generator has a housing providing a housing chamber with an electrically conducting surface. The chamber forms a coaxial system having a small radius portion and a large radius portion. When a magnetic field is injected into the chamber, from an external source, most of the magnetic flux associated therewith positions itself in the small radius portion. The propagation of an explosive detonation through high-explosive layers disposed adjacent to the housing causes a phased closure of the chamber which sweeps most of the magnetic flux into the large radius portion of the coaxial system. The energy content of the magnetic field is greatly increased by flux stretching as well as by flux compression. The energy enhanced magnetic field is utilized within the housing chamber itself.

  1. Photon generator

    DOEpatents

    Srinivasan-Rao, Triveni (Shoreham, NY)

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  2. 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.

  3. What makes the Tc of FeSe/SrTiO3 so high?

    NASA Astrophysics Data System (ADS)

    Dung-Hai, Lee

    2015-11-01

    This paper reviews some of the recent progresses in the study of high temperature superconductivity in the interface between a single unit cell FeSe and SrTiO3. It offers the author’s personal view of why Tc is high and how to further increase it. Project supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (Grant No. DE-AC02-05CH11231).

  4. Efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal myocardial infarction

    SciTech Connect

    Powers, T.A.; Tyler, J.L.; Kulkarni, M.V.

    1983-03-01

    We studied the efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal evidence of acute myocardial infarction. Only patients with positive enzyme findings (regardless of ECG findings) had scans with greater than or equal to 2+ focal uptake. None of 26 patients with negative or equivocal enzyme findings (regardless of ECG findings) had greater than 2+ diffuse uptake. These results support the contention that infarct-avid imaging has little clinical utility in patients with equivocal evidence of myocardial infarction.

  5. Gamma scintigraphy using Tc-99m labeled antibody to human chorionic gonadotropin

    SciTech Connect

    Morrison, R.T.; Lyster, D.M.; Alcorn, L.N.; Rhodes, B.A.; Breslow, K.; Burchiel, S.W.

    1984-01-01

    A case report is presented describing a 27-year-old woman with invasive trophoblastic hydatidiform mole metastatic to the lung. Gamma scintiscanning, using a polyclonal and monoclonal antibody specific to human chorionic gonadotropin, hCG, and labeled with Tc-99m, is described. The area of the primary lesion in the uterus was demonstrated with both antibodies tested without computer subtraction techniques; metastatic deposits in the lung were detected only with the aid of blood pool subtraction techniques.

  6. Transsplenic portal scintigraphy using 99mTc-mebrofenin in normal dogs.

    PubMed

    Morandi, Federica; Cole, Robert C; Echandi, Rita L; Daniel, Gregory B

    2007-01-01

    Transsplenic portal scintigraphy using sodium pertechnetate is superior to per-rectal portal scintigraphy due to improved visualization of the portal vasculature with decreased patient and personnel exposure. The purpose of this study was to describe the use of 99mTc-mebrofenin, the radiopharmaceutical of choice for the evaluation of hepatic function, in place of pertechnetate for transsplenic portal scintigraphy in normal dogs. Sixteen juvenile dogs underwent transsplenic portal scintigraphy using 37-130 MBq 99mTc-mebrofenin in a 0.2-0.5 ml volume. After the initial dynamic acquisition obtained at 4 frames/s in right lateral recumbency, static right lateral, and ventral views were obtained at 5, 10, 15, 20, 25, 30, 40, 50, and 60 min. A nuclear angiogram of the splenic and portal veins was visible in all dogs, followed by rapid distribution of the radiopharmaceutical in the liver. Hepatic morphology was more easily defined than with pertechnetate. Transit time could not be calculated due to the high hepatic extraction of 99mTc-mebrofenin. Mean +/- SD shunt fraction was 0.8 +/- 0.8%. Time to peak liver activity was 3.1 +/- 1.1 min, and hepatic excretion T1/2 was 19.4 +/- 6.3 min. No visible blood pool and cardiac activity was seen after 5 min. The mean +/- SD time to visualization of defined biliary activity was 8.8 +/- 2.9 min. Absorption from the spleen was significantly higher than that reported for pertechnetate (87.9 +/- 8.2%, vs. 52.5 +/- 19.1%). 99mTc-mebrofenin can be used in place of pertechnetate for transsplenic portal scintigraphy, with the advantage of combining quantitative parameters of liver function with the already known advantage of transsplenic portal scintigraphy. PMID:17508519

  7. Long-Duration Space Flight Provokes Pathologic Q-Tc Interval Prolongation

    NASA Technical Reports Server (NTRS)

    D'Aunno, DOminick S.; Dougherty, Anne H.; DeBlock, Heidi F.; Meck, Janice V.

    2002-01-01

    Space flight has a profound influence on the cardiovascular and autonomic nervous systems. Alterations in baroreflex function, plasma catecholamine concentrations, and arterial pressure regulation have been observed. Changes in autonomic regulation of cardiac function may lead to serious rhythm disturbances. In fact, ventricular tachycardia has been reported during long-duration space flight. The study aim was to determine the effects of space flight on cardiac conduction. Methods and Results: Electrocardiograms (ECGs) and serum electrolytes were obtained before and after short-duration (SD) (4-16 days) and long-duration (LD) (4-6 months) missions. Holter recordings were obtained from 3 different subjects before, during and after a 4-month mission. P-R, R-R, and Q-T intervals were measured manually in a random, blinded fashion and Bazzet's formula used to correct the Q-T interval (Q-Tc). Space flight had no clinically significant effect on electrolyte concentrations. P-R and RR intervals were decreased after SD flight (p<0.05) and recovered 3 days after landing. In the same subjects, P-R and Q-Tc intervals were prolonged after LD flight (p<0.01). Clinically significant Q-Tc prolongation (>0.44 sec) occurred during the first month of flight and persisted until 3 days after landing (p<0.01). Conclusions - Space flight alters cardiac conduction with more ominous changes seen with LD missions. Alterations in autonomic tone may explain ECG changes associated with space flight. Primary cardiac changes may also contribute to the conduction changes with LD flight. Q-Tc prolongation may predispose astronauts to ventricular arrhythmias during and after long-duration space flight.

  8. Pulmonary epithelial clearance of 99mTc-DTPA after thrombin-induced pulmonary microembolism

    SciTech Connect

    Cooper, J.A.; Feustel, P.J.; Line, B.R.; Malik, A.B.

    1986-10-01

    We investigated the effect of thrombin-induced pulmonary microembolism on the pulmonary clearance rate of aerosolized 99mTc diethylenetriamine pentaacetic acid (99mTc-DTPA) in awake, chronically prepared sheep. Chest activity was recorded after administration of a 0.44 micron aerosol of 99mTc-DTPA. Decay-corrected data were fit to an exponential and expressed as percent decrease per min (%/min). Sheep were given alpha-thrombin intravenously (80 U/kg for 10 min) 60 min after the aerosol administration. The clearance rate prior to alpha-thrombin was 0.35 +/- 0.05 %/min (mean +/- SEM). During alpha-thrombin administration, the clearance rate increased to 5.84 +/- 0.70 %/min (p less than 0.001 from baseline), but returned to 0.41 +/- 0.06 %/min within 30 min after the end of the thrombin infusion. The increased clearance rate during alpha-thrombin administration was not due to increased lung volume since alpha-thrombin did not change functional residual capacity. Moreover, the clearance rate was unchanged during gamma-thrombin administration, which does not induce coagulation, or during alpha-thrombin challenge in defibrinogenated animals. alpha-thrombin administration in neutrophil-depleted sheep caused a transient increase in DTPA clearance similar to that in control sheep, suggesting that the increase occurred independently of neutrophils. The results indicate that alpha-thrombin causes a large, transient increase in 99mTc-DTPA clearance, which may be the result of increased epithelial permeability. This response is dependent on the activation of intravascular coagulation.

  9. On the origin of stars with and without planets. Tc trends and clues to Galactic evolution

    NASA Astrophysics Data System (ADS)

    Adibekyan, V. Zh.; González Hernández, J. I.; Delgado Mena, E.; Sousa, S. G.; Santos, N. C.; Israelian, G.; Figueira, P.; Bertran de Lis, S.

    2014-04-01

    We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) with stellar parameters and Galactic orbital parameters in order to understand the nature of the peculiar chemical signatures of these stars and the possible connection with planet formation. We find that the Tc slope significantly correlates (at more than 4?) with the stellar age and the stellar surface gravity. We also find tentative evidence that the Tc slope correlates with the mean galactocentric distance of the stars (Rmean), suggesting that those stars that originated in the inner Galaxy have fewer refractory elements relative to the volatiles. While the average Tc slope for planet-hosting solar analogs is steeper than that of their counterparts without planets, this difference probably reflects the difference in their age and Rmean. We conclude that the age and probably the Galactic birth place are determinant to establish the star's chemical properties. Old stars (and stars with inner disk origin) have a lower refractory-to-volatile ratio. Based on observations collected with the HARPS spectrograph at the 3.6-m telescope (072.C-0488(E)), installed at the La Silla Observatory, ESO (Chile), with the UVES spectrograph at the 8-m Very Large Telescope program IDs: 67.C-0206(A), 074.C-0134(A), 075.D-0453(A), installed at the Cerro Paranal Observatory, ESO (Chile), and with the UES spectrograph at the 4.2-m William Herschel Telescope, installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma.Appendix A is available in electronic form at http://www.aanda.org

  10. Transient nonvisualization of the gallbladder by Tc-99m HIDA cholescintigraph

    SciTech Connect

    Kempi, G.E.; Van Der Linden, W.

    1982-02-01

    In five of seven patients with acute pancreatitis, Tc-99m HIDA scintigraphy failed to visualize the gallbladder. In all five patients the gallbladder was later found to be normal and in three of them normal filling was obtained at a repeat examination performed after the attack had subsided. Transient nonvisualization of the gallbladder in acute pancreatitis is probably due to disturbed motility of the biliary tree.

  11. Transient nonvisualization of the gallbladder by Tc-99m HIDA cholescintigraphy in acute pancreatitis: concise communication

    SciTech Connect

    Edlund, G.; Kempi, V.; van der Linden, W.

    1982-02-01

    In five of seven patients with acute pancreatitis, Tc-99m HIDA scintigraphy failed to visualize the gallbladder. In all five patients the gallbladder was later found to be normal and in three of them normal filling was obtained at a repeat examination performed after the attack had subsided. Transient nonvisualization of the gallbladder in acute pancreatitis is probably due to disturbed motility of the biliary tree.

  12. Down's syndrome-like cardiac developmental defects in embryos of the transchromosomic Tc1 mouse

    PubMed Central

    Dunlevy, Louisa; Bennett, Mike; Slender, Amy; Lana-Elola, Eva; Tybulewicz, Victor L.; Fisher, Elizabeth M.C.; Mohun, Timothy

    2010-01-01

    Aims Cardiac malformations are prevalent in trisomies of human chromosome 21 [Down's syndrome (DS)], affecting normal chamber separation in the developing heart. Efforts to understand the aetiology of these defects have been severely hampered by the absence of an accurate mouse model. Such models have proved challenging to establish because synteny with human chromosome Hsa21 is distributed across three mouse chromosomes. None of those engineered so far accurately models the full range of DS cardiac phenotypes, in particular the profound disruptions resulting from atrioventricular septal defects (AVSDs). Here, we present analysis of the cardiac malformations exhibited by embryos of the transchromosomic mouse line Tc(Hsa21)1TybEmcf (Tc1) which contains more than 90% of chromosome Hsa21 in addition to the normal diploid mouse genome. Methods and results Using high-resolution episcopic microscopy and three-dimensional (3D) modelling, we show that Tc1 embryos exhibit many of the cardiac defects found in DS, including balanced AVSD with single and separate valvar orifices, membranous and muscular ventricular septal defects along with outflow tract and valve leaflet abnormalities. Frequencies of cardiac malformations (ranging from 38 to 55%) are dependent on strain background. In contrast, no comparable cardiac defects were detected in embryos of the more limited mouse trisomy model, Dp(16Cbr1-ORF9)1Rhr (Ts1Rhr), indicating that trisomy of the region syntenic to the Down's syndrome critical region, including the candidate genes DSCAM and DYRK1A, is insufficient to yield DS cardiac abnormalities. Conclusion The Tc1 mouse line provides a suitable model for studying the underlying genetic causes of the DS AVSD cardiac phenotype. PMID:20558441

  13. Stimulating Effect of a Novel Synthesized Sulfonamido-Based Gallate ZXHA-TC on Primary Osteoblasts

    PubMed Central

    Jin, Pan; Liao, Liang; Lin, Xiao; Guo, Qinggong; Lin, Cuiwu; Wu, Huayu

    2015-01-01

    Purpose This study is intended to investigate the effects of plants or plant-derived antioxidants on prevention of osteoporosis through the maintenance of reactive oxygen species (ROS) at a favorable level. Materials and Methods In this study, a novel antioxidant, namely 3,4,5-Trihydroxy-N-[4-(5-hydroxy-6-methoxy-pyrimidin-4-ylsulfamoyl)-phenyl]-benzamide (ZXHA-TC) was synthesized from gallic acid and sulfadimoxine. Its effect on osteoblast metabolism was investigated via the detection of cell proliferation, cell viability, production of ROS, and expression of osteogenic-specific genes including runt-related transcription factor 2 (RUNX2), bone sialoprotein (BSP), osteocalcin (OCN), alpha-1 type I collagen (COL1A1), and osteogenic-related proteins after treatment for 2, 4, and 6 days respectively. Results The results showed that ZXHA-TC has a stimulating effect on the proliferation and osteogenic differentiation of primary osteoblasts by promoting cell proliferation, cell viability, and the expression of genes BSP and OCN. Productions of bone matrix and mineralization were also increased by ZXHA-TC treatment as a result of up-regulation of COL1A1 and alkaline phosphatase (ALP) at the early stage and down-regulation of both genes subsequently. A range of 6.25×10-3 µg/mL to 6.25×10-1 µg/mL is the recommended dose for ZXHA-TC, within which 6.25×10-2 µg/mL showed the best performance. Conclusion This study may hold promise for the development of a novel agent for the treatment of osteoporosis. PMID:25837183

  14. Detection of pleural effusions and increased lung water by Tc-99m DTPA imaging

    SciTech Connect

    Glass, E.C.; Karelitz, J.R.; Bennett, L.R.

    1985-05-01

    The purpose of this study is to report a systematic observation of uptake or retention of Tc-99m DTPA in pleural effusions and other abnormal states of increased lung water. 24 patients who underwent renal imaging with 10 mCi Tc-99m DTPA were included. Imaging was performed with a large field of view camera for 0-03 minutes after injection and delayed images acquired 2-4 hours later. The images encompassed the mid and lower thorax as well as kidneys. 15 patients showed, at 0-5 minutes, cold areas at lung bases that later showed relatively increased activity at 2-4 hours (hot on delayed images). 14 of these 15 patients showed pleural effusions on chest x-ray. Small bilateral effusions were more clearly demonstrated by scan than by x-ray in 8 of 15 patients. One patient with pneumonia showed an immediate hot area in the infected lobe, and two with pulmonary edema and congestive failure showed diffuse lung retention of Tc-99m on delayed images. Among 9 patients who did not demonstrate abnormal cold or hot areas in their lungs on DTPA images, none had clinical or x-ray evidence of pleural effusion, pneumonia, or congestive failure (100% negative predictive value). Differences in rate constants for diffusion into vs. out of pleural fluid provide a plausible explanation for the observed retention of tracer in effusions, as seen on delayed images. This study indicates that imaging with Tc-99m DTPA provides information of diagnostic value in the detection of pleural effusions. Futhermore, the data suggests that DTPA imaging may also be useful as a simple, cost-effective method to detect other conditions in which regional lung water is abnormally increased.

  15. 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.

  16. Is the 1254T>C polymorphism in the DMT1 gene associated with Parkinson's disease?

    PubMed

    Saadat, Selva Moheb; De?irmenci, ?rfan; Özkan, Serhat; Saydam, Faruk; Özdemir Köro?lu, Zeynep; Çolak, Ertu?rul; Güne?, Hasan Veysi

    2015-05-01

    Parkinson's disease (PD) is a late-onset neurodegenerative disorder with both familial and sporadic presentation. The main pathological characteristic of PD is the death of dopaminergic neurons in the substantia nigra (SN) pars compacta. PD is the second most common neurodegenerative disease worldwide, after Alzheimer's disease. Recent studies have suggested increased levels of iron and iron-binding proteins in the brains of patients with PD. Divalent metal transporter 1 (DMT1) is one protein responsible for iron transport. Postmortem studies have shown an important increase in DMT1 levels in the SN of patients with PD. Our aim is to determine whether there is an association between DMT1 polymorphisms and PD. We analyzed two single nucleotide polymorphisms (1254T>C and IVS4+44C>A) in the DMT1 gene in patients with 97 Parkinson's disease and in 100 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). No association was found between the IVS4+44C>A polymorphism and PD, but the TT genotype and T allele of the 1254T>C polymorphism in the DMT1 gene were associated with PD (P=0.002 and P=0.012, respectively). In contrast to a previous study, our results suggest that the TT genotype and T allele of the 1254T>C polymorphism may be a risk factor for PD. PMID:25817364

  17. Anesthetics lower Tc of a 2D miscibility critical point in the plasma membrane

    NASA Astrophysics Data System (ADS)

    Machta, Benjamin; Gray, Elly; Veatch, Sarah

    2014-03-01

    Many small hydrophobic molecules induce general anesthesia. Their efficacy as anesthetics has been shown to correlate both with their hydrophobicity and with their potency in inhibiting certain ligand gated ion channels. I will first report on our experiments on the effects that these molecules have on the two-dimensional miscibility critical point observed in cell derived vesicles (GPMVs). We show that anesthetics depress the critical temperature (Tc) of these GPMVs but do not strongly affect the ratio of phases found below Tc. The magnitude of this affect is consistent across the n-alcohols only when their concentration is rescaled by the median anesthetic concentration (AC50) for tadpole anesthesia and at AC50 we see a 4K downward shift in Tc. I will next present a model in which anesthetics interfere with native allosteric regulation of ligand gated channels by the critical membrane, showing that our observed change in critical properties could lead to the previously observed changes in channel conductance without a direct interaction between anesthetic molecules and their target proteins. Finally, I will discuss ongoing experiments that will clarify the role of this membrane effect in mediating the organism level anesthetic response.

  18. Blood cell labeling with sup 99m Tc: Progress and perspectives

    SciTech Connect

    Srivastava, S.C.; Straub, R.F. )

    1990-01-01

    Blood cell labeling with {sup 99m}Tc has progressed through various developmental phases. In the case of red cell labeling, the science seems to have matured sufficiently, although minor refinements in the procedures will no doubt continue to be made. During the last 3 to 5 years, there has been a resurgence of interest in labeling leukocytes and platelets with {sup 99m}Tc. As a result of these efforts, the techniques for these cell types appear to be developing slowly, having finally come out of their infancy. Progress in these directions over the last 3 1/2 years is summarized and discussed in this article. Emerging techniques that offer the promise of combining simplicity and convenience with reliable and reproducible data are highlighted. Mechanisms involved in the various labeling approaches, if studied and understood, are included. Recent efforts on cell labeling with {sup 99m}Tc using the monoclonal antibody approach are summarized. Although results in this area are quite preliminary, the monoclonal antibody approach holds the greatest promise for labeling leukocytes and platelets in vivo, and thus overcoming the biggest drawback of current techniques, ie, cell separation and handling before labeling. 78 references.

  19. Quantitative evaluation of bile diversion surgery utilizing /sup 99m/Tc HIDA scintigraphy

    SciTech Connect

    Wickremesinghe, P.C.; Dayrit, P.Q.; Manfredi, O.L.; Fazio, R.A.; Fagel, V.L.

    1983-02-01

    This is a report of 21 patients presenting with epigastric pain, bilious vomiting, upper gastrointestinal bleeding, iron-deficiency anemia, and weight loss, who had undergone Billroth II gastrectomy from 3 to 35 yr earlier. Eighteen of 21 patients were found to have significant enterogastric reflux indices varying from 60% to 95% demonstrated by /sup 99m/Tc HIDA scintigraphy. Thirteen patients had diversion antireflux surgery in the form of a Roux-en-Y procedure, and 1 patient had a Henley loop jejunal interposition. Postoperative /sup 99m/Tc HIDA scintigraphic studies showed the enterogastric reflux indices to have decreased significantly to a range of 2%-26% (p less than 0.00001). There was marked improvement of symptoms, including correction of anemia and weight gain in those patients who had been anemic or who had sustained earlier weight loss. The enterogastric reflux indices of 10 asymptomatic control patients after Billroth II gastrectomy ranged from 4% to 45%. /sup 99m/Tc HIDA scintigraphy is useful in evaluating patients before and after bile diversion surgery, and demonstrates the quantitative decrease in enterogastric reflux after such surgery.

  20. Quantitative evaluation of bile diversion surgery utilizing 99mTc HIDA scintigraphy.

    PubMed

    Wickremesinghe, P C; Dayrit, P Q; Manfredi, O L; Fazio, R A; Fagel, V L

    1983-02-01

    This is a report of 21 patients presenting with epigastric pain, bilious vomiting, upper gastrointestinal bleeding, iron-deficiency anemia, and weight loss, who had undergone Billroth II gastrectomy from 3 to 35 yr earlier. Eighteen of 21 patients were found to have significant enterogastric reflux indices varying from 60% to 95% demonstrated by 99mTc HIDA scintigraphy. Thirteen patients had diversion antireflux surgery in the form of a Roux-en-Y procedure, and 1 patient had a Henley loop jejunal interposition. Postoperative 99mTc HIDA scintigraphic studies showed the enterogastric reflux indices to have decreased significantly to a range of 2%-26% (p less than 0.00001). There was marked improvement of symptoms, including correction of anemia and weight gain in those patients who had been anemic or who had sustained earlier weight loss. The enterogastric reflux indices of 10 asymptomatic control patients after Billroth II gastrectomy ranged from 4% to 45%. 99mTc HIDA scintigraphy is useful in evaluating patients before and after bile diversion surgery, and demonstrates the quantitative decrease in enterogastric reflux after such surgery. PMID:6600225

  1. Strong damping of the c-axis plasmon in high- Tc cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Kim, Jae H.; Somal, H. S.; Czyzyk, M. T.; van der Marel, D.; Wittlin, A.; Gerrits, A. M.; Duijn, V. H. M.; Hien, N. T.; Menovsky, A. A.

    1995-02-01

    We analyze the infrared reflectivity of La 1.85Sr 0.15CuO 4 single crystals with E parallel to the c-axis. The plasma edge at around 6 meV (50 cm -1), which occurs only for T < Tc, is due to Cooper-pair tunneling. This low value of the plasma edge is shown to be consistent with the c-axis plasma frequency obtained from LDA band structure calculations (> 0.1 eV) if we take into account that the single-particle charge transport along the c-axis is strongly incoherent in the normal state, and remains so in the superconducting state. From a comparison of the optical conductivity with model calculations based on s- and d-wave weak-coupling theory in the dirty limit, we find no evidence for a reduction of the c-axis quasi-particle scattering rate below Tc. The c-axis scattering rate, the normal-state c-axis plasma frequency, and Tc obey h? > h?p ? 3.5 ?BTc, which is exactly opposite to the clean limit.

  2. New crystal structure and physical properties of TcB from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Zhang, Gang-Tai; Bai, Ting-Ting; Yan, Hai-Yan; Zhao, Ya-Ru

    2015-10-01

    By combining first-principles calculations with the particle swarm optimization algorithm, we predicted a hexagonal structure for TcB, which is energetically more favorable than the previously reported WC-type and Cmcm structures. The new phase is mechanically and dynamically stable, as confirmed by its phonon and elastic constants calculations. The calculated mechanical properties show that it is an ultra-incompressible and hard material. Meanwhile, the elastic anisotropy is investigated by the shear anisotropic factors and ratio of the directional bulk modulus. Density of states analysis reveals that the strong covalent bonding between Tc and B atoms plays a leading role in forming a hard material. Additionally, the compressibility, bulk modulus, Debye temperature, Grüneisen parameter, specific heat, and thermal expansion coefficient of TcB are also successfully obtained by using the quasi-harmonic Debye model. Project supported by the Science Foundation of Baoji University of Arts and Sciences of China (Grant No. ZK11061) and the Natural Science Foundation of the Education Committee of Shaanxi Province, China (Grant Nos. 2013JK0637, 2013JK0638, and 2014JK1044).

  3. 15. Structure and Evolution of TC Warm Core Module Principal Investigators: Kelly Ryan, Klaus Dolling, and Jason Dunion

    E-print Network

    Dolling, and Jason Dunion Significance and Background: Forecasting TC intensity continues-level divergence. In an analysis on the evolution of Hurricane Humberto, Dolling and Barnes (2012, 2014) discovered

  4. Estudio de NIH señala relación de la TC en la infancia con leucemia y cáncer de cerebro más tarde

    Cancer.gov

    Niños y adultos jóvenes a quienes se les hicieron exploraciones muchas veces con tomografía computarizada (TC), una herramienta de diagnóstico de uso frecuente, tienen un riesgo ligeramente mayor de padecer leucemia y tumores cerebrales en la década poste

  5. Theoretical study of correlation between spin fluctuations and Tc in isovalent-doped 1111 iron-based superconductors

    NASA Astrophysics Data System (ADS)

    Arai, Hayato; Usui, Hidetomo; Suzuki, Katsuhiro; Fuseya, Yuki; Kuroki, Kazuhiko

    2015-04-01

    Motivated by recent experiments on isovalent-doped 1111 iron-based superconductors LaFeAs1-xPxO1-yFy and the theoretical study that followed, we investigate, within the five-orbital model, the correlation between spin fluctuations and the superconducting transition temperature, which exhibits a double-dome feature upon varying the Fe-As-Fe bond angle. Around the first dome with higher Tc, the low-energy spin fluctuation and Tc are not tightly correlated because the finite-energy spin fluctuation also contributes to superconductivity. On the other hand, the strength of the low-energy spin fluctuation originating from the dx z /y z orbital is correlated with Tc in the second dome with lower Tc. These calculation results are consistent with a recent NMR study, and hence strongly suggest that the pairing in iron-based superconductors is predominantly caused by multiorbital spin fluctuations.

  6. 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

  7. Development of tungsten-tantalum generator

    NASA Technical Reports Server (NTRS)

    Leblanc, A.; Babich, J.; Jhingran, S. G.

    1985-01-01

    The purpose of this project was to develop a useable tungsten (W)/tantalum (Ta) generator. Ta-178 is formed following the decay of its parent, W-178 (half-life: 21.7d) and has a half life of 9.3 minutes in turn yielding stable Hf-178. The decay of the parent isotope (W-178) occurs entirely by electron capture to the 9.3 minute Ta-178 state, without feeding the high spin Ta-178 isomer (half life 2.2 hours). In Ta-178 decay, 99.2% of the disintegrations proceed by electron capture and 0.18% by positron emission. Electron capture results in a 61.2% branch to the ground state of Hf-178 and 33.7% to the first excited state at 93 1KeV. The most prominent features of the radionuclide's energy spectrum are the hafnium characteristic radiation peaks with energies between 54.6 and 65.0 KeV. The radiation exposure dose of Ta-118 was calculated to be approximately one-twentieth that of Tc-99m on a per millicurie basis. A twenty-fold reduction in radiation exposure from Ta-178 compared with Tc-99m means that the usual administered dose can be increased three or four times, greatly increasing statistical accuracy while reducing radiation exposure by a factor of five.

  8. 76 FR 34692 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC, Dunkirk Power LLC, Huntley Power LLC, Oswego Harbor Power LLC, TC Ravenswood, LLC; v. New York...

  9. 76 FR 36910 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC, Dunkirk Power LLC, Huntley Power LLC, Oswego Harbor Power LLC, TC Ravenswood, LLC. v. New York...

  10. 76 FR 36914 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC, Dunkirk Power LLC, Huntley Power LLC, Oswego Harbor Power LLC, TC Ravenswood, LLC, v. New York...

  11. The discovery of robust magnetism in a technetium oxide: The structure of CaTcO3

    SciTech Connect

    Avdeev, Maxim; Thorogood, Gordon J.; Carter, Melody L.; Kennedy, Brendan J.; Ting, Jimmy; Singh, David J; Wallwork, Kia S.

    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.

  12. The GADD45A (1506T>C) Polymorphism Is Associated with Ovarian Cancer Susceptibility and Prognosis

    PubMed Central

    Yuan, Cunzhong; Liu, Xiaoyan; Liu, Xiaolin; Yang, Ning; Liu, Zhenping; Yan, Shi; Shen, Keng; Kong, Beihua

    2015-01-01

    GADD45A (growth arrest and DNA damage 45 A) is the first stress-inducible gene identified to be a target of p53. However, no studies to date have assessed variants of the GADD45 gene and their potential relationship to tumor susceptibility. We investigated the association of the GADD45A (1506T>C) polymorphism with ovarian cancer development in 258 ovarian cancer patients and 332 age-matched healthy women as controls using sequence analysis. We found a statistically significant difference in the GADD45A (1506T>C) genotype distributions between the case and control groups (TT vs. TC vs. CC, P = 0.0021) and found that variant 1506T>C was significantly associated with an increased risk of ovarian cancer (P<0.001, OR = 1.71, 95% CI [1.28–2.29]). We observed a statistically significant effect between tumor histology (P = 0.032) and CA125 status (P = 0.021). Carrying the C allele (TC+CC) was associated with an increased risk of positive CA125 (OR = 3.20, 95% CI [1.15–8.71). Carrying the T allele (TT+TC) showed a significant correlation with both higher GADD45A mRNA expression and longer ovarian cancer RFS (relapse-free survival) and OS (overall survival). We are the first group to demonstrate that the GADD45A (1506T>C) polymorphism is associated with ovarian cancer susceptibility and prognosis. These data suggest that GADD45A (1506T>C) is a new tumor susceptibility gene and could be a useful molecular marker for assessing ovarian cancer risk and for predicting ovarian cancer patient prognosis. PMID:26422378

  13. The usefulness of 99mTc-hexamethylpropyleneamineoxime white blood cell scintigraphy in a patient with eosinophilic gastroenteritis.

    PubMed

    Imai, Erika; Kaminaga, Tatsuro; Kawasugi, Kazuo; Yokokawa, Tokuzo; Furui, Shigeru

    2003-10-01

    White blood cell (WBC) 99mTc-hexamethylpropyleneamineoxime (HMPAO) scintigraphy was performed in a patient with eosinophilic gastroenteritis. WBC accumulation was detected in the terminal ileum to descending colon, and pathological studies demonstrated eosinophilic infiltration at the same region. 99mTc-HMPAO-WBC scintigraphy was proved to be a useful tool for the detection of eosinophilic infiltration in eosinophilic gastroenteritis. PMID:14651361

  14. 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.

  15. Assessing the Potential for In Situ Bioimmobilization of {sup 99}Tc at the Hanford Site

    SciTech Connect

    Long, Philip E.; Fredrickson, James K.; Gihring, Thomas M.; Shu-mei W. Li; Plymale, Andres E.; Zachara, John M.

    2004-03-17

    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. {sup 99}Tc is a radionuclide that contributes significantly to estimates of future human health risk at the Hanford Site because of its longevity and mobility in the subsurface environment. It exists at high concentrations (up to 30,000 pCi/L) in the central areas of the site where the groundwater table is deep, and is predicted to move to the Columbia River within the next decade. It also has been observed at lower concentrations (600 pCi/L) in shallow groundwater near the river in the 100 H area. The purpose of this project is to assess the feasibility of stimulating the in situ subsurface microbiota at the Hanford Site to reduce and immobilize {sup 99}Tc. The concept and approach proposed has evolved from NABIR-funded research that is maturing to the point that it is now appropriate to pursue site-specific research to establish field-scale proof-of-concept. Although this project focuses on assessment of biostimulation approaches for reducing and immobilizing {sup 99}Tc in the shallow groundwater system of the 100 H area at the Hanford Site, it is anticipated that the information will be applicable to other contaminants and site conditions at Hanford, and possibly elsewhere, within the DOE weapons production complex. The initial objective of the project is to determine if indigenous microorganisms in aquifer sediments at Hanford can be stimulated to either directly or indirectly, via Fe(II), immobilize {sup 99}Tc. If this is shown to be the case, two additional objectives will be addressed: (1) Devise an electron donor addition strategy for stimulating indigenous microorganisms to immobilize {sup 99}Tc in situ, and (2) Evaluate the feasibility and develop a research plan including design parameters, if warranted, for an in situ biostimulation experiment at the Hanford Site.

  16. Smoke generator

    NASA Technical Reports Server (NTRS)

    Rogers, J. R. (inventor)

    1976-01-01

    A smoke generator is disclosed which is particularly suitable for mounting on the wing tips of an aircraft and for conducting airflow studies. The device includes a network of thermally insulated tubes for carrying a fluid which is used to produce smoke. The fluid, which need not be combustible, is heated above its vaporization temperature by electric current which is passed through the fluid conduit tubes, so that the tubes serve both as fluid conduits and resistance heating elements. Fluid supply and monitoring systems and electrical control systems are also disclosed.

  17. 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.

  18. Piezoelectrostatic generator

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A. (inventor)

    1990-01-01

    A piezoelectrostatic generator includes a plurality of elongated piezoelectric elements having first and second ends, with the first ends fixedly mounted in a cylindrical housing and the second extending radially inwardly toward an axis. A shaft movable along the axis is connected to the inner ends of the elements to produce bending forces in piezoelectric strips within the elements. Each element includes a pair of strips mounted in surface contact and in electrical series to produce a potential upon bending. Electrodes spaced from the strips by a solid dielectric material act as capacitor plates to collect the potential charge.

  19. New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

    SciTech Connect

    Rogers, R.D.; Bond, A.H.; Zhang, Jianhua; Horwitz, P.

    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. Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by analytical characterization of radiopharmaceutical mixtures. Progress report, May 1, 1980-April 30, 1981. [/sup 99m/Tc(NaBH/sub 4/)HEDP

    SciTech Connect

    Heineman, W. R.; Deutsch, E. A.

    1980-12-01

    High performance liquid chromatography (HPLC) was used to efficiently separate and detect the individual components in a radiopharmaceutical mixture. A procedure for separating Tc(NaBH/sub 4/)HEDP radiopharmaceutical analogues by anion exchange HPLC with uv-visible and ..gamma.. detection was developed. Such preparations consist of as many as 7 Tc-containing components, the relative quantities of which are highly dependent on the conditions during preparation and subsequent handling. The in vivo distributions of 3 of the isolated Tc-HEDP species were evaluated as skeletal imaging agents in normal rats. The chromatographically separated Tc-HEDP components exhibit distinctly different biodistributions which are related to the chromatographic characteristics of the individual components. These same Tc-HEDP components were evaluated for uptake in myocardial infarcts using the isoproterenol-induced necrosis model in the rat. The relative uptake of the various components in the infarcted heart parallels the skeletal uptake. An optically transparent thin layer electrochemical flow cell was developed and characterized. This cell enables optical and electrochemical measurements to be made simultaneously on individual Tc-HEDP complexes as they elute from the HPLC. These results demonstrate the potential presence of numerous technetium complexes in radiopharmaceuticals and the efficacy of HPLC as a mode of separation and detection of these complexes. One particular component in the Tc(NaBH/sub 4/)HEDP radiopharmaceutical analogue is more effective than the others for both skeletal and myocardial infarct uptake. This is strongly suggestive that a more efficacious radiopharmaceutical would result from the administration of this single component.

  1. Triboelectric generator

    DOEpatents

    Wang, Zhong L; Fan, Fengru; Lin, Long; Zhu, Guang; Pan, Caofeng; Zhou, Yusheng

    2015-11-03

    A generator includes a thin first contact charging layer and a thin second contact charging layer. The thin first contact charging layer includes a first material that has a first rating on a triboelectric series. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer includes a second material that has a second rating on a triboelectric series that is more negative than the first rating. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer is disposed adjacent to the first contact charging layer so that the second side of the second contact charging layer is in contact with the second side of the first contact charging layer.

  2. Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

    SciTech Connect

    Strom, Daniel J.

    2003-09-30

    It is well-known that the human thyroid concentrates iodine more than 100 times the concentration in plasma. Also well-known is the fact that large amounts of stable iodine in the diet can limit thyroid uptake of total iodine; this is the basis for administering potassium iodide following a release of radioiodine from a nuclear reactor accident or nuclear weapon detonation. Many researchers have shown enhanced concentrations of both organic and inorganic iodine in saliva and breast milk. Technetium-99 is a long-lived (231,000 year half-life) radionuclide of concern in the management of high-level radioactive waste. There is no doubt that 99Tc, if it is in groundwater, will be found in the chemical form of pertechnetate, 99TcO4?. Pertechnetate is a large anion, almost identical in size to iodide, I?. The nuclear medicine literature shows that pertechnetate concentrates in the thyroid, salivary glands, and lactating breast in addition to the stomach, liver, and alimentary tract as currently recognized by the International Commission on Radiological Protection (ICRP). The fact that large intakes of stable iodine (127I) in the diet limit uptake of iodine by the thyroid leads one to generalize that stable iodine in the diet may also limit thyroid uptake of pertechnetate. While there is at least one report that iodine in the diet blocks uptake of 99mTcO4? by the thyroid and salivary glands (which have the same Na/I symporter, the biochemical concentration mechanism), the level of protective effect seen for blocking radioactive iodine is not expected for 99TcO4? because pertechnetate does not become organically bound in the thyroid and thus is not retained for months the way iodide is. While it does account for Tc concentration in the thyroid, the existing ICRP biokinetic model for technetium does not take enhanced concentrations in salivary gland and breast tissue into account. From the survey of the nuclear medicine literature, it is not possible to compute the effect of stable iodine in the diet on the dose per unit intake factors for 99Tc without developing an improved biokinetic model for technetium. Specific experiments should be designed to quantitatively evaluate 99TcO4? metabolism, excretion, and secretion, as well as to evaluate its chemical toxicity It is recommended that the ICRP reexamine its biokinetics models for Tc based on nuclear medicine data that have accumulated over the years. In particular, the ICRP ignores the lactation pathway, the enhanced concentration of Tc in breast and breast milk, and enhanced concentration of Tc (and I) in the salivary glands as well as in the thyroid. The ICRP should also explicitly incorporate the effect of stable iodine in the diet into both its models for iodine and technetium. The effect of concentration of Tc in breast milk needs further study for dosimetric implications to nursing infants whose mothers may ingest 99TcO4? from groundwater sources. The ICRP should also investigate the possibility of enhanced concentration of both I and Tc in the non-lactating female breast. To do these re-evaluations of biokinetic models, new experiments designed specifically to evaluate these questions concerning the biokinetics of Tc and I are needed.

  3. Predictive Models for Regional Hepatic Function Based on 99mTc-IDA SPECT and Local Radiation Dose for Physiologic Adaptive Radiation Therapy

    SciTech Connect

    Wang, Hesheng; Feng, Mary; Frey, Kirk A.; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2013-08-01

    Purpose: High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Methods and Materials: Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose–response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. Results: The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=?0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001). Conclusions: 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage.

  4. Predictive Models for Regional Hepatic Function Based upon 99mTc-IDA SPECT and Local Radiation Dose for Physiological Adaptive RT

    PubMed Central

    Wang, Hesheng; Feng, Mary; Frey, Kirk A.; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2013-01-01

    Purpose High dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed prior to and during the course of RT using 99mTc-labeled immindodiacetic acid (IDA) SPECT could predict regional liver function reserve after RT. Methods and Materials Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans prior to RT, during, and one month after completion of RT. Indocyanine green (ICG) tests (a measure of overall liver function) were performed within 1 day of each scan. 3D volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After co-registration of the CT/SPECT and the treatment planning CT, HEF dose-response functions during and post-RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, Dose, Priori and Adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function post-RT. Results The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r = ?0.80, p<0.0001), for all time points. Linear correlations between local doses and regional HEFs one month post-RT were significant in 12 patients. In the priori model, regional HEF post-RT was predicted by the planned dose and regional HEF assessed prior to RT (R=0.71, p<0.0001). In the adaptive model, regional HEF post-RT was predicted by regional HEF re-assessed during RT and the remaining planned local dose (R=0.83, p<0.0001). Conclusions 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage. PMID:23688813

  5. Development of Kit Formulations for 99mTcN-MPO: A Cationic Radiotracer for Myocardial Perfusion Imaging

    PubMed Central

    Zheng, Yumin; Ji, Shundong; Tomaselli, Elena; Liu, Shuang

    2015-01-01

    The objective of this study was to develop a kit formulation for 99mTcN-MPO to support its clinical evaluations as a SPECT radiotracer. Radiolabeling studies were performed using three different formulations (two-vial formulation and single-vial formulations with/without SnCl2) to explore the factors influencing radiochemical purity (RCP) of 99mTcN-MPO. We found that the most important factor affecting the RCP of 99mTcN-MPO was the purity of PNP5. 99mTcN-MPO was prepared >98% RCP (n = 20) using the two-vial formulation. For single-vial formulations with/without SnCl2, ?-cyclodextrin (?-CD) is particularly useful as a stabilizer for PNP5. The RCP of 99mTcN-MPO was 95 – 98% using ?-CD, but its RCP was only 90 – 93% with ?-CD. It seems that PNP5 fits better into the inner cavity of ?-CD, which forms more stable inclusion complex than ?-CD in the single-vial formulations. The results from biodistribution and imaging studies in Sprague-Dawley (SD) rats clearly demonstrated biological equivalence of three different formulations. SPECT data suggested that high quality images could be obtained at 0 – 30 min post-injection without significant interference from the liver radioactivity. Considering the ease for 99mTc-labeling and high RCP of 99mTcN-MPO, the non-SnCl2 single-vial formulation is an attractive choice for future clinical studies. PMID:25070025

  6. Neuroblastoma: Imaging evaluation by sequential Tc-99m MDP, I-131 MIBG, and Ga-67 citrate studies

    SciTech Connect

    Garty, I.; Friedman, A.; Sandler, M.P.; Kedar, A. )

    1989-07-01

    Fourteen children with histopathologically confirmed neuroblastoma underwent sequential correlative imaging studies using I-131 MIBG, Tc-99m MDP, and Ga-67 citrate during various stages of the disease. Of the patients 86% showed I-131 MIBG accumulation in the primary tumoral site, whereas 71% showed Tc-99m MDP and 79% Ga-67 citrate uptake. In 86% at least one of the two latter radiopharmaceuticals concentrated in the primary tumor. The use of all three radiopharmaceuticals raised the detection rate to 93%. Of the osseous or extraosseous metastases 100% were detected by Tc-99m MDP studies. The I-131 MIBG studies were positive in 71% of the osseous metastases and in 70% of the extraosseous metastases. No Ga-67 citrate uptake was demonstrated in osseous metastases, although one extraosseous lung metastasis concentrated this radiopharmaceutical. Tc-99m MDP bone imaging was the best method for diagnosing metastatic spread of the disease and for monitoring the results of treatment. Primary tumor uptake was best indicated by I-131 MIBG. Both Ga-67 citrate and I-131 MIBG were superior to Tc-99m MDP with regard to accurately demonstrating the extent of primary tumors. Only Tc-99m MDP indicated the relationship of these tumors to the kidneys and neighboring osseous structures, providing early screening of kidney compression. Ga-67 citrate study was mainly indicated in tumors with catecholamine depletion, which failed to concentrate the other two radiopharmaceuticals. I-131 MIBG proved especially useful in detecting neuroblastoma with negative Tc-99m MDP and Ga-67 citrate studies and also proved to be helpful with those cases in which I-131 MIBG was planned for therapy. The following strategy is suggested for evaluating neuroblastoma.

  7. A Randomized Exploratory Trial of an Alpha-7 Nicotinic Receptor Agonist (TC-5619) for Cognitive Enhancement in Schizophrenia

    PubMed Central

    Lieberman, Jeffrey A; Dunbar, Geoffrey; Segreti, Anthony C; Girgis, Ragy R; Seoane, Frances; Beaver, Jessica S; Duan, Naihua; Hosford, David A

    2013-01-01

    This exploratory trial was conducted to test the effects of an alpha7 nicotinic receptor partial agonist, TC-5619, on cognitive dysfunction and negative symptoms in subjects with schizophrenia. In the United States and India, 185 outpatients (18–60 years; male 69% 46% tobacco users) with schizophrenia treated with quetiapine or risperidone monotherapy were randomized to 12 weeks of placebo (n=91) or TC-5619 (n=94; orally once daily 1?mg day 1 to week 4, 5?mg week 4 to 8, and 25?mg week 8 to 12). The primary efficacy outcome measure was the Groton Maze Learning Task (GMLT; executive function) of the CogState Schizophrenia Battery (CSB). Secondary outcome measures included: CSB composite score; Scale for Assessment of Negative Symptoms (SANS); Clinical Global Impression-Global Improvement (CGI-I); CGI-severity (CGI-S); and Subject Global Impression-Cognition. GMLT statistically favored TC-5619 (P=0.036) in this exploratory trial. SANS also statistically favored TC-5619 (P=0.030). No other secondary outcome measure demonstrated a drug effect in the total population; there was a statistically significant drug effect on working memory in tobacco users. The results were typically stronger in favor of TC-5619 in tobacco users and occasionally better in the United States than in India. TC-5619 was generally well tolerated with no clinically noteworthy safety findings. These results support the potential benefits of TC-5619 and alpha7 nicotinic receptor partial agonists for cognitive dysfunction and negative symptoms in schizophrenia. PMID:23303043

  8. The effect of reperfusion and hyperemia on the biodistribution of the myocardial imaging agent, Tc-99m TBI

    SciTech Connect

    Holman, B.L.; Campbell, C.I.; Lister-James, J.; Jones, A.G.; Kloner, R.A.

    1985-05-01

    The behavior of Tc-99m t-butylisonitrile (TBI) was studied in the dog at rest and under conditions of hyperemia and reperfusion. After permanent occlusion of the left anterior descending artery (LAD), the correlation between the relative myocardial concentration of Tc-99m TBI and regional myocardial blood flow (MBF) was excellent (y=0.97x-1.03 (r=0.98)). In a dog model of transient hyperemia, Tc-99m TBI underestimated MBF (53 +- 10% at 3.0 +- 0.2 times normal flow and 41 +- 10% at 6.1 +- 4 times normal flow). When Tc-99m TBI was injected 3 min before reperfusion of the LAD in dogs sacrificed 10, 30 and 60 min after reperfusion, TBI and T1-201 concentrations (as a percentage of concentration in normal tissue) were 75% and 65% at 10 min after reperfusion; 79% and 73% at 30 min; and 38% and 31% at 60 min in regions where flow was reduced to 38%, 15% and 10% of normal MBF prior to reperfusion. There was no significant reduction in the rate of reperfusion when Tc-99m TBI was injected 10 min prior to reperfusion. When TBI was injected directly into the canine LAD, washout was slow (86% of maximum at 50 min and 79% at 120 min after injection. The authors conclude that Tc-99m TBI reflects regional MBF accurately in ischemic and normal resting myocardium and underestimates MBF at high values. The rate of myocardial redistribution for Tc-99m TBI after reperfusion in the animal model is similar to that for T1-201.

  9. The Instanton Molecule Liquid and "Sticky Molasses" Above T_c

    E-print Network

    G. E. Brown; C. -H. Lee; M. Rho; E. Shuryak

    2004-02-06

    The main objective of this work is to explore the evolution in the structure of the quark-antiquark bound states in going down in the chirally restored phase from the so-called "zero binding points" T_zb to the QCD critical temperature T_c at which the Nambu-Goldstone and Wigner-Weyl modes meet. In doing this, we adopt the idea recently introduced by Shuryak and Zahed for charmed $\\bar c c$, light-quark $\\bar q q$ mesons $\\pi, \\sigma, \\rho, A_1$ and gluons that at T_zb, the quark-antiquark scattering length goes through infinity at which conformal invariance is restored, thereby transforming the matter into a near perfect fluid behaving hydrodynamically, as found at RHIC. We show that the binding of these states is accomplished by the combination of (i) the color Coulomb interaction, (ii) the relativistic effects, and (iii) the interaction induced by the instanton-anti-instanton molecules. The spin-spin forces turned out to be small. While near T_zb all mesons are large-size nonrelativistic objects bound by Coulomb attraction, near T_c they get much more tightly bound, with many-body collective interactions becoming important and making the $\\sigma$ and $\\pi$ masses approach zero (in the chiral limit). The wave function at the origin grows strongly with binding, and the near-local four-Fermi interactions induced by the instanton molecules play an increasingly more important role as the temperature moves downward toward T_c.

  10. Transport of Aflatoxin M1 in Human Intestinal Caco-2/TC7 Cells

    PubMed Central

    Caloni, Francesca; Cortinovis, Cristina; Pizzo, Fabiola; De Angelis, Isabella

    2012-01-01

    Aflatoxin M1 (AFM1) is a hydroxylated metabolite of aflatoxin B1 (AFB1). After it is formed, it is secreted in the milk of mammals. Despite the potential risk of human exposure to AFM1, data reported in literature on the metabolism, toxicity, and bioavailability of this molecule are limited and out of date. The aim of the present research was to study the absorption profile of AFM1 and possible damage to tight junctions (TJ) of the intestinal Caco-2/TC7 clone grown on microporous filter supports. These inserts allowed for the separation of the apical and basolateral compartments which correspond to the in vivo lumen and the interstitial space/vascular systems of intestinal mucosa respectively. In this study, the Caco-2/TC7 cells were treated with different AFM1 concentrations (10–10,000?ng/kg) for short (40?min) and long periods of time (48?h). The AFM1 influx/efflux transport and effects on TJ were evaluated by measuring trans-epithelial electrical resistance and observing TJ protein (Zonula occludens-1 and occludin) localization. The results showed that: (i) when introduced to the apical and basolateral compartments, AFM1 was poorly absorbed by the Caco-2/TC7 cells but its transport across the cell monolayer occurred very quickly (Papp value of 105.10?±?7.98?cm/s?×?10?6). (ii) The integrity of TJ was not permanently compromised after exposure to the mycotoxin. Viability impairment or barrier damage did not occur either. The present results contribute to the evaluation of human risk exposure to AFM1, although the AFM1 transport mechanism need to be clarified. PMID:22701428

  11. Superfluid density of high- Tc cuprate systems: implication on condensation mechanisms, heterogeneity and phase diagram

    NASA Astrophysics Data System (ADS)

    Uemura, Y. J.

    2003-04-01

    Extensive muon spin relaxation ( ?SR) measurements have been performed to determine the magnetic field penetration depth ? in high Tc cuprate superconductors with simple hole doping, Zn-doping, overdoping, and formation of static SDW nano-islands. System dependence of n s/m ? (superconducting carrier density/effective mass) reveals universal correlations between Tc and n s/m ? in all these cases with/without perturbation. Evidence for spontaneous and microscopic phase separation into normal and superconducting regions was obtained in the cases with strong perturbation, i.e. Zn-doping (swiss cheese model), overdoping, and coexisting magnetic and superconducting states (SDW nano-islands). The length scale of this heterogeneity is shown to be comparable to the in-plane coherence length. We discuss implication of these results on condensation mechanisms of HTSC systems, resorting to an analogy with pure 4He and 4He/ 3He mixture films on regular and porous media, reminding essential features of Bose-Einstein, BCS and Kosterlitz-Thouless condensation/transition in 3-d and 2-d systems, and comparing models of BE-BCS crossover and phase fluctuations. Combining the ?SR results on n s/m ? and the pseudo-gap behavior, we propose a new phase diagram for HTSC, characterized by: (1) the T? line that represents pair formation; (2) disappearance of this line above the critical hole concentration x= xc; (3) in the underdoped region between Tc and T?, there exists another line Tdyn which corresponds to the onset of dynamic superconductivity with superconducting phase fluctuations; and (4) the overdoped region being phase separated between hole-poor superfluid and hole-rich normal fermion metal regions. Finally, we elucidate anomalous reduction of superfluid spectral weight in the crossover from superconducting to metallic ground states found not only in overdoped HTSC cuprates but also in pressurized organic BEDT and A 3C 60 fulleride superconductors.

  12. Optimizing Cr(VI) and Tc(VII) remediation through nano-scale biomineral engineering

    SciTech Connect

    Cutting, R. S.; Coker, V. S.; Telling, N. D.; Kimber, R. L.; Pearce, C. I.; Ellis, B.; Lawson, R; van der Laan, G.; Pattrick, R.A.D.; Vaughan, D.J.; Arenholz, E.; Lloyd, J. R.

    2009-09-09

    To optimize the production of biomagnetite for the bioremediation of metal oxyanion contaminated waters, the reduction of aqueous Cr(VI) to Cr(III) by two biogenic magnetites and a synthetic magnetite was evaluated under batch and continuous flow conditions. Results indicate that nano-scale biogenic magnetite produced by incubating synthetic schwertmannite powder in cell suspensions of Geobacter sulfurreducens is more efficient at reducing Cr(VI) than either biogenic nano-magnetite produced from a suspension of ferrihydrite 'gel' or synthetic nano-scale Fe{sub 3}O{sub 4} powder. Although X-ray Photoelectron Spectroscopy (XPS) measurements obtained from post-exposure magnetite samples reveal that both Cr(III) and Cr(VI) are associated with nanoparticle surfaces, X-ray Magnetic Circular Dichroism (XMCD) studies indicate that some Cr(III) has replaced octahedrally coordinated Fe in the lattice of the magnetite. Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) measurements of total aqueous Cr in the associated solution phase indicated that, although the majority of Cr(III) was incorporated within or adsorbed to the magnetite samples, a proportion ({approx}10-15 %) was released back into solution. Studies of Tc(VII) uptake by magnetites produced via the different synthesis routes also revealed significant differences between them as regards effectiveness for remediation. In addition, column studies using a {gamma}-camera to obtain real time images of a {sup 99m}Tc(VII) radiotracer were performed to visualize directly the relative performances of the magnetite sorbents against ultra-trace concentrations of metal oxyanion contaminants. Again, the magnetite produced from schwertmannite proved capable of retaining more ({approx}20%) {sup 99m}Tc(VII) than the magnetite produced from ferrihydrite, confirming that biomagnetite production for efficient environmental remediation can be fine-tuned through careful selection of the initial Fe(III) mineral substrate supplied to Fe(III)-reducing bacteria.

  13. Analysis of quasielastic light scattering in LiNbO3 near TC

    NASA Astrophysics Data System (ADS)

    Okamoto, Y.; Wang, Ping-Chu; Scott, J. F.

    1985-11-01

    We have performed Raman studies of lithium niobate from 293 to 1224 K with special emphasis upon quantitative analysis of the quasielastic scattering from 0-50 cm-1. We find that the complete spectrum, including both the quasielastic ``wing'' and the two lowest-frequency A1-symmetry optical phonons, can be fitted to the spectral distribution function predicted for a system with a relaxing self-energy; when this is done all the parameters fitted vary slowly and monotonically with temperature. The coupling parameter ?2(T) varies approximately as (TC-T)-1.4 in accord with the predictions of Halperin and Varma [Phys. Rev. B 14, 4030 (1976)]. This is only the second central-mode study to satisfy that defect-theory prediction. Both congruent and stoichiometric specimens were examined. The congruent sample exhibits an inverse relaxation time of 540+/-30 GHz that is independent of temperature; it is apparently limited by defects arising from the lack of stoichiometry. The stoichiometric sample exhibits a temperature-dependent relaxation time of the form ?-1(T)=?-10[(TC-T) /TC] with ?-10=1740+/-430 GHz (i.e., ?-10=58+/-14 cm-1); this is the expected mean-field dependence for a second-order phase transition. The data show why inelastic neutron scattering studies [e.g., M. R. Chowdhury, G. E. Peckham, and D. H. Saunderson, J. Phys. C 11, 1671 (1978)] may have been unable to detect the softening of the lowest A1-symmetry optical phonon and thereby help resolve a long-standing controversy concerning the qualitative disagreement of Raman and neutron scattering data.

  14. Comparative in vivo evaluation of two novel 99mTc labelled bombesin derivatives

    NASA Astrophysics Data System (ADS)

    Gourni, Eleni; Bouziotis, Penelope; Zikos, Christos; Loudos, George; Xanthopoulos, Stavros; Fani, Melpomeni; Archimandritis, Spyridon C.; Varvarigou, Alexandra D.

    2006-12-01

    Bombesin (BN), a 14 amino acid peptide, is an analogue of human gastrin-releasing-peptide (GRP) that binds to GRP receptors (GRP-R) with high affinity and specificity. In addition to this physiological role, GRP, through its interaction with GRP-R, promotes tumour growth in a number of human cancer cell lines. The GRP receptors are over-expressed on a variety of human cancer cells. Aim of the present work is the study of two novels BN-like peptides, by investigating the radiochemical and radiopharmacological behaviour of their complexes with metals. The derivatives under study are: Gly-Gly-Cys-Aca-BN [2-14] where Aca: 6-amino-hexanoic acid. Pyroglutamic acid in the bombesin molecule has been replaced by the chemical group Gly-Gly-Cys-Aca, which bears an amino-acid combination capable of complexing a variety of radiometals. The other derivative under study is: Gly-Gly-Cys-Aca-BN [7-14]. This moiety of the peptide has been chosen because it has been proven to be a potent GRP agonist. The peptide derivatives were synthesized by SPPS, according to the Fmoc strategy and were identified by reverse phase high performance liquid chromatography (RP-HPLC). Radiolabelling with 99mTc was performed via the precursor 99mTc-gluconate. The stability of the radiolabelled species was examined with time. In vivo studies of the two 99mTc-labelled derivatives were performed, comparatively, in normal mice, attention being focused on GRP receptor-bearing organs, and in experimentally induced prostate cancer models. Experimental tumours were imaged in a small field-of-view animal gamma camera.

  15. The \\bar q q Bound States and Instanton Molecule at T >~ T_c

    E-print Network

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

    2004-05-25

    The main objective of this work is to explore the evolution in the structure of the quark-anti-quark bound states in going down in the chirally restored phase from the so-called "zero binding points" $T_{zb}$ to the full (unquenched) QCD critical temperature $T_c$ at which the Nambu-Goldstone and Wigner-Weyl modes meet. In doing this, we adopt the idea recently introduced by Shuryak and Zahed for charmed $\\bar c c$, light-quark $\\bar q q$ mesons $\\pi, \\sigma, \\rho, A_1$ and gluons that at $T_{zb}$, the quark-anti-quark scattering length goes through $\\infty$ at which conformal invariance is restored, thereby transforming the matter into a near perfect fluid behaving hydrodynamically, as found at RHIC. We show that the binding of these states is accomplished by the combination of (i) the color Coulomb interaction, (ii) the relativistic effects, and (iii) the interaction induced by the instanton-anti-instanton molecules. The spin-spin forces turned out to be small. While near $T_{zb}$ all mesons are large-size nonrelativistic objects bound by Coulomb attraction, near $T_c$ they get much more tightly bound, with many-body collective interactions becoming important and making the $\\sigma$ and $\\pi$ masses approach zero (in the chiral limit). The wave function at the origin grows strongly with binding, and the near-local four-Fermi interactions induced by the instanton molecules play an increasingly more important role as the temperature moves downward toward $T_c$.

  16. Studies on the development of 99mTc-labeled biphosphonate alginate beads.

    PubMed

    Vishwakarma, Maya; Bandopadhyaya, Guru Pad

    2010-01-01

    The preparation of alginate-dextran pyrophosphate/biphosphonate loaded beads, were labeled with technetium-99m ((99m)Tc) and rhenium-188 ((188)Re). The radiolabelled phosphonic acid derivatives,are well-known bone imaging agents and have also been used for bone pain palliation treatment. The alginates have been used extensively as an excipient in drug products due to their thickening, gel forming and stabilizing behavior. The aim of this study was the preparation of alginate polymeric beads with and without dextran coating, to be used for imaging and possible treatment. We studied (99m)Tc-labelled biphosphonate alginates. We reported our results on the basis of size, swelling capacity and the coating material. The size effect of loading, decreases size and increases loading capacity of alginate beads. Pyrophosphate (PYP) loaded beads had 95% swelling, while ethylene diamine tetramethylene phosphonic acid (EDTMP) loaded beads had 90% (swelling). However combination of both (PYP+EDTMP) loaded beads had 95% swelling. Sustained drug release study indicated different ratios of EDTMP, PYP and EDTMP+PYP loaded beads on different days. Total drug extracted from 30 g beads was 1365.45 ?g, 5352.86 ?g and 711.8 ?g, from EDTMP, PYP and EDTMP+PYP respectively during 15 days of studies. Binding with PYP and EDTMP was 98% and 99% respectively. In conclusion, (chemical and physical characteristics of (99m)Tc-biphosphonate and other alginate beads that we have prepared suggest that the alginate beads could be used for diagnostic and therapeutic purposes.). PMID:21193874

  17. Accuracy of 99mTc-sestamibi scintimammography for breast cancer diagnosis

    PubMed Central

    MORIGUCHI, SONIA MARTA; DE LUCA, LAURIVAL ANTÔNIO; GRIVA, BEATRIZ LOTUFO; KOGA, KÁTIA HIROMOTO; DA SILVA, EDUARDO TINOIS; DE LUCA VESPOLI, HELOISA; UEMURA, GILBERTO

    2010-01-01

    Scintimammography using 99mTc-sestamibi is a noninvasive and painless diagnostic imaging method that is used to detect breast cancer when mammography is inconclusive. Because of the advantages of labeling with 99mTc-sestamibi and its high efficiency in detecting carcinomas, it is the most widespread agent for this purpose. Its accumulation in the tumor has multifactorial causes and does not depend on the presence of architectural distortion or local or diffuse density variation in the breast. The objective of this study was to evaluate the accuracy of scintimammography for detecting breast cancer. One hundred and fifty-seven patients presenting 158 palpable and non-palpable breast nodules were evaluated. Three patients were male and 154 were female, aged between 14 and 81 years. All patients underwent scintimammography, and the nodule was subjected to cytological or histological study, i.e., the gold standard for diagnosing cancer. One hundred and eleven malignant and 47 benign nodules were detected, with predominance of ductal carcinomas (n=94) and fibroadenoma/fibrocystic condition (n=11/n=11), respectively. The mean size was 3.11 cm (7–10 cm) among the malignant nodules and 2.07 cm among the benign nodules (0.5–10 cm). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 89, 89, 95, 78 and 89%, respectively. Analysis on the histological types showed that the technique was more effective on tumors that were more aggressive, such as ductal carcinoma. In this study, 99mTc-sestamibi scintimammography was shown to be an important tool for diagnosing breast cancer when mammography was inconclusive. PMID:23136616

  18. MERRF/MELAS overlap syndrome due to the m.3291T>C mutation.

    PubMed

    Liu, Kaiming; Zhao, Hui; Ji, Kunqian; Yan, Chuanzhu

    2014-03-01

    We report the case of a 19-year-old Chinese female harboring the m.3291T>C mutation in the MT-TL1 gene encoding the mitochondrial transfer RNA for leucine. She presented with a complex phenotype characterized by progressive cerebellar ataxia, frequent myoclonus seizures, recurrent stroke-like episodes, migraine-like headaches with nausea and vomiting, and elevated resting lactate blood level. It is known that the myoclonus epilepsy with ragged-red fibers (MERRF) is characterized by cerebellar ataxia and myoclonus epilepsy, while that the mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is characterized by recurrent stroke-like episodes, migraine-like headaches, and elevated resting lactate blood level. So the patient's clinical manifestations suggest the presence of a MERRF/MELAS overlap syndrome. Muscle biopsy of the patient showed the presence of numerous scattered ragged-red fibers, some cytochrome c oxidase-deficient fibers, and several strongly succinate dehygrogenase-reactive vessels, suggestive of a mitochondrial disorder. Direct sequencing of the complete mitochondrial genome of the proband revealed no mutations other than the T-to-C transition at nucleotide position 3291. Restriction fragment length polymorphism analysis of the proband and her family revealed maternal inheritance of the mutation in a heteroplasmic manner. The analysis of aerobic respiration and glycolysis demonstrated that the fibroblasts from the patient had mitochondrial dysfunction. Our results suggest that the m.3291T>C is pathogenic. This study is the first to describe the m.3291T>C mutation in association with the MERRF/MELAS overlap syndrome. PMID:24338029

  19. Power and magnetic field-induced microwave absorption in Tl-based high Tc superconducting films

    NASA Astrophysics Data System (ADS)

    Portis, A. M.; Cooke, D. W.; Gray, E. R.; Arendt, P. N.; Bohn, C. L.; Delayen, J. R.; Roche, C. T.; Hein, M.; Klein, N.; Müller, G.; Orbach, S.; Piel, H.

    1991-01-01

    The increase in the microwave surface resistance Rs of high Tc superconductors at elevated microwave power levels is reported for both oriented and unoriented Tl-based films as a function of rf magnetic field at 820 MHz and 18 GHz. The application of dc magnetic fields produces qualitatively similar increases in Rs and in the surface reactance Xs. The increase in Rs with dc field is shown to arise from simple decoupling of grains by intergranular magnetic flux. The increase in Rs with microwave power, on the other hand, is a consequence of hysteretic intergranular processes.

  20. (99m)Tc-HMDP scintigraphy rectifies wrong diagnosis of AL amyloidosis.

    PubMed

    Galat, Arnault; Van Der Gucht, Axel; Colombat, Magali; Attias, David; Itti, Emmanuel; Meignan, Michel; Lebras, Fabien; Molinier-Frenkel, Valérie; Benhaiem, Nicole; Guellich, Aziz; Rosso, Jean; Damy, Thibaud

    2015-08-01

    A 71-year-old African man without history of cardiac disease was referred to our center for dyspnea. Transthoracic echocardiogram and cardiac MRI were suggestive of cardiac amyloidosis (CA). The diagnosis of the light-chain cardiac amyloidosis (AL-CA) was made after a first endomyocardial biopsy. Accordingly chemotherapy was started. Systematic 99mTc-HMDP scintigraphy showed moderate cardiac uptake (visual score of 2), unusual for AL-CA, and permitted to rectify the diagnosis. Hereditary transthyretin cardiac amyloidosis was confirmed by a second endomyocardial biopsy with a positive Congo-red and anti-transthyretin antibody stainings, mass spectrometry and genetic analysis (Val122Ile mutation). PMID:26002815

  1. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  2. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.; Lee, Ja H.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  3. Evolution of the Tropical Cyclone Integrated Data Exchange And Analysis System (TC-IDEAS)

    NASA Technical Reports Server (NTRS)

    Turk, J.; Chao, Y.; Haddad, Z.; Hristova-Veleva, S.; Knosp, B.; Lambrigtsen, B.; Li, P.; Licata, S.; Poulsen, W.; Su, H.; Tanelli, S.; Vane, D.; Vu, Q.; Goodman, H. M.; Blakeslee, R.; Conover, H.; Hall, J.; He, Y.; Regner, K.; Knapp, Ken

    2010-01-01

    The Tropical Cyclone Integrated Data Exchange and Analysis System (TC-IDEAS) is being jointly developed by the Jet Propulsion Laboratory (JPL) and the Marshall Space Flight Center (MSFC) as part of NASA's Hurricane Science Research Program. The long-term goal is to create a comprehensive tropical cyclone database of satellite and airborne observations, in-situ measurements and model simulations containing parameters that pertain to the thermodynamic and microphysical structure of the storms; the air-sea interaction processes; and the large-scale environment.

  4. Spatially resolved assessment of hepatic function using 99mTc-IDA SPECT

    SciTech Connect

    Wang, Hesheng; Cao, Yue

    2013-09-15

    Purpose: 99mTc-iminodiacetic acid (IDA) hepatobiliary imaging is usually quantified for hepatic function on the entire liver or regions of interest (ROIs) in the liver. The authors presented a method to estimate the hepatic extraction fraction (HEF) voxel-by-voxel from single-photon emission computed tomography (SPECT)/CT with a 99mTc-labeled IDA agent of mebrofenin and evaluated the spatially resolved HEF measurements with an independent physiological measurement.Methods: Fourteen patients with intrahepatic cancers were treated with radiation therapy (RT) and imaged by 99mTc-mebrofenin SPECT before and 1 month after RT. The dynamic SPECT volumes were with a resolution of 3.9 × 3.9 × 2.5 mm{sup 3}. Throughout the whole liver with approximate 50 000 voxels, voxelwise HEF quantifications were estimated and compared between using arterial input function (AIF) from the heart and using vascular input function (VIF) from the spleen. The correlation between mean of the HEFs over the nontumor liver tissue and the overall liver function measured by Indocyanine green clearance half-time (T1/2) was assessed. Variation of the voxelwise estimation was evaluated in ROIs drawn in relatively homogeneous regions of the livers. The authors also examined effects of the time range parameter on the voxelwise HEF quantification.Results: Mean of the HEFs over the liver estimated using AIF significantly correlated with the physiological measurement T1/2 (r= 0.52, p= 0.0004), and the correlation was greatly improved by using VIF (r= 0.79, p < 0.0001). The parameter of time range for the retention phase did not lead to a significant difference in the means of the HEFs in the ROIs. Using VIF and a retention phase time range of 7–30 min, the relative variation of the voxelwise HEF in the ROIs was 10%± 6% of respective mean HEF.Conclusions: The voxelwise HEF derived from 99mTc-IDA SPECT by the deconvolution analysis is feasible to assess the spatial distribution of hepatic function in the liver.

  5. [99mTc-MAA peritoneal scintigraphy in pleuroperitoneal comunication in peritoneal dialysis patients].

    PubMed

    Hernández Martínez, A C; Marín Ferrer, M D; Coronado Poggio, M; Escabias Del Pozo, C; Coya Viña, J; Martín Curto, L

    2010-01-01

    Peritoneal dialysis is a fully-contrasted alternative for the treatment of end-stage renal disease although it is not exempt of complications. Peritonitis and exit-site infections are among the most frequent complications found. Pleural effusion secondary to pleuroperitoneal communication (PPC) is a serious and uncommon complication in these patients. We present the case of a 50-year old man diagnosed of end-stage renal disease undergoing treatment with peritoneal dialysis who presented progressive dyspnea and right pleural effusion. The peritoneal scintigraphy with (99m)Tc-MAA makes it possible to confirm communication of intraperitoneal dialysis fluid to the pleural cavity. PMID:20117860

  6. Theory of high-{Tc} superconducting cuprates based on experimental evidence

    SciTech Connect

    Abrikosov, A. A.

    1999-12-10

    A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of {Tc}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.

  7. 99mTc-HDP SPECT With CT Myelography in a 1-Step Procedure.

    PubMed

    Durante, Steve; Haller, Sven; Amzalag, Gaël; Tessitore, Enrico; Rager, Olivier

    2016-01-01

    We present the case of a 45-year-old woman with a history of multiple back surgeries to illustrate the feasibility of combining CT myelography (myeloCT) and Tc-HDP SPECT/CT bone scan in a 1-step procedure to realize a combined SPECT-myeloCT. Myelography CT and SPECT/CT were required to assess nerve root compression and pseudarthrosis, respectively. The proposed combined acquisition protocol provides information about nervous compression as well as pseudarthrosis in a 1 examination, optimizing radiation dose and patient comfort. PMID:26505857

  8. Soy-Based, Water-Cooled, TC W-III Two Cycle Engine Oil

    SciTech Connect

    Scharf, Curtis R.; Miller, Mark E.

    2003-08-30

    The objective of this project was to achieve technical approval and commercial launch for a biodegradable soy oil-based, environmentally safe, TC W-III performance, water-cooled, two cycle engine oil. To do so would: (1) develop a new use for RBD soybean oil; (2) increase soybean utilization in North America in the range of 500 K-3.0 MM bushels; and (3) open up supply opportunities of 1.5-5.0 MM bushels worldwide. These goals have been successfully obtained.

  9. [99mTc marking of gel foam for catheter embolisation (author's transl)].

    PubMed

    Endert, G; Ritter, H; Schumann, E

    1979-12-01

    A simple method is described for marking gel foam particles with 99mTc after reduction of the pertechnetate. This is carried out in the Luer lock syringe to be used for the injection. After embolisation and control angiography, the patient is placed under a scintillation camera. The position of the embolising material can then be demonstrated scintigraphically. In six patients marked emboli were found to be correctly placed. In another patient undergoing a second embolisation for a renal tumour, particles were found in the peripheral circulation. PMID:161885

  10. Position determine system for lymph node relating breast cancer using a high- Tc SQUID

    NASA Astrophysics Data System (ADS)

    Tanaka, Saburo; Ota, Hajime; Kondo, Yoichi; Tamaki, Yasuhiro; Noguchi, Shinzaburo; Hasegawa, Masakatsu

    2002-03-01

    The performance of a lymph-node detection system used with a high- Tc superconducting quantum interference device was investigated. Ultra-small iron oxide particles containing 360 pg in weight of iron could be detected at a distance of 1 mm using Helmholtz coils. When a pair of angled field coils, which were of a more practical design, were used this value was increased to 2.8 ng. This value is still large enough to apply the technique for sentinel-node biopsy and lymphatic mapping.

  11. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  12. Imaging Idiopathic Chylopericardium With 99mTc-SC Lymphoscintigraphy and SPECT/CT.

    PubMed

    Atkinson, Chris; Banks, Kevin

    2015-11-01

    A 27-year-old asymptomatic active duty military man underwent a screening chest x-ray secondary to a history of tuberculosis exposure. His chest x-ray showed no features of tuberculosis infection but unexpectedly revealed a markedly enlarged cardiac silhouette. Echocardiography demonstrated a large pericardial effusion without tamponade physiology. Pericardiocentesis revealed chylous fluid. The effusion was initially refractory to drainage requiring VATS for therapy. Lymphoscintigraphy was performed using Tc-SC to evaluate lymphatic anatomy and confirm communication with the pericardial space. Novel use was made of SPECT/CT with the hope of better assessing the nature of the abnormal communication and potentially helping guide management. PMID:26284770

  13. Development of a compact, lightweight, mobile permanent magnet system based on high Tc Gd-123 superconductors

    NASA Astrophysics Data System (ADS)

    Tomita, Masaru; Fukumoto, Yusuke; Suzuki, Kenji; Ishihara, Atsushi; Muralidhar, Miryala

    2011-01-01

    We have designed and fabricated a compact, lightweight, mobile permanent high-Tc superconducting magnet system using melt-processed GdBa2Cu3Oy rings. Magnetic field distribution inside the annular magnet reached 0.75 T to 2.65 T, for one to ten rings, respectively. The increasing number of rings enhanced magnetic field in the center position and caused the field to be flatter over the entire surface. Using this new permanent magnet, we successfully magnetized several melt-processed bulk samples at 77 K. Use of simple superconducting permanent magnet for magnetizing bulk melt-processed materials can open new technological windows in various industrial areas.

  14. Precision mass measurements of neutron-rich Tc, Ru, Rh, and Pd isotopes

    SciTech Connect

    Hager, U.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Kankainen, A.; Rahaman, S.; Rinta-Antila, S.; Saastamoinen, A.; Sonoda, T.; Aeystoe, J.

    2007-06-15

    The masses of neutron-rich {sup 106-112}Tc, {sup 106-115}Ru, {sup 108-118}Rh, and {sup 112-120}Pd produced in proton-induced fission of uranium were determined using the JYFLTRAP double Penning trap setup. The measured isotopic chains include a number of previously unmeasured nuclei. Typical precisions on the order of 10 keV or better were achieved, representing a factor of 10 improvement over earlier data. In many cases, significant deviations from the earlier measurements were found. The obtained data set of 39 masses is compared with different mass predictions and analyzed for global trends in the nuclear structure.

  15. [Evaluation of bone and soft tissue lesion using 99mTc-MIBI: comparison with 201Tl and the relation to chemotherapeutic effect].

    PubMed

    Sumiya, H; Taki, J; Tonami, N; Asada, N; Tsuchiya, H; Tomita, K

    1997-02-01

    Thirty-five patients with bone and soft tissue lesions were studied with 99mTc-MIBI and 201Tl to compare the uptake of two tracers. Planar images were obtained 15 min (early image) and 3 hr (delayed image) after the injection of both tracers. Images were evaluated visually and quantitatively using uptake ratio (lesion/background). In visual analysis, 23 of 35 patients showed similar uptake of both tracers, 9 showed more intense uptake of 99mTc-MIBI than 201Tl, and 3 showed more intense uptake of 201Tl than 99mTc-MIBI on early images. On delayed images, 21 of 32 patients showed similar uptake of both tracers, 3 showed more intense uptake of 99mTc-MIBI than 201Tl, and 8 showed more intense uptake of 201Tl than 99mTc-MIBI. In quantitative analysis, similar 201Tl and 99mTc-MIBI uptake ratios were obtained on early images. On delayed images, 99mTc-MIBI uptake ratios are less than that of 201Tl, but the difference was not significant. In some cases, 99mTc-MIBI accumulation was washed out on delayed images, therefore the early image is essential to evaluate 99mTc-MIBI accumulation. In all cases with the uptake ratios less than 1.20 on delayed 99mTc-MIBI images, chemotherapy was not effective. In malignant tumors, decreased uptake of 99mTc-MIBI accumulation on delayed images may indicate that chemotherapy is not effective. Delayed 99mTc-MIBI image may be a potential marker predicting chemotherapeutic effect in malignant bone and soft tissue tumors. PMID:9095573

  16. A Generator-Produced Gallium-68 Radiopharmaceutical for PET Imaging of Myocardial Perfusion

    PubMed Central

    Sharma, Vijay; Sivapackiam, Jothilingam; Harpstrite, Scott E.; Prior, Julie L.; Gu, Hannah; Rath, Nigam P.; Piwnica-Worms, David

    2014-01-01

    Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI. PMID:25353349

  17. Use of /sup 99m/Tc diethylenetriaminepentaacetic acid for assessment of renal function in dogs with suspected renal disease

    SciTech Connect

    Krawiec, D.R.; Twardock, A.R.; Badertscher, R.R. II; Daniel, G.B.; Dugan, S.J.

    1988-04-15

    The effectiveness of technetium /sup 99m/-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc DTPA) to assess renal function in 13 dogs with suspected renal disease was evaluated. Glomerular filtration rates (actual GFR) were determined on the basis of endogenous creatinine clearance. Predicted GFR were determined by using /sup 99m/Tc DTPA within 72 hours after the determination of creatinine clearance. The percentage of an IV administered dose of /sup 99m/Tc DTPA in the kidneys (percentage dose) was determined. Two equations were used to calculate predicted GFR, which were derived from previously reported linear regression analysis of inulin (In) and creatinine (Cr) GFR vs percentage dose /sup 99m/Tc DTPA in dog kidneys. The correlations of actual GFR vs predicted GFR (In) and actual GFR vs predicted GFR (Cr) were both r = 0.92. The dogs' mean actual GFR was 1.73 +/- 1.35 ml/min/kg. Their mean predicted GFR (In) and predicted GFR (Cr) were 1.92 +/- 1.42 ml/min/kg and 1.85 +/- 1.27 ml/min/kg, respectively. Therefore, /sup 99m/Tc DTPA can be used with high accuracy as an agent to predict GFR in dogs with suspected renal disease. The procedure for determining GFR by use of nuclear medicine was rapid and noninvasive and appeared to induce little stress in the animals evaluated.

  18. ACVR1 (587T>C) mutation in a variant form of fibrodysplasia ossificans progressiva: second report.

    PubMed

    Nakahara, Y; Katagiri, T; Ogata, N; Haga, N

    2014-01-01

    Fibrodysplasia ossificans progressiva (FOP) is a rare, congenital disorder caused by heterozygous mutation of the bone morphogenetic protein type I receptor ACVR1. Various forms of atypical FOP have recently been identified, and a novel mutation, ACVR1 (587T>C), was reported in 2011. We report on the second patient worldwide with ACVR1 (587T>C) mutation. A 22-year-old Japanese male with no family history of heterotopic ossification did not show any malformation of the great toes and showed normal development from birth to the age of 17 years, when heterotopic ossification appeared in the lumbar area. The clinical symptoms were similar to those reported previously: the delayed onset with a slower and mild clinical course and little finger camptodactyly. Gene analysis revealed that the patient was heterozygous for ACVR1 (587T>C) mutation, the same one as reported in 2011, suggesting a correlation between the location of the mutation and the clinical symptoms. This second report of ACVR1 (587T>C) mutation worldwide is particularly meaningful in that it highlights the difference between clinical symptoms of the first reported patient with ACVR1 (587T>C) mutation and those of classic FOP. PMID:24259422

  19. High Tc screen-printed YBa2Cu3O(7-x) films - Effect of the substrate material

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Simons, Rainee N.; Farrell, D. E.

    1988-01-01

    Thick films of YBa2Cu3O(7-x) have been deposited on highly polished alumina, magnesia spinel, nickel aluminum titanate (Ni-Al-Ti), and barium tetratitanate (Ba-Ti) substrates by the screen printing technique. Properties of the films were found to be highly sensitive to the choice of the substrate material. The film on Ba-Ti turned green after firing, due to a reaction with the substrate and were insulating. A film on Ni-Al-Ti had a Tc (onset) of about 95 K and lost 90 percent of its resistance by about 75 K. However, even at 4 K it was not fully superconducting, possibly due to a reaction between the film and the substrate and interdiffusion of the reaction products. The film on alumina had Tc (onset) of about 96 K, Tc (zero) of about 66 K, and Delta Tc of about 10 K. The best film was obtained on spinel and had Tc (onset) of about 94 K, zero resistance at 81 K, and a transition width of about 7 K.

  20. Preparation and stability of the sup 9 sup 9 sup m Tc-HNE sub 2 radiopharmaceutical

    E-print Network

    Estrada, J

    2002-01-01

    and acetone as eluent systems) at different time intervals in solutions of different cysteine concentration. These tests indicated the trans chelation grade of the sup 9 sup 9 sup m Tc metal. In the In vivo evaluations the stability of the sup 9 sup 9 sup m Tc-HNE-2 was obtained when it was realized the biodistribution in normal mice of the balb-c stock. The obtained results show a radiochemical purity of 95.05 % +- 2.81% for the sup 9 sup 9 sup m Tc-DTPA-HNE-2 conjugates and 51.45% +- 3.2% for sup 9 sup 9 sup m Tc-HYNIC-HNE-2 even as tricine as colligand was used. The In vivo and In vitro stability tests of the radio conjugates show that the radio complexes are keeping whole at least during 24 hours (In vitro) time in which passing for half life of the sup 9 sup 9 sup m Tc radionuclide and 30 min (In vivo). Since the radio conjugates prepared with DTPA were obtained with radiochemical purities adequate for its use in scintillography, it is necessary as a future work to realize the biodistribution kinetics as...

  1. RANK rs1805034 T>C Polymorphism Is Associated with Susceptibility of Esophageal Cancer in a Chinese Population

    PubMed Central

    Tang, Weifeng; Wang, Xu; Lv, Lu; Shao, Aizhong; Shi, Yijun; Ding, Guowen; Chen, Suocheng; Gu, Haiyong

    2014-01-01

    Esophageal cancer remains the sixth leading cause of cancer associated death and eighth most common cancer worldwide. Genetic factors, such as single nucleotide polymorphisms (SNPs), may contribute to the carcinogenesis of esophageal cancer. Here, we conducted a hospital based case-control study to evaluate the genetic susceptibility of functional SNPs on the development of esophageal cancer. A total of 629 esophageal squamous cell carcinoma (ESCC) cases and 686 controls were enrolled for this study. The OPG rs3102735 T>C, rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and rs2277438 A>G were determined by ligation detection reaction method. Our findings suggested that RANK rs1805034 T>C is associated with the susceptibility of ESCC, which is more evident in male and elder (?63) patients. Our study provides the first evidence that functional polymorphisms RANK rs1805034 T>C may be an indicator for individual susceptibility to ESCC. However, further larger studies among different ethnic populations are warranted to verify our conclusion. PMID:25019155

  2. TC-1 overexpression promotes cell proliferation in human non-small cell lung cancer that can be inhibited by PD173074.

    PubMed

    Lei, Jie; Li, Wenhai; Yang, Ye; Lu, Qiang; Zhang, Na; Bai, Guangzhen; Zhong, Daixing; Su, Kai; Liu, Boya; Li, Xiaofei; Wang, Yunjie; Wang, Xiaoping

    2014-01-01

    Thyroid cancer-1 (TC-1), a natively disordered protein, is widely expressed in vertebrates and overexpressed in many kinds of tumors. However, its exact role and regulation mechanism in human non-small cell lung cancer (NSCLC) are still unclear. In the present study, we found that TC-1 is highly expressed in NSCLC and that its aberrant expression is strongly associated with NSCLC cell proliferation. Exogenous TC-1 overexpression promotes cell proliferation, accelerates the cell G1-to-S-phase transition, and reduces apoptosis in NSCLC. The knockdown of TC-1, however, inhibits NSCLC cell proliferation, cycle transition, and apoptosis resistance. Furthermore, we also demonstrated that PD173074, which functions as an inhibitor of the TC-1 in NSCLC, decreases the expression of TC-1 and inhibits TC-1 overexpression mediated cell proliferation in vitro and in vivo. Nevertheless, the inhibition function of PD173074 on NSCLC cell proliferation was eliminated in cells with TC-1 knockdown. These results suggest that PD173074 plays a significant role in TC-1 overexpression mediated NSCLC cell proliferation and may be a potential intervention target for the prevention of cell proliferation in NSCLC. PMID:24941347

  3. TC-1 Overexpression Promotes Cell Proliferation in Human Non-Small Cell Lung Cancer that Can Be Inhibited by PD173074

    PubMed Central

    Zhang, Na; Bai, Guangzhen; Zhong, Daixing; Su, Kai; Liu, Boya; Li, Xiaofei; Wang, Yunjie; Wang, Xiaoping

    2014-01-01

    Thyroid cancer-1 (TC-1), a natively disordered protein, is widely expressed in vertebrates and overexpressed in many kinds of tumors. However, its exact role and regulation mechanism in human non-small cell lung cancer (NSCLC) are still unclear. In the present study, we found that TC-1 is highly expressed in NSCLC and that its aberrant expression is strongly associated with NSCLC cell proliferation. Exogenous TC-1 overexpression promotes cell proliferation, accelerates the cell G1-to-S-phase transition, and reduces apoptosis in NSCLC. The knockdown of TC-1, however, inhibits NSCLC cell proliferation, cycle transition, and apoptosis resistance. Furthermore, we also demonstrated that PD173074, which functions as an inhibitor of the TC-1 in NSCLC, decreases the expression of TC-1 and inhibits TC-1 overexpression mediated cell proliferation in vitro and in vivo. Nevertheless, the inhibition function of PD173074 on NSCLC cell proliferation was eliminated in cells with TC-1 knockdown. These results suggest that PD173074 plays a significant role in TC-1 overexpression mediated NSCLC cell proliferation and may be a potential intervention target for the prevention of cell proliferation in NSCLC. PMID:24941347

  4. Identification of the {gamma} transitions in Tc and Cs products of {sup 252}Cf fission and possible 7/2{sup +}[413] bands in {sup 105{minus}109}Tc isotopes

    SciTech Connect

    Hwang, J.K.; Ramayya, A.V.; Hamilton, J.H.; Peker, L.K.; Kormicki, J.; Babu, B.R.; Ginter, T.N.; Beyer, C.J.; Ter-Akopian, G.M.; Daniel, A.V.; Rasmussen, J.O.; Gilat, J.; Asztalos, S.J.; Chu, S.Y.; Gregorich, K.E.; Macchiavelli, A.O.; Macleod, R.W.; Ter-Akopian, G.M.; Oganessian, Y.T.; Daniel, A.V.; Ter-Akopian, G.M.; Daniel, A.V.; Ma, W.C.; Varmette, P.G.; Cole, J.D.; Aryaeinejad, R.; Butler-Moore, K.; Drigert, M.W.; Stoyer, M.A.; Bernstein, L.A.; Lougheed, R.W.; Moody, K.J.; Prussin, S.G.; Griffin, H.C.; Donangelo, R.

    1998-05-01

    Several {gamma} transitions in {sup 105{minus}109}Tc nuclei were identified for the first time from spontaneous fission studies with a {sup 252}Cf source and the Gammasphere. New level schemes are proposed and related to the underlying nuclear structure. Positive parity bands with a large signature splitting observed in {sup 105,107,109}Tc are evidently derived from g{sub 9/2} orbitals and are similar to analogous bands in {sup 103}Rh,{sup 103}Ag, and {sup 99}Y. New {gamma} transitions have also been identified in {sup 139{minus}143}Cs and used to construct level schemes for these isotopes. Correlated-pair fission yields extracted from the data show an appreciable field for the zero neutron {sup 109}Tc/{sup 143}Cs pair. {copyright} {ital 1998} {ital The American Physical Society}

  5. Investigation of radioactivity concentration in spent technetium generators

    NASA Astrophysics Data System (ADS)

    Idriss, Hajo; Salih, Isam; Alaamer, Abdulaziz S.; Eisa, M. H.; Sam, A. K.

    2014-04-01

    This study was carried out to survey and measure radioactivity concentration and estimate radiation dose level at the surface of spent technetium generator columns for the safe final disposal of radioactive waste. High resolution ?-spectrometry with the aid of handheld radiation survey meters has been used. The radioactivity measurements has shown that 238U, 40K and 137Cs were only measurable in one sample whereas 125Sb was found in 14 samples out of total of 20 samples with an activity concentration which ranged from 21 to 7404 with an average value of 1095 Bq/kg. The activity concentration of 125Sb is highly variable indicating that the spent 99mTc generator columns are of different origin. This investigation highlighted the importance of radiation monitoring of spent technetium generators in the country in order to protect workers, and the public from the dangers posed by radioactive waste.

  6. Survey of microwave surface impedance data of high-Tc superconductors - Evidence for nonpairing charge carriers

    NASA Astrophysics Data System (ADS)

    Mueller, G.; Klein, N.; Brust, A.; Chaloupka, H.; Hein, M.

    1990-09-01

    The microwave surface impedance of the high-Tc oxide superconductors has been measured at many laboratories around the world. A survey of their data between 100 MHz and 150 GHz for polycrystalline as well as single crystalline samples is given, focusing on YBa2Cu3O(7-delta). In comparison to the classical superconductors, these results reveal a very similar temperature dependence of the surface impedance close to Tc but an anomalous high residual surface resistance at lower temperatures. Both features can be explained by the assumption that oxide superconductors contain a significant number of nonpairing charge carriers. Within the framework of a properly extended two-fluid model, this is shown by analysis of best thin-film data. Moreover, the enhanced losses in polycrystalline material, especially for superposed magnetostatic field, result, to a large extent, from the deeper penetration depth. The possible origin of the nonpairing charge carriers and their impact on the applicability of the oxide superconductors is briefly discussed.

  7. Demonstration of 99mTc-labelled plasmin on the surface of ex vivo thrombi

    SciTech Connect

    Tengborn, L.; Hedner, U.; Rohlin, M.; Stahlberg, F.

    1982-12-15

    In an vitro system using the Chandler model for the preparation of in vitro thrombi trace amounts of porcine or human 99mTc-labelled plasmin was found to adsorb to the surface of a preformed thrombus. A radioactive lining of the thrombus could be demonstrated using autoradiography after addition of 99mTc-labelled plasmin in concentrations of 0.04 - 0.07 or 0.4 - 0.7 CTA u/thrombus made from 2 ml whole blood (0.035 - 0.35 microM). The same pattern was found for porcine as for human plasmin. The presence of tranexamic acid in concentrations of 3 to 12 mM did not affect the binding of plasmin indicating that the plasmin binding to fibrin was independent of the lysine binding sites. Furthermore alpha 2-antiplasmin was demonstrated on/in the thrombus also when no plasmin was present indicating a binding of alpha 2-antiplasmin to the thrombus. The plasmin bound to the thrombus was proteolytically inactive. In order to obtain thrombolysis most of the alpha 2-antiplasmin in the surrounding medium had to be neutralized.

  8. Metallic contaminant detection system using multi-channel high Tc SQUIDs

    NASA Astrophysics Data System (ADS)

    Tanaka, Saburo; Kitamura, Yoshihiro; Hatsukade, Yoshimi; Ohtani, Takeyoshi; Suzuki, Shuichi

    2012-10-01

    We have developed the magnetic metallic contaminant detectors using multiple high Tc SQUID gradiometers for industrial products. Finding ultra-small metallic contaminants is a big issue for manufacturers producing commercial products. The quality of industrial products such as lithium ion batteries can deteriorate by the inclusion of tiny metallic contaminants. When the contamination does occur, the manufacturer of the product suffers a great loss to recall the tainted products. Metallic particles with outer dimension less than 50 ?m cannot be detected by a conventional X-ray imaging. Therefore a high sensitive detection system for small foreign matters is required. However, in most of the cases, the matrix of an active material coated sheet electrode is magnetized and the magnetic signal from the matrix is large enough to mask the signal from contaminants. Thus we have developed a detection system based on a SQUID gradiometer and a horizontal magnetization to date. For practical use, we should increase the detection width of the system by employing multiple sensors. We successfully realized an eight-channel high-Tc SQUID gradiometer system for inspection of sheet electrodes of a lithium ion battery with width of at least 60 to 70 mm. Eight planar SQUID gradiometers were mounted with a separation of 9.0 mm. As a result, small iron particles of less than 50 ?m were successfully measured. This result suggests that the system is a promising tool for the detection of contaminants in a lithium ion battery.

  9. Effect of technetium Tc 99m pertechnetate on bacterial survival in solution

    SciTech Connect

    Stathis, V.J.; Miller, C.M.; Doerr, G.F.; Coffey, J.L.; Hladik, W.B.

    1983-04-01

    Survival of Staphylococcus epidermidis (10(2) organisms/ml) in solutions containing various levels of radioactivity was assessed. Six test preparations contained nonbacteriostatic 0.9% sodium chloride solution; four of these contained technetium Tc 99m pertechnetate (99mTcO-4) in various quantities (80, 250, 500, and 750 mCi). A fifth contained technetium that had decayed to an essentially nonradioactive form, and a sixth contained 0.9% sodium chloride solution only. Each of the six 20-ml solutions was inoculated with 2 ml of single-strength trypticase soy broth (TSB) containing 10(3) organisms/ml. At various times up to 12 hours after inoculation, 1-ml aliquots of each test solution were withdrawn and passed through 0.22-micron filters, thereby preventing further irradiation of the filtered organisms. The filters were incubated in single-strength TSB at 37 degrees C, and samples were examined for turbidity at 24, 48, and 72 hours. After 24 hours, 25 of the 36 sample tubes showed turbidity; after 48 hours, the turbid samples totaled 28. Bacteria in the two nonradioactive solutions remained viable throughout the 12-hour sampling period. Accumulated doses of radiation obtained in the 250-, 500-, and 750-mCi samples inhibited bacterial growth. To be a valid quality-control measure, sterility monitoring of prepared radiopharmaceutical dosage forms may need to be performed concurrently with their preparation.

  10. Removal of Sb-125 and Tc-99 from Liquid Radwaste by Novel Adsorbents

    SciTech Connect

    Harjula, R.O.; Koivula, R.; Paajanen, A.

    2006-07-01

    Novel proprietary metal oxide materials (MOM) have been tested for the removal of Sb-125 from simulated Floor Drain Waters of BWR. Antimony was present in the solutions as oxidized anionic form. Long term column experiment with simulated liquid that showed high Sb-125 removal at least up to 8000 bed volumes. One column experiments was carried out using nonradioactive Sb to exhaust the column. Leaching tests with 1000 ppm boric acid showed that 100 % of absorbed Sb remains in the sorbent material. Column experiments with real Fuel Pond Water from Olkiluoto NPP (BWR) showed reduction of Sb-125 (feed level 400 Bq/L, 1.10{sup -5} {mu}Ci/mL) below detection limit (MDA = 1.7 Bq/L, 5.10{sup -8},{mu}Ci/mL). Additional experiments have also been carried out with pertechnetate (Tc-99) ions. Results indicate that MOM materials are efficient also for the removal of Tc-99 from concentrated NaNO{sub 3} solution. (authors)

  11. Normal fasting and postprandial diisopropyl-IDA Tc 99m hepatobiliary stud

    SciTech Connect

    Klingensmith, W.C.; Spitzer, W.M.; Fritzberg, A.R.; Kuni, C.C.

    1981-12-01

    Diisopropyl-IDA TC 99m imaging studies were performed in 11 normal subjects in both the fasting and postprandial states. In 5- to 60-minute analog images obtained in both fasting and postprandial studies, the cardiac blood pool was almost never seen, renal pelvic radioactivity was commonly seen, the extrahepatic biliary tract was always seen, and the left hepatic duct was always more prominent than the right hepatic duct. The billiary tract was visualized by ten minutes in nine of 11 fasting studies and 10 of 11 postprandial studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandial studies (p<0.05). The zero- to sixty-minute digital data indicated a greater hepatocyte clearance, an earlier time of peak parenchymal radioactivity, and a faster parenchymal washout in the postprandial studies compared with fasting studies (p<0.05). Approximately nine percent of the injected dose was recovered in the urine during the first three hours in fasting and postprandial studies. The normal diisopropyl-IDA Tc 99m study in the fasting and postprandial states is defined; significant differences exist between the two states.

  12. The normal fasting and postprandial diisopropyl-IDA Tc 99m hepatobiliary study

    SciTech Connect

    Klingensmith, W.C.; Spitzer, V.M.; Fritzberg, A.R.; Kuni, C.C.

    1981-12-01

    Diisopropyl-IDA Tc 99m imaging studies were performed in 11 normal subjects in both the fasting and postprandial states. In 5- to 60-minute analog images obtained in both fasting and postprandial studies, the cardiac blood pool was almost never seen, renal pelvic radioactivity was commonly seen, the extrahepatic biliary tract was always seen, and the left hepatic duct was always more prominent than the right hepatic duct. The biliary tract was visualized by ten minutes in nine of 11 fasting studies and 10 of 11 postprandial studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandial studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandial studies (p less than 0.05). The zero- to sixty-minute digital data indicated a greater hepatocyte clearance, an earlier time of peak parenchymal radioactivity, and a faster parenchymal washout in the postprandial studies compared with fasting studies (p less than 0.05). Approximately nine percent of the injected dose was recovered in the urine during the first three hours in fasting and postprandial studies. The normal diisopropyl-IDA Tc 99m study in the fasting and postprandial states is defined; significant differences exist between the two states.

  13. Theory of the magnetic resonance for the high-TC cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Azzouz, M.

    2015-01-01

    The magnetic response expected from a state characterized by rotating antiferromagnetism in a neutron-scattering experiment is calculated. We predict the occurrence of a peak at the frequency of the rotation of the rotating antiferromagnetic order parameter. The doping dependence trends of this frequency are very similar to those of the frequency of the magnetic resonance observed in neutron-scattering experiments for the hole-doped high-TC cuprates. This leads us to propose the rotating antiferromagnetism as a possible mechanism for this magnetic resonance. Also, the interpretation of the rotating order parameter as a probability for a spin flip process to occur allows us to argue that the unusual zero momentum antiferromagnetic order observed by Fauqué et al. is equivalent to the rotating antiferromagnetism phenomenon. We conclude that while the magnitude of the rotating antiferromagnetic order parameter was previously proposed to be responsible for the pseudogap and the unusual thermodynamic and transport properties, the phase of the rotating order parameter is proposed here to be responsible for the unusual magnetic properties of the high-TC cuprate superconductors.

  14. Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor.

    PubMed

    Campi, G; Bianconi, A; Poccia, N; Bianconi, G; Barba, L; Arrighetti, G; Innocenti, D; Karpinski, J; Zhigadlo, N D; Kazakov, S M; Burghammer, M; Zimmermann, M v; Sprung, M; Ricci, A

    2015-09-17

    It has recently been established that the high-transition-temperature (high-Tc) superconducting state coexists with short-range charge-density-wave order and quenched disorder arising from dopants and strain. This complex, multiscale phase separation invites the development of theories of high-temperature superconductivity that include complexity. The nature of the spatial interplay between charge and dopant order that provides a basis for nanoscale phase separation remains a key open question, because experiments have yet to probe the unknown spatial distribution at both the nanoscale and mesoscale (between atomic and macroscopic scale). Here we report micro X-ray diffraction imaging of the spatial distribution of both short-range charge-density-wave 'puddles' (domains with only a few wavelengths) and quenched disorder in HgBa2CuO4 + y, the single-layer cuprate with the highest Tc, 95 kelvin (refs 26-28). We found that the charge-density-wave puddles, like the steam bubbles in boiling water, have a fat-tailed size distribution that is typical of self-organization near a critical point. However, the quenched disorder, which arises from oxygen interstitials, has a distribution that is contrary to the usually assumed random, uncorrelated distribution. The interstitial-oxygen-rich domains are spatially anticorrelated with the charge-density-wave domains, because higher doping does not favour the stripy charge-density-wave puddles, leading to a complex emergent geometry of the spatial landscape for superconductivity. PMID:26381983

  15. Quark Confinement in C-periodic Cylinders at Temperatures above T_c

    E-print Network

    K. Holland; U. -J. Wiese

    1997-02-13

    Due to the Gauss law, a single quark cannot exist in a periodic volume, while it can exist with C-periodic boundary conditions. In a C-periodic cylinder of cross section A = L_x L_y and length L_z >> L_x, L_y containing deconfined gluons, regions of different high temperature Z(3) phases are aligned along the z-direction, separated by deconfined- deconfined interfaces. In this geometry, the free energy of a single static quark diverges in proportion to L_z. Hence, paradoxically, the quark is confined, although the temperature T is larger than T_c. At T around T_c, the confined phase coexists with the three deconfined phases. The deconfined-deconfined interfaces can be completely or incompletely wet by the confined phase. The free energy of a quark behaves differently in these two cases. In contrast to claims in the literature, our results imply that deconfined-deconfined interfaces are not Euclidean artifacts, but have observable consequences in a system of hot gluons.

  16. Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor

    NASA Astrophysics Data System (ADS)

    Campi, G.; Bianconi, A.; Poccia, N.; Bianconi, G.; Barba, L.; Arrighetti, G.; Innocenti, D.; Karpinski, J.; Zhigadlo, N. D.; Kazakov, S. M.; Burghammer, M.; Zimmermann, M. V.; Sprung, M.; Ricci, A.

    2015-09-01

    It has recently been established that the high-transition-temperature (high-Tc) superconducting state coexists with short-range charge-density-wave order and quenched disorder arising from dopants and strain. This complex, multiscale phase separation invites the development of theories of high-temperature superconductivity that include complexity. The nature of the spatial interplay between charge and dopant order that provides a basis for nanoscale phase separation remains a key open question, because experiments have yet to probe the unknown spatial distribution at both the nanoscale and mesoscale (between atomic and macroscopic scale). Here we report micro X-ray diffraction imaging of the spatial distribution of both short-range charge-density-wave `puddles' (domains with only a few wavelengths) and quenched disorder in HgBa2CuO4 + y, the single-layer cuprate with the highest Tc, 95 kelvin (refs 26, 27, 28). We found that the charge-density-wave puddles, like the steam bubbles in boiling water, have a fat-tailed size distribution that is typical of self-organization near a critical point. However, the quenched disorder, which arises from oxygen interstitials, has a distribution that is contrary to the usually assumed random, uncorrelated distribution. The interstitial-oxygen-rich domains are spatially anticorrelated with the charge-density-wave domains, because higher doping does not favour the stripy charge-density-wave puddles, leading to a complex emergent geometry of the spatial landscape for superconductivity.

  17. ( sup 99m Tc)diphosphonate uptake and hemodynamics in arthritis of the immature dog knee

    SciTech Connect

    Hansen, E.S.; Soballe, K.; Henriksen, T.B.; Hjortdal, V.E.; Buenger, C. )

    1991-03-01

    The relationship between (99mTc)diphosphonate uptake and bone hemodynamics was studied in canine carrageenan-induced juvenile chronic arthritis. Blood flow was determined with microspheres, plasma and red cell volumes were measured by labeled fibrinogen and red cells, and the microvascular volume and mean transit time of blood were calculated. Normal femoral epiphyses had lower central and higher subchondral blood flow and diphosphonate uptake values. Epiphyseal vascular volume was uniform, resulting in a greater transit time of blood centrally. In arthritis, blood flow and diphosphonate uptake were increased subchondrally and unaffected centrally, while epiphyseal vascular volume was increased throughout, leading to prolonged transit time centrally. The normal metaphyses had low blood flow and diphosphonate uptake values in cancellous bone and very high values in growth plates, but a large vascular volume throughout. The mean transit time therefore was low in growth plates and high in adjacent cancellous bone. Arthritis caused decreased blood flow and diphosphonate uptake in growth plates but increased vascular volume and transit time of blood. Diphosphonate uptake correlated positively with blood flow and plasma volume and negatively with red cell volume in a nonlinear fashion. Thus, changes in diphosphonate uptake and microvascular hemodynamics occur in both epiphyseal and metaphyseal bone in chronic synovitis of the immature knee. The (99mTc)diphosphonate bone scan seems to reflect blood flow, plasma volume, and red cell volume of bone.

  18. Flight results of a new GEO infrared Earth sensor STD 15 on board TC2

    NASA Astrophysics Data System (ADS)

    Brunel, O.; Krebs, J. P.

    In the frame of the Telecom 2 and Hispasat spacecraft programs, Matra-Marconi Space (France) entrusted SODERN in 1988 for the development of an accurate version of the Earth sensor designed to operate on three axis stabilized satellites at geosynchronous altitude. This new sensor, called STD 15, is a versatile one directly derived from the STD 12 already used on board the SPOT/ERS satellites. Two STD 15 were launched for the first time in December 1991 on board the TC2-A satellite, followed by a second launch in April 1992 on board TC2-B and a third one in September 1992 on board HISPASAT 1A. After a few months of successful operation, the telemetry data have been analyzed by SODERN in order to draw conclusions about the STD 15 behavior. The aim of this paper is to descrbe the latest version of the sensor, then to carry out a preliminary analysis of the available in-flight data. After a short presentation of its operating principle and associated algorithms, the equipment is briefly described and its main features are shown with special attention to the error budget for the various operating modes: transfer orbit (classical or super-synchronous), Earth acquisition, antenna mapping attitude control and station keeping in GEO. Then the main performance results of on ground testing and computed theoretical results are discussed and compared with the in-flight results.

  19. 99mTc red blood cell scintigraphy in evaluating focal liver lesions

    SciTech Connect

    Rabinowitz, S.A.; McKusick, K.A.; Strauss, H.W.

    1984-07-01

    To determine the accuracy of blood-pool imaging in the diagnosis of hepatic hemangiomas, 39 patients with various focal hepatic lesions were studied. The diagnoses in these patients were made by biopsy, angiography, surgical exploration, or clinical stability for a minimum of 14 months. The diagnoses were: hemangiomas (13 patients), hepatoma (three), metastases (19), abscesses (two), and liver cysts (two). After modified in vivo labeling of red blood cells with 20 mCi (740 MBq) of 99mTc pertechnetate, an initial flow study and early (1-15 min) and delayed (1-2 hr) static images were obtained. Increased blood-pool activity with a discordant flow pattern was seen in 11 of 13 patients with hemangiomas. False-negative scans occurred in two hemangiomas with extensive fibrosis. Two of three hepatomas had increased blood-pool activity associated with increased flow in a pattern identical to the increased blood-pool activity. None of the metastatic, abscess, or cystic lesions had increased blood-pool activity at any time after injection. It is concluded that 99mTc red blood cell imaging can distinguish hemangiomas from other focal liver lesions.

  20. /sup 99m/Tc red blood cell scintigraphy in evaluating focal liver lesions

    SciTech Connect

    Rabinowitz, S.A.; McKusick, K.A.; Strauss, H.W.

    1984-07-01

    To determine the accuracy of blood-pool imaging in the diagnosis of hepatic hemangiomas, 39 patients with various focal hepatic lesions were studied. The diagnoses in these patients were made by biopsy, angiography, surgical exploration, or clinical stability for a minimum of 14 months. The diagnoses were: hemangiomas (13 patients), hepatoma (three), metastases (19), abscesses (two), and liver cysts (two). After modified in vivo labeling of red blood cells with 20 mCi (740 MBq) of /sup 99m/Tc pertechnetate, an initial flow study and early (1-15 min) and delayed (1-2 hr) static images were obtained. Increased blood-pool activity with a discordant flow pattern was seen in 11 of 13 patients with hemangiomas. False-negative scans occurred in two hemangiomas with extensive fibrosis. None of the metastatic, abscess, or cystic lesions had increased blood-pool activity at any time after injection. It is concluded that /sup 99m/Tc red blood cell imaging can distinguish hemangiomas from other focal liver lesions.